Superdeformed bands in 64147Gd83, a possible test of the existence of octupole correlations in superdeformed bands

International Nuclear Information System (INIS)

Zuber, K.; Balouka, D.; Beck, F.A.; Byrski, T.; Curien, D.; Duchene, G.; Gehringer, C.; Haas, B.; Merdinger, J.C.; Romain, P.; Santos, D.; Styczen, J.; Vivien, J.P.; Dudek, J.; Szymanski, Z.; Werner, T.

1990-01-01

Two discrete superdeformed bands (SD) have been identified in the nucleus 147 Gd. The transitions energies of the SD yrast band lie halfway between the γ-ray energies of the yrast SD band in 146 Gd while the transition energies of the excited band lie half way between the transition energies of the yrast SD band in 148 Gd. These two bands are shown to exhibit the presence of the pseudo SU(3) symmetry and also indicate the possible existence of octupole correlations at large elongations and high spins. (orig.)

Yrast four-quasi-particle states in 182W

International Nuclear Information System (INIS)

Regan, P.H.; Walker, P.M.; Dracoulis, G.D.; Anderssen, S.S.; Byrne, A.P.; Davidson, P.M.; Kibedi, T.; Lane, G.J.; Stuchbery, A.E.; Yeung, K.C.

1994-01-01

High-spin states of the stable isotope 182 W have been studied using the reactions 176 Yb( 13 C,α3n) 182 W and 176 Yb( 9 Be,3n) 182 W at beam energies of 65 and 40 MeV, respectively. Three, possibly four, new intrinsic states at high spins have been observed corresponding to different high-K four-quasi-particle structures. The K π =15 + and 17 - levels have lifetimes of 78(15) and 25(10) ns, respectively. Rotational bands are observed built on the K π =16 + and 17 - yrast states. The coupling of Nilsson orbitals which give rise to high-K states at the yrast line and the K-forbiddenness of the K π =15 + isomeric decay are discussed. (orig.)

Microscopic insight in the study of yrast bands in selenium isotopes

Indian Academy of Sciences (India)

the rotational-like energy spacings of the yrast states with I≥6. ... even–even selenium isotopes, the study of structure of high spin states through mea- ... calculations with this model can achieve a comparable quality to the large-scale ... model in that the PSM uses the angular momentum projected states as the basis.

Superdeformed bands in sub 64 sup 147 Gd sub 83 , a possible test of the existence of octupole correlations in superdeformed bands

Energy Technology Data Exchange (ETDEWEB)

Zuber, K.; Balouka, D.; Beck, F.A.; Byrski, T.; Curien, D.; Duchene, G.; Gehringer, C.; Haas, B.; Merdinger, J.C.; Romain, P.; Santos, D.; Styczen, J.; Vivien, J.P.; Dudek, J.; Szymanski, Z.; Werner, T. (Strasbourg-1 Univ., 67 (France). Centre de Recherches Nucleaires)

1990-12-24

Two discrete superdeformed bands (SD) have been identified in the nucleus {sup 147}Gd. The transitions energies of the SD yrast band lie halfway between the {gamma}-ray energies of the yrast SD band in {sup 146}Gd while the transition energies of the excited band lie half way between the transition energies of the yrast SD band in {sup 148}Gd. These two bands are shown to exhibit the presence of the pseudo SU(3) symmetry and also indicate the possible existence of octupole correlations at large elongations and high spins. (orig.).

Poisson and Porter-Thomas fluctuations in off-yrast rotational transitions

International Nuclear Information System (INIS)

Matsuo, M.; Doessing, T.; Herskind, B.; Frauendorf, S.

1993-01-01

Fluctuations associated with stretched E2 transitions from high-spin levels in nuclei around 168 Yb are investigated by a cranked shell model extended to include residual two-body interactions. In the cranked mean-field model without residual interactions, it is found that gamma-ray energies behave like random variables and the energy spectra show Poisson fluctuation. With two-body residual interactions included, the discrete transition pattern with unmixed rotational bands is still valid up to around 600 keV above yrast, in good agreement with experiments. At higher excitation energy, a gradual onset of rotational damping emerges. At 1.8 MeV above yrast, complete damping is observed with GOE-type fluctuations for both energy levels and transition strengths (Porter-Thomas fluctuations). (orig.)

Change of deformation at the backbending in the yrast superdeformed band of {sup 144}Gd

Energy Technology Data Exchange (ETDEWEB)

Ur, C.A.; Bolzonella, G.P.; Bazzacco, D. [dell`Universita, Padova (Italy)]|[INFN, Padova (Italy)] [and others

1996-12-31

A mean lifetime measurement using the Doppler shift attenuation method has been performed at GASP in order to extract the quadrupole moment of the yrast SD band of {sup 144}Gd. The extracted intrinsic quadrupole moments, being Q{sub 0}=13.7 eb above the backbending and Q{sub 0}=11.8 eb below the backbending, are consistent with a change of deformation from {beta}{sub 2}=0.51 (at {beta}{sub 4} {approx} 0.050) to {beta}{sub 2}=0.45 (at {beta}{sub 4} {approx}0.035). The experimental results are in nice agreement with the theoretical predictions, which revealed that the second well in {sup 144}Gd arises essentially from the very favored shell structure at N=80 and Z=64. The occupation at higher frequency of the aligned N=6 proton orbitals drives the nucleus to a slightly more deformed shape.

Search for the discrete non-yrast states in 152Dy around 86 ns isomer, the region into which the γ-rays drain the super-deformed band

International Nuclear Information System (INIS)

Mansour, N.

1991-01-01

Further analysis of the γ-ray study of 152 Dy emitted in the decay of the super-deformed band has been performed by using the 122 Sn ( 35 Cl, P4n) reaction at low bombarding energies. Several γ-rays de-exciting non-yrast states have been identified, among these are transitions previously observed in coincidence with this super-deformed band. The lowest two members of the super-deformed cascade have also been detected, but the data is not quite good enough to make a firm connection to them. (author)

Decay out of the yrast and excited highly-deformed bands in the even-even nucleus {sup 134}Nd

Energy Technology Data Exchange (ETDEWEB)

Petrache, C.M.; Bazzacco, D.; Lunardi, S. [Sezione di Padova (Italy)] [and others

1996-12-31

The resolving power achieved by the new generation of {gamma}-ray detector arrays allows now to observe transitions with intensities of the order of {approximately}10{sup {minus}3} of the population of the final residual nucleus, making therefore feasible the study of the very weakly populated excited bands built on the superdeformed (SD) minimum or of the decay out of the SD bands. As a matter of fact, numerous excited SD bands have been observed in the different regions of superdeformation, which led to a deeper understanding of the single-particle excitation in the second minimum. The first experimental breakthrough in the study of the decay out process has been achieved in the odd-even {sup 133,135}Nd nuclei of the A=130 mass region. There, the observation of the discrete linking transitions has been favored by the relatively higher intensity of the highly-deformed (HD) bands ({approximately}10%), as well as by the small excitation energy with respect to the yrast line in the decay-out region ({approximately}1 MeV). No discrete linking transitions have been so far observed in the A=80, 150 mass regions. The present results suggest that the decay out of the HD bands in {sup 134}Nd is triggered by the crossing with the N=4 [402]5/2{sup +} Nilsson orbital, that has a smaller deformation than the corresponding N=6 intruder configuration. The crossing favours the mixing with the ND rotational bands strongly enhancing the decay-out process and weakening the in-band transition strength. The HD band becomes fragmented and looses part of its character. The intensity of the decay-out transitions increases when the spin of the HD state decreases, indicating enhanced ND amplitude in the wavefunction when going down the band. Lifetime measurements of the HD bands are crucial to further elucidate the decay-out process.

Decay of superdeformed bands

International Nuclear Information System (INIS)

Carpenter, M.P.; Khoo, T.L.; Lauritsen, T.

1995-01-01

One of the major challenges in the study of superdeformation is to directly connect the large number of superdeformed bands now known to the yrast states. In this way, excitation energies, spins and parities can be assigned to the levels in the second well which is essential to establish the collective and single-particle components of these bands. This paper will review some of the progress which has been made to understand the decay of superdeformed bands using the new arrays including the measurement of the total decay spectrum and the establishment of direct one-step decays from the superdeformed band to the yrast line in 194 Hg. 42 refs., 5 figs

Energy correlations for mixed rotational bands

International Nuclear Information System (INIS)

Doessing, T.

1985-01-01

A schematic model for the mixing of rotational bands above the yrast line in well deformed nuclei is considered. Many-particle configurations of a rotating mean field form basis bands, and these are subsequently mixed due to a two body residual interaction. The energy interval over which a basis band is spread out increases with increasing excitation energy above the yrast line. Conversely, the B(E2) matrix element for rotational decay out of one of the mixed band states is spread over an interval which is predicted to become more narrow with increasing excitation energy. Finally, the implication of band mixing for γ-ray energy correlations is briefly discussed. (orig.)

Study of yrast structures in {sup 55,57}Cr

Energy Technology Data Exchange (ETDEWEB)

Gupta, Anuradha, E-mail: annu1gupta1@gmail; Kumar, Amit, E-mail: akbcw2@gmail.com [Research Scholar, University of Jammu, Jammu-180006 (India); Singh, Suram, E-mail: suramsingh@gmail.com [Assistant Professor, Department of Physics, G.D.C. Kathua, 184101 (India); Bharti, Arun, E-mail: arunbharti-2003@yahoo.co.in [Professor, University of Jammu, Jammu-180006 (India)

2016-05-06

The characteristic nuclear structure properties of yrast bands of {sup 55,57}Cr have been investigated by using two body effective interactions incorporated in phenomenological axial framework. In order to check the validity of the chosen framework as well as chosen valence space, the calculated results are compared with the available experimental data and a good agreement has been found from the comparison. The back-bending in moment of inertia has also been studied and attributed to the alignment of odd g{sub 9/2} neutron along the rotation axis.

Search for superdeformed bands in {sup 154}Dy

Energy Technology Data Exchange (ETDEWEB)

Nisius, D.; Janssens, R.V.F.; Khoo, T.L. [and others

1995-08-01

The island of superdeformation in the vicinity of the doubly magic {sup 152}Dy yrast superdeformed (SD) band is thought to be well understood in the framework of cranked mean field calculations. In particular, the calculations suggested that in {sup 154}Dy there should be no yrast or near yrast SD minimum in the 40-60 h spin range, where SD bands in this mass region are thought to be {sup 153}Dy nucleus, it is populated. However, with the presence of five SD bands in the neighboring necessary to ascertain if the addition of one single neutron diminishes the importance of shell effects to the extent that superdeformation can no longer be sustained. In an experiment utilizing the increased resolving power of the early implementation phase of Gammasphere, the reaction {sup 122}Sn({sup 36}S,4n) at 165 MeV was employed to populate high spin states in {sup 154}Dy. In a four-day run with 36 detectors, over one billion triple and higher fold coincidence events were recorded. One new SD band was identified and was assigned to {sup 154}Dy. From comparisons with the Im{sup (2)} moments of inertia of the SD bands in {sup 152}Dy and {sup 153}Dy, a configuration based on (514)9/2{sup 2} neutrons coupled to the {sup 152}Dy SD core was proposed. One unexpected and as yet unexplained feature of this new SD band is that the transition energies are almost identical to those of an excited SD band in {sup 153}Dy. It is also worth noting that the feeding of the yrast states is similar to that achieved by the deexcitation from the ensemble of all entry states in the reaction. This observation emphasizes the statistical nature of the decay-out process. A paper reporting these results was accepted for publication.

Toward yrast spectroscopy in soft vibrational nuclei

International Nuclear Information System (INIS)

Marumori, Toshio; Kuriyama, Atsushi; Sakata, Fumihiko.

1979-10-01

In a formally parallel way with that exciting progress has been recently achieved in understanding the yrast spectra of the rotational nuclei in terms of the quasi-particle motion in the rotating frame, an attempt to understand the yrast spectra of the vibrational nuclei in terms of the quasi-particle motion is proposed. The essential idea is to introduce the quasi-particle motion in a generalized vibrating frame, which can be regarded as a rotating frame in the gauge space of ''physical'' phonons where the number of the physical phonons plays the role of the angular momentum. On the basis of a simple fundamental principle called as the ''invariance principle of the Schroedinger equation'', which leads us to the ''maximal decoupling'' between the physical phonon and the intrinsic modes, it is shown that the vibrational frame as well as the physical-phonon-number operator represented by the quasi-particles can be self-consistently determined. A new scope toward the yrast spectroscopy of the vibrational nuclei in terms of the quasi-particle motion is discussed. (author)

Projected Shell Model Description of Positive Parity Band of 130Pr Nucleus

Science.gov (United States)

Singh, Suram; Kumar, Amit; Singh, Dhanvir; Sharma, Chetan; Bharti, Arun; Bhat, G. H.; Sheikh, J. A.

2018-02-01

Theoretical investigation of positive parity yrast band of odd-odd 130Pr nucleus is performed by applying the projected shell model. The present study is undertaken to investigate and verify the very recently observed side band in 130Pr theoretically in terms of quasi-particle (qp) configuration. From the analysis of band diagram, the yrast as well as side band are found to arise from two-qp configuration πh 11/2 ⊗ νh 11/2. The present calculations are viewed to have qualitatively reproduced the known experimental data for yrast states, transition energies, and B( M1) / B( E2) ratios of this nucleus. The recently observed positive parity side band is also reproduced by the present calculations. The energy states of the side band are predicted up to spin 25+, which is far above the known experimental spin of 18+ and this could serve as a motivational factor for future experiments. In addition, the reduced transition probability B( E2) for interband transitions has also been calculated for the first time in projected shell model, which would serve as an encouragement for other research groups in the future.

High spin states and Yrast isomers in 211Rn

International Nuclear Information System (INIS)

Poletti, A.R.; Dracoulis, G.D.; Fahlander, C.; Morrison, I.

1981-01-01

Excited states in 211 Rn with spins up to 53/2 have been identified using (HI,xn) reactions and γ-ray techniques. A shell model calculation can reproduce the ordering of the yrast sequence up to spin 41/2 - . Several yrast isomers have been identified. Enhanced E3 transitions are observed and their systematic occurrence in this region discussed. The influence of the neutron hole, and possible core excitations on the effective moment of inertia are also pointed out

High spin states and yrast isomers in 211Rn

International Nuclear Information System (INIS)

Poletti, A.R.; Dracoulis, G.D.; Fahlander, C.; Morrison, I.

1980-12-01

Excited states in 211 Rn with spins up to 53/2 have been identified using (HI,xn) reactions and γ-ray techniques. A shell model calculation can reproduce the ordering of the yrast sequence up to spin 41/2. Several yrast isomers have been identified. Enhanced E3 transitions are observed and their systematic occurrence in this region discussed. The influence of the neutron hole, and possible core excitations on the effective moment of inertia are also pointed out

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

High-spin isomer in 211Rn, and the shape of the yrast line

International Nuclear Information System (INIS)

Dracoulis, G.D.; Fahlander, C.; Poletti, A.R.

1981-08-01

High spin yrast states in 211 Rn have been identified. A 61/2 - , 380 ns isomer found at 8856 keV is characterised as a core-excited configuration. The average shape of the yrast line shows a smooth behaviour with spin, in contrast to its neighbour 212 Rn. This difference is attributed to the presence of the neutron hole

Microscopical structure of the states of deformed nuclei in the neighborhood of the yrast line

International Nuclear Information System (INIS)

Janssen, D.; Mikhailov, I.N.

1979-01-01

A simple model is derived which allows one to study the structure of the nuclear states in the neighborhood of the 'yrast' band. In the present scheme the precession motion plays a role of one of the normal modes of oscillations. (The structure of the dispersion equation for this mode corresponds to the well known classical formula.) Vibrational states associated with quadrupole oscillations of the nuclear shape are determined from a general equation. At slow rotation this equation breaks up into the known equations for β-, Δ- and γ-vibrations and non-collectivized Ksup(π)=1 + excitations. (Auth.)

Microscopic description of the three major bands in transitional nuclei

International Nuclear Information System (INIS)

Pineda S, R.L.

1986-01-01

The author has extended the Coherent Phonon Model to the description of the three major bands in medium heavy transitional nuclei. The model assumes an axially symmetric deformed ground intrinsic state for the description of the low lying yrast levels of the ground band, while the excited bands are generated by intrinsic excitations of the ground band. Good angular momentum states are generated by the Peierls-Yoccoz angular momentum projection method

Study of band structure in 78,80Sr using Triaxial Projected Shell Model

International Nuclear Information System (INIS)

Behera, N.; Naik, Z.; Bhat, G.H.; Sheikh, J.A.; Palit, R.; Sun, Y.

2017-01-01

The purpose of present work is to carry out a systematic study of the yrast-band and gamma-band structure for the even-even 78-80 Sr nuclei using Triaxial Projected Shell Model (TPSM) approach. These nuclei were chosen because 78 Sr has well developed side band(unassigned configuration) and 80 Sr has well developed band observed experimentally

Microscopic study of low-lying yrast spectra and deformation systematics of even-even barium isotopes

International Nuclear Information System (INIS)

Sarswat, S.P.; Bharti, Arun; Khosa, S.K.

1996-01-01

The yrast spectra has been obtained in the variation-after-projection framework using pairing-plus-quadrupole- quadrupole model for the two body interaction. Besides the low-lying yrast spectra, the calculated values of intrinsic quadrupole moments of some of the barium isotopes i.e. 124-134 Ba are presented

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}

Spectroscopical study of the yrast and yrare structure in far-from-stability nuclei; Etude spectroscopique de la structure yrast et yrare de noyaux loin de la stabilite

Energy Technology Data Exchange (ETDEWEB)

Hoellinger Fabien [Institut de Recherches Subatomiques, 23, Rue du Loess, BP 28, 67037 Strasbourg Cedex 2 (France)]|[Universite Louis Pasteur, 67 - Strasbourg (France)

1999-01-13

The nuclear structure study of neutron-rich nuclei was realized with the EUROGAM II array in two different experiments. The first study consisted in the analysis of the product of spontaneous fission of {sup 248}Cm. Three neutron-rich cerium isotopes {sup 147,149,151}Ce were analyzed. A level scheme for {sup 151}Ce is presented for the first time. The yrast structure of the three nuclei does not show alternative parity bands as expected in this region of octupole deformations. We studied the rotational structure of the bands and this leads to suggest Nilsson configurations to some of them. The aim of this second experiment was the study of the nuclei {sup 99}Mo, {sup 101}Tc, {sup 103}Ru. The three nuclei are situated on the neutron-rich side of the nuclear chart and are produced as fission fragments of a heavy-ion induced reaction. Some bands are extended to higher spins and some new bands are observed. The structure of the rotational bands is interpreted by means of the Hartree-Fock-Bogolyubov model. A last experiment intended to study the structure of the proton-rich nucleus {sup 223}Pa has been achieved with the JURO+RITU array located at Jyvaeskylae (Finland). In this proton-rich actinide region, the nuclei develop octupole features around Z{approx_equal}88, N{approx_equal}132. The analysis of this experiment leads to the first assignment of gamma transitions to the {sup 223}Pa. (author) 91 refs., 78 figs., 16 tabs.

High spin rotational bands in Zn

Indian Academy of Sciences (India)

We present here some preliminary results from our studies in the. ~ ¼ region in which we have observed an yrast band structure in Zn extending to spin (41/2 ). ... gaps implies that nuclei may exhibit different shapes at different excitation energies. .... uration, identifying previously unobserved states up to an excitation energy ...

Population of yrast states in 191Os using deep-inelastic reactions

Science.gov (United States)

Jones, G. A.; Podolyák, Zs; Walker, P. M.; Regan, P. H.; de Angelis, G.; Axiotis, M.; Bazzacco, D.; Bizzeti, P. G.; Brandolini, F.; Broda, R.; Bucurescu, D.; Farnea, E.; Gelletly, W.; Gadea, A.; Ionescu-Bujor, M.; Iordachescu, A.; Kröll, Th; Langdown, S. D.; Lunardi, S.; Marginean, N.; Martinez, T.; Medina, N. H.; Quintana, B.; Rubio, B.; Ur, C. A.; Valiente-Dobón, J. J.; Williams, S. J.; Zhang, Y. H.

2005-10-01

Several nuclei in the A ~ 190 region have been studied following deep-inelastic reactions using a 460 MeV 82Se projectile impinging upon a thick 192Os target. The GASP array (at the Legnaro National Laboratory in Italy) was used to measure the resulting γ-decays. The previously reported near-yrast structure of 191Os is extended to a t\\frac{1{2}} = 61 ns isomer, at an energy of 2640 keV. Branching ratios for ΔI = 1 and ΔI = 2 transitions in the Kπ =\\frac{11}{2}+ band have been measured, giving |(gK - gR)/Q0| = 0.022(3) and 0.024(7) for transitions from the \\frac{17}{2}+ and \\big(\\frac{19}{2}^+\\big) states respectively. These are consistent with the theoretical calculation for the proposed ν11/2+[615] configuration of the band. Nilsson plus BCS calculations reveal that the isomer is likely to have a {ν11/2+[615] π11/2-[505] π9/2-[514]} configuration with Jπ =Kπ =\\frac{31}{2}+ . This yields an implied reduced hindrance of fν= 1.9, in accordance with empirical systematics of K isomers in the A ~ 180-190 region.

Cranking model interpretation of weakly coupled bands in Hg isotopes

International Nuclear Information System (INIS)

Guttormsen, M.; Huebel, H.

1982-01-01

The positive-parity yrast states of the transitional sup(189-198)Hg isotopes are interpreted within the Bengtsson and Frauendorf version of the cranking model. The very sharp backbendings can be explained by small interaction matrix elements between the ground and s-bands. The experimentally observed large aligned angular momenta and the low band-crossing frequencies are well reproduced in the calculations. (orig.)

Isomeric and high-spin states of 94Tc and the search for yrast isomers near N~50

Science.gov (United States)

Lee, I. Y.; Johnson, N. R.; McGowan, F. K.; Young, G. R.; Guidry, M. W.; Yates, S. W.

1981-07-01

A search for isomers in the N~50 region has produced no evidence of high-spin yrast isomerism. A new 4.5-ns low-multiplicity isomer has been identified and assigned to 94Tc, while the yrast sequence of 94Tc has been established to more than 5 MeV in excitation energy. [NUCLEAR REACTIONS 76Ge, 78Se(20Ne,xnypγ), E=80.9 MeV, 89Y, 93Nb(10B,xnypγ), E=52.0,58.4,62.8 MeV; measured Eγ, Iγ, γ-γ prompt and delayed coin, γ-X coin; deduced levels, t12 of 94Tc isomer, yrast states.

Shifted identical bands: A new phenomenon

International Nuclear Information System (INIS)

Jones, E.F.; Lima, A.P. de; Gore, P.M.; Hamilton, J.H.; Ramayya, A.V.; Dodder, R.S.; Kormicki, J.; Hwang, J.K.; Beyer, C.J.; Zhang, X.Q.; Zhu, S.J.; Ter-Akopian, G.M.; Oganessian, Yu.Ts.; Daniel, A.V.; Rasmussen, J.O.; Lee, I.Y.; Cole, J.D.; Drigert, M.W.; Ma, W.-C.

2001-01-01

The levels in 162 Gd were identified in spontaneous fission studies. Its transition energies are remarkably similar to those in 160 Gd. From that work, an analysis of yrast bands in even-even proton to neutron-rich Ba to Pb nuclei led to the discovery of a new phenomenon, shifted identical bands (SIB). SIBs are yrast bands in neighboring nuclei (a, b) with moments of inertia which are identical when shifted by a constant amount κ, so J 1a (1 + κ) = J 1b , from 2 + to 8 + and higher to 16 + . Out of over 700 comparisons, 55 SIBs were found from stable to the most neutron-rich Ce-W nuclei with |κ-bar| between 1.5% and 13%, where the spread in κ is less than ± 1%, and only four identical bands (κ-bar congruent with 0). As examples, we found for 158 Sm- 160 Gd, κ-bar (-3.2 +0.1 -0.2 )% (where the ± is the total spread in κ from -3.1 to -3.4); 156 Nd- 160 Gd, (-10.6 +0.4 -0.2 )%; 158 Sm- 160 Sm, (3.4 +0.5 -0.3 )%. The J 1 values were fitted to a variable moment of inertia model with parameters J 0 and C whose values correlate with the SIB J 1 values. The SIBs are not correlated either with deformation or with the N p N n product of the IBA model

Isomeric and high-spin states of 94Tc and the search for yrast isomers near Napprox.50

International Nuclear Information System (INIS)

Lee, I.Y.; Johnson, N.R.; McGowan, F.K.; Young, G.R.; Guidry, M.W.; Yates, S.W.

1981-01-01

A search for isomers in the Napprox.50 region has produced no evidence of high-spin yrast isomerism. A new 4.5-ns low-multiplicity isomer has been identified and assigned to 94 Tc, while the yrast sequence of 94 Tc has been established to more than 5 MeV in excitation energy

Yrast and high spin states in 22Ne

International Nuclear Information System (INIS)

Szanto, E.M.; Toledo, A.S. de

1982-08-01

High spin states in 22 Ne have been investigated by the reactions 11 B( 13 C,d) 22 Ne and 13 C( 11 B,d) 22 Ne up to E* approximately=19 MeV. Yrast states were observed at 11.02 MeV (8 + ) and 15.46 MeV (10 + ) excitation energy. A backbending in 22 Ne is observed around spin 8 + . The location of high spin states I [pt

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)

Rapid Communication: v= 2 seniority changing transitions in yrast 3 ...

Indian Academy of Sciences (India)

Home; Journals; Pramana – Journal of Physics; Volume 89; Issue 5. Rapid Communication: Δ υ = 2 seniority changing transitions in yrast 3 − states and B ( E 3 ) systematics of Sn isotopes. BHOOMIKA MAHESHWARI SWATI GARG ASHOK KUMAR JAIN. Research Article Volume 89 Issue 5 November 2017 Article ID 75 ...

Microscopic study of low-lying yrast spectra and deformation ...

Indian Academy of Sciences (India)

73, No. 4. — journal of. October 2009 physics pp. 657–668. Microscopic study of low-lying yrast spectra and deformation systematics in neutron-rich. 98−106Sr isotopes ... with a large and rigid moment of inertia. 98Sr is predicted to have a ... 2 energy as neutron number N changes from 58 to 60. The onset of deformation in ...

Spins of superdeformed band in {sup 192}Hg

Energy Technology Data Exchange (ETDEWEB)

Lauritsen, T.; Khoo, T.L.; Henry, R.G. [and others

1995-08-01

Determination of the spins of SD states is the most important challenge in the study of superdeformation. Knowledge of the spin will provide crucial information on SD bands, in particular on the fascinating phenomenon of bands with identical energies and moments of inertia. Angular distribution coefficients of the {gamma}rays decaying out of the {sup 192}Hg SD band were determined using Eurogam data. These coefficients, as well as the spectral shape and multiplicity of the spectrum, are compared with the results of calculations, thereby providing a check on these calculations. From the measured decay multiplicity and the calculated average spin removed per photon (0.3 h), we deduce the average spin {bar I}{sub decay} removed by the {gamma} rays connecting SD and normal states. The spin I{sub SD} of the SD band from which the decay occurs is given by I{sub SD} = {bar I} decay + {bar I} ND, where {bar I} ND is the average spin removed by the normal yrast states. The state from which the major decay out of the SD band occurs is found to have spin 9.5 {plus_minus} 0.8 h. Since angular momentum is (quantized), this leads to a spin assignment of 9 or 10 h. The latter value is favored since the yrast band in the SD well must have only even spin values. This constitutes the first deduction of spin from data in the mass 150 and 190 regions. The spin of 10 h agrees with the spin which is inferred from a model, using the observed moment of inertia (Im){sup (2)}{omega}.

Nuclear structure far above the yrast line

International Nuclear Information System (INIS)

Gaardhoeje, J.J.

1985-01-01

The phase space available for gamma ray spectroscopic studies has recently been extended significantly with the observation of gamma radiation produced in the decay of highly collective (isovector) giant dipole resonances (GDR), built on excited states of high spin, in nuclei produced in heavy ion induced fusion reactions. These gamma rays are predominantly emitted in competition with particles in the first few steps of the decay of compound systems and constitute an entirely new tool to study nuclei at excitation energies far above the yrast line. Some problems of current central interest are addressed. (Auth.)

Yrast spectroscopy in {sup 49-51}Ti via fusion-evaporation reaction induced by a radioactive beam

Energy Technology Data Exchange (ETDEWEB)

Niikura, M.; Ideguchi, E.; Michimasa, S.; Ota, S.; Shimoura, S.; Wakabayashi, Y. [University of Tokyo, Center for Nuclear Study, Wako, Saitama (Japan); Aoi, N.; Baba, H.; Fukuchi, T.; Ichikawa, Y.; Kubo, T.; Kurokawa, M.; Ohnishi, T.; Suzuki, H.; Yoshida, K. [RIKEN Nishina Center, Wako, Saitama (Japan); Iwasaki, H.; Onishi, T.K.; Suzuki, D. [University of Tokyo, Department of Physics, Tokyo (Japan); Liu, M.; Zheng, Y. [Chinese Academy of Sciences, Institute of Modern Physics, Lanzhou (China)

2009-12-15

In-beam {gamma} -ray spectroscopy of high-spin states in {sup 49-51}Ti was performed via the fusion-evaporation reaction using a radioactive beam. By excitation function and {gamma} - {gamma} coincidence analysis, yrast high-spin levels up to I=(21/2{sup -}),(11{sup +}),(17/2{sup -}) in {sup 49-51}Ti were determined. The levels were compared with full-pf -shell model calculation. The level structure indicates the persistency of the N=28 shell gap at yrast states in {sup 49-51}Ti. (orig.)

Pseudo SU(3) shell model: Normal parity bands in odd-mass nuclei

International Nuclear Information System (INIS)

Vargas, C.E.; Hirsch, J.G.; Draayer, J.P.

2000-01-01

A pseudo shell SU(3) model description of normal parity bands in 159 Tb is presented. The Hamiltonian includes spherical Nilsson single-particle energies, the quadrupole-quadrupole and pairing interactions, as well as three rotor terms. A systematic parametrization is introduced, accompanied by a detailed discussion of the effect each term in the Hamiltonian has on the energy spectrum. Yrast and excited band wavefunctions are analyzed together with their B(E2) values

Competition between pairing and quadrupole deformation in the yrast sequence of sup(150,152)Dy

International Nuclear Information System (INIS)

Aberg, S.

1984-05-01

The yrast spectra are investigated for the non-collective nuclei sup(150,152)Dy using the Nilsson-Strutinsky + blocked BCS model. The separate effects from the pairing force and the quadrupole force (deformation changes) are studied. It is found that the pairing force is most important in describing the yrast line up to Iproportional30, while the quadrupole force is most important for I> or approx.20. The calculated increase of the oblate deformation with increasing spin is explained as an antipairing effect when only valence nucleons are building the total spin and as a polarization effect when the core becomes excited. (orig.)

Lifetimes of an excited superdeformed band in {sup 192}Hg

Energy Technology Data Exchange (ETDEWEB)

Ahmad, I.; Blumenthal, D.; Carpenter, M.P. [and others

1995-08-01

An excited superdeformed band was identified in {sup 192}Hg and the lifetimes of its levels measured with the Doppler-shift attenuation method from data taken with the Eurogam spectrometer. The band is proposed to be based on the two-quasineutron (v[642]3/2 [512]5/2) configuration, which after a band crossing, becomes the (v[642]3/2 [752]5/2) configuration. The transition quadrupole moment Q{sub t} of the excited band is the same as that of the yrast SD band, within experimental errors. This suggests that the deformation of the SD minimum is robust with respect to quasiparticle excitation, despite the occupation of the deformation-driving v[752]5/2 level (from the j{sub 15/2} shell) after the band crossing.

Studies of yrast and continuum states in A=140-160 nuclei. Progress report, January 1, 1980-December 31, 1980

International Nuclear Information System (INIS)

Daly, P.J.

1981-01-01

The structure of nuclei in the A approx. 150 region was investigated by in-beam γ-ray spectroscopy using heavy-ion beams, mostly from the Argonne Tandem-Linac. Results for the nuclei 148 Dy, 149 Dy, 153 Dy, 154 Dy, 149 Ho, and 150 Ho are summarized. The feeding of yrast states in these nuclei and the link between the highest known yrast states and the continuum region were also studied. 6 figures

Constrained-path quantum Monte Carlo approach for non-yrast states within the shell model

Energy Technology Data Exchange (ETDEWEB)

Bonnard, J. [INFN, Sezione di Padova, Padova (Italy); LPC Caen, ENSICAEN, Universite de Caen, CNRS/IN2P3, Caen (France); Juillet, O. [LPC Caen, ENSICAEN, Universite de Caen, CNRS/IN2P3, Caen (France)

2016-04-15

The present paper intends to present an extension of the constrained-path quantum Monte Carlo approach allowing to reconstruct non-yrast states in order to reach the complete spectroscopy of nuclei within the interacting shell model. As in the yrast case studied in a previous work, the formalism involves a variational symmetry-restored wave function assuming two central roles. First, it guides the underlying Brownian motion to improve the efficiency of the sampling. Second, it constrains the stochastic paths according to the phaseless approximation to control sign or phase problems that usually plague fermionic QMC simulations. Proof-of-principle results in the sd valence space are reported. They prove the ability of the scheme to offer remarkably accurate binding energies for both even- and odd-mass nuclei irrespective of the considered interaction. (orig.)

ΔI=4 bifurcation in a superdeformed band: Evidence for a C4 symmetry

International Nuclear Information System (INIS)

Flibotte, S.; Andrews, H.R.; Ball, G.C.; Beausang, C.W.; Beck, F.A.; Belier, G.; Byrski, T.; Curien, D.; Dagnall, P.J.; de France, G.; Disdier, D.; Duchene, G.; Finck, C.; Haas, B.; Hackman, G.; Haslip, D.S.; Janzen, V.P.; Kharraja, B.; Lisle, J.C.; Merdinger, J.C.; Mullins, S.M.; Nazarewicz, W.; Radford, D.C.; Rauch, V.; Savajols, H.; Styczen, J.; Theisen, C.; Twin, P.J.; Vivien, J.P.; Waddington, J.C.; Ward, D.; Zuber, K.; Aberg, S.

1993-01-01

The moment of inertia of the yrast superdeformed band in 149 Gd exhibits an unexpected bifurcation at high rotational frequency. States differing by four units of angular momentum show an energy shift of about 60 eV. This indicates the remnant of a new quantum number associated with the fourfold rotational symmetry

High spin states in 63Cu. 17/2+ isomeric yrast state

International Nuclear Information System (INIS)

Tsan Ung Chan; Bruandet, J.F.; Dauchy, A.; Giorni, A.; Glasser, F.; Morand, C.; Chambon, B.; Drain, D.

1979-01-01

The 63 Cu nucleus has been studied via the reaction 61 Ni(α, pnγ), using different in beam γ spectroscopy techniques. An isomeric high-spin Yrast state 17/2 + (tau = 6.1 +- 0.6ns) is located at 4498 keV. The gsub(9/2) shell must be involved to explain positive high-spin states established in this work [fr

Spectroscopy high above the yrast line in rare earth nuclei

International Nuclear Information System (INIS)

Ramsoey, T.

1990-01-01

The particle-gamma coincidence technique presented in this work has proved to be a powerful tool in the study of nuclear structure. The most important feature is the ability to select well-defined excitation regions of entry states in a narrow spin window. The author has focused on the gamma-decay of low- lying descrete states and the gross structure properties in the region far above the yrast line. 6 refs., 5 figs

Conversion coefficients and yrast state spins in 180Os

International Nuclear Information System (INIS)

Dracoulis, G.D.; Kibedi, T.; Byrne, A.P.; Fabricius, B.; Stuchbery, A.E.

1989-11-01

Internal conversion coefficients of transitions in 180 Os have been measured using a superconducting, solenoidal electron spectrometer, operated in the lens mode. The high energy resolution and efficiency allow a precise measurement of the conversion coefficients of the 528 keV yrast transition. The values obtained, α K = 0.015 (2), α L = 0.004(1) define pure E2 multipolarity. Taken with the measured γ-ray angular distribution, the conversion coefficient leads to an unambiguous assignment of 16 + →14 + for the 528 keV transition. 14 refs., 5 figs., 1 tab

Design of a Compton-suppression spectrometer and its application to the study of high-spin yrast states

International Nuclear Information System (INIS)

Aarts, H.J.M.

1981-01-01

Detailed γ-ray spectroscopy of high-spin states is hampered by transitions with low intensity on a high γ-ray background. An approach to enhance weak peaks in a spectrum in the reduction of the Compton background by means of a Compton-suppression spectrometer (CSS). Optimization of a CSS by means of Monte Carlo calculations is described. The investigation of high-spin states in the sd-shell nucleus 38 Ar with a Compton-suppression spectrometer is reported. With previously described techniques, in combination with p-γ coincidence measurements to establish an unambiguous level scheme, states up to Jsup(π) = 11 - could be identified and investigated. A gamma-gamma coincidence experiment on the nuclei 167 168 Hf is described with two Compton-suppression spectrometers. Yrast bands are followed, beyond the region of the first backbending, up to spin J = 37/2 and J = 28 for 167 Hf and 168 Hf, respectively. (Auth.)

Toward yrast spectroscopy in soft vibrational nuclei. A microscopic theory of the large amplitude collective motion of soft nuclei

International Nuclear Information System (INIS)

Marumori, Toshio; Kuriyama, Atsushi; Sakata, Fumihiko

1980-01-01

In a formally parallel way with that exciting progress has been recently achieved in understanding the yrast spectra of the rotational nuclei in terms of the quasi-particle motion in the rotating frame, an attempt to understand the yrast spectra of the vibrational nuclei in terms of the quasi-particle motion is proposed. The essential idea is to introduce the quasi-particle motion in a generalized vibrating frame, which can be regarded as a rotating frame in the gauge space of 'physical' phonons where the number of the physical phonons plays the role of the angular momentum. On the basis of a simple fundamental principle called as the 'invariance principle of the Schroedinger equation', which leads us to the 'maximal decoupling' between the physical phonon and the intrinsic modes, it is shown that the vibrational frame as well as the physical-phonon-number operator represented by the quasi-particles can be self-consistently determined. A new scope toward the yrast spectroscopy of the vibrational nuclei in terms of the quasi-particle motion is discussed

Entrance-channel effects in the population of superdeformed bands

Energy Technology Data Exchange (ETDEWEB)

Smith, G.; Haas, B.; Alderson, A.; Ali, I.; Beausang, C.W.; Bentley, M.A.; Dagnall, P.; Fallon, P.; de France, G.; Forsyth, P.D.; Huttmeier, U.; Romain, P.; Santos, D.; Twin, P.J.; Vivien, J.P. (Oliver Lodge Laboratory, University of Liverpool, Liverpool L69 3BX (United Kingdom) Centre de Recherches Nucleaires, F-67037 Strasbourg CEDEX (France) Sciences and Engineering Research Council, Daresbury Laboratory, Warrington WA44AD (United Kingdom))

1992-01-13

In order to investigate whether entrance-channel effects influence the production of superdeformed nuclei, we have measured the yield of the yrast superdeformed band in {sup 152}Dy populated via nearly mass-symmetric ({sup 82}Se+{sup 74}Ge) and mass-asymmetric ({sup 48}Ca+{sup 108}Pd, {sup 36}S+{sup 120}Sn) fusion reactions leading to the same compound nucleus at similar excitation energies and angular momenta. Large differences in the relative intensity of the band compared with the total yield of the nucleus are observed in the various reactions. This effect indicates that the competition between fission and neutron evaporation is affected by the mode of formation of the fusing system.

Investigation of band structure of {sup 103,105}Rh using microscopic computational technique

Energy Technology Data Exchange (ETDEWEB)

Kumar, Amit, E-mail: akbcw2@gmail.com [Research Scholar, Department of Physics and Electronics, University of Jammu, Jammu-180006 (India); Singh, Suram, E-mail: suramsingh@gmail.com [Assistant Professor, Department of Physics Govt. Degree College, Kathua-184142 (India); Bharti, Arun, E-mail: arunbharti-2003@yahoo.co.in [Professor, Department of Physics and Electronics, University of Jammu, Jammu-180006 (India)

2015-08-28

The high-spin structure in {sup 61}Cu nucleus is studied in terms of effective two body interaction. In order to take into account the deformed BCS basis, the basis states are expanded in terms of the core eigenfunctions. Yrast band with some other bands havew been obtained and back-bending in moment of inertia has also been calculated and compared with the available experimental data for {sup 61}Cu nucleus. On comparing the available experimental as well as other theoretical data, it is found that the treatment with PSM provides a satisfactory explanation of the available data.

The quasi-continuum of gamma rays following the decay of superdeformed bands in the Hg region

Energy Technology Data Exchange (ETDEWEB)

Lauritsen, T.; Khoo, T.L.; Janssens, R.V.F. [Argonne National Lab., IL (United States)] [and others

1996-12-31

The quasi-continuum part of the spectrum associated with the decay-out of the yrast superdeformed band in {sup 194}Hg has been extracted. It has for the first time been possible to compare the spin and excitation energy determined from the analysis of the quasi-continuum {gamma} rays to the exact result obtained from the one-step linking transitions.

The low lying yrast structure of 212Po

International Nuclear Information System (INIS)

Poletti, A.R.; Dracoulis, G.D.; Byrne, A.P.; Stuchbery, A.E.

1987-07-01

The properties of states in 212 Po populated by the 208 Pb( 9 Be,αn) 212 Po reaction have been investigated. the previously proposed yrast scheme below 3MeV has been verified and eight further transitions placed in the level scheme. Mean lives of the 6 + , 8 + and (10 + ) states at 1355, 1476 and 1834 keV have been measured as 1.1(3), 24.6(3) and 0.8(2)ns respectively. Shell model calculations using effective interactions were used to interpret the observed scheme. A synthesis of all available theoretical and experimental evidence allows the 65s isomer to be identified clearly as the 18 + level arising primarily from the π(h 9/2 2 )*ν(g 9/2 i 11/2 ) configuration

In-beam γ-ray spectroscopy of N=84 nuclei above Gd and the impact of the (πh11/2νh9/2)1+ attraction on their yrast lines

International Nuclear Information System (INIS)

Zhang Chengteng.

1993-12-01

In in-beam experiments using the γ-spectrometers Nordball at the Niels Bohr Institute and Osiris at the Hahn-Meitner Institute we populated the four N = 84 isotones 151 Ho, 152 Er, 153 Tm and 154 Yb through compound evaporation reactions induced with medium HI beams of masses ranging from 28 to 56. All observed γ-transitions with intensities above 1% (5% in 154 Yb) of the respective exit channel were placed in the level schemes, with spins established up to 10 MeV (8 MeV for 154 Yb) and parties up to between 5 and 7 MeV. We have found that in these N = 84 nuclei the multi-valence particle configurations πh n 11/2 νf 2 7/2 and πh n 11/2 νf 7/2 h 9/2 are strongly populated in the yrast cascades, and we have observed them up to their maximum spins of 43/2 - in Ho (at 4.8 MeV), 24 + in Er (7.5 MeV), 51/2 - in Tm (6.9 MeV), and only up to 24 + in Yb, 0.5 MeV below the fully aligned 26 + state expected at 9.1 MeV. The πh n νf 2 configuration forms smooth sections of the yrast line, while the more irregular yrast line of the πh n νfh character reflects the strong (νfh)8 + two-body attraction which gives rise to pronounced yrast line dips. We have also carried out full shell model calculations of these yrast lines, which are in excellent agreement with the experimental data. Since we take all dynamic input values, i.e. the two-body matrix elements and the single particle energies, from experiment, the calculations are free of any adjusted parameter. An interesting new result is the systematic identification in the πh n 11/2 νfh configuration of yrast states formed by specific proton couplings, where the strongly attractive (πh 11/2 νh 9/2 )1 + interaction is activated. As a consequence these states drop down to the yrast lines and in energy below the maximum aligned state of the next lower proton seniority. These seniority inverted yrast states were systematically identified in the four N = 84 nuclei, including two such states in 153 T, the first N 84

The collectivity and the de-excitation of the yrast superdeformed band in sup 150 Gd

Energy Technology Data Exchange (ETDEWEB)

Fallon, P.; Alderson, A.; Ali, I.; Cullen, D.M.; Forsyth, P.D.; Riley, M.A.; Roberts, J.W.; Sharpey-Schafer, J.F.; Twin, P.J. (Liverpool Univ. (UK). Oliver Lodge Lab.); Bentley, M.A.; Bruce, A.M. (Science and Engineering Research Council, Daresbury (UK). Daresbury Lab.)

1991-03-28

A Doppler shift attenuation measurement has been carried out to determine the collectivity of the superdeformed band in {sup 150}Gd. The data was found to be consistent with a constant inband quadrupole moment of 17+-3 eb. This corresponds to a quadrupole deformation of {beta}{sub 2}{approx equal}0.58. In addition the measurement has resolved important questions regarding the de-excitation of the band, confirming the rapid de-excitation of the superdeformed band in {sup 150}Gd with more than 80% of the band intensity being lost over one transition. (orig.).

The low-lying yrast structure of 212Po

International Nuclear Information System (INIS)

Poletti, A.R.; Dracoulis, G.D.; Byrne, A.P.; Stuchbery, A.E.

1987-01-01

The properties of states in 212 Po populated by the 208 Pb( 9 Be,αn) 212 Po reaction have been investigated. The previously proposed yrast scheme below ≅ 3 MeV has been verified and eight further transitions placed in the level scheme. Mean lives of the 6 + , 8 + and (10 + ) states at 1355, 1476 and 1834 keV have been measured at 1.1 (3), 24.6 (3) and 0.8 (2) ns respectively. Shell model calculations using effective interactions were used to interpret the observed scheme. A synthesis of all available theoretical and experimental evidence allows the τ m = 65 s isomer to be identified clearly as the 18 + level arising primarily from the π(h 2 9/2 ) * ν(g 9/2 i 11/2 ) configuration. (orig.)

Wobbling Motion in the Multi-Bands Crossing Region: Dynamical Coupling Mode Between High- and Low-K States

International Nuclear Information System (INIS)

Oi, M.; Ansari, A.; Horibata, T.; Onishi, N.; Walker, P.M.

2001-01-01

We analyze a mechanism of coupling of high- and low-K bands in terms of a dynamical treatment for nuclear rotations, i. e., wobbling motion. The wobbling states are produced through the Generator Coordinate Method after Angular Momentum Projection (GCM-after-AMP), in which the intrinsic states are constructed through fully self consistent calculations by the 2d-cranked (or tilted-axis-cranked) HFB method. In particular, the phenomena of ''signature inversion'' and ''signature splitting'' in the t-band (tilted rotational band) are explained in terms of the wobbling model. Our calculations will be compared with new data for in-band E2 transition rates in 182 0s, which may shed light on the mechanism of the anomalous K = 25 isomer decay, directly to the yrast band. (author)

First excited states in doubly-odd 110Sb: Smooth band termination in the A ∼ 110 region

International Nuclear Information System (INIS)

Lane, G.J.; Fossan, D.B.; Thorslund, I.

1996-01-01

Excited states have been identified for the first time in 110 Sb in a comprehensive series of γ-spectroscopy experiments, including recoil-mass and neutron-field measurements. Three high-spin decoupled bands with configurations based on 2p-2h excitations across the Z = 50 shell gap, are observed to show the features of smooth band termination, the first such observation in an odd-odd nucleus. The yrast intruder band has been connected to the low spin levels and is tentatively identified up to its predicred termination at I π = (45 + ). Detailed configuration assignments are made through comparison with configuration-dependent cranked Nilsson-Strutinsky calculations; excellent agreement with experiment is obtained. The systematic occurrence of smoothly terminating bands in the neighboring isotopes is discussed

Triaxial energy relation to describe rotational band in 98-112Ru nuclei

International Nuclear Information System (INIS)

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

2010-01-01

In a broader perspective rotation vibration coupling parameter (b) is considered changing with the change in excitation energy (ε 1 ) and is evaluated on fitting experimental energy for 98-112 Ru isotopes in the frame work of general asymmetric rotor model. The moment of inertia parameter (a), common to yrast and quasi-γ band, is calculated from deformation parameter (β) using general empirical relation. The present work is undertaken to suggest some suitable equation for the trajectories which are similar in shape in 98-112 Ru nuclei

Investigation of octupole deformations in the Fr217 nucleus by yrast spectroscopy

International Nuclear Information System (INIS)

Hulne, S.

1988-01-01

The spectroscopic characteristics of the yrast levels of Fr217 are determined. The level scheme up to a value of J = (39/2 + ) for angular momentum and parity is established. The production of the Fr217 nucleus in a heavy ion collision reaction was only possible by using a radioactive Pb210 target. The method for preparing the target is described. The Fr217 nucleus belongs to the category of nuclei showing octupole effects. Mass A = 217 seems to be the lower limit of the region where these effects occur [fr

Decay from the superdeformed bands in 194Hg

International Nuclear Information System (INIS)

Henry, R.G.; Khoo, T.L.; Carpenter, M.P.

