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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.

UK PubMed Central (United Kingdom)

OBJECTIVE: To evaluate the effectiveness of a program to improve hypertension control practices in primary care. DESIGN: Retrospective quasi-experimental study. SETTING: Three hospital-based family...Full Text Available

UK PubMed Central (United Kingdom)

Reliable characterization of locomotor dynamics of human walking is vital to understanding the neuromuscular control of human locomotion and disease diagnosis. However, the inherent oscillation and...Full Text Available

Science.gov (United States)

A dc-to-dc converter has been designed which employs the synchronizing phenomenon in the transistor core multivibrator. In the proposed circuit, the voltage feedback is applied from the control transistor and the current feedback is applied from the main transistor. The operation of the converter is analyzed by the averaging method of the state space technique. The converter features small switching loss and is suitable for high frequency operation. An efficiency of more than 95% is obtained for 5 V, 3 A output at a switching frequency of 200 kHz.

Energy Technology Data Exchange (ETDEWEB)

This paper presents a technique for speed control three-phase induction motor using the pulse width modulation (PWM), in open loop while maintaining the tension for constant frequency. The technique is adapted from a thesis entitled 'Control of the three-phase induction motor, using discrete PWM generation, optimized and synchronized', where studies are presented aimed at their application in home appliances, to eliminate mechanical parts, replaced by low cost electronic control, thus having a significant reduction in power consumption. Initially the experiment was done with the Intel 80C31 micro controller. In this paper, the PWM modulation is implemented using a PIC micro controller, and the speed control kept a low profile, based on tables, synchronized with transitions and reduced generation of ...

Energy Technology Data Exchange (ETDEWEB)

Most pumped-storage plants have the capability to operate as synchronous condensers. As such, they can be brought on line very quickly to support system load requirements. However, one of the effects of making a rapid transition from synchronous condenser operation to turbine/governor operation is an initial reverse power flow into the machine. This reverse power flow can be very undesirable at a time when the system is calling for load support. On weak or isolated systems, this reverse power flow can lead to objectionable voltage and frequency dips in the system. With the proper utilization of a static frequency converter (SFC) and its associated controls and auxiliary switchgear systems, the reverse power flow resulting from a transition from synchronous condenser operation can be eliminated. This paper will describe the method by which an SFC system can be used to make this rapid load response in ...

Energy Technology Data Exchange (ETDEWEB)

In this paper, power system stabilizer design for multi-machine power systems is translated into an equivalent problem of decentralized controller design for Multi-Output Multi-Input (MIMO) control systems. Subject to a condition based on the structured singular values, each stabilizer can be designed independently. Within this general framework, the conventional stabilizer design methodology based on the concept of synchronous and damping torques is used to decide the design details of each stabilizer. The suggested design method is applied to a model of a practical 10 machine power system. (author)

Energy Technology Data Exchange (ETDEWEB)

A robust adaptive Power System Stabilizer algorithm using a Generalized Multivariable Pole Shifting (GMPS) technique is presented in this paper. The algorithm handles systems with equal or unequal numbers of inputs and outputs, therefore both shaft speed as well as the generator power are used to derive the stabilizing control. The technique also provides a simple scheme of on-line self-searching pole shifting factor to meet the excitation control limits. The application of the proposed stabilizer to a simulated generator excitation control under a wide range of operating and disturbance conditions demonstrates that the new control strategy is superior to conventional Power System Stabilizer (PSS) and the widely accepted Minimum Variance Self-Tuning Controller (MVSTC).

International Nuclear Information System (INIS)

Recent results of experimental and theoretical investigations, carried out in the Institute of plasma Physics of the NSC KIPT, are presented in the report. The main problems of discussion are as follows: plasma confinement and heating in stellarators and electromagnetic traps; powerful quasi-steady-state plasma accelerators (QSPA); experiments relevant for ITER; fusion Plasma theory; methods of high temperature plasma diagnostics; plasma technology. The main prospects on the IPP investigators are discussed also.

Energy Technology Data Exchange (ETDEWEB)

Power system stabilizers (PSSs) are used to enhance damping of power system oscillations through excitation control of synchronous generator. The objective of the PSS is to generate a stabilizing signal, which produces a damping torque component on the generator shaft. Conventional PSSs are designed with the phase compensation technique in the frequency domain and include the lead-lag blocks whose parameters are determined according to a linearized power system model. The performance of conventional PSSs (CPSSs) depends upon the generator operating point and the system parameters, but a reasonable level of robustness can be achieved depending on the tuning method. This paper presents a new three-dimensional PSS (3D PSS), which uses rotor speed deviation, rotor acceleration and load angle deviation as input signals. The 3D PSS attempts to return the generator to the state-space origin, based on the generator's trajectory in state-space ...

Science.gov (United States)

Advances in the development of several electrooptic shutter devices utilizing the quadratic electrooptic effect of lead lanthanum zirconate titanate (PLZT) ceramic wafers are described. Aperture sizes utilized in these PLZT devices ranged from 25 ..mu..m to 0.25 m. Practical applications of the shutters discussed in this paper include eye protection in military and industrial applications, a goggle-type device with dual synchronously operated PLZT shutters for use in a stereoscopic three-dimensional TV display, an electrically controlled variable density filter for use with vidicon tubes, a large-aperture photographic shutter for image motion compensation cameras, and a page composer for use in a holographic memory system.

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 ...

Energy Technology Data Exchange (ETDEWEB)

A method and apparatus for determining the condition of tissue or otherwise making chemical identifications includes exposing the sample to a light source, and using a synchronous luminescence system to produce a spectrum that can be analyzed for tissue condition.

Energy Technology Data Exchange (ETDEWEB)

Research highlights: {yields} Mathematical model represents a power system which consists of synchronous machine connected to infinite bus through transmission line. {yields} Power system stabilizer was designed based on optimal pole shifting controller. {yields} The system performances was tested through load disturbances at different operating conditions. {yields} The system performance with the proposed optimal pole shifting controller is compared with the conventional pole placement controller. {yields} The digital simulation results indicated that the proposed controller has a superior performance. -- Abstract: Power system stabilizer based on optimal pole shifting is proposed. An approach for shifting the real parts of the open-loop poles to any desired positions while preserving the imaginary parts is presented. In each step of this approach, it is required to solve a ...

Energy Technology Data Exchange (ETDEWEB)

The Idaho Explosives Detection System was developed at the Idaho National Laboratory (INL) to respond to threats imposed by delivery trucks potentially carrying explosives into military bases. A full-scale prototype system has been built and is currently undergoing testing. The system consists of two racks, one on each side of a subject vehicle. Each rack includes a neutron generator and an array of NaI detectors. The two neutron generators are pulsed and synchronized. A laptop computer controls the entire system. The control software is easily operable by minimally trained staff. The system was developed to detect explosives in a medium size truck within a 5-min measurement time. System performance was successfully demonstrated with explosives at the INL in June 2004 and at Andrews Air Force Base in July 2004.

International Nuclear Information System (INIS)

On June 19, 1998, after the first annual outage, Wolsung Unit 2 was shutdown at a controlled rate due to the continuous instability of Liquid Zone Control level. Investigation revealed that the Liquid Zone Control level instability was caused by water condensed inside the helium lines, generated from the moistened helium flow, especially, inside the helium balance header feed and bleed valve lines. It was found that improper installation of the diaphragm type isolation valves and the drain valve tap could easily contain the water inside the lines and be destined to form water traps causing the balance header pressure oscillation. After the lines were dried, Liquid Zone Control level instability was almost vanished, and approached the allowable equilibrium state. As the reactor power was increased, however, the zone level instability increased again. In order to compensate for the excessive, the Bulk ...

International Nuclear Information System (INIS)

For the purpose of optimizing the process of co-implantation of MeV Si ions to reduce boron transient enhanced diffusion and boron-enhanced diffusion in Si, multiple MeV implantations and annealing at different temperatures have been performed. A slight improvement on the suppression of B diffusion is observed by adding a low temperature annealing step after the MeV implantation. No differences in B diffusion are observed when the Si doses are increased from 1 x 10"1"5 to 1 x 10"1"6 cm"-"2. This dose independent behavior is speculated to be a quasi-steady state of vacancy cluster evaporation.

British Library Electronic Table of Contents (United Kingdom)

Energy saving technologies in the railway vehicle traction field can be mainly categorized into two domains: reducing loss and increasing the regenerative energy. Energy saving technologies for the traction equipment by the use of power converters with less loss and high-efficiency permanent magnet synchronous motors are introduced. The regenerative brake related technologies are also presented as another measure to save the energy, including the improvement of the regenerative brake control and application of energy storage devices. It is concluded that the benefit of the energy saving technology is not only the energy saving itself but also downsizing traction equipments and reducing the maintenance work in the electrical railway system. Copyright Copyright 2010 Institute of Electrical E...

International Nuclear Information System (INIS)

The author discusses the formulation and application of the theory of quasi-catastrophes for the behaviour and properties of tachyons. This approach assists in the interpretation of experiments where tachyons may be involved. (W.D.L.).

Energy Technology Data Exchange (ETDEWEB)

A highly reliable control rod drive mechanism (CRDM) installed inside the reactor vessel has developed for use of an advanced marine reactor. This CRDM contributes to compactness and simplicity of the reactor system, and it can eliminate the possibility of a rod ejection accident. The CRDM works in the high temperature and high pressure water - 310degC and 12 MPa, the same atmosphere as the primary loop. Driving force is produced by a synchronous motor with the rotor of a permanent magnet, which has been developed. An innovative latch mechanism using separable ball nuts can latch driving shaft connecting the control rod and de-latch it for scram. The rod position detector using a magnetostrictive wire type sensor on the principle of Wiedeman effect has been developed, accuracy of which is verified to have a detecting error within 1.2 mm. Ball bearings for thrust and radial supports in rotation have been developed to be ...

Science.gov (United States)

Folder Display Clocks Folder TWSTT Folder Loran-C Folder Telephone Time Folder NTP Info Web-Based Time Synchronization Web time displays from the USNO Master Clock, Washington, DC...

UK PubMed Central (United Kingdom)

Several theories have proposed a functional role for synchronous neuronal firing in generating the neural code of a sensory perception. Synchronous neural activity develops during a critical...Full Text Available

Science.gov (United States)

... to integrate and synchronize SC efforts and capabilities, as noted in the SC Roadmap, the joint community needs to publish SC policy and expand ...

Energy Technology Data Exchange (ETDEWEB)

This work presents the development of a streak camera 'jitter free' sweep unit synchronized on a femtosecond laser. This application of high voltage photoconductive switches ('High voltage Auston switch') yields subpicosecond resolution for accumulated images on streak camera on a few hundreds micro joule femtosecond laser. Two others applications of these photoconductive switches are studied: - ultrafast optical commutation by a Pockels cell directly driven by a photoconductive switch (rising edge < 100 ps and jitter < 2 ps), - laser pulse energy self-stabilization experimentally proving that driving a Pockels cell by a photoconductive switch can increase the stability of the laser pulse energy from 7 % to 0.7 % rms. Additionally, the application of the acoustic-optical programmable dispersive filter (Dazzler) to the self referenced spectral phase measurement is presented. As these measurements require a linear ...

CERN Document Server

A transformation monoid on a set Omega is called synchronizing if it contains an element of rank 1 (that is, mapping the whole of Omega to a single point). In this paper, I tackle the question: given n and k, what is the probability that the submonoid of the full transformation monoid T_n generated by k random transformations is synchronizing? This question is analogous to Dixon's Theorem that two random permutations generate the symmetric or alternating group with high probability. Following the technique of Dixon's theorem, we need to analyse the maximal non-synchronizing submonoids of T_n. I develop a very close connection between transformation monoids and graphs, from which we obtain a description of non-synchronizing monoids as endomorphism monoids of graphs satisfying some very strong conditions. However, counting such graphs, and dealing with the intersections of their endomorphism monoids, ...

UK PubMed Central (United Kingdom)

This paper evaluates the Post-Hospital Support Program for the frail elderly and their caregivers using a quasi-experimental design. The program goals were to reduce stress in the caregivers, improve...Full Text Available

Energy Technology Data Exchange (ETDEWEB)

A design of the modular coil system for CHS-qa has been made for the plasma configuration '2b32' with the aspect ratio 3.2. The magnetic field strength and the major radius are 1.5 T and 1.5 m, respectively. The normal component of magnetic field produced by the modular coils is minimized on the plasma boundary to obtain the optimum coil design. We put engineering constraint on the distance between adjacent modular coils and the radius of coil curvature. The dependence of the residual normal component of the field on these conditions is examined, and the realistic values for them are selected. Additional coils to control various properties of the magnetic field configuration (the rotational transform, the magnetic well depth, etc.) have been designed and a flexibility of the magnetic field configuration is realized. For the case that the rotational transform crosses the low-order rational value resulting in magnetic islands, the residues of ...

International Nuclear Information System (INIS)

Combination of radiotherapy and chemotherapy (CRC) is actually one important way of research in oncology. Theoretical advantages are: (1) Spatial cooperation; (2) Additivity, which is only obtained if the toxicity of each modality are different; (3) Supra-additivity, which needs a rigorous in vitro definition; the only way to prove it is to make an isobologram analysis. This model has however, some limitations: qualitative variable could not be used, results could be different, depending on the cell line and isoeffect chosen...In fact, a supra-additivity was only demonstrated for cis platinum and etoposide. Interactions mechanisms were: (1) at the molecular level, creation of new lesions or inhibition of radiation lesions repair; (2) At the cellular level, either cytokinetic cooperation with S-phase dependent drugs, or synchronization for the drugs which blocked the cells in M-phase; (3) At the tissular level, reoxygenation, cycle redistribution. In clinical ...

