WorldWideScience

Sample records for voltage environmental applications

  1. Environmental and biotechnological applications of high-voltage pulsed discharges in water

    Energy Technology Data Exchange (ETDEWEB)

    Sato, Masayuki [Department of Chemical and Environmental Engineering, Gunma University 1-5-1 Tenjin, Kiryu, Gunma 376-8515 (Japan)], E-mail: mxsato@cee.gunma-u.ac.jp

    2008-05-01

    A high-voltage pulse has wide application in fields such as chemistry, physics and biology and their combinations. The high-voltage pulse forms two kinds of physical processes in water, namely (a) a pulsed electric field (PEF) in the parallel electrode configuration and (b) plasma generation by a pulsed discharge in the water phase with a concentrated electric field. The PEF can be used for inactivation of bacteria in liquid foods as a non-thermal process, and the underwater plasma is applicable not only for the decomposition of organic materials in water but also for biological treatment of wastewater. These discharge states are controlled mainly by the applied pulse voltage and the electrode shape. Some examples of environmental and biotechnological applications of a high-voltage pulse are reviewed.

  2. HIGH VOLTAGE ENVIRONMENTAL APPLICATIONS, INC.ELECTRON BEAM TECHNOLOGY - INNOVATIVE TECHNOLOGY EVALUATION REPORT

    Science.gov (United States)

    This report evaluates a high-voltage electron beam (E-beam) technology's ability to destroy volatile organic compounds (VOCs) and other contaminants present in liquid wastes. Specifically, this report discusses performance and economic data from a Superfund Innovative Technology...

  3. Voltage controlled spintronics device for logic applications.

    Energy Technology Data Exchange (ETDEWEB)

    Bader, S. D.; You, C.-Y.

    1999-09-03

    We consider logic device concepts based on our previously proposed spintronics device element whose magnetization orientation is controlled by application of a bias voltage instead of a magnetic field. The basic building block is the voltage-controlled rotation (VCR) element that consists of a four-layer structure--two ferromagnetic layers separated by both nanometer-thick insulator and metallic spacer layers. The interlayer exchange coupling between the two ferromagnetic layers oscillates as a function of applied voltage. We illustrate transistor-like concepts and re-programmable logic gates based on VCR elements.

  4. High voltage pulse generator. [Patent application

    Science.gov (United States)

    Fasching, G.E.

    1975-06-12

    An improved high-voltage pulse generator is described which is especially useful in ultrasonic testing of rock core samples. An N number of capacitors are charged in parallel to V volts and at the proper instance are coupled in series to produce a high-voltage pulse of N times V volts. Rapid switching of the capacitors from the paralleled charging configuration to the series discharging configuration is accomplished by using silicon-controlled rectifiers which are chain self-triggered following the initial triggering of the first rectifier connected between the first and second capacitors. A timing and triggering circuit is provided to properly synchronize triggering pulses to the first SCR at a time when the charging voltage is not being applied to the parallel-connected charging capacitors. The output voltage can be readily increased by adding additional charging networks. The circuit allows the peak level of the output to be easily varied over a wide range by using a variable autotransformer in the charging circuit.

  5. Improved Phasor Estimation Method for Dynamic Voltage Restorer Applications

    DEFF Research Database (Denmark)

    Ebrahimzadeh, Esmaeil; Farhangi, Shahrokh; Iman-Eini, Hossein;

    2015-01-01

    The dynamic voltage restorer (DVR) is a series compensator for distribution system applications, which protects sensitive loads against voltage sags by fast voltage injection. The DVR must estimate the magnitude and phase of the measured voltages to achieve the desired performance. This paper...... proposes a phasor parameter estimation algorithm based on a recursive variable and fixed data window least error squares (LES) method for the DVR control system. The proposed algorithm, in addition to decreasing the computational burden, improves the frequency response of the control scheme based...... on the fixed data window LES method. The DVR control system based on the proposed algorithm provides a better compromise between the estimation speed and accuracy of the voltage and current signals and can be implemented using a simple and low-cost processor. The results of the studies indicate...

  6. High Efficiency Power Converter for Low Voltage High Power Applications

    DEFF Research Database (Denmark)

    Nymand, Morten

    , and remote power generation for light towers, camper vans, boats, beacons, and buoys etc. A review of current state-of-the-art is presented. The best performing converters achieve moderately high peak efficiencies at high input voltage and medium power level. However, system dimensioning and cost are often......The topic of this thesis is the design of high efficiency power electronic dc-to-dc converters for high-power, low-input-voltage to high-output-voltage applications. These converters are increasingly required for emerging sustainable energy systems such as fuel cell, battery or photo voltaic based...... determined by the performance at the system worst case operating point which is usually at minimum input voltage and maximum power. Except for the non-regulating V6 converters, all published solutions exhibit a very significant drop in conversion efficiency at minimum input voltage and maximum output power...

  7. Enhanced current and voltage regulators for stand-alone applications

    DEFF Research Database (Denmark)

    Federico, de Bosio; Pastorelli, Michele; Antonio DeSouza Ribeiro, Luiz

    2016-01-01

    State feedback decoupling permits to achieve a better dynamic response for Voltage Source in stand-alone applications. The design of current and voltage regulators is performed in the discrete-time domain since it provides better accuracy and allows direct pole placement. As the attainable...... bandwidth of the current loop is mainly limited by computational and PWM delays, a lead compensator structure is proposed to overcome this limitation. The design of the voltage regulator is based on the Nyquist criterion, verifying to guarantee a high sensitivity peak. Discrete-time domain implementation...

  8. Environmental justice: a contrary finding for the case of high-voltage electric power transmission lines.

    Science.gov (United States)

    Wartenberg, Daniel; Greenberg, Michael R; Harris, Gerald

    2010-05-01

    Environmental justice is the consideration of whether minority and/or lower-income residents in a geographic area are likely to have disproportionately higher exposures to environmental toxins than those living elsewhere. Such situations have been identified for a variety of factors, such as air pollution, hazardous waste, water quality, noise, residential crowding, and housing quality. This study investigates the application of this concept to high-voltage electric power transmission lines (HVTL), which some perceive as a health risk because of the magnetic fields they generate, and also as esthetically unpleasing. We mapped all 345 kV and higher voltage HVTL in New York State and extracted and summarized proximate US Census sociodemographic and housing characteristic data into four categories on the basis of distances from HVTL. Contrary to our expectation, people living within 2000 ft from HVTL were more likely to be exposed to magnetic fields, white, of higher income, more educated and home owners, than those living farther away, particularly in urban areas. Possible explanations for these patterns include the desire for the open space created by the rights-of-way, the preference for new homes/subdivisions that are often located near HVTL, and moving closer to HVTL before EMFs were considered a risk. This study suggests that environmental justice may not apply to all environmental risk factors and that one must be cautious in generalizing. In addition, it shows the utility of geographical information system methodology for summarizing information from extremely large populations, often a challenge in epidemiology.

  9. Treatment of emulsified oils by electrocoagulation: pulsed voltage applications.

    Science.gov (United States)

    Genc, Ayten; Bakirci, Busra

    2015-01-01

    The effect of pulsed voltage application on energy consumption during electrocoagulation was investigated. Three voltage profiles having the same arithmetic average with respect to time were applied to the electrodes. The specific energy consumption for these profiles were evaluated and analyzed together with oil removal efficiencies. The effects of applied voltages, electrode materials, electrode configurations, and pH on oil removal efficiency were determined. Electrocoagulation experiments were performed by using synthetic and real wastewater samples. The pulsed voltages saved energy during the electrocoagulation process. In continuous operation, energy saving was as high as 48%. Aluminum electrodes used for the treatment of emulsified oils resulted in higher oil removal efficiencies in comparison with stainless steel and iron electrodes. When the electrodes gap was less than 1 cm, higher oil removal efficiencies were obtained. The highest oil removal efficiencies were 95% and 35% for the batch and continuous operating modes, respectively.

  10. High Voltage Applications of Explosively Formed Fuses

    Science.gov (United States)

    Tasker, D. G.; Goforth, J. H.; Fowler, C. M.; Herrera, D. H.; King, J. C.; Lopez, E. A.; Martinez, E. C.; Oona, H.; Marsh, S. P.; Reinovsky, R. E.; Stokes, J.; Tabaka, L. J.; Torres, D. T.; Sena, F. C.; Kiuttu, G.; Degnan, J.

    2004-11-01

    At Los Alamos, we have primarily applied Explosively Formed Fuse (EFF) techniques to high current systems. In these systems, the EFF has interrupted currents from 19-25 MA, thus diverting the current to low inductance loads. The transferred current magnitude is determined by the ratio of storage inductance to load inductance and, with dynamic loads, the current has ranged from 12-20 MA. In a system with 18 MJ stored energy, the switch operates at a power of up to 6 TW. We are now investigating the use of the EFF technique to apply high voltages to high impedance loads in systems that are more compact. In these systems we are exploring circuits with EFF lengths from 43-100 cm, which have storage inductances large enough to apply 300-500 kV across high impedance loads. Experimental results and design considerations are presented. Using cylindrical EFF switches of 10 cm diameter and 43 cm length, currents of approximately 3 MA were interrupted producing ~200 kV. This indicates the switch had an effective resistance of ~100 mΩ where 150-200 mΩ was expected. To understand the lower performance, several parameters were studied including electrical conduction through the explosive products; current density; explosive initiation; insulator type and conductor thickness. The results show a number of interesting features, most notably that the primary mechanism of switch operation is mechanical and not electrical fusing of the conductor. Switches opening on a 1-10 μs time scale with resistances starting at 50 μΩ and increasing to perhaps 1 Ω now seem possible to construct using explosive charges as small as a few pounds.

  11. Electric Voltage Control as an Implementation of Neural Network Applications

    Directory of Open Access Journals (Sweden)

    A. A. Al-Rababah

    2008-01-01

    Full Text Available Present study was proposed the monitoring of mathematical model of electric voltage source with using neural network for application in control systems as sensor and command signal. The monitoring system, consist of toroidal choke or transformer with high saturated ferromagnetic cores. The input information we receive from current periodic curves. The current was distributed into Fourier or walsh series. The combination of these harmonics and their amplitude values determine monitoring voltage value directly. For increase of this system precision, the mathematical model was constructed on basis of partial differential quasi-stationary electromagnetic field equations and ordi-nary differential electromagnetic circuit equations combination.

  12. Application of SMES in wind farm to improve voltage stability

    Science.gov (United States)

    Shi, J.; Tang, Y. J.; Ren, L.; Li, J. D.; Chen, S. J.

    2008-09-01

    For the wind farms introducing doubly fed induction generators (DFIGs), voltage stability is an essential issue which influences their widely integration into the power grid. This paper proposes the application of superconducting magnetic energy storage (SMES) in the power system integrated with wind farms. SMES can control the active and reactive power flow, realizing the operation in four quadrants independently. The introducing of SMES can smooth the output power flow of the wind farms, and supply dynamic voltage support. Using MATLAB/SIMULINK, the models of the DFIG, the power grid connected and the SMES are created. Simulation results show that the voltage stability of the power system integrated with wind farms can be improved considerably.

  13. Low voltage drop plasma switch for inverter and modulator applications

    Science.gov (United States)

    Goebel, D. M.; Poeschel, R. L.; Schumacher, R. W.

    1993-08-01

    A low forward voltage drop plasma switch has been developed for high-efficiency inverter and modulator applications. The switch, called the HOLLOTRON, is based on a grid-controlled, thermionic hollow-cathode discharge. A low forward voltage drop (10-20 V) is achieved by operating the hollow-cathode discharge in a static gas pressure of xenon. The dense plasma generated in the Ba-oxide dispenser hollow cathode is spread over a relatively large control grid area by a diverging magnetic field superimposed on the discharge. Interruption of the discharge current at high current densities (≳4 A/cm2) over the grid area is achieved by biasing the control grid sufficiently negative with respect to the plasma. The HOLLOTRON switch has demonstrated voltage stand-off of up to 20 kV, switching times of ≤0.3 μs, and pulse repetition frequencies of 20 kHz at 50% duty.

  14. Environmental applications for biosurfactants.

    Science.gov (United States)

    Mulligan, Catherine N

    2005-01-01

    Biosurfactants are surfactants that are produced extracellularly or as part of the cell membrane by bacteria, yeasts and fungi. Examples include Pseudomonas aeruginosa which produces rhamnolipids, Candida (formerly Torulopsis) bombicola, one of the few yeasts to produce biosurfactants, which produces high yields of sophorolipids from vegetable oils and sugars and Bacillus subtilis which produces a lipopeptide called surfactin. This review includes environmental applications of these biosurfactants for soil and water treatment. Biosurfactant applications in the environmental industries are promising due to their biodegradability, low toxicity and effectiveness in enhancing biodegradation and solubilization of low solubility compounds. However, more information is needed to be able to predict and model their behaviour. Full scale tests will be required. The role of biosurfactants in natural attenuation processes has not been determined. Very little information is available concerning the influence of soil components on the remediation process with biosurfactants. As most of the research until now has been performed with rhamnolipids, other biosurfactants need to be investigated as they may have more promising properties.

  15. Environmental applications for biosurfactants

    Energy Technology Data Exchange (ETDEWEB)

    Mulligan, Catherine N. [Department Building, Civil and Environmental Engineering, Concordia University, 1455 de Maisonneuve Boulevard W., Montreal, Quebec, H3G 1M8 (Canada)]. E-mail: mulligan@civil.concordia.ca

    2005-01-01

    Biosurfactants are surfactants that are produced extracellularly or as part of the cell membrane by bacteria, yeasts and fungi. Examples include Pseudomonas aeruginosa which produces rhamnolipids, Candida (formerly Torulopsis) bombicola, one of the few yeasts to produce biosurfactants, which produces high yields of sophorolipids from vegetable oils and sugars and Bacillus subtilis which produces a lipopeptide called surfactin. This review includes environmental applications of these biosurfactants for soil and water treatment. Biosurfactant applications in the environmental industries are promising due to their biodegradability, low toxicity and effectiveness in enhancing biodegradation and solubilization of low solubility compounds. However, more information is needed to be able to predict and model their behaviour. Full scale tests will be required. The role of biosurfactants in natural attenuation processes has not been determined. Very little information is available concerning the influence of soil components on the remediation process with biosurfactants. As most of the research until now has been performed with rhamnolipids, other biosurfactants need to be investigated as they may have more promising properties. - More information is needed to be able to predict and model the behaviour of biosurfactants.

  16. Voltage biased Varistor-Transistor Hybrid Devices: Properties and Applications

    Directory of Open Access Journals (Sweden)

    Raghvendra K Pandey

    2015-08-01

    Full Text Available The paper describes the properties and potential applications of a novel hybrid varistor device originating from biased voltage induced modified nonlinear current-voltage (I-V characteristics. Single crystal of an oxide semiconductor in the family of iron-titanates with the chemical formula of Fe2TiO5 (pseudobrookite has been used as substrate for the varistor. The modifications of the varistor characteristics are achieved by superimposition of a bias voltage in the current path of the varistor. These altered I-V characteristics, when analyzed, reveal the existence of embedded transistors coexisting with the varistor. These transistors exhibit mutual conductance, signal amplification and electronic switching which are the defining signatures of a typical transistor. The tuned varistors also acquire the properties of signal amplification and mutual conductance which expand the range of applications for a varistor beyond its traditional use as circuit protector. Both tuned varistors and the embedded transistors have attributes which make them suitable for many applications in electronics including at high temperatures and for radiation dominated environments such as space.

  17. Environmental Applications of Nanotechnology

    Science.gov (United States)

    Keller, Arturo A.

    2014-07-01

    Engineered nanomaterials (ENMs) are currently used in many applications including agriculture (Gruère, 2012; Khot et al. 2012; Lopez-Moreno et al. 2010; Peralta-Videa et al. 2011; Zhao et al. 2012), aerogels (Bigall et al. 2009), aerospace (Baur and Silverman, 2007), automotive (Coelho et al. 2012; Presting and König, 2003; Salonitis et al. 2010), catalysts (Zhou et al. 2011), coatings, paints and pigments (Dhoke et al. 2009; Gopalakrishnan et al. 2011; Khanna, 2008), composites (Borchardt, 2003; Khanna and Bakshi, 2009; Petrov and Georgiev, 2012; Sahoo et al. 2010), construction (Lee et al. 2010), cosmetics (Musee, 2011; Sabitha et al. 2012; Singh and Nanda, 2012), electronics and optics (Alda et al. 2005; Avasthi et al. 2007; Song et al. 2012; Subramanian and Takhee, 2012), energy (Serrano et al. 2009), environmental remediation (Dionysiou 2004; Khin et al. 2012), filtration and purification (Dhakras, 2011; Savage and Diallo, 2005), food products (Blasco and Picó, 2011; Weiss et al. 2006), medical (Boisseau and Loubaton, 2011; Farokhzad and Langer, 2006), packaging (Silvestre et al. 2011), paper and board (Kharisov and Kharissova, 2010), plastics, security (Marín and Merkoçi, 2012), sensors (Ding et al. 2010; Duncan et al. 2012; Su et al. 2012; Tan et al. 2012), and textiles (Qian and Hinestroza, 2004; Wong et al. 2006), and research is underway on many new applications...

  18. A Low-Voltage CMOS Buffer for RF Applications Based on a Fully-Differential Voltage-Combiner

    OpenAIRE

    Abdollahvand, S.; Santos-Tavares, R.; Goes, João

    2013-01-01

    Part 20: Electronics: RF Applications; International audience; This paper presents a new CMOS buffer circuit topology for radio-frequency (RF) applications based on a fully-differential voltage-combiner circuit, capable of operating at low-voltage. The proposed circuit uses a combination of common-source (CS) and common-drain (CD) devices. The simulation results show good levels of linearity and bandwidth. To improve total harmonic distortion (THD) a source degeneration technique is used. The...

  19. A PC-controlled voltage pulse generator for electroanalytical applications

    Science.gov (United States)

    Heredia-López, Francisco J.; Góngora-Alfaro, José L.; Alvarez-Cervera, Fernando J.; Bata-García, José Luis

    1997-04-01

    We present the design of a voltage pulse generator controlled by an IBM or compatible AT Personal Computer (PC) capable of synthesizing some of the voltage pulse wave forms commonly used in electrochemical studies. The included signals are: differential pulse voltametry, differential normal pulse voltametry, and differential pulse amperometry. Additionally, a triangular wave form and a constant-voltage signal, used in the pretreatment of carbon fiber microelectrodes for neurochemical analysis, are also available. Operating the generator imposes a minimum of restrictions on the specification of the duration, amplitude, and type of wave shapes. Low-cost PC-based design allows for compatibility, portability, and versatility. The operating ranges of the wave form parameters for the three voltametric signals are: initial voltage, -0.9-+0.9 V; step amplitude, 0.1-900 mV; period, 6 ms-60 s; measuring pulse amplitude, 0.1-900 mV; measuring pulse duration, 2 ms-20 s; prepulse duration, 2 ms-20 s. In the electrode pretreatment mode, the operating ranges are: amplitude, 0-±5 V; duration, unlimited; frequency, 15-240 Hz. The generator uses its own time base for the generation of all signals, thereby rendering it independent of processor clock speed or power-line frequency. The results of the experimental evaluation indicate that the system is accurate within ±10% of the expected values, taking into account the errors associated with the signal synthesis and the digitizing process. The maximum achievable scan rate is 500 V/s, and the highest frequency for the triangular wave form is 240 Hz. Therefore, the pulse generator could be used for fast cyclic voltametry (FCV). FCV and other wave forms could be added through software modules, without any hardware changes. We conclude that the PC-based electrochemistry pulse generator represents an economical and flexible alternative for electroanalytical applications.

  20. Ozone Sensor for Application in Medium Voltage Switchboard

    Directory of Open Access Journals (Sweden)

    Letizia De Maria

    2009-01-01

    Full Text Available The application of a new spectroscopic type fiber sensor for ozone detection in electrical components of Medium Voltage (MV network is evaluated. The sensor layout is based on the use of an optical retroreflector, to improve the detection sensitivity, and it was especially designed for detecting in situ rapid changes of ozone concentration. Preliminary tests were performed in a typical MV switchboard. Artificial defects simulated predischarge phenomena arising during real operating conditions. Results are discussed by a comparison with data simultaneously acquired with a standard partial discharge system.

  1. Environmental applications of ultrasound

    Science.gov (United States)

    Oxley, James Dean

    The application of ultrasound to environmental problems relies on the process of acoustic cavitation: the formation, growth, and implosive collapse of bubbles in a liquid. The collapse of such bubbles creates hot spots with temperatures as high as 5000 K, pressures up to 800 atm, and cooling rates in excess of 1010K/s. This thesis describes the use of ultrasound for the dissolution of gas into water, an investigation the sonochemistry of ionic liquids, and the sonochemical preparation of nanostructured materials for the catalytic hydrodehalogenation of organic halides. A variety of ultrasonic methods and configurations were designed and tested for the dispersion and dissolution of O2 in water. Ultrasonic methods examined include 20 kHz Ti horns, 336 to 1.41 MHz transducers, specially designed ultrasonic gas dispersion cell including the hollow horn extensions, Ti frits, and a modified 20 kHz cup horn. Most methods increased the dispersion rate when compared to non-ultrasonic control runs. Room-temperature ionic liquids were examined for their potential application as green solvents for sonochemical reactions. The effects of ultrasound on room-temperature ionic liquids were investigated using butylmethyl imidazolium chloride (BuMeImCl), butylmethyl imidazolium tetrafluoroborate (BuMeImBF 4), and decylmethyl imidazolium tetraphenylborate. Gas-chromatography mass-spectrometry head-gas analysis and multibubble sonoluminescence were used to show that room-temperature ionic liquids decomposed in the presence of ultrasound. As previously reported, molybdenum carbonyl and tungsten carbonyl were decomposed sonochemically in hexadecane to form porous aggregates of 2--3 nm high surface area Mo2C and W2C particles. The activity of these materials was studied for the catalytic hydrodehalogenation of aliphatic and aromatic halocarbons at low temperatures (T = 200--300°C). Both catalysts were selective, active, and stable for all substrates tested. The HDH of substrates bearing

  2. Properties of Polymer Composites Used in High-Voltage Applications

    Directory of Open Access Journals (Sweden)

    Ilona Pleşa

    2016-04-01

    Full Text Available The present review article represents a comprehensive study on polymer micro/nanocomposites that are used in high-voltage applications. Particular focus is on the structure-property relationship of composite materials used in power engineering, by exploiting fundamental theory as well as numerical/analytical models and the influence of material design on electrical, mechanical and thermal properties. In addition to describing the scientific development of micro/nanocomposites electrical features desired in power engineering, the study is mainly focused on the electrical properties of insulating materials, particularly cross-linked polyethylene (XLPE and epoxy resins, unfilled and filled with different types of filler. Polymer micro/nanocomposites based on XLPE and epoxy resins are usually used as insulating systems for high-voltage applications, such as: cables, generators, motors, cast resin dry-type transformers, etc. Furthermore, this paper includes ample discussions regarding the advantages and disadvantages resulting in the electrical, mechanical and thermal properties by the addition of micro- and nanofillers into the base polymer. The study goals are to determine the impact of filler size, type and distribution of the particles into the polymer matrix on the electrical, mechanical and thermal properties of the polymer micro/nanocomposites compared to the neat polymer and traditionally materials used as insulation systems in high-voltage engineering. Properties such as electrical conductivity, relative permittivity, dielectric losses, partial discharges, erosion resistance, space charge behavior, electric breakdown, tracking and electrical tree resistance, thermal conductivity, tensile strength and modulus, elongation at break of micro- and nanocomposites based on epoxy resin and XLPE are analyzed. Finally, it was concluded that the use of polymer micro/nanocomposites in electrical engineering is very promising and further research work

  3. On the investigation of voltage controlled oscillator phase noise for IoT applications

    Directory of Open Access Journals (Sweden)

    Haddad F.

    2016-01-01

    Full Text Available Voltage controlled oscillator (VCO is one of the key elements in radio frequency (RF transceivers. A VCO working at 2.4 GHz and designed in CMOS technology is presented. It is suitable for low-cost and low-noise applications using wireless standards such as ZigBee, Bluetooth, Wi-Fi and WPAN (Wireless Personal Area Network. The noise characteristics of this RF VCO are investigated. Noise measurements, especially, phase noise are achieved under different environmental conditions.

  4. Toward the Optimal Configuration of Dynamic Voltage Scaling Points in Real-Time Applications

    Institute of Scientific and Technical Information of China (English)

    Hui-Zhan Yi; Xue-Jun Yang

    2006-01-01

    In real-time applications, compiler-directed dynamic voltage scaling (DVS) could reduce energy consumption efficiently, where compiler put voltage scaling points in the proper places, and the supply voltage and clock frequency were adjusted to the relationship between the reduced time and the reduced workload. This paper presents the optimal configuration of dynamic voltage scaling points without voltage scaling overhead, which minimizes energy consumption. The conclusion is proved theoretically. Finally, it is confirmed by simulations with equally-spaced voltage scaling configuration.

  5. Characteristics and Breakdown Behaviors of Polysilicon Resistors for High Voltage Applications

    Directory of Open Access Journals (Sweden)

    Xiao-Yu Tang

    2015-01-01

    Full Text Available With the rapid development of the power integrated circuit technology, polysilicon resistors have been widely used not only in traditional CMOS circuits, but also in the high voltage applications. However, there have been few detailed reports about the polysilicon resistors’ characteristics, like voltage and temperature coefficients and breakdown behaviors which are critical parameters of high voltage applications. In this study, we experimentally find that the resistance of the polysilicon resistor with a relatively low doping concentration shows negative voltage and temperature coefficients, while that of the polysilicon resistor with a high doping concentration has positive voltage and temperature coefficients. Moreover, from the experimental results of breakdown voltages of the polysilicon resistors, it could be deduced that the breakdown of polysilicon resistors is thermally rather than electrically induced. We also proposed to add an N-type well underneath the oxide to increase the breakdown voltage in the vertical direction when the substrate is P-type doped.

  6. Application of Distribution Power Electronic Transformer for Medium Voltage

    Directory of Open Access Journals (Sweden)

    Prashant Kumar

    2014-12-01

    Full Text Available In   this   paper   a   distribution   power electronic transformer (DPET for feeding critical loads is presented. The PE based transformer is a multi-port converter that can connect to medium voltage levels on the primary side. Bidirectional power flow is provided to the each module. The presented structure consists of three stages: an input stage, an isolation stage, and an output stage.  The input current is sinusoidal, and it converts the high AC input voltage to low DC voltages. The isolated DC/DC converters are then connected to the DC links and provide galvanic isolation between the HV and LV sides. Finally, a three-phase inverter generates the AC output with the desired amplitude and frequency. The proposed DPET is extremely modular and can be extended for different voltage and power levels. It performs typical functions and has advantages such as power factor correction, elimination of voltage sag and swell, and reduction of voltage flicker in load side. Also in comparison to conventional transformers, it has lower weight, lower volume and eliminates necessity for toxic dielectric coolants the DPET performance is verified in MATLAB simulation.

  7. A Four-Phase High Voltage Conversion Ratio Bidirectional DC-DC Converter for Battery Applications

    Directory of Open Access Journals (Sweden)

    Li-Kun Xue

    2015-06-01

    Full Text Available This study presents a four-phase interleaved high voltage conversion ratio bidirectional DC-DC converter circuit based on coupled inductors and switched capacitors, which can eliminate the defects of conventional high voltage conversion ratio bidirectional DC-DC converters in terms of high-voltage/current stress, less efficiency and low-power limitation. Parallel channels are used to reduce current stress at the low-voltage side and series connected switched capacitors are used to enlarge voltage conversion ratio, reduce voltage stress and achieve auto current sharing. This paper proposes the operation principle, feature analysis and optimization design considerations. On this basis the objectives of high voltage conversion ratio, low voltage/current stress, high power density, high efficiency and high-power applications can be achieved. Some experimental results based on a 500 W prototype converter (24 V to 48 V at low-voltage side, 400 V at high-voltage side are given to verify the theoretical analysis and the effectiveness of the proposed converter.

  8. High Efficiency Power Converter for Low Voltage High Power Applications

    DEFF Research Database (Denmark)

    Nymand, Morten

    , and remote power generation for light towers, camper vans, boats, beacons, and buoys etc. In chapter 2, a review of current state-of-the-art is presented. The best performing converters achieve moderately high peak efficiencies at high input voltage and medium power level. However, system dimensioning...

  9. Confocal MXRF in environmental applications

    Energy Technology Data Exchange (ETDEWEB)

    Fittschen, Ursula Elisabeth Adriane [University of Hamburg, Department of Chemistry, Hamburg (Germany); Falkenberg, Gerald [Deutsches Elektronen Synchrotron, Hamburg (Germany)

    2011-06-15

    In this review we highlight the performance of confocal micro X-ray fluorescence (CMXRF) for application in environmental science, citing contributions from recent studies (2008-2010). In CMXRF the use of focusing and collecting optics enables discrimination of the origin of fluorescence photons in three dimensions. It thereby enables simple and direct three dimensional imaging, and also the removal of unwanted signal contribution either from the depth of the sample or from its surface. By limiting the area of origin of fluorescence signal CMXRF can simplify quantitative approaches. (orig.)

  10. Intelligent distributed voltage control system for smart grid application

    Energy Technology Data Exchange (ETDEWEB)

    Sajadi, Amirhossein [Warsaw Univ. of Technology (Poland); Ariatabar, Mitra [RWTH Aachen Univ. (Germany)

    2012-07-01

    Increasing penetration of the renewable energy source (RES) units in distribution networks particularly due to nonlinear and unpredictable nature of renewable units brings up new challenges in different aspects of electricity network, which leads to more complex power systems. Multi-agent system is consisting of agents which are capable to perceive environment that they are located in and to reacts with each other by communication infrastructure in order to achieve overall goals. In this paper an approach to control the voltage based on in the power distribution system is proposed and discussed. Therefore, a multi-agent system has been integrated with artificial intelligence to come up with fuzzy multi-agent based system. The proposed control scheme is deployed to a smart distribution system consisting distribution generation units, modelled in MATLAB/Simulink, to evaluate its effectiveness. The simulation results show how proposed system can regulate voltage in smart distribution feeders. (orig.)

  11. Electrospun Fibers for Energy, Electronic, & Environmental Applications

    Science.gov (United States)

    Bedford, Nicholas M.

    Electrospinning is an established method for creating polymer and bio-polymer fibers of dimensions ranging from ˜10 nanometers to microns. The process typically involves applying a high voltage between a solution source (usually at the end of a capillary or syringe) and a substrate on which the nanofibers are deposited. The high electric field distorts the shape of the liquid droplet, creating a Taylor cone. Additional applied voltage ejects a liquid jet of the polymer solution in the Taylor cone toward the counter electrode. The formation of fibers is generated by the rapid electrostatic elongation and solvent evaporation of this viscoelastic jet, which typically generates an entangled non-woven mesh of fibers with a high surface area to volume ratio. Electrospinning is an attractive alternative to other processes for creating nano-scale fibers and high surface area to volume ratio surfaces due to its low start up cost, overall simplicity, wide range of processable materials, and the ability to generate a moderate amount of fibers in one step. It has also been demonstrated that coaxial electrospinning is possible, wherein the nanofiber has two distinct phases, one being the core and another being the sheath. This method is advantageous because properties of two materials can be combined into one fiber, while maintaining two distinct material phases. Materials that are inherently electrospinable could be made into fibers using this technique as well. The most common applications areas for electrospun fibers are in filtration and biomedical areas, with a comparatively small amount of work done in energy, environmental, and sensor applications. Furthermore, the use of biologically materials in electrospun fibers is an avenue of research that needs more exploration, given the unique properties these materials can exhibit. The research aim of this thesis is to explore the use of electrospun fibers for energy, electrical and environmental applications. For energy

  12. High Efficiency Interleaved Active Clamped Dc-Dc Converter with Fuel Cell for High Voltage Applications

    Directory of Open Access Journals (Sweden)

    Sona P

    2014-02-01

    Full Text Available A high efficiency interleaved ZVS active clamped current fed dc-dc converter is proposed in this paper specially used for fuel cell applications. As the fuel cell output is very low we are in need of a step up dc-dc converter. Here a current fed dc-dc converter is used. Two current fed dc-dc converters are interleaved by connecting their inputs in parallel and outputs in series. With this proposed methodology input current ripples in the fuel cell stacks can be reduced and a regulated output voltage ripples can be obtained. The active clamping circuit used in this model absorbs the turn off voltage spikes hence low voltage devices with low on state resistance can be used.Voltage doubler circuits will give double the output voltage than normal with smaller transformer turns ratio and flexibility. The proposed method is simulated in MATLAB for verifying the accuracy of the proposed design.

  13. A combined environmental straining specimen holder for high-voltage electron microscopy

    Energy Technology Data Exchange (ETDEWEB)

    Takahashi, Yoshimasa, E-mail: yoshim.takahashi@aist.go.jp [National Institute of Advanced Industrial Science and Technology (AIST), 744 Motooka, Nishi-ku, Fukuoka 819-0395 (Japan); Tanaka, Masaki; Higashida, Kenji [Department of Materials Science and Engineering, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka 819-0395 (Japan); Yasuda, Kazuhiro; Matsumura, Syo [Department of Applied Quantum Physics and Nuclear Engineering, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka 819-0395 (Japan); Noguchi, Hiroshi [Department of Mechanical Engineering, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka 819-0395 (Japan)

    2010-10-15

    A novel specimen holder that enables in situ observation of crack-tip deformation and/or fracture under a controlled environment is developed for a high-voltage electron microscope (HVEM). A window-type environmental cell (EC) that incorporates a uniaxial straining apparatus is built into a side-entry-type single-tilt specimen holder. The gas control in EC, straining apparatus design, limited field of view for crack-tip observation, and specimen preparation for the specimen holder are presented in detail. Experimental results successfully demonstrate that the developed specimen holder is quite useful for the dynamic observation of crack-tip deformation and/or fracture subjected to a hostile environment, such as hydrogen gas.

  14. Novel substrate trigger SCR-LDMOS stacking structure for high-voltage ESD protection application

    Institute of Scientific and Technical Information of China (English)

    马金荣; 乔明; 张波

    2015-01-01

    A novel substrate trigger semiconductor control rectifier-laterally diffused metal–oxide semiconductor (STSCR-LDMOS) stacked structure is proposed and simulated using the transimission line pulser (TLP) multiple-pulse simulation method in a 0.35-µm, 60-V biploar-CMOS-DMOS (BCD) process without additional masks. On account of a very low holding voltage, it is susceptible to latch-up-like danger for the semiconductor control rectifier-laterally diffused metal–oxide semiconductor (SCR-LDMOS) in high-voltage electro-static discharge (ESD) protection applications. Although the conventional stacking structure has achieved strong latch-up immunity by increasing holding voltage, excessive high trigger voltage does not meet requirements for an ESD protection device. The holding voltage of the proposed stacked structure is proportional to the stacking number, whereas the trigger voltage remains nearly the same. A high holding voltage of 30.6 V and trigger voltage of 75.4 V are achieved.

  15. A Novel Series Connected Batteries State of High Voltage Safety Monitor System for Electric Vehicle Application

    Directory of Open Access Journals (Sweden)

    Qiang Jiaxi

    2013-01-01

    Full Text Available Batteries, as the main or assistant power source of EV (Electric Vehicle, are usually connected in series with high voltage to improve the drivability and energy efficiency. Today, more and more batteries are connected in series with high voltage, if there is any fault in high voltage system (HVS, the consequence is serious and dangerous. Therefore, it is necessary to monitor the electric parameters of HVS to ensure the high voltage safety and protect personal safety. In this study, a high voltage safety monitor system is developed to solve this critical issue. Four key electric parameters including precharge, contact resistance, insulation resistance, and remaining capacity are monitored and analyzed based on the equivalent models presented in this study. The high voltage safety controller which integrates the equivalent models and control strategy is developed. By the help of hardware-in-loop system, the equivalent models integrated in the high voltage safety controller are validated, and the online electric parameters monitor strategy is analyzed and discussed. The test results indicate that the high voltage safety monitor system designed in this paper is suitable for EV application.

  16. Manufacturing challenges of optical current and voltage sensors for utility applications

    Energy Technology Data Exchange (ETDEWEB)

    Yakymyshyn, C.P. [Montana State Univ., Bozeman, MT (United States). Dept. of Electrical and Computer Engineering; Brubaker, M.A. [Los Alamos National Lab., NM (United States); Johnston, P.M. [Johnston (Paul M.), Raleigh, NC (United States); Reinbold, C. [ABB High Voltage Switchgear, Greensburg, PA (United States)

    1997-12-01

    Measurement of voltages and currents in power transmission and distribution systems are critical to the electric utility industry for both revenue metering and reliability. Nonconventional instrument transformers based on intensity modulation of optical signals have been reported in the literature for more than 20 years. Recently described devices using passive bulk optical sensor elements include the Electro-Optic Voltage Transducer (EOVT) and Magneto-Optic Current Transducer (MOCT). These technologies offer substantial advantages over conventional instrument transformers in accuracy, optical isolation bandwidth, environmental compatibility, weight and size. This paper describes design and manufacturing issues associated with the EOVT and the Optical Metering Unit (OMU) recently introduced by ABB with field installation results presented for prototype units in the 345 kV and 420 kV voltage classes. The OMU incorporates an EOVT and MOCT to monitor the voltage and current on power transmission lines using a single free-standing device.

  17. Manufacturing challenges of optical current and voltage sensors for utility applications

    Energy Technology Data Exchange (ETDEWEB)

    Yakymyshyn, C.P. [Montana State Univ., Bozeman, MT (United States). Dept. of Electrical and Computer Engineering; Brubaker, M.A. [Los Alamos National Lab., NM (United States); Johnston, P.M. [Johnston (Paul M.), Raleigh, NC (United States); Reinbold, C. [ABB High Voltage Switchgear, Greensburg, PA (United States)

    1997-12-01

    Measurement of voltages and currents in power transmission and distribution systems are critical to the electric utility industry for both revenue metering and reliability. Nonconventional instrument transformers based on intensity modulation of optical signals have been reported in the literature for more than 20 years. Recently described devices using passive bulk optical sensor elements include the Electro-Optic Voltage Transducer (EOVT) and Magneto-Optic Current Transducer (MOCT). These technologies offer substantial advantages over conventional instrument transformers in accuracy, optical isolation bandwidth, environmental compatibility, weight and size. This paper describes design and manufacturing issues associated with the EOVT and the Optical Metering Unit (OMU) recently introduced by ABB with field installation results presented for prototype units in the 345 kV and 420 kV voltage classes. The OMU incorporates an EOVT and MOCT to monitor the voltage and current on power transmission lines using a single free-standing device.

  18. New Simple CMOS Realization of Voltage Differencing Transconductance Amplifier and Its RF Filter Application

    Directory of Open Access Journals (Sweden)

    A. Yeşil

    2011-09-01

    Full Text Available The voltage differencing transconductance amplifier (VDTA is a recently introduced active element for analog signal processing. However, the realization of VDTA is not given by any author yet. In this work, a new and simple CMOS realization of VDTA is presented. The proposed block has two voltage inputs and two kinds of current output, so it is functional for voltage- and transconductance-mode operation. Furthermore, VDTA exhibits two different values of transconductance so that there is no need to external resistors for VDTA based applications which seems to be a good advantage for analog circuit designer. A CMOS implementation of VDTA and a voltage-mode VDTA based filter are proposed and simulated. An application example of fourth order flat-band band-pass amplifier is given and the performance of the circuit is demonstrated by comparing the theory and simulation.

  19. Propylene based systems for high voltage cable insulation applications

    Energy Technology Data Exchange (ETDEWEB)

    Hosier, I L; Vaughan, A S; Swingler, S G [ECS, University of Southampton, Highfield, Southampton, SO17 1BJ (United Kingdom); Cozzarini, L, E-mail: ILH@ecs.soton.ac.u [DMRN, University of Trieste, Via Valerio 6A, 34127 Trieste (Italy)

    2009-08-01

    Crosslinked polyethylene (XLPE) remains the material of choice for extruded high voltage cables, possessing excellent thermo-mechanical and electrical properties. However, it is not easily recyclable posing questions as to its long term sustainability. Whilst both polyethylene and polypropylene are widely recycled and provide excellent dielectric properties, polypropylene has significantly better mechanical integrity at high temperatures than polyethylene. However, while isotactic polypropylene is too stiff at room temperature for incorporation into a cable system, previous studies by the authors have indicated that this limitation can be overcome by using a propylene-ethylene copolymer. Whilst these previous studies considered unrelated systems, the current study aims to quantify the usefulness of a series of related random propylene-ethylene co-polymers and assesses their potential for replacing XLPE.

  20. Self-Healable Electrical Insulation for High Voltage Applications

    Science.gov (United States)

    Williams, Tiffany S.

    2017-01-01

    Polymeric aircraft electrical insulation normally degrades by partial discharge with increasing voltage, which causes excessive localized Joule heating in the material and ultimately leads to dielectric failure of the insulator through thermal breakdown. Developing self-healing insulation could be a viable option to mitigate permanent mechanical degradation, thus increasing the longevity of the insulation. Instead of relying on catalyst and monomer-filled microcapsules to crack, flow, and cure at the damaged sites described in well-published mechanisms, establishment of ionic crosslinks could allow for multiple healing events to occur with the added benefit of achieving full recovery strength under certain thermal environments. This could be possible if the operating temperature of the insulator is the same as or close to the temperature where ionic crosslinks are formed. Surlyn, a commercial material with ionic crosslinks, was investigated as a candidate self-healing insulator based off prior demonstrations of self-healing behavior. Thin films of varying thicknesses were investigated and the effects of thickness on the dielectric strength were evaluated and compared to representative polymer insulators. The effects of thermal conditioning on the recovery strength and healing were observed as a function of time following dielectric breakdown. Moisture absorption was also studied to determine if moisture absorption rates in Surlyn were lower than that of common polyimides.

  1. Preparation methodology and possible treatments for improved ceramics for high voltage vacuum applications

    CERN Document Server

    Tan, J

    1998-01-01

    The flashover characteristics of an insulator bridged high voltage vacuum gap can play an important role in the overall performance of a high voltage device, for example in the extreme environments of high energy particle accelerators. The detailed preparation of the insulators is, at present, governed by the commercial production methods and by standard bulk cleaning processes, which for a particular application may be far from optimum. The influence of the mechanical preparation, thermal history and particular cleaning technique have been investigated for commercially available alumina samples, with measurement of surface characteristics by scanning electron microscopy and laser diffraction, measurement of the secondary electron emission curve and analysis of the high voltage performance with the possibility of applied fields up to 200kV/cm. The results of the different measurements are discussed in the overall context of the problems encountered in the full sized high voltage devices, and suggestions are m...

  2. Voltage regulation and reactive power supply capability of distributed generation : applications in active distribution systems

    Energy Technology Data Exchange (ETDEWEB)

    Katiraei, F.; Yazdani, A.; Uluski, R. [Quanta Technology, New York, NY (United States); Vaziri, M. [Pacific Gas and Electric Co., San Fransisco, CA (United States)

    2009-07-01

    Problems regarding voltage regulation on distribution feeders arise when there is a large demand for reactive power. The addition of distributed generation changes the power flow and voltage profile of a power system. The current practice is to use distributed generation passively and perform voltage regulation as before. However, this may not function well with high distributed generation penetration. This presentation discussed voltage regulation and the reactive power supply capability of distributed generation. Several applications in active distribution systems were presented. Specifically, the presentation discussed distributed interconnection challenges; utility practices and limiting factors; and the real and reactive power capabilities of distributed generation. A case study was also presented. It was concluded that in order for distributed generation to actively participate in real and reactive power management of distribution systems, a change is needed in standards and utility guidelines, along with a better understanding of distributed generation technologies and controls. 1 tab., 11 figs.

  3. Environmental auditing: Theory and applications

    Science.gov (United States)

    Thompson, Dixon; Wilson, Melvin J.

    1994-07-01

    The environmental audit has become a regular part of corporate environmental management in Canada and is also gaining recognition in the public sector. A 1991 survey of 75 private sector companies across Canada revealed that 76% (57/75) had established environmental auditing programs. A similar survey of 19 federal, provincial, and municipal government departments revealed that 11% (2/19) had established such programs. The information gained from environmental audits can be used to facilitate and enhance environmental management from the single facility level to the national and international levels. This paper is divided into two sections: section one examines environmental audits at the facility/company level and discusses environmental audit characteristics, trends, and driving forces not commonly found in the available literature. Important conclusions are: that wherever possible, an action plan to correct the identified problems should be an integral part of an audit, and therefore there should be a close working relationship between auditors, managers, and employees, and that the first audits will generally be more difficult, time consuming, and expensive than subsequent audits. Section two looks at environmental audits in the broader context and discusses the relationship between environmental audits and three other environmental information gathering/analysis tools: environmental impact assessments, state of the environment reports, and new systems of national accounts. The argument is made that the information collected by environmental audits and environmental impact assessments at the facility/company level can be used as the bases for regional and national state of the environment reports and new systems of national accounts.

  4. On the reliability of voltage and power as input parameters for the characterization of high power ultrasound applications

    Science.gov (United States)

    Haller, Julian; Wilkens, Volker

    2012-11-01

    For power levels up to 200 W and sonication times up to 60 s, the electrical power, the voltage and the electrical impedance (more exactly: the ratio of RMS voltage and RMS current) have been measured for a piezocomposite high intensity therapeutic ultrasound (HITU) transducer with integrated matching network, two piezoceramic HITU transducers with external matching networks and for a passive dummy 50 Ω load. The electrical power and the voltage were measured during high power application with an inline power meter and an RMS voltage meter, respectively, and the complex electrical impedance was indirectly measured with a current probe, a 100:1 voltage probe and a digital scope. The results clearly show that the input RMS voltage and the input RMS power change unequally during the application. Hence, the indication of only the electrical input power or only the voltage as the input parameter may not be sufficient for reliable characterizations of ultrasound transducers for high power applications in some cases.

  5. DEMONSTRATION BULLETIN: HIGH VOLTAGE ELECTRON BEAM TECHNOLOGY - HIGH VOLTAGE ENVIRONMENTAL APPLICATIONS, INC.

    Science.gov (United States)

    The high energy electron beam irradiation technology is a low temperature method for destroying complex mixtures of hazardous organic chemicals in solutions containing solids. The system consists of a computer-automated, portable electron beam accelerator and a delivery system. T...

  6. Evaluation of high temperature dielectric films for high voltage power electronic applications

    Science.gov (United States)

    Suthar, J. L.; Laghari, J. R.

    1992-01-01

    Three high temperature films, polyimide, Teflon perfluoroalkoxy and poly-P-xylene, were evaluated for possible use in high voltage power electronic applications, such as in high energy density capacitors, cables and microelectronic circuits. The dielectric properties, including permittivity and dielectric loss, were obtained in the frequency range of 50 Hz to 100 kHz at temperatures up to 200 C. The dielectric strengths at 60 Hz were determined as a function of temperature to 250 C. Confocal laser microscopy was performed to diagnose for voids and microimperfections within the film structure. The results obtained indicate that all films evaluated are capable of maintaining their high voltage properties, with minimal degradation, at temperatures up to 200 C. However, above 200 C, they lose some of their electrical properties. These films may therefore become viable candidates for high voltage power electronic applications at high temperatures.

  7. A Smart Voltage and Current Monitoring System for Three Phase Inverters Using an Android Smartphone Application

    Science.gov (United States)

    Mnati, Mohannad Jabbar; Van den Bossche, Alex; Chisab, Raad Farhood

    2017-01-01

    In this paper, a new smart voltage and current monitoring system (SVCMS) technique is proposed. It monitors a three phase electrical system using an Arduino platform as a microcontroller to read the voltage and current from sensors and then wirelessly send the measured data to monitor the results using a new Android application. The integrated SVCMS design uses an Arduino Nano V3.0 as the microcontroller to measure the results from three voltage and three current sensors and then send this data, after calculation, to the Android smartphone device of an end user using Bluetooth HC-05. The Arduino Nano V3.0 controller and Bluetooth HC-05 are a cheap microcontroller and wireless device, respectively. The new Android smartphone application that monitors the voltage and current measurements uses the open source MIT App Inventor 2 software. It allows for monitoring some elementary fundamental voltage power quality properties. An effort has been made to investigate what is possible using available off-the-shelf components and open source software. PMID:28420132

  8. A Smart Voltage and Current Monitoring System for Three Phase Inverters Using an Android Smartphone Application.

    Science.gov (United States)

    Mnati, Mohannad Jabbar; Van den Bossche, Alex; Chisab, Raad Farhood

    2017-04-15

    In this paper, a new smart voltage and current monitoring system (SVCMS) technique is proposed. It monitors a three phase electrical system using an Arduino platform as a microcontroller to read the voltage and current from sensors and then wirelessly send the measured data to monitor the results using a new Android application. The integrated SVCMS design uses an Arduino Nano V3.0 as the microcontroller to measure the results from three voltage and three current sensors and then send this data, after calculation, to the Android smartphone device of an end user using Bluetooth HC-05. The Arduino Nano V3.0 controller and Bluetooth HC-05 are a cheap microcontroller and wireless device, respectively. The new Android smartphone application that monitors the voltage and current measurements uses the open source MIT App Inventor 2 software. It allows for monitoring some elementary fundamental voltage power quality properties. An effort has been made to investigate what is possible using available off-the-shelf components and open source software.

  9. Design and Implementation of a High-Voltage Generator with Output Voltage Control for Vehicle ER Shock-Absorber Applications

    Directory of Open Access Journals (Sweden)

    Chih-Lung Shen

    2013-01-01

    Full Text Available A self-oscillating high-voltage generator is proposed to supply voltage for a suspension system in order to control the damping force of an electrorheological (ER fluid shock absorber. By controlling the output voltage level of the generator, the damping force in the ER fluid shock absorber can be adjusted immediately. The shock absorber is part of the suspension system. The high-voltage generator drives a power transistor based on self-excited oscillation, which converts dc to ac. A high-frequency transformer with high turns ratio is used to increase the voltage. In addition, the system uses the car battery as dc power supply. By regulating the duty cycle of the main switch in the buck converter, the output voltage of the buck converter can be linearly adjusted so as to obtain a specific high voltage for ER. The driving system is self-excited; that is, no additional external driving circuit is required. Thus, it reduces cost and simplifies system structure. A prototype version of the actual product is studied to measure and evaluate the key waveforms. The feasibility of the proposed system is verified based on experimental results.

  10. Degradation of High Voltage Polymeric Insulators in Arid Desert's Simulated Environmental Conditions

    Directory of Open Access Journals (Sweden)

    Yasin Khan

    2009-01-01

    Full Text Available Problem statement: High Voltage (HV polymeric insulators are replacing ceramic insulator commonly used for HV outdoor networks due to their ease of handling, reliability and cost. However, their long term performance and reliability are major concerns to power utilities. Approach: To investigate their performance in arid desert's conditions, two types of HV composite insulators were aged as per International Electrochemical Commission (IEC standard-61109. Additional test samples were subjected to accelerated aging conditions simulating the actual Ultraviolet (UV radiation intensity and temperature in the inland desert. Results: This study described the experimental results of the effects of thermo electric stress and UV radiations on the polymeric insulators aged under two conditions i.e., as per IEC standard and modified IEC standard that simulates the inland arid desert. The tests results after the artificial accelerated aging indicated that the dielectric response of thermoplastic insulators under the tested thermo-electric cum UV-irradiations outperforms Silicone rubber insulators.Conclusion: From the obtained results it will be easy to assess the performance and suitability of composite insulators for their applications in arid desert environments.

  11. The Applications of Current Comparators in the Measurements on High Voltage Insulation

    Directory of Open Access Journals (Sweden)

    Fei Yi-jun

    2016-01-01

    Full Text Available This paper describes the basic structure of the current comparator used for high voltage insulation measurements. Further applications for the current comparator in high voltage insulation are investigated and developed. A measuring system for the measurement of harmonics in the loss current of water tree aged insulation is described, as well as the principles to measure partial discharges with the current comparator bridge. A new system for the measurement of the DC component in the leakage current of insulation is de1veloped and presented. The results of experiments on XLPE cable insulation are also given.

  12. An improved GGNMOS triggered SCR for high holding voltage ESD protection applications

    Science.gov (United States)

    Zhang, Shuai; Dong, Shu-Rong; Wu, Xiao-Jing; Zeng, Jie; Zhong, Lei; Wu, Jian

    2015-10-01

    Developing an electrostatic discharge (ESD) protection device with a better latch-up immunity has been a challenging issue for the nanometer complementary metal-oxide semiconductor (CMOS) technology. In this work, an improved grounded-gate N-channel metal-oxide semiconductor (GGNMOS) transistor triggered silicon-controlled rectifier (SCR) structure, named GGSCR, is proposed for high holding voltage ESD protection applications. The GGSCR demonstrates a double snapback behavior as a result of progressive trigger-on of the GGNMOS and SCR. The double snapback makes the holding voltage increase from 3.43 V to 6.25 V as compared with the conventional low-voltage SCR. The TCAD simulations are carried out to verify the modes of operation of the device.

  13. An improved GGNMOS triggered SCR for high holding voltage ESD protection applications

    Institute of Scientific and Technical Information of China (English)

    张帅; 董树荣; 吴晓京; 曾杰; 钟雷; 吴健

    2015-01-01

    Developing an electrostatic discharge (ESD) protection device with a better latch-up immunity has been a challeng-ing issue for the nanometer complementary metal-oxide semiconductor (CMOS) technology. In this work, an improved grounded-gate N-channel metal-oxide semiconductor (GGNMOS) transistor triggered silicon-controlled rectifier (SCR) structure, named GGSCR, is proposed for high holding voltage ESD protection applications. The GGSCR demonstrates a double snapback behavior as a result of progressive trigger-on of the GGNMOS and SCR. The double snapback makes the holding voltage increase from 3.43 V to 6.25 V as compared with the conventional low-voltage SCR. The TCAD simulations are carried out to verify the modes of operation of the device.

  14. An ultra-low-voltage rectifier for PE energy harvesting applications

    Science.gov (United States)

    Jingmin, Wang; Zheng, Yang; Zhangming, Zhu; Yintang, Yang

    2016-02-01

    An ultra low voltage rectifier with high power conversion efficiency (PCE) for PE energy harvesting applications is presented in this paper. This is achieved by utilizing the DTMOS which the body terminal is connected to the gate terminal in a diode connected transistor. This implementation facilitates the rectifier with dynamic control over the threshold voltage. Moreover, we use input powered to take the place of output powered to reduce the power loss and thereby increasing the power conversion efficiency. Based on standard SMIC 0.18 μm CMOS technology, the simulation results show that the voltage conversion efficiency and the power conversion efficiency can reach up to 90.5% and 95.5% respectively, when the input voltage equals to 0.2 V @ 100 Hz with load resistance 50 kω. Input voltages with frequencies in the range of 10 Hz-1 kHz can be rectified. Project supported by the National Natural Science Foundation of China (Nos. 61234002, 61322405, 61306044, 61376033) and the National High-Tech Program of China (No. 2013AA014103).

  15. Environmental Response Management Application (ERMA) Gulf Response

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Environmental Response Management Application (ERMA) (R) is a web-based Geographic Information System (GIS) tool that assists both emergency responders and...

  16. A Voltage Controller in Photo-Voltaic System with Battery Storage for Stand-Alone Applications

    Directory of Open Access Journals (Sweden)

    Ganesh Dharmireddy

    2012-01-01

    Full Text Available This paper proposes the new voltage controller in photo-voltaic system for Stand-Alone Applications with battery energy storage. The output of the PV array is unregulated DC supply due to change in weather conditions. The maximum power is tracked with respect to temperature and irradiance levels by using DC-DC converter. The perturbation and observes algorithm is applied for maximum power point tracking (MPPT purpose. This algorithm is selected due to its ability to withstand against any parameter variation and having high efficiency. The solar cell array powers the steady state energy and the battery compensates the dynamic energy in the system. The aim of the control strategy is to control the SEPIC converter and bi-direction DC-DC converter to operate in suitable modes according to the condition of solar cell and battery, so as to coordinate the two sources of solar cell and battery supplying power and ensure the system operates with high efficiency and behaviors with good dynamic performance. The output of DC-DC converter is converted to AC voltage by using inverter.  The AC output voltage and frequency are regulated. A closed loop voltage control for inverter is done by using unipolar sine wave pulse width modulation (SPWM. The regulated AC voltage is fed to AC standalone loads or grid integration. The overall system is designed, developed and validated by using MATLAB-SIMULINK. The simulation results demonstrate the effective working of MPPT algorithm, control strategy and voltage controller with SPWM technique for inverter in AC standalone load applications.

  17. Applicable international environmental impact assessment laws for ...

    African Journals Online (AJOL)

    Lawrence Hart

    1971-05-28

    May 28, 1971 ... Technology. Review. Applicable international environmental impact assessment laws ... the relationship between environmental degradation/pollution and project developments. Though, there .... the convention on climate change and a statement of ..... Delta which states “Apart from air pollution from the oil.

  18. Technical Training Seminar: Low-Voltage Differential Signaling (LVDS): Technology and Applications

    CERN Multimedia

    Monique Duval

    2004-01-01

    Tuesday 26 October TECHNICAL TRAINING SEMINAR from 14:00 to 16:30, Auditorium 40-SS-C01 Low-Voltage Differential Signaling (LVDS): Technology and Applications Herbert Eisenring, Kai Peters / NATIONAL SEMICONDUCTOR (Europe) National Semiconductor pioneered the Low-Voltage Differential Signaling (LVDS) technology, and is a recognized leader in high speed differential products and design tools. National Semiconductor offers a wide range of innovative, affordable interconnect solutions including serializer-deserializers (SerDes), drivers-receivers-transceivers, crosspoint switches and clock drivers. LVDS is a new technology addressing the needs of todays high performance data transmission applications, and the LVDS standard is becoming the most popular differential data transmission standard in the industry. This Technical Training Seminar will present National Semiconductor existing and future products, and some applications relevant to the activities carried out at CERN. 14:00 - 14:15 Presentation of Nati...

  19. Technical Training Seminar: Low-Voltage Differential Signaling (LVDS): Technology and Applications

    CERN Multimedia

    Monique Duval

    2004-01-01

    Tuesday 26 October TECHNICAL TRAINING SEMINAR from 14:00 to 16:30, Auditorium 40-SS-C01 Low-Voltage Differential Signaling (LVDS): Technology and Applications Herbert Eisenring, Kai Peters / NATIONAL SEMICONDUCTOR (Europe) National Semiconductor pioneered the Low-Voltage Differential Signaling (LVDS) technology, and is a recognized leader in high speed differential products and design tools. National Semiconductor offers a wide range of innovative, affordable interconnect solutions including serializer-deserializers (SerDes), drivers-receivers-transceivers, crosspoint switches and clock drivers. LVDS is a new technology addressing the needs of todays high performance data transmission applications, and the LVDS standard is becoming the most popular differential data transmission standard in the industry. This Technical Training Seminar will present National Semiconductor existing and future products, and some applications relevant to the activities carried out at CERN. 14:00 - 14:15 Presentation of Nat...

