UK PubMed Central (United Kingdom)

Thermodynamic parameters for prediction of RNA duplex stability are reported. One parameter for duplex initiation and 10 parameters for helix propagation are derived from enthalpy and free-energy changes...Full Text Available

UK PubMed Central (United Kingdom)

The sequence information available for homeodomains reveals that salt bridges connecting pairs 19/30, 31/42, and 17/52 are frequent, whereas aliphatic residues at these sites are rare and mainly restricted...Full Text Available

KoreaScience (Korea)

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International Nuclear Information System (INIS)

17-4PH stainless steel was modified by direct current (DC) plasma nitriding and titanium nitride film duplex treatment in this study. The microstructure, wear resistance and corrosion resistance were characterized by X-ray diffraction (XRD), pin-on-disk tribological test and polarization experiment. The results revealed that the DC plasma nitriding pretreatment was in favor of improving properties of titanium nitride film. The corrosion resistance and wear resistance of duplex treatment specimen was more superior to that of only coated titanium nitride film.

Science.gov (United States)

Adenine DNA glycosylase catalyzes the glycolytic removal of adenine from the promutagenic A {center_dot} oxoG base pair in DNA. The general features of DNA recognition by an adenine DNA glycosylase, Bacillus stearothermophilus MutY, have previously been revealed via the X-ray structure of a catalytically inactive mutant protein bound to an A:oxoG-containing DNA duplex. Although the structure revealed the substrate adenine to be, as expected, extruded from the DNA helix and inserted into an extrahelical active site pocket on the enzyme, the substrate adenine engaged in no direct contacts with active site residues. This feature was paradoxical, because other glycosylases have been observed to engage their substrates primarily through direct contacts. The lack of direct contacts in the case of MutY suggested that either MutY uses a distinctive logic for substrate recognition or that the X-ray structure had captured a noncatalytically competent ...

Energy Technology Data Exchange (ETDEWEB)

The paper describes a concept of extracting fusion power from D-{sup 3}He fueled IEC (Inertia Electrostatic Configuration) devices. The fusion system consists of a series of fusion modules and direct energy converters at an end or at both ends. This system of multiple units is linear and is connected by a magnetic field. A pair of coils anti-parallel to the magnetic field yields a field-null domain at the center of each unit as required for IEC operation. A stabilizing coil installed between the coil pairs eliminates the strong attractive force between the anti-parallel coils. Accessible regions for charged particle trajectories are essentially isolated from the coil structure. Thus, charged particles are directed along magnetic field lines to the direct energy converter without appreciable losses. A direct energy converter unit designed to be compatible to this unique system is also described. It basically consists of a ...

Energy Technology Data Exchange (ETDEWEB)

Iron nickel chromium manganese silicon and iron chromium nickel manganese silicon molybdenum niobium alloys have a so-called duplex structure in a wide concentration range. This causes an excellent resistance to wear superior in the case of adhesive stress with optimized concentrations of manganese, silicon, molybdenum and niobium. The materials can be used for welded armouring structures wherever cobalt and boron-containing alloy systems are not permissible, e.g. in nuclear science. Within the framework of pre-investigations for manufacturing of filling wire electrodes, cast test pieces were set up with duplex structure, and their wear behavior was examined. (orig.).

Science.gov (United States)

... SDIVOP]2.0.CO;2 Sexual Differences in Vigilance of Paired Ruddy Shelduck in WinterRui-Chang Quan, ... pairs of the Ruddy Sheldu...

International Nuclear Information System (INIS)

First-principles density functional theory (DFT) based calculations were performed to study the electronic and cohesive properties of all the intermediate ordered phases appearing in the transformation from bcc-based #beta# to hexagonal ordered #omega# phase in Zr_3Al alloy. Full-potential linear augmented plane wave (FPLAPW) method under the GGA was employed to establish the stability hierarchy and structure-property correlations. Further, effective pair potentials upto the fourth nearest neighbours were extracted, which, subsequently, were used for the thermodynamics analysis of the thermally-induced #beta##->##omega# transformation. The lattice collapse mechanism involving the concept of the onset of a displacement wave where the extent of collapse is viewed as an amplification of the displacement wave was employed for further analysis. (author)

Energy Technology Data Exchange (ETDEWEB)

Duplex-coating procedures consisting of plasma nitriding and Me-C:H hard coating lead to an improved performance of the devices because the Me-C:H coating is supported by the nitrided phase and, therefore, the `eggshell-effect` is avoided. Furthermore, this support leads to a higher load-bearing capacity of the thin film. Two standard procedures (classical high-pressure plasma nitriding and unbalanced magnetron sputtering of Ti-C:H) were performed subsequently to prepare the duplex coatings on X20Cr13 ferritic stainless steel. The corrosion resistance of the steel could be improved by nitriding at 450 C compared to the untreated ferritic substrate. The roughness is determined by the nitriding step. The weakest point of the coating is the transition zone between the nitrided and the untreated substrate and not the interface between the Ti-C:H coating and the nitrided substrate as shown by the Rockwell and scratch tests. The adhesion of the ...

International Nuclear Information System (INIS)

Because of their austenitic-ferritic microstructures, duplex stainless steels offer a good combination of mechanical and corrosion resistance properties. However, heat treatments can lower the mechanical strength of these stainless steels as well as render them susceptible to intergranular corrosion (IGC) and pitting corrosion. In this study, a low-carbon (0.02%) duplex stainless steel is subjected to various heat treatments at 450 to 950 C for 30 min to 10 h. The heat-treated samples than undergo ASTM IGC and pitting corrosion tests, and the results are correlated with the microstructures obtained after each heat treatment. In the absence of Cr_2_3C_6 precipitation, #sigma#-phase precipitates render this duplex stainless steel susceptible to IGC and pitting corrosion. Even submicroscopic #sigma#-phase precipitates are deleterious for IGC resistance. Longer-duration heat treatments (at 750 to 850 C) induce chromium ...

International Nuclear Information System (INIS)

Thermo-reactive diffusion chromizing followed by pulsed plasma nitriding were carried out on AISI 52100 and 8620 bearing steels. The chromized samples were pulse-plasma nitrided for 5 h at 500 deg. C in various N_2-H_2 gas mixtures. The coated steels were characterized using scanning electron microscopy, X-ray diffraction and microhardness testing. The unlubricated wear behaviors of only chromized and duplex treated steels were investigated in ball-on-disc system tests at room temperature. X-ray diffraction patterns of the duplex treated samples containing H_2 indicated the formation of dominant CrN and Cr_2N nitrides as well as the formation of Cr_3C_2 and Cr_7C_3 carbides. Gas mixtures in the plasma nitriding, which was performed after chromizing, have a significant influence on the wear rate of the duplex treated steels. The wear and friction tests showed that the lowest friction coefficient and wear rates were observed ...

British Library Electronic Table of Contents (United Kingdom)

The parmbsc0 force field was applied to study in detail the binding of netropsin, at a salt concentration of 0.28M Na^+, to the minor groove of an 8-mer (5'CCAATTGG)2 DNA duplex forming a netropsin.DNA complex which previously has been characterized by X-ray crystallography, albeit with the use of closely related DNA duplexes. The X-ray structure revealed that the terminal guanidinium and amidinium groups of netropsin interact with the extreme ends of the palindromic AATT sequence of the receptor DNA. The parmbsc0 parameters of B-DNA and AMBER v9 parameters of netropsin generated a stable 6ns molecular dynamics (MD) trajectory for a 1:1 class I binding motif of this complex. Trajectory analysis for the salt and hydration effects on the binding of netropsin to the 8-mer DNA duplex revealed ...

Energy Technology Data Exchange (ETDEWEB)

A duplex surface treatment technique based on calorizing and plasma nitriding was developed to improve the wear and oxidation resistance of H13 steel at high temperatures. The effects of the relative thickness of the calorized layer to the depth of plasma nitriding on the wear and oxidation properties at temperatures up to 900 C were investigated in this work. High-temperature wear tests were performed at 500 C with dry conditions in open air using a ball-on-disk type tribotest machine. Isothermal oxidation tests were performed at 900 C for up to 100 h under controlled atmosphere. The results indicated that the specimens with a calorized layer as an intermediate phase between the surface duplex layer and the base metal showed higher wear and oxidation resistance than the specimens with a nitrided layer alone. During exposure to elevated temperatures, the aluminum in the calorized layer diffused to the surface and formed an aluminum oxide layer. ...

International Nuclear Information System (INIS)

The effect of surface treatment on the characteristics of the passive film on a super duplex stainless steel is addressed. Auger Electron Spectroscopy (AES) has been used to provide in-depth chemical profile analyses of the passivation film. This study showed that the constitution of the film is largely dependent on the electrolytic conditions under which it is produced or to which it is submitted. The passive films formed by polarisation in an alkaline solution (boric-borate solution) consist of two regions, an inner region rich in chromium and an outer region rich in iron, whilst the films produced in acid solution only present the chromium - rich region. The film thickness is also greatly affected by the polarisation conditions. It can vary from ca. 8 monolayers to about 20 monolayers for cathodically and anodically polarised specimens respectively. The microstructure of weldmetal is also discussed. (author)

UK PubMed Central (United Kingdom)

The authors emphasize the importance of stability in biological standards and discuss the steps taken to ensure the stability of International Standards and the theoretical basis of the various stability...Full Text Available

Science.gov (United States)

Neutrino processes role in star evolution and onset of supernovae explosion

Energy Technology Data Exchange (ETDEWEB)

This paper presents the isothermal characteristics of methanol onto two specimens of activated carbons namely Maxsorb III and Tsurumi activated charcoal. Dubinin Raduskevich (D-R) equation is used to correlate the adsorption isotherms and to form the pressure-temperature-concentration diagram for both of the assorted pairs. Experimental results show that the maximum adsorption capacity of Maxsorb III/methanol pair is 1.76 times that of activated charcoal/methanol pair. Employing a time-independent mathematical model, the performance of adsorption cooling cycle using Maxsorb III/methanol and activated charcoal/methanol pairs has been studied and compared with that of three other types of carbon based adsorbent/methanol pairs. Theoretical calculations show the superiority of Maxsorb III/methanol pair for both of air-conditioning and ice-making applications. ...

International Nuclear Information System (INIS)

In the present paper, the chemical composition of passive films formed on both phases of two types of duplex stainless steels (UNS S31803 and UNS S32304) is determined at the micro-scale using Auger electron spectroscopy (AES). Samples were either mechanically polished (down to diamond pastes) or electrochemically etched in acidic solutions. The micro-electrochemical behavior of samples was then determined in sodium chloride media by means of the electrochemical micro-cell technique (capillary diameters of 30 ?m). The results obtained were analyzed considering the passive film chemical composition. Quantitative relationships between electrochemical parameters and the distribution of chromium and iron in the oxide layer were found. Due to differences in mechanical properties between ferrite and austenite, a heterogeneous stress distribution is generated in both phases. A method based on thermal-mechanical simulation was used to quantify surface stress gradients and ...

