Science.gov (United States)

The performance of a 42/28 V, 175 W, 50 kHz pulse-width modulated buck dc/dc switching power

International Nuclear Information System (INIS)

In this paper, an improved soft switched two cell interleaved boost AC/DC converter with high power factor is proposed and investigated. A new auxiliary circuit is designed and added to two cell interleaved boost converter to reduce the switching losses. The proposed auxiliary circuit is implemented using only one auxiliary switch and a minimum number of passive components without an important increase in the cost and complexity of the converter. The main advantage of this auxiliary circuit is that it not only provides zero-voltage-transition (ZVT) for the main switches but also provides soft switching for the auxiliary switch and diodes. Though all semiconductor devices operate under soft switching, they do not have any additional voltage and current stresses. The proposed converter operates ...

International Nuclear Information System (INIS)

Closing and breaking of current in microsecond megaampere plasma opening switches are considered. Conductivity current scaling in the switch due to plasma acceleration by a magnetic piston is discussed and compared with experimental data. Two ways of determining the width of a current channel are taken up. This channel results from the diffusion of the magnetic field in the plane of the piston followed by the convective ejection of the field frozen in the accelerated plasma flow behind the shock wave into the bridge. Based on experimental data, a scaling law for the voltage on the switch according to the switch parameters is derived. The problem of reverse closing, which limits the efficiency of storage energy extraction into the load, is considered

International Nuclear Information System (INIS)

Heavy ion tests of a switching converter using power MOSFETs have allowed us to identify the main parameters which affect the burnout sensitivity of these components. The differences between static and dynamic conditions are clarified in this paper. (author). 7 refs., 16 figs., 3 tabs.

British Library Electronic Table of Contents (United Kingdom)

The design and operating principle of a small (50 mm in diameter and 100 mm in height) ???-73C vacuum spark gap are described. It is shown that it can be efficiently switched using a control circuit with a low (?900 V) supply voltage, which is based on an inductive energy storage and a diode opening switch that forms a high-voltage igniting pulse with a rise time of nanosecond duration. The ???-73C switching process is investigated at different rise times of igniting voltage pulses and different igniting current amplitudes. The results of tests of the spark gap operating in regimes of switching current pulses with an amplitude of 12 kA and a rise time of 800 ns are presented.

CERN Document Server

High-power pseudospark and BLT switches

Energy Technology Data Exchange (ETDEWEB)

We have generated approximately 100 watts of frequency doubled light from the output of an electro-optically Q-switched, diode-pumped Nd:YAG slab laser oscillator operating at an average power of 200 watts (2.5 kHz repetition rate, 80 mJ/pulse, 25 ns pulsewidth). The Q-switch was a compensated z-axis propagation LiNbO{sub 3} electro-optic modulator, and the frequency conversion crystal was a thin slab of KTP. In addition, Q-switched operation at an average power of approximately 250 watts with 26 ns pulsewidths has been demonstrated.

Energy Technology Data Exchange (ETDEWEB)

The traveling-wave mode in ring lasers is achieved by two methods: by a reversing mirror, and by using an intracavity nonreciprocal device. This paper is devoted to realization of the traveling-wave mode in a mode-locked YAG-Nd ring laser by a method proposed by Tomov et al. This method uses two intracavity Q-switches. In mode-locked operation, pulses are generated that can be considered short compared with the period of modulation T = L/C (where L is the length of the perimeter of the cavity). Analysis shows that if the shift of the switching signals corresponds to the time of travel of a light pulse between Q-switches, the pulse in one direction will pass the Q-switches at instants of zero losses, while losses in the other direction will be maximized for a distance between Q-switches of L/4, and will be zero for a distance L/2. Experimental verification of the ...

Energy Technology Data Exchange (ETDEWEB)

Airborne pollutants can cause failures in switching and computing equipment. This paper focuses on a subset of such pollutants - airborne fine particles (<2.5 [mu]m diameter). It begins by examining the extent to which different improvements in heating, ventilating and air conditioning (HVAC) systems reduce indoor concentrations of fine particles. For each modification, the consequent reduction in soiling rate is derived. The concomitant increase in operating costs is also calculated. These costs are then compared with the costs of failures in telephone switching offices, leading to estimates of failure rate reductions that would make improvements cost-effective. Finally, the reduction in failures required to offset the costs of the improvements are compared with documented differences in failure rates between unimproved and improved environments. This study suggests that, in many telephone switching ...

International Nuclear Information System (INIS)

An optical klystron is built in the 800 MeV electron storage ring at University of Science and Technology of China for harmonic super-radiation generation. In single bunch operation mode the repetition rate of the spontaneous radiation pulses is about 4.533 MHz, and the repetition rate of the seed laser pulses is about 3 Hz, while the radiation pulse duration is 300 ps. For measuring harmonic radiation a high on/off ratio ICCD is used as an optical switch to reject spontaneous radiation pulses of high repetition rate

International Nuclear Information System (INIS)

The layout of the network with its frequency and transmission power control shows how the time behaviour of power plants and consumers determines the frequency curve during sudden power disturbances. As for switching processes in the network for the turbine, network operation entails loads due to shock-like disturbance functions to which one should not normally respond by switching off. The interception controllers are therefore adjusted via a simulation model by which the vibrations of the turbine rotor can be modelled in real time under different network loads. (GL).

Energy Technology Data Exchange (ETDEWEB)

This paper presents the analysis and novel hybrid controller design for an interleaved 2-quadrant switched capacitor (SC) bidirectional DC/DC converter for a hybrid electric vehicle (HEV) dual energy storage system. The designed novel control strategy enables simpler dynamics compared to a standard buck converter with input filter, good regulation capability, low EMI, lower source current ripple, ease of control, and continuous input current waveform in both buck as well as boost modes of operation.

Science.gov (United States)

... a rotating mirror Q-switch or an acousto-optic Q-switch. The former ... Q-switch up to 2000 pps. The Q-switched output bean, is predominantly ...

Energy Technology Data Exchange (ETDEWEB)

This thesis examines the design of a propulsion system for a series hybrid vehicle and includes the study of an energy storage unit using double-layer capacitors and a lightweight soft-switched converter system, and two new components in series hybrid vehicles. The development of environmentally sustainable vehicles is more urgent now given the fact that pollution levels are ever increasing. No electric vehicle has yet been developed that can compete with a normal vehicle based only on internal combustion engines. The dilemma lies in the difficulty of storing the amount of energy needed and supply it a high power levels. An attractive and viable option to reducing pollution and maintaining good performance may lie in hybrid electric-powered vehicles. The double-layer power capacitors are an interesting option because of their high power density and long lifetime. The devices are new and assembling large energy storage units must be thoroughly examined before using ...

International Nuclear Information System (INIS)

The spectrum of training aids used in the nuclear industry runs the gamut from the very basic (i.e., valve training aids - gate, globe, check) to the highly complex (i.e., nuclear full scope simulator). Designing and purchasing the best training aids take much time, detailed investigation, and good understanding of plant operations. The training aid that has given the New York Power Authority the best results has been the motor operator valve (MOV) trainer. Some of the items that make the MOV trainer a good choice are: (1) large number of MOVs in the plant, (2) importance of MOVs to safe plant operation, (3) detailed MOV procedures used by the plant, (4) history of MOV problems, and (5) ability to demonstrate important concepts and operation - hammer blow effect, torque and limit switch adjustment and functions, and actual sequence of operation of the limitorque ...

Energy Technology Data Exchange (ETDEWEB)

A gas-diesel dual fuel engine apparatus is described having a diesel engine, a diesel fuel supply system including a diesel fuel injection pump, a gaseous fuel supply system including a gaseous fuel regulating valve, and a governing and controlling device for governing the speed of the engine through the control of fuel supplied to the engine and controlling the switchover of the operation of the engine between a diesel fuel mode and a gaseous fuel mode. The improvement of the governing and controlling device consists of: (a) at least one electronic governor means adapted to compare a speed signal representing the actual operating speed of the diesel engine with a set speed signal representing the set speed thereof; (b) a pair of electric actuator means having respective power amplifier circuits and mechanically connected to the diesel fuel injection pump and the gaseous fuel regulating valve, respectively, for the actuation thereof; (c) mode ...

Energy Technology Data Exchange (ETDEWEB)

A low voltage FEL operating at 130 kV which can be run cw with a continuous electron beam current level up to 12 mA has been constructed for the X-Band microwave range (8-12 GHz). In this poster, we will report on the dependence on time, after the electron beam is switched on, of the growth and competition of those longitudinal modes in the cavity having nett gain.

Science.gov (United States)

... lasers, model switched optical memory elements ... Optical RS flip flop, Acousto-optic switches. ... FLOP CIRCUITS, OPTICAL SWITCHING, NOR GATES ...

Energy Technology Data Exchange (ETDEWEB)

Ways of reducing energy consumption in plastics processing are examined. Examples are given which illustrate how the awareness of everyone in the company to energy saving is essential with particular reference to switching arrangements to ensure such things as lights, machinery, compressed air systems are switched off when not needed or run at a lower level where appropriate. An understanding of the various elements of the electricity bill can inform a company`s planning of its operations to take advantage of lower tariffs. Machinery selection both with regard to efficiency of processing, quality of engineering and appropriate size can achieve significant savings and attention to maintenance is important. Fundamental to all aspects of energy saving is the monitoring of energy usage to identify where savings can be made and to evaluate the effectiveness of any measures taken. (UK)

Energy Technology Data Exchange (ETDEWEB)

Power quality problems are caused by activities normal to utility operations such as maintenance outages and capacitor switching or events that are abnormal such as lightning strikes and equipment failures. Disconnection and reconnection of transmission lines and transformers can cause switching surges, and are more severe on extra high voltage transmission lines than high voltage lines. Capacitor switching can cause transients and harmonics that may affect sensitive equipment, and are the source of 3rd, 5th, 7th and 9th harmonics in the hundreds of hertz ranges. Overload, sudden loss of generating capacity and transmission line faults are typical problems affecting system stability. Fault interruptions and reclosings can cause surges in the distribution system, and lightning strikes may cause voltage surges or dips due to arrester sparkover. Blackouts, brownouts, voltage fluctuations, travelling wave ...

International Nuclear Information System (INIS)

A Real-Time Operating System(RTOS) is an Operating System(OS) intended for real-time applications. Benchmarking is a point of reference by which something can be measured. The QNX is a Real Time Operating System(RTOS) developed by QSSL(QNX Software Systems Ltd.) in Canada. The ELMSYS is the brand name of commercially available Personal Computer(PC) for applications such as Cabinet Operator Module(COM) of Digital Plant Protection System(DPPS) and COM of Digital Engineered Safety Features Actuation System(DESFAS). The ELMSYS PC Hardware is being qualified by KTL(Korea Testing Lab.) for use as a Cabinet Operator Module(COM). The QNX RTOS is being dedicated by Korea Atomic Energy Research Institute (KAERI). This paper describes the outline and benchmarking test results on Context Switching, Message Passing, Synchronization and Deadline Violation of QNX RTOS under ...

Science.gov (United States)

... Abstract : The acousto-optic filter (AOF) is ... for large switch networks. ... FOURIER TRANSFORMATION, OPTICAL SWITCHING, SURFACE ACOUSTIC ...

Energy Technology Data Exchange (ETDEWEB)

This paper analyses the complex, non-linear effects of spot price drivers in wholesale electricity markets: their intra-day dynamics and transient irregularities. The context is the UK market, after the reforms introduced in March 2001, analysed with an original set of price drivers reflecting economic, technical, strategic, risk, behavioural and market design effects. Models are estimated separately as daily time-series of the 48 half-hourly trading periods. All coefficients exhibit substantial intra-day variation, relating to the heterogeneity of operating plants and market design aspects. This reveals a market responding to economic fundamentals and plant operating properties, with learning and emergent financial characteristics, as well as some strategic manipulation of capacity, most effectively exercised by the more flexible plants. Using regime-switching parameters, the effects of capacity margin and inter-day ...

