WorldWideScience
1

Algebraic Structure of Linear Dynamical Systems. III. Realization Theory Over a Commutative Ring  

UK PubMed Central (United Kingdom)

The realization theory linear dynamical systems, previously developed over a field, are extended to a large class of commutative rings. The principal result is that the existence criterion for a finite...Full Text Available

1972-11-01

2

Cyclopeptide alkaloids. Synthesis of the ring system and its ion affinity  

International Nuclear Information System (INIS)

Several examples of the 14-membered, para-bridged ring system of the cyclopeptide alkaloids have been synthesized via an active ester cyclization. The yield of monomeric cyclopeptide varied from 1 to 33% and was affected by the amino acid substitution pattern and amide conformation of the linear peptide precursors. Both the synthetic models and a naturally occurring cyclopeptide alkaloid, ceanothine B, bind monovalent (Li"+) and divalent (Ca"2"+, Mg"2"+) cations. 4 figures, 1 table.

3

Method for syndrome coding and its application to fast hardware data selection based on the processors operating in the GF(2sup(m)) Galois field  

International Nuclear Information System (INIS)

The method of syndrome coding for data compression read out from multiwire proportional chambers that has been previously proposed is generalized in case of its application to registration of the coordinates of events detected. The questions of execution of arithmetic and algebraic operations on the Galois field elements and their hardware implementation are considered. The method of computation is presented of a specialized processor for parallel computing the coordinates of three sparks. The estimate of its speed is equal to 185 ns. Data compression, data selection and coordinate calculations are performed without use of memory elements and timing pulses.

4

On the bending response of Kevlar 49/epoxy beams and rings  

Energy Technology Data Exchange (ETDEWEB)

Kevlar 49/epoxy laminates often exhibit substantial material nonlinearity when subjected to bending. This is a consequence of the yeild-like behavior of a Kevlar 49/epoxy lamina in fiber-directed compression. In this paper, analyses that utilize a simple idealization of compressive yielding are described and calculated results for Kevlar 49 reinforced beams and rings are compared with available data. First, results of a finite element analysis of a thin, unidirectionally reinforced ring subjected to diametral compression are presented. This analysis uses beam elements that incorporate linear tensile and elastic-perfectly plastic compressive behavior. Then a method used to analyze quasi-isotropic beams tested in four-point bending is discussed. This finite element analysis uses a layered shell element with a lamina constitutive model that permits elastic-perfectly plastic response to fiber-directed compression, but otherwise ...

1988-05-01

5

Free relations for matrix invariants in the modular case  

British Library Electronic Table of Contents (United Kingdom)

A classical linear group GJ between the graded ring S= d=0^~Sd, where Sd is the character group of the symmetric group Sd, and the inverse limit J with respect to n of rings of symmetric polynomials in n variables. As a consequence, we complete the description of relations between generators for O(n)-invariants as well as the description of relations for invariants of mixed representations of quivers. We also obtain an independent proof of the result that the ideal of free relations for GL(n)-invariants is zero, which was proved by Donkin in [S. Donkin, Invariant functions on matrices, Math. Proc. Cambridge Philos. Soc. 113 (1993) 23-43].

2012-01-01

6

Nuclei with protrusions - tailed nuclei - and radiation cytogenetic markers in X-irradiated lymphocytes in vitro  

International Nuclear Information System (INIS)

The results of an investigation into tailed nuclei (TN) and features of dose dependence on frequency of the binuclear cells with TN in human lymphocyte cultures by cytogenetic block method upon X-ray radiation dose are presented. The frequencies of metaphases with dicentric and ring chromosomes are investigated concurrent with TN formed upon completion of first postradiation mitosis. Frequency of the appearance of binuclear cells with nuclei having outgrowth into the cytoplasmic space and arises after first mitosis in human lymphocyte culture is linear-square dependent on the X-irradiation at doses from 0.0 to 4.0 Gy. Positive correlation between frequency of cells with tailed nuclei and frequency of metaphases of first mitosis having dicentric and rings was established. Apparently, formation such TN is connected with dicentric and rings

7

Damping Ring to Interaction Point Beam Transport Issues  

CERN Document Server

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

2003-01-01

8

Van Der Pol model of a Cerenkov maser  

Energy Technology Data Exchange (ETDEWEB)

A non-linear analysis of a Cerenkov maser is presented. The system consists of a ring configuration of a cylindrical waveguide filled with a dielectric material. A single transverse-magnetic mode is assumed to propagate in the system. A low-density pencil electron beam travels in part of the ring, confined by a strong axial magnetic field. Using the single-particle description for the beam and the wave equation for the field, we obtain a set of two coupled non-linear differential equations describing the slowly varying amplitude and phase of the electromagnetic mode. The gain per path is assumed to be small and the spatial growth of the field is neglected. The resulting time dependent amplitude includes the exponential gain of the linear stage and the saturation to its maximum value. The time dependent frequency is also calculated. The two equations are combined to a single Van Der ...

1995-12-31

9

Damping the. pi. -mode instability in the SLC damping rings with a passive cavity  

Energy Technology Data Exchange (ETDEWEB)

Operating the Stanford Linear Collider (SLC) at 120Hz repetition rate requires the presence of two bunches in both the electron and the positron damping ring. The {pi}-mode instability, a coupled bunch instability where the two bunches oscillate with a phase difference of 180{degrees}, had been observed in both rings with low current thresholds of 7{sup *}10{sup 9} particles per bunch. To avoid the instability, the RF system had to be operated in ways which in general reduced the cavity gap voltages and required constant operational attention. For the 1992 running cycle a passive cavity was installed and successfully tested. It is tuned to the frequency of the lower synchrotron oscillation sideband of an odd revolution harmonic. The impedance of the cavity then damps {pi}-mode oscillations very similar to the Robinson damping provided by the main RF cavities which damps O-mode synchrotron oscillations. In this report we ...

1992-07-01

10

Damping the {pi}-mode instability in the SLC damping rings with a passive cavity  

Energy Technology Data Exchange (ETDEWEB)

Operating the Stanford Linear Collider (SLC) at 120Hz repetition rate requires the presence of two bunches in both the electron and the positron damping ring. The {pi}-mode instability, a coupled bunch instability where the two bunches oscillate with a phase difference of 180{degrees}, had been observed in both rings with low current thresholds of 7{sup *}10{sup 9} particles per bunch. To avoid the instability, the RF system had to be operated in ways which in general reduced the cavity gap voltages and required constant operational attention. For the 1992 running cycle a passive cavity was installed and successfully tested. It is tuned to the frequency of the lower synchrotron oscillation sideband of an odd revolution harmonic. The impedance of the cavity then damps {pi}-mode oscillations very similar to the Robinson damping provided by the main RF cavities which damps O-mode synchrotron oscillations. In this report we ...

1992-07-01

11

Rank functions and partial stability spectra for tame AECs  

CERN Document Server

We introduce a family of rank functions and related notions of total transcendence for Galois types in abstract elementary classes. We focus, in particular, on abstract elementary classes satisfying the condition know as tameness (currently suspected to be a necessary condition for the development of a reasonable classification theory) where the connections between stability and total transcendence are most evident. As a byproduct, we obtain a partial upward stability transfer result for tame abstract elementary classes stable in a cardinal lambda satisfying lambda^{aleph_0}, a substantial generalization of a result of Baldwin, Kueker, and VanDieren.

2010-01-01

12

Operating Characteristics of a Three-Piece-Inner-Ring Large-Bore ...  

Science.gov (United States)

roller bearing with a one-piece inner ring. The lubricant experimental data on high-speed roller .... roller bearing. The outer ring of the test bearing was ...

14

Simulation study of feedback systems based on a two-tap FIR filter. Under beam-beam collisions  

Energy Technology Data Exchange (ETDEWEB)

The performance of bunch-feedback systems based on two-tap FIR filters is discussed, particularly for transverse cases. Since they are the simplest type of FIR digital filters, the two-tap FIR filters should be suited to systems that require a very fast processing speed. However, in these feedback systems, a bunch must turn along a ring several times from the position-measurement to feedback kicking. Within these turns, irregular phase-jumps in the betatron motion can occur, due to several causes, such as the wake forces and beam-beam force. The discussion given in this paper is focussed on the effect of beam-beam collisions on these feedback systems. Based on linear theory and simulation studies, it has been found that these feedback systems can work with good performance, even under the influence of a strong beam-beam force. (author)

1998-04-01

15

Secondary electron yield measurements from thin surface coatings for NLC electron cloud reduction  

CERN Document Server

In the beam pipe of the positron damping ring of the Next Linear Collider, electrons will be created by beam interaction with the surrounding vacuum chamber wall and give rise to an electron cloud. Several solutions are possible for avoiding the electron cloud, without changing the bunch structure or the diameter of the vacuum chamber. Some of the currently available solutions for preventing this spurious electron load include reducing residual gas ionization by the beam, minimizing beam photon-induced electron production, and lowering the secondary electron yield (SEY) of the chamber wall. We will report on recent SEY measurements performed at SLAC on TiN coatings and TiZrV non-evaporable getter thin films.

2004-01-01

16

Photodegradation of flupentixol in aqueous solution under irradiation at 254nm: Identification of the photoproducts generated  

British Library Electronic Table of Contents (United Kingdom)

After irradiation at 254nm of aqueous solutions of the antipsychotic drug flupentixol, the structures of the photodegradation products were determined by ultra high performance liquid-chromatography linked to mass spectrometry. Fragmentation patterns of the parent ions were established on a hybrid linear ion trap-orbitrap mass spectrometer allowing accurate mass measurements of both parent and daughter ions. This allowed to propose plausible structures for the main photolysis products of flupentixol. A total of nine photoproducts were detected after irradiation of the drug. The main photoproduct is generated following the addition of a hydroxyl group on the double bond adjacent to the thioxanthene ring. Secondary photoproducts were also observed.

2010-01-01

17

Linac automated beam phase control system.  

Energy Technology Data Exchange (ETDEWEB)

Adjustment of the rf phase in a linear accelerator is crucial for maintaining optimal performance. If phasing is incorrect, the beam will in general have an energy error and increased energy spread. While an energy error can be readily detected and corrected using position readings from beam position monitors at dispersion locations, this is not helpful for correcting energy spread in a system with many possible phase errors. Uncorrected energy spread results in poor capture efficiency in downstream accelerators, such as the Advanced Photon Source's (APS's) particle accumulator ring (PAR) or booster synchrotron. To address this issue, APS has implemented beam-to-rf phase detectors in the linac, along with software for automatic correction of phase errors. We discuss the design, implementation, and performance of these detectors and how they improved APS top-up operations.

2006-01-01

18

Activities on free electron laser in Japan  

International Nuclear Information System (INIS)

The free-electron laser (FEL) projects that are currently in progress in Japan are discussed. Particular attention is given to the storage ring FELs at the Electrotechnical Laboratory, the Institute for Molecular Physics, and the Kyushu University; the superconducting linear accelerator (SC linac) FELs being developed at the Japan Atomic Energy Research Institute; and the RF-linac FEL being developed by the Nuclear Engineering Research Laboratory of the University of Tokyo, the Institute of Scientific and Industrial Research of Osaka University, the Mitsubishi Electric Company, and Tokyo Institute of Technology. Consideration is also given to the microtron FEL being constructed at the Nihon University; the induction-linac and pulseline FELs of the Institute of Laser Engineering of Osaka University, the Institute of Physical and Chemical Research, the National Laboratory for High-Energy Physics, and ISAS; and the Smith-Purcell-effect FEL ...

1989-04-24

19

Saturn's Recycling Rings - Cassini Solstice Mission - NASA  

Science.gov (United States)

Dec 12, 2007 ... This is an artist concept of a close-up view of Saturn's ring particles.

20

Alternative Loop Rings  

CERN Document Server

For the past ten years, alternative loop rings have intrigued mathematicians from a wide cross-section of modern algebra. As a consequence, the theory of alternative loop rings has grown tremendously. One of the main developments is the complete characterization of loops which have an alternative but not associative, loop ring. Furthermore, there is a very close relationship between the algebraic structures of loop rings and of group rings over 2-groups. Another major topic of research is the study of the unit loop of the integral loop ring. Here the interaction between loop rings and group ri

1996-01-01

21

Synthesis and crystal structure of a new open-framework iron phosphate (NH4)4Fe3(OH)2F2[H3(PO4)4]: Novel linear trimer of corner-sharing Fe(III) octahedra  

International Nuclear Information System (INIS)

A new iron phosphate (NH4)4Fe3(OH)2F2[H3(PO4)4] has been synthesized hydrothermally at HF concentrations from 0.5 to 1.2 mL. Single-crystal X-ray diffraction analysis reveals its three-dimensional open-framework structure (monoclinic, space group P21/n (No. 14), a=6.2614(13) A, b=9.844(2) A, c=14.271(3) A, ?=92.11(1)o, V=879.0(3) A3). This structure is built from isolated linear trimers of corner-sharing Fe(III) octahedra, which are linked by (PO4) groups to form ten-membered-ring channels along [1 0 0]. This isolated, linear trimer of corner-sharing Fe(III) octahedra, [(FeO4)3(OH)2F2], is new and adds to the diverse linkages of Fe polyhedra as secondary building units in iron phosphates. The trivalent iron at octahedral sites for the title compound has been confirmed by synchrotron Fe K-edge XANES spectra and magnetic measurements. Magnetic measurements also show that this compound exhibit a strong antiferromagnetic ...

2010-12-01

22

Accelerator technology program. Progress report, April-December 1978  

Science.gov (United States)

This report presents highlights of activities in the Acceleartor Technology (AT) Division from April through December 1978. The report is divided into 10 sections to cover work done by the four groups that make up AT Division (AT-1, AT-2, AT-3, and AT-4). Section I is a brief summary of the whole report. Sections II through VI describe work done by At-1, the Linac Technology Group. Subjects covered are the Pion Generation for Medical Irradiation Program, the Electronuclear Fuel-Producing Accelerator Program, the Gyrocon rf Amplifier Program, the Electron Linear Accelerator Program, and the Free Electron Laser Program. Section VII covers the Linear Accelerator Beam Dynamics development, and Sec. VIII deals with work with the H/sup -/ Ion Source. Most of the work in Secs. VII and VIII was done by AT-2, the Special Projects Group, although work on factors influencing emittance growth was done by MP-9, and results on emittance growth in the new ...

1980-05-01

23

JHK and 3.3um PAH Imaging of the Starburst Ring in the Type I Seyfert Galaxy NGC 7469  

Science.gov (United States)

Imaging of NGC 7469 in the J, H, & K bands shows that the starburst 'ring' is a tight inner

1993-01-01

24

Wear and friction coefficient of particle reinforced Ti-alloys  

Energy Technology Data Exchange (ETDEWEB)

Particulate Reinforced Titanium matrix composites (PRTi) exhibit some improved specific mechanical properties in comparison with those of unreinforced titanium alloys as a result of the combination of the high strength and stiffness of ceramic particles with the toughness and damage tolerance provided by the metal matrix. The poor tribological properties of the titanium exclude titanium alloys from applications where wear resistance is required (brakes, rotating parts, sliding parts). The addition of ceramic particles improves the tribological properties of metals sensitive to adhesive and /or abrasive wear significantly. In this work, the wear resistance and the friction coefficient of Ti6Al-6V-2Sn reinforced with TiC particles and Ti6Al-4V reinforced with SiC particles (prototype material) are compared with the unreinforced alloys. Pin on disc and pin on ring tests were carried out against standard steel (100Cr6) as a function of pressure, speed and temperature. ...

2004-11-01

25

On mutually unbiased bases  

CERN Document Server

Mutually unbiased bases for quantum degrees of freedom are central to all theoretical investigations and practical exploitations of complementary properties. Much is known about mutually unbiased bases, but there are also a fair number of important questions that have not been answered in full as yet. In particular, one can find maximal sets of ${N+1}$ mutually unbiased bases in Hilbert spaces of prime-power dimension ${N=p^\\m}$, with $p$ prime and $\\m$ a positive integer, and there is a continuum of mutually unbiased bases for a continuous degree of freedom, such as motion along a line. But not a single example of a maximal set is known if the dimension is another composite number ($N=6,10,12,...$). In this review, we present a unified approach in which the basis states are labeled by numbers ${0,1,2,...,N-1}$ that are both elements of a Galois field and ordinary integers. This dual nature permits a compact systematic construction of maximal sets of mutually ...

2010-01-01

26

Cerenkov ring imaging and spectroscopy of charged KSTAR interactions at 11 GeV/c  

Energy Technology Data Exchange (ETDEWEB)

The physics and technology of this new Cerenkov detector are discussed, including materials studies, construction techniques, and resolution measurements. Sources of resolution error are individually identified and measured where possible. The results of all studied indicate that the measurement resolution is understood. This work has led to the adoption of a large scale ring imaging detector as part of a new high energy physics spectrometer, the SLD, at the Stanford Linear Accelerator Center. Results from an amplitude analysis of strange meson final states in K/sup /minus//p ..-->.. /ovr K/sub 0//..pi../sup /minus//p interactions are presented. The data derive from a 4 event/nb exposure of the LASS (large Aperture Superconducting Solenoid) spectrometer to an 11 GeV/c K/sup /minus// beam. The data sample consists of /approximately/100,000 vents distributed over the Dalitz plot of the channel. The process is observed to be dominated by the ...

1988-11-01

27

Stability study of a gyrotron-traveling-wave amplifier based on a lossy dielectric-loaded mode-selective circuit  

Science.gov (United States)

The millimeter microwave source of gyrotron-traveling-wave amplifier (gyro-TWT) is capable of generating high power coherent radiation in a broad bandwidth, while its performance is severely deteriorated by the stability problems. This paper focuses on modeling and the stability analysis of the Naval Research Laboratory (NRL) Ka-band TE{sub 01} mode gyro-TWT based on an interaction circuit alternately loaded with lossy ceramic shells and metal rings. The propagation characteristics of the interaction circuit is analyzed first, based on which the boundary impedance method is employed to build an equivalent uniform lossy circuit. Then the stability of the interaction system is studied using linear and nonlinear theories. The analysis reveals that, due to the special waveguide structure and the dielectric loss, the propagation characteristics of the complex waveguide are similar to that of a uniform lossy circuit. The analysis of the absolute ...

2009-07-15

28

Stability study of a gyrotron-traveling-wave amplifier based on a lossy dielectric-loaded mode-selective circuit  

International Nuclear Information System (INIS)

The millimeter microwave source of gyrotron-traveling-wave amplifier (gyro-TWT) is capable of generating high power coherent radiation in a broad bandwidth, while its performance is severely deteriorated by the stability problems. This paper focuses on modeling and the stability analysis of the Naval Research Laboratory (NRL) Ka-band TE01 mode gyro-TWT based on an interaction circuit alternately loaded with lossy ceramic shells and metal rings. The propagation characteristics of the interaction circuit is analyzed first, based on which the boundary impedance method is employed to build an equivalent uniform lossy circuit. Then the stability of the interaction system is studied using linear and nonlinear theories. The analysis reveals that, due to the special waveguide structure and the dielectric loss, the propagation characteristics of the complex waveguide are similar to that of a uniform lossy circuit. The analysis of the absolute ...

2009-07-01

29

Particle physics -- Future directions  

Energy Technology Data Exchange (ETDEWEB)

Wonderful opportunities await particle physics over the next decade, with the coming of the Large Hadron Collider at CERN to explore the 1-TeV scale (extending efforts at LEP and the Tevatron to unravel the nature of electroweak symmetry breaking) and many initiatives to develop our understanding of the problem of identity: what makes a neutrino a neutrino and a top quark a top quark. Here I have in mind the work of the B factories and the Tevatron collider on CP violation and the weak interactions of the b quark; the wonderfully sensitive experiments at Brookhaven, CERN, Fermilab, and Frascati on CP violation and rare decays of kaons; the prospect of definitive accelerator experiments on neutrino oscillations and the nature of the neutrinos; and a host of new experiments on the sensitivity frontier. We might even learn to read experiment for clues about the dimensionality of spacetime. If we are inventive enough, we may be able to follow this rich menu with the physics opportunities ...

2001-11-29

30

Free electron laser and accelerator  

International Nuclear Information System (INIS)

The present report addresses several aspects of the free electron laser (FEL) and accelerator, including their features, potentials, mechanisms, beams emitted from undulator, FEL produced by helical mangnetic field, major problems with FEL, etc. In FEL, relativistic electron beams interact with an electromagnetic field with periodically changing intensity to produce coherent electromagnetic waves with variable wavelength. The capability of varying its wavelength represents the greatest advantage over conventional lasers. Any periodic magnetic field can serve as a wiggler. A wiggler can be used both in an amplifier and oscillator. A periodic magnetic field used may be either of a parallel type or of a helical type. The polarization of emitted beams depends on the shape of the magnet regardless of whether its field is parallel or helical. An equation is derived in the report which expresses the wavelength of an electromagnetic wave produced by an undulator. An analysis is made of FEL ...

1988-08-01

34

Inner ring structures in galaxies as distance indicators. I. Dimensionless systematics of inner rings  

International Nuclear Information System (INIS)

Inner ring structures are observed in about one quarter of all lenticular or spiral galaxies. Statistics of the relative frequencies of the pure ring (r) and broken ring (rs) varieties in the Second Reference Catalogue (RC2) among the different families (A, AB, B) of lenticular (L) and spiral (S) galaxies at different stages (T) along the revised Hubble sequence are presented; selection effects dependent on classification weight, apparent diameter and axis ratio are discussed. Comparisons of ring diameters D/sub r/ listed in the (First) Reference Catalogue (RC1) with independent measurements of 43 barred systems by Kormendy show good systematic agreement with a standard deviation sigma_1_2(D/sub r/) = 0'.10 and individual relative mean errors sigma(D/sub r/)/ < D/sub r/ > approx. = 5%. Axis ratios are also in good agreement with sigma_1_2(b/a) = 0.06. Comparisons of axis ratios of ...

36

Studies of accelerated compact toruses  

Energy Technology Data Exchange (ETDEWEB)

In an earlier publication we considered acceleration of plasma rings (Compact Torus). Several possible accelerator configurations were suggested and the possibility of focusing the accelerated rings was discussed. In this paper we consider one scheme, acceleration of a ring between coaxial electrodes by a B/sub theta/ field as in a coaxial rail-gun. If the electrodes are conical, a ring accelerated towards the apex of the cone undergoes self-similar compression (focusing) during acceleration. Because the allowable acceleration force, F/sub a/ = kappaU/sub m//R where (kappa < 1), increases as R/sup -2/, the accelerating distance for conical electrodes is considerably shortened over that required for coaxial electrodes. In either case, however, since the accelerating flux can expand as the ring moves, most of the accelerating field energy can be converted into kinetic energy of the ...

1983-01-04

37

Stability of the viscously spreading ring  

CERN Document Server

We study analytically and numerically the stability of the pressure-less, viscously spreading accretion ring. We show that the ring is unstable to small non-axisymmetric perturbations. To perform the perturbation analysis of the ring we use a stretching transformation of the time coordinate. We find that to 1st order, one-armed spiral structures, and to 2nd order additionally two-armed spiral features may appear. Furthermore, we identify a dispersion relation determining the instability of the ring. The theoretical results are confirmed in several simulations, using two different numerical methods. These computations prove independently the existence of a secular spiral instability driven by viscosity, which evolves into persisting leading and trailing spiral waves. Our results settle the question whether the spiral structures found in earlier simulations of the spreading ring are ...

2003-01-01

38

COSY synchrotron and storage ring for medium energy physics  

Energy Technology Data Exchange (ETDEWEB)

At present the cooler synchrotron COSY a synchrotron and storage ring for medium energy physics is being commissioned at Juelich. The construction of the ring was finished during September 1992. The cooler ring will deliver protons in the momentum range from 270 to 3300 MeV/c. The phase density of the circulating protons will be increased with electron cooling at injection and with stochastic cooling at momenta between 1500 and 3300 MeV/c. High luminosity internal experiments as well as high resolution external experiments will be possible. Details of the lattice, to match the different ion optical requirements for cooling, acceleration, internal experiments and ultra-slow extraction will be discussed. An overview of the performance of the ion sources, the injector cyclotron, the ring, the injection beamline are given. The realization status of the extraction beamlines to the external experimental area ...

1993-01-01

39

Xylem Embolism in Response to Freeze-Thaw Cycles and Water Stress in Ring-Porous, Diffuse-Porous, and Conifer Species 1  

UK PubMed Central (United Kingdom)

Vulnerability to xylem embolism by freeze-thaw cycles and water stress was quantified in ring-porous (Quercus gambelii Nutt.), diffuse-porous (Populus tremuloides Michx.,...Full Text Available

1992-10-01

40

Ring opening reaction dynamics of a photochromic diarylethene derivative dye  

International Nuclear Information System (INIS)

Ring opening dynamics of diarylethene derivative (BTF6) in n-hexane are studied by femtosecond transient absorption and time resolved spontaneous fluorescence techniques. Cyclo-reversion time constant is obtained.

2001-11-01

41

Resonance Raman enhancement of phenyl ring vibrational modes in phenyl iron complex of myoglobin.  

UK PubMed Central (United Kingdom)

Resonance Raman spectra are reported for the organometallic phenyl-FeIII complexes of horse heart myoglobin. We observed the resonance enhancement of the ring vibrational modes of the bound phenyl group....Full Text Available

1990-04-01

42

Proton storage ring (PSR) diagnostics and control system  

Energy Technology Data Exchange (ETDEWEB)

When any new accelerator or storage ring is built that advances the state of the art, the diagnostic system becomes extremely important in tuning the facility to full specification. This paper will discuss the various diagnostic devices planned or under construction for the PSR and their connection into the control system.

1983-01-01

43

Electron Flux - 8.0 keV - ISWA wiki - ISWA - NASA  

Science.gov (United States)

Nov 14, 2009 ... Ring Current electrons from the Fok Ring Current Model are computed using plasma and magnetic field values from the SWMF magnetosphere ...

44

Electron Flux - 4.7 keV - ISWA wiki - NASA  

Science.gov (United States)

Nov 14, 2009 ... Ring Current electrons from the Fok Ring Current Model are computed using plasma and magnetic field values from the SWMF magnetosphere ...

45

Electron Flux - 179 keV - ISWA wiki - ISWA - NASA  

Science.gov (United States)

Nov 14, 2009 ... Ring Current electrons from the Fok Ring Current Model are computed using plasma and magnetic field values from the SWMF magnetosphere ...

46

Gunsof - NASA  

Science.gov (United States)

end of the barrel. The petal valve and ring seal are inserted behind it, and the gun barrel assembly and HP section are clamped together with hydraulic collars. ...

47

FINITE ELEMENT OPTIMIZATION OF FIELD ...  

Science.gov (United States)

... Title : FINITE ELEMENT OPTIMIZATION OF FIELD CONFIGURATION FOR THE EDDY CURRENT TESTING OF ROLLER BEARING RIB RINGS. ...

1988-04-01

48

Developing methods for testing and monitoring packing, detachable connections used in well geophysical apparatus. O razrabotke metodov ispytaniy i kontrolya uplotnitel'nykh raz''yemnykh soyedineniy, primenyayemykh v skvazhinnoy geofizicheskoy apparature  

Energy Technology Data Exchange (ETDEWEB)

Development of surface monitoring of the quality of round rubber packing rings for well instruments is discussed. A method is shown for testing the rings under conditions which simulate the operating conditions. A method is proposed for rapid monitoring of the conditions for vulcanization of the rings by the method of determining the ''ring modulus.''

1983-01-01

49

Tunable erbium-doped fiber ring laser for applications of infrared absorption spectroscopy  

British Library Electronic Table of Contents (United Kingdom)

We fabricate a low noise erbium-doped fiber ring laser that can be continuously tuned over 102nm by insertion of the fiber Fabry-Perot tunable filter (FFP-TF) in the ring cavity with a novel cavity structure and the optimal gain medium length. As an application of this fiber ring laser, we performed the absorption spectroscopy of acetylene (13C2H2) and hydrogen cyanide (H13C14N) and measure the absorption spectra of more than 50 transition lines of these gases with an excellent signal to noise ratio (SNR). The pressure broadening coefficients of four acetylene transition lines are obtained using this fiber ring laser and an external cavity laser diode.

2007-01-01

50

Syzygy Theorems via comparison of order ideals on a hypersurface  

British Library Electronic Table of Contents (United Kingdom)

We introduce a weak order ideal property that suffices for establishing the Evans-Griffith Syzygy Theorem. We study this weak order ideal property in settings that allow for comparison between homological algebra over a local ring R versus a hypersurface ring R =R/(x^n). Consequently we solve some relevant cases of the Evans-Griffith syzygy conjecture over local rings of unramified mixed characteristic p, with the case of syzygies of prime ideals of Cohen-Macaulay local rings of unramified mixed characteristic being noted. We reduce the remaining considerations to modules annihilated by p^s, s>0, that have finite projective dimension over a hypersurface ring.

2012-01-01

51

Effect of the repulsive core on the exciton spectrum in a quantum ring  

Energy Technology Data Exchange (ETDEWEB)

A theoretical study of an exciton confined in a quantum ring is presented. The quantum ring is described as a two-dimensional circular quantum dot with a repulsive core, which is modelled with the help of two Gaussian functions. We have applied the variational method and investigated the evolution of the low-energy exciton spectrum with the change of the confinement potential. The calculations have been performed for the recently produced self-assembled ring-shaped InGaAs quantum dots. We have shown that the repulsive core strongly increases the radiative transition probability from the exciton ground state at the expense of the decreasing probability of the transitions from the excited states. This effect results from the orthogonality properties of the exciton wavefunctions, which are specific to the quantum-ring confinement potential. We have studied the characteristic features of the exciton ...

2002-01-14

52

Are the delay images necessary to evaIuate the liver metastatic lesions on mangafodipir trisodium enhanced liver MRI?: comparison with hepatocellular carcinomas  

Energy Technology Data Exchange (ETDEWEB)

To assess whether ring enhancements of liver metastases on Mn-DPDP enhanced, early MR images were well visualized on delayed images, as compared with those of hepatocellular carcinomas (HCC), and to investigate the detection accuracy and conspicuity of each tumor. Twenty patients with liver metastases and 15 with HCC were studied by Mn-DPDP enhanced, T1-weighted MR images. Peripheral ring enhancement and conspicuity were investigated. Differences in detection accuracy and frequency of ring enhancement in liver metastases and HCC were assessed. In liver metastases (n= 69), 44 cases (63.8%) without ring enhancement and 25 (36.2%) with were noted on early images. Sixteen cases (23.2%) without ring enhancement, 38 (55.1%) with ring enhancement similar to the early images, and 15 (21.7%) with prominent ring enhancement were noted on delayed ...

2004-09-01

53

XRF analysis of rock and sediment using standard rock samples  

Energy Technology Data Exchange (ETDEWEB)

A simple and rapid method is described for the determination of major and trace elements in rock and sediment samples by wavelength dispersive XRF. Sample measured were made from cellulose powder pressed into 4 cm diameter aluminium ring 0.4 t cm/sup -2/, and then 1 g of powdered sample (0.08 g cm/sup -2/) was placed on the disk and repressed at 1.6 t cm/sup -2/. X-ray measurements were performed for total XRF intensity (I/sub p/) at the characteristic line of each element and background intensity (I/sub b/) in vicinity of the line. The correction of matrix effect was achieved by X-ray intensity ratio of peak to background for each element. Eight standard rock samples from Geological Survey of Japan were used as standard materials, and linear calibration curves were obtained by the plot of I/sub p/ - I/sub b/ vs. concentration for Ca, Na and Pb and by the plot of I/sub p//I/sub b/ ratio vs. concentration for Si, Fe, Ti, K, P, Cl, Cr, Mn, Ni, ...

1987-03-01

54

XRF analysis of rock and sediment using standard rock samples  

International Nuclear Information System (INIS)

A simple and rapid method is described for the determination of major and trace elements in rock and sediment samples by wavelength dispersive XRF. Sample measured were made from cellulose powder pressed into 4 cm diameter aluminium ring 0.4 t cm"-"2, and then 1 g of powdered sample (0.08 g cm"-"2) was placed on the disk and repressed at 1.6 t cm"-"2. X-ray measurements were performed for total XRF intensity (I_p) at the characteristic line of each element and background intensity (I_b) in vicinity of the line. The correction of matrix effect was achieved by X-ray intensity ratio of peak to background for each element. Eight standard rock samples from Geological Survey of Japan were used as standard materials, and linear calibration curves were obtained by the plot of I_p - I_b vs. concentration for Ca, Na and Pb and by the plot of I_p/I_b ratio vs. concentration for Si, Fe, Ti, K, P, Cl, Cr, Mn, Ni, Cu, Zn, Pb, Sr and Ba, respectively. The ...

55

Usefulness of "1"8F-FDG PET in intrahepatic cholangiocarcinoma  

International Nuclear Information System (INIS)

Surgical resection is the only curative treatment strategy for intrahepatic cholangiocarcinoma (CC). Therefore, accurate staging is essential for appropriate management of patients with CC. We assessed the usefulness of 2-["1"8F]fluoro-2-deoxy-d-glucose (FDG) positron emission tomography (PET) in the staging of CC. We undertook a retrospective review of FDG PET images in 21 patients (10 female, 11 male; mean age 57 years) diagnosed with CC. Ten patients had hilar CC and 11, peripheral CC. Patients underwent abdominal magnetic resonance imaging (MRI) (n=20) and computed tomography (CT) (n=12) for the evaluation of primary tumours, and chest radiography and whole-body bone scintigraphy for work-up of distant metastases. For semi-quantitative analysis, the maximum voxel standardised uptake value (SUV_m_a_x) was obtained from the primary tumour. All peripheral CCs showed intensely increased FDG uptake, and some demonstrated ring-shaped uptake corresponding to ...

2003-11-01

56

Study of Rare B-Meson Decays Related to the CPObservable sin(2beta+gamma) at the BABAR Experiment  

Energy Technology Data Exchange (ETDEWEB)

This study reports the observation of the decays B{sup 0}{yields}D{sup (*)+}{sub S}{pi}{sup -} and B{sup 0}{yields}D{sup (*)-}K{sup +} in a sample of 230 x 10{sup 6} {Upsilon}(4S) {yields} B{bar B} events collected with the BABAR detector at the PEP-II asymmetric-energy e{sup +}e{sup -} storage ring, located at the Stanford Linear Accelerator Center. The branching fractions {beta}(B{sup 0} {yields} D{sup +}{sub S}{pi}{sup -}) = (1.3 {+-} 0.3 (stat) {+-} 0.2 (syst)) x 10{sup -5}, {beta}(B{sup 0} {yields} D{sup +}{sub S}K{sup +}) = (2.5 {+-} 0.4 (stat) {+-} 0.4 (syst)) x 10{sup -5}, {beta}(B{sup 0}{yields}D{sup (*)+}{sub S}{pi}{sup -}) = (2.8 {+-} 0.6 (stat) {+-} 0.5 (syst)) x 10{sup -5}, and {beta}(B{sup 0}{yields}D{sup (*)-}K{sup +}) = (2.0 {+-} 0.5 (stat) {+-} 0.4 (syst)) x 10{sup -5} are measured. The significance of the measurements to differ from zero are 5, 9, 6, and 5 standard deviations, respectively. This is a first observation of the ...

2007-08-21

57

States with several particles in e{sup +}e{sup -} and {gamma}{gamma} colliders: technique of calculation and launch of a new physics; Etats a plusieurs particules dans les collisionneurs e{sup +}e{sup -} et {gamma}{gamma}: techniques de calcul et effets d'une nouvelle physique  

Energy Technology Data Exchange (ETDEWEB)

The mass generation in the Standard Model of Particles Physics relies on a spontaneous symmetry breaking mechanism. Its implementation is recalled, along with its constraints, both theoretical (Naturalness, Stability, Triviality, Unitarity) and experimental (limits of direct and indirect searches, prospects). Calculation techniques for observables evaluation in Perturbative Field Theory are described, particularly Helicity Amplitude method, which is given in details: fermions and vector bosons, massless and massive. Monte-Carlo integration, and structure functions approximations (which allows non-perturbative calculations) are also detailed. With these tools, a process giving to Physics beyond the Standard Model is studied: it leads to an experimental prediction for the LEP collision ring, taking the classical background into account. Technical aspects of a future photon linear collider are reviewed. The production of heavy vector bosons, ...

1996-10-22

58

Safety-technical characteristics of biomass, coal and straw. Final report  

Energy Technology Data Exchange (ETDEWEB)

Safety-technical factors related to spontaneous ignition and dust explosions of biomasses were investigated. Parametres of dust explosions and effect of inertisation on the maximum pressure (pmax) and the maximum rate of pressure rise (Kstmax) were studied at elevated initial pressure (1-9 bar). The level of inertisation required to prevent dust explosions totally was determined at different initial pressures. The sensitivity of fuels to spontaneous ignition and the effect of pressure on the sensitivity to and temperature of spontaneous ignition were studied on a pressurised dynamic self-ignition equipment. The effect of inertisation on the self-ignition temperature and alternatives of preventing spontaneous ignition by effective inertisation in the pressure ranges of 1 and 25 bar were investigated. As an example of application, results obtained with the laboratory test equipment were extrapolated to bin sizes used in practice. As a factor contributing to spontaneous ignition, the ...

1995-12-31

61

On Lg-Splines.  

Science.gov (United States)

Spline functions associated with a general linear differential operator L which interpolate prescribed data with respect to arbitrary linear functionals are investigated. (Author)

1968-01-01

62

A multi-wavelength scattered light analysis of the dust grain population in the GG Tau circumbinary ring  

Energy Technology Data Exchange (ETDEWEB)

We present the first 3.8 {micro}m image of the dusty ring surrounding the young binary system GG Tau, obtained with the W. M. Keck II 10m telescope's adaptive optics system. THis is the longest wavelength at which the ring has been detected in scattered light so far, allowing a multi-wavelength analysis of the scattering proiperties of the dust grains present in this protoplanetary disk in combination with previous, shorter wavelengths, HST images. We find that the scattering phase function of the dust grains in the disk is only weakly dependent on the wavelength. This is inconsistent with dust models inferred from observations of the interstellar medium or dense molecular clouds. In particular, the strongly forward-throwing scattering phase function observed at 3.8 {micro}m implies a significant increase in the population of large ({approx}> 1 {micro}m) grains, which provides direct evidence for grain growth in the ...

2004-02-04

63

Interactions of Jet Fuels with Nitrile O-Rings: Petroleum-Derived versus Synthetic Fuels  

Energy Technology Data Exchange (ETDEWEB)

A transition from petroleum~derived jet fuels to blends with Fischer-Tropsch (F~T) fuels, and ultimately fully synthetic hydro-isomerized F-T fuels has raised concern about the fate of plasticizers in nitrile-butadiene rubber a-rings that are contacted by the fuels as this transition occurs. The partitioning of plasticizers and fuel molecules between nitrile a-rings and petroleum-derived, synthetic, and additized-synthetic jet fuels has been measured. Thermal desorption of o-rings soaked in the various jet fuels followed by gas chromatographic analysis with a mass spectrometric detector showed many of the plasticizer and stabilizer compounds were removed from the o-rings regardless of the contact fuel. Fuel molecules were observed to migrate into the o-rings for the petroleum-derived fuel as did both the fuel and additive for a synthetic F-T jet fuel additized with benzyl alcohol, ...