Science.gov (United States)

Overviews, publications, and new directions are presented for the following research topics: geminate charge pairs in hexane, dipoles in nonpolar and polar organic liquids, organic donor-acceptor interfaces, and charge-transfer states (phenanthrene/PMDA).

Energy Technology Data Exchange (ETDEWEB)

A pneumatic device is in the form of a U-shaped frame, on which a prong is attached by using two pairs of levers. It also has a hydraulic or pneumatic cyclinder, whose rod is connected to one of the pairs of levers. All connections are hinges.

Science.gov (United States)

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KoreaScience (Korea)

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International Nuclear Information System (INIS)

Evolution of the passive films formed on AISI 304L and duplex stainless steel SAF 2205 in NaOH 0.1 M was investigated using cyclic voltammetry, electrochemical impedance spectroscopy (EIS) and X-ray photoelectron spectroscopy (XPS). Special attention is paid to the effect of Mo in the generation of the films. Results point out to the stabilising effect of the molybdates on the surface of the film, enhancing the formation of a thin layer on the SAF 2205 with a higher Cr/Fe ratio.

Science.gov (United States)

Positron-electron pair creation near the threshold energy is extremely difficult to investigate by both experiments and theory. First test experiments were performed at the ILL to determine the cross sections for positron-electron pair creation near threshold using prompt {gamma}-rays from different targets after neutron capture and conventional radioactive sources. Pair creation was studied in a Ge detector, which simultaneously acted as sample and detector. First results are presented which show a significant deviation from theoretical values near threshold.

Science.gov (United States)

... the bound (5). For a network composed of a single source-terminal pair and ... Suboptimality bounds in stochastic control: A queueing example ...

Science.gov (United States)

This study examined the effect of sulfur-containing compounds on the storage stability of Jet A

Energy Technology Data Exchange (ETDEWEB)

Pairing correlations in multi-quasiparticle states in deformed nuclei are expected to be reduced because of blocking. New intrinsic states and their associated rotational bands have been identified allowing comparisons to be made as a function of seniority and between nuclei. The possible effects of the reduced pairing on the collective rotation, and its manifestation in terms of alignment, are discussed. 13 refs., 2 figs.

Science.gov (United States)

We report on the effect of potato maltodextrins with variable dextrose equivalent (Paselli SA-2, SA-6 and SA-10) on the surface behavior at the air-water interface of the mixture: legumin+small-molecule surfactant. Distinct in nature small-molecule surfactants (model: sodium salt of capric acid, Na-caprate; and commercially important: a citric acid ester of monoglyceride, CITREM) have been under our consideration. The role of the structure of both of the maltodextrins and the small-molecule surfactants in the effect studied has been elucidated by measurements in a bulk aqueous medium of the enthalpy of their interaction from mixing calorimetry, value of weight average molecular weight of the maltodextrins and the thermodynamics of the pair maltodextrin-solvent and maltodextrin-protein interactions from laser static light scattering. The combined data of mixing calorimetry and light scattering suggest some complex formation between the small-molecule surfactants and ...

International Nuclear Information System (INIS)

Developed under the PN II Project 71-009 - MONA, the pre-operational monitoring program of the LIL waste disposal site presented in this paper covers the main elements requested for a continuous improvement of site characterization and safety assessment, as well as for the set up of the baseline data requested for the future operational and post-operational monitoring and surveillance. These elements are: vadose and saturated zones hydrogeology, surface erosion, meteorology and radionuclides content in waters, soil and biota. Pairs of TDR (Time Domain Reflectometry) and pressure sensors, coupled with a meteorological station have been installed on site for the continuously measurement of the water content and matric potential changes due to the climate variations. The data will be used to follow the water balance, the pores water velocity and to calculate the infiltration rate. A new set of erosion rates experimentally determined by Pinhole test on surface soil ...

Energy Technology Data Exchange (ETDEWEB)

In this paper the concept of a composite power system stabilizer is investigated. This stabilizer comprises a properly designed, robust, conventional power system stabilizer (CPSS) and an auxiliary stabilizer (AS) which can be either a self-tuning stabilizer (ASTS) or a fixed-parameter stabilizer (AFPS). For small disturbances, the CPSS performs satisfactorily over a wide range of operating conditions. When large disturbances occur the auxiliary stabilizer augments the performance of the CPSS. It has been demonstrated that the composite power system stabilizer can significantly improve the dynamic performance of the system when there is a major disturbance such as a short circuit in the system. Because in the case of a single-machine system the parameters of the ASTS do not vary appreciably, it can also be implemented as ...

CERN Document Server

We study the redshift evolution of galaxy pair fractions and merger rates for different types of galaxies using kinematic pairs selected from the DEEP2 Redshift Survey. Parameterizing the evolution of the pair fraction as (1+z)^{m}, we find that the companion rate increases mildly with redshift with m = 0.41+-0.20 for all galaxies with -21 < M_B^{e} < -19. Blue galaxies show slightly faster evolution in the blue companion rate with m = 1.27+-0.35 while red galaxies have had fewer red companions in the past as evidenced by the negative slope m = -0.92+-0.59. We find that at low redshift the pair fraction within the red sequence exceeds that of the blue cloud, indicating a higher merger probability among red galaxies compared to that among the blue galaxies. With further assumptions on the merger time scale and the fraction of pairs that will merge, the galaxy major merger rates ...

Energy Technology Data Exchange (ETDEWEB)

Recent topics in the theoretical magnetohydrodynamic (MHD) analysis in the heliotron configuration are overviewed. Particularly, properties of three-dimensional equilibria, stability boundary of the interchange mode, effects of the net toroidal current including the bootstrap current and the ballooning mode stability are focused. (author)

CERN Document Server

The top-color assisted technicolor (TC2) mode predicts the existence of a pair of charged top-pions $\\pi^{\\pm}_t$. In this paper, we study the production of the charged top-pions pair $\\pi^{\\pm}_t$ at next generation $\\gamma\\gamma$ colliders. The results show that the production rates can reach the level of $10^2$ fb with reasonable parameter space. With a large number of events and the clean background, the charged top-pion should be observable at the $\\gamma\\gamma$ colliders. Therefore, our studies can help us to search for charged top-pion, and furthermore, to test the TC2 model.

Science.gov (United States)

Since the elucidation of the structure of double helical DNA, the construction of small molecules that recognize and react at specific DNA sites has been an area of considerable interest. In particular, the study of transition metal complexes that bind DNA with specificity has been a burgeoning field. This growth has been due in large part to the useful properties of metal complexes, which possess a wide array of photophysical properties and allow for the modular assembly of an ensemble of recognition elements. Here we review recent experiments in our laboratory aimed at the design and study of octahedral metal complexes that bind DNA non-covalently and target reactions to specific sites. Emphasis is placed both on the variety of methods employed to confer site-specificity and upon the many applications for these complexes. Particular attention is given to the family of complexes recently designed that target single base mismatches in duplex DNA through ...

Energy Technology Data Exchange (ETDEWEB)

Passive films formed on Alloy 690 in high-temperature alkaline environments were investigated by potentiodynamic polarization, X-ray photoelectron spectroscopy, transmission electron microscopy and Mott-Schottky approach. Passive current density and donor density of the passive films increase with increasing temperature, due to increased diffusion rates of metallic ions and dehydration of hydroxide phases. The passive films show a duplex structure including an inner layer of fine-grained Cr oxide or spinel oxide and an outer layer of Ni-Fe spinel oxide and Ni hydroxide. A growth model of the passive films on Alloy 690 in high-temperature alkaline environments is proposed and discussed.

Energy Technology Data Exchange (ETDEWEB)

Chemical characterization of passive films formed on AISI 304 austenitic stainless steel, in a borate/boric acid solution at pH 9.2, under various conditions of potential, temperature, and polarizations time, was made by Auger electron spectroscopy combined with ion sputtering, and x-ray photoelectron spectroscopy (XPS). The depth chemical composition, thickness, and duplex character of the passive layers were determined after processing AES sputter profiles by their quantitative approach based on the sequential layer sputtering model. Moreover, separated contributions of elements in their oxidized and unoxidized state could be disclosed from part to part of the oxide-alloy interface. The XPS study specified the chemical bondings which take placed inside the film, between Fe and oxygen (and water).

International Nuclear Information System (INIS)

The chemical composition and the semiconducting properties of passive films formed on nickel based alloy (Alloy 600) in acidic sulphate solution, pH 2.0 at room temperature were studied using Auger analysis, voltammetric techniques and the Mott-Schottky approach. The results obtained revealed that the presence of both chromium and mixed nickel-iron oxides in the films leads to the development of a p-n heterojunction, which controls their electronic structure, similarly manner to the case of stainless steels and Alloy 600 in borate buffer solution. This behavior has been interpreted as representing of an oxide system, which has a duplex character, with an inner p-type semiconducting region, mainly formed by chromium oxide and an outer n-type semiconducting region, containing iron oxide. It could also be observed that the nickel oxide present in the films acts as a barrier layer conferring improved protection.

Science.gov (United States)

Models are proposed which explain the mechanism of action on a molecular level for the initiation of cancer by electrons or alpha particles. (ACR)

International Nuclear Information System (INIS)

We consider the electron-positron pair creation by a photon in an external constant electric field. The presented treatment is based on a purely quasiclassical calculation of the imaginary part of the on-shell photon polarization operator. By using this approach we find the pair production rate for photons with polarization parallel as well as orthogonal to the external electric field in the leading order in the parameter eE/m"2, which has been recently found by other methods. For the orthogonal polarization we also find a new contribution to the rate, which is leading in the ratio of the photon energy to the electron mass #omega#/m. We also reproduce by a purely geometrical calculation the exponential factor in the probability of the stimulated pair creation at arbitrary energy of the photon.

CERN Document Server

An analysis of the cross section for hadronic production of gluino-squark pairs close to threshold is presented. Within the framework of non-relativistic QCD a significant enhancement compared to fixed order perturbation theory is observed which originates from the characteristic remnants of the gluino-squark resonances below the nominal pair threshold. The analysis includes all colour configurations of S-wave gluino-squark pairs, i.e. triplet, sextet and 15 representation. Matching coefficients at leading order are separately evaluated for all colour configurations. The dominant QCD corrections, arising from initial- and final-state radiation are included. The non-relativistic dynamics of the gluino pair is solved by calculating the Green's function in Next-to-Leading Order (NLO). The results are applied to benchmark scenarios, based on Snowmass Points and Slopes (SPS). As a consequence of the large ...

International Nuclear Information System (INIS)

Leptonic pair production on nuclei ad EMC-effect are discussed within the frames of the flucton model with scaling distortion. Cumulative production of direct photons and leptonic pairs as a test of the model of hard collisions is considered. The results of calculations of massive leptonic pair production cross sections on nucleus fluctons, caculations of the ratio of deuterium and iron structural functions, cross sections of direct photon production on sup(181)Ta nuclei at Esub(p)=400 GeV and cross section of #pi#-meson production in the model of hard collisions are presented. Experimental discovery of direct cumulative photons is concluded to be important for understanding the mechanism of parton hard scattering from nucleus fluctons.

