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

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).

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 ...

Science.gov (United States)

PMID:21370327

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

Science.gov (United States)

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

KoreaScience (Korea)

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KoreaScience (Korea)

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Energy Technology Data Exchange (ETDEWEB)

We study the low energy expansion of the nucleon`s electroweak form factors in the framework of an effective chiral Lagrangian including pions, nucleons and the {Delta}(1232). We work to third order in the so-called small scale expansion and compare the results with the ones previously obtained in the chiral expansion. In addition, these calculations serve as a first exploratory study of renormalization and decoupling within the small scale expansion. (orig.) 35 refs.

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 ...

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 ...

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 ...

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.

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.

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 ...

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

Science.gov (United States)

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

Energy Technology Data Exchange (ETDEWEB)

An Experimental study was performed to investigate flow characteristic of multi-stage expansion valve applied with inverter heat pump. Multi-stage expansion consists of parallel valve which is controlled on/off type of solenoid valve. Expansion valve open one solenoid the other closed in low frequency region and open two solenoid valve in high frequency region. In rated frequency region always open one solenoid valve and control period and on-off time ratio for the other solenoid valve. Flow characteristics of a orifice expansion was measured as a function of orifice diameter and operating conditions. As a results multi-stage expansion device can control a stable flow with period and on-off time ratio. (author). 4 refs., 7 figs., 1 tab.

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.

UK PubMed Central (United Kingdom)

Spinocerebellar ataxia 10 (SCA10) is an autosomal dominant disease caused by large-scale expansions of the (ATTCT)_n repeat within an intron of the human ATXN10 gene. In contrast...Full Text Available

UK PubMed Central (United Kingdom)

After emergence, adult flies and other insects select a suitable perch and expand their wings. Wing expansion is governed by the hormone bursicon and can be delayed under adverse environmental...Full Text Available

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 ...

Energy Technology Data Exchange (ETDEWEB)

Thermal expansions of a simulated fuel (SS-1) were measured by using a Dilatometer (DIL402C) from room temperature to 1900 K. The main procedure of an uncertainty evaluation followed the strategy of the UO{sub 2} fuel. Referring to the ISO (International Organization for Standardization) guide, the uncertainties of the thermal expansion were quantified in three parts - the initial length, the length variation, and the system calibration factor. The uncertainty of the thermal expansion for a simulated fuel was also compared with those of UO{sub 2} fuel.

KoreaScience (Korea)

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International Nuclear Information System (INIS)

The Planning Process of Brazilian Electric Sector Expansion, their normative aspects, instruments, main agents and the planning cycles are described. The methodology of expansion planning is shown, with the interactions of several study areas, electric power market and the used computer models. The forecasts of methodology evolution is also presented. (C.G.C.).

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 ...

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, ...

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)

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 ...

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 ...

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).

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.

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, ...

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.

International Nuclear Information System (INIS)

Developed is a simple method alloing one to determine the k-loop coefficient of #beta# function in gauge theories provided the operator expansion is constructed in (k-1) loop for certain two-point functions. The calculation of the two-loop coefficient of the Gell-Mann-Low function becomes trival - it reduces to a few algebraic operations with expressions which are already known. As an example spinor, scalar and supersymmetric electrodynamics are considered. Although the corresponding results for #beta#"("2") are known in the literature, both the method of the calculations and some points referring to the construction of the operator expansion are novel.

Energy Technology Data Exchange (ETDEWEB)

A fast production scheduling algorithm suitable for generation expansion studies is described in this paper. It can handle several independent rivers, thermal plants, pumped storage plants, import, export, and internal non-firm markets. Inflows and load are deterministic and a one-reservoir limit is imposed on each river. The scheduling problem is formulated as a generalized network problem which is efficiently solved by an adaption of the simplex method. The algorithm is part of a program developed by Hydro-Quebec to conduct preliminary evaluations of alternative expansion plans. The program and the scheduling algorithm are presented.

Science.gov (United States)

A silicon solar cell assembly comprising a large, thin silicon solar cell bonded to a metal mount for use when there exists a mismatch in the thermal expansivities of the device and the mount.

UK PubMed Central (United Kingdom)

In most adult tissues there reside pools of stem and progenitor cells inside specialized microenvironments referred to as niches. The niche protects the stem cells from inappropriate expansion...Full Text Available

Energy Technology Data Exchange (ETDEWEB)

The present emphasis on inherent safety for LMR designs has resulted in a need to represent the various reactivity feedback mechanisms as accurately as possible. The dominant negative reactivity feedback has been found to result from radial expansion of the core for most postulated ATWS events. For this reason, a more detailed model for calculating the reactivity feedback from radial core expansion has been recently developed for use with the SASSYS/SAS4A Code System. The purpose of this summary is to present an extension to the model so that it is more suitable for handling a core restraint design as used in FFTF, and to compare the SASSYS/SAS4A results using this model to the empirical correlation presently being used to account for radial core expansion reactivity feedback to FFTF.

Science.gov (United States)

Fire-driven deforestation is the major source of carbon emissions from Amazonia. Recent expansion of mechanized agriculture in forested regions of Amazonia ...

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

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.

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 ...

