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1

Seismic texture classification. Appendix 1. Generation of synthetic seismograms  

Energy Technology Data Exchange (ETDEWEB)

This note describe the generation of synthetic seismogram data using the seismod forward modelling tool. The seismic response from a well known subsurface is generated in order to verify a seismic interpretation tool based on statistical recognition of seismic reflection patterns. The model consist of a homogene subsurface with a target area. The target area is an arrangement of 2 dimensional plane layers supporting only acoustic waves. Each individual layer has a varying stratified structure obtained by alternations in the density of the material. The velocity of the seismic waves in the subsurface model is constant. The seismograms are obtained by measuring the reflections from a downward travelling plane wave impinging the target area. The reflections are measured in geophones placed along a horizontal straight line above the target area. (LN)

If, F.

1996-12-01

2

Wavelet transform and spectrum whitening of seismogram  

Energy Technology Data Exchange (ETDEWEB)

Based on the convolutional model of seismogram, the physical meanings of wavelet transform in seismogram are discussed. It is found that selecting suitably the wavelet function and scale factor, the wavelet transform for seismogram is corresponding to the spectrum of whitening of the seismogram. It is characterized by the higher resolution calculating speed, easy selection of parameters, and the best compromise between S/N and resolution for reflected waves coming from reflectors at different depths. The efficiency of the method has been proven by modelling and case calculating result. 7 refs. 5 figs.

Gao, J.; Zhu, G.; Wang, W.; Yuan, C.; Wang, Y.; Ju, X. [Xian Jiaotong University (China)

1997-11-01

3

Generation of nonclassical microwave states using an artificial atom in 1D open space.  

UK PubMed Central (United Kingdom)

We have embedded an artificial atom, a superconducting transmon qubit, in a 1D open space and investigated the scattering properties of an incident microwave coherent state. By studying the statistics of the reflected and transmitted fields, we demonstrate that the scattered states can be nonclassical. In particular, by measuring the second-order correlation function, g((2)), we show photon antibunching in the reflected field and superbunching in the transmitted field. We also compare the elastically and inelastically scattered fields using both phase-sensitive and phase-insensitive measurements.

Hoi IC; Palomaki T; Lindkvist J; Johansson G; Delsing P; Wilson CM

2012-06-01

4

Generation of nonclassical microwave states using an artificial atom in 1D open space  

CERN Multimedia

We have embedded an artificial atom, a superconducting transmon qubit, in a 1D open space and investigated the scattering properties of an incident microwave coherent state. By studying the statistics of the reflected and transmitted fields, we demonstrate that the scattered states can be nonclassical. In particular, by measuring the second-order correlation function, $g^{(2)}$, we show photon antibunching in the reflected field and superbunching in the transmitted field. We also compare the elastically and inelastically scattered fields using both phase-sensitive and phase-insensitive measurements.

Hoi, Io-Chun; Johansson, Göran; Lindkvist, Joel; Delsing, Per; Wilson, C M

2012-01-01

5

Synthetic seismograms - II. Synthesis of amplitude spectra and seismograms of P waves from underground nuclear explosions  

International Nuclear Information System (INIS)

As a part of programme of seismic detection of underground nuclear explosions, step by step variations in the amplitude spectra and waveforms of P wave signal, as it propagates from source to receiver region, are investigated. Influences on the amplitude spectra and waveforms of teleseismic p waves due to : (1) variation in the shape of reduced displacement potential, (2) variation of mantle Q values, (3) change in depth, (4) various yields, (5) spalling, and (6) variation of crustal structure at source as well as at receiver are studied. The results show that for a yield of 85 kilotons, the time structure of seismograms is nearly same for four types of reduced displacement potentials considered here. The duration of waveforms is affected both by crustal structure at source as well as due to spalling. In general, effect of receiver crust on seismograms is found to be minor. Synthesized and observed P wave seismograms for Longshot, Milrow and Cannikin underground nuclear explosions are computed at various seismometer array stations of the UKAEA. Computed seismograms compare well with the recorded ones. It is seen that: (1) overburden P wave velocity inferred from seismograms is less as compared to its value obtained from on-site measurements, and (2) the source function, the source crust transfer function, the mantle transfer function and the spalling function are the most important factors that influence shaping of spectra and seismograms. (M.G.B.).

1980-01-01

6

Seismogram Construction to Fit the Recorded B032593c Earthquake, Japan on Observation Station Bfo, Germany  

Directory of Open Access Journals (Sweden)

Full Text Available In this research the model of earth layers between earthquake's epicenter in Hokkaido Japan and observation station in Black Forest of Observatory (BFO), Germany is investigated. The earth model is 1-D that represents the average speed model. The earth model is obtained by seismogram comparison between data and synthetic seismogram in time domain and three components simultaneously. Synthetic Seismogram is calculated with the Green's function of the Earth by MINor Integration (GEMINI) program, where program's input is initially the earth model IASPEI91, PREMAN and also the Centroid Moment Tensor (CMT) solution of the earthquake. A Butterworth low-pass filter with corner frequency of 20 mHz is imposed to measured and synthetic seismogram. On seismogram comparison we can find unsystematic discrepancies, covering the travel time and waveform of all wave phases, namely on P, S, SS wave and surface wave of Rayleigh and Love. Solution to the above mentioned discrepancies needs correction to the earth structure, that covering the change of earth crust thickness, the gradient of ?h and value of zero order coefficient in ?h and ?v in upper mantle, to get the fitting on the surface wave of Love and Rayleigh. Further correction to accomplish the discrepancies on body waves is conducted on layers beneath upper mantle down to depth of 630 km, where a little change at speed model of P and S wave is carried out. The number of oscillation amount especially on Love wave is influenced by earth crust depth earth. Good fitting is obtained at phase and amplitude of Love wave, but also at amplitude of some body wave too. This effect is not yet been exploited for the determination of moment tensor.

Bagus Jaya Santosa

2005-01-01

7

Methods of finding a duplex-wave on seismograms OGT  

Energy Technology Data Exchange (ETDEWEB)

Studies were made of the features of the travel time curve of the duplex-waves on seismograms arranged over a common deep point of single-reflected seismic waves. The need is theoretically substantiated for input into the seismograms of the OGT of linear-changing corrections to obtain the optimal summation of the duplex-wave signals.

Uzhakin, B.A.

1982-01-01

8

Iodine-doped-poly(3,4-ethylenedioxythiophene)-modified Si nanowire 1D core-shell arrays as an efficient photocatalyst for solar hydrogen generation.  

UK PubMed Central (United Kingdom)

A new 1D core-shell strategy is demonstrated for a hydrogen-generation photo-electrochemical cell (PEC). This Si/iodine-doped poly(3,4-ethylenedioxythiophene) (PEDOT) 1D nanocable array shows an encouraging solar-to-chemical energy-conversion efficiency. Coating with iodine-doped PEDOT can effectively enhance the photocatalytic efficiency and stability of SiNW arrays. The PEC model proposed shows a potentially promising structure for H(2) production using solar energy.

Yang T; Wang H; Ou XM; Lee CS; Zhang XH

2012-12-01

9

Effects of spall on regional seismograms  

Energy Technology Data Exchange (ETDEWEB)

The effects of spall on regional signals are investigated using synthetic seismograms to frequencies of 20 Hz. Depending on the scaling relationships used, it is found that spall may have an important effect on regional body waves and especially surface waves. The frequency range in which the spall effect dominates is dependent upon the characteristic times of the spallation process, but generally occurs in the frequency range of about 0.2 to 2 Hz. Because of the peaked nature of the radiated spall spectra, effects at frequencies outside the 0.2 to 2 Hz frequency range will be dominated by the explosion source. The frequency range and strength of the spall effect depend in a complicated manner upon the yield, depth of burial, near-source structure, and material strength. Uncertainties in the spall scaling relationships need to be better understood before the effects of spall on regional discrimination and yield estimation can be properly quantified. copyright American Geophysical Union 1989

Taylor, S.R.; Randall, G.E.

1989-02-01

10

Studies conducted at the U-25 Facility (IV). Experimental studies of the MHD generator of the U-25 Facility with the 1D channel  

International Nuclear Information System (INIS)

This report is dedicated to the testing and shakedown of the 1D channel developed in order to obtain the rated power (20 MW) from the MHD generator of the U-25 Facility. When the designing of the channel was begun, the U-25 Facility had achieved certain positive results and accumulated a great deal of experience in the operating of the loop and the MHD generator. This experience was taken into account during the designing and the shakedown of the 1D channel. The power output of the MHD generator in 1974 had reached 6.5 MW. The shakedown period of the facility has entered its concluding phase. One of the main purposes of this phase was to achieve the rated power in the MHD generator. During the initial tests of the 1D channel at reduced flow rates (50 kg/s), the power output of the MHD generator reached 12.4 MW. The transition to the nominal operating mode required undertaking certain measures to perfect the insulation, the loading scheme, etc. The final adjustment of the 1D channel made it possible to attain during the 58th run of the U-25 Facility the rated power of the MHD generator-20.1 MW. Channel 1D has been designed in the Experimental Design Bureau and built at the experimental facilities of the Experimental Design Bureau of the Institute for High Temperatures. The present report contains a brief description of the main principles upon which the design of the 1D channel was based and of the results obtained during the experimental study of this channel at the U-25 Facility

11

Studies Conducted at the U-25 Facility (Iv). Experimental Studies of the Mhd Generator of the U-25 Facility with the 1D Channel.  

Science.gov (United States)

This report is dedicated to the testing and shakedown of the 1D channel developed in order to obtain the rated power (20 MW) from the MHD generator of the U-25 Facility. When the designing of the channel was begun, the U-25 Facility had achieved certain p...

B. Y. Shumiatskii A. E. Buznikov I. A. Vasil'eva V. V. Kirillov V. I. Kovbasiuk

1976-01-01

12

Studies on the resistance of ground and structure against earthquake. ; Simulation analysis of seismograms recorded at no. 2 generator of the Tomato Atsuma power plant. Preliminary report. Jiban oyobi kozobutsu no taishinsei ni kansuru kenkyu. ; Tomato Atsuma hatsudensho dai-2-goki no jishin kiroku simulation kaiseki ni tsuite. Chukan hokoku  

Energy Technology Data Exchange (ETDEWEB)

The building constructed for a generator {prime} s boiler at the Atsuma power plant, Japan, is a big structure rising to a height of over 70 m above the surface of weak ground. A Fourier analysis was performed of the seismograms recorded at nine points of the building and grownd on the occasion of the earthquake that occurred at a location 144 km distant from the plant in Jannuary 1987, its scale of magnitude being 7.0. The features of the motion that took place at the ground, building and boiler in response to this earthquake were repre-sented mainly by means oftransfer functions, their respective dominant frequencies being indicated. A system of elastically linked particles was used as the model of the building and ground in order to simulate their motion. Calculations were carried out to obtain response of the model to the input of the earthquake motion observed at the depth of 47 m below the ground surface, the attenuation constants assumed for each parts of the model being adjusted with the progress of simulation. The features of motion obtained by the calculat-ions correspond for the most part to those of the record except the boiler which showed somewhat complex response. 3 refs., 18 figs., 7 tabs.

Shioya, T. (The Hokkaido Electric Power Co. Inc., Sapporo (Japan))

1990-03-20

13

Simultaneous collinear and non-collinear parametric generation in 1D single grating periodically poled lithium tantalate  

Science.gov (United States)

We report a detailed study of multiple wavelengths optical parametric generation in a single grating one-dimensional periodically poled lithium tantalate crystal. Simultaneous collinear and non-collinear generations are observed around the pump collinear direction. Similar spectra are found in continuous spatial positions symmetrical to the collinear direction, with decreasing signal and increasing idler wavelengths, associated with decreasing powers when the far-field angle increases. A phase matching scheme is proposed to describe these interactions. Numerical simulations emphasize the agreement of our phase matching scheme with the experimental results. Single-pass gain and high pump power density are very likely at the origin of the simultaneous collinear and non-collinear QPM interactions.

Lazoul, Mohamed; Boudrioua, Azzedine; Simohamed, Lotfy Mokhtar; Fischer, Alexis; Peng, Lung Han

2013-03-01

14

Solution to the 1-D unsteady heat conduction equation with internal Joule heat generation for thermoelectric devices  

International Nuclear Information System (INIS)

Thermoelectric devices are semiconductor devices which are capable of either generating a voltage when placed in between a temperature gradient, exploiting the Seebeck effect, or producing a temperature gradient when powered by electricity, exploiting the Peltier effect. The devices are usually employed in environments with time-varying temperature differences and input/output powers. Therefore it becomes important to understand the behaviour of thermoelectric devices during thermal and electrical transients in order to properly simulate and design complex thermoelectric systems which also include power electronics and control systems. The purpose of this paper is to provide the transient solution to the one-dimensional heat conduction equation with internal heat generation that describes the transfer and generation of heat throughout a thermoelectric device. The solution proposed can be included in a model in which the Peltier effect, the thermal masses and the electrical behaviour of the system are considered too; this would be of great benefit because it would allow accurate simulations of thermoelectric systems. While the previous literature does not focus on the study of thermal transients in thermoelectric applications and usually considers constant the temperatures at the hot and cold sides, this paper proposes a dynamic exchange of heat through the hot and cold side, both in steady-state and transients. This paper also presents an analytical solution which is then computed by Matlab to simulate a physical experiment. Simulation results show excellent correlation with experimentally determined values, thus validating the solution. - Highlights: ? We solve the one-dimensional heat conduction equation for thermoelectric devices. ? Both the steady-state and transient solutions are provided. ? This solution can be used to accurately simulate thermoelectric systems. ? Simulations and experimental results are provided.

2012-01-01

15

Evidence for S(1D) atom reactions involving 34S(n,?)35S nuclear recoil generated sulfur  

International Nuclear Information System (INIS)

The recoil sulfur species were generated by thermal neutron irradiation of CS2. The effect of various gas additives on the total production of CS35S from nonlabeled CS2 was determined in order to investigate the role of various forms of recoil atom excitation in driving the exchange reaction. The efficiency of the sulfur atom exchange reaction rose linearly within experimental error as the mole fraction of CS2 increased. The most reasonable reaction mechanism said to account for the major features of the data is based on excited singlet sulfur atom exchange reactions with CS2 in competition with quenching. (U.S.)

1975-08-20

16

Role of synthetic seismograms in exploration for upper Ismay algal mounds, Paradox basin  

Energy Technology Data Exchange (ETDEWEB)

Synthetic seismograms have traditionally been used primarily to tie in a particular geologic top to a seismic section. If applied solely in this manner the synthetic is underutilized, especially in basins where seismic stratigraphy is used extensively. In fact, with a little ingenuity, synthetic seismograms can give an interpreter insight into which seismic picks are consistent and suitable for mapping, the geologic significance of amplitude variations, and how to estimate reservoir quality and thickness from seismic sections. The key to this approach is to generate as many synthetics as possible, making them as consistent as possible, and then, integrating the geologic information, to analyze them as a package. A synthetic study was undertaken in the Ismay fairway of the Paradox basin, southeastern Utah. Synthetics were generated for both producers and dry holes and were analyzed, as a group, for consistency of the geologic picks. The upper Ismay, lower Ismay, and Desert Creek pickes were the most consistent, while the intervening Hovenweep and Gothic shales were the least consistent. Isochrons, based on consistent picks, were calculated from the synthetics and plotted against the corresponding isopach. Results indicate that a linear relationship exists, allowing for conversion of seismic data to isopach. Error analysis can quantify the significant contour interval. By highlighting producing wells from dry holes, it is apparent that there is a critical isochron value needed for production. Further analysis indicates that amplitude can be used in estimating reservoir quality and that it is possible to estimate carbonate thickness from the isochron.

McCutcheon, J.A.

1989-03-01

17

S-Wave Velocity Structure beneath Southwest North America from Seismogram Comparisons of the Mexico Earthquake on 22 June 1997  

Directory of Open Access Journals (Sweden)

Full Text Available This research investigates earth structure beneath the Southwest North America landmass, especially between Mexico and California. Models based on S wave velocities for this area were obtained by carrying out seismogram fitting in time domain and three Cartesian components simultaneously. The data used is from an event, coded as C052297B that occurred in the state of Guerrero, Mexico and it was fitted to synthetic data computed with the GEMINI program at TS network stations. Earth model IASPEI91 and SPREM were used as input to create the synthetic data. Real and synthetic seismograms were subjected to a low-pass filter with a frequency corner of 20 mHz.Waveform analysis results show very unsystematic and strong deviations in the waveform, arrival times, amount of oscillation and the height of the wave amplitude. Discrepancies are met on S, Love, Rayleigh and ScS waves, where the stations epicentral distances are below 300. Deviation in analysis waveform because of the usage of model 1-D of SPREM and IASPEI91, because the 1-D was a kind of average value an elastic property at one particular depth of global earth. With the method of waveform analysis we can see how sensitive waveform is to structures within the layers of the Earth.To explain the discrepancies, a correction to the earth structure is essential. The corrections account for the thickness of the crust, speed gradient of bh, the coefficient for the bh and bv in the upper mantle for surface wave fitting, a small variation of the S speed structure at a layer under the upper mantle above 771 km for S wave fitting, and a small variation at the base the mantle layers for ScS wave fitting. At some stations, a correction for S speed structure have yielded P wave fitting. Results of this research indicate that the 1-D earth model obtained through seismogram fitting at every hypocenter-observation station pair is unique. The S-wave velocity on the upper mantle has strong negative anomalies. This paper criticized the previous earth models in the same area, which have been published by other seismologists, by analyzing the seismogram of C052297B earthquake in the TS seismological network station

Bagus Jaya Santosa

2008-01-01

18

Simulation of seismograms in a 2-D viscoelastic Earth by pseudospectral methods  

Directory of Open Access Journals (Sweden)

Full Text Available Using an improved global pseudospectral modeling algorithm we synthesize seismograms generated by oceanic and continental earthquakes. Attention is given to attenuation, to explicit modeling of boundary conditions at the ocean-bottom interface, simulation of the Rayleigh window and interface-wave propagation. The algorithm is based on Fourier and Chebyshev differential operators and a domain-decomposition technique - one grid for the fluid and another grid for the solid. Wave propagation in the oceanic and continent crusts and mantle is modeled by using a viscoelastic stress-strain relation based on memory variables.The main physical phenomena associated with an ocean-crust system are modeled, including Scholte waves, leaking Rayleigh waves, dispersive modes, and the Rayleigh-window phenomenon due to a minimum in the reflection coefficient of the ocean bottom, which has not been simulated with direct methods. In particular, we model Rayleigh modes (mainly the M11 mode), and coupled Rayleigh-Scholte waves, for which the dispersion relation is solved in simple cases. Also, we model the effects of random inhomogeneities in the crust and mantle by using a von Kármán autocovariance probability function, which simulates scattering-Q-effects.The 2-D modeling code allows general material variability, and a complete and accurate characterization of the seismic response of oceanic and continental earthquakes. A synthetic seismogram for an earthquake in the South Atlantic region is provided.

José M. Carcione; Hans B. Helle; Géza Seriani; Milton P. Plasencia Linares

2005-01-01

19

The effects of major structural features in Western China on explosion seismograms  

Energy Technology Data Exchange (ETDEWEB)

Synthetic explosion seismograms have been calculated on paths from Lop Nor to the NIL station in northern Pakistan, from NIL to Lop Nor, and from Lop Nor to the TLY station in the Baikal Rift. Computational studies were done of the influence on the character of the seismograms of major structural features such as sedimentary basins, topography associated with the Himalayas and the Tibetan Plateau, roughness of the Moho, and the presence of a deep Moho depression under the Tibetan Plateau, roughness of the Moho, and the presence of a deep Moho done with a 1-Hz Kelly waves source and 500-m resolution. Uniform elastic constants and frequency-independent quality factors, Q{sub p} and Q{sub s}, were used in each of three materials: basin sediments, crust, and mantle. The deep basins which due to the generation of large-amplitude Rayleigh waves at source-ward basin edges. In simulations done with the effects of anelastic attenuation included, the amplitude of passage across the 800-km-wide Tarim Basin on the Lop Nor -> NIL path but not on the 200-km path across the basin that straddles the Lop Nor -> TLY path.

Jones, E.M.; App, F.N.; Bos, R.J.

1997-11-01

20

The correct Q1D electrodynamical part of a model for the fluid flow in a faraday segmented magnetohydrodynamic generator channel  

International Nuclear Information System (INIS)

A Faraday ideally segmented (the absence of the Hall electric current Ix=0) MHD generator channel, with a weakly ionized plasma as a working fluid, is considered. The magnetic field is applied along the z axis and the working fluid flows along the x axis. The stationary state of the flow and the stationary electric current are considered. The new quasi-one-dimensional (Q1D) electrodynamical part of a model is developed. The main assumption (besides jz = 0, Ez = 0) taken in the whole working fluid flow, is jx = 0. It means that the bending of the electric current pattern in the working fluid, due to the nonmassive electrodes and the presence of the magnetic field, is not explicitly considered. In the frame of the assumption taken, the legitimacy regarding the equation of conservation of charges: div rvec j = 0 suggests that the straight electric current pattern in the model should be narrow. In other words, it suggests replacing of a rather complicated electric current pattern in a working fluid by an artificially straight and narrow one in the modeling, promising that it would still be possible to describe the global channel parameters - its electrical output, the influence of the shape and the size of the channel on the generator performance etc.

1995-08-04

 
 
 
 
21

Fast estimation of local magnitudes from non-standard Wood-Anderson, short period, seismograms  

Directory of Open Access Journals (Sweden)

Full Text Available We propose a method for fast estimation of local magnitudes from seismograms (analog or digital) different from the standard Wood-Anderson ones. The method provides a justification of the widely used methods for approximate evaluation of magnitudes from analog seismograms. The method is illustrated through an application to local microseismic data from Baja California, Mexico.

F. A.Nava; R. García-Arthur; J. Frez; J. Acosta; J. Carlos; J. J. González

2003-01-01

22

A kinetic study on singlet molecular oxygen (O{sub 2}({sup 1d}elta{sup g})) generation and quenching by dihydroxynapthalenes  

Energy Technology Data Exchange (ETDEWEB)

Anaerobic photo-oxidation of a series of dihydroxynapthalenes (DHN)was studied.It was found that the interaction of O{sub 2}({sup 1d}elta{sup {sub g}}) yielded a quenching rate constant, the range depending on solvent polarity, pH, and substitution pattern of the DHN. The mechanism of the interaction appeared to be mediated by an encounter complex with a considerable charge transfer component, similar to the photo-oxidative kinetic behavior of simple substituted phenols and dihydroxybenzenes. DHN were found to be highly reactive towards O{sub 2}({sup 1d}elta{sup {sub g}}) when the hydroxy groups are ionized. Various tests indicated that DHN are good candidates for an environmental O{sub 2}({sup 1d}elta{sub g})-mediated photo-oxidation. 27 refs., graphs.

Luiz, M. [Universidad Nacional de La Patagonia, San Juan Bosco (Argentina); Soltermann, A. T.; Biasutti, A.; Garcia, N. A. [Universidad Nacional de Rio Cuarto, Rio Cuarto (Argentina)

1996-01-01

23

Generation of a pseudo-2D shear-wave velocity section by inversion of a series of 1D dispersion curves  

Science.gov (United States)

Multichannel Analysis of Surface Waves utilizes a multichannel recording system to estimate near-surface shear (S)-wave velocities from high-frequency Rayleigh waves. A pseudo-2D S-wave velocity (vS) section is constructed by aligning 1D models at the midpoint of each receiver spread and using a spatial interpolation scheme. The horizontal resolution of the section is therefore most influenced by the receiver spread length and the source interval. The receiver spread length sets the theoretical lower limit and any vS structure with its lateral dimension smaller than this length will not be properly resolved in the final vS section. A source interval smaller than the spread length will not improve the horizontal resolution because spatial smearing has already been introduced by the receiver spread. In this paper, we first analyze the horizontal resolution of a pair of synthetic traces. Resolution analysis shows that (1) a pair of traces with a smaller receiver spacing achieves higher horizontal resolution of inverted S-wave velocities but results in a larger relative error; (2) the relative error of the phase velocity at a high frequency is smaller than at a low frequency; and (3) a relative error of the inverted S-wave velocity is affected by the signal-to-noise ratio of data. These results provide us with a guideline to balance the trade-off between receiver spacing (horizontal resolution) and accuracy of the inverted S-wave velocity. We then present a scheme to generate a pseudo-2D S-wave velocity section with high horizontal resolution using multichannel records by inverting high-frequency surface-wave dispersion curves calculated through cross-correlation combined with a phase-shift scanning method. This method chooses only a pair of consecutive traces within a shot gather to calculate a dispersion curve. We finally invert surface-wave dispersion curves of synthetic and real-world data. Inversion results of both synthetic and real-world data demonstrate that inverting high-frequency surface-wave dispersion curves - by a pair of traces through cross-correlation with phase-shift scanning method and with the damped least-square method and the singular-value decomposition technique - can feasibly achieve a reliable pseudo-2D S-wave velocity section with relatively high horizontal resolution. ?? 2008 Elsevier B.V. All rights reserved.

Luo, Y.; Xia, J.; Liu, J.; Xu, Y.; Liu, Q.

2008-01-01

24

Seismograms of explosions at Regional Distances in the Western U. S. : observations and reflectivity method modeling  

Energy Technology Data Exchange (ETDEWEB)

Seismic energy propagating through vertically and laterally varying structures of the earth's crust and lower lithosphere-uppermost mantle is responsible for the numerous and complex seismic phases observed on short-period seismograms at regional distance ranges (100 to 2000 km). Recent advances in techniques for computing synthetic seismograms make it practical to calculate complete seismograms that realistically model many features of regional phases. A modified reflectivity method program is used to interpret some details of record sections of Nevada Test Site (NTS) underground explosions that were observed 700 to 800 km from the sources.

Olsen, K.H.; Braile, L.W.

1980-01-01

25

Advanced criteria of seismic zoning and synthetic seismograms  

International Nuclear Information System (INIS)

A brief revision of the traditional deterministic and probabilistic methods of first order seismic zonation, outlining their limits and possibilities, indicates that they can only lead to a kind of ''post-event'' zonation, which has a limited local validity. The strong influence of laterial heterogeneities and of source properties on the spatial distribution of Peak Ground Acceleration (PGA) and of the Total Energy of ground motion (W), indicates that the traditional methods require a deep revision. The method we have developed and applied to a first-order seismic zoning of the whole Italian territory and to the microzoning of specific objects, being based on the computation of synthetic seismograms, makes it possible and necessary to take source and propagation effects into account, fully utilizing the large amount of geological and geotechnical data, already available. Even though it falls in the domain of deterministic approaches, the method is very suitable for inclusion in the definition of new integrated procedures which combine probabilistic and deterministic approaches and allow us to minimize the present drawbacks which characterise the two methods when they are considered separately. If the seismotectonic regime is well known, a very important practical aspect of our deterministic approach is the immediate capability to direct the rescue intervention of the Civil Defence where the greatest damage is expected, by drawing post-event synthetic isoseismals for the source regions. Detailed modelling of ground motion for realistic two-dimensional media is a low-cost but very powerful tool for the prevention aspects of Civil Defence since it allows the computation of realistic seismic input for important structures based on the definition of a wide set of possible scenarios, which can be immediately used in the design of new seismo-resistant constructions and in the reinforcement of existing structures. (author). 65 refs, 14 figs

1993-01-01

26

Predicting interval transit time for synthetic seismograms from nuclear well logs  

Energy Technology Data Exchange (ETDEWEB)

Sonic logs commonly were not included as part of the logging program on older wells. In certain areas, wells are drilled with air. The absence of drilling fluid in the borehole eliminates the possibility of recording a sonic log. In other areas, sonic logs are either of poor quality or, for one reason or another, omitted from the logging program. A method has been developed to predict interval transit times using nuclear well logs. It involves combined neutron, density, and gamma-ray log measurements into a log of predicted interval transit times referred to as a synthetic sonic log. The method involves a combination of commonly used and accepted well-log interpretation techniques. It effectively accounts for lithology, shale, porosity and hydrocarbon effects. The method requires only 3 parameters, which may be selected based on the well-log data. The synthetic sonic log agrees well with actual sonic-log measurements over a wide variety of geographic areas and borehole depths. The method is effective for formations commonly encountered in geophysical well logging including salt, shale, sandstone, and carbonate. The synthetic sonic log is an excellent substitute for use in generating synthetic seismograms and establishing time-depth relationships.

Corley, B.H.

1985-02-01

27

Ray synthetic seismograms: a useful tool in the International Data Center environment  

Directory of Open Access Journals (Sweden)

Full Text Available In this paper some of the results of a feasibility study on ray synthetic seismograms usage are reported. A computational method, ways of composing synthetic traces, an application of the source wavelet and the radiation pattern and integration of such an approach into the Center for Seismic Studies (CSS) revision 3.0 structure are outlined. Further on, results obtained for model examples, nuclear explosions, and earthquakes are presented. Conclusions of the undertaken feasibility study help to understand that ray synthetic seismograms represent a very fast tool (results in ?no time?) and simultaneously represent a complex tool with all needed features. The ray synthetic seismograms can be implemented in various ways: to be computed automatically and used within the Intelligent Monitoring System, to be computed automatically and provided to the analyst, to provide a database of master events, to be computed interactively by an analyst during routine daily analysis.

P. Firbas

1994-01-01

28

YASEIS: Yet Another computer program to calculate synthetic SEISmograms for a spherically multi-layered Earth model  

Science.gov (United States)

Although most researches focus on the lateral heterogeneity of 3D Earth nowadays, a spherically multi-layered model where the parameters depend only on depth still represents a good first order approximation of real Earth. Such 1D models could be used as starting models for seismic tomographic inversion or as background model where the source mechanisms are inverted. The problem of wave propagation in a spherically layered model had been solved theoretically long time ago (Takeuchi and Saito, 1972). The existing computer programs such as Mineos (developed by G. Master, J. Woodhouse and F. Gilbert), Gemini (Friederich and Dalkolmo 1995), DSM (Kawai et. al. 2006) and QSSP (Wang 1999) tackled the computational aspects of the problem. A new simple and fast program for computing the Green's function of a stack of spherical dissipative layers is presented here. The analytical solutions within each homogeneous spherical layer are joined through the continuous boundary conditions and propagated from the center of model up to the level of source depth. Another solution is built by propagating downwardly from the free surface of model to the source level. The final solution is then constructed in frequency domain from the previous two solutions to satisfy the discontinuities of displacements and stresses at the source level which are required by the focal mechanism. The numerical instability in the propagator approach is solved by complementing the matrix propagating with an orthonormalization procedure (Wang 1999). Another unstable difficulty due to the high attenuation in the upper mantle low velocity zone is overcome by switching the bases of solutions from the spherical Bessel functions to the spherical Hankel functions when necessary. We compared the synthetic seismograms obtained from the new program YASEIS with those computed by Gemini and QSSP. In the range of near distances, the synthetics by a reflectivity code for the horizontally layers are also compared with those from YASEIS. Finally the static displacements in the source region are computed by choosing a very small frequency value in YASEIS which is designed for computing the dynamic response, and compared with the results in a homogeneous half-space model (Okada 1992). [1] Friederich, W. and J. Dalkolmo (1995). Complete synthetic seismograms for a spherically symmetric Earth a numerical computation of the Green's function in the frequency domain, Geophys. J. Int., vol. 122, 537-550. [2] Kawai, K., N. Takeuchi, and R.J. Geller (2006). Complete synthetic seismograms up to 2Hz for transversely isotropic spherically symmetric media, Geophys. J. Int., vol. 164, 411-424. [3] Okada, Y. (1992). Internal deformation due to shear and tensile faults in a half space, Bull. Seismol. Soc. Am., vol. 82, no. 2, 1018-1040. [4] Takeuchi, H. and M. Saito (1972). Seismic surface waves, Methods in computational physics, vol. II, 217-295. [5] Wang, R. (1999). A simple orthonormalization method for stable and efficient computation of Green's functions, Bull. Seismol. Soc. Am., vol. 89, no. 3, 733-741.

Ma, Yanlu

2013-04-01

29

Seismogram Analysis of Earthquakes Around Indonesia In UGM Observational Station: S Velocity Structure.  

Directory of Open Access Journals (Sweden)

Full Text Available The seismogram comparison between the measured and synthetics seismogram has been carried out in observation station of UGM, where the seismograms are excited by earthquakes that occurred at North Sumatra, Sumbawa, Sunda Strait, around North Celebes and PNG. The ray paths from earthquake's hypocenter to UGM give opportunity to understand the earth structure alongside the front area of subduction zone. The calculation of synthetic seismogram needs input in the form of earth model, the Centroid Moment Tensor (CMT) solution of the earthquake and location of observation station, as well as the relevant date file response of the observation station. Waveform comparison and fitting at surface wave indicate that speed's anomalies in the lithosphere have negative character in front area of subducted zone, but become positive for northern area of subduction zone. By paying attention to waveform of Love surface wave, it is obtained, that this waveform are sensitive to the change of earth crust thickness, while Rayleigh waveform is not sensitive. Heterogeneity is not only occurred in the lithosphere, but also in deeper earth layers, until Core Mantle Boundary (CMB). Different corrections are needed to make the fitting at S secondary wave, but also at depth wave and its repetitions. The result of this research shows that the research area, which is located in the front of subduction zone has anomalies at S speed of at deeper earth layers which than the lithosphere. The earth structure as the result of this research differs from the other seismological results, where they used the methods, which are based on inversion of arrival time data of body wave and dispersion analysis on surface wave.

Bagus Jaya Santosa

2008-01-01

30

Information passage from acoustic impedance to seismogram: Perspectives from wavelet-based multiscale analysis  

Science.gov (United States)

Traditional seismic interpretation of surface seismic data is focused primarily on seismic oscillation. Rich singularity information carried by, but deeply buried in, seismic data is often ignored. We show that wavelet-based singularity analysis reveals generic singularity information conducted from acoustic impedance to seismogram. The singularity exponents (known as Hölder exponent ?) calculated from seismic data are independent of amplitude and robust to phase changes and noises. These unique properties of ? offer potentially important application in many fields, especially in studying seismic data interpretation, processing, inversion, and wave attenuation.

Li, Chun-Feng

2004-07-01

31

Computation of SH synthetic seismograms along horizontal and vertical profiles by the Alekseev-Mikhailenko method  

Energy Technology Data Exchange (ETDEWEB)

The computation of SH synthetic seismograms for an isotropic vertically inhomogeneous medium using a technique originally developed by Alekseev and Mikhailenko is presented. An explicit finite-difference solution for the elastodynamic wave equation describing the propagation of SH-waves is determined after the dimensionality of the wave equation equation is reduced through the use of a finite Hankel transform. Formulae are presented in a form suitable for direct computer application. To facilitate the development of such a computer code, the finite-difference integral-transform method is briefly reviewed and a stability criterion is determined. In addition, some practical guidelines, based on experience with computer programs employing the Alekseev-Mikhailenko method (AMM), are presented. This is done in order to enhance the tutorial value of the paper which should be considered as an introduction to the AMM numerical technique, as it is becoming increasingly popular among practicing seismologists due to the availability of continuing advances in computer power. In this paper an SH point torque source and a horizontal point force, both located at the surface, are used for the computation of synthetic seismograms. The numerical models presented illustrate the nature of wave propagation for a model containing two thin low-velocity layers in a homogenous half-space. Both horizontal traces vertical seismic profile are computed for the model, and the applicability of the method, when compared to other alternative seismic modelling techniques, is examined. 15 refs., 7 figs., 1 tab.

Pascoe, L.J.; Hron, F.; Dailey, P.F.

1988-06-01

32

Terahertz Signal Generation in 1-D Photonic Crystals Terahertz Signal Generation in 1-D Photonic Crystals  

Directory of Open Access Journals (Sweden)

Full Text Available Theoretical and numerical results are presented to assure that a tunable, narrow-band, coherent THz radiation source can be based on parametric down-conversion in aphotonic crystal. Our proposal is based on down-conversion mixing and a local-field enhancement mechanism that is available by tuning each of the two driving laserfields either to band-edge or to a defect mode in the band gap. The frequency of the down-converted signal can be tuned by intersecting two non co-linear laser sources. The polarizations are degenerate at normal incidence and have sub-THz down-conversion maximum. For aspecific sample geometry we show that by changing the angle of incidence of one tunable laser to 30 degrees the THz frequency is about11.5 THz for p-polarization and 3.5THz for s-polarization, since the angle-dependent transmission spectrum is different for p- and spolarizations.The peak conversion efficiency for both polarizations is enhanced by over two orders of magnitude. Finally we also introduce some preliminary experimental results which agree with the numerical results we present here.En este trabajo presentamos resultados teóricos y numéricos que aseguran poder obtener una fuente de radiación coherente, sintonizable y de banda angosta en la región terahertzdel espectro electromagnético. Nuestra propuesta se basa en el efecto de conversión paramétrica no lineal y en el mecanismo de amplificación delcampo. Estos efectos se obtienen simultáneamente al sintonizar dos fuentes láser en la orilla de la banda prohibida o en el modo de un defecto localizado del cristal fotónico. La frecuencia de la señal obtenida puede ser sintonizada al mezclar las dos fuentes láser con diferente ángulo de incidencia. Las polarizaciones son degeneradas a un ángulo de incidencia normal y la conversión paramétrica genera señales sub-terahertz. Para una muestra específica, mostramos que cambiando el ángulo de incidencia de un láser sintonizable a 30 grados,la frecuencia de la señal obtenida en el cristal es de 11.5 THz para la polarización p y de 3.5 THz para la polarización s. Esto es debido a que el espectro de transmisión es dependientedel ángulo y por lo tanto, existen diferencias para la polarización p y para la s. La eficiencia de conversión pico para ambas polarizaciones es amplificada por más de dos órdenes de magnitud. Finalmente, también se muestran algunos resultados experimentales preliminares que concuerdan con los resultados numéricos que presentamos en este artículo.

M. Torres-Cisneros; J. W. Haus; L. A. Aguilera-Cortés; R. Guzmán-Cabrera; R. Castro-Sánchez; E. Alvarado-Méndez; A. Andrade-Lucio; R. Rojas-Laguna; J. González-Barboza; J. Estudillo-Ayala; O. Ibarra-Manzano; Mónica Trejo; Ángel González

2012-01-01

33

STP Ising 1D Program  

Science.gov (United States)

The STP 1DIsing program is a Monte Carlo simulation of a one-dimensional Ising model in equilibrium with a heat bath at temperature T using the Metropolis algorithm. The default is N=64 spins up (s = 1) with no external field with heat bath temperature T=1. STP Ising1D is part of a suite of Open Source Physics programs that model aspects of Statistical and Thermal Physics (STP). The program is distributed as a ready-to-run (compiled) Java archive. Double clicking the stp_Ising1D.jar file will run the program if Java is installed on your computer. Additional programs can be found by searching ComPADRE for Open Source Physics, STP, or Statistical and Thermal Physics.

Gould, Harvey; Tobochnik, Jan; Christian, Wolfgang; Cox, Anne

2008-05-28

34

1D Quantum States Applet  

Science.gov (United States)

This simulation shows time-dependent 1D quantum bound state wavefunctions for a number of different wells. Position, momentum, parity, energy, and current can all be viewed, with phase shown with color. Eigentstates can be selected using the energy level diagram. Multiple-energy-eigenstate wavefunctions can be created through changes in the amplitude and phase of the basis states using spinors. Postion and energy measurements can be taken, resulting in new states of the system.

Falstad, Paul

2004-05-17

35

Effects of travel path and source structure on the character of regional distance seismograms from nuclear explosions. Final report, October 1989-February 1992  

Energy Technology Data Exchange (ETDEWEB)

A comprehensive or low-yield threshold test treaty will require monitoring at regional distances, and the seismograms are very difficult to deterministically model. The character of the phases Pg and Lg shows a very strong dependence on travel path. We have conducted a number of observation-based experiments to develop empirical path corrections or scaling relations for regional phase excitation and propagation. The gross crustal structure of the western syntaxis was determined and the blockage of Pg and Lg in the region was studied empirically. Eighteen events from the 1986 Chalfant Valley earthquake sequence were used to examine the effects of source magnitude, depth, and rock properties on the regional distance spectra of Pg, Lg, and Pn. For all three variables, the spectral ratios discriminant behaves in a linear fashion. We also reviewed the effects of tectonic release on seismic body waves generated by underground nuclear explosions.

Wallace, T.C.

1991-12-27

36

Effects of delay shooting on the nature of P-wave seismograms  

Energy Technology Data Exchange (ETDEWEB)

P-wave spectra have been computed from several mine blast records. Amplitudes of the low frequency peaks were found to correlate with the total size of the explosion. This agrees with theoretical source spectra calculations for multiple-delayed shots. The theoretical calculations also show that at higher frequencies (excepting multiples of the delay frequency), the spectral amplitudes are determined by the maximum charge per delay and not by the total charge size. Synthetic seismograms have been computed for various source and absorption models. It appears that the seismic waveforms are more sensitive to the number of rows and the row delay than they are to the total number of shots and the individual delays in a blast. 11 references.

Greenhalgh, S.A.

1980-12-01

37

Numerical seismogram computations for inhomogeneous media using a short, variable length convolutional differentiator  

Energy Technology Data Exchange (ETDEWEB)

A short convolutional differentiator (CD) for computing second spatial derivatives in the acoustic wave equation is presented. This differentiator is obtained by tapering the inverse Fourier transform of the band-limited Fourier spectrum of the second-derivative operator. This new filter has been applied to seismogram computations for inhomogeneous media and results are compared with the conventional high-order finite-difference (FD) and Fourier schemes. The operator can be progressively shortened at the model edges to reduce boundary artifacts. The CD method is superior to the conventional FD operator and comparable with the Fourier method in accuracy but faster to run. A strategy to reduce computation time by 20%, which exploits the localized nature of the operator, is given. The method is illustrated using simple 2D models.

Zhou, B.; Greenhalgh, S.A.; Zhe, J. (Flinders Univ. of South Australia, Adelaide (Australia). School of Earth Sciences)

1993-08-01

38

The May 18, 1998 Indian Nuclear Test Seismograms at station NIL  

Energy Technology Data Exchange (ETDEWEB)

The last underground nuclear tests were conducted by India and Pakistan in May 1998. Although the Comprehensive Test Ban Treaty has not entered force, an International Monitoring System (IMS), established by the treaty is nearing completion. This system includes 170 seismic stations, a number of them originally established by IRIS. The station IRIS station NIL (Nilore, Pakistan) is close to a planned IMS primary station and recorded some very interesting seismograms from the May 18, 1998 Indian test. We carefully calibrated the path to NIL using a prior Mw 4.4 that occurred on April 4, 1995 about 110 km north of the Indian test site. We used joint epicentral location techniques along with teleseismic P waves and regional surface waves to fix the epicenter, depth, mechanism and moment of this event. From these we obtained a velocity model for the path to NIL and created explosion synthetic seismograms to compare with the data. Interestingly the observed Rayleigh waves are reversed, consistent with an implosion rather than an explosion source. The preferred explanation is that the explosion released tectonic stress near the source region, which can be modeled as a thrust earthquake of approximate Mw 4.0 plus a pure explosion. This tectonic release is sufficient to completely dominate the Rayleigh waves and produce the observed signal (Walter et al. 2005). We also examined the explosion at high frequencies of 6 6-8 Hz where many studies have shown that relative P/S amplitudes can discriminate explosions from a background of earthquakes (Rodgers and Walter, 2002). Comparing with the April 4 1995 earthquake we see the classic difference of relatively large P/S values for the explosion compared to the earthquakes despite the complication of the large tectonic release during the explosion.

Walter, W R; Rodgers, A J; Bowers, D; Selby, N

2005-04-11

39

Tomography S Velocity Structure between Washington’s Earthquake C022801l and Observational Station Tuc through Seismogram Analysis  

Directory of Open Access Journals (Sweden)

Full Text Available In this research the S speed structure is investigated by seismogram analysis of Washington's earthquake, C022801L using data of TUC station, Tucson, Arizona, U.S.A. The seismogram comparison between the observed and the synthetic seismogram is conducted in time domain and three components simultaneously. The initially input for the calculation of synthetic seismogram is earth model of PREMAN and CMT solution from the earthquake. A low-pass Butterworth filter with corner frequency of 20 mHz is convolved to observed and synthetic seismogram. Waveform comparison shows a real deviation when travel time and waveform of some wave phase are compared, namely on S wave, surface wave of Love and Rayleigh and wave ScS and ScS-2. This research shows, how sensitive the waveform is to the earth model, better than the method of travel time or the dispersion analysis. Research hereinafter is addressed to finish the found discrepancies at S wave, surface wave of Love and Rayleigh and ScS and ScS-2 wave, in observation station TUC. To obtain the seismogram fitting, correction for S speed structure in earth model is needed, that are changes of earth crust thickness, the speed model of ? in upper mantle covering the speed gradient of ?h and value of zeroeth order coefficient for the ?h and ?v, for accomplishing the discrepancies at surface wave of Love and Rayleigh. Further correction on S speed is conducted to accomplish the deviation at S wave at earth layering systems from Upper Mantle up to a 630 km depth. Mean while for the ScS and ScS-2 wave phase the correction is carried out on S speed in the earth layers up to CMB. Fitting Seismogram is obtained at waveform of various wave phases that is S wave, surface wave of Love and Rayleigh and ScS, ScS-2 wave, either on travel time or especially also at oscillation number in Love wave. This result indicates that the anisotropy is occurred not only in upper mantle but till deeper earth layers, till CMB.

Bagus Jaya Santosa

2005-01-01

40

1D Signal Phase Unwrapper  

International Nuclear Information System (INIS)

Signal phase values are crucial in seismic data interpretation to enhance the analysis of amplitudes, bright spots, dim spots etc. Phase values can be zeroed in a section to enhance signal comparison which can be related to velocities and other petro-physical properties. Homomorphic signal processing and deconvolution both require exact phase value estimates. Consequently, in-depth investigations are necessary to solve problems of phase estimation in various wave propagation situations. Meanwhile, phase values are often measured modulo-2 called principal values and the amount of phase estimation in various wave propagation situations. Meanwhile, values are often measured modulo-2 called principal values and the amount of phase information is independent of any integer multiple of 2 added to the principal value phase. However, to be useful for linear processing, this principal value phase has to be unwrapped. This will result in a continuous function, the 2 discontinuities being eliminated, or at least reduced. Operations like deconvolution and homomorphic signal processing require unwrapped phase values. Phase unwrapping is applied to pre-stack data for the computation of PVA phase variation with angle of incidence attribute used to improve processing and interpretation.Conventional 1D phase unwrapping algorithms integrate the wrapped phase difference between two contiguous points. This was later improved to use adaptive integration of phase differences. Alternatively, phase difference ambiguity due to sparse sampling can be overcome by taking samples at progressively closer intervals. These methods are often inadequate due to problems of aliasing caused by rapid phase value variations. We develop a 1D phase unwrapping technique using the amplitude of a complex trace and discrete Fourier transforms. This technique is simple, very reliable and less sensitive to aliasing. It exploits the periodicity of Fourier transform to unwind wrapped phase values. We demonstrate this technique using synthetic and real data.

2002-01-01

 
 
 
 
41

NKT TCR recognition of CD1d-?-C-galactosylceramide.  

Science.gov (United States)

NKT cells respond to a variety of CD1d-restricted glycolipid Ags that are structurally related to the prototypic Ag ?-galactosylceramide (?-GalCer). A modified analog of ?-GalCer with a carbon-based glycosidic linkage (?-C-GalCer) has generated great interest because of its apparent ability to promote prolonged, Th1-biased immune responses. In this study, we report the activation of spleen NKT cells to ?-C-GalCer, and related C-glycoside ligands, is weaker than that of ?-GalCer. Furthermore, the V?8.2 and V?7 NKT TCR affinity for CD1d-?-C-GalCer, and some related analogs, is ?10-fold lower than that for the NKT TCR-CD1d-?-GalCer interaction. Nevertheless, the crystal structure of the V?8.2 NKT TCR-CD1d-?-C-GalCer complex is similar to that of the corresponding NKT TCR-CD1d-?-GalCer complex, although subtle differences at the interface provide a basis for understanding the lower affinity of the NKT TCR-CD1d-?-C-GalCer interaction. Our findings support the concept that for CD1d-restricted NKT cells, altered glycolipid ligands can promote markedly different responses while adopting similar TCR-docking topologies. PMID:21964029

Patel, Onisha; Cameron, Garth; Pellicci, Daniel G; Liu, Zheng; Byun, Hoe-Sup; Beddoe, Travis; McCluskey, James; Franck, Richard W; Castaño, A Raúl; Harrak, Youssef; Llebaria, Amadeu; Bittman, Robert; Porcelli, Steven A; Godfrey, Dale I; Rossjohn, Jamie

2011-09-30

42

NKT TCR recognition of CD1d-?-C-galactosylceramide.  

UK PubMed Central (United Kingdom)

NKT cells respond to a variety of CD1d-restricted glycolipid Ags that are structurally related to the prototypic Ag ?-galactosylceramide (?-GalCer). A modified analog of ?-GalCer with a carbon-based glycosidic linkage (?-C-GalCer) has generated great interest because of its apparent ability to promote prolonged, Th1-biased immune responses. In this study, we report the activation of spleen NKT cells to ?-C-GalCer, and related C-glycoside ligands, is weaker than that of ?-GalCer. Furthermore, the V?8.2 and V?7 NKT TCR affinity for CD1d-?-C-GalCer, and some related analogs, is ?10-fold lower than that for the NKT TCR-CD1d-?-GalCer interaction. Nevertheless, the crystal structure of the V?8.2 NKT TCR-CD1d-?-C-GalCer complex is similar to that of the corresponding NKT TCR-CD1d-?-GalCer complex, although subtle differences at the interface provide a basis for understanding the lower affinity of the NKT TCR-CD1d-?-C-GalCer interaction. Our findings support the concept that for CD1d-restricted NKT cells, altered glycolipid ligands can promote markedly different responses while adopting similar TCR-docking topologies.

Patel O; Cameron G; Pellicci DG; Liu Z; Byun HS; Beddoe T; McCluskey J; Franck RW; Castaño AR; Harrak Y; Llebaria A; Bittman R; Porcelli SA; Godfrey DI; Rossjohn J

2011-11-01

43

Regional and Upper-Mantle Structure Model of Peninsular India and Relevance to High-Frequency Lg Seismograms  

Science.gov (United States)

The primary objective of this study is to develop regional and upper-mantle crustal structures of Peninsular India for estimating source parameters of smaller seismic events. To this end, we modeled regional seismograms generated by the May 21, 1997 Jabalpur earthquake in central India which occurred in the lower crust at a depth of 35 km. It was recorded at many teleseismic stations with usable signal-to-noise ratio, including several broadband regional stations in India. Teleseismic P waves were used to establish the complexity of the source process, focal mechanism and source depth of the earthquake by modeling amplitude and travel times of the pP and sP depth phases relative to the P wave onsets. Regional waveforms from this master event with known source parameters were used to develop corresponding Greens' functions for the paths to stations, namely Bhopal (BHPL), Bilaspur (BLSP) and Hyderabad (HYB). The complexity in teleseismic P and sP can also be observed in Pn and sPn with excellent compatibility. These same features can be identified in upper-mantle triplications at LSA (? =12° ), NIL (Delta=12° ), CHTO (? =18° ), and AAK (Delta=20° ) when modeled with existing shield models. The upper-mantle Pn phases (i.e., pP, sP, sPn, sSP, sPP, sPPPP etc.) can be positively identified in these observations and were found to be sensitive to the presence of gradient in the transition zones, especially beneath the 400 km discontinuity. The usefulness of these Green's functions is demonstrated by modeling the regional and sparse teleseismic data for a small earthquake (April 4, 1995) located near the Indian Nuclear Test Site at Pokhran. This study also establishes a regional waveguide for the path from the Pokhran Test Site to station Nilore (NIL) in Pakistan. We have also extended these regional models to have the capability of generating high-frequency Lg waves by introducing thin layers in the crust with alternating high and low-velocity distribution.

Saikia, C. K.

2003-12-01

44

Wavelet transform analysis of transient signals: the seismogram and the electrocardiogram  

Energy Technology Data Exchange (ETDEWEB)

In this dissertation I quantitatively demonstrate how the wavelet transform can be an effective mathematical tool for the analysis of transient signals. The two key signal processing applications of the wavelet transform, namely feature identification and representation (i.e., compression), are shown by solving important problems involving the seismogram and the electrocardiogram. The seismic feature identification problem involved locating in time the P and S phase arrivals. Locating these arrivals accurately (particularly the S phase) has been a constant issue in seismic signal processing. In Chapter 3, I show that the wavelet transform can be used to locate both the P as well as the S phase using only information from single station three-component seismograms. This is accomplished by using the basis function (wave-let) of the wavelet transform as a matching filter and by processing information across scales of the wavelet domain decomposition. The `pick` time results are quite promising as compared to analyst picks. The representation application involved the compression of the electrocardiogram which is a recording of the electrical activity of the heart. Compression of the electrocardiogram is an important problem in biomedical signal processing due to transmission and storage limitations. In Chapter 4, I develop an electrocardiogram compression method that applies vector quantization to the wavelet transform coefficients. The best compression results were obtained by using orthogonal wavelets, due to their ability to represent a signal efficiently. Throughout this thesis the importance of choosing wavelets based on the problem at hand is stressed. In Chapter 5, I introduce a wavelet design method that uses linear prediction in order to design wavelets that are geared to the signal or feature being analyzed. The use of these designed wavelets in a test feature identification application led to positive results. The methods developed in this thesis; the feature identification methods of Chapter 3, the compression methods of Chapter 4, as well as the wavelet design methods of Chapter 5, are general enough to be easily applied to other transient signals.

