Absence of paired crossing in the positive parity bands of 124Cs

Science.gov (United States)

Singh, A. K.; Basu, A.; Nag, Somnath; Hübel, H.; Domscheit, J.; Ragnarsson, I.; Al-Khatib, A.; Hagemann, G. B.; Herskind, B.; Elema, D. R.; Wilson, J. N.; Clark, R. M.; Cromaz, M.; Fallon, P.; Görgen, A.; Lee, I.-Y.; Ward, D.; Ma, W. C.

2018-02-01

High-spin states in 124Cs were populated in the 64Ni(64Ni,p 3 n ) reaction and the Gammasphere detector array was used to measure γ -ray coincidences. Both positive- and negative-parity bands, including bands with chiral configurations, have been extended to higher spin, where a shape change has been observed. The configurations of the bands before and after the alignment are discussed within the framework of the cranked Nilsson-Strutinsky model. The calculations suggest that the nucleus undergoes a shape transition from triaxial to prolate around spin I ≃22 of the positive-parity states. The alignment gain of 8 ℏ , observed in the positive-parity bands, is due to partial alignment of several valence nucleons. This indicates the absence of band crossing due to paired nucleons in the bands.

S-band low noise amplifier and 40 kW high power amplifier subsystems of Japanese Deep Space Earth Station

Science.gov (United States)

Honma, K.; Handa, K.; Akinaga, W.; Doi, M.; Matsuzaki, O.

This paper describes the design and the performance of the S-band low noise amplifier and the S-band high power amplifier that have been developed for the Usuda Deep Space Station of the Institute of Space and Astronautical Science (ISAS), Japan. The S-band low noise amplifier consists of a helium gas-cooled parametric amplifier followed by three-stage FET amplifiers and has a noise temperature of 8 K. The high power amplifier is composed of two 28 kW klystrons, capable of transmitting 40 kW continuously when two klystrons are combined. Both subsystems are operating quite satisfactorily in the tracking of Sakigake and Suisei, the Japanese interplanetary probes for Halley's comet exploration, launched by ISAS in 1985.

Strong temperature effect on the sizes of the Cooper pairs in a two-band superconductor

Science.gov (United States)

Örd, Teet; Rägo, Küllike; Vargunin, Artjom; Litak, Grzegorz

2018-01-01

We study the temperature dependencies of the mean sizes of the Cooper pairs in a two-band BCS-type s-wave superconductivity model with coupling cut-off in the momentum space. It is found that, in contrast to single-band systems, the size of Cooper pairs in the weaker superconductivity band can significantly decrease with a temperature increase due to an interband proximity effect. The relevant spatial behaviour of the wave functions of the Cooper pairs is analyzed. The results also indicate a possibility that the size of Cooper pairs in two-band systems may increase with an increase in temperature.

On pair-absorption in intrinsic vapours

International Nuclear Information System (INIS)

Hotop, R.; Niemax, K.; Schlueter, D.

1982-01-01

The bound-state pair-absorption bands Cs(6 2 S 1 sub(/) 2 ) + Cs(6 2 S 1 sub(/) 2 ) + hν → Cs(5 2 D 5 sub(/) 2 sub(,) 3 sub(/) 2 ) + Cs(6 2 P 1 sub(/) 2 ) and the K-K continuum-state pair-absorptions in the wavelength region 2.350 <= lambda <= 2.850 Angstroem have been investigated experimentally. In the case of the bound-state pair-absorption bands a theoretical approach for the absorption cross section at the band centre is given which is in good agreement with the experimental observation. Differences between our and the theoretical formulas given by the Stanford group are discussed. (orig.)

The marginal band system in nymphalid butterfly wings.

Science.gov (United States)

Taira, Wataru; Kinjo, Seira; Otaki, Joji M

2015-01-01

Butterfly wing color patterns are highly complex and diverse, but they are believed to be derived from the nymphalid groundplan, which is composed of several color pattern systems. Among these pattern systems, the marginal band system, including marginal and submarginal bands, has rarely been studied. Here, we examined the color pattern diversity of the marginal band system among nymphalid butterflies. Marginal and submarginal bands are usually expressed as a pair of linear bands aligned with the wing margin. However, a submarginal band can be expressed as a broken band, an elongated oval, or a single dot. The marginal focus, usually a white dot at the middle of a wing compartment along the wing edge, corresponds to the pupal edge spot, one of the pupal cuticle spots that signify the locations of color pattern organizing centers. A marginal band can be expressed as a semicircle, an elongated oval, or a pair of eyespot-like structures, which suggest the organizing activity of the marginal focus. Physical damage at the pupal edge spot leads to distal dislocation of the submarginal band in Junonia almana and in Vanessa indica, suggesting that the marginal focus functions as an organizing center for the marginal band system. Taken together, we conclude that the marginal band system is developmentally equivalent to other symmetry systems. Additionally, the marginal band is likely a core element and the submarginal band a paracore element of the marginal band system, and both bands are primarily specified by the marginal focus organizing center.

High-spin spectroscopy of {sup 168}Yb and the reduction of pairing correlations

Energy Technology Data Exchange (ETDEWEB)

Oliveira, J R.B. [Sao Paulo Univ., SP (Brazil); Stephens, F S; Deleplanque, M A; Diamond, R M [Lawrence Berkeley Lab., CA (United States); Draper, J E; Rubel, E; Duyar, C [California Univ., Davis, CA (United States); Beacker, J A; Henry, E A; Roy, N [Lawrence Livermore National Lab., CA (United States); Beausang, C W [Liverpool Univ. (United Kingdom); Frauendorf, S [Institut fur Kern und Hadronen Physik, F2-Rossendorf, Dresden (Germany)

1992-08-01

The high spin states of {sup 168}Yb were investigated by means of in-beam gamma spectroscopy with the High Energy Resolution Array at the 88 in. cyclotron of the Lawrence Berkeley Laboratory. The {sup 168}Yb nucleus was produced in the reaction {sup 48}Ca({sup 124}Sn,4n) at 210 MeV. Five bands previously reported were confirmed; additionally, four other bands, two extending to spins as high as 36 {Dirac_h} were observed. Cranked shell models suggest that one of the new bands can be interpreted as the continuation of the ground state band (above the AB crossing frequency) crossing into the four-quasiparticle band ABCD at about 0.38 MeV. Both relative alignment and Routhians are in good agreement with the experimental values. However, these calculations were done at constant pairing strength, which is not expected to be good at high rotational frequencies where one or more crossings have occurred in each band. Particle-hole calculations (with no pairing) were done for {sup 168}Yb as well as for other N {approx_equal} 98 nuclei for which good experimental data are available. In most cases, it is possible to associate a particle-hole configuration for each band observed at very high rotational frequencies, and the overall description is good. At frequencies below the first crossing, a full pairing calculation is necessary to describe the bands properly. At intermediate frequencies, the pairing strength is believed to be intermediate. 3 figs.

Collision-induced absorption by D2 pairs in the first overtone band at 77, 201 and 298 K

International Nuclear Information System (INIS)

Abu-Kharma, M.; Gillard, P.G.; Reddy, S.P.

2006-01-01

Collision induced absorption (CIA) spectra of pure D 2 in the first overtone region from 5250 to 7250 cm -1 , recorded at 77, 201 and 298 K, have been analyzed. The observed spectra at 77, 201 and 298 K were modelled by a total of 92, 214 and 267 components respectively of double vibrational transitions at room temperature of the type X 2 (J) +X 0 (J) and X 1 (J) + X 1 (J), where X is O, Q or S transitions. Profile analyses of the spectra were carried out using the Birnbaum-Cohen line-shape function for the individual components of the band, and characteristic line shape parameters were determined from the analysis. The observed and calculated profiles agree well over the whole overtone band, and the agreement is better than 97% in the three cases studied. Binary and ternary absorption coefficients were determined from the integrated absorption of the band. (authors)

K-band spectroscopic metallicities and temperatures of M-dwarf stars

Directory of Open Access Journals (Sweden)

Rojas-Ayala Bárbara

2013-04-01

Full Text Available I present the metallicity and effective temperature techniques developed for M dwarf stars by Rojas-Ayala et al. (2010, 2012. These techniques are based on absorption features present in the modest resolution K-band spectra (R∼2700 of M dwarfs and have been calibrated using FGK+M dwarf pairs and synthetic atmosphere models. The H2O-K2 index seems to overestimate the effective temperatures of M dwarfs when compared to interferometric measurements. The metallicity distribution of the M dwarf host candidates by the Kepler Mission hints that jovian-size planets form preferentially around solar and super-solar metallicity environments, while small rocky planet host exhibit a wide range of metallicities, just like in their solar-type counterparts.

RPC Calculations for K-forbidden Transitions in {sup 183}W, Evidence for Large Inertial Parameter Connected with High-lying Rotational Bands

Energy Technology Data Exchange (ETDEWEB)

Malmskog, S G [AB Atomenergi, Nykoeping (Sweden); Wahlborn, S [Div. of Theore tical Physics, Royal Inst. of Technology Stockholm (Sweden)

1967-09-15

Recent measurements have shown that the transitions deexciting the 453 keV 7/2{sup -} level in {sup 183}W to the K = 1/2{sup -} and 3/2{sup -} bands are strongly retarded. The data for B(M1) and B(E2) are analyzed in terms of the RPC model (rotation + particle motion + coupling). With the {delta}K = 1 (Coriolis) coupling, the K-forbidden M1-transitions proceed via admixtures of high-lying 5/2{sup -} bands. A reasonable and unambiguous fit to the data is obtained by varying the strength of the coupling. Allowing for various uncertainties and corrections, one finds that the inertial parameter (the inverse of the coupling constant, i. e. 2J(2{pi}){sup 2}/({Dirac_h}){sup 2} may have values between roughly 1 and 3 times the rigid rotator value of 2J(2{pi}){sup 2}/({Dirac_h}){sup 2}, thus being unexpectedly large. Calculations with the {delta}K=2 coupling were also performed and turn out not to give better agreement with experiment.

Alignments of multi-quasiparticle bands and seniority-dependent reduced pairing

International Nuclear Information System (INIS)

Dracoulis, G.D.

1994-09-01

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

Evolution of the major merger galaxy pair fraction at z < 1

Energy Technology Data Exchange (ETDEWEB)

Keenan, R. C.; Hsieh, B. C.; Lin, L.; Chou, R. C. Y.; Huang, S.; Lin, J. H.; Chang, K. H. [Academia Sinica Institute for Astronomy and Astrophysics, Taipei, Taiwan (China); Foucaud, S. [Shanghai Jiao Tong University, Shanghai (China); De Propris, R. [Finnish Centre for Astronomy with ESO (FINCA), University of Turku, Turku (Finland)

2014-11-10

We present a study of the largest available sample of near-infrared selected (i.e., stellar mass selected) dynamically close pairs of galaxies at low redshifts (z < 0.3). We combine this sample with new estimates of the major merger pair fraction for stellar mass selected galaxies at z < 0.8, from the Red Sequence Cluster Survey (RCS1). We construct our low-redshift K-band selected sample using photometry from the UKIRT Infrared Deep Sky Survey and the Two Micron All Sky Survey (2MASS) in the K band (∼2.2 μm). Combined with all available spectroscopy, our K-band selected sample contains ∼250, 000 galaxies and is >90% spectroscopically complete. The depth and large volume of this sample allow us to investigate the low-redshift pair fraction and merger rate of galaxies over a wide range in K-band luminosity. We find the major merger pair fraction to be flat at ∼2% as a function of K-band luminosity for galaxies in the range 10{sup 8}-10{sup 12} L {sub ☉}, in contrast to recent results from studies in the local group that find a substantially higher low-mass pair fraction. This low-redshift major merger pair fraction is ∼40%-50% higher than previous estimates drawn from K-band samples, which were based on 2MASS photometry alone. Combining with the RCS1 sample, we find a much flatter evolution (m = 0.7 ± 0.1) in the relation f {sub pair}∝(1 + z) {sup m} than indicated in many previous studies. These results indicate that a typical L ∼ L* galaxy has undergone ∼0.2-0.8 major mergers since z = 1 (depending on the assumptions of merger timescale and percentage of pairs that actually merge).

Evolution of the major merger galaxy pair fraction at z < 1

International Nuclear Information System (INIS)

Keenan, R. C.; Hsieh, B. C.; Lin, L.; Chou, R. C. Y.; Huang, S.; Lin, J. H.; Chang, K. H.; Foucaud, S.; De Propris, R.

2014-01-01

We present a study of the largest available sample of near-infrared selected (i.e., stellar mass selected) dynamically close pairs of galaxies at low redshifts (z < 0.3). We combine this sample with new estimates of the major merger pair fraction for stellar mass selected galaxies at z < 0.8, from the Red Sequence Cluster Survey (RCS1). We construct our low-redshift K-band selected sample using photometry from the UKIRT Infrared Deep Sky Survey and the Two Micron All Sky Survey (2MASS) in the K band (∼2.2 μm). Combined with all available spectroscopy, our K-band selected sample contains ∼250, 000 galaxies and is >90% spectroscopically complete. The depth and large volume of this sample allow us to investigate the low-redshift pair fraction and merger rate of galaxies over a wide range in K-band luminosity. We find the major merger pair fraction to be flat at ∼2% as a function of K-band luminosity for galaxies in the range 10 8 -10 12 L ☉ , in contrast to recent results from studies in the local group that find a substantially higher low-mass pair fraction. This low-redshift major merger pair fraction is ∼40%-50% higher than previous estimates drawn from K-band samples, which were based on 2MASS photometry alone. Combining with the RCS1 sample, we find a much flatter evolution (m = 0.7 ± 0.1) in the relation f pair ∝(1 + z) m than indicated in many previous studies. These results indicate that a typical L ∼ L* galaxy has undergone ∼0.2-0.8 major mergers since z = 1 (depending on the assumptions of merger timescale and percentage of pairs that actually merge).

Collision-induced absorption by D{sub 2} pairs in the first overtone band at 77, 201 and 298 K

Energy Technology Data Exchange (ETDEWEB)

Abu-Kharma, M.; Gillard, P.G.; Reddy, S.P. [Memorial University of Newfoundland, Dept. of Physics and Physical Oceanography, Newfoundland (Canada)

2006-01-15

Collision induced absorption (CIA) spectra of pure D{sub 2} in the first overtone region from 5250 to 7250 cm{sup -1}, recorded at 77, 201 and 298 K, have been analyzed. The observed spectra at 77, 201 and 298 K were modelled by a total of 92, 214 and 267 components respectively of double vibrational transitions at room temperature of the type X{sub 2}(J) +X{sub 0}(J) and X{sub 1}(J) + X{sub 1}(J), where X is O, Q or S transitions. Profile analyses of the spectra were carried out using the Birnbaum-Cohen line-shape function for the individual components of the band, and characteristic line shape parameters were determined from the analysis. The observed and calculated profiles agree well over the whole overtone band, and the agreement is better than 97% in the three cases studied. Binary and ternary absorption coefficients were determined from the integrated absorption of the band. (authors)

Conduction band-edge d-states in high-k dielectrics due to Jahn-Teller term splittings

International Nuclear Information System (INIS)

Lucovsky, G.; Fulton, C.C.; Zhang, Y.; Luning, J.; Edge, L.; Whitten, J.L.; Nemanich, R.J.; Schlom, D.G.; Afanase'v, V.V.

2005-01-01

X-ray absorption spectroscopy (XAS) is used to study conduction band edge electronic structure of high-k transition metal (TM) and trivalent lanthanide series rare earth (RE) oxide dielectrics. Empty TM/RE d-states are studied by intra-atomic transitions originating in core level spin-orbit split p-states, and conduction band states are studied in inter-atomic transitions which originate in the oxygen atom 1s core level state. In non-crystalline Zr and Hf silicate alloys, the local bonding symmetry, or crystal field splits these d-states into doubly and triply degenerate features. In nano-crystalline oxides, there are additional d-state splittings due to contributions of more distant neighbors that completely remove d-state degeneracies via the Jahn-Teller effect mechanism. This gives rise to highly localized band edge states that are electronically active in photoconductivity, internal photoemission, and act as bulk traps in metal oxide semiconductor (MOS) devices

Ultrabright, narrow-band photon-pair source for atomic quantum memories

Science.gov (United States)

Tsai, Pin-Ju; Chen, Ying-Cheng

2018-06-01

We demonstrate an ultrabright, narrow-band and frequency-tunable photon-pair source based on cavity-enhanced spontaneous parametric down conversion (SPDC) which is compatible with atomic transition of rubidium D 2-line (780 nm) or cesium D 2-line (852 nm). With the pump beam alternating between a high and a low power phase, the output is switching between the optical parametric oscillator (OPO) and photon-pair generation mode. We utilize the OPO output light to lock the cavity length to maintain the double resonances of signal and idler, as well as to lock the signal frequency to cesium atomic transition. With a type-II phase matching and a double-passed pump scheme such that the cluster frequency spacing is larger than the SPDC bandwidth, the photon-pair output is in a nearly single-mode operation as confirmed by a scanning Fabry–Perot interferometer with its output detected by a photomultiplier. The achieved generation and detection rates are 7.24× {10}5 and 6142 s‑1 mW‑1, respectively. The correlation time of the photon pair is 21.6(2.2) ns, corresponding to a bandwidth of 2π × 6.6(6) MHz. The spectral brightness is 1.06× {10}5 s‑1 mW‑1 MHz‑1. This is a relatively high value under a single-mode operation with the cavity-SPDC scheme. The generated single photons can be readily used in experiments related to atomic quantum memories.

Analysis of RF section of 250 kW CW C-Band high power klystron

International Nuclear Information System (INIS)

Badola, Richa; Kaushik, Meenu; Baloda, Suman; Kirti; Vrati; Lamba, O.S.; Joshi, L.M.

2012-01-01

Klystron is a microwave tube which is used as a power amplifier in various applications like radar, particle accelerators and thermonuclear reactors. The paper deals with the analysis of RF section of 250 kW CW C band high power klystron for 50 to 60 kV beam voltage The simulation is done using Poisson's superfish and AJ disk software's Design of cavity is done using superfish. The result of superfish is used to decide the dimensions of the geometry of the cavity and AJ disk is used to determined the centre to centre distances between the cavities in order to obtain the desired powers. (author)

Mass renormalization and unconventional pairing in multi-band Fe-based superconductors- a phenomenological approach

Energy Technology Data Exchange (ETDEWEB)

Drechsler, S.L.; Efremov, D.; Grinenko, V. [IFW-Dresden (Germany); Johnston, S. [Inst. of Quantum Matter, University of British Coulumbia, Vancouver (Canada); Rosner, H. [MPI-cPfS, Dresden, (Germany); Kikoin, K. [Tel Aviv University (Israel)

2015-07-01

Combining DFT calculations of the density of states and plasma frequencies with experimental thermodynamic, optical, ARPES, and dHvA data taken from the literature, we estimate both the high-energy (Coulomb, Hund's rule coupling) and the low-energy (el-boson coupling) electronic mass renormalization [H(L)EMR] for typical Fe-pnictides with T{sub c}<40 K, focusing on (K,Rb,Cs)Fe{sub 2}As{sub 2}, (Ca,Na)122, (Ba,K)122, LiFeAs, and LaFeO{sub 1-x}F{sub x}As with and without As-vacancies. Using Eliashberg theory we show that these systems can NOT be described by a very strong el-boson coupling constant λ ≥ ∝ 2, being in conflict with the HEMR as seen by DMFT, ARPES and optics. Instead, an intermediate s{sub ±} coupling regime is realized, mainly based on interband spin fluctuations from one predominant pair of bands. For (Ca,Na)122, there is also a non-negligible intraband el-phonon/orbital fluctuation intraband contribution. The coexistence of magnetic As-vacancies and high-T{sub c}=28 K for LaFeO{sub 1-x}F{sub x}As{sub 1-δ} excludes an orbital fluctuation dominated s{sub ++} scenario at least for that system. In contrast, the line nodal BaFe{sub 2}(As,P){sub 2} near the quantum critical point is found as a superstrongly coupled system. The role of a pseudo-gap is briefly discussed for some of these systems.

Possible antipolar pairing mechanism in high-temperature superconductors

International Nuclear Information System (INIS)

Cardwell, D.A.; Shorrocks, N.M.

1989-01-01

An antipolar pairing mechanism for free charge carriers in high-T c superconducting compounds is proposed qualitatively. This involves the establishment of a two-dimensional (2D) array of effective charge-coupling centers within the superconducting lattice via a specific phonon distortion of cation species along a nonmajor crystallographic direction. A fundamental requirement of this model is that the density of such coupling centers decreases with decreasing temperature. In the case of Y-Ba-Cu-O, it is asserted that charge carriers in a 2D oxygen band adjacent to the phonon-containing plane become localized by the resulting (local) field distortion. Cooper pairs may then form when the charge-coupling-center density falls below the charge-carrier density. Such a mechanism could be mediated by a longitudinal phonon which softens at low temperatures to produce an antipolar state, such as that incipient to an antiferroelectric distortion of the lattice (i.e., in the zero-frequency limiting case). This model, which may be investigated experimentally by low-temperature Raman spectroscopy, isotopic substitution, and x-ray diffractometry at 4.2 K, can be applied to all p-type high-T c systems. In addition, it may account for the observed lattice anisotropy and short coherence length characteristic of these materials

The Role of E27-K31 and E56-K10 Salt-Bridge Pairs in the Unfolding Mechanism of the B1 Domain of Protein G

Directory of Open Access Journals (Sweden)

Tony Ibnu Sumaryada

2018-02-01

Full Text Available Molecular dynamics simulations of the B1 fragment of protein G (56 residues have been performed at 325, 350, 375, 400, 450 and 500 K for 10 ns. An analysis of its structural and energetic parameters has indicated that the unfolding process of the GB1 protein begins at 900 ps of a 500-K simulation. The unfolding process is initiated when hydrogen bonds in the hydrophobic core region are broken; it continues with the α-helix transformation into coils and turns and ends with the destruction of the β-hairpins. These unfolding events are consistent with the hybrid model of the protein folding/unfolding mechanism, which is a compromise between the hydrophobic core collapse model and the zipper model. Salt-bridge pairs were found to play an important role in the unfolding process by maintaining the integrity of the tertiary structure of the protein. The breaking (or disappearance of the salt-bridge pairs E27–K31 (in the α-helix and E56–K10 (connecting β4 and β1 has resulted in the destruction of secondary structures and indicates the beginning of the unfolding process. Our results also suggest that the unfolding process in this simulation was not a complete denaturation of the protein because some β-hairpins remained

Possible conservation of the K-quantum number in excited rotating nuclei

Energy Technology Data Exchange (ETDEWEB)

Bracco, A.; Bosetti, P.; Leoni, S. [Universita di Milano (Italy)]|[INFN, Milano (Italy)] [and others

1996-12-31

The {gamma}-cascades feeding into low-K and high-K bands in the nucleus {sup 163}Er are investigated by analyzing variances and covariances of the spectrum fluctuations. The study of the covariance between pairs of gated spectra reveals that the cascades feeding into the low-K bands are completely different from those feeding the high-K bands. In addition, the number of decay paths obtained analyzing the ridge and the valley in spectra gated by high-K transitions is different than that deduced from the total spectrum. This result is well reproduced with microscopic calculations of strongly interacting bands. It is concluded that the K-selection rules are effective for the excited rotational bands within the angular momentum region probed by the experiment, 30{Dirac_h} {le} I {le} 40{Dirac_h}.

Rotational bands on few-particle excitations of very high spin

International Nuclear Information System (INIS)

Andersson, C.G.; Krumlinde, J.; Leander, G.; Szymanski, Z.

1980-01-01

An RPA formalism is developed to investigate the existence and properties of slow collective rotation around a non-symmetry axis, when there already exists a large angular momentum K along the symmetry axis built up by aligned single-particle spins. It is found necessary to distinguish between the collectivity and the repeatability of the rotational excitations. First the formalism is applied to bands on hihg-K isomers in the well-deformed nucleus 176 Hf, where the rotational-model picture is reproduced for intermediate K-values in agreement with experiment. At high K there is a suppression of the collectivity corresponding to the diminishing vector-coupling coefficient of the rotational model, but the repeatability actually improves. The moment of inertia is predicted to remain substantially smaller than the rigid-body value so the bands slope up steeply from the yrast line at spins where pairing effects are gone. A second application is to the initially spherical nucleus 212 Rn, which is believed to acquire an oblate deformation that increases steadily with K due to the oblate shape of the aligned orbitals. In this case the repeatable excitations come higher above the yrast line than in 176 Hf, even at comparable deformations. Some collective states may occur very close to yrast, but these are more like dressed singleparticle excitations. The main differences between the two nuclei studied is interpreted as a general consequence of their different shell structure. (author)

Multi-quasiparticle isomers near stability and reduced pairing

Energy Technology Data Exchange (ETDEWEB)

Dracoulis, G.D. [Australian National Univ., Canberra (Australia)

1996-12-31

The proximity of high-{Omega} orbitals near both proton and neutron Fermi surfaces in nuclei near Z = 74 and N = 104 results in high-K states competing with collective rotation of low-seniority configurations to generate the yrast line. In favorable situations it is possible to observe both the intrinsic states and associated rotational bands. The band properties allow characterization of the configurations and evaluation of orbital and seniority-dependent effects, including pairing reduction and consequent loss of nuclear superfluidity.

Frequency band adjustment match filtering based on variable frequency GPR antennas pairing scheme for shallow subsurface investigations

Science.gov (United States)

Shaikh, Shahid Ali; Tian, Gang; Shi, Zhanjie; Zhao, Wenke; Junejo, S. A.

2018-02-01

Ground penetrating Radar (GPR) is an efficient tool for subsurface geophysical investigations, particularly at shallow depths. The non-destructiveness, cost efficiency, and data reliability are the important factors that make it an ideal tool for the shallow subsurface investigations. Present study encompasses; variations in central frequency of transmitting and receiving GPR antennas (Tx-Rx) have been analyzed and frequency band adjustment match filters are fabricated and tested accordingly. Normally, the frequency of both the antennas remains similar to each other whereas in this study we have experimentally changed the frequencies of Tx-Rx and deduce the response. Instead of normally adopted three pairs, a total of nine Tx-Rx pairs were made from 50 MHz, 100 MHz, and 200 MHz antennas. The experimental data was acquired at the designated near surface geophysics test site of the Zhejiang University, Hangzhou, China. After the impulse response analysis of acquired data through conventional as well as varied Tx-Rx pairs, different swap effects were observed. The frequency band and exploration depth are influenced by transmitting frequencies rather than the receiving frequencies. The impact of receiving frequencies was noticed on the resolution; the more noises were observed using the combination of high frequency transmitting with respect to low frequency receiving. On the basis of above said variable results we have fabricated two frequency band adjustment match filters, the constant frequency transmitting (CFT) and the variable frequency transmitting (VFT) frequency band adjustment match filters. By the principle, the lower and higher frequency components were matched and then incorporated with intermediate one. Therefore, this study reveals that a Tx-Rx combination of low frequency transmitting with high frequency receiving is a better choice. Moreover, both the filters provide better radargram than raw one, the result of VFT frequency band adjustment filter is

NARROW-K-BAND OBSERVATIONS OF THE GJ 1214 SYSTEM

Energy Technology Data Exchange (ETDEWEB)

Colón, Knicole D.; Gaidos, Eric, E-mail: colonk@hawaii.edu [Department of Geology and Geophysics, University of Hawaii at Manoa, Honolulu, HI 96822 (United States)

2013-10-10

GJ 1214 is a nearby M dwarf star that hosts a transiting super-Earth-size planet, making this system an excellent target for atmospheric studies. Most studies find that the transmission spectrum of GJ 1214b is flat, which favors either a high mean molecular weight or cloudy/hazy hydrogen (H) rich atmosphere model. Photometry at short wavelengths (<0.7 μm) and in the K band can discriminate the most between these different atmosphere models for GJ 1214b, but current observations do not have sufficiently high precision. We present photometry of seven transits of GJ 1214b through a narrow K-band (2.141 μm) filter with the Wide Field Camera on the 3.8 m United Kingdom Infrared Telescope. Our photometric precision is typically 1.7 × 10{sup –3} (for a single transit), comparable with other ground-based observations of GJ 1214b. We measure a planet-star radius ratio of 0.1158 ± 0.0013, which, along with other studies, also supports a flat transmission spectrum for GJ 1214b. Since this does not exclude a scenario where GJ 1214b has an H-rich envelope with heavy elements that are sequestered below a cloud/haze layer, we compare K-band observations with models of H{sub 2} collision-induced absorption in an atmosphere for a range of temperatures. While we find no evidence for deviation from a flat spectrum (slope s = 0.0016 ± 0.0038), an H{sub 2}-dominated upper atmosphere (<60 mbar) cannot be excluded. More precise observations at <0.7 μm and in the K band, as well as a uniform analysis of all published data, would be useful for establishing more robust limits on atmosphere models for GJ 1214b.

Ground-state and pairing-vibrational bands with equal quadrupole collectivity in 124Xe

Science.gov (United States)

Radich, A. J.; Garrett, P. E.; Allmond, J. M.; Andreoiu, C.; Ball, G. C.; Bianco, L.; Bildstein, V.; Chagnon-Lessard, S.; Cross, D. S.; Demand, G. A.; Diaz Varela, A.; Dunlop, R.; Finlay, P.; Garnsworthy, A. B.; Hackman, G.; Hadinia, B.; Jigmeddorj, B.; Laffoley, A. T.; Leach, K. G.; Michetti-Wilson, J.; Orce, J. N.; Rajabali, M. M.; Rand, E. T.; Starosta, K.; Sumithrarachchi, C. S.; Svensson, C. E.; Triambak, S.; Wang, Z. M.; Wood, J. L.; Wong, J.; Williams, S. J.; Yates, S. W.

2015-04-01

The nuclear structure of 124Xe has been investigated via measurements of the β+/EC decay of 124Cs with the 8 π γ -ray spectrometer at the TRIUMF-ISAC facility. The data collected have enabled branching ratio measurements of weak, low-energy transitions from highly excited states, and the 2+→0+ in-band transitions have been observed. Combining these results with those from a previous Coulomb excitation study, B (E 2 ;23+→02+) =78 (13 ) W.u. and B (E 2 ;24+→03+) =53 (12 ) W.u. were determined. The 03+ state, in particular, is interpreted as the main fragment of the proton-pairing vibrational band identified in a previous 122Te (3He,n )124Xe measurement, and has quadrupole collectivity equal to, within uncertainty, that of the ground-state band.

Band-to-band and inner shell excitation VIS-UV photoluminescence of quaternary InAlGaN alloys

International Nuclear Information System (INIS)

Fukui, K.; Naoe, S.; Okada, K.; Hamada, S.; Hirayama, H.

2006-01-01

Visible and ultraviolet photoluminescence and photoluminescence excitation spectra of quaternary InAlGaN alloys were measured. The excitation photon energy covers from band edge to 180 eV, near both nitrogen K (∝400 eV) and aluminium K (∝1.5 keV) inner shell energy region. From photoluminescence excitation spectra photoluminescence intensity per incident photon number varies in proportion to incident photon energy. This result implies that many conduction band electron - valence band hole pairs which are responsible for photoluminescence are produced by high energy excitation. Time resolved decay curves were also measured in the same energy region. No effect of high energy excitation on time resolved decay measurements suggests a role of indium on the photoluminescence mechanism in InAlGaN system. (copyright 2006 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

Retrospective biodosimetry with small tooth enamel samples using K-Band and X-Band

International Nuclear Information System (INIS)

Gomez, Jorge A.; Kinoshita, Angela; Leonor, Sergio J.; Belmonte, Gustavo C.; Baffa, Oswaldo

2011-01-01

In an attempt to make the in vitro electron spin resonance (ESR) retrospective dosimetry of the tooth enamel a lesser invasive method, experiments using X-Band and K-Band were performed, aiming to determine conditions that could be used in cases of accidental exposures. First, a small prism from the enamel was removed and ground with an agate mortar and pestle until particles reach a diameter of approximately less than 0.5 mm. This enamel extraction process resulted in lower signal artifact compared with the direct enamel extraction performed with a diamond burr abrasion. The manual grinding of the enamel does not lead to any induced ESR signal artifact, whereas the use of a diamond burr at low speed produces a signal artifact equivalent to the dosimetric signal induced by a dose of 500 mGy of gamma irradiation. A mass of 25 mg of enamel was removed from a sound molar tooth previously irradiated in vitro with a dose of 100 mGy. This amount of enamel was enough to detect the dosimetric signal in a standard X-Band spectrometer. However using a K-Band spectrometer, samples mass between 5 and 10 mg were sufficient to obtain the same sensitivity. An overall evaluation of the uncertainties involved in the process in this and other dosimetric assessments performed at our laboratory indicates that it is possible at K-Band to estimate a 100 mGy dose with 25% accuracy. In addition, the use of K-Band also presented higher sensitivity and allowed the use of smaller sample mass in comparison with X-Band. Finally, the restoration process performed on a tooth after extraction of the 25 mg of enamel is described. This was conducted by dental treatment using photopolymerizable resin which enabled complete recovery of the tooth from the functional and aesthetic viewpoint showing that this procedure can be minimally invasive.

Retrospective biodosimetry with small tooth enamel samples using K-Band and X-Band

Energy Technology Data Exchange (ETDEWEB)

Gomez, Jorge A. [Departamento de Fisica, FFCLRP, Universidade de Sao Paulo, 14040-901 Ribeirao Preto, Sao Paulo (Brazil); Kinoshita, Angela [Departamento de Fisica, FFCLRP, Universidade de Sao Paulo, 14040-901 Ribeirao Preto, Sao Paulo (Brazil); Universidade Sagrado Coracao - USC, 17011-160 Bauru, Sao Paulo (Brazil); Leonor, Sergio J. [Departamento de Fisica, FFCLRP, Universidade de Sao Paulo, 14040-901 Ribeirao Preto, Sao Paulo (Brazil); Belmonte, Gustavo C. [Universidade Sagrado Coracao - USC, 17011-160 Bauru, Sao Paulo (Brazil); Baffa, Oswaldo, E-mail: baffa@usp.br [Departamento de Fisica, FFCLRP, Universidade de Sao Paulo, 14040-901 Ribeirao Preto, Sao Paulo (Brazil)

2011-09-15

In an attempt to make the in vitro electron spin resonance (ESR) retrospective dosimetry of the tooth enamel a lesser invasive method, experiments using X-Band and K-Band were performed, aiming to determine conditions that could be used in cases of accidental exposures. First, a small prism from the enamel was removed and ground with an agate mortar and pestle until particles reach a diameter of approximately less than 0.5 mm. This enamel extraction process resulted in lower signal artifact compared with the direct enamel extraction performed with a diamond burr abrasion. The manual grinding of the enamel does not lead to any induced ESR signal artifact, whereas the use of a diamond burr at low speed produces a signal artifact equivalent to the dosimetric signal induced by a dose of 500 mGy of gamma irradiation. A mass of 25 mg of enamel was removed from a sound molar tooth previously irradiated in vitro with a dose of 100 mGy. This amount of enamel was enough to detect the dosimetric signal in a standard X-Band spectrometer. However using a K-Band spectrometer, samples mass between 5 and 10 mg were sufficient to obtain the same sensitivity. An overall evaluation of the uncertainties involved in the process in this and other dosimetric assessments performed at our laboratory indicates that it is possible at K-Band to estimate a 100 mGy dose with 25% accuracy. In addition, the use of K-Band also presented higher sensitivity and allowed the use of smaller sample mass in comparison with X-Band. Finally, the restoration process performed on a tooth after extraction of the 25 mg of enamel is described. This was conducted by dental treatment using photopolymerizable resin which enabled complete recovery of the tooth from the functional and aesthetic viewpoint showing that this procedure can be minimally invasive.

Topics in broken supersymmetry

International Nuclear Information System (INIS)

Lee, I.H.

1984-01-01

Studies on two topics in the framework of broken supersymmetry are presented. Chapter I is a brief introduction in which the motivation and the background of this work are discussed. In Chapter II, the author studies the decay K + → π + γγ in models with spontaneous supersymmetry breaking and find that it is generally suppressed relative to the decay K + → π + anti nu nu of the conventional model, except possibly for a class of models where the scalar quark masses are generated by radiative corrections from a much larger supersymmetry breaking scale. For a small range of scalar quark and photino mass parameters, the cascade decay process K + → π + π 0 → π + γγ will become dominant over the anti nu nu mode. The author also comments on the possibility of probing the neutrino mass through the K + → π + π 0 → π + anti nu nu cascade decay. Chapter III is concerned with the implications of explicit lepton number violating soft operators in a general low energy effective theory with softly broken supersymmetry

Absorption spectra of H2-H2 pairs in the fundamental band

International Nuclear Information System (INIS)

Meyer, W.; Borysow, A.; Frommhold, L.

1989-01-01

For the computation of the induced-dipole moment, the collisional complex consisting of two H 2 molecules is treated like one molecule in the self-consistent-field and size-consistent, coupled electron pair approximations that separates correctly at distant range. The basis set accounts for 95% of the correlation energies. The radial transition matrix elements of the induced-dipole components are obtained for the two cases v 1 =v 2 =0 and v 1 =0,v 2 =1, where the v i are the vibrational quantum numbers of the interacting H 2 molecules (i=1 or 2). The dependence of these elements on the most important rotational states (j 1 , j 1 ',j 2 ,j 2 '=0,...,3) involved is obtained and seen to be significant in the fundamental band. The results are recast in a simple, but accurate analytical form that is used in a quantum formalism for computations of the spectral moments (sum rules) and line shapes of the collision-induced absorption spectra of molecular hydrogen pairs in the infrared 2.4-μm band. The calculations are based on a proven isotropic potential model that we have extended to account for effects of vibrational excitations. Numerical consistency of the line-shape calculations with the sum rules is observed at the 1% level. The comparison of the computational results with the available measurements at temperatures from 20 to 300 K shows agreement within the estimated uncertainties of the best measurements (∼10%). This fact suggests that theory is capable of predicting these spectra reliably at temperatures for which no measurements exist, with an accuracy that compares favorably with that of good laboratory measurements

Particle-number conserving analysis for the 2-quasiparticle and high-K multi-quasiparticle states in doubly-odd 174,176Lu

International Nuclear Information System (INIS)

Li Bingheng; Lei Yi'an; Zhang Zhenhua

2013-01-01

Two-quasiparticle bands and low-lying excited high-K four-, six-, and eight-quasiparticle bands in the doubly-odd 174,176 Lu are analyzed by using the cranked shell model (CSM) with the pairing correlations treated by a particle-number conserving (PNC) method, in which the blocking effects are taken into account exactly. The proton and neutron Nilsson level schemes for 174,176 Lu are taken from the adjacent odd-A Lu and Hf isotopes, which are adopted to reproduce the experimental bandhead energies of the one-quasiproton and one-quasineutron bands of these odd-A Lu and Hf nuclei, respectively. Once the quasiparticle configurations are determined, the experimental bandhead energies and the moments of inertia of these two- and multi-quasiparticle bands are well reproduced by PNC-CSM calculations. The Coriolis mixing of the low-K (K=|Ω 1 -Ω 2 |) two-quasiparticle band of the Gallagher-Moszkowski doublet with one nucleon in the Ω=1/2 orbital is analyzed. (authors)

Energy Band Gap, Intrinsic Carrier Concentration and Fermi Level of CdTe Bulk Crystal between 304 K and 1067 K

Science.gov (United States)

Su, Ching-Hua

2007-01-01

Optical transmission measurements were performed on CdTe bulk single crystal. It was found that when a sliced and polished CdTe wafer was used, a white film started to develop when the sample was heated above 530 K and the sample became opaque. Therefore, a bulk crystal of CdTe was first grown in the window area by physical vapor transport; the optical transmission was then measured and from which the energy band gap was derived between 304 and 1067 K. The band gaps of CdTe can be fit well as a function of temperature using the Varshini expression: Eg (e V) = 1.5860 - 5.9117xl0(exp -4) T(sup 2)/(T + 160). Using the band gap data, the high temperature electron-hole equilibrium was calculated numerically by assuming the Kane's conduction band structure and a heavy-hole parabolic valance band. The calculated intrinsic carrier concentrations agree well with the experimental data reported previously. The calculated intrinsic Fermi levels between 270 and 1200 K were also presented.

Electron-hole pairing and anomalous properties of layered high-Tc compounds

International Nuclear Information System (INIS)

Efetov, K.B.

1991-01-01

Band-structure pictures for layered high-T c materials available in the literature show that, besides the dispersive broad band responsible for metallic properties, there are at least two additional bands having minima and maxima near the Fermi surface. These additional bands belong to different planes (for example, CuO planes and BiO planes in Bi 2 Sr 2 CaCu 2 O 8 ) or to planes and chains (in YBa 2 Cu 3 O 7 ). Provided the Coulomb repulsion is not very weak, pairing of electrons and holes belonging to these additional bands in different planes or planes and chains is possible. It is shown that, if this possibility is realized, a transition in the additional bands into a state of an excitonic dielectric occurs. The spin of an electron-hole pair can be both 0 and 1. Due to the fact that the electron and the hole of the pair belong to different planes, there are no charge- or spin-density waves. This excitonic insulator can serve as a polarizing substance and give a strong attraction between electrons of the metallic band even if the bare interaction is repulsive. It is also shown that some interesting gapless excitations exist. Provided there are impurities in the system that scatter from plane to plane, these excitations are coupled to the electrons of the metallic band. This effective interaction can be described in terms of an effective mode P(ω) with ImP(ω)∼-sgnω. As a result, one can obtain such properties of the normal state as a linear dependence of the resistivity on temperature, linear dependence of the density of states on energy, constant background in the Raman-scattering intensity, large nuclear relaxation rate, etc., which are very well known from experiments

Band structure of ABC-trilayer graphene superlattice

International Nuclear Information System (INIS)

Uddin, Salah; Chan, K. S.

2014-01-01

We investigate the effect of one-dimensional periodic potentials on the low energy band structure of ABC trilayer graphene first by assuming that all the three layers have the same potential. Extra Dirac points having the same electron hole crossing energy as that of the original Dirac point are generated by superlattice potentials with equal well and barrier widths. When the potential height is increased, the numbers of extra Dirac points are increased. The dispersions around the Dirac points are not isotropic. It is noted that the dispersion along the k y direction for k x  = 0 oscillates between a non-linear dispersion and a linear dispersion when the potential height is increased. When the well and barrier widths are not identical, the symmetry of the conduction and valence bands is broken. The extra Dirac points are shifted either upward or downward depending on the barrier and well widths from the zero energy, while the position of the central Dirac point oscillates with the superlattice potential height. By considering different potentials for different layers, extra Dirac points are generated not from the original Dirac points but from the valleys formed in the energy spectrum. Two extra Dirac points appear from each pair of touched valleys, so four Dirac points appeared in the spectrum at particular barrier height. By increasing the barrier height of superlattice potential two Dirac points merge into the original Dirac point. This emerging and merging of extra Dirac points is different from the equal potential case

Multi-Band (K- Q- and E-Band) Multi-Tone Millimeter-Wave Frequency Synthesizer for Radio Wave Propagation Studies

Science.gov (United States)

Simons, Rainee N.; Wintucky, Edwin G.

2014-01-01

This paper presents the design and test results of a multi-band multi-tone millimeter-wave frequency synthesizer, based on a solid-state frequency comb generator. The intended application of the synthesizer is in a space-borne transmitter for radio wave atmospheric studies at K-band (18 to 26.5 GHz), Q-band (37 to 42 GHz), and E-band (71 to 76 GHz). These studies would enable the design of robust multi-Gbps data rate space-to-ground satellite communication links. Lastly, the architecture for a compact multi-tone beacon transmitter, which includes a high frequency synthesizer, a polarizer, and a conical horn antenna, has been investigated for a notional CubeSat based space-to-ground radio wave propagation experiment.

Properties of entangled photon pairs generated in one-dimensional nonlinear photonic-band-gap structures

International Nuclear Information System (INIS)

Perina, Jan Jr.; Centini, Marco; Sibilia, Concita; Bertolotti, Mario; Scalora, Michael

2006-01-01

We have developed a rigorous quantum model of spontaneous parametric down-conversion in a nonlinear 1D photonic-band-gap structure based upon expansion of the field into monochromatic plane waves. The model provides a two-photon amplitude of a created photon pair. The spectra of the signal and idler fields, their intensity profiles in the time domain, as well as the coincidence-count interference pattern in a Hong-Ou-Mandel interferometer are determined both for cw and pulsed pumping regimes in terms of the two-photon amplitude. A broad range of parameters characterizing the emitted down-converted fields can be used. As an example, a structure composed of 49 layers of GaN/AlN is analyzed as a suitable source of photon pairs having high efficiency

Valley-dependent band structure and valley polarization in periodically modulated graphene

Science.gov (United States)

Lu, Wei-Tao

2016-08-01

The valley-dependent energy band and transport property of graphene under a periodic magnetic-strained field are studied, where the time-reversal symmetry is broken and the valley degeneracy is lifted. The considered superlattice is composed of two different barriers, providing more degrees of freedom for engineering the electronic structure. The electrons near the K and K' valleys are dominated by different effective superlattices. It is found that the energy bands for both valleys are symmetric with respect to ky=-(AM+ξ AS) /4 under the symmetric superlattices. More finite-energy Dirac points, more prominent collimation behavior, and new crossing points are found for K' valley. The degenerate miniband near the K valley splits into two subminibands and produces a new band gap under the asymmetric superlattices. The velocity for the K' valley is greatly renormalized compared with the K valley, and so we can achieve a finite velocity for the K valley while the velocity for the K' valley is zero. Especially, the miniband and band gap could be manipulated independently, leading to an increase of the conductance. The characteristics of the band structure are reflected in the transmission spectra. The Dirac points and the crossing points appear as pronounced peaks in transmission. A remarkable valley polarization is obtained which is robust to the disorder and can be controlled by the strain, the period, and the voltage.

Theoretical understanding on the v(1)-SO4(2-) band perturbed by the formation of magnesium sulfate ion pairs.

Science.gov (United States)

Zhang, Hao; Zhang, Yun-Hong; Wang, Feng

2009-02-01

The factors determining the spectroscopic characteristics of the v(1)-SO4(2-) band of the MgSO4 ion pairs are discussed via ab initio calculation, including coupling effect, hydrogen bonding effect, and direct contact effect of Mg2+ with SO4(2-). With the calculation of the heavy water hydrated contact ion pairs (CIP), the overlap between the librations of water and the v(1)-SO4(2-) band can be separated, and thus the coupling effect is abstracted, and this coupling effect leads to a blue shift for the v(1)-SO4(2-) band of 5.6 cm(-1) in the monodentate CIP and 3.6 cm(-1) in the bidentate CIP. The hydrogen bonding between each water molecule without relation to Mg2+ and the sulfate ion makes the v(1)-SO4(2-) band blue shift of 3.7 cm(-1). When the outer-sphere water around Mg2+ are hydrogen bonded between SO4(2-) and Mg2+, it will make the largest disturbance to the v(1)-SO4(2-) band. Moreover, the inner-sphere water can affect the v(1)-SO4(2-) band conjunct with the direct contact of Mg2+ with SO4(2-), showing a blue shift of 14.4 cm(-1) in the solvent-shared ion pair, 22.6 cm(-1) in the monodentate CIP, 4.3 cm(-1) in the bidentate CIP, and 21.4 cm(-1) in the tridentate CIP. At last, the Raman spectral evolution in the efflorescence production process is tried to be rationalized. The shoulder at 995 cm(-1) is attributed to the monodentate CIP with 2-3 outer-sphere water molecules, whereas the new peak at 1021 cm(-1) at high concentration is assigned to the formation of aqueous triple ion.

Generation of narrow-band polarization-entangled photon pairs at a rubidium D1 line

International Nuclear Information System (INIS)

Tian Long; Li Shujing; Yuan Haoxiang; Wang Hai

2016-01-01

Using the process of cavity-enhanced spontaneous parametric down-conversion (SPDC), we generate a narrow-band polarization-entangled photon pair resonant on the rubidium (Rb) D1 line (795 nm). The degenerate single-mode photon pair is selected by multiple temperature controlled etalons. The linewidth of generated polarization-entangled photon pairs is 15 MHz which matches the typical atomic memory bandwidth. The measured Bell parameter for the polarization-entangled photons S = 2.73 ± 0.04 which violates the Bell-CHSH inequality by ∼18 standard deviations. The presented entangled photon pair source could be utilized in quantum communication and quantum computing based on quantum memories in atomic ensemble. (author)

Kπ=1+ pairing interaction and moments of inertia of superdeformed rotational bands in atomic nuclei

International Nuclear Information System (INIS)

Hamamoto, I.; Nazarewicz, W.

1994-01-01

The effect of the pairing interaction coming from the rotationally induced K π =1 + pair-density on the nuclear moments of inertia is studied. It is pointed out that, contrary to the situation at normal deformations, the inclusion of the K π =1 + pairing may appreciably modify the frequency dependence of the moments of inertia at superdeformed shapes

Drell-Yan lepton pair production at high energies in the k{sub T}-factorization approach

Energy Technology Data Exchange (ETDEWEB)

Lipatov, A.V.; Malyshev, M.A.; Zotov, N.P. [M.V. Lomonosov Moscow State Univ. (Russian Federation). D.V. Skobeltsyn Inst. of Nuclear Physics

2011-11-15

In the framework of the k{sub T}-factorization approach, the production of unpolarized Drell-Yan lepton pair at high energies is studied. The consideration is based on the O({alpha}) and O({alpha}{alpha}{sub s}) off-shell partonic matrix elements with virtual photon {gamma}{sup *} and Z boson exchange. The calculations include leptonic decays of Z bosons with full spin correlations as well as {gamma}{sup *}-Z interference. The unintegrated parton densities in a proton are determined by the Kimber-Martin-Ryskin prescription. Our numerical predictions are compared with the data taken by the D diameter, CDF and CMS collaborations at the Tevatron and LHC energies. Special attention is put on the specific angular distributions measured very recently by the CDF collaboration for the first time. (orig.)

Close near-degeneracy in a pair of four-quasiparticle bands in 194Tl

International Nuclear Information System (INIS)

Masiteng, P.L.; Lawrie, E.A.; Ramashidzha, T.M.; Bark, R.A.; Carlsson, B.G.; Lawrie, J.J.; Lindsay, R.; Komati, F.; Kau, J.; Maine, P.; Maliage, S.M.; Matamba, I.; Mullins, S.M.; Murray, S.H.T.; Mutshena, K.P.; Pasternak, A.A.; Ragnarsson, I.

2013-01-01

A pair of rotational bands associated with the πh 9/2 ⊗νi 13/2 −1 configuration at lower spins and with the πh 9/2 ⊗νi 13/2 −3 configuration at higher spins is found in 194 Tl. The two 4-quasiparticle bands show exceptionally close near-degeneracy in the excitation energies. Furthermore close similarity is also found in their alignments and B(M1)/B(E2) reduced transition probability ratios. Such close near-degeneracy probably indicates chiral geometry in the angular momentum space

Broken Arm

Science.gov (United States)

... of falling — including football, soccer, gymnastics, skiing and skateboarding — also increases the risk of a broken arm. ... for high-risk activities, such as in-line skating, snowboarding, rugby and football. Don't smoke. Smoking ...

ESR dating at K and X band of northeastern Brazilian megafauna

International Nuclear Information System (INIS)

Kinoshita, Angela; Magnolia Franca, Alcina; Augusto Costa de Almeida, Jose; Maria Figueiredo, Ana; Nicolucci, Patricia; Graeff, Carlos F.O.; Baffa, Oswaldo

2005-01-01

The archaeological dose (AD) was measured in three tooth samples of giant mammals that belonged to Brazilian megafauna using electron spin resonance (ESR) spectroscopy at X-band (ν ∼9.5GHz) and K-band (ν ∼24GHz). Samples were collected in Lagoa de Dentro, Puxinana city in Paraiba, a northeast state in Brazil and were identified as Haplomastodon waringi (Holland) (two teeth) and one tooth sample of Xenorhinotherium bahiense (Cartele and Lessa). The average AD led to an age for the Haplomastodon samples of 11.6kybp. For one sample (Haplomastodon) K-band was also employed to evaluate the AD. The K-band spectrum had three components, determined using spectral simulation as follows: a wide isotropic line with g factor 2.0048, an orthorhombic line with gx=2.0034, gy=2.0022 and gz=1.9974, and another isotropic line with g factor 2.0008. The amplitude of these three signals increase with the added dose and the average dose found was 26+/-5Gy. This result is compatible with the AD determined with X-band 21+/-3Gy

The USNO-UKIRT K-band Hemisphere Survey

Science.gov (United States)

Dahm, Scott; Bruursema, Justice; Munn, Jeffrey A.; Vrba, Fred J.; Dorland, Bryan; Dye, Simon; Kerr, Tom; Varricatt, Watson; Irwin, Mike; Lawrence, Andy; McLaren, Robert; Hodapp, Klaus; Hasinger, Guenther

2018-01-01

We present initial results from the United States Naval Observatory (USNO) and UKIRT K-band Hemisphere Survey (U2HS), currently underway using the Wide Field Camera (WFCAM) installed on UKIRT on Maunakea. U2HS is a collaborative effort undertaken by USNO, the Institute for Astronomy, University of Hawaii, the Cambridge Astronomy Survey Unit (CASU) and the Wide Field Astronomy Unit (WFAU) in Edinburgh. The principal objective of the U2HS is to provide continuous northern hemisphere K-band coverage over a declination range of δ=0o – +60o by combining over 12,700 deg2 of new imaging with the existing UKIRT Infrared Deep Sky Survey (UKIDSS) Large Area Survey (LAS), Galactic Plane Survey (GPS) and Galactic Cluster Survey (GCS). U2HS will achieve a 5-σ point source sensitivity of K~18.4 mag (Vega), over three magnitudes deeper than the Two Micron All Sky Survey (2MASS). In this contribution we discuss survey design, execution, data acquisition and processing, photometric calibration and quality control. The data obtained by the U2HS will be made publicly available through the Wide Field Science Archive (WSA) maintained by the WFAU.