UK PubMed Central (United Kingdom)

Even when a healthy individual is studied, his/her erythrocytes in capillaries continually change their shape in a synchronized erratic fashion. In this work, the problem of characterizing the cell...Full Text Available

British Library Electronic Table of Contents (United Kingdom)

Communicating and collaborating online are becoming common requirements in education. The specialized notations and symbols necessary for some content areas where mathematical expressions are part of the conversation require that users select appropriate communication tools. The purpose of this article is to describe tools that can be used for online, asynchronous or synchronous communication involving mathematical expressions.

Energy Technology Data Exchange (ETDEWEB)

Software has been developed for the calculation of the thermodynamic cycle and the entropy changes in a turbocharged, direct injection, diesel engine based upon the measured cylinder pressure and a shaft encoder output. Assumptions of homogeneous mixture and equilibrium thermodynamic properties are made for the products of combustion and temporal variation in the fluid thermodynamic state is followed in a quasi-steady manner through a series of adjacent equilibrium states, each separated by finite intervals of one degree crank angle (1degCA). The thermodynamic properties are calculated by either of two equivalent formulations -- equilibrium constant or minimisation of Gibbs free energy, and are expressed in algebraic equations of the partial derivative of internal energy and gas constant with respect to temperature, pressure and equivalence ratio. The effect of the engine operating conditions on the thermodynamic cycle is studied, Results show that the dynamic fuel ...

International Nuclear Information System (INIS)

Both horizontally and vertically oriented rotating chambers with granular material held on the inner surface by centrifugal action are examined. Modifications to the condition for controlled quasi-static flow on an incline plane, phi/sub w/ < #alpha# < phi/sub r/, where phi/sub w/ is the wall friction angle, #alpha# is the angle of inclination of the plane, and phi/sub r/ is the drained angle of repose of the material are examined for the case of horizontal and vertical surfaces of revolution. Allowed included half angles for horizontally oriented chambers are likely to be in the range of 30"0 +- 10"0 for ceramic particles and metal surfaces. For vertical orientations the maximum half-angle of the top cone is slightly less than the wall friction angle phi/sub w/ while the lower portion can have a half angle as large as (90"0 - phi/sub w). Percolation of fines through shearing granular solids is briefly discussed and recommended ...

International Nuclear Information System (INIS)

The paper discusses recent results on the development of localized arc filament plasma actuators and their use in controlling high-speed and high Reynolds number jet flows. Multiple plasma actuators (up to 8) are controlled using a custom-built 8-channel high-voltage pulsed plasma generator. The plasma generator independently controls pulse repetition rate (0-200 kHz), duty cycle and phase for each individual actuator. Current and voltage measurements demonstrated the power consumption of each actuator to be quite low (20 W at 20% duty cycle). Emission spectroscopy temperature measurements in the pulsed arc filament showed rapid temperature increase over the first 10-20 ?s of arc operation, from below 1000 deg. C to up to about 2000 deg. C. At longer discharge pulse durations, 20-100 ?s, the plasma temperature levels off at approximately 2000 deg. C. Modelling calculations using an unsteady, ...

International Nuclear Information System (INIS)

A nuclear power plant engineering (NPP) simulator may include many system functions such as thermal-hydraulic calculation, 3D reactor neutron kinetics model, control and protection system, display and operational human-machine interface, intelligent alarm system, etc. If all those functions are simulated using a single code, the size of the program will cause structural or managerial problems, and the hardware requirement could be tremendous. Thus, any local function errors or changes may affect the whole code, which will make development and maintenance extremely costly. So the nondistributed code is not considered to be flexible and feasible. Currently, distributed and parallel technologies have been applied to develop NPPs engineering simulator for safety analysis, verification of advanced main control room display, operation and intelligent alarm design. The distributed simulation divides a huge task into several objects according to ...

British Library Electronic Table of Contents (United Kingdom)

With the advent of computer technology, researchers and instructors are attempting to devise computer support for effective collaborative technical writing. In this study, a computer-supported environment for collaborative technical writing was developed. This system (Process-Writing Wizard) provides process-oriented scaffolds and a synchronous online chat room to facilitate real-time collaborative writing practice. It allows multiple students to work synchronously on collaborative writing tasks via the Internet. It also helps develop collaborative writing strategies, such as creating team agendas, brainstorming, creating team outlines, and generating team articles. An experiment was conducted to examine the effect of the system on EFL (English as a Foreign Language) students? collaborativ...

Science.gov (United States)

In 2009 the European Space Agency satellite mission GOCE (Gravity Field and Steady-State Ocean Circulation Explorer) was launched. Its objectives are the precise and detailed determination of the Earth's gravity field and geoid. Its core instrument, a three axis gravitational gradiometer, measures the gravity gradient components V xx , V yy , V zz and V xz (second-order derivatives of the gravity potential V) with high precision and V xy , V yz with low precision, all in the instrument reference frame. The long wavelength gravity field is recovered from the orbit, measured by GPS (Global Positioning System). Characteristic elements of the mission are precise star tracking, a Sun-synchronous and very low (260 km) orbit, angular control by magnetic torquing and an extremely stiff and thermally stable instrument environment. GOCE is complementary to GRACE (Gravity Recovery and Climate Experiment), another satellite gravity mission, ...

UK PubMed Central (United Kingdom)

The ability to respond to stress is at the core of an organism's survival. The hormones epinephrine and norepinephrine play a central role in stress responses in mammals, which require the synchronized...Full Text Available

Science.gov (United States)

The progress of digital audio technology enabled the familiar use of the products such as CD and DAT in the acoustic measurement. For example, a signal reproduced with CD player is inputted into a subject of measurement and DAT recorder records its response. However, the sampling cannot be synchronized completely with the input signal although both nominal sample rates are set up equally, because player and recorder work independently. It is the most popular software solution to perform the synchronous addition after converting the recorded signal into the original sampling rate. However, the rate conversion also has the error due to the windowing in the high frequency region of processed signal. This paper proposes a new method for averaging asynchronous sampling data to solve these problems. To evaluate performance, the transfer function of only measuring equipment estimated from asynchronous sampling data was compared with the measuring ...

CERN Document Server

This study explores a method to characterize temporal structure of intermittent phase locking in oscillatory systems. When an oscillatory system is in a weakly synchronized regime away from a synchronization threshold, it spends most of the time in parts of its phase space away from synchronization state. Therefore characteristics of dynamics near this state (such as its stability properties/Lyapunov exponents or distributions of the durations of synchronized episodes) do not describe system's dynamics for most of the time. We consider an approach to characterize the system dynamics in this case, by exploring the relationship between the phases on each cycle of oscillations. If some overall level of phase locking is present, one can quantify when and for how long phase locking is lost, and how the system returns back to the phase-locked state. We consider several examples to illustrate this approach: ...

British Library Electronic Table of Contents (United Kingdom)

This paper presents experimental investigations of the all-optical synchronization of a distributed Bragg reflector (DBR) laser self-pulsating at 40GHz on various injected bit-rate signals. Even though there is no modulation applied to this laser, it exhibits a modulation of its output emission, measured at 39.7GHz with a linewidth of 30MHz. Such performance is exploited in all-optical clock recovery for a return-to-zero data stream at 40Gbit/s. The SP-DBR laser wavelength and the injected signal wavelength are 10nm apart. All-optical synchronization is demonstrated at 40Gbit/s with a linewidth of less than 20MHz for injected signals at 10 and 20Gbit/s, respectively. Thus the SP-DBR laser proves to be very versatile and can be synchronized on various bit-rate data signals.

Energy Technology Data Exchange (ETDEWEB)

In this thesis a study is made of the of voltage characteristics and reactive power control in the transmission network of the Electric Power Systems (EPS) with static compensators of VARs (SCVs). The necessity of voltage and reactive power control and the application of SCVs as a solution means for three representative operation stages of the EPS, considering balanced operation conditions and fundamental frequency is analyzed: Operation in the presence of incremental voltage changes, quasi-stationary operation or steady state and behavior at the occurrence of big disturbances. The application of SCVs to systems of integral transmission is in general a closed loop control system, reason why the analysis of the interaction of the system EPS-SCV is considered as an essential part of the voltage and reactive power control study. Firstly, the response analysis of the ...

Energy Technology Data Exchange (ETDEWEB)

Individual nanoscale building blocks exhibit a wide range of size-dependent properties, since their size can be tuned over known characteristic length scales of bulk materials. In the last several years, the possibility of combining different materials in the form of two and three component nanoparticles (NPs) has been extensively explored. Also multi-component materials can be obtained via self-assembly of NPs from their binary colloidal mixtures. These new nanocrystal solids may possess tunable collective properties that originate from interactions between size and composition controlled building blocks. Exchange coupling between neighboring NPs of magnetically soft and hard materials enhances the magnetic energy product of the nanocomposite material. Randomly mixed solids of small and large semiconducting CdSe NPs revealed enhancement of photoluminescence intensity of large semiconductor particles accompanied by quenching of photoluminescence of the small ...

Energy Technology Data Exchange (ETDEWEB)

The advent of carbon nanotubes, which are graphite layers convoluted in cylinders several nanometers in diameter and several micrometers in length, as well as the experiments on implanting metal atoms in such tubes open the way to producing nanoconductors and other materials with unique properties. For theorists, the basic challenge is interpreting and predicting the structure and properties of these systems. The linearized augmented-plane-wave method (LAPW) is one of the most accurate methods in the theory of the electronic structure of solids. A generalization of this method for quasi-two-dimensional systems, surface electronic states, and layered crystals is known. The LAPW theory for quasi-unidimensional systems, which exhibit translational symmetry in one direction, has been absent thus far. In this paper, the authors suggest a version of such a theory and use this method to calculate the electronic structure of carbyne (a linear chain of ...

Energy Technology Data Exchange (ETDEWEB)

Seasonal traffic on intercity corridors often creates severe congestion at various bottlenecks, such as land-drops and drawbridges. A Traffic Simulation And Optimization model (TSAO) has been developed in order to 1) evaluate traffic impacts (including travel time, vehicle operating costs, accidents, air pollution and fuel consumption) of a given routing pattern on a network, and 2) determine the optimal flow pattern. In its latest version, the TSAO model uses: 1) a macroscopic simulation approach to trace vehicle platoons through a network; 2) Greenshield's equation to represent volume-speed relationship on freeways and multi-lane highways, and Highway Capacity Manual method for two-lane rural highways; 3) Lighthill's shockwave function to simulate queue propagation; 4) event-scan time management for simulation; 5) variable link capacity for two-lane rural highways or to stimulate incidents; 6) AASHTO Guideline for determining vehicle operating costs and fuel ...

Science.gov (United States)

The Quasi-Series Decomposition of Two-Terminal Graphs, Publ. Math. Debrecen., Vol. ...... Termination, Queueing, SIAM J. Appl. Math., Vol. 14, pp. 1390-. 1411, 1966. ..... Analysis of Discrete Markov Systems by Means of Stochastic ...

CERN Document Server

In this paper, for a given sequentially Yoneda-complete T_1 quasi-metric space (X,d), the domain theoretic models of the hyperspace K_0(X) of nonempty compact subsets of (X,d) are studied. To this end, the $\\omega$-Plotkin domain of the space of formal balls BX, denoted by CBX is considered. This domain is given as the chain completion of the set of all finite subsets of BX with respect to the Egli-Milner relation. Further, a map $\\phi:K_0(X)\\rightarrow CBX$ is established and proved that it is an embedding whenever K_0(X) is equipped with the Vietoris topology and respectively CBX with the Scott topology. Moreover, if any compact subset of (X,d) is d^{-1}-precompact, \\phi is an embedding with respect to the topology of Hausdorff quasi-metric H_d on K_0(X). Therefore, it is concluded that (CBX,\\sqsubseteq,\\phi) is an $\\omega$-computational model for the hyperspace K_0(X) endowed with the Vietoris and respectively the Hausdorff topology. ...

Energy Technology Data Exchange (ETDEWEB)

The two-dimensional WKB model has been the basis for several investigations of the quasi-Landau hydrogenic spectrum. Whereas other authors have used numerical integration, it is shown that the results can be obtained analytically in terms of elliptic integrals. The later are easily generated by even programmable pocket calculators, from which numerical results - which are in good agreement with experiments - are easily obtained. A further advantage of using elliptic integrals is that several strong-field problems can be shown to be special cases of a general potential whose energy and spacing are expressible in terms of them.

CERN Document Server

The recent measurements by the BES Collaboration of J/psi decays into a photon and a proton-antiproton pair indicate a strong enhancement at the proton-antiproton threshold not observed in the decays into a neutral pion and a proton-antiproton pair. Is this enhancement due to a proton-antiproton quasi-bound state or a baryonium? A natural explanation follows from a traditional model of proton-antiproton interactions based on G-parity transformation. The observed proton-antiproton structure is due to a strong attraction in the 1S0 state, and possibly to a near-threshold quasi-bound state in the 11S0 wave.