1995-01-01

Superdeformed bands in 194 H g were studied using the early implementation of Gammasphere. The response functions for the Ge detectors were measured for the first time as part of this experiment. Experiments were performed with both a backed target (where the residue stopped in the Au backing) and a thin target (where the residue recoiled into vacuum). This will permit measurements of the decay times of the quasicontinuum γrays. The spectrum in coincidence with the yrast SD band in 194 Hg reveals the same features as found in the quasicontinuum structure in 192 Hg. These features include: statistical γrays feeding the SD band, a pronounced E2 peak from transitions feeding the SD band, a Ml/E2 bump at low energies that is associated with the last stages of feeding of the superdeformed band, and a quasicontinuous distribution from γrays linking SD and normal states, including a sizable clustering of strength around 1.7 MeV. The remarkable similarity of the spectra coincident with SD bands in 192,194 Hg provides additional support for a statistical process for decay out of the SD states. This similarity contrasts with differences observed in the spectrum coincident with the SD band in the odd-even 191 Hg, confirming the predictions about the role of pairing (in normal states) in influencing the shape of the decay-out spectrum

Structure of negative parity yrast bands in odd mass 125−131Ce ...

Indian Academy of Sciences (India)

gion close to the N = 82 shell gap and have been the subject of many experimen- tal studies as these nuclei exhibit a competition between spherical and deformed ... 127Ce nucleus [5,6] three bands were identified: two based on 5/2+ and ...

Band crossing and signature splitting in odd mass fp shell nuclei

International Nuclear Information System (INIS)

Velazquez, Victor; Hirsch, Jorge G.; Sun, Yang

2001-01-01

Structure of two sets of mirror nuclei: 47 V- 47 Cr and 49 Cr- 49 Mn, as well as 49 V and 51 Mn, is studied using the projected shell model. Their yrast spectra are described as an interplay between the angular momentum projected states around the Fermi level which carry different intrinsic K-quantum numbers. The deviations from a regular rotational sequence are attributed to band crossing and signature splitting, which are usually discussed in heavy nuclear systems. Our results agree reasonably with experimental data, and are comparable with those from the full pf shell model calculations

The decay-out of superdeformed bands in the A = 190 region. What have we learned?

International Nuclear Information System (INIS)

Lauritsen, T.; Hackman, G.; Khoo, T.L.; Carpenter, M.P.; Janssens, R.V.F.; Ackermann, D.; Ahmad, I.; Blumenthal, D.J.; Lopez-Martens, A.

1997-01-01

One-step decay transitions linking the superdeformed (SD) bands 1 and 3 in 194 Hg to yrast levels are discussed. Inter-band transitions between bands 1 and 3 have also been identified. For the first time, the spin, parity and excitation energy have been determined for two SD bands in the same nucleus. The low excitation energy of the excited band supports the view that it is based on an octupole excitation. It is believed that Porter-Thomas fluctuations play a major role in determining the strength of the one-step transitions as suggested by the fact that only one other SD band has been linked in the A = 190 mass region ( 194 Pb) at the present time. When Porter-Thomas fluctuations prevent the observation of one-step or two-step linking transitions, as e.g. in the case of 192 Hg, the analysis of the quasi-continuous part of the decay-out spectrum provides an alternative method for the determination of the excitation energy and spin of an SD band. This method is discussed in detail. (author)

Intensity profiles of superdeformed bands in Pb isotopes in a two-level mixing model

International Nuclear Information System (INIS)

Wilson, A. N.; Szigeti, S. S.; Rogers, J. I.; Davidson, P. M.; Cardamone, D. M.

2009-01-01

A recently developed two-level mixing model of the decay out of superdeformed bands is applied to examine the loss of flux from the yrast superdeformed bands in 192 Pb, 194 Pb, and 196 Pb. Probability distributions for decay to states at normal deformations are calculated at each level. The sensitivity of the results to parameters describing the levels at normal deformation and their coupling to levels in the superdeformed well is explored. It is found that except for narrow ranges of the interaction strength coupling the states, the amount of intensity lost is primarily determined by the ratio of γ decay widths in the normal and superdeformed wells. It is also found that while the model can accommodate the observed fractional intensity loss profiles for decay from bands at relatively high excitation, it cannot accommodate the similarly abrupt decay from bands at lower energies if standard estimates of the properties of the states in the first minimum are employed

Triaxiality and the wobbling mode In 167Lu

International Nuclear Information System (INIS)

Amro, H.; Ma, W.C.; Winger, J.A.; Li, Y.; Thompson, J.; Hagemann, G.; Herskind, B.; Sletten, G.; Wilson, J.N.; Jensen, D.R.; Fallon, P.; Ward, D.; Diamond, R.M.; Goergen, A.; Machiavelli, A.; Huebel, H.; Domscheit, J.; Wiedenhoewer, I.

2002-01-01

High spin states in 167Lu nucleus were populated through the 123Sb(48Ca,xn) reaction at 203 MeV. Five presumably triaxial superdeformed (TSD) bands have been found. The electromagnetic properties of several connecting transitions between the yrast (TSD1) and the excited (TSD2) bands have been established. Evidence for the assignment of TSD2 band as a wobbling mode built on the yrast TSD band is presented. These bands coexist with bands built on quasiparticle excitations in normal deformed (ND) minimum for which new data are also presented

Lifetime measurements and dipole transition rates for superdeformed states in {sup 190}Hg.

Energy Technology Data Exchange (ETDEWEB)

Amro, H.

1999-03-24

The Doppler-shift attenuation method was used to measure life-times of superdeformed (SD) states for both the yrast and the first excited superdeformed band of {sup 190}Hg. Intrinsic quadruple moments Q{sub 0} were extracted. For the first time, the dipole transition rates have been extracted for the inter-band transitions which connect the excited SD band to the yrast states in the second minimum. The results support the interpretation of the excited SD band as a rotational band built on an octupole vibration.

Lifetime measurements and dipole transition rates for superdeformed states in 190Hg

International Nuclear Information System (INIS)

Amro, H.

1999-01-01

The Doppler-shift attenuation method was used to measure life-times of superdeformed (SD) states for both the yrast and the first excited superdeformed band of 190 Hg. Intrinsic quadruple moments Q 0 were extracted. For the first time, the dipole transition rates have been extracted for the inter-band transitions which connect the excited SD band to the yrast states in the second minimum. The results support the interpretation of the excited SD band as a rotational band built on an octupole vibration

Band structure in 83Rb from lifetime measurements

International Nuclear Information System (INIS)

Ganguly, S.; Banerjee, P.; Ray, I.; Kshetri, R.; Bhattacharya, S.; Saha-Sarkar, M.; Goswami, A.; Muralithar, S.; Singh, R.P.; Kumar, R.; Bhowmik, R.K.

2006-01-01

Excited states of 83 Rb, populated in the 76 Ge( 11 B,-bar 4nγ) reaction at a beam energy of 50 MeV, have been studied. The unfavoured signature partner (α=-1/2) of the πg 9/2 yrast band is proposed up to an excitation energy of 6669.4 keV and spin (31/2 + ). Lifetimes have been estimated for three states belonging to the favoured α=+1/2 band. The B(E2) values deduced from these lifetimes indicate a moderate quadrupole deformation of β 2 =0.20. Theoretical calculations within the framework of the particle-rotor-model suggest that low energy states before the onset of the νg 9/2 alignment at a rotational frequency of ∼0.5 MeV are prolate while those above this frequency have an oblate shape. The excited ΔI=1 band has been extended up to 5422.7 keV and spin 25/2 - . The B(M1) rates derived from the measured lifetimes decrease with spin. The results are in general agreement with an earlier TAC calculation, suggesting the interpretation of these states as arising from magnetic rotation

Search for two-{gamma} sum-energy peaks in the decay out of superdeformed bands

Energy Technology Data Exchange (ETDEWEB)

Blumenthal, D.; Khoo, T.L.; Lauritsen, T. [and others

1995-08-01

The spectrum of {gamma}rays decaying out of the superdeformed (SD) band in {sup 192}Hg has a quasicontinuous distribution. Whereas methods to construct level schemes from discrete lines in coincidence spectra are well established, new techniques must still be developed to extract information from coincidences involving quasicontinuous {gamma}rays. From an experiment using Eurogam, we obtained impressively clean 1- and 2-dimensional {gamma} spectra from pairwise or single gates, respectively, on the transitions of the SD band in {sup 192}Hg. We investigated methods to exploit the 2-dimensional quasicontinuum spectra coincident with the SD band to determine the excitation energy of the SD band above the normal yrast line. No strong peaks were observed in the 2-{gamma} sum spectra; only candidates of peaks at a 2-3 {sigma} level were found. This suggests that 2-{gamma} decay is not the dominant decay branch out of SD bands, consistent with the observed multiplicity of 3.2. We shall next search for peaks in sum-spectra of 3 {gamma}s.

Decay from the superdeformed bands in {sup 194}Hg

Energy Technology Data Exchange (ETDEWEB)

Henry, R.G.; Khoo, T.L.; Carpenter, M.P. [and others

1995-08-01

Superdeformed bands in {sup 194}H g were studied using the early implementation of Gammasphere. The response functions for the Ge detectors were measured for the first time as part of this experiment. Experiments were performed with both a backed target (where the residue stopped in the Au backing) and a thin target (where the residue recoiled into vacuum). This will permit measurements of the decay times of the quasicontinuum {gamma}rays. The spectrum in coincidence with the yrast SD band in {sup 194}Hg reveals the same features as found in the quasicontinuum structure in {sup 192}Hg. These features include: statistical {gamma}rays feeding the SD band, a pronounced E2 peak from transitions feeding the SD band, a Ml/E2 bump at low energies that is associated with the last stages of feeding of the superdeformed band, and a quasicontinuous distribution from {gamma}rays linking SD and normal states, including a sizable clustering of strength around 1.7 MeV. The remarkable similarity of the spectra coincident with SD bands in {sup 192,194}Hg provides additional support for a statistical process for decay out of the SD states. This similarity contrasts with differences observed in the spectrum coincident with the SD band in the odd-even {sup 191}Hg, confirming the predictions about the role of pairing (in normal states) in influencing the shape of the decay-out spectrum.

Identification of 162Gd and a new type of identical bands

International Nuclear Information System (INIS)

Jones, E. F.; Gore, P. M.; Hamilton, J. H.; Ramayya, A. V.; Dodder, R. S.; Beyer, C. J.; Hwang, J. K.; Zhang, X. Q.; Kormicki, J.; Zhu, S. J.; Lima, A. P. de; Cole, J. D.; Aryaeinejad, R.; Ma, W. C.; Ter-Akopian, G. M.; Daniel, A. V.; Oganessian, Yu. Ts.; Rasmussen, J. O.; Asztalos, S. J.; Lee, I. Y.

1998-01-01

From γ-γ-γ coincidence measurements in spontaneous fission of 252 Cf, level energies were established to spins 14 + to 20 + in many neutron-rich nuclei. New isotope 162 Gd was identified. Yrast bands of 152,154,156 Nd, 156,158,160 Sm, and 160,162 Gd exhibit near-identical transition energies and moments of inertia (MOI) shifted by the same constant amounts for every spin state from 2 + to 12 + or 14 + for nuclei differing by 2n, 4n, 2p, 4p, α, α+2p, and α+2n. These shifted identical bands (SIB) are a new phenomenon. Analysis of all known even-even proton- to neutron-rich nuclei from Ba(Z=56) to Os(Z=76) reveal no SIB for proton-rich nuclei and few cases of SIB for the most neutron-rich pairs around N=98-102 separated by 2n and 2p

Feeding times of high spin states in sup(152,154)Dy: Probes of nuclear structure above the yrast line

International Nuclear Information System (INIS)

Azgui, F.; Emling, H.; Grosse, E.; Michel, C.; Simon, R.S.; Spreng, W.; Wollersheim, H.J.; Khoo, T.L.; Chowdhury, P.; Frekers, D.; Janssens, R.V.F.; Pakkanen, A.; Daly, P.J.; Kortelahti, M.; Schwalm, D.; Seiler-Clark, G.

1985-01-01

Measurements of feeding times of high spin yrast states up to spin 30 (h/2π) in 154 Dy and 36 (h/2π) in 152 Dy were utilized to obtain information about possible spin dependent shape changes. The reactions 25 Mg ( 134 Xe, 5n), 124 Sn ( 34 S, 4n) and 25 Mg ( 132 Xe, 5n), 122 Sn ( 34 S, 4n) were used to populate the high spin states in 154 Dy and 152 Dy, respectively. Feeding times as well as lifetimes were determined with the recoil distance technique. In 152 Dy only long feeding times (>=10 ps) could be identified, indicating that the aligned-particle yrast states are fed through configurations of similar character, with little direct population from collective cascades in the continuum region. In 154 Dy discrete states with I<=30 (h/2π) have lifetimes which are characteristically collective, whereas the preyrast cascades exhibit both fast (< or approx.1 ps) and slow (proportional10 ps) feeding components. The latter imply a change with increasing spin from collective to aligned-particle character, probably associated with a prolate to oblate shape transition. (orig.)

Spectra of γ rays feeding superdeformed bands

International Nuclear Information System (INIS)

Lauritsen, T.; Khoo, T.L.; Henry, R.G.

1995-01-01

The spectrum of γrays coincident with SD transitions contains the transitions which populate the SD band. This spectrum can provide information on the feeding mechanism and on the properties (moment of inertia, collectivity) of excited SD states. We used a model we developed to explain the feeding of SD bands, to calculate the spectrum of feeding γrays. The Monte Carlo simulations take into account the trigger conditions present in our Eurogam experiment. Both experimental and theoretical spectra contain a statistical component and a broad E2 peak (from transitions occurring between excited states in the SD well). There is good resemblance between the measured and calculated spectra although the calculated multiplicity of an E2 bump is low by ∼30%. Work is continuing to improve the quality of the fits, which will result in a better understanding of excited SD states. In addition, a model for the last steps, which cool the γ cascade into the SD yrast line, needs to be developed. A strong M1/E2 low-energy component, which we believe is responsible for this cooling, was observed

Spectra of {gamma} rays feeding superdeformed bands

Energy Technology Data Exchange (ETDEWEB)

Lauritsen, T.; Khoo, T.L.; Henry, R.G. [and others

1995-08-01

The spectrum of {gamma}rays coincident with SD transitions contains the transitions which populate the SD band. This spectrum can provide information on the feeding mechanism and on the properties (moment of inertia, collectivity) of excited SD states. We used a model we developed to explain the feeding of SD bands, to calculate the spectrum of feeding {gamma}rays. The Monte Carlo simulations take into account the trigger conditions present in our Eurogam experiment. Both experimental and theoretical spectra contain a statistical component and a broad E2 peak (from transitions occurring between excited states in the SD well). There is good resemblance between the measured and calculated spectra although the calculated multiplicity of an E2 bump is low by {approximately}30%. Work is continuing to improve the quality of the fits, which will result in a better understanding of excited SD states. In addition, a model for the last steps, which cool the {gamma} cascade into the SD yrast line, needs to be developed. A strong M1/E2 low-energy component, which we believe is responsible for this cooling, was observed.

Collective motions and band structures in A = 60 to 80, even--even nuclei

International Nuclear Information System (INIS)

Hamilton, J.H.; Robinson, R.L.; Ramayya, A.V.

1978-01-01

Evidence for and the theoretical understanding of the richness of the collective band structures as illustrated by at least seven bands seen in levels of 68 Ge, 74 Se are reviewed. The experimental data on even-even nuclei in the A = 60 to 80 region have now revealed a wide variety of collective bands with different structures. The even parity yrast cascades alone are seen to involve multiple collective structures. In addition to the ground-state bands, strong evidence is presented for both neutron and proton rotation-aligned bands built on the same orbital, (g 9 / 2 ) 2 , in one nucleus. Several other nuclei also show the crossing of RAL bands around the 8 + level in this region. Evidence continues to be strong experimentally and supported theoretically that there is some type of shape transition and shape coexistence occurring now both in the Ge and Se isotopes around N = 40. Negative parity bands with odd and even spins with very collective nature are seen in several nuclei to high spin. These bands seem best understood in the RAL model. Very collective bands with ΔI = 1, extending from 2 + to 9 + are seen with no rotation-alignment. The purity of these bands and their persistence to such high spin establish them as an independent collective mode which is best described as a gamma-type vibration band in a deformed nucleus. In addition to all of the above bands, new bands are seen in 76 Kr and 74 Se. The nature of these bands is not presently known. 56 references

Multi-particle excitations in the superdeformed {sup 149}Gd nucleus

Energy Technology Data Exchange (ETDEWEB)

Flibotte, S. [Strasbourg-1 Univ., 67 (France). Centre de Recherches Nucleaires]|[Department of Physics and Astronomy, McMaster, University, Hamilton ON L8S 4M1 (Canada)]|[AECL Research, Chalk River Laboratories, Chalk River ON K0J 1J0 (Canada); Hackman, G. [Department of Physics and Astronomy, McMaster, University, Hamilton ON L8S 4M1 (Canada); Ragnarsson, I. [Department of Mathematical Physics, Lund institute of Technology, Box 118 S-221, Lund (Sweden); Theisen, C. [Strasbourg-1 Univ., 67 (France). Centre de Recherches Nucleaires; Andrews, H.R. [AECL Research, Chalk River Laboratories, Chalk River ON K0J 1J0 (Canada); Ball, G.C. [AECL Research, Chalk River Laboratories, Chalk River ON K0J 1J0 (Canada); Beausang, C.W. [Oliver Lodge Laboratory, University of Liverpool, Liverpool L69 3BX (United Kingdom); Beck, F.A. [Strasbourg-1 Univ., 67 (France). Centre de Recherches Nucleaires; Belier, G. [Strasbourg-1 Univ., 67 (France). Centre de Recherches Nucleaires; Bentley, M.A. [Staffordshire University, Stoke on Trent (United Kingdom); Byrski, T. [Strasbourg-1 Univ., 67 (France). Centre de Recherches Nucleaires; Curien, D. [Strasbourg-1 Univ., 67 (France). Centre de Recherches Nucleaires; France, G. de [Strasbourg-1 Univ., 67 (France). Centre de Recherches Nucleaires; Disdier, D. [Strasbourg-1 Univ., 67 (France). Centre de Recherches Nucleaires; Duchene, G. [Strasbourg-1 Univ., 67 (France). Centre de Recherches Nucleaires; Haas, B. [Strasbourg-1 Univ., 67 (France). Centre de Recherches Nucleaires; Haslip, D.S. [Department of Physics and Astronomy, McMaster, University, Hamilton ON L8S 4M1 (Canada); Janzen, V.P. [Department of Physics and Astronomy, McMaster, University, Hamilton ON L8S 4M1 (Canada)]|[AECL Research, Chalk River Laboratories, Chalk River ON K0J 1J0 (Canada); Jones, P.M. [Oliver Lodge Laboratory, University of Liverpool, Liverpool L69 3BX (United Kingdom); Kharraja, B.

1995-02-20

Six rotational bands built on superdeformed intrinsic configurations have been observed in the {sup 149}Gd nucleus with the Eurogam spectrometer. Orbital configuration assignments have been suggested on the basis of their effective alignments calculated with the Nilsson-Strutinsky cranking model. Most of the excited bands have identical partners in neighboring nuclei including one case differing by four mass units. Measurements of feeding patterns indicate that the {sup 149}Gd yrast superdeformed band is fed over a wider range of angular momentum than other yrast superdeformed bands in this mass region whereas weaker excited bands in the same nucleus are populated in narrower spin windows. ((orig.))

Band structure in {sup 83}Rb from lifetime measurements

Energy Technology Data Exchange (ETDEWEB)

Ganguly, S. [Saha Institute of Nuclear Physics, Kolkata 700064 (India); Banerjee, P. [Saha Institute of Nuclear Physics, Kolkata 700064 (India)]. E-mail: polash.banerjee@saha.ac.in; Ray, I. [Saha Institute of Nuclear Physics, Kolkata 700064 (India); Kshetri, R. [Saha Institute of Nuclear Physics, Kolkata 700064 (India); Bhattacharya, S. [Saha Institute of Nuclear Physics, Kolkata 700064 (India); Saha-Sarkar, M. [Saha Institute of Nuclear Physics, Kolkata 700064 (India); Goswami, A. [Saha Institute of Nuclear Physics, Kolkata 700064 (India); Muralithar, S. [Nuclear Science Centre, Post Box 10502, New Delhi 110067 (India); Singh, R.P. [Nuclear Science Centre, Post Box 10502, New Delhi 110067 (India); Kumar, R. [Nuclear Science Centre, Post Box 10502, New Delhi 110067 (India); Bhowmik, R.K. [Nuclear Science Centre, Post Box 10502, New Delhi 110067 (India)

2006-03-20

Excited states of {sup 83}Rb, populated in the {sup 76}Ge({sup 11}B,-bar 4n{gamma}) reaction at a beam energy of 50 MeV, have been studied. The unfavoured signature partner ({alpha}=-1/2) of the {pi}g{sub 9/2} yrast band is proposed up to an excitation energy of 6669.4 keV and spin (31/2{sup +}). Lifetimes have been estimated for three states belonging to the favoured {alpha}=+1/2 band. The B(E2) values deduced from these lifetimes indicate a moderate quadrupole deformation of {beta}{sub 2}=0.20. Theoretical calculations within the framework of the particle-rotor-model suggest that low energy states before the onset of the {nu}g{sub 9/2} alignment at a rotational frequency of {approx}0.5 MeV are prolate while those above this frequency have an oblate shape. The excited {delta}I=1 band has been extended up to 5422.7 keV and spin 25/2{sup -}. The B(M1) rates derived from the measured lifetimes decrease with spin. The results are in general agreement with an earlier TAC calculation, suggesting the interpretation of these states as arising from magnetic rotation.

Identification of rotating and vibrating tetrahedrons in the heavy nucleus {sup 208}Pb

Energy Technology Data Exchange (ETDEWEB)

Heusler, A.

2017-11-15

Ten known states in the heavy nucleus {sup 208}Pb at 2.6 < E{sub x} < 7.9 MeV are described by rotating and vibrating tetrahedrons. The 3{sup -} and 4{sup +} yrast states are the first members of the rotational band. A 2{sup ±} doublet state with the 2{sup +} yrast state as one member and the newly recognized 2{sup -} yrast state as the other member, the 1{sup -} yrast state, and the third 0{sup +} state are the heads of the three elementary tetrahedral rotating and vibrating bands. The newly recognized state at E{sub x} = 4142 keV was assigned spin 2 in 1975 and is suggested to have negative parity by the absent {sup 208}Pb(α, α{sup '}) excitation. Four more states at 5.7 < E{sub x} < 7.9 MeV are identified as the next members of the three elementary tetrahedral rotating and vibrating bands. The ambiguous spin assignment to the state at E{sub x} = 7020 keV is settled with 3{sup -}, the state at E{sub x} = 7137 keV is assigned 4{sup -}. (orig.)

Recent developments in high-spin calculations in atomic nuclei

International Nuclear Information System (INIS)

Szymanski, Z.

1980-01-01

A brief introduction to the recent achievements in the high-spin domain in nuclear physics is given. Results of the calculations in highly developed rotational bands in deformed nuclei, as well as the calculations in the structure of the yrast isomers are presented. The calculations fail in two aspects: local minima in the yrast line are not confirmed experimentally, the overall slope of the yrast line in 152 Dy is considerably overestimated. The calculations of the yrast line with new Woods-Saxon parameters are now in progress. The parameters are chosen to reproduce the large gap in the levels at proton number Z=64. (M.H.)

Pseudomagic nuclei

International Nuclear Information System (INIS)

Scharff-Goldhaber, G.

1979-01-01

It was shown previously that, below a critical angular momentum, yrast bands of nonmagic nuclei are well described by the two-parameter variable moment of inertia model. Some striking exceptions to this rule are found in nuclei which have the same mass number as doubly magic nuclei but possess either one (or two) proton pairs beyond a magic number and one (or two) neutron hole pairs, or vice versa. Yrast bands in these pseudomagic nuclei resemble those in magic nuclei. 17 references

High-spin yrast states in the 206Po, 208Po, 209At and 210At nuclei

International Nuclear Information System (INIS)

Rahkonen, Vesa.

1980-08-01

High-spin yrast states in the 206 , 208 Po and 209 , 210 At nuclei have been studied with methods of in-beam γ-ray and conversion-electron spectroscopy and with the (α,3n), (α,4n), (p,2n) and ( 3 He,3n) reactions. Several new high-spin states have been identified up to angular momenta of 18-19 h/2π in these nuclei except in 206 Po where the highest spin was (13 - ). In the course of this work two new isomers with half-lives of 15+-3 ns and 4+-2 μs have been observed at 1689 and 4028 keV in 210 At, which have been interpreted as (10 - ) and 19 + states. The previously-known half-lives of 29+-2 and 680+-75 ns have been established for the three-proton states of Jsup(π)=21/2 - and 29/2 + at 1428 and 2429 keV in 209 At, respectively. A half-life of 1.0+-0.2 μs was measured for the 9 - isomer in 206 Po. Shell-model calculations based on the use of the empirical single- and two-particle interaction energies or of the experimental excitation energies belonging to the relevant one-, two- and three-particle states, have been carried out for these 4-6 particle nuclei. Most of the medium-spin yrast states in 206 Po, 208 Po and 209 At have been successfully described assuming the core for these nuclei being 204 Pb or 206 Pb rather than 208 Pb, and including an extra core polarization interaction described by the P 2 force. (author)

Experimental determination of the lifetimes and parities of the Yrast states of 60Ni. Study of shape

International Nuclear Information System (INIS)

Moyat, M.-G.

1978-01-01

The two methods used to measure the lifetimes of the Yrast states of 60 Ni are described: the Doppler attenuation method (line deformation) and the recoil range method. The lifetimes obtained for the levels at 2505, 4262, 5345 and 6807 keV are given, together with the transition probabilities inferred. The parities of the 60 Ni high-spin levels measured by the linear polarization method are also given. Finally the recent theoretical approaches relating to the shapes of the nuclei are outlined: K. Kuman's deformed quasi-particle model and the interaction boson approximation of A. Arima and F. Iachello [fr

Rotational structure of odd-proton {sup 103,105,107,109,111}Tc isotopes

Energy Technology Data Exchange (ETDEWEB)

Kumar, Amit [University of Jammu, Department of Physics and Electronics, Jammu (India); Government of J and K, Department of Higher Education, Jammu (India); Singh, Dhanvir; Bharti, Arun [University of Jammu, Department of Physics and Electronics, Jammu (India); Singh, Suram; Bhat, G.H. [Government of J and K, Department of Higher Education, Jammu (India); Sheikh, J.A. [University of Kashmir, Department of Physics, Srinagar (India)

2017-10-15

A systematic study of the yrast band structure for the neutron-rich odd-mass {sup 103-111}Tc nuclei is carried out using Projected Shell Model. The rotational band structure has been studied up to a maximum spin of 59/2{sup +}. Excellent agreement with available experimental data for all isotopes is obtained. The energy spectra and electromagnetic transition strengths in terms of the configuration mixing of the angular-momentum projected multi-quasiparticle states are studied in detail. Signature splitting in the yrast rotational band is well described in the perspective of nuclear structure physics. The back-bending phenomenon is also well described for these nuclei in the present work. (orig.)

RDDS lifetime measurements of low-lying superdeformed states in {sup 194}Hg

Energy Technology Data Exchange (ETDEWEB)

Kuehn, R.; Dewald, A.; Kruecken, R. [Universitaet Koeln (Germany)] [and others

1996-12-31

The lifetimes of three low-lying states in the superdeformed (SD) yrast band of {sup 194}Hg were measured by the recoil-distance Doppler-shift method. The deduced transition quadrupole moments, Q{sub t}, equal those extracted from a DSAM measurement for the high-lying states of the band corroborate the assumption that the decay out of SD bands does not strongly affect the structure of the corresponding states. By a simple mixing-model the decay can be described assuming a very small admixture of normal-deformed (ND) states to the decaying SD states. The deduced ND mixing amplitudes for the yrast SD bands in {sup 192,194}Hg and {sup 194}Pb are presented along with average transition quadrupole moments for the lower parts of the excited SD bands.

Study of yrast band in 155Tm

International Nuclear Information System (INIS)

Raut, R.; Bhowal, S.; Ganguly, S.; Kshetri, R.; Banerjee, P.; Bhattacharya, S.; Bhowmik, R.K.; Dasmahapatra, B.; Gangopadhyay, G.; Mukherjee, A.; Muralithar, S.; SahaSarkar, M.; Singh, R.P.; Goswami, A.

2007-01-01

The nucleus 155 Tm has been studied by a detailed in-beam gamma spectroscopy following the reaction 144 Sm( 14 N, 3n) 155 Tm, at a beam energy, E lab =70MeV, using a Compton suppressed gamma detector array. More than 25 new gamma transitions have been placed in the proposed scheme and the latter has been extended upto a spin-parity of (51/2 - ) at an excitation energy ∼ 6 MeV

Transition probabilities in neutron-rich Se,8280 and the role of the ν g9 /2 orbital

Science.gov (United States)

Litzinger, J.; Blazhev, A.; Dewald, A.; Didierjean, F.; Duchêne, G.; Fransen, C.; Lozeva, R.; Verney, D.; de Angelis, G.; Bazzacco, D.; Birkenbach, B.; Bottoni, S.; Bracco, A.; Braunroth, T.; Cederwall, B.; Corradi, L.; Crespi, F. C. L.; Désesquelles, P.; Eberth, J.; Ellinger, E.; Farnea, E.; Fioretto, E.; Gernhäuser, R.; Goasduff, A.; Görgen, A.; Gottardo, A.; Grebosz, J.; Hackstein, M.; Hess, H.; Ibrahim, F.; Jolie, J.; Jungclaus, A.; Kolos, K.; Korten, W.; Leoni, S.; Lunardi, S.; Maj, A.; Menegazzo, R.; Mengoni, D.; Michelagnoli, C.; Mijatovic, T.; Million, B.; Möller, O.; Modamio, V.; Montagnoli, G.; Montanari, D.; Morales, A. I.; Napoli, D. R.; Niikura, M.; Pietralla, N.; Pollarolo, G.; Pullia, A.; Quintana, B.; Recchia, F.; Reiter, P.; Rosso, D.; Sahin, E.; Salsac, M. D.; Scarlassara, F.; Söderström, P.-A.; Stefanini, A. M.; Stezowski, O.; Szilner, S.; Theisen, Ch.; Valiente-Dobón, J. J.; Vandone, V.; Vogt, A.

2018-04-01

Transition probabilities of intermediate-spin yrast and non-yrast excitations in Se,8280 were investigated in a recoil distance Doppler-shift (RDDS) experiment performed at the Istituto Nazionale di Fisica Nucleare, Laboratori Nazionali di Legnaro. The Cologne Plunger device for deep inelastic scattering was used for the RDDS technique and was combined with the AGATA Demonstrator array for the γ -ray detection and coupled to the PRISMA magnetic spectrometer for an event-by-event particle identification. In 80Se, the level lifetimes of the yrast (61+) and (81+) states and of a non-yrast band feeding the yrast 41+ state are determined. A spin and parity assignment of the head of this sideband is discussed based on the experimental results and supported by large-scale shell-model calculations. In 82Se, the level lifetimes of the yrast 61+ state and the yrare 42+ state and lifetime limits of the yrast (101+) state and of the 51- state are determined. Although the experimental results contain large uncertainties, they are interpreted with care in terms of large-scale shell-model calculations using the effective interactions JUN45 and jj44b. The excited states' wave functions are investigated and discussed with respect to the role of the neutron g9 /2 orbital.

High-spin states in 109,111Cd and 107Pd

International Nuclear Information System (INIS)

Juutinen, S.; Simecek, P.; Fahlander, C.; Julin, R.; Kumpulainen, J.; Lampinen, A.; Loennroth, T.; Maj, A.; Mitarai, S.; Mueller, D.; Nyberg, J.; Piiparinen, M.; Sugawara, M.; Thorslund, I.; Toermaenen, S.; Virtanen, A.

1994-01-01

The nuclei 107 Pd, 109 Cd and 111 Cd have been studied using proton-, 13 C- and 18 O-induced reactions. Fourteen bands were observed in 109 Cd and the yrast cascade was extended to I π =(51/2 - ). Two of the bands consist of ΔI=1 transitions. In 107 Pd the present level scheme includes three bands, while in 111 Cd with much lower reaction cross section only the yrast cascade was observed. Experimental routhians and aligned angular momenta as well as B(M1)/B(E2) ratios were extracted and used, together with the predictions of TRS and CSM calculations, to assign quasiparticle configurations to the bands. In several bands, the neutron h 11/2 alignment was observed and the alignment frequency was found to be sensitive to the deformation and to the neutron number. Shape change effects are discussed. ((orig.))

Study of yrast band in {sup 155}Tm

Energy Technology Data Exchange (ETDEWEB)

Raut, R. [Nuclear and Atomic Physics Division, Saha Institute of Nuclear Physics, 1/AF Bidhannagar, Kolkata-700064 (India); Bhowal, S. [Department of Physics, Surendranath College (Evening), M.G. road, Kolkata-700009 (India); Ganguly, S.; Kshetri, R.; Banerjee, P.; Bhattacharya, S. [Nuclear and Atomic Physics Division, Saha Institute of Nuclear Physics, 1/AF Bidhannagar, Kolkata-700064 (India); Bhowmik, R.K. [Inter University Accelerator Center, Aruna Asaf Ali Marg, New Delhi (India); Dasmahapatra, B. [Nuclear and Atomic Physics Division, Saha Institute of Nuclear Physics, 1/AF Bidhannagar, Kolkata-700064 (India); Gangopadhyay, G. [Department of Physics, University College of Science Technology, 92, A.P.C. road, Kolkata-700073 (India); Mukherjee, A. [Nuclear and Atomic Physics Division, Saha Institute of Nuclear Physics, 1/AF Bidhannagar, Kolkata-700064 (India); Muralithar, S. [Inter University Accelerator Center, Aruna Asaf Ali Marg, New Delhi (India); SahaSarkar, M. [Nuclear and Atomic Physics Division, Saha Institute of Nuclear Physics, 1/AF Bidhannagar, Kolkata-700064 (India); Singh, R.P. [Inter University Accelerator Center, Aruna Asaf Ali Marg, New Delhi (India); Goswami, A. [Nuclear and Atomic Physics Division, Saha Institute of Nuclear Physics, 1/AF Bidhannagar, Kolkata-700064 (India)], E-mail: asimananda.goswami@saha.ac.in

2007-10-01

The nucleus {sup 155}Tm has been studied by a detailed in-beam gamma spectroscopy following the reaction {sup 144}Sm({sup 14}N, 3n){sup 155}Tm, at a beam energy, E{sub lab}=70MeV, using a Compton suppressed gamma detector array. More than 25 new gamma transitions have been placed in the proposed scheme and the latter has been extended upto a spin-parity of (51/2{sup -}) at an excitation energy {approx} 6 MeV.

High-spin structure of yrast-band in Kr

Indian Academy of Sciences (India)

320(70) fs was obtained from the present data at 75. ° for the 24. + level. Zeigler's stopping powers have been used for the calculation of the energy loss parameters of the recoiling nuclei. The experimental data along with the theoretical fits for the lifetimes measured can be seen in figure 1. The present lifetime values up to ...

Gamma spectroscopic studies of the neutron-deficient g-g nucleus 74Kr by means of a neutron multiplicity measurement technique

International Nuclear Information System (INIS)

Roth, J.

1981-01-01

The g-g nucleus 74 Kr was studied by means of the reaction 58 Ni ( 19 F, p2n#betta#) 74 Kr. In order to make gamma spectroscopic studies at neutron deficient nuclei like 74 Kr a neutron multiplicity measurement technique was developed. Beside #betta# single spectra, #betta# excitation functions, #betta#-#betta# coincidences, #betta# angular distributions, and lifetime measurements by means of this technique all measurements in coincidence with up to two neutrons were taken up. From these measurement data an extended term scheme with 17 newly found excited states could be extracted. To all levels spins and parities could be assigned. From the four energetically lowest levels of the yrast cascade the mean lifetimes could be determined. A double backbending in the sequence of the yrast cascade was interpreted as crossing of the g 9/2 bands. The irregularities in the lower part of the yrast band correspond to the shape consistence picture. The results were considered in connection with the systematics of the even krypton isotopes and compared with a two-quasiparticle-plas-rotor model calculation. (HSI)

Dynamical moments of inertia for superdeformed nuclei

International Nuclear Information System (INIS)

Obikhod, T.V.

1995-01-01

The method of quantum groups has been applied for calculation the dynamical moments of inertia for the yrast superdeformed bands in 194 Hg and 192 Hg as well as to calculation of the dynamical moments of inertia of superdeformed bands in 150 Gd and 148 Gd

Nuclear wobbling motion and properties of E-2 transitions

Energy Technology Data Exchange (ETDEWEB)

Shimizu, Y R [Kyushu Univ., Fukuoka (Japan). Dept. of Physics; Matsuzaki, M [Fukuoka Univ. (Japan)

1992-08-01

The nuclear wobbling motion associated with the static triaxial deformation are discussed based on a microscopic theory. Properties of the E2-transitions between the one-phonon wobbling band and the yrast (vacuum) band are studied and their characteristic features are suggested. (author). 11 refs., 3 figs.

Observation and empirical shell-model study of new yrast excited states in the nucleus sup 1 sup 4 sup 2 Ce

CERN Document Server

Liu Zhong; Guo Ying Xiang; Zhou Xiao Hong; Lei Xiang Guo; LiuMinLiang; Luo Wan Ju; He Jian Jun; Zheng Yong; Pan Qiang Yan; Gan Zai Guo; Luo Yi Xiao; Hayakawa, T; Oshima, M; Toh, Y; Shizima, T; Hatsukawa, Y; Osa, A; Ishii, T; Sugawara, M

2002-01-01

Excited states of sup 1 sup 4 sup 2 Ce, populated in deep inelastic reactions of sup 8 sup 2 Se projectiles bombarding sup 1 sup 3 sup 9 La target, have been studied to medium spins using in-beam gamma spectroscopy techniques. Three new levels have been identified at 2625, 2995 and 3834 keV, and assigned as 8 sup + , 9 sup ( sup - sup ) and 11 sup ( sup - sup ) , respectively, based on the analysis of the properties of gamma transitions. These new yrast states follow well the level systematics of N 84 isotones. Their structures have been discussed with the help of empirical shell-model calculations

Lifetimes of the low spin states in the superdeformed band of {sup 192}Hg

Energy Technology Data Exchange (ETDEWEB)

Lee, I Y; Baktash, C; Cullen, D; Garrett, J D; Johnson, N R; McGowan, F K; Winchell, D F [Oak Ridge National Lab., TN (United States); Yu, C H [Tennessee Univ., Knoxville, TN (United States)

1992-08-01

Superdeformed (SD) states with a 2:1 axis ratio have been observed in nuclei in the A = 150, 190, and the actinide regions. These states depopulate into normally deformed (ND) states by gamma decay, but so far the linking transitions have not been observed and the depopulation mechanism is not fully understood. Nuclei in different mass regions decay out at states with different spin (I), excitation energy above the ND yrast line (U) and lifetime {tau}. This variation is due to differences in the nuclear properties such as the barrier penetration probability, the level densities and the gamma transition strength of SD and ND states. One important factor is the competition between the collective E2 decay along the SD band and the statistical decay to the ND states. These transition rates, or the partial lifetimes, can be determined if the lifetime and the intensity of the gamma rays depopulating the SD states are known. (author). 4 refs., 2 tabs., 2 figs.

Lifetime measurements in shape transition nucleus 188Pt

Science.gov (United States)

Rohilla, Aman; Gupta, C. K.; Singh, R. P.; Muralithar, S.; Chakraborty, S.; Sharma, H. P.; Kumar, A.; Govil, I. M.; Biswas, D. C.; Chamoli, S. K.

2017-04-01

Nuclear level lifetimes of high spin states in yrast and non-yrast bands of 188Pt nucleus have been measured using recoil distance plunger setup present at IUAC, Delhi. In the experiment nuclear states of interest were populated via 174Yb(18O,4 n)188Pt reaction at a beam energy of 79MeV provided by 15 UD Pelletron accelerator. The extracted B(E2\\downarrow) values show an initial rise up to 4+ state and then a nearly constant behavior with spin along yrast band, indicating change of nuclear structure in 188Pt at low spins. The good agreement between experimental and TPSM model B(E2\\downarrow) values up to 4^+ state suggests an increase in axial deformation of the nucleus. The average absolute β2 = 0.20 (3) obtained from measured B(E2\\downarrow) values matches well the values predicted by CHFB and IBM calculations for oblate ( β2 ˜ -0.19) and prolate (β2 ˜ 0.22) shapes. As the lifetime measurements do not yield the sign of β2, no definite conclusion can be drawn on the prolate or oblate collectivity of 188Pt on the basis of present measurements.

The importance of triaxial shapes in spin aligned configurations in the A = 170-180 mass region

International Nuclear Information System (INIS)

Bengtsson, R.

1990-01-01

Deformations determined from total routhian surfaces (TRS) for the yrast states of even-even isotopes of W, Os, and Pt are presented. The calculated deformations imply a number of specific features for the yrast line, resulting from deformation changes and the alignment of specific pairs of quasiparticles. The triaxial shapes predicted from the TRS are important for determining the character of the aligning particles as well as for making a correct interpretation of the strength of the interaction between crossing bands and the bandcrossing frequencies. 19 refs., 9 figs

Exotic superdeformed structure in A∼190 nuclei observed using Eurogam2

International Nuclear Information System (INIS)

Wilson, A.N.; Timar, J.; Bergstroem, M.; Paul, E.S.; Bouneau, S.; Azaiez, F.; Korichi, A.; Nakatsukasa, T.

1995-01-01

Dipole transitions between superdeformed rotational bands are only very rarely observed due to the competition from the very strong in-band E2 decays. We have carried out two experiments with the EUROGAM2 γ-ray spectrometer, situated at the Vivitron tandem accelerator at CRN Strasbourg, in September and October 1994. In the first experiment we observe M1 dipole transitions between the signature partner yrast superdeformed bands in 193 Tl. This measurement gives a mean value of (g K -g R ) K/Q o = 0.135 ± 0.010 μ N /eb identifying the bands as belonging to the (642)5/2 single particle orbital. We also observe 5 additional new superdeformed bands in 193 Tl, whose structures are discussed. In the second experiment we observe three transitions, at 911, 865 and 831 keV, which link an excited superdeformed band in 190 Hg to the yrast superdeformed band. The data suggest that these are stretched dipole transitions with E1 multipolarity and strengths of about 10 -3 Wu. This is the first observation of a collective vibration of the superdeformed mean field. We also observe two new superdeformed bands in 190 Hg. (authors). 39 refs., 11 figs., 3 tabs

Unsafe Coulomb excitation of $^{240-244}Pu$

CERN Document Server

Wiedenhöver, I; Hackman, L; Ahmad, I; Greene, J P; Amro, H; Carpenter, M P; Nisius, D T; Reiter, P; Lauritsen, T; Lister, C J; Khoo, T L; Siem, S; Cizewski, J A; Seweryniak, D; Uusitalo, J; Macchiavelli, A O; Chowdhury, P; Seabury, E H; Cline, D; Wu, C Y

1999-01-01

The high spin states of /sup 240/Pu and /sup 244/Pu have been investigated with GAMMASPHERE at ATLAS, using Coulomb excitation with a /sup 208/Pb beam at energies above the Coulomb barrier. Data on a transfer channel leading to /sup 242/Pu were obtained as well. In the case of /sup 244/Pu, the yrast band was extended to 34h(cross), revealing the completed pi i/sub 13/2/ alignment, a "first" for actinide nuclei. The yrast sequence of /sup 242/Pu was also extended to higher spin and a similar backbend was delineated. In contrast, while the ground state band of /sup 240/Pu was measured up to the highest rotational frequencies ever reported in the actinide region (~300 keV), no sign of particle alignment was observed. (11 refs).

Band termination in the N=Z nucleus 44Ti

International Nuclear Information System (INIS)

Ur, C.A.; Lenzi, S.M.; Martinez-Pinedo, G.

1998-01-01

Nuclei in the vicinity of the middle of the 1f 7/2 shell show strong prolate deformation at low spins resulting in rotational-like band structures. With increasing angular momentum the structure of these nuclei evolves through triaxial and spherical shapes. Recently, band terminating states corresponding to fully aligned configurations of valence nucleons in the f 7/2 shell have been reported. Further increase of the angular momentum can be achieved by particle excitations on the higher shell. This will result in high energy γ-ray transitions as it was observed in 50 Cr. We have investigated the structure of 44 Ti up to the band termination. Excited states in 44 Ti have been populated via the 28 Si + 24 Mg at 110 MeV beam energy. The target consisted of ∼0.5 mg/cm 2 of 24 Mg deposited on a gold backing. Gamma-rays were detected with the GASP multidetector array composed by 40 HPGe Compton-suppressed detectors and the inner ball built of 80 BGO detectors. The preliminary level scheme of 44 Ti, as determined in our work, is presented. This nucleus has 2 valence protons and 2 valence neutrons filling the f 7/2 shell. The band terminating state corresponding to their total alignment is the 12 + state. Several γ-rays transitions above this state have been identified. Also, we have identified two negative parity bands strongly connected to the yrast positive parity structure. Such structures have also been observed in other two even-even N=Z nuclei in the f 7/2 shell, namely, 44 Cr and 52 Fe, but they were less populated. The structure of 44 Ti is also interesting from the point of view of the cross-conjugate symmetry. Comparing the level structure of 44 Ti and the one of its cross-conjugate nucleus at the other end of the shell, 52 Fe, it can be noticed that up to spin 10ℎ their structure is very similar, but in 44 Ti the band terminating state 12 + is not below the 10 + state as in the case of 52 Fe. This was related to a reminiscent degree of collectivity in the

High-spin rotational states in {sup 179}Os

Energy Technology Data Exchange (ETDEWEB)

Burde, J [Lawrence Berkeley Lab., CA (United States); [Hebrew Univ., Jerusalem (Israel). Racah Inst. of Physics; Deleplanque, M A; Diamond, R M; Macchiavelli, A O; Stephens, F S; Beausang, C W [Lawrence Berkeley Lab., CA (United States)

1992-08-01

The rotational bands of the osmium isotopes display very interesting properties that vary with the neutron number. On the one hand the yrast bands of {sup 182,184,186}Os display a sudden and rather strong gain in aligned angular momentum,, whereas the lighter osmium nuclei such as {sup 176,178,180}Os show a more gradual increase of alignment characteristic of strongly interacting bands. In addition, an unusual rotational band has been found in {sup 178}Os. It consists of seven regularly spaced transitions about 36 keV apart which correspond closely to the spacing of the superdeformed band in {sup 152}Dy after an A{sup 5/3} normalization. this band populates the yrast band directly, and the moment of inertia J{sup (1)} is found to be much smaller than J{sup (2)}. The most likely interpretation of this is a band with large deformation which is undergoing systematic changes in deformation, pairing and/or alignment. This latter finding in particular motivated us to carry out research on the higher spin states in {sup 179}Os. Dracoulis et al. have published their results on 5 rotational bands in {sup 179}Os. In the present work we found six new bands and extended appreciably the spin limits in the other five. (author). 5 refs., 3 figs.

Pramana – Journal of Physics | Indian Academy of Sciences

Indian Academy of Sciences (India)

The results show the existence of energy levels with high quantum numbers lying close to the yrast line in both the nuclei. Such high states should exhibit isomeric characteristics due to the -selection rules for the -decays. Moreover, in 78Kr a new band with = 20–30 lying below the observed ground band is ...

Fulltext PDF

Indian Academy of Sciences (India)

719. Bharti Arun. Structure of negative parity yrast bands ... netism of the linear chain system β-. Cu2− ... chronization in chaotic systems. 919. Dwivedi ... Experimental analysis of current conduc- .... Design studies of a high-current radiofre-.

Shape coexistence of light, even A mercury isotopes

International Nuclear Information System (INIS)

Cole, J.D.

1978-01-01

The results of the studies of the decay of thallium isotopes establish the coexistence and crossing of two bands in the mercury isotopes. The two bands are built on states of different deformation. The band built upon the ground state has an associated small negative β value (oblate shape) while the second band has a large positive β value (prolate shape). The band heads for the deformed bands in the 184 186 188 Hg isotopes are established as 0 + levels at 375.2, 523.8, and 824.5 keV respectively. A comparison between the experimental results and the predictions of calculations based upon the coexistence of two different nuclear deformations has been made. The presence of two different deformations as described by two minima in the nuclear potential energy curve is termed ''shape coexistence.'' The good agreement of the calculations with the experimental results adds further support to the coexistence interpretation. The coexistence and crossing of two bands of different deformation explains the unusual behavior of the yrast level spacing that is referred to as 'backbending' when discussing moment of inertia versus rotational frequency plots based on the yrast levels. The studies of the 186 188 Pt levels have established the lower members of the ground state band and of a rotation-alignment band. The experimental results confirm the rotation-alignment explanation of backbending in the platinum cases discussed. (Auth.)

Lifetime in 181Ir and 187Au: enhanced deformation of the πi 13/2 intruder orbital

International Nuclear Information System (INIS)

Walpe, J.C.; Garg, U.; Naguleswaran, S.; Ren, Q.W.