  20. Application of active power sensitivity to frequency and voltage variations on load shedding

    Energy Technology Data Exchange (ETDEWEB)

    Girgis, Adly A. [Clemson University, 303 Riggs Hall, Clemson, SC 29634-0915 (United States); Mathure, Shruti [ITC Holdings, MI (United States)

    2010-03-15

    The occurrence of a large disturbance in a power system can lead to a decline in the system frequency and bus voltages due to a real and reactive power deficiency or due to the formation of islands with generation-load imbalance. Load shedding is an emergency control action that can prevent a blackout in the power system by relieving the overload in some parts of the system. This paper shows that rate of change of frequency can be utilized to determine the magnitude of generation-load imbalance, while the rate of change of voltage with respect to active power can be utilized to identify the sensitive bus for load shedding. The frequency, voltages and their rate of change can be obtained by means of measurements in real-time from various devices such as digital recorders or phasor measurement units or these parameters can be estimated from the voltage data by other means such as an optimal estimation method like Kalman filtering. The rate of change of system frequency, along with the equivalent system inertia may be used to estimate the magnitude of the disturbance prior to each load shedding step. The buses with a higher rate of change of voltage may be identified as the critical ones for load shedding and load can be first shed at these buses, depending on the change in the power flow at each bus. This application is tested on the IEEE 30 bus system and the preliminary results demonstrate that it is feasible to be used in load shedding to restore system voltage and frequency. (author)

  1. Electrospinning for advanced energy and environmental applications

    CERN Document Server

    Cavaliere, Sara

    2015-01-01

    Electrospinning for Advanced Energy and Environmental Applications delivers a state-of-the-art overview of the use of electrospun fibers in energy conversion and storage, as well as in environmental sensing and remediation. Featuring contributions from leading experts in electrospinning and its specific applications, this book: Introduces the electrospinning technique and its origins, outlining achievable one-dimensional (1D) nanoscaled materials and their various applicationsDiscusses the use of electrospun materials in energy devices, including low- and high-temperature fuel cells, hydrogen

  2. Design of interleaved multilayer rosen type piezoelectric transformer for high voltage dc/dc applications

    DEFF Research Database (Denmark)

    Rødgaard, Martin Schøler; Andersen, Thomas; Meyer, Kaspar Sinding

    2012-01-01

    Research and development within piezoelectric transformer (PT) based converters are rapidly increasing as the technology is maturing and starts to prove its capabilities. Especially for high voltage and high step-up applications, PT based converters have demonstrated good performance and DC....../AC converters are widely used commercially. The availability of PT based converters for DC/DC applications are very limited and are not that developed yet. I this paper an interleaved multi layer Rosen-type PT for high step-up and high output voltage is developed, for driving a 2.5kV dielectric electro active...... and obtain soft switching capabilities. This can be achieved by utilising an advantageous PT structure, which is the main advantage of the interleaved Rosen-type PT. Furthermore the design should be further optimised, in order to achieve soft switching capability. The goal of this paper is to develop a soft...

  3. Digital-circuit analysis of short-gate tunnel FETs for low-voltage applications

    Science.gov (United States)

    Zhuge, Jing; Verhulst, Anne S.; Vandenberghe, William G.; Dehaene, Wim; Huang, Ru; Wang, Yangyuan; Groeseneken, Guido

    2011-08-01

    This paper investigates the potential of tunnel field-effect transistors (TFETs), with emphasis on short-gate TFETs, by simulation for low-power digital applications having a supply voltage lower than 0.5 V. A transient study shows that the tunneling current has a negligible contribution in charging and discharging the gate capacitance of TFETs. In spite of a higher resistance region in the short-gate TFET, the gate (dis)charging speed still meets low-voltage application requirements. A circuit analysis is performed on short-gate TFETs with different materials, such as Si, Ge and heterostructures in terms of voltage overshoot, delay, static power, energy consumption and energy delay product (EDP). These results are compared to MOSFET and full-gate TFET performance. It is concluded that short-gate heterostructure TFETs (Ge-source for nTFET, In0.6Ga0.4As-source for pTFET) are promising candidates to extend the supply voltage to lower than 0.5 V because they combine the advantage of a low Miller capacitance, due to the short-gate structures, and strong drive current in TFETs, due to the narrow bandgap material in the source. At a supply voltage of 0.4 V and for an EOT and channel length of 0.6 nm and 40 nm, respectively, a three-stage inverter chain based on short-gate heterostructure TFETs saves 40% energy consumption per cycle at the same delay and shows 60%-75% improvement of EDP at the same static power, compared to its full-gate counterpart. When compared to the MOSFET, better EDP can be achieved in the heterostructure TFET especially at low static power consumption.

  4. Voltage-controlled oscillator at 6 GHz for Doppler radar in heart sensing applications

    Directory of Open Access Journals (Sweden)

    Jovanović Predrag

    2009-01-01

    Full Text Available In this paper, the design of a low noise voltage controlled oscillator (VCO for heart sensing applications is presented. It is designed using Ansoft Designer software to have a low level of phase noise, therefore a bipolar transistor is chosen. Many effects such as the behavior of large signals, the parasitic effects of packages, etc., are taken into account. Hence, through a nonlinear analysis, quite accurate simulation results are provided.

  5. Application of Newton's optimal power flow in voltage/reactive power control

    Energy Technology Data Exchange (ETDEWEB)

    Bjelogrlic, M.; Babic, B.S. (Electric Power Board of Serbia, Belgrade (YU)); Calovic, M.S. (Dept. of Electrical Engineering, University of Belgrade, Belgrade (YU)); Ristanovic, P. (Institute Nikola Tesla, Belgrade (YU))

    1990-11-01

    This paper considers an application of Newton's optimal power flow to the solution of the secondary voltage/reactive power control in transmission networks. An efficient computer program based on the latest achievements in the sparse matrix/vector techniques has been developed for this purpose. It is characterized by good robustness, accuracy and speed. A combined objective function appropriate for various system load levels with suitable constraints, for treatment of the power system security and economy is also proposed. For the real-time voltage/reactive power control, a suboptimal power flow procedure has been derived by using the reduced set of control variables. This procedure is based on the sensitivity theory applied to the determination of zones for the secondary voltage/reactive power control and corresponding reduced set of regulating sources, whose reactive outputs represent control variables in the optimal power flow program. As a result, the optimal power flow program output becomes a schedule to be used by operators in the process of the real-time voltage/reactive power control in both normal and emergency operating states.

  6. Optimal Design of DC to DC Boost Converter with Closed Loop Control PID Mechanism for High Voltage Photovoltaic Application

    Directory of Open Access Journals (Sweden)

    R. Arulmurugan

    2012-10-01

    Full Text Available This paper proposes a new dc to dc boost converter using closed loop control proportional Integral and Derivative mechanism for photovoltaic (PV standalone high voltage applications. The boost converter is composed of MOSFETs which are driven by closed loop PWM control. Many advantages including high efficiency, minimum number of switch, high voltage and power, low cost. This converter is attractive for high voltage and high power applications. The analysis and design considerations of the converter are presented. A prototype was implemented for an application requiring a 410W output power, input voltage range from 17.1-V, and a 317-V output voltage. The proposed system efficiency is about 90%.

  7. Optimal Design of DC to DC Boost Converter with Closed Loop Control PID Mechanism for High Voltage Photovoltaic Application

    Directory of Open Access Journals (Sweden)

    R. Arulmurugan

    2013-07-01

    Full Text Available This paper proposes a new dc to dc boost converter using closed loop control proportional Integral and Derivative mechanism for photovoltaic (PV standalone high voltage applications. The boost converter is composed of MOSFETs which are driven by closed loop PWM control. Many advantages including high efficiency, minimum number of switch, high voltage and power, low cost. This converter is attractive for high voltage and high power applications. The analysis and design considerations of the converter are presented. A prototype was implemented for an application requiring a 410W output power, input voltage range from 17.1-V, and a 317-V output voltage. The proposed system efficiency is about 90%.

  8. Environmental applications of graphene-based nanomaterials.

    Science.gov (United States)

    Perreault, François; Fonseca de Faria, Andreia; Elimelech, Menachem

    2015-08-21

    Graphene-based materials are gaining heightened attention as novel materials for environmental applications. The unique physicochemical properties of graphene, notably its exceptionally high surface area, electron mobility, thermal conductivity, and mechanical strength, can lead to novel or improved technologies to address the pressing global environmental challenges. This critical review assesses the recent developments in the use of graphene-based materials as sorbent or photocatalytic materials for environmental decontamination, as building blocks for next generation water treatment and desalination membranes, and as electrode materials for contaminant monitoring or removal. The most promising areas of research are highlighted, with a discussion of the main challenges that we need to overcome in order to fully realize the exceptional properties of graphene in environmental applications.

  9. The Application of Three-level Voltage Type High Voltage Frequency Conversion Technology in Ocean Engineering Ships%三电平电压型高压变频技术在海洋工程船的应用

    Institute of Scientific and Technical Information of China (English)

    宋艳琼

    2014-01-01

    节能减排、绿色环保,变频电力驱动技术是国内外船舶上应用的发展趋势.特别体现在海洋工程船的大型施工设备和施工设备的驱动系统上.阐述了变频电力驱动技术应用于海洋工程船的优点,介绍了三电平电压型高压变频技术的发展.对三电平电压型高压变频技术进行原理简述,给出了三电平空间电压矢量控制调速系统的主电路拓扑结构,分析了三电平空间电压矢量控制算法的实现,利用MATLAB 7.0/SIMULINK 6.0进行了三电平电压型高压变频调速系统的建模和仿真.%For the purpose of energy saving and emission reduction and green environmental protection , frequency conversion electric drive technology in the world is a development trend applied in ships .Especially this is embodied in large-scale construction equipment of ocean engineering ships and the drive system to construction equipment .This paper elaborates the advantages of variable frequency electric drive technology application in ocean engineering ships , and introduces the development of three-level voltage type high voltage frequency conversion technology.Also, the author illustrates the theories of three-level voltage type high voltage frequency conversion technology , and gives the main circuit topology structure of the three-level space voltage vector control speed regulation system , and analyzes the three-level space voltage vector control algorithm implementation , and finally builds a modeling and simulation of the three-level voltage type high voltage variable frequency speed regulation system by using MATLAB 7.0/SIMULINK 6.0 modules.

  10. Five-Phase Five-Level Open-Winding/Star-Winding Inverter Drive for Low-Voltage/High-Current Applications

    DEFF Research Database (Denmark)

    Padmanaban, Sanjeevi Kumar; Blaabjerg, Frede; Wheeler, Patrick

    2016-01-01

    This paper work proposed a five-phase five-level open-/star-winding multilevel AC converter suitable for low-voltage/high-current applications. Modular converter consists of classical two-level five-phase voltage source inverter (VSI) with slight reconfiguration to serve as a multilevel converter...

  11. Hierarchically Nanostructured Materials for Sustainable Environmental Applications

    Science.gov (United States)

    Ren, Zheng; Guo, Yanbing; Liu, Cai-Hong; Gao, Pu-Xian

    2013-11-01

    This article presents a comprehensive overview of the hierarchical nanostructured materials with either geometry or composition complexity in environmental applications. The hierarchical nanostructures offer advantages of high surface area, synergistic interactions and multiple functionalities towards water remediation, environmental gas sensing and monitoring as well as catalytic gas treatment. Recent advances in synthetic strategies for various hierarchical morphologies such as hollow spheres and urchin-shaped architectures have been reviewed. In addition to the chemical synthesis, the physical mechanisms associated with the materials design and device fabrication have been discussed for each specific application. The development and application of hierarchical complex perovskite oxide nanostructures have also been introduced in photocatalytic water remediation, gas sensing and catalytic converter. Hierarchical nanostructures will open up many possibilities for materials design and device fabrication in environmental chemistry and technology.

  12. Hierarchically nanostructured materials for sustainable environmental applications

    Science.gov (United States)

    Ren, Zheng; Guo, Yanbing; Liu, Cai-Hong; Gao, Pu-Xian

    2013-01-01

    This review presents a comprehensive overview of the hierarchical nanostructured materials with either geometry or composition complexity in environmental applications. The hierarchical nanostructures offer advantages of high surface area, synergistic interactions, and multiple functionalities toward water remediation, biosensing, environmental gas sensing and monitoring as well as catalytic gas treatment. Recent advances in synthetic strategies for various hierarchical morphologies such as hollow spheres and urchin-shaped architectures have been reviewed. In addition to the chemical synthesis, the physical mechanisms associated with the materials design and device fabrication have been discussed for each specific application. The development and application of hierarchical complex perovskite oxide nanostructures have also been introduced in photocatalytic water remediation, gas sensing, and catalytic converter. Hierarchical nanostructures will open up many possibilities for materials design and device fabrication in environmental chemistry and technology. PMID:24790946

  13. Hierarchically Nanostructured Materials for Sustainable Environmental Applications

    Directory of Open Access Journals (Sweden)

    Zheng eRen

    2013-11-01

    Full Text Available This article presents a comprehensive overview of the hierarchical nanostructured materials with either geometry or composition complexity in environmental applications. The hierarchical nanostructures offer advantages of high surface area, synergistic interactions and multiple functionalities towards water remediation, environmental gas sensing and monitoring as well as catalytic gas treatment. Recent advances in synthetic strategies for various hierarchical morphologies such as hollow spheres and urchin-shaped architectures have been reviewed. In addition to the chemical synthesis, the physical mechanisms associated with the materials design and device fabrication have been discussed for each specific application. The development and application of hierarchical complex perovskite oxide nanostructures have also been introduced in photocatalytic water remediation, gas sensing and catalytic converter. Hierarchical nanostructures will open up many possibilities for materials design and device fabrication in environmental chemistry and technology.

  14. A New Four States High Deflection Low Actuation Voltage Electrostatic Mems Switch for RF Applications

    CERN Document Server

    Robin, Renaud; Segueni, Karim; Millet, Olivier; Buchaillot, Lionel

    2008-01-01

    This paper presents a new electrostatic MEMS (MicroElectroMechanical System) based on a single high reliability totally free flexible membrane. Using four electrodes, this structure enables four states which allowed large deflections (4$\\mu$m) with low actuation voltage (7,5V). This design presents also a good contact force and improve the restoring force of the structure. As an example of application, a Single Pole Double Throw (SPDT) for 24GHz applications, based on this design, has been simulated.

  15. Environmental applications of gravity surveying

    Energy Technology Data Exchange (ETDEWEB)

    Barrows, L.J. (Illinois State Univ., Normal, IL (United States)); Nesbit, L.C. (KEMRON Environmental Services, Novi, MI (United States)); Khan, W.A. (Environmental Science Engineering, Phoenix, AZ (United States))

    1994-04-01

    The Allis Park Sanitary Landfill Company developed a new landfill near Onway, Michigan in an area which has glacial alluvium and glacial till overlying limestone. There are several solution karst features in the region and some critics had maintained that a new karst collapse could rupture the liner system and allow escape of leachate into the groundwater. The gravity survey was conducted to determine the extent of any karst development at the site. The first portion of the survey was two profiles over some karst features located about five miles southeast of the proposed landfill. These showed negative gravity anomalies. The survey of the proposed landfill site resulted in a 50 microGal contour map of the area and also showed a negative anomaly. This could be due to either elevation variations on the till to limestone bedrock surface or to karst development within the limestone. Because there was no evidence of historic development of new karst features in the region, the gravity anomaly was not further investigated. In another gravity survey, a large retail department store had been remodeled and extended over an area previously occupied by an auto service center. The removal of a waste oil storage tank (UST) had not been documented and the environmental consultant (KEMRON, Inc.) proposed that a gravity survey be used to find the tank location. This proposal was based on calculations of the gravity effects of a UST. The survey resulted in a four-microGal contour map which showed a couple of anomalies which could be due to a tank or a backfilled tank excavation. During the survey, a store employee identified the previous location of the tank and explained that she had personally witnessed its removal. Based on the employee's eye-witness account of the tank removal and the coincidence of her indicated tank location with one of the gravity anomalies the authors recommended the site be granted clean closure.

  16. Fully Integrated Ultra-Low Voltage Step-up Converter with Voltage Doubling LC-Tank for Energy Harvesting Applications

    Science.gov (United States)

    Jayaweera, H. M. P. C.; Pathirana, W. P. M. R.; Muhtaroğlu, Ali

    2015-12-01

    This paper reports the design, fabrication, and validation of a novel integrated interface circuit for ultra-low voltage step up converter in 0.18 μm CMOS technology. The circuit does not use off-chip components. Fully integrated centre-tap differential inductors are introduced in the proposed LC oscillator design to achieve 38% area reduction compared to the use of four separate inductors. The efficiency of the system is hence enhanced through the elimination of clock buffer circuits traditionally utilized to drive the step-up converter. The experimental results prove that the system can self-start, and step 0.25 V up to 1.7 V to supply a 46 μW load with 15.5% efficiency. The minimum validated input voltage is 0.15 V, which is boosted up to 1.2 V under open circuit conditions.

  17. A High-Efficiency Voltage Equalization Scheme for Supercapacitor Energy Storage System in Renewable Generation Applications

    Directory of Open Access Journals (Sweden)

    Liran Li

    2016-06-01

    Full Text Available Due to its fast charge and discharge rate, a supercapacitor-based energy storage system is especially suitable for power smoothing in renewable energy generation applications. Voltage equalization is essential for series-connected supercapacitors in an energy storage system, because it supports the system’s sustainability and maximizes the available cell energy. In this paper, we present a high-efficiency voltage equalization scheme for supercapacitor energy storage systems in renewable generation applications. We propose an improved isolated converter topology that uses a multi-winding transformer. An improved push-pull forward circuit is applied on the primary side of the transformer. A coupling inductor is added on the primary side to allow the switches to operate under the zero-voltage switching (ZVS condition, which reduces switching losses. The diodes in the rectifier are replaced with metal-oxide-semiconductor field-effect transistors (MOSFETs to reduce the power dissipation of the secondary side. In order to simplify the control, we designed a controllable rectifying circuit to achieve synchronous rectifying on the secondary side of the transformer. The experimental results verified the effectiveness of the proposed design.

  18. Model Based Optimization of Integrated Low Voltage DC-DC Converter for Energy Harvesting Applications

    Science.gov (United States)

    Jayaweera, H. M. P. C.; Muhtaroğlu, Ali

    2016-11-01

    A novel model based methodology is presented to determine optimal device parameters for the fully integrated ultra low voltage DC-DC converter for energy harvesting applications. The proposed model feasibly contributes to determine the maximum efficient number of charge pump stages to fulfill the voltage requirement of the energy harvester application. The proposed DC-DC converter based power consumption model enables the analytical derivation of the charge pump efficiency when utilized simultaneously with the known LC tank oscillator behavior under resonant conditions, and voltage step up characteristics of the cross-coupled charge pump topology. The verification of the model has been done using a circuit simulator. The optimized system through the established model achieves more than 40% maximum efficiency yielding 0.45 V output with single stage, 0.75 V output with two stages, and 0.9 V with three stages for 2.5 kΩ, 3.5 kΩ and 5 kΩ loads respectively using 0.2 V input.

  19. Two phase multiferroics for voltage-induced entropy change with application in near-room-temperature refrigeration

    Science.gov (United States)

    Giri, Prakash; Kumar, Dhananjay; Binek, Christian

    The demand for environmental friendly, cost-effective and energy efficient cooling drives the emerging technology of magnetic refrigeration at room temperature. We fabricate a two phase mutiferroic La0.7Sr0.3MnO3/Pb(Mg1/3Nb2/3) O3-PbTiO3(001) via pulsed laser deposition for application in advanced near room-temperature refrigeration and miniature cooling devices. The key innovation rests on utilizing the magnetocaloric effect in zero applied magnetic fields. The magnetocaloric effect of the composite is activated purely by electric field. We utilize strain originating from stress which is voltage-induced via the inverse piezoelectric effect of PMN-PT. The strain is carried over into the adjacent LSMO thin film thus changing its magnetic order. The voltage-induced variation in magnetization leads to change in isothermal entropy when the experiment is carried out in contact with a thermostat and gives correspondingly rise to an adiabatic temperature change when heat exchange is suppressed. This project is supported by NSF through Nebraska MRSEC DMR-1420645.

  20. Electronics drivers for high voltage dielectric electro active polymer (DEAP) applications

    DEFF Research Database (Denmark)

    Zhang, Zhe; Andersen, Michael A. E.

    2015-01-01

    magnetic and piezoelectric transformers are employed for the heating valve and incremental motor application, where only ON/OFF regulation is adopted fo r energy saving; as for DEAP based energy harvesting, the no - isolated Buck/Boost converter is used, due to the system high power capacity (above 100W......), but the voltage balancing across the series - connected high voltage IGBTs is a critical issue and accordi ngly a novel gate driver circuitry is proposed and equipped; due to the requirements of the audio products, such as low distortion and noise, the multi - level Buck converter based Class - D amplifier....... In this paper, electronics divers for heating valves, loud speakers, incremental motors, and energy harvesting are reviewed, studied and developed in accordance with their corresponding specifications. Due to the simplicity and low power capacity (below 10W), the reversible Fly - back converters with both...

  1. What is the Best Converter for Low Voltage Fuel Cell Applications- A Buck or Boost?

    DEFF Research Database (Denmark)

    Nymand, Morten; Tranberg, René; Madsen, Mark E.;

    2009-01-01

    Amongst many converter topologies that have been proposed and developed for low voltage fuel cell applications, isolated full-bridge Buck and Boost converters appear to be the most popular. Although the Buck topology is considered to be superior in performance, for particularly being more efficient....... Experimental results of two 1.5 kW prototype Buck and Boost converter units are presented with detailed discussions, and the paper explains why, in contrary to the popular belief, a properly designed Boost topology is superior in performance to Buck topology and more appropriate for low voltage fuel cell......, this claim has never been proved with a ‘proper’ comparison to the Boost topology. This paper presents a comprehensive comparison between Buck and Boost topologies, which are designed for the same specifications and tested under the same and stringent operating conditions using precision measuring equipment...

  2. A High Voltage Olivine Cathode for Application in Lithium-Ion Batteries.

    Science.gov (United States)

    Di Lecce, Daniele; Brescia, Rosaria; Scarpellini, Alice; Prato, Mirko; Hassoun, Jusef

    2016-01-01

    A new olivine composition (i.e., LiFe0.25 Mn0.5 Co0.25 PO4) is proposed as electrode material with increased energy density for application in lithium-ion batteries. The new formulation increases the working voltage and induces different electrochemical behavior with respect to bare olivine materials based on Fe. The study provides deep insight into the features of the Fe(3+) /Fe(2+), Mn(3+)/Mn(2+), and Co(3+)/Co(2+) redox couples within the olivine lattice in terms of electrochemical activity, Li(+) transport properties, and Li-cell behavior. The electrochemical characterization clearly reveals the voltage signatures corresponding to the various metals; however, the Mn(3+)/Mn(2+) process has higher intrinsic polarization with respect to Fe(3+)/Fe(2+) and Co(3+)/Co(2+). This issue is efficiently mitigated by carbon coating the material, resulting in enhanced electrochemical performances.

  3. What is the Best Converter for Low Voltage Fuel Cell Applications- A Buck or Boost?

    DEFF Research Database (Denmark)

    Nymand, Morten; Tranberg, René; Madsen, Mark E.

    2009-01-01

    Amongst many converter topologies that have been proposed and developed for low voltage fuel cell applications, isolated full-bridge Buck and Boost converters appear to be the most popular. Although the Buck topology is considered to be superior in performance, for particularly being more efficient......, this claim has never been proved with a ‘proper’ comparison to the Boost topology. This paper presents a comprehensive comparison between Buck and Boost topologies, which are designed for the same specifications and tested under the same and stringent operating conditions using precision measuring equipment....... Experimental results of two 1.5 kW prototype Buck and Boost converter units are presented with detailed discussions, and the paper explains why, in contrary to the popular belief, a properly designed Boost topology is superior in performance to Buck topology and more appropriate for low voltage fuel cell...

  4. Rad-Hard, Miniaturized, Scalable, High-Voltage Switching Module for Power Applications Rad-Hard, Miniaturized

    Science.gov (United States)

    Adell, Philippe C.; Mojarradi, Mohammad; DelCastillo, Linda Y.; Vo, Tuan A.

    2011-01-01

    A paper discusses the successful development of a miniaturized radiation hardened high-voltage switching module operating at 2.5 kV suitable for space application. The high-voltage architecture was designed, fabricated, and tested using a commercial process that uses a unique combination of 0.25 micrometer CMOS (complementary metal oxide semiconductor) transistors and high-voltage lateral DMOS (diffusion metal oxide semiconductor) device with high breakdown voltage (greater than 650 V). The high-voltage requirements are achieved by stacking a number of DMOS devices within one module, while two modules can be placed in series to achieve higher voltages. Besides the high-voltage requirements, a second generation prototype is currently being developed to provide improved switching capabilities (rise time and fall time for full range of target voltages and currents), the ability to scale the output voltage to a desired value with good accuracy (few percent) up to 10 kV, to cover a wide range of high-voltage applications. In addition, to ensure miniaturization, long life, and high reliability, the assemblies will require intensive high-voltage electrostatic modeling (optimized E-field distribution throughout the module) to complete the proposed packaging approach and test the applicability of using advanced materials in a space-like environment (temperature and pressure) to help prevent potential arcing and corona due to high field regions. Finally, a single-event effect evaluation would have to be performed and single-event mitigation methods implemented at the design and system level or developed to ensure complete radiation hardness of the module.

  5. Electronics drivers for high voltage dielectric electro active polymer (DEAP) applications

    Science.gov (United States)

    Zhang, Zhe; Andersen, Michael A. E.

    2015-04-01

    Dielectric electro active polymer (DEAP) can be used in actuation, sensing and energy harvesting applications, but driving the DEAP based actuators and generators has three main challenges from a power electronics standpoint, i.e. high voltage (around 2.5 kV), nonlinearity, and capacitive behavior. In this paper, electronics divers for heating valves, loud speakers, incremental motors, and energy harvesting are reviewed, studied and developed in accordance with their corresponding specifications. Due to the simplicity and low power capacity (below 10W), the reversible Fly-back converters with both magnetic and piezoelectric transformers are employed for the heating valve and incremental motor application, where only ON/OFF regulation is adopted for energy saving; as for DEAP based energy harvesting, the noisolated Buck/Boost converter is used, due to the system high power capacity (above 100W), but the voltage balancing across the series-connected high voltage IGBTs is a critical issue and accordingly a novel gate driver circuitry is proposed and equipped; due to the requirements of the audio products, such as low distortion and noise, the multi-level Buck converter based Class-D amplifier, because of its high control linearity, is implemented for the loud speaker applications. A synthesis among those converter topologies and control techniques is given; therefore, for those DEAP based applications, their diversity and similarity of electronics drivers, as well as the key technologies employed are analyzed. Therefore a whole picture of how to choose the proper topologies can be revealed. Finally, the design guidelines in order to achieve high efficiency and reliability are discussed.

  6. Electronic Noses for Environmental Monitoring Applications

    Directory of Open Access Journals (Sweden)

    Laura Capelli

    2014-10-01

    Full Text Available Electronic nose applications in environmental monitoring are nowadays of great interest, because of the instruments’ proven capability of recognizing and discriminating between a variety of different gases and odors using just a small number of sensors. Such applications in the environmental field include analysis of parameters relating to environmental quality, process control, and verification of efficiency of odor control systems. This article reviews the findings of recent scientific studies in this field, with particular focus on the abovementioned applications. In general, these studies prove that electronic noses are mostly suitable for the different applications reported, especially if the instruments are specifically developed and fine-tuned. As a general rule, literature studies also discuss the critical aspects connected with the different possible uses, as well as research regarding the development of effective solutions. However, currently the main limit to the diffusion of electronic noses as environmental monitoring tools is their complexity and the lack of specific regulation for their standardization, as their use entails a large number of degrees of freedom, regarding for instance the training and the data processing procedures.

  7. High Voltage EEE Parts for EMA/EHA Applications on Manned Launch Vehicles

    Science.gov (United States)

    Griffin, Trent; Young, David

    2011-01-01

    The objective of this paper is an assessment of high voltage electronic components required for high horsepower electric thrust vector control (TVC) systems for human spaceflight launch critical application. The scope consists of creating of a database of available Grade 1 electrical, electronic and electromechanical (EEE) parts suited to this application, a qualification path for potential non-Grade 1 EEE parts that could be used in these designs, and pathfinder testing to validate aspects of the proposed qualification plan. Advances in the state of the art in high power electric power systems enable high horsepower electric actuators, such as the electromechnical actuator (EMA) and the electro-hydrostatic actuator (EHA), to be used in launch vehicle TVC systems, dramaticly reducing weight, complexity and operating costs. Designs typically use high voltage insulated gate bipolar transistors (HV-IGBT). However, no Grade 1 HV-IGBT exists and it is unlikely that market factors alone will produce such high quality parts. Furthermore, the perception of risk, the lack of qualification methodoloy, the absence of manned space flight heritage and other barriers impede the adoption of commercial grade parts onto the critical path. The method of approach is to identify high voltage electronic component types and key parameters for parts currently used in high horsepower EMA/EHA applications, to search for higher quality substitutes and custom manufacturers, to create a database for these parts, and then to explore ways to qualify these parts for use in human spaceflight launch critical application, including grossly derating and possibly treating hybrid parts as modules. This effort is ongoing, but results thus far include identification of over 60 HV-IGBT from four manufacturers, including some with a high reliability process flow. Voltage ranges for HV-IGBT have been identified, as has screening tests used to characterize HV-IGBT. BSI BS ISO 21350 Space systems Off

  8. Analysis of a modular generator for high-voltage, high-frequency pulsed applications, using low voltage semiconductors (series connected step-up (1:10) transformers

    Science.gov (United States)

    Redondo, L. M.; Fernando Silva, J.; Margato, E.

    2007-03-01

    This article discusses the operation of a modular generator topology, which has been developed for high-frequency (kHz), high-voltage (kV) pulsed applications. The proposed generator uses individual modules, each one consisting of a pulse circuit based on a modified forward converter, which takes advantage of the required low duty cycle to operate with a low voltage clamp reset circuit for the step-up transformer. This reduces the maximum voltage on the semiconductor devices of both primary and secondary transformer sides. The secondary winding of each step-up transformer is series connected, delivering a fraction of the total voltage. Each individual pulsed module is supplied via an isolation transformer. The assembled modular laboratorial prototype, with three 5kV modules, 800V semiconductor switches, and 1:10 step-up transformers, has 80% efficiency, and is capable of delivering, into resistive loads, -15kV/1A pulses with 5μs width, 10kHz repetition rate, with less than 1μs pulse rise time. Experimental results for resistive loads are presented and discussed.

  9. Analysis of a modular generator for high-voltage, high-frequency pulsed applications, using low voltage semiconductors (series connected step-up (1:10) transformers.

    Science.gov (United States)

    Redondo, L M; Fernando Silva, J; Margato, E

    2007-03-01

    This article discusses the operation of a modular generator topology, which has been developed for high-frequency (kHz), high-voltage (kV) pulsed applications. The proposed generator uses individual modules, each one consisting of a pulse circuit based on a modified forward converter, which takes advantage of the required low duty cycle to operate with a low voltage clamp reset circuit for the step-up transformer. This reduces the maximum voltage on the semiconductor devices of both primary and secondary transformer sides. The secondary winding of each step-up transformer is series connected, delivering a fraction of the total voltage. Each individual pulsed module is supplied via an isolation transformer. The assembled modular laboratorial prototype, with three 5 kV modules, 800 V semiconductor switches, and 1:10 step-up transformers, has 80% efficiency, and is capable of delivering, into resistive loads, -15 kV1 A pulses with 5 micros width, 10 kHz repetition rate, with less than 1 micros pulse rise time. Experimental results for resistive loads are presented and discussed.

  10. Ultrastable Natural Ester-Based Nanofluids for High Voltage Insulation Applications.

    Science.gov (United States)

    Peppas, Georgios D; Bakandritsos, Aristides; Charalampakos, Vasilis P; Pyrgioti, Eleftheria C; Tucek, Jiri; Zboril, Radek; Gonos, Ioannis F

    2016-09-28

    Nanofluids for high voltage insulation systems have emerged as a potential substitute for liquid dielectrics in industrial applications. Nevertheless, the sedimentation of nanoparticles has been so far a serious barrier for their wide and effective exploitation. The present work reports on the development and in-depth characterization of colloidally ultrastable natural ester oil insulation systems containing iron oxide nanocrystals which lift the problem of sedimentation and phase separation. Compared to state-of-the-art systems, the final product is endowed with increased dielectric strength, faster thermal response, lower dielectric losses (decreased dissipation factor: tan δ), and very high endurance during discharge stressing. The developed nanofluid was studied and compared with a similar system containing commercial iron oxide nanoparticles, the latter demonstrating extensive sedimentation. Herein, the dielectric properties of the nanofluids are analyzed at various concentrations by means of breakdown voltage and dissipation factor measurements. The characterization techniques unequivocally demonstrate the high performance reliability of the reported nanofluid, which constitutes a significant breakthrough in the field of high voltage insulation technologies.

  11. Threshold-voltage modulated phase change heterojunction for application of high density memory

    Energy Technology Data Exchange (ETDEWEB)

    Yan, Baihan; Tong, Hao, E-mail: tonghao@hust.edu.cn; Qian, Hang; Miao, Xiangshui [Wuhan National Laboratory for Optoelectronics, Huazhong University of Science and Technology, Wuhan 430074 (China); School of Optical and Electronic Information, Huazhong University of Science and Technology, Wuhan 430074 (China)

    2015-09-28

    Phase change random access memory is one of the most important candidates for the next generation non-volatile memory technology. However, the ability to reduce its memory size is compromised by the fundamental limitations inherent in the CMOS technology. While 0T1R configuration without any additional access transistor shows great advantages in improving the storage density, the leakage current and small operation window limit its application in large-scale arrays. In this work, phase change heterojunction based on GeTe and n-Si is fabricated to address those problems. The relationship between threshold voltage and doping concentration is investigated, and energy band diagrams and X-ray photoelectron spectroscopy measurements are provided to explain the results. The threshold voltage is modulated to provide a large operational window based on this relationship. The switching performance of the heterojunction is also tested, showing a good reverse characteristic, which could effectively decrease the leakage current. Furthermore, a reliable read-write-erase function is achieved during the tests. Phase change heterojunction is proposed for high-density memory, showing some notable advantages, such as modulated threshold voltage, large operational window, and low leakage current.

  12. Corona noise model of high-voltage AC transmission lines and engineering applications

    Institute of Scientific and Technical Information of China (English)

    Wu Jiuhui; Di Zelong

    2013-01-01

    In order to predict the levels of corona noise from high-voltage alternating current (AC) transmission lines,the mechanism of corona noise and the corresponding theoretical prediction model are investigated.On the basis of Drude model,the motion of positive and negative ions produced by high-voltage corona is analyzed,and the mechanism of corona noise is discovered.The theoretical prediction model is put forward by using Kirchhoff formula,which is verified by the well agreement between our result and others',considering the case of three-phase single lines.Moreover,the calculation results show that for both single and bundled lines,the sound pressure level of the typical frequency,i.e.twice the power frequency,attenuates slowly and leads to an obviously interferential phenomenon near the transmission lines,but the level of the bundled lines is smaller than that of the single ones under the same transmission voltage.Based on the mechanism of corona noise and the prediction model,it is obvious that bundled lines and/or increased line radius can be adopted to reduce corona noise in the practical engineering applications effectively.This model can also provide a theoretical guidance for the high-volt-age AC transmission line design.

  13. Performance and scalability of isolated DC-DC converter topologies in low voltage, high current applications

    Energy Technology Data Exchange (ETDEWEB)

    Vaisanen, V.

    2012-07-01

    Fuel cells are a promising alternative for clean and efficient energy production. A fuel cell is probably the most demanding of all distributed generation power sources. It resembles a solar cell in many ways, but sets strict limits to current ripple, common mode voltages and load variations. The typically low output voltage from the fuel cell stack needs to be boosted to a higher voltage level for grid interfacing. Due to the high electrical efficiency of the fuel cell, there is a need for high efficiency power converters, and in the case of low voltage, high current and galvanic isolation, the implementation of such converters is not a trivial task. This thesis presents galvanically isolated DC-DC converter topologies that have favorable characteristics for fuel cell usage and reviews the topologies from the viewpoint of electrical efficiency and cost efficiency. The focus is on evaluating the design issues when considering a single converter module having large current stresses. The dominating loss mechanism in low voltage, high current applications is conduction losses. In the case of MOSFETs, the conduction losses can be efficiently reduced by paralleling, but in the case of diodes, the effectiveness of paralleling depends strongly on the semiconductor material, diode parameters and output configuration. The transformer winding losses can be a major source of losses if the windings are not optimized according to the topology and the operating conditions. Transformer prototyping can be expensive and time consuming, and thus it is preferable to utilize various calculation methods during the design process in order to evaluate the performance of the transformer. This thesis reviews calculation methods for solid wire, litz wire and copper foil winding losses, and in order to evaluate the applicability of the methods, the calculations are compared against measurements and FEM simulations. By selecting a proper calculation method for each winding type, the winding

  14. Estimation of Transformer Parameters and Loss Analysis for High Voltage Capacitor Charging Application

    DEFF Research Database (Denmark)

    Thummala, Prasanth; Schneider, Henrik; Ouyang, Ziwei

    2013-01-01

    In a bi-directional DC-DC converter for capacitive charging application, the losses associated with the transformer makes it a critical component. In order to calculate the transformer losses, its parameters such as AC resistance, leakage inductance and self capacitance of the high voltage (HV......) winding has to be estimated accurately. This paper analyzes the following losses of bi-directional flyback converter namely switching loss, conduction loss, gate drive loss, transformer core loss, and snubber loss, etc. Iterative analysis of transformer parameters viz., AC resistance, leakage inductance...

  15. 高压变频器及其应用%High-voltage Inverter and Its Application

    Institute of Scientific and Technical Information of China (English)

    张浩

    2001-01-01

    This paper analyses the relative problems on application of high-voltage variable-frequency technology. It also introduces the hardware structure and operation principle of IGCT-inverterin detail.%对高压变频技术应用的有关问题进行了分析,并详细介绍了IGCT变频器的硬件结构和工作原理。IGCT变频调速系统输出波形好,可靠性高,节能显著,是大容量变频调速较理想的解决方案。

  16. Performance and Environmental Test Results of the High Voltage Hall Accelerator Engineering Development Unit

    Science.gov (United States)

    Kamhawi, Hani; Haag, Thomas; Huang, Wensheng; Shastry, Rohit; Pinero, Luis; Peterson, Todd; Mathers, Alex

    2012-01-01

    NASA Science Mission Directorate's In-Space Propulsion Technology Program is sponsoring the development of a 3.5 kW-class engineering development unit Hall thruster for implementation in NASA science and exploration missions. NASA Glenn and Aerojet are developing a high fidelity high voltage Hall accelerator that can achieve specific impulse magnitudes greater than 2,700 seconds and xenon throughput capability in excess of 300 kilograms. Performance, plume mappings, thermal characterization, and vibration tests of the high voltage Hall accelerator engineering development unit have been performed. Performance test results indicated that at 3.9 kW the thruster achieved a total thrust efficiency and specific impulse of 58%, and 2,700 sec, respectively. Thermal characterization tests indicated that the thruster component temperatures were within the prescribed material maximum operating temperature limits during full power thruster operation. Finally, thruster vibration tests indicated that the thruster survived the 3-axes qualification full-level random vibration test series. Pre and post-vibration test performance mappings indicated almost identical thruster performance. Finally, an update on the development progress of a power processing unit and a xenon feed system is provided.

  17. Power angle control of grid-connected voltage source converter in a wind energy application

    Energy Technology Data Exchange (ETDEWEB)

    Svensson, Jan [Chalmers Univ. of Technology, Goeteborg (Sweden). Dept. of Electric Power Engineering

    1995-12-31

    In this thesis, the connection of a voltage source converter to the grid in a wind energy application is examined. The possibility of using a cheap control system without grid current measurements, is investigated. The control method is based on controlling the voltage angle of the inverter, which governs the active power flow. The highest frequency of the power variation, coming from wind turbine, is approx. 5 Hz. Since the proposed control method easily can handle such power variations it is very well suited for wind turbine applications. The characteristics of the system depend on the DC-link capacitor, the grid filter inductance and resistance. Large values of the resistance damp the system well but increase the energy losses. A high inductance leads to a reduced harmonic level on the grid but makes the system slower. By using feed-forward of the generator/rectifier current signal, the performance is increased compared to an ordinary PI-control. Combining the Linear Quadratic (LQ) control method with Kalman filtered input signals, a robust control method with a good performance is obtained. The LQ controller controls both the phase displacement angle and the modulation index, resulting in higher bandwidth, and the typical power angle resonance at the grid frequency disappears. 22 refs, 109 figs, 14 tabs

  18. High voltage bulk GaN-based photoconductive switches for pulsed power applications

    Science.gov (United States)

    Leach, J. H.; Metzger, R.; Preble, E. A.; Evans, K. R.

    2013-03-01

    Switches are at the heart of all pulsed power and directed energy systems, which find utility in a number of applications. At present, those applications requiring the highest power levels tend to employ spark-gap switches, but these suffer from relatively high delay-times (~10-8 sec), significant jitter (variation in delay time), and large size. That said, optically-triggered GaN-based photoconductive semiconductor switches (PCSS) offer a suitably small form factor and are a cost-effective, versatile solution in which delay times and jitter can be extremely short. Furthermore, the optical control of the switch means that they are electrically isolated from the environment and from any other system circuitry, making them immune from electrical noise, eliminating the potential for inadvertent switch triggering. Our recent work shows great promise to extend high-voltage GaN-based extrinsic PCSS state-of-the-art performance in terms of subnanosecond response times, low on-resistance, high current carrying capacity and high blocking voltages. We discuss our recent results in this work.

  19. Utilization of enzymes for environmental applications.

    Science.gov (United States)

    Ahuja, Sanjeev K; Ferreira, Gisela M; Moreira, Antonio R

    2004-01-01

    Enzymes are powerful tools that help sustain a clean environment in several ways. They are utilized for environmental purposes in a number of industries including agro-food, oil, animal feed, detergent, pulp and paper, textile, leather, petroleum, and specialty chemical and biochemical industry. Enzymes also help to maintain an unpolluted environment through their use in waste management. Recombinant DNA technology, protein engineering, and rational enzyme design are the emerging areas of research pertaining to environmental applications of enzymes. The future will also see the employment of various technologies including gene shuffling, high throughput screening, and nanotechnology. This article presents an overview of the enzymatic applications in pollution control and the promising research avenues in this area.

  20. Remote sensing applications in environmental research

    CERN Document Server

    Srivastava, Prashant K; Gupta, Manika; Islam, Tanvir

    2014-01-01

    Remote Sensing Applications in Environmental Research is the basis for advanced Earth Observation (EO) datasets used in environmental monitoring and research. Now that there are a number of satellites in orbit, EO has become imperative in today's sciences, weather and natural disaster prediction. This highly interdisciplinary reference work brings together diverse studies on remote sensing and GIS, from a theoretical background to its applications, represented through various case studies and the findings of new models. The book offers a comprehensive range of contributions by well-known scientists from around the world and opens a new window for students in presenting interdisciplinary and methodological resources on the latest research. It explores various key aspects and offers state-of-the-art research in a simplified form, describing remote sensing and GIS studies for those who are new to the field, as well as for established researchers.

  1. Environmental Applications of Biosurfactants: Recent Advances

    Directory of Open Access Journals (Sweden)

    Swaranjit Singh Cameotra

    2011-01-01

    Full Text Available Increasing public awareness of environmental pollution influences the search and development of technologies that help in clean up of organic and inorganic contaminants such as hydrocarbons and metals. An alternative and eco-friendly method of remediation technology of environments contaminated with these pollutants is the use of biosurfactants and biosurfactant-producing microorganisms. The diversity of biosurfactants makes them an attractive group of compounds for potential use in a wide variety of industrial and biotechnological applications. The purpose of this review is to provide a comprehensive overview of advances in the applications of biosurfactants and biosurfactant-producing microorganisms in hydrocarbon and metal remediation technologies.

  2. Environmental applications of biosurfactants: recent advances.

    Science.gov (United States)

    Pacwa-Płociniczak, Magdalena; Płaza, Grażyna A; Piotrowska-Seget, Zofia; Cameotra, Swaranjit Singh

    2011-01-18

    Increasing public awareness of environmental pollution influences the search and development of technologies that help in clean up of organic and inorganic contaminants such as hydrocarbons and metals. An alternative and eco-friendly method of remediation technology of environments contaminated with these pollutants is the use of biosurfactants and biosurfactant-producing microorganisms. The diversity of biosurfactants makes them an attractive group of compounds for potential use in a wide variety of industrial and biotechnological applications. The purpose of this review is to provide a comprehensive overview of advances in the applications of biosurfactants and biosurfactant-producing microorganisms in hydrocarbon and metal remediation technologies.

  3. Atmospheric plasma processes for environmental applications

    OpenAIRE

    Shapoval, Volodymyr

    2012-01-01

    Plasma chemistry is a rapidly growing field which covers applications ranging from technological processing of materials, including biological tissues, to environmental remediation and energy production. The so called atmospheric plasma, produced by electric corona or dielectric barrier discharges in a gas at atmospheric pressure, is particularly attractive for the low costs and ease of operation and maintenance involved. The high concentrations of energetic and chemically active species (e.g...

  4. Atmospheric plasma processes for environmental applications

    OpenAIRE

    Shapoval, Volodymyr

    2012-01-01

    Plasma chemistry is a rapidly growing field which covers applications ranging from technological processing of materials, including biological tissues, to environmental remediation and energy production. The so called atmospheric plasma, produced by electric corona or dielectric barrier discharges in a gas at atmospheric pressure, is particularly attractive for the low costs and ease of operation and maintenance involved. The high concentrations of energetic and chemically active species (e.g...

  5. Analysis of a Three-Level LLC Series Resonant Converter for High- and Wide-Input-Voltage Applications

    Directory of Open Access Journals (Sweden)

    S.Saravanan

    2014-04-01

    Full Text Available In this paper, the analysis of a three-level LLC series resonant converter (TL LLC SRC for high- and wide input-voltage applications is presented. It consists of two half-bridge LLC SRCs in series, sharing a resonant inductor and a transformer. Its main advantages are that the voltage across each switch is clamped at half of the input voltage and that voltage balance is achieved and simple driving signals . Thus it is suitable for high-inputvoltage applications. Based on the results of these analyses, a design example is provided and its validity is confirmed by an experiment involving a prototype converter with an input of 600V and an output of 48 V/20 A.

  6. A high voltage ratio and low ripple interleaved DC-DC converter for fuel cell applications.

    Science.gov (United States)

    Chang, Long-Yi; Chao, Kuei-Hsiang; Chang, Tsang-Chih

    2012-01-01

    This paper proposes a high voltage ratio and low ripple interleaved boost DC-DC converter, which can be used to reduce the output voltage ripple. This converter transfers the low DC voltage of fuel cell to high DC voltage in DC link. The structure of the converter is parallel with two voltage-doubler boost converters by interleaving their output voltages to reduce the voltage ripple ratio. Besides, it can lower the current stress for the switches and inductors in the system. First, the PSIM software was used to establish a proton exchange membrane fuel cell and a converter circuit model. The simulated and measured results of the fuel cell output characteristic curve are made to verify the correctness of the established simulation model. In addition, some experimental results are made to validate the effectiveness in improving output voltage ripple of the proposed high voltage ratio interleaved boost DC-DC converters.

  7. Biological and Agricultural Studies on Application of Discharge Plasma and Electromagnetic Fields 4. Destruction of Weeds by High Voltage Discharge

    Science.gov (United States)

    Mizuno, Akira

    In an attempt to replace chemicals for weed control, high voltage spark discharge has been applied. With the application of high voltage, discharge takes place, and current flows through the stem and root. Microscopic observation indicates that cells are damaged. The electrical resistance of the damage plant’s stems and roots decreased significantly. Several different types of apparatus were constructed, and field test results show the effectiveness of electrical discharge for weed control.

  8. Photocatalytic semiconductors synthesis, characterization, and environmental applications

    CERN Document Server

    Hernández-Ramírez, Aracely

    2014-01-01

    This critical volume examines the different methods used for the synthesis of a great number of photocatalysts, including TiO2, ZnO and other modified semiconductors, as well as characterization techniques used for determining the optical, structural and morphological properties of the semiconducting materials. Additionally, the authors discuss photoelectrochemical methods for determining the light activity of the photocatalytic semiconductors by means of measurement of properties such as band gap energy, flat band potential and kinetics of hole and electron transfer. Photocatalytic Semiconductors: Synthesis, Characterization and Environmental Applications provide an overview of the semiconductor materials from first- to third-generation photocatalysts and their applications in wastewater treatment and water disinfection. The book further presents economic and toxicological aspects in the production and application of photocatalytic materials.

  9. OPC Server and BridgeView Application for High Voltage Power Supply Lecroy 1458

    CERN Document Server

    Swoboda, D; CERN. Geneva

    2000-01-01

    Abstract The aim of this project was to develop an OPC server to communicate over an RS232 serial line. This communication media is commonly used with commercial instruments. The development was made for a High Voltage power supply in the context of the Alice [1] experiment. In addition, the structured modular concept will allow changing the transmission media or power supply type with little effort. The high voltage power supply should be accessible remotely through a network. OPC[2] is an acronym for OLE[3] for Process Control. OPC is based on the DCOM [3] communication protocol, which allows communication with any computer running a Windows based OS. This standard is widely used in industry to access device data through Windows applications. The concept is based on the client-server architecture. The hardware and the software architecture are described. Subsequently details of the implemented programs are given with emphasis on the possibility to replace parts of the software in order to use differ...

  10. Selection of a suitable vegetable oil for high voltage insulation applications

    Science.gov (United States)

    Hosier, I. L.; Guushaa, A.; Vaughan, A. S.; Swingler, S. G.

    2009-08-01

    Many items of high voltage plant employ a liquid both as a dielectric and a coolant. Currently these systems use a mineral oil, however, this suffers from the drawback of being potentially toxic and hence leakages and eventual disposal can be serious issues. To overcome this problem, an increasing trend in the UK is to backfill existing paper/oil cable systems with dodecylbenzene (DDB). This fluid possesses the advantages of improved gas absorption, good dielectric properties and biodegradability; nevertheless it is still derived from crude oil, a non-renewable resource. Vegetable oils offer the added advantage of being renewable although many types are available with very different properties. In order to select a suitable vegetable oil for high voltage applications, a standardised ageing and testing regime is required. In this paper, a wide range of vegetable oils were subjected to controlled laboratory ageing and the resulting aged oils were characterised by a number of analytical techniques. The results from these tests were then used to rank the different oils, and to select the most ageing resistant oil.

  11. Application of Load Compensation in Voltage Controllers of Large Generators in the Polish Power Grid

    Directory of Open Access Journals (Sweden)

    Bogdan Sobczak

    2014-03-01

    Full Text Available The Automatic Voltage Regulator normally controls the generator stator terminal voltage. Load compensation is used to control the voltage which is representative of the voltage at a point either within or external to the generator. In the Polish Power Grid (PPG compensation is ready to use in every AVR of a large generator, but it is utilized only in the case of generators operating at the same medium voltage buses. It is similar as in most European Power Grids. The compensator regulating the voltage at a point beyond the machine terminals has significant advantages in comparison to the slower secondary Voltage and Reactive Power Control System (ARNE1. The compensation stiffens the EHV grid, which leads to improved voltage quality in the distribution grid. This effect may be particularly important in the context of the dynamic development of wind and solar energy.

  12. Application of Electromigration Techniques in Environmental Analysis

    Science.gov (United States)

    Bald, Edward; Kubalczyk, Paweł; Studzińska, Sylwia; Dziubakiewicz, Ewelina; Buszewski, Bogusław

    Inherently trace-level concentration of pollutants in the environment, together with the complexity of sample matrices, place a strong demand on the detection capabilities of electromigration methods. Significant progress is continually being made, widening the applicability of these techniques, mostly capillary zone electrophoresis, micellar electrokinetic chromatography, and capillary electrochromatography, to the analysis of real-world environmental samples, including the concentration sensitivity and robustness of the developed analytical procedures. This chapter covers the recent major developments in the domain of capillary electrophoresis analysis of environmental samples for pesticides, polycyclic aromatic hydrocarbons, phenols, amines, carboxylic acids, explosives, pharmaceuticals, and ionic liquids. Emphasis is made on pre-capillary and on-capillary chromatography and electrophoresis-based concentration of analytes and detection improvement.

  13. Ceramics in Environmental Catalysis:Applications and Possibilities%Ceramics in Environmental Catalysis: Applications and Possibilities

    Institute of Scientific and Technical Information of China (English)

    Nitin LABHSETWAR; P.DOGGALI; S.RAYALU; R.YADAV; T.MISTUHASHI; H.HANEDA

    2012-01-01

    Environmental catalysis has been steadily growing because of the advances in its scientific and engineering aspects,as well as due to the new environmental challenges in the industrial era.The development of new catalysts and materials is essential for new technologies for various environmental applications.Ceramics play important roles in various environmental applications including the identification,monitoring,and quantification of pollutants and their control.Ceramics have important applications as sensors and photocatalysts,and they are extensively used as catalyst carriers and supports.Many ceramics are being explored as catalysts for pollution control applications.Their low cost,thermal and chemical stability,and capability of being tailored make them especially attractive for pollution control applications.Although a wide variety of materials have been developed as catalyst supports,this area is still of interest with new or modified catalyst supports being frequently reported.It is of equal importance to develop new or modified processes for the loading of catalysts on specific supports.Applications like chemical looping combustion (CLC) and other catalytic combustion processes are raising the demands to a new scale.We have been working on the development of both new and modified support materials,including mesoporous materials without structural order for possible applications in CLC and other catalytic reactions.Successful attempts have been made in the modification of conventional γ-Al2O3 and improved synthesis processes for supporting perovskite type catalysts.Our research on environmental catalysis applications of ceramic materials and processes are also briefly discussed.

  14. Self-discharge analysis and characterization of supercapacitors for environmentally powered wireless sensor network applications

    Science.gov (United States)

    Yang, Hengzhao; Zhang, Ying

    2011-10-01

    A new approach is presented to characterize the variable leakage resistance, a parameter in the variable leakage resistance model we developed to model supercapacitors used in environmentally powered wireless sensor network applications. Based on an analysis of the supercapacitor terminal behavior during the self-discharge, the variable leakage resistance is modeled as a function of the supercapacitor terminal voltage instead of the self-discharge time, which is more practical for an environmentally powered wireless sensor node. The new characterization approach is implemented and validated using MATLAB Simulink with a 10 F supercapacitor as an example. In addition, effects of initial voltages and temperatures on the supercapacitor self-discharge rate and the variable leakage resistance value are explored.

  15. Applications of scientific imaging in environmental toxicology

    Science.gov (United States)

    El-Demerdash, Aref M.

    The national goals of clean air, clean water, and healthy ecosystems are a few of the primary forces that drive the need for better environmental monitoring. As we approach the end of the 1990s, the environmental questions at regional to global scales are being redefined and refined in the light of developments in environmental understanding and technological capability. Research in the use of scientific imaging data for the study of the environment is urgently needed in order to explore the possibilities of utilizing emerging new technologies. The objective of this research proposal is to demonstrate the usability of a wealth of new technology made available in the last decade to providing a better understanding of environmental problems. Research is focused in two imaging techniques macro and micro imaging. Several examples of applications of scientific imaging in research in the field of environmental toxicology were presented. This was achieved on two scales, micro and macro imaging. On the micro level four specific examples were covered. First, the effect of utilizing scanning electron microscopy as an imaging tool in enhancing taxa identification when studying diatoms was presented. Second, scanning electron microscopy combined with energy dispersive x-ray analyzer were demonstrated as a valuable and effective tool for identifying and analyzing household dust samples. Third, electronic autoradiography combined with FT-IR microscopy were used to study the distribution pattern of [14C]-Malathion in rats as a result of dermal exposure. The results of the autoradiography made on skin sections of the application site revealed the presence of [ 14C]-activity in the first region of the skin. These results were evidenced by FT-IR microscopy. The obtained results suggest that the penetration of Malathion into the skin and other tissues is vehicle and dose dependent. The results also suggest the use of FT-IR microscopy imaging for monitoring the disposition of

  16. 34 CFR 75.601 - Applicant's assessment of environmental impact.

    Science.gov (United States)

    2010-07-01

    ... 34 Education 1 2010-07-01 2010-07-01 false Applicant's assessment of environmental impact. 75.601... Conditions Must Be Met by a Grantee? Construction § 75.601 Applicant's assessment of environmental impact. An applicant shall include with its application its assessment of the impact of the proposed construction on...

  17. Functional Nanomaterials for Environmental Applications and Bioassemblies

    Science.gov (United States)

    Nguyen, Michelle Anne

    The rational design of nanomaterials has yielded new technologies that have revolutionized numerous diverse fields. The work detailed herein first describes the application of photocatalytic nanomaterials towards the environmental remediation of harmful toxins. Specifically, a low-temperature solution-phase synthetic route for size-controlled Cu2O octahedra particles was developed, and these materials were evaluated as catalysts for the photocatalytic degradation of aromatic organic compounds. Moreover, cubic Cu2O/Pd composite structures were fabricated and demonstrated to be effective photocatalysts for the generation of H2 and the reductive dehalogenation of polychlorinated biphenyls, well-known carcinogens present at many contaminated sites around the world. This photocatalytic approach to environmental remediation exemplifies the adaptation of light-driven technologies and sustainable practices to energy-intensive catalytic systems. In addition, this work also investigates the organic/inorganic interface of peptide-mediated Au nanoparticles as a means to identify rational design principles for materials binding peptide sequences for the advancement of stimuli-responsive bionanoassemblies. Factors inherent to peptide sequences that can promote strong materials-binding affinity and/or effective nanoparticle stabilization capability were identified in order to progress biomimetic technologies. These findings were elucidated using a combinational approach of peptide binding experiments to Au in partnership with molecular dynamics simulations. Overall, this work demonstrates the growing applications of nanomaterials in remediation technologies and aids in the understanding of the origins of peptide material affinity and nanoparticle stabilization.

  18. Environmental implications and applications of nanomaterials

    Science.gov (United States)

    Bhattacharya, Priyanka

    Recent advances in material science and nanotechnology have given rise to a myriad of developments, while in the meantime call for research into the impacts of nanomaterials on the environment and human health. Although considerable progress has been made in the past decade concerning the behavior of nanomaterials in biological systems, such understanding is critically lacking with respect to the fate of nanomaterials in ecosystems. Accordingly, this dissertation addresses the interactions between nanomaterials and algae---the major constituent of the aquatic food chain (Part I, Chapter two), and exploits the physicochemistry of nanoscaled synthetic dendritic polymers for environmental applications, especially for water purification that is a focused theme of the entire dossier (Part II, Chapters two--five). This dissertation is organized as follows. Chapter one presents a general review of the physical/physicochemical properties, characterizations, implications---especially ecological implication, and applications of a host of most produced and studied nanomaterials. In addition, advances in environmental applications of nanomaterials are discussed. Chapter two examines algal responses to two major types of engineered nanomaterials---quantum dots and polystyrene. Inhibited photosynthetic activities of green algae are observed as a result of the physical adsorption of the nanomaterials. Chapter three elucidates the physicochemical properties of poly(amidoamine)-tris(hydroxymethyl)amidomethane- and amine-terminated dendrimers towards their applications in water remediation. Here, the capacities and mechanisms of the dendrimers in hosting cationic copper, anionic nitrate, polyaromatic phenanthrene, and the more heterogeneous humic acids are discussed. Based on the results of Chapter three, Chapter four presents a dendrimer-based novel optical scheme for improving the detection sensitivity and selectivity of environmental pollutants. Specifically, the surface plasmon

  19. Design of 154 kV Extra-High-Voltage Prototype SF6 Bushing for Superconducting Electric Power Applications

    Science.gov (United States)

    Koo, Ja-yoon; Seong, Jae-gyu; Hwang, Jae-sang; Lee, Bang-wook; Lee, Sang-hwa

    2012-09-01

    One of the critical components to be developed for high-voltage superconducting devices, such as superconducting transformers, cables, and fault current limiters, is a high-voltage bushing to supply a high current to devices without insulation difficulties in cryogenic environments. Unfortunately, suitable bushings for high-temperature-superconductivity (HTS) equipment have not been fully developed to address cryogenic insulation issues. As a fundamental step towards developing the optimum design of the 154 kV prototype SF6 bushing of HTS devices, the puncture and creepage breakdown voltages of glass-fiber-reinforced-plastic (GFRP) were analyzed with a variety of configurations of electrodes and gap distances in the insulation material. And design factors of high-voltage cryogenic bushings were obtained from the result of tests. Finally, the withstand voltage tests of manufacturing a 154 kV extra-high-voltage (EHV) prototype bushing has been performed. Consequently, we verified the insulation level of the newly designed 154 kV EHV cryogenic prototype bushings for superconducting electric power applications.