Energy Technology Data Exchange (ETDEWEB)

This paper presents a new method and newly developed stabilizing equipment to prevent the loss of synchronism of generators in pumped-storage plants from spreading. The proposed method includes functions to estimate the swing of each generator by using on-line generator output sampled at a rate of 600 times per second after an occurrence of disturbance such as fault, faulty equipment and so on, to predict generator swing 200-300 milliseconds ahead and loss of synchronism between generators in pumped-storage plants and those in thermal and nuclear plants, and to decide the number of generators that must be shed to maintain stability. Tokyo Electric Power Co. (TEPCO) installed the newly developed stabilizing equipment based on this method in the power system in June, 1986.

International Nuclear Information System (INIS)

Based on proposed models for the tidal spin-up and magnetic braking of stars with a convective outer envelope, it is suggested that the rotation of secondaries in cataclysmic variables is not necessarily synchronized with the orbital revolution. This may provide an explanation for the observed large range in the mass transfer rate (at the same orbital period) of cataclysmic variables above the period gap. (author).

Energy Technology Data Exchange (ETDEWEB)

It is shown that the existence of faster-than-light signals (tachyons) would imply the existence (and detectability) of a privileged inertial frame and that one can avoid all problems with reversed-time order only by using absolute synchronization instead of the standard one. The connection between these results and the EPR-paradox is discussed.

International Nuclear Information System (INIS)

A quadruply redundant synchronous fault tolerant processor (FTP) is now under fabrication at the C.S. Draper Laboratory to be used initially as a trip monitor for the Experimental Breeder Reactor EBR-II operated by the Argonne National Laboratory in Idaho Falls, Idaho. The real time operating system for this processor is described.

Science.gov (United States)

The dynamic behavior of electrooptic bistable devices with delayed feedback is investigated theoretically and experimentally. The operation principle of the system is analyzed by the method of iterated maps. Stable, bistable, periodic, higher periodic, and chaotic solutions are discussed and realized experimentally by using an integrated Mach-Zehnder interferometer on LiNbO3 as a basic nonlinear element. Taking into account the periodic modulator characteristic, the application of this device as a simple and fast bistable and monostable multivibrator is demonstrated. In addition, the synchronization properties of the astable multivibrator are investigated.

Science.gov (United States)

The state of chromatin during the cell cycle was examined using synchronized cultures of CHO hamster cells. Results support Mazia's dynamic chromosome cycle model and indicate that DNA-interactive chemotherapeutic agents elicit different types of kinetic responses in treated cells, suggesting a degree of specificity of interaction between various alkylating and intercalating agents and the genome. Effects of sarkosyl crystals, heparin, and chemotherapeutic agents, neocarzinostatin and adriamycin, on chromation are discussed. (HLW)

Science.gov (United States)

Based on our cryogenic FT-IR spectroscopic studies of hydrogen bonds in cholic acid, the two-dimensional FT-IR spectroscopy was applied to enhance our understanding of the hydrogen bonds. Fine spectral structures were revealed by asynchronous 2D FT-IR spectra. The co-relationship among various bands was discussed according to the synchronous 2D FT-IR spectra. .

CERN Document Server

We use a superspin Hamiltonian defined on an infinite-dimensional Fock space with positive definite scalar product to study localization and delocalization of noninteracting spinless quasiparticles in quasi-one-dimensional quantum wires perturbed by weak quenched disorder. Past works using this approach have considered a single chain. Here, we extend the formalism to treat a quasi-one-dimensional system: a quantum wire with an arbitrary number of channels coupled by random hopping amplitudes. The computations are carried out explicitly for the case of a chiral quasi-one-dimensional wire with broken time-reversal symmetry (chiral-unitary symmetry class). By treating the space direction along the chains as imaginary time, the effects of the disorder are encoded in the time evolution induced by a single site superspin (non-Hermitian) Hamiltonian. We obtain the density of states near the band center of an infinitely long ...

Energy Technology Data Exchange (ETDEWEB)

Outline of three dimensional design of axial turbine was explained with examples of its application. Quasi-three dimensional design which analyzed flow in meridian plane and flow between blades seperately, and three dimensional design which, based on the quasi-three dimensional design with considering cubical force, improved distribution of static pressure and optimized distribution of repulsion and aerodynamic force, were explained. For the numerical analysis, Euler's Code was applied. AS the example of application, expectable effect by negative angle of blade was calculated, and efficiencies of single stage turbines with static blades designed by each method were compared. As the practical application of three dimensional analysis of flow to designing, Endwall Contouring for static blade of initial stage was explained. 10 refs., 12 figs.

Science.gov (United States)

Apparent evolution of relativistic flows as traced by radio emission results from a combination of several factors related to propagation of relativistic blobs or shocks, velocity, density and pressure stratification of the underlying flow, plasma instability and (possibly also) phase and time travel effect. This combination can create an intricate and chaotic patterns of the observed morphological changes in radio emission, which complicates the analysis and interpretation of kinematic and physical properties of the jet plasma. Recent studies have indicated that slow and quasi-stationary patterns in jets are most likely formed by plasma instabilities while faster, superluminally moving patterns are related to highly relativistic plasma condensations produced by the nuclear flares. Some of the stationary patterns may also be related to recollimation shocks or locations where strong non-thermal continuum is produced in jets. Similarities and differences of the AGN ...

British Library Electronic Table of Contents (United Kingdom)

In this work, a highly-sensitive polymeric membrane ion selective electrode for determination of tetracycline was constructed by using molecularly imprinted polymer (MIP) particles as quasi-ionophore. The water-compatible MIP particles targeting tetracycline were synthesized with tetracycline as a template molecule, methacrylic acid as a functional monomer, ethylene glycol dimethacrylate as a cross-linker, 2,2?-azobisisobutyronitrile as an initiator and lanthanum ion as a mediator. Benefited from the distinctive performance of the quasi-ionophore and the optimized composition of the membrane and the inner filling solution, the lower detection limit of the electrode was decreased to about 1 ? 10?8 mol/l. It exhibited a good electrode slope 59.8 mV/decade near the theoretical Nernstian one, ...

CERN Document Server

Mono-layers of stearic and behenic acids deposited with the Langmuir-Blodgett technique, were used as aligning films in nematic liquid crystal cells. During the filling process the liquid crystal adopts a deformed quasi-planar alignment with splay-bend deformation and preferred orientation along the filling direction. This state is metastable and transforms with time into homeotropic once the flow has ceased. The transition is accompanied by formation of disclination lines which nucleate at the edges of the cell. The lifetime of the metastable splay-bend state was found to depend on the cell thickness. On heating, anchoring transition from quasi-homeotropic to degenerate tilted alignment in form of circular domains takes place near the transition to the isotropic phase. The anchoring transition is reversible with a small hysteresis.

International Science & Technology Center (ISTC)

Development of Frequency Controlled Electric Drives

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The synchronous orbit performance of Hughes Aircraft Company solar arrays is presented and compared with the results of ground based predictions for orbital durations of almost 11 years. Performances of the Intelsat IV*, IVA*, and Telesat (Anik) solar arrays are detailed. This paper is an update of the in-orbit performances previously reported in 1976 (1). The in-space performance data indicate solar array power degradation of 16.7 percent for Intelsat IV F-2 after 130 months in orbit, and 13.0 percent for Telesat F-1 after 85 months in orbit. The predicted output of each of these solar arrays is within 2 percent of the actual in-orbit performance of these systems. The Intelsat IV F-2 experienced the 4 August 1972 solar flare. The ability to accurately predict the performance of solar arrays within telemetry accuracy is demonstrated. This ability combines the electrical measurements of a solar array in the ''as built'' ...

Energy Technology Data Exchange (ETDEWEB)

A transient stability program was developed for the Taiwan Power Company, which has a high proportion of nuclear generation in its power system. This program offers a new territory to investigate nuclear plant effects on the power system transient stability. This program also provides a high speed tool for the Taipower system operational planning. A generalized procedure of synchronous machine modeling for a large-scale stability study is presented. The merits and weaknesses of machine modeling can be comprehended through each item of this procedure. Three types of nonlinear synchronous machine modeling implemented into this stability program are derived by following this procedure. A robust subroutine was derived to perform the fourth order Runge-Kutta integration method, making the software programming neat and systematical. For simulating the nuclear plant influence on the system, this program implemented an additional four functions: ...

CERN Document Server

A (n +1)-dimensional Einstein-Gauss-Bonnet (EGB) model is considered. For diagonal cosmological type metrics the equations of motion are reduced to a set of Lagrange equations. The effective Lagrangian contains two minisuperspace metrics on R^n. The first one is the well-known 2-metric of pseudo-Euclidean signature and the second one is the Finslerian 4-metric that is proportional to n-dimensional Berwald-Moor 4-metric. When a synchronous-like time gauge is considered the equations of motion are reduced to an autonomous system of first order differential equations. For the case of the pure Gauss-Bonnet model two exact solutions with power-law and exponential dependence of scale factors (w.r.t. synchronous-like variable) are obtained. In cosmological case the first solution was obtained earlier by A. Toporensky and P. Tretyakov for n = 5 (and verified for n = 6,7). A generalization of the effective Lagrangian to the Lowelock case is conjectured. ...

Science.gov (United States)

A technique is presented for the analyss of DNA histograms which is an extension of earlier discrete Gaussian summing methods. It alleviates the problems encountered with previous methods by extending the S-phase portions of the distribution under the G/sub 1/ and G/sub 2/ + M peaks. The resuts obtained by this method for the fraction of cells in the G/sub 1/, S, and G/sub 2/ + M phases of the life cycle are compared with autoradiographic results. With one or two exceptions which are discussed, agreement between autoradiography and the analytical method is good.

Energy Technology Data Exchange (ETDEWEB)

The gravitational radiation produced by the big bang is calculated in order to provide a condition for the unification of the gravitational and electromagnetic forces. By analogy with electromagnetic radiation and under the assumption that gravity is also quantized, it is shown that matter would have decoupled from gravitational radiation at a time of approximately 10 to the -43rd sec and would have dominated it at 10 to the -17th sec. Furthermore, the theory predicts a background gravitational radiation temperature of 0.003 K which peaks at a wavelength of about 1 m, which may be detected by the comparison of the synchronization of clocks at increasing distances.

Energy Technology Data Exchange (ETDEWEB)

The mutual inductance between parallel transmission lines influences the locating of the transmission line faults. A fault location algorithm for parallel lines developed in this paper takes into account the magnetic coupling between parallel lines. The paper presents a detailed description of the developed algorithm and test results performed on a simplified real transmission line. The obtained error is less than 0.5 percent in most cases. Also, the developed algorithm is not sensitive to typical fault parameters, such as: resistance, type, location, and incidence angle. 7 refs, 4 figs, 12 tabs

International Nuclear Information System (INIS)

The dependence of Tsub(c) on composition and deformation is calculated and compared with the corresponding dependence for Tsub(m). It is shown that superconducting and structural properties of A-15 compounds can be described, at least qualitatively, by the quasi-one-dimensional model previously developed by the authors. The superconductivity mechanism is assumed to be analogous to the BCS theory. The upper critical field Hsub(c2) of the V_3Si or Nb_3Sn compounds is found to be much greater than that in V or Nb.

International Nuclear Information System (INIS)

The quark structure of constituent nucleons is considered by a qualitative comparison of features of different models with experimental data with respect to cumulative meson production. It is shown that the fluctuation of the density of nuclear matter, ie the creation and disintegration of a short lived few-nucleon correlation (flucton), is a type of the quasi-resonance formation in the nucleus which exists without any connection with the incident particle. The cumulative production in the region under investigation is mostly the result of a Regge type dissociation of the flucton. (U.K.).

Energy Technology Data Exchange (ETDEWEB)

Transient enhanced diffusion in boron-implanted silicon is interpreted as being due to the fact that during rapid thermal annealing a relaxation process takes place, associated with quasi-chemical reactions including defects. A simple analytical model makes it possible to describe the annealing mechanism on a microscopic scale in terms of reaction-diffusion processes. The measured dependences of the boron diffusion coefficient of the enhanced diffusion on time, temperature and implantation energy are satisfactorily explained. (author).

International Nuclear Information System (INIS)

It is shown that both the Tsub(c) and Tsub(m) dependences on the deformations and composition for the A-15 compounds can be described at least qualitatively in the quasi-one-dimensional model developed by the authors previously. The mechanism for the superconductivity is supposed to be the same as in the BCS theory. The upper critical field near Tsub(c) is obtained. (author).

CERN Document Server

We show that on any abelian scheme over a complex quasi-projective smooth variety, there is a Green current for the zero-section, which is axiomatically determined up to $\\partial$ and $\\bar\\partial$-exact differential forms. This current generalizes the Siegel functions defined on elliptic curves. We prove generalizations of classical properties of Siegel functions, like distribution relations, limit formulae and reciprocity laws.

International Nuclear Information System (INIS)

It is shown that the section of the energy surface corresponding to the longitudinal mode by the principal xy-plane for the A-15 compounds will degenerate into four points at the corners of a square at very low temperatures in the cubic phase. When the quasi-shear mode propagating along the (110) direction becomes soft, simultaneously the longitudinal mode will exhibit unusually high phonon focussing. (author).

