DOE Office of Scientific and Technical Information (OSTI.GOV)
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 capabilitiesmore » 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.« less
Effects of a Meditation Program on Nurses' Power and Quality of Life.
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.
DOE Office of Scientific and Technical Information (OSTI.GOV)
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 ofmore » 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.« less
NASA Astrophysics Data System (ADS)
Kirmani, Sheeraz; Kumar, Brijesh
2018-01-01
“Electric Power Quality (EPQ) is a term that refers to maintaining the near sinusoidal waveform of power distribution bus voltages and currents at rated magnitude and frequency”. Today customers are more aware of the seriousness that the power quality possesses, this prompt the utilities to assure good quality of power to their customer. The power quality is basically customer centric. Increased focus of utilities toward maintaining reliable power supply by employing power quality improvement tools has reduced the power outages and black out considerably. Good power quality is the characteristic of reliable power supply. Low power factor, harmonic pollution, load imbalance, fast voltage variations are some common parameters which are used to define the power quality. If the power quality issues are not checked i.e. the parameters that define power quality doesn't fall within the predefined standards than it will lead into high electricity bill, high running cost in industries, malfunctioning of equipments, challenges in connecting renewable. Capacitor banks, FACTS devices, harmonic filters, SVC’s (static voltage compensators), STATCOM (Static-Compensator) are the solutions to achieve the power quality. The performance of Wind turbine generators is affected by poor quality power, at the same time these wind power generating plant affects the power quality negatively. This paper presents the STATCOM-BESS (battery energy storage system) system and studies its impact on the power quality in a system which consists of wind turbine generator, non linear load, hysteresis controller for controlling the operation of STATCOM and grid. The model is simulated in the MATLAB/Simulink. This scheme mitigates the power quality issues, improves voltage profile and also reduces harmonic distortion of the waveforms. BESS level out the imbalances caused in real power due to intermittent nature of wind power available due to varying wind speeds.
Gender, marital power, and marital quality in later life.
Bulanda, Jennifer Roebuck
2011-01-01
This study uses data from the 1992 Health and Retirement Study to examine gender differences in marital power and marital quality among older adults and to assess whether there are gender differences in the correlates of marital quality and marital power in later life. Results show that women report lower marital happiness, marital interaction, and marital power than do men, on average. These differences persist even after controlling for a number of life-course events and transitions. Further, results show that gender differences are also evident in the relationship of employment, childrearing, caregiving, and health factors with marital quality and power.
NASA Astrophysics Data System (ADS)
Liu, Ruihua; Wang, Rong; Liu, Qunying; Yang, Li; Xi, Chuan; Wang, Wei; Li, Lingzhou; Zhao, Zhoufang; Zhou, Ying
2018-02-01
With China’s new energy generation grid connected capacity being in the forefront of the world and the uncertainty of new energy sources, such as wind energy and solar energy, it is be of great significance to study scientific and comprehensive assessment of power quality. On the foundation of analysizing the current power quality index systematically and objectively, the new energy grid power quality analysis method and comprehensive evaluation method, this paper tentatively explored the trend of the new generation of energy system power quality comprehensive evaluation.
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.
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
DOE Office of Scientific and Technical Information (OSTI.GOV)
Touati, Said; Chennai, Salim; Souli, Aissa
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 wellmore » 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)« less
A Review Analysis of Inverter Topologies for Solar PV Applications Focused on Power Quality
NASA Astrophysics Data System (ADS)
Faruqui, Saad Nazif Ahamad; Anwer, Naqui
2017-10-01
This research article gives widespread review of non-isolated topologies for solar photovoltaic equipments. To relate with available elucidations of the said studied topological arrangement, some conditions have been imposed. The benchmark is based on harmonic distortion as well as power quality issues. Some of the selected solution have been designed and simulated for power quality issues. The best one has been discussed in the paper.
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
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...
Power quality analysis based on spatial correlation
NASA Astrophysics Data System (ADS)
Li, Jiangtao; Zhao, Gang; Liu, Haibo; Li, Fenghou; Liu, Xiaoli
2018-03-01
With the industrialization and urbanization, the status of electricity in the production and life is getting higher and higher. So the prediction of power quality is the more potential significance. Traditional power quality analysis methods include: power quality data compression, disturbance event pattern classification, disturbance parameter calculation. Under certain conditions, these methods can predict power quality. This paper analyses the temporal variation of power quality of one provincial power grid in China from time angle. The distribution of power quality was analyzed based on spatial autocorrelation. This paper tries to prove that the research idea of geography is effective for mining the potential information of power quality.
CALiPER Retail Lamps Study 3.1: Dimming, Flicker, and Power Quality Characteristics of LED A Lamps
DOE Office of Scientific and Technical Information (OSTI.GOV)
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.
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.
NASA Technical Reports Server (NTRS)
Grantham, W. D.; Nguyen, L. T.; Deal, P. L.; Neubauer, M. J.; Smith, P. M.; Gregory, F. D.
1978-01-01
Conventional and powered lift concepts for supersonic approach and landing tasks are considered. Results indicated that the transport concepts had unacceptable low-speed handling qualities with no augmentation, and that in order to achieve satisfactory handling qualities, considerable augmentation was required. The available roll-control power was acceptable for the powered-lift concept.
Power Wheelchair Use in Persons With Amyotrophic Lateral Sclerosis: Changes Over Time.
Ward, Amber Lea; Hammond, Sara; Holsten, Scott; Bravver, Elena; Brooks, Benjamin Rix
2015-01-01
The objectives of this study were to survey persons with Amyotrophic Lateral Sclerosis (ALS) at 1 and 6 months after receiving power wheelchairs to determine long-term use, comfort, and function as well as the power wheelchair's impact on daily tasks and quality of life. A 33-question survey and Psychosocial Impact of Assistive Devices Scale (PIADS) were sent 1 month after getting a new power wheelchair; a follow-up survey was sent at 6 months. Based on satisfaction and feature use survey results, at 1 month, 81% of users found the power wheelchair overall comfort to be high, 88% found their overall mobility to be improved, and 95% found it easy to use. Their quality of life increased and pain decreased at 1 and 6 months. According to the PIADS, the power wheelchair gave users increased ability to participate and sense of competence. This study has important results for the ALS community, as it is the first to assess power wheelchair users at 1 and 6 months after power wheelchair procurement. The results demonstrate the impact the power wheelchair has on mobility, psychosocial issues, functional abilities, and quality of life for a person with ALS.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Ding, Fei; Nagarajan, Adarsh; Chakraborty, Sudipta
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 tomore » 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.« less
To the theory of high-power gyrotrons with uptapered resonators
DOE Office of Scientific and Technical Information (OSTI.GOV)
Dumbrajs, O.; Nusinovich, G. S.
In high-power gyrotrons it is desirable to combine an optimal resonator length with the optimal value of the resonator quality factor. In resonators with the constant radius of the central part, the possibilities of this combination are limited because the quality factor of the resonator sharply increases with its length. Therefore the attempts to increase the length for maximizing the efficiency leads to such increase in the quality factor which makes the optimal current too small. Resonators with slightly uptapered profiles offer more flexibility in this regard. In such resonators, one can separate optimization of the interaction length from optimizationmore » of the quality factor because the quality factor determined by diffractive losses can be reduced by increasing the angle of uptapering. In the present paper, these issues are analyzed by studying as a typical high-power 17 GHz gyrotron which is currently under development in Europe for ITER (http://en.wikipedia.org/wiki/ITER). The effect of a slight uptapering of the resonator wall on the efficiency enhancement and the purity of the radiation spectrum in the process of the gyrotron start-up and power modulation are studied. Results show that optimal modification of the shape of a slightly uptapered resonator may result in increasing the gyrotron power from 1052 to 1360 kW.« less
NASA Astrophysics Data System (ADS)
Sadat Hashemi, Somayeh; Ghavami Sabouri, Saeed; Khorsandi, Alireza
2018-04-01
We present a theoretical model in order to study the effect of a thermally loaded crystal on the quality of a second-harmonic (SH) beam generated in a high-power pumping regime. The model is provided based on using a particular structure of oven considered for MgO:PPsLT nonlinear crystal to compensate for the thermal de-phasing effect that as the pumping power reaches up to 50 W degrades the conversion efficiency and beam quality of the interacting beams. Hereupon, the quality of fundamental beam is involved in the modeling to investigate the final effect on the beam quality of generated SH beam. Beam quality evaluation is subsequently simulated using Hermite-Gaussian modal decomposition approach for a range of fundamental beam qualities varied from 1 to 3 and for different levels of input powers. To provide a meaningful comparison numerical simulation is correlated with real data deduced from a high-power SH generation (SHG) experimental device. It is found that when using the open-top oven scheme and fixing the fundamental M 2-factor at nearly 1, for a range of input powers changing from 15 to 30 W, the M 2-factor of SHG beam is degraded from 9% to 24%, respectively, confirming very good consistency with the reported experimental results.
NASA Astrophysics Data System (ADS)
Zurawski, A. M.
2016-12-01
The objective of this research is to study how emissions from a fossil fuel power plant compare to emissions from a biomass power plant, and how these results can be used to improve current air-quality regulations. Outdoor air quality transcends national and political boundaries. Air pollution monitoring is essential to maintaining quality of life for humans and ecosystems. Due to anthropogenic disturbances (primarily related to burning of fossil fuels), air- quality management has become a priority on a long list of environmental issues. Quantifying and monitoring the largest emitters of greenhouse gases and toxic pollutants is crucial to the creation and enforcement of appropriate environmental protection regulations. Emissions data were collected from January 2010 to January 2016 from sensors installed close to a biomass power plant, and sensors installed close to a fossil fuel and natural gas power plant, in Humboldt County, California. In Humboldt County, where air quality serves as a baseline of air pollution in the United States, data showed that the "green" biomass power plant emitted higher levels of particulate matter compared to the fossil fuel power plant. Additionally, the biomass power plant showed levels of CO2, NOx, and SO2 emissions that suggest its place as a "green" power source should be reconsidered. Our research suggests that regulations need to be reconsidered given the potential for high pollutant emissions from biomass plants.
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.
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.
Federal Register 2010, 2011, 2012, 2013, 2014
2010-05-21
..., navigation, irrigation, power, water supply, water quality, recreation, and fish and wildlife. ADDRESSES..., navigation, irrigation, power, water supply, water quality, recreation, and fish and wildlife. Section 108 of... judicial rulings to determine if changes to the authorized project purposes and existing federal water...
Power and Resistance: Leading Change in Medical Education
ERIC Educational Resources Information Center
Sundberg, Kristina; Josephson, Anna; Reeves, Scott; Nordquist, Jonas
2017-01-01
A key role for educational leaders within undergraduate medical education is to continually improve the quality of education; global quality health care is the goal. This paper reports the findings from a study employing a power model to highlight how educational leaders influence the development of undergraduate medical curricula and the…
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.
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
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.
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.
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
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.
Study of ultrasonic melt treatment on the quality of horizontal continuously cast Al-1%Si alloy.
Li, Xin-Tao; Li, Ting-Ju; Li, Xi-Meng; Jin, Jun-Ze
2006-02-01
The fluctuation of the melt temperature in a tundish was measured during casting and experiments were conducted to investigate the effects of ultrasonic melt treatment on the surface quality and solidification structures of Al-1%Si ingots. The results show that the uniformity of melt temperature was enhanced with the application of ultrasonic melt treatment. When the ultrasonic power is 1,000W, the surface quality was evidently improved and grains of cast ingots were refined. Moreover, EPMA analysis was adopted to study the relationship between the ultrasonic power and boundary segregation of Si element. The result shows that boundary segregation is suppressed with the increase of ultrasonic power and the phenomenon was theoretically interpreted.
Designing image segmentation studies: Statistical power, sample size and reference standard quality.
Gibson, Eli; Hu, Yipeng; Huisman, Henkjan J; Barratt, Dean C
2017-12-01
Segmentation algorithms are typically evaluated by comparison to an accepted reference standard. The cost of generating accurate reference standards for medical image segmentation can be substantial. Since the study cost and the likelihood of detecting a clinically meaningful difference in accuracy both depend on the size and on the quality of the study reference standard, balancing these trade-offs supports the efficient use of research resources. In this work, we derive a statistical power calculation that enables researchers to estimate the appropriate sample size to detect clinically meaningful differences in segmentation accuracy (i.e. the proportion of voxels matching the reference standard) between two algorithms. Furthermore, we derive a formula to relate reference standard errors to their effect on the sample sizes of studies using lower-quality (but potentially more affordable and practically available) reference standards. The accuracy of the derived sample size formula was estimated through Monte Carlo simulation, demonstrating, with 95% confidence, a predicted statistical power within 4% of simulated values across a range of model parameters. This corresponds to sample size errors of less than 4 subjects and errors in the detectable accuracy difference less than 0.6%. The applicability of the formula to real-world data was assessed using bootstrap resampling simulations for pairs of algorithms from the PROMISE12 prostate MR segmentation challenge data set. The model predicted the simulated power for the majority of algorithm pairs within 4% for simulated experiments using a high-quality reference standard and within 6% for simulated experiments using a low-quality reference standard. A case study, also based on the PROMISE12 data, illustrates using the formulae to evaluate whether to use a lower-quality reference standard in a prostate segmentation study. Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.
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 ...
NASA Astrophysics Data System (ADS)
Al-Aboodi, Ali H.; Abbas, Sarmad A.; Ibrahim, Husham T.
2018-05-01
The main object of this research is to assess the water quality of Shatt Al-Arab River and its suitability for various purposes near power plants (Hartha and Najibia) through physical and chemical analysis [temperature, pH, EC, Cl-, Na+, K+, Ca+2, Mg+2, HCO3 -, NO3 -, SO 4 -2 , Fe+, total alkalinity, total hardness, biological oxygen demand (BOD5), NH4 +, and NO2 -] using water quality index (WQI), organic pollution index (OPI), sodium adsorption ratio (SAR), and percentage of sodium ion (Na%) during the dry season (August, 2016) and the wet season (January, 2017). WQI of Shatt Al-Arab falls under very poor quality during summer season, while it ranges from very poor quality to unsuitable for drinking purposes during winter season. There is a clear effect of power plants on water quality. Hartha and Najibia power plants contribute to the deterioration of water quality by increasing the percentage ratio of WQI near these plants by 13.22 and 9.69%, respectively, compared to the north sites of these plants during summer season. The percentage ratios of increased WQI near Hartha and Najibia power plants compared to the north sites of these plants are 17.93 and 15.92%, respectively, during winter season. Water quality of Shatt Al-Arab falls under a high level of organic pollution during the summer and winter seasons. There is a slight effect by the power plants on the OPI. Hartha and Najibia power plants contributed to the change of the OPI by 10% compared to the north site of Hartha power plant. According to the comparison between the SAR values which represent the suitability of water for serve irrigation purposes and SAR values of Shatt Al-Arab, all sites lie in the first class (excellent). According to Na+%, the type of surface water in the studied area lies in good class during winter season and permissible class during summer season.
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.
Vavken, P; Culen, G; Dorotka, R
2008-01-01
The demand to routinely apply evidence-based methods in orthopedic surgery increases steadily. In order to do so, however, the validity and reliability of the "evidence" has to be scrutinized. The object of this study was to assess the quality of the most recent orthopedic evidence and to determine variables that have an influence on quality. All 2006 controlled trials from orthopedic journals with high impact factors were analysed in a cross-sectional study. A score based on the CONSORT statement was used to assess study quality. Selected variables were tested for their influence on the quality of the study. Two independent blinded observers reviewed 126 studies. The overall quality was moderate to high. The most neglected parameters were power analysis, intention-to-treat, and concealment. The participation of a methodologically trained investigator increases study quality significantly. There was no difference in study quality irrespective of whether or not there was statistically significant result. Using our quality score we were able show fairly good results for recent orthopedic studies. The most frequently neglected issues in orthopedic research are blinding, power analysis, and intention-to-treat. This may distort the results of clinical investigations considerably and, especially, lack of concealment causes false-positive findings. Our data show furthermore that participation of a methodologist significantly increases quality of the study and consequently strengthens the reliability of results.
Aissa, Oualid; Moulahoum, Samir; Colak, Ilhami; Babes, Badreddine; Kabache, Nadir
2017-10-12
This paper discusses the use of the concept of classical and predictive direct power control for shunt active power filter function. These strategies are used to improve the active power filter performance by compensation of the reactive power and the elimination of the harmonic currents drawn by non-linear loads. A theoretical analysis followed by a simulation using MATLAB/Simulink software for the studied techniques has been established. Moreover, two test benches have been carried out using the dSPACE card 1104 for the classic and predictive DPC control to evaluate the studied methods in real time. Obtained results are presented and compared in this paper to confirm the superiority of the predictive technique. To overcome the pollution problems caused by the consumption of fossil fuels, renewable energies are the alternatives recommended to ensure green energy. In the same context, the tested predictive filter can easily be supplied by a renewable energy source that will give its impact to enhance the power quality.
Khodabakhshi Koolaee, Anahita; Shaghelani Lor, Hossein; Soleimani, Ali Akbar; Rahmatizadeh, Masoumeh
2014-06-01
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. The present study compares the family power structure and parent-child relationship quality in delinquent and non-delinquent young subjects in Tehran. 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. 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). 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.
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 amplitudes and frequencies, an Artificial Neural Network is employed to identify the switched capacitor by using amplitudes and frequencies extracted from the transient signal. The new algorithms for detecting, tracking, and classifying power quality disturbances demonstrate the potential for further development of a fully automated recognition system for the assessment of power quality. This is possible because the implementation of the proposed algorithms for the power quality monitoring device becomes a straight forward process by modifying the device software.
1998-06-01
quality management can have on the intermediate level of maintenance. Power quality management is a preventative process that focuses on identifying and correcting problems that cause bad power. Using cost-benefit analysis we compare the effects of implementing a power quality management program at AIMD Lemoore and AIMD Fallon. The implementation of power quality management can result in wide scale logistical support changes in regards to the life cycle costs of maintaining the DoD’s current inventory
Simulation and study of power quality issues in a fixed speed wind farm substation.
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.
Simulation and Study of Power Quality Issues in a Fixed Speed Wind Farm Substation
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
Power, uncertainty, self-transcendence, and quality of life in breast cancer survivors.
Farren, Arlene T
2010-01-01
The purpose of the study was to examine the relations among power, uncertainty, self-transcendence, and quality of life in breast cancer survivors from the perspective of Rogers' science of unitary human beings. A correlational, cross-sectional study with purposive sampling (n = 104) was conducted. The results included statistically significant correlations, explained variance, and mediating relations among the pattern manifestations. The researcher concluded that there are complex and synergistic relations among the cluster of field pattern manifestations that contribute to quality of life in breast cancer survivors. Implications for theory, research, and practice are discussed.
Southern Nevada air quality study
DOT National Transportation Integrated Search
2007-01-01
The Southern Nevada Air Quality Study (SNAQS) created cross-plume and in-plume measurement systems to quantify emissions distributions and source profiles from transportation emissions, specifically gasoline and diesel powered vehicles. The cross-plu...
Discussion on mass concrete construction of wind turbine generator foundation
NASA Astrophysics Data System (ADS)
Shang, Liang; Wu, Chaoxiang; Yin, Xiaoyong
2018-04-01
Wind power is one of the main power sources currently. China has rich wind power resources, wind power plants are developed faster and faster. However, China wind power construction started late, which is lack of relevant experience technology. It is easy to produce quality problems. The key to the construction quality of wind power plant is the construction quality of mass concrete construction. Therefore, construction technology and quality control of wind turbine generator foundation mass concrete are discussed and analyzed in the paper.
Research on the effects of wind power grid to the distribution network of Henan province
NASA Astrophysics Data System (ADS)
Liu, Yunfeng; Zhang, Jian
2018-04-01
With the draining of traditional energy, all parts of nation implement policies to develop new energy to generate electricity under the favorable national policy. The wind has no pollution, Renewable and other advantages. It has become the most popular energy among the new energy power generation. The development of wind power in Henan province started relatively late, but the speed of the development is fast. The wind power of Henan province has broad development prospects. Wind power has the characteristics of volatility and randomness. The wind power access to power grids will cause much influence on the power stability and the power quality of distribution network, and some areas have appeared abandon the wind phenomenon. So the study of wind power access to power grids and find out improvement measures is very urgent. Energy storage has the properties of the space transfer energy can stabilize the operation of power grid and improve the power quality.
Examining System-Wide Impacts of Solar PV Control Systems with a Power Hardware-in-the-Loop Platform
DOE Office of Scientific and Technical Information (OSTI.GOV)
Williams, Tess L.; Fuller, Jason C.; Schneider, Kevin P.
2014-06-08
High penetration levels of distributed solar PV power generation can lead to adverse power quality impacts, such as excessive voltage rise, voltage flicker, and reactive power values that result in unacceptable voltage levels. Advanced inverter control schemes have been developed that have the potential to mitigate many power quality concerns. However, local closed-loop control may lead to unintended behavior in deployed systems as complex interactions can occur between numerous operating devices. To enable the study of the performance of advanced control schemes in a detailed distribution system environment, a test platform has been developed that integrates Power Hardware-in-the-Loop (PHIL) withmore » concurrent time-series electric distribution system simulation. In the test platform, GridLAB-D, a distribution system simulation tool, runs a detailed simulation of a distribution feeder in real-time mode at the Pacific Northwest National Laboratory (PNNL) and supplies power system parameters at a point of common coupling. At the National Renewable Energy Laboratory (NREL), a hardware inverter interacts with grid and PV simulators emulating an operational distribution system. Power output from the inverters is measured and sent to PNNL to update the real-time distribution system simulation. The platform is described and initial test cases are presented. The platform is used to study the system-wide impacts and the interactions of inverter control modes—constant power factor and active Volt/VAr control—when integrated into a simulated IEEE 8500-node test feeder. We demonstrate that this platform is well-suited to the study of advanced inverter controls and their impacts on the power quality of a distribution feeder. Additionally, results are used to validate GridLAB-D simulations of advanced inverter controls.« less
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.
Muscle Power Is an Independent Determinant of Pain and Quality of Life in Knee Osteoarthritis.
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.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Ding, Fei; Nagarajan, Adarsh; Baggu, Murali
This paper evaluated the impact of smart inverter Volt-VAR function on voltage reduction energy saving and power quality in electric power distribution systems. A methodology to implement the voltage reduction optimization was developed by controlling the substation LTC and capacitor banks, and having smart inverters participate through their autonomous Volt-VAR control. In addition, a power quality scoring methodology was proposed and utilized to quantify the effect on power distribution system power quality. All of these methodologies were applied to a utility distribution system model to evaluate the voltage reduction energy saving and power quality under various PV penetrations and smartmore » inverter densities.« less
PQScal (Power Quality Score Calculation for Distribution Systems with DER Integration)
DOE Office of Scientific and Technical Information (OSTI.GOV)
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 onmore » 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.« less
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.
Air quality impacts of projections of natural gas-fired distributed generation
NASA Astrophysics Data System (ADS)
Horne, Jeremy R.; Carreras-Sospedra, Marc; Dabdub, Donald; Lemar, Paul; Nopmongcol, Uarporn; Shah, Tejas; Yarwood, Greg; Young, David; Shaw, Stephanie L.; Knipping, Eladio M.
2017-11-01
This study assesses the potential impacts on emissions and air quality from the increased adoption of natural gas-fired distributed generation of electricity (DG), including displacement of power from central power generation, in the contiguous United States. The study includes four major tasks: (1) modeling of distributed generation market penetration; (2) modeling of central power generation systems; (3) modeling of spatially and temporally resolved emissions; and (4) photochemical grid modeling to evaluate the potential air quality impacts of increased DG penetration, which includes both power-only DG and combined heat and power (CHP) units, for 2030. Low and high DG penetration scenarios estimate the largest penetration of future DG units in three regions - New England, New York, and California. Projections of DG penetration in the contiguous United States estimate 6.3 GW and 24 GW of market adoption in 2030 for the low DG penetration and high DG penetration scenarios, respectively. High DG penetration (all of which is natural gas-fired) serves to offset 8 GW of new natural gas combined cycle (NGCC) units, and 19 GW of solar photovoltaic (PV) installations by 2030. In all scenarios, air quality in the central United States and the northwest remains unaffected as there is little to no DG penetration in those states. California and several states in the northeast are the most impacted by emissions from DG units. Peak increases in maximum daily 8-h average ozone concentrations exceed 5 ppb, which may impede attainment of ambient air quality standards. Overall, air quality impacts from DG vary greatly based on meteorological conditions, proximity to emissions sources, the number and type of DG installations, and the emissions factors used for DG units.
Tsuboyama, Takahiro; Jost, Gregor; Pietsch, Hubertus; Tomiyama, Noriyuki
2017-09-01
The aim of this study was to compare power versus manual injection in bolus shape and image quality on contrast-enhanced magnetic resonance angiography (CE-MRA). Three types of CE-MRA (head-neck 3-dimensional [3D] MRA with a test-bolus technique, thoracic-abdominal 3D MRA with a bolus-tracking technique, and thoracic-abdominal time-resolved 4-dimensional [4D] MRA) were performed after power and manual injection of gadobutrol (0.1 mmol/kg) at 2 mL/s in 12 pigs (6 sets of power and manual injections for each type of CE-MRA). For the quantitative analysis, the signal-to-noise ratio was measured on ascending aorta, descending aorta, brachiocephalic trunk, common carotid artery, and external carotid artery on the 6 sets of head-neck 3D MRA, and on ascending aorta, descending aorta, brachiocephalic trunk, abdominal aorta, celiac trunk, and renal artery on the 6 sets of thoracic-abdominal 3D MRA. Bolus shapes were evaluated on the 6 sets each of test-bolus scans and 4D MRA. For the qualitative analysis, arterial enhancement, superimposition of nontargeted enhancement, and overall image quality were evaluated on 3D MRA. Visibility of bolus transition was assessed on 4D MRA. Intraindividual comparison between power and manual injection was made by paired t test, Wilcoxon rank sum test, and analysis of variance by ranks. Signal-to-noise ratio on 3D MRA was statistically higher with power injection than with manual injection (P < 0.001). Bolus shapes (test-bolus, 4D MRA) were represented by a characteristic standard bolus curve (sharp first-pass peak followed by a gentle recirculation peak) in all the 12 scans with power injection, but only in 1 of the 12 scans with manual injection. Standard deviations of time-to-peak enhancement were smaller in power injection than in manual injection. Qualitatively, although both injection methods achieved diagnostic quality on 3D MRA, power injection exhibited significantly higher image quality than manual injection (P = 0.001) due to significantly higher arterial enhancement (P = 0.031) and less superimposition of nontargeted enhancement (P = 0.001). Visibility of bolus transition on 4D MRA was significantly better with power injection than with manual injection (P = 0.031). Compared with manual injection, power injection provides more standardized bolus shapes and higher image quality due to higher arterial enhancement and less superimposition of nontargeted vessels.
Examining System-Wide Impacts of Solar PV Control Systems with a Power Hardware-in-the-Loop Platform
DOE Office of Scientific and Technical Information (OSTI.GOV)
Williams, Tess L.; Fuller, Jason C.; Schneider, Kevin P.
2014-10-11
High penetration levels of distributed solar PV power generation can lead to adverse power quality impacts such as excessive voltage rise, voltage flicker, and reactive power values that result in unacceptable voltage levels. Advanced inverter control schemes have been proposed that have the potential to mitigate many power quality concerns. However, closed-loop control may lead to unintended behavior in deployed systems as complex interactions can occur between numerous operating devices. In order to enable the study of the performance of advanced control schemes in a detailed distribution system environment, a Hardware-in-the-Loop (HIL) platform has been developed. In the HIL system,more » GridLAB-D, a distribution system simulation tool, runs in real-time mode at the Pacific Northwest National Laboratory (PNNL) and supplies power system parameters at a point of common coupling to hardware located at the National Renewable Energy Laboratory (NREL). Hardware inverters interact with grid and PV simulators emulating an operational distribution system and power output from the inverters is measured and sent to PNNL to update the real-time distribution system simulation. The platform is described and initial test cases are presented. The platform is used to study the system-wide impacts and the interactions of controls applied to inverters that are integrated into a simulation of the IEEE 8500-node test feeder, with inverters in either constant power factor control or active volt/VAR control. We demonstrate that this HIL platform is well-suited to the study of advanced inverter controls and their impacts on the power quality of a distribution feeder. Additionally, the results from HIL are used to validate GridLAB-D simulations of advanced inverter controls.« less
NASA Technical Reports Server (NTRS)
Corliss, L. D.
1982-01-01
The helicopter configuration with an rpm-governed gas-turbine engine was examined. A wide range of engine response time, vehicle damping and sensitivity, and excess power levels was studied. The data are compared with the existing handling-qualities specifications, MIL-F-83300 and AGARD 577, and in general show a need for higher minimums when performing such NOE maneuvers as a dolphin and bob-up task.
Research on Holographic Evaluation of Service Quality in Power Data Network
NASA Astrophysics Data System (ADS)
Wei, Chen; Jing, Tao; Ji, Yutong
2018-01-01
With the rapid development of power data network, the continuous development of the Power data application service system, more and more service systems are being put into operation. Following this, the higher requirements for network quality and service quality are raised, in the actual process for the network operation and maintenance. This paper describes the electricity network and data network services status. A holographic assessment model was presented to achieve a comprehensive intelligence assessment on the power data network and quality of service in the operation and maintenance on the power data network. This evaluation method avoids the problems caused by traditional means which performs a single assessment of network performance quality. This intelligent Evaluation method can improve the efficiency of network operation and maintenance guarantee the quality of real-time service in the power data network..
The particulate-related health benefits of reducing power plant emissions
DOE Office of Scientific and Technical Information (OSTI.GOV)
Schneider, C.
The report estimates the adverse human health effects due to exposure to particulate matter from power plants. Power plants are significant emitters of sulfur dioxide and nitrogen oxides. In many parts of the U.S., especially the Midwest, power plants are the largest contributors. These gases are harmful themselves, and they contribute to the formation of acid rain and particulate matter. Particulate matter reduces visibility, often producing a milky haze that blankets wide regions, and it is a serious public health problem. Over the past decade and more, numerous studies have linked particulate matter to a wide range of adverse healthmore » effects in people of all ages. Epidemiologists have consistently linked particulate matter with effects ranging from premature death, hospital admissions and asthma attacks to chronic bronchitis. This study documents the health impacts from power plant air pollution emissions. Using the best available emissions and air quality modeling programs, the stud y forecasts ambient air quality for a business-as-usual baseline scenario for 2007, assuming full implementation of the Acid Rain program and the U.S. Environmental Protection Agency's (EPA) Summer Smog rule (the 1999 NO{sub x} SIP Call). The study then estimates the attributable health impacts from all power plant emissions. Finally, the study estimates air quality for a specific policy alternative: reducing total power plant emissions of SO{sub 2} and NO{sub x} 75 percent form the levels emitted in 1997. The difference between this '75 percent reduction scenario' and the baseline provides an estimate of the health effects that would be avoided by this reduction in power plant emissions. In addition to the policy scenario, the work involved performing sensitivity analyses to examine alternative emission reductions and forecast ambient air quality using a second air quality model. EPA uses both air quality models extensively, and both suggest that power plants make a large contribution to ambient particulate matter levels in the Eastern U.S. To put the power plant results in context, air pollution from all on-road and off-road diesel engine emissions was also examined. The results suggest that both power plants and diesel engines make a large contribution to ambient particulate matter levels and the associated health effects. Chapter 2 describes the development of the emissions inventory. Chapter 3 describes the methods used to estimate changes in particulate matter concentrations. Chapter 4 describes general issues arising in estimating and valuing changes in adverse health effects associated with changes in particulate matter. Chapter 5 describes in some detail the methods used for estimating and valuing adverse health effects, and in Chapter 6, the results of the various analyses are presented. The study includes 6 appendices. Appendix A provides results of this analysis for all metropolitan areas in the U.S. and a list of the counties in each metropolitan area. Appendices B, C and D present a detailed examination of how the pollution emission estimates were derived and then translated into forecasts of ambient particulate matter levels.« less
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.
NASA Astrophysics Data System (ADS)
Petrova, T. I.; Orlov, K. A.; Dooley, R. B.
2017-01-01
One of the ways for improving the operational reliability and economy of thermal power station equipment, including combined-cycle equipment, is to decrease the rates of the corrosion of constructional materials and the formation of scales in the water-steam circuit. These processes can be reduced to a minimum via the use of water with a minimum content of admixtures and the correction treatment of a heat-transfer fluid. The International Association for the Properties of Water and Steam (IAPWS), which unites specialists from every country of the world, has developed water and steam quality standards for power station equipment of different types on the basis of theoretical studies and long-term experience in the operation of power plants in 21 countries. Different water chemistry regimes are currently used at conventional and combined-cycle thermal power stations. This paper describes the conditions for the implementation of water chemistry regimes with the use of sodium salts of phosphoric acid and NaOH for the quality correction of boiler water. Water and steam quality standards and some recommendations for their maintenance under different operational conditions are given for each of the considered water chemistry regimes. The standards are designed for the water-steam circuit of conventional and combined-cycle thermal power stations. It is pointed out that the quality control of a heat-transfer fluid must be especially careful at combined-cycle thermal power stations with frequent startups and shutdowns.
Cultural values and health service quality in China.
Polsa, Pia; Fuxiang, Wei; Sääksjärvi, Maria; Shuyuan, Pei
2013-01-01
Several service quality studies show how cultural features may influence the way service quality is perceived. However, few studies specifically describe culture's influence on health service quality. Also, there are few studies that take into account patients' health service quality perceptions. This article seeks to present a first step to fill these gaps by examining patients' cultural values and their health service quality assessments. The study draws on published work and applies its ideas to Chinese healthcare settings. Data consist of hospital service perceptions in the People's Republic of China (PRC), a society that is socially, economically and culturally undergoing major changes. In total, 96 patients were surveyed. Data relationships were tested using partial least square (PLS) analysis. Findings show that Chinese patients' cultural values and their health service assessments are related and that the cultural values themselves seem to be changing. Additionally, further analyses provided interesting results pointing to which cultural values influenced service quality perceptions. The strongest service quality predictor was power distance. The sample is relatively small and collected from only one major hospital in China. Therefore, future research should extend the sample size and scope. Follow-up research could also include cross-cultural investigations of perceived health service quality to substantiate cultural influences on health service quality perceptions. In line with similar research in other contexts, the study confirms that power distance has a significant relationship with service quality perceptions. The study contributes to existing health service literature by offering patients' views on health service quality and by describing relationships between health service perceptions and cultural values--the study's main contribution.
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.
Response of Rocky Mountain elk (Cervus elaphus) to wind-power development
Walter, W. David; Leslie, David M.; Jenks, J.A.
2006-01-01
Wind-power development is occurring throughout North America, but its effects on mammals are largely unexplored. Our objective was to determine response (i.e., home-range, diet quality) of Rocky Mountain elk (Cervus elaphus) to wind-power development in southwestern Oklahoma. Ten elk were radiocollared in an area of wind-power development on 31 March 2003 and were relocated bi-weekly through March 2005. Wind-power construction was initiated on 1 June 2003 and was completed by December 2003 with 45 active turbines. The largest composite home range sizes (>80 km2) occurred April-June and September, regardless of the status of wind-power facility development. The smallest home range sizes (<50 km2) typically occurred in October-February when elk aggregated to forage on winter wheat. No elk left the study site during the study and elk freely crossed the gravel roads used to access the wind-power facility. Carbon and nitrogen isotopes and percent nitrogen in feces suggested that wind-power development did not affect nutrition of elk during construction. Although disturbance and loss of some grassland habitat was apparent, elk were not adversely affected by wind-power development as determined by home range and dietary quality.
Power transformation for enhancing responsiveness of quality of life questionnaire.
Zhou, YanYan Ange
2015-01-01
We investigate the effect of power transformation of raw scores on the responsiveness of quality of life survey. The procedure maximizes the paired t-test value on the power transformed data to obtain an optimal power range. The parallel between the Box-Cox transformation is also investigated for the quality of life data.
NASA Technical Reports Server (NTRS)
Corless, L. D.; Blanken, C. L.
1983-01-01
A multi-phase program is being conducted to study, in a generic sense and through ground simulation, the effects of engine response, rotor inertia, rpm control, excess power, and vertical damping on specific maneuvers included in nap-of-the-Earth (NOE) operations. The helicopter configuration with an rpm-governed gas-turbine engine are considered. Handling-qualities-criteria data are considered in light of aspects peculiar to rotary-wing and NOE operations. The results of three moving-based piloted simulation studies are summarized and the frequency, characteristics of the helicopter thrust response which set it apart from other VTOL types are explained. Power-system response is affected by both the engine-governor response and the level of rotor inertia. However, results indicate that with unlimited power, variations in engine response can have a significant effect on pilot rating, whereas changes in rotor inertia, in general, do not. The results also show that any pilot interaction required to maintain proper control can significantly degrade handling qualities. Data for variations in vertical damping and collective sensitivity are compared with existing handling-qualities specifications, MIL-F-83300 and AGARD 577, and show a need for higher minimums for both damping and sensitivity for the bob-up task. Results for cases of limited power are also shown.
Domínguez-Vicent, Alberto; Esteve-Taboada, Jose Juan; Recchioni, Alberto; Brautaset, Rune
2018-05-01
To assess the power profile and in vitro optical quality of scleral contact lenses with different powers as a function of the optical aperture. The mini and semiscleral contact lenses (Procornea) were measured for five powers per design. The NIMO TR-1504 (Lambda-X) was used to assess the power profile and Zernike coefficients of each contact lens. Ten measurements per lens were taken at 3- and 6-mm apertures. Furthermore, the optical quality of each lens was described in Zernike coefficients, modulation transfer function, and point spread function (PSF). A convolution of each lens PSF with an eye-chart image was also computed. The optical power fluctuated less than 0.5 diopters (D) along the optical zone of each lens. However, the optical power obtained for some lenses did not match with its corresponding nominal one, the maximum difference being 0.5 D. In optical quality, small differences were obtained among all lenses within the same design. Although significant differences were obtained among lenses (P<0.05), these showed small impact in the image quality of each convolution. Insignificant power fluctuations were obtained along the optical zone measured for each scleral lens. Additionally, the optical quality of both lenses has showed to be independent of the lens power within the same aperture.
Lee, Jungwook; Chung, Kwangsue
2011-01-01
Wireless sensor networks collect data from several nodes dispersed at remote sites. Sensor nodes can be installed in harsh environments such as deserts, cities, and indoors, where the link quality changes considerably over time. Particularly, changes in transmission power may be caused by temperature, humidity, and other factors. In order to compensate for link quality changes, existing schemes detect the link quality changes between nodes and control transmission power through a series of feedback processes, but these approaches can cause heavy overhead with the additional control packets needed. In this paper, the change of the link quality according to temperature is examined through empirical experimentation. A new power control scheme combining both temperature-aware link quality compensation and a closed-loop feedback process to adapt to link quality changes is proposed. We prove that the proposed scheme effectively adapts the transmission power to the changing link quality with less control overhead and energy consumption.
Power Soccer: Experiences of Students Using Power Wheelchairs in a Collegiate Athletic Club
ERIC Educational Resources Information Center
Wessel, Roger D.; Wentz, Joel; Markle, Larry L.
2011-01-01
Intercollegiate athletics provides an opportunity for improving the societal perceptions and overall quality of life of physically disabled persons. Athletic opportunities in the collegiate atmosphere allow such students to be socially, psychologically, and physically engaged. This study focused on how involvement in a Power Soccer collegiate…
Assumpção, Ana; Pagano, Tatiana; Matsutani, Luciana A; Ferreira, Elizabeth A G; Pereira, Carlos A B; Marques, Amélia P
2010-01-01
Fibromyalgia is a painful syndrome characterized by widespread chronic pain and associated symptoms with a negative impact on quality of life. Considering the subjectivity of quality of life measurements, the aim of this study was to verify the discriminating power of two quality of life questionnaires in patients with fibromyalgia: the generic Medical Outcomes Study 36-Item Short-Form Health Survey (SF-36) and the specific Fibromyalgia Impact Questionnaire (FIQ). A cross-sectional study was conducted on 150 participants divided into Fibromyalgia Group (FG) and Control Group (CG) (n=75 in each group). The participants were evaluated using the SF-36 and the FIQ. The data were analyzed by the Student t-test (α=0.05) and inferential analysis using the Receiver Operating Characteristics (ROC) Curve--sensitivity, specificity and area under the curve (AUC). The significance level was 0.05. The sample was similar for age (CG: 47.8 ± 8.1; FG: 47.0 ± 7.7 years). A significant difference was observed in quality of life assessment in all aspects of both questionnaires (p<0.05). Higher sensibility, specificity and AUC were obtained by the FIQ (96%, 96%, 0.985, respectively), followed by the SF-36 (88%, 89% and 0.948 AUC). The FIQ presented the highest sensibility, specificity and AUC showing the most discriminating power. However the SF-36 is also a good instrument to assess quality of life in fibromyalgia patients, and we suggest that both should be used in parallel because they evaluate relevant and complementary aspects of quality of life.
A design of wireless sensor networks for a power quality monitoring system.
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.
Piao, Wenhua; Kim, Changwon; Cho, Sunja; Kim, Hyosoo; Kim, Minsoo; Kim, Yejin
2016-12-01
In wastewater treatment plants (WWTPs), the portion of operating costs related to electric power consumption is increasing. If the electric power consumption decreased, however, it would be difficult to comply with the effluent water quality requirements. A protocol was proposed to minimize the environmental impacts as well as to optimize the electric power consumption under the conditions needed to meet the effluent water quality standards in this study. This protocol was comprised of six phases of procedure and was tested using operating data from S-WWTP to prove its applicability. The 11 major operating variables were categorized into three groups using principal component analysis and K-mean cluster analysis. Life cycle assessment (LCA) was conducted for each group to deduce the optimal operating conditions for each operating state. Then, employing mathematical modeling, six improvement plans to reduce electric power consumption were deduced. The electric power consumptions for suggested plans were estimated using an artificial neural network. This was followed by a second round of LCA conducted on the plans. As a result, a set of optimized improvement plans were derived for each group that were able to optimize the electric power consumption and life cycle environmental impact, at the same time. Based on these test results, the WWTP operating management protocol presented in this study is deemed able to suggest optimal operating conditions under which power consumption can be optimized with minimal life cycle environmental impact, while allowing the plant to meet water quality requirements.
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.
NASA Astrophysics Data System (ADS)
Taruna, I.; Hakim, A. L.; Sutarsi
2018-03-01
Production of breadfruit powder has been an option to make easy its uses in various food processing. Accordingly, there is a need recently to apply advanced drying method, i.e. microwave drying, for improving quality since conventional methods produced highly variable product quality and required longer process. The present work was aimed to study the effect of microwave power and grinding time on physical quality of breadfruit powders. The experiment was done initially by drying breadfruit slices in a microwave dryer at power level of 420, 540, and 720 W and then grinding for 3, 5, and 7 min to get powdery product of less than 80 mesh. The physical quality of breadfruit powders were measured in terms of fineness modulus (FM), average particle size (D), whiteness (WI), total color difference (ΔE), water absorption (Wa), oil absorption (La), bulk density (ρb) and consistency gel (Gc). The results showed that physical quality of powders and its ranged-values included the FM (2.08-2.62), D (0.44-0.68 mm), WI (75.2-77.9), ΔE (7.4-10.5), Wa (5.5-6.2 ml/g), La (0.7-0.9 ml/g), ρb (0.62-0.70 g/cm3) and Gc (41.3-46.8 mm). The experiment revealed that variation of microwave power and grinding time affected significantly the quality of the breadfruit powders. However, microwave power was more dominant factor to affect quality of breadfruit powder in comparison to the grinding time.
Impact of Ego-resilience and Family Function on Quality of Life in Childhood Leukemia Survivors
CHO, Ok-Hee; YOO, Yang-Sook; HWANG, Kyung-Hye
2016-01-01
Background: This study aimed to examine the impact of ego-resilience and family function on quality of life in childhood leukemia survivors. Methods: This study targeted 100 pediatric leukemia survivors, who visited the Pediatric Hemato-Oncology Center in South Korea from Aug to Dec 2011. A structured questionnaire of ego-resilience, family function and quality of life used to collect data through direct interview with the pediatric patients and their parents. The correlation between the study variables analyzed using the Pearson’s correlation coefficient, and the impact on quality of life analyzed using a stepwise multiple regression. Results: Ego-resilience (r = 0.69, P<0.001) and family function (r =0.46, P< 0.001) had a positive correlation with quality of life and all the sub-categories of quality of life. Ego-resilience was a major factor affecting quality of life in childhood leukemia survivors, with an explanatory power of 48%. The explanatory power for quality of life increased to 53% when age and family function were included. Conclusion: Ego-resilience, age, and family function affect quality of life in childhood leukemia survivors. Hence, strategies are required to construct age-matched programs to improve quality of life, in order to help restore the necessary ego-resilience and to strengthen family function in childhood leukemia survivors. PMID:28032062
Recent experience with the CQE{trademark}
DOE Office of Scientific and Technical Information (OSTI.GOV)
Harrison, C.D.; Kehoe, D.B.; O`Connor, D.C.
1997-12-31
CQE (the Coal Quality Expert) is a software tool that brings a new level of sophistication to fuel decisions by seamlessly integrating the system-wide effects of fuel purchase decisions on power plant performance, emissions, and power generation costs. The CQE technology, which addresses fuel quality from the coal mine to the busbar and the stack, is an integration and improvement of predecessor software tools including: EPRI`s Coal Quality Information System, EPRI`s Coal Cleaning Cost Model, EPRI`s Coal Quality Impact Model, and EPRI and DOE models to predict slagging and fouling. CQE can be used as a stand-alone workstation or asmore » a network application for utilities, coal producers, and equipment manufacturers to perform detailed analyses of the impacts of coal quality, capital improvements, operational changes, and/or environmental compliance alternatives on power plant emissions, performance and production costs. It can be used as a comprehensive, precise and organized methodology for systematically evaluating all such impacts or it may be used in pieces with some default data to perform more strategic or comparative studies.« less
The effect of foot orthoses and in-shoe wedges during cycling: a systematic review
2014-01-01
Background The use of foot orthoses and in-shoe wedges in cycling are largely based on theoretical benefits and anecdotal evidence. This review aimed to systematically collect all published research on this topic, critically evaluate the methods and summarise the findings. Methods Study inclusion criteria were: all empirical studies that evaluated the effects of foot orthoses or in-shoe wedges on cycling; outcome measures that investigated physiological parameters, kinematics and kinetics of the lower limb, and power; and, published in English. Studies were located by data-base searching (Medline, CINAHL, Embase and SPORTDiscus) and hand-searching in February 2014. Selected studies were assessed for methodological quality using a modified Quality Index. Data were synthesised descriptively. Meta-analysis was not performed as the included studies were not sufficiently homogeneous to provide a meaningful summary. Results Six studies were identified as meeting the eligibility criteria. All studies were laboratory-based and used a repeated measures design. The quality of the studies varied, with Quality Index scores ranging from 7 to 10 out of 14. Five studies investigated foot orthoses and one studied in-shoe wedges. Foot orthoses were found to increase contact area in the midfoot, peak pressures under the hallux and were perceived to provide better arch support, compared to a control. With respect to physiological parameters, contrasting findings have been reported regarding the effect foot orthoses have on oxygen consumption. Further, foot orthoses have been shown to not provide effects on lower limb kinematics and perceived comfort. Both foot orthoses and in-shoe wedges have been shown to provide no effect on power. Conclusion In general, there is limited high-quality research on the effects foot orthoses and in-shoe wedges provide during cycling. At present, there is some evidence that during cycling foot orthoses: increase contact area under the foot and increase plantar pressures under the hallux, but provide no gains in power. Based on available evidence, no definitive conclusions can be made about the effects foot orthoses have on lower limb kinematics and oxygen consumption, and the effect in-shoe wedges have on power during cycling. Future well-designed studies on this topic are warranted. PMID:24955129
NASA Astrophysics Data System (ADS)
Arya, Sabha Raj; Patel, Ashish; Giri, Ashutosh
2018-06-01
This paper deals wind energy based power generation system using Permanent Magnet Synchronous Generator (PMSG). It is controlled using advanced enhanced phase-lock loop for power quality features using distribution static compensator to eliminate the harmonics and to provide KVAR compensation as well as load balancing. It also manages rated potential at the point of common interface under linear and non-linear loads. In order to have better efficiency and reliable operation of PMSG driven by wind turbine, it is necessary to analyze the governing equation of wind based turbine and PMSG under fixed and variable wind speed. For handling power quality problems, power electronics based shunt connected custom power device is used in three wire system. The simulations in MATLAB/Simulink environment have been carried out in order to demonstrate this model and control approach used for the power quality enhancement. The performance results show the adequate performance of PMSG based power generation system and control algorithm.
NASA Astrophysics Data System (ADS)
Arya, Sabha Raj; Patel, Ashish; Giri, Ashutosh
2018-03-01
This paper deals wind energy based power generation system using Permanent Magnet Synchronous Generator (PMSG). It is controlled using advanced enhanced phase-lock loop for power quality features using distribution static compensator to eliminate the harmonics and to provide KVAR compensation as well as load balancing. It also manages rated potential at the point of common interface under linear and non-linear loads. In order to have better efficiency and reliable operation of PMSG driven by wind turbine, it is necessary to analyze the governing equation of wind based turbine and PMSG under fixed and variable wind speed. For handling power quality problems, power electronics based shunt connected custom power device is used in three wire system. The simulations in MATLAB/Simulink environment have been carried out in order to demonstrate this model and control approach used for the power quality enhancement. The performance results show the adequate performance of PMSG based power generation system and control algorithm.
Power quality improvement of a stand-alone power system subjected to various disturbances
NASA Astrophysics Data System (ADS)
Lone, Shameem Ahmad; Mufti, Mairaj Ud-Din
In wind-diesel stand-alone power systems, the disturbances like random nature of wind power, turbulent wind, sudden changes in load demand and the wind park disconnection effect continuously the system voltage and frequency. The satisfactory operation of such a system is not an easy task and the control design has to take in to account all these subtleties. For maintaining the power quality, generally, a short-term energy storage device is used. In this paper, the performance of a wind-diesel system associated with a superconducting magnetic energy storage (SMES) system is studied. The effect of installing SMES at wind park bus/load bus, on the system performance is investigated. To control the exchange of real and reactive powers between the SMES unit and the wind-diesel system, a control strategy based on fuzzy logic is proposed. The dynamic models of the hybrid power system for most common scenarios are developed and the results presented.
DOE Office of Scientific and Technical Information (OSTI.GOV)
McHenry, Mark P.; Johnson, Jay; Hightower, Mike
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
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
Conflicting Expertise and Uncertainty: Quality Assurance in High-Level Radioactive Waste Management.
ERIC Educational Resources Information Center
Fitzgerald, Michael R.; McCabe, Amy Snyder
1991-01-01
Dynamics of a large, expensive, and controversial surface and underground evaluation of a radioactive waste management program at the Yucca Mountain power plant are reviewed. The use of private contractors in the quality assurance study complicates the evaluation. This case study illustrates high stakes evaluation problems. (SLD)
NASA Astrophysics Data System (ADS)
Rodríguez-Vidal, E.; Quintana, I.; Etxarri, J.; Otaduy, D.; González, F.; Moreno, F.
2012-06-01
Laser transmission welding (LTW) of polymers is a direct bonding technique which is already used in different industrial applications sectors such as automobile, microfluidic, electronic and biomedicine. This technique offers several advantages over conventional methods, especially when a local deposition of energy and minimum thermal distortions are required. In LTW one of the polymeric materials needs to be transparent to the laser wavelength and the second part needs to be designed to be absorbed in IR spectrum. This report presents a study of laser weldability of ABS (acrylonitrile/butadiene/styrene) filled with two different concentrations of carbon nanotubes (0.01% and 0.05% CNTs). These additives are used as infrared absorbing components in the laser welding process, affecting the thermal and optical properties of the material and, hence, the final quality of the weld seam. A tailored laser system has been designed to obtain high quality weld seams with widths between 0.4 and 1.0mm. It consists of two diode laser bars (50W per bar) coupled into an optical fiber using a non-imaging solution: equalization of the beam quality factor (M2) in the slow and fast axes by a pair of micro step-mirrors. The beam quality factor has been analyzed at different laser powers with the aim to guarantee a coupling efficiency to the multimode optical fiber. The power scaling is carried out by means of multiplexing polarization technique. The analysis of energy balance and beam quality is performed in two linked steps: first by means ray tracing simulations (ZEMAX®) and second, by validation. Quality of the weld seams is analyzed in terms of the process parameters (welding speed, laser power and clamping pressure) by visual and optical microscope inspections. The optimum laser power range for three different welding speeds is determinate meanwhile the clamping pressure is held constant. Additionally, the corresponding mechanical shear tests were carried out to analyze the mechanical properties of the weld seams. This work provides a detailed study concerning the effect of the material microstructure and laser beam quality on the final weld formation and surface integrity.
Research Quality: Critique of Quantitative Articles in the "Journal of Counseling & Development"
ERIC Educational Resources Information Center
Wester, Kelly L.; Borders, L. DiAnne; Boul, Steven; Horton, Evette
2013-01-01
The purpose of this study was to examine the quality of quantitative articles published in the "Journal of Counseling & Development." Quality concerns arose in regard to omissions of psychometric information of instruments, effect sizes, and statistical power. Type VI and II errors were found. Strengths included stated research…
Efficacy of mindfulness meditation for smoking cessation: A systematic review and meta-analysis.