2009-01-01

64

IN VACUUM UNDULATOR TASK FORCE REPORT  

Energy Technology Data Exchange (ETDEWEB)

The Green-Chasman lattice, which is the basis for both NSLS storage rings, was conceived with insertion devices in mind. Long, field-free straight sections were provided in the design. The electron optics were chosen so that these sections had zero dispersion and the effects of new magnetic structures placed in these regions would have minimal effect on the emittance of the electron beam. This design concept has been followed by all high-brightness rings which were built subsequent to the NSLS. The X-Ray Ring straight sections also have a very small vertical {beta} function, in addition to the zero dispersion. This was done to optimize the brightness of wiggler sources. There is a further benefit however. The {beta} function determines the beam size and divergence at a particular point in the storage ring lattice. The size is proportional to {radical}{beta} and the divergence is proportional to ...

1998-06-01

65

Unitizations of double-ring structure and Erbium-doped waveguide amplifier for stable and tunable fiber laser  

British Library Electronic Table of Contents (United Kingdom)

We propose and demonstrate experimentally a singlelongitudinal-mode (SLM) fiber double-ring laser using an Erbium-doped waveguide amplifier (EDWA), polarization controller (PC), and a fiber Fabry-Perot tunable filter (FFP-TF) into the ring cavity. In addition, the output power, side-mode suppression ratio (SMSR), and the stabilities of power and wavelength of the laser also are investigated. (Copyright 2007 by Astro Ltd., Published exclusively by WILEY-VCH Verlag GmbH & Co. KGaA)

2007-01-01

66

Thermal-hydraulics performance optimization of Candu fuel using Assert subchannel code  

Energy Technology Data Exchange (ETDEWEB)

An optimization of fuel bundle geometry using the subchannel code ASSERT is performed in support of Candu fuel design to enhance the thermohydraulics performance. The new bundle design is based on a reference CANFLEX bundle with changes to the centre and inner-ring element diameters and pitch-circle diameters (PCDs) of various element rings. Different methods of varying the PCDs for reaching the optimized geometry are considered in an attempt to minimize the optimization effort. The optimized geometry in the present analysis is the one that maximizes the dryout power and that has simultaneous CHF (critical heat flux) initiation involving more than one subchannel rings. (authors)

2007-07-01

67

REQUIREMENTS AND GUIDELINES FOR NSLS EXPERIMENTAL BEAM LINE VACUUM SYSTEMS-REVISION B.  

Energy Technology Data Exchange (ETDEWEB)

Typical beam lines are comprised of an assembly of vacuum valves and shutters referred to as a ''front end'', optical elements to monochromatize, focus and split the photon beam, and an experimental area where a target sample is placed into the photon beam and data from the interaction is detected and recorded. Windows are used to separate sections of beam lines that are not compatible with storage ring ultra high vacuum. Some experimental beam lines share a common vacuum with storage rings. Sections of beam lines are only allowed to vent up to atmospheric pressure using pure nitrogen gas after a vacuum barrier is established to protect ring vacuum. The front end may only be bled up when there is no current in the machine. This is especially true on the VUV storage ring where for most experiments, windows are not used. For the shorter wavelength, more energetic ...

1999-05-01

68

Entangled quantum currents in distant mesoscopic Josephson junctions  

Energy Technology Data Exchange (ETDEWEB)

Two mesoscopic SQUID rings which are far from each other are considered. A source of two-mode nonclassical microwaves irradiates the two rings with correlated photons. The Josephson currents are in this case quantum mechanical operators, and their expectation values with respect to the density matrix of the microwaves yield the experimentally observed currents. Classically correlated (separable) and quantum mechanically correlated (entangled) microwaves are considered, and their effect on the Josephson currents is quantified. Results for two different examples that involve microwaves in number states and coherent states are derived. It is shown that the quantum statistics of the tunnelling electron pairs through the Josephson junctions in the two rings are correlated.

2004-12-22

69

tiAtiA ,', - NASA Technical Report Server (NTRS)  

Science.gov (United States)

the nozzle ring, the collector cup, and the impeller fuel-distribution ... sity of the vaned collector cup and the fuel-transfer passages ..... closure ...

71

Study of free electron laser (FEL) using the electron storage ring 'NIJI-IV'  

International Nuclear Information System (INIS)

We have constructed a racetrack-type compact electron storage ring 'NIJI-IV' for UV FEL. The ring has a hexagonal configuration with two 7.25 m-long straight sections, though its circumference is 29.6 m. A 6.3 m optical klystron (OK) for high FEL gain was installed in one of the long straight sections. The experimental setup for FEL lasing was started at the end of April 1992. The setup on the ring with the OK and the cavity mirror alignment have been completed. The FEL lasings using the NIJI-IV were accomplished at 595-589 nm on August 18, 1992 and at 488 nm on September 18, 1992. The final development target is stable FEL lasing in the UV range. (author).

72

NASA - Act of Creation  

Science.gov (United States)

Act of Creation. 01.08.07. Act of Creation. Prometheus dips into the inner F ring at its farthest point from Saturn in its orbit, creating a dark gore and a ...

73

Helium/solid powder O-ring leakage correlation experiments using a radiotracer  

Energy Technology Data Exchange (ETDEWEB)

UO/sub 2/ definitely leaked past the O-ring in three of the tests confirming the major results of the previous work. Continuous leakage at these levels may require additional precautions under present regulatory policies. The mechanism and the time and particle size dependence for the leakage are not known, but there is some indication leakage is more likely at low temperatures. It is possible leakage is due to movement of the O-ring during temperature or pressure cycling at the beginning or end of a test. The radiotracer method involves less labor and is much less susceptible to contamination than the previous method. Future work will investigate leakage past lubricated O-rings and time dependence of leakage. 1 reference, 1 table.

1984-01-01

74

Extending the service life and power of a gas laser with a coaxial continuous cathode  

Energy Technology Data Exchange (ETDEWEB)

A continuous gas laser may be operated reliably with an increased pressure level and current level without significant cathode sputtering. This increases the service life and the specific power of the laser. The design eliminates the formation of arcs in operational conditions, which also has a positive influence on laser operation. The proposed laser is used successfully in modern interferometry, in geodesy and in materials analysis. The laser design is characterized by the presence of separation rings inside the coaxial cathode. The separation rings are fastened to the anode. The anode is a perforated tube that is connected to two final protective rings. Electrodes from the housing pass through the final rings. In order to increase laser power, two or more lasers of such design are used and are positioned on the same axis in a single housing.

1983-12-31

75

ENGIN\\EE=RING  

Science.gov (United States)

Graphitized thermal carbon black has also been reported by Kalaschinikova et al. (11) to have excellent adsorption properties for CI-C6 alkanes, ...

76

Development of a 2-Aza-Cope-[3+2] Dipolar Cycloaddition Strategy for the Synthesis of Quaternary Proline Scaffolds  

UK PubMed Central (United Kingdom)

A one-pot multicomponent procedure for the synthesis of highly functionalized pyrrolidine rings through a domino...Full Text Available

2010-09-03

77

Conceptual Design of a Support Structure and an Assemble of Detectors Inside a Large Solenoid  

CERN Document Server

In this note we describe a support structure which will hold detector systems (ITS, TPC, TOF) inside the large solenoid. An overall view of ALICE detector is shown on Fig.1. The support structure consists of 2 rings which fixed to an iron yoke and spokes which connect TPC and TOF to these rings. The ITS is connected by spokes to TPC end caps. Between coils there are 7cm spacings which will allow to fix rings to the yoke this support structure will allow to assemble ITS, TPC and TOF together (Fig.2) somewhere on the surface and then transport to the pit and install in the magnet. Two rings (1) are connected with four bars (2). On the bottom bars there are rolls (3) which will allow smoothly insert detectors into the magnet. Spokes (4) are uniformly distributed.

1993-01-01

78

Status of electron accelerators for linear colliders  

Energy Technology Data Exchange (ETDEWEB)

The paper outlines the basic problems concerning creation of electron-positron linear colliders, as well as their present-day status. More details on the question can be found in the proceedings of recent workshops on linear colliders contained in the References. ((orig.)).

1995-02-01

79

Structural intermediates in the assembly of taxoid-induced microtubules and GDP-tubulin double rings: time-resolved X-ray scattering.  

UK PubMed Central (United Kingdom)

We have studied the self-association reactions of purified GDP-liganded tubulin into double rings and taxoid-induced microtubules, employing synchrotron time-resolved x-ray solution scattering. The...Full Text Available

1996-05-01

80

Morphological survey of bar, lens, and ring components in galaxies: Secular evolution in galaxy structure  

International Nuclear Information System (INIS)

A morphological survey of barred galaxies is made to investigate the frequency of occurrence, nature, and size distributions of bars, lenses, inner and outer rings, and global spiral structure. The 121 brightest available barred galaxies are examined on Sky Survey copy plates, and on deeper and larger-scale plates, with the following main results.1. Lenses and inner rings are components of major importance in barred galaxies, occurring, respectively, in 54% of SBO--SBa, and 76% of SBab--SBc galaxies. Few early-type galaxies have rings; almost no late-type ones have lenses.2. There is an intimate connection between bars and lenses: in 17 of 20 galaxies with both components, the bar exactly fills the lens in one dimension.3. We suggest that lenses originate as bars, through an unknown process which makes some bars evolve away to a nearly axisymmetric state. Several properties of the proposed process are deduced. We emphasize ...

81

Dimensional metrology and positioning operations: basics for a spatial layout analysis of measurement systems  

CERN Document Server

Dimensional metrology and positioning operations are used in many fields of particle accelerator projects. This lecture gives the basic tools to designers in the field of measure by analysing the spatial layout of measurement systems since it is central to dimensional metrology as well as positioning operations. In a second part, a case study dedicated to a synchrotron storage ring is proposed from the detection of the magnetic centre of quadrupoles to the orbit definition of the ring.

2010-01-01

82

Error evaluation of the linearized equation of servo valve in hydraulic control systems  

International Nuclear Information System (INIS)

In the procedure of the hydraulic control system analysis, a linearized approximate equation described by the first order term of Taylor's series has been widely used. Such a linearized equation is effective just near the operating point. In this study, the authors estimate computational errors in the process of applying the existing linearized equation stated above. For evaluating the computational accuracy in practical applications of the linearized equations, dynamic behaviors of hydraulic control systems are investigated through simulations with several kinds of representative hydraulic systems and the linearized equations suggested in this study.

2001-11-01

83

Replacement of nickel sealing rings by expanded graphite sealing rings -upgrading of SG primary collector flange connection  

Energy Technology Data Exchange (ETDEWEB)

One of the most loaded parts of a steam generator of VVER 440 MW type are the bolts and thread holes of the primary collector cover sealing set. The strength calculations and tensometric measurings performed during operation proved the high degree of a load on the bolts. The conditions of the stress limitation are not met in some cases according to the pertinent standards. The untightnesses at nickel rings occurred during putting the units of Jaslovske Bohunice and Dukovany nuclear power stations into operation. With regard to improve the reliability, the producer has taken measures to improve the quality of the rings and users have introduced more strict regulations for bolts tightening. Due to these measures the high reliability of the set has been obtained from point of view of the tightness, but substantial reduction of bolts and holes threads loading have not been obtained. Several years operation experience proved relatively low service ...

1997-12-31

84

Gravitational Lensing and Structural Stability of Dark Matter Caustic Rings  

CERN Document Server

Gravitational lensing by the dual cusp catastrophes of the cold dark matter (CDM) caustic rings at cosmological distances may provide the tantalizing opportunity to detect CDM indirectly, and discriminate between axions and weakly interacting massive particles (WIMPs). Caustics are places where the CDM particles are naturally focussed. Our focus is upon the caustic rings which are closed tubes whose cross-section is an elliptic umbilic catastrophe with three dual cusps. A caustic ring has a specific density profile, a specific geometry and, therefore, precisely calculable gravitational lensing signatures. The magnification monotonically increases as the line of sight approaches to the cusps where it diverges in the limit of zero velocity dispersion. In this limit, we find 37% magnification at a sample point near the outer cusps of the CDM caustic rings at cosmological distances. In the presence of ...

2005-01-01

85

Characteristic Of Induction Magnetic Field On The Laboratory Scale Superconducting Fault Current Limiter Circuit  

International Nuclear Information System (INIS)

Model construction of the laboratory scale superconducting fault current limiter circuit (SFCL) has been performed. The SFCL is fault current limiter and used as electric network security. It mainly consists of a copper coil, a superconducting ring and an iron core that are concentrically arranged. The SFCL circuit is essentially a transformer where the secondary windings are being replaced by the ring of YBa_2Cu_3O_7_-_x superconductor (HTS). The ring has critical transition temperature Tc = 92 K and critical current Ic = 3.61 A. Characterization of the SFCL circuit is simulated by ANSYS version 5.4 software. The SFCL circuit consists of load and transformer impedances. The results show that the inductions of magnet field flux in the iron core of primer windings and ring disappear to one other before fault state. It means that impedance of the transformer is zero. After the condition a ...

2004-06-01

86

A fluorescent aminolipid from a green photosynthetic bacterium  

Energy Technology Data Exchange (ETDEWEB)

A preliminary chemical characterization is presented of phosphate-free aminolipids isolation from Chlorobium limicola f. thiosulfatophilum. The lipid contains no phosphorus, glycerol, sugar, ornithine, or lysine. Ultraviolet absorption and fluorescence spectra indicate that the amino moiety of the lipid is an aromatic heterocyclic compound. Infrared spectra indicate that the lipid is a secondary or tertiary amide, and gas chromatograhic analysis of the hydrolyzed lipid shows that for each 1100 g of lipid, 1 mol of myristic acid (C/sub 14:0/) is linked in an amide bond. Acid hydrolysis of the lipid yields two fluorescent substances, A (ninhydrine positive) and B (negative), in addition to myristic acid. Proton nuclear magnetic resonance (NMR) studies indicate that substance A contains a butyl groups attached to a conjugated ring carbon, two equivalent ethyl groups attached to one or two nitrogen atoms, and two downfield protons (8.4 ppm), perhaps attached to a ...

1983-04-12

87

Silund Nanosecond High-Current Linear Induction Accelerator ...  

Science.gov (United States)

... the high current induction linear accelerator of the nanosecond range, meant to be used as injector in the collective ion accelerator, are presented. ...

1972-07-13

88

HSCT4.0 Application - NASA Technical Report Server (NTRS)  

Science.gov (United States)

Geometra'. Scrape Geom- ett_,. Used By: Theoretical. FEM Weight. Apply Linear Delta ...... that the FEM is geometri- cally linear, the differences between ...

89

Background information on the high energy physics program and the proposed Stanford linear electron accelerator project  

CERN Document Server

Background information on the high energy physics program and the proposed Stanford linear electron accelerator project

1961-01-01

91

A comprehensive understanding of the efficacy of N-Ring hardening methodologies in SiGe HBTs  

International Nuclear Information System (INIS)

We investigate the efficacy of mitigating radiation-based single event effects (SEE) within circuits incorporating SiGe heterojunction bipolar transistors (HBTs) built with an N-Ring, a transistor-level layout-based radiation hardened by design (RHBD) technique. Previous work of single-device ion-beam induced charge collection (IBICC) studies has demonstrated significant reductions in peak collector charge collection and sensitive area for charge collection; however, few circuit studies using this technique have been performed. Transient studies performed with Sandia National Laboratory's (SNL) 36 MeV 16O microbeam on voltage references built with N-Ring SiGe HBTs have shown mixed results, with reductions in the number of large voltage disruptions in addition to new sensitive areas of low-level output voltage disturbances. Similar discrepancies between device-level IBICC results and circuit measurements are found for the case of digital shift ...

2010-07-19

98

U Orionis: the evolution and proper motion of the OH maser envelope  

International Nuclear Information System (INIS)

The Jodrell Bank MERLIN array was used to map the OH 1665-and 1667-MHz masers in the circumstellar envelope of U Orionis in 1984, 1986 and 1987. The OH masers lie within a region of extent 130 x 180 AU"2, and have complex distribtuions which are different for each line and polarization. The masers show clumpy structures with a typical clump size of #approx# 25 AU. The strongest emission is from a ring of radius 60 AU which we interpret as part of an expanding, tilted torus. Proper motions have been measured for the OH masers on the ring. The ring has a proper motion of 5.4#+-#1.4 mass yr"-"1 corresponding to a transverse expansion velocity of #approx# 7 km s"-"1 for the period-luminosity distance of U Orionis of 260 pc. (author).

99

The duke XUV FEL storage ring facility  

Energy Technology Data Exchange (ETDEWEB)

In this paper we present status and developments of the Duke storage ring facility. The Duke storage ring facility provides the unique combination of phase-locked light sources ranging from high power OK-4 XUV FEL to quasimonochromatic {gamma}-ray beam and IR/X-ray spontaneous radiation. The XUV OK-4 FEL, which is collaborative project with BlNP, Novosibirsk, is in operation since November, 1996. The OK-4 UV FEL is also used for production of nearly monochromatic {gamma}-ray s with tunable energy. We present the results of UV lasing with the OK4 FEL and selected results of its applications. We will discuss our future plans for extension of this source and status of the construction of dedicated used facility adjacent to the FEL building. (author)

1998-11-01

100

The controlled creation of a maximally entangled state between a SQUID ring and a single electromagnetic field mode  

International Nuclear Information System (INIS)

We consider a SQUID ring inductively coupled to an electromagnetic field mode, both treated quantum mechanically. We demonstrate a method for creating a maximally entangled state between the ring and the field mode. Our method utilises a non-adiabatic external magnetic flux pulse to move into and out of a transition region. Hence, our approach is fundamentally different to techniques based on Landau-Zener tunnelling that can also be used to achieve similar results. Our analysis is extended to include the effects of coupling the system to a dissipative environment. With this model we show that although such an environment makes a noticeable difference to the time evolution of the system, it need not destroy the entanglement of this coupled system over time scales required for quantum technologies.

2010-07-01

101

The cohomology ring of the GKM graph of a flag manifold of classical type  

CERN Document Server

If a closed smooth manifold $M$ with an action of a torus $T$ satisfies certain conditions, then a labeled graph $\\mG_M$ with labeling in $H^2(BT)$ is associated with $M$, which encodes a lot of geometrical information on $M$. For instance, the "cohomology" ring $\\mHT^*(\\mG_M)$ of $\\mG_M$ is defined to be a subring of $\\bigoplus_{v\\in V(\\mG_M)}H^*(BT)$, where $V(\\mG_M)$ is the set of vertices of $\\mG_M$, and is known to be often isomorphic to the equivariant cohomology $H^*_T(M)$ of $M$. In this paper, we determine the ring structure of $\\mHT^*(\\mG_M)$ when $M$ is a flag manifold of classical type directly without using the fact that $\\mHT^*(\\mG_M)$ is isomorphic to $H^*_T(M)$.

2011-01-01

102

Simulation of a storage ring Free Electron Laser with mapping algorithm for distribution functions  

International Nuclear Information System (INIS)

A model for the simulation of the time dependent behavior and the analysis of the equilibrium of the coupled system of storage ring and Free Electron Laser (FEL) is presented. The analysis comprises both amplifier and oscillator FEL. Bunch lengthening and energy widening due to wake forces are taken into account in a self-consistent way. The method is based on a mapping algorithm for means and correlations of the electron distribution function, pioneered by K. Hirata. The evolution of the laser field in the oscillator FEL is described by K. Hirata. The evolution of the laser field in the oscillator FEL is described by supermodes. The model is used to simulate an FEL in a small 500 MeV storage ring with 100 m circumference. Typical values for the output power, spatial, and spectral characteristics of the emitted radiation are presented.

1991-05-06

103

Five centuries of Central European temperature extremes reconstructed from tree-ring density and documentary evidence  

British Library Electronic Table of Contents (United Kingdom)

Future climate change will likely influence the frequency and intensity of weather extremes. As such events are by definition rare, long records are required to understand their characteristics, drivers, and consequences on ecology and society. Herein we provide a unique perspective on regional-scale temperature extremes over the past millennium, using three tree-ring maximum latewood density (MXD) chronologies from higher elevations in the European Alps. We verify the tree-ring-based extremes using documentary evidences from Switzerland, the Czech Republic, and Central Europe that allowed the identification of 44 summer extremes over the 1550-2003 period. These events include cold temperatures in 1579, 1628, 1675, and 1816, as well as warm ones in 1811 and 2003. Prior to 1550, we provide ...

2010-01-01

104

Modeling and numerical simulation of linear and nonlinear spacecraft attitude dynamics and gravity gradient moments: A comparative study  

British Library Electronic Table of Contents (United Kingdom)

In this paper linear and nonlinear models of spacecraft attitude dynamics equations and gravity gradient moments are investigated. In addition, effects of gravity gradient moments on attitude dynamics of the satellite are studied. The purpose of this paper is to present a comparison between nonlinear and linear models of spacecraft attitude dynamics and gravity gradient moments in order to determine divergence of linear approximation from the nonlinear model. Simulation results indicate that designer of spacecraft attitude control subsystem should be meticulous in applying linear approximation of equations especially in low earth orbits. Consequently, finding an upper bound for small angle to keep the linear model valid and precise enough would be a vital part of using linear approximation...

2012-01-01

105

The Dixmier-Moeglin equivalence and a Gel'fand-Kirillov problem for Poisson polynomial algebras  

CERN Document Server

The structure of Poisson polynomial algebras of the type obtained as semiclassical limits of quantized coordinate rings is investigated. Sufficient conditions for a rational Poisson action of a torus on such an algebra to leave only finitely many Poisson prime ideals invariant are obtained. Combined with previous work of the first-named author, this establishes the Poisson Dixmier-Moeglin equivalence for large classes of Poisson polynomial rings, such as semiclassical limits of quantum matrices, quantum symplectic and euclidean spaces, quantum symmetric and antisymmetric matrices. For a similarly large class of Poisson polynomial rings, it is proved that the quotient field of the algebra (respectively, of any Poisson prime factor ring) is a rational function field $F(x_1,...,x_n)$ over the base field (respectively, over an extension field of the base field) with $\\{x_i,x_j\\}= \\lambda_{ij} x_ix_j$ for ...

2007-01-01

106

Simulations of a ring resonator free-electron laser  

International Nuclear Information System (INIS)

In this paper, a relatively high gain (#approx =# 25 to 40 percent) free-electron laser (FEL) with an optical ring resonator is simulated using the code FELEX. The laser system corresponds to the ''burst mode'' FEL scheduled for operation at Boeing Aerospace Company in 1988. The ring consists of paraboloids, grazing incidence by hyperboloids, and a grating rhomb. The wiggler is 5 m in length and has an adjustable taper, while the electron beam is produced by an RF linac. The optical elements of the ring together with the FEL interaction in the wiggler are modeled in three spatial dimensions to investigate the system from start-up to saturation. Both single frequency and finite pulse simulations are performed. The study illustrates the necessity of mode matching the loaded resonator to maximize the extraction efficiency. The mode matching is necessary because the FEL interaction significantly alters the optical beam focus ...

108

Reading strategies in Stargardt's disease with foveal sparing  

UK PubMed Central (United Kingdom)

BackgroundSubjects with a ring scotoma can use two retinal loci, a foveal and a peripheral, for reading. Our aim was to investigate the relative use of both retinal loci as a function...Full Text Available

109

ROMP from ROMP: A New Approach to Graft Copolymer Synthesis  

UK PubMed Central (United Kingdom)

A new strategy is presented for the synthesis of graft copolymers using only the ring-opening metathesis polymerization (ROMP). From a ROMP-derived main chain, pendant maleimide functional groups...Full Text Available

2009-06-23

110

Potassium deposition on a thiophene-terminated alkanethiol monolayer  

International Nuclear Information System (INIS)

Potassium deposition in ultrahigh vacuum on 12-(3-thienyl)dodecanethiol monolayers assembled on gold surfaces has been investigated using X-ray and ultraviolet photoelectron spectroscopies (XPS and UPS). Angle-resolved XPS indicates that initially deposited potassium penetrates the self-assembled monolayer (SAM) and diffuses to the SAM/Au interface. Even after large metal doses, the presence of thiophene ring valence electronic states in the UPS spectra confirms that most of the thiophene rings (at the SAM/vacuum interface) are not covered by potassium. The binding energy shifts of the thiophene ring valence states and the C1s and thiophene S2p peaks, referenced to the Fermi level, are due to the work function changes of the gold substrate. This indicates that these electronic states are pinned to the vacuum level, in contrast to the thiolate S2p orbital, which is pinned to the Fermi level. For large potassium doses, the ...

2009-05-01

111

Performance of Buried Pipe Installations, Summary.  

Science.gov (United States)

The goal of this research project was to determine the eff ects of geometric and mechanical parameters characterizing the soil-structure interaction developed in a buried pipe installation. Parameters such as pipe ring stiff ness, bedding thickness, trenc...

2010-01-01

112

PHARMACOLOGICAL TREATMENTS FOR TINNITUS: NEW AND OLD  

UK PubMed Central (United Kingdom)

Subjective tinnitus, the phantom ringing or buzzing sensation that occurs in the absence of sound, affects 12–14% of adults; in some cases the tinnitus is so severe or disabling that...Full Text Available

2009-01-01

113

NASA Aeronautical Engineenng Aera 3ring Aeronautical Engineenng  

Science.gov (United States)

for an Air Force Manufacturing technology program whose aim is the establishment of organic matrix ...... display considerations for advanced energy/flight management sys- ...... Future System - The Roadmap of the System of the Future - ...... data storage units, pilot's guidance indicators, and a quick look ...

114

Minimizing energy consumption of accelerators and storage ring facilities  

Science.gov (United States)

The discussion of energy usage falls naturally into three parts. The first is a review of what the problem is, the second is a description of steps that can be taken to conserve energy at existing facilities, and the third is a review of the implications of energy consumption on future facilities.

115

Metallic seals offer improved resilience  

International Nuclear Information System (INIS)

Metallic O-ring or Helicoflex seals can prevent relaxation and provide greater resilience than composite seals, helping to keep joints leaktight. Their characteristics and applications in the nuclear industry are outlined. (Author).

116

Mechanism of the dissolution of coals in a mixture of concentrated sulfuric and nitric acids  

British Library Electronic Table of Contents (United Kingdom)

In this work, coals of various ranks were dissolved in an acid melange. With the use of IR spectroscopy, it was found that the mechanism of coal dissolution consists in the grafting of polar groups to the peripheral benzene rings of graphite-like systems.

2011-01-01

117

Impact of the 3,6,9-Trioxadecyloxy Group on Desazadesferrithiocin Analogue Iron Clearance and Organ Distribution  

UK PubMed Central (United Kingdom)

The impact of introducing a 3,6,9-trioxadecyloxyl group at various positions of the desazadesferrithiocin (DADFT) aromatic ring on iron clearance and organ distribution is described. Three DADFT...Full Text Available

2007-07-12

118

I. Cyclopeptide Alkaloids; II. Phycocyanobilipeptides.  

Science.gov (United States)

Several examples of the 14-membered, para-bridged ring system of the cyclopeptide alkaloids have been synthesized via an active ester cyclization. The yield of monomeric cyclopeptide varied from 1 to 33% and was affected by the amino acid substitution pat...

1979-01-01

119

Hydroxylation of 3-Nitrotyrosine and Its Derivatives by Gamma Irradiation  

Science.gov (United States)

... the hydroxyl group with the benzene ring. The molar extinction coefficients for the various species at their respective absorption ... Glya Recorded by 1H-NMR Spectroscopy TABLE 2 Molar Extinction Coeff...

120

Episodic mass loss in binary evolution to the Wolf-Rayet phase: Keck and HST proper motions of RY Scuti's nebula  

CERN Document Server

Binary mass transfer via Roche-lobe overflow (RLOF) is a key channel for producing stripped-envelope Wolf-Rayet (WR) stars and may be critical to account for SN Ib/c progenitors. RY Scuti is an extremely rare example of a massive binary star caught in this brief but important phase. Its toroidal nebula indicates equatorial mass loss during RLOF, while the mass-gaining star is apparently embedded in an opaque accretion disk. RY Scuti's toroidal nebula has two components: an inner ionised double-ring system, and an outer dust torus that is twice the size of the ionised rings. We present two epochs of Lband Keck NGS-AO images of the dust torus, plus three epochs of HST images of the ionised gas rings. Proper motions show that the inner ionised rings and the outer dust torus came from two separate ejection events roughly 130 and 250 yr ago. This suggests that RLOF in massive contact binaries can be ...

2011-01-01

121

Environment influences on the aromatic character of nucleobases and amino acids  

UK PubMed Central (United Kingdom)

Geometric (HOMA) and magnetic (NICS) indices of aromaticity were estimated for aromatic rings of amino acids and nucleobases. Cartesian coordinates were taken directly either from PDB files deposited...Full Text Available

2010-11-01

122

Emergency core cooling device  

International Nuclear Information System (INIS)

Purpose: To effectively cool the reactor core in a steam atmosphere by upwardly directing several of spray nozzles attached to a ring header thereby increasing the flying distance of the spray. Constitution: Ring headers in two upper and lower stages are disposed above the outer circumference of a reactor core and each of the ring headers is mounted with spray nozzles. Among the spray nozzles, at least several nozzles mounted to the ring header at the lower stage are directed such that the center axis for each of the nozzle is raised above the horizontal axis and other several nozzles are mounted with the nozzle center axis directed downwardly from the horizontal axis. Accordingly, even if collapsing phenomenon occurs in the jetting stream due to the condensation in the steams that forms the operation atmosphere of the reactor core spray cooling device, a sufficient amount of emergency cooling water can ...

1983-03-09

123

Biphasic targeting and cleavage furrow ingression directed by the tail of a myosin II  

UK PubMed Central (United Kingdom)

Cytokinesis in animal and fungal cells utilizes a contractile actomyosin ring (AMR). However, how myosin II is targeted to the division site and promotes AMR assembly, and how the AMR coordinates with...Full Text Available

2010-12-27

124

Fermilab Steering Group Report  

Energy Technology Data Exchange (ETDEWEB)

The Fermilab Steering Group has developed a plan to keep U.S. accelerator-based particle physics on the pathway to discovery, both at the Terascale with the LHC and the ILC and in the domain of neutrinos and precision physics with a high-intensity accelerator. The plan puts discovering Terascale physics with the LHC and the ILC as Fermilab's highest priority. While supporting ILC development, the plan creates opportunities for exciting science at the intensity frontier. If the ILC remains near the Global Design Effort's technically driven timeline, Fermilab would continue neutrino science with the NOVA experiment, using the NuMI (Neutrinos at the Main Injector) proton plan, scheduled to begin operating in 2011. If ILC construction must wait somewhat longer, Fermilab's plan proposes SNuMI, an upgrade of NuMI to create a more powerful neutrino beam. If the ILC start is postponed significantly, a central feature of the proposed Fermilab plan calls for building ...

2007-01-01

125

Using ICCD as a fast optical switch to measure harmonic super-radiation from an optical klystron in a storage ring  

International Nuclear Information System (INIS)

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

2001-07-01

126

Ultrasensitive laser isotope analysis in an ion-storage ring  

Energy Technology Data Exchange (ETDEWEB)

We propose a novel method for ultrasensitive isotope analysis that combines magnetic mass selection, resonant charge-exchange neutralization, and resonant laser ionizaion. Our method attains high isotopic abundance selectivity by means of continuous multistage separation of ions stored in a small ring. For the environmentally interesting case of /sup 90/Sr versus /sup 88/Sr we estimate that sensitivity better than 10/sup -15/ for a throughput of 10/sup 13/ atoms/sec and an efficiency (after the ion source) greater than 10% are readily achievable.

1985-09-01

127

Third harmonic lasing in a storage ring free-electron laser  

International Nuclear Information System (INIS)

We report the first experimental achievement of a storage ring free-electron laser (FEL) oscillation on the third harmonic in the near-infrared region. The FEL gain was evaluated as 0.029% per mA. The measured linewidth of the third-harmonic FEL was less than that of the fundamental FEL, and the measured pulse width of the third-harmonic FEL was wider than that of the fundamental FEL. A higher-harmonic FEL should be developed not only to enhance the wavelength region of the FEL but also to vary the characteristics of an FEL micropulse. (author)

2010-09-01

128

Solution conformations of CaCl sub 2 and Ca(NO sub 3 ) sub 2 complexes of chiral tetramethyl 18-crown-6 macrocycles: A 1D and 2D sup 1 H and sup 13 C NMR investigation  

Energy Technology Data Exchange (ETDEWEB)

One- and two-dimensional NMR techniques have been used to investigate the solution structures of (2S,6S,11S,15S)-2,6,11,15-tetramethyl-1,4,7,10,13,16-hexaoxacyclooctadecane (I) and (2R,3R,11R,12R)-2,3,11,12-tetramethyl-1,4,7,10,13,16-hexaoxyacyclooctadecane (II) macrocycle complexes of CaCl{sub 2} and Ca(NO{sub 3}){sub 2} in CDCl{sub 3}. Previous chiroptical studies of these and similar crown complexes by circularly polarized luminescence (CPL), total luminescence (TL), and circular dichroism (CD) spectroscopy have shown that the macrocycle asymmetric carbons in these complexes constrain the ring such that the sense of the ring twist in the S chiral ring complexes is opposite to that in the R chiral ring complexes. These studies have also shown that there is an added chirality element in the di- and trivalent (alkaline earth and lanthanide metal, respectively) nitrate complexes of I and II associated ...

1989-10-04

129

Proceedings of the impedance and bunch instability workshop  

Energy Technology Data Exchange (ETDEWEB)

This report discusses the following topics: impedance and bunch lengthening; single bunch stability in the ESRF; a longitudinal mode-coupling instability model for bunch lengthening; high-frequency behavior of longitudinal coupling impedance; beam-induced energy spreads at beam-pipe transitions; on the calculation of wake functions using MAFIA-T3 code; preliminary measurements of the bunch length and the impedance of LEP; measurements and simulations of collective effects in the CERN SPS; bunch lengthening in the SLC damping rings; and status of impedance measurements for the spring-8 storage ring.

1990-04-01

130

Perturbing the ground ring of 2D string theory  

Energy Technology Data Exchange (ETDEWEB)

In this paper, the authors use free field techniques in D = 2 string theory t calculate the perturbation of the special state algebras when the cosmological constant is turned on. In particular, the authors find that the 'ground cone' preserved by the ring structure is promoted to a three-dimensional hyperboloid as conjectured by Witten. On the other hand, the perturbed (1,1) current algebra of moduli deformations is computed completely, and no simple geometrical interpretation is found. The authors also quote some facts concerning the Liouville matrix a model dictionary in this class of theories.

1992-12-10

131

Lasing below 200 nm in the NIJI-IV compact storage-ring-based free electron laser  

International Nuclear Information System (INIS)

Laser gain of the NIJI-IV compact storage-ring-based Free Electron Laser (FEL) system at AIST reached #approx#9% at 200 nm for an average beam current of 16.3 mA. In addition to such a drastic gain enhancement, improvement of the laser-cavity performance has led to successful FEL lasing in the vacuum ultraviolet below 200 nm even in a compact system. Temporal and spectral characteristics of the NIJI-IV FEL were examined around 200 nm. FEL performance will be briefly discussed from the application point of view.

2004-08-01

132

Inner ring structures in galaxies as distance indicators. III. Distances to 453 spiral and lenticular galaxies  

International Nuclear Information System (INIS)

The diameters d/sub r/ of inner ring structures in disk galaxies are used as geometric distance indicators to derive the distances of 453 spiral and lenticular galaxies, mainly in the distance interval 4<#delta#<63 Mpc. The diameters are weighted means from the catalogs to Kormendy, Pedreros and Madore, and the authors. The distances are calculated by means of the two- and three-parameter formulae of Paper II; the adopted mean distance moduli #mu#"0(r) have mean errors from all sources of 0.6--0.7 mag for the well-observed galaxies.

133

Experience in use of thermal insulation compounds produced by NPP Tekhmet at Ruspolimet  

British Library Electronic Table of Contents (United Kingdom)

Pilot industrial-scale testing of TSK-25 and TSK-10 compounds produced by NPP Tekhmet has been performed at Ruspolimet for siphon casting of 0.7?1.5-metric-ton ingots which are broader on the top (?flowers??) used for production of all-rolled rings; this is as an alternative to the existing process of pouring the steel into molds lubricated with petrolatum. The evaluation tests led to recommendation of the TSK-10 compound for industrial-scale testing; use of this compound enabled the petrolatum-lubricated steel casting process to be abandoned, thereby improving working conditions, and reducing rejects of the all-rolled ring products.

2009-01-01

134

Toxic Effects of Linear Alkylbenzene Sulfonate on Metabolic Activity, Growth Rate, and Microcolony Formation of Nitrosomonas and Nitrosospira Strains  

UK PubMed Central (United Kingdom)

Strong inhibitory effects of the anionic surfactant linear alkylbenzene sulfonate (LAS) on four strains of autotrophic ammonia-oxidizing bacteria (AOB) are reported. Two Nitrosospira...Full Text Available

2001-06-01

136

Dynamic Conditionally Linear Mixed Models for Longitudinal Data  

UK PubMed Central (United Kingdom)

SummaryWe develop a new class of models, dynamic conditionally linear mixed models, for longitudinal data by decomposing the within-subject covariance matrix using a special Cholesky...Full Text Available

2002-03-01

137

Comparison of the e"+e"-, #gamma#e, #gamma##gamma# linear colliders  

International Nuclear Information System (INIS)

The possibility to transform the future linear e"+e"-colliders into the #gamma#e and #gamma##gamma# colliders with approximately the same energies and luminosities was shown earlier. Their properties are compared from the point of view of possible physical investigations on them. 10 refs.; 1 tab.

1992-06-02

138

Adjusting for Health Status in Non-Linear Models of Health Care Disparities  

UK PubMed Central (United Kingdom)

This article compared conceptual and empirical strengths of alternative methods for estimating racial disparities using non-linear models of health care access. Three methods were presented...Full Text Available

2009-03-01

139

A General Model of the Resistive Wall Instability in Linear Accelerators  

Energy Technology Data Exchange (ETDEWEB)

A general model for wakefield-generated instabilities in linear accelerators, originally developed for cumulative beam breakup [1], is applied to the resistive wall instability. The general solution for various bunch charge distributions and application to various accelerator configurations are presented.

2007-01-08

140

Solving Stochastic Linear Programs on a Hypercube ...  

Science.gov (United States)

... commands may be input from a terminal or they ... up the outcomes of the stochastic parameters corre- ... queue of subproblems to be solved, the first ...

1991-08-01

141

Research in Reliability, Availability and Maintainability for ...  

Science.gov (United States)

... Effect of checkpointing and queueing on program performance ... and a large class of stochastic linear ... problem is intrinsically related to K-terminal ...

1990-01-01

142

Linearization of Valve Flow Characteristics for Steam Turbine Control  

Energy Technology Data Exchange (ETDEWEB)

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

2009-10-15

143

Linearization of Valve Flow Characteristics for Steam Turbine Control  

International Nuclear Information System (INIS)

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

2009-10-01

144

Integrated planning problem in supply chains with time-varying delivery  

British Library Electronic Table of Contents (United Kingdom)

We consider a serial supply chain consisting of a raw material supplier, a manufacturer, a distribution centre and a retailer in the presence of time-varying delivery between manufacturer facility and the retailer warehouse. Delivery time functions are developed based on practical data analysis and the cost models for both linear and non-linear delivery time functions are derived. Analytic solution for system with linear delivery times is derived and a search algorithm for system with non-linear delivery times is established. Finally, sensitivity analysis is made to help decision makers achieve a lower total cost in practice.

2011-01-01

145

Influence of HNS on the Microstructure and Properties of Cast ...  

Science.gov (United States)

... The ultimate compressive strength was measured, and values for Young's modulus were calculated from the linear portion of the test curve. ...