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The authors summarize EUVE's contribution to the study of the boundary layer emission of high accretion-rate nonmagnetic cataclysmic variables, especially the dwarf novae SS Cyg, U Gem, VW Hyi, and OY Car in outburst. They discuss the optical and EUV light curves of dwarf nova outbursts, the quasi-coherent oscillations of the EUV flux of SS Cyg, the EUV spectra of dwarf novae, and the future of EUV observations of cataclysmic variables.

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The correlation between baryon number and strangeness elucidates the nature of strongly interacting matter. This diagnostic can be extracted theoretically from lattice QCD calculations and experimentally from event-by-event fluctuations. The analysis of present lattice results above the critical temperature severely limits the presence of q{bar q} bound states, thus supporting a picture of independent (quasi)quarks. Details may be found in [1].

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 one-end algorithms were ...

International Nuclear Information System (INIS)

Neutron radiography (NR) is a useful non-destructive method for determination of hydrogen content in various building and technical materials. Monitoring of transport processes of moisture and hydrogenous liquids in porous building materials is enabled by fast, quasi-real-time NR methods based on novel imaging plate neutron detectors (IP-NDs). Hydrogen content in the samples is determined by quantitative analysis of measured profiles of neutron attenuation in the samples. Detailed description of quantitative NR method is presented by the authors in another accompanying contribution at this conference. Deterioration of building materials is originated by different processes that all require presence of water therefore it is essential to limit or prevent the transport of water through the porous material. In this presentation, results of a study of clay brick impregnation by silicone based hydrophobic agents will be presented. Quantitative results obtained by NR ...

International Nuclear Information System (INIS)

The effect of resonance, observed in X-ray waveguide layered structures in a characteristic way influences the scattering properties of the films. It is well known that the resonant region in the reflectivity shows a series of minima, usually very deep and extremely narrow. The positions and depths of the minima depend only on X-ray waveguide and quasi X-ray waveguide film structural properties, on the X-ray wavelength and on the incident beam divergence. In the present work we propose and discuss the application of the X-ray waveguide and quasi X-ray waveguide film structures as a tools to experimental evaluation of some quantities related to X-ray reflectometric and diffractometric measurements, like the beam divergence, wavelength, or angular distance. Examples of application of X-ray waveguide as an excellent tool for estimate the effective beam divergence are shown. Properties of the X-ray waveguide elements as a handy wavelength or ...

CERN Document Server

We report $^{7}$Li pulsed NMR measurements in polycrystalline and single crystal samples of the quasi one-dimensional S=1 antiferromagnet LiVGe$_2$O$_6$, whose AF transition temperature is $T_{\\text{N}}\\simeq 24.5$ K. The field ($B_0$) and temperature ($T$) ranges covered were 9-44.5 T and 1.7-300 K respectively. The measurements included NMR spectra, the spin-lattice relaxation rate ($T_1^{-1}$), and the spin-phase relaxation rate ($T_2^{-1}$), often as a function of the orientation of the field relative to the crystal axes. The spectra indicate an AF magnetic structure consistent with that obtained from neutron diffraction measurements, but with the moments aligned parallel to the c-axis. The spectra also provide the $T$-dependence of the AF order parameter and show that the transition is either second order or weakly first order. Both the spectra and the $T_1^{-1}$ data show that $B_0$ has at most a small effect on the alignment of the AF moment. There is no ...

International Nuclear Information System (INIS)

Total longitudinal momentum of all registered particles, their total energy and other summary kinematics variables are used for separation of the events with two- and three-quasi-nucleon collisions from the C+C, C+p, d+C, and p+C interactions at 4.2 (GeV/c)/N. The research results on charged particle multiplicity and their momentum spectra lead to the conclusion that nearly 60% of all three-quasi-nucleon events are due to collisions where two nucleons behave like a whole object, called flucton, which has been predicted by D.I.Blokhintsev. Mean values of one-particle longitudinal momenta of the products and their mean multiplicities for the subreactions in which fluctons take part are lower by #approx#30% compared to the subreactions where two nucleons interact not as a whole object, but in a successive way. Production of the cumulative particles is due to flucton interactions, especially when fluctons are used as a target

CERN Document Server

The General Spectral Modeling (GSM) code employs the quasi-static approximation, a standard, low-density methodology that assumes the ionization balance is separable from a determination of the excited-state populations that give rise to the spectra. GSM also allows for some states to be treated only as contributions to effective rates. While these two approximations are known to be valid at low densities, this work investigates using such methods to model high-density, non-LTE emission spectra and determines at what point the approximations break down by comparing to spectra produced by the LANL code ATOMIC which makes no such approximations. As both approximations are used by other astrophysical and low-density modeling codes, the results should be of broad interest. He-like K$\\alpha$ emission spectra are presented for Ni, Fe, and Ca, in order to gauge the effect of both approximations employed in GSM. This work confirms that at and above the temperature of ...

British Library Electronic Table of Contents (United Kingdom)

ArgoNeuT, a Liquid Argon Time Projection Chamber (LAr-TPC), has recently collected thousands of neutrino and anti-neutrino events between 0.1 and 10 GeV in the NuMI beamline at Fermilab (FNAL). Among other issues, the experiment will measure the cross section of the neutrino and anti-neutrino Charged Current Quasi-Elastic (CCQE) interaction on Ar target and analyze the vertex activity associated with such events. Outcomes from the reconstruction of the events provide the main subject of this paper.

CERN Document Server

We present a dynamical spectral model for Large Eddy Simulation of the incompressible magnetohydrodynamic (MHD) equations based on the Eddy Damped Quasi Normal Markovian approximation. This model extends classical spectral Large Eddy Simulations for the Navier-Stokes equations to incorporate general (non Kolmogorovian) spectra as well as eddy noise. We derive the model for MHD and show that introducing a new eddy-damping time for the dynamics of spectral tensors in the absence of equipartition between the velocity and magnetic fields leads to better agreement with direct numerical simulations, an important point for dynamo computations.

International Nuclear Information System (INIS)

Using the slow electrons spectrometer one can get information on the surface structure, its element composition, chemical bonds, adsorption phenomena, electron state density and surface oscillation. We have developed the methods and created the apparatus that makes it possible to investigate the electron backscattering by solid surface. We have studied the electron scattering by the polycrystalline and monocrystalline. GaAs surface in the energy range of 0 to 9 eV. The FWHM of electron energy distribution function was 70 meV. (author).

Energy Technology Data Exchange (ETDEWEB)

A plane stress constitutive relation is developed for laminate composites undergoing matrix cracking and therefore displaying significant nonlinear stress-strain behavior. The constitutive relation is similar in some respects to a phenomenological theory of plasticity in that it is fit to data from uniaxial tests. The constitutive equations are specialized to brittle matrix composites (especially CMCs) in the form of cross-piles and quasi-isotropic laminates. Several problems involving stress redistribution at holes and notches due to nonlinear stress-strain behavior are investigated with the aid of the constitutive law.

International Nuclear Information System (INIS)

In CsCdBr_3, Tm"3"+ substitutes for Cd"2"+. It predominately forms symmetric dimer centers and single-ion centers, both of trigonal symmetry. The energy level schemes of both centers were determined by EPR and site-selective laser spectroscopy. To describe the spectra term dependent crystal-field parameters were deduced on the basis of a microscopic model taking into account the local lattice deformation induced by the impurity centers and the quasi-resonant virtual scattering of intrinsic lattice excitations by the Tm"3"+ ions. (orig.)

Energy Technology Data Exchange (ETDEWEB)

This study examines the effects of blasting on waste dumps at open pit mining operations. Of specific concern were mining operations at the base of a five hundred foot high waste dump such as the operation at the South Pit of the Smoky-River Coal Ltd. property near Grande Cache, Alberta. An assessment of waste dump stability including factors such as quasi-static deformation behaviour, historical dump deformation behaviours and potential blasting effects was undertaken. It is concluded that safe blasting may be carried out in proximity to waste dumps, but monitoring of dump behaviour is recommended to ensure operational safety. 22 refs., 4 apps.

International Nuclear Information System (INIS)

"2H, "4He, "1"6O, "4"0Ca, "8"0Zr, "1"4"0Yb, "2"2"4112, "3"3"6168 nuclei are invesigated in terms of flucton model. Effective numbers of nuclear fluctons and deuterons are calculated. Values of complete effective numbers of low-radius deuterons and fluctons with S=1 spin and T=0 isospin are presented. Investigation results of inclusive reactions of quasi-elastic knock-out of deuterons by fast protons are discussed. 9 refs.; 1 fig.; 1 tab.

International Nuclear Information System (INIS)

The high-spin states in transitional odd-mass nuclei are studied in terms of an odd quasi-particle coupled to an asymmetric rotor with a variable moment of inertia (VMI). In order to take into account the VMI, the basis states are expanded in terms of the core eigenfunctions. Excitation energies, quadrupole moments, magnetic moments, B(E2) values and B(M1) values are calculated and compared with the experimental data for nuclei in Au and La regions. On comparison with other descriptions it is found that the treatment with VMI provides a more satisfactory explanation of the data. (Auth.).

British Library Electronic Table of Contents (United Kingdom)

A twin unidirectional impulse turbine has been proposed in order to enhance the performance of wave energy plant. This turbine system uses two unidirectional impulse turbines and their flow direction is different from each other. However, the turbine characteristics have not been clarified to date. The performances of a unidirectional impulse turbine under steady flow conditions were investigated experimentally by using a wind tunnel with large piston/cylinder in this study. Then, efficiency of the twin impulse turbine have been estimated by a quasi-steady analysis using experimental results.

International Nuclear Information System (INIS)

... v. 15(10) p. 445-449. automation control equipment fluid flow fluidic control

International Nuclear Information System (INIS)

Spectral room temperature photoluminescence (pl) of polycrystalline Cu(In,Ga)Se2 films (CIGSe) is evaluated with respect to optoelectronic properties and in particular for the determination of the splitting of quasi-Fermi levels (EFn - EFp). For lateral resolution of ? 1 ?m a confocal pl-setup is used. The depth profile of the excess carrier densities determining the rates of radiative transitions strongly govern the spectral pl-shape which has been numerically modeled with a matrix transfer formalism. In this optical approach we discriminate for wave propagation and attenuation in a multilayer system between a plane-wave ansatz and a 3D-spherical formalism, depending on excitation area large or small/similar compared to the thickness of the absorber. In both cases re-absorption of photons in energetic regimes with absorption approaches unity, from which the splitting of the quasi-Fermi levels is preferentially deduced, substantially influence ...

Science.gov (United States)

Title list.

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 the ELMSYS PC platform

British Library Electronic Table of Contents (United Kingdom)

As organizations merge or collaborate closely, an important question is how their existing software assets should be handled. If these previously separate organizations are in the same business domain - they might even have been competitors - it is likely that they have developed similar software systems. To rationalize, these existing software assets should be integrated, in the sense that similar features should be implemented only once. The integration can be achieved in different ways. Success of it involves properly managing challenges such as making as well founded decisions as early as possible, maintaining commitment within the organization, managing the complexities of distributed teams, and synchronizing the integration efforts with concurrent evolution of the existing systems.Th...

British Library Electronic Table of Contents (United Kingdom)

Aim To better define the indications for adrenalectomy for adrenal metastasis we have analysed factors predicting survival in our institutional series. Methods A consecutive series of 30 patients undergoing adrenalectomy for metastasis (1996-2007), excluding patients with simultaneous ipsilateral renal cell carcinoma (RCC), was studied. Metastases were regarded as synchronous (6 mo), depending on the interval after primary surgery. Survival was calculated from time of adrenalectomy and factors influencing survival were identified. Results The tumour diagnoses were RCC n = 9, malignant melanoma n = 5, non-small-cell lung cancer n = 5, colorectal carcinoma n = 4, foregut carcinoid n = 2, adrenocortical carcinoma, breast cancer, hepatocellular carcinoma, urothelial c...

CERN Document Server

A recurrent idea in the study of complex systems is that optimal information processing is to be found near bifurcation points or phase transitions. However, this heuristic hypothesis has few (if any) concrete realizations where a standard and biologically relevant quantity is optimized at criticality. Here we give a clear example of such a phenomenon: a network of excitable elements has its sensitivity and dynamic range maximized at the critical point of a non-equilibrium phase transition. Our results are compatible with the essential role of gap junctions in olfactory glomeruli and retinal ganglionar cell output. Synchronization and global oscillations also appear in the network dynamics. We propose that the main functional role of electrical coupling is to provide an enhancement of dynamic range, therefore allowing the coding of information spanning several orders of magnitude. The mechanism could provide a microscopic neural basis for psychophysical laws.

British Library Electronic Table of Contents (United Kingdom)

Animal studies demonstrated the powerful impact of maternal-infant social contact on the infant's physiological systems, yet the online effects of social interactions on the human infant's physiology remain poorly understood. Mothers and their 3-month old infants were observed during face-to-face interactions while cardiac output was collected from mother and child. Micro-analysis of the partners' behavior marked episodes of gaze, affect, and vocal synchrony. Time-series analysis showed that mother and infant coordinate heart rhythms within lags of less than 1s. Bootstrapping analysis indicated that the concordance between maternal and infant biological rhythms increased significantly during episodes of affect and vocal synchrony compared to non-synchronous moments. Humans, like other mamm...

