Science.gov

Sample records for power quality disturbance

  1. Automated recognition system for power quality disturbances

    NASA Astrophysics Data System (ADS)

    Abdelgalil, Tarek

    The application of deregulation policies in electric power systems has resulted in the necessity to quantify the quality of electric power. This fact highlights the need for a new monitoring strategy which is capable of tracking, detecting, classifying power quality disturbances, and then identifying the source of the disturbance. The objective of this work is to design an efficient and reliable power quality monitoring strategy that uses the advances in signal processing and pattern recognition to overcome the deficiencies that exist in power quality monitoring devices. The purposed monitoring strategy has two stages. The first stage is to detect, track, and classify any power quality violation by the use of on-line measurements. In the second stage, the source of the classified power quality disturbance must be identified. In the first stage, an adaptive linear combiner is used to detect power quality disturbances. Then, the Teager Energy Operator and Hilbert Transform are utilized for power quality event tracking. After the Fourier, Wavelet, and Walsh Transforms are employed for the feature extraction, two approaches are then exploited to classify the different power quality disturbances. The first approach depends on comparing the disturbance to be classified with a stored set of signatures for different power quality disturbances. The comparison is developed by using Hidden Markov Models and Dynamic Time Warping. The second approach depends on employing an inductive inference to generate the classification rules directly from the data. In the second stage of the new monitoring strategy, only the problem of identifying the location of the switched capacitor which initiates the transients is investigated. The Total Least Square-Estimation of Signal Parameters via Rotational Invariance Technique is adopted to estimate the amplitudes and frequencies of the various modes contained in the voltage signal measured at the facility entrance. After extracting the

  2. Assessment of Power Quality based on Fuzzy Logic and Discrete Wavelet Transform for Nonstationary Disturbances

    NASA Astrophysics Data System (ADS)

    Sinha, Pampa; Nath, Sudipta

    2010-10-01

    The main aspects of power system delivery are reliability and quality. If all the customers of a power system get uninterrupted power through the year then the system is considered to be reliable. The term power quality may be referred to as maintaining near sinusoidal voltage at rated frequency at the consumers end. The power component definitions are defined according to the IEEE Standard 1459-2000 both for single phase and three phase unbalanced systems based on Fourier Transform (FFT). In the presence of nonstationary power quality (PQ) disturbances results in accurate values due to its sensitivity to the spectral leakage problem. To overcome these limitations the power quality components are calculated using Discrete Wavelet Transform (DWT). In order to handle the uncertainties associated with electric power systems operations fuzzy logic has been incorporated in this paper. A new power quality index has been introduced here which can assess the power quality under nonstationary disturbances.

  3. Design of Interline Unified Power Quality Conditioner for Power Quality Disturbances using Simulink

    NASA Astrophysics Data System (ADS)

    Kumaraswamy, G.; Reddy, Y. Rajasekhar; Harikrishna, Ch.

    2012-10-01

    Proliferation of electronic equipment in commercial and industrial processes has resulted in increasingly sensitive electrical loads to be fed from power distribution system which introduce contamination to voltage and current waveforms at the point of common coupling of industrial loads. The unified power quality conditioner (UPQC) is connected between two different feeders (lines), hence this method of connection of the UPQC is called as Interline UPQC (IUPQC).This paper proposes a new connection for a UPQC to improve the power quality of two feeders in a distribution system. Interline Unified Power Quality Conditioner (IUPQC), specifically aims at the integration of series VSC and Shunt VSC to provide high quality power supply by means of voltage sag/swell compensation, harmonic elimination and power factor correction in a power distribution network, so that improved power quality can be made available at the point of common coupling. The structure, control and capability of the IUPQC are discussed in this paper. The efficiency of the proposed configuration has been verified through simulation using MATLAB/ SIMULINK.

  4. Power quality disturbance classification based on wavelet transform and self-organizing learning neural network

    NASA Astrophysics Data System (ADS)

    Ding, Guangbin; Liu, Lin

    2006-11-01

    A novel approach for the power quality (PQ) disturbances classification based on the wavelet transform (WT) and selforganizing learning array (SOLAR) system is proposed. Wavelet transform is utilized to extract feature vectors for various PQ disturbances and the WT can accurately localizes the characteristics of a signal both in the time and frequency domains. These feature vectors then are applied to a SOLAR system for training and disturbance pattern classification. By comparing with a classic neural network, it is concluded that SOLAR has better data driven learning and local interconnections performance. The research results between the proposed method and the other existing method is discussed and the proposed method can provide accurate classification results. On the basis of hypothesis test of the averages, it is shown that corresponding to different wavelets selection, there is no statistically significant difference in performance of PQ disturbances classification and the relationship between the wavelet decomposition level and classification performance is discussed. The simulation results demonstrate the proposed method gives a new way for identification and classification of dynamic power quality disturbances.

  5. A Hilbert Transform-Based Smart Sensor for Detection, Classification, and Quantification of Power Quality Disturbances

    PubMed Central

    Granados-Lieberman, David; Valtierra-Rodriguez, Martin; Morales-Hernandez, Luis A.; Romero-Troncoso, Rene J.; Osornio-Rios, Roque A.

    2013-01-01

    Power quality disturbance (PQD) monitoring has become an important issue due to the growing number of disturbing loads connected to the power line and to the susceptibility of certain loads to their presence. In any real power system, there are multiple sources of several disturbances which can have different magnitudes and appear at different times. In order to avoid equipment damage and estimate the damage severity, they have to be detected, classified, and quantified. In this work, a smart sensor for detection, classification, and quantification of PQD is proposed. First, the Hilbert transform (HT) is used as detection technique; then, the classification of the envelope of a PQD obtained through HT is carried out by a feed forward neural network (FFNN). Finally, the root mean square voltage (Vrms), peak voltage (Vpeak), crest factor (CF), and total harmonic distortion (THD) indices calculated through HT and Parseval's theorem as well as an instantaneous exponential time constant quantify the PQD according to the disturbance presented. The aforementioned methodology is processed online using digital hardware signal processing based on field programmable gate array (FPGA). Besides, the proposed smart sensor performance is validated and tested through synthetic signals and under real operating conditions, respectively. PMID:23698264

  6. A Hilbert transform-based smart sensor for detection, classification, and quantification of power quality disturbances.

    PubMed

    Granados-Lieberman, David; Valtierra-Rodriguez, Martin; Morales-Hernandez, Luis A; Romero-Troncoso, Rene J; Osornio-Rios, Roque A

    2013-04-25

    Power quality disturbance (PQD) monitoring has become an important issue due to the growing number of disturbing loads connected to the power line and to the susceptibility of certain loads to their presence. In any real power system, there are multiple sources of several disturbances which can have different magnitudes and appear at different times. In order to avoid equipment damage and estimate the damage severity, they have to be detected, classified, and quantified. In this work, a smart sensor for detection, classification, and quantification of PQD is proposed. First, the Hilbert transform (HT) is used as detection technique; then, the classification of the envelope of a PQD obtained through HT is carried out by a feed forward neural network (FFNN). Finally, the root mean square voltage (Vrms), peak voltage (Vpeak), crest factor (CF), and total harmonic distortion (THD) indices calculated through HT and Parseval's theorem as well as an instantaneous exponential time constant quantify the PQD according to the disturbance presented. The aforementioned methodology is processed online using digital hardware signal processing based on field programmable gate array (FPGA). Besides, the proposed smart sensor performance is validated and tested through synthetic signals and under real operating conditions, respectively.

  7. Optical remote sensing and correlation of office equipment functional state and stress levels via power quality disturbances inefficiencies

    NASA Astrophysics Data System (ADS)

    Sternberg, Oren; Bednarski, Valerie R.; Perez, Israel; Wheeland, Sara; Rockway, John D.

    2016-09-01

    Non-invasive optical techniques pertaining to the remote sensing of power quality disturbances (PQD) are part of an emerging technology field typically dominated by radio frequency (RF) and invasive-based techniques. Algorithms and methods to analyze and address PQD such as probabilistic neural networks and fully informed particle swarms have been explored in industry and academia. Such methods are tuned to work with RF equipment and electronics in existing power grids. As both commercial and defense assets are heavily power-dependent, understanding electrical transients and failure events using non-invasive detection techniques is crucial. In this paper we correlate power quality empirical models to the observed optical response. We also empirically demonstrate a first-order approach to map household, office and commercial equipment PQD to user functions and stress levels. We employ a physics-based image and signal processing approach, which demonstrates measured non-invasive (remote sensing) techniques to detect and map the base frequency associated with the power source to the various PQD on a calibrated source.

  8. Power Quality Aspects in a Wind Power Plant: Preprint

    SciTech Connect

    Muljadi, E.; Butterfield, C. P.; Chacon, J.; Romanowitz, H.

    2006-01-01

    Although many operational aspects affect wind power plant operation, this paper focuses on power quality. Because a wind power plant is connected to the grid, it is very important to understand the sources of disturbances that affect the power quality.

  9. Rural power quality

    SciTech Connect

    Koval, D.O. . Dept. of Electrical Engineering); Chang, J.C. ); Leonard, J. . Dept. of Agricultural Engineering)

    1992-07-01

    Very little published literature is available on the quality of power being delivered to rural industries. This paper will present the results of a detailed power quantity monitoring survey of 17 out of the 23 small rural industries surveyed (i.e., poultry broiler, poultry layer, beef feedlot, and pig (farrow to finish) rural industrial sites) and sponsored by the Canadian Electrical Association; the survey will provide a knowledge base on rural power quality and the possible origins of power supply anomalies. This paper will summarize the major power quality problems experienced at the various industrial sites and present some of the significant results of an across Canada questionnaire survey on On-farm Electrical Power Disturbances. The results of these surveys will provide a basis for mitigating actions by the utilities and their rural industrial customers by enhancing their ability to identify the possible origins of power supply disturbances affecting the performance of electronic and electrical equipment at the various farm industrial sites.

  10. Geomagnetic disturbance effects on power systems

    SciTech Connect

    Albertson, V.D.; Bozoki, B.; Feero, W.E.; Kappenman, J.G.; Larsen, E.V.; Nordell, D.E.; Ponder, J.; Prabhakara, F.S.; Thompson, K.; Walling, R.

    1993-07-01

    In the northern hemisphere, the aurora borealis is visual evidence of simultaneous fluctuations in the earth's magnetic field (geomagnetic field). These geomagnetic disturbances (GMD's), or geomagnetic storms, can affect a number of man-made systems, including electric power systems. The GMD's are caused by the electromagnetic interaction of the solar wind plasma of protons and electrons with the geomagnetic field. These dynamic impulses in the solar wind are due to solar flares, coronal holes, and disappearing filaments, and reach the earth from one to six days after being emitted by a solar event. Instances of geomagnetic storms affecting telegraph systems were noted in England in 1846, and power system disturbances linked to GMD's were first reported in the United States in 1940. This Working Group report is a summary of the state of knowledge and research activity to the present time, and covers the GMD/Geomagnetically-induced currents (GIC) phenomena, transformer effects, the impact on generators, protective relay effects, and communication system effects. It also summarizes modeling and predicting GIC, measuring and monitoring GIC, mitigation methods, system operating guidelines during GMD's, and alerting and forecasting procedures and needs for the power industry.

  11. Recent Power Quality Technology

    NASA Astrophysics Data System (ADS)

    Okumura, Mutsumu; Kobayashi, Naoki

    With prevalence of high-specified equipment such as power electronics applied device, power quality problems are becoming concerned for both electric utilities and customers. This paper firstly describes what power quality problem is, and then, it outlines recent power quality technologies classified into those of immunity or emission side from the viewpoint of EMC concept, which is practical approach to consider these problems.

  12. Power quality in clinical facilities.

    PubMed

    Moreno-Muñoz, Antonio; González, Juan J

    2006-04-01

    This paper presents preliminary results from a power quality audit conducted at a clinical building over the last year. Voltage and current were measured at various laboratories; it was found that the main problems for the equipment installed were voltage sags and surges. The paper examines the causes and effects of power disturbances that affect computer or any other microprocessor-based equipment and analyzes the auto-protection capabilities of modern power supplies. The convenience of "enhanced power supply" or "low-cost customer-side" protection solutions is also discussed. Finally it is addresses the role of the Standards on the protection of electronic equipment and the implications for the final costumer.

  13. Power Quality Aspects in a Wind Power Plant

    SciTech Connect

    Muljadi, E.; Butterfield, C. P.; Chacon, J.; Romanowitz, H.

    2006-01-01

    Like conventional power plants, wind power plants must provide the power quality required to ensure the stability and reliability of the power system it is connected to and to satisfy the customers connected to the same grid. When wind energy development began, wind power plants were very small, ranging in size from under one megawatt to tens megawatts with less than 100 turbines in each plant. Thus, the impact of wind power plant on the grid was very small, and any disturbance within or created by the plant was considered to be in the noise level. In the past 30 years, the size of wind turbines and the size of wind power plants have increased significantly. Notably, in Tehachapi, California, the amount of wind power generation has surpassed the infrastructure for which it was designed. At the same time, the lack of rules, standards, and regulations during early wind development has proven to be an increasing threat to the stability and power quality of the grid connected to a wind power plant. Fortunately, many new wind power plants are equipped with state of the art technology, which enables them to provide good service while producing clean power for the grid. The advances in power electronics have allowed many power system applications to become more flexible and to accomplish smoother regulation. Applications such as reactive power compensation, static transfer switches, energy storage, and variable-speed generations are commonly found in modern wind power plants. Although many operational aspects affect wind power plant operation, this paper, focuses on power quality. Because a wind power plant is connected to the grid, it is very important to understand the sources of disturbances that affect the power quality. In general, the voltage and frequency must be kept as stable as possible. The voltage and current distortions created by harmonics will also be discussed in this paper as will self-excitation, which may occur in a wind power plant due to loss of line.

  14. Effects of Forest Disturbance on Water Quality in Appalachian Watersheds

    NASA Astrophysics Data System (ADS)

    Eshleman, K. N.; Townsend, P.

    2006-12-01

    Land use/land cover changes and a variety of transient watershed disturbances are regarded as important factors that can significantly influence water quality in associated aquatic ecosystems. In forest ecosystems, nitrate-N losses to surface waters provide a sensitive integrative indicator of the biogeochemical status of the forest and of its response to disturbances. While effects of human-induced forest disturbances (e.g., forest harvesting) have been relatively well studied in carefully controlled field experiments, natural forest disturbances and their ecosystem-level impacts are far less well understood. The purpose of this research is to quantify the eco-hydrological effects of historical and current forest disturbances in three large predominantly forested areas of the eastern U.S.: Savage River watershed (Maryland), Fifteenmile Creek watershed (Maryland & Pennsylvania), and Shenandoah National Park (Virginia). Each of these study areas is predominantly forested, has been extensively disturbed within the last 15 years by one or more human- induced or natural disturbance agents (e.g., ice storms, blow-downs, insect defoliations, etc.), and covers an area of several hundred square kilometers. Our research integrates the study of disturbances at multiple scales using remote sensing analyses (landscape scale), observations of surface water quality (watershed scale), and measurements of ecosystem processes within forests (plot scale). In the paper we provide evidence of relationships between transient land cover alterations/disturbances and systematic measurements of surface water quality. In particular, we use our water monitoring data to test whether nitrate-N concentrations in soil water and streamwater vary as linear functions of the magnitude (intensity, frequency, and extensity) and timing of disturbance at three different spatial scales (plot, watershed, and landscape).

  15. Methodology to assess quality of estimated disturbances in active disturbance rejection control structure for mechanical system.

    PubMed

    Rosas, A David; Velazquez, V Karla; Olivares, F Luz; Camacho, T Adrian; Williams, Ivan

    2017-09-01

    A methodology to assess the quality of estimation of disturbances in mechanical systems, by state observers, in the control structure with active compensation of disturbances (ADRC) is presented. Evaluation is carried out by four performance indices that depend on the steady-state error between reference signals and output of the plant. These indices are related with the accuracy and precision of the closed loop system in the sense of norms L2 and L∞, for a set of reference signals representing the typical operating conditions of the mechanism. The effectiveness of the methodology is illustrated with the quality assessment of the estimated disturbance of five state observers to control of a simple pendulum and validated on a SCARA robot arm. Copyright © 2017 ISA. Published by Elsevier Ltd. All rights reserved.

  16. Power grid disturbances and polar cap index during geomagnetic storms

    NASA Astrophysics Data System (ADS)

    Stauning, Peter

    2013-06-01

    The strong geomagnetic storm in the evening of 30 October 2003 caused high-voltage power grid disturbances in Sweden that expanded to produce hour-long power line outage in Malmö located in the southern part of the country. This was not a unique situation. The geomagnetic storm on 13 March 1989 caused extensive disruptions of high-voltage power circuits especially in the Province of Quebec, Canada, but also to a lesser degree in Scandinavia. Similar events have occurred earlier, among others, during the great storms of 13-14 July 1982 and 8-9 February 1986. These high-voltage power grid disturbances were related to impulsive magnetic variations accompanying extraordinarily intense substorm events. The events were preceded by lengthy intervals of unusually high values of the Polar Cap (PC) index caused by enhanced transpolar ionospheric convection. The transpolar convection transports magnetic flux from the dayside to nightside which causes equatorward displacements of the region of auroral activity enabling the substorms to hit vital power grids. During the 30 October 2003 event the intense solar proton radiation disabled the ACE satellite observations widely used to provide forecast of magnetic storm events. Hence in this case the alarmingly high PC index could provide useful warning of the storm as a back-up of the missing ACE-based forecast. In further cases, monitoring the PC index level could provide supplementary storm warnings to the benefit of power grid operators.

  17. 77 FR 22312 - Geomagnetic Disturbances to the Bulk-Power System; Notice of Technical Conference

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-04-13

    ... Energy Regulatory Commission Geomagnetic Disturbances to the Bulk-Power System; Notice of Technical... Conference on Geomagnetic Disturbances to the Bulk-Power System on Monday, April 30, 2012, from 11 a.m. to 4... issues related to reliability of the Bulk-Power System as affected by geomagnetic disturbances. The...

  18. Power Disturbances Classification Using S-Transform Based GA-PNN

    NASA Astrophysics Data System (ADS)

    Manimala, K.; Selvi, K.

    2015-09-01

    The significance of detection and classification of power quality events that disturb the voltage and/or current waveforms in the electrical power distribution networks is well known. Consequently, in spite of a large number of research reports in this area, a research on the selection of proper parameter for specific classifiers was so far not explored. The parameter selection is very important for successful modelling of input-output relationship in a function approximation model. In this study, probabilistic neural network (PNN) has been used as a function approximation tool for power disturbance classification and genetic algorithm (GA) is utilised for optimisation of the smoothing parameter of the PNN. The important features extracted from raw power disturbance signal using S-Transform are given to the PNN for effective classification. The choice of smoothing parameter for PNN classifier will significantly impact the classification accuracy. Hence, GA based parameter optimization is done to ensure good classification accuracy by selecting suitable parameter of the PNN classifier. Testing results show that the proposed S-Transform based GA-PNN model has better classification ability than classifiers based on conventional grid search method for parameter selection. The noisy and practical signals are considered for the classification process to show the effectiveness of the proposed method in comparison with existing methods.

  19. [Quality of life in visual disturbances in multiple sclerosis].

    PubMed

    Opara, Józef; Szwejkowski, Waldemar; Brola, Waldemar

    2008-01-01

    In multiple sclerosis (MS) often the visual pathway is impaired. Very early symptom which precedes neurological signs is the retrobulbar optic neuritis. In MS patients near as well as distance, color and peripheral vision can be disturbed. Many patients are not aware of visual impairment which could cause the delay in diagnosis. The assessment of the visual field in patients with MS enables early diagnosing as well as monitoring of the course of the disease. In monitoring of the course of disease most important is the evaluation of quality of life. The assessment of quality of life in MS is well known, even better than in other neurological diseases. Less known is the question of quality of life diminished because of visual field defects in MS. In review report the value of perimetry in diagnosing MS, visual disturbances in MS and contemporary possibilities of evaluation of quality of life in MS patients including those with defects in visual field has been described. The VFQ-25 questionnaire is a sensitive and useful tool in self-assessing visual function in MS patients.

  20. Various power quality challenges and solution techniques using FACTS technology for power system

    NASA Astrophysics Data System (ADS)

    Soni, J. Sandeep; Jangalwa, N. K.; Gupta, R.; Palwalia, D. K.

    2016-03-01

    This paper presents a comprehensive review on the various power quality problems and various solution techniques using FACTS in Power system. The term "Power Quality" is a broad concept and its meaning is taken different by different peoples. It is associated with electrical transmission, distribution and utilization systems those are having experience of any Voltage, current or frequency divergence from normal operation. Due to power quality problems industries have to invest large amount for mitigation of Voltage sags, distortions, harmonics and short term interruptions/disturbances etc. In paper authors tried to cover various possible sources and compensation methods of reactive power in power system.

  1. Direct energy balance based active disturbance rejection control for coal-fired power plant.

    PubMed

    Sun, Li; Hua, Qingsong; Li, Donghai; Pan, Lei; Xue, Yali; Lee, Kwang Y

    2017-09-01

    The conventional direct energy balance (DEB) based PI control can fulfill the fundamental tracking requirements of the coal-fired power plant. However, it is challenging to deal with the cases when the coal quality variation is present. To this end, this paper introduces the active disturbance rejection control (ADRC) to the DEB structure, where the coal quality variation is deemed as a kind of unknown disturbance that can be estimated and mitigated promptly. Firstly, the nonlinearity of a recent power plant model is analyzed based on the gap metric, which provides guidance on how to set the pressure set-point in line with the power demand. Secondly, the approximate decoupling effect of the DEB structure is analyzed based on the relative gain analysis in frequency domain. Finally, the synthesis of the DEB based ADRC control system is carried out based on multi-objective optimization. The optimized ADRC results show that the integrated absolute error (IAE) indices of the tracking performances in both loops can be simultaneously improved, in comparison with the DEB based PI control and H∞ control system. The regulation performance in the presence of the coal quality variation is significantly improved under the ADRC control scheme. Moreover, the robustness of the proposed strategy is shown comparable with the H∞ control. Copyright © 2017. Published by Elsevier Ltd.

  2. Atmospheric disturbance modelling requirements for flying qualities applications

    NASA Technical Reports Server (NTRS)

    Moorhouse, D. J.

    1978-01-01

    Flying qualities are defined as those airplane characteristics which govern the ease or precision with which the pilot can accomplish the mission. Some atmospheric disturbance modelling requirements for aircraft flying qualities applications are reviewed. It is concluded that some simplifications are justified in identifying the primary influence on aircraft response and pilot control. It is recommended that a universal environmental model be developed, which could form the reference for different applications. This model should include the latest information on winds, turbulence, gusts, visibility, icing and precipitation. A chosen model would be kept by a national agency and updated regularly by feedback from users. A user manual is believed to be an essential part of such a model.

  3. 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.

  4. Power Quality Evaluation of 480-V, 2-MVA UPS Systems

    SciTech Connect

    CAMM,E.H.; COREY,GARTH P.; ROBERTS,B.

    2000-06-21

    A mobile 480-V, 2-MVA UPS System utilizing battery energy storage was installed at S and C Electric Company's Polymer Products Fabrication Building in Chicago, Illinois in May 1999 to provide uninterrupted power to the building for up to 15 seconds in the event of a voltage sag or momentary interruption in the local utility supply. Similar units can be applied at medium voltage through the application of a step-up transformer to provide momentary power disturbance ride through of up to 30 seconds for loads up to 15 MVA at system voltages ranging from 4.16 kV to 34.5 kV. A power quality evaluation of the installation was performed over a six-month period from July 1999 to early January 2000. This paper describes the details and results of this power quality evaluation, which involved two phases. Phase I involved the collection and review of power disturbance data and the effects on process equipment, while Phase II involved power quality monitoring of utility source and building load voltages and currents over a period of six months. Review of power disturbance data and equipment power-disturbance ride-through characteristics during Phase I of the project indicated that the polymer fabrication process in the building is affected by the tripping of motors driving hydraulic pumps for the thermal set molding machines. The tripping of these motors may have resulted in direct production losses in 1998 of approximately $468,000. The monitoring conducted during Phase II of the project showed that the PureWave UPS operated as intended during 12 utility voltage sag events to protect the building's load against momentary power disturbances. In addition, the unit operated successfully during many staged interruptions involving opening of a source-side circuit breaker.

  5. Damping and power spectra of quasi-periodic intensity disturbances above a solar polar coronal hole

    NASA Astrophysics Data System (ADS)

    Jiao, Fang-Ran; Xia, Li-Dong; Huang, Zheng-Hua; Li, Bo; Fu, Hui; Yuan, Ding; Chandrashekhar, Kalugodu

    2016-06-01

    We study intensity disturbances above a solar polar coronal hole that can be seen in the AIA 171 Å and 193 Å passbands, aiming to provide more insights into their physical nature. The damping and power spectra of the intensity disturbances with frequencies from 0.07 mHz to 10.5 mHz are investigated. The damping of the intensity disturbances tends to be stronger at lower frequencies, and their damping behavior below 980″ (for comparison, the limb is at 945″) is different from what happens above. No significant difference is found between the damping of the intensity disturbances in the AIA 171 Å and that in the AIA 193 Å. The indices of the power spectra of the intensity disturbances are found to be slightly smaller in the AIA 171 Å than in the AIA 193 Å, but the difference is within one standard deviation. An additional enhanced component is present in the power spectra in a period range of 8-40 min at lower heights. The power spectra of a spicule is highly correlated with its associated intensity disturbance, which suggests that the power spectra of the intensity disturbances might be a mixture of spicules and wave activities. We suggest that each intensity disturbance in the polar coronal hole is possibly a series of independent slow magnetoacoustic waves triggered by spicular activities.

  6. Machine Learning for Power System Disturbance and Cyber-attack Discrimination

    SciTech Connect

    Borges, Raymond Charles; Beaver, Justin M; Buckner, Mark A; Morris, Thomas; Adhikari, Uttam; Pan, Shengyi

    2014-01-01

    Power system disturbances are inherently complex and can be attributed to a wide range of sources, including both natural and man-made events. Currently, the power system operators are heavily relied on to make decisions regarding the causes of experienced disturbances and the appropriate course of action as a response. In the case of cyber-attacks against a power system, human judgment is less certain since there is an overt attempt to disguise the attack and deceive the operators as to the true state of the system. To enable the human decision maker, we explore the viability of machine learning as a means for discriminating types of power system disturbances, and focus specifically on detecting cyber-attacks where deception is a core tenet of the event. We evaluate various machine learning methods as disturbance discriminators and discuss the practical implications for deploying machine learning systems as an enhancement to existing power system architectures.

  7. Multiple Chaos Synchronization System for Power Quality Classification in a Power System

    PubMed Central

    Huang, Cong-Hui; Lin, Chia-Hung

    2014-01-01

    This document proposes multiple chaos synchronization (CS) systems for power quality (PQ) disturbances classification in a power system. Chen-Lee based CS systems use multiple detectors to track the dynamic errors between the normal signal and the disturbance signal, including power harmonics, voltage fluctuation phenomena, and voltage interruptions. Multiple detectors are used to monitor the dynamic errors between the master system and the slave system and are used to construct the feature patterns from time-domain signals. The maximum likelihood method (MLM), as a classifier, performs a comparison of the patterns of the features in the database. The proposed method can adapt itself without the need for adjustment of parameters or iterative computation. For a sample power system, the test results showed accurate discrimination, good robustness, and faster processing time for the detection of PQ disturbances. PMID:24764771

  8. 77 FR 24952 - Staff Technical Conference on Geomagnetic Disturbances to the Bulk-Power System; Technical...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-04-26

    .... to 4:00 p.m. to discuss issues related to the reliability of the Bulk-Power System as affected by... currents to transformers and other equipment on the Bulk-Power System, as well as, options for addressing... Energy Regulatory Commission Staff Technical Conference on Geomagnetic Disturbances to the Bulk-Power...

  9. Mindfulness Meditation and Improvement in Sleep Quality and Daytime Impairment Among Older Adults With Sleep Disturbances

    PubMed Central

    Black, David S.; O’Reilly, Gillian A.; Olmstead, Richard; Breen, Elizabeth C.; Irwin, Michael R.

    2015-01-01

    IMPORTANCE Sleep disturbances are most prevalent among older adults and often go untreated. Treatment options for sleep disturbances remain limited, and there is a need for community-accessible programs that can improve sleep. OBJECTIVE To determine the efficacy of a mind-body medicine intervention, called mindfulness meditation, to promote sleep quality in older adults with moderate sleep disturbances. DESIGN, SETTING, AND PARTICIPANTS Randomized clinical trial with 2 parallel groups conducted from January 1 to December 31, 2012, at a medical research center among an older adult sample (mean [SD] age, 66.3 [7.4] years) with moderate sleep disturbances (Pittsburgh Sleep Quality Index [PSQI] >5). INTERVENTIONS A standardized mindful awareness practices (MAPs) intervention (n = 24) or a sleep hygiene education (SHE) intervention (n = 25) was randomized to participants, who received a 6-week intervention (2 hours per week) with assigned homework. MAIN OUTCOMES AND MEASURES The study was powered to detect between-group differences in moderate sleep disturbance measured via the PSQI at postintervention. Secondary outcomes pertained to sleep-related daytime impairment and included validated measures of insomnia symptoms, depression, anxiety, stress, and fatigue, as well as inflammatory signaling via nuclear factor (NF)–κB. RESULTS Using an intent-to-treat analysis, participants in the MAPs group showed significant improvement relative to those in the SHE group on the PSQI. With the MAPs intervention, the mean (SD) PSQIs were 10.2 (1.7) at baseline and 7.4 (1.9) at postintervention. With the SHE intervention, the mean (SD) PSQIs were 10.2 (1.8) at baseline and 9.1 (2.0) at postintervention. The between-group mean difference was 1.8 (95%CI, 0.6–2.9), with an effect size of 0.89. The MAPs group showed significant improvement relative to the SHE group on secondary health outcomes of insomnia symptoms, depression symptoms, fatigue interference, and fatigue severity (P

  10. Recent Power Quality Technology Employing Power Electronics Devices

    NASA Astrophysics Data System (ADS)

    Takasaki, Masahiro

    Power quality has become a common concern of customers and utilities in improving respective profits in the context of an open electricity market. Power electronics is the essential technology to control power quality in accordance with customer requirements and utility standards. This paper first summarizes power quality definitions and indices used in IEEE and IEC standards. It clarifies the problem to be solved and the role of power electronics devices. Then the overview of power quality control methods and equipments employing power electronics devices is explained. The control methodology discussed in this paper includes various schemes of future distribution and power supply system now under development.

  11. Power Quality and Reliability Project

    NASA Technical Reports Server (NTRS)

    Attia, John O.

    2001-01-01

    One area where universities and industry can link is in the area of power systems reliability and quality - key concepts in the commercial, industrial and public sector engineering environments. Prairie View A&M University (PVAMU) has established a collaborative relationship with the University of'Texas at Arlington (UTA), NASA/Johnson Space Center (JSC), and EP&C Engineering and Technology Group (EP&C) a small disadvantage business that specializes in power quality and engineering services. The primary goal of this collaboration is to facilitate the development and implementation of a Strategic Integrated power/Systems Reliability and Curriculum Enhancement Program. The objectives of first phase of this work are: (a) to develop a course in power quality and reliability, (b) to use the campus of Prairie View A&M University as a laboratory for the study of systems reliability and quality issues, (c) to provide students with NASA/EPC shadowing and Internship experience. In this work, a course, titled "Reliability Analysis of Electrical Facilities" was developed and taught for two semesters. About thirty seven has benefited directly from this course. A laboratory accompanying the course was also developed. Four facilities at Prairie View A&M University were surveyed. Some tests that were performed are (i) earth-ground testing, (ii) voltage, amperage and harmonics of various panels in the buildings, (iii) checking the wire sizes to see if they were the right size for the load that they were carrying, (iv) vibration tests to test the status of the engines or chillers and water pumps, (v) infrared testing to the test arcing or misfiring of electrical or mechanical systems.

  12. Detection of and Compensation for EMG Disturbances for Powered Lower Limb Prosthesis Control.

    PubMed

    Spanias, John A; Perreault, Eric J; Hargrove, Levi J

    2016-02-01

    Myoelectric pattern recognition algorithms have been proposed for the control of powered lower limb prostheses, but electromyography (EMG) signal disturbances remain an obstacle to clinical implementation. To address this problem, we used a log-likelihood metric to detect simulated EMG disturbances and real disturbances acquired from EMG containing electrode shift. We found that features extracted from disturbed EMG have much lower log likelihoods than those from undisturbed signals and can be detected using a single threshold acquired from the training data. We designed a linear discriminant analysis (LDA) classifier that uses the log likelihood to decide between using a combination of EMG and mechanical sensors and using mechanical sensors only, to predict locomotion modes. When EMG contained disturbances, our classifier detected those disturbances and disregarded EMG data. Our classifier had significantly lower errors than a standard LDA classifier in the presence of EMG disturbances. The log-likelihood classifier had a low false positive threshold, and thus did not perform significantly differently from the standard LDA classifier when EMG did not contain disturbances. The log-likelihood threshold could also be applied to individual EMG channels, enabling specific channels containing EMG disturbances to be appropriately ignored when making locomotion mode predictions.

  13. 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

  14. Power quality load management for large spacecraft electrical power systems

    NASA Technical Reports Server (NTRS)

    Lollar, Louis F.

    1988-01-01

    In December, 1986, a Center Director's Discretionary Fund (CDDF) proposal was granted to study power system control techniques in large space electrical power systems. Presented are the accomplishments in the area of power system control by power quality load management. In addition, information concerning the distortion problems in a 20 kHz ac power system is presented.

  15. {open_quotes}Secure Bus{close_quotes} disturbance-free power at the utility substation level

    SciTech Connect

    Boenig, H.J.; Jones, W.H.

    1996-12-01

    Over the last 18 months Public Service Company of New Mexico (PNM), El Camino Real Engineering, Inc. (CRE), Los Alamos National Laboratory (LANL) and Sandia National Laboratories (SNL) have worked on the development of disturbance-free power at the medium voltage substation level. The work resulted in the Secure Bus concept, a system in which a medium voltage bus in a substation is immune to power outages and voltage sags on the utility source. The Secure Bus voltage is also immune to voltage sags resulting from faults on any distribution feeder connected to the bus. The Secure Bus concept originated from work conducted to improve power quality for large high-tech manufacturing facilities, in particular for large semiconductor manufacturing plants. For the demands on quality power of a modern facility conventional equipment is not adequate for protecting the end user. For example, the operation of conventional vacuum breakers during short circuit conditions on a feeder circuit, requiring 3 to 5 cycles for breaker opening, does not allow for fast enough current interruption to avoid a voltage dip on the main bus. A sever voltage sag could result in a shut down of sensitive equipment being supplied by the other feeder circuits, which are connected to the main bus. The circumvent the problem, a fast breaker was introduced which interrupts the short circuit before the current causes a significant voltage disturbance. To make the bus immune also to power disturbances caused by power outages, energy storage is introduced to provide the necessary energy back-up in case the primary source is not available.

  16. Relationship Between Mood Disturbance and Sleep Quality in Oncology Outpatients at the Initiation of Radiation Therapy

    PubMed Central

    Van Onselen, Christina; Dunn, Laura B.; Lee, Kathryn; Dodd, Marylin; Koetters, Theresa; West, Claudia; Paul, Steven M.; Aouizerat, Bradley E.; Wara, William; Swift, Patrick; Miaskowski, Christine

    2010-01-01

    Purpose of the research The purpose of this study was to describe the occurrence of significant mood disturbance and evaluate for differences in sleep quality among four mood groups (i.e., neither anxiety nor depression, only anxiety, only depression, anxiety and depression) prior to the initiation of radiation therapy (RT). Methods and sample Patients (n=179) with breast, prostate, lung, and brain cancer were evaluated prior to the initiation of RT using the Pittsburgh Sleep Quality Index (PSQI), the Center for Epidemiological Studies Depression Scale, and the Spielberger State Anxiety Inventory. Differences in sleep disturbance among the four mood groups were evaluated using analyses of variance. Key results While 38% of the patients reported some type of mood disturbance, 57% of the patients reported sleep disturbance. Patients with clinically significant levels of anxiety and depression reported the highest levels of sleep disturbance. Conclusions Overall, oncology patients with mood disturbances reported more sleep disturbance than those without mood disturbance. Findings suggest that oncology patients need to be assessed for mood and sleep disturbances. PMID:20080444

  17. Design of Power Quality Monitor Based on Embedded Industrial Computer

    NASA Astrophysics Data System (ADS)

    Junfeng, Huang; Hao, Sun; Xiaolin, Wei

    A design about electric power quality monitor device based on embedded industrial computer was proposed. On this basis, we introduced the framework and arithmetic of the device. Because of the existence of the harmonic disturbance, a scheme of adding windows combined with interpolation arithmetic was used to promote the detection accuracy; In the meanwhile, by means of the programming tool of Delphi, a good interface was designed. Through the experiment, we justify the device shows the well reliability and practicability.

  18. Psychological Disturbances and Quality of Life in Obese and Infertile Women and Men

    PubMed Central

    Kocełak, Piotr; Chudek, Jerzy; Naworska, Beata; Bąk-Sosnowska, Monika; Kotlarz, Barbara; Mazurek, Monika; Madej, Paweł; Skrzypulec-Plinta, Violetta; Skałba, Piotr; Olszanecka-Glinianowicz, Magdalena

    2012-01-01

    Anovulatory cycles and endometriosis are the main causes of female infertility. The most frequently anovulatory cycles are related to polycystic ovary syndrome (PCOS) commonly associated with obesity and hormonal disturbances in the course of obesity. Recently published studies revealed that infertility affects about one in six couples during their lifetime and is more frequent in obese. Obesity is also associated with male infertility related to erectile dysfunction, hormonal disturbances and lower semen quality. Any of these above mentioned disorder is the important risk factor of psychological disturbances and poor quality of life among women and men in the reproductive age. On the other hand the mood disorders may exacerbate the hormonal disturbances and worsen the effectiveness of infertility management. Infertility, its therapy with accompanying psychological disturbances may also significantly affect the partners relationships. The review summarize the results described in the current literature on the association between obesity and infertility and psychological disturbances as well as their impact on quality of life and sexual functioning in women and men. Moreover, the impact of infertility and psychological disturbances on partners relationships is discussed. PMID:22844280

  19. Disturbance road adaptive driving control of power-assisted wheelchair using fuzzy inference.

    PubMed

    Seki, Hirokazu; Kiso, Atsushi

    2011-01-01

    This paper describes a novel driving control scheme of electric power-assisted wheelchairs for assistive driving on various large disturbance roads. The "electric power-assisted wheelchair" which assists the driving force by electric motors is expected to be widely used as a mobility support system for elderly people and disabled people; however, there are lots of large disturbance roads such as uphill roads and rough roads and operators need to row the hand-rims with the larger power load on such roads in order to obtain the enough driving velocity. For example the wheelchair might move backward on uphill roads due to the driving torque shortage. Therefore this study proposes a fuzzy algorithm based adaptive control scheme in order to realize the assistive driving without the operator's power load on large disturbance roads. The proposed fuzzy rules are designed from the driving distance information and the control parameters are inferred by the fuzzy algorithm. The assisted torque can be adjusted so that the enough distance and velocity are kept even on large disturbance roads. Driving experimental results are provided to verify the effectiveness of the proposed control system.

  20. Childhood abuse is associated with stress-related sleep disturbance and poor sleep quality in pregnancy

    PubMed Central

    Gelaye, Bizu; Kajeepeta, Sandhya; Zhong, Qiu-Yue; Borba, Christina P.C.; Rondon, Marta B.; Sánchez, Sixto E.; Henderson, David C.; Williams, Michelle A.

    2015-01-01

    Objectives Childhood abuse is associated with increased risks of adult psychiatric disorders and physical health conditions. Accumulating evidence documents associations of childhood abuse with sleep disturbances in adulthood. However, to date, no study has evaluated associations of childhood abuse and sleep disturbances among pregnant women. Methods This cross-sectional study included 634 pregnant Peruvian women. In-person interviews were conducted in early pregnancy to collect information regarding socio-demographic characteristics, history of childhood abuse, and complaints of sleep disturbances. Spanish language version of the Ford Insomnia Response to Stress Test (FIRST-S) and the Pittsburgh Sleep Quality Index (PSQI-S) were used to assess stress-related sleep disturbance and sleep quality, respectively. Logistic regression was used to estimate adjusted odds ratios (aOR) and 95% confidence intervals (95% CIs). Results Women who experienced any childhood abuse had a 1.65-fold increased odds of stress-related sleep disturbance (aOR=1.65; 95% CI: 1.15–2.38) and 2.11-fold increased odds of poor sleep quality during early pregnancy (aOR=2.11; 95% CI: 1.35–3.30) as compared with women who reported no abuse. Compared with women who reported no childhood abuse, those who reported both physical and sexual abuse during childhood were more than twice as likely to suffer from stress-related sleep disturbance (aOR=2.26; 95% CI:1.44–3.53) and poor sleep quality (aOR=2.43; 95% CI:1.45–4.09). Conclusions A history of childhood abuse is associated with increased odds of stress-related sleep disturbance and poor sleep quality during pregnancy. These findings, if replicated, should be used to inform the development of trauma-informed care for such sleep disturbances induced by childhood trauma. PMID:26429757

  1. Childhood abuse is associated with stress-related sleep disturbance and poor sleep quality in pregnancy.

    PubMed

    Gelaye, Bizu; Kajeepeta, Sandhya; Zhong, Qiu-Yue; Borba, Christina P C; Rondon, Marta B; Sánchez, Sixto E; Henderson, David C; Williams, Michelle A

    2015-10-01

    Childhood abuse is associated with increased risks of adult psychiatric disorders and physical health conditions. Mounting evidence documents associations of childhood abuse with sleep disturbances in adulthood. However, to date, no study has evaluated associations of childhood abuse and sleep disturbances among pregnant women. This cross-sectional study included 634 pregnant Peruvian women. To collect information regarding socio-demographic characteristics, history of childhood abuse, and complaints of sleep disturbances, face-to-face interviews were conducted with women in early pregnancy. Ford Insomnia Response to Stress Test (FIRST-S) and the Pittsburgh Sleep Quality Index (PSQI-S), translated from English to Spanish, were used to assess stress-related sleep disturbance and sleep quality, respectively. Logistic regression was used to estimate adjusted odds ratios (aOR) and 95% confidence intervals (95% CIs). Women who experienced any childhood abuse had a 1.65-fold increased odds of stress-related sleep disturbance (aOR = 1.65; 95% CI: 1.15-2.38) and 2.11-fold increased odds of poor sleep quality during early pregnancy (aOR = 2.11; 95% CI: 1.35-3.30) as compared with women who reported no abuse. Women who reported both physical and sexual abuse during childhood were more than twice as likely to suffer from stress-related sleep disturbance (aOR = 2.26; 95% CI: 1.44-3.53) and poor sleep quality (aOR = 2.43; 95% CI: 1.45-4.09) in comparison to women who reported no childhood abuse. A history of childhood abuse is associated with increased odds of stress-related sleep disturbance and poor sleep quality during pregnancy. These findings, if replicated, should be used to inform the development of trauma-informed care for such sleep disturbances induced by childhood trauma. Copyright © 2015 Elsevier B.V. All rights reserved.

  2. Sleep disturbance, obesity, physical fitness and quality of life in older women: EXERNET study group.

    PubMed

    Moreno-Vecino, B; Arija-Blázquez, A; Pedrero-Chamizo, R; Gómez-Cabello, A; Alegre, L M; Pérez-López, F R; González-Gross, M; Casajús, J A; Ara, I

    2017-02-01

    To investigate the association between physical fitness, obesity, health related quality of life (HRQoL) and sleep disturbance in 463 community-dwelling older Spanish women (66-91 years of age). Cross-sectional study. Sleep disturbance was assessed with the Jenkins Sleep Scale. Active and sedentary behaviors were recorded by standardized questionnaires. HRQoL was assessed with the EuroQoL-5D. Anthropometric measurements were obtained using standardized techniques. Body fat was measured using bioelectrical impedance. Physical fitness was evaluated by a set of eight tests. Sleep disturbance was reported by 45.1% of women, being associated with higher body mass index (p < 0.05) and waist circumference (p < 0.01). Presence of insomnia was inversely associated with physical fitness. Women in the upper tertile of fitness index had 92.0% lower risk of sleep disturbance as compared to the lower tertile (p = 0.08), while women in the highest tertile of upper body strength had 76.4% lower risk of sleep disturbance as compared to the lower tertile (p < 0.05). Women without sleep disturbance showed better HRQoL. Sleep disturbance was associated with central obesity, lower physical fitness and reduced HRQoL. Interventions involving weight management and improvement of physical fitness may contribute to better sleep quality in older women.

  3. Sleep disturbances and quality of life in postoperative management after esophagectomy for esophageal cancer

    PubMed Central

    2014-01-01

    Background The aims of this prospective study were to analyze the predictors of postoperative sleep disturbance after esophagectomy for cancer and to identify patients at risk for postoperative hypnotic administration. Methods Sixty two consecutive patients who underwent cancer-related esophagectomy were enrolled in this study from May 2011 to February 2012. Data about perioperative management, postoperative complications, ICU stay, and vasopressor, hypnotic, and painkiller administration were retrieved. The EORTC QLQ-C30 was used and global quality of life (QL2 item) and sleep disturbance (SL item) were the primary endpoints. Univariate and multivariate analyses were performed. Results Postoperative request of hypnotics independently predicted bad quality of life outcome. Sleep disturbance after esophagectomy was independently predicted by the duration of dopamine infusion in the ICU and the daily request of benzodiazepines. Even in this case, only sleep disturbance at diagnosis revealed to be an independent predictor of hypnotic administration need. ROC curve analysis showed that sleep disturbance at diagnosis was a good predictor of benzodiazepine request (AUC = 73%, P = 0.02). Conclusions The use of vasopressors in the ICU affects sleep in the following postoperative period and the use of hypnotics is neither completely successful nor lacking in possible consequences. Sleep disturbance at diagnosis can successfully predict patients who can develop sleep disturbance during the postoperative period. PMID:24886219

  4. Electric Power quality Analysis in research reactor: Impacts on nuclear safety assessment and electrical distribution reliability

    SciTech Connect

    Touati, Said; Chennai, Salim; Souli, Aissa

    2015-07-01

    The increased requirements on supervision, control, and performance in modern power systems make power quality monitoring a common practise for utilities. Large databases are created and automatic processing of the data is required for fast and effective use of the available information. Aim of the work presented in this paper is the development of tools for analysis of monitoring power quality data and in particular measurements of voltage and currents in various level of electrical power distribution. The study is extended to evaluate the reliability of the electrical system in nuclear plant. Power Quality is a measure of how well a system supports reliable operation of its loads. A power disturbance or event can involve voltage, current, or frequency. Power disturbances can originate in consumer power systems, consumer loads, or the utility. The effect of power quality problems is the loss power supply leading to severe damage to equipments. So, we try to track and improve system reliability. The assessment can be focused on the study of impact of short circuits on the system, harmonics distortion, power factor improvement and effects of transient disturbances on the Electrical System during motor starting and power system fault conditions. We focus also on the review of the Electrical System design against the Nuclear Directorate Safety Assessment principles, including those extended during the last Fukushima nuclear accident. The simplified configuration of the required system can be extended from this simple scheme. To achieve these studies, we have used a demo ETAP power station software for several simulations. (authors)

  5. Impact of landscape disturbance on the quality of terrestrial sediment carbon in temperate streams

    NASA Astrophysics Data System (ADS)

    Fox, James F.; Ford, William I.

    2016-09-01

    Recent studies have shown the super saturation of fluvial networks with respect to carbon dioxide, and the concept that the high carbon dioxide is at least partially the result of turnover of sediment organic carbon that ranges in age from years to millennia. Currently, there is a need for more highly resolved studies at stream and river scales that enable estimates of terrestrial carbon turnover within fluvial networks. Our objective was to develop a new isotope-based metric to estimate the quality of sediment organic carbon delivered to temperate streams and to use the new metric to estimate carbon quality across landscape disturbance gradients. Carbon quality is defined to be consistent with in-stream turnover and our metric is used to measure the labile or recalcitrant nature of the terrestrial-derived carbon within streams. Our hypothesis was that intensively-disturbed landscapes would tend to produce low quality carbon because deep, recalcitrant soil carbon would be eroded and transported to the fluvial system while moderately disturbed or undisturbed landscapes would tend to produce higher quality carbon from well-developed surface soils and litter. The hypothesis was tested by applying the new carbon quality metric to 15 temperate streams with a wide range of landscape disturbance levels. We find that our hypothesis premised on an indirect relationship between the extent of landscape disturbance and the quality of sediment carbon in streams holds true for moderate and high disturbances but not for un-disturbed forests. We explain the results based on the connectivity, or dis-connectivity, between terrestrial carbon sources and pathways for sediment transport. While pathways are typically un-limited for disturbed landscapes, the un-disturbed forests have dis-connectivity between labile carbon of the forest floor and the stream corridor. Only in the case when trees fell into the stream corridor due to severe ice storms did the quality of sediment carbon

  6. Modeling the Impacts of Geomagnetic Disturbances on the New York State Power Transmission System

    NASA Astrophysics Data System (ADS)

    Ouedraogo, D.; Castillo, O. L.; Mohamed, A.; Damas, M. C.; Ngwira, C. M.

    2015-12-01

    Our society today relies heavily on electricity in order to meet its essential basic needs. However, to meet the rising demands for this energy, all power companies require smooth and efficient delivery of services to the consumers. The US power grid is a complex electrical apparatus that has well known sensitivities to space weather disturbances. Events produced by space weather includes solar storms or geomagnetic disturbances [GMD]. The propagation of such events in the direction of Earth perturbs the electric currents in the magnetosphere and the ionosphere, causing a unique effect known as a Geomagnetically Induced Current [GIC]. GICs are known to saturate and overheat transformers in the power grid, threatening the safe operation of the power system. A GMD induces a geoelectric field in high-voltage and extra high-voltage transmission circuits. This geoelectric field represents electromotive force, and causes GICs to circulate through transmission circuits and transformers. Power models are being developed using MATLAB/Simulink® software to simulate the propagation of GIC flows in a power system, while using New York State (NYS) power transmission network as an example. We will present results of the models used to assess the impacts of possible GMD strikes on the various parts of the power network.

  7. Analysis of 12 electric power system outages/disturbances impacting the Florida Peninsula

    SciTech Connect

    1980-12-01

    Between January 3 and August 3, 1979, there were 12 occasions on which electric power was curtailed or public appeals were made to customers to reduce their load in Peninsular Florida due to bulk electric power supply problems. The Economic Regulatory Administration (ERA) of the US DOE, pursuant to its electric power supply adequacy and reliability responsibilities, initiated a twofold analysis of the bulk power supply situation in Florida. The first phase of the analysis evaluated the technical and engineering aspects of the overall Florida bulk power supply system with special attention given to the City of Jacksonville's electric system. The second phase evaluated the socioeconomic impacts of the bulk power supply outages on residential customers in Jacksonville. The 12 disturbances are described and a comparative analysis of the causes is presented. (LCL)

  8. A Review on Research Methods of Disturbance Propagation in Large-Scale Power Grids

    NASA Astrophysics Data System (ADS)

    Liu, Xing; He, Jingbo; Ding, Jian; Yang, Mingyu; Wang, Jing; Tian, Chunzheng; Wang, Shiqian

    2017-05-01

    Nowadays, our country has entered the era of UHV and large-scale power grid, the scale of power grid is increasing continuously, which has contributed to develop the optimal allocation of resources adequately, meanwhile, the possibilities of the occurrence of large-scale blackouts increased, posing a new challenge for security and stability controlling for power system. Therefore, a growing number of scholars began to focus on the process of disturbance propagation, which can help us gain deeper insight into the performance of power system and offer some valuable suggestion for controlling measurements. Based on the current research status about disturbance propagation, research methods used to reveal the mechanism of disturbance propagation were classified into five types: time-domain simulation methods and their counterparts with transient energy function, linearization analysis, flow analysis algorithms and graph theory analysis methods included. Meanwhile, every existing method was described in detail from four different aspects: concept, present status and hotspots, critical difficulties, future direction. Finally, the future development trend in the field is focused.

  9. Sleep quality disturbances and cognitive functioning in elderly patients with COPD.

    PubMed

    Cleutjens, Fiona A H M; Pedone, Claudio; Janssen, Daisy J A; Wouters, Emiel F M; Incalzi, Raffaele A

    2016-07-01

    Information about the association between cognitive functions, such as copying function, and sleep disturbances in patients with chronic obstructive pulmonary disease (COPD) is lacking. This cross-sectional observational study aimed to investigate the association between copying function and self-reported sleep quality disturbances and disease severity in an elderly COPD population. Cognitive function performances, assessed using the Mini-Mental State Examination, were compared in 562 ambulatory COPD patients with and without sleep disturbances; assessed using the Established Populations for Epidemiologic Studies of the Elderly questionnaire; and stratified by Global Initiative for Chronic Obstructive Lung Disease (GOLD) grades. Sleep disturbances overall were not correlated with cognitive functioning. A trend was revealed towards worse design copying in patients with sleep disturbances overall. GOLD I patients with difficulties falling asleep and nocturnal awakenings had worse copying ability compared to GOLD I patients without these sleep disturbances. Copying ability was worse for GOLD III than GOLD I, orientation was worse for GOLD II than GOLD I and language was worse for GOLD II and III than GOLD I. To conclude, sleep disturbances seem to be a weak correlate of cognitive functioning, and are not a marker of disease severity.

  10. Sleep quality disturbances and cognitive functioning in elderly patients with COPD

    PubMed Central

    Pedone, Claudio; Janssen, Daisy J.A.; Wouters, Emiel F.M.; Incalzi, Raffaele A.

    2016-01-01

    Information about the association between cognitive functions, such as copying function, and sleep disturbances in patients with chronic obstructive pulmonary disease (COPD) is lacking. This cross-sectional observational study aimed to investigate the association between copying function and self-reported sleep quality disturbances and disease severity in an elderly COPD population. Cognitive function performances, assessed using the Mini-Mental State Examination, were compared in 562 ambulatory COPD patients with and without sleep disturbances; assessed using the Established Populations for Epidemiologic Studies of the Elderly questionnaire; and stratified by Global Initiative for Chronic Obstructive Lung Disease (GOLD) grades. Sleep disturbances overall were not correlated with cognitive functioning. A trend was revealed towards worse design copying in patients with sleep disturbances overall. GOLD I patients with difficulties falling asleep and nocturnal awakenings had worse copying ability compared to GOLD I patients without these sleep disturbances. Copying ability was worse for GOLD III than GOLD I, orientation was worse for GOLD II than GOLD I and language was worse for GOLD II and III than GOLD I. To conclude, sleep disturbances seem to be a weak correlate of cognitive functioning, and are not a marker of disease severity. PMID:27957482

  11. Analysis of ionospheric disturbances associated with powerful cyclones in East Asia and North America

    NASA Astrophysics Data System (ADS)

    Li, Wang; Yue, Jianping; Yang, Yang; Li, Zhen; Guo, Jinyun; Pan, Yi; Zhang, Kefei

    2017-08-01

    East Asia and North America are the regions most heavily affected by powerful cyclones. In this paper we investigate the morphological characteristics of ionospheric disturbances induced by cyclones in different continents. The global ionosphere map supplied by the Center for Orbit Determination in Europe (CODE), International Reference Ionosphere Model (IRI) 2012, and Wallops Island ionosonde station data are used to analyse the ionospheric variations during powerful typhoons/hurricanes in East Asia and North America, respectively. After eliminating the ionospheric anomalies due to the solar-terrestrial environment, the total electron content (TEC) time series over the point with maximum wind speed is detected by the sliding interquartile range method. The results indicate that significant ionospheric disturbances are observed during powerful tropical cyclones in East Asia and North America, respectively, and that all the ionospheric anomalies are positive. In addition, the extent and magnitude of travelling ionospheric disturbances are associated with the category of tropical cyclone, and the extent of TEC anomalies in longitude is more pronounced than that in latitude. Furthermore, the maximum ionospheric anomaly does not coincide with the eye of the storm, but appears in the region adjacent to the centre. This implies that ionospheric disturbances at the edges of cyclones are larger than those in the eye of the winds. The phenomenon may be associated with the gravity waves which are generated by strong convective cells that occur in the spiral arms of tropical cyclones. This comprehensive analysis suggests that the presence of powerful typhoons/hurricanes may be a possible source mechanism for ionospheric anomalies.

  12. Microgrids and Heterogeneous Power Quality and Reliability

    SciTech Connect

    LaCommare, Kristina; Marnay, Chris

    2007-10-01

    This paper describes two stylized alternative visions of how the power system might evolve to meet future requirements for the high quality electricity service that modern digital economies demand, a supergrids paradigm and a dispersed paradigm. Some of the economics of the dispersed vision are explored, and perspectives are presented on both the choice of homogeneous universal power quality upstream in the electricity supply chain and on the extremely heterogeneous requirements of end-use loads. It is argued that meeting the demanding requirements of sensitive loads by local provision of high quality power may be more cost effective than increasing the quality of universal homogeneous supply upstream in the legacy grid. Finally, the potential role of microgrids in delivering heterogeneous power quality is demonstrated by reference to two ongoing microgrid tests in the U.S. and Japan.

  13. The role of young, recently disturbed upland hardwood forest as high quality food patches

    Treesearch

    Cathryn H. Greenberg; Roger W. Perry; Craig A. Harper; Douglas J. Levey; John M. McCord

    2011-01-01

    Young (1-10 year post-disturbance) upland hardwood forests function as high-quality food patches by providing abundant fruit, and nutritious foliage and flowers that attract pollinating and foliar arthropods and support high populations of small mammals that, in turn, are prey for numerous vertebrate predators. Reductions in basal area increase light penetration to the...

  14. Quality of Mother-Infant Interactions in Maternal Emotional Disturbance: A Pilot Study

    ERIC Educational Resources Information Center

    Singhal, Meghna; Sinha, U. K.

    2012-01-01

    Aim: The present study aimed to examine the quality of mother-infant interactions in emotionally disturbed (ED) mothers. Method: 20 mothers with or without ED and their infants (12-24 months) participated in the study, which involved the mothers interacting with their infants with a toy in a structured play situation. These interactions were…

  15. Power analysis as a tool to identify statistically informative indicators for monitoring coral reef disturbances.

    PubMed

    Van Wynsberge, Simon; Gilbert, Antoine; Guillemot, Nicolas; Heintz, Tom; Tremblay-Boyer, Laura

    2017-07-01

    Extensive biological field surveys are costly and time consuming. To optimize sampling and ensure regular monitoring on the long term, identifying informative indicators of anthropogenic disturbances is a priority. In this study, we used 1800 candidate indicators by combining metrics measured from coral, fish, and macro-invertebrate assemblages surveyed from 2006 to 2012 in the vicinity of an ongoing mining project in the Voh-Koné-Pouembout lagoon, New Caledonia. We performed a power analysis to identify a subset of indicators which would best discriminate temporal changes due to a simulated chronic anthropogenic impact. Only 4% of tested indicators were likely to detect a 10% annual decrease of values with sufficient power (>0.80). Corals generally exerted higher statistical power than macro-invertebrates and fishes because of lower natural variability and higher occurrence. For the same reasons, higher taxonomic ranks provided higher power than lower taxonomic ranks. Nevertheless, a number of families of common sedentary or sessile macro-invertebrates and fishes also performed well in detecting changes: Echinometridae, Isognomidae, Muricidae, Tridacninae, Arcidae, and Turbinidae for macro-invertebrates and Pomacentridae, Labridae, and Chaetodontidae for fishes. Interestingly, these families did not provide high power in all geomorphological strata, suggesting that the ability of indicators in detecting anthropogenic impacts was closely linked to reef geomorphology. This study provides a first operational step toward identifying statistically relevant indicators of anthropogenic disturbances in New Caledonia's coral reefs, which can be useful in similar tropical reef ecosystems where little information is available regarding the responses of ecological indicators to anthropogenic disturbances.

  16. Analysis of electrical power system disturbance and outage in Garland and Greenville, Texas, June 26, 1980

    SciTech Connect

    1981-01-01

    On June 26, 1980, the municipal electric systems of Garland and Greenville, Texas, both experienced total system outages which lasted from 2:01 p.m. until 10:15 p.m. that evening. In order to understand more fully the causes of this disturbance, a technical analysis was initiated to consider: the status of each of the involved utility systems prior to initiation of the disturbance; the sequence of events which occurred between the initial event precipitating the interruption and the total system outages; the restorative procedures implemented by the involved systems; and any procedural changes or facility modifications that should be considered by the involved systems. Each of these items is discussed, and recommendations are made for developing an emergency operation plan, for isolating the two distribution systems when a significant system frequency excursion occurs, and for developing power pool operating criteria and contingency plans. (LCL)

  17. Off-grid power quality: Impacts, analysis and solutions

    NASA Astrophysics Data System (ADS)

    Gautam, Arjun

    Good power quality is a critical factor for the reliable operation of electrical loads in a power system. However, the current drawn by many electronic devices and non-linear loads are non-sinusoidal, which can result in a poor power quality, particularly in off-grid power systems. Poor power quality is characterized by electrical disturbances such as transients, sags, swells, harmonics and even interruptions in the power supply. Off-grid power systems worldwide struggle with system failures and equipment damage due to poor power quality. To better understand off-grid system failures and equipment damage issues, the current and voltage characteristics of a number of electrical devices in two off-grid homes, one using a pure sine wave inverter and the other using a modified sine wave inverter, were recorded with a Fluke 43B power quality analyzer, and the devices' impact on the power quality of the off-grid systems was analyzed. The off-grid power quality data were then compared with data from a grid-connected apartment, to help identify the issues that were specific to off-grid systems. The MATLAB/Simulink software was used to model and analyze power quality for additional configurations of the two off-grid systems mentioned above. Strategies to mitigate the worst power quality issues were selected based upon their function and cost, and a few were tested in an off-grid system. Selection of an inverter was found to be important because not all devices are supported by each type of inverter. For example, the refrigerator in the off-grid home with a modified sine wave inverter produced a significant amount of current and voltage harmonics far above standards. In fact, this type of inverter does not support a number of sensitive devices including motors, refrigerators, microwave ovens, fluorescent lights, battery chargers etc. The major issues for the degradation of power quality in the off-grid system using a pure sine wave inverter were the current harmonics

  18. E-Learning for Power Quality

    NASA Astrophysics Data System (ADS)

    Bauer, Pavol; Nagy, Istvan

    E-learning with pre-solved animations can provide a better understanding of the status and different network options, compared to complex simulation or a set of equations. In this paper, examples of such animations for e-learning for power quality are presented. Different network options in a centralized or distributed power system and power electronics based compensators are introduced in the form of a new web-based, software learning tool. Power flow congestion and the impact of power electronic compensators on the system, including detailed operations of power electronic based compensators are presented. These compensators include SVCs, Statcom and UPFC presented in this paper. Using these animated tools, both system level and component level operation of these devices are presented. Further the frequent solutions of power factor correction (PFC) applied on low power level of several hundred watts are treated in the paper.

  19. Factors Affecting Source-Water Quality after Disturbance of Forests by Wildfire

    NASA Astrophysics Data System (ADS)

    Murphy, S. F.; Martin, D. A.; McCleskey, R. B.; Writer, J. H.

    2015-12-01

    Forests yield high-quality water supplies to communities throughout the world, in part because forest cover reduces flooding and the consequent transport of suspended and dissolved constituents to surface water. Disturbance by wildfire reduces or eliminates forest cover, leaving watersheds susceptible to increased surface runoff during storms and reduced ability to retain contaminants. We assessed water-quality response to hydrologic events for three years after a wildfire in the Fourmile Creek Watershed, near Boulder, Colorado, and found that hydrologic and geochemical responses downstream of a burned area were primarily driven by small, brief convective storms that had relatively high, but not unusual, rainfall intensity. Total suspended sediment, dissolved organic carbon, nitrate, and manganese concentrations were 10-156 times higher downstream of a burned area compared to upstream, and water quality was sufficiently impaired to pose water-treatment concerns. The response in both concentration and yield of water-quality constituents differed depending on source availability and dominant watershed processes controlling the constituent. For example, while all constituent concentrations were highest during storm events, annual sediment yields downstream of the burned area were controlled by storm events and subsequent mobilization, whereas dissolved organic carbon yields were more dependent on spring runoff from upstream areas. The watershed response was affected by a legacy of historical disturbance: the watershed had been recovering from extensive disturbance by mining, railroad and road development, logging, and fires in the late 19th and early 20th centuries, and we observed extensive erosion of mine waste in response to these summer storms. Therefore, both storm characteristics and historical disturbance in a burned watershed must be considered when evaluating the role of wildfire on water quality.

  20. Simulation of the imaging quality of ground-based telescopes affected by atmospheric disturbances

    NASA Astrophysics Data System (ADS)

    Ren, Yubin; Kou, Songfeng; Gu, Bozhong

    2014-08-01

    Ground-based telescope imaging model is developed in this paper, the relationship between the atmospheric disturbances and the ground-based telescope image quality is studied. Simulation of the wave-front distortions caused by atmospheric turbulences has long been an important method in the study of the propagation of light through the atmosphere. The phase of the starlight wave-front is changed over time, but in an appropriate short exposure time, the atmospheric disturbances can be considered as "frozen". In accordance with Kolmogorov turbulence theory, simulating atmospheric disturbances of image model based on the phase screen distorted by atmospheric turbulences is achieved by the fast Fourier transform (FFT). Geiger mode avalanche photodiode array (APD arrays) model is used for atmospheric wave-front detection, the image is achieved by inversion method of photon counting after the target starlight goes through phase screens and ground-based telescopes. Ground-based telescope imaging model is established in this paper can accurately achieve the relationship between the quality of telescope imaging and monolayer or multilayer atmosphere disturbances, and it is great significance for the wave-front detection and optical correction in a Multi-conjugate Adaptive Optics system (MCAO).

  1. Anthropogenic disturbance on sediment transport processes in the tidal power plant

    NASA Astrophysics Data System (ADS)

    Ha, Ho Kyung; Kim, Jong-wook; Woo, Seung-Buhm; Kwon, Hyo Keun

    2017-04-01

    A series of in-situ mooring observations have been conducted to investigate the anthropogenic disturbance of sediment transport processes in the Sihwa tidal power plant (TPP). The mooring data show that the profiels of velocity and suspended sediment concentration (SSC) were significantly disturbed over the various time scales. On the short-term (flood-ebb) time scale, resuspension of bottom sediment is mainly controlled by the strong jet-flow (>2 m/s) and anticlockwise rotating vortex associated with the artificial discharge. During ebb phase, the strong flow resulted in suspension of high-concentration near-bed sediment and seaward transport of the suspended sediment. After turning to flood phase, the vortex produced secondary SSC peaks, transporting the suspended sediment toward the TPP. The most active suspension of bottom sediment predominantly occurred during 1-2 hr immediately after the start of artificial discharge. On the fortnightly (spring-neap) time scale, SSC during spring tide was approximately 2-5 times higher than that during neap tide. During the presentation, it will be discussed how the periodic artificial discharge can disturb the responses of SSC in the TPP.