Effects of interlayer Sn-Sn lone pair interaction on the band gap of bulk and nanosheet SnO

Science.gov (United States)

Umezawa, Naoto; Zhou, Wei

2015-03-01

Effects of interlayer lone-pair interactions on the electronic structure of SnO are firstly explored by the density-functional theory. Our comprehensive study reveals that the band gap of SnO opens as increase in the interlayer Sn-Sn distance. The effect is rationalized by the character of band edges which consists of bonding and anti-bonding states from interlayer lone pair interactions. The band edges for several nanosheets and strained double-layer SnO are estimated. We conclude that the double-layer SnO is a promising material for visible-light driven photocatalyst for hydrogen evolution. This work is supported by the Japan Science and Technology Agency (JST) Precursory Research for Embryonic Science and Technology (PRESTO) program.

LOCAL BENCHMARKS FOR THE EVOLUTION OF MAJOR-MERGER GALAXIES-SPITZER OBSERVATIONS OF A K-BAND SELECTED SAMPLE

International Nuclear Information System (INIS)

Xu, C. Kevin; Cheng Yiwen; Lu Nanyao; Mazzarella, Joseph M.; Cutri, Roc; Domingue, Donovan; Huang Jiasheng; Gao Yu; Sun, W.-H.; Surace, Jason

2010-01-01

We present Spitzer observations for a sample of close major-merger galaxy pairs (KPAIR sample) selected from cross-matches between the Two Micron All Sky Survey and Sloan Digital Sky Survey Data Release 3. The goals are to study the star formation activity in these galaxies and to set a local bench mark for the cosmic evolution of close major mergers. The Spitzer KPAIR sample (27 pairs, 54 galaxies) includes all spectroscopically confirmed spiral-spiral (S+S) and spiral-elliptical (S+E) pairs in a parent sample that is complete for primaries brighter than K = 12.5 mag, projected separations of 5 h -1 kpc ≤ s ≤ 20 h -1 kpc, and mass ratios ≤2.5. The Spitzer data, consisting of images in seven bands (3.6, 4.5, 5.8, 8, 24, 70, 160 μm), show very diversified IR emission properties. Compared to single spiral galaxies in a control sample, only spiral galaxies in S+S pairs show significantly enhanced specific star formation rate (sSFR = SFR/M), whereas spiral galaxies in S+E pairs do not. Furthermore, the SFR enhancement of spiral galaxies in S+S pairs is highly mass-dependent. Only those with M ∼> 10 10.5 M sun show significant enhancement. Relatively low-mass (M ∼ 10 10 M sun ) spirals in S+S pairs have about the same SFR/M compared to their counterparts in the control sample, while those with 10 11 M sun have on average a ∼3 times higher SFR/M than single spirals. There is evidence for a correlation between the global star formation activities (but not the nuclear activities) of the component galaxies in massive S+S major-merger pairs (the H olmberg effect ) . There is no significant difference in the SFR/M between the primaries and the secondaries, nor between spirals of SEP KPAIR =2.54 x 10 -4 (M sun yr -1 Mpc -3 ).

Group theoretical classification of broken symmetry states of the two-fold degenerate Hubbard model on a triangular lattice

International Nuclear Information System (INIS)

Masago, Akira; Suzuki, Naoshi

2001-01-01

By a group theoretical procedure we derive the possible spontaneously broken-symmetry states for the two-fold degenerate Hubbard model on a two-dimensional triangular lattice. For ordering wave vectors corresponding to the points Γ and K in the first BZ we find 22 states which include 16 collinear and six non-collinear states. The collinear states include the usual SDW and CDW states which appear also in the single-band Hubbard model. The non-collinear states include exotic ordering states of orbitals and spins as well as the triangular arrangement of spins

Superconducting correlations in the one- and two-band Hubbard models

International Nuclear Information System (INIS)

Jain, K.P.; Ramakumar, R.; Chancey, C.C.

1989-01-01

An approximate expression is derived for the generalized energy gap function Δ kμ for a system of interacting electrons in a narrow s-band. This function has the virtue that it interpolates between the weak interaction limit (BCS) and the intermediate coupling regime. Starting from the Cooper pairing state, the authors investigate the build-up of pairing correlations and study the properties of the generalized gap in these two regimes as a function of the band filling. The coupled equations for the gap and the band filling define the self-consistency conditions. A recent extension of this analysis to the two-band model is also discussed

High-Efficiency K-Band Space Traveling-Wave Tube Amplifier for Near-Earth High Data Rate Communications

Science.gov (United States)

Simons, Rainee N.; Force, Dale A.; Spitsen, Paul C.; Menninger, William L.; Robbins, Neal R.; Dibb, Daniel R.; Todd, Phillip C.

2010-01-01

The RF performance of a new K-Band helix conduction cooled traveling-wave tube amplifier (TWTA), is presented in this paper. A total of three such units were manufactured, tested and delivered. The first unit is currently flying onboard NASA's Lunar Reconnaissance Orbiter (LRO) spacecraft and has flawlessly completed over 2000 orbits around the Moon. The second unit is a proto-flight model. The third unit will fly onboard NASA's International Space Station (ISS) as a very compact and lightweight transmitter package for the Communications, Navigation and Networking Reconfigurable Testbed (CoNNeCT), which is scheduled for launch in 2011. These TWTAs were characterized over the frequencies 25.5 to 25.8 GHz. The saturated RF output power is greater than 40 W and the saturated RF gain is greater than 46 dB. The saturated AM-to-PM conversion is 3.5 /dB and the small signal gain ripple is 0.46 dB peak-to-peak. The overall efficiency of the TWTA, including that of the electronic power conditioner (EPC) is as high as 45%.

A K/Ka band radiating element for Tx/Rx phased array

KAUST Repository

Sandhu, Ali Imran; Arnieri, E.; Amendola, G.; Boccia, L.; Meniconi, E.; Ziegler, V.

2017-01-01

The paper presents a K/Ka band radiating element for TX/RX phased arrays. Dual band operations is obtained using a single radiating surface: a novel radiator is adopted and placed in a configuration in which dual band and single band elements are interleaved. The array elements are optimized to scan the beam in excess of 50° in both bands. A subarray with 49 Rx elements and 105 Tx elements was built and measured confirming the results obtained in simulations.

A K/Ka band radiating element for Tx/Rx phased array

KAUST Repository

Sandhu, Ali Imran

2017-01-20

The paper presents a K/Ka band radiating element for TX/RX phased arrays. Dual band operations is obtained using a single radiating surface: a novel radiator is adopted and placed in a configuration in which dual band and single band elements are interleaved. The array elements are optimized to scan the beam in excess of 50° in both bands. A subarray with 49 Rx elements and 105 Tx elements was built and measured confirming the results obtained in simulations.

Ferroelectric switch for a high-power Ka-band active pulse compressor

Energy Technology Data Exchange (ETDEWEB)

Hirshfield, Jay L. [Omega-P, Inc., New Haven, CT (United States)

2013-12-18

Results are presented for design of a high-power microwave switch for operation at 34.3 GHz, intended for use in an active RF pulse compressor. The active element in the switch is a ring of ferroelectric material, whose dielectric constant can be rapidly changed by application of a high-voltage pulse. As envisioned, two of these switches would be built into a pair of delay lines, as in SLED-II at SLAC, so as to allow 30-MW μs-length Ka-band pulses to be compressed in time by a factor-of-9 and multiplied in amplitude to generate 200 MW peak power pulses. Such high-power pulses could be used for testing and evaluation of high-gradient mm-wave accelerator structures, for example. Evaluation of the switch design was carried out with an X-band (11.43 GHz) prototype, built to incorporate all the features required for the Ka-band version.

Enhanced coherence within the theta band between pairs of brains engaging in experienced versus naïve Reiki procedures.

Science.gov (United States)

Ventura, Anabela Carraca; Persinger, Michael A

2014-08-01

The study objective was to discern whether the coherence between brain activities of the "patient" and practitioner differ between Reiki experts and novices. If the physical process associated with Reiki involves "convergence" between the practitioner and subject, then this congruence should be evident in time-dependent shared power within specific and meaningful frequency electroencephalographic bands. Simultaneous quantitative electroencephalogram measures (19 channels) were recorded from 9 pairs of subjects when 1 of the pairs was an experienced Reiki practitioner or had just been shown the procedure. Pairs recorded their experiences and images. The "practitioner" and "patient" pairs were measured within a quiet, comfortable acoustic chamber. Real-time correlations and coherence between pairs of brains for power (μV(2)·Hz(-1)) within the various frequency bands over the 10-min sessions were recorded and analyzed for each pair. Descriptors of experiences were analyzed for word meanings. Only the coherence within the theta range increased over time between the brains of the Reiki pairs relative to the Sham pairs, particularly over the left hemisphere. The pleasantness-unpleasantness rating for the words employed to describe experiences written after the experiment were more congruent for the Reiki pairs compared to the reference pairs. The increased synchronization of the cerebral activity of the participant and the practitioner during proximal therapies involving touch such as Reiki may be an important component of any subsequent beneficial effects.

Valence band structure of binary chalcogenide vitreous semiconductors by high-resolution XPS

International Nuclear Information System (INIS)

Kozyukhin, S.; Golovchak, R.; Kovalskiy, A.; Shpotyuk, O.; Jain, H.

2011-01-01

High-resolution X-ray photoelectron spectroscopy (XPS) is used to study regularities in the formation of valence band electronic structure in binary As x Se 100−x , As x S 100−x , Ge x Se 100−x and Ge x S 100−x chalcogenide vitreous semiconductors. It is shown that the highest occupied energetic states in the valence band of these materials are formed by lone pair electrons of chalcogen atoms, which play dominant role in the formation of valence band electronic structure of chalcogen-rich glasses. A well-expressed contribution from chalcogen bonding p electrons and more deep s orbitals are also recorded in the experimental valence band XPS spectra. Compositional dependences of the observed bands are qualitatively analyzed from structural and compositional points of view.

Valence band structure of binary chalcogenide vitreous semiconductors by high-resolution XPS

Energy Technology Data Exchange (ETDEWEB)

Kozyukhin, S., E-mail: sergkoz@igic.ras.ru [Russian Academy of Science, Institute of General and Inorganic Chemistry (Russian Federation); Golovchak, R. [Lviv Scientific Research Institute of Materials of SRC ' Carat' (Ukraine); Kovalskiy, A. [Lehigh University, Department of Materials Science and Engineering (United States); Shpotyuk, O. [Lviv Scientific Research Institute of Materials of SRC ' Carat' (Ukraine); Jain, H. [Lehigh University, Department of Materials Science and Engineering (United States)

2011-04-15

High-resolution X-ray photoelectron spectroscopy (XPS) is used to study regularities in the formation of valence band electronic structure in binary As{sub x}Se{sub 100-x}, As{sub x}S{sub 100-x}, Ge{sub x}Se{sub 100-x} and Ge{sub x}S{sub 100-x} chalcogenide vitreous semiconductors. It is shown that the highest occupied energetic states in the valence band of these materials are formed by lone pair electrons of chalcogen atoms, which play dominant role in the formation of valence band electronic structure of chalcogen-rich glasses. A well-expressed contribution from chalcogen bonding p electrons and more deep s orbitals are also recorded in the experimental valence band XPS spectra. Compositional dependences of the observed bands are qualitatively analyzed from structural and compositional points of view.

Features of carrier tunneling between the silicon valence band and metal in devices based on the Al/high-K oxide/SiO_2/Si structure

International Nuclear Information System (INIS)

Vexler, M. I.; Grekhov, I. V.

2016-01-01

The features of electron tunneling from or into the silicon valence band in a metal–insulator–semiconductor system with the HfO_2(ZrO_2)/SiO_2 double-layer insulator are theoretically analyzed for different modes. It is demonstrated that the valence-band current plays a less important role in structures with HfO_2(ZrO_2)/SiO_2 than in structures containing only silicon dioxide. In the case of a very wide-gap high-K oxide ZrO_2, nonmonotonic behavior related to tunneling through the upper barrier is predicted for the valence-band–metal current component. The use of an insulator stack can offer certain advantages for some devices, including diodes, bipolar tunnel-emitter transistors, and resonant-tunneling diodes, along with the traditional use of high-K insulators in a field-effect transistor.

Quantum Multicriticality near the Dirac-Semimetal to Band-Insulator Critical Point in Two Dimensions: A Controlled Ascent from One Dimension

Directory of Open Access Journals (Sweden)

Bitan Roy

2018-03-01

Full Text Available We compute the effects of generic short-range interactions on gapless electrons residing at the quantum critical point separating a two-dimensional Dirac semimetal and a symmetry-preserving band insulator. The electronic dispersion at this critical point is anisotropic (E_{k}=±sqrt[v^{2}k_{x}^{2}+b^{2}k_{y}^{2n}] with n=2, which results in unconventional scaling of thermodynamic and transport quantities. Because of the vanishing density of states [ϱ(E∼|E|^{1/n}], this anisotropic semimetal (ASM is stable against weak short-range interactions. However, for stronger interactions, the direct Dirac-semimetal to band-insulator transition can either (i become a fluctuation-driven first-order transition (although unlikely in a particular microscopic model considered here, the anisotropic honeycomb lattice extended Hubbard model or (ii get avoided by an intervening broken-symmetry phase. We perform a controlled renormalization group analysis with the small parameter ε=1/n, augmented with a 1/n expansion (parametrically suppressing quantum fluctuations in the higher dimension by perturbing away from the one-dimensional limit, realized by setting ε=0 and n→∞. We identify charge density wave (CDW, antiferromagnet (AFM, and singlet s-wave superconductivity as the three dominant candidates for broken symmetry. The onset of any such order at strong coupling (∼ε takes place through a continuous quantum phase transition across an interacting multicritical point, where the ordered phase, band insulator, Dirac, and anisotropic semimetals meet. We also present the phase diagram of an extended Hubbard model for the ASM, obtained via the controlled deformation of its counterpart in one dimension. The latter displays spin-charge separation and instabilities to CDW, spin density wave, and Luther-Emery liquid phases at arbitrarily weak coupling. The spin density wave and Luther-Emery liquid phases deform into pseudospin SU(2-symmetric quantum critical

Electronic States of High-k Oxides in Gate Stack Structures

Science.gov (United States)

Zhu, Chiyu

In this dissertation, in-situ X-ray and ultraviolet photoemission spectroscopy have been employed to study the interface chemistry and electronic structure of potential high-k gate stack materials. In these gate stack materials, HfO2 and La2O3 are selected as high-k dielectrics, VO2 and ZnO serve as potential channel layer materials. The gate stack structures have been prepared using a reactive electron beam system and a plasma enhanced atomic layer deposition system. Three interrelated issues represent the central themes of the research: 1) the interface band alignment, 2) candidate high-k materials, and 3) band bending, internal electric fields, and charge transfer. 1) The most highlighted issue is the band alignment of specific high-k structures. Band alignment relationships were deduced by analysis of XPS and UPS spectra for three different structures: a) HfO2/VO2/SiO2/Si, b) HfO 2-La2O3/ZnO/SiO2/Si, and c) HfO 2/VO2/ HfO2/SiO2/Si. The valence band offset of HfO2/VO2, ZnO/SiO2 and HfO 2/SiO2 are determined to be 3.4 +/- 0.1, 1.5 +/- 0.1, and 0.7 +/- 0.1 eV. The valence band offset between HfO2-La2O3 and ZnO was almost negligible. Two band alignment models, the electron affinity model and the charge neutrality level model, are discussed. The results show the charge neutrality model is preferred to describe these structures. 2) High-k candidate materials were studied through comparison of pure Hf oxide, pure La oxide, and alloyed Hf-La oxide films. An issue with the application of pure HfO2 is crystallization which may increase the leakage current in gate stack structures. An issue with the application of pure La2O3 is the presence of carbon contamination in the film. Our study shows that the alloyed Hf-La oxide films exhibit an amorphous structure along with reduced carbon contamination. 3) Band bending and internal electric fields in the gate stack structure were observed by XPS and UPS and indicate the charge transfer during the growth and process. The oxygen

A broken symmetry ontology: Quantum mechanics as a broken symmetry

International Nuclear Information System (INIS)

Buschmann, J.E.

1988-01-01

The author proposes a new broken symmetry ontology to be used to analyze the quantum domain. This ontology is motivated and grounded in a critical epistemological analysis, and an analysis of the basic role of symmetry in physics. Concurrently, he is led to consider nonheterogeneous systems, whose logical state space contains equivalence relations not associated with the causal relation. This allows him to find a generalized principle of symmetry and a generalized symmetry-conservation formalisms. In particular, he clarifies the role of Noether's theorem in field theory. He shows how a broken symmetry ontology already operates in a description of the weak interactions. Finally, by showing how a broken symmetry ontology operates in the quantum domain, he accounts for the interpretational problem and the essential incompleteness of quantum mechanics. He proposes that the broken symmetry underlying this ontological domain is broken dilation invariance

A comprehensive study on gain stabilization of Er-doped fiber amplifier in C-band with uniform fiber Bragg grating-pair

Science.gov (United States)

Yang, Jiuru; Ma, Yu; OuYang, Yunlun; Liu, Chunyu; Zhang, Jiaxiao

2014-07-01

Fiber grating-pair is one of the efficient methods for gain stabilization of erbium doped fiber amplifier (EDFA) but with a gain-reduction of signals, especially in C-band. In order to overcome it, in this article, we establish a configuration of EDFA based uniform fiber grating-pair and conduct a comprehensive study on gain stabilization by varying the reflectivity, center wavelength and 3dB bandwidth of grating, and by varying the channel number and pump power. The numerical results show that under the optimal parameters of grating the gain stabilization at 1550nm is +/-0.044dB with high gain and large dynamic range.

An entropy-based improved k-top scoring pairs (TSP) method for ...

African Journals Online (AJOL)

An entropy-based improved k-top scoring pairs (TSP) (Ik-TSP) method was presented in this study for the classification and prediction of human cancers based on gene-expression data. We compared Ik-TSP classifiers with 5 different machine learning methods and the k-TSP method based on 3 different feature selection ...

Theory of superconductivity. II. Excited Cooper pairs. Why does sodium remain normal down to 0 K?

International Nuclear Information System (INIS)

Fujita, S.

1992-01-01

Based on a generalized BCS Hamiltonian in which the interaction strengths (V 11 , V 22 , V 12 ) among and between electron (12) and hole (2) Cooper pairs are differentiated, the thermodynamic properties of a type-I superconductor below the critical temperature T c are investigated. An expression for the ground-state energy, W - W 0 , relative to the unperturbed Block system is obtained. The usual BCS formulas are obtained in the limits: (all) V jl = V 0 , N 1 (0) = N 2 (0). Any excitations generated through the BCS interaction Hamiltonian containing V jl must involve Cooper pairs of antiparallel spins and nearly opposite momenta. The nonzero momentum or excited Cooper pairs below T c are shown to have an excitation energy band minimum lower than the quasi-electrons, which were regarded as the elementary excitations in the original BCS theory. The energy gap var-epsilon g (T) defined relative to excited and zero-momentum Copper pairs (when V jl > 0) decreases from var-epsilon g (0) to 0 as the temperature T is raised from 0 to T c . If electrons only are available as in a monovalent metal like sodium (V 12 = 0), the energy constant Δ 1 is finite but the energy gap vanishes identically for all T. In agreement with the BCS theory, the present theory predicts that a pure nonmagnetic metal in any dimensions should have a Cooper-pair ground state whose energy is lower than that of the Bloch ground state. Additionally it predicts that a monovalent metal should remain normal down to 0 K, and that there should be no strictly one-dimensional superconductor

Broken bone

Science.gov (United States)

... Drugs & Supplements Videos & Tools Español You Are Here: Home → Medical Encyclopedia → Broken bone URL of this page: //medlineplus.gov/ency/ ... following steps to reduce your risk of a broken bone: Wear protective ... pads. Create a safe home for young children. Place a gate at stairways ...

Microwave absorption properties of flake-shaped Co particles composites at elevated temperature (293-673 K) in X band

Science.gov (United States)

Wang, Guowu; Li, Xiling; Wang, Peng; Zhang, Junming; Wang, Dian; Qiao, Liang; Wang, Tao; Li, Fashen

2018-06-01

The complex permeability and permittivity of the easy-plane anisotropic Co/polyimide composite at high temperature (293-673 K) in X band were measured. The results show that both the complex permeability and permittivity increase with the increase of temperature in the measured temperature range. The calculated absorption properties display that the intensity of the reflection loss (RL) peak first increases and then decreases with the increase of temperature, and reaches the maximum (-52 dB) at 523 K. At each temperature, the composite can achieve the RL exceeding -10 dB in the whole X band. The composite can even work stably for more than 20 min with the excellent absorption performance under 673 K. In addition, the RL performance of the composite at high temperature is better than that at room temperature.

Management of broken instrument by file bypass technique

Directory of Open Access Journals (Sweden)

Sultana Parveen

2017-02-01

Full Text Available Different devices and techniques have been developed to retrieve fractured instruments during the endodontic procedures. This case report describes the management of a broken instrument, which was accidentally broken during cleaning and shaping of the root canal in right 2nd molar tooth. A # 25 stainless steel K-file was separated in mesiobuccal canal of the treated tooth. At first, a radiograph was taken to confirm the level of separation of the instrument. The instrument was found to be separated at the apical 3rd of the mesial canal and then file bypass technique was performed. Calcium hydroxide dressing was given for 7 days followed by obturation with guttapercha cone and zinc oxide eugenol sealer in lateral condensation technique. It can be concluded that bypass technique can be considered as simple and effective technique for the management of broken instrument into the root canal.

Remarks on broken chiral SU(5) x SU(5) symmetry and B mesons

International Nuclear Information System (INIS)

Kim, D.Y.; Sinha, S.N.

1985-01-01

In a recent paper, Hatzis has estimated the masses and weak decay constants of b-flavored pseudoscalar mesons in a broken chiral SU(5) x SU(5) symmetry method. The estimated weak decay constant of B meson, f sub(B) f sub(K)(f sub(B)/f sub(K) approximately equal to 1.4) evaluated by Mathur et al. with the quantum chromodynamics (QCD) sum-rule model. We re-examined the problem applying the broken chiral SU(5) x SU(5) symmetry approach using a set of mass formulae. With this method we estimate the symmetry-breaking parameters and decay constants of pseudoscalar mesons. We found a consistent result for the decay constant: f sub(K) < or approximately equal to f sub(D) < or approximately equal to f sub(B). The explicit numerical value of these constants, however, are lower than that of the QCD sum rule. This may be due to the limited validity of the broken chiral symmetry approach for heavy mesons

Broken Bones (For Parents)

Science.gov (United States)

... Safe Videos for Educators Search English Español Broken Bones KidsHealth / For Parents / Broken Bones What's in this ... bone fragments in place. When Will a Broken Bone Heal? Fractures heal at different rates, depending upon ...

Spectroscopy of metal "superatom" nanoclusters and high-Tc superconducting pairing

Science.gov (United States)

Halder, Avik; Kresin, Vitaly V.

2015-12-01

A unique property of metal nanoclusters is the "superatom" shell structure of their delocalized electrons. The electronic shell levels are highly degenerate and therefore represent sharp peaks in the density of states. This can enable exceptionally strong electron pairing in certain clusters composed of tens to hundreds of atoms. In a finite system, such as a free nanocluster or a nucleus, pairing is observed most clearly via its effect on the energy spectrum of the constituent fermions. Accordingly, we performed a photoionization spectroscopy study of size-resolved aluminum nanoclusters and observed a rapid rise in the near-threshold density of states of several clusters (A l37 ,44 ,66 ,68 ) with decreasing temperature. The characteristics of this behavior are consistent with compression of the density of states by a pairing transition into a high-temperature superconducting state with Tc≳100 K. This value exceeds that of bulk aluminum by two orders of magnitude. These results highlight the potential of novel pairing effects in size-quantized systems and the possibility to attain even higher critical temperatures by optimizing the particles' size and composition. As a new class of high-temperature superconductors, such metal nanocluster particles are promising building blocks for high-Tc materials, devices, and networks.

L-band brightness temperature disaggregation for use with S-band and C-band radiometer data for WCOM

Science.gov (United States)

Yao, P.; Shi, J.; Zhao, T.; Cosh, M. H.; Bindlish, R.

2017-12-01

There are two passive microwave sensors onboard the Water Cycle Observation Mission (WCOM), which includes a synthetic aperture radiometer operating at L-S-C bands and a scanning microwave radiometer operating from C- to W-bands. It provides a unique opportunity to disaggregate L-band brightness temperature (soil moisture) with S-band C-bands radiometer data. In this study, passive-only downscaling methodologies are developed and evaluated. Based on the radiative transfer modeling, it was found that the TBs (brightness temperature) between the L-band and S-band exhibit a linear relationship, and there is an exponential relationship between L-band and C-band. We carried out the downscaling results by two methods: (1) downscaling with L-S-C band passive measurements with the same incidence angle from payload IMI; (2) downscaling with L-C band passive measurements with different incidence angle from payloads IMI and PMI. The downscaling method with L-S bands with the same incident angle was first evaluated using SMEX02 data. The RMSE are 2.69 K and 1.52 K for H and V polarization respectively. The downscaling method with L-C bands is developed with different incident angles using SMEX03 data. The RMSE are 2.97 K and 2.68 K for H and V polarization respectively. These results showed that high-resolution L-band brightness temperature and soil moisture products could be generated from the future WCOM passive-only observations.

Collective dipole rotational bands in the A {approx} 200 region

Energy Technology Data Exchange (ETDEWEB)

Clark, R M; Wadsworth, R; Regan, P H [York Univ. (United Kingdom). Dept. of Physics; Paul, E S; Beausang, C W; Ali, I; Cullen, D M; Dagnall, P J; Fallon, P; Joyce, M J; Sharpey-Schafer, J F [Liverpool Univ. (United Kingdom). Oliver Lodge Lab.; Astier, A; Meyer, M; Redon, N [Lyon-1 Univ., 69 - Villeurbanne (France). Inst. de Physique Nucleaire; Nazakewicz, W; Wyss, R [Joint Inst. for Heavy Ion Research, Oak Ridge, TN (United States)

1992-08-01

Rotational oblate bands consisting of regular sequences of magnetic dipole transitions have recently been identified in {sup 196-200}Pb. Their observation indicates a drastic change in the high-spin configurations between the Hg, Tl and {sup 194}Pb nuclei, in which SD bands are clearly observed, and the heavier Pb isotopes, where these weakly deformed oblate structures see to dominate. Angular correlation ratios show the transitions to be dipoles. Their magnetic nature can be deduced from intensity measurements, and they are characterized by small dynamic moments of inertia. Several of the bands have been interpreted as being built on high-K two-proton configurations coupled to an aligned pair of i{sub 13/2} neutrons in the even A nuclei, and to either one or three i{sub 13/2} neutrons in the odd A nuclei. Cranked shell model calculations predict the alignment of a pair of i{sub 13/2} neutrons (the AB crossing) at {omega} {approx} 0.18 MeV{Dirac_h}{sub -1}. The higher frequency crossing at {omega} {approx} 0.4 MeV{Dirac_h}{sub -1} may be due to the alignment of f{sub 5/2} neutrons, h{sub 11/2} protons, or both. 17 refs., 4 figs.

Observation of band bending of metal/high-k Si capacitor with high energy x-ray photoemission spectroscopy and its application to interface dipole measurement

Science.gov (United States)

Kakushima, K.; Okamoto, K.; Tachi, K.; Song, J.; Sato, S.; Kawanago, T.; Tsutsui, K.; Sugii, N.; Ahmet, P.; Hattori, T.; Iwai, H.

2008-11-01

Band bendings of Si substrates have been observed using hard x-ray photoemission spectroscopy. With a capability of collecting photoelectrons generated as deep as 40 nm, the binding energy shift in a core level caused by the potential profile at the surface of the substrate results in a spectrum broadening. The broadening is found to be significant when heavily doped substrates are used owing to its steep potential profile. The surface potential of the substrate can be obtained by deconvolution of the spectrum. This method has been applied to observe the band bending profile of metal-oxide-semiconductor capacitors with high-k gate dielectrics. By comparing the band bending profiles of heavily-doped n+- and p+-Si substrates, the interface dipoles presented at interfaces can be estimated. In the case of W gated La2O3/La-silicate capacitor, an interface dipole to shift the potential of -0.45 V has been estimated at La-silicate/Si interface, which effectively reduces the apparent work function of W. On the other hand, an interface dipole of 0.03-0.07 V has been found to exist at Hf-silicate/SiO2 interface for W gated HfO2/Hf-silicate/SiO2 capacitor.

Tunneling couplings in discrete lattices, single-particle band structure, and eigenstates of interacting atom pairs

International Nuclear Information System (INIS)

Piil, Rune; Moelmer, Klaus

2007-01-01

By adjusting the tunneling couplings over longer than nearest-neighbor distances, it is possible in discrete lattice models to reproduce the properties of the lowest energy band of a real, continuous periodic potential. We propose to include such terms in problems with interacting particles, and we show that they have significant consequences for scattering and bound states of atom pairs in periodic potentials

Structure of stable degeneration of K3 surfaces into pairs of rational elliptic surfaces

Science.gov (United States)

Kimura, Yusuke

2018-03-01

F-theory/heterotic duality is formulated in the stable degeneration limit of a K3 fibration on the F-theory side. In this note, we analyze the structure of the stable degeneration limit. We discuss whether stable degeneration exists for pairs of rational elliptic surfaces. We demonstrate that, when two rational elliptic surfaces have an identical complex structure, stable degeneration always exists. We provide an equation that systematically describes the stable degeneration of a K3 surface into a pair of isomorphic rational elliptic surfaces. When two rational elliptic surfaces have different complex structures, whether their sum glued along a smooth fiber admits deformation to a K3 surface can be determined by studying the structure of the K3 lattice. We investigate the lattice theoretic condition to determine whether a deformation to a K3 surface exists for pairs of extremal rational elliptic surfaces. In addition, we discuss the configurations of singular fibers under stable degeneration. The sum of two isomorphic rational elliptic surfaces glued together admits a deformation to a K3 surface, the singular fibers of which are twice that of the rational elliptic surface. For special situations, singular fibers of the resulting K3 surface collide and they are enhanced to a fiber of another type. Some K3 surfaces become attractive in these situations. We determine the complex structures and the Weierstrass forms of these attractive K3 surfaces. We also deduce the gauge groups in F-theory compactifications on these attractive K3 surfaces times a K3. E 6, E 7, E 8, SU(5), and SO(10) gauge groups arise in these compactifications.

Exotic superconductivity with enhanced energy scales in materials with three band crossings

Science.gov (United States)

Lin, Yu-Ping; Nandkishore, Rahul M.

2018-04-01

Three band crossings can arise in three-dimensional quantum materials with certain space group symmetries. The low energy Hamiltonian supports spin one fermions and a flat band. We study the pairing problem in this setting. We write down a minimal BCS Hamiltonian and decompose it into spin-orbit coupled irreducible pairing channels. We then solve the resulting gap equations in channels with zero total angular momentum. We find that in the s-wave spin singlet channel (and also in an unusual d-wave `spin quintet' channel), superconductivity is enormously enhanced, with a possibility for the critical temperature to be linear in interaction strength. Meanwhile, in the p-wave spin triplet channel, the superconductivity exhibits features of conventional BCS theory due to the absence of flat band pairing. Three band crossings thus represent an exciting new platform for realizing exotic superconducting states with enhanced energy scales. We also discuss the effects of doping, nonzero temperature, and of retaining additional terms in the k .p expansion of the Hamiltonian.

The Role of Broken Cooper Pairs in Warm Nuclei

International Nuclear Information System (INIS)

Guttormsen, M.; Chankova, R.; Larsen, A.C.; Rekstad, J.; Siem, S.; Syed, N.U.H.; Agvaanluvsan, U.; Schiller, A.; Voinov, A.

2007-01-01

In order to understand warm nuclei and describe the underlying microscopic structure, entropy is measured for several even-even and odd-mass nuclei. Mid-shell nuclei show significant odd-even entropy differences interpreted as the single-particle entropy introduced by the valence nucleon. A method to extract critical temperatures for the pair breaking process is demonstrated. (author)

An extensive analysis of the parity of broken 3-diamond partitions

OpenAIRE

Radu, Silviu; Sellers, James A.

2013-01-01

In 2007, Andrews and Paule introduced the family of functions ? k ( n ) which enumerate the number of broken k-diamond partitions for a fixed positive integer k. Since then, numerous mathematicians have considered partitions congruences satisfied by ? k ( n ) for small values of k. In this work, we provide an extensive analysis of the parity of the function ? 3 ( n ) , including a number of Ramanujan-like congruences modulo 2. This will be accomplished by completely characterizing the values ...

Anisotropic energy-gaps of iron-based superconductivity from intra-band quasiparticle interference in LiFeAs

Energy Technology Data Exchange (ETDEWEB)

Rost, A.W. [LASSP, Department of Physics, Cornell, Ithaca, NY 14853 (United States); SUPA, School of Physics and Astronomy, Univ. of St Andrews, St Andrews, Fife KY16 9SS (United Kingdom); Allan, M.P. [LASSP, Department of Physics, Cornell, Ithaca, NY 14853 (United States); SUPA, School of Physics and Astronomy, Univ. of St Andrews, St Andrews, Fife KY16 9SS (United Kingdom); CMPMS Department, Brookhaven National Laboratory, Upton, NY 11973 (United States); Mackenzie, A.P. [SUPA, School of Physics and Astronomy, Univ. of St Andrews, St Andrews, Fife KY16 9SS (United Kingdom); Xie, Y. [CMPMS Department, Brookhaven National Laboratory, Upton, NY 11973 (United States); Davis, J.C. [LASSP, Department of Physics, Cornell, Ithaca, NY 14853 (United States); SUPA, School of Physics and Astronomy, Univ. of St Andrews, St Andrews, Fife KY16 9SS (United Kingdom); CMPMS Department, Brookhaven National Laboratory, Upton, NY 11973 (United States); Kavli Institute at Cornell for Nanoscale Science, Cornell, Ithaca, NY 14853 (United States); Kihou, K.; Lee, C.H.; Iyo, A.; Eisaki, H. [AIST, Tsukuba, Ibaraki 305-8568 (Japan); Chuang, T.M. [LASSP, Department of Physics, Cornell, Ithaca, NY 14853 (United States); CMPMS Department, Brookhaven National Laboratory, Upton, NY 11973 (United States); Inst. of Physics, Academica Sinica, Nankang, Taipei 11529, Taiwan (China)

2012-07-01

Cooper pairing in the Fe-based superconductors is thought to occur due to the projection of the antiferromagnetic interactions between iron atoms onto the complex momentum-space electronic structure. A key consequence is that distinct anisotropic energy gaps {Delta}{sub i}(k) with specific relative orientations should occur on the different electronic bands i. To determine this previously unresolved gap structure high-precision spectroscopy is required. Here we introduce the STM technique of intra-band Bogolyubov quasiparticle scattering interference (QPI) to iron-based superconductor studies, focusing on LiFeAs. We identify the QPI signatures of three hole-like dispersions and, by introducing a new QPI technique, determine the magnitude and relative orientations of corresponding anisotropic {Delta}{sub i}(k). Intra-band Bogolyubov QPI therefore yields the spectroscopic information required to identify the mechanism of superconductivity in Fe-based superconductors.

Thermionic detection of the ionic fragments of continiuum-state pair absorption systems

International Nuclear Information System (INIS)

Hotop, R.; Niemax, K.; Richter, J.; Weber, K.H.

1981-01-01

Using a thermionic diode we have detected the ionic fragments formed by associative ionization and dissociation after continuum-state pair absorption processes in Cs-Cs and Cs-K systems. Assuming an ionization probability of unity of the excited species and calibrating the pair absorption bands by taking into account the known photoionization cross section of the atoms we found excellent agreement with data from classical absorption measurements. (orig.)

Symmetry restoration in spontaneously broken induced gravity

International Nuclear Information System (INIS)

Amati, D.; Russo, J.

1990-01-01

We investigate the recuperation of expected invariant behaviours in a non-metric gravity theory in which the full general relativistic invariance is broken spontaneously. We show how dangerous increasing energy behaviours of physical amplitudes cancel in a highly non-trivial way. This evidences the expected loss of the vacuum generated scale in the UV regime and gives support for the consistency of spontaneously broken gravity theories. (orig.)

Modified broken rice starch as fat substitute in sausages

Directory of Open Access Journals (Sweden)

Valéria Maria Limberger

2011-09-01

Full Text Available The demand for low-fat beef products has led the food industry to use fat substitutes such as modified starch. About 14% of broken rice is generated during processing. Nevertheless, this by-product contains high levels of starch; being therefore, great raw material for fat substitution. This study evaluated the applicability of chemically and physically modified broken rice starch as fat substitute in sausages. Extruded and phosphorylated broken rice was used in low-fat sausage formulation. All low-fat sausages presented about 55% reduction in the fat content and around 28% reduction in the total caloric value. Fat replacement with phosphorylated and extruded broken rice starch increased the texture acceptability of low-fat sausages, when compared to low-fat sausages with no modified broken rice. Results suggest that modified broken rice can be used as fat substitute in sausage formulations, yielding lower caloric value products with acceptable sensory characteristics.

Banding patterns and chromosomal evolution in five species of neotropical Teiinae lizards (Squamata: Teiidae).

Science.gov (United States)

dos Santos, Rodrigo Marques Lima; Pellegrino, Katia Cristina Machado; Rodrigues, Miguel Trefaut; Yonenaga-Yassuda, Yatiyo

2007-11-01

Karyotypes of five species of South American teiid lizards from subfamily Teiinae: Ameiva ameiva, Kentropyx calcarata, K. paulensis, K. vanzoi (2n = 50, all acrocentric), and Cnemidophorus ocellifer (2n = 50, all biarmed), are herein described and compared on the basis of conventional and silver staining, and CBG and RBG banding patterns. Meiotic data are also included. Karyotypes of K. paulensis, K. vanzoi, and C. ocellifer are reported here for the first time. Inter-generic variability in Ag-NORs location was detected with NORs occurring at the end of long arm of pair 1 in K. calcarata, K. paulensis, and K. vanzoi; pair 5 in C. ocellifer and pair 7 in A. ameiva. The location of NORs, along with the karyological differences between A. ameiva and the Central American species (A. auberi), corroboretes the molecular-based hypothesis that the genus Ameiva is paraphyletic. Inter-populational heteromorphism in Ag-NORs size was detected between populations of C. ocellifer. RBG and CBG banding data demonstrated that the biarmed condition of the C. ocellifer chromosomes is due to multiple pericentric inversion events instead of addition of constitutive heterochromatin. Differential-staining techniques used here revealed valuable information about Teiinae karyotypic diversity and made it possible to compare these species, contributing to both the better comprehension of their chromosomal evolution and issues on taxa systematics.

First Measurements of High Frequency Cross-Spectra from a Pair of Large Michelson Interferometers

Energy Technology Data Exchange (ETDEWEB)

Chou, Aaron S.; Gustafson, Richard; Hogan, Craig; Kamai, Brittany; Kwon, Ohkyung; Lanza, Robert; McCuller, Lee; Meyer, Stephan S.; Richardson, Jonathan; Stoughton, Chris; Tomlin, Raymond; Waldman, Samuel; Weiss, Rainer

2016-09-01

Measurements are reported of high frequency cross-spectra of signals from the Fermilab Holometer, a pair of co-located 39 m, high power Michelson interferometers. The instrument obtains differential position sensitivity to cross-correlated signals far exceeding any previous measurement in a broad frequency band extending to the 3.8 MHz inverse light crossing time of the apparatus. A model of universal exotic spatial shear correlations that matches the Planck scale holographic information bound of space-time position states is excluded to 4.6{\\sigma} significance.

Radiating Elements for Shared Aperture Tx/Rx Phased Arrays at K/Ka Band

KAUST Repository

Sandhu, Ali Imran; Arnieri, E.; Amendola, Giandomenico; Boccia, L.; Meniconi, Erika; Ziegler, Volker

2016-01-01

A dual band, Tx/Rx, self-diplexing phased array is presented. The antenna has been designed to cover Tx/Rx satellite communications at K/Ka band with a frequency ratio 1.5:1. To obtain dual band operations with a single radiating surface, a novel dual band radiator is adopted and placed in a configuration in which dual band and single band elements are interleaved. The proposed configuration reduces the number of radiating elements required by other solutions while avoiding the insurgence of grating lobes. The tightly packed arrangement of the elements poses many integration issues, which are solved with a novel integration technique. The array elements are optimized to scan the beam in excess of ° in both bands. A subarray with 49 Rx elements and 105 Tx elements was built and measured confirming the results obtained in simulations.

Radiating Elements for Shared Aperture Tx/Rx Phased Arrays at K/Ka Band

KAUST Repository

Sandhu, Ali Imran

2016-04-11

A dual band, Tx/Rx, self-diplexing phased array is presented. The antenna has been designed to cover Tx/Rx satellite communications at K/Ka band with a frequency ratio 1.5:1. To obtain dual band operations with a single radiating surface, a novel dual band radiator is adopted and placed in a configuration in which dual band and single band elements are interleaved. The proposed configuration reduces the number of radiating elements required by other solutions while avoiding the insurgence of grating lobes. The tightly packed arrangement of the elements poses many integration issues, which are solved with a novel integration technique. The array elements are optimized to scan the beam in excess of ° in both bands. A subarray with 49 Rx elements and 105 Tx elements was built and measured confirming the results obtained in simulations.

Two band superconductivity for MgB2: Tc and isotope exponent α as a function of the carrier number n and the role of the center of the band

International Nuclear Information System (INIS)

Rodriguez-Nunez, J.J.; Schmidt, A.A.; Bianconi, A.; Perali, A.

2005-08-01

We study a two band superconducting, assuming that we have two tight binding bands, ε 2 (k-vector) = ε 2 (0) - t 2 [cos(k x ) + cos(k y ) + s 2 cos(k z )] - μ and ε 3 (k-vector) ε 3 (0) - t 3 [cos(k x ) + cos(k y )+s 3 cos(k z )] - μ. We solve the two gap equations at T = T c and calculate T c x n and μ x n for various values of pairing interaction, V, and Debye frequency, ω D . Also, from an expression developed in a previous paper by two of the present authors, we calculate α x n, where n is the number of carriers per site per band and α is the isotope exponent. We take only interband scattering, V, as a first approach. We find that in order to have superconductivity (T c ≠ 0), large values of V are necessary. Also, for V/ω D > 1, we obtain α > 1.00 and for V/ω D >1.00, the isotope exponent becomes less than 1. (author)

Multi-quasiparticle high-K isomeric states in deformed nuclei

Directory of Open Access Journals (Sweden)

Xu F. R.

2016-01-01

Full Text Available In the past years, we have made many theoretical investigations on multi-quasiparticle high-K isomeric states. A deformation-pairing-configuration self-consistent calculation has been developed by calculating a configuration-constrained multi-quasiparticle potential energy surface (PES. The specific single-particle orbits that define the high-K configuration are identified and tracked (adiabatically blocked by calculating the average Nilsson numbers. The deformed Woods-Saxon potential was taken to give single-particle orbits. The configuration-constrained PES takes into account the shape polarization effect. Such calculations give good results on excitation energies, deformations and other structure information about multi-quasiparticle high-K isomeric states. Many different mass regions have been investigated.

Optical study of the band structure of wurtzite GaP nanowires

OpenAIRE

Assali, S.; Greil, J.; Zardo, I.; Belabbes, A.; de Moor, M.W.A.; Kölling, S.; Koenraad, P.M.; Bechstedt, F.; Bakkers, E.P.A.M.; Haverkort, J.E.M.

2016-01-01

We investigated the optical properties of wurtzite (WZ) GaP nanowires by performing photoluminescence (PL) and time-resolved PL measurements in the temperature range from 4 K to 300 K, together with atom probe tomography to identify residual impurities in the nanowires. At low temperature, the WZ GaP luminescence shows donor-acceptor pair emission at 2.115 eV and 2.088 eV, and Burstein-Moss band-filling continuum between 2.180 and 2.253 eV, resulting in a direct band gap above 2.170 eV. Sharp...

Facts about Broken Bones

Science.gov (United States)

... Safe Videos for Educators Search English Español Broken Bones KidsHealth / For Kids / Broken Bones What's in this ... sticking through the skin . What Happens When a Bone Breaks? It hurts to break a bone! It's ...

Successive reactivation of older structures under variable heat flow conditions evidenced by K-Ar fault gouge dating in Sierra de Ambato, northern Argentine broken foreland

Science.gov (United States)

Nóbile, Julieta C.; Collo, Gilda; Dávila, Federico M.; Martina, Federico; Wemmer, Klaus

2015-12-01

The Argentine broken foreland has been the subject of continuous research to determine the uplift and exhumation history of the region. High-elevation mountains are the result of N-S reverse faults that disrupted a W-E Miocene Andean foreland basin. In the Sierra de Ambato (northern Argentine broken foreland) the reverse faults offset Neogene sedimentary rocks (Aconquija Fm., ˜9 Ma) and affect the basement comprising Paleozoic metamorphic rocks that have been dated at ˜477-470 Ma. In order to establish a chronology of these faults affecting the previous continuous basin we date the formation age of clay minerals associated with fault gouge using the K-Ar dating technique. Clay mineral formation is a fundamental process in the evolution of faults under the brittle regime (history with a minimum age of ˜360 Ma and a last clay minerals forming event at ˜220 Ma. Moreover, given the progression of apparent ages decreasing from coarse to fine size fractions (˜360-311 Ma for 2-1 μm grain size fraction, ˜326-286 Ma for 1-0.2 μm and ˜291-219 Ma of <0.2 μm), we modeled discrete deformation events at ˜417 Ma (ending of the Famatinian cycle), ˜317-326 Ma (end of Gondwanic orogeny), and ˜194-279 Ma (Early Permian - Jurassic deformation). According to our data, the Neogene reactivation would not have affected the K-Ar system neither generated a significant clay minerals crystallization in the fault gouge, although an exhumation of more than 2 Km is recorded in this period from stratigraphic data.

Phenomenology of muon number violation in spontaneously broken gauge theories

International Nuclear Information System (INIS)

Shanker, O.U.

1980-01-01

The phenomenology of muon number violation in gauge theories of weak and electromagnetic interactions is studied. In the first chapter a brief introduction to the concept of muon number and to spontaneously broken gauge theories is given. A review of the phenomenology and experimental situation regarding different muon number violating processes is made in the second chapter. A detailed phenomenological study of the μe conversion process μ - + (A,Z) → e - + (A,Z) is given in the third chapter. In the fourth chapter some specific gauge theories incorporating spontaneously broken horizontal gauge symmetries between different fermion generations are discussed with special reference to muon number violation in the theories. The μe conversion process seems to be a good process to search for muon number violation if it occurs. The K/sub L/-K/sub S/ mass difference is likely to constrain muon number violating rates to lie far below present experimental limits unless strangeness changing neutral currents changing strangeness by two units are suppressed

Dual-band high-efficiency polarization converter using an anisotropic metasurface

Science.gov (United States)

Lin, Baoqin; Wang, Buhong; Meng, Wen; Da, Xinyu; Li, Wei; Fang, Yingwu; Zhu, Zihang

2016-05-01

In this work, a dual-band and high-efficiency reflective cross-polarization converter based on an anisotropic metasurface for linearly polarized electromagnetic waves is proposed. Its unit cell is composed of an elliptical disk-ring mounted on grounded dielectric substrate, which is an anisotropic structure with a pair of mutually perpendicular symmetric axes u and v along ± 45 ° directions with respect to y-axis direction. Both the simulation and measured results show that the polarization converter can convert x- or y-polarized incident wave to its cross polarized wave in the two frequency bands (6.99-9.18 GHz, 11.66-20.40 GHz) with the conversion efficiency higher than 90%; moreover, the higher frequency band is an ultra-wide one with a relative bandwidth of 54.5% for multiple plasmon resonances. In addition, we present a detailed analysis for the polarization conversion of the polarization converter, and derive a formula to calculate the cross- and co-polarization reflections at y-polarized incidence according to the phase differences between the two reflected coefficients at u-polarized and v-polarized incidences. The simulated, calculated, and measured results are all in agreement with the entire frequency regions.

Nonrestoration of spontaneously broken P, CP and PQ at high temperature

International Nuclear Information System (INIS)

Dvali G.; Melfo, A.; Senjanovic, G.

1996-01-01

The possibility of P and CP violation at high temperature in models where these symmetries are spontaneously broken is investigated. It is found that in minimal models that include singlet fields, high T nonrestoration is possible for a wide range of parameters of the theory, in particular in models of CP violation with a CP-odd Higgs field. The same holds true for the invisible axion version of the Peccei-Quinn mechanism. This can provide both a way out for the domain wall problem in these theories and the CP violation required for baryogenesis. In the case of spontaneous P violation it turns out that high T nonrestoration required going beyond the minimal model. The results are shown to hold true when next-to-leading order effects are considered. (author). 33 refs, 3 figs

String Threshold corrections in models with spondaneously broken supersymmetry

CERN Document Server

Kiritsis, Elias B; Petropoulos, P M; Rizos, J

1999-01-01

We analyse a class of four-dimensional heterotic ground states with N=2 space-time supersymmetry. From the ten-dimensional perspective, such models can be viewed as compactifications on a six-dimensional manifold with SU(2) holonomy, which is locally but not globally K3 x T^2. The maximal N=4 supersymmetry is spontaneously broken to N=2. The masses of the two massive gravitinos depend on the (T,U) moduli of T^2. We evaluate the one-loop threshold corrections of gauge and R^2 couplings and we show that they fall in several universality classes, in contrast to what happens in usual K3 x T^2 compactifications, where the N=4 supersymmetry is explicitly broken to N=2, and where a single universality class appears. These universality properties follow from the structure of the elliptic genus. The behaviour of the threshold corrections as functions of the moduli is analysed in detail: it is singular across several rational lines of the T^2 moduli because of the appearance of extra massless states, and suffers only f...

Experimental study of broadband unidirectional splitting in photonic crystal gratings with broken structural symmetry

Science.gov (United States)

Colak, Evrim; Serebryannikov, Andriy E.; Ozgur Cakmak, A.; Ozbay, Ekmel

2013-04-01

It is experimentally demonstrated that the combination of diode and splitter functions can be realized in one broadband reciprocal device. The suggested performance is based on the dielectric photonic crystal grating whose structural symmetry is broken owing to non-deep corrugations placed at one of the two interfaces. The study has been performed at a normally incident beam-type illumination obtained from a microwave horn antenna. The two unidirectionally transmitted, deflected beams can show large magnitude and high contrast, while the angular distance between their maxima is 90° and larger. The dual-band unidirectional splitting is possible when using TM and TE polarizations.

On van der Waals-like forces in spontaneously broken supersymmetries

International Nuclear Information System (INIS)

Radescu, E.E.

1982-12-01

In spontaneously broken rigid supersymmetry, Goldstone fermion pair exchange should lead to a universal interaction between massive bodies uniquely fixed by the existing low energy theorem. The resulting van der Waals-like potential is shown to be V(r)=Mmπ -3 F -4 r -7 +O(r -8 ), where M,m are the masses of the interacting bodies while √F is the scale of the breaking. The change in the situation when the supersymmetry is promoted to a local one is briefly discussed. (author)

Cusp Guns for Helical-Waveguide Gyro-TWTs of a High-Gain High-Power W-Band Amplifier Cascade

Science.gov (United States)

Manuilov, V. N.; Samsonov, S. V.; Mishakin, S. V.; Klimov, A. V.; Leshcheva, K. A.

2018-02-01

The evaluation, design, and simulations of two different electron guns generating the beams for W-band second cyclotron harmonic gyro-TWTs forming a high-gain powerful amplifier cascade are presented. The optimum configurations of the systems creating nearly axis-encircling electron beams having velocity pitch-factor up to 1.5, voltage/current of 40 kV/0.5 A, and 100 kV/13 A with acceptable velocity spreads have been found and are presented.

Pairing mechanism in oxide superconductors

International Nuclear Information System (INIS)

Hirsch, J.E.

1988-01-01

A useful way to learn about the pairing mechanism that is responsible for high T c superconductivity is to study properties of model Hamiltonians on small systems. The goal is to find the simplest model that can describe the essential physics of high T c superconductivity. The authors have used Monte Carlo simulation and exact diagonalization techniques to study properties of systems of up to 64 sites. Their results show that spin fluctuations and other spin related mechanisms induced by a Hubbard on-site repulsion U are not likely to give rise to pairing, neither in one nor in multiple band models. In contrast, charge fluctuations in a model with both strong U and V (repulsion between Cu and O) are shown to give rise to pairing and it is suggested that this model provides a plausible mechanism for high T c superconductivity

First tests of twisted-pair HTS 1 kA range cables for use in superconducting links

CERN Document Server

Ballarino, A; Hurte, J; Sitko, M; Willering, G

2011-01-01

The requirement at CERN for 1 kA range High Temperature Superconducting (HTS) cables optimized for long electrical transfer has led to the design and assembly of a novel type of cable that can be made from pre-reacted MgB2, Bi-2223 or YBCO tapes. The cable consists of an assembly of twisted pairs, each of which is made from three superconducting tapes with the required copper stabilizer. The twisted pair cable is designed to transfer a DC current of ± 600 A in helium gas environment. The paper reports on the results of the electrical tests performed on twisted-pair cables of identical structure and made from commercially available MgB2, Bi-2223 and YBCO tapes. The twist pitch of the cables is adapted to match the mechanical properties of the different superconductors. Critical current tests were performed at both liquid helium and liquid nitrogen temperature. The electrical performance of several cables made from different conductors is reported and compared.