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 ...

Energy Technology Data Exchange (ETDEWEB)

This invention relates to an automatically-operating wedge block for maintaining intimate structural contact over wide temperature ranges, including cryogenic use. The wedging action depends on the relative thermal expansion of two materials having very different coefficients of thermal expansion. The wedge block expands in thickness when cooled to cryogenic temperatures and contracts in thickness when returned to room temperature.

International Nuclear Information System (INIS)

The Grueneisen parameter and lattice thermal expansion of the A-15 compounds V_3Si and V_3Ge at room temperature are evaluated on the basis of the method due to Brugger and Fritz from the third order elastic constants reported earlier. The calculated values are compared with available experimental values and are found to fit satisfactorily. (author).

UK PubMed Central (United Kingdom)

The aim of this study was to investigate cumulus expansion, nuclear maturation and expression of connexin 43, cyclooxygenase-2 and FSH receptor transcripts in equine cumuli oophori during in vivo and...Full Text Available

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 ...

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.

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.

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 ...

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 ...

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

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 ...

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

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 ...

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).

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

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...

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

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

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.

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 ...

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.

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.

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.

British Library Electronic Table of Contents (United Kingdom)

Using a novel, pulsed micro-second time-resolved photoacoustic (PA) instrument, we measured thermal dissipation and energy storage (ES) in the intact cells of wild type (WT) Chlamydomonas reinhardtii, and mutants lacking either PSI or PSII reaction centers (RCs). On this time scale, the kinetic contributions of the thermal expansion component due to heat dissipation of absorbed energy and the negative volume change due to electrostriction induced by charge separation in each of the photosystems could be readily distinguished. Kinetic analysis revealed that PSI and PSII RCs exhibit strikingly different PA signals where PSI is characterized by a strong electrostriction signal and a weak thermal expansion component while PSII has a small electrostriction component and large thermal expansion....

Energy Technology Data Exchange (ETDEWEB)

Restructuring of power system has changed the traditional planning objectives and introduced challenges in the field of Transmission Expansion Planning (TEP). Due to these changes, new approaches and criteria are needed for transmission planning in deregulated environment. Therefore, in this paper, a dynamic expansion methodology is presented using a multi-objective optimization framework. Investment cost, congestion cost and reliability are considered in the optimization as three objectives. To overcome the difficulties in solving the non-convex and mixed integer nature of the optimization problems, a Non-Dominated Sorting Genetic Algorithm (NSGA II) approach is used followed by a fuzzy decision making analysis to obtain the final optimal solution. The planning methodology has been demonstrated on the IEEE 24-bus test system and north-east of Iran national 400 kV transmission grid to show the feasibility and capabilities of the proposed ...

International Nuclear Information System (INIS)

Three new classes of finite, homogeneous and nonsingular solutions of Einstein's equations which have time-dependent expansion, shear and rotation are presented. The t-constant sections are of Bianchi type IX. The source of these geometries is a fluid which has not been thermalized. (Author).

Science.gov (United States)

This paper examines the current military working dogs (MWD) program, its historical roots, and the possibility for expansion of the program. Current service MWD programs will be discussed, as well as possible models for change. The primary focus is on the...

Energy Technology Data Exchange (ETDEWEB)

Previous analyses of binary cycles for conversion of geothermal energy from moderate temperature resources to electrical energy have shown potential gains in net geofluid effectiveness on the order of 8%, resulting from selection of turbine-expansion processes whose equilibrium states pass through the two-phase region. If condensation occurs, this gain could be reduced or eliminated by the resulting loss in turbine efficiency. Experience with many fluids, however, indicates that vapor supersaturation permits metastable pure-vapor states to exist at temperatures considerably below the saturation temperature at a given pressure; thus, by better understanding the condensation process, and properly structuring the cycle, substantial performance gains may be possible. The purpose of the present study was to assess the probability for attaining this performance gain by estimating the extent of condensation which might be expected during such an ...

UK PubMed Central (United Kingdom)

Hematopoietic stem and progenitor cell (HSPC) expansion is regulated by intrinsic signaling pathways activated by cytokines. The intracellular kinase JAK2 plays an essential role in cytokine signaling,...Full Text Available

International Nuclear Information System (INIS)

The systems for which the algebra of gauge transformations in the lagrangian formalism is closed, are considered. The hamiltonian BRST charge and the BRST-invariant hamiltonian are found explicitly. Their expansions in powers of the ghost variables contain, in general, an infinite number of terms. (orig.).

UK PubMed Central (United Kingdom)

BackgroundExpansion of aquaculture is seriously limited by reductions in fish oil (FO) supply for aquafeeds. Terrestrial alternatives such as vegetable oils (VO) have been investigated...Full Text Available

UK PubMed Central (United Kingdom)

A rapid expansion of urban systems, particularly in less-developed countries, pose considerable challenges. Urbanization also provides opportunities for socio-economic progress. Relative contribution...Full Text Available

International Nuclear Information System (INIS)

The present emphasis on inherent safety for liquid-metal reactor designs has resulted in a need to represent the various reactivity feedback mechanisms as accurately as possible. The dominant negative reactivity feedback has been found to result from radial expansion of the core for most postulated anticipated transient without scram events. For this reasons, a more detailed model for calculating the reactivity feedback from radial core expansion, including subassembly bowing has been recently developed for use with the SASSYS/SAS4A code system. The purpose of this summary is to present an extension to the model so that it is more suitable for handling a core restraint design as used in the Fast Flux Test Facility (FFTF), and to compare the SASSYS/SAS4A results using this model to the empirical correlation presently being used to account for radial core expansion reactivity feedback in the FFTF.