International Nuclear Information System (INIS)

Counter rotating longitudinal vortices produced by winglet in a channel are known to enhance heat transfer. In the present investigation the flow structure and heat-transfer enhancement by a winglet pair of non-zero thickness has been studied. A delta winglet pair type vortex generator is placed in a hydrodynamically developed and thermally developing laminar channel flow. Computations are done by solving the unsteady, three-dimensional, incompressible Navier-Strokes equations and energy equation using a modified Marker-and-Cell (MAC) method. The flow structure is complex and consists of main, corner and induced vortices. It is observed that as compared to a channel without winglets, the heat transfer is enhanced by 33% when single winglet is used and by 67% when a winglet pair is employed. Effects of thickness of the winglets and Reynolds number on the heat transfer augmentation are presented.

UK PubMed Central (United Kingdom)

We describe the stabilization by pressure of enzymes, including a hydrogenase from Methanococcus jannaschii, an extremely thermophilic deep-sea methanogen. This is the first published...Full Text Available

CERN Document Server

In this note, we have shown special case on Routh stability criterion, which is not discussed, in previous literature. This idea can be useful in computer science applications.

Energy Technology Data Exchange (ETDEWEB)

A novel adaptive stabilizer, called an Adaptive Governor Power System Stabilizer (AGPSS), which operated on the governor turbine system, was described. There has been extensive research on adaptive excitation control of generators in power systems with the goal of achieving better dynamic performance. AGPSS tracks the frequency and damping of oscillations in a power system, and adjusts to ensure that there is always sufficient damping in the system. There is no interaction between stabilizers on different generating units, and each one acts independently, consuming oscillation energy locally. These stabilizers are easy to design and this facilitates their use in multimachine systems. Results obtained by nonlinear simulation of a single-machine and a three-machine power system were discussed, illustrating the effectiveness of the stabilizers in supplying damping and improving ...

Energy Technology Data Exchange (ETDEWEB)

In this study samples of AISI 4140 steel were pretreated by plasma nitriding and coated with two different physical vapour deposited coatings (TiN and TiAlN). A hardened AISI 4140 sample and a coated sample were also included in the investigation. To examine the influence of the nitrided zone on the performance of the coating-substrate composite, two different nitriding conditions - a conventional 25% N{sub 2} and an N{sub 2}-poor gas mixture - were used. The specimens were investigated with respect to their microhardness, surface roughness, scratch adhesion and dry sliding wear resistance. Wear tests in which the duplex-treated pins were mated to hardened ball bearing steel discs were performed in a pin-on-disc machine under dry sliding conditions. Metallography, scanning electron microscopy and profilometry were used to analyse the worn surfaces in order to determine the dominant friction and wear characteristics of the samples investigated. The results show ...

Energy Technology Data Exchange (ETDEWEB)

We analyze spin correlations between top quark and anti-top quark produced at polarized e{sup +} e{sup -} and {gamma}{gamma} colliders. We consider a generic spin basis to find a strong spin correlation. Optimal spin decompositions for top quark pair are presented for e{sup +}e{sup -} and {gamma}{gamma} colliders. We show the cross- section in these bases and discuss the characteristics of results.

UK PubMed Central (United Kingdom)

We used microarrays and a previously established linkage map to localize the genetic determinants of brain gene expression for a backcross family of lake whitefish species pairs (Coregonus sp.). Our...Full Text Available

Energy Technology Data Exchange (ETDEWEB)

The electron scattering form factor for excitation of the 1/sup +/ state of /sup 88/Sr at 3.486 MeV has been calculated in the quasiparticle random phase approximation (QRPA). The disagreement between the data and restricted shell-model calculations can be explained in terms of the pairing correlations introduced by the QRPA; no ..delta..-h admixtures are required.

International Nuclear Information System (INIS)

The point-defect-impurity pair diffusion model proposed recently by Mulvaney and Richardson is adopted and modified to simulate the coupled diffusion of phosphorus and self-interstitials in phosphorus-implanted silicon. The assumption of implantation-induced, but empirically determined initial interstitial distributions of Gaussian shape allows a simulation of the net effect of transient enhanced diffusion. As a result an improved modeling of phosphorus diffusion in silicon is achieved for a broad range of ion-implantation and annealing conditions. (author).

International Nuclear Information System (INIS)

We study the signals for composite vector leptoquarks in e"+e- colliders (CERN e"+e- collider LEP II, Next Linear Collider, and CERN Linear Collider) through their effects on the production of jet pairs, as well as their single and pair productions. We also analyze their production in #gamma#e and #gamma##gamma# collisions.

KoreaScience (Korea)

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KoreaScience (Korea)

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Energy Technology Data Exchange (ETDEWEB)

No abstract prepared.

Energy Technology Data Exchange (ETDEWEB)

A micro-computer based fuzzy logic power system stabilizer is applied to a micro-machine system to investigate its efficiency in real time control. The stabilizing signal is determined by using measured speed or real power signals at every sampling time to damp the system oscillations. The results show the proposed stabilizer improves the system damping effectively subject to various types of disturbances.

Energy Technology Data Exchange (ETDEWEB)

A mathematical model of the multi machine electric power system to analyse its dynamics has been worked out. The effectivity of the power system stabilizer developed in the one machine system has been tested by means of this model. The influence of the arrangement of the stabilizers on the stability of the electric power system has also been investigated. High damping of electromechanical transient processes has been achieved. 7 refs., 1 tab., 5 figs.

Science.gov (United States)

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

Science.gov (United States)

Impediments to the Creation of a Specialized ... 4. TITLE AND SUBTITLE Impediments to the Creation of a Specialized Force for Stability Operations ...

KoreaScience (Korea)

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KoreaScience (Korea)

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Energy Technology Data Exchange (ETDEWEB)

The basic function of a Power System Stabilizer (PSS) is to add damping to the generator rotor oscillations by controlling its excitation using auxiliary stabilizing signals. To provide damping, the stabilizer must produce a component of electrical torque in phase with the rotor speed deviations. This paper introduces the hardware specifications and various functions of microprocessor (TMS320C32)-based digital PSS to provide the damping torque. (author). 3 refs., 6 figs.

International Nuclear Information System (INIS)

Laser-induced change is studied of the optical absorption and luminescence due to F-H pairs generated by an electron pulse in SrF_2. It is found that laser irradiation near 2.34 eV at a delay of 26 #mu#s after an electron pulse by which F-H pairs are generated reduces the component I of the pairs that has a decay time of 59 #mu#s and optical absorption bands at 2.34 and 4.13 eV and enhances the component II that has a decay time of 7.7 ms and has optical absorption bands at 2.7 and 3.35 eV. Laser irradiation near 2.7 eV at a delay of 4 ms after the electron pulse is found to induce the reverse reaction. Studies of dichroism of the laser-induced reduction and enhancement of the optical absorption bands and the luminescence reveal that the direction of the #SIGMA#-#SIGMA# transition of the F_2"- molecular ion is converted by the transformation from I to II and vice versa. It is suggested that the component I corresponds to ...

International Nuclear Information System (INIS)

Proton and neutron transfer populating low-lying states have been studied in the system "1"4"4Sm+"8"8Sr at an energy below the Coulomb barrier. The experimental cross sections for the single proton transfer are well reproduced by DWBA-calculations using spectroscopic information from light ion reactions. The two-proton transfer appears enhanced relative to the uncorrelated sequential transfer of single protons. The same holds for the transfer of proton pairs, the enhancement is kept for the second pair. This is interpreted as a supercurrent between two superfluid nuclear proton-pair wave functions: More mass and charge is transported per time unit in pairs than by single nucleons. Neutron transfer is observed with large cross sections and is found to contribute to the energy loss observed in the transfer reactions. For mixed proton-neutron transfers the sequential nature of the transfer reactions is ...

Energy Technology Data Exchange (ETDEWEB)

Slope stability can be a major problem during the construction of surface facilities. Cutting into existing ground disturbs the mechanics of the surrounding area, which can result in landslides and rock falls. This practical reference gives you the comprehensive information you need for slope stability analysis, suitable methods of analysis with and without the use of computers, and examples of common stability problems and stabilization methods for cuts and fills. It includes detailed discussions of methods used in slope stability analysis, including the Ordinary Method of Slices, Simplified Janbu Method, Simplified Bishop Method, Spencer`s Method, other limit equilibrium methods, numerical methods, total stress analysis, effective stress analysis, and the use of computer programs to solve problems. Chapters include: General Slope Stability Concepts; ...

Energy Technology Data Exchange (ETDEWEB)

The damping of unwanted oscillations in the generator units after a failure can be realized by installing a stabilizer between f.e. the revs of the generator and an input of the voltage regulator. The tuning of a Power System Stabilizer (PSS) is investigated using bode plots. Eigenvalue analysis shows an enlarged system stability margin. The method was tested on an advanced analogue power system simulator. As a result of these tests it appears to be useful to consider the stability as well as the optimal tuning. 5 figs., 6 refs.

Science.gov (United States)

We propose a quantum secure direct communication scheme based on non-orthogonal entangled pairs and local measurement. In this scheme, we use eight non-orthogonal entangled pairs to act as quantum channels. Due to the non-orthogonality of the quantum channels, the present protocol can availably prohibit from all kinds of valid eavesdropping and acquire a secure quantum channel. By local measurement, the sender acquires a secret random sequence. The process of encoding on the random sequence is identical to the one in one-time-pad. So the present protocol is secure. Even for a highly lossy channel, our scheme is also valid. The scheme is feasible with present-day techniques.

Energy Technology Data Exchange (ETDEWEB)

I describe a search for anomalous production of Z pairs through a new massive resonance X in 2.5-2.9 fb{sup -1} of p{bar p} collisions at {radical}s = 1.96 TeV using the CDFII Detector at the Fermilab Tevatron. I reconstruct Z pairs through their decays to electrons, muons, and quarks. To achieve perhaps the most efficient lepton reconstruction ever used at CDF, I apply a thorough understanding of the detector and new reconstruction software heavily revised for this purpose. In particular, I have designed and employ new general-purpose algorithms for tracking at large {eta} in order to increase muon acceptance. Upon analyzing the unblinded signal samples, I observe no X {yields} ZZ candidates and set upper limits on the production cross section using a Kaluza-Klein graviton-like acceptance.

British Library Electronic Table of Contents (United Kingdom)

One of the main causes of hip prostheses failure is the premature wear of its components. Wear of metal-on-metal joints is a concern due to the toxicity and biological reaction of wear debris and metallic corrosion. The main aim of the present study was to investigate the tribological and corrosion behavior of surface engineering CoCrMo alloy. Different surface conditions were obtained on surgical grade wrought CoCrMo alloy: plasma nitrided (520^oC by 7h at gas mixture of 10% N2+90% H2), PVD coated (monolayer CrN and multilayer (TiN/CrN)x3) and modified using duplex surface engineering technology (a combination of the two previous approaches: plasma nitriding followed by plasma assisted PVD). Surfaces were characterized using scanning electron microscopy, nanoindentation, AFM and scratch t...