Maglione, Margaret A; Maher, Alicia Ruelaz; Ewing, Brett; Colaiaco, Benjamin; Newberry, Sydne; Kandrack, Ryan; Shanman, Roberta M; Sorbero, Melony E; Hempel, Susanne
2017-06-01
Smokers increasingly seek alternative interventions to assist in cessation or reduction efforts. Mindfulness meditation, which facilitates detached observation and paying attention to the present moment with openness, curiosity, and acceptance, has recently been studied as a smoking cessation intervention. This review synthesizes randomized controlled trials (RCTs) of mindfulness meditation (MM) interventions for smoking cessation. Five electronic databases were searched from inception to October 2016 to identify English-language RCTs evaluating the efficacy and safety of MM interventions for smoking cessation, reduction, or a decrease in nicotine cravings. Two independent reviewers screened literature using predetermined eligibility criteria, abstracted study-level information, and assessed the quality of included studies. Meta-analyses used the Hartung-Knapp-Sidik-Jonkman method for random-effects models. The quality of evidence was assessed using the GRADE approach. Ten RCTs of MM interventions for tobacco use met inclusion criteria. Intervention duration, intensity, and comparison conditions varied considerably. Studies used diverse comparators such as the American Lung Association's Freedom from Smoking (FFS) program, quitline counseling, interactive learning, or treatment as usual (TAU). Only one RCT was rated as good quality and reported power calculations indicating sufficient statistical power. Publication bias was detected. Overall, mindfulness meditation did not have significant effects on abstinence or cigarettes per day, relative to comparator groups. The small number of studies and heterogeneity in interventions, comparators, and outcomes precluded detecting systematic differences between adjunctive and monotherapy interventions. No serious adverse events were reported. MM did not differ significantly from comparator interventions in their effects on tobacco use. Low-quality evidence, variability in study design among the small number of existing studies, and publication bias suggest that additional, high-quality adequately powered RCTs should be conducted. Copyright © 2017 Elsevier Ltd. All rights reserved.
Visual sensitivity of river recreation to power plants
David H. Blau; Michael C. Bowie
1979-01-01
The consultants were asked by the Power Plant Siting Staff of the Minnesota Environmental Quality Council to develop a methodology for evaluating the sensitivity of river-related recreational activities to visual intrusion by large coal-fired power plants. The methodology, which is applicable to any major stream in the state, was developed and tested on a case study...
Using Monte Carlo Simulations to Determine Power and Sample Size for Planned Missing Designs
ERIC Educational Resources Information Center
Schoemann, Alexander M.; Miller, Patrick; Pornprasertmanit, Sunthud; Wu, Wei
2014-01-01
Planned missing data designs allow researchers to increase the amount and quality of data collected in a single study. Unfortunately, the effect of planned missing data designs on power is not straightforward. Under certain conditions using a planned missing design will increase power, whereas in other situations using a planned missing design…
NASA Astrophysics Data System (ADS)
Milood Almelian, Mohamad; Mohd, Izzeldin I.; Asghaiyer Omran, Mohamed; Ullah Sheikh, Usman
2018-04-01
Power quality-related issues such as current and voltage distortions can adversely affect home and industrial appliances. Although several conventional techniques such as the use of passive and active filters have been developed to increase power quality standards, these methods have challenges and are inadequate due to the increasing number of applications. The Unified Power Quality Conditioner (UPQC) is a modern strategy towards correcting the imperfections of voltage and load current supply. A UPQC is a combination of both series and shunt active power filters in a back-to-back manner with a common DC link capacitor. The control of the voltage of the DC link capacitor is important in achieving a desired UPQC performance. In this paper, the UPQC with a Fuzzy logic controller (FLC) was used to precisely eliminate the imperfections of voltage and current harmonics. The results of the simulation studies using MATLAB/Simulink and Simpower system programming for R-L load associated through an uncontrolled bridge rectifier was used to assess the execution process. The UPQC with FLC was simulated for a system with distorted load current and a system with distorted source voltage and load current. The outcome of the comparison of %THD in the load current and source voltage before and after using UPQC for the two cases was presented.
Opportunities for Wind Power In Low- and Mid-Quality Resource Regions
DOE Office of Scientific and Technical Information (OSTI.GOV)
Lantz, Eric; Mai, Trieu; Heimiller, Donna
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.
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.
Bifurcation Analysis of a DC-DC Bidirectional Power Converter Operating with Constant Power Loads
NASA Astrophysics Data System (ADS)
Cristiano, Rony; Pagano, Daniel J.; Benadero, Luis; Ponce, Enrique
Direct current (DC) microgrids (MGs) are an emergent option to satisfy new demands for power quality and integration of renewable resources in electrical distribution systems. This work addresses the large-signal stability analysis of a DC-DC bidirectional converter (DBC) connected to a storage device in an islanding MG. This converter is responsible for controlling the balance of power (load demand and generation) under constant power loads (CPLs). In order to control the DC bus voltage through a DBC, we propose a robust sliding mode control (SMC) based on a washout filter. Dynamical systems techniques are exploited to assess the quality of this switching control strategy. In this sense, a bifurcation analysis is performed to study the nonlinear stability of a reduced model of this system. The appearance of different bifurcations when load parameters and control gains are changed is studied in detail. In the specific case of Teixeira Singularity (TS) bifurcation, some experimental results are provided, confirming the mathematical predictions. Both a deeper insight in the dynamic behavior of the controlled system and valuable design criteria are obtained.
USDA-ARS?s Scientific Manuscript database
This study investigated the physiological and gender determinants of the age-related loss of muscle power in 31 healthy middle-aged adults (aged 40-55 years), 28 healthy older adults (70-85 years) and 34 mobility-limited older adults (70-85 years). We hypothesized that leg extensor muscle power woul...
NASA Technical Reports Server (NTRS)
1979-01-01
The functional, performance, design, and test requirements for the Orbiter power extension package and its associated ground support equipment are defined. Both government and nongovernment standards and specifications are cited for the following subsystems: electrical power, structural/mechanical, avionics, and thermal control. Quality control assurance provisions and preparation for delivery are also discussed.
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.
A study on reliability of power customer in distribution network
NASA Astrophysics Data System (ADS)
Liu, Liyuan; Ouyang, Sen; Chen, Danling; Ma, Shaohua; Wang, Xin
2017-05-01
The existing power supply reliability index system is oriented to power system without considering actual electricity availability in customer side. In addition, it is unable to reflect outage or customer’s equipment shutdown caused by instantaneous interruption and power quality problem. This paper thus makes a systematic study on reliability of power customer. By comparing with power supply reliability, reliability of power customer is defined and extracted its evaluation requirements. An indexes system, consisting of seven customer indexes and two contrast indexes, are designed to describe reliability of power customer from continuity and availability. In order to comprehensively and quantitatively evaluate reliability of power customer in distribution networks, reliability evaluation method is proposed based on improved entropy method and the punishment weighting principle. Practical application has proved that reliability index system and evaluation method for power customer is reasonable and effective.
NASA Astrophysics Data System (ADS)
Kusuma, Chandrakanth; Ahmed, Sazzad H.; Mian, Ahsan; Srinivasan, Raghavan
2017-07-01
Selective laser melting (SLM) is an additive manufacturing technique that creates complex parts by selectively melting metal powder layer-by-layer using a laser. In SLM, the process parameters decide the quality of the fabricated component. In this study, single beads of commercially pure titanium (CP-Ti) were melted on a substrate of the same material using an in-house built SLM machine. Multiple combinations of laser power and scan speed were used for single bead fabrication, while the laser beam diameter and powder layer thickness were kept constant. This experimental study investigated the influence of laser power, scan speed, and laser energy density on the melt pool formation, surface morphology, geometry (width and height), and hardness of solidified beads. In addition, the observed unfavorable effect such as inconsistency in melt pool width formation is discussed. The results show that the quality, geometry, and hardness of solidified melt pool are significantly affected by laser power, scanning speed, and laser energy density.
Modelling voltage sag mitigation using dynamic voltage restorer and analyzing power quality issue
NASA Astrophysics Data System (ADS)
Ismail, Nor Laili; Hidzir, Hizrin Dayana Mohd; Thanakodi, Suresh; Nazar, Nazatul Shiema Moh; Ibrahim, Pungut; Ali, Che Ku Muhammad Sabri Che Ku
2018-02-01
Power quality problem which are arise due to a fault or a pulsed load can have caused an interruption of critical load. The modern power systems are becoming more sensitive to the quality of the power supplied by the utility company. Voltage sags and swells, flicker, interruptions, harmonic distortion and other distortion to the sinusoidal waveform are the examples of the power quality problems. The most affected due to these problems is industrial customers who use a lot of sensitive equipment. There has suffered a huge loss to these problems. Resulting of broken or damage equipment if voltage sag exceeds the sensitive threshold of the equipment. Thus, device such as Static Synchronous Compensator (STATCOM) and Dynamic Voltage Restorer (DVR) has been created to solve this problem among users. DVR is a custom power device that most effective and efficient. This paper intended to report the DVR operations during voltage sag compensation.
The Environmental Impact Study Of Micro Hydro Power In Pekalongan Indonesia
NASA Astrophysics Data System (ADS)
Suwarto; Hadi, Sudharto P.; Hermawan
2018-02-01
Curugmuncar II micro hydro power (MHP) located in Petungkriyono sub district is one of three MHPs installed in Pekalongan district. This study aims to analyze the MHP operation environmental impact. The study used qualitative method, with interviews, observations, and material testing. The data used are primary and secondary data. This research was conducted in Curugmuncar Village, Petungkriyono Subdistrict, Pekalongan Regency, Indonesia. MHP has power capacity of 100 KW with power usage of 50 KW. MHP used by 155 users with load capacity 2 A 220 volt AC. The community more used of lights as the houses and street lighting. The MHP operation had several environmental factors such as: sociology, technically feasible, hydrology, physical and chemical water quality, ergonomics, economically feasible, irrigation, clean water supply, government policy, and others. The supporting factors sustainability of MHP were sociology, irrigation, ergonomics, clean water supply, physical and chemical water quality, hydrology, and government policy. The inhibiting factors of MHP operation were technically feasible, economically feasible, and government policy. The results showed that the MHP environment requires a professional management system to achieve the MHP sustainability
Exploring power and sexual decision making among young Latinos residing in rural communities.
Zukoski, Ann P; Harvey, S Marie; Oakley, Lisa; Branch, Meredith
2011-01-01
Studies of relationship power and sexual decision making related to contraceptive and condom use among Latinos in the United States are limited. This exploratory study provides insight into relationship power and reproductive decision making among a sample of young Latinos (n = 58) who live in rural communities in the Northwest. Using mixed methods approaches, we explored through in-depth interviews how Latino men and women define power, what makes them feel powerful, who has power, and who makes reproductive decisions within their sexual relationships. Descriptions of power and what makes Latinos feel powerful in their relationships reflected more widely accepted definitions and theories with important distinctions. Participants endorsed traditional domains of relationship power describing power as decision-making dominance and relationship control. However, smaller proportions of participants also described power as shared through joint decision making and equality. Themes related to the role of communication and relationship qualities also emerged. Based on quantitative measures, men and women reported that men have more relative power in relationships yet both reported high degrees of power within their own relationships. The majority of women and men believe that both members of a couple participated in decisions to use something to prevent pregnancy and to use condoms. Results underscore that young men and women in new settlement areas have traditional views of power while also identifying equality and interpersonal qualities to be important components of power dynamics within relationships. These findings have important implications for future research and the development of pregnancy and HIV/sexually transmitted infection prevention programs. Copyright © 2011 Jacobs Institute of Women's Health. Published by Elsevier Inc. All rights reserved.
Microwave surface resistance of MgB2
NASA Astrophysics Data System (ADS)
Zhukov, A. A.; Purnell, A.; Miyoshi, Y.; Bugoslavsky, Y.; Lockman, Z.; Berenov, A.; Zhai, H. Y.; Christen, H. M.; Paranthaman, M. P.; Lowndes, D. H.; Jo, M. H.; Blamire, M. G.; Hao, Ling; Gallop, J.; MacManus-Driscoll, J. L.; Cohen, L. F.
2002-04-01
The microwave power and frequency dependence of the surface resistance of MgB2 films and powder samples were studied. Sample quality is relatively easy to identify by the breakdown in the ω2 law for poor-quality samples at all temperatures. The performance of MgB2 at 10 GHz and 21 K was compared directly with that of high-quality YBCO films. The surface resistance of MgB2 was found to be approximately three times higher at low microwave power and showed an onset of nonlinearity at microwave surface fields ten times lower than the YBCO film. It is clear that MgB2 films are not yet optimized for microwave applications.
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.
Straight, Chad R; Brady, Anne O; Evans, Ellen
2015-03-01
This study aims to determine the sex-specific relationships of physical activity, body composition, and muscle quality with lower-extremity physical function in older men and women. Seventy-nine community-dwelling men (n = 39; mean [SD] age, 76.1 [6.2] y; mean [SD] body mass index, 27.3 [3.8] kg/m(2)) and women (n = 40; mean [SD] age, 75.8 [5.5] y; mean [SD] body mass index, 27.0 [3.8] kg/m(2)) were assessed for physical activity via questionnaire, body composition via dual-energy x-ray absorptiometry scanning, leg extension power using the Nottingham power rig, and muscle quality (W/kg; the ratio of leg extension power [W] to lower-body mineral-free lean mass [kg]). A composite measure of physical function was obtained by summing Z scores from the 6-minute walk, 8-ft up-and-go test, and 30-second chair-stand test. As expected, men had significantly greater levels of physical activity, lower adiposity, greater lean mass, higher leg extension power, and greater muscle quality compared with women (all P < 0.05). In linear regression analyses, muscle quality and physical activity were the strongest predictors of lower-extremity physical function in men and independently explained 42% and 29% of the variance, respectively. In women, muscle quality (16%) and percent body fat (12%) were independent predictors after adjustment for covariates. Muscle quality is the strongest predictor of lower-extremity physical function in men and women, but sex impacts the importance of physical activity and adiposity. These findings suggest that older men and women may benefit from different intervention strategies for preventing physical disability and also highlight the importance of weight management for older women to preserve physical function.
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.
Clarks Hill Lake Water Quality Study.
1982-06-01
multipurpose project designed to reduce flooding on the Savannah River, generate electric power and increase the depth of the Savannah River for... power plant at the dam has seven generators, each with a capacity of 40,000 kilowatts. The average annual energy output of Clarks Hill Power Plant is 700...feet) from the top of power pool elevation of 100.6 meters (330 feet msl) to a minimum pool elevation of 95.1 meters (312 feet msl). Because of below
Approach path control for powered-lift STOL aircraft
NASA Technical Reports Server (NTRS)
Clymer, D. J.; Flora, C. C.
1973-01-01
A flight control system concept is defined for approach flightpath control of an augmentor wing (or similar) powered-lift STOL configuration. The proposed STOL control concept produces aircraft transient and steady-state control responses that are familiar to pilots of conventional jet transports, and has potential for good handling qualities ratings in all approach and landing phases. The effects of trailing-edge rate limits, real-engine dynamics, and atmospheric turbulence are considered in the study. A general discussion of STOL handling qualities problems and piloting techniques is included.
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.
Nd:YAG laser welding of coated sheet steel
DOE Office of Scientific and Technical Information (OSTI.GOV)
Graham, M.P.; Kerr, H.W.; Weckman, D.C.
1994-12-31
Coated sheet steels are used extensively in the automotive industry for the fabrication of automobile body components; however, their reduced weldability by the traditional welding processes has led to numerous studies into the use of alternate process such as laser welding. In this paper, we present a modified joint geometry which allows high quality lap welds of coated sheet steels to be made by laser welding processes. Hot-dipped galvanized sheet (16 gauge), with a 60 g/m zinc coating was used in this study. A groove was created in the top sheet of a specimen pair by pressing piano wires ofmore » various diameters into the sheet. The specimens were clamped together in a lag-joint configuration such that they were in contacted only along the grove projection. A parametric study was conducted using the variables of welding speed, laser mean power (685 W, 1000 W and 1350 W), and grove size. Weld quality and weld pool dimensions were assessed using metallurgical cross-sections and image analysis techniques. Acceptable quality seam welds were produced in the galvanized sheet steel with both grove sizes when using 1000 W and 1350 W laser mean powers and a range of welding speeds. Results of the shear-tensile tests showed that high loads to failure, with failure occurring in the parent material, were predominately found in welds produced at speeds over 1.2 m/min and when using the high mean laser powers: 1000 W and 1350 W. A modified lap joint geometry, in which a groove is pre-placed in the top sheet of the lap-joint configuration, has been developed which permits laser welding of coated sheet steels. Good quality seam welds have been produced in 16 gauge galvanized sheet steels at speeds up to 2.7 m/min using a 2 kW CW Nd:YAG laser operating at 1350 W laser mean power. Weld quality was not affected by changes in groove size.« less
Rodríguez, Óscar; Eim, Valeria; Rosselló, Carmen; Femenia, Antoni; Cárcel, Juan A; Simal, Susana
2018-03-01
Drying gives rise to products with a long shelf life by reducing the water activity to a level that is sufficiently low to inhibit the growth of microorganisms, enzymatic reactions and other deteriorative reactions. 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, because of a longer drying time, 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 as 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. Intensification of the drying process with power ultrasound can be achieved by modifying the product behavior during drying, using pre-treatments such as soaking in a liquid medium assisted acoustically or, during the drying process itself, by applying power ultrasound in the gaseous medium. This review summarises the effects of the application of the power ultrasound on the quality of different dried products, such as fruits and vegetables, when the acoustic energy is intended to intensify the drying process, either when the application is performed before pretreatment or during the drying process. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.
USDA-ARS?s Scientific Manuscript database
Previous studies have shown the powered roll gin stand (PRGS) is capable of improving ginning rate, turnout, and fiber quality relative to a conventional gin stand; however, most of these studies used Continental Eagle gin stands, the gin stand used to develop the initial prototype and the one used ...
ERIC Educational Resources Information Center
Mutereko, Sybert
2018-01-01
Using Foucault's power concepts of the panopticon and governmentality as analytic and heuristic tools, this study reveals insights into how accreditation creates power networks in the quality assurance of higher education graduates in South Africa. The study draws on 11 in-depth interviews with academics from the Faculty of Engineering at a…
High-power arrays of quantum cascade laser master-oscillator power-amplifiers.
Rauter, Patrick; Menzel, Stefan; Goyal, Anish K; Wang, Christine A; Sanchez, Antonio; Turner, George; Capasso, Federico
2013-02-25
We report on multi-wavelength arrays of master-oscillator power-amplifier quantum cascade lasers operating at wavelengths between 9.2 and 9.8 μm. All elements of the high-performance array feature longitudinal (spectral) as well as transverse single-mode emission at peak powers between 2.7 and 10 W at room temperature. The performance of two arrays that are based on different seed-section designs is thoroughly studied and compared. High output power and excellent beam quality render the arrays highly suitable for stand-off spectroscopy applications.
Study of aircraft electrical power systems
NASA Technical Reports Server (NTRS)
1972-01-01
The formulation of a philosophy for devising a reliable, efficient, lightweight, and cost effective electrical power system for advanced, large transport aircraft in the 1980 to 1985 time period is discussed. The determination and recommendation for improvements in subsystems and components are also considered. All aspects of the aircraft electrical power system including generation, conversion, distribution, and utilization equipment were considered. Significant research and technology problem areas associated with the development of future power systems are identified. The design categories involved are: (1) safety-reliability, (2) power type, voltage, frequency, quality, and efficiency, (3) power control, and (4) selection of utilization equipment.
Observation and Modeling of the Evolution of Texas Power Plant Plumes
During the second Texas Air Quality Study 2006 (TexAQS II), a full range of pollutants was measured by aircraft in eastern Texas during successive transects of power plant plumes (PPPs). A regional photochemical model is applied to simulate the physical and chemical evolution of ...
On the Control of Air Quality: Why the Laws Don't Work
ERIC Educational Resources Information Center
Goldstein, Paul; Ford, Robert
1973-01-01
Studied implementation of air quality management in two western New York counties by interviewing three enforcement agencies and 30 industrial firms. Concluded that critical problems existed in the transient nature of contaminant emissions and the control of regulatory power by industries. (CC)
Results of the promoting effective advance care planning for elders (PEACE) randomized pilot study.
Radwany, Steven M; Hazelett, Susan E; Allen, Kyle R; Kropp, Denise J; Ertle, Denise; Albanese, Teresa H; Fosnight, Susan M; Moore, Pamela S
2014-04-01
The specific aim of the PEACE pilot study was to determine the feasibility of a fully powered study to test the effectiveness of an in-home geriatrics/palliative care interdisciplinary care management intervention for improving measures of utilization, quality of care, and quality of life in enrollees of Ohio's community-based long-term care Medicaid waiver program, PASSPORT. This was a randomized pilot study (n=40 intervention [IG], n=40 usual care) involving new enrollees into PASSPORT who were >60 years old. This was an in-home interdisciplinary chronic illness care management intervention by PASSPORT care managers collaborating with a hospital-based geriatrics/palliative care specialist team and the consumer's primary care physician. This pilot was not powered to test hypotheses; instead, it was hypothesis generating. Primary outcomes measured symptom control, mood, decision making, spirituality, and quality of life. Little difference was seen in primary outcomes; however, utilization favored the IG. At 12 months, the IG had fewer hospital visits (50% vs. 55%, P=0.65) and fewer nursing facility admissions (22.5% vs. 32.5%, P=0.32). Using hospital-based specialists interfacing with a community agency to provide a team-based approach to care of consumers with chronic illnesses was found to be feasible. Lack of change in symptom control or quality of life outcome measures may be related to the tools used, as these were validated in populations closer to the end of life. Data from this pilot study will be used to calculate the sample size needed for a fully powered trial.
Sample Size in Qualitative Interview Studies: Guided by Information Power.
Malterud, Kirsti; Siersma, Volkert Dirk; Guassora, Ann Dorrit
2015-11-27
Sample sizes must be ascertained in qualitative studies like in quantitative studies but not by the same means. The prevailing concept for sample size in qualitative studies is "saturation." Saturation is closely tied to a specific methodology, and the term is inconsistently applied. We propose the concept "information power" to guide adequate sample size for qualitative studies. Information power indicates that the more information the sample holds, relevant for the actual study, the lower amount of participants is needed. We suggest that the size of a sample with sufficient information power depends on (a) the aim of the study, (b) sample specificity, (c) use of established theory, (d) quality of dialogue, and (e) analysis strategy. We present a model where these elements of information and their relevant dimensions are related to information power. Application of this model in the planning and during data collection of a qualitative study is discussed. © The Author(s) 2015.
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.
Wang, Chunhua; Liu, Chong; Shen, Lifeng; Zhao, Zhiliang; Liu, Bin; Jiang, Hongbo
2016-03-20
In this paper a delicately designed double-passing end-pumped Nd:YVO4 rod amplifier is reported that produces 10.2 W average laser output when seeded by a 6 mW Nd:YVO4 microchip laser at a repetition rate of 70 kHz with pulse duration of 90 ps. A pulse peak power of ∼1.6 MW and pulse energy of ∼143 μJ is achieved. The beam quality is well preserved by a double-passing configuration for spherical-aberration compensation. The laser-beam size in the amplifier is optimized to prevent the unwanted damage from the high pulse peak-power density. This study provides a simple and robust picosecond all-solid-state master oscillator power amplifier system with both high peak power and high beam quality, which shows great potential in the micromachining.
The impact of turbulent renewable energy production on power grid stability and quality
NASA Astrophysics Data System (ADS)
Schmietendorf, Katrin; Peinke, Joachim; Kamps, Oliver
2017-11-01
Feed-in fluctuations induced by renewables are one of the key challenges to the stability and quality of electrical power grids. In particular short-term fluctuations disturb the system on a time scale, on which load balancing does not operate yet and the system is intrinsically governed by self-organized synchronization. Wind and solar power are known to be strongly non-Gaussian with intermittent increment statistics in these time scales. We investigate the impact of short-term wind fluctuations on the basis of a Kuramoto-like power grid model considering stability in terms of desynchronization and frequency and voltage quality aspects. We present a procedure to generate realistic feed-in fluctuations with temporal correlations, Kolmogorov power spectrum and intermittent increments. By comparison to correlated Gaussian noise of the same spectrum and Gaussian white noise, we found out that while the correlations are essential to capture the likelihood of severe outages, the intermittent nature of wind power has significant consequences on power quality: intermittency is directly transferred into frequency and voltage fluctuations yielding a novel type of fluctuations, which is beyond engineering status of knowledge.
Flight simulator for hypersonic vehicle and a study of NASP handling qualities
NASA Technical Reports Server (NTRS)
Ntuen, Celestine A.; Park, Eui H.; Deeb, Joseph M.; Kim, Jung H.
1992-01-01
The research goal of the Human-Machine Systems Engineering Group was to study the existing handling quality studies in aircraft with sonic to supersonic speeds and power in order to understand information requirements needed for a hypersonic vehicle flight simulator. This goal falls within the NASA task statements: (1) develop flight simulator for hypersonic vehicle; (2) study NASP handling qualities; and (3) study effects of flexibility on handling qualities and on control system performance. Following the above statement of work, the group has developed three research strategies. These are: (1) to study existing handling quality studies and the associated aircraft and develop flight simulation data characterization; (2) to develop a profile for flight simulation data acquisition based on objective statement no. 1 above; and (3) to develop a simulator and an embedded expert system platform which can be used in handling quality experiments for hypersonic aircraft/flight simulation training.
NASA Astrophysics Data System (ADS)
Ahmadi, A.; Avazpour, A.; Nadgaran, H.; Mousavi, M.
2018-04-01
The effect of terbium gallium garnet (TGG ) crystal length on 1064 and 532 nm output powers and beam quality of a unidirectional ring Nd:YVO4 laser is investigated. In the case of 1064 nm (without nonlinear crystal), the laser output power without considerating the effect of TGG crystal was computed theoretically. Then three TGG crystals with different lengths were placed in the laser setup one by one. A systematic decrease in output power was observed by increasing the TGG crystal length. The experiment was repeated in the case of 532 nm. It was found that in a 532 nm laser, higher laser efficiency and small beam quality degradation can be achieved by increasing the TGG crystal length leading to a 5.7 W green laser with 27 W pump power. The power stability and beam quality were 0.8% for 30 min and less than 1.3, respectively.
Theoretical Investigation For The Effect of Fuel Quality on Gas Turbine Power Plants
NASA Astrophysics Data System (ADS)
AbdulRazzak khudair, Omar; Alwan Abass, Khetam; Saadi Abed, Noor; Hussain Ali, Khalid; AbdulAziz, Saad; Chlaib Shaboot, Ali
2018-05-01
Gas turbine engine power generation is declined dramatically because of the reduction in thermodynamic parameters as a work of turbine, compressor ratio, compressor work, and air mass flow rate and fuel consumption. There are two main objectives of this work, the first is related with the effect of fuel kinds and their quality on the operation of fuel flow divider and its performance specifically gear pump displacement and fuel flow rate to the combustion chambers of gas power plant. AL-DORA gas turbine power plant 35MW was chosen to predict these effects on its performance MATLAB Software program is used to perform thermodynamic calculations. Fuel distribution stage before the process of combustion and as a result of the kind and its quality, chemical reaction will occur between the fuel and the parts of the gear system of each pump of the flow divider, which causes the erosion of the internal pump wall and the teeth of the gear system, thus hampering the pump operation in terms of fuel discharge. The discharge of fuel form the eight external gates of flow divider is decreased and varied when going to the combustion chambers, so that, flow divider does not give reliable mass flow rate due to absence of accurate pressure in each of eight exit pipes. The second objective deals with the stage of fuel combustion process inside the combustion chamber. A comparative study based upon performance parameters, such as specific fuel consumption for gas and gasoil and power generation. Fuel poor quality causes incomplete combustion and increased its consumption, so that combustion products are interacted with the surface of the turbine blades, causing the erosion and create surface roughness of the blade and disruption of gas flow. As a result of this situation, turbulence flow of these gases will increase causing the separation of gas boundary layers over the suction surface of the blade. Therefore the amount of extracted gas will decrease causing retreat work done by turbine, as a result decline of power and gas turbine power plant efficiency causing the drop in the level of electric generation. The fuel quality is found to be a strong function of specific fuel consumption and its effects on the power generation and the efficiency of the gas turbine power plants and hence, the cycle performance shifts towards favorable conditions.
Multi-Channel, Constant-Current Power Source for Aircraft Applications
2017-03-01
Special considerations impacting this design were minimizing volume, maintaining system power quality, and providing electrical fault protection...applications. Electrical loads, such as lighting, de-icing heaters, and actuators may be operated from this compact power conversion unit. Because of the...nature of aircraft systems, two of the most important design considerations are the maintenance of electrical power quality and minimization of weight
Fu, Zhenghui; Wang, Han; Lu, Wentao; Guo, Huaicheng; Li, Wei
2017-12-01
Electric power system involves different fields and disciplines which addressed the economic system, energy system, and environment system. Inner uncertainty of this compound system would be an inevitable problem. Therefore, an inexact multistage fuzzy-stochastic programming (IMFSP) was developed for regional electric power system management constrained by environmental quality. A model which concluded interval-parameter programming, multistage stochastic programming, and fuzzy probability distribution was built to reflect the uncertain information and dynamic variation in the case study, and the scenarios under different credibility degrees were considered. For all scenarios under consideration, corrective actions were allowed to be taken dynamically in accordance with the pre-regulated policies and the uncertainties in reality. The results suggest that the methodology is applicable to handle the uncertainty of regional electric power management systems and help the decision makers to establish an effective development plan.
NASA Astrophysics Data System (ADS)
Kota, Venkata Reddy; Vinnakoti, Sudheer
2017-12-01
Today, maintaining Power Quality (PQ) is very important in the growing competent world. With new equipments and devices, new challenges are also being put before power system operators. Unified Power Quality Conditioner (UPQC) is proposed to mitigate many power quality problems and to improve the performance of the power system. In this paper, an UPQC with Fuzzy Logic controller for capacitor voltage balancing is proposed in Synchronous Reference Frame (SRF) based control with Modified Phased Locked Loop (MPLL). The proposed controller with SRF-MPLL based control is tested under non-linear and unbalanced load conditions. The system is developed in Matlab/Simulink and its performance is analyzed under various conditions like non-linear, unbalanced load and polluted supply voltage including voltage sag/swells. Active and reactive power flow in the system, power factor and %THD of voltages and currents before and after compensation are also analyzed in this work. Results prove the applicability of the proposed scheme for power quality improvement. It is observed that the fuzzy controller gives better performance than PI controller with faster capacitor voltage balancing and also improves the dynamic performance of the system.
NASA Astrophysics Data System (ADS)
Sondkar, Pravin B.
The severity of combined aerodynamics and power transmission response in high-speed, high power density systems such as a rotorcraft is still a major cause of annoyance in spite of recent advancement in passive, semi-active and active control. With further increase in the capacity and power of this class of machinery systems, the acoustic noise levels are expected to increase even more. To achieve further improvements in sound quality, a more refined understanding of the factors and attributes controlling human perception is needed. In the case of rotorcraft systems, the perceived quality of the interior sound field is a major determining factor of passenger comfort. Traditionally, this sound quality factor is determined by measuring the response of a chosen set of juries who are asked to compare their qualitative reactions to two or more sounds based on their subjective impressions. This type of testing is very time-consuming, costly, often inconsistent, and not useful for practical design purposes. Furthermore, there is no known universal model for sound quality. The primary aim of this research is to achieve significant improvements in quantifying the sound quality of combined aerodynamic and power transmission response in high-speed, high power density machinery systems such as a rotorcraft by applying relevant objective measures related to the spectral characteristics of the sound field. Two models have been proposed in this dissertation research. First, a classical multivariate regression analysis model based on currently known sound quality metrics as well some new metrics derived in this study is presented. Even though the analysis resulted in the best possible multivariate model as a measure of the acoustic noise quality, it lacks incorporation of human judgment mechanism. The regression model can change depending on specific application, nature of the sounds and types of juries used in the study. Also, it predicts only the averaged preference scores and does not explain why two jury members differ in their judgment. To address the above shortcoming of applying regression analysis, a new human judgment model is proposed to further improve the ability to predict the degree of subjective annoyance. The human judgment model involves extraction of subjective attributes and their values using a proposed artificial jury processor. In this approach, a set of ear transfer functions are employed to compute the characteristics of sound pressure waves as perceived subjectively by human. The resulting basilar membrane displacement data from this proposed model is then applied to analyze the attribute values. Using this proposed human judgment model, the human judgment mechanism, which is highly sophisticated, will be examined. Since the human judgment model is essentially based on jury attributes that are not expected to change significantly with application or nature of the sound field, it gives a more common basis to evaluate sound quality. This model also attempts to explain the inter-juror differences in opinion, which is critical in understanding the variability in human response.
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.
Influence of fundamental mode fill factor on disk laser output power and laser beam quality
NASA Astrophysics Data System (ADS)
Cheng, Zhiyong; Yang, Zhuo; Shao, Xichun; Li, Wei; Zhu, Mengzhen
2017-11-01
An three-dimensional numerical model based on finite element method and Fox-Li method with angular spectrum diffraction theoy is developed to calculate the output power and power density distribution of Yb:YAG disk laser. We invest the influence of fundamental mode fill factor(the ratio of fundamental mode size and pump spot size) on the output power and laser beam quality. Due to aspherical aberration and soft aperture effect in laser disk, high beam quality can be achieve with relative lower efficiency. The highest output power of fundamental laser mode is influenced by the fundamental mode fill factor. Besides we find that optimal mode fill factor increase with pump spot size.
McDonald, Sandra A; Mardis, Elaine R; Ota, David; Watson, Mark A; Pfeifer, John D; Green, Jonathan M
2012-07-01
As part of the molecular revolution sweeping medicine, comprehensive genomic studies are adding powerful dimensions to medical research. However, their power exposes new regulatory, strategic, and quality assurance challenges for biorepositories. A key issue is that unlike other research techniques commonly applied to banked specimens, nucleic acid sequencing, if sufficiently extensive, yields data that could identify a patient. This evolving paradigm renders the concepts of anonymized and anonymous specimens increasingly outdated. The challenges for biorepositories in this new era include refined consent processes and wording, selection and use of legacy specimens, quality assurance procedures, institutional documentation, data sharing, and interaction with institutional review boards. Given current trends, biorepositories should consider these issues now, even if they are not currently experiencing sample requests for genomic analysis. We summarize our current experiences and best practices at Washington University Medical School, St Louis, MO, our perceptions of emerging trends, and recommendations.
McDonald, Sandra A.; Mardis, Elaine R.; Ota, David; Watson, Mark A.; Pfeifer, John D.; Green, Jonathan M.
2012-01-01
As part of the molecular revolution sweeping medicine, comprehensive genomic studies are adding powerful dimensions to medical research. However, their power exposes new regulatory, strategic, and quality assurance challenges for biorepositories. A key issue is that unlike other research techniques commonly applied to banked specimens, nucleic acid sequencing, if sufficiently extensive, yields data that could identify a patient. This evolving paradigm renders the concepts of anonymized and anonymous specimens increasingly outdated. The challenges for biorepositories in this new era include refined consent processes and wording, selection and use of legacy specimens, quality assurance procedures, institutional documentation, data sharing, and interaction with institutional review boards. Given current trends, biorepositories should consider these issues now, even if they are not currently experiencing sample requests for genomic analysis. We summarize our current experiences and best practices at Washington University Medical School, St Louis, MO, our perceptions of emerging trends, and recommendations. PMID:22706855
Ramachandran, Amar; Kumar, Pratap
2015-01-01
Introduction The parent oocyte from which the embryo is derived, determines its quality and the perifollicular vascularity (PFV) determines the micro-environment of the developing ovum. The PFV correlates well with the follicular oxygenation, oocyte maturation and embryo viability. PFV is imaged with Power Doppler Ultrasound. Aim To study and compare the association of the PFV of follicles with the quality of the oocytes and embryos in agonist and antagonist protocol, employed in Assisted Reproductive techniques (ART). Study Design A prospective observational study was conducted on 75 patients, who were recruited for ART cycles, out of which 25 were given the Agonist protocol and the remaining 50 received the Antagonist protocol. Materials and Methods The patients underwent the stimulation protocol. The PFV of preovulatory follicles were studied with Transvaginal Power Doppler and graded. Each oocyte retrieved carried the same label of its parent follicle. Embryos were cultured. The embryologist was blinded. The oocyte and embryo quality were assessed and compared with the PFV of parent follicle. Results Follicles with grade 1 and 2 PFV were predominantly observed. The yield of oocytes was independent of PFV. The mean yield of good quality embryos in conjunction with the PFV of the parent follicle was found to be highly significant in both the groups. The antagonist group had statistically significant yield of mature oocytes and embryos, compared to the agonist group. Conclusion Antagonist protocol had favourable outcomes compared with the agonist protocol. The retrieval of oocytes, even the mature ones and the yield of high grade embryos were found higher. As the PFV increased, the yield and overall pregnancy rates were higher. PFV as assessed by Power Doppler is a useful non-invasive biomarker of embryo quality and can be employed in conjunction with other biomarkers in ART to predict successful outcome. PMID:26674932
Optimization of light quality from color mixing light-emitting diode systems for general lighting
NASA Astrophysics Data System (ADS)
Thorseth, Anders
2012-03-01
Given the problem of metamerisms inherent in color mixing in light-emitting diode (LED) systems with more than three distinct colors, a method for optimizing the spectral output of multicolor LED system with regards to standardized light quality parameters has been developed. The composite spectral power distribution from the LEDs are simulated using spectral radiometric measurements of single commercially available LEDs for varying input power, to account for the efficiency droop and other non-linear effects in electrical power vs. light output. The method uses electrical input powers as input parameters in a randomized steepest decent optimization. The resulting spectral power distributions are evaluated with regard to the light quality using the standard characteristics: CIE color rendering index, correlated color temperature and chromaticity distance. The results indicate Pareto optimal boundaries for each system, mapping the capabilities of the simulated lighting systems with regard to the light quality characteristics.
Kim, Byeong-Uk; Kim, Okgil; Kim, Hyun Cheol; Kim, Soontae
2016-09-01
The South Korean government plans to reduce region-wide annual PM2.5 (particulate matter with an aerodynamic diameter ≤2.5 μm) concentrations in the Seoul Capital Area (SCA) from 2010 levels of 27 µg/m(3) to 20 µg/m(3) by 2024. At the same time, it is inevitable that emissions from fossil-fuel power plants will continue to increase if electricity generation expands and the generation portfolio remains the same in the future. To estimate incremental PM2.5 contributions due to projected electricity generation growth in South Korea, we utilized an ensemble forecasting member of the Integrated Multidimensional Air Quality System for Korea based on the Community Multi-scale Air Quality model. We performed sensitivity runs with across-the-board emission reductions for all fossil-fuel power plants in South Korea to estimate the contribution of PM2.5 from domestic fossil-fuel power plants. We estimated that fossil-fuel power plants are responsible for 2.4% of the annual PM2.5 national ambient air quality standard in the SCA as of 2010. Based on the electricity generation and the annual contribution of fossil-fuel power plants in 2010, we estimated that annual PM2.5 concentrations may increase by 0.2 µg/m(3) per 100 TWhr due to additional electricity generation. With currently available information on future electricity demands, we estimated that the total future contribution of fossil-fuel power plants would be 0.87 µg/m(3), which is 12.4% of the target reduction amount of the annual PM2.5 concentration by 2024. We also approximated that the number of premature deaths caused by existing fossil-fuel power plants would be 736 in 2024. Since the proximity of power plants to the SCA and the types of fuel used significantly impact this estimation, further studies are warranted on the impact of physical parameters of plants, such as location and stack height, on PM2.5 concentrations in the SCA due to each precursor. Improving air quality by reducing fine particle pollution is challenging when fossil-fuel-based electricity production is increasing. We show that an air quality forecasting system based on a photochemical model can be utilized to efficiently estimate PM2.5 contributions from and health impacts of domestic power plants. We derived PM2.5 concentrations per unit amount of electricity production from existing fossil-fuel power plants in South Korea. We assessed the health impacts of existing fossil-fuel power plants and the PM2.5 concentrations per unit electricity production to quantify the significance of existing and future fossil-fuel power plants with respect to the planned PM2.5 reduction target.
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
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%.
NASA Astrophysics Data System (ADS)
Irawati, Rina
2018-02-01
Diesel Generator with Photovoltaic Hybrid Power Plant is one of the solutions for supply electric demand to isolated area. The energy sources that can be used for hybrid system are such as photovoltaic, wind turbine, and biomass or biogas, because these sources are almost available in every isolated area. This research used a model of hybrid system from diesel generator and 1.28 kWp photovoltaic power plant. The reliability and some of power quality of this system tested by 1300VA house hold daily load characteristic effectively 24 hour. Power quality and some electricity parameters during transition mode for each resource will be analyzed. Furthermore the power quality analyze will be conducted and evaluated base on Electrical Engineers' Association (EEA).
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... LICENSING OF PRODUCTION AND UTILIZATION FACILITIES Pt. 50, App. B Appendix B to Part 50—Quality Assurance... report a description of the quality assurance program to be applied to the design, fabrication...
Analysis instrument test on mathematical power the material geometry of space flat side for grade 8
NASA Astrophysics Data System (ADS)
Kusmaryono, Imam; Suyitno, Hardi; Dwijanto, Karomah, Nur
2017-08-01
The main problem of research to determine the quality of test items on the material side of flat geometry to assess students' mathematical power. The method used is quantitative descriptive. The subjects were students of class 8 as many as 20 students. The object of research is the quality of test items in terms of the power of mathematics: validity, reliability, level of difficulty and power differentiator. Instrument mathematical power ratings are tested include: written tests and questionnaires about the disposition of mathematical power. Data were obtained from the field, in the form of test data on the material geometry of space flat side and questionnaires. The results of the test instrument to the reliability of the test item is influenced by many factors. Factors affecting the reliability of the instrument is the number of items, homogeneity test questions, the time required, the uniformity of conditions of the test taker, the homogeneity of the group, the variability problem, and motivation of the individual (person taking the test). Overall, the evaluation results of this study stated that the test instrument can be used as a tool to measure students' mathematical power.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Tang, Yingying; Homer, Juliet S.; McDermott, Thomas E.
The purpose of this document is to summarize types of electric distribution system analyses along with their application and relative maturity. Particular emphasis is placed on analyses associated with distributed energy resources (DERs). Analyses are separated into the categories of power flow, power quality, fault analysis, dynamic analysis and market analysis. Studies associated with DERs are called out in a separate section.
Sex, Grades and Power in Higher Education in Ghana and Tanzania
ERIC Educational Resources Information Center
Morley, Louise
2011-01-01
Quantitative increases tell a partial story about the quality of women's participation in higher education. Women students' reporting of sexual harassment has been noteworthy in a recent study that I directed on widening participation in higher education in Ghana and Tanzania. The hierarchical and gendered power relations within universities have…
NASA Technical Reports Server (NTRS)
1979-01-01
Contractor information requirements necessary to support the power extension package project of the space shuttle program are specified for the following categories of data: project management; configuration management; systems engineering and test; manufacturing; reliability, quality assurance and safety; logistics; training; and operations.
Powerful Learning Experiences and Suzuki Music Teachers
ERIC Educational Resources Information Center
Reuning-Hummel, Carrie; Meyer, Allison; Rowland, Gordon
2016-01-01
Powerful Learning Experiences (PLEs) of Suzuki music teachers were examined in this fifth study in a series. The definition of a PLE is: "Experiences that stand out in memory because of their high quality, their impact on one's thoughts and actions over time, and their transfer to a wide range of contexts and circumstances." Ten…
Personalization Versus Customization: The Importance of Agency, Privacy, and Power Usage
ERIC Educational Resources Information Center
Sundar, S. Shyam; Marathe, Sampada S.
2010-01-01
What makes customization so appealing? Is it because the content is tailored or because the user feels greater agency? Study 1 tested these propositions with a news-aggregator Website that was either personalized (system-tailored), customized (user-tailored), or neither. Power users rated content quality higher when it had a customizable…
High speed micromachining with high power UV laser
NASA Astrophysics Data System (ADS)
Patel, Rajesh S.; Bovatsek, James M.
2013-03-01
Increasing demand for creating fine features with high accuracy in manufacturing of electronic mobile devices has fueled growth for lasers in manufacturing. High power, high repetition rate ultraviolet (UV) lasers provide an opportunity to implement a cost effective high quality, high throughput micromachining process in a 24/7 manufacturing environment. The energy available per pulse and the pulse repetition frequency (PRF) of diode pumped solid state (DPSS) nanosecond UV lasers have increased steadily over the years. Efficient use of the available energy from a laser is important to generate accurate fine features at a high speed with high quality. To achieve maximum material removal and minimal thermal damage for any laser micromachining application, use of the optimal process parameters including energy density or fluence (J/cm2), pulse width, and repetition rate is important. In this study we present a new high power, high PRF QuasarR 355-40 laser from Spectra-Physics with TimeShiftTM technology for unique software adjustable pulse width, pulse splitting, and pulse shaping capabilities. The benefits of these features for micromachining include improved throughput and quality. Specific example and results of silicon scribing are described to demonstrate the processing benefits of the Quasar's available power, PRF, and TimeShift technology.
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.
Fuel cells provide a revenue-generating solution to power quality problems
DOE Office of Scientific and Technical Information (OSTI.GOV)
King, J.M. Jr.
Electric power quality and reliability are becoming increasingly important as computers and microprocessors assume a larger role in commercial, health care and industrial buildings and processes. At the same time, constraints on transmission and distribution of power from central stations are making local areas vulnerable to low voltage, load addition limitations, power quality and power reliability problems. Many customers currently utilize some form of premium power in the form of standby generators and/or UPS systems. These include customers where continuous power is required because of health and safety or security reasons (hospitals, nursing homes, places of public assembly, air trafficmore » control, military installations, telecommunications, etc.) These also include customers with industrial or commercial processes which can`t tolerance an interruption of power because of product loss or equipment damage. The paper discusses the use of the PC25 fuel cell power plant for backup and parallel power supplies for critical industrial applications. Several PC25 installations are described: the use of propane in a PC25; the use by rural cooperatives; and a demonstration of PC25 technology using landfill gas.« less
The influence of utility-interactive PV system characteristics to ac power networks
NASA Astrophysics Data System (ADS)
Takeda, Y.; Takigawa, K.; Kaminosono, H.
Two basic experimental photovoltaic (PV) systems have been built for the study of variation of power quality, aspects of safety, and technical problems. One system uses a line-commutated inverter, while the other system uses a self-commutated inverter. A description is presented of the operating and generating characteristics of the two systems. The systems were connected to an ac simulated network which simulates an actual power distribution system. Attention is given to power generation characteristics, the control characteristics, the harmonics characteristics, aspects of coordination with the power network, and questions regarding the reliability of photovoltaic modules.
Code of Federal Regulations, 2011 CFR
2011-04-01
... 18 Conservation of Power and Water Resources 2 2011-04-01 2011-04-01 false Water quality. 801.7 Section 801.7 Conservation of Power and Water Resources SUSQUEHANNA RIVER BASIN COMMISSION GENERAL POLICIES § 801.7 Water quality. (a) The signatory States have the primary responsibility in the basin for...
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.…
Code of Federal Regulations, 2014 CFR
2014-04-01
... 18 Conservation of Power and Water Resources 2 2014-04-01 2014-04-01 false Water quality. 801.7 Section 801.7 Conservation of Power and Water Resources SUSQUEHANNA RIVER BASIN COMMISSION GENERAL POLICIES § 801.7 Water quality. (a) The signatory States have the primary responsibility in the basin for...
Code of Federal Regulations, 2012 CFR
2012-04-01
... 18 Conservation of Power and Water Resources 2 2012-04-01 2012-04-01 false Water quality. 801.7 Section 801.7 Conservation of Power and Water Resources SUSQUEHANNA RIVER BASIN COMMISSION GENERAL POLICIES § 801.7 Water quality. (a) The signatory States have the primary responsibility in the basin for...
Code of Federal Regulations, 2013 CFR
2013-04-01
... 18 Conservation of Power and Water Resources 2 2013-04-01 2012-04-01 true Water quality. 801.7 Section 801.7 Conservation of Power and Water Resources SUSQUEHANNA RIVER BASIN COMMISSION GENERAL POLICIES § 801.7 Water quality. (a) The signatory States have the primary responsibility in the basin for...
Effects of evolving quality of landfill leachate on microbial fuel cell performance.
Li, Simeng; Chen, Gang
2018-01-01
Microbial fuel cell (MFC) is a novel technology for landfill leachate treatment with simultaneous electric power generation. In recent years, more and more modern landfills are operating as bioreactors to shorten the time required for landfill stabilization and improve the leachate quality. For landfills to operate as biofilters, leachate is recirculated back to the landfill, during which time the organics of the leachate can be decomposed. Continuous recirculation typically results in evolving leachate quality, which chronologically corresponds to evolution stages such as hydrolysis, acidogenesis, acetogenesis, methanogenesis, and maturation. In this research, variable power generation (160 to 230 mW m -2 ) by MFC was observed when leachate of various evolutionary stages was used as the feed. The power density followed a Monod-type kinetic model with the chemical oxygen demand (COD) equivalent of the volatile fatty acids (VFAs) ( p < 0.001). The coulombic efficiency decreased from 20% to 14% as the leachate evolved towards maturation. The maximum power density linearly decreased with the increase of internal resistance, resulting from the change of the conductivity of the solution. The decreased conductivity boosted the internal resistance and consequently limited the power generation. COD removal as high as 90% could be achieved with leachate extracted from appropriate evolutionary stages, with a maximum energy yield of 0.9 kWh m -3 of leachate. This study demonstrated the importance of the evolving leachate quality in different evolutionary stages for the performance of leachate-fed MFCs. The leachate extracted from acidogenesis and acetogenesis were optimal for both COD reduction and energy production in MFCs.
Zaenker, Pierre; Favret, Fabrice; Lonsdorfer, Evelyne; Muff, Guillaume; de Seze, Jérôme; Isner-Horobeti, Marie-Eve
2018-02-01
Numerous studies have shown that mild-to-moderate intensity or resistance exercise training improves physical capacities such as, peak oxygen consumption, maximal tolerated power and strength in multiple sclerosis patients. However, few studies have evaluated the effects of high-intensity interval training (HIIT) associated to with resistance training. Only few studies have analyzed difference between men and women before and after combined training. Moreover, the evaluation of exercise between ambulatory multiple sclerosis patients without disability (Expanded Disability Status Score [EDSS] 0-3) and patients with disabilities (EDSS 3.5-5) was not largely published. The main objective of our study was to determine if HIIT combined with resistance training improved aerobic and strength capacities as well as quality of life in multiple sclerosis patients and if gender and disabilities play a role in these changes. This study was an open-label uncontrolled study. The study was performed outside from conventional care facilities and including homebased training. Twenty-six multiple sclerosis patients have completed the program (19 women, 7 men; mean age 44.6±7.9 years, EDSS 2 [0-5]). We conducted a 12-week program of high-intensity interval training combined with resistance training at body weight. Peak oxygen consumption, maximal tolerated power, lactates, isokinetic strength of quadriceps and hamstrings (at 90°/s, 180°/s, and 240°/s) and quality of life were evaluated before and after the program. Peak oxygen consumption and maximum tolerated power improved by 13.5% and 9.4%, respectively. Isokinetic muscle strength increased in both quadriceps and hamstrings at each speed, with a rebalancing of strength between the two legs in quadriceps. Quality of life was also enhanced in three domains. Women showed better improvements than men in V̇O2peak, maximal tolerated power, lactates at the end of test, and heart rate peak, strength in both quadriceps and hamstrings mostly at low speed, and quality of life. The two EDSS groups increased V̇O2peak and strength. Our study has shown that HIIT combined with resistance exercise training induced an improvement in physical capacity and quality of life. Moreover, this study allowed patients, irrespective of their sex or EDSS score, to resume exercise autonomously. The results of the study showed that aerobic training at moderate intensity is not the single type of training tolerated by multiple sclerosis patients. High-intensity interval training is well tolerated too and can be used in clinical rehabilitation with resistance training, in both men and women with and without disabilities.
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.
Development of high-average-power DPSSL with high beam quality
NASA Astrophysics Data System (ADS)
Nakai, Sadao; Kanabe, Tadashi; Kawashima, Toshiyuki; Yamanaka, Masanobu; Izawa, Yasukazu; Nakatuka, Masahiro; Kandasamy, Ranganathan; Kan, Hirofumi; Hiruma, Teruo; Niino, Masayuki
2000-08-01
The recent progress of high power diode laser is opening new fields of laser and its application. We are developing high average power diode pumped solid state laser DPSSL for laser fusion power plant, for space propulsion and for various applications in industry. The common features or requirements of our High Average-power Laser for Nuclear-fusion Application (HALNA) are large pulse energy with relatively low repetition of few tens Hz, good beam quality of order of diffraction limit and high efficiency more than 10%. We constructed HALNA 10 (10J X 10 Hz) and tested the performance to clarify the scalability to higher power system. We have obtained in a preliminary experiment a 8.5 J output energy at 0.5 Hz with beam quality of 2 times diffraction limited far-field pattern.
NASA Technical Reports Server (NTRS)
Lichtenstein, J. H.
1975-01-01
Power-spectral-density calculations were made of the lateral responses to atmospheric turbulence for several conventional and short take-off and landing (STOL) airplanes. The turbulence was modeled as three orthogonal velocity components, which were uncorrelated, and each was represented with a one-dimensional power spectrum. Power spectral densities were computed for displacements, rates, and accelerations in roll, yaw, and sideslip. In addition, the power spectral density of the transverse acceleration was computed. Evaluation of ride quality based on a specific ride quality criterion was also made. The results show that the STOL airplanes generally had larger values for the rate and acceleration power spectra (and, consequently, larger corresponding root-mean-square values) than the conventional airplanes. The ride quality criterion gave poorer ratings to the STOL airplanes than to the conventional airplanes.
Polarized millijoule fiber laser system with high beam quality and pulse shaping ability
NASA Astrophysics Data System (ADS)
Zhang, Rui; Tian, Xiaocheng; Xu, Dangpeng; Zhou, Dandan; Zong, Zhaoyu; Li, Hongxun; Fan, Mengqiu; Huang, Zhihua; Zhu, Na; Su, Jingqin; Zhu, Qihua; Jing, Feng
2017-05-01
The coherent amplification network (CAN) aims at developing a laser system based on the coherent combination of multiple laser beams, which are produced through a network of high beam quality optical fiber amplifiers. The scalability of the CAN laser facilitates the development of many novel applications, such as fiber-based acceleration, orbital debris removal and inertial confinement fusion energy. According to the requirements of CAN and the front end of high-power laser facilities, a millijoule polarized fiber laser system was studied in this paper. Using polarization maintaining Ytterbium-fiber laser system as the seed, and 10-μm core Yb-doped fiber amplifier as the first power amplifier and 40-μm core polarizing (PZ) photonic crystal fiber (PCF) as the second power amplifier, the all-fiber laser system outputs 1.06-mJ energy at 10 ns and diffraction limited mode quality. Using 85-μm rod-type PCF as the third power amplifiers, 2.5-mJ energy at 10-ns pulse width was obtained with better than 500:1 peak-to-foot pulse shaping ability and fundamental mode beam quality. The energy fluctuation of the system is 1.3% rms with 1-mJ output in one hour. When using phase-modulated pulse as the seed, the frequency modulation to amplitude modulation (FM-to-AM) conversion ratio of the system is better than 5%. This fiber laser system has the advantages of high beam quality, high beam shaping ability, good stability, small volume and free of maintenance, which can be used in many applications.