1981-04-01

146

Ensemble Forecasting with the Ensemble Transform Kalman ...  

Science.gov (United States)

... of these points corresponds to the ( " 2) term in ... (d) is identical to the 1-sigma ellipse corresponding ... A new approach to linear filtering and predicted ...

2004-08-01

147

Can Markov regime-switching models improve power-price forecasts? Evidence from German daily power prices  

Energy Technology Data Exchange (ETDEWEB)

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

2006-09-15

148

Can Markov regime-switching models improve power-price forecasts? Evidence from German daily power prices  

International Nuclear Information System (INIS)

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

2006-09-01

149

Active Shimmy Control System  

Science.gov (United States)

... Both effects are undoubtedly caused by the ahaping of the spool valve flow characteristics The linear region of response corresponds to ...

1975-12-01

150

ANALYSIS OF BENDING CREEP BEHAVIOR OF SILICON ...  

Science.gov (United States)

... AT 1170 DEG C. A UNIQUE CREEP CONSTITUTIVE EQUATION CONSISTING OF LINEAR AND POWER LAW TERMS WAS PROPOSED, AND ...

151

Familiar arrangement for a Ge(Li) Compton linear polarimeter  

Energy Technology Data Exchange (ETDEWEB)

A simple arrangement of standard horizontal coaxial Ge(Li) detectors with the aim of constructing a Compton linear-polarimeter was tested. High polarization sensitivity and detection efficiency were achieved. The characteristics of the polarimeter and analysis of the observed quantities in terms of the linear-polarization mixing coefficient Hsub(l)(LL') are described.

1982-05-15

152

Dissipativity for linear neutral distributed parameter systems: LOI approach  

British Library Electronic Table of Contents (United Kingdom)

In this work dissipativity of linear neutral distributed parameter systems has been addressed. Delay-dependent sufficient conditions for the dissipativity with respect to the infinite-dimensional version of energy supply rate (Q"1,S"1,R"1) characterized exclusively by unbounded operator Q"1 are established in terms of linear operator inequalities (LOIs). Finally, the 3-dimensional heat equation illustrates our result.

2012-01-01

153

Development on astable multivibrators using the combination of linear and non-linear materials as switching elements based on all optial method  

Science.gov (United States)

In this communication we propose a method to implement an all-optical astable multivibrator using the non-linear material based switches and logic gates. The scheme can operate in real time. The delay time can achieve ps(pico-second). The pulse duration can be made very low and may cross the THz easily by selecting proper material and laser source.

2009-03-01

154

A familiar arrangement for a Ge(Li) Compton linear polarimeter  

International Nuclear Information System (INIS)

A simple arrangement of standard horizontal coaxial Ge(Li) detectors with the aim of constructing a Compton linear-polarimeter was tested. High polarization sensitivity and detection efficiency were achieved. The characteristics of the polarimeter and analysis of the observed quantities in terms of the linear-polarization mixing coefficient Hsub(l)(LL') are described. (orig.).

155

Laparoscopic classification and treatment of the impalpable testis.  

Science.gov (United States)

Laparoscopic orchiopexy has gained popularity in recent years. However, the decision when to perform one-stage laparoscopic orchiopexy without division of the spermatic vessels versus initial ligation of the spermatic vessels followed later by orchiopexy is not clear. A new laparoscopic classification to facilitate decision-making during laparoscopy, according to the position of the impalpable testis and the relation of the spermatic vessels and vas deferens to the internal ring, with a management protocol based on this classification is presented. Over a 2-year period, a total of 37 boys with 52 impalpable gonads underwent a laparoscopic procedure. Four laparoscopic types of testis were noted: type I: no testis visualized; type II: a testis seen at the internal ring with the vas and vessels looping to the internal ring; type III: testis at the internal ring, with vas and vessels going to the testis ...

1999-01-01

156

Effects of ligation type and method on the resistance to sliding of novel orthodontic brackets with second-order angulation in the dry and wet states.  

Science.gov (United States)

Rectangular stainless steel (SS) archwires were coupled with four SS bracket designs: Mini Diamond Twin, which was a conventional twin bracket; VersaT, which had bumps along the slot floor and rounded slot walls; Shoulder, which had bosses outside the tie-wings to lift the ligation off the archwire; and Synergy, which had bosses between the outer and inner tie-wings, bumps along the slot floor, and rounded slot walls. For all designs, the values of resistance to sliding (RS) were measured at five normal forces and 32 second-order angulations in the dry and wet (saliva) states. RS values at these same angles and states were also measured for the following: Mini Diamond Twin brackets ligated with rings and SS ligature wires; VersaT brackets ligated with rings; Shoulder brackets ligated with rings in a figure-8 and a figure-O around the tie-wings; and Synergy brackets ligated with rings around the outer ...

2003-08-01

157

ESR study of the aziridine and azetidine radical cations: evidence for the C...C ring-opened aziridine radical cation  

International Nuclear Information System (INIS)

The radical cations from aziridine and azetidine have been characterized by ESR spectroscopy following their generation in the solid state by #gamma# irradiation of dilute solutions of the parent compounds in the CFCl_3 matrix at 77 K. The ESR parameters of the azetidine radical cation are typical of those for nitrogen-centered amine radical cations such as Me_2NH*"+. On the other hand, the radical cation formed from aziridine has very different ESR parameters that compare closely to those for the isoelectronic C...C ring-opened form of the oxirane radical cation and the allyl radical. The radical cation formed from azetidine is therefore assigned a ring-closed structure with the unpaired electron in a 2p/sub z/ orbital on nitrogen perpendicular to the ring plane, whereas the cation from aziridine is an allylic C...C ring-opened planar isomer with the unpaired electron in a nonbonding #pi# orbital ...

158

ESR study of the aziridine and azetidine radical cations: evidence for the C. C ring-opened aziridine radical cation  

Energy Technology Data Exchange (ETDEWEB)

The radical cations from aziridine and azetidine have been characterized by ESR spectroscopy following their generation in the solid state by ..gamma.. irradiation of dilute solutions of the parent compounds in the CFCl/sub 3/ matrix at 77 K. The ESR parameters of the azetidine radical cation are typical of those for nitrogen-centered amine radical cations such as Me/sub 2/NH*/sup +/. On the other hand, the radical cation formed from aziridine has very different ESR parameters that compare closely to those for the isoelectronic C...C ring-opened form of the oxirane radical cation and the allyl radical. The radical cation formed from azetidine is therefore assigned a ring-closed structure with the unpaired electron in a 2p/sub z/ orbital on nitrogen perpendicular to the ring plane, whereas the cation from aziridine is an allylic C...C ring-opened planar isomer with the unpaired electron in a nonbonding ...

1986-05-22

159

Linearization of Valve Flow Characteristics for Steam Turbine Control  

Energy Technology Data Exchange (ETDEWEB)

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

2009-05-15

160

Linearization of Valve Flow Characteristics for Steam Turbine Control  

International Nuclear Information System (INIS)

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

2009-05-01

161

The potential of the baobab (Adansonia digitata L.) as a proxy climate archive  

Energy Technology Data Exchange (ETDEWEB)

The large girth and immense size of the baobab has caused many to speculate about its age. Unfortunately reliable age estimates cannot be determined from growth rates as the girth varies in response to different moisture regimes. In a similar way, ages cannot be determined from ring-width measurements or X-ray densitometry as the absorbent nature of the soft fibrous wood and distortion upon drying prevent the application of these techniques. The Southern Hemisphere bomb radiocarbon curve was used to demonstrate that the rings of a recently-fallen baobab (Adansonia digitata L.) from Kruger National Park appear to be annual. The detrended C isotope values of finely-ground wholewood from another baobab specimen were found to be highly associated with January precipitation (r = 0.72; p < 0.01). This study demonstrates that high resolution information about past climates may be obtained by analysing the C isotope values from baobab samples ...

2006-10-15

162

The potential of the baobab (Adansonia digitata L.) as a proxy climate archive  

International Nuclear Information System (INIS)

The large girth and immense size of the baobab has caused many to speculate about its age. Unfortunately reliable age estimates cannot be determined from growth rates as the girth varies in response to different moisture regimes. In a similar way, ages cannot be determined from ring-width measurements or X-ray densitometry as the absorbent nature of the soft fibrous wood and distortion upon drying prevent the application of these techniques. The Southern Hemisphere bomb radiocarbon curve was used to demonstrate that the rings of a recently-fallen baobab (Adansonia digitata L.) from Kruger National Park appear to be annual. The detrended C isotope values of finely-ground wholewood from another baobab specimen were found to be highly associated with January precipitation (r = 0.72; p < 0.01). This study demonstrates that high resolution information about past climates may be obtained by analysing the C isotope values from baobab samples even ...

2006-10-01

163

The Bunch Injection Controller for the PEP-II Storage Rings  

CERN Document Server

The PEP-II storage rings at SLAC each have 3492 'buckets' into which electrons and positrons can be injected into the high- and low-energy rings. Equipment to measure the currents of all the individual buckets was originally provided by the Lawrence Berkeley Laboratory and is implemented in VXI-based hardware. Data from this equipment as well as high precision direct current measurement provide the hard data for the Bunch Injection Controller. A large number of parameters determined by injection design considerations as well as set by operators for different circumstances are also used by the software algorithms to determine the desired bucket injection order and charge quantity for each injection pulse. These requests are then passed on to the venerable SLAC master pattern generator, which provides beams for other applications as well. This highly visible and highly successful system is implemented using the EPICS toolkit, and fits well into ...

2001-01-01

164

Study on wavelength shortening and upgrading of the free electron laser (FEL)  

International Nuclear Information System (INIS)

This study is a task of ''Comprehensive study'' in ''nuclear energy basic technology research'', which is promoted under cooperation of four research institutes. The Electrotechnical Laboratory conducted, in 1991 in the first period of colaboration, on successful oscillation at visible region (598 nm) as the first case in Japan, construction of small type accumulation ring NIJI-IV for FEL, successful oscillation of visible range from 595 to 488 nm by installing optical krystron with maximum frequency in the world, and successful emittance lowering of accumulation beam by wide improvement of the ring. In the optical resonator, studies on minute loss measuring technique and on recovery from mirror deterioration were promoted. In the second period started from fiscal year of 1994, studies on FEL oscillation technique in short wavelength and upgrading of FEL corresponding to a frontier area were started, to succeed an oscillation experiment at 350 ...

165

Rotation seismic sensor and its calibration; Kaiten seibun jishinkei no shisaku to kando no kentei  

Energy Technology Data Exchange (ETDEWEB)

Sensor has been developed for the measurement of seismic wave rotary components. The vertical axis rotary component sensor is constituted of four L22Ds, similar to each other in performance, fixed in a ring formation on a metal bed. The ring is 22cm in diameter, and the four coils are connected so that their outputs will be added up. A horizontal axis rotary component sensor is built in the similar way. The rotary component sensors are all connected to a spectrum analyzer for the measurement of micromotions. It is found that the four-L22D combination can detect a rotary component of 335mV/deg/s. The sensor can detect both vertical and horizontal components with roughly the same sensitivity. A ring-form combination of conventional electromagnetic seismometers, though only as a temporary expedient, can perform high-resolution detection of rotary components and determine the absolute values of earthquakes or noise levels. In ...

1997-05-27

166

Radioisotopic techniques for noninvasive detection of platelet deposition in bovine-tissue mitral-valve prostheses and in vitro quantification of visceral microembolism in dogs  

International Nuclear Information System (INIS)

Platelet deposition on bovine pericardial-tissue mitral-valve prostheses in 11 dogs was observed noninvasively by use of "1"1"1In-labeled platelets and quantified after sacrifice at one (n . 3), 14 (n . 3), and 30 (n . 5) days postimplantation (300-400 microCi of labeled platelets having been injected 24 hours previously). Thrombosis on the sewing ring and pericardial leaflets at one and 14 days and on the leaflets at 30 days was delineated in scintiphotos. In vitro quantification (% injected dose) indicated that the leaflets, sewing ring, and perivalvular tissue retained 0.904% of labeled platelets at one day postimplantation, 0.198% at 14 days, and 0.040% at 30 days. Platelet half-life was reduced to 38 hours at 21 days postimplantation but returned toward the normal (50 hours) with fibrous ingrowth in the sewing ring. Microembolism in lung and kidney, as measured by tissue/blood radioactivity ratio, also was decreased ...

167

Plasma jet ignition device  

Energy Technology Data Exchange (ETDEWEB)

An ignition device of the plasma jet type is disclosed. The device has a cylindrical cavity formed in insulating material with an electrode at one end. The other end of the cylindrical cavity is closed by a metal plate with a small orifice in the center which plate serves as a second electrode. An arc jumping between the first electrode and the orifice plate causes the formation of a highly-ionized plasma in the cavity which is ejected through the orifice into the engine cylinder area to ignite the main fuel mixture. Two improvements are disclosed to enhance the operation of the device and the length of the plasma plume. One improvement is a metal hydride ring which is inserted in the cavity next to the first electrode. During operation, the high temperature in the cavity and the highly excited nature of the plasma breaks down the metal hydride, liberating hydrogen which acts as an additional fuel to help plasma formation. A second improvement consists of a cavity ...

1985-01-15

168

Mode-locked YAG-Nd ring laser with unidirectional stimulated emission  

Energy Technology Data Exchange (ETDEWEB)

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

1981-05-01

169

Magnetic Fields in Massive Stars. II. The Buoyant Rise of Magnetic Flux Tubes Through the Radiative Interior  

CERN Document Server

We present results from an investigation of the dynamical behavior of buoyant magnetic flux rings in the radiative interior of a uniformly rotating early-type star. Our physical model describes a thin, axisymmetric, toroidal flux tube that is released from the outer boundary of the convective core, and is acted upon by buoyant, centrifugal, Coriolis, magnetic tension, and aerodynamic drag forces. We find that rings emitted in the equatorial plane can attain a stationary equilibrium state that is stable with respect to small displacements in radius, but is unstable when perturbed in the meridional direction. Rings emitted at other latitudes travel toward the surface along trajectories that largely parallel the rotation axis of the star. Over much of the ascent, the instantaneous rise speed is determined by the rate of heating by the absorption of radiation that diffuses into the tube from the external medium. Since the time ...

2003-01-01

170

Lubrication of an 85-mm ball bearing with RP-1  

Energy Technology Data Exchange (ETDEWEB)

A parametric experimental investigation of an 85 millimeter bore angular contact ball bearing running in RP-1 fuel was performed at speeds of 10,000 to 24,000 rpm. Thrust loads were varied from 4450 to 17,800 Newtons (1000 to 4000 lbs.). Radial loads were varied from 1335 to 13,350 Newtons (300 to 3000 lbs.). RP-1 lubrication for the bearing was provided through a stationary jet ring located adjacent to the test bearing outer ring. Increases in both the thrust and radial loads resulted in increased bearing temperature, while increases in shaft speed resulted in much more dramatic increases in bearing temperature. These trends are typical for ball bearings operating under these types of conditions. Results are given for outer ring temperatures of the test bearing at the various test conditions employed. In addition, the heat energy removed from the bearing by the RP-1 was determined by measuring the increase in temperature ...

1993-01-01

171

Influence of catalytic activity and reaction conditions on the product distribution in coal liquefaction; Sekitan ekikayu no seiseibutsu bunpu ni taisuru shokubai kassei oyobi hanno joken no eikyo  

Energy Technology Data Exchange (ETDEWEB)

The NiMo sulfide supported on Ketjen Black (KB) was more effective and yielded lighter oil products containing light fractions with their boiling point below 300{degree}C during the two stage liquefaction combining low temperature and high temperature hydrogenation the conventional NiMo/alumina catalyst and FeS2 catalyst. Although the NiMo/alumina yielded increased oil products during the two stage liquefaction, the lighter oil fractions did not increase and the heavier fractions increased mainly. This suggests that the hydrogenation of aromatic rings and successive cleavage of the rings are necessary for producing the light oil, which is derived from the sufficient hydrogenation of aromatic rings using catalysts. For the two stage reaction with NiMo/KB catalyst, it was considered that sufficient hydrogen was directly transferred to coal molecules at the first stage of the low temperature reaction, which promoted the ...

1996-10-28

172

Evidence for divided automatic attention  

Scientific Electronic Library Online (English)

Abstract in english A long-standing debate in the literature is whether attention can form two or more independent spatial foci in addition to the well-known unique spatial focus. There is evidence that voluntary visual attention divides in space. The possibility that this also occurs for automatic visual attention was investigated here. Thirty-six female volunteers were tested. In each trial, a prime stimulus was presented in the left or right visual hemifield. This stimulus was characteriz (more) ed by the blinking of a superior, middle or inferior ring, the blinking of all these rings, or the blinking of the superior and inferior rings. A target stimulus to which the volunteer should respond with the same side hand or a target stimulus to which she should not respond was presented 100 ms later in a primed location, a location between two primed locations or a location in the contralateral hemifield. Reaction time to the ...

2008-02-01

173

Evaluation of selected elastomer O-ring pump seals for service at the Wilsonville, Alabama, Advanced Coal Liquefaction Research and Development Facility. [Ethylenepropylenediene monomer compounds  

Energy Technology Data Exchange (ETDEWEB)

Previous laboratory tests of elastomer O-rings in coal liquefaction solvents conducted at L'Garde, Inc., indicated that certain ethylenepropylenediene monomer (EPDM) compounds provided the best performance when a backup ring was used to limit swelling. Before service testing in a pump at the Wilsonville, Alabama, Advanced Coal Liquefaction Research and Development Facility, tests of six selected elastomers in the appropriate Wilsonville-produced solvent were conducted at Oak Ridge National Laboratory (ORNL). The ORNL tests measured the elastomers' changes in cross section, weight, density, and relative flexibility. Although two perfluoroelastomers showed less degradation of most properties during these tests, it was decided to proceed with service testing of two EPDM elastomers because of their much lower cost. 5 refs., 14 figs., 7 tabs.

1986-08-01

174

Evaluation of paramagnetic species in coals with iodine doping technique; Yoso tenkaho wo mochiita sekitanchu no jojiseishu no hyoka  

Energy Technology Data Exchange (ETDEWEB)

Electron paramagnetic resonance (EPR) of coals was considered by using iodine doping technique. Sub-bituminous coal (WA) and bituminous coal (UF) were used to observe EPR spectra using microwaves. With the UF coal, strength of the narrow component of the spectra was found constant regardless of amount of the doped iodine, wherein radicals without interaction with iodine were detected. Strength of the broad component increased with the iodine doping amount, where in deviation of {pi} electrons was detected, which have been generated as a result of interaction between aromatic rings and iodine in the coals. Spin concentration of the WA coal with low coalification degree is constant regardless of the iodine doping amount, and the interaction of the iodine with the aromatic rings was found small. The higher the coalification degree, the more the aromatic ring structure grows, and electron donor capability for the iodine ...

1996-10-28

175

Environmental distribution and behavior of 3H and 14C around Wolsong Nuclear Power Plants.  

Science.gov (United States)

To estimate of the dispersion trend of 3H and 14C discharged from the Wolsung Nuclear Power Plants, the present level of 3H and 14C in environmental samples in the vicinity of the Wolsong site was studied. Tree-ring cellulose analyses were carried out for retrospective evaluation of 3H and 14C in the environment around the Wolsong Nuclear Power Plants. 3H released from the Wolsong Nuclear Power Plants has affected an area up to a 25-km radius from the site, while almost all 14C was deposited within a 2-km radius, reaching to a natural level over 2 km. Organically bound tritium concentrations in tree rings were strongly correlated with the gaseous tritium discharge rate, while delta14C (excess) in tree rings ranged from 204 per thousand to 460 per thousand, which did not significantly vary with year. PMID:10832930

2000-06-01

176

Chemistry and morphology of coal liquefaction. Quarterly report, January 1, 1986-March 31, 1986. [1,2,3,4 tetrahydroquinoline, 2-propylaniline, quinoline cyclohexylamine and propylbenzene  

Science.gov (United States)

Having recently discovered that polynuclear heteroaromatic nitrogen compounds can be selectively reduced only at the nitrogen containing ring, we have now turned our attention towards the cleavage of the carbon nitrogen bonds in this reduced ring. Highlights for this reporting period are: (1) Studies with the 50% nickel oxide catalyst clearly show that 1,2,3,4-tetrahydroquinoline(THQ) provides approximately 20% more liquid product that does quinoline. Thus a first step selective hydrogenation to 1,2,3,4-THQ would enhance the overall HDN reaction to provide a more substantial conversion to substituted benzene and aniline derivatives. (2) The dramatic effect of the nitrogen atom is to inhibit aromatic ring hydrogenation and, to some extent, carbon-carbon bond hydrogenolysis reactivity. This is shown with proplybenzene as the substrate, where only methane gas is produced in the HDN reaction with the 50% nickel oxide catalyst. ...

1986-03-01

177

Behavior of the positron beam of the Super-ACO storage ring in response to a modification of the RF frequency for free-electron laser experiments  

International Nuclear Information System (INIS)

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

178

An Investigation of the Relationship Between Tritium in Groundwater and the Dendrochronology of Tritium in Trees at the Savannah River Site. Final report  

Energy Technology Data Exchange (ETDEWEB)

This project was supported through ERDA to demonstrate that the temporal distribution of tritium can be documented by the analysis of bound hydrogen in annual tree-ring samples. The project focuses on two sample locations at the Savannah River Site (SRS), a nuclear material production facility located in Aiken, SC. The SRS provided samples of cross-sections from a single tree that were to be pooled together for analysis. Annual tree-rings were identified in each cross-section sample and separated for the period 1954 to 1993. These annual samples were ground and chemically treated to separate the hollocellulose fraction of the wood, then subsequently combusted and the resulting water counting using low-level liquid scintillation counting equipment. Additionally, the ground annual tree-rings were gamma-counted to determine any temporal variation in radionuclide activity and analyzed with x-ray fluorescence to find any ...

1995-03-21

179

What are $E_{\\infty}$ ring spaces good for?  

CERN Document Server

Infinite loop space theory, both additive and multiplicative, arose largely from two basic motivations. One was to solve calculational questions in geometric topology. The other was to better understand algebraic K-theory. The Adams conjecture is intrinsic to the first motivation, and Quillen's proof of that led directly to his original, calculationally accessible, definition of algebraic K-theory. In turn, the infinite loop understanding of algebraic K-theory feeds back into the calculational questions in geometric topology. For example, use of infinite loop space theory leads to a method for determining the characteristic classes for topological bundles (at odd primes) in terms of the cohomology of finite groups. We explain just a little about how all that works, focusing on the central role played by E infinity ring spaces.

2009-01-01

180

Valued Graphs and the Representation Theory of Lie Algebras  

CERN Document Server

Quivers (directed graphs) and species (a generalization of quivers) and their representations play a key role in many areas of mathematics including combinatorics, geometry, and algebra. Their importance is especially apparent in their applications to the representation theory of associative algebras, Lie algebras, and quantum groups. In this paper, we discuss the most important results in the representation theory of species, such as Dlab and Ringel's extension of Gabriel's theorem, which classifies all species of finite and tame representation type. We also explain the link between species and K-species (where K is a field). Namely, we show that the category of K-species can be viewed as a subcategory of the category of species. Furthermore, we prove two results about the structure of the tensor ring of a species containing no oriented cycles that do not appear in the literature. Specifically, we prove that two such species have isomorphic tensor ...

2011-01-01

181

Synthesis and investigation of #pi#-conjugated azomethine self-assembled multilayers by layer-by-layer growth  

International Nuclear Information System (INIS)

Layer-by-layer formation for #pi#-conjugated azomethine multilayers bonded on substrates was investigated. The multilayers were synthesized using ethanol (EtOH) and dichloromethane (DCM) as reaction solvents. The multilayer characteristics were analyzed using UV-vis absorption spectroscopy, ellipsometric thickness, and atomic force microscopy. The absorption spectra and ellipsometric thicknesses of multilayers formed using EtOH and DCM were compared. The results indicate that EtOH is more suitable than DCM for such layer-by-layer formation. In addition, bandgaps estimated from the absorption edge of multilayers were investigated. The results indicate that the bandgap decreases as the number of benzene rings contained in the molecular chain of the multilayer increases. Also, a multilayer with four benzene rings bonded on a substrate had a bandgap close to that of a polymer with a similar chemical structure.

2010-07-01

182

Recent progress in the storage ring NIJI-IV free electron laser  

International Nuclear Information System (INIS)

A compact storage ring NIJI-IV free electron laser (FEL) is being developed as a tunable light source which covers a wide wavelength range from the VUV to the IR. To shorten the FEL wavelength in the VUV region, the optical cavity mirror was improved and the original loss of Al_2O_3/SiO_2 multilayer mirror around 195nm was decreased 30% compared with that of the previous one. New optical cavity system equipped with two remotely interchangeable mirrors was installed for the UV/VUV FEL to stabilize the laser and also to extend the tuning range. As for construction of the IR FEL, modification of the beam transport system to make space for installation of the optical cavity was completed. (author)

2006-08-01

183

Performance of ceramics in ring/cylinder applications  

Energy Technology Data Exchange (ETDEWEB)

In support of the efforts to apply ceramics to advanced heat engines, a study is being performed of the performance of ceramics at the ring/cylinder interface of advanced (low heat rejection) engines. The objective of the study, managed by the Oak Ridge National Laboratory, is to understand the basic mechanisms controlling the wear of ceramics and thereby identify means for applying ceramics effectively. Attempts to operate three different zirconias, silicon carbide, silicon nitride, and plasma-sprayed ceramic coatings without lubrication have not been successful because of excessive friction and high wear rates. Silicon carbide and silicon nitride perform well at ambient temperatures with fully formulated mineral oil lubrication, but are limited to temperatures of 500F because of the lack of suitable liquid lubricants for higher temperatures.

1987-01-01

184

Mineralization and volatilization of ring labelled "1"4C-2,4-D in three different soils  

International Nuclear Information System (INIS)

Mineralization and volatilization of ring labelled "1"4C-2,4-dichlorophenoxyacetic acid in soil was studied over a period of six weeks under laboratory conditions at 25 deg. C in three different soils collected from three sites, Delhi, Jaipur and Ludhiana. A very slow rate of both mineralization and volatilization was observed in all the three soils. The observed mineralization, was highest for the Delhi soil, 0.93%, followed by the Ludhiana soil, 0.73% and the Jaipur soil 0.14% in 42 days. The extent of volatilization was 0.46% for the Jaipur soil, 0.37% for the Ludhiana soil and 0.32% for the Delhi soil. (author)

2001-11-01

185

Ligand Tuning in Asymmetric Hydrovinylation of 1,3-Dienes. A Stereoselective Route to either Steroid-C20 (S) or -C20 (R) Derivatives  

Science.gov (United States)

1,3-Dienes derived from steroidal D-ring C17-ketones undergo Ni(II)-catalyzed hydrovinylation to give 1,2- or 1,4-addition of ethylene. Using finely tuned phosphoramidite ligands it is possible to synthesize either the C20 (R)- or the C20 (S)-derivatives without mutual contamination. The proportion of the 1,4-adduct, which is also formed stereoselectively, can be minimized by optimizing the reaction conditions. Since the two alkenes in the resultant dienes have differing steric demands for many potential reactions, and are ideally juxtaposed for further D-ring functionalization, these intermediates could be useful for the preparation of biologically important compounds such as vitamin D analogs and various antitumor steroidal glycosides.

2008-06-21

186

Laparoscopic Orchiectomy and Subsequent Internal Ring Closure for Extra-abdominal Testicular Nubbin in Children  

British Library Electronic Table of Contents (United Kingdom)

Objectives To present our preliminary experience with laparoscopic groin exploration and subsequent laparoscopic orchiectomy and internal ring closure for testicular nubbin in children and discuss the usefulness of our new treatment strategy. The advantages of laparoscopic orchiopexy for intra-abdominal testis are the ability to start treatment as soon as a diagnosis has been made and to permit minimally invasive surgery. These advantages can apply to laparoscopic orchiectomy for a testicular nubbin. Methods A total of 6 boys with a testicular nubbin (age range 14-76 months, mean age 27.3 months) underwent laparoscopic orchiectomy at our institution from June 2007 to June 2008. We opened the posterior parietal peritoneum by incising the peritoneum lateral to the spermatic vessel, distal to...

2009-01-01

187

Gamma rays produced by inverse Compton scattering in the super-ACO storage ring free electron laser  

International Nuclear Information System (INIS)

The inverse Compton scattering between positron bunches and the Free Electron Laser (FEL) of the SuperAco storage ring generates a collimated and tunable gamma-ray beam. The use of the FEL instead of a conventional laser, automatically provides the transverse alignment and synchronisation of the electron and optical beams. The Super-ACO FEL is operated in the 300-430 nm range at 800 MeV with a high repetition rate (8 MHz) and an average transmitted power of 300 mW at 350 nm. High energy gamma rays of 35 MeV are produced with a rate of 1.5 10 7 photons/second and good monocromaticity (about 10%). Applications of the SuperAco FEL installation for diamond irradiation and biological studies are envisaged. (author)

2000-06-05

188

Full-scale model of cooling and heating system for JT-60 vacuum vessel  

Science.gov (United States)

A full-scale model of a rigid sectorial ring and a set of bellows which was covered with a temperature control layer and a coolant supply equipment was constructed to verify the adequacy of the heating and cooling system designed for JT-60. To cool and heat it effectively and to decrease the temperature differences among the various parts in the vacuum vessel, heater units and cooling pipes were located on the surface of the ring. The temperature control layer is to heat the vessel to 500/degree/sub //C within 70 hours and to maintain it at the temperature for 48 hours for simulating the state of bakeout. Subsequently the vessel is cooled down within about the same time as in heating. Prior to the series of tests, numerical analyses were performed to predict the cooling and heating efficiencies on the model and to examine the method of the temperature regulation.

1981-01-01

189

Energy saver A-sector power test results  

Energy Technology Data Exchange (ETDEWEB)

The superconducting magnets and associated cryogenic components in A-sector represent the initial phase of installation of the Fermilab superconducting accelerator, designed to accelerate proton beams to energies of 1 TeV. Installation of the magnets, comprising one-eighth of the ring, was completed in December, 1981. Cooldown and power tests took place in the first half of 1982, concurrent with main ring use for 400 GeV high energy physics. The tests described in this paper involved 151 cryogenic components in the tunnel: 94 dipoles, 24 quadrupoles, 25 spool pieces, 3 feed cans, 4 turn-around boxes and 1 bypass. Refrigeration was supplied by three satellite refrigerators, the Central Helium Liquefier, and two compressor buildings. The magnets were powered by a single power supply.

1982-09-15

190

Effects of carbon fiber surface treatment on the tribological properties of 2D woven carbon fabric/polyimide composites  

British Library Electronic Table of Contents (United Kingdom)

Polyacrylonitrile (PAN)-based carbon fabric (CF) was modified with strong HNO3 oxidation and then introduced into polyimide (PI) composites. The friction and wear properties of the carbon fabric reinforced polyimide composites (CFRP), sliding against GCr15 stainless steel rings, were investigated on an M-2000 model ring-on-block test rig under dry sliding. Experimental results revealed that the carbon fiber surface treatment largely reduced the friction and wear of the CFRP. Compared with the untreated ones, the surface-modified CF can enhance the tribological properties of CFRP efficiently due to the improved adhesion between the CF and the PI matrix. Scanning electron microscope (SEM) and X-ray photoelectron spectroscopy (XPS) study of the carbon fiber surface showed that the fiber surfa...

2009-01-01

191

Effect of carbon fibers surface treatment on tribological performance of polyurethane (PU) composite coating  

British Library Electronic Table of Contents (United Kingdom)

The carbon fibers (CF) were pre-treated in two different ways: no pre-treatment, and activation in HNO3 plus application of toluene-2,4-diisocyanate (TDI). Carbon fibers have been introduced into polyurethane (PU) composite coatings. The tribological behaviors of the polyurethane composite coating filled with CF or TDI-modified CF (TDI-CF) were studied using a ring-on-block wear tester under dry sliding, and the worn surfaces of the filled PU coatings and transfer films formed on the surface of the counterpart ring sliding against the PU coating were investigated by SEM and optical microscope (OM), respectively. Owing to the effective improvement of the interfacial adhesion between the CF and polyurethane matrix, compared with the cases of untreated CF, the employment of low content TDI-CF...

2008-01-01

192

Effect of carbon fiber surface treatments on the flexural strength and tribological properties of short carbon fiber/polyimide composites  

British Library Electronic Table of Contents (United Kingdom)

Pitch-based short carbon fibers (CFs) were treated by air oxidation and cryogenic nitrogen, respectively. Thereafter the treated and untreated CFs were incorporated into polyimide (PI) matrix to form composites. The CFs before and after treatment were examined by XPS and SEM.The flexural strength of the specimen was determined in a three-point test machine and the tribological properties of PI composites sliding against GCr15 steel rings were evaluated on an M-2000 model ring-on-block test rig. The results show that the surface of the treated CFs became rougher. Lots of active groups formed on the CF surface after air oxidation.The treatment can effectively improve the mechanical and tribological properties in their PI composites due to the enhanced fiber-matrix interfacial bonding. Copyri...

2008-01-01

193

Development of ball bearings with solid film for high-vacuum, high-temperature, high-speed application  

Energy Technology Data Exchange (ETDEWEB)

This paper describes the experimental results of long-life solid lubricated ball bearings tested under high-vacuum of 10 exp -4 Pa, high-temperature of 300 C, and high-speed (9000 rpm) conditions. For full ball-type bearings, the thin soft metals, either Ag or Pb, which were coated on the races and balls, appeared to have good torque properties. However, the durability of such bearings was less than 300 hours. The transfer films from the lamellar solid MoS2 and metal composite retainers improved the torque and wear properties. For ceramic, i.e., silicon nitride, balls used with steel rings, wear occurred on the inner rings. All ceramic bearings with composite retainers showed improved torque and wear properties. 18 refs.

1993-04-01

194

Consistency conditions in the chiral ring of super Yang-Mills theories  

CERN Document Server

Starting from the generalized Konishi anomaly equations at the non-perturbative level, we demonstrate that the algebraic consistency of the quantum chiral ring of the N=1 super Yang-Mills theory with gauge group U(N), one adjoint chiral superfield X and N_f<=2N flavours of quarks implies that the periods of the meromorphic one-form Tr dz/(z-X) must be quantized. This shows in particular that identities in the open string description of the theory, that follow from the fact that gauge invariant observables are expressed in terms of gauge variant building blocks, are mapped onto non-trivial dynamical equations in the closed string description.

2007-01-01

195

Chiral Rings, Mirror Symmetry and the Fate of Localized Tachyons  

Energy Technology Data Exchange (ETDEWEB)

We study the localized tachyon condensation of non-supersymmetric orbifold backgrounds in their mirror Landau-Ginzburg picture. We first show that the R-charges of chiral primaries increase under the process of condensing the tachyon in the same chiral ring. Then, utilizing the existence of four copies of (2,2) worldsheet supersymmetry, we show that the minimal tachyon mass in twisted sectors increases in CFT and type 0 string and it plays the role of the c-function of the twisted sectors. We also study the GSO projection in detail and show that type II decays to only to type II while type 0 can mix with type 0 and II under the RG-flow.

2003-03-20

196

A new model for precision control of the radius in in-plane roll-bending of strip considering rolls and stand deflections  

British Library Electronic Table of Contents (United Kingdom)

The rolls and stand deflections induced by rolling force lead to a significant decrease in the radius prediction accuracy of the ring product in the in-plane roll-bending of strip. To precisely predict the deflections and control the radius, a new analytical model is developed. Numerical implementation is presented to solve the theoretical rolling force, the deflections as well as the inherent force-deflection relationship considering the interactions of the strip workpiece, the rolls and the stand. A series of profile measurements of the formed ring parts are made to assess the accuracy of the predicted deflections. Different control approaches are used in the experiments to validate the radius control model. The experimental results show that the model is reliable to control the radii wi...

2011-01-01

197

FEA Analysis of AP-0 Target Hall Collection Lens (Current Design)  

Energy Technology Data Exchange (ETDEWEB)

The AP-0 Target Hall Collection Lens is a pulsed device which focuses anti-protons just downstream of the Target. Since the angles at which the anti-protons depart the Target can be quite large, a very high focusing strength is required to maximize anti-proton capture into the downstream Debuncher Ring. The current design of the Collection Lens was designed to operate with a focusing gradient of 1,000 T/m. However, multiple failures of early devices resulted in lowering the normal operating gradient to about 750 T/m. At this gradient, the Lens design fares much better, lasting several million pulses, but ultimately still fails. A Finite Element Analysis (FEA) has been performed on this Collection Lens design to help determine the cause and/or nature of the failures. The Collection Lens magnetic field is created by passing high current through a central conductor cylinder. A uniform current distribution through the cylinder will create a tangential or azimuthal ...

2001-06-22

198

Gauge invariant perturbation theory in spatially homogeneous cosmology  

International Nuclear Information System (INIS)

The perturbations of the L.R.S. class A spatially homogeneous spacetimes are treated using Hamiltonian methods in conjunction with techniques from the theory of Lie group harmonic analysis. These latter techniques lead to a simple way of handling any set of tensor equations on these background spacetimes which has the same symmetry group as the space-time metric. Once this approach is developed, the Hamiltonian formulation is used to recover in a clean way the Bonanos equations for the perturbations of the perfect fluid models of the class of spacetimes under consideration. The conserved quantities associated with the four-dimensional symmetry group are evaluated and their role in the linearized Hamiltonian dynamics is discussed. The time-dependent linear canonical transformation of the linearized vacuum gravitational phase space adapted to Moncrief's gauge invariant decomposition is described in general for these models ...

199

Top physics at the Tevatron Collider  

Energy Technology Data Exchange (ETDEWEB)

The top quark has been discovered in 1995 at the CDF and DO experiments located in the Tevatron ring at the Fermilab laboratory. After more than a decade the Tevatron collider, with its center-of-mass energy collisions of 1.96 TeV, is still the only machine capable of producing such exceptionally heavy particle. Here I present a selection of the most recent CDF and DO measurements performed analyzing {approx} 1 fb{sup -1} of integrated luminosity.

2007-10-01

200

The metabolism of L-tryptophan by isolated rat liver cells. Effect of albumin binding and amino acid competition on oxidatin of tryptophan by tryptophan 2,3-dioxygenase.  

UK PubMed Central (United Kingdom)

1. Novel methods, using L-[ring-2-14C]tryptophan, are described for the measurement of tryptophan 2,3-dioxygenase activity and tryptophan accumulation in isolated rat liver cells. 2. The effects of...Full Text Available

1980-03-15

201

The influence of the nonhomogeneous temperature field on the optimal winding prestress of the compound pressure vessel  

Energy Technology Data Exchange (ETDEWEB)

The completed ribbon-winding theory, including temperature loading of the high-pressure compound vessel, was proposed. The influence of the bending stress in the wound ribbon is taken into account. Internal core of the compound vessel consists of matrix and ring, made of different materials. The relations were derived in analytical form, describing the radial distribution of necessary tangential prestressing.

1996-11-01

202

The effects of diphenyleneiodonium on mitochondrial reactions. Relation of binding of diphenylene[125I]iodonium to mitochondria to the extent of inhibition of oxygen uptake.  

UK PubMed Central (United Kingdom)

1. Several ring-substituted derivatives of diphenyleneiodonium catalyse the exchange of Cl- and OH- ions across the inner membrane of rat liver mitochondria. They also inhibit state 3 and state 3u oxidations...Full Text Available

1976-08-15

203

Super-ACO free-electron laser (FEL) operation with a reduced momentum compaction factor  

International Nuclear Information System (INIS)

A new optics providing an emittance close to the minimum theoretical value has been proposed for the Super-ACO storage ring with a reduced value of the momentum compaction factor and non-zero dispersive function in the Free-Electron Laser (FEL) section. It has been adapted to the FEL operation mode, with two RF cavities at 100 and 500 MHz. The obtained results concerning this new optics and the FEL oscillation are presented.