Anant, K.S.

1997-06-01

45

Ratios in Higher Order Statistics (RHOS) values of Seismograms for Improved Automatic P-Phase Arrival Detection  

CERN Multimedia

In this paper we present two new procedures for automatic detection and picking of P-wave arrivals. The first involves the application of kurtosis and skewness on the vector magnitude of three component seismograms. Customarily, P-wave arrival detection techniques use vertical component seismogram which is appropriate only for teleseismic events. The inherent weakness of those methods stems from the fact that the energy from P-wave is distributed among horizontal and vertical recording channels. Our procedure, however, uses the vector magnitude which accommodates all components. The results show that this procedure would be useful for detecting/picking of P-arrivals from local and regional earthquakes and man-made explosions. The second procedure introduces a new method called "Ratios in Higher Order Statistics (RHOS)." Unlike commonly used techniques that involve derivatives, this technique employs ratios of adjacent kurtosis and skewness values to improve the accuracy of the detection of the P onset. RHOS c...

Dugda, Mulugeta

2010-01-01

46

Detection and identification of sources of very distant seismic events in Western United States using single array seismograms  

International Nuclear Information System (INIS)

In search of a new source discriminant based on the characteristics of PP signal, a study has been made by special further processing of Gauribidanur array (GBA) seismograms of underground explosions at Nevada Test Site (NTS) in Southern Nevada and of tectonic earthquakes in five provinces in the Western United States (US), both class of events being situated in the far teleseismic distance range (120deg

1993-01-01

47

MineSeis -- A MATLAB GUI program to calculate synthetic seismograms from a linear, multi-shot blast source model  

Energy Technology Data Exchange (ETDEWEB)

Modeling ground motions from multi-shot, delay-fired mining blasts is important to the understanding of their source characteristics such as spectrum modulation. MineSeis is a MATLAB{reg_sign} (a computer language) Graphical User Interface (GUI) program developed for the effective modeling of these multi-shot mining explosions. The program provides a convenient and interactive tool for modeling studies. Multi-shot, delay-fired mining blasts are modeled as the time-delayed linear superposition of identical single shot sources in the program. These single shots are in turn modeled as the combination of an isotropic explosion source and a spall source. Mueller and Murphy`s (1971) model for underground nuclear explosions is used as the explosion source model. A modification of Anandakrishnan et al.`s (1997) spall model is developed as the spall source model. Delays both due to the delay-firing and due to the single-shot location differences are taken into account in calculating the time delays of the superposition. Both synthetic and observed single-shot seismograms can be used to construct the superpositions. The program uses MATLAB GUI for input and output to facilitate user interaction with the program. With user provided source and path parameters, the program calculates and displays the source time functions, the single shot synthetic seismograms and the superimposed synthetic seismograms. In addition, the program provides tools so that the user can manipulate the results, such as filtering, zooming and creating hard copies.

Yang, X.

1998-12-31

48

Two extensions of 1D Toda hierarchy  

International Nuclear Information System (INIS)

The extended Toda hierarchy of Carlet, Dubrovin and Zhang is reconsidered in light of a 2 + 1D extension of the 1D Toda hierarchy constructed by Ogawa. These two extensions of the 1D Toda hierarchy turn out to have a very similar structure, and the former may be thought of as a kind of dimensional reduction of the latter. In particular, this explains an origin of the mysterious structure of the bilinear formalism proposed by Milanov.

2010-10-29

49

Study of East Kazakh explosions and propagation in Central Asia using regional Chinese seismograms  

Energy Technology Data Exchange (ETDEWEB)

Seismograms recorded at the Urumchi Station in northwestern China from eleven Asian events including seven presumed East Kazakh nuclear explosions were analyzed. Group velocity dispersion curves of Rayleigh waves were measured at short periods on paths through basin and fold belt terrains. At 10 sec period, the velocities on paths over sedimentary basins are 25% slower than velocities on paths over fold belts. We interpret those differences in velocities to be due to the great thicknesses of sedimentary deposits in basin terrains. Epicentral locations were estimated using differential travel times between P/sub n/ and L/sub g/ and particle motions of Rayleigh waves measured on a single three-component record. For a 1000 km path, the location errors (one standad deviation) are about +-125 km in azimuth and +-30 km in distance. In addition, systematic errors due to structural effects on surface-wave paths and on velocities of regional phases are shown to seriously bias location estimates of several events. We applied a differential phase method to Rayleigh waves from the East Kazakh explosions and found that signals of all events are in-phase with signals from the reference event on 10/12/80. Thus, there is no evidence for phase reversals or shifts at the Urumchi station in the frequency band where signal to noise ratio is good and where assumptions of the method are valid. Seismic moments of explosions were estimated using models of explosion sources with associated tectonic release. Observed amplitude spectra of Rayleigh waves were richer in high frequencies than predicted by the model. This could be a source effect related to source medium excitation (i.e., Green's functions) or a path effect caused by energy focussing and/or amplifications. We discuss the potential bias in the estimates of moment due to assumptions/limitations. 24 references, 16 figures, 6 tables.

Patton, H.J.; Mills, J.M. Jr.

1984-03-01

50

Study of East Kazakh explosions and propagation in Central Asia using regional Chinese seismograms  

International Nuclear Information System (INIS)

Seismograms recorded at the Urumchi Station in northwestern China from eleven Asian events including seven presumed East Kazakh nuclear explosions were analyzed. Group velocity dispersion curves of Rayleigh waves were measured at short periods on paths through basin and fold belt terrains. At 10 sec period, the velocities on paths over sedimentary basins are 25% slower than velocities on paths over fold belts. We interpret those differences in velocities to be due to the great thicknesses of sedimentary deposits in basin terrains. Epicentral locations were estimated using differential travel times between P/sub n/ and L/sub g/ and particle motions of Rayleigh waves measured on a single three-component record. For a 1000 km path, the location errors (one standad deviation) are about +-125 km in azimuth and +-30 km in distance. In addition, systematic errors due to structural effects on surface-wave paths and on velocities of regional phases are shown to seriously bias location estimates of several events. We applied a differential phase method to Rayleigh waves from the East Kazakh explosions and found that signals of all events are in-phase with signals from the reference event on 10/12/80. Thus, there is no evidence for phase reversals or shifts at the Urumchi station in the frequency band where signal to noise ratio is good and where assumptions of the method are valid. Seismic moments of explosions were estimated using models of explosion sources with associated tectonic release. Observed amplitude spectra of Rayleigh waves were richer in high frequencies than predicted by the model. This could be a source effect related to source medium excitation (i.e., Green's functions) or a path effect caused by energy focussing and/or amplifications. We discuss the potential bias in the estimates of moment due to assumptions/limitations. 24 references, 16 figures, 6 tables.

1984-01-01

51

Seismogram Analysis of the Earthquakes in Sumatra on WRAB Observation Station: S Wave Velocity Structure on Subduction Zone of Sumatra-Java  

Directory of Open Access Journals (Sweden)

Full Text Available The S wave velocity structure at subduction zone under Sumatra-Java was investigated through seismogram analysis in time domain and three Cartesian’s components simultaneously. The main data set was the comparison between the measured seismogram and the synthetic one, not the travel time data. The synthetic seismogram was calculated with the GEMINI method. The seismogram comparison shows that the global earth mantle of PREMAN gives deviating synthetic seismogram and has later arrival times than the measured one. The gradient bh in the upper mantle is altered to positive from its negative slope as in the PREMAN model, and positive corrections are added to the zero order of polynomial’s coefficients in all earth mantle layers. The excellent fitting, as well as travel time or waveform, were obtained on the surface waves of Love and Rayleigh, the S and SS mantle and repetitive depth waves. The additional positive corrections were also confirmed by a well fitting on the repetitive depth waves. This result expresses that part of the earth mantle that due to tectonic processes has positive anomaly on S wave velocity and vertical anisotropy in all of the earth mantle layers.

Bagus Jaya Santosa

2008-01-01

52

The T1D Exchange clinic registry.  

UK PubMed Central (United Kingdom)

CONTEXT: The T1D Exchange includes a clinic-based registry, a patient-centric web site called Glu, and a biobank. OBJECTIVE: The aim of the study was to describe the T1D Exchange clinic registry and provide an overview of participant characteristics. DESIGN: Data obtained through participant completion of a questionnaire and chart extraction include diabetes history, management, and monitoring; general health; lifestyle; family history; socioeconomic factors; medications; acute and chronic diabetic complications; other medical conditions; and laboratory results. SETTING: Data were collected from 67 endocrinology centers throughout the United States. PATIENTS: We studied 25,833 adults and children with presumed autoimmune type 1 diabetes (T1D). RESULTS: Participants ranged in age from less than 1 to 93 yr, 50% were female, 82% were Caucasian, 50% used an insulin pump, 6% used continuous glucose monitoring, and 16% had a first-degree family member with T1D. Glycosylated hemoglobin at enrollment averaged 8.3% and was highest in 13 to 25 yr olds. The prevalence of renal disease was ?4% until T1D was present for at least 10 yr, and retinopathy treatment was ?2% until T1D was present for at least 20 yr. A severe hypoglycemic event (seizure or coma) in the prior 12 months was reported by 7% of participants and diabetic ketoacidosis in the prior 12 months by 8%. CONCLUSIONS: The T1D Exchange clinic registry provides a database of important information on individuals with T1D in the United States. The rich dataset of the registry provides an opportunity to address numerous issues of relevance to clinicians and patients, including assessments of associations between patient characteristics and diabetes management factors with outcomes.

Beck RW; Tamborlane WV; Bergenstal RM; Miller KM; DuBose SN; Hall CA

2012-12-01

53

Social exploration of 1D games.  

DEFF Research Database (Denmark)

In this paper the apparently meaningless concept of a 1 dimensional computer game is explored, via netnography. A small number of games was designed and implemented, in close contact with online communities of players and developers, providing evidence that 1 dimension is enough to produce interesting gameplay, to allow for level design and even to leave room for artistic considerations on 1D rendering. General techniques to re-design classic 2D games into 1D are also emerging from this exploration.

Valente, Andrea; Marchetti, Emanuela

2013-01-01

54

Social exploration of 1D games  

DEFF Research Database (Denmark)

In this paper the apparently meaningless concept of a 1 dimensional computer game is explored, via netnography. A small number of games was designed and implemented, in close contact with online communities of players and developers, providing evidence that 1 dimension is enough to produce interesting gameplay, to allow for level design and even to leave room for artistic considerations on 1D rendering. General techniques to re-design classic 2D games into 1D are also emerging from this exploration.

Valente, Andrea; Marchetti, Emanuela

2013-01-01

55

STP Random Walk 1D Program  

Science.gov (United States)

The RandomWalk1D program simulates a random walk in one dimension for steps of unit length and equal time intervals. The default number of steps is N = 16 and the probability of going right or left at any step is the same (the probability p of going to the right for a single step is 0.5). RandomWalk1D is part of a suite of Open Source Physics programs that model aspects of Statistical and Thermal Physics (STP). The program is distributed as a ready-to-run (compiled) Java archive. Double clicking the stp RandomWalk1D.jar file will run the program if Java is installed on your computer. Additional programs can be found by searching ComPADRE for Open Source Physics, STP, or Statistical and Thermal Physics.

Gould, Harvey; Tobochnik, Jan; Christian, Wolfgang; Cox, Anne

2008-10-10

56

Coupling method of 1-d/1-d and 1-d/3-d junctions for an implict WCOBRA/TRAC  

Energy Technology Data Exchange (ETDEWEB)

COBRA/TRAC is an advanced thermal-hydraulic computer code, originally developed by Battelle Pacific Northwest Laboratories. The code combines a two-fluid, three-dimensional (3-d) program, COBRA-TF, with a one-dimensional (1-d) drift flux program, TRAC-PD2. COBRA-TF is designed to be used to model the pressurized water reactor (PWR), and loop components are modeled with TRAC-PD2. An implicit method was proposed for the COBRA part of the code, and some success was achieved as demonstrated by an analysis of a film-boiling experiment for a steady-state and power ascension transient. On the other hand, TRAC-PD2 includes an option to choose a semi-implicit or an implicit method in solving component equations. This implicit option improves running time somewhat, but the junctions among the components are treated semi-implicitly. So, the time step is controlled by the Courant numbers at the 1-d/3-d and 1-d/1-d component junctions. In order to speed up the code further, the solution method for the junctions must be changed to implicit. An implicit method is introduced. It is evaluated by a COBRA/TRAC model of a less-of-fluid test (LOFT) and a two-loop PWR.

Takeuchi, K.; Young, M.Y.

1988-01-01

57

PALLAS-1D(V3): variable-dimension version of PALLAS-1D(VII)  

International Nuclear Information System (INIS)

[en] The PALLAS-1D(V3) program is a variable-dimension version of the PALLAS-1D(VII) code, which is the revised version of the PALLAS-PL, SP-Br code. The PALLAS-1D(VII) code could treat transport of both neutrons and gamma rays, in particular of secondary photons including the bremsstrahlung and annihilation photons. This document gives a full description of input and output data for PALLAS-1D(V3) code, also with the input description of several sample problems. (author)

1990-01-01

58

Radiative transfer theory for the fractal structure and power-law decay characteristics of short-period seismograms  

Science.gov (United States)

For short period S-wave seismograms of an earthquake, the maximum amplitude decreases according to a power of traveltime, and the coda amplitude also decreases according to a power of lapse time measured from the earthquake origin time. The radiative transfer theory has been often used for the envelope synthesis of complex seismograms composed of scattered waves due to random heterogeneities in the Earth medium; however, the conventional theory, which supposes uniform distributions of scatterers (heterogeneities) and intrinsic absorbers, predicts that both the ballistic term amplitude and the coda wave amplitude exponentially decrease with time increasing in addition to the geometrical decay. In order to explain their power-law characteristics, this paper proposes the radiative transfer theory for a fractally random and homogeneous distribution of isotropic scatterers and intrinsic absorbers with fractal dimension D ? 3 in the 3-D space: the number density of scatterers/absorbers in a sphere of radius r is proportional to rD - 3 for distance r ? rc but constant for r ? rc, where the corner distance rc is introduced to avoid divergence at a small r. The case of D = 3 corresponds to the conventional uniform distribution. For the case of D = 2, the theory well predicts that the mean square (MS) amplitude of the ballistic-wave decreases according to a power of traveltime and the MS amplitude of coda waves decreases according to a power of lapse time measured from the origin time, where each power is controlled by the scattering coefficient, intrinsic absorption coefficient and corner distance. For the case of D = 1, the ballistic-wave MS amplitude decay is the inverse square of time and the coda decay is much faster. As a preliminary work, fixing D = 2 as a priori choice, we analyse S-seismogram envelopes of a local earthquake in Japan. The case study shows that the radiative transfer theory for a fractal scattering medium is useful for the study of the distribution of small-scale heterogeneities in the Earth medium.

Sato, Haruo; Fukushima, Rintaro

2013-09-01

59

The analysis of historical seismograms: an important tool for seismic hazard assessment. Case histories from French and Italian earthquakes  

International Nuclear Information System (INIS)

Seismic hazard assessment relies on the knowledge of the source characteristics of past earthquakes. Unfortunately, seismic waveform analysis, representing the most powerful tool for the investigation of earthquake source parameters, is only possible for events occurred in the last 100-120 years, i.e., since seismographs with known response function were developed. Nevertheless, during this time significant earthquakes have been recorded by such instruments and today, also thanks to technological progress, these data can be recovered and analysed by means of modern techniques. In this paper, aiming at giving a general sketch of possible analyses and attainable results in historical seismogram studies, I briefly describe the major difficulties in processing the original waveforms and present a review of the results that I obtained from previous seismogram analysis of selected significant historical earthquakes occurred during the first decades of the 20. century, including (A) the December 28, 1908, Messina straits (southern Italy), (B) the June 11, 1909, Lambesc (southern France) - both of which are the strongest ever recorded instrumentally in their respective countries - and (C) the July 13, 1930, Irpinia (southern Italy) events. For these earthquakes, the major achievements are represented by the assessment of the seismic moment (A, B, C), the geometry and kinematics of faulting (B, C), the fault length and an approximate slip distribution (A, C). The source characteristics of the studied events have also been interpreted in the frame of the tectonic environment active in the respective region of interest. In spite of the difficulties inherent to the investigation of old seismic data, these results demonstrate the invaluable and irreplaceable role of historical seismogram analysis in defining the local seismo-genic potential and, ultimately, for assessing the seismic hazard. The retrieved information is crucial in areas where important civil engineering works are planned, as in the case of the single-span bridge to be built across the Messina straits and the ITER nuclear fusion power plant to be built in Cadarache, close to the location of the Lambesc event, and in regions characterized by high seismic risk, such as southern Appennines. (author)

2011-01-01

60

DOE-2 Supplement, Version 2. 1D  

Energy Technology Data Exchange (ETDEWEB)

This package of updates to the DOE-2 documentation brings the previously published materials (with the exception of the Users Guide) up to Version 2.1D of the DOE-2 program. The user may verify that the program being used is 2.1D by checking the first page of the output and also the upper right hand heading of any output page of the computer printout. This document contains in concise form the basis information on all commands and keywords in the DOE-2 Building Description Language (BDL) as well as a number of supplementary tables and maps.

1989-06-01

 
 
 
 
61

Polydiacetylene-Peptide 1D Nanomaterials.  

Science.gov (United States)

Polydiacetylenes have received intense attention on account of their well-established chromic alterations that are detectable often by the naked eye, making them ideal for a variety of applications such as biosensory materials. These polymers have been fabricated in a variety of materials platforms including 3D crystals, 2D monolayers, and 0D spherical vesicles; however, 1D morphologies that might be useful for directional energy migration are less common. This article describes the development and current research efforts of protein-based 1D nanowire-like supramolecular assemblies with embedded polydiacetylenes. PMID:23922317

Diegelmann, Stephen R; Tovar, John D

2013-08-06

62

Polydiacetylene-Peptide 1D Nanomaterials.  

UK PubMed Central (United Kingdom)

Polydiacetylenes have received intense attention on account of their well-established chromic alterations that are detectable often by the naked eye, making them ideal for a variety of applications such as biosensory materials. These polymers have been fabricated in a variety of materials platforms including 3D crystals, 2D monolayers, and 0D spherical vesicles; however, 1D morphologies that might be useful for directional energy migration are less common. This article describes the development and current research efforts of protein-based 1D nanowire-like supramolecular assemblies with embedded polydiacetylenes.

Diegelmann SR; Tovar JD

2013-09-01

63

First Observation of Upsilon(1D) States  

CERN Multimedia

The CLEO III experiment has recently accumulated a large statistics sample of 4.73 x 10^6 Upsilon(3S) decays. We present the first evidence for the production of the triplet Upsilon(1D) states in the four-photon cascade, Upslion(3S) -> gamma chi_b(2P), chi_b(2P) -> gamma Upsilon(1D), Upsilon(1D) -> gamma chi_b(1P), chi_b(1P) -> gamma Upsilon(1S), followed by the Upsilon(1S) annihilation to e+ e- or mu+ mu-. The signal has a significance of 9.7 standard deviations. The measured product branching ratio for these five decays, (3.3 +- 0.6 +- 0.5) x 10^{-5}, is consistent with the theoretical estimates. We see a 6.8 standard deviation signal for a state with a mass of 10162.2 +- 1.6 MeV/c^2, consistent with the Upsilon(1D_2) assignment. We also present improved measurements of the Upsilon(3S) -> pi0 pi0 Upsilon(1S) branching ratio and the associated di-pion mass distribution.

Csorna, S E; Bonvicini, G; Cinabro, D; Dubrovin, M; McGee, S; Bornheim, A; Lipeles, E; Pappas, S P; Shapiro, A; Sun, W M; Weinstein, A J; Mahapatra, R; Briere, R A; Chen, G P; Ferguson, T; Tatishvili, G T; Vogel, H; Adam, N E; Alexander, J P; Berkelman, K; Boisvert, V; Cassel, David G; Drell, P S; Duboscq, J E; Ecklund, K M; Ehrlich, R; Galik, R S; Gibbons, L; Gittelman, B; Gray, S W; Hartill, D L; Heltsley, B K; Hsu, L; Jones, C D; Kandaswamy, J; Kreinick, D L; Magerkurth, A; Mahlke-Krüger, H; Meyer, T O; Mistry, N B; Nordberg, E; Patterson, J R; Peterson, D; Pivarski, J; Riley, D; Sadoff, A J; Schwarthoff, H; Shepherd, M R; Thayer, J G; Urner, D; Viehhauser, G; Warburton, A; Weinberger, M; Athar, S B; Avery, P; Breva-Newell, L; Potlia, V; Stöck, H; Yelton, J; Brandenburg, G; Kim, D Y J; Wilson, R; Benslama, K; Eisenstein, B I; Ernst, J; Gollin, G D; Hans, R M; Karliner, I; Lowrey, N; Plager, C; Sedlack, C; Selen, M; Thaler, J J; Williams, J; Edwards, K W; Ammar, R; Besson, D; Zhao, X; Anderson, S; Frolov, V V; Kubota, Y; Lee, S J; Li, S Z; Poling, R A; Smith, A; Stepaniak, C J; Urheim, J; Metreveli, Z V; Seth, K K; Tomaradze, A G; Zweber, P; Ahmed, S; Alam, M S; Jian, L; Saleem, M; Wappler, F; Eckhart, E; Gan, K K; Gwon, C; Hart, T; Honscheid, K; Hufnagel, D; Kagan, H; Kass, R; Pedlar, T K; Thayer, J B; Von Törne, E; Wilksen, T; Zoeller, M M; Muramatsu, H; Richichi, S J; Severini, H; Skubic, P L; Dytman, S A; Müller, J A; Nam, S; Savinov, V; Chen, S; Hinson, J W; Lee, J; Miller, D H; Pavlunin, V; Shibata, E I; Shipsey, I P J; Cronin-Hennessy, D; Lyon, A L; Park, C S; Park, W; Thorndike, E H; Coan, T E; Gao, Y S; Liu, F; Maravin, Y; Stroynowski, R; Artuso, M; Boulahouache, C; Bukin, K; Dambasuren, E; Khroustalev, K; Mountain, R; Nandakumar, R; Skwarnicki, T; Stone, S; Wang, J C; Mahmood, A H

2002-01-01

64

1-D equations of radiation hydrodynamics  

International Nuclear Information System (INIS)

The radiation transfer equation is derived in the comoving frame, in curvilinear coordinates, to first order in u/c, no symmetry being assumed. This equation is then specialized to 1-D, and its moments are calculated for the limiting case of Thomson scattering. The equations of radiation hydrodynamics are also given

1985-01-01

65

Entanglement teleportation through 1D Heisenberg chain  

Energy Technology Data Exchange (ETDEWEB)

Information transmission of two qubits through two independent 1D Heisenberg chains as a quantum channel is analyzed. It is found that the entanglement of two spin-12 quantum systems is decreased during teleportation via the thermal mixed state in 1D Heisenberg chain. The entanglement teleportation will be realized if the minimal entanglement of the thermal mixed state is provided in such quantum channel. High average fidelity of teleportation with values larger than 2/3 is obtained when the temperature T is very low. The mutual information I of the quantum channel declines with the increase of the temperature and the external magnetic field. The entanglement quality of input signal states cannot enhance mutual information of the quantum channel.

Hao Xiang [China Center of Advanced Science and Technology (World Laboratory), PO Box 8730, Beijing 100080 (China); School of Physical Science and Technology, Suzhou University, Suzhou, Jiangsu 215006 (China); Zhu Shiqun [China Center of Advanced Science and Technology (World Laboratory), PO Box 8730, Beijing 100080 (China) and School of Physical Science and Technology, Suzhou University, Suzhou, Jiangsu 215006 (China)]. E-mail: szhu@suda.edu.cn

2005-05-02

66

Entanglement teleportation through 1D Heisenberg chain  

International Nuclear Information System (INIS)

[en] Information transmission of two qubits through two independent 1D Heisenberg chains as a quantum channel is analyzed. It is found that the entanglement of two spin-12 quantum systems is decreased during teleportation via the thermal mixed state in 1D Heisenberg chain. The entanglement teleportation will be realized if the minimal entanglement of the thermal mixed state is provided in such quantum channel. High average fidelity of teleportation with values larger than 2/3 is obtained when the temperature T is very low. The mutual information I of the quantum channel declines with the increase of the temperature and the external magnetic field. The entanglement quality of input signal states cannot enhance mutual information of the quantum channel

2005-05-02

67

YORP torques with 1D thermal model  

CERN Multimedia

A numerical model of the Yarkovsky-O'Keefe-Radzievskii-Paddack (YORP) effect for objects defined in terms of a triangular mesh is described. The algorithm requires that each surface triangle can be handled independently, which implies the use of a 1D thermal model. Insolation of each triangle is determined by an optimized ray-triangle intersection search. Surface temperature is modeled with a spectral approach; imposing a quasi-periodic solution we replace heat conduction equation by the Helmholtz equation. Nonlinear boundary conditions are handled by an iterative, FFT based solver. The results resolve the question of the YORP effect in rotation rate independence on conductivity within the nonlinear 1D thermal model regardless of the accuracy issues and homogeneity assumptions. A seasonal YORP effect in attitude is revealed for objects moving on elliptic orbits when a nonlinear thermal model is used.

Breiter, Slawomir; Czekaj, Maria

2010-01-01

68

Better 1D predictions by experts with machines.  

UK PubMed Central (United Kingdom)

Accuracy of predicting protein secondary structure and solvent accessibility has been improved significantly by using evolutionary information contained in multiple sequence alignments. For the second Asilomar meeting, predictions were made automatically for all targets using the publicly available prediction service PredictProtein. Additionally, a semiautomatic procedure for generating more informative alignments was used in combination with the PHD prediction methods. Results confirmed the estimates for prediction accuracy. Furthermore, the more informative alignments yielded better predictions. The fairly accurate predictions of 1D structure were successfully used by various groups for the Asilomar meeting as first step toward predicting higher dimensions of protein structure.

Rost B

1997-01-01

69

Finite thermal conductivity in 1d lattices  

CERN Document Server

We discuss the thermal conductivity of a chain of coupled rotators, showing that it is the first example of a 1d nonlinear lattice exhibiting normal transport properties in the absence of an on-site potential. Numerical estimates obtained by simulating a chain in contact with two thermal baths at different temperatures are found to be consistent with those ones based on linear response theory. The dynamics of the Fourier modes provides direct evidence of energy diffusion. The finiteness of the conductivity is traced back to the occurrence of phase-jumps. Our conclusions are confirmed by the analysis of two variants of this model.

Giardinà, C; Politi, A; Vassalli, M

2000-01-01

70

Synthesis of magnetic 1D dichalcogenide nanostructures  

International Nuclear Information System (INIS)

[en] We report the first synthesis of magnetic one-dimensional transition metal dichalcogenides. Pure and Mn-doped tantalum disulfide nanotapes were synthesized using a catalyst-free single-step growth process. The sample yield of nanostructures was nearly 100 %. The nanotapes were composed of a number of smaller nanowires which appear to be open-ended nanotubes. The smaller nanowires have diameters ranging from about 30 to 300 nm. The Mn dopants were incorporated within intercalation sites between TaS2 layers. Interactions between these dopant ions induced low temperature magnetic phase transitions similar to those seen in macroscopic MnxTaS2 compounds. The magnetic properties do not exactly correspond to their bulk counterparts, as exemplified by a higher than expected ferromagnetic transition temperature in 1D nanostructures. This indicates the magnetic properties are likely influenced by quantum size effects. The simplicity of this one-step synthesis method should allow for this technique to be extended to other dichalcogenide systems and/or magnetic dopants, opening up a new class of 1D magnetic nanostructures.

2012-01-01

71

Seismic site effects and the spatial interpolation of earthquake seismograms: results using aftershocks of the 1986 North Palm Springs, California, earthquake  

Science.gov (United States)

We address the following two questions. Can a microearthquake's ground motions be modeled by incident P and S waves that excite a site transfer-function that is a smooth function of incidence angle? Given recorded ground motions from a set of earthquakes having known locations and mechanisms, can we derive such a site transfer-function and use it to obtain the ground motions that would result from an earthquake source occurring somewhere in the same volume but having a location and mechanism that are different from the recorded events? We express the site transfer-function as a sum of several terms having simple dependences upon incidence angle and azimuth. Each term is an independent function of time. Given a set of seismograms observed at the site, we solve a linear system of equations for the time dependences of each term. These time series may be used to calculate the seismograms that would have resulted from an earthquake having arbitrary mechanism and location. This step is an interpolation. We have applied this technique to seismograms after aftershocks of the 1986 North Palm Springs earthquake. -from Authors

Spudich, P.; Miller, D. P.

1990-01-01

72

FAST TRACK PAPER: INVSP gathers of local earthquake seismograms: an approach for modelling the upper crustal P and S velocity structure  

Science.gov (United States)

A new approach is presented here for obtaining INVSP gathers of local earthquake seismograms in regions with adequate seismogenic depth range. The inverse vertical seismic profiling (INVSP) geometry is in principle quite similar to the up-hole surveys of shallow seismic exploration in which shots fired at various depths in boreholes are recorded on the surface at a fixed offset. Similarly, local earthquake seismograms of `selected' events at different hypocentral depths can be gathered into `Constant offset INVSP' sections for various stations of a mobile seismograph network. They can be modelled for P and S velocity structure to upper crustal depths at each of the stations in the network with the aid of synthetic seismogram computations using appropriate source mechanisms of the earthquakes used. An INVSP gather, obtained to a depth range of about 10 km at a station with 28 km constant offset, is modelled for the upper crustal P and S velocity structure in the Koyna-Warna seismic region in the western Indian shield to demonstrate this approach.

Krishna, V. G.

2006-07-01

73

Natural Killer T-cell receptor recognition of CD1d-C-galactosylceramide1  

Science.gov (United States)

NKT cells respond to a variety of CD1d-restricted glycolipid antigens that are structurally related to the prototypic antigen, ?-galactosylceramide (?-GalCer). A modified analogue of ?-GalCer with a carbon-based glycosidic linkage (?-C-GalCer) has generated great interest because of its apparent ability to promote prolonged, Th1-biased immune responses. Here we report the activation of spleen NKT cells to ?-C-GalCer, and related C-glycoside ligands, is weaker than that of ?-GalCer. Furthermore, the V?8.2 and V?7 NKT TCR affinity for CD1d-?-C-GalCer, and some related analogues, is approximately 10-fold lower than that for the NKT TCR-CD1d-?-GalCer interaction. Nevertheless, the crystal structure of the V?8.2 NKT TCR-CD1d-?-C-GalCer complex is similar to that of the corresponding NKT TCR-CD1d-?-GalCer complex, although subtle differences at the interface provide a basis for understanding the lower affinity of the NKT TCR-CD1d-?-C-GalCer interaction. Our findings support the concept that for CD1d-restricted NKT cells, altered glycolipid ligands can promote markedly different responses while adopting similar TCR docking topologies.

Patel, Onisha; Cameron, Garth; Pellicci, Daniel G.; Liu, Zheng; Byun, Hoe-Sup; Beddoe, Travis; McCluskey, James; Franck, Richard W.; Castano, A. Raul; Harrak, Youssef; Llebaria, Amadeu; Bittman, Robert; Porcelli, Steven A.; Godfrey, Dale I.; Rossjohn, Jamie

2011-01-01

74

Regulation of the actin cytoskeleton by Rho kinase controls antigen presentation by CD1d1  

Science.gov (United States)

CD1d molecules are major histocompatibility complex (MHC) class I-like molecules that present lipid antigens to Natural Killer T (NKT) cells. Although we have previously shown that several different cell signaling molecules can play a role in the control of antigen presentation by CD1d, a defined mechanism by which a cell signaling pathway regulates CD1d function has been unclear. In the current study, we have found that the Rho kinases, ROCK1 and ROCK2, negatively regulate both human and mouse CD1d-mediated antigen presentation. Inhibition of ROCK pharmacologically, through specific ROCK1 and ROCK2 shRNA, or by using dendritic cells generated from ROCK1-deficient mice all resulted in enhanced CD1d-mediated antigen presentation compared to controls. ROCK regulates the actin cytoskeleton by phosphorylating LIM kinase which, in turn, phosphorylates cofilin, prohibiting actin fiber depolymerization. Treatment of antigen presenting cells with the actin filament depolymerizing agent, cytochalasin D, as well as knockdown of LIM kinase by shRNA, resulted in enhanced antigen presentation to NKT cells by CD1d, consistent with our ROCK inhibition data. Therefore, our overall results reveal a model whereby CD1d-mediated antigen presentation is negatively regulated by ROCK via its effects on the actin cytoskeleton.

Gallo, Richard M.; Khan, Masood A.; Shi, Jianjian; Kapur, Reuben; Wei, Lei; Bailey, Jennifer C.; Liu, Jianyun; Brutkiewicz, Randy R.

2012-01-01

75

1-D hybrid code for FRM dynamics  

International Nuclear Information System (INIS)

A 1-D radial hybrid code has been written to study the start-up of the FRM via neutral-beam injection. This code, named FROST (Field Reversed One-dimensional STart-up), models the plasma as azimuthal symmetric with no axial dependence. A multi-group method in energy and canonical angular momentum describes the large-orbit ions from the beam. This method is designed to be more efficient than those employing particle tracking, since the characteristic timescale of the simulation is the ion slowing down time, rather than the much shorter cyclotron period. A time-differentiated Grad-Shafranov equation couples the ion current to massless fluid equations describing electrons and low energy ions. Flux coordinates are used in this fluid model, in preference to an Eulerian framework, so that coupling of plasma at the two different radii of a closed flux surface may be treated with ease. Since a fluid treatment for electrons is invalid near a field null, a separate model for the electron current has been included for this region, a unique feature. Results of simulation of injection into a 2XIIB-like plasma are discussed. Electron currents are found to retard, but not prevent reversal of the magnetic field at the plasma center

1985-01-01

76

Relaxation of a 1-D gravitational system  

CERN Document Server

We study the relaxation towards thermodynamical equilibrium of a 1-D gravitational system. This OSC model shows a series of critical energies $E_{cn}$ where new equilibria appear and we focus on the homogeneous ($n=0$), one-peak ($n=\\pm 1$) and two-peak ($n=2$) states. Using numerical simulations we investigate the relaxation to the stable equilibrium $n=\\pm 1$ of this $N-$body system starting from initial conditions defined by equilibria $n=0$ and $n=2$. We find that in a fashion similar to other long-range systems the relaxation involves a fast violent relaxation phase followed by a slow collisional phase as the system goes through a series of quasi-stationary states. Moreover, in cases where this slow second stage leads to a dynamically unstable configuration (two peaks with a high mass ratio) it is followed by a new sequence ``violent relaxation/slow collisional relaxation''. We obtain an analytical estimate of the relaxation time $t_{2\\to \\pm 1}$ through the mean escape time of a particle from its potent...

Valageas, P

2006-01-01

77

Synthetic Seismograms in Transversely Isotropic Plane Layered Media Sismogrammes synthétiques dans les milieux stratifiés présentant une isotropie plane  

Directory of Open Access Journals (Sweden)

Full Text Available The purpose of the work presented in the paper, is to compute the response of transversely isotropic plane layered media excited by a buried or surface source, in order to obtain a method which can help interpreting real seismograms. The computation in frequency f and wavenumber k domain based on the Kennett's reflectivity method is exposed. Displacements in space and time are calculated by numerical integration (Fourier-Hankel transform) of the response in frequency and wavenumber domain. The numerical surface response of a transverse isotropic two-layered half space excited by a surface source is presented. The mechanical properties of the proposed two-layered halfspace falls within the range of marine sediments. The frequency and offset proposed domain correspond with geotechnical surveys. Effects of anisotropy are put forward by comparing the responses in anisotropic case to the responses in isotropic case. Le but des présents travaux est de calculer la réponse des milieux stratifiés présentant une isotropie plane à l'excitation d'une source enterrée ou de surface, de façon à obtenir une méthode qui puisse aider à l'interprétation des sismogrammes réels. Le calcul exposé ici, dans un domaine de fréquence f et de nombre d'onde k, est basé sur la méthode de réflexion de Kennett. Les déplacements dans l'espace et dans le temps sont calculés par une intégration numérique (transformée de Fourier-Hankel) de la réponse en fréquence et en nombre d'onde. La réponse numérique de surface d'un demi-espace à isotropie plane et à deux marqueurs excités par une source de surface est ici présentée. Les propriétés mécaniques du demi-espace proposé correspondent à celles de la gamme des sédiments marins. La fréquence et le décalage du domaine proposé correspondent à ceux employés dans la prospection géotechnique. Les effets de l'anisotropie sont mis en avant en comparant les réponses de l'exemple anisotrope à celles de l'exemple isotrope.

Guennou C.

2006-01-01

78

Synthetic seismogram modeling of crustal seismic record sections from the Koyna DSS profiles in the Western India  

Science.gov (United States)

Two deep seismic sounding profiles, each about 200 km long, were recorded in the east-west direction in the Koyna region of the Western India by the National Geophysical Research Institute CKlquiring wide angle crustal se ismic data in the analog form. The analog DSS records, acquired by continuous profiling, have been digitized and assembled into trace normalized record sections which are displayed in the form of reduced travel time with reduction velocity of 6 km/sec. Travel times and relative amplitudes modeling, with the aid of synthetic seismograms, of the record sections obtained in the eastern and western directions on the northern profile as well as a record section in the eastern direction on the southern profile reveal consistent models of the crustal velocity structure with minor lateral variations in the Koyna region. The prominent features of the crustal velocity models inferred in this region include low velocity layers (LVL) in the upper crust (6.0 to 11.5 km depth) as well as in the lower crust (26.0 to 28.0 km depth) and at least 2 km thick transitional Moho at 35.5 to 37.5 km depth. However, the Moho is 1-2 km deeper along the southern profile. The upper crustal LVL, with its top at 6-7 km depth in these models, is consistent with the observed seismic activity concentration at 4-5 km depth and an appreciable reduction of seismic activity at greater depths in the Koyna region. The inferred crustal velocity models are also consistent with the essentially aseismic nature of the lower crust in this region. The two low velocity layers, in the upper and the lower crust in th is region, may suggest rheological stratification of this part of the lithosphere with levels of increased ductility at those depths. The reflected phase PMP, from the Moho boundary, is relatively strong only beyond 90-100 km recording distance while it is almost suppressed in the subcritical distances on the record sections considered in the present study. Further the PS converted waves from the Moho are also not observable at the appropriate times in these record sections thus substantiating the transitional nature of the Moho, which is at least 2 km thick, in the Koyna region. The Pn phase, well recorded as the first arrival beyond 165 km recording distance, reveals an uppermost mantle P velocity of 8.25 km/sec in this region.

Krishna, V. G.; Kaila, K. L.; Reddy, P. R.

79

Amplitude and phase normalization of seismograms from multiple seismograph recording systems for the Yellowstone-Snake River Plain seismic refraction experiment  

Energy Technology Data Exchange (ETDEWEB)

A z transform filter theory method for the normalization of the instrument responses of several seismographs is presented. In this method, an inverse filter is derived by consideration of the seismometer/recorder characteristics which may be applied to a given seismogram to convert the system frequency response to that of a reference system. Inverse filters are derived for the seismographs used on the 1978 Yellowstone-Snake River Plain seismic profiling experiment. It is shown by application to these data that the inverse filters are effective in amplitude normalization and that their use allows improvement in the amplitude and waveform character of seismic record sections.

Baker, M.R.; Braile, L.W.; Smith, R.B.

1982-04-10

80

Axial turbomachine modelling with a 1D axisymmetric approach  

International Nuclear Information System (INIS)

[en] This work concerns the design and safety analysis of direct cycle gas cooled reactor. The estimation of compressor and turbine performances in transient operations is of high importance for the designer. The first goal of this study is to provide a description of compressor behaviour in unstable conditions with a better understanding than the models based on performance maps ('traditional' 0D approach). A supplementary objective is to provide a coherent description of the turbine behaviour. The turbomachine modelling approach consists in the solution of 1D axisymmetric Navier-Stokes equations on an axial grid inside the turbomachine: mass, axial momentum, circumferential momentum and total-enthalpy balances are written. Blade forces are taken into account by using compressor or turbine blade cascade steady correlations. A particular effort has been developed to generate or test correlations in low mass flow and negative mass flow regimes, based on experimental data. The model is tested on open literature cases of the gas turbine aircraft community. For compressor and turbine, steady situations are fairly described, especially for medium and high mass flow rate. The dynamic behaviour of compressor is also quite well described, even in unstable operation (surge): qualitative tendencies (role of plenum volume and role of throttle) and some quantitative characteristics (frequency) are in a good agreement with experimental data. The application to transient simulations of gas cooled nuclear reactors is concentrated on the hypothetical 10 in. break accident. The results point out the importance of the location of the pipe rupture in a hypothetical break event. In some detailed cases, compressor surge and back flow through the circuit can occur. In order to be used in a design phase, a simplified model of surge has also been developed. This simplified model is applied to the gas fast reactor (GFR) and compared quite favourably with 1D axisymmetric simulation results

2007-01-01

 
 
 
 
81

Propagation of compressional elastic waves through a 1-D medium with contact nonlinearities  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Propagation of monochromatic elastic waves across cracks is investigated in 1D, both theoretically and numerically. Cracks are modeled by nonlinear jump conditions. The mean dilatation of a single crack and the generation of harmonics are estimated by a perturbation analysis, and computed by the har...

Lombard, Bruno; Piraux, Joël

82

System for Digital 1D-Image Processing with 1024 Pixel CCD Sensor  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The conception of system for digital 1D-images processing with digital CCD camera is presented. The system is created from these three basic parts: the digital CCD camera with linear image sensor CCD L133C, 8-bit interface and a personal computer. The scanning digital CCD camera generated a video si...

P. Kulla; P. Sevcik; M. Chrenek; J. Misun

83

Deletion of the Phytophthora sojae avirulence gene Avr1d causes gain of virulence on Rps1d.  

UK PubMed Central (United Kingdom)

Phytophthora sojae is an oomycete and a pathogen of soybean that causes root rot. During infection P. sojae delivers effector proteins into host cells to foster disease. However, effector-triggered immunity (ETI) results when pathogen factors are recognized by host resistance (R) proteins. We have now identified the P. sojae Avr1d gene, which encodes a predicted effector protein with the amino acid motif Arg-X-Leu-Arg (RXLR). Genetic mapping of 16 different P. sojae isolates and of a segregating F2 population of 40 individuals shows that the predicted RXLR effector gene Avh6 precisely cosegregates with the Avr1d phenotype. Transient expression assays confirm that Avr1d triggers cell death specifically in Rps1d soybean plants. The Avr1d gene is present in P. sojae strains that are avirulent on Rps1d, whereas the gene is deleted from the genome of virulent strains. Two sequence variants of the Avr1d gene encoding different protein products occur in P. sojae strains, but both are recognized by Rps1d and cause ETI. Liposome binding assays show that Avr1d has affinity for phosphatidylinositol 4-phosphate and that binding can be disrupted by mutation of lysine residues in the carboxy-terminal effector domain of the protein. The identification of Avr1d aids pathogen diagnostics and soybean cultivar development.

Na R; Yu D; Qutob D; Zhao J; Gijzen M

2013-08-01

84

Analysis of the Om(1d) Locus in Drosophila Ananassae  

Digital Repository Infrastructure Vision for European Research (DRIVER)

From the ca;px stock, which is the progenitor of Om mutants caused by insertions of the tom retrotransposon, 50 kb of genomic DNA including the Om(1D) locus was cloned by tom tagging and chromosome walking. Southern blot analyses of six Om(1D) mutants exposed one or two tom elements inserted at five...

Tanda, S.; Shrimpton, A. E.; Hinton, C. W.; Langley, C. H.

85

Endoplasmic reticulum glycoprotein quality control regulates CD1d assembly and CD1d-mediated antigen presentation.  

UK PubMed Central (United Kingdom)

The non-classical major histocompatibility complex (MHC) homologue CD1d presents lipid antigens to innate-like lymphocytes called natural-killer T (NKT) cells. These cells, by virtue of their broad cytokine repertoire, shape innate and adaptive immune responses. Here, we have assessed the role of endoplasmic reticulum glycoprotein quality control in CD1d assembly and function, specifically the role of a key component of the quality control machinery, the enzyme UDP glucose glycoprotein glucosyltransferase (UGT1). We observe that in UGT1-deficient cells, CD1d associates prematurely with ?2-microglobulin (?2m) and is able to rapidly exit the endoplasmic reticulum. At least some of these CD1d-?2m heterodimers are shorter-lived and can be rescued by provision of a defined exogenous antigen, ?-galactosylceramide. Importantly, we show that in UGT1-deficient cells the CD1d-?2m heterodimers have altered antigenicity despite the fact that their cell surface levels are unchanged. We propose that UGT1 serves as a quality control checkpoint during CD1d assembly and further suggest that UGT1-mediated quality control can shape the lipid repertoire of newly synthesized CD1d. The quality control process may play a role in ensuring stability of exported CD1d-?2m complexes, in facilitating presentation of low abundance high affinity antigens, or in preventing deleterious responses to self lipids.

Kunte A; Zhang W; Paduraru C; Veerapen N; Cox LR; Besra GS; Cresswell P

2013-06-01

86

Consistent 1-D neutronics modeling using current conservation factors  

Energy Technology Data Exchange (ETDEWEB)

The 3D neutronics code is the ultimate means of achieving high fidelity in the neutronic simulation of the reactor core, nevertheless the 1D neutronic s model is needed to replace 3D model in many practical circumstances. In this paper a 3D consistent 1D model based on nonlinear analytic nodal method is developed. During the derivation, the current conservation factor (CCF) is introduced which guarantees the same axial neutron currents obtained from the 1D equation as the 3D reference values. To test the 1D model with CCF, three cases of steady state calculation were performed and compared with 3D reference values. The errors of K-eff values were reduced about one tenth when using CCF. And the errors of power distribution were decreased to the range of one fifth or tenth at steady state calculation. With the planar averaged group constants and the CCFs introduced in this paper, it becomes possible to reproduce the 3D reference solution from the 1D model. Thus the 1D model with CCF can provide the preciser results at the steady state, and it is expected that the slow transient such as the day range xenon dynamics can be simulated more accurately with 1D model.

Lee, K. B.; Joo, H. G.; Cho, B. O.; Zee, S. Q. [KAERI, Taejon (Korea, Republic of)

1999-10-01

87

Consistent 1-D neutronics modeling using current conservation factors  

International Nuclear Information System (INIS)

The 3D neutronics code is the ultimate means of achieving high fidelity in the neutronic simulation of the reactor core, nevertheless the 1D neutronic s model is needed to replace 3D model in many practical circumstances. In this paper a 3D consistent 1D model based on nonlinear analytic nodal method is developed. During the derivation, the current conservation factor (CCF) is introduced which guarantees the same axial neutron currents obtained from the 1D equation as the 3D reference values. To test the 1D model with CCF, three cases of steady state calculation were performed and compared with 3D reference values. The errors of K-eff values were reduced about one tenth when using CCF. And the errors of power distribution were decreased to the range of one fifth or tenth at steady state calculation. With the planar averaged group constants and the CCFs introduced in this paper, it becomes possible to reproduce the 3D reference solution from the 1D model. Thus the 1D model with CCF can provide the preciser results at the steady state, and it is expected that the slow transient such as the day range xenon dynamics can be simulated more accurately with 1D model.

1999-01-01

88

CD1d-lipid antigen recognition by the ?? TCR.  

UK PubMed Central (United Kingdom)

The T cell repertoire comprises ?? and ?? T cell lineages. Although it is established how ?? T cell antigen receptors (TCRs) interact with antigen presented by antigen-presenting molecules, this is unknown for ?? TCRs. We describe a population of human V?1(+) ?? T cells that exhibit autoreactivity to CD1d and provide a molecular basis for how a ?? TCR binds CD1d-?-galactosylceramide (?-GalCer). The ?? TCR docked orthogonally, over the A' pocket of CD1d, in which the V?1-chain, and in particular the germ line-encoded CDR1? loop, dominated interactions with CD1d. The TCR ?-chain sat peripherally to the interface, with the CDR3? loop representing the principal determinant for ?-GalCer specificity. Accordingly, we provide insight into how a ?? TCR binds specifically to a lipid-loaded antigen-presenting molecule.

Uldrich AP; Le Nours J; Pellicci DG; Gherardin NA; McPherson KG; Lim RT; Patel O; Beddoe T; Gras S; Rossjohn J; Godfrey DI

2013-09-01

89

New Scotogenic Model of Neutrino Mass with $U(1)_D$ Gauge Interaction  

CERN Document Server

We propose a new realization of the one-loop radiative model of neutrino mass generated by dark matter (scotogenic), where the particles in the loop have an additional $U(1)_D$ gauge symmetry, which may be exact or broken to $Z_2$. This model is relevant to a number of astrophysical observations, including AMS-02 and the dark matter distribution in dwarf galactic halos.

Ma, Ernest; Radovcic, Branimir

2013-01-01

90

Propagation of compressional elastic waves through a 1-D medium with contact nonlinearities  

CERN Multimedia

Propagation of monochromatic elastic waves across cracks is investigated in 1D, both theoretically and numerically. Cracks are modeled by nonlinear jump conditions. The mean dilatation of a single crack and the generation of harmonics are estimated by a perturbation analysis, and computed by the harmonic balance method. With a periodic and finite network of cracks, direct numerical simulations are performed and compared with Bloch-Floquet's analysis.

Lombard, Bruno

2008-01-01

91

Conventional knockout of Tbc1d1 in mice impairs insulin- and AICAR-stimulated glucose uptake in skeletal muscle.  

UK PubMed Central (United Kingdom)

In the obesity-resistant SJL mouse strain, we previously identified a naturally occurring loss-of-function mutation in the gene for Tbc1d1. Characterization of recombinant inbred mice that carried the Tbc1d1(SJL) allele on a C57BL/6J background indicated that loss of TBC1D1 protects from obesity, presumably by increasing the use of fat as energy source. To provide direct functional evidence for an involvement of TBC1D1 in energy substrate metabolism, we generated and characterized conventional Tbc1d1 knockout mice. TBC1D1-deficient mice showed moderately reduced body weight, decreased respiratory quotient and an elevated resting metabolic rate. Ex vivo analysis of intact isolated skeletal muscle revealed a severe impairment in insulin- and AICAR-stimulated glucose uptake in glycolytic extensor digitorum longus (EDL) muscle and a substantially increased rate of fatty acid oxidation in oxidative soleus muscle. Our results provide direct evidence that TBC1D1 plays a major role in glucose and lipid utilization, and energy substrate preference in skeletal muscle.

Dokas J; Chadt A; Nolden T; Himmelbauer H; Zierath JR; Joost HG; Al-Hasani H

2013-07-01

92

1D EM Modeling for Onshore Hydrocarbon Detection using MATLAB  

Directory of Open Access Journals (Sweden)

Full Text Available Controlled Source Electromagnetic (CSEM) is a new technique used for hydrocarbons detection. This study focuses on One dimension (1D) modeling of hydrocarbon detection for onshore application using the principles of electromagnetic (EM) waves propagation. The transmitted frequency which is 0.25 Hz was used to characterize the hydrocarbon at 500 m, 1000 m and 1500 m. Electric fields detected by the receivers at 500, 1000 and 1500 m were 22.85, 20.4 and 17.1 V m-1, respectively which was determined by using 1D simulation. This non-seismic 1D modeling may provide alternative solution for hydrocarbon (HC) detection for oil and gas industry.

H.M. Zaid; N.B. Yahya; M.N. Akhtar; M. Kashif; H. Daud; S. Brahim; A. Shafie; N.H.H.M. Hanif; A.A.B. Zorkepli

2011-01-01

93

Supercurrent states in 1D finite-size rings  

CERN Multimedia

We consider topological supercurrent excitations (SC) in 1D mesoscopic rings. Under certain conditions such excitations are well-defined except for (i) a tunneling between resonating states with clockwise and anti-clockwise currents, which may be characterized by the amplitude \\Delta, and (ii) a decay of SC assisted by phonons of the substrate, both effects being macroscopically small. Most attention is paid to the calculation of the macroscopic scaling of \\Delta (the main superfluid characteristic of a mesoscopic system) under different conditions: a commensurate system, a system with single impurity, and a disordered system. The results are in a very good agreement with the exact-diagonalization spectra of the boson Hubbard models. Apart from really 1D electron wires we discuss two other important experimental systems: the 2D electron gas in the FQHE state and quasi-1D superconducting rings. We suggest some experimental setups for studying SC, e.g., via persistent current measurements, resonant electro-magn...

Kashurnikov, V A; Svistunov, B V

1995-01-01

94

Hydrodynamic modes of a 1D trapped Bose gas  

CERN Multimedia

We consider two regimes where a trapped Bose gas behaves as a one-dimensional system. In the first one the Bose gas is microscopically described by 3D mean field theory, but the trap is so elongated that it behaves as a 1D gas with respect to low frequency collective modes. In the second regime we assume that the 1D gas is truly 1D and that it is properly described by the Lieb-Liniger model. In both regimes we find the frequency of the lowest compressional mode by solving the hydrodynamic equations. This is done by making use of a method which allows to find analytical or quasi-analytical solutions of these equations for a large class of models approaching very closely the actual equation of state of the Bose gas. We find an excellent agreement with the recent results of Menotti and Stringari obtained from a sum rule approach.