Two-band superconductor magnesium diboride

International Nuclear Information System (INIS)

Xi, X X

2008-01-01

This review focuses on the most important features of the 40 K superconductor MgB 2 -the weakly interacting multiple bands (the σ and π bands) and the distinct multiple superconducting energy gaps (the σ and π gaps). Even though the pairing mechanism of superconductor MgB 2 is the conventional electron-phonon coupling, the prominent influence of the two bands and two gaps on its properties sets it apart from other superconductors. It leads to markedly different behaviors in upper critical field, vortex structure, magnetoresistance and many other superconducting and normal-state properties in MgB 2 from single-band superconductors. Further, it gives rise to new physics that does not exist in single-band superconductors, such as the internal Josephson effects between the two order parameters. These unique phenomena depend sensitively on scattering inside and between the two bands, and the intraband and interband scattering can be modified by chemical substitution and irradiation. MgB 2 has brought unprecedented attention to two-band superconductivity, which has been found to exist in other old and new superconductors. The legacy of MgB 2 will be long lasting because of this, as well as the lessons it teaches in terms of the search for new phonon-mediated higher T c superconductors

New high spin states and band termination in 83Y and 84Zr

International Nuclear Information System (INIS)

Johnson, T.D.; Aprahamian, A.; Lister, C.J.; Blumenthal, D.J.; Crowell, B.; Chowdhury, P.; Fallon, P.; Machiavelli, A.O.

1997-01-01

The gamma decay of high spin yrast states in 83 Y up to I π =59/2 + and 53/2 - have been observed using the reaction 58 Ni( 29 Si,3p) at 110 MeV and the Gammasphere Early Implementation Array. The level scheme has been substantially extended due to the observations of several new transitions in all of the bands. A sequence of transitions feeding into the positive parity yrast band above I π =47/2 + seems to be consistent with a noncollective oblate structure expected at these high spins. A similar cascade is found in the data for 84 Zr. A new forking of the favored negative parity band is found which may be due to neutron alignment polarizing the core to a different shape. This suggests that the open-quotes isomeric close-quote close-quote band in 83 Y, for which one more connecting transition was found, is of a similar nature to other high-K bands found in this region. Lifetime measurements in the unfavored negative parity band are consistent with cranking calculations which predict a nearly oblate shape with a deformation parameter β 2 ∼0.2. A qualitative analysis of line shapes at very high spins suggests the persistence of collectivity in the yrast sequence to the highest excitations seen. copyright 1997 The American Physical Society

K-Band Phased Array Developed for Low- Earth-Orbit Satellite Communications

Science.gov (United States)

Anzic, Godfrey

1999-01-01

Future rapid deployment of low- and medium-Earth-orbit satellite constellations that will offer various narrow- to wide-band wireless communications services will require phased-array antennas that feature wide-angle and superagile electronic steering of one or more antenna beams. Antennas, which employ monolithic microwave integrated circuits (MMIC), are perfectly suited for this application. Under a cooperative agreement, an MMIC-based, K-band phased-array antenna is being developed with 50/50 cost sharing by the NASA Lewis Research Center and Raytheon Systems Company. The transmitting array, which will operate at 19 gigahertz (GHz), is a state-of-the-art design that features dual, independent, electronically steerable beam operation ( 42 ), a stand-alone thermal management, and a high-density tile architecture. This array can transmit 622 megabits per second (Mbps) in each beam from Earth orbit to small Earth terminals. The weight of the total array package is expected to be less than 8 lb. The tile integration technology (flip chip MMIC tile) chosen for this project represents a major advancement in phased-array engineering and holds much promise for reducing manufacturing costs.

Induced absorption spectra of the infrared fundamental band of molecular deuterium at 77 K: S1( J)+S0( J) transitions

International Nuclear Information System (INIS)

Gillard, P.G.; Prasad, R.D.G.; Reddy, S.P.

1984-01-01

The collision-induced spectra of the fundamental band of normal D 2 in the high frequency region 3200--3700 cm -1 were recorded for gas densities in the range 80--140 amagat at 77 K with a 2 m absorption cell. The contribution to the intensity of the band in this region comes from the high frequency wings of quadrupolar transitions S 1 ( J) and Q 1 ( J)+S 0 ( J) with J = 0 and 1, and from the group of transitions S 1 (2) and Q 1 ( J)+S 0 (2) with J = 0, 1, and 2 as well as from the relatively weaker double rotational transitions of the type S 1 ( J)+S 0 ( J); the latter transitions arise from the intermolecular interaction between the anisotropic component of the polarizability of one of the colliding pairs of molecules and the quadrupole field of the other. The experimental profiles were analyzed by assuming appropriate line shape functions and using the theoretical matrix elements of the quadrupole moment, isotropic polarizability, and anisotropy of polarizability of the D 2 molecule. From this analysis the characteristic half-width parameters delta/sub q/2 and delta/sub q/4 of the quadrupolar transitions and the binary and ternary absorption coefficients of the S 1 ( J)+S 0 ( J) transitions have been obtained. The experimental value of the binary absorption coefficient of S 1 (0)+S 0 (0) is (2.2 +- 0.1) x 10 -9 cm -1 amagat -2 and the corresponding theoretical value is 1.53 x 10 -9 cm -1 amagat -2

Torsion-rotation structure and quasi-symmetric-rotor behaviour for the CH3SH asymmetric CH3-bending and C-H stretching bands of E parentage

Science.gov (United States)

Lees, R. M.; Xu, Li-Hong; Guislain, B. G.; Reid, E. M.; Twagirayezu, S.; Perry, D. S.; Dawadi, M. B.; Thapaliya, B. P.; Billinghurst, B. E.

2018-01-01

High-resolution Fourier transform spectra of the asymmetric methyl-bending and methyl-stretching bands of CH3SH have been recorded employing synchrotron radiation at the FIR beamline of the Canadian Light Source. Analysis of the torsion-rotation structure and relative intensities has revealed the novel feature that for both bend and stretch the in-plane and out-of-plane modes behave much like a Coriolis-coupled l-doublet pair originating from degenerate E modes of a symmetric top. As the axial angular momentum K increases, the energies of the coupled "l = ±1" modes diverge linearly, with effective Coriolis ζ constants typical for symmetric tops. For the methyl-stretching states, separated at K = 0 by only about 1 cm-1, the assigned sub-bands follow a symmetric top Δ(K - l) = 0 selection rule, with only ΔK = -1 transitions observed to the upper l = -1 in-plane A‧ component and only ΔK = +1 transitions to the lower l = +1 out-of-plane A″ component. The K = 0 separation of the CH3-bending states is larger at 9.1 cm-1 with the l-ordering reversed. Here, both ΔK = +1 and ΔK = -1 transitions are seen for each l-component but with a large difference in relative intensity. Term values for the excited state levels have been fitted to J(J + 1) power-series expansions to obtain substate origins. These have then been fitted to a Fourier model to characterize the torsion-K-rotation energy patterns. For both pairs of vibrational states, the torsional energies display the customary oscillatory behaviour as a function of K and have inverted torsional splittings relative to the ground state. The spectra show numerous perturbations, indicating local resonances with the underlying bath of high torsional levels and vibrational combination and overtone states. The overall structure of the two pairs of bands represents a new regime in which the vibrational energy separations, torsional splittings and shifts due to molecular asymmetry are all of the same order, creating a

A microwave window for K band electromagnetic systems

DEFF Research Database (Denmark)

Rybalko, Oleksandr

2017-01-01

This article proposes a solution for microwave window at K band. Properties of the window such as performance (transparency) at microwave frequencies, dimensions, and mounting place are discussed. The dimensions of the window were optimized in a full-wave simulator. To verify the design...... and simulation results the prototype of the window is realized by implementing into transition section and tested experimentally. The microwave window provides low return loss |S11| below −30 dB, low insertion loss |S21| below −0.5 dB and can be used for electromagnetic systems where vacuum sealing is required...

First measurement of the decoupling parameter for the K = 1 band of {sup 156}Gd

Energy Technology Data Exchange (ETDEWEB)

Beck, Tobias; Beller, Jacob; Gayer, Udo; Pietralla, Norbert; Ries, Philipp; Ries, Christopher; Werner, Volker; Zweidinger, Markus [IKP, TU Darmstadt (Germany); Derya, Vera [IKP, Universitaet zu Koeln (Germany); Isaak, Johann; Loeher, Bastian [EMMI, GSI, Darmstadt (Germany); FIAS, Frankfurt (Germany); Scheck, Marcus [IKP, TU Darmstadt (Germany); School of Engineering, UWS Paisley (United Kingdom); SUPA, Glasgow (United Kingdom); Tornow, Werner; Weller, Henry R. [Duke University, Durham (United States)

2016-07-01

In a deformed nucleus the nuclear states are combinations of an intrinsic motion and a rotational motion of the core. In this scenario the Coriolis force changes the projection of the angular momentum on the symmetry axis and admixes different K values. The effects of the Coriolis interactions have been observed experimentally for K = 1/2 bands. The recent observation of the first excited rotational state of the isovector low-lying J{sup π}{sub K} = 1{sup +}{sub 1} scissors mode in a (γ,γ{sup '}) experiment inaugurates a case to study the Coriolis decoupling for K = 1 bands. In the talk, the theoretical description provided by Bohr and Mottelson is presented, and their adaption to the particular case is explained alongside the ongoing analysis and open questions.

Simple New Screw Insertion Technique without Extraction for Broken Pedicle Screws.

Science.gov (United States)

Kil, Jin-Sang; Park, Jong-Tae

2018-05-01

Spinal transpedicular screw fixation is widely performed. Broken pedicle screw rates range from 3%-7.1%. Several techniques have been described for extraction of broken pedicle screws. However, most of these techniques require special instruments. We describe a simple, modified technique for management of broken pedicle screws without extraction. No special instruments or drilling in an adjacent pedicle are required. We used a high-speed air drill with a round burr. With C-arm fluoroscopy guidance, the distal fragment of a broken pedicle screw was palpated using free-hand technique through the screw entry hole. A high-speed air drill with a round burr (not a diamond burr) was inserted through the hole. Drilling began slowly and continued until enough space was obtained for new screw insertion. Using this space, we performed new pedicle screw fixation medially alongside the distal fragment of the broken pedicle screw. We performed the insertion with a previously used entry hole and pathway in the pedicle. The same size pedicle screw was used. Three patients were treated with this modified technique. New screw insertion was successful in all cases after partial drilling of the distal broken pedicle screw fragment. There were no complications, such as screw loosening, dural tears, or root injury. We describe a simple, modified technique for management of broken pedicle screws without extraction. This technique is recommended in patients who require insertion of a new screw. Copyright © 2017. Published by Elsevier Inc.

Test Results From a Pair of 1-kWe Dual-Opposed Free-Piston Stirling Power Convertors Integrated With a Pumped NaK Loop

Science.gov (United States)

Geng, Steven M.; Briggs, Maxwell H.; Penswick, L. Barry; Pearson, J. Boise; Godfroy, Thomas J.

2011-01-01

As a step towards development of Stirling power conversion for potential use in Fission Surface Power (FSP) systems, a pair of commercially available 1-kW-class free-piston Stirling convertors were modified to operate with a NaK (sodium (Na) and potassium (K)) liquid metal pumped loop for thermal energy input. This was the first-ever attempt at powering a free-piston Stirling engine with a pumped liquid metal heat source and is a major FSP project milestone towards demonstrating technical feasibility. The convertors were successfully tested at the Marshall Space Flight Center (MSFC) from June 6 through July 14, 2009. The convertors were operated for a total test time of 66 hr and 16 min. The tests included (a) performance mapping the convertors over various hot- and cold-end temperatures, piston amplitudes, and NaK flow rates and (b) transient test conditions to simulate various startup (i.e., low-, medium-, and high-temperature startups) and fault scenarios (i.e., loss of heat source, loss of NaK pump, convertor stall, etc.). This report documents the results of this testing

Effect of g-boson on spectra of high-spin states in 100Pd nucleus

International Nuclear Information System (INIS)

Zhao Xingzhi; Ni Shaoyong; Tong Hong; Shi Zhuyi; Second Northwest Inst. for Minority, Yinchuan; Shi Zhuya

2007-01-01

By using a microscopic sdgIBM-2 approach which is the accomplishment of the phenomenological sdgIBM theory and the experimental single-particle energies, the levels of the more complex ground-state band and the high-angular momentum states of y-band on 100 Pd nucleus are successfully reproduced. The ground-state band and γ-band are described well up to J π =16 + and E x =7.00 MeV, and that is larger than that J π 6 + -8 + , E x =2.00 MeV can be successfully reproduced in IBM theory. It has been proved that its yrast states up to the 16 + state are ground states, there may not exist any broken pair quasi-particle state by boson in yrast states. Theoretical analysis and numerical calculation show that to describe successfully spectra on 100 Pd nucleus under the boson approach in IBM theory, it is impossible that the g-boson has been not considered in one. According to the microscopic sdgIBM-2 approach, the 14 1 + state is understood as a result that a neutron g-boson transites into a neutron d-boson and a pair of photos is radiated at same time, and the 14 2 + state is the decoupling state of the 16 1 + state, while the 14 3 + state is the actual ground state. (authors)

Fractures (Broken Bones): First Aid

Science.gov (United States)

First aid Fractures (broken bones) Fractures (broken bones): First aid By Mayo Clinic Staff A fracture is a ... 10, 2018 Original article: http://www.mayoclinic.org/first-aid/first-aid-fractures/basics/ART-20056641 . Mayo Clinic ...

Broken color symmetry and weak currents

International Nuclear Information System (INIS)

Stech, B.

1976-01-01

Broken colour symmetry predicts a very rich spectrum of new particles. If broken colour is relevant at all, charged psi-particles should be found in particular at the 4 GeV region. For the weak hadronic currents no completely satisfactory suggestion exists. Broken colour symmetry describes qualitatively several of the new effects observed recently. (BJ) [de

Experimental Studies of W-Band Accelerator Structures at High Field

Energy Technology Data Exchange (ETDEWEB)

Hill, Marc E

2001-02-09

A high-gradient electron accelerator is desired for high-energy physics research, where frequency scalings of breakdown and trapping of itinerant beamline particles dictates operation of the accelerator at short wavelengths. The first results of design and test of a high-gradient mm-wave linac with an operating frequency at 91.392 GHz (W-band) are presented. A novel approach to particle acceleration is presented employing a planar, dielectric lined waveguide used for particle acceleration. The traveling wave fields in the planar dielectric accelerator (PDA) are analyzed for an idealized structure, along with a circuit equivalent model used for understanding the structure as a microwave circuit. Along with the W-band accelerator structures, other components designed and tested are high power rf windows, high power attenuators, and a high power squeeze-type phase shifter. The design of the accelerator and its components where eased with the aide of numerical simulations using a finite-difference electromagnetic field solver. Manufacturing considerations of the small, delicate mm-wave components and the steps taken to reach a robust fabrication process are detailed. These devices were characterized under low power using a two-port vector network analyzer to verify tune and match, including measurements of the structures' fields using a bead-pull. The measurements are compared with theory throughout. Addition studies of the W-band structures were performed under high power utilizing a 11.424 GHz electron linac as a current source. Test results include W-band power levels of 200 kW, corresponding to fields in the PDA of over 20 MV/m, a higher gradient than any collider. Planar accelerator devices naturally have an rf quadrupole component of the accelerating field. Presented for the first time are the measurements of this effect.

Multiple superdeformed bands in sup 194 Hg and their dynamical moments of inertia

Energy Technology Data Exchange (ETDEWEB)

Riley, M.A.; Cullen, D.M.; Alderson, A.; Ali, I.; Fallon, P.; Forsyth, P.D.; Hanna, F.; Mullins, S.M.; Roberts, J.W.; Sharpey-Schafer, J.F.; Twin, P.J. (Liverpool Univ. (UK). Oliver Lodge Lab.); Poynter, R.; Wadsworth, R. (York Univ. (UK). Dept. of Physics); Bentley, M.A.; Bruce, A.M.; Simpson, J. (Science and Engineering Research Council, Daresbury (UK). Daresbury Lab.); Sletten, G. (Niels Bohr Inst., Roskilde (Denmark). Tandem Accelerator Lab.); Nazarewicz, W. (Liverpool Univ. (UK). Oliver Lodge Lab. Politechnika Warszawska (Poland). Inst. Fizyki); Bengtsson, T. (Lund Inst. of Tech. (Sweden). Dept. of Mathematical Physics); Wyss, R. (Manne Siegbahn Inst. of Physics, Stockholm (Sweden))

1990-05-28

Three superdeformed bands have been observed in {sup 194}Hg. The dynamical moment of inertia J{sup (2)} of all three bands is observed to increase by 30-40% over the frequency range {Dirac h}{omega}=0.1-0.4 MeV. This phenomena can be understood in terms of the gradual alignment of pairs of high-j intruder orbitals within the framework of the cranked Woods-Saxon and Nilsson models including pairing. The calculations together with the observed J{sup (2)} behaviour of the three bands indicate that pairing correlations in the superdeformed minimum are rather weak. (orig.).

Cooper-pair size and binding energy for unconventional superconducting systems

Science.gov (United States)

Dinóla Neto, F.; Neto, Minos A.; Salmon, Octavio D. Rodriguez

2018-06-01

The main proposal of this paper is to analyze the size of the Cooper pairs composed by unbalanced mass fermions from different electronic bands along the BCS-BEC crossover and study the binding energy of the pairs. We are considering an interaction between fermions with different masses leading to an inter-band pairing. In addiction to the attractive interaction we have an hybridization term to couple both bands, which in general acts unfavorable for the pairing between the electrons. We get first order phase transitions as the hybridization breaks the Cooper pairs for the s-wave symmetry of the gap amplitude. The results show the dependence of the Cooper-pair size as a function of the hybridization for T = 0 . We also propose the structure of the binding energy of the inter-band system as a function of the two-bands quasi-particle energies.

Anharmonic effective pair potentials of gold under high pressure and high temperature

CERN Document Server

Okube, M; Ohtaka, O; Fukui, H; Katayama, Y; Utsumi, W

2002-01-01

In order to examine the effect of pressure on the anharmonicity of Au, extended x-ray absorption fine-structure spectra near the Au L sub 3 edge were measured in the temperature range from 300 to 1100 K under pressures up to 14 GPa using large-volume high-pressure devices and synchrotron radiation. The anharmonic effective pair potentials of Au, V (u) = au sup 2 + bu sup 3 , at 0.1 MPa, 6 and 14 GPa have been calculated. The pressure dependence of the thermal expansion coefficients has also been evaluated. The reliability of the anharmonic correction proposed on the basis of the Anderson scale has been discussed.

Performance of high-temperature superconducting band-pass filters with high selectivity for base transceiver applications of digital cellular communication systems

Science.gov (United States)

Kwak, J. S.; Lee, J. H.; Kim, C. O.; Hong, J. P.; Han, S. K.; Char, K.

2002-07-01

Highly selective high-temperature superconducting band-pass filters based on spiral meander line structures have been developed for base transceiver station applications of digital cellular communication systems. The filter comprised 12-pole microstrip line resonators with a circuit size of 0.5 × 17 × 41 mm3. The filter was designed to have a bandwidth of 25 MHz at a centre frequency of 834 MHz. Particularly, the physical size of each resonator was chosen not only to reduce far-field radiation, but also to have reasonable tunability in the filter. Device characteristics exhibited a low insertion loss of 0.4 dB with a 0.2 dB ripple and a return loss better than 10 dB in the pass-band at 65 K. The out-of-band signals were attenuated better than 60 dB at about 3.5 MHz from the lower band edge, and 3.8 MHz from the higher band edge.

Performance of high-temperature superconducting band-pass filters with high selectivity for base transceiver applications of digital cellular communication systems

Energy Technology Data Exchange (ETDEWEB)

Kwak, J.S.; Lee, J.H.; Kim, C.O.; Hong, J.P. [Department of Physics, Hanyang University, Seoul (Korea, Republic of); Han, S.K.; Char, K. [RFtron Inc., Seoul (Korea, Republic of)

2002-07-01

Highly selective high-temperature superconducting band-pass filters based on spiral meander line structures have been developed for base transceiver station applications of digital cellular communication systems. The filter comprised 12-pole microstrip line resonators with a circuit size of 0.5x17x41 mm{sup 3}. The filter was designed to have a bandwidth of 25 MHz at a centre frequency of 834 MHz. Particularly, the physical size of each resonator was chosen not only to reduce far-field radiation, but also to have reasonable tunability in the filter. Device characteristics exhibited a low insertion loss of 0.4 dB with a 0.2 dB ripple and a return loss better than 10 dB in the pass-band at 65 K. The out-of-band signals were attenuated better than 60 dB at about 3.5 MHz from the lower band edge, and 3.8 MHz from the higher band edge. (author)

Performance of high-temperature superconducting band-pass filters with high selectivity for base transceiver applications of digital cellular communication systems

International Nuclear Information System (INIS)

Kwak, J.S.; Lee, J.H.; Kim, C.O.; Hong, J.P.; Han, S.K.; Char, K.

2002-01-01

Highly selective high-temperature superconducting band-pass filters based on spiral meander line structures have been developed for base transceiver station applications of digital cellular communication systems. The filter comprised 12-pole microstrip line resonators with a circuit size of 0.5x17x41 mm 3 . The filter was designed to have a bandwidth of 25 MHz at a centre frequency of 834 MHz. Particularly, the physical size of each resonator was chosen not only to reduce far-field radiation, but also to have reasonable tunability in the filter. Device characteristics exhibited a low insertion loss of 0.4 dB with a 0.2 dB ripple and a return loss better than 10 dB in the pass-band at 65 K. The out-of-band signals were attenuated better than 60 dB at about 3.5 MHz from the lower band edge, and 3.8 MHz from the higher band edge. (author)

An S-band high gain relativistic klystron amplifier with high phase stability

Energy Technology Data Exchange (ETDEWEB)

Wu, Y. [Institute of Applied Electronics, China Academy of Engineering Physics, Mianyang 621900 (China); Science and Technology on High Power Microwave Laboratory, Mianyang 621900 (China); Li, Z. H.; Xu, Z.; Ma, Q. S. [Institute of Applied Electronics, China Academy of Engineering Physics, Mianyang 621900 (China); Xie, H. Q. [College of Science, Southwestern University of Science and Technology, Mianyang 621010 (China)

2014-11-15

For the purpose of coherent high power microwave combining, an S-band high gain relativistic klystron amplifier with high phase stability is presented and studied. By the aid of 3D particle-in-cell code and circuit simulation software, the mechanism of parasitic oscillation in the device is investigated. And the RF lossy material is adopted in the simulation and experiment to suppress the oscillation. The experimental results show that with an input RF power of 10 kW, a microwave pulse with power of 1.8 GW is generated with a gain of 52.6 dB. And the relative phase difference fluctuation between output microwave and input RF signal is less than ±10° in 90 ns.

K-wire and tension band wire fixation in treating sternoclavicular joint dislocation.

Science.gov (United States)

Chen, Qing-yu; Cheng, Shao-wen; Wang, Wei; Lin, Zhong-qin; Zhang, Wei; Kou, Dong-quan; Shen, Yue; Ying, Xiao-zhou; Cheng, Xiao-jie; Lv, Chuan-zhu; Peng, Lei

2011-02-01

To evaluate the feasibility and therapeutic effect of treating sternoclavicular joint dislocation by K-wire and tension band wire fixation, and to improve the safety and stability of this technique. This study consisted of 9 cases, 6 males and 3 females with the mean age of 25 years (range, 9-62 years). The causes were traffic accident in 7 cases, falling in 1 case and fight in 1 case. The duration from injury to operation was 2 hours to 7 days. There were 5 left dislocations and 4 right dislocations; 8 anterior dislocations and 1 posterior dislocation, including one combined with left scapular fracture and one with left olecranon fracture. Open reduction and internal fixation using K-wires and tension band wires were performed to treat dislocations. All patients were followed up for 6 to 24 months, 10 months on average. According to Rockwood's rating scale on postoperative sternoclavicular joint, 8 cases achieved excellent outcomes with an average score of 13.88, and the rest case achieved a good outcome with the score of 12. Anatomical reduction was obtained in all cases. There were no such postoperative complications as severe infection, injury to blood vessel and nerve, failure of fixation, etc. Patients were all satisfied with the anatomical reduction and functional recovery. The technique of K-wire and tension band wire fixation is safe, simple, effective, less invasive and has been successfully used in orthopedic surgery. It is effective in treating sternoclavicular joint dislocation though it has some disadvantages.

A feasibility study of high intensity positron sources for the S-band and TESLA linear colliders

Energy Technology Data Exchange (ETDEWEB)

Glantz, R.

1997-10-01

Future high energy linear colliders require luminosities above 10{sup 33} cm{sup -2}s{sup -1}. Therefore beam intensities have to be provided up to two orders of magnitude higher than achieved at present. It is comparably simple to reach high electron intensities. Positron intensities in this range, however, are difficult to realize with conventional positron sources. A new method of positron production was proposed in 1979 by V.E. Balakin and A.A. Mikhailichenko. The photons, necessary for pair production, are not generated by bremsstrahlung but by high energy electrons passing through an undulator. Based on this principle, a high intensity, unpolarized and polarized positron source for linear colliders was developed by K.Floettmann. In the present work, the requirements derived by K.Floettmann are used to study the feasibility of both the polarized and the unpolarized positron source. For economical reasons it is advantageous to use the beam after the interaction for positron production. In the main part of the present work a beam line is developed which guarantees a stable operation of the unpolarized wiggler-based positron source for the S-Band and TESLA linear collider. The requirements on the electron beam emittances are much higher for the polarized undulator-based source. For TESLA it is shown, that an operation of the polarized source is possible for design interactions. For a stable operation, taking into account perturbations at the interaction point, further investigations are necessary. For the SBLC, an operation of the polarized source is not possible with the present design.

First observation of $\\pi^{-}K^+$ and $\\pi^{+}K^-$ atoms, their lifetime measurement and $\\pi K$ scattering lengths evaluation

CERN Document Server

Afanasyev, Leonid

2016-01-01

The Low Energy QCD allows to calculate the ππ and π K scattering lengths with high precision. There are accurate relations between these scattering lengths and π + π − , π − K + , π + K − atoms lifetimes. The experiment on the first observation of π − K + and π + K − atoms is described. The atoms were generated in Nickel and Platinum targets hit by the PS CERN proton beam with momentum of 24 GeV/ c . Moving in the target, part of atoms break up producing characteristic π K pairs (atomic pairs) with small relative momentum Q in their c.m.s. In the experiment, we detected n A = 349 ± 62 (5.6 standard deviations) π − K + and π + K − atomic pairs. The main part of π K pairs are produced in free state. The majority of such particles are generated directly or from short-lived sources as ρ , ω and similar resonances. The electromagnetic interactions in the final state create Coulomb pairs with a known sharp dependence on Q . This effect allows to evaluate the number of these Coulomb pai...

Lunar Reconnaissance Orbiter K-Band (26 GHz) Signal Analysis: Initial Study Results

Science.gov (United States)

Morabito, D. D.; Heckman, D.

2017-11-01

Lower frequency telemetry bands are becoming more limited in bandwidth due to increased competition between flight projects and other entities. Higher frequency bands offer significantly more bandwidth and hence the prospect of much higher data rates. Future or prospective flight projects considering higher frequency bands such as Ka-band (32 GHz) for deep-space and K-band (26 GHz) for near-Earth telemetry links are interested in past flight experience with available received data at these frequencies. Given that there is increased degradation due to the atmosphere at these higher frequencies, there is an effort to retrieve flight data of received signal strength to analyze performance under a variety of factors. Such factors include elevation angle, season, and atmospheric conditions. This article reports on the analysis findings of over 10 million observations of received signal strength of the Lunar Reconnaissance Orbiter (LRO) spacecraft collected between 2014 and 2017. We analyzed these data to characterize link performance over a wide range of weather conditions, season, and as a function of elevation angle. Based on this analysis, we have confirmed the safety of using a 3-dB margin for preflight planning purposes. These results suggest that a 3-dB margin with respect to adverse conditions will ensure a 98 to 99 percent data return under 95 percent weather conditions at 26 GHz (K-band), thus confirming expectations from link budget predictions. The results suggest that this margin should be applicable for all elevation angles above 10 deg. Thus, missions that have sufficient power for their desired data rates may opt to use 10 deg as their minimum elevation angle. Limitations of this study include climate variability and the fact that the observations require removal of hotbody noise in order to perform an adequate cumulative distribution function (CDF) analysis, which is planned for a future comprehensive study. Flight projects may use other link margins

Characterization and Preparation of Broken Rice Proteins Modified by Proteases

Directory of Open Access Journals (Sweden)

Lixia Hou

2010-01-01

Full Text Available Broken rice is an underutilized by-product of milling. Proteins prepared from broken rice by treatments with alkaline protease and papain have been characterized with regard to nutritional and functional properties. The protein content and the protein recovery were 56.45 and 75.45 % for alkaline protease treatment, and 65.45 and 46.32 % for papain treatment, respectively. Protease treatment increased the lysine and valine content, leading to a more balanced amino acid profile. Broken rice proteins had high emulsifying capacity, 58.3–71.6 % at neutral pH, and adequate water holding capacity, ranging from 1.96 to 2.93 g/g of proteins. At pH=7.0, the broken rice protein had the highest water holding capacity and the best interfacial activities (emulsifying capacity, emulsifying stability, foaming capacity and foaming stability, which may be the result of the higher solubility at pH=7.0. The interfacial activities increased with the increase in the mass fraction of broken rice proteins. The proteins prepared by the papain treatment had higher water holding capacity (p>0.05, emulsifying capacity (p0.05 than alkaline protease treatment at the same pH or mass fraction. To test the fortification of food products with broken rice proteins, pork sausages containing the proteins were prepared. Higher yield of the sausages was obtained with the increased content of broken rice proteins, in the range of 2.0–9.0 %. The results indicate that broken rice proteins have potential to be used as the protein fortification ingredient for food products.

Isovectorial pairing in solvable and algebraic models

International Nuclear Information System (INIS)

Lerma, Sergio; Vargas, Carlos E; Hirsch, Jorge G

2011-01-01

Schematic interactions are useful to gain some insight in the behavior of very complicated systems such as the atomic nuclei. Prototypical examples are, in this context, the pairing interaction and the quadrupole interaction of the Elliot model. In this contribution the interplay between isovectorial pairing, spin-orbit, and quadrupole terms in a harmonic oscillator shell (the so-called pairing-plus-quadrupole model) is studied by algebraic methods. The ability of this model to provide a realistic description of N = Z even-even nuclei in the fp-shell is illustrated with 44 Ti. Our calculations which derive from schematic and simple terms confirm earlier conclusions obtained by using realistic interactions: the SU(3) symmetry of the quadrupole term is broken mainly by the spin-orbit term, but the energies depends strongly on pairing.

Highly vibrationally excited O2 molecules in low-pressure inductively-coupled plasmas detected by high sensitivity ultra-broad-band optical absorption spectroscopy

Science.gov (United States)

Foucher, Mickaël; Marinov, Daniil; Carbone, Emile; Chabert, Pascal; Booth, Jean-Paul

2015-08-01

Inductively-coupled plasmas in pure O2 (at pressures of 5-80 mTorr and radiofrequency power up to 500 W) were studied by optical absorption spectroscopy over the spectral range 200-450 nm, showing the presence of highly vibrationally excited O2 molecules (up to vʺ = 18) by Schumann-Runge band absorption. Analysis of the relative band intensities indicates a vibrational temperature up to 10,000 K, but these hot molecules only represent a fraction of the total O2 density. By analysing the (11-0) band at higher spectral resolution the O2 rotational temperature was also determined, and was found to increase with both pressure and power, reaching 900 K at 80 mTorr 500 W. These measurements were achieved using a new high-sensitivity ultra-broad-band absorption spectroscopy setup, based on a laser-plasma light source, achromatic optics and an aberration-corrected spectrograph. This setup allows the measurement of weak broadband absorbances due to a baseline variability lower than 2   ×   10-5 across a spectral range of 250 nm.

K-wire and tension band wire fixation in treating sternoclavicular joint dislocation

Directory of Open Access Journals (Sweden)

CHEN Qing-yu

2011-02-01

Full Text Available 【Abstract】Objective: To evaluate the feasibility and therapeutic effect of treating sternoclavicular joint dislocation by K-wire and tension band wire fixation, and to improve the safety and stability of this technique. Methods: This study consisted of 9 cases, 6 males and 3 females with the mean age of 25 years (range, 9-62 years. The causes were traffic accident in 7 cases, falling in 1 case and fight in 1 case. The duration from injury to operation was 2 hours to 7 days. There were 5 left dislocations and 4 right dislocations; 8 anterior dislocations and 1 posterior dislocation, including one combined with left scapular fracture and one with left olecranon fracture. Open reduction and internal fixation using K-wires and tension band wires were performed to treat dislocations. Results: All patients were followed up for 6 to 24 months, 10 months on average. According to Rockwood’s rating scale on postoperative sternoclavicular joint, 8 cases achieved excellent outcomes with an average score of 13.88, and the rest case achieved a good outcome with the score of 12. Anatomical reduction was obtained in all cases. There were no such postoperative complications as severe infection, injury to blood vessel and nerve, failure of fixation, etc. Patients were all satisfied with the anatomical reduction and functional recovery. Conclusions: The technique of K-wire and tension band wire fixation is safe, simple, effective, less invasive and has been successfully used in orthopedic surgery. It is effective in treating sternoclavicular joint dislocation though it has some disadvantages. Key words: Sternoclavicular joint; Dislocations; Bone wires; Fracture fixation, internal

HERSCHEL OBSERVATIONS OF MAJOR MERGER PAIRS AT z = 0: DUST MASS AND STAR FORMATION

International Nuclear Information System (INIS)

Cao, Chen; Xu, Cong Kevin; Lu, Nanyao; Mazzarella, Joe; Domingue, Donovan; Ronca, Joseph; Jacques, Allison; Buat, Veronique; Cheng, Yi-Wen; Gao, Yu; Huang, Jiasheng; Jarrett, Thomas H.; Lisenfeld, Ute; Sun, Wei-Hsin; Wu, Hong; Yun, Min S.

2016-01-01

We present Herschel PACS and SPIRE far-infrared (FIR) and submillimeter imaging observations for a large K-band selected sample of 88 close major-merger pairs of galaxies (H-KPAIRs) in 6 photometric bands (70, 100, 160, 250, 350, and 500 μm). Among 132 spiral galaxies in the 44 spiral–spiral (S+S) pairs and 44 spiral–elliptical (S+E) pairs, 113 are detected in at least 1 Herschel band. The star formation rate (SFR) and dust mass (M dust ) are derived from the IR SED fitting. The mass of total gas (M gas ) is estimated by assuming a constant dust-to-gas mass ratio of 0.01. Star-forming spiral galaxies (SFGs) in S+S pairs show significant enhancements in both specific star formation rate (sSFR) and star formation efficiency (SFE), while having nearly the same gas mass compared to control galaxies. On the other hand, for SFGs in S+E pairs, there is no significant sSFR enhancement and the mean SFE enhancement is significantly lower than that of SFGs in S+S pairs. This suggests an important role for the disk–disk collision in the interaction-induced star formation. The M gas of SFGs in S+E pairs is marginally lower than that of their counterparts in both S+S pairs and the control sample. Paired galaxies with and without interaction signs do not differ significantly in their mean sSFR and SFE. As found in previous works, this much larger sample confirms that the primary and secondary spirals in S+S pairs follow a Holmberg effect correlation on sSFR

GPI Spectra of HR8799 C, D, and E in H-K Bands with KLIP Forward Modeling

Science.gov (United States)

Greenbaum, Alexandra Z.; Pueyo, Laurent; Ruffio, Jean-Baptiste; Wang, Jason J.; De Rosa, Robert J.; Aguilar, Jonathan; Rameau, Julien; Barman, Travis; Marois, Christian; Marley, Mark S.;

Geometric phase and entanglement of Raman photon pairs in the presence of photonic band gap

International Nuclear Information System (INIS)

Berrada, K.; Ooi, C. H. Raymond; Abdel-Khalek, S.

2015-01-01

Robustness of the geometric phase (GP) with respect to different noise effects is a basic condition for an effective quantum computation. Here, we propose a useful quantum system with real physical parameters by studying the GP of a pair of Stokes and anti-Stokes photons, involving Raman emission processes with and without photonic band gap (PBG) effect. We show that the properties of GP are very sensitive to the change of the Rabi frequency and time, exhibiting collapse phenomenon as the time becomes significantly large. The system allows us to obtain a state which remains with zero GP for longer times. This result plays a significant role to enhance the stabilization and control of the system dynamics. Finally, we investigate the nonlocal correlation (entanglement) between the pair photons by taking into account the effect of different parameters. An interesting correlation between the GP and entanglement is observed showing that the PBG stabilizes the fluctuations in the system and makes the entanglement more robust against the change of time and frequency

Hetero-gate-dielectric double gate junctionless transistor (HGJLT) with reduced band-to-band tunnelling effects in subthreshold regime

International Nuclear Information System (INIS)

Ghosh, Bahniman; Mondal, Partha; Akram, M. W.; Bal, Punyasloka; Salimath, Akshay Kumar

2014-01-01

We propose a hetero-gate-dielectric double gate junctionless transistor (HGJLT), taking high-k gate insulator at source side and low-k gate insulator at drain side, which reduces the effects of band-to-band tunnelling (BTBT) in the sub-threshold region. A junctionless transistor (JLT) is turned off by the depletion of carriers in the highly doped thin channel (device layer) which results in a significant band overlap between the valence band of the channel region and the conduction band of the drain region, due to off-state drain bias, that triggers electrons to tunnel from the valence band of the channel region to the conduction band of the drain region leaving behind holes in the channel. These effects of band-to-band tunnelling increase the sub-threshold leakage current, and the accumulation of holes in the channel forms a parasitic bipolar junction transistor (n–p–n BJT for channel JLT) in the lateral direction by the source (emitter), channel (base) and drain (collector) regions in JLT structure in off-state. The proposed HGJLT reduces the subthreshold leakage current and suppresses the parasitic BJT action in off-state by reducing the band-to-band tunnelling probability. (semiconductor devices)

DSAM lifetime measurements for the chiral pair in {sup 194}Tl

Energy Technology Data Exchange (ETDEWEB)

Masiteng, P.L.; Bvumbi, S.P. [National Research Foundation, iThemba LABS, PO Box 722, Somerset West (South Africa); University of the Western Cape, Private Bag X17, Bellville (South Africa); University of Johannesburg, PO Box 524, Auckland Park (South Africa); Pasternak, A.A. [A.F. Ioffe Physical-Technical Institute, St.-Petersburg (Russian Federation); Lawrie, E.A.; Shirinda, O.; Lawrie, J.J.; Bark, R.A.; Kheswa, N.Y.; Lieder, E.O.; Lieder, R.M.; Mullins, S.M.; Murray, S.H.T. [National Research Foundation, iThemba LABS, PO Box 722, Somerset West (South Africa); Lindsay, R. [University of the Western Cape, Private Bag X17, Bellville (South Africa); Madiba, T.E.; Sharpey-Schafer, J.F. [National Research Foundation, iThemba LABS, PO Box 722, Somerset West (South Africa); University of the Western Cape, Private Bag X17, Bellville (South Africa); Ndayishimye, J.; Papka, P. [National Research Foundation, iThemba LABS, PO Box 722, Somerset West (South Africa); University of Stellenbosch, Department of Physics, Private Bag X1, Matieland (South Africa); Ntshangase, S.S. [National Research Foundation, iThemba LABS, PO Box 722, Somerset West (South Africa); University of Cape Town, Department of Physics, Private Bag, Rondebosch (South Africa)

2016-02-15

Most important for the identification of chiral symmetry in atomic nuclei is to establish a pair of bands that are near-degenerate in energy, but also in B(M1) and B(E2) transition probabilities. Dedicated lifetime measurements were performed for four bands of {sup 194}Tl, including the pair of four-quasiparticle chiral bands with close near-degeneracy, considered as a prime candidate for best chiral symmetry pair. The lifetime measurements confirm the excellent near-degeneracy in this pair and indicate that a third band may be involved in the chiral symmetry scenario. (orig.)

High-K structures in {sup 180}W and {sup 181}W

Energy Technology Data Exchange (ETDEWEB)

Yeung, K C; Walker, P M; Singleton, B D.D. [Surrey Univ., Guildford (United Kingdom). Dept. of Physics; Urban, W; Lisle, J C; Copnell, J; Mo, J N [Manchester Univ. (United Kingdom). Schuster Lab.; Joyce, M J [Liverpool Univ. (United Kingdom). Oliver Lodge Lab.; Gjorup, N L; Sletten, G [Risoe National Lab., Roskilde (Denmark)

1992-08-01

In each of the prolate-deformed isotopes {sup 180}W and {sup 181}W, a very high-K non-collective state has been found which decays directly into the corresponding collective ground-state rotational band. There is complete breakdown of the K-selection rule, in contrast to the partial breakdown observed recently in {sup 174}Hf and {sup 182}Os. Nevertheless, the non-collective states themselves retain characteristics associated with a prolate axially symmetric shape, implying that K is still a useful quantum number. (author). 17 refs., 2 figs.

Offline detection of broken rotor bars in AC induction motors

Science.gov (United States)

Powers, Craig Stephen

ABSTRACT. OFFLINE DETECTION OF BROKEN ROTOR BARS IN AC INDUCTION MOTORS. The detection of the broken rotor bar defect in medium- and large-sized AC induction machines is currently one of the most difficult tasks for the motor condition and monitoring industry. If a broken rotor bar defect goes undetected, it can cause a catastrophic failure of an expensive machine. If a broken rotor bar defect is falsely determined, it wastes time and money to physically tear down and inspect the machine only to find an incorrect diagnosis. Previous work in 2009 at Baker/SKF-USA in collaboration with the Korea University has developed a prototype instrument that has been highly successful in correctly detecting the broken rotor bar defect in ACIMs where other methods have failed. Dr. Sang Bin and his students at the Korea University have been using this prototype instrument to help the industry save money in the successful detection of the BRB defect. A review of the current state of motor conditioning and monitoring technology for detecting the broken rotor bar defect in ACIMs shows improved detection of this fault is still relevant. An analysis of previous work in the creation of this prototype instrument leads into the refactoring of the software and hardware into something more deployable, cost effective and commercially viable.

Electron and hole photoemission detection for band offset determination of tunnel field-effect transistor heterojunctions

International Nuclear Information System (INIS)

Li, Wei; Zhang, Qin; Kirillov, Oleg A.; Levin, Igor; Richter, Curt A.; Gundlach, David J.; Nguyen, N. V.; Bijesh, R.; Datta, S.; Liang, Yiran; Peng, Lian-Mao; Liang, Xuelei

2014-01-01

We report experimental methods to ascertain a complete energy band alignment of a broken-gap tunnel field-effect transistor based on an InAs/GaSb hetero-junction. By using graphene as an optically transparent electrode, both the electron and hole barrier heights at the InAs/GaSb interface can be quantified. For a Al 2 O 3 /InAs/GaSb layer structure, the barrier height from the top of the InAs and GaSb valence bands to the bottom of the Al 2 O 3 conduction band is inferred from electron emission whereas hole emissions reveal the barrier height from the top of the Al 2 O 3 valence band to the bottom of the InAs and GaSb conduction bands. Subsequently, the offset parameter at the broken gap InAs/GaSb interface is extracted and thus can be used to facilitate the development of predicted models of electron quantum tunneling efficiency and transistor performance

Structure of stable degeneration of K3 surfaces into pairs of rational elliptic surfaces

OpenAIRE

Kimura, Yusuke

2018-01-01

F-theory/heterotic duality is formulated in the stable degeneration limit of a K3 fibration on the F-theory side. In this note, we analyze the structure of the stable degeneration limit. We discuss whether stable degeneration exists for pairs of rational elliptic surfaces. We demonstrate that, when two rational elliptic surfaces have an identical complex structure, stable degeneration always exists. We provide an equation that systematically describes the stable degeneration of a K3 surface i...

Optical study of the band structure of wurtzite GaP nanowires

KAUST Repository

Assali, S.

2016-07-25

We investigated the optical properties of wurtzite (WZ) GaP nanowires by performing photoluminescence (PL) and time-resolved PL measurements in the temperature range from 4 K to 300 K, together with atom probe tomography to identify residual impurities in the nanowires. At low temperature, the WZ GaP luminescence shows donor-acceptor pair emission at 2.115 eV and 2.088 eV, and Burstein-Moss band-filling continuum between 2.180 and 2.253 eV, resulting in a direct band gap above 2.170 eV. Sharp exciton α-β-γ lines are observed at 2.140–2.164–2.252 eV, respectively, showing clear differences in lifetime, presence of phonon replicas, and temperature-dependence. The excitonic nature of those peaks is critically discussed, leading to a direct band gap of ∼2.190 eV and to a resonant state associated with the γ-line ∼80 meV above the Γ8C conduction band edge.

Optical study of the band structure of wurtzite GaP nanowires

KAUST Repository

Assali, S.; Greil, J.; Zardo, I.; Belabbes, Abderrezak; de Moor, M. W. A.; Koelling, S.; Koenraad, P. M.; Bechstedt, F.; Bakkers, E. P. A. M.; Haverkort, J. E. M.

2016-01-01

We investigated the optical properties of wurtzite (WZ) GaP nanowires by performing photoluminescence (PL) and time-resolved PL measurements in the temperature range from 4 K to 300 K, together with atom probe tomography to identify residual impurities in the nanowires. At low temperature, the WZ GaP luminescence shows donor-acceptor pair emission at 2.115 eV and 2.088 eV, and Burstein-Moss band-filling continuum between 2.180 and 2.253 eV, resulting in a direct band gap above 2.170 eV. Sharp exciton α-β-γ lines are observed at 2.140–2.164–2.252 eV, respectively, showing clear differences in lifetime, presence of phonon replicas, and temperature-dependence. The excitonic nature of those peaks is critically discussed, leading to a direct band gap of ∼2.190 eV and to a resonant state associated with the γ-line ∼80 meV above the Γ8C conduction band edge.

Valence band structure and density of states effective mass model of biaxial tensile strained silicon based on k · p theory

International Nuclear Information System (INIS)

Kuang Qian-Wei; Liu Hong-Xia; Wang Shu-Long; Qin Shan-Shan; Wang Zhi-Lin

2011-01-01

After constructing a stress and strain model, the valence bands of in-plane biaxial tensile strained Si is calculated by k · p method. In the paper we calculate the accurate anisotropy valance bands and the splitting energy between light and heavy hole bands. The results show that the valance bands are highly distorted, and the anisotropy is more obvious. To obtain the density of states (DOS) effective mass, which is a very important parameter for device modeling, a DOS effective mass model of biaxial tensile strained Si is constructed based on the valance band calculation. This model can be directly used in the device model of metal—oxide semiconductor field effect transistor (MOSFET). It also a provides valuable reference for biaxial tensile strained silicon MOSFET design. (condensed matter: electronic structure, electrical, magnetic, and optical properties)

Effect on the variation of the moment of inertia in band K=1/2

International Nuclear Information System (INIS)

Liu Yanxin; Yu Shaoying; Inner Mongolia Univ. for Nationalities, Tongliao; Chinese Academy of Sciences, Beijing

2004-01-01

The effect on the variation of the moment of inertia in band 171 Yb[521]1/2 is investigated using the particle number conserving (PNC) method for treating the cranked shell model with monopole and Y 20 quadrupole pairing interactions. The experimental moments of inertia of 171 Yb[521]1/2 (signature α=±1/2) and the blocking effect of proton are reproduced well by the PNC calculation, in which no free parameter is involved. (authors)

Two band superconductivity for MgB{sub 2}: T{sub c} and isotope exponent {alpha} as a function of the carrier number n and the role of the center of the band

Energy Technology Data Exchange (ETDEWEB)

Rodriguez-Nunez, J J [Lab. SUPERCOMP, Departamento de Fisica - FACYT - UC, Valencia (Venezuela) and Abdus Salam International Centre for Theoretical Physics, Trieste (Italy); Schmidt, A A [Departamento de Matematica, UFSM, Santa Maria, RS (Brazil); Bianconi, A [Physics Department, Universita di Roma, Rome (Italy); Perali, A [Physics Department, University of Camerino, Camerino - MC (Italy)

2005-08-15

We study a two band superconducting, assuming that we have two tight binding bands, {epsilon}{sub 2}(k-vector) = {epsilon}{sub 2}{sup (0)} - t{sub 2}[cos(k{sub x}) + cos(k{sub y}) + s{sub 2} cos(k{sub z})] - {mu} and {epsilon}{sub 3}(k-vector) {epsilon}{sub 3}{sup (0)} - t{sub 3} [cos(k{sub x}) + cos(k{sub y})+s{sub 3} cos(k{sub z})] - {mu}. We solve the two gap equations at T = T{sub c} and calculate T{sub c} x n and {mu} x n for various values of pairing interaction, V, and Debye frequency, {omega}{sub D}. Also, from an expression developed in a previous paper by two of the present authors, we calculate {alpha} x n, where n is the number of carriers per site per band and {alpha} is the isotope exponent. We take only interband scattering, V, as a first approach. We find that in order to have superconductivity (T{sub c} {ne} 0), large values of V are necessary. Also, for V/{omega}{sub D} > 1, we obtain {alpha} > 1.00 and for V/{omega}{sub D}>1.00, the isotope exponent becomes less than 1. (author)

Highly Depleted Ethane and Mildly Depleted Methanol in Comet 21P/Giacobini-Zinner: Application of a New Empirical nu(sub 2) Band Model for CH30H Near 50 K

Science.gov (United States)

DiSanti, M. A.; Bonev, B. P.; Villanueva, G. L.; Mumma, M. J.

2012-01-01

Infrared spectra of Comet 2lP/Giacobini-Zinner (hereafter 2IP/GZ) were obtained using NIRSPEC at Keck II on UT 2005 June 03, approximately one month before perihelion, that simultaneously measured H2O, C2H6, and CH3OH. For H2O, the production rate of 3.8 x 10(exp 28) molecules / S was consistent with that measured during other apparitions of 21P/GZ retrieved from optical, infrared, and mm-wavelength observations. The water analysis also provided values for rotational temperature (T(sub rot) = 55(epx +3) /-.2 K) and the abundance ratio of ortho- and para-water (3.00 +/-0.15, implying a spin temperature exceeding 50 K). Six Q-branches in the V7 band of C2H6 provided a production rate (5.27 +/- 0.90 x 10(exp 25)/S) that corresponded to an abundance ratio of 0.139 +/- 0.024 % relative to H2O, confirming the previously reported strong depletion of C2H6 from IR observations during the 1998 apparition, and in qualitative agreement with the depletion in C2 known from optical studies. For CH30H, we applied our recently published ab initia model for the v3 band to obtain a rotational temperature (48(exp + 10) / -7 K) consistent with that obtained for H2O. In addition we applied a newly developed empirical model for the CH30H v2 band, and obtained a production rate consistent with that obtained from the v3 band. Combining results from both v2 and v3 bands provided a production rate (47.5 +/- 4.4 x 10(exp 25) / S) that corresponded to an abundance ratio of 1.25 +/- 0.12 % relative to H2O in 21P/GZ. Our study provides the first measure of primary volatile production rates for any Jupiter family comet over multiple apparitions using high resolution IR spectroscopy.

Strength Assessment of Broken Rock Postgrouting Reinforcement Based on Initial Broken Rock Quality and Grouting Quality

Directory of Open Access Journals (Sweden)

Hongfa Xu

2017-01-01

Full Text Available To estimate postgrouting rock mass strength growth is important for engineering design. In this paper, using self-developed indoor pressure-grouting devices, 19 groups of test cubic blocks were made of the different water cement ratio grouting into the broken rock of three kinds of particle sizes. The shear strength parameters of each group under different conditions were tested. Then this paper presents a quantitative calculation method for predicting the strength growth of grouted broken rock. Relational equations were developed to investigate the relationship between the growth rates of uniaxial compressive strength (UCS, absolute value of uniaxial tensile strength (AUTS, internal friction angle, and cohesion for post- to pregrouting broken rock based on Mohr-Coulomb strength criterion. From previous test data, the empirical equation between the growth rate of UCS and the ratio of the initial rock mass UCS to the grout concretion UCS has been determined. The equations of the growth rates of the internal friction coefficient and UCS for grouting broken rock with rock mass rating (RMR and its increment have been established. The calculated results are consistent with the experimental results. These observations are important for engineered design of grouting reinforcement for broken rock mass.

Characterization of Na+K+-ATPase in bovine sperm.