1995-01-01

Lifetimes have been measured in the πh 9/2 (yrast) and πi 13/2 (excited) bands in the nuclei 181 Ir and 187 Au using the Recoil Distance Method (RDM). The results clearly indicate that the πi 13/2 band exhibits an increased deformation over the πh 9/2 band, in keeping with the premise that the delayed crossing in this band is due to enhanced quadrupole deformation. (author). 3 refs, 1 fig, 2 tab

Projected shell model study of neutron- deficient 122Ce

Indian Academy of Sciences (India)

Projected shell model; band diagram; yrast energies; electromagnetic quan- ... signed to 122Ce by detecting γ-rays in coincidence with evaporated charged particles .... 0.75 from the free nucleon values to account for the core-polarization and ...

Superdeformation studies in the odd-odd nucleus {sup 192}Tl

Energy Technology Data Exchange (ETDEWEB)

Fischer, S.; Carpenter, M.P.; Janssens, R.V.F. [and others

1995-08-01

The study of yrast and near-yrast structures of odd-odd nuclei to high spins is somewhat limited due to the complexity of the spectra resulting from the many proton-neutron couplings near the Fermi surface. In superdeformed nuclei, the number of available protons and neutrons near the Fermi surface is somewhat limited due to the presence of large-shell gaps which stabilize the nuclear shape. A relatively small number of available neutron and proton configurations can lead to fragmentation of the SD intensity into a number of different bands. Two good examples of this phenomenon were found in {sup 192}Tl and {sup 194}Tl where the presence of six superdeformed bands were reported in both nuclei. We reexamined {sup 192}Tl at Gammasphere using the {sup 160}Gd({sup 37}Cl,5n) reaction at 178 MeV to populate states in the superdeformed well of this nucleus. While our previous study on {sup 192}Tl at ATLAS was very successful, a number of questions remained which formed the basis of our objectives in this experiment: obtain better {gamma}-ray energies for the known transitions and identify higher spin members in each band; determine how the bands feed the known yrast states in {sup 192}Tl as well as determine the complete spectrum in coincidence with the SD bands; look for M1 transitions connecting proposed signature partners; and attempt to identify other excitations in the superdeformed well. Analysis is underway and four of the six bands were confirmed. The reasons that two of the reported bands were not observed in this latest work is still under investigation. As of this time, no other superdeformed bands were identified in the data. Two of the confirmed SD bands have a constant moment of inertia and show indications of cross-talk between each other. This observation is not unexpected since the calculated M1 rates for the proposed configuration of the band, {pi}{sub 13/2} x {upsilon}j{sub 15/2}, indicate that M1 transitions linking the two SD bands should be observed.

Investigation of the structure of core-coupled odd-proton copper nuclei in fpg valence space using the projected shell model

Energy Technology Data Exchange (ETDEWEB)

Gupta, Anuradha; Singh, Suram; Bharti, Arun [University of Jammu, Department of Physics and Electronics, Jammu (India); Khosa, S.K. [Central University of Jammu, Department of Physics and Astronomical Sciences, Jammu (India); Bhat, G.H.; Sheikh, J.A. [University of Kashmir, Department of Physics, Srinagar (India)

2017-01-15

By employing a systematically parametrized Hamiltonian and the best fit of the various input parameters, high-spin yrast energy states for an isotopic chain of odd mass {sup 59-69}Cu nuclei have been investigated by using a novel computational quantum mechanical framework-projected shell model. Comparison of calculations and experiments yields good agreement. The present study of various intriguing nuclear structure properties along the yrast lines in these odd proton isotopes reflects some interesting informative nuclear physics results. The calculations successfully describe the formation of the yrast level structures from multi-quasi-particle configurations based on πf x νg bands for {sup 59-69}Cu isotopes. The present calculations indicate the evolution of the nuclear structure near the magic nuclei, Ni, and also provide an indication of coexistence of both, collective as well as single-particle, levels for {sup 69}Cu nucleus at N=40. (orig.)

Cold transfer between deformed, Coulomb excited nuclei

International Nuclear Information System (INIS)

Bauer, H.

1998-01-01

The scattering system 162 Dy → 116 Sn has been examined at energies in the vicinity of the Coulomb barrier using the Heidelberg-Darmstadt Crystal Ball spectrometer combined with 5 Germanium-CLUSTER detectors. In order to study pairing correlations as a function of angular momentum cold events were selected in the 2n stripping channel by identifying and suppressing the dominant hot part of the transfer with the Crystal Ball. The CLUSTER detectors with their high γ-efficiency were used to identify the transfer channel and to resolve individual final states. Cross sections for the population of individual yrast states in a cold transfer reaction have been measured for the first time indicating the strong influence of higher transfer multipolarities. At small surface distances Coulomb-nuclear interferences were found to be responsible for the stronger decline of the population of higher yrast states in the transfer channel as compared to the Coulex channel. As a preparatory study for 2n transfer measurements between high spin yrast states in the backbending region of deformed nuclei the Coulomb excitation process in the crossing region of two bands in 162 Dy has been analyzed. The gross properties of the measured population probabilities could be interpreted in a simple band mixing model. (orig.)

Lifetime measurements in shape transition nucleus {sup 188}Pt

Energy Technology Data Exchange (ETDEWEB)

Rohilla, Aman; Gupta, C.K.; Chamoli, S.K. [University of Delhi, Department of Physics and Astrophysics, New Delhi (India); Singh, R.P.; Muralithar, S. [Inter University Accelerator Centre, New Delhi (India); Chakraborty, S.; Sharma, H.P. [Banaras Hindu University, Department of Physics, Varanasi (India); Kumar, A.; Govil, I.M. [Panjab University, Department of Physics, Chandigarh (India); Biswas, D.C. [Bhabha Atomic Research Center, Nuclear Physics Division, Trombay, Mumbai (India)

2017-04-15

Nuclear level lifetimes of high spin states in yrast and non-yrast bands of {sup 188}Pt nucleus have been measured using recoil distance plunger setup present at IUAC, Delhi. In the experiment nuclear states of interest were populated via {sup 174}Yb({sup 18}O,4n){sup 188}Pt reaction at a beam energy of 79MeV provided by 15 UD Pelletron accelerator. The extracted B(E2 ↓) values show an initial rise up to 4{sup +} state and then a nearly constant behavior with spin along yrast band, indicating change of nuclear structure in {sup 188}Pt at low spins. The good agreement between experimental and TPSM model B(E2 ↓) values up to 4{sup +} state suggests an increase in axial deformation of the nucleus. The average absolute β{sub 2} = 0.20 (3) obtained from measured B(E2 ↓) values matches well the values predicted by CHFB and IBM calculations for oblate (β{sub 2} ∝ -0.19) and prolate (β{sub 2} ∝ 0.22) shapes. As the lifetime measurements do not yield the sign of β{sub 2}, no definite conclusion can be drawn on the prolate or oblate collectivity of {sup 188}Pt on the basis of present measurements. (orig.)

Unsafe Coulomb excitation of 240-244Pu

International Nuclear Information System (INIS)

Ahmad, I.; Amro, H.; Carpenter, M. P.; Chowdhury, P.; Cizewski, J.; Cline, D.; Greene, J. P.; Hackman, G.; Janssens, R. V. F.; Khoo, T. L.; Lauritsen, T.; Lister, C. J.; Macchiavelli, A. O.; Nisius, D. T.; Reiter, P.; Seabury, E. H.; Seweryniak, D.; Siem, S.; Uusitalo, J.; Wiedenhoever, I.; Wu, C. Y.

1999-01-01

The high spin states of 240 Pu and 244 Pu have been investigated with GAMMASPHERE at ATLAS, using Coulomb excitation with a 208 Pb beam at energies above the Coulomb barrier. Data on a transfer channel leading to 242 Pu were obtained as well. In the case of 244 Pu, the yrast band was extended to 34h b ar revealing the completed πi 13/2 alignment, a ''first'' for actinide nuclei. The yrast sequence of 242 Pu was also extended to higher spin and a similar backbend was delineated. In contrast, while the ground state band of 240 Pu was measured up to the highest rotational frequencies ever reported in the actinide region (approximately300 keV), no sign of particle alignment was observed. In this case, several observable such as the large B(E1)/B(E2) branching ratios in the negative parity band, and the vanishing energy staggering between the negative and positive parity bands suggest that the strength of octupole correlations increases with rotational frequency. These stronger correlations may well be responsible for delaying or suppressing the πi 13/2 particle alignment

Search for Correlations between Prolate-Shape Collective and Oblate-Shape Non-Collective Nuclear Rotation: High Spin States in 159,160 Yb

International Nuclear Information System (INIS)

Byrski, T.; Beck, F.A.; Sharpey-Schafer, J.F.

1987-01-01

High-spin states of 159,160 Yb have been studied using the escape-suppressed array TESSA 2. Extensions of yrast and lateral bands have been found up to I ∼40. Experimental data suggest strong correlations between maximum alignment configurations of the valence nucleons and related collective states. Theoretical analysis fully supports the idea of prolate-collective vs. oblate-non-collective correlations. Band termination interpretation is discussed

Superdeformation in the mass 190 region

International Nuclear Information System (INIS)

Khoo, T.L.; Lauritsen, T.; Liang, Y.

1992-01-01

The steps in the formation of superdeformed bands are described. The hot compound nucleus cools and is trapped within the superdeformed secondary minimum becoming a cold system executing periodic motion (rotation), before suddenly heating up in the process of decaying to the normal yrast states

Evidence for octupole vibration in the superdeformed well of {sup 190}Hg from eurogam

Energy Technology Data Exchange (ETDEWEB)

Crowell, B.; Carpenter, M.P.; Janssens, R.V.F. [and others

1995-08-01

Gammasphere experiments in 1993-94 brought to light the existence of an excited superdeformed (SD) band in {sup 190}Hg with the unusual property of decaying entirely to the lowest (yrast) SD band over 3-4 transitions, rather than to the normally deformed states as is usually the case in the A {approximately} 150 and A {approximately} 190 regions of superdeformation. Although M1 transitions between signature-partner SD bands were previously observed in {sup 193}Hg, no such mechanism was available to explain the situation in the even-even nucleus {sup 190}Hg, whose yrast SD band has no signature partner. The best explanation appears to lie in long-standing theoretical predictions that the SD minimum in the potential energy surface would be quite soft with respect to octupole vibrations. This would lead to enhanced E1 transitions connecting the one-phonon and zero-phonon states. The data and this interpretation were published. A shortcoming of the Gammasphere experiments was that they did not allow the definitive measurement of the energies of the gamma-ray transitions connecting the two bands, due to the very weak population of the excited band ({approximately}0.05% of the {sup 190}Hg channel) and also partly, we believed, to the angular distributions of the transitions, which were peaked near 90 degrees, where Gammasphere had few detectors.

High spin states in 162Lu

International Nuclear Information System (INIS)

Gupta, S.L.; Pancholi, S.C.; Juneja, P.; Mehta, D.; Kumar, A.; Bhowmik, R.K.; Muralithar, S.; Rodrigues, G.; Singh, R.P.

1997-01-01

An experimental investigation of the odd-odd 162 Lu nucleus, following the 148 Sm( 19 F,5n) reaction at beam energy E lab =112MeV, has been performed through in-beam gamma-ray spectroscopy. It revealed three signature-split bands. The yrast band based on πh 11/2 circle-times νi 13/2 configuration exhibits anomalous signature splitting (the unfavored signature Routhian lying lower than the favored one) whose magnitude Δe ' ∼25keV, is considerably reduced in contrast to sizable normal signature splitting Δe ' ∼125 and 60 keV observed in the yrast πh 11/2 bands of the neighboring odd-A 161,163 Lu nuclei, respectively. The signature inversion in this band occurs at spin ∼20ℎ (frequency=0.37MeV). The second signature-split band, observed above the band crossing associated with the alignment of a pair of i 13/2 quasineutrons, is a band based on the four-quasiparticle [πh 11/2 [523]7/2 - times νh 9/2 [521]3/2 - times(νi 13/2 ) 2 ], i.e., EABA p (B p ), configuration. The third signature-split band is also likely to be a four-quasiparticle band with configuration similar to the second band but involving F quasineutron, i.e., FABA p (B p ). The experimental results are discussed in comparison with the existing data in the neighboring nuclei and in the framework of the cranking shell model. copyright 1997 The American Physical Society

Microscopic study of positive-parity yrast bands of Th isotopes

Indian Academy of Sciences (India)

tor arrays. Thorium is one of the isotopic mass chains that has been studied. The level ... the valence space and np-interaction in SOP orbits plays a crucial role in determining the ..... parameters suggested by Rozmej [37] in the actinide region.

Sphericity in the interacting boson model

International Nuclear Information System (INIS)

Ogata, H.

1977-01-01

The interacting boson model (IBM) of Arima and Iachello is examined. The transition between the rotational and vibrational modes of even-even nuclei is presented as a function of a sphericity parameter, which is determined primarily from yrast band spectra. The backbending feature is reasonably reproduced. (author)

Historical perspective of the relation between IBA and VMI at the magic limit: two opposing views

International Nuclear Information System (INIS)

Scharff-Goldhaber, G.

1984-01-01

The two-parameter rotational VMI equations ascribe the observed abrupt change in yrast bands at the magic limit to a first order phase transition. In contrast, two three-parameter anharmonic vibrator models recently suggested yield two limits of validity, neither of which is supported by data. 15 references

Historical perspective of the relation between IBA and VMI at the magic limit: two opposing views

Energy Technology Data Exchange (ETDEWEB)

Scharff-Goldhaber, G.

1984-01-01

The two-parameter rotational VMI equations ascribe the observed abrupt change in yrast bands at the magic limit to a first order phase transition. In contrast, two three-parameter anharmonic vibrator models recently suggested yield two limits of validity, neither of which is supported by data. 15 references.

Indexes to Volume 74

Indian Academy of Sciences (India)

Bifurcation diagrams in relation to synchronization in chaotic systems. Debabrata Dutta and ... Design studies of a high-current radiofrequency quadrupole for ... 377–390. Structure of negative parity yrast bands in odd mass 125−131Ce nuclei ... Analysis of pulsed wire method for field integral measurements in undulators.

High-Spin States in Odd-Odd N=Z {sup 46}V

Energy Technology Data Exchange (ETDEWEB)

O' Leary, C.D.; Bentley, M.A.; Appelbe, D.E.; Bark, R.A.; Cullen, D.M.; Erturk, S.; Maj. A.; Sheikh, J.A.; Warner, D.D.

1999-12-31

High-spin states up to the F{sub 7/2}-shell band termination at J{pi}=15+ have been observed for the first time in the odd-odd N=Z=23 nucleous {sup 46}V. The new level scheme has two separate structures corresponding to spherical and prolate shapes. A rotational band has very similar energies to the yrast sequence in {sup 46}Ti and is therefore assumed to be a T=1 configuration.

Evidence for second-phonon nuclear wobbling

International Nuclear Information System (INIS)

Jensen, D.R.; Hagemann, G.B.; Herskind, B.; Sletten, G.; Wilson, J.N.; Hamamoto, I.; Odegaard, S.W.; Spohr, K.; Huebel, H.; Bringel, P.; Neusser, A.; Schoenwasser, G.; Singh, A.K.; Ma, W.C.; Amro, H.; Bracco, A.; Leoni, S.; Benzoni, G.; Maj, A.; Petrache, C.M.

2002-01-01

The nucleus 163 Lu has been populated through the reaction 139 La( 29 Si,5n) with a beam energy of 157 MeV. Three triaxial, strongly deformed (TSD) bands have been observed with very similar rotational properties. The first excited TSD band has earlier been assigned as a one-phonon wobbling excitation built on the lowest-lying (yrast) TSD band. The large B(E2) out /B(E2) in value obtainable for one of four observed transitions between the second and first excited TSD bands is in good agreement with particle-rotor calculations for a two-phonon wobbling excitation

Feeding of yrast states in 89Nb

International Nuclear Information System (INIS)

Berinde, A.; David, I.; Trache, L.

1986-01-01

The level structure of 89 Nb has been investigated using the ( 19 F, xnγ) reaction and gamma-ray spectrosocpy. The measurements were performed with the γ-γ coincidence technique using Ge(Li)-detectors. The direct feeding excitation functions of the quasirotational band levels and the angular distribution of gamma-rays have been measured in the ion energy range from 50 MeV to 70 MeV. New energy levels, their spins and parities are indicated. The data are explained on the basis of the shell model

Electromagnetic E2 Transition Probabilities in 120Xe And 118Te - N=66 Nuclei

International Nuclear Information System (INIS)

Pasternak, A.A.; Efimov, A.D.; Podsvirova, E.O.

2001-01-01

Lifetimes of the yrast states in 120 Xe and the ground state band below and above band crossing in 118 Te have been measured by DSAM in the 111 Cd( 12 C, 3n) reaction and by DSAM and RDM in the 109 Ag( 13 C, p3n) reaction, respectively. The experimental data are compared with calculation done in the framework of the IBM1 model in the 0(6) and SU(5) limits. (author)

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)

Identification of new negative-parity levels in 152,154Nd

International Nuclear Information System (INIS)

Zhang, X.Q.; Hamilton, J.H.; Ramayya, A.V.; Peker, L.K.; Hwang, J.K.; Jones, E.F.; Komicki, J.; Beyer, C.J.; Gore, P.M.; Babu, B.R.; Ginter, T.N.; Ter-Akopian, G.M.; Daniel, A.V.; Asztalos, S.J.; Chu, S.Y.; Gregorich, K.E.; Lee, I.Y.; Macchiavelli, A.O.; Macleod, R.W.; Rasmussen, J.O.; Gilat, J.; Ter-Akopian, G.M.; Oganessian, Y.T.; Daniel, A.V.; Ter-Akopian, G.M.; Daniel, A.V.; Ma, W.C.; Varmette, P.G.; Cole, J.D.; Aryaeinejad, R.; Butler-Moore, K.; Dardenne, Y.X.; Drigert, M.W.; Stoyer, M.A.; Wild, J.F.; Becker, J.A.; Bernstein, L.A.; Lougheed, R.W.; Moody, K.J.; Donangelo, R.; Prussin, S.G.; Griffin, H.C.

1998-01-01

From an experiment with Gammasphere and a 252 Cf spontaneous fission source, a new negative-parity band in 154 Nd and new negative-parity levels in 152 Nd were identified and the yrast bands were extended to 18 + in 154 Nd and 20 + in 152 Nd in a triple gamma coincidence study. These new negative-parity bands are consistent with octupole vibrational mode. There is a constant difference as a function of spin between the J 1 values for the negative-parity band in 152 Nd and J 1 for the similar negative-parity band in 154 Nd, however, their J 2 values are essentially identical. These bands indicate a new kind of identical band. copyright 1998 The American Physical Society

Wobbling motion: A γ-rigid or γ-soft mode?

International Nuclear Information System (INIS)

Casten, R.F.; McCutchan, E.A.; Beausang, C.W.; Zamfir, N.V.; Zhang Jingye

2003-01-01

For even-even nuclei, it is shown that the predicted B(E2) values from the odd spin states of the quasi-γ band in a γ-soft nucleus to the yrast band are quite similar to those predicted for the one-phonon wobbling mode of a rigidly triaxial nucleus. This suggests that the observation of wobbling points to axial asymmetry, but not necessarily to rigid triaxiality. However, another observable that does distinguish γ-soft from γ-rigid structure is identified

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.

Near-yrast spectroscopy of 164Yb and neighbouring nuclei

International Nuclear Information System (INIS)

Jonsson, S.; Roy, H. and others.

1983-03-01

High-spin states in 164 Yb have been populated in the 152 Sm( 16 0,4n) and 150 Sm( 18 0,4n) reactions. From studies of γ-γ coincidences, γ-ray angular distributions and conversion electron measurements the level scheme has been constructed. The g-band and the S-band have been established to spin and parity 22(sup)+ and 26(sup)+, respectively, and the rotational sequences (π,α)=(-,1) 1 , (-,0) 1 and (-,0) 2 to 23(sup)-, 24(sup)- and 18(sup)-, respectively. The sidebands in 162 , 164 Er and 164 , 166 Yb are discussed. Constructed two-quasineutron configurations and cranked shell model (CSM) calculations are compared with the experimental results in 164 Yb. Residual interactions between quasiparticles in 164 Yb are calculated. Crossing frequencies and the gain in alignment are summarized for the Yb isotopes and the main features are discussed. (author)

Lifetime measurements in the yrast band of the gamma-soft nuclei ...

Indian Academy of Sciences (India)

2016-06-15

Jun 15, 2016 ... ... J. Phys. (2016) 87: 7 c Indian Academy of Sciences ... +j. 1. Introduction. Shape deformations in nuclei are related to the gen- eral phenomenon of ... properties of various orbitals in which the nucleons move. Nuclei in the ...

Prediction of energies of yrast band in some even-even nuclei

International Nuclear Information System (INIS)

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

2012-01-01

The deformation parameter β and γ of the collective model of Bohr and Mottelson are basic descriptors of the nuclear equilibrium shape and structure. The researchers found that the values of γ obtained from energies (= γ e ) are nearly equal to the value of γ derived from transition rate (= γ b ) in even Xe, Ba and Ce nuclei (A∼120-140) and Hf, W, Os, Pt and Hg nuclei (A∼160-200) using rigid triaxial rotor model of Davydov-Filippov. In the present study, the relatively light mass nuclei (Mo, Ru and Pd) have been taken. As far as γ is concerned, it is known that the Ru chains of nuclei is intermediate between the two having opposite trends for parameter γ, decreasing for Mo and increasing for Pd, and has an irregular behaviour in itself with the increase of neutron number

The high-spin structure of 158Er - a theoretical study

International Nuclear Information System (INIS)

Bengtsson, Tord.

1990-01-01

To demonstrate the use of diabatic orbitals in high-spin calculations, the yrast structure of 158 Er is calculated and compared to experiment. A very satisfactory reproduction of the observed spectra is obtained form lowest spins through the collective bands up to band terminations. From results like this, a detailed understanding of the observed features emerge. In this case for example, the different alignment properties in negative parity bands can be understood as due to deformation differences and the existence of additional bands are predicted. Furthermore, the limitations of the cranked mean field approach can be investigated due to the high level of detail in this approach. (author)

Spectroscopy of 186 Pb with mass identification

International Nuclear Information System (INIS)

Baxter, A.M.; Byrne, A.P.; Australian National Univ., Canberra, ACT; Dracoulis, G.D.; Janssens, R.V.F.; Bearden, I.G.; Henry, R.G.

1993-10-01

Transitions in the very neutron-deficient isotope 186 Pb have been identified in mass-gated, recoil-γ and recoil-γ-γ coincidence data obtained with a Fragment Mass Analyser and Compton-suppressed Ge-detector array. The results of the present work confirm and extend a band of levels tentatively proposed in earlier work done elsewhere, and provide a definitive mass assignment of the observed transitions. The band observed in 186 Pb bears a very close resemblance to the yrast band in the isotones 184 Hg, supporting the view that the 186 Pb band is built upon a prolate structure. 11 refs., 4 figs., 1 tab

High-spin structure of the neutron-rich odd-odd sup 1 sup 0 sup 6 sup , sup 1 sup 0 sup 8 sub 4 sub 5 Rh and sup 1 sup 1 sup 0 sup , sup 1 sup 1 sup 2 sub 4 sub 7 Ag isotopes

CERN Document Server

Porquet, M G; Deloncle, I; Wilson, A; Venkova, T; Petkov, P; Kutsarova, T; Astier, A; Buforn, N; Meyer, M; Redon, N; Duprat, J; Gall, B J P; Hoellinger, F; Schulz, N; Gautherin, C; Lucas, R; Gueorguieva, E; Minkova, A; Sergolle, H

2002-01-01

The sup 1 sup 0 sup 6 sup , sup 1 sup 0 sup 8 Rh and sup 1 sup 1 sup 0 sup , sup 1 sup 1 sup 2 Ag nuclei have been produced as fission fragments following the fusion reaction sup 2 sup 8 Si+ sup 1 sup 7 sup 6 Yb at 145 MeV bombarding energy and studied with the Eurogam2 array. The yrast high-spin states of these four odd-odd nuclei, which are observed for the first time, consist of rotational bands in which the odd proton occupies the pi g sub 9 sub / sub 2 subshell and the odd neutron the nu h sub 1 sub 1 sub / sub 2 subshell. Their behaviour as a function of spin values does not vary with the number of neutrons: as observed in the odd-N neighbouring nuclei, the motion of the odd neutron remains decoupled from the motion of the core, from N=61 to N=65. Moreover, the staggering observed in the yrast bands of odd-odd isotopes is strongly reduced as compared to the large values displayed by the rotational bands built on the pi g sub 9 sub / sub 2 subshell in the odd-A Rh and Ag isotopes. The results of particle...

Collective properties of nucleons in the abnormal-parity states

International Nuclear Information System (INIS)

Bhatt, K. H.; Kahane, S.; Raman, S.

2000-01-01

In the first part of this work, we study the quadrupole collective properties of N a =2, 4, 6, and 8 nucleons occupying the abnormal-parity intruder single-particle states with high angular momenta j a =(9/2), (11/2), (13/2), and (15/2). This study is essential for a detailed understanding of the contribution made by these nucleons to the quadrupole collectivity of the yrast states of deformed nuclei. The properties studied include (i) the distribution of the angular momenta J contained in the intrinsic state of N a particles in the |j a k a > states, (ii) the relationship between the quadrupole moment Q 0 (j a ,N a ) of such an intrinsic state and the maximum angular momentum J max contained in it, (iii) the complete set of reduced quadrupole matrix elements (J ' ||Q||J) for transitions between all the states |J> and |J ' > projected from the intrinsic state, (iv) the B(E2:J→J-2) values, (v) the transition moments Q t (J), and (vi) the spectroscopic quadrupole moment Q(J). We compare these properties with similar properties of an intrinsic state having SU(3) symmetry which contains the same set of angular momenta as contained in the intrinsic state of a particular number of nucleons in a specific j a configuration. In the second part, we use the input from the first part to study the collective properties of the coupled system of protons and neutrons in abnormal-parity states. We show that the SU(3)-like features observed for the individual groups of abnormal-parity nucleons become stronger for the coupled system. Finally, in the third part, we consider the yrast bands of well-deformed nuclei projected from their Nilsson intrinsic states of valence nucleons in a major shell. We specify the structure of the wave function of each projected yrast state |J> in terms of the nucleons in both normal- and abnormal-parity states. These wave functions can be used to determine the individual contributions of the nucleons in normal- and abnormal-parity states to any

Sub-nanosecond Half-life Measurement of the Yrast I{sup π}=5{sup −} State in the N=78 Nucleus {sup 136}{sub 58}Ce using Fast-timing Coincident Gamma-ray Spectroscopy

Energy Technology Data Exchange (ETDEWEB)

Alharbi, T. [Department of Physics, University of Surrey, Guildford, GU2 7XH (United Kingdom); Department of Physics, Faculty of Science in Zulfi, Almajmaah University, P.O. Box 1712, 11932 (Saudi Arabia); Regan, P.H., E-mail: p.regan@surrey.ac.uk [Department of Physics, University of Surrey, Guildford, GU2 7XH (United Kingdom); National Physical Laboratory, Teddington, Middlesex, TW11 0LW (United Kingdom); Mărginean, N. [Horia Hulubei – National Institute for Physics and Nuclear Engineering (IFIN-HH), Bucharest (Romania); Podolyák, Zs.; Bajoga, A.; Britton, R. [Department of Physics, University of Surrey, Guildford, GU2 7XH (United Kingdom); Bucurescu, D.; Deleanu, D.; Filipescu, D.; Ghită, D.; Glodariu, T.; Mihai, C. [Horia Hulubei – National Institute for Physics and Nuclear Engineering (IFIN-HH), Bucharest (Romania); Mulholland, K. [School of Engineering, University of the West of Scotland, High Street, Paisley PA1 2BE (United Kingdom); Mărginean, R.; Negret, A.; Nita, C.R. [Horia Hulubei – National Institute for Physics and Nuclear Engineering (IFIN-HH), Bucharest (Romania); Patel, Z. [Department of Physics, University of Surrey, Guildford, GU2 7XH (United Kingdom); Roberts, O.J. [School of Computing Engineering and Mathematics, University of Brighton, Brighton, BN2 4GJ (United Kingdom); Stroe, L.; Sava, T. [Horia Hulubei – National Institute for Physics and Nuclear Engineering (IFIN-HH), Bucharest (Romania); and others

2014-06-15

We report on the measurement of the half-life of the yrast I{sup π}=5{sup −} state in the transitional nucleus {sup 136}Ce using a combined HPGe-LaBr3(Ce) scintillator gamma-ray detection array. The measured value for the E1 decay is approximately half a nanosecond, which corresponds to an E1 decay strength of approximately 2×10{sup −6} Wu. This value is in line with single-particle type E1 decays in this mass region and suggests no sign of additional K-hindrance associated with axially symmetric quadrupole deformations observed for lighter cerium isotopes.

Search for linking transitions in {sup 143}Eu

Energy Technology Data Exchange (ETDEWEB)

Lerma, F.; LaFosse, D.R.; Devlin, M. [Washington Univ., Saint Louis, MO (United States)] [and others

1996-12-31

Six SD bands were populated in {sup 143}Eu and {sup 144}Eu, two of which had not been previously observed. Sum spectra were generated to search for two step links from the yrast SD band in {sup 143}Eu. However, no two step links were found. A single link from the SD band in {sup 143}Eu was found at 3364 keV. The level where it feeds into has not been identified. Alpha-particle energy (E{sub {alpha}}) spectra leading to the SD band and to normal states in {sup 143}Eu were measured and a correlation was found between E{sub {alpha}} and the level spin of the residual nucleus.

Shape coexistence in selenium isotopes

International Nuclear Information System (INIS)

Liu Ying; Cao Zhongbin; Xu Furong

2010-01-01

Nuclear shape change and shape coexistence in the Selenium isotopes have been investigated by Total-Routhian-Surface (TRS) calculations. It is found that nuclear shapes vary significantly with increasing neutron number. The TRS calculations for the ground states of 66,72,92,94 Se isotopes show that both neutron-deficient and neutron-dripline Selenium isotopes have oblate and prolate shape coexistence. The cranking shell-model calculations for 72,94 Se give that prolate and oblate shape coexistence in low rotational frequency. However, oblate rotational bands disappear and prolate rotational bands become yrast bands with increasing rotational frequency, which is due to the intrusion of the g 9/2 orbitals. (authors)

Feeding and decay of superdeformed states

International Nuclear Information System (INIS)

Khoo, T.L.; Lauritsen, T.; Ahmad, I.; Carpenter, M.P.; Fernandez, P.B.; Janssens, R.V.F.; Moore, E.F.; Wolfs, F.L.H.; Benet, Ph.; Daly, P.J.; Beard, K.B.; Garg, U.; Ye, D.; Drigert, M.W.

1992-01-01

The mechanisms for feeding and decay of superdeformed (SD) bands are examined. Data connected with both processes in 192 Hg are compared with model calculations. The calculations successfully reproduce the data, suggesting that the mechanisms for both processes are understood. Constraints on the energy of the SD band energies and on the well-depths at low and high spins have been obtained. At the point of decay around spin 10, we suggest that the SD band is 3.3--4.3 MeV above the normal yrast line and that the well depths at spin 10 and 40 are 0.5--1.3 and 3.5--4.5 MeV, respectively

New level schemes with high-spin states of 105,107,109Tc

International Nuclear Information System (INIS)

Luo, Y.X.; Rasmussen, J.O.; Lee, I.Y.; Fallon, P.; Hamilton, J.H.; Ramayya, A.V.; Hwang, J.K.; Gore, P.M.; Zhu, S.J.; Wu, S.C.; Ginter, T.N.; Ter-Akopian, G.M.; Daniel, A.V.; Stoyer, M.A.; Donangelo, R.; Gelberg, A.

2004-01-01

New level schemes of odd-Z 105,107,109 Tc are proposed based on the 252 Cf spontaneous-fission-gamma data taken with Gammasphere in 2000. Bands of levels are considerably extended and expanded to show rich spectroscopic information. Spin/parity and configuration assignments are made based on determinations of multipolarities of low-lying transitions and the level analogies to the previously reported levels, and to those of the neighboring Rh isotopes. A non-yrast negative-parity band built on the 3/2 - [301] orbital is observed for the first time in 105 Tc. A positive-parity band built on the 1/2 + [431] intruder orbital originating from the π(g 7/2 /d 5/2 ) subshells and having a strong deformation-driving effect is observed for the first time in 105 Tc, and assigned in 107 Tc. A positive-parity band built on the excited 11/2 + level, which has rather low excitation energy and predominantly decays into the 9/2 + level of the ground state band, provides evidence of triaxiality in 107,109 Tc, and probably also in 105 Tc. Rotational constants are calculated and discussed for the K=1/2 intruder bands using the Bohr-Mottelson formula. Level systematics are discussed in terms of the locations of proton Fermi levels and deformations. The band crossings of yrast positive-parity bands are observed, most likely related to h 11/2 neutron alignment. Triaxial-rotor-plus-particle model calculations performed with ε=0.32 and γ=-22.5 deg. on the prolate side of maximum triaxiality yielded the best reproduction of the excitation energies, signature splittings, and branching ratios of the positive-parity bands (except for the intruder bands) of these Tc isotopes. The significant discrepancies between the triaxial-rotor-plus-particle model calculations and experiment for the K=1/2 intruder bands in 105,107 Tc need further theoretical studies

Backbending phenomenon in {sup 48}Cr

Energy Technology Data Exchange (ETDEWEB)

Tanaka, T. [Tohoku Univ., Sendai (Japan); Iwasawa, K.; Sakata, F.; Marumori, T.

1998-07-01

A new mechanism of the backbending phenomena is discussed by analysing the yrast band of {sup 48}Cr where no single-particle level-crossing is expected. It is pointed out that a full self-consistent mean-field treatment by properly taking into account of the two-body interaction is crucial in explaining the backbending phenomena which occur within the fp-shell without any intruder orbits. (author)

Quadrupole moments of wobbling excitations in 163Lu

International Nuclear Information System (INIS)

Goergen, A.; Clark, R.M.; Cromaz, M.; Fallon, P.; Lee, I.Y.; Macchiavelli, A.O.; Ward, D.; Hagemann, G.B.; Sletten, G.; Huebel, H.; Bengtsson, R.

2004-01-01

Lifetimes of states in the triaxial strongly deformed bands of 163 Lu have been measured with the Gammasphere spectrometer using the Doppler-shift attenuation method. The bands have been interpreted as wobbling-phonon excitations from the characteristic electromagnetic properties of the transitions connecting the bands. Quadrupole moments are extracted for the zero-phonon yrast band and, for the first time, for the one-phonon wobbling band. The very similar results found for the two bands suggest a similar intrinsic structure and support the wobbling interpretation. While the in-band quadrupole moments for the bands show a decreasing trend towards higher spin, the ratio of the interband to the in-band transition strengths remains constant. Both features can be understood by a small increase in triaxiality towards higher spin. Such a change in triaxiality is also found in cranking calculations, to which the experimental results are compared

First Evidence for the Wobbling Mode in A Triaxial Superdeformed Odd-A Nucleus

International Nuclear Information System (INIS)

Hamamoto, I.; Odegaerd, S.W.; Hagemann, G.B.

2001-01-01

The wobbling mode is uniquely related to rotation of a triaxial body. The Lu-Hf isotopes with N ∼ 94 provides a possible region of nuclei with pronounced triaxiality. We have investigated 163 Lu through the fusion- evaporation reaction 139 La( 29 Si,5n) 163 Lu with a beam energy of 152 MeV. The electromagnetic properties of several connecting transitions between two presumably Triaxial, Super Deformed (TSD) bands have been studied. New particle-rotor calculations in which an aligned i 13/2 proton is coupled to a ''wobbling'' core are presented and evidence for the assignment of the excited TSD band as a wobbling mode built on the yrast TSD band in 163 Lu is given. (author)

Microscopic structure of high-spin vibrational states in superdeformed A=190 nuclei

Energy Technology Data Exchange (ETDEWEB)

Nakatsukasa, Takashi [Chalk River Labs., Ontario (Canada); Matsuyanagi, Kenichi [Kyoto Univ. (Japan); Mizutori, Shoujirou [Oak Ridge National Lab., TN (United States)] [and others

1996-12-31

Microscopic RPA calculations based on the cranked shell model are performed to investigate the quadrupole and octupole correlations for excited superdeformed (SD) bands in even-even A=190 nuclei. The K = 2 octupole vibrations are predicted to be the lowest excitation modes at zero rotational frequency. The Coriolis coupling at finite frequency produces different effects depending on the neutron and proton number of nucleus. The calculations also indicate that some collective excitations may produce moments of inertia almost identical to those of the yrast SD band. An interpretation of the observed excited bands invoking the octupole vibrations is proposed, which suggests those octupole vibrations may be prevalent in even-even SD A=190 nuclei.

Quasi-SU(3) truncation scheme for even-even sd-shell nuclei

International Nuclear Information System (INIS)

Vargas, C.E.; Hirsch, J.G.; Draayer, J.P.

2001-01-01

The quasi-SU(3) symmetry was uncovered in full pf and sdg shell-model calculations for both even-even and odd-even nuclei. It manifests itself through a dominance of single-particle and quadrupole-quadrupole terms in a Hamiltonian used to describe well-deformed nuclei. A practical consequence of the quasi-SU(3) symmetry is an efficient basis truncation scheme. In [C.E. Vargas et al., Phys. Rev. C 58 (1998) 1488] it is shown that when this type of Hamiltonian is diagonalized in an SU(3) basis, only a few irreducible representations (irreps) of SU(3) are needed to describe the yrast band, the leading S=0 irrep augmented with the leading S=1 irreps in the proton and neutron subspaces. In the present article the quasi-SU(3) truncation scheme is used, in conjunction with a 'realistic but schematic' Hamiltonian that includes the most important multipole terms, to describe the energy spectra and B(E2) transition strengths of 20,22 Ne, 24 Mg and 28 Si. The effect of the size of the Hilbert space on both sets of observables is discussed, as well as the structure of the yrast band and the importance of the various terms in the Hamiltonian. The limitations of the model are explicitly discussed

Shape transitions in neutron rich 110-112Ru nuclei and empirical relations

International Nuclear Information System (INIS)

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

2010-01-01

In the study of even even neutron rich Ru isotopes, the electromagnetic properties of the γ-vibrational bands are well described by a rigid triaxial rotor for lower spin state and by the rotation vibration collective model for the higher spin states. Thus interpretation in further suggested by the observation of nearly identical moment of inertia, the rotational frequency below the first band crossing, between the ground state and the γ-structural bands for both 110 Ru and 112 Ru which conclude a weak pairing, a more likely suitable explanation of observations. In the present work, the soft rotor energy formula is undertaken suggested by Brentano et al. for yrast band, may be employed to calculate the perturbed energies of the anomalous rotational band (γ-band) generated by rotation of the rigid asymmetric atomic nucleus and the two parameter formula (TPF) of Gupta et al.

Yrast spectroscopy in the neutron-deficient nucleus 169Os

International Nuclear Information System (INIS)

Joss, D.T.; Simpson, J.; Appelbe, D.E.; Warner, D.D.; Page, R.D.; King, S.L.; Amzal, N.; Cullen, D.M.; Greenlees, P.T.; Keenan, A.; Baeck, T.; Cederwall, B.; Wyss, R.; Bentley, M.A.; Williams, S.J.; Cocks, J.F.C.; Helariutta, K.; Jones, P.M.; Julin, R.; Juutinen, S.

2002-01-01

Excited states in the neutron-deficient isotope 169 Os have been identified for the first time in an experiment using the Jurosphere γ-ray spectrometer in conjunction with the Ritu gas-filled recoil separator. The problems associated with identifying neutron-deficient isotopes produced with low fusion cross sections against a high background of competing channels, including fission, have been overcome by using the recoil-decay tagging technique. The band structures observed in 169 Os are interpreted in the context of the systematics of neighboring nuclei and the predictions of cranked Woods-Saxon calculations. The systematics of the second (i 13/2 ) 2 neutron alignment in this region are discussed

The Fifteen Oes, the "Disticha Catonis," Marculfius, and Dick, Jane, and Sally

Science.gov (United States)

Noakes, Susan

1977-01-01

Available from: University of Chicago Library Society Bulletin, c/o Harriet Clouse, Library Development Office, Regenstein Library, University of Chicago, Chicago, Illinois; $7.50 per year; issued irregularly 2-3/year. Discusses late-medieval primary education, especially learning to read; indicates how such education affected the way adults used…

Projected shell model description of N = 114 superdeformed isotone nuclei

International Nuclear Information System (INIS)

Guo, R S; Chen, L M; Chou, C H

2006-01-01

A systematic description of the yrast superdeformed (SD) bands in N 114, Z = 80-84 isotone nuclei using the projected shell model is presented. The calculated γ-ray energies, moment of inertia and M1 transitions are compared with the data for which spin is assigned. Excellent agreement with the available data for all isotones is obtained. The calculated electromagnetic properties provide a microscopic understanding of those measured nuclei. Some predictions in superdeformed nuclei are also discussed

The hierarchically organized splitting of chromosome bands into sub-bands analyzed by multicolor banding (MCB).

Science.gov (United States)

Lehrer, H; Weise, A; Michel, S; Starke, H; Mrasek, K; Heller, A; Kuechler, A; Claussen, U; Liehr, T

2004-01-01

To clarify the nature of chromosome sub-bands in more detail, the multicolor banding (MCB) probe-set for chromosome 5 was hybridized to normal metaphase spreads of GTG band levels at approximately 850, approximately 550, approximately 400 and approximately 300. It could be observed that as the chromosomes became shorter, more of the initial 39 MCB pseudo-colors disappeared, ending with 18 MCB pseudo-colored bands at the approximately 300-band level. The hierarchically organized splitting of bands into sub-bands was analyzed by comparing the disappearance or appearance of pseudo-color bands of the four different band levels. The regions to split first are telomere-near, centromere-near and in 5q23-->q31, followed by 5p15, 5p14, and all GTG dark bands in 5q apart from 5q12 and 5q32 and finalized by sub-band building in 5p15.2, 5q21.2-->q21.3, 5q23.1 and 5q34. The direction of band splitting towards the centromere or the telomere could be assigned to each band separately. Pseudo-colors assigned to GTG-light bands were resistant to band splitting. These observations are in concordance with the recently proposed concept of chromosome region-specific protein swelling. Copyright 2003 S. Karger AG, Basel

Projected shell model study of yrast states of neutron-deficient odd-mass Pr nuclei

International Nuclear Information System (INIS)

Ibanez-Sandoval, A.; Ortiz, M. E.; Velazquez, V.; Galindo-Uribarri, A.; Hess, P. O.; Sun, Y.

2011-01-01

A wide variety of modern instruments allow us to study neutron-deficient nuclei in the A=130 mass region. Highly deformed nuclei have been found in this region, providing opportunities to study the deformed rotational bands. The description of the 125,127,129,131,133 Pr isotopes with the projected shell model is presented in this paper. Good agreement between theory and experiment is obtained and some characteristics are discussed, including the dynamic moment of inertia J (2) , kinetic moment of inertia J (1) , the crossing of rotational bands, and backbending effects.

Quasi-SU(3) truncation scheme for even-even sd-shell nuclei

Energy Technology Data Exchange (ETDEWEB)

Vargas, C.E. E-mail: cvargas@fis.cinvestav.mx; Hirsch, J.G. E-mail: hirsch@nuclecu.unam.mx; Draayer, J.P. E-mail: draayer@lsu.edu

2001-07-30

The quasi-SU(3) symmetry was uncovered in full pf and sdg shell-model calculations for both even-even and odd-even nuclei. It manifests itself through a dominance of single-particle and quadrupole-quadrupole terms in a Hamiltonian used to describe well-deformed nuclei. A practical consequence of the quasi-SU(3) symmetry is an efficient basis truncation scheme. In [C.E. Vargas et al., Phys. Rev. C 58 (1998) 1488] it is shown that when this type of Hamiltonian is diagonalized in an SU(3) basis, only a few irreducible representations (irreps) of SU(3) are needed to describe the yrast band, the leading S=0 irrep augmented with the leading S=1 irreps in the proton and neutron subspaces. In the present article the quasi-SU(3) truncation scheme is used, in conjunction with a 'realistic but schematic' Hamiltonian that includes the most important multipole terms, to describe the energy spectra and B(E2) transition strengths of {sup 20,22}Ne, {sup 24}Mg and {sup 28}Si. The effect of the size of the Hilbert space on both sets of observables is discussed, as well as the structure of the yrast band and the importance of the various terms in the Hamiltonian. The limitations of the model are explicitly discussed.

Nuclear wobbling-phonon excitations with alignments

International Nuclear Information System (INIS)

Hamamoto, I.

2003-01-01

Wobbling-phonon excitations, which are recently observed in 71 163 Lu 92 , are studied. The presence of alignments in nuclei makes it easier for wobbling excitations to appear at lower angular momenta of the yrast spectra. A family of rotational bands with wobbling excitations, which have nearly the same nuclear intrinsic structure, have been pinned down by observing specific electromagnetic decay properties between them. The triaxiality parameter γ = +20 deg. is obtained for the nuclear shape from measured E2 transition probabilities

High-spin states in odd-odd 106,108,110,112Rh

International Nuclear Information System (INIS)

Fotiades, N.; Cizewski, J.A.; Kruecken, R.; McNabb, D.P.; Becker, J.A.; Bernstein, L.A.; Younes, W.; Clark, R.M.; Fallon, P.; Lee, I.Y.; Macchiavelli, A.O.

2003-01-01

The level structures of 106,108,110,112 Rh have been studied in the fission of the compound system formed in three different heavy-ion induced reactions. Sequences of five transitions, together with weak crossover transitions, have been assigned to each isotope based on coincidences with known transitions in the complementary fragments. Comparison with the lighter odd-odd Rh isotopes supports assignment of these sequences as the yrast bands built on the πg 9/2 xνh 11/2 configuration

Structure and symmetries of odd-odd triaxial nuclei

Energy Technology Data Exchange (ETDEWEB)

Palit, R. [Tata Institute of Fundamental Research, Department of Nuclear and Atomic Physics, Colaba, Mumbai (India); Bhat, G.H. [University of Kashmir, Department of Physics, Srinagar (India); Govt. Degree College Kulgam, Department of Physics, Kulgam (India); Sheikh, J.A. [University of Kashmir, Department of Physics, Srinagar (India); Cluster University of Srinagar, Srinagar, Jammu and Kashmir (India)

2017-05-15

Rotational spectra of odd-odd Rh and Ag isotopes are investigated with the primary motivation to search for the spontaneous chiral symmetry breaking phenomenon in these nuclei. The experimental results obtained on the degenerate dipole bands of some of these isotopes using a large array of gamma detectors are discussed and studied using the triaxial projected shell (TPSM) approach. It is shown that, first of all, to reproduce the odd-even staggering of the known yrast bands of these nuclei, large triaxial deformation is needed. This large triaxial deformation also gives rise to doublet band structures in many of these studied nuclei. The observed doublet bands in these isotopes are shown to be reproduced reasonably well by the TPSM calculations. Further, the TPSM calculations for neutron-rich nuclei indicate that the ideal manifestation of the chirality can be realised in {sup 106}Rh and {sup 112}Ag, where the doublet bands have similar electromagnetic properties along with small differences in excitation energies. (orig.)

Signature inversion in doubly odd 124La

International Nuclear Information System (INIS)

Chantler, H.J.; Paul, E.S.; Boston, A.J.; Choy, P.T.W.; Nolan, P.J.; Carpenter, M.P.; Davids, C.N.; Seweryniak, D.; Charity, R.; Devlin, M.; Sarantites, D.G.; Chiara, C.J.; Fossan, D.B.; Koike, T.; LaFosse, D.R.; Starosta, K.; Fletcher, A.M.; Smith, J.F.; Jenkins, D.G.; Kelsall, N.S.