Energy Technology Data Exchange (ETDEWEB)

The Sunshine Project of Japan was inaugurated in 1974. Since 1980 it has been promoting priority projects such as coal liquefaction. Japan is now promoting the basic and applied research that underpins this development and is increasing the efficiency of technical development. With regard to risk dispersion, the expansion of international cooperation such as the IEA is being promoted.

Energy Technology Data Exchange (ETDEWEB)

Densities were measured with a vibrating-tube densimeter for binary mixtures of dimethyl sulfoxide + thiophene at temperatures from 293.15 to 313.15 K as a function of composition. Molar excess volumes V[sup E] for the mixtures, determined from the density data, are negative and become more negative with an increase in temperature. The coefficients of thermal expansion were also evaluated from the temperature dependence of the density.

Energy Technology Data Exchange (ETDEWEB)

This article describes the steps taken to mitigate the impact to existing wetlands by creating new wetlands in an airport expansion project. The project addressed maintaining suitable amounts of wetlands to accommodate peak waterfowl populations, moving of high voltage power transmission towers, and maintaining agricultural and hunting interests. This project involved recreating of open water areas, marsh habitat, mud flat habitat, saline meadow habitat, maintaining two existing wetlands in the area of the new wetlands without disturbing them, and improving upland habitat surrounding the new wetlands.

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 ...

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 ...

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 ...

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 ...

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 ...

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 ...

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 ...

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 ...

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.

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

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 describe the motivation ...

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 ...

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.

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.

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.

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.

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)

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.

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...

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.

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.

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...

International Nuclear Information System (INIS)

In this study, SnO2 thin films have been grown using spray pyrolysis technique on glass substrates under a substrate temperature (Ts = 440 oC). The precursors were methanol CH4O and anhydrous tin tetrachloride. XRD analyses yielded strong (1 1 0)-(1 0 1)-(2 0 0) X-ray diffraction peaks which are characteristics to tetragonal crystals. Atomic Force Microscopy (AFM) analyses showed the existence of clusters with particular pyramidal shapes. The main part of this study concerns the optical measurements of transmittance T(?) and reflectance R(?) spectra inside 250-1800 nm domain. Conjoint optical and thermal properties were deduced using the Amlouk-Boubaker Opto-Thermal Expansivity ?AB. The obtained value: ?AB ? 23.4 m3 s-1 helped situating the performance of the as-grown SnO2 compound among most known PV-T oxides like ZnO and TiO2.

International Nuclear Information System (INIS)

A one-dimensional numerical model for the expansion of impact-produced vapor clouds is used to investigate magnetic field generation mechanisms in events such as meteor collisions with the moon. The resulting cloud properties, such as ionization fraction, electrical conductivity, radial expansion velocity, mass density, and energy density are estimated. The model is initiated with the peak shock states and pressure thresholds for incipient and complete vaporization of anorthosite lunar surface materials by iron and GA composition meteorites. The expansion of the spherical gas cloud into a vacuum was traced with a one-dimensional explicit lagrangian hydrodynamic code. The hypervelocity impact plasmas produced are found to be significant in the amplitudes and orientations of the magnetic fields generated. An ambient magnetic field could have been provided by the core dynamo, which would have interacted with the expanding ...

Science.gov (United States)

A detailed model for the dynamic resistivity of an exploding conductor presents many difficulties. An electrically-exploded conductor undergoes significant hydrodynamic expansion as it is heated. Resistivity is a function of both the temperature and density of a conductor and realistic models for resistivity over the range of parameter space experienced by an exploding conductor are quite complex. See for example, the model of Lee and More (1984). Calculation of the hydrodynamic expansion of the conductor during and subsequent to the explosion is likewise dependent on detailed knowledge of the equation of state for the conductor in a range where few experimental data exist. A further complication is the strong magnetic field which couples the hydrodynamic expansion to the currents flowing in the expanding material. In spite of the difficulties, progress is being made on detailed modeling of fuses and exploding conductors ...

Energy Technology Data Exchange (ETDEWEB)

Production of cermet nuclear fuel having fine uranium dioxide (UO{sub 2}) particles dispersed in matrix metal requires basic property data on the compatibility of matrix metal with fission product compounds. It is thermodynamically suggested that, as burnup increases, cesium in oxide fuel reacts with the fuel, other fission products or cladding pipe and produces cesium uranates, cesium molybdate, or cesium chromate in stainless steel cladding pipe. Attempt was made to measure the thermal expansion coefficient and thermal conductivity of cesium uranates (Cs{sub 2}UO{sub 4} and Cs{sub 2}U{sub 2}O{sub 7}), cesium molybdate (Cs{sub 2}MoO{sub 4}) and cesium chromate (Cs{sub 2}CrO{sub 4}). Thermal expansion was measured by X-ray diffraction and determined by Cohen`s method. Thermal conductivity was obtained by measuring thermal diffusion by laser flash method. The thermal expansion of Cs{sub 2}UO{sub 4} and Cs{sub 2}U{sub 2}O{sub ...