2002-05-01

204

Rising Total Hadron-Hadron Cross Sections  

CERN Document Server

A historical summary is made on the measurements concerning the rising total hadron-hadron cross sections at high energies. The first part of this paper concerns the total cross section measurements performed at the Brookhaven, Serpukhov and Fermilab fixed target accelerators; then the measurements at the CERN Intersecting Storage Rings (ISR), and at the CERN and at the Tevatron Fermilab proton-antiproton colliders; finally the cosmic ray measurements at even higher energies. A short discussion on Conclusions and Perspectives follows.

2007-01-01

205

Real time closed orbit correction system  

Energy Technology Data Exchange (ETDEWEB)

We describe a global closed orbit feedback experiment, based upon a real time harmonic analysis of both the orbit movement and the correction magnetic fields. The feedback forces the coefficients of a few harmonics near the betatron tune to vanish, and significantly improves the global orbit stability. We present the results of the experiment in the UV ring using 4 detectors and 4 trims, in which maximum observed displacement was reduced by a factor of between 3 and 4. 4 refs., 3 figs.

1989-01-01

206

Reaction of ethyl azidoformate with acenaphthylene: isolation and structure of an acenaphthylene-pyridinium-2,6 betaine adduct  

International Nuclear Information System (INIS)

Ethyl azidoformate reacts, on thermolysis with acenaphthylene, to give a 1:2 adduct involving sequential aziridine formation, ring-opening to a 1,3-dipolar pyridinium-2,6-betaine, and trapping of the dipole with acenaphthylene. The structure of the adduct was confirmed by X-ray crystallography.

207

Raman Under Nitrogen. The High-Resolution Raman Spectroscopy of Crystalline Uranocene, Thorocene, and Ferrocene  

Science.gov (United States)

The utility of recording Raman spectroscopy under liquid nitrogen, a technique we call Raman Under Nitrogen (RUN), is demonstrated for ferrocene, uranocene and thorocene. Using RUN, low temperature (liquid nitrogen cooled) Raman spectra for these compounds exhibit higher resolution than previous studies and new vibrational features are reported. The first Raman spectra of crystalline uranocene at 77 K are reported using excitation from argon (5145 ) and krypton (6764 ) ion lasers. The spectra obtained showed bands corresponding to vibrational transitions at 212, 236, 259, 379, 753, 897, 1500, and 3042 cm-1 , assigned to ring-metal-ring stretching, ring-metal tilting, out-of-plane CCC bending, in-plane CCC bending, ring-breathing, C-H bending, CC stretching and CH stretching, respectively. The assigned vibrational bands are compared to those of uranocene in THF and thorocene. All vibrational frequencies of the ligands, ...

2004-02-08

208

Raman Under Nitrogen. The High-Resolution Raman Spectroscopy of Crystalline Uranocene, Thorocene, and Ferrocene  

International Nuclear Information System (INIS)

The utility of recording Raman spectroscopy under liquid nitrogen, a technique we call Raman Under Nitrogen (RUN), is demonstrated for ferrocene, uranocene and thorocene. Using RUN, low temperature (liquid nitrogen cooled) Raman spectra for these compounds exhibit higher resolution than previous studies and new vibrational features are reported. The first Raman spectra of crystalline uranocene at 77 K are reported using excitation from argon (5145 ) and krypton (6764 ) ion lasers. The spectra obtained showed bands corresponding to vibrational transitions at 212, 236, 259, 379, 753, 897, 1500, and 3042 cm-1 , assigned to ring-metal-ring stretching, ring-metal tilting, out-of-plane CCC bending, in-plane CCC bending, ring-breathing, C-H bending, CC stretching and CH stretching, respectively. The assigned vibrational bands are compared to those of uranocene in THF and thorocene. All vibrational frequencies of the ligands, ...

2004-02-08

209

Preparation and Properties of Antibodies against Indoleacetic Acid (IAA)-C5-BSA, a Novel Ring-Coupled IAA Antigen, as Compared to Two Other Types of IAA-Specific Antibodies 1  

UK PubMed Central (United Kingdom)

Two types of indoleacetic acid (IAA) antigens have been described in the literature which show marked differences with respect to antibody specificity. In this communication an alternative antigen design...Full Text Available

1989-04-01

210

Pipe behaviour in bottom ash slurry systems  

Energy Technology Data Exchange (ETDEWEB)

This study presents the results of an 18-year long investigation of pipe deterioration in cyclone slag slurry transport. The goal was to study pipe behaviour in this extremely abrasive service and select an optimum piping material. Comparisons are given for high quality alloy cast steel pipes and pipes alined with cast basalt rings marketed under the name Abresist.

1982-09-01

211

Pipe behaviour in bottom ash slurry systems  

Energy Technology Data Exchange (ETDEWEB)

This study presents the results of an 18-year long investigation of pipe deterioration in cyclone slag slurry transport. The goal was to study pipe behaviour in this extremely abrasive service and select an optimum piping material. Comparisons are given for high quality alloy cast steel pipes and pipes lined with cast basalt rings marketed under the name Abresist. Based on the results, thoughts are offered on the broader meanings of certain findings.

1982-09-01

212

Photon storage cavities  

Energy Technology Data Exchange (ETDEWEB)

A general analysis is presented of a photon storage cavity, coupled to free-electron laser (FEL) cavity. It is shown that if the coupling between the FEL cavity and the storage cavity is unidirectional (for example, a ring resonator storage cavity) then storage is possible, but that if the coupling is bi-directional then storage is not possible. Parameters are presented for an infra-red FEL storage cavity giving an order of magnitude increase in the instantaneous photon power within the storage cavity. 4 refs., 3 figs.

1991-08-01

213

P and e identification capabilities CAPRICE  

Energy Technology Data Exchange (ETDEWEB)

The cosmic antiparticle ring imaging Cherenkov experiment (CAPRICE) flew on a stratospheric balloon 8-9 August 1994 over northern Canada and collected data for more than 21 hours with less than 5 g/cm{sup 2} of residual atmosphere. The instrument includes a solid radiator RICH detector and an electromagnetic calorimeter for particle identification in the magnetic spectrometer. Preliminary antiproton and positron identification capabilities are presented.

1995-09-01

214

News from Smithers Rapra  

Wastenet

...of Mixing Sections 9 Interacting Rotor/Stator Mixers 10 Floating Ring Mixing Devices 11 Static (or Motionless) Mixers 12 Incorporation of Liquid Additives and Dispersions by Direct Addition 13 Dispersive Mixing of Fillers and Pigments 14 Dispersive Mixing Applied to Polymer Blending 15 Compounding with Single Screw Extruders Appendix - Preparation of Microtome Sections for Assessment of Dispersive In order to get a feel for this book, you can view Chapter 1 now, simply follow the link ...

215

Nanophotonic components utilizing channel plasmon polaritons  

Science.gov (United States)

Channel plasmon polaritons (CPPs) propagating along the bottom of subwavelength grooves cut into a metal surface were recently shown to exhibit strong confinement combined with low propagation loss, a feature that makes this guiding configuration very promising for the realisation of ultra-compact photonic components. Here, the results of our investigations of CPP guiding by V-grooves cut into gold are presented, demonstrating efficient large-angle bending and splitting of radiation as well as waveguide-ring resonators and Bragg grating filters.

2008-08-01

216

Multi-mirror system, 2. Application of inverse Compton Scattering for lithography X-ray sources  

Energy Technology Data Exchange (ETDEWEB)

A brilliant X ray source is proposed for lithography instruments with use of a multi-mirror system. The inverse Compton scattering between the stored electron beam in the storage ring and the stored photon beam in the multi-mirror system, is applied for the X-ray generation. (author)

2000-07-01

217

Metabolism of 4-chloro-2-methylphenoxyacetate by a soil pseudomonad. Ring-fission, lactonizing and delactonizing enzymes  

UK PubMed Central (United Kingdom)

1. A cell-free system, prepared from Pseudomonas N.C.I.B. 9340 grown on 4-chloro-2-methylphenoxyacetate (MCPA) was shown to catalyse the reaction sequence: 5-chloro-3-methylcatechol...Full Text Available

1971-05-01

218

Measurements of Cabibbo Suppressed Hadronic Decay Fractions of Charmed D0 and D+ Mesons  

CERN Document Server

Using data collected with the BESII detector at $e^{+}e^{-}$ storage ring Beijing Electron Positron Collider, the measurements of relative branching fractions for seven Cabibbo suppressed hadronic weak decays $D^0 \\to K^- K^+$, $\\pi^+ \\pi^-$, $K^- K^+ \\pi^+ \\pi^-$ and $\\pi^+ \\pi^+ \\pi^- \\pi^-$, $D^+ \\to \\bar{K^0} K^+$, $K^- K^+ \\pi^+$ and $\\pi^- \\pi^+ \\pi^+$ are presented.

2005-01-01

219

Laser-induced fluorescence measurement of sup(6,7)lithium isotope shift  

Energy Technology Data Exchange (ETDEWEB)

Values of frequency splittings in the lithium isotopes have been determined with the aid of laser-induced fluorescene in a supersonic beam, perpendicularly irradiated by a CW ring dye laser. The residual 2s-2p isotope shift has been found to bw 4721.8 +- 2.0 MHz, leading to a specific mass shift for the 2p level of -3610.8 +- 5 MHz.

1986-07-01

220

Incidental Findings in Genetics Research Using Archived DNA  

UK PubMed Central (United Kingdom)

You were a patient at Hospital A several years ago when you were suffering from disease X, which has long since resolved. You have just arrived home from a long day's work when the phone rings....Full Text Available

2008-01-01

221

Hyperbolicity of Semigroup Algebras II  

CERN Document Server

In 1996 Jespers and Wang classified finite semigroups whose integral semigroup ring has finitely many units. In a recent paper, Iwaki-Juriaans-Souza Filho continued this line of research by partially classifying the finite semigroups whose rational semigroup algebra %over a field of characteristic zero, contains a ${\\mathbb{Z}}$-order with hyperbolic unit group. In this paper we complete this classification by handling the case in which the semigroup is semi-simple.

2008-01-01

222

HELIUM FLOW INDUCED ORBIT JITTER AT RHIC.  

Energy Technology Data Exchange (ETDEWEB)

Horizontal beam orbit jitter at frequencies around 10 Hz has been observed in RHIC for several years. The distinct frequencies of this jitter have been found at superconducting low-beta quadrupole triplets around the ring, where they coincide with mechanical modes of the cold masses. Recently, we have identified liquid helium flow as the driving force of these oscillations.

2005-05-16

223

Forschungszentrum Juelich, Institut fuer Kernphysik. Annual report 1994  

Energy Technology Data Exchange (ETDEWEB)

This volume contains the annual report describing the work carried out at COSY (Cooled Synchrotron Storage Ring at KFA Juelich). The results in both machine and physics program are presented on the main topics experimental nuclear physics, theoretical nuclear physics, accelerator developments and technical developments. (MSA)

1995-02-01

224

Domain structure of ferrite-garnet crystalline plates (111) with uniaxial anisotropy  

Energy Technology Data Exchange (ETDEWEB)

Magnetic field, thickness and magnetic forming effect on general mode and quantitative parameters of the domain structure (DS) of ferrite-garnet (EuEr)/sub 3/(FeGa)/sub 5/O/sub 12/ monocrystalline plates (111) is investigated. Field interval of circle (cone) and ring domain stability is determined. It is shown that DS of ferrite-garnet crystals with uniaxial an6sotropy has some peculiarities, that can be explained by cubic anisotropy effect.

1982-03-01

225

Disk's Spiral Arms Point to Possible Planets  

National Aeronautics and Space Administration (NASA)

Simulations of young stellar systems suggest that planets embedded in a circumstellar disk can produce many distinctive structures, including rings, gaps and spiral arms. This video compares computer simulations of hypothetical systems to an image of system SAO 206462 taken by the Subaru Telescope and its HiCIAO instrument. n nCredit: NASA Goddard Space Flight Center/NCSA

2011-10-18

226

Digital signal processing for beam position feedback  

Energy Technology Data Exchange (ETDEWEB)

Stabilization of the particle beam position with respect to the focusing optics in the third generation synchrotron light sources is crucial to achieving low emittance and high brightness. For this purpose, global and local beam orbit correction feedbacks will be implemented in the APS storage ring. In this article, the authors discuss application of digital signal processing to particle/photon beam position feedback using the PID (proportional, integral, and derivative) control algorithm.

1992-04-01

227

Details about emission sources for IMF's in heavy ion collisions  

International Nuclear Information System (INIS)

A large IMF- and event characterizing multidetector system (CHICSI) is under development for storage ring experiments. In ''test'' experiments with telescopes of CHICSI type the IMF production has been measured for "1"4N induced reactions at 14A and 32A MeV. Detailed information about the emission sources, particularly from the IMF yield in reactions with isotope separated targets and from isobaric yield ratios in the sub-Coulomb region is discussed. (orig.).

1994-01-17

228

Container for the long-term storage of radioactive substances with a lid tightening device  

International Nuclear Information System (INIS)

The invention concerns a container for the long term storage of irradiated nuclear reactor fuel elements, which consists mainly of a basic body, at least one lid and an outside ring shaped lid tightening device, which acts on the basic body and the lid and holds the contact surface of the lid tight against the contact surface of the basic body, where the basic body, lid and the lid tightening device consist of corrosion-proof materials. (orig./HP).

1983-09-24

229

Coal liquefaction catalzsed by iron ores. Catalytic activities of laterite ores  

Energy Technology Data Exchange (ETDEWEB)

The catalytic activities of various iron ores were investigated in the search for a high-activity catalyst for direct coal liquefaction. Laterite ores were shown to have a high catalytic activity in this process. Comparison of the ore with red mud in hydrocracking of 1-methylnaphthalene showed that the ore had higher activity in the hydrogenation of aromatic rings and in hydrocracking of alkylaromatics.

1984-10-01

230

Calcium fluoride window mounting  

International Nuclear Information System (INIS)

A technique has been developed for joining a large calcium fluoride crystal to a stainless-steel flange by means of a silver transition ring. The process involves both vacuum brazing using a copper-silver alloy and air brazing using silver chloride. This paper describes the procedure used in fabricating a high-vacuum leak-tight calcium fluoride window assembly.

231

An improved method for hyaluronic acid radioiodination  

Energy Technology Data Exchange (ETDEWEB)

A simple procedure is described for preparing {sup 125}I-labelling hyluronan of high molecular weight. The reducing terminal group of hyaluronic acid was derivatized with tyramine through the formation of a Schiff base which was subsequently reduced with sodium cyanoborohydride. By radioiodination of the aromatic ring, {sup 125}I-labelled hyaluronic acid was obtained in high yield (40%) and high specific activity, 555 GBq/mmol (15 Ci/mmol). (Author).

1995-09-01

232

A new species of Demidospermus (Platyhelminthes, Monogenea, Ancyrocephalidae) from the catfish Parapimelodus valenciennis in Samboromb?n Bay, Argentina  

British Library Electronic Table of Contents (United Kingdom)

Demidospermus annulus sp. nov. (Platyhelminthes, Monogenea, Ancyrocephalidae) is described from the gills of the catfish Parapimelodus valenciennis L?tken collected in Samboromb?n Bay, Argentina. The new species differs from all congeneric species mainly by the structure of the accessory piece of the male copulatory organ, the sclerotized ring-shaped vaginal aperture and the dorsal bar articulation.

2011-01-01

233

Simulation of non-linear and switching elements for transient analysis based on wave digital filters  

Science.gov (United States)

A previous paper introduced the use of wave digital filters as a basic building block for power system simulation, particularly suitable for real-time applications. This paper stresses the simulation of non-linear and switching elements, emphasizing the advantages of the wave filters implementation. The digital structure is maintained even when non-linear components change their characteristics or power electronic devices switch their states. As a very important by-product, the suppression of numerical oscillations related to the trapezoidal rule is achieved in a rather simple way, with no effects on simulation results.

1996-10-01

234

Optimization technique for the design of a linear optimal power system stabilizer  

Energy Technology Data Exchange (ETDEWEB)

A systematic optimization method of choosing the weighting matrix in linear optimal control system design, under the conditions of prespecified closed-loop dominant eigenvalue locations and feedback gain limit constraints, is presented in this paper. Studies show that with the proposed method one can obtain the desired weighting matrix very quickly and conveniently without the heavy burden of choosing a suitable weighting matrix by trail and error. This method can also easily achieve a reduced-order feedback control system. The linear optimal power system stabilizer designed by using the proposed method produces very good performance.

1992-09-01

235

H-convergence for quasi-linear elliptic equations under natural hypotheses on the correctors  

International Nuclear Information System (INIS)

In this paper we study the behavior of the solutions of quasi-linear Dirichlet problems when the principal parts H-converge and when the lower order terms have quadratic growth with respect to the gradient. We show that the limit problem consists of a principal part which is the H-limit of the principal parts and of the lower order term which is constructed from the corresponding terms by using a linear corrector result. We assume only natural hypotheses on the correctors (i.e. L"2 equi-integrability and not L"#infinity# boundedness). (author)

236

Comparison of the TESLA, NLC and CLIC Beam-Collimation System Performance  

CERN Document Server

This report describes studies performed in the framework of the Collimation Task Force organized to support the work of the second International Linear Collider Technical Review Committee. The post-linac beam-collimation systems in the TESLA, JLC/NLC and CLIC linear-collider designs are compared using the same computer code under the same assumptions. Their performance is quantified in terms of beam-halo and synchrotron-radiation collimation efficiency. The performance of the current designs varies across projects, and does not always meet the original design goals. But these comparisons suggest that achieving the required performance in a future linear collider is feasible.

2004-01-01

237

Charged particles background due to electromagnetic processes at the VLEPP based Photon Linear Collider with ultimate luminosity  

Energy Technology Data Exchange (ETDEWEB)

We have made preliminary estimates of charged particles background at the 100x100 GeV Photon Linear Collider with ultimate luminosity. The charged particles background due to electromagnetic processes is located mainly in the small-angle range of the detector. At large angles, the number of background particles is much smaller. Analysis of the background (at least, in the range under consideration) shows that background conditions for the VLEPP-based Photon Linear Collider are better than at the VLEPP electron-positron collider. ((orig.)).

1995-02-01

238

Asymptotic functions of many variables and singular operations with Schwartz distributions  

International Nuclear Information System (INIS)

A theory of the asymptotic functions for the case of many variables is presented. It is shown that the class F(R"N) of these generalized functions is closed in respect to the linear algebraic and analytic operations, multiplication as well as a set of linear and polynomial changes of the variables. The existence in F(R"N) of analogues (consistent with the linear operations) of the Schwartz distributions with point support is proved. In terms of these analogues, some formulae for singular products and changes of variables of the Dirac #delta#-function and its derivatives #delta#"("i")(x), x is an element of R"N, are given. (author). 14 refs.

1992-10-19

239

tfrsc fa so - NASA Technical Report Server (NTRS)  

Science.gov (United States)

pletely new PW fuel cell model had to be developed for CINDA. Several ...... following linear equation, which is used in the SINDA fuel cell model: ...

240

Why the US should spend billions on a new particle accelerator  

CERN Multimedia

"The US must develop a compelling bid to host the International Linear Collider in order to safeguard American science." (1,5 page)

2006-01-01

241

The Stefan problem solved via conjugate gradient-like iterative methods on a parallel vector machine  

Science.gov (United States)

The aim of this paper is to illustrate the validity and efficiency of iterative methods for solving large linear systems arising from the finite element discretization of the equation governing conduction-controlled solidification processes. Starting from the basic enthalpy equation, two alternative formulations are obtained and fixed-grid finite element discretizations are developed. These discretizations yield a set of nonlinear equations that are linearized using the Newton-Raphson scheme. The linearized equations are used as a basis for evaluating different iterative methods of the conjugated gradient type. Symmetric scaling and incomplete factorization preconditioning of the linear equations are used to improve the convergence properties of the iterative methods. Vectorization and parallelization are also employed to make full use of the CRAY-2 supercomputer. The results indicate that the ...

1991-01-01

242

Technical Report Series on the Boreal Ecosystem-Atmosphere Study ...  

Science.gov (United States)

A floating boardwalk was constructed from the shore to ...... Irrespective of whether we could tie the outlier to a cause, a simple linear interpolation was ...

243

Subspace estimation and prediction methods for hidden Markov models  

CERN Document Server

Hidden Markov models (HMMs) are probabilistic functions of finite Markov chains, or, put in other words, state space models with finite state space. In this paper we examine subspace estimation methods for HMMs whose output lies a finite set as well. In particular we study the geometric structure arising from the non-minimality of the linear state space representation of HMMs, and consistency of a subspace algorithm arising from a certain factorisation of the singular value decomposition of the estimated linear prediction matrix. For this algorithm we show that the estimates of the transition and emission probability matrices are consistent up to a similarity transformation, and that the m-step linear predictor computed from the estimated system matrices is consistent, i.e. converges to the true optimal linear m-step predictor.

2009-01-01

244

Studies of Non-Linear Optical Effects for Agile Beam Steering  

Science.gov (United States)

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

1993-11-01

245

Spherical redshift distortions  

CERN Document Server

Peculiar velocities induce apparent line of sight displacements of galaxies in redshift space, distorting the pattern of clustering in the radial versus transverse directions. On large scales, the amplitude of the distortion yields a measure of the dimensionless linear growth rate \\ff of fluctuations, which is related to the cosmological density \\Omega and the linear bias factor b in linearly biassed standard cosmology by \\ff \\approx \\Omega^{0.6} /b. To make the maximum statistical use of the data in a wide angle redshift survey, and for the greatest accuracy, the spherical character of the distortion needs to be treated properly, rather than in the simpler plane parallel approximation. In the linear regime, the redshift space correlation function is described by a spherical distortion operator acting on the true correlation function. It is pointed out here that there exists an operator, which is ...

1995-01-01

246

Saturation effects at LHC energies  

CERN Document Server

Within the framework of a modified Balitsky-Kovchegov equation, we calculated and provide estimates of non-linear saturation effects expected in the LHC range of energies.

2005-01-01

247

Research on optimizing pass schedule of tandem cold mill  

Energy Technology Data Exchange (ETDEWEB)

In this paper, research on pass schedule of tandem cold mill (TCM) is carried out. According to load (reduction, rolling force, motor power) balance, non-linear equations set with variables of inter-stand thickness is constructed. The pass schedule optimization is carried out by solving the non-linear equations set. As the traditional method, the Newton-Raphson method is used for solving the non-linear equations set. In this paper a new simple method is brought up. On basis of the monotone relations between thickness and load, the inter-stands thickness is adjusted dynamically. The solution of non-linear equations set can be converged by iterative calculation. This method can avoid the derivative calculation used by traditional method. So, this method is simple and calculation speed is high. It is suitable for on-line control. (author)

2000-07-01

248

Research on optimizing pass schedule of tandem cold mill  

International Nuclear Information System (INIS)

In this paper, research on pass schedule of tandem cold mill (TCM) is carried out. According to load (reduction, rolling force, motor power) balance, non-linear equations set with variables of inter-stand thickness is constructed. The pass schedule optimization is carried out by solving the non-linear equations set. As the traditional method, the Newton-Raphson method is used for solving the non-linear equations set. In this paper a new simple method is brought up. On basis of the monotone relations between thickness and load, the inter-stands thickness is adjusted dynamically. The solution of non-linear equations set can be converged by iterative calculation. This method can avoid the derivative calculation used by traditional method. So, this method is simple and calculation speed is high. It is suitable for on-line control. (author)

2000-08-20

249

Propulsion and Power Rapid Response R&D Support ...  

Science.gov (United States)

... Results of the AXI5345-18 Motor, Jeti Spin 99 Controller and the APC 27 x 13 Propeller in use with a Linearized Fuel Cell Model Assuming Voc ...

2008-12-01

250

Optimization for Vibration Isolation.  

Science.gov (United States)

An almost linear optimization problem of importance in vibration isolation has been identified and algorithms were developed to minimize the forced vibrational response of structural systems. The constraints can be either displacements of accelerations. T...

1983-01-01

252

Linearization effect in multifractal analysis: Insights from Random Energy Model analysis  

CERN Document Server

The analysis of the linearization effect in multifractal analysis, and hence of the estimation of moments for multifractal processes, is revisited borrowing concepts from the statistical physics of disordered systems, notably from the analysis of the so-called Random Energy Model. Considering a standard multifractal process (compound Poisson motion), chosen as a simple representative example, we show: i) the existence of a critical order q* beyond which moments, though finite, cannot be estimated through empirical averages, irrespective of the sample size of the observation; ii) that multifractal exponents necessarily behave linearly in q, for q > q*. Tailoring the analysis conducted for the Random Energy Model to that of Compound Poisson motion, we provide explicative and quantitative predictions for the values of q* and for the slope controlling the linear behavior of the multifractal exponents. These quantities are ...

2010-01-01

253

Inverse Scattering and Applications. Proceedings of ...  

Science.gov (United States)

... Richrd Bals andLina PrissJames Lepowsky and Mirko Primc Richard Beaals, and Linda Preiss Rothschild, Editors 47 Linear algebra and its role in ...

2011-05-14

255

Implementation of projective measurements with linear optics and continuous photon counting  

International Nuclear Information System (INIS)

We investigate the possibility of implementing a given projection measurement using linear optics and arbitrarily fast feedforward based on the continuous detection of photons. In particular, we systematically derive the so-called Dolinar scheme that achieves the minimum-error discrimination of binary coherent states. Moreover, we show that the Dolinar-type approach can also be applied to projection measurements in the regime of photonic-qubit signals. Our results demonstrate that for implementing a projection measurement with linear optics, in principle, unit success probability may be approached even without the use of expensive entangled auxiliary states, as they are needed in all known (near-)deterministic linear-optics proposals.

2005-02-01

256

Identification and robust water level control of horizontal steam generators using quantitative feedback theory  

British Library Electronic Table of Contents (United Kingdom)

In this paper, a robust water level control system for the horizontal steam generator (SG) using the quantitative feedback theory (QFT) method is presented. To design a robust QFT controller for the nonlinear uncertain SG, control oriented linear models are identified. Then, the nonlinear system is modeled as an uncertain linear time invariant (LTI) system. The robust designed controller is applied to the nonlinear plant model. This nonlinear model is based on a locally linear neuro-fuzzy (LLNF) model. This model is trained using the locally linear model tree (LOLIMOT) algorithm. Finally, simulation results are employed to show the effectiveness of the designed QFT level controller. It is shown that it will ensure the entire designer's water level closed loop specifications.

2011-01-01

257

Generalized Linear Models in Family Studies  

Science.gov (United States)

Generalized linear models (GLMs), as defined by J. A. Nelder and R. W. M. Wedderburn (1972), unify a class of regression models for categorical, discrete, and continuous response variables. As an extension of classical linear models, GLMs provide a common body of theory and methodology for some seemingly unrelated models and procedures, such as the logistic, Poisson, and probit models, that are increasingly used in family studies. This article provides an overview of the principle and the key components of GLMs, such as the exponential family of distributions, the linear predictor, and the link function. To illustrate the application of GLMs, this article uses Canadian national survey data to build an example focusing on the number of close friends among older adults. The article concludes with a discussion of the strengths and weaknesses of GLMs.

2005-11-01

258

DMSP Special Sensor Microwave/Imager Calibration ...  

Science.gov (United States)

... Using a weighted linear regression on randomly selected coincident SSM/I-buoy pairs from each of the climate m codes, it was possible to produce ...

2011-05-14

259

Aeroelastic Analysis by Coupled Non-linear Time Domain ... - NASA  

Science.gov (United States)

and shock induced flow separation may significantly affect the flutter ...... Aerodynamic and Aeroelastic Simulation, AGARD Report 822, 10-1 10-20. ...

260

Subordination and superordination for multivalent functions defined by linear operators  

CERN Document Server

In this paper, certain linear operators defined on $p$-valent analytic functions have been unified and for them some subordination and superordination results as well as the corresponding sandwich type results are obtained. A related integral transform is discussed and sufficient conditions for functions in different classes have been obtained.

2011-01-01

261

Strong WW scattering at photon linear colliders  

Energy Technology Data Exchange (ETDEWEB)

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.)).

1995-02-01

262

Strong WW scattering at photon linear colliders  

Energy Technology Data Exchange (ETDEWEB)

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.

1994-06-01

263

On the Field Dependent Surface Resistance Observed in Superconducting Niobium Cavities  

CERN Document Server

A quantitative description is presented of the non-linear current-voltage response in superconducting niobium cavities for accelerator application. It is based on a fit for a large sample of data from cavity tests of different kind. Trial functions for the surface resistance describing this non-linear relation are established by a least square data fit. Those trial functions yielding the best fit are quantitatively explained by basic physics.

2009-01-01

264

Non-linearity of pre-dose response and its effects on TL dating  

Energy Technology Data Exchange (ETDEWEB)

Analytical expressions for thermoluminescence (TL) dating based on the modified Zimmerman model were derived. The non-linear behaviour of TL sensitivity is reexamined and is found to be due to electron capturing competitions in both test-dose excitation and the readout stages. A curve fitting method is proposed to determine the paleodose for the additive dose dating method. The multiple activation technique is also investigated, from which the paleodose should be regarded as an upper limit.

2009-03-15

265

Non-linearity of pre-dose response and its effects on TL dating  

International Nuclear Information System (INIS)

Analytical expressions for thermoluminescence (TL) dating based on the modified Zimmerman model were derived. The non-linear behaviour of TL sensitivity is reexamined and is found to be due to electron capturing competitions in both test-dose excitation and the readout stages. A curve fitting method is proposed to determine the paleodose for the additive dose dating method. The multiple activation technique is also investigated, from which the paleodose should be regarded as an upper limit.

2009-03-01

266

Modulation instability of linearly polarized laser pulse in relativistic plasma  

International Nuclear Information System (INIS)

Based on the nonlinear dispersion relation of electromagnetic wave in relativistic plasma, the nonlinear controlling equation for linearly polarized mode is obtained using Karpman's method. The modulation instability of intense laser pulse propagating through relativistic plasma is analyzed and the modulation instability growth rate as a function of perturbation wave number for laser beam propagating through relativistic plasma is given. (authors)

2008-10-01

267

Main stages of a physical program for e{gamma} and {gamma}{gamma} colliders  

Energy Technology Data Exchange (ETDEWEB)

We discuss the main stages of a physical program for photon linear colliders. We consider the problems in electroweak theory, hadron physics, QCD, and nonlinear QED, as well as new particles and interactions, etc. The discussed stages constitute the parts of an entire ambitious program for linear colliders. ((orig.)).

1995-02-01

268

Interaction region layout of the VLEPP based photon linear collider with ultimate luminosity  

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.)).

1995-02-01

269

Infinitesimal symmetries and conservation laws of the DNLSE hierarchy and the Noether's theorem  

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)

2007-08-15

270

Implementation and laboratory test results for an adaptive Power System Stabilizer based on linear optimal control  

Energy Technology Data Exchange (ETDEWEB)

Implementation of an adaptive power system stabilizer (PSS) based on linear optimal control is described in this paper. The generator is identified in real time, and a special 3rd order discrete Riccati equation is solved in each sample interval. Because the output of the generator is fed back directly, the controller can track the system very fast. Experimental studies on a physical model of a power system demonstrate the effectiveness of the proposed adaptive optimal controller.

1990-12-01

271

Early Experience in Using an 18 MeV Linear Accelerator for Mycosis Fungoides at Howard University Hospital  

UK PubMed Central (United Kingdom)

This paper describes the problems and solutions in using 18 MeV linear accelerator, with minimum 6 MeV electron capability, for total skin irradiation for mycosis fungoides. The 6 MeV electron energy...Full Text Available

1977-04-01

272

Composite vector leptoquarks in e"+e-, #gamma#e, and #gamma##gamma# colliders  

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.

273

Accelerating the convergence of self-consistent linearized augmented-plane-wave calculations  

International Nuclear Information System (INIS)

The applicability of Broyden's second method for accelerating the convergence of self-consistent electronic-structure calculations based on the linearized augmented-plane-wave method is discussed in terms of a W(001) surface calculation. It is found that its use results in a significant improvement in the convergence of the calculation, and based on this it is concluded that its use should increase the size of the systems for which such calculations are feasible.

274

A quantum-statistical-mechanical extension of Gaussian mixture model  

Energy Technology Data Exchange (ETDEWEB)

We propose an extension of Gaussian mixture models in the statistical-mechanical point of view. The conventional Gaussian mixture models are formulated to divide all points in given data to some kinds of classes. We introduce some quantum states constructed by superposing conventional classes in linear combinations. Our extension can provide a new algorithm in classifications of data by means of linear response formulas in the statistical mechanics.

2008-01-15

275

Safety assessment and life time management of nuclear power plants: from reasonable design to reliable structural health monitoring  

International Nuclear Information System (INIS)

Nowadays the safety of Nuclear Power Plants is becoming more and more significant. Therefore consideration of severe accidents shall be included in both design and operating process of Nuclear Power Plants. In particular ground motion forms one of the important natural hazards. For structural analysis both linear-elastic and non-linear methods are specified by the engineering codes for earthquake resistance design. However, time history analysis is required for investigation of non-linear structural behaviour. Moreover, non-linearities are often caused by the presence of damage. This can be detected by means of structural health monitoring and subsequently system identification. In this paper the advantages of both dynamic time history analysis and damage detection by means of wavelet analysis are discussed. First, the non-linear behaviour of a frame structure due to an artificial ...

2005-06-15

276

Predicting neuronal responses during natural vision.  

Science.gov (United States)

A model that fully describes the response properties of visual neurons must be able to predict their activity during natural vision. While many models have been proposed for the visual system, few have ever been tested against this criterion. To address this issue, we have developed a general framework for fitting and validating nonlinear models of visual neurons using natural visual stimuli. Our approach derives from linear spatiotemporal receptive field (STRF) analysis, which has frequently been used to study the visual system. However, prior to the linear filtering stage typical of STRFs, a linearizing transformation is applied to the stimulus to account for nonlinear response properties. We used this approach to compare two models for neurons in primary visual cortex: a nonlinear Fourier power model, which accounts for spatial phase invariant tuning, and a traditional linear model. We characterized ...

277

PDE-based Non-Linear Diffusion Techniques for Denoising Scientific and Industrial Images: An Empirical Study  

Energy Technology Data Exchange (ETDEWEB)

Removing noise from data is often the first step in data analysis. Denoising techniques should not only reduce the noise, but do so without blurring or changing the location of the edges. Many approaches have been proposed to accomplish this; in this paper, they focus on one such approach, namely the use of non-linear diffusion operators. This approach has been studied extensively from a theoretical viewpoint ever since the 1987 work of Perona and Malik showed that non-linear filters outperformed the more traditional linear Canny edge detector. They complement this theoretical work by investigating the performance of several isotropic diffusion operators on test images from scientific domains. They explore the effects of various parameters such as the choice of diffusivity function, explicit and implicit methods for the discretization of the PDE, and approaches for the spatial discretization of the ...

2001-12-20

278

Linearized Schroedinger equation for nuclear quadrupole surface vibrations  

Energy Technology Data Exchange (ETDEWEB)

The Schroedinger equation for nuclear quadruple surface vibrations is linearized with the consequence that a new spin degree of freedom appears in the wave function of the linearized equation. This spin is called collective spin and has a value of 3/2. The linearized Schroedinger equation for quadrupole vibrations is used for the description of certain collective aspects of even-odd {sup 187,189,191}Ir nuclei which have a spin 3/2 in their ground state. As a potential we use the {gamma}-soft collective potential of the neighboring even-even nuclei, which is inserted into the linearized Schroedinger equation via a scalar coupling. This leads to a collective spin-dependent fine structure splitting of the energy levels governed by a collective SO(5) spin-orbit coupling and a correction to the kinetic energy. Further, we consider explicitly spin-dependent potentials which effectively describe the ...

1990-07-01

279

Linearized Schroedinger equation for nuclear quadrupole surface vibrations  

International Nuclear Information System (INIS)

The Schroedinger equation for nuclear quadruple surface vibrations is linearized with the consequence that a new spin degree of freedom appears in the wave function of the linearized equation. This spin is called collective spin and has a value of 3/2. The linearized Schroedinger equation for quadrupole vibrations is used for the description of certain collective aspects of even-odd "1"8"7","1"8"9","1"9"1Ir nuclei which have a spin 3/2 in their ground state. As a potential we use the #gamma#-soft collective potential of the neighboring even-even nuclei, which is inserted into the linearized Schroedinger equation via a scalar coupling. This leads to a collective spin-dependent fine structure splitting of the energy levels governed by a collective SO(5) spin-orbit coupling and a correction to the kinetic energy. Further, we consider explicitly spin-dependent potentials which effectively describe the ...

280

Half-trek criterion for generic identifiability of linear structural equation models  

CERN Document Server

A linear structural equation model relates random variables of interest and corresponding Gaussian noise terms via a linear equation system. Each such model can be represented by a mixed graph in which directed edges encode the linear equations, and bidirected edges indicate possible correlations among noise terms. We study parameter identifiability in these models, that is, we ask for conditions that ensure that the edge coefficients and correlations appearing in a linear structural equation model can be uniquely recovered from the covariance matrix of the associated normal distribution. We treat the case of generic identifiability, where unique recovery is possible for almost every choice of parameters. We give a new graphical criterion that is sufficient for generic identifiability. It improves criteria from prior work and does not require the directed part of the graph to be acyclic. We also develop ...

2011-01-01

281

Faster Approximate Lossy Generalized Flow via Interior Point Algorithms  

CERN Document Server

We present faster approximation algorithms for generalized network flow problems. A generalized flow is one in which the flow out of an edge differs from the flow into the edge by a constant factor. We limit ourselves to the lossy case, when these factors are at most 1. Our algorithm uses a standard interior-point algorithm to solve a linear program formulation of the network flow problem. The system of linear equations that arises at each step of the interior-point algorithm takes the form of a symmetric M-matrix. We present an algorithm for solving such systems in nearly linear time. The algorithm relies on the Spielman-Teng nearly linear time algorithm for solving linear systems in diagonally-dominant matrices. For a graph with m edges, our algorithm obtains an additive epsilon approximation of the maximum generalized flow and minimum cost generalized flow in time tildeO(m^(3/2) ...

2008-01-01

282

An effective method for the linearization of nodal stress components to apply ASME criteria  

Energy Technology Data Exchange (ETDEWEB)

The code of ASME Sec. III prescribes the general rules upon the design of a NSSS (nuclear steam supply system). The code provides further flexibility to the design of the nuclear structures by introducing a design by analysis concept. But it still preserves the conservatisms in design works by imposing strict failure mechanism and controlling material properties in use. A designer should prove the integrity of a structure under consideration by comparing the stress intensity, which was driven from the linearization of stress at concerning section, with the prescribed one. The recent development in computing system has enabled the commercial finite element programs to be a prevailing way to structural analysis field. But only few programs provide the procedure for stress linearization through the post-processing stage. Therefore, the simplified method which uses nodal stresses over the concerning section is introduced instead. But the issues ...