NASA Astrophysics Data System (ADS)
Singh, Yashi; Hussain, Ikhlaq; Singh, Bhim; Mishra, Sukumar
2018-06-01
In this paper, power quality features such as harmonics mitigation, power factor correction with active power filtering are addressed in a single-stage, single-phase solar photovoltaic (PV) grid tied system. The Power Balance Theory (PBT) with perturb and observe based maximum power point tracking algorithm is proposed for the mitigation of power quality problems in a solar PV grid tied system. The solar PV array is interfaced to a single phase AC grid through a Voltage Source Converter (VSC), which provides active power flow from a solar PV array to the grid as well as to the load and it performs harmonics mitigation using PBT based control. The solar PV array power varies with sunlight and due to this, the solar PV grid tied VSC works only 8-10 h per day. At night, when PV power is zero, the VSC works as an active power filter for power quality improvement, and the load active power is delivered by the grid to the load connected at the point of common coupling. This increases the effective utilization of a VSC. The system is modelled and simulated using MATLAB and simulated responses of the system at nonlinear loads and varying environmental conditions are also validated experimentally on a prototype developed in the laboratory.
NASA Astrophysics Data System (ADS)
Singh, Yashi; Hussain, Ikhlaq; Singh, Bhim; Mishra, Sukumar
2018-03-01
In this paper, power quality features such as harmonics mitigation, power factor correction with active power filtering are addressed in a single-stage, single-phase solar photovoltaic (PV) grid tied system. The Power Balance Theory (PBT) with perturb and observe based maximum power point tracking algorithm is proposed for the mitigation of power quality problems in a solar PV grid tied system. The solar PV array is interfaced to a single phase AC grid through a Voltage Source Converter (VSC), which provides active power flow from a solar PV array to the grid as well as to the load and it performs harmonics mitigation using PBT based control. The solar PV array power varies with sunlight and due to this, the solar PV grid tied VSC works only 8-10 h per day. At night, when PV power is zero, the VSC works as an active power filter for power quality improvement, and the load active power is delivered by the grid to the load connected at the point of common coupling. This increases the effective utilization of a VSC. The system is modelled and simulated using MATLAB and simulated responses of the system at nonlinear loads and varying environmental conditions are also validated experimentally on a prototype developed in the laboratory.
Comparative Study of Standards for Grid-Connected Wind Power Plant in China and the U.S.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Gao, Wenzhong; Tian, Tian; Muljadi, Eduard
2015-10-06
The rapid deployment of wind power has made grid integration and operational issues focal points in industry discussions and research. Compliance with grid connection standards for wind power plants (WPP) is crucial to ensuring the safe and stable operation of the electric power grid. The standards for grid-connected WPPs in China and the United States are compared in this paper to facilitate further improvements to the standards and enhance the development of wind power equipment. Detailed analyses in power quality, low-voltage ride-through capability, active power control, reactive power control, voltage control, and wind power forecasting are provided to enhance themore » understanding of grid codes in the two largest markets of wind power.« less
Mashburn, Andrew J; Downer, Jason T; Rivers, Susan E; Brackett, Marc A; Martinez, Andres
2014-04-01
Social and emotional learning programs are designed to improve the quality of social interactions in schools and classrooms in order to positively affect students' social, emotional, and academic development. The statistical power of group randomized trials to detect effects of social and emotional learning programs and other preventive interventions on setting-level outcomes is influenced by the reliability of the outcome measure. In this paper, we apply generalizability theory to an observational measure of the quality of classroom interactions that is an outcome in a study of the efficacy of a social and emotional learning program called The Recognizing, Understanding, Labeling, Expressing, and Regulating emotions Approach. We estimate multiple sources of error variance in the setting-level outcome and identify observation procedures to use in the efficacy study that most efficiently reduce these sources of error. We then discuss the implications of using different observation procedures on both the statistical power and the monetary costs of conducting the efficacy study.
ERIC Educational Resources Information Center
Eastman, Clyde; And Others
Recently American attention has focused on the problems of pollution and environmental protection. Focusing on the Four Corners Interstate Air Quality Control Region, this study determined which socioeconomic characteristics were associated with concern for environmental quality as measured by willingness to pay for pollution abatement. Sample…
The application of nirvana to silvicultural studies
Chi-Leung So; Thomas Elder; Leslie Groom; John S. Kush; Jennifer Myszewski; Todd Shupe
2006-01-01
Previous results from this laboratory have shown that near infrared (NIR) spectroscopy, coupled with multivariate analysis, can be a powerful tool for the prediction of wood quality. While wood quality measurements are of utility, their determination can be both time and labor intensive, thus limiting their use where large sample sizes are concerned. This paper will...
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. Efforts solely focused on empowering women should also take the dyadic environment and men’s perspectives into account to ensure positive relationship outcomes. PMID:26859436
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 take the dyadic environment and men's perspectives into account to ensure positive relationship outcomes. Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.
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…
Federal Register 2010, 2011, 2012, 2013, 2014
2010-04-16
..., recreation, water quality, and water supply. Public scoping for the MRAPS will begin in late May 2010. Future..., irrigation, navigation, power, recreation, water quality, and water supply. Section 108 of the Energy and... and wildlife, irrigation, power, recreation, water supply, and water quality control; defining the...
Government, politics and health policy: A quantitative analysis of 30 European countries.
Mackenbach, Johan P; McKee, Martin
2015-10-01
Public health policies are often dependent on political decision-making, but little is known of the impact of different forms of government on countries' health policies. In this exploratory study we studied the association between a wide range of process and outcome indicators of health policy and four groups of political factors (levels of democracy, e.g. voice and accountability; political representation, e.g. voter turnout; distribution of power, e.g. constraints on the executive; and quality of government, e.g. absence of corruption) in contemporary Europe. Data on 15 aspects of government and 18 indicators of health policy as well as on potential confounders were extracted from harmonized international data sources, covering 30 European countries and the years 1990-2010. In a first step, multivariate regression analysis was used to relate cumulative measures of government to indicators of health policy, and in a second step panel regression with country fixed effects was used to relate changes in selected measures of government to changes in indicators of health policy. In multivariate regression analyses, measures of quality of democracy and quality of government had many positive associations with process and outcome indicators of health policy, while measures of distribution of power and political representation had few and inconsistent associations. Associations for quality of democracy were robust against more extensive control for confounding variables, including tests in panel regressions with country fixed effects, but associations for quality of government were not. In this period in Europe, the predominant political influence on health policy has been the rise of levels of democracy in countries in the Central & Eastern part of the region. In contrast to other areas of public policy, health policy does not appear to be strongly influenced by institutional features of democracy determining the distribution of power, nor by aspects of political representation. The effect of quality of government on health policy warrants more study. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.
Compressed Air Quality, A Case Study In Paiton Coal Fired Power Plant Unit 1 And 2
NASA Astrophysics Data System (ADS)
Indah, Nur; Kusuma, Yuriadi; Mardani
2018-03-01
The compressed air system becomes part of a very important utility system in a Plant, including the Steam Power Plant. In PLN’S coal fired power plant, Paiton units 1 and 2, there are four Centrifugal air compressor types, which produce compressed air as much as 5.652 cfm and with electric power capacity of 1200 kW. Electricity consumption to operate centrifugal compressor is 7.104.117 kWh per year. Compressed air generation is not only sufficient in quantity (flow rate) but also meets the required air quality standards. compressed air at Steam Power Plant is used for; service air, Instrument air, and for fly Ash. This study aims to measure some important parameters related to air quality, followed by potential disturbance analysis, equipment breakdown or reduction of energy consumption from existing compressed air conditions. These measurements include counting the number of dust particles, moisture content, relative humidity, and also compressed air pressure. From the measurements, the compressed air pressure generated by the compressor is about 8.4 barg and decreased to 7.7 barg at the furthest point, so the pressure drop is 0.63 barg, this number satisfies the needs in the end user. The measurement of the number of particles contained in compressed air, for particle of 0.3 micron reaches 170,752 particles, while for the particle size 0.5 micron reaches 45,245 particles. Measurements of particles conducted at several points of measurement. For some point measurements the number of dust particle exceeds the standard set by ISO 8573.1-2010 and also NACE Code, so it needs to be improved on the air treatment process. To see the amount of moisture content in compressed air, it is done by measuring pressure dew point temperature (PDP). Measurements were made at several points with results ranging from -28.4 to 30.9 °C. The recommendation of improving compressed air quality in steam power plant, Paiton unit 1 and 2 has the potential to extend the life of instrumentation equipment, improve the reliability of equipment, and reduce the amount of energy consumption up to 502,579 kWh per year.
(S)exclusion in the Sexuality Education Classroom: Young People on Gender and Power Relations
ERIC Educational Resources Information Center
Le Mat, Marielle L. J.
2017-01-01
Comprehensive sexuality education which includes discussion about gender and power is increasingly seen as an effective way of promoting sexual and reproductive health and rights. Yet all too often the potential of good quality sexuality education is not realised. This study engages with young peoples' evaluation of a sexuality education programme…
Piloted simulation study of two tilt-wing flap control concepts, phase 2
NASA Technical Reports Server (NTRS)
Birckelbaw, Lourdes G.; Corliss, Lloyd D.; Hindson, William S.; Churchill, Gary B.
1994-01-01
A two phase piloted simulation study has been conducted in the Ames Vertical Motion Simulator to investigate alternative wing and flap controls for tilt-wing aircraft. This report documents the flying qualities results and findings of the second phase of the piloted simulation study and describes the simulated tilt-wing aircraft, the flap control concepts, the experiment design and the evaluation tasks. The initial phase of the study compared the flying qualities of both a conventional programmed flap and an innovative geared flap. The second phase of the study introduced an alternate method of pilot control for the geared flap and further studied the flying qualities of the programmed flap and two geared flap configurations. In general, the pilot ratings showed little variation between the programmed flap and the geared flap control concepts. Some differences between the two control concepts were noticed and are discussed in this report. The geared flap configurations had very similar results. Although the geared flap concept has the potential to reduce or eliminate the pitch control power requirements from a tail rotor or a tail thruster at low speeds and in hover, the results did not show reduced tail thruster pitch control power usage with the geared flap configurations compared to the programmed flap configuration. The addition of pitch attitude stabilization in the second phase of simulation study greatly enhanced the aircraft flying qualities compared to the first phase.
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.
What Happened to Our Environment and Mental Health as a Result of Hurricane Sandy?
Lin, Shao; Lu, Yi; Justino, John; Dong, Guanghui; Lauper, Ursula
2016-06-01
This study describes findings of the impacts of Hurricane Sandy on environmental factors including power outages, air quality, water quality, and weather factors and how these affected mental health during the hurricane. An ecological study was conducted at the county level to describe changes in environmental factors-especially power outages-and their relationships to emergency department (ED) visits for mental health problems by use of a Poisson regression model. We found that many environmental hazards occurred as co-exposures during Hurricane Sandy in addition to flooding. Mental health ED visits corresponded with the peak of maximum daily power blackouts, with a 3-day lag, and were positively associated with power blackouts in Bronx (prevalence ratio [PR]: 8.82, 95% confidence interval [CI]: 1.27-61.42) and Queens (PR: 2.47, 95% CI: 1.05-5.82) counties. A possible dose-response relationship was found between the quantile of maximum blackout percentage and the risk of mental health in the Bronx. We found that multiple co-environmental hazards occurred during Hurricane Sandy, especially power blackouts that mediated this disaster's impacts. The effects of power outage on mental health had large geographic variations and were substantial, especially in communities with low sociodemographic status. These findings may provide new insights for future disaster response and preparedness efforts. (Disaster Med Public Health Preparedness. 2016;10:314-319).
The Impact of Transformer Winding Connections of A Grid-Connected PV on Voltage Quality Improvement
DOE Office of Scientific and Technical Information (OSTI.GOV)
Muljadi, Eduard; Tumbelaka, Hanny H.; Gao, Wenzhong
In this paper, the high-power PV plant is connected to the weak grid by means of a three-phase power transformer. The selection of transformer winding connection is critical especially when the PV inverter has a reactive power controller. In general, transformer winding connection can be arranged in star-star (with neutral earthed) or star-delta. The reactive power controller supports voltage regulation of the power system particularly under transient faults. Its control strategy is based on utilizing the grid currents to make a three-phase reactive unbalanced current with a small gain. The gain is determined by the system impedance. Simulation results exhibitmore » that the control strategy works very well particularly under disturbance conditions when the transformer winding connection is star-star with both neutrals grounded. The power quality in terms of the voltage quality is improved.« less
NASA Astrophysics Data System (ADS)
Chu, Qiuhui; Zhao, Pengfei; Li, Chengyu; Wang, Bopeng; Lin, Honghuan; Guo, Chao; Liu, Yu; Jing, Feng; Tang, Chuanxiang
2018-03-01
A high power 1030 nm ytterbium-doped polarization maintained fiber laser with optimized parameters is presented in this paper. The master oscillator power amplifier system with counter-pumped amplifier is established. The output power is 900 W, along with a light-to-light efficiency of 64.2%. The amplified spontaneous emission suppression ratio of spectrum reaches to 40 dB with 3 dB linewidth of 0.14 nm. The polarization extinction ratio is 12 dB, and the beam quality factor is M2x=1.07, M2y=1.12. To the best of our knowledge, this is the first demonstration of 1030 nm high power fiber laser with narrow linewidth, near linear polarization, and neardiffraction-limited beam quality
McMaster, Daniel Travis; Gill, Nicholas; Cronin, John; McGuigan, Michael
2013-05-01
Strength and power are crucial components to excelling in all contact sports; and understanding how a player's strength and power levels fluctuate in response to various resistance training loads is of great interest, as it will inevitably dictate the loading parameters throughout a competitive season. This is a systematic review of training, maintenance and detraining studies, focusing on the development, retention and decay rates of strength and power measures in elite rugby union, rugby league and American football players. A literature search using MEDLINE, EBSCO Host, Google Scholar, IngentaConnect, Ovid LWW, ProQuest Central, ScienceDirect Journals, SPORTDiscus and Wiley InterScience was conducted. References were also identified from other review articles and relevant textbooks. From 300 articles, 27 met the inclusion criteria and were retained for further analysis. STUDY QUALITY: Study quality was assessed via a modified 20-point scale created to evaluate research conducted in athletic-based training environments. The mean ± standard deviation (SD) quality rating of the included studies was 16.2 ± 1.9; the rating system revealed that the quality of future studies can be improved by randomly allocating subjects to training groups, providing greater description and detail of the interventions, and including control groups where possible. Percent change, effect size (ES = [Post-Xmean - Pre-Xmean)/Pre-SD) calculations and SDs were used to assess the magnitude and spread of strength and power changes in the included studies. The studies were grouped according to (1) mean intensity relative volume (IRV = sets × repetitions × intensity; (2) weekly training frequency per muscle group; and (3) detraining duration. IRV is the product of the number of sets, repetitions and intensity performed during a training set and session. The effects of weekly training frequencies were assessed by normalizing the percent change values to represent the weekly changes in strength and power. During the IRV analysis, the percent change values were normalized to represent the percent change per training session. The long-term periodized training effects (12, 24 and 48 months) on strength and power were also investigated. Across the 27 studies (n = 1,015), 234 percent change and 230 ES calculations were performed. IRVs of 11-30 (i.e., 3-6 sets of 4-10 repetitions at 74-88% one-repetition maximum [1RM]) elicited strength and power increases of 0.42% and 0.07% per training session, respectively. The following weekly strength changes were observed for two, three and four training sessions per muscle region/week: 0.9%, 1.8 % and 1.3 %, respectively. Similarly, the weekly power changes for two, three and four training sessions per muscle group/week were 0.1%, 0.3% and 0.7 %, respectively. Mean decreases of 14.5% (ES = -0.64) and 0.4 (ES = -0.10) were observed in strength and power across mean detraining periods of 7.2 ± 5.8 and 7.6 ± 5.1 weeks, respectively. The long-term training studies found strength increases of 7.1 ± 1.0% (ES = 0.55), 8.5 ± 3.3% (ES = 0.81) and 12.5 ± 6.8% (ES = 1.39) over 12, 24 and 48 months, respectively; they also found power increases of 14.6% (ES = 1.30) and 12.2% (ES = 1.06) at 24 and 48 months. Based on current findings, training frequencies of two to four resistance training sessions per muscle group/week can be prescribed to develop upper and lower body strength and power. IRVs ranging from 11 to 30 (i.e., 3-6 sets of 4-10 repetitions of 70-88% 1RM) can be prescribed in a periodized manner to retain power and develop strength in the upper and lower body. Strength levels can be maintained for up to 3 weeks of detraining, but decay rates will increase thereafter (i.e. 5-16 weeks). The effect of explosive-ballistic training and detraining on pure power development and decay in elite rugby and American football players remain inconclusive. The long-term effects of periodized resistance training programmes on strength and power seem to follow the law of diminishing returns, as training exposure increases beyond 12-24 months, adaptation rates are reduced.
Pacsi, Adam P; Kimura, Yosuke; McGaughey, Gary; McDonald-Buller, Elena C; Allen, David T
2015-03-17
The combined emissions and air quality impacts of electricity generation in the Texas grid and natural gas production in the Eagle Ford shale were estimated at various natural gas price points for the power sector. The increased use of natural gas in the power sector, in place of coal-fired power generation, drove reductions in average daily maximum 8 h ozone concentration of 0.6-1.3 ppb in northeastern Texas for a high ozone episode used in air quality planning. The associated increase in Eagle Ford upstream oil and gas production nitrogen oxide (NOx) emissions caused an estimated local increase, in south Texas, of 0.3-0.7 ppb in the same ozone metric. In addition, the potential ozone impacts of Eagle Ford emissions on nearby urban areas were estimated. On the basis of evidence from this work and a previous study on the Barnett shale, the combined ozone impact of increased natural gas development and use in the power sector is likely to vary regionally and must be analyzed on a case by case basis.
Power flow prediction in vibrating systems via model reduction
NASA Astrophysics Data System (ADS)
Li, Xianhui
This dissertation focuses on power flow prediction in vibrating systems. Reduced order models (ROMs) are built based on rational Krylov model reduction which preserve power flow information in the original systems over a specified frequency band. Stiffness and mass matrices of the ROMs are obtained by projecting the original system matrices onto the subspaces spanned by forced responses. A matrix-free algorithm is designed to construct ROMs directly from the power quantities at selected interpolation frequencies. Strategies for parallel implementation of the algorithm via message passing interface are proposed. The quality of ROMs is iteratively refined according to the error estimate based on residual norms. Band capacity is proposed to provide a priori estimate of the sizes of good quality ROMs. Frequency averaging is recast as ensemble averaging and Cauchy distribution is used to simplify the computation. Besides model reduction for deterministic systems, details of constructing ROMs for parametric and nonparametric random systems are also presented. Case studies have been conducted on testbeds from Harwell-Boeing collections. Input and coupling power flow are computed for the original systems and the ROMs. Good agreement is observed in all cases.
Huang, Hsuan-Ming; Hsiao, Ing-Tsung
2016-01-01
In recent years, there has been increased interest in low-dose X-ray cone beam computed tomography (CBCT) in many fields, including dentistry, guided radiotherapy and small animal imaging. Despite reducing the radiation dose, low-dose CBCT has not gained widespread acceptance in routine clinical practice. In addition to performing more evaluation studies, developing a fast and high-quality reconstruction algorithm is required. In this work, we propose an iterative reconstruction method that accelerates ordered-subsets (OS) reconstruction using a power factor. Furthermore, we combine it with the total-variation (TV) minimization method. Both simulation and phantom studies were conducted to evaluate the performance of the proposed method. Results show that the proposed method can accelerate conventional OS methods, greatly increase the convergence speed in early iterations. Moreover, applying the TV minimization to the power acceleration scheme can further improve the image quality while preserving the fast convergence rate.
Kulkarni, Vikrant A; Naidu, Velamala S; Jagtap, Tanaji G
2011-03-01
Estuaries and tidal creeks, harboring mangroves particularly, face tremendous anthropogenic pressures. Expansion of mega cities and the thermal power plants are generally proposed in the vicinity of estuaries and creek, due to the feasibility of intake and discharge of water for cooling. Discharges from such developments remain constant threat of increasing thermal pollution and affecting the quality of environment. The baseline information on prevailing quality of aquatic environment comes handy for understanding alterations due to such activities. Principle component analysis (PCA) revealed that temperature, pH, salinity, suspended solids, DO, BOD and phaeophytins are major parameters influencing the creek system. Heated effluents may have direct and adverse impacts on these parameters, altering biotic constituents. Hence, periodic and detailed observations are necessary to estimate exact response of biotic communities to changing environment. The present paper is based on case study, projecting a power plant in the vicinity of major mangrove habitats of Dharamtar creek.
Huang, Hsuan-Ming; Hsiao, Ing-Tsung
2016-01-01
In recent years, there has been increased interest in low-dose X-ray cone beam computed tomography (CBCT) in many fields, including dentistry, guided radiotherapy and small animal imaging. Despite reducing the radiation dose, low-dose CBCT has not gained widespread acceptance in routine clinical practice. In addition to performing more evaluation studies, developing a fast and high-quality reconstruction algorithm is required. In this work, we propose an iterative reconstruction method that accelerates ordered-subsets (OS) reconstruction using a power factor. Furthermore, we combine it with the total-variation (TV) minimization method. Both simulation and phantom studies were conducted to evaluate the performance of the proposed method. Results show that the proposed method can accelerate conventional OS methods, greatly increase the convergence speed in early iterations. Moreover, applying the TV minimization to the power acceleration scheme can further improve the image quality while preserving the fast convergence rate. PMID:27073853
The development of the Pictorial Thai Quality of Life.
Phattharayuttawat, Sucheera; Ngamthipwatthana, Thienchai; Pitiyawaranun, Buncha
2005-11-01
"Quality of life" has become a main focus of interest in medicine. The Pictorial Thai Quality of Life (PTQL) was developed in order to measure the Thai mental illness both in a clinical setting and community. The purpose of this study was to develop the Pictorial Thai Quality of Life (PTQL), having adequate and sufficient construct validity, discriminant power, concurrent validity, and reliability. To develop the Pictorial Thai Quality of Life Test, two samples groups were used in the present study: (1) pilot study samples: 30 samples and (2) survey samples were 672 samples consisting of normal, and psychiatric patients. The developing tests items were collected from a review of the literature in which all the items were based on the WHO definition of Quality of Life. Then, experts judgment by the Delphi technique was used in the first stage. After that a pilot study was used to evaluate the testing administration, and wording of the tests items. The final stage was collected data from the survey samples. The results of the present study showed that the final test was composed 25 items. The construct validity of this test consists of six domains: Physical, Cognitive, Affective, Social Function, Economic and Self-Esteem. All the PTQL items have sufficient discriminant power It was found to be statistically significant different at the. 001 level between those people with mental disorders and normal people. There was a high level of concurrent validity association with WHOQOL-BREF, Pearson correlation coefficient and Area under ROC curve were 0.92 and 0.97 respectively. The reliability coefficients for the Alpha coefficients of the PTQL total test was 0.88. The values of the six scales were from 0.81 to 0:91. The present study was directed at developing an effective psychometric properties pictorial quality of life questionnaire. The result will be a more direct and meaningful application of an instrument to detect the mental health illness poor quality of life in Thai communities.
The Impact of Involving Students in Managing the Quality of Higher Education Provision
ERIC Educational Resources Information Center
Garwe, Evelyn Chiyevo
2015-01-01
This study was aimed at exploring the power of student involvement in improving quality of higher educational provision in private higher education institutions in Zimbabwe. A longitudinal approach involving two separate surveys and covering a period of three years was used. A preliminary survey aimed at assessing the issues that impact negatively…
ERIC Educational Resources Information Center
Reid, John Y.
The reorganization of the College of Education and Allied Professions at the University of Toledo is discussed. The analysis is based on Baldridge's political model, Bacharach and Lawler's views of politics and power, Pirsig's concept of quality, and the Oxford English Dictionary definitions of "passion." To investigate the…
Who Wears the Pants: The Implications of Gender and Power for Youth Heterosexual Relationships.
Bay-Cheng, Laina Y; Maguin, Eugene; Bruns, Anne E
2018-01-01
Relationships in which power is equally distributed are consistently associated with greater quality (e.g., deeper intimacy, less turmoil, more pleasure), but it can be difficult to strike such a balance. Furthermore, dominant gender scripts and norms are complexly intertwined with power in heterosexual relationships. We studied the joint implications of power and gender for relationship quality using 114 U.S. emerging adults' quantitative and qualitative assessments of 395 heterosexual relationships. Linear mixed method analyses indicated that participants found relationships in which they shared power or were dominant to be more intimate and stable than those in which they felt subordinate, but we found no link between power and pleasure. Gender acted as a moderator such that women rated relationships in which they felt subordinate as less intimate and more tumultuous than those in which they felt dominant, whereas men's ratings did not vary by whether they felt subordinate or dominant. Qualitative data also showed power imbalances to be more problematic for women: Of the 17 relationships involving an abusive or controlling partner, 15 were reported by women. We conclude that while both young men and young women may feel subordinate in relationships, the consequences thereof are more detrimental for young women.
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 in optimal transmission decisions due to different locations of air pollution and water stress in China (severe in the east and north respectively). To achieve both co-benefits simultaneously, it is therefore critical to coordinate policies that reduce air pollution (pollution tax) and water use (water pricing) with power sector planning.
Reliability of infarct volumetry: Its relevance and the improvement by a software-assisted approach.
Friedländer, Felix; Bohmann, Ferdinand; Brunkhorst, Max; Chae, Ju-Hee; Devraj, Kavi; Köhler, Yvette; Kraft, Peter; Kuhn, Hannah; Lucaciu, Alexandra; Luger, Sebastian; Pfeilschifter, Waltraud; Sadler, Rebecca; Liesz, Arthur; Scholtyschik, Karolina; Stolz, Leonie; Vutukuri, Rajkumar; Brunkhorst, Robert
2017-08-01
Despite the efficacy of neuroprotective approaches in animal models of stroke, their translation has so far failed from bench to bedside. One reason is presumed to be a low quality of preclinical study design, leading to bias and a low a priori power. In this study, we propose that the key read-out of experimental stroke studies, the volume of the ischemic damage as commonly measured by free-handed planimetry of TTC-stained brain sections, is subject to an unrecognized low inter-rater and test-retest reliability with strong implications for statistical power and bias. As an alternative approach, we suggest a simple, open-source, software-assisted method, taking advantage of automatic-thresholding techniques. The validity and the improvement of reliability by an automated method to tMCAO infarct volumetry are demonstrated. In addition, we show the probable consequences of increased reliability for precision, p-values, effect inflation, and power calculation, exemplified by a systematic analysis of experimental stroke studies published in the year 2015. Our study reveals an underappreciated quality problem in translational stroke research and suggests that software-assisted infarct volumetry might help to improve reproducibility and therefore the robustness of bench to bedside translation.
Occupational Electromagnetic Field Exposures Associated with Sleep Quality: A Cross-Sectional Study
Liu, Hui; Chen, Guangdi; Pan, Yifeng; Chen, Zexin; Jin, Wen; Sun, Chuan; Chen, Chunjing; Dong, Xuanjun; Chen, Kun; Xu, Zhengping; Zhang, Shanchun; Yu, Yunxian
2014-01-01
Background Exposure to electromagnetic field (EMF) emitted by mobile phone and other machineries concerns half the world’s population and raises the problem of their impact on human health. The present study aims to explore the effects of electromagnetic field exposures on sleep quality and sleep duration among workers from electric power plant. Methods A cross-sectional study was conducted in an electric power plant of Zhejiang Province, China. A total of 854 participants were included in the final analysis. The detailed information of participants was obtained by trained investigators using a structured questionnaire, which including socio-demographic characteristics, lifestyle variables, sleep variables and electromagnetic exposures. Physical examination and venous blood collection were also carried out for every study subject. Results After grouping daily occupational electromagnetic exposure into three categories, subjects with long daily exposure time had a significantly higher risk of poor sleep quality in comparison to those with short daily exposure time. The adjusted odds ratios were 1.68 (95%CI: 1.18, 2.39) and 1.57 (95%CI: 1.10, 2.24) across tertiles. Additionally, among the subjects with long-term occupational exposure, the longer daily occupational exposure time apparently increased the risk of poor sleep quality (OR (95%CI): 2.12 (1.23∼3.66) in the second tertile; 1.83 (1.07∼3.15) in the third tertile). There was no significant association of long-term occupational exposure duration, monthly electric fee or years of mobile-phone use with sleep quality or sleep duration. Conclusions The findings showed that daily occupational EMF exposure was positively associated with poor sleep quality. It implies EMF exposure may damage human sleep quality rather than sleep duration. PMID:25340654
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 alarm is instigated predicting the advent of system abnormal operation. The incoming data could be compared to previous trends as well as matched to trends developed through computer simulations and stored using fuzzy learning.
NASA Astrophysics Data System (ADS)
Rizy, D. T.; Jewell, W. T.
1984-10-01
There are several operational problems associated with the connection of small power sources, such as wind turbines and photovoltaic (PV) arrays, to an electric distribution system. In one study the harmonic distortion produced by a subdivision of PV arrays connected through line-commutated inverters was simulated. A second simulation study evaluated protection problems associated with the operation of dispersed ac generators. The purpose of these studies was to examine the adequacy of the electric utility industry's traditional practices and hardware for the operation of dispersed power sources. The results of these simulation studies are discussed and recommendations are given for hardware and system operation needed for accommodating this new technology.
Low-Voltage Organic Single-Crystal Field-Effect Transistor with Steep Subthreshold Slope.
Yang, Fangxu; Sun, Lingjie; Han, Jiangli; Li, Baili; Yu, Xi; Zhang, Xiaotao; Ren, Xiaochen; Hu, Wenping
2018-03-06
Anodization is a promising technique to form high- k dielectrics for low-power organic field-effect transistor (OFET) applications. However, the surface quality of the dielectric, which is mainly inherited from the metal electrode, can be improved further than other fabrication techniques, such as sol-gel. In this study, we applied the template stripping method to fabricate a low-power single-crystalline OFET based on the anodized AlO x dielectric. We found that the template stripping method largely improves the surface roughness of the deposited Al and allows for the formation of a high-quality AlO x high- k dielectric by anodization. The ultraflat AlO x /SAM dielectric combined with a single-crystal 2,6-diphenylanthracene (DPA) semiconductor produced a nearly defect-free interface with a steep subthreshold swing (SS) of 66 mV/decade. The current device is a promising candidate for future ultralow-power applications. Other than metal deposition, template stripping could provide a general approach to improve thin-film quality for many other types of materials and processes.
NASA Astrophysics Data System (ADS)
Asal, F. F.
2012-07-01
Digital elevation data obtained from different Engineering Surveying techniques is utilized in generating Digital Elevation Model (DEM), which is employed in many Engineering and Environmental applications. This data is usually in discrete point format making it necessary to utilize an interpolation approach for the creation of DEM. Quality assessment of the DEM is a vital issue controlling its use in different applications; however this assessment relies heavily on statistical methods with neglecting the visual methods. The research applies visual analysis investigation on DEMs generated using IDW interpolator of varying powers in order to examine their potential in the assessment of the effects of the variation of the IDW power on the quality of the DEMs. Real elevation data has been collected from field using total station instrument in a corrugated terrain. DEMs have been generated from the data at a unified cell size using IDW interpolator with power values ranging from one to ten. Visual analysis has been undertaken using 2D and 3D views of the DEM; in addition, statistical analysis has been performed for assessment of the validity of the visual techniques in doing such analysis. Visual analysis has shown that smoothing of the DEM decreases with the increase in the power value till the power of four; however, increasing the power more than four does not leave noticeable changes on 2D and 3D views of the DEM. The statistical analysis has supported these results where the value of the Standard Deviation (SD) of the DEM has increased with increasing the power. More specifically, changing the power from one to two has produced 36% of the total increase (the increase in SD due to changing the power from one to ten) in SD and changing to the powers of three and four has given 60% and 75% respectively. This refers to decrease in DEM smoothing with the increase in the power of the IDW. The study also has shown that applying visual methods supported by statistical analysis has proven good potential in the DEM quality assessment.
Establishing a Cloud Computing Success Model for Hospitals in Taiwan.
Lian, Jiunn-Woei
2017-01-01
The purpose of this study is to understand the critical quality-related factors that affect cloud computing success of hospitals in Taiwan. In this study, private cloud computing is the major research target. The chief information officers participated in a questionnaire survey. The results indicate that the integration of trust into the information systems success model will have acceptable explanatory power to understand cloud computing success in the hospital. Moreover, information quality and system quality directly affect cloud computing satisfaction, whereas service quality indirectly affects the satisfaction through trust. In other words, trust serves as the mediator between service quality and satisfaction. This cloud computing success model will help hospitals evaluate or achieve success after adopting private cloud computing health care services.
Establishing a Cloud Computing Success Model for Hospitals in Taiwan
Lian, Jiunn-Woei
2017-01-01
The purpose of this study is to understand the critical quality-related factors that affect cloud computing success of hospitals in Taiwan. In this study, private cloud computing is the major research target. The chief information officers participated in a questionnaire survey. The results indicate that the integration of trust into the information systems success model will have acceptable explanatory power to understand cloud computing success in the hospital. Moreover, information quality and system quality directly affect cloud computing satisfaction, whereas service quality indirectly affects the satisfaction through trust. In other words, trust serves as the mediator between service quality and satisfaction. This cloud computing success model will help hospitals evaluate or achieve success after adopting private cloud computing health care services. PMID:28112020
TCSC based filtering and improvement of power quality
NASA Astrophysics Data System (ADS)
Arulvendhan, K.; Dilli srinivasan, J.; Vinil, M.
2018-04-01
Thyristor Controlled Series Capacitor (TCSC) as a dynamic system, also its competence in growing power allocation in transmission lines, can be used to improve different power system problems. TCSC’s dissimilar advantages can be categorised as steady-state and transient ones. During a fault, TCSC can increase power quality by reducing the current and benefit to keep the voltage as high as conceivable. In this paper, the application of TCSC to enrich one of the vital power quality issues, i.e., voltage sag is investigated. Different operating modes of TCSC have dissimilar influences on the voltage of the bus that the line armed with TCSC is connected to. Relocating to bypass mode upon manifestation of a fault is a significant feature of TCSC to advance voltage sag. The simulations on a trial network disclose these facts.
Propagation of rotational Risley-prism-array-based Gaussian beams in turbulent atmosphere
NASA Astrophysics Data System (ADS)
Chen, Feng; Ma, Haotong; Dong, Li; Ren, Ge; Qi, Bo; Tan, Yufeng
2018-03-01
Limited by the size and weight of prism and optical assembling, Rotational Risley-prism-array system is a simple but effective way to realize high power and superior beam quality of deflecting laser output. In this paper, the propagation of the rotational Risley-prism-array-based Gaussian beam array in atmospheric turbulence is studied in detail. An analytical expression for the average intensity distribution at the receiving plane is derived based on nonparaxial ray tracing method and extended Huygens-Fresnel principle. Power in the diffraction-limited bucket is chosen to evaluate beam quality. The effect of deviation angle, propagation distance and intensity of turbulence on beam quality is studied in detail by quantitative simulation. It reveals that with the propagation distance increasing, the intensity distribution gradually evolves from multiple-petal-like shape into the pattern that contains one main-lobe in the center with multiple side-lobes in weak turbulence. The beam quality of rotational Risley-prism-array-based Gaussian beam array with lower deviation angle is better than its counterpart with higher deviation angle when propagating in weak and medium turbulent (i.e. Cn2 < 10-13m-2/3), the beam quality of higher deviation angle arrays degrades faster as the intensity of turbulence gets stronger. In the case of propagating in strong turbulence, the long propagation distance (i.e. z > 10km ) and deviation angle have no influence on beam quality.
High Quality Data for Grid Integration Studies
DOE Office of Scientific and Technical Information (OSTI.GOV)
Clifton, Andrew; Draxl, Caroline; Sengupta, Manajit
As variable renewable power penetration levels increase in power systems worldwide, renewable integration studies are crucial to ensure continued economic and reliable operation of the power grid. The existing electric grid infrastructure in the US in particular poses significant limitations on wind power expansion. In this presentation we will shed light on requirements for grid integration studies as far as wind and solar energy are concerned. Because wind and solar plants are strongly impacted by weather, high-resolution and high-quality weather data are required to drive power system simulations. Future data sets will have to push limits of numerical weather predictionmore » to yield these high-resolution data sets, and wind data will have to be time-synchronized with solar data. Current wind and solar integration data sets are presented. The Wind Integration National Dataset (WIND) Toolkit is the largest and most complete grid integration data set publicly available to date. A meteorological data set, wind power production time series, and simulated forecasts created using the Weather Research and Forecasting Model run on a 2-km grid over the continental United States at a 5-min resolution is now publicly available for more than 126,000 land-based and offshore wind power production sites. The National Solar Radiation Database (NSRDB) is a similar high temporal- and spatial resolution database of 18 years of solar resource data for North America and India. The need for high-resolution weather data pushes modeling towards finer scales and closer synchronization. We also present how we anticipate such datasets developing in the future, their benefits, and the challenges with using and disseminating such large amounts of data.« less
Analyzing Small Signal Stability of Power System based on Online Data by Use of SMES
NASA Astrophysics Data System (ADS)
Ishikawa, Hiroyuki; Shirai, Yasuyuki; Nitta, Tanzo; Shibata, Katsuhiko
The purpose of this study is to estimate eigen-values and eigen-vectors of a power system from on-line data to evaluate the power system stability. Power system responses due to the small power modulation of known pattern from SMES (Superconducting Magnetic Energy Storage) were analyzed, and the transfer functions between the power modulation and power oscillations of generators were obtained. Eigen-values and eigen-vectors were estimated from the transfer functions. Experiments were carried out by use of a model SMES and Advanced Power System Analyzer (APSA), which is an analogue type power system simulator of Kansai Electric Power Company Inc., Japan. Changes in system condition were observed by the estimated eigen-values and eigen-vectors. Result agreed well with the resent report and digital simulation. This method gives a new application for SMES, which will be installed for improving electric power quality.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Gao, David Wenzhong; Muljadi, Eduard; Tian, Tian
The rapid deployment of wind power has made grid integration and operational issues focal points in industry discussions and research. Compliance with grid connection standards for wind power plants (WPPs) is crucial to ensuring the reliable and stable operation of the electric power grid. This report compares the standards for grid-connected WPPs in China to those in the United States to facilitate further improvements in wind power standards and enhance the development of wind power equipment. Detailed analyses of power quality, low-voltage ride-through capability, active power control, reactive power control, voltage control, and wind power forecasting are provided to enhancemore » the understanding of grid codes in the two largest markets of wind power. This study compares WPP interconnection standards and technical requirements in China to those in the United States.« less
Arjmandi, Mitra; Otón, Mariano; Artés, Francisco; Artés-Hernández, Francisco; Gómez, Perla A; Aguayo, Encarna
2017-02-01
Thermal processing causes a number of undesirable changes in physicochemical and bioactive properties of tomato products. Microwave (MW) technology is an emergent thermal industrial process that offers a rapid and uniform heating, high energy efficiency and high overall quality of the final product. The main quality changes of tomato puree after pasteurization at 96 ± 2 °C for 35 s, provided by a semi-industrial continuous microwave oven (MWP) under different doses (low power/long time to high power/short time) or by conventional method (CP) were studied. All heat treatments reduced colour quality, total antioxidant capacity and vitamin C, with a greater reduction in CP than in MWP. On the other hand, use of an MWP, in particular high power/short time (1900 W/180 s, 2700 W/160 s and 3150 W/150 s) enhanced the viscosity and lycopene extraction and decreased the enzyme residual activity better than with CP samples. For tomato puree, polygalacturonase was the more thermo-resistant enzyme, and could be used as an indicator of pasteurization efficiency. MWP was an excellent pasteurization technique that provided tomato puree with improved nutritional quality, reducing process times compared to the standard pasteurization process. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.
Wedge cutting of mild steel by CO 2 laser and cut-quality assessment in relation to normal cutting
NASA Astrophysics Data System (ADS)
Yilbas, B. S.; Karatas, C.; Uslan, I.; Keles, O.; Usta, Y.; Yilbas, Z.; Ahsan, M.
2008-10-01
In some applications, laser cutting of wedge surfaces cannot be avoided in sheet metal processing and the quality of the end product defines the applicability of the laser-cutting process in such situations. In the present study, CO 2 laser cutting of the wedge surfaces as well as normal surfaces (normal to laser beam axis) is considered and the end product quality is assessed using the international standards for thermal cutting. The cut surfaces are examined by the optical microscopy and geometric features of the cut edges such as out of flatness and dross height are measured from the micrographs. A neural network is introduced to classify the striation patterns of the cut surfaces. It is found that the dross height and out of flatness are influenced significantly by the laser output power, particularly for wedge-cutting situation. Moreover, the cut quality improves at certain value of the laser power intensity.
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.
A Comparative Study of Power Supply Architectures In Wireless Electric Vehicle Charging Systems
NASA Astrophysics Data System (ADS)
Esteban, Bryan
Wireless inductive power transfer is a transformational and disruptive technology that enables the reliable and efficient transfer of electrical power over large air gaps for a host of unique applications. One such application that is now gaining much momentum worldwide is the wireless charging of electric vehicles (EVs). This thesis examines two of the primary power supply topologies being predominantly used for EV charging, namely the SLC and the LCL resonant full bridge inverter topologies. The study of both of these topologies is presented in the context of designing a 3 kW, primary side controlled, wireless EV charger with nominal operating parameters of 30 kHz centre frequency and range of coupling in the neighborhood of .18-.26. A comparison of both topologies is made in terms of their complexity, cost, efficiency, and power quality. The aim of the study is to determine which topology is better for wireless EV charging.
The power of power wheelchairs: Mobility choices of community-dwelling, older adults
Mortenson, WB; Hammell, KW; Luts, A; Soles, C; Miller, WC
2015-01-01
Background Power wheelchairs are purported to have a positive effect on health, occupation, and quality of life. However, there is limited knowledge about what factors shape power wheelchair use decisions. Aims/Objectives A study was undertaken to understand the mobility choices of community-dwelling, power wheelchair users. Methods A series of semi-structured qualitative interviews was conducted with 13 older adult power wheelchair users. Participants were interviewed at enrollment and four months later. Data analysis was informed by Bourdieu’s theoretical constructs of habitus, capital, and field. Results Three main styles of power wheelchair use were identified: reluctant use, strategic use and essential use, and each type is illustrated using an aggregate case study. Conclusion/Significance These findings highlight the need to alter the power relationship that exists between prescribers and device users and to effect policy changes that enable people with physical impairments to make as wide a range of mobility choices as possible. PMID:26027749
NASA Astrophysics Data System (ADS)
Wilcox, Steve; Myers, Daryl
2009-08-01
The U.S. Department of Energy's National Renewable Energy Laboratory has embarked on a collaborative effort with the solar industry to establish high quality solar and meteorological measurements. This Solar Resource and Meteorological Assessment Project (SOLRMAP) provides high quality measurements to support deployment of concentrating solar thermal power projects in the United States. The no-funds-exchanged collaboration brings NREL solar resource assessment expertise together with industry needs for measurements. The end result will be high quality data sets to support the financing, design, and monitoring of large scale solar power projects for industry in addition to research-quality data for NREL model development. NREL provides consultation for instrumentation and station deployment, along with instrument calibrations, data acquisition, quality assessment, data distribution, and summary reports. Industry participants provide equipment, infrastructure, and station maintenance.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Not Available
1980-06-01
Beginning in February, 1970, the Nuclear Materials and Equipment Corporation (NUMEC) undertook a program to design, develop and manufacture a radioisotope powered cardiac pacemaker system. The scope of technical work was specified to be: establish system, component, and process cost reduction goals using the prototype Radioisotope Powered Cardiac Pacemaker (RCP) design and develop production techniques to achieve these cost reduction objectives; fabricate radioisotope powered fueled prototype cardiac pacemakers (RCP's) on a pilot production basis; conduct liaison with a Government-designated fueling facility for purposes of defining fueling requirements, fabrication and encapsulation procedures, safety design criteria and quality control and inspection requirements;more » develop and implement Quality Assurance and Reliability Programs; conduct performance, acceptance, lifetime and reliability tests of fueled RCP's in the laboratory; conduct liaison with the National Institutes of Health and with Government specified medical research institutions selected for the purpose of undertaking clinical evaluation of the RCP in humans; monitor and evaluate, on a continuing basis, all test data; and perform necessary safety analyses and tests. Pacemaker designs were developed and quality assurance and manufacturing procedures established. Prototype pacemakers were fabricated. A total of 126 radioisotope powered units were implanted and have been followed clinically for approximately seven years. Four (4) of these units have failed. Eighty-three (83) units remain implanted and satisfactorily operational. An overall failure rate of less than the target 0.15% per month has been achieved.« less
NASA Astrophysics Data System (ADS)
Shaw, Amelia R.; Smith Sawyer, Heather; LeBoeuf, Eugene J.; McDonald, Mark P.; Hadjerioua, Boualem
2017-11-01
Hydropower operations optimization subject to environmental constraints is limited by challenges associated with dimensionality and spatial and temporal resolution. The need for high-fidelity hydrodynamic and water quality models within optimization schemes is driven by improved computational capabilities, increased requirements to meet specific points of compliance with greater resolution, and the need to optimize operations of not just single reservoirs but systems of reservoirs. This study describes an important advancement for computing hourly power generation schemes for a hydropower reservoir using high-fidelity models, surrogate modeling techniques, and optimization methods. The predictive power of the high-fidelity hydrodynamic and water quality model CE-QUAL-W2 is successfully emulated by an artificial neural network, then integrated into a genetic algorithm optimization approach to maximize hydropower generation subject to constraints on dam operations and water quality. This methodology is applied to a multipurpose reservoir near Nashville, Tennessee, USA. The model successfully reproduced high-fidelity reservoir information while enabling 6.8% and 6.6% increases in hydropower production value relative to actual operations for dissolved oxygen (DO) limits of 5 and 6 mg/L, respectively, while witnessing an expected decrease in power generation at more restrictive DO constraints. Exploration of simultaneous temperature and DO constraints revealed capability to address multiple water quality constraints at specified locations. The reduced computational requirements of the new modeling approach demonstrated an ability to provide decision support for reservoir operations scheduling while maintaining high-fidelity hydrodynamic and water quality information as part of the optimization decision support routines.
Shaw, Amelia R.; Sawyer, Heather Smith; LeBoeuf, Eugene J.; ...
2017-10-24
Hydropower operations optimization subject to environmental constraints is limited by challenges associated with dimensionality and spatial and temporal resolution. The need for high-fidelity hydrodynamic and water quality models within optimization schemes is driven by improved computational capabilities, increased requirements to meet specific points of compliance with greater resolution, and the need to optimize operations of not just single reservoirs but systems of reservoirs. This study describes an important advancement for computing hourly power generation schemes for a hydropower reservoir using high-fidelity models, surrogate modeling techniques, and optimization methods. The predictive power of the high-fidelity hydrodynamic and water quality model CE-QUAL-W2more » is successfully emulated by an artificial neural network, then integrated into a genetic algorithm optimization approach to maximize hydropower generation subject to constraints on dam operations and water quality. This methodology is applied to a multipurpose reservoir near Nashville, Tennessee, USA. The model successfully reproduced high-fidelity reservoir information while enabling 6.8% and 6.6% increases in hydropower production value relative to actual operations for dissolved oxygen (DO) limits of 5 and 6 mg/L, respectively, while witnessing an expected decrease in power generation at more restrictive DO constraints. Exploration of simultaneous temperature and DO constraints revealed capability to address multiple water quality constraints at specified locations. Here, the reduced computational requirements of the new modeling approach demonstrated an ability to provide decision support for reservoir operations scheduling while maintaining high-fidelity hydrodynamic and water quality information as part of the optimization decision support routines.« less
DOE Office of Scientific and Technical Information (OSTI.GOV)
Shaw, Amelia R.; Sawyer, Heather Smith; LeBoeuf, Eugene J.
Hydropower operations optimization subject to environmental constraints is limited by challenges associated with dimensionality and spatial and temporal resolution. The need for high-fidelity hydrodynamic and water quality models within optimization schemes is driven by improved computational capabilities, increased requirements to meet specific points of compliance with greater resolution, and the need to optimize operations of not just single reservoirs but systems of reservoirs. This study describes an important advancement for computing hourly power generation schemes for a hydropower reservoir using high-fidelity models, surrogate modeling techniques, and optimization methods. The predictive power of the high-fidelity hydrodynamic and water quality model CE-QUAL-W2more » is successfully emulated by an artificial neural network, then integrated into a genetic algorithm optimization approach to maximize hydropower generation subject to constraints on dam operations and water quality. This methodology is applied to a multipurpose reservoir near Nashville, Tennessee, USA. The model successfully reproduced high-fidelity reservoir information while enabling 6.8% and 6.6% increases in hydropower production value relative to actual operations for dissolved oxygen (DO) limits of 5 and 6 mg/L, respectively, while witnessing an expected decrease in power generation at more restrictive DO constraints. Exploration of simultaneous temperature and DO constraints revealed capability to address multiple water quality constraints at specified locations. Here, the reduced computational requirements of the new modeling approach demonstrated an ability to provide decision support for reservoir operations scheduling while maintaining high-fidelity hydrodynamic and water quality information as part of the optimization decision support routines.« less
The project MOHAVE tracer study: study design, data quality, and overview of results
NASA Astrophysics Data System (ADS)
Green, Mark C.
In the winter and summer of 1992, atmospheric tracer studies were conducted in support of project MOHAVE, a visibility study in the southwestern United States. The primary goal of project MOHAVE is to determine the effects of the Mohave power plant and other sources upon visibility at Grand Canyon National Park. Perfluorocarbon tracers (PFTs) were released from the Mohave power plant and other locations and monitored at about 30 sites. The tracer data are being used for source attribution analysis and for evaluation of transport and dispersion models and receptor models. Collocated measurements showed the tracer data to be of high quality and suitable for source attribution analysis and model evaluation. The results showed strong influences of channeling by the Colorado River canyon during both winter and summer. Flow from the Mohave power plant was usually to the south, away from the Grand Canyon in winter and to the northeast, toward the Grand Canyon in summer. Tracer released at Lake Powell in winter was found to often travel downstream through the entire length of the Grand Canyon. Data from summer tracer releases in southern California demonstrated the existence of a convergence zone in the western Mohave Desert.
ERIC Educational Resources Information Center
Butcher, Phillipa R.; van Braeckel, Koen; Bouma, Anke; Einspieler, Christa; Stremmelaar, Elisabeth F.; Bos, Arend F.
2009-01-01
Background: The quality of very preterm infants' spontaneous movements at 11 to 16 weeks post-term age is a powerful predictor of their later neurological status. This study investigated whether early spontaneous movements also have predictive value for the intellectual and behavioural problems that children born very preterm often experience.…
ERIC Educational Resources Information Center
Huang, Keng-Yen; Caughy, Margaret O'Brien; Lee, Li-Ching; Miller, Therese; Genevro, Janice
2008-01-01
This study examined the stability of maternal punitive/high-power discipline (PD) and inductive/authoritative discipline (ID) over the second and third years of life and the effect of maternal discipline on quality of mother-child interactions. Data from a longitudinal sample with 179 mother-toddler dyads were analyzed, and selected factors (i.e.,…
NASA Astrophysics Data System (ADS)
Rimov, A. A.; Chukanova, T. I.; Trofimov, Yu. V.
2016-12-01
Data on the comparative analysis variants of the quality of power installations (benchmarking) applied in the power industry is systematized. It is shown that the most efficient variant of implementation of the benchmarking technique is the analysis of statistical distributions of the indicators in the composed homogenous group of the uniform power installations. The benchmarking technique aimed at revealing the available reserves on improvement of the reliability and heat efficiency indicators of the power installations of the thermal power plants is developed in the furtherance of this approach. The technique provides a possibility of reliable comparison of the quality of the power installations in their homogenous group limited by the number and adoption of the adequate decision on improving some or other technical characteristics of this power installation. The technique provides structuring of the list of the comparison indicators and internal factors affecting them represented according to the requirements of the sectoral standards and taking into account the price formation characteristics in the Russian power industry. The mentioned structuring ensures traceability of the reasons of deviation of the internal influencing factors from the specified values. The starting point for further detail analysis of the delay of the certain power installation indicators from the best practice expressed in the specific money equivalent is positioning of this power installation on distribution of the key indicator being a convolution of the comparison indicators. The distribution of the key indicator is simulated by the Monte-Carlo method after receiving the actual distributions of the comparison indicators: specific lost profit due to the short supply of electric energy and short delivery of power, specific cost of losses due to the nonoptimal expenditures for repairs, and specific cost of excess fuel equivalent consumption. The quality loss indicators are developed facilitating the analysis of the benchmarking results permitting to represent the quality loss of this power installation in the form of the difference between the actual value of the key indicator or comparison indicator and the best quartile of the existing distribution. The uncertainty of the obtained values of the quality loss indicators was evaluated by transforming the standard uncertainties of the input values into the expanded uncertainties of the output values with the confidence level of 95%. The efficiency of the technique is demonstrated in terms of benchmarking of the main thermal and mechanical equipment of the extraction power-generating units T-250 and power installations of the thermal power plants with the main steam pressure 130 atm.