2002-01-01

High-spin states have been studied in neutron-deficient 57 124 La 67 , populated through the 64 Zn( 64 Zn,3pn) reaction at 260 MeV. The Gammasphere γ-ray spectrometer has been used in conjunction with the Microball charged-particle detector, the Neutron Shell, and the Argonne Fragment Mass Analyzer, in order to select evaporation residues of interest. The known band structures have been extended and new bands found. Most of the bands are linked together, allowing more consistent spin and parity assignments. Comparison of band properties to cranking calculations has allowed configuration assignments to be made and includes the first identification of the g 9/2 proton-hole in an odd-odd lanthanum isotope. Two bands have been assigned a πh 11/2 xνh 11/2 structure; the yrast one exhibits a signature inversion in its level energies below I=18.5(ℎ/2π), while the excited one exhibits a signature inversion above I=18.5(ℎ/2π)

Mechanisms of Cytotoxicity of the Aids Virus

Science.gov (United States)

1992-10-10

Baskin , G.B., Cho, E.-S., Murphey-Corb, Skillman, D., Kalter, D.C., Orenstein, J.M., Hoover, M., Blumberg, B.M. & Epstein, L.G. (1988), Com- D.L...423-6. ciency virus type 1 negative factor (nef) is a transcriptional 20. Clouse KA, Robbins PB, Fernie B, et al. Viral antigen stimu- silencer. Proc

SINGLE-BAND, TRIPLE-BAND, OR MULTIPLE-BAND HUBBARD MODELS

NARCIS (Netherlands)

ESKES, H; SAWATZKY, GA

1991-01-01

The relevance of different models, such as the one-band t-J model and the three-band Emery model, as a realistic description of the electronic structure of high-T(c) materials is discussed. Starting from a multiband approach using cluster calculations and an impurity approach, the following

Shell structure and shape coexistence in {sup 195}Pb

Energy Technology Data Exchange (ETDEWEB)

Fant, B. [Helsinki Univ. (Finland). Dept. of Physics; Cederwall, B. [Royal Inst. of Tech., Physics Dept., Stockholm (Sweden); Cederkaell, J. [Royal Inst. of Tech., Physics Dept., Stockholm (Sweden); Norlin, L.O. [Royal Inst. of Tech., Physics Dept., Stockholm (Sweden); Wyss, R. [Royal Inst. of Tech., Physics Dept., Stockholm (Sweden); Fallon, P. [Lawrence Berkeley Lab., Berkeley, CA (United States); Beausang, C.W. [Oliver Lodge Lab., Univ. of Liverpool (United Kingdom); Butler, P.A. [Oliver Lodge Lab., Univ. of Liverpool (United Kingdom); Roberts, J.W. [Oliver Lodge Lab., Univ. of Liverpool (United Kingdom); Bruce, A.M. [Dept. of Mathematical Sciences, Univ. of Brighton (United Kingdom); Cullen, D.M. [Oak Ridge National Lab., TN (United States); Mullins, S.M. [Dept. of Physics and Astronomy, McMaster Univ., Hamilton, ON (Canada); Poynter, R.J. [Dept. of Physics, Univ. of York, Heslington (United Kingdom); Wadsworth, R. [Dept. of Physics, Univ. of York, Heslington (United Kingdom); Riley, M.A. [Florida State Univ., Tallahassee, FL (United States). Dept. of Physics; Korten, W. [Bonn Univ. (Germany). Inst. fuer Strahlen- und Kernphysik; Piiparinen, M.J. [Accelerator Lab., Univ. of Jyvaeskylae (Finland)

1995-12-31

{sup 195}Pb was investigated utilizing the reactions {sup 164}Dy({sup 36}S, 5n){sup 195}Pb and {sup 164}Dy({sup 34}S, 3n){sup 195}Pb at beam energies of 170 and 160 MeV respectively. Two new dipole bands which feed into the yrast 25/2{sup +} state, were found in {sup 195}Pb. The connection between the bands and the spherical states was established and thus spins and energies of the involved collective states were determined. The deformation is understood as mainly due to excitations of protons across the Z = 82 shell gap. The observed backbends are interpreted as alignment of i{sub 13/2} neutrons. (orig.).

Discrete spectroscopy in {sup 180}Os at high spins

Energy Technology Data Exchange (ETDEWEB)

Marti, G; Venkova, Ts; Morek, T; Schnare, H; Gast, W; Georgiev, A; Spohr, K M; Lieder, R M [Institut fuer Kernphysik, KFA-Juelich (Germany); Maier, K H [Hahn-Meitner-Institut Berlin GmbH (Germany); Zell, K O [Institut fuer Kernphysik, Universitaet Koeln (Germany)

1992-08-01

New information on rotational bands in {sup 180}Os was obtained from a discrete spectroscopy experiment in which the final nucleus was populated through the {sup 150}Nd({sup 36}S,6n) reaction at 177 MeV. A new strongly-coupled rotational band starting at a relatively high excitation energy was found. The observation and placement of the 185.6 keV in the level scheme gives strong support to a hypothetical 2-quasineutron configuration assigned to the 7{sup -} isomeric bands in {sup 180}Os and the isotone {sup 178}W. Band mixing between the (-,1){sub 1} and (-,1){sub 3} bands of same parity and signature was observed, and the interaction strength was estimated from experimental branching ratios. The authors` results confirm a previous assignment for the yrast and yrare sequences in this nucleus. With the identification of new transitions above the states with I {approx_equal} 24, previously assigned bands had to be revised, with the result that the second band crossing vanishes. 23 refs., 3 figs.

Final Programmatic Environmental Impact Statement, Lake Darling Flood Control Project, Souris River, North Dakota and Final Feature Environmental Impact Statement, Velva Flood Control, Velva, North Dakota.

Science.gov (United States)

1983-11-01

1500-1508) identify a process called "tiering" and define it as "...the coverage of general matters in broader environmental impact statements (such as...Mr. John Clouse Mr. C. R. Danks Sherwood, ND 58782 Rural Route Route 2 Foxholm, ND 58738 King’s Court Minot, ND 58701 Dr. A. B. Brudirk Mrs. Veronica

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.

Studies of normal deformation in {sup 151}Dy

Energy Technology Data Exchange (ETDEWEB)

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

1995-08-01

The wealth of data collected in the study of superdeformation in {sup 151}Dy allowed for new information to be obtained on the normally deformed structures in this nucleus. At high spin several new yrast states have been identified for the first time. They were associated with single-particle excitations. Surprisingly, a sequence was identified with energy spacings characteristic of a rotational band of normal ({beta}2 {approximately} 0.2) deformation. The bandhead spin appears to be 15/2{sup -} and the levels extend up to a spin of 87/2{sup -}. A clear backbend is present at intermediate spins. While a similar band based on a bandhead of 6{sup +} is known in {sup 152}Dy, calculations suggest that this collective prolate band should not be seen in {sup 151}Dy. In the experiment described earlier in this report that is aimed at determining the deformations associated with the SD bands in this nucleus and {sup 152}Dy, the deformation associated with this band will be determined. This will provide further insight into the origin of this band.

A Novel Ku-Band/Ka-Band and Ka-Band/E-Band Multimode Waveguide Couplers for Power Measurement of Traveling-Wave Tube Amplifier Harmonic Frequencies

Science.gov (United States)

Wintucky, Edwin G.; Simons, Rainee N.

2015-01-01

This paper presents the design, fabrication and test results for a novel waveguide multimode directional coupler (MDC). The coupler, fabricated from two dissimilar frequency band waveguides, is capable of isolating power at the second harmonic frequency from the fundamental power at the output port of a traveling-wave tube (TWT) amplifier. Test results from proof-of-concept demonstrations are presented for a Ku-band/Ka-band MDC and a Ka-band/E-band MDC. In addition to power measurements at harmonic frequencies, a potential application of the MDC is in the design of a satellite borne beacon source for atmospheric propagation studies at millimeter-wave (mm-wave) frequencies (Ka-band and E-band).

Superdeformation studies in {sup 191}Hg

Energy Technology Data Exchange (ETDEWEB)

Carpenter, M.P.; Janssens, R.V.F.; Crowell, B. [and others

1995-08-01

Superdeformation in the A {approximately} 190 region was first observed in {sup 191}Hg from an experiment performed at ATLAS using the Argonne Notre Dame {gamma}-ray facility. We recently revisited the study of superdeformation in this nucleus using Gammasphere and the {sup 160}Gd({sup 36}S,5n) and {sup 174}Yb({sup 22}Ne,5n) reactions at 172 and 120 MeV in order to populate and measure states in the second well. The goal of the experiment was to identify new bands in the data, and thus allow us to gain understanding on the relative placement of single particle orbitals near the N = 112 SD shell gap. From an analysis of the data, the three previously identified SD bands were extended, and their feeding into the yrast states delineated. Two new SD bands were observed and preliminary evidence for a third new band was obtained as well.

Wobbling phonon excitations, coexisting with normal deformed structures in 163Lu

International Nuclear Information System (INIS)

Jensen, D.R.; Hagemann, G.B.; Hamamoto, I.; Oedegard, S.W.; Bergstroem, M.; Herskind, B.; Sletten, G.; Toermaenen, S.; Wilson, J.N.; Tjoem, P.O.; Spohr, K.; Huebel, H.; Goergen, A.; Schoenwasser, G.; Bracco, A.; Leoni, S.; Maj, A.; Petrache, C.M.; Bednarczyk, P.; Curien, D.

2002-01-01

Wobbling is a rotational mode unique to a triaxial body. The Lu-Hf isotopes with N∼94 at high spin provide a possible region of nuclei with pronounced triaxiality. We have investigated 163 Lu through the fusion-evaporation reaction 139 La( 29 Si,5n) 163 Lu with a beam energy of 152 MeV. Three excited bands decaying into the known, presumably triaxial, superdeformed (TSD) band built on the i 13/2 proton orbital are observed. The electromagnetic properties of the connecting transitions from the two strongest populated excited TSD bands have been investigated. New particle-rotor calculations in which one i 13/2 quasiproton is coupled to the core of triaxial shape produce a variety of bands, whose properties can clearly be interpreted either as 'wobbling' or 'cranking' motion of the core. Evidence for the assignment of the excited TSD bands as one, and possibly even two wobbling phonon modes built on the yrast TSD band in 163 Lu is given. These triaxial bands coexist with bands built on quasiparticle excitations in the normal deformed (ND) minimum for which new data are also presented

The unpaired spectroscopy of sup 161,162 Er at spins up to 50 Dirac h

Energy Technology Data Exchange (ETDEWEB)

Riley, M.A.; Roberts, J.W.; Alderson, A.; Ali, I.; Cullen, D.M.; Fallon, P.; Forsyth, P.D.; Sharpey-Schafer, J.F. (Liverpool Univ. (UK). Oliver Lodge Lab.); Simpson, J.; Bentley, M.A.; Bruce, A.M. (Science and Engineering Research Council, Daresbury (UK). Daresbury Lab.); Chapman, R.; Lisle, J.C.; Mo, J.N. (Manchester Univ. (UK). Schuster Lab.)

1990-12-24

High spin states in {sup 161}Er and {sup 162}Er have been populated using the {sup 130}Te+{sup 36}S reaction at a bombarding energy of 170 MeV. In {sup 161}Er, three rotational bands were extended from I {approx equal} 35{Dirac h} to I {approx equal} 50{Dirac h}. In {sup 162}Er the positive parity yrast band was observed to I=44{Dirac h}. These rotational sequences are compared to a simple unpaired model which was successful in predicting the behaviour of similar high spin data on {sup 159,160}Er. These studies of the light Er isotopes constitute the highest spins observed in normal deformed nuclei and yield direct and specific information on the single-neutron spectrum of states. (orig.).

In-beam study of {sup 253}No using the SAGE spectrometer

Energy Technology Data Exchange (ETDEWEB)

Mistry, A.K.; Herzberg, R.D.; Butler, P.A.; Cox, D.M.; Joss, D.T.; Page, R.D.; Seddon, D.; Thornhill, J.; Wells, D. [University of Liverpool, Oliver Lodge Laboratory, Liverpool (United Kingdom); Greenlees, P.T.; Papadakis, P.; Auranen, K.; Grahn, T.; Jakobsson, U.; Julin, R.; Konki, J.; Leino, M.; Pakarinen, J.; Peura, P.; Rahkila, P.; Sandzelius, M.; Scholey, C.; Sorri, J.; Stolze, S.; Uusitalo, J. [University of Jyvaskyla, Department of Physics, Jyvaskyla (Finland); Garnsworthy, A.B.; Ketelhut, S. [University of British Columbia, TRIUMF, Vancouver, British Columbia (Canada); Hauschild, K.; Lopez-Martens, A. [Universite Paris-Sud, CSNSM, CNRS, IN2P3, Orsay (France); Simpson, J. [STFC, Daresbury Laboratory, Daresbury, Warrington (United Kingdom)

2017-02-15

The heavy actinide nucleus {sup 253}No (Z = 102) was studied using the (S)ilicon (A)nd (Ge)rmanium (SAGE) spectrometer allowing simultaneous in-beam γ-ray and conversion electron spectroscopy at the accelerator laboratory of the University of Jyvaeskylae. Using the recoil-tagging technique, γ-electron coincidences have allowed for the extension of the level scheme in the lower-spin region of the yrast band. In addition, internal conversion coefficient (ICC) measurements to establish the multipolarity of transitions have been performed. Measurement of the interband-intraband branching ratios supports the assignment of the Nilsson band-head configuration 9/2{sup -}[734] assigned in previous studies. The study shows the viability of combined in-beam electron and γ-ray spectroscopy down to μb cross sections. (orig.)

A high-spin isomer at high excitation energy in the neutron deficient nucleus $^{152}$Dy

CERN Document Server

Jansen, J F W; Chmielewska, D; De Meijer, R J

1976-01-01

A T/sub 1/2/=60+or-5 ns isomer at E/sub x/ approximately=5 MeV is found in the /sup 154/Gd( alpha ,6n)/sup 152/Dy reaction. The possible spin values are 15yrast line. The regular level sequence above the isomer may then be an evidence for a decoupled rotational band built on top of this state. (10 refs).

Lifetimes of high-spin states in {sup 162}Yb

Energy Technology Data Exchange (ETDEWEB)

Carpenter, M.P.; Janssens, R.V.F.; Henry, R.G. [and others

1995-08-01

A measurement on lifetimes of high-spin states in the yrast and near-yrast rotational bands in {sup 162}Yb was carried out at ATLAS in order to determine the evolution of collectivity as a function of angular momentum using the {sup 126}Te({sup 40}Ar,4n){sup 162}Yb reaction at 170 MeV. Previous lifetime measurements in the {sup 164,166,168}Yb isotopes showed a dramatic decrease in the transition quadrupole moment Q{sub t} with increasing spin. It was suggested that this decrease in Q{sub t} is brought about by the rotationally-induced deoccupation of high-j configurations, mainly i{sub 13/2} neutrons. If this interpretation is correct, the heavier isotopes should have a larger decrease in Q{sub t} than the lighter mass nuclides due to the position of the Fermi surface in the i{sub 13/2} subshell. Indeed, {sup 160}Yb does not show a clear decrease in Q{sub t} at high spin. No high spin lifetime information exists for {sup 162}Yb, thus this experiment fills the gap of measured Q{sub t}`s in the light Yb series. The data is currently being analyzed.

Reward banding to determine reporting rate of recovered mourning dove bands

Science.gov (United States)

Tomlinson, R.E.

1968-01-01

Reward bands placed on the other leg of certain regularly banded immature mourning doves (Zenaidura macroura) were used to develop information on reporting rates of recovered dove bands. Reports from 15 widely separated sections of the United States showed considerable variation in recovery rate of doves both with and without reward bands. The overall percentages of banded doves that were reported as recovered were 9.69% for those with reward bands and 3.83% for controls. The bandreporting rate for states influenced by publicity was 66%; that for states not influenced was 32%.

Search for and study of linking transitions between super- and normal deformed wells in the {sup 151}Tb nucleus; Recherche et etude de transitions de liaison entre les puits super- et normalement deformes dans le noyau {sup 151}Tb

Energy Technology Data Exchange (ETDEWEB)

Robin, J

2003-12-01

While the superdeformation phenomenon has been observed many times in different mass regions, the excitation energy and angular momentum are not known for most of the superdeformed bands, mainly in the A {approx} 150 mass region. We have thus undertaken the search for and study of linking transitions between super and normal deformed potential wells in the Tb{sup 151} nucleus with the EUROBALL-IV spectrometer based at the subatomic research institute of Strasbourg. This nucleus presents the peculiarity of having an excited superdeformed band identical to the yrast one of Dy{sup 152}, which has recently been linked to normal deformed states. As the Dy{sup 152} nucleus exhibits a shape coexistence in the first potential well, we have also searched for collective rotational bands with prolate but moderate shape, coexisting with the oblate structure of Tb{sup 151}. The discovery of new superdeformed bands in the Tb{sup 151,152} isotopes, the extension to lower and higher spins of the previously known bands, and mean field calculations with a deformed Woods-Saxon potential have contributed to improve our knowledge as well as raise new questions on the orbitals configuration assignments of these bands. (author)

Search for and study of linking transitions between super- and normal deformed wells in the 151Tb nucleus

International Nuclear Information System (INIS)

Robin, J.

2003-12-01

While the superdeformation phenomenon has been observed many times in different mass regions, the excitation energy and angular momentum are not known for most of the superdeformed bands, mainly in the A ∼ 150 mass region. We have thus undertaken the search for and study of linking transitions between super and normal deformed potential wells in the Tb 151 nucleus with the EUROBALL-IV spectrometer based at the subatomic research institute of Strasbourg. This nucleus presents the peculiarity of having an excited superdeformed band identical to the yrast one of Dy 152 , which has recently been linked to normal deformed states. As the Dy 152 nucleus exhibits a shape coexistence in the first potential well, we have also searched for collective rotational bands with prolate but moderate shape, coexisting with the oblate structure of Tb 151 . The discovery of new superdeformed bands in the Tb 151,152 isotopes, the extension to lower and higher spins of the previously known bands, and mean field calculations with a deformed Woods-Saxon potential have contributed to improve our knowledge as well as raise new questions on the orbitals configuration assignments of these bands. (author)

Dual-band frequency selective surface with large band separation and stable performance

Science.gov (United States)

Zhou, Hang; Qu, Shao-Bo; Peng, Wei-Dong; Lin, Bao-Qin; Wang, Jia-Fu; Ma, Hua; Zhang, Jie-Qiu; Bai, Peng; Wang, Xu-Hua; Xu, Zhuo

2012-05-01

A new technique of designing a dual-band frequency selective surface with large band separation is presented. This technique is based on a delicately designed topology of L- and Ku-band microwave filters. The two band-pass responses are generated by a capacitively-loaded square-loop frequency selective surface and an aperture-coupled frequency selective surface, respectively. A Faraday cage is located between the two frequency selective surface structures to eliminate undesired couplings. Based on this technique, a dual-band frequency selective surface with large band separation is designed, which possesses large band separation, high selectivity, and stable performance under various incident angles and different polarizations.

SHARPENDING OF THE VNIR AND SWIR BANDS OF THE WIDE BAND SPECTRAL IMAGER ONBOARD TIANGONG-II IMAGERY USING THE SELECTED BANDS

Directory of Open Access Journals (Sweden)

Q. Liu

2018-04-01

Full Text Available The Tiangong-II space lab was launched at the Jiuquan Satellite Launch Center of China on September 15, 2016. The Wide Band Spectral Imager (WBSI onboard the Tiangong-II has 14 visible and near-infrared (VNIR spectral bands covering the range from 403–990 nm and two shortwave infrared (SWIR bands covering the range from 1230–1250 nm and 1628–1652 nm respectively. In this paper the selected bands are proposed which aims at considering the closest spectral similarities between the VNIR with 100 m spatial resolution and SWIR bands with 200 m spatial resolution. The evaluation of Gram-Schmidt transform (GS sharpening techniques embedded in ENVI software is presented based on four types of the different low resolution pan band. The experimental results indicated that the VNIR band with higher CC value with the raw SWIR Band was selected, more texture information was injected the corresponding sharpened SWIR band image, and at that time another sharpened SWIR band image preserve the similar spectral and texture characteristics to the raw SWIR band image.

Dual-band frequency selective surface with large band separation and stable performance

International Nuclear Information System (INIS)

Zhou Hang; Qu Shao-Bo; Lin Bao-Qin; Wang Jia-Fu; Ma Hua; Zhang Jie-Qiu; Peng Wei-Dong; Bai Peng; Wang Xu-Hua; Xu Zhuo

2012-01-01

A new technique of designing a dual-band frequency selective surface with large band separation is presented. This technique is based on a delicately designed topology of L- and Ku-band microwave filters. The two band-pass responses are generated by a capacitively-loaded square-loop frequency selective surface and an aperture-coupled frequency selective surface, respectively. A Faraday cage is located between the two frequency selective surface structures to eliminate undesired couplings. Based on this technique, a dual-band frequency selective surface with large band separation is designed, which possesses large band separation, high selectivity, and stable performance under various incident angles and different polarizations. (electromagnetism, optics, acoustics, heat transfer, classical mechanics, and fluid dynamics)

General Relativistic Mean Field Theory for rotating nuclei

Energy Technology Data Exchange (ETDEWEB)

Madokoro, Hideki [Kyushu Univ., Fukuoka (Japan). Dept. of Physics; Matsuzaki, Masayuki

1998-03-01

The {sigma}-{omega} model Lagrangian is generalized to an accelerated frame by using the technique of general relativity which is known as tetrad formalism. We apply this model to the description of rotating nuclei within the mean field approximation, which we call General Relativistic Mean Field Theory (GRMFT) for rotating nuclei. The resulting equations of motion coincide with those of Munich group whose formulation was not based on the general relativistic transformation property of the spinor fields. Some numerical results are shown for the yrast states of the Mg isotopes and the superdeformed rotational bands in the A {approx} 60 mass region. (author)

Combined in-beam electron and γ-ray spectroscopy of 184,186Hg

International Nuclear Information System (INIS)

Scheck, M.; Butler, P. A.; Gaffney, L. P.; Carrol, R. J.; Cox, D.; Joss, D. T.; Herzberg, R.-D.; Page, R. D.; Papadakis, P.; Watkins, H. V.; Bree, N.; Huyse, M.; Van Duppen, P.; Grahn, T.; Greenlees, P. T.; Herzan, A.; Jakobsson, U.; Jones, P.; Julin, R.; Juutinen, S.

2011-01-01

By exploiting the SAGE spectrometer a simultaneous measurement of conversion electrons and γ rays emitted in the de-excitation of excited levels in the neutron-deficient nuclei 184,186 Hg was performed. The light Hg isotopes under investigation were produced using the 4n channels of the fusion-evaporation reactions of 40 Ar and 148,150 Sm. The measured K- and L-conversion electron ratios confirmed the stretched E2 nature of several transitions of the yrast bands in 184,186 Hg. Additional information on the E0 component of the 2 2 + →2 1 + transition in 186 Hg was obtained.

Combined in-beam electron and gamma-ray spectroscopy of (184,186)Hg

CERN Document Server

Scheck, M; Rahkila, P; Butler, P A; Larsen, A C; Sandzelius, M; Scholey, C; Carrol, R J; Papadakis, P; Jakobsson, U; Grahn, T; Joss, D T; Watkins, H V; Juutinen, S; Bree, N; Cox, D; Huyse, M; Uusitalo, J; Leino, M; Ruotsalainen, P; Nieminen, P; Srebrny, J; Van Duppen, P; Herzan, A; Greenlees, P T; Julin, R; Herzberg, R D; Hauschild, K; Pakarinen, J; Page, R D; Peura, P; Gaffney, L P; Kowalczyk, M; Rinta-Antila, S; Saren, J; Lopez-Martens, A; Sorri, J; Ketelhut, S

2011-01-01

By exploiting the SAGE spectrometer a simultaneous measurement of conversion electrons and gamma rays emitted in the de-excitation of excited levels in the neutron-deficient nuclei (184,186)Hg was performed. The light Hg isotopes under investigation were produced using the 4n channels of the fusion-evaporation reactions of (40)Ar and (148,150)Sm. The measured K- and L-conversion electron ratios confirmed the stretched E2 nature of several transitions of the yrast bands in (184,186)Hg. Additional information on the E0 component of the 2(2)(+) -> 2(1)(+) transition in (186)Hg was obtained.

Study on the high-spin states and signature inversion of odd-odd nucleus 170Ta

International Nuclear Information System (INIS)

Deng Fuguo; Zhou Hongyu; Sun Huibin; Lu Jingbin; Zhao Guangyi; Yin Lichang; Liu Yunzuo

2002-01-01

The high-spin states of odd-odd nucleus 170 Ta were populated via the 155 Gd( 19 F, 4n) 170 Ta reaction with beam energy of 97 MeV provided by the HI-13 tandem accelerator of China Institute of Atomic Energy. Three rotational bands have been pushed to higher spin states and the signature inversion point of the semidecoupled band based on the πh 9/2 1/2 - [541] direct x νi 13/2 configuration has been observed to be 19.5 ℎ. The systematic features of the signature inversion in semidecoupled bands in odd-odd rare earth nuclei were summarized. The systematic differences of signature inversion, especially the difference in the energy splitting between the yrast hands and the semidecoupled hands in odd-odd rare earth nuclei are pointed out and discussed for the first time. It seems that p-n interaction between the odd proton and odd neutron in the odd-odd nuclei plays an important role

Band structure of semiconductors

CERN Document Server

Tsidilkovski, I M

2013-01-01

Band Structure of Semiconductors provides a review of the theoretical and experimental methods of investigating band structure and an analysis of the results of the developments in this field. The book presents the problems, methods, and applications in the study of band structure. Topics on the computational methods of band structure; band structures of important semiconducting materials; behavior of an electron in a perturbed periodic field; effective masses and g-factors for the most commonly encountered band structures; and the treatment of cyclotron resonance, Shubnikov-de Haas oscillatio

Atomic-Monolayer MoS2 Band-to-Band Tunneling Field-Effect Transistor

KAUST Repository

Lan, Yann Wen

2016-09-05

The experimental observation of band-to-band tunneling in novel tunneling field-effect transistors utilizing a monolayer of MoS2 as the conducting channel is demonstrated. Our results indicate that the strong gate-coupling efficiency enabled by two-dimensional materials, such as monolayer MoS2, results in the direct manifestation of a band-to-band tunneling current and an ambipolar transport.

On the Bengtsson-Frauendorf cranked-quasiparticle model

International Nuclear Information System (INIS)

Pal, K.F.; Nagarajan, M.A.; Rowley, N.

1989-01-01

The cranked-quasiparticle model of Bengtsson and Frauendorf (non-self-consistent HFB) is compared with some exact calculations of particles moving in a cranked, deformed mean field but interacting via rotationally invariant two-body forces. In order to make the exact calculations manageable, a single shell is used but despite this small basis the quasiparticle model is shown to have a high degree of success. The usual choice of pair gap is discussed and shown to be good. The general structures of band crossings in the exact calculations are well reproduced and some crossing frequencies are given quantitatively though the odd-particle systems require blocking. Interaction strengths are not well reproduced though some qualitative features, e.g. oscillations, are obtained. These interactions are generally underestimated, an effect which causes the HFB yrast band to behave less collectively than it should. (orig.)

Band-notched spiral antenna

Science.gov (United States)

Jeon, Jae; Chang, John

2018-03-13

A band-notched spiral antenna having one or more spiral arms extending from a radially inner end to a radially outer end for transmitting or receiving electromagnetic radiation over a frequency range, and one or more resonance structures positioned adjacent one or more segments of the spiral arm associated with a notch frequency band or bands of the frequency range so as to resonate and suppress the transmission or reception of electromagnetic radiation over said notch frequency band or bands.

Congenital Constriction Band Syndrome

OpenAIRE

Rajesh Gupta, Fareed Malik, Rishabh Gupta, M.A.Basit, Dara Singh

2008-01-01

Congenital constriction bands are anomalous bands that encircle a digit or an extremity. Congenitalconstriction band syndrome is rare condition and is mostly associated with other musculoskeletaldisorders.We report such a rare experience.

Single-Band and Dual-Band Infrared Detectors

Science.gov (United States)

Ting, David Z. (Inventor); Gunapala, Sarath D. (Inventor); Soibel, Alexander (Inventor); Nguyen, Jean (Inventor); Khoshakhlagh, Arezou (Inventor)

2017-01-01

Bias-switchable dual-band infrared detectors and methods of manufacturing such detectors are provided. The infrared detectors are based on a back-to-back heterojunction diode design, where the detector structure consists of, sequentially, a top contact layer, a unipolar hole barrier layer, an absorber layer, a unipolar electron barrier, a second absorber, a second unipolar hole barrier, and a bottom contact layer. In addition, by substantially reducing the width of one of the absorber layers, a single-band infrared detector can also be formed.

Recent developments of the projected shell model based on many-body techniques

Directory of Open Access Journals (Sweden)

Sun Yang

2015-01-01

Full Text Available Recent developments of the projected shell model (PSM are summarized. Firstly, by using the Pfaffian algorithm, the multi-quasiparticle configuration space is expanded to include 6-quasiparticle states. The yrast band of 166Hf at very high spins is studied as an example, where the observed third back-bending in the moment of inertia is well reproduced and explained. Secondly, an angular-momentum projected generate coordinate method is developed based on PSM. The evolution of the low-lying states, including the second 0+ state, of the soft Gd, Dy, and Er isotopes to the well-deformed ones is calculated, and compared with experimental data.

Seniority structure of the cranked shell model wave function and the pairing phase transition

International Nuclear Information System (INIS)

Wu, C.S.; Zeng, J.Y.; Center of Theoretical Physics, China Center of Advanced Science and Technology

1989-01-01

The accurate solutions to the low-lying eigenstates of the cranked shell model Hamiltonian are obtained by the particle-number-conserving treatment, in which a many-particle configuration truncation is adopted instead of the conventional single-particle level truncation. The variation of the seniority structures of low-lying eigenstates with rotational frequency ω is analyzed. The gap parameter of the yrast band decreases with ω very slowly, though the seniority structure has undergone a great change. It is suggested to use the seniority structure to indicate the possible pairing phase transition from a superconducting state to a normal state. The important blocking effects on the low-lying eigenstates are discussed

Nuclear spectroscopy of doubly-even130,132Ba

Science.gov (United States)

Gupta, Anuradha; Gupta, Surbhi; Singh, Suram; Bharti, Arun

2018-05-01

A comparative study of some high-spin characteristic nuclear structure properties of doubly-even 130,132Ba nuclei has been made using two microscopic frameworks - CHFB and PSM. The yrast spectra, intrinsic quadrupole moment and deformation systematics of these nuclei have been successfully calculated. Further, the calculated data from both the frameworks is also compared with the available experimental data and a good agreement has been obtained. The present CHFB calculations describes very well the low spin structure of even-even 130,132Ba nuclei whereas PSM calculations provide a qualitative description of the high-spin band structure of doubly-even 130,132Ba nuclei.

Band Edge Dynamics and Multiexciton Generation in Narrow Band Gap HgTe Nanocrystals.

Science.gov (United States)

Livache, Clément; Goubet, Nicolas; Martinez, Bertille; Jagtap, Amardeep; Qu, Junling; Ithurria, Sandrine; Silly, Mathieu G; Dubertret, Benoit; Lhuillier, Emmanuel

2018-04-11

Mercury chalcogenide nanocrystals and especially HgTe appear as an interesting platform for the design of low cost mid-infrared (mid-IR) detectors. Nevertheless, their electronic structure and transport properties remain poorly understood, and some critical aspects such as the carrier relaxation dynamics at the band edge have been pushed under the rug. Some of the previous reports on dynamics are setup-limited, and all of them have been obtained using photon energy far above the band edge. These observations raise two main questions: (i) what are the carrier dynamics at the band edge and (ii) should we expect some additional effect (multiexciton generation (MEG)) as such narrow band gap materials are excited far above the band edge? To answer these questions, we developed a high-bandwidth setup that allows us to understand and compare the carrier dynamics resonantly pumped at the band edge in the mid-IR and far above the band edge. We demonstrate that fast (>50 MHz) photoresponse can be obtained even in the mid-IR and that MEG is occurring in HgTe nanocrystal arrays with a threshold around 3 times the band edge energy. Furthermore, the photoresponse can be effectively tuned in magnitude and sign using a phototransistor configuration.

Noise exposure in marching bands

Science.gov (United States)

Keefe, Joseph

2005-09-01

Previous studies involving orchestras have shown that music ensembles can produce hazardous noise levels. There are no similar data for marching bands and pep bands. In order to evaluate the noise levels produced by marching and pep bands, 1/3-octave-band sound-pressure levels were measured while these groups rehearsed and performed. Data were collected while marching with the bands to ensure a realistic environment. Comparing these data to OSHA and NIOSH criteria, marching and pep band exposures often exceed safe values. For typical exposures, OSHA doses range from 11% to 295%, while NIOSH doses range from 35% to 3055%. Exposures that would be considered hazardous in the workplace are common in marching and pep bands; students and band directors should take steps to recognize the risk posed by various instruments and various locations, and should implement hearing conservation efforts.

B(M1) values in the band-crossing of shears bands in 197Pb

Science.gov (United States)

Krücken, R.; Cooper, J. R.; Beausang, C. W.; Novak, J. R.; Dewald, A.; Klug, T.; Kemper, G.; von Brentano, P.; Carpenter, M.; Wiedenhöver, I.

We present details of the band crossing mechanism of shears bands using the example of 197Pb. Absolute reduced matrix elements B(M1) were determined by means of a RDM lifetime measurement in one of the shears bands in 197Pb. The experiment was performed using the New Yale Plunger Device (NYPD) in conjunction with the Gammasphere array. Band mixing calculations on the basis of the semi-classical model of the shears mechanism are used to describe the transition matrix elements B(M1) and energies throughout the band-crossing regions. Good agreement with the data was obtained and the detailed composition of the states in the shears band are discussed.

Precipitation Estimation Using L-Band and C-Band Soil Moisture Retrievals

Science.gov (United States)

Koster, Randal D.; Brocca, Luca; Crow, Wade T.; Burgin, Mariko S.; De Lannoy, Gabrielle J. M.

2016-01-01

An established methodology for estimating precipitation amounts from satellite-based soil moisture retrievals is applied to L-band products from the Soil Moisture Active Passive (SMAP) and Soil Moisture and Ocean Salinity (SMOS) satellite missions and to a C-band product from the Advanced Scatterometer (ASCAT) mission. The precipitation estimates so obtained are evaluated against in situ (gauge-based) precipitation observations from across the globe. The precipitation estimation skill achieved using the L-band SMAP and SMOS data sets is higher than that obtained with the C-band product, as might be expected given that L-band is sensitive to a thicker layer of soil and thereby provides more information on the response of soil moisture to precipitation. The square of the correlation coefficient between the SMAP-based precipitation estimates and the observations (for aggregations to approximately100 km and 5 days) is on average about 0.6 in areas of high rain gauge density. Satellite missions specifically designed to monitor soil moisture thus do provide significant information on precipitation variability, information that could contribute to efforts in global precipitation estimation.

Search for asymmetric rotors in mass region A∼100

International Nuclear Information System (INIS)

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

2009-01-01

Recently in mass region a∼120-140 xenon and barium nuclei have been studied and the energy systematics have been drawn with excellent correlations in mass coefficient and rotation vibration interaction parameter with product of valance nucleons NpNn using three mass coefficients one each for yrast, odd and even γ-bands within the framework of general asymmetric rotor model. Interestingly in the mass region A ∼ 100 ruthenium nuclei have been dealt using similar approach but only one mass coefficient (B γ = B rot ) was found sufficient to reproduce the striking correlations among various parameters. The purpose of the present work is to study whether one mass coefficient works well in describing the inter band transitions in other nuclei in mass region a ∼ 100. We consider Mo, Ru and Pd nuclei and calculate the B(E2) values using asymmetric rotor model

ISM band to U-NII band frequency transverter and method of frequency transversion

Science.gov (United States)

Stepp, Jeffrey David [Grandview, MO; Hensley, Dale [Grandview, MO

2006-09-12

A frequency transverter (10) and method for enabling bi-frequency dual-directional transfer of digitally encoded data on an RF carrier by translating between a crowded or otherwise undesirable first frequency band, such as the 2.4 GHz ISM band, and a less-crowded or otherwise desirable second frequency band, such as the 5.0 GHz 6.0 GHz U-NII band. In a preferred embodiment, the transverter (10) connects between an existing data radio (11) and its existing antenna (30), and comprises a bandswitch (12); an input RF isolating device (14); a transmuter (16); a converter (18); a dual output local oscillator (20); an output RF isolating device (22); and an antenna (24) tuned to the second frequency band. The bandswitch (12) allows for bypassing the transverter (10), thereby facilitating its use with legacy systems. The transmuter (14) and converter (16) are adapted to convert to and from, respectively, the second frequency band.

Very extended shpaes in the A ∼ 150 mass region

International Nuclear Information System (INIS)

Chasman, R.R.

1995-01-01

There was a report of a rotational band in 152 Dy or 153 Dy that is characterized by a dynamic moment of inertia of 130h 2 MeV -1 . For purposes of orientation, it should be noted that the well known superdeformed bands in this region are characterized by moments of inertia of ∼90. Some calculations were carried out in two- and three-dimensional shape spaces, in order to understand this experimental observation. These calculations show either very shallow minima and/or minima that do not become yrast below I = 90 at the very large deformations that would seem to be required to explain such a large moment of inertia. We extended our four-dimensional deformation space Strutinsky calculations to a study of this mass region, with the hope of gaining some insight into the nature of this band. We are also analyzing the other nuclides of this mass region with the hope of finding other instances of such very extended shapes. This analysis is almost complete

Design of a side-band-separating heterodyne mixer for band 9 of ALMA

NARCIS (Netherlands)

Baryshev, AM; Kooi, J; Mena, FR; Lodewijk, CRJ; Wild, W

2005-01-01

A side-band-separating (SBS) heterodyne mixer has been designed for the Atacama Large Millimeter Array (ALMA) 602-720 GHz band, as it will present a great improvement over the current double-side-band configuration under development at the moment. Here we present design details and the results of

Collapse and revival in inter-band oscillations of a two-band Bose-Hubbard model

Energy Technology Data Exchange (ETDEWEB)

Ploetz, Patrick; Wimberger, Sandro [Institut fuer Theoretische Physik, Universitaet Heidelberg, Philosophenweg 19, 69120 Heidelberg (Germany); Madronero, Javier, E-mail: ploetz@thphys.uni-heidelberg.d [Physik Department, Technische Universitaet Muenchen, James-Franck-Str. 1, 85748 Garching (Germany)

2010-04-28

We study the effect of a many-body interaction on inter-band oscillations in a two-band Bose-Hubbard model with an external Stark force. Weak and strong inter-band oscillations are observed, where the latter arise from a resonant coupling of the bands. These oscillations collapse and revive due to a weak two-body interaction between the atoms. Effective models for oscillations in and out of resonance are introduced that provide predictions for the system's behaviour, particularly for the time scales for the collapse and revival of the resonant inter-band oscillations. (fast track communication)

Side-band-separating heterodyne mixer for band 9 of ALMA.

NARCIS (Netherlands)

Mena, F. P.; Baryshev, A. M.; Kooi, J.; Lodewijk, C. F. J.; Gerlofsma, G.; Hesper, R.; Wild, W.; Shen, XC; Lu, W; Zhang, J; Dou, WB

2006-01-01

Here we present the realization of a side-band-separating (2SB) heterodyne mixer for the frequency range from 602 to 720 GHz (corresponding to ALMA band 9). The mixer, in brief, consists of a quadrature hybrid, two LO injectors, two SIS junctions, and three dumping loads. All the parts were modeled

The DSS-14 C-band exciter

Science.gov (United States)

Rowan, D. R.

1989-01-01

The development and implementation of a C-band exciter for use with the Block IV Receiver-Exciter Subsystem at Deep Space Station 14 (DSS-14) has been completed. The exciter supplements the standard capabilities of the Block IV system by providing a drive signal for the C-band transmitter while generating coherent translation frequencies for C-band (5-GHz) to S-band (2.2- to 2.3-GHz) Doppler extraction, C-band to L-band (1.6-GHz) zero delay measurements, and a level calibrated L-band test signal. Exciter functions are described, and a general explanation and description of the C-band uplink controller is presented.

Transport in bilayer and trilayer graphene: band gap engineering and band structure tuning

Science.gov (United States)

Zhu, Jun

2014-03-01

Controlling the stacking order of atomically thin 2D materials offers a powerful tool to control their properties. Linearly dispersed bands become hyperbolic in Bernal (AB) stacked bilayer graphene (BLG). Both Bernal (ABA) and rhombohedral (ABC) stacking occur in trilayer graphene (TLG), producing distinct band structures and electronic properties. A symmetry-breaking electric field perpendicular to the sample plane can further modify the band structures of BLG and TLG. In this talk, I will describe our experimental effort in these directions using dual-gated devices. Using thin HfO2 film deposited by ALD as gate dielectric, we are able to apply large displacement fields D > 6 V/nm and observe the opening and saturation of the field-induced band gap Eg in bilayer and ABC-stacked trilayer graphene, where the conduction in the mid gap changes by more than six decades. Its field and temperature dependence highlights the crucial role played by Coulomb disorder in facilitating hopping conduction and suppressing the effect of Eg in the tens of meV regime. In contrast, mid-gap conduction decreases with increasing D much more rapidly in clean h-BN dual-gated devices. Our studies also show the evolution of the band structure in ABA-stacked TLG, in particular the splitting of the Dirac-like bands in large D field and the signatures of two-band transport at high carrier densities. Comparison to theory reveals the need for more sophisticated treatment of electronic screening beyond self-consistent Hartree calculations to accurately predict the band structures of trilayer graphene and graphenic materials in general.

Advances in X-Band and S-Band Linear Accelerators for Security, NDT, and Other Applications

CERN Document Server

Mishin, Andrey V

2005-01-01

At AS&E High Energy Systems Division, we designed several new advanced high energy electron beam and X-ray sources. Our primary focus has always been in building the world's most portable commercial X-band accelerators. Today, our X-band systems frequently exceed performance of the similar S-band machines, while they are more portable compared to the latter. The new designs of the X-band accelerators in the most practical energy range from 1 MeV to 6 MeV have been tested delivering outstanding results. Seventy 6 MeV X-band linacs systems have been produced. The most compact linac for security is used by AS&E in a self-shielded, Shaped Energy™ cargo screening system. We pioneered using the X-band linear accelerators for CT, producing high quality images of oil pipes and wood logs. An X-band linear accelerator head on a robotic arm has been used for electron beam radiation curing of an odd-shaped graphite composite part. We developed the broad-range 4 MeV to over 10 MeV energy-regulated X-band ...

Band gap and band offset of (GaIn)(PSb) lattice matched to InP

Science.gov (United States)

Köhler, F.; Böhm, G.; Meyer, R.; Amann, M.-C.

2005-07-01

Metastable (GaxIn1-x)(PySb1-y) layers were grown on (001) InP substrates by gas source molecular beam epitaxy. Low-temperature photoluminescence spectroscopy was applied to these heterostructures and revealed spatially indirect band-to-band recombination of electrons localized in the InP with holes in the (GaxIn1-x)(PySb1-y). In addition, samples with layer thicknesses larger than 100nm showed direct PL across the band gap of (GaxIn1-x)(PySb1-y). Band-gap energies and band offset energies of (GaxIn1-x)(PySb1-y) relative to InP were derived from these PL data. A strong bowing parameter was observed.

Dual-band infrared camera

Science.gov (United States)

Vogel, H.; Schlemmer, H.

2005-10-01

Every year, numerous accidents happen on European roads due to bad visibility (fog, night, heavy rain). Similarly, the dramatic aviation accidents of year 2001 in Milan and Zurich have reminded us that aviation safety is equally affected by reduced visibility. A dual-band thermal imager was developed in order to raise human situation awareness under conditions of reduced visibility especially in the automotive and aeronautical context but also for all transportation or surveillance tasks. The chosen wavelength bands are the Short Wave Infrared SWIR and the Long Wave Infrared LWIR band which are less obscured by reduced visibility conditions than the visible band. Furthermore, our field tests clearly show that the two different spectral bands very often contain complementary information. Pyramidal fusion is used to integrate complementary and redundant features of the multi-spectral images into a fused image which can be displayed on a monitor to provide more and better information for the driver or pilot.

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.

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.

Shell model for warm rotating nuclei

Energy Technology Data Exchange (ETDEWEB)

Matsuo, M.; Yoshida, K. [Kyoto Univ. (Japan); Dossing, T. [Univ. of Copenhagen (Denmark)] [and others

1996-12-31

Utilizing a shell model which combines the cranked Nilsson mean-field and the residual surface and volume delta two-body forces, the authors discuss the onset of rotational damping in normal- and super-deformed nuclei. Calculation for a typical normal deformed nucleus {sup 168}Yb indicates that the rotational damping sets in at around 0.8 MeV above the yrast line, and about 30 rotational bands of various length exists at a given rotational frequency, in overall agreement with experimental findings. It is predicted that the onset of rotational damping changes significantly in different superdeformed nuclei due to the variety of the shell gaps and single-particle orbits associated with the superdeformed mean-field.

50 MW C-band pulse klystron; 50MW C band pulse klystron

Energy Technology Data Exchange (ETDEWEB)

NONE

1999-03-01

C-band pulse klystron E3746 with an output of 50 MW class was developed jointly with the High-Energy Accelerator Research Organization in the Ministry of Education as the klystron for a linear accelerator. For a large-sized linear accelerator in the next generation, a klystron with higher operating frequency has been required to obtain a compact and efficient accelerator. In E3746, the problem of power resistance during high-frequency operation was solved by mounting a traveling-wave multi-cell output circuit. Moreover, stable operation in the pulse width of 2.5 {mu}s and the output of 54 MW was performed at the same operation efficiency (44%) as the conventional S-band tube by using the frequency (in a C-band frequency band) that is two times as high as the conventional general accelerator. (translated by NEDO)

Hazard banding in compliance with the new Globally Harmonised System (GHS) for use in control banding tools.

Science.gov (United States)

Arnone, Mario; Koppisch, Dorothea; Smola, Thomas; Gabriel, Stefan; Verbist, Koen; Visser, Remco

2015-10-01

Many control banding tools use hazard banding in risk assessments for the occupational handling of hazardous substances. The outcome of these assessments can be combined with advice for the required risk management measures (RMMs). The Globally Harmonised System of Classification and Labelling of Chemicals (GHS) has resulted in a change in the hazard communication elements, i.e. Hazard (H) statements instead of Risk-phrases. Hazard banding schemes that depend on the old form of safety information have to be adapted to the new rules. The purpose of this publication is to outline the rationales for the assignment of hazard bands to H statements under the GHS. Based on this, this publication proposes a hazard banding scheme that uses the information from the safety data sheets as the basis for assignment. The assignment of hazard bands tiered according to the severity of the underlying hazards supports the important principle of substitution. Additionally, the set of assignment rules permits an exposure-route-specific assignment of hazard bands, which is necessary for the proposed route-specific RMMs. Ideally, all control banding tools should apply the same assignment rules. This GHS-compliant hazard banding scheme can hopefully help to establish a unified hazard banding strategy in the various control banding tools. Copyright © 2015 Elsevier Inc. All rights reserved.

Band parameters of phosphorene

DEFF Research Database (Denmark)

Lew Yan Voon, L. C.; Wang, J.; Zhang, Y.

2015-01-01

Phosphorene is a two-dimensional nanomaterial with a direct band-gap at the Brillouin zone center. In this paper, we present a recently derived effective-mass theory of the band structure in the presence of strain and electric field, based upon group theory. Band parameters for this theory...... are computed using a first-principles theory based upon the generalized-gradient approximation to the density-functional theory. These parameters and Hamiltonian will be useful for modeling physical properties of phosphorene....

Computational Design of Flat-Band Material

Science.gov (United States)

Hase, I.; Yanagisawa, T.; Kawashima, K.

2018-02-01

Quantum mechanics states that hopping integral between local orbitals makes the energy band dispersive. However, in some special cases, there are bands with no dispersion due to quantum interference. These bands are called as flat band. Many models having flat band have been proposed, and many interesting physical properties are predicted. However, no real compound having flat band has been found yet despite the 25 years of vigorous researches. We have found that some pyrochlore oxides have quasi-flat band just below the Fermi level by first principles calculation. Moreover, their valence bands are well described by a tight-binding model of pyrochlore lattice with isotropic nearest neighbor hopping integral. This model belongs to a class of Mielke model, whose ground state is known to be ferromagnetic with appropriate carrier doping and on-site repulsive Coulomb interaction. We have also performed a spin-polarized band calculation for the hole-doped system from first principles and found that the ground state is ferromagnetic for some doping region. Interestingly, these compounds do not include magnetic element, such as transition metal and rare-earth elements.

Multi-band Modelling of Appearance

DEFF Research Database (Denmark)

Stegmann, Mikkel Bille; Larsen, Rasmus

2003-01-01

the appearance of both derived feature bands and an intensity band. As a special case of feature-band augmented appearance modelling we propose a dedicated representation with applications to face segmentation. The representation addresses a major problem within face recognition by lowering the sensitivity...

Multi-band Modelling of Appearance

DEFF Research Database (Denmark)

Stegmann, Mikkel Bille; Larsen, Rasmus

2002-01-01

the appearance of both derived feature bands and an intensity band. As a special case of feature-band augmented appearance modelling we propose a dedicated representation with applications to face segmentation. The representation addresses a major problem within face recognition by lowering the sensitivity...

Relaxation processes in rotational motion

International Nuclear Information System (INIS)

Broglia, R.A.

1986-01-01

At few MeV above the yrast line the normally strong correlations among γ-ray energies in a rotational sequence become weaker. This observation can be interpreted as evidence for the damping of rotational motion in hot nuclei. It seems possible to relate the spreading width of the E2-rotational decay strength to the spread in frequency Δω 0 of rotational bands. The origin of these fluctuations is found in: (1) fluctuations in the occupation of special single-particle orbits which contribute a significant part of the total angular momentum; and (2) fluctuations in the moment of inertia induced by vibrations of the nuclear shape. Estimates of Δω 0 done making use of the hundred-odd known discrete rotational bands in the rare-earth region lead, for moderate spin and excitation energies (I ≅ 30 and U ≅ 3 to 4 MeV), to rotational spreading widths of the order of 60 to 160 keV in overall agreement with the data. 24 refs

Evolution of the pi g sub 9 sub / sub 2 x nu h sub 1 sub 1 sub / sub 2 configuration in the neutron-rich sup 1 sup 1 sup 0 sup , sup 1 sup 1 sup 2 sub 4 sub 5 Rh and sup 1 sup 1 sup 4 sup , sup 1 sup 1 sup 6 sub 4 sub 7 Ag isotopes

CERN Document Server

Porquet, M G; Deloncle, I; Venkova, T; Astier, A; Buforn, N; Meyer, M; Prevost, A; Redon, N; Stezowski, O; Donadille, L; Dorvaux, O; Gall, B J P; Schulz, N; Lalkovski, S; Lucas, R; Minkova, A

2003-01-01

The sup 1 sup 1 sup 0 sup , sup 1 sup 1 sup 2 Rh and sup 1 sup 1 sup 4 sup , sup 1 sup 1 sup 6 Ag nuclei have been produced as fission fragments in the fusion reaction sup 1 sup 8 O+ sup 2 sup 0 sup 8 Pb at 85 MeV. Their level schemes have been built from gamma-rays detected using the Euroball IV array. High-spin states of these neutron-rich nuclei have been identified for the first time. The yrast structures consist of rotational bands in which the odd proton occupies the pi g sub 9 sub / sub 2 sub-shell and the odd neutron the nu h sub 1 sub 1 sub / sub 2 sub-shell. The evolution of the pi g sub 9 sub / sub 2 x nu h sub 1 sub 1 sub / sub 2 band structure is analyzed as a function of the neutron number.