2002-02-01

283

UHRF1, a modular multi-domain protein, regulates replication-coupled crosstalk between DNA methylation and histone modifications  

Science.gov (United States)

Cytosine methylation in DNA is a major epigenetic signal, and plays a central role in propagating chromatin status during cell division. However the mechanistic links between DNA methylation and histone methylation are poorly understood. A multi-domain protein UHRF1 (ubiquitin-like, containing PHD and RING finger domains 1) is required for DNA CpG maintenance methylation at replication forks, and mouse UHRF1-null cells show enhanced susceptibility to DNA replication arrest and DNA damaging agents. Recent data demonstrated that the SET and RING associated (SRA) domain of UHRF1 binds hemimethylated CpG and flips 5-methylcytosine out of the DNA helix, whereas its tandom tudor domain and PHD domain bind the tail of histone H3 in a highly methylation sensitive manner. We hypothesize that UHRF1 brings the two components (histones and DNA) carrying appropriate markers (on the tails of H3 and hemimethylated CpG sites) ready to be assembled into a ...

2009-01-01

284

The viscous overstability, nonlinear wavetrains, and finescale structure in dense planetary rings  

CERN Document Server

This paper addresses the fine-scale axisymmetric structure exhibited in Saturn's A and B-rings. We aim to explain both the periodic microstructure on 150-220m, revealed by the Cassini UVIS and RSS instruments, and the irregular variations in brightness on 1-10km, reported by the Cassini ISS. We propose that the former structures correspond to the peaks and troughs of the nonlinear wavetrains that form naturally in a viscously overstable disk. The latter variations on longer scales may correspond to modulations and defects in the wavetrains' amplitudes and wavelength. We explore these ideas using a simple hydrodynamical model which captures the correct qualitative behaviour of a disk of inelastically colliding particles, while also permitting us to make progress with analytic and semi-analytic techniques. Specifically, we calculate a family of travelling nonlinear density waves and determine their stability properties. Detailed numerical simulations that confirm our ...

2009-01-01

285

Si3C2-rings: from a nonconjugated trisilacyclopentadiene to an aromatic trisilacyclopentadienide and cyclic disilenide.  

Science.gov (United States)

1,2,3-Trisilacyclopenta-1,4-diene 2, featuring three skeletal Si atoms in the five-membered ring, was synthesized by the thermolysis of the 1,2,3-trisilabicyclo[1.1.0]butane derivative 1 at 130 degrees C in the presence of hex-3-yne. Possessing the properties of nonconjugated cyclopentadiene, 2 readily underwent reduction with KC(8), which was followed by treatment with LiBr to form the lithium salt of 1,2,3-trisilacyclopentadienide 3(-)*[Li(+)(thf)], from which the ketone-coordinated derivative 3(-)*[Li(+)(O=C(t)Bu(2))] was prepared. Both 3(-)*[Li(+)(L)] (L = thf, O=C(t)Bu(2)) are classified as novel 6pi-electron aromatic systems based on their characteristic X-ray crystal and NMR spectral data. Addition of 12-crown-4 to 3(-)*[Li(+)(thf)] resulted in the unexpected formation of 4(-)*[Li(+)(12-crown-4)(2)], featuring the unprecedented cyclic disilenide ion 4(-). PMID:19378994

2009-05-13

286

Rice RING protein OsBBI1 with E3 ligase activity confers broad-spectrum resistance against Magnaporthe oryzae by modifying the cell wall defence  

British Library Electronic Table of Contents (United Kingdom)

Emerging evidence suggests that E3 ligases play critical roles in diverse biological processes, including innate immune responses in plants. However, the mechanism of the E3 ligase involvement in plant innate immunity is unclear. We report that a rice gene, OsBBI1, encoding a RING finger protein with E3 ligase activity, mediates broad-spectrum disease resistance. The expression of OsBBI1 was induced by rice blast fungus Magnaporthe oryzae, as well as chemical inducers, benzothiadiazole and salicylic acid. Biochemical analysis revealed that OsBBI1 protein possesses E3 ubiquitin ligase activity in vitro. Genetic analysis revealed that the loss of OsBBI1 function in a Tos17-insertion line increased susceptibility, while the overexpression of OsBBI1 in transgenic plants conferred enhanced resi...

2011-01-01

287

Retuning the APS storage ring for better chromaticity correction.  

Energy Technology Data Exchange (ETDEWEB)

When the APS storage ring was retuned to provide smaller {beta}{sub y} values in the insertion straight sections, it was necessary to increase the vertical tune by at least two units. Since the design values for the horizontal and vertical tunes are 35.22 and 16.30, respectively, this put the tunes dangerously close to the sextupole 2v{sub y}-v{sub x} coupling resonance. The large injection horizontal oscillations could couple to the vertical plane and exceed the 5-mm vertical apertures that exist in some of the insertion straight sections. To avoid this resonance, the vertical tune was raised beyond the resonance to 19.30. The result was a reduction in the ability of the chromaticity sextuples to correct the chromaticity. Recent investigation has shown that the chromaticity correction capability of the sextuples can be greatly increased by a modest increase in the horizontal tune. Increasing the horizontal tune by one unit and reducing the vertical tune by three ...

1999-09-11

288

Platelet thrombosis in cardiac-valve prostheses  

International Nuclear Information System (INIS)

The contribution of platelets and clotting factors in thrombosis on cardiovascular prostheses had been quantified with several tracers. Thrombus formation in vivo could be measured semiquantitatively in animal models and patients with indium-111, Technetium-99m labeled platelets, iodine-123, iodine-131 labeled fibrinogen, and In-111 and Tc-99m labeled antibody to the fibrinogen-receptor on the platelet- membrane, or fibrin. The early studies demonstrated that certain platelet-inhibitors, e.g. sulfinpyrazone, aspirin or aspirin- persantine increased platelet survival time with mechanical valves implanted in the baboon model and patients. Thrombus localization by imaging is possible for large thrombus on thrombogenic surface of prosthesis in the acute phase. The majority of thrombus was found in the sewing ring (Dacron) in the acute phase in both the mechanical and tissue valves. The amount of retained thrombus in both mechanical and tissue valves in our one-day ...

1989-06-08

289

Performance of hybrid ball bearings in oil and jet fuel  

Energy Technology Data Exchange (ETDEWEB)

A 308-size hybrid ball bearing, with ceramic balls and steel rings, was tested using a diester oil and gas turbine fuel as lubricants at several speeds and loads. Heat generation data from this test work was then correlated with the heat generation model from a widely used computer code. The ability of this hybrid split inner ring bearing design to endure thrust reversals, which are expected in many turbine applications, was demonstrated. Finally, the bearing was successfully endurance tested in JP-10 fuel for 25 hours at 7560 N axial load and 36,000 rpm. This work has successfully demonstrated the technology necessary to use fuel-lubricated hybrid bearings in limited-life gas turbine engine applications such as missiles, drones, and other unmanned air vehicles (UAVs). In addition, it has provided guidance for use in designing such bearing systems. As a result, the benefits of removing the conventional oil lubricant system, i.e., design ...

1992-07-01

290

On the application of Allan variance method for Ring Laser Gyro performance characterization  

Energy Technology Data Exchange (ETDEWEB)

This report describes the method of Allan variance and its application to the characterization of a Ring Laser Gyro`s (RLG) performance. Allan variance, a time domain analysis technique, is an accepted IEEE standard for gyro specifications. The method was initially developed by David Allan of the National Bureau of Standards to quantify the error statistics of a Cesium beam frequency standard employed as the US Frequency Standards in 1960`s. The method can, in general, be applied to analyze the error characteristics of any precision measurement instrument. The key attribute of the method is that it allows for a finer, easier characterization and identification of error sources and their contribution to the overall noise statistics. This report presents an overview of the method, explains the relationship between Allan variance and power spectral density distribution of underlying noise sources, describes the batch and recursive implementation approaches, validates ...

1993-10-15

291

Longitudinal and transverse dynamics of a free electron laser based on a storage ring of second and third generation  

International Nuclear Information System (INIS)

This work aims at improving the understanding of the dynamics of a Free Electron Laser (FEL) based on a storage ring. A new phenomenon of saturation by the electron bunch transverse dimensions is pointed out, during the FEL operation with a magnetic optics ''low emittance''. A part of this thesis work concerns the study of the longitudinal dynamics of the FEL depending on a parameter: the detuning between the pass frequency of the electrons and the back and return frequency of the laser pulse in the optical cavity. This study shows that the FEL presents a pulsed or a steady state behavior depending on the detuning. Besides, a spectro-temporal behavior of the FEL is pointed out showing the FEL pulse substructures and holes in the spectrum. Another part of this work concerns the response of the resonant FEL system, when a perturbation is applied on the gain. Under the effect of a modulation, the FEL can present a periodic or chaotic regime. The analysis of these ...

292

Influence of some processing factors on susceptibility to caustic stress corrosion cracking of modified alloy 800  

International Nuclear Information System (INIS)

The influence of some processing factors such as cold work and heat treatment on the susceptibility to caustic stress corrosion cracking (SCC) of modified alloy 800, referred to alloy 800 M, in a boiling solution of 50%NaOH + 0.3%SiO_2+0.3%Na_2S_2O_3 was investigated by means of microstructure examination, tensile test, stress analysis, SCC test of C-rings, Auger electron spectroscopy (AES) and corrosion mode. Cold work led to lengthening of grains, decrease in ductility, increase in strength, residential stress and susceptibility to SCC. With increasing temperature of heat treatment on alloy 800 M after cold work, grains became bigger, ductility increased but strength, residential stress and susceptibility to SCC decreased. SCC cracks on C-ring specimens initiated from pitting and propagated along grain boundaries. AES analysis indicates that the surface films on alloy 800M are enriched in nickel and depleted in iron and chromium. (authors)

2005-07-01

293

Fine-ceramic anitifriction bearings  

Energy Technology Data Exchange (ETDEWEB)

Ceramic antifriction bearings were introduced in excellent characterics and application. In main shaft use bearings of the machine tool, to be heightened in efficiency and accuracy by the heightening in speed, centrifugal load to the outer ring is not negligible to shorten the bearing in life. Also ball bearings with a contact angle are easily corroded by a very strong revolution slide due to the gyromoment. The use of such light weight material as silicon nitride's can design the lengthening in life. Also the utilization of high rigidity can prevent the inner ring from expanding by centrifugal force and enable the machining to be with a high accuracy. Ceramic rolling element is excellent also in backing resistant property and effective on the oily film cut. With heat resistant property, it maintains hardness even at high temperature. Such excellent characteristics being utilized, the fine ceramic antifriction bearing is used for the ...

1989-08-01

294

Experimental investigation of the thermal contact resistance of a space-use deep groove ball bearing. Uchuyo fukamizo tamajikuukenai no sesshoku netsu teiko ni kansuru jikkenteki kento  

Energy Technology Data Exchange (ETDEWEB)

The thermal contact resistance between balls and inner and outer rings of thermally steady space-use deep groove ball bearings was studied experimentally to verify the validity of the previously proposed calculation method for the resistance. The 440C stainless steel single row bearing was used for measuring its steady state temperature distributions in a vacuum environment under axial, radial and combined load conditions. As a result, the experimental results of the resistance well agreed with calculated ones under each load condition resulting in the sufficient validity at nearly the same surface roughness. It was necessary to apply a static equivalent radial load to calculation under the combined load that a contact angle is larger than the angle of resultant force dependent on both load components. In experiments under only radial load, measurement of outer ring temperatures was necessary at some points with no contact with balls to avoid ...

1992-12-05

295

Electron beam qualities with and without free electron laser oscillations in the compact storage ring NIJI-IV  

International Nuclear Information System (INIS)

The electron-beam qualities with and without free electron laser (FEL) oscillations were investigated in the compact storage ring NIJI-IV. The peak-electron density in a bunch was suppressed by beam instabilities, so that it was limited to about 1.0 x 10"1"7 m"-"3. The maximum FEL gain estimated for 215 and 300 nm using a well-known one-dimension theory was about 2.8% and 4.6%. The cavity loss at 300 nm was evaluated to be about 2% from the threshold beam current. The bunch length and energy spread with FEL oscillations increased by 1.3 times or more due to bunch heating. The ratio of the FEL gain to a cavity loss estimated from the beam qualities with and without FEL oscillations was almost in accord with the ratio evaluated directly with the measured data of the FEL gain and the cavity loss. (author)

2003-09-01

296

Effects of DC plasma nitriding parameters on microstructure and properties of 304L stainless steel  

International Nuclear Information System (INIS)

A wear-resistant nitrided layer was formed on a 304L austenitic stainless steel substrate by DC plasma nitriding. Effects of DC plasma nitriding parameters on the structural phases, micro-hardness and dry-sliding wear behavior of the nitrided layer were investigated by optical microscopy, X-ray diffraction, scanning electron microscopy, micro-hardness testing and ring-on-block wear testing. The results show that the highest surface hardness over a case depth of about 10 #mu#m is obtained after nitriding at 460 deg. C. XRD indicated a single expanded austenite phase and a single CrN nitride phase were formed at 350 deg. C and 480 deg. C, respectively. In addition, the S-phase layers formed on the samples provided the best dry-sliding wear resistance under the ring-on-block contact configuration test.

2009-03-01

297

Detection and classification of bearing flaking using kullback discrimination information; Kullback shikibetsu johoryo (KDI) wo mochiita jikuuke no tendomen hakuri no kenchi to shikibetsu  

Energy Technology Data Exchange (ETDEWEB)

Since bearing is in wide use as basic parts for rotary machines, detection and diagnosis of its defects are important in practical use. To discriminate defect portions by early detection of roller bearing flaking, the conventional parameter method using peakedness is poor. Thus to directly obtain difference in waveform, the new method was applied to such detection which uses KDI as the scale of a difference in waveform, and a most neighborhood classification rule based on KDI. The detection and discrimination abilities of this method was studied mainly in experiment. The experiment used a bench scale rotor and a supporting bearing, and attempted detection and discrimination of no flaking, outer ring flaking and inner ring flaking. As a result, this method could detect and discriminate fine flaking which was never detected by conventional method. Since selection of standard data is essential for this method, a distance ratio was introduced as ...

1998-06-15

298

Cyclopalladated 2-phenyldihydrooxazole complexes with ethylenediamine, 2,2?-bipyridine, and bridging acetate ligands  

British Library Electronic Table of Contents (United Kingdom)

The 1H NMR, electronic absorption, and luminescence spectra, as well as voltammograms of the reduction and oxidation of the complexes [Pd(C?N)(N?N)]ClO4 and [Pd(C?N)(?-OOCCH3)]2 [where (C?N)? is deprotonated 2-phenyl-4,5-dihydro-1,3-oxazole, and N?N is ethylenediamine or 2,2?-bipyridine (bpy)] were compared. Magnetic nonequivalence of protons in the dihydrooxazole ring and upfield shift of the corresponding signals were observed as a result of anisotropic effect of the ring current in palladated phenyl substituents in the [Pd(C?N)(?-OOCCH3)]2 complex having a C 2 symmetry. One-electron reduction wave of [Pd(C?N)bpy]+ was assigned to ligand-centered electron transfer to the ?* orbital of 2,2?-bipyridine, and two oxidation waves of [Pd(C?N)(?-OOCCH3)]2 were attributed to successive one-elect...

2011-01-01

299

Crystal structures of two novel sulfonylurea herbicides in complex with Arabidopsis thaliana acetohydroxyacid synthase  

Energy Technology Data Exchange (ETDEWEB)

Acetohydroxyacid synthase (AHAS; EC 2.2.1.6) is the first enzyme in the biosynthetic pathway of the branched-chain amino acids. It catalyzes the conversion of two molecules of pyruvate into 2-acetolactate or one molecule of pyruvate and one molecule of 2-ketobutyrate into 2-aceto-2-hydroxybutyrate. AHAS requires the cofactors thiamine diphosphate (ThDP), Mg{sup 2+} and FAD for activity. The herbicides that target this enzyme are effective in protecting a broad range of crops from weed species. However, resistance in the field is now a serious problem worldwide. To address this, two new sulfonylureas, monosulfuron and monosulfuron ester, have been developed as commercial herbicides in China. These molecules differ from the traditional sulfonylureas in that the heterocyclic ring attached to the nitrogen atom of the sulfonylurea bridge is monosubstituted rather than disubstituted. The structures of these compounds in complex with the catalytic subunit of Arabidopsis ...

2009-08-17

300

Collection and analysis of particulate from the DIII-D Tokamak  

International Nuclear Information System (INIS)

Particulate (i.e. tokamak dust) has been collected from the DIII-D tokamak located at General Atomics in San Diego, CA, USA. Two methods were used to collect particulate with the goal of preserving the particle size distribution and physical characteristics of the particulate. Vacuum collection on substrates and adhesion removal with metallurgical replicating tape were chosen as non-intrusive sampling methods. Sampling was completed in four toroidal locations of the machine; the 0-90 area, the 90-180 area, the 180-270 area, and the 270-360 area. The 0 direction designates the north side of the DIII-D machine. Four tiles in each area were sampled; the first vertical tile above the floor on the centerpost, a floor tile next to the center post, a tile on the isolated ring, and the first tile up from the isolated ring on the divertor. In addition, samples were collected from underneath the floor tiles at the 275 and the 75 locations. The count ...

1998-09-01

301

Beam stabilization in SPring-8 linac for top-up injections into storage rings  

International Nuclear Information System (INIS)

The SPring-8 linac has been improved to realize stable top-up injection into the SPring-8 and the NewSUBARU storage rings. The beam energy instability of 0.02% rms in the long term was achieved by means of reducing RF variations, providing beam energy compensation, reinforcement of monitor systems and introduction of beam feedback controls: Variations in the RF power and phase have been reduced by improving the voltage regulation system for the klystron modulator, and by stabilizing the temperature drift of the atmosphere and cooling water in order to reduce the phase variation. A new synchronous oscillator synchronizes a beam trigger pulse and a 2856 MHz reference signal, reducing variation in the beam charge. A beam energy compression system (ECS) was installed to compensate for accidental energy variation and reduce the energy spread. Beam feedback controls compensate for residual long-term variations of beam trajectory and energy. (author)

2006-03-01

302

An immunochemical approach to the study of DNA damage and repair. Technical progress report, May 1, 1989--April 30, 1992  

Energy Technology Data Exchange (ETDEWEB)

The overall objective of this project has been to develop immunochemical methods to quantitate unique DNA base damages in order to facilitate studies on radiation-induced damage production and repair. Specifically, we have been using antibodies raised to damaged bases to quantitate unique lesions in model systems in order to evaluate their potential biological consequences. Our approach has been to synthesize modified nucleotides or nucleosides, conjugate them to protein carriers, and use the conjugates as immunogens in rabbits or to prepare monoclonal antibodies. We have been studying damages that are stable radiolysis products found in X-irradiated DNA and thus of potential biological consequence. Our aim is to build an in vitro and in vivo data base on the interactions between model DNA lesions and such cellular enzymes as DNA polymerases and repair endonucleases. Initial studies have focused on pyrimidine ring saturation products (thymine glycol.and ...

1992-05-01

303

An immunochemical approach to the study of DNA damage and repair  

Energy Technology Data Exchange (ETDEWEB)

The overall objective of this project has been to develop immunochemical methods to quantitate unique DNA base damages in order to facilitate studies on radiation-induced damage production and repair. Specifically, we have been using antibodies raised to damaged bases to quantitate unique lesions in model systems in order to evaluate their potential biological consequences. Our approach has been to synthesize modified nucleotides or nucleosides, conjugate them to protein carriers, and use the conjugates as immunogens in rabbits or to prepare monoclonal antibodies. We have been studying damages that are stable radiolysis products found in X-irradiated DNA and thus of potential biological consequence. Our aim is to build an in vitro and in vivo data base on the interactions between model DNA lesions and such cellular enzymes as DNA polymerases and repair endonucleases. Initial studies have focused on pyrimidine ring saturation products (thymine glycol.and ...

1992-05-01

304

Aluminum siting in mordenite and dealumination mechanism  

Science.gov (United States)

The dealumination of mordenite by acidification (HCl, HNO/sub 3/) and by SiCl/sub 4/ and steaming treatments is followed by high-resolution magic-angle-spinning solid-state /sup 29/Si and /sup 27/Al NMR spectroscopy. The combined use of these techniques leads to the determination of the silicon-aluminum ordering. It is demonstrated that aluminum atoms preferentially occupy tetrahedral positions in the four-membered rings of the mordenite structure. In addition, a mechanism of dealumination can be inferred, consisting in removing the aluminum atoms two by two from the four-membered rings. It is also possible to compute the number of SiOH groups left in the unit cell after the progressive removal of aluminum atoms: four groups per extracted Al atom are generated in the beginning of dealumination and this number gradually decreases to two, suggesting that a structural reorganization must necessarily occur for substantial dealumination. These ...

1986-10-09

305

3. 3-Bis (azidomethyl) oxetane (BAMO)-based propellants. (1). ; Synthesis and characterizatio of BAMO-based polymers. BAMO kei suishin yaku no kenkyu. (1). ; BAMO kei jugotai no gosei to tokusei hyoka  

Energy Technology Data Exchange (ETDEWEB)

Concerning high performance composite solid propellant BAMO and BAMO-based copolymers, synthetic method and properties of them were studied. Comparison graph of theoretical specific impulse for various propellants were shown, by that, reason why highest specific impulse BAMO was selected as direction of the study. As the orientation of synthesis, those were indicated that radicals at both ends should be hydroxyl so as urethane bonding was available, that liquid at normal temperature was required for easy handling, and that glass transition temperature is required to be low enough. Synthesis was conducted by ring-opening polymerization of ring ether detail procedures of which were explained. Measurements of properties was performed for thermochemical properties, thermal decomposition, combution heat, and friction sensitivity test to confirm safety. As the result, those were understood that thermal decomposition was divided into two phases, rapid ...

1990-08-31

306

Wear resistance of a laser surface alloyed Ti-6Al-4V alloy  

Energy Technology Data Exchange (ETDEWEB)

Laser surface alloying with gaseous nitrogen was utilized to improve the wear resistance of a Ti-6Al-4V alloy. Wear-resistant composite coatings reinforced by hard TiN dendrites were produced 'in-situ' on a substrate of a Ti-6Al-4V alloy. The hardness and wear resistance of the laser alloyed coating under two-body abrasive and block-on-ring full-sliding wear conditions were significantly enhanced. (orig.)

2000-08-01

307

Structure, reactivity, and biological properties of hidantoines; Estrutura, reatividade e propriedades biologicas de hidantoinas  

Energy Technology Data Exchange (ETDEWEB)

Hydantoin (imidazolidine-2,4-dione) is a 2,4-diketotetrahydroimidazole discovered by Baeyer in 1861. Thiohydantoins and derivatives were prepared, having chemical properties similar to the corresponding carbonyl compounds. Some biological activities (antimicrobial, anticonvulsant, schistosomicidal) are attributed to the chemical reactivity and consequent affinity of hydantoinic rings towards biomacromolecules. Therefore, knowledge about the chemistry of hydantoins has increased enormously. In this review, we present important aspects such as reactivity of hydantoins, acidity of hydantoins, spectroscopy and crystallographic properties, and biological activities of hydantoin and its derivatives. (author)

2008-07-01

308

String theory, black holes, and SL(2,R) current algebra  

International Nuclear Information System (INIS)

We analyse in detail the SL(2, R) black hole by extending standard techniques of Kac-Moody current algebra to the non-compact case. We construct the elements of the ground ring and exhibit W_#infinity# type structure in the fusion algebra of the discrete states. As a consequence, we can identify some of the exactly marginal deformations of the black hole. We show that these deformations alter not only the spacetime metric but also turn on non-trivial backgrounds for the tachyon and all of the massive modes of the string. (orig.).

1993-05-01

309

Steady-state neutronic investigations to the accident of water ingress in systems with pebble-bed high-temperature gas-cooled reactor fuel  

Energy Technology Data Exchange (ETDEWEB)

For light water reactors, loss of coolant is an important point in safety analysis, whereas for gas-cooled reactors the ingress of water into the core region is an incident of safety relevance. The applicability of the computer code system GAMTEREX to pebble beds of spherical high-temperature gas-cooled reactor fuel elements with simulated water ingress is verified by experiment. The measurements were performed at a Siemens-Argonaut reactor, using its ring core as a driver zone for a pebble-bed core in the center of the reactor.

1987-09-01

310

Stability against temperature variations at the ALS  

Energy Technology Data Exchange (ETDEWEB)

We have studied the effects of temperature fluctuations on the Advanced Light Source (ALS). By modeling the storage ring support structure, we find that fluctuations of {plus minus}2 to 3deg C in the tunnel will cause photon beam motion of the order of the beam size. Temperature stabilization at this level will allow the residual motion of the photon beams to be reduced by a second level of active feedback, operating on signals from photon beam position monitors. Air temperature in the experimental area and the temperature of cooling water serving the beamlines should be constant to {plus minus}1deg C. This will provide a suitable environment for experiments. (orig.).

1990-05-20

311

Review of ion accelerators  

Energy Technology Data Exchange (ETDEWEB)

The field of ion acceleration to higher energies has grown rapidly in the last years. Many new facilities as well as substantial upgrades of existing facilities have extended the mass and energy range of available beams. Perhaps more significant for the long-term development of the field has been the expansion in the applications of these beams, and the building of facilities dedicated to areas outside of nuclear physics. This review will cover many of these new developments. Emphasis will be placed on accelerators with final energies above 50 MeV/amu. Facilities such as superconducting cyclotrons and storage rings are adequately covered in other review papers, and so will not be covered here.

1990-06-01

312

Requirements and guidelines for NSLS experimental beam line vacuum systems: Revision A  

Energy Technology Data Exchange (ETDEWEB)

Requirements are provided for NSLS beam line front ends and vacuum interlocks. Guidelines are provided for UHV beam line vacuum systems, including materials, vacuum hardware (pumps, valves, and flanges), acoustic delay lines and beam line fast valves, instrumentation, fabrication and testing, and the NSLS cleaning facility. Also discussed are the design review for experimenters' equipment that would be connected to the NSLS and acceptance tests for any beam line to be connected with the ring vacuum. Also appended are a description of the acoustic delay line as well as the NSLS vacuum standards and NSLS procedures. (LEW)

1986-10-01

313

Real time neutron diffraction study on the intercalation of deuterobenzene into RbC/sub 24/  

Energy Technology Data Exchange (ETDEWEB)

The reaction of RbC/sub 24/ with C/sub 6/D/sub 6/ vapour was studied by neutron diffraction on a time scale of 5 min/spectrum. As for the reaction of KC/sub 24/, a second stage phase RbC/sub 24/(C/sub 6/D/sub 6/)sub(y) is initially formed and subsequently transformed into a first stage phase. Model calculations indicate that the benzene rings are canted against the graphite planes both in the first and in the second stage phase.

1983-11-01

314

Quantum theory of the interaction of Josephson junctions with non-classical microwaves  

Energy Technology Data Exchange (ETDEWEB)

We present a study of the interaction between Josephson junctions in circular superconducting rings and non-classical microwaves, treating both quantum mechanically. A Hamiltonian that describes both inductive and capacitive coupling between the two systems is derived within the external field approximation. Other Hamiltonians which go beyond the external field approximation, and describe explicitly the interaction of the quantum circuit that produces the non-classical microwaves with the Josephson junction circuit, are also presented. A comparison between current experiments which use classical electromagnetic fields and the proposed experiments that use non-classical microwaves, is made. (orig.) With 6 figs., 32 refs.

1997-01-01

315

Progress in construction of the LHC  

CERN Document Server

The Large Hadron Collider (LHC) project, approved by the CERN Council in December 1994, has now fully entered its construction phase, with the detailed technical definition of the major systems, and the adjudication of a number of large procurement contracts. We first recall the main features and characteristics of the LHC, report on the advances in definition of the layout and optics as well as on preparation of the injector complex, and review recent progress in the key technical systems of the main ring: magnets, cryogenics and vacuum, as well as civil construction, which has started following acceptance by authorities in the Host States.

1998-01-01

316

Polarizing a stored proton beam by spin flip?  

International Nuclear Information System (INIS)

We discuss polarizing a proton beam in a storage ring, either by selective removal or by spin flip of the stored ions. Prompted by recent, conflicting calculations, we have carried out a measurement of the spin-flip cross section in low-energy electron-proton scattering. The experiment uses the cooling electron beam at COSY as an electron target. The measured cross sections are too small for making spin flip a viable tool in polarizing a stored beam. This invalidates a recent proposal to use co-moving polarized positrons to polarize a stored antiproton beam.

2009-04-27

317

Performance Comparisons of PSO based Clustering  

CERN Document Server

In this paper we have investigated the performance of PSO Particle Swarm Optimization based clustering on few real world data sets and one artificial data set. The performances are measured by two metric namely quantization error and inter-cluster distance. The K means clustering algorithm is first implemented for all data sets, the results of which form the basis of comparison of PSO based approaches. We have explored different variants of PSO such as gbest, lbest ring, lbest vonneumann and Hybrid PSO for comparison purposes. The results reveal that PSO based clustering algorithms perform better compared to K means in all data sets.

2010-01-01

318

Operational Experience with LHC Collimation  

CERN Document Server

A first sub-set of the collimation system has been installed for the 2008 first beam commissioning of the LHC. It included 88 collimators around the ring and the two injection lines. Each collimator has two jaws for which must be controlled and monitored with high precision. The LHC collimation system was put into operation from July to October 2008. The installed system is described and first results from system operation without and with beam are presented. It is shown that the LHC collimation system achieved the specified accuracy and reproducibility of jaw positioning. Next steps in collimation commissioning are described and planned system upgrades for high beam intensities are outlined.

2009-01-01

319

Nondestructive testing of metal coating thickness and control of chemical composition using radionuclide X-ray fluorescence analysis  

International Nuclear Information System (INIS)

The principle is described of a method using low-activity emitters as the primary radiation source for analysis. The selection of the radiation source and the detection methods including the assessment of the applicability of various radiation detectors are discussed. The benefits and the constraints of the method are considered. Practical examples are presented showing the application possibilities of the method for testing the thickness of bearing layers, piston ring coats, lead layers, etc. The possibility is shown of applying the rapid test for the composition of tungsten and chromium alloyed metal materials in testing complex systems. (J.K.).

1974-12-03

320

Mechanism of biodegradation of paraquat by Lipomyces starkeyi  

Energy Technology Data Exchange (ETDEWEB)

The biodegradation of ring-/sup 14/C- and methyl-/sup 14/C-labeled paraquat by the soil yeast Lipomyces starkeyi was studied in vitro. It was found that the degradation of paraquat (acting as a sole source of culture nitrogen) resulted in the accumulation in the extracellular medium of radiolabeled acetic acid. The culture also evolved radiolabeled CO/sub 2/. The results suggest that the degradation of paraquat by L. starkeyi is associated with the integrity of the cell wall and that disruption or removal of the wall results in a complete loss of degradative capability. A mechanism for the degradation of paraquat by this organism is postulated.

1985-05-01

321

Mechanism of biodegradation of paraquat by Lipomyces starkeyi  

International Nuclear Information System (INIS)

The biodegradation of ring-"1"4C- and methyl-"1"4C-labeled paraquat by the soil yeast Lipomyces starkeyi was studied in vitro. It was found that the degradation of paraquat (acting as a sole source of culture nitrogen) resulted in the accumulation in the extracellular medium of radiolabeled acetic acid. The culture also evolved radiolabeled CO_2. The results suggest that the degradation of paraquat by L. starkeyi is associated with the integrity of the cell wall and that disruption or removal of the wall results in a complete loss of degradative capability. A mechanism for the degradation of paraquat by this organism is postulated.

322

Interactive Orbit Control in MATLAB  

Energy Technology Data Exchange (ETDEWEB)

Recent advances in steering algorithms have made it possible to accurately control electron beam position in storage rings, implement fast and slow feedback systems, and in some cases detect hardware errors. In practice, however, the program operator would like to reduce the overhead of selecting variables and constraints and to easily view the data. To simplify the process, we constructed an interactive orbit control program in MATLAB [1]. The program modules are easily adapted to new algorithms or beam lines. This paper describes the program functionality and architecture.

2001-07-06

323

Improved beam confinement in the modified betatron with strong focusing  

International Nuclear Information System (INIS)

The lifetime of the circulating electron beam in the Naval Research Laboratory modified betatron has been increased by more than 2 orders of magnitude with the addition of strong focusing windings to the device. The injected beam consistently spirals from the injector to the minor axis and is trapped. The #approx#0.5-kA trapped electron ring has been accelerated above 10 MeV from the injection energy of 0.5 to 0.6 MeV. The beam acceleration has been confirmed not only by the x-ray attenuation technique but also with the detection of photoneutrons.

324

Freezing phenomena in ice-water systems  

Energy Technology Data Exchange (ETDEWEB)

The characteristics of solidification and melting are reviewed. The properties of water and ice and the phase diagram of water are discussed with special emphasis on ice density. A concise account of the freezing process and the Stefan problem is presented. To this end, the four stages of freezing are identified, supercooling, nucleation and the formation of dendritic ice, the growth of concentric rings of solid ice at 0{sup o}C and the final cooling of the solid ice are treated in some detail. The subject of bursting of pipes is given particular emphasis. Attention is drawn to a common misconception on pipe bursting and to misleading relationships for the computation of freezing time for ice blockage. Several current applications of melting and freezing systems are outlined. (author)

2002-09-01

325

First results from the Lund NMP particle detector system  

International Nuclear Information System (INIS)

The design and first results from a Double Sided Silicon Strip Detector (DSSSD) recently installed at the Lund Nuclear Microprobe facility (NMP) are presented. The detector has 64 sector strips and 32 ring strips, which in combination give more than 2000 detector cells, each with characteristics comparable with a standard surface barrier detector (SBD). The detector has been tested both with radioactive sources and with different ion beams and energies. The most striking features are the high rate virtually pile-up free operation and also the possibility of detailed measurement of angular distributions.

2009-06-15

326

First results from the Lund NMP particle detector system  

British Library Electronic Table of Contents (United Kingdom)

The design and first results from a Double Sided Silicon Strip Detector (DSSSD) recently installed at the Lund Nuclear Microprobe facility (NMP) are presented. The detector has 64 sector strips and 32 ring strips, which in combination give more than 2000 detector cells, each with characteristics comparable with a standard surface barrier detector (SBD). The detector has been tested both with radioactive sources and with different ion beams and energies. The most striking features are the high rate virtually pile-up free operation and also the possibility of detailed measurement of angular distributions.

2009-01-01

327

Final design and manufacturing of the Cryolegs of the W7-X-superconducting coil support system  

Energy Technology Data Exchange (ETDEWEB)

One of the most complicated tasks during the assembly of the Wendelstein W7-X is the installation of the superconductive coil system. The entire magnet system is enclosed between the Outer Vessel and the plasma vessel in high vacuum at 4 K. The coils are supported by a support structure, the Central Support Structure (CSS). The CSS carries all 70 coils, and it is designed as a closed ring made of 5 modules (10 half modules). The whole structure is supported by 10 Cryolegs which rest on the machine base. This paper describes the final design and manufacture of these Cryolegs.

2008-12-15

328

Engineering electromagnetic response of composite terahertz metamaterial with broken symmetry  

Science.gov (United States)

We proposed and numerically investigated the influence of spatial symmetry on the terahertz frequency region response of composite planar metamaterials based on deformed split ring resonators. Compared with the original simple structures, the composite metamaterials with different spatial symmetries exhibited exotic electromagnetic properties. The electromagnetic response of a specific configuration with C4 symmetry was identical to the structure with simple lattice. Especially, for configurations with broken symmetry, very sharp Drude-like resonances with high quality factor were observed. The electric field and current distribution associated the resonances were analyzed for deep understanding of the underlying physical properties.

2011-09-01

329

Effect of Cl substituent in the aromatic tetracycline ring on its reactivity with solvated electrons  

Energy Technology Data Exchange (ETDEWEB)

Decomposition yields of tetracycline hydrochloride (TC.HCl) and chlorotetracycline hydrochloride (ClTC.HCl) in methanol solution saturated with Ar or N/sub 2/O were determined. Rate constants of the reaction esub(s)/sup -/ with some antibiotics were obtained. It was demonstrated by /sup 1/H NMR that the radical formed by degradation of 7-C-Cl group is recombined with the H atoms leading to ClTC.HCl being converted into tetracycline hydrochloride (TC.HCl).

1984-09-18

330

Childhood neuroborreliosis: clinicoradiological correlation  

Energy Technology Data Exchange (ETDEWEB)

We report the cranial CT and MRI findings in three children with Lyme disease (neuroborreliosis). The neuroimaging findings in children have been rarely reported. We found cranial MRI far superior to cranial CT. Ring-enhancing lesions have been described in acute disseminating encephalomyelitis and multiple sclerosis but not in neuroborreliosis. Although other infectious and inflammatory diseases cannot be excluded, Lyme disease should be included in the differential diagnosis and put forward as being the most likely diagnosis in the appropriate clinical setting. Gadopentetate dimeglumine is helpful in assessing the response to antibiotic treatment. (orig.)

1995-10-01

331

A study of aging effects in gas proportional detectors at the BAC calorimeter of the ZEUS experiment  

Energy Technology Data Exchange (ETDEWEB)

The multicell proportional chambers at the backing calorimeter of the ZEUS experiment at the storage ring HERA are supplied with a gas mixture of Ar/CO[sub 2] by an open gas system. Flow proportional counters with the build-up [sup 55]Fe sources are used as gas system monitoring detectors. The ZEUS experiment is planned to collect data for about 10 years. Therefore, the lifetime of the Ar/CO[sub 2] mixture should be known. In this paper, the results of laboratory tests and preliminary measurements of the aging effects for monitoring counters are presented. ((orig.))

1994-09-01

332

A real time neutron diffraction study on the intercalation of deuterobenzene into RbC_2_4  

International Nuclear Information System (INIS)

The reaction of RbC_2_4 with C_6D_6 vapour was studied by neutron diffraction on a time scale of 5 min/spectrum. As for the reaction of KC_2_4, a second stage phase RbC_2_4(C_6D_6)sub(y) is initially formed and subsequently transformed into a first stage phase. Model calculations indicate that the benzene rings are canted against the graphite planes both in the first and in the second stage phase. (Auth.).

1983-01-01

333

A correlation between electrochemical parameters and stress corrosion cracking of alloy 600 in high temperature caustic solution  

International Nuclear Information System (INIS)

The properties of the passive films formed on Alloy 600 at different applied potentials in 10% NaOH solution at 315 .deg. C was studied using in situ AC impedance and polarization measurements. The results were correlated with the stress corrosion cracking (SCC) behavior obtained from the C-ring tests in the same conditions. The change of the semiconductive property and the peak of relaxation time were observed at 0.2 V where the SCC rate showed a maximum. These results were also consistent with the prediction parameter for SCC obtained from fast and slow polarization scans.

2001-10-01

334

A combinatorial spanning tree model for knot Floer homology  

CERN Document Server

We iterate Manolescu's unoriented skein exact triangle in knot Floer homology with coefficients in the fraction field of the group ring (Z/2Z)[Z]. The result is a spectral sequence which converges to a stabilized version of delta-graded knot Floer homology. The (E_2,d_2) page of this spectral sequence is an algorithmically computable chain complex expressed in terms of spanning trees, and we show that there are no higher differentials. This gives the first combinatorial spanning tree model for knot Floer homology.