Energy Technology Data Exchange (ETDEWEB)

To avoid the drop in corrosion resistance of stainless steels in conventional nitriding (precipitation of CrN), low-temperature techniques like ion implantation, plasma immersion ion implantation (PIII, PI{sup 3}) and low-temperature plasma nitriding were developed. In this investigation, four stainless-steel grades (ferritic: X6Cr17, austenitic-ferritic: X2CrNiMoN22.5.3, austenitic: X8CrNiTi18.10 and X5CrNi18.10) were plasma-nitrided between 250 and 500 C. Nitrogen-enriched layers with a high nitrogen content were produced, leading to a significant increase in surface hardness. X-ray diffraction indicated that CrN did not precipitate if treatment temperatures did not exceed 400 C. 'Expanded austenite' formed in the austenitic and duplex steels and {epsilon}-nitride (Fe{sub 2}N{sub 1-x}) in the ferritic steel. The optically visible structure of the nitrided cases is comparable with that of the PIII layers, with higher charging densities being ...

International Nuclear Information System (INIS)

Fatigue-crack growth in air and in aqueous 3.5-percent NaCl as well as fracture toughness are evaluated for the metastable beta-titanium alloy Ti-3Al-8V-6Cr-4Mo-4Zr in various microstructural conditions. Two solution heat treatments (SHT), 800 C and 927 C, were chosen to produce two different grain sizes. Approximately 20 vol pct unrecrystallized beta grains remained after SHT at the lower temperature. Yield stresses were 895 and 850 MPa, respectively. Both simplex and duplex aging treatments were performed for both grain sizes to vary the distribution of alpha precipitates while keeping the yield stress in the range of 1075-1220 MPa for all aged conditions. Unaged material exhibits significantly higher fracture toughness levels than aged material. The unrecrystallized regions were associated with a loss in ductility and toughness. 21 refs.

Energy Technology Data Exchange (ETDEWEB)

Austenitic stainless steel castings, such as SCS 13, SCS 14, which consists of {delta}/{gamma} duplex phase, are extensively used as structural material in seawater environments. It is known that SCS 14 involving 2wt% Mo is more resistant to pitting corrosion than SCS 13. In this paper, effects of Mo on the pitting corrosion are discussed in terms of microstructure of the material. The corrosion behavior of the materials with different {delta} ferrite contents and cleanlinesses have been evaluated by seawater exposure testing, electrochemical polarization, and TEM-EDX analysis. The results indicate that pits mainly nucleate at nonmetallic inclusions such as MnS and {delta}/{gamma} boundaries, and materials containing {delta} ferrite above 7vol% have high pitting corrosion resistance. The nucleation at {delta}/{gamma} boundaries is assumed to be due to the segregation of P. It is considered that because of segregation of Mo along {delta}/{gamma} boundaries, SCS 14 ...

CERN Document Server

This paper studies neighbor discovery problem in wireless networks. A novel scheme, called compressed neighbor discovery is proposed, which assigns each node a unique signature and let nodes simultaneously transmit their signatures during the discovery period. The query node then determines, based on the superposition of the signatures, a small number of nodes as its neighbors, out of a large number of nodes in the network. This is fundamentally a sparse recovery problem. Using the proposed scheme, a single frame time suffices to achieve reliable discovery for large networks. This is in contrast to conventional schemes, where each node repeatedly transmits its identity with random delay, so that a receiver can identify each neighbor at least once without collision. Two practical, low-complexity discovery schemes are studied. The first scheme assigns sparse pseudo-random on-off signatures to the nodes, so that each node can listen to the channel during its own off-slots. Despite of ...

UK PubMed Central (United Kingdom)

We report a whole-genome shotgun assembly (called WGSA) of the human genome generated at Celera in 2001. The Celera-generated shotgun data set consisted of 27 million sequencing reads organized in pairs...Full Text Available

UK PubMed Central (United Kingdom)

The genes which encode glycosomal glyceraldehyde-phosphate dehydrogenase (gGAPDH) of Trypanosoma cruzi are arranged as a tandemly repeated pair on a single chromosome and are identical at the level...Full Text Available

CERN Document Server

Some extensions of the Standard Model often predict a Z'gauge boson which mediates flavor-changing neutral-current (FCNC) interaction between up and top quarks. These new physics models are phenomenologically attractive because they can explain the top quark forward-backward asymmetry $A^t_FB$ measured recently by the Tevatron collider. In addition, they will induce the top quark FCNC decays and the like-sign top pair production which can be explored at the LHC. In this work we focus on two such models (the left-right model and the $U(1)_X$ model) to investigate their correlated effects on $A^t_FB$, the FCNC decays $t -> u V (V=g,Z,\\gamma)$ and the like-sign top pair production at the LHC. We also pay special attention on the most recently measured $A^t_FB$ in the large invariant mass region. We find that under the current experimental constrains both models can alleviate the deviation of $A^t_FB$ and, meanwhile, enhance some FCNC decays ...

UK PubMed Central (United Kingdom)

Purpose.Since 2002, six blind patients have undergone implantation of an epiretinal 4 × 4 electrode array designed to directly stimulate the remaining cells of the retina...Full Text Available

UK PubMed Central (United Kingdom)

Digestion of plant chromatin from Brassica pekinensis and Matthiola incana with staphylococcus nuclease leads to a DNA repeat of 175 plus or minus 8 and a core size of 140 base pairs. DNase I digestion...Full Text Available

UK PubMed Central (United Kingdom)

The T-loop motif is an important recurrent RNA structural building block consisting of a U-turn sub-motif and a UA trans Watson–Crick/Hoogsteen base pair. In the presence of...Full Text Available

UK PubMed Central (United Kingdom)

We report the use of cysteine-substituted mutants in conjunction with in situ oxidation to determine the physical proximity of a pair of engineered cysteines in the pore region of the voltage-gated...Full Text Available

UK PubMed Central (United Kingdom)

Activation-induced cytidine deaminase (AID) protein initiates Ig gene mutation by deaminating cytosines, converting them into uracils. Excision of AID-induced uracils by uracil-N-glycosylase...Full Text Available

UK PubMed Central (United Kingdom)

Alcohol dependence (AD) is clinically and etiologically heterogeneous. The goal of this study was to explore AD subtypes among a sample of 1, 221 participants in the Irish Affected Sib Pair...Full Text Available

UK PubMed Central (United Kingdom)

BackgroundGene duplication is the primary force of new gene evolution. Deciphering whether a pair of duplicated genes has evolved divergent functions is often challenging. The zebrafish...Full Text Available

UK PubMed Central (United Kingdom)

PCR was used with the primer pair VANS1-NS21 to detect the arbuscular mycorrhizal fungus Glomus intraradices (commercial inoculum source) on roots of lettuce, zinnia, leek, pepper, and endive plants....Full Text Available

UK PubMed Central (United Kingdom)

Competent Haemophilus cells recognize and preferentially take up Haemophilus DNA during genetic transformation. This preferential uptake is correlated with the presence on incoming DNA of an 11-base-pair...Full Text Available

UK PubMed Central (United Kingdom)

The cellular properties of long-term potentiation (LTP) following pairing of pre- and postsynaptic activity were examined at a known glutamatergic synapse in the leech, specifically between the pressure...Full Text Available

UK PubMed Central (United Kingdom)

Recent evidence suggests a role for corticotropin-releasing factor (CRF) in the regulation of pair bonding in prairie voles. We have previously shown that monogamous and non-monogamous vole...Full Text Available

International Nuclear Information System (INIS)

A G-matrix, derived from a meson-exchange potential in nuclear matter, is applied to finite, semi-magic nuclei. For the open shell the broken-pair model, which can accommodate many single-particle levels, is used. The excitations of the closed shell are treated as particle-hole states. Energy spectra and electromagnetic transition densities are calculated for "8"8Sr and "5"8Ni. The energies of the non-collective states are well described. Pairing correlations in the ground state have almost the correct strength in a multishell model space. To improve the energies of the collective 2"+ and 3"- states the inclusion of core-polarisation effects in the force is required. Transition charge densities for collective states become strongly surface-peaked by core-polarisation effects, as is observed in experiments. The effects of pairing correlations and core polarisation on the magnetic form factor of the 3.486 MeV 1"+ state in ...

UK PubMed Central (United Kingdom)

The “cloverleaf” base-pairing pattern was established as the structural paradigm of active tRNA species some 30 years ago. Nevertheless, this pattern does not accommodate the folding...Full Text Available

UK PubMed Central (United Kingdom)

BackgroundGenotyping analysis using capillary DNA sequencing with fluorescently labeled primer pairs obtained by polymerase chain reaction (PCR) is widely used, but is expensive....Full Text Available

Energy Technology Data Exchange (ETDEWEB)

By isomorphous replacement of silicon by phosphorus the authors have synthesized crystalline aluminosilicophosphates with structures of the zeolites type A and faujasite. They determine the adsorption capacity of specimens treated at 575-1275/sup 0/K. They show that the thermal stability and acid resistance of aluminosilicophosphates depend on the quantity of phosphorus in their structure.

Energy Technology Data Exchange (ETDEWEB)

Several low-mass models with an inhomogeneous radiative core and a convective envelope are investigated, the entire core or its upper portion being treated as a zone of neutral stability. Mixing by convective overshoot will then give rise to unstable structure.

UK PubMed Central (United Kingdom)

The stability of catalase, fumarase, and isocitrate lyase from deliberately broken organelles in crude extracts from endosperm tissue of castor bean seedlings has been examined. These enzymes are relatively...Full Text Available

UK PubMed Central (United Kingdom)

Tubular membrane structures are widespread in eukaryotic cells, but the mechanisms underlying their formation and stability are not well understood. Previous work has focused on tube extrusion from...Full Text Available

UK PubMed Central (United Kingdom)

Treatment of poliovirus Type I with 10⁻³m 2-thiouracil (2-TU) resulted in the inactivation of greater than 90% of the virus infectivity and stabilization of approximately...Full Text Available

UK PubMed Central (United Kingdom)

Numerous studies have noted that the evolution of new enzymatic specificities is accompanied by loss of the protein's thermodynamic stability (ΔΔG), thus suggesting...Full Text Available

International Nuclear Information System (INIS)

This paper presents a practical case study on the dynamic stability of the Saudi Electricity Company (SEC) power system and its effect on increasing power transfer limit of the interconnection between Eastern Operating Area (SEC-EOA). The problem of optimal tuning of the power system stabilizer parameters was converted into optimization problem wth eigenvalue-based objective functions, which was then solved by genetic algorithms. In this regard, two eigenvalue-based objective functions were considered and the problem is solved using real-coded genetic algorithm (RCGA). The effectiveness of the suggested technique to enhance the power system dynamic stability and to extend the power transfer capability limit of the SEC-EOA and the SEC-EOA power system was verified through a comprehensive eigenvalue analysis and time-domain nonlinear simulation. The results also indicated that the proposed tuning schemes of the existing ...