Dehesh, Tania; Zare, Najaf; Jafari, Peyman; Sagheb, Mohammad Mehdi
2014-06-01
This study aimed to assess the psychometric properties of the Persian version of the Ferrans and Powers 3.0 quality of life index (dialysis type) in patients receiving hemodialysis (HD) in order to describe their health-related quality of life (HRQOL). The sample (n = 150) consisted of adult HD patients receiving HD for at least 6 months from the establishment of the study. A total of 88 men and 62 women, with an average age of 50.47, from Shiraz, southern Iran, were enrolled in this study. The questionnaire was translated into Persian language using back translation and bilingual techniques. Convergent, discriminant, and construct validity of the Ferrans and Powers 3.0 dialysis version was evaluated. To check the internal consistency of the data, Cronbach's alpha, which indicates the reliability of the data, was used for the entire questionnaire and for the subscales. The convergent and discriminant validity and success scaling rate for both sexes were 100 %. Cronbach's alpha was 0.95 overall, which was greater than 0.7 for all the subscales except for the family subscale. Our results suggest that HD patients in southern Iran have higher HRQOL scores when compared with those in other countries. Despite the higher mean HRQOL score for men compared with women, men had significantly higher HRQOL scores only in the health and functioning subscale. There was no significant correlation between HD patients' HRQOL and educational level. The Persian version of Ferrans and Powers 3.0 has sufficient reliability and validity for measuring the quality of life of Persian-speaking HD patients. Female HD patients need more support and attention from family and society.
Hossain, Md Nazir; Paul, Shitangsu Kumar; Hasan, Md Muyeed
2015-04-01
The study was carried out to analyse the environmental impacts of coal mine and coal-based thermal power plant to the surrounding environment of Barapukuria, Dinajpur. The analyses of coal, water, soil and fly ash were carried out using standard sample testing methods. This study found that coal mining industry and coal-based thermal power plant have brought some environmental and socio-economic challenges to the adjacent areas such as soil, water and air pollution, subsidence of agricultural land and livelihood insecurity of inhabitants. The pH values, heavy metal, organic carbon and exchangeable cations of coal water treated in the farmland soil suggest that coal mining deteriorated the surrounding water and soil quality. The SO4(2-) concentration in water samples was beyond the range of World Health Organisation standard. Some physico-chemical properties such as pH, conductivity, moisture content, bulk density, unburned carbon content, specific gravity, water holding capacity, liquid and plastic limit were investigated on coal fly ash of Barapukuria thermal power plant. Air quality data provided by the Barapukuria Coal Mining Company Limited were contradictory with the result of interview with the miners and local inhabitants. However, coal potentially contributes to the development of economy of Bangladesh but coal mining deteriorates the environment by polluting air, water and soil. In general, this study includes comprehensive baseline data for decision makers to evaluate the feasibility of coal power industry at Barapukuria and the coalmine itself.
High-quality weather data for grid integration studies
NASA Astrophysics Data System (ADS)
Draxl, C.
2016-12-01
As variable renewable power penetration levels increase in power systems worldwide, renewable integration studies are crucial to ensure continued economic and reliable operation of the power grid. In this talk we will shed light on requirements for grid integration studies as far as wind and solar energy are concerned. Because wind and solar plants are strongly impacted by weather, high-resolution and high-quality weather data are required to drive power system simulations. Future data sets will have to push limits of numerical weather prediction to yield these high-resolution data sets, and wind data will have to be time-synchronized with solar data. Current wind and solar integration data sets will be presented. The Wind Integration National Dataset (WIND) Toolkit is the largest and most complete grid integration data set publicly available to date. A meteorological data set, wind power production time series, and simulated forecasts created using the Weather Research and Forecasting Model run on a 2-km grid over the continental United States at a 5-min resolution is now publicly available for more than 126,000 land-based and offshore wind power production sites. The Solar Integration National Dataset (SIND) is available as time synchronized with the WIND Toolkit, and will allow for combined wind-solar grid integration studies. The National Solar Radiation Database (NSRDB) is a similar high temporal- and spatial resolution database of 18 years of solar resource data for North America and India. Grid integration studies are also carried out in various countries, which aim at increasing their wind and solar penetration through combined wind and solar integration data sets. We will present a multi-year effort to directly support India's 24x7 energy access goal through a suite of activities aimed at enabling large-scale deployment of clean energy and energy efficiency. Another current effort is the North-American-Renewable-Integration-Study, with the aim of providing a seamless data set across borders for a whole continent, to simulate and analyze the impacts of potential future large wind and solar power penetrations on bulk power system operations.
Zhu, Yun; Lao, Yanwen; Jang, Carey; Lin, Chen-Jen; Xing, Jia; Wang, Shuxiao; Fu, Joshua S; Deng, Shuang; Xie, Junping; Long, Shicheng
2015-01-01
This article describes the development and implementations of a novel software platform that supports real-time, science-based policy making on air quality through a user-friendly interface. The software, RSM-VAT, uses a response surface modeling (RSM) methodology and serves as a visualization and analysis tool (VAT) for three-dimensional air quality data obtained by atmospheric models. The software features a number of powerful and intuitive data visualization functions for illustrating the complex nonlinear relationship between emission reductions and air quality benefits. The case study of contiguous U.S. demonstrates that the enhanced RSM-VAT is capable of reproducing the air quality model results with Normalized Mean Bias <2% and assisting in air quality policy making in near real time. Copyright © 2014. Published by Elsevier B.V.
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 utilised and their effectiveness evaluated. © 2016 Nordic College of Caring Science.
Singh, Kh. Manglem; Khelchandra, Thongam; Mehta, R. K.
2017-01-01
Every energy system which we consider is an entity by itself, defined by parameters which are interrelated according to some physical laws. In recent year tremendous importance is given in research on site selection in an imprecise environment. In this context, decision making for the suitable location of power plant installation site is an issue of relevance. Environmental impact assessment is often used as a legislative requirement in site selection for decades. The purpose of this current work is to develop a model for decision makers to rank or classify various power plant projects according to multiple criteria attributes such as air quality, water quality, cost of energy delivery, ecological impact, natural hazard, and project duration. The case study in the paper relates to the application of multilayer perceptron trained by genetic algorithm for ranking various power plant locations in India. PMID:28331490
Beam shaping in high-power broad-area quantum cascade lasers using optical feedback
Ferré, Simon; Jumpertz, Louise; Carras, Mathieu; Ferreira, Robson; Grillot, Frédéric
2017-01-01
Broad-area quantum cascade lasers with high output powers are highly desirable sources for various applications including infrared countermeasures. However, such structures suffer from strongly deteriorated beam quality due to multimode behavior, diffraction of light and self-focusing. Quantum cascade lasers presenting high performances in terms of power and heat-load dissipation are reported and their response to a nonlinear control based on optical feedback is studied. Applying optical feedback enables to efficiently tailor its near-field beam profile. The different cavity modes are sequentially excited by shifting the feedback mirror angle. Further control of the near-field profile is demonstrated using spatial filtering. The impact of an inhomogeneous gain as well as the influence of the cavity width are investigated. Compared to existing technologies, that are complex and costly, beam shaping with optical feedback is a more flexible solution to obtain high-quality mid-infrared sources. PMID:28287175
Process modelling of biomass conversion to biofuels with combined heat and power.
Sharma, Abhishek; Shinde, Yogesh; Pareek, Vishnu; Zhang, Dongke
2015-12-01
A process model has been developed to study the pyrolysis of biomass to produce biofuel with heat and power generation. The gaseous and solid products were used to generate heat and electrical power, whereas the bio-oil was stored and supplied for other applications. The overall efficiency of the base case model was estimated for conversion of biomass into useable forms of bio-energy. It was found that the proposed design is not only significantly efficient but also potentially suitable for distributed operation of pyrolysis plants having centralised post processing facilities for production of other biofuels and chemicals. It was further determined that the bio-oil quality improved using a multi-stage condensation system. However, the recycling of flue gases coming from combustor instead of non-condensable gases in the pyrolyzer led to increase in the overall efficiency of the process with degradation of bio-oil quality. Copyright © 2015 Elsevier Ltd. All rights reserved.
Shimray, Benjamin A; Singh, Kh Manglem; Khelchandra, Thongam; Mehta, R K
2017-01-01
Every energy system which we consider is an entity by itself, defined by parameters which are interrelated according to some physical laws. In recent year tremendous importance is given in research on site selection in an imprecise environment. In this context, decision making for the suitable location of power plant installation site is an issue of relevance. Environmental impact assessment is often used as a legislative requirement in site selection for decades. The purpose of this current work is to develop a model for decision makers to rank or classify various power plant projects according to multiple criteria attributes such as air quality, water quality, cost of energy delivery, ecological impact, natural hazard, and project duration. The case study in the paper relates to the application of multilayer perceptron trained by genetic algorithm for ranking various power plant locations in India.
Beam shaping in high-power broad-area quantum cascade lasers using optical feedback.
Ferré, Simon; Jumpertz, Louise; Carras, Mathieu; Ferreira, Robson; Grillot, Frédéric
2017-03-13
Broad-area quantum cascade lasers with high output powers are highly desirable sources for various applications including infrared countermeasures. However, such structures suffer from strongly deteriorated beam quality due to multimode behavior, diffraction of light and self-focusing. Quantum cascade lasers presenting high performances in terms of power and heat-load dissipation are reported and their response to a nonlinear control based on optical feedback is studied. Applying optical feedback enables to efficiently tailor its near-field beam profile. The different cavity modes are sequentially excited by shifting the feedback mirror angle. Further control of the near-field profile is demonstrated using spatial filtering. The impact of an inhomogeneous gain as well as the influence of the cavity width are investigated. Compared to existing technologies, that are complex and costly, beam shaping with optical feedback is a more flexible solution to obtain high-quality mid-infrared sources.
Stakeholder analysis: theAndalusian Agency For Healthcare Quality case.
Reyes-Alcázar, Víctor; Casas-Delgado, Marta; Herrera-Usagre, Manuel; Torres-Olivera, Antonio
2012-01-01
The aim of this study was to identify the different groups that can affect or be affected by an agency charged with the promoting and guaranteeing of health care quality in Andalusian region (Spain) and to provide a framework with the stakeholders included in different categories. The study adopted a cross-sectional research design. A case study with structured interviews among Andalusian Agency for Healthcare Quality Steering Committee members was carried out in 2010 to define stakeholders' categories and map the interest groups using 5 attributes: influence, importance, legitimacy, power, and urgency. After identification and categorization, stakeholders were weighted qualitatively according to the attributes of importance and influence using 4 possible levels. A matrix was made with the collected data relating both attributes. Furthermore, 8 different types of stakeholders were identified according to attributes power, legitimacy, and urgency. The study concludes that identifying and classifying stakeholders are fundamental to ensuring the success of an organization that must respond to needs and expectations, especially those of its clients. Moreover, knowing stakeholder linkages can contribute to increase organizational worth. This is essential for organizations basically directed to the provision of services in the scope of health care.
Kumar, S Chaitanya; Samanta, G K; Ebrahim-Zadeh, M
2009-08-03
Characteristics of high-power, narrow-linewidth, continuous-wave (cw) green radiation obtained by simple single-pass second-harmonic-generation (SHG) of a cw ytterbium fiber laser at 1064 nm in the nonlinear crystals of PPKTP and MgO:sPPLT are studied and compared. Temperature tuning and SHG power scaling up to nearly 10 W for input fundamental power levels up to 30 W are performed. Various contributions to thermal effects in both crystals, limiting the SHG conversion efficiency, are studied. Optimal focusing conditions and thermal management schemes are investigated to maximize SHG performance in MgO:sPPLT. Stable green output power and high spatial beam quality with M(2)<1.33 and M(2)<1.34 is achieved in MgO:sPPLT and PPKTP, respectively.
Caffeine ingestion enhances Wingate performance: a meta-analysis.
Grgic, Jozo
2018-03-01
The positive effects of caffeine ingestion on aerobic performance are well-established; however, recent findings are suggesting that caffeine ingestion might also enhance components of anaerobic performance. A commonly used test of anaerobic performance and power output is the 30-second Wingate test. Several studies explored the effects of caffeine ingestion on Wingate performance, with equivocal findings. To elucidate this topic, this paper aims to determine the effects of caffeine ingestion on Wingate performance using meta-analytic statistical techniques. Following a search through PubMed/MEDLINE, Scopus, and SportDiscus ® , 16 studies were found meeting the inclusion criteria (pooled number of participants = 246). Random-effects meta-analysis of standardized mean differences (SMD) for peak power output and mean power output was performed. Study quality was assessed using the modified version of the PEDro checklist. Results of the meta-analysis indicated a significant difference (p = .005) between the placebo and caffeine trials on mean power output with SMD values of small magnitude (0.18; 95% confidence interval: 0.05, 0.31; +3%). The meta-analysis performed for peak power output indicated a significant difference (p = .006) between the placebo and caffeine trials (SMD = 0.27; 95% confidence interval: 0.08, 0.47 [moderate magnitude]; +4%). The results from the PEDro checklist indicated that, in general, studies are of good and excellent methodological quality. This meta-analysis adds on to the current body of evidence showing that caffeine ingestion can also enhance components of anaerobic performance. The results presented herein may be helpful for developing more efficient evidence-based recommendations regarding caffeine supplementation.
ERIC Educational Resources Information Center
Agbola, Frank Wogbe; Lambert, Daniel Kenneth
2010-01-01
From the end of World War II until the early 1970s, vocational education and training (VET) in Australia was surprisingly static and resilient to government-led reform, due to the dominance of industry and union power. Following the oil shocks of 1973 and associated unemployment and declining union power, there have been calls on the federal and…
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.
CALiPER Exploratory Study. Recessed Troffer Lighting
DOE Office of Scientific and Technical Information (OSTI.GOV)
Miller, N. J.; Royer, M. P.; Poplawski, M. E.
This CALiPER study examines the problems and benefits likely to be encountered with LED products intended to replace linear fluorescent lamps. LED dedicated troffers, replacement tubes, and non-tube retrofit kits were evaluated against fluorescent benchmark troffers in a simulated office space for photometric distribution, uniformity of light on the task surface, suitability of light output, flicker, dimming performance, color quality, power quality, safety and certification issues, ease of installation, energy efficiency, and life-cycle cost.
Development of a reactive-dispersive plume model
NASA Astrophysics Data System (ADS)
Kim, Hyun S.; Kim, Yong H.; Song, Chul H.
2017-04-01
A reactive-dispersive plume model (RDPM) was developed in this study. The RDPM can consider two main components of large-scale point source plume: i) turbulent dispersion and ii) photochemical reactions. In order to evaluate the simulation performance of newly developed RDPM, the comparisons between the model-predicted and observed mixing ratios were made using the TexAQS II 2006 (Texas Air Quality Study II 2006) power-plant experiment data. Statistical analyses show good correlation (0.61≤R≤0.92), and good agreement with the Index of Agreement (0.70≤R≤0.95). The chemical NOx lifetimes for two power-plant plumes (Monticello and Welsh power plants) were also estimated.
Li, Ya-Ru; Gibson, Jacqueline MacDonald
2014-09-02
We analyzed sulfur dioxide (SO2) emissions and fine particulate sulfate (PM2.5 sulfate) concentrations in the southeastern United States during 2002-2012, in order to evaluate the health impacts in North Carolina (NC) of the NC Clean Smokestacks Act of 2002. This state law required progressive reductions (beyond those mandated by federal rules) in pollutant emissions from NC's coal-fired power plants. Although coal-fired power plants remain NC's leading SO2 source, a trend analysis shows significant declines in SO2 emissions (-20.3%/year) and PM2.5 sulfate concentrations (-8.7%/year) since passage of the act. Emissions reductions were significantly greater in NC than in neighboring states, and emissions and PM2.5 sulfate concentration reductions were highest in NC's piedmont region, where 9 of the state's 14 major coal-fired power plants are located. Our risk model estimates that these air quality improvements decreased the risk of premature death attributable to PM2.5 sulfate in NC by about 63%, resulting in an estimated 1700 (95% CI: 1500, 1800) deaths prevented in 2012. These findings lend support to recent studies predicting that implementing the proposed federal Cross-State Air Pollution Rule (recently upheld by the U.S. Supreme Court) could substantially decrease U.S. premature deaths attributable to coal-fired power plant emissions.
Working Toward Policy-Relevant Air Quality Emissions Scenarios
NASA Astrophysics Data System (ADS)
Holloway, T.
2010-12-01
Though much work has been done to develop accurate chemical emission inventories, few publicly available inventories are appropriate for realistic policy analysis. Emissions from the electricity and transportation sectors, in particular, respond in complex ways to policy, technology, and energy use change. Many widely used inventories, such as the EPA National Emissions Inventory, are well-suited for modeling current air quality, but do not have the specificity needed to address "what if?" questions. Changes in electricity demand, fuel prices, new power sources, and emission controls all influence the emissions from regional power production, requiring a plant-by-plant assessment to capture the spatially explicit impacts. Similarly, land use, freight distribution, or driving behavior will yield differentiated transportation emissions for urban areas, suburbs, and rural highways. We here present results from three recent research projects at the University of Wisconsin—Madison, where bottom-up emission inventories for electricity, freight transport, and urban vehicle use were constructed to support policy-relevant air quality research. These three studies include: 1) Using the MyPower electricity dispatch model to calculate emissions and air quality impacts of Renewable Portfolio Standards and other carbon-management strategies; 2) Using advanced vehicle and commodity flow data from the Federal Highway Administration to evaluate the potential to shift commodities from truck to rail (assuming expanded infrastructure), and assess a range of alternative fuel suggestions; and 3) Working with urban planners to connect urban density with vehicle use to evaluate the air quality impacts of smart-growth in major Midwest cities. Drawing on the results of these three studies, and on challenges overcome in their execution, we discuss the current state of policy-relevant emission dataset generation, as well as techniques and attributes that need to be further refined in order to meet the increasingly intricate demands of both advanced air quality models and more realistic and relevant policy scenarios.
Power Quality Improvement in Induction Furnace by Harmonic Reduction Using Dynamic Voltage Restorer
NASA Astrophysics Data System (ADS)
Saggu, Tejinder Singh; Singh, Lakhwinder
2016-06-01
Induction furnaces are used in wide quantity under different capacities for annual production of around 25 million tons of iron and steel in India. It plays a vital role in various manufacturing processes around the world for melting different types of metal scraps i. e. Copper, Cast Iron, Aluminium, Steel, Brass, Bronze, Silicon, Gold, Silver etc. which are further used in many other industrial applications. The induction furnace causes a huge disturbance to the utility and nearby consumers during its operation due to its non-linear characteristics. This is a serious phenomenon responsible for power quality degradation in the power system. This paper presents methodology to improve the power quality degradation caused by induction furnace using Dynamic Voltage Restorer (DVR) which is a type of custom power device. The real time data has been taken from an industry employing induction furnace for production of ingots from scrap material. The experimental readings are measured using power quality analyser equipment. The simulation of whole plant is done by analysing this same data and the simulation results are compared with actual onsite results. Then, solution methodology using DVR is presented which revealed that the implementation of DVR is an effective solution for voltage sag mitigation and harmonics improvement in induction furnace.
A real time study on condition monitoring of distribution transformer using thermal imager
NASA Astrophysics Data System (ADS)
Mariprasath, T.; Kirubakaran, V.
2018-05-01
The transformer is one of the critical apparatus in the power system. At any cost, a few minutes of outages harshly influence the power system. Hence, prevention-based maintenance technique is very essential. The continuous conditioning and monitoring technology significantly increases the life span of the transformer, as well as reduces the maintenance cost. Hence, conditioning and monitoring of transformer's temperature are very essential. In this paper, a critical review has been made on various conditioning and monitoring techniques. Furthermore, a new method, hot spot indication technique, is discussed. Also, transformer's operating condition is monitored by using thermal imager. From the thermal analysis, it is inferred that major hotspot locations are appearing at connection lead out; also, the bushing of the transformer is the very hottest spot in transformer, so monitoring the level of oil is essential. Alongside, real time power quality analysis has been carried out using the power analyzer. It shows that industrial drives are injecting current harmonics to the distribution network, which causes the power quality problem on the grid. Moreover, the current harmonic limit has exceeded the IEEE standard limit. Hence, the adequate harmonics suppression technique is need an hour.
Calibrating Parameters of Power System Stability Models using Advanced Ensemble Kalman Filter
DOE Office of Scientific and Technical Information (OSTI.GOV)
Huang, Renke; Diao, Ruisheng; Li, Yuanyuan
With the ever increasing penetration of renewable energy, smart loads, energy storage, and new market behavior, today’s power grid becomes more dynamic and stochastic, which may invalidate traditional study assumptions and pose great operational challenges. Thus, it is of critical importance to maintain good-quality models for secure and economic planning and real-time operation. Following the 1996 Western Systems Coordinating Council (WSCC) system blackout, North American Electric Reliability Corporation (NERC) and Western Electricity Coordinating Council (WECC) in North America enforced a number of policies and standards to guide the power industry to periodically validate power grid models and calibrate poor parametersmore » with the goal of building sufficient confidence in model quality. The PMU-based approach using online measurements without interfering with the operation of generators provides a low-cost alternative to meet NERC standards. This paper presents an innovative procedure and tool suites to validate and calibrate models based on a trajectory sensitivity analysis method and an advanced ensemble Kalman filter algorithm. The developed prototype demonstrates excellent performance in identifying and calibrating bad parameters of a realistic hydro power plant against multiple system events.« less
Economic analysis of municipal wastewater utilization for thermoelectric power production
DOE Office of Scientific and Technical Information (OSTI.GOV)
Safari, I.; Walker, M.; Abbasian, J.
2011-01-01
The thermoelectric power industry in the U.S. uses a large amount of freshwater. The large water demand is increasingly a problem, especially for new power plant development, as availability of freshwater for new uses diminishes in the United States. Reusing non-traditional water sources, such as treated municipal wastewater, provides one option to mitigate freshwater usage in the thermoelectric power industry. The amount of freshwater withdrawal that can be displaced with non-traditional water sources at a particular location requires evaluation of the water management and treatment requirements, considering the quality and abundance of the non-traditional water sources. This paper presents themore » development of an integrated costing model to assess the impact of degraded water treatment, as well as the implications of increased tube scaling in the main condenser. The model developed herein is used to perform case studies of various treatment, condenser cleaning and condenser configurations to provide insight into the ramifications of degraded water use in the cooling loops of thermoelectric power plants. Further, this paper lays the groundwork for the integration of relationships between degraded water quality, scaling characteristics and volatile emission within a recirculating cooling loop model.« less
NASA Astrophysics Data System (ADS)
Shen, Yijie; Gong, Mali; Fu, Xing
2018-05-01
Beam quality improvement with pump power increasing in an end-pumped laser oscillator is experimentally realized for the first time, to the best of our knowledge. The phenomenon is caused by the population-dynamic-coupled combined guiding effect, a comprehensive theoretical model of which has been well established, in agreement with the experimental results. Based on an 888 nm in-band dual-end-pumped oscillator using four tandem Nd:YVO4 crystals, the output beam quality of M^2= 1.1/1.1 at the pump power of 25 W is degraded to M^2 = 2.5/1.8 at 75 W pumping and then improved to M^2= 1.8/1.3 at 150 W pumping. The near-TEM_{00} mode is obtained with the highest continuous-wave output power of 72.1 W and the optical-to-optical efficiency of 48.1%. This work demonstrates great potential to further scale the output power of end-pumped laser oscillator while keeping good beam quality.
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.
Operation of a pond-cooler: the case of Berezovskaya GRES-1
NASA Astrophysics Data System (ADS)
Morozova, O. G.; Kamoza, T. L.; Koyupchenko, I. N.; Savelyev, A. S.; Pen, R. Z.; Veselkova, N. S.; Kudryavtsev, M. D.
2017-08-01
Pond-coolers at heat and nuclear power stations are natural-technological systems, so the program of their monitoring should include the effect made by the SRPS (state regional power station) on the pond ecosystem, including thermal discharge of cooling water. The objectives of this study were development and implementation of a monitoring program for the cooling pond of Berezovskaya SRPS-1 on the chemical and biological water quality indicators and identification of patterns of the thermal and hydrochemical regime when operating the progressive power plant (from 1996 to 2015). The quality of the cooling water of the pond-cooler BGRES-1 was studied under full-scale conditions by selecting and analyzing the water samples of the pond in accordance with the principles of complexity, systematic observation, and consistency of timing their conduct with the characteristic hydrological phases. Processing of the obtained array of monitoring data by methods of mathematical statistics makes it possible to identify the main factors affecting the water quality of the pond. The data on water quality obtained during their monitoring and mathematical processing over a long time interval are the scientific basis for forecasting the ecological state of the pond, which is necessary to economically ensure the efficient energy production and safety of water use. Recommendations proposed by these authors, including those partially already implemented, have been to prevent the development of eutrophication processes in the pond-cooler: the construction of a dam that cuts off the main peat massif and cleaning the river banks forming the cooling pond.
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 receive quality management and continuous surveys, and comparison districts-only continuous surveys. Discussion EQUIP is a district-scale, proof-of-concept study that evaluates a quality management approach for maternal and newborn health including communities, health facilities, and district health managers, supported by high-quality data from independent continuous household and health facility surveys. The study will generate robust evidence about the effectiveness of quality management and will inform future nationwide implementation approaches for health system strengthening in low-resource settings. Trial registration PACTR201311000681314 PMID:24690284
Hanson, Claudia; Waiswa, Peter; Marchant, Tanya; Marx, Michael; Manzi, Fatuma; Mbaruku, Godfrey; Rowe, Alex; Tomson, Göran; Schellenberg, Joanna; Peterson, Stefan
2014-04-02
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. 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 receive quality management and continuous surveys, and comparison districts-only continuous surveys. EQUIP is a district-scale, proof-of-concept study that evaluates a quality management approach for maternal and newborn health including communities, health facilities, and district health managers, supported by high-quality data from independent continuous household and health facility surveys. The study will generate robust evidence about the effectiveness of quality management and will inform future nationwide implementation approaches for health system strengthening in low-resource settings. PACTR201311000681314.
Environmental review of Potomac Electric Power Company's proposed Station H Element I
DOE Office of Scientific and Technical Information (OSTI.GOV)
Not Available
1990-04-01
The report has been conducted to evaluate the potential impacts to environmental and cultural resources from the proposed construction and operation of Element I (the combustion turbine portion) of the Station H power plant facility at Potomac Electric Power Company's Dickerson site. This review also presents an evaluation of air quality impacts of Elements I and II (combustion turbine and combined cycle components of the facility) and an assessment of compliance with state and Federal air quality regulations (primarily the ambient air quality standards and the air quality impact requirements of PSD regulations). Results of the Environmental Review analysis aremore » used as the basis for establishing preliminary recommended licensing conditions for operating the proposed facility. These recommendations are also included in the report.« less
Mokhtar, Mutahharah M; Taib, Rozainee M; Hassim, Mimi H
2014-08-01
The Proposed New Environmental Quality (Clean Air) Regulation 201X (Draft), which replaces the Malaysia Environmental Quality (Clean Air) 1978, specifies limits to additional pollutants from power generation using fossil fuel. The new pollutants include Hg, HCl, and HF with limits of 0.03, 100, and 15 mg/N-m3 at 6% O2, respectively. These pollutants are normally present in very small concentrations (known as trace elements [TEs]), and hence are often neglected in environmental air quality monitoring in Malaysia. Following the enactment of the new regulation, it is now imperative to understand the TEs behavior and to assess the capability of the existing abatement technologies to comply with the new emission limits. This paper presents the comparison of TEs behavior of the most volatile (Hg, Cl, F) and less volatile (As, Be, Cd, Cr, Ni, Se, Pb) elements in subbituminous and bituminous coal and coal combustion products (CCP) (i.e., fly ash and bottom ash) from separate firing of subbituminous and bituminous coal in a coal-fired power plant in Malaysia. The effect of air pollution control devices configuration in removal of TEs was also investigated to evaluate the effectiveness of abatement technologies used in the plant. This study showed that subbituminous and bituminous coals and their CCPs have different TEs behavior. It is speculated that ash content could be a factor for such diverse behavior In addition, the type of coal and the concentrations of TEs in feed coal were to some extent influenced by the emission of TEs in flue gas. The electrostatic precipitator (ESP) and seawater flue gas desulfurization (FGD) used in the studied coal-fired power plant were found effective in removing TEs in particulate and vapor form, respectively, as well as complying with the new specified emission limits. Implications: Coals used by power plants in Peninsular Malaysia come from the same supplier (Tenaga Nasional Berhad Fuel Services), which is a subsidiary of the Malaysia electricity provider (Tenaga Nasional Berhad). Therefore, this study on trace elements behavior in a coal-fired power plant in Malaysia could represent emission from other plants in Peninsular Malaysia. By adhering to the current coal specifications and installation of electrostatic precipitator (ESP) and flue gas desulfurization, the plants could comply with the limits specified in the Malaysian Department of Environment (DOE) Scheduled Waste Guideline for bottom ash and fly ash and the Proposed New Environmental Quality (Clean Air) Regulation 201X (Draft).
Grutsch, James F; Ferrans, Carol; Wood, Patricia A; Du-Quiton, Jovelyn; Quiton, Dinah Faith T; Reynolds, Justin L; Ansell, Christine M; Oh, Eun Young; Daehler, Mary Ann; Levin, Robert D; Braun, Donald P; Gupta, Digant; Lis, Christopher G; Hrushesky, William J M
2011-05-23
Cancer patients routinely develop symptoms consistent with profound circadian disruption, which causes circadian disruption diminished quality of life. This study was initiated to determine the relationship between the severity of potentially remediable cancer-associated circadian disruption and quality of life among patients with advanced lung cancer. We concurrently investigated the relationship between the circadian rhythms of 84 advanced lung cancer patients and their quality of life outcomes as measured by the EORTC QLQ C30 and Ferrans and Powers QLI. The robustness and stability of activity/sleep circadian daily rhythms were measured by actigraphy. Fifty three of the patients in the study were starting their definitive therapy following diagnosis and thirty one patients were beginning second-line therapy. Among the patients who failed prior therapy, the median time between completing definitive therapy and baseline actigraphy was 4.3 months, (interquartile range 2.1 to 9.8 months). We found that circadian disruption is universal and severe among these patients compared to non-cancer-bearing individuals. We found that each of these patient's EORTC QLQ C30 domain scores revealed a compromised capacity to perform the routine activities of daily life. The severity of several, but not all, EORTC QLQ C30 symptom items correlate strongly with the degree of individual circadian disruption. In addition, the scores of all four Ferrans/Powers QLI domains correlate strongly with the degree of circadian disruption. Although Ferrans/Powers QLI domain scores show that cancer and its treatment spared these patients' emotional and psychological health, the QLI Health/Function domain score revealed high levels of patients' dissatisfaction with their health which is much worse when circadian disruption is severe. Circadian disruption selectively affects specific Quality of Life domains, such as the Ferrans/Powers Health/Function domain, and not others, such as EORTC QLQ C30 Physical Domain. These data suggest the testable possibility that behavioral, hormonal and/or light-based strategies to improve circadian organization may help patients suffering from advanced lung cancer to feel and function better.
NASA Astrophysics Data System (ADS)
Hoover, F. A.; Bowling, L. C.; Prokopy, L. S.
2015-12-01
Urban stormwater is an on-going management concern in municipalities of all sizes. In both combined or separated sewer systems, pollutants from stormwater runoff enter the natural waterway system during heavy rain events. Urban flooding during frequent and more intense storms are also a growing concern. Therefore, stormwater best-management practices (BMPs) are being implemented in efforts to reduce and manage stormwater pollution and overflow. The majority of BMP water quality studies focus on the small-scale, individual effects of the BMP, and the change in water quality directly from the runoff of these infrastructures. At the watershed scale, it is difficult to establish statistically whether or not these BMPs are making a difference in water quality, given that watershed scale monitoring is often costly and time consuming, relying on significant sources of funds, which a city may not have. Hence, there is a need to quantify the level of sampling needed to detect the water quality impact of BMPs at the watershed scale. In this study, a power analysis was performed on data from an urban watershed in Lafayette, Indiana, to determine the frequency of sampling required to detect a significant change in water quality measurements. Using the R platform, results indicate that detecting a significant change in watershed level water quality would require hundreds of weekly measurements, even when improvement is present. The second part of this study investigates whether the difficulty in demonstrating water quality change represents a barrier to adoption of stormwater BMPs. Semi-structured interviews of community residents and organizations in Chicago, IL are being used to investigate residents understanding of water quality and best management practices and identify their attitudes and perceptions towards stormwater BMPs. Second round interviews will examine how information on uncertainty in water quality improvements influences their BMP attitudes and perceptions.
Quality evaluation on an e-learning system in continuing professional education of nurses.
Lin, I-Chun; Chien, Yu-Mei; Chang, I-Chiu
2006-01-01
Maintaining high quality in Web-based learning is a powerful means of increasing the overall efficiency and effectiveness of distance learning. Many studies have evaluated Web-based learning but seldom evaluate from the information systems (IS) perspective. This study applied the famous IS Success model in measuring the quality of a Web-based learning system using a Web-based questionnaire for data collection. One hundred and fifty four nurses participated in the survey. Based on confirmatory factor analysis, the variables of the research model fit for measuring the quality of a Web-based learning system. As Web-based education continues to grow worldwide, the results of this study may assist the system adopter (hospital executives), the learner (nurses), and the system designers in making reasonable and informed judgments with regard to the quality of Web-based learning system in continuing professional education.
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.
NASA Astrophysics Data System (ADS)
Tingberg, Anders Martin
Optimisation in diagnostic radiology requires accurate methods for determination of patient absorbed dose and clinical image quality. Simple methods for evaluation of clinical image quality are at present scarce and this project aims at developing such methods. Two methods are used and further developed; fulfillment of image criteria (IC) and visual grading analysis (VGA). Clinical image quality descriptors are defined based on these two methods: image criteria score (ICS) and visual grading analysis score (VGAS), respectively. For both methods the basis is the Image Criteria of the ``European Guidelines on Quality Criteria for Diagnostic Radiographic Images''. Both methods have proved to be useful for evaluation of clinical image quality. The two methods complement each other: IC is an absolute method, which means that the quality of images of different patients and produced with different radiographic techniques can be compared with each other. The separating power of IC is, however, weaker than that of VGA. VGA is the best method for comparing images produced with different radiographic techniques and has strong separating power, but the results are relative, since the quality of an image is compared to the quality of a reference image. The usefulness of the two methods has been verified by comparing the results from both of them with results from a generally accepted method for evaluation of clinical image quality, receiver operating characteristics (ROC). The results of the comparison between the two methods based on visibility of anatomical structures and the method based on detection of pathological structures (free-response forced error) indicate that the former two methods can be used for evaluation of clinical image quality as efficiently as the method based on ROC. More studies are, however, needed for us to be able to draw a general conclusion, including studies of other organs, using other radiographic techniques, etc. The results of the experimental evaluation of clinical image quality are compared with physical quantities calculated with a theoretical model based on a voxel phantom, and correlations are found. The results demonstrate that the computer model can be a useful toot in planning further experimental studies.
NASA Astrophysics Data System (ADS)
Khayyat, Abdulkareem Hawta Abdullah Kak Ahmed
Scope and Method of Study: Most developing countries, including Iraq, have very poor wind data. Existing wind speed measurements of poor quality may therefore be a poor guide to where to look for the best wind resources. The main focus of this study is to examine how effectively a GIS spatial model estimates wind power potential in regions where high-quality wind data are very scarce, such as Iraq. The research used a mixture of monthly and hourly wind data from 39 meteorological stations. The study applied spatial analysis statistics and GIS techniques in modeling wind power potential. The model weighted important human, environmental and geographic factors that impact wind turbine siting, such as roughness length, land use⪉nd cover type, airport locations, road access, transmission lines, slope and aspect. Findings and Conclusions: The GIS model provided estimations for wind speed and wind power density and identified suitable areas for wind power projects. Using a high resolution (30*30m) digital elevation model DEM improved the GIS wind suitability model. The model identified areas suitable for wind farm development on different scales. The model showed that there are many locations available for large-scale wind turbines in the southern part of Iraq. Additionally, there are many places in central and northern parts (Kurdistan Region) for smaller scale wind turbine placement.
Thin disk laser with unstable resonator and reduced output coupler
NASA Astrophysics Data System (ADS)
Gavili, Anwar; Shayganmanesh, Mahdi
2018-05-01
In this paper, feasibility of using unstable resonator with reduced output coupling in a thin disk laser is studied theoretically. Unstable resonator is modeled by wave-optics using Collins integral and iterative method. An Yb:YAG crystal with 250 micron thickness is considered as a quasi-three level active medium and modeled by solving rate equations of energy levels populations. The amplification of laser beam in the active medium is calculated based on the Beer-Lambert law and Rigrod method. Using generalized beam parameters method, laser beam parameters like, width, divergence, M2 factor, output power as well as near and far-field beam profiles are calculated for unstable resonator. It is demonstrated that for thin disk laser (with single disk) in spite of the low thickness of the disk which leads to low gain factor, it is possible to use unstable resonator (with reduced output coupling) and achieve good output power with appropriate beam quality. Also, the behavior of output power and beam quality versus equivalent Fresnel number is investigated and optimized value of output coupling for maximum output power is achieved.
Quality Assurance in Higher Education: Reflection, Criticism, and Change
ERIC Educational Resources Information Center
Yingqiang, Zhang; Yongjian, Su
2016-01-01
Quality assurance in modern higher education is both an accountability-oriented ideology and a technological method. It has also evolved into a increasingly rationalist and professionalized power mechanism. Its advocacy of compliance, technological mythology, and imbalance between power and responsibility are inherent disadvantages of higher…
Amiri, Mostafa; Nafissi, Shahriar; Jamal-Omidi, Shirin; Amiri, Motahareh; Fatehi, Farzad
2014-12-01
Human T-lymphotropic virus type 1 has been implicated in human T-lymphotropic virus type 1-associated myelopathy/tropical spastic paraparesis (HAM/TSP). Regarding its endemicity in Iran and the role of repetitive transcranial magnetic stimulation in reducing spasticity, we decided to evaluate the efficacy of repetitive transcranial magnetic stimulation in reducing spasticity (as primary outcome) and pain, muscle power, and quality of life (as secondary outcomes) in patients suffering from HAM/TSP. In this pretest-posttest study, nine definite patients with HAM/TSP (according to WHO guidelines) were recruited. All patients underwent five consecutive daily sessions of active repetitive transcranial magnetic stimulation (each session consisting of 20 trains of 10 pulses at 5 Hz and an intensity of 90% of resting motor threshold for the biceps brachii muscle). Main outcome measures including spasticity (by modified Ashworth scale), pain (by visual analog scale), muscle power, and quality of life (by SF 36) were measured before the study and days 5, 7, 30 after the termination of the sessions. Seven (77.8%) females and 2 (22.2%) males were recruited with the mean age of 52 ± 12.67 years, and the mean duration of the disease was 5 ± 3.94. Comparison of the repeated measures showed a statistically significant decrease in pain and spasticity in lower limbs. The decrement in spasticity was persistent even 30 days after the intervention; however, the pain reduction was seen only 5 days after the procedure. No change in quality of life, and muscle power was detected. It seems that repetitive transcranial magnetic stimulation could decrease spasticity and pain in patients with HAM/TSP, and this effect could persistently continue by 1 month, but it did not influence patients' muscle power and quality of life, and it could be used as an adjuvant therapy in patients suffering from human T-lymphotropic virus type 1-associated HAM/TSP.
Wang, Liqiang; Li, Pengfei; Yu, Shaocai; Mehmood, Khalid; Li, Zhen; Chang, Shucheng; Liu, Weiping; Rosenfeld, Daniel; Flagan, Richard C; Seinfeld, John H
2018-01-17
Widespread economic growth in China has led to increasing episodes of severe air pollution, especially in major urban areas. Thermal power plants represent a particularly important class of emissions. Here we present an evaluation of the predicted effectiveness of a series of recently proposed thermal power plant emission controls in the Beijing-Tianjin-Hebei (BTH) region on air quality over Beijing using the Community Multiscale Air Quality(CMAQ) atmospheric chemical transport model to predict CO, SO 2 , NO 2 , PM 2.5 , and PM 10 levels. A baseline simulation of the hypothetical removal of all thermal power plants in the BTH region is predicted to lead to 38%, 23%, 23%, 24%, and 24% reductions in current annual mean levels of CO, SO 2 , NO 2 , PM 2.5 , and PM 10 in Beijing, respectively. Similar percentage reductions are predicted in the major cities in the BTH region. Simulations of the air quality impact of six proposed thermal power plant emission reduction strategies over the BTH region provide an estimate of the potential improvement in air quality in the Beijing metropolitan area, as a function of the time of year.
An integrated modeling method for wind turbines
NASA Astrophysics Data System (ADS)
Fadaeinedjad, Roohollah
To study the interaction of the electrical, mechanical, and aerodynamic aspects of a wind turbine, a detailed model that considers all these aspects must be used. A drawback of many studies in the area of wind turbine simulation is that either a very simple mechanical model is used with a detailed electrical model, or vice versa. Hence the interactions between electrical and mechanical aspects of wind turbine operation are not accurately taken into account. In this research, it will be shown that a combination of different simulation packages, namely TurbSim, FAST, and Simulink can be used to model the aerodynamic, mechanical, and electrical aspects of a wind turbine in detail. In this thesis, after a review of some wind turbine concepts and software tools, a simulation structure is proposed for studying wind turbines that integrates the mechanical and electrical components of a wind energy conversion device. Based on the simulation structure, a comprehensive model for a three-bladed variable speed wind turbine with doubly-fed induction generator is developed. Using the model, the impact of a voltage sag on the wind turbine tower vibration is investigated under various operating conditions such as power system short circuit level, mechanical parameters, and wind turbine operating conditions. It is shown how an electrical disturbance can cause more sustainable tower vibrations under high speed and turbulent wind conditions, which may disrupt the operation of pitch control system. A similar simulation structure is used to model a two-bladed fixed speed wind turbine with an induction generator. An extension of the concept is introduced by adding a diesel generator system. The model is utilized to study the impact of the aeroelastic aspects of wind turbine (i.e. tower shadow, wind shears, yaw error, turbulence, and mechanical vibrations) on the power quality of a stand-alone wind-diesel system. Furthermore, an IEEE standard flickermeter model is implemented in a Simulink environment to study the flicker contribution of the wind turbine in the wind-diesel system. By using a new wind power plant representation method, a large wind farm (consisting of 96 fixed speed wind turbines) is modelled to study the power quality of wind power system. The flicker contribution of wind farm is also studied with different wind turbine numbers, using the flickermeter model. Keywords. Simulink, FAST, TurbSim, AreoDyn, wind energy, doubly-fed induction generator, variable speed wind turbine, voltage sag, tower vibration, power quality, flicker, fixed speed wind turbine, wind shear, tower shadow, and yaw error.
[The quality of sibling relation who have experienced family transitions and those who have not].
Simard, Marie; Beaudry, Madeleine; Drapeau, Sylvie; Nadeau, France; Charbonneau, Cécile
2002-01-01
In this study, similarities and differences in sibling relationships between children who have experienced family transitions and those who have not are examined. Comparisons are made between children who live in intact families, those whose parents have separated, and those who live in substitute care regarding the quality of their relationships with one of their siblings. More specifically, 4 dimensions describing the quality of sibling relationships are compared: Warmth/Closeness, Conflict, Relative Status/Power, and Rivalry (Furman & Buhrmester, 1985). The sample is made up of 3 groups of children (N = 158) aged between 8 and 12 years old: children living in intact families (n = 101), children who have experienced parental separation (n = 35), and children living in substitute care (n = 22). Results indicate differences on dimensions of Warmth/Closeness, Conflict, and Relative Status/Power. Different patterns of responses between the children who have experienced family transitions and those who have not are observed for the dimensions of Conflict and Power. The significant difference observed between the groups for the dimension of Warmth appears difficult to explain. Discussion of these results emphasizes the importance of the relationship between brothers and sisters experiencing family transition.
When subjective experiences matter: power increases reliance on the ease of retrieval.
Weick, Mario; Guinote, Ana
2008-06-01
Past research on power focused exclusively on declarative knowledge and neglected the role of subjective experiences. Five studies tested the hypothesis that power increases reliance on the experienced ease or difficulty that accompanies thought generation. Across a variety of targets, such as attitudes, leisure-time satisfaction, and stereotyping, and with different operationalizations of power, including priming, trait dominance, and actual power in managerial contexts, power consistently increased reliance on the ease of retrieval. These effects remained 1 week later and were not mediated by mood, quality of the retrieved information, or number of counterarguments. These findings indicate that powerful individuals construe their judgments on the basis of momentary subjective experiences and do not necessarily rely on core attitudes or prior knowledge, such as stereotypes. (PsycINFO Database Record (c) 2008 APA, all rights reserved).
Power and the objectification of social targets.
Gruenfeld, Deborah H; Inesi, M Ena; Magee, Joe C; Galinsky, Adam D
2008-07-01
Objectification has been defined historically as a process of subjugation whereby people, like objects, are treated as means to an end. The authors hypothesized that objectification is a response to social power that involves approaching useful social targets regardless of the value of their other human qualities. Six studies found that under conditions of power, approach toward a social target was driven more by the target's usefulness, defined in terms of the perceiver's goals, than in low-power and baseline conditions. This instrumental response to power, which was linked to the presence of an active goal, was observed using multiple instantiations of power, different measures of approach, a variety of goals, and several types of instrumental and noninstrumental target attributes. Implications for research on the psychology of power, automatic goal pursuit, and self-objectification theory are discussed.
Siblings' Power and Influence in Polyadic Family Conflict During Early Childhood.
Della Porta, Sandra; Howe, Nina
2017-06-01
This study examined sibling behavior during polyadic family conflicts (involving three or more family members) by identifying operational conflict elements (i.e., roles, topic), power strategies, effective influence of power, and social domain argumentation. Polyadic conflict sequences (n = 210) were identified in 35/39 families with two siblings (aged 4 and 6) and their parents observed at home. The dominant conflict topic, siblings' use of power and power strategy executed in relation to social domain argumentation, revealed unique qualities of conflict in the polyadic family context; effective use of power strategies to facilitate favorable outcomes differed by sibling birth order. Our account presents a nuanced view of the intricacies of polyadic family conflict, which provides unique opportunities for children's learning and socialization by siblings and parents. © 2017 Wiley Periodicals, Inc.
Operational Results From a High Power Alternator Test Bed
NASA Technical Reports Server (NTRS)
Birchenough, Arthur; Hervol, David
2007-01-01
The Alternator Test Unit (ATU) in the Lunar Power System Facility (LPSF) located at the NASA Glenn Research Center (GRC) in Cleveland, Ohio was used to simulate the operating conditions and evaluate the performance of the ATU and its interaction with various LPSF components in accordance with the current Fission Surface Power System (FSPS) requirements. The testing was carried out at the breadboard development level. These results successfully demonstrated excellent ATU power bus characteristics and rectified user load power quality during steady state and transient conditions. Information gained from this work could be used to assist the design and primary power quality considerations for a possible future FSPS. This paper describes the LPSF components and some preliminary test results.
Schilling, Birgit; Gibson, Bradford W.; Hunter, Christie L.
2017-01-01
Data-independent acquisition is a powerful mass spectrometry technique that enables comprehensive MS and MS/MS analysis of all detectable species, providing an information rich data file that can be mined deeply. Here, we describe how to acquire high-quality SWATH® Acquisition data to be used for large quantitative proteomic studies. We specifically focus on using variable sized Q1 windows for acquisition of MS/MS data for generating higher specificity quantitative data. PMID:28188533
NASA Astrophysics Data System (ADS)
Saari, R.; Selin, N. E.
2015-12-01
We examine the effect of state, regional, and national cooperation on the costs and air quality co-benefits of a policy to limit the carbon intensity of existing electricity generation. Electricity generation is a significant source of both greenhouse gases and air pollutant emissions that harm human health. Previous studies have shown that air quality co-benefits can be substantial compared to the costs of limiting carbon emissions in the energy system. The EPA's proposed Clean Power Plan seeks to impose carbon intensity limits for each state, but allows states to cooperate in order to meet combined limits. We explore how such cooperation might produce trade-offs between lower costs, widespread pollution reductions, and local reductions. We employ a new state-level model of the US energy system and economy to examine the costs and emissions as states reduce demand or deploy cleaner generation. We use an advanced air quality impacts modeling system, including SMOKE, CAMx, and BenMAP, to estimate health-related air quality co-benefits and compare these to costs under different levels of cooperation. We draw conclusions about the potential impacts of cooperation on economic welfare at various scales.
Testing the hospital value proposition: an empirical analysis of efficiency and quality.
Huerta, Timothy R; Ford, Eric W; Peterson, Lori T; Brigham, Keith H
2008-01-01
To assess the relationship between hospitals' X-inefficiency levels and overall care quality based on the National Quality Forum's 27 safe practices score and to improve the analytic strategy for assessing X-inefficiency. The 2005 versions of the American Hospital Association and Leapfrog Group's annual surveys were the basis of the study. Additional case mix indices and market variables were drawn from the Centers for Medicare and Medicaid Services data sources and the Area Resource File. Data envelopment analysis was used to determine hospitals' X-inefficiency scores relative to their market-level competitors. Regression was used to assess the relationship between X-inefficiency and quality, controlling for organizational and market characteristics. Expenses (total and labor expenditures), case-mix-adjusted admissions, length of stay, and licensed beds defined the X-inefficiency function. The overall National Quality Forum's safe practice score, health maintenance organization penetration, market share, and teaching status served as independent control variables in the regression. The National Quality Forum's safe practice scores are significantly and positively correlated to hospital X-inefficiency levels (beta = .105, p < or = .05). The analysis of the value proposition had very good explanatory power (adjusted R(2) = .414; p < or = .001; df = 7, 265). Contrary to earlier findings, health maintenance organization penetration and being a teaching hospital were positively related to X-inefficiency. Similar with others' findings, greater market share and for-profit ownership were negatively associated with X-inefficiency. Measurement of overall hospital quality is improving but can still be made better. Nevertheless, the National Quality Forum's measure is significantly related to efficiency and could be used to create differential pay-for-performance programs. A market-segmented analytic strategy for studying hospitals' efficiency yields results with a high degree of explanatory power.
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.
Control of Disturbing Loads in Residential and Commercial Buildings via Geometric Algebra
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
Control of disturbing loads in residential and commercial buildings via geometric algebra.
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.
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.
Best Practices: Power Quality and Integrated Testing at JSC
NASA Technical Reports Server (NTRS)
Davis, Lydia
2018-01-01
This presentation discusses Best Practices for Power Quality and Integrated Testing at JSC in regards to electrical systems. These high-level charts include mostly generic information; however, a specific issue is discussed involving flight hardware that could have been discovered prior to flight with an integrated test.
NASA Technical Reports Server (NTRS)
Cornwell, Donald M., Jr.; Saif, Babak N.
1991-01-01
The spatial pointing angle and far field beamwidth of a high-power semiconductor laser are characterized as a function of CW power and also as a function of temperature. The time-averaged spatial pointing angle and spatial lobe width were measured under intensity-modulated conditions. The measured pointing deviations are determined to be well within the pointing requirements of the NASA Laser Communications Transceiver (LCT) program. A computer-controlled Mach-Zehnder phase-shifter interferometer is used to characterize the wavefront quality of the laser. The rms phase error over the entire pupil was measured as a function of CW output power. Time-averaged measurements of the wavefront quality are also made under intensity-modulated conditions. The measured rms phase errors are determined to be well within the wavefront quality requirements of the LCT program.
NASA Technical Reports Server (NTRS)
1979-01-01
Contents: project plan summary; project and mission objectives; related studies and technology support activities; technical summary; management; procurement approach; project definition items and schedule; resources; management review; controlled items; and safety, reliability, and quality assurance.
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 (PM 2.5 ), 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 PM 2.5 concentration. Both PM 2.5 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 PM 2.5 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 PM 2.5 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 PM 2.5 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 PM 2.5 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 PM 2.5 at 12 EPA ground stations; further research on PM 2.5 emissions from unconventional natural gas extraction is needed. With many coal-fired power plants scheduled to close across the United States in the coming years, there is interest in the potential impact on regional PM 2.5 concentrations. In southwestern Pennsylvania, recent coal-fired power plant closings were coupled with a boom in unconventional natural gas extraction. Natural gas is currently seen as an economically viable bridge fuel between coal and renewable energy. This study provides policymakers with more information on the potential ambient concentration changes associated with coal-fired power plant closings as the nation's energy reliance shifts toward natural gas.
Zeng, Jinghai; Xing, Min; Hou, Min; England, Glenn C; Yan, Jing
2018-04-27
The Beijing Municipal Environmental Protection Bureau (EPB) is considering strengthening the Emission Standard of Air Pollutants for Stationary Gas Turbines, originally published in 2011 (DB11/847-2011), with a focus on reducing nitrogen oxides (NOx) emissions. A feasibility study was conducted to evaluate the current operation of 12 existing combined-cycle gas turbine power plants and the design of two new plants in Beijing and their emission reduction potential, in comparison with a state-of-the-art power plant in California. The study found that best management practices (BMPs) could potentially improve the emission level of the power plants, and should be implemented to minimize emissions under current design characteristics. These BMPs include (1) more frequent tuning of turbine combustors; (2) onsite testing of natural gas characteristics in comparison to turbine manufacturer's specifics and tuning of turbine to natural gas quality; (3) onsite testing of aqueous ammonia to ensure adequate ammonia concentration in the mixed solution, and the purity of the solution; (4) more careful inspection of the heat recovery steam generator (HRSG), and the selective catalytic reduction (SCR) during operation and maintenance; (5) annual testing of the catalyst coupon on the SCR to ensure catalyst effectiveness; and (6) annual ammonia injection grid (AIG) tuning. The study found that without major modification to the plants, improving the management of the Beijing gas turbine power plants may potentially reduce the current hourly average NOx emission level of 5-10 parts per million (ppm; ranges reflects plant variation) by up to 20%. The exact improvement associated with each BMP for each facility requires more detailed analysis, and requires engagement of turbine, HRSG, and SCR manufacturers. This potential improvement is an important factor to consider when strengthening the emission standard. However, note that with the continuous needs of improving air quality within the area, more expensive control measures, such as retrofitting the turbines or the HRSGs, may be considered. This study analyzed the potential emission reductions associated with implementing the best management practices (BMPs) on the combined cycle and cogeneration power plants in Beijing. It determined that implementing the BMPs could potentially achieve up to 580 metric tonnes, or 0.6%, reductions of all NOx emissions in Beijing. Many other cities in China and Asia battling air quality issues may find the information useful in order to evaluate the emission reduction potential of their own gas turbine power plants.