Energy Technology Data Exchange (ETDEWEB)

Cell voltage monitoring (CVM) systems are essential for the operation of fuel cell stacks and some battery systems, in the field as well as in the laboratory, because they allow the diagnosis and correction of problems that would otherwise go unnoticed and cause impaired performance or even permanent damage. A robust, safe, and low-cost design for a CVM unit is presented, using electromechanical relays as multiplexing switches. Some examples from the application of the unit on the University of Delaware's fuel cell battery hybrid buses are presented, including its use in automatically correcting anode flooding and diagnosing air channel blockage. (author)

International Nuclear Information System (INIS)

This paper presents a novel organization of switch capacitor charge pump circuits based on voltage doubler structures. Each voltage doubler takes a DC input and outputs a doubled DC voltage. By cascading voltage doublers the output voltage increases up to 2 times. A two-phase voltage doubler and a multiphase voltage doubler structures are discussed and design considerations are presented. A simulator working in the Q-V realm was used for simplified circuit level simulation. In order to evaluate the power delivered by a charge pump, a resistive load is attached to the output of the charge pump and an equivalent capacitance is evaluated. To avoid the short circuit during switching, a clock pair generator is used to achieve multi-phase non-overlapping clock pairs. This paper also identifies optimum loading conditions for different configurations of the charge pumps. The proposed charge-pump circuit is designed and simulated by SPICE with TSMC ...

Energy Technology Data Exchange (ETDEWEB)

An increasing share of natural gas supplies distributed to residential appliances in the U.S. may come from liquefied natural gas (LNG) imports. The imported gas will be of a higher Wobbe number than domestic gas, and there is concern that it could produce more pollutant emissions at the point of use. This report will review recently undertaken studies, some of which have observed substantial effects on various appliances when operated on different mixtures of imported LNG. While we will summarize findings of major studies, we will not try to characterize broad effects of LNG, but describe how different components of the appliance itself will be affected by imported LNG. This paper considers how the operation of each major component of the gas appliances may be impacted by a switch to LNG, and how this local impact may affect overall safety, performance and pollutant emissions.

International Nuclear Information System (INIS)

Purpose: To secure the reactor operation safety by the provision of a fluid pressure detecting section for control rod driving fluid and a control rod interlock at the midway of the flow pass for supplying driving fluid to the control rod drives. Constitution: Between a driving line and a direction control valve are provided a pressure detecting portion, an alarm generating device, and a control rod inhibition interlock. The driving fluid from a driving fluid source is discharged by way of a pump and a manual valve into the reactor in which the control rods and reactor fuels are contained. In addition, when the direction control valve is switched and the control rods are inserted and extracted by the control rod drives, the pressure in the driving line is always detected by the pressure detection section, whereby if abnormal pressure is resulted, the alarm generating device is actuated to warn the abnormality and the control rod inhibition ...

Science.gov (United States)

... switching off all the pixels causes all the spectrum lines to disappear (top of Figure 6), next, that switching off one ... Acousto-optic spectrum analyser ...

Energy Technology Data Exchange (ETDEWEB)

We present the recent results of our research on the high power ultra-fast silicon RF switches. This switch is composed of a group of PIN diodes on a high purity silicon wafer. The wafer is inserted into a cylindrical waveguide under TE{sub 01} mode, performing switching by injecting carriers into the bulk silicon. Our current design uses a CMOS compatible process and the device was fabricated at SNF (Stanford Nanofabrication Facility). 300 ns switching time has been observed, while the switching speed can be improved further with 3-D device structure and faster driving circuit. Power handling capacity of the switch is at the level of 10 MW. The switch was designed for active X-band RF pulse compression systems--especially for NLC, but it is also possible to be modified for other applications and other frequencies.

Energy Technology Data Exchange (ETDEWEB)

Two major developments have given impetus to wider adoption of variable-speed turbine/generators in hydroelectric plants, both essentially environmental: (1) the need for stream-bed stability below river dams, and (2) the need to minimize fish damage. Also, the need to stabilize pumped-storage and generating efficiencies to match extreme changes in head levels has been a driving force. Variable-speed operation in hydro applications is relatively new to North America. In other parts of the world, it has been used in pumped-storage plants since 1971. In the US, and increasing potential exists for variable-speed hydro, considering the 30 pumped-storage plants already in operation and several river plants struggling with high head fluctuations--including four at stations operated by the Bonneville Power Administration. Several modifications to hydro-plant hardware and operating procedures are actively being ...

KoreaScience (Korea)

Full Text Available

Science.gov (United States)

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Energy Technology Data Exchange (ETDEWEB)

In the rf-driven free-electron laser (FEL) at the Los Alamos National Laboratory, there are two pulsed-power rf modulators as sources for two tandem, side-coupled 20-MeV linear accelerators. The rf power used to control the cavity fields is supplied by two 5.5-MW modulating anode klystrons operating at a center frequency of 1300.2 MHz. The modulation of the 125 kV klystron is achieved by using a triode switch tube that provides a pulse width up to 300 ..mu..s and a pulse repetition rate up to 10 Hz. This paper describes the present configuration of these two duplicate systems and presents plans for meeting the requirements of future rf FEL experiments at Los Alamos. 12 refs., 5 figs.

Energy Technology Data Exchange (ETDEWEB)

An apparatus for non-invasively inspecting an object, such as an item of luggage, for explosives material is described. It comprises a multi-channel thermal neutron inspection system having a plurality of neutron irradiation chambers. Simultaneous operation of several channels increases the maximum system throughput several times. Each chamber has a lithium neutron source which is stimulated to neutron production by a proton beam. Beam switching magnets are energised by pulsing to divert a common proton beam to each source in turn. The initial beam is generated by a radio frequency quadrupole accelerator. The advantages of this system are very low residual source activity and controllable neutron production thereby minimising safety hazards. The irradiation chamber may contain several different gamma ray detectors to identify the elements present in explosives material. In addition, a neutron radiography imaging means may be employed to ...

Science.gov (United States)

For the efficient operation of a cavity ringdown spectroscopy (CRDS) system utilized with a continuous-wave (cw) laser, we numerically analyze the coupling efficiency of a cw laser to a ringdown cavity in terms of changes in the scanning rate, the laser linewidth, and the mirror reflectivity. We also demonstrate a new simple design for a CRDS system that can produce a CRDS signal with only a piezoelectric transducer (PZT), without the acousto-optic modulator that is usually adopted to switch off the cw laser beam that enters the cavity. Furthermore, we investigate the feasibility of the cw CRDS technique with a fast-scanning PZT by recording a CRDS spectrum of acetylene overtones. The detection sensitivity that corresponds to the noise-equivalent absorption is found to be approximately 3 x 10(-9)/cm. PMID:18305817

International Nuclear Information System (INIS)

The concept of forestry-service enterprise used in the joint study (1997-7999) by the TTS-Institute and the Finnish Forest Research Institute (Metla) refers to enterprises and co-operatives (including forest workers operating as entrepreneurs) offering services in the fields of silviculture, basic forest improvement, planning and wood-harvesting sector. Companies practicing large-scale wood-conversion and traditional forestry-machine and road haulage contractors are not included in this approach. It can be estimated that there is a total of 450 such entrepreneurs in the country Those engaged in only a minor degree in providing forestry services are not included in the figure. The nation-wide research material was collected in the form of a mail questionnaire addressed to forestry-service entrepreneurs (n=320) in the spring of 1998. Almost all forestry-service entrepreneurs provide timber felling as a service. More than half of them do planting, ...

Energy Technology Data Exchange (ETDEWEB)

We report the performance of a micro gas turbine on biomass producer gas and mixtures of biomass producer gas with natural gas. The micro gas turbine delivers full power on gas mixtures with a heating value of at least 15 MJ/Nm{sup 3}. For gas of lower heating value, the maximum fuel gas flow limits the attainable power. The lower limit for stable operation is about 8 MJ/Nm{sup 3}. The gross efficiency of the micro gas turbine depends on output power but not on the gas heating value, within our measurement accuracy. Above 70% of full power, emissions of CO and NO are 40 and 10 times lower than those of a gas engine of similar size. At part load below 70% of full power, the micro gas turbine burner switches to a different operating mode which produces higher CO and NO levels, but still significantly below those of a gas engine.

International Nuclear Information System (INIS)

A two module electron beam source operating over a wide range of output parameters has been designed and fabricated to be used in conjunction with a pair of electron beam sustained CO_2 lasers. Each module comprised a grid-controlled thermionic electron beam gun including a compact grid pulser for control of the electron beam, a 250 kV thyratron switched modulator for acceleration of the electron beam, a 1 kHz filament heater and a complex computerized control system. The system was designed to reliably produce 45 #mu#s wide electron pulses of 150-200 keV energy, operate at repetition rates of 1-10 pps and current densities of 5-20 mA/cm"2. Additional parameters are listed. The high voltage cathode assembly employs 132 thoriated tungsten filaments distributed over the area of the 250 cm x 10 cm output window. The cathode assembly including the control grids is supported by two high voltage ceramic bushings in a stainless ...

International Nuclear Information System (INIS)

The Fast Flux Test Facility (FFTF) is a liquid-metal-cooled test reactor located on the Hanford Site. The FFTF is the only reactor of this type designed and operated with the intent of meeting the licensing requirements of the Nuclear Regulatory Commission (NRC). Unique characteristics of the FFTF that present special challenges related to leak rate testing include thin wall containment vessel construction, cover gas systems that penetrate containment, and a low-pressure design basis accident. The successful completion in 1986 of the third FFTF Integrated Leak Rate Test (ILRT) five days ahead of schedule and 10% under budget was a major achievement for the Westinghouse Hanford Company. The success of this operational safety test was due in large part to a special local area network (LAN) of three IBM PC/XT computers that monitored the sensor data, calculated the containment vessel leak rate, and displayed test results. The multiple computer ...

UK PubMed Central (United Kingdom)

DEXD/H-box RNA helicases couple ATP hydrolysis to RNA remodeling by an unknown mechanism. We used x-ray crystallography and biochemical analysis of the human DEXD/H-box...Full Text Available

Science.gov (United States)

... Abstract : MANY THIN FILM ACOUSTO-OPTIC INTERACTION EXPERIMENTS FOR ... CONVERTERS, AND FOR FAST SWITCHES HAVE BEEN ...

Science.gov (United States)

... the application of an acousto- optical tunable filter ... Couplers for Large Switch-Array Applications ... Symmetric Integrated Optic X Junction," Electronics ...

Science.gov (United States)

... Acousto-optic programmable dispersive filters (AOPDF) have been developed for optical signal processing, polarization switching in lasers, and ...

KoreaScience (Korea)

Full Text Available

British Library Electronic Table of Contents (United Kingdom)

Resistive switching memory is a very promising technology for emerging nonvolatile memory applications. Generally, the switching behavior is triggered by a sweep or pulse voltage. In this paper, a charged capacitor is proposed to be used as the external electrical source to program a resistive switching element. From theoretical analyses based on a set behavior model, the capacitor approach can program the device efficiently. Compared with sweep or pulse mode, capacitor driving method can greatly reduce over-programming after the set event, and thus improve the resistance uniformity. The experimental results performed on Cu/ZrO2:Cu/Pt device support this conclusion quite well. The proposed methodology has great value for achieving a reliable resistive switching, which is important for high...

Energy Technology Data Exchange (ETDEWEB)

We report the performance of a commercial recuperated micro gas turbine on biomass producer gas and mixtures of biomass producer gas with natural gas. The biomass producer gas, obtained by gasification at 850{sup o}C with air at atmospheric pressure, contains about 7% H2, 17% CO, 15% CO2, 4% CH4, 2% other hydrocarbons, 2% H2O, and a balance of N2 and Ar from air. It has a net heating value of about 6 MJ/(Nm{sup 3}). The micro gas turbine delivers full power (30 kW{sub e}) on gas mixtures with a net heating value of at least 15 MJ/(Nm{sup 3}). For gas of lower heating value, the maximum fuel gas flow allowed by the fuel control unit limits the attainable power. At reduced power, the lower limit for stable operation is a net heating value of about 8 MJ/(Nm{sup 3}). The gross efficiency of the micro gas turbine depends on the output power but not on the gas heating value, within our estimated measurement accuracy of about 2%. Above 70% of full power, NO emission is 5 ...