UK PubMed Central (United Kingdom)

Alpha-hemoglobin-stabilizing protein (AHSP) is an erythroid-specific protein that acts as a molecular chaperone for the free α chains of hemoglobin. Evidence strongly suggests...Full Text Available

UK PubMed Central (United Kingdom)

A general procedure for stabilization of O2-labile enzymes exploiting "salting out" of oxygen from the microenvironment in the molecular layers immediately adjacent to charged surfaces of polyionic...Full Text Available

Energy Technology Data Exchange (ETDEWEB)

We review some interesting virtual effects from the minimal supersymmetric model (MSSM) at {gamma}{gamma} colliders. We conclude that in the research respects, such as supersymmetric particle pair production, CP-violation and electroweak-like one-loop corrections in top quark pair production, the FCNC in the R{sub p}-violating MSSM, linear collider (LC) operating in photon-photon collision mode provides powerful facilities in the measurements of new physics objects. For a precise and thorough study of the new physics, the investigation of the supersymmetric quantum effects is necessary. (author)

Energy Technology Data Exchange (ETDEWEB)

By its very nature redox potential measurement is suitable for determining the concentration ratio of a stable redox pair through its interaction with a chemically inert electrode surface but not the absolute concentration of a material. The measured redox potentials agree only rarely with those which are easily calculable theoretically. No individual defined stable redox pair is available in power station water. It is therefore not simply possible to measure definable mixed potentials more precisely. For these reasons redox potential measurement in the power station, as also with other types of water, can no longer be regarded as an indicator, by which it can be established whether oxidizing or reducing materials predominate in the water.

Energy Technology Data Exchange (ETDEWEB)

We present methods to measure the beam polarizations and the luminosity of [gamma][gamma] colliders at TeV energy scale. The beam polarizations of a [gamma][gamma] collider can easily be monitored by comparing the numbers of events of the processes [gamma][gamma] [yields] l[sup +]l[sup -] and [gamma][gamma] [yields] W[sup +] W[sup -], where l means e or [mu]. The luminosity of a [gamma][gamma] collider is also measurable by the event rate of W boson pair productions and the light lepton pair productions. (orig.)

International Nuclear Information System (INIS)

Feasibility of using sterile females for population suppression of Earias vittella (Fabricius) was evaluated by conducting studies on mating competitiveness of radiation sterilized females, both in individual pairs and in simulated large population conditions. Results showed that sterility induced by using a 10:1:1 ratio (sterile female: normal female: normal male) in single pair experiments and also in simulated large population conditions was more than 99.0 per cent. Release of radiation- sterilized females of E. vittella in natural populations has thus an excellent potential for population suppression. (author)

Energy Technology Data Exchange (ETDEWEB)

The total and differential atomic pair-correlation functions of an icosahedral (quasicrystalline) solid were determined for the first time, directly by the differential anomalous-x-ray-scattering technique using synchrotron radiation. The observed atomic distances involving uranium atoms in icosahedral Pd/sub 58.8/U/sub 20.6/Si/sub 20.6/ suggest the presence of a quasicrystalline sublattice with vertex decoration. The pair distribution functions in the icosahedral and amorphous phases are similar up to the second-nearest neighbors, or up to 6 A-circle.

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.

Science.gov (United States)

... core section of the composite sandwich panels (Figure 5). Table 6 shows the properties that buckled as well as their initial ...

Science.gov (United States)

... The general two-phase Stefan problem with supercooling, superheating, and capillarity, was studied [T19] in collaboration ...

Energy Technology Data Exchange (ETDEWEB)

In this article, a continuous stabilization process was used to make flame resistant fibers from polyacrylonitrile (PAN) fibers. The effect of the stabilization time and the stretching process during the stabilization process on the physical properties and flammability of the resultant flame resistant fibers was studied. Increased drawing of PAN fibers during the continuous stabilization process was found to decrease the diameter and increase the tensile strength in the resultant flame resistant fibers. These fibers also had higher density. There were no absolute relationships seen between flame-resistance and the formation of stable ladder polymers, density, and oxygen content. ((orig.))

Energy Technology Data Exchange (ETDEWEB)

The fuzzy polar power system stabilizer (FPPSS) which has been recently developed is analyzed using frequency domain methods. the frequency domain approach allows the PSS designer to compare the new FPPSS with more conventional controllers. The significance of the three FPPSS design parameters are readily seen from the frequency response data, and their relationship to the conventional lead-lag design approach can be evaluated. Furthermore, the frequency response data for the FPPSS allows an alternate design approach for this stabilizer, and can be used to develop information concerning the small signal stability of the resulting system.

Energy Technology Data Exchange (ETDEWEB)

This paper proposes the design of LQ-PSS (linear quadratic power system stabilizer) for improving power system stability using genetic algorithm(GA). We are turned weighting matrices of LQ-PSS using GA. To evaluate the usefulness of the proposed method, we performed the nonlinear simulation on a single machine infinite system. As results on a single machine infinite system. As results of the simulation, the proposed method shows the better control performance than CPSS(conventional power system stabilizer) in terms of settling time and damping effects. (author). 7 refs., 7 figs., 3 tabs.

Science.gov (United States)

PMID:21846114

International Nuclear Information System (INIS)

Published in summary form only.

International Nuclear Information System (INIS)

... Tsukuba, Ibaraki (Japan) 389 p. PARTICLE ACCELERATORS beam monitoring

CERN Document Server

Kelvin-Helmholtz instability of short gravity waves is examined in order to explain the recent findings of the decrease in momentum transfer from hurricane winds to sea waves. A three-fluid configuration of a foam layer between the atmosphere and the ocean is suggested to provide signifficant stabilization of the system and shifting the marginal critical wavelength to the shortwave part of the spectrum. It is conjectured that such stabilization leads to the observed drag reduction. The high contrasts in three fluid densities provide a universal mechanism for stabilizing surface perturbations.

Science.gov (United States)

A method is presented for calculating the thermal stability of blast furnace coke over a wide range of sizes, based on a study of the coke behaviour pattern in the blast furnace and the change in its thermo-elastic properties during reheating. Using as an example a Novolipetsk metallurgical plant, the possibility was demonstrated of using the thermal stability index calculated by the proposed method for an unambiguous assessment of the quality of blast furnace coke.

Energy Technology Data Exchange (ETDEWEB)

At DORIS II/HASYLAB a vertical beam position control system is in regular operation. It controls the position and angle of a photon beam simultaneously, and can stabilize beam movements up to frequencies of 0.1 Hz. To suppress beam vibrations up to 50 Hz and above, a prototype beam stabilization system for these frequencies was built and tested successfully. The present beam oscillations at the HASYLAB beamlines are explained, the quality of the beam position control system and the results of the prototype test are presented.

CERN Document Server

We extend two results on Chow (semi-)stability to positive characteristics. One is on the stability of non-singular projective hypersurfaces of degree greater than 2, and the other is the criterion by Y. Lee in terms of log canonical thresholds. Some properties of log-canonicity in positive characteristics are discussed with a couple of examples, in connection with the proof of the latter one. It is also proven in appendix that the sum of Chow (semi-)stable cycles are again Chow (semi-)stable.

Energy Technology Data Exchange (ETDEWEB)

Dynamic stability improvement of a longitudinal power system using a power system stabilizer (PSS) and a static VAR compensator (SVC) is reported in this paper. An analytical approach is developed for the determination of PSS parameters. Results from time domain simulations indicate that the PSS and the SVC are very effective in damping system oscillations.

British Library Electronic Table of Contents (United Kingdom)

This paper mainly considers the asymptotic stability of interval neutral delay-differential systems, which corrects a technical error in the proof given in [Applied Math. Letters, 16(2003) 1063-1068] by a linear fractional transformation of an interconnection matrix with structured real parametric uncertainties. In addition, a new condition, in terms of the structured singular value, is provided to ensure the stability of the interval system. Finally, an example is given to demonstrate the validity of our criteria.

Energy Technology Data Exchange (ETDEWEB)

This paper addresses the stability aspects of several successful dc superconducting magnets such as large bubble chamber magnets, and magnets for the Mirror Fusion Test Facility and MHD Research Facility. Specifically, it will cover Argonne National Laboratory 12-Foot Bubble Chamber magnets, the 15-foot Bubble Chamber magnets at Fermi National Laboratory, the MFTF-B Magnet System at Lawrence Livermore National Laboratory, the U-25B Bypass MHD Magnet, and the CFFF Superconducting MHD magnet built by Argonne National Laboratory. All of these magnets are cooled in pool-boiling mode. Magnet design is briefly reviewed. Discussed in detail are the adopted stability critera, analyses of stability and disturbance, stability simulation, and the final results of magnet performance and the observed coil disturbances.

CERN Document Server

The Kosambi-Cartan-Chern (KCC) theory represents a powerful mathematical method for the analysis of dynamical systems. In this approach one describes the evolution of a dynamical system in geometric terms, by considering it as a geodesic in a Finsler space. By associating a non-linear connection and a Berwald type connection to the dynamical system, five geometrical invariants are obtained, with the second invariant giving the Jacobi stability of the system. The Jacobi (in)stability is a natural generalization of the (in)stability of the geodesic flow on a differentiable manifold endowed with a metric (Riemannian or Finslerian) to the non-metric setting. In the present paper we review the basic mathematical formalism of the KCC theory, and present some specific applications of this method in general relativity, cosmology and astrophysics. In particular we investigate the Jacobi stability of the general ...

British Library Electronic Table of Contents (United Kingdom)

Proper balance control is a key aspect of acitivities of daily living. The aim of this study was to determine the contribution of body weight to predict balance stability. The balance stability of 59 male subjects with BMI ranging from 17.4 to 63.8kg/m2 was assessed using a force platform. The subjects were tested with and without vision. A stepwise multiple regression analysis was used to determine the independent effect of body weight, age, body height and foot length on balance stability (i.e., mean speed of the center of foot pressure). With vision, the stepwise multiple regression revealed that body weight accounted for 52% of the variance of balance stability. The addition of age contributed a further 3% to explain balance control. Without vision, body weight accounted for 54% of the...

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).

Science.gov (United States)

Magnolia bark and ginger rhizome is a drug pair in many prescriptions for treatment of mental disorders in traditional Chinese medicine (TCM). However, compatibility and synergism mechanism of two herbs on antidepressant actions have not been reported. The aim of this study was to approach the rationale of the drug pair in TCM. We evaluated antidepressant-like effects of mixture of honokiol and magnolol (HMM), polysaccharides (PMB) from magnolia bark, essential oil (OGR) and polysaccharides (PGR) from ginger rhizome alone, and the possibility of synergistic interactions in their combinations in the mouse forced swimming test (FST) and tail suspension test (TST). Serotonin (5-HT) and noradrenaline (NE) levels in prefrontal cortex, hippocampus and striatum were also examined. 30 mg/kg HMM decreased immobility in the FST and TST in mice after one- and two-week treatment. OGR (19.5 or 39 mg/kg) alone was ineffective. The combination of an ...