  2. Implementation and performance results of neural network for power quality event detection

    NASA Astrophysics Data System (ADS)

    Huang, Weijian; Tian, Wenzhi

    2008-10-01

    A novel method to detect power quality event in distributed power system combing wavelet network with the improved back-propagation algorithm is presented. The paper tries to explain to design complex supported orthogonal wavelets by compactly supported orthogonal real wavelets, and then explore the extraction of disturbance signal to obtain the feature information, and finally propose several novel wavelet combined information to analyze the disturbance signal, superior to real wavelet analysis result. The feature obtained from WT coefficients are inputted into wavelet network for power quality disturbance pattern recognition. The power quality disturbance recognition model is established and the improved back-propagation algorithm is used to fulfill the network parameter initialization. By means of choosing enough samples to train the recognition model, the type of disturbance can be obtained when signal representing fault is inputted to the trained network. The results of simulation analysis show that the complex wavelet transform combined with wavelet network are more sensitive to signal singularity, and found to be significant improvement over current methods in real-time detection.

  3. Narrative quality and disturbance pre- and post-emotion-focused therapy for child abuse trauma.

    PubMed

    Mundorf, Elisabeth S; Paivio, Sandra C

    2011-12-01

    This study predicted that the quality of trauma narratives written before and following emotion-focused therapy for child abuse trauma would be positively associated with psychological disturbance before and following therapy. Narratives for 37 clients were coded for emotion words, temporal orientation, incoherence, and depth of experiencing. At pretreatment, negative emotion words and experiencing were correlated with abuse resolution, r(35) = -.36, and r(35) = -.34, respectively. At posttreatment, narrative incoherence was correlated with trauma symptoms, r(35) = .33, whereas present-future orientation and experiencing were correlated with abuse resolution, r(35) = -.37, and r(35) = -.31, respectively. Pretreatment incoherence was associated with posttreatment trauma symptoms, r(35) = .42, and pretreatment depth of experiencing was associated with posttreatment abuse resolution, r(35) = -.37. Results support narrative quality as an index of trauma disturbance.

  4. Effects of music listening on stress, anxiety, and sleep quality for sleep-disturbed pregnant women.

    PubMed

    Liu, Yu-Hsiang; Lee, ChihChen Sophia; Yu, Chen-Hsiang; Chen, Chung-Hey

    2016-01-01

    Prenatal sleep disturbance has been associated with undesirable birthing outcomes. To determine the effectiveness of listening to music at home in improving sleep quality, 121 Taiwanese pregnant women with poor sleep quality (Pittsburgh Sleep Quality Index [PSQI] score > 5) were systematically assigned, with a random start to music listening (n = 61) or control (n = 60) group. Participants in the music listening group self-regulated listening to music in addition to receiving general prenatal care similar to that in the control group for 2 weeks. The PSQI and State-Anxiety Inventory were used to assess outcomes. ANCOVA analyses were used with the pretest scores as covariates and showed significant improvement in sleep quality, stress, and anxiety in the music listening group compared with the control group. The most frequently used music genre by participants in the experimental group was lullabies, followed by classical music and crystal baby music. This study supported the theory that 2-week music listening interventions may reduce stress, anxiety, and yield better sleep quality for sleep-disturbed pregnant women. The analysis of participants' journals also implied that the expectant mothers' choices of musical genres may correlate more with perceived prenatal benefits or the desire to interact with their unborn child.

  5. Quality assurance program for isotopic power systems

    SciTech Connect

    Hannigan, R.L.; Harnar, R.R.

    1982-12-01

    This report summarizes the Sandia National Laboratories Quality Assurance Program that applies to non-weapon (reimbursable) Radioisotopic Thermoelectric Generators. The program has been implemented over the past 16 years on power supplies used in various space and terrestrial systems. The quality assurance (QA) activity of the program is in support of the Department of Energy, Office of Space Nuclear Projects. Basic elements of the program are described in the report and examples of program decumentation are presented.

  6. Quality assurance program for isotopic power systems

    NASA Astrophysics Data System (ADS)

    Hannigan, R. L.; Harnar, R. R.

    1982-12-01

    The Sandia National Laboratories Quality Assurance Program that applies to non-weapon (reimbursable) Radioisotopic Thermoelectric Generators is summarized. The program was implemented over the past 16 years on power supplies used in various space and terrestrial systems. The quality assurance (QA) activity of the program is in support of the Department of Energy, Office of Space Nuclear Projects. Basic elements of the program are described and examples of program documentation are presented.

  7. Sleep Quality and Body Mass Index in College Students: The Role of Sleep Disturbances

    PubMed Central

    Vargas, Perla A.; Flores, Melissa; Robles, Elias

    2014-01-01

    Objective Obesity and its comorbidities have emerged as a leading public health concern. Our aim was to explore the relationship between BMI and sleep patterns, including duration and disturbances. Methods A convenience sample of 515 college students completed an online survey consisting of the Pittsburgh Sleep Quality Index (PSQI), and self-reported height and weight to calculate Body Mass Index (BMI). Univariate and multivariate logistic regression analyses were performed using components of the PSQI as predictors of overweight (BMI ≥ 25). Results One-third of the participants had BMI ≥ 25, and 51% were poor-quality sleepers (PSQI > 5). Controlling for age and sex, only sleep disturbances were associated to overweight (OR=1.66, 95% CI: 1.08-2.57). Conclusions Sleep disturbances, rather than sleep duration predicted overweight among young adults; this is consistent with the most recent evidence in the literature. These findings support expanding the scope of wellness programs to promote healthy sleep among students. PMID:24933244

  8. Dynamics of sediment disturbance by periodic artificial discharges from the world's largest tidal power plant

    NASA Astrophysics Data System (ADS)

    Kim, J. W.; Ha, H. K.; Woo, S. B.

    2017-05-01

    To investigate the dynamics of sediment disturbance near the world's largest Sihwa tidal power plant (TPP), two mooring observations have been conducted. The mooring results show that current velocity and suspended sediment concentration (SSC) were significantly disturbed over various time scales. On the short-term (flood-ebb) time scale, resuspension of bottom sediment is mainly controlled by the strong jet-flow (>2 m s-1) and resulting anticlockwise rotating vortex associated with the artificial discharge. During ebb phase, the strong flow resulted in suspension of high-concentration near-bed sediment and seaward transport of the suspended sediment. After turning to flood phase, the vortex produced secondary SSC peaks, transporting the suspended sediment toward the Sihwa TPP. The most active suspension of bed sediment predominantly occurred during 1-2 h immediately after the start of artificial discharge. For the fortnightly (spring-neap) time scale, SSC during spring tide was approximately 2-5 times higher than that during neap tide. During the combined period of ebb and spring tides, in particular, the periodic artificial discharge can enhance the responses of SSC in the vicinity of Sihwa TPP.

  9. Matrix quality and disturbance frequency drive evolution of species behavior at habitat boundaries.

    PubMed

    Martin, Amanda E; Fahrig, Lenore

    2015-12-01

    Previous theoretical studies suggest that a species' landscape should influence the evolution of its dispersal characteristics, because landscape structure affects the costs and benefits of dispersal. However, these studies have not considered the evolution of boundary crossing, that is, the tendency of animals to cross from habitat to nonhabitat ("matrix"). It is important to understand this dispersal behavior, because of its effects on the probability of population persistence. Boundary-crossing behavior drives the rate of interaction with matrix, and thus, it influences the rate of movement among populations and the risk of dispersal mortality. We used an individual-based, spatially explicit model to simulate the evolution of boundary crossing in response to landscape structure. Our simulations predict higher evolved probabilities of boundary crossing in landscapes with more habitat, less fragmented habitat, higher-quality matrix, and more frequent disturbances (i.e., fewer generations between local population extinction events). Unexpectedly, our simulations also suggest that matrix quality and disturbance frequency have much stronger effects on the evolution of boundary crossing than either habitat amount or habitat fragmentation. Our results suggest that boundary-crossing responses are most affected by the costs of dispersal through matrix and the benefits of escaping local extinction events. Evolution of optimal behavior at habitat boundaries in response to the landscape may have implications for species in human-altered landscapes, because this behavior may become suboptimal if the landscape changes faster than the species' evolutionary response to that change. Understanding how matrix quality and habitat disturbance drive evolution of behavior at boundaries, and how this in turn influences the extinction risk of species in human-altered landscapes should help us identify species of conservation concern and target them for management.

  10. Speech disturbances and quality of life in schizophrenia: differential impacts on functioning and life satisfaction.

    PubMed

    Tan, Eric J; Thomas, Neil; Rossell, Susan L

    2014-04-01

    Speech disturbances in schizophrenia impact on the individual's communicative ability. Although they are considered a core feature of schizophrenia, comparatively little work has been done to examine their impact on the life experiences of patients. This study aimed to examine the relationship between schizophrenia speech disturbances, including those traditionally known as formal thought disorder (TD), and quality of life (QoL). It assessed effects on functioning (objective QoL) and satisfaction (subjective QoL) concurrently, while controlling for the influence of neurocognition and depression. Fifty-four patients with schizophrenia/schizoaffective disorder were administered the MATRICS Consensus Cognitive Battery (MCCB), the PANSS, MADRS (with separate ratings for negative TD [verbal underproductivity] and positive TD [verbal disorganisation and pressured speech]) and Lehman's QOLI assessing both objective and subjective QoL. Ratings of positive and negative TD, depression, and general neurocognition were entered into hierarchical regressions to explore their relationship with both life functioning and satisfaction. Verbal underproductivity was a significant predictor of objective QoL, while pressured speech had a trend association with subjective QoL. This suggests a differential relationship between speech disturbances and QoL. Verbal underproductivity seems to affect daily functioning and relations with others, while pressured speech is predictive of satisfaction with life. The impact of verbal underproductivity on QoL suggests it to be an important target for rehabilitation in schizophrenia. Copyright © 2014 Elsevier Inc. All rights reserved.

  11. Systemic increase in blood flow in conditions of disturbed microcirculation after low-power laser irradiation

    NASA Astrophysics Data System (ADS)

    Schindl, Andreas; Schindl, Liesbeth

    1996-11-01

    As described earlier by our group, topical application of low power laser irradiation seems to have a systemic effect in terms of improving microcirculation in patients suffering from microangiopathic disorders. The aim of the presented study was to prove these clinical findings by measuring the skin temperature as a parameter of microcirculation suing an infrared-thermography-camera system. Patients who attended the Institute for Laser medicine between January and July 1996 and suffered from angiopathy of different origin were examined. The laser system used was a combined IR/HeNe- laser, power output 30mW, irradiation time was varied to keep the IED at a value of 20J/cm2. Irradiation was performed proximally to the affected area, the contralateral side being left untreated, IR-thermography was started after reaching adaption to the room temperature, with pictures of both extremities taken in 10 minute intervals during the irradiation and up to 45 minutes after stopping the irradiation. Results show a rise in temperature over the affected region as well as over the contralateral extremity, with maximal changes of up to + 3.0 degrees C. The improvement of blood flow started 15 min. after the onset of laser irradiation and persisted up to 45 min. after stopping the irradiation. The results obtained are in good accordance with findings of previously performed studies, undertaken with patients with autoimmune-angiopathies such as Buerger's disease. Therefore, we conclude that topical application of low power lasers is able to induce a systemic improvement of blood flow in conditions of disturbed microcirculation.

  12. Sleep disturbance, distress, and quality of life in ovarian cancer patients during the first year after diagnosis.

    PubMed

    Clevenger, Lauren; Schrepf, Andrew; Degeest, Koenraad; Bender, David; Goodheart, Michael; Ahmed, Amina; Dahmoush, Laila; Penedo, Frank; Lucci, Joseph; Thaker, Premal H; Mendez, Luis; Sood, Anil K; Slavich, George M; Lutgendorf, Susan K

    2013-09-01

    Sleep disturbance is a common clinical complaint of oncology patients and contributes to substantial morbidity. However, because most sleep studies have been cross-sectional, associations between sleep quality and distress in patients with ovarian cancer over time remain unclear. This prospective longitudinal study examined rates of sleep disturbance; contributions of depression, anxiety, and medication use in sleep disturbance; and associations between sleep quality and quality of life (QOL) during the first year after diagnosis among women with ovarian cancer. Women with a pelvic mass completed measures of sleep quality, depression, anxiety, and QOL before surgery. Those diagnosed with primary epithelial ovarian, fallopian tube, or peritoneal cancer repeated surveys at 6 months and 1 year after diagnosis. Mixed modeling was used to examine trajectories of psychosocial measures over time, as well as associations between changes in distress and sleep quality. Relationships between changes in sleep and QOL were also examined. The majority of patients reported disturbed global sleep (Pittsburgh Sleep Quality Index > 5) at all 3 time points. Medications for sleep and pain were associated with worse sleep at all time points. Greater increases in depression were associated with increased disturbances in sleep quality over time (P < .04). Worsening sleep was also associated with declines in QOL over time (P < .001). Sleep disturbance is common and persistent in women with ovarian cancer, and is linked to depressive symptoms and QOL. Pharmacologic treatment does not appear to adequately address this problem. Results highlight the need for ongoing screening and intervention for sleep disturbance in this population. Copyright © 2013 American Cancer Society.

  13. Final report on the development of a 2 MW/10 second battery energy storage system for power disturbance protection

    SciTech Connect

    1996-12-11

    Voltage sags, swells and momentary power interruptions lasting a few cycles to several seconds are common disturbances on utility power distribution systems. These disturbances are a result of normal utility recloser switching activity due in part to distribution system short circuits from natural causes such as lightning, rodents, traffic accidents, and current overloads. Power disturbances pose serious problems for many customers with critical, voltage sensitive equipment. Faults can interrupt a manufacturing process, cause PLC`s to initialize their programmed logic and restart equipment out of sequence, create computer data errors, interrupt communications, lockup PC keyboards and cause equipment to malfunction. These momentary disturbances result in billions of dollars of lost productivity annually due to downtime, cleanup, lost production and the loss of customer confidence in the business. This report describes prototype development work for a factory assembled 2 MW/10 Second Battery Energy Storage System. The system design includes (1) a modular battery energy storage system comprised of several strings of batteries-each string provided with an integral Power Conversion System (PCS), (2) an Electronic Selector Device (ESD) comprised of a solid state static switch with sensing and power switching controls, and utility interconnection termination bus bars, and (3) a separate isolation transformer to step-up PCS output voltage to interface directly with the distribution transformer serving the industrial or commercial customer. The system monitors the utility distribution system voltage for voltage sags, swells, and interruptions, switches the customer`s critical loads from utility power to the energy stored in the systems batteries and provides up to 2 MVA until the disturbance clears or up to 10 seconds. Once the ESD sensing circuits have confirmed that the utility is again stable, it seamlessly returns the critical load to the utility. 22 figs., 1 tab.

  14. Effect of catchment disturbance on seston quality and quantity in Brisbane Water, NSW

    NASA Astrophysics Data System (ADS)

    Paterson, K. J.; Schreider, M.; Zimmerman, K. D.

    2003-02-01

    The direct effect of catchment disturbance on water parameters and the quality and quantity of seston were investigated in Brisbane Water, NSW Australia. Nutrient concentrations, faecal coliform levels and seston quality and quantity varied among catchments in Brisbane Water. Three of the four major catchment creeks entering Brisbane Water are sourced from disturbed catchments (Erina, Narara and Kincumber Creeks), including both industrial and residential areas, while one is sourced from a relatively undisturbed catchment (Woy Woy Creek). Monitoring occurred during wet and dry weather. After rainfall, elevated levels of nitrite/nitrate (NO x) were recorded at the developed location at EC although the differences were not significant. Particulate nitrogen (PN) increased significantly at the developed locations at NC and EC after rainfall. The increases in these two forms of nitrogen after rainfall suggest non-point sources within the catchment. Ammonia (NH 3) concentrations were consistently higher at Erina Creek, even during dry weather suggesting a point source of NH 3 pollution. Variations in phosphate (PO 4) concentration among locations sampled were significant on only one occasion but no trends in the variation were apparent. Although not always significant, trends in total particulate matter (TPM), particulate inorganic matter (PIM) and particulate organic matter (POM) concentrations showed higher levels at developed locations, particularly after rainfall. The %POM was lower at developed locations than at Woy Woy Creek due to relatively greater increases in PIM. On some dates sampled, trends in seston quality measures indicated poorer quality seston associated with developed catchments (i.e. %PC, %PN, PC:Chl a, Chl a:TPM and PN:Chl a) but these were significant for only some tests. The PC:PN ratio, however, did not follow the same patterns as other seston quality indicators. By altering the quantity and quality of the seston, overdevelopment can potentially

  15. Sleep-wake disturbances in cancer patients: narrative review of literature focusing on improving quality of life outcomes.

    PubMed

    Dickerson, Suzanne S; Connors, Laurie M; Fayad, Ameera; Dean, Grace E

    2014-01-01

    Evidence suggests a high prevalence of sleep-wake disturbances in patients with cancer, occurring at diagnosis, during treatment, and continuing to survivorship. Yet associations between sleep-wake disturbances and the impact on quality of life outcomes is less clear. The purpose of this narrative review of the literature is to evaluate sleep-wake disturbances in patients with cancer, to describe the influence of poor sleep on quality of life as an outcome, and to evaluate the evidence to recommend future interventions. This review was guided by the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) approach. Four databases (CINAHL, MEDLINE, PsycINFO, and Embase) were searched using terms "cancer OR neoplasm", "sleep, sleep disturbance, sleep disorders or insomnia", and "quality of life"; the search included all years, English language, and peer-reviewed articles on research studies. Studies included measurements of sleep and quality of life in cancer patients at a minimum of two time points and demonstrated relationships between sleep and quality of life. Data were collected on date, patient demographics, cancer type and treatment, timeframe, design, measurement, variables, and results. This narrative review demonstrates that sleep-wake disturbance is a major problem/symptom in patients with cancer. Of the 18 studies included, measurement of sleep-related variables included objective and subjective measures; however, direct measurement of the associations between sleep and quality of life was not common. Cognitive behavioral therapy for insomnia and mind-body interventions demonstrated feasibility when implemented into cancer care settings. In addition, the majority of interventions exhibited moderate effectiveness in improving sleep-wake disturbance and quality of life outcomes. The studies predominantly reported that poor sleep negatively impacts quality of life. The intervention studies included nonpharmacologic interventions such as

  16. Robust Disturbance Observer-Based Feedback Linearization Control for a Research Reactor Considering a Power Change Rate Constraint

    NASA Astrophysics Data System (ADS)

    Eom, Myunghwan; Chwa, Dongkyoung; Baang, Dane

    2015-06-01

    This paper presents a robust disturbance observer-based feedback linearization control method using a fuzzy-based power change rate limiting method for a research reactor. The proposed controller has been designed for a nonlinear model of the reactor. Compared to the conventional control methods, the proposed scheme shows better control performance as it provides effective compensation for the steady-state error, due to a specific type of unmodeled dynamics. To cope with system uncertainties such as parameter uncertainties, unmodeled dynamics, and even external disturbance, we propose a robust disturbance observer-based feedback linearization controller. Moreover, the fuzzy-based power change rate limiting method is proposed, which is practically required for safe operation to limit the power change rate within a pre-designed safety range. In addition, a motor control input is considered and obtained by using the inverse model for the power control system. We show by numerical simulation that the proposed control law guarantees asymptotic stability as well as improved performance even in the presence of disturbance.

  17. Playtherapy Gives Evidence of Curative Power of Mother-Child Holding as Treatment for Autistic and Emotionally Disturbed Children.

    ERIC Educational Resources Information Center

    Stades-Veth, Jo

    The paper offers a play therapist's evidence for the curative power of intensive mother-child holding of children with emotional problems resulting from separation from the parent and emotional disturbances including autism. Dramatic improvements were observed in the play behaviors of autistic children after enforced cuddling--and these were…

  18. Effect of Power Ultrasound on Food Quality

    NASA Astrophysics Data System (ADS)

    Lee, Hyoungill; Feng, Hao

    Recent food processing technology innovations have been centered around producing foods with fresh-like attributes through minimal processing or nonthermal processing technologies. Instead of using thermal energy to secure food safety that is often accompanied by quality degradation in processed foods, the newly developed processing modalities utilize other types of physical energy such as high pressure, pulsed electric field or magnetic field, ultraviolet light, or acoustic energy to process foods. An improvement in food quality by the new processing methods has been widely reported. In comparison with its low-energy (high-frequency) counterpart which finds applications in food quality inspection, the use of high-intensity ultrasound, also called power ultrasound, in food processing is a relatively new endeavor. To understand the effect of high-intensity ultrasound treatment on food quality, it is important to understand the interactions between acoustic energy and food ingredients, which is covered in Chapter 10. In this chapter, the focus will be on changes in overall food quality attributes that are caused by ultrasound, such as texture, color, flavor, and nutrients.

  19. Effects of historic forest disturbance on water quality and flow in the Interior Western U.S

    Treesearch

    M. Matyjasik; G. Moisen; C. Combe; T. Hathcock; S. Mitts; M. Hernandez; T. Frescino; T. Schroeder

    2014-01-01

    Water quality and flow is affected my many complex factors in the Interior Western U.S. While many studies focus on individual water parameters response to a limited number of changing conditions, little work looks at long term effects of diverse forest disturbances on a broader array of water quality and flow metrics. The U.S. Forest Service Forest Inventory and...

  20. Establishing the Geomagnetic Disturbance Benchmark Event for Evaluation of the Space Weather Hazard on Power Grids

    NASA Astrophysics Data System (ADS)

    Pulkkinen, A. A.; Bernabeu, E.; Eichner, J.

    2014-12-01

    The awareness about potential major impact geomagnetically induced currents (GIC) can have on the North American high-voltage power transmission system has prompted Federal Energy Regulatory Commission (FERC) to launch a geomagnetic disturbances (GMD) standards drafting process. The goals of the GMD standards are to quantify and mitigate the GMD hazard on the North American grid. North American Electric Reliability Corporation's (NERC) is coordinating the standards drafting process that is now entering Phase II involving quantification of the impact GIC can have on individual parts of the North American grid. As a part of the Phase II GMD standards drafting process, substantial effort has been made for generating benchmark GMD scenarios. These scenarios that quantify extreme geoelectric field magnitudes and temporal waveforms of the field fluctuations are the foundation for subsequent engineering and impacts analyses. The engineering analyses will include the transmission system voltage stability and transformer heating assessments. The work on the GMD scenarios has been a major collaboration between a number of international entities involved in GMD research and transmission system operations. We will discuss in this paper the key elements of the benchmark GMD generation process and show the latest results from our work on the topic.

  1. Sleep disturbances and quality of life in patients after living donor liver transplantation.

    PubMed

    Akahoshi, M; Ichikawa, T; Taura, N; Miyaaki, H; Yamaguchi, T; Yoshimura, E; Takahara, I; Soyama, A; Takatsuki, M; Kondo, H; Eguchi, S; Nakao, K

    2014-12-01

    Following improvements in patient and graft survival after liver transplantation (LT), the recipients' quality of life has become an important focus of patient care. Sleep is closely related to physical and mental health; however, sleep disturbances in LT patients have not yet been evaluated. We assessed 59 LT patients (aged ≥18 years) between September 2011 and September 2012. The patients completed the restless legs syndrome (RLS), 36-item short-form health survey (SF-36), Pittsburgh Sleep Quality Index (PSQI), and Epworth Sleepiness Scale (ESS) questionnaires. In addition, laboratory data were obtained and neuropsychological tests (NPT) were performed during study entry. Thirty-eight patients (64%) were included in the poor sleep group (PSQI ≥6 or ESS ≥10). The SF-36 scores were lower in the poor sleep group than in the good sleep group. Eleven patients (18%) had RLS. An NPT score ≥3 indicated minimal hepatic encephalopathy (MHE3). The MHE3 group consisted of 22 patients (43%). The time after LT was shorter; serum albumin, branched chain amino acid/tyrosine molar ratio (BTR), and role limitations due to poor physical health were lower; and serum ammonia levels were higher in the MHE3 group than in the MHE0-2 group. When the poor sleep group was divided into subgroups (control, MHE, RLS, and unknown), MHE patients had high model for end-stage liver disease scores, high ammonia levels, and low BTR, whereas RLS patients showed a short time after LT. Sixty-four percent of recipients were classified as poor sleepers. SF-36 scores were lower for poor sleepers than good sleepers. RLS and MHE are major diseases that cause sleep disturbances in patients after LT. Copyright © 2014 Elsevier Inc. All rights reserved.

  2. Integration of a fuel cell into the power system using an optimal controller based on disturbance accommodation control theory

    NASA Astrophysics Data System (ADS)

    Paradkar, Aniruddha; Davari, Asad; Feliachi, Ali; Biswas, Tamal

    In this paper, the integration of a fuel cell into the power system is treated as a load frequency control (LFC) problem with the fuel cell acting as a load disturbance source. The integration of a fuel cell into the power system results into a change in real power. But changes in real power affect the system frequency. Thus, the integration will result into a change of frequency of the synchronous machines. Hence, we need to design a control scheme for keeping the system in the steady state. An optimal controller based on the disturbance accommodation control (DAC) theory is proposed for this load frequency control problem. For demonstrating the effectiveness of the proposed controller, we have considered a two-area power system with the fuel cell introduced in area 1. The fuel cell is considered as an external disturbance to each subsystem. A mathematical model is derived for each subsystem and based upon these models controllers are designed for keeping each subsystem stable, which in turn stabilizes the overall system. So, the proposed controller is decentralized in nature. To account for the modeling uncertainties, an observer is designed to estimate each subsystem's own and interfacing variables. The controller uses these estimates to optimize a given performance index and allocate generating unit outputs according to the requirements.

  3. Coping Style and Quality of Life in Elderly Patients with Vision Disturbances

    PubMed Central

    Oles, Maria

    2014-01-01

    Purpose. This study aims at evaluating coping style and quality of life in patients with glaucoma and cataract. Methods. The participants were patients (N = 237, 130F; mean age: M = 67,8; SD = 9,5) with low vision caused by cataract (N = 188) and glaucoma (N = 49) who answered the Quality of Life Questionnaire (QOLQ) by Schalock and Keith. The participants were divided by means of cluster analysis (k-means) according to coping styles measured by CISS (Endler and Parker) into three groups: (1) high mobilization for coping, (2) task-oriented coping, and (3) low mobilization for coping. Results. In all the group, a general quality of life was moderately lowered; however, in task-oriented group it was relatively high. Moreover, task-oriented group had significantly lower level of anxiety (STAI), hopelessness (HS), and loneliness (UCLA LS-R) and higher level of self-esteem (SES) in comparison to the patients from high mobilization and low mobilization for coping. Conclusions. In an old age, adaptive coping with vision disturbances does not necessarily mean flexibility in combining all coping styles, but rather task-oriented coping and an ability to use social support. Extreme mobilization for coping seems not adaptive similarly like low mobilization for coping because it violates balance between environmental requirements and personal resources. PMID:25215225

  4. The impact of transfers on water quality and the disturbance regime in a reservoir.

    PubMed

    Fornarelli, Roberta; Antenucci, Jason P

    2011-11-15

    The effect of water transfers between two reservoirs on the water quality of the receiving reservoir was investigated over a 9-year period (2000-2008). Different management strategies were implemented in term of the magnitude and timing of water transfers, i.e. the amount of transferred volume and the frequency at which transfers occurred. These different operational modes were analysed to determine changes in nutrient and metal concentrations, chlorophyll a, algal genera and biovolume. During high water transfers, chlorophyll a and total algal biovolume increased, with larger diatoms preferentially selected due to the high silica content of the pumped inflow and a significant shift in cyanobacteria genera occurring from Microcystis to nitrogen-fixing genera. The magnitude and timing of water transfers exerted a strong control on phytoplankton competition and disturbed the typical seasonal succession during low pumping years of a spring diatom bloom followed by summer cyanobacteria dominance: intensive and frequent water transfers resulted in dominance by diatoms for the whole year and effectively limited cyanobacteria summer growth. From this analysis, we identified iron concentration and diatom biovolume as the key water quality indicators to be included in any optimal management, able to control the transfer regime from both a water quantity and water quality prospective. Copyright © 2011 Elsevier Ltd. All rights reserved.

  5. Detection and Classification of Power Quality Disturbancewaveform Using MRA Based Modified Wavelet Transfrom and Neural Networks

    NASA Astrophysics Data System (ADS)

    Chandrasekar, Perumal; Kamaraj, Vijayarajan

    2010-07-01

    In this paper, the modified wavelet based artificial neural network (ANN) is implemented and tested for power signal disturbances. The power signal is decomposed by using modified wavelet transform and the classification is carried by using ANN. Discrete modified wavelet transforms based signal decomposition technique is integrated with the back propagation artificial neural network model is proposed. Varieties of power quality events including voltage sag, swell, momentary interruption, harmonics, transient oscillation and voltage fluctuation are used to test the performance of the proposed approach. The simulation is carried out by using MATLAB software. The simulation results show that the proposed scheme offers superior detection and classification compared to the conventional approaches.

  6. Disturbance of visual functions as a result of temporary blinding from low power lasers

    NASA Astrophysics Data System (ADS)

    Reidenbach, Hans-Dieter

    2010-04-01

    exposure durations texp from 0.25 s up to 10 s was found. The inability to read due to the disturbance produced by afterimages lasts for about 20 s even if the exposure is not more than 0.25 s from a laser with about 0.8 mW optical output power. In addition to the physiological effects of temporary blinding the psychological glare was determined as a function of the angle between line of sight and beam direction. It was found that already at output powers below 30 μW of a He-Nelaser the subjects reported intense glare effects and felt uncomfortable due to the high brightness. Instead of the standard visual acuity measurement used by eye care professionals, a reading test on a computer monitor was applied after laser irradiation. In this case two different lasers were used as a dazzling light source, one with a wavelength of 632.8 nm and the other with 532 nm. The maximum applied optical power in a 7-mm aperture, which is equivalent to the pupil diameter of a dark adapted eye, was 0.783 mW. The exposure durations were chosen as 0.25 s, 0.5 s, 1 s, 5 s, and 20 s.

  7. High power, high beam quality regenerative amplifier

    DOEpatents

    Hackel, L.A.; Dane, C.B.

    1993-08-24

    A regenerative laser amplifier system generates high peak power and high energy per pulse output beams enabling generation of X-rays used in X-ray lithography for manufacturing integrated circuits. The laser amplifier includes a ring shaped optical path with a limited number of components including a polarizer, a passive 90 degree phase rotator, a plurality of mirrors, a relay telescope, and a gain medium, the components being placed close to the image plane of the relay telescope to reduce diffraction or phase perturbations in order to limit high peak intensity spiking. In the ring, the beam makes two passes through the gain medium for each transit of the optical path to increase the amplifier gain to loss ratio. A beam input into the ring makes two passes around the ring, is diverted into an SBS phase conjugator and proceeds out of the SBS phase conjugator back through the ring in an equal but opposite direction for two passes, further reducing phase perturbations. A master oscillator inputs the beam through an isolation cell (Faraday or Pockels) which transmits the beam into the ring without polarization rotation. The isolation cell rotates polarization only in beams proceeding out of the ring to direct the beams out of the amplifier. The diffraction limited quality of the input beam is preserved in the amplifier so that a high power output beam having nearly the same diffraction limited quality is produced.

  8. High power, high beam quality regenerative amplifier

    DOEpatents

    Hackel, Lloyd A.; Dane, Clifford B.

    1993-01-01

    A regenerative laser amplifier system generates high peak power and high energy per pulse output beams enabling generation of X-rays used in X-ray lithography for manufacturing integrated circuits. The laser amplifier includes a ring shaped optical path with a limited number of components including a polarizer, a passive 90 degree phase rotator, a plurality of mirrors, a relay telescope, and a gain medium, the components being placed close to the image plane of the relay telescope to reduce diffraction or phase perturbations in order to limit high peak intensity spiking. In the ring, the beam makes two passes through the gain medium for each transit of the optical path to increase the amplifier gain to loss ratio. A beam input into the ring makes two passes around the ring, is diverted into an SBS phase conjugator and proceeds out of the SBS phase conjugator back through the ring in an equal but opposite direction for two passes, further reducing phase perturbations. A master oscillator inputs the beam through an isolation cell (Faraday or Pockels) which transmits the beam into the ring without polarization rotation. The isolation cell rotates polarization only in beams proceeding out of the ring to direct the beams out of the amplifier. The diffraction limited quality of the input beam is preserved in the amplifier so that a high power output beam having nearly the same diffraction limited quality is produced.

  9. Aquatic Macrophyte Approach to Assess the Impact of Disturbances on the Diversity of the Ecosystem and on River Quality

    NASA Astrophysics Data System (ADS)

    Thiébaut, Gabrielle

    2006-10-01

    Disturbance has long been recognized as an important determinant of community characteristics in aquatic systems. The aims of our study were to evaluate the impact of different disturbances on the macrophyte diversity and on river quality. To this end, we investigated the floristic composition for different stretches impacted by disturbances and we tested both diversity indices and the trophic index (IBMR) Biological Index Macrophytes in Rivers in the Moselle river (NE of France). The river was divided into four sections of different lengths based on uniformity of morphological characteristics, substrate conditions and flowing velocity: the upper, the wild, the resectioned and the downstream Moselle. Floristic composition and water chemical parameters were analysed from 1999 to 2001. The man-made increase of nutrient concentration favoured the floristic richness in the last sites of the upper Moselle, whereas river dynamics and floods did not allow the development of vegetation in the wild Moselle. Disturbances caused by industrial sewage and eutrophication allowed the spreading of pollu-tolerant and riparian alien species. The aquatic macrophyte approach is a useful means to detect impact of disturbances on diversity and on river quality. However, it was not effective in assessing disturbances such as flood overflow or chemical pollution.

  10. Climatic Events and Historical Disturbances Control Acute and Chronic Water-Quality Impairment After Wildfire

    NASA Astrophysics Data System (ADS)

    Murphy, S. F.; Martin, D. A.; McCleskey, R. B.; Writer, J. H.

    2016-12-01

    Many studies have shown that surface water quality can be impaired after wildfire. The majority of these studies are typically conducted for short periods (1-2 years), and until recently, usually employed routine (fixed-interval) sampling. We monitored stream water quality for five years after a wildfire in the Colorado Front Range using a combination of routine sampling, storm sampling, and continuous sensors. This five-year study facilitated the measurement of post-wildfire water-quality response to a number of climatic events, including low- to moderate-intensity rain storms, drought, extreme rainfall (based on amount of rain that fell in a 7-day period), and the highest spring runoff recorded from the watershed during 23 years of record. Post-wildfire water quality was controlled by the hydrologic response to these climatic events, and by a legacy of historical disturbance from mining and related activities. Increased surface runoff during rain storms led to mobilization of sediment from hillslopes to stream channels. The sediment remained in stream channels during a drought that led to reduced (25% of mean) spring runoff, but this sediment, and associated constituents such as dissolved organic carbon and manganese, were remobilized into the water column and transported downstream during sustained high-flow spring runoff in the third year. We infer that the relative proportions of surface and subsurface runoff were altered by the wildfire and during the extreme rainfall, possibly leading to greater flow through abandoned mine adits and tunnels, and thus causing increased instream metal concentrations (such as arsenic and manganese). Post-wildfire water-quality issues were both acute, with significant water-quality impairment during storm events, and chronic, with elevated concentrations of sediment, nitrate, dissolved organic carbon, manganese, and arsenic for months to years after the wildfire. Such variable source water quality, in both contaminant type and

  11. Direct Adaptive Rejection of Vortex-Induced Disturbances for a Powered SPAR Platform

    NASA Technical Reports Server (NTRS)

    VanZwieten, Tannen S.; Balas, Mark J.; VanZwieten, James H.; Driscoll, Frederick R.

    2009-01-01

    The Rapidly Deployable Stable Platform (RDSP) is a novel vessel designed to be a reconfigurable, stable at-sea platform. It consists of a detachable catamaran and spar, performing missions with the spar extending vertically below the catamaran and hoisting it completely out of the water. Multiple thrusters located along the spar allow it to be actively controlled in this configuration. A controller is presented in this work that uses an adaptive feedback algorithm in conjunction with Direct Adaptive Disturbance Rejection (DADR) to mitigate persistent, vortex-induced disturbances. Given the frequency of a disturbance, the nominal DADR scheme adaptively compensates for its unknown amplitude and phase. This algorithm is extended to adapt to a disturbance frequency that is only coarsely known by including a Phase Locked Loop (PLL). The PLL improves the frequency estimate on-line, allowing the modified controller to reduce vortex-induced motions by more than 95% using achievable thrust inputs.

  12. Corrective Measures for the Effective Load Management and Control Under Disturbance at Bhusawal Thermal Power Station: Case Study

    NASA Astrophysics Data System (ADS)

    Ballal, Makarand Sudhakar; Ballal, Deepali Makarand; Suryawanshi, Hiralal Murlidhar; Mishra, Mahesh Kumar

    2014-04-01

    A modern power grid needs to become smarter in order to provide an affordable, reliable, and sustainable supply of electricity. The objective of this work is to investigate the discrepancies in power flow control under the abnormal circumstances and to maintain grid stability. This paper reports investigation into the factors that influence the dynamic behavior of the power control from Bhusawal Thermal Power Station (BTPS), India. The problems of existing power system are discussed by considering the case studies of BTPS substation and very efficient solutions are proposed to resolves these hurdles. Load flow studies are carried out for different cases, considering realistic load condition before and after disturbances. Simulation is performed in MATLAB environment and recorded parameters are compared with simulation results.

  13. HOS network-based classification of power quality events via regression algorithms

    NASA Astrophysics Data System (ADS)

    Palomares Salas, José Carlos; González de la Rosa, Juan José; Sierra Fernández, José María; Pérez, Agustín Agüera

    2015-12-01

    This work compares seven regression algorithms implemented in artificial neural networks (ANNs) supported by 14 power-quality features, which are based in higher-order statistics. Combining time and frequency domain estimators to deal with non-stationary measurement sequences, the final goal of the system is the implementation in the future smart grid to guarantee compatibility between all equipment connected. The principal results are based in spectral kurtosis measurements, which easily adapt to the impulsive nature of the power quality events. These results verify that the proposed technique is capable of offering interesting results for power quality (PQ) disturbance classification. The best results are obtained using radial basis networks, generalized regression, and multilayer perceptron, mainly due to the non-linear nature of data.

  14. Program Inventory. National Needs Analysis Project: Fostering Quality Program Planning and Design in the Area of Serious Emotional Disturbance.

    ERIC Educational Resources Information Center

    Grosenick, J. K.; And Others

    The document consists of a 125-item evaluation instrument for use in assessing the overall plan and quality of programs in the area of serious emotional disturbance (SED) or behavior disorders. Questions are organized according to the following nine categories (based on identified components of a well-designed SED program): (1) respondent and…

  15. Sleep–wake disturbances in cancer patients: narrative review of literature focusing on improving quality of life outcomes

    PubMed Central

    Dickerson, Suzanne S; Connors, Laurie M; Fayad, Ameera; Dean, Grace E

    2014-01-01

    Purpose Evidence suggests a high prevalence of sleep–wake disturbances in patients with cancer, occurring at diagnosis, during treatment, and continuing to survivorship. Yet associations between sleep–wake disturbances and the impact on quality of life outcomes is less clear. The purpose of this narrative review of the literature is to evaluate sleep–wake disturbances in patients with cancer, to describe the influence of poor sleep on quality of life as an outcome, and to evaluate the evidence to recommend future interventions. Framework and methods This review was guided by the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) approach. Four databases (CINAHL, MEDLINE, PsycINFO, and Embase) were searched using terms “cancer OR neoplasm”, “sleep, sleep disturbance, sleep disorders or insomnia”, and “quality of life”; the search included all years, English language, and peer-reviewed articles on research studies. Studies included measurements of sleep and quality of life in cancer patients at a minimum of two time points and demonstrated relationships between sleep and quality of life. Data were collected on date, patient demographics, cancer type and treatment, timeframe, design, measurement, variables, and results. Results This narrative review demonstrates that sleep–wake disturbance is a major problem/symptom in patients with cancer. Of the 18 studies included, measurement of sleep-related variables included objective and subjective measures; however, direct measurement of the associations between sleep and quality of life was not common. Cognitive behavioral therapy for insomnia and mind–body interventions demonstrated feasibility when implemented into cancer care settings. In addition, the majority of interventions exhibited moderate effectiveness in improving sleep–wake disturbance and quality of life outcomes. Conclusion The studies predominantly reported that poor sleep negatively impacts quality of life

  16. Intimate Partner Violence Is Associated with Stress-Related Sleep Disturbance and Poor Sleep Quality during Early Pregnancy

    PubMed Central

    Sanchez, Sixto E.; Islam, Suhayla; Zhong, Qiu-Yue; Gelaye, Bizu; Williams, Michelle A.

    2016-01-01

    Objectives To examine the associations of Intimate partner violence (IPV) with stress-related sleep disturbance (measured using the Ford Insomnia Response to Stress Test [FIRST]) and poor sleep quality (measured using the Pittsburgh Sleep Quality Index [PSQI]) during early pregnancy. Methods This cross-sectional study included 634 pregnant Peruvian women. In-person interviews were conducted in early pregnancy to collect information regarding IPV history, and sleep traits. Adjusted odds ratios (aOR) and 95% confidence intervals (95%CIs) were calculated using logistic regression procedures. Results Lifetime IPV was associated with a 1.54-fold increased odds of stress-related sleep disturbance (95% CI: 1.08–2.17) and a 1.93-fold increased odds of poor sleep quality (95% CI: 1.33–2.81). Compared with women experiencing no IPV during lifetime, the aOR (95% CI) for stress-related sleep disturbance associated with each type of IPV were: physical abuse only 1.24 (95% CI: 0.84–1.83), sexual abuse only 3.44 (95%CI: 1.07–11.05), and physical and sexual abuse 2.51 (95% CI: 1.27–4.96). The corresponding aORs (95% CI) for poor sleep quality were: 1.72 (95% CI: 1.13–2.61), 2.82 (95% CI: 0.99–8.03), and 2.50 (95% CI: 1.30–4.81), respectively. Women reporting any IPV in the year prior to pregnancy had increased odds of stress-related sleep disturbance (aOR = 2.07; 95% CI: 1.17–3.67) and poor sleep quality (aOR = 2.27; 95% CI: 1.30–3.97) during pregnancy. Conclusion Lifetime and prevalent IPV exposures are associated with stress-related sleep disturbance and poor sleep quality during pregnancy. Our findings suggest that sleep disturbances may be important mechanisms that underlie the lasting adverse effects of IPV on maternal and perinatal health. PMID:27023005

  17. Intimate Partner Violence Is Associated with Stress-Related Sleep Disturbance and Poor Sleep Quality during Early Pregnancy.

    PubMed

    Sanchez, Sixto E; Islam, Suhayla; Zhong, Qiu-Yue; Gelaye, Bizu; Williams, Michelle A

    2016-01-01

    To examine the associations of Intimate partner violence (IPV) with stress-related sleep disturbance (measured using the Ford Insomnia Response to Stress Test [FIRST]) and poor sleep quality (measured using the Pittsburgh Sleep Quality Index [PSQI]) during early pregnancy. This cross-sectional study included 634 pregnant Peruvian women. In-person interviews were conducted in early pregnancy to collect information regarding IPV history, and sleep traits. Adjusted odds ratios (aOR) and 95% confidence intervals (95%CIs) were calculated using logistic regression procedures. Lifetime IPV was associated with a 1.54-fold increased odds of stress-related sleep disturbance (95% CI: 1.08-2.17) and a 1.93-fold increased odds of poor sleep quality (95% CI: 1.33-2.81). Compared with women experiencing no IPV during lifetime, the aOR (95% CI) for stress-related sleep disturbance associated with each type of IPV were: physical abuse only 1.24 (95% CI: 0.84-1.83), sexual abuse only 3.44 (95%CI: 1.07-11.05), and physical and sexual abuse 2.51 (95% CI: 1.27-4.96). The corresponding aORs (95% CI) for poor sleep quality were: 1.72 (95% CI: 1.13-2.61), 2.82 (95% CI: 0.99-8.03), and 2.50 (95% CI: 1.30-4.81), respectively. Women reporting any IPV in the year prior to pregnancy had increased odds of stress-related sleep disturbance (aOR = 2.07; 95% CI: 1.17-3.67) and poor sleep quality (aOR = 2.27; 95% CI: 1.30-3.97) during pregnancy. Lifetime and prevalent IPV exposures are associated with stress-related sleep disturbance and poor sleep quality during pregnancy. Our findings suggest that sleep disturbances may be important mechanisms that underlie the lasting adverse effects of IPV on maternal and perinatal health.

  18. A Power Analysis and Recommended Study Design to Directly Detect Population Level Consequences of Acoustic Disturbance

    DTIC Science & Technology

    2015-09-30

    quantify potential human impacts on the health of beaked whale populations ?” (i.e, what is a recommended study design for doing this?). Quantifying...effectiveness of Navy funds for monitoring population health of beaked whales and human impacts thereon. RELATED PROJECTS Moretti, David...Detect Population -Level Consequences of Acoustic Disturbance Jeffrey Moore NOAA Southwest Fisheries Science Center 8901 La Jolla Shores Drive

  19. Power quality enhancement of renewable energy source power network using SMES system

    NASA Astrophysics Data System (ADS)

    Seo, H. R.; Kim, A. R.; Park, M.; Yu, I. K.

    2011-11-01

    This paper deals with power quality enhancement of renewable energy source power network using SMES system and describes the operation characteristics of HTS SMES system using real-toroidal-type SMES coil for smoothening the fluctuation of large-scale renewable energy source such as photovoltaic (PV) power generation system. It generates maximum power of PV array under various weather conditions. SMES unit charges and discharges the HTS coil to mitigate the fluctuation of PV system output power. The SMES unit is controlled according to the PV array output and the utility power quality conditions. The grid connected PV and SMES system has been modeled and simulated using power-hard-in-the-loop simulation (PHILS). The PHILS results demonstrated the effectiveness of the SMES system for enhancing power quality in power network including large-scale renewable energy source, especially PV power generation system.

  20. Power quality improvement by unified power quality conditioner based on CSC topology using synchronous reference frame theory.

    PubMed

    Dharmalingam, Rajasekaran; Dash, Subhransu Sekhar; Senthilnathan, Karthikrajan; Mayilvaganan, Arun Bhaskar; Chinnamuthu, Subramani

    2014-01-01

    This paper deals with the performance of unified power quality conditioner (UPQC) based on current source converter (CSC) topology. UPQC is used to mitigate the power quality problems like harmonics and sag. The shunt and series active filter performs the simultaneous elimination of current and voltage problems. The power fed is linked through common DC link and maintains constant real power exchange. The DC link is connected through the reactor. The real power supply is given by the photovoltaic system for the compensation of power quality problems. The reference current and voltage generation for shunt and series converter is based on phase locked loop and synchronous reference frame theory. The proposed UPQC-CSC design has superior performance for mitigating the power quality problems.

  1. Power Quality Improvement by Unified Power Quality Conditioner Based on CSC Topology Using Synchronous Reference Frame Theory

    PubMed Central

    Dharmalingam, Rajasekaran; Dash, Subhransu Sekhar; Senthilnathan, Karthikrajan; Mayilvaganan, Arun Bhaskar; Chinnamuthu, Subramani

    2014-01-01

    This paper deals with the performance of unified power quality conditioner (UPQC) based on current source converter (CSC) topology. UPQC is used to mitigate the power quality problems like harmonics and sag. The shunt and series active filter performs the simultaneous elimination of current and voltage problems. The power fed is linked through common DC link and maintains constant real power exchange. The DC link is connected through the reactor. The real power supply is given by the photovoltaic system for the compensation of power quality problems. The reference current and voltage generation for shunt and series converter is based on phase locked loop and synchronous reference frame theory. The proposed UPQC-CSC design has superior performance for mitigating the power quality problems. PMID:25013854

  2. The impact of nocturnal disturbances on daily quality of life in patients with Parkinson’s disease

    PubMed Central

    Yu, Rwei-Ling; Tan, Chun-Hsiang; Wu, Ruey-Meei

    2015-01-01

    Objectives The aims of this study were to explore nocturnal disturbances in patients with Parkinson’s disease (PD) and to assess their impact on quality of life (QoL). Methods A total of 211 patients with PD were recruited for this study, and each participant was evaluated using the mini-mental state examination, PD sleep scale – second version (PDSS-2), pittsburgh sleep quality index (PSQI), PD QoL questionnaire (PDQ), Epworth sleepiness scale, Hoehn and Yahr (H&Y) staging, and unified Parkinson’s disease rating scale (UPDRS). Multiple regression analyses were performed to determine the contribution of the predictive variables on QoL. Results There were 56.4% males (mean age: 64.08 years; disease duration: 6.02 years; H&Y stage: 2.25; and UPDRS: 33.01) in this study. Our patients’ actual sleep time was 5.96±1.16 hours and the average sleep efficiency was 82.93%±12.79%. Up to 64.4% of patients were classified as “poor” sleepers and 23.8% suffered from daytime sleepiness. The final stepwise regression model revealed that UPDRS parts I and II, the sleep disturbance and daytime dysfunction components of the PSQI, the PD symptoms at night subscale of the PDSS-2, and the levodopa equivalent dose were significant predictors of the PDQ score (R2=53, F7,165=28.746; P<0.001). Conclusion Most of the PD patients have sleep problems, and nearly one-quarter of them have abnormal daytime somnolence. The nocturnal disturbances were found to result in worse QoL in PD patients. Ethnicity-specific effects of susceptibility to sleep disturbances were discussed, and these results also highlighted the direction for further studies to explore when examining effective management programs toward these disturbances. PMID:26273203

  3. The relationship between subjective sleep disturbance, sleep quality, and emotion regulation difficulties in a sample of college students reporting trauma exposure.

    PubMed

    Pickett, Scott M; Barbaro, Nicole; Mello, David

    2016-01-01

    Sleep disturbance and poor sleep quality has been associated with trauma exposure and posttraumatic stress disorder (PTSD) symptoms; however, the associated emotional consequences of sleep disturbance have not been examined within this context (i.e., emotional reactivity, emotion modulation). The current study examined the relationship between sleep disturbance, poor sleep quality, and emotion regulation difficulties. In a sample of college students reporting exposure to at least 1 traumatic event, online survey methodology was used to assess PTSD symptom severity (PTSS), sleep disturbances, including PTSD-specific sleep disturbances, and emotion regulation difficulties. After controlling for PTSS, sleep disturbance and poor sleep quality domains were related to both global and specific difficulties in emotion regulation domains. The findings suggest that sleep disturbance and emotion regulation difficulties associated with PTSD may not be a mere extension of the clinical picture of PTSD. Sleep disturbances following trauma exposure may contribute to emotion regulation difficulties and exacerbate negative consequences. Future research should examine the effects of treatments that simultaneously address sleep disturbances and PTSD symptoms on emotion regulation processes.

  4. Sleep Quality and Body Mass Index in College Students: The Role of Sleep Disturbances

    ERIC Educational Resources Information Center

    Vargas, Perla A.; Flores, Melissa; Robles, Elias

    2014-01-01

    Objective: Obesity and its comorbidities have emerged as a leading public health concern. The aim of this study was to explore the relationship between body mass index (BMI) and sleep patterns, including duration and disturbances. Methods: A convenience sample of 515 college students completed an online survey consisting of the Pittsburgh Sleep…

  5. Sleep Quality and Body Mass Index in College Students: The Role of Sleep Disturbances

    ERIC Educational Resources Information Center

    Vargas, Perla A.; Flores, Melissa; Robles, Elias

    2014-01-01

    Objective: Obesity and its comorbidities have emerged as a leading public health concern. The aim of this study was to explore the relationship between body mass index (BMI) and sleep patterns, including duration and disturbances. Methods: A convenience sample of 515 college students completed an online survey consisting of the Pittsburgh Sleep…

  6. Standby-battery autonomy versus power quality

    NASA Astrophysics Data System (ADS)

    Bitterlin, Ian F.

    Batteries are used in a wide variety of applications as an energy store to bridge gaps in the primary source of supplied power for a given period of time. In some cases this bridging time, the battery's "autonomy", is fixed by local legislation but it is also often set by historically common practices. However, even if common practice dictates a long autonomy time, we are entering a new era of "cost and benefit realism" underpinned by environmentally friendly policies and we should challenge these historical practices at every opportunity if it can lead to resource and cost savings. In some cases the application engineer has no choice in the design autonomy; either follow a piece of local legislation (e.g. 4 h autonomy for a "life safety" application), or actually work out what is needed! An example of the latter would be for a remote site, off-grid, using integrated wind/solar power (without emergency generator back-up) where you may have to design-in several days' battery autonomy. This short paper proposes that a battery's autonomy should be related to the time expected for the system to be without the primary power source, balanced by the capital costs and commercial risk of power failure. To discuss this we shall consider the factors in selecting the autonomy time and other related aspects for high voltage battery systems used in facility-wide uninterruptible power supply (UPS) systems.

  7. Research on modeling and conduction disturbance simulation of secondary power system in a device

    NASA Astrophysics Data System (ADS)

    Ding, Xu; Yu, Zhi-Yong; Jin, Rui

    2017-06-01

    To find electromagnetic interference (EMI) and other problems in the secondary power supply system design quickly and effectively, simulations are carried out under the Saber simulation software platform. The DC/DC converter model with complete performance and electromagnetic characteristics is established by combining parametric modeling with Mast language. By using the method of macro modeling, the hall current sensor and power supply filter model are established respectively based on the function, schematic diagram of the components. Also the simulation of the component model and the whole secondary power supply system are carried out. The simulation results show that the proposed model satisfies the functional requirements of the system and has high accuracy. At the same time, due to the ripple characteristics in the DC/DC converter modeling, it can be used as a conducted interference model to simulate the power bus conducted emission CE102 project under the condition that the simulated load is full, which provides a useful reference for the electromagnetic interference suppression of the system.

  8. Second-order small-disturbance solutions for hypersonic flow over power-law bodies

    NASA Technical Reports Server (NTRS)

    Townsend, J. C.

    1975-01-01

    Similarity solutions were found which give the adiabatic flow of an ideal gas about two-dimensional and axisymmetric power-law bodies at infinite Mach number to second order in the body slenderness parameter. The flow variables were expressed as a sum of zero-order and perturbation similarity functions for which the axial variations in the flow equations separated out. The resulting similarity equations were integrated numerically. The solutions, which are universal functions, are presented in graphic and tabular form. To avoid a singularity in the calculations, the results are limited to body power-law exponents greater than about 0.85 for the two-dimensional case and 0.75 for the axisymmetric case. Because of the entropy layer induced by the nose bluntness (for power-law bodies other than cones and wedges), only the pressure function is valid at the body surface. The similarity results give excellent agreement with the exact solutions for inviscid flow over wedges and cones having half-angles up to about 20 deg. They give good agreement with experimental shock-wave shapes and surface-pressure distributions for 3/4-power axisymmetric bodies, considering that Mach number and boundary-layer displacement effects are not included in the theory.

  9. Use of Interplanetary Radio Scintillation Power Spectra in Predicting Geomagnetic Disturbances.

    DTIC Science & Technology

    1977-10-31

    COCOA -Cross array at 34.3 MHz located at Clark Lake Radio Observatory near Borrego Springs, California and synoptic data on 33 sources were reduced to...yield scintillation index (band-pass integrated IPS power) for each source. In 1976, COCOA -Cross observations at 34.3 MHz were supplemented by 38 MHz

  10. Power System Harmonic Elimination to Improve Power Quality

    NASA Astrophysics Data System (ADS)

    Chandrasekaran, K.; Ramachandaramurthy, V. K.

    2015-06-01

    An improvised RLC interface filter for a Dynamic Voltage Restorer (DVR) is proposed. The RLC filter is connected in the front end between the IGBT based Voltage Source Inverter (VSI) and the injection transformer and is able to eliminate voltage harmonics in the system and also switching harmonics generated from VSI. The voltage at the sensitive load end is pure sinusoidal. In this method, the DVR produced Pulse Width Modulation (PWM) voltage with voltage harmonic canceling the voltage harmonic generated from the supply main. The VSI handles harmonic power. The low order switching harmonics generated by the IGBT based VSI is suppressed. The DVR has greater voltage injection capability. Good dynamic and transient results recorded and Total Harmonic Distortion (THD) at the sensitive load end is minimized. The voltage at the sensitive load is sinusoidal and at 1.0 pu. PSCAD/EMTDC is used to validate the performance of the interface filter and the DVR. Simulated results are presented.

  11. Effects of Village Power Quality on Fuel Consumption and Operating Expenses

    SciTech Connect

    Richard Wies; Ron Johnson

    2008-12-31

    Alaska's rural village electric utilities are isolated from the Alaska railbelt electrical grid intertie and from each other. Different strategies have been developed for providing power to meet demand in each of these rural communities. Many of these communities rely on diesel electric generators (DEGs) for power. Some villages have also installed renewable power sources and automated generation systems for controlling the DEGs and other sources of power. For example, Lime Village has installed a diesel battery photovoltaic hybrid system, Kotzebue and Wales have wind-diesel hybrid systems, and McGrath has installed a highly automated system for controlling diesel generators. Poor power quality and diesel engine efficiency in village power systems increases the cost of meeting the load. Power quality problems may consist of poor power factor (PF) or waveform disturbances, while diesel engine efficiency depends primarily on loading, the fuel type, the engine temperature, and the use of waste heat for nearby buildings. These costs take the form of increased fuel use, increased generator maintenance, and decreased reliability. With the cost of bulk fuel in some villages approaching $1.32/liter ($5.00/gallon) a modest 5% decrease in fuel use can result in substantial savings with short payback periods depending on the village's load profile and the cost of corrective measures. This project over its five year history has investigated approaches to improving power quality and implementing fuel savings measures through the use of performance assessment software tools developed in MATLAB{reg_sign} Simulink{reg_sign} and the implementation of remote monitoring, automated generation control, and the addition of renewable energy sources in select villages. The results have shown how many of these communities would benefit from the use of automated generation control by implementing a simple economic dispatch scheme and the integration of renewable energy sources such as wind

  12. Effects of electronic equipment on plant power quality

    SciTech Connect

    Heydt, G.T. . Dept. of Electrical Engineering); Spindler, J. )

    1992-09-17

    This paper reports on improved product quality and increased productivity which are companion goals of all manufacturing industries, and these objectives are increasingly being met by the extensive use of electronic equipment in industrial plants. Today's electronic equipment, however, introduces another component into the manufacturing quality equation - the element of electric power quality. Longevity and healthy, glitch-free operation of solid-state electronic equipment requires a diet of clean electric power. Among the power supply anomalies that can cause misoperation or failure of electronic equipment are undervoltage, overvoltage, voltage transient surges or sags, frequency instability, momentary power outages, electrical noise, and harmonics. Harmonics are multiples of the fundamental (60 Hz) power system frequency superimposed on the fundamental - with the net result being distortion of the fundamental waveform. Harmonics are identified by their harmonic order - the 6th harmonic, for example, superimposes a 300 Hz frequency on the 60 Hz fundamental.

  13. Prevalence of Sleep Disturbances and Their Associations With Demographic and Clinical Characteristics and Quality of Life in Older Adults in Macao.

    PubMed

    Nogueira, Bernice O C Lam; Li, Lu; Meng, Li-Rong; Ungvari, Gabor S; Forester, Brent P; Chiu, Helen F K; Kuok, Kenny C F; Tran, Linda; Liu, Zhao-Min; Xiang, Yu-Tao

    2016-12-14

    To examine the prevalence of sleep disturbances (difficulty initiating sleep [DIS], difficulty maintaining sleep [DMS], and early morning awakening [EMA]), their socio-demographic and clinical correlates, and quality of life (QOL) in older adults in Macao. Four hundred fifty-one subjects were interviewed using standardized instruments. The prevalence of at least one type of sleep disturbance was 38.1%; the figures of DIS, DMS, and EMA were 18.6, 31.3, and 23.9%, respectively. Female sex and depressive symptoms were independently associated with more frequent sleep disturbances. Sleep disturbances were independently associated with lower physical QOL. Sleep disturbances are common in older adults in Macao. Appropriate strategies should be implemented to prevent and treat sleep disturbances and concerted attempts should be made to improve access to treatment. © 2016 Wiley Periodicals, Inc.

  14. Subjective Perception of Sleep, but not its Objective Quality, is Associated with Immediate Postpartum Mood Disturbances in Healthy Women

    PubMed Central

    Bei, Bei; Milgrom, Jeannette; Ericksen, Jennifer; Trinder, John

    2010-01-01

    Study Objectives: This study investigated whether there was a relationship between disrupted sleep and postpartum mood disturbances in women during the week after delivery. Design: Sleep and mood were measured during the third trimester (Time-1) and one week postpartum (Time-2) in a 2-stage longitudinal design. Setting: Participants were recruited from an antenatal clinic in a regional Melbourne hospital. Participants: Forty-four healthy women at low risk for postpartum depression. Interventions: N/A Measurements and Results: Objective sleep was measured by actigraphy and subjective sleep by the Pittsburgh Sleep Quality Index; mood was assessed by the Depression Anxiety Stress Scale, the Hospital Anxiety Depression Scale, and the Positive and Negative Affect Schedule. Sleep and mood questionnaires were administered at Time-1 and Time-2. Wrist actigraphy was collected for one week at both times. After delivery, both objective and subjective nighttime sleep significantly worsened with decreased total sleep time and sleep efficiency, while daytime napping behavior significantly increased. On average, mood improved across all scales after delivery, although 45.95% of the sample experienced deterioration of mood. Regression analyses showed little relationship between Time-1 and Time-2 objective nighttime sleep, and postpartum mood. Variables that related to both Time-1 and Time-2 subjective perception of sleep, including subjective nighttime sleep, sleep-related daytime dysfunction, and daytime napping behavior, were significant predictors of postpartum mood. Conclusions: The perception of poor sleep, and the conscious awareness of its impact during wake-time, might share a stronger relationship with the occurrence of immediate postpartum mood disturbances than actual sleep quality and quantity. Citation: Bei B; Milgrom J; Ericksen J; Trinder J. Subjective perception of sleep, but not its objective quality, is associated with immediate postpartum mood disturbances in

  15. Distributed Energy Resources, Power Quality and Reliability - Background

    SciTech Connect

    Schienbein, Lawrence A.; DeSteese, John G.

    2002-01-31

    Power quality [PQ] and power reliability [PR] gained importance in the industrialized world as the pace of installation of sensitive appliances and other electrical loads by utility customers accelerated, beginning in the mid 1980s. Utility-grid-connected customers rapidly discovered that this equipment was increasingly sensitive to various abnormalities in the electricity supply.

  16. Electrical Power Quality - What's Behind the Outlet?

    NASA Astrophysics Data System (ADS)

    Baird, William H.; Secrest, Jeffery; Padgett, Clifford

    2017-09-01

    Although we may consider the power outlets in our homes to be nearly ideal voltage sources, a variety of influences in and around the home can cause departures from the nominal 60 Hz, 110-120 V root-mean-square (rms) of the North American grid. Even without instrumentation, we can see that a large motor starting from rest can be sufficient to cause lights to dim momentarily (voltage sag). This dimming is due to the inrush current drawn by a stationary motor, which may be several times the current drawn at operating speed. We prepared a voltage monitoring system using a voltage divider, the construction details of which we omit in the interest of safety.

  17. Joint application of AI techniques, PRA and disturbance analysis methodology to problems in the maintenance and design of nuclear power plants

    SciTech Connect

    Okrent, D.

    1989-03-01

    This final report summarizes the accomplishments of a two year research project entitled Joint Application of Artificial Intelligence Techniques, Probabilistic Risk Analysis, and Disturbance Analysis Methodology to Problems in the Maintenance and Design of Nuclear Power Plants. The objective of this project is to develop and apply appropriate combinations of techniques from artificial intelligence, (AI), reliability and risk analysis and disturbance analysis to well-defined programmatic problems of nuclear power plants. Reactor operations issues were added to those of design and maintenance as the project progressed.

  18. Joint application of AI techniques, PRA and disturbance analysis methodology to problems in the maintenance and design of nuclear power plants. Final report

    SciTech Connect

    Okrent, D.

    1989-03-01

    This final report summarizes the accomplishments of a two year research project entitled ``Joint Application of Artificial Intelligence Techniques, Probabilistic Risk Analysis, and Disturbance Analysis Methodology to Problems in the Maintenance and Design of Nuclear Power Plants. The objective of this project is to develop and apply appropriate combinations of techniques from artificial intelligence, (AI), reliability and risk analysis and disturbance analysis to well-defined programmatic problems of nuclear power plants. Reactor operations issues were added to those of design and maintenance as the project progressed.

  19. Experimental observations of the spatial structure of wave-like disturbances generated in midlatitude ionosphere by high power radio waves

    NASA Astrophysics Data System (ADS)

    Kunitsyn, V.; Andreeva, E.; Padokhin, A. M.; Nazarenko, M.; Frolov, V.; Komrakov, G.; Bolotin, I.

    2012-12-01

    We present the results of the experiments carried out in 2009-2012 on the Sura heating facility (Radio Physical Research Institute, N. Novgorod, Russia) on modification of the midlatitude ionosphere by powerful HF radiowaves. The experiments were conducted using O-mode radiowaves at frequencies lower than critical frequency of the ionospheric F2 layer both in daytime and nighttime ionosphere. Various schemes of the radiation of the heating wave were used including square wave modulation of the effective radiated power (ERP) at various frequencies and power stepping. Radio transmissions of the low- (Parus/Tsikada) and high-orbital (GPS/GLONASS) navigational satellites received at the mobile network of receiving sites were used for the remote sensing of the heated area of the ionosphere. The variations in the slant total electron content (TEC), which are proportional to the reduced phase of navigational signals, were studied for the satellite passes for which ionospheric penetration points crossed the disturbed area during HF heating. The variations in TEC caused by HF heating are identified in a number of examples. It is shown that the GNSS TEC spectra contain frequency components corresponding to the modulation periods of the ERP of the heating wave. The manifestations of the heating-induced variations in TEC are most prominent in the area of magnetic zenith of the pumping wave. Different behavior of TEC variations was observed during nighttime and daytime heating experiments. In daytime conditions the pump wave switched ON causes the increase of TEC while in the nighttime it causes a decrease in TEC. This can be explained by the different contribution of the processes responsible for the increase and decrease of TEC in daytime in nighttime conditions. In this work we also present the first time radiotomographic reconstructions of the spatial structure of the wave-like disturbances, generated in the ionosphere by high-power radio waves radiated by the Sura heater

  20. Annual progress report on the development of a 2 MW/10 second battery energy storage system for power disturbance protection

    SciTech Connect

    1996-01-29

    Sandia National Laboratories (SNL), acting for the US Department of Energy (DOE), contracts for and administers programs for the purpose of promoting the development and commercialization of large scale, transportable battery energy storage systems. Under DOE Co-Op Agreement No. DE-FC04-94AL99852, SNL has contracted for the development and delivery of an initial prototype 250 kW bridge that becomes an integral subsystem of a 2 MW/10 Second System that can be used by utility customers to protect power sensitive equipment from power disturbances. Development work includes field installation and testing of the prototype unit at a participating utility site for extended product testing with subsequent relocation to an industrial or commercial participating utility customer site for additional evaluation. The program described by the referenced document calls for cost sharing with the successful bidder and eventual title transfer to the participating utility. Prototype delivery is scheduled for January of 1996, with a period of two years allowed for field testing. A final report summarizing the test data with conclusions and recommendations is part of the contract.