Energy Technology Data Exchange (ETDEWEB)

By tests about pipe failure under extreme bending, moment at cross sections affected by circumferential cracks, admissible strains for securing the integrity in the area of a flow link are indicated. These are 7% for austenic and ferritic materials in the undisturbed cross section. From d/t-ratios of 20 onwards the strains are limited by pipe bulging on the pressure-load side. In this connection, circumferential flaws do not have any influence on the behaviour on the strained side, when their expansion does not exceed the investigated limitis of <60 circumferential expansion and crack depth of 0,3 t. (orig.)

International Nuclear Information System (INIS)

Elastic scattering cross sections of keV protons in solids (Z=3-82) are calculated using the partial wave expansion technique and the ''muffin-tin'' bound-atom potential. The differential cross sections for small scattering angles of less than 10deg are smaller than those with the Ziegler-Biersack-Littmark potential at all energies and for all solids, although, for larger angles, the two cross sections agree with each other. The mean free paths of the protons in the solids, obtained from the total cross sections, decrease very slowly with decreasing energy. Furthermore, at low energies they approach half the nearest-neighbor distance, which is taken as the radius of the augmented plane wave sphere in the muffin-tin model of crystalline solids. (orig.).

British Library Electronic Table of Contents (United Kingdom)

In 1946, the Philippines raised claims in the South China Sea over an area already known as Spratly Islands. This claim advanced through peculiar stages, starting when Thomas Cloma allegedly discovered islands in 1946, later named as Freedomland, and maturing to some extent in 1978 by the governments claim over the so-called Kalayaan Island Group. Considered as an oceanic expansion of its frontiers, this paper reviews the basis of the claim, first over the nature of Clomas activities, and secondly over the measures the Philippine government took as a reaction of Clomas claim of discovery of an area already known in western cartography as the Spratlys. Eventually, what is the nature of the link between the 1978 Kalayaan Islands Groups official claim and 1956 Clomas private one?

Energy Technology Data Exchange (ETDEWEB)

New phosphates with NaZr{sub 2}(PO{sub 4}){sub 3} structure of the B{sub 0.5}FeTa(PO{sub 4}){sub 3}-type (where B-Ca, Sr, Ba) are synthesized and characterized by X-ray diffraction analysis and IR-spectroscopy. The heating behavior of the phosphates is studied using high-temperature X-ray crystallography in the range 15-625 deg. C. The unit-cell parameters, the coefficients of thermal expansion {alpha}{sub a}, {alpha}{sub c} and their thermal expansion anisotropy |{alpha}{sub c} - {alpha}{sub a}| of the phosphates under study are determined and the dependences of these characteristics on the nature of cations are established and analyzed.

Energy Technology Data Exchange (ETDEWEB)

The findings reported in this study highlight several important features of the development of hematopoietic stem cells after transplantation into irradiated recipients. First, they demonstrate the existence of a class of primitive multipotential stem cells that can function for a significant portion of the lifetime of a mouse (15 mo). In addition, they clearly show that these primitive stem cells can be infected with recombinant retroviruses and thus would be appropriate targets for gene therapy in somatic tissues. Second, our data indicate that the progeny of some, but not all, of the primitive stem cells have fully expanded into the various hematopoietic lineages by 2 mo after reconstitution. Finally, our analysis of the secondary recipients provides strong evidence suggesting that the primitive stem cell population can actually clonally expand. Our current experiments are aimed at determining the extent to which this expansion can occur and whether or not this ...

International Nuclear Information System (INIS)

In this paper, we show how to improve and extend the integration by fractional expansion technique (IBFE) by applying it to certain families of scalar massive Feynman diagrams. The strategy is based on combining this method together with the integration by parts technique. In particular, we want to calculate certain Feynman diagrams which have a triangle loop as a subgraph. The main idea is to use the integration by parts technique in this subgraph in order to simplify the topology of the original diagram in which it is immersed, using then, in a second step, the IBFE technique. The result we have obtained, after the application of both techniques, represents a simplification in the complexity of the solution, compared with having used only the IBFE technique.

International Nuclear Information System (INIS)

An extensive analysis of the 1/N expansion of O(N)-symmetric lambdaphi"4 theory in four dimensions shows it to be a consistent approximation method. It is confirmed that the ground state of the theory is O(N(-symmetric, and that spontaneous symmetry breaking is not possible in the large-N limit. The Green's functions are free of tachyons if constructed relative to this ground state. A natural upper bound is derived for the parameters of the theory to ensure the existence of a ground state. In the strong-coupling domain there exist a bound state and a resonance in the identity representation of the O(N) group, which disappear in the weak-coupling regime. It is shown that, to leading order in N, a zero-mass interacting ''charged'' boson cannot be sustained in this theory. If the boson mass goes to zero, the model becomes a free-field theory.