Yin, Xianghui; Wang, Rui; Wang, Shaoxin; Wang, Yukun; Jin, Chengbin; Cao, Zhaoliang; Xuan, Li
2018-02-01
Atmospheric turbulence seriously affects the quality of free-space laser communication. The Strehl ratio (SR) is used to evaluate the effect of atmospheric turbulence on the receiving energy of free-space laser communication systems. However, the SR method does not consider the area of the laser-receiving end face. In this study, the power-in-the-bucket (PIB) method is demonstrated to accurately evaluate the effect of turbulence on the receiving energy. A theoretical equation is first obtained to calculate PIB. Simulated and experimental validations are then performed to verify the effectiveness of the theoretical equation. This work may provide effective guidance for the design and evaluation of free-space laser communication systems.
Wang, Hourong; Sun, Guiping; Zheng, Boyang; Yuan, Kai
2018-05-12
In order to reflect the research achievements of acupuncture on international academic community and study the acupuncture international discourse power from 2007 through 2017, we used text analysis software to analyze 5668 papers that focusing on acupuncture research in the recent 10 years. The results show that international acupuncture research trend has been formed, the research force diverges to the rest of the world with "China-America" as the center, and the study focuses on its sight and the interaction between China and foreign countries is good. Under the perspective of international discourse power, the construction of the national communication platform, the cultivation of academic centers and research fields, and the interaction with international research forces will enhance the quality of Chinese acupuncture research, and these will become an important task in enhancing the international discourse power of Chinese acupuncture.
Schoeb, Veronika; Bürge, Elisabeth
2012-06-01
Patient participation is nowadays considered important for high quality patient care. Although the literature on health care professions provides some insights into this topic, specific aspects in the field of physiotherapy are less known. The objective of this review was to investigate how patients and physiotherapists perceive patient participation, especially in regards to what it means for them and the role patients play during physiotherapy treatment sessions. We used a narrative synthesis of qualitative studies. We conducted a systematic search in six databases using a set of key words, extracted relevant data, performed quality assessment and synthesized findings from the selected studies. Out of 160 studies, 11 were retained. Two main themes emerged: the conceptualization of patient participation and the patients' role preferences. Patient participation included various activities including goal setting, information exchange, decision-making and exercise training and often influenced the power relation between patient and physiotherapist. Patients' willingness to participate varied, and they often did not play their desired role. Patients and physiotherapists perceived participation to be valuable yet challenging. Problems of conceptualization, power inequalities, lack of health professionals' skills and lack of the right attitude to share power and responsibility from both sides were some of the barriers that impeded optimal participation. Copyright © 2011 John Wiley & Sons, Ltd.
ERIC Educational Resources Information Center
Royuela, Vicente; Lopez-Tamayo, Jordi; Surinach, Jordi
2009-01-01
The European Union launched the Lisbon Strategy in 2000 with the aim of establishing itself as the world's most powerful economy. The importance of job quality has returned to the top of the European employment and social policy agenda. As targets are set, significant progress has been made in the creation of indicators. In this study, we compute…
NASA Astrophysics Data System (ADS)
Ded, A. V.; Maltsev, V. N.; Sikorski, S. P.
2018-04-01
Since July 2014 the interstate standard GOST 32144-2013 is the only document that defines standard requirements for the power quality in the territory of the Russian Federation. The new standard preamble specifies that this document considers the requirements of the European regional standard EN 50160-2010. However, GOST authors established the degree of standards conformity as nonequivalent. In connection with Russia's accession to the World Trade Organization (WTO) all requirements for goods including electric energy should correspond the international standard requirements. The article analyzes the above standard requirements and assesses the requirements for the power quality standards used in the European Union and in the Russian Federation.
Potential benefits of long-distance electricity transmission in China for air quality and climate
NASA Astrophysics Data System (ADS)
Peng, W.; Mauzerall, D. L.; Yuan, J.; Zhao, Y.; Lin, M.; Zhang, Q.
2015-12-01
China is expanding west-to-east long-distance electricity transmission capacity with the aim of reducing eastern coal power production and resulting air pollution. In addition to coal power, this new grid capacity can be used to transport renewable-generated electricity with resulting climate co-benefits. Here we use an integrated assessment to evaluate the air quality and climate benefits of twelve proposed transmission lines in China, and compare two energy-by-wire strategies that transmit 1) only coal power (Coal-by-wire, CbW) or 2) combined renewable plus coal power (Renewable and coal-by-wire, (RE+C)bW), with 3) the current practice of transporting coal by rail for conversion to electricity near eastern demand centers (Coal-by-rail, CbR). Based on a regional atmospheric chemistry model, WRF-Chem, electricity transmission through the proposed lines leads to 2-3 μg/m3 (2-7%) reduction in the annual mean concentrations of fine particulate matter (PM2.5) in the eastern provinces relative to 2010 levels, roughly ~1 μg/m3 greater than the reduction achieved in CbR where dirty coal units are locally replaced with efficient ones. Although the eastern air quality improvement is similar irrespective of the fuel source to power the lines, adding coal generation results in up to 3% increase in annual mean PM2.5 levels in some exporting provinces, whereas such increase is not observed when most added capacity is renewable-based. Counting both the economic value of reduced carbon emissions and the health-related air quality benefits can significantly improve the cost-effectiveness of transmitting both renewable and coal power. Comparing (RE+C)bW with the two coal-based options, we find not only 20% larger reduction in air-pollution-related deaths, but also three times greater reduction in CO2 emissions. Our study hence demonstrates the significance of coordinating renewable energy planning with transmission planning to simultaneously tackle air pollution and climate change in China and globally.
Quality factor concept in piezoceramic transformer performance description.
Mezheritsky, Alex V
2006-02-01
A new general approach based on the quality factor concept to piezoceramic transformer (PT) performance description is proposed. The system's quality factor, material elastic anisotropy, and coupling factors of the input and output sections of an electrically excited and electrically loaded PT fully characterize its resonance and near-resonance behavior. The PT efficiency, transformation ratio, and input and output power were analytically analyzed and simulated as functions of the load and frequency for the simplest classical Langevin-type and Rosen-type PT designs. A new formulation of the electrical input impedance allows one to separate the power consumed by PT from the power transferred into the load. The system's PT quality factor takes into account losses in each PT "input-output-load" functional components. The loading process is changing PT input electrical impedance on the way that under loading the minimum series impedance is increasing and the maximum parallel impedance is decreasing coincidentally. The quality-factors ratio, between the states of fully loaded and nonloaded PT, is one of the best measures of PTs dynamic performance--practically, the lower the ratio is, the better PT efficiency. A simple and effective method for the loaded PT quality factor determination is proposed. As was found, a piezoceramic with low piezoelectric anisotropy is required to provide maximum PT efficiency and higher corresponding voltage gain. Limitations on the PT output voltage and power, caused by nonlinear effects in piezoceramics, were established.
Protective Controller against Cascade Outages with Selective Harmonic Compensation Function
NASA Astrophysics Data System (ADS)
Abramovich, B. N.; Kuznetsov, P. A.; Sychev, Yu A.
2018-05-01
The paper presents data on the power quality and development of protective devices for the power networks with distributed generation (DG).The research has shown that power quality requirements for DG networks differ from conventional ones. That is why main tendencies, protective equipment and filters should be modified. There isa developed algorithm for detection and prevention of cascade outages that can lead to the blackoutin DG networks and there was a proposed structural scheme for a new active power filter for selective harmonics compensation. Analysis of these theories and equipment led to the development of protective device that could monitor power balance and cut off non-important consumers. The last part of the article describes a microcontroller prototype developed for connection to the existing power station control center.
NASA Astrophysics Data System (ADS)
Zhang, Lei; Zhao, Tianliang; Gong, Sunling; Kong, Shaofei; Tang, Lili; Liu, Duanyang; Wang, Yongwei; Jin, Lianji; Shan, Yunpeng; Tan, Chenghao; Zhang, Yingjie; Guo, Xiaomei
2018-02-01
Air pollutant emissions play a determinant role in deteriorating air quality. However, an uncertainty in emission inventories is still the key problem for modeling air pollution. In this study, an updated emission inventory of coal-fired power plants (UEIPP) based on online monitoring data in Jiangsu Province of East China for the year of 2012 was implemented in the widely used Multi-resolution Emission Inventory for China (MEIC). By employing the Weather Research and Forecasting model with Chemistry (WRF-Chem), two simulation experiments were executed to assess the atmospheric environment change by using the original MEIC emission inventory and the MEIC inventory with the UEIPP. A synthetic analysis shows that power plant emissions of PM2.5, PM10, SO2, and NOx were lower, and CO, black carbon (BC), organic carbon (OC) and NMVOCs (non-methane volatile organic compounds) were higher in UEIPP relative to those in MEIC, reflecting a large discrepancy in the power plant emissions over East China. In accordance with the changes in UEIPP, the modeled concentrations were reduced for SO2 and NO2, and increased for most areas of primary OC, BC, and CO. Interestingly, when the UEIPP was used, the atmospheric oxidizing capacity significantly reinforced. This was reflected by increased oxidizing agents, e.g., O3 and OH, thus directly strengthening the chemical production from SO2 and NOx to sulfate and nitrate, respectively, which offset the reduction of primary PM2.5 emissions especially on haze days. This study indicates the importance of updating air pollutant emission inventories in simulating the complex atmospheric environment changes with implications on air quality and environmental changes.
Anterior or posterior walkers for children with cerebral palsy? A systematic review.
Poole, Marilyn; Simkiss, Doug; Rose, Alice; Li, François-Xavier
2018-05-01
To review the literature comparing use of anterior and posterior walkers (PW's) by children with cerebral palsy (CP) to determine which walker type is preferable. Electronic databases were searched using pre-defined terms by two independent reviewers. Reference lists of included studies were hand searched. Studies published between 1985 and 2016 comparing use of anterior and PW's by children with CP were included. All study designs and outcomes were accepted. Risk of bias was assessed using the "Quality assessment standard for a cross-over study". Quality of evidence was evaluated using GRADE. Six studies were analysed. All studies had small sample sizes. A total of 4/6 studies were randomized. A total of 4/6 had high risk of bias. Outcomes included velocity, pelvic tilt, hip flexion, knee flexion, step length, stride length, cadence, double stance time, oxygen cost and participant/parental preference. Velocity, trunk flexion/pelvic tilt, and stability may be improved by using a PW, however, GRADE quality was very low for all outcomes and there was heterogeneity between studies. The majority of participants and parents preferred the PW. Heterogeneity and low quality of existing evidence prevented recommendation of one walker type. Well-designed studies with adequate power are needed to inform clinical recommendations. Implications for rehabilitation Clinical recommendations cannot be made for whether anterior or posterior walkers are preferable for children with cerebral palsy based on the existing evidence. Velocity, trunk flexion/pelvic tilt, and stability may be improved by using a posterior walker. The majority of walking aid users and their parents preferred posterior walkers. Adequately powered studies designed to minimize bias are needed.
Taking into Account the Quality of the Relationship in HIV Disclosure.
Smith, Charlotte; Cook, Rachel; Rohleder, Poul
2017-01-01
Despite growing interest in HIV disclosure, most theoretical frameworks and empirical studies focus on individual and social factors affecting the process, leaving the contribution of interpersonal factors relatively unexplored. HIV transmission and disclosure often occur within a couple however, and this is where disclosure has the most scope as a HIV transmission intervention. With this in mind, this study explores whether perceived relationship quality influences HIV disclosure outcomes. Ninety-five UK individuals with HIV participated in a cross-sectional survey. Retrospective data were collected on their perceived relationship quality prior to disclosing their HIV positive status, and on disclosure outcomes. Perceived relationship quality was found to significantly affect disclosure outcomes. Positive qualities in the relationship were associated with positive outcomes, whereas negative qualities were associated with negative outcomes. Results further confirmed that this association was not merely correlational, but demonstrated predictive power. Relationship quality might act as either a risk or a resilience factor in the disclosure process, and thus warrants greater attention in future research.
1982-01-01
aircraft powered by gas turbines through the year 2000. The study also predicted that some types of diesels and steam powerplants could potentially...figure 3. Diesels are more efficient even at high- power settings. CHANGES TO FUELS Interrelationships between the price and quality of fuel have...emaIcal Physics 20 (1979) pp. 6446- PP 252 899), AD) A061 938 Nunn, Wolter R.. -Poeltion Finding with Prior Kowledge of .Eonrience Parameters," 5 pp., Jun
1980-06-01
Grazing and the Livestock Industry. In: Brokaw, Howard P. Wildlife and America. Council on Environmental Quality, U.S. Fish and Wildlife Service...Environmental Impact Studies of the Navajo and Kaiparowits Power Plants. Second Annual Report. 1 June 1972 - 31 May 1973. National Technical Information Service... Navajo and Kaiparowits Power Plants. Fourth Annual Report. 1 June 1974 - 31 May 1975. National Technical Information Service, Springfield, VA 22161. L
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…
Federal Register 2010, 2011, 2012, 2013, 2014
2010-06-18
... Promulgation of Air Quality Implementation Plans; Maryland; Revision to Emission Limitations for R. Paul Smith... revision pertains to revised emission limitations for the R. Paul Smith Power Station located in Washington... R. Paul Smith Power Station in Washington County. This facility had annual nitrogen oxides (NOx...
Code of Federal Regulations, 2011 CFR
2011-04-01
... 18 Conservation of Power and Water Resources 2 2011-04-01 2011-04-01 false Basin regulations-Water Code and Administrative Manual-Part III Water Quality Regulations. 410.1 Section 410.1 Conservation of Power and Water Resources DELAWARE RIVER BASIN COMMISSION ADMINISTRATIVE MANUAL BASIN REGULATIONS; WATER...
Water-Chemistry and Its Utility Systems in CCP Power Units (Review)
NASA Astrophysics Data System (ADS)
Larin, B. M.
2018-01-01
Damageability of heat transfer surfaces of waste heat recovery steam generators (HRSG) of combined- cycle plants (CCP) can be reduced due to an increase in the quality of make-up and feed water, the use of phosphate-alkaline or amino compound water chemistry (WC), and improved chemical quality control of the heat carrier and make-up water preparation techniques. Temporary quality standards for the heat medium developed by the All-Russia Thermal Engineering institute (VTI) for CCP power units are presented in comparison with the IAPWS standards; preferences for the choice of a WC type for some power units commissioned in Russia in the first decade of this century are shown; and operational data on the quality of feed, boiler water, and steam for two large CCP-450 and CCP-425 power units are given. The state and prospects for the development of chemical-technological monitoring systems and CCP water treatment plants are noted. Estimability of some CCP diagnostic parameters by measuring specific electric conductivity and pH is shown. An extensive bibliography on this topic is given.
High-power picosecond laser with 400W average power for large scale applications
NASA Astrophysics Data System (ADS)
Du, Keming; Brüning, Stephan; Gillner, Arnold
2012-03-01
Laser processing is generally known for low thermal influence, precise energy processing and the possibility to ablate every type of material independent on hardness and vaporisation temperature. The use of ultra-short pulsed lasers offers new possibilities in the manufacturing of high end products with extra high processing qualities. For achieving a sufficient and economical processing speed, high average power is needed. To scale the power for industrial uses the picosecond laser system has been developed, which consists of a seeder, a preamplifier and an end amplifier. With the oscillator/amplifier system more than 400W average power and maximum pulse energy 1mJ was obtained. For study of high speed processing of large embossing metal roller two different ps laser systems have been integrated into a cylinder engraving machine. One of the ps lasers has an average power of 80W while the other has 300W. With this high power ps laser fluencies of up to 30 J/cm2 at pulse repetition rates in the multi MHz range have been achieved. Different materials (Cu, Ni, Al, steel) have been explored for parameters like ablation rate per pulse, ablation geometry, surface roughness, influence of pulse overlap and number of loops. An enhanced ablation quality and an effective ablation rate of 4mm3/min have been achieved by using different scanning systems and an optimized processing strategy. The max. achieved volume rate is 20mm3/min.
Power Spectrum of a Noisy System Close to a Heteroclinic Orbit
NASA Astrophysics Data System (ADS)
Giner-Baldó, Jordi; Thomas, Peter J.; Lindner, Benjamin
2017-07-01
We consider a two-dimensional dynamical system that possesses a heteroclinic orbit connecting four saddle points. This system is not able to show self-sustained oscillations on its own. If endowed with white Gaussian noise it displays stochastic oscillations, the frequency and quality factor of which are controlled by the noise intensity. This stochastic oscillation of a nonlinear system with noise is conveniently characterized by the power spectrum of suitable observables. In this paper we explore different analytical and semianalytical ways to compute such power spectra. Besides a number of explicit expressions for the power spectrum, we find scaling relations for the frequency, spectral width, and quality factor of the stochastic heteroclinic oscillator in the limit of weak noise. In particular, the quality factor shows a slow logarithmic increase with decreasing noise of the form Q˜ [ln (1/D)]^2. Our results are compared to numerical simulations of the respective Langevin equations.
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.
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.
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
Morgan, Philip J; Collins, Clare E; Plotnikoff, Ronald C; Cook, Alyce T; Berthon, Bronwyn; Mitchell, Simon; Callister, Robin
2012-02-01
The aim of this study was to evaluate the impact of a workplace-based weight loss program (Workplace POWER [Preventing Obesity Without Eating like a Rabbit]) for male shift workers on a number of work-related outcomes. A total of 110 overweight/obese (body mass index = 25-40) (mean [SD] age = 44.3 [8.6] years; body mass index = 30.5 [3.6]) male employees at Tomago Aluminium (New South Wales, Australia) were randomized to either (i) Workplace POWER program (n = 65) or (ii) a 14-week wait-list control group (n = 45). Men were assessed at baseline and 14-week follow-up for weight, quality of life, sleepiness, productivity at work (presenteeism), absenteeism, and workplace injuries. Retention was 81%. Intention-to-treat analysis using linear mixed models revealed a significant intervention effect for weight, quality of life (mental), presenteeism, absenteeism, and injuries. The Workplace POWER weight loss program improved a number of important work-related outcomes in male shift workers.
Improved power and efficiency for tapered lasers with optimized photonic crystal structures
NASA Astrophysics Data System (ADS)
Ma, Xiaolong; Qu, Hongwei; Zhao, Shaoyu; Zhou, Xuyan; Lin, Yuzhe; Zheng, Wanhua
2017-10-01
High power and high beam quality laser sources are required in numerous applications such as nonlinear frequency conversion, optical pumping of solid-state and fiber lasers, material processing and others. Tapered lasers can provide a high output power while keeping a high beam quality. However, the conventional tapered lasers suffer from a large vertical beam divergence. We have demonstrated 2-mm long tapered lasers with photonic crystal structures. A high beam quality and a narrow vertical divergence are achieved. In this paper, we optimized the photonic crystal structure and fabricated a 4-mm long tapered laser to further increase the output power and the wall-plug efficiency. Compared with our precious wafer, the optimized structure has a lower doping level to reduce the internal loss. The period of the photonic crystal structure and the thickness of the upper cladding are also reduced. The device has a 1-mm long ridge-waveguide section and a 3-mm long tapered section. The taper angle is 4°. An output power of 7.3 W is achieved with a peak wall-plug efficiency of 46% in continuous-wave mode. The threshold current is around 500 mA and the slope efficiency is 0.93 W/A. In pulsed mode, the output power is 15.6 W and the maximum wall-plug efficiency is 48.1%. The far-field divergence with full width at half maximum is 6.3° for the lateral direction at 3 A. The vertical far-field beam divergence is around 11° at different injection levels. High beam qualities are demonstrated by beam quality factor M2 of 1.52 for the lateral direction and 1.54 for the vertical direction.
Impact of applied ultrasonic power on the low temperature drying of apple.
Santacatalina, J V; Contreras, M; Simal, S; Cárcel, J A; Garcia-Perez, J V
2016-01-01
Low temperature drying (LTD) allows high-quality dried products to be obtained, preserving the nutritional properties of fresh foods better than conventional drying, but it is a time-consuming operation. Power ultrasound (US) could be used to intensify LTD, but it should be taken into account that process variables, such as the level of applied power, have an influence on the magnitude and extension of the ultrasonic effects. Therefore, the aim of this work was to assess the influence of the level of applied ultrasonic power on the LTD of apple, analyzing the drying kinetics and the quality of the dried product. For that purpose, apple (Malus domestica cv. Granny Smith) cubes (8.8mm side) were dried (2m/s) at two different temperatures (10 and -10°C), without and with (25, 50 and 75 W) US application. In the dried apple, the rehydration kinetics, hardness, total phenolic content, antioxidant capacity and microstructure were analyzed to evaluate the impact of the level of applied ultrasonic power. At both temperatures, 10 and -10°C, the higher the ultrasonic power level, the shorter the drying time; the maximum shortening of the drying time achieved was 80.3% (at -10°C and 75 W). The ultrasonic power level did not significantly (p<0.05) affect the quality parameters analyzed. Therefore, US could be considered a non-thermal method of intensifying the LTD of fruits, like apple, with only a mild impact on the quality of the dried product. Copyright © 2015 Elsevier B.V. All rights reserved.
Air pollution effects due to deregulation of the electric industry
NASA Astrophysics Data System (ADS)
Davoodi, Khojasteh Riaz
The Energy Policy Act of 1992 introduced the concept of open-access into the electric utility industry which allows privately-owned utilities to transmit power produced by non-utility generators and independent power producers (IPPs). In April 1996, the Federal Energy Regulatory Commission (FERC) laid down the final rules (Orders No. 888 & No. 889), which required utilities to open their transmission lines to any power producer and charge them no more than what they pay for the use of their own lines. These rules set the stage for the retail sale of electricity to industrial, commercial and residential utility customers; non-utility generators (Nugs); and power marketers. These statutory, regulatory and administrative changes create for the electric utility industry two different forces that contradict each other. The first is the concept of competition among utility companies; this places a greater emphasis on electric power generation cost control and affects generation/fuel mix selection and demand side management (DSM) activities. The second force, which is converse to the first, is that utilities are major contributors to the air pollution burden in the United States and environmental concerns are forcing them to reduce emissions of air pollutants by using more environmentally friendly fuels and implementing energy saving programs. This study evaluates the impact of deregulation within the investor owned electric utilities and how this deregulation effects air quality by investigating the trend in demand side management programs and generation/fuel mix. A survey was conducted of investor owned utilities and independent power producers. The results of the survey were analyzed by analysis of variance and regression analysis to determine the impact to Air Pollution. An air Quality Impact model was also developed in this study. This model consists of six modules: (1) demand side management and (2) consumption of coal, (3) gas, (4) renewable, (5) oil and (6) nuclear sources until the year 2005. Each module was analyzed separately and the result from each module was transferred into the Air Quality Impact model. The model assesses the changes in electricity generation within each module due to deregulation and these changes can then be correlated to the emission of air pollutants in the United States.
Schlimp, C J; Breiteneder, M; Lederer, W
2004-05-01
Automated external defibrillators (AEDs) must combine easy operability and high-quality diagnosis even under unfavorable conditions. This study determined the influence of electromagnetic interference caused by high-voltage power lines with 16.7-Hz alternating current on the quality of AEDs' rhythm analysis. Two AEDs frequently used in Austria were tested near high-voltage power lines (15 kV or 110 kV, alternating current with 16.7 Hz). The defibrillation electrodes were attached either to a proband with true sinus rhythm or to a resuscitation dummy with generated sinus rhythm, ventricular fibrillation, ventricular tachycardia or asystole. Electromagnetic interference was much more prominent in a human's than in a dummy's electrocardiogram and depended on the position of the electrodes and cables in relation to the power line. Near high-voltage power lines the AEDs showed a significant operational fault. One AED interpreted the interference as a motion artifact, even when underlying rhythms were clearly detectable. The other AED interpreted 16.7-Hz oscillation as ventricular fibrillation with consequent shock advice when no underlying rhythm was detected. The tested AEDs neither filter nor recognize a technical interference of 16.7 Hz caused by 15-kV power lines above railway tracks or 110-kV overland power lines, as run by railway companies in Austria, Germany, Norway, Sweden and Switzerland. These failures in AEDs' algorithms for rhythm analysis may cause substantial harm to patients undergoing public access defibrillation. The proper function of AEDs needs to be reconsidered to guarantee patients' safety near high-voltage power lines.
Advance Care Planning and the Quality of End-of-Life Care among Older Adults
Bischoff, Kara E.; Sudore, Rebecca; Miao, Yinghui; Boscardin, W. John; Smith, Alexander K.
2013-01-01
Background Advance care planning is increasingly common, but whether it influences end-of-life quality of care remains controversial. Design Medicare data and survey data from the Health and Retirement Study were combined to determine whether advance care planning was associated with quality metrics. Setting The nationally representative Health and Retirement Study. Participants 4394 decedent subjects (mean age 82.6 years at death, 55% women). Measurements Advance care planning was defined as having an advance directive, durable power of attorney or having discussed preferences for end-of-life care with a next-of-kin. Outcomes included previously reported quality metrics observed during the last month of life (rates of hospital admission, in-hospital death, >14 days in the hospital, intensive care unit admission, >1 emergency department visit, hospice admission, and length of hospice ≤3 days). Results Seventy-six percent of subjects engaged in advance care planning. Ninety-two percent of advance directives stated a preference to prioritize comfort. After adjustment, subjects who engaged in advance care planning were less likely to die in a hospital (adjusted RR 0.87, 95% CI 0.80-0.94), more likely to be enrolled in hospice (aRR 1.68, 1.43-1.97), and less likely to receive hospice for ≤3 days before death (aRR 0.88, 0.85-0.91). Having an advance directive, a durable-power-of-attorney or an advance care planning discussion were each independently associated with a significant increase in hospice use (p<0.01 for all). Conclusion Advance care planning was associated with improved quality of care at the end of life, including less in-hospital death and increased use of hospice. Having an advance directive, assigning a durable power of attorney and conducting advance care planning discussions are all important elements of advance care planning. PMID:23350921
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.
IDMA-Based MAC Protocol for Satellite Networks with Consideration on Channel Quality
2014-01-01
In order to overcome the shortcomings of existing medium access control (MAC) protocols based on TDMA or CDMA in satellite networks, interleave division multiple access (IDMA) technique is introduced into satellite communication networks. Therefore, a novel wide-band IDMA MAC protocol based on channel quality is proposed in this paper, consisting of a dynamic power allocation algorithm, a rate adaptation algorithm, and a call admission control (CAC) scheme. Firstly, the power allocation algorithm combining the technique of IDMA SINR-evolution and channel quality prediction is developed to guarantee high power efficiency even in terrible channel conditions. Secondly, the effective rate adaptation algorithm, based on accurate channel information per timeslot and by the means of rate degradation, can be realized. What is more, based on channel quality prediction, the CAC scheme, combining the new power allocation algorithm, rate scheduling, and buffering strategies together, is proposed for the emerging IDMA systems, which can support a variety of traffic types, and offering quality of service (QoS) requirements corresponding to different priority levels. Simulation results show that the new wide-band IDMA MAC protocol can make accurate estimation of available resource considering the effect of multiuser detection (MUD) and QoS requirements of multimedia traffic, leading to low outage probability as well as high overall system throughput. PMID:25126592
Methods for slow axis beam quality improvement of high power broad area diode lasers
NASA Astrophysics Data System (ADS)
An, Haiyan; Xiong, Yihan; Jiang, Ching-Long J.; Schmidt, Berthold; Treusch, Georg
2014-03-01
For high brightness direct diode laser systems, it is of fundamental importance to improve the slow axis beam quality of the incorporated laser diodes regardless what beam combining technology is applied. To further advance our products in terms of increased brightness at a high power level, we must optimize the slow axis beam quality despite the far field blooming at high current levels. The later is caused predominantly by the built-in index step in combination with the thermal lens effect. Most of the methods for beam quality improvements reported in publications sacrifice the device efficiency and reliable output power. In order to improve the beam quality as well as maintain the efficiency and reliable output power, we investigated methods of influencing local heat generation to reduce the thermal gradient across the slow axis direction, optimizing the built-in index step and discriminating high order modes. Based on our findings, we have combined different methods in our new device design. Subsequently, the beam parameter product (BPP) of a 10% fill factor bar has improved by approximately 30% at 7 W/emitter without efficiency penalty. This technology has enabled fiber coupled high brightness multi-kilowatt direct diode laser systems. In this paper, we will elaborate on the methods used as well as the results achieved.
An evaluation of helicopter noise and vibration ride qualities criteria
NASA Technical Reports Server (NTRS)
Hammond, C. E.; Hollenbaugh, D. D.; Clevenson, S. A.; Leatherwood, J. D.
1981-01-01
Two methods of quantifying helicopter ride quality; absorbed power for vibration only and the NASA ride comfort model for both noise and vibration are discussed. Noise and vibration measurements were obtained on five operational US Army helicopters. The data were converted to both absorbed power and DISC's (discomfort units used in the NASA model) for specific helicopter flight conditions. Both models indicate considerable variation in ride quality between the five helicopters and between flight conditions within each helicopter.
Quality Assurance Framework for Mini-Grids
DOE Office of Scientific and Technical Information (OSTI.GOV)
Esterly, Sean; Baring-Gould, Ian; Booth, Samuel
To address the root challenges of providing quality power to remote consumers through financially viable mini-grids, the Global Lighting and Energy Access Partnership (Global LEAP) initiative of the Clean Energy Ministerial and the U.S. Department of Energy teamed with the National Renewable Energy Laboratory (NREL) and Power Africa to develop a Quality Assurance Framework (QAF) for isolated mini-grids. The framework addresses both alternating current (AC) and direct current (DC) mini-grids, and is applicable to renewable, fossil-fuel, and hybrid systems.
Power in Practice: Moments of Reflection.
Karnick, Paula M
2016-07-01
Power in practice reveals itself in many ways. There are many definitions of power but in nursing care it could be said that the power is within the patient. Nurses facilitate patients power by engaging them in dialogical engagements. This helps patients to decide how to utilize the power of living their quality. © The Author(s) 2016.
Li, Shenshen; Wu, Yangfeng; Du, Xin; Li, Xian; Patel, Anushka; Peterson, Eric D; Turnbull, Fiona; Lo, Serigne; Billot, Laurent; Laba, Tracey; Gao, Runlin
2015-03-01
Acute coronary syndromes (ACSs) are a major cause of morbidity and mortality, yet effective ACS treatments are frequently underused in clinical practice. Randomized trials including the CPACS-2 study suggest that quality improvement initiatives can increase the use of effective treatments, but whether such programs can impact hard clinical outcomes has never been demonstrated in a well-powered randomized controlled trial. The CPACS-3 study is a stepped-wedge cluster-randomized trial conducted in 104 remote level 2 hospitals without PCI facilities in China. All hospitalized ACS patients will be recruited consecutively over a 30-month period to an anticipated total study population of more than 25,000 patients. After a 6-month baseline period, hospitals will be randomized to 1 of 4 groups, and a 6-component quality improvement intervention will be implemented sequentially in each group every 6months. These components include the following: establishment of a quality improvement team, implementation of a clinical pathway, training of physicians and nurses, hospital performance audit and feedback, online technical support, and patient education. All patients will be followed up for 6months postdischarge. The primary outcome will be the incidence of in-hospital major adverse cardiovascular events comprising all-cause mortality, myocardial infarction or reinfarction, and nonfatal stroke. The CPACS-3 study will be the first large randomized trial with sufficient power to assess the effects of a multifaceted quality of care improvement initiative on hard clinical outcomes, in patients with ACS. Copyright © 2014 Elsevier Inc. All rights reserved.
Kilohertz Pulse Repetition Frequency Slab Ti:sapphire Lasers with High Average Power (10 W)
NASA Astrophysics Data System (ADS)
Wadsworth, William J.; Coutts, David W.; Webb, Colin E.
1999-11-01
High-average-power broadband 780-nm slab Ti:sapphire lasers, pumped by a kilohertz pulse repetition frequency copper vapor laser (CVL), were demonstrated. These lasers are designed for damage-free power scaling when pumped by CVL s configured for maximum output power (of order 100 W) but with poor beam quality ( M 2 300 ). A simple Brewster-angled slab laser side pumped by a CVL produced 10-W average power (1.25-mJ pulses at 8 kHz) with 4.2-ns FWHM pulse duration at an absolute efficiency of 15% (68-W pump power). Thermal lensing in the Brewster slab laser resulted in multitransverse mode output, and pump absorption was limited to 72% by the maximum doping level for commercially available Ti:sapphire (0.25%). A slab laser with a multiply folded zigzag path was therefore designed and implemented that produced high-beam-quality (TEM 00 -mode) output when operated with cryogenic cooling and provided a longer absorption path for the pump. Excessive scattering of the Ti:sapphire beam at the crystal surfaces limited the efficiency of operation for the zigzag laser, but fluorescence diagnostic techniques, gain measurement, and modeling suggest that efficient power extraction ( 15 W TEM 00 , 23% efficiency) from this laser would be possible for crystals with an optical quality surface polish.
Renewable Energy Zones for the Africa Clean Energy Corridor
DOE Office of Scientific and Technical Information (OSTI.GOV)
Wu, Grace C.; Deshmukh, Ranjit; Ndhlukula, Kudakwashe
Multi-criteria Analysis for Planning Renewable Energy (MapRE) is a study approach developed by the Lawrence Berkeley National Laboratory with the support of the International Renewable Energy Agency (IRENA). The approach combines geospatial, statistical, energy engineering, and economic methods to comprehensively identify and value high-quality wind, solar PV, and solar CSP resources for grid integration based on techno-economic criteria, generation profiles (for wind), and socio-environmental impacts. The Renewable Energy Zones for the Africa Clean Energy Corridor study sought to identify and comprehensively value high-quality wind, solar photovoltaic (PV), and concentrating solar power (CSP) resources in 21 countries in the East andmore » Southern Africa Power Pools to support the prioritization of areas for development through a multi-criteria planning process. These countries include Angola, Botswana, Burundi, Djibouti, Democratic Republic of Congo, Egypt, Ethiopia, Kenya, Lesotho, Libya, Malawi, Mozambique, Namibia, Rwanda, South Africa, Sudan, Swaziland, Tanzania, Uganda, Zambia, and Zimbabwe. The study includes the methodology and the key results including renewable energy potential for each region.« less
Dynamic power scheduling system for JPEG2000 delivery over wireless networks
NASA Astrophysics Data System (ADS)
Martina, Maurizio; Vacca, Fabrizio
2003-06-01
Third generation mobile terminals diffusion is encouraging the development of new multimedia based applications. The reliable transmission of audiovisual content will gain major interest being one of the most valuable services. Nevertheless, mobile scenario is severely power constrained: high compression ratios and refined energy management strategies are highly advisable. JPEG2000 as the source encoding stage assures excellent performance with extremely good visual quality. However the limited power budged imposes to limit the computational effort in order to save as much power as possible. Starting from an error prone environment, as the wireless one, high error-resilience features need to be employed. This paper tries to investigate the trade-off between quality and power in such a challenging environment.
Beam control of high-power broad-area photonic crystal lasers using ladderlike groove structure
NASA Astrophysics Data System (ADS)
Wang, Tao; Wang, Lijie; Shu, Shili; Tian, Sicong; Lu, Zefeng; Hou, Guanyu; Lu, Huanyu; Tong, Cunzhu; Wang, Lijun
2017-06-01
The high-power broad-area (BA) photonic bandgap crystal (PBC) diode laser is promising as a high-brightness laser source, however, it suffers from poor lateral beam quality owing to the intrinsic drawback of BA lasers. In this paper, a ladderlike groove structure (LLGS) was proposed to improve both the lateral beam quality and emission power of BA PBC lasers. An approximately 15.4% improvement in output power and 25.2% decrease in the lateral beam parameter product (BPP) were realized and the underlying mechanism was discussed. On the basis of the one-dimensional PBC epitaxial structure, a stable vertical far field was demonstrated.
Quality pain management outcomes: the power of place.
Wild, L R; Mitchell, P H
2000-01-01
This study explores how an organization, as the context of care, influences nursing practice and a nursing-sensitive, quality health outcome-pain management. The results provide important insights into organizational patterns associated with favorable pain management-related outcomes as well as the congruence between and among subunits within the organization. Outcomes were most favorable on units where nurses had attitudes supportive of aggressive pain management and higher levels of coordination and discretion.
Simulation techniques in hyperthermia treatment planning
Paulides, MM; Stauffer, PR; Neufeld, E; Maccarini, P; Kyriakou, A; Canters, RAM; Diederich, C; Bakker, JF; Van Rhoon, GC
2013-01-01
Clinical trials have shown that hyperthermia (HT), i.e. an increase of tissue temperature to 39-44°C, significantly enhance radiotherapy and chemotherapy effectiveness (1). Driven by the developments in computational techniques and computing power, personalized hyperthermia treatment planning (HTP) has matured and has become a powerful tool for optimizing treatment quality. Electromagnetic, ultrasound, and thermal simulations using realistic clinical setups are now being performed to achieve patient-specific treatment optimization. In addition, extensive studies aimed to properly implement novel HT tools and techniques, and to assess the quality of HT, are becoming more common. In this paper, we review the simulation tools and techniques developed for clinical hyperthermia, and evaluate their current status on the path from “model” to “clinic”. In addition, we illustrate the major techniques employed for validation and optimization. HTP has become an essential tool for improvement, control, and assessment of HT treatment quality. As such, it plays a pivotal role in the quest to establish HT as an efficacious addition to multi-modality treatment of cancer. PMID:23672453
Paniagua-Martínez, I; Mulet, A; García-Alvarado, M A; Benedito, J
2018-01-01
Supercritical carbon dioxide inactivation technology represents a promising nonthermal processing method, as it causes minimum impact on the nutritional food properties. The aim of this study was to analyze the combined effect of supercritical carbon dioxide and high-power ultrasound on the inactivation of natural microbiota and the quality attributes of pineapple juice treated in a continuous flow system. Different juice residence times (3.06-4.6 min), at 100 bar and 31.5 ℃, were used. The results indicated that the microbiota inactivation was complete and the differences obtained in the quality attributes (2.2% for pH, 4.8% for °Brix, 2% for vitamin C) were minimal. During storage, microorganisms were not able to recover and the vitamin C decrease could be limited to 8.2% after four weeks. The results demonstrated that the supercritical carbon dioxide-high-power ultrasound technique could be an excellent alternative for the cold pasteurization of pineapple juice.
Chirped-pulse coherent-OTDR with predistortion
NASA Astrophysics Data System (ADS)
Xiong, Ji; Jiang, Jialin; Wu, Yue; Chen, Yongxiang; Xie, Lianlian; Fu, Yun; Wang, Zinan
2018-03-01
In this paper, a novel method for generating high-quality chirped pulses with IQ modulator is studied theoretically and experimentally, which is a crucial building block for high-performance coherent optical time-domain reflectometry (COTDR). In order to compensate the nonlinearity of the modulator transfer function, we present a predistortion technique for chirped-pulse coherent optical time-domain reflectometry (CP-COTDR), the arcsin predistortion method and the single sideband with a suppressed carrier analog modulation used to generate the high quality chirped optical pulse. The high order sidebands, due to the large amplitude of the modulation signal and the nonlinear transfer function of the IQ modulator, can be relieved by the predistortion process, which means the power and the quality of the generated chirped pulse has been improved. In the experiment, this method increases the peak power of the chirped pulse by 4.2 dB compared to the case without predistortion process, as for the CP-COTDR system, this method increases the signal-to-noise ratio of the demodulated phase variation by 6.3 dB.
Drug policy and administration affecting quality of life of the poor in Thailand.
Prutipinyo, Chardsumon; Sirichotiratana, Nithat
2011-09-01
This study aims to analyze drug policy and administration affecting quality of life of the poor in Thailand. Review of official reports and related documents, for the past 10 years (from 2000-2010). By imposing compulsory licensing, the Thai government maintains negotiating power over the price of pharmaceutical products with the patent holders of the original drugs. This gives an opportunity for relevant government agencies to produce or import patented drugs. At present, there are many problems and obstacles. The findings show that developing countries need to strengthen their negotiating power so that the pharmaceutical manufacturers cannot take advantage through mechanisms provided for such as compulsory licensing and provisions for flexibility in Trade-Related Intellectual Property Rights (TRIPS) agreement. Furthermore, these countries must support and empower the local pharmaceutical manufacturers to produce generic drugs. Developing countries should ensure that their populations have confidence in universal coverage service and medical systems regarding the quality of generic drugs.
Malik, Marek; Hnatkova, Katerina; Batchvarov, Velislav; Gang, Yi; Smetana, Peter; Camm, A John
2004-12-01
Regulatory authorities require new drugs to be investigated using a so-called "thorough QT/QTc study" to identify compounds with a potential of influencing cardiac repolarization in man. Presently drafted regulatory consensus requires these studies to be powered for the statistical detection of QTc interval changes as small as 5 ms. Since this translates into a noticeable drug development burden, strategies need to be identified allowing the size and thus the cost of thorough QT/QTc studies to be minimized. This study investigated the influence of QT and RR interval data quality and the precision of heart rate correction on the sample sizes of thorough QT/QTc studies. In 57 healthy subjects (26 women, age range 19-42 years), a total of 4,195 drug-free digital electrocardiograms (ECG) were obtained (65-84 ECGs per subject). All ECG parameters were measured manually using the most accurate approach with reconciliation of measurement differences between different cardiologists and aligning the measurements of corresponding ECG patterns. From the data derived in this measurement process, seven different levels of QT/RR data quality were obtained, ranging from the simplest approach of measuring 3 beats in one ECG lead to the most exact approach. Each of these QT/RR data-sets was processed with eight different heart rate corrections ranging from Bazett and Fridericia corrections to the individual QT/RR regression modelling with optimization of QT/RR curvature. For each combination of data quality and heart rate correction, standard deviation of individual mean QTc values and mean of individual standard deviations of QTc values were calculated and used to derive the size of thorough QT/QTc studies with an 80% power to detect 5 ms QTc changes at the significance level of 0.05. Irrespective of data quality and heart rate corrections, the necessary sample sizes of studies based on between-subject comparisons (e.g., parallel studies) are very substantial requiring >140 subjects per group. However, the required study size may be substantially reduced in investigations based on within-subject comparisons (e.g., crossover studies or studies of several parallel groups each crossing over an active treatment with placebo). While simple measurement approaches with ad-hoc heart rate correction still lead to requirements of >150 subjects, the combination of best data quality with most accurate individualized heart rate correction decreases the variability of QTc measurements in each individual very substantially. In the data of this study, the average of standard deviations of QTc values calculated separately in each individual was only 5.2 ms. Such a variability in QTc data translates to only 18 subjects per study group (e.g., the size of a complete one-group crossover study) to detect 5 ms QTc change with an 80% power. Cost calculations show that by involving the most stringent ECG handling and measurement, the cost of a thorough QT/QTc study may be reduced to approximately 25%-30% of the cost imposed by the simple ECG reading (e.g., three complexes in one lead only).
Using questionnaires to assess the quality of life and multidimensionality of fibromyalgia patients.
Martins, Marielza Regina Ismael; Polvero, Letícia Oliveira; Rocha, Carlos Eduardo; Foss, Marcos Henrique; Santos Junior, Randolfo Dos
2012-01-01
Fibromyalgia syndrome (FMS) is a painful condition of unknown etiology, highly prevalent, and associated with other conditions, which causes great impact on daily life and quality of life. To assess, due to the multifactorial character of the FMS, the discriminating power of instruments used to identify good indicators of self-assessment and self-knowledge. This is a descriptive, exploratory, comparative, cross-sectional study with quantitative approach, and sample comprising a treatment group (T), diagnosed with FMS (n = 63) and a control group (C), undergoing interconsultation at the Pain Outpatient Clinic (n = 75). The following instruments were used: Fibromyalgia Impact Questionnaire (FIQ); visual analogue scale (VAS); McGill Pain Questionnaire; and the Post-Sleep Inventory (PSI). To evaluate the quality of life, Medical Outcomes Study 12-item Short-Form Health Survey (SF-12) was used. In the two groups, female gender predominated. The mean age of the sample was 42.3 ± 4.3 years, 45% were married, and the average schooling was 8 ± 3.5 years. The mean duration of pain was 3.2 years, and a mean time of two years were required for the clinical diagnosis of FMS in group T. Group T had higher levels of pain, anxiety, and depression, worse quality of sleep, less flexibility, and worse quality of life, although some of these symptoms were also present in group C. All instruments had good discriminating power (P < 0.05), especially FIQ, VAS and PSI, whose areas under the ROC curve were greater.
Basak, Ramsankar; Bentley, John P; McCaffrey, David J; Bouldin, Alicia S; Banahan, Benjamin F
2015-05-01
Little is known about factors that affect pharmacists' roles in off-label prescribing. This study examined the effect of perceived impact on relationship quality (IRQ) on hospital pharmacists' willingness to influence a physician's decision regarding an indication-based off-label medication order (WTIP) (i.e., beyond FDA-approved indications) and the moderating roles of the appropriateness of the medication order and the relative expert power of the pharmacist. Pharmacists practicing in U.S. hospitals, recruited from membership rolls of state affiliates of the American Society of Health-System Pharmacists, were sent an electronic link to a questionnaire via their respective affiliates. A cross-sectional, randomized, 2 × 2 experimental design was used; participants were assigned to one of the indication-based off-label medication order scenarios. Relative expert power (i.e., power differential between the pharmacist and the physician) and appropriateness of the prescription were manipulated. Perceived IRQ was measured with multiple items. Pharmacists' WTIP in the scenario was the outcome variable. A total of 243 responses were included in multiple linear regression analyses. After controlling for dependence power, information power, communication effectiveness, perceived responsibility, and attitude, pharmacists' WTIP was negatively affected by perceived IRQ (estimate = -0.309, P < 0.05). This effect was more pronounced in groups exposed to the scenario where the pharmacist had lower relative expert power (estimate = -0.438, P < 0.05) and where the medication was less appropriate (estimate = -0.503, P < 0.05). Although willing to ensure rationality of off-label prescribing, pharmacists' WTIP was affected by a complex array of factors - the perceived impact of influence attempts on relationship quality between the pharmacist and the prescriber, the pharmacist's relative expert power, and the appropriateness of the off-label prescription. Increasing pharmacists' expert power and collaboration with physicians and promoting pharmacists' multifaceted contribution, collaborative or independent, to patient care may facilitate pharmacist services in off-label pharmaceutical care. Published by Elsevier Ltd.
78 FR 7816 - Quality Assurance Program Requirements (Operations)
Federal Register 2010, 2011, 2012, 2013, 2014
2013-02-04
... NUCLEAR REGULATORY COMMISSION [NRC-2013-0021] Quality Assurance Program Requirements (Operations...), DG-1300, ``Quality Assurance Program Requirements (Operations).'' DATES: Submit comments by April 1... CFR Part 50, Appendix B, ``Quality Assurance Criteria for Nuclear power Plants and Fuel Reprocessing...
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…
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.
970-nm ridge waveguide diode laser bars for high power DWBC systems
NASA Astrophysics Data System (ADS)
Wilkens, Martin; Erbert, Götz; Wenzel, Hans; Knigge, Andrea; Crump, Paul; Maaßdorf, Andre; Fricke, Jörg; Ressel, Peter; Strohmaier, Stephan; Schmidt, Berthold; Tränkle, Günther
2018-02-01
de lasers are key components in material processing laser systems. While mostly used as pump sources for solid state or fiber lasers, direct diode laser systems using dense wavelength multiplexing have come on the market in recent years. These systems are realized with broad area lasers typically, resulting in beam quality inferior to disk or fiber lasers. We will present recent results of highly efficient ridge waveguide (RW) lasers, developed for dense-wavelength-beamcombining (DWBC) laser systems expecting beam qualities comparable to solid state laser systems and higher power conversion efficiencies (PCE). The newly developed RW lasers are based on vertical structures with an extreme double asymmetric large optical cavity. Besides a low vertical divergence these structures are suitable for RW-lasers with (10 μm) broad ridges, emitting in a single mode with a good beam quality. The large stripe width enables a lateral divergence below 10° (95 % power content) and a high PCE by a comparably low series resistance. We present results of single emitters and small test arrays under different external feedback conditions. Single emitters can be tuned from 950 nm to 975 nm and reach 1 W optical power with more than 55 % PCE and a beam quality of M2 < 2 over the full wavelength range. The spectral width is below 30 pm FWHM. 5 emitter arrays were stabilized using the same setup. Up to now we reached 3 W optical power, limited by power supply, with 5 narrow spectral lines.
Kerl, Paul Y; Zhang, Wenxian; Moreno-Cruz, Juan B; Nenes, Athanasios; Realff, Matthew J; Russell, Armistead G; Sokol, Joel; Thomas, Valerie M
2015-09-01
Integrating accurate air quality modeling with decision making is hampered by complex atmospheric physics and chemistry and its coupling with atmospheric transport. Existing approaches to model the physics and chemistry accurately lead to significant computational burdens in computing the response of atmospheric concentrations to changes in emissions profiles. By integrating a reduced form of a fully coupled atmospheric model within a unit commitment optimization model, we allow, for the first time to our knowledge, a fully dynamical approach toward electricity planning that accurately and rapidly minimizes both cost and health impacts. The reduced-form model captures the response of spatially resolved air pollutant concentrations to changes in electricity-generating plant emissions on an hourly basis with accuracy comparable to a comprehensive air quality model. The integrated model allows for the inclusion of human health impacts into cost-based decisions for power plant operation. We use the new capability in a case study of the state of Georgia over the years of 2004-2011, and show that a shift in utilization among existing power plants during selected hourly periods could have provided a health cost savings of $175.9 million dollars for an additional electricity generation cost of $83.6 million in 2007 US dollars (USD2007). The case study illustrates how air pollutant health impacts can be cost-effectively minimized by intelligently modulating power plant operations over multihour periods, without implementing additional emissions control technologies.
Kerl, Paul Y.; Zhang, Wenxian; Moreno-Cruz, Juan B.; Nenes, Athanasios; Realff, Matthew J.; Russell, Armistead G.; Sokol, Joel; Thomas, Valerie M.
2015-01-01
Integrating accurate air quality modeling with decision making is hampered by complex atmospheric physics and chemistry and its coupling with atmospheric transport. Existing approaches to model the physics and chemistry accurately lead to significant computational burdens in computing the response of atmospheric concentrations to changes in emissions profiles. By integrating a reduced form of a fully coupled atmospheric model within a unit commitment optimization model, we allow, for the first time to our knowledge, a fully dynamical approach toward electricity planning that accurately and rapidly minimizes both cost and health impacts. The reduced-form model captures the response of spatially resolved air pollutant concentrations to changes in electricity-generating plant emissions on an hourly basis with accuracy comparable to a comprehensive air quality model. The integrated model allows for the inclusion of human health impacts into cost-based decisions for power plant operation. We use the new capability in a case study of the state of Georgia over the years of 2004–2011, and show that a shift in utilization among existing power plants during selected hourly periods could have provided a health cost savings of $175.9 million dollars for an additional electricity generation cost of $83.6 million in 2007 US dollars (USD2007). The case study illustrates how air pollutant health impacts can be cost-effectively minimized by intelligently modulating power plant operations over multihour periods, without implementing additional emissions control technologies. PMID:26283358
High-power narrow-linewidth quasi-CW diode-pumped TEM00 1064 nm Nd:YAG ring laser.
Liu, Yuan; Wang, Bao-shan; Xie, Shi-yong; Bo, Yong; Wang, Peng-yuan; Zuo, Jun-wei; Xu, Yi-ting; Xu, Jia-lin; Peng, Qin-jun; Cui, Da-fu; Xu, Zu-yan
2012-04-01
We demonstrated a high average power, narrow-linewidth, quasi-CW diode-pumped Nd:YAG 1064 nm laser with near-diffraction-limited beam quality. A symmetrical three-mirror ring cavity with unidirectional operation elements and an etalon was employed to realize the narrow-linewidth laser output. Two highly efficient laser modules and a 90° quartz rotator for birefringence compensation were used for the high output power. The maximum average output power of 62.5 W with the beam quality factor M(2) of 1.15 was achieved under a pump power of 216 W at a repetition rate of 500 Hz, corresponding to the optical-to-optical conversion efficiency of 28.9%. The linewidth of the laser at the maximum output power was measured to be less than 0.2 GHz.
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.
Dante, Angelo; Fabris, Stefano; Palese, Alvisa
2015-01-01
Academic failure is the inability of a nursing student to graduate or to complete the nursing degree on time. This longitudinal cohort study, involving 2 Italian universities, documents the effects of selected individual variables and the quality of the clinical learning experience as perceived by students on academic success. Factors related to the clinical learning experience were the quality of the supervisory relationship, pedagogical atmosphere, and commitment of the ward related to the level of personalized nursing care delivered and clarity of nursing documentation.
Investigation on scalable high-power lasers with enhanced 'eye-safety' for future weapon systems
NASA Astrophysics Data System (ADS)
Bigotta, S.; Diener, K.; Eichhorn, M.; Galecki, L.; Geiss, L.; Ibach, T.; Scharf, H.; von Salisch, M.; Schöner, J.; Vincent, G.
2016-10-01
The possible use of lasers as weapons becomes more and more interesting for military forces. Besides the generation of high laser power and good beam quality, also safety considerations, e. g. concerning eye hazards, are of importance. The MELIAS (medium energy laser in the "eye-safe" spectral domain) project of ISL addresses these issues, and ISL has developed the most powerful solid-state laser in the "eye-safe" wavelength region up to now. "Eye safety" in this context means that light at a wavelength of > 1.4 μm does not penetrate the eye and thus will not be focused onto the retina. The basic principle of this technology is that a laser source needs to be scalable in power to far beyond 100 kW without a significant deterioration in beam quality. ISL has studied a very promising laser technology: the erbium heat-capacity laser. This type of laser is characterised by a compact design, a simple and robust technology and a scaling law which, in principle, allows the generation of laser power far beyond megawatts at small volumes. Previous investigations demonstrated the scalability of the SSHCL and up to 4.65 kW and 440 J in less than 800 ms have been obtained. Opticalto- optical efficiencies of over 41% and slope efficiencies of over 51% are obtained. The residual thermal gradients, due to non perfect pumping homogeneity, negatively affect the performance in terms of laser pulse energy, duration and beam quality. In the course of the next two years, ISL will be designing a 25 to 30 kW erbium heat-capacity laser.