Energy Technology Data Exchange (ETDEWEB)

The latest electronic circuit technology that can be used for the electric railway traction system fed by an AC/DC dual power line was developed. This system consists of reverse conducting GTO thyristors, microprocessors, and DSP`s. In the AC power supply line section, the line converter is controlled by PWM technology to secure a high power factor and reduce the higher harmonic generation of an input current as far as possible. The line converter and motor converter use reverse conducting GTO thyristors. Since these converters are cooled using a heat pipe cooler, they are reduced in size and weight. The electric grounding point of the main power circuit is set to the negative side of the DC line for AC and DC line sections. Therefore, the AC/DC selector switch was simplified in structure. Moreover, the DC input for the auxiliary power supply can be obtained from multiple line converters using diodes. As the result of the actual operational ...

Energy Technology Data Exchange (ETDEWEB)

Relativistic electron beams are used for generating high power microwaves. These microwave sources require electron beam generators spanning significant ranges in voltage and impedance. The pulsed power technology used to generate these electron beams is presented. Electron beam generators that produce beams with pulse durations in the 10 ns to 100 ns regime consist of an energy storage section, pulse shaping section, and an electron beam diode. The energy storage section is either a Marx generator or capacitor bank-pulsed transformer. The pulse shaping is done with high-voltage transmission lines. The electron beam diode is usually a cold-cathode, space-charge-limited flow device. For longer pulses (approx.1 ..mu..s) the energy storage and pulse shaping can be combined. Lumped-element pulsed-forming networks (PFN) can be designed to produce the desired pulse shape. The Marx generator becomes one of the elements of the PFN. Alternatively, a low voltage PFN followed by a highly coupled ...

International Nuclear Information System (INIS)

This paper introduces a robust searching hybrid evolutionary algorithm to solve the multi-objective Distribution Feeder Reconfiguration (DFR). The main objective of the DFR is to minimize the real power loss, deviation of the nodes' voltage, the number of switching operations, and balance the loads on the feeders. Because of the fact that the objectives are different and no commensurable, it is difficult to solve the problem by conventional approaches that may optimize a single objective. This paper presents a new approach based on norm3 for the DFR problem. In the proposed method, the objective functions are considered as a vector and the aim is to maximize the distance (norm2) between the objective function vector and the worst objective function vector while the constraints are met. Since the proposed DFR is a multi objective and non-differentiable optimization problem, a new hybrid evolutionary algorithm (EA) based on the combination of the ...

Energy Technology Data Exchange (ETDEWEB)

Four 10 MW, highly-stabilized power supply modules have been installed at the National High Magnetic Field Laboratory in Tallahassee, FL, to energize water-cooled, resistive, high-field research magnets. The power supply modules achieve a long term current stability if 10 ppM over a 12 h period with a short term ripple and noise variation of <10 ppM over a time period of one cycle. The power supply modules can operate independently, feeding four separate magnets, or two, three or four modules can operate in parallel. Each power supply module consists of a 12.5 kV vacuum circuit breaker, two three-winding, step-down transformers, a 24-pulse rectifier with interphase reactors, and a passive and an active filter. Two different transformer tap settings allow rated dc supply output voltages of 400 and 500 V. The rated current of a supply module is 17 kA and each supply module has a one-hour overload capability of 20 kA. The isolated output ...

Energy Technology Data Exchange (ETDEWEB)

An improved lockout assembly for locking a circuit breaker in a selected off or on position is provided. The lockout assembly includes a lock block and a lock pin. The lock block has a hollow interior which fits over the free end of a switch handle of the circuit breaker. The lock block includes at least one hole that is placed in registration with a hole in the free end of the switch handle. A lock tab on the lock block serves to align and register the respective holes on the lock block and switch handle. A lock pin is inserted through the registered holes and serves to connect the lock block to the switch handle. Once the lock block and the switch handle are connected, the position of the switch handle is prevented from being changed by the lock tab bumping up against a stationary housing portion of the circuit breaker. When the lock pin installed, an ...

Energy Technology Data Exchange (ETDEWEB)

The Segmented Rail Phased Induction Motor (SERAPHIM) is a compact, pulsed linear induction motor (LIM) offering a unique capability for very high speed train propulsion. It uses technology developed for the Sandia coilgun, an electromagnetic launcher designed to accelerate projectiles to several kilometers per second. Both aluminum cylinders and plates were accelerated to a kilometer per second (Mach 3) by passing through a sequence of coils which were energized at the appropriate time. Although this technology was developed for ultra-high velocity, it can be readily adapted to train propulsion for which, at sea level, the power required to overcome air resistance limits the operational speed to a more modest 300 mph. Here, the geometry is reversed. The coils are on the vehicle and the ``projectiles`` are fixed along the roadbed. SERAPHIM operates not by embedding flux in a conductor, but by excluding it. In this propulsion scheme, pairs of ...

Energy Technology Data Exchange (ETDEWEB)

The R and D were carried out of a detecting system for measurement of data on the bottom of geothermal well, data transmission and signal processing, and an analysis system for well drilling trajectory control and well assessment while geothermal well drilling based on the data obtained by the detecting system. The paper reported the results of the technology development in fiscal 1996. In the development of the detecting system, improvement/design were conducted on a mud pulse generator constituting sonde, well bottom signal processing equipment, mode switch and inclined information sensor, and the system equivalent to the actual one was manufactured to conduct a running test at high temperature/pressure. Moreover, a test to confirm heat resistance of electronic parts was made for further improvement in heat resistance of the sonde, in order to obtain the data. In the development of an analysis system, conducted were enhancement of operability ...

International Nuclear Information System (INIS)

This paper shows that a stochastic regime-switching model can represent the volatile behavior of wholesale electricity prices associated with price spikes effectively. The structure of the model is very flexible because the mean prices in the two regimes and the two transition probabilities are functions of the load and/or the implicit reserve margin. Using price data from the single settlement market in PJM (May 1999 to May 2000), the results show that the estimated switching probability from the low to the high regime predicts price spikes well if the reserve margin is measured accurately.

Energy Technology Data Exchange (ETDEWEB)

Non-linear autoregressive Markov regime-switching models are intuitive. Time-series approaches for the modelling of electricity spot prices are frequently proposed. In this paper, such models are compared with an ordinary linear autoregressive model with regard to their forecast performances. The study is carried out using German daily spot-prices from the European Energy Exchange in Leipzig. Four non-linear models are used for the forecast study. The results of the study suggest that Markov regime-switching models provide better forecasts than linear models. (author)

CERN Document Server

We study the all-optical time-control of the strong coupling between a single cascade three-level quantum emitter and a microcavity. We find that only specific arrival-times of the control pulses succeed in switching-off the Rabi oscillations. Depending on the arrival times of control pulses, a variety of exotic non-adiabatic cavity quantum electrodynamics effects can be observed. We show that only control pulses with specific arrival times are able to suddenly switch-off and -on first-order coherence of cavity photons, without affecting their strong coupling population dynamics. Such behavior may be understood as a manifestation of quantum complementarity.

Energy Technology Data Exchange (ETDEWEB)

The authors address the question of the limitations on voltage and current transfer to loads in magnetic storage systems utilizing microsecond conduction time plasma opening switches. They propose that the limitation of performance results from neutral atoms that are not entrained into the ionized material that is driven by the magnetic field of the rising generator current. Evidence in support of this proposition is gathered from experiments performed on the Ace-4 and Hawk generators. They set forth a theory to describe the effect of neutrals on the electrical performance of plasma opening switches. The neutral gas is assumed to be present in the region between the moving plasma mass and the generator, primarily in the region in which the plasma is injected initially. The essential elements of the theory are a weak photoionization source to seed the gas with a low concentration of electrons, and joule heating accompanied by further ionization ...

Science.gov (United States)

... electronic feedback system' connected to a Q switch ... The use of acousto-optic (AO) beam steering devices for BMDO (SDI) applications is very ...

British Library Electronic Table of Contents (United Kingdom)

Multi-fiber WDM networks are becoming the major telecommunication platforms for transmitting exponentially increasing data traffic. While today's networks are mainly providing circuit-switched connections, optical packet-switching technologies have been investigated for years, aiming at achieving more efficient utilizations of network resources. In this paper, we have evaluated, for the first time, the packet-loss performance of multi-fiber optical packet switches (MOPS). Our main contributions are threefold. Firstly, we have proposed simple and accurate analytical models for analyzing packet-loss performance of (i) the most fundamental MOPS configuration, (ii) MOPS equipped with fiber delay lines (FDLs) and (iii) shared wavelength converters (SWCs). Secondly, we have shown that the MOPS n...

Science.gov (United States)

... is a standard in the utility industry which is used to study switching transients on power distribution networks and high-voltage transmission lines. ...

British Library Electronic Table of Contents (United Kingdom)

This study looks for the presence of rational speculative bubbles in Real Estate Investment Trusts (REITs) using unit-root, variance ratio, duration dependence and regime switching regression tests. The regime switching method provides weak evidence of speculative bubble behaviour in both the mortgage and hybrid REITs sectors even though traditional econometric bubble tests do not provide evidence of rational speculative bubbles in all REIT markets. Findings suggest that price movement in mortgage and hybrid REITs may be induced by bubble-like behaviour of investors. This behaviour may be traced to the real estate market bubble. Our results provide evidence that the real estate bubble that started in early 2000 was transmitted into securitized real estate markets. A regime switching model ...

Science.gov (United States)

Photoinduced charge separation reactions form the basis for energy storage processes in both natural and artificial photosynthesis. Moreover, rapid reversible photoinduced electron transfer reactions are a class of photophysical phenomena that can be exploited to develop schemes for optical switching. Examples from each of these fields are discussed.

Energy Technology Data Exchange (ETDEWEB)

This report describes the test of a dynamic phase compensation unit for a wind turbine with directly connected induction generators. The compensation unit is based on thyristor switched capacitors, where conventional wind turbine compensations use mechanical contactors to switch the capacitors. The influence on power quality analysed, and influence on component lifetime is discussed. Besides, simulation models in Matlab/Simulink are presented, including a flicker meter model. (au)

Energy Technology Data Exchange (ETDEWEB)

An electrical circuit testing device is provided, comprising a case, a digital voltage level testing circuit with a display means, a switch to initiate measurement using the device, a non-shorting switching means for selecting pre-determined electrical wiring configurations to be tested in an outlet, a terminal block, a five-pole electrical plug mounted on the case surface and a set of adapters that can be used for various multiple-pronged electrical outlet configurations for voltages from 100 600 VAC from 50 100 Hz.

British Library Electronic Table of Contents (United Kingdom)

Taking both white noise and colored environmental noise into account, a general stochastic logistic model under regime switching is proposed and studied. Sufficient conditions for extinction, nonpersistence in the mean, weak persistence, stochastic permanence and global attractivity are established. The critical number between weak persistence and extinction is obtained. Moreover, some simulation figures are introduced to illustrate the main results.

Energy Technology Data Exchange (ETDEWEB)

Estimates of annual rates of change of fuel switching are constructed using logistic curve models fitted to often sparse historical data on fuel use in the USA. The estimated annual rate of loss of market share of an old fuel is then shown to be correlated with five-year averages of declines in the rate of growth of affected vehicle numbers. Other statistical tests show a positive correlation between five-year average changes in the rate of growth of the vehicle numbers and of macroeconomic activity when the affected vehicles are directly responsible for a large share of that activity. The vehicle types shown to have this effect are locomotives from 1885-1915 and automobiles thereafter. The third set of tests supports an interpretation that the indirect effects of fuel switches are significant and consistent with GNP throughout the 1880-1980 period. It is shown that a pronounced drop in GNP growth occurs at the time when the important fuel ...

Energy Technology Data Exchange (ETDEWEB)

Transmission line faults must be located accurately to allow maintenance crews to arrive at the scene and repair the faulted section as soon as possible. Rugged terrain and geographical layout cause some sections of power transmission lines to be difficult to reach. In the past, a variety of fault location algorithms were introduced as either an add-on feature in protective relays or stand-alone implementation in fault locators. In both cases, the measurements of current and voltages were taken at one terminal of a transmission line only. Under such conditions, it may become difficult to determine the fault location accurately, since data from other transmission line ends are required for more precise computations. In the absence of data from the other end, existing algorithms have accuracy problems under several circumstances, such as varying switching and loading conditions, fault infeed from the other end, and random value of fault resistance. Most of the ...