  1. Experimental forest watershed studies contribution to the effect of disturbances on water quality

    Treesearch

    Daniel G. Neary

    2012-01-01

    The most sustainable and best quality fresh water sources in the world originate in forested watersheds (Dissmeyer 2000, Brooks et al. 2003, Barten and Ernst 2004). The biological, chemical, and physical characteristics of forest soils are particularly well suited to delivering high quality water to streams, and moderating the climatic extremes which affect stream...

  2. Sleep disturbances, socioeconomic status, and seizure control as main predictors of quality of life in epilepsy.

    PubMed

    Alanis-Guevara, I; Peña, E; Corona, T; López-Ayala, T; López-Meza, E; López-Gómez, M

    2005-11-01

    Improving quality of life is the most important goal for patients with epilepsy. To recognize the factors associated with quality of life in patients with epilepsy in Mexico, we performed a cross-sectional survey using the Quality of Life in Epilepsy 31 (QOLIE-31) inventory to assess the quality of life of 401 adult patients with epilepsy at the National Institute of Neurology and Neurosurgery of Mexico. Clinical and demographical data were collected. Multiple regression was used to determine which factors affected quality of life in our patients. The variables that most strongly predicted a lower QOLIE-31 total score after multiple regression were sleep disorders (P<0.001), socioeconomic status (P<0.001), female gender (P=0.002), and high seizure frequency (P=0.001). In our study, neither depression nor time of evolution of epilepsy had significant influence on QOLIE-31 scores.

  3. Automated FMV image quality assessment based on power spectrum statistics

    NASA Astrophysics Data System (ADS)

    Kalukin, Andrew

    2015-05-01

    Factors that degrade image quality in video and other sensor collections, such as noise, blurring, and poor resolution, also affect the spatial power spectrum of imagery. Prior research in human vision and image science from the last few decades has shown that the image power spectrum can be useful for assessing the quality of static images. The research in this article explores the possibility of using the image power spectrum to automatically evaluate full-motion video (FMV) imagery frame by frame. This procedure makes it possible to identify anomalous images and scene changes, and to keep track of gradual changes in quality as collection progresses. This article will describe a method to apply power spectral image quality metrics for images subjected to simulated blurring, blocking, and noise. As a preliminary test on videos from multiple sources, image quality measurements for image frames from 185 videos are compared to analyst ratings based on ground sampling distance. The goal of the research is to develop an automated system for tracking image quality during real-time collection, and to assign ratings to video clips for long-term storage, calibrated to standards such as the National Imagery Interpretability Rating System (NIIRS).

  4. [Disturbance in ADL from Chemotherapy-induced Peripheral Neuropathy and Quality of Life in Cancer Patients: The Mediating Effect of Psychological Distress].

    PubMed

    Kim, Kyung Yeon; Lee, Seung Hee; Kim, Jeong Hye; Oh, Pok Ja

    2015-10-01

    The purpose of this study was to examine the mediation of psychological distress in the relationship between disturbance in ADL from chemotherapy induced peripheral neuropathy and quality of life in order to provide a basis for planning nursing interventions to improve the quality of life in cancer patients. A purposive sample of 130 patients treated with chemotherapy were recruited in the cross-sectional survey design. Data were collected using self-report questionnaires. The instruments were the Chemotherapy Induced Peripheral Neuropathy Assessment Tool (CIPNAT), Hospital Anxiety Depression Scale (HADS), and Functional Assessment of Cancer Therapy-General (FACT-G). The mean score for disturbance in ADL from chemotherapy induced peripheral neuropathy was 3.30. Overall quality of life was 2.48. The mean score was 1.04 for psychological distress. The prevalence was 35.4% for anxiety and 47.7% for depression. There were significant correlations among the three variables, disturbance in ADL from chemotherapy induced peripheral neuropathy, psychosocial distress, and quality of life. Psychosocial distress had a complete mediating effect (β=-.74, p<.001) in the relationship between disturbance in ADL from chemotherapy induced peripheral neuropathy and quality of life (Sobel test: Z=-6.11, p<.001). Based on the findings of this study, nursing intervention programs focusing on disturbance of ADL management, and decrease of psychological distress are highly recommended to improve quality of life in cancer patients.

  5. A Power Factor Corrected SMPS with Improved Power Quality for Welding Applications

    NASA Astrophysics Data System (ADS)

    Narula, Swati; Singh, Bhim; Bhuvaneswari, G.; Pandey, Rahul

    2015-04-01

    This paper presents the analysis, design and implementation of a power factor corrected Arc Welding Power Supply (AWPS) with a boost converter at the front end and three full-bridge (FB) converters connected in parallel at the load end. The modular arrangement of the FB converters offers several meritorious features like usage of power devices with comparatively lower voltage and current ratings, ease of power expandability, easy maintenance, etc. The boost converter operates in continuous conduction mode minimizing the input current ripple and leading to the lowest RMS current thereby improving the input power quality. Individual control loops are designed for each power stage. A dual loop control scheme is employed to incorporate over-current limit on the proposed AWPS which ensures excellent weld bead quality. The proposed AWPS is implemented to validate its performance over a wide range of line/load variations. Test results confirm its fast parametrical response to load and source voltage variations and over-current protection leading to improved welding performance and weld bead quality. The system is found to perform extremely well with very low input current THD and unity power factor, adhering to international power quality norms.

  6. A new combined method in active filter design for power quality improvement in power systems.

    PubMed

    Hooshmand, Rahmat Allah; Torabian Esfahani, Mahdi

    2011-04-01

    The voltage & current harmonics produced by nonlinear loads in power systems cause a reduction in power quality. In order to improve the power quality, active power filters (APFs) can be used. In this paper, a new control system for designing active filters despite nonlinear loads of electric arc furnaces (EAFs) is presented. The system is composed of three main parts: computation of reference currents, regulation of DC capacitor voltage, and production of firing pulses. In the first part, the active filter control system is presented based on the combination of the synchronous detection method and instantaneous power theory. In the second part, the DC capacitor voltage regulator is applied, producing a reference current and a proper voltage regulator is developed. For the third part of the control system, we use a PI controller to provide some conditions that follow the reference current in a complete cycle, and generate firing pulses by the hysteresis method. The proposed control system not only reduces the voltage and current harmonics in power systems but can also improve the power quality indices. The above design was implemented in the EAF system of the Mobarakeh steel complex (Isfahan, Iran). The simulation results show the effectiveness of the APFs in improving the power quality indices.

  7. Results from power quality measurements in Germany - An overview

    SciTech Connect

    Gerdes, G.J.; Santjer, F.

    1996-12-31

    Grid interferences caused by wind turbines (WT) are getting a severe problem in Germany with the fast increasing number of installed turbines. The wind energy capacity was doubled annually in the past three years. The actual situation and the plannings for the next years will lead to a situation, where high wind energy penetration will exercise a big influence on the power and voltage quality of local utility networks. Measurements performed in Germany according to a national guideline show a big variety in power quality performance of WT`s, which does affect the requirements for grid connection and thus the economical situation of wind energy projects to a large extent. The results from more than 25 power quality measurements will be discussed in this paper. 5 refs., 5 figs., 1 tab.

  8. Review of power quality applications of energy storage systems

    SciTech Connect

    Swaminathan, S.; Sen, R.K.

    1997-05-01

    Under the sponsorship of the US Department of Energy (DOE) Office of Utility Technologies, the Energy Storage Systems Analysis and Development Department at Sandia National Laboratories contracted Sentech, Inc., to assess the impact of power quality problems on the electricity supply system. This report contains the results of several studies that have identified the cost of power quality events for electricity users and providers. The large annual cost of poor power quality represents a national inefficiency and is reflected in the cost of goods sold, reducing US competitiveness. The Energy Storage Systems (ESS) Program takes the position that mitigation merits the attention of not only the DOE but affected industries as well as businesses capable of assisting in developing solutions to these problems. This study represents the preliminary stages of an overall strategy by the ESS Program to understand the magnitude of these problems so as to begin the process of engaging industry partners in developing solutions.

  9. 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.

  10. How goal disturbance, coping and chest pain relate to quality of life: A study among patients waiting for PTCA.

    PubMed

    Echteld, M A; van Elderen, T M; van der Kamp, L J

    2001-01-01

    This article describes psychological correlates of quality of life (QOL) in patients on a waiting list for percutaneous transluminal coronary angioplasty (PTCA). Variables were selected based on a theoretical model describing psychological correlates of QOL in PTCA patients. This model was based on self-regulation and stress-coping theories. The variables in the model are stress appraisal, coping, coping resources, and general and disease-specific QOL variables. Respondents were 122 patients on a 3-month waiting list for a PTCA. Results indicated that PTCA patients had a poorer QOL than matched healthy controls. Using a path analysis approach to regression analysis, it appeared that goal disturbance, avoidant coping, approach coping, and chest pain were related to QOL. More specifically, chest pain and goal disturbance were only related to health-related QOL and negative affect. Both approach and avoidant coping were related to QOL variables. Results could be explained adequately using self-regulation theory. Recommendations for future research and for form and content of rehabilitation programmes were made.

  11. Potential impact of superconductivity on power quality enhancment

    NASA Astrophysics Data System (ADS)

    McConnell, B. W.

    1992-02-01

    Electric power quality problems are estimated to cost U.S. industry 26 billion dollars per year in lost production. This paper provides a summary of the problem's magnitude, an overview of the underlying causes, discusses the present methods used by industry to reduce the problem's impact and the associated cost, and examines the potential for superconducting technology to effect alternative solutions. The present market for uninterruptible power supplies (UPS) and power conditioners is also discussed and the benefits of applying high temperature superconductors (HTS) are summarized.

  12. The power of cueing to circumvent dopamine deficits: a review of physical therapy treatment of gait disturbances in Parkinson's disease.

    PubMed

    Rubinstein, Tamar C; Giladi, Nir; Hausdorff, Jeffrey M

    2002-11-01

    Gait disturbances are among the primary symptoms of Parkinson's disease (PD) and contribute significantly to a patient's loss of function and independence. Standard treatment includes antiparkinsonian drugs, primarily levodopa. In addition to the standard drug regime, physical therapy is often prescribed to help manage the disease. In recent years, there have been promising reports of physical therapy programs combined with various types of sensory cueing for PD. In this brief review of the literature, we summarize the evidence regarding the clinical efficacy of different physical therapy programs for PD, specifically with respect to improving gait. We also discuss the potential therapeutic mechanisms of sensory cueing and review the studies that have used cueing in the treatment of gait in PD. This review of the literature shows two key findings: (1) despite its relatively long history, the evidence supporting the efficacy of conventional physical therapy for treatment of gait in PD is not strong; and (2) although further investigation is needed, sensory cueing appears to be a powerful means of improving gait in PD.

  13. Capacity and reliability analyses with applications to power quality

    NASA Astrophysics Data System (ADS)

    Azam, Mohammad; Tu, Fang; Shlapak, Yuri; Kirubarajan, Thiagalingam; Pattipati, Krishna R.; Karanam, Rajaiah

    2001-07-01

    The deregulation of energy markets, the ongoing advances in communication networks, the proliferation of intelligent metering and protective power devices, and the standardization of software/hardware interfaces are creating a dramatic shift in the way facilities acquire and utilize information about their power usage. The currently available power management systems gather a vast amount of information in the form of power usage, voltages, currents, and their time-dependent waveforms from a variety of devices (for example, circuit breakers, transformers, energy and power quality meters, protective relays, programmable logic controllers, motor control centers). What is lacking is an information processing and decision support infrastructure to harness this voluminous information into usable operational and management knowledge to handle the health of their equipment and power quality, minimize downtime and outages, and to optimize operations to improve productivity. This paper considers the problem of evaluating the capacity and reliability analyses of power systems with very high availability requirements (e.g., systems providing energy to data centers and communication networks with desired availability of up to 0.9999999). The real-time capacity and margin analysis helps operators to plan for additional loads and to schedule repair/replacement activities. The reliability analysis, based on computationally efficient sum of disjoint products, enables analysts to decide the optimum levels of redundancy, aids operators in prioritizing the maintenance options for a given budget and monitoring the system for capacity margin. The resulting analytical and software tool is demonstrated on a sample data center.

  14. Quality Certification, Regulation and Power in Fair Trade

    ERIC Educational Resources Information Center

    Renard, Marie-Christine

    2005-01-01

    This article examines governance changes and shifting power relations within the fair-labelling network. These shifts are framed analytically by reference to broader changes in the agrofoods sector tied to the increasingly key role played by quality relations and standards in the production and marketing of food. The author argues that evident…

  15. Quality Certification, Regulation and Power in Fair Trade

    ERIC Educational Resources Information Center

    Renard, Marie-Christine

    2005-01-01

    This article examines governance changes and shifting power relations within the fair-labelling network. These shifts are framed analytically by reference to broader changes in the agrofoods sector tied to the increasingly key role played by quality relations and standards in the production and marketing of food. The author argues that evident…

  16. Anomaly Detection in Power Quality at Data Centers

    NASA Technical Reports Server (NTRS)

    Grichine, Art; Solano, Wanda M.

    2015-01-01

    The goal during my internship at the National Center for Critical Information Processing and Storage (NCCIPS) is to implement an anomaly detection method through the StruxureWare SCADA Power Monitoring system. The benefit of the anomaly detection mechanism is to provide the capability to detect and anticipate equipment degradation by monitoring power quality prior to equipment failure. First, a study is conducted that examines the existing techniques of power quality management. Based on these findings, and the capabilities of the existing SCADA resources, recommendations are presented for implementing effective anomaly detection. Since voltage, current, and total harmonic distortion demonstrate Gaussian distributions, effective set-points are computed using this model, while maintaining a low false positive count.

  17. Investigations of the quality of hospital electric power supply and the tolerance of medical electric devices to voltage dips.

    PubMed

    Hanada, Eisuke; Itoga, Shuuya; Takano, Kyoko; Kudou, Takato

    2007-06-01

    Medical devices driven by electric power have come to be commonly used in hospitals, and rapid changes of voltage or current can easily cause them to fail. A stable and high quality power supply is indispensable in order to maintain safety in the modern clinical setting. Therefore, we investigated the quality of the power supply in a hospital and determined the tolerance of 13 pieces of medical equipment to voltage dips. The results showed little distortion of the voltage wave. However, we found an approximately 7% momentary voltage dip caused by lightening and other problems, such as 2 to 5% periodic drops in voltage and voltage wave distortions caused by incorrect grounding. In a tolerance test, the settings of some medical devices were changed at the time of automatic reboot after a disturbance. For another device, trend information was initialized.

  18. Power quality control of an autonomous wind-diesel power system based on hybrid intelligent controller.

    PubMed

    Ko, Hee-Sang; Lee, Kwang Y; Kang, Min-Jae; Kim, Ho-Chan

    2008-12-01

    Wind power generation is gaining popularity as the power industry in the world is moving toward more liberalized trade of energy along with public concerns of more environmentally friendly mode of electricity generation. The weakness of wind power generation is its dependence on nature-the power output varies in quite a wide range due to the change of wind speed, which is difficult to model and predict. The excess fluctuation of power output and voltages can influence negatively the quality of electricity in the distribution system connected to the wind power generation plant. In this paper, the authors propose an intelligent adaptive system to control the output of a wind power generation plant to maintain the quality of electricity in the distribution system. The target wind generator is a cost-effective induction generator, while the plant is equipped with a small capacity energy storage based on conventional batteries, heater load for co-generation and braking, and a voltage smoothing device such as a static Var compensator (SVC). Fuzzy logic controller provides a flexible controller covering a wide range of energy/voltage compensation. A neural network inverse model is designed to provide compensating control amount for a system. The system can be optimized to cope with the fluctuating market-based electricity price conditions to lower the cost of electricity consumption or to maximize the power sales opportunities from the wind generation plant.

  19. Multiple disturbances classifier for electric signals using adaptive structuring neural networks

    NASA Astrophysics Data System (ADS)

    Lu, Yen-Ling; Chuang, Cheng-Long; Fahn, Chin-Shyurng; Jiang, Joe-Air

    2008-07-01

    This work proposes a novel classifier to recognize multiple disturbances for electric signals of power systems. The proposed classifier consists of a series of pipeline-based processing components, including amplitude estimator, transient disturbance detector, transient impulsive detector, wavelet transform and a brand-new neural network for recognizing multiple disturbances in a power quality (PQ) event. Most of the previously proposed methods usually treated a PQ event as a single disturbance at a time. In practice, however, a PQ event often consists of various types of disturbances at the same time. Therefore, the performances of those methods might be limited in real power systems. This work considers the PQ event as a combination of several disturbances, including steady-state and transient disturbances, which is more analogous to the real status of a power system. Six types of commonly encountered power quality disturbances are considered for training and testing the proposed classifier. The proposed classifier has been tested on electric signals that contain single disturbance or several disturbances at a time. Experimental results indicate that the proposed PQ disturbance classification algorithm can achieve a high accuracy of more than 97% in various complex testing cases.

  20. Tracing disturbance impacts on water quantity and quality through a stream network

    NASA Astrophysics Data System (ADS)

    Ross, Matthew; Nippgen, Fabian; McGlynn, Brian; Bernhardt, Emily

    2017-04-01

    By dismantling and redistributing 100s of meters of bedrock to mine coal from the surface, mountaintop mining with valley fills has dramatically changed catchment hydrology and biogeochemistry over more than 5,000 km2 in Central Appalachia. Throughout this expansive coal region, mining operators deposit tens of millions of m3 of crushed bedrock into headwater valleys, creating valley fills, which have substantial subsurface water storage potential. Streams draining mines have reduced peakflows, elevated baseflows, and lower event runoff ratios on average. The water stored in and percolating through valley fills drives the dissolution and oxidation of pyrite into sulfuric acid which reacts with carbonate-rich materials to rapidly weather out a suite of elements including Ca2+, Mg2+, K+, SO42-, HCO3-, and the pollutant Selenium. Together these ions increase the average specific conductance of mined streams from 60 to 1,500 µS/cm, 25-times higher than unmined streams, exporting 45-times more total dissolved solids. Together, the increased catchment storage, consequent elevated baseflow, and elevated weathering rates from mining have the potential to lower water quality throughout river networks in Central Appalachia, especially during the summer low flow period. To better understand the water quality impacts of mining at the river network scale, we used the paired catchment approach. Working in the Mud River, West Virginia, we instrumented a 4th order catchment 35 km2, that was 46% mined. Within the large catchment we instrumented 8 additional 1st-3rd order sub-catchments that varied in catchment size, mining cover, mine size, and mine age. At each site we measured stream discharge and specific conductance (SC). Using SC as a trace for mining we did simple hydrograph separations at our largest catchments, partitioning the hydrograph between mined and unmined water. Our results suggest that on an annual scale, mine water contributes a disproportionate percentage of

  1. Algal biomass in a disturbed Atlantic river: water quality relationships and environmental implications.

    PubMed

    Sabater, S; Armengol, J; Comas, E; Sabater, F; Urrizalqui, I; Urrutia, I

    2000-12-18

    Benthic algal biomass was determined at 38 sites along the Oria, a river with intense human activity on its watershed. Water temperature, total suspended solids and nutrient concentration affected algal biomass in different ways. Lower values of algal biomass [(chlorophyll-a concentration and ash-free dry weight (AFDW)] were found in the headwaters and forested tributaries, but also at sites receiving high deposition of solids (due to the outflow from paper mills and quarries). Higher values of algal biomass (both chlorophyll-a and AFDW) were common both in the main stretch of the river and in some tributaries receiving urban sewage outflows. Averages and ranges of temperature and dissolved oxygen concentration were compared for two continuously monitored stations. One of them (forested, nutrient-poor) had low algal biomass, while the second (open, nutrient-rich) showed high chlorophyll-a concentration. Accumulation of algal biomass had environmental implications both in water quality and in the fish diversity of the Oria. Diel variations of dissolved oxygen were much higher (and reached hypoxia) at the site with higher biomass accumulation. The abundance of a fish community (dominated by cyprinids) more tolerant to hypoxia at that site can partly be attributed to the influence of algal biomass accumulation.

  2. Disturbed dreaming and sleep quality: altered sleep architecture in subjects with frequent nightmares.

    PubMed

    Simor, Péter; Horváth, Klára; Gombos, Ferenc; Takács, Krisztina P; Bódizs, Róbert

    2012-12-01

    Nightmares are intense, emotionally negative mental experiences that usually occur during late-night sleep and result in abrupt awakenings. Questionnaire-based studies have shown that nightmares are related to impaired sleep quality; however, the polysomnographic profile of nightmare subjects has been only scarcely investigated. We investigated the sleep architecture of 17 individuals with frequent nightmares and 23 control subjects based on polysomnographic recordings of a second night spent in the laboratory after an adaptation night. Nightmare subjects in comparison with control subjects were characterized by impaired sleep architecture, as reflected by reduced sleep efficiency, increased wakefulness, a reduced amount of slow wave sleep, and increased nocturnal awakenings, especially from Stage 2 sleep. While these differences were independent of the effects of waking psychopathology, nightmare subjects also exhibited longer durations of REM sleep that was mediated by heightened negative affect. Our results support that nightmares are related to altered sleep architecture, showing impaired sleep continuity and emotion-related increase in REM propensity.

  3. An evaluation method of power quality about electrified railways connected to power grid based on PSCAD/EMTDC

    NASA Astrophysics Data System (ADS)

    Liang, Weibin; Ouyang, Sen; Huang, Xiang; Su, Weijian

    2017-05-01

    The existing modeling process of power quality about electrified railways connected to power grid is complicated and the simulation scene is incomplete, so this paper puts forward a novel evaluation method of power quality based on PSCAD/ETMDC. Firstly, a model of power quality about electrified railways connected to power grid is established, which is based on testing report or measured data. The equivalent model of electrified locomotive contains power characteristic and harmonic characteristic, which are substituted by load and harmonic source. Secondly, in order to make evaluation more complete, an analysis scheme has been put forward. The scheme uses a combination of three-dimensions of electrified locomotive, which contains types, working conditions and quantity. At last, Shenmao Railway is taken as example to evaluate the power quality at different scenes, and the result shows electrified railways connected to power grid have significant effect on power quality.

  4. Analysis of Power Quality Based on Real Data and Quality Improvement at Campus Distribution System

    NASA Astrophysics Data System (ADS)

    Kawasaki, Shoji; Matsuki, Junya; Hayashi, Yasuhiro; Ito, Akitoshi

    In recent years, a lot of equipments have been made using the inverter technology from home electric appliances to office automation apparatuses and industrial equipments with the development of power electronics technology. The voltage distortion of a distribution system has increased due to the harmonic currents generated from these apparatuses, and the increase in harmonics continues to be expected. In addition, the distribution system forms the circuit of harmonic distortion expansion by the prevalence of static capacitor without L for power factor improvement. Moreover, the voltage imbalance occurs by diversification of loads or imbalanced connection of single-phase loads. The deterioration of power quality in the distribution system causes various problems such as the overheating of equipments and malfunction of rotating machines. Since the power quality changes according to air temperature and date, it is desirable to measure the voltages and currents continuously for a long time. In this study, the authors focus attention on the distribution system in the University of Fukui campus, and the authors have measured the voltages and currents in the distribution system for a long period with WAMS (Wide Area Measurement System) using NCT (Network Computing Terminal). Based on the obtained data, the authors analyzed the power quality of the campus distribution system from viewpoints of voltage imbalance, current imbalance, voltage THD (Total Harmonic Distortion), and current THD. Furthermore, the improvement effect of power quality of the campus distribution system by exchange of single-phase load connection is described.

  5. Optical fiber system for combustion quality analysis in power boilers

    NASA Astrophysics Data System (ADS)

    Wojcik, Waldemar; Surtel, Wojciech; Smolarz, Andrzej; Kotyra, Andrzej; Komada, Pawel

    2001-06-01

    The introduction of low emission techniques of combustion caused side-effects like oxygen lean corrosion. It also enforced more precise management of technological air, better coal milling and application of devices for combustion process monitoring. In the article authors presented their own solution of optical fiber system for combustion quality evaluation, already operating on power boiler type OP-650. Its functionality was described together with selected results of measurements. Directions of further development of the system were also indicated.

  6. Longitudinal variation in suspended sediment and turbidity of two undisturbed streams in northwestern California in relation to the monitoring of water quality above and below a land disturbance

    Treesearch

    Steve G. Markman

    1990-01-01

    Abstract - In-stream water quality regulations of California state that silvicultural disturbances must not increase turbidity levels more than 20 percent above naturally occurring background levels. These regulations fail to take into account the natural variation of turbidity and suspended sediment concentration along a short stretch of an undisturbed stream. At...

  7. Artificial neural networks for control of a grid-connected rectifier/inverter under disturbance, dynamic and power converter switching conditions.

    PubMed

    Li, Shuhui; Fairbank, Michael; Johnson, Cameron; Wunsch, Donald C; Alonso, Eduardo; Proaño, Julio L

    2014-04-01

    Three-phase grid-connected converters are widely used in renewable and electric power system applications. Traditionally, grid-connected converters are controlled with standard decoupled d-q vector control mechanisms. However, recent studies indicate that such mechanisms show limitations in their applicability to dynamic systems. This paper investigates how to mitigate such restrictions using a neural network to control a grid-connected rectifier/inverter. The neural network implements a dynamic programming algorithm and is trained by using back-propagation through time. To enhance performance and stability under disturbance, additional strategies are adopted, including the use of integrals of error signals to the network inputs and the introduction of grid disturbance voltage to the outputs of a well-trained network. The performance of the neural-network controller is studied under typical vector control conditions and compared against conventional vector control methods, which demonstrates that the neural vector control strategy proposed in this paper is effective. Even in dynamic and power converter switching environments, the neural vector controller shows strong ability to trace rapidly changing reference commands, tolerate system disturbances, and satisfy control requirements for a faulted power system.

  8. Assessment of marine benthic quality change in gradients of disturbance: comparison of different Scandinavian multi-metric indices.

    PubMed

    Josefson, Alf B; Blomqvist, Mats; Hansen, Jørgen L S; Rosenberg, Rutger; Rygg, Brage

    2009-09-01

    Three multi-metric benthic macrofauna indices were used to assess marine benthic ecological quality status (EcoQS) according to the European Water Framework Directive, in seven pollution gradients mainly, western Scandinavia. The impacts included organic load, hypoxia, metals, urban effluents and physical disturbance. The indices responded in a similar threshold fashion, irrespective of impact factor identity. Usually, the border between Good and Moderate EcoQS (G/M), is determined as some deviation from a reference situation. References, however, are difficult to find. An alternative procedure is described to estimate the G/M border, not requiring reference data. Thresholds, where faunal structure deterioration commences, were identified from non-linear regressions between indices and impact factors. Index values from the less impacted side of the thresholds were assumed to come from environments of Good and High EcoQS, and the 5th percentile of these data, was defined as the G/M border. Estimated G/M borders compared well with previous studies.

  9. Influence of stocking, site quality, stand age, low-severity canopy disturbance, and forest composition on sub-boreal aspen mixedwood carbon stocks

    USGS Publications Warehouse

    Reinikainen, Michael; D’Amato, Anthony W.; Bradford, John B.; Fraver, Shawn

    2014-01-01

    Low-severity canopy disturbance presumably influences forest carbon dynamics during the course of stand development, yet the topic has received relatively little attention. This is surprising because of the frequent occurrence of such events and the potential for both the severity and frequency of disturbances to increase as a result of climate change. We investigated the impacts of low-severity canopy disturbance and average insect defoliation on forest carbon stocks and rates of carbon sequestration in mature aspen mixedwood forests of varying stand age (ranging from 61 to 85 years), overstory composition, stocking level, and site quality. Stocking level and site quality positively affected the average annual aboveground tree carbon increment (CAAI), while stocking level, site quality, and stand age positively affected tree carbon stocks (CTREE) and total ecosystem carbon stocks (CTOTAL). Cumulative canopy disturbance (DIST) was reconstructed using dendroecological methods over a 29-year period. DIST was negatively and significantly related to soil carbon (CSOIL), and it was negatively, albeit marginally, related to CTOTAL. Minima in the annual aboveground carbon increment of trees (CAI) occurred at sites during defoliation of aspen (Populus tremuloides Michx.) by forest tent caterpillar (Malacosoma disstria Hubner), and minima were more extreme at sites dominated by trembling aspen than sites mixed with conifers. At sites defoliated by forest tent caterpillar in the early 2000s, increased sequestration by the softwood component (Abies balsamea (L.) Mill. and Picea glauca (Moench) Voss) compensated for overall decreases in CAI by 17% on average. These results underscore the importance of accounting for low-severity canopy disturbance events when developing regional forest carbon models and argue for the restoration and maintenance of historically important conifer species within aspen mixedwoods to enhance stand-level resilience to disturbance agents and maintain

  10. The bidirectional relationship between pain intensity and sleep disturbance/quality in patients with low back pain.

    PubMed

    Alsaadi, Saad M; McAuley, James H; Hush, Julia M; Lo, Serigne; Bartlett, Delwyn J; Grunstein, Roland R; Maher, Chris G

    2014-09-01

    This study investigated the bidirectional relationship between the intensity of low back pain (LBP) and sleep disturbance. Further, the study aimed to determine whether any relationship is dependent on pain duration, symptoms of depression and anxiety, and the method of sleep assessment (subjective vs. objective). Eighty patients with LBP completed a sleep diary. A subgroup of 50 patients additionally wore an electronic device (Armband) to measure sleep for 7 consecutive days. Pain intensity was assessed twice daily using a sleep diary. Depression and anxiety symptoms were assessed at baseline using the Depression Anxiety Stress Scale questionnaire. Generalized estimating equations (GEE) with an exchangeable correlation structure were used to examine the relationship between day-time pain intensity and sleep. The GEE analysis showed that a night of poor sleep quality, difficulty falling sleep (assessed by the sleep diary), waking after sleep onset, and low sleep efficiency (assessed by the sleep diary and Armband) were followed by a day with higher pain intensity. Further, a day with higher pain intensity was associated with a decrease in the subsequent night's sleep quality, an increase in sleep latency (assessed by the sleep diary), waking after sleep onset (assessed by both measures), and low sleep efficiency (assessed by the Armband). The findings demonstrate that there is a bidirectional relationship between sleep and pain intensity in patients with LBP. The relationship is independent of pain duration and baseline symptoms of depression and anxiety and somewhat dependent on the method of sleep measurement (sleep diary or Armband). Future research is needed to determine whether targeting sleep improvement in patients with LBP contributes to pain reduction.

  11. Impacts of Western Area Power Administration`s power marketing alternatives on air quality and noise

    SciTech Connect

    Chun, K.C.; Chang, Y.S.; Rabchuk, J.A.

    1995-05-01

    The Western Area Power Administration, which is responsible for marketing electricity produced at the hydroelectric power-generating facilities operated by the Bureau of Reclamation on the Upper Colorado River, has proposed changes in the levels of its commitment (sales) of long-term firm capacity and energy to its customers. This report describes (1) the existing conditions of air resources (climate and meteorology, ambient air quality, and acoustic environment) of the region potentially affected by the proposed action and (2) the methodology used and the results of analyses conducted to assess the potential impacts on air resources of the proposed action and the commitment-level alternatives. Analyses were performed for the potential impacts of both commitment-level alternatives and supply options, which include combinations of electric power purchases and different operational scenarios of the hydroelectric power-generating facilities.

  12. Enhanced power quality based single phase photovoltaic distributed generation system

    NASA Astrophysics Data System (ADS)

    Panda, Aurobinda; Pathak, M. K.; Srivastava, S. P.

    2016-08-01

    This article presents a novel control strategy for a 1-ϕ 2-level grid-tie photovoltaic (PV) inverter to enhance the power quality (PQ) of a PV distributed generation (PVDG) system. The objective is to obtain the maximum benefits from the grid-tie PV inverter by introducing current harmonics as well as reactive power compensation schemes in its control strategy, thereby controlling the PV inverter to achieve multiple functions in the PVDG system such as: (1) active power flow control between the PV inverter and the grid, (2) reactive power compensation, and (3) grid current harmonics compensation. A PQ enhancement controller (PQEC) has been designed to achieve the aforementioned objectives. The issue of underutilisation of the PV inverter in nighttime has also been addressed in this article and for the optimal use of the system; the PV inverter is used as a shunt active power filter in nighttime. A prototype model of the proposed system is developed in the laboratory, to validate the effectiveness of the control scheme, and is tested with the help of the dSPACE DS1104 platform.

  13. Long range laser propagation: power scaling and beam quality issues

    NASA Astrophysics Data System (ADS)

    Bohn, Willy L.

    2010-09-01

    This paper will address long range laser propagation applications where power and, in particular beam quality issues play a major role. Hereby the power level is defined by the specific mission under consideration. I restrict myself to the following application areas: (1)Remote sensing/Space based LIDAR, (2) Space debris removal (3)Energy transmission, and (4)Directed energy weapons Typical examples for space based LIDARs are the ADM Aeolus ESA mission using the ALADIN Nd:YAG laser with its third harmonic at 355 nm and the NASA 2 μm Tm:Ho:LuLiF convectively cooled solid state laser. Space debris removal has attracted more attention in the last years due to the dangerous accumulation of debris in orbit which become a threat to the satellites and the ISS space station. High power high brightness lasers may contribute to this problem by partially ablating the debris material and hence generating an impulse which will eventually de-orbit the debris with their subsequent disintegration in the lower atmosphere. Energy transmission via laser beam from space to earth has long been discussed as a novel long term approach to solve the energy problem on earth. In addition orbital transfer and stationkeeping are among the more mid-term applications of high power laser beams. Finally, directed energy weapons are becoming closer to reality as corresponding laser sources have matured due to recent efforts in the JHPSSL program. All of this can only be realized if he laser sources fulfill the necessary power requirements while keeping the beam quality as close as possible to the diffraction limited value. And this is the rationale and motivation of this paper.

  14. Microphone array power ratio for quality assessment of reverberated speech

    NASA Astrophysics Data System (ADS)

    Berkun, Reuven; Cohen, Israel

    2015-12-01

    Speech signals in enclosed environments are often distorted by reverberation and noise. In speech communication systems with several randomly distributed microphones, involving a dynamic speaker and unknown source location, it is of great interest to monitor the perceived quality at each microphone and select the signal with the best quality. Most of existing approaches for quality estimation require prior information or a clean reference signal, which is unfortunately seldom available. In this paper, a practical non-intrusive method for quality assessment of reverberated speech signals is proposed. Using a statistical model of the reverberation process, we examine the energies as measured by unidirectional elements in a microphone array. By measuring the power ratio, we obtain a measure for the amount of reverberation in the received acoustic signals. This measure is then utilized to derive a blind estimation of the direct-to-reverberation energy ratio in the room. The proposed approach attains a simple, reliable, and robust quality measure, shown here through persuasive simulation results.

  15. Sleep Disturbances

    MedlinePlus

    ... PD / Coping with Symptoms & Side Effects / Sleep Disturbances Sleep Disturbances Many people with Parkinson’s disease (PD) have ... stay awake during the day. Tips for Better Sleep People with PD — and their care partners too — ...

  16. Recovery of condensate water quality in power generator's surface condenser

    NASA Astrophysics Data System (ADS)

    Kurniawan, Lilik Adib

    2017-03-01

    In PT Badak NGL Plant, steam turbines are used to drive major power generators, compressors, and pumps. Steam exiting the turbines is condensed in surface condensers to be returned to boilers. Therefore, surface condenser performance and quality of condensate water are very important. One of the recent problem was caused by the leak of a surface condenser of Steam Turbine Power Generator. Thesteam turbine was overhauled, leaving the surface condenser idle and exposed to air for more than 1.5 years. Sea water ingress due to tube leaks worsens the corrosionof the condenser shell. The combination of mineral scale and corrosion product resulting high conductivity condensate at outlet condenser when we restarted up, beyond the acceptable limit. After assessing several options, chemical cleaning was the best way to overcome the problem according to condenser configuration. An 8 hour circulation of 5%wt citric acid had succeed reducing water conductivity from 50 μmhos/cm to below 5 μmhos/cm. The condensate water, then meets the required quality, i.e. pH 8.3 - 9.0; conductivity ≤ 5 μmhos/cm, therefore the power generator can be operated normally without any concern until now.

  17. Effects of land use types on surface water quality across an anthropogenic disturbance gradient in the upper reach of the Hun River, Northeast China.

    PubMed

    Wang, Ruizhao; Xu, Tianle; Yu, Lizhong; Zhu, Jiaojun; Li, Xiaoyu

    2013-05-01

    Surface water quality is vulnerable to pollution due to human activities. The upper reach of the Hun River is an important water source that supplies 52 % of the storage capacity of the Dahuofang Reservoir, the largest reservoir for drinking water in Northeast China, which is suffering from various human-induced changes in land use, including deforestation, reclamation/farming, urbanization and mine exploitation. To investigate the impacts of land use types on surface water quality across an anthropogenic disturbance gradient at a local scale, 11 physicochemical parameters (pH, dissolved oxygen [DO], turbidity, oxygen redox potential, conductivity, biochemical oxygen demand [BOD5], chemical oxygen demand [COD], total nitrogen [TN], total phosphorus [TP], NO(3)(-)N, and NH(4)(+)-N) of water from 12 sampling sites along the upper reach of the Hun River were monitored monthly during 2009-2010. The sampling sites were classified into four groups (natural, near-natural, more disturbed, and seriously disturbed). The water quality exhibited distinct spatial and temporal characteristics; conductivity, TN, and NO(3)(-)-N were identified as key parameters indicating the water quality variance. The forest and farmland cover types played significant roles in determining the surface water quality during the low-flow, high-flow, and mean-flow periods based on the results of a stepwise linear regression. These results may provide incentive for the local government to consider sustainable land use practices for water conservation.

  18. Artificial enzyme-powered microfish for water-quality testing.

    PubMed

    Orozco, Jahir; García-Gradilla, Victor; D'Agostino, Mattia; Gao, Wei; Cortés, Allan; Wang, Joseph

    2013-01-22

    We present a novel micromotor-based strategy for water-quality testing based on changes in the propulsion behavior of artificial biocatalytic microswimmers in the presence of aquatic pollutants. The new micromotor toxicity testing concept mimics live-fish water testing and relies on the toxin-induced inhibition of the enzyme catalase, responsible for the biocatalytic bubble propulsion of tubular microengines. The locomotion and survival of the artificial microfish are thus impaired by exposure to a broad range of contaminants, that lead to distinct time-dependent irreversible losses in the catalase activity, and hence of the propulsion behavior. Such use of enzyme-powered biocompatible polymeric (PEDOT)/Au-catalase tubular microengine offers highly sensitive direct optical visualization of changes in the swimming behavior in the presence of common contaminants and hence to a direct real-time assessment of the water quality. Quantitative data on the adverse effects of the various toxins upon the swimming behavior of the enzyme-powered artificial swimmer are obtained by estimating common ecotoxicological parameters, including the EC(50) (exposure concentration causing 50% attenuation of the microfish locomotion) and the swimmer survival time (lifetime expectancy). Such novel use of artificial microfish addresses major standardization and reproducibility problems as well as ethical concerns associated with live-fish toxicity assays and hence offers an attractive alternative to the common use of aquatic organisms for water-quality testing.

  19. Words Have Power: (Re)-Defining Serious Emotional Disturbance for American Indian and Alaska Native Children and Their Families

    ERIC Educational Resources Information Center

    Simmons, Teisha M.; Novins, Douglas K.; Allen, James

    2004-01-01

    Circles of Care grantees were provided the opportunity to develop a locally relevant definition of serious emotional disturbance (SED) that would be used to define what type of emotional, behavioral, and mental disability would be required to receive services. After conducting detailed assessments of the definition in the guidance for applicants…

  20. [Psychosomatic disturbances in clean-up personnel at the Chernobyl nuclear power plant who had previous histories of insult].

    PubMed

    Kazakova, S E; Toporkova, O A; Pin'kas, V H; Vatans'ka, I Iu

    2003-01-01

    Chornobyl APS--after--effects liquidators were examined. While objective examination the following changes were registered in the patients: slowing down the rate of psychical activity (51%), lowering of mental labor efficiency; the patients spent a lot of time to carry out some kind of work. As the severity of the disease aggravated, the immune disturbances were growing.

  1. UH-60 Black Hawk Disturbance Rejection Study for Hover/Low Speed Handling Qualities Criteria and Turbulence Modeling

    NASA Technical Reports Server (NTRS)

    Labows, Steven J.; Blanken, Chris L.; Tischler, Mark B.

    1999-01-01

    This paper will discuss the airborne flight test of the Sikorsky UH-60 Black Hawk helicopter in turbulent conditions to determine disturbance rejection criteria and develop a low speed wind/turbulence model for helicopter simulation.

  2. Quality engineering tools focused on high power LED driver design using boost power stages in switch mode

    NASA Astrophysics Data System (ADS)

    Ileana, Ioan; Risteiu, Mircea; Marc, Gheorghe

    2016-12-01

    This paper is a part of our research dedicated to high power LED lamps designing. The boost-up selected technology wants to meet driver producers' tendency in the frame of efficiency and disturbances constrains. In our work we used modeling and simulation tools for implementing scenarios of the driver work when some controlling functions are executed (output voltage/ current versus input voltage and fixed switching frequency, input and output electric power transfer versus switching frequency, transient inductor voltage analysis, and transient out capacitor analysis). Some electrical and thermal stress conditions are also analyzed. Based on these aspects, a high reliable power LED driver has been designed.

  3. Development of an expert system for power quality advisement using CLIPS 6.0

    NASA Technical Reports Server (NTRS)

    Chandrasekaran, A.; Sarma, P. R. R.; Sundaram, Ashok

    1994-01-01

    Proliferation of power electronic devices has brought in its wake both deterioration in and demand for quality power supply from the utilities. The power quality problems become apparent when the user's equipment or systems maloperate or fail. Since power quality concerns arise from a wide variety of sources and the problem fixes are better achieved from the expertise of field engineers, development of an expert system for power quality advisement seems to be a very attractive and cost-effective solution for utility applications. An expert system thus developed gives an understanding of the adverse effects of power quality related problems on the system and could help in finding remedial solutions. The paper reports the design of a power quality advisement expert system being developed using CLIPS 6.0. A brief outline of the power quality concerns is first presented. A description of the knowledge base is next given and details of actual implementation include screen output from the program.

  4. Application of disturbance analysis methodology to safety related transients in the electrical systems of a nuclear power plant. Report UCLA-ENG-8056

    SciTech Connect

    Guarro, S.; Okrent, D.

    1981-08-01

    The present study tries to address the question of whether or not the computerized on-line procedures known under the name of DAS (Disturbance Analysis System) can be usefully and successfully applied to provide timely diagnostics and operational suggestions during the occurrence of a major electrical transient in the auxiliary systems of a nuclear power plant. The perspective of the study is from the plant-safety point of view. A short definition of DAS methodology features and capabilities is presented. A discussion of some of the problems of a general nature that are encountered in DAS safety-oriented applications are also included. The event insufficient power on both emergency buses, with reference to a particular plant dsign (San Onofre 1), is presented. Some transients that have recently occurred in the power supply systems of operating plants are examined. Whether or not a DAS could have successfully dealt with such occurrences is considered.

  5. Sleep Disturbances in Individuals With Phelan-McDermid Syndrome: Correlation With Caregivers' Sleep Quality and Daytime Functioning.

    PubMed

    Bro, Della; O'Hara, Ruth; Primeau, Michelle; Hanson-Kahn, Andrea; Hallmayer, Joachim; Bernstein, Jonathan A

    2017-02-01

    The aims of this study were to document sleep disturbances in individuals with Phelan-McDermid syndrome (PMS), to assess whether these individuals had been evaluated for sleep disorders, and to examine relationships between the sleep behavior of these individuals and the sleep behavior and daytime functioning of their caregivers. Participants were 193 caregivers of individuals with PMS recruited by the Phelan-McDermid Syndrome Foundation. Data were collected through a survey comprising 2 questionnaires: the Children's Sleep Habits Questionnaire (CSHQ) and the Parents' Sleep Habits Questionnaire. Data were analyzed using multiple linear regression analyses, Pearson correlation analyses, and independent-samples t-tests. Ninety percent of individuals with PMS showed evidence of marked sleep disturbance based on caregiver responses to the CSHQ. However, only 22% of individuals had undergone a formal sleep assessment. Reported increased sleep disturbance in individuals with PMS was a statistically significant predictor of reported increased sleep disturbance and daytime sleepiness in their caregivers. Sleep disturbance may be present in a substantial proportion of individuals with PMS and is negatively associated with caregivers' well-being. However, most individuals with PMS have not been evaluated for sleep disorders. When properly diagnosed, many sleep disorders can be alleviated with intervention. Thus, routine screening for and evaluation of sleep disturbances in individuals with PMS may have long-term positive impacts on the well-being of these individuals and their caregivers.

  6. Rapid algorithm prototyping and implementation for power quality measurement

    NASA Astrophysics Data System (ADS)

    Kołek, Krzysztof; Piątek, Krzysztof

    2015-12-01

    This article presents a Model-Based Design (MBD) approach to rapidly implement power quality (PQ) metering algorithms. Power supply quality is a very important aspect of modern power systems and will become even more important in future smart grids. In this case, maintaining the PQ parameters at the desired level will require efficient implementation methods of the metering algorithms. Currently, the development of new, advanced PQ metering algorithms requires new hardware with adequate computational capability and time intensive, cost-ineffective manual implementations. An alternative, considered here, is an MBD approach. The MBD approach focuses on the modelling and validation of the model by simulation, which is well-supported by a Computer-Aided Engineering (CAE) packages. This paper presents two algorithms utilized in modern PQ meters: a phase-locked loop based on an Enhanced Phase Locked Loop (EPLL), and the flicker measurement according to the IEC 61000-4-15 standard. The algorithms were chosen because of their complexity and non-trivial development. They were first modelled in the MATLAB/Simulink package, then tested and validated in a simulation environment. The models, in the form of Simulink diagrams, were next used to automatically generate C code. The code was compiled and executed in real-time on the Zynq Xilinx platform that combines a reconfigurable Field Programmable Gate Array (FPGA) with a dual-core processor. The MBD development of PQ algorithms, automatic code generation, and compilation form a rapid algorithm prototyping and implementation path for PQ measurements. The main advantage of this approach is the ability to focus on the design, validation, and testing stages while skipping over implementation issues. The code generation process renders production-ready code that can be easily used on the target hardware. This is especially important when standards for PQ measurement are in constant development, and the PQ issues in emerging smart

  7. Resolution-Enhanced Harmonic and Interharmonic Measurement for Power Quality Analysis in Cyber-Physical Energy System.

    PubMed

    Liu, Yanchi; Wang, Xue; Liu, Youda; Cui, Sujin

    2016-06-27

    Power quality analysis issues, especially the measurement of harmonic and interharmonic in cyber-physical energy systems, are addressed in this paper. As new situations are introduced to the power system, the impact of electric vehicles, distributed generation and renewable energy has introduced extra demands to distributed sensors, waveform-level information and power quality data analytics. Harmonics and interharmonics, as the most significant disturbances, require carefully designed detection methods for an accurate measurement of electric loads whose information is crucial to subsequent analyzing and control. This paper gives a detailed description of the power quality analysis framework in networked environment and presents a fast and resolution-enhanced method for harmonic and interharmonic measurement. The proposed method first extracts harmonic and interharmonic components efficiently using the single-channel version of Robust Independent Component Analysis (RobustICA), then estimates the high-resolution frequency from three discrete Fourier transform (DFT) samples with little additional computation, and finally computes the amplitudes and phases with the adaptive linear neuron network. The experiments show that the proposed method is time-efficient and leads to a better accuracy of the simulated and experimental signals in the presence of noise and fundamental frequency deviation, thus providing a deeper insight into the (inter)harmonic sources or even the whole system.

  8. Resolution-Enhanced Harmonic and Interharmonic Measurement for Power Quality Analysis in Cyber-Physical Energy System

    PubMed Central

    Liu, Yanchi; Wang, Xue; Liu, Youda; Cui, Sujin

    2016-01-01

    Power quality analysis issues, especially the measurement of harmonic and interharmonic in cyber-physical energy systems, are addressed in this paper. As new situations are introduced to the power system, the impact of electric vehicles, distributed generation and renewable energy has introduced extra demands to distributed sensors, waveform-level information and power quality data analytics. Harmonics and interharmonics, as the most significant disturbances, require carefully designed detection methods for an accurate measurement of electric loads whose information is crucial to subsequent analyzing and control. This paper gives a detailed description of the power quality analysis framework in networked environment and presents a fast and resolution-enhanced method for harmonic and interharmonic measurement. The proposed method first extracts harmonic and interharmonic components efficiently using the single-channel version of Robust Independent Component Analysis (RobustICA), then estimates the high-resolution frequency from three discrete Fourier transform (DFT) samples with little additional computation, and finally computes the amplitudes and phases with the adaptive linear neuron network. The experiments show that the proposed method is time-efficient and leads to a better accuracy of the simulated and experimental signals in the presence of noise and fundamental frequency deviation, thus providing a deeper insight into the (inter)harmonic sources or even the whole system. PMID:27355946

  9. "Power quality system," a new system of quality management for globalization: towards innovation and competitive advantages.

    PubMed

    Abdul-Rahman, H; Berawi, M A

    Knowledge Management (KM) addresses the critical issues of organizational adoption, survival and competence in the face of an increasingly changing environment. KM embodies organizational processes that seek a synergistic combination of the data and information processing capabilities of information and communication technologies (ICT), and the creative and innovative capacity of human beings to improve ICT In that role, knowledge management will improve quality management and avoid or minimize losses and weakness that usually come from poor performance as well as increase the competitive level of the company and its ability to survive in the global marketplace. To achieve quality, all parties including the clients, company consultants, contractors, entrepreneurs, suppliers, and the governing bodies (i.e., all involved stake-holders) need to collaborate and commit to achieving quality. The design based organizations in major business and construction companies have to be quality driven to support healthy growth in today's competitive market. In the march towards vision 2020 and globalization (i.e., the one world community) of many companies, their design based organizations need to have superior quality management and knowledge management to anticipate changes. The implementation of a quality system such as the ISO 9000 Standards, Total Quality Management, or Quality Function Deployment (QFD) focuses the company's resources towards achieving faster and better results in the global market with less cost. To anticipate the needs of the marketplace and clients as the world and technology change, a new system, which we call Power Quality System (PQS), has been designed. PQS is a combination of information and communication technologies (ICT) and the creative and innovative capacity of human beings to meet the challenges of the new world business and to develop high quality products.

  10. Improving Read Disturb Characteristics by Using Double Common Source Line and Dummy Switch Architecture in Multi Level Cell NAND Flash Memory with Low Power Consumption

    NASA Astrophysics Data System (ADS)

    Kang, Myounggon; Park, Ki-Tae; Song, Youngsun; Lim, Youngho; Suh, Kang-Deog; Shin, Hyungcheol

    2011-04-01

    Two new NAND structures using double common source line (CSL) and dummy switch and their read operation schemes as a solution for NAND flash memories have been proposed. Compared with conventional scheme, the proposed read schemes improves read disturb characteristics beyond sub-30 nm technology node. By using proposed read scheme, the number of fail bits of proposed NAND was decreased than those of conventional NAND at read cycles. Also, it was proven that they contribute to improve the performance and suppress the power consumption. The proposed NAND was verified by both simulation and experimental measurements in a fabricated 40 nm multi level cell (MLC) NAND device.

  11. High quality thick epitaxial films for power semiconductor devices

    NASA Astrophysics Data System (ADS)

    Chang, Hsueh-Rong; Temple, V. A. K.

    1986-01-01

    High quality epitaxial layers with low defect levels are the key to fabrication of high voltage power devices. Growth of 100 μm thick epitaxial layers has been performed using a thermally driven chemical vapor deposition process. Three important parameters that have significant influence on epitaxy quality have been identified: substrate surface condition, reactor system cleanliness, and deposition process. The prerequisite p- n- p structure of a 6 kV thyristor was fabricated using 100 μm thick epitaxial layers to form the p-base. Defect density (hillocks and dislocations) in epitaxial layers has been correlated with the breakdown voltage of the p- n- p structure. It was found that an order of magnitude improvement of the defect level was obtained using well polished substrates instead of poorly polished substrates. Further improvement was achieved with the use of an etched reactor system before epitaxial growth, resulting in the reduction of defect density by another order of magnitude. A new cycled process, consisting of successive H 2 purges and deposition steps, is proposed that effectively reduces the defect level by an additional factor of 4, as compared with the conventional continuous deposition process. Specular epitaxial layers without spikes were obtained. Experimental results showed that for thick epitaxial films (100 μm), a susceptor with round-bottomed depressions provides higher dislocation density than one with flat-bottomed depressions, leading to a lower breakdown voltage of test devices.

  12. Microscale air quality impacts of distributed power generation facilities.

    PubMed

    Olaguer, Eduardo P; Knipping, Eladio; Shaw, Stephanie; Ravindran, Satish

    2016-08-01

    The electric system is experiencing rapid growth in the adoption of a mix of distributed renewable and fossil fuel sources, along with increasing amounts of off-grid generation. New operational regimes may have unforeseen consequences for air quality. A three-dimensional microscale chemical transport model (CTM) driven by an urban wind model was used to assess gaseous air pollutant and particulate matter (PM) impacts within ~10 km of fossil-fueled distributed power generation (DG) facilities during the early afternoon of a typical summer day in Houston, TX. Three types of DG scenarios were considered in the presence of motor vehicle emissions and a realistic urban canopy: (1) a 25-MW natural gas turbine operating at steady state in either simple cycle or combined heating and power (CHP) mode; (2) a 25-MW simple cycle gas turbine undergoing a cold startup with either moderate or enhanced formaldehyde emissions; and (3) a data center generating 10 MW of emergency power with either diesel or natural gas-fired backup generators (BUGs) without pollution controls. Simulations of criteria pollutants (NO2, CO, O3, PM) and the toxic pollutant, formaldehyde (HCHO), were conducted assuming a 2-hr operational time period. In all cases, NOx titration dominated ozone production near the source. The turbine scenarios did not result in ambient concentration enhancements significantly exceeding 1 ppbv for gaseous pollutants or over 1 µg/m(3) for PM after 2 hr of emission, assuming realistic plume rise. In the case of the datacenter with diesel BUGs, ambient NO2 concentrations were enhanced by 10-50 ppbv within 2 km downwind of the source, while maximum PM impacts in the immediate vicinity of the datacenter were less than 5 µg/m(3). Plausible scenarios of distributed fossil generation consistent with the electricity grid's transformation to a more flexible and modernized system suggest that a substantial amount of deployment would be required to significantly affect air quality on

  13. Power Sharing Control between Load-Side Inverters in DC Microgrid for Super High Quality Electric Power Distribution System

    NASA Astrophysics Data System (ADS)

    Kakigano, Hiroaki; Nada, Kaho; Miura, Yushi; Ise, Toshifumi; Uchida, Ryohei

    DC microgrid is a novel power system using dc distribution in order to provide a super high quality electric power. The dc distribution system is suitable for dc output type distributed generations such as photovoltaic and fuel cells, and energy storages such as batteries and electric double layer capacitors. Power is distributed through dc distribution line and converted to required ac or dc voltage by converters placed near loads. Load-side single phase inverters are connected through transformers in order to share active and reactive power. In this paper, a power sharing control scheme was proposed, and the power sharing characteristics were demonstrated by experimental results.

  14. Buprenorphine Transdermal System Improves Sleep Quality and Reduces Sleep Disturbance in Patients with Moderate-to-Severe Chronic Low Back Pain: Results from Two Randomized Controlled Trials.

    PubMed

    Yarlas, Aaron; Miller, Kate; Wen, Warren; Lynch, Shau Yu; Ripa, Steven R; Pergolizzi, Joseph V; Raffa, Robert B

    2016-03-01

    To evaluate the impact of buprenorphine (Butrans®) transdermal System (BTDS) treatment on sleep outcomes for patients with moderate-to-severe chronic low back pain (CLBP). Two enriched-enrollment, randomized-withdrawal, double-blind, controlled trials examined BTDS treatment for patients with moderate-to-severe CLBP. Trial I evaluated BTDS 10 and 20 mcg/hour against a placebo control among opioid-naïve patients. Trial II compared BTDS 20 mcg/hour against a lower-dose control (BTDS 5 mcg/hour) among opioid-experienced patients. The patient-reported Medical Outcomes Study Sleep Scale (MOS-SS) assessed overall sleep quality (Sleep Problems Index [SPI]), Disturbance, and other sleep outcomes. In each trial, MOS-SS scores were compared between target treatment and control arms during the 12-week double-blind phase. Correspondence of changes in sleep outcomes and pain severity and the degree to which pain reduction mediates treatment impact on sleep outcomes were examined. Medical Outcomes Study Sleep Scale scores were collected from 541 (Trial I) and 441 (Trial II) patients prior to randomization and from 369 (Trial I) and 274 (Trial II) patients at week 12. Patients receiving target treatment showed statistically significantly more improvement in SPI and Disturbance scores at 12 weeks than their respective controls (Ps < 0.05). Improvements in SPI and Disturbance for target treatment arms were statistically larger those of the controls by week 4 of the double-blind phase. The clinical significance of these differences was not determined. Pain reduction predicted improvements in sleep outcomes. Buprenorphine Transdermal System improved sleep quality and disturbance for opioid-naïve and opioid-experienced patients with moderate-to-severe CLBP. Benefits of BTDS for these sleep outcomes emerged within 4 weeks and were maintained over the entire 12-week treatment period. © 2015 Optum. Pain Practice published by Wiley Periodicals, Inc. on behalf of World Institute of

  15. Emotional Disturbance

    MedlinePlus

    ... terms such as emotional disturbance, behavioral disorders, or mental illness. Beneath these umbrella terms, there is actually a ... may also be affected. The National Alliance on Mental Illness (NAMI) puts this very well: Mental illnesses are ...

  16. Research on comprehensive power quality compensation schemes based on series and shunt converters

    NASA Astrophysics Data System (ADS)

    Jia, Dongqiang; He, Rongkai; Qian, Yeniu

    2017-01-01

    To solve power quality problems such as voltage sag and low power factor which may occur simultaneously. This paper has taken research on two comprehensive power quality compensation schemes based on series and shunt converters, including corresponding topology structure and operation principle, meanwhile, the equivalent circuit and power flow analysis are also given. Then the paper has discussed relative characteristics of schemes, such as flexibility, reliability and applications. Finally, simulation results have verified effectiveness of related analysis of schemes.

  17. Non-disturbing optical power monitor for links in the visible spectrum using a polymer optical fibre

    NASA Astrophysics Data System (ADS)

    Ribeiro, Ricardo M.; Freitas, Taiane A. M. G.; Barbero, Andrés P. L.; Silva, Vinicius N. H.

    2015-08-01

    We describe a simple and inexpensive inline optical power monitor (OPMo) for polymer optical fibre (POF) links that are transmitting visible light carriers. The OPMo is non-invasive in the sense that it does not tap any guided light from the fibre core; rather, it collects and detects the spontaneous side-scattered light. Indeed, the OPMo indicates whether a POF transmission link has dark or live status and measures the average optical power level of the propagating signals without disconnecting the fibre link. This paper demonstrates the proof-of-principle of the device for one wavelength at a time, selected from a set of previously calibrated wavelength channels which have been found in the 45 dB dynamic range, with 50 dBm sensitivity or insensitivity by the use or non-use of a mode scrambler. Our findings are very promising milestones for further OPMo development towards the marketplace.

  18. Second-order small disturbance theory for hypersonic flow over power-law bodies. Ph.D. Thesis

    NASA Technical Reports Server (NTRS)

    Townsend, J. C.

    1974-01-01

    A mathematical method for determining the flow field about power-law bodies in hypersonic flow conditions is developed. The second-order solutions, which reflect the effects of the second-order terms in the equations, are obtained by applying the method of small perturbations in terms of body slenderness parameter to the zeroth-order solutions. The method is applied by writing each flow variable as the sum of a zeroth-order and a perturbation function, each multiplied by the axial variable raised to a power. The similarity solutions are developed for infinite Mach number. All results obtained are for no flow through the body surface (as a boundary condition), but the derivation indicates that small amounts of blowing or suction through the wall can be accommodated.

  19. Motor disturbances and thalamic electrical power of frequency bands' improve by grape seed extract in animal model of Parkinson's disease

    PubMed Central

    Sarkaki, Alireza; Eidypour, Zainab; Motamedi, Freshteh; keramati, keivan; Farbood, Yaghoub

    2012-01-01

    Objective: Previous studies showed that grape seed extract (GSE) is an excellent natural substance with potent antioxidant effect and free radical scavenger. This study aimed to evaluate the effect of GSE on motor dysfunctions and thalamic local Electroencephalography (EEG) frequency bands' powers in rats with Parkinson's disease (PD). Materials and Methods: In this study 8 µg 6-hydroxydopamine (6-OHDA) dissolved in 2 µl normal saline containing 0.01% ascorbic acid was infused into right medial forebrain bundle (MFB) to make an animal model of PD. Rats with PD received four weeks GSE (100 mg/kg, p.o.) after apomorphine-induced rotation test. Spontaneous motor tests and also thalamic ventroanterior nucleus (AV) local EEG recording were done in freely moving rats in all groups. Results: Chronic treatment of PD rats with GSE could influence potentially frequency bands' powers of thalamic VA and improve post-lesion motor dysfunctions significantly (p<0.05 and p<0.01, respectively). Conclusion: Our findings suggest that GSE modulates the CNS function and has beneficial effects on the direct and indirect striato-thalamo-cortical pathways in PD. GSE acts as a new and potent natural free radical scavenger which removes oxidants produced by neurotoxin 6-OHDA in brain. Therefore, it reinforces electrical power of remained thalamic VA neurons and thereby improves post-lesion motor disorders. PMID:25050252

  20. Prevalence and correlates of sleep disturbance in systemic sclerosis—results from the UCLA scleroderma quality of life study

    PubMed Central

    Frech, Tracy; Hays, Ron D.; Maranian, Paul; Clements, Philip J.; Furst, Daniel E.

    2011-01-01

    Objective. Rheumatologic disorders are associated with sleep disturbances. This study examines sleep disturbance correlates in patients with SSc. Methods. Participants are 180 SSc patients in an observational study. At baseline, patients completed the Medical Outcomes Study Sleep measure (MOS-Sleep scale). In addition, patients were administered other patient-reported outcome (PRO) measures including the 36-item short form (SF-36), HAQ disability index (HAQ-DI), Functional Assessment of Chronic Illness Therapy-Fatigue (FACIT-Fatigue), Center for Epidemiologic Studies Depression (CESD) scale and a University of California at Los Angeles Scleroderma Clinical Trial Consortium Gastrointestinal Tract Questionnaire (UCLA SCTC GIT 2.0). Descriptive statistics were assessed for six scales of MOS-Sleep and the 9-item sleep problem index (SLP-9; a composite index). We computed Spearman’s rank-order correlations between the MOS-Sleep scales and the HAQ-DI, FACIT-Fatigue, CESD, SSc-SCTC GIT 2.0 and SF-36 scales. In addition, we developed a regression model to assess predictors of SLP-9 scores. Covariates included demographics, physician variables of disease severity and patient-reported variables of worsening symptoms and the PRO measures. Results. SSc patients reported a mean (s.d.) of 7.1 (1.73) h of sleep a night. Patients reported worse scores on four of six scales (except for snoring and sleep quantity) compared with the US general population (P < 0.001). SLP-9 was correlated with worsening pain and dyspnoea over the past 1 month, reflux scale of the UCLA SCTC GIT 2.0, CESD and FACIT-Fatigue (ρ 0.26–0.56). In the stepwise multivariate regression model, the CESD, worsening dyspnoea and reflux scale were significantly associated with SLP-9 index. Conclusion. Sleep disturbances are common in SSc and are associated with worsening dyspnoea, depressed mood and severity of reflux symptoms. PMID:21324979

  1. PQScal (Power Quality Score Calculation for Distribution Systems with DER Integration)

    SciTech Connect

    2016-11-21

    Power Quality is of great importance to evaluate the “health” of a distribution system, especially when the distributed energy resource (DER) penetration becomes more significant. The individual components that make up power quality, such as voltage magnitude and unbalance, can be measured in simulations or in the field, however, a comprehensive method to incorporate all of these values into a single score doesn't exist. As a result, we propose a methodology to quantify the power quality health using the single number value, named as Power Quality Score (PQS). The PQS is dependent on six metrics that are developed based on both components that directly impact power quality and those are often reference in the context of power quality. These six metrics are named as System Average Voltage Magnitude Violation Index (SAVMVI), System Average Voltage Fluctuation Index (SAVFI), System Average Voltage Unbalance Index (SAVUI), System Control Device Operation Index (SCDOI), System Reactive Power Demand Index (SRPDI) and System Energy Loss Index (SELI). This software tool, PQScal, is developed based on this novel PQS methodology. Besides of traditional distribution systems, PQScal can also measure the power quality for distribution systems with various DER penetrations. PQScal has been tested on two utility distribution feeders with distinct model characteristics and its effectiveness has been proved. In sum, PQScal can help utilities or other parties to measure the power quality of distribution systems with DER integration easily and effectively.

  2. Achieving quality excellence at the Diablo Canyon Nuclear Power Plant

    SciTech Connect

    Skidmore, S.M.; Taggart, D.A.

    1988-01-01

    Quality assurance methods at the Diablo Canyon plant were transformed from the then typical industry practices that often alienated professional and technical people, as well as craftsmen and their foremen, to a cooperative method that allowed plant personnel to work together as a team. It has created an attitude to do it right the first time. The roles of quality professionals were expanded to include teaching and coaching to facilitate enhanced communication between and within functional organizations. This included regular presentations to managers and line personnel in an informal group participative atmosphere. These presentations have become widely known at the plant as quality awareness tailboard sessions. These presentations are intended to increase personnel sensitivity to the subject of quality and quality management. Economic achievement of excellence in quality is essential to remain competitive in today's marketplace. The proactive team-oriented approach of quality assurance achieves the bottom line of high quality with concurrently enhanced productivity and cost-effectiveness.

  3. Opportunities for Wind Power In Low- and Mid-Quality Resource Regions

    SciTech Connect

    Lantz, Eric; Mai, Trieu; Heimiller, Donna; Ho, Jonathan; Stehly, Tyler

    2016-05-25

    In this presentation for American Wind Energy Association (AWEA) WINDPOWER 2016 conference, the authors discuss wind power today in low and mid-quality resource regions, the anticipated role of wind power in the future electric sector, market potential in low and mid-quality resource regions, and anticipated innovations to capture that market potential.

  4. Effects of a Meditation Program on Nurses' Power and Quality of Life.

    PubMed

    Chang, Sun Ju; Kwak, Eun Young; Hahm, Bong-Jin; Seo, Se Hee; Lee, Da Woon; Jang, Sun Joo

    2016-07-01

    This study evaluated the effects of meditation programs on nurses' power and quality of life. In this study, Barrett's power theory derived from Rogers' unitary human being science was used as a theoretical framework. A randomized controlled design with 50 recruited and randomly allocated participants was used. The results demonstrated that the eight-week meditation program significantly improved nurses' power and quality of life. These results suggest that meditation has positive effects on power and quality of life. © The Author(s) 2016.