UYAMA, Sachie; HANAKI, Keiichi
2016-01-01
[Purpose] This study aimed to elucidate the actual state of powered wheelchair (PWC) prescription for preschool children with disabilities in Japan, and also to determine the approximate number of preschool children with disabilities who would potentially benefit from PWC use. [Subjects and Methods] A total of 318 facilities providing rehabilitation for disabled children in Japan were enrolled in the study. A questionnaire about PWC use for preschoolers was mailed to the facilities. Each study items were analyzed employing the Fisher's exact test. [Results] Of the 318 facilities, consent to participate in this study was obtained from 108 (return rate: 34.0%). After PWC provision, many facilities reported improvement in quality of life indices for preschool children with disabilities. It was revealed that there were 6 preschool children from 2 to 6 years of age with disabilities who might acquire a means of independent locomotion through PWC provision and thereby experience improved quality of life. [Conclusion] There was no negative comment from the facilities studied about the prescription and provision of PWC for preschool children with disabilities. PMID:28289577
Akhbari, Maryam; Masoum, Saeed; Aghababaei, Fahimeh; Hamedi, Sepideh
2018-06-01
In this study, the efficiencies of conventional hydro-distillation and novel microwave hydro-distillation methods in extraction of essential oil from Rosemary officinalis leaves have been compared. In order to attain the best yield and also highest quality of the essential oil in the microwave assisted method, the optimal values of operating parameters such as extraction time, microwave irradiation power and water volume to plant mass ratio were investigated using central composite design under response surface methodology. Optimal conditions for obtaining the maximum extraction yield in the microwave assisted method were predicted as follows: extraction time of 85 min, microwave power of 888 W, and water volume to plant mass ratio of 0.5 ml/g. The extraction yield at these predicted conditions was computed as 0.7756%. The qualities of the obtained essential oils under designed experiments were optimized based on total contents of four major compounds (α-pinene, 1,8-cineole, camphor and verbenone) which determined by gas chromatography equipped with mass spectroscopy (GC-MS). The highest essential oil quality (55.87%) was obtained at extraction time of 68 min; microwave irradiation power of 700 W; and water volume to plant mass ratio of zero.
Code of Federal Regulations, 2010 CFR
2010-04-01
... water quality management and control. However, protection of the water resources of the basin from... quality program in the comprehensive plan. (c) The Commission's role in water quality management and... 18 Conservation of Power and Water Resources 2 2010-04-01 2010-04-01 false Water quality. 801.7...
Chen, Yi-Ting; Horng, Mong-Fong; Lo, Chih-Cheng; Chu, Shu-Chuan; Pan, Jeng-Shyang; Liao, Bin-Yih
2013-03-20
Transmission power optimization is the most significant factor in prolonging the lifetime and maintaining the connection quality of wireless sensor networks. Un-optimized transmission power of nodes either interferes with or fails to link neighboring nodes. The optimization of transmission power depends on the expected node degree and node distribution. In this study, an optimization approach to an energy-efficient and full reachability wireless sensor network is proposed. In the proposed approach, an adjustment model of the transmission range with a minimum node degree is proposed that focuses on topology control and optimization of the transmission range according to node degree and node density. The model adjusts the tradeoff between energy efficiency and full reachability to obtain an ideal transmission range. In addition, connectivity and reachability are used as performance indices to evaluate the connection quality of a network. The two indices are compared to demonstrate the practicability of framework through simulation results. Furthermore, the relationship between the indices under the conditions of various node degrees is analyzed to generalize the characteristics of node densities. The research results on the reliability and feasibility of the proposed approach will benefit the future real deployments.
Chen, Yi-Ting; Horng, Mong-Fong; Lo, Chih-Cheng; Chu, Shu-Chuan; Pan, Jeng-Shyang; Liao, Bin-Yih
2013-01-01
Transmission power optimization is the most significant factor in prolonging the lifetime and maintaining the connection quality of wireless sensor networks. Un-optimized transmission power of nodes either interferes with or fails to link neighboring nodes. The optimization of transmission power depends on the expected node degree and node distribution. In this study, an optimization approach to an energy-efficient and full reachability wireless sensor network is proposed. In the proposed approach, an adjustment model of the transmission range with a minimum node degree is proposed that focuses on topology control and optimization of the transmission range according to node degree and node density. The model adjusts the tradeoff between energy efficiency and full reachability to obtain an ideal transmission range. In addition, connectivity and reachability are used as performance indices to evaluate the connection quality of a network. The two indices are compared to demonstrate the practicability of framework through simulation results. Furthermore, the relationship between the indices under the conditions of various node degrees is analyzed to generalize the characteristics of node densities. The research results on the reliability and feasibility of the proposed approach will benefit the future real deployments. PMID:23519351
Work on power-plant (air) plumes involving remote sensing of SO2
NASA Technical Reports Server (NTRS)
White, C. L., Jr.
1978-01-01
Acquisition of air quality and concurrent meteorological data was used for dispersion model development and plant siting needs of the Maryland power plants. One of the major instruments in these studies was the Barringer correlation spectrometer, a remote sensor, using atmospherically scattered sunlight that was used to measure the total amount of SO2 in a cross section of the plume. Correlation spectrometer and its role in this measurement program are described.
Control of Solar Power Plants Connected Grid with Simple Calculation Method on Residential Homes
NASA Astrophysics Data System (ADS)
Kananda, Kiki; Nazir, Refdinal
2017-12-01
One of the most compatible renewable energy in all regions to apply is solar energy. Solar power plants can be built connected to existing or stand-alone power grids. In assisting the residential electricity in which there is a power grid, then a small scale solar energy power plants is very appropriate. However, the general constraint of solar energy power plants is still low in terms of efficiency. Therefore, this study will explain how to control the power of solar power plants more optimally, which is expected to reactive power to zero to raise efficiency. This is a continuation of previous research using Newton Rapshon control method. In this study we introduce a simple method by using ordinary mathematical calculations of solar-related equations. In this model, 10 PV modules type of ND T060M1 with a 60 Wp capacity are used. The calculations performed using MATLAB Simulink provide excellent value. For PCC voltage values obtained a stable quantity of approximately 220 V. At a maximum irradiation condition of 1000 W / m2, the reactive power value of Q solar generating system maximum 20.48 Var and maximum active power of 417.5 W. In the condition of lower irradiation, value of reactive power Q almost close to zero 0.77Var. This simple mathematical method can provide excellent quality control power values.
NASA Astrophysics Data System (ADS)
Choubey, Ambar; Vishwakarma, S. C.; Vachhani, D. M.; Singh, Ravindra; Misra, Pushkar; Jain, R. K.; Arya, R.; Upadhyaya, B. N.; Oak, S. M.
2014-11-01
Free running short pulse Nd:YAG laser of microsecond pulse duration and high peak power has a unique capability to ablate material from the surface without heat propagation into the bulk. Applications of short pulse Nd:YAG lasers include cleaning and restoration of marble, stones, and a variety of metals for conservation. A study on the development of high peak power short pulses from Nd:YAG laser along with its cleaning and conservation applications has been performed. A pulse energy of 1.25 J with 55 μs pulse duration and a maximum peak power of 22 kW has been achieved. Laser beam has an M2 value of ~28 and a pulse-to-pulse stability of ±2.5%. A lower value of M2 means a better beam quality of the laser in multimode operation. A top hat spatial profile of the laser beam was achieved at the exit end of 200 μm core diameter optical fiber, which is desirable for uniform cleaning. This laser system has been evaluated for efficient cleaning of surface contaminations on marble, zircaloy, and inconel materials for conservation with cleaning efficiency as high as 98%. Laser's cleaning quality and efficiency have been analysed by using a microscope, a scanning electron microscope (SEM), and X-ray photon spectroscopy (XPS) measurements.
Universities scale like cities.
van Raan, Anthony F J
2013-01-01
Recent studies of urban scaling show that important socioeconomic city characteristics such as wealth and innovation capacity exhibit a nonlinear, particularly a power law scaling with population size. These nonlinear effects are common to all cities, with similar power law exponents. These findings mean that the larger the city, the more disproportionally they are places of wealth and innovation. Local properties of cities cause a deviation from the expected behavior as predicted by the power law scaling. In this paper we demonstrate that universities show a similar behavior as cities in the distribution of the 'gross university income' in terms of total number of citations over 'size' in terms of total number of publications. Moreover, the power law exponents for university scaling are comparable to those for urban scaling. We find that deviations from the expected behavior can indeed be explained by specific local properties of universities, particularly the field-specific composition of a university, and its quality in terms of field-normalized citation impact. By studying both the set of the 500 largest universities worldwide and a specific subset of these 500 universities--the top-100 European universities--we are also able to distinguish between properties of universities with as well as without selection of one specific local property, the quality of a university in terms of its average field-normalized citation impact. It also reveals an interesting observation concerning the working of a crucial property in networked systems, preferential attachment.
A Metric-Based Validation Process to Assess the Realism of Synthetic Power Grids
DOE Office of Scientific and Technical Information (OSTI.GOV)
Birchfield, Adam; Schweitzer, Eran; Athari, Mir
Public power system test cases that are of high quality benefit the power systems research community with expanded resources for testing, demonstrating, and cross-validating new innovations. Building synthetic grid models for this purpose is a relatively new problem, for which a challenge is to show that created cases are sufficiently realistic. This paper puts forth a validation process based on a set of metrics observed from actual power system cases. These metrics follow the structure, proportions, and parameters of key power system elements, which can be used in assessing and validating the quality of synthetic power grids. Though wide diversitymore » exists in the characteristics of power systems, the paper focuses on an initial set of common quantitative metrics to capture the distribution of typical values from real power systems. The process is applied to two new public test cases, which are shown to meet the criteria specified in the metrics of this paper.« less
A Metric-Based Validation Process to Assess the Realism of Synthetic Power Grids
Birchfield, Adam; Schweitzer, Eran; Athari, Mir; ...
2017-08-19
Public power system test cases that are of high quality benefit the power systems research community with expanded resources for testing, demonstrating, and cross-validating new innovations. Building synthetic grid models for this purpose is a relatively new problem, for which a challenge is to show that created cases are sufficiently realistic. This paper puts forth a validation process based on a set of metrics observed from actual power system cases. These metrics follow the structure, proportions, and parameters of key power system elements, which can be used in assessing and validating the quality of synthetic power grids. Though wide diversitymore » exists in the characteristics of power systems, the paper focuses on an initial set of common quantitative metrics to capture the distribution of typical values from real power systems. The process is applied to two new public test cases, which are shown to meet the criteria specified in the metrics of this paper.« less
Wet etching technique for fabrication of a high-quality plastic optical fiber sensor.
Zhao, Mingfu; Dai, Lang; Zhong, Nianbing; Wang, Zhengkun; Chen, Ming; Li, Bingxin; Luo, Binbin; Tang, Bin; Shi, Shenghui; Song, Tao; Zou, Xue
2017-11-01
In this study, a simple wet etching technique is developed by employing aqueous solutions of acetic acid and ultrasonic irradiation for the fabrication of a high-quality plastic optical fiber (POF) sensor. The effects of acetic acid concentration and temperature and ultrasonic power on the etching rate and surface morphology of the etched POFs are investigated. The transmission spectrum and sensitivity of the etched POF sensors are evaluated using glucose solutions. We discovered that the POF sensors, which are fabricated using an aqueous solution of acetic acid with a concentration of 80 vol. % under an ultrasonic power of 130 W and temperature of 25°C, exhibit good light transmission and a high sensitivity of 9.10 [(RIU)(g/L)] -1 in the glucose solutions.
An Energy Saving Green Plug Device for Nonlinear Loads
NASA Astrophysics Data System (ADS)
Bloul, Albe; Sharaf, Adel; El-Hawary, Mohamed
2018-03-01
The paper presents a low cost a FACTS Based flexible fuzzy logic based modulated/switched tuned arm filter and Green Plug compensation (SFC-GP) scheme for single-phase nonlinear loads ensuring both voltage stabilization and efficient energy utilization. The new Green Plug-Switched filter compensator SFC modulated LC-Filter PWM Switched Capacitive Compensation Devices is controlled using a fuzzy logic regulator to enhance power quality, improve power factor at the source and reduce switching transients and inrush current conditions as well harmonic contents in source current. The FACTS based SFC-GP Device is a member of family of Green Plug/Filters/Compensation Schemes used for efficient energy utilization, power quality enhancement and voltage/inrush current/soft starting control using a dynamic error driven fuzzy logic controller (FLC). The device with fuzzy logic controller is validated using the Matlab / Simulink Software Environment for enhanced power quality (PQ), improved power factor and reduced inrush currents. This is achieved using modulated PWM Switching of the Filter-Capacitive compensation scheme to cope with dynamic type nonlinear and inrush cyclical loads..
Purity of Vector Vortex Beams through a Birefringent Amplifier
NASA Astrophysics Data System (ADS)
Sroor, Hend; Lisa, Nyameko; Naidoo, Darryl; Litvin, Igor; Forbes, Andrew
2018-04-01
Creating high-quality vector vortex (VV) beams is possible with a myriad of techniques at low power, and while a few studies have produced such beams at high power, none have considered the impact of amplification on the vector purity. Here we employ tools to study the amplification of VV beams and, in particular, the purity of such modes. We outline a versatile toolbox for such investigations and demonstrate its use in the general case of VV beams through a birefringent gain medium. Intriguingly, we show that it is possible to enhance the purity of such beams during amplification, paving the way for high-brightness VV beams, a requirement for their use in high-power applications such as optical communication and laser-enabled manufacturing.
A Piloted Simulator Evaluation of Transport Aircraft Rudder Pedal Force/Feel Characteristics
NASA Technical Reports Server (NTRS)
Stewart, Eric C.
2008-01-01
A piloted simulation study has been conducted in a fixed-base research simulator to assess the directional handling qualities for various rudder pedal feel characteristics for commercial transport airplanes. That is, the effects of static pedal force at maximum pedal travel, breakout force, and maximum pedal travel on handling qualities were studied. An artificial maneuver with a severe lateral wind shear and requiring runway tracking at an altitude of 50 feet in a crosswind was used to fully exercise the rudder pedals. Twelve active airline pilots voluntarily participated in the study and flew approximately 500 maneuvers. The pilots rated the maneuver performance with various rudder pedal feel characteristics using the Cooper- Harper rating scale. The test matrix had 15 unique combinations of the 3 static pedal feel characteristics. A 10-term, second-order equation for the Cooper-Harper pilot rating as a function of the 3 independent pedal feel parameters was fit to the data. The test matrix utilized a Central Composite Design that is very efficient for fitting an equation of this form. The equation was used to produce contour plots of constant pilot ratings as a function of two of the parameters with the third parameter held constant. These contour plots showed regions of good handling qualities as well as regions of degraded handling qualities. In addition, a numerical equation solver was used to predict the optimum parameter values (those with the lowest pilot rating). Quantitative pilot performance data were also analyzed. This analysis found that the peak values of the cross power spectra of the pedal force and heading angle could be used to quantify the tendency toward directional pilot induced oscillations (PIO). Larger peak values of the cross power spectra were correlated with larger (degraded) Cooper-Harper pilot ratings. Thus, the subjective data (Cooper-Harper pilot ratings) were consistent with the objective data (peak values of the cross power spectra).
A low-power and high-quality implementation of the discrete cosine transformation
NASA Astrophysics Data System (ADS)
Heyne, B.; Götze, J.
2007-06-01
In this paper a computationally efficient and high-quality preserving DCT architecture is presented. It is obtained by optimizing the Loeffler DCT based on the Cordic algorithm. The computational complexity is reduced from 11 multiply and 29 add operations (Loeffler DCT) to 38 add and 16 shift operations (which is similar to the complexity of the binDCT). The experimental results show that the proposed DCT algorithm not only reduces the computational complexity significantly, but also retains the good transformation quality of the Loeffler DCT. Therefore, the proposed Cordic based Loeffler DCT is especially suited for low-power and high-quality CODECs in battery-based systems.
78 FR 37850 - Quality Assurance Program Requirements (Operations)
Federal Register 2010, 2011, 2012, 2013, 2014
2013-06-24
... NUCLEAR REGULATORY COMMISSION [NRC-2013-0021] Quality Assurance Program Requirements (Operations... Regulatory Commission (NRC) is issuing a revision to Regulatory Guide (RG) 1.33, ``Quality Assurance Program... managerial and administrative Quality Assurance (QA) controls for nuclear power plants during operations...
Performance evaluation of power control algorithms in wireless cellular networks
NASA Astrophysics Data System (ADS)
Temaneh-Nyah, C.; Iita, V.
2014-10-01
Power control in a mobile communication network intents to control the transmission power levels in such a way that the required quality of service (QoS) for the users is guaranteed with lowest possible transmission powers. Most of the studies of power control algorithms in the literature are based on some kind of simplified assumptions which leads to compromise in the validity of the results when applied in a real environment. In this paper, a CDMA network was simulated. The real environment was accounted for by defining the analysis area and the network base stations and mobile stations are defined by their geographical coordinates, the mobility of the mobile stations is accounted for. The simulation also allowed for a number of network parameters including the network traffic, and the wireless channel models to be modified. Finally, we present the simulation results of a convergence speed based comparative analysis of three uplink power control algorithms.
NASA Astrophysics Data System (ADS)
Zhao, Yan; Yang, Zijiang; Gao, Song; Liu, Jinbiao
2018-02-01
Automatic generation control(AGC) is a key technology to maintain real time power generation and load balance, and to ensure the quality of power supply. Power grids require each power generation unit to have a satisfactory AGC performance, being specified in two detailed rules. The two rules provide a set of indices to measure the AGC performance of power generation unit. However, the commonly-used method to calculate these indices is based on particular data samples from AGC responses and will lead to incorrect results in practice. This paper proposes a new method to estimate the AGC performance indices via system identification techniques. In addition, a nonlinear regression model between performance indices and load command is built in order to predict the AGC performance indices. The effectiveness of the proposed method is validated through industrial case studies.
Power enhancement via multivariate outlier testing with gene expression arrays.
Asare, Adam L; Gao, Zhong; Carey, Vincent J; Wang, Richard; Seyfert-Margolis, Vicki
2009-01-01
As the use of microarrays in human studies continues to increase, stringent quality assurance is necessary to ensure accurate experimental interpretation. We present a formal approach for microarray quality assessment that is based on dimension reduction of established measures of signal and noise components of expression followed by parametric multivariate outlier testing. We applied our approach to several data resources. First, as a negative control, we found that the Affymetrix and Illumina contributions to MAQC data were free from outliers at a nominal outlier flagging rate of alpha=0.01. Second, we created a tunable framework for artificially corrupting intensity data from the Affymetrix Latin Square spike-in experiment to allow investigation of sensitivity and specificity of quality assurance (QA) criteria. Third, we applied the procedure to 507 Affymetrix microarray GeneChips processed with RNA from human peripheral blood samples. We show that exclusion of arrays by this approach substantially increases inferential power, or the ability to detect differential expression, in large clinical studies. http://bioconductor.org/packages/2.3/bioc/html/arrayMvout.html and http://bioconductor.org/packages/2.3/bioc/html/affyContam.html affyContam (credentials: readonly/readonly)
Systematic void fraction studies with RELAP5, FRANCESCA and HECHAN
DOE Office of Scientific and Technical Information (OSTI.GOV)
Stosic, Z.; Preusche, G.
1996-08-01
In enhancing the scope of standard thermal-hydraulic codes applications beyond its capabilities, i.e. coupling with a one and/or three-dimensional kinetics core model, the void fraction, transferred from thermal-hydraulics to the core model, plays a determining role in normal operating range and high core flow, as the generated heat and axial power profiles are direct functions of void distribution in the core. Hence, it is very important to know if the void quality models in the programs which have to be coupled are compatible to allow the interactive exchange of data which are based on these constitutive void-quality relations. The presentedmore » void fraction study is performed in order to give the basis for the conclusion whether a transient core simulation using the RELAP5 void fractions can calculate the axial power shapes adequately. Because of that, the void fractions calculated with RELAP5 are compared with those calculated by BWR safety code for licensing--FRANCESCA and the best estimate model for pre- and post-dryout calculation in BWR heated channel--HECHAN. In addition, a comparison with standard experimental void-quality benchmark tube data is performed for the HECHAN code.« less
Overview of Power Quality and Integrated Testing at JSC
NASA Technical Reports Server (NTRS)
Davies, Francis
2018-01-01
This presentation describes the basic philosophy behind integrated testing and partially integrated testing. It lists some well known errors in space systems that were or could have been caught during integrated testing. Two examples of integrated testing at the Johnson Space Center (JSC) are mentioned, and then an overview of two test facilities that do power testing (partially integrated testing) at JSC are presented, with information on the capabilities of each. Finally a list of three projects that has problems caught during power quality or Electromagnetic Interference (EMI) testing is presented.
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.
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).
Opportunities and Benefits for Powerchair Users Through Power Soccer.
Jeffress, Michael S; Brown, William J
2017-07-01
Power soccer (or powerchair football), the first competitive team sport for users of motorized wheelchairs, is receiving increased attention among people with disabilities, healthcare professionals, and academics. The present study provides a qualitative analysis of the experiences of 34 American power soccer athletes. Participant observation and in-depth interviews with 11 female and 23 male athletes were conducted between 2007 and 2013. Results indicate that involvement in power soccer provides participants with an increased sense of empowerment, acquisition of social capital, and psychosocial benefits, including a deep satisfaction of the desire to participate in competitive sports and an opportunity to be independent. Implications of these findings for improving the quality of life of people with physical disabilities and for future research are discussed.
The relationship between depressive symptoms among female workers and job stress and sleep quality.
Cho, Ho-Sung; Kim, Young-Wook; Park, Hyoung-Wook; Lee, Kang-Ho; Jeong, Baek-Geun; Kang, Yune-Sik; Park, Ki-Soo
2013-07-22
Recently, workers' mental health has become important focus in the field of occupational health management. Depression is a psychiatric illness with a high prevalence. The association between job stress and depressive symptoms has been demonstrated in many studies. Recently, studies about the association between sleep quality and depressive symptoms have been reported, but there has been no large-scaled study in Korean female workers. Therefore, this study was designed to investigate the relationship between job stress and sleep quality, and depressive symptoms in female workers. From Mar 2011 to Aug 2011, 4,833 female workers in the manufacturing, finance, and service fields at 16 workplaces in Yeungnam province participated in this study, conducted in combination with a worksite-based health checkup initiated by the National Health Insurance Service (NHIS). In this study, a questionnaire survey was carried out using the Korean Occupational Stress Scale-Short Form(KOSS-SF), Pittsburgh Sleep Quality Index(PSQI) and Center for Epidemiological Studies-Depression Scale(CES-D). The collected data was entered in the system and analyzed using the PASW (version 18.0) program. A correlation analysis, cross analysis, multivariate logistic regression analysis, and hierarchical multiple regression analysis were conducted. Among the 4,883 subjects, 978 subjects (20.0%) were in the depression group. Job stress(OR=3.58, 95% CI=3.06-4.21) and sleep quality(OR=3.81, 95% CI=3.18-4.56) were strongly associated with depressive symptoms. Hierarchical multiple regression analysis revealed that job stress displayed explanatory powers of 15.6% on depression while sleep quality displayed explanatory powers of 16.2%, showing that job stress and sleep quality had a closer relationship with depressive symptoms, compared to the other factors. The multivariate logistic regression analysis yielded odds ratios between the 7 subscales of job stress and depressive symptoms in the range of 1.30-2.72 and the odds ratio for the lack of reward was the highest(OR=2.72, 95% CI=2.32-3.19). In the partial correlation analysis between each of the 7 subscales of sleep quality (PSQI) and depressive symptoms, the correlation coefficient of subjective sleep quality and daytime dysfunction were 0.352 and 0.362, respectively. This study showed that the depressive symptoms of female workers are closely related to their job stress and sleep quality. In particular, the lack of reward and subjective sleep factors are the greatest contributors to depression. In the future, a large-scale study should be performed to augment the current study and to reflect all age groups in a balanced manner. The findings on job stress, sleep, and depression can be utilized as source data to establish standards for mental health management of the ever increasing numbers of female members of the workplace.
Applications of Wavelet Transform and Fuzzy Neural Network on Power Quality Recognition
NASA Astrophysics Data System (ADS)
Liao, Chiung-Chou; Yang, Hong-Tzer; Lin, Ying-Chun
2008-10-01
The wavelet transform coefficients (WTCs) contain plenty of information needed for transient event identification of power quality (PQ) events. However, adopting WTCs directly has the drawbacks of taking a longer time and too much memory for the recognition system. To solve the abovementioned recognition problems and to effectively reduce the number of features representing power transients, spectrum energies of WTCs in different scales are calculated by Parseval's Theorem. Through the proposed approach, features of the original power signals can be reserved and not influenced by occurring points of PQ events. The fuzzy neural classification systems are then used for signal recognition and fuzzy rule construction. Success rates of recognizing PQ events from noise-riding signals are proven to be feasible in power system applications in this paper.
Lanier, Steven T; Lewis, Kevin C; Kendall, Mark C; Vieira, Brittany L; De Oliveira, Gildasio; Nader, Anthony; Kim, John Y S; Alghoul, Mohammed
2018-03-01
The authors' study represents the first level I evidence to assess whether intraoperative nerve blocks improve the quality of recovery from immediate tissue expander/implant breast reconstruction. A prospective, randomized, double-blinded, placebo-controlled clinical trial was conducted in which patients undergoing immediate tissue expander/implant breast reconstruction were randomized to either (1) intraoperative intercostal and pectoral nerve blocks with 0.25% bupivacaine with 1:200,000 epinephrine and 4 mg of dexamethasone or (2) sham nerve blocks with normal saline. The 40-item Quality of Recovery score, pain score, and opioid use in the postoperative period were compared statistically between groups. Power analysis ensured 80 percent power to detect a 10-point (clinically significant) difference in the 40-item Quality of Recovery score. Forty-seven patients were enrolled. Age, body mass index, laterality, mastectomy type, and lymph node dissection were similar between groups. There were no statistical differences in quality of recovery, pain burden as measured by visual analogue scale, opioid consumption, antiemetic use, or length of hospital stay between groups at 24 hours after surgery. Mean global 40-item Quality of Recovery scores were 169 (range, 155 to 182) for the treatment arm and 165 (range, 143 to 179) for the placebo arm (p = 0.36), indicating a high quality of recovery in both groups. Although intraoperative nerve blocks can be a safe adjunct to a comprehensive postsurgical recovery regimen, the authors' results indicate no effect on overall quality of recovery from tissue expander/implant breast reconstruction. Therapeutic, I.
ERIC Educational Resources Information Center
Propper, Igno M. A. M.
1993-01-01
Proposes an instrument for assessing the extent to which either sound arguments or power are found in scientific and political discussions. Empirical research is described that investigated the relation between the quality of evaluation research and the quality of discussion in policy-making processes in which the research is used. (Contains 47…
Social Power: Effect on Spouses' Quality of Personal Life.
ERIC Educational Resources Information Center
Thomas, Cher Carrie
It is the dimension of power or control, either in the workplace or in the family, that determines the degree to which social relations are alienating. The consequences of social inequality for the quality of personal life were examined in 314 married couples, of whom 70 were dual-earning non-parents, 123 were dual-earning parents, and 41 were…
Assessing I-Grid(TM) web-based monitoring for power quality and reliability benchmarking
DOE Office of Scientific and Technical Information (OSTI.GOV)
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].
Code of Federal Regulations, 2010 CFR
2010-04-01
... 18 Conservation of Power and Water Resources 2 2010-04-01 2010-04-01 false Basin regulations-Water Code and Administrative Manual-Part III Water Quality Regulations. 410.1 Section 410.1 Conservation of Power and Water Resources DELAWARE RIVER BASIN COMMISSION ADMINISTRATIVE MANUAL BASIN REGULATIONS; WATER CODE AND ADMINISTRATIVE MANUAL-PART III...
Code of Federal Regulations, 2014 CFR
2014-04-01
... 18 Conservation of Power and Water Resources 2 2014-04-01 2014-04-01 false Basin regulations-Water Code and Administrative Manual-Part III Water Quality Regulations. 410.1 Section 410.1 Conservation of Power and Water Resources DELAWARE RIVER BASIN COMMISSION ADMINISTRATIVE MANUAL BASIN REGULATIONS; WATER CODE AND ADMINISTRATIVE MANUAL-PART III...
Code of Federal Regulations, 2013 CFR
2013-04-01
... 18 Conservation of Power and Water Resources 2 2013-04-01 2012-04-01 true Basin regulations-Water Code and Administrative Manual-Part III Water Quality Regulations. 410.1 Section 410.1 Conservation of Power and Water Resources DELAWARE RIVER BASIN COMMISSION ADMINISTRATIVE MANUAL BASIN REGULATIONS; WATER CODE AND ADMINISTRATIVE MANUAL-PART III...
Code of Federal Regulations, 2012 CFR
2012-04-01
... 18 Conservation of Power and Water Resources 2 2012-04-01 2012-04-01 false Basin regulations-Water Code and Administrative Manual-Part III Water Quality Regulations. 410.1 Section 410.1 Conservation of Power and Water Resources DELAWARE RIVER BASIN COMMISSION ADMINISTRATIVE MANUAL BASIN REGULATIONS; WATER CODE AND ADMINISTRATIVE MANUAL-PART III...
Power Quality Improvement Utilizing Photovoltaic Generation Connected to a Weak Grid
DOE Office of Scientific and Technical Information (OSTI.GOV)
Muljadi, Eduard; Tumbelaka, Hanny H.; Gao, Wenzhong
Microgrid research and development in the past decades have been one of the most popular topics. Similarly, the photovoltaic generation has been surging among renewable generation in the past few years, thanks to the availability, affordability, technology maturity of the PV panels and the PV inverter in the general market. Unfortunately, quite often, the PV installations are connected to weak grids and may have been considered as the culprit of poor power quality affecting other loads in particular sensitive loads connected to the same point of common coupling (PCC). This paper is intended to demystify the renewable generation, and turnsmore » the negative perception into positive revelation of the superiority of PV generation to the power quality improvement in a microgrid system. The main objective of this work is to develop a control method for the PV inverter so that the power quality at the PCC will be improved under various disturbances. The method is to control the reactive current based on utilizing the grid current to counteract the negative impact of the disturbances. The proposed control method is verified in PSIM platform. Promising results have been obtained.« less
NASA Astrophysics Data System (ADS)
Farid, Sidra; Stroscio, Michael A.; Dutta, Mitra
2018-03-01
Thermal evaporation growth technique is presented as a route to grow cost effective high quality CdS thin films. We have successfully grown high quality CdS thin films on ITO coated glass substrates by thermal evaporation technique and analyzed the effects of annealing and excitation dependent input of CdS thin film using Raman and photoluminescence spectroscopy. LO phonon modes have been analyzed quantitatively considering the contributions due to anneal induced effects on film quality using phonon spatial correlation model, line shape and defect state analysis. Asymmetry in the Raman line shape towards the low frequency side is related to the phonon confinement effects and is modeled by spatial correlation model. Calculations of width (FWHM), integrated intensity, and line shape for the longitudinal (LO) optical phonon modes indicate improved crystalline quality for the annealed films as compared to the as grown films. With increase in laser power, intensity ratio of 2-LO to 1-LO optical phonon modes is found to increase while multiple overtones upto fourth order are observed. Power dependent photoluminescence data indicates direct band-to-band transition in CdS thin films.
NASA Astrophysics Data System (ADS)
Liu, Yang; Zhang, Jian; Pang, Zhicong; Wu, Weihui
2018-04-01
Selective laser melting (SLM) provides a feasible way for manufacturing of complex thin-walled parts directly, however, the energy input during SLM process, namely derived from the laser power, scanning speed, layer thickness and scanning space, etc. has great influence on the thin wall's qualities. The aim of this work is to relate the thin wall's parameters (responses), namely track width, surface roughness and hardness to the process parameters considered in this research (laser power, scanning speed and layer thickness) and to find out the optimal manufacturing conditions. Design of experiment (DoE) was used by implementing composite central design to achieve better manufacturing qualities. Mathematical models derived from the statistical analysis were used to establish the relationships between the process parameters and the responses. Also, the effects of process parameters on each response were determined. Then, a numerical optimization was performed to find out the optimal process set at which the quality features are at their desired values. Based on this study, the relationship between process parameters and SLMed thin-walled structure was revealed and thus, the corresponding optimal process parameters can be used to manufactured thin-walled parts with high quality.
77 FR 34093 - License Renewal for Calvert Cliffs Nuclear Power Plant, LLC's
Federal Register 2010, 2011, 2012, 2013, 2014
2012-06-08
... quality; water quality and use; geology and soils; ecology; noise; historical and cultural; scenic and... significantly affect the quality of the human environment. Therefore, preparation of an environmental impact...
A new quality of bone ultrasound research.
Gluer, C C
2008-07-01
Quantitative ultrasound (QUS) methods have strong power to predict osteoporotic fractures, but they are also very relevant for the assessment of bone quality. A representative sample of recent studies addressing these topics can be found in this special issue. Further pursuit of these methods will establish micro-QUS imaging methods as tools for measuring specific aspects of bone quality. Once this is achieved, we will be able to link such data to the clinical QUS methods used in vivo to determine which aspects of bone quality cause QUS to be a predictor of fracture risk that is independent of bone mineral density (BMD). Potentially this could lead to the development of a new generation of QUS devices for improved and expanded clinical assessment. Good quality of basic science work will thus lead to good quality of clinical patient examinations on the basis of a more detailed assessment of bone quality.
Radiation Hardened, Modulator ASIC for High Data Rate Communications
NASA Technical Reports Server (NTRS)
McCallister, Ron; Putnam, Robert; Andro, Monty; Fujikawa, Gene
2000-01-01
Satellite-based telecommunication services are challenged by the need to generate down-link power levels adequate to support high quality (BER approx. equals 10(exp 12)) links required for modem broadband data services. Bandwidth-efficient Nyquist signaling, using low values of excess bandwidth (alpha), can exhibit large peak-to-average-power ratio (PAPR) values. High PAPR values necessitate high-power amplifier (HPA) backoff greater than the PAPR, resulting in unacceptably low HPA efficiency. Given the high cost of on-board prime power, this inefficiency represents both an economical burden, and a constraint on the rates and quality of data services supportable from satellite platforms. Constant-envelope signals offer improved power-efficiency, but only by imposing a severe bandwidth-efficiency penalty. This paper describes a radiation- hardened modulator which can improve satellite-based broadband data services by combining the bandwidth-efficiency of low-alpha Nyquist signals with high power-efficiency (negligible HPA backoff).
Wang, Qianggang; Zhou, Niancheng; Lou, Xiaoxuan; Chen, Xu
2014-01-01
Unbalanced grid faults will lead to several drawbacks in the output power quality of photovoltaic generation (PV) converters, such as power fluctuation, current amplitude swell, and a large quantity of harmonics. The aim of this paper is to propose a flexible AC current generation method by selecting coefficients to overcome these problems in an optimal way. Three coefficients are brought in to tune the output current reference within the required limits of the power quality (the current harmonic distortion, the AC current peak, the power fluctuation, and the DC voltage fluctuation). Through the optimization algorithm, the coefficients can be determined aiming to generate the minimum integrated amplitudes of the active and reactive power references with the constraints of the inverter current and DC voltage fluctuation. Dead-beat controller is utilized to track the optimal current reference in a short period. The method has been verified in PSCAD/EMTDC software.
Wang, Qianggang; Zhou, Niancheng; Lou, Xiaoxuan; Chen, Xu
2014-01-01
Unbalanced grid faults will lead to several drawbacks in the output power quality of photovoltaic generation (PV) converters, such as power fluctuation, current amplitude swell, and a large quantity of harmonics. The aim of this paper is to propose a flexible AC current generation method by selecting coefficients to overcome these problems in an optimal way. Three coefficients are brought in to tune the output current reference within the required limits of the power quality (the current harmonic distortion, the AC current peak, the power fluctuation, and the DC voltage fluctuation). Through the optimization algorithm, the coefficients can be determined aiming to generate the minimum integrated amplitudes of the active and reactive power references with the constraints of the inverter current and DC voltage fluctuation. Dead-beat controller is utilized to track the optimal current reference in a short period. The method has been verified in PSCAD/EMTDC software. PMID:25243215
Modeling of static and flowing-gas diode pumped alkali lasers
NASA Astrophysics Data System (ADS)
Barmashenko, Boris D.; Auslender, Ilya; Yacoby, Eyal; Waichman, Karol; Sadot, Oren; Rosenwaks, Salman
2016-03-01
Modeling of static and flowing-gas subsonic, transonic and supersonic Cs and K Ti:Sapphire and diode pumped alkali lasers (DPALs) is reported. A simple optical model applied to the static K and Cs lasers shows good agreement between the calculated and measured dependence of the laser power on the incident pump power. The model reproduces the observed threshold pump power in K DPAL which is much higher than that predicted by standard models of the DPAL. Scaling up flowing-gas DPALs to megawatt class power is studied using accurate three-dimensional computational fluid dynamics model, taking into account the effects of temperature rise and losses of alkali atoms due to ionization. Both the maximum achievable power and laser beam quality are estimated for Cs and K lasers. The performance of subsonic and, in particular, supersonic DPALs is compared with that of transonic, where supersonic nozzle and diffuser are spared and high power mechanical pump (needed for recovery of the gas total pressure which strongly drops in the diffuser), is not required for continuous closed cycle operation. For pumping by beams of the same rectangular cross section, comparison between end-pumping and transverse-pumping shows that the output power is not affected by the pump geometry, however, the intensity of the output laser beam in the case of transverse-pumped DPALs is strongly non-uniform in the laser beam cross section resulting in higher brightness and better beam quality in the far field for the end-pumping geometry where the intensity of the output beam is uniform.
Photonic crystal fiber technology for compact fiber-delivered high-power ultrafast fiber lasers
NASA Astrophysics Data System (ADS)
Triches, Marco; Michieletto, Mattia; Johansen, Mette M.; Jakobsen, Christian; Olesen, Anders S.; Papior, Sidsel R.; Kristensen, Torben; Bondue, Magalie; Weirich, Johannes; Alkeskjold, Thomas T.
2018-02-01
Photonic crystal fiber (PCF) technology has radically impacted the scientific and industrial ultrafast laser market. Reducing platform dimensions are important to decrease cost and footprint while maintaining high optical efficiency. We present our recent work on short 85 μm core ROD-type fiber amplifiers that maintain single-mode performance and excellent beam quality. Robust long-term performance at 100 W average power and 250 kW peak power in 20 ps pulses at 1030 nm wavelength is presented, exceeding 500 h with stable performance in terms of both polarization and power. In addition, we present our recent results on hollow-core ultrafast fiber delivery maintaining high beam quality and polarization purity.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Kodaira, S., E-mail: koda@nirs.go.jp; Kurano, M.; Hosogane, T.
A CR-39 plastic nuclear track detector was used for quality assurance of mixed oxide fuel pellets for next-generation nuclear power plants. Plutonium (Pu) spot sizes and concentrations in the pellets are significant parameters for safe use in the plants. We developed an automatic Pu detection system based on dense α-radiation tracks in the CR-39 detectors. This system would greatly improve image processing time and measurement accuracy, and will be a powerful tool for rapid pellet quality assurance screening.
Living near nuclear power plants and thyroid cancer risk: A systematic review and meta-analysis.
Kim, Jaeyoung; Bang, Yejin; Lee, Won Jin
2016-02-01
There has been public concern regarding the safety of residing near nuclear power plants, and the extent of risk for thyroid cancer among adults living near nuclear power plants has not been fully explored. In the present study, a systematic review and meta-analysis of epidemiologic studies was conducted to investigate the association between living near nuclear power plants and the risk of thyroid cancer. A comprehensive literature search was performed on studies published up to March 2015 on the association between nuclear power plants and thyroid cancer risk. The summary standardized incidence ratio (SIR), standardized mortality ratio (SMR), and 95% confidence intervals (CIs) were calculated using a random-effect model of meta-analysis. Sensitivity analyses were performed by study quality. Thirteen studies were included in the meta-analysis, covering 36 nuclear power stations in 10 countries. Overall, summary estimates showed no significant increased thyroid cancer incidence or mortality among residents living near nuclear power plants (summary SIR=0.98; 95% CI 0.87-1.11, summary SMR=0.80; 95% CI 0.62-1.04). The pooled estimates did not reveal different patterns of risk by gender, exposure definition, or reference population. However, sensitivity analysis by exposure definition showed that living less than 20 km from nuclear power plants was associated with a significant increase in the risk of thyroid cancer in well-designed studies (summary OR=1.75; 95% CI 1.17-2.64). Our study does not support an association between living near nuclear power plants and risk of thyroid cancer but does support a need for well-designed future studies. Copyright © 2015 Elsevier Ltd. All rights reserved.
Schivley, Greg; Ingwersen, Wesley W; Marriott, Joe; Hawkins, Troy R; Skone, Timothy J
2015-07-07
Improvements to coal power plant technology and the cofired combustion of biomass promise direct greenhouse gas (GHG) reductions for existing coal-fired power plants. Questions remain as to what the reduction potentials are from a life cycle perspective and if it will result in unintended increases in impacts to air and water quality and human health. This study provides a unique analysis of the potential environmental impact reductions from upgrading existing subcritical pulverized coal power plants to increase their efficiency, improving environmental controls, cofiring biomass, and exporting steam for industrial use. The climate impacts are examined in both a traditional-100 year GWP-method and a time series analysis that accounts for emission and uptake timing over the life of the power plant. Compared to fleet average pulverized bed boilers (33% efficiency), we find that circulating fluidized bed boilers (39% efficiency) may provide GHG reductions of about 13% when using 100% coal and reductions of about 20-37% when cofiring with 30% biomass. Additional greenhouse gas reductions from combined heat and power are minimal if the steam coproduct displaces steam from an efficient natural gas boiler. These upgrades and cofiring biomass can also reduce other life cycle impacts, although there may be increased impacts to water quality (eutrophication) when using biomass from an intensely cultivated source. Climate change impacts are sensitive to the timing of emissions and carbon sequestration as well as the time horizon over which impacts are considered, particularly for long growth woody biomass.
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 used to investigate the effects of the various solar generation scenarios given emissions projections that account for changing regulatory environment, economic and population growth, and technological change. The results will help to quantify the potential air quality benefits of promotion of solar electricity generation in regions containing high penetration of coal-fired power generation. Note current national solar incentives that are based only on solar generation capacity. Further investigation of changes to regional climate due to emission reductions of aerosols and relevant precursors will provide insight into the environmental effects that may occur if solar power generation becomes widespread.
Kiran, K R; Ravi, M V; Dhanya, B; Janagoudar, B S; Umesh, M R; Narayanarao, K
2016-09-01
In the present study, ambient air quality was monitored during July to November 2013 in the vicinity of Bellary Thermal Power Station (BTPS), Karnataka to assess the impact of pollutants emitted from power plant on the productivity of maize (Zea mays L.). Atmospheric pollutant load were measured in five different villages at varying distances and directions from thermal power plant, with the village farthest away from BTPS (Yelubenchi) as control. Maize yield was also estimated in these locations and correlated to the pollutant concentrations. It was found that, both particulate matter and SO2 which are indicators of emissions from coal-fueled power plants were highest in Thimmalapur village located in the predominant down wind direction. A significant reduction in maize yield was noticed (8197 to 6509 kg ha-1 for seed and 14041 to 9933 kg ha-1 for stover) across the gradient in distance and direction from BTPS which might be influenced by the pollutants emitted. The implications of these observations are further discussed in the paper.
Professionalism and professional quality of life for oncology nurses.
Jang, Insil; Kim, Yuna; Kim, Kyunghee
2016-10-01
To identify the relationship between professionalism and professional quality of life among oncology nurses working at tertiary hospitals in Korea. Oncology nurses are combined with core competencies and qualities required in cancer patient care. Professionalism that means compassion satisfaction and compassion fatigue is a main concept in problem-solving strategies as motivation. Their satisfaction is representative of professionalism and professional quality of life. However, little research has focused on professionalism and professional quality of life. A cross-sectional study with self-administered questionnaires. A total of 285 nurses from two tertiary hospitals were included. Data collection was undertaken using Korean version of professionalism scale derived from the Hall Professional Inventory Scale and professional quality of life. Data were analysed by spss 21.0 for Windows Program using t-test, anova, and multiple regression. The mean score of professionalism in oncology nurses was 77·98 ± 7·31. The mean professional quality of life score for compassion satisfaction, compassion fatigue and secondary traumatic stress was 33·84 ± 5·62, 28·38 ± 5·36 and 28·33 ± 5·48. Compassion satisfaction was affected by factors of professionalism with an explanatory power of 49·2%. Burnout and secondary traumatic stress were affected by factors of professionalism with an explanatory power of 39·3% and 4·8%. The higher the professionalism leads to the higher the compassion satisfaction, the lower the compassion fatigue. The relationship between professionalism and professional quality of life for a health work environment requires further investigation. Our study supports the idea that enhancing professionalism can increase professional quality of life. It is necessary to develop professionalism by recognised qualifications and applied rewards in advanced nursing organisational culture. Furthermore, compassion satisfaction is increased by continuing ethical and moral education programme for clinical nurses to force professional dedication and encouraging nurses to affiliate themselves with the professional communities. Nurses are connected to professionalism affect the quality of nursing service for patients and professional quality of life for themselves. © 2016 John Wiley & Sons Ltd.
Mickenautsch, Steffen; Yengopal, Veerasamy
2011-08-01
To investigate extent and quality of current systematic review evidence regarding: powered toothbrushes, triclosan toothpaste, essential oil mouthwashes, xylitol chewing gum. Five databases were searched for systematic reviews until 13 November 2010. relevant to topic, systematic review according to title and/or abstract, published in English. Article exclusion criteria were based on QUOROM recommendations for the reporting of systematic review methods. Systematic review quality was judged using the AMSTAR tool. All trials included by reviews were assessed for selection bias. 119 articles were found, of which 11 systematic reviews were included. Of these, six were excluded and five accepted: one for triclosan toothpaste; one for xylitol chewing gum; two for powered toothbrushes; one for essential oil mouthwashes. AMSTAR scores: triclosan toothpaste 7; powered toothbrushes 9 and 11; xylitol chewing gum 9; essential oil mouthwashes 8. In total, 75 (out of 76) reviewed trials were identified. In-depth assessment showed a high risk of selection bias for all trials. The extent of available systematic review evidence is low. Although the few identified systematic reviews could be rated as of medium and high quality, the validity of their conclusions needs to be treated with caution, owing to high risk of selection bias in the reviewed trials. High quality randomised control trials are needed in order to provide convincing evidence regarding true clinical efficacy. © 2011 FDI World Dental Federation.
Arduino Due based tool to facilitate in vivo two-photon excitation microscopy.
Artoni, Pietro; Landi, Silvia; Sato, Sebastian Sulis; Luin, Stefano; Ratto, Gian Michele
2016-04-01
Two-photon excitation spectroscopy is a powerful technique for the characterization of the optical properties of genetically encoded and synthetic fluorescent molecules. Excitation spectroscopy requires tuning the wavelength of the Ti:sapphire laser while carefully monitoring the delivered power. To assist laser tuning and the control of delivered power, we developed an Arduino Due based tool for the automatic acquisition of high quality spectra. This tool is portable, fast, affordable and precise. It allowed studying the impact of scattering and of blood absorption on two-photon excitation light. In this way, we determined the wavelength-dependent deformation of excitation spectra occurring in deep tissues in vivo.
NASA Astrophysics Data System (ADS)
How, Soo Ren; Nayan, Nafarizal; Khairul Ahmad, Mohd; Fhong Soon, Chin; Zainizan Sahdan, Mohd; Lias, Jais; Shuhaimi Abu Bakar, Ahmad; Arshad, Mohd Khairuddin Md; Hashim, Uda; Yazid Ahmad, Mohd
2018-04-01
The ion, electron density and electron temperature during formation of TiN films in reactive magnetron sputtering system have been investigated for various settings of radio frequency (RF) power and working pressure by using Langmuir probe measurements. The RF power and working pressure able to affect the densities and plasma properties during the deposition process. In this work, a working pressure (100 and 20 mTorr) and RF power (100, 150 and 200 W) have been used for data acquisition of probe measurement. Fundamental of studied on sputter deposition is very important for improvement of film quality and deposition rate. Higher working pressure and RF power able to produce a higher ion density and reduction of electron temperature.
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.
Generalship: Its Diseases and Their Cure. A Study of The Personal Factor in Command
1936-03-01
world- powers gave us quau- tity; now they are beginning to give us quality, motorization and mechanization, wbfeb in the end are as inevitable as the...Upped into a groove and became mate- riaIized. Mot increasing weapon- power alone, but the same factors which in in- dustry have led to a separation...special capacity for them, or to see that his plans were exe- cuted in accordance with his design and intention! Xo, his part was done; now he bad
NASA Technical Reports Server (NTRS)
Brown, B Porter
1958-01-01
Report presents results of tests made on a power control system by means of a ground simulator to determine the effects of various combinations of valve friction and stick friction on the ability of the pilot to control the system. Various friction conditions were simulated with a rigid control system, a flexible system, and a rigid system having some backlash. For the tests, the period and damping of the simulated airplane were held constant.
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.
NASA Astrophysics Data System (ADS)
Malleville, Marie-Alicia; Benoît, Aurélien; Dauliat, Romain; Leconte, Baptiste; Darwich, Dia; du Jeu, Rémi; Jamier, Raphaël.; Schwuchow, Anka; Schuster, Kay; Roy, Philippe
2018-02-01
Over the last decade, significant work has been carried out in order to increase the energy/peak power provided by fiber lasers. Indeed, new microstructured fibers with large (or very large) mode area cores (LMA) such as Distributed Mode Filtering (DMF) fibers and Large-Pitch Fibers (LPF) have been developed to address this concern. These technologies have allowed diffraction-limited emission with core diameters higher than 80 μm, and have state-of-the-art performances in terms of pulse energy or peak power while keeping an excellent spatial beam quality. Although these fibers were designed to reach high power levels while maintaining a single transverse mode propagation, power scaling becomes quickly limited by the onset of transverse modal instabilities (TMI). This effect suddenly arises when a certain average power threshold is exceeded, drastically degrading the emitted beam quality. In this work, we investigate the influence of the core dimensions and the refractive index mismatch between the active core and the background cladding material, on the TMI power threshold in rod-type Fully-Aperiodic-LPF. This fiber structure was specifically designed to enhance the higher-order modes (HOMs) delocalization out of the gain region and thus push further the onset of modal instabilities. Using a 400W pump diode at 976 nm, the power scaling, as well as the spatial beam quality and its temporal behavior were investigated in laser configuration, which theoretically provides a lower TMI power threshold than the amplifier one due to the lack of selective excitation of the fundamental mode.
ERIC Educational Resources Information Center
Blanco Ramírez, Gerardo
2014-01-01
Accountability and quality assurance have become central discourses in higher education policy throughout the world. However, accountability and quality assurance involve power and control. Practices and ideas about quality developed in the Global North are spreading rapidly across the Global South, leading to increased uniformity in the…
Drinking Patterns Among Older Couples: Longitudinal Associations With Negative Marital Quality.
Birditt, Kira S; Cranford, James A; Manalel, Jasmine A; Antonucci, Toni C
2018-04-16
Research with younger couples indicates that alcohol use has powerful effects on marital quality, but less work has examined the effects of drinking among older couples. This study examined whether dyadic patterns of drinking status among older couples are associated with negative marital quality over time. Married participants (N = 4864) from the Health and Retirement Study reported on alcohol consumption (whether they drink alcohol and average amount consumed per week) and negative marital quality (e.g., criticism and demands) across two waves (Wave 1 2006/2008 and Wave 2 2010/2012). Concordant drinking couples reported decreased negative marital quality over time, and these links were significantly greater among wives. Wives who reported drinking alcohol reported decreased negative marital quality over time when husbands also reported drinking and increased negative marital quality over time when husbands reported not drinking. The present findings stress the importance of considering the drinking status rather than the amount of alcohol consumed of both members of the couple when attempting to understand drinking and marital quality among older couples. These findings are particularly salient given the increased drinking among baby boomers and the importance of marital quality for health among older couples.
NASA Technical Reports Server (NTRS)
Mcneill, Walter, E.; Chung, William W.; Stortz, Michael W.
1995-01-01
A piloted motion simulator evaluation, using the NASA Ames Vertical Motion Simulator, was conducted in support of a NASA Lewis Contractual study of the integration of flight and propulsion systems of a STOVL aircraft. Objectives of the study were to validate the Design Methods for Integrated Control Systems (DMICS) concept, to evaluate the handling qualities, and to assess control power usage. The E-7D ejector-augmentor STOVL fighter design served as the basis for the simulation. Handling-qualities ratings were obtained during precision hover and shipboard landing tasks. Handling-qualities ratings for these tasks ranged from satisfactory to adequate. Further improvement of the design process to fully validate the DMICS concept appears to be warranted.
Wilcox, S.; Andreas, A.
2010-03-16
The U.S. Department of Energy's National Renewable Energy Laboratory collaborates with the solar industry to establish high quality solar and meteorological measurements. This Solar Resource and Meteorological Assessment Project (SOLRMAP) provides high quality measurements to support deployment of power projects in the United States. The no-funds-exchanged collaboration brings NREL solar resource assessment expertise together with industry needs for measurements. The end result is high quality data sets to support the financing, design, and monitoring of large scale solar power projects for industry in addition to research-quality data for NREL model development. NREL provides consultation for instrumentation and station deployment, along with instrument calibrations, data acquisition, quality assessment, data distribution, and summary reports. Industry participants provide equipment, infrastructure, and station maintenance.
Stoffel, T.; Andreas, A.
2010-04-26
The U.S. Department of Energy's National Renewable Energy Laboratory collaborates with the solar industry to establish high quality solar and meteorological measurements. This Solar Resource and Meteorological Assessment Project (SOLRMAP) provides high quality measurements to support deployment of power projects in the United States. The no-funds-exchanged collaboration brings NREL solar resource assessment expertise together with industry needs for measurements. The end result is high quality data sets to support the financing, design, and monitoring of large scale solar power projects for industry in addition to research-quality data for NREL model development. NREL provides consultation for instrumentation and station deployment, along with instrument calibrations, data acquisition, quality assessment, data distribution, and summary reports. Industry participants provide equipment, infrastructure, and station maintenance.
Wilcox, S.; Andreas, A.
2010-07-13
The U.S. Department of Energy's National Renewable Energy Laboratory collaborates with the solar industry to establish high quality solar and meteorological measurements. This Solar Resource and Meteorological Assessment Project (SOLRMAP) provides high quality measurements to support deployment of power projects in the United States. The no-funds-exchanged collaboration brings NREL solar resource assessment expertise together with industry needs for measurements. The end result is high quality data sets to support the financing, design, and monitoring of large scale solar power projects for industry in addition to research-quality data for NREL model development. NREL provides consultation for instrumentation and station deployment, along with instrument calibrations, data acquisition, quality assessment, data distribution, and summary reports. Industry participants provide equipment, infrastructure, and station maintenance.