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

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

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.

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.

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, ...

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.

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.

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 ...

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)

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.

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

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.

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.

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.

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).

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.

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.

International Nuclear Information System (INIS)

This paper describes various eddy current probes, and their performance, which were developed at the Chalk River Laboratories of Atomic Energy of Canada. Included are probes for detecting defects at tubesheet regions in heat exchanger tubes, defects at expansion-transition regions in finned tubes, and defects in ferromagnetic tubes. All of these probes can be used with conventional commercially available instruments. (author).

International Nuclear Information System (INIS)

A Bianchi type-IX cosmological model has been found as a solution of Einstien's vacuum field equations with a cosmological constant. The solution represents a rotating generalziation fo the de Sitter universe. This universe shows a transition to exponential expansion and the vorticity begins to decay exponentially at the grand-unified-theory time. The point of time for this transition is independent of the magnitude of the vorticity. During the Guth inflationary era the vorticity decays by a factor of the order 10"-"1"4"2.

Energy Technology Data Exchange (ETDEWEB)

The emission of Cerenkov radiation by tachyons has been examined by using the reduced expansions of superluminal electromagnetic fields in terms of standard helicity representation of Poincare group. It has been shown that the tachyons emit Cerenkov radiation through their coupling only with subluminal electromagnetic fields and that a charged tachyon can emit Cerenkov radiation only in the media in which it travels with a velocity lower than that of light while in the usual medium in which its velocity is more than that of light, it will never emit Cerenkov radiation.

Energy Technology Data Exchange (ETDEWEB)

Lorentz invariant theory of second quantization of superluminal electromagnetic fields has been constructed in purely group theoretical manner by using the reduced expansion of four-vector fields for imaginary mass system in terms of standard helicity representations of Poincare group. It has been shown that the usual relationship of spin and statistics need not be inverted for Lorentz invariance of the theory of spin-1 tachyons. 15 refs.

Energy Technology Data Exchange (ETDEWEB)

We describe exact cosmological solutions with rotation and expansion in the low-energy effective string theory. These models are spatially homogeneous (closed Bianchi type IX) and they belong to the family of shear-free metrics which are causal (no closed timelike curves are allowed), admit no parallax effects and do not disturb the isotropy of the background radiation. The dilaton and the axion fields are nontrivial, in general, and we consider both cases with and without the central charge (effective cosmological constant)

Energy Technology Data Exchange (ETDEWEB)

In this note we prove to all orders in the small scale expansion that all off-shell parameters which appear in the chiral effective Lagrangian with explicit DELTA(1232) isobar degrees of freedom can be absorbed into redefinitions of certain low-energy constants and are therefore redundant.

International Nuclear Information System (INIS)

To simulate the effects of the breakup channel on rearrangement amplitudes, the conventional coupled-reaction-channel (CRC) expansion is augmented by pseudoreaction channels. The construction of the projector for the extended CRC space is discussed, and transition-operator equations on this space are given. By solving the full and post-approximation forms of the CRC equations for a model three-particle problem, the crucial role played by the nonorthogonality terms is demonstrated.

International Nuclear Information System (INIS)

The compound UC_2Si_2 has been found to be ferromagnetic at low temperatures with a Curie temperature of 101"0K. The magnetization follows a Curie-Weiss law in the paramagnetic region with an effective magneton number of 2.12 Bohr magnetons per uranium atom. Partial substitution of Th atoms for the U atoms results in an expansion of the lattice, a rapid drop in the Curie temperature, and a sizable increase in the coercive field.

International Nuclear Information System (INIS)

Experimental data in the Kondo lattice YbPd_2Si_2 is compared with the results of a hybridization model, based ont he 'large degeneracy expansion' approximation, which takes into account the crystal field level splittings of the Yb ion. We show that satisfactory agreement is obtained with a unique set of crystal field and hybridization parameters. (orig.).

International Nuclear Information System (INIS)

The Hungarian Power Companies Ltd. has been using the IAEA planning methodologies since 1985 when it acquired the WASP model. Since then this model has been applied on a regular basis to determine the least cost expansion plan of the power generating system of the country. This report describes this experience as well as the application of the WASP model for other types of studies. (author).

International Nuclear Information System (INIS)

A distinguishing design feature of CANDU nuclear reactors is the use of horizontal fuel channels housed in a horizontal vessel called a calandria, which is made of stainless steel 304L. Each channel consists of a Zr-2.5%Nb alloy pressure tube and an externally concentric Zr-2 calandria tube. The calandria tubes are joined to the end plates (tubesheets) of the calandria vessel by joints formed by roller expansion. The bores in the tubesheets are grooved. Roller expanded joints provide a cost effective means of joining dissimilar materials, require minimal space and no maintenance. The quality of these roller expanded joints is important from a sealing, strength and stress corrosion point of view. The roller expansion process consists of expanding the calandria tubes to deform them plastically against the bores and into the grooves of the tubesheets. Therefore, understanding the effect of the number, geometry and the pitch of the grooves on the ...