  20. Fuzzy Controller for a Voltage-Regulated Solar-Powered MPPT System for Hybrid Power System Applications

    Directory of Open Access Journals (Sweden)

    Jaw-Kuen Shiau

    2015-04-01

    Full Text Available This paper presents the design of a fuzzy-logic-based voltage-regulated solar power maximum power point tracking (MPPT system for applications involving hybrid power systems. The system contains a solar power system and battery as the primary and secondary power sources, respectively. The solar system alone supplies power to the electric motor and maintains the output voltage at a predetermined level when it has sufficient power. When the solar power is insufficient, the solar system is operated at its maximum power point (MPP and the battery is engaged to compensate for the insufficiency. First, a variant of the incremental conductance MPP condition was established. Under the MPP condition, the voltage-regulated MPPT system was formulated as a feedback control system, where the MPP condition and voltage regulation requirements were used as the system inputs. Next, a fuzzy controller was developed to perform the voltage-regulated MPPT function for the hybrid power system. A simulation model based on Matrix laboratory (MATLAB/SIMULINK (a block diagram environment for multi-domain simulation and model-based design and a piecewise linear electric circuit simulation (PLECS tool for controlling the dc motor velocity was developed to verify the voltage-regulated solar power MPPT system.

  1. A NOVEL METHOD OF VOLTAGE SAG AND SWELL ESTIMATION FOR POWER SYSTEM APPLICATIONS

    Directory of Open Access Journals (Sweden)

    A. Vetrivel

    2013-01-01

    Full Text Available This study presents four simple mathematical models to build the voltage shape with the knowledge of few parameters and detects voltage sag and swells accurately. Fourier series, cubic polynomial, Rational functions and Sum of Sin functions are used in this study to model the voltage profile. A new algorithm is developed to detect sag or swell in all the four models. The voltage estimation due to cubic polynomial has more voltage error and then rational function. The sum of sine function and Fourier series functions does accurate voltage estimation. Errors due to various functions are also tabulated for one electrical cycle. The performance of each method has been compared with other to know the effectiveness of different models and their results are presented.

  2. Negative-resistance voltage-current characteristics of superconductor contact junctions for macro-scale applications

    CERN Document Server

    Takayasu, M; Minervini, J V; 10.1109/TASC.2003.812854

    2003-01-01

    Voltage-current characteristics of mechanical pressure contact junctions between superconducting wires are investigated using a voltage-driving method. It is found that the switching regions at low voltages result from negative resistance of the contact junction. The current transport of the contact junctions is discussed from the perspective of two existing models: the multiple Andreev reflections at the two SN interfaces of a SNS (Superconductor/Normal metal /Superconductor) junction and the inhomogeneous multiple Josephson weak-link array. (13 refs).

  3. Wind Power Plant Voltage Control Optimization with Embedded Application of Wind Turbines and Statcom

    DEFF Research Database (Denmark)

    Wu, Qiuwei; Solanas, Jose Ignacio Busca; Zhao, Haoran

    2017-01-01

    Increasing wind power penetration and the size of wind power plants (WPPs) brings challenges to the operation and control of power systems. Most of WPPs are located far from load centers and the short circuit ratio at the point of common coupling (PCC) is low. The fluctuations of wind power...... will cause voltage variations. An optimal voltage control scheme for WPPs with STATCOMs is presented in the paper. It ensures that the voltages within the WPPs and at the high voltage side of the WPPs are within the limits and maximizes the dynamic Var reserve of the WPPs. Case studies were conducted...

  4. The piezoelectronic stress transduction switch for very large-scale integration, low voltage sensor computation, and radio frequency applications

    Science.gov (United States)

    Magdǎu, I.-B.; Liu, X.-H.; Kuroda, M. A.; Shaw, T. M.; Crain, J.; Solomon, P. M.; Newns, D. M.; Martyna, G. J.

    2015-08-01

    The piezoelectronic transduction switch is a device with potential as a post-CMOS transistor due to its predicted multi-GHz, low voltage performance on the VLSI-scale. However, the operating principle of the switch has wider applicability. We use theory and simulation to optimize the device across a wide range of length scales and application spaces and to understand the physics underlying its behavior. We show that the four-terminal VLSI-scale switch can operate at a line voltage of 115 mV while as a low voltage-large area device, ≈200 mV operation at clock speeds of ≈2 GHz can be achieved with a desirable 104 On/Off ratio—ideal for on-board computing in sensors. At yet larger scales, the device is predicted to operate as a fast (≈250 ps) radio frequency (RF) switch exhibiting high cyclability, low On resistance and low Off capacitance, resulting in a robust switch with a RF figure of merit of ≈4 fs. These performance benchmarks cannot be approached with CMOS which has reached fundamental limits. In detail, a combination of finite element modeling and ab initio calculations enables prediction of switching voltages for a given design. A multivariate search method then establishes a set of physics-based design rules, discovering the key factors for each application. The results demonstrate that the piezoelectronic transduction switch can offer fast, low power applications spanning several domains of the information technology infrastructure.

  5. "Smart pebble" design for environmental monitoring applications

    Science.gov (United States)

    Valyrakis, Manousos; Pavlovskis, Edgars

    2014-05-01

    Sediment transport, due to primarily the action of water, wind and ice, is one of the most significant geomorphic processes responsible for shaping Earth's surface. It involves entrainment of sediment grains in rivers and estuaries due to the violently fluctuating hydrodynamic forces near the bed. Here an instrumented particle, namely a "smart pebble", is developed to investigate the exact flow conditions under which individual grains may be entrained from the surface of a gravel bed. This could lead in developing a better understanding of the processes involved, while focusing on the response of the particle during a variety of flow entrainment events. The "smart pebble" is a particle instrumented with MEMS sensors appropriate for capturing the hydrodynamic forces a coarse particle might experience during its entrainment from the river bed. A 3-axial gyroscope and accelerometer registers data to a memory card via a microcontroller, embedded in a 3D-printed waterproof hollow spherical particle. The instrumented board is appropriately fit and centred into the shell of the pebble, so as to achieve a nearly uniform distribution of the mass which could otherwise bias its motion. The "smart pebble" is powered by an independent power to ensure autonomy and sufficiently long periods of operation appropriate for deployment in the field. Post-processing and analysis of the acquired data is currently performed offline, using scientific programming software. The performance of the instrumented particle is validated, conducting a series of calibration experiments under well-controlled laboratory conditions. "Smart pebble" allows for a wider range of environmental sensors (e.g. for environmental/pollutant monitoring) to be incorporated so as to extend the range of its application, enabling accurate environmental monitoring which is required to ensure infrastructure resilience and preservation of ecological health.

  6. Portable cosmic muon telescope for environmental applications

    Energy Technology Data Exchange (ETDEWEB)

    Barnafoeldi, Gergely Gabor [Institute for Particle and Nuclear Physics, Wigner Research Centre for Physics, Hungarian Academy of Sciences, 29-33 Konkoly-Thege Miklos Str., H-1121 Budapest (Hungary); Hamar, Gergo [Institute for Particle and Nuclear Physics, Wigner Research Centre for Physics, Hungarian Academy of Sciences, 29-33 Konkoly-Thege Miklos Str., H-1121 Budapest (Hungary); Department of Physics of Complex Systems, Eoetvoes University, 1/A Pazmany P. setany, H-1117 Budapest (Hungary); Melegh, Hunor Gergely [Budapest University of Technology and Economics, 3-9 Muegyetem rkp., H-1111 Budapest (Hungary); Olah, Laszlo [Department of Physics of Complex Systems, Eoetvoes University, 1/A Pazmany P. setany, H-1117 Budapest (Hungary); Suranyi, Gergely [Geological, Geophysical and Space Science Research Group of the HAS, Eoetvoes University, 1/C Pazmany P. setany, H-1117 Budapest (Hungary); Varga, Dezso, E-mail: dezso.varga@cern.ch [Department of Physics of Complex Systems, Eoetvoes University, 1/A Pazmany P. setany, H-1117 Budapest (Hungary)

    2012-10-11

    A portable, low power consumption cosmic muon tracking system based on Close Cathode MWPC technology is presented, which is designed for operation in highly humid environmental conditions such as underground caves, tunnels, or cellars. The system measures the angular distribution of cosmic muons with resolution of 10 mrad, allowing for a tomographic mapping of the soil density above the detector unit. The size of the detector, 0.1 m{sup 2} of total sensitive surface, was designed to fulfill the requirement of transport through humanly passable natural cave tunnels. First results from the Ariadne Cave System in Pilis Mountains, Hungary are shown, which constrains the necessary data taking time for meaningful tomographic mapping. -- Highlights: Black-Right-Pointing-Pointer Cosmic muon tracking system for underground applications presented. Black-Right-Pointing-Pointer Operation in highly humid environment of natural caves demonstrated. Black-Right-Pointing-Pointer Tomographic mapping at 60 m depth was performed during 50 days in Pilis Mountains, Hungary.

  7. Japanese application of bioassays for environmental management.

    Science.gov (United States)

    Kusui, Takashi

    2002-03-02

    The increasing number of existing and new chemicals demands ecotoxicological data as well as toxicological data for pre- and postmarketing risk assessments. Although human health has been the major concern in Japanese environmental management, ecosystem health is becoming the big issue as the need for preserving the diversity of ecosystems has been recognized. This recognition is changing the regulatory framework in Japan, resulting in new actions toward establishment of water-quality standards for aquatic organisms and ecotoxicological assessment of existing chemicals. At the same time, the need to assess complex liquids that contain several kinds of chemicals is increasing. The ecotoxicological study of Japanese effluents shows that the present chemical-specific standards are not enough to protect aquatic ecosystems. These two factors encourage the application of ecotoxicological tests as well as the toxicological data.

  8. Miniaturised Space Payloads for Outdoor Environmental Applications

    Science.gov (United States)

    de Souza, P. A.

    2012-12-01

    The need for portable, robust and acurate sensors has increased in recent years resulting from industrial and environmental needs. This paper describes a number of applications of engineering copies of those Moessbauer spectrometers (MIMOS II) used by Mars Exploration Rovers, and the use of portable XRF spectrometers in the analysis of heavy metals in sediments. MIMOS II has been applied in the characterisation of Fe-bearing phases in airborne particles in industrialised urban centres, The results have allowed an identification of sources or air pollution in near-real-time. The results help to combine production parameters with pollution impact in the urban area. MIMOS II became a powerful tool because its constructive requirements to flight has produced a robust, power efficient, miniaturised, and light. On the limitation side, the technique takes sometime to produce a good result and the instrument requires a radioactive source to operate. MIMOS II Team has reported a new generation of this instrument incorporating a XRF spectrometer using the radioactive source to generate fluorescence emissions from sample. The author, and its research group, adapted a portable XRF spectrometer to an autonomous underwater vehicle (AUV) and conducted heavy metals survey in sediments across the Derwent Estuary in Tasmania, Australia. The AUV lands on suitable locations underwater, makes the chemical analysis and decide based on the result to move to a closer location, should high concentration of chemicals of interest be found, or to another distant location otherwise. Beyond environmental applications, these instruments were applied in archaeology and in industrial process control.oessbauer spectra recorded on airborne particles (Total Suspended Particles) collected at Ilha do Boi, VItoria, ES, Brazil. SIRO's Autonomous Underwater Vehicle carring a miniaturised XRF spectrometer for underwater chemistry. Students involved in this Project: Mr Jeremy Breen and Mr Andrew Davie

  9. Environmental Ethics in Theory and Practical Application | Kelbessa ...

    African Journals Online (AJOL)

    Environmental Ethics in Theory and Practical Application. ... bring the insights of environmental ethics into various natural resource management settings. ... knowledge of the natural environment and help them develop further knowledge of it.

  10. Application of Georeferencing in the management of environmental ...

    African Journals Online (AJOL)

    Application of Georeferencing in the management of environmental pollution in the ... range of important ecosystem goods and services provided by the Niger Delta ... opportunities in the accurate monitoring and assessment of environmental ...

  11. A new application area for fullerenes: voltage stabilizers for power cable insulation.

    Science.gov (United States)

    Jarvid, Markus; Johansson, Anette; Kroon, Renee; Bjuggren, Jonas M; Wutzel, Harald; Englund, Villgot; Gubanski, Stanislaw; Andersson, Mats R; Müller, Christian

    2015-02-01

    Fullerenes are shown to be efficient voltage-stabilizers for polyethylene, i.e., additives that increase the dielectric strength of the insulation material. Such compounds are highly sought-after because their use in power-cable insulation may considerably enhance the transmission efficiency of tomorrow's power grids. On a molal basis, fullerenes are the most efficient voltage stabilizers reported to date.

  12. 65NM sub-threshold 11T-SRAM for ultra low voltage applications

    DEFF Research Database (Denmark)

    Moradi, Farshad; Wisland, Dag T.; Aunet, Snorre;

    simulated results. The circuit was simulated for supply voltages from 0.2 V to 0.35 V verifying the robustness of the proposed circuit for different supply voltages. The simulations show a significant improvement in SNM and a 4X improvement in read speed still maintaining a satisfactory write noise margin...

  13. 65NM sub-threshold 11T-SRAM for ultra low voltage applications

    DEFF Research Database (Denmark)

    Moradi, Farshad; Wisland, Dag T.; Aunet, Snorre

    simulated results. The circuit was simulated for supply voltages from 0.2 V to 0.35 V verifying the robustness of the proposed circuit for different supply voltages. The simulations show a significant improvement in SNM and a 4X improvement in read speed still maintaining a satisfactory write noise margin...

  14. Electronics drivers for high voltage dielectric electro active polymer (DEAP) applications

    DEFF Research Database (Denmark)

    Zhang, Zhe; Andersen, Michael A. E.

    2015-01-01

    ), but the voltage balancing across the series - connected high voltage IGBTs is a critical issue and accordi ngly a novel gate driver circuitry is proposed and equipped; due to the requirements of the audio products, such as low distortion and noise, the multi - level Buck converter based Class - D amplifier...

  15. Application of Multipoint DC Voltage Control in VSC-MTDC System

    Directory of Open Access Journals (Sweden)

    Yang Xi

    2013-01-01

    Full Text Available The voltage-source-converter- (VSC- based multiterminal VSC-HVDC power transmission system (VSC-MTDC is an ideal approach to connect wind farm with power grid. Analyzing the characteristics of doubly fed induction generators as well as the basic principle and the control strategy of VSC-MTDC, a multiterminal DC voltage control strategy suitable for wind farm connected with VSC-MTDC is proposed. By use of PSCAD/EMTDC, the proposed control strategy is simulated, and simulation results show that using the proposed control strategy the conversion between constant power control mode and constant DC voltage control mode can be automatically implemented; thus the DC voltage stability control and reliable power output of wind farm can be ensured after the fault-caused outage of converter station controlled by constant DC voltage and under other faults. The simulation result shows that the model can fulfill multiterminal power transmission and fast response control.

  16. Graphene for Environmental and Biological Applications

    Science.gov (United States)

    Sreeprasad, T. S.; Pradeep, T.

    2012-08-01

    The latest addition to the nanocarbon family, graphene, has been proclaimed to be the material of the century. Its peculiar band structure, extraordinary thermal and electronic conductance and room temperature quantum Hall effect have all been used for various applications in diverse fields ranging from catalysis to electronics. The difficulty to synthesize graphene in bulk quantities was a limiting factor of it being utilized in several fields. Advent of chemical processes and self-assembly approaches for the synthesis of graphene analogues have opened-up new avenues for graphene based materials. The high surface area and rich abundance of functional groups present make chemically synthesized graphene (generally known as graphene oxide (GO) and reduced graphene oxide (RGO) or chemically converted graphene) an attracting candidate in biotechnology and environmental remediation. By functionalizing graphene with specific molecules, the properties of graphene can be tuned to suite applications such as sensing, drug delivery or cellular imaging. Graphene with its high surface area can act as a good adsorbent for pollutant removal. Graphene either alone or in combination with other materials can be used for the degradation or removal of a large variety of contaminants through several methods. In this review some of the relevant efforts undertaken to utilize graphene in biology, sensing and water purification are described. Most recent efforts have been given precedence over older works, although certain specific important examples of the past are also mentioned.

  17. Biomedical and environmental applications of magnetic nanoparticles

    Science.gov (United States)

    Tran, Dai Lam; Le, Van Hong; Linh Pham, Hoai; Nhung Hoang, Thi My; Quy Nguyen, Thi; Luong, Thien Tai; Thu Ha, Phuong; Phuc Nguyen, Xuan

    2010-12-01

    This paper presents an overview of syntheses and applications of magnetic nanoparticles (MNPs) at the Institute of Materials Science, Vietnam Academy of Science and Technology. Three families of oxide MNPs, magnetite, manganite and spinel ferrite materials, were prepared in various ways: coprecipitation, sol-gel and high energy mechanical milling. Basic properties of MNPs were characterized by Vibrating Sample Magnetometer (VSM) and Physical Properties Measurement Systems (PPMS). As for biomedical application, the aim was to design a novel multifunctional, nanosized magnetofluorescent water-dispersible Fe3O4-curcumin conjugate, and its ability to label, target and treat tumor cells was described. The conjugate possesses a magnetic nano Fe3O4 core, chitosan (CS) or Oleic acid (OL) as an outer shell and entrapped curcumin (Cur), serving the dual function of naturally autofluorescent dye as well as antitumor model drug. Fe3O4-Cur conjugate exhibited a high loading cellular uptake with the help of a macrophage, which was clearly visualized dually by Fluorescence Microscope and Laser Scanning Confocal Microscope (LSCM), as well as by magnetization measurement (PPMS). A preliminary magnetic resonance imaging (MRI) study also showed a clear contrast enhancement by using the conjugate. As for the environmental aspect, the use of magnetite MNPs for the removal of heavy toxic metals, such as Arsenic (As) and Lead (Pb), from contaminated water was studied.

  18. Valorisation of grape pomace by the extraction of phenolic antioxidants: Application of high voltage electrical discharges.

    Science.gov (United States)

    Boussetta, N; Vorobiev, E; Deloison, V; Pochez, F; Falcimaigne-Cordin, A; Lanoisellé, J-L

    2011-09-15

    The aim of this study was to optimise the electrically assisted extraction in order to obtain grape pomace extracts with high polyphenols content, which would be potentially interesting for applications as natural antioxidants. High voltage electrical discharges (HVED) were applied for intensification of the extraction. The effects of the energy input, the electrodes distance gap and the liquid-to-solid ratio were studied. Diffusion was then carried out in different mixtures of water and ethanol for one hour at 20, 30, 40 and 60°C. The most efficient extraction was (i) an HVED pre-treatment at 80kJ/kg with an electrodes distance of 5mm in a liquid-to-solid ratio of 5 followed by (ii) a diffusion with 30% ethanol in water at 60°C for 30min. The highest total polyphenols content reached 2.8±0.4gGAE/100gDM with a corresponding antioxidant activity of 66.8±3.1gTEAC/kgDM. The polyphenols extraction rate increased with temperature in accordance to an Arrhenius type of relationship: activation energy of 21.5±1.1kJ/mol for HVED treated systems against 0.5±0.2kJ/mol for untreated ones.

  19. A Voltage Controller in Photo-Voltaic System with Battery Storage and Applications

    Directory of Open Access Journals (Sweden)

    Rajendra Aparnathi

    2013-12-01

    Full Text Available This paper work is the new voltage controller in photo-voltaic system for Stand-Alone Applications with battery energy storage. The output of the PV array is unregulated DC supply due to change in weather conditions. The maximum power is tracked with respect to temperature and irradiance levels by using DC-DC converter. The perturbation and observes algorithm is applied for maximum power point tracking (MPPT purpose. This algorithm is selected due to its ability to withstand against any parameter variation and having high efficiency. The solar cell array powers the steady state energy and the battery compensates the dynamic energy in the system. The aim of the control strategy is to control the SEPIC converter and bi-direction DC-DC converter to operate in suitable modes according to the condition of solar cell and battery, so as to coordinate the two sources of solar cell and battery supplying power and ensure the system operates with high efficiency and behaviours with good dynamic performance.

  20. Active Power and DC-link Voltage Coordinative Control for Cascaded DC-AC Converter with Bidirectional Power Application

    DEFF Research Database (Denmark)

    Tian, Yanjun; Chen, Zhe; Deng, Fujin;

    2015-01-01

    Two stage cascaded converters are widely used in DC/AC hybrid systems to achieve the bidirectional power transmission. The topology of dual active bridge cascaded with inverter (DABCI) is commonly used in this application. This paper proposes a coordinative control method for DABCI and it’s able...... to reduce the DC-link voltage fluctuation between the DAB and inverter, then reduce the stress on the switching devices, as well as improve the system dynamic performance. In the proposed control method, the DAB and inverter are coordinated to control the DC-link voltage and the power......, and this responsibility sharing control can effectively suppress the impact of the power variation on the DC-link voltage, without sacrificing stability. The proposed control method is also effective for DABCI in unidirectional power transmission. The effectiveness of the propose control has been validated by both...

  1. Modelling and control of a seven level NPC voltage source inverter. Application to high power induction machine drive

    Energy Technology Data Exchange (ETDEWEB)

    Gheraia, H.; Berkouk, E.M. [ENP, Alger (Algeria). Lab. de Commande des Processus; Manesse, G. [CNAM-Paris (France). Lab. d' Electricite Industrielle

    2001-08-01

    In this paper, we study a new kind of continuous-alternating converters: a seven-level neutral point clamping (NPC) voltage source inverter (VSI). We propose this inverter for applications in high voltage and high power fields. In the first part, we develop the knowledge and the control models of this inverter using the connections functions of the semi-conductors. After that, we present two pulse width modulation (PWM) algorithms to control this converter using its control model. We propose these algorithms for digital implementation. This multilevel inverter is associated to the induction machine. The performances obtained are full of promise to use it in the high voltage and high power fields of electrical traction. (orig.)

  2. Protonic/electronic hybrid oxide transistor gated by chitosan and its full-swing low voltage inverter applications

    Energy Technology Data Exchange (ETDEWEB)

    Chao, Jin Yu [Shanxi Province Key Laboratory High Gravity Chemical Engineering, North University of China, Taiyuan 030051 (China); Ningbo Institute of Material Technology and Engineering, Chinese Academy of Sciences, Ningbo 315201 (China); Zhu, Li Qiang, E-mail: lqzhu@nimte.ac.cn; Xiao, Hui [Ningbo Institute of Material Technology and Engineering, Chinese Academy of Sciences, Ningbo 315201 (China); Yuan, Zhi Guo, E-mail: ncityzg@163.com [Shanxi Province Key Laboratory High Gravity Chemical Engineering, North University of China, Taiyuan 030051 (China)

    2015-12-21

    Modulation of charge carrier density in condensed materials based on ionic/electronic interaction has attracted much attention. Here, protonic/electronic hybrid indium-zinc-oxide (IZO) transistors gated by chitosan based electrolyte were obtained. The chitosan-based electrolyte illustrates a high proton conductivity and an extremely strong proton gating behavior. The transistor illustrates good electrical performances at a low operating voltage of ∼1.0 V such as on/off ratio of ∼3 × 10{sup 7}, subthreshold swing of ∼65 mV/dec, threshold voltage of ∼0.3 V, and mobility of ∼7 cm{sup 2}/V s. Good positive gate bias stress stabilities are obtained. Furthermore, a low voltage driven resistor-loaded inverter was built by using an IZO transistor in series with a load resistor, exhibiting a linear relationship between the voltage gain and the supplied voltage. The inverter is also used for decreasing noises of input signals. The protonic/electronic hybrid IZO transistors have potential applications in biochemical sensors and portable electronics.

  3. Envirobiosens. New trends in bio-sensing for environmental applications

    Energy Technology Data Exchange (ETDEWEB)

    Alcock, S. [Cranfield Biothechnology Centre, Cranfield University (United Kingdom); Cosnier, S. [Universite Joseph-Fourier, Grenoble I, Lab. d' Electrochimie Organique et de Photochimie Redox, UMR CNRS 5630, 38 (France); Magner, E. [Limerick University, Dept. of Chemical and Environmental Sciences (Ireland)] [and others

    2000-07-01

    The development of useful sensor systems to monitor multiple pollutants is needed for many environmental applications like the pollution monitoring and processing. The advantages of chemical sensors, bio-sensors and bio-mimetic systems should be exploited to fill specific niche applications in environmental engineering. Sensors offer particular advantages as they can be used for rapid field assessment of pollution risks, including the effects of pollutant mixtures. This conference reviews the current state of the art for bio-sensors operating in the environment and in environmental processes to develop bio-sensors practical applications in the environmental technology. The papers are presented in three parts: enzymatic sensors for environmental monitoring; affinity sensors for environmental application; cell and tissue sensors for environmental analysis, future prospects. (A.L.B.)

  4. High Voltage Bidirectional Flyback Converter Driving DEAP Actuator for Automotive Applications

    DEFF Research Database (Denmark)

    Huang, Lina; Zhang, Zhe; Andersen, Michael A. E.;

    2013-01-01

    DEAP (Dielectric Electro Active Polymer) is a new type of smart material. The actuator based on DEAP material tends to be applied in a variety of occasions. It will have prosperous future when employed in automotive field. This paper is focused on the design and implementation of a low input volt...... voltage and high output voltage bidirectional converter for driving the DEAP actuator. The detailed design and implemented parameters have been summarized, especially for the high voltage transformer. The experiments have been performed to validate the design and implementation....

  5. CONTEMPORARY ENVIRONMENTAL APPLICATIONS OF PHOTOGRAPHIC INTERPRETATION

    Science.gov (United States)

    Aerial Photographic Interpretation is a timed-tested technique for extracting landscape- level information from aerial photographs and other types of remotely sensed images. The U.S. Environmental Protection Agency's Environmental Photographic Interpretation Center (EPIC) has a 2...

  6. Modeling Environmental Concern: Theory and Application.

    Science.gov (United States)

    Hackett, Paul M. W.

    1993-01-01

    Human concern for the quality and protection of the natural environment forms the basis of successful environmental conservation activities. Considers environmental concern research and proposes a model that incorporates the multiple dimensions of research through which environmental concern may be evaluated. (MDH)

  7. Application of Cat Swarm Optimization in testing Static Load Models for Voltage Stability

    Directory of Open Access Journals (Sweden)

    G. Naveen Kumar

    2016-03-01

    Full Text Available Power System Load Modeling is a method which is used to model the power system and essential for voltage stability studies. Voltage stability defines the ability of a power network to maintain steady state voltages at all the buses under normal operating conditions, and when subjected to a disturbance. The research presented as part of this paper, deals with analysis of different static load models for voltage stability studies. The precision of the results are directly related to the load models used in this analysis. The method is analyzed using continuation power flow routine. Flexible AC Transmission System technology with a combination of Cat Swarm Optimization Meta Heuristic Search approach is applied to give a solution for the problem of instability. The effectiveness of the proposed method is demonstrated through quantitative simulation on standard IEEE 14 bus system for contingency condition.

  8. Voltage controlled modification of flux closure domains in planar magnetic structures for microwave applications

    Energy Technology Data Exchange (ETDEWEB)

    Parkes, D. E.; Beardsley, R.; Edmonds, K. W.; Campion, R. P.; Gallagher, B. L.; Rushforth, A. W., E-mail: Stuart.Cavill@york.ac.uk, E-mail: Andrew.Rushforth@nottingham.ac.uk [School of Physics and Astronomy, The University of Nottingham, Nottingham NG7 2RD (United Kingdom); Bowe, S. [School of Physics and Astronomy, The University of Nottingham, Nottingham NG7 2RD (United Kingdom); Diamond Light Source, Chilton, Didcot, Oxfordshire OX11 0DE (United Kingdom); Isakov, I.; Warburton, P. A. [London Centre of Nanotechnology, University College London, London WC1H 0AH (United Kingdom); Cavill, S. A., E-mail: Stuart.Cavill@york.ac.uk, E-mail: Andrew.Rushforth@nottingham.ac.uk [Department of Physics, University of York, Heslington, York YO10 5DD (United Kingdom); Diamond Light Source, Chilton, Didcot, Oxfordshire OX11 0DE (United Kingdom)

    2014-08-11

    Voltage controlled modification of the magnetocrystalline anisotropy in a hybrid piezoelectric/ferromagnet device has been studied using Photoemission Electron Microscopy with X-ray magnetic circular dichroism as the contrast mechanism. The experimental results demonstrate that the large magnetostriction of the epitaxial Fe{sub 81}Ga{sub 19} layer enables significant modification of the domain pattern in laterally confined disc structures. In addition, micromagnetic simulations demonstrate that the strain induced modification of the magnetic anisotropy allows for voltage tuneability of the natural resonance of both the confined spin wave modes and the vortex motion. These results demonstrate the possibility for using voltage induced strain in low-power voltage tuneable magnetic microwave oscillators.

  9. Study of the plasma interference with high voltage electrode array for space power application

    OpenAIRE

    Iwasa, Minoru; TANAKA, KOJI; Sasaki, Susumu; ODAWARA, OSAMU; 岩佐 稔; 田中 孝治; 佐々木 進; 小田原 修

    2005-01-01

    We are studying the problems associated with high voltage power systems in space. Especially we are interested in the potential distribution of the solar array that is resistant to the electrical discharge. We have carried out experiments on the interaction between the high voltage solar array and the ambient plasma. In the experiment, an array of electrodes distributed on the insulation panel was used to simulate the inter-connectors of the solar array. An electrode array without the insulat...

  10. Environmental Green Chemistry Applications of Nanoporous Carbons

    Energy Technology Data Exchange (ETDEWEB)

    Matos, J.; Garcia, A; Poon, P

    2010-01-01

    Influence of surface properties of nanoporous carbons on activity and selectivity during the photooxidation of 4-chlorophenol on UV-irradiated TiO{sub 2} was performed. Characterization by infrared spectroscopy, X-ray photoelectronic spectroscopy and X-ray absorption near edge structure spectroscopy confirm the presence of a contact interface between both solids and suggest the coordination of some functional organic groups of the carbon surface, mainly ethers and carboxylic acids, to metallic centre Ti{sup +4} in TiO{sub 2}. Changes in surface pH of carbons from basic to neutral or acid remarkably increase the production of 4-chlorocathecol by a factor of 22 on TiO{sub 2}-Carbon in comparison of TiO{sub 2} alone. A scheme of interaction between TiO{sub 2} and carbon is proposed to the increased photoactivity of TiO{sub 2} and a reaction mechanism for the different intermediate products detected is also proposed. Results showed that TiO{sub 2}-Carbon can be used as an alternative photocatalyst for environmental green chemistry and selective organic synthesis applications.

  11. Inverter-Based Low-Voltage CCII- Design and Its Filter Application

    Directory of Open Access Journals (Sweden)

    Y. S. Hwang

    2013-12-01

    Full Text Available This paper presents a negative type second-generation current conveyor (CCII-. It is based on an inverter-based low-voltage error amplifier, and a negative current mirror. The CCII- could be operated in a very low supply voltage such as ±0.5V. The proposed CCII- has wide input voltage range (±0.24V, wide output voltage (±0.24V and wide output current range (±24mA. The proposed CCII- has no on-chip capacitors, so it can be designed with standard CMOS digital processes. Moreover, the architecture of the proposed circuit without cascoded MOSFET transistors is easily designed and suitable for low-voltage operation. The proposed CCII- has been fabricated in TSMC 0.18μm CMOS processes and it occupies 1189.91 x 1178.43μm2 (include PADs. It can also be validated by low voltage CCII filters.

  12. Industrial Application Of Environmentally Conscious Design

    DEFF Research Database (Denmark)

    McAloone, Timothy Charles

    This book is an adaptation of the author’s PhD thesis, in which he explored environmentally conscious design in the electrical/electronics industry sector. In this new and rapidly evolving field, existing research has not yet sought to understand the causes of success and the problems experienced...... when companies have integrated environmental considerations into the design process.In the context of advanced practitioners of environmentally conscious design in the Western European and North American electrical/electronics industry sector, it is shown that:- the timing of environmental decisions...... in the design process is key to environmentally conscious design;- the environmental profile of a product is affected the most in the very early stages of the design process, particularly in the pre-specification stage, where tools for environmentally conscious design decision-making are lacking...

  13. Environmentally friendly power sources for aerospace applications

    Science.gov (United States)

    Lapeña-Rey, Nieves; Mosquera, Jonay; Bataller, Elena; Ortí, Fortunato; Dudfield, Christopher; Orsillo, Alessandro

    One of the crucial challenges of the aviation industry in upcoming years is to reduce emissions not only in the vicinity of airfields but also in cruise. Amongst other transport methods, airplanes emissions count for 3% of the CO 2 emissions. Initiatives to reduce this include not only investing in more fuel-efficient aircrafts or adapting existing ones to make them more efficient (e.g. by fitting fuel-saving winglets), but also more actively researching novel propulsion systems that incorporate environmentally friendly technologies. The Boeing Company through its European subsidiary, Boeing Research and Technology Europe (BR&TE) in collaboration with industry partners throughout Europe is working towards this goal by studying the possible application of advanced batteries and fuel-cell systems in aeronautical applications. One example is the development of a small manned two-seater prototype airplane powered only by proton exchange membrane (PEM) fuel-cell stacks, which runs on compressed hydrogen gas as fuel and pressurized air as oxidant, and Li-ion batteries. The efficient all composite motorglider is an all electric prototype airplane which does not produce any of the noxious engine exhaust by-products, such as carbon dioxide, carbon monoxide or NO x, that can contribute to climate change and adversely affect local air quality. Water and heat are the only exhaust products. The main objective is to demonstrate for the first time in aviation history a straight level manned flight with fuel-cells as the only power source. For this purpose, the original engine of a super Dimona HK36TTC glider from Diamond Aircraft Industries (Austria) was replaced by a hybrid power system, which feeds a brushless dc electrical motor that rotates a variable pitch propeller. Amongst the many technical challenges encountered when developing this test platform are maintaining the weight and balance of the aircraft, designing the thermal management system and the power management

  14. Environmentally friendly power sources for aerospace applications

    Energy Technology Data Exchange (ETDEWEB)

    Lapena-Rey, Nieves; Mosquera, Jonay; Bataller, Elena; Orti, Fortunato [Boeing Research and Technology Europe Ltd., Environmental Technologies, C/ Canada Real de las Merinas 1-3, Building 4, 4th floor, Madrid 28042 (Spain); Dudfield, Christopher; Orsillo, Alessandro [Intelligent Energy Ltd., The Innovation Centre, Epinal Way, Loughborough LE11 3EH (United Kingdom)

    2008-07-01

    One of the crucial challenges of the aviation industry in upcoming years is to reduce emissions not only in the vicinity of airfields but also in cruise. Amongst other transport methods, airplanes emissions count for 3% of the CO{sub 2} emissions. Initiatives to reduce this include not only investing in more fuel-efficient aircrafts or adapting existing ones to make them more efficient (e.g. by fitting fuel-saving winglets), but also more actively researching novel propulsion systems that incorporate environmentally friendly technologies. The Boeing Company through its European subsidiary, Boeing Research and Technology Europe (BR and TE) in collaboration with industry partners throughout Europe is working towards this goal by studying the possible application of advanced batteries and fuel-cell systems in aeronautical applications. One example is the development of a small manned two-seater prototype airplane powered only by proton exchange membrane (PEM) fuel-cell stacks, which runs on compressed hydrogen gas as fuel and pressurized air as oxidant, and Li-ion batteries. The efficient all composite motorglider is an all electric prototype airplane which does not produce any of the noxious engine exhaust by-products, such as carbon dioxide, carbon monoxide or NOx, that can contribute to climate change and adversely affect local air quality. Water and heat are the only exhaust products. The main objective is to demonstrate for the first time in aviation history a straight level manned flight with fuel-cells as the only power source. For this purpose, the original engine of a super Dimona HK36TTC glider from Diamond Aircraft Industries (Austria) was replaced by a hybrid power system, which feeds a brushless dc electrical motor that rotates a variable pitch propeller. Amongst the many technical challenges encountered when developing this test platform are maintaining the weight and balance of the aircraft, designing the thermal management system and the power

  15. Successful application of Low Voltage Electron Microscopy to practical materials problems

    Energy Technology Data Exchange (ETDEWEB)

    Bell, David C., E-mail: dcb@seas.harvard.edu [School of Engineering and Applied Sciences, Harvard University, Cambridge, MA (United States); Center for Nanoscale Systems, Harvard University, Cambridge, MA (United States); Mankin, Max; Day, Robert W. [Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA (United States); Erdman, Natasha [JEOL USA Inc. Peabody, MA (United States)

    2014-10-15

    Low-voltage High-Resolution Electron Microscopy (LVHREM) has several advantages, including increased cross-sections for inelastic and elastic scattering, increased contrast per electron, decreased delocalization effects and reduced knock-on damage. Imaging at differing voltages has shown advantages for imaging materials that are knock-on damage sensitive. We show experimentally that different materials systems benefit from low voltage high-resolution microscopy. There are advantages for imaging single layer materials such as graphene at below the knock-on threshold; we present an example of imaging a graphene sheet at 40 kV. We have also examined mesoporous silica decorated with Pd nanoparticles and carbon black functionalized with Pd/Pt nanoparticles. In these cases we show that the lower voltage imaging maintains the structure of the surrounding matrix during imaging, whereas aberration correction provides the higher resolution for imaging the nanoparticle lattice. Perhaps surprisingly we show that zeolites damage preferentially by ionization effects (radiolysis). The current literature suggests that below incident energies of 40 kV the damage is mainly radiolitic, whereas at incident energies above 200 kV the knock-on damage and material sputtering will be the dominant effect. Our experimental observations support this conclusion and the effects we have observed at 40 kV are not indicative of knock-on damage. Other nanoscale materials such as thin silicon nanowires also benefit from lower voltage imaging. LVHREM imaging provides an excellent option to avoid beam damage to nanowires; our results suggest that LVHREM is suitable for nanowire-biological composites. Our experimental observations serve as a clear demonstration that even at 40 keV accelerating voltage, LVHREM can be used without inducing beam damage to locate dislocations and other crystalline defects, which may have adverse effects on nanowire device performance. Low voltage operation will likely

  16. Environmental applications of chitosan and its derivatives.

    Science.gov (United States)

    Yong, Soon Kong; Shrivastava, Manoj; Srivastava, Prashant; Kunhikrishnan, Anitha; Bolan, Nanthi

    2015-01-01

    Chitosan originates from the seafood processing industry and is one of the most abundant of bio-waste materials. Chitosan is a by-product of the alkaline deacetylation process of chitin. Chemically, chitosan is a polysaccharide that is soluble in acidic solution and precipitates at higher pHs. It has great potential for certain environmental applications, such as remediation of organic and inorganic contaminants, including toxic metals and dyes in soil, sediment and water, and development of contaminant sensors. Traditionally, seafood waste has been the primary source of chitin. More recently, alternative sources have emerged such as fungal mycelium, mushroom and krill wastes, and these new sources of chitin and chitosan may overcome seasonal supply limitations that have existed. The production of chitosan from the above-mentioned waste streams not only reduces waste volume, but alleviates pressure on landfills to which the waste would otherwise go. Chitosan production involves four major steps, viz., deproteination, demineralization, bleaching and deacetylation. These four processes require excessive usage of strong alkali at different stages, and drives chitosan's production cost up, potentially making the application of high-grade chitosan for commercial remediation untenable. Alternate chitosan processing techniques, such as microbial or enzymatic processes, may become more cost-effective due to lower energy consumption and waste generation. Chitosan has proved to be versatile for so many environmental applications, because it possesses certain key functional groups, including - OH and -NH2 . However, the efficacy of chitosan is diminished at low pH because of its increased solubility and instability. These deficiencies can be overcome by modifying chitosan's structure via crosslinking. Such modification not only enhances the structural stability of chitosan under low pH conditions, but also improves its physicochemical characteristics, such as porosity

  17. Modularized Three-Phase Semiconductor Transformer with Bidirectional Power Flow for Medium Voltage Application

    Directory of Open Access Journals (Sweden)

    Do-Hyun Kim

    2016-08-01

    Full Text Available This paper describes a prototype of modularized three-phase semiconductor transformer that was developed in the lab for feasibility study. The developed prototype is composed of three units of single-phase semiconductor transformer coupled in Y-connection. Each single-phase unit has multiple units of high-voltage high-frequency resonant AC–DC converter, a low-voltage hybrid-switching DC–DC converter, and a low-voltage hybrid-switching DC–AC inverter. Also, each single-phase unit has two digital signal processor (DSP boards to control converter operation and to acquire monitoring data. The monitoring system was developed based on LabView by using controller area network (CAN communication between the DSP board and the personal computer (PC. Through diverse experimental analyses it was verified that the prototype operates with proper performance under normal and sag conditions. The developed prototype confirms the possibility of fabricating a commercial high-voltage high-power semiconductor transformer by increasing the number of series-connected converter modules in high-voltage side and improving the system efficiency with a new switching device such as an SiC device.

  18. Activate distributed energy resources' services: Hierarchical voltage controller as an application

    DEFF Research Database (Denmark)

    Han, Xue; Kosek, Anna Magdalena; Gehrke, Oliver

    2014-01-01

    The flexibilities from controllable distributed energy resources (DERs) offer the opportunities to mitigate some of the operation problems in the power distribution grid. The provision of system services requires the aggregation and coordination of their flexibilities, in order to obtain the flex...... the efficient aggregation and dispatch, and it simplifies the optimization complexity; the involvement of DER flexibilities in voltage services can significantly improve the voltage quality and reduce the grid power loss without additional regulating devices....... the flexible capacity of large scale. In this paper, a hierarchical controller is presented to activate the aggregation, and tries to obtain a global optimum of the grid operation. A distribution grid with large penetration of highly varying generation or load is under the risk that the voltage quality...... delivered to the end users is very poor. Hence, a coordinated voltage control function is investigated given such control hierarchy utilizing the flexibilities from the DER units to obtain an optimal voltage profile along the distribution feeder. The results are two folded: the controller enables...

  19. Application of carbon nanotube hold-off voltage for determining gas composition

    Science.gov (United States)

    Schipper, John F. (Inventor); Li, Jing (Inventor)

    2009-01-01

    Method and system for determining chemical composition of a single-component or multiple-component gas, using a discharge holdoff mechanism. A voltage difference V between two spaced apart electrodes is brought to a selected value and held, the holdoff time interval .DELTA.t(V;ho) required before gas discharge occurs is measured, and the associated electrical current or cumulative electrical charge is measured. As the voltage difference V increases, the time interval length .DELTA.t(V;ho) decreases monotonically. Particular voltage values, V.sub..infin. and V.sub.0, correspond to initial appearance of discharge (.DELTA.t.apprxeq..infin.) and prompt discharge (.DELTA.t.apprxeq.0). The values V.sub..infin. and V.sub.0 and the rate of decrease of .DELTA.t(V;ho) and/or the rate of increase of current or cumulative charge with increasing V are characteristic of one or more gas components present.

  20. Solid-state fast voltage compensator for pulsed power applications requiring constant AC power consumption

    CERN Document Server

    Magallanes, Francisco Cabaleiro; Viarouge, Philippe; Cros, Jérôme

    2015-01-01

    This paper proposes a novel topological solution for pulsed power converters based on capacitor-discharge topologies, integrating a Fast Voltage Compensator which allows an operation at constant power consumption from the utility grid. This solution has been retained as a possible candidate for the CLIC project under study at CERN, which requires more than a thousand synchronously-operated klystron modulators producing a total pulsed power of almost 40 GW. The proposed Fast Voltage Compensator is integrated in the modulator such that it only has to treat the capacitor charger current and a fraction of the charging voltage, meaning that its dimensioning power and cost are minimized. This topology can be used to improve the AC power quality of any pulsed converters based on capacitor-discharge concept. A prototype has been built and exploited to validate the operating principle and demonstrate the benefits of the proposed solution.

  1. Shunt PWM advanced var compensators based on voltage source inverters for Facts applications

    Energy Technology Data Exchange (ETDEWEB)

    Barbosa, Pedro G.; Misaka, Isamu; Watanabe, Edson H. [Universidade Federal, Rio de Janeiro, RJ (Brazil). Coordenacao dos Programas de Pos-graduacao de Engenharia

    1994-12-31

    Increased attention has been given to improving power system operation. This paper presents modeling, analysis and design of reactive shunt power compensators based on PWM-Voltage Source Inverters (Pulse Width Modulation -Voltage Source Inverters). (Pulse Width Modulation - Voltage Source Inverters). The control algorithm is based on new concepts of instantaneous active and reactive power theory. The objective is to show that with a small capacitor in the side of a 3-phase PWM-VSI it is possible to synthesize a variable reactive (capacitive or inductive) device. Design procedures and experimental results are presented. The feasibility of this method was verified by digital simulations and measurements on a small scale model. (author) 9 refs., 12 figs.

  2. Bidirectional Flyback Converter with Multiple Series Connected Outputs for High Voltage Capacitive Charge and Discharge Applications

    DEFF Research Database (Denmark)

    Thummala, Prasanth; Schneider, Henrik; Zhang, Zhe

    2015-01-01

    This paper evaluates two different implementations of a bidirectional flyback converter for driving a capacitive electro active actuator, which must be charged and discharged from 0 V to 2.5 kV DC and vice versa, supplied from a 24 V battery. In one implementation, a high voltage MOSFET (4 k...... by lower voltage rating MOSFETs driven by a gate drive transformer. Simulation results to compare the operation of conventional and proposed converters are provided. The advantages of proposed implementation are improved energy efficiency and lower cost. Experimental results with two series connected...

  3. A DC-DC Converter with Wide Input Voltage Range for Fuel Cell and Supercapacitor Application

    DEFF Research Database (Denmark)

    Zhang, Zhe; Thomsen, Ole Cornelius; Andersen, Michael Andreas E.

    2009-01-01

    This paper proposes a novel phase-shift plus duty cycle controlled hybrid bi-directional DC-DC converter based on fuel cells and supercapacitors. The described converter employs two high frequency transformers to couple the half-bridge and full-bridge circuits together in the primary side...... and voltage doubler circuit in secondary side. Boost type converter can limit the output ripple current of the fuel cells; hybrid full-bridge structure can change operating modes according to the different input voltage; phase-shift with duty cycle control scheme is utilized to control the bidirectional power...

  4. Derivation and application of sensitivities to assess transient voltage sags caused by rotor swings

    DEFF Research Database (Denmark)

    Weckesser, Johannes Tilman Gabriel; Jóhannsson, Hjörtur; Østergaard, Jacob;

    2015-01-01

    The paper introduces an approach to investigate voltage sags, which are caused by large generator rotor swings following a transient disturbance. Therefore, the method exploits sensitivities derived from the algebraic network equations. These provide information on the impact of a generator on th...

  5. Optimization of Bi-Directional Flyback Converter for a High Voltage Capacitor Charging Application

    DEFF Research Database (Denmark)

    Thummala, Prasanth; Schneider, Henrik; Zhang, Zhe

    2014-01-01

    a 24 V battery. The proposed optimization routine sweeps through a database of low voltage switching devices, and transformer core types and sizes. For each core, important winding parameters such as, the vertical winding space allocation for primary and secondary windings, and the spacing between...

  6. A Low-Voltage and Low-Power Programmable "G" _"m" "-C" Filter for Wireless Applications

    Directory of Open Access Journals (Sweden)

    Amir Baghi Rahin

    2014-10-01

    Full Text Available In this paper, a low voltage and low power (LV/LP Operational Transconductance Amplifier (OTA using FGMOS (Floating-Gate MOS transistor is proposed. The relative tuning range of 50 is achieved in this OTA while only consumes 40 µW with 1.0 V supply voltage in TSMC 0.18 µm CMOS technology. The simulation results of the proposed OTA show an open loop gain of 30.2 dB and a unity gain frequency of 942 MHz. In comparison with previous works, the proposed OTA, with lower supply voltage, is provided the better frequency performance, higher output voltage swing, better linearity and lower power consumption. The proposed OTA is used in the second-order filter to show a good tuning range from 100 kHz to 5.6 MHz which is suitable for the wireless specifications of Bluetooth (650 kHz,CDMA2000 (700 kHz and Wideband CDMA (2.2 MHz. The active area occupied by the designed filter on silicon is 192μm×535μm.

  7. Bidirectional Flyback Converter with Multiple Series Connected Outputs for High Voltage Capacitive Charge and Discharge Applications

    DEFF Research Database (Denmark)

    Thummala, Prasanth; Schneider, Henrik; Zhang, Zhe;

    2015-01-01

    This paper evaluates two different implementations of a bidirectional flyback converter for driving a capacitive electro active actuator, which must be charged and discharged from 0 V to 2.5 kV DC and vice versa, supplied from a 24 V battery. In one implementation, a high voltage MOSFET (4 kV) in...

  8. A new way of estimating compute-boundedness and its application to dynamic voltage scaling

    DEFF Research Database (Denmark)

    Venkatachalam, Vasanth; Franz, Michael; Probst, Christian W.

    2007-01-01

    Many dynamic voltage scaling algorithms rely on measuring hardware events (such as cache misses) for predicting how much a workload can be slowed down with acceptable performance loss. The events measured, however, are at best indirectly related to execution time and clock frequency. By relating...

  9. Charge-sharing SAR ADCs for low-voltage low-power applications

    CERN Document Server

    Rabuske, Taimur

    2017-01-01

    This book introduces readers to the potential of charge-sharing (CS) successive approximation register (SAR) analog-to-digital converters (ADCs), while providing extensive analysis of the factors that limit the performance of the CS topology. The authors present guidelines and useful techniques for mitigating the limitations of the architecture, while focusing on the implementation under restricted power budgets and voltage supplies.

  10. Low-Cost Voltage Zero-Crossing Detector for AC-Grid Applications

    Directory of Open Access Journals (Sweden)

    Vorobyov Maxim

    2014-10-01

    Full Text Available Renewable energy sources and energy storage devices are becoming more popular. Some of them like small hydropower turbines, wind turbines and diesel generators produce AC voltage with different frequency and voltage than the main grid. For them power electronics converters are necessary. Power electronics converters presented in industry use two or three level energy conversion, although direct AC to AC converters exist, but one of the main problems is the switch commutation when current or voltage is crossing the zero point. Zero crossing sensors are used to solve this problem. They consist of current or voltage measurement unit and zero crossing detector. Different approaches are used for zero crossing: hardware or software. Hardware approach is simple but it has low precision. Software approach has high precision but it is complicated and expensive. In this paper a simple low cost high precision approach is presented. It takes all advantages from both approaches. While tested with two types of microcontrollers the precision of experimental measurement is 25 μs - 40 μs.

  11. Effective description of tunneling in a time-dependent potential with applications to voltage switching in Josephson junctions

    DEFF Research Database (Denmark)

    Andersen, Christian Kraglund; Mølmer, Klaus

    2013-01-01

    We propose to use a time-dependent imaginary potential to describe quantum mechanical tunneling through time-varying potential barriers. We use Gamow solutions for stationary tunneling problems to justify our choice of potential, and we apply our method to describe tunneling of a mesoscopic quantum...... variable: the phase change across a Josephson junction. The Josephson junction phase variable behaves as the position coordinate of a particle moving in a tilted washboard potential, and our general solution to the motion in such a potential with a time-dependent tilt reproduces a number of features...... associated with voltage switching in Josephson junctions. Apart from applications as artificial atoms in quantum information studies, the Josephson junction may serve as an electric field sensitive detector, and our studies provide a detailed understanding of how the voltage switching dynamics couples...

  12. Effective description of tunneling in a time-dependent potential with applications to voltage switching in Josephson junctions

    DEFF Research Database (Denmark)

    Andersen, Christian Kraglund; Mølmer, Klaus

    2013-01-01

    variable: the phase change across a Josephson junction. The Josephson junction phase variable behaves as the position coordinate of a particle moving in a tilted washboard potential, and our general solution to the motion in such a potential with a time-dependent tilt reproduces a number of features......We propose to use a time-dependent imaginary potential to describe quantum mechanical tunneling through time-varying potential barriers. We use Gamow solutions for stationary tunneling problems to justify our choice of potential, and we apply our method to describe tunneling of a mesoscopic quantum...... associated with voltage switching in Josephson junctions. Apart from applications as artificial atoms in quantum information studies, the Josephson junction may serve as an electric field sensitive detector, and our studies provide a detailed understanding of how the voltage switching dynamics couples...

  13. Ultra-Low-Voltage Self-Body Biasing Scheme and Its Application to Basic Arithmetic Circuits

    Directory of Open Access Journals (Sweden)

    Ramiro Taco

    2015-01-01

    Full Text Available The gate level body biasing (GLBB is assessed in the context of ultra-low-voltage logic designs. To this purpose, a GLBB mirror full adder is implemented by using a commercial 45 nm bulk CMOS triple-well technology and compared to equivalent conventional zero body-biased CMOS and dynamic threshold voltage MOSFET (DTMOS circuits under different running conditions. Postlayout simulations demonstrate that, at the parity of leakage power consumption, the GLBB technique exhibits a significant concurrent reduction of the energy per operation and the delay in comparison to the conventional CMOS and DTMOS approaches. The silicon area required by the GLBB full adder is halved with respect to the equivalent DTMOS implementation, but it is higher in comparison to conventional CMOS design. Performed analysis also proves that the GLBB solution exhibits a high level of robustness against temperature fluctuations and process variations.

  14. Voltage-induced material removal mechanism of copper for electrochemical-mechanical polishing applications

    Institute of Scientific and Technical Information of China (English)

    Sang-Jun HAN; Yong-Jin SEO

    2009-01-01

    The current-voltage (Ⅰ-Ⅴ) curves, such as linear sweep voltammetry (LSV) and cyclic voltammetry (CV), were employed to evaluate the effect of electrolyte concentration on the electrochemical reaction trend. From the Ⅰ-Ⅴ curve, the electrochemical states of active, passive, transient and trans-passive region could be characterized. And then, the mechanism of the process of voltage-induced material removal in electrochemical mechanical polishing (ECMP) of copper was investigated. Scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS) analyses were used to observe the surface profile. Finally, the oxidation and reduction processes of the Cu surface were monitored by the repetition of anodic and cathodic potential from cyclic voltammetry (CV) method in acid- and alkali-based electrolyte.

  15. On the application of radio frequency voltages to ion traps via helical resonators

    CERN Document Server

    Siverns, J D; Weidt, S; Hensinger, W K

    2011-01-01

    Ions confined using a Paul trap require a stable, high voltage and low noise radio frequency (RF) potential. We present a guide for the design and construction of a helical coil resonator for a desired frequency that maximises the quality factor for a set of experimental constraints. We provide an in-depth analysis of the system formed from a shielded helical coil and an ion trap by treating the system as a lumped element model. This allows us to predict the resonant frequency and quality factor in terms of the physical parameters of the resonator and the properties of the ion trap. We also compare theoretical predictions with experimental data for different resonators, and predict the voltage applied to the ion trap as a function of the Q-factor, input power and the properties of the resonant circuit.

  16. SiC merged p-n/Schottky rectifiers for high voltage applications

    Energy Technology Data Exchange (ETDEWEB)

    Held, R.; Kaminski, N.; Niemann, E. [Daimler-Benz AG, Frankfurt am Main (Germany). Forschung und Technik

    1998-08-01

    A method of reducing reverse currents and increasing breakdown voltages without inducing negative effects on switching behavior in silicon carbide Schottky diodes is proved successfully. Implantation of p-regions in the surface of the n-drift region below the Schottky metal form face to face p-n junctions which screen the Schottky contact from high electrical fields. This results in a reduction of the reverse current and an increase of the breakdown voltage to the limit of a `pure` SiC p-n diode. It is shown, that in contrast to silicon based devices, SiC merged p-n/Schottky (MPS) rectifier preserve their excellent unipolar switching behavior. (orig.) 5 refs.

  17. A Sufficient Condition for Power Flow Insolvability with Applications to Voltage Stability Margins

    CERN Document Server

    Molzahn, Daniel K; DeMarco, Christopher L

    2012-01-01

    For the nonlinear power flow problem specified with standard PQ, PV, and slack bus equality constraints, we present a sufficient condition under which the specified set of nonlinear algebraic equations has no solution. This sufficient condition is constructed in a framework of an associated feasible, convex optimization problem. The objective employed in this optimization problem yields a measure of distance (in a parameter set) to the power flow solution boundary. In practical terms, this distance is closely related to quantities that previous authors have proposed as voltage stability margins. A typical margin is expressed in terms of the parameters of system loading (injected powers); here we additionally introduce a new margin in terms of the parameters of regulated bus voltages.

  18. Agricultural and Environmental Informatics, Governance and Management: Emerging Research Applications

    NARCIS (Netherlands)

    Andreopoulou, Z.; Manos, B.; Polman, N.B.P.; Viaggi, D.

    2011-01-01

    Agricultural and Environmental Informatics, Governance and Management: Emerging Research Applications is a state-of-the-art reference book which explores how rural policymakers and stakeholders can use information and communication technologies to sustainably manage agricultural and natural resource

  19. DRIFT-ARID: Application of a method for environmental water ...

    African Journals Online (AJOL)

    DRIFT-ARID: Application of a method for environmental water requirements ... of water required (EWR) to sustain ecosystem services in non-perennial rivers need ... river types, especially episodic rivers where data are scarce or non-existent.

  20. Modelling of Electrokinetic Processes in Civil and Environmental Engineering Applications

    DEFF Research Database (Denmark)

    Paz-Garcia, Juan Manuel; Johannesson, Björn; Ottosen, Lisbeth M.

    2011-01-01

    A mathematical model for the electrokinetic phenomena is described. Numerical simulations of different applications of electrokinetic techniques to the fields of civil and environmental engineering are included, showing the versatility and consistency of the model. The electrokinetics phenomena...

  1. Applications of passive remote surface acoustic wave sensors in high-voltage systems; Einsatz von passiven funkabfragbaren Oberflaechenwellensensoren in der elektrischen Energietechnik

    Energy Technology Data Exchange (ETDEWEB)

    Teminova, R.

    2007-06-29

    Passive remote Surface Acoustic Wave (SAW) sensors have been applied e.g. as temperature, pressure or torque sensors. Their important advantages over standard methods are their passive operating principle, which allows operation without any power supply, as well as the wireless high-frequency signal transmission over distances up to about 10..15 m even through (non metallic) housings. These properties of SAW sensors particularly qualify them for applications in high voltage operational equipment. First experience was gained in a long time field test of surge arrester monitoring based on SAW temperature sensors in a German high-voltage substation. Now, this system has been further developed at Darmstadt University of Technology for other applications, the first of them being an overhead line (OHL) conductor temperature measurement, the second one a temperature monitoring system for of high-voltage disconnectors. After designing and building the sensors, extensive laboratory tests were carried out applying high-voltage, high-current and thermal stress in order to approve the suitability for the intended application. All these tests confirmed the assumption that SAW sensors, due to their passive working principle, are not affected at all by any kind of electrical, magnetic or thermal stress that may occur during service. The complete temperature sensor consists of three parts: a sensor chip, an antenna which receives and transmits the signal from and to the radar unit and a body for installation and for protection against environmental impact. One must find a good compromise between optimizing of thermal, dielectric and high-frequency characteristics and at the same time taking into consideration a simple installation. These requirements on the SAW sensors turned out to be difficult to coordinate. To achieve a high measuring precision is especially difficult. First, a new sensor for OHL application was developed. The OHL conductor temperature sensor had been optimized

  2. Development and Applications of discharges generated in liquids with short high voltage pulses

    Science.gov (United States)

    Kolb, Juergen; Miron, Camelia; Kruth, Angela; Balcerak, Michal; Bonislawski, Michal; Holub, Marcin

    2016-09-01

    Discharges that are generated within a liquid have been of scientific interest for more than a century. The possibility for a breakdown development that is not mediated by an initial gaseous phase is still disputed. In this respect are especially discharges that are instigated with short high voltage pulses calling for attention. Associated with this specific excitation scheme is a change in plasma development, plasma parameters and reaction mechanisms in the liquid. We have compared discharges in a point-to-plane geometry that were generated with 50-us or 10-ns high voltage pulses. Time-resolved shadowgraphy and spectroscopy were performed to evaluate discharge structures, plasma parameter and reactive species that were formed in distilled water or ethanol. Different propagation modes, with velocities of 6.7 km/s for tree-like streamers and only 50 m/s for bush-like streamers, were observed. Optical emission spectroscopy has shown the formation of molecular bands of nitrogen, as well as strongly broadened atomic hydrogen and oxygen, which are likely to be responsible for the observed surface modifications of polymers. With nanosecond high voltage pulses we found an increase of unsaturated bondings for polyimide surfaces that were exposed in the discharge volume.