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

Table of members of quasi-bands

International Nuclear Information System (INIS)

Sakai, Mitsuo.

1984-04-01

The probable members of the quasi-bands in even-even nuclei for Z between 6 and 100 are listed in this table. The terms quasi-bands have been introduced in the so-called spherical regions as the counter parts of the collective bands in the deformed regions. In the present compilation, the data for deformed nuclei are classified for convenience under the same titles, Quasi-Ground Band, Quasi-Beta Band and Quasi-Gamma Band, as are used for other nuclear regions. The present edition covers the literature through September, 1983. Fifteen newly discovered nuclides are included. The classification of energy level into quasi-bands is made on the basis of the systematic trend in the data over large groups of nuclei. (Kato, T.)

Band parameters of phosphorene

International Nuclear Information System (INIS)

Lew Yan Voon, L C; Wang, J; Zhang, Y; Willatzen, M

2015-01-01

Phosphorene is a two-dimensional nanomaterial with a direct band-gap at the Brillouin zone center. In this paper, we present a recently derived effective-mass theory of the band structure in the presence of strain and electric field, based upon group theory. Band parameters for this theory are computed using a first-principles theory based upon the generalized-gradient approximation to the density-functional theory. These parameters and Hamiltonian will be useful for modeling physical properties of phosphorene. (paper)

Amniotic constriction bands

Science.gov (United States)

... Supplements Videos & Tools Español You Are Here: Home → Medical Encyclopedia → Amniotic band sequence URL of this page: //medlineplus.gov/ency/ ... birth. The baby should be delivered in a medical center that has specialists experienced in caring for babies ... or partial loss of function of a body part. Congenital bands affecting large parts of the body cause the ...

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)

47 CFR 90.531 - Band plan.

Science.gov (United States)

2010-10-01

... 47 Telecommunication 5 2010-10-01 2010-10-01 false Band plan. 90.531 Section 90.531...-805 MHz Bands § 90.531 Band plan. This section sets forth the band plan for the 763-775 MHz and 793... and portables subject to Commission-approved regional planning committee regional plans. Transmitter...

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

Comparison of band-to-band tunneling models in Si and Si—Ge junctions

International Nuclear Information System (INIS)

Jiao Yipeng; Wang Taihuan; Wei Kangliang; Du Gang; Liu Xiaoyan

2013-01-01

We compared several different band-to-band tunneling (BTBT) models with both Sentaurus and the two-dimensional full-band Monte Carlo simulator in Si homo-junctions and Si—Ge hetero-junctions. It was shown that in Si homo-junctions, different models could achieve similar results. However, in the Si—Ge hetero-junctions, there were significant differences among these models at high reverse biases (over 2 V). Compared to the nonlocal model, the local models in Sentaurus underrated the BTBT rate distinctly, and the Monte Carlo method was shown to give a better approximation. Additionally, it was found that in the Si region near the interface of the Si—Ge hetero-junctions, the direct tunneling rates increased largely due to the interaction of the band structures of Si and Ge. (semiconductor physics)

Deep-Space Ka-Band Flight Experience

Science.gov (United States)

Morabito, D. D.

2017-11-01

Lower frequency bands have become more congested in allocated bandwidth as there is increased competition between flight projects and other entities. Going to higher frequency bands offers significantly more bandwidth, allowing for the use of much higher data rates. However, Ka-band is more susceptible to weather effects than lower frequency bands currently used for most standard downlink telemetry operations. Future or prospective flight projects considering deep-space Ka-band (32-GHz) telemetry data links have expressed an interest in understanding past flight experience with received Ka-band downlink performance. Especially important to these flight projects is gaining a better understanding of weather effects from the experience of current or past missions that operated Ka-band radio systems. We will discuss the historical flight experience of several Ka-band missions starting from Mars Observer in 1993 up to present-day deep-space missions such as Kepler. The study of historical Ka-band flight experience allows one to recommend margin policy for future missions. Of particular interest, we will review previously reported-on flight experience with the Cassini spacecraft Ka-band radio system that has been used for radio science investigations as well as engineering studies from 2004 to 2015, when Cassini was in orbit around the planet Saturn. In this article, we will focus primarily on the Kepler spacecraft Ka-band link, which has been used for operational telemetry downlink from an Earth trailing orbit where the spacecraft resides. We analyzed the received Ka-band signal level data in order to characterize link performance over a wide range of weather conditions and as a function of elevation angle. Based on this analysis of Kepler and Cassini flight data, we found that a 4-dB margin with respect to adverse conditions ensures that we achieve at least a 95 percent data return.

Elastic band prediction equations for combined free-weight and elastic band bench presses and squats.

Science.gov (United States)

Shoepe, Todd C; Ramirez, David A; Almstedt, Hawley C

2010-01-01

Elastic bands added to traditional free-weight techniques have become a part of suggested training routines in recent years. Because of the variable loading patterns of elastic bands (i.e., greater stretch produces greater resistance), it is necessary to quantify the exact loading patterns of bands to identify the volume and intensity of training. The purpose of this study was to determine the length vs. tension properties of multiple sizes of a set of commonly used elastic bands to quantify the resistance that would be applied to free-weight plus elastic bench presses (BP) and squats (SQ). Five elastic bands of varying thickness were affixed to an overhead support beam. Dumbbells of varying weights were progressively added to the free end while the linear deformation was recorded with each subsequent weight increment. The resistance was plotted as a factor of linear deformation, and best-fit nonlinear logarithmic regression equations were then matched to the data. For both the BP and SQ loading conditions and all band thicknesses tested, R values were greater than 0.9623. These data suggest that differences in load exist as a result of the thickness of the elastic band, attachment technique, and type of exercise being performed. Facilities should adopt their own form of loading quantification to match their unique set of circumstances when acquiring, researching, and implementing elastic band and free-weight exercises into the training programs.

Solid State KA-Band, Solid State W-Band and TWT Amplifiers, Phase I

Data.gov (United States)

National Aeronautics and Space Administration — Phase I of the proposal describes plans to develop a state of the art transmitter for the W-Band and KA -Band Cloud Radar system. Our focus will be concentrated in...

The dynamics of a shear band

Science.gov (United States)

Giarola, Diana; Capuani, Domenico; Bigoni, Davide

2018-03-01

A shear band of finite length, formed inside a ductile material at a certain stage of a continued homogeneous strain, provides a dynamic perturbation to an incident wave field, which strongly influences the dynamics of the material and affects its path to failure. The investigation of this perturbation is presented for a ductile metal, with reference to the incremental mechanics of a material obeying the J2-deformation theory of plasticity (a special form of prestressed, elastic, anisotropic, and incompressible solid). The treatment originates from the derivation of integral representations relating the incremental mechanical fields at every point of the medium to the incremental displacement jump across the shear band faces, generated by an impinging wave. The boundary integral equations (under the plane strain assumption) are numerically approached through a collocation technique, which keeps into account the singularity at the shear band tips and permits the analysis of an incident wave impinging a shear band. It is shown that the presence of the shear band induces a resonance, visible in the incremental displacement field and in the stress intensity factor at the shear band tips, which promotes shear band growth. Moreover, the waves scattered by the shear band are shown to generate a fine texture of vibrations, parallel to the shear band line and propagating at a long distance from it, but leaving a sort of conical shadow zone, which emanates from the tips of the shear band.

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.

Dust bands in the asteroid belt

International Nuclear Information System (INIS)

Sykes, M.V.; Greenberg, R.; Dermott, S.F.; Nicholson, P.D.; Burns, J.A.

1989-01-01

This paper describes the original IRAS observations leading to the discovery of the three dust bands in the asteroid belt and the analysis of data. Special attention is given to an analytical model of the dust band torus and to theories concerning the origin of the dust bands, with special attention given to the collisional equilibrium (asteroid family), the nonequilibrium (random collision), and the comet hypotheses of dust-band origin. It is noted that neither the equilibrium nor nonequilibrium models, as currently formulated, present a complete picture of the IRAS dust-band observations. 32 refs

Thematic mapper studies band correlation analysis

Science.gov (United States)

Ungar, S. G.; Kiang, R.

1976-01-01

Spectral data representative of thematic mapper candidate bands 1 and 3 to 7 were obtained by selecting appropriate combinations of bands from the JSC 24 channel multispectral scanner. Of all the bands assigned, only candidate bands 4 (.74 mu to .80 mu) and 5 (.80 mu to .91 mu) showed consistently high intercorrelation from region to region and time to time. This extremely high correlation persisted when looking at the composite data set in a multitemporal, multilocation domain. The GISS investigations lend positive confirmation to the hypothesis, that TM bands 4 and 5 are redundant.

Modeling direct band-to-band tunneling: From bulk to quantum-confined semiconductor devices

Science.gov (United States)

Carrillo-Nuñez, H.; Ziegler, A.; Luisier, M.; Schenk, A.

2015-06-01

A rigorous framework to study direct band-to-band tunneling (BTBT) in homo- and hetero-junction semiconductor nanodevices is introduced. An interaction Hamiltonian coupling conduction and valence bands (CVBs) is derived using a multiband envelope method. A general form of the BTBT probability is then obtained from the linear response to the "CVBs interaction" that drives the system out of equilibrium. Simple expressions in terms of the one-electron spectral function are developed to compute the BTBT current in two- and three-dimensional semiconductor structures. Additionally, a two-band envelope equation based on the Flietner model of imaginary dispersion is proposed for the same purpose. In order to characterize their accuracy and differences, both approaches are compared with full-band, atomistic quantum transport simulations of Ge, InAs, and InAs-Si Esaki diodes. As another numerical application, the BTBT current in InAs-Si nanowire tunnel field-effect transistors is computed. It is found that both approaches agree with high accuracy. The first one is considerably easier to conceive and could be implemented straightforwardly in existing quantum transport tools based on the effective mass approximation to account for BTBT in nanodevices.

Modeling direct band-to-band tunneling: From bulk to quantum-confined semiconductor devices

International Nuclear Information System (INIS)

Carrillo-Nuñez, H.; Ziegler, A.; Luisier, M.; Schenk, A.

2015-01-01

A rigorous framework to study direct band-to-band tunneling (BTBT) in homo- and hetero-junction semiconductor nanodevices is introduced. An interaction Hamiltonian coupling conduction and valence bands (CVBs) is derived using a multiband envelope method. A general form of the BTBT probability is then obtained from the linear response to the “CVBs interaction” that drives the system out of equilibrium. Simple expressions in terms of the one-electron spectral function are developed to compute the BTBT current in two- and three-dimensional semiconductor structures. Additionally, a two-band envelope equation based on the Flietner model of imaginary dispersion is proposed for the same purpose. In order to characterize their accuracy and differences, both approaches are compared with full-band, atomistic quantum transport simulations of Ge, InAs, and InAs-Si Esaki diodes. As another numerical application, the BTBT current in InAs-Si nanowire tunnel field-effect transistors is computed. It is found that both approaches agree with high accuracy. The first one is considerably easier to conceive and could be implemented straightforwardly in existing quantum transport tools based on the effective mass approximation to account for BTBT in nanodevices

Modeling direct band-to-band tunneling: From bulk to quantum-confined semiconductor devices

Energy Technology Data Exchange (ETDEWEB)

Carrillo-Nuñez, H.; Ziegler, A.; Luisier, M.; Schenk, A. [Integrated Systems Laboratory ETH Zürich, Gloriastrasse 35, 8092 Zürich (Switzerland)

2015-06-21

A rigorous framework to study direct band-to-band tunneling (BTBT) in homo- and hetero-junction semiconductor nanodevices is introduced. An interaction Hamiltonian coupling conduction and valence bands (CVBs) is derived using a multiband envelope method. A general form of the BTBT probability is then obtained from the linear response to the “CVBs interaction” that drives the system out of equilibrium. Simple expressions in terms of the one-electron spectral function are developed to compute the BTBT current in two- and three-dimensional semiconductor structures. Additionally, a two-band envelope equation based on the Flietner model of imaginary dispersion is proposed for the same purpose. In order to characterize their accuracy and differences, both approaches are compared with full-band, atomistic quantum transport simulations of Ge, InAs, and InAs-Si Esaki diodes. As another numerical application, the BTBT current in InAs-Si nanowire tunnel field-effect transistors is computed. It is found that both approaches agree with high accuracy. The first one is considerably easier to conceive and could be implemented straightforwardly in existing quantum transport tools based on the effective mass approximation to account for BTBT in nanodevices.

Band-to-Band Misregistration of the Images of MODIS Onboard Calibrators and Its Impact on Calibration

Science.gov (United States)

Wang, Zhipeng; Xiong, Xiaoxiong

2017-01-01

The Moderate Resolution Imaging Spectroradiometer (MODIS) instruments aboard Terra and Aqua satellites are radiometrically calibrated on-orbit with a set of onboard calibrators (OBCs), including a solar diffuser, a blackbody, and a space view port through which the detectors can view the dark space. As a whisk-broom scanning spectroradiometer, thirty-six MODIS spectral bands are assembled in the along-scan direction on four focal plane assemblies (FPAs). These bands capture images of the same target sequentially with the motion of a scan mirror. Then the images are coregistered onboard by delaying the appropriate band-dependent amount of time, depending on the band locations on the FPA. While this coregistration mechanismis functioning well for the far-field remote targets such as earth view scenes or the moon, noticeable band-to-band misregistration in the along-scan direction has been observed for near field targets, particularly in OBCs. In this paper, the misregistration phenomenon is presented and analyzed. It is concluded that the root cause of the misregistration is that the rotating element of the instrument, the scan mirror, is displaced from the focus of the telescope primary mirror. The amount of the misregistrationis proportional to the band location on the FPA and is inversely proportional to the distance between the target and the scan mirror. The impact of this misregistration on the calibration of MODIS bands is discussed. In particular, the calculation of the detector gain coefficient m1of bands 8-16 (412 nm 870 nm) is improved by up to 1.5% for Aqua MODIS.

Infrared diffuse interstellar bands

Science.gov (United States)

Galazutdinov, G. A.; Lee, Jae-Joon; Han, Inwoo; Lee, Byeong-Cheol; Valyavin, G.; Krełowski, J.

2017-05-01

We present high-resolution (R ˜ 45 000) profiles of 14 diffuse interstellar bands in the ˜1.45 to ˜2.45 μm range based on spectra obtained with the Immersion Grating INfrared Spectrograph at the McDonald Observatory. The revised list of diffuse bands with accurately estimated rest wavelengths includes six new features. The diffuse band at 15 268.2 Å demonstrates a very symmetric profile shape and thus can serve as a reference for finding the 'interstellar correction' to the rest wavelength frame in the H range, which suffers from a lack of known atomic/molecular lines.

Analysis of optical band-gap shift in impurity doped ZnO thin films by using nonparabolic conduction band parameters

International Nuclear Information System (INIS)

Kim, Won Mok; Kim, Jin Soo; Jeong, Jeung-hyun; Park, Jong-Keuk; Baik, Young-Jun; Seong, Tae-Yeon

2013-01-01

Polycrystalline ZnO thin films both undoped and doped with various types of impurities, which covered the wide carrier concentration range of 10 16 –10 21 cm −3 , were prepared by magnetron sputtering, and their optical-band gaps were investigated. The experimentally measured optical band-gap shifts were analyzed by taking into account the carrier density dependent effective mass determined by the first-order nonparabolicity approximation. It was shown that the measured shifts in optical band-gaps in ZnO films doped with cationic dopants, which mainly perturb the conduction band, could be well represented by theoretical estimation in which the band-gap widening due to the band-filling effect and the band-gap renormalization due to the many-body effect derived for a weakly interacting electron-gas model were combined and the carrier density dependent effective mass was incorporated. - Highlights: ► Optical band-gaps of polycrystalline ZnO thin films were analyzed. ► Experimental carrier concentration range covered from 10 16 to 10 21 cm −3 . ► Nonparabolic conduction band parameters were used in theoretical analysis. ► The band-filling and the band-gap renormalization effects were considered. ► The measured optical band-gap shifts corresponded well with the calculated ones

Modelling band-to-band tunneling current in InP-based heterostructure photonic devices

NARCIS (Netherlands)

van Engelen, J.P.; Shen, L.; van der Tol, J.J.G.M.; Smit, M.K.; Kockaert, P.; Emplit, P.; Gorza, S.-P.; Massar, S.

2015-01-01

Some semiconductor photonic devices show large discontinuities in the band structure. Short tunnel paths caused by this band structure may lead to an excessive tunneling current, especially in highly doped layers. Modelling of this tunnelling current is therefore important when designing photonic

Change in optimum genetic algorithm solution with changing band discontinuities and band widths of electrically conducting copolymers

Science.gov (United States)

Kaur, Avneet; Bakhshi, A. K.

2010-04-01

The interest in copolymers stems from the fact that they present interesting electronic and optical properties leading to a variety of technological applications. In order to get a suitable copolymer for a specific application, genetic algorithm (GA) along with negative factor counting (NFC) method has recently been used. In this paper, we study the effect of change in the ratio of conduction band discontinuity to valence band discontinuity (Δ Ec/Δ Ev) on the optimum solution obtained from GA for model binary copolymers. The effect of varying bandwidths on the optimum GA solution is also investigated. The obtained results show that the optimum solution changes with varying parameters like band discontinuity and band width of constituent homopolymers. As the ratio Δ Ec/Δ Ev increases, band gap of optimum solution decreases. With increasing band widths of constituent homopolymers, the optimum solution tends to be dependent on the component with higher band gap.

Band connectivity for topological quantum chemistry: Band structures as a graph theory problem

Science.gov (United States)

Bradlyn, Barry; Elcoro, L.; Vergniory, M. G.; Cano, Jennifer; Wang, Zhijun; Felser, C.; Aroyo, M. I.; Bernevig, B. Andrei

2018-01-01

The conventional theory of solids is well suited to describing band structures locally near isolated points in momentum space, but struggles to capture the full, global picture necessary for understanding topological phenomena. In part of a recent paper [B. Bradlyn et al., Nature (London) 547, 298 (2017), 10.1038/nature23268], we have introduced the way to overcome this difficulty by formulating the problem of sewing together many disconnected local k .p band structures across the Brillouin zone in terms of graph theory. In this paper, we give the details of our full theoretical construction. We show that crystal symmetries strongly constrain the allowed connectivities of energy bands, and we employ graph theoretic techniques such as graph connectivity to enumerate all the solutions to these constraints. The tools of graph theory allow us to identify disconnected groups of bands in these solutions, and so identify topologically distinct insulating phases.

Wide Band to ''Double Band'' upgrade

International Nuclear Information System (INIS)

Kasper, P.; Currier, R.; Garbincius, P.; Butler, J.

1988-06-01

The Wide Band beam currently uses electrons obtained from secondary photon conversions to produce the photon beam incident on the experimental targets. By transporting the positrons produced in these conversions as well as the electrons it is possible to almost double the number of photons delivered to the experiments per primary beam proton. 11 figs

Thermal evolution of the band edges of 6H-SiC: X-ray methods compared to the optical band gap

International Nuclear Information System (INIS)

Miedema, P.S.; Beye, M.; Könnecke, R.; Schiwietz, G.; Föhlisch, A.

2014-01-01

Highlights: • Conduction band minima (CBM) of 6H-SiC are estimated with Si 2p XAS. • Valence band maxima (VBM) of 6H-SiC are estimated with non-resonant Si 2p XES. • Temperature-dependent VBM and CBM of 6H-SiC show asymmetric band gap closing. • XAS, XES and RIXS band gap estimates are compared with the optical band gap. • XAS + XES versus optical band gap provides core-excitonic screening energies. - Abstract: The band gap of semiconductors like silicon and silicon carbide (SiC) is the key for their device properties. In this research, the band gap of 6H-SiC and its temperature dependence were analyzed with silicon 2p X-ray absorption spectroscopy (XAS), X-ray emission spectroscopy (XES) and resonant inelastic X-ray scattering (RIXS) allowing for a separate analysis of the conduction-band minimum (CBM) and valence-band maximum (VBM) components of the band gap. The temperature-dependent asymmetric band gap shrinking of 6H-SiC was determined with a valence-band slope of +2.45 × 10 −4 eV/K and a conduction-band slope of −1.334 × 10 −4 eV/K. The apparent asymmetry, e.g., that two thirds of the band-gap shrinking with increasing temperature is due to the VBM evolution in 6H-SiC, is similar to the asymmetry obtained for pure silicon before. The overall band gap temperature-dependence determined with XAS and non-resonant XES is compared to temperature-dependent optical studies. The core-excitonic binding energy appearing in the Si 2p XAS is extracted as the main difference. In addition, the energy loss of the onset of the first band in RIXS yields to values similar to the optical band gap over the tested temperature range

UWB Filtering Power Divider with Two Narrow Notch-bands and Wide Stop-band

Science.gov (United States)

Wei, Feng; Wang, Xin-Yi; Zou, Xin Tong; Shi, Xiao Wei

2017-12-01

A compact filtering ultra-wideband (UWB) microstrip power divider (PD) with two sharply rejected notch-bands and wide stopband is analyzed and designed in this paper. The proposed UWB PD is based on a conventional Wilkinson power divider, while two stub loaded resonators (SLRs) are coupled into two symmetrical output ports to achieve a bandpass filtering response. The simplified composite right/left-handed (SCRLH) resonators are employed to generate the dual notched bands. Defected ground structure (DGS) is introduced to improve the passband performance. Good insertion/return losses, isolation and notch-band rejection are achieved as demonstrated in both simulation and experiment.

Band-type microelectrodes for amperometric immunoassays

Energy Technology Data Exchange (ETDEWEB)

Lee, Ga-Yeon; Chang, Young Wook; Ko, Hyuk [Department of Materials Science and Engineering, Yonsei University, 134 Shinchon-dong, Seodaemun-gu, Seoul, 120-749 (Korea, Republic of); Kang, Min-Jung [Korea Institute of Science and Technology (KIST), Seoul (Korea, Republic of); Pyun, Jae-Chul, E-mail: jcpyun@yonsei.ac.kr [Department of Materials Science and Engineering, Yonsei University, 134 Shinchon-dong, Seodaemun-gu, Seoul, 120-749 (Korea, Republic of)

2016-07-20

A band-type microelectrode was made using a parylene-N film as a passivation layer. A circular-type, mm-scale electrode with the same diameter as the band-type microelectrode was also made with an electrode area that was 5000 times larger than the band-type microelectrode. By comparing the amperometric signals of 3,5,3′,5′-tetramethylbenzidine (TMB) samples at different optical density (OD) values, the band-type microelectrode was determined to be 9 times more sensitive than the circular-type electrode. The properties of the circular-type and the band-type electrodes (e.g., the shape of their cyclic voltammograms, the type of diffusion layer used, and the diffusion layer thickness per unit electrode area) were characterized according to their electrode area using the COMSOL Multiphysics software. From these simulations, the band-type electrode was estimated to have the conventional microelectrode properties, even when the electrode area was 100 times larger than a conventional circular-type electrode. These results show that both the geometry and the area of an electrode can influence the properties of the electrode. Finally, amperometric analysis based on a band-type electrode was applied to commercial ELISA kits to analyze human hepatitis B surface antigen (hHBsAg) and human immunodeficiency virus (HIV) antibodies. - Highlights: • A band-type microelectrode was made using a parylene-N film as a passivation layer. • The band-type microelectrode was 14-times more sensitive than circular-type electrode. • The influence of geometry on microelectrode properties was simulated using COMSOL. • The band-type electrode was applied to ELISA kits for hHBsAg and hHIV-antibodies.

Convex Banding of the Covariance Matrix.

Science.gov (United States)

Bien, Jacob; Bunea, Florentina; Xiao, Luo

2016-01-01

We introduce a new sparse estimator of the covariance matrix for high-dimensional models in which the variables have a known ordering. Our estimator, which is the solution to a convex optimization problem, is equivalently expressed as an estimator which tapers the sample covariance matrix by a Toeplitz, sparsely-banded, data-adaptive matrix. As a result of this adaptivity, the convex banding estimator enjoys theoretical optimality properties not attained by previous banding or tapered estimators. In particular, our convex banding estimator is minimax rate adaptive in Frobenius and operator norms, up to log factors, over commonly-studied classes of covariance matrices, and over more general classes. Furthermore, it correctly recovers the bandwidth when the true covariance is exactly banded. Our convex formulation admits a simple and efficient algorithm. Empirical studies demonstrate its practical effectiveness and illustrate that our exactly-banded estimator works well even when the true covariance matrix is only close to a banded matrix, confirming our theoretical results. Our method compares favorably with all existing methods, in terms of accuracy and speed. We illustrate the practical merits of the convex banding estimator by showing that it can be used to improve the performance of discriminant analysis for classifying sound recordings.

Band-to-band transitions, selection rules, effective mass, and excitonic contributions in monoclinic β -Ga2O3

Science.gov (United States)

Mock, Alyssa; Korlacki, Rafał; Briley, Chad; Darakchieva, Vanya; Monemar, Bo; Kumagai, Yoshinao; Goto, Ken; Higashiwaki, Masataka; Schubert, Mathias

2017-12-01

We employ an eigenpolarization model including the description of direction dependent excitonic effects for rendering critical point structures within the dielectric function tensor of monoclinic β -Ga2O3 yielding a comprehensive analysis of generalized ellipsometry data obtained from 0.75-9 eV. The eigenpolarization model permits complete description of the dielectric response. We obtain, for single-electron and excitonic band-to-band transitions, anisotropic critical point model parameters including their polarization vectors within the monoclinic lattice. We compare our experimental analysis with results from density functional theory calculations performed using the Gaussian-attenuation-Perdew-Burke-Ernzerhof hybrid density functional. We present and discuss the order of the fundamental direct band-to-band transitions and their polarization selection rules, the electron and hole effective mass parameters for the three lowest band-to-band transitions, and their excitonic contributions. We find that the effective masses for holes are highly anisotropic and correlate with the selection rules for the fundamental band-to-band transitions. The observed transitions are polarized close to the direction of the lowest hole effective mass for the valence band participating in the transition.

Intruder bands in Z = 51 nuclei

International Nuclear Information System (INIS)

LaFosse, D.R.

1993-01-01

Recent investigations of h 11/2 proton intruder bands in odd 51 Sb nuclei are reported. In addition to experiments performed at SUNY Stony Brook and Chalk River, data from Early Implementation of GAMMASPHERE (analysis in progress) are presented. In particular, the nuclei 109 Sb and 111 Sb are discussed. Rotational bands based on the πh 11/2 orbital coupled to a 2p2h deformed state of the 50 Sn core have been observed. These bands have been observed to high spin, and in the case of 109 Sb to a rotational frequency of 1.4 MeV, the highest frequency observed in a heavy nucleus. The dynamic moments of inertia in these bands decrease slowly with frequency, suggesting a gradual band termination. The systematics of such bands in 109-119 Sb will be discussed

Band 3 in aging and neurological disease.

Science.gov (United States)

Kay, M M

1991-01-01

Senescent cell antigen appears on old cells and marks them for death by initiating the binding of IgG autoantibody and subsequent removal by phagocytes in mammals and other vertebrates. We have created a synthetic aging antigen that blocks binding of IgG to senescent cells in vitro. Synthetic senescent cell antigen might be effective in preventing cellular destruction in vivo in certain diseases, and can be used to manipulate cellular life span in situ. Senescent cell antigen is generated by the modification of an important structural and transport membrane molecule, protein band 3. Band 3 is present in cellular, nuclear, Golgi, and mitochondrial membranes as well as in cell membranes. Band 3 proteins in nucleated cells participate in cell surface patching and capping. Band 3 maintains acid-base balance by mediating the exchange of anions (e.g., chloride, bicarbonate), and is the binding site for glycolytic enzymes. It is responsible for CO2 exchange in all tissues and organs. Thus, it is the most heavily used anion transport system in the body. Band 3 is a major transmembrane structural protein which attaches the plasma membrane to the internal cell cytoskeleton by binding to band 2.1 (ankyrin). Oxidation generates senescent cell antigen in situ. Band 3 is present in the central nervous system, and differences have been described in band 3 between young and aging brain tissue. One autosomal recessive neurological disease, choreoacanthocytosis, is associated with band 3 abnormalities. The 150 residues of the carboxyl terminus segment of band 3 appear to be altered. In brains from Alzheimer's disease patients, antibodies to aged band 3 label the amyloid core of classical plaques and the microglial cells located in the middle of the plaque in tissue sections, and an abnormal band 3 in immunoblots. Band 3 protein(s) in mammalian brain performs the same functions as that of erythroid band 3. These functions is anion transport, ankyrin binding, and generation of

Evolution of triaxial shapes at large isospin: Rh isotopes

Directory of Open Access Journals (Sweden)

A. Navin

2017-04-01

Full Text Available The rotational response as a function of neutron–proton asymmetry for the very neutron-rich isotopes of Rh (116–119Rh has been obtained from the measurement of prompt γ rays from isotopically identified fragments, produced in fission reactions at energies around the Coulomb barrier. The measured energy “signature” splitting of the yrast bands, when compared with the Triaxial Projected Shell Model (TPSM calculations, shows the need for large, nearly constant, triaxial deformations. The present results are compared with global predictions for the existence of non axial shapes in the periodic table in the case of very neutron-rich nuclei Rh isotopes. The predicted trend of a second local maximum for a triaxial shape around N∼74 is not found.

182Pt as a possible candidate for X(5) symmetry

International Nuclear Information System (INIS)

Petkov, P; Gladnsihki, K A; Dewald, A; Fransen, C; Hackstein, M; Jolie, J; Pissulla, Th; Rother, W; Zell, K O

2012-01-01

Recently, a new island of X(5) nuclei has been suggested around A=180 exemplified by some Osmium isotopes. To investigate the limits of its region, a Recoil-distance Doppler shift lifetime measurement has been performed for 182 Pt. For the data analysis, the Differential decay curve method has been applied in a newly developed version convenient for low recoil velocities and a non-negligible fraction of nuclei stopped already in the target. The level energies and the newly deduced transition quadrupole moments in the yrast band reveal the persistence of X(5) features in the investigated nucleus, but other spectroscopic data and IBM and GCM calculations indicate shape coexistence and a position of 182 Pt close but not at the critical point of the shape-transition.

Enhancement of computer program SPECTRAN to provide optional synthesis of 1/12 octave-band and critical-band spectra from 1/3 octave-band spectra

Energy Technology Data Exchange (ETDEWEB)

Chang, Young-Soo [Argonne National Lab., IL (United States); Liebich, R.E. [Raytheon Environmental Services Company, Cambridge, MA (United States)

1997-07-01

This paper describes greatly enhanced version of the computer program SPECTRAN, which was initially presented in Paper No. 96-RA104.01, at the A&WMA 89th Annual Meeting in June 1996. The program has had three basic upgrades since that time. The first is provision of an option to use either batch-mode input from previously prepared data files or a {open_quotes}user-friendly{close_quotes} interactive input routine. The latter is primarily for first-time users and those having only one, or very few, spectra to process. The second improvement is the synthesis of 1/12 octave-band spectra from 1/3 octave-band spectra, with {open_quotes}tone correction,{close_quotes} in a manner similar to that used in the original version of the program. The third fundamental improvement is addition of a unique new capability to synthesize classic {open_quotes}critical-band{close_quotes} spectra from 1/3 octave-band input spectra. Critical-band spectra are also termed {open_quotes}equivalent-rectangular-bandwidth (ERB){close_quotes} and {open_quotes}equal-contribution-to-speech (ECS){close_quotes} spectra.

Band Subset Selection for Hyperspectral Image Classification

Directory of Open Access Journals (Sweden)

Chunyan Yu

2018-01-01

Full Text Available This paper develops a new approach to band subset selection (BSS for hyperspectral image classification (HSIC which selects multiple bands simultaneously as a band subset, referred to as simultaneous multiple band selection (SMMBS, rather than one band at a time sequentially, referred to as sequential multiple band selection (SQMBS, as most traditional band selection methods do. In doing so, a criterion is particularly developed for BSS that can be used for HSIC. It is a linearly constrained minimum variance (LCMV derived from adaptive beamforming in array signal processing which can be used to model misclassification errors as the minimum variance. To avoid an exhaustive search for all possible band subsets, two numerical algorithms, referred to as sequential (SQ and successive (SC algorithms are also developed for LCMV-based SMMBS, called SQ LCMV-BSS and SC LCMV-BSS. Experimental results demonstrate that LCMV-based BSS has advantages over SQMBS.

The Low Band Observatory (LOBO): Expanding the VLA Low Frequency Commensal System for Continuous, Broad-band, sub-GHz Observations

Science.gov (United States)

Kassim, Namir E.; Clarke, Tracy E.; Helmboldt, Joseph F.; Peters, Wendy M.; Brisken, Walter; Hyman, Scott D.; Polisensky, Emil; Hicks, Brian

2015-01-01

The Naval Research Laboratory (NRL) and the National Radio Astronomy Observatory (NRAO) are currently commissioning the VLA Low Frequency Ionosphere and Transient Experiment (VLITE) on a subset of JVLA antennas at modest bandwidth. Its bounded scientific goals are to leverage thousands of JVLA on-sky hours per year for ionospheric and transient studies, and to demonstrate the practicality of a prime-focus commensal system on the JVLA. Here we explore the natural expansion of VLITE to a full-antenna, full-bandwidth Low Band Observatory (LOBO) that would follow naturally from a successful VLITE experience. The new Low Band JVLA receivers, coupled with the existing primary focus feeds, can access two frequency bands: 4 band (54 - 86 MHz) and P band (236-492 MHz). The 4 band feeds are newly designed and now undergoing testing. If they prove successful then they can be permanently mounted at the primary focus, unlike their narrow band predecessors. The combination of Low Band receivers and fixed, primary-focus feeds could provide continuous, broad-band data over two complimentary low-frequency bands. The system would also leverage the relatively large fields-of-view of ~10 degrees at 4 band, and ~2.5 degrees at P band, coupling an excellent survey capability with a natural advantage for serendipitous discoveries. We discuss the compelling science case that flows from LOBO's robust imaging and time domain capabilities coupled with thousands of hours of wide-field, JVLA observing time each year. We also touch on the possibility to incorporate Long Wavelength Array (LWA) stations as additional 'dishes' through the LOBO backend, to improve calibration and sensitivity in LOBO's 4 band.

Decreasing patient identification band errors by standardizing processes.

Science.gov (United States)

Walley, Susan Chu; Berger, Stephanie; Harris, Yolanda; Gallizzi, Gina; Hayes, Leslie

2013-04-01

Patient identification (ID) bands are an essential component in patient ID. Quality improvement methodology has been applied as a model to reduce ID band errors although previous studies have not addressed standardization of ID bands. Our specific aim was to decrease ID band errors by 50% in a 12-month period. The Six Sigma DMAIC (define, measure, analyze, improve, and control) quality improvement model was the framework for this study. ID bands at a tertiary care pediatric hospital were audited from January 2011 to January 2012 with continued audits to June 2012 to confirm the new process was in control. After analysis, the major improvement strategy implemented was standardization of styles of ID bands and labels. Additional interventions included educational initiatives regarding the new ID band processes and disseminating institutional and nursing unit data. A total of 4556 ID bands were audited with a preimprovement ID band error average rate of 9.2%. Significant variation in the ID band process was observed, including styles of ID bands. Interventions were focused on standardization of the ID band and labels. The ID band error rate improved to 5.2% in 9 months (95% confidence interval: 2.5-5.5; P error rates. This decrease in ID band error rates was maintained over the subsequent 8 months.

Interpolation of band-limited discrete-time signals by minimising out-of-band energy

NARCIS (Netherlands)

Janssen, A.J.E.M.; Vries, L.B.

1984-01-01

An interpolation method for restoring burst errors in discrete—time, band—limited signals is presented. The restoration is such that the restored signal has minimal out—of—band energy. The filter coefficients depend Only on the burst length and on the size of the band to which the signal is assumed

Band-gap and band-edge engineering of multicomponent garnet scintillators from first principles

Czech Academy of Sciences Publication Activity Database

Yadav, S.K.; Uberuaga, B.P.; Nikl, Martin; Jiang, C.; Stanek, C.R.

2015-01-01

Roč. 4, č. 5 (2015), "054012-1"-"054012-9" ISSN 2331-7019 R&D Projects: GA ČR GAP204/12/0805 Institutional support: RVO:68378271 Keywords : scintillator * electronic band gap structure * garnets * band gap engineering Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 4.061, year: 2015

Treatment of Patellar Lower Pole Fracture with Modified Titanium Cable Tension Band Plus Patellar Tibial Tunnel Steel "8" Reduction Band.

Science.gov (United States)

Li, Jiaming; Wang, Decheng; He, Zhiliang; Shi, Hao

2018-01-08

To determine the efficacy of modified titanium tension band plus patellar tendon tunnel steel 8 "reduction band" versus titanium cable tension band fixation for the treatment of patellar lower pole fracture. 58 patients with lower patella fracture were enrolled in this study, including 30 patients treated with modified titanium cable tension band plus patellar tibial tunnel wire "8" tension band internal fixation (modified group), and 28 patients with titanium cable tension band fixation. All patients were followed up for 9∼15 months with an average of 11.6 months. Knee flexion was significantly improved in the modified group than in the titanium cable tension band group (111.33 ± 13 degrees versus 98.21 ± 21.70 degrees, P = 0.004). The fracture healing time showed no significant difference. At the end of the follow-up, the improvement excellent rate was 93.33% in the modified group, and 82.14% in the titanium cable tension band group. Titanium cable tension band internal fixation loosening was found in 2 cases, including 1 case of treatment by two surgeries without loose internal fixation. The modified titanium cable tension band with "8" tension band fixation showed better efficacy for lower patella fractures than titanium cable tension band fixation.

A UWB Band-Pass Antenna with Triple-Notched Band Using Common Direction Rectangular Complementary Split-Ring Resonators

Directory of Open Access Journals (Sweden)

Bo Yan

2013-01-01

Full Text Available A novel ultrawideband (UWB antenna which has a triple-band notch function is presented. The proposed antenna can block interfering signals from C-band satellite communication systems, IEEE802.11a, and HIPERLAN/2 WLAN systems for example. The antenna is excited by using novel common direction rectangular complementary split-ring resonators (CSRR fabricated on radiating patch of the dielectric substrate with coplanar waveguide (CPW feed strip line. The voltage standing wave ratio (VSWR of the proposed antenna is less than 2.0 in the frequency band from 2.8 to 12 GHz, while showing a very sharp band-rejection performance at 3.9 GHz, 5.2 GHz, and 5.9 GHz. The measurement results show that the proposed antenna provides good omnidirectional field pattern over its whole frequency band excluding the rejected band, which is suitable for UWB applications.

Band-to-Band Misregistration of the Images of MODIS On-Board Calibrators and Its Impact to Calibration

Science.gov (United States)

Wang, Zhipeng; Xiong, Xiaoxiong

2017-01-01

The MODIS instruments aboard Terra and Aqua satellites are radiometrically calibrated on-orbit with a set of onboard calibrators (OBC) including a solar diffuser (SD), a blackbody (BB) and a space view (SV) port through which the detectors can view the dark space. As a whisk-broom scanning spectroradiometer, thirty-six MODIS spectral bands are assembled in the along-scan direction on four focal plane assemblies (FPA). These bands capture images of the same target sequentially with the motion of a scan mirror. Then the images are co-registered on board by delaying appropriate band dependent amount of time depending on the band locations on the FPA. While this co-registration mechanism is functioning well for the "far field" remote targets such as Earth view (EV) scenes or the Moon, noticeable band-to-band misregistration in the along-scan direction has been observed for near field targets, in particular the OBCs. In this paper, the misregistration phenomenon is presented and analyzed. It is concluded that the root cause of the misregistration is that the rotating element of the instrument, the scan mirror, is displaced from the focus of the telescope primary mirror. The amount of the misregistration is proportional to the band location on the FPA and is inversely proportional to the distance between the target and the scan mirror. The impact of this misregistration to the calibration of MODIS bands is discussed. In particular, the calculation of the detector gain coefficient m1 of bands 8-16 (412 nm 870 nm) is improved by up to 1.5% for Aqua MODIS.

47 CFR 15.713 - TV bands database.

Science.gov (United States)

2010-10-01

... 47 Telecommunication 1 2010-10-01 2010-10-01 false TV bands database. 15.713 Section 15.713... TV bands database. (a) Purpose. The TV bands database serves the following functions: (1) To... databases. (b) Information in the TV bands database. (1) Facilities already recorded in Commission databases...

X-Band CubeSat Communication System Demonstration

Science.gov (United States)

Altunc, Serhat; Kegege, Obadiah; Bundick, Steve; Shaw, Harry; Schaire, Scott; Bussey, George; Crum, Gary; Burke, Jacob C.; Palo, Scott; O'Conor, Darren

2015-01-01

Today's CubeSats mostly operate their communications at UHF- and S-band frequencies. UHF band is presently crowded, thus downlink communications are at lower data rates due to bandwidth limitations and are unreliable due to interference. This research presents an end-to-end robust, innovative, compact, efficient and low cost S-band uplink and X-band downlink CubeSat communication system demonstration between a balloon and a Near Earth Network (NEN) ground system. Since communication systems serve as umbilical cords for space missions, demonstration of this X-band communication system is critical for successfully supporting current and future CubeSat communication needs. This research has three main objectives. The first objective is to design, simulate, and test a CubeSat S- and X-band communication system. Satellite Tool Kit (STK) dynamic link budget calculations and HFSS Simulations and modeling results have been used to trade the merit of various designs for small satellite applications. S- and X-band antennas have been tested in the compact antenna test range at Goddard Space Flight Center (GSFC) to gather radiation pattern data. The second objective is simulate and test a CubeSat compatible X-band communication system at 12.5Mbps including S-band antennas, X-band antennas, Laboratory for Atmospheric and Space Physics (LASP) /GSFC transmitter and an S-band receiver from TRL-5 to TRL-8 by the end of this effort. Different X-band communication system components (antennas, diplexers, etc.) from GSFC, other NASA centers, universities, and private companies have been investigated and traded, and a complete component list for the communication system baseline has been developed by performing analytical and numerical analysis. This objective also includes running simulations and performing trades between different X-band antenna systems to optimize communication system performance. The final objective is to perform an end-to-end X-band CubeSat communication system

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...

Construct and Concurrent Validation of a New Resistance Intensity Scale for Exercise with Thera-Band® Elastic Bands

Directory of Open Access Journals (Sweden)

Juan C. Colado, Xavier Garcia-Masso, N. Travis Triplett, Joaquin Calatayud, Jorge Flandez, David Behm, Michael E. Rogers

2014-12-01

Full Text Available The construct and concurrent validity of the Thera-Band Perceived Exertion Scale for Resistance Exercise with elastic bands (EB was examined. Twenty subjects performed two separate sets of 15 repetitions of both frontal and lateral raise exercise over two sessions. The criterion variables were myoelectric activity and heart rate. One set was performed with an elastic band grip width that permitted 15 maximum repetitions in the selected exercise, and another set was performed with a grip width 50% more than the 15RM grip. Following the final repetition of each set, active muscle (AM and overall body (O ratings of perceived exertion (RPE were collected from the Thera-Band® resistance exercise scale and the OMNI-Resistance Exercise Scale of perceived exertion with Thera-Band® resistance bands (OMNI-RES EB. Construct validity was established by correlating the RPE from the OMNI-RES EB with the Thera-Band RPE scale using regression analysis. The results showed significant differences (p ≤ 0.05 in myoelectric activity, heart rate, and RPE scores between the low- and high-intensity sets. The intraclass correlation coefficient for active muscles and overall RPE scale scores was 0.67 and 0.58, respectively. There was a positive linear relationship between the RPE from the OMNI-RES EB and the Thera-Band scale. Validity coefficients for the RPE AM were r2 = 0.87 and ranged from r2 = 0.76 to 0.85 for the RPE O. Therefore, the Thera-Band Perceived Exertion Scale for Resistance Exercise can be used for monitoring elastic band exercise intensity. This would allow the training dosage to be better controlled within and between sessions. Moreover, the construct and concurrent validity indicates that the OMNI-RES EB measures similar properties of exertion as the Thera-Band RPE scale during elastic resistance exercise.

Design of Dual-Band Two-Branch-Line Couplers with Arbitrary Coupling Coefficients in Bands

Directory of Open Access Journals (Sweden)

I. Prudyus

2014-12-01

Full Text Available A new approach to design dual-band two-branch couplers with arbitrary coupling coefficients at two operating frequency bands is proposed in this article. The method is based on the usage of equivalent subcircuits input reactances of the even-mode and odd-mode excitations. The exact design formulas for three options of the dual-band coupler with different location and number of stubs are received. These formulas permit to obtain the different variants for each structure in order to select the physically realizable solution and can be used in broad range of frequency ratio and power division ratio. For verification, three different dual-band couplers, which are operating at 2.4/3.9 GHz with different coupling coefficients (one with 3/6 dB, and 10/3 dB two others are designed, simulated, fabricated and tested. The measured results are in good agreement with the simulated ones.

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.

Block 3 X-band receiver-exciter

Science.gov (United States)

Johns, C. E.

1987-01-01

The development of an X-band exciter, for use in the X-Band Uplink Subsystem, was completed. The exciter generates the drive signal for the X-band transmitter and also generates coherent test signals for the S- and X-band Block 3 translator and a Doppler reference signal for the Doppler extractor system. In addition to the above, the exciter generates other reference signals that are described. Also presented is an overview of the exciter design and some test data taken on the prototype. A brief discussion of the Block 3 Doppler extractor is presented.

Fluctuation diamagnetism in two-band superconductors

Science.gov (United States)

Adachi, Kyosuke; Ikeda, Ryusuke

2016-04-01

Anomalously large fluctuation diamagnetism around the superconducting critical temperature has been recently observed in iron selenide (FeSe) [Kasahara et al. (unpublished)]. This indicates that superconducting fluctuations (SCFs) play a more significant role in FeSe, which supposedly has a two-band structure, than in the familiar single-band superconductors. Motivated by the data on FeSe, SCF-induced diamagnetism is examined in a two-band system, on the basis of a phenomenological approach with a Ginzburg-Landau functional. The obtained results indicate that the SCF-induced diamagnetism may be more enhanced than that in a single-band system due to the existence of two distinct fluctuation modes. Such enhancement of diamagnetism unique to a two-band system seems consistent with the large diamagnetism observed in FeSe, though still far from a quantitative agreement.

U-shaped Relation between Prestimulus Alpha-band and Poststimulus Gamma-band Power in Temporal Tactile Perception in the Human Somatosensory Cortex.

Science.gov (United States)

Wittenberg, Marc André; Baumgarten, Thomas J; Schnitzler, Alfons; Lange, Joachim

2018-04-01

Neuronal oscillations are a ubiquitous phenomenon in the human nervous system. Alpha-band oscillations (8-12 Hz) have been shown to correlate negatively with attention and performance, whereas gamma-band oscillations (40-150 Hz) correlate positively. Here, we studied the relation between prestimulus alpha-band power and poststimulus gamma-band power in a suprathreshold tactile discrimination task. Participants received two electrical stimuli to their left index finger with different SOAs (0 msec, 100 msec, intermediate SOA, intermediate SOA ± 10 msec). The intermediate SOA was individually determined so that stimulation was bistable, and participants perceived one stimulus in half of the trials and two stimuli in the other half. We measured neuronal activity with magnetoencephalography (MEG). In trials with intermediate SOAs, behavioral performance correlated inversely with prestimulus alpha-band power but did not correlate with poststimulus gamma-band power. Poststimulus gamma-band power was high in trials with low and high prestimulus alpha-band power and low for intermediate prestimulus alpha-band power (i.e., U-shaped). We suggest that prestimulus alpha activity modulates poststimulus gamma activity and subsequent perception: (1) low prestimulus alpha-band power leads to high poststimulus gamma-band power, biasing perception such that two stimuli were perceived; (2) intermediate prestimulus alpha-band power leads to low gamma-band power (interpreted as inefficient stimulus processing), consequently, perception was not biased in either direction; and (3) high prestimulus alpha-band power leads to high poststimulus gamma-band power, biasing perception such that only one stimulus was perceived.

Electron correlations in narrow band systems

International Nuclear Information System (INIS)

Kishore, R.