Wilcox, S.; Andreas, A.
2012-11-03
The U.S. Department of Energy's National Renewable Energy Laboratory collaborates with the solar industry to establish high quality solar and meteorological measurements. This Solar Resource and Meteorological Assessment Project (SOLRMAP) provides high quality measurements to support deployment of power projects in the United States. The no-funds-exchanged collaboration brings NREL solar resource assessment expertise together with industry needs for measurements. The end result is high quality data sets to support the financing, design, and monitoring of large scale solar power projects for industry in addition to research-quality data for NREL model development. NREL provides consultation for instrumentation and station deployment, along with instrument calibrations, data acquisition, quality assessment, data distribution, and summary reports. Industry participants provide equipment, infrastructure, and station maintenance.
Solar Resource & Meteorological Assessment Project (SOLRMAP): Sun Spot Two; Swink, Colorado (Data)
Wilcox, S.; Andreas, A.
2010-11-10
The U.S. Department of Energy's National Renewable Energy Laboratory collaborates with the solar industry to establish high quality solar and meteorological measurements. This Solar Resource and Meteorological Assessment Project (SOLRMAP) provides high quality measurements to support deployment of power projects in the United States. The no-funds-exchanged collaboration brings NREL solar resource assessment expertise together with industry needs for measurements. The end result is high quality data sets to support the financing, design, and monitoring of large scale solar power projects for industry in addition to research-quality data for NREL model development. NREL provides consultation for instrumentation and station deployment, along with instrument calibrations, data acquisition, quality assessment, data distribution, and summary reports. Industry participants provide equipment, infrastructure, and station maintenance.
Wilcox, S.; Andreas, A.
2010-07-14
The U.S. Department of Energy's National Renewable Energy Laboratory collaborates with the solar industry to establish high quality solar and meteorological measurements. This Solar Resource and Meteorological Assessment Project (SOLRMAP) provides high quality measurements to support deployment of power projects in the United States. The no-funds-exchanged collaboration brings NREL solar resource assessment expertise together with industry needs for measurements. The end result is high quality data sets to support the financing, design, and monitoring of large scale solar power projects for industry in addition to research-quality data for NREL model development. NREL provides consultation for instrumentation and station deployment, along with instrument calibrations, data acquisition, quality assessment, data distribution, and summary reports. Industry participants provide equipment, infrastructure, and station maintenance.
Wilcox, S.; Andreas, A.
2009-07-22
The U.S. Department of Energy's National Renewable Energy Laboratory collaborates with the solar industry to establish high quality solar and meteorological measurements. This Solar Resource and Meteorological Assessment Project (SOLRMAP) provides high quality measurements to support deployment of power projects in the United States. The no-funds-exchanged collaboration brings NREL solar resource assessment expertise together with industry needs for measurements. The end result is high quality data sets to support the financing, design, and monitoring of large scale solar power projects for industry in addition to research-quality data for NREL model development. NREL provides consultation for instrumentation and station deployment, along with instrument calibrations, data acquisition, quality assessment, data distribution, and summary reports. Industry participants provide equipment, infrastructure, and station maintenance.
Wilcox, S.; Andreas, A.
2010-11-03
The U.S. Department of Energy's National Renewable Energy Laboratory collaborates with the solar industry to establish high quality solar and meteorological measurements. This Solar Resource and Meteorological Assessment Project (SOLRMAP) provides high quality measurements to support deployment of power projects in the United States. The no-funds-exchanged collaboration brings NREL solar resource assessment expertise together with industry needs for measurements. The end result is high quality data sets to support the financing, design, and monitoring of large scale solar power projects for industry in addition to research-quality data for NREL model development. NREL provides consultation for instrumentation and station deployment, along with instrument calibrations, data acquisition, quality assessment, data distribution, and summary reports. Industry participants provide equipment, infrastructure, and station maintenance.
High beam quality and high energy short-pulse laser with MOPA
NASA Astrophysics Data System (ADS)
Jin, Quanwei; Pang, Yu; Jiang, JianFeng; Tan, Liang; Cui, Lingling; Wei, Bin; Sun, Yinhong; Tang, Chun
2018-03-01
A high energy, high beam quality short-pulse diode-pumped Nd:YAG master oscillator power-amplifier (MOPA) laser with two amplifier stages is demonstrated. The two-rod birefringence compensation was used as beam quality controlling methods, which presents a short-pulse energy of 40 mJ with a beam quality value of M2 = 1.2 at a repetition rate of 400Hz. The MOPA system delivers a short-pulse energy of 712.5 mJ with a pulse width of 12.4 ns.The method of spherical aberration compensation is improved the beam quality, a M2 factor of 2.3 and an optical-to-optical efficiency of 27.7% is obtained at the maximum laser out power.The laser obtained 1.4J out energy with polarization integration.
Enhanced stability of magnetoelectric gyrators under high power conditions
NASA Astrophysics Data System (ADS)
Leung, Chung Ming; Zhuang, Xin; Gao, Min; Tang, Xiao; Xu, Junran; Li, Jiefang; Zhang, Jitao; Srinivasan, G.; Viehland, D.
2017-10-01
In this study, three different coil-based magnetoelectric (ME) gyrators of different geometries, including gyrators with high power output, have been designed and characterized. These included two magnetostrictive/piezoelectric/magnetostrictive (M-P-M) and one piezoelectric/magnetostrictive/piezoelectric (P-M-P) type ME gyrators, which consisted of nickel zinc ferrite (NZFO) and lead zirconate titanate (PZT) ceramic plates. Compared with M-P-M ME gyrators, the P-M-P ones exhibited a higher power efficiency (η) of 85% when operated at resonance under an optimal magnetic bias field (HBias) of 40 Oe at low power conditions. It retained a relatively high efficiency of η = 79% under a high input power density of 2.87 W/cm3. A low reduction in the magnetomechanical coupling and mechanical quality (k33,m and Qm) factors of the NZFO ferrite layer in the ME gyrator explains the resilience of the P-M-P type structure with increasing power drive. The findings open the possibility of using ME gyrators in high power applications.
Modelling and Simulation of Grid Connected SPV System with Active Power Filtering Features
NASA Astrophysics Data System (ADS)
Saroha, Jaipal; Pandove, Gitanjali; Singh, Mukhtiar
2017-09-01
In this paper, the detailed simulation studies for a grid connected solar photovoltaic system (SPV) have been presented. The power electronics devices like DC-DC boost converter and grid interfacing inverter are most important components of proposed system. Here, the DC-DC boost converter is controlled to extract maximum power out of SPV under different irradiation levels, while the grid interfacing inverter is utilized to evacuate the active power and feed it into grid at synchronized voltage and frequency. Moreover, the grid interfacing inverter is also controlled to sort out the issues related to power quality by compensating the reactive power and harmonics current component of nearby load at point of common coupling. Besides, detailed modeling of various component utilized in proposed system is also presented. Finally, extensive simulations have been performed under different irradiation levels with various kinds of load to validate the aforementioned claims. The overall system design and simulation have been performed by using Sim Power System toolbox available in the library of MATLAB.
DC Microgrids Scoping Study. Estimate of Technical and Economic Benefits
DOE Office of Scientific and Technical Information (OSTI.GOV)
Backhaus, Scott N.; Swift, Gregory William; Chatzivasileiadis, Spyridon
Microgrid demonstrations and deployments are expanding in US power systems and around the world. Although goals are specific to each site, these microgrids have demonstrated the ability to provide higher reliability and higher power quality than utility power systems and improved energy utilization. The vast majority of these microgrids are based on AC power transfer because this has been the traditionally dominant power delivery scheme. Independently, manufacturers, power system designers and researchers are demonstrating and deploying DC power distribution systems for applications where the end-use loads are natively DC, e.g., computers, solid-state lighting, and building networks. These early DC applicationsmore » may provide higher efficiency, added flexibility, reduced capital costs over their AC counterparts. Further, when onsite renewable generation, electric vehicles and storage systems are present, DC-based microgrids may offer additional benefits. Early successes from these efforts raises a question - can a combination of microgrid concepts and DC distribution systems provide added benefits beyond what has been achieved individually?« less
Pereira, Lucas A; Nimphius, Sophia; Kobal, Ronaldo; Kitamura, Katia; Turisco, Luiz A L; Orsi, Rita C; Cal Abad, César Cs; Loturco, Irineu
2018-02-22
The aims of this study were to (1) assess the relationship between selected speed-power related abilities (determined by 20-m sprint, unloaded countermovement and squat jumps [CMJ and SJ] and loaded jump squat [JS]) and performance in two distinct change of direction (COD) protocols (Zigzag and T-Test), and (2) determine the magnitude of difference between female and male Brazilian National Olympic Team handball athletes. Fifteen male and twenty-three female elite handball athletes volunteered to perform the following assessments: SJ and CMJ; Zigzag and T-Test; 20-m sprint with 5-, 10-, and 20-m splits, and mean propulsive power (MPP) in JS. Pearson product moment correlation (P< 0.05) was performed to determine the relationship between the COD tests (Zigzag and T-test) and speed-power measures (sprint, SJ, CMJ and JS). The differences between male and female performances were determined using the magnitude-based inference. Moderate to very large significant correlations were observed between both COD tests and the speed-power abilities. Further, male athletes demonstrated likely to almost certainly higher performances than female athletes in all assessed variables. The results of the current study suggest that different speed-power qualities are strongly correlated to the performance obtained in various COD assessments (r values varying from 0.38 to 0.84 and from 0.34 to 0.84 for correlations between speed and power tests with Zigzag and T-Test, respectively). However, the level of these associations can vary greatly, according to the mechanical demands of each respective COD task. Whilst COD tests may be difficult to implement during competitive seasons, due to the strong correlations presented herein, the regular use of vertical jump tests with these athletes seems to be an effective and applied alternative. Furthermore, it might be inferred that the proper development of loaded and unloaded jump abilities has potential for improving the physical qualities related to COD performance in handball athletes.
Spinning Reserve From Hotel Load Response: Initial Progress
DOE Office of Scientific and Technical Information (OSTI.GOV)
Kueck, John D; Kirby, Brendan J
2008-11-01
This project was motivated by the fundamental match between hotel space conditioning load response capability and power system contingency response needs. As power system costs rise and capacity is strained demand response can provide a significant system reliability benefit at a potentially attractive cost. At ORNL s suggestion, Digital Solutions Inc. adapted its hotel air conditioning control technology to supply power system spinning reserve. This energy saving technology is primarily designed to provide the hotel operator with the ability to control individual room temperature set-points based upon occupancy (25% to 50% energy savings based on an earlier study [Kirby andmore » Ally, 2002]). DSI added instantaneous local load shedding capability in response to power system frequency and centrally dispatched load shedding capability in response to power system operator command. The 162 room Music Road Hotel in Pigeon Forge Tennessee agreed to host the spinning reserve test. The Tennessee Valley Authority supplied real-time metering equipment in the form of an internet connected Dranetz-BMI power quality meter and monitoring expertise to record total hotel load during both normal operations and test results. The Sevier County Electric System installed the metering. Preliminary testing showed that hotel load can be curtailed by 22% to 37% depending on the outdoor temperature and the time of day. These results are prior to implementing control over the common area air conditioning loads. Testing was also not at times of highest system or hotel loading. Full response occurred in 12 to 60 seconds from when the system operator s command to shed load was issued. The load drop was very rapid, essentially as fast as the 2 second metering could detect, with all units responding essentially simultaneously. Load restoration was ramped back in over several minutes. The restoration ramp can be adjusted to the power system needs. Frequency response testing was not completed. Initial testing showed that the units respond very quickly. Problems with local power quality generated false low frequency signals which required testing to be stopped. This should not be a problem in actual operation since the frequency trip points will be staggered to generate a droop curve which mimics generator governor response. The actual trip frequencies will also be low enough to avoid power quality problems. The actual trip frequencies are too low to generate test events with sufficient regularity to complete testing in a reasonable amount of time. Frequency response testing will resume once the local power quality problem is fully understood and reasonable test frequency settings can be determined. Overall the preliminary testing was extremely successful. The hotel response capability matches the power system reliability need, being faster than generation response and inherently available when the power system is under the most stress (times of high system and hotel load). Periodic testing is scheduled throughout the winter and spring to characterize hotel response capability under a full range of conditions. More extensive testing will resume when summer outdoor temperatures are again high enough to fully test hotel response.« less
Duke, Trevor; Hwaihwanje, Ilomo; Kaupa, Magdalynn; Karubi, Jonah; Panauwe, Doreen; Sa'avu, Martin; Pulsan, Francis; Prasad, Peter; Maru, Freddy; Tenambo, Henry; Kwaramb, Ambrose; Neal, Eleanor; Graham, Hamish; Izadnegahdar, Rasa
2017-06-01
Pneumonia is the largest cause of child deaths in Papua New Guinea (PNG), and hypoxaemia is the major complication causing death in childhood pneumonia, and hypoxaemia is a major factor in deaths from many other common conditions, including bronchiolitis, asthma, sepsis, malaria, trauma, perinatal problems, and obstetric emergencies. A reliable source of oxygen therapy can reduce mortality from pneumonia by up to 35%. However, in low and middle income countries throughout the world, improved oxygen systems have not been implemented at large scale in remote, difficult to access health care settings, and oxygen is often unavailable at smaller rural hospitals or district health centers which serve as the first point of referral for childhood illnesses. These hospitals are hampered by lack of reliable power, staff training and other basic services. We report the methodology of a large implementation effectiveness trial involving sustainable and renewable oxygen and power systems in 36 health facilities in remote rural areas of PNG. The methodology is a before-and after evaluation involving continuous quality improvement, and a health systems approach. We describe this model of implementation as the considerations and steps involved have wider implications in health systems in other countries. The implementation steps include: defining the criteria for where such an intervention is appropriate, assessment of power supplies and power requirements, the optimal design of a solar power system, specifications for oxygen concentrators and other oxygen equipment that will function in remote environments, installation logistics in remote settings, the role of oxygen analyzers in monitoring oxygen concentrator performance, the engineering capacity required to sustain a program at scale, clinical guidelines and training on oxygen equipment and the treatment of children with severe respiratory infection and other critical illnesses, program costs, and measurement of processes and outcomes to support continuous quality improvement. This study will evaluate the feasibility and sustainability issues in improving oxygen systems and providing reliable power on a large scale in remote rural settings in PNG, and the impact of this on child mortality from pneumonia over 3 years post-intervention. Taking a continuous quality improvement approach can be transformational for remote health services.
Kubo, N
1995-04-01
To improve the quality of single-photon emission computed tomographic (SPECT) images, a restoration filter has been developed. This filter was designed according to practical "least squares filter" theory. It is necessary to know the object power spectrum and the noise power spectrum. The power spectrum is estimated from the power spectrum of a projection, when the high-frequency power spectrum of a projection is adequately approximated as a polynomial exponential expression. A study of the restoration with the filter based on a projection power spectrum was conducted, and compared with that of the "Butterworth" filtering method (cut-off frequency of 0.15 cycles/pixel), and "Wiener" filtering (signal-to-noise power spectrum ratio was a constant). Normalized mean-squared errors (NMSE) of the phantom, two line sources located in a 99mTc filled cylinder, were used. NMSE of the "Butterworth" filter, "Wiener" filter, and filtering based on a power spectrum were 0.77, 0.83, and 0.76 respectively. Clinically, brain SPECT images utilizing this new restoration filter improved the contrast. Thus, this filter may be useful in diagnosis of SPECT images.
Substation Reactive Power Regulation Strategy
NASA Astrophysics Data System (ADS)
Zhang, Junfeng; Zhang, Chunwang; Ma, Daqing
2018-01-01
With the increasing requirements on the power supply quality and reliability of distribution network, voltage and reactive power regulation of substations has become one of the indispensable ways to ensure voltage quality and reactive power balance and to improve the economy and reliability of distribution network. Therefore, it is a general concern of the current power workers and operators that what kind of flexible and effective control method should be used to adjust the on-load tap-changer (OLTC) transformer and shunt compensation capacitor in a substation to achieve reactive power balance in situ, improve voltage pass rate, increase power factor and reduce active power loss. In this paper, based on the traditional nine-zone diagram and combining with the characteristics of substation, a fuzzy variable-center nine-zone diagram control method is proposed and used to make a comprehensive regulation of substation voltage and reactive power. Through the calculation and simulation of the example, this method is proved to have satisfactorily reconciled the contradiction between reactive power and voltage in real-time control and achieved the basic goal of real-time control of the substation, providing a reference value to the practical application of the substation real-time control method.
2.1 μm high-power laser diode beam combining(Conference Presentation)
NASA Astrophysics Data System (ADS)
Berrou, Antoine P. C.; Elder, Ian F.; Lamb, Robert A.; Esser, M. J. Daniel
2016-10-01
Laser power and brightness scaling, in "eye safe" atmospheric transmission windows, is driving laser system research and development. High power lasers with good beam quality, at wavelength around 2.1 µm, are necessary for optical countermeasure applications. For such applications, focusing on efficiency and compactness of the system is mandatory. In order to cope with these requirements, one must consider the use of laser diodes which emit directly in the desired spectral region. The challenge for these diodes is to maintain a good beam quality factor as the output power increases. 2 µm diodes with excellent beam quality in both axes are available with output powers of 100 mW. Therefore, in order to reach multi-watt of average output power, broad-area single emitters and beam combining becomes relevant. Different solutions have been implemented in the 1.9 to 2 µm wavelength range, one of which is to stack multiple emitter bars reaching more than one hundred watt, while another is a fibre coupled diode module. The beam propagation factor of these systems is too high for long atmospheric propagation applications. Here we describe preliminary results on non-coherent beam combining of 2.1 µm high power Fabry-Perot GaSb laser diodes supplied by Brolis Semiconductors Ltd. First we evaluated single mode diodes (143 mW) with good beam quality (M2 < 1.5 for slow axis and < 1.1 for fast axis). Then we characterized broad-area single emitter diodes (808 mW) with an electrical-to-optical efficiency of 19 %. The emitter width was 90 µm with a cavity length of 1.5 mm. In our experiments we found that the slow axis multimode output beam consisted of two symmetric lobes with a total full width at half maximum (FWHM) divergence angle of 25 degrees, corresponding to a calculated beam quality factor of M2 = 25. The fast axis divergence was specified to be 44 degrees, with an expected beam quality factor close to the diffraction limit, which informed our selection of collimation lenses used in the experiment. We evaluated two broadband (1.8 - 3 µm) AR coated Geltech aspheric lenses with focal lengths of 1.87 mm and 4 mm, with numerical apertures of 0.85 and 0.56, respectively, as an initial collimation lens, followed by an additional cylindrical lens of focal length 100 mm for fully collimating the slow axis. Using D-shaped gold-coated mirrors, multiple single emitter beams are stacked in the fast axis direction with the objective that the combined beam has a beam propagation factor in the stacking direction close to the beam propagation factor of the slow axis of a single emitter, e.g. M2 of 20 to 25 in both axes. We further found that the output beam of a single emitter is highly linearly polarized along the slow axis, making it feasible to implement polarization beam combining techniques to increase the beam power by a factor two while maintaining the same beam quality. Along with full beam characterization, a power scaling strategy towards a multi-watt output power beam combining laser system will be presented.
18 CFR 12.40 - Quality control programs.
Code of Federal Regulations, 2011 CFR
2011-04-01
... 18 Conservation of Power and Water Resources 1 2011-04-01 2011-04-01 false Quality control... PROJECT WORKS Other Responsibilities of Applicant or Licensee § 12.40 Quality control programs. (a... meeting any requirements or standards set by the Regional Engineer. If a quality control program is...
18 CFR 12.40 - Quality control programs.
Code of Federal Regulations, 2010 CFR
2010-04-01
... 18 Conservation of Power and Water Resources 1 2010-04-01 2010-04-01 false Quality control... PROJECT WORKS Other Responsibilities of Applicant or Licensee § 12.40 Quality control programs. (a... meeting any requirements or standards set by the Regional Engineer. If a quality control program is...
Training Quality: Before and after Winning the Deming Prize.
ERIC Educational Resources Information Center
Magennis, Jo P.
1995-01-01
Describes the Quality Improvement Program developed by Florida Power and Light's Nuclear Training organization that was awarded the Deming Application Prize for quality control. Training quality, team activities, training's role in business planning, customer involvement and evaluation, and continuous improvement of training are discussed. (LRW)
NASA Astrophysics Data System (ADS)
Chun-Lin, Louis Chang
Rare-earth-doped fiber lasers and amplifiers are relatively easy to efficiently produce a stable and high quality laser beam in a compact, robust, and alignment-free configuration. Recently, high power fiber laser systems have facilitated wide spread applications in academics, industries, and militaries in replacement of bulk solid-state laser systems. The master oscillator power amplifier (MOPA) composed of a highly-controlled seed, high-gain preamplifiers, and high-efficiency power amplifiers are typically utilized to scale up the pulse energy, peak power, or average power. Furthermore, a direct-current-modulated nanosecond diode laser in single transverse mode can simply provide a compact and highly-controlled seed to result in the flexible output parameters, such as repetition rate, pulse duration, and even temporal pulse shape. However, when scaling up the peak power for high intensity applications, such a versatile diode-seeded nanosecond MOPA laser system using rare-earth-doped fibers is unable to completely save its own advantages compared to bulk laser systems. Without a strong seeding among the amplifiers, the guided amplified spontaneous amplification is easy to become dominant during the amplification, leading to the harmful self-lasing or pulsing effects, and the difficulty of the quantitative numerical comparison. In this dissertation, we study a high-efficiency and intense nanosecond ytterbium fiber MOPA system with good beam quality and stability for high intensity applications. The all-PM-fiber structure is achieved with the output extinction ratio of >12 dB by optimizing the interconnection of high power optical fibers. The diode-seeded MOPA configuration without parasitic stimulated amplification (PAS) is implemented using the double-pass scheme to extract energy efficiently for scaling peak power. The broadband PAS was studied experimentally, which matches well with our numerical simulation. The 1064-nm nanosecond seed was a direct-current-modulated Fabry-Perot diode laser associated with a weak and pulsed noise spanning from 1045 to 1063 nm. Even though the contribution of input noise pulse is only <5%, it becomes a significant transient spike during amplification. The blue-shifted pulsed noise may be caused by band filling effect for quantum-well seed laser driven by high peak current. The study helps the development of adaptive pulse shaping for scaling peak power or energy at high efficiency. On the other hand, the broadband spike with a 3-dB bandwidth of 8.8 nm can support pulses to seed the amplifier for sub-nanosecond giant pulse generation. Because of the very weak seed laser, the design of high-gain preamplifier becomes critical. The utilization of single-mode core-pumped fiber preamplifier can not only improve the mode contrast without fiber coiling effect but also significantly suppress the fiber nonlinearity. The double-pass scheme was therefore studied both numerically and experimentally to improve energy extraction efficiency for the lack of attainable seed and core-pumped power. As a result, a record-high peak power of > 30 kW and energy of > 0.23 mJ was successfully achieved to the best of our knowledge from the output of clad-pumped power amplifier with a beam quality of M2 ˜1.1 in a diode-seeded 15-microm-core fiber MOPA system. After the power amplifier, the MOPA conversion efficiency can be dramatically improved to >56% for an energy gain of >63 dB at a moderate repetition rate of 20 kHz with a beam quality of M 2 <1.5. The output energy of >1.1 mJ with a pulse duration of ˜6.1 ns can result in a peak power up to >116 kW which is limited by fiber fuse in long-term operation. Such a condition able to generate the on-target laser intensity of > 60 GW/cm2 for applications is qualified to preliminarily create a laser-plasma light source. Moreover, the related simulation results also reveal the double-passed power amplifier can further simplify MOPA. Such an intense clad-pumped power amplifier can further become a nonlinear fiber amplifier in all-normal dispersion instead of a nonlinear passive fiber. The combination of laser amplification and nonlinear conversion together can therefore overcome the significant pump depletion during the propagation along the passive fiber for power scaling. As a result, an intense spectrum spanning from 980 to 1600 nm as a high-power nanosecond supercontinuum source can be successfully generated with a conversion efficiency of >65% and a record-high peak power of >116 kW to the best of our knowledge. Because of MOPA structure, the influence of input parameters of nonlinear fiber amplifier on supercontinuum parameters can also be studied. The onset and interplay of fiber nonlinearities can be revealed stage by stage. Such an unique and linearly-polarized light source composed of an intense pump and broad sideband seed is beneficial for efficiently driving the broadband tunable optical parametric amplification free from the bulkiness and timing jitter. Keywords: High power fiber laser and amplifier, ytterbium fiber, master oscillator power amplification, parasitic stimulated amplification, multi-pass fiber amplification, peak power/pulse energy scaling, fiber nonlinear optics, supercontinuum generation.
Water turbidity optical meter using optical fiber array for topographical distribution analysis
NASA Astrophysics Data System (ADS)
Mutter, Kussay Nugamesh; Mat Jafri, Mohd Zubir; Yeoh, Stephenie
2017-06-01
This work is presenting an analysis study for using optical fiber array as turbidity meter and topographical distribution. Although many studies have been figure out of utilizing optical fibers as sensors for turbidity measurements, still the topographical map of suspended particles in water as rare as expected among all of works in literatures in this scope. The effect of suspended particles are highly affect the water quality which varies according to the source of these particles. A two dimensional array of optical fibers in a 1 litter rectangular plastic container with 2 cm cladding off sensing portion prepared to point out 632.8 nm laser power at each fiber location at the container center. The overall output map of the optical power were found in an inhomogeneous distribution such that the top to down layers of a present water sample show different magnitudes. Each sample prepared by mixing a distilled water with large grains sand, small grains sand, glucose and salt. All with different amount of concentration which measured by refractometer and turbidity meter. The measurements were done in different times i.e. from 10 min to 60 min. This is to let the heavy particles to move down and accumulate at the bottom of the container. The results were as expected which had a gradually topographical map from low power at top layers into high power at bottom layers. There are many applications can be implemented of this study such as transport vehicles fuel meter, to measure the purity of tanks, and monitoring the fluids quality in pipes.
QPO detection in superluminal black hole GRS 1915+105
NASA Astrophysics Data System (ADS)
Bhulla, Yashpal; Jaaffrey, S. N. A.
2018-05-01
We report on the first superluminal Black Hole GRS 1915+105 observed by the Rossi X-ray Timing Explorer - Proportion Counter Array (RXTE/PCA). We detect the Quasi Periodic Oscillations (QPOs) in the Power Density Spectrum (PDS) of source which have luminosity very near to Eddington limit and long variability in X-ray light curve. In power density spectrum, we deal with the study of highly variability amplitude, time evolution of the characteristic timescale, Quality Factor and Full Width at Half Maximum (FWHM). We find significant QPOs in 15 different observation IDs with frequency around 67 Hz although quality factor nearly 20 but in two IDs frequency is found just double. Typical fractional rms for GRS 1915+105 is dominating the hard band increasing steeply with energy more than 13% at 20-40 keV band.
NASA Astrophysics Data System (ADS)
Zhang, Zongyang; Liu, Xiansong; Feng, Shuangjiu; Rehman, Khalid Mehmood Ur
2018-03-01
In this study, the melt spinning method was used to develop Fe80.5Si7.5B6Nb5Cu amorphous ribbons in the first step. Then, the Fe80.5Si7.5B6Nb5Cu amorphous-nanocrystalline core with a compact microstructure was obtained by multiple processes. The main properties of the magnetic powder core, such as micromorphology, thermal behavior, permeability, power loss and quality factor, have been analyzed. The obtained results show that an Fe80.5Si7.5B6Nb5Cu amorphous-nanocrystalline duplex core has high permeability (54.8-57), is relatively stable at different frequencies and magnetic fields, and the maximum power loss is only 313 W/kg; furthermore, it has a good quality factor.
Yin, Qiwei; Lu, Huadong; Su, Jing; Peng, Kunchi
2016-05-01
The thermal lens effect of terbium gallium garnet (TGG) crystal in a high power single-frequency laser severely limits the output power and the beam quality of the laser. By inserting a potassium dideuterium phosphate (DKDP) slice with negative thermo-optical coefficient into the laser resonator, the harmful influence of the thermal lens effect of the TGG crystal can be effectively mitigated. Using this method, the stable range of the laser is broadened, the bistability phenomenon of the laser during the process of changing the pump power is completely eliminated, the highest output power of an all-solid-state continuous-wave intracavity-frequency-doubling single-frequency laser at 532 nm is enhanced to 30.2 W, and the beam quality of the laser is significantly improved.
Asthma in the vicinity of power stations: II. Outdoor air quality and symptoms
DOE Office of Scientific and Technical Information (OSTI.GOV)
Henry, R.L.; Bridgman, H.A.; Wlodarczyk, J.
1991-01-01
To assess longitudinally the effect of living in the vicinity of coal-fired power stations on children with asthma, 99 schoolchildren with a history of wheezing in the previous 12 months were studied for 1 year, using daily diaries and measurements of air quality. The children had been identified in a cross-sectional survey of two coastal areas: Lake Munmorah (LM), within 5 km of two power stations, and Nelson Bay (NB), free from major industry. Daily air quality (sulphur dioxide (SO2) and nitrogen oxides (NOx)), respiratory symptoms, and treatment for asthma were recorded throughout the year. Measurements of SO2 and NOxmore » at LM were well within recommended guidelines although they were several times higher than at NB: maximum daily levels in SO2 (micrograms/m3) were 26 at LM, 11 at NB (standard, 365); yearly average SO2 was 2 at LM, 0.3 at NB (standard, 60); yearly average NOx (micrograms/m3) was 2 at LM, 0.4 at NB (standard, 94). Marked weekly fluctuations occurred in the prevalence of cough, wheezing, and breathlessness, without any substantial differences between LM and NB. Overall, the prevalence of symptoms was low (10% for wheezing, 20% for any symptom). Whether the daily SO2 and NOx levels affected the occurrence of respiratory symptoms was investigated in children at LM using a logistic regression (Korn and Whittemore technique). For these children as a group, air quality measurements were not associated with the occurrence of symptoms.« less
OMI air-quality monitoring over the Middle East
NASA Astrophysics Data System (ADS)
Barkley, Michael P.; González Abad, Gonzalo; Kurosu, Thomas P.; Spurr, Robert; Torbatian, Sara; Lerot, Christophe
2017-04-01
Using Ozone Monitoring Instrument (OMI) trace gas vertical column observations of nitrogen dioxide (NO2), formaldehyde (HCHO), sulfur dioxide (SO2), and glyoxal (CHOCHO), we have conducted a robust and detailed time series analysis to assess changes in local air quality for over 1000 locations (focussing on urban, oil refinery, oil port, and power plant targets) over the Middle East for 2005-2014. Apart from NO2, which is highest over urban locations, average tropospheric column levels of these trace gases are highest over oil ports and refineries. The highest average pollution levels over urban settlements are typically in Bahrain, Kuwait, Qatar, and the United Arab Emirates. We detect 278 statistically significant and real linear NO2 trends in total. Over urban areas NO2 increased by up to 12 % yr-1, with only two locations showing a decreasing trend. Over oil refineries, oil ports, and power plants, NO2 increased by about 2-9 % yr-1. For HCHO, 70 significant and real trends were detected, with HCHO increasing by 2-7 % yr-1 over urban settlements and power plants and by about 2-4 % yr-1 over refineries and oil ports. Very few SO2 trends were detected, which varied in direction and magnitude (23 increasing and 9 decreasing). Apart from two locations where CHOCHO is decreasing, we find that glyoxal tropospheric column levels are not changing over the Middle East. Hence, for many locations in the Middle East, OMI observes a degradation in air quality over 2005-2014. This study therefore demonstrates the capability of OMI to generate long-term air-quality monitoring at local scales over this region.
NASA Astrophysics Data System (ADS)
Rodriguez, M. A.; Carreras-Sospedra, M.; Medrano, M.; Brouwer, J.; Samuelsen, G. S.; Dabdub, D.
Distributed generation (DG) is generally defined as the operation of many small stationary power generators throughout an urban air basin. Although DG has the potential to supply a significant portion of the increased power demands in California and the rest of the United States, it may lead to increased levels of in-basin pollutants and adversely impact urban air quality. This study focuses on two main objectives: (1) the systematic characterization of DG installation in urban air basins, and (2) the simulation of potential air quality impacts using a state-of-the-art three-dimensional computational model. A general and systematic approach is devised to construct five realistic and 21 spanning scenarios of DG implementation in the South Coast Air Basin (SoCAB) of California. Realistic scenarios reflect an anticipated level of DG deployment in the SoCAB by the year 2010. Spanning scenarios are developed to determine the potential impacts of unexpected outcomes. Realistic implementations of DG in the SoCAB result in small differences in ozone and particulate matter concentrations in the basin compared to the baseline simulations. The baseline accounts for population increase, but does not consider any future emissions control measures. Model results for spanning implementations with extra high DG market penetration show that domain-wide ozone peak concentrations increase significantly. Also, air quality impacts of spanning implementations when DG operate during a 6-h period are larger than when the same amount of emissions are introduced during a 24-h period.
An improved global wind resource estimate for integrated assessment models
Eurek, Kelly; Sullivan, Patrick; Gleason, Michael; ...
2017-11-25
This study summarizes initial steps to improving the robustness and accuracy of global renewable resource and techno-economic assessments for use in integrated assessment models. We outline a method to construct country-level wind resource supply curves, delineated by resource quality and other parameters. Using mesoscale reanalysis data, we generate estimates for wind quality, both terrestrial and offshore, across the globe. Because not all land or water area is suitable for development, appropriate database layers provide exclusions to reduce the total resource to its technical potential. We expand upon estimates from related studies by: using a globally consistent data source of uniquelymore » detailed wind speed characterizations; assuming a non-constant coefficient of performance for adjusting power curves for altitude; categorizing the distance from resource sites to the electric power grid; and characterizing offshore exclusions on the basis of sea ice concentrations. The product, then, is technical potential by country, classified by resource quality as determined by net capacity factor. Additional classifications dimensions are available, including distance to transmission networks for terrestrial wind and distance to shore and water depth for offshore. We estimate the total global wind generation potential of 560 PWh for terrestrial wind with 90% of resource classified as low-to-mid quality, and 315 PWh for offshore wind with 67% classified as mid-to-high quality. These estimates are based on 3.5 MW composite wind turbines with 90 m hub heights, 0.95 availability, 90% array efficiency, and 5 MW/km 2 deployment density in non-excluded areas. We compare the underlying technical assumption and results with other global assessments.« less
An improved global wind resource estimate for integrated assessment models
DOE Office of Scientific and Technical Information (OSTI.GOV)
Eurek, Kelly; Sullivan, Patrick; Gleason, Michael
This study summarizes initial steps to improving the robustness and accuracy of global renewable resource and techno-economic assessments for use in integrated assessment models. We outline a method to construct country-level wind resource supply curves, delineated by resource quality and other parameters. Using mesoscale reanalysis data, we generate estimates for wind quality, both terrestrial and offshore, across the globe. Because not all land or water area is suitable for development, appropriate database layers provide exclusions to reduce the total resource to its technical potential. We expand upon estimates from related studies by: using a globally consistent data source of uniquelymore » detailed wind speed characterizations; assuming a non-constant coefficient of performance for adjusting power curves for altitude; categorizing the distance from resource sites to the electric power grid; and characterizing offshore exclusions on the basis of sea ice concentrations. The product, then, is technical potential by country, classified by resource quality as determined by net capacity factor. Additional classifications dimensions are available, including distance to transmission networks for terrestrial wind and distance to shore and water depth for offshore. We estimate the total global wind generation potential of 560 PWh for terrestrial wind with 90% of resource classified as low-to-mid quality, and 315 PWh for offshore wind with 67% classified as mid-to-high quality. These estimates are based on 3.5 MW composite wind turbines with 90 m hub heights, 0.95 availability, 90% array efficiency, and 5 MW/km 2 deployment density in non-excluded areas. We compare the underlying technical assumption and results with other global assessments.« less
Study of small civil turbofan engines applicable to military trainer airplanes
NASA Technical Reports Server (NTRS)
Heldenbrand, R. W.; Merrill, G. L.; Burnett, G. A.
1975-01-01
Small turbofan engine design concepts were applied to military trainer airplanes to establish the potential for commonality between civil and military engines. Several trainer configurations were defined and studied. A ""best'' engine was defined for the trainer mission, and sensitivity analyses were performed to determine the effects on airplane size and efficiency of wing loading, power loading, configuration, aerodynamic quality, and engine quality. It is concluded that a small civil aircraft is applicable to military trainer airplanes. Aircraft designed with these engines are smaller, less costly, and more efficient than existing trainer aircraft.
Nature of air pollution, emission sources, and management in the Indian cities
NASA Astrophysics Data System (ADS)
Guttikunda, Sarath K.; Goel, Rahul; Pant, Pallavi
2014-10-01
The global burden of disease study estimated 695,000 premature deaths in 2010 due to continued exposure to outdoor particulate matter and ozone pollution for India. By 2030, the expected growth in many of the sectors (industries, residential, transportation, power generation, and construction) will result in an increase in pollution related health impacts for most cities. The available information on urban air pollution, their sources, and the potential of various interventions to control pollution, should help us propose a cleaner path to 2030. In this paper, we present an overview of the emission sources and control options for better air quality in Indian cities, with a particular focus on interventions like urban public transportation facilities; travel demand management; emission regulations for power plants; clean technology for brick kilns; management of road dust; and waste management to control open waste burning. Also included is a broader discussion on key institutional measures, like public awareness and scientific studies, necessary for building an effective air quality management plan in Indian cities.
Comparative study on the freeze stability of yeast and chemical leavened steamed bread dough.
Wang, Pei; Yang, Runqiang; Gu, Zhenxin; Xu, Xueming; Jin, Zhengyu
2017-04-15
The present study comparatively evaluated the evolution of yeast and chemical leavened steamed bread dough (YLD/CLD) quality during freeze/thaw (FT) cycles. The steamed bread quality of CLD was more freeze-stable than that of the YLD after 3 FT cycles. Decreased yeast viability contributed to the loss of gassing power in YLD while no significant differences were observed for CLD during FT cycles. However, faster gas release rate in frozen CLD indicated gas retention loss due to the distortion of gluten network. Glutenin macropolymers (GMP) depolymerization via breakage of inter-chain disulfide (SS) bonds and conversions of α-helix and β-turn to β-sheet structures were the main indicators of gluten deterioration. Gluten network was more vulnerable in frozen YLD, resulting in detectable loss of viscoelasticity. The results suggested that supplement of chemical leavener contributed to a more freeze-tolerant gluten network besides its stable gassing power. Copyright © 2016 Elsevier Ltd. All rights reserved.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Davis, Lynn; Arquit Niederberger, Anne
Abstract— Lighting systems have the ability to transform the economic and educational infrastructure of disadvantaged communities, and eradicating “light poverty” has become one of the primary goals of the International Year of Light 2015. Solid-state lighting (SSL) technology, based on light-emitting diode (LED) light sources, has emerged as the next generation of lighting technology, with a current global market penetration of roughly 5%. This paper will report on recent research on understanding SSL lighting system reliability (failure modes, environmental stressors, electrical power quality); discuss the implications of SSL technology reliability for providing lighting services; and suggest practical approaches to ensuremore » SSL reliability to benefit humanity. Among the key findings from this work is that LED sources can be extremely reliable, withstanding a broad range of environmental stresses without failure. Nonetheless, SSL lighting systems can have a negative impact on electrical power reliability, as well as on the affordability of lighting services, without attention to the quality of the accompanying power infrastructure. It is therefore critical to ensure that the performance of the power supply electronics used in lighting systems is matched to the quality of the power source, when evaluating energy efficient lighting choices.« less
Power quality considerations for nuclear spectroscopy applications: Grounding
NASA Astrophysics Data System (ADS)
García-Hernández, J. M.; Ramírez-Jiménez, F. J.; Mondragón-Contreras, L.; López-Callejas, R.; Torres-Bribiesca, M. A.; Peña-Eguiluz, R.
2013-11-01
Traditionally the electrical installations are designed for supplying power and to assure the personnel safety. In nuclear analysis laboratories, additional issues about grounding also must be considered for proper operation of high resolution nuclear spectroscopy systems. This paper shows the traditional ways of grounding nuclear spectroscopy systems and through different scenarios, it shows the effects on the more sensitive parameter of these systems: the energy resolution, it also proposes the constant monitoring of a power quality parameter as a way to preserve or to improve the resolution of the systems, avoiding the influence of excessive extrinsic noise.
HIV, self-transcendence, and quality of life.
Mellors, M P; Riley, T A; Erlen, J A
1997-01-01
Self-transcendence is a developmental characteristic that expands one's boundaries of the self to take on broader life perspectives, activities, and purposes that help one discover or make meaning of one's life. However, no quantitative studies were found in the research literature that focused on self-transcendence or on the relationship between self-transcendence and quality of life in people infected with HIV. To examine these variables in this population, 46 HIV-positive subjects completed Reed's Self-Transcendence Scale and Ferrans and Powers' Quality of Life Index. The results demonstrated that overall self-transcendence for this sample was relatively high; quality of life was higher than that reported in previous research; and there were some significant group differences among the three HIV clinical categories.
Multi-Fresnel lenses pumping approach for improving high-power Nd:YAG solar laser beam quality.
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.
High Power Laser Welding. [of stainless steel and titanium alloy structures
NASA Technical Reports Server (NTRS)
Banas, C. M.
1972-01-01
A review of recent developments in high power, carbon dixoide laser welding is presented. Deep penetration welding in stainless steel to 0.5-in. thick, high speed welding in thin gage rimmed steel and gas shielded welding in Ti-6Al-4V alloy are described. The effects of laser power, power density, focusing optics, gas-shielding techniques, material properties and weld speed on weld quality and penetration are discussed. It is shown that laser welding performance in thin materials is comparable to that of electron beams. It is further shown that high quality welds, as evidenced by NDT, mechanical and metal-lographic tests, can be achieved. The potential of the laser for industrial welding applications is indicated.
High pumping-power fiber combiner for double-cladding fiber lasers and amplifiers
NASA Astrophysics Data System (ADS)
Zheng, Jinkun; Zhao, Wei; Zhao, Baoyin; Li, Zhe; Chang, Chang; Li, Gang; Gao, Qi; Ju, Pei; Gao, Wei; She, Shengfei; Wu, Peng; Hou, Chaoqi; Li, Weinan
2018-03-01
A high pumping-power fiber combiner for backward pumping configurations is fabricated and demonstrated by manufacturing process refinement. The pump power handling capability of every pump fiber can extend to 600 W, corresponding to the average pump coupling efficiency of 94.83%. Totally, 2.67-kW output power with the beam quality factor M2 of 1.41 was obtained, using this combiner in the fiber amplifier experimental setup. In addition, the temperature of the splicing region was less than 50.0°C in the designed combiner under the action of circulating cooling water. The experimental results prove that the designed combiner is a promising integrated all-fiber device for multikilowatt continuous-wave fiber laser with excellent beam quality.
Educational Auditing and Quality Assurance. Occasional Paper No. 4.
ERIC Educational Resources Information Center
Conner, James E.; Lessinger, Leon M.
This paper considers how to respond to new requirements for adequate disclosure of the schools' performance to the public. It proposes the use of three powerful constructs--quality control, quality assurance, and an independent educational accomplishment audit (IEAA). The essential elements of quality control are agreeing on and specifying desired…
Quality Assurance--Best Practices for Assessing Online Programs
ERIC Educational Resources Information Center
Wang, Qi
2006-01-01
Educators have long sought to define quality in education. With the proliferation of distance education and online learning powered by the Internet, the tasks required to assess the quality of online programs become even more challenging. To assist educators and institutions in search of quality assurance methods to continuously improve their…
NASA Astrophysics Data System (ADS)
Gupta, Amit; Shaina, Nagpal
2017-08-01
Intersymbol interference and attenuation of signal are two major parameters affecting the quality of transmission in Free Space Optical (FSO) Communication link. In this paper, the impact of these parameters on FSO communication link is analysed for delivering high-quality data transmission. The performance of the link is investigated under the influence of amplifier in the link. The performance parameters of the link like minimum bit error rate, received signal power and Quality factor are examined by employing erbium-doped fibre amplifier in the link. The effects of amplifier are visualized with the amount of received power. Further, the link is simulated for moderate weather conditions at various attenuation levels on transmitted signal. Finally, the designed link is analysed in adverse weather conditions by using high-power laser source for optimum performance.
Erickson, Larry E; Jennings, Merrisa
2017-01-01
The Paris Agreement on Climate Change has the potential to improve air quality and human health by encouraging the electrification of transportation and a transition from coal to sustainable energy. There will be human health benefits from reducing combustion emissions in all parts of the world. Solar powered charging infrastructure for electric vehicles adds renewable energy to generate electricity, shaded parking, and a needed charging infrastructure for electric vehicles that will reduce range anxiety. The costs of wind power, solar panels, and batteries are falling because of technological progress, magnitude of commercial activity, production experience, and competition associated with new trillion dollar markets. These energy and transportation transitions can have a very positive impact on health. The energy, transportation, air quality, climate change, health nexus may benefit from additional progress in developing solar powered charging infrastructure.
Adhesive quality inspection of wind rotor blades using thermography
NASA Astrophysics Data System (ADS)
Li, Xiaoli; Sun, Jiangang; Shen, Jingling; Wang, Xun; Zhang, Cunlin; Zhao, Yuejin
2018-04-01
Wind power is playing an increasingly important role in ensuring electrical safety for human beings. Because wind rotor blades are getting larger and larger in order to harvest wind energy more efficiently, there is a growing demand for nondestructive testing. Due to the glue structure of rotor blades, adhesive quality evaluation is needed. In this study, three adhesive samples with a wall thickness of 13mm, 28mm or 31mm were each designed with a different adhesive situation. The transmission thermography was applied to inspect the samples. The results illustrate that this method is effective to inspect adhesive quality of wind rotor blades.
Experience with the lathe cut Bausch & Lomb Soflens: Part II--Power and optics study.
Weissman, B A; Levinson, A
1978-04-01
Ten familiar spin cast and ten lathe cut Bausch & Lomb SOFLENS contact lenses were measured as to their power on a lensometer and on an eye. Both quality of the optics and quantitative measurements were considered. Lens flexure and the presence of a fluid lens between the posterior surface of the contact lens and the anterior cornea is indicated for both lenses to explain differences between power of the lens in air and on the eye. The spin cast lens design appears to create a quantitatively larger fluid lens, and one which will add positive optical power to the lens/eye system. Either from this and/or additional factors, the lathe cut lens appears to give improved optical performance both in air and on the eye.
ERIC Educational Resources Information Center
Perry, Phyllis J.
Fiction is a powerful tool that can motivate students to learn. This book is designed to assist elementary teachers in planning integrated units of study based on quality fiction titles about U.S. history. These titles build interest, illuminate specific eras, and lead students to related nonfiction titles. Organized in sections that cover…
The English in Public Elementary Schools Program of a Mexican State: A Critical, Exploratory Study
ERIC Educational Resources Information Center
Perales Escudero, Moises Damian; Reyes Cruz, Maria del Rosario; Loyo, Griselda Murrieta
2012-01-01
The quality of English-as-a-foreign-language (EFL) instruction in elementary schools worldwide is an issue of concern for language policy and planning (LPP) scholars, as are examinations of power and ideologies operating in policy creation and implementation. This critical, exploratory study blends these two strands of inquiry by examining…
ERIC Educational Resources Information Center
Murphy, Kerri Anne
2010-01-01
This study explored the relationship between community college students' working lives and student engagement. Student engagement has been used as a proxy for student persistence based on its strong association with student persistence and its powerful negative association with school drop-out. Work has been studied extensively as related to…
Universities Scale Like Cities
van Raan, Anthony F. J.
2013-01-01
Recent studies of urban scaling show that important socioeconomic city characteristics such as wealth and innovation capacity exhibit a nonlinear, particularly a power law scaling with population size. These nonlinear effects are common to all cities, with similar power law exponents. These findings mean that the larger the city, the more disproportionally they are places of wealth and innovation. Local properties of cities cause a deviation from the expected behavior as predicted by the power law scaling. In this paper we demonstrate that universities show a similar behavior as cities in the distribution of the ‘gross university income’ in terms of total number of citations over ‘size’ in terms of total number of publications. Moreover, the power law exponents for university scaling are comparable to those for urban scaling. We find that deviations from the expected behavior can indeed be explained by specific local properties of universities, particularly the field-specific composition of a university, and its quality in terms of field-normalized citation impact. By studying both the set of the 500 largest universities worldwide and a specific subset of these 500 universities -the top-100 European universities- we are also able to distinguish between properties of universities with as well as without selection of one specific local property, the quality of a university in terms of its average field-normalized citation impact. It also reveals an interesting observation concerning the working of a crucial property in networked systems, preferential attachment. PMID:23544062
Study on fibre laser machining quality of plain woven CFRP laminates
NASA Astrophysics Data System (ADS)
Li, Maojun; Li, Shuo; Yang, Xujing; Zhang, Yi; Liang, Zhichao
2018-03-01
Laser cutting is suitable for large-scale and high-efficiency production with relatively high cutting speed, while machining of CFRP composite using lasers is challenging with severe thermal damage due to different material properties and sensitivity to heat. In this paper, surface morphology of cutting plain woven carbon fibre-reinforced plastics (CFRP) by fibre laser and the influence of cutting parameters on machined quality were investigated. A full factorial experimental design was employed involving three variable factors, which included laser pulse frequency at three levels together with laser power and cutting speed at two levels. Heat-affected zone (HAZ), kerf depth and kerf angle were quantified to understand the interactions with cutting parameters. Observations of machined surface were analysed relating to various damages using optical microscope and scanning electron microscopy (SEM), which included HAZ, matrix recession, fibre protruding, striations, fibre-end swelling, collapses, cavities and delamination. Based on ANOVA analysis, it was found that both cutting speed and laser power were significant factors for HAZ and kerf depth, while laser power was the only significant factor for kerf angle. Besides, HAZ and the kerf depth showed similar sensitivity to the pulse energy and energy per unit length, which was opposite for kerf angle. This paper presented the feasibility and experimental results of cutting CFRP laminates using fibre laser, which is possibly the efficient and high-quality process to promote the development of CFRPs.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Eyer, James M.; Schoenung, Susan M.
2008-02-01
The work documented in this report represents another step in the ongoing investigation of innovative and potentially attractive value propositions for electricity storage by the United States Department of Energy (DOE) and Sandia National Laboratories (SNL) Energy Storage Systems (ESS) Program. This study uses updated cost and performance information for modular energy storage (MES) developed for this study to evaluate four prospective value propositions for MES. The four potentially attractive value propositions are defined by a combination of well-known benefits that are associated with electricity generation, delivery, and use. The value propositions evaluated are: (1) transportable MES for electric utilitymore » transmission and distribution (T&D) equipment upgrade deferral and for improving local power quality, each in alternating years, (2) improving local power quality only, in all years, (3) electric utility T&D deferral in year 1, followed by electricity price arbitrage in following years; plus a generation capacity credit in all years, and (4) electric utility end-user cost management during times when peak and critical peak pricing prevail.« less
SQC: secure quality control for meta-analysis of genome-wide association studies.
Huang, Zhicong; Lin, Huang; Fellay, Jacques; Kutalik, Zoltán; Hubaux, Jean-Pierre
2017-08-01
Due to the limited power of small-scale genome-wide association studies (GWAS), researchers tend to collaborate and establish a larger consortium in order to perform large-scale GWAS. Genome-wide association meta-analysis (GWAMA) is a statistical tool that aims to synthesize results from multiple independent studies to increase the statistical power and reduce false-positive findings of GWAS. However, it has been demonstrated that the aggregate data of individual studies are subject to inference attacks, hence privacy concerns arise when researchers share study data in GWAMA. In this article, we propose a secure quality control (SQC) protocol, which enables checking the quality of data in a privacy-preserving way without revealing sensitive information to a potential adversary. SQC employs state-of-the-art cryptographic and statistical techniques for privacy protection. We implement the solution in a meta-analysis pipeline with real data to demonstrate the efficiency and scalability on commodity machines. The distributed execution of SQC on a cluster of 128 cores for one million genetic variants takes less than one hour, which is a modest cost considering the 10-month time span usually observed for the completion of the QC procedure that includes timing of logistics. SQC is implemented in Java and is publicly available at https://github.com/acs6610987/secureqc. jean-pierre.hubaux@epfl.ch. Supplementary data are available at Bioinformatics online. © The Author (2017). Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com
Trombetti, A; Reid, K F; Hars, M; Herrmann, F R; Pasha, E; Phillips, E M; Fielding, R A
2016-02-01
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 life. Our findings reinforce the importance of preserving muscle health with advancing age. The age-associated loss of skeletal muscle quantity and function are critical determinants of independent physical functioning in later life. Longitudinal studies investigating how decrements in muscle components of sarcopenia impact fear of falling (FoF) and quality of life (QoL) in older adults are lacking. Twenty-six healthy older subjects (age, 74.1 ± 3.7; Short Physical Performance Battery (SPPB) score ≥10) and 22 mobility-limited older subjects (age, 77.2 ± 4.4; SPPB score ≤9) underwent evaluations of lower extremity muscle size and composition by computed tomography, strength and power, and physical performance at baseline and after 3-year follow-up. The Falls Efficacy Scale (FES) and Short Form-36 questionnaire (SF-36) were also administered at both timepoints to assess FoF and QoL, respectively. At 3-year follow-up, muscle cross-sectional area (CSA) (p < 0.013) and power decreased (p < 0.001), while intermuscular fat infiltration increased (p < 0.001). These decrements were accompanied with a longer time to complete 400 m by 22 ± 46 s (p < 0.002). Using linear mixed-effects regression models, declines of muscle CSA, strength and power, and SPPB score were associated with increased FES score (p < 0.05 for each model). Reduced physical component summary score of SF-36 over follow-up was independently associated with decreased SPPB score (p < 0.020), muscle CSA (p < 0.046), and increased 400 m walk time (p < 0.003). In older adults with and without mobility limitations, declining muscle mass, strength, power, and physical performance contribute independently to increase FoF, while declines of muscle mass and physical performance contribute to deterioration of QoL. These findings provide further rationale for developing interventions to improve aging muscle health.