  3. Compact high voltage, high peak power, high frequency transformer for converter type modulator applications.

    Science.gov (United States)

    Reghu, T; Mandloi, V; Shrivastava, Purushottam

    2016-04-01

    The design and development of a compact high voltage, high peak power, high frequency transformer for a converter type modulator of klystron amplifiers is presented. The transformer has been designed to operate at a frequency of 20 kHz and at a flux swing of ±0.6 T. Iron (Fe) based nanocrystalline material has been selected as a core for the construction of the transformer. The transformer employs a specially designed solid Teflon bobbin having 120 kV insulation for winding the high voltage secondary windings. The flux swing of the core has been experimentally found by plotting the hysteresis loop at actual operating conditions. Based on the design, a prototype transformer has been built which is per se a unique combination of high voltage, high frequency, and peak power specifications. The transformer was able to provide 58 kV (pk-pk) at the secondary with a peak power handling capability of 700 kVA. The transformation ratio was 1:17. The performance of the transformer is also presented and discussed.

  4. Industrial Application Of Environmentally Conscious Design

    DEFF Research Database (Denmark)

    McAloone, Timothy Charles

    This book is an adaptation of the author’s PhD thesis, in which he explored environmentally conscious design in the electrical/electronics industry sector. In this new and rapidly evolving field, existing research has not yet sought to understand the causes of success and the problems experienced...

  5. PV Power-Generation System with a Phase-Shift PWM Technique for High Step-Up Voltage Applications

    Directory of Open Access Journals (Sweden)

    Cheng-Tao Tsai

    2012-01-01

    Full Text Available A PV power-generation system with a phase-shift pulse-width modulation (PWM technique for high step-up voltage applications is proposed. The proposed power-generation system consists of two stages. In the input stage, all power switches of the full-bridge converter with phase-shift technique can be operated with zero-current switching (ZCS at turn-on or turn-off transition. Hence, the switching losses of the power switches can be reduced. Then, in the DC output stage, a voltage-doubler circuit is used to boost a high dc-link bus voltage. To supply a utility power, a dc/ac inverter is connected to induce a sinusoidal source. In order to draw a maximum power from PV arrays source, a microcontroller is incorporated with the perturbation and observation method to implement maximum power point tracking (MPPT algorithm and power regulating scheme. In this study, a full load power of 300 W prototype has been built. Experimental results are presented to verify the performance and feasibility of the proposed PV power-generation system.

  6. A pulsed-power generator merging inductive voltage and current adders and its switch trigger application example.

    Science.gov (United States)

    Li, Lee; Yafeng, Ge; Heqin, Zhong; Bin, Yu; Longjun, Xie

    2013-07-01

    A pulsed-power generator using inductive adder technology is proposed for the case of a discharge gap. The merit of this generator is to merge the pulsed-voltage and pulsed-current adders via the dual secondary windings with special circuit. For the nonlinear impedance in any discharge gap, the standalone voltage-pulse and current-pulse can be outputted successively by this generator. The proposed generator is especially useful for the common resolution of implementing pulse discharge at less cost. As an application example, a compact trigger prototype was developed to compatibly use in the gas-insulated and vacuum switches. Experiments achieved good results that the triggered switches showed stable performance and long life. If the basic circuit of this proposed generator is regarded as a pulsed-generating unit, a certain number of such units connected in parallel can be expected to form a general device with generating greater breakdown-voltage and sustained-current pulses for discharge gaps.

  7. Characteristics of Overvoltage Protection with Cascade Application of Surge Protective Devices in Low-Voltage AC Power Circuits

    Directory of Open Access Journals (Sweden)

    RADULOVIC, V.

    2015-08-01

    Full Text Available Surge Protective Devices (SPDs are widely used for protection of the equipment in low-voltage AC power circuits against wide variety of surges. Cascade application of SPDs starting at the service entrance of a building and downstream toward near sensitive equipment is intended to ensure optimal energy distribution among installed SPDs, as well as proper equipment protection against surges. Characteristics of overvoltage protection with two-stage application of SPDs have been analyzed in the paper through performed measurements, followed by simulations and numerical modeling using the ATP/EMTP and MATLAB Simulink. Parametric analysis of the protection's characteristics in wide range of influencing factors has been performed in order to define a set of applicable solutions for proper selection and performance of SPDs.

  8. Environmental Applications of Biosurfactants: Recent Advances

    OpenAIRE

    Swaranjit Singh Cameotra; Zofia Piotrowska-Seget; Magdalena Pacwa-Płociniczak; Grażyna A. Płaza

    2011-01-01

    Increasing public awareness of environmental pollution influences the search and development of technologies that help in clean up of organic and inorganic contaminants such as hydrocarbons and metals. An alternative and eco-friendly method of remediation technology of environments contaminated with these pollutants is the use of biosurfactants and biosurfactant-producing microorganisms. The diversity of biosurfactants makes them an attractive group of compounds for potential use in a wide va...

  9. Environmental monitoring: civilian applications of remote sensing

    Energy Technology Data Exchange (ETDEWEB)

    Bolton, W.; Lapp, M.; Vitko, J. Jr. [Sandia National Labs., Livermore, CA (United States); Phipps, G. [Sandia National Labs., Albuquerque, NM (United States)

    1996-11-01

    This report documents the results of a Laboratory Directed Research and Development (LDRD) program to explore how best to utilize Sandia`s defense-related sensing expertise to meet the Department of Energy`s (DOE) ever-growing needs for environmental monitoring. In particular, we focused on two pressing DOE environmental needs: (1) reducing the uncertainties in global warming predictions, and (2) characterizing atmospheric effluents from a variety of sources. During the course of the study we formulated a concept for using unmanned aerospace vehicles (UAVs) for making key 0798 climate measurements; designed a highly accurate, compact, cloud radiometer to be flown on those UAVs; and established the feasibility of differential absorption Lidar (DIAL) to measure atmospheric effluents from waste sites, manufacturing processes, and potential treaty violations. These concepts have had major impact since first being formulated in this ,study. The DOE has adopted, and DoD`s Strategic Environmental Research Program has funded, much of the UAV work. And the ultraviolet DIAL techniques have already fed into a major DOE non- proliferation program.

  10. APPLICATIONS OF ELECTROCHEMICAL IMMUNOSENSORS TO ENVIRONMENTAL MONITORING

    Science.gov (United States)

    This paper discusses basic electrochemical immunoassay technology. Factors limiting the practical application of antibodies to anlaytical problems are also presented. It addresses the potential use of immunoassay methods based on electrochemical detection for the analysis of env...

  11. DC buffering and floating current for a high voltage IMB application

    Energy Technology Data Exchange (ETDEWEB)

    Morrison, J. L. [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2014-08-01

    An interface technique for the latest generation of the Impedance Measurement Box (IMB) has been conceived to enable measurement of impedance spectra for battery modules up to 300V. A 300V capable or higher IMB is an enabling technology for in-situ diagnostics within electric vehicle charging stations or battery back-ups within power distribution sub-stations. It is possible that the existing IMB can be adapted via a 300V interface module to a test battery with voltage significantly greater than 50V. Recently a new concept was conceived for the calibration, algorithm and electronics of the IMB. That algorithm and calibration for that concept have been physically validated. The principal feature of the new electronics is the floating current source excitation of the battery under test. The single ended current excitation of the battery under test, used in the 50V IMB, requires that the negative terminal of the test battery must be the analog ground for the IMB. The new floating current technique allows the test battery to be fully high impedance isolated for a measurement. That isolation will improve IMB noise immunity and enable interrogation of cells internal to a battery module. All these techniques still use the same rapid concept for impedance measurement with the IMB. The purpose of this disclosure is to provide an overview of the analytical validation for three concepts to interface the floating current excitation to a high voltage battery. Recursive simulation models were used in different test scenarios to validate the various new concepts. The analysis will show that it is possible to interface the floating signal current to obtain an impedance measurement on a high voltage test battery. Additionally, the analysis will investigate stress seen by electronics while testing a 300V battery.

  12. Long Lifetime DC-Link Voltage Stabilization Module for Smart Grid Application

    DEFF Research Database (Denmark)

    Wang, Huai; Chung, Henry; Liu, Wenchao

    2012-01-01

    Power converters enable efficient and flexible control and conversion of electric energy among different smart grid players (i.e. producers, energy storage systems, and loads). One of the expected features of smart grid is that it will be more reliable compared to conventional grid. However, power...... converters are one kind of the lifetime limiting components applied in smart grid. One of the major causes is the malfunction of electrolytic capacitors (E-Caps) which are widely used for stabilizing the dc-link voltage in various types of power converters applied in smart grid. A dc-link module is therefore...

  13. High voltage series resonant inverter ion engine screen supply. [SCR series resonant inverter for space applications

    Science.gov (United States)

    Biess, J. J.; Inouye, L. Y.; Shank, J. H.

    1974-01-01

    A high-voltage, high-power LC series resonant inverter using SCRs has been developed for an Ion Engine Power Processor. The inverter operates within 200-400Vdc with a maximum output power of 2.5kW. The inverter control logic, the screen supply electrical and mechanical characteristics, the efficiency and losses in power components, regulation on the dual feedback principle, the SCR waveforms and the component weight are analyzed. Efficiency of 90.5% and weight density of 4.1kg/kW are obtained.

  14. Environmental properties of metallic minerals and their applications in environmental protection in China

    Institute of Scientific and Technical Information of China (English)

    WANG Jizhong; LI Shengrong; JIANG Yonghong; WEI Ruihua; NIU Huapeng

    2005-01-01

    In terms of environmental mineralogy, the environmental properties of metallic minerals, including chemical activation, adsorption, pore effect and nanometer effect, have been analyzed. On the basis of the analysis of environmental properties of metallic minerals, the applications of iron-bearing sulfides, iron and manganese oxides in the purification of wastewaters containing heavy metal ions (Cr 6+, Hg 2+, Pb 2+, etc.) have been summarized. Moreover, research on the application of metallic minerals in environmental protection has been anticipated. It should be a piece of dominating work for environmental mineralogic researchers in the future to lucubrate systematically the physical and chemical characteristics of the metallic mineral surfaces, further reveal the reciprocity process between metallic minerals and water surface, perfect the theory and model of the metallic minerals to remove contaminants, intensify study on the facilities and techniques of metallic minerals to remove contaminants, and entail well the extension and propagation of achievements.

  15. Loading Analysis of Modular Multi-level Converter for Offshore High-voltage DC Application under Various Grid Faults

    DEFF Research Database (Denmark)

    Liu, Hui; Ma, Ke; Loh, Poh Chiang;

    2016-01-01

    The modular multi-level converter has become an interesting candidate in high-voltage DC systems due to its higher voltage levels and modular construction. Low-voltage ride-through is an important grid requirement for modular multi-level converter–high-voltage DC since not only causes control cha...... be of importance for the design of the cooling system....

  16. Application of Hybrid MOPSO Algorithm to Optimal Reactive Power Dispatch Problem Considering Voltage Stability

    Directory of Open Access Journals (Sweden)

    Yujiao Zeng

    2014-01-01

    Full Text Available This study presents a novel hybrid multiobjective particle swarm optimization (HMOPSO algorithm to solve the optimal reactive power dispatch (ORPD problem. This problem is formulated as a challenging nonlinear constrained multiobjective optimization problem considering three objectives, that is, power losses minimization, voltage profile improvement, and voltage stability enhancement simultaneously. In order to attain better convergence and diversity, this work presents the use of combing the classical MOPSO with Gaussian probability distribution, chaotic sequences, dynamic crowding distance, and self-adaptive mutation operator. Moreover, multiple effective strategies, such as mixed-variable handling approach, constraint handling technique, and stopping criteria, are employed. The effectiveness of the proposed algorithm for solving the ORPD problem is validated on the standard IEEE 30-bus and IEEE 118-bus systems under nominal and contingency states. The obtained results are compared with classical MOPSO, nondominated sorting genetic algorithm (NSGA-II, multiobjective evolutionary algorithm based on decomposition (MOEA/D, and other methods recently reported in the literature from the point of view of Pareto fronts, extreme, solutions and multiobjective performance metrics. The numerical results demonstrate the superiority of the proposed HMOPSO in solving the ORPD problem while strictly satisfying all the constraints.

  17. An Ultra-Low Voltage Analog Front End for Strain Gauge Sensory System Application in 0.18µm CMOS

    Science.gov (United States)

    Edward, Alexander; Chan, Pak Kwong

    This paper presents analysis and design of a new ultra-low voltage analog front end (AFE) dedicated to strain sensor applications. The AFE, designed in 0.18µm CMOS process, features a chopper-stabilized instrumentation amplifier (IA), a balanced active MOSFET-C 2nd order low pass filter (LPF), a clock generator and a voltage booster which operate at supply voltage (Vdd) of 0.6V. The designed IA achieves 30dB of closed-loop gain, 101dB of common-mode rejection ratio (CMRR) at 50Hz, 80dB of power-supply rejection ratio (PSRR) at 50Hz, thermal noise floor of 53.4 nV/√Hz, current consumption of 14µA, and noise efficiency factor (NEF) of 9.7. The high CMRR and rail-to-rail output swing capability is attributed to a new low voltage realization of the active-bootstrapped technique using a pseudo-differential gain-boosting operational transconductance amplifier (OTA) and proposed current-driven bulk (CDB) biasing technique. An output capacitor-less low-dropout regulator (LDO), with a new fast start-up LPF technique, is used to regulate this 0.6V supply from a 0.8-1.0V energy harvesting power source. It achieves power supply rejection (PSR) of 42dB at frequency of 1MHz. A cascode compensated pseudo differential amplifier is used as the filter's building block for low power design. The filter's single-ended-to-balanced converter is implemented using a new low voltage amplifier with two-stage common-mode cancellation. The overall AFE was simulated to have 65.6dB of signal-to-noise ratio (SNR), total harmonic distortion (THD) of less than 0.9% for a 100Hz sinusoidal maximum input signal, bandwidth of 2kHz, and power consumption of 51.2µW. Spectre RF simulations were performed to validate the design using BSIM3V3 transistor models provided by GLOBALFOUNDRIES 0.18µm CMOS process.

  18. Geomaterials: their application to environmental remediation

    Directory of Open Access Journals (Sweden)

    Hirohisa Yamada, Kenji Tamura, Yujiro Watanabe, Nobuo Iyi and Kazuya Morimoto

    2011-01-01

    Full Text Available Geomaterials are materials inspired by geological systems originating from the billion years long history of the Earth. This article reviews three important classes of geomaterials. The first one is smectites—layered silicates with a cation-exchange capacity. Smectites are useful for removing pollutants and as intercalation compounds, catalysts and polymer nanocomposites. The second class is layered double hydroxides (LDHs. They have an anion-exchange capacity and are used as catalysts, catalyst precursors, sorbents and scavengers for halogens. The third class of geomaterials is zeolites—microporous materials with a cation-exchange capacity which are used for removing harmful cations. Zeolite composites with LDHs can absorb ammonium and phosphate ions in rivers and lakes, whereas zeolite/apatite composites can immobilize the radioactive iodine. These geomaterials are essential for environmental remediation.

  19. 4Nx Non-Isolated and Non-Inverting Hybrid Interleaved Multilevel Boost Converter Based on VLCIm Cell and Cockroft Walton Voltage Multiplier for Renewable Energy Applications

    DEFF Research Database (Denmark)

    Bhaskar, Mahajan Sagar; Padmanaban, Sanjeevikumar; Blaabjerg, Frede

    2016-01-01

    In this treatise, 4Nx hybrid Non Inverting & Non Isolated (NI-NI) DC-DC interleaved multi-level boost converter (4Nx IMBC) for renewable energy applications is proposed. The proposed 4Nx IMBC is derived by coalescing the feature of 2Nx DC-DC Interleaved Multi-level Boost Converter (2Nx IMBC......), voltage-lift-switched-inductor-modified (VLSlm Cell) and Cockcroft Walton (CW) voltage multipliers. The 4Nx converter provides 4N times more conversion voltage ratio compared to conventional boost converter where N denotes the number of output stages of the 4Nx IMBC. To make renewable energy sources...

  20. Discrete-Time Domain Modelling of Voltage Source Inverters in Standalone Applications: Enhancement of Regulators Performance by Means of Smith Predictor

    DEFF Research Database (Denmark)

    Federico, de Bosio; de Sousa Ribeiro, Luiz Antonio; Freijedo Fernandez, Francisco Daniel

    2017-01-01

    and Smith predictor design, respectively, are obtained. Subsequently, the voltage regulator is also designed for a wide bandwidth, which permits the inclusion of resonant filters for the steady-state mitigation of odd harmonics at nonlinear unbalance load terminals. Discrete-time domain implementation......The decoupling of the capacitor voltage and inductor current has been shown to improve significantly the dynamic performance of voltage source inverters in standalone applications. However, the computation and PWM delays still limit the achievable bandwidth. In this paper a discrete-time domain...

  1. Differential voltage analyses of high-power, lithium-ion cells. 1. Technique and application

    Science.gov (United States)

    Bloom, Ira; Jansen, Andrew N.; Abraham, Daniel P.; Knuth, Jamie; Jones, Scott A.; Battaglia, Vincent S.; Henriksen, Gary L.

    The C/25 discharge data from 18650-size cells containing LiNi 0.8Co 0.1Al 0.1O 2 cathode and graphite anode laminates were analyzed through the use of the differential voltage, d V/d Q, curves. Using half-cell data, the peaks in the d V/d Q curve of the full cell data were assigned. Analysis of the relative peak shifts allowed for the determination of the source of capacity fade. For cells formed and aged at 45 °C for 40 weeks (capacity fade = 7.5%), the analysis indicated negligible loss of accessible material at the anode and at the cathode. Capacity loss of the cell could be accounted for, largely, by side reactions at the anode. This type of analysis can be used when the introduction of a reference electrode is difficult or impractical.

  2. Investigation of Transformer Winding Architectures for High Voltage Capacitor Charging Applications

    DEFF Research Database (Denmark)

    Schneider, Henrik; Thummala, Prasanth; Huang, Lina

    2014-01-01

    Transformer parameters such as leakage inductance and self-capacitance are rarely calculated in advance during the design phase, because of the complexity and huge analytical error margins caused by practical winding implementation issues. Thus, choosing one transformer architecture over another...... for a given design is usually based on experience or a trial and error approach. This work presents equations regarding calculation of leakage inductance, self-capacitance and AC resistance in transformer winding architectures, ranging from the common non-interleaved primary/secondary winding architecture......, to an interleaved, sectionalized and bank winded architecture. The analytical results are evaluated experimentally and through FEM simulations. Different transformer winding architectures are investigated in terms of the losses caused by the transformer parasitics for a bidirectional high-voltage (~1500 V) flyback...

  3. 0.18μm CMOS Low Voltage Power Amplifier For WSN Application

    Directory of Open Access Journals (Sweden)

    Wu Chenjian

    2013-08-01

    Full Text Available This paper presents the design of a Class A/B power amplifier (PA for 2.4-2.4835GHz Wireless Sensor Network (WSN system in 0.18μm CMOS technology. The PA adopts the single-stage differential structure and the output power of the PA can be controlled by switching the sizes of transistors. Seven different level of output power can be obtained through a three- bit control code. The tested results shows that the proposed PA achieves power added efficiency (PAE of 26.73% while delivering an output power of 6.35dBm at 1dB compression point. Its power gain is 15.87dB. With a low DC voltage supply of 1V, its power consumption is 15.3mW. The PA die size is 1070×610μm2.

  4. Quantum Mechanical Analysis of GaN Nanowire Transistor for High Voltage Applications

    Directory of Open Access Journals (Sweden)

    Neel Chatterjee

    2016-12-01

    Full Text Available The paper presents the quantum mechanical analysis of Gallium Nitride nanowire transistor. The effect of high k gate dielectric and different gate metals on the electrical characteristics of the device is studied. Nanowire width has been reduced to have a proper control on the device characteristics at reduced gate length. A high value of drain current is obtained at gate length of 10 nm and nanowire radius equal to 10 nm, is obtained. Also high voltage operation of the device upto 40 volts has been shown. A flatter transconductance curve is obtained which shows the linearity of the device. The results obtained are comparable with the experimental and simulated data reported in literature

  5. Low Voltage, High-Q SOI MEMS Varactors for RF Applications

    DEFF Research Database (Denmark)

    Yalcinkaya, Arda Deniz; Jensen, Søren; Hansen, Ole

    2003-01-01

    -aspect ratio (>20) parallel comb-drive structures with vertical sidewalls. Consisting of only one lithographic mask step, the process sequence can be completed in a short time. Having 1 pF of nominal capacitance, the device offers an electrical quality factor of 100 at 100MHz and a self resonance at 4.08 GHz......, enabling the usage as a passive component in the RF band. The mechanical settling time of the varactor is measured to be 200 μs in ambient air. For control voltages ranging from 1.5V to 5V, tuning ratios of 2:1, 1.7:1 and 1.5:1 are obtained from different capacitor designs. It was found that the device...

  6. Controlled Vocabulary Service Application for Environmental Data Store

    Science.gov (United States)

    Ji, P.; Piasecki, M.; Lovell, R.

    2013-12-01

    In this paper we present a controlled vocabulary service application for Environmental Data Store (EDS). The purpose for such application is to help researchers and investigators to archive, manage, share, search, and retrieve data efficiently in EDS. The Simple Knowledge Organization System (SKOS) is used in the application for the representation of the controlled vocabularies coming from EDS. The controlled vocabularies of EDS are created by collecting, comparing, choosing and merging controlled vocabularies, taxonomies and ontologies widely used and recognized in geoscience/environmental informatics community, such as Environment ontology (EnvO), Semantic Web for Earth and Environmental Terminology (SWEET) ontology, CUAHSI Hydrologic Ontology and ODM Controlled Vocabulary, National Environmental Methods Index (NEMI), National Water Information System (NWIS) codes, EPSG Geodetic Parameter Data Set, WQX domain value etc. TemaTres, an open-source, web -based thesaurus management package is employed and extended to create and manage controlled vocabularies of EDS in the application. TemaTresView and VisualVocabulary that work well with TemaTres, are also integrated in the application to provide tree view and graphical view of the structure of vocabularies. The Open Source Edition of Virtuoso Universal Server is set up to provide a Web interface to make SPARQL queries against controlled vocabularies hosted on the Environmental Data Store. The replicas of some of the key vocabularies commonly used in the community, are also maintained as part of the application, such as General Multilingual Environmental Thesaurus (GEMET), NetCDF Climate and Forecast (CF) Standard Names, etc.. The application has now been deployed as an elementary and experimental prototype that provides management, search and download controlled vocabularies of EDS under SKOS framework.

  7. Laser induced fluorescence technique for environmental applications

    Science.gov (United States)

    Utkin, Andrei B.; Felizardo, Rui; Gameiro, Carla; Matos, Ana R.; Cartaxana, Paulo

    2014-08-01

    We discuss the development of laser induced fluorescence sensors and their application in the evaluation of water pollution and physiological status of higher plants and algae. The sensors were built on the basis of reliable and robust solid-state Nd:YAG lasers. They demonstrated good efficiency in: i) detecting and characterizing oil spills and dissolved organic matter; ii) evaluating the impact of stress on higher plants (cork oak, maritime pine, and genetically modified Arabidopsis); iii) tracking biomass changes in intertidal microphytobenthos; and iv) mapping macroalgal communities in the Tagus Estuary.

  8. Fabrication and Characterization of III-V Tunnel Field-Effect Transistors for Low Voltage Logic Applications

    Science.gov (United States)

    Romanczyk, Brian R.

    With voltage scaling to reduce power consumption in scaled transistors the subthreshold swing is becoming a critical factor influencing the minimum voltage margin between the transistor on and off-states. Conventional metal-oxide-semiconductor field-effect transistors (MOSFETs) are fundamentally limited to a 60 mV/dec swing due to the thermionic emission current transport mechanism at room temperature. Tunnel field-effect transistors (TFETs) utilize band-to-band tunneling as the current transport mechanism resulting in the potential for sub-60 mV/dec subthreshold swings and have been identified as a possible replacement to the MOSFET for low-voltage logic applications. The TFET operates as a gated p-i-n diode under reverse bias where the gate electrode is placed over the intrinsic channel allowing for modulation of the tunnel barrier thickness. When the barrier is sufficiently thin the tunneling probability increases enough to allow for significant number of electrons to tunnel from the source into the channel. To date, experimental TFET reports using III-V semiconductors have failed to produce devices that combine a steep subthreshold swing with a large enough drive current to compete with scaled CMOS. This study developed the foundations for TFET fabrication by improving an established Esaki tunnel diode process flow and extending it to include the addition of a gate electrode to form a TFET. The gating process was developed using an In0.53Ga 0.57As TFET which demonstrated a minimum subthreshold slope of 100 mV/dec. To address the issue of TFET drive current an InAs/GaSb heterojunction TFET structure was investigated taking advantage of the smaller tunnel barrier height.

  9. LOCAL WEATHER CLASSIFICATIONS FOR ENVIRONMENTAL APPLICATIONS

    Directory of Open Access Journals (Sweden)

    Katarzyna PIOTROWICZ

    2013-03-01

    Full Text Available Two approaches of local weather type definitions are presented and illustrated for selected stations of Poland and Hungary. The subjective classification, continuing long traditions, especially in Poland, relies on diurnal values of local weather elements. The main types are defined according to temperature with some sub-types considering relative sunshine duration, diurnal precipitation totals, relative humidity and wind speed. The classification does not make a difference between the seasons of the year, but the occurrence of the classes obviously reflects the annual cycle. Another important feature of this classification is that only a minor part of the theoretically possible combination of the various types and sub-types occurs in all stations of both countries. The objective version of the classification starts from ten possible weather element which are reduced to four according to factor analysis, based on strong correlation between the elements. This analysis yields 3 to 4 factors depending on the specific criteria of selection. The further cluster analysis uses four selected weather elements belonging to different rotated factors. They are the diurnal mean values of temperature, of relative humidity, of cloudiness and of wind speed. From the possible ways of hierarchical cluster analysis (i.e. no a priori assumption on the number of classes, the method of furthest neighbours is selected, indicating the arguments of this decision in the paper. These local weather types are important tools in understanding the role of weather in various environmental indicators, in climatic generalisation of short samples by stratified sampling and in interpretation of the climate change.

  10. Characterization of heterologously expressed transporter genes by patch- and voltage-clamp methods: Application to cyclic nucleotide-dependent responses

    KAUST Repository

    Lemtiri-Chlieh, Fouad

    2013-09-03

    The application of patch- and voltage-clamp methods to study ion transport can be limited by many hurdles: the size of the cells to be patched and/or stabbed, the subcellular localization of the molecule of interest, and its density of expression that could be too low even in their own native environment. Functional expression of genes using recombinant DNA technology not only overcomes those hurdles but also affords additional and elegant investigations such as single-point mutation studies and subunit associations/regulations. In this chapter, we give a step-by-step description of two electrophysiological methods, patch clamp and two-electrode voltage clamp (TEVC), that are routinely used in combination with heterologous gene expression to assist researchers interested in the identification and characterization of ion transporters. We describe how to (1) obtain and maintain the cells suitable for the use with each of the above-mentioned methods (i.e., HEK-293 cells and yeast spheroplasts to use with the patch-clamp methodology and Xenopus laevis oocytes with TEVC), (2) transfect/inject them with the gene of interest, and (3) record ion transport activities. © Springer Science+Business Media New York 2013.

  11. Fabrication of Ultra-Thin Printed Organic TFT CMOS Logic Circuits Optimized for Low-Voltage Wearable Sensor Applications.

    Science.gov (United States)

    Takeda, Yasunori; Hayasaka, Kazuma; Shiwaku, Rei; Yokosawa, Koji; Shiba, Takeo; Mamada, Masashi; Kumaki, Daisuke; Fukuda, Kenjiro; Tokito, Shizuo

    2016-05-09

    Ultrathin electronic circuits that can be manufactured by using conventional printing technologies are key elements necessary to realize wearable health sensors and next-generation flexible electronic devices. Due to their low level of power consumption, complementary (CMOS) circuits using both types of semiconductors can be easily employed in wireless devices. Here, we describe ultrathin CMOS logic circuits, for which not only the source/drain electrodes but also the semiconductor layers were printed. Both p-type and n-type organic thin film transistor devices were employed in a D-flip flop circuit in the newly developed stacked structure and exhibited excellent electrical characteristics, including good carrier mobilities of 0.34 and 0.21 cm(2) V(-1) sec(-1), and threshold voltages of nearly 0 V with low operating voltages. These printed organic CMOS D-flip flop circuits exhibit operating frequencies of 75 Hz and demonstrate great potential for flexible and printed electronics technology, particularly for wearable sensor applications with wireless connectivity.

  12. Fabrication of Ultra-Thin Printed Organic TFT CMOS Logic Circuits Optimized for Low-Voltage Wearable Sensor Applications

    Science.gov (United States)

    Takeda, Yasunori; Hayasaka, Kazuma; Shiwaku, Rei; Yokosawa, Koji; Shiba, Takeo; Mamada, Masashi; Kumaki, Daisuke; Fukuda, Kenjiro; Tokito, Shizuo

    2016-05-01

    Ultrathin electronic circuits that can be manufactured by using conventional printing technologies are key elements necessary to realize wearable health sensors and next-generation flexible electronic devices. Due to their low level of power consumption, complementary (CMOS) circuits using both types of semiconductors can be easily employed in wireless devices. Here, we describe ultrathin CMOS logic circuits, for which not only the source/drain electrodes but also the semiconductor layers were printed. Both p-type and n-type organic thin film transistor devices were employed in a D-flip flop circuit in the newly developed stacked structure and exhibited excellent electrical characteristics, including good carrier mobilities of 0.34 and 0.21 cm2 V‑1 sec‑1, and threshold voltages of nearly 0 V with low operating voltages. These printed organic CMOS D-flip flop circuits exhibit operating frequencies of 75 Hz and demonstrate great potential for flexible and printed electronics technology, particularly for wearable sensor applications with wireless connectivity.

  13. NEOCHIM: An electrochemical method for environmental application

    Science.gov (United States)

    Leinz, R.W.; Hoover, D.B.; Meier, A.L.

    1999-01-01

    Ion migration and electroosmosis are the principal processes underlying electrokinetic remediation of hazardous wastes from soils. These processes are a response of charged species to an applied electrical current and they are accompanied by electrolysis of water at the electrodes through which the current is applied. Electrolysis results in the formation of OH- at the cathode and H+ at the anode. The current drives the OH- and H+ thus formed from the electrodes, through the soil and to the electrode of opposite charge. Introduction of OH- and H+ into the soil being treated modifies soil chemistry and can interfere with either the collection or immobilization of hazardous waste ions. The introduction of either OH- or H+ to the soil can be problematic to electrokinetic remediation but the problem caused by OH- has been the focus of most researchers. The problem has been addressed by flushing the OH- from the soil near the cathode or treating the soil with buffers. These treatments would apply as well to soils affected by H+. With the NEOCHIM technology, developed by the U.S. Geological Survey (USGS) for use as a sampling technique in exploration for buried ore deposits, OH- and H+ are retained in the inner compartment of two-compartment electrodes and are thus prevented from reaching the soil. This enables the extraction of cations and anions, including anionic forms of toxic metals such as HAsO42-. One of the principal attributes of NEOCHIM is the large volume of soil from which ions can be extracted. It is mathematically demonstrable that NEOCHIM extraction volumes can be orders of magnitude greater than volumes typically sampled in more conventional geochemical exploration methods or for environmental sampling. The technology may also be used to introduce selected ions into the soil that affect the solubility of ceratin ions present in the soil. Although field tests for mineral exploration have shown NEOCHIM extraction efficiencies of about 25-35%, laboratory

  14. Application of Optical Diagnosis to Aged Low-Voltage Cable Insulation in Nuclear Plants

    Science.gov (United States)

    Katagiri, Junichi; Takezawa, Yoshitaka; Shouji, Hiroshi

    We have developed a novel non-destructive optical diagnosis technique for low-voltage cable insulations used in nuclear power plants. The key features of this diagnosis are the use of two wavelengths to measure the change in reflective absorbance (ΔAR), the use of polarized light to measure crystallinity and the use of element volatilizing to measure fluorescence. Chemical kinetics is used to predict the lifetimes of the cable insulations. When cable insulations darken and harden by time degradation, the ΔAR and depolarization parameters increase. This means that the cross-linking density in the cable insulations increases due to deterioration reactions. When the cross-linking density of insulation increases, its elasticity, corresponding to the material's life, increases. Similarly, as the crystallinity increases due to the change in the high-order structure of the insulating resin caused by irradiation, its elongation property decreases. The elongation property of insulation is one of the most important parameters that can be used to evaluate material lifetimes, because it relates to elasticity. The ΔAR correlated with the elongation property, and the correlation coefficient of an accelerated experiment using model pieces was over 0.9. Thus, we concluded that this optical diagnosis should be applied to evaluate the degradation of cable insulations used in nuclear power plants.

  15. Cold wire constant voltage anemometry to measure temperature fluctuations and its application in a thermoacoustic system

    Science.gov (United States)

    Cleve, Sarah; Jondeau, Emmanuel; Blanc-Benon, Philippe; Comte-Bellot, Geneviève

    2017-04-01

    The knowledge of temperature fluctuations is essential for most thermoacoustic systems. In the present paper, cold wire constant-voltage anemometry (CVA) to measure temperature fluctuations is presented. Corrections for the thermal inertia and for the end losses of the wire are applied during the post-processing. The correction for the thermal inertia of the cold wire is achieved by applying a time dependent thermal lag as proposed originally for a constant-current anemometry (CCA) system. This thermal lag is measured in parallel by a hot wire. The thermal end losses of the wires to their supports are also considered and approximate corrections are proposed. The procedure for the cold wire CVA is validated in the acoustic field of an acoustic resonator with wires of different lengths. A comparison between a CVA and a CCA measurement also confirms the CVA measurement. Furthermore, the proposed measurement procedure is applied close to the stack of a thermoacoustic refrigerator. Supposing a two-dimensional flow, the simultaneous measurement of velocity and temperature fluctuations is possible. This allows a detailed examination of the acoustic field close to the stack, including the study of the correlation between temperature and velocity.

  16. High Voltage Smart Power Module For Fault-Tolerant Launcher Applications

    Directory of Open Access Journals (Sweden)

    Richard Debrouwere

    2017-01-01

    This paper presents the design of a low cost and highly integrated smart power module (SPM intended to be used into launchers applications, embedding technologies and components from automotive world and being mainly producible by large-scale industry.

  17. Characterization of clay-modified thermoset polymers under various environmental conditions for the use in high-voltage power pylons

    DEFF Research Database (Denmark)

    Kliem, Mathias; Høgsberg, Jan Becker; Wang, Qian

    2017-01-01

    , the morphology was found to be of exfoliated structure mainly. Static, uniaxial tensile tests showed that the addition of nanoclay to thermoset polymers led to a beneficial effect on the stiffness, whereas the tensile strength and ductility significantly decreased. When exposed to different environmental...

  18. Supercritical fluid technology for energy and environmental applications

    CERN Document Server

    Anikeev, Vladimir

    2014-01-01

    Supercritical Fluid Technology for Energy and Environmental Applications covers the fundamental principles involved in the preparation and characterization of supercritical fluids (SCFs) used in the energy production and other environmental applications. Energy production from diversified resources - including renewable materials - using clean processes can be accomplished using technologies like SCFs. This book is focused on critical issues scientists and engineers face in applying SCFs to energy production and environmental protection, the innovative solutions they have found, and the challenges they need to overcome. The book also covers the basics of sub- and supercritical fluids, like the thermodynamics of phase and chemical equilibria, mathematical modeling, and process calculations. A supercritical fluid is any substance at a temperature and pressure above its critical point where distinct liquid and gas phases do not exist. At this state the compound demonstrates unique properties, which can be "fine...

  19. Environmental considerations for application of high Tc superconductors in space

    Science.gov (United States)

    Carlberg, I. A.; Kelliher, W. C.; Wise, S. A.; Hooker, M. W.; Buckley, J. D.

    1993-01-01

    The impact of the environmental factors on the performance of the superconductive devices during spaceflight missions is reviewed. Specific factors typical of spaceflight are addressed to evaluate superconductive devices for space-based applications including preflight storage, radiation, vibration, and thermal cycling.

  20. A REVIEW OF ENVIRONMENTAL APPLICATIONS OF BIOLUMINESCENCE MEASUREMENTS

    Science.gov (United States)

    This review of the recent literature on environmental applications of bioluminescence systems will focus on in vivo and in vitro bioluminescence methods that have been utilized to elucidate properties of chemicals, toxic and mutagenic effects, and to estimate biomass. The unifyin...

  1. Nuclear magnetic resonance in environmental engineering: principles and applications.

    NARCIS (Netherlands)

    Lens, P.N.L.; Hemminga, M.A.

    1998-01-01

    This paper gives an introduction to nuclear magnetic resonance spectroscopy (NMR) and magnetic resonance imaging (MRI) in relation to applications in the field of environmental science and engineering. The underlying principles of high resolution solution and solid state NMR, relaxation time measure

  2. DEAP actuator and its high voltage driver for heating valve application

    DEFF Research Database (Denmark)

    Huang, Lina; Nørmølle, L. F.; Sarban, R.;

    2014-01-01

    Due to the advantages of DEAP (Dielectric Electro Active Polymer) material, such as light weight, noise free operation, high energy and power density and fast response speed, it can be applied in a variety of applications to replace the conventional transducers or actuators. This paper introduces...... DEAP actuator to the heating valve system and conducts a case study to discuss the feasible solution in designing DEAP actuator and its driver for heating valve application. First of all, the heating valves under study are briefly introduced. Then the design and the development for DEAP actuator...

  3. Assessment of the risk of failure of high voltage substations due to environmental conditions and pollution on insulators.

    Science.gov (United States)

    Castillo Sierra, Rafael; Oviedo-Trespalacios, Oscar; Candelo, John E; Soto, Jose D

    2015-07-01

    Pollution on electrical insulators is one of the greatest causes of failure of substations subjected to high levels of salinity and environmental pollution. Considering leakage current as the main indicator of pollution on insulators, this paper focuses on establishing the effect of the environmental conditions on the risk of failure due to pollution on insulators and determining the significant change in the magnitude of the pollution on the insulators during dry and humid periods. Hierarchical segmentation analysis was used to establish the effect of environmental conditions on the risk of failure due to pollution on insulators. The Kruskal-Wallis test was utilized to determine the significant changes in the magnitude of the pollution due to climate periods. An important result was the discovery that leakage current was more common on insulators during dry periods than humid ones. There was also a higher risk of failure due to pollution during dry periods. During the humid period, various temperatures and wind directions produced a small change in the risk of failure. As a technical result, operators of electrical substations can now identify the cause of an increase in risk of failure due to pollution in the area. The research provides a contribution towards the behaviour of the leakage current under conditions similar to those of the Colombian Caribbean coast and how they affect the risk of failure of the substation due to pollution.

  4. Electronics drivers for high voltage dielectric electro active polymer (DEAP) applications

    DEFF Research Database (Denmark)

    Zhang, Zhe; Andersen, Michael A. E.

    2015-01-01

    magnetic and piezoelectric transformers are employed for the heating valve and incremental motor application, where only ON/OFF regulation is adopted fo r energy saving; as for DEAP based energy harvesting, the no - isolated Buck/Boost converter is used, due to the system high power capacity (above 100W...

  5. Environmental proteomics: applications of proteome profiling in environmental microbiology and biotechnology.

    Science.gov (United States)

    Lacerda, Carla M R; Reardon, Kenneth F

    2009-01-01

    In this review, we present the use of proteomics to advance knowledge in the field of environmental biotechnology, including studies of bacterial physiology, metabolism and ecology. Bacteria are widely applied in environmental biotechnology for their ability to catalyze dehalogenation, methanogenesis, denitrification and sulfate reduction, among others. Their tolerance to radiation and toxic compounds is also of importance. Proteomics has an important role in helping uncover the pathways behind these cellular processes. Environmental samples are often highly complex, which makes proteome studies in this field especially challenging. Some of these challenges are the lack of genome sequences for the vast majority of environmental bacteria, difficulties in isolating bacteria and proteins from certain environments, and the presence of complex microbial communities. Despite these challenges, proteomics offers a unique dynamic view into cellular function. We present examples of environmental proteomics of model organisms, and then discuss metaproteomics (microbial community proteomics), which has the potential to provide insights into the function of a community without isolating organisms. Finally, the environmental proteomics literature is summarized as it pertains to the specific application areas of wastewater treatment, metabolic engineering, microbial ecology and environmental stress responses.

  6. Effect of polymer aggregation on the open circuit voltage in organic photovoltaic cells: aggregation-induced conjugated polymer gel and its application for preventing open circuit voltage drop.

    Science.gov (United States)

    Kim, Bong-Gi; Jeong, Eun Jeong; Park, Hui Joon; Bilby, David; Guo, L Jay; Kim, Jinsang

    2011-03-01

    To investigate the structure-dependent aggregation behavior of conjugated polymers and the effect of aggregation on the device performance of conjugated polymer photovoltaic cells, new conjugated polymers (PVTT and CN-PVTT) having the same regioregularity but different intermolecular packing were prepared and characterized by means of UV-vis spectroscopy and atomic force microscopy (AFM). Photovoltaic devices were prepared with these polymers under different polymer-aggregate conditions. Polymer aggregation induced by thermal annealing increases the short circuit current but provides no advantage in the overall power conversion efficiency because of a decrease in the open circuit voltage. The device fabricated from a pre-aggregated polymer suspension, acquired from ultrasonic agitation of a conjugated polymer gel, showed enhanced performance because of better phase separation and reduced recombination between polymer/PCBM.

  7. An Overview of Low Voltage DC Distribution Systems for Residential Applications

    DEFF Research Database (Denmark)

    Diaz, Enrique Rodriguez; Firoozabadi, Mehdi Savaghebi; Quintero, Juan Carlos Vasquez;

    2015-01-01

    The concept of a microgrid has drawn the interest of research community in recent years. The most interesting aspects are the integration of renewable energy sources and energy storage systems at the consumption level, aiming to increase power quality, reliability and efficiency. On top of this...... applications. Several publications that study the potential energy savings and overall advantages of the LVDC distribution systems are analysed. Different power architectures and topologies are discussed. The existing demonstration facilities where LVDC distribution systems have been implemented are also shown......., the increasing of DC-based loads has re-open the discussion of DC vs AC distribution systems. As a consequence a lot of research has been done on DC distribution systems and its potential for residential applications. This paper presents an overview of the LVDC distribution systems used in residential...

  8. High voltage engineering fundamentals

    CERN Document Server

    Kuffel, E; Hammond, P

    1984-01-01

    Provides a comprehensive treatment of high voltage engineering fundamentals at the introductory and intermediate levels. It covers: techniques used for generation and measurement of high direct, alternating and surge voltages for general application in industrial testing and selected special examples found in basic research; analytical and numerical calculation of electrostatic fields in simple practical insulation system; basic ionisation and decay processes in gases and breakdown mechanisms of gaseous, liquid and solid dielectrics; partial discharges and modern discharge detectors; and over

  9. Low-Power, Low-Voltage Electroosmotic Actuator for an Implantable Micropumping System Intended for Drug Delivery Applications

    Science.gov (United States)

    Getpreecharsawas, Jirachai

    An electroosmotic (EO) actuator offers a low-power, low-voltage alternative in a diaphragm-based periodic displacement micropump intended for an implantable drug delivery system. The actuator utilizes an electroosmosis mechanism to transport liquid across a membrane to deflect the pumping diaphragms in a reciprocating manner. In the study, the membrane made of porous nanocrystalline silicon (pnc-Si) tens of nanometers in thickness was used as the promising EO generator with low power consumption and small package size. This ultrathin membrane provides the opportunity for electrode integration such that the very high electric field can be generated across the membrane with the applied potential under 1 volt for low flow rate applications like drug delivery. Due to such a low applied voltage, the challenge, however, imposes on the capability of generating the pumping pressure high enough to deflect the pumping diaphragms and overcome the back pressure normally encountered in the biological tissue and organ. This research identified the cause of weak pumping pressure that the electric field inside the orifice-like nanopores of the ultrathin membrane is weaker than conventional theory would predict. It no longer scales uniformly with the thickness of membrane, but with the pore length-to-diameter aspect ratio for each nanopore. To enhance the pumping performance, the pnc-Si membrane was coated with an ultrathin Nafion film. As a result, the induced concentration difference across the Nafion film generates the osmotic pressure against the back pressure allowing the EO actuator to maintain the target pumping flow rate under 1 volt.

  10. Environmental assessment of urban wastewater reuse: treatment alternatives and applications.

    Science.gov (United States)

    Meneses, Montse; Pasqualino, Jorgelina C; Castells, Francesc

    2010-09-01

    The main function of a Wastewater Treatment Plant is to minimize the environmental impact of discharging untreated water into natural water systems. Also a Wastewater Treatment Plant may get a resource from wastewater carrying out a tertiary treatment on the treated wastewater which can be reused in non-potable applications. Water reuse strategies are intended to address the problem of water scarcity without aggravating other environmental problems, thus reflecting the need of their environmental assessment. In this paper we used Life Cycle Assessment to evaluate different disinfection treatments (chlorination plus ultraviolet treatment, ozonation and ozonation plus hydrogen peroxide) and to assess the environmental advantages and drawbacks of urban wastewater reuse in non-potable applications. To do so, we compared the environmental impacts of producing 1m(3) of water for non-potable uses from reclaimed water, potable water and desalinated water sources. The calculation has used current operating data from a Wastewater Treatment Plant located in the Mediterranean area, although the results can be applied to any other plant with similar technology. The ozonation and ozonation plus hydrogen peroxide disinfection treatment technologies have similar environmental profiles. However most of the indicators are about 50% higher than the ultraviolet disinfection except for the acidification (100% higher) and photochemical oxidation (less than 5%). Non-potable uses (both agricultural and urban uses) of reclaimed water have environmental and economical advantages. Reuse of treated wastewater is particularly beneficial when it can replace desalinated water. Consequently, reclaimed water should be promoted for non-potable uses, when there is scarcity of freshwater.

  11. Control strategy and hardware implementation for DC–DC boost power circuit based on proportional–integral compensator for high voltage application

    Directory of Open Access Journals (Sweden)

    Sanjeevikumar Padmanaban

    2015-06-01

    Full Text Available For high-voltage (HV applications, the designers mostly prefer the classical DC–DC boost converter. However, it lacks due to the limitation of the output voltage by the gain transfer ratio, decreased efficiency and its requirement of two sensors for feedback signals, which creates complex control scheme with increased overall cost. Furthermore, the output voltage and efficiency are reduced due to the self-parasitic behavior of power circuit components. To overcome these drawbacks, this manuscript provides, the theoretical development and hardware implementation of DC–DC step-up (boost power converter circuit for obtaining extra output-voltage high-performance. The proposed circuit substantially improves the high output-voltage by voltage-lift technology with a closed loop proportional–integral controller. This complete numerical model of the converter circuit including closed loop P-I controller is developed in simulation (Matlab/Simulink software and the hardware prototype model is implemented with digital signal processor (DSP TMS320F2812. A detailed performance analysis was carried out under both line and load regulation conditions. Numerical simulation and its verification results provided in this paper, prove the good agreement of the circuit with theoretical background.

  12. Benchmarking of Voltage Sag Generators

    DEFF Research Database (Denmark)

    Yang, Yongheng; Blaabjerg, Frede; Zou, Zhixiang

    2012-01-01

    The increased penetration of renewable energy systems, like photovoltaic and wind power systems, rises the concern about the power quality and stability of the utility grid. Some regulations for Low Voltage Ride-Through (LVRT) for medium voltage or high voltage applications, are coming into force...... to guide these grid-connected distributed power generation systems. In order to verify the response of such systems for voltage disturbance, mainly for evaluation of voltage sags/dips, a Voltage Sag Generator (VSG) is needed. This paper evaluates such sag test devices according to IEC 61000 in order...... to provide cheaper solutions to test against voltage sags. Simulation and experimental results demonstrate that the shunt impedance based VSG solution is the easiest and cheapest one for laboratory test applications. The back-to-back fully controlled converter based VSG is the most flexible solution...

  13. Properties of zirconia thin layers elaborated by high voltage anodisation in view of SOFC application

    Energy Technology Data Exchange (ETDEWEB)

    Montero, Xabier; Pauporte, Thierry; Ringuede, Armelle; Cassir, Michel [Laboratoire d' Electrochimie et Chimie Analytique, UMR-CNRS 7575, Ecole Nationale Superieure de Chimie de Paris, 11, rue P. et M. Curie, 75231 Paris Cedex 05 (France); Vannier, Rose-Noelle [Laboratoire de Cristallochimie et Physicochimie du Solide ENSCL-BP, 59652 Villeneuve d' Ascq Cedex 108 (France)

    2005-10-10

    In order to adapt the anodisation technique to SOFC application, zirconium and zirconium-niobium alloys were tested in various electrolytic media and applied potentials (up to 420V). The elaborated ZrO{sub 2} insulating layers were characterised in situ by electrochemical impedance spectroscopy and their thicknesses were determined as ranging up to 1{mu}m. The effect of thermal annealing treatment of layers prepared in various experimental conditions was investigated by X-ray diffraction (XRD) and solid-state electrochemical impedance spectroscopy in a planar configuration. The effect of the growing conditions on significant parameters such as zirconia crystallite size, zirconia conductivity and activation energy were deduced up to 800{sup o}C. The possibility of using the anodisation process for fuel cell devices is discussed. This study demonstrates that it surely requires the use of more efficient dopants, such as yttria. (author)

  14. Application of atomic absorption spectroscopy for detection of multimetal traces in low-voltage electrical marks.

    Science.gov (United States)

    Jakubeniene, Marija; Zakaras, Algirdas; Minkuviene, Zita Nijole; Benoshys, Alvydas

    2006-08-10

    Application of atomic absorption spectroscopy to detect multimetal traces in injured skin is a promising tool for investigation of fatalities caused by electrocution. The present paper is aimed at testing the reliability of this method for metal traces detection in electric current marks and is focused on study of peculiarities of metal penetration into the skin exposed to a current impact. Bare aluminum wire, tin-lead coated copper multistrand wire, and zinc-plated steel rope were used to make electrical marks on pig skin. It is demonstrated that amount of copper, zinc, lead, and iron may serve as statistically reliable indicators for the type of wire, which caused the electrical mark, in spite of the background content of these metals in the skin without injury. Different penetration rates for different metals contained in the wire inflicting an electrical mark were observed.

  15. EGIS - An Environmental GIS Developed for NASA Field Center Applications

    Science.gov (United States)

    Smoot, James; Cohan, Tyrus; O'Connor, Christina; Johnson, Gary; Carr, Hugh

    2001-01-01

    As the principal center for Environmental Geographic Information Systems (EGIS), the John C. Stennis Space Center (SSC), located in Hancock County, Mississippi, has been assigned technical support requirements to design and to implement a basic EGIS data base for all NASA Field Centers. The intent of this Phase I effort is to produce a baseline EGIS data base incorporating newly available remotely sensed data as well as existing environmental data. A example application of the use of the data base at Stennis Space Center will be to illustrate baseline environmental conditions for consideration with proposed propulsion test stand development and operation. To effectively answer questions related to environmental issues at each center, organization of the data layers and sources will include the following categories: Cadastral/Geodetic; Geopolitical; Hydrography; Infrastructure; Physical Geography; Socioeconomic; Remote Sensing Imagery; Associated Metadata. As part of a Phase II effort, site-specific data and applications will be implemented and added to the data base at each Field Center. This poster illustrates the framework of the design and implementation of a basic EGIS data base. Shown are example data sources, hardware and software, and data base delivery and installation. The poster also depicts future recommendations for a centrally located server to house each of the NASA Field Center data bases. The server will allow real-time data base updates with additional layers and models for each center. Expansion of the EGIS data base will continue to grow as site-specific applications are developed addressing the ongoing evolution of environmental concerns at all NASA Field Centers.

  16. Mechanical properties of carbon fiber composites for environmental applications

    Energy Technology Data Exchange (ETDEWEB)

    Andrews, R.; Grulke, E.; Kimber, G. [Univ. of Kentucky, Lexington, KY (United States)

    1996-12-31

    Activated carbon fiber composites show great promise as fixed-bed catalytic reactors for use in environmental applications such as flue gas clean-up and ground water decontamination. A novel manufacturing process produces low density composites from chopped carbon fibers and binders. These composites have high permeability, can be activated to have high surface area, and have many potential environmental applications. This paper reports the mechanical and flow properties of these low density composites. Three point flexural strength tests were used to measure composite yield strength and flexural moduli. Composites containing over 10 pph binder had an adequate yield strength of about 200 psi at activations up to 40% weight loss. The composites were anisotropic, having along-fiber to cross-fiber yield strength ratios between 1.2 and 2.0. The pressure drop of air through the composites correlated with the gas velocity, and showed a dependence on sample density.

  17. Mechanical properties of carbon fiber composites for environmental applications

    Energy Technology Data Exchange (ETDEWEB)

    Andrews, R.; Grulke, E. [Univ. of Kentucky, Lexington, KY (United States)

    1996-10-01

    Activated carbon fiber composites show great promise as fixed-bed catalytic reactors for use in environmental applications such as flue gas clean-up and ground water decontamination. A novel manufacturing process produces low density composites from chopped carbon fibers and binders. These composites have high permeability, can be activated to have high surface area, and have many potential environmental applications. This paper reports the mechanical and flow properties of these low density composites. Three point flexural strength tests were used to measure composite yield strength and flexural moduli. Composites containing over 10 pph binder had an adequate yield strength of about 200 psi at activations up to 40% weight loss. The composites were anisotropic, having along-fiber to cross-fiber yield strength ratios between 1.2 and 2.0. The friction factor for flow through the composites can be correlated using the fiber Reynolds number, and is affected by the composite bulk density.

  18. Utilizing steel slag in environmental application - An overview

    Science.gov (United States)

    Lim, J. W.; Chew, L. H.; Choong, T. S. Y.; Tezara, C.; Yazdi, M. H.

    2016-06-01

    Steel slags are generated as waste material or byproduct every day from steel making industries.The potential environmental issues which are related with the slag dump or reprocessing for metal recovery are generally being focused in the research. However the chemistry and mineralogy of slag depends on metallurgical process which is able to determine whether the steel slag can be the reusable products or not. Nowadays, steel slag are well characterized by using several methods, such as X-ray Diffraction, ICP-OES, leaching test and many more. About the industrial application, it is mainly reused as aggregate for road construction, as armour stones for hydraulic engineering constructions and as fertilizers for agricultural purposes. To ensure the quality of steel slag for the end usage, several test methods are developed for evaluating the technical properties of steel slag, especially volume stability and environmental behaviour. In order to determine its environmental behaviour, leaching tests have been developed. The focus of this paper however is on those applications that directly affect environmental issues including remediation, and mitigation of activities that negatively impact the environment.

  19. Applications of passive remote surface acoustic wave sensors in high-voltage systems; Einsatz von passiven funkabfragbaren Oberflaechenwellensensoren in der elektrischen Energietechnik

    Energy Technology Data Exchange (ETDEWEB)

    Teminova, R.

    2007-06-29

    Passive remote Surface Acoustic Wave (SAW) sensors have been applied e.g. as temperature, pressure or torque sensors. Their important advantages over standard methods are their passive operating principle, which allows operation without any power supply, as well as the wireless high-frequency signal transmission over distances up to about 10..15 m even through (non metallic) housings. These properties of SAW sensors particularly qualify them for applications in high voltage operational equipment. First experience was gained in a long time field test of surge arrester monitoring based on SAW temperature sensors in a German high-voltage substation. Now, this system has been further developed at Darmstadt University of Technology for other applications, the first of them being an overhead line (OHL) conductor temperature measurement, the second one a temperature monitoring system for of high-voltage disconnectors. After designing and building the sensors, extensive laboratory tests were carried out applying high-voltage, high-current and thermal stress in order to approve the suitability for the intended application. All these tests confirmed the assumption that SAW sensors, due to their passive working principle, are not affected at all by any kind of electrical, magnetic or thermal stress that may occur during service. The complete temperature sensor consists of three parts: a sensor chip, an antenna which receives and transmits the signal from and to the radar unit and a body for installation and for protection against environmental impact. One must find a good compromise between optimizing of thermal, dielectric and high-frequency characteristics and at the same time taking into consideration a simple installation. These requirements on the SAW sensors turned out to be difficult to coordinate. To achieve a high measuring precision is especially difficult. First, a new sensor for OHL application was developed. The OHL conductor temperature sensor had been optimized

  20. Analyzing of Dynamic Voltage Restorer in Series Compensation Voltage

    Directory of Open Access Journals (Sweden)

    Naser Parhizgar

    2012-02-01

    Full Text Available The Dynamic Voltage Restorer (DVR is a series-connected compensator to generate a controllable voltage to against the short-term voltage disturbances. The technique of DVR is an effective and cost competitive approach to improve voltage quality at the load side. This study presents a single-phase and threephase DVR system with reduced switch-count topology to protect the sensitive load against abnormal voltage conditions. Most basic function, the DVR configuration consist of a two level Voltage Source Converter (VSC, a dc energy storage device, a coupling transformer Connected in shunt with the ac system This study presents the application of Dynamic Voltage Restorer (DVR on power distribution systems for mitigation of voltage sag at critical loads. DVR is one of the compensating types of custom power devices. The DVR, which is based on forced-commutated Voltage Source Converter (VSC has been proved suitable for the task of compensating voltage sags/swells. Simulation results are presented to illustrate and understand the performances of DVR in supporting load voltages under voltage sags/swells conditions.

  1. Nuclear magnetic resonance in environmental engineering: principles and applications.

    Science.gov (United States)

    Lens, P N; Hemminga, M A

    1998-01-01

    This paper gives an introduction to nuclear magnetic resonance spectroscopy (NMR) and magnetic resonance imaging (MRI) in relation to applications in the field of environmental science and engineering. The underlying principles of high resolution solution and solid state NMR, relaxation time measurements and imaging are presented. Then, the use of NMR is illustrated and reviewed in studies of biodegradation and biotransformation of soluble and solid organic matter, removal of nutrients and xenobiotics, fate of heavy metal ions, and transport processes in bioreactor systems.

  2. Workshop on environmental and energy applications of neural networks

    Energy Technology Data Exchange (ETDEWEB)

    Hashem, S.

    1995-03-01

    This report consists of the abstracts for the papers given at the conference. Applications of neural networks in the environmental, energy and biomedical fields are discussed. Some of the topics covered are: predicting atmospheric pollutant concentrations due to fossil-fired electric power generation; hazardous waste characterization; nondestructive TRU (transuranic) waste assay; risk analysis; load forecasting for electric utilities; design of a wind power storage and generation system; nuclear fuel management; etc.

  3. Low-voltage gyrotrons

    Science.gov (United States)

    Glyavin, M. Yu.; Zavolskiy, N. A.; Sedov, A. S.; Nusinovich, G. S.