  5. Disturbance regime

    Treesearch

    F.N. Scatena; J.F. Blanco; K.H. Beard; R.B. Waide; A.E. Lugo; N. Brokaw; W.L. Silver; B.L. Haines; J.K. Zimmerman

    2012-01-01

    The Luquillo Mountains are affected by a wide array of environmental processes and distnrbances. Events that concurrently alter the environmental space of several different areas of the Luquillo Mountains occur every 2 to 5 years. Events such as hurricanes that cause widespread environmental modification occur once every 20 to 60 years. The most common disturbance-...

  6. Adaptive preheating duration control for low-power ambient air quality sensor networks.

    PubMed

    Baek, Yoonchul; Atiq, Mahin K; Kim, Hyung Seok

    2014-03-20

    Ceramic gas sensors used for measuring ambient air quality have features suitable for practical applications such as healthcare and air quality management, but have a major drawback-large power consumption to preheat the sensor for accurate measurements. In this paper; the adaptive preheating duration control (APC) method is proposed to reduce the power consumption of ambient air quality sensor networks. APC reduces the duration of unnecessary preheating, thereby alleviating power consumption. Furthermore, the APC can allow systems to meet user requirements such as accuracy and periodicity factor when detecting the concentration of a target gas. A performance evaluation of the power consumption of gas sensors is conducted with various user requirements and factors that affect the preheating duration of the gas sensor. This shows that the power consumption of the APC is lower than that of continuous power supply methods and constant power supply/cutoff methods.

  7. Adaptive Preheating Duration Control for Low-Power Ambient Air Quality Sensor Networks

    PubMed Central

    Baek, Yoonchul; Atiq, Mahin K.; Kim, Hyung Seok

    2014-01-01

    Ceramic gas sensors used for measuring ambient air quality have features suitable for practical applications such as healthcare and air quality management, but have a major drawback—large power consumption to preheat the sensor for accurate measurements. In this paper; the adaptive preheating duration control (APC) method is proposed to reduce the power consumption of ambient air quality sensor networks. APC reduces the duration of unnecessary preheating, thereby alleviating power consumption. Furthermore, the APC can allow systems to meet user requirements such as accuracy and periodicity factor when detecting the concentration of a target gas. A performance evaluation of the power consumption of gas sensors is conducted with various user requirements and factors that affect the preheating duration of the gas sensor. This shows that the power consumption of the APC is lower than that of continuous power supply methods and constant power supply/cutoff methods. PMID:24658619

  8. Reaction Wheel Disturbance Reduction Method Using Disturbance Measurement Table

    NASA Astrophysics Data System (ADS)

    Cheon, Dong-Ik; Jang, Eun-Jeong; Oh, Hwa-Suk

    2011-12-01

    Momentum changing actuators like reaction wheels and control moment gyros are generally used for spacecraft attitude control. This type of actuators produces force and torque disturbances. These disturbances must be reduced since they degrade the quality of spacecraft attitude control. Major disturbances are mainly due to static and dynamic imbalances. This paper gives attention to the reduction of the static and dynamic imbalance. Force/torque measurement system is used to measure the disturbance of the test reaction wheel. An identification method for the location and magnitude of the imbalance is suggested, and the corrections of the imbalance are performed using balancing method. Through balancing, the static and dynamic imbalance is remarkably reduced

  9. Adaptive neuro-fuzzy inference system to improve the power quality of a split shaft microturbine power generation system

    NASA Astrophysics Data System (ADS)

    Oğuz, Yüksel; Üstün, Seydi Vakkas; Yabanova, İsmail; Yumurtaci, Mehmet; Güney, İrfan

    2012-01-01

    This article presents design of adaptive neuro-fuzzy inference system (ANFIS) for the turbine speed control for purpose of improving the power quality of the power production system of a split shaft microturbine. To improve the operation performance of the microturbine power generation system (MTPGS) and to obtain the electrical output magnitudes in desired quality and value (terminal voltage, operation frequency, power drawn by consumer and production power), a controller depended on adaptive neuro-fuzzy inference system was designed. The MTPGS consists of the microturbine speed controller, a split shaft microturbine, cylindrical pole synchronous generator, excitation circuit and voltage regulator. Modeling of dynamic behavior of synchronous generator driver with a turbine and split shaft turbine was realized by using the Matlab/Simulink and SimPowerSystems in it. It is observed from the simulation results that with the microturbine speed control made with ANFIS, when the MTPGS is operated under various loading situations, the terminal voltage and frequency values of the system can be settled in desired operation values in a very short time without significant oscillation and electrical production power in desired quality can be obtained.

  10. Microgobius meeki as a potential bio-indicator of habitat disturbance in shallow estuarine areas: a useful tool for the assessment of estuarine quality.

    PubMed

    Reis-Filho, J A; Giarrizzo, T

    2016-07-01

    The relationships between changes in habitat quality (disturbed and undisturbed sites) and the population parameters (density, size distribution, reproductive activity and diet) of a goby Microgobius meeki were investigated in a tropical estuary to assess its value as an indicator of anthropogenic changes, predominantly the effects of sedimentation and mangrove removal in shallow estuarine areas. Fish sampling surveys were conducted bimonthly between June 2009 and May 2010 over the entire estuarine gradient of the Paraguaçu River estuary, located on the central Brazilian coast. A predictive model was developed to assess the population changes of this species in 10 other tropical estuaries with different dimensions, basin features and distinct levels of anthropogenic disturbance. General linear models were used to relate the population structure of M. meeki to sediment type, habitat type resulting from mangrove conservation status, anthropogenic pressure and environmental characteristics such as salinity, dissolved oxygen concentrations and temperature. Sediment type and the presence of mangrove forests were the most effective predictors of local variability in the population structure of M. meeki. Individuals with mature gonads and high rates of feeding activity were associated predominantly with undisturbed habitats. Estuaries and estuarine sectors with high levels of sedimentation in shallow marginal areas, anthropogenic pressure from domestic and industrial effluents, and evidence of mangrove deforestation yielded the lowest capture rates of both juvenile and adult M. meeki. Based on these findings, M. meeki is identified as a potential indicator of the consequences of anthropogenic disturbance in transitional waters. A simple, but efficient collection protocol, in which overt signs of distress can be promptly observed is proposed. Testing the generality of this approach across different systems might prove useful in a broader conservation biology context.

  11. Is glaucoma comprehension associated with psychological disturbance and vision-related quality of life for patients with glaucoma? A cross-sectional study

    PubMed Central

    Kong, Xiang Mei; Zhu, Wen Qing; Hong, Jia Xu; Sun, Xing Huai

    2014-01-01

    Objective To investigate whether understanding of glaucoma is associated with psychological disturbance and vision-related quality of life (QoL) in patients with glaucoma. Design A prospective, hospital-based, cross-sectional study. Setting Shanghai, China. Participants Five hundred patients with glaucoma were included in the study. Participants were asked to complete the glaucoma comprehension questionnaire, the Hospital Anxiety and Depression Scale (HADS) questionnaire, and the 25-item National Eye Institute Visual Functioning Questionnaire (NEI VFQ-25). Outcome measures Sociodemographic data and clinical data were collected. Multivariate adjusted linear regression analyses were performed to examine factors related to psychological disorder and QoL. The relationship between understanding of glaucoma and psychological status or QoL was analysed. Results The mean age of patients was 56.5±17.2 years, and the mean duration of glaucoma was 4.6±6.3 years. About half (54.2%) of the patients had primary open angle glaucoma, 37.2% had primary angle closure glaucoma, and 8.6% had secondary glaucoma. The total score and the subscores of knowledge of glaucoma, compliance and habits were all negatively correlated with the HADS-Depression and HADS scores. For NEI VFQ-25, the total comprehension score was positively related to general vision, near activity, distance activity, social function, colour vision and the composite score. Habits had a significant influence on both HADS-Depression and the composite score of NEI VFQ-25. Conclusions The level of understanding about glaucoma is an independent factor negatively associated with psychological disturbance and positively associated with QoL in patients with glaucoma. However, it is a subjective factor which can be regulated, so imparting knowledge about glaucoma and establishing appropriate habits might help patients alleviate psychological disturbance and enhance their QoL. PMID:24861547

  12. Positions, Power and Practice: Functionalist Approaches and Translation Quality Assessment.

    ERIC Educational Resources Information Center

    Honig, Hans G.

    1997-01-01

    Examines theoretical foundations and practical application of Translation Quality Assessment (TQA), particularly in translator training. Several approaches to translation are considered, especially the "functional" and "relevance" approaches. The need for TQA, several popular views on translation quality, and the issue of…

  13. High Quality Factor Resonators for Inductive Power Transfer Systems

    NASA Astrophysics Data System (ADS)

    Etemadrezaei, Mohammad

    In this dissertation, the Inductive Power Transfer (IPT) systems for multi-MHz frequency of operation are investigated, and new ideas for magnetic link inductive coils are presented. (Abstract shortened by ProQuest.).

  14. Power quality at electricity de France: Overview of research activities

    SciTech Connect

    Gambier, G.

    1995-06-01

    For a few years now, Electricite De France (EDF) has made the electricity quality one of its main stock arguments. This report describes a few concrete realizations and R&D projects currently in progress. The first part of the paper describes the QUALMETRE{trademark} device and the QUALISCOPE software aimed to measure the quality of voltage. Then emphasis is put on the QUALIMAT project which purpose is to assess the target levels of the quality of supply from physical measurements and subjective factors like the customer`s opinion. To tackle the worrying problem of harmonics upon the public networks, EDF has also engaged an important program described in the third part. Lastly, the paper depicts the EMERAUDE and RESEAU PLUS contracts which guarantee customers a level of quality of supply.

  15. Flywheel energy storage for end-use power quality. Final report

    SciTech Connect

    Schoenung, S.

    1998-11-01

    Flywheel energy storage systems are entering the power quality mitigation market. They address specifically events caused by voltage sags and momentary interruptions. They are ideal for customer end-use. This report describes the need and power quality applications for flywheel energy storage systems. It also presents the fundamentals of flywheel technology and how it operates in power quality applications. Different types of flywheel systems are discussed, including low-speed conventional approaches, and advanced high-speed systems. Product descriptions and specifications are provided.

  16. Efficacy of mometasone furoate nasal spray for nasal symptoms, quality of life, rhinitis-disturbed sleep, and nasal nitric oxide in patients with perennial allergic rhinitis.

    PubMed

    Yamada, Takechiyo; Yamamoto, Hideyuki; Kubo, Seita; Sakashita, Masafumi; Tokunaga, Takahiro; Susuki, Dai; Narita, Norihiko; Ogi, Kazuhiro; Kanno, Masafumi; Yamashita, Shinji; Terasawa, Yuko; Kayano, Yuichiro; Masada, Mikio; Fujieda, Shigeharu

    2012-01-01

    Intranasal corticosteroid therapy has exhibited effectiveness for improving nasal symptoms and quality of life (QOL) scores associated with seasonal allergic rhinitis. We prospectively investigated the efficacy of mometasone furoate nasal spray (MFNS) for improving the total nasal symptom score, QOL score, and sleep quality in subjects with perennial allergic rhinitis (PAR). Nasal airway conditions were also objectively assessed by measuring nasal nitric oxide (NO). Fifty-seven patients with PAR were randomized to MFNS or placebo for a 14-day, double-blind, crossover study. The subjects recorded their symptoms on nasal symptom forms and a visual analog scale. QOL and sleep quality were surveyed in accordance with the Japanese version of the Rhinoconjunctivitis Quality of Life Questionnaire (JRQLQ) and the Japanese version of the Epworth Sleepiness Scale. Nasal NO was measured during a single exhalation using a chemiluminescence analyzer. MFNS treatment achieved significant reductions versus placebo for total nasal symptoms (p < 0.001). There were significant decreases of the usual daily activity domain (p < 0.005), outdoor activities (p < 0.01), social function (p < 0.05), and the overall QOL score (p < 0.05) of JRQLQ with MFNS therapy versus placebo. A significant reduction of the sleepiness scale was also observed in the MFNS group with high sleep disturbance (p < 0.01). A significant decrease of nasal NO was found in the MFNS group (p < 0.01), especially among patients with severe nasal symptoms (p < 0.005). This prospective study indicated that MFNS therapy significantly improves nasal symptoms, QOL, sleep quality, and upper airway condition in Japanese subjects with PAR.

  17. Air quality modeling of geothermal power plants in complex terrain

    SciTech Connect

    Tesche, T.W.

    1982-10-01

    Commercial energy development at the Geysers KGRA, California--the world's largest producing geothermal field--is confronted with increasingly more stringent air quality impact assessment requirements for not only regulated pollutants (e.g., hydrogen sulfide and primary particulates) but also unregulated species including benzene, ammonia, arsenic, Radon/sup 222/, boron, and mercury. An integrated program of ambient aerometric monitoring, tracer diffusion experiments, cooling tower plume rise studies, and numerical air quality simulation modeling was conducted for this mountainous region to provide estimates of potential short term (i.e., about 1 hour) impacts attributable to development of the Geysers steam resource. A series of atmospheric tracer diffusion experiments, focusing on aerodynamic downwash, nocturnal drainage, fumigation, and limited vertical mixing were conducted to provide a basis for air quality model performance evaluation. Upper air meteorological measurements and cooling tower plume rise studies were performed to develop data useful in evaluating windfield and plume rise submodels.

  18. Development of an analytical tool to study power quality of AC power systems for large spacecraft

    NASA Technical Reports Server (NTRS)

    Kraft, L. Alan; Kankam, M. David

    1991-01-01

    A harmonic power flow program applicable to space power systems with sources of harmonic distortion is described. The algorithm is a modification of the Electric Power Research Institute's HARMFLO program which assumes a three phase, balanced, AC system with loads of harmonic distortion. The modified power flow program can be used with single phase, AC systems. Early results indicate that the required modifications and the models developed are quite adequate for the analysis of a 20 kHz testbed built by General Dynamics Corporation. This is demonstrated by the acceptable correlation of present results with published data. Although the results are not exact, the discrepancies are relatively small.

  19. Development of an analytical tool to study power quality of ac power systems for large spacecraft

    NASA Technical Reports Server (NTRS)

    Kraft, L. A.; Kankam, M. D.

    1991-01-01

    A harmonic power flow program applicable to space power systems with sources of harmonic distortion is described. The algorithm is a modification of Electric Power Research Institute's HARMFLO program which assumes a three-phase, balanced, ac system with loads of harmonic distortion. The modified power flow program can be used with single phase, ac systems. Early results indicate that the required modifications and the models developed are quite adequate for the analysis of a 20-kHz testbed built by General Dynamics Corporation. This is demonstrated by the acceptable correlation of the present results with published data. Although the results are not exact, the discrepancies are relatively small.

  20. Electrical Power Quality--What's behind the Outlet?

    ERIC Educational Resources Information Center

    Baird, William H.; Secrest, Jeffrey; Padgett, Clifford

    Although we may consider the power outlets in our homes to be nearly ideal voltage sources, a variety of influences in and around the home can cause departures from the nominal 60 Hz, 110-120 V root-mean-square (rms) of the North American grid. Even without instrumentation, we can see that a large motor starting from rest can be sufficient to…

  1. Hydrology and water quality of Powers Lake, southeastern Wisconsin

    USGS Publications Warehouse

    Field, S.J.

    1993-01-01

    The health of the lake was evaluated using Carlson's Trophic State Index and Vollenweider's model. Carlson's Trophic State Index showed that Powers Lake was moderately enriched and in the mesotrophic range. Comparison of guidelines from Vollenweider's model showed that the total phosphorus input for the study period and for an estimated average year would not cause eutrophic conditions.

  2. Mitochondrial Quality Control: Decommissioning Power Plants in Neurodegenerative Diseases

    PubMed Central

    Chakrabarti, Oishee

    2013-01-01

    The cell has an intricate quality control system to protect its mitochondria from oxidative stress. This surveillance system is multi-tiered and comprises molecules that are present inside the mitochondria, in the cytosol, and in other organelles like the nucleus and endoplasmic reticulum. These molecules cross talk with each other and protect the mitochondria from oxidative stress. Oxidative stress is a fundamental part of early disease pathogenesis of neurodegenerative diseases. These disorders also damage the cellular quality control machinery that protects the cell against oxidative stress. This exacerbates the oxidative damage and causes extensive neuronal cell death that is characteristic of neurodegeneration. PMID:24288463

  3. Mitochondrial quality control: decommissioning power plants in neurodegenerative diseases.

    PubMed

    Mukherjee, Rukmini; Chakrabarti, Oishee

    2013-01-01

    The cell has an intricate quality control system to protect its mitochondria from oxidative stress. This surveillance system is multi-tiered and comprises molecules that are present inside the mitochondria, in the cytosol, and in other organelles like the nucleus and endoplasmic reticulum. These molecules cross talk with each other and protect the mitochondria from oxidative stress. Oxidative stress is a fundamental part of early disease pathogenesis of neurodegenerative diseases. These disorders also damage the cellular quality control machinery that protects the cell against oxidative stress. This exacerbates the oxidative damage and causes extensive neuronal cell death that is characteristic of neurodegeneration.

  4. Power quality of wind turbines and their interaction with the grid

    SciTech Connect

    Gerdes, G.; Santjer, F.

    1995-12-31

    The interaction of wind turbines (WT) with the grid has an evident influence on the voltage of the grid. The loss of power quality is depending directly on the intensity of the interference related to the capacity of the grid. In near future a certificate for power quality will be claimed by German utilities. This certificate will demonstrate the quality of power generation of a WT with respects to harmonics, power peaks, power factor and flicker for normal operation as well as for extreme and switching operation conditions. In this paper we present examples of the measurements according to the guideline. We show the grid interactions occurring during the operation of different WTs and how they possibly could be diminished. In addition the interaction effects of single WTs and wind farms will be compared.

  5. Fractional power in the bucket, beam quality and M2

    NASA Astrophysics Data System (ADS)

    Basu, Santanu; Gutheinz, Lee M.

    2010-02-01

    This paper gives expressions to calculate the fraction of power, fPIB, from a given multimode gaussian laser beam that can be deposited within a bucket of radius, rT, on a target at a range, zT, using a focusing optic of diameter, Df. We relate the power in the bucket, fPIB, to the M2 parameter, both of which can be experimentally measured. In this paper, we have also presented relationships between these two parameters and BQ and Strehl, which have not been unambiguously defined for a multimode laser beam in the literature. We propose fPIB and M2 to be used as standard design parameters instead of BQ and Strehl for laser-target interaction tests with multimode laser beams from stable resonators.

  6. New wavelet indexes for the severity assessment of transient disturbances on low-voltage distribution systems

    NASA Astrophysics Data System (ADS)

    Riera-Ayala, Guillermo Miguel

    Power Quality is a relatively new research area of power engineering. Its main purpose is the analysis, classification and correction of power disturbances. There are many types of power disturbances. The two main types are: steady state disturbances (voltage distortion) and transient disturbances (impulses, sags, etc.). Sources for these disturbances can be found on both distribution and transmission networks. The analysis and classification of these disturbances involves the application of several signal processing tools, most of them in the frequency domain. The most common is the Continuous Fourier Transform (CFT). This method is widely used for the study of steady state voltage distortion. It allows the decomposition of distorted waveforms into harmonic components and the calculation of distortion indexes. The use of CFT is limited to steady state disturbances because of its infinite time mathematical composition. Transient disturbances are better analyzed using time domain methods. They are classified according to peak voltage, rise time, duration and energy content. Time domain methods are based on time differential equations and require large amounts of computer memory. This study uses One Dimensional Wavelet Decomposition to develop wavelet distortion indexes to classify transient disturbances. The new wavelet distortion indexes will be similar to the harmonic distortion indexes used for steady state voltage distortion. Peak and one cycle RMS values of reconstructed signals from different wavelet scales will be combined to calculate the indexes. These indexes will relate to the CBEMA (Computer Business Equipment Manufacturers Association) Susceptibility Chart and they will provide an idea of the severity of the transient disturbances. The main contribution to the field is that a single number will provide sufficient information on the severity of a transient disturbance. Wavelet decomposition is applied to a variety of transient disturbances. Real

  7. A Review of Distributed Control Techniques for Power Quality Improvement in Micro-grids

    NASA Astrophysics Data System (ADS)

    Zeeshan, Hafiz Muhammad Ali; Nisar, Fatima; Hassan, Ahmad

    2017-05-01

    Micro-grid is typically visualized as a small scale local power supply network dependent on distributed energy resources (DERs) that can operate simultaneously with grid as well as in standalone manner. The distributed generator of a micro-grid system is usually a converter-inverter type topology acting as a non-linear load, and injecting harmonics into the distribution feeder. Hence, the negative effects on power quality by the usage of distributed generation sources and components are clearly witnessed. In this paper, a review of distributed control approaches for power quality improvement is presented which encompasses harmonic compensation, loss mitigation and optimum power sharing in multi-source-load distributed power network. The decentralized subsystems for harmonic compensation and active-reactive power sharing accuracy have been analysed in detail. Results have been validated to be consistent with IEEE standards.

  8. Muscle power is an independent determinant of pain and quality of life in knee osteoarthritis

    USDA-ARS?s Scientific Manuscript database

    OBJECTIVE: This study examined the relationships between leg muscle strength, power, and perceived disease severity in subjects with knee osteoarthritis (OA) in order to determine whether dynamic leg extensor muscle power would be associated with pain and quality of life in knee OA. METHODS: Baseli...

  9. High-power 83 W holmium-doped silica fiber laser operating with high beam quality.

    PubMed

    Jackson, Stuart D; Sabella, Alex; Hemming, Alex; Bennetts, Shayne; Lancaster, David G

    2007-02-01

    A high-power 83 W cladding-pumped Tm3+-Ho3+-doped silica fiber laser is reported. Using bidirectional 793 nm diode pumping, a maximum slope efficiency of 42% was produced after a threshold launched pump power of 12 W was exceeded. The laser operated at wavelengths near 2105 nm with moderate beam quality, i.e., M2 approximately 1.5. Further power scaling of the fiber laser was limited by thermal failure of the fiber ends.

  10. High-power 83 W holmium-doped silica fiber laser operating with high beam quality

    NASA Astrophysics Data System (ADS)

    Jackson, Stuart D.; Sabella, Alex; Hemming, Alex; Bennetts, Shayne; Lancaster, David G.

    2007-02-01

    A high-power 83W cladding-pumped Tm3+-Ho3+-doped silica fiber laser is reported. Using bidirectional 793nm diode pumping, a maximum slope efficiency of 42% was produced after a threshold launched pump power of 12W was exceeded. The laser operated at wavelengths near 2105nm with moderate beam quality, i.e., M2˜1.5. Further power scaling of the fiber laser was limited by thermal failure of the fiber ends.

  11. Knowledge, Power and Meanings Shaping Quality Assurance in Higher Education: A Systemic Critique

    ERIC Educational Resources Information Center

    Houston, Don; Paewai, Shelley

    2013-01-01

    Internationally, quality assurance schemes persist despite long-standing dissatisfaction and critique of their impact and outcomes. Adopting a critical systems perspective, the article explores the relationships between the knowledge, power and meanings that stakeholder groups bring to the design and implementation of quality assurance systems.…

  12. Knowledge, Power and Meanings Shaping Quality Assurance in Higher Education: A Systemic Critique

    ERIC Educational Resources Information Center

    Houston, Don; Paewai, Shelley

    2013-01-01

    Internationally, quality assurance schemes persist despite long-standing dissatisfaction and critique of their impact and outcomes. Adopting a critical systems perspective, the article explores the relationships between the knowledge, power and meanings that stakeholder groups bring to the design and implementation of quality assurance systems.…

  13. Power conversion and quality of the Santa Clara 2 MW direct carbonate fuel cell demonstration plant

    SciTech Connect

    Skok, A.J.; Abueg, R.Z.; Schwartz, P.

    1996-12-31

    The Santa Clara Demonstration Project (SCDP) is the first application of a commercial-scale carbonate fuel cell power plant on a US electric utility system. It is also the largest fuel cell power plant ever operated in the United States. The 2MW plant, located in Santa Clara, California, utilizes carbonate fuel cell technology developed by Energy Research Corporation (ERC) of Danbury, Connecticut. The ultimate goal of a fuel cell power plant is to deliver usable power into an electrical distribution system. The power conversion sub-system does this for the Santa Clara Demonstration Plant. A description of this sub-system and its capabilities follows. The sub-system has demonstrated the capability to deliver real power, reactive power and to absorb reactive power on a utility grid. The sub-system can be operated in the same manner as a conventional rotating generator except with enhanced capabilities for reactive power. Measurements demonstrated the power quality from the plant in various operating modes was high quality utility grade power.

  14. Sleep disturbances in Parkinsonism.

    PubMed

    Askenasy, J J M

    2003-02-01

    The present article is meant to suggest an approach to the guidelines for the therapy of sleep disturbances in Parkinson's Disease (PD) patients.The factors affecting the quality of life in PD patients are depression, sleep disturbances and dependence. A large review of the literature on sleep disturbances in PD patients, provided the basis for the following classification of the sleep-arousal disturbances in PD patients. We suggest a model based on 3 steps in the treatment of sleep disturbances in PD patients. This model allowing the patient, the spouse or the caregiver a quiet sleep at night, may postpone the retirement and the institutionalization of the PD patient. I. Correct diagnosis of sleep disorders based on detailed anamnesis of the patient and of the spouse or of the caregiver. One week recording on a symptom diary (log) by the patient or the caregiver. Correct diagnosis of sleep disorders co morbidities. Selection of the most appropriate sleep test among: polysomnography (PSG), multiple sleep latency test (MSLT), multiple wake latency test (MWLT), Epworth Sleepiness Scale, actigraphy or video-PSG. II. The nonspecific therapeutic approach consists in: a) Checking the sleep effect on motor performance, is it beneficial, worse or neutral. b) Psycho-physical assistance. c) Dopaminergic adjustment is necessary owing to the progression of the nigrostriatal degeneration and the increased sensitivity of the terminals, which alter the normal modulator mechanisms of the motor centers in PD patients. Among the many neurotransmitters of the nigro-striatal pathway one can distinguish two with a major influence on REM and NonREM sleep. REM sleep corresponds to an increased cholinergic receptor activity and a decreased dopaminergic activity. This is the reason why REM sleep deprivation by suppressing cholinergic receptor activity ameliorates PD motor symptoms. L-Dopa and its agonists by suppressing cholinergic receptors suppress REM sleep. The permanent adjustment

  15. FUNDAMENTAL AREAS OF PHENOMENOLOGY (INCLUDING APPLICATIONS): Beam Quality and Power Scalability of Various Multicore Fiber Lasers

    NASA Astrophysics Data System (ADS)

    Zhou, Pu; Wang, Xiao-Lin; Ma, Yan-Xing; Ma, Hao-Tong; Xu, Xiao-Jun; Liu, Ze-Jin

    2009-08-01

    Beam quality and power scalability analyses for various multicore fiber lasers (MFL) are presented. In-phase complex amplitude and corresponding far-field intensity distribution of each type of MFL is calculated using the finite-difference time-domain method. It is revealed that the hexagonal ring-type MFL has the best performance in power handling and maintaining beam quality. Further calculation indicates that power encircled in the diffraction-bucket of L-core MFL scales with no more than 0.4L, which challenges the practical worthiness of fielding MFL with a large number of cores.

  16. Power Supplies for Space Systems Quality Assurance by Sandia Laboratories

    DOE R&D Accomplishments Database

    Hannigan, R. L.; Harnar, R. R.

    1976-07-01

    The Sandia Laboratories` participation in Quality Assurance programs for Radioisotopic Thermoelectric Generators which have been used in space systems over the past 10 years is summarized. Basic elements of this QA program are briefly described and recognition of assistance from other Sandia organizations is included. Descriptions of the various systems for which Sandia has had the QA responsibility are presented, including SNAP 19 (Nimbus, Pioneer, Viking), SNAP 27 (Apollo), Transit, Multi Hundred Watt (LES 8/9 and MJS), and a new program, High Performance Generator Mod 3. The outlook for Sandia participation in RTG programs for the next several years is noted.

  17. S-PRIME Thermionic Space Nuclear Power System Quality Assurance Program Plan

    SciTech Connect

    Jones, C.M.

    1992-09-23

    This Quality Assurance Program Plan (QAPP)describes how the Thermionic Space Nuclear Power System Design and Technology Demonstration Project addresses the Quality Assurance requirements delineated in DOE Order 5700.6C and the Thermionic Program Management Plan 214PMP000001. The Quality Assurance Program is based on the following fundamental principles, which Rocketdyne endorses and the QA Project Manager and Program Manager shall enforce: Quality Achievement is a continuing responsibility of line organization at all levels; the Quality Assurance organization through the effective overview of work, gives additional assurance that specified requirements are met; risk is the fundamental consideration in determining to what extent the Quality Assurance Plan should be applied to items and processes; action is based on facts and analysis, customer driven quality, strong quality leadership and continuous improvement.

  18. MATLAB Simulation of UPQC for Power Quality Mitigation Using an Ant Colony Based Fuzzy Control Technique.

    PubMed

    Kumarasabapathy, N; Manoharan, P S

    2015-01-01

    This paper proposes a fuzzy logic based new control scheme for the Unified Power Quality Conditioner (UPQC) for minimizing the voltage sag and total harmonic distortion in the distribution system consequently to improve the power quality. UPQC is a recent power electronic module which guarantees better power quality mitigation as it has both series-active and shunt-active power filters (APFs). The fuzzy logic controller has recently attracted a great deal of attention and possesses conceptually the quality of the simplicity by tackling complex systems with vagueness and ambiguity. In this research, the fuzzy logic controller is utilized for the generation of reference signal controlling the UPQC. To enable this, a systematic approach for creating the fuzzy membership functions is carried out by using an ant colony optimization technique for optimal fuzzy logic control. An exhaustive simulation study using the MATLAB/Simulink is carried out to investigate and demonstrate the performance of the proposed fuzzy logic controller and the simulation results are compared with the PI controller in terms of its performance in improving the power quality by minimizing the voltage sag and total harmonic distortion.

  19. A design of wireless sensor networks for a power quality monitoring system.

    PubMed

    Lim, Yujin; Kim, Hak-Man; Kang, Sanggil

    2010-01-01

    Power grids deal with the business of generation, transmission, and distribution of electric power. Recently, interest in power quality in electrical distribution systems has increased rapidly. In Korea, the communication network to deliver voltage, current, and temperature measurements gathered from pole transformers to remote monitoring centers employs cellular mobile technology. Due to high cost of the cellular mobile technology, power quality monitoring measurements are limited and data gathering intervals are large. This causes difficulties in providing the power quality monitoring service. To alleviate the problems, in this paper we present a communication infrastructure to provide low cost, reliable data delivery. The communication infrastructure consists of wired connections between substations and monitoring centers, and wireless connections between pole transformers and substations. For the wireless connection, we employ a wireless sensor network and design its corresponding data forwarding protocol to improve the quality of data delivery. For the design, we adopt a tree-based data forwarding protocol in order to customize the distribution pattern of the power quality information. We verify the performance of the proposed data forwarding protocol quantitatively using the NS-2 network simulator.

  20. A Design of Wireless Sensor Networks for a Power Quality Monitoring System

    PubMed Central

    Lim, Yujin; Kim, Hak-Man; Kang, Sanggil

    2010-01-01

    Power grids deal with the business of generation, transmission, and distribution of electric power. Recently, interest in power quality in electrical distribution systems has increased rapidly. In Korea, the communication network to deliver voltage, current, and temperature measurements gathered from pole transformers to remote monitoring centers employs cellular mobile technology. Due to high cost of the cellular mobile technology, power quality monitoring measurements are limited and data gathering intervals are large. This causes difficulties in providing the power quality monitoring service. To alleviate the problems, in this paper we present a communication infrastructure to provide low cost, reliable data delivery. The communication infrastructure consists of wired connections between substations and monitoring centers, and wireless connections between pole transformers and substations. For the wireless connection, we employ a wireless sensor network and design its corresponding data forwarding protocol to improve the quality of data delivery. For the design, we adopt a tree-based data forwarding protocol in order to customize the distribution pattern of the power quality information. We verify the performance of the proposed data forwarding protocol quantitatively using the NS-2 network simulator. PMID:22163436

  1. MATLAB Simulation of UPQC for Power Quality Mitigation Using an Ant Colony Based Fuzzy Control Technique

    PubMed Central

    Kumarasabapathy, N.; Manoharan, P. S.

    2015-01-01

    This paper proposes a fuzzy logic based new control scheme for the Unified Power Quality Conditioner (UPQC) for minimizing the voltage sag and total harmonic distortion in the distribution system consequently to improve the power quality. UPQC is a recent power electronic module which guarantees better power quality mitigation as it has both series-active and shunt-active power filters (APFs). The fuzzy logic controller has recently attracted a great deal of attention and possesses conceptually the quality of the simplicity by tackling complex systems with vagueness and ambiguity. In this research, the fuzzy logic controller is utilized for the generation of reference signal controlling the UPQC. To enable this, a systematic approach for creating the fuzzy membership functions is carried out by using an ant colony optimization technique for optimal fuzzy logic control. An exhaustive simulation study using the MATLAB/Simulink is carried out to investigate and demonstrate the performance of the proposed fuzzy logic controller and the simulation results are compared with the PI controller in terms of its performance in improving the power quality by minimizing the voltage sag and total harmonic distortion. PMID:26504895

  2. Quality application to space nuclear power (SP-100)

    SciTech Connect

    Caplinger, W.H.

    1987-09-01

    Westinghouse Hanford Company (WHC) was selected by DOE as the preferred site to install and conduct operational, performance, and reliability tests on the ground-based prototype of the space reactor. These tests will be conducted with the reactor in a large vacuum chamber to simulate the space environment. A containment vessel system from the decommissioned Plutonium Recycle Test Reactor will house the chamber and provide appropriate safeguards. The reactor will generate 2.5-MW thermal energy from uranium nitride fuel clad in a Nb-1% Zr alloy and will use lithium as the primary coolant. The Ground Engineering System (GES) phase of the SP-100 is administered by DOE-HQ through DOE-SAN with ANSI/ASME NQA-1 forming the basis for the Quality Assurance Requirements. All participants in the GES program, which includes seven Federal Laboratories and several private contactor, will develop programs to implement the GES Quality and Reliability Assurance Program Plan (Q and RAP). WHC developed a sub-tier Q and RAP for our activities based on existing procedures. The laboratory is committed to and has been implementing NQA-1 since 1979. As a result, procedures that satisfy the 18 NQA-1 criteria are in place. These are familiar to and understood by the performing personnel at WHC. The narrative for each criterion is a simple description of the selected methodology. WHC, Q and AP is, then, a road map to the implementing procedures. 6 refs.

  3. An Improved Power Quality Based Sheppard-Taylor Converter Fed BLDC Motor Drive

    NASA Astrophysics Data System (ADS)

    Singh, Bhim; Bist, Vashist

    2015-12-01

    This paper deals with the design and analysis of a power factor correction based Sheppard-Taylor converter fed brushless dc motor (BLDCM) drive. The speed of the BLDCM is controlled by adjusting the dc link voltage of the voltage source inverter (VSI) feeding BLDCM. Moreover, a low frequency switching of the VSI is used for electronically commutating the BLDCM for reduced switching losses. The Sheppard-Taylor converter is designed to operate in continuous conduction mode to achieve an improved power quality at the ac mains for a wide range of speed control and supply voltage variation. The BLDCM drive is designed and its performance is simulated in a MATLAB/Simulink environment to achieve the power quality indices within the limits of the international power quality standard IEC-61000-3-2.

  4. Research on improvement of power quality of Micro - grid based on SVG pulse load

    NASA Astrophysics Data System (ADS)

    Lv, Chuang; Xie, Pu

    2017-05-01

    Pulse load will make the micro-grid public bus power to produce a high peak pulse due to its cyclical pulsation characteristics,, and make the micro-grid voltage fluctuations, frequency fluctuations, voltage and current distortion, power factor reduction and other adverse effects. In order to suppress the adverse effects of the pulse load on the microgrid and improve the power quality of the microgrid, this paper established the SVG simulation model in Matlab / Simulink environment, the superiority of SVG is verified by comparing the improvement of power quality before and after adding the SVG to microgrid system. The results show that the SVG model can suppress the adverse effects effectively of the pulse load on the microgrid, which is of great value and significance to the reactive power compensation and harmonic suppression of the microgrid.

  5. 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.

  6. Gait Variability Related to Muscle Quality and Muscle Power Output in Frail Nonagenarian Older Adults.

    PubMed

    Martinikorena, Ion; Martínez-Ramírez, Alicia; Gómez, Marisol; Lecumberri, Pablo; Casas-Herrero, Alvaro; Cadore, Eduardo L; Millor, Nora; Zambom-Ferraresi, Fabricio; Idoate, Fernando; Izquierdo, Mikel

    2016-02-01

    Frailty has become the center of attention of basic, clinical, and demographic research because of its incidence level and the gravity of adverse outcomes with age. Moreover, with advanced age, motor variability increases, particularly in gait. Muscle quality and muscle power seem to be closely associated with performance on functional tests in frail populations. Insight into the relationships among muscle power, muscle quality, and functional capacity could improve the quality of life in this population. In this study, the relationship between the quality of the muscle mass and muscle strength with gait performance in a frail population was examined. Twenty-two institutionalized frail elderly individuals (93.1 ± 3.6) participated in this study. Muscle quality was measured by segmenting areas of high- and low-density fibers as observed in computed tomography images. The assessed functional outcomes were leg strength and power, velocity of gait, and kinematic gait parameters obtained from a tri-axial inertial sensor. Our results showed that a greater number of high-density fibers, specifically those of the quadriceps femoris muscle, were associated with better gait performance in terms of step time variability, regularity, and symmetry. Additionally, gait variability was associated with muscle power. In contrast, no significant relationship was observed between gait velocity and either muscle quality or muscle power. Gait pattern disorders could be explained by a deterioration of the lower limb muscles. It is known that an impaired gait is an important predictor of falls in older populations; thus, the loss of muscle quality and power could underlie the impairments in motor control and balance that lead to falls and adverse outcomes. Copyright © 2016 AMDA – The Society for Post-Acute and Long-Term Care Medicine. Published by Elsevier Inc. All rights reserved.

  7. Effect of intermittent aerobic exercise on sleep quality and sleep disturbances in patients with rheumatoid arthritis – design of a randomized controlled trial

    PubMed Central

    2014-01-01

    Background Poor sleep is prevalent in patients with systemic inflammatory disorders, including rheumatoid arthritis, and, in addition to fatigue, pain, depression and inflammation, is associated with an increased risk of co-morbidity and all-cause mortality. Whereas non-pharmacological interventions in patients with rheumatoid arthritis have been shown to reduce pain and fatigue, no randomized controlled trials have examined the effect of non-pharmacological interventions on improvement of sleep in patients with rheumatoid arthritis. The aim of this trial was to evaluate the efficacy of an intermittent aerobic exercise intervention on sleep, assessed both objectively and subjectively in patients with rheumatoid arthritis. Methods/design A randomized controlled trial including 44 patients with rheumatoid arthritis randomly assigned to an exercise training intervention or to a control group. The intervention consists of 18 session intermittent aerobic exercise training on a bicycle ergometer three times a week. Patients are evaluated according to objective changes in sleep as measured by polysomnography (primary outcome). Secondary outcomes include changes in subjective sleep quality and sleep disturbances, fatigue, pain, depressive symptoms, physical function, health-related quality of life and cardiorespiratory fitness. Discussion This trial will provide evidence of the effect of intermittent aerobic exercise on the improvement of sleep in patients with rheumatoid arthritis, which is considered important in promotion of health and well-being. As such, the trial meets a currently unmet need for the provision of non-pharmacological treatment initiatives of poor sleep in patients with rheumatoid arthritis. Trial registration ClinicalTrials.gov Identifier: NCT01966835 PMID:24559487

  8. Simulation of the wavefront distortion and beam quality for a high-power zigzag slab laser

    NASA Astrophysics Data System (ADS)

    Shin, Jae Sung; Cha, Yong-Ho; Cha, Byung Heon; Lee, Hyeon Cheor; Kim, Hyun Tae; Lee, Jung Hwan

    2016-12-01

    A simulation method of the beam quality for a high-power zigzag slab laser has been developed. This method can predict the wavefront distortion and beam quality for various optical arrangements and optimize the design effectively. A Nd:YAG zigzag slab laser amplifier was designed as an application. The optimized design shows a beam quality of 1.20 corresponding to the minimized wavefront distortion with a peak-to-valley of 0.568 μm and root mean square of 0.115 μm even under high-power operation with a total pump power of 14 kW. Although there are some effects other than the optical design error that incur wavefront distortions, this method can help to determine the first optical design of the zigzag slab laser without the need for many experimental studies.

  9. High power far-infrared optical parametric oscillator with high beam quality

    NASA Astrophysics Data System (ADS)

    Qian, Chuan-Peng; Shen, Ying-Jie; Dai, Tong-Yu; Duan, Xiao-Ming; Yao, Bao-Quan

    2016-11-01

    A high power ZnGeP2 (ZGP) optical parametric oscillator (OPO) with good beam quality pumped by a Q-switched Ho:YAG laser was demonstrated. The maximum output power of the ZGP OPO with a four-mirror ring cavity was about 5.04 W around 8.1 μm with 83.9 W Ho incident pump power, corresponding to a slope efficiency of 9.2 %. The ZGP OPO produced 36.0 ns far-IR pulse laser in the 8.0-8.3 μm spectral regions. The beam quality was measured to be M2 1.6 at the highest output power.

  10. Adaptive neuro-fuzzy and expert systems for power quality analysis and prediction of abnormal operation

    NASA Astrophysics Data System (ADS)

    Ibrahim, Wael Refaat Anis

    The present research involves the development of several fuzzy expert systems for power quality analysis and diagnosis. Intelligent systems for the prediction of abnormal system operation were also developed. The performance of all intelligent modules developed was either enhanced or completely produced through adaptive fuzzy learning techniques. Neuro-fuzzy learning is the main adaptive technique utilized. The work presents a novel approach to the interpretation of power quality from the perspective of the continuous operation of a single system. The research includes an extensive literature review pertaining to the applications of intelligent systems to power quality analysis. Basic definitions and signature events related to power quality are introduced. In addition, detailed discussions of various artificial intelligence paradigms as well as wavelet theory are included. A fuzzy-based intelligent system capable of identifying normal from abnormal operation for a given system was developed. Adaptive neuro-fuzzy learning was applied to enhance its performance. A group of fuzzy expert systems that could perform full operational diagnosis were also developed successfully. The developed systems were applied to the operational diagnosis of 3-phase induction motors and rectifier bridges. A novel approach for learning power quality waveforms and trends was developed. The technique, which is adaptive neuro fuzzy-based, learned, compressed, and stored the waveform data. The new technique was successfully tested using a wide variety of power quality signature waveforms, and using real site data. The trend-learning technique was incorporated into a fuzzy expert system that was designed to predict abnormal operation of a monitored system. The intelligent system learns and stores, in compressed format, trends leading to abnormal operation. The system then compares incoming data to the retained trends continuously. If the incoming data matches any of the learned trends, an

  11. Muscle power is an independent determinant of pain and quality of life in knee osteoarthritis

    PubMed Central

    Reid, Kieran F.; Price, Lori Lyn; Harvey, William F.; Driban, Jeffrey B.; Hau, Cynthia; Fielding, Roger A.; Wang, Chenchen

    2015-01-01

    Objectives We examined the relationships between lower extremity muscle strength, power and perceived disease severity in participants with knee osteoarthritis (OA). We hypothesized that dynamic leg extensor muscle power would be associated with pain and quality of life in knee OA. Methods We used baseline data from a randomized controlled trial in 190 participants with knee OA (age: 60.2 ± 10.4 yrs; BMI: 32.7 ± 7.2 kg/m2). Knee pain was measured using the Western Ontario and McMaster Osteoarthritis Index and health-related quality of life using the Short Form 36 (SF-36). One-repetition maximum (1RM) strength was assessed using the bilateral leg press and peak muscle power was measured during 5 maximum voluntary velocity repetitions at 40% and 70% of 1RM. Results In univariate analysis, greater muscle power was significantly associated with pain (r = -0.17, P < 0.02). It was also significantly and positively associated with SF-36 physical component scores (PCS) (r = 0.16, P < 0.05). After adjusting for multiple covariates, muscle power was a significant independent predictor of pain (P ≤ 0.05) and PCS (P ≤ 0.04). However, strength was not an independent determinant of pain or quality of life (P ≥ 0.06). Conclusions Muscle power is an independent determinant of pain and quality of life in knee OA. Compared to strength, muscle power may be a more clinically important measure of muscle function within this population. New trials to systematically examine the impact of muscle power training interventions on disease severity in knee OA are particularly warranted. PMID:26315282

  12. Muscle Power Is an Independent Determinant of Pain and Quality of Life in Knee Osteoarthritis.

    PubMed

    Reid, Kieran F; Price, Lori Lyn; Harvey, William F; Driban, Jeffrey B; Hau, Cynthia; Fielding, Roger A; Wang, Chenchen

    2015-12-01

    This study examined the relationships between leg muscle strength, power, and perceived disease severity in subjects with knee osteoarthritis (OA) in order to determine whether dynamic leg extensor muscle power would be associated with pain and quality of life in knee OA. Baseline data on 190 subjects with knee OA (mean ± SD age 60.2 ± 10.4 years, body mass index 32.7 ± 7.2 kg/m(2) ) were obtained from a randomized controlled trial. Knee pain was measured using the Western Ontario and McMaster Universities Osteoarthritis Index, and health-related quality of life was assessed using the Short Form 36 (SF-36). One-repetition maximum (1RM) strength was assessed using the bilateral leg press, and peak muscle power was measured during 5 maximum voluntary velocity repetitions at 40% and 70% of 1RM. In univariate analysis, greater muscle power was significantly associated with pain (r = -0.17, P < 0.02) and also significantly and positively associated with SF-36 physical component summary (PCS) scores (r = 0.16, P < 0.05). After adjustment for multiple covariates, muscle power was a significant independent predictor of pain (P ≤ 0.05) and PCS scores (P ≤ 0.04). However, muscle strength was not an independent determinant of pain or quality of life (P ≥ 0.06). Muscle power is an independent determinant of pain and quality of life in knee OA. Compared to strength, muscle power may be a more clinically important measure of muscle function within this population. New trials to systematically examine the impact of muscle power training interventions on disease severity in knee OA are particularly warranted. © 2015, American College of Rheumatology.

  13. A Novel Multiobjective Control of DVR to Enhance Power Quality of Sensitive Load.

    PubMed

    Pandu, Sathish Babu; Nagappan, Kamaraj

    2015-01-01

    The Dynamic Voltage Restorer (DVR) is one of the fast, flexible, and cost effective solutions available in compensating the voltage-related power quality problems in power distribution systems. In this paper is discussed how power quality enhancement of sensitive load is achieved by applying three versions of Autonomous Group Particle Swarm Optimization like AGPSO1, AGPSO2, and AGPSO3 for tuning the Proportional-Integral DVR controller under balanced and nonlinear load conditions. A novel multiobjective function is formulated to express the control performance of the system, which is quantified using three power quality indices such as Total Harmonic Distortion (THD), voltage sag index, and RMS voltage variation. The obtained results are compared with the Proportional-Integral (PI) controller tuned by Ziegler-Nichols (ZN) method and also by Simple Particle Swarm Optimization based PI controlled DVR. The proposed methodology has improved the performance in terms of the considered power quality indices and the simulation has been carried out in MATLAB/Simulink environment.

  14. International water and steam quality standards on thermal power plants at all-volatile treatment

    NASA Astrophysics Data System (ADS)

    Petrova, T. I.; Orlov, K. A.; Dooley, R. B.

    2016-12-01

    One of the methods for the improvement of reliability and efficiency of the equipment at heat power plants is the decrease in the rate of corrosion of structural materials and sedimentation in water/steam circuit. These processes can be reduced to minimum by using the water with low impurity content and coolant treatment. For many years, water and steam quality standards were developed in various countries (United States, Germany, Japan, etc.) for specific types of equipment. The International Association for the Properties of Water and Steam (IAPWS), which brings together specialists from 21 countries, developed the water and steam quality standards for various types of power equipment based on theoretical studies and long-term operating experience of power equipment. Recently, various water-chemistry conditions are applied on heatpower equipment including conventional boilers and HRSGs with combined cycle power plants (Combined Cycle Power Plants (CCPP)). In paper, the maintenance conditions of water chemistry with ammonia or volatile amine dosing are described: reducing AVT(R), oxidizing AVT(O), and oxygen OT. Each of them is provided by the water and steam quality standards and recommendations are given on their maintenance under various operation conditions. It is noted that the quality control of heat carrier must be carried out with a particular care on the HPPs with combined cycle gas turbine units, where frequent starts and halts are performed.

  15. A Novel Multiobjective Control of DVR to Enhance Power Quality of Sensitive Load

    PubMed Central

    Pandu, Sathish Babu; Nagappan, Kamaraj

    2015-01-01

    The Dynamic Voltage Restorer (DVR) is one of the fast, flexible, and cost effective solutions available in compensating the voltage-related power quality problems in power distribution systems. In this paper is discussed how power quality enhancement of sensitive load is achieved by applying three versions of Autonomous Group Particle Swarm Optimization like AGPSO1, AGPSO2, and AGPSO3 for tuning the Proportional-Integral DVR controller under balanced and nonlinear load conditions. A novel multiobjective function is formulated to express the control performance of the system, which is quantified using three power quality indices such as Total Harmonic Distortion (THD), voltage sag index, and RMS voltage variation. The obtained results are compared with the Proportional-Integral (PI) controller tuned by Ziegler-Nichols (ZN) method and also by Simple Particle Swarm Optimization based PI controlled DVR. The proposed methodology has improved the performance in terms of the considered power quality indices and the simulation has been carried out in MATLAB/Simulink environment. PMID:26613100

  16. A reliable data delivery mechanism for grid power quality using neural networks in wireless sensor networks.

    PubMed

    Lim, Yujin; Kim, Hak-Man; Kang, Sanggil

    2010-01-01

    Power grids deal with the business of generation, transmission, and distribution of electric power. Current systems monitor basic electrical quantities such as voltage and current from major pole transformers using their temperature. We improve the current systems in order to gather and deliver the information of power qualities such as harmonics, voltage sags, and voltage swells. In the system, data delivery is not guaranteed for the case that a node is lost or the network is congested, because the system has in-line and multi-hop architecture. In this paper, we propose a reliable data delivery mechanism by modeling an optimal data delivery function by employing the neural network concept.

  17. Total Quality Education: Profiles of Schools That Demonstrate the Power of Deming's Management Principles.

    ERIC Educational Resources Information Center

    Schmoker, Michael J.; Wilson, Richard B.

    This book presents profiles of schools that have demonstrated the power of Deming's Total Quality Management (TQM) principles. It describes schools that have successfully applied those strategies for change. The book explores what public education needs most--a compelling but flexible action plan for improvement. Chapter 1 offers a rationale for…

  18. An Improved Power Quality BIBRED Converter-Based VSI-Fed BLDC Motor Drive

    NASA Astrophysics Data System (ADS)

    Singh, Bhim; Bist, Vashist

    2014-01-01

    This paper presents an IHQRR (integrated high-quality rectifier regulator) BIBRED (boost integrated buck rectifier energy storage DC-DC) converter-based VSI (voltage source inverter)-fed BLDC (brushless DC) motor drive. The speed control of BLDC motor is achieved by controlling the DC link voltage of the VSI using a single voltage sensor. This allows VSI to operate in fundamental frequency switching mode for electronic commutation of BLDC motor which reduces the switching losses due to high-frequency switching used in conventional approach of PWM (pulse width modulation)-based VSI-fed BLDC motor drive. A BIBRED converter is operated in a dual-DCM (discontinuous conduction mode) thus using a voltage follower approach for PFC (power factor correction) and DC link voltage control. The performance of the proposed drive is evaluated for improved power quality over a wide range of speed control and supply voltage variation for demonstrating the behavior of proposed drive. The power quality indices thus obtained are within the recommended limits by international PQ (power quality) standards such as IEC 61000-3-2.

  19. Evaluation of conventional electric power generating industry quality assurance and reliability practices

    SciTech Connect

    Anderson, R.T.; Lauffenburger, H.A.

    1981-03-01

    The techniques and practices utilized in an allied industry (electric power generation) that might serve as a baseline for formulating Quality Assurance and Reliability (QA and R) procedures for photovoltaic solar energy systems were studied. The study results provide direct near-term input for establishing validation methods as part of the SERI performance criteria and test standards development task.

  20. Total Quality Education: Profiles of Schools That Demonstrate the Power of Deming's Management Principles.

    ERIC Educational Resources Information Center

    Schmoker, Michael J.; Wilson, Richard B.

    This book presents profiles of schools that have demonstrated the power of Deming's Total Quality Management (TQM) principles. It describes schools that have successfully applied those strategies for change. The book explores what public education needs most--a compelling but flexible action plan for improvement. Chapter 1 offers a rationale for…

  1. Assessing I-Grid(TM) web-based monitoring for power quality and reliability benchmarking

    SciTech Connect

    Divan, Deepak; Brumsickle, William; Eto, Joseph

    2003-04-30

    This paper presents preliminary findings from DOEs pilot program. The results show how a web-based monitoring system can form the basis for aggregation of data and correlation and benchmarking across broad geographical lines. A longer report describes additional findings from the pilot, including impacts of power quality and reliability on customers operations [Divan, Brumsickle, Eto 2003].

  2. Cost and Quality Management: Making fossil power and plants more competitive: Phase 1

    SciTech Connect

    McQueen, R.S. . Center for Productivity and Mfg. Engineering)

    1992-05-01

    Cost and Quality Management theory is helping to make US corporations profitable again. Summarizing Phase 1 of a three-phase study, this report defines how Cost and Quality Management (also called Total Quality Management) relates to power production plants, the barriers standing in the way, and the concepts needed to overcome them. Major barriers include resistance to change, sparse efforts to grow employee initiative and self-esteem, a lack of understanding the importance of internal customers, and traditional management practices as represented by the top-to-bottom organization chart. Breakthrough concepts include a commitment to making and sustaining quality-based changes, realizing the potential of human assets, focusing on satisfying internal as well as external customers, and treating work as a process that crosses departments. The report ends by describing five other ongoing EPRI projects designed to help utility executives change from a traditional management style to Cost and Quality Management.

  3. Cost and Quality Management: Making fossil power and plants more competitive: Phase 1. Final report

    SciTech Connect

    McQueen, R.S.

    1992-05-01

    Cost and Quality Management theory is helping to make US corporations profitable again. Summarizing Phase 1 of a three-phase study, this report defines how Cost and Quality Management (also called Total Quality Management) relates to power production plants, the barriers standing in the way, and the concepts needed to overcome them. Major barriers include resistance to change, sparse efforts to grow employee initiative and self-esteem, a lack of understanding the importance of internal customers, and traditional management practices as represented by the top-to-bottom organization chart. Breakthrough concepts include a commitment to making and sustaining quality-based changes, realizing the potential of human assets, focusing on satisfying internal as well as external customers, and treating work as a process that crosses departments. The report ends by describing five other ongoing EPRI projects designed to help utility executives change from a traditional management style to Cost and Quality Management.

  4. Using employer purchasing power to improve the quality of perinatal care.

    PubMed

    Castles, A G; Milstein, A; Damberg, C L

    1999-01-01

    Large employers have become increasingly involved in helping to set the agenda for quality measurement and improvement. Moreover, they are beginning to hold health care organizations accountable for their performance through marketplace incentives, including the public reporting of comparative quality data and the linkage of reimbursement to performance on quality measures. The Pacific Business Group on Health (PBGH) is an employer coalition that has been prominent in establishing models for collaborative quality measurement and improvement in the California marketplace. PBGH's involvement in quality stems from an environment in which purchasers were faced with high health care costs, yet virtually no information with which to assess the value their employees received from that care. Research indicating widespread variation in performance across health care organizations and seemingly limited oversight for quality of care within the industry has further motivated purchasers' efforts to better understand the quality of care being delivered to their em-ployees. Using the purchasing power of employers representing 2.5-million covered lives, PBGH endeavors to encourage the transition of the health care marketplace from one that competes solely on price to one that competes on price and quality. This entails collaborating with the health care industry to develop and publicly report valid performance data for use by both large employers and consumers of health care services. It also includes communicating to the marketplace purchasers' commitment to making purchasing decisions based on quality as well as cost. PBGH efforts to measure, report, and improve quality have been demonstrated by several undertakings in the perinatal care arena, including research to assess cesarean section rates and newborn readmission rates across California hospitals.employer coalition, purchaser, quality measurement, quality improvement, report cards, perinatal quality of care.

  5. Analysis of apple beverages treated with high power ultrasound - a quality function deployment approach.

    PubMed

    Režek Jambrak, Anet; Šimunek, Marina; Grbeš, Franjo; Mandura, Ana; Djekic, Ilija

    2017-10-05

    The objective of this paper was to demonstrate application of quality function deployment in analysing effects of high power ultrasound on quality properties of apple juices and nectars. In order to develop a quality function deployment model, joint with instrumental analysis of treated samples, a field survey was performed to identify consumer preferences towards quality characteristics of juices/nectar. Based on field research, three most important characteristics were 'taste' and 'aroma' with 28.5% of relative absolute weight importance, followed by 'odour' (16.9%). Quality function deployment model showed that the top three 'Quality Scores' for apple juice were treatments with amplitude 90 µm, 9 min treatment time and the sample temperature of 40 °C; 60 µm/9 min/60 °C and 90 µm/6 min/40 °C. For nectars, top three were treatments 120 µm/9 min/20 °C; 60 µm/9 min/60 °C and A2.16 60 µm/9 min/20 °C. This type of quality models enables a more complex measure of large scale of different quality parameters. Its simplicity should be understood as its practical advantage and as such, this tool can be a part of design quality when using novel preservation technologies. This article is protected by copyright. All rights reserved.

  6. Impact of power ultrasound on chemical and physicochemical quality indicators of strawberries dried by convection.

    PubMed

    Gamboa-Santos, Juliana; Montilla, Antonia; Soria, Ana C; Cárcel, Juan A; García-Pérez, José V; Villamiel, Mar

    2014-10-15

    A study on the quality parameters of strawberries dehydrated by convection assisted by power ultrasound (US) at 40-70°C and 30 and 60W has been carried out for the first time. In general, the quality of US-treated samples was higher than that of commercial samples. Even under the most severe conditions used (US at 70°C and 60W), high values of vitamin C retention (>65%) and scarce advance of Maillard reaction (2-furoylmethyl derivatives of Lys and Arg<90mg 100g(-1) protein) were observed. Rehydration ratio was not affected by the power applied and the obtained values were similar to those of convectively-treated samples. According to the results here presented, US is a suitable example of an emerging and environmentally friendly technology that accelerates convective drying, allowing the obtainment of dried strawberries with premium quality. Copyright © 2014 Elsevier Ltd. All rights reserved.

  7. 300 Area Disturbance Report

    SciTech Connect

    LL Hale; MK Wright; NA Cadoret

    1999-01-07

    The objective of this study was to define areas of previous disturbance in the 300 Area of the U.S. Department of Energy (DOE) Hanford Site to eliminate these areas from the cultural resource review process, reduce cultural resource monitoring costs, and allow cultural resource specialists to focus on areas where subsurface disturbance is minimal or nonexistent. Research into available sources suggests that impacts from excavations have been significant wherever the following construction activities have occurred: building basements and pits, waste ponds, burial grounds, trenches, installation of subsurface pipelines, power poles, water hydrants, and well construction. Beyond the areas just mentioned, substrates in the' 300 Area consist of a complex, multidimen- sional mosaic composed of undisturbed stratigraphy, backfill, and disturbed sediments; Four Geographic Information System (GIS) maps were created to display known areas of disturbance in the 300 Area. These maps contain information gleaned from a variety of sources, but the primary sources include the Hanford GIS database system, engineer drawings, and historic maps. In addition to these maps, several assumptions can be made about areas of disturbance in the 300 Area as a result of this study: o o Buried pipelines are not always located where they are mapped. As a result, cultural resource monitors or specialists should not depend on maps depicting subsurface pipelines for accurate locations of previous disturbance. Temporary roads built in the early 1940s were placed on layers of sand and gravel 8 to 12 in. thick. Given this information, it is likely that substrates beneath these early roads are only minimally disturbed. Building foundations ranged from concrete slabs no more than 6 to 8 in. thick to deeply excavated pits and basements. Buildings constructed with slab foundations are more numerous than may be expected, and minimally disturbed substrates may be expected in these locations. Historic black

  8. A measurement-driven approach to assess power line telecommunication (PLT) network quality of service (QoS) performance parameters

    NASA Astrophysics Data System (ADS)

    Betta, G.; Capriglione, D.; Ferrigno, L.; Laracca, M.

    2009-10-01

    Power line telecommunication (PLT) technology offers cheap and fast ways for providing in-home broadband services and local area networking. Its main advantage is due to the possibility of using the pre-existing electrical grid as a communication channel. Nevertheless, technical challenges arise from the difficulty of operating on a hostile medium, not designed for communication purposes, characterized by complex channel modeling and by varying time response. These aspects put practical problems for designers and testers in the assessment of network quality of service performance parameters such as the throughput, the latency, the jitter, and the reliability. The measurement of these parameters has not yet been standardized so that there do not exist reference test set-ups and measurement methodologies (i.e. the type of isolation from the ac main, the observation time and the number of experiments, the measurement uncertainty and so on). Consequently, experiments executed by adopting different methods may lead to incompatible measurement results, thus making it also impossible to have reliable comparisons of different PLT modems. Really, the development of standard procedures is a very difficult task because the scenarios in which the PLT modems can work are very wide and then the application of an exhaustive approach (in which all the parameters influencing the PLT performance should be considered) would be very complex and time consuming, thus making the modem characterization very expensive. In this paper, the authors propose a methodological approach to develop an efficient measurement procedure able to reliably assess the performance of PLT modems (in terms of network quality of service parameters) with a minimum number of experiments. It is based on both creating a reconfigurable grid to which real disturbing loads are connected and implementing an original design of the experiment technique based on the effects of the uncertainty of the measurement results

  9. Improving Power Quality in Low-Voltage Networks Containing Distributed Energy Resources

    NASA Astrophysics Data System (ADS)

    Mazumder, Sumit; Ghosh, Arindam; Zare, Firuz

    2013-05-01

    Severe power quality problems can arise when a large number of single-phase distributed energy resources (DERs) are connected to a low-voltage power distribution system. Due to the random location and size of DERs, it may so happen that a particular phase generates excess power than its load demand. In such an event, the excess power will be fed back to the distribution substation and will eventually find its way to the transmission network, causing undesirable voltage-current unbalance. As a solution to this problem, the article proposes the use of a distribution static compensator (DSTATCOM), which regulates voltage at the point of common coupling (PCC), thereby ensuring balanced current flow from and to the distribution substation. Additionally, this device can also support the distribution network in the absence of the utility connection, making the distribution system work as a microgrid. The proposals are validated through extensive digital computer simulation studies using PSCADTM.

  10. Application of Power Ultrasound on the Convective Drying of Fruits and Vegetables: Effects on quality.

    PubMed

    Rodríguez, Óscar; Eim, Valeria; Rosselló, Carmen; Femenia, Antoni; Cárcel, Juan A; Simal, Susana

    2017-09-14

    Drying allows the obtaining of products with a long shelf life by reducing the water activity to a level low enough for the growth of microorganisms, enzymatic reactions, and other deteriorative reactions to be inhibited. Despite the benefits of this operation, the quality of heat sensitive products is diminished when high temperatures are used. The use of low drying temperatures reduces the heat damage but being the drying time longer, oxidation reactions occur and a reduction of the quality is also observed. Thus, drying is a method that lends itself to being intensified. For this reason, alternative techniques are being studied. Power ultrasound is considered an emerging and promising technology in the food industry. The potential of this technology relies on its ability to accelerate the mass transfer processes in solid-liquid and solid-gas systems. The intensification of the drying process by means of power ultrasound can be performed by modifying the product behavior during drying, using pre-treatments like soaking in liquid medium assisted acoustically or during the drying process itself applying power ultrasound in the gaseous medium. The purpose of this review is to provide a summary of the effects caused by the power ultrasound application on the quality of different dried products, such as fruits and vegetables when the acoustic energy is intended to intensify the drying process, either if the application is performed before as pretreatment or during the drying process. This article is protected by copyright. All rights reserved.

  11. Tube focal spot size and power capability impact image quality in the evaluation of intracoronary stents

    NASA Astrophysics Data System (ADS)

    Cesmeli, Erdogan; Berry, Joel L.; Carr, J. J.

    2005-04-01

    Proliferation of coronary stent deployment for treatment of coronary heart disease (CHD) creates a need for imaging-based follow-up examinations to assess patency. Technological improvements in multi-detector computer tomography (MDCT) make it a potential non-invasive alternative to coronary catheterization for evaluation of stent patency; however, image quality with MDCT varies based on the size and composition of the stent. We studied the role of tube focal spot size and power in the optimization of image quality in a stationary phantom. A standard uniform physical phantom with a tubular insert was used where coronary stents (4 mm in diameter) were deployed in a tube filled with contrast to simulate a typical imaging condition observed in clinical practice. We utilized different commercially available stents and scanned them with different tube voltage and current settings (LightSpeed Pro16, GE Healthcare Technologies, Waukesha, WI, USA). The scanner used different focal spot size depending on the power load and thus allowed us to assess the combined effect of the focal spot size and the power. A radiologist evaluated the resulting images in terms of image quality and artifacts. For all stents, we found that the small focal spot size yielded better image quality and reduced artifacts. In general, higher power capability for the given focal spot size improved the signal-to-noise ratio in the images allowing improved assessment. Our preliminary study in a non-moving phantom suggests that a CT scanner that can deliver the same power on a small focal spot size is better suited to have an optimized scan protocol for reliable stent assessment.

  12. Multifunctional voltage source inverter for renewable energy integration and power quality conditioning.

    PubMed

    Dai, NingYi; Lam, Chi-Seng; Zhang, WenChen

    2014-01-01

    In order to utilize the energy from the renewable energy sources, power conversion system is necessary, in which the voltage source inverter (VSI) is usually the last stage for injecting power to the grid. It is an economical solution to add the function of power quality conditioning to the grid-connected VSI in the low-voltage distribution system. Two multifunctional VSIs are studied in this paper, that is, inductive-coupling VSI and capacitive-coupling VSI, which are named after the fundamental frequency impedance of their coupling branch. The operation voltages of the two VSIs are compared when they are used for renewable energy integration and power quality conditioning simultaneously. The operation voltage of the capacitive-coupling VSI can be set much lower than that of the inductive-coupling VSI when reactive power is for compensating inductive loads. Since a large portion of the loads in the distribution system are inductive, the capacitive-coupling VSI is further studied. The design and control method of the multifunctional capacitive-coupling VSI are proposed in this paper. Simulation and experimental results are provided to show its validity.