Energy Technology Data Exchange (ETDEWEB)

The high-purity-oxygen activated sludge process will be used to expand secondary treatment capacity and improve water quality in Santa Monica Bay. The facility is operated by the city of Los Angeles Department of Public Works` Bureau of Sanitation. The overall Hyperion Full Secondary Project is 30% complete, including a new headworks, a new primary clarifier battery, an electrical switch yard, and additional support facilities. The upgrading of secondary facilities is 50% complete, and construction of the digester facilities, the waste-activated sludge thickening facility, and the second phase of the three-phase modification to existing primary clarifier batteries has just begun. The expansion program will provide a maximum monthly design capacity of 19,723 L/s(450 mgd). Hyperion`s expansion program uses industrial treatment techniques rarely attempted in a municipal facility, particularly on such a large scale, including: a user-friendly ...

Energy Technology Data Exchange (ETDEWEB)

A bistable, micromechanical switching device and its buckling stability, heat transfer, and dynamics analyses are summarized. A SEM picture of the device. The buckling element of the microactuator is a U-shaped cantilever ({open_quotes}buckled cantilever{close_quotes} in the picture) consisting of two 0.8 micron-thick polysilicon layers with 0.5 micron-thick oxide insulator sandwiched between them. The 82 micron-long cantilever is buckled by the {open_quotes}tension band{close_quotes} made of 0.5 micron-thick silicon nitride. The snapping action of the microactuator to the down-state (or up-state) is achieved by heating the upper (or lower) polysilicon layer of the buckling cantilever with electric current. Analysis of a snapping action between two buckled states is described. It provides a design framework as well as operation guidelines for the actuator. The buckling stability criterion and the deflection of the buckled cantilever are ...

Energy Technology Data Exchange (ETDEWEB)

We report on the software aspects of the development of a switch-based data acquisition system at Fermilab. This paper describes how, with the goal of providing an ``integrated systems engineering`` environment, several powerful software tools were put in place to facilitate extensive exploration of all aspects of the design. These tools include a simulation package, graphics package and an Expert System shell which have been integrated to provide an environment which encourages the close interaction of hardware and software engineers. This paper includes a description of the simulation, user interface, embedded software, remote procedure calls, and diagnostic software which together have enabled us to provide real-time control and monitoring of a working prototype switch-based data acquisition (DAQ) system.

Energy Technology Data Exchange (ETDEWEB)

A dielectric-wall linear accelerator is improved by a high-voltage, fast rise-time switch that includes a pair of electrodes between which are laminated alternating layers of isolated conductors and insulators. A high voltage is placed between the electrodes sufficient to stress the voltage breakdown of the insulator on command. A light trigger, such as a laser, is focused along at least one line along the edge surface of the laminated alternating layers of isolated conductors and insulators extending between the electrodes. The laser is energized to initiate a surface breakdown by a fluence of photons, thus causing the electrical switch to close very promptly. Such insulators and lasers are incorporated in a dielectric wall linear accelerator with Blumlein modules, and phasing is controlled by adjusting the length of fiber optic cables that carry the laser light to the insulator surface.

International Nuclear Information System (INIS)

Energy harvesting systems stimulate the development of power management for low power consumption applications. Improving the converter efficiency of power management circuits has become a significant issue in energy harvesting system design. This paper presents a variable step-down conversion ratio switched capacitor (SC) DC-DC converter to advance the converter efficiency of charge on the stored capacitor in a wireless monitoring system of orthopedic implants. The converter is designed to work at 1 MHz switching frequency and achieves 15 to 2 V conversion. Measurement results show that the converter efficiency can reach 42% including all circuit power consumption, which is much higher than previous work. (semiconductor integrated circuits)

Science.gov (United States)

In systems of fast decimal counters, there are three problems to be resolved: to study a bistable having a short switching time, to form with the aid of three bistables a circuit divisible by 5, and to normalize the input pulses. The solutions to these problems for the nonsecond scaler are presented. (J.S.R.)

UK PubMed Central (United Kingdom)

Numerical calculations of static, switched, and radiofrequency (RF) electromagnetic (EM) fields considering the geometry and EM properties of the human body are used increasingly in MRI to explain...Full Text Available

Science.gov (United States)

Upon illumination of an optically driven Q-switch 35 over conventional electro- optic, acousto-optic and medium located inside the laser cavity with an ...

CERN Document Server

This paper presents and implements an iterative feedback design algorithm for stabilisation of discrete-time switched systems under arbitrary switching regimes. The algorithm seeks state feedback gains so that the closed-loop switching system admits a common quadratic Lyapunov function (CQLF) and hence is uniformly globally exponentially stable. Although the feedback design problem considered can be solved directly via linear matrix inequalities (LMIs), direct application of LMIs for feedback design does not provide information on closed-loop system structure. In contrast, the feedback matrices computed by the proposed algorithm assign closed-loop structure approximating that required to satisfy Lie-algebraic conditions that guarantee existence of a CQLF. The main contribution of the paper is to provide, for single-input systems, a numerical implementation of the algorithm based on iterative approximate common eigenvector ...

Energy Technology Data Exchange (ETDEWEB)

Two types of switched electrode electronics beam position monitors are in use at Jefferson Lab. Together they provide accurate beam position to the control system for beam intensities between 50 nA and 2 mA. One version, called the linac style, has a switching frequency of 125 kHz. The other, called the transport type, has a switching frequency of 7 kHz. The basic system provides information to the control system at a 1 Hz update rate. The systems are regularly used to measure the AC component of beam position and energy as well as suppress this motion as part of a fast feedback system. Position data produced by the system are also acquired on an event by event basis as part of the nuclear physics program in two of the experimental halls. This paper will focus on the AC characteristics of the system. These characteristics are affected by analog filter frequencies and a time delay between the measurement of the positive ...

Science.gov (United States)

... Steady State 16.0-28.0 5.05 to 5.36 0 Key switch turned on. ... version may have been the better choice since the acousto-optic modulator also ...

UK PubMed Central (United Kingdom)

Escherichia coli infection of the endometrium causes uterine disease after parturition and is associated with prolonged luteal phases of the ovarian cycle in cattle. Termination...Full Text Available

Energy Technology Data Exchange (ETDEWEB)

Results are reported of photoemission studies using laser pulses of 10 ps duration and 4.66 eV photon energy on metal cathodes. These included thin wires, flat surfaces and an yttrium cathode with a grainy surface. The measurements of current density and quantum efficiency under low and high surface fields indicate that field assisted efficiencies exceeding 0.1% and current densities exceeding 10/sup 5/ A/cm/sup 2/ are obtainable. The results are compared to the requirements of switch power applications. 24 refs., 13 figs., 1 tab.

Energy Technology Data Exchange (ETDEWEB)

The magnetoresistance in an FeNi submicron-structure comprising two wires of 80 and 200 nm in width connected in series was measured at 77 K. When the external magnetic field was applied parallel to the wire axis, two switching fields corresponding to the distinct coercive force of the two wires were observed. When the external magnetic field was applied at an angle of {theta}>30 deg. to the wire axis one switching field was observed, indicating simultaneous magnetization reversal in both wires. This indicates that the domain-wall trapping around the joint can be controlled systematically in terms of the direction of the external magnetic field.

British Library Electronic Table of Contents (United Kingdom)

As is well documented, subprime mortgage markets carried significant default risk. This paper investigates the relationship between default risk premium, stock market conditions and macroeconomic variables during the financial crisis. Using iTraxx Japan Credit Default Swap (CDS) index spreads covering the period from March 2006 to November 2009, we employ a time-varying dynamic factor model with Markov regime switching to generate regime probabilities for default risk. We analyze the sensitivity of default risk premium changes to stock market conditions and macroeconomic variables by using two-state Markov switching models: a crisis regime sparked by rising loan defaults in the sub-prime mortgage market, and a non-crisis regime. We found strong evidence that the relationship between defaul...

DEFF Research Database (Denmark)

This paper presents a new and simple method for sensorless control of matrix converter drives using a power flowing to the motor. The proposed control algorithm is based on controlling the instantaneous real and imaginary powers into the induction motor. To improve low-speed sensorless performance, the nonlinearities of a matrix converter drive such as commutation delays, turn-ON and turn-OFF times of switching devices, and on-state switching device voltage drop are modeled using a PQ power transformation and compensated using a reference power control scheme. The proposed sensorless control method is applied for the induction motor drive using a 3 kW matrix converter system. Experimental results are shown to illustrate the feasibility of the proposed strategy. Udgivelsesdato: September

Energy Technology Data Exchange (ETDEWEB)

The dielectric wall accelerator (DWA) system being developed at the Lawrence Livermore National Laboratory (LLNL) uses fast switched high voltage transmission lines to generate pulsed electric fields on the inside of a high gradient insulating (HGI) acceleration tube. High electric field gradients are achieved by the use of alternating insulators and conductors and short pulse times. The system is capable of accelerating any charge to mass ratio particle. Applications of high gradient proton and electron versions of this accelerator will be discussed. The status of the developmental new technologies that make the compact system possible will be reviewed. These include, high gradient vacuum insulators, solid dielectric materials, photoconductive switches and compact proton sources.

CERN Document Server

We study a generalization of the Skyrme model with the inclusion of a sixth-order term and a generalized mass term. We first analyze the model in a regime where the nonlinear sigma and Skyrme terms are switched to zero which leads to well-behaved analytical BPS-type solutions. Adding contributions from the rotational energy, we reproduce the mass of the most abundant isotopes to rather good accuracy. These BPS-type solutions are then used to compute the contributions from the nonlinear sigma and Skyrme terms when these are switched on. We then adjust the four parameters of the model using two different procedures and find that the additional terms only represent small perturbations to the system. We finally calculate the binding energy per nucleon and compare our results with the experimental values.

Energy Technology Data Exchange (ETDEWEB)

The switching behavior of magnetic patterns prepared by ion irradiation was investigated. Co/Pt multilayers with perpendicular anisotropy and large out-of-plane coercivities 5-6 kOe were grown on electron transparent SiN windows. Regularly spaced 1 micron sized regions, were magnetically pattered via ion beam irradiation through a stencil mask. Lorentz TEM was used to observe in-situ magnetization reversal processes of irradiated regions under well-defined applied magnetic fields. When the in-plane field was increased, domain wall motion was observed, resulting in the alignment of the patterns with the direction of the applied field. The switching mechanism of the in-plane patterns was by domain wall motion.

Energy Technology Data Exchange (ETDEWEB)

The paper reports the results of the studies performed at the Electric Research Center of ENEL (Italian National Electricity Board) in the field of compacting high voltage transmission lines, from the point of view of dielectric and corona noise constraints. The results of switching impulse withstand voltage tests, performed on typical compact line insulation configurations, are given and optimization criteria of such insulation configurations in relation to switching impulse are outlined. The constraints regarding surface withstand voltage in polluted conditions of the above insulations are analyzed and the possibility of reducing their dimensions by using unconventional insulation materials is considered. Finally, evaluations of corona noise in the case of optimization of the line encumbrance from the point of view of dielectric constraints are given.

J-STORE (Japan)

Full Text Available

International Nuclear Information System (INIS)

A new formulation of the theory of tachyons is developed using the same two postulates as in special relativity. Use is made of a 'switching principle' to show how tachyons automatically obey the laws of conservation of energy, momentum and electric charge. Tachyonic mechanics is further developed by a consideration of tachyonic rods and clocks. There follows a discussion of the conservation of electric charge and the apparent visual appearance of a tachyonic cube. 19 refs., 9 figs.

CERN Document Server

We provide an analytic study of the dynamics of semiconductor lasers with injection (pump) of spin-polarized electrons, previously considered in the steady-state regime. Using complementary approaches of quasi-static and small signal analyses, we elucidate how the spin modulation in semiconductor lasers can improve performance, as compared to the conventional (spin-unpolarized) counterparts. We reveal that the spin-polarized injection can lead to an enhanced bandwidth and desirable switching properties of spin-lasers.

CERN Multimedia

Joanna Geary joined a Birmingham University team of scientists working on the project in Geneva. Simond Hadley took the pictures. "The most exciting thing of all" says professor Peter Watkins with a smile, "is we have absolutely no idea what will happen until we switch it on."