Fuchs, J N; Combescot, R

2003-01-01

95

The GIRAFFE Archive: 1D and 3D Spectra  

Science.gov (United States)

The GIRAFFE Archive (http://giraffe-archive.obspm.fr) contains the reduced spectra observed with the intermediate and high resolution multi-fiber spectrograph installed at VLT/UT2 (ESO). In its multi-object configuration and the different integral field unit configurations, GIRAFFE produces 1D spectra and 3D spectra. We present here the status of the archive and the different functionalities to select and download both 1D and 3D data products, as well as the present content. The two collections are available in the VO: the 1D spectra (summed in the case of integral field observations) and the 3D field observations. These latter products can be explored using the VO Paris Euro3D Client (http://voplus.obspm.fr/ chil/Euro3D).

Royer, F.; Jégouzo, I.; Tajahmady, F.; Normand, J.; Chilingarian, I.

2013-10-01

96

DOE-2 Sample Run Book, Version 2. 1D  

Energy Technology Data Exchange (ETDEWEB)

This package of updates to the DOE-2 documentation brings the previously published materials (with the exception of the Users Guide) up to Version 2.1D of the DOE-2 program. The user may verify that the program being used is 2.1D by checking the first page of the output and also the upper right hand heading of any output page of the computer printout. This document contains in concise form the basic information on all commands and keywords in the DOE-2 Building Description Language (BDL) as well as a number of supplementary tables and maps.

1989-06-01

97

Interior gradient estimate for 1-D anisotropic curvature flow  

Directory of Open Access Journals (Sweden)

Full Text Available We establish the interior gradient estimate for general 1-D anisotropic curvature flow. The estimate depends only on the height of the graph and not on the gradient at initial time. The proof relies on the monotonicity property of the number of zeros for the parabolic equation.

Yuko Nagase; Yoshihiro Tonegawa

2005-01-01

98

Polaron in a quasi 1D cylindrical quantum wire  

Directory of Open Access Journals (Sweden)

Full Text Available Polaron states in a quasi 1D cylindrical quantum wire with a parabolic confinement potential are investigated applying the Feynman variational principle. The effect of the wire radius on the polaron ground state energy level, the mass and the Fröhlich electron-phonon-coupling constant are obtained for the case of a quasi 1D cylindrical quantum wire. The effect of anisotropy of the structure on the polaron ground state energy level and the mass are also investigated. It is observed that as the wire radius tends to zero, the polaron mass and energy diverge logarithmically. The polaron mass and energy differ from the canonical strong-coupling behavior by the Fröhlich electron-phonon coupling constant and the radius of the quasi 1D cylindrical quantum wire that are expressed through a logarithmic function. Moreover, it is observed that the polaron energy and mass for strong coupling for the case of the quasi 1D cylindrical quantum wire are greater than those for bulk crystals. It is also observed that the anisotropy of the structure considerably affects both the polaron ground state energy level and the mass. It is found that as the radius of the cylindrical wire reduces, the regimes of the weak and intermediate coupling polaron shorten while the region of the strong coupling polaron broadens and extends into those of the weak and intermediate ones. Analytic expressions for the polaron ground state energy level and mass are derived for the case of strong coupling polarons.

L.C.Fai; V.Teboul; A.Monteil; S.Maabou; I.Nsangou

2005-01-01

99

Simulation of Organic Solar Cells Using AMPS-1D Program  

Directory of Open Access Journals (Sweden)

Full Text Available The analysis of microelectronic and photonic structure in one dimension program [AMPS-1D] program has been successfully used to study inorganic solar cells. In this work the program has been used to optimize the performance of the organic solar cells. The cells considered consist of poly(2-methoxy-5-(3,7- dimethyloctyloxy)-1,4-phenylenevinylene) [MDMO-PPV

Samah G. Babiker; Yong Shuai

2012-01-01

100

Quantum dynamics of $N=1$, $D=4$ supergravity compensator  

CERN Multimedia

A new $N=1$ superfield theory in $D=4$ flat superspace is suggested. It describes dynamics of supergravity compensator and can be considered as a low-energy limit for $N=1$, $D=4$ superfield supergravity. The theory is shown to be renormalizable in infrared limit and infrared free. A quantum effective action is investigated in infrared domain.

Buchbinder, I L

1996-01-01

 
 
 
 
101

Magnetic properties of d1-d1-d2 MV trimers with partial electron delocalization in the generalized vibronic model  

International Nuclear Information System (INIS)

[en] The effects of magnetic exchange, double exchange and vibronic coupling on magnetic properties of the d1-d1-d2 trimer with C2V symmetry are discussed in the generalized vibronic model. The magnetic moments are calculated with the semiclassical adiabatic approach. The results show that the PKS vibronic coupling and the P vibronic coupling favor the localization and the delocalization of the 'extra' electron, respectively. The magnetic properties are determined by the interplay among magnetic exchange, double exchange and vibronic coupling

2005-04-04

102

MineSeis -- A MATLAB{reg_sign} GUI program to calculate synthetic seismograms from a linear, multi-shot blast source model  

Energy Technology Data Exchange (ETDEWEB)

Large scale (up to 5 kt) chemical blasts are routinely conducted by mining and quarry industries around the world to remove overburden or to fragment rocks. Because of their ability to trigger the future International Monitoring System (IMS) of the Comprehensive Test Ban Treaty (CTBT), these blasts are monitored and studied by verification seismologists for the purpose of discriminating them from possible clandestine nuclear tests. One important component of these studies is the modeling of ground motions from these blasts with theoretical and empirical source models. The modeling exercises provide physical bases to regional discriminants and help to explain the observed signal characteristics. The program MineSeis has been developed to implement the synthetic seismogram modeling of multi-shot blast sources with the linear superposition of single shot sources. Single shot sources used in the modeling are the spherical explosion plus spall model mentioned here. Mueller and Murphy`s (1971) model is used as the spherical explosion model. A modification of Anandakrishnan et al.`s (1997) spall model is developed for the spall component. The program is implemented with the MATLAB{reg_sign} Graphical User Interface (GUI), providing the user with easy, interactive control of the calculation.

Yang, X.

1998-04-01

103

Effects of a descending lithospheric slab on yield estimates of Aleutian nuclear tests. Incorporation of velocity gradients in the synthesis of complete seismograms by the locked-mode method  

Energy Technology Data Exchange (ETDEWEB)

The locked mode method of synthesizing complete regional seismograms (Harvey, 1981) was modified to include the Langer uniform asymptotic approximation to vertical wave-functions within layers having linear vertical velocity gradients. Good agreement is obtained in gradient models between synthetics computed using the Langer-locked mode method, the colocation method, and the conventional locked mode method in models parameterized by thin homogeneous layers. Errors in calculated displacement introduced by the use of the Langer approximation remain less than several percent for wavelengths lambda < or = 0.2V/nabla operator V. Whenever it is necessary to represent gradients accurately, the Langer-locked mode method is computationally more efficient than the locked mode method using thin homogeneous layers. By reducing the number of parameters needed to describe an Earth model, the Langer-locked method will also simplify the inverse problem of determining structure using observed and synthetic regional seismograms. Test calculations of regional seismograms confirm that the Pn and Sn phases are strongly affected by the magnitude of the velocity gradients beneath the Moho, but that Lg is only weakly affected by the details of crustal layering.

Cormier, V.F.

1990-08-10

104

D1D5 system and noncommutative geometry  

International Nuclear Information System (INIS)

[en] Supergravity on AdS3xS3xT4 has a dual description as a conformal sigma-model with the target space being the moduli space of instantons on the noncommutative torus. We derive the precise relation between the parameters of this noncommutative torus and the parameters of the near-horizon geometry. We show that the low energy dynamics of the system of D1D5-branes wrapped on the torus of finite size is described in terms of the noncommutative geometry. As a byproduct, we give a prediction on the dependence of the moduli space of instantons on the noncommutative T4 on the metric and the noncommutativity parameter. We give a compelling evidence that the moduli space of stringy instantons on R4 with the B-field does not receive ?'-corrections. We also study the relation between the D1D5 sigma-model instantons and the supergravity instantons

2000-09-18

105

Partial breaking of N =1, D = 10 supersymmetry  

Energy Technology Data Exchange (ETDEWEB)

In this paper is described the spontaneous partial breaking of N =1, D = 10 supersymmetry to N = (1, 0), d = 6 and its dimensionally-reduced versions in the framework of nonlinear realizations. The basic Goldstone superfield is N = (1, 0), d = 6 hyper multiplet superfield satisfying a nonlinear generalization of the standard hyper multiplet constraint. It is here interpreted the generalized constraint as the manifestly world volume supersymmetric form of equations of motion of the type 1 super 5-brane in D = 10. The related issues here addressed are a possible existence of brane extension of off-shell hyper multiplet actions, the possibility to utilize vector N = (1, 0), d =6 supermultiplet as the Goldstone one, and the description of 1/4 breaking of N =1, D = 11 supersymmetry.

Bellucci, S. [Istituto Nazionale di Fisica Nucleare, Frascati, Rome (Italy). Laboratori Nazionali di Frascati; Ivanov, E.; Krivonos, S. [JINR, Bogoliubov Laboratory of Theoretical Physics, Dubna, Moscow (Russian Federation)

1999-07-01

106

Fuzzball solutions and D1-D5 microstates  

CERN Multimedia

We revisit the relation between fuzzball solutions and D1-D5 microstates. A consequence of the fact that the RR ground states (in the usual basis) are eigenstates of the R-charge is that only neutral operators can have non-vanishing expectation values on these states. We compute the holographic 1-point functions of the fuzzball solutions and find that charged chiral primaries have non-zero expectation values, except when the curve characterizing the solution is circular. The non-zero vevs reflect the fact that a generic curve breaks R-symmetry completely. This implies that fuzzball solutions (excepting circular ones) can only correspond to superpositions of RR states. We construct new solutions by appropriately superimposing fuzzball solutions that have vanishing vevs for all charged chiral primary operators and can therefore correspond to D1-D5 microstates.

Skenderis, K; Skenderis, Kostas; Taylor, Marika

2006-01-01

107

Energy balance in field reversed configurations: a 1-D model  

Energy Technology Data Exchange (ETDEWEB)

A new 1-D model is used to study the energy balance for Field Reserved Configurations (FRCs) formed in the Large s Experiment (LSX). In this 1-D model the particle and magnetic field confinement properties are not determined from first principles but included as input information that is obtained from the experiment. This reduces the number of free parameters allowing the effects of the electron thermal conduction and the influence of the edge layer confinement to be studied. Results are presented showing that with theoretically reasonable edge confinement properties the electron collisionality governing electron thermal conduction is not far (within an order of magnitude) from that governing particle diffusion properties. (author). 7 refs, 4 figs, 1 tab.

Maqueda, R.J.; Hoffman, A.L.; Steinhauer, L.C. [Washington Univ., Seattle, WA (United States). Aerospace and Energetics Research Program

1994-12-31

108

Energy balance in field reversed configurations: a 1-D model  

International Nuclear Information System (INIS)

A new 1-D model is used to study the energy balance for Field Reserved Configurations (FRCs) formed in the Large s Experiment (LSX). In this 1-D model the particle and magnetic field confinement properties are not determined from first principles but included as input information that is obtained from the experiment. This reduces the number of free parameters allowing the effects of the electron thermal conduction and the influence of the edge layer confinement to be studied. Results are presented showing that with theoretically reasonable edge confinement properties the electron collisionality governing electron thermal conduction is not far (within an order of magnitude) from that governing particle diffusion properties. (author). 7 refs, 4 figs, 1 tab

1994-11-04

109

D1-D5-P microstates at the cap  

CERN Document Server

The geometries describing D1-D5-P bound states in string theory have three regions: flat asymptotics, an anti-de Sitter throat, and a 'cap' region at the bottom of the throat. We identify the CFT description of a known class of supersymmetric D1-D5-P microstate geometries which describe degrees of freedom in the cap region. The class includes both regular solutions and solutions with conical defects, and generalizes configurations with known CFT descriptions: a parameter related to spectral flow in the CFT is generalized from integer to fractional values. We provide strong evidence for this identification by comparing the massless scalar excitation spectrum between gravity and CFT and finding exact agreement.

Giusto, Stefano; Mathur, Samir D; Turton, David

2012-01-01

110

1D Schroedinger equations with Coulomb-type potentials  

International Nuclear Information System (INIS)

We employ Laplace and Fourier transforms in momentum space to find the bound states of the 1D Schroedinger equations with two different potentials; 1/x and 1/vertical bar x vertical bar. By performing inverse transforms we show that for the potential the solutions in real space reduce to those of the 1D hydrogen atom with eigenenergies proportional to 1/n2 with n integer. Analogously, we find that for the potential 1/x the eigenenergies are proportional to 1/(n+1/2)2 and the eigenfunctions can be expressed in terms of fractional derivatives. Taking into account that both potentials are singular (the 1/x potential is analytical and the 1/vertical bar x vertical bar potential is not), we analyse the nature of their bound states. (author)

1999-03-12

111

Iron-based 1D nanostructures by electrospinning process  

International Nuclear Information System (INIS)

Iron-based 1D nanostructures have been successfully prepared using an electrospinning technique and varying the pyrolysis atmospheres. Hematite (Fe2O3) nanotubes and polycrystalline Fe3C nanofibers were obtained by simple air or mixed gas (H2, Ar) annealing treatments. Using the air annealing treatment, a high control of the morphology as well as of the wall thickness of the nanotubes was demonstrated with a direct influence of the starting polymer concentration. When mixed gases (H2 and Ar) were used for the annealing treatments, for the first time polycrystalline Fe3C nanofibers composed of carbon graphitic planes were obtained, ensuring Fe3C nanoparticle stability and nanofiber cohesion. The morphology and structural properties of all these iron-based 1D nanostructures were fully characterized by SEM, TEM, XRD and Raman spectroscopy.

1918-11-11

112

Spatial stochastic resonance in 1D Ising systems  

CERN Document Server

The 1D Ising model is analytically studied in a spatially periodic and oscillatory external magnetic field using the transfer-matrix method. For low enough magnetic field intensities the correlation between the external magnetic field and the response in magnetization presents a maximum for a given temperature. The phenomenon can be interpreted as a resonance phenomenon induced by the stochastic heatbath. This novel "spatial stochastic resonance" has a different origin from the classical stochastic resonance phenomenon.

Neda, Z; Ravasz, E; Lakdawala, P; Gade, P M

1999-01-01

113

Quantitative 1D saturation profiles on chalk by NMR.  

DEFF Research Database (Denmark)

Quantitative one-dimensional saturation profiles showing the distribution of water and oil in chalk core samples are calculated from NMR measurements utilizing a 1D CSI spectroscopy pulse sequence. Saturation profiles may be acquired under conditions of fluid flow through the sample. Results reveal that strong saturation gradients exist in chalk core samples after core floods, due to capillary effects. The method is useful in analysis of corefloods, e.g., for determination of capillary pressure functions

Olsen, Dan; Topp, Simon

1996-01-01

114

Emission from the D1D5 CFT: Higher Twists  

CERN Multimedia

We study a certain class of nonextremal D1D5 geometries and their ergoregion emission. Using a detailed CFT computation and the formalism developed in arXiv:0906.2015 [hep-th], we compute the full spectrum and rate of emission from the geometries and find exact agreement with the gravity answer. Previously, only part of the spectrum had been reproduced using a CFT description. We close with a discussion of the context and significance of the calculation.

Avery, Steven G

2009-01-01

115

Dimer impurity effect on the 1D density of states  

International Nuclear Information System (INIS)

We study the effect of a dimer impurity on the local density of states (LDOS) associated with 1D tight binding Hamiltonian. Theoretical analysis is carried out by studying the resulting three-term recursion relation corresponding to the tridiagonal representation of the system Hamiltonian. We found a closed form expression for the perturbed LDOS in terms of the unperturbed one with a pre-factor that carries information on both location and potential strength of the dimer impurity.

2010-11-01

116

Tunneling mediated by conical waves in a 1D lattice  

CERN Multimedia

The nonlinear propagation of 3D wave-packets in a 1D Bragg-induced band-gap system, shows that tranverse effects (free space diffraction) affect the interplay of periodicity and nonlinearity, leading to the spontaneous formation of fast and slow conical localized waves. Such excitation corresponds to enhanced nonlinear transmission (tunneling) in the gap, with peculiar features which differ on the two edges of the band-gap, as dictated by the full dispersion relationship of the localized waves.

Di Falco, A; Trillo, S

2007-01-01

117

1D Cahn-Hilliard equation for modulated phase systems  

Energy Technology Data Exchange (ETDEWEB)

Formation of modulated phase patterns can be modelized by a modified Cahn-Hilliard equation which includes a non-local term preventing the formation of macroscopic domains. Using stationary solutions of the original Cahn-Hilliard equation as analytical ansatzs, we compute the thermodynamically stable period of a 1D modulated phase pattern. We find that the period scales like the power -1/3 of the strength of the long-range interaction.

Villain-Guillot, Simon, E-mail: simon.villain-guillot@u-bordeaux1.f [Centre de Physique Moleculaire Optique et Hertzienne, Universite Bordeaux I, 351 cours de la Liberation 33405 Talence Cedex (France)

2010-05-21

118

1D Cahn-Hilliard equation for modulated phase systems  

Science.gov (United States)

Formation of modulated phase patterns can be modelized by a modified Cahn-Hilliard equation which includes a non-local term preventing the formation of macroscopic domains. Using stationary solutions of the original Cahn-Hilliard equation as analytical ansatzs, we compute the thermodynamically stable period of a 1D modulated phase pattern. We find that the period scales like the power -1/3 of the strength of the long-range interaction.

Villain-Guillot, Simon

2010-05-01

119

Genetic variants and mutations of PPM1D control the response to DNA damage.  

Science.gov (United States)

The Wip1 phosphatase is an oncogene that is overexpressed in a variety of primary human cancers. We were interested in identifying genetic variants that could change Wip1 activity. We identified 3 missense SNPs of the human Wip1 phosphatase, L120F, P322Q, and I496V confer a dominant-negative phenotype. On the other hand, in primary human cancers, PPM1D mutations commonly result in a gain-of-function phenotype, leading us to identify a hot-spot truncating mutation at position 525. Surprisingly, we also found a significant number of loss-of-function mutations of PPM1D in primary human cancers, both in the phosphatase domain and in the C terminus. Thus, PPM1D has evolved to generate genetic variants with lower activity, potentially providing a better fitness for the organism through suppression of multiple diseases. In cancer, however, the situation is more complex, and the presence of both activating and inhibiting mutations requires further investigation to understand their contribution to tumorigenesis. PMID:23907125

Dudgeon, Crissy; Shreeram, Sathyavageeswaran; Tanoue, Kan; Mazur, Sharlyn J; Sayadi, Ahmed; Robinson, Robert C; Appella, Ettore; Bulavin, Dmitry V

2013-07-18

120

Genetic variants and mutations of PPM1D control the response to DNA damage.  

UK PubMed Central (United Kingdom)

The Wip1 phosphatase is an oncogene that is overexpressed in a variety of primary human cancers. We were interested in identifying genetic variants that could change Wip1 activity. We identified 3 missense SNPs of the human Wip1 phosphatase, L120F, P322Q, and I496V confer a dominant-negative phenotype. On the other hand, in primary human cancers, PPM1D mutations commonly result in a gain-of-function phenotype, leading us to identify a hot-spot truncating mutation at position 525. Surprisingly, we also found a significant number of loss-of-function mutations of PPM1D in primary human cancers, both in the phosphatase domain and in the C terminus. Thus, PPM1D has evolved to generate genetic variants with lower activity, potentially providing a better fitness for the organism through suppression of multiple diseases. In cancer, however, the situation is more complex, and the presence of both activating and inhibiting mutations requires further investigation to understand their contribution to tumorigenesis.

Dudgeon C; Shreeram S; Tanoue K; Mazur SJ; Sayadi A; Robinson RC; Appella E; Bulavin DV

2013-08-01

 
 
 
 
121

Numerical simulation of Ge solar cells using D-AMPS-1D code  

International Nuclear Information System (INIS)

A solar cell is a solid state device that converts the energy of sunlight directly into electricity by the photovoltaic effect. When light with photon energies greater than the band gap is absorbed by a semiconductor material, free electrons and free holes are generated by optical excitation in the material. The main characteristic of a photovoltaic device is the presence of internal electric field able to separate the free electrons and holes so they can pass out of the material to the external circuit before they recombine. Numerical simulation of photovoltaic devices plays a crucial role in their design, performance prediction, and comprehension of the fundamental phenomena ruling their operation. The electrical transport and the optical behavior of the solar cells discussed in this work were studied with the simulation code D-AMPS-1D. This software is an updated version of the one-dimensional (1D) simulation program Analysis of Microelectronic and Photonic Devices (AMPS) that was initially developed at The Penn State University, USA. Structures such as homojunctions, heterojunctions, multijunctions, etc., resulting from stacking layers of different materials can be studied by appropriately selecting characteristic parameters. In this work, examples of cells simulation made with D-AMPS-1D are shown. Particularly, results of Ge photovoltaic devices are presented. The role of the InGaP buffer on the device was studied. Moreover, a comparison of the simulated electrical parameters with experimental results was performed.

2012-08-15

122

MARG1D: One dimensional outer region matching data code  

International Nuclear Information System (INIS)

[en] A code MARG1D has been developed which computes outer region matching data of the one dimensional Newcomb equation. Matching data play an important role in the resistive (and non ideal) Magneto-hydrodynamic (MHD) stability analysis in a tokamak plasma. The MARG1D code computes matching data by using the boundary value method or by the eigenvalue method. Variational principles are derived for the problems to be solved and a finite element method is applied. Except for the case of marginal stability, the eigenvalue method is equivalent to the boundary value method. However, the eigenvalue method has the several advantages: it is a new method of ideal MHD stability analysis for which the marginally stable state can be identified, and it guarantees numerical stability in computing matching data close to marginal stability. We perform detailed numerical experiments for a model equation with analytical solutions and for the Newcomb equation in the m=1 mode theory. Numerical experiments show that MARG1D code gives the matching data with numerical stability and high accuracy. (author)

1995-01-01

123

Enhancing Solar Cell Efficiencies through 1-D Nanostructures  

Science.gov (United States)

The current global energy problem can be attributed to insufficient fossil fuel supplies and excessive greenhouse gas emissions resulting from increasing fossil fuel consumption. The huge demand for clean energy potentially can be met by solar-to-electricity conversions. The large-scale use of solar energy is not occurring due to the high cost and inadequate efficiencies of existing solar cells. Nanostructured materials have offered new opportunities to design more efficient solar cells, particularly one-dimensional (1-D) nanomaterials for enhancing solar cell efficiencies. These 1-D nanostructures, including nanotubes, nanowires, and nanorods, offer significant opportunities to improve efficiencies of solar cells by facilitating photon absorption, electron transport, and electron collection; however, tremendous challenges must be conquered before the large-scale commercialization of such cells. This review specifically focuses on the use of 1-D nanostructures for enhancing solar cell efficiencies. Other nanostructured solar cells or solar cells based on bulk materials are not covered in this review. Major topics addressed include dye-sensitized solar cells, quantum-dot-sensitized solar cells, and p-n junction solar cells.

2009-01-01

124

Enhancing Solar Cell Efficiencies through 1-D Nanostructures  

Directory of Open Access Journals (Sweden)

Full Text Available Abstract The current global energy problem can be attributed to insufficient fossil fuel supplies and excessive greenhouse gas emissions resulting from increasing fossil fuel consumption. The huge demand for clean energy potentially can be met by solar-to-electricity conversions. The large-scale use of solar energy is not occurring due to the high cost and inadequate efficiencies of existing solar cells. Nanostructured materials have offered new opportunities to design more efficient solar cells, particularly one-dimensional (1-D) nanomaterials for enhancing solar cell efficiencies. These 1-D nanostructures, including nanotubes, nanowires, and nanorods, offer significant opportunities to improve efficiencies of solar cells by facilitating photon absorption, electron transport, and electron collection; however, tremendous challenges must be conquered before the large-scale commercialization of such cells. This review specifically focuses on the use of 1-D nanostructures for enhancing solar cell efficiencies. Other nanostructured solar cells or solar cells based on bulk materials are not covered in this review. Major topics addressed include dye-sensitized solar cells, quantum-dot-sensitized solar cells, and p-n junction solar cells.

Yu Kehan; Chen Junhong

2008-01-01

125

Mosaic PPM1D mutations are associated with predisposition to breast and ovarian cancer  

Science.gov (United States)

Improved sequencing technologies offer unprecedented opportunities for investigating the role of rare genetic variation in common disease. However, there are considerable challenges with respect to study design, data analysis and replication1. Here, using pooled next-generation sequencing of 507 genes implicated in the repair of DNA in 1,150 samples, an analytical strategy focussed on protein truncating variants (PTVs) and a large-scale sequencing case-control replication experiment in 13,642 individuals, we show that rare PTVs in the p53 inducible protein phosphatase PPM1D are associated with predisposition to breast cancer and to ovarian cancer. PPM1D PTV mutations were present in 25/7781 cases vs 1/5861 controls; P=1.12×10?5, which included 18 mutations in 6,912 individuals with breast cancer; P = 2.42×10?4 and 12 mutations in 1,121 individuals with ovarian cancer; P = 3.10×10?9. Notably, all the identified PPM1D PTVs were mosaic in lymphocyte DNA and clustered within a 370 bp region in the final exon of the gene, C-terminal to the phosphatase catalytic domain. Functional studies demonstrated that the mutations result in enhanced suppression of p53 in response to ionising radiation exposure, suggesting the mutant alleles encode hyperactive PPM1D isoforms. Thus, although the mutations cause premature protein truncation, they do not result in the simple loss-of-function typically associated with this class of variant, but instead likely have a gain-of-function effect. Our results have implications for the detection and management of breast and ovarian cancer risk. More generally, these data provide new insights into the role of rare and of mosaic genetic variants in common conditions, and the utility of sequencing in their identification.

Ruark, Elise; Snape, Katie; Humburg, Peter; Loveday, Chey; Bajrami, Ilirjana; Brough, Rachel; Rodrigues, Daniel Nava; Renwick, Anthony; Seal, Sheila; Ramsay, Emma; Duarte, Silvana Del Vecchio; Rivas, Manuel A.; Warren-Perry, Margaret; Zachariou, Anna; Campion-Flora, Adriana; Hanks, Sandra; Murray, Anne; Pour, Naser Ansari; Douglas, Jenny; Gregory, Lorna; Rimmer, Andrew; Walker, Neil M.; Yang, Tsun-Po; Adlard, Julian W.; Barwell, Julian; Berg, Jonathan; Brady, Angela F.; Brewer, Carole; Brice, Glen; Chapman, Cyril; Cook, Jackie; Davidson, Rosemarie; Donaldson, Alan; Douglas, Fiona; Eccles, Diana; Evans, D. Gareth; Greenhalgh, Lynn; Henderson, Alex; Izatt, Louise; Kumar, Ajith; Lalloo, Fiona; Miedzybrodzka, Zosia; Morrison, Patrick J.; Paterson, Joan; Porteous, Mary; Rogers, Mark T.; Shanley, Susan; Walker, Lisa; Gore, Martin; Houlston, Richard; Brown, Matthew A.; Caufield, Mark J.; Deloukas, Panagiotis; McCarthy, Mark I.; Todd, John A.; Turnbull, Clare; Reis-Filho, Jorge S.; Ashworth, Alan; Antoniou, Antonis C.; Lord, Christopher J.; Donnelly, Peter; Rahman, Nazneen

2013-01-01

126

Mosaic PPM1D mutations are associated with predisposition to breast and ovarian cancer.  

UK PubMed Central (United Kingdom)

Improved sequencing technologies offer unprecedented opportunities for investigating the role of rare genetic variation in common disease. However, there are considerable challenges with respect to study design, data analysis and replication. Using pooled next-generation sequencing of 507 genes implicated in the repair of DNA in 1,150 samples, an analytical strategy focused on protein-truncating variants (PTVs) and a large-scale sequencing case-control replication experiment in 13,642 individuals, here we show that rare PTVs in the p53-inducible protein phosphatase PPM1D are associated with predisposition to breast cancer and ovarian cancer. PPM1D PTV mutations were present in 25 out of 7,781 cases versus 1 out of 5,861 controls (P = 1.12?×?10(-5)), including 18 mutations in 6,912 individuals with breast cancer (P = 2.42?×?10(-4)) and 12 mutations in 1,121 individuals with ovarian cancer (P = 3.10?×?10(-9)). Notably, all of the identified PPM1D PTVs were mosaic in lymphocyte DNA and clustered within a 370-base-pair region in the final exon of the gene, carboxy-terminal to the phosphatase catalytic domain. Functional studies demonstrate that the mutations result in enhanced suppression of p53 in response to ionizing radiation exposure, suggesting that the mutant alleles encode hyperactive PPM1D isoforms. Thus, although the mutations cause premature protein truncation, they do not result in the simple loss-of-function effect typically associated with this class of variant, but instead probably have a gain-of-function effect. Our results have implications for the detection and management of breast and ovarian cancer risk. More generally, these data provide new insights into the role of rare and of mosaic genetic variants in common conditions, and the use of sequencing in their identification.

Ruark E; Snape K; Humburg P; Loveday C; Bajrami I; Brough R; Rodrigues DN; Renwick A; Seal S; Ramsay E; Duarte Sdel V; Rivas MA; Warren-Perry M; Zachariou A; Campion-Flora A; Hanks S; Murray A; Ansari Pour N; Douglas J; Gregory L; Rimmer A; Walker NM; Yang TP; Adlard JW; Barwell J; Berg J; Brady AF; Brewer C; Brice G; Chapman C; Cook J; Davidson R; Donaldson A; Douglas F; Eccles D; Evans DG; Greenhalgh L; Henderson A; Izatt L; Kumar A; Lalloo F; Miedzybrodzka Z; Morrison PJ; Paterson J; Porteous M; Rogers MT; Shanley S; Walker L; Gore M; Houlston R; Brown MA; Caufield MJ; Deloukas P; McCarthy MI; Todd JA; Turnbull C; Reis-Filho JS; Ashworth A; Antoniou AC; Lord CJ; Donnelly P; Rahman N

2013-01-01

127

Mosaic PPM1D mutations are associated with predisposition to breast and ovarian cancer.  

Science.gov (United States)

Improved sequencing technologies offer unprecedented opportunities for investigating the role of rare genetic variation in common disease. However, there are considerable challenges with respect to study design, data analysis and replication. Using pooled next-generation sequencing of 507 genes implicated in the repair of DNA in 1,150 samples, an analytical strategy focused on protein-truncating variants (PTVs) and a large-scale sequencing case-control replication experiment in 13,642 individuals, here we show that rare PTVs in the p53-inducible protein phosphatase PPM1D are associated with predisposition to breast cancer and ovarian cancer. PPM1D PTV mutations were present in 25 out of 7,781 cases versus 1 out of 5,861 controls (P = 1.12?×?10(-5)), including 18 mutations in 6,912 individuals with breast cancer (P = 2.42?×?10(-4)) and 12 mutations in 1,121 individuals with ovarian cancer (P = 3.10?×?10(-9)). Notably, all of the identified PPM1D PTVs were mosaic in lymphocyte DNA and clustered within a 370-base-pair region in the final exon of the gene, carboxy-terminal to the phosphatase catalytic domain. Functional studies demonstrate that the mutations result in enhanced suppression of p53 in response to ionizing radiation exposure, suggesting that the mutant alleles encode hyperactive PPM1D isoforms. Thus, although the mutations cause premature protein truncation, they do not result in the simple loss-of-function effect typically associated with this class of variant, but instead probably have a gain-of-function effect. Our results have implications for the detection and management of breast and ovarian cancer risk. More generally, these data provide new insights into the role of rare and of mosaic genetic variants in common conditions, and the use of sequencing in their identification. PMID:23242139

Ruark, Elise; Snape, Katie; Humburg, Peter; Loveday, Chey; Bajrami, Ilirjana; Brough, Rachel; Rodrigues, Daniel Nava; Renwick, Anthony; Seal, Sheila; Ramsay, Emma; Duarte, Silvana Del Vecchio; Rivas, Manuel A; Warren-Perry, Margaret; Zachariou, Anna; Campion-Flora, Adriana; Hanks, Sandra; Murray, Anne; Ansari Pour, Naser; Douglas, Jenny; Gregory, Lorna; Rimmer, Andrew; Walker, Neil M; Yang, Tsun-Po; Adlard, Julian W; Barwell, Julian; Berg, Jonathan; Brady, Angela F; Brewer, Carole; Brice, Glen; Chapman, Cyril; Cook, Jackie; Davidson, Rosemarie; Donaldson, Alan; Douglas, Fiona; Eccles, Diana; Evans, D Gareth; Greenhalgh, Lynn; Henderson, Alex; Izatt, Louise; Kumar, Ajith; Lalloo, Fiona; Miedzybrodzka, Zosia; Morrison, Patrick J; Paterson, Joan; Porteous, Mary; Rogers, Mark T; Shanley, Susan; Walker, Lisa; Gore, Martin; Houlston, Richard; Brown, Matthew A; Caufield, Mark J; Deloukas, Panagiotis; McCarthy, Mark I; Todd, John A; Turnbull, Clare; Reis-Filho, Jorge S; Ashworth, Alan; Antoniou, Antonis C; Lord, Christopher J; Donnelly, Peter; Rahman, Nazneen

2012-12-16

128

Hidden nonlinear su(22) superunitary symmetry of N=2 superextended 1D Dirac delta potential problem  

CERN Multimedia

We show that the N=2 superextended 1D quantum Dirac delta potential problem is characterized by the hidden nonlinear su(22) superunitary symmetry. The supersymmetry admits three distinct Z_2-gradings, that results in a separation of 16 integrals of motion into different sets of 8 bosonic and 8 fermionic operators generating two nonlinear, deformed forms of su(2|2), in which the Hamiltonian plays a role of a multiplicative central charge. On the ground state, the nonlinear superalgebra is reduced to the two distinct 2D Euclidean analogs of a superextended Poincare algebra used by Gershun and Tkach for investigation of spontaneous supersymmetry breaking.

Correa, Francisco; Plyushchay, Mikhail S

2008-01-01

129

Coherent Atom Optics With Fast Metastable Beams: Metastable Helium Diffraction By 1D and 2D Magnetized Reflection Gratings  

International Nuclear Information System (INIS)

[en] 1D and 2D reflection gratings (Permalloy stripes or dots deposited on silicon), immersed in an external homogeneous static magnetic field, are used to study 1D and 2D diffraction of fast metastable helium atoms He* (23S1). Both the grazing incidence used here and the repulsive potential (for sub-level m = -1) generated by the magnetisation reduce the quenching effect. This periodically structured potential is responsible for the diffraction in the incidence plane as well as for the diffraction in the perpendicular plane

2007-04-23

130

Coupling of Nod1D and HOTCHANNEL: static case; Acoplamiento de Nod1D y HOTCHANNEL: caso estatico  

Energy Technology Data Exchange (ETDEWEB)

In this work the joining of the programs Nod1D and HOTCHANNEL, developed in the National Polytechnic Institute (IPN) and in the Electrical Research Institute (IIE) respectively is described. The first one allows to study the neutronic of a nuclear reactor and the second one allows to carry out the analysis of hot channel of a Boiling Water Reactor (BWR). Nod1 D is a program that it solves by nodal methods type finite element those diffusion equations in multigroup, and it is the static part of Nod Kin that it solves the diffusion equation in their time dependent part. For another side HOTCHANNEL is based on a mathematical model constituted by four conservation equations (two of mass conservation, one of motion quantity and one of energy), which are solved applying one discretization in implicit finite differences. Both programs have been verified in independent form using diverse test problems. In this work the modifications that were necessary to carry out to both for obtaining a coupled program that it provides the axial distribution of the neutron flux, the power, the burnup and the void fraction, among others parameters as much as neutronic as thermal hydraulics are described. Those are also mentioned limitations, advantages and disadvantages of the final product to which has been designated Nod1 D-HotChn. Diverse results for the Cycle 1 of the Laguna Verde Unit 1 reactor of the Nucleo electric central comparing them with those obtained directly with the CoreMasterPresto code are provided. (Author)

Gomez T, A.M. [IPN-ESFM, 07738 Mexico D.F. (Mexico); Ovando C, R. [IIE-Gcia. de Energia Nuclear, Cuernavaca, Morelos (Mexico)]. e-mail: rovando@iie.org.mx

2003-07-01

131

The ?1D-adrenergic receptor is expressed intracellularly and coupled to increases in intracellular calcium and reactive oxygen species in human aortic smooth muscle cells  

Directory of Open Access Journals (Sweden)

Full Text Available Abstract Background The cellular localization of the ?1D-adrenergic receptor (?1D-AR) is controversial. Studies in heterologous cell systems have shown that this receptor is expressed in intracellular compartments. Other studies show that dimerization with other ARs promotes the cell surface expression of the ?1D-AR. To assess the cellular localization in vascular smooth muscle cells, we developed an adenoviral vector for the efficient expression of a GFP labeled ?1D-AR. We also measured cellular localization with immunocytochemistry. Intracellular calcium levels, measurement of reactive oxygen species and contraction of the rat aorta were used as measures of functional activity. Results The adenovirally expressed ?1D-AR was expressed in intracellular compartments in human aortic smooth muscle cells. The intracellular localization of the ?1D-AR was also demonstrated with immunocytochemistry using an ?1D-AR specific antibody. RT-PCR analysis detected mRNA transcripts corresponding to the ?1A-?1B- and ?1D-ARs in these aortic smooth muscle cells. Therefore, the presence of the other ?1-ARs, and the potential for dimerization with these receptors, does not alter the intracellular expression of the ?1D-AR. Despite the predominant intracellular localization in vascular smooth muscle cells, the ?1D-AR remained signaling competent and mediated the phenylephrine-induced increases in intracellular calcium. The ?1D-AR also was coupled to the generation of reactive oxygen species in smooth muscle cells. There is evidence from heterologous systems that the ?1D-AR heterodimerizes with the ?2-AR and that desensitization of the ?2-AR results in ?1D-AR desensitization. In the rat aorta, desensitization of the ?2-AR had no effect on contractile responses mediated by the ?1D-AR. Conclusion Our results suggest that the dimerization of the ?1D-AR with other ARs does not alter the cellular expression or functional response characteristics of the ?1D-AR.

García-Cazarín Mary L; Smith Jennifer L; Olszewski Kyle A; McCune Dan F; Simmerman Linda A; Hadley Robert W; Kraner Susan D; Piascik Michael T

2008-01-01

132

Recent advances in 5-HT1B/1D receptor antagonists and agonists and their potential therapeutic applications.  

Science.gov (United States)

The human 5-HT(1B) and 5-HT(1D) receptors are especially similar in sequence despite being encoded by two distinct genes. Although, human 5-HT(1B) and 5-HT(1D) receptors have been pharmacologically differentiated using nonselective 5-HT(1B/D) receptor antagonists such as ketanserin (1), ritanserin (2) and methiothepin (3), the precise function of these receptors remains undefined, and progress toward this has been hampered by the lack of selective ligands. The interest of the major pharmaceutical companies in 5-HT(1B/1D) antagonists increased by the discovery of potent and selective tools, combined with the fact that the blockade of terminal 5-HT(1B) receptors by selective antagonists has been proposed as a new approach for more efficient and/or fast-acting antidepressant drugs, since the acute blockade of these 5-HT autoreceptors will, in theory, immediately mimic their desensitization. Furthermore, it has been also suggested that supersensitive 5-HT(1B/1D) receptors may be involved in the pathophysiology of obsessive compulsive disorders (OCD). In the 5-HT(1B/1D) agonist field, since the discovery of sumatriptan (26) (a 5-HT(1B/1D) receptor agonist) as an effective treatment for migraine headache, intensive research in this area has led to several second-generation compounds, a few of which have either entered the market place or are in late clinical trials. Beside the antimigraine activity of the 5-HT(1B/1D) agonists in clinical evaluation or already on the market, other potential therapeutic evaluations (such as gastric motor effect, bipolar disorder, autism, anti-aggressive effects) with these drugs are being investigated. This article highlights and reviews the research advances published in the 5-HT(1B/1D) antagonist and agonist literature. The article is supplemented with selected references on the design, synthesis and development of novel 5-HT(1B/1D) agents, and on studies to understand their mechanism and pathophysiology. Emphasis is given to recent advances in the potential therapeutic applications of 5-HT(1B/1D) serotonergic agents. By no means has any attempt been made to exhaustively review the literature but rather, primary references along with citations to recent literature reviews have been included in each section. PMID:12052194

Slassi, Abdelmalik

2002-06-01

133

Investigation of the inner-outer core boundary structure from the seismograms of a deep earthquake recorded by a regional seismic array  

Science.gov (United States)

PKP(Cdiff), the PKP diffraction waves after PKP-C cut-off, was identified in the PKIKP (or PKP(DF)) wave coda of teleseismic seismograms from a deep earthquake in western Brazil. An array stacking technique was applied to the short-period waveforms from a regional seismic network in Taiwan to retrieve the weak PKP(Cdiff) waves between 159° and 162°. The differential travel times and slowness of PKP(Cdiff) and PKP(DF) were used to constrain the P-velocity structure near the inner-outer core boundary (ICB). The results of this study demonstrate that in some cases the ICB structure can be constrained by data from a single event using presently available short-period regional seismic data and applying suitable array techniques. With a correction for axi-symmetric anisotropy applied to the inner core, the results of this study agree with the PKP properties of model VMOI, a regional ICB model revised from PREM covering the ICB sampled area of this study, and model AK135, a new proposed earth model. The C-cusp position was reported at 151.4° from this event. Theoretical predictions for another new proposed earth model SP6 is in significant disagreement with the observed differential travel times between PKP(Cdiff) and PKP(DF). At a distance of 159°, the residuals (observation-prediction) included the observation errors (±0.2 sec) are approximately +0.17 sec, -0.31 sec and +0.69 sec for VMOI, AK135 and SP6, respectively. Neither model predicts a significant differential slowness residual. This misfit along this path may be the result of the lateral heterogeneity of the sampled region near the ICB relative to both spherically symmetric models or the complications imposed by the non-axi-symmetric anisotropy of the inner core.

Huang, Bor-Shouh

134

Olea europaea pollen lipids activate invariant natural killer T cells by upregulating CD1d expression on dendritic cells.  

UK PubMed Central (United Kingdom)

BACKGROUND: Invariant natural killer T (iNKT) cells recognize lipids presented by CD1d and have been implicated in the pathogenesis of allergic asthma. Recognition of plant pollen lipids by iNKT cells and their role in allergic responses are poorly defined. OBJECTIVE: Our goal was to investigate whether iNKT cells can be activated by monocyte-derived dendritic cells (DCs) exposed to lipid antigens from Olea europaea. METHODS: DCs generated in vitro were exposed to O europaea pollen grains or lipids isolated from them. Expression of lipid-presenting molecules (CD1), as well as maturation markers (HLA-DR, HLA-I, CD86, and CD80 molecules), on DCs was analyzed. iNKT cell activation after coculture with DCs was evaluated based on expansion, cytokine production, and cytotoxicity tests. RESULTS: DCs upregulated CD1d and CD86 expression and downregulated CD1a expression after exposure to a whole extract of olive pollen lipids. CD1d and CD1a were regulated at the transcriptional level in a peroxisome proliferator-activated receptor ? activation-dependent manner. Polar lipids, diacylglycerols, free fatty acids, and triacylglycerols isolated from pollen grains upregulate CD1d. The increase in CD1d expression on the DC cell surface induced by polar lipids was not regulated at the RNA level. iNKT cells efficiently recognize DCs treated with the different lipids isolated from olive pollen grains. CONCLUSIONS: Lipids from O europaea pollen upregulate CD1d and CD86 molecules on DCs, which are then able to activate iNKT cells through a CD1d-dependent pathway.

Abós-Gracia B; del Moral MG; López-Relaño J; Viana-Huete V; Castro L; Villalba M; Martínez-Naves E

2013-05-01

135

BGK electron solitary waves: 1D and 3D  

Directory of Open Access Journals (Sweden)

Full Text Available This paper presents new results for 1D BGK electron solitary wave (phase-space electron hole) solutions and, based on the new results, extends the solutions to include the 3D electrical interaction (E ~ 1/r 2) of charged particles. Our approach for extending to 3D is to solve the nonlinear 3D Poisson and 1D Vlasov equations based on a key feature of 1D electron hole (EH) solutions; the positive core of an EH is screened by electrons trapped inside the potential energy trough. This feature has not been considered in previous studies. We illustrate this key feature using an analytical model and argue that the feature is independent of any specific model. We then construct azimuthally symmetric EH solutions under conditions where electrons are highly field-aligned and ions form a uniform background along the magnetic field. Our results indicate that, for a single humped electric potential, the parallel cut of the perpendicular component of the electric field (E?) is unipolar and that of the parallel component (E||) bipolar, reproducing the multi-dimensional features of the solitary waves observed by the FAST satellite. Our analytical solutions presented in this article capture the 3D electric interaction and the observed features of (E|| ) and E?. The solutions predict a dependence of the parallel width-amplitude relation on the perpendicular size of EHs. This dependence can be used in conjunction with experimental data to yield an estimate of the typical perpendicular size of observed EHs; this provides important information on the perpendicular span of the source region as well as on how much electrostatic energy is transported by the solitary waves.

L.-J. Chen; G. K. Parks

2002-01-01

136

D1/D5 systems in N=4 string theories  

International Nuclear Information System (INIS)

We propose CFT descriptions of the D1/D5 system in a class of freely acting Z2 orbifolds/orientifolds of type IIB theory, with sixteen unbroken supercharges. The CFTs describing D1/D5 systems involve N=(4,4) or N=(4,0) sigma models on (R3xS1xT4x(T4)N/SN)/Z2, where the action of Z2 is diagonal and its precise nature depends on the model. We also discuss D1(D5)-brane states carrying non-trivial Kaluza-Klein charges, which correspond to excitations of two-dimensional CFTs of the type (R3xS1xT4)N/SNxZ2N. The resulting multiplicities for two-charge bound states are shown to agree with the predictions of U-duality. We raise a puzzle concerning the multiplicities of three-charge systems, which is generically present in all vacuum configurations with sixteen unbroken supercharges studied so far, including the more familiar type IIB on K3 case: the constraints put on BPS counting formulae by U-duality are apparently in contradiction with any CFT interpretation. We argue that the presence of RR backgrounds appearing in the symmetric product CFT may provide a resolution of this puzzle. Finally, we show that the whole tower of D-instanton corrections to certain 'BPS saturated couplings' in the low energy effective actions match with the corresponding one-loop threshold corrections on the dual fundamental string side.

2001-07-02

137

Coupling of Nod1D and HOTCHANNEL: static case  

International Nuclear Information System (INIS)

[en] In this work the joining of the programs Nod1D and HOTCHANNEL, developed in the National Polytechnic Institute (IPN) and in the Electrical Research Institute (IIE) respectively is described. The first one allows to study the neutronic of a nuclear reactor and the second one allows to carry out the analysis of hot channel of a Boiling Water Reactor (BWR). Nod1 D is a program that it solves by nodal methods type finite element those diffusion equations in multigroup, and it is the static part of Nod Kin that it solves the diffusion equation in their time dependent part. For another side HOTCHANNEL is based on a mathematical model constituted by four conservation equations (two of mass conservation, one of motion quantity and one of energy), which are solved applying one discretization in implicit finite differences. Both programs have been verified in independent form using diverse test problems. In this work the modifications that were necessary to carry out to both for obtaining a coupled program that it provides the axial distribution of the neutron flux, the power, the burnup and the void fraction, among others parameters as much as neutronic as thermal hydraulics are described. Those are also mentioned limitations, advantages and disadvantages of the final product to which has been designated Nod1 D-HotChn. Diverse results for the Cycle 1 of the Laguna Verde Unit 1 reactor of the Nucleo electric central comparing them with those obtained directly with the CoreMasterPresto code are provided. (Author)

2003-01-01

138

Investigation of reflood models by coupling REFLA-1D and multi-loop system model  

International Nuclear Information System (INIS)

[en] A system analysis code REFLA-1DS was developed by coupling reflood analysis code REFLA-1D and a multi-loop primary system model. The reflood models in the code were investigated for the development of the integral system analysis code. The REFLA-1D, which was developed with the small scale reflood experiment at JAERI, consists of one-dimensional core model and a primary system model with a constant loop resistance. The multi-loop primary system model was developed with the Cylindrical Core Test Facility of JAERI's large scale reflood tests. The components modeled in the code are the upper plenum, the steam generator, the coolant pump, the ECC injection port, the downcomer and the broken cold leg nozzle. The coupling between the two models in REFLA-1DS is accomplished by applying the equivalent flow resistance calculated with the multiloop model to the REFLA-1D. The characteristics of the code is its simplicity of the system model and the solution method which enables the fast running and the easy reflood analysis for the further model development. A fairly good agreement was obtained with the results of the Cylindrical Core Test Facility for the calculated water levels in the downcomer, the core and the upper plenum. A qualitatively good agreement was obtained concerning the parametric effects of the system pressure, the ECC flow rate and the initial clad temperature. Needs for further code improvements of the models, however, were pointed out. These include the problem concerning the generation rate of the steam and water droplets in the core in an early period, the effect of the flow oscillation on the core cooling, the heat release from the downcomer wall, and the stable system calculation. (author)

1983-01-01

139

Quantum Topology Change in (2+1)d  

CERN Multimedia

The topology of orientable (2 + 1)d spacetimes can be captured by certain lumps of non-trivial topology called topological geons. They are the topological analogues of conventional solitons. We give a description of topological geons where the degrees of freedom related to topology are separated from the complete theory that contains metric (dynamical) degrees of freedom. The formalism also allows us to investigate processes of quantum topology change. They correspond to creation and annihilation of quantum geons. Selection rules for such processes are derived.

Balachandran, A P; Costa e Silva, I P; Teotônio-Sobrinho, P

2000-01-01

140

1D models for condensation induced water hammer in pipelines  

Energy Technology Data Exchange (ETDEWEB)

Condensation induced water hammer (CIWH) are caused by contact of steam and subcooled water. Thus, modeling the direct contact condensation is a crucial step towards the simulation of condensation induced water hammer with 1D pressure surge codes. Therefore, also the TUeV NORD SysTec GmbH and Co. KG inhouse pressure surge code DYVRO has been equipped with a new contact condensation model. The validation of DYVRO against an experiment dealing with CIWH is presented in this contribution. (orig.)

Bloemeling, Frank; Neuhas, Thorsten; Schaffrath, Andreas [TUEV NORD SysTec GmbH und Co. KG, Hamburg (Germany)

2013-03-15

 
 
 
 
141

SO(1,d+1) Racah coefficients: Type I Representations  

CERN Document Server

We use AdS/CFT inspired methods to study the Lorentz group SO(1,d+1) Racah coefficients for type I representations. For such representations the Racah coefficient can be represented as an integral of a product of 6 bulk-to-bulk propagators over 4 copies of the hyperbolic space H_{d+1}. To compute the integrals we represent the bulk-to-bulk propagators in terms of bulk-to-boundary ones. The bulk integrals can be computed explicitly, and the boundary integrations are carried out by introducing Feynman parameters. The final result is an integral representation of the Racah coefficient given by 4 Barnes-Mellin type integrals.

Krasnov, K V; Krasnov, Kirill; Louko, Jorma

2005-01-01

142

1D modeling on the material balance in CFB boiler  

Energy Technology Data Exchange (ETDEWEB)

An 1D model of the circulating fluidized bed (CFB) boiler is developed specifically to predict the material balance in CFB boiler. This model emphasizes on the important factors that influence the ash balance in CFB boilers, such as ash formation, attrition and size reduction, residence time and segregation in dense bed. The corresponding sub-models are discussed in detail. In the simulation of a 135MWe CFB boiler in Zibo power plant, China, the parameters in mass balance model under full load operation, such as segregation parameters and axial decay constant, are optimized. The model can predict the mass balances at different operating loads in the same boiler.

Hairui Yang; Guangxi Yue; Xianbin Xiao; Junfu Lu; Qing Liu [Tsinghua University, Beijing (China). Department of Thermal Engineering

2005-10-15

143

Exotic prepotentials from D(-1)D7 dynamics  

International Nuclear Information System (INIS)

We compute the partition functions of D(-1)D7 systems describing the multi-instanton dynamics of SO(N) gauge theories in eight dimensions. This is the simplest instance of the so called exotic instantons. In analogy with the Seiberg-Witten theory in four space-time dimensions, the prepotential and correlators in the chiral ring are derived via localization formulas and found to satisfy relations of the Matone type. Exotic prepotentials of SO(N) gauge theories with N = 2 supersymmetries in four-dimensions are also discussed.

2009-01-01

144

Observation and analysis of the 2g(1D) ion-pair state of I2: the g/u mixing between the 1u(1D) and 2g(1D) states.  