1983-01-01

The effect of the electron correlations in narrow bands, such as d(f) bands in the transition (rare earth) metals and their compounds and the impurity bands in doped semiconductors is studied. The narrow band systems is described, by the Hubbard Hamiltonian. By proposing a local self-energy for the interacting electron, it is found that the results are exact in both atomic and band limits and reduce to the Hartree Fock results for U/Δ → 0, where U is the intra-atomic Coulomb interaction and Δ is the bandwidth of the noninteracting electrons. For the Lorentzian form of the density of states of the noninteracting electrons, this approximation turns out to be equivalent to the third Hubbard approximation. A simple argument, based on the mean free path obtained from the imaginary part of the self energy, shows how the electron correlations can give rise to a discontinous metal-nonmetal transition as proposed by Mott. The band narrowing and the existence of the satellite below the Fermi energy in Ni, found in photoemission experiments, can also be understood. (Author) [pt

InfiniBand-Experiences at the Forschungszentrum Karlsruhe

International Nuclear Information System (INIS)

Schwickerath, Ulrich; Heiss, Andreas

2006-01-01

The Institute for Scientific Computing (IWR) at the Forschungszentrum Karlsruhe has been evaluating the InfiniBand [InfiniBand Trade Association, InfiniBand Architecture Specification, Release 1.0, October 24, 2000] technology since end of the year 2002. The performance of the interconnect has been tested on different platforms and architectures using MPI. Sequential file transfer performance was measured with the RFIO protocol running on native InfiniBand [Ulrich Schwickerath, Andreas Heiss, Nucl. Instr. and Meth. A 534 (2004) 130, http://www.fzk.de/infiniband], and a newly developed InfiniBand-enabled version of the XROOTD

Band head spin assignment of superdeformed bands in 133Pr using two-parameter formulae

Science.gov (United States)

Sharma, Honey; Mittal, H. M.

2018-03-01

The two-parameter formulae viz. the power index formula, the nuclear softness formula and the VMI model are adopted to accredit the band head spin (I0) of four superdeformed rotational bands in 133Pr. The technique of least square fitting is used to accredit the band head spin for four superdeformed rotational bands in 133Pr. The root mean deviation among the computed transition energies and well-known experimental transition energies are attained by extracting the model parameters from the two-parameter formulae. The determined transition energies are in excellent agreement with the experimental transition energies, whenever exact spins are accredited. The power index formula coincides well with the experimental data and provides minimum root mean deviation. So, the power index formula is more efficient tool than the nuclear softness formula and the VMI model. The deviation of dynamic moment of inertia J(2) against the rotational frequency is also examined.

S-band and X-band integrated PWT photoelectron linacs

International Nuclear Information System (INIS)

Yu, D.; Newsham, D.; Zeng, J.; Rosenzweig, J.

2001-01-01

A compact high-energy injector, which has been developed by DULY Research Inc., will have wide scientific, industrial, and medical applications. The new photoelectron injector integrates the photocathode directly into a multicell linear accelerator. By focusing the beam with solenoids or permanent magnets, and producing high current with low emittance, high brightness and low energy spread are achieved. In addition to providing a small footprint and improved beam quality in an integrated structure, the compact system considerably simplifies external subsystems required to operate the photoelectron linac, including rf power transport, beam focusing, vacuum and cooling. The photoelectron linac employs an innovative Plane-Wave-Transformer (PWT) design, which provides strong cell-to-cell coupling, relaxes manufacturing tolerances and facilitates the attachment of external ports to the compact structure with minimal field interference. DULY Research Inc. under the support of the DOE Small Business Innovation Research (SBIR) program, has developed, constructed and installed a 20-MeV, S-band compact electron source at UCLA. Cold test results for this device are presented. DULY Research is also actively engaged in the development of an X-band photoelectron linear accelerator in a SBIR project. When completed, the higher frequency structure will be approximately three times smaller. Design considerations for this device are discussed following the S-band cold test results

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…

Does the chromatic Mach bands effect exist?

Science.gov (United States)

Tsofe, Avital; Spitzer, Hedva; Einav, Shmuel

2009-06-30

The achromatic Mach bands effect is a well-known visual illusion, discovered over a hundred years ago. This effect has been investigated thoroughly, mainly for its brightness aspect. The existence of Chromatic Mach bands, however, has been disputed. In recent years it has been reported that Chromatic Mach bands are not perceived under controlled iso-luminance conditions. However, here we show that a variety of Chromatic Mach bands, consisting of chromatic and achromatic regions, separated by a saturation ramp, can be clearly perceived under iso-luminance and iso-brightness conditions. In this study, observers' eye movements were recorded under iso-brightness conditions. Several observers were tested for their ability to perceive the Chromatic Mach bands effect and its magnitude, across different cardinal and non-cardinal Chromatic Mach bands stimuli. A computational model of color adaptation, which predicted color induction and color constancy, successfully predicts this variation of Chromatic Mach bands. This has been tested by measuring the distance of the data points from the "achromatic point" and by calculating the shift of the data points from predicted complementary lines. The results suggest that the Chromatic Mach bands effect is a specific chromatic induction effect.

The spectroscopy of fission fragments

International Nuclear Information System (INIS)

Phillips, W.R.

1998-01-01

High-resolution measurements on γ rays from fission fragments have provided a rich source of information, unobtainable at the moment in any other way, on the spectroscopy of neutron-rich nuclei. In recent years important data have been obtained on the yrast- and near yrast-structure of neutron-rich fission fragments. We discuss the scope of measurements which can be made on prompt gamma rays from secondary fission fragments, the techniques used in the experiments and some results recently obtained. (author)

In-Sample Confidence Bands and Out-of-Sample Forecast Bands for Time-Varying Parameters in Observation Driven Models

NARCIS (Netherlands)

Blasques, F.; Koopman, S.J.; Lasak, K.A.; Lucas, A.

2016-01-01

We study the performances of alternative methods for calculating in-sample confidence and out-of-sample forecast bands for time-varying parameters. The in-sample bands reflect parameter uncertainty, while the out-of-sample bands reflect not only parameter uncertainty, but also innovation

Robust and adaptive band-to-band image transform of UAS miniature multi-lens multispectral camera

Science.gov (United States)

Jhan, Jyun-Ping; Rau, Jiann-Yeou; Haala, Norbert

2018-03-01

Utilizing miniature multispectral (MS) or hyperspectral (HS) cameras by mounting them on an Unmanned Aerial System (UAS) has the benefits of convenience and flexibility to collect remote sensing imagery for precision agriculture, vegetation monitoring, and environment investigation applications. Most miniature MS cameras adopt a multi-lens structure to record discrete MS bands of visible and invisible information. The differences in lens distortion, mounting positions, and viewing angles among lenses mean that the acquired original MS images have significant band misregistration errors. We have developed a Robust and Adaptive Band-to-Band Image Transform (RABBIT) method for dealing with the band co-registration of various types of miniature multi-lens multispectral cameras (Mini-MSCs) to obtain band co-registered MS imagery for remote sensing applications. The RABBIT utilizes modified projective transformation (MPT) to transfer the multiple image geometry of a multi-lens imaging system to one sensor geometry, and combines this with a robust and adaptive correction (RAC) procedure to correct several systematic errors and to obtain sub-pixel accuracy. This study applies three state-of-the-art Mini-MSCs to evaluate the RABBIT method's performance, specifically the Tetracam Miniature Multiple Camera Array (MiniMCA), Micasense RedEdge, and Parrot Sequoia. Six MS datasets acquired at different target distances and dates, and locations are also applied to prove its reliability and applicability. Results prove that RABBIT is feasible for different types of Mini-MSCs with accurate, robust, and rapid image processing efficiency.

Prenatal diagnosis of amniotic band syndrome

Directory of Open Access Journals (Sweden)

Laxmi Devi Padmanabhan

2016-01-01

Full Text Available Amniotic band can cause a broad spectrum of anomalies ranging from simple band constrictions to major craniofacial and visceral defects. It can cause significant neonatal morbidity. Accurate diagnosis will help in the management of the present pregnancy and in counseling with regard to future pregnancies. Here we report three cases of amniotic band syndrome detected in the prenatal period.

Emission bands of phosphorus and calculation of band structure of rare earth phosphides

International Nuclear Information System (INIS)

Al'perovich, G.I.; Gusatinskij, A.N.; Geguzin, I.I.; Blokhin, M.A.; Torbov, V.I.; Chukalin, V.I.; AN SSSR, Moscow. Inst. Novykh Khimicheskikh Problem)

1977-01-01

The method of x-ray emission spectroscopy has been used to investigate the electronic structure of monophosphides of rare-earth metals (REM). The fluorescence K bands of phosphorus have been obtained in LaP, PrP, SmP, GdP, TbP, DyP, HoP, ErP, TmP, YbP, and LuP and also the Lsub(2,3) bands of phosphorus in ErP, TmP, YbP, and LuP. Using the Green function technique involving the muffin-tin potential, the energy spectrum for ErP has been calculated in the single-electron approximation. The hystogram of electronic state distribution N(E) is compared with the experimental K and Lsub(2,3) bands of phosphorus in ErP. The agreement between the main details of N(E) and that of x-ray spectra allows to state that the model used provides a good description of the electron density distribution in crystals of REM monophosphides. In accordance with the character of the N(E) distribution the compounds under study are classified as semimetals or semiconductors with a very narrow forbidden band

A comparison of L-band and C-band rf guns as sources for inline-injection systems

International Nuclear Information System (INIS)

Gallardo, J.C.; Kirk, H.G.; Meyerer, T.

1994-12-01

We consider the beam dynamics associated with installing a BNL type 1 1/2 cell L-band or C-band rf gun before two TESLA L-band cryomodules. This system will deliver a 25 MeV electron beam with peak currents on the order of 100 A suitable for further magnetic compression. evaluate the injection systems utilizing the electron beam dynamic code PARMELA from the point of view of minimizing the transverse invariant emittance

Mars Global Surveyor Ka-Band Frequency Data Analysis

Science.gov (United States)

Morabito, D.; Butman, S.; Shambayati, S.

2000-01-01

The Mars Global Surveyor (MGS) spacecraft, launched on November 7, 1996, carries an experimental space-to-ground telecommunications link at Ka-band (32 GHz) along with the primary X-band (8.4 GHz) downlink. The signals are simultaneously transmitted from a 1.5-in diameter parabolic high gain antenna (HGA) on MGS and received by a beam-waveguide (BWG) R&D 34-meter antenna located in NASA's Goldstone Deep Space Network (DSN) complex near Barstow, California. The projected 5-dB link advantage of Ka-band relative to X-band was confirmed in previous reports using measurements of MGS signal strength data acquired during the first two years of the link experiment from December 1996 to December 1998. Analysis of X-band and Ka-band frequency data and difference frequency (fx-fka)/3.8 data will be presented here. On board the spacecraft, a low-power sample of the X-band downlink from the transponder is upconverted to 32 GHz, the Ka-band frequency, amplified to I-W using a Solid State Power Amplifier, and radiated from the dual X/Ka HGA. The X-band signal is amplified by one of two 25 W TWTAs. An upconverter first downconverts the 8.42 GHz X-band signal to 8 GHz and then multiplies using a X4 multiplier producing the 32 GHz Ka-band frequency. The frequency source selection is performed by an RF switch which can be commanded to select a VCO (Voltage Controlled Oscillator) or USO (Ultra-Stable Oscillator) reference. The Ka-band frequency can be either coherent with the X-band downlink reference or a hybrid combination of the USO and VCO derived frequencies. The data in this study were chosen such that the Ka-band signal is purely coherent with the X-band signal, that is the downconverter is driven by the same frequency source as the X-band downlink). The ground station used to acquire the data is DSS-13, a 34-meter BWG antenna which incorporates a series of mirrors inside beam waveguide tubes which guide the energy to a subterranean pedestal room, providing a stable environment

Adhesives for fixed orthodontic bands.

Science.gov (United States)

Millett, Declan T; Glenny, Anne-Marie; Mattick, Rye Cr; Hickman, Joy; Mandall, Nicky A

2016-10-25

Orthodontic treatment involves using fixed or removable appliances (dental braces) to correct the positions of teeth. It has been shown that the quality of treatment result obtained with fixed appliances is much better than with removable appliances. Fixed appliances are, therefore, favoured by most orthodontists for treatment. The success of a fixed orthodontic appliance depends on the metal attachments (brackets and bands) being attached securely to the teeth so that they do not become loose during treatment. Brackets are usually attached to the front and side teeth, whereas bands (metal rings that go round the teeth) are more commonly used on the back teeth (molars). A number of adhesives are available to attach bands to teeth and it is important to understand which group of adhesives bond most reliably, as well as reducing or preventing dental decay during the treatment period. To evaluate the effectiveness of the adhesives used to attach bands to teeth during fixed appliance treatment, in terms of:(1) how often the bands come off during treatment; and(2) whether they protect the banded teeth against decay during fixed appliance treatment. The following electronic databases were searched: Cochrane Oral Health's Trials Register (searched 2 June 2016), Cochrane Central Register of Controlled Trials (CENTRAL; 2016, Issue 5) in the Cochrane Library (searched 2 June 2016), MEDLINE Ovid (1946 to 2 June 2016) and EMBASE Ovid (1980 to 2 June 2016). We searched ClinicalTrials.gov and the World Health Organization International Clinical Trials Registry Platform for ongoing trials. No restrictions were placed on the language or date of publication when searching the electronic databases. Randomised and controlled clinical trials (RCTs and CCTs) (including split-mouth studies) of adhesives used to attach orthodontic bands to molar teeth were selected. Patients with full arch fixed orthodontic appliance(s) who had bands attached to molars were included. All review authors

Super rigid nature of super-deformed bands

International Nuclear Information System (INIS)

Sharma, Neha; Mittal, H.M.; Jain, A.K.

2012-01-01

The phenomenon of high-spin super-deformation represents one of the most remarkable discoveries in nuclear physics. A large number of SD bands have been observed in A = 60, 80, 130, 150, 190 mass regions. The cascades of SD bands are known to be connected by electric quadruple E2 transitions. Because of absence of linking transitions between superdeformed (SD) and normal deformed (ND) levels, the spin assignments of most of these bands carry a minimum uncertainty ≈ 1-2ħ. It was found in an analysis of SD bands in the context of semi classical approach that moment of inertia comes close to the rigid body value in most of the cases. Lack of knowledge of spins has led to an emphasis on the study of dynamical moment of inertia of SD bands and systematic of kinematic moment of inertia has not been examined so far. In this paper, we extract the band moment of inertia J 0 and softness parameter (σ) of all the SD bands corresponding to axes ratio (x) = 1.5 and present their systematic

Design of an S band narrow-band bandpass BAW filter

Science.gov (United States)

Gao, Yang; Zhao, Kun-li; Han, Chao

2017-11-01

An S band narrowband bandpass filter BAW with center frequency 2.460 GHz, bandwidth 41MHz, band insertion loss - 1.154 dB, the passband ripple 0.9 dB, the out of band rejection about -42.5dB@2.385 GHz; -45.5dB@2.506 GHz was designed for potential UAV measurement and control applications. According to the design specifications, the design is as follows: each FBAR's stack was designed in BAW filter by using Mason model. Each FBAR's shape was designed with the method of apodization electrode. The layout of BAW filter was designed. The acoustic-electromagnetic cosimulation model was built to validate the performance of the designed BAW filter. The presented design procedure is a common one, and there are two characteristics: 1) an A and EM co-simulation method is used for the final BAW filter performance validation in the design stage, thus ensures over-optimistic designs by the bare 1D Mason model are found and rejected in time; 2) An in-house developed auto-layout method is used to get compact BAW filter layout, which simplifies iterative error-and-try work here and output necessary in-plane geometry information to the A and EM cosimulation model.

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.

8-band and 14-band kp modeling of electronic band structure and material gain in Ga(In)AsBi quantum wells grown on GaAs and InP substrates

Energy Technology Data Exchange (ETDEWEB)

Gladysiewicz, M.; Wartak, M. S. [Faculty of Fundamental Problems of Technology, Wroclaw University of Technology, Wybrzeze Wyspianskiego 27, 50-370 Wroclaw (Poland); Department of Physics and Computer Science, Wilfrid Laurier University, Waterloo, Ontario N2L 3C5 (Canada); Kudrawiec, R. [Faculty of Fundamental Problems of Technology, Wroclaw University of Technology, Wybrzeze Wyspianskiego 27, 50-370 Wroclaw (Poland)

2015-08-07

The electronic band structure and material gain have been calculated for GaAsBi/GaAs quantum wells (QWs) with various bismuth concentrations (Bi ≤ 15%) within the 8-band and 14-band kp models. The 14-band kp model was obtained by extending the standard 8-band kp Hamiltonian by the valence band anticrossing (VBAC) Hamiltonian, which is widely used to describe Bi-related changes in the electronic band structure of dilute bismides. It has been shown that in the range of low carrier concentrations n < 5 × 10{sup 18 }cm{sup −3}, material gain spectra calculated within 8- and 14-band kp Hamiltonians are similar. It means that the 8-band kp model can be used to calculate material gain in dilute bismides QWs. Therefore, it can be applied to analyze QWs containing new dilute bismides for which the VBAC parameters are unknown. Thus, the energy gap and electron effective mass for Bi-containing materials are used instead of VBAC parameters. The electronic band structure and material gain have been calculated for 8 nm wide GaInAsBi QWs on GaAs and InP substrates with various compositions. In these QWs, Bi concentration was varied from 0% to 5% and indium concentration was tuned in order to keep the same compressive strain (ε = 2%) in QW region. For GaInAsBi/GaAs QW with 5% Bi, gain peak was determined to be at about 1.5 μm. It means that it can be possible to achieve emission at telecommunication windows (i.e., 1.3 μm and 1.55 μm) for GaAs-based lasers containing GaInAsBi/GaAs QWs. For GaInAsBi/Ga{sub 0.47}In{sub 0.53}As/InP QWs with 5% Bi, gain peak is predicted to be at about 4.0 μm, i.e., at the wavelengths that are not available in current InP-based lasers.

The complex band structure for armchair graphene nanoribbons

International Nuclear Information System (INIS)

Zhang Liu-Jun; Xia Tong-Sheng

2010-01-01

Using a tight binding transfer matrix method, we calculate the complex band structure of armchair graphene nanoribbons. The real part of the complex band structure calculated by the transfer matrix method fits well with the bulk band structure calculated by a Hermitian matrix. The complex band structure gives extra information on carrier's decay behaviour. The imaginary loop connects the conduction and valence band, and can profoundly affect the characteristics of nanoscale electronic device made with graphene nanoribbons. In this work, the complex band structure calculation includes not only the first nearest neighbour interaction, but also the effects of edge bond relaxation and the third nearest neighbour interaction. The band gap is classified into three classes. Due to the edge bond relaxation and the third nearest neighbour interaction term, it opens a band gap for N = 3M − 1. The band gap is almost unchanged for N = 3M + 1, but decreased for N = 3M. The maximum imaginary wave vector length provides additional information about the electrical characteristics of graphene nanoribbons, and is also classified into three classes

Superdeformed nuclei

International Nuclear Information System (INIS)

Janssens, R.V.F.; Khoo, T.L.

1991-01-01

Superdeformation was first proposed some twenty years ago to explain the fission isomers observed in some actinide nuclei. It was later realized that superdeformed shapes can occur at high angular momentum in lighter nuclei. The interest in the mechanisms responsible for these exotic shapes has increased enormously with the discovery of a superdeformed band of nineteen discrete lines in 152 Dy (8). At about the same time, evidence for highly deformed nuclei (axis ratio 3:2) was also reported near 132 Ce(9). Striking properties emerged from the first experiments, such as the essentially constant energy spacing between transitions (picket-fence spectra), the unexpectedly strong population of superdeformed bands at high spins, and the apparent lack of a link between the superdeformed states and the yrast levels. These findings were reviewed by Nolan and Twin. The present article follows upon their work and discusses the wealth of information that has since become available. This includes the discovery of a new island of superdeformation near A = 190, the detailed spectroscopy of ground and excited bands in the superdeformed well near A = 150 and A = 190, the surprising occurrence of superdeformed bands with identical transition energies in nuclei differing by one or two mass units, and the improved understanding of mechanisms responsible for the feeding into and the decay out of the superdeformed states

Band to Band Tunneling (BBT) Induced Leakage Current Enhancement in Irradiated Fully Depleted SOI Devices

Science.gov (United States)

Adell, Phillipe C.; Barnaby, H. J.; Schrimpf, R. D.; Vermeire, B.

2007-01-01

We propose a model, validated with simulations, describing how band-to-band tunneling (BBT) affects the leakage current degradation in some irradiated fully-depleted SOI devices. The dependence of drain current on gate voltage, including the apparent transition to a high current regime is explained.

Formation of Degenerate Band Gaps in Layered Systems

Directory of Open Access Journals (Sweden)

Alexey P. Vinogradov

2012-06-01

Full Text Available In the review, peculiarities of spectra of one-dimensional photonic crystals made of anisotropic and/or magnetooptic materials are considered. The attention is focused on band gaps of a special type—the so called degenerate band gaps which are degenerate with respect to polarization. Mechanisms of formation and properties of these band gaps are analyzed. Peculiarities of spectra of photonic crystals that arise due to the linkage between band gaps are discussed. Particularly, it is shown that formation of a frozen mode is caused by linkage between Brillouin and degenerate band gaps. Also, existence of the optical Borrmann effect at the boundaries of degenerate band gaps and optical Tamm states at the frequencies of degenerate band gaps are analyzed.

Study of rotational band in 111Sn

International Nuclear Information System (INIS)

Ganguly, S.; Banerjee, P.; Ray, I.; Kshetri, R.; Raut, R.; Goswami, A.; Saha Sarkar, M.; Bhattacharya, S.; Mukherjee, A.; Mukherjee, G.; Basu, S.K.; Mukhopadhyay, S.

2006-01-01

The motivation of the present work is to study the negative-parity rotational band in 111 Sn. Study of the lifetimes of the states of the rotational band is expected to provide information on their structures as well as the band termination phenomenon

Synthesis and design of waveguide band-stop filters without out-of-band spurious responses for plasma diagnosis

Energy Technology Data Exchange (ETDEWEB)

Montejo-Garai, Jose R., E-mail: jr@etc.upm.es [Departamento de Electromagnetismo y Teoria de Circuitos, Universidad Politecnica de Madrid, Ciudad Universitaria s/n, Madrid 20840 (Spain); Leal-Sevillano, Carlos A. [Departamento de Electromagnetismo y Teoria de Circuitos, Universidad Politecnica de Madrid, Ciudad Universitaria s/n, Madrid 20840 (Spain); Ruiz-Cruz, Jorge A. [Escuela Politecnica Superior, Universidad Autonoma de Madrid, C/Fco. Tomas y Valiente 11, Madrid 28409 (Spain); Rebollar, Jesus M. [Departamento de Electromagnetismo y Teoria de Circuitos, Universidad Politecnica de Madrid, Ciudad Universitaria s/n, Madrid 20840 (Spain); Estrada, Teresa [T. Laboratorio Nacional de Fusion, Asociacion Euratom-CIEMAT, Madrid 28040 (Spain)

2012-09-15

Highlights: Black-Right-Pointing-Pointer A rigorous systematic design process based on circuit synthesis is proposed for band-stop filters. Black-Right-Pointing-Pointer The new compact E-plane waveguide structure reduces drastically the unwanted resonances in a very large pass band. Black-Right-Pointing-Pointer The manufacturing process together with the computation effort is significantly reduced. Black-Right-Pointing-Pointer Experimental results validate the state-of-art electrical responses. - Abstract: Band-stop or notch filters play a crucial role in plasma diagnosis systems to protect receivers from the stray radiation. In this work, a rigorous design process based on circuit synthesis in addition to an extremely compact E-plane waveguide structure is proposed for this kind of filters. On the one hand, the transfer function verifying the rejection specification is analytically obtained, fixing the minimum number of required cavities. On the other hand, a coupling structure that reduces drastically the unwanted resonances in filters with a very large pass band requirement, is presented. This coupling between the rejection cavities and the main rectangular waveguide has additional advantages; (a) unlike typical inductive irises, large coupling coefficients can be implemented (b) a pure E-plane configuration is achieved, which simplifies the manufacturing and also reduces significantly the computational effort. Experimental validation is demonstrated by two pseudo-elliptic fifth-order band-stop filters fabricated and measured in Ka and V bands. In both cases, the filters are free of spurious resonances in their total operation bands.

Synthesis and design of waveguide band-stop filters without out-of-band spurious responses for plasma diagnosis

International Nuclear Information System (INIS)

Montejo-Garai, José R.; Leal-Sevillano, Carlos A.; Ruiz-Cruz, Jorge A.; Rebollar, Jesús M.; Estrada, Teresa

2012-01-01

Highlights: ► A rigorous systematic design process based on circuit synthesis is proposed for band-stop filters. ► The new compact E-plane waveguide structure reduces drastically the unwanted resonances in a very large pass band. ► The manufacturing process together with the computation effort is significantly reduced. ► Experimental results validate the state-of-art electrical responses. - Abstract: Band-stop or notch filters play a crucial role in plasma diagnosis systems to protect receivers from the stray radiation. In this work, a rigorous design process based on circuit synthesis in addition to an extremely compact E-plane waveguide structure is proposed for this kind of filters. On the one hand, the transfer function verifying the rejection specification is analytically obtained, fixing the minimum number of required cavities. On the other hand, a coupling structure that reduces drastically the unwanted resonances in filters with a very large pass band requirement, is presented. This coupling between the rejection cavities and the main rectangular waveguide has additional advantages; (a) unlike typical inductive irises, large coupling coefficients can be implemented (b) a pure E-plane configuration is achieved, which simplifies the manufacturing and also reduces significantly the computational effort. Experimental validation is demonstrated by two pseudo-elliptic fifth-order band-stop filters fabricated and measured in Ka and V bands. In both cases, the filters are free of spurious resonances in their total operation bands.

Review of wide band-gap semiconductors technology

Directory of Open Access Journals (Sweden)

Jin Haiwei

2016-01-01

Full Text Available Silicon carbide (SiC and gallium nitride (GaN are typical representative of the wide band-gap semiconductor material, which is also known as third-generation semiconductor materials. Compared with the conventional semiconductor silicon (Si or gallium arsenide (GaAs, wide band-gap semiconductor has the wide band gap, high saturated drift velocity, high critical breakdown field and other advantages; it is a highly desirable semiconductor material applied under the case of high-power, high-temperature, high-frequency, anti-radiation environment. These advantages of wide band-gap devices make them a hot spot of semiconductor technology research in various countries. This article describes the research agenda of United States and European in this area, focusing on the recent developments of the wide band-gap technology in the US and Europe, summed up the facing challenge of the wide band-gap technology.

The spectroscopy of fission fragments

Energy Technology Data Exchange (ETDEWEB)

Phillips, W.R. [Department of Physics and Astronomy, University of Manchester, Manchester, M13 9PL (United Kingdom); Collaboration: La Direction des Sciences de la Matiere du CEA (FR); Le Fonds National de la Recherche Scientifique de Belgique (BE)

1998-12-31

High-resolution measurements on {gamma} rays from fission fragments have provided a rich source of information, unobtainable at the moment in any other way, on the spectroscopy of neutron-rich nuclei. In recent years important data have been obtained on the yrast- and near yrast-structure of neutron-rich fission fragments. We discuss the scope of measurements which can be made on prompt gamma rays from secondary fission fragments, the techniques used in the experiments and some results recently obtained. (author) 24 refs., 8 figs., 1 tab.

Band-Structure of Thallium by the LMTO Method

DEFF Research Database (Denmark)

Holtham, P. M.; Jan, J. P.; Skriver, Hans Lomholt

1977-01-01

by an energy gap. The 6d and 7s bands were found to be far above the Fermi level and the 5d states were found to be far below it. Fermi surface properties and the electronic specific heat are computed and compared with experiment. The joint density of states has also been computed and is in reasonable...... and p bands for the HCP structure. Energy bands have been evaluated both with and without spin-orbit coupling which is particularly large in thallium. Energy bands close to the Fermi level were found to be mainly 6p like in character. The 6s states lay below the 6p bands and were separated from them......The relativistic band structure of thallium has been calculated using the linear muffin-tin orbital (LMTO) method. The positions and extents of the bands were found to follow the Wigner-Seitz rule approximately, and the origin of the dispersion of the bands was established from the canonical s...

Complex band structure and electronic transmission eigenchannels

DEFF Research Database (Denmark)

Jensen, Anders; Strange, Mikkel; Smidstrup, Soren

2017-01-01

and complex band structure, in this case individual eigenchannel transmissions and different complex bands. We present calculations of decay constants for the two most conductive states as determined by complex band structure and standard DFT Landauer transport calculations for one semi-conductor and two...

The Keenan and Wing bands in S stars

International Nuclear Information System (INIS)

Lambert, D.L.; Clegg, R.E.S.

1980-01-01

New observations of the near infrared spectra of S stars are presented as part of a survey of the unidentified Keenan and Wing bands. Bandhead wavelengths accurate to 0.5 A are presented. A new band is found at 9014 A. The bands are not present in normal M giants and dwarfs. Laboratory spectroscopy of heavy element oxides is reported. Several new identifications are proposed. The 10 300 A Wing band is identified with the Δv = - 1 sequence of the ZrO 9300 A Δv = 0 bands. The ZrO B 1 PI-A 1 Δ (Δv = 0) system may be responsible for either the 9736 A or the 10 515 A Wing bands. Two new bands in the near infrared at 8219 and 8235 A are provided by CeO. A new band with heads at 7503 and 7509 A in a spectrum of R And is tentatively attributed to YS. A band at 8268 A in M stars is the TiO delta(2-1) head. The 8610 A Keenan band is not due to CrH. Potential carriers of the Keenan and Wing bands are reviewed. It is suggested that the heavy element sulphides and, perhaps, chlorides are leading candidates. Identification of YS in R And may provide the first evidence for these sulphides. ZrS is a leading candidate for which laboratory spectroscopy is needed. (author)

Exact folded-band chaotic oscillator.

Science.gov (United States)

Corron, Ned J; Blakely, Jonathan N

2012-06-01

An exactly solvable chaotic oscillator with folded-band dynamics is shown. The oscillator is a hybrid dynamical system containing a linear ordinary differential equation and a nonlinear switching condition. Bounded oscillations are provably chaotic, and successive waveform maxima yield a one-dimensional piecewise-linear return map with segments of both positive and negative slopes. Continuous-time dynamics exhibit a folded-band topology similar to Rössler's oscillator. An exact solution is written as a linear convolution of a fixed basis pulse and a discrete binary sequence, from which an equivalent symbolic dynamics is obtained. The folded-band topology is shown to be dependent on the symbol grammar.

Fade Mitigation Techniques at Ka-Band

Science.gov (United States)

Dissanayake, Asoka (Editor)

1996-01-01

Rain fading is the dominant propagation impairment affecting Ka-band satellite links and rain fade mitigation is a key element in the design of Ka-band satellite networks. Some of the common fade mitigation techniques include: power control, diversity, adaptive coding, and resource sharing. The Advanced Communications Technology Satellite (ACTS) provides an excellent opportunity to develop and test Ka-band rain impairment amelioration techniques. Up-link power control and diversity are discussed in this paper.

47 CFR 15.715 - TV bands database administrator.

Science.gov (United States)

2010-10-01

... 47 Telecommunication 1 2010-10-01 2010-10-01 false TV bands database administrator. 15.715 Section... Band Devices § 15.715 TV bands database administrator. The Commission will designate one or more entities to administer a TV bands database. Each database administrator shall: (a) Maintain a database that...

What band rocks the MTB? (Invited)

Science.gov (United States)

Kind, J.; García-Rubio, I.; Gehring, A. U.

2013-12-01

Magnetotactic bacteria (MTB) are a polyphyletic group of bacteria that have been found in marine and lacustrine environments and soils [e.g. 1]. The hallmark of MTB is their intracellular formation of magnetosomes, single-domain ferrimagnetic particles that are aligned in chains. The chain configuration generates a strong magnetic dipole, which is used as magnetic compass to move the MTB into their favorable habit. The term band corresponds to a frequency window of microwaves in the gigahertz (GHz) range. Ferromagnetic resonance (FMR) spectroscopy uses the microwave absorption in a magnetic field to analyze the anisotropy properties and the domain state of magnetic materials. Specific microwave frequency causes absorption in a characteristic magnetic field range. For the investigation of MTB we use S-band (4.02 GHz), X-band (9.47 GHz), and Q-band (34.16 GHz). Experiments on cultured MTB and on sediment samples of Holocene age showed that absorption in X- and Q-band occurs when the sample is in a saturated or nearly saturated state [2, 3]. By contrast, absorption in the S-band appears in lower magnetic fields, where the sample is far from saturation. All FMR spectra show two distinct low-field features that can be assigned to magnetite particles in chains, aligned parallel and perpendicular to the external magnetic field. The detailed separation of the parallel and perpendicular components in the bulk samples is hampered, because of the random orientation of the chains in the sample. The comparison of S-, X-, and Q-band shows that the lower the frequency the better the separation of the components. In the S-band FMR spectroscopy, the separation of chains parallel to the external magnetic field is supported by the internal field of the sample. This field is caused by the remanence that contributes to the external magnetic field to fulfill the resonance condition [3,4]. Considering the different FMR responses, it can be postulated that a lower microwave frequency

Head and hand detuning effect study of narrow-band against wide-band mobile phone antennas

DEFF Research Database (Denmark)

Bahramzy, Pevand; Pedersen, Gert Frølund

2014-01-01

Wide-band (WB) and narrow-band (NB) antennas in terms of performance are compared, when interacting with the user’s right head and hand (RHH). The investigations are done through experimental measurements, using standardised head phantom and hand. It is shown that WB antennas detune more than NB ...

Workshop: Western hemisphere network of bird banding programs

Science.gov (United States)

Celis-Murillo, A.

2007-01-01

Purpose: To promote collaboration among banding programs in the Americas. Introduction: Bird banding and marking provide indispensable tools for ornithological research, management, and conservation of migratory birds on migratory routes, breeding and non-breeding grounds. Many countries and organizations in Latin America and the Caribbean are in the process of developing or have expressed interest in developing national banding schemes and databases to support their research and management programs. Coordination of developing and existing banding programs is essential for effective data management, reporting, archiving and security, and most importantly, for gaining a fuller understanding of migratory bird conservation issues and how the banding data can help. Currently, there is a well established bird-banding program in the U.S.A. and Canada, and programs in other countries are being developed as well. Ornithologists in many Latin American countries and the Caribbean are interested in using banding and marking in their research programs. Many in the ornithological community are interested in establishing banding schemes and some countries have recently initiated independent banding programs. With the number of long term collaborative and international initiatives increasing, the time is ripe to discuss and explore opportunities for international collaboration, coordination, and administration of bird banding programs in the Western Hemisphere. We propose the second ?Western Hemisphere Network of Bird Banding Programs? workshop, in association with the SCSCB, to be an essential step in the progress to strengthen international partnerships and support migratory bird conservation in the Americas and beyond. This will be the second multi-national meeting to promote collaboration among banding programs in the Americas (the first meeting was held in October 8-9, 2006 in La Mancha, Veracruz, Mexico). The Second ?Western Hemisphere Network of Bird Banding Programs

Effect of Spindle Parameters of Woodworking Band Saw on the AE Value of Crack Band Saw Blade in Compound Material Processing (1)

Science.gov (United States)

Gao, Jin-gui; Jiang, Zhao-fang; Luo, Lai-peng

2017-04-01

Taking the MJ3210A motion band saw as the research object, the AE value of the band saw blade vibration was obtained by analyzing the VIBSYS vibration signal acquisition and analysis software system in Beijing, and the change of the AE value of the band saw and the crack was found out. The experimental results show that in the MJ3210A sports car sawing machine, the band saw blade with width of 130 mm is used, and the AE value of the cracked band saw blade is well in the high band saw blade AE value. Under the best working condition of the band saw, the band saw blade AE If the value exceeds 104.7 dB (A) above, it means that the band saw blade has at least one crack length greater than 1.38 mm for the crack defect and the need to replace the band saw blade in time. Different species with saw blade of the AE value is different, white pine wood minimum, the largest oak wood; according to a variety of wood processing AE instrument value to determine the band saw blade crack to the situation; so as to fully rational use of band saw blade, The failure and the degree of development to find a new method.

Search for chirality in 109Ag

International Nuclear Information System (INIS)

Timar, J.; Nyako, B.M.; Berek, G.; Gal, J.; Kalinka, G.; Krasznahorkay, A.; Molnar, J.; Zolnai, L.

2007-01-01

Complete text of publication follows. The existence of nuclear chirality is one of the most intriguing questions of contemporary high-spin nuclear structure studies. Rotational doublet-band candidates for chiral structures have been observed mostly in two regions of the nuclear chart: around 134 Pr, and around 104 Rh. In this second region chirality in the Rh isotopes are rather well studied, chiral doubling have also been observed in 100 Tc, however, results obtained for chirality in the studied Ag nuclei ( 105 Ag and 106 Ag) look rather contradictory. Thus, it is interesting to study these doublet bands in the nearby higher-mass Ag nuclei. In order to search for a chiral-candidate partner band to the yrast πg 9/2 v(h 11/2 ) 2 band in 109 Ag, high-spin states of this nucleus have been studied using the 96 Zr( 18 O,p4n) reaction. The experiment was performed at iThemba LABS using 8 Clover detectors of the AFRODITE array and the DIAMANT charged-particle array to detect the γ-rays and the charged particles, respectively. Altogether ∼140 million γγ-coincidence events were collected. Approximately 10 million events of them correspond to the reaction channel producing 109 Ag. No chiral candidate partner band has been found to the πg 9/2 v(h 11/2 ) 2 band with this statistics, however, the level scheme could be extended by several new levels and γ-transitions. A preliminary level scheme of 109 Ag obtained from the ongoing data analysis is shown in Fig. 1

The effect of density-of-state tails on band-to-band tunneling: Theory and application to tunnel field effect transistors

Science.gov (United States)

Sant, S.; Schenk, A.

2017-10-01

It is demonstrated how band tail states in the semiconductor influence the performance of a Tunnel Field Effect Transistor (TFET). As a consequence of the smoothened density of states (DOS) around the band edges, the energetic overlap of conduction and valence band states occurs gradually at the onset of band-to-band tunneling (BTBT), thus degrading the sub-threshold swing (SS) of the TFET. The effect of the band tail states on the current-voltage characteristics is modelled quantum-mechanically based on the idea of zero-phonon trap-assisted tunneling between band and tail states. The latter are assumed to arise from a 3-dimensional pseudo-delta potential proposed by Vinogradov [1]. This model potential allows the derivation of analytical expressions for the generation rate covering the whole range from very strong to very weak localization of the tail states. Comparison with direct BTBT in the one-band effective mass approximation reveals the essential features of tail-to-band tunneling. Furthermore, an analytical solution for the problem of tunneling from continuum states of the disturbed DOS to states in the opposite band is found, and the differences to direct BTBT are worked out. Based on the analytical expressions, a semi-classical model is implemented in a commercial device simulator which involves numerical integration along the tunnel paths. The impact of the tail states on the device performance is analyzed for a nanowire Gate-All-Around TFET. The simulations show that tail states notably impact the transfer characteristics of a TFET. It is found that exponentially decaying band tails result in a stronger degradation of the SS than tail states with a Gaussian decay of their density. The developed model allows more realistic simulations of TFETs including their non-idealities.

Higher superdeformed band members in {sup 190}Hg. Evidence for a band interaction

Energy Technology Data Exchange (ETDEWEB)

Bearden, I G; Daly, P J [Purdue Univ., Lafayette, IN (United States); Janssens, V F; Carpenter, M P; Ahmad, I; Khoo, T L; Lauritsen, T; Liang, Y [Argonne National Lab., IL (United States); Drigert, M W [Idaho National Engineering Lab., Idaho Falls, ID (United States); Garg, U; Reviol, W [Notre Dame Univ., IN (United States); Wyss, R [Joint Inst. for Heavy Ion Research, Oak Ridge, TN (United States)

1992-08-01

The superdeformed band of {sup 190}Hg has been traced up to a frequency {Dirac_h}{omega} {>=} 0.4 MeV by combining data from several experiments. A distinct change in the slope of the dynamic moment of inertia J{sup (2)} vs {Dirac_h}{omega} is observed at {Dirac_h}{omega} 0.32 MeV. This result is interpreted as evidence for a band interaction at the highest frequencies. Possible interpretations are reviewed. (author) 14 refs., 3 figs.

Generalized seniority scheme for bands in odd-A nuclei

International Nuclear Information System (INIS)

Gai, M.; Arima, A.; Strottman, D.

1980-01-01

The microscopic generalized seniority scheme is applied for the description of bands in odd-A nuclei. A perturbation expansion in terms of the core-particle interaction is performed. The first-order correction for the band head and the first member of the band is discussed. The specific band structure of a given nucleus, as well as the systematic trend of bands, is described in an explicit N-dependent analytical formula. This formula involves a linear dependence on N which arises from the first-order perturbation expansion. This term is shown responsible for the large deviation of the 11/2 - ΔJ=2 band spacing in I isotopes from the spacing of the Te core. All observed band structures of an odd-A nucleus arise from one simple core-particle coupling. Hence decoupled-E2 bands and strongly coupled ΔJ=1 bands, particle or hole bands of low-spin or high-spin orbits, all follow one simple N-dependence. This uniformity of bands is manifested in E2 bands in 53 I isotopes and deltaJ=1 bands in 51 Sb that have the same 52 Te cores. For the calculations a particle-particle force with a large contribution from a g delta force is used with a coupling constant that is deduced from 210 Pb. 1 figure

Present status of intermediate band solar cell research

International Nuclear Information System (INIS)

Cuadra, L.; Marti, A.; Luque, A.

2004-01-01

The intermediate band solar cell is a theoretical concept with the potential for exceeding the performance of conventional single-gap solar cells. This novel photovoltaic converter bases its superior theoretical efficiency over single-gap solar cells by enhancing its photogenerated current, via the two-step absorption of sub-band gap photons, without reducing its output voltage. This is achieved through a material with an electrically isolated and partially filled intermediate band located within a higher forbidden gap. This material is commonly named intermediate band material. This paper centres on summarising the present status of intermediate band solar cell research. A number of attempts, which aim to implement the intermediate band concept, are being followed: the direct engineering of the intermediate band material, its implementation by means of quantum dots and the highly porous material approach. Among other sub-band gap absorbing proposals, there is a renewed interest on the impurity photovoltaic effect, the quantum well solar cells and the particularly promising proposal for the use of up- and down-converters

Band excitation method applicable to scanning probe microscopy

Science.gov (United States)

Jesse, Stephen [Knoxville, TN; Kalinin, Sergei V [Knoxville, TN

2010-08-17

Methods and apparatus are described for scanning probe microscopy. A method includes generating a band excitation (BE) signal having finite and predefined amplitude and phase spectrum in at least a first predefined frequency band; exciting a probe using the band excitation signal; obtaining data by measuring a response of the probe in at least a second predefined frequency band; and extracting at least one relevant dynamic parameter of the response of the probe in a predefined range including analyzing the obtained data. The BE signal can be synthesized prior to imaging (static band excitation), or adjusted at each pixel or spectroscopy step to accommodate changes in sample properties (adaptive band excitation). An apparatus includes a band excitation signal generator; a probe coupled to the band excitation signal generator; a detector coupled to the probe; and a relevant dynamic parameter extractor component coupled to the detector, the relevant dynamic parameter extractor including a processor that performs a mathematical transform selected from the group consisting of an integral transform and a discrete transform.

Amniotic band syndrome: A clinical brief

Directory of Open Access Journals (Sweden)

Dasaradha Ramireddy Malireddy

2017-01-01

Full Text Available Amniotic band syndrome (ABS results from bands of amnion entangling fetal parts. They may manifest as constriction rings or complex congenital anomalies resulting in stillbirth. Karyotyping is important for exclusion of inherited disorders and proper counseling. Two case reports one stillbirth and the other with constriction ring of fingers and mild hydronephrosis are presented. The aim of this paper is to make awareness and stress the need for doing thorough work-up in all cases of constriction bands.

Absorption band Q model for the earth

International Nuclear Information System (INIS)

Anderson, D.L.; Given, J.W.

1982-01-01

Body wave, surface wave, and normal mode data are used to place constraints on the frequency dependence of Q in the mantle. With a simple absorption band model it is possible to satisfy the shear sensitive data over a broad frequency range. The quality factor Q/sub s/(ω) is proportional to ω/sup α/ in the band and to ω and ω -1 at higher and lower frequencies, respectively, as appropriate for a relaxation mechanism with a spectrum of relaxation time. The parameters of the band are Q(min) = 80, α = 0.15, and width, 5 decades. The center of the band varies from 10 1 seconds in the upper mantle, to 1.6 x 10 3 seconds in the lower mantle. The shift of the band with depth is consistent with the expected effects of temperature, pressure and stress. High Q, regions of the mantle are attributed to a shift of the absorption band to longer periods. To satisfy the gravest fundamental spheroidal modes and the ScS data, the absorption band must shift back into the short-period seismic band at the base of the mantle. This may be due to a high temperature gradient or high shear stresses. A preliminary attempt is also made to specify bulk dissipation in the mantle and core. Specific features of the absorption band model are low Q in the body wave band at both the top and the base of the mantle, low Q for long-period body waves in the outer core, an inner core Q 2 that increases with period, and low Q/sub p//Q/sub s/ at short periods in the middle mantel. The short-period Q/sub s/ increases rapidly at 400 km and is relatively constant from this depth to 2400 km. The deformational Q of the earth at a period of 14 months is predicted to be 463

Thermoelectric band engineering: The role of carrier scattering

Science.gov (United States)

Witkoske, Evan; Wang, Xufeng; Lundstrom, Mark; Askarpour, Vahid; Maassen, Jesse

2017-11-01

Complex electronic band structures, with multiple valleys or bands at the same or similar energies, can be beneficial for thermoelectric performance, but the advantages can be offset by inter-valley and inter-band scattering. In this paper, we demonstrate how first-principles band structures coupled with recently developed techniques for rigorous simulation of electron-phonon scattering provide the capabilities to realistically assess the benefits and trade-offs associated with these materials. We illustrate the approach using n-type silicon as a model material and show that intervalley scattering is strong. This example shows that the convergence of valleys and bands can improve thermoelectric performance, but the magnitude of the improvement depends sensitively on the relative strengths of intra- and inter-valley electron scattering. Because anisotropy of the band structure also plays an important role, a measure of the benefit of band anisotropy in the presence of strong intervalley scattering is presented.

Infrared radiation parameterizations for the minor CO2 bands and for several CFC bands in the window region

Science.gov (United States)

Kratz, David P.; Chou, Ming-Dah; Yan, Michael M.-H.

1993-01-01

Fast and accurate parameterizations have been developed for the transmission functions of the CO2 9.4- and 10.4-micron bands, as well as the CFC-11, CFC-12, and CFC-22 bands located in the 8-12-micron region. The parameterizations are based on line-by-line calculations of transmission functions for the CO2 bands and on high spectral resolution laboratory measurements of the absorption coefficients for the CFC bands. Also developed are the parameterizations for the H2O transmission functions for the corresponding spectral bands. Compared to the high-resolution calculations, fluxes at the tropopause computed with the parameterizations are accurate to within 10 percent when overlapping of gas absorptions within a band is taken into account. For individual gas absorption, the accuracy is of order 0-2 percent. The climatic effects of these trace gases have been studied using a zonally averaged multilayer energy balance model, which includes seasonal cycles and a simplified deep ocean. With the trace gas abundances taken to follow the Intergovernmental Panel on Climate Change Low Emissions 'B' scenario, the transient response of the surface temperature is simulated for the period 1900-2060.

CdSe/CdTe interface band gaps and band offsets calculated using spin-orbit and self-energy corrections

Energy Technology Data Exchange (ETDEWEB)

Ribeiro, M. [Centro de Pesquisas Avancadas Wernher von Braun, Av. Alice de Castro P.N. Mattosinho 301, CEP 13098-392 Campinas, SP (Brazil); Ferreira, L.G. [Departamento de Fisica dos Materiais e Mecanica, Instituto de Fisica, Universidade de Sao Paulo, 05315-970 Sao Paulo, SP (Brazil); Fonseca, L.R.C. [Center for Semiconductor Components, State University of Campinas, R. Pandia Calogeras 90, 13083-870 Campinas, SP (Brazil); Ramprasad, R. [Department of Chemical, Materials and Biomolecular Engineering, Institute of Materials Science, University of Connecticut, 97 North Eagleville Road, Storrs, CT 06269 (United States)

2012-09-20

We performed ab initio calculations of the electronic structures of bulk CdSe and CdTe, and their interface band alignments on the CdSe in-plane lattice parameters. For this, we employed the LDA-1/2 self-energy correction scheme to obtain corrected band gaps and band offsets. Our calculations include the spin-orbit effects for the bulk cases, which have shown to be of importance for the equilibrium systems and are possibly degraded in these strained semiconductors. Therefore, the SO showed reduced importance for the band alignment of this particular system. Moreover, the electronic structure calculated along the transition region across the CdSe/CdTe interface shows an interesting non-monotonic variation of the band gap in the range 0.8-1.8 eV, which may enhance the absorption of light for corresponding frequencies at the interface between these two materials in photovoltaic applications.