British Library Electronic Table of Contents (United Kingdom)

The perceptual center (P-center) is fundamental to the timing of heterogeneous event sequences, including music and speech. Unfortunately, there is currently no comprehensive and reliable model of P-centers in acoustic events, so P-centers must instead be measured empirically. This study reviews existing measurement methods and evaluates two methods in detail?the rhythm adjustment method and a new method based on the phase correction response (PCR) in a synchronous tapping task. The two methods yielded consistent P-center estimates and showed no evidence of P-center context dependence. The PCR method appears promising because it is accurate and efficient and does not require explicit perceptual judgments. As a secondary result, the magnitude of the PCR is shown to vary systematically with ...

CERN Document Server

Entanglement swapping allows to establish entanglement between independent particles that never have interacted nor share a common past. This feature makes it an integral constituent of quantum repeaters and a promising tool for future tests of the foundations of quantum physics. Here, we demonstrate entanglement swapping with time-synchronized independent sources with a fidelity high enough to violate a Clauser-Horne-Shimony-Holt (CHSH) inequality by more than four standard deviations. The fact that both entangled photon pairs are created by fully independent laser sources, which are only electronically connected, ensures that this technique is suitable for future long-distance entanglement swapping and quantum-repeater experiments.

Energy Technology Data Exchange (ETDEWEB)

A design of a compact free-electron laser (FEL), generating ultra-fast, high-peak flux, XUV pulses is presented. The FEL is driven by ahigh-current, 0.5 GeV electron beam from the Lawrence Berkeley National Laboratory (LBNL) laser-plasma accelerator, whose active acceleration length is only a few centimeters. The proposed ultra-fast source (~;;10 fs) would be intrinsically temporally synchronized to the drive laser pulse, enabling pump-probe studies in ultra-fast science. Owing to the high current (>10 kA) of the laser-plasma-accelerated electron beams, saturated output fluxes are potentially greater than 10^13 photons/pulse. Devices based both on self-amplified spontaneous emission and high-harmonic generated input seeds, to reduce undulator length and fluctuations, are considered.

Energy Technology Data Exchange (ETDEWEB)

We present preliminary analysis for the feasibility of the attosecond x-ray pulses at a proposed FERMI@ELETTRA free electron laser (FEL) [1]. In part 1 we restrict ourselves to minimal modifications to the proposed FEL and consider a scheme for attosecond x-ray production which can be qualified as a small add-on to a primary facility. We demonstrate that at 5-nm wavelength our scheme is capable for production of pulses with an approximate duration of 100 attoseconds at approximately 2 MW peak power and with an absolute temporal synchronization to a pump laser pulse. In part 2 we propose to use an FEL amplifier seeded by a VUV signal and to follow it by the scheme for attosecond x-ray production described in part 1.

British Library Electronic Table of Contents (United Kingdom)

Synchronized cultures of the green alga Scenedesmus quadricauda were grown in the absence (untreated cultures) or in the presence (FdUrd-treated cultures) of 5-fluorodeoxyuridine, the specific inhibitor of nuclear DNA replication. The attainment of commitment points, at which the cells become committed to nuclear DNA replication, mitosis and cellular division, and the course of committed processes themselves were determined for cell cycle characterization. FdUrd-treated cultures showed nearly unaffected growth and attainment of the commitment points, while DNA replication(s), nuclear division(s) and protoplast fission(s) were blocked. Interestingly, the FdUrd-treated cells possessed a very high mitotic histone H1 kinase activity in the absence of any nuclear division(s). Compared with the ...

Energy Technology Data Exchange (ETDEWEB)

A new principle of particle trapping in the simple spherical cavity using both electric and magnetic components of radiofrequency electromagnetic field is proposed. The electric component of H {sub 12} oscillating mode drives the fast particle oscillations, while the magnetic component synchronously bends the trajectories to the cavity center. A specially developed theory of particle stability predicts dense and energetic electron cluster in the trap. Numerical simulations of particle dynamics in the complete electromagnetic field taking into account both space charge and particle-induced magnetic field are in good agreement with the analytic results, giving a density of 2.6*10{sup 1} electrons/cm{sup 3} and an average kinetic energy of around 30 keV at an operating frequency of 3 GHz. Being used at lower frequency, spherical cavity can trap protons and heavier ions too, but with lower density and kinetic energy.

KoreaScience (Korea)

Full Text Available

CERN Document Server

Randomized Algorithms for Analysis and Control of Uncertain Systems

International Nuclear Information System (INIS)

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

Science.gov (United States)

It is shown that, although accelerometer control systems are not well-posed in the sense of Salamon,

International Science & Technology Center (ISTC)

Commercial Production and Development, in Entomopathogenic Nematodes in Biological Control

CERN Document Server

Control of Phosphorus Transient Enhanced Diffusion using Co-implantation

International Nuclear Information System (INIS)

An outline of the instrumentation and control systems associated with fuelling machines is given. The control systems such as hydraulic system, oil hydraulic system, electric control system and the remote control systems have been discussed in detail. The difference between RAPP and MAPP fuel handling control systems has been explained. A computer based system for the Narora fuel handling control system is also discussed. (S.K.K.).

British Library Electronic Table of Contents (United Kingdom)

This article presents a decentralized control scheme for the complex problem of simultaneous position and internal force control in cooperative multiple manipulator systems. The proposed controller is composed of a sliding mode control term and a force robustifying term to simultaneously control the payloads position/orientation as well as the internal forces induced in the system. This is accomplished independently of the manipulators dynamics. Unlike most controllers that do not require prior knowledge of the manipulators dynamics, the suggested controller does not use fuzzy logic inferencing and is computationally inexpensive. Using a Lyapunov stability approach, the controller is proven to be robust in the face of varying systems dynamics. The payloads position/orientation and the inte...

International Nuclear Information System (INIS)

An analysis of the total photoabsorption cross section for nuclei ranging from "4He up to "2"3"8U has been performed in the energy range 0.2-1.0 GeV. Mean total photoabsorption cross sections have been obtained by summing up the contributions from partial photoreactions, and found to follow an A"1-dependence in the 0.2-1.0 GeV range. A review of the available total photoabsorption cross section data is also presented. Comparisons have been made with cross section values calculated by considering both the quasi-deuteron and #pi#-meson photoproduction mechanism of primary nuclear photointeraction. (orig.).

Energy Technology Data Exchange (ETDEWEB)

Results from the asymmetric reactions 80 and 100 MeV/uLa + C are presented and compared to earlier work with the same system at 18 and 50 MeV/u. Fragment-fragment correlations, cross sections, and distributions in velocity space indicate the continued dominance of a quasi-binary decay mechanism with increased emission of light charged particles. The distributions in velocity also indicate a progression toward a ''fireball'' type of reaction mechanism. However, the angular distributions of the emitted fragments are incompatible with statistical production mechanisms that have successfully explained the lower energy results, and indicate the dynamical nature of the emission process. Dalitz plots of triple complex fragment coincidences are presented in order to investigate the nature of the multibody decays. 18 refs., 9 figs.

British Library Electronic Table of Contents (United Kingdom)

We present modeling, simulation, and characterization for the dynamic response of clamped-clamped microbeams under mechanical shock. A Galerkin-based reduced-order model is utilized and its results are verified by comparing to finite-element results. The results indicate that the response of a microbeam to mechanical shock is inherently non-linear because of the dominating effect of mid-plane stretching. The effect of the shock pulse shape is investigated. It is concluded that the shape of the shock pulse can result in significant dynamic amplification in the response of the microbeam even in cases where the shock load is considered quasi-static.The combined effect of the electrostatic force and mechanical shock is investigated. The results show that this combined effect can lead to early ...

British Library Electronic Table of Contents (United Kingdom)

The microdynamics of soliton waves and localized modes of nonlinear vibrations of the acoustic and optical types in uranium nitride has been investigated. It has been shown that, with an increase in the excitation energy in the spectral gap between the bands of optical and acoustic phonons, the energies of solitons increase, whereas the energies of local modes decrease. The previously experimentally observed unidentified quasi-resonant features, which shift in the gap with variations in the temperature, can represent the revealed soliton waves and local modes. The microdynamics of heat conduction of uranium nitride has been studied for the stochastic generation of soliton waves and local modes in the case of spatially distant energy absorption. The thermal conductivity coefficient determin...

CERN Document Server

Within a fully relativistic framework, we derive and solve numerically the perturbation equations of relativistic stars, including the stresses produced by a non-vanishing shear viscosity in the stress-energy tensor. With this approach, the real and imaginary parts of the frequency of the modes are consistently obtained. We find that, approaching the inviscid limit from the finite viscosity case, the continuous spectrum is regularized and we can calculate the quasi-normal modes for stellar models that do not admit solutions at first order in perturbation theory when the coupling between the polar and axial perturbations is neglected. The viscous damping time is found to agree within factor 2 with the usual estimate obtained by using the eigenfunctions of the inviscid limit and some approximation for the energy dissipation integrals. We find that the frequencies and viscous damping times for relativistic $r-$modes lie between the Newtonian and Cowling results. We ...

Energy Technology Data Exchange (ETDEWEB)

We present a phenomenological model of the quark-hadron transition in neutrino-nucleon scattering. Using recently extracted weak nucleon transition form factors, we investigate the extent to which local and global quark-hadron duality is applicable in the neutrino F{sub 1}, F{sub 2} and F{sub 3} structure functions, and contrast this with duality in electron scattering. Our findings suggest that duality works relatively well for neutrino-nucleon scattering for the F{sub 2} and F{sub 3} structure functions, but not as well for F{sub 1}. We also calculate the quasi-elastic, resonance and deep inelastic contributions to the Adler sum rule, and find it to be satisfied to within 10% for 0.5 < Q{sup 2} < 2 GeV{sup 2}.

International Nuclear Information System (INIS)

A multiwire proportional counter type detector with thin slits instead of wires is presented. It can detect either charged particles (positive or negative) or radiation. The detector can be used as a counter or as an image converter. In radiography, it can replace photographic film or TV camera systems. It can also be used to measure particle or radiation energy. The slits which replace wires in the anode are introduced between two parallel microstrip conductors with different potentials. A quasi-polar electric field is produced between these strips. To obtain high fields, the slits are extremely narrow. Microstrips less than a micron can be obtained, giving structural dimensions of a few microns, i.e., 100 times smaller than the spacing in a classic wire anode.

CERN Document Server

The Eady problem of baroclinic instability as applicable to quasi-geostrophic oceanic flows with zero internal PV gradients is revisited by introducing a mild slope and Ekman pumping on the lower boundary. The solution behaviour is determined by the isopycnal slope relative to either the bottom slope or the ratio of Ekman depth to horizontal wavenumber. Attention is paid to the physical interpretation of the growing, decaying and stable disturbances, with emphasis on the intimate connection between the quasigeostrophic edge waves and Eady waves, and the role of the isopycnal slope for the stability properties as opposed to the bottom density gradient. The disturbance structure is found to be strongly influenced by the boundary conditions. For a sloping bottom boundary, the growth rate is enhanced for the most unstable waves if the isopycnals tilt in the same direction as the bottom, but in general non-standard boundary conditions tend to retard the growth of ...

British Library Electronic Table of Contents (United Kingdom)

We investigate two routes to obtain negative group velocity bands in two-dimensional phononic crystal structures. The negative dispersion originates from the resonances of sub-wavelength building blocks and as such, the system should be regarded as acoustic metamaterials. The first kind of acoustic metamaterial exhibits effectively negative bulk modulus and negative mass density simultaneously. Monopolar and dipolar Mie resonances are combined to achieve an effective medium with negative refractive index. In particular, we present a double negative metamaterial for airborne sonic waves. We then show that we can obtain negative group velocity from quadrupole resonances, and the result is explained using the quasi-static approximation. The negative dispersion in quadrupole bands cannot be de...

British Library Electronic Table of Contents (United Kingdom)

Abstract In this paper we propose a smooth transition tree model for both the conditional mean and variance of the short-term interest rate process. The estimation of such models is addressed and the asymptotic properties of the quasi-maximum likelihood estimator are derived. Model specification is also discussed. When the model is applied to the US short-term interest rate we find: (1) leading indicators for inflation and real activity are the most relevant predictors in characterizing the multiple regimes' structure; (2) the optimal model has three limiting regimes. Moreover, we provide empirical evidence of the power of the model in forecasting the first two conditional moments when it is used in connection with bootstrap aggregation (bagging). Copyright 2010 John Wiley & Sons, Ltd.

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A theoretical analysis of formation and symmetry transformations is presented for Wigner molecules with N = 2,..., 20 electrons confined in quantum dots at high magnetic fields. Using the unrestricted Hartree-Fock method with the multicentre Gaussian basis, we have found that Wigner molecules with N {>=} 6 abruptly change their shape and symmetry with an associated jump in the first derivative of the ground-state energy, i.e. they undergo phase transitions. In particular, the phases of the Wigner molecules obtained just after emerging from the maximum-density droplet (MDD) phase possess a different symmetry from that formed at a high magnetic field. We show that the properties of the electron-electron interaction energy demonstrate very well both the breakdown of the MDD and the quasi-classical character of the Wigner molecule in the high magnetic field. Possible mechanisms of the MDD decay are discussed.