Science.gov (United States)

Hickey, Katie D; Buhr, Mary M

2012-04-15

Existing as a ubiquitous transmembrane protein, Na(+)K(+)-ATPase affects sperm fertility and capacitation through ion transport and a recently identified signaling function. Functional Na(+)K(+)-ATPase is a dimer of α and β subunits, each with isoforms (four and three, respectively). Since specific isoform pairings and locations may influence or indicate function, the objective of this study was to identify and localize subunits of Na(+)K(+)-ATPase in fresh bull sperm by immunoblotting and immunocytochemistry using antibodies against α1 and 3, and all β isoforms. Relative quantity of Na(+)K(+)-ATPase in head plasma membranes (HPM's) from sperm of different bulls was determined by densitometry of immunoblot bands, and compared to bovine kidney. Sperm and kidney specifically bound all antibodies at kDa equivalent to commercial controls, and to additional lower kDa bands in HPM. Immunofluorescence of intact sperm confirmed that all isoforms were present in the head region of sperm and that α3 was also uniformly distributed post-equatorially. Permeabilization exposing internal membranes typically resulted in an increase in fluorescence, indicating that some antibody binding sites were present on the inner surface of the HPM or the acrosomal membrane. Deglycosylation of β1 reduced the kDa of bands in sperm, rat brain and kidney, with the kDa of the deglycosylated bands differing among tissues. Two-dimensional blots of β1 revealed three distinct spots. Based on the unique quantity, location and structure Na(+)K(+)-ATPase subunits in sperm, we inferred that this protein has unique functions in sperm. Copyright © 2012 Elsevier Inc. All rights reserved.

Fourier transform infrared spectroscopy of azide and cyanate ion pairs in AOT reverse micelles

Science.gov (United States)

Owrutsky, Jeffrey C.; Pomfret, Michael B.; Barton, David J.; Kidwell, David A.

2008-07-01

Evidence for ion pair formation in aqueous bis(2-ethylhexyl) sulfosuccinate (AOT) reverse micelles (RMs) was obtained from infrared spectra of azide and cyanate with Li+, Na+, K+, and NH4+ counterions. The anions' antisymmetric stretching bands near 2000 cm-1 are shifted to higher frequency (blueshifted) in LiAOT and to a lesser extent in NaAOT, but they are very similar to those in bulk water with K+ and NH4+ as the counterions. The shifts are largest for low values of wo=[water]/[AOT] and approach the bulk value with increasing wo. The blueshifts are attributed to ion pairing between the anions and the counterions. This interpretation is reinforced by the similar trend (Li+>Na+>K+) for producing contact ion pairs with the metal cations in bulk dimethyl sulfoxide (DMSO) solutions. We find no evidence of ion pairs being formed in NH4AOT RMs, whereas ammonium does form ion pairs with azide and cyanate in bulk DMSO. Studies are also reported for the anions in formamide-containing AOT RMs, in which blueshifts and ion pair formation are observed more than in the aqueous RMs. Ion pairs are preferentially formed in confined RM systems, consistent with the well established ideas that RMs exhibit reduced polarity and a disrupted hydrogen bonding network compared to bulk water and that ion-specific effects are involved in mediating the structure of species at interfaces.

Prediction Method for Rain Rate and Rain Propagation Attenuation for K-Band Satellite Communications Links in Tropical Areas

Directory of Open Access Journals (Sweden)

Baso Maruddani

2015-01-01

Full Text Available This paper deals with the prediction method using hidden Markov model (HMM for rain rate and rain propagation attenuation for K-band satellite communication link at tropical area. As is well known, the K-band frequency is susceptible of being affected by atmospheric condition, especially in rainy condition. The wavelength of K-band frequency which approaches to the size of rain droplet causes the signal strength is easily attenuated and absorbed by the rain droplet. In order to keep the quality of system performance for K-band satellite communication link, therefore a special attention has to be paid for rain rate and rain propagation attenuation. Thus, a prediction method for rain rate and rain propagation attenuation based on HMM is developed to process the measurement data. The measured and predicted data are then compared with the ITU-R recommendation. From the result, it is shown that the measured and predicted data show similarity with the model of ITU-R P.837-5 recommendation for rain rate and the model of ITU-R P.618-10 recommendation for rain propagation attenuation. Meanwhile, statistical data for measured and predicted data such as fade duration and interfade duration have insignificant discrepancy with the model of ITU-R P.1623-1 recommendation.

Indication for a K/sup π/ = 0- octupole band in 150Nd from electron scattering

International Nuclear Information System (INIS)

Creswell, C.; Hirsch, A.; Bertozzi, W.; Heisenberg, J.; Kowalski, S.; Sargent, C.P.; Turchinetz, W.; Dieperink, A.

1978-01-01

Recent electron scattering results on the 0.850 MeV level of 150 Nd, when analyzed in terms of the interacting boson model, are inconsistent with the interpretation of this level as a pure J/sup π/(K) = 2 + (0) state. Very recent (n,n'γ) work has shown this level to be a 1 - , 2 + doublet. Assuming this level to be the band head of a ''K/sup π/ = 0 - '' octupole band, a simple model is used to predict electron scattering form factors for the 0.850 MeV state and a 3 - octupole level observed at 0.931 MeV. Comparison is made between these predicted form factors and recent electron scattering data

Open-string models with broken supersymmetry

International Nuclear Information System (INIS)

Sagnotti, A.

2002-01-01

I review the salient features of three classes of open-string models with broken supersymmetry. These suffice to exhibit, in relatively simple settings, the two phenomena of 'brane supersymmetry' and 'brane supersymmetry breaking'. In the first class of models, to lowest order supersymmetry is broken both in the closed and in the open sectors. In the second class of models, to lowest order supersymmetry is broken in the closed sector, but is exact in the open sector, at least for the low-lying modes, and often for entire towers of string excitations. Finally, in the third class of models, to lowest order supersymmetry is exact in the closed (bulk) sector, but is broken in the open sector. Brane supersymmetry breaking provides a natural solution to some old difficulties met in the construction of open-string vacua. (author)

Open-string models with broken supersymmetry

International Nuclear Information System (INIS)

Sagnotti, Augusto

2000-01-01

We review the salient features of three classes of open-string models with broken supersymmetry. These suffice to exhibit, in relatively simple settings, the two phenomena of 'brane supersymmetry' and 'brane supersymmetry breaking'. In the first class of models, to lowest order supersymmetry is broken both in the closed and in the open sectors. In the second class of models, to lowest order supersymmetry is broken in the closed sector, but is exact in the open sector, at least for the low-lying modes, and often for entire towers of string excitations. Finally, in the third class of models, to lowest order supersymmetry is exact in the closed (bulk) sector, but is broken in the open sector. Brane supersymmetry breaking provides a natural solution to some old difficulties met in the construction of open-string vacua

Real-time 2D/3D registration using kV-MV image pairs for tumor motion tracking in image guided radiotherapy.

Science.gov (United States)

Furtado, Hugo; Steiner, Elisabeth; Stock, Markus; Georg, Dietmar; Birkfellner, Wolfgang

2013-10-01

Intra-fractional respiratory motion during radiotherapy leads to a larger planning target volume (PTV). Real-time tumor motion tracking by two-dimensional (2D)/3D registration using on-board kilo-voltage (kV) imaging can allow for a reduction of the PTV though motion along the imaging beam axis cannot be resolved using only one projection image. We present a retrospective patient study investigating the impact of paired portal mega-voltage (MV) and kV images on registration accuracy. Material and methods. We used data from 10 patients suffering from non-small cell lung cancer (NSCLC) undergoing stereotactic body radiation therapy (SBRT) lung treatment. For each patient we acquired a planning computed tomography (CT) and sequences of kV and MV images during treatment. We compared the accuracy of motion tracking in six degrees-of-freedom (DOF) using the anterior-posterior (AP) kV sequence or the sequence of kV-MV image pairs. Results. Motion along cranial-caudal direction could accurately be extracted when using only the kV sequence but in AP direction we obtained large errors. When using kV-MV pairs, the average error was reduced from 2.9 mm to 1.5 mm and the motion along AP was successfully extracted. Mean registration time was 188 ms. Conclusion. Our evaluation shows that using kV-MV image pairs leads to improved motion extraction in six DOF and is suitable for real-time tumor motion tracking with a conventional LINAC.

The evidence of unconventional pairing in heavy fermion superconductors and high-Tc superconductors

International Nuclear Information System (INIS)

Tien, C.; Wur, C.S.; Jiang, I.M.

1989-01-01

Recently there has been a great deal of interest in two classes of superconductors, heavy fermion superconductors and high T c copper oxide superconductors. The behavior and nature of superconductivity in these two classes of materials are very similar. The temperature dependences of spin-lattice relaxation time (T 1 ) and spin-spin relaxation time (T 2 ) of 9 Be in UBe 13 are quite similar to those of 63 Cu and 89 Y in YBa 2 Cu 3 O 7-δ . The Knight shift of UBe 13 is unchanged during the superconducting phase transition. The Knight shift of YBa 2 Cu 3 O 7-δ changes from the value in the normal state K n /K s = 1 at T ≥ T c to K n /K s = 0.5 at T = 6 K. Both do not approach zero as expected in BCS theory. The acoustic attenuation is enhanced just below T c instead of rapid drop near T c for these two superconducting system. Neither the enhancement, the temperature variation, nor any other anomalous behaviors appear to be mirrored in EPR data for heavy Fermion superconductors and high T c superconductors. This strongly suggests that the unconventional pairing mechanism which induces superconductivity in heavy fermion materials might also involve in high T c superconductors

Ion-pair high performance liquid chromatographic retention behavior of salicylic acid and its derivatives

Energy Technology Data Exchange (ETDEWEB)

Lee, K.W.; Chung, Y.S. [Chungbuk National University, Cheongju (Korea); Oh, S.K. [Handok Pharmaceuticals Co. Ltd., Chungbuk (Korea)

1999-06-01

The ion-pair high performance liquid chromatographic elution behavior of salicylic acid and its derivatives was studied with measuring capacity factor, k', changing the concentration of ion-pairing reagent (tetrabutylammonium chloride, TBACl) in mobile phase. As a result, it was found that k' of the samples increase at pH 7.2 as the TBACl concentration increase. The derivatives of salicylic acid were separated each other at an optimum mobile phase condition which was found from the observation of the retention behavior. The optimum mobile phase condition was methanol solution(MeOH:H{sub 2}O 30:70) containing 20 mM TBACl for the determination of salicylic acid and methanol solution (MeOH:H{sub 2}O 20:80) containing 40 mM TBACl for p-aminosalicylic acid at pH 7.2. The method has been applied for the analysis of the contents of salicylic acid derivatives in an aspirin tablet and a tuberculosis curing agent. 8 refs., 4 figs., 2 tabs.

Oblate L = 1 bands in 194,196-201Pb, and 193Hg

International Nuclear Information System (INIS)

Becker, J.A.; Kuhnert, A.; Stoyer, M.A.; Brinkman, M.J.; Wang, T.F.; Roy, N.; Cizewski, J.A.; Stephens, F.S.; Deleplanque, M.A.; Diamond, R.M.; Azaiez, F.; Macchiavelli, A.O.; Korten, W.; Draper, J.E.; California Univ., Berkeley, CA

1992-11-01

Reports of recent experiments have included observations of regular and irregular bands in neutron deficient Pb isotopes with A=194, 196--201. The bands are populated strongly in HI,xn reactions. The shared characteristics of the bands include: (1) Bandhead energies of few MeV; (2) High bandhead spin; (3) Large alignments; (4) Small dynamic moments of inertia, and (5) Strong L = 1 transitions and weaker L = 2 crossover transitions, with B(Ml/B(E2)) ∼ 20 μ 2 /e 2 b 2 . Lifetimes of band members in the 198 Pb regular band are B(Ml) ∼ 1 W.u., and B(E2) ∼ 10 W.u. (with large errors). These observations are consistent with an interpretation of the regular structures as collective oblate bands with both proton and neutron excitations involved; the closed proton shell at Z = 82 is broken, and coupled to v(i l3/2 ) -n excitations. The irregular structures may correspond to triaxial shapes, with similar orbits involved. A similar structure has been also found in 193 Hg

Broken-Rotor-Bar Diagnosis for Induction Motors

International Nuclear Information System (INIS)

Wang Jinjiang; Gao, Robert X; Yan Ruqiang

2011-01-01

Broken rotor bar is one of the commonly encountered induction motor faults that may cause serious motor damage to the motor if not detected timely. Past efforts on broken rotor bar diagnosis have been focused on current signature analysis using spectral analysis and wavelet transform. These methods require accurate slip estimation to localize fault-related frequency. This paper presents a new approach to broken rotor bar diagnosis without slip estimation, based on the ensemble empirical mode decomposition (EEMD) and the Hilbert transform. Specifically, the Hilbert transform first extracts the envelope of the motor current signal, which contains broken rotor fault-related frequency information. Subsequently, the envelope signal is adaptively decomposed into a number of intrinsic mode functions (IMFs) by the EEMD algorithm. Two criteria based on the energy and correlation analyses have been investigated to automate the IMF selection. Numerical and experimental studies have confirmed that the proposed approach is effective in diagnosing broken rotor bar faults for improved induction motor condition monitoring and damage assessment.

Kπ=0+ band moment of inertia anomaly

International Nuclear Information System (INIS)

Zeng, J.Y.; Wu, C.S.; Cheng, L.; Lin, C.Z.; China Center of Advanced Science and Technology

1990-01-01

The moments of inertia of K π =0 + bands in the well-deformed nuclei are calculated by a particle-number-conserving treatment for the cranked shell model. The very accurate solutions to the low-lying K π =0 + bands are obtained by making use of an effective K truncation. Calculations show that the main contribution to the moments of inertia comes from the nucleons in the intruding high-j orbits. Considering the fact that no free parameter is involved in the calculation and no extra inert core contribution is added, the agreement between the calculated and the observed moments of inertia of 0 + bands in 168 Er is very satisfactory

Quantum restoration of broken symmetry in onedimensional loop ...

Indian Academy of Sciences (India)

Home; Journals; Pramana – Journal of Physics; Volume 82; Issue 6. Quantum restoration of broken symmetry in ... Keywords. Non-local transformation; broken symmetry; sine-Gordon; sech interaction. ... A specific type of classically broken symmetry is restored in quantum theory. One-dimensional sine-Gordon system and ...

New high spin states and band termination in {sup 83}Y and {sup 84}Zr

Energy Technology Data Exchange (ETDEWEB)

Johnson, T.D.; Aprahamian, A. [University of Notre Dame, Notre Dame, Indiana 46556 (United States); Lister, C.J.; Blumenthal, D.J.; Crowell, B. [Argonne National Laboratory, Argonne, Illinois 60439 (United States); Chowdhury, P. [University of Massachusetts, Lowell, Massachusetts 01854 (United States); Fallon, P.; Machiavelli, A.O. [Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States)

1997-03-01

The gamma decay of high spin yrast states in {sup 83}Y up to I{sup {pi}}=59/2{sup +} and 53/2{sup {minus}} have been observed using the reaction {sup 58}Ni({sup 29}Si,3p) at 110 MeV and the Gammasphere Early Implementation Array. The level scheme has been substantially extended due to the observations of several new transitions in all of the bands. A sequence of transitions feeding into the positive parity yrast band above I{sup {pi}}=47/2{sup +} seems to be consistent with a noncollective oblate structure expected at these high spins. A similar cascade is found in the data for {sup 84}Zr. A new forking of the favored negative parity band is found which may be due to neutron alignment polarizing the core to a different shape. This suggests that the {open_quotes}isomeric{close_quote}{close_quote} band in {sup 83}Y, for which one more connecting transition was found, is of a similar nature to other high-K bands found in this region. Lifetime measurements in the unfavored negative parity band are consistent with cranking calculations which predict a nearly oblate shape with a deformation parameter {beta}{sub 2}{approx}0.2. A qualitative analysis of line shapes at very high spins suggests the persistence of collectivity in the yrast sequence to the highest excitations seen. {copyright} {ital 1997} {ital The American Physical Society}

"Off-the-Shelf" K2-EDTA for Calcific Band Keratopathy.

Science.gov (United States)

Lee, Marco E; Ouano, Dean P; Shapiro, Brett; Fong, Andrew; Coroneo, Minas T

2018-07-01

To explore the effectiveness of "off-the-shelf" dipotassium-ethylenediaminetetraacetic acid (K2-EDTA) as an alternative to sodium EDTA as chelation therapy in removal of calcific band keratopathy (CBK). This study was a retrospective case series involving 4 patients with CBK who underwent superficial keratectomy and subsequent chelation therapy with K2-EDTA in a single center (Coastal Eye Clinic) by the same surgeon. Visual acuity and symptomatic relief were the main outcomes measured in our study. All 4 participants in this study were female with an average age of 80.3 years. Three of the patients with reasonable baseline visual acuity experienced improved visual acuity at 1 month. The other patient with multiple ocular comorbidities and severely reduced visual potential reported symptomatic pain relief at 1-month follow-up after the intervention. K2-EDTA seems to be an effective alternative to disodium EDTA in its ability to clear calcific plaques and restore visual function. Because of the logistical difficulties associated with acquiring disodium EDTA, and the relative abundance of K2-EDTA in health-care facilities, we believe that our findings warrant further investigation into its use as a more accessible and cost-effective chelating agent in CBK.

Twin photon pairs in a high-Q silicon microresonator

Energy Technology Data Exchange (ETDEWEB)

Rogers, Steven; Lu, Xiyuan [Department of Physics and Astronomy, University of Rochester, Rochester, New York 14627 (United States); Jiang, Wei C. [Institute of Optics, University of Rochester, Rochester, New York 14627 (United States); Lin, Qiang, E-mail: qiang.lin@rochester.edu [Institute of Optics, University of Rochester, Rochester, New York 14627 (United States); Department of Electrical and Computer Engineering, University of Rochester, Rochester, New York 14627 (United States)

2015-07-27

We report the generation of high-purity twin photon pairs through cavity-enhanced non-degenerate four-wave mixing (FWM) in a high-Q silicon microdisk resonator. Twin photon pairs are created within the same cavity mode and are consequently expected to be identical in all degrees of freedom. The device is able to produce twin photons at telecommunication wavelengths with a pair generation rate as large as (3.96 ± 0.03) × 10{sup 5} pairs/s, within a narrow bandwidth of 0.72 GHz. A coincidence-to-accidental ratio of 660 ± 62 was measured, the highest value reported to date for twin photon pairs, at a pair generation rate of (2.47 ± 0.04) × 10{sup 4} pairs/s. Through careful engineering of the dispersion matching window, we have reduced the ratio of photons resulting from degenerate FWM to non-degenerate FWM to less than 0.15.

Isominkowskian theory of Cooper Pairs in superconductors

International Nuclear Information System (INIS)

Animalu, A.O.E.

1993-01-01

Via the use of Santilli's isominkowskian space, the author presents a relativistic extension of the author's recent treatment of the Cooper Pair in superconductivity based on the Lie-isotopic lifting of quantum mechanics known as Hadronic Mechanics. The isominkowskian treatment reduces the solution of the eiganvalue problem for the quasiparticle energy spectrum to a geometric problem of specifying the metric of the isominkowskian space inside the pair in various models of ordinary high T c superconductors. The use of an intriguing realization of the metric due to Dirac reduces the dimensionality of the interior space to two yielding a spin mutation from 1/2 to zero inside a Cooper pair in two-band BCS and Hubbard models. 12 refs

Highly-distorted and doubly-decoupled rotational bands in odd-odd nuclei

International Nuclear Information System (INIS)

McHarris, W.C.; Olivier, W.A.; Rios, A.; Hampton, C.; Chou, Wentsae; Aryaeinejad, R.

1991-01-01

Heavy-ion reactions induce large amounts of angular momentum; hence, they selectively populate rotationally-aligned particle states in compound nuclei. Such states tend to deexcite through similar states connected by large coriolis matrix elements, resulting in relatively few - but highly distorted - bands in the lower-energy portions of odd-odd spectra. The extreme cases of this are doubly-decoupled, K ∼ 1 (π 1/2 x ν 1/2) bands, whose γ transitions are the most intense in spectra from many light Re and Ir nuclei. The authors made a two-pronged assault on such bands, studying them via different HI reactions at different laboratories and using interacting-boson (IBFFA) calculations to aid in sorting them out. The authors are beginning to understand the types of (primarily coriolis) distortions involved and hope to grasp a handle on aspects of the p-n residual interaction, although the coriolis distortions are large enough to mask much of the latter. They also discuss similar but complementary effects in the light Pr region

Substrate integrated waveguide (SIW 3 dB coupler for K-Band applications

Directory of Open Access Journals (Sweden)

Khalid Nurehansafwanah

2017-01-01

Full Text Available This paper presented a designed coupler by using Rogers RO4003C with thickness (h 0.508 mm and relative permittivity (εr 3.55. The four port network coupler operates in K-band (18-27 GHz and design by using substrate integrated waveguide (SIW method. The reflection coefficient and isolation coefficient of propose Substrate Integrated Waveguide (SIW coupler is below than -10 dB. Meanwhile the coupler requirements are phase shift 90° between coupled port and output. SIW are high performance broadband interconnects with excellent immunity to electromagnetic interference and suitable for use in microwave and communication electronics, as well as increase bandwidth systems. The designs of coupler are investigated using CST Microwave Studio simulation tool. This proposed couplers are varied from parameters that cover the frequency range (21 -24 GHz and better performance of scattering (S-parameter.

Formation energies of local pairs in fullerene isomer mixtures

International Nuclear Information System (INIS)

Solecki, J.

1996-01-01

It is well-known that the alkali metal-doped fullerides are superconductors of type II. There were so far many trials to explain the pairing mechanism in the superconducting fullerides. A description of the superconducting mechanism in terms of the so-called local pair model has been proposed in this note. A purely electronic interaction was also considered within the resonating valence bond model (RVB). In fact, other models were not able to explain exactly why superconductivity appears for the stoichiometry of A 3 C 60 in the alkali metal-doped fullerides. An exception of this rule is, e.g., Ca 5 C 60 which is a superconductor with T c = 8.4 K. However, measurements show that electronic structures near the Fermi level of the A 3 C 60 (A = K, Rb) as well as the Ca 5 C 60 superconductors are remarkably similar although their charge carriers form energy bands of different character. Therefore, the results obtained for the stoichiometry A 3 C 60 can roughly refer to the Ca 5 C 60 case as well. (orig.)

Self Derogation and Childhood Broken Home

Science.gov (United States)

Kaplan, Howard B; Pokorny, Alex D.

1971-01-01

The data from this study makes clear that it is not the fact of broken homes per se that is related to self derogation but rather the particular characteristics of the broken home situation. Prediction of self derogation is also contingent upon such subject characteristics as race, sex and social class. (Author/CG)

Mixed-fault diagnosis in induction motors considering varying load and broken bars location

International Nuclear Information System (INIS)

Faiz, Jawad; Ebrahimi, Bashir Mahdi; Toliyat, H.A.; Abu-Elhaija, W.S.

2010-01-01

Simultaneous static eccentricity and broken rotor bars faults, called mixed-fault, in a three-phase squirrel-cage induction motor is analyzed by time stepping finite element method using fast Fourier transform. Generally, there is an inherent static eccentricity (below 10%) in a broken rotor bar induction motor and therefore study of the mixed-fault case could be considered as a real case. Stator current frequency spectrum over low frequencies, medium frequencies and high frequencies are analyzed; static eccentricity diagnosis and its distinguishing from the rotor bars breakage in the mixed-fault case are described. The contribution of the static eccentricity and broken rotor bars faults are precisely determined. Influence of the broken bars location upon the amplitudes of the harmonics due to the mixed-fault is also investigated. It is shown that the amplitudes of harmonics due to broken bars placed on one pole are larger than the case in which the broken bars are distributed on different poles. In addition, influence of varying load on the amplitudes of the harmonics due to the mixed-fault is studied and indicated that the higher load increases the harmonics components amplitudes due to the broken bars while the static eccentricity degree decreases. Simulation results are confirmed by the experimental results.

Observation of $\\pi^- K^+$ and $\\pi^+ K^-$ atoms

CERN Document Server

Adeva, B; The PS212 collaboration; Allkofer, Y.; Amsler, C.; Anania, A.; Aogaki, S.; Benelli, A.; Brekhovskikh, V.; Cechak, T.; Chiba, M.; Chliapnikov, P.; Doskarova, P.; Drijard, D.; Dudarev, A.; Dumitriu, D.; Fluerasu, D.; Gorin, A.; Gorchakov, O.; Gritsay, K.; Guaraldo, C.; Gugiu, M.; Hansroul, M.; Hons, Z.; Horikawa, S.; Iwashita, Y.; Karpukhin, V.; Kluson, J.; Kobayashi, M.; Kruglov, V.; Kruglova, L.; Kulikov, A.; Kulish, E.; Kuptsov, A.; Lamberto, A.; Lanaro, A.; Lednicky, R.; Marinas, C.; Martincik, J.; Nikitin, M.; Okada, K.; Olchevskii, V.; Pentia, M.; Penzo, A.; Plo, M.; Prusa, P.; Rappazzo, G.; Vidal, A.Romero; Ryazantsev, A.; Rykalin, V.; Saborido, J.; Sidorov, A.; Smolik, J.; Takeutchi, F.; Tauscher, L.; Trojek, T.; Trusov, S.; Urban, T.; Vrba, T.; Yazkov, V.; Yoshimura, Y.; Zhabitsky, M.; Zrelov, P.

2016-01-01

The observation of hydrogen-like $\\pi K$ atoms, consisting of $\\pi^- K^+$ or $\\pi^+ K^-$ mesons, is presented. The atoms have been produced by 24 GeV/$c$ protons from the CERN PS accelerator, interacting with platinum or nickel foil targets. The breakup (ionisation) of $\\pi K$ atoms in the same targets yields characteristic $\\pi K$ pairs, called ``atomic pairs'', with small relative momenta in the pair centre-of-mass system. The upgraded DIRAC experiment has observed $349\\pm62$ such atomic $\\pi K$ pairs, corresponding to a signal of 5.6 standard deviations.

Broken Homes: Stable Risk, Changing Reasons, Changing Forms.

Science.gov (United States)

Sweetser, Dorrian Apple

1985-01-01

Cohort membership and two measures of social disadvantage were used as explanatory variables in analysis of the risk of growing up in a broken home and of the living arrangements of children with broken homes. The risk of a broken home by age 16 proved to be stable across cohorts and greater for those from disadvantaged homes. (Author/BL)

Job loss and broken partnerships

DEFF Research Database (Denmark)

Kriegbaum, Margit; Christensen, Ulla; Lund, Rikke

2008-01-01

The aim of this study was to investigate the effects of the accumulated number of job losses and broken partnerships (defined as the end of cohabitation) on the risk of fatal and nonfatal events of ischemic heart disease (IHD).......The aim of this study was to investigate the effects of the accumulated number of job losses and broken partnerships (defined as the end of cohabitation) on the risk of fatal and nonfatal events of ischemic heart disease (IHD)....

Location of the valence band maximum in the band structure of anisotropic 1 T'-ReSe2

Science.gov (United States)

Eickholt, P.; Noky, J.; Schwier, E. F.; Shimada, K.; Miyamoto, K.; Okuda, T.; Datzer, C.; Drüppel, M.; Krüger, P.; Rohlfing, M.; Donath, M.

2018-04-01

Transition-metal dichalcogenides (TMDCs) are a focus of current research due to their fascinating optical and electronic properties with possible technical applications. ReSe2 is an interesting material of the TMDC family, with unique anisotropic properties originating from its distorted 1 T structure (1 T '). To develop a fundamental understanding of the optical and electric properties, we studied the underlying electronic structure with angle-resolved photoemission (ARPES) as well as band-structure calculations within the density functional theory (DFT)-local density approximation (LDA) and GdW approximations. We identified the Γ ¯M¯1 direction, which is perpendicular to the a axis, as a distinct direction in k space with the smallest bandwidth of the highest valence band. Using photon-energy-dependent ARPES, two valence band maxima are identified within experimental limits of about 50 meV: one at the high-symmetry point Z , and a second one at a non-high-symmetry point in the Brillouin zone. Thus, the position in k space of the global valence band maximum is undecided experimentally. Theoretically, an indirect band gap is predicted on a DFT-LDA level, while quasiparticle corrections lead to a direct band gap at the Z point.

Removal of a broken guide wire entrapped in a fractured femoral neck

Directory of Open Access Journals (Sweden)

ZHU Qing-hua

2013-08-01

Full Text Available 【Abstract】Guide wire plays an important role in the fixation of femoral neck fracture with dynamic hip screw (DHS. Breakage of a guide wire during operation is a very rare condition. We met such a dilemma in DHS fixation of a 54-year-old male patient who sustained Garden type IV frac-ture of the right femoral neck. The distal end of the guide wire broke and was entrapped in the fractured femoral neck. We tried to get the broken part out by a cannulated drill. Reaming was started with the cannulated drill slowly rotat-ing around the guide K-wire until the reamer fully contained the target under fluoroscope. A bone curette was used to get the broken wire out but failed, so we had to use the cannuated drill to dredge this bone tunnel. Finally the bro-ken wire end was taken out, mixed with blood and bone fragments. Through the existing drilling channel, DHS fixa-tion was easily finished. The patient had an uneventful re-covery without avascular necrosis of femoral head or non-union of the fracture at one year’s follow-up. A few methods can be adopted to deal with the broken guide wire. The way used in our case is less invasive but technically challenging. When the guide wire is properly positioned, this method is very practical and useful. Key words: Femoral neck fractures; Bones wires; Complications

Microscopic mechanism of identical multi-quasiparticle bands

International Nuclear Information System (INIS)

Lei Yian; Zhao Enguang; Zeng Jinyan

1997-01-01

Identical one-quasiparticle and two-quasiparticle bands in neighboring odd-and even-mass nuclei are recognized; The intrinsic structure of identical bands is demonstrated by using the particle-number-conserving (PNC) treatment. The occurrence of almost identical moments of inertia is the result of competition among the shell effect (including shape variation), pairing (anti-alignment) effect and blocking (anti-pairing) effect. The observed moments of inertia of identical multi-quasiparticle bands are reproduced quite well by the PNC calculation

Predissociation of high-lying Rydberg states of molecular iodine via ion-pair states

Energy Technology Data Exchange (ETDEWEB)

Bogomolov, Alexandr S. [Institute of Chemical Kinetics and Combustion, Institutskaya Str. 3, Novosibirsk 630090 (Russian Federation); Grüner, Barbara; Mudrich, Marcel [Physikalisches Institut, Universität Freiburg, D-79104 Freiburg (Germany); Kochubei, Sergei A. [Institute of Semiconductor Physics, ac. Lavrent' yev ave., 13, Novosibirsk 630090 (Russian Federation); Baklanov, Alexey V. [Institute of Chemical Kinetics and Combustion, Institutskaya Str. 3, Novosibirsk 630090 (Russian Federation); Novosibirsk State University, Pirogova Str. 2, Novosibirsk 630090 (Russian Federation)

2014-03-28

Velocity map imaging of the photofragments arising from two-photon photoexcitation of molecular iodine in the energy range 73 500–74 500 cm{sup −1} covering the bands of high-lying gerade Rydberg states [{sup 2}Π{sub 1/2}]{sub c}6d;0{sub g}{sup +} and [{sup 2}Π{sub 1/2}]{sub c}6d;2{sub g} has been applied. The ion signal was dominated by the atomic fragment ion I{sup +}. Up to 5 dissociation channels yielding I{sup +} ions with different kinetic energies were observed when the I{sub 2} molecule was excited within discrete peaks of Rydberg states and their satellites in this region. One of these channels gives rise to images of I{sup +} and I{sup −} ions with equal kinetic energy indicating predissociation of I{sub 2} via ion-pair states. The contribution of this channel was up to about 50% of the total I{sup +} signal. The four other channels correspond to predissociation via lower lying Rydberg states giving rise to excited iodine atoms providing I{sup +} ions by subsequent one-photon ionization by the same laser pulse. The ratio of these channels varied from peak to peak in the spectrum but their total ionic signal was always much higher than the signal of (2 + 1) resonance enhanced multi-photon ionization of I{sub 2}, which was previously considered to be the origin of ionic signal in this spectral range. The first-tier E0{sub g}{sup +} and D{sup ′}2{sub g} ion-pair states are concluded to be responsible for predissociation of Rydberg states [{sup 2}Π{sub 1/2}]{sub c}6d;0{sub g}{sup +} and [{sup 2}Π{sub 1/2}]{sub c}6d;2{sub g}, respectively. Further predissociation of these ion-pair states via lower lying Rydberg states gives rise to excited I(5s{sup 2}5p{sup 4}6s{sup 1}) atoms responsible for major part of ion signal. The isotropic angular distribution of the photofragment recoil directions observed for all channels indicates that the studied Rydberg states are long-lived compared with the rotational period of the I{sub 2} molecule.

Logotherapy Counseling to Improve Acceptance of Broken Home Child

Directory of Open Access Journals (Sweden)

Erwin Erlangga

2017-08-01

Full Text Available This study aims to increase the enrollment of children of a broken home that life has meaning. Subjects are 100 children in Demak whose families experiencing divorce. Research themes include three things: individual counseling, engineering logotherapy, reception, and a child of a broken home. Data obtained based on interviews, observation, and psychological scale showed that of the 100 children of a broken home has a low acceptance that individual counseling with logotherapy techniques were considered appropriate to increase the enrollment of children of a broken home. Factors - factors that affect the acceptance of a child of a broken home is self-blame, anger and did not have a purpose in life again. In addition the environment is also a significant effect on the enrollment of children of a broken home. Environmental labeling of families experiencing divorce as a family that failed so that children are increasingly stressed with the stamp of the community. Based on the field test results, the level of acceptance of the child of a broken home increases after the individual is given counseling services with logotherapy techniques. Indicated by changes in the level of acceptance of children of a broken home before being given treatment (initial evaluation and after (final evaluation of 130 points. The results of effectiveness test statistic t test calculations also showed 0,010 <0.05.It was concluded that counseling individuals with logotherapy effective technique to increase the enrollment of children of a broken home

Topological Nodal Cooper Pairing in Doped Weyl Metals

Science.gov (United States)

Li, Yi; Haldane, F. D. M.

2018-02-01

We generalize the concept of Berry connection of the single-electron band structure to that of a two-particle Cooper pairing state between two Fermi surfaces with opposite Chern numbers. Because of underlying Fermi surface topology, the pairing Berry phase acquires nontrivial monopole structure. Consequently, pairing gap functions have topologically protected nodal structure as vortices in the momentum space with the total vorticity solely determined by the pair monopole charge qp. The nodes of gap function behave as the Weyl-Majorana points of the Bogoliubov-de Gennes pairing Hamiltonian. Their relation with the connection patterns of the surface modes from the Weyl band structure and the Majorana surface modes inside the pairing gap is also discussed. Under the approximation of spherical Fermi surfaces, the pairing symmetry are represented by monopole harmonic functions. The lowest possible pairing channel carries angular momentum number j =|qp|, and the corresponding gap functions are holomorphic or antiholomorphic functions on Fermi surfaces. After projected on the Fermi surfaces with nontrivial topology, all the partial-wave channels of pairing interactions acquire the monopole charge qp independent of concrete pairing mechanism.

Pumping Electron-Positron Pairs from a Well Potential.

Science.gov (United States)

Wang, Qiang; Liu, Jie; Fu, Li-Bin

2016-04-29

In the presence of very deep well potential, electrons will spontaneously occupy the empty embedded bound states and electron-positron pairs are created by means of a non-perturbative tunneling process. In this work, by slowly oscillating the width or depth, the population transfer channels are opened and closed periodically. We find and clearly show that by the non-synchronous ejections of particles, the saturation of pair number in a static super-critical well can be broken, and electrons and positrons can be pumped inexhaustibly from vacuum with a constant production rate. In the adiabatic limit, final pair number after a single cycle has quantized values as a function of the upper boundary of the oscillating, and the critical upper boundaries indicate the diving points of the bound states.

Frequency-bin entanglement of ultra-narrow band non-degenerate photon pairs

Science.gov (United States)

Rieländer, Daniel; Lenhard, Andreas; Jime`nez Farìas, Osvaldo; Máttar, Alejandro; Cavalcanti, Daniel; Mazzera, Margherita; Acín, Antonio; de Riedmatten, Hugues

2018-01-01

We demonstrate frequency-bin entanglement between ultra-narrowband photons generated by cavity enhanced spontaneous parametric down conversion. Our source generates photon pairs in widely non-degenerate discrete frequency modes, with one photon resonant with a quantum memory material based on praseodymium doped crystals and the other photon at telecom wavelengths. Correlations between the frequency modes are analyzed using phase modulators and narrowband filters before detection. We show high-visibility two photon interference between the frequency modes, allowing us to infer a coherent superposition of the modes. We develop a model describing the state that we create and use it to estimate optimal measurements to achieve a violation of the Clauser-Horne (CH) Bell inequality under realistic assumptions. With these settings we perform a Bell test and show a significant violation of the CH inequality, thus proving the entanglement of the photons. Finally we demonstrate the compatibility with a quantum memory material by using a spectral hole in the praseodymium (Pr) doped crystal as spectral filter for measuring high-visibility two-photon interference. This demonstrates the feasibility of combining frequency-bin entangled photon pairs with Pr-based solid state quantum memories.

Model for predicting the frequency of broken rails

Directory of Open Access Journals (Sweden)

S. Vesković

2012-04-01

Full Text Available Broken rails can cause train delays, trains cancelations and, unfortunately, they are common causes of accidents. This affects planning of a resources, budget and organization of railway track maintenance. Planning of railway track maintenance cannot be done without an estimation of number of rails that will be replaced due to the broken rail incidents. There are many factors that influence broken rails and the most common are: rail age, annual gross tonnage, degree of curve and temperature in the time of breakage. The fuzzy logic model uses acquired data as input variables to predict the frequency of broken rails for the certain rail types on some Sections.

High gain harmonic generation free electron lasers enhanced by pseudoenergy bands

Directory of Open Access Journals (Sweden)

Takashi Tanaka

2017-08-01

Full Text Available We propose a new scheme for high gain harmonic generation free electron lasers (HGHG FELs, which is seeded by a pair of intersecting laser beams to interact with an electron beam in a modulator undulator located in a dispersive section. The interference of the laser beams gives rise to a two-dimensional modulation in the energy-time phase space because of a strong correlation between the electron energy and the position in the direction of dispersion. This eventually forms pseudoenergy bands in the electron beam, which result in efficient harmonic generation in HGHG FELs in a similar manner to the well-known scheme using the echo effects. The advantage of the proposed scheme is that the beam quality is less deteriorated than in other existing schemes.

A Multiple-Channel Sub-Band Transient Detection System

Energy Technology Data Exchange (ETDEWEB)

David A. Smith

1998-11-01

We have developed a unique multiple-channel sub-band transient detection system to record transient electromagnetic signals in carrier-dominated radio environments; the system has been used to make unique observations of weak, transient HF signals. The detection system has made these observations possible through improved sensitivity compared to conventional broadband transient detection systems; the sensitivity improvement is estimated to be at least 20 dB. The increase in sensitivity has been achieved through subdivision of the band of interest (an 18 MHz tunable bandwidth) into eight sub-band independent detection channels, each with a 400 kHz bandwidth and its own criteria. The system generates a system trigger signal when a predetermined number of channels (typically five) trigger within a predetermined window of time (typically 100 ~s). Events are recorded with a broadband data acquisition system sampling at 50 or 100 Msample/s, so despite the fact that the detection system operates on portions of the signal confined to narrow bands, data acquisition is broadband. Between May and September of 1994, the system was used to detect and record over six thousand transient events in the frequency band from 3 to 30 MHz. Approximately 500 of the events have been characterized as paired bursts of radio noise with individual durations of 2 to 10 ps and separations between the bursts of 5 to 160 ps. The paired transients are typically 5 to 40 dB brighter than the background electromagnetic spectrum between carrier signals. We have termed these events SubIonospheric Pulse Pairs (SIPPS) and presently have no explanation as to their source. Our observations of SIPPS resemble observations of TransIonospheric Pulse Pairs (TIPPs) recorded by the Blackboard instrument on the ALEXIS satellite; the source of TIPP events is also unknown. Most of the recorded SIPP events do not exhibit frequency dispersion, implying propagation along a line-of-sight (groundwave) path; but seven of

Nuclear pairing reduction due to rotation and blocking

International Nuclear Information System (INIS)

Wu Xi; Zhang Zhenhua; Lei Yi'an; Zeng Jinyan

2010-01-01

Nuclear pairing gaps of well-deformed and superdeformed nuclei are investigated using the particle-number conserving (PNC) formalism for the cranked shell model, in which the blocking effects are treated exactly and no spurious states appear. Both the rotational frequency ω-dependence and seniority ν-dependence of the pairing gap Δ-bar are addressed. For the ground-state bands of even-even nuclei, PNC calculations show that in general Δ-bar decreases with increasing ω, but the ω-dependence is much weaker than that calculated by the number-projected Hartree-Fock-Bogolyubov (NHFB) approach. For the multi quasiparticle bands (seniority ν > 2), the pairing gaps keep almost ω-independent. As a function of the seniority ν, the bandhead pairing gaps Δ-bar (ν, ω = 0) decrease slowly with increasing ν. Even for the highest seniority ν bands identified so far, Δ-bar (ν, ω = 0) keep 70% larger than Δ-bar (ν = 0, ω = 0). (authors)

Nuclear pairing reduction due to rotation and blocking

International Nuclear Information System (INIS)

Wu, X.; Zhang, Z. H.; Zeng, J. Y.; Lei, Y. A.

2011-01-01

Nuclear pairing gaps of normally deformed and superdeformed nuclei are investigated using the particle-number-conserving (PNC) formalism for the cranked shell model, in which the blocking effects are treated exactly. Both rotational frequency ω dependence and seniority (number of unpaired particles) ν dependence of the pairing gap Δ-tilde are investigated. For the ground-state bands of even-even nuclei, PNC calculations show that, in general, Δ-tilde decreases with increasing ω, but the ω dependence is much weaker than that calculated by the number-projected Hartree-Fock-Bogolyubov approach. For the multiquasiparticle bands (seniority ν>2), the pairing gaps stay almost ω independent. As a function of the seniority ν, the bandhead pairing gaps Δ-tilde(ν,ω=0) decrease slowly with increasing ν. Even for the highest seniority ν bands identified so far, Δ-tilde(ν,ω=0) remains greater than 70% of Δ-tilde(ν=0,ω=0).

Attenuation-based kV pair selection in dual source dual energy computed tomography angiography of the chest: impact on radiation dose and image quality

Energy Technology Data Exchange (ETDEWEB)

Renapurkar, Rahul D.; Azok, Joseph; Lempel, Jason; Karim, Wadih; Graham, Ruffin [Thoracic Imaging, L10, Imaging Institute, Cleveland Clinic, Cleveland, OH (United States); Primak, Andrew [Siemens Medical Solutions, Malvern, PA (United States); Tandon, Yasmeen [Case Western Reserve University-Metro Health Medical Center, Department of Radiology, Cleveland, OH (United States); Bullen, Jennifer [Quantitative Health Sciences, Cleveland Clinic, Cleveland, OH (United States); Dong, Frank [Section of Medical Physics, Cleveland Clinic, Cleveland, OH (United States)

2017-08-15

The purpose of this study was to evaluate the impact of attenuation-based kilovoltage (kV) pair selection in dual source dual energy (DSDE)-pulmonary embolism (PE) protocol examinations on radiation dose savings and image quality. A prospective study was carried out on 118 patients with suspected PE. In patients in whom attenuation-based kV pair selection selected the 80/140Sn kV pair, the pre-scan 100/140Sn CTDIvol (computed tomography dose index volume) values were compared with the pre-scan 80/140Sn CTDIvol values. Subjective and objective image quality parameters were assessed. Attenuation-based kV pair selection switched to the 80/140Sn kV pair (''switched'' cohort) in 63 out of 118 patients (53%). The mean 100/140Sn pre-scan CTDIvol was 8.8 mGy, while the mean 80/140Sn pre-scan CTDIvol was 7.5 mGy. The average estimated dose reduction for the ''switched'' cohort was 1.3 mGy (95% CI 1.2, 1.4; p < 0.001), representing a 15% reduction in dose. After adjusting for patient weight, mean attenuation was significantly higher in the ''switched'' vs. ''non-switched'' cohorts in all five pulmonary arteries and in all lobes on iodine maps. This study demonstrates that attenuation-based kV pair selection in DSDE examination is feasible and can offer radiation dose reduction without compromising image quality. (orig.)

Low-loss negative index metamaterials for X, Ku, and K microwave bands

Directory of Open Access Journals (Sweden)

David A. Lee

2015-04-01

Full Text Available Low-loss, negative-index of refraction metamaterials were designed and tested for X, Ku, and K microwave frequency bands. An S-shaped, split-ring resonator was used as a unit cell to design homogeneous slabs of negative-index metamaterials. Then, the slabs of metamaterials were cut unto prisms to measure experimentally the negative index of refraction of a plane electromagnetic wave. Theoretical simulations using High-Frequency Structural Simulator, a finite element equation solver, were in good agreement with experimental measurements. The negative index of refraction was retrieved from the angle- and frequency-dependence of the transmitted intensity of the microwave beam through the metamaterial prism and compared well to simulations; in addition, near-field electromagnetic intensity mapping was conducted with an infrared camera, and there was also a good match with the simulations for expected frequency ranges for the negative index of refraction.

Broken ergodicity in two-dimensional homogeneous magnetohydrodynamic turbulence

International Nuclear Information System (INIS)

Shebalin, John V.

2010-01-01

Two-dimensional (2D) homogeneous magnetohydrodynamic (MHD) turbulence has many of the same qualitative features as three-dimensional (3D) homogeneous MHD turbulence. These features include several ideal (i.e., nondissipative) invariants along with the phenomenon of broken ergodicity (defined as nonergodic behavior over a very long time). Broken ergodicity appears when certain modes act like random variables with mean values that are large compared to their standard deviations, indicating a coherent structure or dynamo. Recently, the origin of broken ergodicity in 3D MHD turbulence that is manifest in the lowest wavenumbers was found. Here, we study the origin of broken ergodicity in 2D MHD turbulence. It will be seen that broken ergodicity in ideal 2D MHD turbulence can be manifest in the lowest wavenumbers of a finite numerical model for certain initial conditions or in the highest wavenumbers for another set of initial conditions. The origins of broken ergodicity in an ideal 2D homogeneous MHD turbulence are found through an eigenanalysis of the covariance matrices of the probability density function and by an examination of the associated entropy functional. When the values of ideal invariants are kept fixed and grid size increases, it will be shown that the energy in a few large modes remains constant, while the energy in any other mode is inversely proportional to grid size. Also, as grid size increases, we find that broken ergodicity becomes manifest at more and more wavenumbers.

A Novel k-out-of-n Oblivious Transfer Protocol from Bilinear Pairing

Directory of Open Access Journals (Sweden)

Jue-Sam Chou

2012-01-01

Full Text Available Oblivious transfer (OT protocols mainly contain three categories: 1-out-of-2 OT, 1-out-of-n OT, and k-out-of-n OT. In most cases, they are treated as cryptographic primitives and are usually executed without consideration of possible attacks that might frequently occur in an open network, such as an impersonation, replaying, or man-in-the-middle attack. Therefore, when used in certain applications, such as mental poker games and fair contract signings, some extra mechanisms must be combined to ensure the security of the protocol. However, after a combination, we found that very few of the resulting schemes are efficient enough in terms of communicational cost, which is a significant concern for generic commercial transactions. Therefore, we propose a novel k-out-of-n oblivious transfer protocol based on bilinear pairing, which not only satisfies the requirements of a k-out-of-n OT protocol, but also provides mutual authentication to resist malicious attacks. Meanwhile, it is efficient in terms of communication cost.

Atomic-scale Visualization of Electronic Nematicity and Cooper Pairing in Iron-based Superconductors

Science.gov (United States)

Allan, Milan P.

2013-03-01

The mechanism of high-temperature superconductivity in the relatively novel iron-based high-Tc superconductors is unresolved, both in terms of how the phases evolve with doping, and in terms of the actual Cooper pairing process. To explore these issues, we used spectroscopic-imaging scanning tunneling microscopy to study the electronic structure of CaFe2As2 in the antiferromagnetic-orthorhombic `parent' state from which the superconductivity emerges. We discovered and visualized the now widely studied electronic `nematicity' of this phase, whose suppression is associated with the emergence of superconductivity (Science 327, 181, 2010). As subsequent transport experiments discovered a related anisotropic conductance which increases with dopant concentration, the interplay between the electronic structure surrounding each dopant atom, quasiparticle scattering therefrom, and the transport nematicity has become a pivotal focus of research. We find that substituting Co for Fe atoms in underdoped Ca(Fe1-xCox)2As2 generates a dense population of identical and strongly anisotropic impurity states that are distributed randomly but aligned with the antiferromagnetic a-axis. We also demonstrate, by imaging their surrounding interference patterns, that these impurity states scatter quasiparticles and thus influence transport in a highly anisotropic manner (M.P. Allan et al., 2013). Next, we studied the momentum dependence of the energy gaps of iron-based superconductivity, now focusing on LiFeAs. If strong electron-electron interactions mediate the Cooper pairing, then momentum-space anisotropic superconducting energy gaps Δi (k) were predicted by multiple techniques to appear on the different electronic bands i. We introduced intraband Bogoliubov quasiparticle scattering interference (QPI) techniques for the determination of anisotropic energy gaps to test these hypotheses and discovered the anisotropy, magnitude, and relative orientations of the energy gaps on multiple

Perilaku Agresif Siswa dari Keluarga Broken Home

Directory of Open Access Journals (Sweden)

Randi Pratama

2016-12-01

Full Text Available This research is based because of the aggressive behavior shown by the students, especially students who come from a broken home. The purpose of this study is to describe the aggressive behavior that is owned by a student who comes from a broken home in terms of attacking people physically, verbally, and damaging and destroying property and wealth of others. The results of this research shows that in general student’s aggressivebehavior are on average level. Implications of research in guidance and counseling is as the basis for programs to prevent and cope with aggressive behavior that is owned by the students, especially students who come from a broken home. Cooperation with the homeroom teacher mentors, teachers and other school personnel will also help identify students who have an aggressive behavior, especially students who come from a broken home to immediately provided services.

A high-gain and high-efficiency X-band triaxial klystron amplifier with two-stage cascaded bunching cavities

Science.gov (United States)

Zhang, Wei; Ju, Jinchuan; Zhang, Jun; Zhong, Huihuang

2017-12-01

To achieve GW-level amplification output radiation at the X-band, a relativistic triaxial klystron amplifier with two-stage cascaded double-gap bunching cavities is investigated. The input cavity is optimized to obtain a high absorption rate of the external injection microwave. The cascaded bunching cavities are optimized to achieve a high depth of the fundamental harmonic current. A double-gap standing wave extractor is designed to improve the beam wave conversion efficiency. Two reflectors with high reflection coefficients both to the asymmetric mode and the TEM mode are employed to suppress the asymmetric mode competition and TEM mode microwave leakage. Particle-in-cell simulation results show that a high power microwave with a power of 2.53 GW and a frequency of 8.4 GHz is generated with a 690 kV, 9.3 kA electron beam excitation and a 25 kW seed microwave injection. Particularly, the achieved power conversion efficiency is about 40%, and the gain is as high as 50 dB. Meanwhile, there is insignificant self-excitation of the parasitic mode in the proposed structure by adopting the reflectors. The relative phase difference between the injected signals and the output microwaves keeps locked after the amplifier becomes saturated.

Band-gap creation by icosahedral symmetry in nearly-free-electron materials

International Nuclear Information System (INIS)

Carlsson, A.E.

1993-01-01

A series of numerical electronic density-of-states calculations is performed for rational approximants to a model one-electron potential based on icosahedrally arranged plane-wave components. It is found that high-order approximants can have band gaps even if the low-order approximants do not; furthermore, the magnitude of the gap increases with the order of the approximant. The results are interpreted via a two- and three-wave analysis of the energy eigenvalues at the pseudo-Jones-zone faces and edges. It is also found that the mechanism of band-gap reduction in the rational approximants is the presence of a small density of gap states. An analytic calculation shows that these gap states result from a splitting of threefold and pseudothreefold states at the valence-band edge when the icosahedral symmetry is broken. The splitting is proportional to the error with which the ratio between the approximant indices approximates τ, the golden mean. Finally, an application to the AlCuLi system is presented

Acousto-optic modulation of a photonic crystal nanocavity with Lamb waves in microwave K band

Energy Technology Data Exchange (ETDEWEB)

Tadesse, Semere A. [Department of Electrical and Computer Engineering, University of Minnesota, Minneapolis, Minnesota 55455 (United States); School of Physics and Astronomy, University of Minnesota, Minneapolis, Minnesota 55455 (United States); Li, Huan; Liu, Qiyu; Li, Mo, E-mail: moli@umn.edu [Department of Electrical and Computer Engineering, University of Minnesota, Minneapolis, Minnesota 55455 (United States)

2015-11-16

Integrating nanoscale electromechanical transducers and nanophotonic devices potentially can enable acousto-optic devices to reach unprecedented high frequencies and modulation efficiency. Here, we demonstrate acousto-optic modulation of a photonic crystal nanocavity using Lamb waves with frequency up to 19 GHz, reaching the microwave K band. The devices are fabricated in suspended aluminum nitride membrane. Excitation of acoustic waves is achieved with interdigital transducers with period as small as 300 nm. Confining both acoustic wave and optical wave within the thickness of the membrane leads to improved acousto-optic modulation efficiency in these devices than that obtained in previous surface acoustic wave devices. Our system demonstrates a scalable optomechanical platform where strong acousto-optic coupling between cavity-confined photons and high frequency traveling phonons can be explored.