UK PubMed Central (United Kingdom)

We report the analysis of the 2g(1D) ion-pair state of I2 by perturbation-facilitated optical-optical double resonance. The present study began with the observation of the 2g(1D)-A' 3Pi(2u) emission at around 230 nm during the analysis of the ultraviolet emissions originating form the 1u(1D) ion-pair state. The identification of this new transition helped us to specify the wavelengths for detecting the 2g(1D) state by emission, and also to estimate its absolute position. The intermediate states used to observe the 2g(1D) state were the B 3Pi(0u(+))-b' 2u mixed states by the hyperfine interaction, which allowed us to combine the X 1Sigmag(+) ground state with the 2g(1D) state in the (1+1) photon excitation following the optical selection rules for one-photon transitions: 2g(1D)<--b' 2u-B 3Pi(0u(+))<--X 1Sigmag(+). Our analysis covered the 2g(1D) state in the 0< or =v< or =12 and 9< or =J< or =40 ranges. The molecular constants and Rydberg-Klein-Rees (RKR) potential of the 2g(1D) state were reported. We discussed the occurrence of the 2g(1D)-A' 3Pi(2u) emission, when exciting to the 1u(1D) v=0 state, and attributed it to the g/u mixing between the 2g(1D) and 1u(1D) states by the hyperfine interaction. The effect of the perturbation on measured line intensities and lifetimes was evident.

Nakano Y; Ukeguchi H; Ishiwata T

2004-07-01

145

Transient pressure characteristics in a pressure regulating system by using 1-D analytic valve modeling  

International Nuclear Information System (INIS)

[en] Typically, a Pressure Control Valve (PCV) system is constructed with 3 to 4 PCV lines in order to prepare for both a future demand increase and a continuous supply of power after an emergency shutdown of the operating line. However, some operation failure cases that do not follow the original design concepts of a PCV system have been reported in the field. In this study, an accurate 1-D PCV system numerical model was built and a 1-D compressible flow theory was introduced for analytic valve modeling to find solutions for this problem. Several numerical analyses were successfully performed to examine the generation and propagation characteristics of the transient pressure and to clarify the relationships between the transient pressure or surge wave and each factor or parameter relating to fluid dynamics behavior in a PCV system. The relationship between the transient pressure and other factors, such as the size of pipe and header linked after a PCV, the pipe size of the added components linked after the header, and the generation time of the transient pressure and influence of the Slam Shut Valve were investigated in detail. Finally, in order to reduce the strength of the transient pressure and to delay its propagation, this study demonstrates the benefit both of enlargement of the pipe linked to the component added after the PCV system, and the installation of a dissipation component between the operation line and the other lines

2008-01-01

146

Local structure study of vanadium pentoxide 1D-nanostructures  

International Nuclear Information System (INIS)

Vanadium pentoxide (V2O5·nH2O) 1D-nanostructures as nanowires and nanorods have been obtained by decomposition of vanadium peroxide in hydrothermal conditions. Electron microscopy, Raman spectroscopy, and X-ray absorption spectroscopy (XAS) were employed to characterize the morphology and the local structure of as-obtained samples. Scanning transmission electron microscopy (STEM) revealed that the diameter of the nanowires and nanorods were found to be 10–20 and 30–40 nm, respectively. The results demonstrated that a combination of Raman and XAS techniques allowed the accurate characterization of the local structure of V2O5 1D-nanostructures which are related to different morphologies. Analyses of X-ray absorption near-edge structure (XANES) and extended X-ray absorption fine structure (EXAFS) spectra reveals that the local structure of V in the as-obtained samples is similar to the bulk V2O5 (in orthorhombic phase), except for a higher degree of local symmetry within the structure of the VO5 square pyramid. Additionally, the nanostructures prepared by this technique present a single crystalline nature and could emit visible light at room temperature which is related to the local order of V atoms of the studied samples.

2011-01-01

147

Eddy current model for 1D magnetic bearing simulations  

Energy Technology Data Exchange (ETDEWEB)

Eddy current induced phase lag of the B field within a magnetic bearing gap is known to affect both stability and power dissipation. This component of the gap`s field arises from the 2D or 3D motion of stator or rotor surface currents. This phenomenon is often quite complex requiring solution of Maxwell`s equations along with the constitutive relations. Magnetic bearings are frequently designed by employing 1D magnetic circuit analysis representing coils and permanent magnets as Sources and reluctance as resistors. Test data shows that this may be inadequate since it does not explain the frequency dependence of B amplitudes and the occurrence of phase lags. The present research aims to provide guidance for incorporating eddy current lag in a 1D magnetic circuit model. Although the results are derived for specific bearings, the procedure and qualitative effects may be utilized for other geometries. The magnetic bearing designer may implement these and the additional results provided in the paper to derive a conservative design. The results in the paper are based on 4 magnetic bearings: (a) Radial, homopolar I (test data). (b) Radial, homopolar (finite element model). (c) Axial (test data).

Kim, C.; Palazzolo, A. [Texas A& M Univ., College Station, TX (United States); Kascak, A.; Brown, G.; Provenza, A.; Montague, G.

1995-12-31

148

1-D DCT Using Latency Efficient Floating Point Algorithms  

Directory of Open Access Journals (Sweden)

Full Text Available This paper presents the design of one-dimensional discrete cosine transform (DCT) architecture for digital signal processing (DSP) applications. DCT is a basic transformation for coding method which converts spatial domain to frequency domain of image. In 1-D DCT operation addition, subtraction, multiplication operations are required. These operations must be accurate, less latency. Floating point operations have dynamic range of representation, more accurate and perform millions of calculations per second. So the floating point operations are used for the above operations. In this floating point adder/subtractor is the most complex operation in a floating-point arithmetic and consists of many variable latency- and area dependent sub-operations. In floating-point addition implementations, latency is the primary performance bottleneck. So different types of floating point adder/subtractor algorithms such as LOD, LOP, Two-path are used to decrease the latency. The trade off is observed in 1-D DCT by changing different types of adders in place of summer. All architectures are designed and implemented using VHDL using Xillinx 13.1software.

Viswanath Gowd A, Yedukondala Rao V, T. Shanmuganantham

2013-01-01

149

Evidence for 5-HT1D beta but not 5-HT1D alpha receptor subtype expression in canine large coronary arteries and saphenous vein.  

UK PubMed Central (United Kingdom)

OBJECTIVE: 5-Hydroxytryptamine1D (5-HT1D) receptors are believed to play a major role in the vasoconstriction of vascular smooth muscle in human coronary arteries. However, unequivocal evidence as to which subtype of this receptor (5-HT1D alpha or 5-HT1D beta) is involved in these vasoconstrictory effects is lacking. The aim of this study was to identify in the dog the 5-HT1D receptor subtype encoding mRNAs expressed in several large coronary arteries and in the saphenous vein. METHODS: Degenerate oligonucleotide primers that selectively recognized only mammalian 5-HT1D alpha and 5-HT1D beta receptor sequences were used in RT-PCR experiments to study 5-HT1D receptor subtype expression in endothelium-denuded saphenous vein and large coronary arteries from beagle and alsatian dogs. Resulting PCR products were analysed and identified by Southern blots and sequencing. RESULTS: An identical PCR product whose sequence closely resembles that of the human 5-HT1D beta receptor (98% amino acid identity) was obtained from reverse-transcribed RNA isolated from either saphenous vein or coronary arteries, irrespective of dog race. Absence of 5-HT1D alpha expression was confirmed by Southern blot analysis. Control experiments using canine genomic DNA as template illustrated, nonetheless, that the primers chosen could amplify both 5-HT1D alpha and 5-HT1D beta sequences. CONCLUSION: Using RT-PCR, we isolated from dog vascular smooth muscle a cDNA fragment whose nucleotide sequence would encode a previously-unreported canine homologue of the 5-HT1D beta receptor. We illustrated that this subtype is the only 5-HT1D receptor subtype expressed in dog saphenous vein and large coronary arteries. The implications of these findings are discussed in light of results from functional studies of 5-HT1-like receptor-mediated effects in these canine blood vessels.

Sgard F; Faure C; Graham D

1996-05-01

150

Pharmacological characterizations of recombinant human 5-HT1D alpha and 5-HT1D beta receptor subtypes coupled to adenylate cyclase inhibition in clonal cell lines: apparent differences in drug intrinsic efficacies between human 5-HT1D subtypes.  

Science.gov (United States)

Recombinant human 5-HT1D alpha and 5-HT1D beta receptor subtypes were stably expressed in NIH-3T3 fibroblasts (1D alpha cell line) and Y-1 adrenocortical tumor cells (1D beta cell line), respectively, for pharmacological evaluations of serotonergic compounds to inhibit forskolin-stimulated cAMP accumulation (FSCA). [3H]LSD saturation studies indicated that 5-HT1D receptor expression levels were slightly higher in the 1D beta cell line (Bmax = 1334 +/- 134 fmol/mg protein) than in the 1D alpha cell line (Bmax = 900 +/- 218 fmol/mg protein). 5-HT inhibited FSCA with similar potencies (EC50 approximately 2 nM) in both assay systems. The rank order of agonist potencies in both clonal cell lines matched their pharmacological profiles previously determined in binding studies: dihydroergotamine > or = 5-carboxamidotryptamine (5-CT) > LSD > or = 5-HT > sumatriptan > 1-naphthylpiperazine (1-NP) > yohimbine > 8-hydroxy-2-(di-n-propylamino)tetralin (8-OH DPAT) > 1-(2,5-dimethoxy-4-iodophenyl)-2-aminopropane (DOI), with Ki/EC50 ratios greater than unity. Methiothepin acted as a silent antagonist at both human 5-HT1D alpha and 5-HT1D beta receptors with apparent dissociation constants (Kb values) of 12 +/- 1 nM and 3 +/- 1 nM, respectively. Whereas GR 127,935, metergoline, DOI, and quipazine acted as full agonists in the 1D alpha cell line, these compounds behaved as partial agonists in the 1D beta cell line. To determine whether high levels of receptor reserve might mask partial agonist activity in the two second messenger assay systems, studies were performed using the irreversible receptor alkylating agent N-ethoxycarbonyl-2-ethoxy-1,2-dihydroquinoline (EEDQ). The relationships between receptor occupancy and inhibition of FSCA were determined for 5-HT, sumatriptan, and 1-NP in both clonal cell lines after partial receptor inactivation using Furchgott analysis. Hyperbolic relationships between receptor occupancy and second messenger response were determined for 5-HT in both transfected cell lines. Steep hyperbolic relationships were also found for sumatriptan and 1-NP in the 1D beta cell line whereas nearly linear relationships were observed for these two compounds in the 1D alpha cell line. Moreover, KA/EC50 ratios of these compounds were significantly larger in the 1D beta (10-32) as compared to the 1D alpha (0.9-2.5) cell line. These data are consistent with the hypothesis that the two heterologous expression systems contain a differential amount of receptor reserve. Despite the presence of an apparently larger-receptor reserve in the 1D beta cell line, GR 127,935, metergoline, DOI, and quipazine behaved as partial agonists. Although the potencies (EC50 values) of compounds matched their respective affinity constants (Ki values) for the closely-related 5-HT1D subtypes, differences in intrinsic activities were observed for a few compounds between the two 5-HT1D receptor expression systems. Since receptor reserve is dependent on the properties of both the assay system and drug, the observed variations in intrinsic activity, although influenced by the variable amounts of receptor reserve in the two transfected cell lines, reflect primarily system-independent differences in the intrinsic efficacy of the tested compounds at the two human 5-HT1D receptors. Higher intrinsic efficacies of compounds at the human 5-HT1D alpha receptor relative to the human 5-HT1D beta subtype may be responsible for the higher intrinsic activities observed in the 1D alpha cell line, even though receptor reserve is apparently lower in this system. PMID:8878051

Zgombick, J M; Schechter, L E; Adham, N; Kucharewicz, S A; Weinshank, R L; Branchek, T A

151

Pharmacological characterizations of recombinant human 5-HT1D alpha and 5-HT1D beta receptor subtypes coupled to adenylate cyclase inhibition in clonal cell lines: apparent differences in drug intrinsic efficacies between human 5-HT1D subtypes.  

UK PubMed Central (United Kingdom)

Recombinant human 5-HT1D alpha and 5-HT1D beta receptor subtypes were stably expressed in NIH-3T3 fibroblasts (1D alpha cell line) and Y-1 adrenocortical tumor cells (1D beta cell line), respectively, for pharmacological evaluations of serotonergic compounds to inhibit forskolin-stimulated cAMP accumulation (FSCA). [3H]LSD saturation studies indicated that 5-HT1D receptor expression levels were slightly higher in the 1D beta cell line (Bmax = 1334 +/- 134 fmol/mg protein) than in the 1D alpha cell line (Bmax = 900 +/- 218 fmol/mg protein). 5-HT inhibited FSCA with similar potencies (EC50 approximately 2 nM) in both assay systems. The rank order of agonist potencies in both clonal cell lines matched their pharmacological profiles previously determined in binding studies: dihydroergotamine > or = 5-carboxamidotryptamine (5-CT) > LSD > or = 5-HT > sumatriptan > 1-naphthylpiperazine (1-NP) > yohimbine > 8-hydroxy-2-(di-n-propylamino)tetralin (8-OH DPAT) > 1-(2,5-dimethoxy-4-iodophenyl)-2-aminopropane (DOI), with Ki/EC50 ratios greater than unity. Methiothepin acted as a silent antagonist at both human 5-HT1D alpha and 5-HT1D beta receptors with apparent dissociation constants (Kb values) of 12 +/- 1 nM and 3 +/- 1 nM, respectively. Whereas GR 127,935, metergoline, DOI, and quipazine acted as full agonists in the 1D alpha cell line, these compounds behaved as partial agonists in the 1D beta cell line. To determine whether high levels of receptor reserve might mask partial agonist activity in the two second messenger assay systems, studies were performed using the irreversible receptor alkylating agent N-ethoxycarbonyl-2-ethoxy-1,2-dihydroquinoline (EEDQ). The relationships between receptor occupancy and inhibition of FSCA were determined for 5-HT, sumatriptan, and 1-NP in both clonal cell lines after partial receptor inactivation using Furchgott analysis. Hyperbolic relationships between receptor occupancy and second messenger response were determined for 5-HT in both transfected cell lines. Steep hyperbolic relationships were also found for sumatriptan and 1-NP in the 1D beta cell line whereas nearly linear relationships were observed for these two compounds in the 1D alpha cell line. Moreover, KA/EC50 ratios of these compounds were significantly larger in the 1D beta (10-32) as compared to the 1D alpha (0.9-2.5) cell line. These data are consistent with the hypothesis that the two heterologous expression systems contain a differential amount of receptor reserve. Despite the presence of an apparently larger-receptor reserve in the 1D beta cell line, GR 127,935, metergoline, DOI, and quipazine behaved as partial agonists. Although the potencies (EC50 values) of compounds matched their respective affinity constants (Ki values) for the closely-related 5-HT1D subtypes, differences in intrinsic activities were observed for a few compounds between the two 5-HT1D receptor expression systems. Since receptor reserve is dependent on the properties of both the assay system and drug, the observed variations in intrinsic activity, although influenced by the variable amounts of receptor reserve in the two transfected cell lines, reflect primarily system-independent differences in the intrinsic efficacy of the tested compounds at the two human 5-HT1D receptors. Higher intrinsic efficacies of compounds at the human 5-HT1D alpha receptor relative to the human 5-HT1D beta subtype may be responsible for the higher intrinsic activities observed in the 1D alpha cell line, even though receptor reserve is apparently lower in this system.

Zgombick JM; Schechter LE; Adham N; Kucharewicz SA; Weinshank RL; Branchek TA

1996-08-01

152

MX chains: 1-D analog of CuO planes?  

International Nuclear Information System (INIS)

[en] We study a two-band Peierls-Hubbard model for halogen-bridged mixed-valence transition metal linear chain complexes (MX chains). We include electron-electron correlations (both Hubbard and PPP-like expressions) using several techniques including calculations in the zero-hopping limit, exact diagonalization of small systems, mean field approximation, and a Gutzwiller-like Ansatz for quantum phonons. The adiabatic optical absorption and phonon spectra for both photo-excited and doping induced defects (kinks, polarons, bipolarons, and excitons) are discussed. A long period phase which occurs even at commensurate filling for certain parameter values may be related to twinning. The effect of including the electron-phonon in addition to the electron-electron interaction on the polaron/bipolaron (pairing) competition is especially interesting when this class of compounds is viewed as a 1-D analog of high-temperature superconductors. 6 refs., 4 figs

1989-01-01

153

Effective slip boundary conditions for 1D periodic surfaces  

CERN Document Server

In many applications it is advantageous to construct effective slip boundary conditions, which could fully characterize flow over patterned surfaces. Here we focus on laminar shear flows over smooth anisotropic surfaces with arbitrary periodic scalar slip $b(y)$, varying in only one direction. We derive general expressions for longitudinal and transverse components of the effective slip-length tensor, and show that they are affine being related by a simple formula \\[ b_{\\mathrm{eff}}^{\\bot}[b(y)/L] =\\frac{b_{\\mathrm{eff}%}^{\\parallel}[2b(y)/L]}{2}. \\] A remarkable corollary of this relation is that the flow along any direction of the 1D surface can be easily determined, once the longitudinal component of the effective slip tensor is found from the known spatially nonuniform scalar slip.

Asmolov, Evgeny S

2012-01-01

154

Synthesis and structural characterization of 1-(D-glycosyloxy)phthalazines.  

Science.gov (United States)

Coupling of the trimethylsilyl derivative of (2H)phthalazin-1-one with 1,2,3,4,6-penta-O-acetyl-alpha-D-glucopyranose and 1,2,3,4,6-penta-O-acetyl-alpha-D-galactopyranose in the presence of stannic chloride gave the respective glycosides, 2-(per-O-acetyl-D-glycosyloxy)phthalazines, which upon deacetylation gave the respective unprotected analogues. Under the same conditions 1,2,3,5-tetra-O-acetyl-beta-D-ribofuranose gave 1-(2,3,5-tri-O-acetyl-alpha-D-ribofuranosyloxy)phthalazine. Electrospray mass spectrometry aided the structural characterization of this series of 1-(D-glycosylyloxy)phthalazines. Low energy collisionally-induced dissociation tandem mass spectrometry of the protonated molecules confirmed the MS fragmentation routes and the structural identities of this novel series of glycosides. PMID:14572713

Haikal, Abdellfattah Z; El Ashry, El Sayed H; Banoub, Joseph

2003-10-31

155

1-D array of perforated diode neutron detectors  

International Nuclear Information System (INIS)

[en] Performance of a 4 cm long 64-pixel perforated diode neutron detector array is compared with an identical array of thin-film coated diodes. The perforated neutron detector design has been adapted to a 1-D pixel array capable of 120 ?m spatial resolution and counting efficiency greater than 12%. Deep vertical trenches filled with 6LiF provide outstanding improvement in efficiency over thin-film coated diode designs limited to only 4.5%. This work marks the final step towards the construction of a much larger array consisting of 1024 pixels spanning 10 cm. The larger detector array will be constructed with a sub-array of 64-pixel sensors, and will be used for small-angle neutron scattering experiments at the Spallation Neutron Source of Oak Ridge National Laboratory.

2009-06-01

156

1-D array of perforated diode neutron detectors  

Energy Technology Data Exchange (ETDEWEB)

Performance of a 4 cm long 64-pixel perforated diode neutron detector array is compared with an identical array of thin-film coated diodes. The perforated neutron detector design has been adapted to a 1-D pixel array capable of 120 {mu}m spatial resolution and counting efficiency greater than 12%. Deep vertical trenches filled with {sup 6}LiF provide outstanding improvement in efficiency over thin-film coated diode designs limited to only 4.5%. This work marks the final step towards the construction of a much larger array consisting of 1024 pixels spanning 10 cm. The larger detector array will be constructed with a sub-array of 64-pixel sensors, and will be used for small-angle neutron scattering experiments at the Spallation Neutron Source of Oak Ridge National Laboratory.

McNeil, Walter J. [Kansas State University, Mechanical and Nuclear Engineering Department, Manhattan, KS 66506 (United States)], E-mail: wjm4444@ksu.edu; Bellinger, Steven L.; Unruh, Troy C.; Henderson, Chris M.; Ugorowski, Phil; Morris-Lee, Bryce [Kansas State University, Mechanical and Nuclear Engineering Department, Manhattan, KS 66506 (United States); Taylor, Russell D. [Electronics Design Laboratory, Kansas State University, Manhattan, KS 66506 (United States); McGregor, Douglas S. [Kansas State University, Mechanical and Nuclear Engineering Department, Manhattan, KS 66506 (United States)], E-mail: mcgregor@ksu.edu

2009-06-01

157

Robust recognition of 1D barcodes using Hough transform  

Science.gov (United States)

In this paper we present an algorithm for the recognition of 1D barcodes using the Hough transform, which is highly robust regarding the typical degraded image. The algorithm addresses various typical image distortions, such as inhomogeneous illumination, reflections, damaged barcode or blurriness etc. Other problems arise from recognizing low quality printing (low contrast or poor ink receptivity). Traditional approaches are unable to provide a fast solution for handling such complex and mixed noise factors. A multi-level method offers a better approach to best manage competing constraints of complex noise and fast decode. At the lowest level, images are processed in gray scale. At the middle level, the image is transformed into the Hough domain. At the top level, global results, including missing information, is processed within a global context including domain heuristics as well as OCR. The three levels work closely together by passing information up and down between levels.

Dwinell, John; Bian, Peng; Bian, Long Xiang

2012-02-01

158

A 1-D model for highly sensitive tubular reactors  

Energy Technology Data Exchange (ETDEWEB)

We consider the steady state operation of wall-cooled, fixed-bed tubular reactors. In these reactors the temperature rise ..delta..T must normally be limited to small fractions of the adiabatic temperature rise ..delta..T/sub ad/, both to avoid runaway and maintain product selectivity. Yet ..delta..T/..delta..T/sub ad/ << 1 can only occur if eta = t/sub dif//t/sub reac/ << 1, where t/sub dif/ is the timescale on which heat escapes the reactor by ''diffusing'' to the cooled walls, and t/sub reac/ is the timescale over which the reaction occurs. So here we use asymptotic methods based on eta << 1 to analyze the 2-d reactor equations, and find the radial concentration and temperature profiles to leading order in eta. We then obtain a 1-d model of the reactor by substituting these asymptotically correct profiles into the reactor equations and averaging over r. This model, the ..cap alpha..-model, is identical to the standard (Beek and Singer) 1-d model, except that the reactor's overall heat transfer coefficient U is a decreasing function of the temperature rise ..delta..T. This occurs because as ..delta..T increases, the reaction becomes increasingly concentrated near r = 0, causing a decreased heat transfer efficiency through the reactor's walls. By comparing it with numerical solutions of the original 2-d reactor equations, we find that the ..cap alpha..-model simulates the 2-d equations very accurately, even for highly sensitive reactors operated near runaway. We also find that a runaway criterion derived from the ..cap alpha..-model predicts the runaway transition of the original 2-d equations accurately, especially for highly sensitive reactors. 19 refs.

Hagan, P.S.; Herskowitz, M.; Pirkle, J.C.

1987-01-01

159

Global Control Methods for GHZ State Generation on 1-D Ising Chain  

CERN Document Server

We discuss how to prepare an Ising chain in a GHZ state using a single global control field only. This model does not require the spins to be individually addressable and is applicable to quantum systems such as cold atoms in optical lattices, some liquid- or solid-state NMR experiments, and many nano-scale quantum structures. We show that GHZ states can always be reached asymptotically from certain easy-to-prepare initial states using adiabatic passage, and under certain conditions finite-time reachability can be ensured. To provide a reference useful for future experimental implementations three different control strategies to achieve the objective, adiabatic passage, Lyapunov control and optimal control are compared, and their advantages and disadvantages discussed, in particular in the presence of realistic imperfections such as imperfect initial state preparation, system inhomogeneity and dephasing.

Wang, Xiaoting; Bose, Sougato; Schirmer, Sophie

2010-01-01

160

Ex vivo analysis of resident hepatic pro-inflammatory CD1d-reactive T cells and hepatocyte surface CD1d expression in hepatitis C.  

UK PubMed Central (United Kingdom)

Hepatic CD1d-restricted and natural killer T-cell populations are heterogeneous. Classical 'type 1' ?-galactosylceramide-reactive CD1d-restricted T cells express 'invariant' TCR? ('iNKT'). iNKT dominating rodent liver are implicated in inflammation, including in hepatitis models. Low levels of iNKT are detected in human liver, decreased in subjects with chronic hepatitis C (CHC). However, high levels of human hepatic CD161(±) CD56(±) noninvariant pro-inflammatory CD1d-restricted 'type 2' T cells have been identified in vitro. Unlike rodents, healthy human hepatocytes only express trace and intracellular CD1d. Total hepatic CD1d appears to be increased in CHC and primary biliary cirrhosis. Direct ex vivo analysis of human intrahepatic lymphocytes (IHL), including matched ex vivo versus in vitro expanded IHL, demonstrated detectable noninvariant CD1d reactivity in substantial proportions of HCV-positive livers and significant fractions of HCV-negative livers. However, ?-galactosylceramide-reactive iNKT were detected only relatively rarely. Liver CD1d-restricted IHL produced IFN?, variable levels of IL-10 and modest levels of Th2 cytokines IL-4 and IL-13 ex vivo. In a novel FACS assay, a major fraction (10-20%) of hepatic T cells rapidly produced IFN? and up-regulated activation marker CD69 in response to CD1d. As previously only shown with murine iNKT, noninvariant human CD1d-specific responses were also augmented by IL-12. Interestingly, CD1d was found selectively expressed on the surface of hepatocytes in CHC, but not those CHC subjects with history of alcohol usage or resolved CHC. In contrast to hepatic iNKT, noninvariant IFN?-producing type 2 CD1d-reactive NKT cells are commonly detected in CHC, together with cognate ligand CD1d, implicating them in CHC liver damage.

Yanagisawa K; Yue S; van der Vliet HJ; Wang R; Alatrakchi N; Golden-Mason L; Schuppan D; Koziel MJ; Rosen HR; Exley MA

2013-08-01

 
 
 
 
161

Crossed molecular beams study of O({sup 1}D) reactions with H{sub 2} molecules  

Energy Technology Data Exchange (ETDEWEB)

Reaction dynamics of O({sup 1}D) atoms with H{sub 2} molecules was reinvestigated using the crossed molecular beams technique with pulsed beams. The O({sup 1}D) beam was generated by photodissociating O{sub 3} molecules at 248 nm. Time-of-flight spectra and the laboratory angular distribution of the OH products were measured. The derived OH product center-of-mass flux-velocity contour diagram shows more backward scattered intensity with respect to the O({sup 1}D) beam. In contrast to previous studies which show that the insertion mechanism is the dominant process, our results indicate that the contribution from the collinear approach of the O({sup 1}D) atom to the H{sub 2} molecule on the first excited state potential energy surface is significant and the energy barrier for the collinear approach is therefore minimal. Despite the increased time resolution in this experiment, no vibrational structure in the OH product time-of-flight spectra was resolved. This is in agreement with LIF studies, which have shown that the rotational distributions of the OH products in all vibrational states are broad and highly inverted.

Miau, T.T.

1995-05-01

162

Electrodeposition of photoactive 1D gallium selenide quantum dots  

International Nuclear Information System (INIS)

One-dimensional (1D) quantum dots of gallium selenide have been obtained by cathodic electrodeposition onto the tin doped indium oxide (ITO) glass substrates from aqueous acidic solutions at room temperature. Characterizations of the as-deposited films by energy dispersive X-ray (EDX) spectroscopy confirm a selenium rich chemistry, X-ray diffraction (XRD) shows that mixture of phases like GaSe/Ga2Se3, and optical spectroscopy shows a direct optical band gap of 2.85 eV with intermediate transition energy at 1.9 eV. From transmission electron microscopy (TEM), the films show the one-dimensional quantum dots chains in grains. Scanning electron microscopy (SEM) images indicate dimorphous placement of nanoparticles. The elementals surface analysis of the core-shell nanoparticles determined by X-ray photoelectron spectroscopy (XPS) supported the EDX results and confirmed the chemical nature of the material. The photoelectrochemical (PEC) studies of gallium selenide films were carried out and the nanocrystalline gallium selenide films were found to be photoactive in aqueous sodium thiosulphate solution.

2008-12-30

163

Quantum Heat Engines; Multiple-State 1D Box System  

Directory of Open Access Journals (Sweden)

Full Text Available We evaluate quantum Otto, Diesel and Brayton cycles employing multiple-state 1D box system instead of ideal gas filled cylinder. The work and heat are extracted using the change in the expectation of Hamiltonian of the system which leads to the first law of thermodynamics to quantum system. The first law makes available to redefine the force which is in fact not well defined in a quantum mechanical system and then it is applied to define the quantum version of thermodynamic processes, i.e. isobaric, isovolume and adiabatic. As the results, the efficiency of quantum Otto engine depends only on the compression ratio and will be higher than the efficiency of quantum Diesel which can decrease by the widening of expansion under isobaric process. The efficiency of quantum Brayton engine may reach maximum on certain combination between the wide of box under isobaric expansion and compression, under certain conditions. The amount of levels participated in the quantum heat engine system will potentially reduce the performance of the quantum heat cycles consisting isobaric process, but it can be resisted using isobaric process controller.

Eny Latifah; Agus Purwanto

2013-01-01

164

XBWR, 1-D Xe Transients for BWR in Axial Geometry  

International Nuclear Information System (INIS)

1 - Nature of the physical problem solved: 1-D xenon transients for BWRs in axial geometry. 2 - Method of solution: XBWR couples a two group neutron diffusion calculation in plane geometry with a two phase flow cooling channel calculation and the heat conduction in the typical fuel rod. The program allows following any given power time schedule, such as shut-down and restart, day-night power variation etc., while the reactor is being kept critical by control rod movement, variable poisoning of the core, or coolant flow recirculation rate. The xenon and iodine concentrations variation is evaluated pointwise (up to 100 points) by analytical solution for successive fixed time steps. At the end of each time step a new distribution of fluxes, power, voids and temperatures is obtained, which is consistent with the reactor critical condition as it is got by variation of the control parameter taking into account the feedbacks. The new flux distribution is used as input for xenon and iodine concentrations evolution in the next time step.

1980-01-01

165

Flooding flows in city crossroads: experiments and 1-D modelling.  

UK PubMed Central (United Kingdom)

This study focuses on the discharge distribution in an intersection of four channels, similar to a city crossroad. The channels and the intersection are all horizontal. Flow enters through two of the channels, and leaves through the other two. The flow is subcritical everywhere, and flow depths are controlled by vertical weirs at the exits of the outlet channels. The main variables that are measured are the flow rates in the four channels. When the weir heights in the outlet channels are the same, the ratio of flow rates in the outlet channels depends only on the ratio of flow rates in the inlet channels; if the outlet conditions are different, other parameters, such as the total flow rate also become important. The flow has also been simulated numerically using a solution of the 1-D Saint Venant equations, with a simple model to predict flow distribution in the intersection. A comparison with the experimental data shows that this model works well for the limited range of experimental conditions studied here. However, further work is needed on a wider range of conditions, closer to real conditions, before the model can be considered valid for practical applications.

Rivière N; Perkins RJ; Chocat B; Lecus A

2006-01-01

166

1D Simulations of Series Resonant Discharges with Asymmetric Electrodes  

Science.gov (United States)

The series resonance frequency is a natural resonance, on the order of but less than the plasma frequency, which occurs in bounded plasmas. When the discharge is driven at the series resonance frequency the plasma impedance approaches a purely resistive state, allowing the discharge to be sustained at voltages of only a few times the electron temperature. This work uses 1D Particle-in-cell simulations with concentric cylindrical and spherical electrodes to study series resonant discharges in asymmetric systems. We determine scaling laws for the resonant frequency as a function of electron temperature, density and electrode radii, and compare the simulation results with theoretical calculations. Differences between cylindrical, spherical and planar systems are discussed. Choosing an appropriate driving frequency, voltage and initial plasma density, we show how the discharge ``locks on" to the resonant mode to produce a self-sustained discharge which is very different from a traditional rf-driven system. The transition is marked by a change from an almost purely capacitive discharge impedance, to an impedance with a substantial resistive component.

Smith, H. B.; Birdsall, C. K.

1999-10-01

167

Sulfur chemistry: 1D modeling in massive dense cores  

CERN Multimedia

The main sulfur-bearing molecules OCS, H2S, SO, SO2, and CS have been observed in four high mass dense cores (W43-MM1, IRAS 18264, IRAS 05358, and IRAS 18162). Our goal is to put some constraints on the relative evolutionary stage of these sources by comparing these observations with time-dependent chemical modeling. We used the chemical model Nahoon, which computes the gas-phase chemistry and gas-grain interactions of depletion and evaporation. Mixing of the different chemical compositions shells in a 1D structure through protostellar envelope has been included since observed lines suggest nonthermal supersonic broadening. Observed radial profiles of the temperature and density are used to compute the chemistry as a function of time. With our model, we underproduce CS by several orders of magnitude compared to the other S-bearing molecules, which seems to contradict observations, although some uncertainties in the CS abundance observed at high temperature remain. The OCS/SO2, SO/SO2, and H2S/SO2 abundance ra...

Wakelam, V; Herpin, F

2011-01-01

168

Second-order parametric interactions in 1-D photonic-crystal microcavity structures.  

Science.gov (United States)

We develop a generalized model for studying second-order parametric interactions in 1-D multilayered photonic structures, accounting for collinear oblique waves and partial pump depletion. This model is used to assess the performance of parametric devices in photonic-crystal microcavity (PCM) structures. Our model shows dramatic enhancement of nonlinear interactions at frequencies for which the waves are localized. Also, we demonstrate the exponential dependence of the conversion efficiency of second harmonic generation (SHG) on the number of layers as was recently pointed out. In addition, in optical parametric amplification (OPA), we find that the gain has a resonance-like dependence on the pump intensity, turning large peak gain into strong attenuation at greater intensities, which suggests that the device can operate as an optical switch. PMID:18542628

Saleh, Mohammed F; Dal Negro, Luca; Saleh, Bahaa E

2008-04-14

169

System for Digital 1D-Image Processing with 1024 Pixel CCD Sensor  

Directory of Open Access Journals (Sweden)

Full Text Available The conception of system for digital 1D-images processing with digital CCD camera is presented. The system is created from these three basic parts: the digital CCD camera with linear image sensor CCD L133C, 8-bit interface and a personal computer. The scanning digital CCD camera generated a video signals, which are processed in the analog signal processor. The output signal is continually converted to 8-bit data words in A/D converter. This data words maybe transfer over a bus driver to the operation memory of personal computer, by setting one of the three work regimes of digital CCD camera. Some application possibilities and basic technical parameters of this system are given.

P. Kulla; P. Sevcik; M. Chrenek; J. Misun

1993-01-01

170

Expression and localization of myosin-1d in the developing nervous system.  

UK PubMed Central (United Kingdom)

Myosin-1d is a monomeric actin-based motor found in a wide range of tissues, but highly expressed in the nervous system. Previous microarray studies suggest that myosin-1d is found in oligodendrocytes where transcripts are upregulated during the maturation of these cells. Myosin-1d was also identified as a component of myelin-containing subcellular fractions in proteomic studies and mutations in MYO1D have been linked to autism. Despite the potential implications of these previous studies, there is little information on the expression and localization of myosin-1d in the developing nervous system. Therefore, we analyzed myosin-1d expression patterns in the peripheral and central nervous systems during postnatal development. In mouse sciatic nerve, myosin-1d is expressed along the axon and in the ensheathing myelin compartment. Analysis of mouse cerebellum prior to myelination at day 3 reveals that myosin-1d is present in the Purkinje cell layer, granule cell layer, and region of the cerebellar nuclei. Upon the onset of myelination, myosin-1d enrichment expands along axonal tracts, while still present in the Purkinje and granule cell layers. However, myosin-1d was undetectable in oligodendrocyte progenitor cells at early and late time points. We also show that myosin-1d interacts and is co-expressed with aspartoacylase, an enzyme that plays a key role in fatty acid synthesis throughout the nervous system. Together, these studies provide a foundation for understanding the role of myosin-1d in neurodevelopment and neurological disorders.

Benesh AE; Fleming JT; Chiang C; Carter BD; Tyska MJ

2012-02-01

171

PSS-3D1D: an improved 3D1D profile method of protein fold recognition for the annotation of twilight zone sequences.  

UK PubMed Central (United Kingdom)

Annotation of any newly determined protein sequence depends on the pairwise sequence identity with known sequences. However, for the twilight zone sequences which have only 15-25% identity, the pair-wise comparison methods are inadequate and the annotation becomes a challenging task. Such sequences can be annotated by using methods that recognize their fold. Bowie et al. described a 3D1D profile method in which the amino acid sequences that fold into a known 3D structure are identified by their compatibility to that known 3D structure. We have improved the above method by using the predicted secondary structure information and employ it for fold recognition from the twilight zone sequences. In our Protein Secondary Structure 3D1D (PSS-3D1D) method, a score (w) for the predicted secondary structure of the query sequence is included in finding the compatibility of the query sequence to the known fold 3D structures. In the benchmarks, the PSS-3D1D method shows a maximum of 21% improvement in predicting correctly the ? + ? class of folds from the sequences with twilight zone level of identity, when compared with the 3D1D profile method. Hence, the PSS-3D1D method could offer more clues than the 3D1D method for the annotation of twilight zone sequences. The web based PSS-3D1D method is freely available in the PredictFold server at http://bioinfo.bdu.ac.in/servers/ .

Ganesan K; Parthasarathy S

2011-12-01

172

75 FR 11072 - Airworthiness Directives; Turbomeca Arriel 1B, 1D, 1D1, and 1S1 Turboshaft Engines  

Science.gov (United States)

...cases of gas generator 2nd stage turbine blade release have occurred, at lower...2009, to optimize the 2nd stage turbine blade life limit and the replacement...Position Check Intervals of 2nd Stage Turbine...

2010-03-10

173

CD1d expression as a prognostic marker for chronic lymphocytic leukemia.  

UK PubMed Central (United Kingdom)

ABSTRACT We analyzed the expression of CD1d, an antigen-presenting molecule, on peripheral blood leukemic cells of CLL cases by flow cytometry. We demonstrated variable expression of CD1d on leukemic lymphocytes and an association between high expression of CD1d with shorter time to treatment and overall survival of patients. CD1d was positively associated with CD38 expression, but not with unmutated VH mutational status or adverse cytogenetics of leukemic lymphocytes. Our findings support that CD1d expression is a prognostic marker for CLL.

Anastasiadis A; Kotsianidis I; Papadopoulos V; Spanoudakis E; Margaritis D; Christoforidou A; Gouliamtzi S; Tsatalas C

2013-05-01

174

Genetic variation in aldo-keto reductase 1D1 (AKR1D1) affects the expression and activity of multiple cytochrome P450s.  

Science.gov (United States)

Human liver gene regulatory (Bayesian) network analysis was previously used to identify a cytochrome P450 (P450) gene subnetwork with Aldo-keto reductase 1D1 (AKR1D1) as a key regulatory driver of this subnetwork. This study assessed the biologic importance of AKR1D1 [a key enzyme in the synthesis of bile acids, ligand activators of farnesoid X receptor (FXR), pregnane X receptor (PXR), and constitutive androstane receptor (CAR), known transcriptional regulators of P450s] to hepatic P450 expression. Overexpression of AKR1D1 in primary human hepatocytes led to increased expression of CYP3A4, CYP2C8, CYP2C9, CYP2C19, and CYP2B6. Conversely, AKR1D1 knockdown decreased expression of these P450s. We resequenced AKR1D1 from 98 donor livers and identified a 3'-untranslated region (UTR) (rs1872930) single nucleotide polymorphism (SNP) significantly associated with higher AKR1D1 mRNA expression. AKR1D1 3'-UTR-luciferase reporter studies showed that the variant allele resulted in higher luciferase activity, suggesting that the SNP increases AKR1D1 mRNA stability and/or translation efficiency. Consistent with AKR1D1's putative role as a driver of the P450 subnetwork, the AKR1D1 3'-UTR SNP was significantly associated with increased hepatic mRNA expression of multiple P450s (CYP3A4, CYP2C8, CYP2C9, CYP2C19, and CYP2B6) and CYP3A4, CYP2C8, CYP2C19, and CYP2B6 activities. After adjusting for multiple testing, the association remained significant for AKR1D1, CYP2C9, and CYP2C8 mRNA expression and CYP2C8 activity. These results provide new insights into the variation in expression and activity of P450s that can account for interindividual differences in drug metabolism/efficacy and adverse drug events. In conclusion, we provide the first experimental evidence supporting a role for AKR1D1 as a key genetic regulator of the P450 network. PMID:23704699

Chaudhry, Amarjit S; Thirumaran, Ranjit K; Yasuda, Kazuto; Yang, Xia; Fan, Yiping; Strom, Stephen C; Schuetz, Erin G

2013-05-23

175

Genetic variation in aldo-keto reductase 1D1 (AKR1D1) affects the expression and activity of multiple cytochrome P450s.  

UK PubMed Central (United Kingdom)

Human liver gene regulatory (Bayesian) network analysis was previously used to identify a cytochrome P450 (P450) gene subnetwork with Aldo-keto reductase 1D1 (AKR1D1) as a key regulatory driver of this subnetwork. This study assessed the biologic importance of AKR1D1 [a key enzyme in the synthesis of bile acids, ligand activators of farnesoid X receptor (FXR), pregnane X receptor (PXR), and constitutive androstane receptor (CAR), known transcriptional regulators of P450s] to hepatic P450 expression. Overexpression of AKR1D1 in primary human hepatocytes led to increased expression of CYP3A4, CYP2C8, CYP2C9, CYP2C19, and CYP2B6. Conversely, AKR1D1 knockdown decreased expression of these P450s. We resequenced AKR1D1 from 98 donor livers and identified a 3'-untranslated region (UTR) (rs1872930) single nucleotide polymorphism (SNP) significantly associated with higher AKR1D1 mRNA expression. AKR1D1 3'-UTR-luciferase reporter studies showed that the variant allele resulted in higher luciferase activity, suggesting that the SNP increases AKR1D1 mRNA stability and/or translation efficiency. Consistent with AKR1D1's putative role as a driver of the P450 subnetwork, the AKR1D1 3'-UTR SNP was significantly associated with increased hepatic mRNA expression of multiple P450s (CYP3A4, CYP2C8, CYP2C9, CYP2C19, and CYP2B6) and CYP3A4, CYP2C8, CYP2C19, and CYP2B6 activities. After adjusting for multiple testing, the association remained significant for AKR1D1, CYP2C9, and CYP2C8 mRNA expression and CYP2C8 activity. These results provide new insights into the variation in expression and activity of P450s that can account for interindividual differences in drug metabolism/efficacy and adverse drug events. In conclusion, we provide the first experimental evidence supporting a role for AKR1D1 as a key genetic regulator of the P450 network.

Chaudhry AS; Thirumaran RK; Yasuda K; Yang X; Fan Y; Strom SC; Schuetz EG

2013-08-01

176

A small molecule inhibitor of p53-inducible protein phosphatase PPM1D.  

UK PubMed Central (United Kingdom)

PPM1D is a p53-inducible Ser/Thr protein phosphatase. PPM1D gene amplification and overexpression have been reported in a variety of human tumors, including breast cancer and neuroblastoma. Because the phosphatase activity of PPM1D is essential for its oncogenic role, PPM1D inhibitors should be viable anti-cancer agents. In our current study, we showed that SPI-001 was a potent and specific PPM1D inhibitor. SPI-001 inhibited PPM1D phosphatase activity in PPM1D-overexpressing human breast cancer cells and increased phosphorylation of p53. Furthermore, SPI-001 suppressed cell proliferation by inducing apoptosis. Our present study suggested that SPI-001 was a potential lead compound in developing anti-cancer drugs.

Yagi H; Chuman Y; Kozakai Y; Imagawa T; Takahashi Y; Yoshimura F; Tanino K; Sakaguchi K

2012-01-01

177

A Thr/Ser dual residue motif in the cytoplasmic tail of human CD1d is important for the down-regulation of antigen presentation following a herpes simplex virus 1 infection.  

Science.gov (United States)

CD1d-restricted T (natural killer T; NKT) cells are important for controlling herpesvirus infections. Interestingly, herpes simplex virus (HSV) can down-regulate CD1d-mediated activation of NKT cells. We have previously shown that the Thr322 residue in the cytoplasmic tail of human CD1d is important for its intracellular trafficking and functional expression. We proposed that the phosphorylation of T322 is a signal for CD1d lysosomal targeting and subsequent degradation. In the current study, we generated dual mutants by substituting the T322 and S323 residues of wild-type (WT) CD1d with Ala (non-phosphorylatable) or Asp (mimicking phosphorylation) and ectopically expressed them in human embryonic kidney 293 cells. We found that the surface expression levels of the CD1d mutants was in this order: T322AS323A > WT > T322A > S323A > S323D > T322D > T322DS323D. Our results therefore suggest that mimicking the phosphorylation of both T322 and S323 has a cumulative negative effect on the functional expression of CD1d. As previously reported, we also found that upon an HSV infection, antigen presentation by WT CD1d is reduced and the CD1d molecule is degraded. Interestingly, the T322A/S323A double mutation inhibited CD1d degradation and rescued CD1d-mediated antigen presentation following an HSV-1 infection. This suggests that the T322/S323 dyad may be phosphorylated, which then targets CD1d for lysosomal degradation post-infection as a means of immune evasion, explaining (at least in part) the reduced antigen presentation observed. Hence, our findings strongly suggest that T322 and S323 form a dual residue motif that can regulate the functional expression of CD1d during a viral infection. PMID:23710894

Liu, Jianyun; Glosson, Nicole L; Du, Wenjun; Gervay-Hague, Jacquelyn; Brutkiewicz, Randy R

2013-10-01

178

A Thr/Ser dual residue motif in the cytoplasmic tail of human CD1d is important for the down-regulation of antigen presentation following a herpes simplex virus 1 infection.  

UK PubMed Central (United Kingdom)

CD1d-restricted T (natural killer T; NKT) cells are important for controlling herpesvirus infections. Interestingly, herpes simplex virus (HSV) can down-regulate CD1d-mediated activation of NKT cells. We have previously shown that the Thr322 residue in the cytoplasmic tail of human CD1d is important for its intracellular trafficking and functional expression. We proposed that the phosphorylation of T322 is a signal for CD1d lysosomal targeting and subsequent degradation. In the current study, we generated dual mutants by substituting the T322 and S323 residues of wild-type (WT) CD1d with Ala (non-phosphorylatable) or Asp (mimicking phosphorylation) and ectopically expressed them in human embryonic kidney 293 cells. We found that the surface expression levels of the CD1d mutants was in this order: T322AS323A > WT > T322A > S323A > S323D > T322D > T322DS323D. Our results therefore suggest that mimicking the phosphorylation of both T322 and S323 has a cumulative negative effect on the functional expression of CD1d. As previously reported, we also found that upon an HSV infection, antigen presentation by WT CD1d is reduced and the CD1d molecule is degraded. Interestingly, the T322A/S323A double mutation inhibited CD1d degradation and rescued CD1d-mediated antigen presentation following an HSV-1 infection. This suggests that the T322/S323 dyad may be phosphorylated, which then targets CD1d for lysosomal degradation post-infection as a means of immune evasion, explaining (at least in part) the reduced antigen presentation observed. Hence, our findings strongly suggest that T322 and S323 form a dual residue motif that can regulate the functional expression of CD1d during a viral infection.

Liu J; Glosson NL; Du W; Gervay-Hague J; Brutkiewicz RR

2013-10-01

179

DNA damage signaling induced by the G-quadruplex ligand 12459 is modulated by PPM1D/WIP1 phosphatase.  

UK PubMed Central (United Kingdom)

The triazine derivative 12459 is a potent G-quadruplex ligand that triggers apoptosis or delayed growth arrest, telomere shortening and G-overhang degradation, as a function of its concentration and time exposure to the cells. We have investigated here the DNA damage response induced by 12459 in A549 cells. Submicromolar concentrations of 12459 triggers a delayed Chk1-ATR-mediated DNA damage response associated with a telomeric dysfunction and a G2/M arrest. Surprisingly, increasing concentrations of 12459 leading to cell apoptosis induced a mechanism that bypasses the DNA damage signaling and leads to the dephosphorylation of Chk1 and ?-H2AX. We identified the phosphatase Protein Phosphatase Magnesium dependent 1D/Wild-type P53-Induced Phosphatase (PPM1D/WIP1) as a factor responsible for this dephosphorylation. SiRNA-mediated depletion of PPM1D/WIP1 reactivates the DNA damage signaling by 12459. In addition, PPM1D/WIP1 is activated by reactive oxygen species (ROS) induced by 12459. ROS generated by 12459 are sufficient to trigger an early DNA damage in A549 cells when PPM1D/WIP1 is depleted. However, ROS inactivation by N-acetyl cysteine (NAC) treatment does not change the apoptotic response induced by 12459. Because PPM1D expression was recently reported to modulate the recruitment of DNA repair molecules, our data would suggest a cycle of futile protection against 12459, thus leading to a delayed mechanism of cell death.

Douarre C; Mergui X; Sidibe A; Gomez D; Alberti P; Mailliet P; Trentesaux C; Riou JF

2013-04-01

180

Calibração binocular com gabaritos 1D sem restrição demovimentos/ Binocular calibration with 1D parttern without movements restriction  

Scientific Electronic Library Online (English)

Full Text Available Abstract in portuguese Na visão computacional, a calibração de câmeras é um processo necessário quando deseja-se recuperar informações como, por exemplo, ângulos e distâncias. O presente trabalho trata do problema de calibração de câmeras com gabaritos de uma única dimensão. Atualmente, tal problema só tem solução se forem impostas restrições ao movimento do gabarito ou se alguns parâmetros das câmeras já sejam previamente conhecidos. Contudo, demonstra-se que uma abordag (more) em diferente pode ser aplicada se, ao invés de uma única câmera, um conjunto binocular for considerado. Nesse caso, a calibração é possível com um gabarito 1D que realiza um deslocamento desconhecido e sem restrições, mesmo sem nenhuma informação prévia a respeito das câmeras. Tal método baseia-se na estimação de uma transformação que, após a estimação da matriz fundamental do sistema, permite atualizar uma calibração projetiva para uma calibração euclidiana. Experimentos em imagens reais e sintéticas validam o novo método e mostram que a sua exatidão é comparável a de outros métodos clássicos de calibração, já bem conhecidos na literatura. Abstract in english In computer vision, the camera calibration is a process needed when the recovery of some information, such as angles and distances, is desired. The present work deals with the problem of camera calibration using one-dimensional patterns. Nowadays, this problem only has a solution if some restrictions to the pattern's movement are imposed or if some angles of the cameras are known in advance. However, a different approach can be applied if, instead of only one camera, a st (more) ereo system is considered. In that case, the calibration is possible with a one-dimensional pattern that executes an unknown and unrestricted movement, even without any previous information concerning the cameras. Such method is based on the estimation of a transform which, after the estimation of the system's fundamental matrix, allows updating a projective calibration into a Euclidean calibration. Experiments using both real and synthetic images validate the new method and demonstrate that its accuracy is comparable to other well known calibration methods in the literature.

França, José Alexandre de; França, Maria Bernadete de M.; Stemmer, Marcelo Ricardo; Palácios, Rodrigo Henrique C.

2011-06-01

 
 
 
 
181

Multiplet structure of the defect modes in 1D helical photonic crystals with twist defects  

International Nuclear Information System (INIS)

We theoretically analyse the defect modes generated by equispaced twist defects in 1D helical (cholesteric-like) structures within their frequency gap which is such that only the first two of the four eigenwaves 1±, 2± are exponentially attenuated. n0 identical defects generate n0 different defect modes, each one represented by a linear combination of the four eigenwaves. The components 1+ and 1- are by far the dominant ones and they are localized near the defect planes. We give exact analytic expressions for the elements of the transfer and scattering matrices of the defect planes, for the functions defining the defect mode when n0 = 1, and for the defect frequencies when n0 = 1, 2, 3. In the particular case n0 = 2 and twist angle ? = ?/2, the difference between the two defect wavelengths ?d2, ?d1 depends exponentially on the distance z1 between the defect planes, going to zero for z1 ? ? and becoming as large as the entire frequency gap for z1 ? 0.

2005-10-14

182

Multiplet structure of the defect modes in 1D helical photonic crystals with twist defects  

Energy Technology Data Exchange (ETDEWEB)

We theoretically analyse the defect modes generated by equispaced twist defects in 1D helical (cholesteric-like) structures within their frequency gap which is such that only the first two of the four eigenwaves 1{sup {+-}}, 2{sup {+-}} are exponentially attenuated. n{sub 0} identical defects generate n{sub 0} different defect modes, each one represented by a linear combination of the four eigenwaves. The components 1{sup +} and 1{sup -} are by far the dominant ones and they are localized near the defect planes. We give exact analytic expressions for the elements of the transfer and scattering matrices of the defect planes, for the functions defining the defect mode when n{sub 0} = 1, and for the defect frequencies when n{sub 0} = 1, 2, 3. In the particular case n{sub 0} = 2 and twist angle {theta} = {pi}/2, the difference between the two defect wavelengths {lambda}{sub d2}, {lambda}{sub d1} depends exponentially on the distance z{sub 1} between the defect planes, going to zero for z{sub 1} {yields} {infinity} and becoming as large as the entire frequency gap for z{sub 1} {yields} 0.