The Novel Microwave Stop-Band Filter

Directory of Open Access Journals (Sweden)

R. E. Chernobrovkin

2008-01-01

Full Text Available The stop-band filter with the new band-rejection element is proposed. The element is a coaxial waveguide with the slot in the centre conductor. In the frame of this research, the numerical and experimental investigations of the amplitude-frequency characteristics of the filter are carried out. It is noted that according to the slot parameters the two typical resonances (half-wave and quarter-wave can be excited. The rejection band of the single element is defined by the width, depth, and dielectric filling of the slot. Fifth-order Chebyshev filter utilizing the aforementioned element is also synthesized, manufactured, and tested. The measured and simulated results are in good agreement. The experimental filter prototype exhibits the rejection band 0.86 GHz at the level −40 dB.

Deep space propagation experiments at Ka-band

Science.gov (United States)

Butman, Stanley A.

1990-01-01

Propagation experiments as essential components of the general plan to develop an operational deep space telecommunications and navigation capability at Ka-band (32 to 35 GHz) by the end of the 20th century are discussed. Significant benefits of Ka-band over the current deep space standard X-band (8.4 GHz) are an improvement of 4 to 10 dB in telemetry capacity and a similar increase in radio navigation accuracy. Propagation experiments are planned on the Mars Observer Mission in 1992 in preparation for the Cassini Mission to Saturn in 1996, which will use Ka-band in the search for gravity waves as well as to enhance telemetry and navigation at Saturn in 2002. Subsequent uses of Ka-band are planned for the Solar Probe Mission and the Mars Program.

128Xe Lifetime Measurement Using the Coulex-Plunger Technique in Inverse Kinematics

International Nuclear Information System (INIS)

Konstantinopoulos, T.; Lagoyannis, A.; Harissopulos, S.; Dewald, A.; Rother, W.; Ilie, G.; Jones, P.; Rakhila, P.; Greenlees, P.; Grahn, T.; Julin, R.; Balabanski, D. L.

2008-01-01

The lifetimes of the lowest collective yrast and non-yrast states in 128 Xe were measured in a Coulomb excitation experiment using the recoil distance method (RDM) in inverse kinematics. Hereby, the Cologne plunger apparatus was employed together with the JUROGAM spectrometer. Excited states in 128 Xe were populated using a 128 Xe beam impinging on a nat Fe target with E( 128 Xe)≅525 MeV. Recoils were detected by means of an array of solar cells placed at forward angles. Recoil-gated γ-spectra were measured at different plunger distances

128Xe Lifetime Measurement Using the Coulex-Plunger Technique in Inverse Kinematics

Science.gov (United States)

Konstantinopoulos, T.; Lagoyannis, A.; Harissopulos, S.; Dewald, A.; Rother, W.; Ilie, G.; Jones, P.; Rakhila, P.; Greenlees, P.; Grahn, T.; Julin, R.; Balabanski, D. L.

2008-05-01

The lifetimes of the lowest collective yrast and non-yrast states in 128Xe were measured in a Coulomb excitation experiment using the recoil distance method (RDM) in inverse kinematics. Hereby, the Cologne plunger apparatus was employed together with the JUROGAM spectrometer. Excited states in 128Xe were populated using a 128Xe beam impinging on a natFe target with E(128Xe)~525 MeV. Recoils were detected by means of an array of solar cells placed at forward angles. Recoil-gated γ-spectra were measured at different plunger distances.

Dosimetry of narrow band UVB treatments

International Nuclear Information System (INIS)

Goode, D.H.; Mannering, D.M.

1996-01-01

Full text: For many years psoriasis has been treated with broad band UVB lamps. These lamps have a bell shaped spectrum which peaks at 305 nm and extends from 280 nm to 350 nm. However research with monochromatic UV radiation has shown that wavelengths between 300 nm and 320 nm are the most efficacious for clearing psoriasis while wavelengths below 305 nm are most effective for producing the undesirable side effect of erythema (sunburn). In response to these findings Philips developed a narrow band UVB tube in which a large fraction of the output was confined to a narrow peak (bandwidth 2.5 nm) situated at 311 nm. Christchurch Hospital replaced broad band UVB with narrow band treatments in August 1995 and as this required UV exposures to be substantially increased new protocols had to be developed. Three aspects needed to be addressed. These were translating the dose from broad band to narrow band for current patients, determining the initial dose for new patients and developing a formula for increasing subsequent exposures to both types of patient. To translate doses the spectral irradiance (μW/cm 2 /nm) that would fall on the patient was measured in both the old broad band and the new narrow band treatment units and from this UV doses were calculated. All doses were expressed in mJ/cm 2 of unweighted UV over the range 250 nm to 400 nm. The erythemal effectiveness of the two units were compared by using the CIE 1987 curve to express doses in terms of the equivalent exposure of monochromatic 297 nm radiation. It was found that an exposure of 3.96 mJ/cm 2 from the broad band FS40 tubes and 12.79 mJ/cm 2 from the narrow band TL/01 tubes were both equivalent to 1.00 mJ/cm 2 of monochromatic 297 nm radiation so when transferring patients all broad band doses needed to be increased by a factor of 3.2. Before transferring any patients this factor was confirmed by conducting two minimal erythema dose (MED) tests on a normal subject, one in each unit. For new patients a

Band-engineering of TiO2 as a wide-band gap semiconductor using organic chromophore dyes

Science.gov (United States)

Wahyuningsih, S.; Kartini, I.; Ramelan, A. H.; Saputri, L. N. M. Z.; Munawaroh, H.

2017-07-01

Bond-engineering as applied to semiconductor materials refers to the manipulation of the energy bands in order to control charge transfer processes in a device. When the device in question is a photoelectrochemical cell, the charges affected by drift become the focus of the study. The ideal band gap of semiconductors for enhancement of photocatalyst activity can be lowered to match with visible light absorption and the location of conduction Band (CB) should be raised to meet the reducing capacity. Otherwise, by the addition of the chromofor organic dyes, the wide-band gab can be influences by interacation resulting between TiO2 surface and the dyes. We have done the impruvisation wide-band gap of TiO2 by the addition of organic chromophore dye, and the addition of transition metal dopand. The TiO2 morphology influence the light absorption as well as the surface modification. The organic chromophore dye was syntesized by formation complexes compound of Co(PAR)(SiPA)(PAR)= 4-(2-piridylazoresorcinol), SiPA = Silyl propil amine). The result showed that the chromophore groups adsorbed onto TiO2 surface can increase the visible light absorption of wide-band gab semiconductor. Initial absorption of a chromophore will affect light penetration into the material surfaces. The use of photonic material as a solar cell shows this phenomenon clearly from the IPCE (incident photon to current conversion efficiency) measurement data. Organic chromophore dyes of Co(PAR)(SiPA) exhibited the long wavelength absorption character compared to the N719 dye (from Dyesol).

Band structures in near spherical 138Ce

Science.gov (United States)

Bhattacharjee, T.; Chanda, S.; Bhattacharyya, S.; Basu, S. K.; Bhowmik, R. K.; Das, J. J.; Pramanik, U. Datta; Ghugre, S. S.; Madhavan, N.; Mukherjee, A.; Mukherjee, G.; Muralithar, S.; Singh, R. P.

2009-06-01

The high spin states of N=80138Ce have been populated in the fusion evaporation reaction 130Te( 12C, 4n) 138Ce at E=65 MeV. The γ transitions belonging to various band structures were detected and characterized using an array of five Clover Germanium detectors. The level scheme has been established up to a maximum spin and excitation energy of 23 ℏ and 9511.3 keV, respectively, by including 53 new transitions. The negative parity ΔI=1 band, developed on the 6536.3 keV 15 level, has been conjectured to be a magnetic rotation band following a semiclassical analysis and comparing the systematics of similar bands in the neighboring nuclei. The said band is proposed to have a four quasiparticle configuration of [πgh]⊗[. Other band structures are interpreted in terms of multi-quasiparticle configurations, based on Total Routhian Surface (TRS) calculations. For the low and medium spin states, a shell model calculation using a realistic two body interaction has been performed using the code OXBASH.

Observation of band gaps in the gigahertz range and deaf bands in a hypersonic aluminum nitride phononic crystal slab

Science.gov (United States)

Gorisse, M.; Benchabane, S.; Teissier, G.; Billard, C.; Reinhardt, A.; Laude, V.; Defaÿ, E.; Aïd, M.

2011-06-01

We report on the observation of elastic waves propagating in a two-dimensional phononic crystal composed of air holes drilled in an aluminum nitride membrane. The theoretical band structure indicates the existence of an acoustic band gap centered around 800 MHz with a relative bandwidth of 6.5% that is confirmed by gigahertz optical images of the surface displacement. Further electrical measurements and computation of the transmission reveal a much wider attenuation band that is explained by the deaf character of certain bands resulting from the orthogonality of their polarization with that of the source.

Identical bands in Ba-Dy, N < 104 space

International Nuclear Information System (INIS)

Mittal, H.M.; Vidya Devi; Gupta, J.B.

2008-01-01

The recognition of the existence of identical bands, in even-even, odd-even and odd-odd nuclei, in normal deformed bands and superdeformed bands has become the subject of great interest in recent years. Here the search have been taken for such bands for the normal deformed, even-Z, even-N nuclei of Ba and Dy for 82< N<104 major shell space

New Kronig-Penney equation emphasizing the band edge conditions

International Nuclear Information System (INIS)

Szmulowicz, Frank

2008-01-01

The Kronig-Penney problem is a textbook example for discussing band dispersions and band gap formation in periodic layered media. For example, in photonic crystals, the behaviour of bands next to the band edges is important for further discussions of such effects as inhibited light emission, slow light and negative index of refraction. However, the standard Kronig-Penney equation does not explicitly state the band edge conditions. This paper derives a new solution for the Kronig-Penney problem that explicitly displays the band edge conditions as well as contains all other essential physics of band formation. Therefore, the present exposition should show the student that the band edge conditions are not simply special cases of the familiar Kronig-Penney equation but, instead, are an integral part of the band theory. For the computationally minded student, the new equation is particularly convenient for calculating the positions of closely spaced band edges. The present results can be taught alongside the Kronig-Penney equation in advanced undergraduate or beginning graduate quantum mechanics, solid state theory and photonics courses dealing with wave propagation through periodic layered media

Search for positive parity bands in 117Xe

International Nuclear Information System (INIS)

Liu, Z.; Sun, X.; Zhou, X.; Lei, X.; Zhang, Y.; Jin, H.; Pan, Q.; Guo, Y.; Chen, X.; Luo, Y.; Wen, S.; Yuan, G.; Yang, C.; Luo, W.; Chen, Y.S.; Xing, Z.; Chen, X.Q.

1995-01-01

Excited states of 117 Xe were populated via the reaction 28 Si+ 92 Mo at 100-120MeV. More than 40 new γ-transitions and three new positive parity bands have been observed by means of in-beam γ-ray spectroscopy. The previously known νh 11/2 bands were confirmed, and the νg 7/2 favored band was extended up to 47/2 + in which two bandcrossings have been observed at hω=0.33 and 0.44MeV, respectively. The band structures have been discussed by means of TRS and CSM calculations. A newly observed rotational band consisting of five γ-transitions has been considered as the πh 11/2 band of 117 Cs. ((orig.))

Resonant enhancement of band-to-band tunneling in in-plane MoS2/WS2 heterojunctions

Science.gov (United States)

Kuroda, Tatsuya; Mori, Nobuya

2018-04-01

The band-to-band (BTB) tunneling current J through in-plane MoS2/WS2 heterojunctions is calculated by the nonequilibrium Green function method combined with tight-binding approximation. Types A and B of band configurations are considered. For type-A (type-B) heterojunctions, a potential notch exists (or is absent) at the heterointerface. Both type-A and type-B MoS2/WS2 heterojunctions can support a higher BTB current than MoS2 and WS2 homojunctions. For type-A heterojunctions, the resonant enhancement of J occurs resulting in a significantly higher BTB tunneling current.

ANALISIS TIPOGRAFI PADA LOGOTYPE BAND FORGOTTEN

Directory of Open Access Journals (Sweden)

Atang Riyan Isnandar

2016-12-01

Full Text Available Abstrak Forgotten merupakan band asal kota Bandung yang beraliran death metal. Band ini telah memiliki beberapa album yang cukup sukses. Salah satu faktor yang turut berperan penting dalam album-album Forgotten adalah desain sampul album. Sampul album merupakan identitas dan pesan dari musik yang dibawakan oleh Forgotten. Dalam sampul album, terdapat salah satu elemen visual yaitu Tipografi. Salah satu peran tipografi dalam sampul album Forgotten adalah sebagai logotype dari band. Yang menarik, dari lima album yang telah dirilis Forgotten yaitu “Future Syndrome” (1997, “Obsesi Mati” (2000, “Tuhan Telah Mati” (2001, “Tiga Angka Enam” (2003 dan “Laras Perlaya” (2011 adalah tampilan logotype band yang selalu berbeda. Perubahan logotype Forgotten disebabkan oleh beberapa faktor seperti adanya perubahan selera, transformasi musik dan pergantian personil yang dialami oleh band Forgotten. Perubahan ini berakibat pada munculnya kesan visual yang berbeda-beda dari masing-masing logotype di setiap sampul albumnya. Apalagi logotype band dengan genre death metal memiliki kecendrungan yang unik, dekoratif, bahkan sulit untuk dibaca. Oleh karena itu untuk mengetahui kesan visual yang dimunculkan oleh setiap logotype akan dilakukan penelitian dengan pendekatan tipografi. Tujuan dari penelitian ini adalah selain untuk mengetahui perubahan logotype dari kelima sampul album yang telah dirilis oleh Forgotten juga ingin mengetahui kesan visual terhadap tipografi terkait dengan prinsip kejelasan (legibility, keterbacaan (readability dan kemampuannya untuk dilihat pada jarak tertentu (visibility. Kata Kunci: Sampul Album, Tipografi, Logotype, Forgotten Abstract Forgotten is a band from Bandung, the death metal genre. The band has had some fairly successful album. One of important factor in albums Forgotten is the album cover design. The album cover are the identity and the message of the music performed by the Forgotten. In the cover of the album

Report from the banding lab

Science.gov (United States)

Tautin, J.

1995-01-01

Mr. Tautin reported on the seemingly everchanging structure of biological science units within the Interior Department. Current Congressional proposals would either change the name of the Bird Banding Lab's parent agency or make it part of the Geological Survey. The current Congress has not looked favorably on science budgets within the Interior Department, and the Banding Lab's budget is being squeezed ever tighter.

Superdeformed bands in 130Ce

International Nuclear Information System (INIS)

Paul, E.S.; Semple, A.T.; Boston, A.J.; Joss, D.T.; Nolan, P.J.; Shepherd, S.L.

1997-01-01

Four superdeformed bands have been assigned to 130 Ce following a high-statistics γ-ray study using the EUROGAM II spectrometer. The strongest band exhibits two distinct backbends which, in one scenario, may be interpreted as crossings between high-j N = 6 neutron orbitals (νi 13/2 ) and low-j N = 4 orbitals (νd 3/2 ) in an unpaired system. (author)

Nuclear spectroscopic studies in 162Yb

International Nuclear Information System (INIS)

Behrens, H.

1980-01-01

The decay of the highly excited 162 Yb nuclei formed in the reaction 150 Sm( 16 O,4n) 162 Yb to the ground state was studied using different gamma detectors and an electron spectrometer, a so called mini-orange. The isotope 162 Yb was moreover produced and spectroscoped by the beta-decay of 162 Lu. For the identification of decay cascades, which were passed after the fusion, and for the determination of the multipolarity of the contributing energy transitions a series of experiments took place: The excitation functions and the angular distributions of the emitted gamma radiation was measured, the conversion coefficients of important transitions were determined, and coincidence events between two detectors occasionally were registrated and analyzed. In the beta decay measurement an assignment of gamma transitions to 162 Yb followed due to the lifetime, under which they occured. The found states of 162 Yb upto spins of 22 h/2π and excitation energies above 5 MeV belong to five rotational bands. The yrast band shows a weak backbending. Corresponding to their spins and parities the bands can be reduced to intrinsic excitation of two quasineutrons. The analysis of the beta-decay of 162 Lu, which takes place from three states in 162 Lu, leads to the lowest levels of the gamma-vibrational band and the band head of the beta band. The microscopic interpretation of the rotational bands and the description of the backbending behaviour are as the interpretation of the states involved at the beta decay in agreement with experimental and theoretical results for neighbouring ytterbium isotopes. (orig.) [de

Ferritin associates with marginal band microtubules

International Nuclear Information System (INIS)

Infante, Anthony A.; Infante, Dzintra; Chan, M.-C.; How, P.-C.; Kutschera, Waltraud; Linhartova, Irena; Muellner, Ernst W.; Wiche, Gerhard; Propst, Friedrich

2007-01-01

We characterized chicken erythrocyte and human platelet ferritin by biochemical studies and immunofluorescence. Erythrocyte ferritin was found to be a homopolymer of H-ferritin subunits, resistant to proteinase K digestion, heat stable, and contained iron. In mature chicken erythrocytes and human platelets, ferritin was localized at the marginal band, a ring-shaped peripheral microtubule bundle, and displayed properties of bona fide microtubule-associated proteins such as tau. Red blood cell ferritin association with the marginal band was confirmed by temperature-induced disassembly-reassembly of microtubules. During erythrocyte differentiation, ferritin co-localized with coalescing microtubules during marginal band formation. In addition, ferritin was found in the nuclei of mature erythrocytes, but was not detectable in those of bone marrow erythrocyte precursors. These results suggest that ferritin has a function in marginal band formation and possibly in protection of the marginal band from damaging effects of reactive oxygen species by sequestering iron in the mature erythrocyte. Moreover, our data suggest that ferritin and syncolin, a previously identified erythrocyte microtubule-associated protein, are identical. Nuclear ferritin might contribute to transcriptional silencing or, alternatively, constitute a ferritin reservoir

Lunar Noise-Temperature Increase Measurements at S-Band, X-Band, and Ka-Band Using a 34-Meter-Diameter Beam-Waveguide Antenna

Science.gov (United States)

Morabito, D. D.

2006-08-01

The Moon radiates energy at infrared and microwave wavelengths, in addition to reflecting sunlight at optical wavelengths. As a result, an antenna pointed at or near the Moon will cause an increase in receiver noise temperature that needs to be accounted for in telemetry, radio science, or ranging link budgets. The Deep Space Network may be required to use its antennas in future lunar robotic or human missions, and thus it is important to understand the nature of this temperature increase as a function of observing frequency, lunar phase, and angular offset of the antenna beam from the center of the lunar disk. This article quantifies such a set of measurements acquired at DSS 13, a 34-m-diameter research and development beam-waveguide antenna located at Goldstone, California, at three different telecommunication frequencies, S-band (2.3 GHz), X-band (8.4 GHz), and Ka-band (32 GHz), over a wide range of lunar phase, for both disk-centered and limb-centered positions of the antenna beam.

Ultra wide band antennas

CERN Document Server

Begaud, Xavier

2013-01-01

Ultra Wide Band Technology (UWB) has reached a level of maturity that allows us to offer wireless links with either high or low data rates. These wireless links are frequently associated with a location capability for which ultimate accuracy varies with the inverse of the frequency bandwidth. Using time or frequency domain waveforms, they are currently the subject of international standards facilitating their commercial implementation. Drawing up a complete state of the art, Ultra Wide Band Antennas is aimed at students, engineers and researchers and presents a summary of internationally recog

Band head spin assignment of superdeformed bands in Hg isotopes through power index formula

Science.gov (United States)

Sharma, Honey; Mittal, H. M.

2018-05-01

The power index formula has been used to obtain the band head spin (I 0) of all the superdeformed (SD) bands in Hg isotopes. A least squares fitting approach is used. The root mean square deviations between the determined and the observed transition energies are calculated by extracting the model parameters using the power index formula. Whenever definite spins are available, the determined and the observed transition energies are in accordance with each other. The computed values of dynamic moment of inertia J (2) obtained by using the power index formula and its deviation with the rotational frequency is also studied. Excellent agreement is shown between the calculated and the experimental results for J (2) versus the rotational frequency. Hence, the power index formula works very well for all the SD bands in Hg isotopes expect for 195Hg(2, 3, 4).

First-principles determination of band-to-band electronic transition energies in cubic and hexagonal AlGaInN alloys

Directory of Open Access Journals (Sweden)

F. L. Freitas

2016-08-01

Full Text Available We provide approximate quasiparticle-corrected band gap energies for quaternary cubic and hexagonal AlxGayIn1–x–yN semiconductor alloys, employing a cluster expansion method to account for the inherent statistical disorder of the system. Calculated values are compared with photoluminescence measurements and discussed within the currently accepted model of emission in these materials by carrier localization. It is shown that bowing parameters are larger in the cubic phase, while the range of band gap variation is bigger in the hexagonal one. Experimentally determined transition energies are mostly consistent with band-to-band excitations.

First-principles determination of band-to-band electronic transition energies in cubic and hexagonal AlGaInN alloys

Energy Technology Data Exchange (ETDEWEB)

Freitas, F. L., E-mail: felipelopesfreitas@gmail.com; Marques, M.; Teles, L. K. [Grupo de Materiais Semicondutores e Nanotecnologia, Instituto Tecnológico de Aeronáutica, 12228-900 São José dos Campos, SP (Brazil)

2016-08-15

We provide approximate quasiparticle-corrected band gap energies for quaternary cubic and hexagonal Al{sub x}Ga{sub y}In{sub 1–x–y}N semiconductor alloys, employing a cluster expansion method to account for the inherent statistical disorder of the system. Calculated values are compared with photoluminescence measurements and discussed within the currently accepted model of emission in these materials by carrier localization. It is shown that bowing parameters are larger in the cubic phase, while the range of band gap variation is bigger in the hexagonal one. Experimentally determined transition energies are mostly consistent with band-to-band excitations.

A Compact UWB Band-Pass Filter Using Embedded Circular Slot Structures for Improved Upper Stop-band Performance

DEFF Research Database (Denmark)

Shen, Ming; Ren, Jian; Mikkelsen, Jan Hvolgaard

2016-01-01

structures into the ring resonator. This is different from conventional designs using cascaded bandstop/low-pass filters for stop-band response suppression, which usually leads to big circuit sizes. And hence the proposed approach can reduce the circuit size significantly. A prototype filter with a compact...... size (13.6 mm×6.75 mm) has been implemented for experimental validation. The measured results show a −3 dB frequency band from 3.4 GHz to 11.7 GHz and > 20 dB upper stop-band suppression from 12.5 GHz to 20GHz....

Gain flattened L-band EDFA based on upgraded C-band EDFA using forward ASE pumping in an EDF section

DEFF Research Database (Denmark)

Buxens Azcoaga, Alvaro Juan; Poulsen, Henrik Nørskov; Clausen, Anders

2000-01-01

A novel method is presented for implementing an L-band erbium doped fibre amplifier (EDFA) making use of forward amplified spontaneous emission pumping, from a commercially available c-band EDFA, in an erbium doped fibre. Tuning of the length of erbium doped fibre enables a flat gain characteristic...... to be obtained with a low noise figure over the entire L-band window....

A Compact Printed Quadruple Band-Notched UWB Antenna

Directory of Open Access Journals (Sweden)

Xiaoyin Li

2013-01-01

Full Text Available A novel compact coplanar waveguide- (CPW- fed ultrawideband (UWB printed planar volcano-smoke antenna (PVSA with four band-notches for various wireless applications is proposed and demonstrated. The low-profile antenna consists of a C-shaped parasitic strip to generate a notched band at 8.01~8.55 GHz for the ITU band, two C-shaped slots, and an inverted U-shaped slot etched in the radiator patch to create three notched bands at 5.15~5.35 GHz, 5.75~5.85 GHz, and 7.25~7.75 GHz for filtering the WLAN and X-band satellite signals. Simulated and measured results both confirm that the proposed antenna has a broad bandwidth of 3.1~12 GHz with VSWR < 2 and good omnidirectional radiation patterns with four notched-bands.

Surface correlation effects in two-band strongly correlated slabs.

Science.gov (United States)

Esfahani, D Nasr; Covaci, L; Peeters, F M

2014-02-19

Using an extension of the Gutzwiller approximation for an inhomogeneous system, we study the two-band Hubbard model with unequal band widths for a slab geometry. The aim is to investigate the mutual effect of individual bands on the spatial distribution of quasi-particle weight and charge density, especially near the surface of the slab. The main effect of the difference in band width is the presence of two different length scales corresponding to the quasi-particle profile of each band. This is enhanced in the vicinity of the critical interaction of the narrow band where an orbitally selective Mott transition occurs and a surface dead layer forms for the narrow band. For the doped case, two different regimes of charge transfer between the surface and the bulk of the slab are revealed. The charge transfer from surface/center to center/surface depends on both the doping level and the average relative charge accumulated in each band. Such effects could also be of importance when describing the accumulation of charges at the interface between structures made of multi-band strongly correlated materials.

Confidence bands for inverse regression models

International Nuclear Information System (INIS)

Birke, Melanie; Bissantz, Nicolai; Holzmann, Hajo

2010-01-01

We construct uniform confidence bands for the regression function in inverse, homoscedastic regression models with convolution-type operators. Here, the convolution is between two non-periodic functions on the whole real line rather than between two periodic functions on a compact interval, since the former situation arguably arises more often in applications. First, following Bickel and Rosenblatt (1973 Ann. Stat. 1 1071–95) we construct asymptotic confidence bands which are based on strong approximations and on a limit theorem for the supremum of a stationary Gaussian process. Further, we propose bootstrap confidence bands based on the residual bootstrap and prove consistency of the bootstrap procedure. A simulation study shows that the bootstrap confidence bands perform reasonably well for moderate sample sizes. Finally, we apply our method to data from a gel electrophoresis experiment with genetically engineered neuronal receptor subunits incubated with rat brain extract

Simultaneous confidence bands for the integrated hazard function

OpenAIRE

Dudek, Anna; Gocwin, Maciej; Leskow, Jacek

2006-01-01

The construction of the simultaneous confidence bands for the integrated hazard function is considered. The Nelson--Aalen estimator is used. The simultaneous confidence bands based on bootstrap methods are presented. Two methods of construction of such confidence bands are proposed. The weird bootstrap method is used for resampling. Simulations are made to compare the actual coverage probability of the bootstrap and the asymptotic simultaneous confidence bands. It is shown that the equal--tai...

Study of the structure of the transition nuclei 152Dy, 154Dy and 156Er at high angular momentum

International Nuclear Information System (INIS)

Azgui, F.

1985-01-01

Measurements of feeding times of high spin yrast states in 152 Dy, 154 Dy and 156 Er were utilized to obtain information about possible spin dependent shape changes. Feeding times as well as lifetimes were determined with the recoil distance technique. In 152 Dy only long feeding times (> 10 ps) could be identified, indicating that the aligned-particle yrast states are fed through configuration of similar character, with little direct population from collective cascade in the continuum region. In 154 Dy discrete states with I ≤ 30 have lifetimes which are characteristically collective, whereas the preyrast cascade exhibit both fast ( 10 ps) feeding components. The latter imply a change with increasing spin from collective to aligned-particle character, signalling a prolate to oblate shape transition. In 156 Er the yrast states up to spin 20 ℎ were found to be collective. These levels are fed, however, from long-lived high spin states, causing time delay up to ∼ 100 ps, the existence of which is interpreted as a signature for an oblate shape at high spin [fr

Observations of banding in first-year Arctic sea ice

Science.gov (United States)

Cole, David M.; Eicken, Hajo; Frey, Karoline; Shapiro, Lewis H.

2004-08-01

Horizontal banding features, alternating dark and bright horizontal bands apparent in ice cores and stratigraphic cross sections have long been observed in first-year sea ice and are frequently associated with bands of high and low brine or gas porosity. Observations on the land-fast ice near Barrow, Alaska, in recent years have revealed particularly striking banding patterns and prompted a study of their macroscopic and microscopic characteristics. The banding patterns are quantified from photographs of full-depth sections of the ice, and examples are presented from the Chukchi Sea and Elson Lagoon. Statistics on band spacing are presented, and the growth records for three seasons are employed to estimate their time of formation. These data provide insight into the periodicity of the underlying phenomena. Micrographs are used to examine the microstructural variations associated with various banding features and to quantify the geometry of the constituent brine inclusions associated with high- and low-porosity bands. The micrography revealed that the area fraction of brine inclusions varied by a factor of nearly 3 through the more pronounced high- and low-porosity bands. Vertical micrographs obtained shortly after the materials' removal from the ice sheet showed that significantly larger inclusions form abruptly at the start of the high-porosity bands and frequently terminate abruptly at the end of the band. Crystallographic observations indicated that the high-porosity bands supported the nucleation and growth of crystals having substantially different orientations from the very well aligned columnar structure that characterized the bulk of the sheet.

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.

Transistorized wide band pulse amplifier; Amplificateur d'impulsions a large bande et a transistors

Energy Technology Data Exchange (ETDEWEB)

Girard, J; Savinelli, H [Commissariat a l' Energie Atomique, Saclay (France).Centre d' Etudes Nucleaires; Hazoni, Y [Atomic Energy Commission (Israel)

1960-07-01

A simple wide band amplifier is described below, having a stability better than 1{sup 0}/00 deg{sup -1} centigrade, a current gain of 10{sup 3}, bandwidth of 30 MHz, and a signal to noise current ratio of about 100. This amplifier has been studied to answer the necessity of a fast transistor head amplifier for nuclear detectors, having in mind pile up and overloading problems. (author) [French] Un amplificateur simple, a large bande, est decrit ci-apres, il a une stabilite meilleure que le 0/00 par degre centigrade, un gain en courant de 10{sup 3} une largeur de bande de 30 MHz, et un rapport signal sur bruit en courant d'environ 100. Cet amplificateur a ete etudie pour repondre a la necessite de l'amplification des impulsions provenant de detecteurs nucleaires, ayant a l'esprit les problemes d'empilement et de saturation. (auteur)

Model Development for MODIS Thermal Band Electronic Crosstalk

Science.gov (United States)

Chang, Tiejun; Wu, Aisheng; Geng, Xu; Li, Yonghonh; Brinkman, Jake; Keller, Graziela; Xiong, Xiaoxiong

2016-01-01

MODerate-resolution Imaging Spectroradiometer (MODIS) has 36 bands. Among them, 16 thermal emissive bands covering a wavelength range from 3.8 to 14.4 m. After 16 years on-orbit operation, the electronic crosstalk of a few Terra MODIS thermal emissive bands developed substantial issues that cause biases in the EV brightness temperature measurements and surface feature contamination. The crosstalk effects on band 27 with center wavelength at 6.7 m and band 29 at 8.5 m increased significantly in recent years, affecting downstream products such as water vapor and cloud mask. The crosstalk effect is evident in the near-monthly scheduled lunar measurements, from which the crosstalk coefficients can be derived. The development of an alternative approach is very helpful for independent verification.In this work, a physical model was developed to assess the crosstalk impact on calibration as well as in Earth view brightness temperature retrieval. This model was applied to Terra MODIS band 29 empirically to correct the Earth brightness temperature measurements. In the model development, the detectors nonlinear response is considered. The impact of the electronic crosstalk is assessed in two steps. The first step consists of determining the impact on calibration using the on-board blackbody (BB). Due to the detectors nonlinear response and large background signal, both linear and nonlinear coefficients are affected by the crosstalk from sending bands. The second step is to calculate the effects on the Earth view brightness temperature retrieval. The effects include those from affected calibration coefficients and the contamination of Earth view measurements. This model links the measurement bias with crosstalk coefficients, detector non-linearity, and the ratio of Earth measurements between the sending and receiving bands. The correction of the electronic cross talk can be implemented empirically from the processed bias at different brightness temperature. The implementation

47 CFR 90.1213 - Band plan.

Science.gov (United States)

2010-10-01

... 47 Telecommunication 5 2010-10-01 2010-10-01 false Band plan. 90.1213 Section 90.1213 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) SAFETY AND SPECIAL RADIO SERVICES PRIVATE LAND... § 90.1213 Band plan. The following channel center frequencies are permitted to be aggregated for...

Integrated wide-band low-background amplifiers

International Nuclear Information System (INIS)

Il'yushchenko, I.I.

1980-01-01

Ways of increasing stability and reproduction of characteristics of wide-band integral amplifiers that would to the least extent increase their background noises, are discussed. Considered are some certain flowsheets of integral wide-band amplifiers with low background noise of foreign production which differ from one another by construction of inlet cascades as well as by the applied feedback type. The principal flowsheets of the amplifiers and their main performances are presented. The analysis of the data obtained has revealed that microcircuits made of cascades with a common emitter and local combined feedback are most wide-band among all the considered microcircuits [ru

SPECTRUM AGGREGATION WITH OPTIMAL MULTI-BAND SCHEDULING

DEFF Research Database (Denmark)

Mihovska, Albena D.

2010-01-01

This paper seeks to explore the integration of spectrum and network resource management functionalities to the benefit of achieving higher performance and capacity gains in an International Mobile Telecommunications-Advanced (IMT-A) scenario. In particular, we investigate the allocation of users...... over two frequency bands (i.e., 2 GHz and 5 GHz) for a single operator scenario. The same type of Radio Access Technology (RAT) is considered for both frequency bands. It is assumed that the operator has gained access to a non-shared 2 GHz band and to part (or all) of the frequency pool band at 5 GHz....... The performance gain is analyzed in terms of higher data throughput. The performance is heavily dependent on the channel quality for each user in the considered bands which, in turn, is a function of the path loss and the distance from the Base Station (BS). The operator will have relevant improvements when...

Excited negative parity bands in 160Yb

Science.gov (United States)

Saha, A.; Bhattacharjee, T.; Curien, D.; Dedes, I.; Mazurek, K.; Banerjee, S. R.; Rajbanshi, S.; Bisoi, A.; de Angelis, G.; Bhattacharya, Soumik; Bhattacharyya, S.; Biswas, S.; Chakraborty, A.; Das Gupta, S.; Dey, B.; Goswami, A.; Mondal, D.; Pandit, D.; Palit, R.; Roy, T.; Singh, R. P.; Saha Sarkar, M.; Saha, S.; Sethi, J.

2018-03-01

Negative parity rotational bands in {} 70160Yb{}90 nucleus have been studied. They were populated in the 148Sm(16O, 4n)160Yb reaction at 90 MeV. The gamma-coincidence data have been collected using Indian National Gamma Array composed of twenty Compton suppressed clover germanium (Ge) detectors. Double gating on triple gamma coincidence data were selectively used to develop the decay scheme for these negative parity bands by identifying and taking care of the multiplet transitions. The even- and odd-spin negative parity bands in 160Yb have been studied by comparing the reduced transition probability ratios with the similar bands in neighbouring even-even rare earth nuclei. It is concluded that the concerned odd-spin and even-spin bands are not signature partners and that their structures are compatible with those of the ‘pear-shape’ and ‘pyramid-shape’ oscillations, respectively, the octupole shapes superposed with the quadrupole shape of the ground-state.

Dipole Bands in 196Hg

International Nuclear Information System (INIS)

Lawrie, J. J.; Lawrie, E. A.; Newman, R. T.; Sharpey-Schafer, J. F.; Smit, F. D.; Msezane, B.; Benatar, M.; Mabala, G. K.; Mutshena, K. P.; Federke, M.; Mullins, S. M.; Ncapayi, N. J.; Vymers, P.

2011-01-01

High spin states in 196 Hg have been populated in the 198 Pt(α,6n) reaction at 65 MeV and the level scheme has been extended. A new dipole band has been observed and a previously observed dipole has been confirmed. Excitation energies, spins and parities of these bands were determined from DCO ratio and linear polarization measurements. Possible quasiparticle excitations responsible for these structures are discussed.

Development of softcopy environment for primary color banding visibility assessment

Science.gov (United States)

Min, Byungseok; Pizlo, Zygmunt; Allebach, Jan P.

2008-01-01

Fine-pitch banding is one of the most unwanted artifacts in laser electrophotographic (EP) printers. It is perceived as a quasiperiodic fluctuation in the process direction. Therefore, it is essential for printer vendors to know how banding is perceived by humans in order to improve print quality. Monochrome banding has been analyzed and assessed by many researchers; but there is no literature that deals with the banding of color laser printers as measured from actual prints. The study of color banding is complicated by the fact that the color banding signal is physically defined in a three-dimensional color space, while banding perception is described in a one-dimensional sense such as more banding or less banding. In addition, the color banding signal arises from the independent contributions of the four primary colorant banding signals. It is not known how these four distinct signals combine to give rise to the perception of color banding. In this paper, we develop a methodology to assess the banding visibility of the primary colorant cyan based on human visual perception. This is our first step toward studying the more general problem of color banding in combinations of two or more colorants. According to our method, we print and scan the cyan test patch, and extract the banding profile as a one dimensional signal so that we can freely adjust the intensity of banding. Thereafter, by exploiting the pulse width modulation capability of the laser printer, the extracted banding profile is used to modulate a pattern consisting of periodic lines oriented in the process direction, to generate extrinsic banding. This avoids the effect of the halftoning algorithm on the banding. Furthermore, to conduct various banding assessments more efficiently, we also develop a softcopy environment that emulates a hardcopy image on a calibrated monitor, which requires highly accurate device calibration throughout the whole system. To achieve the same color appearance as the hardcopy

A comparative cepstral based analysis of simulated and measured S-band and X-band radar Doppler spectra of human motion

CSIR Research Space (South Africa)

Van Eeden, WD

2015-10-01

Full Text Available targets. It is also shown that, whereas the motion of most body parts of a human target can be observed in the X-band data, only the main torso sway can be observed at S-band. This implies that X-band data is well suited to cepstrum based human motion...

Introduction to the viewpoint set on shear bands

International Nuclear Information System (INIS)

Hutchinson, J.W.

1984-01-01

Recent work aimed at improving our understanding of shear banding and flow localization as modes of deformation and failure is summarized in the six viewpoint articles which follow. For the most part, the emphasis here is on the observation and analysis of shear banding in metals, but active efforts are also underway to understand the role of shear bands in the deformation and failure of soils and rocks. There is a tendency to regard shear bands as a failure mode, as indeed they often are. But extensive straining under highly constrained conditions such as rolling can give rise to profuse flow localization into shear bands which can be regarded as microscopic in the sense that their extent is on the scale of the grains rather than the overall dimensions of the block of material being deformed. Hatherly and Malin describe in detail the observation of such bands and emphasize that they should be considered as a mode of deformation under these circumstances. They relate the formation of the bands to microstructural aspects and discuss their role in the development of recrystallization textures. It will be clear from reading the articles in this viewpoint set that the beginnings of a quantitative theory of shear banding is in place. Continued progress will require parallel developments in constitutive theory and experimental observation. Moreover, basic questions remain to be explored related to the spatial development of the shear bands, their mutual interaction, their development into a failure mode, and how these are influenced by factors such as overall deformational constraint, rate of straining, and temperature

Band structures in fractal grading porous phononic crystals

Science.gov (United States)

Wang, Kai; Liu, Ying; Liang, Tianshu; Wang, Bin

2018-05-01

In this paper, a new grading porous structure is introduced based on a Sierpinski triangle routine, and wave propagation in this fractal grading porous phononic crystal is investigated. The influences of fractal hierarchy and porosity on the band structures in fractal graidng porous phononic crystals are clarified. Vibration modes of unit cell at absolute band gap edges are given to manifest formation mechanism of absolute band gaps. The results show that absolute band gaps are easy to form in fractal structures comparatively to the normal ones with the same porosity. Structures with higher fractal hierarchies benefit multiple wider absolute band gaps. This work provides useful guidance in design of fractal porous phononic crystals.

The Noisiness of Low Frequency Bands of Noise

Science.gov (United States)

Lawton, B. W.

1975-01-01

The relative noisiness of low frequency 1/3-octave bands of noise was examined. The frequency range investigated was bounded by the bands centered at 25 and 200 Hz, with intensities ranging from 50 to 95 db (SPL). Thirty-two subjects used a method of adjustment technique, producing comparison band intensities as noisy as 100 and 200 Hz standard bands at 60 and 72 db. The work resulted in contours of equal noisiness for 1/3-octave bands, ranging in intensity from approximately 58 to 86 db (SPL). These contours were compared with the standard equal noisiness contours; in the region of overlap, between 50 and 200 Hz, the agreement was good.

Exciter For X-Band Transmitter And Receiver

Science.gov (United States)

Johns, Carl E.

1989-01-01

Report describes developmental X-band exciter for X-band uplink subsystem of Deep Space Network. X-band transmitter-exciting signal expected to have fractional frequency stability of 5.2 X 10 to negative 15th power during 1,000-second integration period. Generates coherent test signals for S- and X-band Block III translator of Deep Space Network, Doppler-reference signal for associated Doppler-extractor system, first-local-oscillator signal for associated receiver, and reference signal for associated ranging subsystem. Tests of prototype exciter show controlling and monitoring and internal phase-correcting loops perform according to applicable design criteria. Measurements of stability of frequency and of single-sideband noise spectral density of transmitter-exciting signal made subsequently.

Band-to-Band Tunneling-Dominated Thermo-Enhanced Field Electron Emission from p-Si/ZnO Nanoemitters.

Science.gov (United States)

Huang, Zhizhen; Huang, Yifeng; Xu, Ningsheng; Chen, Jun; She, Juncong; Deng, Shaozhi

2018-06-13

Thermo-enhancement is an effective way to achieve high performance field electron emitters, and enables the individually tuning on the emission current by temperature and the electron energy by voltage. The field emission current from metal or n-doped semiconductor emitter at a relatively lower temperature (i.e., current saturation was observed in the thermo-enhanced field emission measurements. The emission current density showed about ten-time enhancement (from 1.31 to 12.11 mA/cm 2 at 60.6 MV/m) by increasing the temperature from 323 to 623 K. The distinctive performance did not agree with the interband excitation mechanism but well-fit to the band-to-band tunneling model. The strong thermo-enhancement was proposed to be benefit from the increase of band-to-band tunneling probability at the surface portion of the p-Si/ZnO nanojunction. This work provides promising cathode for portable X-ray tubes/panel, ionization vacuum gauges and low energy electron beam lithography, in where electron-dose control at a fixed energy is needed.

The design and application of a multi-band IR imager

Science.gov (United States)

Li, Lijuan

2018-02-01

Multi-band IR imaging system has many applications in security, national defense, petroleum and gas industry, etc. So the relevant technologies are getting more and more attention in rent years. As we know, when used in missile warning and missile seeker systems, multi-band IR imaging technology has the advantage of high target recognition capability and low false alarm rate if suitable spectral bands are selected. Compared with traditional single band IR imager, multi-band IR imager can make use of spectral features in addition to space and time domain features to discriminate target from background clutters and decoys. So, one of the key work is to select the right spectral bands in which the feature difference between target and false target is evident and is well utilized. Multi-band IR imager is a useful instrument to collect multi-band IR images of target, backgrounds and decoys for spectral band selection study at low cost and with adjustable parameters and property compared with commercial imaging spectrometer. In this paper, a multi-band IR imaging system is developed which is suitable to collect 4 spectral band images of various scenes at every turn and can be expanded to other short-wave and mid-wave IR spectral bands combination by changing filter groups. The multi-band IR imaging system consists of a broad band optical system, a cryogenic InSb large array detector, a spinning filter wheel and electronic processing system. The multi-band IR imaging system's performance is tested in real data collection experiments.

Electron band theory 1952-1962

International Nuclear Information System (INIS)

Lomer, W.M.

1980-01-01

Work undertaken by the Theoretical Physics Division between 1952 and 1965 to obtain an understanding of electrons in metals, with uranium and the actinides and the structurally-important transition metals as the main targets is examined. A main result of that period was a conviction that the majority of the physical properties of all metals, except the 4f rare-earth series and the actinides beyond uranium, were dominated by band effects which could be described well enough for most purposes by simple one-electron calculations with simple self-consistent fields. The period from 1960 on showed increasingly clearly the necessity of incorporating relativistic spin-orbit coupling terms in the heavy metals, and some 'local exchange field' correction to the fields close to nuclei. The problems of the non-local interaction of spins - highly important for alloy theory and for antiferromagnetic instability -required the evolution of computers large enough to produce wave-functions at all wave-vectors for all bands so that the susceptibility at arbitrary wave-vector could be computed. This work has not proved to be very illuminating so far, and much interest again focusses today on heuristic arguments that give qualitative descriptions of band structures, such as canonical d-bands to account for crystal structure. (UK)

A programmable ultra-low noise X-band exciter.

Science.gov (United States)

MacMullen, A; Hoover, L R; Justice, R D; Callahan, B S

2001-07-01

A programmable ultra-low noise X-band exciter has been developed using commercial off-the-shelf components. Its phase noise is more than 10 dB below the best available microwave synthesizers. It covers a 7% frequency band with 0.1-Hz resolution. The X-band output at +23 dBm is a combination of signals from an X-band sapphire-loaded cavity oscillator (SLCO), a low noise UHF frequency synthesizer, and special-purpose frequency translation and up-conversion circuitry.

Multiple band structure in 156Er

International Nuclear Information System (INIS)

Sunyar, A.W.; Der Mateosian, E.; Kistner, O.C.; Johnson, A.; Lumpkin, A.H.; Thieberger, P.

1976-01-01

The 142 Nd( 18 O,4n) 156 Er reaction at 90-95 MeV was used to study 156 Er high-spin states to spin 24. In addition to the background ground-state band, two well developed off-spin side bands, one of each parity, were observed. (Auth.)

Gastric band tubing-related complication during pregnancy.

Science.gov (United States)

Ongso, Yuni F; Beh, Han N

2017-11-01

In the past few decades, laparoscopic adjustable gastric banding is one of the most common bariatric procedures performed to treat morbid obesity. Device-related complication such as connection-tubing problem is rare. Here we present a case of gastric band tubing complication during pregnancy. This case illustrates the need to maintain high index of suspicion of gastric band device-related complication during pregnancy and early referral for bariatric surgical assessment is recommended.

47 CFR 15.714 - TV bands database administration fees.

Science.gov (United States)

2010-10-01

... 47 Telecommunication 1 2010-10-01 2010-10-01 false TV bands database administration fees. 15.714... Television Band Devices § 15.714 TV bands database administration fees. (a) A TV bands database administrator may charge a fee for provision of lists of available channels to fixed and personal/portable TVBDs and...

Reduction in pediatric identification band errors: a quality collaborative.

Science.gov (United States)

Phillips, Shannon Connor; Saysana, Michele; Worley, Sarah; Hain, Paul D

2012-06-01

Accurate and consistent placement of a patient identification (ID) band is used in health care to reduce errors associated with patient misidentification. Multiple safety organizations have devoted time and energy to improving patient ID, but no multicenter improvement collaboratives have shown scalability of previously successful interventions. We hoped to reduce by half the pediatric patient ID band error rate, defined as absent, illegible, or inaccurate ID band, across a quality improvement learning collaborative of hospitals in 1 year. On the basis of a previously successful single-site intervention, we conducted a self-selected 6-site collaborative to reduce ID band errors in heterogeneous pediatric hospital settings. The collaborative had 3 phases: preparatory work and employee survey of current practice and barriers, data collection (ID band failure rate), and intervention driven by data and collaborative learning to accelerate change. The collaborative audited 11377 patients for ID band errors between September 2009 and September 2010. The ID band failure rate decreased from 17% to 4.1% (77% relative reduction). Interventions including education of frontline staff regarding correct ID bands as a safety strategy; a change to softer ID bands, including "luggage tag" type ID bands for some patients; and partnering with families and patients through education were applied at all institutions. Over 13 months, a collaborative of pediatric institutions significantly reduced the ID band failure rate. This quality improvement learning collaborative demonstrates that safety improvements tested in a single institution can be disseminated to improve quality of care across large populations of children.

Visible bands of ammonia: band strengths, curves of growth, and the spatial distribution of ammonia on Jupiter

International Nuclear Information System (INIS)

Lutz, B.L.; Owen, T.

1980-01-01

We report room-temperature laboratory studies of the 5520 A (6ν 1 ) and 6475 A (5ν 1 ) bands of self-broadened ammonia at column densities ranging from 1.7--435.7 meter-amagats (m-am). Detailed equivalent-width measurements at 24 different pressure-pathlength combinations corresponding to four pressures between 44 and 689 torr and pathlengths between 32 and 512 m are used to determin curves of growth and integrated band strengths. The band strengths for the 6ν 1 and 5ν 1 overtones are 5520 A: S=0.096 +- 0.005 cm -1 (m-am) -1 and 6475 A: S=0.63 +- 0.03 cm -1 (m-am) -1 , respectively.Using these band strengths and curves of growth, we analyze new spatially resolved spectra of Jupiter showing a nonhomogeneous distribution of ammonia in the Jovian atmosphere. The observed variations in the CH 4 /NH 3 mixing ratio are interpreted as evidence of altitude-dependent depletion of ammonia in the atmosphere

Structural Evolution of a Warm Frontal Precipitation Band During GCPEx

Science.gov (United States)

Colle, Brian A.; Naeger, Aaron; Molthan, Andrew; Nesbitt, Stephen

2015-01-01

A warm frontal precipitation band developed over a few hours 50-100 km to the north of a surface warm front. The 3-km WRF was able to realistically simulate band development, although the model is somewhat too weak. Band genesis was associated with weak frontogenesis (deformation) in the presence of weak potential and conditional instability feeding into the band region, while it was closer to moist neutral within the band. As the band matured, frontogenesis increased, while the stability gradually increased in the banding region. Cloud top generating cells were prevalent, but not in WRF (too stable). The band decayed as the stability increased upstream and the frontogenesis (deformation) with the warm front weakened. The WRF may have been too weak and short-lived with the band because too stable and forcing too weak (some micro issues as well).