2011-01-01

335

Wear mechanism and wear prevention in coal-fueled diesel engines. Task 3, Traditional approaches to wear prevention  

Energy Technology Data Exchange (ETDEWEB)

Contamination of the lube-oil with hard abrasive particles leads to a three-body abrasive wear mechanism that highly accelerates piston ring/cylinder liner wear in coal-fueled diesel engines. One approach to reducing that wear is to modify the size and orientation of surface asperities on the cylinder to enhance the formation of a hydrodynamic film, and to provide avenues of escape for particles that would otherwise be trapped in the wear zone. Another approach is to introduce additives into the contaminated lube-oil that further enhance hydrodynamic film formation, form chemical films on the wearing surfaces, or form films on the contaminant particles. This work focuses on defining the effects of cylinder liner surface finish, various configurations of slots in the cylinder liner surface, and various additives in the contaminated lube-oil on the wear process. Wear tests were initiated in a bench apparatus using coal-ash contaminated lube-oil to test the various ...

1991-06-01

336

Wear mechanism and wear prevention in coal-fueled diesel engines  

Energy Technology Data Exchange (ETDEWEB)

Contamination of the lube-oil with hard abrasive particles leads to a three-body abrasive wear mechanism that highly accelerates piston ring/cylinder liner wear in coal-fueled diesel engines. One approach to reducing that wear is to modify the size and orientation of surface asperities on the cylinder to enhance the formation of a hydrodynamic film, and to provide avenues of escape for particles that would otherwise be trapped in the wear zone. Another approach is to introduce additives into the contaminated lube-oil that further enhance hydrodynamic film formation, form chemical films on the wearing surfaces, or form films on the contaminant particles. This work focuses on defining the effects of cylinder liner surface finish, various configurations of slots in the cylinder liner surface, and various additives in the contaminated lube-oil on the wear process. Wear tests were initiated in a bench apparatus using coal-ash contaminated lube-oil to test the various ...

1991-06-01

337

The Advanced Photon Source injection timing system  

Energy Technology Data Exchange (ETDEWEB)

The Advanced Photon Source consists of five accelerators. The injection timing system provides the signals required to cause a bunch emitted from the electron gun to navigate through intermediate accelerators to a specific bucket (1 out of 1296) within the storage ring. Two linacs and a positron accumulator ring operate at 60Hz while a booster synchrotron ramps and injects into the storage ring at 2Hz. The distributed, modular VME/VXI-based injection timing system is controlled by two EPICS-based input/output controllers (IOCs). Over 40 VME/VXI cards have been developed to implement the system. Card types range from 352MHz VXI timing modules to VME-based fiber optic fanouts and logic translators/drivers. All timing is distributed with fiber optics. Timing references are derived directly from machine low-level rf of 9.77MHz and 352MHz. The timing references provide triggers to programmable delay generators. Three grades of ...

1995-12-31

338

Studies of dynamic contact of ceramics and alloys for advanced heat engines: Final report  

Energy Technology Data Exchange (ETDEWEB)

In support of the efforts to apply ceramics in advanced heat engines, a study was made of the sliding performance of ceramics at the ring/cylinder interface of low heat rejection engines. The objective was to understand the basic mechanisms controlling the wear of candidate ceramics and thereby identify means for applying these ceramics effectively. Attempts to operate three different zirconias, silicon carbide, silicon nitride, and several plasma-sprayed ceramic coatings without lubrication were unsuccessful because of high friction and high wear rates. Experiments using a polyalphaolefin lubricant at temperatures to 260 C identified several combinations having wear rates in the general range likely to be acceptable for engines. Plasma-sprayed coatings of chromium oxide and hypersonic powder flame sprayed coatings of cobalt-bonded tungsten carbide performed particularly well as ring coatings. Similar performance was obtained with these ...

1988-03-01

339

Steroidal hydrocarbons of the Kishenehn Formation, northwest Montana  

Energy Technology Data Exchange (ETDEWEB)

The Oligocene Kishenehn Formation of northwest Montana and southeast British Columbia consists of fluvial and lacustrine sediments (marlstones, lignites and oil shales) deposited in an elongate, intermontane half-graben. The petroleum source rock potential and steroidal hydrocarbon distribution of selected shales of the Kishenehn Formation were examined. Several steroidal hydrocarbon series were documented, including 4-desmethylsteranes, 4-methylsteranes, sterenes, diasterenes, spirosterenes, C-ring monoaromatic steroids and B-ring monoaromatic anthrasteroids. Non-steroid hydrocarbons present include hopenes, ..beta beta..-hopanes, moretanes, perylene, botryococcane, a series of alkylcyclohexanes, and a fused-ring aromatic tentatively identified as a tetrahydrochrysene. Source rock analysis indicates that the Kishenehn Formation possesses excellent petroleum source potential. Conventional thermal maturity parameters, as ...

1987-01-01

340

Prostaglandin (PG) E3 synthesis elicted by adrenergic stimuli in guinea-pig trachea (GPT) is mediated primarily by B2 adrenergic receptors  

Science.gov (United States)

The purpose of this study was to examine arachidonic acid (AA) metabolism and to characterize the type of adrenergic receptor (AR) involved in the production of the major metabolite of this fatty acid. ({sup 14}C)AA was incubated with GPT-rings and the radiolabelled products were extracted and separated by TLC method. The medium was also assayed for radiolabelled immunoreactive PG's (iPG's) and leukotrienes (LT) B4 and C4 by RIA or Enzyme immunoassay (EIA) after exposure to various AR agonists. ({sup 14}C)AA was incorporated into GPT-rings and metabolized mainly into iPGE2 and smaller amounts into PGF2{alpha}. Trace amounts of PGD2 and 6-keto-PGF1{alpha} but not LTB4 or LTC4 were detected by RIA and/or EIA. Incubation of GPT rings for 15 minutes with isoproterenol and salbutamol resulted in a significant increase of PGE2 synthesis (optimum conc: 10{sup {minus}7}, 10{sup {minus}7}M respectively). In ...

1990-02-26

341

Prostaglandin (PG) E3 synthesis elicted by adrenergic stimuli in guinea-pig trachea (GPT) is mediated primarily by B2 adrenergic receptors  

International Nuclear Information System (INIS)

The purpose of this study was to examine arachidonic acid (AA) metabolism and to characterize the type of adrenergic receptor (AR) involved in the production of the major metabolite of this fatty acid. ["1"4C]AA was incubated with GPT-rings and the radiolabelled products were extracted and separated by TLC method. The medium was also assayed for radiolabelled immunoreactive PG's (iPG's) and leukotrienes (LT) B4 and C4 by RIA or Enzyme immunoassay (EIA) after exposure to various AR agonists. ["1"4C]AA was incorporated into GPT-rings and metabolized mainly into iPGE2 and smaller amounts into PGF2#alpha#. Trace amounts of PGD2 and 6-keto-PGF1#alpha# but not LTB4 or LTC4 were detected by RIA and/or EIA. Incubation of GPT rings for 15 minutes with isoproterenol and salbutamol resulted in a significant increase of PGE2 synthesis (optimum conc: 10"-"7, 10"-"7M respectively). In contrast, dobutamine, norepinephrine, phenylnephrine ...

1991-04-21

342

Basic study of entire whole-body PET scanners based on the OpenPET geometry  

International Nuclear Information System (INIS)

A conventional PET scanner has a 15-25 cm axial field-of-view (FOV) and images a whole body using about six bed positions. An OpenPET geometry can extend the axial FOV with a limited number of detectors. The entire whole-body PET scanner must be able to process a large amount of data effectively. In this work, we study feasibility of the fully 3D entire whole-body PET scanner using the GATE simulation. The OpenPET has 12 block detector rings with the ring diameter of 840 mm and each block detector ring consists of 48 depth-of-interaction (DOI) detectors. The OpenPET has the axial length of 895.95 mm with five parts of 58.95 mm open gaps. The OpenPET has higher single data loss than a conventional PET scanner at grouping circuits. NECR of the OpenPET decreases by single data loss. But single data loss is mitigated by separating the axially arranged detector into two parts. Also, multiple coincidences are found to be ...

2010-09-01

343

Widely Linear Kalman Filtering  

CERN Document Server

For a zero mean, proper, complex random vector x, the Hermitian covariance ExxH is a complete second-order characterization. However, if the vector x is improper, it is correlated with its complex conjugate, meaning ExxT = 0. This improper or complementary covariance must be accounted for in a complete second-order characterization. The improper covariance has been exploited for widely linear (WL) Wiener filters and WL minimum mean squared error (MMSE) estimators, and the improvement in performance of the WLMMSE estimator over the LMMSE estimator has been quantified. In this paper we consider the design of the widely linear Kalman filter (WLKF). We analyze the WLKF, extended WLKF, and unscented WLKF. The key idea of this paper is to modify the error covariance matrices and the construction of effective sigma points in the WLKF in a systematic way that exploits the Hermitian and complementary covariance of improper states and noises.

2011-01-01

344

Validity of the CT to attenuation coefficient map conversion methods  

International Nuclear Information System (INIS)

The most important commercialized methods of attenuation correction in SPECT are based on attenuation coefficient map from a transmission imaging method. The transmission imaging system can be the linear source of radioelement or a X-ray CT system. The image of transmission imaging system is not useful unless to replacement of the attenuation coefficient or CT number with the attenuation coefficient in SPECT energy. In this paper we essay to evaluate the validity and estimate the error of the most used method of this transformation. The final result shows that the methods which use a linear or multi-linear curve accept a error in their estimation. The value of mA is not important but the patient thickness is very important and it can introduce a error more than 10 percent in the final result.

2004-04-27

345

VLEPP based photon linear collider 100x100 GeV with ultimate luminosity  

Energy Technology Data Exchange (ETDEWEB)

The possible parameters of a photon linear collider at its ultimate luminosity, based on the VLEPP physics and technology V.E. Balakin et al., Proc. 6th Nat. Conf. on Accelerators, Dubna, 1978; V.E. Balakin, Proc. 4th Int. Workshop on Next Generation Linear Colliders, Garmisch, 1992, are presented. At a photon energy of 100x100 GeV the maximum achievable luminosity is about 1x10{sup 36} cm{sup -2} s{sup -1}. Beam parameters, luminosity characteristics, and ways to reduce the background are considered as well. ((orig.)).

1995-02-01

346

Studies with a generalized neuron based Pss on a multi-machine power system  

International Nuclear Information System (INIS)

An artificial neural network can be used as an intelligent controller to control non-linear, dynamic system through learning. It can easily accommodate non-linearities and time dependencies. Most common multi-layer feed-forward neural networks have drawbacks of large number of neurons and hidden layers required to deal with complex problems and require large training time. To overcome these drawbacks, a generalized neuron based non-linear controller has been developed and illustrated as a power system stabilizer. Studies on a five-machine power system show that the proposed controller can significantly improve the dynamic performance and provide good damping of the power system over a wide operating range.

2004-07-01

347

Spin-dependent potentials in the linearized collective Schroedinger equation for nuclear quadrupole vibrations  

Energy Technology Data Exchange (ETDEWEB)

The linearized collective Schroedinger equation for nuclear quadrupole surface vibrations incorporates a new spin degree of freeedom with a spin value of 3/2. We use this equation to describe the low energy spectrum of certain even-odd Ir nuclei which have a spin 3/2 in their ground state. For that purpose we explicitly introduce collective spin-dependent potentials which simulate the interaction of the valence nucleon with the core. The linearized Schroedinger equation is transformed into an effective Schroedinger equation with collective spin-dependent potentials. Already collective spin-orbit couplings of SO(3) and SO(5) type are sufficient to reproduce the lowest excited states of even-odd Ir nuclei. (orig.).

1990-06-01

348

Spin-dependent potentials in the linearized collective Schroedinger equation for nuclear quadrupole vibrations  

International Nuclear Information System (INIS)

The linearized collective Schroedinger equation for nuclear quadrupole surface vibrations incorporates a new spin degree of freeedom with a spin value of 3/2. We use this equation to describe the low energy spectrum of certain even-odd Ir nuclei which have a spin 3/2 in their ground state. For that purpose we explicitly introduce collective spin-dependent potentials which simulate the interaction of the valence nucleon with the core. The linearized Schroedinger equation is transformed into an effective Schroedinger equation with collective spin-dependent potentials. Already collective spin-orbit couplings of SO(3) and SO(5) type are sufficient to reproduce the lowest excited states of even-odd Ir nuclei. (orig.).

349

Single charged top-pion production at next generation #gamma##gamma# colliders  

International Nuclear Information System (INIS)

The future e"+e"- linear colliders can also operate in the e#gamma# or #gamma##gamma# modes. In the context of the top-color assisted technicolor (TC2) model, we study the single charged top-pion production process #gamma##gamma# #-># tb-bar#PI#_t"-. The results show that the production rates can reach the level of tens fb with reasonable parameter values. So one can expect that enough signals could be produced in future high-energy linear collider experiments. Furthermore, the flavor-changing (FC) decay mode #PI#_t"- #-># bc-bar is the best channel to detect the charged top pion due to the clean standard model background. With a large number of events and the clean background, the charged top pion should be observable at future linear colliders operating in #gamma##gamma# mode at the TeV energy scale

2008-09-01

350

REALISTIC NON-LINEAR MODEL AND FIELD QUALITY ANALYSIS IN RHIC INTERACTION REGIONS.  

Energy Technology Data Exchange (ETDEWEB)

The existence of multipole components in the dipole and quadrupole magnets is one of the factors limiting the beam stability in the RHIC operations. So, a realistic non-linear model is crucial for understanding the beam behavior and to achieve the ultimate performance in RHIC. A procedure is developed to build a non-linear model using the available multipole component data obtained from measurements of RHIC magnets. We first discuss the measurements performed at different stages of manufacturing of the magnets in relation to their current state in RHIC. We then describe the procedure to implement these measurement data into tracking models, including the implementation of the multipole feed down effect due to the beam orbit offset from the magnet center. Finally, the field quality analysis in the RHIC interaction regions (IR) is presented.

2007-06-25

351

Proximity effect correction of a laser lithography process for photomask fabrication  

Energy Technology Data Exchange (ETDEWEB)

We report on the improvement of Critical Dimension (CD) linearity on a photomask by applying the concept of process proximity correction to a laser lithographic process used for fabrication of photomasks. Rule-based Laser Process proximity Correction (LPC) was performed using an automated optical proximity correction tool and we obtained dramatic improvement of CD linearity on a photomask. A study on model-based LPC was executed using a two-Gaussian kernel function and we extracted model parameters for the laser lithographic process by fitting the model-predicted CD linearity data with measured ones. Model-predicted bias values of isolated space (I/S), Arrayed Contact (A/C) and Isolated Contact (I/C) were in good agreement with those obtained by the nonlinear curve-fitting method used for the rule-based LPC.

2004-07-01

352

Proximity effect correction of a laser lithography process for photomask fabrication  

International Nuclear Information System (INIS)

We report on the improvement of Critical Dimension (CD) linearity on a photomask by applying the concept of process proximity correction to a laser lithographic process used for fabrication of photomasks. Rule-based Laser Process proximity Correction (LPC) was performed using an automated optical proximity correction tool and we obtained dramatic improvement of CD linearity on a photomask. A study on model-based LPC was executed using a two-Gaussian kernel function and we extracted model parameters for the laser lithographic process by fitting the model-predicted CD linearity data with measured ones. Model-predicted bias values of isolated space (I/S), Arrayed Contact (A/C) and Isolated Contact (I/C) were in good agreement with those obtained by the nonlinear curve-fitting method used for the rule-based LPC.

2004-11-04

353

On tachyons, gauged linear sigma models, and flip transitions  

Energy Technology Data Exchange (ETDEWEB)

We study systems of multiple localized closed string tachyons and the phenomena associated with their condensation, in C{sup 3}/Z{sub N} non-supersymmetric noncompact orbifold singularities using gauged linear sigma model constructions, following hep-th/0406039. Our study reveals close connections between the combinatorics of non-supersymmetric flip transitions (between topologically distinct resolutions of the original singularity), the physics of tachyons of different degrees of relevance and the singularity structure of the corresponding residual endpoint geometries. This in turn can be used to study the stability of the phases of gauged linear sigma models and gain qualitative insight into the closed string tachyon potential. (author)

2005-02-01

354

Linearized augmented-plane-wave method for quasi-unidimensional systems: Carbyne and nanotube (Sc@C{sub 20})  

Energy Technology Data Exchange (ETDEWEB)

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

1995-10-01

355

Influence of the curved geometrical shape on the thin shell buckling phenomenon behaviour  

British Library Electronic Table of Contents (United Kingdom)

The present paper deals with instabilities of long homogeneous and isotropic thin shells, characterized by geometrical non-linearities and imperfections, with reference to a bent helicoidally geometrical shape of particular interest for the helicoidal steam generators tube bundle. Apparently no data exist in the literature to describe the non-linear buckling behaviour of curved thin shells under external pressure, thus, the theoretical analyses based on the classical linear elastic theory, as expected, might be inadequate to evaluate the collapse load especially if the curvature is rather large. To the purpose of determining the buckling pressure load the effects of a pre-existing level of geometrical and technological imperfection, unavoidably caused by various manufacturing processes wer...

2009-01-01

356

Dielectric-wall linear accelerator with a high voltage fast rise time switch that includes a pair of electrodes between which are laminated alternating layers of isolated conductors and insulators  

Energy Technology Data Exchange (ETDEWEB)

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

1998-01-01

357

Dielectric-wall linear accelerator with a high voltage fast rise time switch that includes a pair of electrodes between which are laminated alternating layers of isolated conductors and insulators  

Energy Technology Data Exchange (ETDEWEB)

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

1998-10-13

358

Development of linear flow rate control system for eccentric butter-fly valve  

Energy Technology Data Exchange (ETDEWEB)

Butter-fly valves are advantageous over gate, globe, plug, and ball valves in a variety of installations, particularly in the large sizes. The purpose of this project development of linear flow rate control system for eccentric butter-fly valve (intelligent butter-fly valve system). The intelligent butter-fly valve system consist of a valve body, micro controller. The micro controller consist of torque control system, pressure censor, worm and worm gear and communication line etc. The characteristics of intelligent butter-fly valve system as follows: Linear flow rate control function. Digital remote control function. guard function. Self-checking function. (author)

1999-12-01

359

Buckling and ultimate capability of plates and stiffened panels in axial compression  

British Library Electronic Table of Contents (United Kingdom)

This paper presents extensive non-linear finite element (FE) analysis and formulation development work carried out on the ultimate compressive strength of plates and stiffened panels of ship structures. A review of contemporary designs for large ships was carried out. The existing formulae for plate ultimate compressive strength were reviewed and compared with non-linear FE analysis results. A semi-analytical formula for ultimate compressive strength assessments of stiffened panels was proposed and is described. The developed formula was verified against results using ABAQUS non-linear FE software for a series of 61 stiffened panels and a good agreement between the proposed formula and FE results were achieved. The method was verified against a large number of published FE results and was ...

2009-01-01

360

AWGN Channel Analysis of Terminated LDPC Convolutional Codes  

CERN Document Server

It has previously been shown that ensembles of terminated protograph-based low-density parity-check (LDPC) convolutional codes have a typical minimum distance that grows linearly with block length and that they are capable of achieving capacity approaching iterative decoding thresholds on the binary erasure channel (BEC). In this paper, we review a recent result that the dramatic threshold improvement obtained by terminating LDPC convolutional codes extends to the additive white Gaussian noise (AWGN) channel. Also, using a (3,6)-regular protograph-based LDPC convolutional code ensemble as an example, we perform an asymptotic trapping set analysis of terminated LDPC convolutional code ensembles. In addition to capacity approaching iterative decoding thresholds and linearly growing minimum distance, we find that the smallest non-empty trapping set of a terminated ensemble grows linearly with block length.

2011-01-01

361

U of C site vies for new particle accelerator  

CERN Multimedia

"American dominance in the study and development of high-energy particle physics may be seriously compromised, according to a report issued by the National Academy of Sciences, unless efforts are made to ensure that the next high-energy particle accelerator - the International Linear Collider (ILC) - will be constructed in the U.S.

2006-01-01

362

Top quark physics: Summary  

International Nuclear Information System (INIS)

This talk summarizes recent progress in top quark physics studies for high energy linear electron-positron colliders as presented at the LCWS2000 Workshop at Fermilab. New results were presented for top pair production at threshold and in the continuum, as well as for top production at #gamma##gamma# colliders.

2001-07-09

363

Three-dimensional mise-a-la-masse modeling using horizontal well; Suihei kosei wo mochiita ryuden den`iho no sanjigen modeling  

Energy Technology Data Exchange (ETDEWEB)

The 3-D model program was developed to apply a mise-a-la-masse method to linear current sources with optional shapes. Mise-a-la-masse method is a bipolar mapping survey method using current sources installed in wells, and recently has been widely used for direct exploration of geothermal reservoirs. This method is also used for monitoring underground fluid as electrode arrangement of fluid flow tomography for surveying underground fluid (geothermal fluid, underground water, petroleum). In the geothermal reservoir exploration, the casing pipes of wells are used as linear current sources, and measured data are processed as those based on vertical current source. In the largely inclined well, the inclination of current sources should be considered. The 3-D modeling program was developed by difference calculus using the theoretical potential equation and apparent resistivity based on linear current sources with optional 3-D ...

1996-10-01

364

The protective antigens of equine herpesvirus type 1.  

UK PubMed Central (United Kingdom)

Equine herpesvirus type 1 was cultivated in swine testis cell cultures and partially purified by differential centrifugation and centrifugation in a linear sucrose density gradient. The viral envelope...Full Text Available

1978-04-01

365

The Non-linear Relationship between Gait Speed and Falls: The MOBILIZE Boston Study  

UK PubMed Central (United Kingdom)

OBJECTIVESAlthough several studies suggest that slow gait speed is a predictor of falls, it may also be a protective mechanism to prevent falls. Further, fast walking...Full Text Available

2011-06-01

366

Temporal measures and controls in ultrafast laser domain; Mesures et controles temporels dans le domaine des lasers ultrabrefs  

Energy Technology Data Exchange (ETDEWEB)

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

2004-12-15

367

Strand displacement synthesis capability of Moloney murine leukemia virus reverse transcriptase.  

UK PubMed Central (United Kingdom)

The accepted model of retroviral reverse transcription includes a circular DNA intermediate which requires strand displacement synthesis for linearization and creation of an integration-competent, long...Full Text Available

1994-08-01

368

Smith-Purcell oscillator in an exponential gain regime  

International Nuclear Information System (INIS)

A Smith-Purcell oscillator with a thick electron beam is analyzed in its exponential gain regime. A threshold current less than 1[A] is found for a 1 mm wavelength; this threshold is much lower than that of a similar oscillator operating in a linear gain regime.

1988-11-02

369

Sintering behavior and mechanical properties of zirconia compacts fabricated by uniaxial press forming  

UK PubMed Central (United Kingdom)

PURPOSEThe purpose of this study was to compare the linear sintering behavior of presintered zirconia blocks of various densities. The mechanical properties of the resulting sintered...Full Text Available

2010-09-01

370

Real-time system for processing regime diagnostic on accelerator  

International Nuclear Information System (INIS)

The automatic real-time system operating at the LU-10 linac and providing measurements of the parameters such as the beam current (average and pulse values), the electron energy, the linear density distribution of beam current, and also the conveyor speed is described in the paper.

371

Nonnegative Factorization of Diffusion Tensor Images and Its Applications  

UK PubMed Central (United Kingdom)

This paper proposes a novel method for computing linear basis images from tensor-valued image data. As a generalization of the nonnegative matrix factorization, the proposed method aims to approximate...Full Text Available

2011-01-01

372

Noncommutative differential geometry and connections on simplicial manifolds  

Energy Technology Data Exchange (ETDEWEB)

For a simplicial manifold we construct the differential geometry structure and use it to investigate linear connections, metric and gravity. We discuss and compare three main approaches and calculate the resulting gravity action functionals. (author)

1997-05-01

373

Neutron data requirements for calculating transactinide isotope build-up in reactors  

International Nuclear Information System (INIS)

Based on a generalized theory of perturbations and on non-linear programming an approach to the quantitative determination of necessary accuracies for nuclear data is described. It is used to calculate transactinide isotope build-up in reactors.

1979-08-01

374

Linear and Nonlinear Effects of Habitat Structure on Composition and Abundance in the Macroinvertebrate Community of a ...  

Science.gov (United States)

... describe the relationship (Peake and Quinn, 1993). The power model was considered best if the R2 from this ... when stone abundance was low (Fig. 2). The power model best described the nonlinear relations...

375

Leibnizian, Robinsonian, and Boolean valued monads  

British Library Electronic Table of Contents (United Kingdom)

This is an overview of the present-day versions of monadology with some applications to vector lattices and linear inequalities. Two approaches to combining nonstandard set-theoretic models are sketched and illustrated by order convergence, principal projection, and polyhedrality.

2011-01-01

376

Impact of kerogen heterogeneity on sorption of organic pollutants. 2. Sorption equilibria  

Energy Technology Data Exchange (ETDEWEB)

Phenanthrene and naphthalene sorption isotherms were measured for three different series of kerogen materials using completely mixed batch reactors. Sorption isotherms were nonlinear for each sorbate-sorbent system, and the Freundlich isotherm equation fit the sorption data well. The Freundlich isotherm linearity parameter n ranged from 0.192 to 0.729 for phenanthrene and from 0.389 to 0.731 for naphthalene. The n values correlated linearly with rigidity and aromaticity of the kerogen matrix, but the single-point, organic carbon-normalized distribution coefficients varied dramatically among the tested sorbents. A dual-mode sorption equation consisting of a linear partitioning domain and a Langmuir adsorption domain adequately quantified the overall sorption equilibrium for each sorbent-sorbate system. Both models fit the data well, with r{sup 2} values of 0.965 to 0.996 for the Freundlich model and 0.963 to 0.997 for the ...

2009-08-15

377

Hydrogen isotope effects in hydride transfer reactions of formaldehyde and glyoxal  

International Nuclear Information System (INIS)

In the presence of hydroxyl anion, both formaldehyde and glyoxal are known to undergo rearrangements involving intermolecular and intramolecular hydride transfer (the Cannizzaro and Benzilic acid rearrangements respectively). The authors report ab initio SCF-MO calculations of the transition state geometries, the activation barriers, and the hydrogen isotope effects for these two reactions. The structure of the transition state for the rection involving formaldehyde is usually basis set dependent, becoming more linear and symmetrical as the basis set size increases. In contrast, the analogous transition state for the glyoxal reaction involves a highly non-linear hydride transfer. They find the isotope effects to be quite low for the Cannizzaro reaction, and significantly larger for the non-linear benzilic acid rection, in apparent contradiction to Westheimer's suggestion the isotope effects reach a maximum for ...

1987-04-01

378

Evaluation of patients' assessment of day hospital care.  

UK PubMed Central (United Kingdom)

The method of linear analogue self-assessment (LASA) was used to quantify the views concerning day care which were held by patients attending a geriatric day hospital. The results suggest that day hospitals...Full Text Available

1977-09-01

379

Emotions run high in race for collider  

CERN Multimedia

The head of KEK expressed his dismay that SLAC has entered into a collaboration with 3 other US labs and proposes to build the next linear collider at Fermilab, Ilinois. KEK wants the next accelerator to be built somewhere in the Asian Pacific region (1 page).

2001-01-01

380

Decoding of Matrix-Product Codes  

CERN Document Server

We propose a decoding algorithm for the $(u\\mid u+v)$-construction that decodes up to half of the minimum distance of the linear code. We extend this algorithm for a class of matrix-product codes in two different ways. In some cases, one can decode beyond the error correction capability of the code.

2011-01-01

381

Conventional Linear versus Purse-string Skin Closure after Loop Ileostomy Reversal: Comparison of Wound Infection Rates and Operative Outcomes  

UK PubMed Central (United Kingdom)

PurposeWound infection after an ileostomy reversal is a common problem. To reduce wound-related complications, purse-string skin closure was introduced as an alternative to conventional...Full Text Available

2011-04-01

382

Characterization of genes in the cellulose-synthesizing operon (acs operon) of Acetobacter xylinum: implications for cellulose crystallization.  

UK PubMed Central (United Kingdom)

The synthesis of an extracellular ribbon of cellulose in the bacterium Acetobacter xylinum takes place from linearly arranged, membrane-localized, cellulose-synthesizing and extrusion complexes that...Full Text Available

1994-09-01

383

Can Deterministic Mechanical Size Effects Contribute to Fracture and Microdamage Accumulation in Trabecular Bone?  

UK PubMed Central (United Kingdom)

Failure of bone under monotonic and cyclic loading is related to the bone mineral density, the quality of the bone matrix and the evolution of microcracks. The theory of linear elastic fracture...Full Text Available

2010-07-21

384

A two-stage sequential linear programming approach to IMRT dose optimization  

UK PubMed Central (United Kingdom)

The conventional IMRT planning process involves two stages in which the first stage consists of fast but approximate idealized pencil beam dose calculations and dose optimization and the second...Full Text Available

2010-02-07

385

A second origin of DNA plus-strand synthesis is required for optimal human immunodeficiency virus replication.  

UK PubMed Central (United Kingdom)

We recently reported that human immunodeficiency virus type 1 (HIV-1) unintegrated linear DNA displays a discontinuity in its plus strand, precisely defined by a second copy of the polypurine tract...Full Text Available

1992-05-01

386

A relativistic semigroup, the Lorentz group and tachyons  

International Nuclear Information System (INIS)

The construction of the linear isomorphous and relativistic semigroup, of the Lorentz group and of tachyons was done using a dual pair of space-times, where the sought realization of the parametric semigroup is the semigroup of relativist endomorphisms. The obtained relativistic semigroup of dual space-time transformations possesses certain theoretical-probability properties.

387

A rapid and efficient method for region- and strand-specific mutagenesis of cloned DNA.  

UK PubMed Central (United Kingdom)

The single-stranded viral DNA of an M13 phage recombinant containing the early promoter region of SV40 was hybridized with linear, double-stranded replicative form DNA of a related M13 phage containing...Full Text Available

1982-01-01

388

Various clinical situations and their influence on linear occlusion in treating combination syndrome: a discussion of treatment options.  

Science.gov (United States)

Eliminating anterior tooth contact is paramount when treating combination syndrome. It is possible to do so through the use of linear occlusion with a non-interceptive arrangement and the bilateral fulcrum of protrusive stability. The presence of mandibular anterior teeth often complicates this procedure. When establishing the horizontal plane of occlusion, clinical circumstances often necessitate modifications; nevertheless, certain principles must be incorporated into the design of the prostheses. Clinical circumstances may dictate altering the approach but these principles must be maintained to eliminate anterior hyperfunction. PMID:15055634

389

Triple-vector-boson processes in #gamma##gamma# colliders  

International Nuclear Information System (INIS)

We study the production of three gauge bosons (W"+W"-Z"0 and W"+W"-#gamma#) at the next generation of linear e"+e"- colliders operating in the #gamma##gamma# mode. We analyze the total cross sections as well as several kinematical distributions of the final state particles. We find out that a linear e"+e"- machine operating in the #gamma##gamma# mode will produce 5--10 times more three-gauge-boson states compared to the standard e"+e"- mode at high energies.

390

Reliability analysis of discrete event dynamic systems with Petri nets  

International Nuclear Information System (INIS)

This paper deals with dynamic reliability of embedded systems. It presents a method for deriving feared scenarios (which might lead the system to a critical situation) in Petri nets. A classical way to obtain scenarios in Petri nets is to generate the reachability graph. However, for complex systems, it leads to the state space explosion. To avoid this problem, in our approach, Petri net reachability is translated into provability of linear logic sequents. Linear logic bases are introduced and used to formally define scenarios and minimality of scenarios. These definitions allow the method to produce only pertinent scenarios. The steps of the method are described and illustrated through a landing-gear system example.

2009-11-01

391

Production of four-weak-bosons and heavy Higgs signals in TeV photon-photon collisions  

Energy Technology Data Exchange (ETDEWEB)

We have studied the signals for a heavy Higgs boson in the processes {gamma}{gamma}{yields}WWWW, and {gamma}{gamma}{yields}WWZZ at a photon linear collider. The results are based on the first complete tree-level calculation for these reactions. We show that, with a forward ``spectator`` W tag, and a central ``spectator`` W veto to suppress backgrounds from transverse W, Z production, the invariant mass spectrum of central WW, ZZ pairs is sensitive to Higgs bosons with a mass up to 1 TeV in a 2-TeV linear collider. ((orig.)).

1995-02-01

392

Practical purification scheme for decohered coherent-state superpositions via partial homodyne detection  

International Nuclear Information System (INIS)

We present a simple protocol to purify a coherent-state superposition that has undergone a linear lossy channel. The scheme constitutes only a single beam splitter and a homodyne detector, and thus is experimentally feasible. In practice, a superposition of coherent states is transformed into a classical mixture of coherent states by linear loss, which is usually the dominant decoherence mechanism in optical systems. We also address the possibility of producing a larger amplitude superposition state from decohered states, and show that in most cases the decoherence of the states are amplified along with the amplitude.

2006-04-01

393

On the optimal taxation of common-pool resources  

British Library Electronic Table of Contents (United Kingdom)

Recent research developments in common-pool resource models emphasize the importance of links with ecological systems and the presence of non-linearities, thresholds and multiple steady states. In a recent paper Kossioris et al. (2008) develop a methodology for deriving feedback Nash equilibria for non-linear differential games and apply this methodology to a common-pool resource model of a lake where pollution corresponds to benefits and at the same time affects the ecosystem services. This paper studies the structure of optimal state-dependent taxes that steer the combined economic-ecological system towards the trajectory of optimal management, and provides an algorithm for calculating such taxes.

2011-01-01

394

Non-linear mathematical model of dynamics of horizontal steam generator for nuclear power unit with pressurized water reactor  

International Nuclear Information System (INIS)

A non-linear mathematical model of dynamics of horizontal steam generator for nuclear power unit with WWER type reactor is presented. To realize this model the GEMMA-120 simulation language for computer Odra-1204 has been used. Necessity of taking into account disposited thermal storage capacities along tubulation of a primary cycle is demonstrated. A number of lumped elements of reactor division against a required static accuracy of calculations has been determined. (author).

1977-01-01

395

New concepts in risk assessment for patients with radiological treatment  

International Nuclear Information System (INIS)

In radiation risk assessment it must be differentiated between somatic and genetic effect on the one hand as well as between stochastic and non-stochastic effect on the other. According to definitions of the ICRP report 26 the limit for the dose equivalent of all tissues prevents non-stochastic radiation effects. With stochastic radiation effects probably exist no threshold doses; therefore the ALARA principle must be applied concerning radiation protection. The individual risk by stochastic radiation effects in its linear, linear-quadratic and quadratic extrapolations, respectively, is discussed in detail. The effective stochastic dose equivalent (H/sub eff/) as well as collective dose and collective damage are outlined.

1986-01-01

396

Neural solution to the target intercept problems in a gun fire control system  

British Library Electronic Table of Contents (United Kingdom)

Time delay neural networks trained with the backpropagation algorithm are derived for the gun fire control system to correct the miss distance between a target and the projectiles from the gun. Its performance is compared to optimum linear filter based on minimum mean square error [R.E. Kalman, A new approach to linear filtering and prediction problems, J. Basic Eng. 82D (1960) 35-44.]. The structure of the proposed neural controller is described and performance results are shown.

2007-01-01

397

Multigrid Particle-in-cell Simulations of Plasma Microturbulence  

Energy Technology Data Exchange (ETDEWEB)

A new scheme to accurately retain kinetic electron effects in particle-in-cell (PIC) simulations for the case of electrostatic drift waves is presented. The splitting scheme, which is based on exact separation between adiabatic and on adiabatic electron responses, is shown to yield more accurate linear growth rates than the standard df scheme. The linear and nonlinear elliptic problems that arise in the splitting scheme are solved using a multi-grid solver. The multi-grid particle-in-cell approach offers an attractive path, both from the physics and numerical points of view, to simulate kinetic electron dynamics in global toroidal plasmas.

2003-06-17

398

Microstructure Characterization of Magnetic-Pulse-Welded AA 6061-T6 by Electron Backscattered Diffraction  

Energy Technology Data Exchange (ETDEWEB)

The grain boundary crystallographic misorientations of magnetic-pulse-welded (MPW) aluminum alloy (AA) 6061-T6 in linear and tubular configurations were examined using the electron backscattered diffraction (EBSD) technique. A refined structure of heavily deformed grains with higher grain boundary angles was observed in linear welds. Significant spalling was observed away from the joints, in the interior of tubular welds. The results show the complex interaction of shock waves with the materials during this impact welding process.

2008-08-01

399

Microbuckling compression failure of a radiation-induced wood/polymer composite  

Energy Technology Data Exchange (ETDEWEB)

A wood/polymer composite was produced by impregnating Ramin wood with methyl methacrylate monomer and subsequently polymerizing it by gamma irradiation. To assess the improvement in compression strength of the wood caused by the polymer impregnation, a microbuckling compression failure mechanism was used to model the compression failure of the composite. Such a mechanism was found to predict a linear relationship between the compression strength and the percentage polymer impregnation (by weight). Uniaxial compression test results at 45({plus minus}5)% and 90({plus minus}5)% relative humidity levels, after being statistically analysed, showed that such a linear relationship was valid for up to 100% polymer impregnation. (author).

1990-01-01

400

Microbuckling compression failure of a radiation-induced wood/polymer composite  

International Nuclear Information System (INIS)

A wood/polymer composite was produced by impregnating Ramin wood with methyl methacrylate monomer and subsequently polymerizing it by gamma irradiation. To assess the improvement in compression strength of the wood caused by the polymer impregnation, a microbuckling compression failure mechanism was used to model the compression failure of the composite. Such a mechanism was found to predict a linear relationship between the compression strength and the percentage polymer impregnation (by weight). Uniaxial compression test results at 45(#+-#5)% and 90(#+-#5)% relative humidity levels, after being statistically analysed, showed that such a linear relationship was valid for up to 100% polymer impregnation. (author).

1990-01-01

401

Local-density-functional approximation to the energy band structure of TmS using the self-consistent relativistic linearized-augmented-plane-wave method  

International Nuclear Information System (INIS)

The self-consistent relativistic linearized-augmented-plane-wave method is applied to local-density calculation of electronic structure of TmS. It is found that thulium monosulphide is a compound with a trivalent state of thulium. The influence of spin-orbital interaction is shown for different symmetry states of electrons. Calculated densities of states are used for the estimation of the electron-phonon coupling constant. And in conclusion it is shown that TmS is a high temperature Kondo-like system. (author).

402

Heating of magneto-rheological fluid dampers: a theoretical study  

Science.gov (United States)

This paper focuses on a theoretical model that predicts the temperature increase of Magneto-rheological (MR) fluid dampers experiencing a sinusoidal input motion. A theoretical model is developed to estimate the temperature rise based on the non-linear behavior of the MR fluid damper. This model is solved numerically, and the numerical solution is compared with a known linear solution and experimental result in order to validate the accuracy of the model. Also, a non-dimensional form of the governing equations are developed to examine the key parameters. The non-dimensional terms show the effect of external and internal parameters on the trends of heat dissipation as well as heat generation within the MR fluid damper.

1999-05-01

403

Gamma-gamma collider based on Compton back-scattering  

International Nuclear Information System (INIS)

A #gamma##gamma# collider would extend and complement the physics capability of a linear collider; e.g. it would be suitable for direct measurement of the partial decay width of a Higgs boson into two gamma quanta. This paper discusses choice of laser parameters, luminosity optimization, electron and laser parameters for a gamma- gamma collider as a second interaction region for the Next Linear Collider, laser path, and the lasers. It is concluded that a gamma- gamma collider is technically feasible; however it will require a significant investment in preparatory R ampersand D.