International Nuclear Information System (INIS)

The cross-over from a magnetically ordered to a non-magnetic spin liquid state has been investigated in a series of resistance measurements under hydrostatic pressures of up to 30 kbar and at temperatures down to below 200 mK in the heavy fermion antiferromagnet CePd_2Si_2. The electrical resistivity changes dramatically with increasing pressure. Near the critical pressure, at which the magnetic ordering temperature is extrapolated to zero, it exhibits a quasi-linear variation over two orders of magnitude in temperature. This non-Fermi liquid form of #rho#(T) extends down to the onset of a new superconducting transition below 430 mK. (orig.).

Energy Technology Data Exchange (ETDEWEB)

In CsCdBr{sub 3}, Tm{sup 3+} substitutes for Cd{sup 2+}. It predominately forms symmetric dimer centers and single-ion centers, both of trigonal symmetry. The energy level schemes of both centers were determined by EPR and site-selective laser spectroscopy. To describe the spectra term dependent crystal-field parameters were deduced on the basis of a microscopic model taking into account the local lattice deformation induced by the impurity centers and the quasi-resonant virtual scattering of intrinsic lattice excitations by the Tm{sup 3+} ions. (orig.) 22 refs.

CERN Document Server

Classic and recent results for gauge effects on the properties of the normal-to-superconducting phase transition in bulk and thin film superconductors are reviewed. Similar problems in the description of other natural systems (liquid crystals, quantum field theory, early universe) are also discussed. The relatively strong gauge effects on the fluctuations of the ordering field at low spatial dimensionality D and, in particular, in thin (quasi-2D) films are considered in details. A special attention is paid to the fluctuations of the gauge field. It is shown that the mechanism in which these gauge fluctuations affect on the order of the phase transition and other phase transition properties varies with the variation of the spatial dimensionality D. The problem for the experimental confirmation of the theoretical predictions about the order of the phase transitions in gauge systems is discussed.

British Library Electronic Table of Contents (United Kingdom)

A suite of numerical experiments is conducted to extend our previous studies to explore the effects of linear, ambient wind shear on simulated mammatus-like clouds. Increasing values of unidirectional shear result in banded cloud bases, and for the strongest shears roll-type quasi-two-dimensional convection results rather than three-dimensional lobe morphology. Two observed soundings were used, and the sounding with a drier, shallower sub-cloud layer appeared to be most strongly affected by the presence of the ambient shear. The drier sounding also had less snow in the mammatus lobes owing to sublimation. Copyright Copyright 2009 Royal Meteorological Society

Energy Technology Data Exchange (ETDEWEB)

The code is being developed starting from the steady-state finite element code FENDER for the solution of the diffusion equation by extending it to become time-dependent. The numerical solution of the time-dependent multigroup diffusion equations within TRANSFUSION is performed at the present stage of development by using a backward difference scheme for the time variable, leading to a rearrangement of FENDER by adding a new loop over time steps. The code retains the multigroup coupled neutron-gamma features of FENDER, and provides a consistent two-, and quasi three-dimensional numerical solution of both static and time-dependent multigroup diffusion equations. (orig./DG)

International Nuclear Information System (INIS)

The paper describes novel analytical methods developed for the detection of previous neutron irradiation and reprocessing of illicit nuclear materials, which is an important characteristic of nuclear materials of unknown origin in nuclear forensics. Alpha spectrometry and inductively coupled plasma sector-field mass spectrometry (ICP-SFMS) using solution nebulization and direct, quasi-non-destructive laser ablation as sample introduction were applied for the measurement of trace-level "2"3"2U, "2"3"6U and plutonium isotopes deriving from previous neutron irradiation of uranium-containing nuclear materials. The measured radionuclides and isotope ratios give important information on the raw material used for fuel production and enable confirm the supposed provenance of illicit nuclear material.

CERN Document Server

One of the major challenges facing the proposed high-energy linear e^+e^ colliders is the preservation of the extremely small vertical emittance from the damping rings to the interaction point (IP). This emittance must be transported through bunch compression sections, the main linac and finally through the beam delivery system to the IP. Historically, the beam dynamics issues of each subsystem have been studied quasi-independently, with the beam conditions and tolerances being specified at the boundaries. As part of the recent International Linear Collider Technical Review Committee, new simulation tools have been developed to simulate the beam transport through the integrated system, including static and dynamic errors, stabilization systems, and tuning algorithms.

British Library Electronic Table of Contents (United Kingdom)

This study performs a dynamic analysis of the rub-impact rotor supported by two couple stress fluid film journal bearings. The strong nonlinear couple stress fluid film force, nonlinear rub-impact force and nonlinear suspension (hard spring) are presented and coupled together in this study. The displacements in the horizontal and vertical directions are considered for various non-dimensional speed ratios. The numerical results show that the dynamic behaviors of the system vary with the dimensionless speed ratios, the dimensionless unbalance parameters and the dimensionless parameter, l*. Inclusive of the periodic, sub-harmonic, quasi-periodic and chaotic motions are found in this analysis. The results of this study contribute to a further understanding of the nonlinear dynamics of a rotor-...

International Nuclear Information System (INIS)

We develop a continuum description for the axial segregation of granular materials in a long rotating drum based on the dynamics of the thin near-surface granular flow coupled to bulk flow. The equations of motion are reduced to the one-dimensional system for two local variables only, the concentration difference and the dynamic angle of repose, or the average slope of the free surface. The parameters of the system are established from comparison with experimental data. The resulting system describes both initial transient traveling wave dynamics and the formation of quasi-stationary bands of segregated materials. A long-term evolution proceeds through slow logarithmic coarsening of the band structure which is analogous to the spinoidal decomposition described by the Cahn-Hilliard equation. copyright 1999 The American Physical Society

British Library Electronic Table of Contents (United Kingdom)

Experimental results of quasi-static and dynamic fracture of particle-filled polymer composite (PFPCM) "ALTUGLAS EI CH25" with a matrix of polymethylmethacrylate (PMMA) are reported in this paper. PMMA matrix is filled with rubber particles, as result a shock-resistant transparent composite is produced. The main task was to investigate experimentally and theoretically the fracture toughness of this composite under static and dynamic loading. A high-rate loading has been created by impulse magnetic field. Analysis of fracture process and its relation with the load parameters and material microstructure have been established. Application of the original testing method enabled determination of fracture toughness at very short loading times and comparison of the results with material dynamic p...

Energy Technology Data Exchange (ETDEWEB)

Using a quasi-static approach valid for Stefan numbers less than one, we derive approximate equations governing the movement of a phase change front for materials which generate internal heat. These models are applied for both constant surface temperature and constant surface heat flux boundary conditions, in cylindrical, spherical, plane wall and semi-infinite geometries. Exact solutions with the constant surface temperature condition are obtained for the steady-state solidification thickness using the cylinder, sphere, and plane wall geometries which show that the thickness depends on the inverse square root of the internal heat generation. Under constant surface heat flux conditions, closed form equations can be obtained for the three geometries. In the case of the semi-infinite wall, we show that for constant temperature and constant heat flux out of the wall conditions, the solidification layer grows then remelts. (orig.)

CERN Document Server

Mono-layers of stearic and behenic acids and mixtures of them in different proportions, deposited with the Langmuir-Blodgett technique, were used to study the alignment and the alignment dynamics in nematic liquid crystal cells. A relaxation process from a splay-bend flow induced metastable orientation to the homeotropic one occurs. The lifetime of the metastable state was found to depend on the mono-layer composition. The transition between the homeotropic and the conical anchoring was found to be irreversible in the case of the mixed aligning mono-layers: on cooling from the isotropic phase a quasi-planar nematic state (schlieren texture) appears. It is stable in a range of a few degrees below the clearing point and, on decreasing the temperature, relaxes to the homeotropic state in form of expanding domains.

CERN Document Server

Event generators that handle neutrino-nucleon interaction have been developed for the FLUKA code [1]. In earlier FLUKA versions only quasi-elastic (QEL) interactions were included, and the code relied on external event generators for the resonance (RES) and deep inelastic scattering (DIS). The new DIS+RES event generator is fully integrated in FLUKA and uses the same hadronization routines as those used for simulating hadron-nucleon interactions. Nuclear effects in neutrino-nucleus interactions are simulated within the same framework as in the FLUKA hadron-nucleus interaction model (PEANUT), thus profiting from its detailed physics modelling and longstanding benchmarking. The generators are available in the standard FLUKA distribution. They are presently under development and several improvements are planned to be implemented. The physics relevant to the neutrino-nucleon interactions and the results of comparisons with experimental data are discussed.

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 ...

KoreaScience (Korea)

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Wastenet

operating at the maximal setting of speed control dials used to control their ...evaluates their energy performance when the speed control dial used ...FFUs when the speed control dial used for adjusting fan wheel speeds in each FFU was

CERN Document Server

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Science.gov (United States)

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Science.gov (United States)

Detailed three dimensional wing kinematics and aerodynamic characteristics are experimentally presented for the free flight of a beetle, Allomyrina dichotoma, which has a pair of elytra (fore wings) and hind wings. The kinematic parameters of the wing motion, such as the wing tip trajectory, angle of attack, torsion angle, and camber deformation, are obtained from a 3D reconstruction technique that involves the use of two or three synchronized high-speed cameras to digitize various points marked on the wings. Our data show outstanding characteristics of wing deformation and flexibility in the free flight of the beetle. To find out the mechanism of aerodynamic force, the leading edge vortex (LEV) and trailing edge vortex (TEV) on both elytron and hind wing were observed by using smoke wire visualization and digital particle image velocimetry (DPIV) technique. Qualitative smoke lines in the region of the most intent vortex shedding demonstrate clearly the interaction ...

Energy Technology Data Exchange (ETDEWEB)

Pellet injectors are needed to fuel long pulse tokamak plasmas and other magnetic confinement devices. For this purpose, an apparatus has been developed that forms 1.3-mm-diam pellets of frozen deuterium at a rate of 40 pellets per second and accelerates them to a speed of 1 km/s. Pellets are formed by extruding a billet of solidified deuterium through a 1.3-mm-diam nozzle at a speed of 5 cm/s. The extruding deuterium is chopped with a razor knife, forming 1.3-mm right circular cylinders of solid deuterium. The pellets are accelerated by synchronously injecting them into a high speed rotating arbor containing a guide track, which carries them from a point near the center of rotation to the periphery. The pellets leave the wheel after 150/sup 0/ of rotation at double the tip speed. The centrifuge is formed in the shape of a centrifugal catenary and is constructed of high strength KEVLAR/epoxy composite. This arbon has been spin-tested to a tip speed of 1 km/s.

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 proposed method gave unidirectional lasing with an intensity ratio in the two directions of at least 600:1, the intensity of ...

Energy Technology Data Exchange (ETDEWEB)

The U.S. Department of Energy Environmental Management's (DOE-EM) investments in science and technology, as well as science and technology investments associated with other parts of the DOE are aimed at meeting the Departments cleanup goals. These investments, primarily focused on EM's cleanup mission, comprise the Environmental Quality Research and Development (R&D) portfolios. Synchronizing EM's Cleanup Project Managers (operations facility and process owners throughout the DOE complex) operational needs with EM R&D including the extensive work of the six Focus Areas (major thrust areas within DOE-EM) has been a continuing challenge. This recent initiative to better integrate the R&D program is in response to evolving needs within the Department to apply proven system engineering methods to clarify requirements and define EM's process to effectively orchestrate their R&D Program. To optimize this partnership, ...

Energy Technology Data Exchange (ETDEWEB)

A Bragg waveguide consisting of multiple dielectric layers with alternating index of refraction becomes an excellent option to form electron accelerating structure powered by high power laser sources. It provides confinement of a synchronous speed-of-light mode with extremely low loss. However, laser field can not be coupled into the structure collinearly with the electron beam. There are three requirements in designing input coupler for a Bragg electron accelerator: side-coupling, selective mode excitation, and high coupling efficiency. We present a side coupling scheme using a distributed grating-assisted coupler to inject the laser power into the waveguide. Side coupling is achieved by a grating with a period on the order of an optical wavelength. The phase matching condition results in resonance coupling thus providing selective mode excitation capability. The coupling efficiency is limited by profile matching between the outgoing beam and the incoming beam, ...

Energy Technology Data Exchange (ETDEWEB)

Recently, a drive laser for an S-band (2.86 GHz) rf photoinjector, designed to provide a pulse that has a flat temporal and spatial profile, has been built, commissioned, and put into service as part of the LLNL Compton-scattering monoenergetic {gamma}-ray source program. This laser is based on an all-fiber oscillator and front-end amplification system, and provides both the laser light to generate the electrons as well as the rf signal that is amplified to accelerate them. Now, a new 11.424 GHz photoinjector is being developed, which has required a revised design for the laser system. The higher frequency has placed more stringent requirements on the synchronization stability, delivered pulse length, and pulse rise times to maintain the desired emittance. Presented here are the overall design and measured performance of the current system and a discussion of what changes are being made to address observed shortcomings and more demanding requirements to make the ...

CERN Document Server

In the past ten years, significant research effort was invested in audio browsers, programs able to decode the structure of Web pages and put them into an audio format. Few advanced browsers use machine learning algorithms to classify objects on the Web page and learn browsing behaviors, have multimodal input and outputs and are able to synchronize between the graphical and audio modalities to interact with the Web page. The disadvantages of these audio browsers include the necessity of a high computation power since the user's machine has to decode the structure of the Web page, and, therefore, making impossible the installation of such programs on mobile devices. In this paper, we propose a simpler and more efficient solution for the creation of a multimodal application. We developed a middleware that automatically annotates Web pages with VoiceXML generated from the content of the Web page. Using our system, the user can interact with the Web page, by using ...