    2013-03-01

    For a long time, the gyrotrons were primarily developed for electron cyclotron heating and current drive of plasmas in controlled fusion reactors where a multi-megawatt, quasi-continuous millimeter-wave power is required. In addition to this important application, there are other applications (and their number increases with time) which do not require a very high power level, but such issues as the ability to operate at low voltages and have compact devices are very important. For example, gyrotrons are of interest for a dynamic nuclear polarization, which improves the sensitivity of the nuclear magnetic resonance spectroscopy. In this paper, some issues important for operation of gyrotrons driven by low-voltage electron beams are analyzed. An emphasis is made on the efficiency of low-voltage gyrotron operation at the fundamental and higher cyclotron harmonics. These efficiencies calculated with the account for ohmic losses were, first, determined in the framework of the generalized gyrotron theory based on the cold-cavity approximation. Then, more accurate, self-consistent calculations for the fundamental and second harmonic low-voltage sub-THz gyrotron designs were carried out. Results of these calculations are presented and discussed. It is shown that operation of the fundamental and second harmonic gyrotrons with noticeable efficiencies is possible even at voltages as low as 5-10 kV. Even the third harmonic gyrotrons can operate at voltages about 15 kV, albeit with rather low efficiency (1%-2% in the submillimeter wavelength region).

  4. Applications of neural networks in environmental and energy sciences and engineering. Proceedings of the 1995 workshop on environmental and energy applications of neural networks

    Energy Technology Data Exchange (ETDEWEB)

    Hashem, S.; Keller, P.E.; Kouzes, R.T.; Kangas, L.J.

    1995-12-31

    These proceedings contain edited versions of the technical presentations of the Workshop on Environmental and Energy Applications of Neural Networks, held on March 30--31, 1995, in Richland, Washington. The purpose of the workshop was to provide a forum for discussing environmental, energy, and biomedical applications of neural networks. Panels were held to discuss various research and development issues relating to real-world applications in each of the three areas. The applications covered in the workshop were: Environmental applications -- modeling and predicting soil, air and water pollution, environmental sensing, spectroscopy, hazardous waste handling and cleanup; Energy applications -- process monitoring and optimization of power systems, modeling and control of power plants, environmental monitoring for power systems, power load forecasting, fault location and diagnosis of power systems; and Biomedical applications -- medical image and signal analysis, medical diagnosis, analysis of environmental health effects, and modeling biological systems. Selected papers are indexed separately for inclusion in the Energy Science and Technology Database.

  5. A Low-Power Voltage Limiter/Regulator IC in Standard Thick-Oxide 130 nm CMOS for Inductive Power Transfer Application

    Directory of Open Access Journals (Sweden)

    Stepan Lapshev

    2014-01-01

    Full Text Available This paper presents a novel CMOS low-power voltage limiter/regulator circuit with hysteresis for inductive power transfer in an implanted telemetry application. The circuit controls its rail voltage to the maximum value of 3 V DC employing 100 mV of comparator hysteresis. It occupies a silicon area of only 127 µm × 125 µm using the 130 nm IBM CMOS process. In addition, the circuit dissipated less than 1 mW and was designed using thick-oxide 3.6 V NMOS and PMOS devices available in the process library.

  6. Output stages inside a negative feedback loop: application to a low-voltage three-phase DC-AC converter for educational purposes

    CERN Document Server

    Llopis, Francisco

    2013-01-01

    The circuit presented in this paper aims at providing three 40 Vpp 50Hz AC voltages sources with 120-degree phase separation between them. This is a fully analogue circuit that uses standard, low-cost electronic components without resorting to a microcontroller as previously proposed by Shirvasar et al [1]. This circuit may serve as a basis for a low-voltage 3P-AC power supply that students may safely use to realize experiments, i.e. about the principles and applications of three-phase AC power lines, without the risk of electric shocks.

  7. Characterisation of charge voltage of lead-acid batteries: application to the charge control strategy in photovoltaic systems

    Energy Technology Data Exchange (ETDEWEB)

    Vela, N. [CIEMAT-DER, Madrid (Spain). Laboratorio de Energia Solar Fotovoltaica; Aguilera, J. [Universidad de Jaen (Spain). Escuela Politecnica Superior

    2006-12-15

    In stand-alone photovoltaic (PV) systems, charge controllers prevent excessive battery overcharge by interrupting or limiting the current flow from the PV array to the battery when the battery becomes fully charged. Charge regulation is most often accomplished by limiting the battery voltage to a predetermined value or cut-off voltage, higher than the gassing voltage. These regulation voltages are dependent on the temperature and battery charge current. An adequate selection of overcharge cut-off voltage for each battery type and operating conditions would maintain the highest battery state of charge without causing significant overcharge thus improving battery performance and reliability. To perform this work, a sample of nine different lead-acid batteries, typically used in stand-alone PV systems including vented and sealed batteries with 2 V cells and monoblock configurations have been selected. This paper presents simple mathematical expressions fitting two charge characteristic voltages: the gassing voltage (V{sub g}) and the end-of charge voltage (V{sub fc}) as function of charge current and temperature for the tested batteries. With these expressions, we have calculated V{sub g} and V{sub fc} at different current rates. An analysis of the different values obtained is presented here focusing in the implication in control strategies of batteries in stand-alone PV systems. (author)

  8. PROBLEMS OF ECONOMIC CRITERIA APPLICATION TO CALCULATION AND DESIGN OF HIGH-VOLTAGE PLASTIC-INSULATED POWER CABLES

    Directory of Open Access Journals (Sweden)

    O.V. Golik

    2013-09-01

    Full Text Available Results of cable transmitting capacity calculation for voltage of up to 220 kV are analyzed. The work is devoted to creation of a current rating calculation technique for high-voltage cross-linked polyethylene cables.

  9. Loading Analysis of Modular Multi-level Converter for Offshore High-voltage DC Application under Various Grid Faults

    DEFF Research Database (Denmark)

    Liu, Hui; Ma, Ke; Loh, Poh Chiang;

    2016-01-01

    The modular multi-level converter has become an interesting candidate in high-voltage DC systems due to its higher voltage levels and modular construction. Low-voltage ride-through is an important grid requirement for modular multi-level converter–high-voltage DC since not only causes control...... challenges but may also result in overstressed components for the modular multi-level converter. However, the thermal loading of the modular multi-level converter under various grid faults has not yet been clarified. In this article, the power loss and thermal performance of the modular multi-level converter...... during grid voltage dips are studied. The impacts of two typical grid faults to the modular multi-level converter in terms of operating and loading conditions are analytically researched and simulated. It has been found that the operating and loading conditions of the modular multi-level converter under...

  10. Charge-pump voltage converter

    Science.gov (United States)

    Brainard, John P.; Christenson, Todd R.

    2009-11-03

    A charge-pump voltage converter for converting a low voltage provided by a low-voltage source to a higher voltage. Charge is inductively generated on a transfer rotor electrode during its transit past an inductor stator electrode and subsequently transferred by the rotating rotor to a collector stator electrode for storage or use. Repetition of the charge transfer process leads to a build-up of voltage on a charge-receiving device. Connection of multiple charge-pump voltage converters in series can generate higher voltages, and connection of multiple charge-pump voltage converters in parallel can generate higher currents. Microelectromechanical (MEMS) embodiments of this invention provide a small and compact high-voltage (several hundred V) voltage source starting with a few-V initial voltage source. The microscale size of many embodiments of this invention make it ideally suited for MEMS- and other micro-applications where integration of the voltage or charge source in a small package is highly desirable.

  11. A Manufacturing Cost and Supply Chain Analysis of SiC Power Electronics Applicable to Medium-Voltage Motor Drives

    Energy Technology Data Exchange (ETDEWEB)

    Horowitz, Kelsey [National Renewable Energy Lab. (NREL), Golden, CO (United States); Remo, Timothy [National Renewable Energy Lab. (NREL), Golden, CO (United States); Reese, Samantha [National Renewable Energy Lab. (NREL), Golden, CO (United States)

    2017-03-24

    Wide bandgap (WBG) semiconductor devices are increasingly being considered for use in certain power electronics applications, where they can improve efficiency, performance, footprint, and, potentially, total system cost compared to systems using traditional silicon (Si) devices. Silicon carbide (SiC) devices in particular -- which are currently more mature than other WBG devices -- are poised for growth in the coming years. Today, the manufacturing of SiC wafers is concentrated in the United States, and chip production is split roughly equally between the United States, Japan, and Europe. Established contract manufacturers located throughout Asia typically carry out manufacturing of WBG power modules. We seek to understand how global manufacturing of SiC components may evolve over time by illustrating the regional cost drivers along the supply chain and providing an overview of other factors that influence where manufacturing is sited. We conduct this analysis for a particular case study where SiC devices are used in a medium-voltage motor drive.

  12. Design and Implementation of a Power Converter to Process Renewable Energy for Step-down Voltage Applications

    Directory of Open Access Journals (Sweden)

    Chih-Lung Shen

    2014-04-01

    Full Text Available In this study a power converter to process renewable energy is proposed, which can not only process solar energy but deal with wind power. The proposed converter is derived from two series modified forwards to step down voltage for charger system or dc distribution application, so as called Modified-Forward Dual-Input Converter (MFDIC. The MFDIC mainly contains an upper Modified Forward (MF, a lower MF, a common output inductor and a DSP-based system controller. The upper and lower MFs can operate individually or simultaneously to accommodate the variation of atmospheric conditions. Since the MFDIC can process renewable power with interleaved operation, the ripple of output current is suppressed significantly and thus better performance is achieved. In the MFDIC only a common output inductor is needed, instead of two separated inductors, so that the volume of the converter is reduced significantly. To draw maximum power from PV panel and wind turbine, perturb-and-observe method is adopted to achieve the feature of Maximum Power Point Tracking (MPPT. The MFDIC is constructed, designed, analyzed, simulated and tested. Simulations and practical measurements have demonstrated the validity and the feasibility of the proposed dual-input converter.

  13. OPTIMIZATION OF SURFACE RESISTIVITY AND RELATIVE PERMITTIVITY OF SILICONE RUBBER FOR HIGH VOLTAGE APPLICATION USING RESPONSE SURFACE METHODOLOGY

    Directory of Open Access Journals (Sweden)

    N.N. Ali

    2017-06-01

    said that the materials formulation and processing parameters had significantly influenced the performance of SiR blends and thus, having the optimized material composition and processing parameters is required in producing an insulator with great function ability for high voltage application.

  14. Database application for changing data models in environmental engineering

    Energy Technology Data Exchange (ETDEWEB)

    Hussels, Ulrich; Camarinopoulos, Stephanos; Luedtke, Torsten; Pampoukis, Georgios [RISA Sicherheitsanalysen GmbH, Berlin-Charlottenburg (Germany)

    2013-07-01

    Whenever a technical task is to be solved with the help of a database application and uncertainties regarding the structure, scope or level of detail of the data model exist (either currently or in the future) the use of a generic database application can reduce considerably the cost of implementation and maintenance. Simultaneously the approach described in this contribution permits the operation with different views on the data and even finding and defining new views which had not been considered before. The prerequisite for this is that the preliminary information (structure as well as data) stored into the generic application matches the intended use. In this case, parts of the generic model developed with the generic approach can be reused and according efforts for a major rebuild can be saved. This significantly reduces the development time. At the same time flexibility is achieved concerning the environmental data model, which is not given in the context of conventional developments. (orig.)

  15. Space Life Support Technology Applications to Terrestrial Environmental Problems

    Science.gov (United States)

    Schwartzkopf, Steven H.; Sleeper, Howard L.

    1993-01-01

    Many of the problems now facing the human race on Earth are, in fact, life support issues. Decline of air Quality as a result of industrial and automotive emissions, pollution of ground water by organic pesticides or solvents, and the disposal of solid wastes are all examples of environmental problems that we must solve to sustain human life. The technologies currently under development to solve the problems of supporting human life for advanced space missions are extraordinarily synergistic with these environmental problems. The development of these technologies (including both physicochemical and bioregenerative types) is increasingly focused on closing the life support loop by removing and recycling contaminants and wastes to produce the materials necessary to sustain human life. By so doing, this technology development effort also focuses automatically on reducing resupply logistics requirements and increasing crew safety through increased self-sufficiency. This paper describes several technologies that have been developed to support human life in space and illustrates the applicability of the technologies to environmental problems including environmental remediation and pollution prevention.

  16. Design and Tuning of Wind Power Plant Voltage Controller with Embedded Application of Wind Turbines and STATCOMs

    DEFF Research Database (Denmark)

    Petersen, Lennart; Kryezi, Fitim; Iov, Florin

    2017-01-01

    . A complete phasor model of the entire wind power plant is constructed, being appropriate for voltage control assessment. An exemplary wind power plant located in the United Kingdom and the corresponding grid code requirements are used as a base case. The final design and tuning process of the voltage...... controller results in a guidance, proposed for this particular control architecture. It provides qualitative outcomes regarding the parametrisation of each individual control loop and how to adjust the voltage controller depending on different grid stiffnesses of the wind power plant connection...

  17. Application of thyristor in voltage regulation%晶闸管在调压技术中的应用

    Institute of Scientific and Technical Information of China (English)

    刘晓青; 刘伟

    2011-01-01

    阐述了晶闸管的工作特性,主要从晶闸管整流电路和晶闸管交流调压电路两方面,分析了如何利用晶闸管的特性进行调压.%The paper described the work characteristics of the thyristor, and analyzed how to adjust the voltage using the characteristics of the thyristor, mainly including rectifier circuit and Ac voltage regulation circuit with thyristors. Analysis showed that voltage controllers with thyristors are widely used in various industries because of its simpleness and practicality.

  18. 10 CFR 63.24 - Updating of application and environmental impact statement.

    Science.gov (United States)

    2010-01-01

    ... 10 Energy 2 2010-01-01 2010-01-01 false Updating of application and environmental impact statement... Updating of application and environmental impact statement. (a) The application must be as complete as... the time a construction authorization was issued. (c) DOE shall supplement its environmental impact...

  19. 4th European Conference on Geostatistics for Environmental Applications

    CERN Document Server

    Carrera, Jesus; Gómez-Hernández, José

    2004-01-01

    The fourth edition of the European Conference on Geostatistics for Environmental Applications (geoENV IV) took place in Barcelona, November 27-29, 2002. As a proof that there is an increasing interest in environmental issues in the geostatistical community, the conference attracted over 100 participants, mostly Europeans (up to 10 European countries were represented), but also from other countries in the world. Only 46 contributions, selected out of around 100 submitted papers, were invited to be presented orally during the conference. Additionally 30 authors were invited to present their work in poster format during a special session. All oral and poster contributors were invited to submit their work to be considered for publication in this Kluwer series. All papers underwent a reviewing process, which consisted on two reviewers for oral presentations and one reviewer for posters. The book opens with one keynote paper by Philippe Naveau. It is followed by 40 papers that correspond to those presented orally d...

  20. Artificial Neural Network Application for Power Transfer Capability and Voltage Calculations in Multi-Area Power System

    Directory of Open Access Journals (Sweden)

    Palukuru NAGENDRA

    2010-12-01

    Full Text Available In this study, the use of artificial neural network (ANN based model, multi-layer perceptron (MLP network, to compute the transfer capabilities in a multi-area power system was explored. The input for the ANN is load status and the outputs are the transfer capability among the system areas, voltage magnitudes and voltage angles at concerned buses of the areas under consideration. The repeated power flow (RPF method is used in this paper for calculating the power transfer capability, voltage magnitudes and voltage angles necessary for the generation of input-output patterns for training the proposed MLP neural network. Preliminary investigations on a three area 30-bus system reveal that the proposed model is computationally faster than the conventional method.

  1. Application of Metal Oxide Surge Arrester on the Non-Conventional Chaotic Ferroresonance Oscillation in Voltage Transformers

    Directory of Open Access Journals (Sweden)

    Hamid Radmanesh

    2012-09-01

    Full Text Available In this study the effect of MOSA on controlling of the non-conventional ferroresonance overvoltage in the iron core voltage transformer is studied. It is expected that MOSA can generally damp ferroresonance overvoltages. Time-domain study is used to analyze this effect. Study is done on a voltage transformer rated 100VA, 275 kV. The magnetization characteristic of the transformer coil is modeled by a single-parameter twoterm polynomial with q = 7 degree of nonlinearity. Core loss is modeled by linear resistance. Simulation results show that connecting the MOSA in parallel to the voltage transformer, shows a great controlling effect of the ferroresonance oscillations. Phase plane, time domain voltage waveforms, FFT analysis and bifurcation diagrams are also given. Significant effect on settling down to the chaos, the range of parameter values that may lead to ferroresonance overvoltages and controlling these phenomena are obtained and presented.

  2. Isomerically Pure Tetramethylrhodamine Voltage Reporters.

    Science.gov (United States)

    Deal, Parker E; Kulkarni, Rishikesh U; Al-Abdullatif, Sarah H; Miller, Evan W

    2016-07-27

    We present the design, synthesis, and application of a new family of fluorescent voltage indicators based on isomerically pure tetramethylrhodamines. These new Rhodamine Voltage Reporters, or RhoVRs, use photoinduced electron transfer (PeT) as a trigger for voltage sensing, display excitation and emission profiles in the green to orange region of the visible spectrum, demonstrate high sensitivity to membrane potential changes (up to 47% ΔF/F per 100 mV), and employ a tertiary amide derived from sarcosine, which aids in membrane localization and simultaneously simplifies the synthetic route to the voltage sensors. The most sensitive of the RhoVR dyes, RhoVR 1, features a methoxy-substituted diethylaniline donor and phenylenevinylene molecular wire at the 5'-position of the rhodamine aryl ring, exhibits the highest voltage sensitivity to date for red-shifted PeT-based voltage sensors, and is compatible with simultaneous imaging alongside green fluorescent protein-based indicators. The discoveries that sarcosine-based tertiary amides in the context of molecular-wire voltage indicators prevent dye internalization and 5'-substituted voltage indicators exhibit improved voltage sensitivity should be broadly applicable to other types of PeT-based voltage-sensitive fluorophores.

  3. Preparation and Application of New Porous Environmental Ceramics Filter Medium

    Institute of Scientific and Technical Information of China (English)

    LI Meng; WU Jianfeng; JIN Jianhua; LIU Xinming

    2005-01-01

    A new kind of environmental ceramics medium which was made of industrial solid wastes discharged by Shandong Alum Corporation has been used in the process of drinking water treatment. New techniques were introduced to ensure its remarkable advantages such as high porosity and strength. The results of practical application show that this sort of filter medium has shorter filtration run, shorter mature period and higher filter deposit capability compared with traditional sand filter medium. Moreover, up to 25%- 30% of the daily running costs are expected to be reduced by using this ceramics medium.

  4. Biomedical and environmental applications of laser-induced breakdown spectroscopy

    Indian Academy of Sciences (India)

    V K Unnikrishnan; K S Choudhari; Suresh D Kulkarni; Rajesh Nayak; V B Kartha; C Santhosh; B M Suri

    2014-02-01

    Laser-induced breakdown spectroscopy (LIBS) is an emerging analytical technique with numerous advantages such as rapidity, multi-elemental analysis, minimal sample preparation, minimal destruction, low cost and versatility of being applied to a wide range of materials. In this paper, we report the preliminary observations we obtained using LIBS for clinical and environmental samples. Elemental analysis has been done qualitatively in human teeth samples which show encouraging results. It has also been demonstrated in this paper that LIBS can be very well utilized in field applications such as plastic waste sorting and recycling.

  5. Design of advanced photocatalytic materials for energy and environmental applications

    CERN Document Server

    Coronado, Juan M; Hernández-Alonso, María D; Portela, Raquel

    2013-01-01

    Research for the development of more efficient photocatalysts has experienced an almost exponential growth since its popularization in early 1970's. Despite the advantages of the widely used TiO2, the yield of the conversion of sun power into chemical energy that can be achieved with this material is limited prompting the research and development of  a number of structural, morphological and chemical modifications of TiO2 , as well as a number of novel photocatalysts with very different composition. Design of Advanced Photocatalytic Materials for Energy and Environmental Applications provides

  6. Fiber optic sensors for environmental applications: A brief review

    Energy Technology Data Exchange (ETDEWEB)

    Rossabi, J.

    1992-04-01

    Understanding the flow a groundwater quality. This understanding is achieved by measurement of the appropriate chemical and physical subsurface parameters. The ideal measurement would accurately assess a parameter without affecting the parameter or its environment. Fiber optic spectroscopy offers some of the most promising techniques for accurate, non-invasive measurements of environmental parameters. Fiber optic sensors for subsurface applications are currently being developed by several Department of Energy laboratories. Some of these sensors have been successfully deployed in the field and are attaining the goals of accurate, noninvasive, real time measurements in the subsurface.

  7. Studies on time series applications in environmental sciences

    CERN Document Server

    Bărbulescu, Alina

    2016-01-01

    Time series analysis and modelling represent a large study field, implying the approach from the perspective of the time and frequency, with applications in different domains. Modelling hydro-meteorological time series is difficult due to the characteristics of these series, as long range dependence, spatial dependence, the correlation with other series. Continuous spatial data plays an important role in planning, risk assessment and decision making in environmental management. In this context, in this book we present various statistical tests and modelling techniques used for time series analysis, as well as applications to hydro-meteorological series from Dobrogea, a region situated in the south-eastern part of Romania, less studied till now. Part of the results are accompanied by their R code. .

  8. Environmental and industrial applications of pulsed power systems

    Energy Technology Data Exchange (ETDEWEB)

    Neau, E.L.

    1993-10-01

    The technology base formed by the development of high peak power simulators, laser drivers, free electron lasers (FEL`s), and Inertial Confinement Fusion (ICF) drivers from the early 60`s through the late 80`s is being extended to high average power short-pulse machines with the capabilities of performing new roles in environmental cleanup applications and in supporting new types of industrial manufacturing processes. Some of these processes will require very high average beam power levels of hundreds of kilowatts to perhaps megawatts. In this paper we briefly discuss new technology capabilities and then concentrate on specific application areas that may benefit from the high specific energies and high average powers attainable with short-pulse machines.

  9. Searching for reciclability of modified clays for an environmental application

    Science.gov (United States)

    Del Hoyo Martínez, Carmen; Solange Lozano García, Marina; Sánchez Escribano, Vicente; Antequera, Jorge

    2014-05-01

    Thanks to the development of the science and the technology of the nourishment in the last 50 years, there have revealed itself several new substances that can fulfill beneficial functions in the food, and these substances, named food additives, are today within reach of all. The food additives recover a very important role in the complex nourishing supply. The additives fulfill several useful functions in the food, which often we give for sat. Nevertheless the widespread use of food additives in the food production also influences the public health. The food industries, which are very important for the economy, spill residues proved from its activity that they have to be controlled to evaluate the environmental impact and to offer the necessary information about the quantitative evaluation of the chemical risk of the use of food additives for the public health. The clay materials have led to numerous applications in the field of public health (del Hoyo, 2007; Volzone, 2007) having been demonstrated its effectiveness as adsorbents of all contaminants. Some biodegradable materials are used for for adsorption of chemical contaminants: lignins (Valderrabano et al., 2008) and also clays and clay minerals, whose colloidal properties, ease of generating structural changes, abundance in nature, and low cost make them very suitable for this kind of applications. Among the strategies used at present to preserve the quality of the water and this way to diminish the environmental risk that supposes the chemical pollution, stands out the use of adsorbents of under cost, already they are natural or modified, to immobilize these compounds and to avoid the pollution of the water with the consequent reduction of environmental and economic costs. We have studied the adsorption of several contaminants related to the food industry by natural or modified clays, searching their interaction mechanisms and the possible recycling of these materials for environmental purposes and

  10. Environmental applications of ion chromatography in Eastern and Central Europe.

    Science.gov (United States)

    Michalski, Rajmund

    2010-08-01

    Environmental analytics is one of the most important applications of ion chromatography. It includes determination of ions in water and wastewater as well as in gaseous and solid ones. Nowadays, ion chromatography has almost completely displaced the classical methods of ion determination in these areas. In spite of the fact that the ion chromatography has been officially present in the scientific world for 36 years, its role and popularity is highly diversified in various countries and regions of the world. In highly industrialized countries, it has been a reference method of water and wastewater analysis for years. In other parts of the world, it is not used and appreciated sufficiently despite its undeniable advantages. The following paper is a short overview of the most highly cited scientific and research institutions that conduct research in terms of environmental applications of ion chromatography in Eastern and Central Europe. Furthermore, the paper presents a list of a number of scientific papers referring to the discussed area, published in the years 1996-2009 in some of the most highly cited international scientific journals, and concerning publications of scientists from Eastern and Central Europe seen against the background of Europe and the world.

  11. Applications of flow cytometry in environmental microbiology and biotechnology.

    Science.gov (United States)

    Bergquist, Peter L; Hardiman, Elizabeth M; Ferrari, Belinda C; Winsley, Tristrom

    2009-05-01

    Flow cytometry (FCM) is a technique for counting, examining and sorting microscopic particles suspended in a stream of fluid. It uses the principles of light scattering, light excitation and the emission from fluorescent molecules to generate specific multiparameter data from particles and cells. The cells are hydrodynamically focussed in a sheath solution before being intercepted by a focused light source provided by a laser. FCM has been used primarily in medical applications but is being used increasingly for the examination of individual cells from environmental samples. It has found uses in the isolation of both culturable and hitherto non-culturable bacteria present infrequently in environmental samples using appropriate growth conditions. FCM lends itself to high-throughput applications in directed evolution for the analysis of single cells or cell populations carrying mutant genes. It is also suitable for encapsulation studies where individual bacteria are compartmentalised with substrate in water-in-oil-in-water emulsions or with individual genes in transcriptional/translational mixtures for the production of mutant enzymes. The sensitivity of the technique has allowed the examination of gene optimisation by a procedure known as random or neutral drift where screening and selection is based on the retention of some predetermined level of activity through multiple rounds of mutagenesis.

  12. A rugged 650 V SOI-based high-voltage half-bridge IGBT gate driver IC for motor drive applications

    Science.gov (United States)

    Hua, Qing; Li, Zehong; Zhang, Bo; Chen, Weizhong; Huang, Xiangjun; Feng, Yuxiang

    2015-05-01

    This paper proposes a rugged high-voltage N-channel insulated gate bipolar transistor (IGBT) gate driver integrated circuit. The device integrates a high-side and a low-side output stages on a single chip, which is designed specifically for motor drive applications. High-voltage level shift technology enables the high-side stage of this device to operate up to 650 V. The logic inputs are complementary metal oxide semiconductor (CMOS)/transistor transistor logic compatible down to 3.3 V. Undervoltage protection functionality with hysteresis characteristic has also been integrated to enhance the device reliability. The device is fabricated in a 1.0 μm, 650 V high-voltage bipolar CMOS double-diffused metal oxide semiconductor (BCD) on silicon-on-insulator (SOI) process. Deep trench dielectric isolation technology is employed to provide complete electrical isolation with advantages such as reduced parasitic effects, excellent noise immunity and low leakage current. Experimental results show that the isolation voltage of this device can be up to approximately 779 V at 25°C, and the leakage current is only 5 nA at 650 V, which is 15% higher and 67% lower than the conventional ones. In addition, it delivers an excellent thermal stability and needs very low quiescent current and offers a high gate driver capability which is needed to adequately drive IGBTs that have large input capacitances.

  13. High voltage pulse generator

    Science.gov (United States)

    Fasching, George E.

    1977-03-08

    An improved high-voltage pulse generator has been provided which is especially useful in ultrasonic testing of rock core samples. An N number of capacitors are charged in parallel to V volts and at the proper instance are coupled in series to produce a high-voltage pulse of N times V volts. Rapid switching of the capacitors from the paralleled charging configuration to the series discharging configuration is accomplished by using silicon-controlled rectifiers which are chain self-triggered following the initial triggering of a first one of the rectifiers connected between the first and second of the plurality of charging capacitors. A timing and triggering circuit is provided to properly synchronize triggering pulses to the first SCR at a time when the charging voltage is not being applied to the parallel-connected charging capacitors. Alternate circuits are provided for controlling the application of the charging voltage from a charging circuit to be applied to the parallel capacitors which provides a selection of at least two different intervals in which the charging voltage is turned "off" to allow the SCR's connecting the capacitors in series to turn "off" before recharging begins. The high-voltage pulse-generating circuit including the N capacitors and corresponding SCR's which connect the capacitors in series when triggered "on" further includes diodes and series-connected inductors between the parallel-connected charging capacitors which allow sufficiently fast charging of the capacitors for a high pulse repetition rate and yet allow considerable control of the decay time of the high-voltage pulses from the pulse-generating circuit.

  14. Application of FACTS devices to the 330 kV Nigerian system for voltage and power control

    Energy Technology Data Exchange (ETDEWEB)

    Komolafe, O.A. [Obafemi Awolowo Univ., Ile-Ife (Nigeria). Dept. of Electronic and Electrical Engineering; Adepoju, G. [Ladoke Akintola Univ. of Technology, Ogbomoso (Nigeria). Dept. of Electronic and Electrical Engineering; Garcia-Valle, R. [Technical Univ. of Denmark, Lyngby (Denmark). CET-Elektro

    2008-07-01

    Various flexible AC transmission system (FACTS) devices were investigated in this study. A static VAR compensator (SVC), static synchronous compensator (STATCOM) and a unified power flow controller (UPFC) were simulated in order to determine their voltage regulation and power flow control ability for a 330 kV transmission system in Nigeria. The FACTS models were tested on standard power networks and then modelled with a Newton-Raphson algorithm as part of a power flow analysis. The study identified potential locations for the devices in the Nigerian transmission network. Four case studies were considered in order to determine optimal configurations for the devices within the network. The study showed that the SVC and STATCOM devices regulate voltage buses without violating susceptance or voltage limits. The UPFC can control active power flow through transmission lines connecting the northern region of the country to areas with a high demand for power supply. 10 refs., 7 tabs., 5 figs.

  15. Surface plasmon polaritons on soft-boundary graphene nanoribbons and their application as voltage controlled plasmonic switches and frequency demultiplexers

    CERN Document Server

    Forati, Ebrahim

    2013-01-01

    A graphene sheet gated with a ridged ground plane, creating a soft-boundary (SB) graphene nanoribbon, is considered. By adjusting the ridge parameters and bias voltage a channel can be created on the graphene which can guide TM surface plasmon polaritons (SPP). Two types of modes are found; fundemental and higher-order modes with no apparent cutoff frequency and with energy distributed over the created channel, and edge modes with energy concen-trated at the soft-boundary edge. Dispersion curves, electric near-field patterns, and current distributions of these modes are determined. Since the location where energy is concentrated in the edge modes can be easily controlled electronically by the bias voltage and frequency, the edge-mode phenomena is used to propose a novel voltage controlled plasmonic switch and a plasmonic frequency demultiplexer.

  16. High-Efficiency Isolated Boost DCDC Converter for High-Power Low-Voltage Fuel-Cell Applications

    DEFF Research Database (Denmark)

    Nymand, Morten; Andersen, Michael A. E.

    2010-01-01

    A new design approach achieving very high conversion efficiency in low-voltage high-power isolated boost dc-dc converters is presented. The transformer eddy-current and proximity effects are analyzed, demonstrating that an extensive interleaving of primary and secondary windings is needed to avoid...... high winding losses. The analysis of transformer leakage inductance reveals that extremely low leakage inductance can be achieved, allowing stored energy to be dissipated. Power MOSFETs fully rated for repetitive avalanches allow primary-side voltage clamp circuits to be eliminated. The oversizing...

  17. 77 FR 21551 - New York City Department of Environmental Protection; Notice of Application Accepted for filing...

    Science.gov (United States)

    2012-04-10

    ... Energy Regulatory Commission New York City Department of Environmental Protection; Notice of Application.... Applicant: New York City Department of Environmental Protection. e. Name of Project: Cannonsville..., New York City Department of Environmental Protection, 59-17 Junction Blvd., Flushing, NY 11373-5108...

  18. 10 CFR 60.24 - Updating of application and environmental impact statement.

    Science.gov (United States)

    2010-01-01

    ... 10 Energy 2 2010-01-01 2010-01-01 false Updating of application and environmental impact statement... environmental impact statement. (a) The application shall be as complete as possible in the light of information... was issued. (c) The DOE shall supplement its environmental impact statement in a timely manner so as...

  19. Thermal and Environmental Barrier Coatings for Advanced Turbine Engine Applications

    Science.gov (United States)

    Zhu, Dong-Ming; Miller, Robert A.

    2005-01-01

    Ceramic thermal and environmental barrier coatings (T/EBCs) will play a crucial role in advanced gas turbine engine systems because of their ability to significantly increase engine operating temperatures and reduce cooling requirements, thus help achieve engine low emission and high efficiency goals. Advanced T/EBCs are being developed for the low emission SiC/SiC ceramic matrix composite (CMC) combustor applications by extending the CMC liner and vane temperature capability to 1650 C (3000 F) in oxidizing and water vapor containing combustion environments. Low conductivity thermal barrier coatings (TBCs) are also being developed for metallic turbine airfoil and combustor applications, providing the component temperature capability up to 1650 C (3000 F). In this paper, ceramic coating development considerations and requirements for both the ceramic and metallic components will be described for engine high temperature and high-heat-flux applications. The underlying coating failure mechanisms and life prediction approaches will be discussed based on the simulated engine tests and fracture mechanics modeling results.

  20. A Semantic Sensor Web for Environmental Decision Support Applications

    Science.gov (United States)

    Gray, Alasdair J. G.; Sadler, Jason; Kit, Oles; Kyzirakos, Kostis; Karpathiotakis, Manos; Calbimonte, Jean-Paul; Page, Kevin; García-Castro, Raúl; Frazer, Alex; Galpin, Ixent; Fernandes, Alvaro A. A.; Paton, Norman W.; Corcho, Oscar; Koubarakis, Manolis; De Roure, David; Martinez, Kirk; Gómez-Pérez, Asunción

    2011-01-01

    Sensing devices are increasingly being deployed to monitor the physical world around us. One class of application for which sensor data is pertinent is environmental decision support systems, e.g., flood emergency response. For these applications, the sensor readings need to be put in context by integrating them with other sources of data about the surrounding environment. Traditional systems for predicting and detecting floods rely on methods that need significant human resources. In this paper we describe a semantic sensor web architecture for integrating multiple heterogeneous datasets, including live and historic sensor data, databases, and map layers. The architecture provides mechanisms for discovering datasets, defining integrated views over them, continuously receiving data in real-time, and visualising on screen and interacting with the data. Our approach makes extensive use of web service standards for querying and accessing data, and semantic technologies to discover and integrate datasets. We demonstrate the use of our semantic sensor web architecture in the context of a flood response planning web application that uses data from sensor networks monitoring the sea-state around the coast of England. PMID:22164110

  1. Radiocarbon application in environmental science and archaeology in Croatia

    Energy Technology Data Exchange (ETDEWEB)

    Krajcar Bronic, I., E-mail: krajcar@irb.h [Radiocarbon Laboratory, Department of Experimental Physics, Ruder Boskovic Institute, Bijenicka 54, 10000 Zagreb (Croatia); Obelic, B.; Horvatincic, N.; Baresic, J.; Sironic, A. [Radiocarbon Laboratory, Department of Experimental Physics, Ruder Boskovic Institute, Bijenicka 54, 10000 Zagreb (Croatia); Minichreiter, K. [Institute of Archaeology, Ulica grada Vukovara 68, 10000 Zagreb (Croatia)

    2010-07-21

    Radiocarbon is a cosmogenic radioisotope equally distributed throughout the troposphere and biosphere. This fact enables its most common application-radiocarbon dating. Natural equilibrium of radiocarbon has been disturbed by diverse anthropogenic activities during the last {approx}150 years, enabling also the use of {sup 14}C in various environmental applications. Here we present three types of studies by using {sup 14}C that were performed in the Zagreb Radiocarbon Laboratory. {sup 14}C in atmospheric CO{sub 2} has been monitored at several sites with various anthropogenic influences and the difference between the clean-air sites, the industrial city and the vicinity of a nuclear power plant has been established. {sup 14}C has been applied in geochronology of karst areas, especially in dating of tufa, speleothems and lake sediments, as well as in studies of geochemical carbon cycle. {sup 14}C has been used in various archaeological studies, among which the dating of the early Neolithic settlements in Croatia is presented. In these studies {sup 14}C was measured by radiometric techniques, i.e., by gas proportional counting and more recently by liquid scintillation counting (LSC). Two sample preparation techniques for LSC measurement were used: benzene synthesis for archaeological dating and other applications that require better precision, and direct absorption of CO{sub 2} for monitoring purposes. The presented results show that various studies by using {sup 14}C can be successfully performed by the LSC technique, providing a large enough sample (>1 g of carbon).

  2. Alternating current breakdown voltage of ice electret

    Science.gov (United States)

    Oshika, Y.; Tsuchiya, Y.; Okumura, T.; Muramoto, Y.

    2017-09-01

    Ice has low environmental impact. Our research objectives are to study the availability of ice as a dielectric insulating material at cryogenic temperatures. We focus on ferroelectric ice (iceXI) at cryogenic temperatures. The properties of iceXI, including its formation, are not clear. We attempted to obtain the polarized ice that was similar to iceXI under the applied voltage and cooling to 77 K. The polarized ice have a wide range of engineering applications as electronic materials at cryogenic temperatures. This polarized ice is called ice electret. The structural difference between ice electret and normal ice is only the positions of protons. The effects of the proton arrangement on the breakdown voltage of ice electret were shown because electrical properties are influenced by the structure of ice. We observed an alternating current (ac) breakdown voltage of ice electret and normal ice at 77 K. The mean and minimum ac breakdown voltage values of ice electret were higher than those of normal ice. We considered that the electrically weak part of the normal ice was improved by applied a direct electric field.

  3. Enhanced Dynamic Voltage Stability Support by VSC-HVDC for Offshore Wind Applications using Trajectory Sensitivity Analysis

    DEFF Research Database (Denmark)

    Liu, Hongzhi; Chen, Zhe; Liu, Leo

    2013-01-01

    . In this paper, VSC-HVDC transmission system is used to integrate a large-scale wind power plant into the onshore power grid. For different voltage support strategies of VSC-HVDC, a trajectory sensitivity analysisbased approach is proposed to find the minimum onshore VSC capacity with which the VSC-HVDC can...

  4. Electronic noses and their applications in environmental monitoring

    Energy Technology Data Exchange (ETDEWEB)

    Hashem, S.; Keller, P.E.; Kouzes, R.T.; Kangas, L.J. [Pacific Northwest Lab., Richland, WA (United States)

    1995-12-31

    Compact, portable systems capable of quickly identifying contaminants in the field are of great importance when monitoring the environment. In this paper, we examine the effectiveness of using artificial neural networks for real-time data analysis of a sensor array. Analyzing the sensor data in parallel may allow for rapid identification of contaminants in the field without requiring highly selective component sensors. A sensor array combined with a data analysis module is referred to as an electronic nose. In this paper, we investigate the trade off between sensor sensitivity and selectivity relating to the applications of neural network based-electronic noses in environmental monitoring. We use a prototype electronic nose which consists of nine tin-oxide Taguchi-type sensors, a temperature sensor, and a humidity sensor. We illustrate that by using neural network based analysis of a sensor data, the selectivity of a sensor array may be significantly improved, especially when some (or all) sensors are not highly selective.

  5. Application of Proteomics and Lipid Studies in Environmental Biotechnology

    Energy Technology Data Exchange (ETDEWEB)

    Mukhopadhyay, Aindrila

    2008-08-12

    The overview of changes in protein levels or states in response to a growth condition, stress, mutation or metabolic engineering is invaluable in understanding the physiology of a microbial system. The lipid profile of the cell is similarly a valuable diagnostic of the cellular response and health, especially in context of survival in a fluctuating environment. To obtain comprehensive cellular models, post-transcriptional cell wide surveys at the levels of proteins and lipids are required. Both these fields have been greatly bolstered by the development of high throughput methods using mass spectrometry. Multiple strategies now exist for the identification of proteins, and numerous workflows to quantify protein abundance have also been developed. Cellular profiling such as these allows us to assess the potential of a microbial system for environmental applications such as bioremediation and bio-energy.

  6. Modular High Voltage Power Supply

    Energy Technology Data Exchange (ETDEWEB)

    Newell, Matthew R. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2017-05-18

    The goal of this project is to develop a modular high voltage power supply that will meet the needs of safeguards applications and provide a modular plug and play supply for use with standard electronic racks.

  7. Environmental indicators for communication of life cycle impact assessment results and their applications.

    Science.gov (United States)

    Lim, Seong-Rin; Park, Jong Moon

    2009-08-01

    Life cycle impact assessment (LCIA) is performed to quantitatively evaluate all environmental impacts from products, systems, processes and services. However, LCIA does not always provide valuable information for choosing among alternatives with different specifications, functionalities and lifetimes. The objectives of this study are (1) to propose environmental indicators to evaluate environmental efficiency and value qualitatively and quantitatively on the basis of analogies to financial and economic indicators, and (2) to present the application of the indicators. Incremental evaluation using a reference is employed to obtain the environmental indicators. The environmental efficiency indicators are conceptually based on the ratios of reduced environmental burdens returned to environmental burdens required: environmental return on investment, environmental payback period and environmental internal rate of return. The environmental value indicator is the sum of all reduced and required environmental burdens: i.e., environmental net present value. All the environmental indicators can be used to compare and rank the environmental efficiencies or values of alternatives. The environmental efficiency indicators can be applied to a new environmental labeling. The concept of eco-efficiency labeling is developed by combining the environmental efficiency indicators with financial indicators. A case study is performed to illustrate the necessity and importance of the environmental indicators. These environmental indicators can help easily communicate LCIA results in the field of environmental management.

  8. Six-step Voltage Control of PM Brushless AC Motors under High Speed Flux-weakening Operation for EV/HEV Applications

    Institute of Scientific and Technical Information of China (English)

    诸自强

    2008-01-01

    The torque-speed characteristics of brushless motor having an interior permanent magnet rotor and a sinusoidalback-emf waveform are compared experimentally when it is operated in brushless AC (BLAC) mode and brushless DC(BLDC) modes with both 2-phase, 120° conduction (BLDC-120) and 3-phase,180° conduction (BLDC-180).Particularemphasis is on high-speed,six-step voltage controlled,flux-weakening operation.h is shown that for EV/HEV applications,even for interior PM brushless motors which have sinusoidal back-emf waveforms,in order to achieve maximum torque perampere capability over wide operation speed range,it is advantageous to employ a hybrid operation mode-BLAC operationin the constant torque region and six-step voltage control (BLDC-180 operation, together with current phase control) inthe flux-weakening region.

  9. Environmentally dependent bond-order potentials: New developments and applications

    Indian Academy of Sciences (India)

    D Nguyen-Manh; D G Pettifor; D J H Cockayne; M Mrovec; S Znam; V Vitek

    2003-01-01

    The bond-order potentials (BOPs) idea employs the orthogonal two-centre tight-binding (TB) representation for the bond energy and the Harris–Foulkes approximation for the repulsive pairwise contribution. In the last ten years, although many efforts have been focused on theoretical calculations of the bond order expression, the BOPs still suffers from the uncertainty of how best to choose the semi-empirical TB parameters that enter the scheme. In this paper, we review recent developments to obtain the reliable and transferable BOPs which help to extend the accuracy and applicability to technologically important multicomponent systems. Firstly, we have found that a simple pair potential is unsuitable for describing the environmental screening effects due to the and orbital overlap repulsion in transition metal alloys and therefore the inability to reproduce the negative Cauchy pressures exhibiting in strong covalent systems. By adding the environmental dependent repulsive term, the Cauchy pressure problem has been removed and we are now able to get the BOPs for studying dislocations, extended defects and mechanical properties of hightemperature intermetallic Ti–Al alloys. In particular, new results on the core structures and possible dissociation of different type of dislocations will be discussed. Secondly, we present the first derivation of explicit analytic expressions for environmental dependence of , and bond integrals by inverting the non-orthogonal matrix. We illustrate the power of this new formalism by showing that it not only captures the transferability of bond integrals between Mo, Si and MoSi2 but also predicts the large discontinuities between first and second nearest neighbours for $pp\\sigma, pp\\pi$ and $dd\\pi$ even though absence of any discontinuity for the $dd\\sigma$ bond integral. A new environmentally dependent BOPs has been developed for bcc-Mo indicating that the core structure of 1/2$\\langle$111$\\rangle$ screw dislocations is

  10. Geographic information system(GIS) applications to optimize route selection, environmental analysis and power transmission line designs; Aplicaciones en sistemas de informacion geograficos (SIG) para optimizar seleccion de ruta, analisis ambiental y diseno de lineas de transmision

    Energy Technology Data Exchange (ETDEWEB)

    Cadena Suarez, Luis Fernando; Posada Delgado, Fabio Humberto; Alvarez Davila, Esteban; Gomez Colorado, Oscar Alberto [Interconexion Electrica S.A. (ISA), Medellin (Colombia)]. E-mail: fecadena@isa.com.co

    2001-07-01

    Interconexion Eletrica s.a. (ISA) is a company of the Colombian government for electric energy transportation through the national energy transportation network, it makes part of the companies group with growing environmental conscience. The better route identifications for high voltage transmission lines do not involve just the engineering analyses, but mainly the environmental one.These integrated analysis have been largely powered through the technology applications like Geographic Information Systems (GIS) and Remote Sensing (RS). These technologies were applied for a total of 300 kilometers between 1992 and 2000 in the largest power transmission lines whose configurations cross different geographic conditions. This current technical contribution describes the application of GIS and RS technologies for the best routes, environmental sensibility analysis and environmental impact evaluations. The applications have resulted in the integration between engineering and environmental processes, optimization of environmental evaluation, formulations of procedures handling and environmental control, as well as transmission line profile characteristics. After the project construction, GIS can be used as a useful tool for environmental monitoring in connection with power transmission lines, maintenance of servitude areas, availability conditions and quality of the high voltage transmission service.

  11. Iron: a versatile element to produce materials for environmental applications

    Energy Technology Data Exchange (ETDEWEB)

    Teixeira, Ana Paula C.; Araujo, Maria H.; Oliveira, Luiz C.A.; Moura, Flavia C.C.; Lago, Rochel M., E-mail: rochel@ufmg.br, E-mail: anapct@ufmg.br [Departamento de Quimica, Universidade Federal de Minas Gerais, Belo Horizonte, MG (Brazil); Tristao, Juliana C. [Universidade Federal de Vicosa, Florestal, MG (Brazil); Ardisson, Jose D. [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil). Lab. de Fisica Aplicada; Amorim, Camila C., E-mail: juliana@ufv.br [Departamento de Engenharia Sanitaria e Ambiental, Universidade Federal de Minas Gerais, Belo Horizonte, MG (Brazil)

    2012-09-15

    Iron is a versatile element forming several phases with different oxidation states and {sup s}tructures, such as Fe{sup 0}, FeO, Fe{sub 3}O{sub 4}, {gamma}-Fe{sub 2}O{sub 3}, {alpha}-Fe{sub 2}O{sub 3} and FeOOH. All these phases have unique physicochemical properties which can be used for different applications. In this work, it is described the use of different iron compounds, synthetic and also from natural and waste sources, in environmental and technological applications. Two main research areas are described. The first one is related to strategies to increase the reactivity of Fe phases, mainly by the formation of Fe{sup 0}/iron oxide composites and by the introduction of new metals in the iron oxide structure to promote new surface reactions. The second area is the use of the magnetic properties of some iron phases to produce versatile magnetic materials with focus in adsorption, catalysis and emulsions. (author)

  12. Anthropocentric and Ecocentric: An Application of Environmental Philosophy to Outdoor Recreation and Environmental Education

    Science.gov (United States)

    Cocks, Samuel; Simpson, Steven

    2015-01-01

    Sometimes environmental philosophers write only for other environmental philosophers, and their insights on the nature-human relationship do not reach environmental educators and adventure programmers. This article investigates one aspect of environmental philosophy and the differences between anthropocentric and ecocentric thinking, and applies…

  13. Anthropocentric and Ecocentric: An Application of Environmental Philosophy to Outdoor Recreation and Environmental Education

    Science.gov (United States)

    Cocks, Samuel; Simpson, Steven

    2015-01-01

    Sometimes environmental philosophers write only for other environmental philosophers, and their insights on the nature-human relationship do not reach environmental educators and adventure programmers. This article investigates one aspect of environmental philosophy and the differences between anthropocentric and ecocentric thinking, and applies…

  14. Accurate Switched-Voltage voltage averaging circuit

    OpenAIRE

    金光, 一幸; 松本, 寛樹

    2006-01-01

    Abstract ###This paper proposes an accurate Switched-Voltage (SV) voltage averaging circuit. It is presented ###to compensated for NMOS missmatch error at MOS differential type voltage averaging circuit. ###The proposed circuit consists of a voltage averaging and a SV sample/hold (S/H) circuit. It can ###operate using nonoverlapping three phase clocks. Performance of this circuit is verified by PSpice ###simulations.

  15. Inverse-magnetostriction-induced switching current reduction of STT-MTJs and its application for low-voltage MRAM

    Science.gov (United States)

    Takamura, Yota; Shuto, Yusuke; Yamamoto, Shu'uichiro; Funakubo, Hiroshi; Kurosawa, Minoru Kuribayashi; Nakagawa, Shigeki; Sugahara, Satoshi

    2017-02-01

    A new spin-transfer torque (STT) magnetic tunnel junction (MTJ) using an inverse magnetostriction (IMS) material for the free layer is proposed for low-voltage MRAMs. The MTJ is surrounded by a piezoelectric gate structure so that a pressure for introducing the IMS effect can efficiently be applied to the free layer without any high-yield-strength support structure. During STT-induced magnetization switching, the energy barrier height for the switching can be lowered by the IMS effect, and thus a critical current density (JC) for the magnetization switching can dramatically be reduced. Energy performance of a low-voltage STT-MRAM cell using the proposed MTJ and a FinFET is also demonstrated.

  16. High voltage generation from lead-free magnetoelectric coaxial nanotube arrays and their applications in nano energy harvesters

    Science.gov (United States)

    Lekha, C. S. Chitra; Kumar, Ajith S.; Vivek, S.; Rasi, U. P. Mohammed; Venkata Saravanan, K.; Nandakumar, K.; Nair, Swapna S.

    2017-02-01

    Harvesting energy from surrounding vibrations and developing self-powered portable devices for wireless and mobile electronics have recently become popular. Here the authors demonstrate the synthesis of piezoelectric energy harvesters based on nanotube arrays by a wet chemical route, which requires no sophisticated instruments. The energy harvester gives an output voltage of 400 mV. Harvesting energy from a sinusoidal magnetic field is another interesting phenomenon for which the authors fabricated a magnetoelectric energy harvester based on piezoelectric-magnetostrictive coaxial nanotube arrays. Piezoelectric K0.5Na0.5NbO3 (KNN) is fabricated as the shell and magnetostrictive CoFe2O4 (CFO) as the core of the composite coaxial nanotubes. The delivered voltages are as high as 300 mV at 500 Hz and at a weak ac magnetic field of 100 Oe. Further tailoring of the thickness of the piezoelectric and magnetic layers can enhance the output voltage by several orders. Easy, single-step wet chemical synthesis enhances the industrial upscaling potential of these nanotubes as energy harvesters. In view of the excellent properties reported here, the lead-free piezoelectric component (KNN) in this nanocomposite should be explored for eco-friendly piezoelectric as well as magnetoelectric power generators in nanoelectromechanical systems (NEMS).

  17. An Integrated Wireless Power Management and Data Telemetry IC for High-Compliance-Voltage Electrical Stimulation Applications.

    Science.gov (United States)

    Zhao, Jianming; Yao, Lei; Xue, Rui-Feng; Li, Peng; Je, Minkyu; Xu, Yong Ping

    2016-02-01

    This paper describes a 13.56-MHz wireless power recovery system with bidirectional data link for high-compliance-voltage neural/muscle stimulator. The power recovery circuit includes a 2-stage rectifier, 2 LDOs and a high voltage charge pump to provide 3 DC outputs: 1.8 V, 3.3 V and 20 V for the stimulator. A 2-stage time division based rectifier is proposed to provide 3 DC outputs simultaneously. It improves the power efficiency without introducing any impact on the forward data recovery. The 20 V output is generated by a modified low ripple charge pump that reduces the ripple voltage by 40%. The power management system shows 49% peak power efficiency. The data link includes a clock and data recovery (CDR) circuit and a load shift keying (LSK) modulator for bidirectional data telemetry. The forward and backward data rates of the data telemetry are 61.5 kbps and 33.3 kbps, respectively. In addition, a power monitor circuit for closed-loop power control is implemented. The whole system has been fabricated in a 24 V HV LDMOS option 1.8 μ m CMOS process, occupying a core area of around 3.5 mm (2).

  18. Application of biosurfactants and periodic voltage gradient for enhanced electrokinetic remediation of metals and PAHs in dredged marine sediments.

    Science.gov (United States)

    Ammami, M T; Portet-Koltalo, F; Benamar, A; Duclairoir-Poc, C; Wang, H; Le Derf, F

    2015-04-01

    Dredged harbor sediment co-contaminated by heavy metals and polycyclic aromatic hydrocarbons (PAHs) was subjected to enhanced electrokinetic treatments, using a mixture of a chelating agent (citric acid CA) and a surfactant as additives in the processing fluids. We tested various operating conditions (at 1 V cm(-1)): different CA concentrations, applying a periodic voltage gradient, pre-conditioning the sediment with the additives, and replacing the synthetic surfactant Tween 20 (TW20) by biosurfactants. Increasing the CA concentration was favorable for both metal and PAH removal. Applying a periodic voltage gradient associated to a low concentration of CA and TW20 provided the best results for Zn, Cd and Pb removal and also for removal of the 16 priority PAHs. Promising results were obtained with solutions containing rhamnolipids (0.028%) and a viscosin-like biosurfactant produced by Pseudomonas fluorescens Pfa7B (0.025%), associated to a periodic voltage gradient. Although the rhamnolipid and the viscosin-like compounds involved a higher electrical current than TW20, metals were less removed from the sediment. The electroosmotic flow was lower when we used biosurfactants, hence a less effective effect on PAH removal.

  19. Influence of gradual cobalt substitution on lithium nickel phosphate nano-scale composites for high voltage applications

    Energy Technology Data Exchange (ETDEWEB)

    Örnek, Ahmet, E-mail: ahmetornek0302@hotmail.com [Kafkas University, Atatürk Vocational School of Healthcare, 36100 Kars (Turkey); Bulut, Emrah [Sakarya University, Department of Chemistry, 54187 Sakarya (Turkey); Can, Mustafa [Sakarya University, Arifiye Vocational School, 54580 Sakarya (Turkey)

    2015-08-15

    The carbon-free LiNiPO{sub 4} and cobalt doped LiNi{sub 1−x}Co{sub x}PO{sub 4}/C (x = 0.0–1.0) were synthesized and investigated for high voltage applications (> 4 V) for Li-ion batteries. Nano-scale composites were prepared by handy sol–gel approach using citric acid under slightly reductive gas atmosphere (Ar-H{sub 2}, 85:15%). Structural and morphological characteristics of the powders were revealed by X-ray powder diffraction (XRD), field-emission scanning electron microscopy (FE-SEM), high resolution transmission electron microscopy (HR-TEM) and inductively coupled plasma (ICP). Except for a small impurity phase (Ni{sub 3}P), phase pure samples crystallized in the olivine-lattice structure with a linear relationship between lattice parameters (a, b and c) and chemical composition. The FE-SEM images proved that LiNiPO{sub 4}/C particles (50–80 nm) did not agglomerate, and showed that as the cobalt content was higher agglomeration had increased. The electrochemical properties of all electrodes were investigated by galvanostatic charge–discharge measurements. Substitution of Ni{sup 2} {sup +} by Co{sup 2} {sup +} caused higher electronic conductivities and showed more effective Li{sup +} ion mobility. When the cobalt content is 100%, the capacity reached to a higher level (146.2 mA h g{sup −} {sup 1}) and good capacity retention of 85.1% at the end of the 60 cycles was observed. The cycling voltammogram (CV) revealed that LiCoPO{sub 4}/C electrode improved the electrochemical properties. The Ni{sup 3} {sup +}–Ni{sup 2} {sup +} redox couple was not observed for carbon free LiNiPO{sub 4}. Nevertheless, it was observed that carbon coated LiNiPO{sub 4} sample exhibits a significant oxidation (5.26 V)–reduction (5.08 V) peaks. With this study, characteristics of the LiNi{sub 1−x}Co{sub x}PO{sub 4}/C series were deeply evaluated and discussed. - Highlights: • Structural, morphological and electrochemical effects of Co doped LiNi{sub 1−} {sub x

  20. Application of Voltage Response Method to Condition Assessment of Power Transformer%电压响应方法在电力变压器状态评估中的应用

    Institute of Scientific and Technical Information of China (English)

    张涛; 蔡金锭; 张孔林

    2008-01-01

    Power transformer is one of the most important equipment in the power system. Its operating condition affects the reliability of power supply directly. Therefore, in order to guarantee transformer operation safely and reliably, it is necessary to assess condition of power transformer accurately. Return voltage method based on voltage response measurements is still a new non-intrusive diagnosis method for internal insulation aging of transformer. In this paper the technique and application of return voltage measurement and some results of voltage response measurements of several transformers was introduced. Voltage response measurements were performed on various transformers with different voltage grades, various operating periods, different moisture contents and aging degrees on site. Derived moisture contents from return voltage measurement were compared with the corresponding moisture contents obtained from the analysis of oil samples. Based on on-site experiments and theoretical analysis, the criteria for insulation state of transformer are proposed. Moisture condition of transformer insulation can be determined by using return dominant time constant, and a good correlation between aging degree and the return voltage initial slopes of the aged transformers. Field test performed on several transformers, its interpretation of results are also presented, which proves that return voltage measurements can be used as a reliable tool for evaluating moisture content in transformer insulation.

  1. 低压载波通讯测试仪的开发与应用%The Development and Application of the Low Voltage Carrier Wave Communication Tester

    Institute of Scientific and Technical Information of China (English)

    刘勇; 张明旭; 李贤伟; 李丹

    2014-01-01

    文章从原来集抄系统缺乏有效的现场调试方式和试验方法来分析原问题的所在,从原理上详细论述了低压载波通讯测试仪在低压集抄采集系统维护中的应用,这对我们的低压采集系统今后的维护工作十分重要。这项技术的推广可以使我们的集抄系统建设工作更加方便、快捷,使之能更好地为营销现代化工作服务。%In view of the problem that there is no effective field debugging method or testing method in the original e -lectricity data collection system, the paper detailedly and theoretically discussed the application of the low voltage car -rier wave communication tester to the maintenance of the low voltage data collection system .This will be of vital im-portance for the maintenance of the low voltage data collection system in the future .The promotion of the technology can make the construction of the data collection system more convenient and faster , and enable it to provide better service for the modernization of marketing.