Avendano, C G [Instituto de Fisica, Universidad Nacional Autonoma de Mexico, Apdo. P 20-364 01000, Mexico DF (Mexico); Ponti, S [Dipartimento di Fisica Politecnico di Torino and INFM, Corso Duca degli Abruzzi 24, 10129 Torino (Italy); Reyes, J A [Instituto de Fisica, Universidad Nacional Autonoma de Mexico, Apdo. P 20-364 01000, Mexico DF (Mexico); Oldano, C [Dipartimento di Fisica Politecnico di Torino and INFM, Corso Duca degli Abruzzi 24, 10129 Torino (Italy)

2005-10-14

183

A 1d Traffic Model with Threshold Parameters  

CERN Multimedia

The basic properties of traffic flow are analyzed using a simple deterministic one dimensional "car following model" with continuous variables based on a model introduced by Nagel and Herrmann [Physica A 199 254--269 (1993)] including a few modifications. As a first case we investigate the creation and propagation of jams in a platoon generated by a slow leading vehicle. In a second case we look at a system with the size L, periodic boundary conditions and identical vehicles. A strong dependence on the initial configuration of the fundamental diagram's shape can be found.

Sauermann, G

1997-01-01

184

Progress of 1D protein structure prediction at last.  

UK PubMed Central (United Kingdom)

Accuracy of predicting protein secondary structure and solvent accessibility from sequence information has been improved significantly by using information contained in multiple sequence alignments as input to a neural network system. For the Asilomar meeting, predictions for 13 proteins were generated automatically using the publicly available prediction method PHD. The results confirm the estimate of 72% three-state prediction accuracy. The fairly accurate predictions of secondary structure segments made the tool useful as a starting point for modeling of higher dimensional aspects of protein structure.

Rost B; Sander C

1995-11-01

185

PSS-3D1D: an improved 3D1D profile method of protein fold recognition for the annotation of twilight zone sequences.  

Science.gov (United States)

Annotation of any newly determined protein sequence depends on the pairwise sequence identity with known sequences. However, for the twilight zone sequences which have only 15-25% identity, the pair-wise comparison methods are inadequate and the annotation becomes a challenging task. Such sequences can be annotated by using methods that recognize their fold. Bowie et al. described a 3D1D profile method in which the amino acid sequences that fold into a known 3D structure are identified by their compatibility to that known 3D structure. We have improved the above method by using the predicted secondary structure information and employ it for fold recognition from the twilight zone sequences. In our Protein Secondary Structure 3D1D (PSS-3D1D) method, a score (w) for the predicted secondary structure of the query sequence is included in finding the compatibility of the query sequence to the known fold 3D structures. In the benchmarks, the PSS-3D1D method shows a maximum of 21% improvement in predicting correctly the ? + ? class of folds from the sequences with twilight zone level of identity, when compared with the 3D1D profile method. Hence, the PSS-3D1D method could offer more clues than the 3D1D method for the annotation of twilight zone sequences. The web based PSS-3D1D method is freely available in the PredictFold server at http://bioinfo.bdu.ac.in/servers/ . PMID:22160493

Ganesan, K; Parthasarathy, S

2011-12-03

186

Maxwell-Dirac chiral equations in (3+1)D exactly integrable; Equacoes de Maxwell-Dirac quirais em (3+1)D exatamente integraveis  

Energy Technology Data Exchange (ETDEWEB)

We study the integrability of the (3+1)-dimension chiral Maxwell-Dirac (Weyl) equations, in a formalism with local causality preservation. One characteristic of these formalisms is that even in (3+1)D we have a (3+1+D dynamic because there is no participation of the spatial coordinates orthogonal to the direction of the interaction(quantum exchange). The dynamic is conformal invariant and the equations became exactly integrable

Souza, Manoelito Martins de [Espirito Santo Univ., Vitoria, ES (Brazil). Dept. de Fisica

1994-12-31

187

Tandem repeats modify the structure of the canine CD1D gene.  

UK PubMed Central (United Kingdom)

Among the CD1 proteins that present lipid antigens to T cells, CD1d is the only one that stimulates a population of T cells with an invariant T-cell receptor known as NKT cells. Sequencing of a 722 nucleotide gap in the dog (Canis lupus familiaris) genome revealed that the canine CD1D gene lacks a sequence homologous to exon 2 of human CD1D, coding for the start codon and signal peptide. Also, the canine CD1D gene contains three different short tandem repeats that disrupt the expected gene structure. Because canine CD1D cDNA lacks sequences homologous to human exon 2 and 3, the functionality of canine CD1d protein may be affected, and this could have consequences for the development and activation of canine NKT cells.

Looringh van Beeck FA; Leegwater PA; Herrmann T; Broere F; Rutten VP; Willemse T; Van Rhijn I

2013-06-01

188

A water sound generator for pressure pulses of high energy  

Science.gov (United States)

The watershock, a water sound generator for high energy pressure pulses, is presented. The design consists of a mechanical drive with an energy accumulator, a converter from mechanical to acoustic energy, and an acoustic coupler. The dimensions of these three parts enable one to adapt the pulse width, the main frequency, and the bandwidth of the power spectrum to different requirements. The peak-shaped pressure signal of the watershock results from the sound generation by inverse water hammer and from the sound damping by acoustic cavitation. The signal is almost unrestrained from distributing forward or back-runners, and thus the analysis of the seismograms is simplified because these noise arrivals may be disregarded. In comparison to conventional sound generation, the method of sound generation by inverse water hammer shows high efficiency and large bandwidth of its power spectrum. The watershock may also be employed in investigations of frequency dependent attenuation.

Laake, Andreas; Mueller, E.-A.

189

Examination of 1D Solar Cell Model Limitations Using 3D SPICE Modeling: Preprint  

Energy Technology Data Exchange (ETDEWEB)

To examine the limitations of one-dimensional (1D) solar cell modeling, 3D SPICE-based modeling is used to examine in detail the validity of the 1D assumptions as a function of sheet resistance for a model cell. The internal voltages and current densities produced by this modeling give additional insight into the differences between the 1D and 3D models.

McMahon, W. E.; Olson, J. M.; Geisz, J. F.; Friedman, D. J.

2012-06-01

190

Expression and localization of myosin-1d in the developing nervous system.  

Science.gov (United States)

Myosin-1d is a monomeric actin-based motor found in a wide range of tissues, but highly expressed in the nervous system. Previous microarray studies suggest that myosin-1d is found in oligodendrocytes where transcripts are upregulated during the maturation of these cells. Myosin-1d was also identified as a component of myelin-containing subcellular fractions in proteomic studies and mutations in MYO1D have been linked to autism. Despite the potential implications of these previous studies, there is little information on the expression and localization of myosin-1d in the developing nervous system. Therefore, we analyzed myosin-1d expression patterns in the peripheral and central nervous systems during postnatal development. In mouse sciatic nerve, myosin-1d is expressed along the axon and in the ensheathing myelin compartment. Analysis of mouse cerebellum prior to myelination at day 3 reveals that myosin-1d is present in the Purkinje cell layer, granule cell layer, and region of the cerebellar nuclei. Upon the onset of myelination, myosin-1d enrichment expands along axonal tracts, while still present in the Purkinje and granule cell layers. However, myosin-1d was undetectable in oligodendrocyte progenitor cells at early and late time points. We also show that myosin-1d interacts and is co-expressed with aspartoacylase, an enzyme that plays a key role in fatty acid synthesis throughout the nervous system. Together, these studies provide a foundation for understanding the role of myosin-1d in neurodevelopment and neurological disorders. PMID:22284616

Benesh, Andrew E; Fleming, Jonathan T; Chiang, Chin; Carter, Bruce D; Tyska, Matthew J

2012-01-08

191

Identification of T1D susceptibility genes within the MHC region by combining protein interaction networks and SNP genotyping data  

DEFF Research Database (Denmark)

To develop novel methods for identifying new genes that contribute to the risk of developing type 1 diabetes within the Major Histocompatibility Complex (MHC) region on chromosome 6, independently of the known linkage disequilibrium (LD) between human leucocyte antigen (HLA)-DRB1, -DQA1, -DQB1 genes. We have developed a novel method that combines single nucleotide polymorphism (SNP) genotyping data with protein-protein interaction (ppi) networks to identify disease-associated network modules enriched for proteins encoded from the MHC region. Approximately 2500 SNPs located in the 4 Mb MHC region were analysed in 1000 affected offspring trios generated by the Type 1 Diabetes Genetics Consortium (T1DGC). The most associated SNP in each gene was chosen and genes were mapped to ppi networks for identification of interaction partners. The association testing and resulting interacting protein modules were statistically evaluated using permutation. A total of 151 genes could be mapped to nodes within the protein interaction network and their interaction partners were identified. Five protein interaction modules reached statistical significance using this approach. The identified proteins are well known in the pathogenesis of T1D, but the modules also contain additional candidates that have been implicated in beta-cell development and diabetic complications. The extensive LD within the MHC region makes it important to develop new methods for analysing genotyping data for identification of additional risk genes for T1D. Combining genetic data with knowledge about functional pathways provides new insight into mechanisms underlying T1D.

Brorsson, C.; Hansen, Niclas Tue

2009-01-01

192

Germline deletion of ?2 microglobulin or CD1d reduces anti-phospholipid antibody, but increases autoantibodies against non-phospholipid antigens in the NZB/W F1 model of lupus.  

Science.gov (United States)

INTRODUCTION: ?2-microglobulin (?2m) is required for the surface expression of MHC class I and class I-like proteins such as CD1d, Qa1 and neonatal Fc receptor (FcRn), all of which may impact the development of autoimmunity. Since CD1d is known to bind and present phospholipid antigens to T cells, we asked if the deficiency of ?2m or CD1d will impact the development of anti-phospholipid antibodies as compared to other aspects of lupus autoimmunity. METHODS: We introgressed the ?2m-null genotype onto the NZB and NZW backgrounds for 12 to 14 generations to generate genetically lupus-susceptible (NZB/NZW)F1 (BWF1) mice that are ?2m-deficient (?2m°). Circulating immunoglobulins (Ig), rheumatoid factor (RF), anti-DNA and anti-cardiolipin (anti-CL) antibodies, and renal disease were analyzed in these and CD1d-deficient (CD1d°) BWF1 mice that we had previously generated. RESULTS: Whereas ?2m° BWF1 mice had reduced serum IgG, they had increased mortality, nephritis, serum IgG anti-DNA antibody and RF as compared to heterozygous and wild-type littermates. These effects were recapitulated in CD1d° BWF1 mice, except that they also had increased serum IgG as compared to control littermates. Intriguingly, both ?2m° and CD1d° mice had lower serum anti-CL antibody levels than in control littermates. Such CD1d dependence of anti-CL antibody production is not mediated by CD1d/glycolipid-reactive iNKT cells, as these cells reduced the production of RF and anti-DNA antibodies but had no effect on anti-CL antibodies. CONCLUSIONS: We report a novel dichotomous role of ?2m and CD1d, whereby these molecules differently regulate autoimmunity against phospholipid versus non-phospholipid autoantigens. PMID:23531237

Singh, Ram Raj; Yang, Jun-Qi; Kim, Peter J; Halder, Ramesh C

2013-03-27

193

DOE2.1D. Building Energy Consumption Analysis  

Energy Technology Data Exchange (ETDEWEB)

DOE2 is a set of programs for the analysis of energy consumption in buildings. Programs are included to calculate the heating and cooling loads for each space (zone) in the building for each hour of a year (LOADS), to simulate the operation and response of the equipment and systems that control temperature and humidity and distribute heating and cooling to the space (SYSTEMS), to model primary energy conversion equipment that uses fuel (e.g. oil, gas, or sun) to provide the required heating, cooling, and electricity (PLANT), and to compute the life-cycle cost for building operation based on economic parameters (ECONOMICS). A user-oriented building description language (BDL) facilitates the description of the building geometry, central plant equipment, HVAC systems, occupancy, equipment, and lighting schedules, and the selection of other problem parameters. In addition to the LSPE programs (LOADS, SYSTEMS, PLANT, and ECONOMICS), the system includes the BDL processor, two report generators, a weather data processor, and UPDATE, a code maintenance program. Standard output reports are produced by the RPTGEN program. Only the weather data for Chicago, which are required for execution of the sample problems, are included.

Buhl, W.F. [Lawrence Berkeley National Lab., CA (United States)

1981-05-01

194

Mapping of the serotonin 5-HT{sub 1D{alpha}} autoreceptor gene (HTR1D) on chromosome 1 using a silent polymorphism in the coding region  

Energy Technology Data Exchange (ETDEWEB)

Serotonin (5-HT){sub ID} receptors are 5-HT release-regulating autoreceptors in the human brain. Abnormalities in brain 5-HT function have been hypothesized in the pathophysiology of various psychiatric disorders, including obsessive-compulsive disorder, autism, mood disorders, eating disorders, impulsive violent behavior, and alcoholism. Thus, mutations occurring in 5-HT autoreceptors may cause or increase the vulnerability to any of these conditions. 5-HT{sub 1D{alpha}} and 5-HT{sub 1D{Beta}} subtypes have been previously localized to chromosomes 1p36.3-p34.3 and 6q13, respectively, using rodent-human hybrids and in situ localization. In this communication, we report the detection of a 5-HT{sub 1D{alpha}} receptor gene polymorphism by single strand conformation polymorphism (SSCP) analysis of the coding sequence. The polymorphism was used for fine scale linkage mapping of 5-HT{sub 1D{alpha}} on chromosome 1. This polymorphism should also be useful for linkage studies in populations and in families. Our analysis also demonstrates that functionally significant coding sequence variants of the 5-HT{sub 1D{alpha}} are probably not abundant either among alcoholics or in the general population. 14 refs., 1 fig., 1 tab.

Ozaki, N.; Lappalainen, J.; Linnoila, M. [National Institute on Alcohol Abuse and Alcoholism, Rockville, MD (United States)] [and others

1995-04-24

195

Does one-dimensional (1D) adatom and cluster diffusion of Pt on the Pt(110)-(1 x 2) surface lead to 1D ripening?  

International Nuclear Information System (INIS)

[en] The technique of scanning tunnelling microscopy (STM) uniquely allows dynamic processes on surfaces to be followed directly in real space and at atomic resolution. Results for the 551225 surface diffusion of Pt adatoms and clusters on the anisotropic, missing row reconstructed Pt(110)-(1 x 2) surface are briefly reviewed. Mass transport in this system is entirely one-dimensional (1D) since, at low adatom coverage, atoms and clusters are confined to the missing row troughs. In this paper, we therefore address the question if Pt/Pt(110)-(1 x 2) is a 1D model system to study late stage growth phenomena such as island ripening? From STM measurements, we quantify the morphology changes resulting from annealing a surface configuration with small 1D Pt islands in the missing row troughs to temperatures in the interval 369-395 K. Interestingly, the resulting increase in island sizes (ripening) cannot be accounted for by the known island and adatom mobilities within a 1D model. An explanation is provided from dynamic, time-resolved 'STM-movies' that directly reveal two novel island-mediated mechanisms for inter-trough mass transport which cause the Pt/Pt(110)-(1 x 2) system not to be purely 1D at the higher surface coverage used in the annealing experiments

2005-01-01

196

Development of a 3D consistent 1D neutronics model for reactor core simulation  

International Nuclear Information System (INIS)

[en] In this report a 3D consistent 1D model based on nonlinear analytic nodal method is developed to reproduce the 3D results. During the derivation, the current conservation factor (CCF) is introduced which guarantees the same axial neutron currents obtained from the 1D equation as the 3D reference values. Furthermore in order to properly use 1D group constants, a new 1D group constants representation scheme employing tables for the fuel temperature, moderator density and boron concentration is developed and functionalized for the control rod tip position. To test the 1D kinetics model with CCF, several steady state and transient calculations were performed and compared with 3D reference values. The errors of K-eff values were reduced about one tenth when using CCF without significant computational overhead. And the errors of power distribution were decreased to the range of one fifth or tenth at steady state calculation. The 1D kinetics model with CCF and the 1D group constant functionalization employing tables as a function of control rod tip position can provide preciser results at the steady state and transient calculation. Thus it is expected that the 1D kinetics model derived in this report can be used in the safety analysis, reactor real time simulation coupled with system analysis code, operator support system etc.

2001-01-01

197

Influence of lipid rafts on CD1d presentation by dendritic cells  

DEFF Research Database (Denmark)

Our main objective was to analyze the role of lipid rafts in the activation of Valpha-14(-) and Valpha-14(+) T hybridomas by dendritic cells. We showed that activation of Valpha-14(+) hybridomas by dendritic cells or other CD1d-expressing cells was altered by disruption of lipid rafts with the cholesterol chelator MbetaCD. However, CD1d presentation to autoreactive Valpha-14(-) anti-CD1d hybridomas which do not require the endocytic pathway was not altered. Using partitioning of membrane fractions with Brij98 at 37 degrees C, we confirmed that CD1d was enriched in subcellular fractions corresponding to lipid rafts and we describe that alpha-GalCer enhanced CD1d amount in the low density detergent insoluble fraction. We conclude that the membrane environment of CD1d can influence antigen presentation mainly when the endocytic pathway is required. Flow cytometry analysis can provide additional information on lipid rafts in plasma membranes and allows a dynamics follow-up of lipid rafts partitioning. Using this method, we showed that CD1d plasma membrane expression was sensitive to low concentrations of detergent. This may suggest either that CD1d is associated with lipid rafts mainly in intracellular membranes or that its association with the lipid rafts in the plasma membrane is weak.

Peng, Wei; Martaresche, Cecile

2011-01-01

198

Development of a 3D consistent 1D neutronics model for reactor core simulation  

Energy Technology Data Exchange (ETDEWEB)

In this report a 3D consistent 1D model based on nonlinear analytic nodal method is developed to reproduce the 3D results. During the derivation, the current conservation factor (CCF) is introduced which guarantees the same axial neutron currents obtained from the 1D equation as the 3D reference values. Furthermore in order to properly use 1D group constants, a new 1D group constants representation scheme employing tables for the fuel temperature, moderator density and boron concentration is developed and functionalized for the control rod tip position. To test the 1D kinetics model with CCF, several steady state and transient calculations were performed and compared with 3D reference values. The errors of K-eff values were reduced about one tenth when using CCF without significant computational overhead. And the errors of power distribution were decreased to the range of one fifth or tenth at steady state calculation. The 1D kinetics model with CCF and the 1D group constant functionalization employing tables as a function of control rod tip position can provide preciser results at the steady state and transient calculation. Thus it is expected that the 1D kinetics model derived in this report can be used in the safety analysis, reactor real time simulation coupled with system analysis code, operator support system etc.

Lee, Ki Bog; Joo, Han Gyu; Cho, Byung Oh; Zee, Sung Quun

2001-02-01

199

Chiral-Odd Structure Function $h_1^D(x)$ and Tensor Charge of the Deuteron  

CERN Multimedia

The chiral-odd structure function h_{1}^D(x) and the tensor charge of the deuteron are studied within the Bethe-Salpeter formalism for the deuteron amplitude. Utilizing a simple model for the nucleon structure function, h_1^N, h_1^D(x) is calculated and the nuclear effects are analyzed.

Umnikov, A Yu; Khanna, F C; He, Han-xin

1996-01-01

200

The structure of 1D CuI crystals inside SWNTs.  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Nanocomposites consisting of one-dimensional CuI crystals inside single-walled carbon nanotubes were obtained using the capillary technique. high-resolution transmission electron microscopy investigations of the atomic structure of the encapsulated 1D CuI crystals revealed two types of 1D CuI crysta...

Kiselev, NA; Zakalyukin, RM; Zhigalina, OM; Grobert, N; Kumskov, AS

 
 
 
 
201

Construction and Analysis of Lattice Boltzmann Methods Applied to a 1D Convection-Diffusion Equation  

Digital Repository Infrastructure Vision for European Research (DRIVER)

We construct and we analyze two LBM schemes applied to a 1D convection-diffusion equation. We obtain these LBM schemes by showing that the 1D convection-diffusion equation is the fluid limit of a discrete velocity kinetic system. Then, we show that these LBM schemes are equivalent to a finite differ...

Dellacherie, Stéphane

202

Identification of RAPD Marker for Chromosome 1D of Common Wheat  

Directory of Open Access Journals (Sweden)

Full Text Available Development of genetically compensating nullisomic-tetrasomic and ditelosomic lines of commonwheat (Triticum aestivum L.) have been widely used to construct high density genetic maps of homoeologouswheat chromosomes. During present research, easier, cheaper and quicker procedure of Polymerase ChainReaction (PCR) was used to map Randomly Amplified Polymorphic DNA primers on chromosome 1D ofcommon wheat. Genomic DNA was isolated from two genetic stocks of wheat cultivar Chinese Spring viz;NT-1D1B and NT-2A2B. PCR were conducted using RAPD primers GLC-07 and GLC-11. RAPD primerGLC-11 amplified a polymorphic allele of approximately 500 bp, which was present in NT-2A2B (used aspositive control) but was absent in NT-1D1B indicating that the locus is present on chromosome 1D of commonwheat. Hence this marker (GLC-11) can reliably be used to keep track of chromosome 1D of hexaploid wheat.

Imtiaz Ahmad Khan

2010-01-01

203

A new time domain random walk method for solute transport in 1-D heterogeneous media  

Energy Technology Data Exchange (ETDEWEB)

A new method to simulate solute transport in 1-D heterogeneous media is presented. This time domain random walk method (TDRW), similar in concept to the classical random walk method, calculates the arrival time of a particle cloud at a given location (directly providing the solute breakthrough curve). The main advantage of the method is that the restrictions on the space increments and the time steps which exist with the finite differences and random walk methods are avoided. In a homogeneous zone, the breakthrough curve (BTC) can be calculated directly at a given distance using a few hundred particles or directly at the boundary of the zone. Comparisons with analytical solutions and with the classical random walk method show the reliability of this method. The velocity and dispersivity calculated from the simulated results agree within two percent with the values used as input in the model. For contrasted heterogeneous media, the random walk can generate high numerical dispersion, while the time domain approach does not.

Banton, O. [Univ. du Quebec, Ste-Foy, Quebec (Canada). Inst. National de la Recherche Scientifique; Delay, F. [Univ. P and M Curie, Paris (France). Lab. de Geologie Appliquee; Porel, G. [Univ. de Poitiers (France). Lab. d`Hydrogeologie

1997-11-01

204

Technical Note: Sensitivity of 1-D smoke plume rise models to the inclusion of environmental wind drag  

Directory of Open Access Journals (Sweden)

Full Text Available Vegetation fires emit hot gases and particles which are rapidly transported upward by the positive buoyancy generated by the combustion process. In general, the final vertical height that the smoke plumes reach is controlled by the thermodynamic stability of the atmospheric environment and the surface heat flux released by the fire. However, the presence of a strong horizontal wind can enhance the lateral entrainment and induce additional drag, particularly for small fires, impacting the smoke injection height. In this paper, we revisit the parameterization of the vertical transport of hot gases and particles emitted from vegetation fires, described in Freitas et al. (2007), to include the effects of environmental wind on transport and dilution of the smoke plume at its scale. This process is quantitatively represented by introducing an additional entrainment term to account for organized inflow of a mass of cooler and drier ambient air into the plume and its drag by momentum transfer. An extended set of equations including the horizontal motion of the plume and the additional increase of the plume radius is solved to simulate the time evolution of the plume rise and the smoke injection height. One-dimensional (1-D) model results are presented for two deforestation fires in the Amazon basin with sizes of 10 and 50 ha under calm and windy atmospheric environments. The results are compared to corresponding simulations generated by the complex non-hydrostatic three-dimensional (3-D) Active Tracer High resolution Atmospheric Model (ATHAM). We show that the 1-D model results compare well with the full 3-D simulations. The 1-D model may thus be used in field situations where extensive computing facilities are not available, especially under conditions for which several optional cases must be studied.

S. R. Freitas; K. M. Longo; J. Trentmann; D. Latham

2010-01-01

205

The organic anion transport polypeptide 1d1 (Oatp1d1) mediates hepatocellular uptake of phalloidin and microcystin into skate liver  

International Nuclear Information System (INIS)

Organic anion transporting polypeptides (rodent Oatp; human OATP) mediate cellular uptake of numerous organic compounds including xenobiotic toxins into mammalian hepatocytes. In the little skate Leucoraja erinacea a liver-specific Oatp (Oatp1d1, also called sOatp) has been identified and suggested to represent an evolutionarily ancient precursor of the mammalian liver OATP1B1 (human), Oatp1b2 (rat), and OATP1B3 (human). The present study tested whether Oatp1d1 shares functional transport activity of the xenobiotic oligopeptide toxins phalloidin and microcystin with the mammalian liver Oatps/OATPs. The phalloidin analogue [3H]-demethylphalloin was taken up into skate hepatocytes with high affinity (Km ? 0.4 ?M), and uptake could be inhibited by phalloidin and a variety of typical Oatp/OATP substrates such as bromosulfophthalein, bile salts, estrone-3-sulfate, cyclosporine A and high concentrations of microcystin-LR (Ki ? 150 ?M). When expressed in Xenopus laevis oocytes Oatp1d1 increased uptake of demethylphalloin (Km ? 2.2 ?M) and microcystin-LR (Km ? 27 ?M) 2- to 3-fold over water-injected oocytes, whereas the alternative skate liver organic anion transporter, the dimeric Ost?/?, exhibited no phalloidin and only minor microcystin-LR transport. Also, the closest mammalian Oatp1d1 orthologue, the human brain and testis OATP1C1, did not show any phalloidin transport activity. These results demonstrate that the evolutionarily ancient Oatp1d1 is able to mediate uptake of cyclic oligopeptide toxins into skate liver. The findings support the notion that Oatp1d1 is a precursor of the liver-specific mammalian Oatps/OATPs and that its transport properties are closely associated with certain forms of toxic liver injury such as for example protein phosphatase inhibition by the water-borne toxin microcystin

2007-02-01

206

Phosphine-Free Synthesis from 1D Pb(OH)Cl Nanowires to 0D and 1D PbSe Nanocrystals.  

UK PubMed Central (United Kingdom)

In this paper, we report a new phosphine-free, low-cost, low-temperature colloidal method of controlled synthesis of PbSe nanocrystals in both zero-dimension (0D) and one-dimension (1D). Different from the widely used "hot injection" method and "nonprecursor injection" method, the novelty of this new method is that it does not require a nucleation process. Instead, high-quality presynthesized 1D Pb(OH)Cl nanowires (?80 to ?160 nm in diameter) can be directly used as a Pb precursor and reacted with a Se precursor to form monodisperse dot-shaped 0D cubic PbSe and 1D orthorhombic PbSe nanowires. 0D cubic PbSe nanocrystals begin to form at elevated temperatures after the Se precursor is added to react with Pb(OH)Cl nanowires. By prolonging the reaction time for 3 h, good self-assembled 0D cubic PbSe nanocrystals can be synthesized with an average diameter of about 15 nm. Furthermore, such method has been demonstrated to synthsize high-quality 1D PbSe nanowires successfully with temperature as low as 110 °C. 1D PbSe nanowires possess a mean diameter of 15-24 nm with the shortest and longest length from 600 nm to 5 ?m. The only sharp and strong peak, which is consistent with characteristic peaks of orthorhombic PbSe, indicates that the nanowires' elongation axis is in the [111] direction, and 0D cubic PbSe nanocrystals change to 1D orthorhombic PbSe nanowires completely.

Shen H; Li J; Shang H; Niu J; Xu W; Wang H; Guo F; Li LS

2013-10-01

207

Structure and Catalytic Mechanism of Human Steroid 5-Reductase (AKR1D1)  

Energy Technology Data Exchange (ETDEWEB)

Human steroid 5{beta}-reductase (aldo-keto reductase (AKR) 1D1) catalyzes reduction of {Delta}{sup 4}-ene double bonds in steroid hormones and bile acid precursors. We have reported the structures of an AKR1D1-NADP{sup +} binary complex, and AKR1D1-NADP{sup +}-cortisone, AKR1D1-NADP{sup +}-progesterone and AKR1D1-NADP{sup +}-testosterone ternary complexes at high resolutions. Recently, structures of AKR1D1-NADP{sup +}-5{beta}-dihydroprogesterone complexes showed that the product is bound unproductively. Two quite different mechanisms of steroid double bond reduction have since been proposed. However, site-directed mutagenesis supports only one mechanism. In this mechanism, the 4-pro-R hydride is transferred from the re-face of the nicotinamide ring to C5 of the steroid substrate. E120, a unique substitution in the AKR catalytic tetrad, permits a deeper penetration of the steroid substrate into the active site to promote optimal reactant positioning. It participates with Y58 to create a 'superacidic' oxyanion hole for polarization of the C3 ketone. A role for K87 in the proton relay proposed using the AKR1D1-NADP{sup +}-5{beta}-dihydroprogesterone structure is not supported.

Costanzo, L.; Drury, J; Christianson, D; Penning, T

2009-01-01

208

Structure and catalytic mechanism of human steroid 5?-reductase (AKR1D1)  

Science.gov (United States)

Human steroid 5?-reductase (aldo-keto reductase (AKR) 1D1) catalyzes reduction of ?4-ene double bonds in steroid hormones and bile acid precursors. We have reported the structures of an AKR1D1-NADP+ binary complex, and AKR1D1-NADP+-cortisone, AKR1D1-NADP+-progesterone and AKR1D1-NADP+-testosterone ternary complexes at high resolutions. Recently, structures of AKR1D1-NADP+-5?-dihydroprogesterone complexes showed that the product is bound unproductively. Two quite different mechanisms of steroid double bond reduction have since been proposed. However, site-directed mutagenesis supports only one mechanism. In this mechanism, the 4-pro-R hydride is transferred from the re-face of the nicotinamide ring to C5 of the steroid substrate. E120, a unique substitution in the AKR catalytic tetrad, permits a deeper penetration of the steroid substrate into the active site to promote optimal reactant positioning. It participates with Y58 to create a “superacidic” oxyanion hole for polarization of the C3 ketone. A role for K87 in the proton relay proposed using the AKR1D1-NADP+-5?-dihydroprogesterone structure is not supported.

Di Costanzo, Luigi; Drury, Jason E.; Christianson, David W.; Penning, Trevor M.

2009-01-01

209

A comparison of 1-D and 2-D algorithms for radar target classification  

Science.gov (United States)

The use of high-resolution radar measurement data from four ground vehicles (bulldozer, Dodge Power Wagon, Dodge Van, and Camaro) to evaluate the performance of several 1D and 2D classifiers is discussed. The 1D classifiers use high-resolution range profiles to classify targets; the 2D classifier uses high-resolution inverse synthetic aperture radar (ISAR) images to classify targets. Classification performance results using the 1D and 2D algorithms are presented, and it is shown that the 2D algorithm performed best.

Novak, Leslie M.

210

LXF1D/LXF2D. 1 and 2-Dimensional Line Transfer Package  

Energy Technology Data Exchange (ETDEWEB)

LXF1D is a one dimensional steady-state line transfer package designed to handle: overlapping and or interacting lines, planar, cylindrical, spherical (and special) geometries, doppler shifts, complete redistribution (CRD), partial redistribution (PRD). PRD requires the use of REDIST or some other package to produce emission profiles. LXF2D is a two dimensional version of LXF1D for xy and rz geometries. Both LXF1D and LXF2D are designed to be added to existing non-local thermodynamic equilibrium (NLTE) codes with a minimum of effort.

Scott, H. [Lawrence Livermore National Lab., CA (United States)

1990-07-01

211

Modulation bandwidth of planar waveguide laser with 1D photonic crystal mirrors  

Science.gov (United States)

An analysis of the 3-dB modulation bandwidth in planar waveguide laser based on 1D photonic crystal structures is presented. The theoretical model takes into account the gain saturation effect, transverse and longitudinal field distribution. A small-signal perturbation solution of the coupled laser rate equation is used to obtain relations describing the dynamic operation. In paper, the distributed Bragg resonator DBR created as 1D photonic crystal is considered. The active waveguide is surrounded by 1D photonic crystal mirrors consisting of alternately placed stripes with different refractive indices. In particular, the influence of the photonic crystal parameters on the 3-dB modulation bandwidth is investigated.

Mossakowska-Wyszy?ska, A.

2012-12-01

212

A 1-D coordination polymer based on a Mn40 octagonal super-structure.  

UK PubMed Central (United Kingdom)

A 1-D coordination polymer, constructed using a combination of diols and phenolic oximes, contains a novel [Mn(9)] sub-unit, a nanosized [Mn(40)] octagonal super-structure and a [Mn(21)] repeating unit.

Manoli M; Inglis R; Manos MJ; Papaefstathiou GS; Brechin EK; Tasiopoulos AJ

2013-02-01

213

Modeling blood flow circulation in intracranial arterial networks: a comparative 3D/1D simulation study.  

Science.gov (United States)

We compare results from numerical simulations of pulsatile blood flow in two patient-specific intracranial arterial networks using one-dimensional (1D) and three-dimensional (3D) models. Specifically, we focus on the pressure and flowrate distribution at different segments of the network computed by the two models. Results obtained with 1D and 3D models with rigid walls show good agreement in massflow distribution at tens of arterial junctions and also in pressure drop along the arteries. The 3D simulations with the rigid walls predict higher amplitude of the flowrate and pressure temporal oscillations than the 1D simulations with compliant walls at various segments even for small time-variations in the arterial cross-sectional areas. Sensitivity of the flow and pressure with respect to variation in the elasticity parameters is investigated with the 1D model. PMID:20661645

Grinberg, L; Cheever, E; Anor, T; Madsen, J R; Karniadakis, G E

2010-07-27

214

Modeling blood flow circulation in intracranial arterial networks: a comparative 3D/1D simulation study.  

UK PubMed Central (United Kingdom)

We compare results from numerical simulations of pulsatile blood flow in two patient-specific intracranial arterial networks using one-dimensional (1D) and three-dimensional (3D) models. Specifically, we focus on the pressure and flowrate distribution at different segments of the network computed by the two models. Results obtained with 1D and 3D models with rigid walls show good agreement in massflow distribution at tens of arterial junctions and also in pressure drop along the arteries. The 3D simulations with the rigid walls predict higher amplitude of the flowrate and pressure temporal oscillations than the 1D simulations with compliant walls at various segments even for small time-variations in the arterial cross-sectional areas. Sensitivity of the flow and pressure with respect to variation in the elasticity parameters is investigated with the 1D model.

Grinberg L; Cheever E; Anor T; Madsen JR; Karniadakis GE

2011-01-01

215

User's manual of the REFLA-1D/MODE4 reflood thermo-hydrodynamic analysis code  

International Nuclear Information System (INIS)

REFLA-1D/MODE4 code has been developed by incorporating local power effect model and fuel temperature profile effect model into REFLA-1D/MODE3 code. This code can calculate the temperature transient of local rod by considering radial power profile effect in core and simulate the thermal characteristics of the nuclear fuel rod. This manual describes the outline of incorporated models, modification of the code with incorporating models and provides application information required to utilize the code. (author)

1986-01-01

216

Surface impedance model for extraordinary transmission in 1D metallic and dielectric screens.  

UK PubMed Central (United Kingdom)

Extraordinary Optical Transmission of TM waves impinging at oblique incidence on metallic or high permittivity dielectric screens with a periodic distribution of 1D slits or any other kind of 1D defects is analyzed. Generalized waveguide theory altogether with the surface impedance concept are used for modeling such phenomena. A numerical analysis based on the mode matching technique proves to be an efficient tool for the characterization of these structures for any angle of incidence and slit or defect apertures.

Delgado V; Marqués R

2011-12-01

217

Surface impedance model for extraordinary transmission in 1D metallic and dielectric screens.  

Science.gov (United States)

Extraordinary Optical Transmission of TM waves impinging at oblique incidence on metallic or high permittivity dielectric screens with a periodic distribution of 1D slits or any other kind of 1D defects is analyzed. Generalized waveguide theory altogether with the surface impedance concept are used for modeling such phenomena. A numerical analysis based on the mode matching technique proves to be an efficient tool for the characterization of these structures for any angle of incidence and slit or defect apertures. PMID:22273919

Delgado, V; Marqués, R

2011-12-01

218

Optimization of a cyclic peptide inhibitor of Ser/Thr phosphatase PPM1D (Wip1).  

Science.gov (United States)

PPM1D (PP2C? or Wip1) was identified as a wild-type p53-induced Ser/Thr phosphatase that accumulates after DNA damage and classified into the PP2C family. It dephosphorylates and inactivates several proteins critical for cellular stress responses, including p38 MAPK, p53, and ATM. Furthermore, PPM1D is amplified and/or overexpressed in a number of human cancers. Thus, inhibition of its activity could constitute an important new strategy for therapeutic intervention to halt the progression of several different cancers. Previously, we reported the development of a cyclic thioether peptide with low micromolar inhibitory activity toward PPM1D. Here, we describe important improvements in the inhibitory activity of this class of cyclic peptides and also present a binding model based upon the results. We found that specific interaction of an aromatic ring at the X1 position and negative charge at the X5 and X6 positions significantly increased the inhibitory activity of the cyclic peptide, with the optimized molecule having a K(i) of 110 nM. To the best of our knowledge, this represents the highest inhibitory activity reported for an inhibitor of PPM1D. We further developed an inhibitor selective for PPM1D over PPM1A with a K(i) of 2.9 ?M. Optimization of the cyclic peptide and mutagenesis experiments suggest that a highly basic loop unique to PPM1D is related to substrate specificity. We propose a new model for the catalytic site of PPM1D and inhibition by the cyclic peptides that will be useful both for the subsequent design of PPM1D inhibitors and for identification of new substrates. PMID:21528848

Hayashi, Ryo; Tanoue, Kan; Durell, Stewart R; Chatterjee, Deb K; Jenkins, Lisa M Miller; Appella, Daniel H; Appella, Ettore

2011-05-09

219

Optimization of a cyclic peptide inhibitor of Ser/Thr phosphatase PPM1D (Wip1).  

UK PubMed Central (United Kingdom)

PPM1D (PP2C? or Wip1) was identified as a wild-type p53-induced Ser/Thr phosphatase that accumulates after DNA damage and classified into the PP2C family. It dephosphorylates and inactivates several proteins critical for cellular stress responses, including p38 MAPK, p53, and ATM. Furthermore, PPM1D is amplified and/or overexpressed in a number of human cancers. Thus, inhibition of its activity could constitute an important new strategy for therapeutic intervention to halt the progression of several different cancers. Previously, we reported the development of a cyclic thioether peptide with low micromolar inhibitory activity toward PPM1D. Here, we describe important improvements in the inhibitory activity of this class of cyclic peptides and also present a binding model based upon the results. We found that specific interaction of an aromatic ring at the X1 position and negative charge at the X5 and X6 positions significantly increased the inhibitory activity of the cyclic peptide, with the optimized molecule having a K(i) of 110 nM. To the best of our knowledge, this represents the highest inhibitory activity reported for an inhibitor of PPM1D. We further developed an inhibitor selective for PPM1D over PPM1A with a K(i) of 2.9 ?M. Optimization of the cyclic peptide and mutagenesis experiments suggest that a highly basic loop unique to PPM1D is related to substrate specificity. We propose a new model for the catalytic site of PPM1D and inhibition by the cyclic peptides that will be useful both for the subsequent design of PPM1D inhibitors and for identification of new substrates.

Hayashi R; Tanoue K; Durell SR; Chatterjee DK; Jenkins LM; Appella DH; Appella E

2011-05-01

220

Fluorine substitution enhanced photovoltaic performance of a D-A1-D-A2 copolymer.  

UK PubMed Central (United Kingdom)

A new alternating donor-acceptor (D-A1-D-A2) copolymer containing two electron-deficient moieties, isoindigo and quinoxaline, was synthesized. The photovoltaic performance of this polymer could be improved by incorporating fluorine atoms into the quinoxaline units, resulting in an efficiency of 6.32%. This result highlights the attractive promise of D-A1-D-A2 copolymers for high-performance bulk heterojunction solar cells.

Dang D; Chen W; Yang R; Zhu W; Mammo W; Wang E

2013-09-01

 
 
 
 
221

Fluorine substitution enhanced photovoltaic performance of a D-A1-D-A2 copolymer.  

Science.gov (United States)

A new alternating donor-acceptor (D-A1-D-A2) copolymer containing two electron-deficient moieties, isoindigo and quinoxaline, was synthesized. The photovoltaic performance of this polymer could be improved by incorporating fluorine atoms into the quinoxaline units, resulting in an efficiency of 6.32%. This result highlights the attractive promise of D-A1-D-A2 copolymers for high-performance bulk heterojunction solar cells. PMID:24000353

Dang, Dongfeng; Chen, Weichao; Yang, Renqiang; Zhu, Weiguo; Mammo, Wendimagegn; Wang, Ergang

2013-09-17

222

O(1D) Production Following Electron Impact on Oxygen-Containing Molecules  

International Nuclear Information System (INIS)

[en] A solid Ne matrix detector is used to study electron-impact dissociation pathways in CO2 and N2O. This matrix is selectively sensitive to the metastable oxygen species, O(1D). O(1D) is an important constituent in the atmospheres of Earth and other extra-terrestrial objects. Kinetic energy and excitation function data for production of this species will be presented.

2012-11-05

223

DNA damage signaling induced by the G-quadruplex ligand 12459 is modulated by PPM1D/WIP1 phosphatase.  

Science.gov (United States)

The triazine derivative 12459 is a potent G-quadruplex ligand that triggers apoptosis or delayed growth arrest, telomere shortening and G-overhang degradation, as a function of its concentration and time exposure to the cells. We have investigated here the DNA damage response induced by 12459 in A549 cells. Submicromolar concentrations of 12459 triggers a delayed Chk1-ATR-mediated DNA damage response associated with a telomeric dysfunction and a G2/M arrest. Surprisingly, increasing concentrations of 12459 leading to cell apoptosis induced a mechanism that bypasses the DNA damage signaling and leads to the dephosphorylation of Chk1 and ?-H2AX. We identified the phosphatase Protein Phosphatase Magnesium dependent 1D/Wild-type P53-Induced Phosphatase (PPM1D/WIP1) as a factor responsible for this dephosphorylation. SiRNA-mediated depletion of PPM1D/WIP1 reactivates the DNA damage signaling by 12459. In addition, PPM1D/WIP1 is activated by reactive oxygen species (ROS) induced by 12459. ROS generated by 12459 are sufficient to trigger an early DNA damage in A549 cells when PPM1D/WIP1 is depleted. However, ROS inactivation by N-acetyl cysteine (NAC) treatment does not change the apoptotic response induced by 12459. Because PPM1D expression was recently reported to modulate the recruitment of DNA repair molecules, our data would suggest a cycle of futile protection against 12459, thus leading to a delayed mechanism of cell death. PMID:23396447

Douarre, Céline; Mergui, Xénia; Sidibe, Assitan; Gomez, Dennis; Alberti, Patrizia; Mailliet, Patrick; Trentesaux, Chantal; Riou, Jean-François

2013-02-08

224

Technical Note: Sensitivity of 1-D smoke plume rise models to the inclusion of environmental wind drag  

Directory of Open Access Journals (Sweden)

Full Text Available We revisit the parameterization of the vertical transport of hot gases and particles emitted from biomass burning, described in Freitas et al. (2007), to include the effects of environmental wind on transport and dilution of the smoke plume at the cloud scale. Typically, the final vertical height that the smoke plumes reach is controlled by the thermodynamic stability of the atmospheric environment and the surface heat flux released by the fire. However, the presence of a strong horizontal wind can enhance the lateral entrainment and induce additional drag, particularly for small fires, impacting the smoke injection height. This process is quantitatively represented by introducing an additional entrainment term to account for organized inflow of a mass of cooler and drier ambient air into the plume and its drag by momentum transfer. An extended set of equations including the horizontal motion of the plume and the additional increase of the plume radius is solved to explicitly simulate the time evolution of the plume rise with the additional mass and momentum. One-dimensional (1-D) model results are presented for two deforestation fires in the Amazon basin with sizes of 10 and 50 ha under calm and windy atmospheric environments. The results are compared to corresponding simulations generated by the complex non-hydrostatic three dimensional (3-D) Active Tracer High resolution Atmospheric Model (ATHAM). We show that the 1-D model results compare well with the full 3-D simulations. The 1-D model may thus be used in field situations where extensive computing facilities are not available, especially under conditions for which several optional cases must be studied.

S. R. Freitas; K. M. Longo; J. Trentmann; D. Latham

2009-01-01

225

Theoretical modeling for quantum liquids from 1d to 2d dimensional crossover using quantum groups  

CERN Document Server

Recent experimental and theoretical work in strongly correlated electron system necessitates a formulation to deal with 1d to 2d dimensional crossover and raises several interesting questions. A particularly interesting question is what happens to the 1d Luttinger liquid, as we go from 1d to 2d? The main point of emphasis of the present note is that the transition from 1d to 2d has an underlying quantum group symmetry. This relationhip of 1d to 2d transition with quantum group symmetry ties in nicely with our previous proposal to model superconductivity, antiferromagnetism and related phases arising from strongly correlated electron states with quantum groups. A simple model based on two interacting chains with nearest neighbor and next to nearest neighbor interactions is suggested. It appears reasonable to assume that it is the interaction between the 1d Luttinger liquids which leads to the quantum group symmetry and the transition to 2d quantum liquid. The conditions under which this 2d quantum liquid devia...

Alam, S; Alam, Sher

1999-01-01

226

The relation of scan range and reflection shape in single-crystal 1D profile measurement  

International Nuclear Information System (INIS)

Changes in shape of 1D profiles of small-single-crystal Bragg reflections have been examined in terms of the shapes of the components which, convoluted together, generate the profile. In most practical cases, operational features require truncation of the angular scan range of measurement and the conventional linear formula for scan range, ?=a+bxtan ?, is then not strictly valid. A more appropriate relationship involves a combination of root mean square (RMS) and linear (LIN) forms, ?=[(p')2+(q'xtan ?2]1/2 + (p''+q''xtan ?) where p' is associated with the leading and trailing edges of the distribution of the combined ?-invariant components and p'' with its plateau width while q' is associated with the leading and trailing edges of the distribution of the wavelength component and q'' with the separation of its outer peaks if there are more than one. For operational purposes, this relationship can be substituted with adequate precision by ?=[c2+(dxtan ?)2]1/2, but the parameters c and d do not then have a simple relationship to the ?-invariant and ?-variant components. Use of a conventional linear formula when a RMS one is the relevant one can mean that, in the lower ? range, the estimate of integrated intensity will be too high and, in the higher ? range, it will be too low, so that, with increasing ?, a positive then a negative systematic error is introduced and not merely a negative error as the conventional interpretation of truncation holds. The conclusions of the present analysis are tested against experimental data where the conventional treatment for truncation failed. For the estimation of integrated intensity, and hence of structure factors, which are consistent over the operational range of ?, a RMS formula for the scan range is advisable. (orig.).

1989-01-01

227

1-D/3-D geologic model of the Western Canada Sedimentary Basin  

Science.gov (United States)

The 3-D geologic model of the Western Canada Sedimentary Basin comprises 18 stacked intervals from the base of the Devonian Woodbend Group and age equivalent formations to ground surface; it includes an estimated thickness of eroded sediments based on 1-D burial history reconstructions for 33 wells across the study area. Each interval for the construction of the 3-D model was chosen on the basis of whether it is primarily composed of petroleum system elements of reservoir, hydrocarbon source, seal, overburden, or underburden strata, as well as the quality and areal distribution of well and other data. Preliminary results of the modeling support the following interpretations. Long-distance migration of hydrocarbons east of the Rocky Mountains is indicated by oil and gas accumulations in areas within which source rocks are thermally immature for oil and (or) gas. Petroleum systems in the basin are segmented by the northeast-trending Sweetgrass Arch; hydrocarbons west of the arch were from source rocks lying near or beneath the Rocky Mountains, whereas oil and gas east of the arch were sourced from the Williston Basin. Hydrocarbon generation and migration are primarily due to increased burial associated with the Laramide Orogeny. Hydrocarbon sources and migration were also influenced by the Lower Cretaceous sub-Mannville unconformity. In the Peace River Arch area of northern Alberta, Jurassic and older formations exhibit high-angle truncations against the unconformity. Potential Paleozoic though Mesozoic hydrocarbon source rocks are in contact with overlying Mannville Group reservoir facies. In contrast, in Saskatchewan and southern Alberta the contacts are parallel to sub-parallel, with the result that hydrocarbon source rocks are separated from the Mannville Group by seal-forming strata within the Jurassic. Vertical and lateral movement of hydrocarbons along the faults in the Rocky Mountains deformed belt probably also resulted in mixing of oil and gas from numerous source rocks in Alberta.

Higley, D. K.; Henry, M.; Roberts, L. N. R.; Steinshouer, D. W.

2005-01-01

228

Regulation of exosome secretion by Rab35 and its GTPase-activating proteins TBC1D10A-C.  

Science.gov (United States)

Oligodendrocytes secrete vesicles into the extracellular space, where they might play a role in neuron-glia communication. These exosomes are small vesicles with a diameter of 50-100 nm that are formed within multivesicular bodies and are released after fusion with the plasma membrane. The intracellular pathways that generate exosomes are poorly defined. Because Rab family guanosine triphosphatases (GTPases) together with their regulators are important membrane trafficking organizers, we investigated which Rab GTPase-activating proteins interfere with exosome release. We find that TBC1D10A-C regulate exosome secretion in a catalytic activity-dependent manner. We show that Rab35 is the target of TBC1D10A-C and that the inhibition of Rab35 function leads to intracellular accumulation of endosomal vesicles and impairs exosome secretion. Rab35 localizes to the surface of oligodendroglia in a GTP-dependent manner, where it increases the density of vesicles, suggesting a function in docking or tethering. These findings provide a basis for understanding the biogenesis and function of exosomes in the central nervous system. PMID:20404108

Hsu, Chieh; Morohashi, Yuichi; Yoshimura, Shin-Ichiro; Manrique-Hoyos, Natalia; Jung, Sangyong; Lauterbach, Marcel A; Bakhti, Mostafa; Grønborg, Mads; Möbius, Wiebke; Rhee, Jeongseop; Barr, Francis A; Simons, Mikael

2010-04-19

229

Regulation of exosome secretion by Rab35 and its GTPase-activating proteins TBC1D10A-C.  

UK PubMed Central (United Kingdom)

Oligodendrocytes secrete vesicles into the extracellular space, where they might play a role in neuron-glia communication. These exosomes are small vesicles with a diameter of 50-100 nm that are formed within multivesicular bodies and are released after fusion with the plasma membrane. The intracellular pathways that generate exosomes are poorly defined. Because Rab family guanosine triphosphatases (GTPases) together with their regulators are important membrane trafficking organizers, we investigated which Rab GTPase-activating proteins interfere with exosome release. We find that TBC1D10A-C regulate exosome secretion in a catalytic activity-dependent manner. We show that Rab35 is the target of TBC1D10A-C and that the inhibition of Rab35 function leads to intracellular accumulation of endosomal vesicles and impairs exosome secretion. Rab35 localizes to the surface of oligodendroglia in a GTP-dependent manner, where it increases the density of vesicles, suggesting a function in docking or tethering. These findings provide a basis for understanding the biogenesis and function of exosomes in the central nervous system.

Hsu C; Morohashi Y; Yoshimura S; Manrique-Hoyos N; Jung S; Lauterbach MA; Bakhti M; Grønborg M; Möbius W; Rhee J; Barr FA; Simons M

2010-04-01

230

Role of human CD4 D1D2 domain in HIV-1 infection.  

UK PubMed Central (United Kingdom)

Broadly neutralizing antibodies and appropriate immunogens are critical for preexposure prophylaxis and therapeutic HIV vaccines. In this study, we aimed to explore effective antibodies against the genetically diverse HIV-1 strains by investigating the roles of human CD4 D1D2 domain and nonvariable immugens. The human CD4 D1D2 domain and the chimeric protein of mouse D1 domain/human D2 domain were expressed in Sf9 insect cells and purified by gel-filtration chromatography. The human CD4 D1D2 domain potently inhibited the infection of 77.8% HIV-1 pseudoviruses, including the clades AE, B' and BC, with less than 20 ?g/mL of IC(50). pcDNA3.1-mhD1D2m and pcDNA3.1-mhD2m plasmids were used for the production of mouse anti-human CD4 polyclonal antibodies. The neutralizing activities of the polyclonal antibodies were determined by using pseudotyped HIV-1 viruses. The antibodies induced by plasmids containing human CD4 D1D2 domain were able to potently inhibit all pseudotyped HIV-1 strains. The antibodies from mhD1D2m-immunized mice also showed strong binding capacity to CD4 expressed on the surface of TZM-bl cells. The potent and broad inhibitory activity of antibodies against the human CD4 D1D2 domain may be used to develop effective passive immunization agent to control the spread of HIV infection.