CERN Document Server

We report an observation of a delayed all-optical routing/switching phenomenon based on ultraslow group velocity of light via nondegenerate four-wave mixing processes in a defected solid medium. Unlike previous demonstrations of enhanced four-wave mixing processes using the slow light effects, the present observation demonstrates a direct retrieval of the resonant Raman-pulse excited spin coherence into photon coherence through coherence conversion processes.

Science.gov (United States)

An integrated mirrorless bistable optical device based on the Mach-Zehnder interferometric optical switch has been proposed and demonstrated experimentally using a Ti:LiNbO3 waveguide. The resulting device is capable of combining more than two of them to realize multifunctional optical devices such as optical multivibrators.

Energy Technology Data Exchange (ETDEWEB)

The objective of the research is first to build a highly parallel processing system using 100 personal computers and an ATM switch. The former is a commodity for computer, while the latter can be regarded as a commodity for future communication systems. Second is to implement parallel relational database management system and parallel data mining system over the 100-PC cluster system. Third is to run decision-support queries typicalto data warehouses, to run association rule mining, and to prove the effectiveness of the proposed architecture as a next generation parallel database/datamining server. Performance/cost ratio of PC is significantly improved compared with workstations and proprietry systems due to its mass production. The cost of ATM switch is also considerably decreasing since ATM is being widely accepted as a communication-on infrastructure. By combining 100 PCs as computing commodities and ATM switch as a ...

CERN Document Server

Families of regimes for discrete control systems are studied possessing a special quasi-controllability property that is similar to the Kalman controllability property. A new approach is proposed to estimate the amplitudes of transient regimes in quasi-controllable systems. Its essence is in obtaining of constructive a priori bounds for degree of overshooting in terms of the quasi-controllability measure. The results are applicable for analysis of transients, classical absolute stability problem and, especially, for stability problem for desynchronized (asynchronous, switching) systems.

Science.gov (United States)

A device for marking and searching for information on a magnetic carrier is described. In order to increase the noise immunity and reliability of the data recording and reading paths, the recording head is included between the amplifier of the clock pulses for the master oscillator and through the amplifier of the code pulses for the logical element unit. The reproduction head is connected through the code pulse shaper-amplifier with a switch which is connected with the display unit, and through another analogous clock pulse amplifier with a multivibrator.

Energy Technology Data Exchange (ETDEWEB)

The conductance in ferromagnetic Ni nano-wire is quantized in units of 2e{sup 2}/h in the absence of magnetic field, while the units switch to e{sup 2}/h in the magnetic field. The fractional units of 0.7e{sup 2}/h and 1.4e{sup 2}/h with and without magnetic field appear under the application of high bias-voltage. The spin polarization and bias-voltage play an important role in the electric conduction.

UK PubMed Central (United Kingdom)

To understand how DEXD/H-box proteins recognize and interact with their cellular substrates, we have been studying Prp28p, a DEXD/H-box splicing factor required for switching the U1 snRNP with the U6...Full Text Available

Science.gov (United States)

... where they discussed Montgomery's failure to pursue Operation Goodwood, ... Operation Goodwood, Montgomery's 18 July attack on Caen ...

Science.gov (United States)

... Then came Montgomery's Operation GOODWOOD in the Caen section. ... the attack during Operation GOODWOOD. The "speed" of ...

Energy Technology Data Exchange (ETDEWEB)

This report introduces a microprocessor system composed of a Z-80 single-board computer controlling a gas-carburizing process. The system has 7 analogical input and output signals 24 switch signal-input and 12 switch signal-output signals, which are applicable for temperature, carbon potential, and mechanical-movement control of multipurpose sealed furnaces, or for mutiple-zone temperature, carbon potential, and mechanical-movement control of continuous gas carburizing furnaces; or for distributed control of pit-type carburizing furnaces. The setpoints of variables, such as treating time, temperature, carbon potential of carburizing period, carbon potential of diffusion period, depth of carburizing layer, P.I.D. etc., are entered by keyboard and stored into memories, and actual values are displayed by digital tubes. Furthermore, the fault of thermocouple, oxygen probe, or infrared CO/sub 2/ analyzer; carbon potential, or temperature exceeding ...

International Nuclear Information System (INIS)

Purpose: To enable safety reactor shut down upon occurrence of an abnormal excess pressure in a hydraulic control unit. Constitution: The actuation pressure for a pressure switch that generates a scram signal is set lower than the release pressure set to a pressure release valve. Thus, if the pressure of nitrogen gas in a nitrogen container increases such as upon exposure of the hydraulic control unit to a high temperature, the pressure switch is actuated at first to generate the scram signal and a scram valve is opened to supply water at high pressure to control rod drives under the driving force of the nitrogen gas at high pressure to rapidly insert the control element into the reactor and shut down it. If the pressure of the nitrogen gas still increases after the scram, the pressure release valve is opened to release the nitrogen gas at high temperature to the atmosphere. Since the scram is attained before the actuation of the pressure ...

Science.gov (United States)

The GTPases comprise a protein superfamily of highly conserved molecular switches adapted to many diverse functions. These proteins are found in all domains of life and often perform essential roles in fundamental cellular processes. Analysis of data from genome sequencing projects demonstrates that bacteria possess a core of 11 universally conserved GTPases (elongation factor G and Tu, initiation factor 2, LepA, Era, Obg, ThdF/TrmE, Ffh, FtsY, EngA and YchF). Investigations aimed at understanding the function of GTPases indicate that a second conserved feature of these proteins is that they elicit their function through interaction with RNA and/or ribosomes. An emerging concept suggests that the 11 universal GTPases are either necessary for ribosome function or transmitting information from the ribosome to downstream targets for the purpose of generating specific cellular responses. Furthermore, it is suggested that progenitor GTPases were early regulators of RNA ...

Energy Technology Data Exchange (ETDEWEB)

Compact dielectric wall (DWA) accelerator technology is being developed at the Lawrence Livermore National Laboratory. The DWA accelerator uses fast switched high voltage transmission lines to generate pulsed electric fields on the inside of a high gradient insulating (HGI) acceleration tube. Its high electric field gradients are achieved by the use of alternating insulators and conductors and short pulse times. The DWA concept can be applied to accelerate charge particle beams with any charge to mass ratio and energy. Based on the DWA system, a novel compact proton therapy accelerator is being developed. This proton therapy system will produce individual pulses that can be varied in intensity, energy and spot width. The system will be capable of being sited in a conventional linac vault and provide intensity modulated rotational therapy. The status of the developmental new technologies that make the compact system possible will be reviewed. These include, high ...

CERN Document Server

The aim of this work was to study the possibility of producing a fast switching optical thin film device to react to laser radiation in the visible/near infrared region of the spectrum. The switching mechanism was to be thermally driven. A computer program was written to enable the effects of changes of the refractive index of a component of a multilayer thin film stack to be modelled. Attempts to use the phase transition in vanadium dioxide were unsuccessful because, in the spectral region of interest, the 'open-state' absorption was too great. A class of materials known as 'the bronzes' was identified as being potentially useful. Attempts were made to produce thin films of bronze compounds of vanadium, tungsten and molybdenum by the techniques of conventional thermal evaporation and laser ablation for further studies. The former technique appeared to suffer from problems of decomposition of the source material. The latter technique showed ...

Energy Technology Data Exchange (ETDEWEB)

A system is claimed for multiplexing or demultiplexing pulsed laser radiation having an acousto-optical device which is electrically controlled to switch a common path of high pulse rate laser radiation between a plurality of spatially distinct paths for relatively lower pulse rate laser radiation at which the pulses are sequenced according to a predetermined time pattern. The acousto-optical element typically includes a Bragg cell which is electrically driven by a set of distinct frequencies, causing deflection of radiation passing therethrough at a predetermined set of angles whereby pulsed radiation on a single path may be distributed onto the plural separate paths or radiation on plural separate paths of time-sequenced pulses of radiation can be combined into a single path of augmented pulse rate. The control of the acousto-optical element may be provided by selectively switching the output of a plurality of fixed frequency oscillators of ...

Energy Technology Data Exchange (ETDEWEB)

A novel compact CT-guided intensity modulated proton radiotherapy (IMPT) system is described. The system is being designed to deliver fast IMPT so that larger target volumes and motion management can be accomplished. The system will be ideal for large and complex target volumes in young patients. The basis of the design is the dielectric wall accelerator (DWA) system being developed at the Lawrence Livermore National Laboratory (LLNL). The DWA uses fast switched high voltage transmission lines to generate pulsed electric fields on the inside of a high gradient insulating (HGI) acceleration tube. High electric field gradients are achieved by the use of alternating insulators and conductors and short pulse times. The system will produce individual pulses that can be varied in intensity, energy and spot width. The IMPT planning system will optimize delivery characteristics. The system will be capable of being sited in a conventional linac vault and provide intensity ...

International Nuclear Information System (INIS)

Superconducting magnetic and inertial energy pulsed power systems are being developed for future theta-pinch, Tokamak, and laser fusion applications. The short term requirements for these applications are discussed along with present day accomplishments. Areas requiring a research and development effort are examined in detail. Subjects discussed include stresses, energy loss factors, conductor metallurgy, cryogenic requirements, and electrical limitations of superconducting magnetic storage systems; costs, applications, and present technology of homopolar systems; and switching problems associated with both systems.

International Nuclear Information System (INIS)

Many countries are liberalizing their energy markets. Participants in these markets are exposed to market risk due to the characteristics of electricity price dynamics. Electricity prices are known to be mean-reverting very volatile and subject to frequent spikes. Models that describe the dynamics of electricity prices should incorporate these characteristics. In order to capture the price spikes, many researchers have introduced stochastic jump processes, but we argue and show that this specification might lead to potential problems with specifying the true amount of mean-reversion within the process. In this paper, we propose a regime-switching model that models price spikes separated from normal mean-reverting prices.

Energy Technology Data Exchange (ETDEWEB)

New technologies make multi-megajoule glass lasers economically feasible. Laser architectures using harmonic switchout, target plane holographic injection, phase conjugation, continuous apodization and higher amplifier efficiencies have been devised. A plan for a multi-megajoule laser which can be built for an acceptable cost relies on manufacturing economies of scale and the demonstration of the new technologies presented here. These include continuous pour glass production, rapid harmonic crystal growth, switching of large blocks of power using larger capcaitors packed more economically and by using large identical parts counts.

Energy Technology Data Exchange (ETDEWEB)

This book discusses the progress and problems of current interest in gaseous dielectrics and their use, with special emphasis on insulation in high-voltage transmission lines and substations. Topics covered include: basic physics of gaseous dielectrics; basic mechanisms; gas decomposition, reactions and toxicity; diagnostics and field probes; gases and mixtures for GIS transformers and circuit breakers; gaseous media for discharge chemistry and etching/corona; gas engineering for pulsed power and switching; gas breakdown under steep-fronted voltages; new developments in gas-insulated equipment and gas handling; gas/insulator interface/flashover; and quality control in testing gas-insulated equipment. Contains approximately 85 papers.

Energy Technology Data Exchange (ETDEWEB)

In dual-energy projection radiography with double exposures, rapid energy switching is mandatory to eliminate motion artifacts, but it is costly for use in a clinical environment. We developed a system with practical exposure intervals at reasonable cost by modifying a condenser-type X-ray generator. A commercially available system for digital radiography (Fuji Computed Radiography, FCR) was used to subtract images. This report dealt with technical factors to obtain adequate kV and mAs settings in this technique.

International Nuclear Information System (INIS)

A compact medical synchrotron is being developed which aims to promote the advanced radiotherapy based on the accelerator. As it is small-sized, a high field dipole magnet of 3 T at 200 kA is used. It is excited by the discharge current of the capacitor bank of which waveform is half sinusoidal. To provide with the flat field of 10 - 20 #mu#s duration for the multi-turn injection an additional power supply is developed. For the quadrupole magnet a 100 kHz switch-mode power supply is adopted as it requires the fine tuning and accurate field tracking to the dipole field. (author)

British Library Electronic Table of Contents (United Kingdom)

Let Y be a nonnegative random variable with mean?? and finite positive variance ? 2, and let Y s , defined on the same space as Y, have the Y size-biased distribution, characterized by Formula Not Shown Under a variety of conditions on Y and the coupling of Y and Y s , including combinations of boundedness and monotonicity, one sided concentration of measure inequalities such as Formula Not Shown hold for some explicit A and B. The theorem is applied to the number of bulbs switched on at the terminal time in the so called lightbulb process of Rao et?al. (Sankhy? 69:137?161, 2007).