  2. Extracellular polymeric substances of bacteria and their potential environmental applications.

    Science.gov (United States)

    More, T T; Yadav, J S S; Yan, S; Tyagi, R D; Surampalli, R Y

    2014-11-01

    Biopolymers are considered a potential alternative to conventional chemical polymers because of their ease of biodegradability, high efficiency, non-toxicity and non-secondary pollution. Recently, extracellular polymeric substances (EPS, biopolymers produced by the microorganisms) have been recognised by many researchers as a potential flocculent for their applications in various water, wastewater and sludge treatment processes. In this context, literature information on EPS is widely dispersed and is very scarce. Thus, this review marginalizes various studies conducted so far about EPS nature-production-recovery, properties, environmental applications and moreover, critically examines future research needs and advanced application prospective of the EPS. One of the most important aspect of chemical composition and structural details of different moieties of EPS in terms of carbohydrates, proteins, extracellular DNA, lipid and surfactants and humic substances are described. These chemical characteristics of EPS in relation to formation and properties of microbial aggregates as well as degradation of EPS in the matrix (biomass, flocs etc) are analyzed. The important engineering properties (based on structural characteristics) such as adsorption, biodegradability, hydrophilicity/hydrophobicity of EPS matrix are also discussed in details. Different aspects of EPS production process such as bacterial strain maintenance; inoculum and factors affecting EPS production were presented. The important factors affecting EPS production include growth phase, carbon and nitrogen sources and their ratio, role of other nutrients (phosphorus, micronutrients/trace elements, and vitamins), impact of pH, temperature, metals, aerobic versus anaerobic conditions and pure and mixed culture. The production of EPS in high concentration with high productivity is essential due to economic reasons. Therefore, the knowledge about all the aspects of EPS production (listed above) is highly

  3. Switching performance and efficiency investigation of GaN based DC-DC Buck converter for low voltage and high current applications

    Science.gov (United States)

    Alatawi, Khaled; Almasoudi, Fahad; Matin, Mohammad

    2016-09-01

    The Wide band-gap (WBG) materials "such as Silicon Carbide (SiC) and Gallium nitride (GaN)" based power switching devices provide higher performance capabilities compared to Si-based power switching devices. The wide band-gap materials based power switching devices outperform Si-based devices in many performance characteristics such as: low witching loss, low conduction loss, high switching frequencies, and high operation temperature. GaN based switching devices benefit a lot of applications such as: future electric vehicles and solar power inverters. In this paper, a DC-DC Buck converter based on GaN FET for low voltage and high current applications is designed and investigated. The converter is designed for stepping down a voltage of 48V to 12V with high switching frequency. The capability of the GaN FET based buck converter is studied and compared to equivalent SiC MOSFET and Si-based MOSFET buck converters. The analysis of switching losses and efficiency was performed to compare the performance capabilities of GaN FET, SiC MOSFET and Si-based MOSFET. The results showed that the overall switching losses of GaN FET are lower than that of SiC and Si-based power switching devices. Also, the performance capability of GaN devices with higher frequencies is studied. GaN devices with high frequencies will reduce the total size and the cost of the power converter. In Addition, the overall efficiency of the DC-DC Buck converter is higher with the GaN FET switching devices, which make it more suitable for low voltage and high current applications.

  4. Advanced Carbon Materials for Environmental and Energy Applications

    KAUST Repository

    Dua, Rubal

    2014-05-01

    Carbon based materials, including porous carbons and carbon layer composites, are finding increased usage in latest environmental and energy related research. Among porous carbon materials, hierarchical porous carbons with multi-modal porosity are proving out to be an effective solution for applications where the traditional activated carbons fail. Thus, there has been a lot of recent interest in developing low-cost, facile, easy to scale-up, synthesis techniques for producing such multi-modal porous carbons. This dissertation offers two novel synthesis techniques: (i) ice templating integrated with hard templating, and (ii) salt templating coupled with hard templating, for producing such hierarchically porous carbons. The techniques offer tight control and tunability of porosity (macro- meso- and microscale) in terms of both size and extent. The synthesized multi-modal porous carbons are shown to be an effective solution for three important environment related applications – (i) Carbon dioxide capture using amine supported hierarchical porous carbons, (ii) Reduction in irreversible fouling of membranes used for wastewater reuse through a deposition of a layer of hierarchical porous carbons on the membrane surface, (iii) Electrode materials for electrosorptive applications. Finally, because of their tunability, the synthesized multi-modal porous carbons serve as excellent model systems for understanding the effect of different types of porosity on the performance of porous carbons for these applications. Also, recently, there has been a lot of interest in developing protective layer coatings for preventing photo-corrosion of semiconductor structures (in particular Cu2O) used for photoelectrochemical water splitting. Most of the developed protective strategies to date involve the use of metals or co-catalyst in the protective layer. Thus there is a big need for developing low-cost, facile and easy to scale protective coating strategies. Based on the expertise

  5. Piezo Voltage Controlled Planar Hall Effect Devices

    OpenAIRE

    Bao Zhang; Kang-Kang Meng; Mei-Yin Yang; Edmonds, K. W.; Hao Zhang; Kai-Ming Cai; Yu Sheng; Nan Zhang; Yang Ji; Jian-Hua Zhao; Hou-Zhi Zheng; Kai-You Wang

    2015-01-01

    The electrical control of the magnetization switching in ferromagnets is highly desired for future spintronic applications. Here we report on hybrid piezoelectric (PZT)/ferromagnetic (Co2FeAl) devices in which the planar Hall voltage in the ferromagnetic layer is tuned solely by piezo voltages. The change of planar Hall voltage is associated with magnetization switching through 90° in the plane under piezo voltages. Room temperature magnetic NOT and NOR gates are demonstrated based on the pie...

  6. Defining criteria for good environmental journalism and testing their applicability: An environmental news review as a first step to more evidence based environmental science reporting.

    Science.gov (United States)

    Rögener, Wiebke; Wormer, Holger

    2017-05-01

    While the quality of environmental science journalism has been the subject of much debate, a widely accepted benchmark to assess the quality of coverage of environmental topics is missing so far. Therefore, we have developed a set of defined criteria of environmental reporting. This instrument and its applicability are tested in a newly established monitoring project for the assessment of pieces on environmental issues, which refer to scientific sources and therefore can be regarded as a special field of science journalism. The quality is assessed in a kind of journalistic peer review. We describe the systematic development of criteria, which might also be a model procedure for other fields of science reporting. Furthermore, we present results from the monitoring of 50 environmental reports in German media. According to these preliminary data, the lack of context and the deficient elucidation of the evidence pose major problems in environmental reporting.

  7. High voltage surface potential measurements in ambient conditions: Application to organic thin-film transistor injection and transport characterization

    Science.gov (United States)

    de Tournadre, Grégoire; Reisdorffer, Frédéric; Rödel, Reinhold; Simonetti, Olivier; Klauk, Hagen; Giraudet, Louis

    2016-03-01

    A scanning surface potential measurement technique suited for thin-film devices operating under high voltages is reported. A commercial atomic force microscope has been customized to enable a feedback-controlled and secure surface potential measurement based on phase-shift detection under ambient conditions. Measurements of the local potential profile along the channel of bottom-gate organic thin-film transistors (TFTs) are shown to be useful to disentangle the contributions from the channel and contacts to the device performance. Intrinsic contact current-voltage characteristics have been measured on bottom-gate, top-contact (staggered) TFTs based on the small-molecule semiconductor dinaphtho[2,3-b:2',3-f]thieno[3,2-b]thiophene (DNTT) and on bottom-gate, bottom-contact (coplanar) TFTs based on the semiconducting polymer polytriarylamine (PTAA). Injection has been found to be linear in the staggered DNTT TFTs and nonlinear in the coplanar PTAA TFTs. In both types of TFT, the injection efficiency has been found to improve with increasing gate bias in the accumulation regime. Contact resistances as low as 130 Ω cm have been measured in the DNTT TFTs. A method that eliminates the influence of bias-stress-induced threshold-voltage shifts when measuring the local charge-carrier mobility in the channel is also introduced, and intrinsic channel mobilities of 1.5 cm2 V-1 s-1 and 1.1 × 10-3 cm2 V-1 s-1 have been determined for DNTT and PTAA. In both semiconductors, the mobility has been found to be constant with respect to the gate bias. Despite its simplicity, the Kelvin probe force microscopy method reported here provides robust and accurate surface potential measurements on thin-film devices under operation and thus paves the way towards more extensive studies of particular interest in emerging fields of solid-state electronics.

  8. Recent trends in nanomaterials applications in environmental monitoring and remediation.

    Science.gov (United States)

    Das, Sumistha; Sen, Biswarup; Debnath, Nitai

    2015-12-01

    Environmental pollution is one of the greatest problems that the world is facing today, and it is increasing with every passing year and causing grave and irreparable damage to the earth. Nanomaterials, because of their novel physical and chemical characteristics, have great promise to combat environment pollution. Nanotechnology is being used to devise pollution sensor. A variety of materials in their nano form like iron, titanium dioxide, silica, zinc oxide, carbon nanotube, dendrimers, polymers, etc. are increasingly being used to make the air clean, to purify water, and to decontaminate soil. Nanotechnology is also being used to make renewable energy cheaper and more efficient. The use of nanotechnology in agriculture sector will reduce the indiscriminate use of agrochemicals and thus will reduce the load of chemical pollutant. While remediating environment pollution with nanomaterials, it should also be monitored that these materials do not contribute further degradation of the environment. This review will focus broadly on the applications of nanotechnology in the sustainable development with particular emphasis on renewable energy, air-, water-, and soil-remediation. Besides, the review highlights the recent developments in various types of nanomaterials and nanodevices oriented toward pollution monitoring and remediation.

  9. Hybrid Magnetic Core-Shell Nanophotocatalysts for Environmental Applications

    Energy Technology Data Exchange (ETDEWEB)

    Gaulden, Patrick [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Murph, Simona Hunyadi [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Univ. of Georgia, Athens, GA (United States). Dept. of Physics and Astronomy

    2016-07-29

    This research study describes a facile sol-gel method to creating hybrid iron (III) oxide/silica/titania nanomaterials decorated with gold nanoparticles for use in environmental applications. The multi-functional composition of the nanomaterials allows for photocatalyzed reactions to occur in both the visible and the UV range. The morphologies, elemental composition, and surface charge of the nanoparticles were determined by Scanning Electron Microscopy (SEM), Energy Dispersive X-ray Spectroscopy (EDS), and Phase Analysis Light Scattering (PALS), respectively. The photocatalytic activity of the synthesized hybrid nanoparticles for breaking down a model analyte, methyl orange (MO), was then evaluated using UV-Vis Spectroscopy. The efficiency of the photocatalyst under UV light irradiation was measured and compared to other well-studied nanophotocatalysts, namely titanium oxide and iron oxide nanoparticles. The concentration dependence of both the photocatalyst and the analyte was also investigated. By utilizing the known UV-active properties of TiO2, the magnetic properties of Fe2O3, the optical properties of gold in the visible range of the spectrum, and the high stability of silica, a novel, highly efficient photocatalyst that is active on a broad range of the spectrum (UV-Vis) can be created to destroy organic pollutants in wastewater streams.

  10. 77 FR 16023 - New York City Department of Environmental Protection; Notice of Application Tendered for Filing...

    Science.gov (United States)

    2012-03-19

    ... Federal Energy Regulatory Commission New York City Department of Environmental Protection; Notice of...: February 29, 2012. d. Applicant: New York City Department of Environmental Protection. e. Name of Project...--Operations, New York City Department of Environmental Protection, 59-17 Junction Blvd., Flushing, NY 11373...

  11. The application of DEA model in enterprise environmental performance auditing

    Science.gov (United States)

    Li, F.; Zhu, L. Y.; Zhang, J. D.; Liu, C. Y.; Qu, Z. G.; Xiao, M. S.

    2017-01-01

    As a part of society, enterprises have an inescapable responsibility for environmental protection and governance. This article discusses the feasibility and necessity of enterprises environmental performance auditing and uses DEA model calculate the environmental performance of Haier for example. The most of reference data are selected and sorted from Haier’s environmental reportspublished in 2008, 2009, 2011 and 2015, and some of the data from some published articles and fieldwork. All the calculation results are calculated by DEAP software andhave a high credibility. The analysis results of this article can give corporate managements an idea about using environmental performance auditing to adjust their corporate environmental investments capital quota and change their company’s environmental strategies.

  12. Titania coated hollow glass microspheres for environmental applications

    Science.gov (United States)

    Koopman, Mark C.

    The potential applicability of titania coated hollow glass microspheres (HGMs) to the photocatalytic degradation of microbiological and organic chemical water pollutants could have dramatic positive effects on improving the quality of industrial wastewaters that empty into rivers and streams, as well as potential use in economically improving the quality of drinking water. Heterogeneous photocatalysis using titania has been extensively studied since the 1990's because of its non-toxic nature, its high quantum yield of electrons and photo-holes, and its ability to use ambient solar radiation as a power source. Although titania embodies extraordinarily attractive properties for a range of environmental applications, a viable substrate or method of using the material effectively has not been recognized. HGMs are particularly attractive as a support for titania because of their low density and high surface area to volume ratio, but details of how they react to imposed loading, wear, and impact have not been addressed, nor have materials engineering analyses that could maximize their utility been made. In this study we have examined the microstructure, morphology and micro-compression properties of two types of titania coated hollow microspheres, a commercially produced HGM and cenospheres, a derivative of fly ash. Comparisons of uncoated and titania coated hollow microspheres showed improved failure loads and facture energies for the titania coated materials over the uncoated hollow microspheres. Also, the relationship between failure load and hollow microsphere diameter was characterized and the function employed to explain part of the gain in average failure load for the HGMs. Microscopic examination of titania coated HGMs that were subjected to various turbulent conditions, as well as intentional fracture, indicated good interfacial integrity, which supports the viability of both types of HGMs for potential applications. The photocatalytic reactivity of the titania

  13. Multi-criteria decision analysis in environmental sciences: ten years of applications and trends.

    Science.gov (United States)

    Huang, Ivy B; Keisler, Jeffrey; Linkov, Igor

    2011-09-01

    Decision-making in environmental projects requires consideration of trade-offs between socio-political, environmental, and economic impacts and is often complicated by various stakeholder views. Multi-criteria decision analysis (MCDA) emerged as a formal methodology to face available technical information and stakeholder values to support decisions in many fields and can be especially valuable in environmental decision making. This study reviews environmental applications of MCDA. Over 300 papers published between 2000 and 2009 reporting MCDA applications in the environmental field were identified through a series of queries in the Web of Science database. The papers were classified by their environmental application area, decision or intervention type. In addition, the papers were also classified by the MCDA methods used in the analysis (analytic hierarchy process, multi-attribute utility theory, and outranking). The results suggest that there is a significant growth in environmental applications of MCDA over the last decade across all environmental application areas. Multiple MCDA tools have been successfully used for environmental applications. Even though the use of the specific methods and tools varies in different application areas and geographic regions, our review of a few papers where several methods were used in parallel with the same problem indicates that recommended course of action does not vary significantly with the method applied. Published by Elsevier B.V.

  14. Discharge Characteristics of DC Arc Water Plasma for Environmental Applications

    Institute of Scientific and Technical Information of China (English)

    LI Tianming; Sooseok CHOI; Takayuki WATANABE

    2012-01-01

    A water plasma was generated by DC arc discharge with a hafnium embedded rodtype cathode and a nozzle-type anode. The discharge characteristics were examined by changing the operation parameter of the arc current. The dynamic behavior of the arc discharge led to significant fluctuations in the arc voltage and its frequency. Analyses of the high speed image and the arc voltage waveform showed that the arc discharge was in the restrike mode and its frequency varied within several tens of kilohertz according to the operating conditions. The larger thermal plasma volume was generated by the higher flow from the forming steam with a higher restrike frequency in the higher arc current conditions. In addition, the characteristics of the water plasma jet were investigated by means of optical emission spectroscopy to identify the abundant radicals required in an efficient waste treatment process.

  15. Application of voltage oriented control technique in a fully renewable, wind powered, autonomous system with storage capabilities

    Science.gov (United States)

    Kondylis, Georgios P.; Vokas, Georgios A.; Anastasiadis, Anestis G.; Konstantinopoulos, Stavros A.

    2017-02-01

    The main purpose of this paper is to examine the technological feasibility of a small autonomous network, with electricity storage capability, which is completely electrified by wind energy. The excess energy produced, with respect to the load requirements, is sent to the batteries for storage. When the energy produced by the wind generator is not sufficient, load's energy requirement is covered by the battery system, ensuring, however, that voltage, frequency and other system characteristics are within the proper boundaries. For the purpose of this study, a Voltage Oriented Control system has been developed in order to monitor the autonomous operation and perform the energy management of the network. This system manages the power flows between the load and the storage system by properly controlling the Pulse Width Modulation pulses in the converter, thus ensuring power flows are adequate and frequency remains under control. The experimental results clearly indicate that a stand-alone wind energy system based on battery energy storage system is feasible and reliable. This paves the way for fully renewable and zero emission energy schemes.

  16. 2003 Wastewater Land Application Site Performance Reports for the Idaho National Engineering and Environmental Laboratory

    Energy Technology Data Exchange (ETDEWEB)

    Teresa R. Meachum

    2004-02-01

    The 2003 Wastewater Land Application Site Performance Reports for the Idaho National Engineering and Environmental Laboratory describe the conditions for the facilities with State of Idaho Wastewater Land Application Permits. Permit-required monitoring data are summarized, and permit exceedences or environmental impacts relating to the operations of the facilities during the 2003 permit year are discussed.

  17. 2002 Wastewater Land Application Site Performance Reports for the Idaho National Engineering and Environmental Laboratory

    Energy Technology Data Exchange (ETDEWEB)

    Meachum, T.R.; Lewis, M.G.

    2003-02-20

    The 2002 Wastewater Land Application site Performance Reports for the Idaho National Engineering and Environmental Laboratory describe site conditions for the facilities with State of Idaho Wastewater Land Application Permits. Permit-required monitoring data are summarized, and permit exceedences or environmental impacts relating to the operation of the facilities during the 2002 permit year are discussed.

  18. Semantic Sensors for Rapid Application Development for Environmental Management

    Science.gov (United States)

    Corcho, Oscar

    2010-05-01

    Critical environmental management decisions depend on information provided by a variety of sources (e.g., legacy databases with historical data, real-time data coming from various kinds of sensor networks, mathematical models and simulations, etc.). As the cost of deploying intelligent sensor networks falls, we expect to see more sensor networks being deployed, and an even greater dependence on information coming from sensor networks for better situation assessment and decision making. As a result, decision support systems for environmental management will face the following challenges: - They will need to perform computations (for data fusion and integration, mining and other purposes) on large amounts of real-time data stemming from heterogeneous, autonomously developed and deployed sensor networks possibly combined with other existing data sources. - They will need to respond to sensed data in real-time, possibly adapting the behaviour of the sensor network, to respond to emergency situations. - They will have to deal with very dynamic sensor network sources and changing application requirements that might call for using data in new and possibly unexpected ways, outside the immediate scope of the project where they were deployed. Therefore, it will be common for third parties to integrate and enrich data from historical databases, live sensor networks that were deployed independently by different providers and other sources in order to support their decisions (e.g., flood warning, fire warning, etc.). In most cases, there is a clear need for third parties to be able to use data unexpectedly in a manner that was not previously envisioned (e.g., satellite products, data from tidal gauges, etc.), and make relevant data and information easily publishable using Web and mobile communications. We will present the advances that we have made in this direction in the context of the SemsorGrid4Env project, where we have proposed an architecture and technologies covering

  19. Reduction of phase temporal fluctuations caused by digital voltage addressing in LC SLM "HoloEye PLUTO VIS" for holographic applications

    Science.gov (United States)

    Cheremkhin, Pavel A.; Evtikhiev, Nikolay N.; Krasnov, Vitaly V.; Rodin, Vladislav G.; Starikov, Sergey N.

    2014-02-01

    Phase liquid crystal spatial light modulators (LC SLM) are widely used in optical applications such as real-time imaging of holograms and diffractive optical elements, which require high stability and linearity of phase modulation. However state of the art LC SLM with high resolution use digital voltage addressing scheme which, unfortunately, leads to phase fluctuations in time period of one frame. Fluctuations characteristics depend on SLM voltage addressing sequence used. We report results of measurement of phase characteristics of LC SLM "HoloEye PLUTO VIS". This SLM is supplied with three different addressing sequences: "18-6", "5-5" and "0-6". Dynamics of phase fluctuations were measured for all signal values (0-255) with temporal resolution of 0.5 ms in time period of one frame for available addressing sequences. Default sequence "18-6" provided phase deviation 0.24 pi. Lowest deviation 0.07 pi was achieved with sequence "0-6". Due to high periodicity of fluctuations it is possible to implement synchronization of SLM and registering camera or light source to reduce fluctuation effects. This was experimentally implemented using DVI video signal for synchronization of SLM and camera. With its application minimum phase deviation 0.013 pi was achieved with sequence "18-6" which is 5 times lower than achievable without synchronization.

  20. Environmental pollution and DNA methylation: carcinogenesis, clinical significance, and practical applications.

    Science.gov (United States)

    Cao, Yi

    2015-09-01

    Environmental pollution is one of the main causes of human cancer. Exposures to environmental carcinogens result in genetic and epigenetic alterations which induce cell transformation. Epigenetic changes caused by environmental pollution play important roles in the development and progression of environmental pollution-related cancers. Studies on DNA methylation are among the earliest and most conducted epigenetic research linked to cancer. In this review, the roles of DNA methylation in carcinogenesis and their significance in clinical medicine were summarized, and the effects of environmental pollutants, particularly air pollutants, on DNA methylation were introduced. Furthermore, prospective applications of DNA methylation to environmental pollution detection and cancer prevention were discussed.

  1. Efficient Low Voltage Amplification Using Self Starting Voltage Regulator for Storage System

    Directory of Open Access Journals (Sweden)

    Haslinah Binti Mohd Nasir

    2014-10-01

    Full Text Available This paper presents a storage system design based on energy harvesting to achieve batteryless for Wireless Sensor Network (WSN application. The storage system is part of the Wireless Sensor Energy Harvesting to store and amplify the energy harvested from the surroundings. Finding a new sources of renewable energy has becomes a fashionable among researchers nowadays in particular harvesting the energy from the surrounding. However the challenge raised is to boost up the energy that known are very low. Thus the proposed method must be consumes very little power and suitable for ambient environmental sources such as vibration, wind and RF energy and be able to boost up the energy for storage system. The output of the harvested voltage is insufficient for most applications, therefore the system will boost up the input voltage level using DC to DC converter topology to higher dc voltage.The DC to DC converter shall be designed to suit the types of storage required. The output voltage of this DC converter should be sufficient to charge either capacitor or supercapacitor that will be use in this system as the energy storage system. The supercapacitor will provide power to energize any system such as in this case wireless sensor network[1]. In the case of wireless sensor network for example, the node would require the energy during transmitting and receiving data only whereas during standby mode or sleep mode, the amount of energy required would be very small[2]. Therefore the storage system will make use of this standby time or sleep mode of the sensor node to store as much energy as possible. The presented DC to DC converter in this paper has high efficiency upto 85.4% with input voltage between range 300mV to 600mV.

  2. High voltage electricity installations a planning perspective

    CERN Document Server

    Jay, Stephen Andrew

    2006-01-01

    The presence of high voltage power lines has provoked widespread concern for many years. High Voltage Electricity Installations presents an in-depth study of policy surrounding the planning of high voltage installations, discussing the manner in which they are percieved by the public, and the associated environmental issues. An analysis of these concerns, along with the geographical, environmental and political influences that shape their expression, is presented. Investigates local planning policy in an area of the energy sector that is of highly topical environmental and public concern Cover

  3. Application of Stochastic Automata Networks for Creation of Continuous Time Markov Chain Models of Voltage Gating of Gap Junction Channels

    Directory of Open Access Journals (Sweden)

    Mindaugas Snipas

    2015-01-01

    Full Text Available The primary goal of this work was to study advantages of numerical methods used for the creation of continuous time Markov chain models (CTMC of voltage gating of gap junction (GJ channels composed of connexin protein. This task was accomplished by describing gating of GJs using the formalism of the stochastic automata networks (SANs, which allowed for very efficient building and storing of infinitesimal generator of the CTMC that allowed to produce matrices of the models containing a distinct block structure. All of that allowed us to develop efficient numerical methods for a steady-state solution of CTMC models. This allowed us to accelerate CPU time, which is necessary to solve CTMC models, ∼20 times.

  4. Application of stochastic automata networks for creation of continuous time Markov chain models of voltage gating of gap junction channels.

    Science.gov (United States)

    Snipas, Mindaugas; Pranevicius, Henrikas; Pranevicius, Mindaugas; Pranevicius, Osvaldas; Paulauskas, Nerijus; Bukauskas, Feliksas F

    2015-01-01

    The primary goal of this work was to study advantages of numerical methods used for the creation of continuous time Markov chain models (CTMC) of voltage gating of gap junction (GJ) channels composed of connexin protein. This task was accomplished by describing gating of GJs using the formalism of the stochastic automata networks (SANs), which allowed for very efficient building and storing of infinitesimal generator of the CTMC that allowed to produce matrices of the models containing a distinct block structure. All of that allowed us to develop efficient numerical methods for a steady-state solution of CTMC models. This allowed us to accelerate CPU time, which is necessary to solve CTMC models, ~20 times.

  5. Fabrication of universal serial bus flash disk type microfluidic chip electrophoresis and application for protein analysis under ultra low voltage.

    Science.gov (United States)

    Cong, Hailin; Xu, Xiaodan; Yu, Bing; Liu, Huwei; Yuan, Hua

    2016-03-01

    A simple and effective universal serial bus (USB) flash disk type microfluidic chip electrophoresis (MCE) was developed by using poly(dimethylsiloxane) based soft lithography and dry film based printed circuit board etching techniques in this paper. The MCE had a microchannel diameter of 375 μm and an effective length of 25 mm. Equipped with a conventional online electrochemical detector, the device enabled effectively separation of bovine serum albumin, lysozyme, and cytochrome c in 80 s under the ultra low voltage from a computer USB interface. Compared with traditional capillary electrophoresis, the USB flash disk type MCE is not only portable and inexpensive but also fast with high separation efficiency.

  6. A New Method of Random Environmental Walking for Assessing Behavioral Preferences for Different Lighting Applications.

    Science.gov (United States)

    Patching, Geoffrey R; Rahm, Johan; Jansson, Märit; Johansson, Maria

    2017-01-01

    Accurate assessment of people's preferences for different outdoor lighting applications is increasingly considered important in the development of new urban environments. Here a new method of random environmental walking is proposed to complement current methods of assessing urban lighting applications, such as self-report questionnaires. The procedure involves participants repeatedly walking between different lighting applications by random selection of a lighting application and preferred choice or by random selection of a lighting application alone. In this manner, participants are exposed to all lighting applications of interest more than once and participants' preferences for the different lighting applications are reflected in the number of times they walk to each lighting application. On the basis of an initial simulation study, to explore the feasibility of this approach, a comprehensive field test was undertaken. The field test included random environmental walking and collection of participants' subjective ratings of perceived pleasantness (PP), perceived quality, perceived strength, and perceived flicker of four lighting applications. The results indicate that random environmental walking can reveal participants' preferences for different lighting applications that, in the present study, conformed to participants' ratings of PP and perceived quality of the lighting applications. As a complement to subjectively stated environmental preferences, random environmental walking has the potential to expose behavioral preferences for different lighting applications.

  7. Application of Health Promotion Theories and Models for Environmental Health

    Science.gov (United States)

    Parker, Edith A.; Baldwin, Grant T.; Israel, Barbara; Salinas, Maria A.

    2004-01-01

    The field of environmental health promotion gained new prominence in recent years as awareness of physical environmental stressors and exposures increased in communities across the country and the world. Although many theories and conceptual models are used routinely to guide health promotion and health education interventions, they are rarely…

  8. Applications of Environmental Psychology in Programming for Severely Handicapped Persons.

    Science.gov (United States)

    Baker, Dixie Branner

    1980-01-01

    Theory and research from the field of environmental psychology are reviewed and implications regarding environmental programing for severely handicapped individuals are discussed. A challenge is issued to design for severely handicapped persons environments which are both manageable and consistent with normalization tenets. (Author)

  9. 2001 Wastewater Land Application Site Performance Reports for the Idaho National Engineering and Environmental Laboratory

    Energy Technology Data Exchange (ETDEWEB)

    Meachum, Teresa Ray; Lewis, Michael George

    2002-02-01

    The 2001 Wastewater Land Application Site Performance Reports for the Idaho National Engineering and Environmental Laboratory describe site conditions for the facilities with State of Idaho Wastewater Land Application Permits. Permit-required monitoring data are summarized, and any permit exceedences or environmental impacts relating to the operation of any of the facilities during the 2001 permit year are discussed. Additionally, any special studies performed at the facilities, which related to the operation of the facility or application of the wastewater, are discussed.

  10. 2001 Wastewater Land Application Site Performance Reports for the Idaho National Engineering and Environmental Laboratory

    Energy Technology Data Exchange (ETDEWEB)

    Meachum, T.R.; Lewis, M.G.

    2002-02-15

    The 2001 Wastewater Land Application Site Performance Reports for the Idaho National Engineering and Environmental Laboratory describe site conditions for the facilities with State of Idaho Wastewater Land Application Permits. Permit-required monitoring data are summarized, and any permit exceedences or environmental impacts relating to the operation of any of the facilities during the 2001 permit year are discussed. Additionally, any special studies performed at the facilities, which related to the operation of the facility or application of the wastewater, are discussed.

  11. Structure-property relationships in an Al matrix Ca nanofilamentary composite conductor with potential application in high-voltage power transmission

    Science.gov (United States)

    Tian, Liang

    This study investigated the processing-structure-properties relationships in an Al/Ca composites using both experiments and modeling/simulation. A particular focus of the project was understanding how the strength and electrical conductivity of the composite are related to its microstructure in the hope that a conducting material with light weight, high strength, and high electrical conductivity can be developed to produce overhead high-voltage power transmission cables. The current power transmission cables (e.g., Aluminum Conductor Steel Reinforced (ACSR)) have acceptable performance for high-voltage AC transmission, but are less well suited for high-voltage DC transmission due to the poorly conducting core materials that support the cable weight. This Al/Ca composite was produced by powder metallurgy and severe plastic deformation by extrusion and swaging. The fine Ca metal powders have been produced by centrifugal atomization with rotating liquid oil quench bath, and a detailed study about the atomization process and powder characteristics has been conducted. The microstructure of Al/Ca composite was characterized by electron microscopy. Microstructure changes at elevated temperature were characterized by thermal analysis and indirect resistivity tests. The strength and electrical conductivity were measured by tensile tests and four-point probe resistivity tests. Predicting the strength and electrical conductivity of the composite was done by micro-mechanics-based analytical modeling. Microstructure evolution was studied by mesoscale-thermodynamics-based phase field modeling and a preliminary atomistic molecular dynamics simulation. The application prospects of this composite was studied by an economic analysis. This study suggests that the Al/Ca (20 vol. %) composite shows promise for use as overhead power transmission cables. Further studies are needed to measure the corrosion resistance, fatigue properties and energized field performance of this composite.

  12. A Method to Assess Risk of Voltage Collapse and Its Application%电压崩溃的风险评估方法及应用

    Institute of Scientific and Technical Information of China (English)

    周启航; 张东霞; 郭强; 马世英

    2011-01-01

    As a traditional method, the deterministic method is currently applied in assessment of power system voltage collapse. Usually deterministic method considers the severe accidents with low occurrence probability, so that the assessment results frequently tend to conservative. The risk assessment method takes the occurrence probability and effects of accidents into account comprehensively, so its development potential will be desirable. A risk assessment method for power system voltage collapse is proposed and taking IEEE 14-bus system as the object its application research is performed. By means of analyzing the relation between the configured capacity of parallel capacitor and the risk of voltage collapse, a risk curve-based approach to determine optimal configuration of parallel capacitor is proposed.%传统的电力系统电压崩溃评估方法是确定性方法.确定性方法通常考虑较为严重但发生概率较低的事件,所以常常导致评估结果保守.风险评估方法可以综合考虑事件的发生概率和后果,有很好的发展前景.提出了一种电力系统电压崩溃的风险评估方法,并针对IEEE 14节点系统进行了应用研究.文章还通过分析并联电容器的配置容量和电压崩溃风险的关系,提出了一种根据风险曲线确定并联电容器最优配置的方法.

  13. Research on Application of Internet of Things in the Disposal of Environmental Emergency

    Directory of Open Access Journals (Sweden)

    Zhu Yanju

    2015-01-01

    Full Text Available Internet of things is an important part of a new generation of information technology and also an important stage of Information Age. Application of Internet of things in the disposal of environmental emergency is an inevitable trend of application of Internet of things in the field of environmental protection. This paper summarizes the principle, process and application field of Internet of things, and focuses on the general frame-work of environmental emergency disposal system based on Internet of things and further analyses the factors of restricting application of Internet of things in the disposal of environmental emergency. At last, the suggestions and countermeasures to optimize environmental emergency disposal system are proposed.

  14. Environmental concepts in rural Honduras: A case study of their range and application within environmental education design

    Science.gov (United States)

    Bradford, Robert Sanders

    1998-12-01

    The rate of environmental degradation in the Third World continues to present residents of countries like Honduras with conditions that threaten the quality of life and ecological systems. How people conceptualize their environment could be a point of entry into a greater understanding of environmental problems. Through individual interviews and focus group discussions, this study comprises a qualitative examination of the environmental concepts of a sample of 75 rural Hondurans. Analysis of their concepts was used to construct a tentative interpretation of the rural Honduran worldview characteristics of Self, Other, Relationship, Classification, Causality, Time, and Space. The findings of this investigation indicated that rural Hondurans conceptualize their environment through the worldview lenses of survival and poverty, leading to a sense of fatalism when confronting the complex and multifaceted problems associated with quality of life and environmental quality. Analysis of concepts and worldview also indicated that rural Hondurans generally do not believe their environmental problems are solvable, nor do they appear to understand that these problems are also cultural problems whose solutions will most likely require some revision of their current worldview. An educational approach that fosters the integration of compatible environmental concepts into the rural Honduran worldview is recommended through the application of design strategies for a prospective environmental education process.

  15. Piezo Voltage Controlled Planar Hall Effect Devices

    Science.gov (United States)

    Zhang, Bao; Meng, Kang-Kang; Yang, Mei-Yin; Edmonds, K. W.; Zhang, Hao; Cai, Kai-Ming; Sheng, Yu; Zhang, Nan; Ji, Yang; Zhao, Jian-Hua; Zheng, Hou-Zhi; Wang, Kai-You

    2016-06-01

    The electrical control of the magnetization switching in ferromagnets is highly desired for future spintronic applications. Here we report on hybrid piezoelectric (PZT)/ferromagnetic (Co2FeAl) devices in which the planar Hall voltage in the ferromagnetic layer is tuned solely by piezo voltages. The change of planar Hall voltage is associated with magnetization switching through 90° in the plane under piezo voltages. Room temperature magnetic NOT and NOR gates are demonstrated based on the piezo voltage controlled Co2FeAl planar Hall effect devices without the external magnetic field. Our demonstration may lead to the realization of both information storage and processing using ferromagnetic materials.

  16. Piezo Voltage Controlled Planar Hall Effect Devices.

    Science.gov (United States)

    Zhang, Bao; Meng, Kang-Kang; Yang, Mei-Yin; Edmonds, K W; Zhang, Hao; Cai, Kai-Ming; Sheng, Yu; Zhang, Nan; Ji, Yang; Zhao, Jian-Hua; Zheng, Hou-Zhi; Wang, Kai-You

    2016-06-22

    The electrical control of the magnetization switching in ferromagnets is highly desired for future spintronic applications. Here we report on hybrid piezoelectric (PZT)/ferromagnetic (Co2FeAl) devices in which the planar Hall voltage in the ferromagnetic layer is tuned solely by piezo voltages. The change of planar Hall voltage is associated with magnetization switching through 90° in the plane under piezo voltages. Room temperature magnetic NOT and NOR gates are demonstrated based on the piezo voltage controlled Co2FeAl planar Hall effect devices without the external magnetic field. Our demonstration may lead to the realization of both information storage and processing using ferromagnetic materials.

  17. Application of Environmental Management in Danish Companies: The Statistical Approach

    DEFF Research Database (Denmark)

    Madsen, Henning; Ulhøi, John Parm

    1997-01-01

    Human activities cannot avoid to influence conditions in the natural environment one way or the other. This includes as well common activities in the business sector. But during the past few decades, environmental disasters in Seveso and Bhopal, and the Exxon Valdes oil spill in Alaska have...... contributed to an increasing awareness of the effect of business activities on the physical environment. To assist companies reduce, evaluate, monitor and control their environmental impact the concept of corporate environmental and resource management has been developed. Implementation of this concept...

  18. High Voltage Seismic Generator

    Science.gov (United States)

    Bogacz, Adrian; Pala, Damian; Knafel, Marcin

    2015-04-01

    This contribution describes the preliminary result of annual cooperation of three student research groups from AGH UST in Krakow, Poland. The aim of this cooperation was to develop and construct a high voltage seismic wave generator. Constructed device uses a high-energy electrical discharge to generate seismic wave in ground. This type of device can be applied in several different methods of seismic measurement, but because of its limited power it is mainly dedicated for engineering geophysics. The source operates on a basic physical principles. The energy is stored in capacitor bank, which is charged by two stage low to high voltage converter. Stored energy is then released in very short time through high voltage thyristor in spark gap. The whole appliance is powered from li-ion battery and controlled by ATmega microcontroller. It is possible to construct larger and more powerful device. In this contribution the structure of device with technical specifications is resented. As a part of the investigation the prototype was built and series of experiments conducted. System parameter was measured, on this basis specification of elements for the final device were chosen. First stage of the project was successful. It was possible to efficiently generate seismic waves with constructed device. Then the field test was conducted. Spark gap wasplaced in shallowborehole(0.5 m) filled with salt water. Geophones were placed on the ground in straight line. The comparison of signal registered with hammer source and sparker source was made. The results of the test measurements are presented and discussed. Analysis of the collected data shows that characteristic of generated seismic signal is very promising, thus confirms possibility of practical application of the new high voltage generator. The biggest advantage of presented device after signal characteristics is its size which is 0.5 x 0.25 x 0.2 m and weight approximately 7 kg. This features with small li-ion battery makes

  19. Environmental Standard Review Plan for the review of license renewal applications for nuclear power plants

    Energy Technology Data Exchange (ETDEWEB)

    O' Brien, J.; Kim, T.J.; Reynolds, S.

    1991-08-01

    The Environmental Standard Review Plan for the Review of License Applications for Nuclear Power Plants (ESRP-LR) is to be used by the NRC staff when performing environmental reviews of applications for the renewal of power reactor licenses. The use of the ESRP-LR provides a framework for the staff to determine whether or not environmental issues important to license renewal have been identified and the impacts evaluated and provides acceptance standards to help the reviewers comply with the National Environmental Policy Act.

  20. Research and Application of a Variety of Meteorology and Environment Monitoring and Early Warning Model about High Voltage Transmission Line’ s Operating Conditions%高压线路运行环境监测预警研究

    Institute of Scientific and Technical Information of China (English)

    杨莉; 赵薇; 沈映泉; 罗学礼; 王森

    2014-01-01

    With the transmission line condition monitoring of the fine level continues to increase,the research on a variety of envi-ronmental information model which is combination of different environmental factors and is established from the perspective of fusion analysis about multiple data is needed� For the Yunnan-specific environmental factors,this paper established fires and ice monito-ring and early warning model based on temperature,humidity,wind speed and other factors� This model monitoring and early warn-ing the high-voltage transmission Yunnan line operating condition� Practical application shows that the early warning model is accu-rately and efficiently,which can effectively cover an iceberg early warning fire and other disasters,in order to protect the safety and stable operation of transmission lines.%介绍从多种数据融合分析的角度建立开展多种环境信息模型的研究�本文针对云南省特有的环境因素,建立了基于温度、湿度、风速等因素的覆冰和山火监测预警模型,对云南省高压输电线路运行工况进行监测预警,实际应用表明预警模型精确有效,能够有效地对覆冰山火等灾害进行预警,从而保障输电线路的安全稳定运行。

  1. The application of environmental certification to the Province of Siena.

    Science.gov (United States)

    Ridolfi, R; Andreis, D; Panzieri, M; Ceccherini, F

    2008-01-01

    The SPIn-Eco project has provided very broad and precise data collection regarding the Province of Siena. These data and their elaborations have also been developed as a basis for the environmental certification of this organization. In this way, the Administration of the Province of Siena (the first Province in Italy) has reached its goal of obtaining better knowledge of the state of the system and of constructing its environmental management system (EMS) according to the environmental aspects directly and indirectly arising from the organization's activities. Indirect aspects are mainly related to the territorial monitoring and planning. Indicators based on the classical pressure-state-response approach, as well as more complex ones based on CO(2) balance, emergy and ecological footprint analyses, have been used to assess the environmental performance of the EMS. This paper presents how this EMS is constructed, as well as the indicators that are used to analyze the system, paying particular attention to sustainability indicators.

  2. Environmental Ethics in Theory and Practical Application | Kelbessa ...

    African Journals Online (AJOL)

    Open Access DOWNLOAD FULL TEXT Subscription or Fee Access ... However, this study and the contribution of many scholars show that ... can bring the insights of environmental ethics into various natural resource management settings.

  3. Application of automated bioacoustic identification in environmental education and assessment

    Directory of Open Access Journals (Sweden)

    Oba Teruyo

    2004-01-01

    Full Text Available Developments in electronics and computer science have led to the introduction of an automated bioacoustic identification device used to resolve commonly encountered problems in the identification of animal species in the field. This technology aids our auditory observations, and also improves the quality of biological surveys and environmental monitoring. In this paper the future roles and possibilities of bioacoustics are discussed, providing some examples from the realm of environmental education and monitoring that focus on the use of nature sounds.

  4. Application of neutron activation tracer sediment technique on environmental science

    Institute of Scientific and Technical Information of China (English)

    YinYi; ZhongWei-Ni; 等

    1997-01-01

    Field and laboratory inverstigations were carried out to study the transport and dispersion law of polluted sediments near wastewater outlet using neutron activation tracer technique.The direction of transport and dispersion of polluted sediments,dispersion amount in different directions,sedimentary region of polluted sediment and evaluation of polluted risk are given.This provided a new test method for the study of environmental science and added a new forecasted content for the evaluation of environmental influence.

  5. Application of a predictive Bayesian model to environmental accounting.

    Science.gov (United States)

    Anex, R P; Englehardt, J D

    2001-03-30

    Environmental accounting techniques are intended to capture important environmental costs and benefits that are often overlooked in standard accounting practices. Environmental accounting methods themselves often ignore or inadequately represent large but highly uncertain environmental costs and costs conditioned by specific prior events. Use of a predictive Bayesian model is demonstrated for the assessment of such highly uncertain environmental and contingent costs. The predictive Bayesian approach presented generates probability distributions for the quantity of interest (rather than parameters thereof). A spreadsheet implementation of a previously proposed predictive Bayesian model, extended to represent contingent costs, is described and used to evaluate whether a firm should undertake an accelerated phase-out of its PCB containing transformers. Variability and uncertainty (due to lack of information) in transformer accident frequency and severity are assessed simultaneously using a combination of historical accident data, engineering model-based cost estimates, and subjective judgement. Model results are compared using several different risk measures. Use of the model for incorporation of environmental risk management into a company's overall risk management strategy is discussed.

  6. Investigation of Current-Voltage Characteristics of Ni/GaN Schottky Barrier Diodes for Potential HEMT Applications

    Directory of Open Access Journals (Sweden)

    Ashish Kumar

    2011-01-01

    Full Text Available In the present work, the I-V characteristics of Ni/GaN Schottky diodes have been studied. The Schottky diodes, having different sizes using Ni/Au and ohmic contacts using Ti/Al/Ni/Au were made on n-GaN. The GaN was epitaxially grown on c-plane sapphire by metal organic chemical vapor deposition (MOCVD technique and had a thickness of about 3.7 µm. The calculated ideality factor and barrier height from current-voltage (I-V characteristics (at 300 K for two GaN Schottky diodes were close to ~1.3 and ~ 0.8 eV respectively. A high reverse leakage current in the order of 10 – 4A/cm2 (at – 1 V was observed in both diodes. A careful analysis of forward bias I-V characteristics showed very high series resistance and calculation for ideality factor indicated presence of other current transport mechanism apart from thermionic model at room temperature.

  7. Application of HFCT and UHF Sensors in On-Line Partial Discharge Measurements for Insulation Diagnosis of High Voltage Equipment

    Directory of Open Access Journals (Sweden)

    Fernando Álvarez

    2015-03-01

    Full Text Available Partial discharge (PD measurements provide valuable information for assessing the condition of high voltage (HV insulation systems, contributing to their quality assurance. Different PD measuring techniques have been developed in the last years specially designed to perform on-line measurements. Non-conventional PD methods operating in high frequency bands are usually used when this type of tests are carried out. In PD measurements the signal acquisition, the subsequent signal processing and the capability to obtain an accurate diagnosis are conditioned by the selection of a suitable detection technique and by the implementation of effective signal processing tools. This paper proposes an optimized electromagnetic detection method based on the combined use of wideband PD sensors for measurements performed in the HF and UHF frequency ranges, together with the implementation of powerful processing tools. The effectiveness of the measuring techniques proposed is demonstrated through an example, where several PD sources are measured simultaneously in a HV installation consisting of a cable system connected by a plug-in terminal to a gas insulated substation (GIS compartment.

  8. Mechanism of Fast Current Interruption in p -π -n Diodes for Nanosecond Opening Switches in High-Voltage-Pulse Applications

    Science.gov (United States)

    Sharabani, Y.; Rosenwaks, Y.; Eger, D.

    2015-07-01

    Step-recovery diodes operating in the snappy recovery regime are used as opening switches for generating narrow pulses with high-voltage amplitude. Physical modeling of the switching process is complex due to the large number of parameters involved, including diode structure, the extreme physical conditions, and the effect of external driving conditions. In this work, we address the problem by using a physical device simulator for solving the coupled device and electrical driving circuit equations. This method allows deciphering of the physical processes to take place in the diode during the fast current interruption phase. Herein we analyze the complete hard (snappy) reverse recovery process in short-base devices and determine the fast-transition-phase mechanism. It was found that the fast current interruption phase is constructed of two processes; the main parameters governing the switching time duration and the prepulse magnitude are the diode's reverse current density and its base-doping concentration. We describe the dependence of the switching performance in these parameters.

  9. Section IV.D.3 for DOE 2013 Annual Report: Novel Phosphazene-based Compounds to Enhance Safety and Stability of Cell Chemistries for High Voltage Applications (INL)

    Energy Technology Data Exchange (ETDEWEB)

    Kevin L. Gering; Mason K. Harrup; Eric J. Dufek; Sergiy V. Sazhin; Harry W. Rollins; David K. Jamison; Fred F. Stewart; John Burba

    2013-09-01

    Electrolytes play a central role in performance and aging in most electrochemical systems. As automotive and grid applications place a higher reliance on electrochemical stored energy, it becomes more urgent to have electrolyte components that enable optimal battery performance while promoting battery safety and longevity. Safety remains a foremost concern for widespread utilization of Li-ion technology in electric-drive vehicles, especially as the focus turns to higher voltage systems (5V). This work capitalizes on the long established INL expertise regarding phosphazene chemistry, aimed at battery-viable compounds for electrolytes and electrodes that are highly tolerant to abusive conditions. This report showcases our 2013 work for the DOE applied battery research (ABR) program, wherein testing results are summarized for INL electrolytes and alternative anode materials.

  10. A 3.01-3.82 GHz CMOS LC voltage-controlled oscillator with 6.29% VCO-gain variation for WLAN applications

    Science.gov (United States)

    Xiaolong, Liu; Lei, Zhang; Li, Zhang; Yan, Wang; Zhiping, Yu

    2014-07-01

    A wideband low-phase-noise LC voltage-controlled oscillator (VCO) with low VCO gain (KVCO) variation for WLAN fractional-N frequency synthesizer application is proposed and designed on a 0.13-μm CMOS process. In order to achieve a low KVCO variation, an extra switched varactor array was added to the LC tank with the conventional switched capacitor array. Based on the proposed switched varactor array compensation technique, the measured KVCO is 43 MHz/V with only 6.29% variation across the entire tuning range. The proposed VCO provides a tuning range of 23.7% from 3.01 to 3.82 GHz, while consuming 9 mA of quiescent current from a 2.3 V supply. The VCO shows a low phase noise of -121.94 dBc/Hz at 1 MHz offset, from the 3.6 GHz carrier.

  11. Low-Voltage Switched-Capacitor Circuits

    DEFF Research Database (Denmark)

    Bidari, E.; Keskin, M.; Maloberti, F.

    1999-01-01

    Switched-capacitor stages are described which can function with very low (typically 1 V) supply voltages, without using voltage boosting or switched op-amps. Simulations indicate that high performance may be achieved using these circuits in filter or data converter applications.......Switched-capacitor stages are described which can function with very low (typically 1 V) supply voltages, without using voltage boosting or switched op-amps. Simulations indicate that high performance may be achieved using these circuits in filter or data converter applications....

  12. Intelligence systems in environmental management theory and applications

    CERN Document Server

    Sari, İrem

    2017-01-01

    This book offers a comprehensive reference guide to intelligence systems in environmental management. It provides readers with all the necessary tools for solving complex environmental problems, where classical techniques cannot be applied. The respective chapters, written by prominent researchers, explain a wealth of both basic and advanced concepts including ant colony, genetic algorithms, evolutionary algorithms, fuzzy multi-criteria decision making tools, particle swarm optimization, agent-based modelling, artificial neural networks, simulated annealing, Tabu search, fuzzy multi-objective optimization, fuzzy rules, support vector machines, fuzzy cognitive maps, cumulative belief degrees, and many others. To foster a better understanding, all the chapters include relevant numerical examples or case studies. Taken together, they form an excellent reference guide for researchers, lecturers and postgraduate students pursuing research on complex environmental problems. Moreover, by extending all the main aspec...

  13. Capillary electrophoresis with laser-induced fluorescence: environmental applications.

    Science.gov (United States)

    Riddick, Lee; Brumley, William C

    2008-01-01

    Capillary electrophoresis (CE), especially free-zone CE, offers a relatively simple separation with moderate selectivity based on the mobility of ions in solution. Laser-induced fluorescence (LIF) detection, an extremely sensitive technique, can be coupled with a variety of separation conditions to achieve sensitive and quantitative results. When these techniques are combined, CE/LIF provides the sensitivity and increased selectivity that makes trace level environmental analysis of fluorescent compounds possible at or below levels typical for gas chromatography (GC)/mass spectrometry (MS). We offer a panoramic review of the role of these tools in solving environmental and related analytical problems before providing a detailed experimental protocol.

  14. A Web-Based Spectral Database for Environmental Application

    Directory of Open Access Journals (Sweden)

    Jing Fang

    2007-12-01

    Full Text Available The administration and storage of environmental characteristic spectral data are highly relevant in many fields of environmental study, such as measurement of trace gases in the atmosphere and air quality estimation. For this reason, a web-accessible database has been developed, offering ready access to the main parameters of molecular absorption spectral data. Web-based and friendly interfaces allow for interactive queries as well as previews of plots and downloads of files of the resulting spectral data for thorough comparative analyses.

  15. Empirical applications of an environmental stress indicator and the environmental efficiency revolution in Taiwan

    Directory of Open Access Journals (Sweden)

    Han-Shen Chen

    2013-09-01

    Full Text Available In this essay, the first aim is to apply the structure of material flow analysis (MFA and ecological footprint model to construct an environmental stress indicator. Secondly, an impact, population, affluence and technology (IPAT analysis is used to resolve indicators related to MFA and resource yield productivity. The research indicates following results: (1 The 2007 per capita ecological deficit in Taiwan is 6.3441 square hm.The figures reflect that productivity and life intensity of residents have exceeded the carrying capacity of Taiwan's ecological economic system. (2 Wealth becomes the most important factor in material needs and pollution discharge. (3 Environmental efficiency and ecological efficiency slowed down dramatically, demonstrating that use of resources and total amount of environmental stress stay at a developmental stage. Therefore, if proper measures are not adopted, the current weak sustainability will lead into the vicious circle which departs from sustainable development.

  16. Laser applications to chemical, security, and environmental analysis: introduction to the feature issue.

    Science.gov (United States)

    Seeger, Thomas; Dreier, Thomas; Chen, Weidong; Kearny, Sean; Kulatilaka, Waruna

    2017-04-10

    This Applied Optics feature issue on laser applications to chemical, security, and environmental analysis (LACSEA) highlights papers presented at the LACSEA 2016 Fifteenth Topical Meeting sponsored by the Optical Society of America.

  17. Design of TiO2-loaded Porous Siliceous Materials and Application to Photocatalytic Environmental Purification

    National Research Council Canada - National Science Library

    KAMEGAWA, Takashi; KUWAHARA, Yasutaka; YAMASHITA, Hiromi

    2016-01-01

    ... with additional functions. This review mainly describes our recent investigations on the design of TiO2-loaded porous siliceous materials for application to photocatalytic environmental purification via efficient adsorption...

  18. Speciation analysis of 129I and its applications in environmental research

    DEFF Research Database (Denmark)

    Zhang, Luyuan; Hou, Xiaolin

    2013-01-01

    129I, a long-lived radionuclide, is important in view of geological repository of nuclear waste, and environmental tracing applications related to diverse natural processes of iodine. The environmental behaviors and bioavailability of 129I are highly related to its species. A number of methods have...

  19. 78 FR 37324 - Preparation of Environmental Reports for Nuclear Power Plant License Renewal Applications

    Science.gov (United States)

    2013-06-20

    ... COMMISSION 10 CFR Parts 51 and 54 RIN 3150-AI42 Preparation of Environmental Reports for Nuclear Power Plant..., Supplement 1 (RG 4.2S1), ``Preparation of Environmental Reports for Nuclear Power Plant License Renewal... reports that are submitted with the application for the renewal of a nuclear power plant operating...

  20. Environmental Applications of 2D Molybdenum Disulfide (MoS2) Nanosheets.

    Science.gov (United States)

    Wang, Zhongying; Mi, Baoxia

    2017-08-01

    In an era of graphene-based nanomaterials as the most widely studied two-dimensional (2D) materials for enhanced performance of devices and systems in numerous environmental applications, molybdenum disulfide (MoS2) nanosheets stand out as a promising alternative 2D material with many excellent physicochemical, biological, and mechanical properties that differ significantly from those of graphene-based nanomaterials, potentially leading to new environmental phenomena and novel applications. This Critical Review presents the latest advances in the use of MoS2 nanosheets for important water-related environmental applications such as contaminant adsorption, photocatalysis, membrane-based separation, sensing, and disinfection. Various methods for MoS2 nanosheet synthesis are examined, and their suitability for different environmental applications is discussed. The unique structure and properties of MoS2 nanosheets enabling exceptional environmental capabilities are compared with those of graphene-based nanomaterials. The environmental implications of MoS2 nanosheets are emphasized, and research needs for future environmental applications of MoS2 nanosheets are identified.

  1. The environmental impact of fibre crops in industrial applications

    NARCIS (Netherlands)

    Dam, van J.E.G.; Bos, H.L.

    2004-01-01

    A short literature survey is presented on health and environmental issues in relation to the production and use of fibre crops. Next a short introduction to Life Cycle Analysis (LCA) is given and the various commonly applied methods for quantifying ecological impacts are discussed in short. The avai

  2. Measuring Social Capital among Youth: Applications in Environmental Education

    Science.gov (United States)

    Krasny, Marianne E.; Kalbacker, Leigh; Stedman, Richard C.; Russ, Alex

    2015-01-01

    Although critiqued for circular reasoning and lack of definitional and analytic clarity, social capital has garnered widespread interest in two areas relevant to environmental education (EE): the impact of family and community-level social capital on positive youth development and of community-level social capital in fostering collective action to…

  3. Measuring Social Capital among Youth: Applications in Environmental Education

    Science.gov (United States)

    Krasny, Marianne E.; Kalbacker, Leigh; Stedman, Richard C.; Russ, Alex

    2015-01-01

    Although critiqued for circular reasoning and lack of definitional and analytic clarity, social capital has garnered widespread interest in two areas relevant to environmental education (EE): the impact of family and community-level social capital on positive youth development and of community-level social capital in fostering collective action to…

  4. Hierarchical modelling for the environmental sciences statistical methods and applications

    CERN Document Server

    Clark, James S

    2006-01-01

    New statistical tools are changing the way in which scientists analyze and interpret data and models. Hierarchical Bayes and Markov Chain Monte Carlo methods for analysis provide a consistent framework for inference and prediction where information is heterogeneous and uncertain, processes are complicated, and responses depend on scale. Nowhere are these methods more promising than in the environmental sciences.

  5. Applications of the green fluorescent protein as a molecular marker in environmental microorganisms.

    Science.gov (United States)

    Errampalli, D; Leung, K; Cassidy, M B; Kostrzynska, M; Blears, M; Lee, H; Trevors, J T

    1999-04-01

    In this review, we examine numerous applications of the green fluorescent protein (GFP) marker gene in environmental microbiology research. The GFP and its variants are reviewed and applications in plant-microbe interactions, biofilms, biodegradation, bacterial-protozoan interactions, gene transfer, and biosensors are discussed. Methods for detecting GFP-marked cells are also examined. The GFP is a useful marker in environmental microorganisms, allowing new research that will increase our understanding of microorganisms in the environment.

  6. Photovoltaic system criteria documents. Volume 3: Environmental issues and evaluation criteria for photovoltaic applications

    Science.gov (United States)

    Koenig, John C.; Billitti, Joseph W.; Tallon, John M.

    1979-01-01

    The environmental issues and evaluation criteria relating to the suitability of sites proposed for photovoltaic (PV) system deployment are identified. The important issues are defined, briefly discussed and then developed into evaluation criteria. System designers are provided with information on the environmental sensitivity of PV systems in realistic applications, background material which indicates the applicability of the siting issues identified, and evaluation criteria are defined to facilitate the selection of sites that maximize PV system operation.

  7. Analysis of the Mechanisms Determining the Thermal and Electrical Properties of Epoxy Nanocomposites for High Voltage Applications

    NARCIS (Netherlands)

    Tsekmes, I.A.

    2016-01-01

    The addition of microsized fillers to polymers, in order to tailor their properties, has been extensively used in many industrial applications since the 1960s. The same approach applies to the field of electrical insulation. Epoxy resin is a widely used polymer in the electrical power sector, but it

  8. Analysis of the Mechanisms Determining the Thermal and Electrical Properties of Epoxy Nanocomposites for High Voltage Applications

    NARCIS (Netherlands)

    Tsekmes, I.A.

    2016-01-01

    The addition of microsized fillers to polymers, in order to tailor their properties, has been extensively used in many industrial applications since the 1960s. The same approach applies to the field of electrical insulation. Epoxy resin is a widely used polymer in the electrical power sector, but it

  9. Transient Voltage Recorder

    Science.gov (United States)

    Medelius, Pedro J. (Inventor); Simpson, Howard J. (Inventor)

    2002-01-01

    A voltage transient recorder can detect lightning induced transient voltages. The recorder detects a lightning induced transient voltage and adjusts input amplifiers to accurately record transient voltage magnitudes. The recorder stores voltage data from numerous monitored channels, or devices. The data is time stamped and can be output in real time, or stored for later retrieval. The transient recorder, in one embodiment, includes an analog-to-digital converter and a voltage threshold detector. When an input voltage exceeds a pre-determined voltage threshold, the recorder stores the incoming voltage magnitude and time of arrival. The recorder also determines if its input amplifier circuits clip the incoming signal or if the incoming signal is too low. If the input data is clipped or too low, the recorder adjusts the gain of the amplifier circuits to accurately acquire subsequent components of the lightning induced transients.

  10. Voltage-controlled low-energy switching of nanomagnets through Ruderman-Kittel-Kasuya-Yosida interactions for magnetoelectric device applications

    Energy Technology Data Exchange (ETDEWEB)

    Ghosh, Bahniman, E-mail: bghosh@utexas.edu; Dey, Rik; Register, Leonard F.; Banerjee, Sanjay K. [Microelectronics Research Center, University of Texas at Austin, 10100 Burnet Road, Bldg. 160, Austin, Texas 78758 (United States)

    2016-07-21

    In this article, we consider through simulation low-energy switching of nanomagnets via electrostatically gated inter-magnet Ruderman-Kittel-Kasuya-Yosida (RKKY) interactions on the surface of three-dimensional topological insulators, for possible memory and nonvolatile logic applications. We model the possibility and dynamics of RKKY-based switching of one nanomagnet by coupling to one or more nanomagnets of set orientation. Potential applications to both memory and nonvolatile logic are illustrated. Sub-attojoule switching energies, far below conventional spin transfer torque (STT)-based memories and even below CMOS logic appear possible. Switching times on the order of a few nanoseconds, comparable to times for STT switching, are estimated for ferromagnetic nanomagnets, but the approach also appears compatible with the use of antiferromagnets which may allow for faster switching.