  13. Multifunctional Voltage Source Inverter for Renewable Energy Integration and Power Quality Conditioning

    PubMed Central

    Dai, NingYi; Lam, Chi-Seng; Zhang, WenChen

    2014-01-01

    In order to utilize the energy from the renewable energy sources, power conversion system is necessary, in which the voltage source inverter (VSI) is usually the last stage for injecting power to the grid. It is an economical solution to add the function of power quality conditioning to the grid-connected VSI in the low-voltage distribution system. Two multifunctional VSIs are studied in this paper, that is, inductive-coupling VSI and capacitive-coupling VSI, which are named after the fundamental frequency impedance of their coupling branch. The operation voltages of the two VSIs are compared when they are used for renewable energy integration and power quality conditioning simultaneously. The operation voltage of the capacitive-coupling VSI can be set much lower than that of the inductive-coupling VSI when reactive power is for compensating inductive loads. Since a large portion of the loads in the distribution system are inductive, the capacitive-coupling VSI is further studied. The design and control method of the multifunctional capacitive-coupling VSI are proposed in this paper. Simulation and experimental results are provided to show its validity. PMID:25177725

  14. Optical quality of rotationally symmetrical contact lenses derived from their power profiles.

    PubMed

    Del Águila-Carrasco, Antonio J; Monsálvez-Romín, Daniel; Papadatou, Eleni

    2017-10-01

    To present a methodology for evaluating the optical quality of rotationally symmetrical contact lenses (CLs) from a single power profile. Simulated rotationally symmetrical power profiles corresponding to different CLs designs (monofocal, two-zone center-near bifocal, and four-zone center-distance bifocal) were used to calculate the wavefront error profile by means of numerical integration. Then, each lens wavefront error profile was spun around the center to obtain the lens wavefront error surface. From the surface, monochromatic optical transfer functions (OTF), simulated images and the visual Strehl ratio based on the OTF (VSOTF) were obtained for different distances and pupil sizes (3 and 5.5mm) after performing a through-focus. VSOTF variations, taking into account both vergence and pupil size, were presented for the three CLs designs. The monofocal design showed excellent optical quality only for far vision, whereas the bifocal designs exhibited good optical quality for far and near vision. Modulation transfer function (MTF) from each lens design, pupil size, and work distance agreed with the previous results. The methodology presented here allows for a rapid and thorough assessment of the optical quality of rotationally symmetrical CLs by means of optical quality metrics, with a special interest in simultaneous image contact lenses. This methodology may be useful for choosing the most suitable lens for each subject's visual demands. Copyright © 2017 British Contact Lens Association. Published by Elsevier Ltd. All rights reserved.

  15. 10 CFR Appendix B to Part 50 - Quality Assurance Criteria for Nuclear Power Plants and Fuel Reprocessing Plants

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 10 Energy 1 2012-01-01 2012-01-01 false Quality Assurance Criteria for Nuclear Power Plants and... Criteria for Nuclear Power Plants and Fuel Reprocessing Plants Introduction. Every applicant for a..., and components of the reactor. Nuclear power plants and fuel reprocessing plants include...

  16. 10 CFR Appendix B to Part 50 - Quality Assurance Criteria for Nuclear Power Plants and Fuel Reprocessing Plants

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 10 Energy 1 2013-01-01 2013-01-01 false Quality Assurance Criteria for Nuclear Power Plants and... Criteria for Nuclear Power Plants and Fuel Reprocessing Plants Introduction. Every applicant for a..., and components of the reactor. Nuclear power plants and fuel reprocessing plants include...

  17. 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

    ... 10 Energy 1 2014-01-01 2014-01-01 false Quality Assurance Criteria for Nuclear Power Plants and... Criteria for Nuclear Power Plants and Fuel Reprocessing Plants Introduction. Every applicant for a..., and components of the reactor. Nuclear power plants and fuel reprocessing plants include...

  18. 10 CFR Appendix B to Part 50 - Quality Assurance Criteria for Nuclear Power Plants and Fuel Reprocessing Plants

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 10 Energy 1 2010-01-01 2010-01-01 false Quality Assurance Criteria for Nuclear Power Plants and... Criteria for Nuclear Power Plants and Fuel Reprocessing Plants Introduction. Every applicant for a..., and components of the reactor. Nuclear power plants and fuel reprocessing plants include...

  19. 10 CFR Appendix B to Part 50 - Quality Assurance Criteria for Nuclear Power Plants and Fuel Reprocessing Plants

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 10 Energy 1 2011-01-01 2011-01-01 false Quality Assurance Criteria for Nuclear Power Plants and... Criteria for Nuclear Power Plants and Fuel Reprocessing Plants Introduction. Every applicant for a..., and components of the reactor. Nuclear power plants and fuel reprocessing plants include...

  20. High power, high beam quality solid state lasers for materials processing applications

    SciTech Connect

    Hackel, L.A.; Dane, C.B.; Hermann, M.R.

    1994-08-01

    The Laser Science and Technology Department at Lawrence Livermore National Laboratory is developing solid state lasers with high average power and high beam quality. Specific systems include a laser to generate 10 to 14 {angstrom} x-rays for proximity print lithography, a 400 mJ, 500 Hz laser for 130 {angstrom} projection lithography and unique systems for speckle imaging, laser radars and medical treatments.

  1. Understanding coal quality and its relationship to power plant performance and costs

    SciTech Connect

    Jennison, K.D.; Stallard, G.S.

    1995-12-01

    The availability of reliable, reasonably priced energy is a necessary cornerstone for established and emerging economies. In addition to addressing coal quality issues strictly at a plant level, it is now prudent to consider long-term performance and economics of particular fuel sources to be selected in the light of system economics and reliability. In order to evaluate coal quality issues in a more comprehensive manner, it is important to develop both an approach and a set of tools which can support the various phases of the planning/analysis processes. The processes must consider the following: (1) Cost/availability of other potential coal supplies, including {open_quotes}raw{close_quotes} domestic sources, {open_quotes}cleaned {close_quotes} domestic sources, and other internationally marketed coals. (2) Power plant performance issues as function of plant design and fuel properties. (3) System expansion plans, candidate technologies, and associated capital and operating costs. (4) Projected load demand, for system and for individual units within the system. (5) Legislative issues such as environmental pressures, power purchase agreements, etc. which could alter the solution. (6) Economics of potential plans/strategies based on overall cost-effectiveness of the utility system, not just individual units. (7) Anticipated unit configuration, including addition of environmental control equipment or other repowering options. The Coal Quality Impact Model (CQIM{trademark}) is a PC-based computer program capable of predicting coal-related cost and performance impacts at electric power generating sites. The CQIM was developed for EPRI by Black & Veatch and represents over a decade of effort geared toward developing an extensible state-of-the-art coal quality assessment tool. This paper will introduce CQIM, its capabilities, and its application to Eastern European coal quality assessment needs.

  2. Adaptive Harmonic Detection Control of Grid Interfaced Solar Photovoltaic Energy System with Power Quality Improvement

    NASA Astrophysics Data System (ADS)

    Singh, B.; Goel, S.

    2015-03-01

    This paper presents a grid interfaced solar photovoltaic (SPV) energy system with a novel adaptive harmonic detection control for power quality improvement at ac mains under balanced as well as unbalanced and distorted supply conditions. The SPV energy system is capable of compensation of linear and nonlinear loads with the objectives of load balancing, harmonics elimination, power factor correction and terminal voltage regulation. The proposed control increases the utilization of PV infrastructure and brings down its effective cost due to its other benefits. The adaptive harmonic detection control algorithm is used to detect the fundamental active power component of load currents which are subsequently used for reference source currents estimation. An instantaneous symmetrical component theory is used to obtain instantaneous positive sequence point of common coupling (PCC) voltages which are used to derive inphase and quadrature phase voltage templates. The proposed grid interfaced PV energy system is modelled and simulated in MATLAB Simulink and its performance is verified under various operating conditions.

  3. A Reliable Data Delivery Mechanism for Grid Power Quality Using Neural Networks in Wireless Sensor Networks

    PubMed Central

    Lim, Yujin; Kim, Hak-Man; Kang, Sanggil

    2010-01-01

    Power grids deal with the business of generation, transmission, and distribution of electric power. Current systems monitor basic electrical quantities such as voltage and current from major pole transformers using their temperature. We improve the current systems in order to gather and deliver the information of power qualities such as harmonics, voltage sags, and voltage swells. In the system, data delivery is not guaranteed for the case that a node is lost or the network is congested, because the system has in-line and multi-hop architecture. In this paper, we propose a reliable data delivery mechanism by modeling an optimal data delivery function by employing the neural network concept. PMID:22163411

  4. 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.

  5. Simulation and Study of Power Quality Issues in a Fixed Speed Wind Farm Substation

    PubMed Central

    Magesh, T.; Chellamuthu, C.

    2015-01-01

    Power quality issues associated with the fixed speed wind farm substation located at Coimbatore district are investigated as the wind generators are tripping frequently. The investigations are carried out using two power quality analyzers, Fluke 435 and Dranetz PX5.8, with one of them connected at group control breaker of the 110 kV feeder and the other at the selected 0.69 kV generator busbar during the period of maximum power generation. From the analysis of the recorded data it is found that sag, swell, and transients are the major events which are responsible for the tripping of the generators. In the present study, simulation models for wind, turbine, shaft, pitch mechanism, induction generator, and grid are developed using DIgSILENT. Using the turbine characteristics, a two-dimensional lookup table is designed to generate a reference pitch angle necessary to simulate the power curve of the passive stall controlled wind turbine. Various scenarios and their effects on the performance of the wind farm are studied and validated with the recorded data and waveforms. The simulation model will be useful for the designers for planning and development of the wind farm before implementation. PMID:25950016

  6. Distributed photovoltaic generation in residential distribution systems: Impacts on power quality and anti-islanding

    NASA Astrophysics Data System (ADS)

    Mitra, Parag

    The past few decades have seen a consistent growth of distributed PV sources. Distributed PV, like other DG sources, can be located at or near load centers and provide benefits which traditional generation may lack. However, distribution systems were not designed to accommodate such power generation sources as these sources might lead to operational as well as power quality issues. A high penetration of distributed PV resources may lead to bi-directional power flow resulting in voltage swells, increased losses and overloading of conductors. Voltage unbalance is a concern in distribution systems and the effect of single-phase residential PV systems on voltage unbalance needs to be explored. Furthermore, the islanding of DGs presents a technical hurdle towards the seamless integration of DG sources with the electricity grid. The work done in this thesis explores two important aspects of grid inte-gration of distributed PV generation, namely, the impact on power quality and anti-islanding. A test distribution system, representing a realistic distribution feeder in Arizona is modeled to study both the aforementioned aspects. The im-pact of distributed PV on voltage profile, voltage unbalance and distribution sys-tem primary losses are studied using CYMDIST. Furthermore, a PSCAD model of the inverter with anti-island controls is developed and the efficacy of the anti-islanding techniques is studied. Based on the simulations, generalized conclusions are drawn and the problems/benefits are elucidated.

  7. Total quality control: the deming management philosophy applied to nuclear power plants

    SciTech Connect

    Heising, C.D.; Wetherell, D.L.; Melhem, S.A.; Sato, M.

    1987-01-01

    In recent years, a call has come for the development of inherently safe nuclear reactor systems that cannot have large-scale accidents. In the search for the perfect inherently safe reactor system, some are calling for the institution of computerized automated control of reactors eliminating most human operators from the control room. A different approach to the problem of the control of inherently safe reactors is that both future and present nuclear power plants need to institute total quality control (TQC) to plant operations and management. The Deming management philosophy of TQC has been implemented in a wide range of industries - particularly in Japan and the US. Specific attention is given, however, to TQC implementation in the electric power industry as applied to nuclear plants. The Kansai Electric Power Company and Florida Power and Light Company have recently implemented TQC. Statistical quality control methods have been applied to monitor and control reactor variables (for example, to the steam generator water level important to start-up operations of pressurized water reactors).

  8. Simulation and study of power quality issues in a fixed speed wind farm substation.

    PubMed

    Magesh, T; Chellamuthu, C

    2015-01-01

    Power quality issues associated with the fixed speed wind farm substation located at Coimbatore district are investigated as the wind generators are tripping frequently. The investigations are carried out using two power quality analyzers, Fluke 435 and Dranetz PX5.8, with one of them connected at group control breaker of the 110 kV feeder and the other at the selected 0.69 kV generator busbar during the period of maximum power generation. From the analysis of the recorded data it is found that sag, swell, and transients are the major events which are responsible for the tripping of the generators. In the present study, simulation models for wind, turbine, shaft, pitch mechanism, induction generator, and grid are developed using DIgSILENT. Using the turbine characteristics, a two-dimensional lookup table is designed to generate a reference pitch angle necessary to simulate the power curve of the passive stall controlled wind turbine. Various scenarios and their effects on the performance of the wind farm are studied and validated with the recorded data and waveforms. The simulation model will be useful for the designers for planning and development of the wind farm before implementation.

  9. Far-field beam quality evaluation of high-power unstable resonators TEA CO2 Laser

    NASA Astrophysics Data System (ADS)

    Guo, Ruhai; Chen, Ning; Shi, Kui; Wang, Bing

    2013-05-01

    High average power pulsed TEA CO2 lasers have many important applications, such as laser manufacturing, military applications, but there rarely have reports about the theoretical and experimental studies on the virtual confocus resonator of pulsed TEA CO2 laser, especially its far field optical quality. Based on the real date of the unstable resonator modified by the stable resonator of high power TEA CO2, three common theoretical evaluations and analyzes were conducted and compared with the measured results of far field light intensity distribution with 2 kW designed unstable resonator laser with the block ratio is ɛ=0.404. The results show that the unstable resonator can obtain near diffraction limitation and high optical quality beam. The β factor is smaller than 4 times than the stable resonator. Furthermore, the smaller block factor can make higher power in bucket for the unstable resonator. The comprehensive prediction and evaluation of designed unstable resonator need to synthetically use these three theoretical methods of the evaluations. The simulation results, with considering the optical aberration, heat distortion and atmospheric effect, agree well with the real recording image by the infrared imaging system in the distance of 300m. The research of this paper has very important reference value for evaluating the tactical effectiveness and optimization design of high power TEA CO2 laser system with different unstable resonators.

  10. The climate and air-quality benefits of wind and solar power in the United States

    NASA Astrophysics Data System (ADS)

    Millstein, Dev; Wiser, Ryan; Bolinger, Mark; Barbose, Galen

    2017-09-01

    Wind and solar energy reduce combustion-based electricity generation and provide air-quality and greenhouse gas emission benefits. These benefits vary dramatically by region and over time. From 2007 to 2015, solar and wind power deployment increased rapidly while regulatory changes and fossil fuel price changes led to steep cuts in overall power-sector emissions. Here we evaluate how wind and solar climate and air-quality benefits evolved during this time period. We find cumulative wind and solar air-quality benefits of 2015 US$29.7-112.8 billion mostly from 3,000 to 12,700 avoided premature mortalities, and cumulative climate benefits of 2015 US$5.3-106.8 billion. The ranges span results across a suite of air-quality and health impact models and social cost of carbon estimates. We find that binding cap-and-trade pollutant markets may reduce these cumulative benefits by up to 16%. In 2015, based on central estimates, combined marginal benefits equal 7.3 ¢ kWh‑1 (wind) and 4.0 ¢ kWh‑1 (solar).

  11. Watt-class high-power, high-beam-quality photonic-crystal lasers

    NASA Astrophysics Data System (ADS)

    Hirose, Kazuyoshi; Liang, Yong; Kurosaka, Yoshitaka; Watanabe, Akiyoshi; Sugiyama, Takahiro; Noda, Susumu

    2014-05-01

    The applications of surface-emitting lasers, in particular vertical-cavity surface-emitting lasers (VCSELs), are currently being extended to various low-power fields including communications and interconnections. However, the fundamental difficulties in increasing their output power by more than several milliwatts while maintaining single-mode operation prevent their application in high-power fields such as material processing, laser medicine and nonlinear optics, despite their advantageous properties of circular beams, the absence of catastrophic optical damage, and their suitability for two-dimensional integration. Here, we demonstrate watt-class high-power, single-mode operation by a two-dimensional photonic-crystal surface-emitting laser under room-temperature, continuous-wave conditions. The two-dimensional band-edge resonant effect of a photonic crystal formed by metal-organic chemical vapour deposition enables a 1,000 times broader coherent-oscillation area, which results in a high beam quality of M2 <= 1.1, narrowing the focus spot by two orders of magnitude compared to VCSELs. Our demonstration promises to realize innovative high-power applications for surface-emitting lasers.

  12. Quantity, Quality, and Availability of Waste Heat from United States Thermal Power Generation.

    PubMed

    Gingerich, Daniel B; Mauter, Meagan S

    2015-07-21

    Secondary application of unconverted heat produced during electric power generation has the potential to improve the life-cycle fuel efficiency of the electric power industry and the sectors it serves. This work quantifies the residual heat (also known as waste heat) generated by U.S. thermal power plants and assesses the intermittency and transport issues that must be considered when planning to utilize this heat. Combining Energy Information Administration plant-level data with literature-reported process efficiency data, we develop estimates of the unconverted heat flux from individual U.S. thermal power plants in 2012. Together these power plants discharged an estimated 18.9 billion GJ(th) of residual heat in 2012, 4% of which was discharged at temperatures greater than 90 °C. We also characterize the temperature, spatial distribution, and temporal availability of this residual heat at the plant level and model the implications for the technical and economic feasibility of its end use. Increased implementation of flue gas desulfurization technologies at coal-fired facilities and the higher quality heat generated in the exhaust of natural gas fuel cycles are expected to increase the availability of residual heat generated by 10.6% in 2040.

  13. Identification af explosive power factors as predictors of player quality in young female volleyball players.

    PubMed

    Grgantov, Zoran; Milić, Mirjana; Katić, Ratko

    2013-05-01

    With the purpose of determining the factor structure of explosive power, as well as the influence of each factor on situational efficiency, 56 young female volleyball players were tested using 14 tests for assessing nonspecific and specific explosive power. By factor analysis, 4 significant factors were isolated which explained the total of over 80% of the common variability in young female volleyball players. The first factor was defined as volleyball-specific jumping, the second factor as nonspecific jumping and sprinting, the third factor as throwing explosive power, while the fourth factor was interpreted as volleyball-specific throwing and spiking speed from the ground. Results obtained by regression analysis in the latent space of explosive power indicate that the identified factors are good predictors of player quality in young female volleyball players. The fourth factor defined as throwing and spiking speed from the ground had the largest influence on player quality, followed by volleyball-specific jumping and nonspecific jumping and sprinting, and to a much lesser extent, by throwing explosive power The results obtained in this age group bring to the fore the ability of spiking and serving a ball of high speed, which hinders the opponents from playing those balls in serve reception and field defence. This ability, combined with a high standing vertical jump reach and spike approach vertical jump reach (which is the basis of the 1st varimax factor) enables successful performance of all volleyball elements by which points are won in complex 1 (spike) and complex 2 (serve and block). Even though the 2nd factor (nonspecific jumping and sprinting) has a slightly smaller impact on situational efficiency in young players, this ability provides preconditions i.e. preparation for successful realisation of all volleyball elements, so greater attention must be paid to perfecting it in young female volleyball players.

  14. Competing Air Quality and Water Conservation Co-benefits from Power Sector Decarbonization

    NASA Astrophysics Data System (ADS)

    Peng, W.; Wagner, F.; Mauzerall, D. L.; Ramana, M. V.; Zhai, H.; Small, M.; Zhang, X.; Dalin, C.

    2016-12-01

    Decarbonizing the power sector can reduce fossil-based generation and associated air pollution and water use. However, power sector configurations that prioritize air quality benefits can be different from those that maximize water conservation benefits. Despite extensive work to optimize the generation mix under an air pollution or water constraint, little research has examined electricity transmission networks and the choice of which fossil fuel units to displace in order to achieve both environmental objectives simultaneously. When air pollution and water stress occur in different regions, the optimal transmission and displacement decisions still depend on priorities placed on air quality and water conservation benefits even if low-carbon generation planning is fixed. Here we use China as a test case, and develop a new optimization framework to study transmission and displacement decisions and the resulting air quality and water use impacts for six power sector decarbonization scenarios in 2030 ( 50% of national generation is low carbon). We fix low-carbon generation in each scenario (e.g. type, location, quantity) and vary technology choices and deployment patterns across scenarios. The objective is to minimize the total physical costs (transmission costs and coal power generation costs) and the estimated environmental costs. Environmental costs are estimated by multiplying effective air pollutant emissions (EMeff, emissions weighted by population density) and effective water use (Weff, water use weighted by a local water stress index) by their unit economic values, Vem and Vw. We are hence able to examine the effect of varying policy priorities by imposing different combinations of Vem and Vw. In all six scenarios, we find that increasing the priority on air quality co-benefits (higher Vem) reduces air pollution impacts (lower EMeff) at the expense of lower water conservation (higher Weff); and vice versa. Such results can largely be explained by differences

  15. Potential Impact of the National Plan for Future Electric Power Supply on Air Quality in Korea

    NASA Astrophysics Data System (ADS)

    Shim, C.; Hong, J.

    2014-12-01

    Korean Ministry of Trade, Industry and Energy (MOTIE) announced the national plan for Korea's future electric power supply (2013 - 2027) in 2013. According to the plan, the national demand for electricity will be increased by 60% compared to that of 2010 and primary energy sources for electric generation will still lean on the fossil fuels such as petroleum, LNG, and coal, which would be a potential threat to air quality of Korea. This study focused on two subjects: (1) How the spatial distribution of the primary air pollutant's emissions (i.e., NOx, SOx, CO, PM) will be changed and (2) How the primary emission changes will influence on the national ambient air quality including ozone in 2027. We used GEOS-Chem model simulation with modification of Korean emissions inventory (Clean Air Policy Support System (CAPSS)) to simulate the current and future air quality in Korea. The national total emissions of CO, NOx, SOx, PM in year 2027 will be increased by 3%, 8%, 13%, 2%, respectively compared to 2010 and there are additional concern that the future location of the power plants will be closer to the Seoul Metropolitan Area (SMA), where there are approximately 20 million population vulnerable to the potentially worsened air quality. While there are slight increase of concentration of CO, NOx, SOx, and PM in 2027, the O3 concentration is expected to be similar to the level of 2010. Those results may imply the characteristics of air pollution in East Asia such as potentially severe O3 titration and poorer O3/CO or O3/NOx ratio. Furthermore, we will discuss on the impact of transboundary pollution transport from China in the future, which is one of the large factors to control the air quality of Korea.

  16. Power-Quality Improvement in PFC Bridgeless SEPIC-Fed BLDC Motor Drive

    NASA Astrophysics Data System (ADS)

    Singh, Bhim; Bist, Vashist

    2013-06-01

    This article presents a design of a power factor correction (PFC)-based brushless DC (BLDC) motor drive. The speed control of BLDC motor is achieved by controlling the DC link voltage of the voltage source inverter (VSI) feeding BLDC motor using a single voltage sensor. A front-end bridgeless single-ended primary inductance converter (SEPIC) is used for DC link voltage control and PFC operation. A bridgeless SEPIC is designed to operate in discontinuous inductor current mode (DICM) thus utilizing a simple control scheme of voltage follower. An electronic commutation of BLDC motor is used for VSI to operate in a low-frequency operation for reduced switching losses in the VSI. Moreover, a bridgeless topology offers less conduction losses due to absence of diode bridge rectifier for further increasing the efficiency. The proposed BLDC motor drive is designed to operate over a wide range of speed control with an improved power-quality at the AC mains under the recommended international power-quality standards such as IEC 61000-3-2.

  17. Reaction Wheel Disturbance Model Extraction Software - RWDMES

    NASA Technical Reports Server (NTRS)

    Blaurock, Carl

    2009-01-01

    The RWDMES is a tool for modeling the disturbances imparted on spacecraft by spinning reaction wheels. Reaction wheels are usually the largest disturbance source on a precision pointing spacecraft, and can be the dominating source of pointing error. Accurate knowledge of the disturbance environment is critical to accurate prediction of the pointing performance. In the past, it has been difficult to extract an accurate wheel disturbance model since the forcing mechanisms are difficult to model physically, and the forcing amplitudes are filtered by the dynamics of the reaction wheel. RWDMES captures the wheel-induced disturbances using a hybrid physical/empirical model that is extracted directly from measured forcing data. The empirical models capture the tonal forces that occur at harmonics of the spin rate, and the broadband forces that arise from random effects. The empirical forcing functions are filtered by a physical model of the wheel structure that includes spin-rate-dependent moments (gyroscopic terms). The resulting hybrid model creates a highly accurate prediction of wheel-induced forces. It accounts for variation in disturbance frequency, as well as the shifts in structural amplification by the whirl modes, as the spin rate changes. This software provides a point-and-click environment for producing accurate models with minimal user effort. Where conventional approaches may take weeks to produce a model of variable quality, RWDMES can create a demonstrably high accuracy model in two hours. The software consists of a graphical user interface (GUI) that enables the user to specify all analysis parameters, to evaluate analysis results and to iteratively refine the model. Underlying algorithms automatically extract disturbance harmonics, initialize and tune harmonic models, and initialize and tune broadband noise models. The component steps are described in the RWDMES user s guide and include: converting time domain data to waterfall PSDs (power spectral

  18. Why do electricity policy and competitive markets fail to use advanced PV systems to improve distribution power quality?

    DOE PAGES

    McHenry, Mark P.; Johnson, Jay; Hightower, Mike

    2016-01-01

    The increasing pressure for network operators to meet distribution network power quality standards with increasing peak loads, renewable energy targets, and advances in automated distributed power electronics and communications is forcing policy-makers to understand new means to distribute costs and benefits within electricity markets. Discussions surrounding how distributed generation (DG) exhibits active voltage regulation and power factor/reactive power control and other power quality capabilities are complicated by uncertainties of baseline local distribution network power quality and to whom and how costs and benefits of improved electricity infrastructure will be allocated. DG providing ancillary services that dynamically respond to the networkmore » characteristics could lead to major network improvements. With proper market structures renewable energy systems could greatly improve power quality on distribution systems with nearly no additional cost to the grid operators. Renewable DG does have variability challenges, though this issue can be overcome with energy storage, forecasting, and advanced inverter functionality. This paper presents real data from a large-scale grid-connected PV array with large-scale storage and explores effective mitigation measures for PV system variability. As a result, we discuss useful inverter technical knowledge for policy-makers to mitigate ongoing inflation of electricity network tariff components by new DG interconnection requirements or electricity markets which value power quality and control.« less

  19. Remote Borehole Strainmeter Sites: Power system optimization improves data quality and increases equipment uptime

    NASA Astrophysics Data System (ADS)

    Pyatt, C.; Van Boskirk, E.; Gallaher, W.; Hodgkinson, K. M.; Henderson, D. B.; Gottlieb, M. H.; Johnson, W.; Fox, O.; Mencin, D.; Mattioli, G.

    2012-12-01

    have been installed as a secondary power source. The fuel cells provide an alternative power source during the lower light winter conditions. The power system modifications have had an immediate and positive impact in data quality and instrument uptime. Inspection of strainmeter data in the frequency domain shows considerable improvement in noise levels. Most solar sites remained online throughout the winter months, ensuring a continuous data stream.

  20. Quantity and quality in nuclear engineering professional skills needed by the nuclear power industry

    SciTech Connect

    Slember, R.J.

    1990-01-01

    This paper examines the challenge of work force requirements in the context of the full range of issues facing the nuclear power industry. The supply of skilled managers and workers may be a more serious problem if nuclear power fades away than if it is reborn in a new generation. An even greater concern, however, is the quality of education that the industry needs in all its future professionals. Both government and industry should be helping universities adapt their curricula to the needs of the future. This means building a closer relationship with schools that educate nuclear professionals, that is, providing adequate scholarships and funding for research and development programs, offering in-kind services, and encouraging internships and other opportunities for hands-on experience. The goal should not be just state-of-the-art engineering practices, but the broad range of knowledge, issues, and skills that will be required of the nuclear leadership of the twenty-first century.

  1. Improving healthcare quality through organisational peer-to-peer assessment: lessons from the nuclear power industry

    PubMed Central

    Pronovost, Peter J; Hudson, Daniel W

    2012-01-01

    Healthcare has made great efforts to reduce preventable patient harm, from externally driven regulations to internally driven professionalism. Regulation has driven the majority of efforts to date, and has a necessary place in establishing accountability and minimum standards. Yet they need to be coupled with internally driven efforts. Among professional groups, internally-driven efforts that function as communities of learning and change social norms are highly effective tools to improve performance, yet these approaches are underdeveloped in healthcare. Healthcare can learn much from the nuclear power industry. The nuclear power industry formed the Institute of Nuclear Power Operators following the Three Mile Island accident to improve safety. That organization established a peer-to-peer assessment program to cross-share best practices, safety hazards, problems and actions that improved safety and operational performance. This commentary explores how a similar program could be expanded into healthcare. Healthcare needs a structured, clinician-led, industry-wide process to openly review, identify and mitigate hazards, and share best practices that ultimately improve patient safety. A healthcare version of the nuclear power program could supplement regulatory and other strategies currently used to improve quality and patient safety. PMID:22562877

  2. Improving healthcare quality through organisational peer-to-peer assessment: lessons from the nuclear power industry.

    PubMed

    Pronovost, Peter J; Hudson, Daniel W

    2012-10-01

    Healthcare has made great efforts to reduce preventable patient harm, from externally driven regulations to internally driven professionalism. Regulation has driven the majority of efforts to date, and has a necessary place in establishing accountability and minimum standards. Yet they need to be coupled with internally driven efforts. Among professional groups, internally-driven efforts that function as communities of learning and change social norms are highly effective tools to improve performance, yet these approaches are underdeveloped in healthcare. Healthcare can learn much from the nuclear power industry. The nuclear power industry formed the Institute of Nuclear Power Operators following the Three Mile Island accident to improve safety. That organization established a peer-to-peer assessment program to cross-share best practices, safety hazards, problems and actions that improved safety and operational performance. This commentary explores how a similar program could be expanded into healthcare. Healthcare needs a structured, clinician-led, industry-wide process to openly review, identify and mitigate hazards, and share best practices that ultimately improve patient safety. A healthcare version of the nuclear power program could supplement regulatory and other strategies currently used to improve quality and patient safety.

  3. Diagnostic tools to determine the quality of "transparent" regression-based QSARs: the "modelling power" plot.

    PubMed

    Sagrado, Salvador; Cronin, Mark T D

    2006-01-01

    A bivariate plot is presented for comparing two or more QSAR models. It is based on two new statistics associated with a regression model, the "descriptive power" (Dp), which is estimated through the relative uncertainty of model coefficients, and the "predictive power" (Pp), which is estimated through both the fitted and cross-validated explained variance of the response variable (i.e., biological activity). An algorithm was developed for performing equivalent multiple linear regression and partial-least-squares calculations. The results were validated by comparison with widely accepted commercial software. Dp and Pp statistics are defined to vary from 0 to 100%, so the modeler has a intuitive impression of the descriptive (i.e., global importance of the selected descriptors) and predictive (i.e., possibility of performing QSAR or just SAR estimations) power. These statistics represent a point in the Dp versus Pp "modelling power" plot, which facilitates visual multiple models comparison, but also could be used to substitute classical statistics and could even be combined to obtain a unique parameter to define (or compare) the model's quality.

  4. A Logistic Life Cycle Cost-Benefit Analysis of Power Quality Management in the Avionics Repair Facility

    DTIC Science & Technology

    1998-06-01

    distribution is unlimited. 12b. DISTRIBUTION CODE 13. ABSTRACT (maximum 200 words) The objective of this research is to investigate the impact that...of this research is to investigate the impact that power quality management can have on the intermediate level of maintenance. Power quality...MAINTENANCE PROGRAM 7 A.NAVAL AIRCRAFT MAINTENANCE PHILOSOPHY 7 B. MAINTENANCE CONCEPTS AND LEVELS 8 1. Organizational Maintenance 9 2.1ntermediate

  5. Photovoltaic Impact Assessment of Smart Inverter Volt-VAR Control on Distribution System Conservation Voltage Reduction and Power Quality

    SciTech Connect

    Ding, Fei; Nagarajan, Adarsh; Chakraborty, Sudipta; Baggu, Murali; Nguyen, Andu; Walinga, Sarah; McCarty, Michael; Bell, Frances

    2016-12-01

    This report presents an impact assessment study of distributed photovoltaic (PV) with smart inverter Volt-VAR control on conservation voltage reduction (CVR) energy savings and distribution system power quality. CVR is a methodology of flattening and lowering a distribution system voltage profile in order to conserve energy. Traditional CVR relies on operating utility voltage regulators and switched capacitors. However, with the increased penetration of distributed PV systems, smart inverters provide the new opportunity to control local voltage and power factor by regulating the reactive power output, leading to a potential increase in CVR energy savings. This report proposes a methodology to implement CVR scheme by operating voltage regulators, capacitors, and autonomous smart inverter Volt-VAR control in order to achieve increased CVR benefit. Power quality is an important consideration when operating a distribution system, especially when implementing CVR. It is easy to measure the individual components that make up power quality, but a comprehensive method to incorporate all of these values into a single score has yet to be undertaken. As a result, this report proposes a power quality scoring mechanism to measure the relative power quality of distribution systems using a single number, which is aptly named the 'power quality score' (PQS). Both the CVR and PQS methodologies were applied to two distribution system models, one obtained from the Hawaiian Electric Company (HECO) and another obtained from Pacific Gas and Electric (PG&E). These two models were converted to the OpenDSS platform using previous model conversion tools that were developed by NREL. Multiple scenarios including various PV penetration levels and smart inverter densities were simulated to analyze the impact of smart inverter Volt-VAR support on CVR energy savings and feeder power quality. In order to analyze the CVR benefit and PQS, an annual simulation was conducted for each scenario.

  6. Slip-Sliding-Away: A Review of the Literature on the Constraining Qualities of PowerPoint

    ERIC Educational Resources Information Center

    Kernbach, Sebastian; Bresciani, Sabrina; Eppler, Martin J.

    2015-01-01

    PowerPoint is a dominant communication tool in business and education. It allows for creating professional-looking presentations easily, but without understanding its constraining qualities it can be used inappropriately. Therefore we conducted a systematic literature review structuring the literature on PowerPoint in three chronological phases…

  7. Slip-Sliding-Away: A Review of the Literature on the Constraining Qualities of PowerPoint

    ERIC Educational Resources Information Center

    Kernbach, Sebastian; Bresciani, Sabrina; Eppler, Martin J.

    2015-01-01

    PowerPoint is a dominant communication tool in business and education. It allows for creating professional-looking presentations easily, but without understanding its constraining qualities it can be used inappropriately. Therefore we conducted a systematic literature review structuring the literature on PowerPoint in three chronological phases…

  8. Control of disturbing loads in residential and commercial buildings via geometric algebra.

    PubMed

    Castilla, Manuel-V

    2013-01-01

    Many definitions have been formulated to represent nonactive power for distorted voltages and currents in electronic and electrical systems. Unfortunately, no single universally suitable representation has been accepted as a prototype for this power component. This paper defines a nonactive power multivector from the most advanced multivectorial power theory based on the geometric algebra (GA). The new concept can have more importance on harmonic loads compensation, identification, and metering, between other applications. Likewise, this paper is concerned with a pioneering method for the compensation of disturbing loads. In this way, we propose a multivectorial relative quality index δ(~) associated with the power multivector. It can be assumed as a new index for power quality evaluation, harmonic sources detection, and power factor improvement in residential and commercial buildings. The proposed method consists of a single-point strategy based of a comparison among different relative quality index multivectors, which may be measured at the different loads on the same metering point. The comparison can give pieces of information with magnitude, direction, and sense on the presence of disturbing loads. A numerical example is used to illustrate the clear capabilities of the suggested approach.

  9. Control of Disturbing Loads in Residential and Commercial Buildings via Geometric Algebra

    PubMed Central

    2013-01-01

    Many definitions have been formulated to represent nonactive power for distorted voltages and currents in electronic and electrical systems. Unfortunately, no single universally suitable representation has been accepted as a prototype for this power component. This paper defines a nonactive power multivector from the most advanced multivectorial power theory based on the geometric algebra (GA). The new concept can have more importance on harmonic loads compensation, identification, and metering, between other applications. Likewise, this paper is concerned with a pioneering method for the compensation of disturbing loads. In this way, we propose a multivectorial relative quality index  δ~ associated with the power multivector. It can be assumed as a new index for power quality evaluation, harmonic sources detection, and power factor improvement in residential and commercial buildings. The proposed method consists of a single-point strategy based of a comparison among different relative quality index multivectors, which may be measured at the different loads on the same metering point. The comparison can give pieces of information with magnitude, direction, and sense on the presence of disturbing loads. A numerical example is used to illustrate the clear capabilities of the suggested approach. PMID:24260017

  10. Human DNA quantification and sample quality assessment: Developmental validation of the PowerQuant(®) system.

    PubMed

    Ewing, Margaret M; Thompson, Jonelle M; McLaren, Robert S; Purpero, Vincent M; Thomas, Kelli J; Dobrowski, Patricia A; DeGroot, Gretchen A; Romsos, Erica L; Storts, Douglas R

    2016-07-01

    Quantification of the total amount of human DNA isolated from a forensic evidence item is crucial for DNA normalization prior to short tandem repeat (STR) DNA analysis and a federal quality assurance standard requirement. Previous commercial quantification methods determine the total human DNA and total human male DNA concentrations, but provide limited information about the condition of the DNA sample. The PowerQuant(®) System includes targets for quantification of total human and total human male DNA as well as targets for evaluating whether the human DNA is degraded and/or PCR inhibitors are present in the sample. A developmental validation of the PowerQuant(®) System was completed, following SWGDAM Validation Guidelines, to evaluate the assay's specificity, sensitivity, precision and accuracy, as well as the ability to detect degraded DNA or PCR inhibitors. In addition to the total human DNA and total human male DNA concentrations in a sample, data from the degradation target and internal PCR control (IPC) provide a forensic DNA analyst meaningful information about the quality of the isolated human DNA and the presence of PCR inhibitors in the sample that can be used to determine the most effective workflow and assist downstream interpretation. Copyright © 2016 The Author(s). Published by Elsevier Ireland Ltd.. All rights reserved.

  11. High power broadband all fiber super-fluorescent source with linear polarization and near diffraction-limited beam quality.

    PubMed

    Ma, Pengfei; Huang, Long; Wang, Xiaolin; Zhou, Pu; Liu, Zejin

    2016-01-25

    In this manuscript, a high power broadband superfluorescent source (SFS) with linear polarization and near-diffraction-limited beam quality is achieved based on an ytterbium-doped (Yb-doped), all fiberized and polarization-maintained master oscillator power amplifier (MOPA) configuration. The MOPA structure generates a linearly polarized output power of 1427 W with a slope efficiency of 80% and a full width at half maximum (FWHM) of 11 nm, which is power scaled by an order of magnitude compared with the previously reported SFSs with linear polarization. In the experiment, both the polarization extinction ratio (PER) and beam quality (M(2) factor) are degraded little during the power scaling process. At maximal output power, the PER and M(2) factor are measured to be 19.1dB and 1.14, respectively. The root-mean-square (RMS) and peak-vale (PV) values of the power fluctuation at maximal output power are just 0.48% and within 3%, respectively. Further power scaling of the whole system is limited by the available pump sources. To the best of our knowledge, this is the first demonstration of kilowatt level broadband SFS with linear polarization and near-diffraction-limited beam quality.

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

    NASA Astrophysics Data System (ADS)

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

    2017-04-01

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

  13. Wind Turbine Generator System Power Quality Test Report for the Gaia Wind 11-kW Wind Turbine

    SciTech Connect

    Curtis, A.; Gevorgian, V.

    2011-07-01

    This report details the power quality test on the Gaia Wind 11-kW Wind Turbine as part of the U.S. Department of Energy's Independent Testing Project. In total five turbines are being tested as part of the project. Power quality testing is one of up to five test that may be performed on the turbines including power performance, safety and function, noise, and duration tests. The results of the testing provide manufacturers with reports that may be used for small wind turbine certification.

  14. Chemical and physicochemical quality parameters in carrots dehydrated by power ultrasound.

    PubMed

    Soria, Ana Cristina; Corzo-Martínez, Marta; Montilla, Antonia; Riera, Enrique; Gamboa-Santos, Juliana; Villamiel, Mar

    2010-07-14

    Preservation of the quality and bioactivity of carrots dehydrated by power ultrasound (US) under different experimental conditions including prior blanching has been evaluated for the first time by measuring the evolution of the Maillard reaction and the changes in soluble sugars, proteins, total polyphenols, antioxidant activity, and rehydration ability. This study also includes a comparison with a freeze-dried sample and data of commercial dehydrated carrots. The synergic effect of US and temperature (60 degrees C) increased the dehydration rate of carrots (90% moisture loss in only 75 min) while still providing carrots with a level of 2-furoylmethyl-amino acids significantly lower than that of dehydrated commercial samples. Whereas a decrease in the content of reducing soluble sugars was observed with processing temperature, minor carbohydrates (scyllo- and myo-inositol and sedoheptulose) were rather stable, irrespective of the US dehydration parameters. Blanching significantly improved the rehydration ability of US-dehydrated carrots without increasing the loss of soluble sugars by leaching. As supported by the similarity of most quality indicators studied in both US-treated and freeze-dried carrots, the mild processing conditions employed in US dehydration gave rise to premium quality dehydrated carrots.

  15. Impact of Power Ultrasound on the Quality of Fruits and Vegetables During Dehydration

    NASA Astrophysics Data System (ADS)

    Villamiel, Mar; Gamboa, Juliana; Soria, A. Cristina; Riera, Enrique; García-Pérez, José V.; Montilla, Antonia

    In the present work, the influence of power ultrasound (US) on the quality of fruits and vegetables during both the pre-treatment and drying has been evaluated. Chemical indicators such as pectinmethyl esterase and peroxidase enzymes, vitamin C, carbohydrates, proteins, polyphenols and 2-furoylmethylamino acids (indicators of the early stages of Maillard reaction) have been studied. In addition, rehydration capacity, leaching losses and shrinkage and organoleptic characteristics of the final product have also been assessed. During blanching, similar leaching losses and enzyme inactivation were found in low temperature and prolonged conventional treatments and in US processes, but with a significant reduction in the time for the latter. Finally, application of US in drying of carrots and strawberries originated significant reductions in processing time, while providing high quality end-products. The quality was higher as compared to marketed products and superior or equivalent to samples obtained under similar conditions in a prototype convective dryer, and, in the case of some indicators, similar to that of freeze-dried samples.

  16. Air quality impact of the coal-fired power plants in the northern passageway of the China West-East Power Transmission Project.

    PubMed

    Xue, Zhigang; Hao, Jiming; Chai, Fahe; Duan, Ning; Chen, Yizhen; Li, Jindan; Chen, Fu; Liu, Simei; Pu, Wenqing

    2005-12-01

    This paper analyzes the air quality impacts of coal-fired power plants in the northern passageway of the West-East Power Transmission Project in China. A three-layer Lagrangian model called ATMOS, was used to simulate the spatial distribution of incremental sulfur dioxide (SO2) and coarse particulate matter (PM10) concentrations under different emission control scenarios. In the year 2005, the emissions from planned power plants mainly affected the air quality of Shanxi, Shaanxi, the common boundary of Inner Mongolia and Shanxi, and the area around the boundary between Inner Mongolia and Ningxia. In these areas, the annually averaged incremental SO2 and PM10 concentrations exceed 2 and 2.5 microg/m3, respectively. The maximum increases of the annually averaged SO2 and PM10 concentrations are 8.3 and 7.2 microg/m3, respectively, which occur around Hancheng city, near the boundary of the Shaanxi and Shanxi provinces. After integrated control measures are considered, the maximum increases of annually averaged SO2 and PM10 concentrations fall to 4.9 and 4 microg/m3, respectively. In the year 2010, the areas affected by planned power plants are mainly North Shaanxi, North Ningxia, and Northwest Shanxi. The maximum increases of the annually averaged SO2 and PM10, concentrations are, respectively, 6.3 and 5.6 microg/m3, occurring in Northwest Shanxi, which decline to 4.4 and 4.1 microg/m3 after the control measures are implemented. The results showed that the proposed power plants mainly affect the air quality of the region where the power plants are built, with little impact on East China where the electricity will be used. The influences of planned power plants on air quality will be decreased greatly by implementing integrated control measures.

  17. Power and the Association with Relationship Quality in South African Couples: Implications for HIV/AIDS Interventions

    PubMed Central

    Conroy, Amy A.; McGrath, Nuala; van Rooyen, Heidi; Hosegood, Victoria; Johnson, Mallory O.; Fritz, Katherine; Marr, Alexander; Ngubane, Thulani; Darbes, Lynae A.

    2016-01-01

    Introduction Power imbalances within sexual relationships have significant implications for HIV prevention in sub-Saharan Africa. Little is known about how power influences the quality of a relationship, which could be an important pathway leading to healthy behavior around HIV/AIDS. Methods This paper uses data from 448 heterosexual couples (896 individuals) in rural KwaZulu-Natal, South Africa who completed baseline surveys from 2012–2014 as part of a couples-based HIV intervention trial. Using an actor-partner interdependence perspective, we assessed: (1) how both partners’ perceptions of power influences their own (i.e., actor effect) and their partner’s reports of relationship quality (i.e., partner effect); and (2) whether these associations differed by gender. We examined three constructs related to power (female power, male equitable gender norms, and shared power) and four domains of relationship quality (intimacy, trust, mutually constructive communication, and conflict). Results For actor effects, shared power was strongly and consistently associated with higher relationship quality across all four domains. The effect of shared power on trust, mutually constructive communication, and conflict were stronger for men than women. The findings for female power and male equitable gender norms were more mixed. Female power was positively associated with women’s reports of trust and mutually constructive communication, but negatively associated with intimacy. Male equitable gender norms were positively associated with men’s reports of mutually constructive communication. For partner effects, male equitable gender norms were positively associated with women’s reports of intimacy and negatively associated with women’s reports of conflict. Conclusions Research and health interventions aiming to improving HIV-related behaviors should consider sources of shared power within couples and potential leverage points for empowerment at the couple level

  18. Power and the association with relationship quality in South African couples: Implications for HIV/AIDS interventions.

    PubMed

    Conroy, Amy A; McGrath, Nuala; van Rooyen, Heidi; Hosegood, Victoria; Johnson, Mallory O; Fritz, Katherine; Marr, Alexander; Ngubane, Thulani; Darbes, Lynae A

    2016-03-01

    Power imbalances within sexual relationships have significant implications for HIV prevention in sub-Saharan Africa. Little is known about how power influences the quality of a relationship, which could be an important pathway leading to healthy behavior around HIV/AIDS. This paper uses data from 448 heterosexual couples (896 individuals) in rural KwaZulu-Natal, South Africa who completed baseline surveys from 2012 to 2014 as part of a couples-based HIV intervention trial. Using an actor-partner interdependence perspective, we assessed: (1) how both partners' perceptions of power influences their own (i.e., actor effect) and their partner's reports of relationship quality (i.e., partner effect); and (2) whether these associations differed by gender. We examined three constructs related to power (female power, male equitable gender norms, and shared power) and four domains of relationship quality (intimacy, trust, mutually constructive communication, and conflict). For actor effects, shared power was strongly and consistently associated with higher relationship quality across all four domains. The effect of shared power on trust, mutually constructive communication, and conflict were stronger for men than women. The findings for female power and male equitable gender norms were more mixed. Female power was positively associated with women's reports of trust and mutually constructive communication, but negatively associated with intimacy. Male equitable gender norms were positively associated with men's reports of mutually constructive communication. For partner effects, male equitable gender norms were positively associated with women's reports of intimacy and negatively associated with women's reports of conflict. Research and health interventions aiming to improving HIV-related behaviors should consider sources of shared power within couples and potential leverage points for empowerment at the couple level. Efforts solely focused on empowering women should also

  19. Sleep disturbances and insulin resistance.

    PubMed

    Van Cauter, E

    2011-12-01

    The causes and risk factors of insulin resistance remain insufficiently understood. After taking into account the important roles of adiposity, age, sex and race/ethnicity, up to 50% of the individual variability in insulin resistance remains unexplained. In recent years, evidence has accumulated to support a role for sleep disturbances, including insufficient sleep, poor sleep quality and insomnia, and obstructive sleep apnoea, as independent risk factors for the development and exacerbation of insulin resistance. The present review summarizes the evidence. We will start with a brief introduction to sleep and its disorders and then examine in succession the role of the three major types of sleep disturbances of modern society, namely insufficient sleep, poor sleep quality and/or insomnia and obstructive sleep apnoea. Insulin resistance is a hallmark of the polycystic ovary syndrome, the most common endocrine pathology in women, and the last section of this review will discuss the role of obstructive sleep apnoea in the insulin resistance and metabolic disturbances of polycystic ovary syndrome. © 2011 The Author. Diabetic Medicine © 2011 Diabetes UK.

  20. Transmission intensity disturbance in a rotating polarizer

    NASA Astrophysics Data System (ADS)

    Fan, J. Y.; Li, H. X.; Wu, F. Q.

    2008-01-01

    Random disturbance was observed in transmission intensity in various rotating prism polarizers when they were used in optical systems. As a result, the transmitted intensity exhibited cyclic significant deviation from the Malus cosine-squared law with rotation of prisms. The disturbance spoils the light quality transmitted through the polarizer thus dramatically depresses the accuracies of measurements when the prim polarizers were used in light path. A rigorous model is presented based on the solid basis of multi-beams interference, and theoretical results show good agreement with measured values and also indicate effective method for reducing the disturbance.

  1. Electric utility industry experience with geomagnetic disturbances

    SciTech Connect

    Barnes, P.R.; Rizy, D.T.; McConnell, B.W. ); Taylor, E.R. Jr. ); Tesche, F.M.

    1991-09-01

    A geomagnetic disturbance (GMD) by its nature occurs globally and almost simultaneously. Severe geomagnetic storms cause problems for electric power systems. The vulnerability of electric power systems to such events has apparently increased during the last 10 to 20 years because power system transmission lines have become more interconnected and have increased in length and because power systems are now operated closer to their limits than in the past. In this report, the experience of electric utilities during geomagnetic storms is examined and analyzed. Measured data, effects on power system components, and power system impacts are considered. It has been found that electric power systems are susceptible to geomagnetically induced earth-surface potential gradients as small as few (2 to 3) volts per kilometer, corresponding to a storm of K-6 intensity over an area of high earth resistivity. The causes and effects are reasonably well understood, but additional research is needed to develop a better understanding of solar-induced geomagnetic storms and the responses of power systems to these types of storms. A better understanding of geomagnetic storms and the power systems' responses to GMDs is needed so that mitigation measures can be implemented that will make power systems less susceptible to severe geomagnetic disturbances. A GMD caused by a large high-altitude nuclear detonation is similar in many ways to that of solar-induced geomagnetic storms except that a nuclear-caused disturbance would be much more intense with a far shorter duration. 49 refs.

  2. Electric utility industry experience with geomagnetic disturbances

    SciTech Connect

    Barnes, P.R.; Rizy, D.T.; McConnell, B.W.; Taylor, E.R. Jr.; Tesche, F.M.

    1991-09-01

    A geomagnetic disturbance (GMD) by its nature occurs globally and almost simultaneously. Severe geomagnetic storms cause problems for electric power systems. The vulnerability of electric power systems to such events has apparently increased during the last 10 to 20 years because power system transmission lines have become more interconnected and have increased in length and because power systems are now operated closer to their limits than in the past. In this report, the experience of electric utilities during geomagnetic storms is examined and analyzed. Measured data, effects on power system components, and power system impacts are considered. It has been found that electric power systems are susceptible to geomagnetically induced earth-surface potential gradients as small as few (2 to 3) volts per kilometer, corresponding to a storm of K-6 intensity over an area of high earth resistivity. The causes and effects are reasonably well understood, but additional research is needed to develop a better understanding of solar-induced geomagnetic storms and the responses of power systems to these types of storms. A better understanding of geomagnetic storms and the power systems` responses to GMDs is needed so that mitigation measures can be implemented that will make power systems less susceptible to severe geomagnetic disturbances. A GMD caused by a large high-altitude nuclear detonation is similar in many ways to that of solar-induced geomagnetic storms except that a nuclear-caused disturbance would be much more intense with a far shorter duration. 49 refs.

  3. Electric Utility Industry Experience with Geomagnetic Disturbances

    SciTech Connect

    Barnes, P.R.

    1991-01-01

    A geomagnetic disturbance (GMD) by its nature occurs globally and almost simultaneously. Severe geomagnetic storms cause problems for electric power systems. The vulnerability of electric power systems to such events has apparently increased during the last 10 to 20 years because power system transmission lines have become more interconnected and have increased in length and because power systems are now operated closer to their limits than in the past. In this report, the experience of electric utilities during geomagnetic storms is examined and analyzed. Measured data, effects on power system components, and power system impacts are considered. It has been found that electric power systems are susceptible to geomagnetically induced earth-surface potential gradients as small as a few (2 to 3) volts per kilometer, corresponding to a storm of K-6 intensity over an area of high earth resistivity. The causes and effects are reasonably well understood, but additional research is needed to develop a better understanding of solar-induced geomagnetic storms and the responses of power systems to these types of storms. A better understanding of geomagnetic storms and the power systems' responses to GMDs is needed so that mitigation measures can be implemented that will make power systems less susceptible to severe geomagnetic disturbances. A GMD caused by a large high-altitude nuclear detonation is similar in many ways to that of solar-induced geomagnetic storms except that a nuclear-caused disturbance would be much more intense with a far shorter duration.

  4. Natural disturbance production functions

    Treesearch

    Jeffrey P. Prestemon; D. Evan Mercer; John M. Pye

    2008-01-01

    Natural disturbances in forests are driven by physical and biological processes. Large, landscape scale disturbances derive primarily from weather (droughts, winds, ice storms, and floods), geophysical activities (earthquakes, volcanic eruptions), fires, insects, and diseases. Humans have invented ways to minimize their negative impacts and reduce their rates of...

  5. Modelling and Simulation of Single-Phase Series Active Compensator for Power Quality Improvement

    NASA Astrophysics Data System (ADS)

    Verma, Arun Kumar; Mathuria, Kirti; Singh, Bhim; Bhuvaneshwari, G.

    2016-10-01

    A single-phase active series compensator is proposed in this work to reduce harmonic currents at the ac mains and to regulate the dc link voltage of a diode bridge rectifier (DBR) that acts as the front end converter for a voltage source inverter feeding an ac motor. This ac motor drive is used in any of the domestic, commercial or industrial appliances. Under fluctuating ac mains voltages, the dc link voltage of the DBR depicts wide variations and hence the ac motor is used at reduced rating as compared to its name-plate rating. The active series compensator proposed here provides dual functions of improving the power quality at the ac mains and regulating the dc link voltage thus averting the need for derating of the ac motor.

  6. A Control Law Design Method Facilitating Control Power, Robustness, Agility, and Flying Qualities Tradeoffs: CRAFT

    NASA Technical Reports Server (NTRS)

    Murphy, Patrick C.; Davidson, John B.

    1998-01-01

    A multi-input, multi-output control law design methodology, named "CRAFT", is presented. CRAFT stands for the design objectives addressed, namely, Control power, Robustness, Agility, and Flying Qualities Tradeoffs. The methodology makes use of control law design metrics from each of the four design objective areas. It combines eigenspace assignment, which allows for direct specification of eigenvalues and eigenvectors, with a graphical approach for representing the metrics that captures numerous design goals in one composite illustration. Sensitivity of the metrics to eigenspace choice is clearly displayed, enabling the designer to assess the cost of design tradeoffs. This approach enhances the designer's ability to make informed design tradeoffs and to reach effective final designs. An example of the CRAFT methodology applied to an advanced experimental fighter and discussion of associated design issues are provided.

  7. Beam quality of InGaAs ridge lasers at high output power.

    PubMed

    Hunziker, G; Harder, C

    1995-09-20

    The nonlinear behavior of the light-current characteristic of single quantum well, graded-index-separateheterostructure ridge laser diodes emitting at 980 nm is investigated. We have measured the beam-quality factor |M|(2) as a function of the output power, under continuous-wave and transient conditions.The time constant associated with beam degradation under the transient condition suggests that the temperature profile in the cavity plays a significant role in the lateral guiding of the lasing modes. The two-dimensional heat equation is solved for the device, and the time-resolved thermally induced refractive-index profile is computed. There is excellent agreement between the time required to reach a steady index profile and that required to degrade the beam. The small beam astigmatism (typically 2 µm) measured under CW operating conditions in the linear regime indicates that the mode is essentially index guided, which permits simple quantitative modeling of the waveguide.

  8. Quality assurance considerations for the implementation of a pulsed power R and D project

    NASA Astrophysics Data System (ADS)

    Furaus, J. P.; Barr, G. W.; Shirley, C. G.

    The second generation Particle Beam Fusion Accelerator (PBFA II) at Sandia National Laboratories (SNLA) is a $48.15M construction project that includes conventional facilities such as buildings as well as state-of-the-art pulsed power designs and special support systems. The project also includes considerations for longer term program goals, such as breakeven fusion reactions. This project started in May 1980 and is scheduled for completion in January 1986. Implementation of Quality Assurance (QA) policies, techniques and programs, although not a straightforward problem for this complex project, has been effective as demonstrated by progress thus far. The discussion will describe key features of the QA program, their implementation and the results.

  9. Improving Power Quality and Distribution Efficiency in Micro-Grids by Plug & Play Control of Switching Power Interfaces

    NASA Astrophysics Data System (ADS)

    Tenti, Paolo; Costabeber, Alessandro; Mattavelli, Paolo

    Smart grids offer a wide application domain for power electronics. In fact, every distributed generator (DG) includes an electronic power processor (Switching Power Interface, SPI) which controls the currents drawn from the grid and can be driven to optimize the power flow, improve voltage stability and increase distribution efficiency. For these aims, such distributed SPIs must perform cooperatively. This is true also in low-voltage residential micro-grids, where the number of active DGs and the generated power may vary during daytime, thus requiring dynamic adaptation of SPI operation. To achieve this goal different approaches can be adopted, depending on the available communication capability. This paper discusses various control solutions applicable in absence of supervisory control, e. g., in residential micro-grids, where communication is possible between neighbor units only (surround control) or is not available at all (plug & play control).

  10. Image simulation and a model of noise power spectra across a range of mammographic beam qualities

    SciTech Connect

    Mackenzie, Alistair Dance, David R.; Young, Kenneth C.; Diaz, Oliver

    2014-12-15

    Purpose: The aim of this work is to create a model to predict the noise power spectra (NPS) for a range of mammographic radiographic factors. The noise model was necessary to degrade images acquired on one system to match the image quality of different systems for a range of beam qualities. Methods: Five detectors and x-ray systems [Hologic Selenia (ASEh), Carestream computed radiography CR900 (CRc), GE Essential (CSI), Carestream NIP (NIPc), and Siemens Inspiration (ASEs)] were characterized for this study. The signal transfer property was measured as the pixel value against absorbed energy per unit area (E) at a reference beam quality of 28 kV, Mo/Mo or 29 kV, W/Rh with 45 mm polymethyl methacrylate (PMMA) at the tube head. The contributions of the three noise sources (electronic, quantum, and structure) to the NPS were calculated by fitting a quadratic at each spatial frequency of the NPS against E. A quantum noise correction factor which was dependent on beam quality was quantified using a set of images acquired over a range of radiographic factors with different thicknesses of PMMA. The noise model was tested for images acquired at 26 kV, Mo/Mo with 20 mm PMMA and 34 kV, Mo/Rh with 70 mm PMMA for three detectors (ASEh, CRc, and CSI) over a range of exposures. The NPS were modeled with and without the noise correction factor and compared with the measured NPS. A previous method for adapting an image to appear as if acquired on a different system was modified to allow the reference beam quality to be different from the beam quality of the image. The method was validated by adapting the ASEh flat field images with two thicknesses of PMMA (20 and 70 mm) to appear with the imaging characteristics of the CSI and CRc systems. Results: The quantum noise correction factor rises with higher beam qualities, except for CR systems at high spatial frequencies, where a flat response was found against mean photon energy. This is due to the dominance of secondary quantum noise

  11. High-power terahertz lasers with excellent beam quality for local oscillator sources

    NASA Astrophysics Data System (ADS)

    Williams, Benjamin

    Many molecular species that compose the interstellar medium have strong spectral features in the 2-5 THz range, and heterodyne spectroscopy is required to obtain ~km/s velocity resolution to resolve their complicated lineshapes and disentangle them from the background. Understanding the kinetics and energetics within the gas clouds of the interstellar medium is critical to understanding star formation processes and validating theories of galactic evolution. Herschel Observatory's heterodyne HIFI instrument provided several years of high-spectral-resolution measurements of the interstellar medium, although only up to 1.9 THz. The next frontier for heterodyne spectroscopy is the 2-6 THz region. However, development of heterodyne receivers above 2 THz has been severely hindered by a lack of convenient coherent sources of sufficient power to serve as local oscillators (LOs). The recently developed quantum-cascade (QC) lasers are emerging as candidates for LOs in the 1.5-5 THz range. The current generation of single-mode THz QC-lasers can provide a few milliwatts of power in a directive beam, and will be sufficient to pump single pixels and small-format heterodyne arrays (~10 elements). This proposal looks beyond the state-of-the-art, to the development of large format heterodyne arrays which contain on the order of 100-1000 elements. LO powers on the order of 10-100 mW delivered in a high-quality Gaussian beam will be needed to pump the mixer array - not only because of the microwatt mixer power requirement, but to account for large anticipated losses in LO coupling and distribution. Large format heterodyne array instruments are attractive for a dramatic speedup of mapping of the interstellar medium, particularly on airborne platforms such as the Stratospheric Observatory for Infrared Astronomy (SOFIA), and on long duration balloon platforms such as the Stratospheric Terahertz Observatory (STO), where observation time is limited. The research goal of this proposal is

  12. The impact of hybrid energy storage on power quality, when high power pulsed DC loads are operated on a microgrid testbed

    NASA Astrophysics Data System (ADS)

    Kelley, Jay Paul

    . This enables the generator to maintain its operation at levels of high efficiency thereby increasing the power quality of the AC bus. The work discussed here is aimed at evaluating how the use of energy storage impacts the power quality on MicroGrid's AC bus when high rate DC and AC loads are sourced simultaneously. Also HESM has been developed and evaluated as a mean to optimizing both the power and energy density of the energy storage installed.

  13. Coal-fired power generaion, new air quality regulations, and future U.S. coal production

    USGS Publications Warehouse

    Attanasi, E.D.; Root, D.H.

    1999-01-01

    Tighter new regulation of stack gas emissions and competition in power generation are driving electrical utilities to demand cleaner, lower sulfur coal. Historical data on sulfur content of produced coals shows little variability in coal quality for individual mines and individual coal-producing counties over relatively long periods of time. If coal-using power generators follow the compliance patterns established in Phase I of the 1990 Clean Air Act Amendments, then the industry's response to the tighter Phase II emissions standards will result in large amounts of coal production shifting from higher sulfur areas to areas with lower cost low sulfur coal. One reason this shift will likely occur is that currently only 30% of U.S. coal-fired electrical generating capacity is equipped with flue-gas scrubbers. In 1995, coal mines in the higher sulfur areas of the Illinois Basin and Northern and Central Appalachia employed 78% of all coal miners (>70,000 miners). A substantial geographical redistribution of the nation's coal supplies will likely lead to economic dislocations that will reach beyond local coal-producing areas.

  14. CMOS Amperometric ADC With High Sensitivity, Dynamic Range and Power Efficiency for Air Quality Monitoring.

    PubMed

    Li, Haitao; Boling, C Sam; Mason, Andrew J

    2016-08-01

    Airborne pollutants are a leading cause of illness and mortality globally. Electrochemical gas sensors show great promise for personal air quality monitoring to address this worldwide health crisis. However, implementing miniaturized arrays of such sensors demands high performance instrumentation circuits that simultaneously meet challenging power, area, sensitivity, noise and dynamic range goals. This paper presents a new multi-channel CMOS amperometric ADC featuring pixel-level architecture for gas sensor arrays. The circuit combines digital modulation of input currents and an incremental Σ∆ ADC to achieve wide dynamic range and high sensitivity with very high power efficiency and compact size. Fabricated in 0.5 [Formula: see text] CMOS, the circuit was measured to have 164 dB cross-scale dynamic range, 100 fA sensitivity while consuming only 241 [Formula: see text] and 0.157 [Formula: see text] active area per channel. Electrochemical experiments with liquid and gas targets demonstrate the circuit's real-time response to a wide range of analyte concentrations.

  15. Mechanical sampling systems for coal quality control in Romanian power plants

    SciTech Connect

    Matei, M.

    1998-12-31

    According to ISO 1988 samples must be taken from moving currents by using certain mechanical devices, and, only, exceptionally, by an understanding between party`s, by manually sampling. The principal requirements when designing and constructing a mechanical sampling system are that: it shall be capable of collecting and preparing increments or samples, as the case may be, that are free from relevant bias; it shall maintain this capability under all such conditions of sampling that are stipulated in the relevant specifications and without necessitating that sampling be interrupted for cleaning or maintenance. Actually, coal quality control in Romanian power plants are usually performed by a manual system. In order to meet ISO 1988 requirements, RENEL-GSCI (formerly ICEMENERG) has designed and achieved a falling stream sampler with cutter bucket in accordance with ISO 9411-1 (solid mineral fuels - Mechanical sampling from moving stream) provisions. This device has been installed in the Oradea 2 cogeneration power plant in the coal falling stream at the end of the belt conveyor. When the mechanical sampling installation was commissioned, experiments to check for precision and bias had been out for the installation as a whole. The method of checking for bias was by comparison with stopped-belt sampling. The mechanical sampling device is still under testing. The paper presents the result obtained during the preliminary test period in order to certify the mechanical sampler.

  16. CMOS Amperometric ADC with High Sensitivity, Dynamic Range and Power Efficiency for Air Quality Monitoring

    PubMed Central

    Li, Haitao; Boling, Sam; Mason, Andrew J.

    2016-01-01

    Airborne pollutants are a leading cause of illness and mortality globally. Electrochemical gas sensors show great promise for personal air quality monitoring to address this worldwide health crisis. However, implementing miniaturized arrays of such sensors demands high performance instrumentation circuits that simultaneously meet challenging power, area, sensitivity, noise and dynamic range goals. This paper presents a new multi-channel CMOS amperometric ADC featuring pixel-level architecture for gas sensor arrays. The circuit combines digital modulation of input currents and an incremental ΣΔ ADC to achieve wide dynamic range and high sensitivity with very high power efficiency and compact size. Fabricated in 0.5 μm CMOS, the circuit was measured to have 164 dB cross-scale dynamic range, 100 fA sensitivity while consuming only 241 μW and 0.157mm2 active area per channel. Electrochemical experiments with liquid and gas targets demonstrate the circuit’s real-time response to a wide range of analyte concentrations. PMID:27352395

  17. [The effect of thermal power plant on microbial ecology and environmental quality].