Quantum mechanics versus local realism and a recent EPR experiment on K/sup 0/K/sup 0/ pairs

CERN Document Server

Foadi, R

1999-01-01

The interest of the Orsay Einstein-Podolsky-Rosen experiments of the eighties was limited by a loophole due to the photomultipliers' low detection efficiency. This limitation can be overcome in the case of neutral kaon pairs for which the detection efficiency is high. We show that for such pairs produced in the state J/sup PC/=1/sup --/ the prediction of local realism differ from those of standard quantum theory by 30561400r more. A natural extension of a recent experiment on antiproton annihilations at rest into kaon pairs (CPLEAR collaboration, A. Apostolakis et al., 1998) could lead to a decisive step forward in this matter. (19 refs).

Highly efficient exciplex formation via radical ion pair recombination in X-irradiated alkane solutions for luminophores with short fluorescence lifetimes.

Science.gov (United States)

Melnikov, Anatoly R; Kalneus, Evgeny V; Korolev, Valeri V; Dranov, Igor G; Kruppa, Alexander I; Stass, Dmitri V

2014-08-01

X-irradiation of alkane solutions of N,N-dimethylaniline with various organic luminophores produces characteristic emission bands ascribed to the corresponding exciplexes. In contrast to optical generation, which requires diffusion-controlled quenching of excited states, an additional channel of exciplex formation via irreversible recombination of radical ion pairs is operative here, which produces exciplexes in solution with high efficiency even for p-terphenyl and diphenylacetylene having fluorescence decay times of 0.95 ns and 8 ps, respectively. The exciplex emission band is sensitive to an external magnetic field and exerts a very large observed magnetic field effect of up to 20%, the maximum possible value under the conditions of the described experiment.

Band crossings in mercury nuclei: effect of occupation of i13/2 neutron orbits

International Nuclear Information System (INIS)

Khadkikar, S.B.; Praharaj, C.R.

1984-04-01

The K=0 + ground band and two rotation-aligned bands (K=1 + or K2 + two quasi-particle band and K=2 + four quasi-particle band) are studied in 198 Hg, 194 Hg and 190 Hg by angular momentum projection from Hartree-Fock and particle-hole intrinsic states. There is a first anomaly in these three nuclei around 8(h/2π) due to the crossing of the ground band and the two quasi-particle band. Because of the nature of occupation of i13/2 orbitals the four quasi-particle band is too highlying in 198 Hg and does not cross the two quasi-particle bands, while such a second crossing occurs in 194 Hg and 190 Hg near 20 (h/2π). (author)

Convergence of valence bands for high thermoelectric performance for p-type InN

International Nuclear Information System (INIS)

Li, Hai-Zhu; Li, Ruo-Ping; Liu, Jun-Hui; Huang, Ming-Ju

2015-01-01

Band engineering to converge the bands to achieve high valley degeneracy is one of effective approaches for designing ideal thermoelectric materials. Convergence of many valleys in the valence band may lead to a high Seebeck coefficient, and induce promising thermoelectric performance of p-type InN. In the current work, we have systematically investigated the electronic structure and thermoelectric performance of wurtzite InN by using the density functional theory combined with semiclassical Boltzmann transport theory. Form the results, it can be found that intrinsic InN has a large Seebeck coefficient (254 μV/K) and the largest value of Z e T is 0.77. The transport properties of p-type InN are better than that of n-type one at the optimum carrier concentration, which mainly due to the large Seebeck coefficient for p-type InN, although the electrical conductivity of n-type InN is larger than that of p-type one. We found that the larger Seebeck coefficient for p-type InN may originate from the large valley degeneracy in the valence band. Moreover, the low minimum lattice thermal conductivity for InN is one key factor to become a good thermoelectric material. Therefore, p-type InN could be a potential material for further applications in the thermoelectric area.

"Broken Expectations" from a Global Business Perspective

NARCIS (Netherlands)

Koca, A.; Karapanos, E.; Brombacher, A.C.

2009-01-01

Especially in the past few years, there has been an increase in the rejection rate of interactive consumer electronics products in the field, not due to broken hardware or software, but due to ‘broken expectations’ of users. However, operational methods to capture triggering contextual reasons are

Nobel Prize for work on broken symmetries

CERN Multimedia

2008-01-01

The 2008 Nobel Prize for Physics goes to three physicists who have worked on broken symmetries in particle physics. The announcement of the 2008 Nobel Prize for physics was transmitted to the Globe of Science and Innovation via webcast on the occasion of the preview of the Nobel Accelerator exhibition.On 7 October it was announced that the Royal Swedish Academy of Sciences had awarded the 2008 Nobel Prize for physics to three particle physicists for their fundamental work on the mechanisms of broken symmetries. Half the prize was awarded to Yoichiro Nambu of Fermilab for "the discovery of the mechanism of spontaneous broken symmetry in subatomic physics". The other half is shared by Makato Kobayashi of Japan’s KEK Institute and Toshihide Maskawa of the Yukawa Institute at the University of Kyoto "for the discovery of the origin of the broken symmetry which predicts the existence of at least three families of quarks in Nature". At th...

Tensile and high cycle fatigue behaviors of high-Mn steels at 298 and 110 K

Energy Technology Data Exchange (ETDEWEB)

Seo, Wongyu; Jeong, Daeho; Sung, Hyokyung; Kim, Sangshik, E-mail: sang@gnu.ac.kr

2017-02-15

Tensile and high cycle fatigue behaviors of high-Mn austenitic steels, including 25Mn, 25Mn0.2Al, 25Mn0.5Cu, 24Mn4Cr, 22Mn3Cr and 16Mn2Al specimens, were investigated at 298 and 110 K. Depending on the alloying elements, tensile ductility of high-Mn steels either increased or decreased with decreasing temperature from 298 to 110 K. Reasonable correlation between the tendency for martensitic tranformation, the critical twinning stress and the percent change in tensile elongation suggested that tensile deformation of high-Mn steels was strongly influenced by SFE determining TRIP and TWIP effects. Tensile strength was the most important parameter in determining the resistance to high cycle fatigue of high-Mn steels with an exceptional work hardening capability at room and cryogenic temperatures. The fatigue crack nucleation mechanism in high-Mn steels did not vary with decreasing tempertature, except Cr-added specimens with grain boundary cracking at 298 K and slip band cracking at 110 K. The EBSD (electron backscatter diffraction) analyses suggested that the deformation mechanism under fatigue loading was significantly different from tensile deformation which could be affected by TRIP and TWIP effects. - Highlights: •The resistances to HCF of various high-Mn steels were measured. •The variables affecting tensile and HCF behaviors of high-Mn steels were assessed. •The relationship between tensile and the HCF behaviors of high-Mn steels was established.

Bag model with broken chiral symmetry

International Nuclear Information System (INIS)

Efrosinin, V.P.; Zaikin, D.A.

1986-01-01

A variant of the bag model in which chiral symmetry is broken and which provides a description of all the experimental data on the light hadrons, including the pion, is discussed. The pion and kaon decay constants are calculated in this model. The problem of taking into account the center-of-mass motion in bag models and the boundary conditions in the bag model with broken chiral symmetry are also discussed

Resolution of the 179W-isomer anomaly: Exposure of a Fermi-aligned s band

International Nuclear Information System (INIS)

Walker, P.M.; Dracoulis, G.D.; Byrne, A.P.; Fabricius, B.; Kibedi, T.; Stuchbery, A.E.; Department of Physics, University of Surrey, Guildford, GU2 5XH United Kingdom)

1991-01-01

The K π =35/2 - , five-quasiparticle isomer in 179 W is shown to decay into the region of a backbend in the 7/2 - [514] band, allowing for the first time the identification of a full set of aligned-band states. Destructive interference results from level mixing in the band-crossing region. The deduced γ-ray branching ratios are used to establish the mixing matrix elements and to show that the aligned band has a high value of the K quantum number. The properties of well-defined alignment and yet also high K provide the first clear example of a Fermi-aligned s band. The anomalous decay of the isomer itself is now explained

SHARK-NIR: from K-band to a key instrument, a status update

Science.gov (United States)

Farinato, Jacopo; Bacciotti, Francesca; Baffa, Carlo; Baruffolo, Andrea; Bergomi, Maria; Bongiorno, Angela; Carbonaro, Luca; Carolo, Elena; Carlotti, Alexis; Centrone, Mauro; Close, Laird; De Pascale, Marco; Dima, Marco; D'Orazi, Valentina; Esposito, Simone; Fantinel, Daniela; Farisato, Giancarlo; Gaessler, Wolfgang; Giallongo, Emanuele; Greggio, Davide; Guyon, Olivier; Hinz, Philip; Lisi, Franco; Magrin, Demetrio; Marafatto, Luca; Mohr, Lars; Montoya, Manny; Pedichini, Fernando; Pinna, Enrico; Puglisi, Alfio; Ragazzoni, Roberto; Salasnich, Bernardo; Stangalini, Marco; Vassallo, Daniele; Verinaud, Christophe; Viotto, Valentina

2016-07-01

SHARK-NIR channel is one of the two coronagraphic instruments proposed for the Large Binocular Telescope, in the framework of the call for second generation instruments, issued in 2014. Together with the SHARK-VIS channel, it will offer a few observing modes (direct imaging, coronagraphic imaging and coronagraphic low resolution spectroscopy) covering a wide wavelength domain, going from 0.5μm to 1.7μm. Initially proposed as an instrument covering also the K-band, the current design foresees a camera working from Y to H bands, exploiting in this way the synergy with other LBT instruments such as LBTI, which is actually covering wavelengths greater than L' band, and it will be soon upgraded to work also in K band. SHARK-NIR has been undergoing the conceptual design review at the end of 2015 and it has been approved to proceed to the final design phase, receiving the green light for successive construction and installation at LBT. The current design is significantly more flexible than the previous one, having an additional intermediate pupil plane that will allow the usage of coronagraphic techniques very efficient in term of contrast and vicinity to the star, increasing the instrument coronagraphic performance. The latter is necessary to properly exploit the search of giant exo-planets, which is the main science case and the driver for the technical choices of SHARK-NIR. We also emphasize that the LBT AO SOUL upgrade will further improve the AO performance, making possible to extend the exo-planet search to target fainter than normally achieved by other 8-m class telescopes, and opening in this way to other very interesting scientific scenarios, such as the characterization of AGN and Quasars (normally too faint to be observed) and increasing considerably the sample of disks and jets to be studied. Finally, we emphasize that SHARK-NIR will offer XAO direct imaging capability on a FoV of about 15"x15", and a simple coronagraphic spectroscopic mode offering spectral

Edge instabilities of topological superconductors

Energy Technology Data Exchange (ETDEWEB)

Hofmann, Johannes S. [Institut fuer Theoretische Physik und Astrophysik, Universitaet Wuerzburg (Germany); Max-Planck-Institut fuer Festkoerperforschung, Stuttgart (Germany); Assaad, Fakher F. [Institut fuer Theoretische Physik und Astrophysik, Universitaet Wuerzburg (Germany); Schnyder, Andreas P. [Max-Planck-Institut fuer Festkoerperforschung, Stuttgart (Germany)

2016-07-01

Nodal topological superconductors display zero-energy Majorana flat bands at generic edges. The flatness of these edge bands, which is protected by time-reversal and translation symmetry, gives rise to an extensive ground state degeneracy and a diverging density of states. Therefore, even arbitrarily weak interactions lead to an instability of the flat-band edge states towards time-reversal and translation-symmetry broken phases, which lift the ground-state degeneracy. Here, we employ Monte Carlo simulations combined with mean-field considerations to examine the instabilities of the flat-band edge states of d{sub xy}-wave superconductors. We find that attractive interactions induce a complex s-wave pairing instability together with a density wave instability. Repulsive interactions, on the other hand, lead to ferromagnetism mixed with spin-triplet pairing at the edge. We discuss the implications of our findings for experiments on cuprate high-temperature superconductors.

Observation of Momentum-Confined In-Gap Impurity State in Ba_{0.6}K_{0.4}Fe_{2}As_{2}: Evidence for Antiphase s_{±} Pairing

Directory of Open Access Journals (Sweden)

P. Zhang

2014-07-01

Full Text Available We report the observation by angle-resolved photoemission spectroscopy of an impurity state located inside the superconducting gap of Ba_{0.6}K_{0.4}Fe_{2}As_{2} and vanishing above the superconducting critical temperature, for which the spectral weight is confined in momentum space near the Fermi wave-vector positions. We demonstrate, supported by theoretical simulations, that this in-gap state originates from weak scattering between bands with opposite sign of the superconducting-gap phase. This weak scattering, likely due to off-plane nonmagnetic (Ba, K disorder, occurs mostly among neighboring Fermi surfaces, suggesting that the superconducting-gap phase changes sign within holelike (and electronlike bands. Our results impose severe restrictions on the models promoted to explain high-temperature superconductivity in these materials.

Dual origin of pairing in nuclei

Energy Technology Data Exchange (ETDEWEB)

Idini, A. [University of Jyvaskyla, Department of Physics (Finland); Potel, G. [Michigan State University, National Superconducting Cyclotron Laboratory (United States); Barranco, F. [Escuela Superior de Ingenieros, Universidad de Sevilla, Departamento de Fìsica Aplicada III (Spain); Vigezzi, E., E-mail: enrico.vigezzi@mi.infn.it [INFN Sezione di Milano (Italy); Broglia, R. A. [Università di Milano, Dipartimento di Fisica (Italy)

2016-11-15

The pairing correlations of the nucleus {sup 120}Sn are calculated by solving the Nambu–Gor’kov equations, including medium polarization effects resulting from the interweaving of quasiparticles, spin and density vibrations, taking into account, within the framework of nuclear field theory (NFT), processes leading to self-energy and vertex corrections and to the induced pairing interaction. From these results one can not only demonstrate the inevitability of the dual origin of pairing in nuclei, but also extract information which can be used at profit to quantitatively disentangle the contributions to the pairing gap Δ arising from the bare and from the induced pairing interaction. The first is the strong {sup 1}S{sub 0} short-range NN potential resulting from meson exchange between nucleons moving in time reversal states within an energy range of hundreds of MeV from the Fermi energy. The second results from the exchange of vibrational modes between nucleons moving within few MeV from the Fermi energy. Short- (v{sub p}{sup bare}) and long-range (v{sub p}{sup ind}) pairing interactions contribute essentially equally to nuclear Cooper pair stability. That is to the breaking of gauge invariance in open-shell superfluid nuclei and thus to the order parameter, namely to the ground state expectation value of the pair creation operator. In other words, to the emergent property of generalized rigidity in gauge space, and associated rotational bands and Cooper pair tunneling between members of these bands.

Dual origin of pairing in nuclei

Science.gov (United States)

Idini, A.; Potel, G.; Barranco, F.; Vigezzi, E.; Broglia, R. A.

2016-11-01

The pairing correlations of the nucleus 120Sn are calculated by solving the Nambu-Gor'kov equations, including medium polarization effects resulting from the interweaving of quasiparticles, spin and density vibrations, taking into account, within the framework of nuclear field theory (NFT), processes leading to self-energy and vertex corrections and to the induced pairing interaction. From these results one can not only demonstrate the inevitability of the dual origin of pairing in nuclei, but also extract information which can be used at profit to quantitatively disentangle the contributions to the pairing gap Δ arising from the bare and from the induced pairing interaction. The first is the strong 1 S 0 short-range NN potential resulting from meson exchange between nucleons moving in time reversal states within an energy range of hundreds of MeV from the Fermi energy. The second results from the exchange of vibrational modes between nucleons moving within few MeV from the Fermi energy. Short- ( v p bare) and long-range ( v p ind) pairing interactions contribute essentially equally to nuclear Cooper pair stability. That is to the breaking of gauge invariance in open-shell superfluid nuclei and thus to the order parameter, namely to the ground state expectation value of the pair creation operator. In other words, to the emergent property of generalized rigidity in gauge space, and associated rotational bands and Cooper pair tunneling between members of these bands.

Ionic conductivity and Raman spectra of Na--Li, K--Li, and K--Sn β-Al2O3

International Nuclear Information System (INIS)

Kaneda, T.; Bates, J.B.; Wang, J.C.; Engstrom, H.

1979-01-01

The ionic conductivity and Raman spectra of Na, Na--Li, K, K--Li, and K--Sn β-Al 2 O 3 were measured in order to understand the mechanisms of mixed-ion conduction. It was observed that at 300 0 K, for example, the conductivity of a crystal with composition Na 0 . 82 Li 0 . 18 β-Al 2 O 3 was about one-fifth that of pure Na cyrstals, while the conductivity of K 0 . 80 Li 0 . 20 β-Al 2 O 3 was more than three orders of magnitude lower than that of pure K compounds. The results of a model calculation indicated that the Li + ions are the main carrier species in the Na--Li and K--Li mixed compounds. Features observed in the Raman spectra were attributed to paired- and single-ion vibrations. It is concluded that the K + ions which contribute to a band at 69 cm -1 in K β-Al 2 O 3 are the effective carriers for conduction

Broken toe - self-care

Science.gov (United States)

Fractured toe - self-care; Broken bone - toe - self-care; Fracture - toe - self-care; Fracture phalanx - toe ... often treated without surgery and can be taken care of at home. Severe injuries include: Breaks that ...

A Wide-Band High-Gain Compact SIS Receiver Utilizing a 300-μW SiGe IF LNA

Science.gov (United States)

Montazeri, Shirin; Grimes, Paul K.; Tong, Cheuk-Yu Edward; Bardin, Joseph C.

2017-06-01

Low-power low-noise amplifiers integrated with superconductor-insulator-superconductor (SIS) mixers are required to enable implementation of large-scale focal plane arrays. In this work, a 220-GHz SIS mixer has been integrated with a high-gain broad-band low-power IF amplifier into a compact receiver module. The low noise amplifier (LNA) was specifically designed to match to the SIS output impedance and contributes less than 7 K to the system noise temperature over the 4-8 GHz IF frequency range. A receiver noise temperature of 30-45 K was measured for a local oscillator frequency of 220 GHz over an IF spanning 4-8 GHz. The LNA power dissipation was only 300-μW. To the best of the authors' knowledge, this is the lowest power consumption reported for a high-gain wide-band LNA directly integrated with an SIS mixer.

Systematic study of β-band and correlation with g- band using power law and soft rotor formula

International Nuclear Information System (INIS)

Katoch, Vikas; Kaushik, Reetu; Sharma, S.; Gupta, J.B.

2014-01-01

The nuclear structure of even Z even N medium mass transitional nuclei consist of ground state band, K π =0 1 β-band, K π =2 1 γ- band and other higher bands. As we move away from closed shell, energy levels are low lying from spherical to deformed nuclei and energy deviated from ideal rotor behavior. The energy of these transitional nuclei in ground band can also be studied using Bohr Mottelson energy expression, Soft Rotor Formula (SRF), Power Law (PL) etc. Recently, Gupta et al. (2013) modified SRF for non zero band head K π =2 1 γ-band and reproduced the level energies. Here same formula applied for K π =0 1 β-band and the level energies are reproduced and compared with experimental energies. The power law is also used for recalculation of level energies and for useful comparison

Identifying chiral bands in real nuclei

International Nuclear Information System (INIS)

Shirinda, O.; Lawrie, E.A.

2012-01-01

The application of the presently used fingerprints of chiral bands (originally derived for strongly broken chirality) is investigated for real chiral systems. In particular the chiral fingerprints concerning the B(M1) staggering patterns and the energy staggering are studied. It is found that both fingerprints show considerable changes for real chiral systems, a behaviour that creates a significant risk for misinterpretation of the experimental data and can lead to a failure to identify real chiral systems. (orig.)

Error-correcting pairs for a public-key cryptosystem

International Nuclear Information System (INIS)

Pellikaan, Ruud; Márquez-Corbella, Irene

2017-01-01

Code-based Cryptography (CBC) is a powerful and promising alternative for quantum resistant cryptography. Indeed, together with lattice-based cryptography, multivariate cryptography and hash-based cryptography are the principal available techniques for post-quantum cryptography. CBC was first introduced by McEliece where he designed one of the most efficient Public-Key encryption schemes with exceptionally strong security guarantees and other desirable properties that still resist to attacks based on Quantum Fourier Transform and Amplitude Amplification. The original proposal, which remains unbroken, was based on binary Goppa codes. Later, several families of codes have been proposed in order to reduce the key size. Some of these alternatives have already been broken. One of the main requirements of a code-based cryptosystem is having high performance t -bounded decoding algorithms which is achieved in the case the code has a t -error-correcting pair (ECP). Indeed, those McEliece schemes that use GRS codes, BCH, Goppa and algebraic geometry codes are in fact using an error-correcting pair as a secret key. That is, the security of these Public-Key Cryptosystems is not only based on the inherent intractability of bounded distance decoding but also on the assumption that it is difficult to retrieve efficiently an error-correcting pair. In this paper, the class of codes with a t -ECP is proposed for the McEliece cryptosystem. Moreover, we study the hardness of distinguishing arbitrary codes from those having a t -error correcting pair. (paper)

High accuracy line positions of the ν1 fundamental band of 14N216O

Science.gov (United States)

AlSaif, Bidoor; Lamperti, Marco; Gatti, Davide; Laporta, Paolo; Fermann, Martin; Farooq, Aamir; Lyulin, Oleg; Campargue, Alain; Marangoni, Marco

2018-05-01

The ν1 fundamental band of N2O is examined by a novel spectrometer that relies on the frequency locking of an external-cavity quantum cascade laser around 7.8 μm to a near-infrared Tm:based frequency comb at 1.9 μm. Due to the large tunability, nearly 70 lines in the 1240-1310 cm-1 range of the ν1 band of N2O, from P(40) to R(31), are for the first time measured with an absolute frequency calibration and an uncertainty from 62 to 180 kHz, depending on the line. Accurate values of the spectroscopic constants of the upper state are derived from a fit of the line centers (rms ≈ 4.8 × 10-6 cm-1 or 144 kHz). The ν1 transitions presently measured in a Doppler regime validate high accuracy predictions based on sub-Doppler measurements of the ν3 and ν3-ν1 transitions.

Backbendings of superdeformed bands in 36;40Ar

Science.gov (United States)

Xiang, Xu-Hui; He, Xiao-Tao

2018-05-01

Experimentally observed superdeformed (SD) rotational bands in 36Ar and 40Ar are studied by the cranked shell model (CSM) with the pairing correlations treated by a particle-number-conserving (PNC) method. This is the first time that PNC-CSM calculations have been performed on the light nuclear mass region around A=40. The experimental kinematic moments of inertia J (1) versus rotational frequency are reproduced well. The backbending of the SD band at frequency around ℏω=1.5 MeV in 36Ar is attributed to the sharp rise of the simultaneous alignments of the neutron and proton 1d 5/2[202]5/2 pairs and 1f 7/2[321]3/2 pairs, which is a consequence of the band crossing between the 1d 5/2[202]5/2 and 1f 7/2[321]3/2 configuration states. The gentle upbending at low frequency of the SD band in 40Ar is mainly affected by the alignments of the neutron 1f 7/2[321]3/2 pairs and proton 1d 5/2[202]5/2 pairs. The PNC-CSM calculations show that besides the diagonal parts, the off-diagonal parts of the alignments play an important role in the rotational behavior of the SD bands. Supported by National Natural Science Foundation of China (11775112 and 11275098) and the Priority Academic Program Development of Jiangsu Higher Education Institutions

Real-time intensity based 2D/3D registration using kV-MV image pairs for tumor motion tracking in image guided radiotherapy

Science.gov (United States)

Furtado, H.; Steiner, E.; Stock, M.; Georg, D.; Birkfellner, W.

2014-03-01

Intra-fractional respiratorymotion during radiotherapy is one of themain sources of uncertainty in dose application creating the need to extend themargins of the planning target volume (PTV). Real-time tumormotion tracking by 2D/3D registration using on-board kilo-voltage (kV) imaging can lead to a reduction of the PTV. One limitation of this technique when using one projection image, is the inability to resolve motion along the imaging beam axis. We present a retrospective patient study to investigate the impact of paired portal mega-voltage (MV) and kV images, on registration accuracy. We used data from eighteen patients suffering from non small cell lung cancer undergoing regular treatment at our center. For each patient we acquired a planning CT and sequences of kV and MV images during treatment. Our evaluation consisted of comparing the accuracy of motion tracking in 6 degrees-of-freedom(DOF) using the anterior-posterior (AP) kV sequence or the sequence of kV-MV image pairs. We use graphics processing unit rendering for real-time performance. Motion along cranial-caudal direction could accurately be extracted when using only the kV sequence but in AP direction we obtained large errors. When using kV-MV pairs, the average error was reduced from 3.3 mm to 1.8 mm and the motion along AP was successfully extracted. The mean registration time was of 190+/-35ms. Our evaluation shows that using kVMV image pairs leads to improved motion extraction in 6 DOF. Therefore, this approach is suitable for accurate, real-time tumor motion tracking with a conventional LINAC.

A high efficiency Ku-band radial line relativistic klystron amplifier

Energy Technology Data Exchange (ETDEWEB)

Dang, Fangchao; Zhang, Xiaoping, E-mail: zhangxiaoping@nudt.edu.cn; Zhong, Huihuang; Zhang, Jun; Ju, Jinchuan [College of Optoelectronic Science and Engineering, National University of Defense Technology, Changsha 410073 (China)

2016-07-15

To achieve the gigawatt-level microwave amplification output at Ku-band, a radial-line relativistic klystron amplifier is proposed and investigated in this paper. Different from the annular electron beam in conventional axial relativistic klystron amplifiers, a radial-radiated electron beam is employed in this proposed klystron. Owing to its radially spreading speciality, the electron density and space charge effect are markedly weakened during the propagation in the radial line drift tube. Additionally, the power capacity, especially in the output cavity, is enhanced significantly because of its large volume, which is profitable for the long pulse operation. Particle-in-cell simulation results demonstrate that a high power microwave with the power of 3 GW and the frequency of 14.25 GHz is generated with a 500 kV, 12 kA electron beam excitation and the 30 kW radio-frequency signal injection. The power conversion efficiency is 50%, and the gain is about 50 dB. Meanwhile, there is insignificant electron beam self-excitation in the proposed structure by the adoption of two transverse electromagnetic reflectors. The relative phase difference between the injected signals and output microwaves keeps stable after the amplifier saturates.

Resolution of the 179W isomer anomaly: exposure of a fermi aligned s-band

International Nuclear Information System (INIS)

Walker, P.M.; Surrey Univ., Guildford; Dracoulis, G.D.; Byrne, A.P.; Fabricius, B.; Kibedi, T.; Stuchbery, A.E.

1991-06-01

The K Π = 35/2 - , five quasiparticle isomer in 179 W is shown to decay into the region of a backbend in the 7/2 - [514] band, allowing for the first time the identification of a full set of aligned-band states. Destructive interference results from level-mixing in the band-crossing region. The deduced γ-ray branching ratios are used to establish the mixing matrix elements and to show that the aligned band has a high value of the K-quantum number. The properties of well-defined alignment and yet also high-K, provided the first clear example of a Fermi Aligned s-band. The anomalous decay of the isomer itself is now explained. 11 refs., 1 tab., 3 figs

High voltage K/sub a/-band gyrotron oscillator experiment

International Nuclear Information System (INIS)

Gold, S.H.; Fliflet, A.W.; Manheimer, W.M.; Black, W.M.; Granatstein, V.L.; Kinkead, A.K.; Hardesty, D.L.; Sucy, M.

1986-01-01

Future applications of millimeter-waves may require significantly higher powers (>100 MW) than are available from the long-pulse thermionic gyrotrons that are presently available or under development. Scaling studies suggest that these power levels should be accessible to gyrotrons employing relativistic (0.5-1 MeV), multi-kA electron beams, such as can be generated for short pulse lengths (≤100 nsec) using pulseline accelerators with plasma-induced field-emission cathodes. To explore this potential, the authors have assembled a new gyrotron experiment based on a compact Febetron pulser. Initial experiments using a 350keV, 700A electron beam with a ratio of transverse to longitudinal velocity of ≅0.75 have produced ≅20MW at 35GHz at 8.5% efficiency in a TE/sub 62/ mode, in good agreement with the predictions of theory for the experimental parameters. Substantially higher powers and efficiencies are predicted for a new experimental configuration, which will operate at a higher voltage with improved beam parameters. In this new experiment, a 600 keV, multi-kA electron beam will be produced with low initial transverse energy. Transverse kinetic energy will then be added to the beam either by resonant pumping, via a magnetic wiggler, or by transit through a nonadiabatic magnetic ''bump.'' Finally, the beam will be adiabatically compressed to the desired radius in the gyrotron cavity with a final α≅1. The authors plan to report on the latest results from this new experimental configuration

Wakefield damping in a pair of X-band accelerators for linear colliders

Directory of Open Access Journals (Sweden)

Roger M. Jones

2006-10-01

Full Text Available We consider the means to damp the wakefield left behind ultrarelativistic charges. In particular, we focus on a pair of traveling wave accelerators operating at an X-band frequency of 11.424 GHz. In order to maximize the efficiency of acceleration, in the context of a linear collider, multiple bunches of charged particles are accelerated within a given pulse of the electromagnetic field. The wakefield left behind successive bunches, if left unchecked, can seriously disturb the progress of trailing bunches and can lead to an appreciable dilution in the emittance of the beam. We report on a method to minimize the influence of the wakefield on trailing bunches. This method entails detuning the characteristic mode frequencies which make up the electromagnetic field, damping the wakefield, and interleaving the frequencies of adjacent accelerating structures. Theoretical predictions of the wakefield and modes, based on a circuit model, are compared with experimental measurements of the wakefield conducted within the ASSET facility at SLAC. Very good agreement is obtained between theory and experiment and this allows us to have some confidence in designing the damping of wakefields in a future linear collider consisting of several thousand of these accelerating structures.

Wakefield Damping in a Pair of X-Band Accelerators for Linear Colliders

International Nuclear Information System (INIS)

Jones, R.M.; Adolphsen, C.E.; Wang, J.W.; Li, Z.; SLAC

2006-01-01

We consider means to damp the wake-field left behind ultra-relativistic charges. In particular, we focus on a pair of travelling wave accelerators operating at an X-band frequency of 11.424 GHz. In order to maximize the efficiency of acceleration, in the context of a linear collider, multiple bunches of charged particles are accelerated within a given pulse of the electromagnetic field. The wake-field left behind successive bunches, if left unchecked, can seriously disturb the progress of trailing bunches and can lead to an appreciable dilution in the emittance of the beam. We report on a method to minimize the influence of the wake-field on trailing bunches. This method entails detuning the characteristic mode frequencies which make-up the electromagnetic field, damping the wake-field, and interleaving the frequencies of adjacent accelerating structures. Theoretical predictions of the wake-field and modes, based on a circuit model, are compared with experimental measurements of the wake-field conducted within the ASSET facility at SLAC. Very good agreement is obtained between theory and experiment and this allows us to have some confidence in designing the damping of wake-fields in a future linear collider consisting of several thousand of these accelerating structures

Tuning topological phase transitions in hexagonal photonic lattices made of triangular rods

Science.gov (United States)

Chan, Hsun-Chi; Guo, Guang-Yu

2018-01-01

In this paper we study topological phases in a two-dimensional photonic crystal with broken time (T ) and parity (P ) symmetries by performing calculations of band structures, Berry curvatures, Chern numbers, edge states, and also numerical simulations of light propagation in the edge modes. Specifically, we consider a hexagonal lattice consisting of triangular gyromagnetic rods. Here the gyromagnetic material breaks T symmetry while the triangular rods break P symmetry. Interestingly, we find that the crystal could host quantum anomalous Hall (QAH) phases with different gap Chern numbers (Cg) including | Cg|>1 as well as quantum valley Hall (QVH) phases with contrasting valley Chern numbers (Cv), depending on the orientation of the triangular rods. Furthermore, phase transitions among these topological phases, such as from QAH to QVH and vice versa, can be engineered by a simple rotation of the rods. Our band theoretical analyses reveal that the Dirac nodes at the K and K' valleys in the momentum space are produced and protected by the mirror symmetry (my) instead of the P symmetry, and they become gapped when either T or my symmetry is broken, resulting in a QAH or QVH phase, respectively. Moreover, a high Chern number (Cg=-2 ) QAH phase is generated by gapping triply degenerate nodal points rather than pairs of Dirac points by breaking T symmetry. Our proposed photonic crystal thus provides a platform for investigating intriguing topological phenomena which may be challenging to realize in electronic systems, and also has promising potentials for device applications in photonics such as reflection-free one-way waveguides and topological photonic circuits.

A Longitudianl Study of the Link Between Broken Homes and Criminality.

Science.gov (United States)

McCord, Joan

Possible explanatory theories of the relationship between broken homes and crime include the following: (1) broken homes lead to crimes if there are "catalytic agents"; (2) broken homes lead to crime if these homes fail to provide certain conditions which promote socialization; and (3) broken homes and crime have a common source, but not…

Anisotropic emission of the X-ray K-emission band of nitrogen in hexagonal boron nitride

International Nuclear Information System (INIS)

Tegeler, E.; Kosuch, N.; Wiech, G.; Faessler, A.

1977-05-01

The intensity distribution of the N K-emission band of hexagonal boron nitride samples with partially orientated crystallites was found to be strongly dependent upon the take-off angle of the emitted radiation. The observed emission bands can be separated unambiguously into a sigma- and a π-subband. On the basis of the directional characteristic of radiating dipoles within the layers (sigma-bondings) and perpendicular to the layers (π-bonding) the angular dependence of the intensity of the subbands is quantitatively explained. In addition the degree of orientation of the crystallites on the sample can be determined. The intensity distributions of the emission bands to be expected for single crystals and for samples without any texture are determined; in the latter case the results are found to be in good agreement with experimental results. (orig.) [de

Theory of antiferromagnetic pairing in cuprate superconductors

International Nuclear Information System (INIS)

Plakida, N.M.

2006-01-01

A review of the antiferromagnetic exchange and spin-fluctuation pairing theory in the cuprate superconductors is given. We briefly discuss a phenomenological approach and a theory in the limit of weak Coulomb correlations. A microscopic theory in the strong correlation limit is presented in more detail. In particular, results of our recently developed theory for the effective p-d Hubbard model and the reduced t-J model are given. We have proved that retardation effects for the antiferromagnetic exchange interaction are unimportant that results in pairing of all charge carriers in the conduction band and high Tc proportional to the Fermi energy. The spin-fluctuation interaction caused by kinematic interaction gives an additional contribution to the d-wave pairing. Dependence of Tc on the hole concentration and the lattice constant (or pressure) and an oxygen isotope shift are discussed

Shannon Entropy and K-Means Method for Automatic Diagnosis of Broken Rotor Bars in Induction Motors Using Vibration Signals

Directory of Open Access Journals (Sweden)

David Camarena-Martinez

2016-01-01

Full Text Available For industry, the induction motors are essential elements in production chains. Despite the robustness of induction motors, they are susceptible to failures. The broken rotor bar (BRB fault in induction motors has received special attention since one of its characteristics is that the motor can continue operating with apparent normality; however, at certain point the fault may cause severe damage to the motor. In this work, a methodology to detect BRBs using vibration signals is proposed. The methodology uses the Shannon entropy to quantify the amount of information provided by the vibration signals, which changes due to the presence of new frequency components associated with the fault. For automatic diagnosis, the K-means cluster algorithm and a decision-making unit that looks for the nearest cluster through the Euclidian distance are applied. Unlike other reported works, the proposal can diagnose the BRB condition during startup transient and steady state regimes of operation. Additionally, the proposal is also implemented into a field programmable gate array in order to offer a low-cost and low-complex online monitoring system. The obtained results demonstrate the proposal effectiveness to diagnose half, one, and two BRBs.

Phenomenology of the standard model under conditions of spontaneously broken mirror symmetry

Energy Technology Data Exchange (ETDEWEB)

Dyatlov, I. T., E-mail: dyatlov@thd.pnpi.spb.ru [National Research Center Kurchatov Institute, Petersburg Nuclear Physics Institute (Russian Federation)

2017-03-15

Spontaneously broken mirror symmetry is able to reproduce observed qualitative properties of weak mixing for quark and leptons. Under conditions of broken mirror symmetry, the phenomenology of leptons—that is, small neutrino masses and a mixing character other than that in the case of quarks—requires the Dirac character of the neutrinos and the existence of processes violating the total lepton number. Such processes involve heavy mirror neutrinos; that is, they proceed at very high energies. Here, CP violation implies that a P-even mirror-symmetric Lagrangian must simultaneously be T-odd and, according to the CPT theorem, C-odd. All these properties create preconditions for the occurrence of leptogenesis, which is a mechanism of the emergence of the baryon–lepton asymmetry of the universe in models featuring broken mirror symmetry.

Broken or dislocated jaw

Science.gov (United States)

... broken or dislocated jaw requires prompt medical attention. Emergency symptoms include difficulty breathing or heavy bleeding. ... safety equipment, such as a helmet when playing football, or using ... can prevent or minimize some injuries to the face or jaw.

Effect of hydrogenation on the band gap of graphene nano-flakes

International Nuclear Information System (INIS)

Tachikawa, Hiroto; Iyama, Tetsuji; Kawabata, Hiroshi

2014-01-01

The effects of hydrogenation on the band gap of graphene have been investigated by means of density functional theory method. It is generally considered that the band gap increases with increasing coverage of hydrogen atom on the graphene. However, the present study shows that the band gap decreases first with increasing hydrogen coverage and reaches the lowest value at finite coverage (γ = 0.3). Next, the band gap increases to that of insulator with coverage from 0.3 to 1.0. This specific feature of the band gap is reasonably explained by broken symmetry model and the decrease of pi-conjugation. The electronic states of hydrogenated graphene are discussed. - Highlights: • Density functional theory calculations were carried out for hydrogen on graphene • Effects of hydrogenation on the band gap of graphene were examined. • The band gap showed a minimum at a finite coverage. • Mechanism of specific band gap feature was discussed

Logotherapy Counseling to Improve Acceptance of Broken Home Child

OpenAIRE

Erlangga, Erwin

2017-01-01

This study aims to increase the enrollment of children of a broken home that life has meaning. Subjects are 100 children in Demak whose families experiencing divorce. Research themes include three things: individual counseling, engineering logotherapy, reception, and a child of a broken home. Data obtained based on interviews, observation, and psychological scale showed that of the 100 children of a broken home has a low acceptance that individual counseling with logotherapy techniques were c...

[The species traceability of the ultrafine powder and the cell wall-broken powder of herbal medicine based on DNA barcoding].

Science.gov (United States)

Xiang, Li; Tang, Huan; Cheng, Jin-le; Chen, Yi-long; Deng, Wen; Zheng, Xia-sheng; Lai, Zhi-tian; Chen, Shi-lin

2015-12-01

Ultrafine powder and cell wall-broken powder of herbal medicine lack of the morphological characters and microscopic identification features. This makes it hard to identify herb's authenticity with traditional methods. We tested ITS2 sequence as DNA barcode in identification of herbal medicine in ultrafine powder and cell wall-broken powder in this study. We extracted genomic DNAs of 93 samples of 31 representative herbal medicines (28 species), which include whole plant, roots and bulbs, stems, leaves, flowers, fruits and seeds. The ITS2 sequences were amplified and sequenced bidirectionally. The ITS2 sequences were identified using Basic Local Alignment Search Tool (BLAST) method in the GenBank database and DNA barcoding system to identify the herbal medicine. The genetic distance was analyzed using the Kimura 2-parameter (K2P) model and the Neighbor-joining (NJ) phylogenetic tree was constructed using MEGA 6.0. The results showed that DNA can be extracted successfully from 93 samples and high quality ITS2 sequences can be amplified. All 31 herbal medicines can get correct identification via BLAST method. The ITS2 sequences of raw material medicines, ultrafine powder and cell wall-broken powder have same sequence in 26 herbal medicines, while the ITS2 sequences in other 5 herbal medicines exhibited variation. The maximum intraspecific genetic-distances of each species were all less than the minimum interspecific genetic distances. ITS2 sequences of each species are all converged to their standard DNA barcodes using NJ method. Therefore, using ITS2 barcode can accurately and effectively distinguish ultrafine powder and cell wall-broken powder of herbal medicine. It provides a new molecular method to identify ultrafine powder and cell wall-broken powder of herbal medicine in the quality control and market supervision.

Band anticrossing effects in highly mismatched semiconductor alloys

Energy Technology Data Exchange (ETDEWEB)

Wu, Junqiao [Univ. of California, Berkeley, CA (United States)

2002-01-01

The first five chapters of this thesis focus on studies of band anticrossing (BAC) effects in highly electronegativity- mismatched semiconductor alloys. The concept of bandgap bowing has been used to describe the deviation of the alloy bandgap from a linear interpolation. Bowing parameters as large as 2.5 eV (for ZnSTe) and close to zero (for AlGaAs and ZnSSe) have been observed experimentally. Recent advances in thin film deposition techniques have allowed the growth of semiconductor alloys composed of significantly different constituents with ever- improving crystalline quality (e.g., GaAs_1-xN_x and GaP_1-xN_x with x ~< 0.05). These alloys exhibit many novel and interesting properties including, in particular, a giant bandgap bowing (bowing parameters > 14 eV). A band anticrossing model has been developed to explain these properties. The model shows that the predominant bowing mechanism in these systems is driven by the anticrossing interaction between the localized level associated with the minority component and the band states of the host. In this thesis I discuss my studies of the BAC effects in these highly mismatched semiconductors. It will be shown that the results of the physically intuitive BAC model can be derived from the Hamiltonian of the many-impurity Anderson model. The band restructuring caused by the BAC interaction is responsible for a series of experimental observations such as a large bandgap reduction, an enhancement of the electron effective mass, and a decrease in the pressure coefficient of the fundamental gap energy. Results of further experimental investigations of the optical properties of quantum wells based on these materials will be also presented. It will be shown that the BAC interaction occurs not only between localized states and conduction band states at the Brillouin zone center, but also exists over all of k-space. Finally, taking ZnSTe and ZnSeTe as examples, I show that BAC also

Migration of a Broken Kirschner Wire after Surgical Treatment of Acromioclavicular Joint Dislocation

Directory of Open Access Journals (Sweden)

Sabri Batın

2016-01-01

Full Text Available Kirschner wire (K-wire is one of the commonly used implants in orthopaedics practice. Migration of the wire is one of the most frequently reported complications after fixation by the K-wire. In particular, it has been reported that a greater range of motion in the shoulder, negative intrathoracic pressure associated with respiration, gravitational force, and muscular activities may cause migration from the upper extremities. In general, thin and long foreign bodies with smooth surfaces that are localized within the tendon sheath and at an upper extremity can migrate more readily and can reach longer distances. Here, we present a patient with long-term migration of a broken K-wire who underwent fixation for acromioclavicular joint dislocation 5 years ago.

Improving mental task classification by adding high frequency band information.

Science.gov (United States)

Zhang, Li; He, Wei; He, Chuanhong; Wang, Ping

2010-02-01

Features extracted from delta, theta, alpha, beta and gamma bands spanning low frequency range are commonly used to classify scalp-recorded electroencephalogram (EEG) for designing brain-computer interface (BCI) and higher frequencies are often neglected as noise. In this paper, we implemented an experimental validation to demonstrate that high frequency components could provide helpful information for improving the performance of the mental task based BCI. Electromyography (EMG) and electrooculography (EOG) artifacts were removed by using blind source separation (BSS) techniques. Frequency band powers and asymmetry ratios from the high frequency band (40-100 Hz) together with those from the lower frequency bands were used to represent EEG features. Finally, Fisher discriminant analysis (FDA) combining with Mahalanobis distance were used as the classifier. In this study, four types of classifications were performed using EEG signals recorded from four subjects during five mental tasks. We obtained significantly higher classification accuracy by adding the high frequency band features compared to using the low frequency bands alone, which demonstrated that the information in high frequency components from scalp-recorded EEG is valuable for the mental task based BCI.

Emergent nanoscale fluctuations in high rock-salt PbTe

Science.gov (United States)

Billinge, Simon

2013-03-01

Lead Telluride is one of the most promising thermoelectric materials in the temperature range just above room temperature. It is a narrow band gap semiconductor with a high Seebeck coefficient and a low thermal conductivity. It is structurally much simpler than many other leading candidates for high performance thermoelectrics being a binary rock-salt, isostructural to NaCl. The thermoelectric figure of merit, ZT, can be markedly improved by alloying with various other elements by forming quenched nanostructures. The undoped endmember, PbTe, does not have any such quenched nanostructure, yet has a rather low intrinsic thermal conductivity. There are also a number of interesting and non-canonical behaviors that it exhibits, such as an increasing measured band-gap with increasing temperature, exactly opposite to what is normally seen due to Fermi smearing of the band edge, and an unexpected non-monotonicity of the band gap in the series PbTe - PbSe - PbS. The material is on the surface simple, but hides some interesting complexity. We have investigated in detail the PbTe endmember using x-ray and neutron diffraction and neutron inelastic scattering. To our surprise, using the atomic pair distribution function (PDF) analysis of neutron powder diffraction data we found that an interesting and non-trivial local structure that appears on warming. with the Pb atoms moving off the high-symmetry rock-salt positions towards neighboring Te ions. No evidence for the off-centering of the Pb atoms is seen at low temperature. The crossover from the locally undistorted to the locally distorted state occurs on warming between 100 K and 250 K. This unexpected emergence of local symmetry broken distortions from an undistorted ground-state we have called emphanisis, from the Greek for appearing from nothing. We have also investigated the lattice dynamics of the system to search for a dynamical signature of this behavior and extended the studies to doped systems and I will also

Staggering in signature partners of A∼190 mass region of superdeformed rotational bands

International Nuclear Information System (INIS)

Uma, V.S.; Goel, Alpana; Yadav, Archana

2014-01-01

This paper discuss about ΔI=1 signature splitting in signature partner pairs of A∼190 mass region. Around twenty signature partner pairs (usually called as two bands, each with a fixed signature) have been reported in this mass region. For these signature pairs, band head moment of inertia (J 0 ) and intrinsic structure of each pair of signature partners have been found as almost identical. Also, these signature partner pairs showed large amplitude signature splitting. As each of the two signature partner forms a regular spin sequence and signature bands are not equivalent in terms of energies. This difference in energies results in signature splitting

High accuracy line positions of the ν 1 fundamental band of 14 N 2 16 O

KAUST Repository

Alsaif, Bidoor

2018-03-08

The ν1 fundamental band of N2O is examined by a novel spectrometer that relies on the frequency locking of an external-cavity quantum cascade laser around 7.8 μm to a near-infrared Tm:based frequency comb at 1.9 μm. Due to the large tunability, nearly 70 lines in the 1240 – 1310 cm−1 range of the ν1 band of N2O, from P(40) to R(31), are for the first time measured with an absolute frequency calibration and an uncertainty from 62 to 180 kHz, depending on the line. Accurate values of the spectroscopic constants of the upper state are derived from a fit of the line centers (rms ≈ 4.8 × 10−6 cm−1 or 144 kHz). The ν1 transitions presently measured in a Doppler regime validate high accuracy predictions based on sub-Doppler measurements of the ν3 and ν3-ν1 transitions.

Ultra-High Gradient S-band Linac for Laboratory and Industrial Applications

Science.gov (United States)

Faillace, L.; Agustsson, R.; Dolgashev, V.; Frigola, P.; Murokh, A.; Rosenzweig, J.; Yakimenko, V.

2010-11-01

A strong demand for high gradient structures arises from the limited real estate available for linear accelerators. RadiaBeam Technologies is developing a Doubled Energy Compact Accelerator (DECA) structure: an S-band standing wave electron linac designed to operate at accelerating gradients of up to 50 MV/m. In this paper, we present the radio-frequency design of the DECA S-band accelerating structure, operating at 2.856 GHz in the π-mode. The structure design is heavily influenced by NLC collaboration experience with ultra high gradient X-band structures; S-band, however, is chosen to take advantage of commonly available high power S-band klystrons.

Cooper pairs' magnetic moment in MCFL color superconductivity

International Nuclear Information System (INIS)

Feng Bo; Ferrer, Efrain J.; Incera, Vivian de la

2011-01-01

We investigate the effect of the alignment of the magnetic moments of Cooper pairs of charged quarks that form at high density in three-flavor quark matter. The high-density phase of this matter in the presence of a magnetic field is known to be the Magnetic Color-Flavor-Locked (MCFL) phase of color superconductivity. We derive the Fierz identities of the theory and show how the explicit breaking of the rotational symmetry by the uniform magnetic field opens new channels of interactions and allows the formation of a new diquark condensate. The new order parameter is a spin-1 condensate proportional to the component in the field direction of the average magnetic moment of the pairs of charged quarks. The magnitude of the spin-1 condensate becomes comparable to the larger of the two scalar gaps in the region of large fields. The existence of the spin-1 condensate is unavoidable, as in the presence of a magnetic field there is no solution of the gap equations with nonzero scalar gaps and zero magnetic moment condensate. This is consistent with the fact that the extra condensate does not break any symmetry that has not already been broken by the known MCFL gaps. The spin-1 condensate enhances the condensation energy of pairs formed by charged quarks and the magnetization of the system. We discuss the possible consequences of the new order parameter on the issue of the chromomagnetic instability that appears in color superconductivity at moderate density.

Enhanced stability of bound pairs at nonzero lattice momenta

International Nuclear Information System (INIS)

Kornilovitch, Pavel

2004-01-01

A two-body problem on the square lattice is analyzed. The interaction potential consists of strong on-site repulsion and nearest-neighbor attraction. The exact pairing conditions are derived for s-, p-, and d-symmetric bound states. The pairing conditions are strong functions of the total pair momentum K. It is found that the stability of pairs increases with K. At weak attraction, the pairs do not form at the Γ point but stabilize at lattice momenta close to the Brillouin zone boundary. The phase boundaries in the momentum space, which separate stable and unstable pairs, are calculated. It is found that the pairs are formed easier along the (π,0) direction than along the (π,π) direction. This might lead to the appearance of 'hot pairing spots' on the K x and K y axes

Warm-Up Activities of Middle and High School Band Directors Participating in State-Level Concert Band Assessments

Science.gov (United States)

Ward, Justin P.; Hancock, Carl B.

2016-01-01

The purpose of this study was to examine the warm-ups chosen by concert band directors participating in state-level performance assessments. We observed 29 middle and high school bands and coded the frequency and duration of warm-up activities and behaviors. Results indicated that most bands rehearsed music and played scales, long tones, and…

S-band 300 W pulsed solid state microwave amplifier development for driving high power klystrons for electron accelerators

International Nuclear Information System (INIS)

Mohania, Praveen; Shrivastava, Purushottam; Hannurkar, P.R.

2005-01-01

S-Band Microwave electron accelerators like microtrons and linear accelerators need pulsed microwaves from few megawatts to tens of megawatts to accelerator the electrons to desired energy and intensity. Klystron tube based driver amplifiers were used to drive the high power klystrons, which need microwave power from few tens of watts to 1 kW depending on tube output power and gain. A endeavour was initiated at Centre for Advanced Technology to develop state of art solid state S-band microwave amplifiers indigenously to drive the klystron tubes. A modular design approach was used and individual modules up to 160 W power levels were developed and tested. Finally combining 160 W modules will give up to 300 W output power. Several more modules can be combined to achieve even high power levels. Present paper describes the developmental efforts of 300 W S-band solid-state amplifiers and related microwave technologies. (author)

Test plan for surface and subsurface examinations of K-east and K-west fuel elements

International Nuclear Information System (INIS)

Pitner, A.L.

1997-01-01

The test plan for subsurface examinations on damaged K East and K West Basin fuel elements is presented. The purpose of these examinations is to inspect damaged areas on the fuel elements for the presence of voids, sludge, or broken fuel, and to obtain samples from the damaged areas for subsequent characterization tests

Hadronic production of massive lepton pairs

International Nuclear Information System (INIS)

Berger, E.L.

1982-12-01

A review is presented of recent experimental and theoretical progress in studies of the production of massive lepton pairs in hadronic collisions. I begin with the classical Drell-Yan annihilation model and its predictions. Subsequently, I discuss deviations from scaling, the status of the proofs of factorization in the parton model, higher-order terms in the perturbative QCD expansion, the discrepancy between measured and predicted yields (K factor), high-twist terms, soft gluon effects, transverse-momentum distributions, implications for weak vector boson (W +- and Z 0 ) yields and production properties, nuclear A dependence effects, correlations of the lepton pair with hadrons in the final state, and angular distributions in the lepton-pair rest frame

Interface Study on Amorphous Indium Gallium Zinc Oxide Thin Film Transistors Using High-k Gate Dielectric Materials

Directory of Open Access Journals (Sweden)

Yu-Hsien Lin

2015-01-01

Full Text Available We investigated amorphous indium gallium zinc oxide (a-IGZO thin film transistors (TFTs using different high-k gate dielectric materials such as silicon nitride (Si3N4 and aluminum oxide (Al2O3 at low temperature process (<300°C and compared them with low temperature silicon dioxide (SiO2. The IGZO device with high-k gate dielectric material will expect to get high gate capacitance density to induce large amount of channel carrier and generate the higher drive current. In addition, for the integrating process of integrating IGZO device, postannealing treatment is an essential process for completing the process. The chemical reaction of the high-k/IGZO interface due to heat formation in high-k/IGZO materials results in reliability issue. We also used the voltage stress for testing the reliability for the device with different high-k gate dielectric materials and explained the interface effect by charge band diagram.

The proterozoic Georgetown Province - a Broken Hill analogue

International Nuclear Information System (INIS)

Carr, G.R.