Measurement of CO 2, CO, SO 2, and NO emissions from coal-based thermal power plants in India
NASA Astrophysics Data System (ADS)
Chakraborty, N.; Mukherjee, I.; Santra, A. K.; Chowdhury, S.; Chakraborty, S.; Bhattacharya, S.; Mitra, A. P.; Sharma, C.
Measurements of CO 2 (direct GHG) and CO, SO 2, NO (indirect GHGs) were conducted on-line at some of the coal-based thermal power plants in India. The objective of the study was three-fold: to quantify the measured emissions in terms of emission coefficient per kg of coal and per kWh of electricity, to calculate the total possible emission from Indian thermal power plants, and subsequently to compare them with some previous studies. Instrument IMR 2800P Flue Gas Analyzer was used on-line to measure the emission rates of CO 2, CO, SO 2, and NO at 11 numbers of generating units of different ratings. Certain quality assurance (QA) and quality control (QC) techniques were also adopted to gather the data so as to avoid any ambiguity in subsequent data interpretation. For the betterment of data interpretation, the requisite statistical parameters (standard deviation and arithmetic mean) for the measured emissions have been also calculated. The emission coefficients determined for CO 2, CO, SO 2, and NO have been compared with their corresponding values as obtained in the studies conducted by other groups. The total emissions of CO 2, CO, SO 2, and NO calculated on the basis of the emission coefficients for the year 2003-2004 have been found to be 465.667, 1.583, 4.058, and 1.129 Tg, respectively.
NASA Technical Reports Server (NTRS)
Vomaske, R. F.; Innis, R. C.; Swan, B. E.; Grossmith, S. W.
1978-01-01
The stability, control, and handling qualities of an augmented jet flap STOL airplane are presented. The airplane is an extensively modified de Havilland Buffalo military transport. The modified airplane has two fan-jet engines which provide vectorable thrust and compressed air for the augmentor jet flap and Boundary-Layer Control (BLC). The augmentor and BLC air is cross ducted to minimize asymmetric moments produced when one engine is inoperative. The modifications incorporated in the airplane include a Stability Augmentation System (SAS), a powered elevator, and a powered lateral control system. The test gross weight of the airplane was between 165,000 and 209,000 N (37,000 and 47,000 lb). Stability, control, and handling qualities are presented for the airspeed range of 40 to 180 knots. The lateral-directional handling qualities are considered satisfactory for the normal operating range of 65 to 160 knots airspeed when the SAS is functioning. With the SAS inoperative, poor turn coordination and spiral instability are primary deficiencies contributing to marginal handling qualities in the landing approach. The powered elevator control system enhanced the controllability in pitch, particularly in the landing flare and stall recovery.
Nuclear Power: Is It a New Clear Choice for Malaysia
NASA Astrophysics Data System (ADS)
Besar, Idris B.
2008-05-01
Energy is essential for socio-economic development. Any nation's standard of living is closely related to its access to energy. To put into perspective, the per capita electricity consumptions in developed countries of the Organisation for Economic Cooperation and Development (OECD) is currently estimated at 8600 kilowatts-hour per year as compared to the consumption rates in Malaysia and some African countries of 3300 and 50 kilowatts-hour per year, respectively. Energy is therefore an important pre-requisite for achieving the Malaysian vision of becoming a developed nation by the year 2020, in that it is needed not only for industrialization programme but also in maintaining quality of life. In Malaysia, the main concern currently is still on the supply in term of adequacy, reliability and quality; and moving slowly but steadily towards security, sustainability, environmentally friendly and contribution to climate change. With this new dimension, nuclear power emerged as a good match to a possible alternative in the comprehensive national energy policy. Many studies presented the positive aspects of nuclear power while others indicated the bad sides and potential risks. This paper will highlight some of those pros and cons as well as the potential risks beside a discussion on relevant requirements for a nuclear power programme in particular those of interest to the professionals in the physical sciences.
NASA Astrophysics Data System (ADS)
Wei, Yan-Peng; Li, Mao-Hui; Yu, Gang; Wu, Xian-Qian; Huang, Chen-Guang; Duan, Zhu-Ping
2012-10-01
The mechanical properties of laser welded joints under impact loadings such as explosion and car crash etc. are critical for the engineering designs. The hardness, static and dynamic mechanical properties of AISI304 and AISI316 L dissimilar stainless steel welded joints by CO2 laser were experimentally studied. The dynamic strain-stress curves at the strain rate around 103 s-1 were obtained by the split Hopkinson tensile bar (SHTB). The static mechanical properties of the welded joints have little changes with the laser power density and all fracture occurs at 316 L side. However, the strain rate sensitivity has a strong dependence on laser power density. The value of strain rate factor decreases with the increase of laser power density. The welded joint which may be applied for the impact loading can be obtained by reducing the laser power density in the case of welding quality assurance.
Dong, Jian-Jun; Li, Qing-Liang; Yin, Hua; Zhong, Cheng; Hao, Jun-Guang; Yang, Pan-Fei; Tian, Yu-Hong; Jia, Shi-Ru
2014-10-15
Sensory evaluation is regarded as a necessary procedure to ensure a reproducible quality of beer. Meanwhile, high-throughput analytical methods provide a powerful tool to analyse various flavour compounds, such as higher alcohol and ester. In this study, the relationship between flavour compounds and sensory evaluation was established by non-linear models such as partial least squares (PLS), genetic algorithm back-propagation neural network (GA-BP), support vector machine (SVM). It was shown that SVM with a Radial Basis Function (RBF) had a better performance of prediction accuracy for both calibration set (94.3%) and validation set (96.2%) than other models. Relatively lower prediction abilities were observed for GA-BP (52.1%) and PLS (31.7%). In addition, the kernel function of SVM played an essential role of model training when the prediction accuracy of SVM with polynomial kernel function was 32.9%. As a powerful multivariate statistics method, SVM holds great potential to assess beer quality. Copyright © 2014 Elsevier Ltd. All rights reserved.
Manzambi Kuwekita, J; Gosset, C; Guillaume, M; Balula Semutsari, M-P; Tshiama Kabongo, E; Bruyere, O; Reginster, J-Y
2015-01-01
This study, based on a survey conducted in 2008, examines how combining microcredit, microinsurance, and health care provision can improve access to quality care in the health zone of Bandalungwa, in Kinshasa. The bivariate analysis showed a significant association between increased purchasing power and earnings (p = 0.001), between earnings and savings (p = 0.000), and between health insurance and improved access to health care. These results show that 68.8% of borrowers reported an increase in their purchasing power, of whom 82% reported profits. Those with savings were 24.7 times more likely to purchase health insurance than those without; and 72% of those who regularly made health insurance payments improved their access to care. Combining microcredit, health microinsurance, and health care can improve access to quality health care at lower cost. This suggests that health insurance could usefully be integrated into the primary health-care system.
INTEGRATED POWER GENERATION SYSTEMS FOR COAL MINE WASTE METHANE UTILIZATION
DOE Office of Scientific and Technical Information (OSTI.GOV)
Peet M. Soot; Dale R. Jesse; Michael E. Smith
2005-08-01
An integrated system to utilize the waste coal mine methane (CMM) at the Federal No. 2 Coal Mine in West Virginia was designed and built. The system includes power generation, using internal combustion engines, along with gas processing equipment to upgrade sub-quality waste methane to pipeline quality standards. The power generation has a nominal capacity of 1,200 kw and the gas processing system can treat about 1 million cubic feet per day (1 MMCFD) of gas. The gas processing is based on the Northwest Fuel Development, Inc. (NW Fuel) proprietary continuous pressure swing adsorption (CPSA) process that can remove nitrogenmore » from CMM streams. The two major components of the integrated system are synergistic. The byproduct gas stream from the gas processing equipment can be used as fuel for the power generating equipment. In return, the power generating equipment provides the nominal power requirements of the gas processing equipment. This Phase III effort followed Phase I, which was comprised of a feasibility study for the project, and Phase II, where the final design for the commercial-scale demonstration was completed. The fact that NW Fuel is desirous of continuing to operate the equipment on a commercial basis provides the validation for having advanced the project through all of these phases. The limitation experienced by the project during Phase III was that the CMM available to operate the CPSA system on a commercial basis was not of sufficiently high quality. NW Fuel's CPSA process is limited in its applicability, requiring a relatively high quality of gas as the feed to the process. The CPSA process was demonstrated during Phase III for a limited time, during which the processing capabilities met the expected results, but the process was never capable of providing pipeline quality gas from the available low quality CMM. The NW Fuel CPSA process is a low-cost ''polishing unit'' capable of removing a few percent nitrogen. It was never intended to process CMM streams containing high levels of nitrogen, as is now the case at the Federal No.2 Mine. Even lacking the CPSA pipeline delivery demonstration, the project was successful in laying the groundwork for future commercial applications of the integrated system. This operation can still provide a guide for other coal mines which need options for utilization of their methane resources. The designed system can be used as a complete template, or individual components of the system can be segregated and utilized separately at other mines. The use of the CMM not only provides an energy fuel from an otherwise wasted resource, but it also yields an environmental benefit by reducing greenhouse gas emissions. The methane has twenty times the greenhouse effect as compared to carbon dioxide, which the combustion of the methane generates. The net greenhouse gas emission mitigation is substantial.« less
Electrical safety during transplantation.
Amicucci, G L; Di Lollo, L; Fiamingo, F; Mazzocchi, V; Platania, G; Ranieri, D; Razzano, R; Camin, G; Sebastiani, G; Gentile, P
2010-01-01
Technologic innovations enable management of medical equipment and power supply systems, with improvements that can affect the technical aspects, economics, and quality of medical service. Herein are outlined some technical guidelines, proposed by Istituto Superiore per la Prevenzione e la Sicurezza del Lavoro, for increasing the effectiveness of the power supply system and the safety of patients and surgeons in the operating room, with particular focus on transplantation. The dependence of diagnoses and therapies on operation of the electrical equipment can potentially cause great risk to patients. Moreover, it is possible that faulty electrical equipment could produce current that may flow through the patient. Because patients are particularly vulnerable when their natural protection is considerably decreased, as during transplantation or other surgery, power supply systems must operate with a high degree of reliability and quality to prevent risk, and must be designed to reduce hazards from direct and indirect contact. Reliability of the power supply system is closely related to the quality of the project, choice of materials, and management of the system (eg, quality and frequency of servicing). Among the proposed guidelines, other than normal referencing, are (1) adoption of a monitoring system to improve the quality of the electrical parameters in the operating room, (2) institution of emergency procedures for management of electrical faults, (3) a procedure for management of fires in the operating room, (4) and maintenance interventions and inspections of medical devices to maintain minimal requirements of safety and performance. Copyright 2010 Elsevier Inc. All rights reserved.
Strategies for Improving Power in Cluster Randomized Studies of Professional Development
ERIC Educational Resources Information Center
Kelcey, Ben; Spybrook, Jessaca; Zhang, Jiaqi; Phelps, Geoffrey; Jones, Nathan
2015-01-01
With research indicating substantial differences among teachers in terms of their effectiveness (Nye, Konstantopoulous, & Hedges, 2004), a major focus of recent research in education has been on improving teacher quality through professional development (Desimone, 2009; Institute of Educations Sciences [IES], 2012; Measures of Effective…
Comparing HE Policies in Europe
ERIC Educational Resources Information Center
Bleiklie, Ivar; Michelsen, Svein
2013-01-01
The purpose of this paper is to develop a conceptual framework for a comparative analysis of Higher Education policies that enables us to investigate the explanatory power of structural characteristics of politico-administrative systems. The policies that are studied aim at improving the efficiency and quality of institutional performance. The…
Control Strategies and Noncompliance in Abusive Mother-Child Dyads: An Observational Study.
ERIC Educational Resources Information Center
Oldershaw, Lynn; And Others
1986-01-01
Explores the hypothesis that parenting practices of abusive mothers are characterized by (1) greater use of power-assertive strategies, (2) less flexible behavior with respect to child compliance attempts, (3) more inconsistent use of parenting techniques, and (4) diminished affective quality. (HOD)
Neu, Daniel; Mairesse, Olivier; Verbanck, Paul; Le Bon, Olivier
2015-10-01
To investigate slow wave sleep (SWS) spectral power proportions in distinct clinical conditions sharing non-restorative sleep and fatigue complaints without excessive daytime sleepiness (EDS), namely the chronic fatigue syndrome (CFS) and primary insomnia (PI). Impaired sleep homeostasis has been suspected in both CFS and PI. We compared perceived sleep quality, fatigue and sleepiness symptom-intensities, polysomnography (PSG) and SWS spectral power distributions of drug-free CFS and PI patients without comorbid sleep or mental disorders, with a good sleeper control group. Higher fatigue without EDS and impaired perceived sleep quality were confirmed in both patient groups. PSG mainly differed in sleep fragmentation and SWS durations. Spectral analysis revealed a similar decrease in central ultra slow power (0.3-0.79Hz) proportion during SWS for both CFS and PI and an increase in frontal power proportions of faster frequencies during SWS in PI only. The latter was correlated to affective symptoms whereas lower central ultra slow power proportions were related to fatigue severity and sleep quality impairment. In combination with normal (PI) or even increased SWS durations (CFS), we found consistent evidence for lower proportions of slow oscillations during SWS in PI and CFS. Observing normal or increased SWS durations but lower proportions of ultra slow power, our findings suggest a possible quantitative compensation of altered homeostatic regulation. Copyright © 2015 International Federation of Clinical Neurophysiology. Published by Elsevier Ireland Ltd. All rights reserved.
Wilcox, S.; Andreas, A.
2010-09-27
The U.S. Department of Energy's National Renewable Energy Laboratory collaborates with the solar industry to establish high quality solar and meteorological measurements. This Solar Resource and Meteorological Assessment Project (SOLRMAP) provides high quality measurements to support deployment of power projects in the United States. The no-funds-exchanged collaboration brings NREL solar resource assessment expertise together with industry needs for measurements. The end result is high quality data sets to support the financing, design, and monitoring of large scale solar power projects for industry in addition to research-quality data for NREL model development. NREL provides consultation for instrumentation and station deployment, along with instrument calibrations, data acquisition, quality assessment, data distribution, and summary reports. Industry participants provide equipment, infrastructure, and station maintenance.
Li, J; Xu, Z Y; An, H G; Liu, L Q
2007-07-01
A study of using dual membrane technologies, microfiltration (MF) and reverse osmosis (RO), for reclaiming blowdown of the cooling tower was conducted at ZJK power plant, Hebei province, China. The study shows that the combined MF-RO system can effectively reduce water consumption in the power industry. The results indicate that MF process is capable of producing a filtrate suitable for RO treatment and achieving a silt density index (SDI) less than 2, turbidity of 0.2 NTU. The water quality of RO effluent is very good with an average conductivity of about 40 micros/cm and rejection of 98%. The product water is suitable for injection into the cooling tower to counteract with cooling water intrusion. After adopting this system, water-saving effectiveness as expressed in terms of cycles of concentration could be increased from 2.5-2.8 times to 5 times.
Fernandez-Gamboa, Iosu; Yanci, Javier; Granados, Cristina; Camara, Jesus
2017-08-01
Fernandez-Gamboa, I, Yanci, J, Granados, C, and Camara, J. Comparison of anthropometry and lower limb power qualities according to different levels and ranking position of competitive surfers. J Strength Cond Res 31(8): 2231-2237, 2017-The aim of this study was to compare competitive surfers' lower limb power output depending on their competitive level, and to evaluate the association between competition rankings. Twenty competitive surfers were divided according to the competitive level as follows: international (INT) or national (NAT), and competitive ranking (RANK1-50 or RANK51-100). Vertical jump and maximal peak power of the lower limbs were measured. No differences were found between INT and NAT surfers in the anthropometric variables, in the vertical jump, or in lower extremity power; although the NAT group had higher levels on the elasticity index, squat jumps (SJs), and counter movement jumps (CMJs) compared with the INT group. The RANK1-50 group had a lower biceps skinfold (p < 0.01), lower skinfolds in the legs (Front thigh: p ≤ 0.05; medial calf: p < 0.01), lower sum of skinfolds (p ≤ 0.05), higher SJ (p < 0.01), CMJ (p < 0.01), and 15 seconds vertical CMJ (p ≤ 0.05); also, maximal peak power of the right leg (MPPR) and left leg (MPPL) were higher in the RANK1-50 group. Moderate to large significant correlations were obtained between the surfers' ranking position and some skinfolds, the sum of skinfolds, and vertical jump. Results demonstrate that surfers' physical performance seems to be an accurate indicator of ranking positioning, also revealing that vertical jump capacity and anthropometric variables play an important role in their competitive performance, which may be important when considering their power training.
Environmental Quality and the U.S. Power Sector: Air Quality, Land Use and Environmental Justice
DOE Office of Scientific and Technical Information (OSTI.GOV)
Massetti, Emanuele; Brown, Marilyn Ann; Lapsa, Melissa Voss
This baseline report summarizes key environmental quality issues associated with electricity generation, transmission, distribution, and end use in the United States. Its scope includes non-greenhouse gas air pollution (i.e., sulfur dioxide, nitrogen oxides, particulate matter and hazardous air pollutants), land use, water pollution, ecological impacts, human health, and environmental justice. The discussion characterizes both current impacts and recent trends, as well as assessments of key drivers of change. For example, the air emissions section includes a quantitative decomposition analysis of the drivers of change in sulfur dioxide emissions reductions from coal-fired power plants. The report is divided into four topicalmore » sections: air emissions, land use and ecology, water quality, and environmental justice.« less
Water quality study of Sunter River in Jakarta, Indonesia
NASA Astrophysics Data System (ADS)
Martinus, Y.; Astono, W.; Hendrawan, D.
2018-01-01
Sunter River flows in the city of Jakarta with the designation of river water for agricultural purposes, and can be utilized for urban business and hydroelectric power industry. This study aims to determine the Sunter River water quality based on physical and chemical parameters. Water sampling was conducted 2 times which done in April and May with 5 sampling stations for measuring. The samples was analayzed in the laboratory according SNI methods for parameters BOD, COD, PO4 3-, NO3, Oil & Grease and Detergents. The quality status of Sunter River is determined by the Pollutant Index method. The results show that the water quality of Sunter River is influenced by organic parameter as dominant pollutant with COD concentration ranging from 48 mg/l - 182.4 mg/l and BOD concentration ranging from 14.69 mg/L - 98.91 mg/L. The Pollution Index calculation results show that the water quality status of Sunter River is moderate polluted with IP 6.47. The source of pollutants generally comes from the urban drainage channels, tributaries, and slaughtering industry. The results of this study expected to be use by the government to improve the water quality of Sunter River for better environment.
Arduino Due based tool to facilitate in vivo two-photon excitation microscopy
Artoni, Pietro; Landi, Silvia; Sato, Sebastian Sulis; Luin, Stefano; Ratto, Gian Michele
2016-01-01
Two-photon excitation spectroscopy is a powerful technique for the characterization of the optical properties of genetically encoded and synthetic fluorescent molecules. Excitation spectroscopy requires tuning the wavelength of the Ti:sapphire laser while carefully monitoring the delivered power. To assist laser tuning and the control of delivered power, we developed an Arduino Due based tool for the automatic acquisition of high quality spectra. This tool is portable, fast, affordable and precise. It allowed studying the impact of scattering and of blood absorption on two-photon excitation light. In this way, we determined the wavelength-dependent deformation of excitation spectra occurring in deep tissues in vivo. PMID:27446677
NASA Astrophysics Data System (ADS)
Jia, Yan; Shibata, Ryosuke; Yamamura, Naoki; Ishida, Muneaki
To resolve energy shortage and global warming problem, renewable natural resource and its power system has been gradually generalizing. However, the power fluctuation suppressing in short period and the balance control of consumption and supply in long period are two of main problems that need to be resolved urgently in natural energy power system. In Stand-alone Natural Energy Power System (SNEPS) with power energy storage devices, power fluctuation in short period is one of the main reasons that recharge cycle times increase and lead-acid battery early failure. Hence, to prolong the service life of lead-acid battery and improve power quality through suppressing the power fluctuation, we proposed a method of electric power smoothing for lead-acid battery of SNEPS using bi-directional Buck/Boost converter and Electric Double Layer Capacitor (EDLC) in this paper. According to the test data of existing SNEPS, a power fluctuation condition is selected and as an example to analyze the validity of the proposed method. The analysis of frequency characteristics indicates the power fluctuation is suppressed a desired range in the target frequency region. The experimental results of confirmed the feasibility of the proposed system and the results well satisfy the requirement of system design.
Effects of laser power density and initial grain size in laser shock punching of pure copper foil
NASA Astrophysics Data System (ADS)
Zheng, Chao; Zhang, Xiu; Zhang, Yiliang; Ji, Zhong; Luan, Yiguo; Song, Libin
2018-06-01
The effects of laser power density and initial grain size on forming quality of holes in laser shock punching process were investigated in the present study. Three different initial grain sizes as well as three levels of laser power densities were provided, and then laser shock punching experiments of T2 copper foil were conducted. Based upon the experimental results, the characteristics of shape accuracy, fracture surface morphology and microstructures of punched holes were examined. It is revealed that the initial grain size has a noticeable effect on forming quality of holes punched by laser shock. The shape accuracy of punched holes degrades with the increase of grain size. As the laser power density is enhanced, the shape accuracy can be improved except for the case in which the ratio of foil thickness to initial grain size is approximately equal to 1. Compared with the fracture surface morphology in the quasistatic loading conditions, the fracture surface after laser shock can be divided into three zones including rollover, shearing and burr. The distribution of the above three zones strongly relates with the initial grain size. When the laser power density is enhanced, the shearing depth is not increased, but even diminishes in some cases. There is no obvious change of microstructures with the enhancement of laser power density. However, while the initial grain size is close to the foil thickness, single-crystal shear deformation may occur, suggesting that the ratio of foil thickness to initial grain size has an important impact on deformation behavior of metal foil in laser shock punching process.
10 CFR 50.54 - Conditions of licenses.
Code of Federal Regulations, 2012 CFR
2012-01-01
...)(1) Each nuclear power plant or fuel reprocessing plant licensee subject to the quality assurance... irradiated fuel. (ff) For licensees of nuclear power plants that have implemented the earthquake engineering... of rated thermal power only if the Commission finds that the state of onsite emergency preparedness...
10 CFR 50.54 - Conditions of licenses.
Code of Federal Regulations, 2013 CFR
2013-01-01
...)(1) Each nuclear power plant or fuel reprocessing plant licensee subject to the quality assurance... irradiated fuel. (ff) For licensees of nuclear power plants that have implemented the earthquake engineering... of rated thermal power only if the Commission finds that the state of onsite emergency preparedness...
Unequal power allocation for JPEG transmission over MIMO systems.
Sabir, Muhammad Farooq; Bovik, Alan Conrad; Heath, Robert W
2010-02-01
With the introduction of multiple transmit and receive antennas in next generation wireless systems, real-time image and video communication are expected to become quite common, since very high data rates will become available along with improved data reliability. New joint transmission and coding schemes that explore advantages of multiple antenna systems matched with source statistics are expected to be developed. Based on this idea, we present an unequal power allocation scheme for transmission of JPEG compressed images over multiple-input multiple-output systems employing spatial multiplexing. The JPEG-compressed image is divided into different quality layers, and different layers are transmitted simultaneously from different transmit antennas using unequal transmit power, with a constraint on the total transmit power during any symbol period. Results show that our unequal power allocation scheme provides significant image quality improvement as compared to different equal power allocations schemes, with the peak-signal-to-noise-ratio gain as high as 14 dB at low signal-to-noise-ratios.
Niederman, Richard
2014-09-01
The Cochrane Oral Health Group's Trials Register, the Cochrane Central Register of Controlled Trials (CENTRAL), Medline, Embase, CINAHL, National Institutes of Health Trials Register and the WHO Clinical Trials Registry Platform for ongoing trials. Reference lists of identified articles were also scanned for relevant papers. Identified manufacturers were contacted for additional information. Only randomised controlled trials comparing manual and powered toothbrushes were considered. Crossover trials were eligible for inclusion if the wash-out period length was more than two weeks. Study assessment and data extraction were carried out independently by at least two reviewers. The primary outcome measures were quantified levels of plaque or gingivitis. Risk of bias assessment was undertaken. Standard Cochrane methodological approaches were taken. Random-effects models were used provided there were four or more studies included in the meta-analysis, otherwise fixed-effect models were used. Data were classed as short term (one to three months) and long term (greater than three months). Fifty-six trials were included with 51 (4624 patients) providing data for meta-analysis. The majority (46) were at unclear risk of bias, five at high risk of bias and five at low risk. There was moderate quality evidence that powered toothbrushes provide a statistically significant benefit compared with manual toothbrushes with regard to the reduction of plaque in both the short and long-term. This corresponds to an 11% reduction in plaque for the Quigley Hein index (Turesky) in the short term and a 21% reduction in the long term. There was a high degree of heterogeneity that was not explained by the different powered toothbrush type subgroups.There was also moderate quality evidence that powered toothbrushes again provide a statistically significant reduction in gingivitis when compared with manual toothbrushes both in the short and long term. This corresponds to a 6% and 11% reduction in gingivitis for the Löe and Silness indices respectively. Again there was a high degree of heterogeneity that was not explained by the different powered toothbrush type subgroups. The greatest body of evidence was for rotation oscillation brushes which demonstrated a statistically significant reduction in plaque and gingivitis at both time points. Powered toothbrushes reduce plaque and gingivitis more than manual toothbrushing in the short and long term. The clinical importance of these findings remains unclear. Observation of methodological guidelines and greater standardisation of design would benefit both future trials and meta-analyses. Cost, reliability and side effects were inconsistently reported. Any reported side effects were localised and only temporary.
The relationship between depressive symptoms among female workers and job stress and sleep quality
2013-01-01
Objective Recently, workers' mental health has become important focus in the field of occupational health management. Depression is a psychiatric illness with a high prevalence. The association between job stress and depressive symptoms has been demonstrated in many studies. Recently, studies about the association between sleep quality and depressive symptoms have been reported, but there has been no large-scaled study in Korean female workers. Therefore, this study was designed to investigate the relationship between job stress and sleep quality, and depressive symptoms in female workers. Methods From Mar 2011 to Aug 2011, 4,833 female workers in the manufacturing, finance, and service fields at 16 workplaces in Yeungnam province participated in this study, conducted in combination with a worksite-based health checkup initiated by the National Health Insurance Service (NHIS). In this study, a questionnaire survey was carried out using the Korean Occupational Stress Scale-Short Form(KOSS-SF), Pittsburgh Sleep Quality Index(PSQI) and Center for Epidemiological Studies-Depression Scale(CES-D). The collected data was entered in the system and analyzed using the PASW (version 18.0) program. A correlation analysis, cross analysis, multivariate logistic regression analysis, and hierarchical multiple regression analysis were conducted. Results Among the 4,883 subjects, 978 subjects (20.0%) were in the depression group. Job stress(OR=3.58, 95% CI=3.06-4.21) and sleep quality(OR=3.81, 95% CI=3.18-4.56) were strongly associated with depressive symptoms. Hierarchical multiple regression analysis revealed that job stress displayed explanatory powers of 15.6% on depression while sleep quality displayed explanatory powers of 16.2%, showing that job stress and sleep quality had a closer relationship with depressive symptoms, compared to the other factors. The multivariate logistic regression analysis yielded odds ratios between the 7 subscales of job stress and depressive symptoms in the range of 1.30-2.72 and the odds ratio for the lack of reward was the highest(OR=2.72, 95% CI=2.32-3.19). In the partial correlation analysis between each of the 7 subscales of sleep quality (PSQI) and depressive symptoms, the correlation coefficient of subjective sleep quality and daytime dysfunction were 0.352 and 0.362, respectively. Conclusion This study showed that the depressive symptoms of female workers are closely related to their job stress and sleep quality. In particular, the lack of reward and subjective sleep factors are the greatest contributors to depression. In the future, a large-scale study should be performed to augment the current study and to reflect all age groups in a balanced manner. The findings on job stress, sleep, and depression can be utilized as source data to establish standards for mental health management of the ever increasing numbers of female members of the workplace. PMID:24472381
Subjective sleep disturbance in Chinese adults with epilepsy: Associations with affective symptoms.
Shen, Yeru; Zhang, Mengmeng; Wang, Yu; Wang, Lanlan; Xu, Xiangjun; Xiao, Gairong; Chen, Jing; Zhang, Ting; Zhou, Nong
2017-09-01
As well as being a very common neurological disease worldwide, epilepsy significantly impairs patients' emotional, behavioral, and cognitive functioning. Sleep disturbances are the most frequent complaint in patients with epilepsy. The present study assesses the impact of a range of affective symptoms on subjective sleep quality and sleep disturbances in Chinese adults with epilepsy. Adults with epilepsy who visited our epilepsy clinic from July 2015 to March 2016 were enrolled in our study. Both patients and healthy controls completed the Pittsburgh Sleep Quality Index (PSQI), Epworth Sleepiness Scale (ESS), Insomnia Severity Index (ISI), Beck Depression Inventory-II (BDI-II), Beck Anxiety Inventory (BAI), and Mini-mental State Examination (MMSE). Subjective sleep quality and sleep disturbances were examined with regard to self-reported symptoms of depression and anxiety, seizure-related factors, and demographic factors. The PSQI scores and ISI scores of patients were significantly higher (indicating lower quality sleep and more serious insomnia) than those of the control group. Symptoms associated with depression and anxiety were independently related to impaired subjective sleep quality and insomnia. Affective symptoms explained more of the variance in PSQI scores and ISI scores than did seizure-related or demographic variables. In addition, these variables also seemed to be less powerful contributing factors to subjective sleep quality and insomnia than affective symptoms, several seizure-related factors, such as seizure control, partial seizures and duration of epilepsy, which are also significantly associated with subjective sleep quality and insomnia. In addition, use of lamotrigine (LTG) was also associated with insomnia and use of clonazepam (CZP) and phenobarbital (PB) with daytime sleepiness in patients with epilepsy. Chinese adults with epilepsy have poorer self-reported subjective sleep quality and a higher prevalence of insomnia than the control group. Depressive- and anxiety-related symptoms independently exert an adverse effect on the subjective sleep quality and insomnia of patients. In addition, seizure control, partial seizures, and the duration of epilepsy affect the quality of sleep and insomnia in patients, but seem less powerful predictors of sleep quality and insomnia than affective symptoms. Early identification and treatment of affective symptoms is of great importance in improving the sleep quality and insomnia of patients with epilepsy. Copyright © 2017 Elsevier B.V. All rights reserved.
The Evolution of the Quality Agenda in Higher Education: The Politics of Legitimation
ERIC Educational Resources Information Center
Filippakou, Ourania
2017-01-01
Taking the evolution of the quality agenda in the UK as its centrepiece, this article analyses the politics of legitimation accompanying the emergence of quality assurance and the contribution of quality enhancement to the power play therein. This article argues that over the last 25 years the quality agenda has been used as a proxy--a state…
Optimization of operator and physical parameters for laser welding of dental materials.
Bertrand, C; le Petitcorps, Y; Albingre, L; Dupuis, V
2004-04-10
Interactions between lasers and materials are very complex phenomena. The success of laser welding procedures in dental metals depends on the operator's control of many parameters. The aims of this study were to evaluate factors relating to the operator's dexterity and the choice of the welding parameters (power, pulse duration and therefore energy), which are recognized determinants of weld quality. In vitro laboratory study. FeNiCr dental drawn wires were chosen for these experiments because their properties are well known. Different diameters of wires were laser welded, then tested in tension and compared to the control material as extruded, in order to evaluate the quality of the welding. Scanning electron microscopy of the fractured zone and micrograph observations perpendicular and parallel to the wire axis were also conducted in order to analyse the depth penetration and the quality of the microstructure. Additionally, the micro-hardness (Vickers type) was measured both in the welded and the heat-affected zones and then compared to the non-welded alloy. Adequate combination of energy and pulse duration with the power set in the range between 0.8 to 1 kW appears to improve penetration depth of the laser beam and success of the welding procedure. Operator skill is also an important variable. The variation in laser weld quality in dental FeNiCr wires attributable to operator skill can be minimized by optimization of the physical welding parameters.
Cretin, S; Farley, D O; Dolter, K J; Nicholas, W
2001-08-01
Implementing clinical practice guidelines to change patient outcomes presents a challenge. Studies of single interventions focused on changing provider behavior demonstrate modest effects, suggesting that effective guideline implementation requires a multifaceted approach. Traditional biomedical research designs are not well suited to evaluating systems interventions. RAND and the Army Medical Department collaborated to develop and evaluate a system for implementing guidelines and documenting their effects on patient care. The evaluation design blended quality improvement, case study, and epidemiologic methods. A formative evaluation of implementation process and an outcome evaluation of patient impact were combined. Guidelines were implemented in 3 successive demonstrations targeting low back pain, asthma, and diabetes. This paper reports on the first wave of 4 facilities implementing a low back pain guideline. Organizational climate and culture, motivation, leadership commitment, and resources were assessed. Selected indicators of processes and outcomes of care were compared before, during, and after guideline implementation at the demonstration facilities and at comparison facilities. Logistic regression analysis was used to test for guideline effects on patient care. Process evaluation documented varied approaches to quality improvement across sites. Outcome evaluation revealed a significant downward trend in the percentage of acute low back pain patients referred to physical therapy or chiropractic care (10.7% to 7.2%) at demonstration sites and no such trend at control sites. Preliminary results suggest the power of this design to stimulate improvements in guideline implementation while retaining the power to evaluate rigorously effects on patient care.
Nurse executive transformational leadership found in participative organizations.
Dunham-Taylor, J
2000-05-01
The study examined a national sample of 396 randomly selected hospital nurse executives to explore transformational leadership, stage of power, and organizational climate. Results from a few nurse executive studies have found nurse executives were transformational leaders. As executives were more transformational, they achieved better staff satisfaction and higher work group effectiveness. This study integrates Bass' transformational leadership model with Hagberg's power stage theory and Likert's organizational climate theory. Nurse executives (396) and staff reporting to them (1,115) rated the nurse executives' leadership style, staff extra effort, staff satisfaction, and work group effectiveness using Bass and Avolio's Multifactor Leadership Questionnaire. Executives' bosses (360) rated executive work group effectiveness. Executives completed Hagberg's Personal Power Profile and ranked their organizational climate using Likert's Profile of Organizational Characteristics. Nurse executives used transformational leadership fairly often; achieved fairly satisfied staff levels; were very effective according to bosses; were most likely at stage 3 (power by achievement) or stage 4 (power by reflection); and rated their hospital as a Likert System 3 Consultative Organization. Staff satisfaction and work group effectiveness decreased as nurse executives were more transactional. Higher transformational scores tended to occur with higher educational degrees and within more participative organizations. Transformational qualities can be enhanced by further education, by achieving higher power stages, and by being within more participative organizations.
The wind power prediction research based on mind evolutionary algorithm
NASA Astrophysics Data System (ADS)
Zhuang, Ling; Zhao, Xinjian; Ji, Tianming; Miao, Jingwen; Cui, Haina
2018-04-01
When the wind power is connected to the power grid, its characteristics of fluctuation, intermittent and randomness will affect the stability of the power system. The wind power prediction can guarantee the power quality and reduce the operating cost of power system. There were some limitations in several traditional wind power prediction methods. On the basis, the wind power prediction method based on Mind Evolutionary Algorithm (MEA) is put forward and a prediction model is provided. The experimental results demonstrate that MEA performs efficiently in term of the wind power prediction. The MEA method has broad prospect of engineering application.
Development of Jet Noise Power Spectral Laws Using SHJAR Data
NASA Technical Reports Server (NTRS)
Khavaran, Abbas; Bridges, James
2009-01-01
High quality jet noise spectral data measured at the Aeroacoustic Propulsion Laboratory at the NASA Glenn Research Center is used to examine a number of jet noise scaling laws. Configurations considered in the present study consist of convergent and convergent-divergent axisymmetric nozzles. Following the work of Viswanathan, velocity power factors are estimated using a least squares fit on spectral power density as a function of jet temperature and observer angle. The regression parameters are scrutinized for their uncertainty within the desired confidence margins. As an immediate application of the velocity power laws, spectral density in supersonic jets are decomposed into their respective components attributed to the jet mixing noise and broadband shock associated noise. Subsequent application of the least squares method on the shock power intensity shows that the latter also scales with some power of the shock parameter. A modified shock parameter is defined in order to reduce the dependency of the regression factors on the nozzle design point within the uncertainty margins of the least squares method.
Quality and customer satisfaction: A case study in Brazil
NASA Astrophysics Data System (ADS)
Barcellos, Paulo Fernando Pinto
The dissertation deals with the case of CEEE-Companhia Estadual de Energia Eletrica, an electric power utility located in Rio Grande do Sul, the southernmost state of Brazil. Customer satisfaction with the services provided by CEEE is investigated within three groups of consumers: residential, commercial, and industrial. The purpose of the dissertation is to find answers to the following research questions: (1) What is service quality in public utilities, and particularly in an electric power company? (2) What service quality dimensions do customers want to be provided and favor the most? (3) How does the market measure service quality? (4) What should be done by companies, and particularly by an electric utility monopoly, to increase the performance of the rendered service? (5) How does this impact customer satisfaction, retention, and intention to recommend? and (6) How do we start a company-wide quality program provided that the resources are scarce and therefore priorities should be set forth? To investigate the posed questions, the study begins with an exploratory survey of CEEE's Board. The survey is followed by qualitative research of the three customer groups. After qualitative analysis of the data is concluded, questionnaires for the quantitative research, as well as hypothetical models, are developed. Dillman's "Total Design Method" is used to design the questionnaires. The basic ACSI (American Customer Satisfaction Model) is used to approach customer satisfaction. Data are processed by PLS (Partial Least Squares) which follows the procedure developed at the National Quality Research Center of the University of Michigan Business School. In summary, commercial customers are the most dissatisfied with the services provided by CEEE, while residential customers are the most satisfied. To improve quality, priority should be placed on commercial customers and include efforts to improve productivity gains throughout the company. Also, CEEE's image should be improved through a better communication process with the market and an intensive and extensive training of personnel. A special marketing campaign could help build a better image by explaining CEEE's goals to improve quality. Finally, a bottom line of satisfaction scores (as quality indicators) should be set for the entire company.
Feasibility of eyes open alpha power training for mental enhancement in elite gymnasts.
Dekker, Marian K J; van den Berg, Berber R; Denissen, Ad J M; Sitskoorn, Margriet M; van Boxtel, Geert J M
2014-01-01
This study focuses on a novel, easy to use and instruction-less method for mental training in athletes. Previous findings suggest that particular mental capacities are needed for achieving peak performance; including attentional control, focus, relaxation and positive affect. Electroencephalography (EEG) alpha brain activity has been associated with neural inhibition during processes of selective attention, for improving efficiency in information processing. Here we hypothesised that eyes open alpha power training by music teaches athletes to (1) learn to self-regulate their brain activity, and (2) learn to increase their baseline alpha power, herewith improving mental capacities such as focusing the allocation of attention. The study was double-blind and placebo-controlled. Twelve elite gymnasts were either given eyes open alpha power training or random beta power training (controls). Results indicate small improvements in sleep quality, mental and physical shape. In our first attempt at getting a grip on mental capacities in athletes, we think this novel training method can be promising. Because gymnastics is one of the most mentally demanding sports, we value even small benefits for the athlete and consider them indicative for future research.
Fuels research studies at NASA Lewis
NASA Technical Reports Server (NTRS)
Antoine, A. C.
1982-01-01
Fuels research studies carried out in a variety of areas related to aviation propulsion, ground transportation, and stationary power generation systems are discussed. The major efforts are directed to studies on fuels for jet aircraft. These studies involve fuels preparation, fuels analysis, and fuel quality evaluations. The scope and direction of research activities in these areas is discussed, descriptions of Lewis capabilities and facilities given, and results of recent research efforts reported.
Game-theoretic approach to joint transmitter adaptation and power control in wireless systems.
Popescu, Dimitrie C; Rawat, Danda B; Popescu, Otilia; Saquib, Mohamad
2010-06-01
Game theory has emerged as a new mathematical tool in the analysis and design of wireless communication systems, being particularly useful in studying the interactions among adaptive transmitters that attempt to achieve specific objectives without cooperation. In this paper, we present a game-theoretic approach to the problem of joint transmitter adaptation and power control in wireless systems, where users' transmissions are subject to quality-of-service requirements specified in terms of target signal-to-interference-plus-noise ratios (SINRs) and nonideal vector channels between transmitters and receivers are explicitly considered. Our approach is based on application of separable games, which are a specific class of noncooperative games where the players' cost is a separable function of their strategic choices. We formally state a joint codeword and power adaptation game, which is separable, and we study its properties in terms of its subgames, namely, the codeword adaptation subgame and the power adaptation subgame. We investigate the necessary conditions for an optimal Nash equilibrium and show that this corresponds to an ensemble of user codewords and powers, which maximizes the sum capacity of the corresponding multiaccess vector channel model, and for which the specified target SINRs are achieved with minimum transmitted power.
Focus-tunable low-power electrowetting lenses with thin parylene films.
Watson, Alexander M; Dease, Kevin; Terrab, Soraya; Roath, Christopher; Gopinath, Juliet T; Bright, Victor M
2015-07-10
Electrowetting lenses with record low power consumption (microwatts) have been demonstrated using high-quality parylene AF-4 dielectric layers and large dodecyl sulfate ions. Water and propylene glycol are interchanged as the polar liquid to enable diverging and converging lens operation achievable with the application of 15 V. The optical quality of the lenses is comparable to conventional microlenses and the tuning exhibits very little (<0.5°) contact angle hysteresis.
From nuclear power to coal power: Aerosol-induced health and radiative effects
NASA Astrophysics Data System (ADS)
Mielonen, Tero; Laakso, Anton; Karhunen, Anni; Kokkola, Harri; Partanen, Antti-Ilari; Korhonen, Hannele; Romakkaniemi, Sami; Lehtinen, Kari E. J.
2015-12-01
We have investigated what would be the climate and PM-induced air quality consequences if all nuclear reactors worldwide were closed down and replaced by coal combustion. In a way, this presents a "worst-case scenario" since less polluting energy sources are available. We studied simultaneously the radiative and health effects of coal power emissions using a global 3-D aerosol-climate model (ECHAM-HAMMOZ). This approach allowed us to estimate the effects of a major global energy production change from low carbon source to a high carbon one using detailed spatially resolved population density information. We included the radiative effects of both CO2 and PM2.5 but limited the study of health effects to PM2.5 only. Our results show that the replacement of nuclear power with coal power would have globally caused an average of 150,000 premature deaths per year during the period 2005-2009 with two thirds of them in Europe. For 37 years the aerosol emissions from the additional coal power plants would cool the climate but after that the accumulating CO2 emissions would accelerate the warming of the climate.
Application of Thermoelectric Devices to Fuel Cell Power Generation: Demonstration and Evaluation
2004-09-01
various forms of the ERDC/CERL TR-04-20 63 Rankine thermodynamic cycle (e.g., reheat, regeneration, supercritical). These central power plants can...placement of the TE Device in the condenser receiv- ing the low-quality steam exhaust or into the closed feedwater heaters used to preheat incoming...ability to more efficiently construct, operate, and maintain its installations and ensure environmental quality and safety at a reduced life- cycle -cost
Power conditioning system modelling for nuclear electric propulsion
NASA Astrophysics Data System (ADS)
Metcalf, Kenneth J.
1993-11-01
NASA LeRC is currently developing a Fortran based model of a complete nuclear electric propulsion (NEP) vehicle that would be used for piloted and cargo missions to the Moon or Mars. The proposed vehicle design will use either a Brayton or K-Rankine power conversion cycle to drive a turbine coupled with a rotary alternator. Two thruster types are also being studied, ion and magnetoplasmadynamic (MPD). In support of this NEP model, Rocketdyne developed a power management and distribution (PMAD) subroutine that provides parametric outputs for selected alternator operating voltages and frequencies, thruster types, system power levels, and electronics coldplate temperatures. The end-to-end PMAD model described is based on the direct use of the alternator voltage and frequency for transmitting power to either ion or MPD thrusters. This low frequency transmission approach was compared with dc and high frequency ac designs, and determined to have the lowest mass, highest efficiency, highest reliability and lowest development costs. While its power quality is not as good as that provided by a high frequency system, it was considered adequate for both ion and MPD engine applications. The low frequency architecture will be used as the reference in future NEP PMAD studies.
Power Conditioning System Modelling for Nuclear Electric Propulsion
NASA Technical Reports Server (NTRS)
Metcalf, Kenneth J.
1993-01-01
NASA LeRC is currently developing a Fortran based model of a complete nuclear electric propulsion (NEP) vehicle that would be used for piloted and cargo missions to the Moon or Mars. The proposed vehicle design will use either a Brayton or K-Rankine power conversion cycle to drive a turbine coupled with a rotary alternator. Two thruster types are also being studied, ion and magnetoplasmadynamic (MPD). In support of this NEP model, Rocketdyne developed a power management and distribution (PMAD) subroutine that provides parametric outputs for selected alternator operating voltages and frequencies, thruster types, system power levels, and electronics coldplate temperatures. The end-to-end PMAD model described is based on the direct use of the alternator voltage and frequency for transmitting power to either ion or MPD thrusters. This low frequency transmission approach was compared with dc and high frequency ac designs, and determined to have the lowest mass, highest efficiency, highest reliability and lowest development costs. While its power quality is not as good as that provided by a high frequency system, it was considered adequate for both ion and MPD engine applications. The low frequency architecture will be used as the reference in future NEP PMAD studies.
Erickson, Larry E.; Jennings, Merrisa
2017-01-01
The Paris Agreement on Climate Change has the potential to improve air quality and human health by encouraging the electrification of transportation and a transition from coal to sustainable energy. There will be human health benefits from reducing combustion emissions in all parts of the world. Solar powered charging infrastructure for electric vehicles adds renewable energy to generate electricity, shaded parking, and a needed charging infrastructure for electric vehicles that will reduce range anxiety. The costs of wind power, solar panels, and batteries are falling because of technological progress, magnitude of commercial activity, production experience, and competition associated with new trillion dollar markets. These energy and transportation transitions can have a very positive impact on health. The energy, transportation, air quality, climate change, health nexus may benefit from additional progress in developing solar powered charging infrastructure. PMID:29922702
Employee Empowerment in Manufacturing: A Study of Organisations in the UK.
ERIC Educational Resources Information Center
Psoinos, Anna; Smithson, Steve
2002-01-01
Employee empowerment in the United Kingdom manufacturing industry (through total quality management, delayering, and business process reengineering) was examined in a survey of 103 companies. Success factors included a solid business rationale, organizational culture, and staff decision making power. Culture was also the most influential…
A Structural Equation Model of Predictors for Effective Online Learning
ERIC Educational Resources Information Center
Marks, Ronald B.; Sibley, Stanley D.; Arbaugh, J. B.
2005-01-01
In studying online learning, researchers should examine three critical interactions: instructor-student, student-student, and student-content. Student-content interaction may include a wide variety of pedagogical tools (e.g., streaming media, PowerPoint, and hyperlinking). Other factors that can affect the perceived quality of online learning…
Effects of Cathode Surface Roughness on the Quality of Electron Beams
1986-09-12
ignored. Thus, magnetic field effects are ignored altogether in the present study and the beam tranverse velocities are caused only by the electrostatic...in experiments. This depends on the resolving power and on the competing effects such as nonlinear space charge and thermal effects. Based on the
Computers, Invention, and the Power to Change Student Writing.
ERIC Educational Resources Information Center
Strickland, James
A study examined the quantity and quality of ideas produced in freshman composition students' writing to determine whether computer assisted instruction (CAI) stimulates invention as well as or better than current invention instruction in traditional classrooms. Two CAI programs were used: QUEST, the systematic program that examines an item/event…
Diet quality influences isotopic discrimination among amino acids in an aquatic vertebrate
USDA-ARS?s Scientific Manuscript database
Stable nitrogen isotopic composition of amino acids has recently been employed as a powerful tool in ecological food web studies, particularly for estimating the trophic position (TP) of animal species in food webs. However, the validity of these estimates depends on the consistency of the trophic d...
Automatic-Control System for Safer Brazing
NASA Technical Reports Server (NTRS)
Stein, J. A.; Vanasse, M. A.
1986-01-01
Automatic-control system for radio-frequency (RF) induction brazing of metal tubing reduces probability of operator errors, increases safety, and ensures high-quality brazed joints. Unit combines functions of gas control and electric-power control. Minimizes unnecessary flow of argon gas into work area and prevents electrical shocks from RF terminals. Controller will not allow power to flow from RF generator to brazing head unless work has been firmly attached to head and has actuated micro-switch. Potential shock hazard eliminated. Flow of argon for purging and cooling must be turned on and adjusted before brazing power applied. Provision ensures power not applied prematurely, causing damaged work or poor-quality joints. Controller automatically turns off argon flow at conclusion of brazing so potentially suffocating gas does not accumulate in confined areas.
Enhanced Electric Power Transmission by Hybrid Compensation Technique
NASA Astrophysics Data System (ADS)
Palanichamy, C.; Kiu, G. Q.
2015-04-01
In today's competitive environment, new power system engineers are likely to contribute immediately to the task, without years of seasoning via on-the-job training, mentoring, and rotation assignments. At the same time it is becoming obligatory to train power system engineering graduates for an increasingly quality-minded corporate environment. In order to achieve this, there is a need to make available better-quality tools for educating and training power system engineering students and in-service system engineers too. As a result of the swift advances in computer hardware and software, many windows-based computer software packages were developed for the purpose of educating and training. In line with those packages, a simulation package called Hybrid Series-Shunt Compensators (HSSC) has been developed and presented in this paper for educational purposes.
Anota, Amélie; Barbieri, Antoine; Savina, Marion; Pam, Alhousseiny; Gourgou-Bourgade, Sophie; Bonnetain, Franck; Bascoul-Mollevi, Caroline
2014-12-31
Health-Related Quality of Life (HRQoL) is an important endpoint in oncology clinical trials aiming to investigate the clinical benefit of new therapeutic strategies for the patient. However, the longitudinal analysis of HRQoL remains complex and unstandardized. There is clearly a need to propose accessible statistical methods and meaningful results for clinicians. The objective of this study was to compare three strategies for longitudinal analyses of HRQoL data in oncology clinical trials through a simulation study. The methods proposed were: the score and mixed model (SM); a survival analysis approach based on the time to HRQoL score deterioration (TTD); and the longitudinal partial credit model (LPCM). Simulations compared the methods in terms of type I error and statistical power of the test of an interaction effect between treatment arm and time. Several simulation scenarios were explored based on the EORTC HRQoL questionnaires and varying the number of patients (100, 200 or 300), items (1, 2 or 4) and response categories per item (4 or 7). Five or 10 measurement times were considered, with correlations ranging from low to high between each measure. The impact of informative missing data on these methods was also studied to reflect the reality of most clinical trials. With complete data, the type I error rate was close to the expected value (5%) for all methods, while the SM method was the most powerful method, followed by LPCM. The power of TTD is low for single-item dimensions, because only four possible values exist for the score. When the number of items increases, the power of the SM approach remained stable, those of the TTD method increases while the power of LPCM remained stable. With 10 measurement times, the LPCM was less efficient. With informative missing data, the statistical power of SM and TTD tended to decrease, while that of LPCM tended to increase. To conclude, the SM model was the most powerful model, irrespective of the scenario considered, and the presence or not of missing data. The TTD method should be avoided for single-item dimensions of the EORTC questionnaire. While the LPCM model was more adapted to this kind of data, it was less efficient than the SM model. These results warrant validation through comparisons on real data.
Commercialization of proton exchange membrane fuel cells for transportation applications
DOE Office of Scientific and Technical Information (OSTI.GOV)
Wismer, L.
1996-04-01
Environmental concerns with air quality and global warming have triggered strict federal ambient ozone air quality standards. Areas on non-attainment of these standards exist across the United States. Because it contains several of the most difficult attainment areas, the State of California has adopted low emission standards including a zero emission vehicle mandate that has given rise to development of hybrid electric vehicles, both battery-powered and fuel-cell powered. Fuel cell powered vehicles, using on-board hydrogen as a fuel, share the non-polluting advantage of the battery electric vehicle while offering at least three times the range today`s battery technology.
High power Yb:CALGO ultrafast regenerative amplifier for industrial application
NASA Astrophysics Data System (ADS)
Caracciolo, E.; Guandalini, A.; Pirzio, F.; Kemnitzer, M.; Kienle, F.; Agnesi, A.; Aus der Au, J.
2017-02-01
We present a high-power, single-crystal based, Yb:CALGO regenerative amplifier. The system delivers more than 50 W output power in continuous-wave regime, with diffraction limited beam quality. In Q-switching regime the spectrum is centered at 1043 nm and is 11 nm wide. In regenerative amplification experiments we achieved 34 W at 500 kHz with 12.7 nm FWHM wide spectra centered at 1044 nm seeding with a broadly tunable, single-prism SESAM mode-locked Yb:CALGO laser providing 9 nm wide spectra at 1049 nm. Pulse duration after compression was 140 fs, with excellent beam quality (M2 < 1.25).
Power analysis on the time effect for the longitudinal Rasch model.
Feddag, M L; Blanchin, M; Hardouin, J B; Sebille, V
2014-01-01
Statistics literature in the social, behavioral, and biomedical sciences typically stress the importance of power analysis. Patient Reported Outcomes (PRO) such as quality of life and other perceived health measures (pain, fatigue, stress,...) are increasingly used as important health outcomes in clinical trials or in epidemiological studies. They cannot be directly observed nor measured as other clinical or biological data and they are often collected through questionnaires with binary or polytomous items. The Rasch model is the well known model in the item response theory (IRT) for binary data. The article proposes an approach to evaluate the statistical power of the time effect for the longitudinal Rasch model with two time points. The performance of this method is compared to the one obtained by simulation study. Finally, the proposed approach is illustrated on one subscale of the SF-36 questionnaire.
10 CFR 50.54 - Conditions of licenses.
Code of Federal Regulations, 2014 CFR
2014-01-01
... chapter. (a)(1) Each nuclear power plant or fuel reprocessing plant licensee subject to the quality... irradiated fuel. (ff) For licensees of nuclear power plants that have implemented the earthquake engineering... of rated thermal power only if the Commission finds that the state of onsite emergency preparedness...