CERN Document Server

Based on the exact results obtained by Bethe ansatz, we demonstrate the existence of stable bound pair (BP) wave packet in Bose Hubbard model with arbitrary on-site interaction U. In large-U regime, it is found that an incoming single-particle (SP) can coherently pass through a BP wave packet and leave a coherent shift in the position of it. This suggests a simple scheme for constructing a BP charge qubit to realize a quantum switch, which is capable of controlling the coherent transport of one and only one photon in a one-dimensional waveguide.

British Library Electronic Table of Contents (United Kingdom)

This paper develops a model of nonlinear pricing with competition. The novel element is that each consumer's willingness to pay for quality is private information and is allowed to differ across brands. The consumer's preferences are represented by a multidimensional type containing the marginal value of quality for different products. Buyers with high willingness to pay for quality also display strong preferences for particular brands, and require higher discounts in order to switch away from their favorite product. Therefore, competition is fiercer for buyers with lower tastes for quality, and hence more elastic demands. This is in sharp contrast to earlier models in which competition is fiercer for higher-taste, more valuable buyers. In equilibrium, firms either compete intensively for ...

International Nuclear Information System (INIS)

Natural cooling conditions of the nuclear fuel in the channel type reactor after its shut down are commonly determined with relatively high uncertainty. This is not only to he lack of adequate measurements of thermal parameters i.e. the residual power generation, the coolant flow and temperatures, but also due to indeterminate model of convection mechanism. The numerical simulation of natural convection in multitube fuel assembly in the fuel channel leads to various convection modes including evidently chaotic behaviour. To determine the real cooling conditions in the MARIA research reactor a series of experiments has been performed with fuel assembly equipped with a set of thermocouples. After some forced cooling period (the shortest was half an hour after the reactor shut down) the reactor was left with the only natural convection. Two completely different cooling modes have been observed. The MARIA core consists of series of individual fuel channel and so called bypasses, ...

Energy Technology Data Exchange (ETDEWEB)

This paper presents a stochastic model and estimation procedure for analyzing the failure process of a repairable system. We consider repairable systems whose successive interfailure times reveal a significant dependence while showing an insignificant trend. Neither the renewal process nor the non-homogeneous Poisson process are adequate for modeling such failure processes. Especially when the interfailure times show a cyclic pattern, we may consider a switching of the regimes (states) governing the lifetime distribution of the system. We propose a Markov switching model describing the failure process for such a case. The model postulates that a finite number of states governs the distinct lifetime distributions, and the state makes transitions according to a discrete-time Markov chain. Each of the distinct lifetime distributions represents a failure type that may change after successive repairs. Our model generalizes the mixture model by ...

Science.gov (United States)

... and the Commonwealth forces launched Operation GOODWOOD in an attempt to break through the German lines. In the ...

Energy Technology Data Exchange (ETDEWEB)

This is a presentation on Human Factors in reactor operations. It discusses issues that deal with power plant operations, training and design, operational effectiveness and safety, supporting people to achieve effective and error free performance.

Science.gov (United States)

Special Operations Forces (SOF) within a Joint Task Force are controlled by a Joint Special Operations Task Force (JSOTF). Presently, JSOTF headquarters are formed around the core of the Theater Special Operations Command (TSOC), a service SOF headquarter...

Energy Technology Data Exchange (ETDEWEB)

A method and system for enhancing the transient stability of an intertied three-phase electric power generating system. A set of power exporting generators (10) is connected to a set of power importing generators (20). When a transient cannot be controlled by conventional stability controls, and imminent loss of synchronism is detected (such as when the equivalent rotor angle difference between the two generator sets exceeds a predetermined value, such as 150 degrees), the intertie is disconnected by circuit breakers. Then a switch (30) having a 120-degree phase rotation, or a circuit breaker having a 120-degree phase rotation is placed in the intertie. The intertie is then reconnected. This results in a 120-degree reduction in the equivalent rotor angle difference between the two generator sets, making the system more stable and allowing more time for the conventional controls to stabilize the transient.

International Nuclear Information System (INIS)

In this paper, steady-state isotopic transient kinetic analysis (SSITKA) is used to study two model reactions, CO oxidation and CO-NO reactions, on a typical formulation of a three-way auto-catalyst. Under steady-state conditions, abrupt switches in the isotopic composition of CO ("1"2C"1"6O/"1"3C"1"8O) were carried out to produce isotopic transients in both labeled reactants and products. Along with the determination of the average surface lifetimes and concentrations of reaction intermediates, an analysis of the transient responses along the carbon reaction pathway indicated that the distribution of active sites for the formation of CO_2 was bimodal for both reactions. Furthermore, relatively few surface sites contributed to the overall reaction rate.

British Library Electronic Table of Contents (United Kingdom)

Abstract: The current financial crisis has now led most major central banks to rely on quantitative easing. The unique Japanese experience of quantitative easing is the only experience which enables us to judge this therapy's effectiveness and the timing of the exit strategy. In this paper, we provide a new empirical framework to examine the effectiveness of Japanese monetary policy during the ''lost'' decade and quantify the effect of quantitative easing on Japan's activity and prices. We combine advantages of Markov-switching VAR methodology with those of factor analysis to establish two major findings. First, we show that the decisive change in regime occurred in two steps: it crept out from late 1995 and established itself durably in February 1999. Second, we show for the first time th...

British Library Electronic Table of Contents (United Kingdom)

The cover picture shows the fertile combination of synthetic chemistry and experimental physics, both permanently making central contributions to hot scientific topics in spite of being classical scientific disciplines with long-standing traditions. The displayed scientist struggles with the synthesis of cruciform structures (displayed on the black board) for single-molecule-transport investigations in a mechanically controlled break junction setup (sketched in the inset at the upper right corner). More information on the design and synthesis of the cruciform structures, such as their immobilization experiments, is found in the article by M. Calame, M. Mayor et al. on p. 833 ff. Serafin Pazdera is greatly acknowledged for the cover artwork.

International Nuclear Information System (INIS)

Yttria stabilized zirconia (YSZ) with 8 mol% Y was deposited by reactive magnetron sputtering onto oxidized (100) silicon substrates. It was possible to switch film texture from (111) to (200) by applying a strong RF substrate bias. Transmission electron microscopy showed that the film deposited under bias is porous and exhibits nanoscaled grains, whereas the film deposited without bias is dense and columnar. The ionic conductivity as a function of temperature revealed an activation energy of 1.04 eV. The mechanical stress could be tuned to low values by thermal post-annealing. Using the dense (111) film as electrolyte layer, and the porous (200) film as an interlayer to a porous Pt anode, an open circuit voltage of 0.85 V was obtained in a micro machined fuel cell structure.

Energy Technology Data Exchange (ETDEWEB)

Today TBP and TBAs are the compounds which have the highest potential to replace the hydrides arsine and phosphine in the MOVPE process. The authors have demonstrated the entire material system Ga-In-As-P can be grown without any loss of quality using TBP and TBAs not only in one reactor, but in a complete family of reactors. These reactors range from small-scale single wafer R and D reactors to multiwafer Planetary Reactor systems. Both InP based and GaAs based materials could be grown with an excellent quality. Thus all growth processes for III-V devices--long and short wavelength lasers, LEDs, high speed transistors, etc.--can be switched to TBP and TBAs. This will drastically reduce safety hazards and lead to processes that have advantages both from the ecological and economical point of view.

British Library Electronic Table of Contents (United Kingdom)

Summary: Analysis of biological networks requires assessing the statistical significance of network-based predictions by using a realistic null model. However, the existing network null model, switch randomization, is unsuitable for metabolic networks, as it does not include physical constraints and generates unrealistic reactions. We present JMassBalance, a tool for mass-balanced randomization and analysis of metabolic networks. The tool allows efficient generation of large sets of randomized networks under the physical constraint of mass balance. In addition, various structural properties of the original and randomized networks can be calculated, facilitating the identification of the salient properties of metabolic networks with a biologically meaningful null model. Availability and Imp...

International Nuclear Information System (INIS)

Orbit correction is now routinely performed at the few-micron level in the Advanced Photon Source (APS) storage ring. Three diagnostics are presently in use to measure and control both AC and DC orbit motions: broad-band turn-by-turn rf beam position monitors (BPMs), narrow-band switched heterodyne receivers, and photoemission-style x-ray beam position monitors. Each type of diagnostic has its own set of systematic error effects that place limits on the ultimate pointing stability of x-ray beams supplied to users at the APS. Limiting sources of beam motion at present are magnet power supply noise, girder vibration, and thermal timescale vacuum chamber and girder motion. This paper will investigate the present limitations on orbit correction, and will delve into the upgrades necessary to achieve true sub-micron beam stability.

International Nuclear Information System (INIS)

The mass asymmetry of fragments from nuclear fission of heavy nuclei is reviewed. While mass asymmetry is a common and well-known phenomenon for low-energy fission of the lighter actinides, more recent experiments have demonstrated that, for the heaviest actinides, the mass distribution switches to a symmetric one. On the other hand, it has been discovered that, though for fissioning nuclei with mass numbers A< or #approx#225 the mass distribution is basically symmetric, an asymmetric component is clearly to be identified for nuclei down to the Pb-region. In the absence of a generally accepted dynamical theory of fission, the above experimental findings are discussed in terms of static energy considerations. Triggered from the outset by the structure of the potential energy surface at the saddlepoint, the energy balance at the scission point between the available energy (Q-value) of the reaction and the Coulomb and deformation energy of the nascent fragments is ...

International Nuclear Information System (INIS)

A new magnet power supply system for J-PARC 50GeV Synchrotron is proposed as solutions both in the power capacity and in the precision at the same time. The developed 10MW class magnet power supply consists of the advanced self-commutated current-source type converter (ACSC) using the new device IEGT rated at 4500V-2100A and the ''hybrid filter'' including the variable impedance filter with the equivalent 16 kHz switching. With 1/16 scale-model system using a prototype bending magnet, the experimental results showed the current ripple less than 1 x 10"-"6 and the tracking error less than #+-#0.5 x 10"-"4. (author)

British Library Electronic Table of Contents (United Kingdom)

A red basil cell line (T2b) rich in rosmarinic acid (RA) was selected for the stable production of anthocyanins (ACs) in the dark. Cell suspension cultures were subjected to mechanical stress through increased agitation (switch from 90 to 150rpm) to determine the relationship between AC and RA accumulation. Cell extracts were analyzed by HPLC and LC-MS, and the resulting data were processed with multivariate statistical analysis. MS and MS/MS spectra facilitated the putative annotation of several complex cyanidin-based ACs, which were esterified with coumaric acid and, in some cases, also with malonic acid. It was also possible to identify various RA-related molecules, some caffeic and coumaric acid derivatives and some flavanones. Mechanical stress increased the total AC and RA contents, ...

CERN Document Server

We extend a previous result [Phys. Rev. Lett. 105, 090403 (2010)] on Casimir repulsion between a plate with a hole and a cylinder centered above it to geometries in which the central object can no longer be treated as a point dipole. We show through numerical calculations that as the distance between the plate and central object decreases, there is an intermediate regime in which the repulsive force increases dramatically. Beyond this, the force rapidly switches over to attraction as the separation decreases further to zero, in line with the proximity force approximation. We demonstrate that this effect can be understood as a competition between an increased repulsion due to a larger polarizability of the central object interacting with increased fringing fields near the edge of the plate, and attractive forces due primarily to the nonzero thickness of the plate. In comparison with our previous work, we find that using the same plate geometry but replacing the ...

British Library Electronic Table of Contents (United Kingdom)

Assembly of icosahedral capsids of proper size and symmetry is not understood. Residue F170 in bacteriophage P22 coat protein is critical for conformational switching during assembly. Substitutions at this site cause assembly of tubes of hexamerically arranged coat protein. Intragenic suppressors of the ts phenotype of F170A and F170K coat protein mutants were isolated. Suppressors were repeatedly found in the coat protein telokin-like domain at position 285, which caused coat protein to assemble into petite procapsids and capsids. Petite capsid assembly strongly correlated to the side chain volume of the substituted amino acid. We hypothesize that larger side chains at position 285 torque the telokin-like domain, changing flexibility of the subunit and intercapsomer contacts. Thus, a sing...