Science.gov (United States)

... 65th AGARD Fluid Dynamics Symposium, Madrid, Spain, October ... of research programs on flow control ... separation, and delta wing flows formed the ...

Energy Technology Data Exchange (ETDEWEB)

Small unilamellar vesicles which form when gel-state long-chain phosphatidylcholines are mixed with micellar short-chain lecithins undergo an increase in size as the long-chain species melts to its liquid-crystalline form. Analysis of the vesicle population with quasi-elastic light scattering shows that the particle size increases from 90-A radius to greater than 5000-A radius. Resonance energy transfer experiments show total mixing of lipid probes with unlabeled vesicles only when the Tm of the long-chain phosphatidylcholine is exceeded. This implies that the large size change represents a fusion process. Aqueous compartments are also mixed during this transition. 31P NMR analysis of the vesicle mixtures above the phase transition shows a great degree of heterogeneity with large unilamellar particles coexisting with oligo- and multilamellar structures. Upon cooling the vesicles below the Tm, the original size distribution (e.g., small unilamellar vesicles) is ...

International Nuclear Information System (INIS)

Neutron time-of flight spectra were measured from 90 MeV protons and 140 MeV alpha-particle bombardment of Al, Ni, Zr, and Bi at laboratory angles between 20"0 and 130"0. The proton induced neutron spectra reveal three distinct energy regions; a low energy evaporation region, a high-energy region dominated by quasi-free scattering processes and an intermediate-energy region dominated by multi-step, pre-equilibrium processes. In the latter two regions, the spectra show strong angular dependence. The alpha-induced neutron spectra show these same distinct energy regions plus an exponential fall-off above the beam energy per nucleon. The high-energy portions of the forward-angle neutron and proton cross sections are in ratios consistent with the assumption that single nucleon-nucleon scattering dominates. For heavy-mass targets, the low-energy evaporation regions show neutron yields larger than proton yields. The proton-to-neutron ratios observed in the high-energy ...

International Nuclear Information System (INIS)

The heavy water reactor such as Wolsung No.1 and No.2 has a purification system to purify the reactor coolant. The control system regulates the coolant temperature to protect the ion exchanger. After the fuel exchanges of operating plant, the increase of the coolant pressure makes the purification temperature control difficult. In this paper, the controllability of the control dynamics of the purification system was analysed and the optimal parameters were proposed. To reduce the effects of the flow disturbance, the feedforward control structure was proposed and analysed.

International Nuclear Information System (INIS)

In the case of large capacity steam turbines the conventional nozzle group control is, for mechanical and thermodynamic reasons, diminishing more and more in importance in favour of variable pressure control. A design for constant-pressure operation as an alternative to nozzle group control is described; this demonstrates a series of important advantages compared with the latter. (orig.).

Energy Technology Data Exchange (ETDEWEB)

The French office for technical studies and control of big dams (BETCGB), has recently reedited the `guidebook for the control of dams in exploitation`. The aim of this document is to provide to the regional directions of industry, research and environment (DRIRE) a methodological help for their control actions of hydroelectric dams granted for exploitation. It comprises 6 chapters dealing with: the different type of dams, the inspection, the surveillance, the floods evacuation, the flood instructions, and the particular emergency plans. (J.S.)

Energy Technology Data Exchange (ETDEWEB)

Fuji Electric has realized highly reliable and functional control systems by the dispersion type control system FOCUS, which uses the controller (ICS-2000) enjoying good reputation in controlling industrial plants for a long time and a personal computer with high windows operability, the former for controlling and the latter for MHI responsible for monitoring. The smelting process in a steel-making plant needs a highly reliable system for advanced control to ensure continuous operation. Fuji Electric delivered the FOCUS system to Kubota in 1998, as the smelting furnace instrumentation/control system for the cupola furnace. The system has been in service smoothly. Moreover, a total of four control systems have been delivered, 2 for steel-making furnaces and the other 2 for continuous casting. (NEDO)

International Nuclear Information System (INIS)

Purpose: To stably control the reactor water level so as not to cause excess water feeding in a BWR type reactor. Constitution: A flow control valve is disposed to the exit of a feedwater pump for a nuclear reactor and the valve is controlled by a flow regulator to maintain the water level constant in the reactor. A signal from a water level controller is inputted to the flow regulator to thereby control the flow rate control valve. In this case, the flow regulator remains in a saturated state just after the starting of the feedwater pump, in which the pump flowrate is at 100% to result in an excess water feeding condition. In view of the above, a feedback circuit is provided to the flow regulator so that the saturated state is eliminated and the water feeding can be controlled directly from the water level controller. ...

Energy Technology Data Exchange (ETDEWEB)

This paper deals with the control of an electromechanical valves engine. The control uses neural networks in order to build a non-linear model of engine filing which depends on the driven inlets. The aim is to build this real-time model and to integrate this model to a control system which performs an iterative inversion. (J.S.)

Energy Technology Data Exchange (ETDEWEB)

Experience and technical innovations in power plant engineering have resulted in continuous improvements of operation control, availability and safety of pumped storage plants. Process control is constantly improved as new developments are made in equipment and systems engineering. Plant control concepts with increasingly complex automation hierarchy are described by which pumped storage processes can be controlled optimally, reliably, and automatically.

Energy Technology Data Exchange (ETDEWEB)

The technology status of the dynamics and controls discipline as it applies to energy storage wheel systems was evaluated. No problems were identified for which an adequate solution could not be proposed. Design issues that influence control were addressed. The dynamics and control aspects associated with the energy storage system concept and its various constituent parts, and the control tasks attendant to large, manned spacecraft are discussed.

International Nuclear Information System (INIS)

Experiments on the depth dependence of transient enhanced diffusion (TED) of boron during rapid thermal annealing of Ge-preamorphized layers reveal a linear decrease in the diffusion enhancement between the end-of-range (EOR) defect band and the surface. This behavior, which indicates a quasi-steady-state distribution of excess interstitials, emitted from the EOR band and absorbed at the surface, is observed for annealing times as short as 1 s at 900 deg. C. Using an etching procedure we vary the distance x_E_O_R from the EOR band to the surface in the range 80-175 nm, and observe how this influences the interstitial supersaturation, s(x). The supersaturations at the EOR band and the surface remain unchanged, while the gradient ds/dx, and thus the flux to the surface, varies inversely with x_E_O_R. This confirms the validity of earlier modelling of EOR defect evolution in terms of Ostwald ripening, and provides conclusive evidence that the surface is the dominant ...

CERN Document Server

The matter spectrum of the MSSM, including three right-handed neutrino supermultiplets and one pair of Higgs-Higgs conjugate superfields, can be obtained by compactifying the E_{8} x E_{8} heterotic string and M-theory on Calabi-Yau manifolds with specific SU(4) vector bundles. These theories have the standard model gauge group augmented by an additional gauged U(1)_{B-L}. Their minimal content requires that the B-L gauge symmetry be spontaneously broken by a vacuum expectation value of at least one right-handed sneutrino. In previous papers, we presented the results of a quasi-analytic renormalization group analysis showing that B-L gauge symmetry is indeed radiatively broken with an appropriate B-L/electroweak hierarchy. In this paper, we extend these results by 1) enlarging the initial parameter space and 2) explicitly calculating all renormalization group equations numerically, without approximation. The regions of the initial parameter space leading to ...

Energy Technology Data Exchange (ETDEWEB)

The objective of the Coastal Habitat Injury Assessment study was to document and quantify injury to biota of the shallow subtidal, intertidal, and supratidal zones throughout the shoreline affected by oil or cleanup activity associated with the Exxon Valdez oil spill. The results of these studies were to be used to support the Trustee`s Type B Natural Resource Damage Assessment under the Comprehensive Environmental Response, Compensation, and Liability Act of 1980 (CERCLA). A probability based stratified random sample of shoreline segments was selected with probability proportional to size from each of 15 strata (5 habitat types crossed with 3 levels of potential oil impact) based on those data available in July, 1989. Three study regions were used: Prince William Sound, Cook Inlet/Kenai Peninsula, and Kodiak/Alaska Peninsula. A Geographic Information System was utilized to combine oiling and habitat data and to select the probability sample of study sites. ...

International Nuclear Information System (INIS)

The neutron capture cross sections of Sr-88 and Y-89 were measured in a quasi-stellar neutron spectrum for kT = 25 keV via the activation method. Relevant systematic uncertainties were determined experimentally by repeated activations under different conditions and with different samples. Gold was used as a cross section standard. The resulting stellar cross sections for kT = 30 keV are 6.13 + or - 0.18 mbarn for Sr-88 and 19.0 + or - 0.6 mbarn for Y-89. The partial cross section Sr-86(n, gamma) Sr-87m was measured to 48.1 + or - 1.2 mbarn. Compared to previous data, the associated uncertainties are reduced by factors of 3 and 5, respectively. The implications for s-process nucleosynthesis around magic neutron number N = 50 are discussed in the light of new information on neutron density and temperature. 38 refs.

British Library Electronic Table of Contents (United Kingdom)

Abstract A next generation material for surface passivation of crystalline Si is Al2O3. It has been shown that both thermal and plasma-assisted (PA) atomic layer deposition (ALD) Al2O3 provide an adequate level of surface passivation for both p- and n-type Si substrates. However, conventional time-resolved ALD is limited by its low deposition rate. Therefore, an experimental high-deposition-rate prototype ALD reactor based on the spatially separated ALD principle has been developed and Al2O3 deposition rates up to 1.2-nm/s have been demonstrated. In this work, the passivation quality and uniformity of the experimental spatially separated ALD Al2O3 films are evaluated and compared to conventional temporal ALD Al2O3, by use of quasi-steady-state photo-conductance (QSSPC) and carrier density ...

CERN Document Server

We study the phenomenology of a new Minimally-extended Supersymmetric Standard Model (newMSSM) where a gauge singlet superfield is added to the MSSM spectrum. The superpotential of this model contains no dimensionful parameters, thus solving the mu-problem of the MSSM. A global discrete R-symmetry, forbidding the cubic singlet self-interaction, imposed on the complete theory, guarantees its stability with respect to generated higher-order tadpoles of the singlet and solves both the domain wall and Peccei-Quinn axion problems. We give the free parameters of the model and display some general constraints on them. A particular attention is devoted to the neutralino sector where a (quasi-pure) singlino appears to be always the LSP of the model, leading to additional cascades, involving the NLSP -> LSP transition, compared with the MSSM. We then present the upper bounds on the masses of the lightest and next-to-lightest -- when the lightest is an invisible singlet -- ...

International Nuclear Information System (INIS)

In vacuum arcs of interest for ion deposition, in which a magnetic filter is used, significant plasma rotation about the filter axis can develop. In the present work we present experimental evidence and simplified models to interpret relatively fast rotation of plasma generated in a pulsed vacuum arc with a straight magnetic filter and with a magnetic field strength in the range 52-430 G. The plasma rotation is produced in the first part of the filter (the driving region) where either the expanding or the contracting plasma encounters a mainly axial magnetic field. In the next part of the filter (the rotation region) a quasi-equilibrium is achieved and the plasma does not evolve further significantly. A rigid-rotor type of equilibrium is considered to model the rotation region, with experimentally obtained parameters, and a simple model is employed in the driving region to quantify the magnitude of the plasma rotation. It is found that at the quoted values of the ...

International Nuclear Information System (INIS)

We report the results of the DC magnetization, neutron powder diffraction and neutron depolarization studies on the spin-chain compounds Ca3Co2-xFexO6 (x = 0, 0.1, 0.2 and 0.4). Rietveld refinement of neutron powder diffraction patterns at room temperature confirms the single-phase formation for all the compounds in rhombohedral structure with space group R3-barc. Rietveld refinement also confirms that Fe was doped at the trigonal prism site, 6a (0, 0, 1/4) of Co. The high temperature magnetic susceptibility obeys the Curie-Weiss law; the value of the paramagnetic Curie temperature (?p) decreases as the concentration of iron increases and it becomes negative for x = 0.4. No extra Bragg peak as well as no observable enhancement in the intensity of the fundamental (nuclear) Bragg peaks has been observed in the neutron diffraction patterns down to 30 K. No depolarization of neutron beam has been observed down to 3 K confirming the absence of ferro- or ferrimagnetic-like correlation. ...

International Nuclear Information System (INIS)

We consider a Bose-Einstein condensate (BEC) of N atoms of repulsive interaction #approx# U_0, in an elliptical trap, axially pierced by a Gaussian-intensity laser beam, forming an effective (quasi-2D) toroidal trap with minimum at radial distance #rho# = #rho#_p. The macroscopic angular momentum states #PSI#_l(#rho#,#theta#) #approx# #sq root#N#PHI#_l(#rho#)e"i"l"#theta# for integer l spread up to #rho# > #rho#_p. The spreading lowers rotational energies, so estimated low metastability barriers can support large l < or approx. l_m_a_x #approx# (NU_0)"1"/"4, < or approx. 10 for typical parameters. The l-dependent density profile module #PHI#_l(#rho#)"2 -#PHI#_0(#rho#)"2 is a signature of BEC rotation. Results are insensitive to off-axis laser displacements #rho#_0, for #rho#_0 #rho#_m_a_x << 1. (author).