Li L; Shi X; Lu Q; Zhang S; Wang X; Jiang X; Liu Y; Wang G; Zhu W; Lei R; Wu H

2013-01-01

231

Substrate specificity and inhibitor analyses of human steroid 5?-reductase (AKR1D1)  

Science.gov (United States)

Human steroid 5?-reductase (Aldo-keto Reductase 1D1) catalyzes the stereospecific NADPH-dependent reduction of the C4-C5 double bond of ?4-ketosteroids to yield an A/B cis-ring junction. This cis-configuration is crucial for bile acid biosynthesis and plays important roles in steroid metabolism. The biochemical properties of the enzyme have not been thoroughly studied and conflicting data have been reported, partially due to the lack of highly homogeneous protein. In the present study, we systematically determined the substrate specificity of homogeneous human recombinant AKR1D1 using C18, C19, C21, and C27 ?4-ketosteroids and assessed the pH-rate dependence of the enzyme. Our results show that AKR1D1 proficiently reduced all the steroids tested at physiological pH, indicating AKR1D1 is the only enzyme necessary for all the 5?-steroid metabolite present in humans. Substrate inhibition was observed with C18 to C21 steroids provided that the side-chain at C17 was unsubstituted. This structure activity relationship can be explained by the existence of a small alternative substrate binding pocket revealed by the AKR1D1 crystal structure. Non-steroidal anti-inflammatory drugs which are potent inhibitors of the related AKR1C enzymes do not inhibit AKR1D1 by contrast chenodeoxycholate and ursodeoxycholate were found to be potent non-competitive inhibitors suggesting that bile-acids may regulate their own synthesis at the level of AKR1D1 inhibition.

Chen, Mo; Drury, Jason E.; Penning, Trevor M.

2011-01-01

232

Role of human CD4 D1D2 domain in HIV-1 infection.  

Science.gov (United States)

Broadly neutralizing antibodies and appropriate immunogens are critical for preexposure prophylaxis and therapeutic HIV vaccines. In this study, we aimed to explore effective antibodies against the genetically diverse HIV-1 strains by investigating the roles of human CD4 D1D2 domain and nonvariable immugens. The human CD4 D1D2 domain and the chimeric protein of mouse D1 domain/human D2 domain were expressed in Sf9 insect cells and purified by gel-filtration chromatography. The human CD4 D1D2 domain potently inhibited the infection of 77.8% HIV-1 pseudoviruses, including the clades AE, B' and BC, with less than 20 ?g/mL of IC(50). pcDNA3.1-mhD1D2m and pcDNA3.1-mhD2m plasmids were used for the production of mouse anti-human CD4 polyclonal antibodies. The neutralizing activities of the polyclonal antibodies were determined by using pseudotyped HIV-1 viruses. The antibodies induced by plasmids containing human CD4 D1D2 domain were able to potently inhibit all pseudotyped HIV-1 strains. The antibodies from mhD1D2m-immunized mice also showed strong binding capacity to CD4 expressed on the surface of TZM-bl cells. The potent and broad inhibitory activity of antibodies against the human CD4 D1D2 domain may be used to develop effective passive immunization agent to control the spread of HIV infection. PMID:23252862

Li, Lan; Shi, Xuanling; Lu, Qingyu; Zhang, Senyan; Wang, Xinquan; Jiang, Xu; Liu, Yifeng; Wang, Guanshi; Zhu, Weijun; Lei, Rongyue; Wu, Hao

2012-12-19

233

PIH1D1 interacts with mTOR complex 1 and enhances ribosome RNA transcription.  

Science.gov (United States)

PIH1D1 is the defining component of the R2TP complex. Recently, R2TP has been reported to stabilize mTOR (mammalian target of rapamycin), an important regulator of cell growth and protein synthesis. Two complexes of mTOR, mTORC1 and mTORC2, have been identified. We demonstrate that immunoprecipitation (IP) of PIH1D1 results in the co-IP of Raptor (mTORC1 specific), but not Rictor (mTORC2 specific), and that knockdown of PIH1D1 decreases mTORC1 assembly, S6 kinase phosphorylation (indicator of mTORC1 activity), and rRNA transcription without affecting mTORC2 in human breast cancer MCF-7 cells. In addition, we provide evidence that PIH1D1 is overexpressed in various breast cancer cell lines. These findings collectively suggest that PIH1D1 may have an important role in mTORC1 regulation in breast cancers. PMID:24036451

Kamano, Yuya; Saeki, Makio; Egusa, Hiroshi; Kakihara, Yoshito; Houry, Walid A; Yatani, Hirofumi; Kamisaki, Yoshinori

2013-09-11

234

The TBC1D1 gene: structure, function, and association with obesity and related traits.  

UK PubMed Central (United Kingdom)

This review summarizes what is currently known on the TBC1 (tre-2/USP6, BUB2, cdc16) domain family, member 1 (TBC1D1) gene and gives an overview of its links with human obesity and related traits, taking also information from other animals. Several studies indicated that TBC1D1 contributes to the development of obesity by regulating skeletal muscle insulin sensitivity. A polymorphic site (p.R125W) in the human gene has been associated with female body mass index (BMI) in a few different cohorts. Few other polymorphisms in this gene were associated with BMI and diabetic nephropathy. Following a candidate gene approach, polymorphisms in the pig TBC1D1 gene were associated with fat deposition traits. In chicken, a few quantitative trait loci for growth and fat deposition were localized in the region containing TBC1D1. These complementary results could contribute to further understand the role of TBC1D1 in developing obesity.

Fontanesi L; Bertolini F

2013-01-01

235

Force on a slow moving impurity due to thermal and quantum fluctuations in a 1D Bose-Einstein condensate  

Energy Technology Data Exchange (ETDEWEB)

We study the drag force acting on an impurity moving through a 1D Bose-Einstein condensate in the presence of both quantum and thermal fluctuations. We are able to find exact analytical solutions of the partial differential equations to the level of the Bogoliubov approximation. At zero temperature, we find a nonzero force is exerted on the impurity at subcritical velocities, due to the scattering of quantum fluctuations. We make the following explicit assumptions: far from the impurity the system is in a quantum state given by that of a zero (or finite) temperature Bose-Einstein condensate, and the scattering process generates only causally related reflection/transmission. The results raise unanswered questions in the quantum dynamics associated with the formation of persistent currents.

Roberts, David [Los Alamos National Laboratory; Sykes, Andrew [UNIV OF QUEENSLAND

2009-01-01

236

Hidden nonlinear su(2|2) superunitary symmetry of N=2 superextended 1D Dirac delta potential problem  

International Nuclear Information System (INIS)

[en] We show that the N=2 superextended 1D quantum Dirac delta potential problem is characterized by the hidden nonlinear su(2|2) superunitary symmetry. The unexpected feature of this simple supersymmetric system is that it admits three different Z2-gradings, which produce a separation of 16 integrals of motion into three different sets of 8 bosonic and 8 fermionic operators. These three different graded sets of integrals generate two different nonlinear, deformed forms of su(2|2), in which the Hamiltonian plays a role of a multiplicative central charge. On the ground state, the nonlinear superalgebra is reduced to the two distinct 2D Euclidean analogs of a superextended Poincare algebra used earlier in the literature for investigation of spontaneous supersymmetry breaking. We indicate that the observed exotic supersymmetric structure with three different Z2-gradings can be useful for the search of hidden symmetries in some other quantum systems, in particular, related to the Lame equation

2008-01-24

237

Vertically integrated ZnO-Based 1D1R structure for resistive switching  

International Nuclear Information System (INIS)

[en] We report a ZnO-based 1D1R structure, which is formed by a vertical integration of a FeZnO/MgO switching resistor (1R) and an Ag/MgZnO Schottky diode (1D). The multifunctional ZnO and its compounds are grown through MOCVD with in situ doping. For the R element, the current ratio of the high-resistance state (HRS) over the low-resistance state (LRS) at 1 V is 2.4 × 106. The conduction mechanisms of the HRS and LRS are Poole–Frenkel emission and resistive conduction, respectively. The D element shows the forward/reverse current ratio at ±1 V to be 2.4 × 107. This 1D1R structure exhibits high RHRS/RLRS ratio, excellent rectifying characteristics and robust retention. (paper)

2013-04-10

238

Vertically integrated ZnO-Based 1D1R structure for resistive switching  

Science.gov (United States)

We report a ZnO-based 1D1R structure, which is formed by a vertical integration of a FeZnO/MgO switching resistor (1R) and an Ag/MgZnO Schottky diode (1D). The multifunctional ZnO and its compounds are grown through MOCVD with in situ doping. For the R element, the current ratio of the high-resistance state (HRS) over the low-resistance state (LRS) at 1 V is 2.4 × 106. The conduction mechanisms of the HRS and LRS are Poole-Frenkel emission and resistive conduction, respectively. The D element shows the forward/reverse current ratio at ±1 V to be 2.4 × 107. This 1D1R structure exhibits high RHRS/RLRS ratio, excellent rectifying characteristics and robust retention.

Zhang, Yang; Duan, Ziqing; Li, Rui; Ku, Chieh-Jen; Reyes, Pavel I.; Ashrafi, Almamun; Zhong, Jian; Lu, Yicheng

2013-04-01

239

The structure of 1D CuI crystals inside SWNTs.  

Science.gov (United States)

Nanocomposites consisting of one-dimensional CuI crystals inside single-walled carbon nanotubes were obtained using the capillary technique. high-resolution transmission electron microscopy investigations of the atomic structure of the encapsulated 1D CuI crystals revealed two types of 1D CuI crystals with growth direction and relative to the bulk hexagonal CuI structure. Atomic structure models were proposed based on the high-resolution transmission electron microscopy images. According to the proposed models and image simulations, the main contrast in the 1D crystal images arises from the iodine atoms whereas copper atoms, with lower atomic number giving lower contrast, are thought to be statistically distributed. PMID:19017232

Kiselev, N A; Zakalyukin, R M; Zhigalina, O M; Grobert, N; Kumskov, A S; Grigoriev, Yu V; Chernysheva, M V; Eliseev, A A; Krestinin, A V; Tretyakov, Yu D; Freitag, B; Hutchison, J L

2008-11-01

240

The structure of 1D CuI crystals inside SWNTs.  

UK PubMed Central (United Kingdom)

Nanocomposites consisting of one-dimensional CuI crystals inside single-walled carbon nanotubes were obtained using the capillary technique. high-resolution transmission electron microscopy investigations of the atomic structure of the encapsulated 1D CuI crystals revealed two types of 1D CuI crystals with growth direction <001> and <110> relative to the bulk hexagonal CuI structure. Atomic structure models were proposed based on the high-resolution transmission electron microscopy images. According to the proposed models and image simulations, the main contrast in the 1D crystal images arises from the iodine atoms whereas copper atoms, with lower atomic number giving lower contrast, are thought to be statistically distributed.

Kiselev NA; Zakalyukin RM; Zhigalina OM; Grobert N; Kumskov AS; Grigoriev YV; Chernysheva MV; Eliseev AA; Krestinin AV; Tretyakov YD; Freitag B; Hutchison JL

2008-11-01

 
 
 
 
241

DOE-2 BDL (Building Description Language) summary, Version 2. 1D  

Energy Technology Data Exchange (ETDEWEB)

This package of updates to the DOE-2 documentation brings the previously published materials (with the exception of the Users Guide) up to Version 2.1D of the DOE-2 program. The user may verify that the program being used is 2.1D by checking the first page of the output and also the upper right hand heading of any output page of the computer printout. This document contains in concise form the basic information on all commands and keywords in the DOE-2 Building Description Language (BDL) as well as a number of supplementary tables and maps.

1989-06-01

242

Step-orientation-dependent oxidation: from 1D to 2D oxides.  

Science.gov (United States)

Using scanning tunneling microscopy and density functional theory, we have studied the initial oxidation of Rh(111) surfaces with two types of straight steps, having {100} and {111} microfacets. The one-dimensional (1D) oxide initially formed at the steps acts as a barrier impeding formation of the 2D oxide on the (111) terrace behind it. We demonstrate that the details of the structure of the 1D oxide govern the rate of 2D oxidation and discuss implications for oxidation of nanoparticles. PMID:19437652

Klikovits, J; Schmid, M; Merte, L R; Varga, P; Westerström, R; Resta, A; Andersen, J N; Gustafson, J; Mikkelsen, A; Lundgren, E; Mittendorfer, F; Kresse, G

2008-12-31

243

Single File Diffusion enhancement in a fluctuating modulated 1D channel  

CERN Document Server

We show that the diffusion of a single file of particles moving in a fluctuating modulated 1D channel is enhanced with respect to the one in a bald pipe. This effect, induced by the fluctuations of the modulation, is favored by the incommensurability between the channel potential modulation and the moving file periodicity. This phenomenon could be of importance in order to optimize the critical current in superconductors, in particular in the case where mobile vortices move in 1D channels designed by adapted patterns of pinning sites.

Coupier, G; Guthmann, C; Coupier, Gwennou; Jean, Michel Saint; Guthmann, Claudine

2006-01-01

244

Fermions tunnelling from GHS and non-extremal D1-D5 black holes  

Energy Technology Data Exchange (ETDEWEB)

Recent research shows that fermions tunnelling can result in correct Hawking temperature of a black hole. In this letter, choosing a set of appropriate matrices {gamma}{sup {mu}}, we attempt to study Hawking radiation of Dirac particles across the horizons of the GHS and non-extremal five-dimensional D1-D5 black holes in string theory by using fermions tunnelling method. Finally, the expected Hawking temperatures of the GHS and non-extremal D1-D5 black holes are correctly recovered.

Jiang Qingquan [Institute of Particle Physics, Central China Normal University, Wuhan, Hubei 430079 (China)], E-mail: jiangqq@iopp.ccnu.edu.cn

2008-09-11

245

CRUNCH 1D: a computer program for seismic analysis of the HTGR core  

International Nuclear Information System (INIS)

[en] This document serves as a user's manual and theoretical manual for the CRUNCH1D computer program. CRUNCH1D is a numerical integration code designed to analyze the HTGR core for seismic excitation. The core is represented as a one-dimensional horizontal strip of blocks constrained within the PCRV. Each block of the CRUNCH model represents one or more columns of the actual core. One additional block is provided to model the core support floor. Seismic excitation is provided by defining the motion of the PCRV. CRUNCH has two types of mathematical models for collisions; the standard spring-damper model, and an impulse-momentum model

1977-01-01

246

Heat Conduction and Long-Range Spatial Correlation in 1D Models  

CERN Document Server

Heat conduction in a 1D model is studied. The model can be analytically treated, based on the mesoscopic electronic transport theory (METT). The normal heat conduction is correspondent with the incoherent transport in METT. By defining a `phase' correlation between particles at the two ends of the 1D chain, we find that the randomization of scatterers implies the absence of the correlation, which it indicates a normal thermal conductivity. For comparing, we also numerically simulate the energy transport in the model. The results are help for understanding some previous researches about the condition to get the normal heat conduction.

Zhou, X; Zhou, Xin; Iwamoto, Mitsumasa

2002-01-01

247

One-Electron Charge and Spin Singular Branch Lines of the 1D Hubbard Model  

CERN Document Server

The momentum and energy dependence of the line shape in the vicinity of the one-electron spectral-function charge and spin singular branch lines of the 1D Hubbard model is studied for all values of the electronic density and on-site repulsion U. To achieve this goal we use a method which relies on the direct evaluation of the matrix elements between the energy eigenstates. Our theoretical predictions agree quantitatively for the whole momentum and energy bandwidth with the peak dispersions observed by angle-resolved photoelectron spectroscopy in the quasi-1D organic conductor TTF-TCNQ.

Carmelo, J M P; Martelo, L M; Sacramento, P D; López dos Santos, J M B; Claessen, R; Sing, M; Schwingenschlögl, U

2003-01-01

248

One-Electron Singular Spectral Features of the 1D Hubbard Model  

CERN Document Server

The momentum and energy dependence of the weight distribution in the vicinity of the one-electron spectral-function charge and spin singular branch lines of the 1D Hubbard model is studied for all values of the electronic density and on-site repulsion $U$. To achieve this goal we use a pseudofermion dynamical theory recently introduced, which relies on the direct evaluation of the matrix elements between the energy eigenstates. Our theoretical predictions agree quantitatively for the whole momentum and energy bandwidth with the peak dispersions observed by angle-resolved photoelectron spectroscopy in the quasi-1D organic conductor TTF-TCNQ.

Carmelo, J M P; Martelo, L M; Sacramento, P D; López dos Santos, J M B; Claessen, R; Sing, M; Schwingenschlögl, U

2004-01-01

249

Effects of carbon-bound deuterium on the affinities of acetaldehyde-1-d and N-methylformamide-1-d for solvent water  

Energy Technology Data Exchange (ETDEWEB)

With deuterium present in the formyl group, the equilibrium constant for transfer of N-methylformamide from chloroform to D/sub 2/O at 25/sup 0/C was enhanced by a factor of 3.1 +- 0.15%, as estimated independently by proton magnetic resonance and by double-labeling experiments in which /sup 14/C and /sup 3/H were incorporated alternatively into the methyl group. The distribution coefficient of acetaldehyde-1-d between D/sub 2/O and the vapor phase, on the other hand, differed from that of acetaldehyde by less than 0.5%.

Wolfenden, R.; Kirkman, S.

1983-02-23

250

Molecular, Physicochemical and Rheological Characteristics of Introgressive Triticale/Triticum monococcum ssp. monococcum Lines with Wheat 1D/1A Chromosome Substitution  

Directory of Open Access Journals (Sweden)

Full Text Available Three sets of hexaploid introgressive triticale lines, with Triticum monococcum ssp. monococcum (cultivated einkorn wheat) genes and a bread wheat chromosome 1D substituted for chromosome 1A, and one set of secondary triticale lines were evaluated for grain and flour physicochemical and dough rheological characteristics in two generations (F7 and F8). Genomic in situ hybridization (GISH) and fluorescence in situ hybridization (FISH) confirmed the 1D/1A chromosome substitution. The presence or absence of einkorn high-molecular-weight (HMW) glutenin subunits and the wheat Glu-D1d locus encoding the 5 + 10 subunits was assessed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), capillary zone electrophoresis, and allele-specific molecular markers. Significant differences were found among physicochemical properties (with the exception of the Hagberg falling number) of all introgressive Triticale/T. monococcum lines and the secondary triticale lines. The wheat 1D/1A chromosome substitution also affected these properties. The results showed that in all introgressive triticale lines, the protein and gluten content, Zeleny sedimentation value, and water absorption capacity, were increased. The rheological parameters estimated using micro-farinograph, reomixer, and Kieffer dough extensibility systems also showed an appreciable increase in dough-mixing properties, maximum resistance to extension (Rmax), and dough extensibility. Introgressive Triticale/T. monococcum lines with 5 + 10 subunits have particularly favorable rheological parameters. The results obtained in this study suggest that the cultivated einkorn genome Am, in the context of hexaploid secondary triticale lines and with a wheat 1D/1A substitution, has the potential to improve gluten polymer interactions and be a valuable genetic resource for triticale quality improvement.

Boles?aw P. Salmanowicz; Monika Langner; Halina Wi?niewska; Barbara Apolinarska; Micha? Kwiatek; Lidia B?aszczyk

2013-01-01

251

Molecular, Physicochemical and Rheological Characteristics of Introgressive Triticale/Triticum monococcum ssp. monococcum Lines with Wheat 1D/1A Chromosome Substitution  

Science.gov (United States)

Three sets of hexaploid introgressive triticale lines, with Triticum monococcum ssp. monococcum (cultivated einkorn wheat) genes and a bread wheat chromosome 1D substituted for chromosome 1A, and one set of secondary triticale lines were evaluated for grain and flour physicochemical and dough rheological characteristics in two generations (F7 and F8). Genomic in situ hybridization (GISH) and fluorescence in situ hybridization (FISH) confirmed the 1D/1A chromosome substitution. The presence or absence of einkorn high-molecular-weight (HMW) glutenin subunits and the wheat Glu-D1d locus encoding the 5 + 10 subunits was assessed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), capillary zone electrophoresis, and allele-specific molecular markers. Significant differences were found among physicochemical properties (with the exception of the Hagberg falling number) of all introgressive Triticale/T. monococcum lines and the secondary triticale lines. The wheat 1D/1A chromosome substitution also affected these properties. The results showed that in all introgressive triticale lines, the protein and gluten content, Zeleny sedimentation value, and water absorption capacity, were increased. The rheological parameters estimated using micro-farinograph, reomixer, and Kieffer dough extensibility systems also showed an appreciable increase in dough-mixing properties, maximum resistance to extension (Rmax), and dough extensibility. Introgressive Triticale/T. monococcum lines with 5 + 10 subunits have particularly favorable rheological parameters. The results obtained in this study suggest that the cultivated einkorn genome Am, in the context of hexaploid secondary triticale lines and with a wheat 1D/1A substitution, has the potential to improve gluten polymer interactions and be a valuable genetic resource for triticale quality improvement.

Salmanowicz, Boleslaw P.; Langner, Monika; Wisniewska, Halina; Apolinarska, Barbara; Kwiatek, Michal; Blaszczyk, Lidia

2013-01-01

252

Molecular, physicochemical and rheological characteristics of introgressive Triticale/Triticum monococcum ssp. monococcum lines with wheat 1D/1A chromosome substitution.  

UK PubMed Central (United Kingdom)

Three sets of hexaploid introgressive triticale lines, with Triticum monococcum ssp. monococcum (cultivated einkorn wheat) genes and a bread wheat chromosome 1D substituted for chromosome 1A, and one set of secondary triticale lines were evaluated for grain and flour physicochemical and dough rheological characteristics in two generations (F7 and F8). Genomic in situ hybridization (GISH) and fluorescence in situ hybridization (FISH) confirmed the 1D/1A chromosome substitution. The presence or absence of einkorn high-molecular-weight (HMW) glutenin subunits and the wheat Glu-D1d locus encoding the 5 + 10 subunits was assessed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), capillary zone electrophoresis, and allele-specific molecular markers. Significant differences were found among physicochemical properties (with the exception of the Hagberg falling number) of all introgressive Triticale/T. monococcum lines and the secondary triticale lines. The wheat 1D/1A chromosome substitution also affected these properties. The results showed that in all introgressive triticale lines, the protein and gluten content, Zeleny sedimentation value, and water absorption capacity, were increased. The rheological parameters estimated using micro-farinograph, reomixer, and Kieffer dough extensibility systems also showed an appreciable increase in dough-mixing properties, maximum resistance to extension (Rmax), and dough extensibility. Introgressive Triticale/T. monococcum lines with 5 + 10 subunits have particularly favorable rheological parameters. The results obtained in this study suggest that the cultivated einkorn genome Am, in the context of hexaploid secondary triticale lines and with a wheat 1D/1A substitution, has the potential to improve gluten polymer interactions and be a valuable genetic resource for triticale quality improvement.

Salmanowicz BP; Langner M; Wi?niewska H; Apolinarska B; Kwiatek M; B?aszczyk L

2013-01-01

253

The relation of scan range and reflection shape in single-crystal 1D profile measurement  

Energy Technology Data Exchange (ETDEWEB)

Changes in shape of 1D profiles of small-single-crystal Bragg reflections have been examined in terms of the shapes of the components which, convoluted together, generate the profile. In most practical cases, operational features require truncation of the angular scan range of measurement and the conventional linear formula for scan range, {omega}=a+bxtan {theta}, is then not strictly valid. A more appropriate relationship involves a combination of root mean square (RMS) and linear (LIN) forms, {omega}=((p'){sup 2}+ q'xtan {theta}{sup 2}){sup 1/2} + (p''+q''xtan {theta}) where p' is associated with the leading and trailing edges of the distribution of the combined {theta}-invariant components and p'' with its plateau width while q' is associated with the leading and trailing edges of the distribution of the wavelength component and q'' with the separation of its outer peaks if there are more than one. For operational purposes, this relationship can be substituted with adequate precision by {omega}=(c{sup 2}+(dxtan {theta}){sup 2}){sup 1/2}, but the parameters c and d do not then have a simple relationship to the {theta}-invariant and {theta}-variant components. Use of a conventional linear formula when a RMS one is the relevant one can mean that, in the lower {theta} range, the estimate of integrated intensity will be too high and, in the higher {theta} range, it will be too low, so that, with increasing {theta}, a positive then a negative systematic error is introduced and not merely a negative error as the conventional interpretation of truncation holds. The conclusions of the present analysis are tested against experimental data where the conventional treatment for truncation failed. For the estimation of integrated intensity, and hence of structure factors, which are consistent over the operational range of {theta}, a RMS formula for the scan range is advisable. (orig.).

Mathieson, A.M. (La Trobe Univ., Bundoora (Australia). Dept. of Chemistry)

1989-09-01

254

1-D Two-phase Flow Investigation for External Reactor Vessel Cooling  

Energy Technology Data Exchange (ETDEWEB)

During a severe accident, when a molten corium is relocated in a reactor vessel lower head, the RCF(Reactor Cavity Flooding) system for ERVC (External Reactor Vessel Cooling) is actuated and coolants are supplied into a reactor cavity to remove a decay heat from the molten corium. This severe accident mitigation strategy for maintaining a integrity of reactor vessel was adopted in the nuclear power plants of APR1400, AP600, and AP1000. Under the ERVC condition, the upward two-phase flow is driven by the amount of the decay heat from the molten corium. To achieve the ERVC strategy, the two-phase natural circulation in the annular gap between the external reactor vessel and the insulation should be formed sufficiently by designing the coolant inlet/outlet area and gap size adequately on the insulation device. Also the natural circulation flow restriction has to be minimized. In this reason, it is needed to review the fundamental structure of insulation. In the existing power plants, the insulation design is aimed at minimizing heat losses under a normal operation. Under the ERVC condition, however, the ability to form the two-phase natural circulation is uncertain. Namely, some important factors, such as the coolant inlet/outlet areas, flow restriction, and steam vent etc. in the flow channel, should be considered for ERVC design. T-HEMES 1D study is launched to estimate the natural circulation flow under the ERVC condition of APR1400. The experimental facility is one-dimensional and scaled down as the half height and 1/238 channel area of the APR1400 reactor vessel. The air injection method was used to simulate the boiling at the external reactor vessel and generate the natural circulation two-phase flow. From the experimental results, the natural circulation flow rate highly depended on inlet/outlet areas and the circulation flow rate increased as the outlet height as well as the supplied water head increased. On the other hand, the simple analysis using the drift flux model was carried out to predict the natural circulation flow rate and estimate the pressure drop distribution from the momentum equation. The calculated circulation flow rate was similar to experimental results within about 15% error bound. Also the effect of the turbine flow meter, which was installed to measure the circulation flow rate, was found that the natural circulation flow rate decreased due to the form loss of the turbine flow meter. And the simple analysis without the pressure drop of the turbine flow meter was performed to estimate the natural circulation phenomena under the actual ERVC condition.

Kim, Jae Cheol

2007-02-15

255

Syntheses, crystal structures and luminescent properties of two new 1D d 1 coordination polymers constructed from 2,2'-bibenzimidazole and 1,4-benzenedicarboxylate  

International Nuclear Information System (INIS)

[en] Two novel interesting d 1 metal coordination polymers, [Zn(H2bibzim)(BDC)] n (1) and [Cd(H2bibzim)(BDC)] n (2) [H2bibzim=2,2'-bibenzimidazole, BDC=1,4-benzenedicarboxylate] have been synthesized under solvothermal conditions and structurally characterized. Both 1 and 2 are constructed from infinite neutral zigzag-like one-dimensional (1D) chains. The ?-? interactions and interchain hydrogen-bonding interactions further extend the 1D arrangement to generate a 3D supramolecular architecture for 1 and 2. Both complexes have high thermal stability and display strong blue fluorescent emissions in the solid state upon photo-excitation at 365 nm at room temperature. They are the first two examples that 2,2'-bibenzimidazole has been introduced into the d 1 coordination polymeric framework

2005-01-01

256

Critical temperature of the deconfining phase transition in (2+1)d Georgi-Glashow model  

International Nuclear Information System (INIS)

We find the temperature of the phase transition in the (2+1)d Georgi-Glashow model. The critical temperature is shown to depend on the gauge coupling and on the ratio of Higgs and gauge boson masses. In the BPS limit of light Higgs the previous result by Dunne, Kogan, Kovner, and Tekin is reproduced. (author)

2003-01-01

257

1-D slab solidification TOPAZ2D comparison to analytical solution  

Energy Technology Data Exchange (ETDEWEB)

The objective of this project was to compare the numerical simulation of a 1-D slab solidification problem to the analytical solution found in Carslaw and Jaeger (1980), using absolute error as the basis of comparison. Three time steps, four element densities and two methods of accounting for latent heat produced a total of twenty-four data sets.

Smith, J.

1992-10-01

258

Nonlinear Control of Absorption in Graphene-based 1D Photonic Crystal  

CERN Multimedia

Perfect, narrow-band absorption is achieved in an asymmetric 1D photonic crystal with a monolayer graphene defect. Thanks to the large third order nonlinearity of graphene and field localization in the defect layer we demonstrate the possibility to achieve controllable, saturable absorption for the pump frequency.

Vincenti, M A; Grande, M; D'Orazio, A; Scalora, M

2013-01-01

259

TBC1D24, an ARF6-interacting protein, is mutated in familial infantile myoclonic epilepsy.  

UK PubMed Central (United Kingdom)

Idiopathic epilepsies (IEs) are a group of disorders characterized by recurrent seizures in the absence of detectable brain lesions or metabolic abnormalities. IEs include common disorders with a complex mode of inheritance and rare Mendelian traits suggesting the occurrence of several alleles with variable penetrance. We previously described a large family with a recessive form of idiopathic epilepsy, named familial infantile myoclonic epilepsy (FIME), and mapped the disease locus on chromosome 16p13.3 by linkage analysis. In the present study, we found that two compound heterozygous missense mutations (D147H and A509V) in TBC1D24, a gene of unknown function, are responsible for FIME. In situ hybridization analysis revealed that Tbc1d24 is mainly expressed at the level of the cerebral cortex and the hippocampus. By coimmunoprecipitation assay we found that TBC1D24 binds ARF6, a Ras-related family of small GTPases regulating exo-endocytosis dynamics. The main recognized function of ARF6 in the nervous system is the regulation of dendritic branching, spine formation, and axonal extension. TBC1D24 overexpression resulted in a significant increase in neurite length and arborization and the FIME mutations significantly reverted this phenotype. In this study we identified a gene mutation involved in autosomal-recessive idiopathic epilepsy, unveiled the involvement of ARF6-dependent molecular pathway in brain hyperexcitability and seizures, and confirmed the emerging role of subtle cytoarchitectural alterations in the etiology of this group of common epileptic disorders.

Falace A; Filipello F; La Padula V; Vanni N; Madia F; De Pietri Tonelli D; de Falco FA; Striano P; Dagna Bricarelli F; Minetti C; Benfenati F; Fassio A; Zara F

2010-09-01

260

Hamiltonian formulation of the N=1 D=10 supergravity coupled to super Yang-Mills theory  

Energy Technology Data Exchange (ETDEWEB)

The authors derive in full details the Hamiltonian formulation of the N = 1D = 10 supergravity coupled to super Yang-Mills theory. In particular, they present the explicit form of the first class constraints and compute the constraints gauge algebra.

Campos, R.D.A.; Fisch, J.M.L. (Universite Libre de Bruxelles (Belgium))

1988-01-01

 
 
 
 
261

Effective potential in N=1, d=4 supergravity coupled to the Volkov-Akulov field  

International Nuclear Information System (INIS)

The only-loop effective potential for N=1, d=4 supergravity theory coupled to the Volkov-Akulov field is calculated. Then it is shown that after an ajustment of some parameters the local supersymmetry is dynamically broken and as a consequence the gravitino acquires mass. (Author)

1984-01-01

262

Minimal representations of supersymmetry and 1D N-extended ?-models  

International Nuclear Information System (INIS)

We discuss the minimal representations of the 1D N-Extended Supersymmetry algebra (the Z2-graded symmetry algebra of the Supersymmetric Quantum Mechanics) linearly realized on a finite number of fields depending on a real parameter t, the time. Their knowledge allows to construct one-dimensional sigma-models with extended off-shell supersymmetries without using superfields (author)

2008-01-01

263

Clifford algebras and the minimal representations of the 1D N-extended supersymmetry algebra  

International Nuclear Information System (INIS)

The Atiyah-Bott-Shapiro classification of the irreducible Clifford algebra is used to derive general properties of the minimal representations of the 1D N-Extended Supersymmetry algebra (the Z2-graded symmetry algebra of the Supersymmetric Quantum Mechanics) linearly realized on a finite number of fields depending on a real parameter t, the time. (author)

2008-01-01

264

Design of a potent CD1d-binding NKT cell ligand as a vaccine adjuvant  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The glycolipid ?-galactosylceramide (?-GalCer) has been shown to bind CD1d molecules to activate invariant natural killer T (iNKT) cells, and subsequently induce activation of various immune-competent cells, including dendritic cells, thereby providing a significant adjuvant effect for various vacci...

Li, Xiangming; Fujio, Masakazu; Imamura, Masakazu; Wu, Douglass; Vasan, Sandhya; Wong, Chi-Huey; Ho, David D.; Tsuji, Moriya

265

Non-linear waves in plasmas of lower dimensionality: 1-D systems  

Energy Technology Data Exchange (ETDEWEB)

A theory is presented for the elementary non-linear excitation of a 1-D electron gas in a uniform background of positive charge. A simple non-linear hydrodynamic model is used to describe the dynamics of the electrons. The non-linear waves are found to be described by a Korteweg-De Vries equation.

Nerses, A.; Kunhardt, E.E. [Stevens Institute of Technology, Hoboken, NJ (United States)

1995-12-31

266

Probing the dispersion properties of 1D nanophotonic waveguides with far-field Fourier optics  

DEFF Research Database (Denmark)

We present an advanced Fourier space imaging technique to probe guided light in nanophotonic structures with an effective numerical aperture of 2.5. This superresolution technique allows us to successfully investigate the dispersive properties of 1D nanowaveguides such as photonic crystal W1 waveguides, photonic wire, slot waveguides and couplers.

Le Thomas, N.; Jágerská, J.

2008-01-01

267

Medulloblastoma expresses CD1d and can be targeted for immunotherapy with NKT cells.  

Science.gov (United States)

Medulloblastoma (MB) is the most common malignant brain tumor of childhood. Current therapies are toxic and not always curative that necessitates development of targeted immunotherapy. However, little is known about immunobiology of this tumor. In this study, we show that MB cells in 9 of 20 primary tumors express CD1d, an antigen-presenting molecule for Natural Killer T cells (NKTs). Quantitative RT-PCR analysis of 61 primary tumors revealed an elevated level of CD1d mRNA expression in a molecular subgroup characterized by an overactivation of Sonic Hedgehog (SHH) oncogene compared with Group 4. CD1d-positive MB cells cross-presented glycolipid antigens to activate NKT-cell cytotoxicity. Intracranial injection of NKTs resulted in regression of orthotopic MB xenografts in NOD/SCID mice. Importantly, the numbers and function of peripheral blood type-I NKTs were preserved in MB patients. Therefore, CD1d is expressed on tumor cells in a subset of MB patients and represents a novel target for immunotherapy. PMID:23891738

Liu, Daofeng; Song, Liping; Brawley, Vita S; Robison, Nathan; Wei, Jie; Gao, Xiuhua; Tian, Gengwen; Margol, Ashley; Ahmed, Nabil; Asgharzadeh, Shahab; Metelitsa, Leonid S

2013-06-18

268

Mapping out the quasi-condensate transition through the 1D-3D dimensional crossover  

Digital Repository Infrastructure Vision for European Research (DRIVER)

By measuring the density fluctuations in a highly elongated weakly interacting Bose gas, we observe and quantify the transition from the ideal gas to a quasi-condensate regime throughout the dimensional crossover from a purely 1D to an almost 3D gas. We show that that the entire transition region an...

Armijo, Julien; Jacqmin, Thibaut; Kheruntsyan, Karen; Bouchoule, Isabelle

269

A simple 1D model with thermomechanical coupling for superelastic SMAs  

International Nuclear Information System (INIS)

This paper presents an outline for a new uniaxial model for shape memory alloys that accounts for thermomechanical coupling. The coupling provides an explanation of the dependence of SMA behavior on the loading rate. 1D simulations are carried in Matlab using simple finite-difference discretization of the mechanical and thermal equations.

2010-06-01

270

Clifford algebras and the minimal representations of the 1D N-extended supersymmetry algebra  

Energy Technology Data Exchange (ETDEWEB)

The Atiyah-Bott-Shapiro classification of the irreducible Clifford algebra is used to derive general properties of the minimal representations of the 1D N-Extended Supersymmetry algebra (the Z{sub 2}-graded symmetry algebra of the Supersymmetric Quantum Mechanics) linearly realized on a finite number of fields depending on a real parameter t, the time. (author)

Toppan, Francesco [Centro Brasileiro de Pesquisas Fisicas (CBPF), Rio de Janeiro, RJ (Brazil)]. E-mail: toppan@cbpf.br

2008-07-01

271

Minimal representations of supersymmetry and 1D N-extended {sigma}-models  

Energy Technology Data Exchange (ETDEWEB)

We discuss the minimal representations of the 1D N-Extended Supersymmetry algebra (the Z{sub 2}-graded symmetry algebra of the Supersymmetric Quantum Mechanics) linearly realized on a finite number of fields depending on a real parameter t, the time. Their knowledge allows to construct one-dimensional sigma-models with extended off-shell supersymmetries without using superfields (author)

Toppan, Francesco

2008-07-01

272

Phase structure of (2+1)d strongly coupled lattice gauge theories  

CERN Document Server

We study the chiral phase transition in (2+1)d strongly coupled U(N) lattice gauge theories with staggered fermions. We show with high precision simulations performed directly in the chiral limit that these models undergo a Berezinski-Kosterlitz-Thouless (BKT) transition. We also show that this universality class is unaffected even in the large N limit.

Strouthos, C G

2003-01-01

273

TAU: A 1D radiative transfer code for transmission spectroscopy of extrasolar planet atmospheres  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The tau code is a 1D line-by-line radiative transfer code, which is generally applicable for modelling transmission spectra of close-in extrasolar planets. The inputs are the assumed temperature-pressure pro le of the planetary atmosphere, the continuum absorption coefficients and the absorption cro...

Hollis, MDJ; Tessenyi, M; Tinetti, G

274

Chronotopic Lyapunov analysis; 1, a comprehensive characterization of 1D systems  

CERN Multimedia

Instabilities in 1D spatially extended systems are studied with the aid of both temporal and spatial Lyapunov exponents. A suitable representation of the spectra allows a compact description of all the possible disturbances in tangent space. The analysis is carried out for chaotic and periodic spatiotemporal patterns. Singularities of the spectra and localization properties of the associated Lyapunov vectors are discussed.

Lepri, S; Torcini, A; Lepri, Stefano; Politi, Antonio; Torcini, Alessandro

1995-01-01

275

A fast sonochemical method to prepare 1D and 3D nanostructures of bismuth sulfide  

Scientific Electronic Library Online (English)

Full Text Available Abstract in portuguese Nesse trabalho, um método sonoquímico de síntese de nanoestruturas de sulfeto de bismuto em 1D e 3D foi desenvolvido e comparado com uma rota sintética empregando aquecimento sob refluxo. O método sonoquímico monstrou ser mais rápido e eficiente na obtenção de nanoestruturas com alta homogeneidade morfológica. A forma e qualidade dos nanocristais foram dependentes do tipo de solvente empregado na síntese. Superestruturas em 3D semelhantes a flores foram obtidas (more) quando etileno glicol puro foi utilizado como solvente, enquanto estruturas em 1D na forma de nanobastões foram obtidas quando utilizada uma mistura de dimetilsulfóxido e etileno como solvente. Abstract in english In this work, a sonochemical method to synthesize nanostructures of bismuth sulfide in 1D and 3D framework was developed and compared with a synthetic route with heating under reflux. The sonochemical method showed to be faster and more efficient than refluxing method to obtain nanostructures with high morphological homogeneity. Form and quality of the nanocrystals were dependent on the type of solvent employed in the synthesis procedure. 3D flower-like superstructures we (more) re obtained when ethylene glycol was used as solvent, while 1D nanorods were obtained when a mixture of dimethyl sulfoxide and ethylene glycol was used as solvent.

Mesquita, Paulo R. R.; Almeida, Jorge S.; Teixeira, Leonardo S. G.; Silva, Antônio F. da; Silva, Luciana A.

2013-02-01

276

1-D and 2D-NMR assignments of nigricin from Iris imbricata  

Directory of Open Access Journals (Sweden)

Full Text Available Ethanolic crude extract of I. imbricata Lindl. (Iridaceae) was subjected to column chromatography on silica gel with varying portions of MeOH: CHCl3. Nigicin (irisolone) was isolated and its identification carried out by IR, UV, MS, 1-D and 2-D NMR spectroscopy

Seyed Abdul Majid Ayatollahi; Mahmood Reza Moein; Farzad Kobarfard; Shama Nasim; Muhammad Iqbal Choudhary

2005-01-01

277

The structure of 1D CuI crystals inside SWNTs  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Citation: Kiselev, N. A. et al. (2008). 'The structure of 1D CuI crystals inside SWNTs', Journal of Microscopy, 232(2), 335-342. [The definitive version of the article is available at http://www3.interscience.wiley.com/journal/121496577/abstract]. © 2008 the Authors.

Kiselev, N. A.; Zakalyukin, R. M.; Zhigalina, O. M.; Grobert, N.; Kumskov, A. S.

278

Comparison between 3D and 1D simulations of a regenerative blower for fuel cell applications  

International Nuclear Information System (INIS)

Highlights: ? A hydrogen recirculation blower for automotive fuel cells applications is studied. ? A 3D CFD analysis has been carried out to better understand the internal flows of the machine. ? The CFD results are compared to a 1D model set up by the authors in previous works. ? The main hypotheses put forward for the theoretical 1D model are compatible with the 3D analysis. - Abstract: A 3D Computational Fluid Dynamics (CFD) analysis has been carried out to better understand the internal fluid dynamics of a regenerative blower used for hydrogen recirculation in a Proton Exchange Membrane (PEM), Fuel Cell (FC) utilized for automotive applications. The obtained results are used to highlight the motion of the fluid in the vanes and in the side channel of the machine and to verify the main hypotheses put forward concerning the theoretical 1D model set up by the authors in previous works on the basis of the momentum exchange theory. Finally, the CFD analysis has been used to point out the effect of the slope of the vanes on the performance of the regenerative blower, and the results have been compared with those obtained using of the 1D model.

2012-01-01

279

Non-generic blow-up solutions for the critical focusing NLS in 1-D  

Digital Repository Infrastructure Vision for European Research (DRIVER)

We consider the L-2-critical focusing non-linear Schrodinger equation in 1 + 1d. We demonstrate the existence of a large set of initial data close to the ground state soliton resulting in the pseudo-conformal type blow-up behavior. More specifically, we prove a version of a conjecture of Perelman, e...

Krieger, Joachim; Schlag, W.

280

Glycosylphosphatidylinositol-specific, CD1d-restricted T cells in paroxysmal nocturnal hemoglobinuria.  

UK PubMed Central (United Kingdom)

The mechanism of bone marrow failure (BMF) in paroxysmal nocturnal hemoglobinuria (PNH) is not yet known. Because in PNH the biosynthesis of the glycolipid molecule glycosylphosphatidylinositol (GPI) is disrupted in hematopoietic stem and progenitor cells by a somatic mutation in the PIG-A gene, BMF might result from an autoimmune attack, whereby T cells target GPI in normal cells, whereas PIG-A mutant GPI-negative cells are spared. In a deliberate test of this hypothesis, we have demonstrated in PNH patients the presence of CD8(+) T cells reactive against antigen-presenting cells (APCs) loaded with GPI. These T cells were significantly more abundant in PNH patients than in healthy controls; their reactivity depended on CD1d expression and they increased upon coculture with CD1d-expressing, GPI-positive APCs. In GPI-specific T cells captured by CD1d dimer technology, we identified, through global T-cell receptor ? (TCR?) analysis, an invariant TCRV?21 sequence, which was then found at frequencies higher than background in the TCR repertoire of 6 of 11 PNH patients. Thus, a novel, autoreactive, CD1d-restricted, GPI-specific T-cell population, enriched in an invariant TCR? chain, is expanded in PNH patients and may be responsible for BMF in PNH.

Gargiulo L; Papaioannou M; Sica M; Talini G; Chaidos A; Richichi B; Nikolaev AV; Nativi C; Layton M; de la Fuente J; Roberts I; Luzzatto L; Notaro R; Karadimitris A

2013-04-01

 
 
 
 
281

Glycosylphosphatidylinositol-specific, CD1d-restricted T cells in paroxysmal nocturnal hemoglobinuria.  

Science.gov (United States)

The mechanism of bone marrow failure (BMF) in paroxysmal nocturnal hemoglobinuria (PNH) is not yet known. Because in PNH the biosynthesis of the glycolipid molecule glycosylphosphatidylinositol (GPI) is disrupted in hematopoietic stem and progenitor cells by a somatic mutation in the PIG-A gene, BMF might result from an autoimmune attack, whereby T cells target GPI in normal cells, whereas PIG-A mutant GPI-negative cells are spared. In a deliberate test of this hypothesis, we have demonstrated in PNH patients the presence of CD8(+) T cells reactive against antigen-presenting cells (APCs) loaded with GPI. These T cells were significantly more abundant in PNH patients than in healthy controls; their reactivity depended on CD1d expression and they increased upon coculture with CD1d-expressing, GPI-positive APCs. In GPI-specific T cells captured by CD1d dimer technology, we identified, through global T-cell receptor ? (TCR?) analysis, an invariant TCRV?21 sequence, which was then found at frequencies higher than background in the TCR repertoire of 6 of 11 PNH patients. Thus, a novel, autoreactive, CD1d-restricted, GPI-specific T-cell population, enriched in an invariant TCR? chain, is expanded in PNH patients and may be responsible for BMF in PNH. PMID:23372165

Gargiulo, Lucia; Papaioannou, Maria; Sica, Michela; Talini, Giulia; Chaidos, Aristeidis; Richichi, Barbara; Nikolaev, Andrei V; Nativi, Cristina; Layton, Mark; de la Fuente, Josu; Roberts, Irene; Luzzatto, Lucio; Notaro, Rosario; Karadimitris, Anastasios

2013-01-31

282

Combined crossed beam and theoretical studies of the C(1D) + CH4 reaction.  

UK PubMed Central (United Kingdom)

The reaction involving atomic carbon in its first electronically excited state (1)D and methane has been investigated in crossed molecular beam experiments at a collision energy of 25.3 kJ mol(-1). Electronic structure calculations of the underlying potential energy surface (PES) and Rice-Ramsperger-Kassel-Marcus (RRKM) estimates of rates and branching ratios have been performed to assist the interpretation of the experimental results. The reaction proceeds via insertion of C((1)D) into one of the C-H bonds of methane leading to the formation of the intermediate HCCH(3) (methylcarbene or ethylidene), which either decomposes directly into the products C(2)H(3) + H or C(2)H(2) + H(2) or isomerizes to the more stable ethylene, which in turn dissociates into C(2)H(3) + H or H(2)CC + H(2). The experimental results indicate that the H-displacement and H(2)-elimination channels are of equal importance and that for both channels the reaction mechanism is controlled by the presence of a bound intermediate, the lifetime of which is comparable to its rotational period. On the contrary, RRKM estimates predict a very short lifetime for the insertion intermediate and the dominance of the H-displacement channel. It is concluded that the reaction C((1)D) + CH(4) cannot be described statistically and a dynamical treatment is necessary to understand its mechanism. Possibly, nonadiabatic effects are responsible for the discrepancies, as triplet and singlet PES of methylcarbene cross each other and intersystem crossing is possible. Similarities with the photodissociation of ethylene and with the related reactions N((2)D) + CH(4), O((1)D) + CH(4) and S((1)D) + CH(4) are also commented on.

Leonori F; Skouteris D; Petrucci R; Casavecchia P; Rosi M; Balucani N

2013-01-01

283

The D1-D2 region of the large subunit ribosomal DNA as barcode for ciliates.  

UK PubMed Central (United Kingdom)

Ciliates are a major evolutionary lineage within the alveolates, which are distributed in nearly all habitats on our planet and are an essential component for ecosystem function, processes and stability. Accurate identification of these unicellular eukaryotes through e.g. microscopy or mating type reactions is reserved to few specialists. To satisfy the demand for a DNA barcode for ciliates, which meets the standard criteria for DNA barcodes defined by the Consortium for the Barcode of Life (CBOL), we here evaluated the D1-D2 region of the ribosomal DNA large subunit (LSU-rDNA). Primer universality for the phylum Ciliophora was tested in silico with available database sequences as well as in the laboratory with 73 ciliate species, which represented nine out of twelve ciliate classes. Primers tested in this study were successful for all tested classes. To test the ability of the D1-D2 region to resolve conspecific and congeneric sequence divergence, 63 Paramecium strains were sampled from 24 mating species. The average conspecific D1-D2 variation was 0.18% whereas congeneric sequence divergence averaged 4.83%. In pairwise genetic distance analyses, we identified a D1-D2 sequence-divergence of < 0.6% as an ideal threshold to discriminate Paramecium species. Using this definition, only 3.8% of all conspecific and 3.9% of all congeneric sequence comparisons had the potential of false assignments. Neighbor Joining analyses inferred monophyly for all taxa but for two P. octaurelia strains. Here, we present a protocol for easy DNA amplification of single cells and voucher deposition. In conclusion, the presented data pinpoint the D1-D2 region as an excellent candidate for an official CBOL barcode for ciliated protists. This article is protected by copyright. All rights reserved.

Stoeck T; Przybos E; Dunthorn M

2013-10-01

284

Application of parallel imaging to fMRI at 7 Tesla utilizing a high 1D reduction factor.  

Science.gov (United States)

Gradient-echo EPI, blood oxygenation level-dependent (BOLD) functional MRI (fMRI) using parallel imaging (PI) is demonstrated at 7 Tesla with 16 channels, a fourfold 1D reduction factor (R), and fourfold maximal aliasing. The resultant activation detection in finger-tapping fMRI studies was robust, in full agreement with expected activation patterns based on prior knowledge, and with functional maps generated from full field of view (FOV) coverage of k-space using segmented acquisition. In all aspects the functional maps acquired with PI outperformed segmented coverage of full k-space. With a 1D R of 4, fMRI activation based on PI had higher statistical significance, up to 1.6-fold in an individual case and 1.25+/-.25 (SD) fold when averaged over six studies, compared to four-segment/full-FOV data in which the square root R reduction in the image signal-to-noise ratio (SNR) due to k-space undersampling was compensated for by acquiring additional repetitions of the undersampled k-space. When this compensation for loss in SNR was not performed, the effect of PI was determined by the ratio of physiologically induced vs. intrinsic (thermal) noise in the fMRI time series and the extent to which physiological "noise" was amplified by the use of segmentation in the full-FOV data. The results demonstrate that PI is particularly beneficial at this ultrahigh field strength, where both the intrinsic image SNR and temporal signal fluctuations due to physiological processes are large. PMID:16767760

Moeller, Steen; Van de Moortele, Pierre-Francois; Goerke, Ute; Adriany, Gregor; Ugurbil, Kâmil

2006-07-01

285

Evaluation of 1D numerical models in the prediction of distributed flow series constrained by radar altimetry data  

Science.gov (United States)

Recently, efforts have been done forward the development of methodologies to obtain flow estimates from time series of water height at virtual stations (VS - intersections between satellite tracks and water surfaces) from Topex/Poseidon (TP) and ENVISAT radar mission measurements. Relatively simple 1D propagation models such as Muskingum-Cunge (M-C) Routing Model have presented good results in the water flow propagation in Amazonian rivers. These regions suffer, in most cases, of lack of information witch constrains more accurate hydrologic and hydraulic studies. Nevertheless, these M-C models make a lot of simplification witch may cause the lost of important information that these quasi-ungaged basins can offer. This paper presents a comparison between two propagation models to the estimation of water flow series constrained by T/P and ENVISAT data. The models are: ProGUM, a Muskingum-Cunge flow routing model with diffusion-cum-dynamic wave propagation, and HEC-RAS, a well-known 1D hydrodynamic model. The verification was made in four reaches in the Negro River Basin. Each of these reaches are limited by two gauge stations, one upstream and the other one downstream. A total of five VS distributed over the reaches were analyzed. Previous studies have shown that ProGUM may yield errors less then 10% in validation phases. Here, it is demonstrated that, no much improvements can be achieved by using a more complete model capable to absorb the available data and simplifications of a M-C Model do not make significant modifications in the results of rating curve generation from satellite altimetry.

Getirana, A. C.; Bonnet, M.; Roux, E.; Rotunno, O. C.

2007-12-01

286

O(1D) kinetic study of key ozone depleting substances and greenhouse gases.  

UK PubMed Central (United Kingdom)

A key stratospheric loss process for ozone depleting substances (ODSs) and greenhouse gases (GHGs) is reaction with the O((1)D) atom. In this study, rate coefficients, k, for the O((1)D) atom reaction were measured for the following key halocarbons: chlorofluorocarbons (CFCs) CFCl3 (CFC-11), CF2Cl2 (CFC-12), CFCl2CF2Cl (CFC-113), CF2ClCF2Cl (CFC-114), CF3CF2Cl (CFC-115); hydrochlorofluorocarbons (HCFCs) CHF2Cl (HCFC-22), CH3CClF2 (HCFC-142b); and hydrofluorocarbons (HFCs) CHF3 (HFC-23), CHF2CF3 (HFC-125), CH3CF3 (HFC-143a), and CF3CHFCF3 (HFC-227ea). Total rate coefficients, kT, corresponding to the loss of the O((1)D) atom, were measured over the temperature range 217-373 K using a competitive reactive technique. kT values for the CFC and HCFC reactions were >1 × 10(-10) cm(3) molecule(-1) s(-1), except for CFC-115, and the rate coefficients for the HFCs were in the range (0.095-0.72) × 10(-10) cm(3) molecule(-1) s(-1). Rate coefficients for the CFC-12, CFC-114, CFC-115, HFC-23, HFC-125, HFC-143a, and HFC-227ea reactions were observed to have a weak negative temperature dependence, E/R ? -25 K. Reactive rate coefficients, kR, corresponding to the loss of the halocarbon, were measured for CFC-11, CFC-115, HCFC-22, HCFC-142b, HFC-23, HFC-125, HFC-143a, and HFC-227ea using a relative rate technique. The reactive branching ratio obtained was dependent on the composition of the halocarbon and the trend in O((1)D) reactivity with the extent of hydrogen and chlorine substitution is discussed. The present results are critically compared with previously reported kinetic data and the discrepancies are discussed. 2D atmospheric model calculations were used to evaluate the local and global annually averaged atmospheric lifetimes of the halocarbons and the contribution of O((1)D) chemistry to their atmospheric loss. The O((1)D) reaction was found to be a major global loss process for CFC-114 and CFC-115 and a secondary global loss process for the other molecules included in this study.