2000-01-01

Collaborative work between CSIRO and AGSO has resulted in the development of a Pb isotope model that attempts to place relatively precise (∼5 Ma) age constraints on Proterozoic mineralisation in the Mount Isa and McArthur River terrains (Sun et al., 1994). Although this model was developed for sediment hosted mineralisation in low grade metamorphic terrains, the CSIRO-AGSO model ages for other mineralisation in high-grade terrains such as Broken Hill appear to be consistent with the U-Pb zircon ages obtained for the high-grade host sequences. Without independent evidence that the model is applicable to such terrains, the observations cannot be used to indicate the age of the mineralisation. Lead isotope data obtained on potassium feldspar separates from five felsic intrusive samples in the Georgetown terrain show a wide range of Pb isotope ratios. The lowest 206 Pb/ 204 Pb analyses are considered to approximate to the Proterozoic initial ratio and indicate a model age of ∼1510 Ma based on the CSIRO-AGSO model. This age is 45 Ma younger than the crystallisation age of the granite, but must be considered a minimum as the initial 206 Pb/ 204 Pb ratio may well prove to be lower after more comprehensive analysis. Sulfide mineralisation within the Einasleigh Metamorphics has a wide range of 206 Pb/ 204 Pb ratios that lie between this granite value and the relatively homogeneous population from Railway Flat. The Railway Flat data are very similar to values for Broken Hill and also the Broken Hill-type Pegmont mineralisation in the Mount Isa Eastern Succession. These data all have significantly lower 207 Pb/ 204 Pb ratios than the CSIRO-AGSO model, suggesting a significantly different source rock environment for this style of mineralisation from that for the sediment hosted deposits

Broken rice kernels and the kinetics of rice hydration and texture during cooking.

Science.gov (United States)

Saleh, Mohammed; Meullenet, Jean-Francois

2013-05-01

During rice milling and processing, broken kernels are inevitably present, although to date it has been unclear as to how the presence of broken kernels affects rice hydration and cooked rice texture. Therefore, this work intended to study the effect of broken kernels in a rice sample on rice hydration and texture during cooking. Two medium-grain and two long-grain rice cultivars were harvested, dried and milled, and the broken kernels were separated from unbroken kernels. Broken rice kernels were subsequently combined with unbroken rice kernels forming treatments of 0, 40, 150, 350 or 1000 g kg(-1) broken kernels ratio. Rice samples were then cooked and the moisture content of the cooked rice, the moisture uptake rate, and rice hardness and stickiness were measured. As the amount of broken rice kernels increased, rice sample texture became increasingly softer (P hardness was negatively correlated to the percentage of broken kernels in rice samples. Differences in the proportions of broken rice in a milled rice sample play a major role in determining the texture properties of cooked rice. Variations in the moisture migration kinetics between broken and unbroken kernels caused faster hydration of the cores of broken rice kernels, with greater starch leach-out during cooking affecting the texture of the cooked rice. The texture of cooked rice can be controlled, to some extent, by varying the proportion of broken kernels in milled rice. © 2012 Society of Chemical Industry.

An effective 2-band eg model of sulfur hydride H3S for high-Tc superconductivity

Science.gov (United States)

Nishiguchi, Kazutaka; Teranishi, Shingo; Miyao, Satoaki; Matsushita, Goh; Kusakabe, Koichi

To understand high transition temperature (Tc) superconductivity in sulfur hydride H3S, we propose an effective 2-band model having the eg symmetry as the minimal model for H3S. Two eg orbitals centered on a sulfur S atom are chosen for the smallest representation of relevant bands with the van-Hove singularity around the Fermi levels except for the Γ-centered small hole pockets by the sulfur 3 p orbitals. By using the maximally localized Wannier functions, we derive the minimal effective model preserving the body-centered cubic (bcc) crystal symmetry of the H3S phase having the highest Tc ( 203 K under pressures) among the other polymorphs of H3S.

Broken SU(4) symmetry and new resonance

International Nuclear Information System (INIS)

Ueda, Y.

1975-11-01

Weinberg's spectral function sum rules are modified to accommodate broken symmetry effects of SU(4). With a simple choice of the symmetry-breaking term, the spectral function sum rules yield the observed vector meson mass spectrum as well as sum rules for the e - e + decay rates of vector mesons. In particular, a new mass formula, which can be interpreted as the broken symmetry version of the Schwinger formula, is derived, the agreement with experiments is excellent. (Ueda, Y.)

The case for spin-fluctuation induced pairing in Ba{sub 1-x}K{sub x}Fe{sub 2}As{sub 2}

Energy Technology Data Exchange (ETDEWEB)

Boehm, Thomas U.

2017-03-07

The microscopic mechanism and the experimental identification of unconventional superconductivity is one of the most vexing problems of contemporary condensed matter physics. Raman spectroscopy provides a new avenue for this quest by accessing the hierarchy of superconducting pairing propensities. The doping-dependent study of competing pairing channels in Ba{sub 1-x}K{sub x}Fe{sub 2}As{sub 2} for 0.22 ≤ x ≤ 0.70 is one of the main aspects of this thesis. The observations demonstrate the importance of spin fluctuations for Cooper pairing.

Engineering the propagation of high-k bulk plasmonic waves in multilayer hyperbolic metamaterials by multiscale structuring

DEFF Research Database (Denmark)

Zhukovsky, Sergei; Lavrinenko, Andrei; Sipe, J. E.

2013-01-01

, wavelength scale, the propagation of bulk plasmon polaritons in the resulting multiscale HMM is subject to photonic band gap phenomena. A great degree of control over such plasmons can be exerted by varying the superstructure geometry. As an example, Bragg reflection and Fabry-Pérot resonances...... are demonstrated in multiscale HMMs with periodic superstructures. More complicated, aperiodically ordered superstructures are also considered, with fractal Cantor-like multiscale HMMs exhibiting characteristic self-similar spectral signatures in the high-k band. The multiscale HMM concept is shown...

Two-phase flow phenomena in broken recirculation line of BWR

International Nuclear Information System (INIS)

Kato, Masami; Arai, Kenji; Narabayashi, Tadashi; Amano, Osamu.

1986-01-01

When a primary recirculation line of BWR is ruptured, a primary recirculation pump may be subjected to very high velocity two-phase flow and its speed may be accelerated by this flow. It is important for safety evaluation to estimate the pump behavior during blowdown. There are two problems involved in analyzing this behavior. One problem concerns the pump characteristics under two-phase flow. The other involves the two-phase conditions at the pump inlet. If the rupture occurs at a suction side of the pump, choking is considered to occur at a broken jet pump nozzle. Then, a void fraction becomes larger downstream from the jet pump nozzle and volumetric flow through the pump will be very high. However, there is little experimental data available on two-phase flow downstream from a choking plane. Blowdown tests were performed using a simulated broken recirculation line and measured data were analyzed by TRAC-PlA. Analytical results agreed with measured data. (author)

High macro rubber band ligature

Directory of Open Access Journals (Sweden)

José A. Reis Neto

2013-07-01

Full Text Available Purpose: The goal of a rubber band ligature is to promote fibrosis of the submucosa with subsequent fixation of the anal epithelium to the underlying sphincter. Following this principle, a new technique of ligature was developed based on two aspects: 1. macro banding: to have a better fibrosis and fixation by banding a bigger volume of mucosa and 2. higher ligature: to have this fixation at the origin of the hemorrhoidal cushion displacement. Methods: 1634 patients with internal hemorrhoidal disease grade II or III were treated by the technique called high macro rubber band. There was no distinction as to age, gender or race. To perform this technique a new hemorrhoidal device was specially designed with a larger diameter and a bigger capacity for mucosal volume aspiration. It is recommended to utilize a longer and wider anoscope to obtain a better view of the anal canal, which will facilitate the injection of submucosa higher in the anal canal and the insertion of the rubber band device. The hemorrhoidal cushion must be banded higher in the anal canal (4 cm above the pectinate line. It is preferable to treat all the hemorrhoids in one single session (maximum of three areas banded. Results: The analysis was retrospective without any comparison with conventional banding. The period of evaluation extended from one to twelve years. The analysis of the results showed perianal edema in 1.6% of the patients, immediate tenesmus in 0.8%, intense pain (need for parenteral analgesia in 1.6%, urinary retention in 0.1% of the patients and a symptomatic recurrence rate of 4.2%. All patients with symptomatic recurrence were treated with a new session of macro rubber banding. None of the patients developed anal or rectal sepsis. Small post-ligature bleeding was observed only in 0.8% of the patients. Conclusions: The high macro rubber banding technique represents an alternative method for the treatment of hemorrhoidal disease grades II or III, with good

Existence and consequences of Coulomb pairing of electrons in a solid

International Nuclear Information System (INIS)

Mahajan, S.M.; Thyagaraja, A.

1996-11-01

It is shown from first principles that, in the periodic potential of a crystalline solid, short-range (i.e., screened) binary Coulomb interactions can lead to a two-electron bound state. It is further suggested that these composite bosonic states (charge -2e, and typically spin zero) could mediate an effectively attractive interaction between pairs of conduction electrons close to the Fermi level. This necessarily short range attractive interaction, which is crucially dependent on the band structure of the solid, and is complementary to the phonon-mediated one, may provide a source for the existence and properties of short correlation-length electron pairs (analogous to but distinct from Cooper pairs) needed to understand high temperature superconductivity. Several distinctive and observable characteristics of the proposed pairing scheme are discussed

Chromosome Banding in Amphibia. XXXII. The Genus Xenopus (Anura, Pipidae).

Science.gov (United States)

Schmid, Michael; Steinlein, Claus

2015-01-01

Mitotic chromosomes of 16 species of the frog genus Xenopus were prepared from kidney and lung cell cultures. In the chromosomes of 7 species, high-resolution replication banding patterns could be induced by treating the cultures with 5-bromodeoxyuridine (BrdU) and deoxythymidine (dT) in succession, and in 6 of these species the BrdU/dT-banded chromosomes could be arranged into karyotypes. In the 3 species of the clade with 2n = 20 and 4n = 40 chromosomes (X. tropicalis, X. epitropicalis, X. new tetraploid 1), as well as in the 3 species with 4n = 36 chromosomes (X. laevis, X. borealis, X. muelleri), the BrdU/dT-banded karyotypes show a high degree of homoeology, though differences were detected between these groups. Translocations, inversions, insertions or sex-specific replication bands were not observed. Minor replication asynchronies found between chromosomes probably involve heterochromatic regions. BrdU/dT replication banding of Xenopus chromosomes provides the landmarks necessary for the exact physical mapping of genes and repetitive sequences. FISH with an X. laevis 5S rDNA probe detected multiple hybridization sites at or near the long-arm telomeric regions in most chromosomes of X. laevis and X. borealis, whereas in X. muelleri, the 5S rDNA sequences are located exclusively at the long-arm telomeres of a single chromosome pair. Staining with the AT base pair-specific fluorochrome quinacrine mustard revealed brightly fluorescing heterochromatic regions in the majority of X. borealis chromosomes which are absent in other Xenopus species.

Broken symmetries at high temperatures and the problem of baryon excess of the universe

CERN Document Server

Mohapatra, Rabindra N

1979-01-01

We discuss a class of gauge theories, where spontan- eously broken symmetries, instead of being restored, persist as the temperature is increased. Applying these ideas to the specific case of the soft CP- viola tion in grand unified theories, we discuss a mechanism to generate the baryon to entropy ratio of the universe.

On the combination of the Cooper pair and the Ogg pair in the high-Tc oxide superconductor

International Nuclear Information System (INIS)

Zhang Liyuan.

1991-08-01

In this paper it is argued that the superconductivity of the high-T c oxide superconductor (HTOS) can be explained by the combinating mechanism of the Cooper pair and the Ogg pair. The properties of the superconducting state of the HTOS have been calculated under this mechanism, and the theoretical results are overall consistent with the experiment. (author). 37 refs

Band-edge photoluminescence in CdTe

International Nuclear Information System (INIS)

Horodysky, P.; Grill, R.; Hlidek, P.

2006-01-01

Near band-gap photoluminescence (PL) and absorption of bulk crystals of CdTe were measured over a wide range of temperatures (4-500 K). It is demonstrated that the high-temperature (above 150 K) PL intensity correlates with a lower quality of the samples and quasiparticle localization induced by the crystal potential fluctuations. The influence of the high absorption coefficient at the free-exciton resonance energy on the PL spectra is analytically studied by solving the diffusion-recombination equation. We show that the reabsorption of the radiation by the free-exciton states creates two illusory PL maxima. No dead surface layer is needed to explain reabsorption effects. The room-temperature PL maximum matches neither the free-exciton resonance nor the band-gap energy. The high temperature PL is explained by the recombination of electrons and holes localized on potential fluctuations. (copyright 2006 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

Parametric conversion and maximally entangled photon pair via collective excitations in a cycle atomic ensemble

International Nuclear Information System (INIS)

Li, J.; Yu, R.; Yang, X.

2008-01-01

We study the propagation of two quantized optical fields via considering the collective effects of photonic emissions and excitations of a three-level cyclic-type system (such as atomic ensemble with symmetry broken, or the chiral molecular gases, or manual 'atomic' array with symmetry broken), where the quantum transitions is driven by two quantized fields and a classical one. The results show that the parametric conversion and maximally entangled photon pair generation can be achieved by means of the collective excitation of the two upper energy levels induced by the classic optical field. This investigation may be used for the generated coherent short-wavelength quantum radiation and quantum information processing

Exchange and spin-fluctuation superconducting pairing in the strong correlation limit of the Hubbard model

International Nuclear Information System (INIS)

Plakida, N. M.; Anton, L.; Adam, S. . Department of Theoretical Physics, Horia Hulubei National Institute for Physics and Nuclear Engineering, PO Box MG-6, RO-76900 Bucharest - Magurele; RO); Adam, Gh. . Department of Theoretical Physics, Horia Hulubei National Institute for Physics and Nuclear Engineering, PO Box MG-6, RO-76900 Bucharest - Magurele; RO)

2001-01-01

A microscopical theory of superconductivity in the two-band singlet-hole Hubbard model, in the strong coupling limit in a paramagnetic state, is developed. The model Hamiltonian is obtained by projecting the p-d model to an asymmetric Hubbard model with the lower Hubbard subband occupied by one-hole Cu d-like states and the upper Hubbard subband occupied by two-hole p-d singlet states. The model requires two microscopical parameters only, the p-d hybridization parameter t and the charge-transfer gap Δ. It was previously shown to secure an appropriate description of the normal state properties of the high -T c cuprates. To treat rigorously the strong correlations, the Hubbard operator technique within the projection method for the Green function is used. The Dyson equation is derived. In the molecular field approximation, d-wave superconducting pairing of conventional hole (electron) pairs in one Hubbard subband is found, which is mediated by the exchange interaction given by the interband hopping, J ij = 4 (t ij ) 2 / Δ. The normal and anomalous components of the self-energy matrix are calculated in the self-consistent Born approximation for the electron-spin-fluctuation scattering mediated by kinematic interaction of the second order of the intraband hopping. The derived numerical and analytical solutions predict the occurrence of singlet d x 2 -y 2 -wave pairing both in the d-hole and singlet Hubbard subbands. The gap functions and T c are calculated for different hole concentrations. The exchange interaction is shown to be the most important pairing interaction in the Hubbard model in the strong correlation limit, while the spin-fluctuation coupling results only in a moderate enhancement of T c . The smaller weight of the latter comes from two specific features: its vanishing inside the Brillouin zone (BZ) along the lines, |k x | + |k y |=π pointing towards the hot spots and the existence of a small energy shell within which the pairing is effective. By

Production of supersymmetric pairs at antipp colliders

International Nuclear Information System (INIS)

Peschanski, R.

1985-02-01

Production and decay rates of squarks and gluinos at antipp colliders are shown to depend not only on the mass scale but on the ratio of squark to gluino mass. In the degenerate case which is shown to be natural in a large class of broken Supergravity models with minimal field content the predicted cross-sections are enhanced by a sizeable factor. This gives an improved bound on the squark mass (70 GeV) from the analysis of Cern monojets and indications for the search of squark decay modes of supersymmetric pairs at antipp colliders in the near future

Strong band edge luminescence from InN films grown on Si substrates by electron cyclotron resonance-assisted molecular beam epitaxy

International Nuclear Information System (INIS)

Yodo, Tokuo; Yona, Hiroaki; Ando, Hironori; Nosei, Daiki; Harada, Yoshiyuki

2002-01-01

We observed strong band edge luminescence at 8.5-200 K from 200-880 nm thick InN films grown on 10 nm thick InN buffer layers on Si(001) and Si(111) substrates by electron cyclotron resonance-assisted molecular beam epitaxy. The InN film on the Si(001) substrate exhibited strong band edge photoluminescence (PL) emission at 1.814 eV at 8.5 K, tentatively assigned as donor to acceptor pair [DAP (α-InN)] emission from wurtzite-InN (α-InN) crystal grains, while those on Si(111) showed other stronger band edge PL emissions at 1.880, 2.081 and 2.156 eV, tentatively assigned as donor bound exciton [D 0 X(α-InN)] from α-InN grains, DAP (β-InN) and D 0 X (β-InN) emissions from zinc blende-InN (β-InN) grains, respectively

What is Broken Heart Syndrome

Science.gov (United States)

... pumping action and blood flow, go to the Health Topics How the Heart Works article.) Researchers are trying to identify the precise way in which the stress hormones affect the heart. Broken heart syndrome may result from ...

Intrinsic properties of high-spin band structures in triaxial nuclei

Science.gov (United States)

Jehangir, S.; Bhat, G. H.; Sheikh, J. A.; Palit, R.; Ganai, P. A.

2017-12-01

The band structures of 68,70Ge, 128,130,132,134Ce and 132,134,136,138Nd are investigated using the triaxial projected shell model (TPSM) approach. These nuclei depict forking of the ground-state band into several s-bands and in some cases, both the lowest two observed s-bands depict neutron or proton character. It was discussed in our earlier work that this anomalous behaviour can be explained by considering γ-bands based on two-quasiparticle configurations. As the parent band and the γ-band built on it have the same intrinsic structure, g-factors of the two bands are expected to be similar. In the present work, we have undertaken a detailed investigation of g-factors for the excited band structures of the studied nuclei and the available data for a few high-spin states are shown to be in fair agreement with the predicted values.

High Level Rule Modeling Language for Airline Crew Pairing

Science.gov (United States)

Mutlu, Erdal; Birbil, Ş. Ilker; Bülbül, Kerem; Yenigün, Hüsnü

2011-09-01

The crew pairing problem is an airline optimization problem where a set of least costly pairings (consecutive flights to be flown by a single crew) that covers every flight in a given flight network is sought. A pairing is defined by using a very complex set of feasibility rules imposed by international and national regulatory agencies, and also by the airline itself. The cost of a pairing is also defined by using complicated rules. When an optimization engine generates a sequence of flights from a given flight network, it has to check all these feasibility rules to ensure whether the sequence forms a valid pairing. Likewise, the engine needs to calculate the cost of the pairing by using certain rules. However, the rules used for checking the feasibility and calculating the costs are usually not static. Furthermore, the airline companies carry out what-if-type analyses through testing several alternate scenarios in each planning period. Therefore, embedding the implementation of feasibility checking and cost calculation rules into the source code of the optimization engine is not a practical approach. In this work, a high level language called ARUS is introduced for describing the feasibility and cost calculation rules. A compiler for ARUS is also implemented in this work to generate a dynamic link library to be used by crew pairing optimization engines.

Broken homes, parental psychiatric illness, and female delinquency.

Science.gov (United States)

Offord, David R; Abrams, Nola; Allen, Nancy; Poushinsky, Mary

1979-04-01

Fifty-nine families with delinquent daughters were compared with 59 families, matched on socioeconomic class, with daughters of the same age who were not delinquent. The frequency of broken homes was found to be the strongest distinguishing factor between probands and controls. Parental disabilities appeared to play a part in the incidence of delinquency among girls, particularly when the disabilities result in a broken home.

High-temperature superconductivity from fine-tuning of Fermi-surface singularities in iron oxypnictides

Science.gov (United States)

Charnukha, A.; Evtushinsky, D. V.; Matt, C. E.; Xu, N.; Shi, M.; Büchner, B.; Zhigadlo, N. D.; Batlogg, B.; Borisenko, S. V.

2015-12-01

In the family of the iron-based superconductors, the REFeAsO-type compounds (with RE being a rare-earth metal) exhibit the highest bulk superconducting transition temperatures (Tc) up to 55 K and thus hold the key to the elusive pairing mechanism. Recently, it has been demonstrated that the intrinsic electronic structure of SmFe0.92Co0.08AsO (Tc = 18 K) is highly nontrivial and consists of multiple band-edge singularities in close proximity to the Fermi level. However, it remains unclear whether these singularities are generic to the REFeAsO-type materials and if so, whether their exact topology is responsible for the aforementioned record Tc. In this work, we use angle-resolved photoemission spectroscopy (ARPES) to investigate the inherent electronic structure of the NdFeAsO0.6F0.4 compound with a twice higher Tc = 38 K. We find a similarly singular Fermi surface and further demonstrate that the dramatic enhancement of superconductivity in this compound correlates closely with the fine-tuning of one of the band-edge singularities to within a fraction of the superconducting energy gap Δ below the Fermi level. Our results provide compelling evidence that the band-structure singularities near the Fermi level in the iron-based superconductors must be explicitly accounted for in any attempt to understand the mechanism of superconducting pairing in these materials.

Property (RD) for Hecke Pairs

International Nuclear Information System (INIS)

Shirbisheh, Vahid

2012-01-01

As the first step towards developing noncommutative geometry over Hecke C ∗ -algebras, we study property (RD) (Rapid Decay) for Hecke pairs. When the subgroup H in a Hecke pair (G, H) is finite, we show that the Hecke pair (G, H) has (RD) if and only if G has (RD). This provides us with a family of examples of Hecke pairs with property (RD). We also adapt Paul Jolissant’s works in Jolissaint (J K-Theory 2:723–735, 1989; Trans Amer Math Soc 317(1):167–196, 1990) to the setting of Hecke C ∗ -algebras and show that when a Hecke pair (G, H) has property (RD), the algebra of rapidly decreasing functions on the set of double cosets is closed under holomorphic functional calculus of the associated (reduced) Hecke C ∗ -algebra. Hence they have the same K 0 -groups.

Shell model truncation schemes for rotational nuclei

International Nuclear Information System (INIS)

Halse, P.; Jaqua, L.; Barrett, B.R.

1990-01-01

The suitability of the pair condensate approach for rotational states is studied in a single j = 17/2 shell of identical nucleons interacting through a quadrupole-quadrupole hamiltonian. The ground band and a K = 2 excited band are both studied in detail. A direct comparison of the exact states with those constituting the SD and SDG subspaces is used to identify the important degrees of freedom for these levels. The range of pairs necessary for a good description is found to be highly state dependent; S and D pairs are the major constituents of the low-spin ground band levels, while G pairs are needed for those in the γ-band. Energy spectra are obtained for each truncated subspace. SDG pairs allow accurate reproduction of the binding energy and K = 2 excitation energy, but still give a moment of inertia which is about 30% too small even for the lowest levels

Impact of band structure and transition matrix elements on polarization properties of the photoluminescence of semipolar and nonpolar InGaN quantum wells

Energy Technology Data Exchange (ETDEWEB)

Schade, L.; Schwarz, U.T. [Department of Microsystems Engineering, University of Freiburg, Georges-Koehler-Allee 103, 79108 Freiburg (Germany); Fraunhofer Institute for Applied Solid State Physics (IAF), Tullastrasse 72, 79108 Freiburg (Germany); Wernicke, T. [Institute of Solid State Physics, Technical University, Hardenbergstrasse 36, 10623 Berlin (Germany); Weyers, M. [Ferdinand-Braun-Institut fuer Hoechstfrequenztechnik, Gustav-Kirchhoff-Strasse 4, 12489 Berlin (Germany); Kneissl, M. [Institute of Solid State Physics, Technical University, Hardenbergstrasse 36, 10623 Berlin (Germany); Ferdinand-Braun-Institut fuer Hoechstfrequenztechnik, Gustav-Kirchhoff-Strasse 4, 12489 Berlin (Germany)

2011-03-15

Partial or full linear polarization is characteristic for the spontaneous emission of light from semipolar and nonpolar InGaN quantum wells. This property is an implication of the crystalline anisotropy as a basic property of the wurtzite structure. The influence of this anisotropy on the band structure and the transition matrix elements was calculated by a k.p-method for arbitrary quantum well orientations with respect to the c-axis; results are shown here in detail. Optical polarization is a direct consequence of a broken symmetry, mainly affecting the transition matrix elements from the conduction to the valence bands. Furthermore, the strain of the InGaN quantum well strongly depends on the crystal orientation of the substrate, resulting in a valence band mixing. The composition of the eigenfunctions has emerged to be most important for the polarization dependence of strained semipolar and nonpolar InGaN QW. The matrix elements, in combination with the thermal occupation of the bands, determine the polarization of the spontaneously emitted light. Our photoluminescence measurements of nonpolar QW match well with this model. However, in contrast to calculations with standard band parameters, the two topmost subbands show a larger separation in the emitted energy. (Copyright copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

High Efficiency S-Band 20 Watt Amplifier

Data.gov (United States)

National Aeronautics and Space Administration — This project includes the design and build of a prototype 20 W, high efficiency, S-Band amplifier.   The design will incorporate the latest semiconductor technology,...

Singlet-paired coupled cluster theory for open shells

Science.gov (United States)

Gomez, John A.; Henderson, Thomas M.; Scuseria, Gustavo E.

2016-06-01

Restricted single-reference coupled cluster theory truncated to single and double excitations accurately describes weakly correlated systems, but often breaks down in the presence of static or strong correlation. Good coupled cluster energies in the presence of degeneracies can be obtained by using a symmetry-broken reference, such as unrestricted Hartree-Fock, but at the cost of good quantum numbers. A large body of work has shown that modifying the coupled cluster ansatz allows for the treatment of strong correlation within a single-reference, symmetry-adapted framework. The recently introduced singlet-paired coupled cluster doubles (CCD0) method is one such model, which recovers correct behavior for strong correlation without requiring symmetry breaking in the reference. Here, we extend singlet-paired coupled cluster for application to open shells via restricted open-shell singlet-paired coupled cluster singles and doubles (ROCCSD0). The ROCCSD0 approach retains the benefits of standard coupled cluster theory and recovers correct behavior for strongly correlated, open-shell systems using a spin-preserving ROHF reference.

Singlet-paired coupled cluster theory for open shells

International Nuclear Information System (INIS)

Gomez, John A.; Henderson, Thomas M.; Scuseria, Gustavo E.

2016-01-01

Restricted single-reference coupled cluster theory truncated to single and double excitations accurately describes weakly correlated systems, but often breaks down in the presence of static or strong correlation. Good coupled cluster energies in the presence of degeneracies can be obtained by using a symmetry-broken reference, such as unrestricted Hartree-Fock, but at the cost of good quantum numbers. A large body of work has shown that modifying the coupled cluster ansatz allows for the treatment of strong correlation within a single-reference, symmetry-adapted framework. The recently introduced singlet-paired coupled cluster doubles (CCD0) method is one such model, which recovers correct behavior for strong correlation without requiring symmetry breaking in the reference. Here, we extend singlet-paired coupled cluster for application to open shells via restricted open-shell singlet-paired coupled cluster singles and doubles (ROCCSD0). The ROCCSD0 approach retains the benefits of standard coupled cluster theory and recovers correct behavior for strongly correlated, open-shell systems using a spin-preserving ROHF reference.

Strongly coupled band in {sup 140}Gd

Energy Technology Data Exchange (ETDEWEB)

Falla-Sotelo, F.; Oliveira, J.R.B.; Rao, M.N. [Instituto de Fisica, Universidade de Sao Paulo, Sao Paulo (Brazil)] (and others)

2005-07-01

Several high-K states are known to exist in the mass 130-140 region. For the N=74 even-even isotopes, K{pi} = 8{sup -} isomers, with lifetimes ranging from ns to ms, are known in {sup 128}Xe, {sup 130}Ba, {sup 132}Ce, {sup 134}Nd, {sup 136}Sm, and {sup 138}Gd[. In {sup 140}Gd, we have observed for the first time a band also based on an I{pi} = 8{sup -} state. This could be the first case of a K{pi} = 8{sup -} state observed in an N=76 even-even isotope. The systematics of the K{pi} = 8{sup -} isomeric states in N=74 isotopes has been studied by A.M. Bruce et al. These states decay towards the K = 0 ground state band, and the transitions are K-forbidden. The {sup 140}Gd case presents strong similarities but also some significant differences with relation to the N=74 isotopes. We propose the same configuration but with larger deformation in {sup 140}Gd.

CHEMICAL ABUNDANCES IN FIELD RED GIANTS FROM HIGH-RESOLUTION H-BAND SPECTRA USING THE APOGEE SPECTRAL LINELIST

International Nuclear Information System (INIS)

Smith, Verne V.; Cunha, Katia; Shetrone, Matthew D.; Meszaros, Szabolcs; Allende Prieto, Carlos; Bizyaev, Dmitry; Garcìa Pèrez, Ana; Majewski, Steven R.; Schiavon, Ricardo; Holtzman, Jon; Johnson, Jennifer A.

2013-01-01

High-resolution H-band spectra of five bright field K, M, and MS giants, obtained from the archives of the Kitt Peak National Observatory Fourier transform spectrometer, are analyzed to determine chemical abundances of 16 elements. The abundances were derived via spectrum synthesis using the detailed linelist prepared for the Sloan Digital Sky Survey III Apache Point Galactic Evolution Experiment (APOGEE), which is a high-resolution near-infrared spectroscopic survey to derive detailed chemical abundance distributions and precise radial velocities for 100,000 red giants sampling all Galactic stellar populations. The red giant sample studied here was chosen to probe which chemical elements can be derived reliably from the H-band APOGEE spectral region. These red giants consist of two K-giants (α Boo and μ Leo), two M-giants (β And and δ Oph), and one thermally pulsing asymptotic giant branch (TP-AGB) star of spectral type MS (HD 199799). Measured chemical abundances include the cosmochemically important isotopes 12 C, 13 C, 14 N, and 16 O, along with Mg, Al, Si, K, Ca, Ti, V, Cr, Mn, Fe, Co, Ni, and Cu. The K and M giants exhibit the abundance signature of the first dredge-up of CN-cycle material, while the TP-AGB star shows clear evidence of the addition of 12 C synthesized during 4 He-burning thermal pulses and subsequent third dredge-up. A comparison of the abundances derived here with published values for these stars reveals consistent results to ∼0.1 dex. The APOGEE spectral region and linelist is thus well suited for probing both Galactic chemical evolution, as well as internal nucleosynthesis and mixing in populations of red giants via high-resolution spectroscopy.

CHEMICAL ABUNDANCES IN FIELD RED GIANTS FROM HIGH-RESOLUTION H-BAND SPECTRA USING THE APOGEE SPECTRAL LINELIST

Energy Technology Data Exchange (ETDEWEB)

Smith, Verne V.; Cunha, Katia [National Optical Astronomy Observatories, Tucson, AZ 85719 (United States); Shetrone, Matthew D. [Department of Astronomy and McDonald Observatory, University of Texas, Austin, TX 78712 (United States); Meszaros, Szabolcs; Allende Prieto, Carlos [Instituto d' Astrofisica de Canarias, E-38205, La Laguna, Tenerife (Spain); Bizyaev, Dmitry [Apache Point Observatory, Sunspot, NM 88349 (United States); Garcia Perez, Ana; Majewski, Steven R. [Department of Astronomy, University of Virginia, Charlottesville, VA 22904 (United States); Schiavon, Ricardo [Astrophysics Research Institute, Liverpool John Moores University, Liverpool L3 5UX (United Kingdom); Holtzman, Jon [Department of Astronomy, New Mexico State University, Las Cruces, NM 88003 (United States); Johnson, Jennifer A., E-mail: vsmith@noao.edu [Department of Astronomy, Ohio State University, Columbus, OH 43210 (United States)

2013-03-01

High-resolution H-band spectra of five bright field K, M, and MS giants, obtained from the archives of the Kitt Peak National Observatory Fourier transform spectrometer, are analyzed to determine chemical abundances of 16 elements. The abundances were derived via spectrum synthesis using the detailed linelist prepared for the Sloan Digital Sky Survey III Apache Point Galactic Evolution Experiment (APOGEE), which is a high-resolution near-infrared spectroscopic survey to derive detailed chemical abundance distributions and precise radial velocities for 100,000 red giants sampling all Galactic stellar populations. The red giant sample studied here was chosen to probe which chemical elements can be derived reliably from the H-band APOGEE spectral region. These red giants consist of two K-giants ({alpha} Boo and {mu} Leo), two M-giants ({beta} And and {delta} Oph), and one thermally pulsing asymptotic giant branch (TP-AGB) star of spectral type MS (HD 199799). Measured chemical abundances include the cosmochemically important isotopes {sup 12}C, {sup 13}C, {sup 14}N, and {sup 16}O, along with Mg, Al, Si, K, Ca, Ti, V, Cr, Mn, Fe, Co, Ni, and Cu. The K and M giants exhibit the abundance signature of the first dredge-up of CN-cycle material, while the TP-AGB star shows clear evidence of the addition of {sup 12}C synthesized during {sup 4}He-burning thermal pulses and subsequent third dredge-up. A comparison of the abundances derived here with published values for these stars reveals consistent results to {approx}0.1 dex. The APOGEE spectral region and linelist is thus well suited for probing both Galactic chemical evolution, as well as internal nucleosynthesis and mixing in populations of red giants via high-resolution spectroscopy.

Magnetron based high energy S-band linac system

International Nuclear Information System (INIS)

Tiwari, T.; Krishnan, R.; Phatangare, Manoj

2012-01-01

This paper deals with the study of magnetron based high energy S-band linear accelerator (linac) system operating at spot frequency 2.998 GHz. The energy and dose are two important parameters of linac system which depend on input power of microwave source and length of linac tube. Here the author has studied how these parameters can be improved for side coupled standing wave S-band linac system

Investigations into nuclear pairing

International Nuclear Information System (INIS)

Clark, R.M.

2006-01-01

This paper is divided in two main sections focusing on different aspects of collective nuclear behavior. In the first section, solutions are considered for the collective pairing Hamiltonian. In particular, an approximate solution at the critical point of the pairing transition from harmonic vibration (normal nuclear behavior) to deformed rotation (superconducting behavior) in gauge space is found by analytic solution of the Hamiltonian. The eigenvalues are expressed in terms of the zeros of Bessel functions of integer order. The results are compared to the pairing bands based on the Pb isotopes. The second section focuses on the experimental search for the Giant Pairing Vibration (GPV) in nuclei. After briefly describing the origin of the GPV, and the reasons that the state has remained unidentified, a novel idea for populating this state is presented. A recent experiment has been performed using the LIBERACE+STARS detector system at the 88-Inch Cyclotron of LBNL to test the idea. (Author)

Evaluation of the Legibility of Broken Lines for Partial Sight

OpenAIRE

小林, 秀之

2000-01-01

The present study was designed to investigate the legibility of broken lines for persons with partial sight. The subjects were 10 persons with simulated partial sight, and 4 persons with partial sight. The simulation was obtained using filters and convex lenses. The 30 kind of broken lines was evaluated by the original test that the subjects were read directions of the broken lines in distinction from solid lines. The thickness of lines varied from 0.1mm. to 0.7mm. in 4 steps. The results...

Anisotropy and multi-band effects in weak-coupling superconductors

International Nuclear Information System (INIS)

Berger, T.L.

1977-01-01

The techniques of second quantization and thermodynamic Green functions are used to investigate energy gap anisotropy and multi-band effects in pure, single-crystal, weak-coupling superconductors. A generalized version of the standard Gorkov factorization is used to linearize the Green functions equations of motion. The effects of lattice periodicity and band structure are taken into account by means of Bloch wave expansions and Bloch transforms. A pairing selection rule is derived which indicates the possibility of pairing between single particle states belonging to different bands, as well as the usual Cooper pairing. It is shown that the interband gap parameter, which is coupled to the usual gap parameter by the Green functions equations of motion, can only contribute indirectly to the tunneling electric current and the thermodynamic potential. In the absence of interband pairing, the equations of motion lead to the usual BCS gap equation. Also, in the absence of interband pairing, the gap parameter is found to be equal to the diagonal matrix element of the superconductor pair potential between electronic Bloch states. An essentially temperature independent anisotropy function which contains all angular dependence of the gap is shown to evolve naturally from this formalism. The overall temperature dependence of the gap is investigated and it is found that with a change of temperature, the magnitude of the gap in different directions changes in the same ration. The ordinary Markowitz-Kadanoff model is shown to be inappropriate for the case of a multi-band superconductor and a generalized version of this model is introduced and discussed. A special case of this model is considered which leads to gap discontinuities at Brillouin zone boundaries

Comparison and fit of the two and six band k.p models for the band edge structure of Pbsub(1-x)Snsub(x)Te

International Nuclear Information System (INIS)

Weissman, Y.

1975-10-01

The band edge structure of Pbsub(1-x)Snsub(x)Te is derived in detail using a two band ellipsoidal model and compared with a more rigorous calculation based on six bands. A quantitative comparison is made for two values of the energy gap, corresponding to the cases where x=0 and x=0.17. It was found that, for the occupied states in nondegenerate materials, both models are practically equivalent. Discrepancies may occur only in high degeneracies or deep inversion layers. The agreement between both models was significantly improved by introducing an effective energy gap in the two band model. It is suggested that the use of the effective energy gap may improve the agreement between the two band model and experiment whenever the details of the band edge structure enter the interpretation of the experimental results. (author)

Revisiting Short-Wave-Infrared (SWIR) Bands for Atmospheric Correction in Coastal Waters

Science.gov (United States)

Pahlevan, Nima; Roger, Jean-Claude; Ahmad, Ziauddin

2017-01-01

The shortwave infrared (SWIR) bands on the existing Earth Observing missions like MODIS have been designed to meet land and atmospheric science requirements. The future geostationary and polar-orbiting ocean color missions, however, require highly sensitive SWIR bands (greater than 1550nm) to allow for a precise removal of aerosol contributions. This will allow for reasonable retrievals of the remote sensing reflectance (R(sub rs)) using standard NASA atmospheric corrections over turbid coastal waters. Design, fabrication, and maintaining high-performance SWIR bands at very low signal levels bear significant costs on dedicated ocean color missions. This study aims at providing a full analysis of the utility of alternative SWIR bands within the 1600nm atmospheric window if the bands within the 2200nm window were to be excluded due to engineering/cost constraints. Following a series of sensitivity analyses for various spectral band configurations as a function of water vapor amount, we chose spectral bands centered at 1565 and 1675nm as suitable alternative bands within the 1600nm window for a future geostationary imager. The sensitivity of this band combination to different aerosol conditions, calibration uncertainties, and extreme water turbidity were studied and compared with that of all band combinations available on existing polar-orbiting missions. The combination of the alternative channels was shown to be as sensitive to test aerosol models as existing near-infrared (NIR) band combinations (e.g., 748 and 869nm) over clear open ocean waters. It was further demonstrated that while in extremely turbid waters the 1565/1675 band pair yields R(sub rs) retrievals as good as those derived from all other existing SWIR band pairs (greater than 1550nm), their total calibration uncertainties must be less than 1% to meet current science requirements for ocean color retrievals (i.e., delta R(sub rs) (443) less than 5%). We further show that the aerosol removal using the

Plasmon Lifetime in K: A Case Study of Correlated Electrons in Solids Amenable to Ab Initio Theory

International Nuclear Information System (INIS)

Ku, W.; Eguiluz, A.G.

1999-01-01

We solve the puzzle posed by the anomalous dispersion of the plasmon linewidth in K via all-electron density-response calculations, performed within the framework of time-dependent density-functional theory. The key damping mechanism is shown to be decay into particle-hole pairs involving empty states of d symmetry. While the effect of many-particle correlations is small, the correlations built into the 'final-state' d bands play an important, and novel, role related to the phase-space complexity introduced by these flat bands. Our case study of plasmon lifetime in K illustrates the importance of ab initio paradigms for the study of excitations in correlated-electron systems. copyright 1999 The American Physical Society

The Keck/OSIRIS Nearby AGN Survey (KONA). I. The Nuclear K-band Properties of Nearby AGN

Science.gov (United States)

Müller-Sánchez, F.; Hicks, E. K. S.; Malkan, M.; Davies, R.; Yu, P. C.; Shaver, S.; Davis, B.

2018-05-01

We introduce the Keck OSIRIS Nearby AGN survey (KONA), a new adaptive optics-assisted integral-field spectroscopic survey of Seyfert galaxies. KONA permits at ∼0.″1 resolution a detailed study of the nuclear kinematic structure of gas and stars in a representative sample of 40 local bona fide active galactic nucleus (AGN). KONA seeks to characterize the physical processes responsible for the coevolution of supermassive black holes and galaxies, principally inflows and outflows. With these IFU data of the nuclear regions of 40 Seyfert galaxies, the KONA survey will be able to study, for the first time, a number of key topics with meaningful statistics. In this paper we study the nuclear K-band properties of nearby AGN. We find that the K-band (2.1 μm) luminosities of the compact Seyfert 1 nuclei are correlated with the hard X-ray luminosities, implying a non-stellar origin for the majority of the continuum emission. The best-fit correlation is log L K = 0.9log L 2–10 keV + 4 over three orders of magnitude in both K-band and X-ray luminosities. We find no strong correlation between 2.1 μm luminosity and hard X-ray luminosity for the Seyfert 2 galaxies. The spatial extent and spectral slope of the Seyfert 2 galaxies indicate the presence of nuclear star formation and attenuating material (gas and dust), which in some cases is compact and in some galaxies extended. We detect coronal-line emission in 36 galaxies and for the first time in 5 galaxies. Finally, we find 4/20 galaxies that are usually classified as Seyfert 2 based on their optical spectra exhibit a broad component of Brγ emission, and one galaxy (NGC 7465) shows evidence of a double nucleus. Based on observations at the W. M. Keck Observatory, which is operated as a scientific partnership among the California Institute of Technology, the University of California, and the National Aeronautics and Space Administration. The observatory was made possible by the generous financial support of the W. M

Microscopical study of K isomers in the nuclear region A ∼ 180

International Nuclear Information System (INIS)

Libert, J.; Quentin, P.; Pillet, N.; Ponsa, A.

1997-01-01

At present the K isomers are the best candidates for high density energy storage, although one of the major problems resides in the availability of simple and fast storage mechanisms. To respond to this question it is necessary to know thoroughly the structure of the concerned isomers and low energy modes of excitation. Particularly, proper to this type of studies is the region of A ∼ 180, where a large number of K isomers are known at present ( 178 Hf, 179 Hf and 180 Ta). Microscopic calculations using Skyrme SIII plus a simple pairing interaction lead to a good reproduction of certain single particle and collective spectroscopic properties of 178 Hf. In this region the spectroscopic properties are governed by three single proton states (5/2 - , 7/2 - and 9/2 + ) and by two single neutron states (7/2 + , 9/2 - ). The computed quasi-particle spectrum reproduces within 100 keV the energies of the isomeric states 16 + , 14 - , 25/2 - and 9 - . Based on this agreement one can predict a band spectroscopy rich in high K values due to a plenty of possible single particle combinations which have themselves high K value. Particularly, one have to stress the quasi-degeneracy of a K π = 15 + with the 16 + configuration in 178 Hf. Should this prediction experimentally be confirmed interesting consequences have to be expected on the spectroscopy above the 16 + isomer of 178 Hf as well as on the states implied in the decay of this storage state. Actually, 1 MeV above the 16 + state one can note isolated states reachable by parity breaking (or not breaking) transitions which could be mixture of K = 15, 14, 13, etc structures due to Coriolis interaction. The calculation reported are although simple (the approximation of the free quasi-particles on the BCS vacuum of 178 Hf). Under current study are the quantitative consequences of the Coriolis coupling, the decrease of pairing gaps with increasing quasi-particle number, the Hartree-Fock polarization (even and odd under time

[Dehydration due to "mouth broken"].

Science.gov (United States)

Meijler, D P M; van Mossevelde, P W J; van Beek, R H T

2012-09-01

Two children were admitted to a medical centre due to dehydration after an oral injury and the extraction of a tooth. One child complained of "mouth broken". Dehydration is the most common water-electrolyte imbalance in children. Babies and young children are prone to dehydration due to their relatively large body surface area, the high percentage extracellular fluid, and the limited ability of the kidneys to conserve water. After the removal ofa tooth, after an oral trauma or in case of oral discomfort, a child is at greater risk of dehydration by reduced fluid and food intake due to oral pain and/or discomfort and anxiety to drink. In those cases, extra attention needs to be devoted to the intake of fluids.

Maintaining K+ balance on the low-Na+, high-K+ diet

Science.gov (United States)

Cornelius, Ryan J.; Wang, Bangchen; Wang-France, Jun

2016-01-01

A low-Na+, high-K+ diet (LNaHK) is considered a healthier alternative to the “Western” high-Na+ diet. Because the mechanism for K+ secretion involves Na+ reabsorptive exchange for secreted K+ in the distal nephron, it is not understood how K+ is eliminated with such low Na+ intake. Animals on a LNaHK diet produce an alkaline load, high urinary flows, and markedly elevated plasma ANG II and aldosterone levels to maintain their K+ balance. Recent studies have revealed a potential mechanism involving the actions of alkalosis, urinary flow, elevated ANG II, and aldosterone on two types of K+ channels, renal outer medullary K+ and large-conductance K+ channels, located in principal and intercalated cells. Here, we review these recent advances. PMID:26739887

Fluctuation relations for equilibrium states with broken discrete or continuous symmetries

International Nuclear Information System (INIS)

Lacoste, D; Gaspard, P

2015-01-01

Isometric fluctuation relations are deduced for the fluctuations of the order parameter in equilibrium systems of condensed-matter physics with broken discrete or continuous symmetries. These relations are similar to their analogues obtained for non-equilibrium systems where the broken symmetry is time reversal. At equilibrium, these relations show that the ratio of the probabilities of opposite fluctuations goes exponentially with the symmetry-breaking external field and the magnitude of the fluctuations. These relations are applied to the Curie–Weiss, Heisenberg, and XY models of magnetism where the continuous rotational symmetry is broken, as well as to the q-state Potts model and the p-state clock model where discrete symmetries are broken. Broken symmetries are also considered in the anisotropic Curie–Weiss model. For infinite systems, the results are calculated using large-deviation theory. The relations are also applied to mean-field models of nematic liquid crystals where the order parameter is tensorial. Moreover, their extension to quantum systems is also deduced. (paper)

Variational study of the pair hopping model

International Nuclear Information System (INIS)

Fazekas, P.

1990-01-01

We study the ground state of a Hamiltonian introduced by Kolb and Penson for modelling situations in which small electron pairs are formed. The Hamiltonian consists of a tight binding band term, and a term describing the nearest neighbour hopping of electron pairs. We give a Gutzwiller-type variational treatment, first with a single-parameter Ansatz treated in the single site Gutzwiller approximation, and then with more complicated trial wave functions, and an improved Gutzwiller approximation. The calculation yields a transition from a partially paired normal state, in which the spin susceptibility has a diminished value, into a fully paired state. (author). 16 refs, 2 figs

High gradient test of X-band accelerating structure at GLCTA

International Nuclear Information System (INIS)

Watanabe, K.; Higo, T.; Hayano, H.; Terunuma, N.; Saeki, T.; Kudo, N.; Sanuki, T.; Seuhara, T.

2004-01-01

GLCTA (Global Linear Collider Test Accelerator) is the high power test facility for X-band acceleration. We have installed an X-band 60cm structure in April 2004 and have been processing it for more than 3 months. Now it is under test on long-term operation. We report here the installation process and high power test result to date. (author)

Broken superfluid in dense quark matter

Energy Technology Data Exchange (ETDEWEB)

Parganlija, Denis; Schmitt, Andreas [Institut fuer Theoretische Physik, Technische Universitaet Wien, 1040 Vienna (Austria); Alford, Mark [Department of Physics, Washington University St Louis, MO, 63130 (United States)

2014-07-01

Quark matter at high densities is a superfluid. Properties of the superfluid become highly non-trivial if the effects of strange-quark mass and the weak interactions are considered. These properties are relevant for a microscopic description of compact stars. We discuss the effect of a (small) explicitly symmetry-breaking term on the properties of a zero-temperature superfluid in a relativistic φ{sup 4} theory. If the U(1) symmetry is exact, chemical potential and superflow can be equivalently introduced either via (1) a background gauge field or (2) a topologically nontrivial mode. However, in the case of the explicitly broken symmetry, we demonstrate that the scenarios (1) and (2) lead to quantitatively different results for the mass of the pseudo-Goldstone mode and the critical velocity for superfluidity.

High resolution study of high mass pairs and high transverse momentum particles

International Nuclear Information System (INIS)

Smith, S.R.

1983-01-01

Preliminary experiments involving the high resolution spectrometer (experiment 605) at Fermilab are described. The spectrometer is designed for the study of pairs of particles at large invariant masses and single particles at large transverse momenta. A number of applications of the apparatus in the study of Drell-Yan processes, e.g. transverse momentum measurement, are discussed

Alpha band frequency differences between low-trait and high-trait anxious individuals.

Science.gov (United States)

Ward, Richard T; Smith, Shelby L; Kraus, Brian T; Allen, Anna V; Moses, Michael A; Simon-Dack, Stephanie L

2018-01-17

Trait anxiety has been shown to cause significant impairments on attentional tasks. Current research has identified alpha band frequency differences between low-trait and high-trait anxious individuals. Here, we further investigated the underlying alpha band frequency differences between low-trait and high-trait anxious individuals during their resting state and the completion of an inhibition executive functioning task. Using human participants and quantitative electroencephalographic recordings, we measured alpha band frequency in individuals both high and low in trait anxiety during their resting state, and while they completed an Eriksen Flanker Task. Results indicated that high-trait anxious individuals exhibit a desynchronization in alpha band frequency from a resting state to when they complete the Eriksen Flanker Task. This suggests that high-trait anxious individuals maintain fewer attentional resources at rest and must martial resources for task performance as compared with low-trait anxious individuals, who appear to maintain stable cognitive resources between rest and task performance. These findings add to the cognitive neuroscience literature surrounding the role of alpha band frequency in low-trait and high-trait anxious individuals.

Pair-breaking effects by parallel magnetic field in electric-field-induced surface superconductivity

International Nuclear Information System (INIS)

Nabeta, Masahiro; Tanaka, Kenta K.; Onari, Seiichiro; Ichioka, Masanori

2016-01-01

Highlights: • Zeeman effect shifts superconducting gaps of sub-band system, towards pair-breaking. • Higher-level sub-bands become normal-state-like electronic states by magnetic fields. • Magnetic field dependence of zero-energy DOS reflects multi-gap superconductivity. - Abstract: We study paramagnetic pair-breaking in electric-field-induced surface superconductivity, when magnetic field is applied parallel to the surface. The calculation is performed by Bogoliubov-de Gennes theory with s-wave pairing, including the screening effect of electric fields by the induced carriers near the surface. Due to the Zeeman shift by applied fields, electronic states at higher-level sub-bands become normal-state-like. Therefore, the magnetic field dependence of Fermi-energy density of states reflects the multi-gap structure in the surface superconductivity.

Gamma band odd-even staggering in some deformed nuclei

International Nuclear Information System (INIS)

Khairy, M.K.; Talaat, SH.M.; Morsy, M.

2005-01-01

A complete investigation was carried out in studying the odd-even staggering (OES) of gamma bands energy levels in some deformed nuclei up to angular momentum L=13 . With the help of Minkov treatment in the framework of a collective Vector Boson Model (VBM) with broken SU (3) symmetry. The OES behavior of deformed isotopes 162 E r, 164 E r, 166 E r, 156 G d, 170 Y b and 232 T h was studied and discussed

minimal pairs of polytopes and their number of vertices

African Journals Online (AJOL)

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Using this operation we give a new algorithm to reduce and find a minimal pair of polytopes from the given ... Key words/phrases: Pairs of compact convex sets, Blaschke addition, Minkowski sum, mnimality ... product K(X)×K(X) by K2. (X).

High mobility and high concentration Type-III heterojunction FET

Science.gov (United States)

Tsu, R.; Fiddy, M. A.; Her, T.

2018-02-01

The PN junction was introduced in transistors by doping, resulting in high losses due to Coulomb scattering from the dopants. The MOSFET introduced carriers in the form of electrons and holes with an applied bias to the oxide barrier, resulting in carrier transfer without doping. This avoids high scattering losses and dominates the IC industries. With heterojunctions having valence-band maxima near and even above the conduction-band minimum in the formation of Type-III superlattices, very useful devices, introduced by Tsu, Sai-Halacz, and Esaki, soon followed. If the layer thicknesses are more than the carrier mean-free-path, incoherent scattering results in the formation of carrier transfer via diffusion instead of opening up new energy gaps. The exploitation of carriers without scattering represents a new and significant opportunity in what we call a Broken Gap Heterojunction FET.

Strongly coupled band in 140Gd

International Nuclear Information System (INIS)

Falla-Sotelo, F.; Oliveira, J.R.B.; Rao, M.N.

2005-01-01

Several high-K states are known to exist in the mass 130-140 region. For the N=74 even-even isotopes, Kπ = 8 - isomers, with lifetimes ranging from ns to ms, are known in 128 Xe, 130 Ba, 132 Ce, 134 Nd, 136 Sm, and 138 Gd[. In 140 Gd, we have observed for the first time a band also based on an Iπ = 8 - state. This could be the first case of a Kπ = 8 - state observed in an N=76 even-even isotope. The systematics of the Kπ = 8 - isomeric states in N=74 isotopes has been studied by A.M. Bruce et al. These states decay towards the K = 0 ground state band, and the transitions are K-forbidden. The 140 Gd case presents strong similarities but also some significant differences with relation to the N=74 isotopes. We propose the same configuration but with larger deformation in 140 Gd

Mental Suffering in Protracted Political Conflict: Feeling Broken or Destroyed.