Energy Technology Data Exchange (ETDEWEB)

The authors introduce the single electron (Cooper-pair) tunneling junctions using c-axis Bi{sub 2}Sr{sub 2}CaCu{sub 2}O{sub 8+d} (Bi-2212) superconducting single crystal whiskers. Focused-ion-beam (FIB) etching patterned the Bi-2212 whiskers. The fabricated small stacked junctions have in-plane area S smaller than <1 {micro}m{sup 2}. The junctions showed the current-voltage (I-V) characteristics with the periodic structure of current peaks. The stacking layered structure of Bi-2212 works as multi-junctions array which decrease the effective capacitance, C{sub {Sigma}} = C{sub 0}/N, where C{sub 0} is the capacitance of junction and N is the layer number of elementary junctions. The period of current peaks of I-V curves corresponds to the charging energy of the single Cooper pair, 2Ec (=e{sup 2}/C{sub {Sigma}}).

Energy Technology Data Exchange (ETDEWEB)

The device for removing drilling fines from the well head includes a support disk encompassing the sucker rod of the drilling machine with frame made in the form of a dish with inner conical surface, and overturned truncated cone located in the dish of the support disk with the formation between them of a ring guide slit. In order to improve the effectiveness of removing the drilling fines and convenience of operation by excluding heavy manual auxiliary operations to clean the well head and to move the device from one well to another, it is equipped with a mechanism for suspension with a drive. The inner conical surface of the dish is equipped with slide blocks, while the overturned truncated cone is equipped with projections. The suspension mechanism is made in the form of a hydrocylinder and two pairs of levers connected in pairs by means of hinges. The hinges of each pair of levers are connected to the hydrocylinder, and ...

Energy Technology Data Exchange (ETDEWEB)

The use of excitation system controls, specifically the Power System Stabilizer (PSS), to improve damping of power system oscillations and thus extend steady-state stability limits has been a subject of great interest in recent years. The desire to more fully utilize transmission capacity led to the installation of PSS controls on greater numbers of generating units to maintain stability margins. This paper addresses the tuning and adjustment of PSS controls in a two unit power plant. Both analytical studies and field test confirmations are presented. The practical difficulties of verifying the PSS control loop gain margin by testing are explored. A simplified procedure is outlined. The Lower Colorado River Authority (LCRA), Fayette Power Project (FPP) consists of two 683.7 MVA tandem compound steam turbine driven generators. The excitation systems are of the alternator rectifier type and the PSS control utilizes shaft ...

International Nuclear Information System (INIS)

Laser frequency stabilization giving a 500-Hz Allan deviation for a 2-ms integration time with drift reduced to 7 kHz/min over several minutes was achieved at 1536 nm in the optical communication band. A continuously regenerated spectral hole in the inhomogeneously broadened "4I_1_5_/_2(1)#->#"4I_1_3_/_2(1) optical absorption of an Er"3"+:Y_2SiO_5 crystal was used as the short-term frequency reference, while a variation on the locking technique allowed simultaneous use of the inhomogeneously broadened absorption line as a long-term reference. The reported frequency stability was achieved without vibration isolation. Spectral hole burning frequency stabilization provides ideal laser sources for high-resolution spectroscopy, real-time optical signal processing, and a range of applications requiring ultra-narrow-band light sources or coherent detection; the time scale for stability and the compatibility ...

Energy Technology Data Exchange (ETDEWEB)

This paper introduces an indirect adaptive fuzzy controller as a power system stabilizer used to damp inter-area modes of oscillation following disturbances in power systems. Compared to the IEEE standard multi-band power system stabilizer (MB-PSS), indirect adaptive fuzzy-based stabilizers are more efficient because they can cope with oscillations at different operating points. A nominal model of the power system is identified on-line using a variable structure identifier. A feedback linearization-based control law is implemented using the identified model. The gains of the controller are tuned via a particle swarm optimization routine to ensure system stability and minimum sum of the squares of the speed deviations. A bench-mark problem of a 4-machine 2-area power system is used to demonstrate the performance of the proposed controller and to show its superiority over other conventional ...

British Library Electronic Table of Contents (United Kingdom)

The effect of the degree of degradation of the components of a model municipal plastic waste (a mixture of low-density polyethylene, high-density polyethylene, polypropylene and high-impact polystyrene) on the toughness and stability of recyclates compatibilised with a cooperative compatibilisation system (a mixture of ethylene-propylene statistical and styrene-butadiene block copolymers with a secondary amine-based stabiliser) was studied. It was shown that good impact strength was achieved for recyclates having components with a low or medium degree of degradation. Mechanical properties of recyclates having the components with a high degree of degradation are deteriorated. The addition of the cooperative compatibilisation system leads to a higher thermo-oxidative stability of recyclates ...

Energy Technology Data Exchange (ETDEWEB)

In recent years, the phase stability of austenitic stainless steels, and its effect on the mechanical properties of stainless steels, have been the subject of much interest. With the availability of new experimental techniques, new theoretical methods, and new computational procedures, significant advances have been made in understanding, and being able to predict, phase stability and mechanical properties of stainless steel welds. This paper reviews some of these developments, with an emphasis on recent work that has been done at Oak Ridge National Laboratory.

Energy Technology Data Exchange (ETDEWEB)

The problem of thermal instability of compressible, electrically conducting couple-stress fluids in the presence of a uniform magnetic field is considered. Following the linearized stability theory and normal mode analysis, the dispersion relation is obtained. For stationary convection, the compressibility, couple-stress, and magnetic field postpone the onset of convection. Graphs have been plotted by giving numerical values of the parameters to depict the stability characteristics. The principle of exchange of stabilities is found to be satisfied. The magnetic field introduces oscillatory modes in the system that were non-existent in its absence. The case of overstability is also studied wherein a sufficient condition for the non-existence of overstability is obtained. (orig.)

International Nuclear Information System (INIS)

The frequency dependence of the tunneling spectrum #alpha#"2F (#omega#) is analyzed in terms of electron pairing induced by exchange of acoustic plasmons in addition to the usual phonon-exchange mechanism. Analytic expressions are obtained for the electron self-energy, the tunneling function #alpha#"2F, and the electron pairing coupling lambda which determines the superconducting properties. The resulting theory is applied to recent tunneling data of Nb_3Sn in order to examine the anomalous discrepancies with the phonon density of states found by neutron scattering experiments. The results demonstrate how the high-temperature (T/sub c/ approx. 20 "0K) superconducting properties of A-15 compounds are enhanced by acoustic-plasmon contributions, and thus they reconcile these high transition temperatures with the relatively small values of the phonon part of lambda estimated from several independent experiments.

Science.gov (United States)

Porcine pancreatic lipase immobilized on celite particles has been employed as a catalyst for the esterification of dodecanol and decanoic acid in a predominantly organic system. Solvent influence on the equilibrium position and on the catalyst activity has been studied using 20 solvents, including aliphatic and aromatic hydrocarbons, ethers, ketones, nitro- and halogenated hydrocarbons, and esters. The equilibrium constant for esterification correlates well with the solubility of water in the organic solvent, which in turn shows a good relationship with a function of Guttman's donor number and the electron pair acceptance index number of the solvent. This may be rationalized in terms of the requirements for solvation of water and of the reactants. The catalyst activity, measured as the initial rate of the esterification reaction, is best correlated as a function of both n-octanol-water partition coefficient (log P) and either the electron pair ...

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The authors present the results of a search for W{prime} boson decaying to electron-neutrino pairs in p{bar p} collisions at a center-of-mass energy of 1.96 TeV, using a data sample corresponding to 205 pb{sup -1} of integrated luminosity collected by the CDF II detector at Fermilab. They observe no evidence for this decay mode and set limits on the production cross section times branching fraction, assuming the neutrinos from W{prime} boson decays to be light. If they assume the manifest left-right symmetric model, they exclude a W{prime} boson with mass less than 788 GeV/c{sup 2} at the 95% confidence level.

International Nuclear Information System (INIS)

The production of pairs of doubly charged vector bileptons is studied at future #gamma##gamma# colliders. The unpolarized cross section for the #gamma##gamma##->#Y"-"-Y"+"+ subprocess is analytically calculated and convoluted to predict the number of events in the complete e"+e"-#->##gamma##gamma##->#Y"-"-Y"+"+ process. The gauge or nongauge character of the vector bilepton Y"#+-#"#+-# is discussed. It is found that, as a consequence of its spectacular signature, as it decays dominantly into two identical charged leptons, and also due to its charge contents, which significantly enhance the cross section, the detection of this class of particles with mass in the sub-TeV region can be at the reach of these colliders. The model-independent nature of our results is stressed.

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Subcutaneous involvement frequently occurs in maxillary sinus carcinoma. Radical resection does not include removal of the skin at risk. In standard postoperative wedge-pair treatment plans, the surface dose is dependent upon beam weighting, beam energy, and patient contour. Thermoluminescent dosimetry (TLD) measurements were performed to evaluate the surface dose of patients undergoing postoperative irradiation of maxillary sinus carcinoma following primary resection. When 60 Gy was delivered to isocenter with a 45 degrees wedge pair and 6 MV photons with 1 cm bolus, the subcutaneous tissues at risk received {approximately} 30 Gy. Based upon presented TLD measurements, supplemental electron beam therapy to the subcutaneous tissues if primarily involved should be considered.

International Nuclear Information System (INIS)

The band crossing in "1"3"2Ba has been investigated by using the interacting boson model. A broken neutron pair has been coupled to a collective boson core. The boson-fermion interaction hamiltonian contains terms which can transform a boson into a pair of quasiparticles and vice versa. The parameters were partly determined by fitting the collective states of "1"3"2","1"3"4Ba and the yrast states of "1"3"1Ba. The energy backbending has been satisfactorily reproduced. Good agreement of the electromagnetic moments has been reached. The structure of the wave functions has been discussed. (author)

CERN Document Server

We present a method for grouping the synonyms of a lemma according to its dictionary senses. The senses are defined by a large machine readable dictionary for French, the TLFi (Tr\\'esor de la langue fran\\c{c}aise informatis\\'e) and the synonyms are given by 5 synonym dictionaries (also for French). To evaluate the proposed method, we manually constructed a gold standard where for each (word, definition) pair and given the set of synonyms defined for that word by the 5 synonym dictionaries, 4 lexicographers specified the set of synonyms they judge adequate. While inter-annotator agreement ranges on that task from 67% to at best 88% depending on the annotator pair and on the synonym dictionary being considered, the automatic procedure we propose scores a precision of 67% and a recall of 71%. The proposed method is compared with related work namely, word sense disambiguation, synonym lexicon acquisition and WordNet construction.