    PubMed

    Yang, S S; Yang, C K; Chang, E H; Wei, C B

    1999-12-01

    To investigate the effect of thermal power plant on the microbial ecology and the environmental quality, the Hsieh-Ho Thermal Power Plant was chosen and the populations of microbes including bacteria, actinomycetes, fungi, and cellulolytic, phosphate-solubilizing and nitrogen-fixing microbes were selected as the parameters of microbial ecology. The pH values of the soil sample collected from inside and outside of the plant were 5.2-6.2 and 4.0-5.3, respectively. Moisture content in plant area was lower than that in the surrounding area. Microbial populations of the topsoils were higher than those of the subsoils. Each gram of soil contained 3.64 x 10(4)-5.16 x 10(7) colonies of bacteria, 1.75 x 10(3)-1.10 x 10(6) colonies of actinomycetes and 6.72 x 10(3)-8.78 x 10(6) colonies of fungi in the plant area; while they were 5.52 x 10(4)-2.14 x 10(7), 8.26 x 10(3)-7.25 x 10(5) and 3.49 x 10(3)-2.74 x 10(6) colonies of bacteria, actinomycetes and fungi, respectively, in the surrounding area. The effect of seasonal change on microbial populations was not significant. The ratio of cellulolytic, phosphate-solubilizing and nitrogen-fixing microbes to the total count in the plant area was also higher than that in the surrounding area, and some of them had significant differences. From the statistical analysis, the effect of thermal power generator on the population and distribution of microbes was significantly different.

  18. Development of Real Time Implementation of 5/5 Rule based Fuzzy Logic Controller Shunt Active Power Filter for Power Quality Improvement

    NASA Astrophysics Data System (ADS)

    Puhan, Pratap Sekhar; Ray, Pravat Kumar; Panda, Gayadhar

    2016-12-01

    This paper presents the effectiveness of 5/5 Fuzzy rule implementation in Fuzzy Logic Controller conjunction with indirect control technique to enhance the power quality in single phase system, An indirect current controller in conjunction with Fuzzy Logic Controller is applied to the proposed shunt active power filter to estimate the peak reference current and capacitor voltage. Current Controller based pulse width modulation (CCPWM) is used to generate the switching signals of voltage source inverter. Various simulation results are presented to verify the good behaviour of the Shunt active Power Filter (SAPF) with proposed two levels Hysteresis Current Controller (HCC). For verification of Shunt Active Power Filter in real time, the proposed control algorithm has been implemented in laboratory developed setup in dSPACE platform.

  19. The N-Pact Factor: Evaluating the Quality of Empirical Journals with Respect to Sample Size and Statistical Power

    PubMed Central

    Fraley, R. Chris; Vazire, Simine

    2014-01-01

    The authors evaluate the quality of research reported in major journals in social-personality psychology by ranking those journals with respect to their N-pact Factors (NF)—the statistical power of the empirical studies they publish to detect typical effect sizes. Power is a particularly important attribute for evaluating research quality because, relative to studies that have low power, studies that have high power are more likely to (a) to provide accurate estimates of effects, (b) to produce literatures with low false positive rates, and (c) to lead to replicable findings. The authors show that the average sample size in social-personality research is 104 and that the power to detect the typical effect size in the field is approximately 50%. Moreover, they show that there is considerable variation among journals in sample sizes and power of the studies they publish, with some journals consistently publishing higher power studies than others. The authors hope that these rankings will be of use to authors who are choosing where to submit their best work, provide hiring and promotion committees with a superior way of quantifying journal quality, and encourage competition among journals to improve their NF rankings. PMID:25296159

  20. Power plant fuel switching and air quality in a tropical, forested environment

    NASA Astrophysics Data System (ADS)

    Medeiros, Adan S. S.; Calderaro, Gisele; Guimarães, Patricia C.; Magalhaes, Mateus R.; Morais, Marcos V. B.; Rafee, Sameh A. A.; Ribeiro, Igor O.; Andreoli, Rita V.; Martins, Jorge A.; Martins, Leila D.; Martin, Scot T.; Souza, Rodrigo A. F.

    2017-07-01

    How a changing energy matrix for electricity production affects air quality is considered for an urban region in a tropical, forested environment. Manaus, the largest city in the central Amazon Basin of Brazil, is in the process of changing its energy matrix for electricity production from fuel oil and diesel to natural gas over an approximately 10-year period, with a minor contribution by hydropower. Three scenarios of urban air quality, specifically afternoon ozone concentrations, were simulated using the Weather Research and Forecasting (WRF-Chem) model. The first scenario used fuel oil and diesel for electricity production, which was the reality in 2008. The second scenario was based on the fuel mix from 2014, the most current year for which data were available. The third scenario considered nearly complete use of natural gas for electricity production, which is the anticipated future, possibly for 2018. For each case, inventories of anthropogenic emissions were based on electricity generation, refinery operations, and transportation. Transportation and refinery operations were held constant across the three scenarios to focus on effects of power plant fuel switching in a tropical context. The simulated NOx and CO emissions for the urban region decrease by 89 and 55 %, respectively, after the complete change in the energy matrix. The results of the simulations indicate that a change to natural gas significantly decreases maximum afternoon ozone concentrations over the population center, reducing ozone by > 70 % for the most polluted days. The sensitivity of ozone concentrations to the fuel switchover is consistent with a NOx-limited regime, as expected for a tropical forest having high emissions of biogenic volatile organic compounds, high water vapor concentrations, and abundant solar radiation. There are key differences in a shifting energy matrix in a tropical, forested environment compared to other world environments. Policies favoring the burning of

  1. Self-powered, autonomous Biological Oxygen Demand biosensor for online water quality monitoring.

    PubMed

    Pasternak, Grzegorz; Greenman, John; Ieropoulos, Ioannis

    2017-06-01

    Standard Biological Oxygen Demand (BOD) analysis requires 5 days to complete. To date, microbial fuel cell biosensors used as an alternative method for BOD assessment requires external apparatus, which limits their use for on-line monitoring in remote, off-grid locations. In this study, a self-powered, floating biosensor was developed for online water quality monitoring. This approach eliminated the need for external apparatus and maintenance that would otherwise be required by other techniques. The biosensor was able to detect urine in freshwater and turn ON a visual and sound cues (85 dB). The energy needed to operate the biosensor was produced by the system itself with the use of electroactive microorganisms, inside microbial fuel cells. The Chemical Oxygen Demand (COD) was used as a fast method of biosensor validation. When urine concentration exceeded the lower threshold, corresponding to a COD concentration of 57.7 ± 4.8 mgO2 L(-1), the biosensor turned the alarm ON. The shortest observed actuation time, required to switch ON the alarm was 61 min, when the urine concentration was 149.7 ± 1.7 mgO2 L(-1). Once the sensor was switched ON, the signal was emitted until the urine organic load decreased to 15.3 ± 1.9 mgO2 L(-1). When ON, the microbial fuel cell sensor produced a maximum power of 4.3 mW. When switched OFF, the biosensor produced 25.4 μW. The frequency of the signal was proportional to the concentration of urine. The observed frequencies varied between 0.01 and 0.59 Hz. This approach allowed to correlate and quantitatively detect the presence of water contamination, based on signal frequency. The sensor was operating autonomously for 5 months. This is the first report of a self-powered, autonomous device, developed for online water quality monitoring.

  2. Use of local noise power spectrum and wavelet analysis in quantitative image quality assurance for EPIDs.

    PubMed

    Lee, Soyoung; Yan, Guanghua; Bassett, Philip; Gopal, Arun; Samant, Sanjiv

    2016-09-01

    To investigate the use of local noise power spectrum (NPS) to characterize image noise and wavelet analysis to isolate defective pixels and inter-subpanel flat-fielding artifacts for quantitative quality assurance (QA) of electronic portal imaging devices (EPIDs). A total of 93 image sets including custom-made bar-pattern images and open exposure images were collected from four iViewGT a-Si EPID systems over three years. Global quantitative metrics such as modulation transform function (MTF), NPS, and detective quantum efficiency (DQE) were computed for each image set. Local NPS was also calculated for individual subpanels by sampling region of interests within each subpanel of the EPID. The 1D NPS, obtained by radially averaging the 2D NPS, was fitted to a power-law function. The r-square value of the linear regression analysis was used as a singular metric to characterize the noise properties of individual subpanels of the EPID. The sensitivity of the local NPS was first compared with the global quantitative metrics using historical image sets. It was then compared with two commonly used commercial QA systems with images collected after applying two different EPID calibration methods (single-level gain and multilevel gain). To detect isolated defective pixels and inter-subpanel flat-fielding artifacts, Haar wavelet transform was applied on the images. Global quantitative metrics including MTF, NPS, and DQE showed little change over the period of data collection. On the contrary, a strong correlation between the local NPS (r-square values) and the variation of the EPID noise condition was observed. The local NPS analysis indicated image quality improvement with the r-square values increased from 0.80 ± 0.03 (before calibration) to 0.85 ± 0.03 (after single-level gain calibration) and to 0.96 ± 0.03 (after multilevel gain calibration), while the commercial QA systems failed to distinguish the image quality improvement between the two calibration methods. With

  3. Neural Network based Control of SG based Standalone Generating System with Energy Storage for Power Quality Enhancement

    NASA Astrophysics Data System (ADS)

    Nayar, Priya; Singh, Bhim; Mishra, Sukumar

    2017-08-01

    An artificial intelligence based control algorithm is used in solving power quality problems of a diesel engine driven synchronous generator with automatic voltage regulator and governor based standalone system. A voltage source converter integrated with a battery energy storage system is employed to mitigate the power quality problems. An adaptive neural network based signed regressor control algorithm is used for the estimation of the fundamental component of load currents for control of a standalone system with load leveling as an integral feature. The developed model of the system performs accurately under varying load conditions and provides good dynamic response to the step changes in loads. The real time performance is achieved using MATLAB along with simulink/simpower system toolboxes and results adhere to an IEEE-519 standard for power quality enhancement.

  4. Neural Network based Control of SG based Standalone Generating System with Energy Storage for Power Quality Enhancement

    NASA Astrophysics Data System (ADS)

    Nayar, Priya; Singh, Bhim; Mishra, Sukumar

    2016-09-01

    An artificial intelligence based control algorithm is used in solving power quality problems of a diesel engine driven synchronous generator with automatic voltage regulator and governor based standalone system. A voltage source converter integrated with a battery energy storage system is employed to mitigate the power quality problems. An adaptive neural network based signed regressor control algorithm is used for the estimation of the fundamental component of load currents for control of a standalone system with load leveling as an integral feature. The developed model of the system performs accurately under varying load conditions and provides good dynamic response to the step changes in loads. The real time performance is achieved using MATLAB along with simulink/simpower system toolboxes and results adhere to an IEEE-519 standard for power quality enhancement.

  5. Pilot evaluation of electricity-reliability and power-quality monitoring in California's Silicon Valley with the I-Grid(R) system

    SciTech Connect

    Eto, Joseph; Divan, Deepak; Brumsickle, William

    2004-02-01

    Power-quality events are of increasing concern for the economy because today's equipment, particularly computers and automated manufacturing devices, is susceptible to these imperceptible voltage changes. A small variation in voltage can cause this equipment to shut down for long periods, resulting in significant business losses. Tiny variations in power quality are difficult to detect except with expensive monitoring equipment used by trained technicians, so many electricity customers are unaware of the role of power-quality events in equipment malfunctioning. This report describes the findings from a pilot study coordinated through the Silicon Valley Manufacturers Group in California to explore the capabilities of I-Grid(R), a new power-quality monitoring system. This system is designed to improve the accessibility of power-quality in formation and to increase understanding of the growing importance of electricity reliability and power quality to the economy. The study used data collected by I-Grid sensors at seven Silicon Valley firms to investigate the impacts of power quality on individual study participants as well as to explore the capabilities of the I-Grid system to detect events on the larger electricity grid by means of correlation of data from the sensors at the different sites. In addition, study participants were interviewed about the value they place on power quality, and their efforts to address electricity-reliability and power-quality problems. Issues were identified that should be taken into consideration in developing a larger, potentially nationwide, network of power-quality sensors.

  6. Power quality control and design of power converter for variable-speed wind energy conversion system with permanent-magnet synchronous generator.

    PubMed

    Oğuz, Yüksel; Güney, İrfan; Çalık, Hüseyin

    2013-01-01

    The control strategy and design of an AC/DC/AC IGBT-PMW power converter for PMSG-based variable-speed wind energy conversion systems (VSWECS) operation in grid/load-connected mode are presented. VSWECS consists of a PMSG connected to a AC-DC IGBT-based PWM rectifier and a DC/AC IGBT-based PWM inverter with LCL filter. In VSWECS, AC/DC/AC power converter is employed to convert the variable frequency variable speed generator output to the fixed frequency fixed voltage grid. The DC/AC power conversion has been managed out using adaptive neurofuzzy controlled inverter located at the output of controlled AC/DC IGBT-based PWM rectifier. In this study, the dynamic performance and power quality of the proposed power converter connected to the grid/load by output LCL filter is focused on. Dynamic modeling and control of the VSWECS with the proposed power converter is performed by using MATLAB/Simulink. Simulation results show that the output voltage, power, and frequency of VSWECS reach to desirable operation values in a very short time. In addition, when PMSG based VSWECS works continuously with the 4.5 kHz switching frequency, the THD rate of voltage in the load terminal is 0.00672%.

  7. Power Quality Control and Design of Power Converter for Variable-Speed Wind Energy Conversion System with Permanent-Magnet Synchronous Generator

    PubMed Central

    Oğuz, Yüksel; Güney, İrfan; Çalık, Hüseyin

    2013-01-01

    The control strategy and design of an AC/DC/AC IGBT-PMW power converter for PMSG-based variable-speed wind energy conversion systems (VSWECS) operation in grid/load-connected mode are presented. VSWECS consists of a PMSG connected to a AC-DC IGBT-based PWM rectifier and a DC/AC IGBT-based PWM inverter with LCL filter. In VSWECS, AC/DC/AC power converter is employed to convert the variable frequency variable speed generator output to the fixed frequency fixed voltage grid. The DC/AC power conversion has been managed out using adaptive neurofuzzy controlled inverter located at the output of controlled AC/DC IGBT-based PWM rectifier. In this study, the dynamic performance and power quality of the proposed power converter connected to the grid/load by output LCL filter is focused on. Dynamic modeling and control of the VSWECS with the proposed power converter is performed by using MATLAB/Simulink. Simulation results show that the output voltage, power, and frequency of VSWECS reach to desirable operation values in a very short time. In addition, when PMSG based VSWECS works continuously with the 4.5 kHz switching frequency, the THD rate of voltage in the load terminal is 0.00672%. PMID:24453905

  8. Effects of an intervention with drinking chamomile tea on sleep quality and depression in sleep disturbed postnatal women: a randomized controlled trial.

    PubMed

    Chang, Shao-Min; Chen, Chung-Hey

    2016-02-01

    The purpose of this study was to evaluate the effects of chamomile tea on sleep quality, fatigue and depression in postpartum women. Sleep quality is a significant issue for postnatal women. Chamomile is widely used as a folk remedy for its presumed sedative-hypnotic effects. A pretest-post-test randomized controlled trial was used. A total of 80 Taiwanese postnatal women with poor sleep quality (Postpartum Sleep Quality Scale; PSQS score ≧16) were recruited from November 2012-August 2013. They were systematically assigned, with a random start, to either the experimental group (n = 40) or the control group (n = 40). The participants in the experimental group were instructed to drink chamomile tea for a period of 2 weeks. The participants in the control group received regular postpartum care only. The PSQS, Edinburgh Postnatal Depression Scale, and Postpartum Fatigue Scale were used to assess outcomes. Two-sample t-tests were used to examine the mean differences in outcome variables between the two groups. Compared with the control group, the experimental group demonstrated significantly lower scores of physical-symptoms-related sleep inefficiency (t = -2·482, P = 0·015) and the symptoms of depression (t = -2·372, P = 0·020). However, the scores for all three instruments were similar for both groups at 4-week post-test, suggesting that the positive effects of chamomile tea were limited to the immediate term. Chamomile tea may be recommended to postpartum women as a supplementary approach to alleviating depression and sleep quality problems. © 2015 John Wiley & Sons Ltd.

  9. [Using alternative therapies in treating sleep disturbance].

    PubMed

    Hung, Hsuan-Man; Chen, Chung-Hey

    2011-02-01

    Sleep disturbance is a common health problem among adults, and enhancing sleep quality is an issue of significant importance to healthcare providers. As sleep quality worsens into insomnia, individuals may seek assistance from medication. However, sedative hypnotic drugs pose potentially adverse effects. Also, most medical treatments (e.g., positive pressure assistant ventilators) represent invasive interventions that must be prescribed by physicians. Non-pharmacological alternative therapies are commonly recommended and adopted by community nurses. Alternative therapies for sleep disturbance included exercise, cognitive behavior therapy, multiple strategies, music, and acupressure. In general, moderately intensive walking exercise is the intervention most recommended by professionals to help patients deal with sleep disturbance. Therefore, it is suggested that future researchers devise sleep quality promotion strategies that are suitable for home practice in order to apply the findings and spirit of research already done in this area.

  10. Disturbance and change in biodiversity

    PubMed Central

    Dornelas, Maria

    2010-01-01

    Understanding how disturbance affects biodiversity is important for both fundamental and applied reasons. Here, I investigate how disturbances with different ecological effects change biodiversity metrics. I define three main types of disturbance effects: D disturbance (shifts in mortality rate), B disturbance (shifts in reproductive rates) and K disturbance (shifts in carrying capacity). Numerous composite disturbances can be defined including any combination of these three types of ecological effects. The consequences of D, B and K disturbances, as well as of composite DBK disturbances are examined by comparing metrics before and after a disturbance, in disturbed and undisturbed communities. I use simulations of neutral communities and examine species richness, total abundance and species abundance distributions. The patterns of change in biodiversity metrics are consistent among different types of disturbance. K disturbance has the most severe effects, followed by D disturbance, and B disturbance has nearly negligible effects. Consequences of composite DBK disturbances are more complex than any of the three types of disturbance, with unimodal relationships along a disturbance gradient arising when D, B and K are negatively correlated. Importantly, regardless of disturbance type, community isolation enhances the negative consequences and hinders the positive effects of disturbances. PMID:20980319

  11. Disturbance and change in biodiversity.

    PubMed

    Dornelas, Maria

    2010-11-27

    Understanding how disturbance affects biodiversity is important for both fundamental and applied reasons. Here, I investigate how disturbances with different ecological effects change biodiversity metrics. I define three main types of disturbance effects: D disturbance (shifts in mortality rate), B disturbance (shifts in reproductive rates) and K disturbance (shifts in carrying capacity). Numerous composite disturbances can be defined including any combination of these three types of ecological effects. The consequences of D, B and K disturbances, as well as of composite DBK disturbances are examined by comparing metrics before and after a disturbance, in disturbed and undisturbed communities. I use simulations of neutral communities and examine species richness, total abundance and species abundance distributions. The patterns of change in biodiversity metrics are consistent among different types of disturbance. K disturbance has the most severe effects, followed by D disturbance, and B disturbance has nearly negligible effects. Consequences of composite DBK disturbances are more complex than any of the three types of disturbance, with unimodal relationships along a disturbance gradient arising when D, B and K are negatively correlated. Importantly, regardless of disturbance type, community isolation enhances the negative consequences and hinders the positive effects of disturbances.

  12. Disturbed island ecology.

    PubMed

    Whittaker, R J

    1995-10-01

    The natural occurrence of significant disturbances to the operation of insular ecosystems has tended to be downplayed in the development of island ecological theory. Despite the importance of events such as Hurricane Hugo, which in 1989 affected islands in the Caribbean, islands that are disturbed tend to be viewed as deviants from the `true path' described by equilibrium models. However, particularly with organisms of long generation times, it is questionable whether such models are applicable. This may be as important for wildlife managers to take account of as for theorists. Disturbance regime should be incorporated into island ecological models alongside other ecological factors structuring colonization patterns and turnover.

  13. Harmonics in a Wind Power Plant: Preprint

    SciTech Connect

    Preciado, V.; Madrigal, M.; Muljadi, E.; Gevorgian, V.

    2015-04-02

    Wind power generation has been growing at a very fast pace for the past decade, and its influence and impact on the electric power grid is significant. As in a conventional power plant, a wind power plant (WPP) must ensure that the quality of the power being delivered to the grid is excellent. At the same time, the wind turbine should be able to operate immune to small disturbances coming from the grid. Harmonics are one of the more common power quality issues presented by large WPPs because of the high switching frequency of the power converters and the possible nonlinear behavior from electric machines (generator, transformer, reactors) within a power plant. This paper presents a summary of the most important issues related to harmonics in WPPs and discusses practical experiences with actual Type 1 and Type 3 wind turbines in two WPPs.

  14. Linking water quality to water quantity: Integration of disturbance variables such as phytoplankton and turbidity into the management strategies of drinking water reservoirs

    NASA Astrophysics Data System (ADS)

    Rolinski, S.; Petzoldt, T.; Hillert, K.; Paul, L.; Benndorf, J.

    2007-12-01

    So far, seasonal management strategies for water withdrawal from drinking water reservoirs in Germany are based on the hydrological regime and use Monte-Carlo-simulations in order to provide recommendations with certain probability thresholds. Long-term experience on the annual development and composition of phytoplankton is used for ad-hoc adjustments in case of unexpected events. In the framework of the project INTEGTA ('Integrated management of reservoirs') knowledge on the biological and chemical freshwater ecosystem will be integrated into the widely used management system TALSIM. On the one hand, field studies on the reservoir system Klingenberg-Lehnmuehle are carried out in order to investigate the seasonal development and the dispersion of flood events in the major drinking water supply of Dresden, Saxony. The system consists of two closely linked reservoirs which are connected to other water storages so that many possibilities for water supply exist. In the year 2007, an early hot spring and lower than average precipitation resulted in a summerly water deficiency in Klingenberg reservoir which was met with increased supply with a time lag of one month. Though the inflowing water was of high quality and low temperature, the quality of the raw water could not be stabilized on the desired level and caused the request for an administrative fine. Thus, 2007 can be taken as a good example for studying the effect of delayed management activities. On the other hand, simulations by the coupled hydrodynamical ecological model SALMO will provide the basis to include water quality predictions into the decision system for the reservoir. Hydrological scenarios from the decision support system TALSIM are used as boundary conditions for the water quality model so that consistent predictions for the development of the water quantity and quality are derived. The output of the simulations are statistically analyzed with respect to (i) securing a sufficient water volume, (ii

  15. Crystal Quality and Light Output Power of GaN-Based LEDs Grown on Concave Patterned Sapphire Substrate.

    PubMed

    Wu, YewChung Sermon; Isabel, A Panimaya Selvi; Zheng, Jian-Hsuan; Lin, Bo-Wen; Li, Jhen-Hong; Lin, Chia-Chen

    2015-04-22

    The crystal quality and light output power of GaN-based light-emitting diodes (LEDs) grown on concave patterned sapphire substrate (CPSS) were investigated. It was found that the crystal quality of GaN-based LEDs grown on CPSS improved with the decrease of the pattern space (percentage of c-plane). However, when the pattern space decreased to 0.41 μm (S0.41-GaN), the GaN crystallinity dropped. On the other hand, the light output power of GaN-based LEDs was increased with the decrease of the pattern space due to the change of the light extraction efficiency.

  16. Power Quality Improvement in Bridgeless Ac-Dc Converter Based Multi-output Switched Mode Power Supply

    NASA Astrophysics Data System (ADS)

    Singh, Shihka; Singh, Bhim; Bhuvaneswari, G.; Bist, Vashist

    2014-12-01

    Computer power supplies are required to have multiple isolated regulated dc voltages with low ripple content and high input power factor at the utility interface. A dc-dc converter is used for obtaining these isolated multi-output dc voltages with excellent regulation. In this paper, a non-isolated ac-dc converter is proposed as the first stage converter to obtain a regulated dc output rather than using a simple uncontrolled diode bridge rectifier at the front end. A dc-dc converter is used at the second stage that has a high frequency transformer with multiple secondary windings to obtain different dc voltage levels at the output. The proposed bridgeless converter based power supply is designed using fundamental design equations, and different component values are calculated. Extensive simulations are carried out to demonstrate the improved performance of the proposed bridgeless converter based multi-output computer power supply at varying source voltages and load conditions. Experimental validation of the power supply is carried on a developed hardware prototype, and the test results are compared with the simulated performance for design verification.

  17. Assessing and Managing Sleep Disturbance in Patients with Chronic Pain.

    PubMed

    Cheatle, Martin D; Foster, Simmie; Pinkett, Aaron; Lesneski, Matthew; Qu, David; Dhingra, Lara

    2016-06-01

    Chronic pain is associated with symptoms that may impair a patient's quality of life, including emotional distress, fatigue, and sleep disturbance. There is a high prevalence of concomitant pain and sleep disturbance. Studies support the hypothesis that sleep and pain have a bidirectional and reciprocal relationship. Clinicians who manage patients with chronic pain often focus on interventions that relieve pain, and assessing and treating sleep disturbance are secondary or not addressed. This article reviews the literature on pain and co-occurring sleep disturbance, describes the assessment of sleep disturbance, and outlines nonpharmacologic and pharmacologic treatment strategies to improve sleep in patients with chronic pain.

  18. Indicators: Human Disturbance

    EPA Pesticide Factsheets

    Human disturbance is a measure of the vulnerability of aquatic resources to a variety of harmful human activities such as tree removal, road building, construction near shorelines/streambanks, and artificial hardening of lakeshores with retaining walls.

  19. Disturbances by Prometheus

    NASA Image and Video Library

    2006-09-05

    The clumpy disturbed appearance of the brilliant F ring constantly changes. The irregular structure of the ring is due, in large part, to the gravitational perturbations on the ring material by one of Saturn moons, Prometheus

  20. Sensory and Quality Evaluation of Traditional Compared with Power Ultrasound Processed Corn (Zea Mays) Tortilla Chips.

    PubMed

    Janve, Bhaskar; Yang, Wade; Sims, Charles

    2015-06-01

    Power ultrasound reduces the traditional corn steeping time from 18 to 1.5 h during tortilla chips dough (masa) processing. This study sought to examine consumer (n = 99) acceptability and quality of tortilla chips made from the masa by traditional compared with ultrasonic methods. Overall appearance, flavor, and texture acceptability scores were evaluated using a 9-point hedonic scale. The baked chips (process intermediate) before and after frying (finished product) were analyzed using a texture analyzer and machine vision. The texture values were determined using the 3-point bend test using breaking force gradient (BFG), peak breaking force (PBF), and breaking distance (BD). The fracturing properties determined by the crisp fracture support rig using fracture force gradient (FFG), peak fracture force (PFF), and fracture distance (FD). The machine vision evaluated the total surface area, lightness (L), color difference (ΔE), Hue (°h), and Chroma (C*). The results were evaluated by analysis of variance and means were separated using Tukey's test. Machine vision values of L, °h, were higher (P < 0.05) and ΔE was lower (P < 0.05) for fried and L, °h were significantly (P < 0.05) higher for baked chips produced from ultra-sonication as compare to traditional. Baked chips texture for ultra-sonication was significantly higher (P < 0.05) on BFG, BPD, PFF, and FD. Fried tortilla chips texture were higher significantly (P < 0.05) in BFG and PFF for ultra-sonication than traditional processing. However, the instrumental differences were not detected in sensory analysis, concluding possibility of power ultrasound as potential tortilla chips processing aid. © 2015 Institute of Food Technologists®

  1. Diode Pumped Alkali Vapor Lasers - A New Pathway to High Beam Quality at High Average Power

    SciTech Connect

    Page, R H; Boley, C D; Rubenchik, A M; Beach, R J

    2005-05-06

    Resonance-transition alkali-vapor lasers have only recently been demonstrated [1] but are already attracting considerable attention. Alkali-atom-vapor gain media are among the simplest possible systems known, so there is much laboratory data upon which to base performance predictions. Therefore, accurate modeling is possible, as shown by the zero- free-parameter fits [2] to experimental data on alkali-vapor lasers pumped with Ti:sapphire lasers. The practical advantages of two of the alkali systems--Rb and Cs--are enormous, since they are amenable to diode-pumping [3,4]. Even without circulating the gas mixture, these lasers can have adequate cooling built-in owing to the presence of He in their vapor cells. The high predicted (up to 70%) optical-to-optical efficiency of the alkali laser, the superb (potentially 70% or better) wall-plug efficiency of the diode pumps, and the ability to exhaust heat at high temperature (100 C) combine to give a power-scalable architecture that is lightweight. A recent design exercise [5] at LLNL estimated that the system ''weight-to-power ratio'' figure of merit could be on the order of 7 kg/kW, an unprecedented value for a laser of the 100 kW class. Beam quality is expected to be excellent, owing to the small dn/dT value of the gain medium. There is obviously a long way to go, to get from a small laser pumped with a Ti:sapphire or injection-seeded diode system (of near-perfect beam quality, and narrow linewidth) [1, 4] to a large system pumped with broadband, multimode diode- laser arrays. We have a vision for this technology-development program, and have already built diode-array-pumped Rb lasers at the 1 Watt level. A setup for demonstrating Diode-array-Pumped Alkali vapor Lasers (DPALs) is shown in Figure 1. In general, use of a highly-multimode, broadband pump source renders diode-array-based experiments much more difficult than the previous ones done with Ti:sapphire pumping. High-NA optics, short focal distances, and short

  2. Sleep, Sleep Disturbance and Fertility in Women

    PubMed Central

    Kloss, Jacqueline D.; Perlis, Michael; Zamzow, Jessica; Culnan, Elizabeth; Gracia, Clarisa

    2014-01-01

    Summary Sleep and sleep disturbances are increasingly recognized as determinants of women’s health and well-being, particularly in the context of the menstrual cycle, pregnancy, and menopause. At present, however, little is known about whether fertility is affected by sleep quantity and quality. That is, to what degree, and by what mechanisms, do sleep and/or its disturbances affect fertility? The purpose of this review is to synthesize what is known about sleep disturbances in relation to reproductive capacity. A model is provided, whereby stress, sleep dysregulation, and circadian misalignment are delineated for their potential relevance to infertility. Ultimately, if it is the case that sleep disturbance is associated with infertility, new avenues for clinical intervention may be possible. PMID:25458772

  3. Sleep Disturbances Associated with Parkinson's Disease

    PubMed Central

    Suzuki, Keisuke; Miyamoto, Masayuki; Miyamoto, Tomoyuki; Iwanami, Masaoki; Hirata, Koichi

    2011-01-01

    Sleep disturbances are common problems affecting the quality life of Parkinson's disease (PD) patients and are often underestimated. The causes of sleep disturbances are multifactorial and include nocturnal motor disturbances, nocturia, depressive symptoms, and medication use. Comorbidity of PD with sleep apnea syndrome, restless legs syndrome, rapid eye movement sleep behavior disorder, or circadian cycle disruption also results in impaired sleep. In addition, the involvement of serotoninergic, noradrenergic, and cholinergic neurons in the brainstem as a disease-related change contributes to impaired sleep structures. Excessive daytime sleepiness is not only secondary to nocturnal disturbances or dopaminergic medication but may also be due to independent mechanisms related to impairments in ascending arousal system and the orexin system. Notably, several recent lines of evidence suggest a strong link between rapid eye movement sleep behavior disorder and the risk of neurodegenerative diseases such as PD. In the present paper, we review the current literature concerning sleep disorders in PD. PMID:21876839

  4. Effect of power distribution on the weld quality during hybrid laser welding of an Al-Mg alloy

    NASA Astrophysics Data System (ADS)

    Leo, P.; Renna, G.; Casalino, G.; Olabi, A. G.

    2015-10-01

    This paper treats of the analysis of the effect of arc and laser powers on the quality of the arc assisted fiber laser welding of an Al-Mg alloy in the butt configuration. Grain size, weld geometry defects, porosity, and magnesium loss were measured. Magnesium content of the fused zone decreased as the laser power increased while the porosity increased with laser power. Microhardness profiles and tensile properties were explained on the basis of the joint microstructure and defects and related to the power distribution. The porosity level and Mg content in the fused zone affected both tensile strength and ductility. The power distribution that stabilized the welding process and minimize the weld porosity was defined.

  5. Disturbance Dynamics in Transitional and Turbulent Flows

    NASA Technical Reports Server (NTRS)

    Grosch, Chester E.

    1999-01-01

    In order to expand the predictive capability of single-point turbulence closure models to account for the early-stage transition regime, a methodology for the formulation and calibration of model equations for the ensemble-averaged disturbance kinetic energy and energy dissipation rate is presented. First the decay of laminar disturbances and turbulence in mean shear-free flows is studied. In laminar flows, such disturbances are linear superpositions of modes governed by the Orr-Sommerfeld equation. In turbulent flows, disturbances are described through transport equations for representative mean quantities. The link between a description based on a deterministic evolution equation and a probability based mean transport equation is established. Because an uncertainty in initial conditions exists in the laminar as well as the turbulent regime, a probability distribution must be defined even in the laminar case. Using this probability distribution, it is shown that the exponential decay of the linear modes in the laminar regime can be related to a power law decay of both the (ensemble) mean disturbance kinetic energy and the dissipation rate. The evolution of these mean disturbance quantities is then described by transport equations similar to those for the corresponding turbulent decaying flow. Second, homogeneous shear flow, where disturbances can be described by rapid distortion theory (RDT), is studied. The relationship between RDT and linear stability theory is exploited in order to obtain a closed set of modeled equations. The linear disturbance equations are solved directly so that the numerical simulation yields a database from which the closure coefficients in the ensemble-averaged disturbance equations can be determined.

  6. Disturbance observer based pitch control of wind turbines for disturbance rejection

    NASA Astrophysics Data System (ADS)

    Yuan, Yuan; Chen, Xu; Tang, Jiong

    2016-04-01

    In this research, a disturbance observer based (DOB) control scheme is illustrated to reject the unknown low frequency disturbances to wind turbines. Specifically, we aim at maintaining the constant output power but achieving better generator speed regulation when the wind turbine is operated at time-varying and turbulent wind field. The disturbance observer combined with a filter is designed to asymptotically reject the persistent unknown time-varying disturbances. The proposed algorithm is tested in both linearized and nonlinear NREL offshore 5-MW baseline wind turbine. The application of this DOB pitch controller achieves improved power and speed regulation in Region 3 compared with a baseline gain scheduling PID collective controller both in linearized and nonlinear plant.

  7. [Impacts of Ochotona pallasi disturbance on alpine grassland community characteristics].

    PubMed

    Zhao, Guo-qin; Li, Guang-yong; Ma, Wen-hu; Zhao, Dian-zhi; Li, Xiao-yan

    2013-08-01

    Plateau pika is the main fossorial mammal in the alpine grassland in Qinghai Lake Watershed of Northwest China. Based on the field investigation data from 18 alpine grassland quadrats in the Watershed, and by using redundancy analysis (RDA) and the surface fitting offered by 'R-Vegan' , the disturbance intensity of plateau pika (Ochotona pallasi) was classified as four levels. In order to explore the impacts of plateau pika disturbance on the alpine grassland ecosystem and its grazing quality, the community characteristics under different disturbance intensities by plateau pika were analyzed, and a conceptual model about the alpine grassland community succession was proposed. The results showed that with the increase of the disturbance intensity, the dominant species changed from Juncus roemerianus to Poa pratensis and Laux maritima. When the disturbance was small, the community had high quantitative values of coverage, aboveground biomass, biodiversity, and species richness, but the proportion of weeds was also high. When the disturbance was large, the quantitative values were the lowest, while the proportion of weeds was the highest. When the disturbance was moderate, the community had relatively high quantitative values, and the proportion of grasses and sedges was the highest. It was concluded that the community' s characteristic values under low plateau pika disturbance intensity were high but the grazing quality was low, while high disturbance intensity resulted in the grassland degradation. Therefore, the disturbance intensity in the threshold could maintain the stability of alpine grassland ecosystem and improve its grazing quality.

  8. Hydrological disturbance diminishes predator control in wetlands.

    PubMed

    Dorn, Nathan J; Cook, Mark I

    2015-11-01

    Effects of predators on prey populations can be especially strong in aquatic ecosystems, but disturbances may mediate the strength of predator limitation and even allow outbreaks of some prey populations. In a two-year study we investigated the numerical responses of crayfish (Procambarus fallax) and small fishes (Poeciliidae and Fundulidae) to a brief hydrological disturbance in replicated freshwater wetlands with an experimental drying and large predatory fish reduction. The experiment and an in situ predation assay tested the component of the consumer stress model positing that disturbances release prey from predator limitation. In the disturbed wetlands, abundances of large predatory fish were seasonally reduced, similar to dynamics in the Everglades (southern Florida). Densities of small fish were unaffected by the disturbance, but crayfish densities, which were similar across all wetlands before drying, increased almost threefold in the year after the disturbance. Upon re-flooding, juvenile crayfish survival was inversely related to the abundance of large fish across wetlands, but we found no evidence for enhanced algal food quality. At a larger landscape scale (500 km2 of the Everglades), crayfish densities over eight years were positively correlated with the severity of local dry disturbances (up to 99 days dry) during the preceding dry season. In contrast, densities of small-bodied fishes in the same wetlands were seasonally depressed by dry disturbances. The results from our experimental wetland drought and the observations of crayfish densities in the Everglades represent a large-scale example of prey population release following a hydrological disturbance in a freshwater ecosystem. The conditions producing crayfish pulses in the Everglades appear consistent with the mechanics of the consumer stress model, and we suggest crayfish pulses may influence the number of nesting wading birds in the Everglades.

  9. Age associated declines in muscle mass, strength, power, and physical performance: impact on fear of falling and quality of life

    USDA-ARS?s Scientific Manuscript database

    SUMMARY: This 3 year longitudinal study among older adults showed that declining muscle mass, strength, power, and physical performance are independent contributing factors to increased fear of falling, while declines of muscle mass and physical performance contribute to deterioration of quality of ...

  10. Power analysis and trend detection for water quality monitoring data. An application for the Greater Yellowstone Inventory and Monitoring Network

    USGS Publications Warehouse

    Irvine, Kathryn M.; Manlove, Kezia; Hollimon, Cynthia

    2012-01-01

    An important consideration for long term monitoring programs is determining the required sampling effort to detect trends in specific ecological indicators of interest. To enhance the Greater Yellowstone Inventory and Monitoring Network’s water resources protocol(s) (O’Ney 2006 and O’Ney et al. 2009 [under review]), we developed a set of tools to: (1) determine the statistical power for detecting trends of varying magnitude in a specified water quality parameter over different lengths of sampling (years) and different within-year collection frequencies (monthly or seasonal sampling) at particular locations using historical data, and (2) perform periodic trend analyses for water quality parameters while addressing seasonality and flow weighting. A power analysis for trend detection is a statistical procedure used to estimate the probability of rejecting the hypothesis of no trend when in fact there is a trend, within a specific modeling framework. In this report, we base our power estimates on using the seasonal Kendall test (Helsel and Hirsch 2002) for detecting trend in water quality parameters measured at fixed locations over multiple years. We also present procedures (R-scripts) for conducting a periodic trend analysis using the seasonal Kendall test with and without flow adjustment. This report provides the R-scripts developed for power and trend analysis, tutorials, and the associated tables and graphs. The purpose of this report is to provide practical information for monitoring network staff on how to use these statistical tools for water quality monitoring data sets.

  11. CALiPER Retail Lamps Study 3.1: Dimming, Flicker, and Power Quality Characteristics of LED A Lamps

    SciTech Connect

    none,

    2014-12-31

    This CALiPER report examines the characteristics of a subset of lamps from CALiPER Retail Lamps Study 3 in more detail. Specifically, it focuses on the dimming, power quality, and flicker characteristics of 14 LED A lamps, as controlled by four different retail-available dimmers.

  12. Measurement of mechanical quality factors of polymers in flexural vibration for high-power ultrasonic application.

    PubMed

    Wu, Jiang; Mizuno, Yosuke; Tabaru, Marie; Nakamura, Kentaro

    2016-07-01

    A method for measuring the mechanical quality factor (Q factor) of materials in large-amplitude flexural vibrations was devised on the basis of the original definition of the Q factor. The Q factor, the ratio of the reactive energy to the dissipated energy, was calculated from the vibration velocity distribution. The bar thickness was selected considering the effect of the thickness on the estimation error. In the experimental setup, a 1-mm-thick polymer-based bar was used as a sample and fixed on the top of a longitudinal transducer. Using transducers of different lengths, flexural waves in the frequency range of 20-90kHz were generated on the bar. The vibration strain in the experiment reached 0.06%. According to the Bernoulli-Euler model, the reactive energy and dissipated energy were estimated from the vertical velocity distribution on the bar, and the Q factors were measured as the driving frequency and strain were varied. The experimental results showed that the Q factors decrease as the driving frequencies and strains increase. At a frequency of 28.30kHz, the Q factor of poly(phenylene sulfide) (PPS) reached approximately 460 when the strain was smaller than 0.005%. PPS exhibited a much higher Q factor than the other tested polymers, which implies that it is a potentially applicable material as the elastomer for high-power ultrasonic devices.

  13. Intercomparison of methods for image quality characterization. II. Noise power spectrum

    SciTech Connect

    Dobbins, James T. III; Samei, Ehsan; Ranger, Nicole T.; Chen Ying

    2006-05-15

    Second in a two-part series comparing measurement techniques for the assessment of basic image quality metrics in digital radiography, in this paper we focus on the measurement of the image noise power spectrum (NPS). Three methods were considered: (1) a method published by Dobbins et al. [Med. Phys. 22, 1581-1593 (1995)] (2) a method published by Samei et al. [Med. Phys. 30, 608-622 (2003)], and (3) a new method sanctioned by the International Electrotechnical Commission (IEC 62220-1, 2003), developed as part of an international standard for the measurement of detective quantum efficiency. In addition to an overall comparison of the estimated NPS between the three techniques, the following factors were also evaluated for their effect on the measured NPS: horizontal versus vertical directional dependence, the use of beam-limiting apertures, beam spectrum, and computational methods of NPS analysis, including the region-of-interest (ROI) size and the method of ROI normalization. Of these factors, none was found to demonstrate a substantial impact on the amplitude of the NPS estimates ({<=}3.1% relative difference in NPS averaged over frequency, for each factor considered separately). Overall, the three methods agreed to within 1.6%{+-}0.8% when averaged over frequencies >0.15 mm{sup -1}.

  14. [The self healing power of cities--civil qualities of urban life].

    PubMed

    Akbar, O

    2005-12-01

    Health and hygiene are top issues from the early days down the history of a town or a city. Pestilence, epidemic plagues and infectious diseases are once in a while endangering the delicate equilibrium of a city as an organism. Many infra-structural measures are taken to ensure health in and of the city. What makes a healthy city is not just the absence of illness, a healthy city is inspired by the mentality of their citizens, it is a work of art and based on an consensus of what does mean quality of live for the city and its inhabitants. It is multifaceted and can develop the power to regenerate itself. In times of a demographic change with more elderly people in the future then ever and less money in public pursues we nevertheless have the civic duties and the obligation to look after health of our cities. Many faculties like science, visual art, engineering and design must cooperate and work together toward that goal.

  15. Solar Development on Contaminated and Disturbed Lands

    SciTech Connect

    Macknick, Jordan; Lee, Courtney; Mosey, Gail; Melius, Jenny

    2013-12-01

    Land classified as contaminated and disturbed across the United States has the potential to host developments of utility-scale solar power. This report examines the prospect of developing utility- and commercial-scale concentrated solar power (CSP) and solar photovoltaics (PV) technologies on degraded and environmentally contaminated lands. The potential for solar development on contaminated anddisturbed lands was assessed, and for the largest and highest solar resource sites, the economic impacts and feasibility were evaluated. Developing solar power on contaminated and disturbed lands can help create jobs and revitalize local and state economies, and selecting these sites over greenfield sites can potentially have permitting and environmental mitigation advantages. The U.S.Department of Energy (DOE) SunShot goals call for 632 GW of PV and 83 GW of CSP to be deployed by 2050. Conservative land-use estimates of this study (10 acres per megawatt) show that there are disturbed and environmentally contaminated lands throughout the country that could be suitable for utility-scale solar power, and, that there is sufficient land area to meet SunShot solar deployment goals. The purpose of this assessment is to improve the understanding of these sites and facilitate solar developers' selection of contaminated and disturbed sites for development.

  16. Large deflection angle, high-power adaptive fiber optics collimator with preserved near-diffraction-limited beam quality.

    PubMed

    Zhi, Dong; Ma, Yanxing; Chen, Zilun; Wang, Xiaolin; Zhou, Pu; Si, Lei

    2016-05-15

    We report on the development of a monolithic adaptive fiber optics collimator, with a large deflection angle and preserved near-diffraction-limited beam quality, that has been tested at a maximal output power at the 300 W level. Additionally, a new measurement method of beam quality (M2 factor) is developed. Experimental results show that the deflection angle of the collimated beam is in the range of 0-0.27 mrad in the X direction and 0-0.19 mrad in the Y direction. The effective working frequency of the device is about 710 Hz. By employing the new measurement method of the M2 factor, we calculate that the beam quality is Mx2=1.35 and My2=1.24, which is in agreement with the result from the beam propagation analyzer and is preserved well with the increasing output power.

  17. 1992 system disturbances

    SciTech Connect

    Not Available

    1993-10-01

    When a utility experiences an electric system emergency that requires reporting to the DOE, the utility sends a copy of the report to its Regional Council, which then sends a copy to NERC. Canadian utilities often voluntarily file emergency reports to DOE and NERC as well. NERC's annual review of system disturbances begins in November when the Disturbance Analysis Working Group meets to discuss each disturbance reported to NERC so far that year. The Group then contacts the Regional Council or utility(ies) involved and requests a detailed report of each incident. The Group then summarizes the report for this Review and analyzes it using the NERC Operating Guides and Planning Policies and Guides as the analysis categories. The Commentary section includes the conclusions and recommendations that were formulated from the analyses in this report plus the general experiences of the Working Group through the years. In 1992, utilities reported 22 incidents of system disturbances, load reductions, or unusual occurrences. This is eight fewer than reported in 1991. These incidents are listed chronologically and categorized as: fourteen system interruptions that resulted in loss of customer service, eight unusual occurrences that did not cause a service interruption. No public appeals to reduce demand or voltage reductions occurred in 1992. This document contains reports of 11 incidents plus a summary of the damage from Hurricane Andrew. Each utility or Region approved its analysis in this report. Included is a table of Disturbances by Analysis Category that offers a quick review of the categories applicable to each incident.

  18. Numerical analysis on the beam quality improvements of high power chemical laser system with water cooled mirrors

    NASA Astrophysics Data System (ADS)

    Han, Kai; Li, Bin; Xu, Xiao-jun

    2011-06-01

    Chemical laser is one of the most widely used high power infrared sources. Thermal deformation of mirrors in a resonator is a key factor which hinders the improvement of the beam quality in high power chemical lasers, and it has been a matter of the utmost concern in the design of high power chemical laser systems. Water-cooled technique is one of the most widely methods employed in cooling mirrors in high power laser systems. Several kinds of water-cooled mirrors have been studied by researchers in the world. Research teams of the United States and Russia have done a lot of work and their water cooled mirrors behave very well. In China, the study of micro-channel water cooled silicon mirror has been carried out by Cheng Zuhai in detail and the research of water jet cooled mirror has been performed by Li Bin. Both the two types of water cooled mirrors show excellent capabilities in alleviating the thermal deformation of mirrors. However, the issues that how and to what extent the beam quality is improved when the water cooled mirrors are involved have not been analyzed so far. In this paper, through numerical simulations, the beam qualities of linear resonators with various types of water cooled mirrors are analyzed in detail, and the effects of the two types of water cooled mirrors are compared. The thermal distortion of uncooled Si mirrors is characterized by Zernike polynomials and the beam quality is characterized with Strehl ratio, β factor, and M2 factor, which degenerates as the beam oscillates in the distorted resonator. The aberrance of mirrors non-uniformly heated by high energy laser mainly distributes on the low-even-order Zernike polynomials. When the uncooled Si mirrors are replaced by water cooled mirrors, the distortion decreases greatly and the beam quality is improved a lot. Although the performance of the water jet cooled mirror on mitigating distortion is better than the micro-channel water cooled mirror, the resonator made up of two water jet

  19. Impact of late effects on health-related quality of life in survivors of pediatric brain tumors: motility disturbance of limb(s), seizure, ocular/visual impairment, endocrine abnormality, and higher brain dysfunction.

    PubMed

    Sato, Iori; Higuchi, Akiko; Yanagisawa, Takaaki; Murayama, Shiho; Kumabe, Toshihiro; Sugiyama, Kazuhiko; Mukasa, Akitake; Saito, Nobuhito; Sawamura, Yutaka; Terasaki, Mizuhiko; Shibui, Soichiro; Takahashi, Jun; Nishikawa, Ryo; Ishida, Yasushi; Kamibeppu, Kiyoko

    2014-01-01

    Survivors of pediatric brain tumors are often affected by late effects, such as motility disturbance of limb(s), seizure, ocular/visual impairment, endocrine abnormality, and higher brain dysfunction, resulting from the disease and its treatment. Appropriate provision of supportive care will require understanding the effects of these experiences on survivors' health-related quality of life (HRQOL). The aim of this study was to identify the relationships between late effects and specific aspects of the HRQOL of pediatric brain tumor survivors. We distributed questionnaires for measuring HRQOL to 138 survivors and their parents at 8 hospitals and 1 clinic in Japan and simultaneously surveyed late effects using information provided by the survivors' attending physicians. We compared the HRQOL of survivors with and survivors without specific late effects. A total of 106 survivors and their parents returned the questionnaires to the researchers. The HRQOL of survivors 18 years or older was negatively affected by all 5 late effects, indicating that their higher impairment was associated with diminished HRQOL. The HRQOL of survivors aged 12 to 17 years was negatively affected by 2 late effects (ocular/visual impairment and motility disturbance of the limbs). A part of the HRQOL subdomain (motor and cognitive functioning) of survivors aged 12 to 17 years was positively related to ocular/visual impairment. Five late effects influenced the HRQOL of pediatric brain tumor survivors. Nurses and other health professionals should provide specific care designed to support aspects of HRQOL affected by late effects. For example, survivors with ocular/visual impairment may be expected to require additional emotional support, and those with seizures or endocrine abnormalities may be expected to require additional support for sleep disorders.

  20. Mapping surface disturbance from wind farms

    NASA Astrophysics Data System (ADS)

    Diffendorfer, James E.

    2013-04-01

    Wind energy is one of the fastest growing segments of the electricity market and this trend will likely continue as countries strive to reduce CO2 production while meeting growing energy demands. One impact of wind facilities is surface disturbance, including roads, that lead to habitat loss and fragmentation. Numerous studies of wind power utilize estimates of surface disturbance for GIS-based modeling or basic calculations of the land area required to generate energy using wind. However published estimates of the land use required for a MW of electricity from wind facilities vary by more than 10 times (0.83 to 250 MW/Km2). We report results from a geospatial analysis of 39 wind facilities in the United States that we fully digitized using high resolution photo-imagery. The selected sites and analyses were designed to elucidate the effects of turbine size, topography, and land use on the area requirements of wind facilities. The results indicate point estimates of average surface disturbance/MW have wide levels of variation, explained primarily by Landcover and Topography. Wind facilities in agricultural landscapes had smaller surface disturbance/ha than facilities in forests and shrublands, and facilities in relatively flat topography had smaller surface disturbance/ha than facilities on hills, ridges, or mesas. Land use, topography, and turbine size all influenced turbine spacing. The statistical models suggest we can predict geographic locations where new wind facilities could be placed with minimized surface disturbance.

  1. Forest development leading to disturbances

    Treesearch

    Clinton E. Carlson; Stephen F. Arno; Jimmie Chew; Catherine A. Stewart

    1995-01-01

    Natural disturbance in western U.S.A. forest ecosystems is related to forest succession, growth, and structural development. Natural disturbance may be biotic (insects and diseases) or abiotic (fire, wind, avalanche, etc.). Natural disturbances are more appropriately thought of as natural processes; disturbance is a social connotation implicating economic loss. Forest...

  2. Retail Lamps Study 3.1: Dimming, Flicker, and Power Quality Characteristics of LED A Lamps

    SciTech Connect

    Royer, Michael P.; Poplawski, Michael E.; Brown, Charles C.

    2014-12-01

    To date, all three reports in the retail lamps series have focused on basic performance parameters, such as lumen output, efficacy, and color quality. This report goes a step further, examining the photoelectric characteristics (i.e., dimming and flicker) of a subset of lamps from CALiPER Retails Lamps Study 3. Specifically, this report focuses on the dimming, power quality, and flicker characteristics of 14 LED A lamps, as controlled by four different retail-available dimmers. The results demonstrate notable variation across the various lamps, but little variation between the four dimmers. Overall, the LED lamps: ~tended to have higher relative light output compared to the incandescent and halogen benchmark at the same dimmer output signal (RMS voltage). The lamps’ dimming curves (i.e., the relationship between control signal and relative light output) ranged from linear to very similar to the square-law curve typical of an incandescent lamp. ~generally exhibited symmetrical behavior—the same dimming curve—when measured proceeding from maximum to minimum or minimum to maximum control signal. ~mostly dimmed below 10% of full light output, with some exceptions for specific lamp and dimmer combinations ~exhibited a range of flicker characteristics, with many comparing favorably to the level typical of a magnetically-ballasted fluorescent lamp through at least a majority of the dimming range. ~ always exceeded the relative (normalized) efficacy over the dimming range of the benchmark lamps, which rapidly decline in efficacy when they are dimmed. This report generally does not attempt to rank the performance of one product compared to another, but instead focuses on the collective performance of the group versus conventional incandescent or halogen lamps, the performance of which is likely to be the baseline for a majority of consumers. Undoubtedly, some LED lamps perform better—or more similar to conventional lamps—than others. Some perform desirably for one

  3. High Quality Power Supply Method for Islanding Microgrid by use of Several Types of DG Systems including Rotating Machines

    NASA Astrophysics Data System (ADS)

    Kikuchi, Takuro; Baba, Jumpei; Kawachi, Shunsuke; Shimoda, Eisuke; Numata, Shigeo; Yamane, Toshihiro; Masada, Eisuke; Nitta, Tanzo

    When a microgrid is operated in the islanding mode, the operator must satisfy the power quality demand by compensating the active and reactive power using several types of distributed power generation (DG) systems. In this paper, a method to stabilize the system frequency fluctuations and voltage fluctuations of the islanding microgrid is suggested. Extending the suggested “combined cascade control method” which can realize the power compensation without interferences between several types of DGs, “hybrid control” strucuture is proposed and negative effects of control and measurement signal delays on a control are reduced. Moreover, a control of the state of charge (SoC) of energy storage devices is added. For the stabilization of the system voltage, the energy storage is driven by “STATCOM model control”. Experiments have been carried out to confirm the effects of these methods by use of the model microgrid system, and satisfying results were received.

  4. Coherent beam combining of high power broad-area laser diode array with near diffraction limited beam quality and high power conversion efficiency.

    PubMed

    Liu, B; Braiman, Y

    2013-12-16

    We explored a path of achieving high quality phase-locking of broad-area laser diode (BALD) array that operates at high electrical to optical power conversion efficiency (PCE). We found that (a) improving single transverse mode control for each individual BALD, (b) employing global Talbot optical coupling among diodes, and (c) enhancing strength of optical coupling among diodes are key factors in achieving high quality phase-locking of high power BALD array. Subsequently, we redesigned and improved a V-shaped external Talbot cavity and employed low reflectivity anti-reflection (AR) coated, low-"smile" BALD array to meet these three important requirements. We demonstrated near-diffraction limit far-field coherent pattern with 19% PCE and 95% visibility. The far-field angle (full-width at half-maximum (FWHM)) of center lobe was measured as 1.5 diffraction angular limited with visibility of 99% for 5A injection current and 1.6 diffraction angular limited with visibility of 95% for 14A injection current. Power scaling of diode array is discussed.

  5. Effects of performance-based reimbursement on the professional autonomy and power of physicians and the quality of care.

    PubMed

    Forsberg, E; Axelsson, R; Arnetz, B

    2001-01-01

    The key question addressed in this study is whether performance-based reimbursement in health care affects the professional power and autonomy of physicians, and if so, whether this has any consequences for the quality of care. This cohort study examines the period 1994-98 in 11 Swedish county councils. Four hundred and eighteen physicians were studied in Stockholm County Council, which has a performance-based reimbursement system, and in ten councils without such a system. The results show that professional power and autonomy are considered to be very limited in all councils, and that they have decreased during the period studied. Professional autonomy is, however, more limited in Stockholm. The limitations in Stockholm are more related to financial considerations, whereas the limitations in the other councils are more due to guidelines and lists of recommended drugs. Professional autonomy and power were found to be important determinants for quality of care, and the physicians in Stockholm estimated the quality of care lower than their colleagues in the ten other councils. Thus, our study suggests that the performance-based reimbursement system might fail to reach the desired results due to its negative impact on professional power and autonomy.

  6. Pulse doubling in zigzag-connected autotransformer-based 12-pulse ac-dc converter for power quality improvement

    NASA Astrophysics Data System (ADS)

    Abdollahi, Rohollah

    2012-12-01

    This paper presents a pulse doubling technique in a 12-pulse ac-dc converter which supplies direct torque controlled motor drives (DTCIMDs) in order to have better power quality conditions at the point of common coupling. The proposed technique increases the number of rectification pulses without significant changes in the installations and yields in harmonic reduction in both ac and dc sides. The 12-pulse rectified output voltage is accomplished via two paralleled six-pulse acdc converters each of them consisting of three-phase diode bridge rectifiers. An autotransformer is designed to supply the rectifiers. The design procedure of magnetics is in a way such that makes it suitable for retrofit applications where a six-pulse diode bridge rectifier is being utilized. Independent operation of paralleled diode-bridge rectifiers, i.e. dc-ripple re-injection methodology, requires a Zero Sequence Blocking Transformer (ZSBT). Finally, a tapped interphase reactor is connected at the output of ZSBT to double the pulse numbers of output voltage up to 24 pulses. The aforementioned structure improves power quality criteria at ac mains and makes them consistent with the IEEE-519 standard requirements for varying loads. Furthermore, near unity power factor is obtained for a wide range of DTCIMD operation. A comparison is made between 6-pulse, 12-pulse, and proposed converters from view point of power quality indices. Results show that input current total harmonic distortion (THD) is less than 5% for the proposed topology at various loads.

  7. Impacts of Photovoltaic Power Plant Sitings and Distributed Solar Panels on Meteorology and Air Quality in Central California

    NASA Astrophysics Data System (ADS)

    Bastien, L. A.; Jin, L.; Brown, N. J.

    2012-12-01

    California's electric utility companies are required to use renewable energy to produce 20% of their power by 2010 and 33% by 2020. A main source of the power will be solar energy because photovoltaic technologies have advanced so much that large scale installations are being built and will be built in the future with even greater capacity. Rather than being a large emission source, these plants affect the ambient environment through albedo changes and by emission reductions associated with not burning fossil fuels to generate the same amount of electricity. Like conventional power plants, their impact on local meteorology and air quality depends on the specific technology, ambient atmospheric conditions, and the spatial location of the plant. Also, as solar panels on commercial and residential rooftops become even more common, the effect of distributed photovoltaic panels on meteorology and air quality is likely to become significant. In this study, we use the Weather Research and Forecasting (WRF) model and the Community Multiscale Air Quality (CMAQ) model at high resolution of 4 km x 4 km over several 5-day high-ozone episodes of the summer 2000 to assess the impact of photovoltaic panels on meteorology and air quality in Central California. We investigate the effect of locating a 1.0 Giga watt solar plant in different locations and the effect of distributed rooftop photovoltaic panels in major Californian cities, with a focus on peak and 8-hour average ozone and 24-hour average PM2.5.

  8. Economics of Soil Disturbance

    Treesearch

    Han-Sup Han

    2007-01-01

    Economic implications of soil disturbance are discussed in four categories: planning and layout, selection of harvesting systems and equipment, long-term site productivity loss, and rehabilitation treatments. Preventive measures are more effective in minimizing impacts on soils than rehabilitation treatments because of the remedial expenses, loss of productivity until...

  9. Phase-OFDR for distributed disturbance measurement

    NASA Astrophysics Data System (ADS)

    Liehr, Sascha; Krebber, Katerina

    2016-05-01

    We introduce the optical frequency domain reflectometry (OFDR) technique based on intensity modulation frequency sweep measurement for distributed disturbance measurement in optical fibres. By evaluating interferometric Rayleigh scattering changes along the fibre, strain and temperature changes are detected with 100 n(epsilon) sensitivity and 10 mK resolution. The vibration frequencies for low frequencies and up to the kHz-range can be obtained from power change evaluation in the spatial domain. This novel OFDR approach is a low-cost alternative for distributed disturbance measurement up to distances of several kilometres.

  10. Microexternal cavity tapered lasers at 670 nm with 5 W peak power and nearly diffraction-limited beam quality.

    PubMed

    Tien, Tran Quoc; Maiwald, Martin; Sumpf, Bernd; Erbert, Götz; Tränkle, Günther

    2008-11-15

    Wavelength-stabilized compact laser systems at 670 nm on a micro-optical bench are presented. The resonator concept consists of a tapered semiconductor gain medium and a reflection Bragg grating as a wavelength selective resonator mirror. In pulse operation mode with 100 ns pulses, an optical peak power of 5 W with a spectral width below 150 pm was achieved. Nearly diffraction-limited beam quality at optical output powers up to 1 W is obtained. Such laser systems can be used, e.g., for Raman spectroscopy and as pumping sources for frequency conversion toward UV spectral range.

  11. The air quality and regional climate effects of widespread solar power generation under a changing regulatory environment

    NASA Astrophysics Data System (ADS)

    Millstein, D.; Zhai, P.; Menon, S.

    2011-12-01

    Over the past decade significant reductions of NOx and SOx emissions from coal burning power plants in the U.S. have been achieved due to regulatory action and substitution of new generation towards natural gas and wind power. Low natural gas prices, ever decreasing solar generation costs, and proposed regulatory changes, such as to the Cross State Air Pollution Rule, promise further long-run coal power plant emission reductions. Reduced power plant emissions have the potential to affect ozone and particulate air quality and influence regional climate through aerosol cloud interactions and visibility effects. Here we investigate, on a national scale, the effects on future (~2030) air quality and regional climate of power plant emission regulations in contrast to and combination with policies designed to aggressively promote solar electricity generation. A sophisticated, economic and engineering based, hourly power generation dispatch model is developed to explore the integration of significant solar generation resources (>10% on an energy basis) at various regions across the county, providing detailed estimates of substitution of solar generation for fossil fuel generation resources. Future air pollutant emissions from all sectors of the economy are scaled based on the U.S. Environmental Protection Agency's National Emission Inventory to account for activity changes based on population and economic projections derived from county level U.S. Census data and the Energy Information Administration's Annual Energy Outlook. Further adjustments are made for technological and regulatory changes applicable within various sectors, for example, emission intensity adjustments to on-road diesel trucking due to exhaust treatment and improved engine design. The future year 2030 is selected for the emissions scenarios to allow for the development of significant solar generation resources. A regional climate and air quality model (Weather Research and Forecasting, WRF model) is

  12. High power and good beam quality of two-dimensional VCSEL array with integrated GaAs microlens array.

    PubMed

    Wang, Zhenfu; Ning, Yongqiang; Zhang, Yan; Shi, Jingjing; Zhang, Xing; Zhang, Lisen; Wang, Wei; Liu, Di; Hu, Yongsheng; Cong, Haibing; Qin, Li; Liu, Yun; Wang, Lijun

    2010-11-08

    High power and good beam quality of two-dimensional bottom-emitting vertical-cavity surface-emitting laser array with GaAs microlens on the substrate is achieved. Uniform and matched convex microlens is directly fabricated by one-step diffusion-limited wet-etching techniques on the emitting windows. The maximum output power is above 1 W at continuous-wave operation at room temperature, and the far-field beam divergence is below 6.6° at a current of 4 A. These properties between microlens-integrated and conventional device at different operating current are demonstrated.

  13. Pulse homodyne field disturbance sensor

    DOEpatents

    McEwan, Thomas E.

    1997-01-01

    A field disturbance sensor operates with relatively low power, provides an adjustable operating range, is not hypersensitive at close range, allows co-location of multiple sensors, and is inexpensive to manufacture. The sensor includes a transmitter that transmits a sequence of transmitted bursts of electromagnetic energy. The transmitter frequency is modulated at an intermediate frequency. The sequence of bursts has a burst repetition rate, and each burst has a burst width and comprises a number of cycles at a transmitter frequency. The sensor includes a receiver which receives electromagnetic energy at the transmitter frequency, and includes a mixer which mixes a transmitted burst with reflections of the same transmitted burst to produce an intermediate frequency signal. Circuitry, responsive to the intermediate frequency signal indicates disturbances in the sensor field. Because the mixer mixes the transmitted burst with reflections of the transmitted burst, the burst width defines the sensor range. The burst repetition rate is randomly or pseudo-randomly modulated so that bursts in the sequence of bursts have a phase which varies. A second range-defining mode transmits two radio frequency bursts, where the time spacing between the bursts defines the maximum range divided by two.

  14. Pulse homodyne field disturbance sensor

    DOEpatents

    McEwan, T.E.

    1997-10-28

    A field disturbance sensor operates with relatively low power, provides an adjustable operating range, is not hypersensitive at close range, allows co-location of multiple sensors, and is inexpensive to manufacture. The sensor includes a transmitter that transmits a sequence of transmitted bursts of electromagnetic energy. The transmitter frequency is modulated at an intermediate frequency. The sequence of bursts has a burst repetition rate, and each burst has a burst width and comprises a number of cycles at a transmitter frequency. The sensor includes a receiver which receives electromagnetic energy at the transmitter frequency, and includes a mixer which mixes a transmitted burst with reflections of the same transmitted burst to produce an intermediate frequency signal. Circuitry, responsive to the intermediate frequency signal indicates disturbances in the sensor field. Because the mixer mixes the transmitted burst with reflections of the transmitted burst, the burst width defines the sensor range. The burst repetition rate is randomly or pseudo-randomly modulated so that bursts in the sequence of bursts have a phase which varies. A second range-defining mode transmits two radio frequency bursts, where the time spacing between the bursts defines the maximum range divided by two. 12 figs.

  15. Forest disturbances under climate change

    NASA Astrophysics Data System (ADS)

    Seidl, Rupert; Thom, Dominik; Kautz, Markus; Martin-Benito, Dario; Peltoniemi, Mikko; Vacchiano, Giorgio; Wild, Jan; Ascoli, Davide; Petr, Michal; Honkaniemi, Juha; Lexer, Manfred J.; Trotsiuk, Volodymyr; Mairota, Paola; Svoboda, Miroslav; Fabrika, Marek; Nagel, Thomas A.; Reyer, Christopher P. O.

    2017-06-01

    Forest disturbances are sensitive to climate. However, our understanding of disturbance dynamics in response to climatic changes remains incomplete, particularly regarding large-scale patterns, interaction effects and dampening feedbacks. Here we provide a global synthesis of climate change effects on important abiotic (fire, drought, wind, snow and ice) and biotic (insects and pathogens) disturbance agents. Warmer and drier conditions particularly facilitate fire, drought and insect disturbances, while warmer and wetter conditions increase disturbances from wind and pathogens. Widespread interactions between agents are likely to amplify disturbances, while indirect climate effects such as vegetation changes can dampen long-term disturbance sensitivities to climate. Future changes in disturbance are likely to be most pronounced in coniferous forests and the boreal biome. We conclude that both ecosystems and society should be prepared for an increasingly disturbed future of forests.