Science.gov (United States)

Barber, Brian K; McNeely, Clea A; El Sarraj, Eyad; Daher, Mahmoud; Giacaman, Rita; Arafat, Cairo; Barnes, William; Abu Mallouh, Mohammed

2016-01-01

This mixed-methods exploratory study identified and then developed and validated a quantitative measure of a new construct of mental suffering in the occupied Palestinian territory: feeling broken or destroyed. Group interviews were conducted in 2011 with 68 Palestinians, most aged 30-40, in the West Bank, East Jerusalem, and the Gaza Strip to discern local definitions of functioning. Interview participants articulated of a type of suffering not captured in existing mental health instruments used in regions of political conflict. In contrast to the specific difficulties measured by depression and PTSD (sleep, appetite, energy, flashbacks, avoidance, etc.), participants elaborated a more existential form of mental suffering: feeling that one's spirit, morale and/or future was broken or destroyed, and emotional and psychological exhaustion. Participants articulated these feelings when describing the rigors of the political and economic contexts in which they live. We wrote survey items to capture these sentiments and administered these items-along with standard survey measures of mental health-to a representative sample of 1,778 32-43 year olds in the occupied Palestinian territory. The same survey questions also were administered to a representative subsample (n = 508) six months earlier, providing repeated measures of the construct. Across samples and time, the feeling broken or destroyed scale: 1) comprised a separate factor in exploratory factor analyses, 2) had high inter-item consistency, 3) was reported by both genders and in all regions, 4) showed discriminate validity via moderate correlations with measures of feelings of depression and trauma-related stress, and 5) was more commonly experienced than either feelings of depression or trauma-related stress. Feeling broken or destroyed can be reliably measured and distinguished from conventional measures of mental health. Such locally grounded and contextualized measures should be identified and included in

Pair momentum distribution in Bi2Sr2CaCu2O8+δ measured by positron annihilation: Existence and nature of the Fermi surface

International Nuclear Information System (INIS)

Chan, L.P.; Harshman, D.R.; Lynn, K.G.; Massidda, S.; Mitzi, D.B.

1991-01-01

We report the first measurement of the positron-electron momentum density in superconducting single-crystal Bi 2 Sr 2 CaCu 2 O 8+δ (T c ∼90 K). The observed anisotropy exhibits a twofold (rather than fourfold) symmetry, which is attributed to the superlattice modulation along the b axis of the BiO 2 layers. Subtraction of the superlattice contribution also reveals a pair momentum distribution consistent with the CuO 2 and BiO 2 Fermi surfaces, and in reasonable agreement with the theoretical pair momentum density derived from band theory

Pair momentum distribution in Bi2Sr2CaCu2O(8+delta) measured by positron annihilation - Existence and nature of the Fermi surface

Science.gov (United States)

Chan, L. P.; Lynn, K. G.; Harshman, D. R.; Massidda, S.; Mitzi, D. B.

1991-09-01

The first measurement is reported of the position-electron momentum density in superconducting single-crystal Bi2Sr2CaCu2O(8+delta)(Tc roughly 90 K). The observed anisotropy exhibits a twofold (rather than fourfold) symmetry, which is attributed to the superlattice modulation along the b axis of the BiO2 layers. Subtraction of the superlattice contribution also reveals a pair momentum distribution consistent with the CuO2 and BiO2 Fermi surfaces, and in reasonable agreement with the theoretical pair momentum density derived from band theory.

Design and development of a 6 MW peak, 24 kW average power S-band klystron

Energy Technology Data Exchange (ETDEWEB)

Joshi, L.M.; Meena, Rakesh; Nangru, Subhash; Kant, Deepender; Pal, Debashis; Lamba, O.S.; Jindal, Vishnu; Jangid, Sushil Kumar, E-mail: joslm@rediffmail.com [Central Electronics Engineering Research Institute, Council of Scientific and Industrial Research, Pilani (India); Chakravarthy, D.P.; Dixit, Kavita [Bhabha Atomic Research Centre, Mumbai (India)

2011-07-01

A 6 MW peak, 24 kW average power S-band Klystron is under development at CEERI, Pilani under an MoU between BARC and CEERI. The design of the klystron has been completed. The electron gun has been designed using TRAK and MAGIC codes. RF cavities have been designed using HFSS and CST Microwave Studio while the complete beam wave interaction simulation has been done using MAGIC code. The thermal design of collector and RF window has been done using ANSYS code. A Gun Collector Test Module (GCTM) was developed before making actual klystron to validate gun perveance and thermal design of collector. A high voltage solid state pulsed modulator has been installed for performance valuation of the tube. The paper will cover the design aspects of the tube and experimental test results of GCTM and klystron. (author)

Design and development of a 6 MW peak, 24 kW average power S-band klystron

International Nuclear Information System (INIS)

Joshi, L.M.; Meena, Rakesh; Nangru, Subhash; Kant, Deepender; Pal, Debashis; Lamba, O.S.; Jindal, Vishnu; Jangid, Sushil Kumar; Chakravarthy, D.P.; Dixit, Kavita

2011-01-01

A 6 MW peak, 24 kW average power S-band Klystron is under development at CEERI, Pilani under an MoU between BARC and CEERI. The design of the klystron has been completed. The electron gun has been designed using TRAK and MAGIC codes. RF cavities have been designed using HFSS and CST Microwave Studio while the complete beam wave interaction simulation has been done using MAGIC code. The thermal design of collector and RF window has been done using ANSYS code. A Gun Collector Test Module (GCTM) was developed before making actual klystron to validate gun perveance and thermal design of collector. A high voltage solid state pulsed modulator has been installed for performance valuation of the tube. The paper will cover the design aspects of the tube and experimental test results of GCTM and klystron. (author)

Superdeformed bands of odd nuclei in A=190 region in the quasiparticle picture

International Nuclear Information System (INIS)

Terasaki, J.; Flocard, H.; Heenen, P.H.; Bonche, P.

1996-07-01

Properties of the superdeformed (SD) bands of 195 Pb and 193 Hg have been studied by the cranked Hartree-Fock-Bogoliubov method. The calculations reproduce the flat behavior of the dynamical moment of inertia of two of the SD bands of 195 Pb measured recently. Possible configuration assignments for the observed bands 3 and 4 of 195 Pb are discussed. The two interacting SD bands of 193 Hg have also been calculated. The analysis confirms the superiority of a density-dependent pairing force over a seniority pairing interaction. (author)

K-forbidden transition probabilities

International Nuclear Information System (INIS)

Saitoh, T.R.; Sletten, G.; Bark, R.A.; Hagemann, G.B.; Herskind, B.; Saitoh-Hashimoto, N.; Tsukuba Univ., Ibaraki

2000-01-01

Reduced hindrance factors of K-forbidden transitions are compiled for nuclei with A∝180 where γ-vibrational states are observed. Correlations between these reduced hindrance factors and Coriolis forces, statistical level mixing and γ-softness have been studied. It is demonstrated that the K-forbidden transition probabilities are related to γ-softness. The decay of the high-K bandheads has been studied by means of the two-state mixing, which would be induced by the γ-softness, with the use of a number of K-forbidden transitions compiled in the present work, where high-K bandheads are depopulated by both E2 and ΔI=1 transitions. The validity of the two-state mixing scheme has been examined by using the proposed identity of the B(M1)/B(E2) ratios of transitions depopulating high-K bandheads and levels of low-K bands. A break down of the identity might indicate that other levels would mediate transitions between high- and low-K states. (orig.)

Coexisting shape- and high-K isomers in the shape transitional nucleus 188Pt

Science.gov (United States)

Mukhopadhyay, S.; Biswas, D. C.; Tandel, S. K.; Danu, L. S.; Joshi, B. N.; Prajapati, G. K.; Nag, Somnath; Trivedi, T.; Saha, S.; Sethi, J.; Palit, R.; Joshi, P. K.

2014-12-01

A high-spin study of the shape transitional nucleus 188Pt reveals the unusual coexistence of both shape- and K-isomeric states. Reduced B (E2) transition probabilities for decays from these states inferred from the data clearly establish their hindered character. In addition to other excited structures, a rotational band built upon the K isomer is identified, and its configuration has been assigned through an analysis of alignments and branching ratios. The shape evolution with spin in this nucleus has been inferred from both experimental observables and cranking calculations. The yrast positive parity structure appears to evolve from a near-prolate deformed shape through triaxial at intermediate excitation, and eventually to oblate at the highest spins.

Real-space description of semiconducting band gaps in substitutional systems

International Nuclear Information System (INIS)

Magri, R.; Zunger, A.

1991-01-01

The goal of ''band-gap engineering'' in substitutional lattices is to identify atomic configurations that would give rise to a desired value of the band gap. Yet, current theoretical approaches to the problems, based largely on compilations of band structures for various latice configurations, have not yielded simple rules relating structural motifs to band gaps. We show that the band gap of substitutional AlAs/GaAs lattices can be usefully expanded in terms of a hierarchy of contributions from real-space ''atomic figures'' (pairs, triplets, quadruplets) detemined from first-principles band-structure calculations. Pair figures (up to fourth neighbors) and three-body figures are dominant. In analogy with similar cluster expansions of the total energy, this permits a systematic search among all lattice configurations for those having ''special'' band gaps. This approach enables the design of substitutional systems with certain band-gap properties by assembling atomic figures. As an illustration, we predict that the [0 bar 12]-oriented (AlAs) 1 /(GaAs) 4 /(AlAs) 1 /(GaAs) 2 superlattice has the largest band gap among all Al 0.25 Ga 0.75 As lattices with a maximum of ten cations per unit cell

Spontaneously broken realization of supersymmetry in supergravity

International Nuclear Information System (INIS)

Ferrara, S.; Trieste Univ.

1979-01-01

It is shown that if supersymmetry is relevant for the physical world it must be broken either spontaneously or explicitly. Renormalizability and simplicity are in favor of a spontaneous realization of the symmetry breaking. When supersymmetry is spontaneously broken the spinorial analogue of the Goldstone phenomenon occurs, namely massless particles arise in the spectrum of the theory which carry the same quantum numbers of the broken generators Qsup(i) they are N spin 1/2 Goldstone fermions (goldstinos). These particles may be eaten by spin 3/2 gauge particles (gravitinos) when supersymmetry is gauged. It is shown that both the Higgs effect and super Higgs effect have taken place. 8 of the spin 1/2 particles have been eaten by the spin 3/2 particles and 24 of 70 scalars have been eaten by the spin 3/2 particles and 24 of 70 scalars have been eaten by 24 of the 28 vector particles to provide them with mass. The conclusion is that the number of mass relations is, in general, equal to r-1, where r is the rank of the algebra which generates the spectrum

Ratchet device with broken friction symmetry

DEFF Research Database (Denmark)

Norden, Bengt; Zolotaryuk, Yaroslav; Christiansen, Peter Leth

2002-01-01

An experimental setup (gadget) has been made for demonstration of a ratchet mechanism induced by broken symmetry of a dependence of dry friction on external forcing. This gadget converts longitudinal oscillating or fluctuating motion into a unidirectional rotation, the direction of which is in ac......An experimental setup (gadget) has been made for demonstration of a ratchet mechanism induced by broken symmetry of a dependence of dry friction on external forcing. This gadget converts longitudinal oscillating or fluctuating motion into a unidirectional rotation, the direction of which...... is in accordance with given theoretical arguments. Despite the setup being three dimensional, the ratchet rotary motion is proved to be described by one simple dynamic equation. This kind of motion is a result of the interplay of friction and inertia....

Caring Climate, Empathy, and Student Social Behaviors in High School Band

Science.gov (United States)

Lalama, Susana M.

2016-01-01

The purpose of this study was to explore connections among perceived caring climate, empathy, and student social behaviors in high school bands. Nine high school band directors (N = 9 schools), along with their students (N = 203), completed an electronic questionnaire for variables of caring climate, cognitive empathy, affective empathy, social…

High power X-band coaxial amplifier experiments

International Nuclear Information System (INIS)

Davis, T.J.; Nation, J.A.

1991-01-01

Studies are continuing on the development of X-band coaxial microwave amplifiers as a source for next generation linear colliders. Coaxial amplifiers employ an annular electron beam propagating between inner and outer drift tube conductors, a configuration which allows large increases in beam current over standard pencil beam amplifiers. Large average diameter systems may still be used without mode competition since TM mode cutoff frequencies are controlled by the separation between conductors. A number of amplifier configurations are being studied, all primed by a driven initial cavity which resonates around 9 GHz. Simple theory of coaxial systems and particle-in-cell simulations are presented, as well as initial experimental results using a 420 keV, 7-8 kA, 9 cm diameter annular beam

Bandwidth Extension of an S-band, Fundamental-Mode Eight-Beam Klystron

Science.gov (United States)

2006-04-01

Extension of an S - band , Fundamental-Mode Eight-Beam Klystron Khanh T. Nguyen Beam-Wave Research, Inc. Bethesda, MD 20814 Dean E. Pershing ATK Mission...of a five-cavity, approximately 18 cm downstream from the center of the broadband, high - power multiple-beam klystron (MBK) first gap - the logical...the circuit generates >550 kW across the band with a peak power of more than 600 kW at -3.27 Keywords: Multiple-beam klystron ; MBK; bandwidth GHz. The 1

[Suicidal behavior and the broken home. Critical evaluation of a "causal hypothesis"].

Science.gov (United States)

Schaller, S; Schmidtke, A

1988-06-01

It has often been hypothesized that a broken home results in a "predisposition" towards suicidal behaviour. Previous findings concerning the incidence of broken homes among suicides have revealed rates that are considerably higher than might have been expected from the base rate of the incidence of broken homes among the population as a whole. However, when considering these results, it is necessary to take into account a number of general methodological problems as well as specific problems inherent in the study of the causes of suicidal behaviour. Therefore, due to methodological objections, it can be assumed that the covariation between the variable, broken home, and suicidal behaviour, as compared with other psychiatric disturbances, has been overestimated. It seems more likely that a broken home, in combination with the simultaneous and subsequent emergence of adverse circumstances, increases the probability of the appearance of deviant behaviour in general. Therefore, it would appear that the most useful approach for understanding suicidal behaviour is to analyse the learning history and background of patients who have exhibited such behaviour, while the variable, broken home, should be regarded as being only one of several factors conditioning the failure to develop or apply adequate coping strategies.

High-spin structure of 121Xe: triaxiality, band termination and signature inversion

International Nuclear Information System (INIS)

Timar, J.; Paul, E.S.; Beausang, C.W.; Joyce, M.J.; Sharpey-Schafer, J.F.

1995-01-01

High-spin states of the odd-neutron 121 Xe nucleus have been studied with Eurogam using the 96 Zr( 30 Si, 5n) 121 Xe fusion-evaporation reaction. The level scheme has been extended up to a tentative spin of 67/2h at an excitation energy of ∼ 14 MeV. Several new rotational bands have been observed and the previously known bands extended. Two of them lose their regular character at high spins, which may be interpreted as transition from collective behaviour to a regime of noncollective oblate states. The deduced high-spin structure is compared to Woods-Saxon TRS cranking and CSM calculations. Configurations of the bands have been suggested. The νh 1 1/2 band is interpreted as having a triaxial shape. Signature inversion and an unexpectedly large staggering of the B(M1)/B(E2) ratios has been found for one of the bands. Enhanced E1 transitions have been observed between the νd 5/2 and the νh 1 1/2 bands. (orig.)

High-power test of S-band klystron for long-pulse operation

International Nuclear Information System (INIS)

Morii, Y.; Oshita, E.; Abe, S.; Keishi, T.; Tomimasu, T.; Ohkubo, Y.; Yoshinao, M.; Yonezawa, H.

1994-01-01

FELI(Free Electron Laser Research Institute, Inc.) is constructing a free electron laser facility covering from 20μm (infra red region) to 0.35μm (ultra violet region), using an S-band linac. The linac is commissioning now. An RF system of the linac for FELs is required of long pulse duration and high stability. S-band klystrons (TOSHIBA E3729) of the FELI linac are operated in three pulse operation modes (pulse width and peak RF power; 24μs-24MW, 12.5μs-34MW, 0.5μs-70MW). The S-band klystron and its modulator were combined to test their performance. The high power test results of the S-band klystron are summarized in this paper. (author)

Band structure of CdTe under high pressure

International Nuclear Information System (INIS)

Jayam, Sr. Gerardin; Nirmala Louis, C.; Amalraj, A.

2005-01-01

The band structures and density of states of cadmium telluride (CdTe) under various pressures ranging from normal to 4.5 Mbar are obtained. The electronic band structure at normal pressure of CdTe (ZnS structure) is analyzed and the direct band gap value is found to be 1.654 eV. CdTe becomes metal and superconductor under high pressure but before that it undergoes structural phase transition from ZnS phase to NaCl phase. The equilibrium lattice constant, bulk modulus and the phase transition pressure at which the compounds undergo structural phase transition from ZnS to NaCl are predicted from the total energy calculations. The density of states at the Fermi level (N(E F )) gets enhanced after metallization, which leads to the superconductivity in CdTe. In our calculation, the metallization pressure (P M = 1.935 Mbar) and the corresponding reduced volume ((V/V 0 ) M = 0.458) are estimated. Metallization occurs via direct closing of band gap at Γ point. (author)

Pair shell model description of collective motions

International Nuclear Information System (INIS)

Chen Hsitseng; Feng Dahsuan

1996-01-01

The shell model in the pair basis has been reviewed with a case study of four particles in a spherical single-j shell. By analyzing the wave functions according to their pair components, the novel concept of the optimum pairs was developed which led to the proposal of a generalized pair mean-field method to solve the many-body problem. The salient feature of the method is its ability to handle within the framework of the spherical shell model a rotational system where the usual strong configuration mixing complexity is so simplified that it is now possible to obtain analytically the band head energies and the moments of inertia. We have also examined the effects of pair truncation on rotation and found the slow convergence of adding higher spin pairs. Finally, we found that when the SDI and Q .Q interactions are of equal strengths, the optimum pair approximation is still valid. (orig.)

E- and W-band high-capacity hybrid fiber-wireless link

DEFF Research Database (Denmark)

Vegas Olmos, Juan José; Pang, Xiaodan; Tafur Monroy, Idelfonso

2014-01-01

In this paper we summarize the work conducted in our group in the area of E- and W-band optical high-capacity fiber-wireless links. We present performance evaluations of E- and W-band mm-wave signal generation using photonic frequency upconversion employing both VCSELs and ECLs, along with transm...... in mobile backhaul/fronthaul applications, dense distributed antenna systems and fiber-over-radio scenarios.......In this paper we summarize the work conducted in our group in the area of E- and W-band optical high-capacity fiber-wireless links. We present performance evaluations of E- and W-band mm-wave signal generation using photonic frequency upconversion employing both VCSELs and ECLs, along...... with transmission over different type of optical fibers and for a number of values for the wireless link distance. Hybrid wireless-optical links can be composed of mature and resilient technology available off-the-shelf, and provide functionalities that can add value to optical access networks, specifically...

Luminescence of 1,4-naphthoquinone and the vitamin K system in Shpolskii matrices at 4 K

Science.gov (United States)

Vo-Dinh, Tuan; Wild, Urs P.

This work investigates the high-resolution phosphorescence spectra of 1,4-naphthoquinone and the vitamin K system in Shpolskii solvents at 4 K. The quasi-linear vibronic bands are discussed with regard to spectral assignments and polarization data. The effect of non-totally symmetric vibrations is also discussed.

Broken Homes: Impact on Adolescents.

Science.gov (United States)

Koziey, Paul W.; Davies, Leigh

1982-01-01

Tends to support assertion that children from homes broken by separation, divorce, or death are less well-adjusted in terms of California Personality Inventory scales of self-control, socialization, femininity, and good impression, than children from intact homes. Age and sex were not found to be linked to the degree of maladjustment. (AH)

A novel mechanical design of broken rope protection device for enhancing the safety performances of overhead manned equipment in coal mine

Directory of Open Access Journals (Sweden)

Xiaoguang Zhang

2015-08-01

Full Text Available A novel mechanical design of the broken rope protection device is proposed to enhance the safety performances of the overhead manned equipment. According to the operating characteristics and functional requirements of the overhead manned equipment, a three-dimensional mechanical model of the broken rope protection device was redesigned. Based on the known parameters of the mechanical model, the stress and strength of the main components are readjusted using the statics characteristics of finite element analysis. To ensure the reliability of the control system of the broken rope protection device, the process of people’s falling, the response performance of the tension sensor, and the signal extraction of the broken rope are analyzed under different loading and unloading speeds. The working principle of the broken rope protection device is expounded in detail. The experimental results showed that better effect is obtained by the new broken rope protection device, which is characterized by good durability, low investment, and high reliability.

Pairing and deformation effects in nuclear excitation spectra

Energy Technology Data Exchange (ETDEWEB)

Repko, A. [Slovak Academy of Sciences, Institute of Physics, Bratislava (Slovakia); Kvasil, J. [Charles University, Institute of Particle and Nuclear Physics, Prague (Czech Republic); Nesterenko, V.O. [Joint Institute for Nuclear Research, Laboratory of Theoretical Physics, Dubna (Russian Federation); State University ' ' Dubna' ' , Dubna (Russian Federation); Reinhard, P.G. [Universitaet Erlangen, Institut fuer Theoretische Physik II, Erlangen (Germany)

2017-11-15

We investigate effects of pairing and of quadrupole deformation on two sorts of nuclear excitations, γ-vibrational K{sup π} = 2{sup +} states and dipole resonances (isovector dipole, pygmy, compression, toroidal). The analysis is performed within the quasiparticle random phase approximation (QRPA) based on the Skyrme energy functional using the Skyrme parametrization SLy6. Particular attention is paid to i) the role of the particle-particle (pp) channel in the residual interaction of QRPA, ii) comparison of volume pairing (VP) and surface pairing (SP), iii) peculiarities of deformation splitting in the various resonances. We find that the impact of the pp-channel on the considered excitations is negligible. This conclusion applies also to any other excitation except for the K{sup π} = 0{sup +} states. Furthermore, the difference between VP and SP is found small (with exception of peak height in the toroidal mode). In the low-energy isovector dipole (pygmy) and isoscalar toroidal modes, the branch K{sup π} = 1{sup -} is shown to dominate over the K{sup π} = 0{sup -} one in the range of excitation energy E < 8-10 MeV. The effect becomes impressive for the toroidal resonance whose low-energy part is concentrated in a high peak of almost pure K{sup π} = 1{sup -} nature. This peculiarity may be used as a fingerprint of the toroidal mode in future experiments. The interplay between pygmy, toroidal and compression resonances is discussed, the interpretation of the observed isoscalar giant dipole resonance is partly revised. (orig.)

SO4--SO3- radical pair formation in Ce doped and Ce, U co-doped K3Na(SO4)2: EPR evidence and its role in TSL

International Nuclear Information System (INIS)

Natarajan, V.; Seshagiri, T.K.; Kadam, R.M.; Sastry, M.D.

2002-01-01

Thermally stimulated luminescence (TSL) and electron paramagnetic resonance (EPR) studies were carried out on cerium doped and cerium-uranium co-doped K 3 Na(SO 4 ) 2 samples after γ-irradiation. Three glow peaks around 352, 415 and 475 K were observed and their spectral characteristics have shown that Ce 3+ and UO 2 2+ act as the emission centres in K 3 Na(SO 4 ) 2 :Ce and K 3 Na(SO 4 ) 2 :Ce, U, respectively. In Ce-U co-doped sample, energy transfer from cerium to uranium takes place. The commonly occurring radiation-induced centres in sulphates, viz SO 3 - and SO 4 - were observed by EPR and SO 4 - radical ion was found to take part in the TSL emission at 415 K. The hitherto unknown information, however, is the formation of SO 4 - -SO 3 - radical pair creating deep traps in these lattices, apparently assisted by the dopants. This is the first observation of such radical pair formation leading to the identification of deep traps in this lattice. The radical pair, (SO 3 - -SO 4 - ) which is stable up to 970 K, decreases the intensity of the peak at 415 K due to the depletion of SO 4 - centres

Band Alignment Determination of Two-Dimensional Heterojunctions and Their Electronic Applications

KAUST Repository

Chiu, Ming-Hui

2018-05-09

Two-dimensional (2D) layered materials such as MoS2 have been recognized as high on-off ratio semiconductors which are promising candidates for electronic and optoelectronic devices. In addition to the use of individual 2D materials, the accelerated field of 2D heterostructures enables even greater functionalities. Device designs differ, and they are strongly controlled by the electronic band alignment. For example, photovoltaic cells require type II heterostructures for light harvesting, and light-emitting diodes benefit from multiple quantum wells with the type I band alignment for high emission efficiency. The vertical tunneling field-effect transistor for next-generation electronics depends on nearly broken-gap band alignment for boosting its performance. To tailor these 2D layered materials toward possible future applications, the understanding of 2D heterostructure band alignment becomes critically important. In the first part of this thesis, we discuss the band alignment of 2D heterostructures. To do so, we firstly study the interlayer coupling between two dissimilar 2D materials. We conclude that a post-anneal process could enhance the interlayer coupling of as-transferred 2D heterostructures, and heterostructural stacking imposes similar symmetry changes as homostructural stacking. Later, we precisely determine the quasi particle bandgap and band alignment of the MoS2/WSe2 heterostructure by using scan tunneling microscopy/spectroscopy (STM/S) and micron-beam X-ray photoelectron spectroscopy (μ-XPS) techniques. Lastly, we prove that the band alignment of 2D heterojunctions can be accurately predicted by Anderson’s model, which has previously failed to predict conventional bulk heterostructures. In the second part of this thesis, we develop a new Chemical Vapor Deposition (CVD) method capable of precisely controlling the growth area of p- and n-type transition metal dichalcogenides (TMDCs) and further form lateral or vertical 2D heterostructures. This

Pair Fermi contour and high-temperature superconductivity

CERN Document Server

Belyavsky, V I

2002-01-01

The holes superconducting coupling with the pair high summarized pulse and the relative motion low pulses is considered with an account of the quasi-two-dimensional electron structure of the HTSC-cuprates with the clearly-pronounced nesting of the Fermi contour. The superconducting energy gap and the condensation energy are determined and their dependences on the doping level are qualitatively studied. It is shown that the energy gap takes place in some holes concentration area, limited on both sides. The superconducting state, whereby the condensation energy is positive, originates in the more narrower doping interval inside this area. The hole pair redistribution in the pulse space constitutes the cause of the superconducting state origination by the holes repulsive screened Coulomb interaction. The coupling mechanism discussed hereby, males it possible to explain qualitatively not only the phase diagram basic peculiarities but also the key experimental facts, related to the cuprate HTSC-materials

On the restoration of symmetry in paired Fermion systems

International Nuclear Information System (INIS)

Flocard, H.

1997-01-01

We consider the problem of symmetry restoration as treated by the method of variation after projection (VAP) on good quantum numbers. We show that for compact groups, the convergence of the connected-linked expansion of the VAP kernels over the physically relevant interval of integration of the pairing gauge angle is not guaranteed. We propose instead a method which generates approximations of increasing precision which are periodic with respect to the gauge angle while differing from truncations of the Fourier expansion of the VAP kernels. For the projection on good particle number in paired fermion systems, this new approach is shown to be equivalent to an expansion in powers of the pairing tensor. For the lowest order approximation, an analytical integration over the gauge angle is performed explicitly. It provides the algebraic forms of the single particle Hamiltonian and of the pairing field entering generalized Hartree endash Fock endash Bogoljubov equations. Contrary to most approximations, the validity of the expressions for the energy and mean values of operators thus obtained is not a priori restricted where the fluctuation of the operator associated with the broken symmetry is large. We also derive the first-order correction to the pairing-order parameter. We test the quality of the proposed method on a non-trivial soluble model. copyright 1997 Academic Press, Inc

Identical gamma-vibrational bands in {sup 165}Ho

Energy Technology Data Exchange (ETDEWEB)

Radford, D.C.; Galindo-Uribarri, A.; Janzen, V.P. [Chalk River Labs., Ontario (Canada)] [and others

1996-12-31

The structure of {sup 165}Ho at moderate spins has been investigated by means of Coulomb excitation. Two {gamma}-vibrational bands (K{sup {pi}} = 11/2{sup {minus}} and K{sup {pi}} = 3/2{sup {minus}}) are observed, with very nearly identical in-band {gamma}-ray energies. Gamma-ray branching ratios are analyzed to extract information on Coriolis mixing, and the role of the K quantum number in identical bands is discussed.

Observing Pair-Work Task in an English Speaking Class

Science.gov (United States)

Achmad, Diana; Yusuf, Yunisrina Qismullah

2014-01-01

This paper reports on students' pair-work interactions to develop their speaking skills in an ELT classroom which consisted of international learners. A number of 16 learners of intermediate proficiency with IELTS score band 5.5 were observed. The teacher had paired those he considered among them to be the more competent ones (hereafter, stronger)…

Random-phase approximation and broken symmetry

International Nuclear Information System (INIS)

Davis, E.D.; Heiss, W.D.

1986-01-01

The validity of the random-phase approximation (RPA) in broken-symmetry bases is tested in an appropriate many-body system for which exact solutions are available. Initially the regions of stability of the self-consistent quasiparticle bases in this system are established and depicted in a 'phase' diagram. It is found that only stable bases can be used in an RPA calculation. This is particularly true for those RPA modes which are not associated with the onset of instability of the basis; it is seen that these modes do not describe any excited state when the basis is unstable, although from a formal point of view they remain acceptable. The RPA does well in a stable broken-symmetry basis provided one is not too close to a point where a phase transition occurs. This is true for both energies and matrix elements. (author)

B (E2) values of transitions from kπ= 0+→ 2+ vibrational bands in some well deformed heavy nuclei

International Nuclear Information System (INIS)

Singh, M.; Varshney, Mani; Gupta, D.K.; Bihari, Chhail; Singh, Yuvraj; Varshney, A.K.; Gupta, K.K

2009-01-01

There is simultaneous reduced B (E2) values of low-lying K π= 0 + → 2 + states, indicating a beta vibration like structure as well as the two particle transfer cross-section which suggest a pairing vibration like character and interpreted that low-lying k π= 0 + → 2 + resonance are classical beta vibrations. Recently, similar doubts about the origin of beta vibrations from surface oscillation have also been published

Frozen and broken color: a matrix Schroedinger equation in the semiclassical limit

International Nuclear Information System (INIS)

Orbach, H.S.

1981-01-01

We consider the case of frozen color, i.e, where global color symmetry remains exact, but where colored states have a mass large compared to color-singlet mesons. Using semiclassical WKB formalism, we construct the spectrum of bound states. In order to determine the charge of the constituents, we then consider deep-inelastic scattering of an external probe (e.g., lepton) from our one-dimensional meson. We calculate explicitly the structure function, W, in the WKB limit and show how Lipkin's mechanism is manifested, as well as how scaling behavior comes. We derive the WKB formalism as a special case of a method of obtaining WKB type solutions for generalized Schroedinger equations for which the Hamiltonian is an arbitrary matrix function of any number of pairs of canonical operators. We generalize these considerations to the case of broken color symmetry - but where the breaking is not so strong as to allow low-lying states to have a large amount of mixing with the colored states. In this case, the degeneracy of excited colored states can be broken. We find that local excitation of color guarantees global excitation of color; i.e., if at a given energy colored semiclassical states can be constructed with size comparable to that of the ground state wave function, colored states of that energy will also exist in the spectrum of the full theory and will be observed. However, global existence of color does not guarantee the excitation of colored states via deep-inelastic processes

A new low-cost 10 ns pulsed K(a)-band radar.

Science.gov (United States)

Eskelinen, Pekka; Ylinen, Juhana

2011-07-01

Two Gunn oscillators, conventional intermediate frequency building blocks, and a modified GaAs diode detector are combined to form a portable monostatic 10 ns instrumentation radar for outdoor K(a)-band radar cross section measurements. At 37.8 GHz the radar gives +20 dBm output power and its tangential sensitivity is -76 dBm. Processing bandwidth is 125 MHz, which also allows for some frequency drift in the Gunn devices. Intra-pulse frequency chirp is less than 15 MHz. All functions are steered by a microcontroller. First measurements convince that the construction has a reasonable ability to reduce close-to-ground surface clutter and gives an effective way of resolving target detail. This is beneficial especially when amplitude fluctuations disturb measurements with longer pulses. The new unit operates on 12 V dc, draws a current of less than 3 A, and weighs 5 kg.

High-Q Tl2CaBa2Cu2O8 high-Tc superconducting quasi-optical millimeter-wave bandpass filters working at 77 K

International Nuclear Information System (INIS)

Zhang, D.; Fetterman, H.R.

1994-01-01

Tl 2 CaBa 2 Cu 2 O 8 high-temperature superconducting thin films with T c 's of over 100 K on LaAlO 3 substrates were used to fabricate quasi-optical millimeter-wave bandpass filters. Q-factors of over 400 were achieved, at liquid nitrogen temperatures from these filters at W-band frequencies (75--110 GHz)

Schrödinger operators on a periodically broken zigzag carbon ...

Indian Academy of Sciences (India)

In this paper, we study the spectra of Schrödinger operators on zigzag carbon nanotubes, which are broken by abrasion or during refining process. Throughout this paper, we assume that the carbon nanotubes are broken periodically and we deal with one of those models. Making use of the Floquet–Bloch theory, we ...

Fractal Based Triple Band High Gain Monopole Antenna

Science.gov (United States)

Pandey, Shashi Kant; Pandey, Ganga Prasad; Sarun, P. M.

2017-10-01

A novel triple-band microstrip fed planar monopole antenna is proposed and investigated. A fractal antenna is created by iterating a narrow pulse (NP) generator model at upper side of modified ground plane, which has a rhombic patch, for enhancing the bandwidth and gain. Three iterations are carried out to study the effects of fractal geometry on the antenna performance. The proposed antenna can operate over three frequency ranges viz, 3.34-4.8 GHz, 5.5-10.6 GHz and 13-14.96 GHz suitable for WLAN 5.2/5.8 GHz, WiMAX 3.5/5.5 GHz and X band applications respectively. Simulated and measured results are in good agreements with each others. Results show that antenna provides wide/ultra wide bandwidths, monopole like radiation patterns and very high antenna gains over the operating frequency bands.

Study of High Mass Electron Pairs and High pT Phenomena

CERN Multimedia

2002-01-01

This experiment involves a modification of the apparatus used in R108, which extends the region of photon and electron detection to the entire azimuth, complementing the full azimuth charged particle detection already available. A five-fold increase in the acceptance for high mass e|+e|- pairs is thus achieved; the study of jets is also improved by extending the region of @g and @p|0 detection. An active converter consisting of lead glass and followed by a cathode strip read out MWPC is placed in front of each of the R108 lead glass arrays to improve @g/@p|0 discrimination. The modified apparatus is shown in the Figure. The specific physics aims of the experiment are: \\item 1) Search for high mass states decaying into e|+e|-. In a 3000-hour run the sensitivity is 2\\% of the @U cross-section for 10 detected events. \\item 2) Study of e|+e|- pair production above the @U mass. As well as the cross-section, the transverse momentum and rapidity distributions will be measured, providing a crucial test of QCD as appl...

Simple Technique for Removing Broken Pedicular Screws

Directory of Open Access Journals (Sweden)

A Agrawal

2014-03-01

Full Text Available The procedure for removing a broken pedicle screw should ideally be technically easy and minimally invasive, as any damage to the pedicle, during removal of the broken screw, may weaken the pedicle, thus compromising on the success of re-instrumentation. We describe the case of a 32-year old man who had undergone surgery for traumatic third lumbar vertebral body fracture three years prior to current admission and had developed the complication of pedicle screw breakage within the vertebral body. The patient underwent re-exploration and removal of the distal screws. Through a paravertebral incision and muscle separation, the screws and rods were exposed and the implants were removed.

Unbroken versus broken mirror world: a tale of two vacua

International Nuclear Information System (INIS)

Foot, R.; Lew, H.; Volkas, R.R.

2000-01-01

If the Lagrangian of nature respects parity invariance then there are two distinct possibilities: either parity is unbroken by the vacuum or it is spontaneously broken. We examine the two simplest phenomenologically consistent gauge models which have unbroken and spontaneously broken parity symmetries, respectively. These two models have a Lagrangian of the same form, but a different parameter range is chosen in the Higgs potential. They both predict the existence of dark matter and can explain the MACHO events. However, the models predict quite different neutrino physics. Although both have light mirror (effectively sterile) neutrinos, the ordinary-mirror neutrino mixing angles are unobservably tiny in the broken parity case. The minimal broken parity model therefore cannot simultaneously explain the solar, atmospheric and LSND data. By contrast, the unbroken parity version can explain all of the neutrino anomalies. Furthermore, we argue that the unbroken case provides the most natural explanation of the neutrino physics anomalies (irrespective of whether evidence from the LSND experiment is included) because of its characteristic maximal mixing prediction. (author)

Superconducting properties of the η-pairing state in the Penson-Kolb-Hubbard model

International Nuclear Information System (INIS)

Czart, W.R.; Robaszkiewicz, S.

2004-01-01

The Penson-Kolb-Hubbard model, i.e. the Hubbard model with the pair-hopping interaction J is studied. We focus on the properties of the superconducting state with the Cooper-pair center-of mass momentum q Q(η-phase). The transition into the η-phase, which is favorized by the repulsive J (J c |, dependent on band filling, on-site interaction U and band structure, and the system never exhibits standard BCS-like features. This is in obvious contrast with the properties of the isotropic s-wave state, stabilized by the attractive J and attractive U, which exhibit at T = 0 a smooth crossover from the BCS-like limit to that of tightly bound pairs with increasing pairing strength. (author)

On adiabatic pair potentials of highly charged colloid particles

Science.gov (United States)

Sogami, Ikuo S.

2018-03-01

Generalizing the Debye-Hückel formalism, we develop a new mean field theory for adiabatic pair potentials of highly charged particles in colloid dispersions. The unoccupied volume and the osmotic pressure are the key concepts to describe the chemical and thermodynamical equilibrium of the gas of small ions in the outside region of all of the colloid particles. To define the proper thermodynamic quantities, it is postulated to take an ensemble averaging with respect to the particle configurations in the integrals for their densities consisting of the electric potential satisfying a set of equations that are derived by linearizing the Poisson-Boltzmann equation. With the Fourier integral representation of the electric potential, we calculate first the internal electric energy of the system from which the Helmholtz free energy is obtained through the Legendre transformation. Then, the Gibbs free energy is calculated using both ways of the Legendre transformation with respect to the unoccupied volume and the summation of chemical potentials. The thermodynamic functions provide three types of pair potentials, all of which are inversely proportional to the fraction of the unoccupied volume. At the limit when the fraction factor reduces to unity, the Helmholtz pair potential turns exactly into the well known Derjaguin-Landau-Verwey-Overbeek repulsive potential. The Gibbs pair potential possessing a medium-range strong repulsive part and a long-range weak attractive tail can explain the Schulze-Hardy rule for coagulation in combination with the van der Waals-London potential and describes a rich variety of phenomena of phase transitions observed in the dilute dispersions of highly charged particles.

Underlying physics of identical odd- and even-mass bands in normally deformed rare-earth nuclei

International Nuclear Information System (INIS)

Yu Lei; Liu Shuxin; Lei Yian; Zeng Jinyan

2001-01-01

The microscopic mechanism of the identical odd- and even-mass number nuclear bands in normally deformed rare-earth nuclei was investigated using the particle-number conserving (PNC) method for treating nuclear pairing correlation. It was found that the odd particle of an odd-A identical band always occupied a cranked low j and high Ω Nilsson orbital (e.g. proton [404]7/2, [402]5/2. On the contrary, if the odd particle occupies an intruder high j orbital (e.g. neutron [633]7/2, proton[514]9/2), the moment of inertia of the odd-A band was much larger than that of neighboring even-even ground state band. The observed variation of moment of inertia (below band crossing) was reproduced quite well by the PNC calculation, in which no free parameter was involved. The strengths of monopole and Y 20 quadrupole interactions were determined by the experimental odd-even differences in binding energy and band head moment of inertia

High-energy band structure of gold

DEFF Research Database (Denmark)

Christensen, N. Egede

1976-01-01

The band structure of gold for energies far above the Fermi level has been calculated using the relativistic augmented-plane-wave method. The calculated f-band edge (Γ6-) lies 15.6 eV above the Fermi level is agreement with recent photoemission work. The band model is applied to interpret...

K{sub 2}MnF{sub 5}·H{sub 2}O as reactant for synthesizing highly efficient red emitting K{sub 2}TiF{sub 6}:Mn{sup 4+} phosphors by a modified cation exchange approach

Energy Technology Data Exchange (ETDEWEB)

Han, Tao, E-mail: danbaiht@126.com; Wang, Jun; Lang, Tianchun; Tu, Mingjing; Peng, Lingling

2016-11-01

As reactant for synthesizing K{sub 2}TiF{sub 6}:Mn{sup 4+} phosphors, the cross-shaped and cuboid-shaped K{sub 2}MnF{sub 5}·H{sub 2}O powders were prepared by the simple chemical method. Based on the reaction mechanism, oxidizing K{sub 2}MnF{sub 5}·H{sub 2}O (Mn{sup 3+}) to Mn{sup 4+} by KMnO{sub 4} (Mn{sup 7+}), a modified cation exchange approach for synthesizing highly efficient red emitting K{sub 2}TiF{sub 6}:Mn{sup 4+} phosphor was proposed. The obtained K{sub 2}TiF{sub 6}:Mn{sup 4+} (2.7–5.3 at.%) phosphors have the size of 30–80 μm with a rough surface, their emission spectra consist of five narrow bands extending from 580 to 660 nm with the strongest peak at 634.8 nm, whose relative emitting intensity depends on the molar ratio of KMnO{sub 4} to K{sub 2}MnF{sub 5}·H{sub 2}O (the platform value = 3.2), and two broad excitation bands are peaking at ∼365 nm and ∼460 nm. The internal quantum yield of our synthesized K{sub 2}TiF{sub 6}:Mn{sup 4+} phosphors is up to 82.5%, which is higher than the commercial CaAlSiN{sub 3}:Eu{sup 2+} value, their excitation bands peak at ∼460 and ∼365 nm are consistent with those of Y{sub 3}A{sub 5}O{sub 12}:Ce{sup 3+} phosphors and their emission bands are more suitable for the sensitivity curve of photopic human vision. In addition, our synthesized phosphors show better thermal quenching properties. These findings show a large potential of the synthesized K{sub 2}TiF{sub 6}:Mn{sup 4+} phosphors for commercialization. - Highlights: • We synthesize the cross-shaped and cuboid-shaped K{sub 2}MnF{sub 5}·H{sub 2}O. • K{sub 2}MnF{sub 5}·H{sub 2}O is as a reactant for synthesizing K{sub 2}TiF{sub 6}:Mn{sup 4+} phosphors. • K{sub 2}TiF{sub 6}:Mn{sup 4+} will improve the current white LED with high CRI for indoor lighting.

Total Domination Versus Paired-Domination in Regular Graphs

Directory of Open Access Journals (Sweden)

Cyman Joanna

2018-05-01

Full Text Available A subset S of vertices of a graph G is a dominating set of G if every vertex not in S has a neighbor in S, while S is a total dominating set of G if every vertex has a neighbor in S. If S is a dominating set with the additional property that the subgraph induced by S contains a perfect matching, then S is a paired-dominating set. The domination number, denoted γ(G, is the minimum cardinality of a dominating set of G, while the minimum cardinalities of a total dominating set and paired-dominating set are the total domination number, γt(G, and the paired-domination number, γpr(G, respectively. For k ≥ 2, let G be a connected k-regular graph. It is known [Schaudt, Total domination versus paired domination, Discuss. Math. Graph Theory 32 (2012 435–447] that γpr(G/γt(G ≤ (2k/(k+1. In the special case when k = 2, we observe that γpr(G/γt(G ≤ 4/3, with equality if and only if G ≅ C5. When k = 3, we show that γpr(G/γt(G ≤ 3/2, with equality if and only if G is the Petersen graph. More generally for k ≥ 2, if G has girth at least 5 and satisfies γpr(G/γt(G = (2k/(k + 1, then we show that G is a diameter-2 Moore graph. As a consequence of this result, we prove that for k ≥ 2 and k ≠ 57, if G has girth at least 5, then γpr(G/γt(G ≤ (2k/(k +1, with equality if and only if k = 2 and G ≅ C5 or k = 3 and G is the Petersen graph.

Perilaku Komunikasi antara Guru dengan Siswa Broken Home

Directory of Open Access Journals (Sweden)

Emilsyah Nur

2017-12-01

Full Text Available Penelitian yang dilakukan merupakan penelitian kualitatif yang menggunakan beberapa informan sebagai narasumber untuk menjawab permasalahan tentang opini publik terhadap komunikasi interpersonal dalam mengatasi orang tua broken home. Hasil penelitian menunjukkan bahwa perilaku komunikasi siswa broken home di sekolah belum sepenuhnya efektif. Hal ini disebabkan oleh: intensitas komunikasi antara orang tua dan anak yang masih kurang sehingga anak enggan untuk terbuka kepada orang tuanya mengenai prestasi belajar. Kurangnya dukungan, rasa empati serta sikap positif yang diberikan orang tua kepada anak juga mempengaruhi hubungan interpersonal diantara orang tua dan anak yang menyebabkan anak lebih terbuka kepada teman atau kerabatnya daripada orang tuanya sendiri.Kesetaraan antara orang tua dan anak masih kurang. Perilaku komunikasi yang demikian sangat berpengaruh terhadap perilaku anak di sekolah. Beberapa faktor yang menghambat prilaku komunikasi siswa broken home  diantaranya yaitu  orang tua yang kurang bisa membagi waktu antara pekerjaan dan memberikan perhatian kepada anak di rumah sehingga komunikasi dengan anak tidak berjalan dengan lancar, sikap acuh tak acuh yang ditunjukkan orang tua membuat anak menjauhkan diri dan tidak terbuka kepada orang tua dan ketidakterbukaan siswa terhadap Guru.

Quantum Multicriticality near the Dirac-Semimetal to Band-Insulator Critical Point in Two Dimensions: A Controlled Ascent from One Dimension

Science.gov (United States)

Roy, Bitan; Foster, Matthew S.

2018-01-01

We compute the effects of generic short-range interactions on gapless electrons residing at the quantum critical point separating a two-dimensional Dirac semimetal and a symmetry-preserving band insulator. The electronic dispersion at this critical point is anisotropic (Ek=±√{v2kx2+b2ky2 n } with n =2 ), which results in unconventional scaling of thermodynamic and transport quantities. Because of the vanishing density of states [ϱ (E )˜|E |1 /n ], this anisotropic semimetal (ASM) is stable against weak short-range interactions. However, for stronger interactions, the direct Dirac-semimetal to band-insulator transition can either (i) become a fluctuation-driven first-order transition (although unlikely in a particular microscopic model considered here, the anisotropic honeycomb lattice extended Hubbard model) or (ii) get avoided by an intervening broken-symmetry phase. We perform a controlled renormalization group analysis with the small parameter ɛ =1 /n , augmented with a 1 /n expansion (parametrically suppressing quantum fluctuations in the higher dimension) by perturbing away from the one-dimensional limit, realized by setting ɛ =0 and n →∞ . We identify charge density wave (CDW), antiferromagnet (AFM), and singlet s -wave superconductivity as the three dominant candidates for broken symmetry. The onset of any such order at strong coupling (˜ɛ ) takes place through a continuous quantum phase transition across an interacting multicritical point, where the ordered phase, band insulator, Dirac, and anisotropic semimetals meet. We also present the phase diagram of an extended Hubbard model for the ASM, obtained via the controlled deformation of its counterpart in one dimension. The latter displays spin-charge separation and instabilities to CDW, spin density wave, and Luther-Emery liquid phases at arbitrarily weak coupling. The spin density wave and Luther-Emery liquid phases deform into pseudospin SU(2)-symmetric quantum critical points separating the

Investigation of 6T SRAM memory circuit using high-k dielectrics based nano scale junctionless transistor

Science.gov (United States)

Charles Pravin, J.; Nirmal, D.; Prajoon, P.; Mohan Kumar, N.; Ajayan, J.

2017-04-01

In this paper the Dual Metal Surround Gate Junctionless Transistor (DMSGJLT) has been implemented with various high-k dielectric. The leakage current in the device is analysed in detail by obtaining the band structure for different high-k dielectric material. It is noticed that with increasing dielectric constant the device provides more resistance for the direct tunnelling of electron in off state. The gate oxide capacitance also shows 0.1 μF improvement with Hafnium Oxide (HfO2) than Silicon Oxide (SiO2). This paved the way for a better memory application when high-k dielectric is used. The Six Transistor (6T) Static Random Access Memory (SRAM) circuit implemented shows 41.4% improvement in read noise margin for HfO2 than SiO2. It also shows 37.49% improvement in write noise margin and 30.16% improvement in hold noise margin for HfO2 than SiO2.

Broken symmetries at high temperatures and the problem of baryon excess of the universe

International Nuclear Information System (INIS)

Mohapatra, R.N.; Senjanovic, G.

1979-06-01

A class of gauge theories, where spontaneously broken symmetries, instead of being restored, persist as the temperature is increased is discussed. A renormalization group analysis of this phenomena suggests that there may be more than one phase transition in these models with at least one symmetric phase. Applying these ideas to the specific case of soft CP-violation in grand unified theories, a mechanism to generate the baryon to entropy ratio of the universe is discussed. 34 references

Quasiparticle band structure of rocksalt-CdO determined using maximally localized Wannier functions.

Science.gov (United States)

Dixit, H; Lamoen, D; Partoens, B

2013-01-23

CdO in the rocksalt structure is an indirect band gap semiconductor. Thus, in order to determine its band gap one needs to calculate the complete band structure. However, in practice, the exact evaluation of the quasiparticle band structure for the large number of k-points which constitute the different symmetry lines in the Brillouin zone can be an extremely demanding task compared to the standard density functional theory (DFT) calculation. In this paper we report the full quasiparticle band structure of CdO using a plane-wave pseudopotential approach. In order to reduce the computational effort and time, we make use of maximally localized Wannier functions (MLWFs). The MLWFs offer a highly accurate method for interpolation of the DFT or GW band structure from a coarse k-point mesh in the irreducible Brillouin zone, resulting in a much reduced computational effort. The present paper discusses the technical details of the scheme along with the results obtained for the quasiparticle band gap and the electron effective mass.

Coexisting shape- and high-K isomers in the shape transitional nucleus {sup 188}Pt

Energy Technology Data Exchange (ETDEWEB)

Mukhopadhyay, S., E-mail: somm@barc.gov.in [Nuclear Physics Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400085 (India); Biswas, D.C. [Nuclear Physics Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400085 (India); Tandel, S.K. [UM-DAE Centre for Excellence in Basic Sciences, Mumbai 400098 (India); Danu, L.S.; Joshi, B.N.; Prajapati, G.K. [Nuclear Physics Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400085 (India); Nag, Somnath [Dept. of Physics, IIT Kharagpur, Kharagpur 721302 (India); Trivedi, T.; Saha, S.; Sethi, J.; Palit, R. [Dept. of Nuclear and Atomic Physics, TIFR, Mumbai 400005 (India); Joshi, P.K. [Homi Bhabha Centre for Science Education, TIFR, Mumbai 400088 (India)

2014-12-12

A high-spin study of the shape transitional nucleus {sup 188}Pt reveals the unusual coexistence of both shape- and K-isomeric states. Reduced B(E2) transition probabilities for decays from these states inferred from the data clearly establish their hindered character. In addition to other excited structures, a rotational band built upon the K isomer is identified, and its configuration has been assigned through an analysis of alignments and branching ratios. The shape evolution with spin in this nucleus has been inferred from both experimental observables and cranking calculations. The yrast positive parity structure appears to evolve from a near-prolate deformed shape through triaxial at intermediate excitation, and eventually to oblate at the highest spins.

Functional and effective whole brain connectivity using magnetoencephalography to identify monozygotic twin pairs.

Science.gov (United States)

Demuru, M; Gouw, A A; Hillebrand, A; Stam, C J; van Dijk, B W; Scheltens, P; Tijms, B M; Konijnenberg, E; Ten Kate, M; den Braber, A; Smit, D J A; Boomsma, D I; Visser, P J

2017-08-29

Resting-state functional connectivity patterns are highly stable over time within subjects. This suggests that such 'functional fingerprints' may have strong genetic component. We investigated whether the functional (FC) or effective (EC) connectivity patterns of one monozygotic twin could be used to identify the co-twin among a larger sample and determined the overlap in functional fingerprints within monozygotic (MZ) twin pairs using resting state magnetoencephalography (MEG). We included 32 cognitively normal MZ twin pairs from the Netherlands Twin Register who participate in the EMIF-AD preclinAD study (average age 68 years). Combining EC information across multiple frequency bands we obtained an identification rate over 75%. Since MZ twin pairs are genetically identical these results suggest a high genetic contribution to MEG-based EC patterns, leading to large similarities in brain connectivity patterns between two individuals even after 60 years of life or more.

Superdeformed bands in /sup 150/Gd and /sup 151/Tb: Evidence for the influence of high-N intruder states at large deformations

Energy Technology Data Exchange (ETDEWEB)

Fallon, P.; Alderson, A.; Bentley, M.A.; Bruce, A.M.; Forsyth, P.D.; Howe, D.; Roberts, J.W.; Sharpey-Schafer, J.F.; Twin, P.J.; Beck, F.A.