British Library Electronic Table of Contents (United Kingdom)

Thinning and burning forests established on revegetated mine pits in jarrah (Eucalyptus marginata) forests of south-west Australia is being considered as a management option to accelerate succession in sites with excessive tree densities. To assess the impact of thinning and burning on reptiles and small mammals, we installed trapping grids in eight thinned and burned sites, each paired with untreated controls. Of the eight pairs, four were in rehabilitated sites (planted with nonlocal species) and four were in restored sites (seeded with local species). Thinning and burning had no significant impact on the small mammal community, although Cercatetus concinnus was more abundant in rehabilitated sites. In contrast, thinning and burning significantly increased reptile abundance and species r...

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A dielectric-wall linear accelerator is improved by a high-voltage, fast rise-time switch that includes a pair of electrodes between which are laminated alternating layers of isolated conductors and insulators. A high voltage is placed between the electrodes sufficient to stress the voltage breakdown of the insulator on command. A light trigger, such as a laser, is focused along at least one line along the edge surface of the laminated alternating layers of isolated conductors and insulators extending between the electrodes. The laser is energized to initiate a surface breakdown by a fluence of photons, thus causing the electrical switch to close very promptly. Such insulators and lasers are incorporated in a dielectric wall linear accelerator with Blumlein modules, and phasing is controlled by adjusting the length of fiber optic cables that carry the laser light to the insulator surface. 12 figs.

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We have studied the vibrational properties of the filled tetrahedral semiconductor LiMgAs and its binary analog AlAs by using the plane-wave pseudopotential method within density functional theory. The calculated lattice constants for the studied compounds are in good agreement with previous theoretical and experimental results. The phonon dispersion curves and phonon density of states are calculated by using density functional perturbation theory. The sound speeds in different directions are quantitatively similar in LiMgAs and AlAs. The assignment of the zone center modes to the relative motion of the atoms shows that the lower optic modes are due to the Mg-As pair vibrations, while for the upper ones the Li-Mg pair dominates, which is attributed to the smaller Mg atom mass. The longitudinal interatomic force constant of Mg-As is about 66% higher than that of Li-As, showing the relatively high covalency of the former bond.

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Spectroscopy based on the Andreev reflection (AR) process at the interface between the normal metal tip and the superconductor has become one of the very successful methods for studies in novel exotic superconductors. The method is capable to address the size, symmetry as well as multiplicity of the superconducting order parameter. The method provided one of the first evidences of the two-gap superconductivity in MgB{sub 2} with a detailed temperature dependence of the both gaps. A theory treating the Andreev reflection spectroscopy in the mixed state is missing. We analyse the AR spectra of MgB{sub 2} in the mixed state via modelling the magnetic pair-breaking by the increasing spectral broadening parameter {gamma}. As a result a non-trivial pair breaking effect in the {pi}-band is found.

CERN Document Server

The pair-specific ground state energy of Newtonian N-body systems grows monotonically in N. This furnishes a whole family of simple new tests for minimality of putative ground state energies obtained through computer experiments. Inspection of several publically available lists of such computer-experimentally obtained putative ground state energies has yielded several dozen instances which failed (at least) one of these tests. Although the correct ground state energy is not revealed by this method, it does yield a better upper bound on it than the experimentally found value whenever the latter fails a monotonicity test. The surveyed N-body systems include in particular N point charges with 2- or 3-dimensional Coulomb pair interactions, placed either on the unit 2-sphere or on a 2-torus (a.k.a. Thomson, Fekete, or Riesz problems).

Science.gov (United States)

... Each beam finite element was derived using Hamilton's principle and the following basic assumptions: the beam has an arbitrary amount of pretwist ...

International Nuclear Information System (INIS)

A series of #alpha#-sialon (#alpha#') compositions containing mixed stabilising cations were prepared, by introducing additional CaO to a basic Sm #alpha#-sialon compositions. The thermal stability of these Sm-Ca-containing #alpha#-sialon phases was investigated using XRD, SEM and EDXS techniques. It was found that the addition of calcium into the Sm #alpha#-sialon systems greatly improved the stability of the #alpha#-sialon phases. Calcium was found to be incorporated into the #alpha#-sialon structure, coexistent with the samarium, and partitioning of the calcium and samarium was observed between the #alpha#' phase and grain boundary phases. This indicates a technique which may be used to improve the thermal stability of the #alpha#' phase while maintaining good refractory phases at the sialon grain boundaries.

Science.gov (United States)

verified via high-resolution spectral density measurements using the Hadamard Variance. .... spectral density measurements were made with the HF5390 ...

International Nuclear Information System (INIS)

... v. 14(8) p. 624-625. azido compounds cadmium complexes potentiometry

International Nuclear Information System (INIS)

A detailed treatment is introduced to measure the dynamic stability of the relativistic electrons in a self-amplified spontaneous emission free-electron laser (FEL) system, which includes the numerical approach of the Kolmogorov entropy (entropy-like quantity), the general equations of motion for a charged particle and the method of monitoring the simulation accuracy. Numerical experiments reveal a new phenomenon that there exists the possibility of the transition from chaotic to non-chaotic phase-space trajectories of the strongly relativistic electrons due to the effect of their self-fields. The adiabatic magnetic field of a one-dimensional wiggler may have a slight influence on the electron transportation in the absence of the FEL fields, but substantially affects the dynamic stability of the electrons in the process of the FEL interaction. Moreover, the laser fields diminish the dynamic stability of the electrons as the ...

UK PubMed Central (United Kingdom)

Recent increases in births to unmarried parents, and the instability surrounding these relationships, have raised concerns about the possible health effects associated with changes in family...Full Text Available

Science.gov (United States)

... f(i, k, α) if node k is the terminal node for ... under which the mean service rate at queue (i, k ... occur frequently in studies of stability in stochastic networks ...

International Nuclear Information System (INIS)

Soil placed over any sealant/barrier system can provide a protective mantle if the soil is not lost by erosion. Vegetation is an attractive choice for controlling erosion because it can provide an economic self-renewing cover that serves to reduce erosion by both wind and water. Vegetation alone, however, may not adequately stabilize the surface in extremely arid areas. In those areas, a properly designed surface treatment of rock cover, perhaps in conjunction with vegetation, may be necessary to stabilize the tailings surfaces. The objective of this program is to establish guidelines for surface stabilization that are compatible with sealant/barrier systems and that are suited to soils and climates at inactive uranium mill tailings sites. These guidelines will provide the means to estimate potential vegetation cover, potential erosion, effects of surface treatments on sealant/barrier systems, and costs of vegetation and ...

Energy Technology Data Exchange (ETDEWEB)

No abstract prepared

Science.gov (United States)

... at compositions below -AlP 4 the films were still unstable, hydrolysing in room air, and the long term stability of higher aluminium phosphides is in ...

Energy Technology Data Exchange (ETDEWEB)

A stable power system stabilizer (PSS) based on the inverse dynamics of the controlled system using an artificial neural network (ANN) is suggested to enhance the dynamic performances of a power system. First, an output feedback control law is driven with some conditions satisfied, which guarantees the internal stability and robustness against the asymptotically stable external disturbances. Then the control law is implemented using the inverse dynamics of the controlled plant. The inverse dynamics of the controlled plant is identified by an ANN, inverse dynamics neural network (IDNN), off-line. The pole-shifting technique and a scaling factor are introduced for the control system to meet the conditions for internal stability and robustness. The proposed controller is applied to a typical single-machine infinite-bus power system. Simulation results under various operation conditions are given which show that the proposed ...

UK PubMed Central (United Kingdom)

In order to clarify the taxonomic status and to preserve the stability of the species, a neotype is designated for the tuliptree scale: Coccus liriodendri Gmelin (now Toumeyella...Full Text Available

Science.gov (United States)

Health Iran Iraq Landmines Middle East Muslim Outreach Narcotics Nonproliferation North Korea Pakistan Piracy Reconstruction and Stabilization Sudan Trafficking in Persons War...

Science.gov (United States)

... learn more about the thermal stability of InNP2 Me, a sample contained in a previously evacuated tube was heated at 100°C for 13 days. Neither ...

Science.gov (United States)

... lated Reynolds number for separation is too small. Now ... lol (1959). 6.) F.Schultz-Grunow On stability of Couette flow, AGARD- ...

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... coordinates to allow for multisensor fusion, trajectory ... of an image processing toolkit (iPTK ... effectiveness of data-driven registration processing, spatial ...

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Short communication

Energy Technology Data Exchange (ETDEWEB)

This paper presents a new method for simultaneously selecting the power system stabilizer (PSS) parameters in multimachine power systems. Design of local output feedback power system stabilizer using local signal of the generator (e.g. speed or power) is formulated as a decentralized modal control (DMC) problem. Exact model reduction based on modal control theory is proposed to make the determination of PSS parameters highly efficient. Results obtained from the coordinated tuning of the parameters of three power system stabilizers equipped on a multimachine power system show that exact assignment of the eigenvalues associated with the poorly damped electromechanical modes can be achieved in a very efficient manner.

Science.gov (United States)

allowed an initial assessment of ADS-33 handling quality requirements for an aircraft of this ...... then executing 180 or 360 degree turns in an attempt to ...

Science.gov (United States)

... 5.9-585/T; thermal stability; solubility in liquid nitrogen, oxygen and Freons; molar extinction coefficients in the visible range and EPR spectrum. ...

Energy Technology Data Exchange (ETDEWEB)

This paper deals with a robust H{sub -} power system stabilizer (HPSS) design using reduced-order models to improve the damping oscillation in power systems. The stabilizer is dynamic, low order and robust. In order to obtain a reduced-order controller, the method of balanced truncation is used. Sufficient conditions in the form of two algebraic Riccati equations (AREs) and an upper bound explicitly characterize an H{sub -} controller of lower dimensions. Furthermore, the bilinear transformation has been used to the design to prevent the pole-zero cancellation of the poorly damped poles and to improve the control system performance. The proposed technique is illustrated with applications to the design of stabilizer for a multi-machine power system. Simulation results under various operation conditions are given which show that the proposed HPSS damps the low-frequency oscillation in an efficient manner. (author)

Science.gov (United States)

May 31, 2011 ... A Theoretical Solid Oxide Fuel Cell Model for System Controls and Stability Design AUTHOR(S): Kopasakis, George; Brinson, Thomas; Credle, ...

Energy Technology Data Exchange (ETDEWEB)

About ten years ago microbiologically influenced corrosion manifested on stainless steel pipes used with river water for cooling a chemical plant. The pipe material was similar to Type 316 L. After only six weeks of operation pinhole leaks occurred nearly simultaneously at several welded joints of the pipe. The material degradation was simulated in laboratory and field corrosion tests. Microbiologically influenced corrosion failures also appeared on the pipes of a tubular heat exchanger of duplex steel Type 31803 and on carbon and stainless steel pipes in industrial waste water purification plants after these plants had been modernized with a biological purification unit. The basics of microbiologically influenced corrosion phenomena and typical corrosion failures of pipes will be described. (orig.) [German] Vor etwa zehn Jahren sind in einer neu errichteten chemischen Produktionsanlage an einer mit Flusswasser beaufschlagten Kuehlwasserleitung aus hochlegiertem ...