1996-08-25

404

Full potential linearized augmented plane wave calculations of structural and electronic properties of GeC, SnC and GeSn  

International Nuclear Information System (INIS)

A theoretical study of structural and electronic properties of GeC, SnC and GeSn is presented using the full potential linearized augmented plane wave method. In this approach, the generalized gradient approximation was used for the exchange-correlation potential. Results are given for lattice constant, bulk modulus and its pressure derivative in both zinc-blende and rocksalt structures. Band structure, density of states and band gap pressure coefficients in zinc-blende structure are also given. The results are compared with previous calculations and with experimental measurements.

2003-08-01

405

Design of optimal control under uncertain initial conditions: A minimax approach  

British Library Electronic Table of Contents (United Kingdom)

The need for a game-theoretical formulation of the problem of linear-quadratic control under nonmeasurable plant state where the functional depends on the uncertain initial state was substantiated. The minimax output control law in terms of linear matrix inequalities that may be regarded as the optimal robust control law for the given set of the plant initial states was established assuming that the measurable components of the initial state were known and the nonmeasurable components take on values within the given ellipsoid. The results obtained were generalized to the plants with uncertain parameters.

2009-01-01

406

Application of linear augemented plane wave method for technetium electronic structure calculation  

International Nuclear Information System (INIS)

By the linear augmented plane wave method (APW) the energy zone of silver and technetium structure is calculated. The potential has been determined by means of superposition of atomic charge densities according to slater exchange method. Total and partial state densities have been calculated by the tetrahedron method. The APW-method convergence on the example of silver is studied, the comparison with the calculation results by the APW method and other data is carried out. The APW method high efficiency is pointed out. In dipole approximation the intensity distribution in L"3, M"5 N"3 technetium emission spectra is calculated.

407

Analysis of the reactive power consumption and the harmonics in the network by the non-linear electrical loads  

Energy Technology Data Exchange (ETDEWEB)

The non linear electrical loads can give rise to a number of disturbances in electrical power networks. Among them, the high consumption of relative power is to be noted and so is the several harmonic components which may be injected in the industry system and very often in the utility system. So, by using appropriate technical considerations, as well as measurements in typical special electrical loads, such negative effects are analyzed and ways of minimizing them are suggested. (author) 3 refs., 11 figs., 6 tabs.

1994-12-31

408

Polyp measurement based on CT colonography and colonoscopy: variability and systematic differences  

Energy Technology Data Exchange (ETDEWEB)

To assess the variability and systematic differences in polyp measurements on optical colonoscopy and CT colonography. Gastroenterologists measured 51 polyps by visual estimation, forceps comparison and linear probe. CT colonography observers randomly assessed polyp size two-dimensionally (abdominal and intermediate window) and three-dimensionally (manually and semi-automatically). Linear mixed models were used to assess the variability and systematic differences between CT colonography and optical colonoscopy techniques. The variability of forceps and linear probe measurements was comparable and both showed less variability than measurement by visual assessment. Measurements by linear probe were 0.7 mm smaller than measurements by visual assessment or by forceps. The variability of all CT colonography techniques was lower than for measurements by forceps or visual assessment and sometimes lower (only ...

2010-06-15

409

Influence of anchor behaviour on the earthquake response of liquid storage tanks  

International Nuclear Information System (INIS)

The dynamic response of thin liquid storage tanks to earthquakes is a very complicated phenomenon, because it can be highly non linear. Among others, one can meet material and geometric non linearities of the tank shell leading eventually to static or dynamic buckling non linear behavior of anchor bolts, contact non-linearities due to the uplift of the tank base and to the unilateral character of the fluid pressure on the shell and high amplitude fluid oscillations. Moreover, linear or non linear soil structure interaction affects considerably the response of the fluid structure system under consideration. In this paper we focus attention on problems related only to the base uplift and anchors plastification. We study a tank similar to the Hualien project tank, but we neglect the soil structure interaction. The studied tank is representative of medium height to ...

410

Interrelation between grain boundary characteristics and intergranular stress corrosion cracking of thermally treated alloy 690 and shot peened alloy 800 in high temperature acidic and alkaline solution  

Energy Technology Data Exchange (ETDEWEB)

To clarify the acidic and alkaline Intergranular Stress Corrosion Cracking (IGSCC) mechanism of thermally treated alloy 690 (alloy 690 TT) and shot peened alloy 800 (alloy 800 SP), C-ring tests were conducted in deaerated HCl solutions and in deaerated NaOH solutions at 350degC, compared with the acidic and the alkaline IGSCC susceptibilities of mill-annealed alloy 600 (alloy 600 MA), full-sensitized one (alloy 600 FS) and thermally treated one (alloy 600 TT). Grain boundary characteristics, such as chromium depleted zone and chromium carbide precipitation, were examined using modified Huey test and Transmission Electron Microscopy. Potential-pH diagram for Ni, Cr, Fe-H{sub 2}O system at 350degC was constructed and the solubilities of NiO, Cr{sub 2}O{sub 3} and Fe{sub 3}O{sub 4} were also calculated to evaluate the stability of oxide films which were formed on the surfaces of alloy 690, 800 and 600. Under the acidic condition, the IGSCC susceptibility of alloy 800 ...

2001-05-01

411

Interrelation between grain boundary characteristics and intergranular stress corrosion cracking of thermally treated alloy 690 and shot peened alloy 800 in high temperature acidic and alkaline solution  

International Nuclear Information System (INIS)

To clarify the acidic and alkaline Intergranular Stress Corrosion Cracking (IGSCC) mechanism of thermally treated alloy 690 (alloy 690 TT) and shot peened alloy 800 (alloy 800 SP), C-ring tests were conducted in deaerated HCl solutions and in deaerated NaOH solutions at 350degC, compared with the acidic and the alkaline IGSCC susceptibilities of mill-annealed alloy 600 (alloy 600 MA), full-sensitized one (alloy 600 FS) and thermally treated one (alloy 600 TT). Grain boundary characteristics, such as chromium depleted zone and chromium carbide precipitation, were examined using modified Huey test and Transmission Electron Microscopy. Potential-pH diagram for Ni, Cr, Fe-H_2O system at 350degC was constructed and the solubilities of NiO, Cr_2O_3 and Fe_3O_4 were also calculated to evaluate the stability of oxide films which were formed on the surfaces of alloy 690, 800 and 600. Under the acidic condition, the IGSCC susceptibility of alloy 800 SP was high. The ...

2001-05-01

412

XENON-POISONING COMPUTER  

Science.gov (United States)

A computer was built for use with the NRU reactor to solve the problem of Xe/sup 135/ concentrations. The effect of any changes in reactor on Xe/sup 135/ concentration can be predicted and steps taken to avoid poisoning out. An electromechanical system was used for the computer to avoid the inherent disadvantages that electronic analog computers present for problems of very long solution times. The electromechanical analog computer has a high order of reliability and contains no vaccum tubes, commutators, slip rings, relays, or aluminum electrolytic capacitors. It is insensitive to transient disturbarce. In the event of failure of components or interruption of line voltage, it will retain existing information. The computer was designed for ~ 1% accuracy in Xe/ sup 135/ concentration readings. (W.D.M.)

1958-05-01

413

Wear modes active in angular contact ball bearings operating in liquid oxygen environment of the Space Shuttle turbopumps  

Energy Technology Data Exchange (ETDEWEB)

Extensive experimental investigation has been carried out on used flight bearings of the high pressure oxidizer turbopumps (HPOTP) of the space shuttle main engine (SSME) in order to determine the dominant wear modes, their extent, and causes. The paper presents the methodology, various surface analysis techniques used, results, and discussion. The mode largely responsible for premature bearing wear has been identified as adhesive/shear peeling of the upper layers of bearing balls and rings. This mode relies upon the mechanisms of scale formation, breakdown, and removal, all of which are greatly enhanced by the heavy oxidation environment of the HPOTP. Major causes of the high wear rates appear to be lubrication and cooling, both inadequate for the imposed conditions of operation. Numerous illustrations and evidence are provided. 22 refs.

1993-04-01

414

Transmission electron microscopy of undermined passive films on stainless steel  

Energy Technology Data Exchange (ETDEWEB)

A study has been made of the passive film remaining over pits on stainless steel using a high resolution transmission electron microscope. Type 305 stainless steel was passivated in a borate buffer solution and pitted in ferric chloride. Passive films formed at 0.2 V relative to a saturated calomel electrode were found to be amorphous. Films formed at higher potentials showed only broad diffraction rings. The passive film was found to cover a remnant lacy structure formed over pits passivated at 0.8 V. The metallic strands of the lace were roughly hemitubular in shape with the curved surface facing the center of the pit.

1999-06-01

415

Total synthesis of solanoeclepin A  

British Library Electronic Table of Contents (United Kingdom)

Cyst nematodes are troublesome parasites that live on, and destroy, a range of important host vegetable plants. Damage caused by the potato cyst nematode has now been reported in over 50 countries. One approach to eliminating the problem is to stimulate early hatching of the nematodes, but key hatching stimuli are not naturally available in sufficient quantities to do so. Here, we report the first chemical synthesis of solanoeclepin A, the key hatch-stimulating substance for potato cyst nematode. The crucial steps in our synthesis are an intramolecular cyclization reaction for construction of the highly strained tricyclo[5.2.1.01,6]decane skeleton (DEF ring system) and an intramolecular Diels???Alder reaction of a furan derivative for the synthesis of the ABC carbon framework. The present ...

2011-01-01

416

The minimal series of N=1 and N=2 superconformal topological field theory  

International Nuclear Information System (INIS)

We obtain conformal invariant topological field theories with N = 2 supersymmetry by twisting Sevrin, Troost and Van Proeyen's SU(2) x SU(2) x U(1) extended N = 4 superconformal field theories. We expect that the number of physical states is finite although the original N = 4 theories have continuous spectra. It is shown that the number of physical states is actually finite when the central charge c < 6 in the corresponding N = 4 theories. The physical states inherit the structure of the chiral ring in N = 2 superconformal minimal series which is obtained by the reduction from N = 4 theories. We also show that the algebra contains the topological N = 4 superconformal algebra as subalgebra. Therefore a closed set of a finite number of physical states in the topological N = 1 superconformal algebra can also be obtained. (orig.).

1991-06-01

417

The liquefaction of clayey soils under cyclic loading  

British Library Electronic Table of Contents (United Kingdom)

This paper seeks to investigate the liquefaction of clayey soils, a phenomenon that has been the trigger for many natural disasters in the last few decades, including landslides. Research was conducted on artificial clay?sand mixtures and natural clayey soils collected from the sliding surfaces of earthquake-induced landslides. The undrained response of normally consolidated clayey soils to cyclic loading was studied by means of a ring-shear apparatus. For the artificial clay?sand mixtures, it was found that the presence of a small amount of bentonite (?7%) would cause rapid liquefaction, while a further increase in bentonite content (?11%) produced the opposite effect of raising soil resistance to liquefaction by a significant degree. It was demonstrated that the bentonite?sand mixture wa...

2006-01-01

418

Synthetic enantiopure aziridinomitosenes: preparation, reactivity, and DNA alkylation studies.  

Science.gov (United States)

An enantiocontrolled route to aziridinomitosenes had been developed from l-serine methyl ester hydrochloride. The tetracyclic target ring system was assembled by an internal azomethine ylide cycloaddition reaction based on silver ion-assisted intramolecular oxazole alkylation and cyanide-induced ylide generation via a labile oxazoline intermediate (62 to 66). Other key steps include reductive detritylation of 26, methylation of the N-H aziridine 56, oxidation of the sensitive cyclohexenedione 68 to quinone 70, and carbamoylation using Fmoc-NCO. Although the aziridinomitosene tetracycle is sensitive, a range of protecting group manipulations and redox chemistry can be performed if suitable precautions are taken. A study of DNA alkylation by the first C-6,C-7-unsubstituted aziridinomitosene 11a has been carried out, and evidence for DNA cross-link formation involving nucleophilic addition to the quinone subunit is described. PMID:14677970

2003-12-24

419

Spin transition in octahedral metal complexes containing tetraazamacrocyclic ligands  

British Library Electronic Table of Contents (United Kingdom)

This review focusses on spin crossover complexes with octahedral metal ions which are bound to a tetraazamacrocyclic ligand and additionally either to two monodentate ligands or to one bidentate ligand. Macrocyclic ligands with a sufficiently large ring size prefer to coordinate to metal ions in an equatorial fashion yielding trans-octahedral coordination environments. In contrast, twelve-membered tetraazamacrocycles with high steric rigidity, such as 2,11-diaza[3.3](2,6)pyridinophanes or 2,11-dithia[3.3](2,6)pyridinophane, are prone to form cis-octahedral complexes. While the electronic and the steric properties of the coordinated tetraazamacrocycle in trans-octahedral complexes are very likely responsible for the paucity of observed spin transitions, the cis-octahedral coordination mode ...

2009-01-01

420

Solar energy modulator  

Energy Technology Data Exchange (ETDEWEB)

A module is described with a receiver having a solar energy acceptance opening and supported by a mounting ring along the optic axis of a parabolic mirror in coaxial alignment for receiving solar energy from the mirror, and a solar flux modulator plate for varying the quantity of solar energy flux received by the acceptance opening of the module. The modulator plate is characterized by an annular, plate-like body, the internal diameter of which is equal to or slightly greater than the diameter of the solar energy acceptance opening of the receiver. Slave cylinders are connected to the modulator plate for supporting the plate for axial displacement along the axis of the mirror thereby shading the opening with respect to solar energy flux reflected from the surface of the mirror to the solar energy acceptance opening.

1981-07-01

421

Simulation on Impact of Information Guidance on Regional Traffic Flow  

British Library Electronic Table of Contents (United Kingdom)

The traffic flow information guidance can improve the operating efficiency of regional traffic. On the basis of the information guidance model and survey data, this paper takes advantage of the VISSIM software to simulate the traffic in a region within the Southwest Second Ring of Beijing constructed by six roads and six intersections and makes a comparative evaluation on the operation of the regional road traffic flow before and after the implementation of the traffic flow information guidance measures. The analysis of five different guided flow cases shows that if the guided left-turn traffic flows in southbound I.A increases from 10% to 30%, the travel time of the left-turn traffic flow in southbound I.A has a reduction from 18% to 42%, and its delay also reduces from 234 s to 164 s. In...

2008-01-01

422

Selected topics in particle accelerators: Proceedings of the CAP meetings. Volume 5  

Energy Technology Data Exchange (ETDEWEB)

This Report includes copies of transparencies and notes from the presentations made at the Center for Accelerator Physics at Brookhaven National Laboratory Editing and changes to the authors` contributions in this Report were made only to fulfill the publication requirements. This volume includes notes and transparencies on nine presentations: ``The Energy Exchange and Efficiency Consideration in Klystrons``, ``Some Properties of Microwave RF Sources for Future Colliders + Overview of Microwave Generation Activity at the University of Maryland``, ``Field Quality Improvements in Superconducting Magnets for RHIC``, ``Hadronic B-Physics``, ``Spiking Pulses from Free Electron Lasers: Observations and Computational Models``, ``Crystalline Beams in Circular Accelerators``, ``Accumulator Ring for AGS & Recent AGS Performance``, ``RHIC Project Machine Status``, and ``Gamma-Gamma Colliders.``

1995-10-01

423

Scuffing behavior of gray iron and 1080 steel in reciprocating and rotational sliding  

British Library Electronic Table of Contents (United Kingdom)

Scuffing damage is catastrophic and typically not self-healing. It severely affects the life and reliability of engineering components, such as cams, roller bearings, piston rings, cylinder bores and gears. Gray iron and 1080 steel are important materials for these extremely demanding structural components. There have been several scuffing studies done in the past with various types of steel and cast iron. However, in these studies there was no attempt to compare the scuffing resistance of cast iron and steel materials with similar matrices. In the present study, scuffing tests were performed with the matrices of gray iron and 1080 steel being fully pearlitic. This allows for a direct evaluation of the effect of the graphite flakes on scuffing resistance. The scuffing behavior for these ma...

2011-01-01

424

Retention of ring structure in cyclopentane and alkylcyclopentane molecular cations  

Energy Technology Data Exchange (ETDEWEB)

All measurements were made with the NBS high-pressure photoionization mass spectrometer. The fractional of C/sub 5/H/sub 10//sup +/ions in a cyclopentane-cyclohexane mixture were determined as a function of pressure in order to define the fraction of the ions which did charge exchange with cyclohexane; i.e. the fraction which remained cyclic after ionization. The data for mixtures of various compositions (2.5 to 10% cyclohexane) are summarized for measurements performed at 10.62 eV: (a) 292K, > 96% cyclic; 347 K, greater than or equal to 94% cyclic; 386 K, 84 +- 4% cyclic; and 412 K, 78 +- 6% cyclic; entropy, enthalpy, and activation energy were determined; 10.49 eV was obtained as the ionization potential of cyclopentane. 1 figure.

1980-01-01

425

Resonance Raman and photophysical studies of transition metal complexes in solution and entrapped in zeolites  

Science.gov (United States)

We have obtained convincing evidence for localization of the optical electron on a single-ring fragment of a chelated bipyridine-like'' ligand (ie., pyridylpyrazine or 4-Methyl-bipyridine). In addition we have completed studies of Ru(bipyrazine){sub 3}{sup 2+} in aqueous sulfuric acid (0--98% by weight) and find clear evidence for sequential addition of six-protons to the six peripheral nitrogen atoms. Studies of zeolite-entrapped complexes are continuing and a series of homo- and heteroleptic complexes have been prepared and characterized. Finally, the synthesis of zeolite-entrapped metallophthalocyanines has now been developed and the copper and cobalt analogues synthesized. The characterization of these materials is now in progress.

1992-03-31

426

Recycler model magnet test on temperature compensation for strontium ferrite  

Energy Technology Data Exchange (ETDEWEB)

The Recycler ring magnet will be made of Strontium ferrite permanent magnets. A strontium ferrite permanent magnet without compensation has a temperature coefficient of -0.2 % in dB/dT. To compensate this effect, we are utilizing 30 % Ni 70 % Fe alloy, a temperature compensation ferromagnetic material with a low Curie point. To search for optimum commercially available material and optimum condition, we made a couple of simple model magnets, and tested with several different compensating material. The test results are reported and its optimal conditions are shown. Several different configurations were tested including a possible 2 kG magnet configuration.

1995-10-01

427

New advances and applications in pulsed-plasma nitriding of gear and power train systems; Neue Erkenntnisse und Anwendungen der Puls-Plasma-Nitriertechnik im Bereich Getriebe- und Antriebstechnik  

Energy Technology Data Exchange (ETDEWEB)

Due to size and costs of big slewing rings, the common methods of experimental trial and error together with destructive test methods for verification of the inductive hardening process are limited. Thereby it is essential to simulate the hardening process in addition to the tests. With these simulations, it should be possible to get conclusions for the hardening pattern, the residual stress and distortion. With actually existing methods a fully three dimensional simulation is extremely time consuming. For that reason, a new method was developed that combines two dimensional with three dimensional simulation to shorten the time for calculation tremendously. (orig.)

2010-09-15

428

Muon physics with the proposed Pulsed Lepton Source at LAMPF  

Energy Technology Data Exchange (ETDEWEB)

The Pulsed Lepton Source (PLS) project opens some exciting possibilities for muon and neutrino physics . The PLS would use the 0.25 4s proton pulses from the upgraded Proton Storage Ring (PSR) at LAMPF to create short, intense bursts of muons and neutrinos. The neutrino beam would be used for a few fundamentally important weak interaction physics experiments. The muon beams would find a wide variety of applications in both fundamental and applied'' muon physics areas. After a brief discussion of the physical layouts of the PSR and the proposed PLS in Sec. 2 and muon area in Sec. 3, we note some of the muon physics experiments and areas that could advantageously be addressed at the PLS in Secs. 4 and 5, and conclude in Sec. 6.

1992-01-01

429

Mismatch measurement and correction tools for the PS-SPS transfer of the 26GeV/C LHC beam  

CERN Document Server

TRANSVERSE EMITTANCE PRESERVATION IS A MAJOR CONCERN OF THE LHC INJECTOR CHAIN. MINIMISATION OF THE BLOW-UP DUE TO MISMATCH AT INJECTION INTO THE SPS IS THEREFORE MANDATORY. WHILE THE TRANSVERSE POSITIONN OF THE BEAM IN THE SPS INJECTION LINE IS MONITORED BUNCH BY BUNCH BY AN OTR (OPTICAL TRANSITION RADIATION) SCREEN AND A FAST CCD (CHARGED COUPLED DEVICE) CAMERA, THE PHASE SPACE MATCHING AT INJECTION IS MONITORED BY AN OTR BASED MISMATCH MONITOR IN THE SPS RING. ORTHOGONAL TUNING KNOBS WERE DEVELOPED TO TUNE INDEPENDENTLY TWISS PARAMETERS, DISPERSION AND DISPERSION DERIVATIVE. IN THIS PAPER WE DESCRIBE THE MISMATCH CORRECTION MECHANISM AS WELL AS THE TWO MONITORING SYSTEMS. WE REPORT ON FIRST MEASUREMENTS WHICH WERE CARRIED OUT DURING THE 1998 SPS RUN.

1999-01-01

430

Minimal Neutrino Beta Beam for Large theta_13  

CERN Document Server

We discuss the minimum requirements for a neutrino beta beam if theta_13 is discovered by an upcoming reactor experiment, such as Double Chooz or Daya Bay. We require that both neutrino mass hierarchy and leptonic CP violation can be measured to competitive precisions with a single-baseline experiment in the entire remaining theta_13 range. We find that for very high isotope production rates, such as they might be possible using a production ring, a (B,Li) beta beam with a gamma as low as 60 could already be sufficient to perform all of these measurements. If only the often used nominal source luminosities can be achieved, for example, a (Ne,He) beta beam from Fermilab to a possibly existing water Cherenkov detector at Homestake with gamma \\sim 190-350 (depending on the Double Chooz best-fit) could outperform practically any other beam technology including wide-band beam and neutrino factory.

2008-01-01

431

Mechanism of filler action in reducing the wear of PTFE polymer by differential scanning calorimetry  

British Library Electronic Table of Contents (United Kingdom)

Two types of representative nanometer materials, i.e., fibroid nanometer attapulgite and approximate spherical ultrafine diamond, were selected as fillers of polytetrafluoroethylene (PTFE) to study the mechanism of the wear-reducing actions of the fillers in PTFE composites. The friction and wear tests were performed on a block-on-ring wear tester under dry sliding conditions. Differential scanning calorimetry (DSC) was used to investigate material microstructure and to examine modes of failure. No significant change in coefficient of friction was found, but the wear rate of PTFE composites was orders of magnitude less than that of pure PTFE. DSC analysis revealed that nanometer attapulgite and ultrafine diamond played a heterogeneous nucleation role in PTFE matrix and consequently resulte...

2007-01-01

432

Ionized gas and radio emission in the barred Seyfert galaxy NGC 5728  

International Nuclear Information System (INIS)

This paper reports extensive new optical and radio observations of NGC 5728, emphasizing the central regions. Deep photographs revealing detail in the faint spiral arms are briefly discussed. Broad-band UBV CCD images obtained to examine the colors of the stellar populations that comprise the bar and central ring are presented. The velocity field and emission maps obtained from imaging spectroscopic measurements in the H-alpha emission line are discussed. Conventional long-slit spectra covering the ionized gas in the nuclear region are described. Detailed maps of the radio emission in the central regions of NGC 5728 are presented. These combined data provide considerable evidence for the inflow of gas into the nuclear region, in response to the nonaxisymmetric gravitational potential of the bar. The possible relation of this phenomenon to the Seyfert nature of NGC 5728 is also considered. 48 references.

433

Investigation of the removal efficiency of gasborne particles in a scrubber column  

Energy Technology Data Exchange (ETDEWEB)

Tests on the scrubbing column have led to the following results: Use of a scrubbing column with Raschig rings is only meaningful for the sedimentation of particles exceeding diameters of 0.5 ..mu..m; drops of diameter size 1.5 ..mu..m are formed in the column; more efficient drop precipitators in the column air flow ease the load on subsequent suspended material filters thereby contributing to a longer life of these filters even at higher sodium ion concentrations in the washing water; with distillate of an 8% rather than 0.8% salt solution a decontamination factor greater than 10 can be calculated since larger particles precipitate more readily. This only applies, however, under the condition that the washing water is renewed regularly, if necessary daily where higher aerosol concentrations are present. If not, the decontamination factor will be reduced through the salt-containing secondary aerosols from the washing water.

1983-01-01

434

Investigation of the removal efficiency of gasborne particles in a scrubber column  

International Nuclear Information System (INIS)

Tests on the scrubbing column have led to the following results: Use of a scrubbing column with Raschig rings is only meaningful for the sedimentation of particles exceeding diameters of 0.5 #mu#m; drops of diameter size 1.5 #mu#m are formed in the column; more efficient drop precipitators in the column air flow ease the load on subsequent suspended material filters thereby contributing to a longer life of these filters even at higher sodium ion concentrations in the washing water; with distillate of an 8% rather than 0.8% salt solution a decontamination factor greater than 10 can be calculated since larger particles precipitate more readily. This only applies, however, under the condition that the washing water is renewed regularly, if necessary daily where higher aerosol concentrations are present. If not, the decontamination factor will be reduced through the salt-containing secondary aerosols from the washing water. (orig.).

435

Investigation of Tumor-Peritoneal Interactions in the Pathogenesis of Peritoneal Metastases using a Novel Ex Vivo Peritoneal Model1  

British Library Electronic Table of Contents (United Kingdom)

BackgroundPeritoneal metastasis occurs in up to 30% of patients with gastric cancer. The aim of this experimental study is to develop and validate a novel ex vivo model of the human peritoneum to better identify factors involved in the development of peritoneal metastasis in order to improve its management and prognosis. MethodsPeritoneal discs harvested from hernia sacs obtained at inguinal hernia surgery were suspended in media using Teflon rings. Viability of the tissue was investigated using MTS assay, light and scanning electron microscopy (LM and SEM) over 72 h. To assess validity of the model, phenotypic changes in tumor cells were investigated. Changes in matrix metalloproteinases (MMP)-2 and -9 activities in HGC and AGS gastric adenocarcinoma cells after co-culture were investigat...

2010-01-01

436

Innovating methodologies brought into operation by Framatome for the Phenix control; Methodologies innovatrices mises en oeuvre par Framatome pour le controle de Phenix  

Energy Technology Data Exchange (ETDEWEB)

The renovation programme of the Phenix nuclear power plant (fast neutrons reactor situated at Marcoule) has for objective to ensure the reactor operation lengthening. In this frame, expertise and monitoring operation in situ of materials have been started. The presence of sodium and a temperature at the cold breakdown of the primary circuit between 150 and 180 degrees (Celsius) imply, for fast reactors, very special conditions. In this context, Framatome has realised three intervening in the area of nondestructive testing: the inspection of the cone-shaped support ring, the monitoring of the upper part of the primary vessel and the monitoring of the intermediary exchanger equipment. (N.C.)

2000-06-01

437

Hydrogen-atom attack on methyl viologen in aqueous solution studied by pulse radiolysis  

International Nuclear Information System (INIS)

Using hydrogen at high pressures of up to 150 bar as an OH scavenger in aqueous MV"2"+ solutions (pH 1) it is possible to differentiate between two kinds of transient formed simultaneously by H-atom attack on methyl viologen. One of them is assigned to an H adduct on the N atom, MV"+H"+, with absorption bands identical to those of the radical cation, MV"+. The MV"+H"+ species deprotonates forming the long-lived radical cation, MV"+. The second type of transient produced is attributed to an H-adduct on the ring carbon, MV"2"+H, decaying by second-order kinetics. The formation of MV"+ by electron transfer from the propan-2-ol radical has been reinvestigated (pH 0 to 7); its absorption spectrum does not change in this pH range. Rate constants and molar extinction coefficients are presented. (U.K.).

1984-01-01

438

High-tension corona controlled ozone generator for environment protection  

International Nuclear Information System (INIS)

Engineering details of a high voltage driven corona-plasma ozone generator are described. The plasma diode of generator has coaxial cylindrical geometry with cathode located inside anode. Cathode is made of a large number of radial gas nozzles arranged on central tubular mast which admits oxygen gas. The sharp endings of the nozzles along with a set of corona rings create the high electric field at the cathode required for formation of dense corona plume responsible for O_3 evolution. A model of coronal plasma generation and ozone production is presented. The plasma formation is strongly dependent on the electric field and temperature in side diode where a high electron density in a low temperature negative corona is suited for high ozone yields. These are established by suitable regulation of A-K gap, voltage, oxygen pressure, and cathode-nozzle population.

2010-02-01

439

High-Resolution Optical Coherence Tomography Findings in Solar Maculopathy and the Differential Diagnosis of Outer Retinal Holes  

British Library Electronic Table of Contents (United Kingdom)

PurposeTo characterize the morphology of outer retinal holes caused by solar maculopathy, using spectral-domain optical coherence tomography (SD-OCT). DesignThis study is an observational case series. MethodsThe SD-OCT findings of 3 patients (6 eyes) with chronic solar maculopathy are presented. ResultsSD-OCT demonstrates a characteristic appearance of partial-thickness hole(s) in the outer retina at the fovea. In 3 of 6 eyes, there is 1 hole directly beneath the umbo. In the remaining 3 eyes, there are multifocal holes spread across the fovea. Holes in more restricted layers, as had been previously reported with time-domain OCT, were not seen. In addition, advanced visualization of SD-OCT data demonstrates a hyperreflective ring around the outer retinal hole. ConclusionsSD-OCT can be used...

2011-01-01

440

High-Gain Lasing and Polarization Switch with a Distributed Optical-Klystron Free-Electron Laser  

International Nuclear Information System (INIS)

This Letter reports the first experimental results from the world's first distributed optical-klystron (DOK) free-electron laser (FEL), the DOK-1 FEL, at Duke University. The DOK-1 FEL is a hybrid system, comprised of four wigglers: two horizontal and two helical. With the DOK-1 FEL, we have obtained the highest FEL gain among all storage ring based FELs at 47.8% (#+-#2.7%) per pass. We have also demonstrated that the FEL gain can be enhanced by increasing electron bunching using wigglers with a different polarization. Furthermore, we have realized controlled polarization switches of the FEL beam by a nonoptical means through the manipulation of a buncher magnet.

2006-06-09

441

Gross decontamination experiment report  

International Nuclear Information System (INIS)

A Gross Decontamination Experiment was conducted on various levels and surfaces of the TMI - Unit 2 reactor building in March 1982. The polar crane, D-rings, missile shields, refueling canals, refueling bridges, equipment, and elevations 305' and 347'-6'' were flushed with low pressure water. Additionally, floor surfaces on elevation 305' and floor surfaces and major pieces of equipment on elevation 347'-6'' were sprayed with high pressure water. Selective surfaces were decontaminated with a mechanical scrubber and chemicals. Strippable coating was tested and evaluated on equipment and floor surfaces. The effectiveness, efficiency, and safety of several decontamination techniques were established for the large, complex decontamination effort. Various decontamination equipment was evaluated and its effectiveness was documented. Decontamination training and procedures were documented and evaluated, as were the support system and organization for the experiment.

442

Geometry effects in the pulsed magnetization of high-temperature superconductor bulk parts  

International Nuclear Information System (INIS)

The dynamic response of cylindrical and ring-shaped YBaCuO bulk parts to pulsed magnetic fields is calculated by using small sets of finite elements. Some comparisons with experimental results are provided, and they give confidence in the modelling of the superconducting properties. Transient magnetizations as a function of time and space as well as shapes and absolute values of trapped magnetic flux profiles are presented. The influence of the sample geometry is investigated for different millisecond pulsed magnetization processes. Results are reported for different radial thicknesses and heights, different pulse durations, peak magnetic fields and pulse sequences with and without stepwise cooling. Comparisons concerning the achievable trapped magnetic field and flux are made, and implications for the use of high-temperature superconductor bulk parts as cryo-permanent magnets in potential applications like electric machinery are discussed.

2005-02-01

443

Gamma-ray spectrometric analysis of nuclides formed in thorium by neutron irradiation  

International Nuclear Information System (INIS)

Gamma-ray spectrometric analysis was employed to determine the nuclides formed in thorium by neutron irradiation. Thorium sample was irradiated by neutron from a pure thermal neutron field, neutron field of Cd ratio of about 4, and epithermal neutron field, respectively. The former irradiation was carried out in a thermal neutron column provided for medical uses of neutrons, and the latters were done in the F-ring position of TRIGA II research reactor of Musashi Institute of Technology. The gamma-ray spectra were obtained and analyzed by employing a fully automatic gamma-ray analysis system named ''GAMA: giant frog:-SYSTEM'' developped by Musashi Institute of Technology. The formation of Pa-233 (U-233) was discussed quantitatively with respect to the difference of the neutron field. (author).

1985-02-01

444

Fundamental limits on beam stability at the advanced photon source  

International Nuclear Information System (INIS)

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

1998-12-10

445

First observation of excited states in the T_z=1/2 nucleus "8"5Mo  

International Nuclear Information System (INIS)

Excited states in the T_z=(1/2) nucleus "8"5Mo have been observed for the first time with the reaction "5"8Ni("3"2S,#alpha#n#gamma#) at 105 MeV. #gamma#-ray transitions in this nucleus have been assigned unambiguously by combining the information from the GASP #gamma#-ray array, the ISIS silicon ball, and the n-Ring neutron detector. Two band structures have been observed in this nucleus; they continue the smooth evolution of the known bands from the lighter N=43 isotones and have been tentatively assigned spins and parity on this basis. After reaching a maximum of collectivity at "8"3Zr, the trend with increasing mass is reversed, showing a smaller collectivity at "8"5Mo. The rotational behavior of the observed bands is discussed on the basis of the projected shell model calculations.

2002-03-01

446

Excess and deviation properties for the binary mixtures of methylcyclohexane with benzene, toluene, p-xylene, mesitylene, and anisole at T = (298.15, 303.15, and 308.15) K  

International Nuclear Information System (INIS)

Experimental data on density, viscosity, and refractive index at T = (298.15, 303.15, and 308.15) K, while speed of sound values at T = 298.15 K are presented for the binary mixtures of (methylcyclohexane + benzene), methylbenzene (toluene), 1,4-dimethylbenzene (p-xylene), 1,3,5-trimethylbenzene (mesitylene), and methoxybenzene (anisole). From these data of density, viscosity, and refractive index, the excess molar volume, the deviations in viscosity, molar refraction, speed of sound, and isentropic compressibility have been calculated. The computed values have been fitted to Redlich-Kister polynomial equation to derive the coefficients and estimate the standard errors. Variations in the calculated excess quantities for these mixtures have been studied in terms of molecular interactions between the component liquids and the effects of methyl and methoxy group substitution on benzene ring.

2006-12-01

447

Effects of carbon fiber surface treatment on the friction and wear behavior of 2D woven carbon fabric/phenolic composites  

British Library Electronic Table of Contents (United Kingdom)

To improve the friction and wear behavior of carbon fabric reinforced polymer composites (CFRP), nano-SiO2 was deposited on the fabric surface. The friction and wear behavior of the resulting composites were investigated on a model ring-on-block test rig. Experimental results revealed that fiber surface treatment contributed to largely improve the tribological properties of the CFRP composites. Scanning electron microscope (SEM) investigation showed that the worn surface of the surface modified CFRP composite was smoother under given load and sliding rate. Field emission scanning electron microscopy (FESEM), FTIR and X-ray photoelectron spectroscopy (XPS) studies of the carbon fiber surface showed that nanostructured Sio2 thin film can be obtained by SiO2 sols deposition, which improved th...

2009-01-01

448

Diesel exhaust inhalation induces heat shock protein 70 expression in vivo  

British Library Electronic Table of Contents (United Kingdom)

Exposure to urban air pollution is an independent risk factor for increased cardiovascular diseases. Heat shock protein 70 (HSP70) has been implicated in the pathogenesis of vascular dysfunction and cardiovascular diseases. This study has been designed to determine whether inhalation of urban air induces HSP70 expression in the lung and blood as well as the association of HSP70 and air pollution-induced vascular dysfunction. Apolipoprotein E (Apo-E) deficient mice were exposed to diesel exhaust (DE) either acutely (3 days, 200 or 400 g/m3 for 6 h/day) or chronically (7 weeks, 200 or 400 g/m3 for 6 h/day). HSP70 was measured in the lung using immunohistochemistry, and in the plasma by ELISA. Abdominal aorta rings were used to determine vascular functional responses. Chronic DE-exposure incr...

2011-01-01

449

Design of a far-infrared CHI wiggler free-electron laser  

Energy Technology Data Exchange (ETDEWEB)

The preliminary design of a far-infrared free-electron laser with a Coaxial Hybrid Iron (CHI) wiggler is presented. The CHI wiggler consists of a central rod and outer ring of alternating ferrite and dielectric spacers. A periodic wiggler field is produced when the CHI structure is immersed in an axial magnetic field. The design under investigation makes use of 1A, 1MV annular electron beam interacting with the TE{sub 01} coaxial waveguide mode at approximately 1 THz ({lambda} = 300 {mu}m). The nominal wiggler period is 0.5 cm and the inner and outer waveguide radii are 0.4 and 0.8 cm, respectively. An axial guide field of 5-10 kG is used. The device performance is modeled with slow-time-scale nonlinear code. Self fields and axial velocity spread are included in the model. Theoretical results will be presented.

1995-12-31

450

Design considerations for the magnetic system of a prototype x-ray free electron laser  

Energy Technology Data Exchange (ETDEWEB)

A number of difficult technical challenges need to be solved in the fields of accelerator and free-electron laser (FEL) technologies in order to build an X-ray FEL. One of the tasks well suited to the Advanced Photon Source Low Energy Undulator Test Line (LEUTL) is to take the intermediate step of solving some of the problems of single-pass FEL operation in the ultraviolet range. The existing Advanced Photon Source (APS) linac, in addition to its role of supply positrons for the APS storage ring, will also be used to generate the particle beam for the LEUTL. Here, the design of the magnetic system for the high gain soft x-ray free electron laser is described.

1997-04-01

451

Depth-profiling of vertical sidewall nanolayers on structured wafers by grazing incidence X-ray flourescence  

British Library Electronic Table of Contents (United Kingdom)

The Physikalisch-Technische Bundesanstalt (PTB), Germany's national metrology institute, developed an alignment strategy to specify elemental depth profiling in vertical sidewall layers on structured wafers. For this purpose, PTB's irradiation chamber for 200?mm and 300?mm silicon wafers was used to combine total-reflection X-ray fluorescence (TXRF) and grazing incidence XRF (GIXRF) techniques by employing monochromatized undulator radiation of the BESSY II electron storage ring. 3-D test structures were fabricated to develop an optimal alignment strategy allowing for depth profiling in such nanolayers. The test structures consisted of silicon bars with widths/spacings either in the ?m or in the nm range. In order to be able to differentiate the sidewalls more easily from the remainder of ...

2008-01-01

452

Demonstration of a Tunable-Bandwidth White Light Interferometer using Anomalous Dispersion in Atomic Vapor  

CERN Document Server

The concept of the 'white-light cavity' has recently generated considerable research interest in the context of gravitational wave detection. Cavity designs are proposed using negative (or anomalous) dispersion in an intracavity medium to make the cavity resonate over a large range of frequencies and still maintain a high cavity build-up. This paper presents the first experimental attempt and demonstration of white-light effect in a meter long ring cavity using an intracavity atomic medium. The medium's negative dispersion is caused by bi-frequency Raman gain in an atomic vapor cell. Although the white light condition was not perfectly achieved and improvements in experimental control are still desirable, significantly broad cavity response over bandwidth greater than 20 MHz has been observed. These devices will have potential applications in new generation laser interferometer gravitational wave detectors.