Baasandorj M; Fleming EL; Jackman CH; Burkholder JB

2013-03-01

287

O(1D) kinetic study of key ozone depleting substances and greenhouse gases.  

Science.gov (United States)

A key stratospheric loss process for ozone depleting substances (ODSs) and greenhouse gases (GHGs) is reaction with the O((1)D) atom. In this study, rate coefficients, k, for the O((1)D) atom reaction were measured for the following key halocarbons: chlorofluorocarbons (CFCs) CFCl3 (CFC-11), CF2Cl2 (CFC-12), CFCl2CF2Cl (CFC-113), CF2ClCF2Cl (CFC-114), CF3CF2Cl (CFC-115); hydrochlorofluorocarbons (HCFCs) CHF2Cl (HCFC-22), CH3CClF2 (HCFC-142b); and hydrofluorocarbons (HFCs) CHF3 (HFC-23), CHF2CF3 (HFC-125), CH3CF3 (HFC-143a), and CF3CHFCF3 (HFC-227ea). Total rate coefficients, kT, corresponding to the loss of the O((1)D) atom, were measured over the temperature range 217-373 K using a competitive reactive technique. kT values for the CFC and HCFC reactions were >1 × 10(-10) cm(3) molecule(-1) s(-1), except for CFC-115, and the rate coefficients for the HFCs were in the range (0.095-0.72) × 10(-10) cm(3) molecule(-1) s(-1). Rate coefficients for the CFC-12, CFC-114, CFC-115, HFC-23, HFC-125, HFC-143a, and HFC-227ea reactions were observed to have a weak negative temperature dependence, E/R ? -25 K. Reactive rate coefficients, kR, corresponding to the loss of the halocarbon, were measured for CFC-11, CFC-115, HCFC-22, HCFC-142b, HFC-23, HFC-125, HFC-143a, and HFC-227ea using a relative rate technique. The reactive branching ratio obtained was dependent on the composition of the halocarbon and the trend in O((1)D) reactivity with the extent of hydrogen and chlorine substitution is discussed. The present results are critically compared with previously reported kinetic data and the discrepancies are discussed. 2D atmospheric model calculations were used to evaluate the local and global annually averaged atmospheric lifetimes of the halocarbons and the contribution of O((1)D) chemistry to their atmospheric loss. The O((1)D) reaction was found to be a major global loss process for CFC-114 and CFC-115 and a secondary global loss process for the other molecules included in this study. PMID:23441917

Baasandorj, Munkhbayar; Fleming, Eric L; Jackman, Charles H; Burkholder, James B

2013-03-18

288

The effect of disease associated point mutations on 5?-reductase (AKR1D1) enzyme function  

Science.gov (United States)

The stereospecific 5?-reduction of ?4-3-ketosterols is very difficult to achieve chemically and introduces a 90° bend between ring A and B of the planar steroid. In mammals, the reaction is catalyzed by steroid 5?-reductase, a member of the aldo-keto reductase (AKR) family. The human enzyme, AKR1D1, plays an essential role in bile-acid biosynthesis since the 5?-configuration is required for the emulsifying properties of bile. Deficient 5?-reductase activity can lead to cholestasis and neo-natal liver failure and is often lethal if it remains untreated. In five patients with 5?-reductase deficiency, sequencing revealed individual, non-synonymous point mutations in the AKR1D1 gene: L106F, P133R, G223E, P198L and R261C. However, mapping these mutations to the AKR1D1 crystal structure failed to reveal any obvious involvement in substrate or cofactor binding or catalytic mechanism, and it remained unclear whether these mutations could be causal for the observed disease. We analyzed the positions of the reported mutations and found that they reside in highly conserved portions of AKR1D1 and hypothesized that they would likely lead to changes in protein folding, and hence enzyme activity. Attempts to purify the mutant enzymes for further characterization by over-expression in E.coli yielded sufficient amounts of only one mutant (P133R). This enzyme exhibited reduced Km and kcat with the bile acid intermediate ?4-cholesten-7?-ol-3-one as substrate reminiscent of uncompetitive inhibition. In addition, P133R displayed no change in cofactor affinity but was more thermolabile as judged by CD-spectroscopy. When all AKR1D1 mutants were expressed in HEK 293 cells, protein expression levels and enzyme activity were dramatically reduced. Furthermore, cycloheximide treatment revealed decreased stability of several of the mutants compared to wild type. Our data show, that all five mutations identified in patients with functional bile acid deficiency strongly affected AKR1D1 enzyme functionality and therefore may be causal for this disease.

Mindnich, Rebekka; Drury, Jason E.; Penning, Trevor M.

2011-01-01

289

Mott-insulator phases of non-locally coupled 1D dipolar Bose gases  

CERN Document Server

We analyze the Mott-insulator phases of dipolar bosonic gases placed in neighboring but unconnected 1D traps. Whereas for short-range interactions the 1D systems are independent, the non-local dipole-dipole interaction induces a direct Mott-insulator to pair-superfluid transition which significantly modifies the boundaries of the lowest Mott-insulator phases. The lowest boundary of the lowest Mott regions becomes progressively constant as a function of the hopping rate, eventually inverting its slope, leading to a re-entrant configuration which is retained in 2D. We discuss the consequences of this effect on the spatial Mott-insulator plateaux in experiments with additional harmonic confinement, showing that anti-intuitively the plateaux may become wider for increasing hopping. Our results are also applicable to non-dipolar boson-boson mixtures.

Arguelles, A

2006-01-01

290

Sulfatide attenuates experimental Staphylococcus aureus sepsis through a CD1d-dependent pathway.  

UK PubMed Central (United Kingdom)

Natural killer T (NKT) lymphocytes are implicated in the early response to microbial infection. Further, sulfatide, a myelin self-glycosphingolipid, activates a type II NKT cell subset and can modulate disease in murine models. We examined the role of NKT cells and the effect of sulfatide treatment in a murine model of Staphylococcus aureus sepsis. The lack of CD1d-restricted NKT cells did not alter survival after a lethal inoculum of S. aureus. In contrast, sulfatide treatment significantly improved the survival rate of mice with S. aureus sepsis, accompanied by decreased levels of tumor necrosis factor alpha and interleukin-6 in the blood. The protective effect of sulfatide treatment depended on CD1d but not on type I NKT cells, suggesting that activation of type II NKT cells by sulfatide has beneficial effects on the outcome of S. aureus sepsis in this model.

Kwiecinski J; Rhost S; Löfbom L; Blomqvist M; Månsson JE; Cardell SL; Jin T

2013-04-01

291

Hyperfine structures of the nd 1D(n = 3 - 8) states of 3He I  

International Nuclear Information System (INIS)

We have used the beam-foil quantum beat method to measure the hyperfine structure separations F = 3/2 - 5/2 of the 1snd 1D states (n = 3 - 8) of 3He I. We observed the single frequency modulated decay curves of the 1s2p 1P - 1snd 1D transitions for times after excitation up to 50 ns, corresponding to 4 to 5 modulation periods. The frequencies obtained (with a precision of 2 to 5%) are compared with other experiments and theory. The frequencies are determined mainly by the singlet-triplet energy separations and mixing factors for the He I D-states. The results agree with the same parameters obtained from other recent level-crossing measurements in strong magnetic field mixing of the singlet-triplet states

1981-01-01

292

Assessment of core thermo-hydrodynamic models of REFLA-1D with CCTF data  

International Nuclear Information System (INIS)

[en] In order to assess the core thermo-hydrodynamic models of REFLA-1D/MODE3, which is the latest version of REFLA-1D, several calculations of the core thermo-hydrodynamics have been performed for the CCTF Core-I series tests. The measured initial and boundary conditions were used for these calculations. The calculational results showed that the water accumulation model of Case 2 could predict the CCTF results fairly well as it could for the JAERI small scale facility. The calculated results for the base case and the EM tests were in good agreement with the CCTF data. The parameter effects, such as system pressure, initial clad temperature, Acc injection rate, LPCI injection rate and initial down-comer wall temperature, were predicted correctly, except for the high system pressure and the high LPCI injection rate tests. (author)

1983-01-01

293

Multi-centered D1-D5 solutions at finite B-moduli  

CERN Multimedia

We study the fate of two-centered D1-D5 systems on T^4 away from the singular supergravity point in the moduli space. We do this by considering a background D1-D5 black hole with a self-dual B-field moduli turned on and treating the second center in the probe limit in this background. We find that in general marginal bound states at zero moduli become metastable at finite B-moduli, demonstrating a breaking of supersymmetry. However, we also find evidence that when the charges of both centers are comparable, the effects of supersymmetry breaking become negligible. We show that this effect is independent of string coupling and thus it should be possible to reproduce this in the CFT at weak coupling. We comment on the implications for the fuzzball proposal.

Chowdhury, Borun D

2013-01-01

294

Magnetic Anticrossing of 1D Subbands in Coupled Ballistic Double Quantum Wires  

Energy Technology Data Exchange (ETDEWEB)

We study the low-temperature in-plane magnetoconductance of vertically coupled double quantum wires. Using a novel flip-chip technique, the wires are defined by two pairs of mutually aligned split gates on opposite sides of a s 1 micron thick AlGaAs/GaAs double quantum well heterostructure. We observe quantized conductance steps due to each quantum well and demonstrate independent control of each ID wire. A broad dip in the magnetoconductance at -6 T is observed when a magnetic field is applied perpendicular to both the current and growth directions. This conductance dip is observed only when 1D subbands are populated in both the top and bottom constrictions. This data is consistent with a counting model whereby the number of subbands crossing the Fermi level changes with field due to the formation of an anticrossing in each pair of 1D subbands.

BLOUNT,MARK A.; MOON,JEONG-SUN; SIMMONS,JERRY A.; LYO,SUNGKWUN K.; WENDT,JOEL R.; RENO,JOHN L.

2000-07-13

295

Highly conductive and flexible paper of 1D silver-nanowire-doped graphene.  

UK PubMed Central (United Kingdom)

A novel architecture of graphene paper is proposed to consist of "1D metallic nanowires/defect-free graphene sheets". Highly conductive and flexible papers of 1D silver nanowires (Ag NWs) and chemical vapor deposition (CVD) graphene sheets as an example were fabricated by a simple filtration method. CVD graphene paper possesses much higher electrical conductivity of 1097 S/cm, compared with other reported carbon-related papers (graphene, carbon nanotube, etc.). With the addition of Ag NWs to form Ag NWs/graphene paper, the electrical conductivity is further improved up to 3189 S/cm, even higher than ?2000 S/cm of bulk graphite. Ag NWs/graphene papers have very good flexibility with the only <5% loss of electrical conductivity over 500 times mechanical bending. Highly conductive composite papers have potential in high-performance, flexible energy conversion and storage devices.

Chen J; Bi H; Sun S; Tang Y; Zhao W; Lin T; Wan D; Huang F; Zhou X; Xie X; Jiang M

2013-02-01

296

Quantitative Multiscale Analysis using Different Wavelets in 1D Voice Signal and 2D Image  

Directory of Open Access Journals (Sweden)

Full Text Available Mutiscale analysis represents multiresolution scrutiny of a signal to improve its signal quality. Multiresolution analysis of 1D voice signal and 2D image is conducted using DCT, FFT and different wavelets such as Haar, Deubachies, Morlet, Cauchy, Shannon, Biorthogonal, Symmlet and Coiflet deploying the cascaded filter banks based decomposition and reconstruction. The outstanding quantitative analysis of the specified wavelets is done to investigate the signal quality, mean square error, entropy and peak-to-peak SNR at multiscale stage-4 for both 1D voice signal and 2D image. In addition, the 2D image compression performance is significantly found 93.00% in DB-4, 93.68% in bior-4.4, 93.18% in Sym-4 and 92.20% in Coif-2 during the multiscale analysis.

Niraj Shakhakarmi

2012-01-01

297

Production of O(1D) from dissociative recombination of O/sub 2/(+)  

Energy Technology Data Exchange (ETDEWEB)

The results of large scale ab initio calculations of the rates for production of O(1D) by dissociative combination of O2(+) are presented for electron temperatures in the range 100 to 3000 K. A 1-delta-u state is the dominant dissociative route from v = 0 and a 3-sigma-u(-) state is the most important route from v = 1 and v = 2. The calculated total rate for O(1D) production from v = 0 is 2.21(+0.21,-0.24) x 10(-7) x (T sub e/300) exp -.46 near room temperature. The v = 1 and v = 2 rates are about 17% and 47% smaller respectively, than the v = 0 rate at 300 K.

Guberman, S.L.

1987-01-01

298

FPGA Implementation of Efficient VLSI Architecture for Fixed Point 1-D DWT Using Lifting Scheme  

Directory of Open Access Journals (Sweden)

Full Text Available In this paper, a scheme for the design of area efficient and high speed pipeline VLSI architecture for the computation of fixed point 1-d discrete wavelet transform using lifting scheme is proposed. The main focus of the scheme is to reduce the number and period of clock cycles and efficient area with little or no overhead on hardware resources. The fixed point representation requires less hardware resources compared with floating point representation. The pipelining architecture speeds up the clock rate of DWT and reduced bit precision reduces the area required for implementation. The architecture has been coded in verilog HDL on Xilinx platform and the target FPGA device used is Virtex-II Pro family, XC2VP7-7board. The proposed scheme requires the least computing time for fixed point 1-D DWT and achieves theless area for implementation, compared with other architectures. So this architecture is realizable for real time processing of DWT computation applications.

Durga Sowjanya; K N H Srinivas; P Venkata Ganapathi

2012-01-01

299

Thermal conductivity of quasi-1D antiferromagnetic spin-chain materials  

CERN Document Server

We study the heat transport in quasi-1D spin-chain systems, a subject of current experimental and theoretical interest. The model of 1D bosonic spin excitations interacting with 3D phonons and impurities is analyzed in the limit of weak spin-lattice coupling and fast spin-boson excitations. Combined effect of the phonon and impurity scatterings yields the following spin-boson thermal conductivity behavior: kappa_s ~ T^2 at low, kappa_s ~ 1/T at intermediate, and kappa_s=const at higher temperatures, T ~ Theta_D, where Theta_D is the Debye temperature. Our results compare favorably with the existing experimental data for the spin-chain material Sr2CuO3. We predict an unusual dependence on the impurity concentration for a number of observables and propose further experiments.

Rozhkov, A V

2005-01-01

300

Experimental validation of Villain's conjecture about magnetic ordering in quasi-1D helimagnets  

Science.gov (United States)

Low-temperature magnetic susceptibility, zero-field muon spin resonance and specific heat measurements have been performed in the quasi-one-dimensional (1D) molecular helimagnetic compound Gd(hfac)3NITEt. The specific heat presents two anomalies at T0=2.19(2)K and TN=1.88(2)K, while susceptibility and zero-field muon spin resonance show anomalies only at TN=1.88(2)K. The results suggest an experimental validation of Villain's conjecture of a two-step magnetic ordering in quasi-1D XY helimagnets: the paramagnetic phase and the helical spin solid phases are separated by a chiral spin liquid, where translational invariance is broken without violation of rotational invariance.

Cinti, F.; Rettori, A.; Pini, M. G.; Mariani, M.; Micotti, E.; Lascialfari, A.; Papinutto, N.; Amato, A.; Caneschi, A.; Gatteschi, D.; Affronte, M.

2010-05-01

 
 
 
 
301

Quantitative Multiscale Analysis using Different Wavelets in 1D Voice Signal and 2D Image  

CERN Multimedia

Mutiscale analysis represents multiresolution scrutiny of a signal to improve its signal quality. Multiresolution analysis of 1D voice signal and 2D image is conducted using DCT, FFT and different wavelets such as Haar, Deubachies, Morlet, Cauchy, Shannon, Biorthogonal, Symmlet and Coiflet deploying the cascaded filter banks based decomposition and reconstruction. The outstanding quantitative analysis of the specified wavelets is done to investigate the signal quality, mean square error, entropy and peak-to-peak SNR at multiscale stage-4 for both 1D voice signal and 2D image. In addition, the 2D image compression performance is significantly found 93.00% in DB-4, 93.68% in bior-4.4, 93.18% in Sym-4 and 92.20% in Coif-2 during the multiscale analysis.

Shakhakarmi, Niraj

2012-01-01

302

Shock waves in a 1D Bose gas: from a BEC to a Tonks gas  

CERN Document Server

We analyze shock-wave solutions of the mean-field equations describing delta interacting 1D Bose gas for {\\it arbitrary}, repulsive, interaction strength. We derive a simple expression for the speed of propagation of arbitrarily shaped pulses. We use the number-conserving Bogolubov approach to verify the applicability of mean-field approach to shock wave problems in a 1D Bose-Einstein condensate (BEC). We show that quantum corrections to the dynamics of BEC shocks are likely to be negligible for white shocks. For dark shock waves quantum corrections seem to be negligible until the moment of wave breaking, which is followed by soliton production. We show that quantum corrections to dark-shock-originated solitons can be significant. We point out possible signatures of the BEC-Tonks crossover in a white shock dynamics. Our findings can be directly verified in different experimental setups.

Damski, B

2006-01-01

303

All-electrical injection and detection of a spin-polarized current using 1D conductors.  

UK PubMed Central (United Kingdom)

All-electrical control of spin transport in nanostructures has been the central interest and challenge of spin physics and spintronics. Here we demonstrate on-chip spin polarizing or filtering actions by driving the gate-defined one dimensional (1D) conductor, one of the simplest geometries for integrated quantum devices, away from the conventional Ohmic regime. Direct measurement of the spin polarization of the emitted current was performed when the momentum degeneracy was lifted, wherein both the 1D polarizer for spin injection and the analyzer for spin detection were demonstrated. The results showed that a configuration of gates and applied voltages can give rise to a tunable spin polarization, which has implications for the development of spintronic devices and future quantum information processing.

Chen TM; Pepper M; Farrer I; Jones GA; Ritchie DA

2012-10-01

304

Ferromagnetic superexchange in a 1D -[La(III)-radical]- coordination polymer.  

UK PubMed Central (United Kingdom)

The first coordination polymer of a bridging radical 1,2,3,5-dithiadiazolyl ligand is reported. Upon coordination with the La(hfac)3 fragment, the paramagnetic 4-(benzoxazol-2'-yl)-1,2,3,5-dithiadiazolyl (boaDTDA) ligand forms a one-dimensional (1D) alternating -[La(hfac)3-boaDTDA]n- polymer exhibiting ferromagnetic (FM) coupling between the radicals, mediated through the diamagnetic La(III) ion (hfac = 1,1,1,5,5,5-hexafluoroacetylacetonato).

Fatila EM; Clérac R; Rouzières M; Soldatov DV; Jennings M; Preuss KE

2013-07-01

305

Random phase approximation for the 1D anti-ferromagnetic Heisenberg model  

International Nuclear Information System (INIS)

The Hartree-Fock random phase approximation (HF-RPA) approach is applied to the one-dimensional (1D) anti-ferromagnetic Heisenberg model in the Jordan-Wigner representation. Somewhat contrary to expectation, this leads to reasonable results for spectral functions and sum rules in the symmetry-unbroken phase. In a preliminary application of self-consistent RPA to finite-size chains, strongly improved results are obtained.

2006-11-15

306

Absorption enhancement in 1D Ag/SiO2 metallic-dielectric photonic crystals  

Directory of Open Access Journals (Sweden)

Full Text Available The one-dimensional Ag/SiO2 metallic-dielectric photonic crystals (PCs) have been prepared. The absorption enhancement effect over the corresponding metal of 1D Ag/SiO2 metallic-dielectric multi-layer structures has been measured. The enhancement effect increases with the number of layers increasing. The origin of this phenomenon and its effect on the transmittance and reflectance have been discussed.

Su Chen; Yang Wang; Duanzheng Yao; Zhitang Song

2009-01-01

307

INFIL1D: a quasi-analytical model for simulating one-dimensional, constant flux infiltration  

International Nuclear Information System (INIS)

The program INFIL1D is designed to calculate approximate wetting-front advance into an unsaturated, uniformly moist, homogeneous soil profile, under constant surface-flux conditions. The code is based on a quasi-analytical method, which utilizes an assumed invariant functional relationship between reduced (normalized) flux and water content. The code uses general hydraulic property data in tabular form to simulate constant surface-flux infiltration. 10 references, 4 figures

1984-01-01

308

INFIL1D: a quasi-analytical model for simulating one-dimensional, constant flux infiltration  

Energy Technology Data Exchange (ETDEWEB)

The program INFIL1D is designed to calculate approximate wetting-front advance into an unsaturated, uniformly moist, homogeneous soil profile, under constant surface-flux conditions. The code is based on a quasi-analytical method, which utilizes an assumed invariant functional relationship between reduced (normalized) flux and water content. The code uses general hydraulic property data in tabular form to simulate constant surface-flux infiltration. 10 references, 4 figures.

Simmons, C.S.; McKeon, T.J.

1984-04-01

309

Insulin stimulation regulates AS160 and TBC1D1 phosphorylation sites in human skeletal muscle  

DEFF Research Database (Denmark)

Individuals with obesity and type 2 diabetes (T2D) are typically insulin resistant, exhibiting impaired skeletal muscle glucose uptake. Animal and cell culture experiments have shown that site-specific phosphorylation of the Rab-GTPase-activating proteins AS160 and TBC1D1 is critical for GLUT4 translocation facilitating glucose uptake, but their regulation in human skeletal muscle is not well understood.

Middelbeek, R J W; Chambers, M A

2013-01-01

310

EXTENSION OF THE 1D FOUR-GROUP ANALYTIC NODAL METHOD TO FULL MULTIGROUP  

International Nuclear Information System (INIS)

In the mid 80's, a four-group/two-region, entirely analytical 1D nodal benchmark appeared. It was readily acknowledged that this special case was as far as one could go in terms of group number and still achieve an analytical solution. In this work, we show that by decomposing the solution to the multigroup diffusion equation into homogeneous and particular solutions, extension to any number of groups is a relatively straightforward exercise using the mathematics of linear algebra.

2008-01-01

311

Reduced striatal dopamine D1-D2 receptor heteromer expression and behavioural subsensitivity in juvenile rats.  

UK PubMed Central (United Kingdom)

In adult rat striatum the dopamine D1-D2 receptor heteromer is expressed selectively in a subset of medium spiny neurons (MSNs) that coexpress the dopamine D1 and D2 receptors (D1R and D2R) as well as dynorphin (DYN) and enkephalin (ENK), with higher coexpression in nucleus accumbens (NAc) and much lower in the caudate putamen (CP). In the present study we showed that in neonatal striatal cultured neurons >90% exhibited the D1R/D2R-DYN/ENK phenotype. Similarly, in the striatum of juvenile rats (age 26-28 days) coexpression of D1R and D2R was also coincident with the expression of both DYN and ENK. Quantification of the number of striatal MSNs exhibiting coexpression of D1R and D2R in juvenile rats revealed significantly lower coexpression in NAc shell, but not core, and CP than in adult rats. However, within MSNs that coexpressed D1R and D2R, the propensity to form the D1-D2 receptor heteromer did not differ between age groups. Consistent with reduced coexpression of the D1R and D2R, juvenile rats exhibited subsensitivity to D1-D2 receptor heteromer-induced grooming following activation by SKF 83959. Given the proposed role of D1R/D2R-coexpressing MSNs in the regulation of thalamic output, and the recent discovery that these MSNs exhibit both inhibitory and excitatory capabilities, these findings suggest that the functional regulation of neurotransmission by the dopamine D1-D2 receptor heteromer within the juvenile striatum may be significantly different than in the adult.

Perreault ML; Hasbi A; Alijaniaram M; O'Dowd BF; George SR

2012-12-01

312

1D exciton band and exciton-phonon interaction in a single polymer chain  

CERN Multimedia

The excitonic luminescence of an isolated polydiacetylene polymer chain in its monomer matrix is studied by micro-photoluminescence. These chains behave as perfect 1D excitonic systems with the expected 1/sqrt{E} density of states between 5 and 50 K. The temperature dependence of the homogeneous width is quantitatively explained by interaction with longitudinal acoustic phonons of the crystal in the range of temperature explored.

Dubin, F

2002-01-01

313

A Fulling-Kuchment theorem for the 1D harmonic oscillator  

CERN Multimedia

We prove that there exists a pair of "non-isospectral" 1D semiclassical Schr\\"odinger operators whose spectra agree modulo h^\\infty. In particular, all their semiclassical trace invariants are the same. Our proof is based on an idea of Fulling-Kuchment and Hadamard's variational formula applied to suitable perturbations of the harmonic oscillator. Keywords: Inverse spectral problems, semiclassical Schr\\"odinger operators, trace invariants, Hadamard's variational formula, harmonic oscillator, Penrose mushroom, Sturm-Liouville theory.

Guillemin, Victor

2011-01-01

314

Spline in Compression Methods for Singularly Perturbed 1D Parabolic Equations with Singular Coefficients  

Directory of Open Access Journals (Sweden)

Full Text Available In this article, we discuss three difference schemes; for the numerical solution of singularity perturbed 1-D parabolic equations with singular coefficients using spline in compression. The proposed methods are of accurate and applicable to problems in both cases singular and non-singular. Stability theory of a proposed method has been discussed and numerical examples have been given in support of the theoretical results.

Ranjan K. Mohanty; Vijay Dahiya; Noopur Khosla

2012-01-01

315

Revival of ionization probability for a twice kicked 1D Rydberg atom  

Energy Technology Data Exchange (ETDEWEB)

The ionization probability for a one-dimensional (1D) Rydberg atom interacting with two short half-cycle pulses is calculated as a function of the time delay between them. The impulse and semiclassical approximations are used. The ionization probability oscillates with a Kepler period around some constant value evaluated analytically too. The oscillations exhibit the quantum-mechanical revival and depend on the orientation of the momentum transfer and the principal quantum number of the initial state.

Veilande, Rita; Bersons, Imants [Institute of Atomic Physics and Spectroscopy, University of Latvia, Raina boul. 19, Riga, LV-1586 (Latvia)

2005-01-28

316

Hawking radiation from non-extremal D1-D5 black hole via anomalies  

Energy Technology Data Exchange (ETDEWEB)

We take the method of anomaly cancellation for the derivation of Hawking radiation initiated by Robinson and Wilczek, and apply it to the non-extremal five-dimensional D1-D5 black hole in string theory. The fluxes of the electric charge flow and the energy-momentum tensor from the black hole are obtained. They are shown to match exactly with those of the two-dimensional black body radiation at the Hawking temperature.

Shin, Hyeonjoon [Center for Quantum Spacetime, Sogang University, Seoul, 121-742 (Korea, Republic of); Kim, Wontae [Department of Physics and Center for Quantum Spacetime, Sogang University, C.P.O. Box 1142, Seoul 100-611 (Korea, Republic of)

2007-06-15

317

A toy black hole S-matrix in the D1-D5 CFT  

CERN Document Server

To model the process of absorption and emission of quanta by an extremal D1-D5 black hole in the dual CFT, we consider transitions between different Ramond vacua via absorption and emission of chiral primaries. We compute the probabilities to reach different CFT states starting with a special Ramond vacuum, using techniques of the orbifold CFT. It is found that the processes involving the change of angular momentum by $k$ units are suppressed as 1/N^k

Lunin, Oleg

2012-01-01

318

Scaling of localization length of a quasi 1D system with longitudinal boundary roughness  

International Nuclear Information System (INIS)

We introduce irregularities on one of the longitudinal boundaries of a quasi 1D strip which has no bulk disorder. We calculate the localization length of such a system within the scope of tight-binding formalism and see how it behaves with the roughness introduced on the boundary and with the strip-width. We find that localization length scales with a composite one parameter. (author). 6 refs, 4 figs

1994-01-01

319

Piezo-semiconductive quasi-1D nanodevices with or without anti-symmetry.  

UK PubMed Central (United Kingdom)

The piezopotential in floating, homogeneous, quasi-1D piezo-semiconductive nanostructures under axial stress is an anti-symmetric (i.e., odd) function of force. Here, after introducing piezo-nano-devices with floating electrodes for maximum piezo-potential, we show that breaking the anti-symmetric nature of the piezopotential-force relation, for instance by using conical nanowires, can lead to better nanogenerators, piezotronic and piezophototronic devices.

Araneo R; Lovat G; Burghignoli P; Falconi C

2012-09-01

320

Piezo-semiconductive quasi-1D nanodevices with or without anti-symmetry.  

Science.gov (United States)

The piezopotential in floating, homogeneous, quasi-1D piezo-semiconductive nanostructures under axial stress is an anti-symmetric (i.e., odd) function of force. Here, after introducing piezo-nano-devices with floating electrodes for maximum piezo-potential, we show that breaking the anti-symmetric nature of the piezopotential-force relation, for instance by using conical nanowires, can lead to better nanogenerators, piezotronic and piezophototronic devices. PMID:22544730

Araneo, Rodolfo; Lovat, Giampiero; Burghignoli, Paolo; Falconi, Christian

2012-04-30

 
 
 
 
321

Coulomb drag in phase-coherent mesoscopic structures - Numerical study of disordered 1D-wires  

CERN Multimedia

We study Coulomb drag between two parallel disordered mesoscopic 1D-wires. By numerical ensemble averaging we calculate the statistical properties of the transconductance G_21 including its distribution. For wires with mutually uncorrelated disorder potentials we find that the mean value is finite, but with comparable fluctuations so that sign-reversal is possible. For identical disorder potentials the mean value and the fluctuations nare enhanced compared to the case of uncorrelated disorder.

Mortensen, N A; Jauho, A P; Mortensen, Niels Asger; Flensberg, Karsten; Jauho, Antti-Pekka

2001-01-01

322

Large frequency range of negligible transmission in 1D photonic quantum well structures  

CERN Multimedia

We show that it is possible to enlarge the range of low transmission in 1D photonic crystals by using photonic quantum well structures. If a defect is introduced in the photonic quantum well structures, defect modes with a very high quality factor may appear. The transmission of the defect mode is due to the coupling between the eigenmodes of the defect and those at the band edges of the constituent photonic crystals.

Zi, J; Zhang, C

1998-01-01

323

Transport coefficients of D1-D5-P system and the membrane paradigm  

CERN Document Server

I discuss a correspondence between string theory and the black hole membrane paradigm in the context of D1-D5-P system. By using the Kubo formula, I calculate transport coefficients of the effective string model induced by two kinds of minimal scalars. Then, I show that these transport coefficients exactly agree with the corresponding membrane transport coefficients of a five dimensional near extremal black hole with three charges.

Sasai, Yuya

2012-01-01

324

Sensorimotor function is modulated by the serotonin receptor 1d, a novel marker for gamma motor neurons.  

UK PubMed Central (United Kingdom)

Gamma motor neurons (MNs), the efferent component of the fusimotor system, regulate muscle spindle sensitivity. Muscle spindle sensory feedback is required for proprioception that includes sensing the relative position of neighboring body parts and appropriately adjust the employed strength in a movement. The lack of a single and specific genetic marker has long hampered functional and developmental studies of gamma MNs. Here we show that the serotonin receptor 1d (5-ht1d) is specifically expressed by gamma MNs and proprioceptive sensory neurons. Using mice expressing GFP driven by the 5-ht1d promotor, we performed whole-cell patch-clamp recordings of 5-ht1d::GFP? and 5-ht1d::GFP? motor neurons from young mice. Hierarchal clustering analysis revealed that gamma MNs have distinct electrophysiological properties intermediate to fast-like and slow-like alpha MNs. Moreover, mice lacking 5-ht1d displayed lower monosynaptic reflex amplitudes suggesting a reduced response to sensory stimulation in motor neurons. Interestingly, adult 5-ht1d knockout mice also displayed improved coordination skills on a beam-walking task, implying that reduced activation of MNs by Ia afferents during provoked movement tasks could reduce undesired exaggerated muscle output. In summary, we show that 5-ht1d is a novel marker for gamma MNs and that the 5-ht1d receptor is important for the ability of proprioceptive circuits to receive and relay accurate sensory information in developing and mature spinal cord motor circuits.

Enjin A; Leão KE; Mikulovic S; Le Merre P; Tourtellotte WG; Kullander K

2012-03-01

325

Solar influence on the O(1D) dayglow emission rate: Global-scale measurements by WINDII on UARS  

Science.gov (United States)

More than 130,000 emission rate profiles of the O(1D) dayglow (630 nm) were observed by WINDII during 1991-1995, which provide an unprecedented resource for studying the O(1D) layer, and related physics and chemistry in the thermosphere and ionosphere. This article describes the general properties of the O(1D) emission layer and an empirical model derived from WINDII measurements for the O(1D) emission rate as a function of the solar zenith angle and solar irradiance using the F10.7 cm flux as a proxy.

Zhang, S. P.; Shepherd, G. G.

2004-04-01

326

Implementation and Validation of a 1D Fluid Model for Collapsible Channels.  

UK PubMed Central (United Kingdom)

A 1D fluid model is implemented for the purpose of fluid-structure interaction (FSI) simulations in complex and completely collapsible geometries, particularly targeting the case of Obstructive Sleep Apnea (OSA). The fluid mechanics are solved separately from any solid mechanics, making possible the use of a highly complex and/or black-box solver for the solid mechanics. The fluid model is temporally discretized with a second-order scheme and spatially discretized with an asymmetrical fourth-order scheme that is robust in highly-uneven geometries. A completely collapsing and reopening geometry is handled smoothly using a modified area function. The numerical implementation is tested with two driven-geometry cases: 1) an inviscid analytical solution and 2) a completely closing geometry with viscous flow. Three-dimensional fluid simulations in static geometries are performed to examine the assumptions of the 1D model, and with a well-defined pressure-recovery constant the 1D model agrees well with 3D models. The model is very fast computationally, is robust, and is recommended for OSA simulations where the bulk flow pressure is primarily of interest.

Anderson PJ; Fels S; Green S

2013-09-01

327

Implementation and Performance Comparison Study of 1-D and 2-D FIR Filter using MATLAB  

Directory of Open Access Journals (Sweden)

Full Text Available FIR filters have only a finite number of terms in their impulse response. These filters have a number of advantages over the IIR filter types. FIR filter is always stable, realizable, and provides a linear phase response under specific conditions. These characteristics make FIR filters attractive to many filter designers. However, the major disadvantage of FIR filters is that the number of coefficients needed to implement a specific filter is often much larger than for IIR designs. Finite Impulse Response (FIR) filter is a filter structure that can be used to implement almost any sort of frequency response digitally. An FIR filter is usually implemented by using a series of delays, multipliers, and adders to create the filter's output. A Multirate digital signal processing is required in digital system where more than one Sampling Rate is required. This paper brings the performance comparison between the FIR designing methodologies like the 1-D, 2- D FIR Filters. In this paper 1-D, 2-D FIR filters using their operation have been implemented and simulated in the MATLAB and Simulink environment and their response has been studied in the waveforms. Simulation result shows that 2-D filter has increased computation speed as compared to 1-D, and is more efficient in reducing the noise in the signal.

Jyotsna Yadav; Arpita Bharti; Rohit Patel; Mukesh Kumar

2013-01-01

328

Using the D1D5 CFT to Understand Black Holes  

CERN Multimedia

In this dissertation, we review work presented in arXiv:0906.2015, arXiv:0907.1663, arXiv:1002.3132, arXiv:1003.2746, and arXiv:1007.2202 on the D1D5 system. We begin with some motivational material for black holes in string theory. In Chapter 2, we review the D1D5 system, including the gravity and CFT descriptions. In Chapter 3, we show how to perturbatively relax the decoupling limit in a general AdS-CFT setting. This allows one to compute the emission out of the AdS/CFT into the asymptotic flat space. In Chapter 4, we apply that formalism to some particular geometries, and exactly reproduce the emission spectrum. These geometries are interpreted as fuzzball microstates of a black hole, and the emission as the microscopic analogue of the Hawking radiation. In Chapter 5, we discuss how to deform the D1D5 CFT off of its orbifold point. In particular, we present full off-shell expressions for first-order corrections to the CFT states. One can see how high-energy states can fragment into many lower-energy state...

Avery, Steven

2010-01-01

329

Secure information embedding into 1D biomedical signals based on SPIHT.  

Science.gov (United States)

This paper proposes an encoding system for 1D biomedical signals that allows embedding metadata and provides security and privacy. The design is based on the analysis of requirements for secure and efficient storage, transmission and access to medical tests in e-health environment. This approach uses the 1D SPIHT algorithm to compress 1D biomedical signals with clinical quality, metadata embedding in the compressed domain to avoid extra distortion, digital signature to implement security and attribute-level encryption to support Role-Based Access Control. The implementation has been extensively tested using standard electrocardiogram and electroencephalogram databases (MIT-BIH Arrhythmia, MIT-BIH Compression and SCCN-EEG), demonstrating high embedding capacity (e.g. 3KB in resting ECGs, 200KB in stress tests, 30MB in ambulatory ECGs), short delays (2-3.3s in real-time transmission) and compression of the signal (by ?3 in real-time transmission, by ?5 in offline operation) despite of the embedding of security elements and metadata to enable e-health services. PMID:23707304

Rubio, Oscar J; Alesanco, Alvaro; García, José

2013-05-23

330

NMR 1D-imaging of water infiltration into mesoporous matrices.  

UK PubMed Central (United Kingdom)

It is shown that coupling nuclear magnetic resonance (NMR) 1D-imaging with the measure of NMR relaxation times and self-diffusion coefficients can be a very powerful approach to investigate fluid infiltration into porous media. Such an experimental design was used to study the very slow seeping of pure water into hydrophobic materials. We consider here three model samples of nuclear waste conditioning matrices which consist in a dispersion of NaNO(3) (highly soluble) and/or BaSO(4) (poorly soluble) salt grains embedded in a bitumen matrix. Beyond studying the moisture progression according to the sample depth, we analyze the water NMR relaxation times and self-diffusion coefficients along its 1D-concentration profile to obtain spatially resolved information on the solution properties and on the porous structure at different scales. It is also shown that, when the relaxation or self-diffusion properties are multimodal, the 1D-profile of each water population is recovered. Three main levels of information were disclosed along the depth-profiles. They concern (i) the water uptake kinetics, (ii) the salinity and the molecular dynamics of the infiltrated solutions and (iii) the microstructure of the water-filled porosities: open networks coexisting with closed pores. All these findings were fully validated and enriched by NMR cryoporometry experiments and by performing environmental scanning electronic microscopy observations. Surprisingly, results clearly show that insoluble salts enhance the water progression and thereby increase the capability of the material to uptake water.

Le Feunteun S; Diat O; Guillermo A; Poulesquen A; Podor R

2011-04-01

331

Oxygen-induced spin-polarized ferromagnetic state of a 1D CuO nanowire  

International Nuclear Information System (INIS)

With the full potential linearized augmented plane wave (FLAPW) method, we have investigated if a 1D Cu nanowire can display spin polarized phase. Interestingly, it was obtained that the oxygen has dramatic effect on the magnetic state manifesting spin polarized ferromagnetic ground state for free standing CuO wire, whereas pure unsupported 1D Cu wire has non-magnetic state. Our numerical results show that the magnetic moments of Cu and O atoms are very sensitive to the inter-atomic distance between Cu and O atoms, while the sum of magnetic moments from Cu and O atoms are almost constant in the range of plastic deformation. In addition, it was displayed that spin polarized 1D CuO nanowires were shown to have nearly half metallic features. We also extracted the yield stress of the CuO nanowires, and found that the maximum plastic deformation occurred at the inter-atomic distance of 3.8 a.u. between Cu and O atoms. In addition, the ferromagnetic CuO nanowires prefer perpendicular magnetization to the chain axis fro most Cu-O interatomic distances.

2005-01-01

332

A study on cooling efficiency using 1-d analysis code suitable for cooling system of thermoforming  

International Nuclear Information System (INIS)

[en] Thermoforming is one of the most versatile and economical processes available for polymer products, but cycle time and production cost must be continuously reduced in order to improve the competitive power of products. In this study, water spray cooling was simulated to apply to a cooling system instead of compressed air cooling in order to shorten the cycle time and reduce the cost of compressed air used in the cooling process. At first, cooling time using compressed air was predicted in order to check the state of mass production. In the following step, the ratio of removed energy by air cooling or water spray cooling among the total removed energy was found by using 1-D analysis code of the cooling system under the condition of checking the possibility of conversion from 2-D to 1-D problem. The analysis results using water spray cooling show that cycle time can be reduced because of high cooling efficiency of water spray, and cost of production caused by using compressed air can be reduced by decreasing the amount of the used compressed air. The 1-D analysis code can be widely used in the design of a thermoforming cooling system, and parameters of the thermoforming process can be modified based on the recommended data suitable for a cooling system of thermoforming

2009-01-01

333

Spin crossover in iron(III) Schiff-base 1-D chain complexes.  

Science.gov (United States)

A series of iron(III) 1-D polymeric materials of the general formula [Fe(III)(Schiff-base)(L)](BPh(4)).n(CH(3)OH) (Schiff base = N,N'-ethylenebis(salicylaldimine) (H(2)salen), N,N'-o-phenylenebis(salicylaldimine) (H(2)salophen) and N,N'-ethylenebis(acety1acetone)-2,2'-imine (H(2) acen); L = bridging di-pyridyl or di-imidazole ligand, n = 0-4) and analogues therein, have been synthesised and structurally and magnetically characterised. In this series, a range of structural motifs are observed including linear 1-D chains, hydrogen-bonded chains, a 'hybrid' 1-D chain- and -dimer compound and a hydrogen-bonded dinuclear material; all exhibit extensive intermolecular interactions. The magnetic consequences of varying both the equatorial Schiff-base ligands and axial bridging ligands have been investigated. Overall, we find that, independent of the axial bridging ligand employed, the salen equatorial ligand results in a high spin character and the acen ligand results in spin crossover character, generally with a spin transition of a gradual nature. Variations in magnetic behaviour can be rationalized, in part, in terms of the C(2)N(2) backbone conformation of the equatorial Schiff base ligand, which may either inhibit or allow a spin transition. PMID:20023945

Ross, Tamsyn M; Neville, Suzanne M; Innes, David S; Turner, David R; Moubaraki, Boujemaa; Murray, Keith S

2009-10-08

334

Spin crossover in iron(III) Schiff-base 1-D chain complexes.  

UK PubMed Central (United Kingdom)

A series of iron(III) 1-D polymeric materials of the general formula [Fe(III)(Schiff-base)(L)](BPh(4)).n(CH(3)OH) (Schiff base = N,N'-ethylenebis(salicylaldimine) (H(2)salen), N,N'-o-phenylenebis(salicylaldimine) (H(2)salophen) and N,N'-ethylenebis(acety1acetone)-2,2'-imine (H(2) acen); L = bridging di-pyridyl or di-imidazole ligand, n = 0-4) and analogues therein, have been synthesised and structurally and magnetically characterised. In this series, a range of structural motifs are observed including linear 1-D chains, hydrogen-bonded chains, a 'hybrid' 1-D chain- and -dimer compound and a hydrogen-bonded dinuclear material; all exhibit extensive intermolecular interactions. The magnetic consequences of varying both the equatorial Schiff-base ligands and axial bridging ligands have been investigated. Overall, we find that, independent of the axial bridging ligand employed, the salen equatorial ligand results in a high spin character and the acen ligand results in spin crossover character, generally with a spin transition of a gradual nature. Variations in magnetic behaviour can be rationalized, in part, in terms of the C(2)N(2) backbone conformation of the equatorial Schiff base ligand, which may either inhibit or allow a spin transition.

Ross TM; Neville SM; Innes DS; Turner DR; Moubaraki B; Murray KS

2010-01-01

335

1-D kinetic divertor gas-box simulations and development of a 2-D code  

Energy Technology Data Exchange (ETDEWEB)

We report on 1-D kinetic simulations of a gas-box divertor using the W1 collisional PIC code to compare with previous slot-divertor calculations. Two gas-box models are used: one with a uniform gas density and another where the gas is allowed to be attenuated by the plasma. We discuss initial comparisons of the kinetic W1 results with 1-D fluid theory to assess changes needed in SOL transport codes. We also present progress on the extension of W1 to two spatial dimensions. The simplest model couples adjacent magnetic field lines by an anomalous cross-field diffusion operator, but the potential is determined by 1-D ambipolar flow. We compare this model with a 2-D potential equation obtained by solving the current continuity equation, {del} {circ} J = 0. Here the cross-field current can be described by conductivity from ion-neutral collisions, anomalous toroidal momentum transport, or polarization current. Such calculations require a high level of parallel computations to be practical, and we will report on experience with the T3D computer in this regard.

Byers, J.A.; Cohen, R.H.; Rognlien, T.D. [Lawrence Livermore National Lab., CA (United States)] [and others

1996-12-31

336

Theoretical examination of o((1)d) insertion reactions to form methanediol, methoxymethanol, and aminomethanol.  

UK PubMed Central (United Kingdom)

A computational study of O((1)D) insertion reactions with methanol (CH3OH), dimethyl ether (CH3OCH3), and methyl amine (CH3NH2) was performed to guide laboratory investigations of the insertion product molecules methanediol (HOCH2OH), methoxymethanol (CH3OCH2OH), and aminomethanol (HOCH2NH2), respectively. The minimum energy and higher energy conformer geometries of the products were determined at the MP2/aug-cc-pVTZ level of theory, and CCSD(T)/aug-cc-pVTZ calculations were performed on the reactants, products, and transitions states to examine the insertion reaction energetics. Torsional barriers for internal motion in methanediol, methoxymethanol, and aminomethanol were also determined. It was found that O((1)D) insertion into the C-H bond was the most energetically favored reaction pathway, proceeding through a direct and barrierless insertion mechanism. The pathways of O((1)D) insertion into N-H or O-H bonds are also possible, though these reactions are less energetically favored, as they proceed through an association product intermediate before proceeding to the insertion products. Predictions are presented for the pure rotational spectra for the methanediol, methoxymethanol, and aminomethanol products based on the determined molecular parameters. These results provide an excellent starting point to guide laboratory spectral studies of the products.

Hays BM; Widicus Weaver SL

2013-08-01

337

Theoretical examination of o((1)d) insertion reactions to form methanediol, methoxymethanol, and aminomethanol.  

Science.gov (United States)

A computational study of O((1)D) insertion reactions with methanol (CH3OH), dimethyl ether (CH3OCH3), and methyl amine (CH3NH2) was performed to guide laboratory investigations of the insertion product molecules methanediol (HOCH2OH), methoxymethanol (CH3OCH2OH), and aminomethanol (HOCH2NH2), respectively. The minimum energy and higher energy conformer geometries of the products were determined at the MP2/aug-cc-pVTZ level of theory, and CCSD(T)/aug-cc-pVTZ calculations were performed on the reactants, products, and transitions states to examine the insertion reaction energetics. Torsional barriers for internal motion in methanediol, methoxymethanol, and aminomethanol were also determined. It was found that O((1)D) insertion into the C-H bond was the most energetically favored reaction pathway, proceeding through a direct and barrierless insertion mechanism. The pathways of O((1)D) insertion into N-H or O-H bonds are also possible, though these reactions are less energetically favored, as they proceed through an association product intermediate before proceeding to the insertion products. Predictions are presented for the pure rotational spectra for the methanediol, methoxymethanol, and aminomethanol products based on the determined molecular parameters. These results provide an excellent starting point to guide laboratory spectral studies of the products. PMID:23646865

Hays, Brian M; Widicus Weaver, Susanna L

2013-05-06

338

Computational Study and Analysis of Structural Imperfections in 1D and 2D Photonic Crystals  

Energy Technology Data Exchange (ETDEWEB)

Dielectric reflectors that are periodic in one or two dimensions, also known as 1D and 2D photonic crystals, have been widely studied for many potential applications due to the presence of wavelength-tunable photonic bandgaps. However, the unique optical behavior of photonic crystals is based on theoretical models of perfect analogues. Little is known about the practical effects of dielectric imperfections on their technologically useful optical properties. In order to address this issue, a finite-difference time-domain (FDTD) code is employed to study the effect of three specific dielectric imperfections in 1D and 2D photonic crystals. The first imperfection investigated is dielectric interfacial roughness in quarter-wave tuned 1D photonic crystals at normal incidence. This study reveals that the reflectivity of some roughened photonic crystal configurations can change up to 50% at the center of the bandgap for RMS roughness values around 20% of the characteristic periodicity of the crystal. However, this reflectivity change can be mitigated by increasing the index contrast and/or the number of bilayers in the crystal. In order to explain these results, the homogenization approximation, which is usually applied to single rough surfaces, is applied to the quarter-wave stacks. The results of the homogenization approximation match the FDTD results extremely well, suggesting that the main role of the roughness features is to grade the refractive index profile of the interfaces in the photonic crystal rather than diffusely scatter the incoming light. This result also implies that the amount of incoherent reflection from the roughened quarterwave stacks is extremely small. This is confirmed through direct extraction of the amount of incoherent power from the FDTD calculations. Further FDTD studies are done on the entire normal incidence bandgap of roughened 1D photonic crystals. These results reveal a narrowing and red-shifting of the normal incidence bandgap with increasing RMS roughness. Again, the homogenization approximation is able to predict these results. The problem of surface scratches on 1D photonic crystals is also addressed. Although the reflectivity decreases are lower in this study, up to a 15% change in reflectivity is observed in certain scratched photonic crystal structures. However, this reflectivity change can be significantly decreased by adding a low index protective coating to the surface of the photonic crystal. Again, application of homogenization theory to these structures confirms its predictive power for this type of imperfection as well. Additionally, the problem of a circular pores in 2D photonic crystals is investigated, showing that almost a 50% change in reflectivity can occur for some structures. Furthermore, this study reveals trends that are consistent with the 1D simulations: parameter changes that increase the absolute reflectivity of the photonic crystal will also increase its tolerance to structural imperfections. Finally, experimental reflectance spectra from roughened 1D photonic crystals are compared to the results predicted computationally in this thesis. Both the computed and experimental spectra correlate favorably, validating the findings presented herein.

K.R. Maskaly

2005-06-01

339

REFLA-1D/MODE3: a computer code for reflood thermo-hydrodynamic analysis during PWR-LOCA  

International Nuclear Information System (INIS)

This manual describes the REFLA-1D/MODE3 reflood system analysis code. This code can solve the core thermo-hydrodynamics under forced flooding conditions and gravity feed conditions in a system similar to FLECHT-SET Phase A. This manual describes the REFLA-1D/MODE3 models and provides application information required to utilize the code. (author)

1985-01-01

340

Nanomapping of CD1d-glycolipid complexes on THP1 cells by using simultaneous topography and recognition imaging.  

UK PubMed Central (United Kingdom)

CD1d molecule, a monomorphic major histocompatibility complex class I-like molecule, presents different types of glycolipids to invariant natural killer T (iNKT) cells that play an important role in immunity to infection and tumors, as well as in regulating autoimmunity. Here, we present simultaneous topography and recognition imaging (TREC) analysis to detect density, distribution and localization of single CD1d molecules on THP1 cells that were loaded with different glycolipids. TREC was conducted using magnetically coated atomic force microscopy tips functionalized with a biotinylated iNKT cell receptor (TCR). The recognition map revealed binding sites visible as dark spots, resulting from oscillation amplitude reduction during specific binding between iNKT TCR and the CD1d-glycolipid complex. THP1 cells were pulsed with three different glycolipids (?-GalCer, C20 and OCH12) for 4 and 16?hr. Whereas CD1d-?-GalCer and CD1d-C20:2 complexes on cellular membrane formed smaller microdomains up to ~10?000?nm(2) (dimension area), OCH12 loaded CD1d complexes presented larger clusters with a dimension up to ~30?000?nm(2). Moreover, the smallest size of recognition spots was about 25?nm, corresponding to a single CD1d binding site. TREC successfully revealed the distribution and localization of CD1d-glycolipid complexes on THP1 cell with single molecule resolution under physiological conditions.