International Nuclear Information System (INIS)

A high sensitivity, high bandwidth, two-color interferometer (1064 and 532 nm) has been tested on the Hawk pulsed power generator at the Naval Research Laboratory. The phase resolution is 10"-"5 waves with a rise time of 3 ns, a new capability for diagnosing plasmas, and neutrals in pulsed power experiments. The two-color feature is used to distinguish phase shifts from free (plasma) electrons and bound (neutral and ion) electrons. Simultaneous electron and neutral density measurements were demonstrated in a plasma opening switch (POS) experiment. The ability to measure small phase shifts with fast rise time were demonstrated in a plasma filled diode experiment. The high sensitivity and vibration isolation enable neutral gas distribution measurements from supersonic nozzles used in plasma radiation source experiments. Examples of these measurements and future applications are described. copyright 1997 American Institute of Physics.

Science.gov (United States)

... Accession Number : ADA350829. Title : Operational Characteristics of a Liquid Nitrogen Powered Automobile. Descriptive Note : Master's thesis. ...

Science.gov (United States)

... in the Vicinity of Terminal Areas," Ph. ... WORDS Operations Research Stochastic processes Mathematical ... theory Aut',matic control Queueing theory ...

Science.gov (United States)

... CYBERSPACE DOMAIN: A ... 4. TITLE AND SUBTITLE Cyberspace Domain: A Warfighting Substantiated Operational Environment Imperative 5a. ...

Energy Technology Data Exchange (ETDEWEB)

Most environmental policies provide for special emergency measures to be taken during phases of high pollution, such as smog alarm regulations. These measures serve several purposes and can have various impacts. First of all, they act as a warning to those parts of the population immediately threatened by health hazards (Warnfunktion). They may be directed at short-term pollution reduction via pollution abatement measures proscribed during smog alarm situations (unmittelbare Steuerungsfunktion). In addition, the announcement of emergency measures may signal that pollution levels in general have been too high, indicating that the environmental policies normally pursued do not sufficiently or effectively protect human beings and the environment from harm (Signalfunktion). Emergency measures often contain special regulations obliging industrial polluters to switch to costly, less polluting production processes, or to stop production altogether. This may act as an ...

Energy Technology Data Exchange (ETDEWEB)

A semi-automatic system which considers operation in a face by monitoring technological parameters of an extraction vehicle and a longwall conveyor is examined. The system records in tabular form the location, progress made, operating and down time of an extraction vehicle and operating and down time of the conveyor. A description of the operating principle system and systems for arrangement of the remote sensing and central recording device are presented. (Note: extraction vehicle not identified: LTN)

Energy Technology Data Exchange (ETDEWEB)

A procedure was developed to monitor boundaries within which secondary mining operations can be applied. Principal techniques include instrument and operative-remote observations of earth shifts and aerial photography of displacements on the surface of the trough.

Science.gov (United States)

Military working dogs are rapidly becoming integral to military operations. While they bring many valuable capabilities to the battlefield, it is important that Special Operations leaders consider canine team capabilities and requirements when planning mi...

Science.gov (United States)

The 17-metre DOE/Sandia VAWT began operation in March 1977. Since that time the turbine has been operated strictly by manual control for the purpose of data acquisition and performance analysis; this procedure has limited the VAWT operation time and power...

Science.gov (United States)

...2009-07-01 2009-07-01 false Loading and haulage equipment; operation. 77.1607 Section 77.1607...Loading and Haulage § 77.1607 Loading and haulage equipment; operation. (a) Vehicles shall follow...

Science.gov (United States)

... Third World Arms Proliferation and Forced Entry Operations: Circumstances Demanding the Creation of a Standing Joint Task Force Headquarters. ...

Science.gov (United States)

... east. The two most important offensives, Operation EPSOM (25 June to 1 July 1944) and Operation GOODWOOD (18 to ...

UK PubMed Central (United Kingdom)

Securing the co-operation of persons supplying information required for medical statistics is essentially a problem in human relations, and an understanding of the motivations, attitudes, and behaviour...Full Text Available

Energy Technology Data Exchange (ETDEWEB)

This document details monthly activities at the Savannah River Laboratory. Topics addressed are reactor operation; tritium facilities and production; separation operations; environmental concerns; and waste management. (FI)

Science.gov (United States)

Task, Psychomotor Vigilance Test (PVT) Transition to Operations ... Related Tasks (36). Task, Psychomotor Vigilance Test (PVT) on ISS. Common Item(s) ...

International Nuclear Information System (INIS)

Data on French nuclear electricity generation sites, nuclear power plant operations personnel, operation simulators, nuclear training centers and training statistics are presented.

Science.gov (United States)

... less humans have to do to operate a robot. ... Robots can help human operators with the increase ... important mission outlined by the UUV master plan. ...

International Nuclear Information System (INIS)

The document presented defines the plan to be used to coordinate the preparation, review, approval, and issuance of the operating procedure documents required to ensure safe and efficient operation of FFTF.

Science.gov (United States)

The rate of battery use is sometimes even higher in military operations. During Operation Iraqi Freedom, the Marines used more than 3000 single-use ...

Science.gov (United States)

...QUALIFICATION AND CERTIFICATION OF LOCOMOTIVE ENGINEERS Implementation of the Certification...operations and certifies locomotive engineers from a different railroad...designated supervisor of locomotive engineers or a certified train...

Energy Technology Data Exchange (ETDEWEB)

Recent studies indicate that [Fe]-hydrogenases and H{sub 2} metabolism are widely distributed among green algae. The enzymes are simple structured and catalyze H{sub 2} evolution with similar rates than the more complex [Fe]-hydrogenases from bacteria. Different green algal species developed diverse strategies to survive under sulfur deprivation. Chlamydomonas reinhardtii evolves large quantities of hydrogen gas in the absence of sulfur. In a sealed culture of C. reinhardtii, the photosynthetic O{sub 2} evolution rate drops below the rate of respiratory O{sub 2} consumption due to a reversible inhibition of photosystem II, thus leading to an intracellular anaerobiosis. The algal cells survive under these anaerobic conditions by switching their metabolism to a kind of photo-fermentation. Although possessing a functional [Fe]-hydrogenase gene, the cells of Scenedesmus obliquus produce no significant amounts of H{sub 2} under S-depleted conditions. Biochemical ...

CERN Document Server

We explore a planar GaAs/AlAs photonic microcavity using pump-probe spectroscopy. Free carriers are excited in the GaAs with short pump pulses. The time-resolved reflectivity is spectrally resolved short probe pulses. We show experimentally that the cavity resonance and its width depend on the dynamic refractive index of both the lambda-slab and the lambda/4 GaAs mirrors. We clearly observe a double exponential relaxation of both the the cavity resonance and its width, which is due to the different recombination timescales in the lambda-slab and the mirrors. In particular, the relaxation time due to the GaAs mirrors approaches the photon storage time of the cavity, a regime for which nonlinear effects have been predicted. The strongly non-single exponential behavior of the resonance and the width is in excellent agreement to a transfer-matrix model taking into account two recombination times. The change in width leads to a change in reflectivity modulation depth. The model predicts an ...

International Nuclear Information System (INIS)

We present 14 years of contemporaneous photometric and spectroscopic observations of 28 solar analog stars, taken with the Tennessee State University Automatic Photometric Telescopes at Fairborn Observatory and the Solar-Stellar Spectrograph at Lowell Observatory. These are the best observed and most nearly Sun-like of the targets in our magnitude-limited (V #<=# 7.5) sample. The correlations between luminosity and activity reveal the expected inverse activity-brightness correlations for active stars. Strong direct correlations between activity and brightness are not prevalent for the less active solar age stars, but are precision limited. The Sun does not appear to have unusually low photometric variability when compared with the most Sun-like inactive solar analogs. We present evidence that the activity index R'_H_K is not a good discriminant of Maunder Minimum candidate stars. On the basis of a star that appears to have transitioned from a low-variability state to a cycling ...

Energy Technology Data Exchange (ETDEWEB)

Abstract: We report for the selective-area chemical synthesis of semiconductor single-crystal organic nanowires of silver-tetracyanoquinodimethane (Ag-TCNQ). Straight and smooth Ag-TCNQ nanowires can be produced and patterned on micrometer and nanometer scale on silicon substrates covered with a thin layer of Ag film through the reaction of TCNQ and Ag in a simple gas-solid chemical reaction process. Ag-TCNQ nanowires are characterized by UV-vis, IR and Raman spectroscopy, respectively. The Ag-TCNQ nanowires grows preferentially along the [100] direction of strong - stacking of Ag-TCNQ molecules. Nanodevices based on these nanowires are fabricated using focus ion beam (FIB) technique. Electrical properties are characterized and I-V hysteresis is observed, which shows memory effect with electrical switching of three orders on-off ratio. These nanowires could be potential for use in optical storage, ultrahigh-density nanoscale memory and logic devices.

CERN Document Server

We study an exactly solvable model where an uniformly accelerated detector is linearly coupled to a massless scalar field initially in the Minkowski vacuum. Using the exact correlation functions we show that as soon as the coupling is switched on one can see information flowing from the detector to the field and propagating with the radiation into null infinity. By expressing the reduced density matrix of the detector in terms of the two-point functions, we calculate the purity function in the detector and study the evolution of quantum entanglement between the detector and the field. Only in the ultraweak coupling regime could some degree of recoherence in the detector appear at late times, but never in full restoration, as an earlier work seems to suggest. We explicitly show that under the most general conditions the detector never recovers its quantum coherence and the entanglement between the detector and the field remains large at late times. To the extent ...

Energy Technology Data Exchange (ETDEWEB)

After confirming that residual chlorine in tap water, which is regarded as one of the major cause of pitting corrosion, can be decomposed/removed by the irradiation of UV light, effect of dechlorinated water obtained based on this principle on the prevention of pitting corrosion, generation and growth, of the copper tubing was investigated by a corrosion test simulated the actual system in high buildings. (1) Low pressure type mercury lamp easily decompose/remove the residual chlorine. (2) If the dechlorinated water is supplied from the initial stage of copper tube usage, potential of the copper tube remains at the level of 100 mV/SCE and the generation of pitting corrosion is not observed. (3) Even when pitting corrosion is already found, switching to dechlorinated water in the midway reduces the potential of the copper tube down to 50 - 70 mV level, at the same time completely restricting the growth of the pitting corrosion. (15 figs, 9 refs)

Energy Technology Data Exchange (ETDEWEB)

A cooling system was developed which could be used even in such areas where the maximum and minimum temperatures of a day might differ widely. The system features in that a latent heat storage unit is connected to the natural circulation cooling unit consisting of 2 heat exchangers where condensed gas (refrigerant) which performs gas-liquid change has been sealed, enabling to cool objects night and day without the requirement for any power source. Electronic equipment was installed in an insulated shelter. Lauric acid and refrigerant R-22 were used as the latent heat storage medium and the heat transport medium respectively. Natural convection heat transfer performance of the outside surfaces of the condenser and the evaporator and the transient behavior of the system during the melting and solidification periods of the latent heat storage medium were tested. As a result of a 48 hour simulation experiment with load conditions set basing on the result of load computation, smooth ...

Energy Technology Data Exchange (ETDEWEB)

The corrosion behavior of Alloy 800 and Type 316 stainless steel in molten NaNO/sub 3/-KNO/sub 3/ was studied at temperatures from 605/degree/C to 630/degree/C. Corrosion behavior was significantly different from that previously reported in nitrate melts at temperatures up to 600/degree/C and involved a combination of oxidation, internal nitridation and sodium metallate formation. Corrosion kinetics, determined metallographically, switched from a parabolic to a linear rate equation as temperature increased. Corrosion was uniform and resulted in metal losses on the order of 100 micronsyear at 630/degree/C. Among the alloying elements, chromium was depleted from the alloy as the result of a basic fluxing process. The kinetic equations describing chromium depletion also changed from parabolic to linear with increasing temperature. The effect of the equilibrium chemistry of the melt on the corrosion behavior of the alloys is analyzed and possible corrosion mechanisms ...