  11. Voltage-controlled low-energy switching of nanomagnets through Ruderman-Kittel-Kasuya-Yosida interactions for magnetoelectric device applications

    Science.gov (United States)

    Ghosh, Bahniman; Dey, Rik; Register, Leonard F.; Banerjee, Sanjay K.

    2016-07-01

    In this article, we consider through simulation low-energy switching of nanomagnets via electrostatically gated inter-magnet Ruderman-Kittel-Kasuya-Yosida (RKKY) interactions on the surface of three-dimensional topological insulators, for possible memory and nonvolatile logic applications. We model the possibility and dynamics of RKKY-based switching of one nanomagnet by coupling to one or more nanomagnets of set orientation. Potential applications to both memory and nonvolatile logic are illustrated. Sub-attojoule switching energies, far below conventional spin transfer torque (STT)-based memories and even below CMOS logic appear possible. Switching times on the order of a few nanoseconds, comparable to times for STT switching, are estimated for ferromagnetic nanomagnets, but the approach also appears compatible with the use of antiferromagnets which may allow for faster switching.

  12. A wide bandgap silicon carbide (SiC) gate driver for high-temperature and high-voltage applications

    Energy Technology Data Exchange (ETDEWEB)

    Lamichhane, Ranjan [University of Arkansas; Ericson, Milton Nance [ORNL; Frank, Steven Shane [ORNL; BRITTONJr., CHARLES L. [Oak Ridge National Laboratory (ORNL); Marlino, Laura D [ORNL; Mantooth, Alan [University of Arkansas; Francis, Matt [APEI, Inc.; Shepherd, Dr. Paul [University of Arkansas; Glover, Dr. Michael [University of Arkansas; Podar, Mircea [ORNL; Perez, M [University of Arkansas; Mcnutt, Tyler [APEI, Inc.; Whitaker, Mr. Bret [APEI, Inc.; Cole, Mr. Zach [APEI, Inc.

    2014-01-01

    Limitations of silicon (Si) based power electronic devices can be overcome with Silicon Carbide (SiC) because of its remarkable material properties. SiC is a wide bandgap semiconductor material with larger bandgap, lower leakage currents, higher breakdown electric field, and higher thermal conductivity, which promotes higher switching frequencies for high power applications, higher temperature operation, and results in higher power density devices relative to Si [1]. The proposed work is focused on design of a SiC gate driver to drive a SiC power MOSFET, on a Cree SiC process, with rise/fall times (less than 100 ns) suitable for 500 kHz to 1 MHz switching frequency applications. A process optimized gate driver topology design which is significantly different from generic Si circuit design is proposed. The ultimate goal of the project is to integrate this gate driver into a Toyota Prius plug-in hybrid electric vehicle (PHEV) charger module. The application of this high frequency charger will result in lighter, smaller, cheaper, and a more efficient power electronics system.

  13. Programable Driver for Voltage-Controlled Oscillators

    Science.gov (United States)

    Fowler, L. E.; Mcneil, J. A.

    1985-01-01

    Electronically programable read-only memory (EPROM) and digital-to-analog converter provide customized time-varying voltage for frequency modulation. Voltage used to modulate IMPATT oscillator that serves as microwave pump for solid-state maser in low-noise amplifier. EPROM simple to tailor voltage waveform to suit characteristics of given maser. Digital information for waveform programed into EPROM chip; digital-to-analog converter reads information and produces corresponding analog wave. Principle readily adapted to other applications.

  14. Diverse Applications of Environmental DNA Methods in Parasitology.

    Science.gov (United States)

    Bass, David; Stentiford, Grant D; Littlewood, D T J; Hartikainen, Hanna

    2015-10-01

    Nucleic acid extraction and sequencing of genes from organisms within environmental samples encompasses a variety of techniques collectively referred to as environmental DNA or 'eDNA'. The key advantages of eDNA analysis include the detection of cryptic or otherwise elusive organisms, large-scale sampling with fewer biases than specimen-based methods, and generation of data for molecular systematics. These are particularly relevant for parasitology because parasites can be difficult to locate and are morphologically intractable and genetically divergent. However, parasites have rarely been the focus of eDNA studies. Focusing on eukaryote parasites, we review the increasing diversity of the 'eDNA toolbox'. Combining eDNA methods with complementary tools offers much potential to understand parasite communities, disease risk, and parasite roles in broader ecosystem processes such as food web structuring and community assembly.

  15. Environmental applications for an intrinsic germanium well detector

    Energy Technology Data Exchange (ETDEWEB)

    Stegnar, P.; Eldridge, J.S.; Teasley, N.A.; Oakes, T.W.

    1983-01-01

    The overall performance of an intrinsic germanium well detector for /sup 125/I measurements was investigated in a program of environmental surveillance. Concentrations of /sup 125/I and /sup 131/I were determined in thyroids of road-killed deer showing the highest activities of /sup 125/I in the animals from the near vicinity of Oak Ridge National Laboratory. This demonstrates the utility of road-killed deer as a bioindicator for radioiodine around nuclear facilities. 6 refs., 2 figs., 3 tabs.

  16. The application of recycled aluminum and plastics in environmental protection

    OpenAIRE

    G. Tepić; T. Pejakov; Lalić, B.; V. Vukadinović; Milisavljević, S.

    2013-01-01

    Environmental protection is a serious problem facing the modern world. Precisely for this reason, in this work, the authors explore its different aspects. From the perspective of conservation of natural resources and energy savings, the replacement of primary materials through recycling is explored as a potential solution in the elementary processes related to the parasol production. Such parasols would be used in designing “urban forest” solutions, which significantly contribute to the prote...

  17. Model evaluation methodology applicable to environmental assessment models

    Energy Technology Data Exchange (ETDEWEB)

    Shaeffer, D.L.

    1979-08-01

    A model evaluation methodology is presented to provide a systematic framework within which the adequacy of environmental assessment models might be examined. The necessity for such a tool is motivated by the widespread use of models for predicting the environmental consequences of various human activities and by the reliance on these model predictions for deciding whether a particular activity requires the deployment of costly control measures. Consequently, the uncertainty associated with prediction must be established for the use of such models. The methodology presented here consists of six major tasks: model examination, algorithm examination, data evaluation, sensitivity analyses, validation studies, and code comparison. This methodology is presented in the form of a flowchart to show the logical interrelatedness of the various tasks. Emphasis has been placed on identifying those parameters which are most important in determining the predictive outputs of a model. Importance has been attached to the process of collecting quality data. A method has been developed for analyzing multiplicative chain models when the input parameters are statistically independent and lognormally distributed. Latin hypercube sampling has been offered as a promising candidate for doing sensitivity analyses. Several different ways of viewing the validity of a model have been presented. Criteria are presented for selecting models for environmental assessment purposes.

  18. Neutron applications in earth, energy and environmental sciences

    CERN Document Server

    Liang, Liyuan; Schober, Helmut

    2009-01-01

    This text is a comprehensive overview of neutron scattering techniques that enhance the study of materials at the micro and nanoscale. The well structured volume provides introductions to various neutron applications from leading experts in the field.

  19. High voltage research (breakdown strengths of gaseous and liquid insulators) and environmental effects of dielectric gases. Semiannual report, October 1, 1979-March 31, 1980

    Energy Technology Data Exchange (ETDEWEB)

    Christophorou, L.G.; James, D.R.; Pai, R.Y.

    1980-08-01

    Topics covered include basic studies of gaseous dielectrics, direct current breakdown strengths of gases/mixtures, environmental effects studies and decomposition analyses, impulse studies, breakdown strengths of binary mixtures with concentric cylinder geometry, and a discussion of the experimental apparatus. (GHT)

  20. 78 FR 65305 - Coleman Hydro, LLC; Notice of Application Ready for Environmental Analysis and Soliciting...

    Science.gov (United States)

    2013-10-31

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF ENERGY Federal Energy Regulatory Commission Coleman Hydro, LLC; Notice of Application Ready for Environmental Analysis... 22, 2011. d. Applicant: Coleman Hydro, LLC. e. Name of Project: Coleman Hydroelectric Project....

  1. 75 FR 3217 - Eagle Crest Energy Company; Notice of Application Ready for Environmental Analysis and Soliciting...

    Science.gov (United States)

    2010-01-20

    ... Energy Regulatory Commission Eagle Crest Energy Company; Notice of Application Ready for Environmental... filed: June 23, 2009. d. Applicant: Eagle Crest Energy Company. e. Name of Project: Eagle Mountain... Eagle Mountain Mine in Riverside County, California, near the Town of Desert Center, California,...

  2. Applications and Prospective of Peroxidase Biocatalysis in the Environmental Field

    Science.gov (United States)

    Torres-Duarte, Cristina; Vazquez-Duhalt, Rafael

    Environmental protection is, doubtless, one of the most important challenges for the human kind. The huge amount of pollutants derived from industrial activities represents a threat for the environment and ecologic equilibrium. Phenols and halogenated phenols, polycyclic aromatic hydrocarbons, endocrine disruptive chemicals, pesticides, dioxins, polychlorinated biphenyls, industrial dyes, and other xenobiotics are among the most important pollutants. A large variety of these xenobiotics are substrates for peroxidases and thus susceptible to enzymatic transformation. The literature reports mainly the use of horseradish peroxidase, manganese peroxidase, lignin peroxidase, and chloroperoxidase on the transformation of these pollutants. Peroxidases are enzymes able to transform a variety of compounds following a free radical mechanism, giving oxidized or polymerized products. The peroxidase transformation of these pollutants is accompanied by a reduction in their toxicity, due to a biological activity loss, a reduction in the bioavailability or due to the removal from aqueous phase, especially when the pollutant is found in water. In addition, when the pollutants are present in soil, peroxidases catalyze a covalent binding to soil organic matter. In most of cases, oxidized products are less toxic and easily biodegradable than the parent compounds. In spite of their versatility and potential use in environmental processes, peroxidases are not applied at large scale yet. Diverse challenges, such as stability, redox potential, and the production of large amounts, should be solved in order to apply peroxidases in the pollutant transformation. In this chapter, we critically review the transformation of different xenobiotics by peroxidases, with special attention on the identified transformation products, the probable reaction mechanisms, and the toxicity reports. Finally, the design and development of an environmental biocatalyst is discussed. The design challenges are

  3. Energy Storage Options for Voltage Support in Low-Voltage Grids with High Penetration of Photovoltaic

    DEFF Research Database (Denmark)

    Marra, Francesco; Tarek Fawzy, Y.; Bülo, Thorsten

    2012-01-01

    The generation of power by photovoltaic (PV) systems is constantly increasing in low-voltage (LV) distribution grids, in line with the European environmental targets. To cope with the effects on grid voltage profiles during high generation and low demand periods, new solutions need to be establis...

  4. Low energy electron beams for industrial and environmental applications

    CERN Document Server

    Skarda, Vlad

    2017-01-01

    EuCARD-2 Workshop, 8-9 December 2016, Warsaw, Poland. Organizers: Science and Technology Facilities Council, UK CERN - The European Organization for Nuclear Research, Switzerland, Institute of Nuclear Chemistry and Technology, Poland, Fraunhofer Institute for Electron Beam and Plasma Technology, Germany, Warsaw University of Technology, Poland. An article presents short information about EuCARD-2 Workshop “Low energy electron beams for industrial and environmental applications”, which was held in December 2016 in Warsaw. Objectives, main topics and expected output of meeting are described. List of organizers is included.

  5. The application of recycled aluminum and plastics in environmental protection

    Directory of Open Access Journals (Sweden)

    G. Tepić

    2013-07-01

    Full Text Available Environmental protection is a serious problem facing the modern world. Precisely for this reason, in this work, the authors explore its different aspects. From the perspective of conservation of natural resources and energy savings, the replacement of primary materials through recycling is explored as a potential solution in the elementary processes related to the parasol production. Such parasols would be used in designing “urban forest” solutions, which significantly contribute to the protection of the planet from global warming, as well as the preservation of life and survival.

  6. Environmental application of aerial reconnaissance to search for open dumps

    Science.gov (United States)

    Getz, Thomas J.; Randolph, J. C.; Echelberger, Wayne F.

    1983-11-01

    Three approaches to using aerial photography are evaluated for searching for open dumps in the state of Indiana. Photography with hand-held cameras from a small airplane proved more effective and flexible than either photo-interpretation of existing air photos or subcontracting to a federal agency for new aerial photography. The rationale for our choice of aerial reconnaissance, other uses of low-level aerial surveillance, the utility of small-format camera aerial photography for environmental analysis, and methods used for locating open dumps are discussed.

  7. Nanoparticles: synthesis and applications in life science and environmental technology

    Science.gov (United States)

    Luong Nguyen, Hoang; Nguyen, Hoang Nam; Hai Nguyen, Hoang; Quynh Luu, Manh; Hieu Nguyen, Minh

    2015-03-01

    This work focuses on the synthesis, functionalization, and application of gold and silver nanoparticles, magnetic nanoparticles Fe3O4, combination of 4-ATP-coated silver nanoparticles and Fe3O4 nanoparticles. The synthesis methods such as chemical reduction, seeding, coprecipitation,and inverse microemulsion will be outlined. Silica- and amino-coated nanoparticles are suitable for several applications in biomedicine and the environment. The applications of the prepared nanoparticles for early detection of breast cancer cells, basal cell carcinoma, antibacterial test, arsenic removal from water, Herpes DNA separation, CD4+ cell separation and isolation of DNA of Hepatitis virus type B (HBV) and Epstein-Barr virus (EBV) are discussed. Finally, some promising perspectives will be pointed out. Invited talk at the 7th International Workshop on Advanced Materials Science and Nanotechnology IWAMSN2014, 2-6 November, 2014, Ha Long, Vietnam.

  8. Microbial flocculant and its application in environmental protection

    Institute of Scientific and Technical Information of China (English)

    1999-01-01

    The microbial flocculant is a kind of natural bio- polymer and has promising future to be used in the fermentation industry and wastewater treatment. It has been studied in details in many countries, such as U.S.A, Japan. This paper reviewed the development on microbial flocculant basic studies and applications, including flocculant-production microorganisms, chemical and components of microbial flocculants, flocculation mechanism of microbial flocculants, capability of microbial flocculants and influence factors, and culture conditions for flocculant production. The application cases of microbial flocculants were also discussed.

  9. The Application of Auto-Disturbance Rejection Control Optimized by Least Squares Support Vector Machines Method and Time-Frequency Representation in Voltage Source Converter-High Voltage Direct Current System.

    Directory of Open Access Journals (Sweden)

    Ying-Pei Liu

    Full Text Available In order to improve the performance of voltage source converter-high voltage direct current (VSC-HVDC system, we propose an improved auto-disturbance rejection control (ADRC method based on least squares support vector machines (LSSVM in the rectifier side. Firstly, we deduce the high frequency transient mathematical model of VSC-HVDC system. Then we investigate the ADRC and LSSVM principles. We ignore the tracking differentiator in the ADRC controller aiming to improve the system dynamic response speed. On this basis, we derive the mathematical model of ADRC controller optimized by LSSVM for direct current voltage loop. Finally we carry out simulations to verify the feasibility and effectiveness of our proposed control method. In addition, we employ the time-frequency representation methods, i.e., Wigner-Ville distribution (WVD and adaptive optimal kernel (AOK time-frequency representation, to demonstrate our proposed method performs better than the traditional method from the perspective of energy distribution in time and frequency plane.

  10. The Application of Auto-Disturbance Rejection Control Optimized by Least Squares Support Vector Machines Method and Time-Frequency Representation in Voltage Source Converter-High Voltage Direct Current System.

    Science.gov (United States)

    Liu, Ying-Pei; Liang, Hai-Ping; Gao, Zhong-Ke

    2015-01-01

    In order to improve the performance of voltage source converter-high voltage direct current (VSC-HVDC) system, we propose an improved auto-disturbance rejection control (ADRC) method based on least squares support vector machines (LSSVM) in the rectifier side. Firstly, we deduce the high frequency transient mathematical model of VSC-HVDC system. Then we investigate the ADRC and LSSVM principles. We ignore the tracking differentiator in the ADRC controller aiming to improve the system dynamic response speed. On this basis, we derive the mathematical model of ADRC controller optimized by LSSVM for direct current voltage loop. Finally we carry out simulations to verify the feasibility and effectiveness of our proposed control method. In addition, we employ the time-frequency representation methods, i.e., Wigner-Ville distribution (WVD) and adaptive optimal kernel (AOK) time-frequency representation, to demonstrate our proposed method performs better than the traditional method from the perspective of energy distribution in time and frequency plane.

  11. Application for review, Section 61, Environmental Bill of Rights

    Energy Technology Data Exchange (ETDEWEB)

    Grinspun, D. [Registered Nurses Association of Ontario, Toronto, ON (Canada); Forman, G. [Canadian Association of Physicians for the Environment, Toronto, ON (Canada); Hutton, A. [Muskoka Lakes Association, Port Carling, ON (Canada); Muter, M. [Georgian Bay Association, Toronto, ON (Canada); Stewart, K. [World Wildlife Fund Canada, Toronto, ON (Canada); Wilkins, H. [Sierra Legal Defence Fund, Toronto, ON (Canada)

    2006-10-11

    Health and environmental groups have filed a request with the Ontario Ministry of Environment and Ministry of Energy to review its government policies on transboundary smog, mercury emissions and climate change in light of the abandonment of plans to close all of the province's highly polluting coal-fired power plants by 2009. The groups have requested that the Ministries identify the measures that will be taken to eliminate the health, social and environmental impacts caused by this decision. The representatives of Ontario's registered nurses, physicians, community groups and environment groups want to know how the decision will affect Ontario's compliance with the terms of the Ozone Annex to the 1991 United States-Canada Air Quality Agreement, Ontario's compliance with the proposed Canada Wide Standard on Mercury, and efforts to combat climate change. Concerns that the government has weakened its position in dealing with the United States over transboundary smog were expressed. Smog, climate change and mercury pollution pose significant risks to the health of Ontarians. The original plan to replace coal-fired generation was the single largest greenhouse gas reduction initiative in Canada. It was argued that the abandonment of that plan represents a major challenge in meeting Kyoto targets. refs.

  12. Resilience and sustainability: Similarities and differences in environmental management applications.

    Science.gov (United States)

    Marchese, Dayton; Reynolds, Erin; Bates, Matthew E; Morgan, Heather; Clark, Susan Spierre; Linkov, Igor

    2017-09-25

    In recent years there have been many disparate uses of the terms sustainability and resilience, with some framing sustainability and resilience as the same concept, and others claiming them to be entirely different and unrelated. To investigate similarities, differences, and current management frameworks for increasing sustainability and resilience, a literature review was undertaken that focused on integrated use of sustainability and resilience in an environmental management context. Sustainability was defined through the triple bottom line of environmental, social and economic system considerations. Resilience was viewed as the ability of a system to prepare for threats, absorb impacts, recover and adapt following persistent stress or a disruptive event. Three generalized management frameworks for organizing sustainability and resilience were found to dominate the literature: (1) resilience as a component of sustainability, (2) sustainability as a component of resilience, and (3) resilience and sustainability as separate objectives. Implementations of these frameworks were found to have common goals of providing benefits to people and the environment under normal and extreme operating conditions, with the best examples building on similarities and minimizing conflicts between resilience and sustainability. Published by Elsevier B.V.

  13. 2nd European Conference on Geostatistics for Environmental Applications

    CERN Document Server

    Soares, Amílcar; Froidevaux, Roland

    1999-01-01

    The Second European Conference on Geostatistics for Environmental Ap­ plications took place in Valencia, November 18-20, 1998. Two years have past from the first meeting in Lisbon and the geostatistical community has kept active in the environmental field. In these days of congress inflation, we feel that continuity can only be achieved by ensuring quality in the papers. For this reason, all papers in the book have been reviewed by, at least, two referees, and care has been taken to ensure that the reviewer comments have been incorporated in the final version of the manuscript. We are thankful to the members of the scientific committee for their timely review of the scripts. All in all, there are three keynote papers from experts in soil science, climatology and ecology and 43 contributed papers providing a good indication of the status of geostatistics as applied in the environ­ mental field all over the world. We feel now confident that the geoENV conference series, seeded around a coffee table almost six...

  14. Total dose behavior of partially depleted SOI dynamic threshold voltage MOS (DTMOS) for very low supply voltage applications (0.6 - 1 V); Comportement en dose cumulee de transistors DTMOS (MOS a tension de seuil dynamique) en technologie SOI partiellement desertee pour applications a tres basse tension d'alimentation (0.6 - 1 V)

    Energy Technology Data Exchange (ETDEWEB)

    Ferlet-Cavrois, V.; Musseau, O.; Leray, J.L. [CEA Bruyeres le Chatel, DRIF, 91 (France); Faynot, O.; Raynaud, C.; Pelloie, J.L. [CEA Grenoble, Lab. d' Electronique et de Technologie de l' Informatique LETI, 38 (France)

    1999-07-01

    In this paper, we presented two DTMOS architectures processed with a partially depleted SOI technology. The first architecture, DTMOS without limiting transistor, is dedicated to ultra-low voltage applications, at 0.6 V. For 1V applications, the second architecture, DTMOS with limiting transistor, needs an additional transistor to limit the body-source diode current. The total dose irradiation of both DTMOS architectures induces no change of the drain current, but an increase of the body-source diode current. Total dose induced trapped charge in the buried oxide increases the body potential of the DTMOS transistor. It induces an increase of the current flow at the back interface of the silicon film. Irradiation of complex circuits using DTMOS transistors would lead to a degradation of the stand-by consumption. (authors)

  15. Micro- and nanofluidic devices for environmental and biomedical applications

    NARCIS (Netherlands)

    Gardeniers, Han; Berg, van den Albert

    2004-01-01

    During the last decade, an increasing amount of pocket-size chemistry equipment based on the so-called 'lab-on-a-chip'approach has become available. Besides the popular application in the analysis of biological macromolecules, such chips in combination with portable electronic equipment are applicab

  16. Micro and nanofluidic devices for environmental and biomedical applications

    NARCIS (Netherlands)

    Gardeniers, Johannes G.E.; van den Berg, Albert

    2004-01-01

    During the last decade, an increasing amount of pocket-size chemistry equipment based on the so-called 'lab-on-a-chip'approach has become available. Besides the popular application in the analysis of biological macromolecules, such chips in combination with portable electronic equipment are

  17. Characterization of RPC operation with new environmental friendly mixtures for LHC application and beyond

    Science.gov (United States)

    Guida, R.; Capeans, M.; Mandelli, B.

    2016-07-01

    The large muon trigger systems based on Resistive Plate Chambers (RPC) at the LHC experiments are currently operated with R134a based mixture. Unfortunately R134a is considered a greenhouse gas with high impact on the enviroment and therefore will be subject to regulations aiming in strongly reducing the available quantity on the market. The immediat effects might be instability on the price and incertitude in the product availability. Alternative gases (HFO-1234yf and HFO-1234ze) have been already identified by industry for specific applications as replacement of R134a. Moreover, HFCs similar to the R134a but with lower global warming potential (GWP) are already available (HFC-245fa, HFC-32, HFC-152a). The present contribution describes the results obtained with RPCs operated with new enviromemtal friendly gases. A particular attention has been addressed to the possibility of maintening the current operation conditions (i.e. currently used applied voltage and front-end electronics) in order to be able to use a new mixture for RPC systems even where the common infrastructure (i.e. high voltage and detector components) cannot be replaced for operation at higher applied voltages.

  18. Automatic voltage imbalance detector

    Science.gov (United States)

    Bobbett, Ronald E.; McCormick, J. Byron; Kerwin, William J.

    1984-01-01

    A device for indicating and preventing damage to voltage cells such as galvanic cells and fuel cells connected in series by detecting sequential voltages and comparing these voltages to adjacent voltage cells. The device is implemented by using operational amplifiers and switching circuitry is provided by transistors. The device can be utilized in battery powered electric vehicles to prevent galvanic cell damage and also in series connected fuel cells to prevent fuel cell damage.

  19. Mixed voltage VLSI design

    Science.gov (United States)

    Panwar, Ramesh; Rennels, David; Alkalaj, Leon

    1993-01-01

    A technique for minimizing the power dissipated in a Very Large Scale Integration (VLSI) chip by lowering the operating voltage without any significant penalty in the chip throughput even though low voltage operation results in slower circuits. Since the overall throughput of a VLSI chip depends on the speed of the critical path(s) in the chip, it may be possible to sustain the throughput rates attained at higher voltages by operating the circuits in the critical path(s) with a high voltage while operating the other circuits with a lower voltage to minimize the power dissipation. The interface between the gates which operate at different voltages is crucial for low power dissipation since the interface may possibly have high static current dissipation thus negating the gains of the low voltage operation. The design of a voltage level translator which does the interface between the low voltage and high voltage circuits without any significant static dissipation is presented. Then, the results of the mixed voltage design using a greedy algorithm on three chips for various operating voltages are presented.

  20. Novel method for hit-position reconstruction using voltage signals in plastic scintillators and its application to Positron Emission Tomography

    CERN Document Server

    Raczynski, L; Kowalski, P; Wislicki, W; Bednarski, T; Bialas, P; Czerwinski, E; Kaplon, L; Kochanowski, A; Korcyl, G; Kowal, J; Kozik, T; Krzemien, W; Kubicz, E; Molenda, M; Moskal, I; Niedzwiecki, Sz; Palka, M; Pawlik-Niedzwiecka, M; Rudy, Z; Salabura, P; Sharma, N G; Silarski, M; Slomski, A; Smyrski, J; Strzelecki, A; Wieczorek, A; Zielinski, M; Zon, N

    2014-01-01

    Currently inorganic scintillator detectors are used in all commercial Time of Flight Positron Emission Tomograph (TOF-PET) devices. The J-PET collaboration investigates a possibility of construction of a PET scanner from plastic scintillators which would allow for single bed imaging of the whole human body. This paper describes a novel method of hit-position reconstruction based on sampled signals and an example of an application of the method for a single module with a 30 cm long plastic strip, read out on both ends by Hamamatsu R4998 photomultipliers. The sampling scheme to generate a vector with samples of a PET event waveform with respect to four user-defined amplitudes is introduced. The experimental setup provides irradiation of a chosen position in the plastic scintillator strip with an annihilation gamma quanta of energy 511~keV. The statistical test for a multivariate normal (MVN) distribution of measured vectors at a given position is developed, and it is shown that signals sampled at four threshold...

  1. Portable High Voltage Impulse Generator

    Directory of Open Access Journals (Sweden)

    S. Gómez

    2011-07-01

    Full Text Available This paper presents a portable high voltage impulse generator which was designed and built with insulation up to 20 kV. This design was based on previous work in which simulation software for standard waves was developed. Commercial components and low-cost components were used in this work; however, these particular elements are not generally used for high voltage applications. The impulse generators used in industry and laboratories are usually expensive; they are built to withstand extra high voltage and they are big, making them impossible to transport. The proposed generator is portable, thereby allowing tests to be made on devices that cannot be moved from their location. The results obtained with the proposed impulse generator were satisfactory in terms of time and waveforms compared to other commercial impulse generators and the standard impulse wave simulator.

  2. [Application of microfluidics in aquatic environmental pollution analysis].

    Science.gov (United States)

    Wang, Hu; Wei, Jun-Feng; Zheng, Guo-Xia

    2014-04-01

    Recently, a new type of chip technology, microfluidics, has received global attention for its rapid analysis speed, low reagent consumption, small size and simple operation, etc. Based on a micro-channel network and supported by a Micro-Electro-Mechanic System (MEMS), this technology integrates all the functions of a laboratory into one small piece of chip, which is called "lab on the chip". This paper presented a brief introduction about microfluidics and its representative developments. Future prospects in the aspects of instrument miniaturization, system integration, chip materials, and detection techniques, as well as the implementation of microfluidics in aquatic environmental pollutant analysis were thoroughly discussed. Some problems faced now were put forward. With the rapid progress in the microfluidics, a universal low-cost microchip capable of high speed multi-channel detection and integrated with many kinds of detection methods would be the research focus in the future.

  3. Indispensable role of biochar-inherent mineral constituents in its environmental applications: A review.

    Science.gov (United States)

    Xu, Xiaoyun; Zhao, Yinghao; Sima, Jingke; Zhao, Ling; Mašek, Ondřej; Cao, Xinde

    2017-10-01

    Biochar typically consists of both carbon and mineral fractions, and the carbon fraction has been generally considered to determine its properties and applications. Recently, an increasing body of research has demonstrated that mineral components inherent in biochar, such as alkali or alkaline earth metals in the form of carbonates, phosphates, or oxides, could also influence the properties and thus the applications. The review articles published thus far have mainly focused on multiple environmental and agronomic applications of biochar, including carbon sequestration, soil improvement, environmental remediation, etc. This review aims to highlight the indispensable role of the mineral fraction of biochar in these different applications, especially in environmental applications. Specifically, it provides a critical review of current research findings related to the mineral composition of biochar and the effect of the mineral fraction on the physicochemical properties, contaminant sorption, carbon retention and stability, and nutrient bioavailability of biochar. Furthermore, the role of minerals in the emerging applications of biochar, as a precursor for fuel cells, supercapacitors, and photoactive components, is also summarized. Overall, inherent minerals should be fully considered while determining the most appropriate application for any given biochar. A thorough understanding of the role of biochar-bound minerals in different applications will also allow the design or selection of the most suitable biochar for specific applications based on the consideration of feedstock composition, production parameters, and post-treatment. Copyright © 2017 Elsevier Ltd. All rights reserved.

  4. The application of disperse systems in environmental engineering

    Directory of Open Access Journals (Sweden)

    Povrenović Dragan S.

    2003-01-01

    Full Text Available This paper presents the experimental results of spouted and spout-fluid bed investigations and their application in waste treatment in the food industry and the fluid-mechanical investigations of a co-current spouted bed with the aim of its application in water treatment, with immobilized microorganism systems. The Investigated systems were applied in animal blood and plasma drying, as a possible ecological solution in the meat-processing industry and brewery yeast drying. These waste materials are very dangerous pollutants for natural recipients. The concept of a co-current spouted bed as a basis for microbiological water treatment in the nitrification process of ammonium nitrogen is presented in the second part of this paper.

  5. Virtual environmental applications for buried waste characterization technology evaluation report

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-05-01

    The project, Virtual Environment Applications for Buried Waste Characterization, was initiated in the Buried Waste Integrated Demonstration Program in fiscal year 1994. This project is a research and development effort that supports the remediation of buried waste by identifying and examining the issues, needs, and feasibility of creating virtual environments using available characterization and other data. This document describes the progress and results from this project during the past year.

  6. Environmental application of nanotechnology: air, soil, and water.

    Science.gov (United States)

    Ibrahim, Rusul Khaleel; Hayyan, Maan; AlSaadi, Mohammed Abdulhakim; Hayyan, Adeeb; Ibrahim, Shaliza

    2016-07-01

    Global deterioration of water, soil, and atmosphere by the release of toxic chemicals from the ongoing anthropogenic activities is becoming a serious problem throughout the world. This poses numerous issues relevant to ecosystem and human health that intensify the application challenges of conventional treatment technologies. Therefore, this review sheds the light on the recent progresses in nanotechnology and its vital role to encompass the imperative demand to monitor and treat the emerging hazardous wastes with lower cost, less energy, as well as higher efficiency. Essentially, the key aspects of this account are to briefly outline the advantages of nanotechnology over conventional treatment technologies and to relevantly highlight the treatment applications of some nanomaterials (e.g., carbon-based nanoparticles, antibacterial nanoparticles, and metal oxide nanoparticles) in the following environments: (1) air (treatment of greenhouse gases, volatile organic compounds, and bioaerosols via adsorption, photocatalytic degradation, thermal decomposition, and air filtration processes), (2) soil (application of nanomaterials as amendment agents for phytoremediation processes and utilization of stabilizers to enhance their performance), and (3) water (removal of organic pollutants, heavy metals, pathogens through adsorption, membrane processes, photocatalysis, and disinfection processes).

  7. Voltage modulation of propagating spin waves in Fe

    Energy Technology Data Exchange (ETDEWEB)

    Nawaoka, Kohei; Shiota, Yoichi; Miwa, Shinji; Tamura, Eiiti [Graduate School of Engineering Science, Osaka University, Toyonaka, Osaka 560-8531 (Japan); CREST, Japan Science Technology, Kawaguchi, Saitama 332-0012 (Japan); Tomita, Hiroyuki; Mizuochi, Norikazu; Shinjo, Teruya [Graduate School of Engineering Science, Osaka University, Toyonaka, Osaka 560-8531 (Japan); Suzuki, Yoshishige, E-mail: suzuki-y@mp.es.osaka-u.ac.jp [Graduate School of Engineering Science, Osaka University, Toyonaka, Osaka 560-8531 (Japan); CREST, Japan Science Technology, Kawaguchi, Saitama 332-0012 (Japan); Display and Semiconductor Physics Department, Korea University, Sejong 339-700 (Korea, Republic of)

    2015-05-07

    The effect of a voltage application on propagating spin waves in single-crystalline 5 nm-Fe layer was investigated. Two micro-sized antennas were employed to excite and detect the propagating spin waves. The voltage effect was characterized using AC lock-in technique. As a result, the resonant field of the magnetostatic surface wave in the Fe was clearly modulated by the voltage application. The modulation is attributed to the voltage induced magnetic anisotropy change in ferromagnetic metals.

  8. A New Control Method of a Resonant Switched-Capacitor Converter and the Application for Balancing of the Split DC Voltages in a Multilevel Inverter

    Science.gov (United States)

    Sano, Kenichiro; Fujita, Hideaki

    This paper proposes a new voltage-balancing circuit for the split dc voltages in a diode-clamped five-level inverter. The proposed circuit is based on a resonant switched-capacitor converter (RSCC), which consists of two half-bridge inverters, a resonant inductor and a resonant capacitor. A new phase-shift control of the RSCC is proposed to improve voltage balancing performance. Theoretical analysis reveals the rating of the RSCC and stored energy in the resonant inductor. Experimental results confirm the reduction of the inductor to one tenth in volume as compared to a conventional voltage-balancing circuit based on buck-boost topology. Moreover, the proposed phase-shift control has demonstrated that it is possible to eliminate the voltage deviation between the dc capacitors.

  9. DTMOS-Based 0.4V Ultra Low-Voltage Low-Power VDTA Design and Its Application to EEG Data Processing

    Directory of Open Access Journals (Sweden)

    A. Uygur

    2013-06-01

    Full Text Available In this paper, an ultra low-voltage, ultra low-power voltage differencing transconductance amplifier (VDTA is proposed. DTMOS (Dynamic Threshold Voltage MOS transistors are employed in the design to effectively use the ultra low supply voltage. The proposed VDTA is composed of two operational transconductance amplifiers operating in the subthreshold region. Using TSMC 0.18µm process technology parameters with symmetric ±0.2V sup¬ply voltage, the total power consumption of the VDTA block is found as just 5.96 nW when the transconductances have 3.3 kHz, 3 dB bandwidth. The proposed VDTA circuit is then used in a fourth-order double-tuned band-pass filter for processing real EEG data measurements. The filter achieves close to 64 dB dynamic range at 2% THD with a total power consumption of 12.7 nW.

  10. Speciation analysis of {sup 129}I and its applications in environmental research

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, L.Y. [Technical Univ. of Denmark, Risoe, Roskilde (Denmark). Center for Nuclear Technologies; Hou, X.L. [Technical Univ. of Denmark, Risoe, Roskilde (Denmark). Center for Nuclear Technologies; Chinese Academy of Sciences, Xi' an (China). Xi' an AMS Center

    2013-10-01

    {sup 129}I, a long-lived radionuclide, is important in view of geological repository of nuclear waste, and environmental tracing applications related to diverse natural processes of iodine. The environmental behaviors and bioavailability of {sup 129}I are highly related to its species. A number of methods have been reported for speciation analysis of {sup 129}I in a variety of environmental samples. These methods have been applied in many researches, including conversion processes of iodine species in marine and terrestrial systems, migration and retention of iodine in soil and sediment, geochemical cycling of iodine, as well as studies on atmospheric chemistry of iodine. This article aims to review these methods and their applications in environmental research. (orig.)

  11. Spectroscopic studies of uranium species for environmental decontamination applications

    Science.gov (United States)

    Eng, Charlotte

    After the Cold War, Department of Energy began to concentrate its efforts on cleanup of former nuclear material processing facilities, especially uranium-contaminated groundwater and soil. This research aims to study uranium association to both organic and inorganic compounds found in the contaminated environment in the hopes that the information gathered can be applied to the development and optimization of cost-effective remediation techniques. Spectroscopic and electrochemical methods will be employed to examine the behavior of uranium in given conditions to further our understanding of its impact on the environment. Uranium found in groundwater and soil bind with various ligands, especially organic ligands present in the environment due to natural sources (e.g. metabolic by-products or degradation of plants and animals) or man-made sources (e.g. chelating agents used in operating or cleanup of uranium processing facilities). We selected reasonable analogs of naturally occurring matter and studied their structure, chemical and electrochemical behavior and found that the structure of uranyl complexes depends heavily on the nature of the ligand and environmental factors such as pH. Association of uranium-organic complexes with anaerobic bacteria, Clostridium sp. was studied to establish if the bacteria can effectively bioreduce uranium while going through normal bacterial activity. It was found that the nature of the organic ligand affected the bioavailability and toxicity of the uranium on the bacteria. In addition, we have found that the type of iron corrosion products and uranyl species present on the surface of corroded steel depended on various environmental factors, which subsequently affected the removal rate of uranium by a citric acid/hydrogen peroxide/deionized water cleaning process. The method was found to remove uranium from only the topmost corrosion layers and residual uranium could be found (a) deeper in the corrosion layers where it is occluded by

  12. Application of High-Voltage Presence Indication System in Gas Insulated Metal-Enclosed Switchgear%高压带电显示装置在GIS中的应用

    Institute of Scientific and Technical Information of China (English)

    高二平

    2016-01-01

    介绍了高压带电显示装置在SF6气体绝缘金属封闭式组合电器(GIS)上的应用,阐述了其工作原理及在GIS上实现的结构型式,并对比了高压带电显示装置的IEC标准、国家标准及行业标准的差异,总结了高压带电显示装置在GIS实际应用过程中出现的问题及影响因素,为GIS上使用高压带电显示装置提供了参考。%Introduction was made to the application of high-voltage presence indication device in SF6 gas insulated metal-enclosed switchgear (GIS). This paper expounded on its working principle and the realized structural style in GIS, compared the difference among the relevant IEC, GB and DL standards of high-voltage presence indication device and summarized the arisen problems and influence factors in the practical application process of GIS in high-voltage presence indication device, to provide references for the application of high-voltage presence indication device in GIS.

  13. Development and application of the lux gene for environmental bioremediation

    Energy Technology Data Exchange (ETDEWEB)

    Burlage, R.S.; Yang, Z. [Oak Ridge National Lab., TN (United States). Environmental Sciences Div.; Palmer, R.J. [Univ. of Tennessee, Knoxville, TN (United States). Center for Environmental Biotechnology; Khang, Y. [Yeungnam Univ., Kyongsan (Korea, Republic of)

    1996-09-01

    Bioremediation is the use of living systems, usually microorganisms, to treat a quantity of soil or water for the presence of hazardous wastes. Bioremediation has many advantages over other remediation approaches, including cost savings, versatility, and the ability to treat the wastes in situ. In order to study the processes of microbial bioremediation, the authors have constructed bacterial strains that incorporate genetically engineered bioreporter genes. These bioreporter genes allow the bacteria to be detected during in situ processes, as manifested by their ability to bioluminescence or to fluoresce. This bioreporter microorganisms are described, along with the technology for detecting them and the projects which are benefiting from their application.

  14. Tuning CNT Properties for Metal-Free Environmental Catalytic Applications

    Directory of Open Access Journals (Sweden)

    Raquel P. Rocha

    2016-06-01

    Full Text Available The application of carbon nanotubes (CNTs as metal-free catalysts is a novel approach for heterogeneous liquid phase catalytic systems. Textural and chemical modifications by liquid/gas phase or mechanical treatments, as well as solid state reactions, were successfully applied to obtain carbon nanotubes with different surface functionalities. Oxygen, nitrogen, and sulfur are the most common heteroatoms introduced on the carbon surface. This short-review highlights different routes used to develop metal-free carbon nanotube catalysts with enhanced properties for Advanced Oxidation Processes.

  15. Development and application of the lux gene for environmental bioremediation

    Science.gov (United States)

    Burlage, Robert S.; Yang, Zamin; Palmer, Robert J., Jr.; Sayler, Gary S.; Khang, Yongho

    1996-11-01

    Bioremediation is the use of living systems, usually microorganisms, to treat a quantity of soil or water for the presence of hazardous wastes. Bioremediation has many advantages over other remediation approaches, including cost savings, versatility, and the ability to treat the wastes in situ. In order to study the processes of microbial bioremediation, we have constructed bacterial strains that incorporate genetically engineered bioreporter genes. These bioreporter genes allow the bacteria to be detected during in situ processes, as manifested by their ability to bioluminesce or to fluoresce. This bioreporter microorganisms are described, along with the technology for detecting them and the projects which are benefiting from their application.

  16. Low-Power, Self-Rectifying, and Forming-Free Memristor with an Asymmetric Programing Voltage for a High-Density Crossbar Application.

    Science.gov (United States)

    Kim, Kyung Min; Zhang, Jiaming; Graves, Catherine; Yang, J Joshua; Choi, Byung Joon; Hwang, Cheol Seong; Li, Zhiyong; Williams, R Stanley

    2016-11-09

    A Pt/NbOx/TiOy/NbOx/TiN stack integrated on a 30 nm contact via shows a programming current as low as 10 nA and 1 pA for the set and reset switching, respectively, and a self-rectifying ratio as high as ∼10(5), which are suitable characteristics for low-power memristor applications. It also shows a forming-free characteristic. A charge-trap-associated switching model is proposed to account for this self-rectifying memrisive behavior. In addition, an asymmetric voltage scheme (AVS) to decrease the write power consumption by utilizing this self-rectifying memristor is also described. When the device is used in a 1000 × 1000 crossbar array with the AVS, the programming power can be decreased to 8.0% of the power consumption of a conventional biasing scheme. If the AVS is combined with a nonlinear selector, a power consumption reduction to 0.31% of the reference value is possible.

  17. Lithium-cyclo-difluoromethane-1,1-bis(sulfonyl)imide as a stabilizing electrolyte additive for improved high voltage applications in lithium-ion batteries.

    Science.gov (United States)

    Murmann, Patrick; Streipert, Benjamin; Kloepsch, Richard; Ignatiev, Nikolai; Sartori, Peter; Winter, Martin; Cekic-Laskovic, Isidora

    2015-04-14

    Lithium-cyclo-difluoromethane-1,1-bis(sulfonyl)imide (LiDMSI) was evaluated as an electrolyte additive in lithium-ion batteries for improved high voltage applications. Cycling the cathode at high potentials leads to the electrochemical oxidation of the salt to form a cathode electrolyte interphase (CEI) layer on the cathode surface. With the addition of 2 wt% of LiDMSI to the 1 M LiPF6 in 1 : 1 (by wt) EC : DEC electrolyte, the capacity retention and the Coulombic efficiency in LiNi1/3Co1/3Mn1/3O2/Li-half-cells as well as in LiNi1/3Co1/3Mn1/3O2/graphite-full-cells were improved. The cycling results point out the less over-potential and resistance at the cathode/electrolyte interface. These improvements are studied by SEM, EIS and XPS techniques.

  18. Optoelectronic methods in potential application in monitoring of environmental conditions

    Science.gov (United States)

    Mularczyk-Oliwa, Monika; Bombalska, Aneta; Kwaśny, Mirosław; Kopczyński, Krzysztof; Włodarski, Maksymilian; Kaliszewski, Miron; Kostecki, Jerzy

    2016-12-01

    Allergic rhinitis, also known as hay fever is a type of inflammation which occurs when the immune system overreacts to allergens in the air. It became the most common disease among people. It became important to monitor air content for the presence of a particular type of allergen. For the purposes of environmental monitoring there is a need to widen the group of traditional methods of identification of pollen for faster and more accurate research systems. The aim of the work was the characterization and classification of certain types of plant pollens by using laser optical methods, which were supported by the chemmometrics. Several species of pollen were examined, for which a database of spectral characteristics was created, using LIF, Raman scattering and FTIR methods. Spectral database contains characteristics of both common allergens and pollen of minor importance. Based on registered spectra, statistical analysis was made, which allows the classification of the tested pollen species. For the study of the emission spectra Nd:YAG laser was used with the fourth harmonic generation (266 nm) and GaN diode laser (375 nm). For Raman scattering spectra spectrometer Nicolet IS-50 with a excitation wavelength of 1064 nm was used. The FTIR spectra, recorded in the mid infrared1 range (4000-650 cm-1) were collected with use of transmission mode (KBr pellet), ATR and DRIFT.

  19. Application of algae-biosensor for environmental monitoring.

    Science.gov (United States)

    Umar, Lazuardi; Alexander, Frank A; Wiest, Joachim

    2015-01-01

    Environmental problems including water and air pollution, over fertilization, insufficient wastewater treatment and even ecological disaster are receiving greater attention in the technical and scientific area. In this paper, a method for water quality monitoring using living green algae (Chlorella Kessleri) with the help of the intelligent mobile lab (IMOLA) is presented. This measurement used two IMOLA systems for measurement and reference simultaneously to verify changes due to pollution inside the measurement system. The IMOLA includes light emitting diodes to stimulate photosynthesis of the living algae immobilized on a biochip containing a dissolved oxygen microsensor. A fluid system is used to transport algae culture medium in a stop and go mode; 600s ON, 300s OFF, while the oxygen concentration of the water probe is measured. When the pump stops, the increase in dissolved oxygen concentration due to photosynthesis is detected. In case of a pollutant being transported toward the algae, this can be detected by monitoring the photosynthetic activity. Monitoring pollution is shown by adding emulsion of 0,5mL of Indonesian crude palm oil and 10mL algae medium to the water probe in the biosensor.

  20. Advances to Dynamic Mechanical Analysis: High Frequencies and Environmental Applications

    Science.gov (United States)

    Foreman, Jonathon

    2002-03-01

    In dynamic mechanical analysis (DMA) the sample is deformed and released sinusoidally providing information about the modulus and damping behaviors with respect to temperature, time, oscillation frequency and amplitude of motion. It offers exceptional sensitivity to glass transitions and secondary relaxations. Recent developments have increased the frequency range up to 1000 Hz, which allow properties measurements under actual end-use conditions. Furthermore high frequencies enhance the ability to determine the kinetics of viscoelastic relaxations. Another recent development allows DMA measurements while samples are immersed in fluids or enveloped in gases. Most significant is the ability to alter the furnace control parameters to account for the thermal properties of the environment used. This configuration allows temperature-controlled measurements (both heating and isothermal profiles) on a wide range of sample shapes and sizes. Environmental DMA is easier to interpret than standard DMA (in air or inert gas) on preconditioned samples because such samples often lose the conditioning solvent or gas during the measurement. easy.com/dma_apps.asp>Examples will show real-time property changes from the interaction of unconditioned materials with conditioning environments and experiments on pre-conditioned materials that are heated while immersed in conditioning environments. -------------------------------------------------------------

  1. THE APPLICATION OF THE METHOD ENVIRONMENTAL VALUE AT RISK (EVaR IN ENVIRONMENTAL ECONOMY

    Directory of Open Access Journals (Sweden)

    Gabriela Cornelia I. PICIU

    2014-04-01

    Full Text Available Taking into account the fact that the methodology Value at Risk or the method VaR, which is omnipresent in investment banking and which has lately become a standard in the procedure of evaluating risks for any category of economic activities, we shall use a technique that is compatible with the VaR-market, called Environmental Value at Risk or EvaR. While the VaR- market uses a level of trust of 95%, the EvaR uses a set of levels up to 99,999%. Thus, we shall try to analyze the variables of the method EVaR, and the way in which this model can be applied as a risk of the lack (rarity of petroleum. This risk is not only analyzed as a unique risk of growing the prices, but also as an uncertainty risk on volatile markets, in which the price and the volatility are the main variables used by the function EVaR.

  2. THE APPLICATION OF THE METHOD ENVIRONMENTAL VALUE AT RISK (EVaR IN ENVIRONMENTAL ECONOMY

    Directory of Open Access Journals (Sweden)

    Gabriela Cornelia I. PICIU

    2014-04-01

    Full Text Available Taking into account the fact that the methodology Value at Risk or the method VaR, which is omnipresent in investment banking and which has lately become a standard in the procedure of evaluating risks for any category of economic activities, we shall use a technique that is compatible with the VaR-market, called Environmental Value at Risk or EvaR. While the VaR- market uses a level of trust of 95%, the EvaR uses a set of levels up to 99,999%. Thus, we shall try to analyze the variables of the method EVaR, and the way in which this model can be applied as a risk of the lack (rarity of petroleum. This risk is not only analyzed as a unique risk of growing the prices, but also as an uncertainty risk on volatile markets, in which the price and the volatility are the main variables used by the function EVaR.

  3. Soft Computing Models in Industrial and Environmental Applications

    CERN Document Server

    Abraham, Ajith; Corchado, Emilio; 7th International Conference, SOCO’12

    2013-01-01

    This volume of Advances in Intelligent and Soft Computing contains accepted papers presented at SOCO 2012, held in the beautiful and historic city of Ostrava (Czech Republic), in September 2012.   Soft computing represents a collection or set of computational techniques in machine learning, computer science and some engineering disciplines, which investigate, simulate, and analyze very complex issues and phenomena.   After a through peer-review process, the SOCO 2012 International Program Committee selected 75 papers which are published in these conference proceedings, and represents an acceptance rate of 38%. In this relevant edition a special emphasis was put on the organization of special sessions. Three special sessions were organized related to relevant topics as: Soft computing models for Control Theory & Applications in Electrical Engineering, Soft computing models for biomedical signals and data processing and Advanced Soft Computing Methods in Computer Vision and Data Processing.   The selecti...

  4. Novel, convenient, and nonpersistent radiotracer for environmental and energy applications

    Energy Technology Data Exchange (ETDEWEB)

    Grant, P.M.

    1984-03-12

    A newly-available radioisotopic system, /sup 172/Hf-/sup 172/Lu, has excellent potential for tracer applications in which nuclear data acquisition must be accomplished in real time. The 6.7-day half-life of /sup 172/Lu is sufficient for a large fraction of tracer experiments, and should allow the direct incorporation of /sup 172/Lu into tests that have traditionally utilized much longer-lived radionuclides. Since /sup 172/Lu is the daughter component of a radioisotope generator, however, its effective shelf-life is determined by the half-life of its 1.9-year /sup 172/Hf parent. Consequently, the frequency of isotope procurement need not be any more extensive than investigators would normally be accustomed to. Discussion relevant to isotope production, generator operation, and nuclide acquisition is presented in this paper.

  5. Development of Voltage Sag Compensator and UPS using a Flywheel Induction Motor and an Engine Generator

    Science.gov (United States)

    Kato, Shuhei; Takaku, Taku; Sumitani, Hideo; Shimada, Ryuichi

    Flywheel energy storage systems are focused as uninterruptible power supplies (UPS) from the viewpoint of environmental friendliness and high durability performance. Using a low-speed and heavy flywheel, and a low-cost squirrel-cage induction motor/generator, two applications are proposed; 1) 11kW voltage sag compensator using a capacitor self-excited induction generator without semiconductor converters; 2) UPS composed of the flywheel system and an engine generator. From some experimental results, an ideal voltage sag compensator and UPS are realized by the low-technology flywheel system.

  6. 稳压装置在引信保险机构中的应用%Application of Stabilized Voltage Device in Fuze Insurance Mechanism

    Institute of Scientific and Technical Information of China (English)

    金浩; 曲家惠; 岳明凯

    2011-01-01

    对于火箭弹来说,引信解除保险可利用的环境力极其有限,其中,利用燃气动力作为引信第二环境力解除保险是目前众多科研工作者研究的一项重要内容。然而,对于不同的火箭弹,其火箭发动机燃烧室可提供的燃气压力是不同的,因此,燃气动力解除保险执行机构的设计也必须针对不同弹种进行,其通用化程度很低。本文设计了一种稳压装置并制作出该装置实验模型样机,通过MAF风洞实验证明了该方案的可行性,为众多科研工作者提供了一个可行的思路。%For rocket projectile, it is extremely limited to remove the fuze insurance by means of environmental force. In which, to use gas power as second environmental force of fuze to remove the insurance is an important research content that the numerous researchers are studied in it. However, for different rocket projectile, the fuel gas pressure provided by its rocket engine combustion chamber is different, accordingly the design of insurance actuator by gas dynamic remove must also be designed to aim at different species, and the degree of its generalization is very low. This paper proposed that it designed a voltage stabilizer, and made the device of experimental MAF prototype. Through the test of experimental model wind tunnel, it validated the feasibility of this scheme. It provides a feasible thinking for scientific research.

  7. Application of a value-based equivalency method to assess environmental damage compensation under the European Environmental Liability Directive.

    Science.gov (United States)

    Martin-Ortega, Julia; Brouwer, Roy; Aiking, Harry

    2011-06-01

    The Environmental Liability Directive (ELD) establishes a framework of liability based on the 'polluter-pays' principle to prevent and remedy environmental damage. The ELD requires the testing of appropriate equivalency methods to assess the scale of compensatory measures needed to offset damage. The aim of this paper is to contribute to fill the existing knowledge gap on the application of the value equivalency approach for damage compensation in this context. We analyze the toxic spill damaging the Doñana National Park (Spain) in 1998. The welfare losses associated with the resource damage are estimated using non-market valuation and compared to the value of the compensatory measures taken after the accident. Our results show that the in-kind compensation may have been insufficient to offset the welfare losses. We conclude that a more comprehensive knowledge of the human welfare effects caused by environmental damage is of substantial importance to determine compensatory remediation, as insufficient information in this respect can lead to erroneous decisions causing loss to society. Copyright © 2010 Elsevier Ltd. All rights reserved.

  8. Cerium: catalytic properties, technological and environmental applications; Cerio: propriedades cataliticas, aplicacoes tecnologicas e ambientais

    Energy Technology Data Exchange (ETDEWEB)

    Martins, Tereza S. [Universidade de Sao Paulo (USP), SP (Brazil). Inst. de Fisica; Hewer, Thiago L.R. [Universidade de Sao Paulo (USP), SP (Brazil). Inst. de Quimica; Freire, Renato S. [Universidade de Sao Paulo (USP), Cubatao (Brazil). Centro de Capacitacao e Pesquisa em Meio Ambiente]. E-mail: tmartins@if.usp.br

    2007-07-01

    Cerium based-compounds have great importance in a wide range of technological applications, such as: fuel cell devices development; metallurgic processes, petroleum refining; glass and ceramic production. Recently, its catalytic properties have been also explored for environmental applications, especially those to prevent or to control atmospheric and water pollution. Subjects covered in this work include a brief description of the fundaments of cerium catalytic properties and some relevant technological applications. Special attention is given to its photo catalytic activity and its ability to degrade pollutants. Recent results and future prospect about these applications are also evaluated. (author)

  9. Chitosan derivatives obtained by chemical modifications for biomedical and environmental applications.

    Science.gov (United States)

    Alves, N M; Mano, J F

    2008-12-01

    Chitosan is a natural based polymer, obtained by alkaline deacetylation of chitin, which presents excellent biological properties such as biodegradability and immunological, antibacterial and wound-healing activity. Recently, there has been a growing interest in the chemical modification of chitosan in order to improve its solubility and widen its applications. The main chemical modifications of chitosan that have been proposed in the literature are reviewed in this paper. Moreover, these chemical modifications lead to a wide range of derivatives with a broad range of applications. Recent and relevant examples of the distinct applications, with particular emphasis on tissue engineering, drug delivery and environmental applications, are presented.

  10. Spintronic microfluidic platform for biomedical and environmental applications

    Science.gov (United States)

    Cardoso, F. A.; Martins, V. C.; Fonseca, L. P.; Germano, J.; Sousa, L. A.; Piedade, M. S.; Freitas, P. P.

    2010-09-01

    Faster, more sensitive and easy to operate biosensing devices still are a need at important areas such as biomedical diagnostics, food control and environmental monitoring. Recently, spintronic-devices have emerged as a promising alternative to the existent technologies [1-3]. A number of advantages, namely high sensitivity, easy integration, miniaturization, scalability, robustness and low cost make these devices potentially capable of responding to the existent technological need. In parallel, the field of microfluidics has shown great advances [4]. Microfluidic systems allow the analysis of small sample volumes (from micro- down to pico-liters), often by automate sample processing with the ability to integrate several steps into a single device (analyte amplification, concentration, separation and/or labeling), all in a reduced assay time (minutes to hours) and affordable cost. The merging of these two technologies, magnetoresistive biochips and microfluidics, will enable the development of highly competitive devices. This work reports the integration of a magnetoresistive biochip with a microfluidic system inside a portable and autonomous electronic platform aiming for a fully integrated device. A microfluidic structure fabricated in polydimethylsiloxane with dimensions of W: 0.5mm, H: 0.1mm, L: 10mm, associated to a mechanical system to align and seal the channel by pressure is presented (Fig. 1) [5]. The goal is to perform sample loading and transportation over the chip and simultaneously control the stringency and uniformity of the wash-out process. The biochip output is acquired by an electronic microsystem incorporating the circuitry to control, address and read-out the 30 spin-valve sensors sequentially (Fig. 1) [2]. This platform is being applied to the detection of water-borne microbial pathogens (e.g. Salmonella and Escherichia coli) and genetic diseases diagnosis (e.g. cystic fibrosis) through DNA hybridization assays. Open chamber measurements were

  11. Application of Autonomous Smart Inverter Volt-VAR Function for Voltage Reduction Energy Savings and Power Quality in Electric Distribution Systems: Preprint

    Energy Technology Data Exchange (ETDEWEB)

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

    2017-05-01

    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 smart inverter densities.

  12. Development of mobile electron beam plant for environmental applications

    Science.gov (United States)

    Han, Bumsoo; Kim, Jinkyu; Kang, Wongu; Choi, Jang Seung; Jeong, Kwang-Young

    2016-07-01

    Due to the necessity of pilot scale test facility for continuous treatment of wastewater and gases on site, a mobile electron beam irradiation system mounted on a trailer has developed. This mobile electron beam irradiation system is designed for the individual field application with self-shielded structure of steel plate and lead block which will satisfy the required safety figures of International Commission on Radiological Protection (ICRP). Shielding of a mobile electron accelerator of 0.7 MeV, 30 mA has been designed and examined by Monte Carlo technique. Based on a 3-D model of electron accelerator shielding which is designed with steel and lead shield, radiation leakage was examined using the Monte Carlo N-Particle Transport (MCNP) Code. Simulations with two different versions (version 4c2 and version 5) of MCNP code showed agreements within statistical uncertainties, and the highest leakage expected is 5.5061×10-01 (1±0.0454) μSv/h, which is far below the tolerable radiation dose limit for occupational workers. This unit could treat up to 500 m3 of liquid waste per day at 2 kGy or 10,000 N m3 of gases per hour at 15 kGy.

  13. Quantum cascade laser: Applications in chemical detection and environmental monitoring

    Directory of Open Access Journals (Sweden)

    Radovanović Jelena

    2009-01-01

    Full Text Available In this paper we consider the structural parameter optimization of the active region of a GaAs-based quantum cascade laser in order to maximize the optical gain of the laser at the characteristic wavelengths, which are best suited for detection of pollutant gasses, such as SO2, HNO3, CH4, and NH3, in the ambient air by means of direct absorption. The procedure relies on applying elaborate tools for global optimization, such as the genetic algorithm. One of the important goals is to extend the applicability of a single active region design to the detection of several compounds absorbing at close wave-lengths, and this is achieved by introducing a strong external magnetic field perpendicularly to the epitaxial layers. The field causes two-dimensional continuous energy subbands to split into the series of discrete Landau levels. Since the arrangement of Landau levels depends strongly on the magnitude of the magnetic field, this enables one to control the population inversion in the active region, and hence the optical gain. Furthermore, strong effects of band non-parabolicity result in subtle changes of the lasing wavelength at magnetic fields which maximize the gain, thus providing a path for fine-tuning of the output radiation properties and changing the target compound for detection. The numerical results are presented for quantum cascade laser structures designed to emit at specified wavelengths in the mid-infrared part of the spectrum.