Energy Technology Data Exchange (ETDEWEB)

This heat exchanger is a critical step in the development of the Externally Fired Combined Cycle power system, a direct-coal combustion power plant (gas turbine). SiC is the only material with the needed resistance to creep, thermal shock, and oxidation; however a protective coating is needed. Ten candidate materials were identified: alumina-based materials, materials stable with SiO, and low expansion materials. An initial screening study should be performed.

UK PubMed Central (United Kingdom)

The DNA-binding properties of Ru(bpy)₂(eilatin)²⁺ have been investigated to determine if the sterically expansive eilatin ligand confers specificity for destabilized single-base...Full Text Available

CERN Document Server

An S-brane solution with two non-composite electric branes and a set of l scalar fields is considered. The intersection rule for branes corresponds to the Lie algebra A_2. The solution contains five factor spaces with the fifth one interpreted as ``our'' 3-dimensional space. It is shown that there exists a time interval where accelerating expansion of ``our'' 3-dimensional space is compatible with small enough value of effective gravitational ``constant'' variation.

Energy Technology Data Exchange (ETDEWEB)

Angular wave functions are investigated which describe the motion of two electrons in the field of a nucleus at fixed equal distances from electrons to the nucleus. Calculation methods are considered that include matching of power series and expansion in series of Legendre polynomials. Asymptotic properties of solutions at small large distances are determined.

Energy Technology Data Exchange (ETDEWEB)

We discuss the determination of the infrared singularities of massive one-loop 5-point functions with Mellin-Barnes (MB) representations. Massless internal lines may lead to poles in the {epsilon} expansion of the Feynman diagram, while unresolved massless final state particles give endpoint singularities of the phase space integrals. MB integrals are an elegant tool for their common treatment. An evaluation by taking residues leads to inverse binomial sums. (orig.)

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 Pol equation with a non-linear restoring force. This ...

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 ...

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...

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 ...

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 ...

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)

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 ...

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.

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...

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 ...

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 ...

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 ...

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.)

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.).

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.).

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.

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.

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.

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.).

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.

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.

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.

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.

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).

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.))

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.

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 ...

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 ...

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 ...

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 ...

Energy Technology Data Exchange (ETDEWEB)

In January 2001, Husky Oil Operations Limited (Husky), in joint-venture with Petro-Canada submitted a Development Application (DA) to the Canada-Newfoundland and Labrador Offshore Petroleum Board (C-NLOPB) for the White Rose Development. This DA was prepared following the Canada-Newfoundland Atlantic Accord Implementation Act and the Canada-Newfoundland and Labrador Atlantic Accord Implementation Newfoundland and Labrador Act. In December 2001, the C-NLOPB approved the White Rose DA. This document outlined a proposed amendment to the original Development Plan involving an expansion of its White Rose Development in the Jeanne d'Arc Basin on the Grand Bank. The expansion will consist of a subsea tie-back to the Floating Production, Storage and Offloading (FPSO) vessel through the existing Southern Glory Hole (SGH) and utilizing a new glory hole constructed approximately 4 km south of the SGH. The document presented an overview of the ...

Energy Technology Data Exchange (ETDEWEB)

Discussions were given on the characteristics of a diesel engine to emit unburned hydrocarbon (HC) created in a long idling operation. The engine tested in the experiment is a direct injection diesel engine with six water-cooled were investigated varying the jet hole diameter and length of the jet nozzle. In the initial operation period, the HC showed high values. This is thought because part of the injected fuel has deposited on the wall because of low combustion chamber wall temperature, and the fuel deposit that did not evaporate during combustion evaporated during expansion process and emitted unburned. The head was dismantled to investigate the carbon flowers deposited on the nozzle and the relationship between the carbon and the HC deposited on the head face and the combustion chamber wall. It was clarified that the HC increase was phenomenal compared with that of the carbon. This is because the injected fuel was adsorbed into the carbon, part of it remained ...

Energy Technology Data Exchange (ETDEWEB)

Samples of nylon 66 rods were irradiated using a cobalt-60 gamma ray source at a dose rate of 0.25 Mrad h[sup -1] in air at room temperature to a maximum dose of 500 Mrad. The linear coefficient of thermal expansion ([alpha]) was measured using a three-terminal capacitance technique reported previously. The variation of [alpha] with temperature between 10 K and 340 K was investigated for an unirradiated sample and two samples irradiated to 300 Mrad and 500 Mrad. In the range 10K to 160K, [alpha] is almost invariant with radiation dose and there is little difference between the values for the unirradiated and the 300 Mrad irradiated samples above 160 K. The sample irradiated to 500 Mrad does show a 6% increase in [alpha] over the other samples in the higher temperature range. All samples show an increase overall in the value of [alpha] with temperature. The melting point of each sample was also determined and was shown to decrease with radiation dose. (1 figure, 1 ...

International Nuclear Information System (INIS)

Full text.This paper describes a software tool for generation expansion planning based on dynamic programming, probabilistic production simulation, and environmental assessment. The aim is to determine the units needed to expand a given system in order to minimize either the cost or the environmental impact or some weighed function of the two. The problem of generation expansion planning is solved in stages using Tunnel Dynamic Programming (TDP) with Heuristic rules to limit the number of options analyzed. The production costing methodology is based on combining a probabilistic generation model known as the capacity outage table (COT) with the load duration curve (LDC) of the system to deduce a risk model from which the expected energy not supplied (EENS) is estimated. The generation model is built recursively using an efficient numerical convolution procedure and is combined at each step with the LDC to calculate the expected energy produced ...