International Nuclear Information System (INIS)

Measurements have been made on the magnetic susceptibilities of the quasi-one-dimensional magnetic #approx#-UF_5 and the cluster magnetic U_2F_9 (a four-nuclear type) over the range 4.2-300 K. The Curie-Weiss law applies for #approx#-UF_5 above 200 K, with #mu#ef = 2.37#mu#B, theta = -148 K; that law also applies to U_2F_9 above 150 K, with #mu#ef = 2.9#mu#B and theta = 118 K. The antiferromagnetic ordering is discussed for the one-dimensional chains in #approx#-UF_5 together with the phase transition observed in U_2F_9 at 6 K. It is assumed that the U"4"+ and U"5"+ valency states are stabilized below the phase-transition point, and only then can U_2F_9 be considered as the compound UF_4 x UF_5.

International Nuclear Information System (INIS)

The question concerning the existence of an electronic topological transition (ETT) in Zn metal under quasi-hydrostatic pressure at #approx#6.6 GPa caused a considerable controversy in the literature. We briefly review low-temperature "6"7Zn-Moessbauer data and scalar-relativistic augmented plane wave calculations and give a consistent interpretation in terms of an ETT. To highlight some important aspects of the controversy two theoretical and two experimental publications will be discussed in more detail. At present the existence of an ETT in Zn metal is disputed both from an experimental and from a theoretical point of view. The suggestion of a transition to a commensurate spin-density wave at #approx#6.6 GPa instead of an ETT may reconcile the seemingly contradictory results of "6"7Zn-Moessbauer experiments at 4.2 K and of room temperature inelastic neutron scattering measurements. However, it does not explain the anomalies found in theoretical calculations ...

CERN Document Server

We show how to obtain a fast component-by-component construction algorithm for higher order polynomial lattice rules. Such rules are useful for multivariate quadrature of high-dimensional smooth functions over the unit cube as they achieve the near optimal order of convergence. The main problem addressed in this paper is to find an efficient way of computing the worst-case error. A general algorithm is presented and explicit expressions for base~2 are given. To obtain an efficient component-by-component construction algorithm we exploit the structure of the underlying cyclic group. We compare our new higher order multivariate quadrature rules to existing quadrature rules based on higher order digital nets by computing their worst-case error. These numerical results show that the higher order polynomial lattice rules improve upon the known constructions of quasi-Monte Carlo rules based on higher order digital nets.

International Nuclear Information System (INIS)

In this paper, we study the effect of the Ge"+ preamorphization dose on boron diffusion and on the thermal evolution of end of range (EOR) defects during annealing. Amorphizations were carried out by implanting Ge"+ at 150 keV to doses ranging from 1x10"1"5 to 8x10"1"5 ions/cm"2. Boron was subsequently implanted at 3 keV with a dose of 1x10"1"4 ions/cm"2. Rapid thermal annealing (RTA) was performed for various time/temperature combinations in nitrogen ambient. Secondary ion mass spectroscopy (SIMS) and transmission electron microscopy (TEM) were used to study boron diffusion and defect evolution, respectively. We have found that after a given annealing, both the defect size and boron diffusivity are independent on the Ge ion dose. Increasing this dose only results in an increase of the defect density. These results are discussed and definitely show that EOR defects are involved in a quasi-conservative Ostwald ripening process during annealing. The diffusive ...

Energy Technology Data Exchange (ETDEWEB)

The corrosion behavior of 304 stainless steel was characterized with cyclic voltammetry in a eutectic Li/K and Li/Na carbonate melt under anode and cathode gas of the molten-carbonate fuel cell (MCFC). The corrosion rate of 304 steel was determined in four different environments of the MCFC with electrochemical methods and from cross-sectional analysis of corrosion layers. These four environments were open-circuit and MCFC-load conditions both under anode and cathode gas. At open-circuit conditions corrosion was more severe under the oxidizing cathode gas then under the reducing anode gas. On the contrary, at load conditions corrosion was more severe under anode than under cathode gas. The anodic polarization under anode gas enhances corrosion, whereas the high anodic polarization under cathode gas leads to anodic protection. Corrosion currents were measured with chronoamperometry and determined with Tafel extrapolation from quasi-stationary polarization-curve ...

Energy Technology Data Exchange (ETDEWEB)

We are continuing to study the suitability of modified thermal-battery technology as a potential power source for geothermal borehole applications. Previous work focused on the LiSi/FeS{sub 2} couple over a temperature range of 350 C to 400 C with the LiBr-KBr-LiF eutectic, which melts at 324.5 C. In this work, the discharge processes that take place in LiSi/CsBr-LiBr-KBr eutectic/FeS{sub 2} thermal cells were studied at temperatures between 250 C and 400 C using pelletized cells with immobilized electrolyte. The CsBr-LiBr-KBr eutectic was selected because of its lower melting point (228.5 C). Incorporation of a quasi-reference electrode allowed the determination of the relative contribution of each electrode to the overall cell polarization. The results of single-cell tests and limited battery tests are presented, along with preliminary data for battery stacks tested in a simulated geothermal borehole environment.

British Library Electronic Table of Contents (United Kingdom)

Abstract Coordination compounds [Ru(acac)2(Q)] (acac=acetylacetonate; Q=o-benzoquinone) were prepared as complexes 1 (Q=o-benzoquinone), 2 (Q=3-methoxy-o-benzoquinone), 3 (Q=4-methyl-o-benzoquinone), and 4 (Q=3,5-di-tert-butyl-o-benzoquinone). The structures of 1 and 2 were determined to reveal a RuIII/o-benzosemiquinone formulation, supported by analysis of experimental data (spectroscopy, magnetism of 1) and by DFT calculations. The S=1 ground state calculated for 1 stands in contrast to the spin-paired analogues with arylimino-o-benzosemiquinonato and diimino-o-benzoquinone ligands. The close contacts of about 5.3- possible between semiquinone O atoms of different molecules in the crystal allow for intermolecular spin-spin interactions and an overall complex magnetic behavior. One quasi...

Energy Technology Data Exchange (ETDEWEB)

Debris coolability in the lower plenum of the reactor pressure vessel is an important factor for evaluation of debris in-vessel retention. The debris coolability analysis module is developed for the accurate prediction of the safety margin of the present reactor vessels in a severe accident. The module calculates debris spreading and cooling through melting and solidification in combination with a temperature distribution and failure evaluation of the vessel wall. Debris spreading is solved by the explicit method on a quasi-three-dimensional scheme and debris coolability is solved on the basis of natural convection analysis. The calculation for spreading is compared with a water spreading experiment on the floor and the calculation for coolability is compared with a n-octadecane melting experiment in a rectangular vessel. The comparisons show capabilities for predictions of spearhead transportation in the debris spreading process and of melting front transportation ...

CERN Document Server

We construct analytic models of incompressible, rigidly rotating stars in PN gravity and study their stability against nonaxisymmetric Jacobi-like bar modes. PN configurations are modeled by homogeneous triaxial ellipsoids and the metric is obtained as a solution of Einstein's equations in 3+1 ADM form. We use an approximate subset of the equations well-suited to numerical integration for strong field, 3D configurations in quasi--equilibrium. These equations are exact at PN order, and admit an analytic solution for homogeneous ellipsoids. In this paper we present this solution, as well as analytic functionals for the conserved global quantities, M, M_0 and J. By using a variational principle we construct sequences of axisymmetric equilibria of constant density and rest mass, i.e. the PN generalization of Maclaurin spheroids, which are compared to other PN and full relativistic sequences presented by previous authors. We then consider nonaxisymmetric ellipsoidal ...

Energy Technology Data Exchange (ETDEWEB)

Much of the current technology on 3D-prestack depth migration is based on the Kirchhoff method and the traveltime information needed for this purpose is obtained by the ray-theory approximation. The main motivation driving these options is to reduce computations but it can also have an adverse effect on the quality of results. Experience with real data indicates that the corresponding poststack data migrated by the reverse-time method often yields superior results. Considerable computational efficiency can be obtained by employing nonuniform coarse grid spacing during the reverse-time migration. We followed this strategy for developing a parallel scheme for doing 3D- prestack depth migration. However, we worked only on a small subset of shot gathers whose determined by the Quasi-Monte Carlo method. The results were indistinguishable from those obtained by using a much larger population of uniformly spaced shot gathers. We present examples of migration of 3-D data. ...

CERN Document Server

The evolution of FRI jets has been long studied in the framework of the FRI-FRII dichotomy. In this paper, we test the present theoretical and observational models via a relativistic numerical simulation of the jets in the radio galaxy 3C 31. We use the parameters derived from the modelling presented by \\cite{lb02a,lb02b} as input parameters for the simulation of the evolution of the source, thus assuming that they have not varied over the lifetime of the source. We simulate about 10 % of the total lifetime of the jets in 3C 31. Realistic density and pressure gradients for the atmosphere are used. The simulation includes an equation of state for a two-component relativistic gas that allows a separate treatment of leptonic and baryonic matter. We compare our results with the modelling of the observational data of the source. Our results show that the bow shock evolves self-similarly at a quasi-constant speed, with slight deceleration by the end of the simulation, ...

International Nuclear Information System (INIS)

These experiments were performed on the Isocele separator, on-line with the Orsay synchrocyclotron; thulium isotopes were produced by bombarding natural erbium targets with 150nA beam of 157MeV protons. Two Ge(Li) detectors, with resolution of 2.3 and 2.5keV at 1332keV used for #gamma#-ray measurements; conversion electron spectra were measured using a Si(Li) detector. #gamma# spectra, #gamma#-#gamma# coincidence and conversion electron measurements were sufficient to build the flow energy level schemes of the transitional "1"5"8Er and "1"5"6Er nuclei. On both nuclei several quasi rotational bands have been identified. These results are compared with other even erbium isotopes and with the neighboring N=88 and 90 isotones. Comparisons with predictions issued from some classical models are also performed: "1"5"8Er appears as a deformed nucleus very similar to "1"6"0Er and "1"6"2Er; on the other hand "1"5"6Er seems to be a soft vibrational nucleus.

Energy Technology Data Exchange (ETDEWEB)

This article reviews briefly a range of the latest monitoring and controlling equipment for use in coal mines. This includes pressure transmitters, shale/coal discriminator, nucleonic bunker level indicator, automatic steering and monitoring system, oscilloscope/multimeter, and microprocessor based digital display controllers. 1 fig.

Science.gov (United States)

The highly variable and intermittent pollutant concentrations and flowrates associated with wet-weather events in combined sewersheds necessitates the use of storage-treatment systems to control pollution.An optimized combined-sewer-overflow (CSO) control system requires a manage...

Energy Technology Data Exchange (ETDEWEB)

This work considers the problem of controlling multiple nonholonomic vehicles so that they converge to a scent source without colliding with each other. Since the control is to be implemented on simple 8-bit microcontrollers, fuzzy control rules are used to simplify a linear quadratic regulator control design. The inputs to the fuzzy controllers for each vehicle are the (noisy) direction to the source, the distance to the closest neighbor vehicle, and the direction to the closest vehicle. These directions are discretized into four values: Forward, Behind, Left, and Right, and the distance into three values: Near, Far, Gone. The values of the control at these discrete values are obtained based on the collision-avoidance repulsive forces and the change of variables that reduces the motion control problem of each nonholonomic vehicle to a ...

Science.gov (United States)

The objective of this project is to reduce energy consumption in 203 buildings by providing a new EMCS (Energy Monitoring Control System) to control and monitor systems.

UK PubMed Central (United Kingdom)

A retrospective case-control study tested the hypothesis that exposure to hydrocarbon combustion products is associated with the development of renal cell carcinoma. One control per case, matched for...Full Text Available

Energy Technology Data Exchange (ETDEWEB)

This paper has the objective of presenting the philosophy of Static Var Compensator (SVC) Control as well the necessary adjustments in the project of control system to guarantee suitable performance under different operating conditions. The verification on the performance of the SVC control has been done by Transient Network Analyzer (TNA/CEPEL) studies, commissioning tests and a factory tests. The SVC is the type of Thyristor Controlled Reactor (TCR) and Thyristor Switched Capacitor (TSC). (author) 3 refs., 12 figs.

Energy Technology Data Exchange (ETDEWEB)

A dual fuel engine control system for controlling the power output of a dual fuel compression ignition engine. The engine includes mixing means for combining an oxidizer and a primary fuel at a substantially constant ratio of oxidizer to primary fuel. The power output of the engine is controlled through the use of a throttle valve controlling the quantity of combustible mixture delivered to the combustion chamber. The fuel control system minimizes the quantity of ignition fuel required by controlling the quantity of combustible mixture rather than the fuel of air ratio. (author) figs.

International Nuclear Information System (INIS)

The control valve for a large steam turbine must be operated linearly to be run by an automatic control system in a power plant. It is, however, found that the flow increase is much greater for a given valve position change near the closed end of travel than it is near the open end. Accordingly, the desired linearization will be achieved if the valve is opened less near the closed end of travel and greater near the open end. The previous way for linearization was to utilize the cams, which is called the mechanical hydraulic control (MHC). The MHC was afterward improved by producing the nonlinear electric compensation to the nonlinear system of control valves, viz. the electro hydraulic control (EHC)

Energy Technology Data Exchange (ETDEWEB)

Short communication.