  14. Eco-Balancing as a Guideline for Environmentally Sound Regional Planning Supported by GIS Applications

    Directory of Open Access Journals (Sweden)

    ROMAN J. M. LENZ

    2005-01-01

    Full Text Available During the last several years, environmental impact assessment, regional or spatial planning, and environmental balancing seem to develop similarities, e.g. joint basic methodological approaches such as the use of environmental indicators, the focus on same environmental goods such air, water, soil, flora/fauna, etc. (Lenz 1999. Especially GIS-based software systems show their multiple applications in these fields.After a short introduction about the central role of indicators in transdisciplinary problem solving processes, experiences from a set of regional environmental (or eco balances show a wide range of advantages as well as disadvantages in the context of the widespread use of GIS-based planning tools. Relying on concepts and examples for the spatial eco-balances in the district of Pfaffenhofen (Upper Bavaria, Germany; cf. Lenz 1997 and the municipality of Mulfingen (Hohenlohe, Germany - both of them related to the concept of environmental indicators of the Advisory Board of Environmental Affairs of the Federal Republic of Germany (SRU 1994 and the Federal Environmental Agency (UBA 1995 - we can show GIS-based information systems of a high practical relevancy. On the basis of the GIS software ArcView, the data base management system Access, and html scripts, we developed environmental information systems to balance environmental effects in a map scale of 1:5,000 - 1:50,000, in order to provide the administration with tools for an environmentally sound and sustainable development of their area (Lenz 1997, 1999, Beuttler et al. 1999. The spatial distribution of land use types, solar energy potential, area consumption and drinking water consumption for the municipality of Mulfingen are highlighted in this paper. Still, the practical use of the systems seems to be limited due to the lack of computer skills among the administrators – even after programming graphical user interfaces for the indicator “drinking water consumption”-, as well

  15. Program-Controlled High Voltage Module in Active Voltage Dividers(AVD) for MPGD

    CERN Document Server

    Ginting, Muhammad Fadhil

    2016-01-01

    Micro Pattern Gas Detectors (MPGD) applications are rapidly developing and became an important part of upgrades for the LHC detectors. RD51/CERN have worked on Active Voltage Divider (AVD) technology for multistage MPGDs, One of the next developments for the AVD is to design and integrate high voltage module in a single box. The Program-Controlled High Voltage Module, part of one AIDA2020 project, has been successfully designed and developed, and can be integrated in AVD design.

  16. Microbial Electrochemistry and its Application to Energy and Environmental Issues

    Science.gov (United States)

    Hastings, Jason Thomas

    Microbial electrochemistry forms the basis of a wide range of topics from microbial fuel cells to fermentation of carbon food sources. The ability to harness microbial electron transfer processes can lead to a greener and cleaner future. This study focuses on microbial electron transfer for liquid fuel production, novel electrode materials, subsurface environments and removal of unwanted byproducts. In the first chapter, exocellular electron transfer through direct contact utilizing passive electrodes for the enhancement of bio-fuel production was tested. Through the application of microbial growth in a 2-cell apparatus on an electrode surface ethanol production was enhanced by 22.7% over traditional fermentation. Ethanol production efficiencies of close to 95% were achieved in a fraction of the time required by traditional fermentation. Also, in this chapter, the effect of exogenous electron shuttles, electrode material selection and resistance was investigated. Power generation was observed using the 2-cell passive electrode system. An encapsulation method, which would also utilize exocellular transfer of electrons through direct contact, was hypothesized for the suspension of viable cells in a conductive polymer substrate. This conductive polymer substrate could have applications in bio-fuel production. Carbon black was added to a polymer solution to test electrospun polymer conductivity and cell viability. Polymer morphology and cell viability were imaged using electron and optical microscopy. Through proper encapsulation, higher fuel production efficiencies would be achievable. Electron transfer through endogenous exocellular protein shuttles was observed in this study. Secretion of a soluble redox active exocellular protein by Clostridium sp. have been shown utilizing a 2-cell apparatus. Cyclic voltammetry and gel electrophoresis were used to show the presence of the protein. The exocellular protein is capable of reducing ferrous iron in a membrane separated

  17. Technological Aspects: High Voltage

    CERN Document Server

    Faircloth, D C

    2013-01-01

    This paper covers the theory and technological aspects of high-voltage design for ion sources. Electric field strengths are critical to understanding high-voltage breakdown. The equations governing electric fields and the techniques to solve them are discussed. The fundamental physics of high-voltage breakdown and electrical discharges are outlined. Different types of electrical discharges are catalogued and their behaviour in environments ranging from air to vacuum are detailed. The importance of surfaces is discussed. The principles of designing electrodes and insulators are introduced. The use of high-voltage platforms and their relation to system design are discussed. The use of commercially available high-voltage technology such as connectors, feedthroughs and cables are considered. Different power supply technologies and their procurement are briefly outlined. High-voltage safety, electric shocks and system design rules are covered.

  18. ASPIS, A Flexible Multispectral System for Airborne Remote Sensing Environmental Applications

    Directory of Open Access Journals (Sweden)

    Riccardo Valentini

    2008-05-01

    Full Text Available Airborne multispectral and hyperspectral remote sensing is a powerful tool for environmental monitoring applications. In this paper we describe a new system (ASPIS composed by a 4-CCD spectral sensor, a thermal IR camera and a laser altimeter that is mounted on a flexible Sky-Arrow airplane. A test application of the multispectral sensor to estimate durum wheat quality is also presented.

  19. Application of Synchrotron Radiation in the Geological and Environmental Sciences

    Energy Technology Data Exchange (ETDEWEB)

    Jones, Keith W.

    1999-09-01

    A survey of some of the different ways that synchrotrons x-ray beams can be used to study geological materials is presented here. This field developed over a period of about 30 years, and it is clear that the geological community has made major use of the many synchrotrons facilities operating around the world during this time period. This was a time of rapid change in the operational performance of the synchrotrons facilities and this in itself has made it possible for geologists to develop new and more refined types of experiments that have yielded many important results. The advance in experimental techniques has proceeded in parallel with a revolution in computing techniques that has made it possible to cope with the great amount of data accumulated in the experiments. It is reasonable, although risky, to speculate about what might be expected to develop in the field during the next five- to ten-year period. It does seem plausible that the rate of change in the performance of what might now be called conventional x-ray storage rings will slow. There are no new facilities that are superior to the ESRF, ALS, APS, or SPring8 facilities under construction or about to come into operation. Thus, performance increments in the characteristics of the x-ray sources may come through the introduction of specialized devices in existing storage rings. The free electron laser is one example of a developing new technology that should take us into new regions of performance for radiation sources and stimulate new types of experimental applications. It is also likely that major advances will come through the introduction of more sophisticated experimental devices developed for use with the very recently operational undulator or wiggler sources at the newer rings. Improved x-ray optics and x-ray detectors and more powerful computation and high-speed data transmission can bring about more refined experiments and make the synchrotrons facilities more widely available to the

  20. Applications of Liquid-Phase Microextraction in the Sample Preparation of Environmental Solid Samples

    Directory of Open Access Journals (Sweden)

    Helena Prosen

    2014-05-01

    Full Text Available Solvent extraction remains one of the fundamental sample preparation techniques in the analysis of environmental solid samples, but organic solvents are toxic and environmentally harmful, therefore one of the possible greening directions is its miniaturization. The present review covers the relevant research from the field of application of microextraction to the sample preparation of environmental solid samples (soil, sediments, sewage sludge, dust etc. published in the last decade. Several innovative liquid-phase microextraction (LPME techniques that have emerged recently have also been applied as an aid in sample preparation of these samples: single-drop microextraction (SDME, hollow fiber-liquid phase microextraction (HF-LPME, dispersive liquid-liquid microextraction (DLLME. Besides the common organic solvents, surfactants and ionic liquids are also used. However, these techniques have to be combined with another technique to release the analytes from the solid sample into an aqueous solution. In the present review, the published methods were categorized into three groups: LPME in combination with a conventional solvent extraction; LPME in combination with an environmentally friendly extraction; LPME without previous extraction. The applicability of these approaches to the sample preparation for the determination of pollutants in solid environmental samples is discussed, with emphasis on their strengths, weak points and environmental impact.

  1. A Novel Cloud-Based Service Robotics Application to Data Center Environmental Monitoring.

    Science.gov (United States)

    Russo, Ludovico Orlando; Rosa, Stefano; Maggiora, Marcello; Bona, Basilio

    2016-08-08

    This work presents a robotic application aimed at performing environmental monitoring in data centers. Due to the high energy density managed in data centers, environmental monitoring is crucial for controlling air temperature and humidity throughout the whole environment, in order to improve power efficiency, avoid hardware failures and maximize the life cycle of IT devices. State of the art solutions for data center monitoring are nowadays based on environmental sensor networks, which continuously collect temperature and humidity data. These solutions are still expensive and do not scale well in large environments. This paper presents an alternative to environmental sensor networks that relies on autonomous mobile robots equipped with environmental sensors. The robots are controlled by a centralized cloud robotics platform that enables autonomous navigation and provides a remote client user interface for system management. From the user point of view, our solution simulates an environmental sensor network. The system can easily be reconfigured in order to adapt to management requirements and changes in the layout of the data center. For this reason, it is called the virtual sensor network. This paper discusses the implementation choices with regards to the particular requirements of the application and presents and discusses data collected during a long-term experiment in a real scenario.

  2. A Novel Cloud-Based Service Robotics Application to Data Center Environmental Monitoring

    Directory of Open Access Journals (Sweden)

    Ludovico Orlando Russo

    2016-08-01

    Full Text Available This work presents a robotic application aimed at performing environmental monitoring in data centers. Due to the high energy density managed in data centers, environmental monitoring is crucial for controlling air temperature and humidity throughout the whole environment, in order to improve power efficiency, avoid hardware failures and maximize the life cycle of IT devices. State of the art solutions for data center monitoring are nowadays based on environmental sensor networks, which continuously collect temperature and humidity data. These solutions are still expensive and do not scale well in large environments. This paper presents an alternative to environmental sensor networks that relies on autonomous mobile robots equipped with environmental sensors. The robots are controlled by a centralized cloud robotics platform that enables autonomous navigation and provides a remote client user interface for system management. From the user point of view, our solution simulates an environmental sensor network. The system can easily be reconfigured in order to adapt to management requirements and changes in the layout of the data center. For this reason, it is called the virtual sensor network. This paper discusses the implementation choices with regards to the particular requirements of the application and presents and discusses data collected during a long-term experiment in a real scenario.

  3. A Novel Cloud-Based Service Robotics Application to Data Center Environmental Monitoring

    Science.gov (United States)

    Russo, Ludovico Orlando; Rosa, Stefano; Maggiora, Marcello; Bona, Basilio

    2016-01-01

    This work presents a robotic application aimed at performing environmental monitoring in data centers. Due to the high energy density managed in data centers, environmental monitoring is crucial for controlling air temperature and humidity throughout the whole environment, in order to improve power efficiency, avoid hardware failures and maximize the life cycle of IT devices. State of the art solutions for data center monitoring are nowadays based on environmental sensor networks, which continuously collect temperature and humidity data. These solutions are still expensive and do not scale well in large environments. This paper presents an alternative to environmental sensor networks that relies on autonomous mobile robots equipped with environmental sensors. The robots are controlled by a centralized cloud robotics platform that enables autonomous navigation and provides a remote client user interface for system management. From the user point of view, our solution simulates an environmental sensor network. The system can easily be reconfigured in order to adapt to management requirements and changes in the layout of the data center. For this reason, it is called the virtual sensor network. This paper discusses the implementation choices with regards to the particular requirements of the application and presents and discusses data collected during a long-term experiment in a real scenario. PMID:27509505

  4. Environmental and biological applications and implications of soft and condensed nanomaterials

    Science.gov (United States)

    Chen, Pengyu

    Recent innovations and growth of nanotechnology have spurred exciting technological and commercial developments of nanomaterails. Their appealing physical and physicochemical properties offer great opportunities in biological and environmental applications, while in the meantime may compromise human health and environmental sustainability through either unintentional exposure or intentional discharge. Accordingly, this dissertation exploits the physicochemical behavior of soft dendritic polymers for environmental remediation and condensed nano ZnO tetrapods for biological sensing (Chapter two-four), and further delineate the environmental implications of such nanomaterials using algae- the major constituent of the aquatic food chain-as a model system (Chapter five). This dissertation is presented as follows. Chapter one presents a general review of the characteristic properties, applications, forces dictating nanomaterials, and their biological and environmental implications of the most produced and studied soft and condensed nanomaterials. In addition, dendritic polymers and ZnO nanomaterials are thoroughly reviewed separately. Chapter two investigates the physicochemical properties of poly(amidoamine)-tris(hydroxymethyl)amidomethane- dendrimer for its potential applications in water purification. The binding mechanisms and capacities of this dendrimer in hosting major environmental pollutants including cationic copper, anionic nitrate, and polyaromatic phenanthrene are discussed. Chapter three exploits a promising use of dendrimers for removal of potentially harmful discharged nanoparticles (NPs). Specifically, fullerenols are used as a model nanomaterial, and their interactions with two different generations of dendrimers are studied using spectrophotometry and thermodynamics methods. Chapter four elucidates two novel optical schemes for sensing environmental pollutants and biological compounds using dendrimer-gold nanowire complex and gold-coated ZnO tetrapods

  5. Stray voltage mitigation

    Energy Technology Data Exchange (ETDEWEB)

    Jamali, B.; Piercy, R.; Dick, P. [Kinetrics Inc., Toronto, ON (Canada). Transmission and Distribution Technologies

    2008-04-09

    This report discussed issues related to farm stray voltage and evaluated mitigation strategies and costs for limiting voltage to farms. A 3-phase, 3-wire system with no neutral ground was used throughout North America before the 1930s. Transformers were connected phase to phase without any electrical connection between the primary and secondary sides of the transformers. Distribution voltage levels were then increased and multi-grounded neutral wires were added. The earth now forms a parallel return path for the neutral current that allows part of the neutral current to flow continuously through the earth. The arrangement is responsible for causing stray voltage. Stray voltage causes uneven milk production, increased incidences of mastitis, and can create a reluctance to drink water amongst cows when stray voltages are present. Off-farm sources of stray voltage include phase unbalances, undersized neutral wire, and high resistance splices on the neutral wire. Mitigation strategies for reducing stray voltage include phase balancing; conversion from single to 3-phase; increasing distribution voltage levels, and changing pole configurations. 22 refs., 5 tabs., 13 figs.

  6. High voltage engineering

    CERN Document Server

    Rizk, Farouk AM

    2014-01-01

    Inspired by a new revival of worldwide interest in extra-high-voltage (EHV) and ultra-high-voltage (UHV) transmission, High Voltage Engineering merges the latest research with the extensive experience of the best in the field to deliver a comprehensive treatment of electrical insulation systems for the next generation of utility engineers and electric power professionals. The book offers extensive coverage of the physical basis of high-voltage engineering, from insulation stress and strength to lightning attachment and protection and beyond. Presenting information critical to the design, selec

  7. High voltage test techniques

    CERN Document Server

    Kind, Dieter

    2001-01-01

    The second edition of High Voltage Test Techniques has been completely revised. The present revision takes into account the latest international developments in High Voltage and Measurement technology, making it an essential reference for engineers in the testing field.High Voltage Technology belongs to the traditional area of Electrical Engineering. However, this is not to say that the area has stood still. New insulating materials, computing methods and voltage levels repeatedly pose new problems or open up methods of solution; electromagnetic compatibility (EMC) or components and systems al

  8. Mitigation of Unbalanced Voltage Sags and Voltage Unbalance in CIGRE Low Voltage Distribution Network

    OpenAIRE

    Mustafa, Ghullam; Bak-Jensen, Birgitte; Mahat, Pukar; Cecati, Carlo

    2013-01-01

    Any problem with voltage in a power network is undesirable as it aggravates the quality of the power. Power electronic devices such as Voltage Source Converter (VSC) based Static Synchronous Compensator (STATCOM) etc. can be used to mitigate the voltage problems in the distribution system. The voltage problems dealt with in this paper are to show how to mitigate unbalanced voltage sags and voltage unbalance in the CIGRE Low Voltage (LV) test network and net-works like this. The voltage unbala...

  9. Ceramic materials for energy and environmental applications: Functionalizing of properties by tailored compositions

    DEFF Research Database (Denmark)

    Ivanova, Mariya; Ricote, Sandrine; Baumann, Stefan

    2013-01-01

    Stable social development requires novel approaches for energy production, distribution and storage combined with reasonable restrictions of the environmental impact. The fuel cell-based technologies, as well as the separation of gases from mixtures, particularly implemented into innovative power....... This chapter is dedicated to the fascinating world of tailoring ceramic materials for energy and environmental applications. Selected approaches to tune ceramics will be discussed to illustrate the versatile effects that compositional variation can have on the macroscopic properties, e.g. the conductivity...... additives and substituents on sinterability, electrical/electrochemical properties and stability of selected ceramic materials for energy and environmental applications. The material variety will cover ceramic materials with different crystal structures like fluorites, perovskites, pyrochlores, fergusonites...

  10. 77 FR 129 - Golden Eagles; Programmatic Take Permit Application; Draft Environmental Assessment; West Butte...

    Science.gov (United States)

    2012-01-03

    ... issued under our new permitting regulations. We invite public comment on a draft environmental assessment (DEA), which evaluates alternatives for this permit application. DATES: To ensure consideration, please send your written comments by February 2, 2011. ADDRESSES: You may download a copy of the DEA on the...

  11. Application of carbonation model for service life design to Serbian environmental conditions and engineering practice

    NARCIS (Netherlands)

    Lukovic, M.; Ignjatovic, I.

    2012-01-01

    This paper highlights the application of carbonation model for service life design to local, Serbian environmental conditions and engineering practice. The basis of service life design using probabilistic approach and the deterioration model are presented. According to the data obtained from differe

  12. 30 CFR 905.783 - Underground mining permit applications-Minimum requirements for information on environmental...

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 3 2010-07-01 2010-07-01 false Underground mining permit applications-Minimum... MINING OPERATIONS WITHIN EACH STATE CALIFORNIA § 905.783 Underground mining permit applications—Minimum requirements for information on environmental resources. (a) Part 783 of this chapter, Underground Mining...

  13. 30 CFR 922.783 - Underground mining permit applications-minimum requirements for information on environmental...

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 3 2010-07-01 2010-07-01 false Underground mining permit applications-minimum... MINING OPERATIONS WITHIN EACH STATE MICHIGAN § 922.783 Underground mining permit applications—minimum requirements for information on environmental resources. Part 783 of this chapter, Underground Mining Permit...

  14. 30 CFR 903.783 - Underground mining permit applications-Minimum requirements for information on environmental...

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 3 2010-07-01 2010-07-01 false Underground mining permit applications-Minimum... MINING OPERATIONS WITHIN EACH STATE ARIZONA § 903.783 Underground mining permit applications—Minimum requirements for information on environmental resources. (a) Part 783 of this chapter, Underground Mining...

  15. 30 CFR 937.783 - Underground mining permit applications-minimum requirements for information on environmental...

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 3 2010-07-01 2010-07-01 false Underground mining permit applications-minimum... MINING OPERATIONS WITHIN EACH STATE OREGON § 937.783 Underground mining permit applications—minimum requirements for information on environmental resources. Part 783 of this chapter, Underground Mining Permit...

  16. 30 CFR 921.783 - Underground mining permit applications-minimum requirements for information on environmental...

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 3 2010-07-01 2010-07-01 false Underground mining permit applications-minimum... MINING OPERATIONS WITHIN EACH STATE MASSACHUSETTS § 921.783 Underground mining permit applications—minimum requirements for information on environmental resources. Part 783 of this chapter, Underground...

  17. 30 CFR 939.783 - Underground mining permit applications-minimum requirements for information on environmental...

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 3 2010-07-01 2010-07-01 false Underground mining permit applications-minimum... MINING OPERATIONS WITHIN EACH STATE RHODE ISLAND § 939.783 Underground mining permit applications—minimum requirements for information on environmental resources. Part 783 of this chapter, Underground Mining Permit...

  18. 30 CFR 933.783 - Underground mining permit applications-minimum requirements for information on environmental...

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 3 2010-07-01 2010-07-01 false Underground mining permit applications-minimum... MINING OPERATIONS WITHIN EACH STATE NORTH CAROLINA § 933.783 Underground mining permit applications—minimum requirements for information on environmental resources. Part 783 of this chapter, Underground...

  19. 30 CFR 912.783 - Underground mining permit applications-minimum requirements for information on environmental...

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 3 2010-07-01 2010-07-01 false Underground mining permit applications-minimum... MINING OPERATIONS WITHIN EACH STATE IDAHO § 912.783 Underground mining permit applications—minimum requirements for information on environmental resources. Part 783 of this chapter, Underground Mining Permit...

  20. 30 CFR 910.783 - Underground mining permit applications-minimum requirements for information on environmental...

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 3 2010-07-01 2010-07-01 false Underground mining permit applications-minimum... MINING OPERATIONS WITHIN EACH STATE GEORGIA § 910.783 Underground mining permit applications—minimum requirements for information on environmental resources. Part 783 of this chapter, Underground Mining Permit...

  1. DATA FOR ENVIRONMENTAL MODELING (D4EM): BACKGROUND AND EXAMPLE APPLICATIONS OF DATA AUTOMATION

    Science.gov (United States)

    Data is a basic requirement for most modeling applications. Collecting data is expensive and time consuming. High speed internet connections and growing databases of online environmental data go a long way to overcoming issues of data scarcity. Among the obstacles still remaining...

  2. Possible application of the Environmental Relative Moldiness Index in France: A pilot study in Brittany

    Science.gov (United States)

    Our goal was to determine if the US Environmental Relative Moldiness Index (ERMI) scale might have application in France. Twenty homes in Brittany, north western region of France were classified by inspection as “Moldy” or “Non-Moldy”. Dust and air samples were collected (MiTest ...

  3. Connection of Environmental Education with Application of Experiential Teaching Methods: A Case Study from Greece

    Science.gov (United States)

    Koutsoukos, Marios; Fragoulis, Iosif; Valkanos, Euthimios

    2015-01-01

    The main objective of this case study is to examine secondary education teachers' opinions concerning the connection of environmental education with the use of experiential teaching methods. Exploring whether the application of experiential methods can upgrade the learning procedure, leading to a more holistic approach, the research focuses on…

  4. 18 CFR 380.12 - Environmental reports for Natural Gas Act applications.

    Science.gov (United States)

    2010-04-01

    ...) Describe how the applicant would control and monitor the drilling activity of others within the field and... safety and environmental safeguards required by state and Federal drilling regulations. (i) Resource... detection system showing the location of combustible-gas detectors, fire detectors, heat detectors, smoke...

  5. Algorithms for energy efficient data extraction from wireless sensor networks for environmental monitoring applications

    NARCIS (Netherlands)

    Chatterjea, S.; Havinga, P.J.M.; Kooistra, L.; Ligtenberg, A.

    2008-01-01

    Wireless sensor networks (WSNs) can provide high resolution spatial and temporal data for environmental applications if they are densely deployed. However, as the nodes which make up the network are typically battery operated, a major problem faced by WSNs is limited network lifetime. In order to ex

  6. Voltage sag source location based on instantaneous energy detection

    DEFF Research Database (Denmark)

    Chen, Zhe; Xinzhou, Dong; Wei, Kong

    2007-01-01

    Voltage sag is the major power quality problem, which could disrupt the operation of sensitive equipment. This paper presents the applications of instantaneous energy direction for voltage sag source detection. Simulations have been performed to provide the analysis for system with distributed ge...... generation units. The studies show that the presented method can effectively detect the location of the voltage sag source....

  7. Green Synthesis of Iron Nanoparticles and Their Environmental Applications and Implications.

    Science.gov (United States)

    Saif, Sadia; Tahir, Arifa; Chen, Yongsheng

    2016-11-12

    Recent advances in nanoscience and nanotechnology have also led to the development of novel nanomaterials, which ultimately increase potential health and environmental hazards. Interest in developing environmentally benign procedures for the synthesis of metallic nanoparticles has been increased. The purpose is to minimize the negative impacts of synthetic procedures, their accompanying chemicals and derivative compounds. The exploitation of different biomaterials for the synthesis of nanoparticles is considered a valuable approach in green nanotechnology. Biological resources such as bacteria, algae fungi and plants have been used for the production of low-cost, energy-efficient, and nontoxic environmental friendly metallic nanoparticles. This review provides an overview of various reports of green synthesised zero valent metallic iron (ZVMI) and iron oxide (Fe₂O₃/Fe₃O₄) nanoparticles (NPs) and highlights their substantial applications in environmental pollution control. This review also summarizes the ecotoxicological impacts of green synthesised iron nanoparticles opposed to non-green synthesised iron nanoparticles.

  8. Analysis of 129I and its Application as Environmental Tracer

    DEFF Research Database (Denmark)

    Hou, Xiaolin; Hou, Yingkun

    2012-01-01

    Iodine-129, the long-lived radioisotope of iodine, occurs naturally, but anthropogenic generated 129I has dominated the environment in the past 60 years. Due to active chemical and environmental properties of iodine and the enhanced analytical capacity for 129I measurement, the application of 129I...... as an environmental tracer has highly increased in the past 10 years. Neutron activation analysis and accelerator mass spectrometry are the only techniques for measurement of 129I at environmental level. This article mainly compares these two analytical techniques for the determination of 129I at environmental level......, and highlights the progress of these analytical methods for chemical separation and sensitive measurement of 129I. The naturally occurred 129I has been used for age dating of samples/events in a range of 2-80 Ma. For the purpose of this study, an initial value of 129I has to be measured. Some progress...

  9. Developing CO2 emission parameters to measure the environmental impact on cooling applications

    Energy Technology Data Exchange (ETDEWEB)

    Sogut, M.Z. [Technical Sciences Department, Army Academy (Turkey)], email: mzsogut@kho.edu.tr

    2011-07-01

    In the past decades, it was found that refrigerants used in cooling systems, such as ammonia, were having a significant negative impact on global warming and ozone depletion; their use has therefore been limited and hydrofluorocarbon fluids have replaced them. The aim of this paper is to compare the different refrigerants used in all kind of applications in terms of exergy and environmental performance. Analyses were conducted on a 1 kW cooling capacity system using the vapor compressor cooling cycle; environmental performance was determined using the environmental impact factor (EIF) and the integrated impact factor (ICF). Results showed that R134A fluid has the best coefficient of performance (COP) and exergy efficiency as well as the lowest emission value of all refrigerants. This study demonstrated that exergy efficiency should be preferred to COP when assessing cooling systems' performances and that EIF should be preferred to ICF when determining their environmental effects.

  10. Green Synthesis of Iron Nanoparticles and Their Environmental Applications and Implications

    Directory of Open Access Journals (Sweden)

    Sadia Saif

    2016-11-01

    Full Text Available Recent advances in nanoscience and nanotechnology have also led to the development of novel nanomaterials, which ultimately increase potential health and environmental hazards. Interest in developing environmentally benign procedures for the synthesis of metallic nanoparticles has been increased. The purpose is to minimize the negative impacts of synthetic procedures, their accompanying chemicals and derivative compounds. The exploitation of different biomaterials for the synthesis of nanoparticles is considered a valuable approach in green nanotechnology. Biological resources such as bacteria, algae fungi and plants have been used for the production of low-cost, energy-efficient, and nontoxic environmental friendly metallic nanoparticles. This review provides an overview of various reports of green synthesised zero valent metallic iron (ZVMI and iron oxide (Fe2O3/Fe3O4 nanoparticles (NPs and highlights their substantial applications in environmental pollution control. This review also summarizes the ecotoxicological impacts of green synthesised iron nanoparticles opposed to non-green synthesised iron nanoparticles.

  11. Low voltage electron beam accelerators

    Energy Technology Data Exchange (ETDEWEB)

    Ochi, Masafumi [Iwasaki Electric Co., Ltd., Tokyo (Japan)

    2003-02-01

    Widely used electron accelerators in industries are the electron beams with acceleration voltage at 300 kV or less. The typical examples are shown on manufactures in Japan, equipment configuration, operation, determination of process parameters, and basic maintenance requirement of the electron beam processors. New electron beam processors with acceleration voltage around 100 kV were introduced maintaining the relatively high dose speed capability of around 10,000 kGy x mpm at production by ESI (Energy Science Inc. USA, Iwasaki Electric Group). The application field like printing and coating for packaging requires treating thickness of 30 micron or less. It does not require high voltage over 110 kV. Also recently developed is a miniature bulb type electron beam tube with energy less than 60 kV. The new application area for this new electron beam tube is being searched. The drive force of this technology to spread in the industries would be further development of new application, process and market as well as the price reduction of the equipment, upon which further acknowledgement and acceptance of the technology to societies and industries would entirely depend. (Y. Tanaka)

  12. Influence of Dynamic Properties of Nonlinear Over-Voltage Limiter on Over-Voltage Limitation in Distribution Networks

    Directory of Open Access Journals (Sweden)

    A. N. Bokhan

    2009-01-01

    Full Text Available One of the most efficient means of over-voltage reduction in arcing ground short-circuits is an application of   a nonlinear over-voltage limiter. It is necessary to take into account dynamic properties of the nonlinear over-voltage limiter in order to ensure authentic simulation of  over-voltage in the network A dynamic model of  the non-linear over-voltage limiter which takes a time lag constant   τ  into account during transition of the nonlinear over-voltage limiter into conducting state has been developed in the paper.

  13. Recent development of carbon electrode materials and their bioanalytical and environmental applications.

    Science.gov (United States)

    Zhang, Wei; Zhu, Shuyun; Luque, Rafael; Han, Shuang; Hu, Lianzhe; Xu, Guobao

    2016-02-07

    Carbon materials have been extensively investigated due to their diversity, favorable properties, and active applications including electroanalytical chemistry. This critical review discusses new synthetic methods, novel carbon materials, new properties and electroanalytical applications of carbon materials particularly related to the preparation as well as bioanalytical and environmental applications of highly oriented pyrolytic graphite, graphene, carbon nanotubes, various carbon films (e.g. pyrolyzed carbon films, boron-doped diamond films and diamond-like carbon films) and screen printing carbon electrodes. Future perspectives in the field have also been discussed (366 references).

  14. Application of the Environmental Protection Agency`s data quality objective process to environmental monitoring quality control

    Energy Technology Data Exchange (ETDEWEB)

    Garcia, Lucinda M. [Univ. of San Francisco, CA (United States)

    1995-11-01

    The United States Environmental Protection Agency`s (EPA) Data Quality Objectives (DQO) process was applied to two environmental monitoring networks for the purpose of optimizing field quality control sampling to give the highest quality monitoring data with minimal impact on resources. The DQO process, developed primarily to aid in cleanup and restoration activities, is a systematic approach to designing sampling, and analysis programs with improved efficiency, cost savings, and measureable and traceable data quality. The two monitoring- networks studied had not been subjected to the systematic review and analysis of the DQO process defined by the EPA. The two monitoring networks studied had relied upon field duplicates or replicates as the main source of field quality control data. Sometimes, both duplicate and routine sample were analyzed by the same analytical laboratory; at other times they were analyzed by different laboratories. This study identified some potential inconsistencies between analytical data and reporting limits from two different laboratories. Application of the EPA DQO process resulted in recommendations for changes in the field quality control sampling program, allowed new insight into the monitoring data, and raised several issues that should be the subject of further investigation.

  15. Applications of capillary electrophoresis with chemiluminescence detection in clinical, environmental and food analysis. A review

    Energy Technology Data Exchange (ETDEWEB)

    Lara, Francisco J.; Airado-Rodríguez, Diego; Moreno-González, David; Huertas-Pérez, José F.; García-Campaña, Ana M., E-mail: amgarcia@ugr.es

    2016-03-24

    This paper reviews the latest developments and analytical applications of chemiluminescence detection coupled to capillary electrophoresis (CE-CL). Different sections considering the most common CL systems have been included, such as the tris(2,2′-bipyridine)ruthenium(II) system, the luminol and acridinium derivative reactions, the peroxyoxalate CL or direct oxidations. Improvements in instrumental designs, new strategies for improving both resolution and sensitivity, and applications in different fields such as clinical, pharmaceutical, environmental and food analysis have been included. This review covers the literature from 2010 to 2015. - Highlights: • An up-to-date critical review about the evolution of CE-CL is presented. • Tris(2,2′-bipyridine)ruthenium(II) and luminol as the most used CL systems. • Instrumental designs and strategies for improving resolution and sensitivity. • Applications in clinical, pharmaceutical, environmental and food analysis.

  16. Novel kite-like ZnO nano-tetrapods for sustainable environmental applications

    Science.gov (United States)

    Pal, Shreyasi; Maiti, S.; Chattopadhyay, K. K.

    2017-05-01

    ZnO nanostructured morphology with either geometry or composition complexity has been widely studied due to their unique material properties and excellent performance in environmental applications as well as in electronics, optics, and photonics. Emerging trends in research lying in a variety of ZnO nanoforms especially on unique classes of ZnO nano-tetrapods, which offer high surface area, synergistic interactions, and multiple functionalities thus breeding an increasing interest in the environmental applications towards the photocatalytic dye degradation, water remediation, gas sensing, biosensing etc. This work presents a novel method for the synthesis of scalable amount of normal and kite-like ZnO nano-tetrapods via restricted open air oxidation of gold coated zinc foil in regular muffle furnace and their effectiveness in photocatalysis. Not restricted to photocatalytic applications only they have other propitious in the electronic and optoelectronic arena also.

  17. Calcium polysulphide, its applications and emerging risk of environmental pollution-a review article.

    Science.gov (United States)

    Dahlawi, Saad Mohammed; Siddiqui, Samreen

    2017-01-01

    Easy availability, preparation technique, and economic value make calcium polysulphide (CaS x ) a very useful inorganic chemical for various field and industrial applications. In this article, disparate applications of CaS x solution have been reviewed to suggest potential and future consolidation. This article also encompasses the physiochemical properties and production of CaS x solution, with critical appraisal on research focusing on CaS x application in agriculture industries and removal of potentially toxic elements (PTEs) from the environment. The kinetics of CaS x , technical issues associated with optimization of its dosage and environmental fate is also discussed in detail. This study covers almost all of the peer-reviewed research that has been performed since 1914. Some of the critiques in this article include the lack of integration between the exposure effect and the efficiency of treatment method, effects of oxidizing environments on the long-term performance of CaS x solution, and kinetics of CaS x solution with the PTEs. The working model of CaS x with PTEs is still system dependent, and therefore cannot be used with other applications. The kinetics of CaS x is described in detail with various phase stoichiometric reactions. Environmental fate is discussed based on applications, government reports, peer-reviewed articles and kinetics of CaS x , which provides a clear picture of emerging contaminants in the environment in relation to the insect resistance and ecotoxicology. Real time, lab based research articles are needed to identify toxicity limits of CaS x in environment in order to describe its effective permissible limit in environmental system. This review article provides a risk assessment of environmental pollution by CaS x based on its physicochemical characteristic, stoichiometry, kinetics, field, and industrial applications.

  18. Battery voltage-balancing applications of disk-type radial mode Pb(Zr • Ti)O3 ceramic resonator

    Science.gov (United States)

    Thenathayalan, Daniel; Lee, Chun-gu; Park, Joung-hu

    2017-10-01

    In this paper, we propose a novel technique to build a charge-balancing circuit for series-connected battery strings using various kinds of disk-type ceramic Pb(Zr • Ti)O3 piezoelectric resonators (PRs). The use of PRs replaces the whole external battery voltage-balancer circuit, which consists mainly of a bulky magnetic element. The proposed technique is validated using different ceramic PRs and the results are analyzed in terms of their physical properties. A series-connected battery string with a voltage rating of 61.5 V is set as a hardware prototype under test, then the power transfer efficiency of the system is measured at different imbalance voltages. The performance of the proposed battery voltage-balancer circuit employed with a PR is also validated through hardware implementation. Furthermore, the temperature distribution image of the PR is obtained to compare power transfer efficiency and thermal stress under different operating conditions. The test results show that the battery voltage-balancer circuit can be successfully implemented using PRs with the maximum power conversion efficiency of over 96% for energy storage systems.

  19. Voltage verification unit

    Science.gov (United States)

    Martin, Edward J.

    2008-01-15

    A voltage verification unit and method for determining the absence of potentially dangerous potentials within a power supply enclosure without Mode 2 work is disclosed. With this device and method, a qualified worker, following a relatively simple protocol that involves a function test (hot, cold, hot) of the voltage verification unit before Lock Out/Tag Out and, and once the Lock Out/Tag Out is completed, testing or "trying" by simply reading a display on the voltage verification unit can be accomplished without exposure of the operator to the interior of the voltage supply enclosure. According to a preferred embodiment, the voltage verification unit includes test leads to allow diagnostics with other meters, without the necessity of accessing potentially dangerous bus bars or the like.

  20. Synergetic Use of Crowdsourcing for Environmental Science Research, Applications and Education

    Science.gov (United States)

    Nair, U. S.; Thau, D.

    2015-12-01

    Environmental science research and applications often utilize information that is not readily available or routinely collected by government agencies. Whereas, the quality and quantity of environmental monitoring data is continually improving (e. g., spectral and spatial resolution of satellite imagery) contextual information needed to effectively utilize the data is sparse. Examples of such contextual information include ground truth data for land cover classification, presence/absence of species, prevalence of mosquito breeding sites and characteristics of urban land cover. Often, there are no agencies tasked with routine collection of such contextual information, which could be effectively collected through crowdsourcing. Crowdsourcing of such information, that is useful for environmental science research and applications, also provide opportunities for experiential learning at all levels of education. Appropriately designed crowdsourcing activity can be transform students from passive recipients of information to generators of knowledge. Multiple examples of synergistic use of crowdsourcing, developed by the Public Environmental Education and Research Apps (PEERA) group, at the University of Alabama in Huntsville will be presented. One example is crowdsourcing of land use and land cover (LULC) data using Open Data Kit (ODK) and associated analysis of satellite imagery using Google Earth Engine (GEE). Implementation of this activity as inquiry based learning exercise, for both middle school and for pre-service teachers will be discussed. Another example will detail the synergy between crowdsourcing for biodiversity mapping in southern India and environmental education. Other crowdsourcing activities that offer potential for synergy between research and public education will also be discussed.

  1. Applicability of the "Frame of Reference" approach for environmental monitoring of offshore renewable energy projects.

    Science.gov (United States)

    Garel, Erwan; Rey, Cibran Camba; Ferreira, Oscar; van Koningsveld, Mark

    2014-08-01

    This paper assesses the applicability of the Frame of Reference (FoR) approach for the environmental monitoring of large-scale offshore Marine Renewable Energy (MRE) projects. The focus is on projects harvesting energy from winds, waves and currents. Environmental concerns induced by MRE projects are reported based on a classification scheme identifying stressors, receptors, effects and impacts. Although the potential effects of stressors on most receptors are identified, there are large knowledge gaps regarding the corresponding (positive and negative) impacts. In that context, the development of offshore MRE requires the implementation of fit-for-purpose monitoring activities aimed at environmental protection and knowledge development. Taking European legislation as an example, it is suggested to adopt standardized monitoring protocols for the enhanced usage and utility of environmental indicators. Towards this objective, the use of the FoR approach is advocated since it provides guidance for the definition and use of coherent set of environmental state indicators. After a description of this framework, various examples of applications are provided considering a virtual MRE project located in European waters. Finally, some conclusions and recommendations are provided for the successful implementation of the FoR approach and for future studies.

  2. Benefits and applications of interdisciplinary digital tools for environmental meta-reviews and analyses

    Science.gov (United States)

    Grubert, Emily; Siders, Anne

    2016-09-01

    Digitally-aided reviews of large bodies of text-based information, such as academic literature, are growing in capability but are not yet common in environmental fields. Environmental sciences and studies can benefit from application of digital tools to create comprehensive, replicable, interdisciplinary reviews that provide rapid, up-to-date, and policy-relevant reports of existing work. This work reviews the potential for applications of computational text mining and analysis tools originating in the humanities to environmental science and policy questions. Two process-oriented case studies of digitally-aided environmental literature reviews and meta-analyses illustrate potential benefits and limitations. A medium-sized, medium-resolution review (∼8000 journal abstracts and titles) focuses on topic modeling as a rapid way to identify thematic changes over time. A small, high-resolution review (∼300 full text journal articles) combines collocation and network analysis with manual coding to synthesize and question empirical field work. We note that even small digitally-aided analyses are close to the upper limit of what can be done manually. Established computational methods developed in humanities disciplines and refined by humanities and social science scholars to interrogate large bodies of textual data are applicable and useful in environmental sciences but have not yet been widely applied. Two case studies provide evidence that digital tools can enhance insight. Two major conclusions emerge. First, digital tools enable scholars to engage large literatures rapidly and, in some cases, more comprehensively than is possible manually. Digital tools can confirm manually identified patterns or identify additional patterns visible only at a large scale. Second, digital tools allow for more replicable and transparent conclusions to be drawn from literature reviews and meta-analyses. The methodological subfields of digital humanities and computational social

  3. Low-Voltage Continuous Electrospinning Patterning.

    Science.gov (United States)

    Li, Xia; Li, Zhaoying; Wang, Liyun; Ma, Guokun; Meng, Fanlong; Pritchard, Robyn H; Gill, Elisabeth L; Liu, Ye; Huang, Yan Yan Shery

    2016-11-30

    Electrospinning is a versatile technique for the construction of microfibrous and nanofibrous structures with considerable potential in applications ranging from textile manufacturing to tissue engineering scaffolds. In the simplest form, electrospinning uses a high voltage of tens of thousands volts to draw out ultrafine polymer fibers over a large distance. However, the high voltage limits the flexible combination of material selection, deposition substrate, and control of patterns. Prior studies show that by performing electrospinning with a well-defined "near-field" condition, the operation voltage can be decreased to the kilovolt range, and further enable more precise patterning of fibril structures on a planar surface. In this work, by using solution dependent "initiators", we demonstrate a further lowering of voltage with an ultralow voltage continuous electrospinning patterning (LEP) technique, which reduces the applied voltage threshold to as low as 50 V, simultaneously permitting direct fiber patterning. The versatility of LEP is shown using a wide range of combination of polymer and solvent systems for thermoplastics and biopolymers. Novel functionalities are also incorporated when a low voltage mode is used in place of a high voltage mode, such as direct printing of living bacteria; the construction of suspended single fibers and membrane networks. The LEP technique reported here should open up new avenues in the patterning of bioelements and free-form nano- to microscale fibrous structures.

  4. 2002 Wastewater Land Application Site Performance Reports for the Idaho National Engineering and Environmental Laboratory and Associated Documentation

    Energy Technology Data Exchange (ETDEWEB)

    Meachum, Teresa Ray; Michael G. Lewis

    2003-02-01

    The 2002 Wastewater Land Application site Performance Reports for the Idaho National Engineering and Environmental Laboratory describe site conditions for the facilities with State of Idaho Wastewater Land Application Permits. Permit-required monitoring data are summarized, and permit exceedences or environmental impacts relating to the operation of the facilities during the 2002 permit year are discussed.

  5. A critical review on sustainable biochar system through gasification: Energy and environmental applications.

    Science.gov (United States)

    You, Siming; Ok, Yong Sik; Chen, Season S; Tsang, Daniel C W; Kwon, Eilhann E; Lee, Jechan; Wang, Chi-Hwa

    2017-07-01

    This review lays great emphasis on production and characteristics of biochar through gasification. Specifically, the physicochemical properties and yield of biochar through the diverse gasification conditions associated with various types of biomass were extensively evaluated. In addition, potential application scenarios of biochar through gasification were explored and their environmental implications were discussed. To qualitatively evaluate biochar sustainability through the gasification process, all gasification products (i.e., syngas and biochar) were evaluated via life cycle assessment (LCA). A concept of balancing syngas and biochar production for an economically and environmentally feasible gasification system was proposed and relevant challenges and solutions were suggested in this review. Copyright © 2017 Elsevier Ltd. All rights reserved.

  6. Isothermal Microcalorimetry: A Review of Applications in Soil and Environmental Sciences

    Institute of Scientific and Technical Information of China (English)

    RONG Xing-Min; HUANG Qiao-Yun; JIANG Dai-Hua; CAI Peng; LIANG Wei

    2007-01-01

    Isothermal microcMorimetry provides thermodynamic and kinetic information on various reactions and processes and is thereby a powerful tool to elucidate their mechanisms.Certain improvement in isothermal microcalorimetry with regard to the studies on soil and environmental sciences is briefly described.This review mainly focuses on the use of microcalorimetry in the determination of soil microbial activity,monitoring the toxicity and biodegradation of soil organic pollutants,the risk evaluation of metals and metalloids,the heat effect of ion exchange and adsorption in soil,and environmental researches.Promising prospects for the applications of the technique in the field are also discussed.

  7. Alkali-activated binders/geopolymer and an application to environmental engineering

    Directory of Open Access Journals (Sweden)

    Nida Chaimoon

    2014-06-01

    Full Text Available For environmental reason, new binders that can be used as Portland cement replacement materials are being needed. Recently, alkali-activated binders (AAB and geopolymer have found increasing interest. As several research reports have showed that the two new binders are likely to have high potential to be developed and become an alternative to OPC. However, confusion in the classification of both binders is still there. This paper reviews knowledge about AAB and geopolymer including historical background, reaction mechanisms and reaction products. The similarities and differences of both binders are discussed. The application to environmental engineering on hazardous waste management using stabilization/solidification is also described.

  8. Accurate surface potential determination in Schottky diodes by the use of a correlated current and capacitance voltage measurements.Application to n-InP

    Institute of Scientific and Technical Information of China (English)

    Ali Ahaitouf; Abdelaziz Ahaitouf; Jean Paul Salvestrini; Hussein Srour

    2011-01-01

    Based on current voltage (I-Vg) and capacitance voltage (C-Vg) measurements,a reliable procedure is proposed to determine the effective surface potential Vd (Vg) in Schottky diodes.In the framework of thermionic emission,our analysis includes both the effect of the series resistance and the ideality factor,even voltage dependent.This technique is applied to n-type indium phosphide (n-InP) Schottky diodes with and without an interfacial layer and allows us to provide an interpretation of the observed peak on the C-Vg measurements.The study clearly shows that the depletion width and the flat band barrier height deduced from C-Vg,which are important parameters directly related to the surface potential in the semiconductor,should be estimated within our approach to obtain more reliable information.

  9. Note: Wide-range and high-resolution on-chip delay measurement circuit with low supply-voltage sensitivity for SoC applications

    Science.gov (United States)

    Sheng, Duo; Hung, Yu-Chan

    2016-11-01

    This paper presents an on-chip delay measurement (OCDM) circuit with a wide delay-measurement range, a high delay-measurement resolution and low supply-voltage sensitivity for efficient detection, and diagnosis in the high-performance system-on-chip (SoC). The proposed cascade-stage measurement structure can simultaneously achieve a delay-measurement range of several nanoseconds and a quantization resolution of several picoseconds. The proposed delay-measurement circuit has a high immunity to supply voltage variations without any additional calibration or self-biasing circuit. The delay-measurement range is 5.25 ns with 6 ps resolution; and the average delay resolution variation is 0.41% with ±10% supply voltage variations.

  10. Application of an uncertainty analysis approach to strategic environmental assessment for urban planning.

    Science.gov (United States)

    Liu, Yi; Chen, Jining; He, Weiqi; Tong, Qingyuan; Li, Wangfeng

    2010-04-15

    Urban planning has been widely applied as a regulatory measure to guide a city's construction and management. It represents official expectations on future population and economic growth and land use over the urban area. No doubt, significant variations often occur between planning schemes and actual development; in particular in China, the world's largest developing country experiencing rapid urbanization and industrialization. This in turn leads to difficulty in estimating the environmental consequences of the urban plan. Aiming to quantitatively analyze the uncertain environmental impacts of the urban plan's implementation, this article developed an integrated methodology combining a scenario analysis approach and a stochastic simulation technique for strategic environmental assessment (SEA). Based on industrial development scenarios, Monte Carlo sampling is applied to generate all possibilities of the spatial distribution of newly emerged industries. All related environmental consequences can be further estimated given the industrial distributions as input to environmental quality models. By applying a HSY algorithm, environmentally unacceptable urban growth, regarding both economic development and land use spatial layout, can be systematically identified, providing valuable information to urban planners and decision makers. A case study in Dalian Municipality, Northeast China, is used to illustrate applicability of this methodology. The impacts of Urban Development Plan for Dalian Municipality (2003-2020) (UDP) on atmospheric environment are also discussed in this article.

  11. Induced voltage in an open wire

    CERN Document Server

    Morawetz, K; Trupp, A

    2015-01-01

    A puzzle arising from Faraday's law is considered and solved concerning the question which voltage is induced in an open wire feeling a time-varying homogeneous magnetic field. The longitudinal electric field contributes 1/3 and the transverse field 2/3 to the induced voltage. The representation of a homogeneous and time-varying magnetic field implies unavoidably a certain symmetry point or line dependent on the geometry of the source. As a consequence the induced voltage of an open wire is found to be the area covered with respect to the symmetry line or point perpendicular to the magnetic field. This in turn allows to find the symmetry points of a magnetic field source by measuring the voltage of an open wire. We present two exactly solvable models for a symmetry point and for a symmetry line. The results are applicable to open circuit problems and for astrophysical applications.

  12. Eco-Environmental Factors in Green Roof Application in Indian Cities

    Science.gov (United States)

    Mukherjee, M.

    2014-09-01

    Green-roof is the cost-effective environmental mitigation strategy for urban areas [1]. Its application is limited in India primarily due to inadequate understanding about its cost-benefit analysis and technicalities of its maintenance. Increasing awareness about green roof can alter conservative attitude towards its application. So, this work presents a quantified study on green-roof types, cost and environmental benefits while considering different geo-urban climate scenarios for cities of Kolkata, Mumbai, Chennai and New Delhi. Cost estimation for extensive and intensive green-roof with reference to commonly used roof in urban India is also worked out. Attributes considered for environmental discussion are energy savings related to thermal heat gain through roof, roof-top storm-water drainage and sound attenuation. The comparative study confirms that further focused study on individual cities would identify city-specific objectives for green-roof application; strategies like awareness, capacity building programmes, incentives, demonstration projects etc. can be worked out accordingly for wider application of green-roof in Indian cities.

  13. Surface Modification of Graphene Oxides by Plasma Techniques and Their Application for Environmental Pollution Cleanup.

    Science.gov (United States)

    Wang, Xiangxue; Fan, Qiaohui; Chen, Zhongshan; Wang, Qi; Li, Jiaxing; Hobiny, Aatef; Alsaedi, Ahmed; Wang, Xiangke

    2016-02-01

    Graphene oxides (GOs) have come under intense multidisciplinary study because of their unique physicochemical properties and possible applications. The large amount of oxygen-containing functional groups on GOs leads to a high sorption capacity for the removal of various kinds of organic and inorganic pollutants from aqueous solutions in environmental pollution cleanup. However, the lack of selectivity results in difficulty in the selective removal of target pollutants from aqueous solutions in the presence of other coexisting pollutants. Herein, the surface grafting of GOs with special oxygen-containing functional groups using low-temperature plasma techniques and the application of the surface-modified GOs for the efficient removal of organic and inorganic pollutants in environmental pollution are reviewed. This paper gives an account of our research on the application of GO-based nanomaterials in environmental pollution cleanup, including: (1) the synthesis and surface grafting of functional groups on GOs, summarizing various types of low-temperature plasma techniques for the synthesis of graphene/GOs; and (2) the application of graphene/GOs and their composites for the efficient removal of organic and inorganic pollutants from aqueous solutions, including the interaction mechanism according to recently published results.

  14. Environmental geochemistry of calcium isotopes: Applications of a new stable isotope approach

    Institute of Scientific and Technical Information of China (English)

    LIU Zhanmin; LIU Congqiang; HAN Guilin; WANG Zhongliang; XUE Zichen; SONG Zhaoliang; YANG Cheng

    2006-01-01

    This paper summarizes isotope fractionation mechanism, analytical method and applications in environmental geochemistry of calcium isotopes. Calcium isotopic composition can be used to constrain material sources and study geological and environmental processes as the isotopic composition of calcium (δ 44Ca) and fractionation processes depend on geochemical circumstances in nature. Recently, thanks to current advances in analytical technology of calcium isotopes, calcium isotopes are broadly used in biological and geochemical studies, such as the mechanism of plants imbibing nutrients through their roots, calcium transport in the environmental ecosystem, calcium cycle in oceans and paleo-oceans and paleo-climate. The elementary data show that δ44Ca values vary from -2.88‰ to 0.92‰ in natural samples.

  15. Application of game theory to the interface between militarization and environmental stewardship in the Mariana Islands.

    Science.gov (United States)

    Marler, Thomas E; Wiecko, Greg; Moore, Aubrey

    2012-03-01

    We recently described threats to the terrestrial biological resources on the Mariana islands of Guam and Tinian resulting from the large-scale buildup of military operations. Attitudes that view these military buildup plans in a zero sum context whereby the positives of greater security and improved local economy can be attained only with corresponding negatives of environmental destruction are prevalent. We argue these attitudes oversimplify the complicated interactions between military operations and environmental damage. Here we discuss aspects of our case study that would benefit from application of game theory. Declines in ecosystem health are not unavoidable forms of collateral damage of peace-time military operations. We repeat, conservation of environmental resources is not ancillary to national security, it is integral.

  16. [Regional difference of NPK fertilizers application and environmental risk assessment in Jiangsu Province, China].

    Science.gov (United States)

    Liu, Qin-pu

    2015-05-01

    It is of great importance to have a deep understanding of the spatial distribution of NPK fertilizers application and the potential threat to the ecological environment in Jiangsu Province, which is helpful for regulating the rational fertilization, strengthening the fertilizer use risk management and guidance, and preventing agricultural non-point pollution. Based on the environmental risk assessment model with consideration of different impacts of N, P, K fertilizers on environment, this paper researched the regional differentiation characteristic and environmental risk of intensity of NPK fertilizer usages in Jiangsu. Analystic hierarchy process ( AHP) was used to determine the weithts of N, P, K. The environmental safety thresholds of N, P, K were made according to the standard of 250 kg · hm(-2) for the construction of ecological counties sponsered by Chinese government and the proportion of 1:0.5:0.5 for N:P:K surposed by some developed countries. The results showed that the intensity of NPK fertilizer application currently presented a gradually increasing trend from south to north of Jiangsu, with the extremum ratio of 3.3, and the extremum ratios of nitrogen fertilizer, phosphorus fertilizer and potassium fertilizer were 3.3, 4.5 and 4.4, respectively. The average proportion of nitrogen fertilizer, phosphorus fertilizer and potassium fertilizer of 13 cities in Jiangsu was 1:0.39:0.26. Their proportion was relatively in equilibrium in southern Jiangsu, but the nutrient structure disorder was serious in northern Jiangsu. In Jiangsu, the environmental risk index of fertilization averaged at 0.69 and in the middle-range of environmental risk. The environmental risk index of fertilizer application in southern and central Jiangsu was respectively at the low and moderate levels, while that of cities in northern Jiangsu was at the moderate, serious or severe level. In Jiangsu, the regional difference of fertilizer application and environmental risk assessment were

  17. Environmental barcoding: a next-generation sequencing approach for biomonitoring applications using river benthos.

    Science.gov (United States)

    Hajibabaei, Mehrdad; Shokralla, Shadi; Zhou, Xin; Singer, Gregory A C; Baird, Donald J

    2011-04-13

    Timely and accurate biodiversity analysis poses an ongoing challenge for the success of biomonitoring programs. Morphology-based identification of bioindicator taxa is time consuming, and rarely supports species-level resolution especially for immature life stages. Much work has been done in the past decade to develop alternative approaches for biodiversity analysis using DNA sequence-based approaches such as molecular phylogenetics and DNA barcoding. On-going assembly of DNA barcode reference libraries will provide the basis for a DNA-based identification system. The use of recently introduced next-generation sequencing (NGS) approaches in biodiversity science has the potential to further extend the application of DNA information for routine biomonitoring applications to an unprecedented scale. Here we demonstrate the feasibility of using 454 massively parallel pyrosequencing for species-level analysis of freshwater benthic macroinvertebrate taxa commonly used for biomonitoring. We designed our experiments in order to directly compare morphology-based, Sanger sequencing DNA barcoding, and next-generation environmental barcoding approaches. Our results show the ability of 454 pyrosequencing of mini-barcodes to accurately identify all species with more than 1% abundance in the pooled mixture. Although the approach failed to identify 6 rare species in the mixture, the presence of sequences from 9 species that were not represented by individuals in the mixture provides evidence that DNA based analysis may yet provide a valuable approach in finding rare species in bulk environmental samples. We further demonstrate the application of the environmental barcoding approach by comparing benthic macroinvertebrates from an urban region to those obtained from a conservation area. Although considerable effort will be required to robustly optimize NGS tools to identify species from bulk environmental samples, our results indicate the potential of an environmental barcoding

  18. Inner surface flash-over of insulator of low-inductance high-voltage self-breakdown gas switch and its application.

    Science.gov (United States)

    Zhang, Hong-Bo; Liu, Jin-liang

    2014-04-01

    In this paper, the inner surface flash-over of high-voltage self-breakdown switch, which is used as a main switch of pulse modulator, is analyzed in theory by employing the method of distributed element equivalent circuit. Moreover, the field distortion of the switch is simulated by using software. The results of theoretical analysis and simulation by software show that the inner surface flash-over usually starts at the junction points among the stainless steel, insulator, and insulation gas in the switch. A switch with improved structure is designed and fabricated according to the theoretical analysis and simulation results. Several methods to avoid inner surface flash-over are used to improve the structure of switch. In experiment, the inductance of the switch is no more than 100 nH, the working voltage of the switch is about 600 kV, and the output voltage and current of the accelerator is about 500 kV and 50 kA, respectively. And the zero-to-peak rise time of output voltage at matched load is less than 30 ns due to the small inductance of switch. The original switch was broken-down after dozens of experiments, and the improved switch has been worked more than 200 times stably.

  19. Application of Excel Function Calculation in Low Voltage Distribution System%Excel函数计算在低压配电系统中的应用

    Institute of Scientific and Technical Information of China (English)

    李磊

    2013-01-01

    In design process of low voltage distribution system, it carried out statistics, combing and induction to the selection of all data, and made analysis on conditions and formula of each data. Using Excel's powerful functions, according to the needs of low-voltage distribution system, so that it need only enters the basic parameters, draws all the data needed to the low-voltage distribution system by automatic calculation, and automatically converts to the format needed to low-voltage distribution system. Greatly improve the accuracy of the data and facilitate modifications in the design process, saving design time.%  在低压配电系统的设计过程中,对所有数据的选取进行统计、梳理、归纳,分析每个数据的得出条件、公式。利用Excel强大的函数计算功能,根据低压配电系统的需求,使其仅输入基本参数,自动计算得出低压配电系统所需要的全部数据,自动转换为低压配电系统所需要的格式。极大的提高数据准确性,方便设计过程中的修改、节约设计时间。

  20. Low-voltage gallium-indium-zinc-oxide thin film transistors based logic circuits on thin plastic foil: Building blocks for radio frequency identification application

    NARCIS (Netherlands)

    Tripathi, A.K.; Smits, E.C.P.; Putten, J.B.P.H. van der; Neer, M. van; Myny, K.; Nag, M.; Steudel, S.; Vicca, P.; O'Neill, K.; Veenendaal, E. van; Genoe, G.; Heremans, P.; Gelinck, G.H.

    2011-01-01

    In this work a technology to fabricate low-voltage amorphous gallium-indium-zinc oxide thin film transistors (TFTs) based integrated circuits on 25 µm foils is presented. High performance TFTs were fabricated at low processing temperatures (<150 °C) with field effect mobility around 17 cm2 /V s. The