  16. Yb3+-doped rod-type amplifiers with local adiabatic tapers for peak power scaling and beam quality improvement

    NASA Astrophysics Data System (ADS)

    Zhu, Yuan; Eschrich, Tina; Leich, Martin; Grimm, Stephan; Kobelke, Jens; Lorenz, Martin; Bartelt, Hartmut; Jäger, Matthias

    2017-10-01

    The use of short local tapers in large mode area fiber amplifiers is proposed for peak power scaling while maintaining good beam quality. To avoid modal distortions, the powder-sintering (REPUSIL) method was employed to obtain core materials with excellent refractive index homogeneity. First experiments with Yb3+-doped rod-type amplifiers delivered 2 ns pulses with peak powers of 540 kW and energies of 1.4 mJ for the untapered rod and 230 kW for the tapered rod (limited by facet damage). The beam quality improved from an M 2 value of approximately 10 to 3.5. The investigation of the taper structure indicates room for further improvement.

  17. Conversion of Low Quality Waste Heat to Electric Power with Small-Scale Organic Rankine Cycle (ORC) Engine/Generator Technology

    DTIC Science & Technology

    2016-08-01

    EW-201251) Conversion of Low Quality Waste Heat to Electric Power with Small-Scale Organic Rankine Cycle (ORC) Engine/Generator Technology...To) 09/30/2016 9/1912012 to 9/30/2016 4. TITLE AND SUBTITLE 5a. CONTRACT NUMBER Conversion of Low Quality Waste Heat to Electric Power with...unlimited 13. SUPPLEMENTARY NOTES None 14. ABSTRACT An Organic Rankine Cycle generator (ORC) converts low-grade waste heat ( °C) into electric power

  18. Process optimization in high-average-power ultrashort pulse laser microfabrication: how laser process parameters influence efficiency, throughput and quality

    NASA Astrophysics Data System (ADS)

    Schille, Joerg; Schneider, Lutz; Loeschner, Udo

    2015-09-01

    In this paper, laser processing of technical grade stainless steel and copper using high-average-power ultrashort pulse lasers is studied in order to gain deeper insight into material removal for microfabrication. A high-pulse repetition frequency picosecond and femtosecond laser is used in conjunction with high-performance galvanometer scanners and an in-house developed two-axis polygon scanner system. By varying the processing parameters such as wavelength, pulse length, fluence and repetition rate, cavities of standardized geometry are fabricated and analyzed. From the depths of the cavities produced, the ablation rate and removal efficiency are estimated. In addition, the quality of the cavities is evaluated by means of scanning electron microscope micrographs or rather surface roughness measurements. From the results obtained, the influence of the machining parameters on material removal and machining quality is discussed. In addition, it is shown that both material removal rate and quality increase by using femtosecond compared to picosecond laser pulses. On stainless steel, a maximum throughput of 6.81 mm3/min is achieved with 32 W femtosecond laser powers; if using 187 W picosecond laser powers, the maximum is 15.04 mm3/min, respectively. On copper, the maximum throughputs are 6.1 mm3/min and 21.4 mm3/min, obtained with 32 W femtosecond and 187 W picosecond laser powers. The findings indicate that ultrashort pulses in the mid-fluence regime yield most efficient material removal. In conclusion, from the results of this analysis, a range of optimum processing parameters are derived feasible to enhance machining efficiency, throughput and quality in high-rate micromachining. The work carried out here clearly opens the way to significant industrial applications.

  19. Development methods of steam turbines 3D geometry optical control for effective heat power equipment quality improvement

    NASA Astrophysics Data System (ADS)

    Dvoynishnikov, Sergey

    2014-08-01

    A method for steam turbines 3D geometry optical control for effective heat power equipment quality improvement is proposed. It is shown that technical characteristics of the developed optical phase triangulation method for precision contactless geometry diagnostics of steam turbines meet modern requirements to 3D geometry measuring instruments and are perspective for further development. It is shown that used phase step method provides measurement error less than 0.024% of measurement range.

  20. 76 FR 45741 - Approval and Promulgation of Air Quality Implementation Plans; Pennsylvania; Diesel-Powered Motor...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-08-01

    ...EPA proposes to approve the State Implementation Plan (SIP) revision submitted by the Commonwealth of Pennsylvania for the purpose of incorporating the Commonwealth's Diesel-Powered Motor Vehicle Idling Act (Act 124 of 2008, or simply Act 124) into the Pennsylvania SIP. Act 124, passed by the Pennsylvania General Assembly and signed into state law by Governor Rendell in October 2008 (and effective at the state level in February 2009), reduces the allowable time that heavy-duty, commercial highway diesel vehicles of over 10,000 pounds gross vehicle weight can idle their main propulsion engines. The law restricts idling of these commercial diesel vehicles (mostly heavy trucks and buses) to a period of 5 minutes per continuous 60 minute period (with certain allowable exemptions and exclusions). Act 124 applies statewide in the Commonwealth, and is estimated by Pennsylvania to significantly reduce emissions of nitrogen oxides (NOX), volatile organic compounds (VOCs), and fine particulate matter (PM). While idle time emissions limits are not mandatory under the Clean Air Act (CAA), incorporation of Act 124 into the SIP does strengthen the SIP, makes the state law federally enforceable by EPA, and allows the Commonwealth to take credit for emissions benefits from the rule as part of future Pennsylvania SIP revisions to demonstrate compliance with CAA National Ambient Air Quality Standards (NAAQS). This action is being taken under the CAA. In the Final Rules section of this Federal Register, EPA is approving the Commonwealth's SIP submittal as a direct final rule without prior proposal because EPA views this as a noncontroversial submittal and anticipates no adverse comments. A detailed rationale for the approval is set forth in the direct final rule. If no adverse comments are received in response to this action, no further activity is contemplated. If EPA receives adverse comments, the direct final rule will be withdrawn and all public comments received will be

  1. 160 W high-power, high-efficiency, near-diffraction-limited beam quality all-fiber picosecond pulse laser

    NASA Astrophysics Data System (ADS)

    Sun, Chang; Ge, Tingwu; An, Na; Cao, Kang; Wang, Zhiyong

    2016-10-01

    We experimentally demonstrate a high-power, high-efficiency, near-diffraction-limited beam quality all-fiber picosecond pulse laser, which consists of a passively mode-locked seed laser and three-stage master power amplifiers. A repetition frequency multiplier and a high Yb-doped gain fiber with shorter length are utilized in the laser system to suppress the nonlinear effects and reduce the pulse broadening caused by dispersion. Moreover, the homemade light mode controllers based on a coiling and tapering fiber technique and the active fiber of the amplifier with a relatively small mode area are adopted to improve the beam quality. In addition, by experimentally adjusting the active fiber length, the optical conversion efficiency of the overall laser system can be optimized. Eventually, a 160 W high-power, high-efficiency, near-diffraction-limited picosecond pulse fiber laser is obtained, with the beam quality factor M2 at 1.12 and an optical conversion efficiency of the system of 75%.

  2. Development of software to improve AC power quality on large spacecraft

    NASA Technical Reports Server (NTRS)

    Kraft, L. Alan

    1991-01-01

    To insure the reliability of a 20 kHz, AC power system on spacecraft, it is essential to analyze its behavior under many adverse operating conditions. Some of these conditions include overloads, short circuits, switching surges, and harmonic distortions. Harmonic distortions can cause malfunctions in equipment that the power system is supplying, and during extreme distortions such as voltage resonance, it can cause equipment and insulation failures due to the extreme peak voltages. HARMFLO, a power flow computer program, which was capable of analyzing harmonic conditions on three phase, balanced, 60 Hz, AC power systems, was modified to analyze single phase, 20 kHz, AC power systems. Since almost all of the equipment used on spacecraft power systems is electrically different from equipment used on terrestrial power systems, it was also necessary to develop mathematical models for the equipment to be used on the spacecraft. The results are that (1) the harmonic power now has a model of a single phase, voltage controlled, full wave rectifier; and (2) HARMFLO was ported to the SUN workstation platform.

  3. Development of software to improve AC power quality on large spacecraft

    NASA Technical Reports Server (NTRS)

    Kraft, L. Alan

    1991-01-01

    To insure the reliability of a 20 kHz, alternating current (AC) power system on spacecraft, it is essential to analyze its behavior under many adverse operating conditions. Some of these conditions include overloads, short circuits, switching surges, and harmonic distortions. Harmonic distortions can become a serious problem. It can cause malfunctions in equipment that the power system is supplying, and, during distortions such as voltage resonance, it can cause equipment and insulation failures due to the extreme peak voltages. To address the harmonic distortion issue, work was begun under the 1990 NASA-ASEE Summer Faculty Fellowship Program. Software, originally developed by EPRI, called HARMFLO, a power flow program capable of analyzing harmonic conditions on three phase, balanced, 60 Hz AC power systems, was modified to analyze single phase, 20 kHz, AC power systems. Since almost all of the equipment used on spacecraft power systems is electrically different from equipment used on terrestrial power systems, it was also necessary to develop mathematical models for the equipment to be used on the spacecraft. The modelling was also started under the same fellowship work period. Details of the modifications and models completed during the 1990 NASA-ASEE Summer Faculty Fellowship Program can be found in a project report. As a continuation of the work to develop a complete package necessary for the full analysis of spacecraft AC power system behavior, deployment work has continued through NASA Grant NAG3-1254. This report details the work covered by the above mentioned grant.

  4. Multi-Fresnel lenses pumping approach for improving high-power Nd:YAG solar laser beam quality.

    PubMed

    Liang, Dawei; Almeida, Joana

    2013-07-20

    To significantly improve the present-day high-power solar laser beam quality, a three-stage multi-Fresnel lenses approach is proposed for side-pumping either a Nd:YAG single-crystal or a core-doped Sm(3+)Nd:YAG ceramic rod. Optimum pumping and laser beam parameters are found through ZEMAX and LASCAD numerical analysis. The proposed scheme offers a uniform absorption profile along the rod. 167 W laser power can be achieved, corresponding to 29.3 W/m(2) collection efficiency. High brightness figure of merit of 8.34 W is expected for the core-doped rod within a convex-concave resonator, which is 1300 times higher than that of the most-recent high-power solar laser.

  5. Waveguide disturbance detection method

    DOEpatents

    Korneev, Valeri A.; Nihei, Kurt T.; Myer, Larry R.

    2000-01-01

    A method for detection of a disturbance in a waveguide comprising transmitting a wavefield having symmetric and antisymmetric components from a horizontally and/or vertically polarized source and/or pressure source disposed symmetrically with respect to the longitudinal central axis of the waveguide at one end of the waveguide, recording the horizontal and/or vertical component or a pressure of the wavefield with a vertical array of receivers disposed at the opposite end of the waveguide, separating the wavenumber transform of the wavefield into the symmetric and antisymmetric components, integrating the symmetric and antisymmetric components over a broad frequency range, and comparing the magnitude of the symmetric components and the antisymmetric components to an expected magnitude for the symmetric components and the antisymmetric components for a waveguide of uniform thickness and properties thereby determining whether or not a disturbance is present inside the waveguide.

  6. Atmospheric Disturbance Environment Definition

    NASA Technical Reports Server (NTRS)

    Tank, William G.

    1994-01-01

    Traditionally, the application of atmospheric disturbance data to airplane design problems has been the domain of the structures engineer. The primary concern in this case is the design of structural components sufficient to handle transient loads induced by the most severe atmospheric "gusts" that might be encountered. The concern has resulted in a considerable body of high altitude gust acceleration data obtained with VGH recorders (airplane velocity, V, vertical acceleration, G, altitude, H) on high-flying airplanes like the U-2 (Ehernberger and Love, 1975). However, the propulsion system designer is less concerned with the accelerations of the airplane than he is with the airflow entering the system's inlet. When the airplane encounters atmospheric turbulence it responds with transient fluctuations in pitch, yaw, and roll angles. These transients, together with fluctuations in the free-stream temperature and pressure will disrupt the total pressure, temperature, Mach number and angularity of the inlet flow. For the mixed compression inlet, the result is a disturbed throat Mach number and/or shock position, and in extreme cases an inlet unstart can occur (cf. Section 2.1). Interest in the effects of inlet unstart on the vehicle dynamics of large, supersonic airplanes is not new. Results published by NASA in 1962 of wind tunnel studies of the problem were used in support of the United States Supersonic Transport program (SST) (White, at aI, 1963). Such studies continued into the late 1970's. However, in spite of such interest, there never was developed an atmospheric disturbance database for inlet unstart analysis to compare with that available for the structures load analysis. Missing were data for the free-stream temperature and pressure disturbances that also contribute to the unStart problem.

  7. The singing power ratio as an objective measure of singing voice quality in untrained talented and nontalented singers.

    PubMed

    Watts, Christopher; Barnes-Burroughs, Kathryn; Estis, Julie; Blanton, Debra

    2006-03-01

    A growing body of contemporary research has investigated differences between trained and untrained singing voices. However, few studies have separated untrained singers into those who do and do not express abilities related to singing talent, including accurate pitch control and production of a pleasant timbre (voice quality). This investigation studied measures of the singing power ratio (SPR), which is a quantitative measure of the resonant quality of the singing voice. SPR reflects the amplification or suppression in the vocal tract of the harmonics produced by the sound source. This measure was acquired from the voices of untrained talented and nontalented singers as a means to objectively investigate voice quality differences. Measures of SPR were acquired from vocal samples with fast Fourier transform (FFT) power spectra to analyze the amplitude level of the partials in the acoustic spectrum. Long-term average spectra (LTAS) were also analyzed. Results indicated significant differences in SPR between groups, which suggest that vocal tract resonance, and its effect on perceived vocal timbre or quality, may be an important variable related to the perception of singing talent. LTAS confirmed group differences in the tuning of vocal tract harmonics.

  8. Quality indicators for palliative care services: mixed-method study testing for face validity, feasibility, discriminative power and usefulness.

    PubMed

    Leemans, Kathleen; Deliens, Luc; Francke, Anneke L; Vander Stichele, Robert; Van den Block, Lieve; Cohen, Joachim

    2015-01-01

    In the absence of a standardized, comprehensive and valid set of quality indicators for palliative care, we developed one for palliative care services in Belgium. This study evaluates its face validity, feasibility, discriminative power and usefulness. We combined a quantitative analysis evaluating the answers with qualitative interviews with the contact persons of all participating services. The quality indicator set was implemented in nine palliative care services in Belgium involving a measurement procedure with questionnaires to the patients of the services, their professional caregivers, family carers and physicians. The response rate was 56% for patients, 97% for caregivers, 56% for family carers and 65% for physicians, indicating good feasibility of the measurement procedure. During the interviews, caregivers found the indicator scores valid and none was extremely skewed, confirming their discriminative power. Still, 20 of the 80 indicators showed problems of feasibility and 5 of usefulness. One was discarded and the others were improved by changing either the formulation of the indicator or the questions used. Most participants expressed a desire for a smaller but still comprehensive set. Based on the results, minor adjustments were made to individual indicators, to the measurement tools and to the procedure used; the quality indicators are now ready for further evaluation and use across palliative care services in Belgium. As soon as these indicators are being used systematically, it will be possible to demonstrate and compare quality at the national and international levels and to evaluate improvement initiatives. © The Author(s) 2014.

  9. Environmental consequences of a power plant shut-down: a three-dimensional water quality model of Dublin Bay.

    PubMed

    Bedri, Zeinab; Bruen, Michael; Dowley, Aodh; Masterson, Bartholomew

    2013-06-15

    A hydro-environmental model is used to investigate the effect of cessation of thermal discharges from a power plant on the bathing water quality of Dublin Bay. Before closing down, cooling water from the plant was mixed with sewage effluent prior to its discharge, creating a warmer, less-saline buoyant pollutant plume that adversely affects the water quality of Dublin Bay. The model, calibrated to data from the period prior to the power-plant shut-down (Scenario1), assessed the water quality following its shut-down under two scenarios; (i) Scenario2: continued abstraction of water to dilute sewage effluents before discharge, and (ii) Scnenario3: sewage effluents are discharged directly into the Estuary. Comparison between scenarios was based on distribution of Escherichia coli (E. coli), a main bathing quality indicator. Scenarios1 and 2, showed almost similar E. coli distribution patterns while Scenario3 displayed significantly higher E. coli concentrations due to the increased stratification caused by the lack of prior dilution.

  10. Global Scale Solar Disturbances

    NASA Astrophysics Data System (ADS)

    Title, A. M.; Schrijver, C. J.; DeRosa, M. L.

    2013-12-01

    The combination of the STEREO and SDO missions have allowed for the first time imagery of the entire Sun. This coupled with the high cadence, broad thermal coverage, and the large dynamic range of the Atmospheric Imaging Assembly on SDO has allowed discovery of impulsive solar disturbances that can significantly affect a hemisphere or more of the solar volume. Such events are often, but not always, associated with M and X class flares. GOES C and even B class flares are also associated with these large scale disturbances. Key to the recognition of the large scale disturbances was the creation of log difference movies. By taking the log of images before differencing events in the corona become much more evident. Because such events cover such a large portion of the solar volume their passage can effect the dynamics of the entire corona as it adjusts to and recovers from their passage. In some cases this may lead to a another flare or filament ejection, but in general direct causal evidence of 'sympathetic' behavior is lacking. However, evidence is accumulating these large scale events create an environment that encourages other solar instabilities to occur. Understanding the source of these events and how the energy that drives them is built up, stored, and suddenly released is critical to understanding the origins of space weather. Example events and comments of their relevance will be presented.

  11. Student and Teacher Ratings of Instructional Quality: Consistency of Ratings over Time, Agreement, and Predictive Power

    ERIC Educational Resources Information Center

    Wagner, Wolfgang; Göllner, Richard; Werth, Sarah; Voss, Thamar; Schmitz, Bernhard; Trautwein, Ulrich

    2016-01-01

    Prior research has shown that the agreement between teacher and student ratings of instructional quality is, at best, moderate, and the associations between measures of instructional quality and outcomes such as standardized achievement are typically small and somewhat mixed across both perspectives. One explanation for these low-to-moderate…

  12. Student and Teacher Ratings of Instructional Quality: Consistency of Ratings over Time, Agreement, and Predictive Power

    ERIC Educational Resources Information Center

    Wagner, Wolfgang; Göllner, Richard; Werth, Sarah; Voss, Thamar; Schmitz, Bernhard; Trautwein, Ulrich

    2016-01-01

    Prior research has shown that the agreement between teacher and student ratings of instructional quality is, at best, moderate, and the associations between measures of instructional quality and outcomes such as standardized achievement are typically small and somewhat mixed across both perspectives. One explanation for these low-to-moderate…

  13. Solar Wind and Interplanetary Disturbances

    NASA Technical Reports Server (NTRS)

    Watari, Shinichi

    2002-01-01

    This report describes basic knowledge of solar wind and interplanetary disturbances first, and then it discussed recent results from new observations and theories. At the end it presented research activities to predict interplanetary disturbances for space weather forecast.

  14. Human disturbance of the Waitomo catchment, New Zealand.

    PubMed

    van Beynen, Philip E; Bialkowska-Jelinska, Elzbieta

    2012-10-15

    The karst disturbance index (KDI) consists of 31 environmental indicators categorized within the five broad categories of geomorphology, hydrology, atmosphere, biota, and culture. This article discusses the application of the KDI to the rural karst region of Waitomo, New Zealand. Previous applications of the KDI measured disturbance to urban areas as delineated by geo-political boundaries while this study used a physical boundary of a small karst catchment. Such an approach ensures greater environmental specificity of measured disturbance levels compared to those determined according to arbitrary, politically defined areas. The study included a comparison of a local resource manager and a visiting karst expert's determinations of disturbance levels for the catchment. Overall, the Waitomo catchment was found to be moderately disturbed. The only significant, direct disturbances were deforestation and erosion; however, these lead to the indirect disturbance of cave biota, water quality and accelerated sedimentation of the catchment's waterways. We have a high degree of confidence in the validity of these results due to the ability to assess all of the applicable indicators in the index, and the consistency of scoring by both individuals who applied the index. The benefit of applying the KDI at the catchment level is the greater accuracy measuring disturbance as opposed to applying the index within geo-political boundaries that incorporate both karst and non-karst terrains. With disturbance data for a highly specific area, the Waitomo resource managers have the improved ability to effectively identify, target, remediate, and manage human disturbance of the karst landscape.

  15. A new approach to power quality and electricity reliability monitoring-case study illustrations of the capabilities of the I-GridTM system

    SciTech Connect

    Divan, Deepak; Brumsickle, William; Eto, Joseph

    2003-04-01

    This report describes a new approach for collecting information on power quality and reliability and making it available in the public domain. Making this information readily available in a form that is meaningful to electricity consumers is necessary for enabling more informed private and public decisions regarding electricity reliability. The system dramatically reduces the cost (and expertise) needed for customers to obtain information on the most significant power quality events, called voltage sags and interruptions. The system also offers widespread access to information on power quality collected from multiple sites and the potential for capturing information on the impacts of power quality problems, together enabling a wide variety of analysis and benchmarking to improve system reliability. Six case studies demonstrate selected functionality and capabilities of the system, including: Linking measured power quality events to process interruption and downtime; Demonstrating the ability to correlate events recorded by multiple monitors to narrow and confirm the causes of power quality events; and Benchmarking power quality and reliability on a firm and regional basis.

  16. Pleasant Prairie Power Plant air quality control upgrade project, Pleasant Praire, Wisconsin

    SciTech Connect

    Gebhart, S.; Pennline, D.; Brodsky, I.; Bichler, D.

    2007-10-15

    We Energies recently completed a multiyear project at its Pleasant Prairie Power Plant to add a selective catalytic reduction system to one of its two units and a scrubber to both. These projects are described. 7 figs., 1 tab.

  17. Monitoring of the quality of side-firing fibers using a special design power meter: Aquarius

    NASA Astrophysics Data System (ADS)

    van Swol, Christiaan F. P.; Verdaasdonck, Rudolf M.; Hermans, Fidel A.; van Vliet, Remco J.; Boon, Tom A.

    1995-05-01

    The treatment of Benign Prostatic Hyperplasia using the Nd:YAG laser is developing rapidly since the clinical introduction three years ago. In most cases a right angled fiber is used to deliver the laser light laterally towards the abundant prostatic tissue. The characteristics of these fibers differ, with regard to the angle at which the beam exits the fiber and the beam profile, resulting in a specific power density distribution on the tissue. During clinical use the characteristics of a fiber may change due to deterioration of the fiber tip. In this study the behavior of the various devices was monitored before and during clinical use with a special design power meter (Aquarius). The Aquarius measures the status of a right angled fiber in about fifteen seconds under clinical conditions, i.e., under water and at high input powers (40 - 80 Watt). In contrast with integrating sphere power meters specifically the primary beam is measured. The degree of deterioration of various fibers was quantified optically and thermally during clinical use. Devices using a metal mirror transmitted slightly less power than internal refraction based devices (80 versus 90 percent). The transmission of the various devices was not linear with the input power; at higher input powers (> 30 Watts) vapor bubbles, that developed at the tip of the device, decreased the transmission. During clinical use there was a large variation in decrease of transmission with regard to the total amount of energy transmitted through the fiber. However, at the end of a procedure the transmission had dropped to under 50%. The Aquarius is a powerful tool for evaluation and comparison of different laser prostatectomy devices both for clinical and experimental studies.

  18. High-average-power and high-beam-quality Innoslab picosecond laser amplifier.

    PubMed

    Xu, Liu; Zhang, Hengli; Mao, Yefei; Yan, Ying; Fan, Zhongwei; Xin, Jianguo

    2012-09-20

    We demonstrated a laser-diode, end-pumped picosecond amplifier. With effective shaping of the seed laser, we achieved 73 W amplified laser output at the pump power of 255 W, and the optical-optical efficiency was about 28%. The beam propagation factors M(2) measured at the output power of 60 W in the horizontal direction and the vertical direction were 1.5 and 1.4, respectively.

  19. Application of LMS-Based NN Structure for Power Quality Enhancement in a Distribution Network Under Abnormal Conditions.

    PubMed

    Agarwal, Rahul Kumar; Hussain, Ikhlaq; Singh, Bhim

    2017-03-16

    This paper proposes an application of a least mean-square (LMS)-based neural network (NN) structure for the power quality improvement of a three-phase power distribution network under abnormal conditions. It uses a single-layer neuron structure for the control in a distribution static compensator (DSTATCOM) to attenuate the harmonics such as noise, bias, notches, dc offset, and distortion, injected in the grid current due to connection of several nonlinear loads. This admittance LMS-based NN structure has a simple architecture which reduces the computational complexity and burden which makes it easy to implement. A DSTATCOM is a custom power device which performs various functionalities such as harmonics attenuation, reactive power compensation, load balancing, zero voltage regulation, and power factor correction. Other main contribution of this paper involves operation of the system under abnormal conditions of distribution network which means noise and distortion in voltage and imbalance in three-phase voltages at the point of interconnection. For substantiating and demonstrating the performance of proposed control approach, simulations are carried on MATLAB/Simulink software and corresponding experimental tests are conducted on a developed prototype in the laboratory.

  20. Sleep Disturbance in People with Diabetes: A Concept Analysis.

    PubMed

    Zhu, Bingqian; Vincent, Catherine; Kapella, Mary C; Quinn, Laurie; Collins, Eileen G; Ruggiero, Laurie; Park, Chang; Fritschi, Cynthia

    2017-08-09

    To clarify the meaning of sleep disturbance in people with diabetes and examine its antecedents, attributes, and consequences through concept analysis. Sleep is crucial for health, and people with diabetes are frequently beset with disturbances in their sleep. The concept of sleep disturbance in people with diabetes has not been clearly defined. The inconsistent use of sleep disturbance has created confusion and impeded our understanding of the sleep in people with diabetes. This analysis will provide a conceptual foundation of sleep disturbance in diabetes, thereby facilitating more effective means for assessment and treatment. Concept analysis. A systematic search without time restriction on the publication year was carried out using PubMed, CINAHL, PsycINFO, Web of Science, and ProQuest Dissertations and Theses. Rodgers's method of evolutionary concept analysis guided the analysis. Inductive thematic analysis was conducted to identify the attributes, antecedents, and consequences. Based on the 26 eligible studies, two major attributes are that sleep disturbance is a symptom and is characterized by impaired sleep quality and/or abnormal sleep duration. Two antecedents are diabetes-related physiological change and psychological well-being. Sleep disturbance can result in impaired daytime functioning, glucose regulation, and quality of life. Defining the concept of sleep disturbance in people with diabetes facilitates consistent use and effective communication in both practice and research. Sleep disturbance in people with diabetes is a complex symptom that includes impaired sleep quality and/or abnormal sleep duration. This paper contributes to the current knowledge of sleep in people with diabetes. Future research on antecedents and consequences of sleep disturbance are necessary for further clarifications. Findings from this paper underscore the need for nursing education, clinical assessment and effective management of sleep disturbance in people with diabetes

  1. Disturbing Behavior Checklists" Technical Manual

    ERIC Educational Resources Information Center

    Algozzine, Bob

    2012-01-01

    Ecological theorists have suggested that "disturbance" may result from an interaction between a child's behavior and reactions to that behavior within ecosystems such as schools. In this context, behavior is viewed as "disturbing" rather than "disturbed" and equal emphasis is given to the child and to individuals with whom the child interacts when…

  2. Disturbance dynamics of forested ecosystems

    Treesearch

    John A. Stanturf

    2004-01-01

    Forested ecosystems are dynamic, subject to natural developmental processes as well as natural and anthropogenic stresses and disturbances. Degradation is a related term. for lowered productive capacity from changes to forest structure of function (FAO. 2001). Degradation is not synonymous with disturbance, however; disturbance becomes degradation when natural...

  3. Influence of emitter ring manufacturing tolerances on electron beam quality of high power gyrotrons

    SciTech Connect

    Pagonakis, Ioannis Gr.; Illy, Stefan; Thumm, Manfred

    2016-08-15

    A sensitivity analysis of manufacturing imperfections and possible misalignments of the emitter ring in the gyrotron cathode structure on the electron beam quality has been performed. It has been shown that a possible radial displacement of the emitter ring of the order of few tens of microns can cause dramatic effects on the beam quality and therefore the gyrotron operation. Two different design approaches are proposed in order to achieve an electron beam which is less sensitive to manufacturing imperfections.

  4. SU-C-201-07: Towards Clinical Cherenkov Emission Dosimetry: Stopping Power-To-Cherenkov Power Ratios and Beam Quality Specification of Clinical Electron Beams

    SciTech Connect

    Zlateva, Y; Seuntjens, J; El Naqa, I

    2016-06-15

    Purpose: We propose a Cherenkov emission (CE)-based reference dosimetry method, which in contrast to ionization chamber-based dosimetry, employs spectrum-averaged electron restricted mass collision stopping power-to-Cherenkov power ratios (SCRs), and we examine Monte Carlo-calculated SCRs and beam quality specification of clinical electron beams. Methods: The EGSnrc user code SPRRZnrc was modified to compute SCRs instead of stopping-power ratios (single medium: water; cut-off: CE threshold (observing Spencer-Attix conditions); CE power: Frank-Tamm). SCRs are calculated with BEAMnrc for realistic electron beams with nominal energies of 6–22 MeV from three Varian accelerators (TrueBeam Clinac 21EX, Clinac 2100C/D) and for mono-energetic beams of energies equal to the mean electron energy at the water surface. Sources of deviation between clinical and mono-energetic SCRs are analyzed quantitatively. A universal fit for the beam-quality index R{sub 50} in terms of the depth of 50% CE C{sub 50} is carried out. Results: SCRs at reference depth are overestimated by mono-energetic values by up to 0.2% for a 6-MeV beam and underestimated by up to 2.3% for a 22-MeV beam. The variation is mainly due to the clinical beam spectrum and photon contamination. Beam angular spread has a small effect across all depths and energies. The influence of the electron spectrum becomes increasingly significant at large depths, while at shallow depths and high beam energies photon contamination is predominant (up to 2.0%). The universal data fit reveals a strong linear correlation between R{sub 50} and C{sub 50} (ρ > 0.99999). Conclusion: CE is inherent to radiotherapy beams and can be detected outside the beam with available optical technologies, which makes it an ideal candidate for out-of-beam high-resolution 3D dosimetry. Successful clinical implementation of CE dosimetry hinges on the development of robust protocols for converting measured CE to radiation dose. Our findings constitute

  5. Equal rates of disturbance cause different patterns of diversity.

    PubMed

    Svensson, J Robin; Lindegarth, Mats; Pavia, Henrik

    2009-02-01

    Empirical evidence suggests that disturbance has profound effects on the species diversity of aquatic and terrestrial assemblages. Conceptual ecological theories, such as the intermediate disturbance hypothesis (IDH), predict maximum diversity at intermediate levels of disturbance. Tests of the predictive power and generality of these models are, however, hampered by the fact that the meaning and units of "disturbance" are not clearly defined. For example, it is seldom recognized that the rate of disturbance is the product of both frequency and extent (e.g., area or volume) of disturbance events. This has important consequences for the design and interpretation of experiments on disturbance. Here we present, for the first time, an experimental design that allows for unconfounded testing of combinations of area and frequency (i.e., regimes) for a given rate of disturbance. We tested the prediction that species richness responds differently to equal rates of disturbance, depending on the specific combination of frequency and area, on marine hard-substratum assemblages. Five different rates of disturbance and two regimes (small frequent or large infrequent disturbances) were applied at three sites. The results showed that the effect of a certain rate of disturbance (1) varies strongly among assemblages and (2) also depends on the specific combination of frequency and area of disturbance events. Maximum species richness was observed at intermediate rates of disturbance at site 1 (i.e., support for the IDH), whereas there was a monotonic decline at site 2 and there was no evident pattern at site 3. The variable responses among sites were explained by differences in degree of competitive exclusion and rates of recruitment. At the site where the IDH was supported, the regime with a large proportion of the area disturbed infrequently showed higher richness, compared to the regime with a small proportion disturbed frequently. This was likely due to a stronger decrease of

  6. Vehicle Disturbance Test

    NASA Astrophysics Data System (ADS)

    Clapp, Brian

    2009-07-01

    The purpose of the VDT is to measure and characterize uncompensated environmental disturbances acting upon the HST during normal operation. The VDT is a passive test {not a forced-response test} used to obtain signatures for both externally induced {e.g. SCM, SA-3, SSM thermal gradients} and internally induced {e.g. HGA, RWA, COS and WFC3 mechanisms} disturbances affecting HST LOS pointing. The disturbances observed will be used as the nominal on-orbit disturbances in pointing control simulations until the next VDT is run.The test occurs after release, and most of the VDT can be run during the BEA period. The ?V1 sunpoint portion of the VDT usually occurs after the BEA period is complete. The VDT shall consist of two separate tests that need not occur consecutively. The overall duration of the VDT is at least 13 orbits of spacecraft time including {1} at least 8 orbits at +V3 sunpoint after achieving thermal equilibrium {at least 36-hours at +V3 sunpoint} and three out of 8-orbits have RWA Friction Compensation turned Off, and {2} at least 5 orbits at ?V1 sunpoint {all or part of this segment have RWA Friction Compensation turned Off}. At the beginning of each test, the attitude control law gains are switched to maneuver gains, and the gyros are commanded to low mode. The nominal attitude control law configuration will be restored at the end of each test.Each test is initiated via SMS execution of stored program macros in the HST flight computer to switch the attitude control law gains to low-bandwidth maneuver gains, command the gyros into low mode, terminate Velocity aberration and parallax {VAP} processing, and manage the status of on-board RWA Friction Compensation. The nominal attitude control law configuration will be restored at the end of each test via SMS execution of stored program macros. The stored program command macros are developed specifically for the VDT by the Flight Software and Pointing Control System groups.

  7. Sleep Disturbances in Neurodevelopmental Disorders.

    PubMed

    Robinson-Shelton, Althea; Malow, Beth A

    2016-01-01

    Sleep disturbances are extremely prevalent in children with neurodevelopmental disorders compared to typically developing children. The diagnostic criteria for many neurodevelopmental disorders include sleep disturbances. Sleep disturbance in this population is often multifactorial and caused by the interplay of genetic, neurobiological and environmental overlap. These disturbances often present either as insomnia or hypersomnia. Different sleep disorders present with these complaints and based on the clinical history and findings from diagnostic tests, an appropriate diagnosis can be made. This review aims to provide an overview of causes, diagnosis, and treatment of sleep disturbances in neurodevelopmental disorders that present primarily with symptoms of hypersomnia and/or insomnia.

  8. Observations and Modeling of US Power Plant NOx Emission Reductions and Their Impact on Air Quality

    NASA Astrophysics Data System (ADS)

    Frost, G. J.; Kim, S.; McKeen, S.; Hsie, E.; Trainer, M.; Heckel, A.; Richter, A.; Burrows, J.

    2007-12-01

    Nitrogen oxide (NOx) emissions resulting from fossil fuel combustion lead to unhealthy levels of near-surface ozone (O3). One of the largest US sources, electric power generation, represented about 25% of US anthropogenic NOx emissions prior to the recent implementation of pollution controls by utility companies. Continuous emission monitoring data demonstrate that overall US power plant NOx emissions decreased about 50% during the summer ozone season since the late 1990's. Space-based instruments observed declining regional NOx levels between 1999 and 2005 in response to these emission reductions. Satellite-retrieved summertime nitrogen dioxide (NO2) columns and bottom-up emission estimates show larger decreases in the Ohio River Valley, where power plants dominate NOx emissions, than in the northeast US urban corridor. Model simulations predict lower O3 across much of the eastern US in response to these emission reductions.

  9. Soil disturbance by airbags

    NASA Technical Reports Server (NTRS)

    1997-01-01

    Disturbance of the drift at the Pathfinder landing site reveals a shallow subsurface that is slightly darker but has similar spectral properties. The top set of images, in true color, shows the soils disturbed by the last bounce of the lander on its airbags before coming to rest and the marks created by retraction of the airbags. In the bottom set of images color differences have been enhanced. The mast at center is the Atmospheric Structure Instrument/Meteorology Package (ASI/MET). The ASI/MET is an engineering subsytem that acquired atmospheric data during Pathfinder's descent, and will continue to get more data through the entire landed mission. A shadow of the ASI/MET appears on a rock at left.

    Mars Pathfinder was developed and managed by the Jet Propulsion Laboratory (JPL) for the National Aeronautics and Space Administration. JPL is an operating division of the California Institute of Technology (Caltech). The Imager for Mars Pathfinder (IMP) was developed by the University of Arizona Lunar and Planetary Laboratory under contract to JPL. Peter Smith is the Principal Investigator.

  10. The often overlooked issue of statistical power: this and other issues regarding assessing importance weighting in quality of life measures.

    PubMed

    Hsieh, Chang-ming

    2015-03-01

    In the area of quality of life research, researchers may ask respondents to rate importance as well as satisfaction of various life domains (such as job and health) and use importance ratings as weights to calculate overall, or global, life satisfaction. The practice of giving more important domains more weight, known as importance weighting, has not been without controversy. Several previous studies assessed importance weighting using the analytical approach of moderated regression. This study discusses major issues related to how importance weighting has been assessed. Specifically, this study highlights that studies on importance weighting without considering statistical power are prone to type II error, i.e., failing to reject the null hypothesis of no significant weighting effect when the null hypothesis is actually false. The sample size required for adequate statistical power to detect importance weighting functions appeared larger than most previous studies could offer. Copyright © 2014 Elsevier Inc. All rights reserved.

  11. Analyzing the Effects of Component Reliability on Naval Integrated Power System Quality of Service

    DTIC Science & Technology

    2008-06-01

    Motor (Converteam, 2006) .................................... 36 Figure 10 - Shipwide IPS Architectures...situation is further complicated when considered within the framework of an integrated power system. The propulsion motors demand large quantities of...great potential gains in operating efficiency over traditional separated systems. The concept has already gained commercial acceptance in several

  12. The meaning of air quality and flue gas emission standards for public acceptance of new thermal power plants.

    PubMed

    Barbalić, N; Marijan, G; Marić, M

    2000-06-01

    For the time being only 30-40% of the electric energy supply in Croatia comes from burning fossil fuel. New capacities of 800-1400 MW for the next decade will have to rely on the exclusive use of fossil fuels in thermal power plants (TPP). Public opinion will probably have a decisive influence on the issuing of construction permissions. The potential adverse effects on air seem to be the main argument against construction of TPPs. The priority is therefore to unambiguously state what air quality is warranted in the influenced area for the whole operation period of a TPP. It is important that the public should understand the real meaning of current air quality standards and emission limits. The only known way to do it today is through comparison with the corresponding standards and limits accepted worldwide. This paper discusses some important aspects of such comparison.

  13. Examination of data collected from experiments on soil disturbance using fuzzy indicator approach

    USDA-ARS?s Scientific Manuscript database

    Soil disturbance can have important impacts on soil quality and productivity which impact management decisions. However, the extent of potential damage to soil due to soil disturbance is not always obvious. Methods are needed to determine the level of soil disturbance from soil testing. A methodo...

  14. Ultrasonication and the quality of human milk: variation of power and time of exposure.

    PubMed

    Christen, Lukas; Lai, Ching Tat; Hartmann, Peter E

    2012-08-01

    Donor human milk is pasteurized to prevent the potential risk of the transmission of pathogens to preterm infants. Currently, Holder pasteurization (human milk held at 62·5°C for 30 min) is used in most human milk banks, but has the disadvantage that it results in excessive inactivation of important bioactive components. Power-ultrasound (20-100 kHz) is an emerging technology for the preservation of foods and could be an alternative method for the treatment of human milk. The aim of this study was to investigate the effect of different ultrasound settings on the elimination of Escherichia coli and the retention of bile salt stimulated lipase (BSSL) activity. Ultrasonication with a constant power decreased Esch. coli viability exponentially over time until the processing temperature increased to sub-pasteurization level to between 51·4 and 58·5°C, then a log10 1·3 decrease was observed (P<0·05). BSSL activity decreased to 91% until a temperature of 51·4°C and then it decreased to 8% between 51·4 and 64·9°C. Ultrasonication with a constant energy and various power and exposure times showed the highest temperature (53·7°C) when treated with the longest exposure time and lowest ultrasound-power (276 s at 3·62 W) compared with 37·6°C for 39 s at 25·64 W. The findings predict that the viability of Esch. coli could be reduced by log10 5 with a minimal loss of activity of BSSL by applying 13·8 kJ of energy in 12 ml of human milk using high ultrasound power over a short exposure time to ensure that the temperature remains below the critical level for protein denaturation. Alternatively, the use of lower power settings such as the 26 W used in the present studies would require a cooling system to ensure the human milk BSSL was protected against temperature denaturation.

  15. The impact of three recent coal-fired power plant closings on Pittsburgh air quality: A natural experiment.

    PubMed

    Russell, Marie C; Belle, Jessica H; Liu, Yang

    2017-01-01

    Relative to the rest of the United States, the region of southwestern Pennsylvania, including metropolitan Pittsburgh, experiences high ambient concentrations of fine particulate matter (PM2.5), which is known to be associated with adverse respiratory and cardiovascular health impacts. This study evaluates whether the closing of three coal-fired power plants within the southwestern Pennsylvania region resulted in a significant decrease in PM2.5 concentration. Both PM2.5 data obtained from EPA ground stations in the study region and aerosol optical depth (AOD) data retrieved from the Moderate Resolution Imaging Spectroradiometer (MODIS) instruments onboard the Terra and Aqua satellites were used to investigate regional air quality from January 2011 through December 2014. The impact of the plant closings on PM2.5 concentration and AOD was evaluated using a series of generalized additive models. The model results show that monthly fuel consumption of the Elrama plant, which closed in October of 2012, and monthly fuel consumption of both the Mitchell and Hatfield's Ferry plants, which closed in October of 2013, were significant predictors of both PM2.5 concentration and AOD at EPA ground stations in the study region, after controlling for multiple meteorological factors and long-term, region-wide air quality improvements. The model's power to predict PM2.5 concentration increased from an adjusted R(2) of 0.61 to 0.68 after excluding data from ground stations with higher uncertainty due to recent increases in unconventional natural gas extraction activities. After preliminary analyses of mean PM2.5 concentration and AOD showed a downward trend following each power plant shutdown, results from a series of generalized additive models confirmed that the activity of the three plants that closed, measured by monthly fuel consumption, was highly significant in predicting both AOD and PM2.5 at 12 EPA ground stations; further research on PM2.5 emissions from unconventional

  16. Flightin maintains myofilament lattice organization required for optimal flight power and courtship song quality in Drosophila.

    PubMed

    Chakravorty, Samya; Tanner, Bertrand C W; Foelber, Veronica Lee; Vu, Hien; Rosenthal, Matthew; Ruiz, Teresa; Vigoreaux, Jim O

    2017-05-17

    The indirect flight muscles (IFMs) of Drosophila and other insects with asynchronous flight muscles are characterized by a crystalline myofilament lattice structure. The high-order lattice regularity is considered an adaptation for enhanced power output, but supporting evidence for this claim is lacking. We show that IFMs from transgenic flies expressing flightin with a deletion of its poorly conserved N-terminal domain (fln(ΔN62) ) have reduced inter-thick filament spacing and a less regular lattice. This resulted in a decrease in flight ability by 33% and in skinned fibre oscillatory power output by 57%, but had no effect on wingbeat frequency or frequency of maximum power output, suggesting that the underlying actomyosin kinetics is not affected and that the flight impairment arises from deficits in force transmission. Moreover, we show that fln(ΔN62) males produced an abnormal courtship song characterized by a higher sine song frequency and a pulse song with longer pulses and longer inter-pulse intervals (IPIs), the latter implicated in male reproductive success. When presented with a choice, wild-type females chose control males over mutant males in 92% of the competition events. These results demonstrate that flightin N-terminal domain is required for optimal myofilament lattice regularity and IFM activity, enabling powered flight and courtship song production. As the courtship song is subject to female choice, we propose that the low amino acid sequence conservation of the N-terminal domain reflects its role in fine-tuning species-specific courtship songs. © 2017 The Author(s).

  17. Satellite-Observed US Power Plant NOx Emission Reductions and Their Impact on Air Quality

    NASA Astrophysics Data System (ADS)

    Kim, S.; Heckel, A.; McKeen, S.; Frost, G.; Hsie, E.; Trainer, M.; Richter, A.; Burrows, J.; Peckham, S.; Grell, G.

    2005-05-01

    Nitrogen oxide (NOx) emissions resulting from fossil fuel combustion lead to unhealthy levels of near-surface ozone (O3). O3 exceedances in the northeast US have been associated with NOx emissions from point sources, especially coal-burning power plants. As a result, numerous programs to control point source NOx emissions in the eastern US have been implemented over the past decade. Here we assess the change of regional NOx emissions in the eastern US by comparing nitrogen dioxide (NO2) columns derived from the satellite instruments with three-dimensional regional scale chemical transport model results that include the estimated NOx emission changes. SCIAMACHY measurements are used in comparisons with WRF-Chem model simulations for 2004 because of their availability and similar horizontal resolution to the model simulations. However, to get the long term evolution of NO2 columns between 1997 and 2005, both GOME and SCIAMACHY data are utilized. Satellite observations clearly detect both year-to-year and summertime NO2 column decreases in regions impacted by power plants that have implemented NOx controls over the past decade. In the Ohio River Valley, where power plants dominate NOx emission, satellite-retrieved summertime NO2 columns and bottom-up emission estimates show larger decreases than in the northeast US urban corridor.

  18. Satellite-Observed US Power Plant NOx Emission Reductions and Their Impact on Air Quality

    NASA Astrophysics Data System (ADS)

    Kim, S.; Heckel, A.; McKeen, S.; Frost, G.; Hsie, E.; Trainer, M.; Richter, A.; Burrows, J.; Peckham, S.; Grell, G.

    2006-12-01

    Nitrogen oxide (NOx) emissions resulting from fossil fuel combustion lead to unhealthy levels of near-surface ozone (O3). O3 exceedances in the northeast US have been associated with NOx emissions from point sources, especially coal-burning power plants. As a result, numerous programs to control point source NOx emissions in the eastern US have been implemented over the past decade. Here we assess the change of regional NOx emissions in the eastern US by comparing nitrogen dioxide (NO2) columns derived from the satellite instruments with three-dimensional regional scale chemical transport model results that include the estimated NOx emission changes. SCIAMACHY measurements are used in comparisons with WRF-Chem model simulations for 2004 because of their availability and similar horizontal resolution to the model simulations. However, to get the long term evolution of NO2 columns between 1997 and 2005, both GOME and SCIAMACHY data are utilized. Satellite observations clearly detect both year-to-year and summertime NO2 column decreases in regions impacted by power plants that have implemented NOx controls over the past decade. In the Ohio River Valley, where power plants dominate NOx emission, satellite-retrieved summertime NO2 columns and bottom-up emission estimates show larger decreases than in the northeast US urban corridor.

  19. Terrestrial carbon disturbance from mountaintop mining increases lifecycle emissions for clean coal.

    PubMed

    Fox, James F; Campbell, J Elliott

    2010-03-15

    The Southern Appalachian forest region of the U.S.--a region responsible for 23% of U.S. coal production--has 24 billion metric tons of high quality coal remaining of which mountaintop coal mining (MCM) will be the primary extraction method. Here we consider greenhouse gas emissions associated with MCM terrestrial disturbance in the life-cycle of coal energy production. We estimate disturbed forest carbon, including terrestrial soil and nonsoil carbon using published U.S. Environmental Protection Agency data of the forest floor removed and U.S. Department of Agriculture--Forest Service inventory data. We estimate the amount of previously buried geogenic organic carbon brought to the soil surface during MCM using published measurements of total organic carbon and carbon isotope data for reclaimed soils, soil organic matter and coal fragments. Contrary to conventional wisdom, the life-cycle emissions of coal production for MCM methods were found to be quite significant when considering the potential terrestrial source. Including terrestrial disturbance in coal life-cycle assessment indicates that indirect emissions are at least 7 and 70% of power plant emissions for conventional and CO(2) capture and sequestration power plants, respectively. To further constrain these estimates, we suggest that the fate of soil carbon and geogenic carbon at MCM sites be explored more widely.

  20. Establishment of quality, reliability and design standards for low, medium, and high power microwave hybrid microcircuits

    NASA Technical Reports Server (NTRS)

    Robinson, E. A.

    1973-01-01

    Quality, reliability, and design standards for microwave hybrid microcircuits were established. The MSFC Standard 85M03926 for hybrid microcircuits was reviewed and modifications were generated for use with microwave hybrid microcircuits. The results for reliability tests of microwave thin film capacitors, transistors, and microwave circuits are presented. Twenty-two microwave receivers were tested for 13,500 unit hours. The result of 111,121 module burn-in and operating hours for an integrated solid state transceiver module is reported.

  1. Energy recovery during expansion of compressed gas using power plant low-quality heat sources

    DOEpatents

    Ochs, Thomas L.; O'Connor, William K.

    2006-03-07

    A method of recovering energy from a cool compressed gas, compressed liquid, vapor, or supercritical fluid is disclosed which includes incrementally expanding the compressed gas, compressed liquid, vapor, or supercritical fluid through a plurality of expansion engines and heating the gas, vapor, compressed liquid, or supercritical fluid entering at least one of the expansion engines with a low quality heat source. Expansion engines such as turbines and multiple expansions with heating are disclosed.

  2. Isotopic power supplies for space and terrestrial systems: quality assurance by Sandia National Laboratories

    SciTech Connect

    Hannigan, R.L.; Harnar, R.R.

    1981-09-01

    The Sandia National Laboratories participation in Quality Assurance (QA) programs for Radioisotopic Thermoelectric Generators which have been used in space and terrestrial systems over the past 15 years is summarized. Basic elements of the program are briefly described and recognition of assistance from other Sandia organizations is included. Descriptions of the various systems for which Sandia has had the QA responsibility are also presented. In addition, the outlook for Sandia participation in RTG programs for the next several years is noted.

  3. Interdisciplinary teamwork and the power of a quality improvement collaborative in tertiary neonatal intensive care units.

    PubMed

    Grover, Theresa R; Pallotto, Eugenia K; Brozanski, Beverly; Piazza, Anthony J; Chuo, John; Moran, Susan; McClead, Richard; Mingrone, Teresa; Morelli, Lorna; Smith, Joan R

    2015-01-01

    Significant gaps in healthcare quality and outcomes can be reduced via quality improvement collaboratives (QICs), which improve care by leveraging data and experience from multiple organizations.The Children's Hospital Neonatal Consortium Collaborative Initiatives for Quality Improvement team developed an infrastructure for neonatal QICs. We describe the structure and components of an effective multi-institutional neonatal QIC that implemented the "SLUG Bug" project designed to reduce central line-associated bloodstream infections (CLABSIs).The operational infrastructure of SLUG Bug involved 17 tertiary care neonatal intensive care units with a goal to reduce CLABSI in high-risk neonates. Clinical Practice Recommendations were produced, and the Institute of Healthcare Improvement Breakthrough Series provided the framework for the collaborative. Process measures studied the effectiveness of the collaborative structure.CLABSI rates decreased by 20% during a 12-month study period. Compliance bundle reporting exceeded 80%. A QIC score of 2.5 or more ("improvement") was achieved by 94% of centers and a score 4 or more ("significant improvement") was achieved by 35%.Frequent interactive project meetings, well-defined project metrics, continual shared learning opportunities, and individual team coaching were key QIC success components. Through a coordinated approach and committed leadership, QICs can effectively implement change and improve the care of neonates with complex diagnoses and rare diseases.

  4. CALiPER Report 20.2: Dimming, Flicker, and Power Quality Characteristics of LED PAR38 Lamps

    SciTech Connect

    None, None

    2014-03-31

    This report focuses on the flicker and power quality performance of the Series 20 lamps at full output and various dimmed levels. All of the Series 20 PAR38 lamps that manufacturers claimed to be dimmable (including all halogen lamps) were evaluated individually (one lamp at a time) both on a switch and under the control of a phase-cut dimmer designed for use with "all classes of bulbs." Measurements of luminous flux, flicker, and power quality were taken at 10 target dimmed settings and compared with operation on a switch. Because only a single unit of each product was evaluated on a single dimmer that may or may not have been recommended by its manufacturer, this report focuses on the performance of the products relative to each other, rather than the best-case performance of each lamp or variation in performance delivered from each lamp. Despite these limitations, the results suggest that LED performance is improving, and performance trends are beginning to emerge, perhaps due in part to the identification of preferred LED driver strategies for lamp products.

  5. High rates of fatigue and sleep disturbances in dystonia.

    PubMed

    Wagle Shukla, A; Brown, R; Heese, K; Jones, J; Rodriguez, R L; Malaty, I M; Okun, M S; Kluger, B M

    2016-10-01

    Nonmotor symptoms in dystonia are increasingly recognized to impair the quality of life. The primary objective of this study was to determine the prevalence of fatigue and sleep disturbances in dystonia and to ascertain their impact on quality of life using standardized questionnaires. Dystonia patients presenting to a Botulinum toxin clinic were prospectively administered Fatigue Severity Scale (FSS), Multidimensional Fatigue Inventory (MFI), Epworth Sleepiness Scale (ESS) and Parkinson's Disease Sleep Scale (PDSS) for assessment of fatigue and sleep disturbances. Health-related Quality of life (HRQOL) was determined using MOS SF-36 scale and depressive symptoms were assessed using the Beck Depression Inventory II. Ninety-one patients with dystonia participated (66 women, 25 men, mean age 60 ± 17 years). Nine subjects had generalized dystonia, 18 segmental dystonia and 64 had focal dystonia. Moderate to severe fatigue was present in 43% of the cohort (FSS), excessive daytime somnolence in 27% (ESS) and other sleep disturbances in 26% (PDSS). FSS and MFI scores correlated significantly with HRQOL even when controlled for depression and sleep disturbances. Excessive daytime somnolence and nocturnal sleep disturbances correlated significantly with the HRQOL; however, these effects were not seen for daytime somnolence when controlled for depression. Psychometric testing found adequate reliabilities and convergent validities for both fatigue and sleep scales. Fatigue and sleep disturbances revealed high prevalence rates in this large, first of its dystonia study. They negatively impacted the quality of life even when controlled for comorbid depression.

  6. Sleep Disturbances in Mood Disorders.

    PubMed

    Rumble, Meredith E; White, Kaitlin Hanley; Benca, Ruth M

    2015-12-01

    The article provides an overview of common and differentiating self-reported and objective sleep disturbances seen in mood-disordered populations. The importance of considering sleep disturbances in the context of mood disorders is emphasized, because a large body of evidence supports the notion that sleep disturbances are a risk factor for onset, exacerbation, and relapse of mood disorders. In addition, potential mechanisms for sleep disturbance in depression, other primary sleep disorders that often occur with mood disorders, effects of antidepressant and mood-stabilizing drugs on sleep, and the adjunctive effect of treating sleep in patients with mood disorders are discussed. Copyright © 2015 Elsevier Inc. All rights reserved.

  7. Climate Change and Disturbance Interactions

    NASA Astrophysics Data System (ADS)

    McKenzie, Don; Allen, Craig D.

    2007-05-01

    Workshop on Climate Change and Disturbance Interactions in Western North America, Tucson, Ariz., 12-15 February 2007 Warming temperatures across western North America, coupled with increased drought, are expected to exacerbate disturbance regimes, particularly wildfires, insect outbreaks, and invasions of exotic species. Many ecologists and resource managers expect ecosystems to change more rapidly from disturbance effects than from the effects of a changing climate by itself. A particular challenge is to understand the interactions among disturbance regimes; for example, how will massive outbreaks of bark beetles, which kill drought-stressed trees by feeding on cambial tissues, increase the potential for large severe wildfires in a warming climate?

  8. Continuous uniformly finite time exact disturbance observer based control for fixed-time stabilization of nonlinear systems with mismatched disturbances

    PubMed Central

    Liu, Chongxin; Liu, Hang

    2017-01-01

    This paper presents a continuous composite control scheme to achieve fixed-time stabilization for nonlinear systems with mismatched disturbances. The composite controller is constructed in two steps: First, uniformly finite time exact disturbance observers are proposed to estimate and compensate the disturbances. Then, based on adding a power integrator technique and fixed-time stability theory, continuous fixed-time stable state feedback controller and Lyapunov functions are constructed to achieve global fixed-time system stabilization. The proposed control method extends the existing fixed-time stable control results to high order nonlinear systems with mismatched disturbances and achieves global fixed-time system stabilization. Besides, the proposed control scheme improves the disturbance rejection performance and achieves performance recovery of nominal system. Simulation results are provided to show the effectiveness, the superiority and the applicability of the proposed control scheme. PMID:28406966

  9. High beam quality and high power CO II lasers for technologies and medicine

    NASA Astrophysics Data System (ADS)

    Vasiltsov, V. V.; Berishvili, I. I.; Galushkin, M. G.; Golubev, V. S.; Panchenko, V. Ya.; Ulyanov, V. A.; Zinina, N. N.; Vakhromeeva, M. N.; Vakhrameeva, A. Y.

    2007-06-01

    The technical characteristics of the new three models of diffusion-cooled multichannel waveguide industrial CO II lasers excited with acoustic-frequency ac discharge are presented. The industrial lasers of this type have been developed for years at ILIT RAS. Generation of low (to 400 W) average power proved to be technically realizable through air cooling of the oscillator, which makes the laser performance even more attractive. The above lasers can be used to advantage in the laser processing systems intended for precision cutting of metallic (thickness to 10 mm) and non-metallic (thickness to 40 mm) materials; welding; surfacing and fabrication of parts from composite and metallic powder materials. The paper also provides the description and the technical characteristics of intellectual medical cardio-surgery laser systems of "Perfocor" family, developed at ILIT RAS for the transmyocardial laser revascularization (TMLR) which presents a promising method to cure the ischemic disease of heart. The clinical results (more than 800 operations) are presented. Owing to application of the TMLR technique the death rate at the A.N. Bakoulev Center is the lowest in the world. The project of a new CO II laser surgery plant "Khirurg" is discussed that would deliver up to 200 W power and is based on the model TL-300 with a system of biotissue diagnostics.

  10. Effect of AC target power on AlN film quality

    SciTech Connect

    Knisely, Katherine Grosh, Karl

    2014-09-01

    The influence of alternating current (AC) target power on film stress, roughness, and x-ray diffraction rocking curve full width half maximum (FWHM) was examined for AlN films deposited using S-gun magnetron sputtering on insulative substrates consisting of Si wafers with 575 nm thermal oxide. As the AC target power was increased from 5 to 8 kW, the deposition rate increased from 9.3 to 15.9 A/s, film stress decreased from 81 to −170 MPa, and the rocking curve FWHM increased from 0.98 to 1.03°. AlN film behavior is observed to change with target life; films deposited at 200 kWh target life were approximately 40 MPa more compressive and had 0.02° degree higher rocking curve FWHM values than films deposited at 130 kWh. AlN films deposited in two depositions were compared with films deposited in a single deposition, in order to better characterize the growth behavior and properties of AlN films deposited on an existing AlN film, which is not well understood. Two deposition films, when compared with single deposition films, showed no variation in residual stress trends or grain size behavior, but the average film roughness increased from 0.7 to 1.4 nm and rocking curve FWHM values increased by more than 0.25°.

  11. The High-Risk (Disturbed and Disturbing) College Student

    ERIC Educational Resources Information Center

    Hollingsworth, Kathy R.; Dunkle, John H.; Douce, Louise

    2009-01-01

    The disturbed and disturbing college student causes the most vexing concerns for student affairs administrators. The Assessment-Intervention of Student Problems (AISP) model offers a useful and easily understood framework for dealing with the various challenges of this high-risk student population. This chapter focuses on changes that have…

  12. The High-Risk (Disturbed and Disturbing) College Student

    ERIC Educational Resources Information Center

    Hollingsworth, Kathy R.; Dunkle, John H.; Douce, Louise

    2009-01-01

    The disturbed and disturbing college student causes the most vexing concerns for student affairs administrators. The Assessment-Intervention of Student Problems (AISP) model offers a useful and easily understood framework for dealing with the various challenges of this high-risk student population. This chapter focuses on changes that have…

  13. Changes in the quality of life in severely disabled people following provision of powered indoor/outdoor chairs.

    PubMed

    Davies, A; De Souza, L H; Frank, A O

    2003-03-18

    To determine the benefits for patients who received an electric powered inoor/outdoor chair (EPIOC) and to quantify their perceived changes to their quality of life. Community-based cohort study of all patients provided with an EPIOC over 4 months; and followed up about 3 months later in a community served by a regional wheelchair service in North West London (population about 3.1 million) using the EuroQol EQ-5D with visual analogue scales for each of the five dimensions of the EQ-5D. Sixty-four wheelchair users were assessed initially and 51 completed follow up. Chair users showed no significant improvement in health state as measured by the EQ-5D after EPIOC provision. The visual analogue scales (VASs) indicated that, although perceived overall health state, independence and social life did not appear to improve, the dimensions of mobility, quality of life and pain/discomfort improved significantly on provision of an EPIOC. EPIOC users reported significant improvements in several important aspects of their lives; not just in mobility (as expected) but also in reduction of pain and discomfort. The use of VASs provided a more holistic set of outcome measures that demonstrate quality of life benefits beyond that of health state alone.

  14. A Comparative Analysis for Selection of Appropriate Mother Wavelet for Detection of Stationary Disturbances

    NASA Astrophysics Data System (ADS)

    Kamble, Saurabh Prakash; Thawkar, Shashank; Gaikwad, Vinayak G.; Kothari, D. P.

    2017-08-01

    Detection of disturbances is the first step of mitigation. Power electronics plays a crucial role in modern power system which makes system operation efficient but it also bring stationary disturbances in the power system and added impurities to the supply. It happens because of the non-linear loads used in modern day power system which inject disturbances like harmonic disturbances, flickers, sag etc. in power grid. These impurities can damage equipments so it is necessary to mitigate these impurities present in the supply very quickly. So, digital signal processing techniques are incorporated for detection purpose. Signal processing techniques like fast Fourier transform, short-time Fourier transform, Wavelet transform etc. are widely used for the detection of disturbances. Among all, wavelet transform is widely used because of its better detection capabilities. But, which mother wavelet has to use for detection is still a mystery. Depending upon the periodicity, the disturbances are classified as stationary and non-stationary disturbances. This paper presents the importance of selection of mother wavelet for analyzing stationary disturbances using discrete wavelet transform. Signals with stationary disturbances of various frequencies are generated using MATLAB. The analysis of these signals is done using various mother wavelets like Daubechies and bi-orthogonal wavelets and the measured root mean square value of stationary disturbance is obtained. The measured value obtained by discrete wavelet transform is compared with the exact RMS value of the frequency component and the percentage differences are presented which helps to select optimum mother wavelet.

  15. The power of cross-functional teams in driving total quality

    NASA Astrophysics Data System (ADS)

    McClung, Tim M.; McMaster, Tom J.

    Garrett Canada, a Division of Allied-Signal Aerospace Canada, has been a member of the Canadian aerospace industry for 40 years. Although Garrett Canada has always been a profitable division with a solid market share, the changing and turbulent business environment and globalization of the aerospace industry has created new demands and challenges. The marketplace is demanding faster introduction of new products, as well as shorter leadtimes for repairs and spares. It was recognized that reducing cycle times for new products and for ongoing production would not only satisfy our customers, it would also enhance our business performance through reduced inventories, lower past due, and more responsiveness to change. It was evident that drastic function changes were required if we were to maintain our position as a premier aerospace supplier. The challenge was to convert a stable, somewhat slow-paced work environment with strong functional boundaries into a boundaryless world class team functioning in a total quality environment and focused on customer satisfaction. Complete and uncompromised customer satisfaction has become our driving force, with Total Quality being our engine to continuously improve our processes and increase our speed. The way in which this transition has been brought about is the subject of this presentation.

  16. The power of cross-functional teams in driving total quality

    NASA Technical Reports Server (NTRS)

    Mcclung, Tim M.; Mcmaster, Tom J.

    1992-01-01

    Garrett Canada, a Division of Allied-Signal Aerospace Canada, has been a member of the Canadian aerospace industry for 40 years. Although Garrett Canada has always been a profitable division with a solid market share, the changing and turbulent business environment and globalization of the aerospace industry has created new demands and challenges. The marketplace is demanding faster introduction of new products, as well as shorter leadtimes for repairs and spares. It was recognized that reducing cycle times for new products and for ongoing production would not only satisfy our customers, it would also enhance our business performance through reduced inventories, lower past due, and more responsiveness to change. It was evident that drastic function changes were required if we were to maintain our position as a premier aerospace supplier. The challenge was to convert a stable, somewhat slow-paced work environment with strong functional boundaries into a boundaryless world class team functioning in a total quality environment and focused on customer satisfaction. Complete and uncompromised customer satisfaction has become our driving force, with Total Quality being our engine to continuously improve our processes and increase our speed. The way in which this transition has been brought about is the subject of this presentation.

  17. Total combining power: Technique for the evaluation of the quality control process of clostridiosis vaccines.

    PubMed

    Brandi, Igor Viana; Santos, Eliane Macedo Sobrinho; Carvalho, Bruna Mara Aparecida de; Durães, Carla Adriana Ferreira; Farias, Paula Karoline Soares; Sari, Roger Shoji; Cangussu, Alex Sander Rodrigues; Pessoa, Adalberto

    2016-11-01

    An efficient technique for evaluation of the quality control of vaccines against clostridiosis is described in this study. This technique is capable of quantifying the toxoid of the bacterium Clostridium perfringens Type D, which is commonly found within these vaccines. The described method is performed in vivo to quantify the toxoid, replacing the current predominant approaches that use the titration of toxins before the inactivation process. This method is based on the partial neutralization of a determined dose of antitoxin by testing different doses of the toxoid. In order to guarantee its reliability, it is essential for the technique to be validated. Thus, the technique was tested using the following validation parameters: specificity and selectivity, detection limit, linear correlation, precision and robustness, in agreement with the requirements of regulatory agencies and international committees from around the world. The method was found to be specific, selective, robust, precise, and linear inside a specific concentration range. Therefore, it could be applied to the quality control of clostridiosis vaccines with satisfactory results.

  18. Finding disturbances in on-farm biogas production.

    PubMed

    Antonio, Pereira-Querol Marco; Laura, Seppänen

    2012-01-01

    When implementing innovations, disturbances are very likely to take place. Disturbances are undesirable because they can lead to unwanted outcomes, such as economic losses and work overload to workers. However, they can be powerful opportunities for learning and re-designing innovations. Here, we will present activity theoretical tools for analyzing disturbances in a way that they could be used as learning opportunities. We illustrate the proposed tools by analyzing a disturbance that took place during the implementation of a project of biogas production. By interpreting the disturbance process with a network of activity systems, we found that on-farm disturbances were formed as ruptures, innovations and asynchronies originated in other activity systems. This finding suggests that disturbances are outcomes of the functioning of networks, rather than simple results of failure of individuals or technical devices. The proposed tools could be used in interventions to help practitioners and ergonomists to recognize the systemic and networked nature of problems, and therefore, realize that they may require the collaboration of actors from different activities. In this sense, disturbances may be turned into opportunities for learning and developing innovations. We conclude by discussing how the method could be used in ergonomic design and intervention.