Science.gov (United States)

Understanding the influence of interfacial structures on the nanoarchitecture mechanical properties is of particular importance for its mechanical applications. Due to a small size of constituting nanostructural units and a consequently high volume ratio of such interfacial regions, this question becomes crucial for the overall mechanical performance. Boron nitride bamboo-like nanotubes, called hereafter boron nitride nanobamboos (BNNBs), are composed of short BN nanotubular segments with specific interfaces at the bamboo-shaped joints. In this work, the mechanical properties of such structures are investigated by using direct in situ transmission electron microscopy tensile tests and molecular dynamics simulations. The mechanical properties and deformation behaviors are correlated with the interfacial structure under atomic resolution, and a geometry strengthening effect is clearly demonstrated. Due to the interlocked joint interfacial structures and compressive interfacial stresses, ...

Energy Technology Data Exchange (ETDEWEB)

This paper was presented at the opening plenary session. As the end of the century approaches, environmental protection is one of the most significant global issues which will shape our energy path and economic development pattern. In face of environmental challenges, we will have to take into account environmental factors in the economic development process itself. This requires the pursuit of sustainable economic development, a process which may involve strengthened energy conservation, improved efficiency and switching to less carbon intensive energy sources. Energy inefficiency, technological scarcity and financial vulnerability in developing countries may best be resolved by changing their economic and market structures to facilitate relevant investments. However, effective reform of the energy industry in developing economies and economies in transition will also require international cooperation in terms of transfer of technology, capital, know-how and ...

Energy Technology Data Exchange (ETDEWEB)

Fermilab's Advanced Computer Program (ACP) has been developing highly cost effective, yet practical, parallel computers for high energy physics since 1984. The ACP's latest developments are proceeding in two directions. A Second Generation ACP Multiprocessor System for experiments will include $3500 RISC processors each with performance over 15 VAX MIPS. To support such high performance, the new system allows parallel I/O, parallel interprocess communication, and parallel host processes. The ACP Multi-Array Processor, has been developed for theoretical physics. Each $4000 node is a FORTRAN or C programmable pipelined 20 MFlops (peak), 10 MByte single board computer. These are plugged into a 16 port crossbar switch crate which handles both inter and intra crate communication. The crates are connected in a hypercube. Site oriented applications like lattice gauge theory are supported by system software called CANOPY, which makes the hardware ...

Energy Technology Data Exchange (ETDEWEB)

A non-synthetic polymer material, polyterpenol, was fabricated using a dry polymerization process namely RF plasma polymerization from an environmentally friendly monomer and its surface, optical and electrical properties investigated. Polyterpenol films were found to be transparent over the visible wavelength range, with a smooth surface with an average roughness of less than 0.4 nm and hardness of 0.4 GPa. The dielectric constant of 3.4 for polyterpenol was higher than that of the conventional polymer materials used in the organic electronic devices. The non-synthetic polymer material was then implemented as a surface modification of the gate insulator in field effect transistor (OFET) and the properties of the device were examined. In comparison to the similar device without the polymer insulating layer, the polyterpenol based OFET device showed significant improvements. The addition of the polyterpenol interlayer in the OFET shifted the threshold voltage significantly; + 20 V to -3 ...

International Nuclear Information System (INIS)

Single crystals of semi-organic L-histidine hydrobromide have been grown by slow evaporation technique from a mixture of L-histidine and hydrobromic acid in aqueous solution at ambient temperature. From high-resolution X-ray diffraction analysis, the crystalline perfection of the grown crystal has been studied. Single crystal X-ray diffraction analyses, Nuclear Magnetic Resonance spectral analysis, Thermo-Gravimetry (TG), Differential Thermal Analysis (DTA) and hardness test have been employed to characterize the as-grown crystals. The UV cutoff wavelength of the grown crystal is below 300 nm and has a wide transparency window, which is suitable for second harmonic generation of laser in the blue region. Nonlinear optical characteristics have been studied using Q switched Nd:YAG laser (#lambda#=1064 nm). The second harmonic generation conversion efficiency of the grown crystals confirms their suitability for frequency conversion applications.

International Nuclear Information System (INIS)

The macrotemporal structure of the Super-ACO Storage ring free-electron laser (FEL) can be either continuous, pulsed, or chaotic, and can present some rapid fluctuations. The temporal evolution of a storage ring FEL involves both the longitudinal motion of the positron beam (especially the synchrotron oscillations) and the FEL dynamics, as in a coupled system. Studies on the dynamics of the positron beam are performed here, in the goal to have a stable source for FEL applications, and to determine the conditions for a stable Q-switching experiment. The employed method is to study the influence of a controlled change of the radio frequency (RF) (modulation or frequency jump) on the beam. A simple theoretical model taking into account the perturbed RF system is presented to help the understanding of the experimental data. The different methods of measurement are described. Then, the results are given for several experimental conditions and the influence of different ...

Science.gov (United States)

In the current wind turbine generation system, there are substantial problems such as the maximum power of the wind turbine cannot be obtained under the fluctuating wind speed, high in cost and low in annual net electricity production (due to mismatch between a generator and a wind turbine). A new wind turbine generator optimized for the wind turbine output is presented in order to solve such problems. This wind turbine generator consists of a permanent magnet generator, a reactor and a rectifier, and uses neither a control circuit which requires standby electricity nor a PWM converter having a switching element. By selecting most appropriate combination of the permanent magnet generator having multiple windings and the reactor connected in series with each winding, the maximum output of the wind turbine can be obtained without using a control circuit. The new wind turbine generator was directly coupled with the straight wing non-articulated vertical axis wind ...

KoreaScience (Korea)

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Energy Technology Data Exchange (ETDEWEB)

Here the authors try to dissolve some commonly held misconceptions about the operation of eddy current probes used for inspecting heat exchanger tubes. With the help of computer model results, the authors demonstrate that, for optimized operation, absolute/differential probes should be operated with coil current flowing in phase with another. This month's feature should be of interest to researchers as well as for NDT field personnel.

International Nuclear Information System (INIS)

On the basis of legally provided area dose measurements and time records of fluoroscopic examinations during the operation, radiation doses to medical personnel and patients are evaluated. Adequate radiation protection measures and a careful behaviour in the operating room keep the radiation exposure to the personnel below the maximum permissible exposure. Taking into account the continuous personnel radiation monitoring and medical supervision, radiation hazards in the operating room can be considered low.

International Nuclear Information System (INIS)

... bwr type reactors closures fluidic control devices operation performance pwr

KoreaScience (Korea)

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KoreaScience (Korea)

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Medline Plus

... their entire colon removed in an operation called colostomy. A colostomy, which reroutes the intestines to an opening in ...

Energy Technology Data Exchange (ETDEWEB)

No abstract prepared.

Energy Technology Data Exchange (ETDEWEB)

The costs of establishing a computer-based training program for FFTF reactor operators are analyzed.

KoreaScience (Korea)

Full Text Available

Science.gov (United States)

... numbers of marine mammals during operation of an offshore liquefied natural gas (LNG) facility in the Massachusetts Bay for ... ...

Science.gov (United States)

... harassment, incidental to construction and operation of an offshore liquefied natural gas (LNG) facility. Under the Marine Mammal Protection ... ...

Energy Technology Data Exchange (ETDEWEB)

Collectively, the organizations participating in the Site Operator Program have over forty years of EV experience and have operated electric vehicles (EVs) for over 600,000 miles, providing the most extensive EV operating and knowledge base in the country. The Site Operator Program is intended to provide financial and technical support and organizational resources to organizations active in the advancement of electric vehicles. Support is provided for the demonstration of vehicles and the test and evaluation of vehicles, components, and batteries. Support is also provided for the management and support of the program for the participating organizations. The Program provides a forum for participants to exchange information among the group, as well as with vehicle and equipment manufacturers and suppliers, and the public. A central data base at the Idaho National Engineering Laboratory provides a ...

Energy Technology Data Exchange (ETDEWEB)

This paper presents a new approach for solving multistage decision problems in power system operation by using a new fuzzy dynamic programming technique. To investigate its validity, the hydrothermal scheduling problem is used as an example problem. Within this problem, uncertainty elements exist such as load demand and natural hydraulic inflows to reservoirs exist which can be expressed by fuzzy numbers. Two new fuzzy decision making techniques for selecting the optimal operating states at each stage are introduced. Further, the hydrothermal scheduling solution obtained had an operating band defined by upper and lower bounds. To further enhance the information that this operating band provides, a midpoint operation technique that applies both forward and backward fuzzy DP is also introduced. This allows the system operator to consider current ...

Science.gov (United States)

This Waste Management Plan functions as a management and planning tool for managing waste streams generated as a result of operations at the Idaho CERCLA Disposal Facility (ICDF) Complex. The waste management activities described in this plan support the selected remedy presented in the Waste Area Group 3, Operable Unit 3-13 Final Record of Decision for the operation of the Idaho CERCLA Disposal Facility Complex. This plan identifies the types of waste that are anticipated during operations at the Idaho CERCLA Disposal Facility Complex. In addition, this plan presents management strategies and disposition for these anticipated waste streams.

Energy Technology Data Exchange (ETDEWEB)

This report contains the operation procedures in extreme situations and lessons learned from blackouts, based on a mandate given by the Operations Committee. Nordic TSOs have had common rules and principles for system operation i.e. System Operation Agreement since the late 1990s. The rules have been revised according to the system security and market changes and needs. The collaboration between system operators is regular and fruitful. The knowledge and capability to manage extreme situations of the Nordic power system has continuously increased and the recent blackouts did not show major deficiencies in operation practices. Regardless of the existing good collaboration it is important to continue development in the future in order to ensure high system security. Important development areas are security of reserve supervision and coordination of calculation ...

Energy Technology Data Exchange (ETDEWEB)

Performance of electric vehicles (EVs) is being studied in an ongoing Site Operator Program, as part of the Electric and Hybrid Vehicle Program supported by the U.S. Department of Energy (DOE). More than 200 EVs are being operated by Site Operators in various geographical and climatic regions of the United States. Cold-weather operation of EVs is of particular interest. As expected, low temperatures affect a battery`s ability to accept a charge, which decreases EV range and increases operating costs. Battery types other than lead-acid are being evaluated such as nickel-iron, gelled electrolyte lead-acid, nickel-cadmium, and sodium-sulfur. Also, improved methods of collecting EV performance data are being implemented, thermal management systems are being tested, and a prototype ultracapacitor is being tested as a possible alternative to conventional batteries.

Energy Technology Data Exchange (ETDEWEB)

This report presents the results of a study on Operation and Maintenance (O M) practices in hydroelectric pumped storage plants. The objective of this project, which was sponsored by EPRI, is to record the practical knowledge on the O M of a number of the domestic and foreign pumped storage plants which has been accumulated by their operating staff. Civil, geotechnical, mechanical and electrical aspects of O M of the thirty-five plants visited are discussed, and some general conclusions, as warranted by the commonality of the problems, are drawn. These conclusions may be useful to the planners and designers of future pumped storage projects. In general, due to their layout, diversity and different modes of operation, the plants have few common problems which, in most cases, are limited to the mechanical and electrical aspects of the plants' operation. The data on plants' ...

Energy Technology Data Exchange (ETDEWEB)

This invention pertains to a light weight underground pipe or cable installing device adapted for use in a narrow and deep operating trench. More particularly this underground pipe installing device employs a pair of laterally movable gates positioned adjacent the bottom of the operating trench where the earth is more solid to securely clamp the device in the operating trench to enable it to withstand the forces exerted as the actuating rod is forced through the earth from the so-called operating trench to the target trench. To accommodate the laterally movable gates positioned adjacent the bottom of the narrow pipe installing device, a pair of top operated double-acting rod clamping jaws, operated by a hydraulic cylinder positioned above the actuating rod are employed.

UK PubMed Central (United Kingdom)

Synthetic oligoribonucleotides have been used to probe the interaction of MS2 coat protein with the translational operator of the MS2 replicase gene. We have investigated the possible formation of a...Full Text Available

UK PubMed Central (United Kingdom)

Background:The US military is currently involved in large, lengthy, and complex combat operations around the world. Effective military operations require optimal health of deployed...Full Text Available