Energy Technology Data Exchange (ETDEWEB)

This thesis consists of five chapters, each of which is a self-contained unit. The first chapter overviews methods for electronic-structure calculations. Chapter 2 introduces a new method to generate a rapidly converging configuration expansion. The approach iteratively combines (1) a least-squares fitting of a configuration expansion to a many-body wave function with (2) a transfer-matrix method for projecting out the ground state. Results are shown to be equivalent to multiconfiguration Hartree-Fock. Results from test calculations are given for a simple finite difference model of the helium atom. In Chapter 3 the use of the finite-element method in electronic structure calculations is discussed. Chapters 4 and 5 discuss developments in Monte Carlo methods based on Hubbard-Stratonovich transformations. Chapter 4 introduces a canonical ensemble formulation of the method, which is more appropriate than the usual grand canonical formulation for ...

Energy Technology Data Exchange (ETDEWEB)

The application of foam in dealing with underground fire is well known due to its smothering action by cutting off air feed to burning fuel as well as acting as coolant. Besides plugging air feed to fire, water could be virtually reached to the fire affected areas much beyond the jet range as underground galleries with low roof restrict jet range of water. This method also enables a closer approach of a fire fighting team by isolating the toxic gases and smoke with a foam plug. The paper describes the development of high expansion foam composition and its application technology in order that foam plug method can be suitably utilized for combating mine fires in India. Three compositions were recommended for generation of high expansion foam: (a) 0.5% sodium/ammonium lauryl sulphate, 0.15 to 0.2% sodium carboxy methyl cellulose, 0.1% booster; (b) 0.5% sodium/ammonium lauryl sulfate, 0.12 to 0.15% alkaline solution of gum arabic, 0.1 to 0.2% ...

Science.gov (United States)

Cross sections for excitation induced by electron collision between low-lying 1s{sup 2}2s{sup 2}2p{sup 5} and 1s{sup 2}2s2p{sup 6} states of f-like selenium and from these states to singly excited states with the excited electron occupying the M shell have been calculated by relativistic distorted-wave Born procedures. The GRASP{sup 2} code was used for the atomic structure calculations. The continuum orbitals for the construction of continuum states were computed in the distorted-wave approximation, in which the distorted-wave potential used was the spherically averaged potential of the nucleus plus the potential of the bound electrons of the bound state. The cross sections for excitations were computed first by a 233-level multiconfiguration Dirac-Fock (MCDF) configuration expansion and then by a 279-level MCDF configuration expansion. The latter procedure, which also took into account contributions from all the participating singly excited ...

Energy Technology Data Exchange (ETDEWEB)

The distribution of activation energies ..delta.. for classical over-the-barrier hopping is computed for a model amorphous metal. The spread in ..delta.. is determined by the variation in equilibrium-site and saddle-point sizes for the assumed model of dense random packing (DRP) of soft spheres. The size distribution is related to the radial distribution function in a manner which reproduces recent numerical results for the interstitials in DRP models. Size (distance) variation in general is related to energy variation by the form of the potential energy V(r). We show, however, that the distribution of equilibrium-site energies can be related directly to the impurity-induced lattice expansion and bulk modulus without detailed knowledge of V(r). The form of V(r) is necessary for the saddle-point distribution, and we estimate this using simple analytic expressions which fit the observed lattice expansion and impurity (hydrogen) vibrational ...

Energy Technology Data Exchange (ETDEWEB)

The accurate prediction of local hot spot during normal operation is important to ensure core thermal margin in a very high temperature gas-cooled reactor because of production of its high temperature output. The active cooling of the reactor core determining local hot spot is strongly affected by core bypass flows through the inter-column gaps between graphite blocks and the cross gaps between two stacked fuel blocks. The bypass gap sizes vary during core life cycle by the thermal expansion at the elevated temperature and the shrinkage/swelling by fast neutron irradiation. This study is to investigate the impacts of the variation of bypass gaps during core life cycle as well as core restraint mechanism on the amount of bypass flow and thus maximum fuel temperature. The core thermo fluid analysis is performed using the GAMMA+ code for the PMR200 block-core design. For the analysis not only are some modeling features, developed for solid conduction and bypass flow, ...

CERN Document Server

The discovery of an HI cloud with peculiar properties at equatorial coordinates (J2000) ra=07h49m, dec=04d30m is presented. The HI object was detected at 21cm using the 300-m NAIC Arecibo telescope. Subsequent follow-up high-resolution observations with the NRAO Very Large Array (VLA) telescope at L-Band revealed more details about its morphology. The most intriguing aspect of the object is the clear velocity gradient of 1 km/s, which is present in the data, an indication of either rotation or expansion. The gas appears to be cold, and its morphology is somewhat elliptical with clumpy substructure. Assuming disk rotation, the dynamical mass could be determined as a function of distance.Depending on the exact nature of the velocity gradient in the HI cloud, we can reach some preliminary conclusions about the nature of the object. Expansion would imply association with a circumstellar envelope of an evolved AGB star, while in the case of ...