2006-01-01

453

Control of cooling during spray forming of bearing steel billets  

Energy Technology Data Exchange (ETDEWEB)

In an effort to minimize the distortion of bearing steel rings during the production process, 100Cr6 steel billets are spray formed with a unique cooling control system to control the cooling and solidification behavior of the deposits. Effects of heating around the deposits, gas cooling at the substrate bottom and the gas flow over the deposits are investigated both by numerical simulation and experiment. Porosity profiles and microstructures of spray formed bearing steel are examined and evaluated. The investigation results show that the thermal boundary conditions of the deposits play important roles on the cooling and solidification behavior of the deposits, especially at the deposit periphery. Porosity in the 100Cr6 bearing steel deposit can be reduced significantly with the special cooling control system.

2004-10-10

454

Coalification by clay-catalyzed oligomerization of plant monomers. [Methyleugenol  

Science.gov (United States)

During this report period, we have obtained a model of montmorillonite clay, and this model has been of great assistance in visualizing how the chemistry of substrate molecules might be altered as it occurs on the surface of the clay. A stereochemical representation of this montmorillonite model is shown. Of particular significance, this model indicates that hydroxyl groups are located in the center of each siloxane ring on the surface of the montmorillonite clay. These hydroxyl groups might serve to bond substrate molecules to the surface of the clay. The next step in our systematic examination of the radical cation-initiated dimerization of plant monomers from the C{sub 6}-C{sub 3} pool of shikimic acid metabolites was to study the dimerization of cinnamic acid and its derivatives. In the next block of research, we examined the reaction of montmorillonite clay (K-10) with methyleugenol. 2 refs.

1990-01-01

455

Characteristics of wave-particle interaction in a hydrogen plasma  

International Nuclear Information System (INIS)

We study the characteristics of cyclotron wave-particle interaction in a typical hydrogen plasma. The numerical calculations of minimum resonant energy Emin, resonant wave frequency ?, and pitch angle diffusion coefficient D?? for interactions between R-mode/L-mode and electrons/protons are presented. It is found that Emin decreases with ? for R-mode/electron, L-mode/proton and L-mode/electron interactions, but increase with ? for R-mode/proton interaction. It is shown that both R-mode and L-mode waves can efficiently scatter energetic (10 keV-100 keV) electrons and protons and cause precipitation loss at L=4, indicating that perhaps wave-particle interaction is a serious candidate for the ring current decay. (authors)

2008-09-01

456

Catalyzed oxidative degradation of methylene blue by in situ generated cobalt (II)-bicarbonate complexes with hydrogen peroxide  

British Library Electronic Table of Contents (United Kingdom)

Oxidative degradation of methylene blue (MB) by Co^2^+-HCO3^- system with H2O2 in aqueous solution was studied. Nearly complete decolorization of the dye was obtained in less than 50min in diluted NaHCO3 solution (25mM) in the presence of only 20mM Co^2^+ ions. Meanwhile, the conjugated structure and phenyl rings of the MB molecule were destroyed or even broken down into small organic acids and inorganic ions, as indicated by FT-IR spectra and ion-chromatography. Photoluminescence probing and radical scavenging technologies suggested that the reaction of MB degradation in this system mainly involved the generation and participation of hydroxyl radicals. Furthermore, by cyclovoltammetric measurements, the in situ formed different complexes between Co^2^+ and HCO3^- were observed at differen...

2011-01-01

457

Casimir repulsion beyond the dipole regime  

CERN Document Server

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

2011-01-01

458

Calculation of 3-D free electron laser gain: Comparison with simulation and generalization to elliptical cross section  

Energy Technology Data Exchange (ETDEWEB)

In the previous paper, we have derived a dispersion relation for the free electron laser (FEL) gain in the exponential regime taking account the diffraction and electron`s betatron oscillation. Here, we compare the growth rates obtained by solving the dispersion relation with those obtained by simulation calculation for the waterbag and the Gaussian models for the electron`s transverse phase space distribution. The agreement is found to be good except for the limiting case where the Rayleigh length is much longer than the gain length (1-D limit). We also generalize the analysis to the case where the electron beam cross section is elliptical as is usually the case in storage rings, and derive the first-order dispersion relation.

1992-08-01

459

CT findings of malignant lymphoma of the anterior mediastinum. Differentiation from invasive thymoma  

Energy Technology Data Exchange (ETDEWEB)

CT findings were compared retrospectively between 9 cases with malignant lymphoma of the anterior mediastinum and 8 cases with invasive thymoma. CT findings of malignant lymphoma were as follows: (1) The majority of the tumors were bilateral and extended beyond the anterior mediastinum to the other mediastinum compartments. (2) Their margin was either smooth or lobulated. (3) Their density was either homogeneous or heterogeneous. In the case with heterogeneous density, ring, triangle and/or band-like low density areas, just like interspace of fused lymph nodes, were demonstrated. Calcification or cysts could not be shown. (4) Patent inherent vessels without deviation were occasionally demonstrated running through the tumors. (5) The tumors faced and contacted widely to anterior chest wall and often pressed the lung laterally at the anterior parietomediastinal pleural reflection. (6) Pleural implants were not demonstrated. (author).

1989-04-01

460

Banana peel extract mediated synthesis of gold nanoparticles  

British Library Electronic Table of Contents (United Kingdom)

Gold nanoparticles were synthesized by using banana peel extract (BPE) as a simple, non-toxic, eco-friendly 'green material'. The boiled, crushed, acetone precipitated, air-dried peel powder was used to reduce chloroauric acid. A variety of nanoparticles were formed when the reaction conditions were altered with respect to pH, BPE content, chloroauric acid concentration and temperature of incubation. The reaction mixtures displayed vivid colors and UV-vis spectra characteristic of gold nanoparticles. Dynamic light scattering (DLS) studies revealed that the average size of the nanoparticles under standard synthetic conditions was around 300nm. Scanning electron microscopy and energy dispersive spectrometry (EDS) confirmed these results. A coffee ring phenomenon, led to the aggregation of th...

2010-01-01

461

BPS Condensates, Matrix Models and Emergent String Theory  

CERN Document Server

A prescription is given for computing anomalous dimensions of single trace operators in SYM at strong coupling and large $N$ using a reduced model of matrix quantum mechanics. The method involves treating some parts of the operators as "BPS condensates" which, in certain limit, have a dual description as null geodesics on the $S^5$. In the gauge theory, the condensate is similar to a representative of the chiral ring and it is described by a background of commuting matrices. Excitations around these condensates correspond to excitations around this background and take the form of ``string bits" which are dual to the "giant magnons" of Hofman and Maldacena. In fact, the matrix model approach gives a {\\it quantum} description of these string configurations and explains why the infinite momentum limit suppresses the quantum effects. This method allows, not only to derive part of the classical sigma model Hamiltonian of the dual string (in the infinite momentum ...

2007-01-01

462

Approach to the homoerythrina alkaloids using a tandem N-alkylation/azomethine ylide cycloaddition.  

Science.gov (United States)

Synthetic efforts toward the homoerythrina alkaloids 1-3 are described. Two separate model systems guided the pivotal [3 + 2] azomethine ylide cycloaddition cascade to form the A-C rings of these alkaloids. The cycloaddition precursors 63 and 68, prepared in nine and ten steps, respectively, from alkyne 47, each contain an enolizable ketone, a tethered electrophile, and an electron-poor dipolarophile. Heating 63 and 68 with the stannyl amine 17 generated demethoxyschelhammeridine 65 and demethoxyschelhammericine 70, the products of intramolecular azomethine ylide cycloadditions. Subsequent attempts to install the C-3 methoxy group of 1-3 are also described. PMID:17465572

2007-04-28

463

Antioxidant properties of 4-methylcoumarins in in vitro cell-free systems  

British Library Electronic Table of Contents (United Kingdom)

4-Methylcoumarins that possess two hydroxyl groups ortho to each other in the benzenoid ring have shown to have excellent antioxidant and radical-scavenging properties in different experimental models. Furthermore, they cannot be metabolized by the liver P450 monoxygenases and thus cannot form 3,4-coumarin epoxides, which are believed to be mutagenic. Herein, we present a study on the structure activity relationship of eight synthetic 4-methylcoumarins, carried out by employing a series of different chemical cell-free tests. These compounds were tested by means of three assays involving one redox reaction with the oxidant (DPPH assay, ABTS+ assay and FRAP). Other assays were employed to evaluate the antioxidant properties of the coumarins under investigation against NO, O2- and HClO, which...

2010-01-01

464

Annihilation of antiprotons in light nuclei  

CERN Document Server

CR-39 detectors have been exposed to a 5.9-MeV antiproton beam using the low energy antiproton ring (LEAR) facility at CERN. At this energy, tracks of antiprotons appear in a CR-39 detector after 135 min of etching in 6 M NaOH at 70C. Fluence of the antiproton beam has been determined using track density. We have also found tracks in the etched CR-39 detector at different depths (250-500 mum). These tracks have resulted from the annihilation of antiprotons with the constituents (H, C and O) of the CR-39 detector. The goal of the experiment is to develop a simple and low-cost method to study properties of antiparticles and those formed after annihilation of these particles with the target matter.

2006-01-01

465

Age determination of large live trees with inner cavities: radiocarbon dating of Platland tree, a giant African baobab  

British Library Electronic Table of Contents (United Kingdom)

? Introduction For large trees without a continuous sequence of growth rings in their trunk, such as the African baobab (Adansonia digitata L.), the only accurate method for age determination is radiocarbon dating. As of today, this method was limited to dating samples collected from the remains of dead specimens. ? Methods Our research extends significantly the dating of such trees to large live specimens with inner cavities. The new approach is based on collecting samples from the cavities and their subsequent radiocarbon dating. ? Results The giant two-stemmed Platland tree, also known as Sunland baobab, was investigated by using this new approach. AMS radiocarbon dates of the oldest sample segments originating from the two inner cavities indicate that the large stem I (364.5?m3) is 750...

2011-01-01

466

Two-gigawatt burst-mode operation of the intense microwave prototype (IMP) free-electron laser (FEL) for the microwave tokamak experiment (MTX)  

Energy Technology Data Exchange (ETDEWEB)

The MTX explored the plasma heating effects of 140 GHz microwaves from both Gyrotrons and from the IMP FEL wiggler. The Gyrotron was long pulse length (0.5 seconds maximum) and the FEL produced short-pulse length, high-peak power, single and burst modes of 140 GHZ microwaves. Full-power operations of the IMP FEL wiggler were commenced in April of 1992 and continued into October of 1992. The Experimental Test Accelerator H (ETA-II) provided a 50-nanosecond, 6-MeV, 2--3 kAmp electron beam that was introduced co-linear into the IMP FEL with a 140 GHz Gyrotron master oscillator (MO). The FEL was able to amplify the MO signal from approximately 7 kW to peaks consistently in the range of 1--2 GW. This microwave pulse was transmitted into the MTX and allowed the exploration of the linear and non-linear effects of short pulse, intense power in the MTX plasma. Single pulses were used to explore and gain operating experience in the ...

1993-10-06

467

The Next Linear Collider: NLC2001  

Energy Technology Data Exchange (ETDEWEB)

Recent studies in elementary particle physics have made the need for an e{sup +}e{sup -} linear collider able to reach energies of 500 GeV and above with high luminosity more compelling than ever [1]. Observations and measurements completed in the last five years at the SLC (SLAC), LEP (CERN), and the Tevatron (FNAL) can be explained only by the existence of at least one particle or interaction that has not yet been directly observed in experiment. The Higgs boson of the Standard Model could be that particle. The data point strongly to a mass for the Higgs boson that is just beyond the reach of existing colliders. This brings great urgency and excitement to the potential for discovery at the upgraded Tevatron early in this decade, and almost assures that later experiments at the LHC will find new physics. But the next generation of experiments to be mounted by the world-wide particle physics community must not only find this new physics, they must find out what it ...

2002-01-14

468

The non-linear fitting method to analyze the measured M-S plots of bipolar passive films  

Energy Technology Data Exchange (ETDEWEB)

Mott-Schottky (M-S) analysis is an effective approach to investigate the electronic property of passive films of metals, and it is well suitable for the passive film with single space charge capacitance. But there is no proper method to analyze the C{sub sc}{sup -2} vs. V{sub m} plots of passive films with several space charge capacitances in series connection, such as bipolar passive films. In this paper, the relationship between the space charge capacitance of the bipolar passive film and the applied potential was deduced and the features of corresponding plots were given out simultaneously. Accordingly, a non-linear fitting method was presented to analyze the C{sub sc}{sup -2} vs. V{sub m} plots of bipolar passive films. Then the method was used to study the semiconductor characteristics of bipolar passive films formed on the surface of Nickel base alloy after being corroded in the environments with high temperatures and high partial pressures of H{sub ...

2010-02-28

469

The non-linear fitting method to analyze the measured M-S plots of bipolar passive films  

International Nuclear Information System (INIS)

Mott-Schottky (M-S) analysis is an effective approach to investigate the electronic property of passive films of metals, and it is well suitable for the passive film with single space charge capacitance. But there is no proper method to analyze the Csc-2 vs. Vm plots of passive films with several space charge capacitances in series connection, such as bipolar passive films. In this paper, the relationship between the space charge capacitance of the bipolar passive film and the applied potential was deduced and the features of corresponding plots were given out simultaneously. Accordingly, a non-linear fitting method was presented to analyze the Csc-2 vs. Vm plots of bipolar passive films. Then the method was used to study the semiconductor characteristics of bipolar passive films formed on the surface of Nickel base alloy after being corroded in the environments with high temperatures and high partial pressures of H2S/CO2. The fitting results indicate that the ...

2010-02-28

470

Single charged top-pion production at next generation {gamma}{gamma} colliders  

Energy Technology Data Exchange (ETDEWEB)

The future e{sup +}e{sup -} linear colliders can also operate in the e{gamma} or {gamma}{gamma} modes. In the context of the top-color assisted technicolor (TC2) model, we study the single charged top-pion production process {gamma}{gamma} {yields} tb-bar{pi}{sub t}{sup -}. The results show that the production rates can reach the level of tens fb with reasonable parameter values. So one can expect that enough signals could be produced in future high-energy linear collider experiments. Furthermore, the flavor-changing (FC) decay mode {pi}{sub t}{sup -} {yields} bc-bar is the best channel to detect the charged top pion due to the clean standard model background. With a large number of events and the clean background, the charged top pion should be observable at future linear colliders operating in {gamma}{gamma} mode at the TeV energy scale.

2008-09-15

471

SLFP: A stochastic linear fractional programming approach for sustainable waste management.  

Science.gov (United States)

A stochastic linear fractional programming (SLFP) approach is developed for supporting sustainable municipal solid waste management under uncertainty. The SLFP method can solve ratio optimization problems associated with random information, where chance-constrained programming is integrated into a linear fractional programming framework. It has advantages in: (1) comparing objectives of two aspects, (2) reflecting system efficiency, (3) dealing with uncertainty expressed as probability distributions, and (4) providing optimal-ratio solutions under different system-reliability conditions. The method is applied to a case study of waste flow allocation within a municipal solid waste (MSW) management system. The obtained solutions are useful for identifying sustainable MSW management schemes with maximized system efficiency under various constraint-violation risks. The results indicate that SLFP can support in-depth analysis of the ...

2011-09-01

472

Probing the {ital H}{sup 3} vertex in {ital e}{sup +}{ital e}{sup {minus}}, {gamma}{ital e}, and {gamma}{gamma} collisions for light and intermediate Higgs bosons  

Energy Technology Data Exchange (ETDEWEB)

We study double Higgs boson production at future linear colliders while paying special attention to the option of high-energy and high-luminosity photon beams. The main purpose is to examine the feasibility of {ital e}{sup +}{ital e}{sup {minus}}, {gamma}{ital e}, and {gamma}{gamma} colliders in order to establish bounds on the value of triple Higgs coupling, which could be crucial for understanding a spontaneous breaking mechanism. We consider mainly those cases of light and intermediate Higgs bosons, including an analysis of the electroweak backgrounds. The mass range {ital M}{sub {ital H}}{approximately}{ital M}{sub {ital Z}} is discussed separately. It is shown that for a light Higgs boson the {ital H}{sup 3} coupling can be visible, even at a future linear {ital e}{sup +}{ital e}{sup {minus}} collider at 500 GeV. For an intermediate Higgs boson, a collider with TeV energies is suitable for investigations. We estimate the bounds on the ...

1996-12-01

473

Probing the H"3 vertex in e"+e"-, #gamma#e, and #gamma##gamma# collisions for light and intermediate Higgs bosons  

International Nuclear Information System (INIS)

We study double Higgs boson production at future linear colliders while paying special attention to the option of high-energy and high-luminosity photon beams. The main purpose is to examine the feasibility of e"+e"-, #gamma#e, and #gamma##gamma# colliders in order to establish bounds on the value of triple Higgs coupling, which could be crucial for understanding a spontaneous breaking mechanism. We consider mainly those cases of light and intermediate Higgs bosons, including an analysis of the electroweak backgrounds. The mass range M_H#approx#M_Z is discussed separately. It is shown that for a light Higgs boson the H"3 coupling can be visible, even at a future linear e"+e"- collider at 500 GeV. For an intermediate Higgs boson, a collider with TeV energies is suitable for investigations. We estimate the bounds on the anomalous H"3 coupling which can be experimentally established at future linear colliders. copyright 1996 ...

474

Parameters determination of IEC-TDG by directly solving non-linear equation; Chokusetsuho ni yoru IEC-TDG hakei kaiseki  

Energy Technology Data Exchange (ETDEWEB)

An IEC-TDG waveform analysis program that can accurately calculate the waveform parameters in waveforms containing much noise as well as waveforms based on the IEC 1083-2 standard was developed in the impulse voltage and current test field. In the conventional curve fitting method, it is difficult to solve the non-linear equation directly when obtaining waveform parameters from the assigned discrete data. An approximate solution method is low in precision. Therefore, the residual between the standardized data and approximate function was calculated for high-speed Fourier transformation. Unrelated components were eliminated from the calculated frequency spectrum to synthesize waveforms. An L-M method is used for analysis. The solution is first tracked by a maximum diving method. If the convergence is judged to have been largely promoted, the method is switched into a Newton method to continue the calculation. The non-linear equation in a curve ...

1997-04-20

475

Onset of convection in a couple-stress fluid-saturated porous medium: effects of non-uniform temperature gradients  

Energy Technology Data Exchange (ETDEWEB)

Onset of convection in a layer of couple-stress fluid-saturated porous medium is investigated for different types of basic temperature gradients. The boundaries are considered to be adiabatically insulated to temperature perturbations. The eigenvalue equations of the perturbed state obtained from the normal mode analysis are solved analytically using a regular perturbation technique with wave number as a perturbation parameter and also numerically using the Galerkin technique. The critical stability parameters obtained from these two techniques are in excellent agreement and an increase in the value of couple-stress parameter is found to delay the onset of convection. The results also indicate that the piecewise linear temperature profile hastens the onset of convection when compared to linear, parabolic, and inverted parabolic temperature profiles. In addition, the influence of thermal depth on the critical conditions is assessed in the case ...

2010-08-15

476

Linear augmented-plane-wave calculation of the structural properties of bulk Cr, Mo, and W  

International Nuclear Information System (INIS)

A scalar-relativistic procedure for calculating the valence-electron contribution to the total energy of bulk and thin-film solids has been developed and applied to the fcc and bcc phases of the group-VIB transition elements Cr, Mo, and W. This approach, which is based on the linear augmented-plane-wave method and local-density-functional theory, contains no shape approximations for either the charge density or potential. The formulation adopts a rigid-core approximation and incorporates an exact treatment of the core-charge tails that extend beyond the muffin-tin spheres. The application of this procedure to bcc Cr, Mo, and W yields calculated lattice parameters and bulk moduli that are in good (Cr) to excellent (Mo and W) agreement with experiment. The present calculated properties also agree quite well with the results of previous calculations involving a variety of band-structure methods. The calculated fcc-bcc energy difference for Cr, Mo, and W increases in a ...

477

General order characteristic methods for solving neutron transport problems  

Energy Technology Data Exchange (ETDEWEB)

The neutron transport equation in Cartesian geometry possesses straight line characteristics along which the streaming operator can be written as a full differential in terms of the characteristic length. This idea was used by Lathrop to develop the step characteristic method, which he showed to be positive definite but less accurate than conventional Diamond-Difference schemes. Several authors since then have developed new methods utilizing the characteristic curves (including non-Cartesian geometry). A Linear Characteristic Method, based on a more consistent linear representation of the incoming-surface and within-cell angular flux, has been developed and tested in two-dimensional geometry producing highly accurate and computationally efficient results. A similar linear method, with several modifications, was developed for three-dimensional Cartesian geometry, and implemented in ORNL`s production code TORT. In this paper ...

1992-12-31

478

Full-potential self-consistent linearized-augmented-plane-wave method for calculating the electronic structure of molecules and surfaces: O_2 molecule  

International Nuclear Information System (INIS)

The linearized-augmented-plane-wave (LAPW) method for thin films is generalized by removing the remaining shape approximation to the potential inside the atomic spheres. A new technique for solving Poisson's equation for a general charge density and potential is described and implemented in the film LAPW method. In the resulting full-potential LAPW method (FLAPW), all contributions to the potential are completely taken into account in the Hamiltonian matrix elements. The accuracy of the method: already well known for clean metal surfaces: is demonstrated for the case of a nearly free (noninteracting) O_2 molecule which is a severe test case of the method because of its large anisotropic charge distribution. Detailed comparisons show that the accuracy of the FLAPW results for O_2 exceeds that of existing state-of-the-art local-density linear-combination-of-atomic-orbitals (LCAO)-type calculations, and that taking the full potential LAPW results ...

479

Estimating $\\omega$ from Galaxy Redshifts Linear Flow Distortions and Nonlinear Clustering  

CERN Document Server

We propose a method to determine the cosmic mass density Omega from redshift-space distortions induced by large-scale flows in the presence of nonlinear clustering. Nonlinear structures in redshift space such as fingers of God can contaminate distortions from linear flows on scales as large as several times the small-scale pairwise velocity dispersion sigma_v. Following Peacock & Dodds (1994), we work in the Fourier domain and propose a model to describe the anisotropy in the redshift-space power spectrum; tests with high-resolution numerical data demonstrate that the model is robust for both mass and biased galaxy halos on translinear scales and above. On the basis of this model, we propose an estimator of the linear growth parameter beta = Omega^0.6/b, where b measures bias, derived from sampling functions which are tuned to eliminate distortions from nonlinear clustering. The measure is tested on the numerical data and found to recover ...

1997-01-01

480

Electron flow in the SABRE linear induction adder in positive polarity  

International Nuclear Information System (INIS)

In a positive polarity induction adder each of the induction cavities is a cathode, which emits electrons at a unique potential. These broad spectrum electrons strongly affect Magnetically Insulated Transmission Line (MITL) behavior. Electron flow decreases the cavity-to-MITL coupling efficiency, and reduces the power transport efficiency along the system. Also, the operating impedance of the MITL is lowered, reducing the diode impedance required for good coupling and good total system power efficiency. It is therefore imperative to understand the details of MITL electron flow. In previous work, measurement of MITL electron flow for a twenty-stage linear induction adder (Hermes III), operated in positive polarity, was compared with simulations. There was qualitative agreement, but some differences were noted. For example, measured electron flow in the first cavities was greater than in the simulations. The authors have extended the work on this subject with ...

1993-05-17

481

Dynamic response of peats. Final research report  

Energy Technology Data Exchange (ETDEWEB)

The objective of this project were to investigate the dynamic behavior of peat and to evaluate the influence of that behavior on the dynamic response of peat deposits. During the course of the research, the objectives were expanded to explore the effects of strong earthquake shaking on pile foundations embedded in peat deposits. An experimental investigation was undertaken using samples of a peat deposit typical of many large peat deposits in western Washington. A series of ground response analyses was performed to investigate the seismic response of peat deposits. Three vertical profiles through Mercer Slough were analyzed using both equivalent linear and nonlinear ground response analyses. The analyses showed that the soft nature of the Mercer Slough peat would produce amplification of the long-period components of an earthquake ground motion. Comparison of the equivalent linear and nonlinear ground response analyses showed that the ...

1996-11-01

482

Development of nanometer resolution C-Band radio frequency beam position monitors in the Final Focus Test Beam  

Energy Technology Data Exchange (ETDEWEB)

Using a 47 GeV electron beam, the Final Focus Test Beam (FFTB) produces vertical spot sizes around 70 nm. These small beam sizes introduce an excellent opportunity to develop and test high resolution Radio Frequency Beam Position Monitors (RF-BPMs). These BPMs are designed to measure pulse to pulse beam motion (jitter) at a theoretical resolution of approximately 1 nm. The beam induces a TM{sub 110} mode with an amplitude linearly proportional to its charge and displacement from the BPM's (cylindrical cavity) axis. The C-band (5,712 MHz) TM{sub 110} signal is processed and converted into beam position for use by the Stanford Linear Collider (SLC) control system. Presented are the experimental procedures, acquisition, and analysis of data demonstrating resolution of jitter near 25 nm. With the design of future e{sup +}e{sup -} linear colliders requiring spot sizes close to 3 nm, understanding and developing RF-BPMs ...

1998-08-01

483

Development of highly reliable screening by using x-ray fluorescence spectrometry. Applications to determine lead in tin plated and tin-bismuth plated samples  

International Nuclear Information System (INIS)

A highly reliable screening method was developed for the determination of lead in tin plated layers and tin-bismuth plated layers. The contents of lead in the layers of the various samples were determined by inductively coupled plasma optical emission spectrometry. The calibration curve for lead in the tin and tin-bismuth plated layers by using WD-XRF exhibited linear correlation from 130 #mu#g/g to 2070 #mu#g/g. Calibration curve of lead normalized with Pb-L#alpha#/Sn-K#alpha# intensity was more linear, and this method was possible to evaluate very small sample. The calibration curve for lead in the tin plated layers by using ED-XRF was good linearly, but it for lead in the tin-bismuth plated layers was affected by Pb-L#alpha# spectrum and Bi-L#alpha# spectrum overlap each other. It was effective for decreasing affect of Bi-L#alpha# spectrum by using curve fitting method. (author)

2009-03-01

484

Blind source separation of convolutive mixtures of non circular linearly modulated signals with unknown baud rates  

CERN Document Server

This paper addresses the problem of blind separation of convolutive mixtures of BPSK and circular linearly modulated signals with unknown (and possibly different) baud rates and carrier frequencies. In previous works, we established that the Constant Modulus Algorithm (CMA) is able to extract a source from a convolutive mixture of circular linearly modulated signals. We extend the analysis of the extraction capabilities of the CMA when the mixing also contains BPSK signals. We prove that if the various source signals do not share any non zero cyclic frequency nor any non conjugate cyclic frequencies, the local minima of the constant modulus cost function are separating filters. Unfortunately, the minimization of the Godard cost function generally fails when considering BPSK signals that have the same rates and the same carrier frequencies. This failure is due to the existence of non-separating local minima of the Godard cost function. In order ...

2011-01-01

485

Application of optimal regulator design method through the inverse problem approach to the power system stabilizer design  

Energy Technology Data Exchange (ETDEWEB)

The theory and application of the optimal control of linear systems to stabilize or improve the system stability is well known. For an optimal linear regulator design, the arbitrariness involved in the parameters of the cost function always affects the final control law and the closed-loop system poles which decide the system dynamic characteristics. A new approach, 'The inverse problem approach' has been developed to overcome this difficulty. The system so designed will have preassigned closed-loop poles and the resulting closed-loop system performance can be ensured. In this paper the inverse problem approach for optimal regulator design is applied to the power system stabilizer (PSS) design for single-machine infinite-bus systems. The results show that, as far as the linearized model is concerned, systems designed by the inverse problem approach have better closed-loop performance than those designed by ...

1991-02-01

486

Analysis of non-Gaussian CMB maps based on the N-pdf. Application to WMAP data  

CERN Document Server

We present a new method based on the N-point probability distribution (pdf) to study non-Gaussianity in cosmic microwave background (CMB) maps. Likelihood and Bayesian estimation are applied to a local non-linear perturbed model up to third order, characterized by a linear term which is described by a Gaussian N-pdf, and a second and third order terms which are proportional to the square and the cube of the linear one. We also explore a set of model selection techniques (the Akaike and the Bayesian Information Criteria, the minimum description length, the Bayesian Evidence and the Generalized Likelihood Ratio Test) and their application to decide whether a given data set is better described by the proposed local non-Gaussian model, rather than by the standard Gaussian temperature distribution. As an application, we consider the analysis of the WMAP 5-year data at a resolution of around 2 degrees. At this angular scale (the ...

2008-01-01

487

A new approach to the prediction of the thermodiffusion for linear chain hydrocarbon binary mixtures  

Energy Technology Data Exchange (ETDEWEB)

Many attempts have been made to generate reliable thermodiffusion coefficient models for binary mixtures. This paper presented a simple analytical model for the prediction of thermal diffusion coefficients in linear chain hydrocarbon binary mixtures using the thermodynamics of irreversible process. More specifically, the model represented the net heat transport, or the energy of detaching a molecule from its neighbours in the region of the binary mixture minus the energy given up in that region when one molecule fills a hole, and examined its accuracy by comparing theoretical results with available experimental data for linear chain hydrocarbon binary mixtures. The new model was based on phenomenological and kinetic approaches which have been found to be the most reliable. The paper discussed the net heat of transport for each component in the binary mixtures and presented the results of the investigation. The perturbed chain statistical ...

2009-07-01

488

2001 Report on the Next Linear Collider  

Energy Technology Data Exchange (ETDEWEB)

Recent studies in elementary particle physics have made the need for an e{sup +}e{sup -} linear collider able to reach energies of 500 GeV and above with high luminosity more compelling than ever [1]. Observations and measurements completed in the last five years at the SLC (SLAC), LEP (CERN), and the Tevatron (FNAL) can be explained only by the existence of at least one particle or interaction that has not yet been directly observed in experiment. The Higgs boson of the Standard Model could be that particle. The data point strongly to a mass for the Higgs boson that is just beyond the reach of existing colliders. This brings great urgency and excitement to the potential for discovery at the upgraded Tevatron early in this decade, and almost assures that later experiments at the LHC will find new physics. But the next generation of experiments to be mounted by the world-wide particle physics community must not only find this new physics, they must find out what it ...

2001-08-28

489

The crystal structure of YPdSi, the isotopic compounds LnPdSi (Ln=Gd-Lu), and their structural relation to some other equiatomic compounds of the rare earth and transition metals with main group elements  

International Nuclear Information System (INIS)

The nine title compounds were prepared from the elements by arc-melting and subsequent heat treatment in resistance and high-frequency furnaces. The crystal structure of these isotypic compounds was determined for YPdSi from single-crystal X-ray diffractometer data: Pmmn, a = 430.8(1) pm, b = 1391.2(1) pm, c = 743.1(1) pm, Z = 8, R = 0.024 for 417 structure factors and 40 variable parameters. The crystal structures of the isotypic compounds GdPdSi and ErPdSi were also refined from single-crystal data. The structure is of a new type. It consists of condensed, six-membered rings of alternating palladium and silicon atoms with Pd-Si bond distances varying between 249.6 and 258.8 pm. These two-dimensionally infinite nets are connected to each other via weak Pd-Si and Si-Si bonds with bond distances of 276.3 and 259.5 pm. The rare earth atoms are situated above and below the six-membered palladium-silicon rings in a manner as it is known for the ...

490

Synthesis, structural characterization, and performance evaluation of resorcinol-formaldehyde (R-F) ion-exchange resin  

International Nuclear Information System (INIS)

The 177 underground storage tanks at the DOE's Hanford Site contain an estimated 180 million tons of high-level radioactive wastes. It is desirable to remove and concentrate the highly radioactive fraction of the tank wastes for vitrification. Resorcinol-formaldehyde (R-F) resin, an organic ion-exchange resin with high selectivity and capacity for the cesium ion, which is a candidate ion-exchange material for use in remediation of tank wastes. The report includes information on the structure/function analysis of R-F resin and the synthetic factors that affect performance of the resin. CS-100, a commercially available phenol-formaldehyde (P-F) resin, and currently the baseline ion-exchanger for removal of cesium ion at Hanford, is compared with the R-F resin. The primary structural unit of the R-F resin was determined to consist of a 1,2,3,4-tetrasubstituted resorcinol ring unit while CS-100, was composed mainly of a 1,2,4-trisubstituted ring. ...

2004-09-10

491

Space charge field in a FEL with axially symmetric electron beam  

Energy Technology Data Exchange (ETDEWEB)

Nonlinear two-dimensional theory of the space charge of an axially symmetric electron beam propagating in combined right-hand polarized wiggler and uniform axial guide fields in a presence of high-frequency electromagnetic wave is presented. The well-known TE{sub 01} mode in a cylindrical waveguide for the model of radiation fields and paraxial approximation for the wiggler field are used. Space charge field components are written in the Lagrange coordinates by the twice averaged Green`s functions of two equally charged infinitely thin discs. For that {open_quotes}compensating charges{close_quotes} method is applied in which an electron ring model is substituted by one with two different radii and signs discs. On this approach the initial Green`s functions peculiarities are eliminated and all calculations are considerably simplified. Coefficients of a twice averaged Green`s function expansion into a Fourier series are obtained by use of corresponding expansion ...

1995-12-31

492

Radioiodination of 3-quinuclidinyl benzilate using a no-carrier-added concentration of iodine-125/sodium-iodine  

Energy Technology Data Exchange (ETDEWEB)

3-Quinuclidinyl benzilate (QNB) is a potent muscarinic antagonist that binds to muscarinic acetylcholine receptors. Iodination of QNB is difficult because it contains rings that are deactivated, while phenol rings are activated. The purpose of this research is to develop an appropriate method for the iodination of QNB at no-carrier-added concentrations of /sup 125/I/NaI. Phenol was chose as the test compound for direct iodination by adding chloramine T and nonradioactive sodium iodide to the phenol in a phosphate buffer and methanol system. A simple method to radioiodinate QNB at several concentrations was developed in situ in the presence of QNB, thallic trifluoroacetate /sup 125/I/NaI, /sup 127/I/NaI, and aluminium chloride. Using milligram amounts of QNB (7.12 x 10/sup -6/ moles), three reaction steps were involved: QNB was reacted with thallic trifluoroacetate at 60/sup 0/C for 24 hours, then radioactive /sup 125/I/NaI and aluminium ...

1986-01-01

493

Photographic surface photometry of NGC 2855 and NGC 6771 galaxies  

International Nuclear Information System (INIS)

Photographic surface photometry in the BV system was carried out two Southern SO's galaxies, NGC 2855 and NGC 6771. B and V isophote maps were obtained as well as geometric and integrated parameters as position angles, inclination, diameters, magnitudes and integrated colors. Each luminosity profile was decomposed into bulge and disk contributions, each component being fitted to convenient laws. For NGC 2855 de Vaucouleurs law described well the bulge whereas the disk showed an exponential distribution. For NGC 6771 the barred nuclear bulge as well as the disk was best fitted by exponential laws. Additional luminosity components due to an inner fragmented ring were identified in NGC 2855 and due to both a quite prominent lens and well defined ring in NGC 6771. In this galaxy the minor axis, oriented almost edge-on, present clues of another luminosity component besides the bulge and the thin disk. For both galaxies the disk central surface ...

2009-05-10

494

Construction and alignment experience of Indus-1 SRS in C.A.T  

International Nuclear Information System (INIS)

A 450 MeV Synchrotron Radiation Source, Indus-1 is being constructed at Centre for Advanced Technology at Indore in central India. This paper narrates our experience in construction and alignment of synchrotron machines which was first of its kind for most of us. Careful design, planning and execution of the work yielded modest results so that alignment accuracies between 0.1 to 0.3 mm could be achieved (in booster synchrotron) and, which have proved to be adequate up till now. The building of the SRS complex was constructed such that machine rings have their foundations isolated from rest of the building. A number of 100 x 150 mm size steel plates were embedded in the concrete of floor and walls to serve as base for reference surveying marks which were established later. The pre-injector and booster ring are enclosed in a radiation shielding zone with separate ventilation system. Dipoles, quadrupoles and a few sextupoles were fiducialised ...

1996-01-01

495

Characterization and properties of monoammine nitroimidazole complexes of platinum (PtCl sub 2 (NH sub 3 )(NO sub 2 Im)). Crystal and molecular structure of cis-Amminedichloro(1-((((2-hydroxyethyl)amino)carbonyl)methyl)-2-nitroimidazole)platinum(II)  

Energy Technology Data Exchange (ETDEWEB)

The characterization of monoammine(nitroimidazole)platinum(II) complexes of structure (PtCl{sub 2}(NH{sub 3})(NO{sub 2}Im)) (NO{sub 2}Im = 1-((((2-hydroxyethyl)amino)carbonyl)methyl)-2-nitroimidazole, Etanidazole (I), 1-(2-nitro-1-imidazolyl)-3-methoxy2-propanol, Misonidazole (II), and 1-(2-hydroxyethyl)-2-methyl-5-nitroimidazole, Metronidazole (III)) is reported. Both is cis and trans isomers may be isolated for II and III. The crystal structure of cis-amminedichloro(1-((((2-hydroxyethyl)amino)carbonyl)methyl)-2-nitroimidazole)platinum(II) has been determined by X-ray diffraction. The crystals are orthorhombic, space group Pnab with cell dimensions a = 14.867 (7) {angstrom}, b = 9.915 (5) {angstrom}, c = 19.015 (9) {angstrom}, and Z = 8. The structure was refined to R = 0.062 and R{sub w} = 0.052. Platinum has the expected square-planar coordination. The Pt-Cl bond trans to the nitroimidazole ligand is shorter (2.269 (3) {angstrom}) than normal. The dihedral angle between the platinum ...

1991-11-27

496

Application of the Green's function method to some nonlinear problems of an electron storage ring: Part 1, The Green's function for the Fokker-Planck equation  

Energy Technology Data Exchange (ETDEWEB)

For an electron storage ring the beam size evaluation including beam-beam interaction gives an example of such a problem. Another good example is finding the beam size for a nonlinear machine. The present work gives a way to solve some of these problems, at least in principle. The approach described here is an application of the well known Green's function method, which in this case is applied to the Fokker-Planck equation governing the distribution function in the phase space of particle motion. The new step made in this paper is to consider the particle motion in two degrees of freedom rather than in one dimension, a characteristic of all the previous work. This step seems to be necessary for an adequate description of the problem, at least for the class of problems which are considered below. This work consists of the formal solution of the Fokker-Planck equation in terms of its Green's function and describing the Green's function ...

1982-07-01

497

Accelerators for proton and heavy ion radiotherapy  

Energy Technology Data Exchange (ETDEWEB)

The construction of Heavy Ion Medical Accelerator in Chiba (HIMAC) at the National Institute of Radiological Sciences was completed in December 1993. HIMAC consists of an injector linac, two synchrotron rings, a high energy beam transport system and a beam irradiation system. Its accelerator parameters are based on the medical requirement, and helium, carbon, neon, silicon and argon were selected as the accelerated ion species. It has 3 therapy rooms (A{approx}C). Room A has a vertical irradiation system, Room C horizontal and Room B both vertical and horizontal. Two rings can supply beams independently to the vertical and horizontal irradiation systems. Clinical trial started on June 21 1994, after several basic biological and physics experiments lasting about 2 months. Cancer is the top cause of death in Japan since 1981, and people expect good treatment results at HIMAC. Proton and heavy ion radiotherapy has the advantage of dose ...

1995-03-01