Energy Technology Data Exchange (ETDEWEB)

In situ scanning tunneling microscopy has been used to study the nucleation and growth mechanisms and the structure of passive films formed on Cu(111) surfaces in 0.1 M borate buffer solution (pH 9.3). A surface topography characterized by terraces with monoatomic steps is obtained after potentiodynamic reduction down to {minus}1.12 V/standard hydrogen electrode (SHE), of the electropolished surface exposed to air. The formation of a single Cu{sub 2}O passive layer at 0.03 V/SHE proceeds first by a roughening of the steps assigned to a locally blocked step flow process due to a competition between dissolution and preferential nucleation of the oxide at the steps. The observed oxide nuclei are 2--3 nm wide and about one atomic plane high. This process leads to the complete coverage of the terraces by a grain-like structure of the oxide film. The initial terrace topography is completely altered. Thickening of this oxide layer leads to unstable scanning tunneling microscope imaging, ...

Energy Technology Data Exchange (ETDEWEB)

Alloy 600 is commonly used in the primary systems of PWR plants because of its excellent resistance to a stress corrosion cracking and pitting. But a stress corrosion cracking and pitting corrosion are occasionally observed under PWR conditions, which may be correlated with the passive film on the Alloy 600 surface. There is little information on the composition of films growing on the surface of Alloy 600 at high temperature. Therefore, an understanding of the basic electrochemical behaviors about an anodic dissolution and the passivation of the bare surface of metals and alloys provides important information about localized corrosions like a SCC and pitting. Oxide on the steel surfaces in an aqueous solution above 100 .deg. C is composed of a duplex film structure. The inner layer of the oxide is dense and less porous, which is formed by a growth of the oxide layer on the metal surface. Outer layer of the oxide is less adhesive, which is formed by a dissolution ...

International Nuclear Information System (INIS)

The helicase action of the Escherichia coli UvrAB complex on a covalently closed circular DNA template was monitored using bacterial DNA topoisomerase I, which specifically removes negative supercoils. In the presence of E. coli DNA topoisomerase I and ATP, the UvrAB complex gradually introduced positive supercoils into the input relaxed plasmid DNA template. Positive supercoils were not produced when E. coli DNA topoisomerase I was replaced by eukaryotic DNA topoisomerase I or when both E. coli and eukaryotic DNA topoisomerases I were added simultaneously. These results suggest that like other DNA helix-tracking processes, the ATP-dependent action of the UvrAM complex on duplex DNA simultaneously generates both positive and negative supercoils, which are not constrained by protein binding but are torsionally strained. The supercoiling activity of UvrAB on UV-damaged DNA was also studied using UV-damaged plasmid DNA and a mutant UvrA protein that lacks the 40 ...

International Nuclear Information System (INIS)

Alloy 690 and Alloy600 are used as a material for the steam generator tubing in the pressurized water reactor(PWR) of nuclear power plants due to its high corrosion resistance. Although those are a highly corrosion resistance material, their stress corrosion cracking(SCC) have been found on occasion, which are deeply related to a surface oxide film on a base material which have occurred on the primary side as well as the secondary side of a tubing. And The SCC is accelerated in the existing Pb which is the impurity of secondary steam generator components. The Oxide on a steel surface in an aqueous solution above 100 .deg. C is composed of a duplex film structure. The inner layer of the oxide is dense and less porous, which is formed by a growth of the oxide layer on the metal surface. The outer layer of the oxide is less adhesive, which is formed by a dissolution and precipitation mechanism. Growth processes of the inner layer and the outer layer occur at the ...

UK PubMed Central (United Kingdom)

BackgroundThe association between infertility and sperm disomy is well documented. Results vary but most report that men with severely compromised semen parameters have a significantly...Full Text Available

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We investigate the possibility of observing strong interactions of longitudinally polarized weak vector bosons in the process {gamma}{gamma}{yields}ZZ at a photon linear collider. We make use of polarization of the photon beams and cuts on the decay products of the Z bosons to enhance the signal relative to the background of transversely polarized ZZ pairs. We find that the background overwhelms the signal unless there are strong resonant effects, as for instance from a technicolor analogue of the hadronic f{sub 2}(1270) meson. ((orig.)).

CERN Document Server

I report on a lattice computation of the energy of a system of two light quarks and two static antiquarks as a function of the separation of the static antiquarks. In terms of hadrons such a system corresponds to a pair of B mesons and its energy to the hadronic potential. I present selected results for different isospin, spin and parity combinations of the individual B mesons mainly focusing on those channels relevant to determine, whether two B mesons may form a bound tetraquark state.

Science.gov (United States)

Testosterone has bipotential effects on male fitness; that is, it both suppresses immune function and maintains characteristics important for reproductive success. Presumably, these effects of testosterone may be more pronounced among polygynous species because testosterone concentrations are generally higher among polygynous than monogamous males. The present study examined sex and species differences in cell-mediated immunity among four arvicoline rodents. The role of mating system and sex steroids in sex differences in immune function was examined in individually housed polygynous meadow (Microtus pennsylvanicus) and montane (M. montanus) voles and monogamous prairie (M. ochrogaster) and pine (M. pinetorum) voles in Experiment 1. No sex differences in splenocyte proliferation were observed among the four species and circulating testosterone concentrations did not correlate with immune function of individuals within each species. The contribution of social isolation to these results ...

International Nuclear Information System (INIS)

Radial distribution functions of liquid sodium and caesium at 100"0C have been calculated by the method of molecular dynamics with interionic pair potentials derived from Heine-Abarenkov-Shaw type model potential. The results were found to be in good agreement with recent experimental data. (Auth.).

International Nuclear Information System (INIS)

The heavy neutral Higgs bosons H, A in the minimal supersymmetric extension of the standard model can be produced as single resonances at high-energy #gamma##gamma# colliders. We have studied the prospects of the search for these particles in bb and neutralino-pair final states. The Higgs bosons can be found with masses up to 70-80% of the initial e"#+-#e"- collider energy for medium values of tg#beta#, i.e. in areas of the supersymmetric parameter space not accessible at other colliders. (orig.)

International Nuclear Information System (INIS)

Future #gamma##gamma# colliders allow the production of the heavy neutral MSSM Higgs bosons H and A as single resonances. The prospects of finding these particles in the bb-bar and the neutralino-pair final states have been analyzed. The H, A bosons can be discovered for medium values of tan #beta# with masses up to 70-80% of the initial e"#+-#e"- c.m. energy. This production mode thus covers parts of the supersymmetric parameter space that are not accessible at other colliders.

International Nuclear Information System (INIS)

The basics of a supersymmetric SU(2)_L x SU(2)_R x U(1)_B-I, model are reviewed. The production and subsequent decays of the doubly charged triplet higgsino #DELTA##+-##+-# in the Next Linear Collider are discussed. The slepton pair production in the framework of this model is also analyzed. (author)

Energy Technology Data Exchange (ETDEWEB)

A model for generating the observed cosmic-ray antiproton spectrum in plasma consisting mainly of electron--positron pairs (n/sub plus-or-minus//n/sub p/> or approx. =10) is discussed. Coulomb collisions in the plasma would cause additional energy losses, significantly enhancing the antiproton flux at energies < or approx. =1 GeV. The computed p-bar/p ratio satisfactorily fits the observations.

CERN Document Server

In this paper, we show how to calculate analytically the one-loop helicity amplitudes for the process $q\\bar{q} rightarrow t\\bar{t}$ induced by KK gluon, using the spinor-helicity formalism. A minimal set of Feynman rules which are uniquely fixed by gauge invariance and the color representation of the KK gluon are derived and used in the calculation. Our results can be applied to a variety of models containing a massive color octet vector boson.

Energy Technology Data Exchange (ETDEWEB)

A model of formation of cosmic ray antiproton spectrum in plasma consisting mainly of electron-positron pairs (nsub(+-)/nsub(p) > or approximately 10) is considered. Additional energy losses due to Coulomb collisions in plasma provide significant increase of the antiproton flux in the energy range < or approximately 1 GeV. Calculated anti p/p ratio is in a satisfactory agreement with the observational data.

International Nuclear Information System (INIS)

Muon captures by nucleon pairs via meson-exchange currents produce a high energy excitation tail in heavy nuclei. The muon induced fission by these excitations is calculated in several subactinide nuclei with high threshold fission barriers. The probability for delayed fission ranges from 4 x 10"-"5 to 4 x 10"-"3 for the isotopes considered. (orig.).

International Nuclear Information System (INIS)

It is proposed to measure the spot sizes and polarization of #gamma# beams of future #gamma#e and #gamma##gamma# colliders detecting e"+e"- pairs produced as a result of interaction of high energy #gamma# quanta with density modulated and not modulated laser photons. The quantum electrodynamics cross sections, necessary numerical results as well as a short comparison of the proposed method with some other methods are given. (orig.).

Energy Technology Data Exchange (ETDEWEB)

In the present paper, a possible interaction region layout of the VLEPP based Photon Linear Collider (PLC) with ultimate luminosity is discussed. In order to remove spent electron beams, the crab-crossing scheme is used. The detector is protected from produced pairs and secondary particles by means of the detector magnetic field and a shielding mask. ((orig.)).

Energy Technology Data Exchange (ETDEWEB)

The hierarchy of integrable nonlinear equations associated with the quadratic bundle is considered. The expressions for the solution of linearization of these equations and their conservation law in the terms of solutions of corresponding Lax pairs are found. It is shown for the first member of the hierarchy that the conservation law is connected with the solution of linearized equation due to the Noether's theorem. The local hierarchy and three nonlocal ones of the infinitesimal symmetries and conservation laws explicitly expressed through the variables of the nonlinear equations are derived. (author)

International Nuclear Information System (INIS)

A length of metal sheathed metal oxide cable is perforated to permit liquid access to the insulation about a pair of conductors spaced close to one another. Changes in resistance across the conductors will be a function of liquid level, since the wetted insulation will have greater electrical conductivity than that of the dry insulation above the liquid elevation.

International Nuclear Information System (INIS)

A patent is claimed for the invention of a hardening (ionizing radiation resistance) process for MOS type components and CMOS or bipolar type components. The ionizing radiation effect on those systems is the electron-hole pair production, which induces interference phenomena. The MOS main structure is successively composed of a silicon substrate layer, a layer of an irradiation resistant material and a layer of partially monocrystalline silicon.

UK PubMed Central (United Kingdom)

A total of 172 persons from nine South Amerindian, three African and one Eskimo populations were studied in relation to the Paired box gene 9 (PAX9) exon 3 (138 base...Full Text Available

CERN Document Server

We propose a scheme able to generate stationary continuous variable entanglement between an optical and a microwave cavity mode by means of their common interaction with a micro-mechanical resonator. We show that when both cavities are intensely driven one can generate bipartite entanglement between any pair of the tripartite system, and that, due to entanglement sharing, optical-microwave entanglement is efficiently generated at the expense of microwave-mechanical and opto-mechanical entanglement.