Energy Technology Data Exchange (ETDEWEB)

The design of high level radioactive waste (HLW) repositories in deep geological media in which bentonite clay is proposed as a sealing material leads to the need of further studying the behaviour of highly compacted expansive soils when subjected to mechanical, hydraulic and thermal changes. Laboratory tests may help to understand the processes that take place in the clay barrier under simple and controlled conditions and to develop the governing equations. The laboratory tests enable to isolate the different processes, making their interpretation easier, and provide with fundamental data concerning the parameters to be used in the models. The extremely low permeability of these materials, their avidity for water (high suction) and their high swelling capacity make necessary the modification of the conventional laboratory techniques and procedures to determine basic physical parameters. The main hydraulic properties of the barrier to be considered are the ...

Energy Technology Data Exchange (ETDEWEB)

''Hair-on-end'' skull changes resembling thalassemia were rarely described in the 1950s and 1960s in children with cyanotic congenital heart diseases; these changes were described almost entirely in patients with tetralogy of Fallot or D-transposition of the great arteries. As these lesions have become correctable, the osseous changes, never common, seem now only to exist in a small number of patients with uncorrectable complex cyanotic congenital heart disease who survive in a chronic hypoxic state. We present two cases: a case of marked marrow expansion in the skull of a 5-year-old boy with uncorrectable cyanotic heart disease studied by CT, and a second case of an 8-year-old with tetralogy of Fallot and pulmonary atresia studied by plain skull radiographs. The true incidence of these findings is unknown. (orig.)

International Nuclear Information System (INIS)

In terms of Berezins's theory of symbols of operators, the integral formulation is suggested for the free differential algebra which gives rise to consistent equations of motion of interacting massless fields of all spins 0#<=#s<#infinity# in the frameworks of gravity. In the first nontrivial order of the expansion in powers of curvatures, Frobenius consistency conditions for higher-spin equations of motion are shown to reduce to the simple geometrical fast that there are two ways for splitting any quadrangle in two triangles. To clarify our construction, we illustrate how it works in the simplest case of pure gravity. (orig.).

International Nuclear Information System (INIS)

The problems associated with treating tachoyons in quantum field theory are discussed, and the quantization proposed by Arons and Sudarshan is chosen as the most satisfactory of the presently available methods, although it is unable to describe interactions in its present form. In order to help determine whether suitable S-matrices can ever be found, a perturbation-type expansion for the S-matrix is considered. It is shown that if the first order term is any polynomial in the tachyon field and its conjugate, then the reinterpreted, or physical, S-matrix will violate unitarity. An example shows that the inclusion of derivatives of the field is also expected to produce non-unitary physical S-matrices. The indications are that a correct interesting theory of tachyons must be non-local.

Energy Technology Data Exchange (ETDEWEB)

A prototype hydride storage bed, using LaNi{sub 4.25}Al{sub 0.75} as the storage material, was fitted with strain gages to measure strains occurring in the stainless steel bed vessel caused by expansion of the storage powder upon uptake of hydrogen. The strain remained low in the bed as hydrogen was added, up to a bed loading of about 0.5 hydrogen to metal atom ratio (H/M). The strain then increased with increasing hydrogen loading ({approximately} 0.8 H/M). Different locations exhibited greatly different levels of maximum strain. In no case was the design stress of the vessel exceeded.

CERN Document Server

It has been proposed that a hidden conformal field theory (CFT) governs the dynamics of low frequency scattering in a general Kerr black hole background. We further investigate this correspondence by mapping higher order corrections to the massless wave equations in a Kerr background to an expansion within the CFT in terms of higher dimension operators. This implies the presence of infinite towers of CFT primary operators with positive conformal dimensions compatible with unitarity. The exact Kerr background softly breaks the conformal symmetry and the scaling dimensions of these operators run with frequency. The scale-invariant fixed point is dual to a degenerate case of flat spacetime.

Energy Technology Data Exchange (ETDEWEB)

Relatively low molecular weights polyelectrolytes (10{sup 4}-10{sup 6}) behave as worm-like chain when electrostatic repulsions are assumed to govern the excluded volume parameter. Under such conditions, predictions of chain expansion and effect of polyelectrolyte concentrations are made assuming that unperturbed dimensions could be obtained at infinite salt content. Experimental studies of an ionic polysaccharide, namely the Na-hyaluronate, were done and the values obtained for the radius of gyration as well as the intrinsic viscosity at different charge densities are in good agreement with the predictions.

CERN Document Server

The phenomenon of time resonances (or explosions) can explain the exponential reduction of the energy, which is accompanied for the certain degree by slight fluctuations under some conditions in the range of the energy strongly overlapped compound-resonances. These resonant explosions correspond to formation of several highly-exited non-exponentially decaying nuclear clots (partial compound nuclei consisting of several small groups of projectile nucleons and targets). This paper is a continuation and expansion of theoretical authors' work, which is a more general self-consistent version of the time-evolution approach in comparison with the traditional Izumo-Araseki time compound-nucleus model.