  19. LANDSAT-4 image data quality analysis for energy related applications. [nuclear power plant sites

    NASA Technical Reports Server (NTRS)

    Wukelic, G. E. (Principal Investigator)

    1983-01-01

    No useable LANDSAT 4 TM data were obtained for the Hanford site in the Columbia Plateau region, but TM simulator data for a Virginia Electric Company nuclear power plant was used to test image processing algorithms. Principal component analyses of this data set clearly indicated that thermal plumes in surface waters used for reactor cooling would be discrenible. Image processing and analysis programs were successfully testing using the 7 band Arkansas test scene and preliminary analysis of TM data for the Savanah River Plant shows that current interactive, image enhancement, analysis and integration techniques can be effectively used for LANDSAT 4 data. Thermal band data appear adequate for gross estimates of thermal changes occurring near operating nuclear facilities especially in surface water bodies being used for reactor cooling purposes. Additional image processing software was written and tested which provides for more rapid and effective analysis of the 7 band TM data.

  20. Contribution of concentrator photovoltaic installations to grid stability and power quality

    NASA Astrophysics Data System (ADS)

    del Toro García, Xavier; Roncero-Sánchez, Pedro; Torres, Alfonso Parreño; Vázquez, Javier

    2012-10-01

    Large-scale integration of Photovoltaic (PV) generation systems, including Concentrator Photovoltaic (CPV) technologies, will require the contribution and support of these technologies to the management and stability of the grid. New regulations and grid codes for PV installations in countries such as Spain have recently included dynamic voltage control support during faults. The PV installation must stay connected to the grid during voltage dips and inject reactive power in order to enhance the stability of the system. The existing PV inverter technologies based on the Voltage-Source Converter (VSC) are in general well suited to provide advanced grid-support characteristics. Nevertheless, new advanced control schemes and monitoring techniques will be necessary to meet the most demanding requirements.

  1. Instantaneous phasor method for obtaining instantaneous balanced fundamental components for power quality control and continuous diagnostics

    SciTech Connect

    Hsu, J.S.

    1997-07-01

    This paper introduces an instantaneous phasor method that considers three phases simultaneously. This method produces the instantaneous fundamental balanced components of the polluted voltages or currents. A figure shows three-phase voltages that contain 5% of fundamental magnitude for each order of the 3rd, 5th, 7th, 9th and the 11th harmonics, respectively. Additionally, the voltages have 5% unbalance for all voltage components. A 10% fundamental-frequency zero-sequence component, as well as a 10% fundamental-frequency negative-sequence component are also added to the phase voltages. Furthermore, certain high-frequency pulses arbitrarily given at 5% of a 35th order to represent a possible carrier frequency of power electronic circuits are also included.

  2. Reliability and Power Quality Evaluation of High-Voltage Supplied Customer

    NASA Astrophysics Data System (ADS)

    Yoshino, Jun; Kita, Hiroyuki; Tanaka, Eiichi; Hasegawa, Jun; Kubo, Hiroshi; Yonaga, Shigeru

    Recently, a number of electric consumers have concerned about the reliability of electricity to be served. For example, some consumers need the electricity with a higher reliability by the automation of manufacturing processes. On the other hand, some consumers need the electricity of a cheaper price even if the reliability becomes a little worse. Under such circumstances, it is necessary that power suppliers evaluate the needs of every consumers precisely and propose the most desirable measures for meeting their requirements. This paper develops a tool to analyze the reliability for high-voltage supplied consumers quantitatively. Further, this paper presents a method for evaluating the outage cost of consumers to help them choose the most appropriate measures for maintaining the reliability. The proposed method applies the fuzzy reasoning approach. The validity of the proposed method is ascertained through some numerical simulations.

  3. Autonomic disturbances in narcolepsy.

    PubMed

    Plazzi, Giuseppe; Moghadam, Keivan Kaveh; Maggi, Leonardo Serra; Donadio, Vincenzo; Vetrugno, Roberto; Liguori, Rocco; Zoccoli, Giovanna; Poli, Francesca; Pizza, Fabio; Pagotto, Uberto; Ferri, Raffaele

    2011-06-01

    Narcolepsy is a clinical condition characterized mainly by excessive sleepiness and cataplexy. Hypnagogic hallucinations and sleep paralysis complete the narcoleptic tetrad; disrupted night sleep, automatic behaviors and weight gain are also usual complaints. Different studies focus on autonomic changes or dysfunctions among narcoleptic patients, such as pupillary abnormalities, fainting spells, erectile dysfunction, night sweats, gastric problems, low body temperature, systemic hypotension, dry mouth, heart palpitations, headache and extremities dysthermia. Even if many studies lack sufficient standardization or their results have not been replicated, a non-secondary involvement of the autonomic nervous system in narcolepsy is strongly suggested, mainly by metabolic and cardiovascular findings. Furthermore, the recent discovery of a high risk for overweight and for metabolic syndrome in narcoleptic patients represents an important warning for clinicians in order to monitor and follow them up for their autonomic functions. We review here studies on autonomic functions and clinical disturbances in narcoleptic patients, trying to shed light on the possible contribute of alterations of the hypocretin system in autonomic pathophysiology.

  4. Ionospheric disturbance dynamo

    SciTech Connect

    Blanc, M.; Richmond, A.D.

    1980-04-01

    A numerical simulation study of the thermospheric winds produced by auroral heating during magnetic storms, and of their global dynamo effects, establishes the main features of the ionospheric disturbanc dynamo. Driven by auroral heating, a Hadley cell is created with equatorward winds blowing above about 120 km at mid-latitudes. The transport of angular momentum by these winds produces a subrotation of the midlatitude thermosphere, or westward motion with respect to the earth. The westward winds in turn drive equatorward Pedersen currents which accumulate charge toward the equator, resulting in the generation of a poleward electric field, a westward E x B drift, and an eastward current. When realistic local time conductivity variations are simulated, the eastward mid-latitude current is found to close partly via lower latitudes, resulting in an 'anti-Sq' type of current vortex. Both electric field and current at low latitudes thus vary in opposition to their normal quiet-day behavior. This total pattern of distrubance winds, electric fields, and currents is superimposed upon the background quiet-day pattern. When the neutral winds are artificially confined on the nightside, the basic pattern of predominantly westward E x B plasma drifts still prevails on the nightside but no longer extends into the dayside. Considerable observational evidence exists, suggesting that the ionospheric disturbance dynamo has an appreciable influence on storm-time ionospheric electric fields at middle and low latitudes.

  5. Parkinson's Disease and Sleep/Wake Disturbances

    PubMed Central

    Swick, Todd J.

    2012-01-01

    Parkinson's disease (PD) has traditionally been characterized by its cardinal motor symptoms of bradykinesia, rigidity, resting tremor, and postural instability. However, PD is increasingly being recognized as a multidimensional disease associated with myriad nonmotor symptoms including autonomic dysfunction, mood disorders, cognitive impairment, pain, gastrointestinal disturbance, impaired olfaction, psychosis, and sleep disorders. Sleep disturbances, which include sleep fragmentation, daytime somnolence, sleep-disordered breathing, restless legs syndrome (RLS), nightmares, and rapid eye movement (REM) sleep behavior disorder (RBD), are estimated to occur in 60% to 98% of patients with PD. For years nonmotor symptoms received little attention from clinicians and researchers, but now these symptoms are known to be significant predictors of morbidity in determining quality of life, costs of disease, and rates of institutionalization. A discussion of the clinical aspects, pathophysiology, evaluation techniques, and treatment options for the sleep disorders that are encountered with PD is presented. PMID:23326757

  6. Sleep disturbance in early HIV infection.

    PubMed

    Darko, D F; Mitler, M M; White, J L

    1995-10-01

    Immune proteins may have a role in HIV-related sleep disturbance. Observations of two notable sleep changes, increase in slow wave sleep and the need for too much sleep, during early stage HIV infection prompted researchers to investigate the neurological changes occurring with sleep structure alterations. When psychiatric, psychological, medical, and pharmacological variables are excluded, researchers begin to examine the effect of HIV infection on the brain itself. While reasons for sleep structure distortion remain unknown, new data suggests that irregular levels of peptides may be involved. Upcoming clinical trials will evaluate medications for efficacy in treating HIV-related sleep disturbance. This could lead to therapies that restore sleep and improve quality of life.

  7. Educating Emotionally Disturbed Children: Readings.

    ERIC Educational Resources Information Center

    Dupont, Henry, Ed.

    Designed to introduce the classroom teacher to a clinical teaching approach with the emotionally disturbed child and to encourage critical discussion of current practices and theories, the collection of readings presents selected dimensions of emotional disturbance such as personality patterns, learning disabilities, and minimal brain damage.…

  8. Educating Emotionally Disturbed Children: Readings.

    ERIC Educational Resources Information Center

    Dupont, Henry, Ed.

    Designed to introduce the classroom teacher to a clinical teaching approach with the emotionally disturbed child and to encourage critical discussion of current practices and theories, the collection of readings presents selected dimensions of emotional disturbance such as personality patterns, learning disabilities, and minimal brain damage.…

  9. Subclassification of School Phobic Disturbances.

    ERIC Educational Resources Information Center

    Atkinson, Leslie; And Others

    The confusion surrounding all aspects of school refusal may rest partly on the misguided assumption that the disturbance represents a single syndrome. Five consistently emerging variables which may help distinguish among school phobic types were abstracted from the literature: extensiveness of disturbance, mode of onset, age, fear source, and…

  10. Ecstasy use and self-reported disturbances in sleep.

    PubMed

    Ogeil, Rowan P; Rajaratnam, Shantha M W; Phillips, James G; Redman, Jennifer R; Broadbear, Jillian H

    2011-10-01

    Ecstasy users report a number of complaints after its use including disturbed sleep. However, little is known regarding which attributes of ecstasy use are associated with sleep disturbances, which domains of sleep are affected or which factors may predict those ecstasy users likely to have poor sleep quality and/or excessive daytime sleepiness. This study examined questionnaire responses of social drug users (n = 395) to the Pittsburgh Sleep Quality Index and the Epworth Sleepiness Scale. A significant proportion of ecstasy users (69.5%) had Pittsburgh Sleep Quality Index scores above the threshold used to identify sleep disturbance. Although frequency of ecstasy use did not affect the degree of reported sleep disturbance, participants who used larger amounts of ecstasy had poorer sleep. In addition, participants who perceived harmful consequences arising from their ecstasy use or had experienced remorse following ecstasy use had poorer sleep. Clinically relevant levels of sleep disturbance were still evident after controlling for polydrug use. Risk factors for poor sleep quality were younger age, injury post-ecstasy use and having been told to cut down on ecstasy use. Many ecstasy users report poor sleep quality, which likely contributes to the negative effects reported following ecstasy use. Copyright © 2011 John Wiley & Sons, Ltd.

  11. Environment Quality: Impact From Traffic, Power Plant and Land Morphology, a Case Study of Prishtina

    NASA Astrophysics Data System (ADS)

    Bajcinovci, Bujar

    2017-05-01

    Environmental air pollution is a global health concern, a complex phenomenon which is directly reflected on public health, economic and human development. Environmental air pollution has been drastically multiplied, followed by the beginning of the new Millennia in Prishtina, the capital city of the Kosovo. The new millennium began as a crucial activity for the city of Prishtina in terms of demographic, human geography, social and economic phenomena. The presented study aims to determine prevalent traffic and land morphology composition attributes, which have influenced and continue to have environmental impact in the city of Prishtina. According to the conceptual findings from the empirical observations, the heavy city traffic and the land morphology structure, determine the urban air pollution level. Prishtina is generally polluted due to its geomorphic position in relation to the power plants Kosovo A, and Kosova B. The impact of the above cited factors, is even bigger when the dominant winds prevail through valley, which encompasses the city. The findings from this paper propose the necessity of careful driven urban solutions.

  12. Western Disturbances: A review

    NASA Astrophysics Data System (ADS)

    Dimri, A. P.; Niyogi, D.; Barros, A. P.; Ridley, J.; Mohanty, U. C.; Yasunari, T.; Sikka, D. R.

    2015-06-01

    Cyclonic storms associated with the midlatitude Subtropical Westerly Jet (SWJ), referred to as Western Disturbances (WDs), play a critical role in the meteorology of the Indian subcontinent. WDs embedded in the southward propagating SWJ produce extreme precipitation over northern India and are further enhanced over the Himalayas due to orographic land-atmosphere interactions. During December, January, and February, WD snowfall is the dominant precipitation input to establish and sustain regional snowpack, replenishing regional water resources. Spring melt is the major source of runoff to northern Indian rivers and can be linked to important hydrologic processes from aquifer recharge to flashfloods. Understanding the dynamical structure, evolution-decay, and interaction of WDs with the Himalayas is therefore necessary to improve knowledge which has wide ranging socioeconomic implications beyond short-term disaster response including cold season agricultural activities, management of water resources, and development of vulnerability-adaptive measures. In addition, WD wintertime precipitation provides critical mass input to existing glaciers and modulates the albedo characteristics of the Himalayas and Tibetan Plateau, affecting large-scale circulation and the onset of the succeeding Indian Summer Monsoon. Assessing the impacts of climate variability and change on the Indian subcontinent requires fundamental understanding of the dynamics of WDs. In particular, projected changes in the structure of the SWJ will influence evolution-decay processes of the WDs and impact Himalayan regional water availability. This review synthesizes past research on WDs with a perspective to provide a comprehensive assessment of the state of knowledge to assist both researchers and policymakers, and context for future research.

  13. Computed tomography: a powerful imaging technique in the fields of dimensional metrology and quality control

    NASA Astrophysics Data System (ADS)

    Probst, Gabriel; Boeckmans, Bart; Dewulf, Wim; Kruth, Jean-Pierre

    2016-05-01

    X-ray computed tomography (CT) is slowly conquering its space in the manufacturing industry for dimensional metrology and quality control purposes. The main advantage is its non-invasive and non-destructive character. Currently, CT is the only measurement technique that allows full 3D visualization of both inner and outer features of an object through a contactless probing system. Using hundreds of radiographs, acquired while rotating the object, a 3D representation is generated and dimensions can be verified. In this research, this non-contact technique was used for the inspection of assembled components. A dental cast model with 8 implants, connected by a screwed retained bar made of titanium. The retained bar includes a mating interface connection that should ensure a perfect fitting without residual stresses when the connection is fixed with screws. CT was used to inspect the mating interfaces between these two components. Gaps at the connections can lead to bacterial growth and potential inconvenience for the patient who would have to face a new surgery to replace his/hers prosthesis. With the aid of CT, flaws in the design or manufacturing process that could lead to gaps at the connections could be assessed.

  14. Ground-water quality in Bannock, Bear Lake, Caribou, and part of Power counties, southeastern Idaho

    USGS Publications Warehouse

    Seitz, H.R.; Norvitch, R.F.

    1979-01-01

    The 103 wells sampled during the study establish a quasi-network that could be resampled in the future to document and analyze changes in ground-water quality in the southeastern Idaho study area. The main aquifers are categorized as alluvium of Quaternary age, basalt of Quaternary and (or) Tertiary age, rocks of the Salt Lake Formation of Tertiary age, and undifferentiated bedrock of pre-Tertiary age. Dissolved solids, hardness, nitrite plus nitrate as nitrogen, and chloride concentrations in the ground waters ranged from 165 to 1,690; 78 to 1,700; 0 to 29; and 1.9 to 360 milligrams per liter, respectively. The areal distributions of these constituents are shown on maps. The range and median values of these same constituents are tabulated by aquifer occurrence. Some of the most mineralized and hardest waters occur in the basalt aquifer near travertine deposits (or terraces), which are composed of calcium carbonate precipitates from mineral springs. For irrigation purposes, all the waters are classified as having low-sodium hazard. Most have medium- to high-salinity hazard. (Woodard-USGS)

  15. Development of a coal quality analyzer for application to power plants based on laser-induced breakdown spectroscopy

    NASA Astrophysics Data System (ADS)

    Zhang, Lei; Gong, Yao; Li, Yufang; Wang, Xin; Fan, Juanjuan; Dong, Lei; Ma, Weiguang; Yin, Wangbao; Jia, Suotang

    2015-11-01

    It is vitally important for a power plant to determine the coal property rapidly to optimize the combustion process. In this work, a fully software-controlled laser-induced breakdown spectroscopy (LIBS) based coal quality analyzer comprising a LIBS apparatus, a sampling equipment, and a control module, has been designed for possible application to power plants for offering rapid and precise coal quality analysis results. A closed-loop feedback pulsed laser energy stabilization technology is proposed to stabilize the Nd: YAG laser output energy to a preset interval by using the detected laser energy signal so as to enhance the measurement stability and applied in a month-long monitoring experiment. The results show that the laser energy stability has been greatly reduced from ± 5.2% to ± 1.3%. In order to indicate the complex relationship between the concentrations of the analyte of interest and the corresponding plasma spectra, the support vector regression (SVR) is employed as a non-linear regression method. It is shown that this SVR method combined with principal component analysis (PCA) enables a significant improvement in cross-validation accuracy by using the calibration set of coal samples. The root mean square error for prediction of ash content, volatile matter content, and calorific value decreases from 2.74% to 1.82%, 1.69% to 1.22%, and 1.23 MJ/kg to 0.85 MJ/kg, respectively. Meanwhile, the corresponding average relative error of the predicted samples is reduced from 8.3% to 5.48%, 5.83% to 4.42%, and 5.4% to 3.68%, respectively. The enhanced levels of accuracy obtained with the SVR combined with PCA based calibration models open up avenues for prospective prediction in coal properties.

  16. Modelling air quality impact of a biomass energy power plant in a mountain valley in Central Italy

    NASA Astrophysics Data System (ADS)

    Curci, Gabriele; Cinque, Giovanni; Tuccella, Paolo; Visconti, Guido; Verdecchia, Marco; Iarlori, Marco; Rizi, Vincenzo

    2012-12-01

    In this study, we investigate the potential impact on local air quality of a biomass power plant, which is planned for installation near L'Aquila, a city of 70,000 people located in a mountain valley in Central Italy. The assessment is carried out by applying a one year simulation with the CALPUFF model, following the recommendations of the U. S. Environmental Protection Agency. Meteorological input is produced with CALMET model, fed with both MM5 meteorological fields at 3 km resolution and wind observations from a surface weather station. We estimate small (<0.5 μg m-3) annual average increments to SO2, NO2 and PM10 ambient levels over the domain of interest, but significant (up to 50% for NO2) enhancements and several violations (up to 141 for NO2) of hourly limits for human protection within 1.5 km from the source. These results anticipate a larger negative effect on local air quality than those published by the building firm of the plant. We also suggest that a minimum distance of 5 km from the nearest residential area would represent a significant decrease of population exposure.

  17. Relationship of electric power quality to milk production of dairy herds - field study with literature review.

    PubMed

    Hillman, Donald; Stetzer, Dave; Graham, Martin; Goeke, Charles L; Mathson, Kurt E; Vanhorn, Harold H; Wilcox, Charles J

    2013-03-01

    on rural power lines.

  18. International Normalized Ratio Variability: A Measure of Anticoagulation Quality or a Powerful Mortality Predictor.

    PubMed

    Vanerio, Gabriel

    2015-10-01

    As atrial fibrillation (AF) carries twice the mortality hazard when compared with a similar population without diagnosed AF, the importance of risk stratifying is obvious. Several variables are related to outcome: age, comorbidities, and use of several medications, particularly oral anticoagulants. The CHA2DS2VASc score is an extremely useful tool to predict thromboembolic events and also mortality. The international normalized ratio (INR) variability is a treatment efficacy variable also associated with morbidity in patients receiving warfarin. The objective of the study is to compare the prognostic value of the CHA2DS2VASc versus the INR variability or its combination to predict mortality. In this observational study, we analyzed 589 patients from our Atrial Fibrillation Cohort, all on warfarin for more than 1 year and had more than 5 INRs performed in the last 2 years. The CHA2DS2VASc, HAS-BLED, and SAMe-TT2R2 scores were calculated as well as the INR variability using the time-in-therapeutic-range (TTR), the percentage of INRs (%INRs) within range, and the standard deviation of the INRs (SDINRs). Kaplan-Meier survival curves were plotted via different cutoff points. The mean TTR was 53 ± 23%; 34.6% of the patients had a TTR above 64%. The mean %INRs in range was 50.2 ± 20.2; 17.3% of the population had %INRs in range above 70%. The mean SDINRs was .84 ± .54, and 38.4% had SDINRs below .79. Of 598, 139 (22%) discontinued warfarin treatment. Death was responsible for almost 50% of treatment discontinuation. Of 598, 68 patients died during the study period (11.5 %); the most frequent causes of death were heart failure (30%), bleeding (17%), and ischemic stroke (15%). Patient survival had a correlation with TTR, %INRs in range, SDINRs, left ventricular ejection fraction, CHA2DS2VASc, and the combination of CHA2DS2VASc + SDINRs (cutoff >1 and >.79, respectively). INR variability is an extremely useful tool to assess anticoagulation quality. Calculation of both

  19. Disturbance, Scale, and Boundary in Wilderness Management

    Treesearch

    Peter S. White; Jonathan Harrod; Joan L. Walker; Anke Jentsch

    2000-01-01

    Natural disturbances are critical to wilderness management. This paper reviews recent research on natural disturbance and addresses the problem of managing for disturbances in a world of human-imposed scales and boundaries. The dominant scale issue in disturbance management is the question of patch dynamic equilibrium. The dominant boundary issue in disturbance...

  20. Disturbance, scale, and boundary in wilderness management

    Treesearch

    Peter S. White; Jonathan Harrod; Joan L. Walker; Anke Jentsch

    2000-01-01

    Natural disturbances are critical to wilderness management. This paper reviews recent research on natural disturbance and addresses the problem of managing for disturbances in a world of human-imposed scales and boundaries. The dominant scale issue in disturbance management is the question of patch dynamic equilibrium. The dominant boundary issue in disturbance...

  1. SU-C-304-05: Use of Local Noise Power Spectrum and Wavelets in Comprehensive EPID Quality Assurance

    SciTech Connect

    Lee, S; Gopal, A; Yan, G; Bassett, P; Park, C; Samant, S

    2015-06-15

    Purpose: As EPIDs are increasingly used for IMRT QA and real-time treatment verification, comprehensive quality assurance (QA) of EPIDs becomes critical. Current QA with phantoms such as the Las Vegas and PIPSpro™ can fail in the early detection of EPID artifacts. Beyond image quality assessment, we propose a quantitative methodology using local noise power spectrum (NPS) to characterize image noise and wavelet transform to identify bad pixels and inter-subpanel flat-fielding artifacts. Methods: A total of 93 image sets including bar-pattern images and open exposure images were collected from four iViewGT a-Si EPID systems over three years. Quantitative metrics such as modulation transform function (MTF), NPS and detective quantum efficiency (DQE) were computed for each image set. Local 2D NPS was calculated for each subpanel. A 1D NPS was obtained by radial averaging the 2D NPS and fitted to a power-law function. R-square and slope of the linear regression analysis were used for panel performance assessment. Haar wavelet transformation was employed to identify pixel defects and non-uniform gain correction across subpanels. Results: Overall image quality was assessed with DQE based on empirically derived area under curve (AUC) thresholds. Using linear regression analysis of 1D NPS, panels with acceptable flat fielding were indicated by r-square between 0.8 and 1, and slopes of −0.4 to −0.7. However, for panels requiring flat fielding recalibration, r-square values less than 0.8 and slopes from +0.2 to −0.4 were observed. The wavelet transform successfully identified pixel defects and inter-subpanel flat fielding artifacts. Standard QA with the Las Vegas and PIPSpro phantoms failed to detect these artifacts. Conclusion: The proposed QA methodology is promising for the early detection of imaging and dosimetric artifacts of EPIDs. Local NPS can accurately characterize the noise level within each subpanel, while the wavelet transforms can detect bad pixels and

  2. Modeling Overland Erosion on Disturbed Rangeland

    NASA Astrophysics Data System (ADS)

    Al-Hamdan, O. Z.; Hernandez, M.; Pierson, F. B.; Nearing, M.; Stone, J. J.; Williams, C. J.; Boll, J.; Weltz, M.

    2012-12-01

    The Rangeland Hydrology and Erosion Model (RHEM) is a new process-based model developed by the USDA-ARS primarily for undisturbed rangeland. Greater sediment detachment rates are usually generated by concentrated flow rather than by sheet flow. Disturbance on rangeland such as fire and tree encroachment can increase overland flow erosion rate by increasing the likelihood of concentrated flow formation on a more erodible surface. In this study, we made advancement to RHEM by developing a new version of the model to predict concentrated flow erosion rate from disturbed rangelands. The model was conceptualized based on observations and results of experimental studies on rangelands disturbed by fire and/or by tree encroachment. A logistic equation was used to partition overland flow into concentrated flow and sheet flow. The equation predicts the probability of overland flow to become concentrated based on slope angle, percentage bare soil, and flow discharge per unit width. Sediment detachment rate from concentrated flow was calculated using soil erodibility of the site and hydraulic parameters of the flow such as flow width and stream power. Soil detachment was assumed to start when concentrated flow starts (i.e. no threshold concept for initiating detachment was used). Width of concentrated flow was determined by flow discharge and slope using an equation which was developed specifically for rangeland. A dynamic erodibility concept was used where concentrated flow erodibility was set to be high at the beginning of the event and then decrease exponentially due to the reduction of availability of disturbance-source-sediment. Initial erodibility was estimated using an empirical parameterization equation as a function of readily available vegetation cover and surface soil texture data. Detachment rate from rain splash and sheet flow was determined by rainfall intensity and sheet flow discharge. A dynamic partial differential sediment continuity equation was used to

  3. Melatonin, sleep disturbance and cancer risk.

    PubMed

    Blask, David E

    2009-08-01

    The pineal hormone melatonin is involved in the circadian regulation and facilitation of sleep, the inhibition of cancer development and growth, and the enhancement of immune function. Individuals, such as night shift workers, who are exposed to light at night on a regular basis experience biological rhythm (i.e., circadian) disruption including circadian phase shifts, nocturnal melatonin suppression, and sleep disturbances. Additionally, these individuals are not only immune suppressed, but they are also at an increased risk of developing a number of different types of cancer. There is a reciprocal interaction and regulation between sleep and the immune system quite independent of melatonin. Sleep disturbances can lead to immune suppression and a shift to the predominance in cancer-stimulatory cytokines. Some studies suggest that a shortened duration of nocturnal sleep is associated with a higher risk of breast cancer development. The relative individual contributions of sleep disturbance, circadian disruption due to light at night exposure, and related impairments of melatonin production and immune function to the initiation and promotion of cancer in high-risk individuals such as night shift workers are unknown. The mutual reinforcement of interacting circadian rhythms of melatonin production, the sleep/wake cycle and immune function may indicate a new role for undisturbed, high quality sleep, and perhaps even more importantly, uninterrupted darkness, as a previously unappreciated endogenous mechanism of cancer prevention.

  4. Evaluating Sleep Disturbance: A Review of Methods

    NASA Technical Reports Server (NTRS)

    Smith, Roy M.; Oyung, R.; Gregory, K.; Miller, D.; Rosekind, M.; Rosekind, Mark R. (Technical Monitor)

    1996-01-01

    There are three general approaches to evaluating sleep disturbance in regards to noise: subjective, behavioral, and physiological. Subjective methods range from standardized questionnaires and scales to self-report measures designed for specific research questions. There are two behavioral methods that provide useful sleep disturbance data. One behavioral method is actigraphy, a motion detector that provides an empirical estimate of sleep quantity and quality. An actigraph, worn on the non-dominant wrist, provides a 24-hr estimate of the rest/activity cycle. The other method involves a behavioral response, either to a specific probe or stimuli or subject initiated (e.g., indicating wakefulness). The classic, gold standard for evaluating sleep disturbance is continuous physiological monitoring of brain, eye, and muscle activity. This allows detailed distinctions of the states and stages of sleep, awakenings, and sleep continuity. Physiological delta can be obtained in controlled laboratory settings and in natural environments. Current ambulatory physiological recording equipment allows evaluation in home and work settings. These approaches will be described and the relative strengths and limitations of each method will be discussed.

  5. Evaluating Sleep Disturbance: A Review of Methods

    NASA Technical Reports Server (NTRS)

    Smith, Roy M.; Oyung, R.; Gregory, K.; Miller, D.; Rosekind, M.; Rosekind, Mark R. (Technical Monitor)

    1996-01-01

    There are three general approaches to evaluating sleep disturbance in regards to noise: subjective, behavioral, and physiological. Subjective methods range from standardized questionnaires and scales to self-report measures designed for specific research questions. There are two behavioral methods that provide useful sleep disturbance data. One behavioral method is actigraphy, a motion detector that provides an empirical estimate of sleep quantity and quality. An actigraph, worn on the non-dominant wrist, provides a 24-hr estimate of the rest/activity cycle. The other method involves a behavioral response, either to a specific probe or stimuli or subject initiated (e.g., indicating wakefulness). The classic, gold standard for evaluating sleep disturbance is continuous physiological monitoring of brain, eye, and muscle activity. This allows detailed distinctions of the states and stages of sleep, awakenings, and sleep continuity. Physiological delta can be obtained in controlled laboratory settings and in natural environments. Current ambulatory physiological recording equipment allows evaluation in home and work settings. These approaches will be described and the relative strengths and limitations of each method will be discussed.

  6. Sleep disturbance in older ICU patients

    PubMed Central

    Sterniczuk, Roxanne; Rusak, Benjamin; Rockwood, Kenneth

    2014-01-01

    Maintaining a stable and adequate sleeping pattern is associated with good health and disease prevention. As a restorative process, sleep is important for supporting immune function and aiding the body in healing and recovery. Aging is associated with characteristic changes to sleep quantity and quality, which make it more difficult to adjust sleep–wake rhythms to changing environmental conditions. Sleep disturbance and abnormal sleep–wake cycles are commonly reported in seriously ill older patients in the intensive care unit (ICU). A combination of intrinsic and extrinsic factors appears to contribute to these disruptions. Little is known regarding the effect that sleep disturbance has on health status in the oldest of old (80+), a group, who with diminishing physiological reserve and increasing prevalence of frailty, is at a greater risk of adverse health outcomes, such as cognitive decline and mortality. Here we review how sleep is altered in the ICU, with particular attention to older patients, especially those aged ≥80 years. Further work is required to understand what impact sleep disturbance has on frailty levels and poor outcomes in older critically ill patients. PMID:25018625

  7. On the centrality of disturbance rejection in automatic control.

    PubMed

    Gao, Zhiqiang

    2014-07-01

    In this paper, it is shown that the problem of automatic control is, in essence, that of disturbance rejection, with the notion of disturbance generalized to symbolize the uncertainties, both internal and external to the plant. A novel, unifying concept of disturbance rejector is proposed to compliment the traditional notion of controller. The new controller-rejector pair is shown to be a powerful organizing principle in the realm of automatic control, leading to a Copernican moment where the model-centric design philosophy is replaced by the one that is control-centric in the following sense: the controller is designed for a canonical model and is fixed; the difference between the plant and the canonical model is deemed as disturbance and rejected.

  8. Stream Succession: Channel Changes After Wildfire Disturbance

    NASA Astrophysics Data System (ADS)

    Scheidt, N. E.; Luce, C. H.; Buffington, J. M.; Rieman, B.; Black, T.

    2004-12-01

    One paradigm in geomorphology is that vegetation is a fundamental control on sediment and water supplies to streams, and therefore on downstream geomorphology. Within this paradigm, wildfire has been implicated as a major driving force behind landscape erosion and changes to stream channels, periodically yielding pulses of sediment from upland basins, which, in turn, hypothetically, drive cyclical changes to stream channels. Within the context of management for ecologically valuable aquatic species across a landscape, biologists have envisioned available stream habitats cycling on long time scales, with some habitats increasing or decreasing in productivity, while others are temporarily taken out of production by severe disturbances related to fire. Some hypothesize that stream habitats may benefit from disturbance after the initial reorganization, increasing in quality over time, until the disturbance-supplied materials, gravel and wood, eventually become scarce, reducing habitat quality until the next disturbance. Systematic observations of actual channel "succession", however, are rare. We examined the long-term effects of wildfire disturbance on channel characteristics in moderate-gradient (2.3-3.9%), unconfined, mountain streams. Selection of this stream type excludes direct impacts from post-fire debris flows and allows us to focus on post-fire changes in basin hydrology, sediment supply and proximal riparian characteristics (supply of wood debris, bank strength from roots, etc.). The study was designed using a space-for-time substitution within the Idaho batholith. We considered three different forest age classes, corresponding with three different times since fire: recent (15-20 yrs), mid (90-130 yrs), and old (>150 yrs). Variables independent of fire and with potentially confounding effects (elevation, drainage area, land use, lithology, valley slope) were controlled to isolate the effect of fire on channel characteristics. Characteristics of interest

  9. Assesing Ecohydrological Impacts of Forest Disturbance using Open Source Software

    NASA Astrophysics Data System (ADS)

    Lovette, J. P.; Chang, T.; Treglia, M.; Gan, T.; Duncan, J.

    2014-12-01

    In the past 30 years, land management protocols, climate change, and land use have radically changed the frequency and magnitudes of disturbance regimes. Landscape scale disturbances can change a forest structure, resulting in impacts on adjacent watersheds that may affect water amount/quality for human and natural resource use. Our project quantifies hydrologic changes from of a suite of disturbance events resulting in vegetation cover shifts at watersheds across the continental United States. These disturbance events include: wildfire, insect/disease, deforestation(logging), hurricanes, ice storms, and human land use. Our major question is: Can the effects of disturbance on ecohydrology be generalized across regions, time scales, and spatial scales? Using a workflow of open source tools, and utilizing publicly available data, this work could be extended and leveraged by other researchers. Spatial data on disturbance include the MODIS Global Disturbance Index (NTSG), Landsat 7 Global Forest Change (Hansen dataset), and the Degree of Human Modification (Theobald dataset). Ecohydrologic response data includes USGS NWIS, USFS-LTER climDB/hydroDB, and the CUAHSI HIS.

  10. Purpose in life and incidence of sleep disturbances.

    PubMed

    Kim, Eric S; Hershner, Shelley D; Strecher, Victor J

    2015-06-01

    Purpose in life has been linked with better mental health, physical health, and health behaviors, but the association between purpose and sleep is understudied. Sleep disturbances increase with age and as the number of older adults rapidly increases, it is ever more important to identify modifiable factors that are associated with reduced incidence of sleep disturbances. We used multiple logistic regression models and data from the Health and Retirement Study, a nationally representative panel study of American adults over the age of 50, to examine whether higher purpose was linked with a reduced incidence of sleep disturbances. Among 4144 respondents reporting minimal or no sleep disturbances at baseline, higher purpose was associated with a lower incidence of sleep disturbances over the 4-year follow-up. After adjusting for sociodemographic factors, each unit increase in purpose (on a six-point scale) was associated with a 16 % reduced odds of developing sleep disturbances (OR 0.84, 95 % CI 0.77-0.92). The association between purpose and sleep disturbances remained after adjusting for sociodemographic, behavioral, psychological, and health covariates. Should future research replicate our findings, this area of research may lead to innovative efforts that improve the quality of sleep in older adults.

  11. Soil properties discriminating Araucaria forests with different disturbance levels.

    PubMed

    Bertini, Simone Cristina Braga; Azevedo, Lucas Carvalho Basilio; Stromberger, Mary E; Cardoso, Elke Jurandy Bran Nogueira

    2015-04-01

    Soil biological, chemical, and physical properties can be important for monitoring soil quality under one of the most spectacular vegetation formation on Atlantic Forest Biome, the Araucaria Forest. Our aim was to identify a set of soil variables capable of discriminating between disturbed, reforested, and native Araucaria forest soils such that these variables could be used to monitor forest recovery and maintenance. Soil samples were collected at dry and rainy season under the three forest types in two state parks at São Paulo State, Brazil. Soil biological, chemical, and physical properties were evaluated to verify their potential to differentiate the forest types, and discriminant analysis was performed to identify the variables that most contribute to the differentiation. Most of physical and chemical variables were sensitive to forest disturbance level, but few biological variables were significantly different when comparing native, reforested, and disturbed forests. Despite more than 20 years following reforestation, the reforested soils were chemically and biologically distinct from native and disturbed forest soils, mainly because of the greater acidity and Al3+ content of reforested soil. Disturbed soils, in contrast, were coarser in texture and contained greater concentrations of extractable P. Although biological properties are generally highly sensitive to disturbance and amelioration efforts, the most important soil variables to discriminate forest types in both seasons included Al3+, Mg2+, P, and sand, and only one microbial attribute: the NO2- oxidizers. Therefore, these five variables were the best candidates, of the variables we employed, for monitoring Araucaria forest disturbance and recovery.

  12. Application of a karst disturbance index in Hillsborough County, Florida.

    PubMed

    van Beynen, Philip; Feliciano, Nilda; North, Leslie; Townsend, Kaya

    2007-02-01

    Hillsborough County, Florida, is a karst region that is heavily urbanized, yet no study has been undertaken measuring the degree of human disturbance. Van Beynen and Townsend (2005) created a hierarchical and standardized disturbance index specifically designed for karst environments. To address the problem of determining human disturbance in the county, the above index was successfully applied and it was found that Hillsborough was highly disturbed (disturbance score of 0.69 of 1.0) because of its predominant urban and rural land use. Furthermore, the application of the index allowed for its refinement and the highlighting of environmental aspects in need of remediation such as soil compaction, deforestation, disturbance of archaeological sites, and the expanding urban footprint. Several minor issues arose during the application: the need for broader indicator descriptions that encompass a variety of scenarios, the need for a revised water quality indicator, inadequate data on sinkholes, and a lack of data for species richness and species population density. The utility of the index to resource managers arises from emphasizing certain areas of the environment that require immediate attention and determining temporal changes in environmental quality. Future application of the index requires potential retooling of the biota indicators, tightening of scoring descriptions for certain indicators, and further examination of the scale at which the index can be applied.

  13. Disturbance Distance: Combining a process based ecosystem model and remote sensing data to map the vulnerability of U.S. forested ecosystems to potentially altered disturbance rates

    NASA Astrophysics Data System (ADS)

    Dolan, K. A.

    2015-12-01

    Disturbance plays a critical role in shaping the structure and function of forested ecosystems as well as the ecosystem services they provide, including but not limited to: carbon storage, biodiversity habitat, water quality and flow, and land atmosphere exchanges of energy and water. In addition, recent studies suggest that disturbance rates may increase in the future under altered climate and land use scenarios. Thus understanding how vulnerable forested ecosystems are to potential changes in disturbance rates is of high importance. This study calculated the theoretical threshold rate of disturbance for which forest ecosystems could no longer be sustained (λ*) across the Coterminous U.S. using an advanced process based ecosystem model (ED). Published rates of disturbance (λ) in 50 study sites were obtained from the North American Forest Disturbance (NAFD) program. Disturbance distance (λ* - λ) was calculated for each site by differencing the model based threshold under current climate conditions and average observed rates of disturbance over the last quarter century. Preliminary results confirm all sample forest sites have current average rates of disturbance below λ*, but there were interesting patterns in the recorded disturbance distances. In general western sites had much smaller disturbance distances, suggesting higher vulnerability to change, while eastern sites showed larger buffers. Ongoing work is being conducted to assess the vulnerability of these sites in the context of potential future changes by propagating scenarios of future climate and land-use change through the analysis.

  14. A fast algorithm for automatic detection of ionospheric disturbances: DROT

    NASA Astrophysics Data System (ADS)

    Efendi, Emre; Arikan, Feza

    2017-06-01

    Solar, geomagnetic, gravitational and seismic activities cause disturbances in the ionospheric region of upper atmosphere that may disrupt or lower the quality of space based communication, navigation and positioning system signals. These disturbances can be categorized with respect to their amplitude, duration and frequency. Typically in the literature, ionospheric disturbances are investigated with gradient based methods on Total Electron Content (TEC) data estimated from ground based dual frequency Global Positioning System (GPS) receivers. In this study, a fast algorithm is developed for the automatic detection of the variability in Slant TEC (STEC) data. STEC is defined as the total number of electrons on the ray path between the ground based receiver and GPS satellite in the orbital height of 20,000 km. The developed method, namely, Differential Rate of TEC (DROT), is based on Rate of Tec (ROT) method. ROT is widely used in the literature and it is usually applied to Vertical TEC (VTEC) that corresponds to the projection of STEC to the vertical direction along the ray path at the Ionospheric Pierce Point (IPP) using a mapping function. The developed DROT method can be defined as the normalized metric norm between the ROT and its baseband trend structure. In this study, the performance of DROT is determined using synthetic data with variable bounds on the parameter set of amplitude, frequency and duration of disturbance. It is observed that DROT method can detect disturbances in three categories. For DROT values less than 50%, there is no significant disturbance in STEC data. For DROT values between 50% and 70%, a medium scale disturbance can be observed. For DROT values over 70%, severe disturbances such as Large Scale Traveling Ionospheric Disturbances (LSTIDs) can be observed. DROT method is highly sensitive to the amplitude of the wave-like oscillations. For a disturbance amplitude as low as 1.01 TECU, the disturbances that have durations longer than or

  15. Disturbance regime and disturbance interactions in Rocky Mountain subalpine forest

    USGS Publications Warehouse

    Veblen, Thomas T.; Hadley, Keith S.; Nel, Elizabeth M.; Kitzberger, Thomas; Reid, Marion; Villalba, Ricardo

    1994-01-01

    1 The spatial and temporal patterns of fire, snow avalanches and spruce beetle out-breaks were investigated in Marvine Lakes Valley in the Colorado Rocky Mountains in forests of Picea engelmannii, Abies lasiocarpa, Pseudotsuga menziesiiand Populus tremuloides. Dates and locations of disturbances were determined by dendrochronological techniques. A geographic information system (GIS) was used to calculate areas affected by the different disturbance agents and to examine the spatial relationships of the different disturbances. 2 In the Marvine Lakes Valley, major disturbance was caused by fire in the 1470s, the 1630s and the 1870s and by spruce beetle outbreak in c. 1716, 1827 and 1949. 3 Since c. 1633, 9% of the Marvine Lakes Valley has been affected by snow avalanches, 38.6% by spruce beetle outbreak and 59.1% by fire. At sites susceptible to avalanches, avalanches occur at a near-annual frequency. The mean return intervals for fire and spruce beetle outbreaks are 202 and 116.5 years, respectively. Turnover times for fire and spruce beetle outbreaks are 521 and 259 years, respectively. 4 Several types of disturbance interaction were identified. For example, large and severe snow avalanches influence the spread of fire. Similarly, following a stand-devastating fire or avalanche, Picea populations will not support a spruce beetle outbreak until individual trees reach a minimum diameter which represents at least 70 years' growth. Thus, recent fires and beetle outbreaks have nonoverlapping distributions.

  16. 240 W high-average-power square-shaped nanosecond all-fiber-integrated laser with near diffraction-limited beam quality.

    PubMed

    Yu, Hailong; Tao, Rumao; Wang, Xiaolin; Zhou, Pu; Chen, Jinbao

    2014-10-01

    We report an all-fiber-integrated high-average-power square-shaped nanosecond pulse laser operating at 1068 nm based on the master oscillator power amplifier configuration. The seed source is a passively mode-locked Yb-doped fiber laser with fundamental cavity repetition rate of 1.86 MHz. Output pulses with a square shape can be tuned in pulse width from 271 ps to the nanosecond level. The average output power reaches to 9.21 W after three preamplifiers. Finally, a main amplifier is developed to boost the average output power to 240 W, and the corresponding pulse energy and peak power are ∼ 129.3 μJ and 36 kW, respectively. The efficiency of the main amplifier is ∼ 61.3%, and the beam quality represented by M(2) factors is below 1.3 and 1.2 in the X and Y directions.

  17. [Non-Pharmacological Interventions for Pregnancy-Related Sleep Disturbances].

    PubMed

    Hung, Hsuan-Man; Chiang, Hsiao-Ching

    2017-02-01

    Most women experience the worse sleep quality of their life during pregnancy and the early postpartum period. Although pregnancy typically accounts for a relatively short part of a woman's life, the related sleep disturbances may have a significant and negative impact on her long-term health. Approximately 78-80% of pregnant women experience sleep disturbances, including interruptions in deep sleep, decreased total sleep time, poor subjective sleep quality, frequent night waking, and reduced sleep efficacy. Sleep disturbances during pregnancy start during the first trimester and become prevalent during the third trimester. Related factors include physiological and psychosocial changes and an unhealthy lifestyle. As non-pharmacological interventions have the potential to improve sleep quality in 70% to 80% of patients with insomnia, this is the main approached that is currently used to treat pregnancy-related sleep disturbances. Examples of these non-pharmacological interventions include music therapy, aerobic exercise, massage, progressive muscle relaxation, multi-modal interventions, and the use of a maternity support belt. The efficacy and safety of other related non-pharmacological interventions such as auricular acupressure, cognitive therapy, tai chi, and aromatherapy remain uncertain, with more empirical research required. Additionally, non-pharmacological interventions do not effectively treat sleep disturbances in all pregnant women.

  18. Biweekly disturbance capture and attribution: case study in western Alberta grizzly bear habitat

    NASA Astrophysics Data System (ADS)

    Hilker, Thomas; Coops, Nicholas C.; Gaulton, Rachel; Wulder, Michael A.; Cranston, Jerome; Stenhouse, Gordon

    2011-01-01

    An increasing number of studies have demonstrated the impact of landscape disturbance on ecosystems. Satellite remote sensing can be used for mapping disturbances, and fusion techniques of sensors with complimentary characteristics can help to improve the spatial and temporal resolution of satellite-based mapping techniques. Classification of different disturbance types from satellite observations is difficult, yet important, especially in an ecological context as different disturbance types might have different impacts on vegetation recovery, wildlife habitats, and food resources. We demonstrate a possible approach for classifying common disturbance types by means of their spatial characteristics. First, landscape level change is characterized on a near biweekly basis through application of a data fusion model (spatial temporal adaptive algorithm for mapping reflectance change) and a number of spatial and temporal characteristics of the predicted disturbance patches are inferred. A regression tree approach is then used to classify disturbance events. Our results show that spatial and temporal disturbance characteristics can be used to classify disturbance events with an overall accuracy of 86% of the disturbed area observed. The date of disturbance was identified as the most powerful predictor of the disturbance type, together with the patch core area, patch size, and contiguity.

  19. Conversion of Low Quality Waste Heat to Electric Power with Small-Scale Organic Rankine Cycle (ORC) Engine/Generator Technology

    DTIC Science & Technology

    2016-06-01

    FINAL REPORT Conversion of Low Quality Waste Heat to Electric Power with Small-Scale Organic Rankine Cycle (ORC) Engine/Generator...Economics: Total System Benefit - ORC Electric Output plus Cooling Load Reduction (45 kW...MWh Megawatt hours NEC National Electric Code NESHAP National Emissions Standard for Hazardous Air Pollutants v Acronym Definition NFPA

  20. Power distance and mentor-protégé relationship quality as moderators of the relationship between informal mentoring and burnout: evidence from China.

    PubMed

    Qian, Jing; Han, Zhuo; Wang, Haiwan; Li, Xiaoyan; Wang, Qiuyue

    2014-01-01

    The topic of how to prevent and reduce burnout has drawn great attention from researchers and practitioners in recent years. However, we know little about how mentoring as a form of social support exerts influence on employee burnout. This study aims to examine the contingency side of the mentoring-burnout relationship by addressing the exploratory question of whether individual differences in power distance and relationship quality play important roles in mentoring effectiveness in terms of reducing a protégé's burnout level. A total of 210 employees from a technology communications company completed the survey questionnaire. (1) A protégés' power distance moderates the negative relationship between mentoring and burnout in such a way that the relationship is stronger for protégés who are lower rather than higher in power distance; (2) mentor-protégé relationship quality moderates the negative relationship between mentoring and burnout in such a way that the relationship is stronger when the relationship quality is higher rather than lower. In sum, our results highlight the importance of studying the contingency side of mentoring effects on protégé burnout. Our findings suggest that the individuals' different cultural values of power distance and mentor-protégé relationship quality are the boundary conditions for the mentoring-burnout relationship. We therefore suggest that research on mentoring-burnout will be advanced by considering the role of the moderating process.

  1. Toward a Critical Theory Approach to Lives Considered Emotionally Disturbed.

    ERIC Educational Resources Information Center

    Danforth, Scot

    1995-01-01

    This article addresses issues of power residing within various special education processes that result in processes of hegemony and domination in the lives of children considered to have emotional disturbances. A critical theory approach is proposed which is explicitly political and stresses the need to value the child's personal history and…

  2. Convergent structural responses of tropical forests to diverse disturbance regimes.

    PubMed

    Kellner, James R; Asner, Gregory P

    2009-09-01

    Size frequency distributions of canopy gaps are a hallmark of forest dynamics. But it remains unknown whether legacies of forest disturbance are influencing vertical size structure of landscapes, or space-filling in the canopy volume. We used data from LiDAR remote sensing to quantify distributions of canopy height and sizes of 434,501 canopy gaps in five tropical rain forest landscapes in Costa Rica and Hawaii. The sites represented a wide range of variation in structure and natural disturbance history, from canopy gap dynamics in lowland Costa Rica and Hawaii, to stages and types of stand-level dieback on upland Mauna Kea and Kohala volcanoes. Large differences in vertical canopy structure characterized these five tropical rain forest landscapes, some of which were related to known disturbance events. Although there were quantitative differences in the values of scaling exponents within and among sites, size frequency distributions of canopy gaps followed power laws at all sites and in all canopy height classes. Scaling relationships in gap size at different heights in the canopy were qualitatively similar at all sites, revealing a remarkable similarity despite clearly defined differences in species composition and modes of prevailing disturbance. These findings indicate that power-law gap-size frequency distributions are ubiquitous features of these five tropical rain forest landscapes, and suggest that mechanisms of forest disturbance may be secondary to other processes in determining vertical and horizontal size structure in canopies.

  3. A Disturbed Galactic Duo

    NASA Astrophysics Data System (ADS)

    2011-04-01

    variety, classified as a Type Ia, is thought to occur when a dense, hot star called a white dwarf - a remnant of medium-sized stars like our Sun - gravitationally sucks gas away from a nearby companion star. This added fuel eventually causes the whole star to explode in a runaway fusion reaction. The new image presented here of a remarkable galactic dynamic duo is based on data selected by Igor Chekalin for ESO's Hidden Treasures 2010 astrophotography competition. Chekalin won the first overall prize and this image received the second highest ranking of the nearly 100 contest entries [2]. Notes [1] Other much more noticeable points of light, such as the one toward the left end of the spiral arm running underneath of NGC 3169's core, are stars within the Milky Way that happen to fall by chance very close to the line of sight between our telescopes and the galaxies. [2] ESO's Hidden Treasures 2010 competition gave amateur astronomers the opportunity to search through ESO's vast archives of astronomical data, hoping to find a well-hidden gem that needed polishing by the entrants. To find out more about Hidden Treasures, visit http://www.eso.org/public/outreach/hiddentreasures/. More information ESO, the European Southern Observatory, is the foremost intergovernmental astronomy organisation in Europe and the world's most productive astronomical observatory. It is supported by 15 countries: Austria, Belgium, Brazil, the Czech Republic, Denmark, France, Finland, Germany, Italy, the Netherlands, Portugal, Spain, Sweden, Switzerland and the United Kingdom. ESO carries out an ambitious programme focused on the design, construction and operation of powerful ground-based observing facilities enabling astronomers to make important scientific discoveries. ESO also plays a leading role in promoting and organising cooperation in astronomical research. ESO operates three unique world-class observing sites in Chile: La Silla, Paranal and Chajnantor. At Paranal, ESO operates the Very Large

  4. Frequency response of slot coating flow to gap disturbances

    NASA Astrophysics Data System (ADS)

    Lee, Semi; Nam, Jaewook

    2016-03-01

    Slot coating is a common method of manufacturing films such as optical films, adhesive tapes, etc. It is a pre-metered method: the final wet film thickness is set by the flow rate and the web speed, and independent of other operating parameters and coating liquid properties. Therefore, it is ideal for precise film thickness control. To produce uniform film, the coating flow needs to be steady-state, two-dimensional, and stable. In the slot coating process, however, there are always some small-scale disturbances generated by rotating process units, such as pumps, rolls, etc., and they usually have periodicity. These disturbances cause a non-uniformity of the moving web direction and could spoil the film quality. Therefore, the sensitivity analysis of coating flow under the periodic disturbances is important. Among all disturbances, a change of coating gap, i.e. the distance between the die lip and the moving substrate, is known to the most dangerous disturbance. This type of disturbance is usually called the gap oscillation, and caused by the substrate thickness variations, mechanical vibration of the coating die or roll, and roll run outs. Here, we analyze the effect of fluid properties, operating conditions and die configurations on response of slot coating flow to gap disturbances. In this study, we use Galerkin/finite element method to solve transient Navier-Stokes equation under periodic disturbance. We define the amplification factor as an indicator of film non-uniformity and analyze the effect of different parameters by comparing the factor. In particular, we use Carreau-Yasuda model to describe shear-thinning property of xanthan gum solution and compare with Newtonian fluid.

  5. Development of Quality Assessment Techniques for Large Eddy Simulation of Propulsion and Power Systems in Complex Geometries

    SciTech Connect

    Lacaze, Guilhem; Oefelein, Joseph

    2015-03-01

    Large-eddy-simulation (LES) is quickly becoming a method of choice for studying complex thermo-physics in a wide range of propulsion and power systems. It provides a means to study coupled turbulent combustion and flow processes in parameter spaces that are unattainable using direct-numerical-simulation (DNS), with a degree of fidelity that can be far more accurate than conventional engineering methods such as the Reynolds-averaged Navier-Stokes (RANS) approx- imation. However, development of predictive LES is complicated by the complex interdependence of different type of errors coming from numerical methods, algorithms, models and boundary con- ditions. On the other hand, control of accuracy has become a critical aspect in the development of predictive LES for design. The objective of this project is to create a framework of metrics aimed at quantifying the quality and accuracy of state-of-the-art LES in a manner that addresses the myriad of competing interdependencies. In a typical simulation cycle, only 20% of the computational time is actually usable. The rest is spent in case preparation, assessment, and validation, because of the lack of guidelines. This work increases confidence in the accuracy of a given solution while min- imizing the time obtaining the solution. The approach facilitates control of the tradeoffs between cost, accuracy, and uncertainties as a function of fidelity and methods employed. The analysis is coupled with advanced Uncertainty Quantification techniques employed to estimate confidence in model predictions and calibrate model's parameters. This work has provided positive conse- quences on the accuracy of the results delivered by LES and will soon have a broad impact on research supported both by the DOE and elsewhere.

  6. Preliminary study of AC power feeders for AGS booster

    SciTech Connect

    Meth, M.

    1992-07-17

    It has been proposed that the AGS Heavy Ion/Proton Booster be excited directly from the electric power distribution system without intervening an energy storage buffer such as an MG set or a magnetic energy buffer. The average power requirement of the AGS Booster is less than many single-loads presently housed on the lab site. However, the power swing will be the largest single pulsating load on the lab site. The large power swings will impact on the power grid producing utility-line disturbances such as voltage fluctuations and harmonic generation. Thus, it is necessary to carefully evaluate the quality of the electric power system resulting from the interconnection, such that the utility system is not degraded either on the lab site or at LILCO's substation.

  7. Preliminary study of AC power feeders for AGS booster

    SciTech Connect

    Meth, M.

    1992-07-17

    It has been proposed that the AGS Heavy Ion/Proton Booster be excited directly from the electric power distribution system without intervening an energy storage buffer such as an MG set or a magnetic energy buffer. The average power requirement of the AGS Booster is less than many single-loads presently housed on the lab site. However, the power swing will be the largest single pulsating load on the lab site. The large power swings will impact on the power grid producing utility-line disturbances such as voltage fluctuations and harmonic generation. Thus, it is necessary to carefully evaluate the quality of the electric power system resulting from the interconnection, such that the utility system is not degraded either on the lab site or at LILCO`s substation.

  8. State Definitions of Emotional Disturbance

    ERIC Educational Resources Information Center

    Wery, Jessica J.; Cullinan, Douglas

    2013-01-01

    This article examines definitions state education agencies use to describe the federal education disability called "emotional disturbance." State definitions were collected so that various aspects of them could be analyzed and compared with results of similar studies completed in the 1970s and 1980s. Among results are that state definitions have…

  9. Disturbed by Meta-Analysis?

    ERIC Educational Resources Information Center

    Wachter, Kenneth W.

    1988-01-01

    Defines meta-analysis as statistical procedures for combining results from previous separate studies. Discusses four charges promoted by some skeptics as it relates to this statistical procedure. States that many of the trends making a place for meta-analysis are disturbing. (RT)

  10. Soil-disturbance field guide

    Treesearch

    Carolyn Napper; Steven Howes; Deborah Page-Dumroese

    2009-01-01

    The San Dimas Technology and Development Center of the Forest Service, U. S. Department of Agriculture, developed the soil-disturbance field guide as a soil monitoring tool to identify soildisturbance classes. The field guide provides detailed descriptions and photographic examples - over a wide range of climatic and vegetative conditions - of the undisturbed soil...

  11. State Definitions of Emotional Disturbance

    ERIC Educational Resources Information Center

    Wery, Jessica J.; Cullinan, Douglas

    2013-01-01

    This article examines definitions state education agencies use to describe the federal education disability called "emotional disturbance." State definitions were collected so that various aspects of them could be analyzed and compared with results of similar studies completed in the 1970s and 1980s. Among results are that state definitions have…

  12. RESILIENCE OF ECOSYSTEMS TO DISTURBANCES

    EPA Science Inventory

    Resilience, in an ecological context, is one of several terms that characterize the response of an ecosystem to disturbance. Other such terms include persistence, resistance and stability. Two definitions of resilience have become prominent in the literature, both of which derive...

  13. Disturbance processes and ecosystem management

    Treesearch

    Robert D. Averill; Louise Larson; Jim Saveland; Philip Wargo; Jerry Williams; Melvin Bellinger

    1994-01-01

    This paper is intended to broaden awareness and help develop consensus among USDA Forest Service scientists and resource managers about the role and significance of disturbance in ecosystem dynamics and, hence, resource management. To have an effective ecosystem management policy, resource managers and the public must understand the nature of ecological resiliency and...

  14. Comparison Between Family Power Structure and the Quality of Parent-Child Interaction Among the Delinquent and Non-Delinquent Adolescents

    PubMed Central

    Khodabakhshi Koolaee, Anahita; Shaghelani Lor, Hossein; Soleimani, Ali Akbar; Rahmatizadeh, Masoumeh

    2014-01-01

    Background: Few studies indicate that most behavioral problems are due to family dysfunction and inappropriate family environment. It seems that the family of the delinquent adolescent is unbalanced in the power structure and parenting style. Objectives: The present study compares the family power structure and parent-child relationship quality in delinquent and non-delinquent young subjects in Tehran. Patients and Methods: Eighty students of secondary schools aged between 15 and 18 in Tehran were enrolled with cluster sampling method and 80 delinquent adolescents of the Correction and Rehabilitation Centers aged between 15 and 18 were chosen with a convenience sampling method. They responded to an instrument of family power structure (Child–parents relationship inventory). Data was compared between these two groups by utilizing the independent and dependent t-test and Levene’s test. Results: The findings indicated there is a significant difference between delinquent and non-delinquent adolescents in family power structure and its subscales (P < 0.001) and father-child relationship quality (P < 0.005). Also, there is no statistically significant difference between these two groups in mother-child relationship quality (P < 0.005). Besides, the results revealed that delinquent adolescents were significantly different regarding the quality of parent-child relationship (P < 0.001). Conclusions: These results emphasize that an inappropriate decision making process pattern in a family has a significant effect on deviant behavior in adolescents. The fathers’ parenting is more strongly linked to their sons’ delinquency. So, family power structure and parent-child relationship can be considered in therapeutic interventions (prevention and treatment) for adolescents’ delinquency. PMID:25032158

  15. Simulations of far-field optical beam quality influenced by the thermal distortion of the secondary mirror for high-power laser system

    NASA Astrophysics Data System (ADS)

    Guo, Ruhai; Chen, Ning; Zhuang, Xinyu; Wang, Bing

    2015-02-01

    In order to research the influence on the beam quality due to thermal deformation of the secondary mirror in the high power laser system, the theoretical simulation study is performed. Firstly, three typical laser power 10kW, 50kW and 100kW with the wavelength 1.064μm are selected to analyze thermal deformation of mirror through the finite element analyze of thermodynamics instantaneous method. Then the wavefront aberration can be calculated by ray-tracing theory. Finally, focus spot radius,beam quality (BQ) of far-filed beam can be calculated and comparably analyzed by Fresnel diffraction integration. The simulation results show that with the increasing laser power, the optical aberration of beam director gets worse, the far-field optical beam quality decrease, which makes the laser focus spot broadening and the peak optical intensity of center decreasing dramatically. Comparing the clamping ring and the three-point clamping, the former is better than the latter because the former only induces the rotation symmetric deformation and the latter introduces additional astigmatism. The far-field optical beam quality can be improved partly by simply adjusting the distance between the main mirror and the secondary mirror. But the far-field power density is still the one tenth as that without the heat distortion of secondary mirror. These results can also provide the reference to the thermal aberration analyze for high power laser system and can be applied to the field of laser communication system and laser weapon etc.

  16. Anthropogenic disturbance reduces seed-dispersal services for myrmecochorous plants in the Brazilian Caatinga.

    PubMed

    Leal, Laura C; Andersen, Alan N; Leal, Inara R

    2014-01-01

    Anthropogenic disturbance can have important indirect effects on ecosystems by disrupting species interactions. Here we examine the effects of anthropogenic disturbance on distance dispersal by ants for the diaspores of myrmecochorous Euphorbiaceae in Brazilian Caatinga. Rates of diaspore removal and distances removed of Croton sonderianus and Jatropha mollissima were observed at 24 sites ranging from low to very high disturbance (primarily grazing by livestock, hunting and firewood collection). Despite a large number of seed-disperser ant species, there were only two species providing high-quality distance-dispersal services, Dinoponera quadriceps (40% of all observed seed removals) and Ectatomma muticum (33%). D. quadriceps was responsible for 97% of all removals >2 m, and 100% of all removals >5 m. Removal rates did not vary with disturbance for C. sonderianus (small elaiosome), but declined with increasing disturbance for J. mollissima (large elaiosome). The number of removals by Ectatomma was highest at intermediate levels of disturbance, whereas those by Dinoponera decreased systematically with increasing levels of disturbance. Mean dispersal distance was four times higher at sites experiencing low disturbance, where removals >5 m represented a third of all removal events, compared with very highly disturbed sites, where no removals >5 m were observed. Despite high overall diversity there is very limited functional redundancy in disperser ant species, resulting in low disperser resilience in relation to disturbance. This is likely to have important implications for recruitment by myrmecochorous plants, and therefore on vegetation composition and structure, at sites subject to high anthropogenic disturbance.

  17. Expanded Quality Management Using Information Power (EQUIP): protocol for a quasi-experimental study to improve maternal and newborn health in Tanzania and Uganda

    PubMed Central

    2014-01-01

    Background Maternal and newborn mortality remain unacceptably high in sub-Saharan Africa. Tanzania and Uganda are committed to reduce maternal and newborn mortality, but progress has been limited and many essential interventions are unavailable in primary and referral facilities. Quality management has the potential to overcome low implementation levels by assisting teams of health workers and others finding local solutions to problems in delivering quality care and the underutilization of health services by the community. Existing evidence of the effect of quality management on health worker performance in these contexts has important limitations, and the feasibility of expanding quality management to the community level is unknown. We aim to assess quality management at the district, facility, and community levels, supported by information from high-quality, continuous surveys, and report effects of the quality management intervention on the utilization and quality of services in Tanzania and Uganda. Methods In Uganda and Tanzania, the Expanded Quality Management Using Information Power (EQUIP) intervention is implemented in one intervention district and evaluated using a plausibility design with one non-randomly selected comparison district. The quality management approach is based on the collaborative model for improvement, in which groups of quality improvement teams test new implementation strategies (change ideas) and periodically meet to share results and identify the best strategies. The teams use locally-generated community and health facility data to monitor improvements. In addition, data from continuous health facility and household surveys are used to guide prioritization and decision making by quality improvement teams as well as for evaluation of the intervention. These data include input, process, output, coverage, implementation practice, and client satisfaction indicators in both intervention and comparison districts. Thus, intervention districts

  18. Intrapersonal self-transcendence, meaning-in-life and nurse-patient interaction: powerful assets for quality of life in cognitively intact nursing-home patients.

    PubMed

    Haugan, Gørill; Moksnes, Unni Karin; Løhre, Audhild

    2016-12-01

    Spirituality has demonstrated a significant impact on quality of life in nursing-home patients. Likewise, as essential aspects of spirituality, hope, self-transcendence, and meaning are found to be vital resources to nursing-home patients' global well-being. Further, nurse-patient interaction has demonstrated a powerful influence on patient's hope, self-transcendence, and meaning-in-life, as well as on anxiety and depression. The present study investigated the associations of hope, self-transcendence, meaning, and perceived nurse-patient interaction with quality of life. In a cross-sectional design, a sample of 202 cognitively intact nursing-home patients in Mid-Norway responded to the Herth Hope Index, the Self-Transcendence scale, the Purpose-in-Life test, the Nurse-Patient Interaction scale, and a one-item overall measure on quality of life. Using SPSS ordinal regression, bivariate and multivariate analyses were conducted with quality of life as dependent variable. Controlling for gender, age, and residential time, all the scales were significantly related to quality of life in the bivariate analyses. Intrapersonal self-transcendence showed an exceptional position presenting a very high odds ratio in the bivariate analysis, and also the strongest association with quality of life in multivariate analyses. Meaning and nurse-patient interaction also showed independent and significant associations with quality of life. The associations found encourage the idea that intrapersonal self-transcendence, meaning-in-life, and nurse-patient interaction are powerful health-promoting factors that significantly influence on nursing-home patients' quality of life. Therefore, pedagogical approaches for advancing caregivers' presence and confidence in health-promoting interaction should be upgraded and matured. Proper educational programs for developing interacting skills including assessing and supporting patients' intrapersonal self-transcendence and meaning-in-life should be

  19. Features of the Electromagnetic and Plasma Disturbances Induced at the Altitudes of the Earth's Outer Ionosphere by Modification of the Ionospheric F 2 Region Using High-Power Radio Waves Radiated by the SURA Heating Facility

    NASA Astrophysics Data System (ADS)

    Frolov, V. L.; Rapoport, V. O.; Schorokhova, E. A.; Belov, A. S.; Parrot, M.; Rauch, J.-L.

    2016-08-01

    In this paper we systematize the results of studying the characteristics of the plasma-density ducts, which was conducted in 2005-2010 during the DEMETER-satellite operation. The ducts are formed at altitudes of about 700 km as a result of the ionospheric F 2 region modification by high-power high-frequency radio waves radiated by the midlatitude SURA heating facility. All the performed measurements are used as the basis for determining the formation conditions for such ducts, the duct characteristics are studied, and the opportunities for the duct influence on the ionosphere-magnetosphere coupling and propagation of radio waves of various frequency ranges are demonstrated. The results of numerical simulation of the formation of such ducts are presented.

  20. Information=power. Modern Healthcare's third annual 100 Most Powerful ranking attests to the prominence of IT, quality and patient-safety initiatives.

    PubMed

    Romano, Michael

    2004-08-23

    The growing importance of IT is reflected in Modem Healthcare's third annual ranking of the 100 Most Powerful People in Healthcare. The person topping the 2004 list is a newcomer who recently vaulted to prominence. Who is he, and what other industry movers and shakers made the ranking.