Duman M; Chtcheglova LA; Zhu R; Bozna BL; Polzella P; Cerundolo V; Hinterdorfer P

2013-09-01

 
 
 
 
341

Pre-test parameter sensitivity analysis for the KNGR DVI performance test using a 1-D module of MARS  

International Nuclear Information System (INIS)

Pre-test analysis using a 1-D moduleof MARS 2.0 code has been performed for the KNGR (Korean Next Generation Reactor) DVI (Direct Vessel Injection) performance test facility which is a full height and 1/24.3 volume scaled separate effects test facility focusing on the identification of multi-dimensional thermal-hydraulic phenomena in the downcomer during the reflood conditions of a large break LOCA. From the steady state analyses for various test cases at the late reflood condition, the degree of major thermal-hydraulic phenomena such as ECC bypass, ECC penetration, steam condensation, and water level sweep-out are quantified. The MARS code analysis results showed that: (a) multi-dimensional flow and temperature behavior occurred in the downcomer region as expected, (b) the proximity of ECC injection to the break caused more ECC bypass and less steam condensation efficiency, (c) increasing the steam flow rate resulted in more ECC bypass and less steam condensation, and (d) the high velocity of steam flow swept-out the water in the downcomer just below the cold leg nozzle. These results are comparable with those observed in the previous tests such as UPTF and CCTF

2001-01-01

342

From a 1D Completed Scattering and Double Slit Diffraction to the Quantum-Classical Problem for Isolated Systems  

Science.gov (United States)

By probability theory the probability space to underlie the set of statistical data described by the squared modulus of a coherent superposition of microscopically distinct (sub)states (CSMDS) is non-Kolmogorovian and, thus, such data are mutually incompatible. For us this fact means that the squared modulus of a CSMDS cannot be unambiguously interpreted as the probability density and quantum mechanics itself, with its current approach to CSMDSs, does not allow a correct statistical interpretation. By the example of a 1D completed scattering and double slit diffraction we develop a new quantum-mechanical approach to CSMDSs, which requires the decomposition of the non-Kolmogorovian probability space associated with the squared modulus of a CSMDS into the sum of Kolmogorovian ones. We adapt to CSMDSs the presented by Khrennikov (Found. Phys. 35(10):1655, 2005) concept of real contexts (complexes of physical conditions) to determine uniquely the properties of quantum ensembles. Namely we treat the context to create a time-dependent CSMDS as a complex one consisting of elementary (sub)contexts to create alternative subprocesses. For example, in the two-slit experiment each slit generates its own elementary context and corresponding subprocess. We show that quantum mechanics, with a new approach to CSMDSs, allows a correct statistical interpretation and becomes compatible with classical physics.

Chuprikov, Nikolay L.

2011-09-01

343

1-D and 2-D electrophoresis protein profiles of the scorpion venom from Brotheas amazonicus  

International Nuclear Information System (INIS)

[en] Full text: Introduction: Scorpions venoms show specific neurotoxins to insect or mammals. These toxins are very important molecular tools to development of news drugs or bioinsecticides. Brotheas amazonicus scorpion is an endemic specie in Amazonian Rain Forest, but your venom do not show toxicity in humans. Information about biological specific activity on insect of this venom is not known yet. Objectives: Molecular protein toxins profiles of the venom from Brotheas amazonicus scorpion by 1-D and 2-D electrophoresis methods to detected toxins with potential biotech applications. Results: Several spots 'families' with ? 60, 70 and 80 kDa were detected in gel acidic region with pI ? 4,5 - 6 range, in the same region 1-D zimography showed proteolytic activity on gelatin and fibrinogen and proteolytic activity was inhibited by PMSF, suggesting scorpion serine proteinases. 50 kDa proteins were detected with pI ? 6,5 - 7 range. In 23 - 50 kDa gel acid region were observed some proteins. In 23 - 14 kDa gel acidic region were detected proteins with pI 4 - 7 range. 1-D Tris-tricine gel showed proteins with ? 7 kDa, suggesting scorpion neurotoxins. In gel basic region only 14 kDa proteins were observed with pI ? 9 - 10 range. Conclusion: Molecular profile of the scorpion venom from B. amazonicus showed proteins with high and low molecular masses, mainly with acidic pI. Proteolytic activity suggest serine proteinases with high molecular masses and 7 kDa proteins in B. amazonicus venom suggest scorpion neurotoxins. Purification and molecular characterization of these toxins are in course

2008-01-01

344

1-D and 2-D electrophoresis protein profiles of the scorpion venom from Brotheas amazonicus  

Energy Technology Data Exchange (ETDEWEB)

Full text: Introduction: Scorpions venoms show specific neurotoxins to insect or mammals. These toxins are very important molecular tools to development of news drugs or bioinsecticides. Brotheas amazonicus scorpion is an endemic specie in Amazonian Rain Forest, but your venom do not show toxicity in humans. Information about biological specific activity on insect of this venom is not known yet. Objectives: Molecular protein toxins profiles of the venom from Brotheas amazonicus scorpion by 1-D and 2-D electrophoresis methods to detected toxins with potential biotech applications. Results: Several spots 'families' with {approx} 60, 70 and 80 kDa were detected in gel acidic region with pI {approx} 4,5 - 6 range, in the same region 1-D zimography showed proteolytic activity on gelatin and fibrinogen and proteolytic activity was inhibited by PMSF, suggesting scorpion serine proteinases. 50 kDa proteins were detected with pI {approx} 6,5 - 7 range. In 23 - 50 kDa gel acid region were observed some proteins. In 23 - 14 kDa gel acidic region were detected proteins with pI 4 - 7 range. 1-D Tris-tricine gel showed proteins with {approx} 7 kDa, suggesting scorpion neurotoxins. In gel basic region only 14 kDa proteins were observed with pI {approx} 9 - 10 range. Conclusion: Molecular profile of the scorpion venom from B. amazonicus showed proteins with high and low molecular masses, mainly with acidic pI. Proteolytic activity suggest serine proteinases with high molecular masses and 7 kDa proteins in B. amazonicus venom suggest scorpion neurotoxins. Purification and molecular characterization of these toxins are in course.

Higa, A.M.; Noronha, M.D.N. [Universidade do Estado do Amazonas (UEA), Manaus, AM (Brazil). Rede Proteomica do Amazonas (Proteam). Lab. de Genomica e Proteomica; Rocha-Oliveira, F.; Lopez-Lozano, J.L.L. [Universidade Federal do Amazonas (UFAM), Manaus, AM (Brazil). Pos-Graduacao em Biotecnologia

2008-07-01

345

Advanced Fuel Cycle Initiative AFC-1D, AFC-1G and AFC-1H Irradiation Report  

Energy Technology Data Exchange (ETDEWEB)

The U. S. Advanced Fuel Cycle Initiative (AFCI) seeks to develop and demonstrate the technologies needed to transmute the long-lived transuranic actinide isotopes contained in spent nuclear fuel into shorter-lived fission products, thereby dramatically decreasing the volume of material requiring disposition and the long-term radiotoxity and heat load of high-level waste sent to a geologic repository. The AFC-1 irradiation experiments on transmutation fuels are expected to provide irradiation performance data on non-fertile and low-fertile fuel forms specifically, irradiation growth and swelling, helium production, fission gas release, fission product and fuel constituent migration, fuel phase equilibria, and fuel-cladding chemical interaction. Contained in this report are the to-date physics evaluations performed on three of the AFC-1 experiments; AFC-1D, AFC-1G and AFC-1H. The AFC-1D irradiation experiment consists of metallic non-fertile fuel compositions with minor actinides for potential use in accelerator driven systems and AFC-1G and AFC-1H irradiation experiments are part of the fast neutron reactor fuel development effort. These experiments are high burnup analogs to previously irradiated experiments and are to be irradiated to = 20 atom % burnup. Results of the evaluations show that AFC-1D will remain in the ATR for approximately 100 additional effective full power days (EFPDs), and AFC-1G and AFC-1H for approximately 300 additional EFPDs in order to reach the desired programmatic burnup. The specific irradiation schedule for these tests will be determined based on future physics evaluations and all results will be documented in subsequent reports.

Debra J. Utterbeck; Gray Chang

2005-09-01

346

Nonuniform flow in compound channel: A 1-D method for assessing water level and discharge distribution  

Science.gov (United States)

This paper investigates 1-D modeling of nonuniform flows in compound channels. The issue is how to accurately predict both flow depth and mean velocity in the floodplain. A new model, called "Independent Subsections Method" (ISM), is presented here. Unlike classical 1-D models that solve a dynamic equation on the total cross section, the ISM estimates the water surface profile within each subsection. This enables the water level and the subsection mean velocities to be simultaneously calculated, without priority to any variable. In opposition to the Divided Channel Method (DCM), corrected DCM or the Exchange Discharge Model, the ISM assumes independent evolution of the discharge in each subsection of the compound channel. Indeed, this method does not assume equal head loss gradients in all subsections, and it does not impose the downstream discharge distribution. The ISM consists in a set of three coupled 1-D momentum equations (written within main channel, left-hand, and right-hand floodplains) and a mass conservation equation on the total cross section. Mass and momentum exchanges at the interfaces between subsections are explicitly accounted for. This method is validated against experimental data for developing flows in straight compound channel, flows in skewed compound channel, flows in a symmetric converging or diverging compound channel, and flows in an asymmetrical compound channel with an abrupt floodplain contraction. For the 46 runs, the ISM predicts flow depth and mean velocity in the floodplain with a maximum relative error of 8% and 19%, respectively. The ISM also appears to be a useful theoretical tool to improve our understanding of physical processes governing compound channel flows.

Proust, SéBastien; Bousmar, Didier; Riviere, Nicolas; Paquier, André; Zech, Yves

2009-12-01

347

Exact Ground States for Quasi 1D Systems with Hubbard Interaction  

Directory of Open Access Journals (Sweden)

Full Text Available Using a positive semidefinite operator technique we deduced exact ground states for a modified diamond chain described by a non-integrable Hubbard model with on-site repulsion. Our results are valid for arbitrary length of the chain and strength of the Hubbard interaction. For the analyzed parameter space region of the quasi 1D chain structure we found that two flat bands are present in the bare band structure of the system, both for zero and for a fixed value of magnetic field. We obtained ground states of nonmagnetic and ferromagnetic insulator type and studied their physical properties. Using a positive semidefinite operator technique we deduced exact ground states for a modified diamond chain described by a non-integrable Hubbard model with on-site repulsion. Our results are valid for arbitrary length of the chain and strength of the Hubbard interaction. For the analyzed parameter space region of the quasi 1D chain structure we found that two flat bands are present in the bare band structure of the system, both for zero and for a fixed value of magnetic field. We obtained ground states of nonmagnetic and ferromagnetic insulator type and studied their physical properties. Using a positive semidefinite operator technique we deduced exact ground states for a modified diamond chain described by a non-integrable Hubbard model with on-site repulsion. Our results are valid for arbitrary length of the chain and strength of the Hubbard interaction. For the analyzed parameter space region of the quasi 1D chain structure we found that two flat bands are present in the bare band structure of the system, both for zero and for a fixed value of magnetic field. We obtained ground states of nonmagnetic and ferromagnetic insulator type and studied their physical properties.

E. Kovács; Zs. Gulácsi

2012-01-01

348

Monochromatic Neutron Tomography Using 1-D PSD Detector at Low Flux Research Reactor  

International Nuclear Information System (INIS)

This paper describes the monochromatic neutron tomography experiment using the 1-D Position Sensitive Neutron Detector (PSD) located at Nuclear Malaysia TRIGA MARK II Research reactor. Experimental work was performed using monochromatic neutron source from beryllium filter and HOPG crystal monochromator. The principal main aim of this experiment was to test the detector efficiency, image reconstruction algorithm and the usage of 0.5 nm monochromatic neutrons for the neutron tomography setup. Other objective includes gathering important parameters and features to characterize the system.

2008-03-17

349

Study of the 1D anisotropic Kondo necklace model at criticality via an entanglement entropy estimator  

Science.gov (United States)

We use an estimator of quantum criticality based on the entanglement entropy to discuss the ground state properties of the 1D anisotropic Kondo necklace model. We found that the T=0 phase diagram of the model is described by a critical line separating an antiferromagnetic phase from a Kondo singlet state. Moreover we calculate the conformal anomaly on the critical line and obtain that c tends to 0.5 as the thermodynamic limit is reached. Hence we conclude that these transitions belong to Ising universality class being, therefore, second order transitions instead of infinite order as claimed before.

Saguia, A.

2013-11-01

350

Numerical modeling of 1-D transient poroelastic waves in the low-frequency range  

CERN Multimedia

Propagation of transient mechanical waves in porous media is numerically investigated in 1D. The framework is the linear Biot's model with frequency-independant coefficients. The coexistence of a propagating fast wave and a diffusive slow wave makes numerical modeling tricky. A method combining three numerical tools is proposed: a fourth-order ADER scheme with time-splitting to deal with the time-marching, a space-time mesh refinement to account for the small-scale evolution of the slow wave, and an interface method to incorporate the jump conditions at interfaces. Comparisons with analytical solutions confirm the validity of this approach.

Chiavassa, Guillaume; Piraux, Joël

2007-01-01

351

Simulation and optimization of 1-D periodic dielectric nanostructures for light-trapping.  

UK PubMed Central (United Kingdom)

Light-trapping is essential to improve the performance of thin-film solar cells. In this paper, we perform a parametric optimization of 1-D square and sinusoidal grating structures that act as nanophotonic scatterers to increase light absorption in ultra-thin (10nm) solar cells. Our optimization reveals that the short-circuit current density in a device of active-layer thickness 10nm can be improved by a factor of ~5 in the presence of the scattering structure. More complex geometries allow for increased degrees of design freedom and potentially high enhancement of light absorption.

Wang P; Menon R

2012-01-01

352

Absorption profile modulation by means of 1D digital plasmonic gratings.  

UK PubMed Central (United Kingdom)

Optical simulations of 1D digital plasmonic gratings on a Silicon substrate are performed by means of the Finite Elements Method and a modal analysis. The different mechanisms of transmission of the light are elucidated. The absorption profile in Silicon can be modulated and controlled changing the geometry. Configuration maps allow to determine the different optical regimes. Surface Plasmon Polaritons and cavity-mode resonances are shown to be effectively exploitable to enhance NIR-light absorption in different shallower regions of the underlying Silicon.

Zilio P; Sammito D; Zacco G; Romanato F

2010-09-01

353

Characteristics of the FTU scrape-off layer (SOL) determined by a simple 1-D model  

International Nuclear Information System (INIS)

A simple 1-D model analytical model has been developed to determine the SOL characteristics from the parameters of the main plasma. The solutions are compared with FTU experimental data. The solutions fit quite well the experimental data and their trend. Moreover the model suggests the presence of a critical density related to the non isothermal power flux and the corresponding maximum power which can be safely removed by volumetric sinks. Differences between a limiter-like configuration and a divertor-like configuration are described

1994-01-01

354

Microfocusing transfocator for 1D and 2D compound refractive lenses.  

UK PubMed Central (United Kingdom)

An x-ray transfocator design for the combined use of 1D and 2D compound refractive lenses is described. The device includes stacks of beryllium parabolic lenses with different radii of curvature and provides microfocused x-ray beams in the 4-20 keV photon energy range. The transfocator has been implemented at the P10 Coherence Beamline of the PETRA III synchrotron at DESY, Hamburg. Results of transfocator performance and applications for coherent x-ray scattering experiments are presented.

Zozulya AV; Bondarenko S; Schavkan A; Westermeier F; Grübel G; Sprung M

2012-08-01

355

Localization and Anomalous Transport in a 1-D Soft Boson Optical Lattice  

CERN Multimedia

We study the dynamics of Bose-Einstein condensed atoms in a 1-D optical lattice potential in a regime where the collective (Josephson) tunneling energy is comparable with the on-site interaction energy, and the number of particles per lattice site is mesoscopically large. By directly imaging the motion of atoms in the lattice, we observe an abrupt suppression of atom transport through the array for a critical ratio of these energies, consistent with quantum fluctuation induced localization. Directly below the onset of localization, the frequency of the observed superfluid transport can be explained by a phonon excitation but deviates substantially from that predicted by the hydrodynamic/Gross-Pitaevskii equations.

Tuchman, A K; Chien, H; Dettmer, S; Kasevich, M A

2006-01-01

356

Binding and excitation energies of Lennard-Jones clusters in the 1/d-method  

International Nuclear Information System (INIS)

[en] We present simple estimates of the binding energies of clusters of rare-gas atoms and excitation energies of low-lying states in trimers, which are obtained by writing formally the Schroedinger equation in d dimensions and expanding its solution in powers of 1/d. Comparison with Monte Carlo calculations for Lennard-Jones clusters (Nen, Arn, Krn, Xen, n=3-7 and 13) shows good agreement, and suggests that our formulae may be used to estimate the energy of rare-gas atoms interacting through realistic potentials. (author). 24 refs, 1 fig., 2 tabs

1992-01-01

357

Controllable plasma energy bands in a 1D crystal of fractional Josephson vortices  

CERN Document Server

We consider a 1D chain of fractional vortices in a long Josephson junction with alternating $\\pm\\kappa$ phase discontinuities. Since each vortex has its own eigenfrequency, the inter-vortex coupling results in eigenmode splitting and in the formation of an oscillatory energy band for plasma waves. The band structure can be controlled at the design time by choosing the distance between vortices or \\emph{during experiment} by varying the topological charge of vortices or the bias current. Thus one can construct an artificial vortex crystal with controllable energy bands for plasmons.

Susanto, H; Kölle, D; Kleiner, R; Van Gils, S A

2004-01-01

358

Inverse problems in 1D hemodynamics on systemic networks: A sequential approach.  

UK PubMed Central (United Kingdom)

In this work, a sequential approach based on the unscented Kalman filter is applied to solve inverse problems in 1D hemodynamics, on a systemic network. For instance, the arterial stiffness is estimated by exploiting cross-sectional area and mean speed observations in several locations of the arteries. The results are compared with those ones obtained by estimating the pulse wave velocity and the Moens-Korteweg formula. In the last section, a perspective concerning the identification of the terminal models parameters and peripheral circulation (modeled by a Windkessel circuit) is presented. Copyright © 2013 John Wiley & Sons, Ltd.

Lombardi D

2013-09-01

359

Transport of a Bose Gas in 1D Disordered Lattices at the Fluid-Insulator Transition.  

UK PubMed Central (United Kingdom)

We investigate the momentum-dependent transport of 1D quasicondensates in quasiperiodic optical lattices. We observe a sharp crossover from a weakly dissipative regime to a strongly unstable one at a disorder-dependent critical momentum. In the limit of nondisordered lattices the observations suggest a contribution of quantum phase slips to the dissipation. We identify a set of critical disorder and interaction strengths for which such critical momentum vanishes, separating a fluid regime from an insulating one. We relate our observation to the predicted zero-temperature superfluid-Bose glass transition.

Tanzi L; Lucioni E; Chaudhuri S; Gori L; Kumar A; D'Errico C; Inguscio M; Modugno G

2013-09-01

360

Inelastic coulomb scattering rate of a multisubband Q1D electron gas  

Scientific Electronic Library Online (English)

Full Text Available Abstract in english We study, the Coulomb scattering lifetimes of electrons in two coupled quantum wires by calculating the quasiparticle self-energy within a multisubband model of quasi-one-dimensional (Q1D) electron system. We consider two strongly coupled quantum wires with two occupied subbands. The intrasubband and intersubband inelastic scattering rates are caculated for electrons in different subbands. Contributions of the intrasubband, intersubband plasmon excitations, as well as the (more) quasiparticle excitations are investigated. Our results show that the plasmon exictations of the first subband are the most important scattering mechanism for electrons in both subbands.

Tavares, M.; Hai, G.-Q.

1999-12-01

 
 
 
 
361

Local source tomography for Vrancea (Romania) region: minimum 1D model  

International Nuclear Information System (INIS)

[en] The Vrancea zone is characterized by a narrow, vertical focal volume of intense and persistent seismicity in the depth range of 60-220 km. The processes associated with the Vrancea earthquakes outline a final stage of continental subduction with plate detachment, still far from being understood. Our main purpose is to perform local earthquake tomography to image crustal structures in Vrancea and adjacent regions as initial reference model in 3 D tomography. The study includes updating of the existing catalogues of seismic parameter data, calculation of a minimum 1D model and correlation with the existing controlled-source data. The model is determined by a trial-and-error process, with internal non-linear (iterative) inversion procedure (program VELEST). The average velocity model parameters are obtained by minimizing the standard deviations of the travel time residuals. The P-wave travel times for 500 well-locatable events are used, merging travel time data recorded by two separate independent seismic networks: the Romanian telemetered network (17 vertical-component S-13 seismometers) and the digital accelerometers network (30 three-component K2 instruments) installed in 1996 within the joint Romanian-German cooperation programme CRC 461. Since the two networks largely overlap geographically, we calculate a common minimum 1D model that guarantees a uniform location quality and uniform phase identification for the two networks. Absolute mislocation errors for the combined networks using the minimum 1D model are calculated using quarry blast data obtained during the VRANCEA99 refraction experiment deployed in 1999 in Romania as a contribution to the CRC 461 programme. The resulted minimum 1D model and station corrections are used to relocate all the considered events and to improve the consistency in the phase identification. The station corrections obtained are correlated with the lateral velocity variations in the surface geology of the region. This paper is a preliminary contribution to the future seismic tomography study in the framework of the CALIXTO'99 project. (authors)

2000-01-01

362

Transport of a Bose Gas in 1D Disordered Lattices at the Fluid-Insulator Transition  

Science.gov (United States)

We investigate the momentum-dependent transport of 1D quasicondensates in quasiperiodic optical lattices. We observe a sharp crossover from a weakly dissipative regime to a strongly unstable one at a disorder-dependent critical momentum. In the limit of nondisordered lattices the observations suggest a contribution of quantum phase slips to the dissipation. We identify a set of critical disorder and interaction strengths for which such critical momentum vanishes, separating a fluid regime from an insulating one. We relate our observation to the predicted zero-temperature superfluid-Bose glass transition.

Tanzi, Luca; Lucioni, Eleonora; Chaudhuri, Saptarishi; Gori, Lorenzo; Kumar, Avinash; D'Errico, Chiara; Inguscio, Massimo; Modugno, Giovanni

2013-09-01

363

Simultaneous potential and circuit solution for 1D bounded plasma particle simulation codes  

Energy Technology Data Exchange (ETDEWEB)

A general second-order accurate method for solving the combined potential and circuit equations in a one-dimensional electrostatic bounded plasma PIC simulation is presented. The boundary conditions include surface charge on the electrodes, which are connected to a series RLC circuit with driving terms V(t) or l(t). The solution is obtained for planar, cylindrical, and spherical electrodes. The result is a tridiagonal matrix which is readily solved using well-known methods. The method is implemented in the codes PDPL (plasma device planar 1 D), PDC1 (cylindrical), and PDS1 (spherical).

Verboncoeur, J.P.; Vahedi, V.; Birdsall, C.K. (Univ. of California, Berkeley (United States)); Alves, M.V. (Institute for Space Research (INPE), S.J. dos Campos (Brazil))

1993-02-01

364

Simultaneous potential and circuit solution for 1D bounded plasma particle simulation codes  

International Nuclear Information System (INIS)

A general second-order accurate method for solving the combined potential and circuit equations in a one-dimensional electrostatic bounded plasma PIC simulation is presented. The boundary conditions include surface charge on the electrodes, which are connected to a series RLC circuit with driving terms V(t) or l(t). The solution is obtained for planar, cylindrical, and spherical electrodes. The result is a tridiagonal matrix which is readily solved using well-known methods. The method is implemented in the codes PDPL (plasma device planar 1 D), PDC1 (cylindrical), and PDS1 (spherical).

1993-01-01

365

Chaotic Classical Scattering and Dynamics in Oscillating 1-D Potential Wells  

CERN Document Server

We study the motion of a classical particle interacting with one, two, and finally an infinite chain of 1D square wells with oscillating depth. For a single well we find complicated scattering behavior even though there is no topological chaos due to the absence of hyperbolic periodic orbits. In contrast, for two coupled square wells there is chaotic scattering. The infinite oscillating chain yields the generic transition to chaos, with diffusion in energy and in space, as the separation between wells is increased. We briefly discuss the relevance of our results to solid state physics.

Luna-Acosta, G A; Mendoza-Galvan, A; Jung, C

2001-01-01

366

Extended scaling functions for Ising systems with dimensionality 1?d?4  

International Nuclear Information System (INIS)

Finite-size lattice Monte Carlo simulations of phase transitions in Ising systems (1?d?4) allow the determination of simple binomial scaling functions for Tc and Tc, consistent with the asymptotic behavior for the critical isotherm, the spontaneous magnetization and the zero field susceptibility, which describe quite well the scaling behavior in an extended range of the scaling variable, 0.01?|(T-Tc)/Tc|L1/??20, for all four dimensionalities. (Copyright (c) 1999 Elsevier Science B.V., Amsterdam. All rights reserved.)

1999-05-01

367

Finite-length Lyapunov exponents and conductance for quasi-1D disordered solids  

CERN Document Server

The transfer matrix method is applied to finite quasi-1D disordered samples attached to perfect leads. The model is described by structured band matrices with random and regular entries. We investigate numerically the level spacing distribution for finite-length Lyapunov exponents as well as the conductance and its fluctuations for different channel numbers and sample sizes. A comparison is made with theoretical predictions and with numerical results recently obtained with the scattering matrix approach. The role of the coupling and finite size effects is also discussed.

Kottos, T; Politi, A

1999-01-01

368

Review of Zero-D and 1-D Models of Blood Flow in the Cardiovascular System  

Directory of Open Access Journals (Sweden)

Full Text Available Abstract Background Zero-dimensional (lumped parameter) and one dimensional models, based on simplified representations of the components of the cardiovascular system, can contribute strongly to our understanding of circulatory physiology. Zero-D models provide a concise way to evaluate the haemodynamic interactions among the cardiovascular organs, whilst one-D (distributed parameter) models add the facility to represent efficiently the effects of pulse wave transmission in the arterial network at greatly reduced computational expense compared to higher dimensional computational fluid dynamics studies. There is extensive literature on both types of models. Method and Results The purpose of this review article is to summarise published 0D and 1D models of the cardiovascular system, to explore their limitations and range of application, and to provide an indication of the physiological phenomena that can be included in these representations. The review on 0D models collects together in one place a description of the range of models that have been used to describe the various characteristics of cardiovascular response, together with the factors that influence it. Such models generally feature the major components of the system, such as the heart, the heart valves and the vasculature. The models are categorised in terms of the features of the system that they are able to represent, their complexity and range of application: representations of effects including pressure-dependent vessel properties, interaction between the heart chambers, neuro-regulation and auto-regulation are explored. The examination on 1D models covers various methods for the assembly, discretisation and solution of the governing equations, in conjunction with a report of the definition and treatment of boundary conditions. Increasingly, 0D and 1D models are used in multi-scale models, in which their primary role is to provide boundary conditions for sophisticate, and often patient-specific, 2D and 3D models, and this application is also addressed. As an example of 0D cardiovascular modelling, a small selection of simple models have been represented in the CellML mark-up language and uploaded to the CellML model repository http://models.cellml.org/. They are freely available to the research and education communities. Conclusion Each published cardiovascular model has merit for particular applications. This review categorises 0D and 1D models, highlights their advantages and disadvantages, and thus provides guidance on the selection of models to assist various cardiovascular modelling studies. It also identifies directions for further development, as well as current challenges in the wider use of these models including service to represent boundary conditions for local 3D models and translation to clinical application.

Shi Yubing; Lawford Patricia; Hose Rodney

2011-01-01

369

Piezo-semiconductive quasi-1D nanodevices with or without anti-symmetry  

Energy Technology Data Exchange (ETDEWEB)

The piezopotential in floating, homogeneous, quasi-1D piezo-semiconductive nanostructures under axial stress is an anti-symmetric (i.e., odd) function of force. Here, after introducing piezo-nano-devices with floating electrodes for maximum piezo-potential, we show that breaking the anti-symmetric nature of the piezopotential-force relation, for instance by using conical nanowires, can lead to better nanogenerators, piezotronic and piezophototronic devices. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

Araneo, Rodolfo; Lovat, Giampiero [DIAEE-Electrical Engineering Division, ' ' Sapienza' ' University of Rome, Via Eudossiana 18, 00184, Rome (Italy); Burghignoli, Paolo [Department of Information Engineering, Electronics and Telecommunications, ' ' Sapienza' ' University of Rome, Via Eudossiana 18, 00184, Rome (Italy); Falconi, Christian [Department of Electronic Engineering, University of Tor Vergata, Via del Politecnico 1, 00133, Rome (Italy); CNR IDASC, Via Fosso del Cavaliere, 100, 00133 Rome (Italy)

2012-09-04

370

Silva. EDF two-phase 1D annular model of a CFB boiler furnace  

Energy Technology Data Exchange (ETDEWEB)

SILVA computer code is used for the modelling of the thermal-hydraulics and of the combustion of a coal-fired CFBC solid loop. In a first step, only the furnace is considered. The model is based on a 1D annular two phases description of the hydrodynamics. The model is based on particle mass balances and pressure drop calculations. A basic combustion model is incorporated into this model. The coal combustion is divided in two phases, the combustion of volatile matter and the heterogeneous combustion. The model has been developed within LEGO software and can be included into the global model of the solid loop developed by EDF. (author) 26 refs.

Montat, D.; Fauquet, Ph. [Electricite de France (EDF), 78 - Chatou (France). Researckh and Development Div.; Lafanechere, L.; Bursi, J.M. [Electricite de France (EDF) (France). Construction Div.

1997-01-01

371

1D Cahn-Hilliard dynamics: Ostwald ripening and application to modulated phase systems  

International Nuclear Information System (INIS)

[en] We use a family of stationary solution of the Cahn-Hilliard dynamics in order to describe the coalescence during a first order phase transition. With this analytical ansatz, we compute the characteristic time for one step of period doubling in Langer's self similar scenario for Ostwald ripening. As an application, the same ansatz is also used to compute the thermodynamically stable period of a 1D modulated phase pattern, described by a Cahn-Hilliard dynamics with long range interaction terms

2008-12-08

372

Numerical study of two-body correlation in a 1D lattice with perfect blockade  

CERN Multimedia

We compute the dynamics of excitation and two-body correlation for two-level "pseudoatoms" in a 1D lattice. We adopt a simplified model where pair excitation within a finite range is perfectly blocked. Each superatom is initially in the ground state, and then subjected to an external driving laser with Rabi frequency satisfying a Poissonian distribution, mimicking the scenario as in Rydberg gases. We find that two-body quantum correlation drops very fast with the distance between pseudoatoms. However, the total correlation decays slowly even at large distance. Our results may be useful to the understanding of Rydberg gases in the strong blockade regime.

Sun, B

2008-01-01

373

Numerical study of two-body correlation in a 1D lattice with perfect blockade  

Energy Technology Data Exchange (ETDEWEB)

We compute the dynamics of excitation and two-body correlation for two-level 'pseudoatoms' in a one-dimensional (1D) lattice. We adopt a simplified model where pair excitation within a finite range is perfectly blocked. Each superatom is initially in the ground state, and then subjected to an external driving laser with Rabi frequency satisfying a Poissonian distribution, mimicking the scenario in Rydberg gases. We find that two-body quantum correlation drops very fast with the distance between pseudoatoms. However, the total correlation decays slowly even at large distance. Our results may be useful to the understanding of Rydberg gases in the strong blockade regime.

Sun, B; Robicheaux, F [Department of Physics, Auburn University, Auburn, AL 36849 (United States)], E-mail: bzs0006@auburn.edu

2008-04-15

374

Synthesis, Characterization, and Application of 1-D Cerium Oxide Nanomaterials: A Review  

Directory of Open Access Journals (Sweden)

Full Text Available The present work provides a comprehensive overview of the recent progress of research work toward developing new one dimensional (1-D) ceria (CeO2) nanomaterials. The review has been classified into three parts: the preparation procedures with identification of the existing different dimensional ceria nanomaterials, the formation mechanisms, and an analysis of their applications. From literature survey, it is inaugurated that the fundamental structures of the ceria nanomaterials constructively dominate their properties and applications. In addition, this work will also provide a perspective on the future technical trends for the development of different dimensional CeO2 nanomaterials.

Kuen-Song Lin; Sujan Chowdhury

2010-01-01

375

Phonon-mediated superconductivity in quasi-1D Sc3CoC4  

Science.gov (United States)

The mechanism for the superconductivity observed in quasi-1D Sc3CoC4 has been investigated with density functional theory. No evidence supporting a charge density wave distortion in the superconducting state was found. Instead, the conventional phonon-mediated theory was shown to be valid. Solutions to Eliashberg equations for partitioned vibrational modes permit the characterization of important electron-phonon processes. The superconducting state is the result of interactions between the electronic structure with the lattice vibrations and the dicarbo-C2 librations.

Zhang, Chao; Tse, John S.; Tanaka, Kaori; Lin, Hai-Qing

2012-12-01

376

GNSS meteorology for severe weather - 1D, 2D and 3D solution  

Science.gov (United States)

The variability of water vapour (WV) is strongly correlated with the formation, course and dissipation of the mesoscale convective storm systems, due to the large latent heat transfers in the evaporation/condensation process. Contrary to its importance WV space and time distribution remains under sampled in both domains, especially in sparsely populated countries such as Australia. GPS meteorology currently is a very important data source for meteorology, climatology and forecasting, due to the relatively dense network of receivers, operating in the unified reference frame. Point observations of troposphere delay (1D), integrated water vapour (1D), as well as maps of these parameters (2D) are highly sensitive to building up of high amount of water vapour in the troposphere, as well as storm passage. The Kalman filter based GNSS tomography is an emerging method of reconstructing dynamically changing wet refractivity fields (3D). All types of ground based GNSS products has solid scientific foundations and are routinely estimated by major GNSS processing centres with high accuracy and low latency (ie. EGVAP AC). The forthcoming challenge of for the analyse of GNSS meteorology estimates (1D, 2D and 3D) is developing a quantifiable method to predict as well as identify location, size and severity of mesoscale convective storm system. In the course of this research several spatial and temporal filter and indicators have been developed to aid in early detection, prediction and monitoring of severe weather events using all types of GNSS meteorology by-products estimates (1D, 2D and 3D). This research presents a case study based on the analysis of an extreme convective super cell storm in the Victorian region during March 2010 using GPS tomography. Integrated Perceptible Water readings collected from MOBS stations confirmed high time resolution as well as sensitivity to incoming severe weather. Another, special measure of Refractive Index adopted for GPS tomography wet refractivity profiles, shows excessive values as a response to supercell thunderstorm formation. Finally a 2D cross section mapping the lifecycle of this severe weather event concludes a correlation between the highly dynamic spatial and temporal changes of wet refractivity modelled using 4D GPS tomography with precipitation intensities measured using weather radars.

Rohm, Witold; Manning, Toby; Yuan, Yubin; Biadeglgne, Bertukan; Choy, Sue Lynn; Zhang, Kefei

2013-04-01

377

One-Particle Spectral Properties of 1D Mott-Hubbard Insulators  

Energy Technology Data Exchange (ETDEWEB)

We use an exact {ital holon} and {ital spinon} Landau-liquid functional, which describes the holon-spinon interactions at all scattering orders, to study correlation functions of integrable multicomponent many-particle problems showing both linear and nonlinear energy bands. Motivated by recent photoemission experiments, we consider specific cases when the dominant nonlinear band terms are quadratic and apply our results to the evaluation of the half-filling 1D Hubbard model one-particle spectral functions beyond conformal field theory. {copyright} {ital 1999} {ital The American Physical Society }

Carmelo, J.M. [N.O.R.D.I.T.A., Blegdamsvej 17, DK-2100 Copenhagen O/ (Denmark); Carmelo, J.M.; Guerra, J.M. [Department of Physics, University of Evora, Apartado 94, P-7001 Evora Codex (Portugal); Lopes dos Santos, J.M. [CFP and Departamento de Fisica da Faculdade de Ciencias da Universidade do Porto Rua do Campo Alegre 687, P-4169-007 Porto (Portugal); Castro Neto, A.H. [Department of Physics, University of California, Riverside, California 92521 (United States)

1999-11-01

378

Crystal Structures of Human TBC1D1 and TBC1D4 (AS160) RabGTPase-activating Protein (RabGAP) Domains Reveal Critical Elements for GLUT4 Translocation  

Energy Technology Data Exchange (ETDEWEB)

We have solved the x-ray crystal structures of the RabGAP domains of human TBC1D1 and human TBC1D4 (AS160), at 2.2 and 3.5 {angstrom} resolution, respectively. Like the yeast Gyp1p RabGAP domain, whose structure was solved previously in complex with mouse Rab33B, the human TBC1D1 and TBC1D4 domains both have 16 {alpha}-helices and no {beta}-sheet elements. We expected the yeast Gyp1p RabGAP/mouse Rab33B structure to predict the corresponding interfaces between cognate mammalian RabGAPs and Rabs, but found that residues were poorly conserved. We further tested the relevance of this model by Ala-scanning mutagenesis, but only one of five substitutions within the inferred binding site of the TBC1D1 RabGAP significantly perturbed catalytic efficiency. In addition, substitution of TBC1D1 residues with corresponding residues from Gyp1p did not enhance catalytic efficiency. We hypothesized that biologically relevant RabGAP/Rab partners utilize additional contacts not described in the yeast Gyp1p/mouse Rab33B structure, which we predicted using our two new human TBC1D1 and TBC1D4 structures. Ala substitution of TBC1D1 Met{sup 930}, corresponding to a residue outside of the Gyp1p/Rab33B contact, substantially reduced catalytic activity. GLUT4 translocation assays confirmed the biological relevance of our findings. Substitutions with lowest RabGAP activity, including catalytically dead RK and Met{sup 930} and Leu{sup 1019} predicted to perturb Rab binding, confirmed that biological activity requires contacts between cognate RabGAPs and Rabs beyond those in the yeast Gyp1p RabGAP/mouse Rab33B structure.

S Park; W Jin; S Shoelson

2011-12-31

379

A facile route for 3D aerogels from nanostructured 1D and 2D materials.  

UK PubMed Central (United Kingdom)

Aerogels have numerous applications due to their high surface area and low densities. However, creating aerogels from a large variety of materials has remained an outstanding challenge. Here, we report a new methodology to enable aerogel production with a wide range of materials. The method is based on the assembly of anisotropic nano-objects (one-dimensional (1D) nanotubes, nanowires, or two-dimensional (2D) nanosheets) into a cross-linking network from their colloidal suspensions at the transition from the semi-dilute to the isotropic concentrated regime. The resultant aerogels have highly porous and ultrafine three-dimensional (3D) networks consisting of 1D (Ag, Si, MnO(2), single-walled carbon nanotubes (SWNTs)) and 2D materials (MoS(2), graphene, h-BN) with high surface areas, low densities, and high electrical conductivities. This method opens up a facile route for aerogel production with a wide variety of materials and tremendous opportunities for bio-scaffold, energy storage, thermoelectric, catalysis, and hydrogen storage applications.

Jung SM; Jung HY; Dresselhaus MS; Jung YJ; Kong J

2012-01-01

380

CD1a and CD1d genes polymorphisms in breast, colorectal and lung cancers.  

UK PubMed Central (United Kingdom)

CD1 molecules might contribute to anti-tumor immune response by presentation of tumor-derived lipid and glycolipid antigens to T cells and NKT cells. Polymorphisms in CD1 genes have been suggested to modify ligand binding of CD1 molecules and thereby change the antigen presenting ability of these molecules. The aim of this study was to investigate the exon 2 polymorphisms of CD1a and CD1d in several high incident cancers in Iran. For this purpose, 201 female breast cancer patients and 207 healthy women, 64 lung cancer patients and 95 healthy individuals and 109 patients with colorectal cancer and 109 healthy controls were recruited to this study. Using PCR-SSP method, no significant correlation was found in genotype and allele frequencies of CD1a between all three studied groups and their control counterparts. Moreover, a dominant frequency of CD1d 01 (A) allele was observed in the majority of studied individuals. No significant association between the CD1 polymorphisms and prognostic factors in breast, lung and colorectal cancers was detected. Our results highlight the conserved nature of CD1 genes and may point to the immuoregulatory functions of CD1 molecules in cancer that can be exerted through fine tuning of NK, T and NKT cells.

Golmoghaddam H; Pezeshki AM; Ghaderi A; Doroudchi M

2011-09-01

 
 
 
 
381

CD1a and CD1d genes polymorphisms in breast, colorectal and lung cancers.  

Science.gov (United States)

CD1 molecules might contribute to anti-tumor immune response by presentation of tumor-derived lipid and glycolipid antigens to T cells and NKT cells. Polymorphisms in CD1 genes have been suggested to modify ligand binding of CD1 molecules and thereby change the antigen presenting ability of these molecules. The aim of this study was to investigate the exon 2 polymorphisms of CD1a and CD1d in several high incident cancers in Iran. For this purpose, 201 female breast cancer patients and 207 healthy women, 64 lung cancer patients and 95 healthy individuals and 109 patients with colorectal cancer and 109 healthy controls were recruited to this study. Using PCR-SSP method, no significant correlation was found in genotype and allele frequencies of CD1a between all three studied groups and their control counterparts. Moreover, a dominant frequency of CD1d 01 (A) allele was observed in the majority of studied individuals. No significant association between the CD1 polymorphisms and prognostic factors in breast, lung and colorectal cancers was detected. Our results highlight the conserved nature of CD1 genes and may point to the immuoregulatory functions of CD1 molecules in cancer that can be exerted through fine tuning of NK, T and NKT cells. PMID:21258883

Golmoghaddam, Hossein; Pezeshki, Abdul Mohammad; Ghaderi, Abbas; Doroudchi, Mehrnoosh

2011-01-22

382

Testing a 1-D Analytical Salt Intrusion Model and the Predictive Equation in Malaysian Estuaries  

Science.gov (United States)

Little is known about the salt intrusion behaviour in Malaysian estuaries. Study on this topic sometimes requires large amounts of data especially if a 2-D or 3-D numerical models are used for analysis. In poor data environments, 1-D analytical models are more appropriate. For this reason, a fully analytical 1-D salt intrusion model, based on the theory of Savenije in 2005, was tested in three Malaysian estuaries (Bernam, Selangor and Muar) because it is simple and requires minimal data. In order to achieve that, site surveys were conducted in these estuaries during the dry season (June-August) at spring tide by moving boat technique. Data of cross-sections, water levels and salinity were collected, and then analysed with the salt intrusion model. This paper demonstrates a good fit between the simulated and observed salinity distribution for all three estuaries. Additionally, the calibrated Van der Burgh's coefficient K, Dispersion coefficient D0, and salt intrusion length L, for the estuaries also displayed a reasonable correlations with those calculated from the predictive equations. This indicates that not only is the salt intrusion model valid for the case studies in Malaysia but also the predictive model. Furthermore, the results from this study describe the current state of the estuaries with which the Malaysian water authority in Malaysia can make decisions on limiting water abstraction or dredging. Keywords: salt intrusion, Malaysian estuaries, discharge, predictive model, dispersion

Gisen, Jacqueline Isabella; Savenije, Hubert H. G.

2013-04-01

383

1-D Air-snowpack modeling of atmospheric nitrous acid at South Pole during ANTCI 2003  

Directory of Open Access Journals (Sweden)

Full Text Available A 1-D air-snowpack model of HONO has been developed and constrained by observed chemistry and meteorology data. The 1-D model includes molecular diffusion and mechanical dispersion, windpumping in snow, gas phase to quasi-liquid layer phase HONO transfer and quasi-liquid layer nitrate and interstitial air HONO photolysis. Photolysis of nitrate is important as a dominant HONO source inside the snowpack, however, the observed HONO emission from the snowpack was triggered mainly by the equilibrium between quasi liquid layer nitrite and firn air HONO deep down the snow surface (i.e. 30 cm below snow surface). The high concentration of HONO in the firn air is subsequently transported above the snowpack by diffusion and windpumping. The model uncertainties come mainly from lack of measurements and the interpretation of the QLL properties based on the bulk snow measurements. One critical factor is the ionic strength of QLL nitrite, which is estimated here by the bulk snow pH, nitrite concentration, and QLL to bulk snow volume ratio.

W. Liao; D. Tan

2008-01-01

384

1-D air-snowpack modeling of atmospheric nitrous acid at South Pole during ANTCI 2003  

Directory of Open Access Journals (Sweden)

Full Text Available A 1-D air-snowpack model of HONO has been developed and constrained by observed chemistry and meteorology data. The 1-D model includes molecular diffusion and mechanical dispersion, windpumping in snow, gas phase to quasi-liquid layer phase HONO transfer and quasi-liquid layer nitrate and interstitial air HONO photolysis. Photolysis of nitrate is important as a dominant HONO source inside the snowpack, however, the observed HONO emission from the snowpack was triggered mainly by the equilibrium between quasi liquid layer nitrite and firn air HONO deep down the snow surface (i.e. 30 cm below snow surface). The high concentration of HONO in the firn air is subsequently transported above the snowpack by diffusion and windpumping. The model uncertainties come mainly from lack of measurements and the interpretation of the QLL properties based on the bulk snow measurements. One critical factor is the ionic strength of QLL nitrite, which is estimated here by the bulk snow pH, nitrite concentration, and QLL to bulk snow volume ratio.

Wei Liao; D. Tan

2008-01-01

385

Differences in LBLOCA thermal hydraulic response between 1D and 3D calculations  

International Nuclear Information System (INIS)

Best Estimate (BE) calculation of large break Loss of Coolant Accident (LBLOCA) has been applied to the most of the domestic Nuclear Power Plants (NPP). One of the recent concerns in LBLOCA analysis of APR1400 design was a potential of the 'blowdown quenching', which drastically decreased the fuel cladding temperatures by the downflow of the water from the Upper Guide Structure (USG) of the reactor vessel to the core. Depending on its extent, the cladding temperature response during reflood phase can change greatly, and then the uncertainty of reflood phenomena such as downcomer boiling may be more important. Due to the concern, a more specific analysis such as three dimensional (3D) calculation, has been required for the LBLOCA thermal hydraulic response. The present study is to discuss the 3D calculation and its result in comparison with that from 1D calculation. Several differences and their reasons are also discussed. MARS KS code was used for the 1D and 3D calculation, and the hot channel whose flow area is not greater than area of one fuel assembly was used

2012-01-01

386

4He Fluid in Extremely Narrow 1D Channels 1.5 nm in Diameter  

Science.gov (United States)

To examine whether one-dimensional (1D) helium quantum fluid is realized in narrower channels than those studied previously, we have measured heat capacities of 4He adsorbed in nanoporous material FSM with straight 1D channels 1.5 nm in diameter. From the heat of desorption for adsorbed 4He, the coverage n f, up to which 4He film grows in the channels, is determined to be 15.4 ?mol/m2 using the Frenkel-Halsey-Hill model. At coverages sufficiently below n f, the temperature dependence of the 4He heat capacity has a shoulder, above which adsorbed 4He is delocalized from the substrate. On the other hand, the depression of the heat capacity indicating quantum effects has not been observed up to n f, which suggests that 4He film in the channels remains amorphous-like normal fluid. Just above n f, the quantum effect is observed in 4He adatoms on the grain surface of FSM powder, which indicates that 1.5 nm channels are slightly below the limit required to realize quantum effect in the inside 4He fluid.

Matsushita, Taku; Hieda, Mitsunori; Wada, Nobuo

2011-03-01

387

Temperature-Dependent Maximum Density of 1D Excitons in Carbon Nanotubes  

Science.gov (United States)

Previous studies have shown that an upper limit exists on the density of 1D excitons in single-walled carbon nanotubes (SWNTs) due to very efficient exciton-exciton annihilation (EEA). A recent theoretical study based on a dark-bright two-band exciton model predicts that there is a temperature at which the achievable exciton density will be maximized, surpassing the room-temperature upper limit. Therefore, we performed temperature-dependent (300 K to 11 K) photoluminescence (PL) on HiPco SWNTs embedded in an i-carrageenan matrix under high resonant excitation. To achieve high densities, we used pump fluences up to ˜ 10^14 photons/cm^2, utilizing intense fs pulses from a wavelength-tunable optical parametric amplifier. We found that for each temperature the PL intensity saturates as a function of pump fluence and the saturation intensity increases from 300 K to a moderate temperature around 100-150 K. Below that critical temperature, the PL intensity decreases with decreasing temperature. Within the framework of diffusion-limited EEA, we successfully estimated the upper limit of the density of 1D excitons in SWNTs as a function of temperature and chirality

Searles, Thomas; Walsh, Ian; Nosaka, Takayuki; Rice, William; Kono, Junichiro

2011-03-01

388

Comparison analysis of 1D/2D/3D neutronics modeling for a fusion reactor  

International Nuclear Information System (INIS)

Fusion reactors have the characteristics of a strong anisotropic neutron flux distribution, wide range of neutron energy and spatial non-uniformity of the power density distribution caused by the external fusion neutron source. The static state neutronics analyses of a fusion power reactor (named FDS-II) have been carried out to find out the effects of the 1D/2D/3D geometric descriptions for computational models. The neutron wall loading distribution, tritium-breeding ratio and power density distribution are calculated to evaluate the nuclear performance using the Monte Carlo transport code MCNP4C and nuclear data library FENDL-2.1. Comparison of the results suggests that the value of TBR calculated by the 1D approach overestimates the tritium-breeding ratio especially in the inner blanket. The power density distribution based on the 2D and 3D models were similar since they all consider the effects of the axial components. For obtaining global scalar quantities for general use, simplified models of the fusion reactor are usually sufficient. However, more calculations are needed to test the validity of each model in different regions of phase space.

2007-10-05

389

Conformational study of molecules with asymmetric isotopic substitution. Ring puckering of 1-silacyclobutane-1-d1  

International Nuclear Information System (INIS)

1-Silacyclobutane-1-d1 has been prepared and its infrared spectra have been analyzed. Several ring-puckering transitions have been observed in the far-infrared region and sum and difference bands have been observed in the Si-H stretching region. A ring-puckering potential function which simultaneously fits the data for the D0, d1, and d2 isotopic forms has been determined. Calculation of the wave functions for the d1 molecule shows that each of the lowest two very nearly degenergy states (nu = 0 and nu = 1) corresponds to only one distinct molecular conformation. Similarly, the nearly degenerate nu = 2 and nu = 3 states are primarily restricted to specific conformations. Doublets observed for the Si-H and Si-D stretching bands, corresponding to stretches from equitorial or axial positions, confirm these calculations. Model calculations on related systems demonstrate that both a sufficiently large barrier height and an asymmetry of the kinetic energy expansions are necessary for the conformational separation according to vibrational states. Although the reduced masses of the two conformers of 1-silacyclobutane-1-d1 differ by only 0.20%, this is enough to produce the observed conformational discrimination

1982-10-28

390

Hypocenter determination using simulated annealing, updated 1D seismic velocity model and focal mechanism analysis  

Science.gov (United States)

Hypocenter determination of micro-earthquakes of Mount "X-1" geothermal field has been conducted using simulated annealing and guided error search method using a 1D seismic velocity model. In order to speed up the hypocenter determination process a three-circle intersection method has been used to guide the simulated annealing and guided error search process. We used P and S arrival time's microseismic data. In the simulated annealing and guided error search processes, the minimum travel time from a source to a receiver has been calculated by employing ray tracing with shooting method. The resulting hypocenters from the above process occurred at depths of 3-4 km below mean sea level. These hypocenter distributions are correlated with previous study which was concluded that the most active microseismic area in which the site of many fractures and also vertical circulation place. Later on, resulting hypocenters location was used as input to determine 1-D seismic velocity using joint hypocenter determination method. The results of VELEST indicate show low Vp/Vs ratio value at depths of 3-4 km. Our interpretation is this anomaly may be related to a rock layer which is saturated by vapor (gas or steam). Another feature is high Vp/Vs ratio value at depths of 1-3 km that may related to a rock layer which is saturated by fluid or partial melting. We also analyze the focal mechanism of microseismic using ISOLA method to determine the source characteristic of this event.

Akbar, Akhmad Fanani; Nugraha, Andri Dian; Sule, Rachmat; Juanda, Aditya Abdurrahman

2013-09-01

391

SNARK09 - a software package for reconstruction of 2D images from 1D projections.  

UK PubMed Central (United Kingdom)

The problem of reconstruction of slices and volumes from 1D and 2D projections has arisen in a large number of scientific fields (including computerized tomography, electron microscopy, X-ray microscopy, radiology, radio astronomy and holography). Many different methods (algorithms) have been suggested for its solution. In this paper we present a software package, SNARK09, for reconstruction of 2D images from their 1D projections. In the area of image reconstruction, researchers often desire to compare two or more reconstruction techniques and assess their relative merits. SNARK09 provides a uniform framework to implement algorithms and evaluate their performance. It has been designed to treat both parallel and divergent projection geometries and can either create test data (with or without noise) for use by reconstruction algorithms or use data collected by another software or a physical device. A number of frequently-used classical reconstruction algorithms are incorporated. The package provides a means for easy incorporation of new algorithms for their testing, comparison and evaluation. It comes with tools for statistical analysis of the results and ten worked examples.

Klukowska J; Davidi R; Herman GT

2013-06-01

392

Ident 1D - a novel software tool for an easy identification of material constitutive parameters  

International Nuclear Information System (INIS)

Non-linear finite element computations make use of very sophisticated constitutive equations for description of materials behaviour. The first difficulty encountered by potential users is the gap existing between raw material characterisation on uniaxial specimens and the knowledge of the required equation's parameters. There are very few software for this particular task. IDENT 1D is a special software developed under Matlab language in our laboratory, which is able to provide a complete optimised parameters set for implemented models. The originality of IDENT 1D is that no initial estimation of the material parameters is requested of the user. Two main examples are described in this article: the Lemaitre and Chaboche creep law coupled with damage and a non unified cyclic law proposed by Contesti and Cailletaud with a separation of plastic and viscous strain terms which is called DDI model. For both laws, the identification method is completely described. Each method is then applied to a set of experimental data. In both cases, the results of the parameters identification show a very good agreement with experimental data. (authors)

1998-01-01