1989-02-16

Rotational bands, characteristic of a superdeformed prolate shape (epsilon approx. = 0.6) and extending to above spin 60 Planck constant, have been observed in both /sup 150/Gd and /sup 151/Tb. The magnitudes of the moments of inertia I/sup (2)/ were found to vary with frequency and the variation greatly exceeded that seen in /sup 148,149/Gd and /sup 151,152/Dy. The differences in the I/sup (2)/'s are attributed to the occupation of particular high-N orbitals. Moreover, contrary to the previous examples the bands in both /sup 150/Gd and /sup 151/Tb de-excited at a much higher rotational frequency of Planck constant..omega.. approx. = 0.4 MeV and this may indicate that the pair gap extends to higher frequencies in /sup 150/Gd and /sup 151/Tb.

Elastoconductivity as a probe of broken mirror symmetries

Energy Technology Data Exchange (ETDEWEB)

Hlobil, Patrik; Maharaj, Akash V.; Hosur, Pavan; Shapiro, M. C.; Fisher, I. R.; Raghu, S.

2015-07-27

We propose the possible detection of broken mirror symmetries in correlated two-dimensional materials by elastotransport measurements. Using linear response theory we calculate the“shear conductivity” Γ x x , x y , defined as the linear change of the longitudinal conductivity σ x x due to a shear strain ε x y . This quantity can only be nonvanishing when in-plane mirror symmetries are broken and we discuss how candidate states in the cuprate pseudogap regime (e.g., various loop current or charge orders) may exhibit a finite shear conductivity. We also provide a realistic experimental protocol for detecting such a response.

Design and analysis of X-band femtosecond linac

Energy Technology Data Exchange (ETDEWEB)

Uesaka, M; Kozawa, T; Takeshita, A; Kobayashi, T; Ueda, T; Miya, K [Tokyo Univ., Tokai, Ibaraki (Japan). Nuclear Engineering Research Lab.

1997-03-01

Femtosecond quantum phenomena research project is proposed at Nuclear Engineering Research Laboratory, University of Tokyo. The research facility consists of an X-band (11.424GHz) femtosecond electron linac, a femtosecond wavelength tunable laser, two S-band (2.856GHz) picosecond electron linacs and measuring equipments. Especially, we aim to generate a 100 fs (FWHM) electron single bunch with more than 1 nC at the X-band femtosecond linac. Ultrafast processes in radiation physics, chemistry, material science and microscopic electromagnetic phenomena are going to be analyzed there. Here the design and analysis of an X-band femtosecond linac is presented. The simulation of electron dynamics is carried out including magnetic pulse compression by using PARMELA and SUPERFISH. It is found by the simulation that the 600 ps (tail-to-tail) electron emission from a 200 kV thermionic gun can be bunched and compressed to 110 fs (FWHM) with the charge of 0.8 nC which gives 7.3 kA. We plan to use one high power X-band klystron which can supply 60 MW with more than 200 ns pulse duration. The flatness of plateau of the pulse should be 0.2% for stable ultrashort bunch generation. (author)

Updating and test on 12 kA HTSCL for Russia JINR

International Nuclear Information System (INIS)

Zhou, Tingzhi; Ding, K; Liu, C; Xu, C; Feng, H; Wu, H; Liu, X; Song, Y

2014-01-01

The Joint Institute for Nuclear Research (JINR) started manufacture and test of superconducting magnets for the new accelerator complex Nuclotron-based Ion Collider fAcility (NICA). A pair of current leads rated 12 kA was developed for cold testing of the magnets in 2012. The operation of the facility needs ∼350 leads rated from 100 A to 12 kA to convey current for the magnets. After the test of the pair of 12 kA leads in JINR a contract of supplying 3 pairs of 12 kA high temperature superconducting current leads (HTSCLs) were signed to ASIPP this year. In this paper the design updating and test of the current leads are introduced.

Search for excited superdeformed bands in {sup 151}Dy

Energy Technology Data Exchange (ETDEWEB)

Nisius, D.; Janssens, R.V.F.; Crowell, B. [and others

1995-08-01

Following the first report of superdeformed (SD) bands with identical transition energies in the pairs ({sup 151}Tb*,{sup 152}Dy), ({sup 150}Gd*, {sup 151}Tb) and ({sup 153}Dy*, {sup 152}Dy) (where * denotes an excited SD band), it was proposed by Nazarewicz et al. that the observations could be understood in a strong-coupling approach if pseudo SU(3) symmetry were invoked. In this model there are three limiting values of the decoupling parameter; i.e. a = 0, {plus_minus}1. In the first two cases mentioned above the pairs of bands have nearly identical transition energies and are interpreted as proton excitations involving the [200]1/2 pseudospin orbital coupled to the {sup 152}Dy core, for which the value of the decoupling parameter is calculated to be a =+1.

K isomers as probes of nuclear structure

Science.gov (United States)

Tandel, S. K.

2014-08-01

K isomers are studied in Pu and Cm isotopes, and also in Hf and W nuclei. Many high-K states, several of which are isomeric, are identified. Lifetime measurements spanning the ns-s range have been performed, and decay paths of isomers established. Rotational bands built on high-K states are also identified in many cases. Isomer decays are considerably hindered in many instances, both in the A≈180 and 250 regions indicating that K is an approximately conserved quantum number. High-K states become the favored excitation mode at high spins in the A≈180 region. The energies of the 2-quasiparticle high-K states in Cm isotopes suggest the presence of a deformed subshell gap at N=152.

K isomers as probes of nuclear structure

Energy Technology Data Exchange (ETDEWEB)

Tandel, S. K., E-mail: sujit.tandel@cbs.ac.in [UM-DAE Centre for Excellence in Basic Sciences, Mumbai 400098 (India)

2014-08-14

K isomers are studied in Pu and Cm isotopes, and also in Hf and W nuclei. Many high-K states, several of which are isomeric, are identified. Lifetime measurements spanning the ns-s range have been performed, and decay paths of isomers established. Rotational bands built on high-K states are also identified in many cases. Isomer decays are considerably hindered in many instances, both in the A≈180 and 250 regions indicating that K is an approximately conserved quantum number. High-K states become the favored excitation mode at high spins in the A≈180 region. The energies of the 2-quasiparticle high-K states in Cm isotopes suggest the presence of a deformed subshell gap at N=152.

Holography with broken Poincaré symmetry

NARCIS (Netherlands)

Korovins, J.

2014-01-01

This thesis deals with the extensions of the holographic dualities to the situations where part of the Poincaré group has been broken. Such theories are particularly relevant for applications of gauge/gravity dualities to condensed matter systems, which usually exhibit non-relativistic symmetry.

Band structure and orbital character of monolayer MoS2 with eleven-band tight-binding model

Science.gov (United States)

Shahriari, Majid; Ghalambor Dezfuli, Abdolmohammad; Sabaeian, Mohammad

2018-02-01

In this paper, based on a tight-binding (TB) model, first we present the calculations of eigenvalues as band structure and then present the eigenvectors as probability amplitude for finding electron in atomic orbitals for monolayer MoS2 in the first Brillouin zone. In these calculations we are considering hopping processes between the nearest-neighbor Mo-S, the next nearest-neighbor in-plan Mo-Mo, and the next nearest-neighbor in-plan and out-of-plan S-S atoms in a three-atom based unit cell of two-dimensional rhombic MoS2. The hopping integrals have been solved in terms of Slater-Koster and crystal field parameters. These parameters are calculated by comparing TB model with the density function theory (DFT) in the high-symmetry k-points (i.e. the K- and Γ-points). In our TB model all the 4d Mo orbitals and the 3p S orbitals are considered and detailed analysis of the orbital character of each energy level at the main high-symmetry points of the Brillouin zone is described. In comparison with DFT calculations, our results of TB model show a very good agreement for bands near the Fermi level. However for other bands which are far from the Fermi level, some discrepancies between our TB model and DFT calculations are observed. Upon the accuracy of Slater-Koster and crystal field parameters, on the contrary of DFT, our model provide enough accuracy to calculate all allowed transitions between energy bands that are very crucial for investigating the linear and nonlinear optical properties of monolayer MoS2.

Performance of high-resolution X-band radar for rainfall measurement in The Netherlands

Directory of Open Access Journals (Sweden)

C. Z. van de Beek

2010-02-01

Full Text Available This study presents an analysis of 195 rainfall events gathered with the X-band weather radar SOLIDAR and a tipping bucket rain gauge network near Delft, The Netherlands, between May 1993 and April 1994. The aim of this paper is to present a thorough analysis of a climatological dataset using a high spatial (120 m and temporal (16 s resolution X-band radar. This makes it a study of the potential for high-resolution rainfall measurements with non-polarimetric X-band radar over flat terrain. An appropriate radar reflectivity – rain rate relation is derived from measurements of raindrop size distributions and compared with radar – rain gauge data. The radar calibration is assessed using a long-term comparison of rain gauge measurements with corresponding radar reflectivities as well as by analyzing the evolution of the stability of ground clutter areas over time. Three different methods for ground clutter correction as well as the effectiveness of forward and backward attenuation correction algorithms have been studied. Five individual rainfall events are discussed in detail to illustrate the strengths and weaknesses of high-resolution X-band radar and the effectiveness of the presented correction methods. X-band radar is found to be able to measure the space-time variation of rainfall at high resolution, far greater than what can be achieved by rain gauge networks or a typical operational C-band weather radar. On the other hand, SOLIDAR can suffer from receiver saturation, wet radome attenuation as well as signal loss along the path. During very strong convective situations the signal can even be lost completely. In combination with several rain gauges for quality control, high resolution X-band radar is considered to be suitable for rainfall monitoring over relatively small (urban catchments. These results offer great prospects for the new high resolution polarimetric doppler X-band radar IDRA.

W-Band Sheet Beam Klystron Design

International Nuclear Information System (INIS)

Scheitrum, G.; Caryotakis, G.; Burke, A.; Jensen, A.; Jongewaard, E.; Krasnykh, A.; Neubauer, M.; Phillips, R.; Rauenbuehler, K.

2011-01-01

Sheet beam devices provide important advantages for very high power, narrow bandwidth RF sources like accelerator klystrons (1). Reduced current density and increased surface area result in increased power capabi1ity, reduced magnetic fields for focusing and reduced cathode loading. These advantages are offset by increased complexity, beam formation and transport issues and potential for mode competition in the ovennoded cavities and drift tube. This paper will describe the design issues encountered in developing a 100 kW peak and 2 kW average power sheet beam k1ystron at W-band including beam formation, beam transport, circuit design, circuit fabrication and mode competition.

Role of the Band Gap for the Interaction Energy of Coadsorbed Fragments

DEFF Research Database (Denmark)

Castelli, Ivano Eligio; Man, Isabela-Costinela; Soriga, Stefan-Gabriel

2017-01-01

on semiconductors. We propose here a correlation between the cooperative interaction energy, i.e., the energy difference between the adsorption energies of coadsorbed electron donor–acceptor pair and isolated fragments and the band gap of the clean oxide surface. We demonstrate this effect for a number of oxides...... and donor–acceptor pairs and explain it with the shift in the Fermi level before and after the adsorption. The conclusion is that the adsorption of acceptor–donor pairs is considerably more favorable compared to unpaired fragments,and this energy difference is approximately equal to the value of the band...

The 5K70SK automatically tuned, high power, S-band klystron

Science.gov (United States)

Goldfinger, A.

1977-01-01

Primary objectives include delivery of 44 5K70SK klystron amplifier tubes and 26 remote tuner assemblies with spare parts kits. Results of a reliability demonstration on a klystron test cavity are discussed, along with reliability tests performed on a remote tuning unit. Production problems and one design modification are reported and discussed. Results of PAT and DVT are included.

K-homology and K-cohomology constructions of relations

International Nuclear Information System (INIS)

Abd El-Sattar, A. Dabbour; Bayoumy, F.M.

1990-08-01

One of the important homology (cohomology) theories, based on systems of covering of the space, is the homology (cohomology) theory of relations. In the present work, by using the idea of K-homology and K-cohomology groups different varieties of the Dowker's theory are introduced and studied. These constructions are defined on the category of pairs of topological spaces and over a pair of coefficient groups. (author). 14 refs

X-band uplink feedcone capabilities, components, and layout

Science.gov (United States)

Marlin, H.; Freiley, A.; Hartop, R.

1986-01-01

Two new X-(7.2 GHz up, 8.4 GHz down) and S-band (2.1 to 2.3 Ghz) common aperture (XSC) feedcones are being added to the DSS 45 and DSS 65 34-Meter Efficiency Antennas. These new feedcones are modifications of the existing SXC feedcone design incorporating a new high power (20-kW) X-band transmitter. The modified Antenna Microwave Subsystem design also incorporates two additional X-band low noise amplifiers and greater phase stability performance to meet both the increased stability requirements for Galileo gravity wave experiments and requirements for spacecraft navigation near the Sun. A third XSC will be constructed for DSS 15 later.

Spontaneously broken mass

International Nuclear Information System (INIS)

Endlich, Solomon; Nicolis, Alberto; Penco, Riccardo

2015-01-01

The Galilei group involves mass as a central charge. We show that the associated superselection rule is incompatible with the observed phenomenology of superfluid helium 4: this is recovered only under the assumption that mass is spontaneously broken. This remark is somewhat immaterial for the real world, where the correct space-time symmetries are encoded by the Poincaré group, which has no central charge. Yet it provides an explicit example of how superselection rules can be experimentally tested. We elaborate on what conditions must be met for our ideas to be generalizable to the relativistic case of the integer/half-integer angular momentum superselection rule.

Collectivity of dipole bands in {sup 196}Pb

Energy Technology Data Exchange (ETDEWEB)

Carpenter, M.P.; Liang, Y.; Janssens, R.V.F. [and others

1995-08-01

The region of nuclei with mass {approximately} 190 was studied extensively over the last few years following the discovery of superdeformation in {sup 190}Hg. More recently, considerable interest in the neutron-deficient Pb isotopes developed with the discover of a number of bands at high spin connected by dipole transitions in both even {sup 192-200}Pb and odd {sup 197-201}Pb nuclei. The majority of the dipole bands are regular in character (i.e. transition energies increase smoothly with spin) while the remaining bands are referred to as irregular in character, due to the fact that the transition energies do not increase smoothly with spin. The properties of the dipole bands were interpreted in terms of high-K, moderately-deformed oblate states built on configurations involving high-J, shape-driving quasiproton excitations coupled to rotation-aligned quasineutrons. It was suggested that the difference between the regular and irregular dipole sequences is related to the deformation where the irregular sequences are thought to be less collective than their regular counterparts.

Dual-band and high-efficiency polarization converter based on metasurfaces at microwave frequencies

Science.gov (United States)

Liu, Yajun; Xia, Song; Shi, Hongyu; Zhang, Anxue; Xu, Zhuo

2016-06-01

We present a dual-band and high-efficiency polarization converter in microwave regime. The proposed converter can convert a linearly polarized wave to its cross-polarized wave for two distinct bands: Ku (11.5-20.0 GHz) and Ka (28.8-34.0 GHz). It can also convert the linearly polarized wave to a circularly polarized wave at four other frequencies. The experimental results are in good agreement with simulation results for both frequency bands. The polarization conversion ratio is above 0.94 for the Ku-band and 0.90 for the Ka-band. Furthermore, the converter can achieve dual-band and high-efficiency polarization conversion over angles of incidence up to 45°. The converter is also polarization-selective in that only the x- and y-polarized waves can be converted. The physical mechanism of the dual-band polarization conversion effect is interpreted via decomposed electric field components that couple with different plasmon resonance modes of the structure.

Prediction of flexible/rigid regions from protein sequences using k-spaced amino acid pairs

Directory of Open Access Journals (Sweden)

Ruan Jishou

2007-04-01

characterized by accuracies below 70%. Finally, the Naïve Bayes method is shown to provide the highest sensitivity for the prediction of flexible regions, while FlexRP and SVM give the highest sensitivity for rigid regions. Conclusion A new sequence representation that uses k-spaced amino acid pairs is shown to be the most efficient in the prediction of the flexible/rigid regions of protein sequences. The proposed FlexRP method provides the highest prediction accuracy of about 80%. The experimental tests show that the FlexRP and SVM methods achieved high overall accuracy and the highest sensitivity for rigid regions, while the best quality of the predictions for flexible regions is achieved by the Naïve Bayes method.

Reconstruction of Band Structure Induced by Electronic Nematicity in an FeSe Superconductor

Science.gov (United States)

Nakayama, K.; Miyata, Y.; Phan, G. N.; Sato, T.; Tanabe, Y.; Urata, T.; Tanigaki, K.; Takahashi, T.

2014-12-01

We have performed high-resolution angle-resolved photoemission spectroscopy on an FeSe superconductor (Tc˜8 K ), which exhibits a tetragonal-to-orthorhombic structural transition at Ts˜90 K . At low temperature, we found splitting of the energy bands as large as 50 meV at the M point in the Brillouin zone, likely caused by the formation of electronically driven nematic states. This band splitting persists up to T ˜110 K , slightly above Ts, suggesting that the structural transition is triggered by the electronic nematicity. We have also revealed that at low temperature the band splitting gives rise to a van Hove singularity within 5 meV of the Fermi energy. The present result strongly suggests that this unusual electronic state is responsible for the unconventional superconductivity in FeSe.

Observation of muon-electron pairs in neutrino reactions

International Nuclear Information System (INIS)

Hoffmann, D.

1980-05-01

The present thesis describes the observation of muon-electron pairs in neutrino reactions. This experiment was performed using an optical multiplate spark chamber in the broad band neutrino beam of the CERN proton synchrotron. (orig.) [de

76 FR 6493 - Notice of Intent to Prepare an Environmental Impact Statement for the Proposed K Road/Moapa Band...

Science.gov (United States)

2011-02-04

... Impact Statement for the Proposed K Road/Moapa Band of Paiute Indians Photovoltaic Solar Facility, Clark... U.S.C. 415, is the BIA approval of a solar energy ground lease and associated agreements entered... proposed solar generation facility to an existing substation on a transmission line with a rating up to 500...

Investigation of color effects in lepton-pair collisions

International Nuclear Information System (INIS)

Kim, S.K.; Kim, Y.; Lee, H.K.

1980-01-01

The differential cross section of the high Psub(t) jet production is calculated using the equivalent-photon approximation in the framework of the broken color gauge symmetry theory to investigate color effects. The cross section is found to have no parameter at all. And the results are compared with that of the exact color symmetry and it is found that the cross section of the broken color symmetry is larger than that of the exact color symmetry theory. (author)

Detection of broken rotor bar faults in induction motor at low load using neural network.

Science.gov (United States)

Bessam, B; Menacer, A; Boumehraz, M; Cherif, H

2016-09-01

The knowledge of the broken rotor bars characteristic frequencies and amplitudes has a great importance for all related diagnostic methods. The monitoring of motor faults requires a high resolution spectrum to separate different frequency components. The Discrete Fourier Transform (DFT) has been widely used to achieve these requirements. However, at low slip this technique cannot give good results. As a solution for these problems, this paper proposes an efficient technique based on a neural network approach and Hilbert transform (HT) for broken rotor bar diagnosis in induction machines at low load. The Hilbert transform is used to extract the stator current envelope (SCE). Two features are selected from the (SCE) spectrum (the amplitude and frequency of the harmonic). These features will be used as input for neural network. The results obtained are astonishing and it is capable to detect the correct number of broken rotor bars under different load conditions. Copyright © 2016 ISA. Published by Elsevier Ltd. All rights reserved.

The Austin High School Girls' Band of Chicago, Illinois: 1925-1956

Science.gov (United States)

Hash, Phillip M.

2018-01-01

The purpose of this study was to examine the history of the Austin High School (AHS) Girls' Band (AHSGB) of Chicago, Illinois, which existed from 1925 to 1956. This research focused on the band's (a) organization and leadership, (b) activities within the school and community, (c) relationship to the AHS Boys Band, and (d) efforts to challenge and…

Charge transport of graphene ferromagnetic-insulator-superconductor junction with pairing state of broken time reversal symmetry

Directory of Open Access Journals (Sweden)

Yaser Hajati

2015-04-01

Full Text Available We investigate the charge transport through a graphene-based ferromagnetic-insulator-superconductor junction with a broken time reversal symmetry (BTRS of dx2−y2 + is and dx2−y2 + idxy superconductor using the extended Blonder-Tinkham-Klapwijk formalism. Our analysis have shown several charateristics in this junction, providing a useful probe to understand the role of the order parameter symmetry in the superconductivity. We find that the presence of the BTRS (X state in the superconductor region has a strong effect on the tunneling conductance curves which leads to a decrease in the height of the zero-bias conductance peak (ZBCP. In particular, we show that the magnitude of the superconducting proximity effect depends to a great extent on X and by increasing X, the zero-bias charge conductance oscillations with respect to the rotation angle β are suppressed. In addition, we find that at the maximum rotation angle β = π/4, introducing BTRS in the FIS junction causes oscillatory behavior of the zero-bias charge conductance with the barrier strength (χG by a period of π and by approaching the X to 1, the amplitude of charge conductance oscillations increases. This behavior is drastically different from none BTRS similar graphene junctions. At last, we suggest an experimental setup for verifying our predicted effects.

A Minimized MIMO-UWB Antenna with High Isolation and Triple Band-Notched Functions

Science.gov (United States)

Kong, Yuanyuan; Li, Yingsong; Yu, Kai

2016-11-01

A compact high isolation MIMO-UWB antenna with triple frequency rejection bands is proposed for UWB communication applications. The proposed MIMO-UWB antenna consists of two identical UWB antennas and each antenna element has a semicircle ring shaped radiation patch fed by a bend microstrip feeding line for covering the UWB band, which operates from 2.85 GHz to 11.79 GHz with an impedance bandwidth of 122.1 %. By etching a L-shaped slot on the ground plane, and embedding an "anchor" shaped stub into the patch and integrating an open ring under the semicircle shaped radiation patch, three notch bands are realized to suppress WiMAX (3.3-3.6 GHz), WLAN(5.725-5.825 GHz) and uplink of X-band satellite (7.9-8.4 GHz) signals. The high isolation with S21<-20 dB in most UWB band is obtained by adding a protruded decoupling structure. The design procedure of the MIMO-UWB antenna is given in detail. The proposed MIMO-UWB antenna is simulated, fabricated and measured. Experimental results demonstrate that the proposed MIMO-UWB antenna has a stable gain, good impedance match, high isolation, low envelope correlation coefficient and good radiation pattern at the UWB operating band and it can provide three designated notch bands.

Einstein-Podolsky-Rosen Entanglement of Narrow-Band Photons from Cold Atoms

Science.gov (United States)

Lee, Jong-Chan; Park, Kwang-Kyoon; Zhao, Tian-Ming; Kim, Yoon-Ho

2016-12-01

Einstein-Podolsky-Rosen (EPR) entanglement introduced in 1935 deals with two particles that are entangled in their positions and momenta. Here we report the first experimental demonstration of EPR position-momentum entanglement of narrow-band photon pairs generated from cold atoms. By using two-photon quantum ghost imaging and ghost interference, we demonstrate explicitly that the narrow-band photon pairs violate the separability criterion, confirming EPR entanglement. We further demonstrate continuous variable EPR steering for positions and momenta of the two photons. Our new source of EPR-entangled narrow-band photons is expected to play an essential role in spatially multiplexed quantum information processing, such as, storage of quantum correlated images, quantum interface involving hyperentangled photons, etc.

Einstein-Podolsky-Rosen Entanglement of Narrow-Band Photons from Cold Atoms.

Science.gov (United States)

Lee, Jong-Chan; Park, Kwang-Kyoon; Zhao, Tian-Ming; Kim, Yoon-Ho

2016-12-16

Einstein-Podolsky-Rosen (EPR) entanglement introduced in 1935 deals with two particles that are entangled in their positions and momenta. Here we report the first experimental demonstration of EPR position-momentum entanglement of narrow-band photon pairs generated from cold atoms. By using two-photon quantum ghost imaging and ghost interference, we demonstrate explicitly that the narrow-band photon pairs violate the separability criterion, confirming EPR entanglement. We further demonstrate continuous variable EPR steering for positions and momenta of the two photons. Our new source of EPR-entangled narrow-band photons is expected to play an essential role in spatially multiplexed quantum information processing, such as, storage of quantum correlated images, quantum interface involving hyperentangled photons, etc.

Goldstone mode and pair-breaking excitations in atomic Fermi superfluids

Science.gov (United States)

Hoinka, Sascha; Dyke, Paul; Lingham, Marcus G.; Kinnunen, Jami J.; Bruun, Georg M.; Vale, Chris J.

2017-10-01

Spontaneous symmetry breaking is a central paradigm of elementary particle physics, magnetism, superfluidity and superconductivity. According to Goldstone's theorem, phase transitions that break continuous symmetries lead to the existence of gapless excitations in the long-wavelength limit. These Goldstone modes can become the dominant low-energy excitation, showing that symmetry breaking has a profound impact on the physical properties of matter. Here, we present a comprehensive study of the elementary excitations in a homogeneous strongly interacting Fermi gas through the crossover from a Bardeen-Cooper-Schrieffer (BCS) superfluid to a Bose-Einstein condensate (BEC) of molecules using two-photon Bragg spectroscopy. The spectra exhibit a discrete Goldstone mode, associated with the broken-symmetry superfluid phase, as well as pair-breaking single-particle excitations. Our techniques yield a direct determination of the superfluid pairing gap and speed of sound in close agreement with strong-coupling theories.

Perbedaan Motivasi Belajar dan Percaya Diri antara Siswa yang Berasal dari Keluarga Utuh dengan Keluarga Broken Home

OpenAIRE

Rakhmawatiningtyas, Sustin

2013-01-01

. The main purposes of this research are to find the differences of learning motivation and self-confidence of students come from intact family or peace family and the broken family. The subjects in this study were 100 students come from SMA Negeri I Panji Situbondo. They were 50 students from intact families and 50 students from families broken home. Data analysis was used statistical t-test. Results showed learning motivation of students come from intact families is more high than student...

Study for evaluation of filter thickness in the determination of k Vp in function of the attenuation relative factors of the radiation

International Nuclear Information System (INIS)

Martin, J.G.; Souza, R.T.F.; Carbi, E.D.O.; Pina, D.R.

2009-01-01

This work consisted of evaluating 3 pairs of filters (cupper). The aim of it was to verify the best combination between attenuating material thicknesses for determination voltage value applied to X ray tube as function of attenuation relative factors. The employed methodology consisted of measuring the relative expositions, using thicknesses copper plates: (0,3, 0,5 and 0,8) mm. The thicknesses had been combined between itself with the purpose to form pairs of filters look that used ones ink Vp measurers. The great kVp band was used for 3 X ray equipment with generators of single-phase. Three-phase tension of 12 pulses and generator of tension in high frequency. The results had pointed the best combination, the thicknesses of filters (0,5/0,3) mm, because it does not have presented duplicity of values throughout all the band of evaluated tension. The results had still shown that the relative attenuation factors had not suffered significant variations between the different equipment with different voltage wave form. The variations found are related with differences in the effective energy of X ray beam. (author)

High-power picosecond pulse delivery through hollow core photonic band gap fibers

DEFF Research Database (Denmark)

Michieletto, Mattia; Johansen, Mette Marie; Lyngsø, Jens Kristian

2015-01-01

We demonstrated robust and bend insensitive fiber delivery of high power pulsed laser with diffraction limited beam quality for two different kind of hollow core photonic band gap fibers......We demonstrated robust and bend insensitive fiber delivery of high power pulsed laser with diffraction limited beam quality for two different kind of hollow core photonic band gap fibers...

Relations between broad-band linear polarization and Ca II H and K emission in late-type dwarf stars

Science.gov (United States)

Huovelin, Juhani; Saar, Steven H.; Tuominen, Ilkka

1988-01-01

Broadband UBV linear polarization data acquired for a sample of late-type dwarfs are compared with contemporaneous measurements of Ca II H and K line core emission. A weighted average of the largest values of the polarization degree is shown to be the best parameter for chromospheric activity diagnosis. The average maximum polarization in the UV is found to increase from late-F to late-G stars. It is noted that polarization in the U band is considerably more sensitive to activity variations than that in the B or V bands. The results indicate that stellar magnetic fields and the resulting saturation in the Zeeman-sensitive absorption lines are the most probably source of linear polarization in late-type main-sequence stars.

Subconjunctival Hemorrhage (Broken Blood Vessel in Eye)

Science.gov (United States)

Subconjunctival hemorrhage (broken blood vessel in eye) Overview A subconjunctival hemorrhage (sub-kun-JUNK-tih-vul HEM-uh-ruj) ... may not even realize you have a subconjunctival hemorrhage until you look in the mirror and notice ...

In-situ burning of crude oil and emulsions in broken ice

International Nuclear Information System (INIS)

Guenette, C.C.; Wighus, R.

1996-01-01

Large scale burns were conducted in a fjord in Norway, with fresh and emulsified crude oil to determine the feasibility of in-situ burning operations in an ice zone. The objective was to study the flame spreading characteristics of burning oil and emulsions in broken ice. The effect of wind on the flame spreading from one slick area to another was studied. The thermal environment produced by a crude oil fire on the sea surface and the response of a steel construction to the heat exposure from the fire was determined. The studies showed that high burning efficiencies (95 to 99%) could be obtained when burning fresh oil and emulsions contained in broken ice. Flame spreading was observed mostly in the downwind direction, and was dependent on the wind speed and direction. The temperatures and heat fluxes measured in the flames were higher than previously measured in pool fires. 9 refs., 7 figs

Design of a low emittance and high repetition rate S-band photoinjector

Science.gov (United States)

Han, Jang-Hui

2014-09-01

As an electron beam injector of X-ray free-electron lasers (FELs), photoinjectors have been developed for the past few decades. Such an injector starting with a photocathode RF gun provides high brightness beams and therefore it is being adopted as an injector of X-ray FELs. In this paper we show how to improve photoinjector performance in terms of emittance and repetition rates by means of injector components optimization, especially with the gun. Transverse emittance at the end of an injector is reduced by optimizing the gun design, gun solenoid position, and accelerating section position. The repetition rate of an injector mainly depends on the gun. It is discussed that a repetition rate of 1 kHz at a normal-conducting S-band photoinjector is feasible by adopting a coaxial RF coupler and improving cooling-water channels surrounding the gun.

Majorana surface modes of nodal topological pairings in spin-3/2 semimetals

Science.gov (United States)

Yang, Wang; Xiang, Tao; Wu, Congjun

2017-10-01

When solid state systems possess active orbital-band structures subject to spin-orbit coupling, their multicomponent electronic structures are often described in terms of effective large-spin fermion models. Their topological structures of superconductivity are beyond the framework of spin singlet and triplet Cooper pairings for spin-1/2 systems. Examples include the half-Heusler compound series of RPtBi, where R stands for a rare-earth element. Their spin-orbit coupled electronic structures are described by the Luttinger-Kohn model with effective spin-3/2 fermions and are characterized by band inversion. Recent experiments provide evidence to unconventional superconductivity in the YPtBi material with nodal spin-septet pairing. We systematically study topological pairing structures in spin-3/2 systems with the cubic group symmetries and calculate the surface Majorana spectra, which exhibit zero energy flat bands, or, cubic dispersion depending on the specific symmetry of the superconducting gap functions. The signatures of these surface states in the quasiparticle interference patterns of tunneling spectroscopy are studied, which can be tested in future experiments.

Analyzing shear band formation with high resolution X-ray diffraction

Energy Technology Data Exchange (ETDEWEB)

Pagan, Darren C.; Obstalecki, Mark; Park, Jun-Sang; Miller, Matthew P.

2018-04-01

Localization of crystallographic slip into shear bands during uniaxial compression of a copper single crystal is studied using very far-field high-energy diffraction microscopy (vff-HEDM). Diffracted intensity was collected in-situ as the crystal deformed using a unique mobile detector stage that provided access to multiple diffraction peaks with high-angular resolution. From the diffraction data, single crystal orientation pole figures (SCPFs) were generated and are used to track the evolution of the distribution of lattice orientation that develops as slip localizes. To aid the identification of 'signatures' of shear band formation and analyze the SCPF data, a model of slip-driven lattice reorientation within shear bands is introduced. Confidence is built in conclusions drawn from the SCPF data about the character of internal slip localization through comparisons with strain fields on the sample surface measured simultaneously using digital image correlation. From the diffraction data, we find that the active slip direction and slip plane are not directly aligned with the orientation of the shear bands that formed. In fact, by extracting the underlying slip system activity from the SCPF data, we show that intersecting shear bands measured on the surface of the sample arise from slip primarily on the same underlying single slip system. These new vff-HEDM results raise significant questions on the use of surface measurements for slip system activity estimation. (C) 2018 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

Development of a High-Stability Microstrip-based L-band Radiometer for Ocean Salinity Measurements

Science.gov (United States)

Pellerano, Fernando A.; Horgan, Kevin A.; Wilson, William J.; Tanner, Alan B.

2004-01-01

The development of a microstrip-based L-band Dicke radiometer with the long-term stability required for future ocean salinity measurements to an accuracy of 0.1 psu is presented. This measurement requires the L-band radiometers to have calibration stabilities of less than or equal to 0.05 K over 2 days. This research has focused on determining the optimum radiometer requirements and configuration to achieve this objective. System configuration and component performance have been evaluated with radiometer test beds at both JPL and GSFC. The GSFC testbed uses a cryogenic chamber that allows long-term characterization at radiometric temperatures in the range of 70 - 120 K. The research has addressed several areas including component characterization as a function of temperature and DC bias, system linearity, optimum noise diode injection calibration, and precision temperature control of components. A breadboard radiometer, utilizing microstrip-based technologies, has been built to demonstrate this long-term stability.

Multiple superdeformed bands in Sr, Y, and Zr nuclei

International Nuclear Information System (INIS)

Reviol, W.; Sarantites, D.G.; Lerma, F.; Devlin, M.; LaFosse, D.R.; Chiara, C.J.; Wyss, R.; Baktash, C.; Jin, H.-Q.; Tabor, S.L.; Soltysik, D.; Clark, R.M.; Lee, I.Y.; Macchiavelli, A.O.; MacLeod, R.W.

2003-01-01

Multiple superdeformed bands in the nuclei 80-83Sr, 82-84Y, and 83,84Zr have been studied in a backed-target experiment using the Gammasphere and Microball detector arrays. For 15 bands in these nuclei, average transition quadrupole moments (Qt) have been measured accurately. Among those are two pairs of 'isospectral' bands and the Qt values obtained in each case are nearly identical. The measured Qt values and dynamical moments of inertia place stringent conditions on configuration assignments for the bands obtained from mean field calculations

suitability of broken bottles as fine aggregate for production of concrete

African Journals Online (AJOL)

user

The maximum mean compressive strength of 19.0N/mm2 was obtained at 28days when sand and broken bottles were used in equal proportions. Density did not appear to have a discernible trend. For structural concrete, the proportion of broken bottles should be limited to 30% for early strength concrete and 40% when ...

Mechanisms of astrocytic K(+) clearance and swelling under high extracellular K(+) concentrations.

Science.gov (United States)

Murakami, Shingo; Kurachi, Yoshihisa

2016-03-01

In response to the elevation of extracellular K(+) concentration ([K(+)]out), astrocytes clear excessive K(+) to maintain conditions necessary for neural activity. K(+) clearance in astrocytes occurs via two processes: K(+) uptake and K(+) spatial buffering. High [K(+)]out also induces swelling in astrocytes, leading to edema and cell death in the brain. Despite the importance of astrocytic K(+) clearance and swelling, the underlying mechanisms remain unclear. Here, we report results from a simulation analysis of astrocytic K(+) clearance and swelling. Astrocyte models were constructed by incorporating various mechanisms such as intra/extracellular ion concentrations of Na(+), K(+), and Cl(-), cell volume, and models of Na,K-ATPase, Na-K-Cl cotransporter (NKCC), K-Cl cotransporter, inwardly-rectifying K(+) (KIR) channel, passive Cl(-) current, and aquaporin channel. The simulated response of astrocyte models under the uniform distribution of high [K(+)]out revealed significant contributions of NKCC and Na,K-ATPase to increases of intracellular K(+) and Cl(-) concentrations, and swelling. Moreover, we found that, under the non-uniform distribution of high [K(+)]out, KIR channels localized at synaptic clefts absorbed excess K(+) by depolarizing the equivalent potential of K(+) (E K) above membrane potential, while K(+) released through perivascular KIR channels was enhanced by hyperpolarizing E K and depolarizing membrane potential. Further analysis of simulated drug effects revealed that astrocyte swelling was modulated by blocking each of the ion channels and transporters. Our simulation analysis revealed controversial mechanisms of astrocytic K(+) clearance and swelling resulting from complex interactions among ion channels and transporters.

Strain hardening by dynamic slip band refinement in a high-Mn lightweight steel

International Nuclear Information System (INIS)

Welsch, E.; Ponge, D.; Hafez Haghighat, S.M.; Sandlöbes, S.; Choi, P.; Herbig, M.; Zaefferer, S.; Raabe, D.

2016-01-01

The strain hardening mechanism of a high-Mn lightweight steel (Fe-30.4Mn-8Al-1.2C (wt%)) is investigated by electron channeling contrast imaging (ECCI) and transmission electron microscopy (TEM). The alloy is characterized by a constant high strain hardening rate accompanied by high strength and high ductility (ultimate tensile strength: 900 MPa, elongation to fracture: 68%). Deformation microstructures at different strain levels are studied in order to reveal and quantify the governing structural parameters at micro- and nanometer scales. As the material deforms mainly by planar dislocation slip causing the formation of slip bands, we quantitatively study the evolution of the slip band spacing during straining. The flow stress is calculated from the slip band spacing on the basis of the passing stress. The good agreement between the calculated values and the tensile test data shows dynamic slip band refinement as the main strain hardening mechanism, enabling the excellent mechanical properties. This novel strain hardening mechanism is based on the passing stress acting between co-planar slip bands in contrast to earlier attempts to explain the strain hardening in high-Mn lightweight steels that are based on grain subdivision by microbands. We discuss in detail the formation of the finely distributed slip bands and the gradual reduction of the spacing between them, leading to constantly high strain hardening. TEM investigations of the precipitation state in the as-quenched state show finely dispersed atomically ordered clusters (size < 2 nm). The influence of these zones on planar slip is discussed.

Broken supersymmetries and shifted superpropagators

International Nuclear Information System (INIS)

Helayel-Neto, J.A.; Rabelo de Carvalho, F.A.B.; Smith, A.W.

1985-06-01

Superfield Feynman rules are derived for a general case where global supersymmetry is spontaneously broken by F-terms. The complete superspace dependence of the superpropagators is factored out and they are employed to discuss the corrections to the effective action and the non-renormalization theorems. Their coupling to external gauge superfields is also contemplated and finite matter contributions to the gaugino mass and the Fayet-Iliopoulos term are considered. (author)

Separation of amaranthine-type betacyanins by ion-pair high-speed countercurrent chromatography.

Science.gov (United States)

Jerz, Gerold; Gebers, Nadine; Szot, Dominika; Szaleniec, Maciej; Winterhalter, Peter; Wybraniec, Slawomir

2014-05-30

Betacyanins, red-violet plant pigments, were fractionated by ion-pair high-speed countercurrent chromatography (IP-HSCCC) from leaves extract of Iresine lindenii Van Houtte, an ornamental plant of the family Amaranthaceae. An HSCCC solvent system consisting of TBME-1-BuOH-ACN-H2O (1:3:1:5, v/v/v/v) was applied using ion-pair forming heptafluorobutyric acid (HFBA). Significantly different elution profiles of betacyanin diastereomeric pairs (derivatives based on betanidin and isobetanidin) observed in the HSCCC in comparison to HPLC systems indicate a complementarity of both techniques' fractionation capabilities. The numerous diastereomeric pairs can be selectively separated from each other using the HSCCC system simplifying the pigment purification process. Apart from the three well known highly abundant pigments (amaranthine, betanin and iresinin I) together with their isoforms, three new acylated (feruloylated and sinapoylated) betacyanins as well as known pigment hylocerenin (previously isolated from cacti fruits) were characterized in the plant for the first time and they are new for the whole Amaranthaceae family. Copyright © 2014 Elsevier B.V. All rights reserved.

Pair correlations in nuclei

International Nuclear Information System (INIS)

Shimizu, Yoshifumi

2009-01-01

Except for the closed shell nuclei, almost all nuclei are in the superconducting state at their ground states. This well-known pair correlation in nuclei causes various interesting phenomena. It is especially to be noted that the pair correlation becomes weak in the excited states of nuclei with high angular momentum, which leads to the pair phase transition to the normal state in the high spin limit. On the other hand, the pair correlation becomes stronger in the nuclei with lower nucleon density than in those with normal density. In the region of neutron halo or skin state of unstable nuclei, this phenomenon is expected to be further enhanced to be observed compared to the ground state of stable nuclei. An overview of those interesting aspects caused via the pair correlation is presented here in the sections titled 'pair correlations in ground states', pair correlations in high spin states' and 'pair correlations in unstable nuclei' focusing on the high spin state. (S. Funahashi)

Differential bremsstrahlung and pair production cross sections at high energies

International Nuclear Information System (INIS)

Olsen, Haakon A.

2003-01-01

Detailed differential cross sections for high energy bremsstrahlung and pair production are derived with specific attention to the differences between the two processes, which are considerable. For the integrated cross sections, which are the only cross sections specifically known until now, the final state integration theorem guarantees that the exact cross section formulas can be exchanged between bremsstrahlung and pair production by the same substitution rules as for the Born-approximation Bethe-Heitler cross sections, for any amount of atomic screening. In fact the theorem states that the Coulomb corrections to the integrated bremsstrahlung and pair production cross sections are identical for any amount of screening. The analysis of the basic differential cross sections leads to fundamental physical differences between bremsstrahlung and pair production. Coulomb corrections occur for pair production in the strong electric field of the atom for 'large' momentum transfer of the order of mc. For bremsstrahlung, on the other hand, the Coulomb corrections take place at a 'large' distance from the atom of the order of ((ℎ/2π)/mc)ε, with a 'small' momentum transfer mc/ε, where ε is the initial electron energy in units of mc 2 . And the Coulomb corrections can be large, of the order of larger than (Z/137) 2 , which is considerably larger than the integrated cross section corrections

Valence and conduction band offsets at low-k a-SiO{sub x}C{sub y}:H/a-SiC{sub x}N{sub y}:H interfaces

Energy Technology Data Exchange (ETDEWEB)

King, Sean W., E-mail: sean.king@intel.com; Brockman, Justin; French, Marc; Jaehnig, Milt; Kuhn, Markus [Logic Technology Development, Intel Corporation, Hillsboro, Oregon 97124 (United States); French, Benjamin [Ocotillo Materials Laboratory, Intel Corporation, Chandler, Arizona 85248 (United States)

2014-09-21

In order to understand the fundamental electrical leakage and reliability failure mechanisms in nano-electronic low-k dielectric/metal interconnect structures, we have utilized x-ray photoelectron spectroscopy and reflection electron energy loss spectroscopy to determine the valence and conduction band offsets present at interfaces between non-porous and porous low-k a-SiO{sub x}C{sub y}:H interlayer dielectrics and a-SiC{sub x}N{sub y}:H metal capping layers. The valence band offset for such interfaces was determined to be 2.7±0.2 eV and weakly dependent on the a-SiOC:H porosity. The corresponding conduction band offset was determined to be 2.1±0.2 eV. The large band offsets indicate that intra metal layer leakage is likely dominated by defects and trap states in the a-SiOC:H and a-SiCN:H dielectrics.

INFLUENCE OF BROKEN ROTOR BARS LOCATION IN THE SQUIRREL CAGE INDUCTION MOTOR USING FINITE ELEMENT METHOD

Directory of Open Access Journals (Sweden)

N. Halem

2013-06-01

Full Text Available It is well known that the number of broken bars and varying load affect on the amplitudes of specific harmonic components in the process analysis of induction motors under broken rotor bars. The location of broken bars is an important factor which affects the diagnosis of the broken bars defect. In this paper the simulation is determinate for different cases for distribution of broken bars under induction motor pole in order to show the impact of broken bars location upon the amplitude of harmonic fault. The simulation results are obtained by using time stepping finite elements (TSFE method. The geometrical characteristics of motor, the effects of slotting and the magnetic saturation of lamination core are included in induction motor model.

INFLUENCE OF BROKEN ROTOR BARS LOCATION IN THE SQUIRREL CAGE INDUCTION MOTOR USING FINITE ELEMENT METHOD

Directory of Open Access Journals (Sweden)

N. Halem

2015-07-01

Full Text Available It is well known that the number of broken bars and varying load affect on the amplitudes of specific harmonic components  in the process analysis of induction motors under broken rotor bars. The location of broken bars is an important factor which affects the diagnosis of the broken bars defect. In this paper the simulation is determinate for different cases for distribution of broken bars under induction motor pole in order to show the impact of broken bars location upon the amplitude of harmonic fault. The simulation results are obtained by using time stepping finite elements (TSFE method. The geometrical characteristics of motor, the effects of slotting and the magnetic saturation of lamination core are included in induction motor model.

High-spin states in the A=39 mirror nuclei 39Ca and 39K

International Nuclear Information System (INIS)

Andersson, T.; Rudolph, D.; Fahlander, C.; Eberth, J.; Thomas, H.G.; Haslip, D.; Svensson, C.E.; Waddington, J.C.; LaFosse, D.R.; Sarantites, D.G.; Weintraub, W.; Wilson, J.N.; Brown, B.A.

1999-01-01

High-spin states of the mass A=39 mirror pair 39 K and 39 Ca were investigated via the fusion-evaporation reaction 28 Si+ 16 O at 125 MeV beam energy. The gammasphere array in conjunction with the 4π charged-particle detector array microball and neutron detectors was used to detect γ rays in coincidence with evaporated light particles. The results of the first high-spin study of the T z =-1/2 nucleus 39 Ca are discussed in terms of mirror symmetry and compared to spherical shell-model calculations in the 1d 3/2 -1f 7/2 configuration space. (orig.)

Band engineering and rational design of high-performance thermoelectric materials by first-principles

Directory of Open Access Journals (Sweden)

Lili Xi

2016-06-01

Full Text Available Understanding and manipulation of the band structure are important in designing high-performance thermoelectric (TE materials. Our recent work has involved the utilization of band structure in various topics of TE research, i.e., the band convergence, the conductive network, dimensionality reduction by quantum effects, and high throughput material screening. In non-cubic chalcopyrite compounds, we revealed the relations between structural factors and band degeneracy, and a simple unity-η rule was proposed for selecting high performance diamond-like TE materials. Based on the deep understanding of the electrical and thermal transport, we identified the conductive network in filled skutterudites with the “phonon glass-electron crystal” (PGEC paradigm, and extended this concept to caged-free Cu-based diamond-like compounds. By combining the band structure calculations and the Boltzmann transport theory, we conducted a high-throughput material screening in half-Heusler (HH systems, and several promising compositions with high power factors were proposed out of a large composition collection. At last, we introduced the Rashba spin-splitting effect into thermoelectrics, and its influence on the electrical transport properties was discussed. This review demonstrated the importance of the microscopic perspectives for the optimization and design of novel TE materials.

Excited cooper pairs

Energy Technology Data Exchange (ETDEWEB)

Lopez-Arrietea, M. G.; Solis, M. A.; De Llano, M. [Universidad Nacional Autonoma de Mexico, Mexico, D.F (Mexico)

2001-02-01

Excited cooper pairs formed in a many-fermion system are those with nonzero total center-of mass momentum (CMM). They are normally neglected in the standard Bardeen-Cooper-Schrieffer (BCS) theory of superconductivity for being too few compared with zero CMM pairs. However, a Bose-Einstein condensation picture requires both zero and nonzero CMM pairs. Assuming a BCS model interaction between fermions we determine the populations for all CMM values of Cooper pairs by actually calculating the number of nonzero-CMM pairs relative to that of zero-CMM ones in both 2D and 3D. Although this ratio decreases rapidly with CMM, the number of Cooper pairs for any specific CMM less than the maximum (or breakup of the pair) momentum turns out to be typically larger than about 95% of those with zero-CMM at zero temperature T. Even at T {approx}100 K this fraction en 2D is still as large as about 70% for typical quasi-2D cuprate superconductor parameters. [Spanish] Los pares de cooper excitados formados en un sistema de muchos electrones, son aquellos con momentos de centro de masa (CMM) diferente de cero. Normalmente estos no son tomados en cuenta en la teoria estandar de la superconductividad de Bardeen-Cooper-Schrieffer (BCS) al suponer que su numero es muy pequeno comparados con los pares de centro de masa igual a cero. Sin embargo, un esquema de condensacion Bose-Einstein requiere de ambos pares, con CMM cero y diferente de cero. Asumiendo una interaccion modelo BCS entre los fermiones, determinamos la poblacion de pares cooper con cada uno de todos los posibles valores del CMM calculando el numero de pares con momentos de centro de masa diferente de cero relativo a los pares de CMM igual a cero, en 2D y 3D. Aunque esta razon decrece rapidamente con el CMM, el numero de pares de cooper para cualquier CMM especifico menor que el momento maximo (o rompimiento de par) es tipicamente mas grande que el 95% de aquellos con CMM cero. Aun a T {approx}100 K esta fraccion en 2D es

Low-Profile Multiband and Flush-Mountable Wideband Antennas for HF/VHF and K/Ka Band Applications

Science.gov (United States)

Garrido Lopez, David

This thesis introduces several novel antenna systems with extended performance capabilities achieved by either enabling multiple operation bands or by widening the bandwidth. Proposed theoretical concepts are successfully tested through simulations and experiments with excellent agreement are demonstrated. The designs developed in this thesis research are low-profile or flush mountable, enabling simple platform integration. In the HF/VHF bands, the development of a novel low-profile multiband antenna for vehicular applications is presented. Specifically, an inverted-F antenna is used as a driven element, to operate at the lowest frequency of 27 MHz, whereas two parasitic elements are built as inverted-L monopoles to enable resonances at 49 and 53 MHz. To eliminate the need for an external matching network, an offset feeding technique is used. When the antenna is mounted on a vehicle and bent to follow its profile, a very low-profile is achieved (lambda/44) while good impedance and far-field performance are maintained across all three bands. The developed antenna system is not only electrically smallest among others found in the literature, but it is easily modified for other band selections and tuning of each band can be readily achieved. Vehicular antennas are often used for high power applications, which may cause exposure of nearby individuals to possibly dangerous electromagnetic fields. To assess this hazard, the RF exposure of a vehicle's crew is discussed and an original and fast modeling approach for prediction thereof is demonstrated. The modeling approach is based on eigenmode analysis for acquiring a range of frequencies where the shielding effectiveness of a vehicle cabin is expected to be lower than average. This approach is typically much faster and requires less computational resources as compared to classical full-wave analyses. This analysis also shows that the position of an antenna system is critical and must be considered when high-power RF

Improvement of Ka-band satellite link availability for real-time IP-based video contribution

Directory of Open Access Journals (Sweden)

G. Berretta

2017-09-01

Full Text Available New High Throughput Satellite (HTS systems allow high throughput IP uplinks/contribution at Ka-band frequencies for relatively lower costs when compared to broadcasting satellite uplinks at Ku band. This technology offers an advantage for live video contribution from remote areas, where the terrestrial infrastructure may not be adequate. On the other hand, the Ka-band is more subject to impairments due to rain or bad weather. This paper addresses the target system specification and provides an optimized approach for the transmission of IP-based video flows through HTS commercial services operating at Ka-band frequencies. In particular, the focus of this study is on the service requirements and the propagation analysis that provide a reference architecture to improve the overall link availability. The approach proposed herein leads to the introduction of a new concept of live service contribution using pairs of small satellite antennas and cheap satellite terminals.

NLTE ANALYSIS OF HIGH-RESOLUTION H -BAND SPECTRA. II. NEUTRAL MAGNESIUM

Energy Technology Data Exchange (ETDEWEB)

Zhang, Junbo; Shi, Jianrong; Liu, Chao [Key Laboratory of Optical Astronomy, National Astronomical Observatories, Chinese Academy of Sciences, A20 Datun Road, Chaoyang District, Beijing 100012 (China); Pan, Kaike [Apache Point Observatory and New Mexico State University, P.O. Box 59, Sunspot, NM 88349-0059 (United States); Prieto, Carlos Allende, E-mail: sjr@bao.ac.cn [Instituto de Astrofísica de Canarias, E-38205 La Laguna, Tenerife (Spain)

2017-01-20

Aiming at testing the validity of our magnesium atomic model and investigating the effects of non-local thermodynamical equilibrium (NLTE) on the formation of the H -band neutral magnesium lines, we derive the differential Mg abundances from selected transitions for 13 stars either adopting or relaxing the assumption of local thermodynamical equilibrium (LTE). Our analysis is based on high-resolution and high signal-to-noise ratio H -band spectra from the Apache Point Observatory Galactic Evolution Experiment (APOGEE) and optical spectra from several instruments. The absolute differences between the Mg abundances derived from the two wavelength bands are always less than 0.1 dex in the NLTE analysis, while they are slightly larger for the LTE case. This suggests that our Mg atomic model is appropriate for investigating the NLTE formation of the H -band Mg lines. The NLTE corrections for the Mg i H -band lines are sensitive to the surface gravity, becoming larger for smaller log g values, and strong lines are more susceptible to departures from LTE. For cool giants, NLTE corrections tend to be negative, and for the strong line at 15765 Å they reach −0.14 dex in our sample, and up to −0.22 dex for other APOGEE stars. Our results suggest that it is important to include NLTE corrections in determining Mg abundances from the H -band Mg i transitions, especially when strong lines are used.

Band-to-Band Tunneling-Dominated Thermo-Enhanced Field Electron Emission from p-Si/ZnO Nanoemitters.