New Kronig-Penney Equation Emphasizing the Band Edge Conditions

Science.gov (United States)

Szmulowicz, Frank

2008-01-01

The Kronig-Penney problem is a textbook example for discussing band dispersions and band gap formation in periodic layered media. For example, in photonic crystals, the behaviour of bands next to the band edges is important for further discussions of such effects as inhibited light emission, slow light and negative index of refraction. However,…

Photodensitometric tracing of Mach bands and its significance

International Nuclear Information System (INIS)

Yoo, Shi Joon; Cho, Kyung Sik; Kang, Heung Sik; Cho, Byung Jae

1984-01-01

Mach bands, a visual phenomenon resulting from lateral inhibitory impulses in the retina, are recognized as lucent or dense lines at the borders of different radiographic densities. A number of clinical situations have been described in which Mach bands may cause difficulty in radiographic diagnosis. Photodensitometric measurement of the film can differentiate the true change in film density from the Mach band which is an optical illusion. Authors present several examples of photodensitometric tracings of Mach bands, with the brief review of the mechanism of their production

Energies and transition probabilities from the full solution of nuclear quadrupole-octupole model

International Nuclear Information System (INIS)

Strecker, M.; Lenske, H.; Minkov, N.

2013-01-01

A collective model of nuclear quadrupole-octupole vibrations and rotations, originally restricted to a coherent interplay between quadrupole and octupole modes, is now developed for application beyond this restriction. The eigenvalue problem is solved by diagonalizing the unrestricted Hamiltonian in the basis of the analytic solution obtained in the case of the coherent-mode assumption. Within this scheme the yrast alternating-parity band is constructed by the lowest eigenvalues having the appropriate parity at given angular momentum. Additionally we include the calculation of transition probabilities which are fitted with the energies simultaneously. As a result we obtain a unique set of parameters. The obtained model parameters unambiguously determine the shape of the quadrupole-octupole potential. From the resulting wave functions quadrupole deformation expectation values are calculated which are found to be in agreement with experimental values. (author)

Abrikosov flux-lines in two-band superconductors with mixed dimensionality

International Nuclear Information System (INIS)

Tanaka, K; Eschrig, M

2009-01-01

We study vortex structure in a two-band superconductor, in which one band is ballistic and quasi-two-dimensional (2D), and the other is diffusive and three-dimensional (3D). A circular cell approximation of the vortex lattice within the quasiclassical theory of superconductivity is applied to a recently developed model appropriate for such a two-band system (Tanaka et al 2006 Phys. Rev. B 73 220501(R); Tanaka et al 2007 Phys. Rev. B 75 214512). We assume that superconductivity in the 3D diffusive band is 'weak', i.e. mostly induced, as is the case in MgB 2 . Hybridization with the 'weak' 3D diffusive band has significant and intriguing influence on the electronic structure of the 'strong' 2D ballistic band. In particular, the Coulomb repulsion and the diffusivity in the 'weak' band enhance suppression of the order parameter and enlargement of the vortex core by magnetic field in the 'strong' band, resulting in reduced critical temperature and field. Moreover, increased diffusivity in the 'weak' band can result in an upward curvature of the upper critical field near the transition temperature. A particularly interesting feature found in our model is the appearance of additional bound states at the gap edge in the 'strong' ballistic band, which are absent in the single-band case. Furthermore, coupling with the 'weak' diffusive band leads to reduced bandgaps and van Hove singularities of energy bands of the vortex lattice in the 'strong' ballistic band. We find these intriguing features for parameter values appropriate for MgB 2 .

Identical high- K three-quasiparticle rotational bands

Energy Technology Data Exchange (ETDEWEB)

Kaur, Harjeet; Singh, Pardeep [Guru Nanak Dev University, Department of Physics, Amritsar (India)

2016-12-15

A comprehensive study of high-K three-quasiparticle rotational bands in odd-A nuclei indicates the similarity in γ-ray energies and dynamic moment of inertia I{sup (2)}. The extent of the identicality between the rotational bands is evaluated by using the energy factor method. For nuclei pairs exhibiting identical bands, the average relative change in the dynamic moment of inertia I{sup (2)} is also determined. The identical behaviour shown by these bands is attributed to the interplay of nuclear structure parameters: deformation and the pairing correlations. Also, experimental trend of the I(ℎ) vs. ℎω (MeV) plot for these nuclei pairs is shown to be in agreement with Tilted-Axis Cranking (TAC) model calculations. (orig.)

Silicone rubber band for laparoscopic tubal sterilization.

Science.gov (United States)

Ansari, A H; Sealey, R M; Gay, J W; Kang, I

1977-12-01

In 1974, Yoon and associates (Am J Obstet Gynecol 120:132, 1974) described a new approach in which laparoscopic tubal occlusion was accomplished by utilizing the silicone rubber band technique. Recognizing the great advantages of the new technique in eliminating potential thermal injury associated with electrocoagulation, the authors have utilized the Yoon silicone rubber band technique in these institutions over the past 20 months. Thus far the procedure has been performed in 304 patients without any major complications. In the hope of eliminating and/or reducing possible pregnancy-failure rates, in 110 cases. In addition to application of the silicone band, the tube within the band was transected with non-electrical Seigler biopsy forceps. This, we believe, should provide an interesting long-term comparative study.

Anomalies in the 1D Anderson model: Beyond the band-centre and band-edge cases

Science.gov (United States)

Tessieri, L.; Izrailev, F. M.

2018-03-01

We consider the one-dimensional Anderson model with weak disorder. Using the Hamiltonian map approach, we analyse the validity of the random-phase approximation for resonant values of the energy, E = 2 cos(πr) , with r a rational number. We expand the invariant measure of the phase variable in powers of the disorder strength and we show that, contrary to what happens at the centre and at the edges of the band, for all other resonant energies the leading term of the invariant measure is uniform. When higher-order terms are taken into account, a modulation of the invariant measure appears for all resonant values of the energy. This implies that, when the localisation length is computed within the second-order approximation in the disorder strength, the Thouless formula is valid everywhere except at the band centre and at the band edges.

Controllable Absorption and Dispersion Properties of an RF-driven Five-Level Atom in a Double-Band Photonic-Band-Gap Material

International Nuclear Information System (INIS)

Ding Chunling; Li Jiahua; Yang Xiaoxue

2011-01-01

The probe absorption-dispersion spectra of a radio-frequency (RF)-driven five-level atom embedded in a photonic crystal are investigated by considering the isotropic double-band photonic-band-gap (PBG) reservoir. In the model used, the two transitions are, respectively, coupled by the upper and lower bands in such a PBG material, thus leading to some curious phenomena. Numerical simulations are performed for the optical spectra. It is found that when one transition frequency is inside the band gap and the other is outside the gap, there emerge three peaks in the absorption spectra. However, for the case that two transition frequencies lie inside or outside the band gap, the spectra display four absorption profiles. Especially, there appear two sharp peaks in the spectra when both transition frequencies exist inside the band gap. The influences of the intensity and frequency of the RF-driven field on the absorptive and dispersive response are analyzed under different band-edge positions. It is found that a transparency window appears in the absorption spectra and is accompanied by a very steep variation of the dispersion profile by adjusting system parameters. These results show that the absorption-dispersion properties of the system depend strongly on the RF-induced quantum interference and the density of states (DOS) of the PBG reservoir. (electromagnetism, optics, acoustics, heat transfer, classical mechanics, and fluid dynamics)

Yrast excitations in 191Pb

International Nuclear Information System (INIS)

Fotiades, N.; Andreyev, A.

1997-01-01

Prompt, in-beam γ rays in coincidence with evaporation residues were measured in the 164,166 Er + 164 MeV 32 S reactions. A level scheme built on the 13/2 + isomer has been deduced from four transitions assigned to 191 Pb. The states in 191 Pb are interpreted in terms of a weak coupling of the odd i 13/2 neutron-hole to the spherical states in the even-mass 192 Pb core. (orig.). With 4 figs

Strain gradient drives shear banding in metallic glasses

Science.gov (United States)

Tian, Zhi-Li; Wang, Yun-Jiang; Chen, Yan; Dai, Lan-Hong

2017-09-01

Shear banding is a nucleation-controlled process in metallic glasses (MGs) involving multiple temporal-spatial scales, which hinders a concrete understanding of its structural origin down to the atomic scale. Here, inspired by the morphology of composite materials, we propose a different perspective of MGs as a hard particle-reinforced material based on atomic-scale structural heterogeneity. The local stable structures indicated by a high level of local fivefold symmetry (L5FS) act as hard "particles" which are embedded in the relatively soft matrix. We demonstrate this concept by performing atomistic simulations of shear banding in CuZr MG. A shear band is prone to form in a sample with a high degree of L5FS which is slowly quenched from the liquid. An atomic-scale analysis on strain and the structural evolution reveals that it is the strain gradient effect that has originated from structural heterogeneity that facilitates shear transformation zones (STZs) to mature shear bands. An artificial composite model with a high degree of strain gradient, generated by inserting hard MG strips into a soft MG matrix, demonstrates a great propensity for shear banding. It therefore confirms the critical role strain gradient plays in shear banding. The strain gradient effect on shear banding is further quantified with a continuum model and a mechanical instability analysis. These physical insights might highlight the strain gradient as the hidden driving force in transforming STZs into shear bands in MGs.

Micromachined millimeter-wave photonic band-gap crystals

International Nuclear Information System (INIS)

Oezbay, E.; Michel, E.; Tuttle, G.; Biswas, R.; Sigalas, M.; Ho, K.

1994-01-01

We have developed a new technique for fabricating three-dimensional photonic band-gap crystals. Our method utilizes an orderly stacking of micromachined (110) silicon wafers to build the periodic structure. A structure with a full three-dimensional photonic band gap centered near 100 GHz was measured, with experimental results in good agreement with theoretical predictions. This basic approach described should be extendable to build structures with photonic band-gap frequencies ranging from 30 GHz to 3 THz

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

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.

The 3 micron ice band

International Nuclear Information System (INIS)

Greenberg, J.M.; Bult, C.E.P.M. van de

1984-01-01

Ever since it was proposed that H 2 O could be a dominant constituent of interstellar grains, its detection, or lack thereof, has played a large role in theories of grains and their evolution. It now appears possible to provide a basic theoretical structure for the evolution of grains in molecular clouds based on current observational evidence and laboratory experiments on the ice band. Both band strengths and shapes can be reasonably predicted by grain models. (U.K.)

Laparoscopic gastric banding

Science.gov (United States)

... eat by making you feel full after eating small amounts of food. After surgery, your doctor can adjust the band ... You will feel full after eating just a small amount of food. The food in the small upper pouch will ...

Chiral topological excitons in a Chern band insulator

Science.gov (United States)

Chen, Ke; Shindou, Ryuichi

2017-10-01

A family of semiconductors called Chern band insulators are shown to host exciton bands with nonzero topological Chern integers and chiral exciton edge modes. Using a prototypical two-band Chern insulator model, we calculate a cross-correlation function to obtain the exciton bands and their Chern integers. The lowest exciton band acquires Chern integers such as ±1 and ±2 in the electronic Chern insulator phase. The nontrivial topology can be experimentally observed both by a nonlocal optoelectronic response of exciton edge modes and by a phase shift in the cross-correlation response due to the bulk mode. Our result suggests that magnetically doped HgTe, InAs/GaSb quantum wells, and (Bi,Sb)2Te3 thin films are promising candidates for a platform of topological excitonics.

K-Band Traveling-Wave Tube Amplifier

Science.gov (United States)

Force, Dale A.; Simons, Rainee N.; Peterson, Todd T.; Spitsen, Paul C.

2010-01-01

A new space-qualified, high-power, high-efficiency, K-band traveling-wave tube amplifier (TWTA) will provide high-rate, high-capacity, direct-to-Earth communications for science data and video gathered by the Lunar Reconnaissance Orbiter (LRO) during its mission. Several technological advances were responsible for the successful demonstration of the K-band TWTA.

Microbial processes in banded iron formation deposition

DEFF Research Database (Denmark)

Posth, Nicole; Konhauser, Kurt; Kappler, Andreas

2013-01-01

, remains unresolved. Evidence of an anoxic Earth with only localized oxic areas until the Great Oxidation Event ca 2·45 to 2·32 Ga makes the investigation of O2-independent mechanisms for banded iron formation deposition relevant. Recent studies have explored the long-standing proposition that Archean......Banded iron formations have been studied for decades, particularly regarding their potential as archives of the Precambrian environment. In spite of this effort, the mechanism of their deposition and, specifically, the role that microbes played in the precipitation of banded iron formation minerals...... banded iron formations may have been formed, and diagenetically modified, by anaerobic microbial metabolisms. These efforts encompass a wide array of approaches including isotope, ecophysiological and phylogeny studies, molecular and mineral marker analysis, and sedimentological reconstructions. Herein...

Building blocks of topological quantum chemistry: Elementary band representations

Science.gov (United States)

Cano, Jennifer; Bradlyn, Barry; Wang, Zhijun; Elcoro, L.; Vergniory, M. G.; Felser, C.; Aroyo, M. I.; Bernevig, B. Andrei

2018-01-01

The link between chemical orbitals described by local degrees of freedom and band theory, which is defined in momentum space, was proposed by Zak several decades ago for spinless systems with and without time reversal in his theory of "elementary" band representations. In a recent paper [Bradlyn et al., Nature (London) 547, 298 (2017), 10.1038/nature23268] we introduced the generalization of this theory to the experimentally relevant situation of spin-orbit coupled systems with time-reversal symmetry and proved that all bands that do not transform as band representations are topological. Here we give the full details of this construction. We prove that elementary band representations are either connected as bands in the Brillouin zone and are described by localized Wannier orbitals respecting the symmetries of the lattice (including time reversal when applicable), or, if disconnected, describe topological insulators. We then show how to generate a band representation from a particular Wyckoff position and determine which Wyckoff positions generate elementary band representations for all space groups. This theory applies to spinful and spinless systems, in all dimensions, with and without time reversal. We introduce a homotopic notion of equivalence and show that it results in a finer classification of topological phases than approaches based only on the symmetry of wave functions at special points in the Brillouin zone. Utilizing a mapping of the band connectivity into a graph theory problem, we show in companion papers which Wyckoff positions can generate disconnected elementary band representations, furnishing a natural avenue for a systematic materials search.

Detection Range Estimation of UV Spectral Band Laser Radar

Directory of Open Access Journals (Sweden)

V. A. Gorodnichev

2014-01-01

Full Text Available Recently, has come into existence an interest in the systems operating in the ultra-violet (UF band of wavelengths, which use other spectral information (coefficients of reflection or radiation in UF range about location objects, than laser systems in the visible, near or average infrared bands. Thus, a point is not only to receive additional (in another spectral range information on location objects. Laser radiation in the UF spectral band of 0.315 – 0.4 microns is safer than laser radiation with the wavelengths of 0.38 – 1.4 microns.The work presents a comparative estimation of the detection systems range of laser radars in the UV and visible spectral bands for the following wavelengths of radiation:- UF band: 0.266 microns (the fourth harmonic of YAG-laser activated by neodymium ions, 0.308 microns (the XeCl-excimer laser, 0.355 microns (the third harmonic of YAG-laser activated by neodymium ions;- visible band: 0.532 microns (the second harmonic of YAG-laser activated by neodymium ions.Results of calculations show that for the horizontal pathway in the terrestrial atmosphere at the selected radiation wavelengths a detection range is in the range of 2510m – 5690 m.The maximum range of detection corresponds to the visible spectral band. A sweep range decreases with transition to the UF band. This is caused by the fact that with transition to the UF band there is a rise of atmosphere attenuation (generally, because of absorption by ozone, this effect being smoothed by reducing background radiation.In the UF band a wavelength of 0.355 microns is the most acceptable. For this wavelength a detection range is about 1,5 times less (in comparison with the visible band of 0.532 microns. However, this is the much more eye-safe wavelength. With transition to the UV band a detection range decreases not that much and can be compensated by changing parameters of transmitting or receiving channels of laser radar.

Conservation of topological quantum numbers in energy bands

International Nuclear Information System (INIS)

Chang, L.N.; Liang, Y.

1988-01-01

Quantum systems described by parametrized Hamiltinians are studied in a general context. Within this context, the classification scheme of Avron-Seiler-Simon for non-degenerate energy bands is extended to cover general parameter spaces, whole their sum rule is generalized to cover cases with degenerate bands as well. Additive topological quantum numbers are defined, and these are shown to be conserved in energy band ''collisions''. The conservation laws dictate that when some invariants are non-vanishing, no energy gap can develop in a set of degenerate bands. This gives rise to a series of splitting rules

An efficient atomistic quantum mechanical simulation on InAs band-to-band tunneling field-effect transistors

Energy Technology Data Exchange (ETDEWEB)

Wang, Zhi [State Key Laboratory for Superlattices and Microstructures, Institute of Semiconductors, Chinese Academy of Sciences, P.O. Box 912, Beijing 100083 (China); Jiang, Xiang-Wei; Li, Shu-Shen [State Key Laboratory for Superlattices and Microstructures, Institute of Semiconductors, Chinese Academy of Sciences, P.O. Box 912, Beijing 100083 (China); Synergetic Innovation Center of Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei, Anhui 230026 (China); Wang, Lin-Wang, E-mail: lwwang@lbl.gov [Material Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States)

2014-03-24

We have presented a fully atomistic quantum mechanical simulation method on band-to-band tunneling (BTBT) field-effect transistors (FETs). Our simulation approach is based on the linear combination of bulk band method with empirical pseudopotentials, which is an atomist method beyond the effective-mass approximation or k.p perturbation method, and can be used to simulate real-size devices (∼10{sup 5} atoms) efficiently (∼5 h on a few computational cores). Using this approach, we studied the InAs dual-gate BTBT FETs. The I-V characteristics from our approach agree very well with the tight-binding non-equilibrium Green's function results, yet our method costs much less computationally. In addition, we have studied ways to increase the tunneling current and analyzed the effects of different mechanisms for that purpose.

An efficient atomistic quantum mechanical simulation on InAs band-to-band tunneling field-effect transistors

International Nuclear Information System (INIS)

Wang, Zhi; Jiang, Xiang-Wei; Li, Shu-Shen; Wang, Lin-Wang

2014-01-01

We have presented a fully atomistic quantum mechanical simulation method on band-to-band tunneling (BTBT) field-effect transistors (FETs). Our simulation approach is based on the linear combination of bulk band method with empirical pseudopotentials, which is an atomist method beyond the effective-mass approximation or k.p perturbation method, and can be used to simulate real-size devices (∼10 5 atoms) efficiently (∼5 h on a few computational cores). Using this approach, we studied the InAs dual-gate BTBT FETs. The I-V characteristics from our approach agree very well with the tight-binding non-equilibrium Green's function results, yet our method costs much less computationally. In addition, we have studied ways to increase the tunneling current and analyzed the effects of different mechanisms for that purpose

Band-selective filter in a zigzag graphene nanoribbon.

Science.gov (United States)

Nakabayashi, Jun; Yamamoto, Daisuke; Kurihara, Susumu

2009-02-13

Electric transport of a zigzag graphene nanoribbon through a steplike potential and a barrier potential is investigated by using the recursive Green's function method. In the case of the steplike potential, we demonstrate numerically that scattering processes obey a selection rule for the band indices when the number of zigzag chains is even; the electrons belonging to the "even" ("odd") bands are scattered only into the even (odd) bands so that the parity of the wave functions is preserved. In the case of the barrier potential, by tuning the barrier height to be an appropriate value, we show that it can work as the "band-selective filter", which transmits electrons selectively with respect to the indices of the bands to which the incident electrons belong. Finally, we suggest that this selection rule can be observed in the conductance by applying two barrier potentials.

Drosophila polytene chromosome bands formed by gene introns.

Science.gov (United States)

Zhimulev, I F; Boldyreva, L V; Demakova, O V; Poholkova, G V; Khoroshko, V A; Zykova, T Yu; Lavrov, S A; Belyaeva, E S

2016-01-01

Genetic organization of bands and interbands in polytene chromosomes has long remained a puzzle for geneticists. It has been recently demonstrated that interbands typically correspond to the 5'-ends of house-keeping genes, whereas adjacent loose bands tend to be composed of coding sequences of the genes. In the present work, we made one important step further and mapped two large introns of ubiquitously active genes on the polytene chromosome map. We show that alternative promoter regions of these genes map to interbands, whereas introns and coding sequences found between those promoters correspond to loose grey bands. Thus, a gene having its long intron "sandwiched" between to alternative promoters and a common coding sequence may occupy two interbands and one band in the context of polytene chromosomes. Loose, partially decompacted bands appear to host large introns.

Tensile-strain effect of inducing the indirect-to-direct band-gap transition and reducing the band-gap energy of Ge

Energy Technology Data Exchange (ETDEWEB)

Inaoka, Takeshi, E-mail: inaoka@phys.u-ryukyu.ac.jp; Furukawa, Takuro; Toma, Ryo; Yanagisawa, Susumu [Department of Physics and Earth Sciences, Faculty of Science, University of the Ryukyus, 1 Senbaru, Nishihara, Okinawa 903-0213 (Japan)

2015-09-14

By means of a hybrid density-functional method, we investigate the tensile-strain effect of inducing the indirect-to-direct band-gap transition and reducing the band-gap energy of Ge. We consider [001], [111], and [110] uniaxial tensility and (001), (111), and (110) biaxial tensility. Under the condition of no normal stress, we determine both normal compression and internal strain, namely, relative displacement of two atoms in the primitive unit cell, by minimizing the total energy. We identify those strain types which can induce the band-gap transition, and evaluate the critical strain coefficient where the gap transition occurs. Either normal compression or internal strain operates unfavorably to induce the gap transition, which raises the critical strain coefficient or even blocks the transition. We also examine how each type of tensile strain decreases the band-gap energy, depending on its orientation. Our analysis clearly shows that synergistic operation of strain orientation and band anisotropy has a great influence on the gap transition and the gap energy.

Development of axial asymmetry in the neutron-rich nucleus {sup 110}Mo

Energy Technology Data Exchange (ETDEWEB)

Watanabe, H., E-mail: hiroshi@ribf.riken.jp [RIKEN Nishina Center, 2-1 Hirosawa, Wako, Saitama 351-0198 (Japan); Yamaguchi, K.; Odahara, A. [Department of Physics, Osaka University, Machikaneyama-machi 1-1, Osaka 560-0043 Toyonaka (Japan); Sumikama, T. [Department of Physics, Faculty of Science and Technology, Tokyo University of Science, 2641 Yamazaki, Noda, Chiba (Japan); Nishimura, S. [RIKEN Nishina Center, 2-1 Hirosawa, Wako, Saitama 351-0198 (Japan); Yoshinaga, K. [Department of Physics, Faculty of Science and Technology, Tokyo University of Science, 2641 Yamazaki, Noda, Chiba (Japan); Li, Z. [RIKEN Nishina Center, 2-1 Hirosawa, Wako, Saitama 351-0198 (Japan); Miyashita, Y. [Department of Physics, Faculty of Science and Technology, Tokyo University of Science, 2641 Yamazaki, Noda, Chiba (Japan); Sato, K. [RIKEN Nishina Center, 2-1 Hirosawa, Wako, Saitama 351-0198 (Japan); Prochniak, L. [Institute of Physics, Maria Curie-Sklodowska University, pl. M. Curie-Sklodowskiej 1, 20-031 Lublin (Poland); Baba, H. [RIKEN Nishina Center, 2-1 Hirosawa, Wako, Saitama 351-0198 (Japan); Berryman, J.S. [Nuclear Science Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720 (United States); Blasi, N. [INFN, Sezione di Milano, via Celoria 16, I-20133 Milano (Italy); Bracco, A.; Camera, F. [INFN, Sezione di Milano, via Celoria 16, I-20133 Milano (Italy); Dipartimento di Fisica, Universita di Milano, via Celoria 16, I-20133 Milano (Italy); Chiba, J. [Department of Physics, Faculty of Science and Technology, Tokyo University of Science, 2641 Yamazaki, Noda, Chiba (Japan); Doornenbal, P. [RIKEN Nishina Center, 2-1 Hirosawa, Wako, Saitama 351-0198 (Japan); Go, S.; Hashimoto, T.; Hayakawa, S. [Center for Nuclear Study, University of Tokyo, Hirosawa 2-1, Wako, Saitama 351-0198 (Japan)

2011-10-19

The neutron-rich nucleus {sup 110}Mo has been investigated by means of {gamma}-ray spectroscopy following the {beta}-decay of {sup 110}Nb, produced using in-flight fission of a {sup 238}U beam at 345 MeV/nucleon at the RIBF facility. In addition to the ground-band members reported previously, spectroscopic information on the low-lying levels of the quasi-{gamma} band built on the second 2{sup +} state at 494 keV has been obtained for the first time. The experimental finding of the second 2{sup +} state being lower than the yrast 4{sup +} level suggests that axially-asymmetric {gamma} softness is substantially enhanced in this nucleus. The experimental results are compared with model calculations based on the general Bohr Hamiltonian method. The systematics of the low-lying levels in even-even A{approx}110 nuclei is discussed in comparison with that in the neutron-rich A{approx}190 region, by introducing the quantity E{sub S}/E(2{sub 1}{sup +}), E{sub S}=E(2{sub 2}{sup +})-E(4{sub 1}{sup +}), as a global signature of the structural evolution involving axial asymmetry.

Photonic band edge assisted spontaneous emission enhancement from all Er3+ 1-D photonic band gap structure

Science.gov (United States)

Chiasera, A.; Meroni, C.; Varas, S.; Valligatla, S.; Scotognella, F.; Boucher, Y. G.; Lukowiak, A.; Zur, L.; Righini, G. C.; Ferrari, M.

2018-06-01

All Er3+ doped dielectric 1-D Photonic Band Gap Structure was fabricated by rf-sputtering technique. The structure was constituted by of twenty pairs of SiO2/TiO2 alternated layers doped with Er3+ ions. The scanning electron microscopy was used to check the morphology of the structure. Transmission measurements put in evidence the stop band in the range 1500 nm-1950 nm. The photoluminescence measurements were obtained by optically exciting the sample and detecting the emitted light in the 1.5 μm region at different detection angles. Luminescence spectra and luminescence decay curves put in evidence that the presence of the stop band modify the emission features of the Er3+ ions.

Ka-band waveguide rotary joint

KAUST Repository

Yevdokymov, Anatoliy

2013-04-11

The authors present a design of a waveguide rotary joint operating in Ka-band with central frequency of 33 GHz, which also acts as an antenna mount. The main unit consists of two flanges with a clearance between them; one of the flanges has three circular choke grooves. Utilisation of three choke grooves allows larger operating clearance. Two prototypes of the rotary joint have been manufactured and experimentally studied. The observed loss is from 0.4 to 0.8 dB in 1.5 GHz band.

First experience with the InfiniBand interconnect

International Nuclear Information System (INIS)

Schwickerath, Ulrich; Heiss, Andreas

2004-01-01

A test cluster of dual Intel-Xeon processor server nodes has been equipped with 10 GBit/s InfiniBand interconnect. Capabilities of this new technique were tested and compared to Gigabit-Ethernet (GE) with respect to both High-Performance Computing (MPI-based parallel computing applications) and High-Throughput Computing (HTC). RFIO, a protocol for fast and efficient file transfers, has been ported to make immediate use of InfiniBand, utilizing the remote direct memory access (RDMA) capabilities of the InfiniBand hardware. The performance is compared to Gigabit-Ethernet

Band mixing in /sup 160/Dy

Energy Technology Data Exchange (ETDEWEB)

Hasiza, M L; Singh, K; Sahota, H S [Punjabi Univ., Patiala (India). Dept. of Physics

1982-11-01

The intensities of the gamma transitions in /sup 160/Dy have been measured precisely by a 45 cc Ge(Li) detector. Unequal quadrupole moments for the ground and gamma vibrational bands have been proposed in order to remove the inconsistencies in the values of band mixing parameter Z sub(gamma) for this doubly even deformed nucleus of /sup 160/Dy.

Spectral band selection for classification of soil organic matter content

Science.gov (United States)

Henderson, Tracey L.; Szilagyi, Andrea; Baumgardner, Marion F.; Chen, Chih-Chien Thomas; Landgrebe, David A.

1989-01-01

This paper describes the spectral-band-selection (SBS) algorithm of Chen and Landgrebe (1987, 1988, and 1989) and uses the algorithm to classify the organic matter content in the earth's surface soil. The effectiveness of the algorithm was evaluated comparing the results of classification of the soil organic matter using SBS bands with those obtained using Landsat MSS bands and TM bands, showing that the algorithm was successful in finding important spectral bands for classification of organic matter content. Using the calculated bands, the probabilities of correct classification for climate-stratified data were found to range from 0.910 to 0.980.

Ka Band Phase Locked Loop Oscillator Dielectric Resonator Oscillator for Satellite EHF Band Receiver

Directory of Open Access Journals (Sweden)

S. Coco

2008-01-01

Full Text Available This paper describes the design and fabrication of a Ka Band PLL DRO having a fundamental oscillation frequency of 19.250 GHz, used as local oscillator in the low-noise block of a down converter (LNB for an EHF band receiver. Apposite circuital models have been created to describe the behaviour of the dielectric resonator and of the active component used in the oscillator core. The DRO characterization and measurements have shown very good agreement with simulation results. A good phase noise performance is obtained by using a very high Q dielectric resonator.

Band structures in the nematic elastomers phononic crystals

Energy Technology Data Exchange (ETDEWEB)

Yang, Shuai [Department of Mechanics, School of Civil Engineering, Beijing Jiaotong University, Beijing 100044 (China); School of Civil Engineering and Architecture, Anyang Normal University, Anyang 455000 (China); Liu, Ying, E-mail: yliu5@bjtu.edu.cn [Department of Mechanics, School of Civil Engineering, Beijing Jiaotong University, Beijing 100044 (China); Liang, Tianshu [Department of Mechanics, School of Civil Engineering, Beijing Jiaotong University, Beijing 100044 (China)

2017-02-01

As one kind of new intelligent materials, nematic elastomers (NEs) represent an exciting physical system that combines the local orientational symmetry breaking and the entropic rubber elasticity, producing a number of unique physical phenomena. In this paper, the potential application of NEs in the band tuning is explored. The band structures in two kinds of NE phononic crystals (PCs) are investigated. Through changing NE intrinsic parameters, the influence of the porosity, director rotation and relaxation on the band structures in NE PCs are analyzed. This work is a meaningful try for application of NEs in acoustic field and proposes a new intelligent strategy in band turning.

Band structures in the nematic elastomers phononic crystals

International Nuclear Information System (INIS)

Yang, Shuai; Liu, Ying; Liang, Tianshu

2017-01-01

As one kind of new intelligent materials, nematic elastomers (NEs) represent an exciting physical system that combines the local orientational symmetry breaking and the entropic rubber elasticity, producing a number of unique physical phenomena. In this paper, the potential application of NEs in the band tuning is explored. The band structures in two kinds of NE phononic crystals (PCs) are investigated. Through changing NE intrinsic parameters, the influence of the porosity, director rotation and relaxation on the band structures in NE PCs are analyzed. This work is a meaningful try for application of NEs in acoustic field and proposes a new intelligent strategy in band turning.

Left regular bands of groups of left quotients

International Nuclear Information System (INIS)

El-Qallali, A.

1988-10-01

A semigroup S which has a left regular band of groups as a semigroup of left quotients is shown to be the semigroup which is a left regular band of right reversible cancellative semigroups. An alternative characterization is provided by using spinned products. These results are applied to the case where S is a superabundant whose set of idempotents forms a left normal band. (author). 13 refs

Band-to-band tunneling distance analysis in the heterogate electron–hole bilayer tunnel field-effect transistor

Energy Technology Data Exchange (ETDEWEB)

Padilla, J. L., E-mail: jose.padilladelatorre@epfl.ch [Nanoelectronic Devices Laboratory, École Polytechnique Fédérale de Lausanne, Lausanne CH-1015 (Switzerland); Departamento de Electrónica y Tecnología de los Computadores, Universidad de Granada, Avda. Fuentenueva s/n, 18071 Granada (Spain); Palomares, A. [Departamento de Matemática Aplicada, Universidad de Granada, Avda. Fuentenueva s/n, 18071 Granada (Spain); Alper, C.; Ionescu, A. M. [Nanoelectronic Devices Laboratory, École Polytechnique Fédérale de Lausanne, Lausanne CH-1015 (Switzerland); Gámiz, F. [Departamento de Electrónica y Tecnología de los Computadores, Universidad de Granada, Avda. Fuentenueva s/n, 18071 Granada (Spain)

2016-01-28

In this work, we analyze the behavior of the band-to-band tunneling distance between electron and hole subbands resulting from field-induced quantum confinement in the heterogate electron–hole bilayer tunnel field-effect transistor. We show that, analogously to the explicit formula for the tunneling distance that can be easily obtained in the semiclassical framework where the conduction and valence band edges are allowed states, an equivalent analytical expression can be derived in the presence of field-induced quantum confinement for describing the dependence of the tunneling distance on the body thickness and material properties of the channel. This explicit expression accounting for quantum confinement holds valid provided that the potential wells for electrons and holes at the top and bottom of the channel can be approximated by triangular profiles. Analytical predictions are compared to simulation results showing very accurate agreement.

Reliability of flipper-banded penguins as indicators of climate change.

Science.gov (United States)

Saraux, Claire; Le Bohec, Céline; Durant, Joël M; Viblanc, Vincent A; Gauthier-Clerc, Michel; Beaune, David; Park, Young-Hyang; Yoccoz, Nigel G; Stenseth, Nils C; Le Maho, Yvon

2011-01-13

In 2007, the Intergovernmental Panel on Climate Change highlighted an urgent need to assess the responses of marine ecosystems to climate change. Because they lie in a high-latitude region, the Southern Ocean ecosystems are expected to be strongly affected by global warming. Using top predators of this highly productive ocean (such as penguins) as integrative indicators may help us assess the impacts of climate change on marine ecosystems. Yet most available information on penguin population dynamics is based on the controversial use of flipper banding. Although some reports have found the effects of flipper bands to be deleterious, some short-term (one-year) studies have concluded otherwise, resulting in the continuation of extensive banding schemes and the use of data sets thus collected to predict climate impact on natural populations. Here we show that banding of free-ranging king penguins (Aptenodytes patagonicus) impairs both survival and reproduction, ultimately affecting population growth rate. Over the course of a 10-year longitudinal study, banded birds produced 41% [corrected] fewer chicks and had a survival rate 16 percentage points [corrected] lower than non-banded birds, demonstrating a massive long-term impact of banding and thus refuting the assumption that birds will ultimately adapt to being banded. Indeed, banded birds still arrived later for breeding at the study site and had longer foraging trips even after 10 years. One of our major findings is that responses of flipper-banded penguins to climate variability (that is, changes in sea surface temperature and in the Southern Oscillation index) differ from those of non-banded birds. We show that only long-term investigations may allow an evaluation of the impact of flipper bands and that every major life-history trait can be affected, calling into question the banding schemes still going on. In addition, our understanding of the effects of climate change on marine ecosystems based on flipper-band

Effects of the intrinsic layer width on the band-to-band tunneling current in p-i-n GaN-based avalanche photodiodes

International Nuclear Information System (INIS)

Wang, Ling; Bao, Xichang; Zhang, Wenjing; Li, Chao; Yuan, Yonggang; Xu, Jintong; Zhang, Yan; Li, Xiangyang

2009-01-01

Dark current is critical for GaN-based avalanche photodiodes because it significantly increases the noise current and limits the multiplication factor. It has been found that the band-to-band tunneling current is the dominant origin of the dark current for avalanche photodiodes at the onset of breakdown voltage. Experimentally, for GaN-based avalanche photodiodes with a thinner intrinsic layer, the dark current increases nearly exponentially with the applied voltage even at a lower bias voltage. In this paper, the intrinsic layer (i-layer) width of GaN-based avalanche photodiodes has been varied to study its effect on the band-to-band tunneling current. A widely used equation was used to calculate the band-to-band tunneling current of avalanche photodiodes with different i-layer widths (i-layer 0.1 µm, 0.2 µm and 0.4 µm). At −40 V, the band-to-band tunneling current significantly reduces by a magnitude of 10 −15 A with an increase in the i-layer width from 0.1 µm to 0.2 µm, and a magnitude of 10 −29 A with an increase in the i-layer width from 0.2 µm to 0.4 µm. Then, GaN-based avalanche photodiodes (i-layer 0.1 µm, 0.2 µm and 0.4 µm) with different-sized mesa were fabricated. Also, the measurement of dark current of all three different structures was performed, and their multiplication factors were given

47 CFR 18.303 - Prohibited frequency bands.

Science.gov (United States)

2010-10-01

... 47 Telecommunication 1 2010-10-01 2010-10-01 false Prohibited frequency bands. 18.303 Section 18.303 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL INDUSTRIAL, SCIENTIFIC, AND MEDICAL EQUIPMENT Technical Standards § 18.303 Prohibited frequency bands. Operation of ISM equipment within the...

Low band gap polymers for organic photovoltaics

DEFF Research Database (Denmark)

Bundgaard, Eva; Krebs, Frederik C

2007-01-01

Low band gap polymer materials and their application in organic photovoltaics (OPV) are reviewed. We detail the synthetic approaches to low band gap polymer materials starting from the early methodologies employing quinoid homopolymer structures to the current state of the art that relies...

True photonic band-gap mode-control in VCSEL structures

DEFF Research Database (Denmark)

Romstad, F.; Madsen, M.; Birkedal, Dan

2003-01-01

Photonic band-gap mode confinement in novel nano-structured large area VCSEL structures is confirmed by the amplified spontaneous emission spectrum. Both guide and anti-guide VCSEL structures are experimentally characterised to verify the photonic band-gap effect.......Photonic band-gap mode confinement in novel nano-structured large area VCSEL structures is confirmed by the amplified spontaneous emission spectrum. Both guide and anti-guide VCSEL structures are experimentally characterised to verify the photonic band-gap effect....

Experimental study on the adiabatic shear bands

International Nuclear Information System (INIS)

Affouard, J.

1984-07-01

Four martensitic steels (Z50CDV5 steel, 28CND8 steel, 35NCDV16 steel and 4340 steel) with different hardness between 190 and 600 Hsub(B) (Brinell hardness), have been studied by means of dynamic compressive tests on split Hopkinson pressure bar. Microscopic observations show that the fracture are associated to the development of adiabatic shear bands (except 4340 steel with 190 Hsub(B) hardness). By means of tests for which the deformation is stopped at predetermined levels, the measurement of shear and hardness inside the band and the matrix indicates the chronology of this phenomenon: first the localization of shear, followed by the formation of adiabatic shear band and ultimatly crack initiation and propagation. These results correlated with few simulations by finite elements have permitted to suggest two mecanisms of deformation leading to the formation of adiabatic shear bands in this specific test [fr

Enhancement of phononic band gaps in ternary/binary structure

International Nuclear Information System (INIS)

Aly, Arafa H.; Mehaney, Ahmed

2012-01-01

Based on the transfer matrix method (TMM) and Bloch theory, the interaction of elastic waves (normal incidence) with 1D phononic crystal had been studied. The transfer matrix method was obtained for both longitudinal and transverse waves by applying the continuity conditions between the consecutive unit cells. Dispersion relations are calculated and plotted for both binary and ternary structures. Also we have investigated the corresponding effects on the band gaps values for the two types of phononic crystals. Furthermore, it can be observed that the complete band gaps are located in the common frequency stop-band regions. Numerical simulations are performed to investigate the effect of different thickness ratios inside each unit cell on the band gap values, as well as unit cells thickness on the central band gap frequency. These phononic band gap materials can be used as a filter for elastic waves at different frequencies values.

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

Mesentero-axial gastric volvulus after removal of laparoscopic adjustable gastric band.

Science.gov (United States)

Pirmadjid, N; Pournaras, D J; Huan, S; Sujendran, V

2017-02-01

Despite the decreasing popularity of gastric banding, a large number of patients still have a band in situ. Although immediate postoperative complications are relatively rare, long-term complications of gastric banding are more common but are not reported to occur after band removal. We report a case of gastric volvulus and subsequent ischaemic perforation in a patient shortly after band removal, resulting in emergency laparotomy and total gastrectomy. Severe continuing pain persisting after band deflation and even gastric band removal should be treated as an emergency and urgent investigation should not be delayed.

Effectiveness of various sterilization methods of contaminated post-fitted molar band

Directory of Open Access Journals (Sweden)

Anggia Tridianti

2013-06-01

Full Text Available Background: Molar band as anchoring device may be contaminated during the fitting process. Thus, decontamination process is essential to prevent cross-infection between patients. Purpose: The objective of this research was to determine the amount of bacteria in molar band post-fitted on the patient teeth, after previously undergone pre-sterilization using alcohol and ultrasonic cleaning bath followed by sterilization using dry heat oven and steam autoclave, in order to find the best method in decontamination of post-fitted molar band. Methods: Four molar bands which already fitted on one patient then divided evenly into two groups. The first group was pre-sterilized using alcohol. One of the bands then sterilized using dry heat oven, while the other one was sterilized using steam autoclave. The second group was pre-sterilized using ultrasonic cleaning bath. One band from this group then sterilized using dry heat oven and the other was sterilized using steam autoclave. The next step was to immerse all the bands in a phosphate-buffered saline solution. Using micropipette, the solution was retrieved and dropped upon a petri dish containing Brain Heart Infusion broth. The dish was then stored in an incubator for 24 hours, prior to counting the number of bacteria existed. The same methods were used to the rest of the patients, with total 128 molar bands from 32 patients. Results: There was a profound difference in numbers of bacteria found between those methods of sterilization. However, there was a non significant difference between the two groups which were at the alcohol-steam autoclave group and at the ultrasonic cleaning bath-steam autoclave group. Conclusion: This study showed that steam autoclave is better than for sterilizing molar band, as it left the minimal amount of bacteria in post-fitted molar band.Latar belakang: Molar band merupakan suatu alat penjangkaran yang dapat mengalami kontaminasi selama proses fitting band, sehingga perlu

Hole energy and momentum distributions in valence bands

International Nuclear Information System (INIS)

Laan, G. van der.

1982-01-01

In order to understand the electrical and magnetic properties of solids, the knowledge of the density of states and the dispersion relation of the valence bands is indispensable. This thesis offers some alternative methods to obtain information about the nature of the valence band. Part A deals with the energy distribution of the photoelectrons. A simple model, which explains the core hole satellite structure in compounds with large correlation effects between the valence band holes and the created photo-hole, is outlined. CuCl, CuX 2 (X = F Cl and Br) are studied, by photoemission and Auger electron spectroscopies in determining the valence band properties. Part B deals with the simultaneous measurement of the energy and the wave vector of the emitted electrons. A practical example is given for the determination of the dispersion relation in copper. The measurements of a surface resonance band and the distribution of the secondary electrons are also reported. (Auth.)

Optimal wavelength band clustering for multispectral iris recognition.

Science.gov (United States)

Gong, Yazhuo; Zhang, David; Shi, Pengfei; Yan, Jingqi

2012-07-01

This work explores the possibility of clustering spectral wavelengths based on the maximum dissimilarity of iris textures. The eventual goal is to determine how many bands of spectral wavelengths will be enough for iris multispectral fusion and to find these bands that will provide higher performance of iris multispectral recognition. A multispectral acquisition system was first designed for imaging the iris at narrow spectral bands in the range of 420 to 940 nm. Next, a set of 60 human iris images that correspond to the right and left eyes of 30 different subjects were acquired for an analysis. Finally, we determined that 3 clusters were enough to represent the 10 feature bands of spectral wavelengths using the agglomerative clustering based on two-dimensional principal component analysis. The experimental results suggest (1) the number, center, and composition of clusters of spectral wavelengths and (2) the higher performance of iris multispectral recognition based on a three wavelengths-bands fusion.

Strongly correlated impurity band superconductivity in diamond: X-ray spectroscopic evidence

Directory of Open Access Journals (Sweden)

G. Baskaran

2006-01-01

Full Text Available In a recent X-ray absorption study in boron doped diamond, Nakamura et al. have seen a well isolated narrow boron impurity band in non-superconducting samples and an additional narrow band at the chemical potential in a superconducting sample. We interpret the beautiful spectra as evidence for upper Hubbard band of a Mott insulating impurity band and an additional metallic 'mid-gap band' of a conducting 'self-doped' Mott insulator. This supports the basic framework of a recent theory of the present author of strongly correlated impurity band superconductivity (impurity band resonating valence bond, IBRVB theory in a template of a wide-gap insulator, with no direct involvement of valence band states.

The Marvels of Electromagnetic Band Gap (EBG) Structures

Science.gov (United States)

2003-11-01

terminology of "Electromagnetic conference papers and journal articles dealing with Band- gaps (EBG)". Recently, many researchers the characterizations...Band Gap (EBG) Structures 9 utilized to reduce the mutual coupling between Structures: An FDTD/Prony Technique elements of antenna arrays. based on the...Band- Gap of several patents. He has had pioneering research contributions in diverse areas of electromagnetics,Snteructure", Dymposiget o l 21 IE 48

Asymmetric acoustic transmission in multiple frequency bands

Energy Technology Data Exchange (ETDEWEB)

Sun, Hong-xiang, E-mail: jsdxshx@ujs.edu.cn [Research Center of Fluid Machinery Engineering and Technology, Jiangsu University, Zhenjiang 212013 (China); Laboratory of Modern Acoustics, Institute of Acoustics, Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093 (China); State Key Laboratory of Acoustics, Institute of Acoustics, Chinese Academy of Sciences, Beijing 100190 (China); Yuan, Shou-qi, E-mail: Shouqiy@ujs.edu.cn [Research Center of Fluid Machinery Engineering and Technology, Jiangsu University, Zhenjiang 212013 (China); Zhang, Shu-yi [Laboratory of Modern Acoustics, Institute of Acoustics, Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093 (China)

2015-11-23

We report both experimentally and numerically that the multi-band device of the asymmetric acoustic transmission is realized by placing two periodic gratings with different periods on both sides of two brass plates immersed in water. The asymmetric acoustic transmission can exist in four frequency bands below 1500 kHz, which arises from the interaction between various diffractions from the two gratings and Lamb modes in the brass plates immersed in water. The results indicate that the device has the advantages of multiple band, broader bandwidth, and simpler structure. Our finding should have great potential applications in ultrasonic devices.

Asymmetric acoustic transmission in multiple frequency bands

International Nuclear Information System (INIS)

Sun, Hong-xiang; Yuan, Shou-qi; Zhang, Shu-yi

2015-01-01

We report both experimentally and numerically that the multi-band device of the asymmetric acoustic transmission is realized by placing two periodic gratings with different periods on both sides of two brass plates immersed in water. The asymmetric acoustic transmission can exist in four frequency bands below 1500 kHz, which arises from the interaction between various diffractions from the two gratings and Lamb modes in the brass plates immersed in water. The results indicate that the device has the advantages of multiple band, broader bandwidth, and simpler structure. Our finding should have great potential applications in ultrasonic devices

Thin-film intermediate band chalcopyrite solar cells

International Nuclear Information System (INIS)

Fuertes Marron, D.; Marti, A.; Luque, A.

2009-01-01

Chalcopyrite-based solar cells currently lead the efficiency tables of thin-film photovoltaic technologies. Further improvements are foreseen upon implementation of an intermediate band in the absorber layers. We present a theoretical analysis of the efficiency limit for this type of device as a function of factors such as the gap of the host, the relative position of the intermediate band with respect to the band edge and the level of light concentration used as illumination. We have also considered the impact of non-idealities on the performance of the device, particularly the effect of electronic losses related to non-radiative recombination

Broad-band hard X-ray reflectors

DEFF Research Database (Denmark)

Joensen, K.D.; Gorenstein, P.; Hoghoj, P.

1997-01-01

Interest in optics for hard X-ray broad-band application is growing. In this paper, we compare the hard X-ray (20-100 keV) reflectivity obtained with an energy-dispersive reflectometer, of a standard commercial gold thin-film with that of a 600 bilayer W/Si X-ray supermirror. The reflectivity...... of the multilayer is found to agree extraordinarily well with theory (assuming an interface roughness of 4.5 Angstrom), while the agreement for the gold film is less, The overall performance of the supermirror is superior to that of gold, extending the band of reflection at least a factor of 2.8 beyond...... that of the gold, Various other design options are discussed, and we conclude that continued interest in the X-ray supermirror for broad-band hard X-ray applications is warranted....

Design studies of the Ku-band, wide-band Gyro-TWT amplifier

Science.gov (United States)

Jung, Sang Wook; Lee, Han Seul; Jang, Kwong Ho; Choi, Jin Joo; Hong, Yong Jun; Shin, Jin Woo; So, Jun Ho; Won, Jong Hyo

2014-02-01

This paper reports a Ku-band, wide band Gyrotron-Traveling-wave-tube(Gyro-TWT) that is currently being developed at Kwangwoon University. The Gyro-TWT has a two stage linear tapered interaction circuit to obtain a wide operating bandwidth. The linearly-tapered interaction circuit and nonlinearly-tapered magnetic field gives the Gyro-TWT a wide operating bandwidth. The Gyro-TWT bandwidth is 23%. The 2d-Particle-in-cell(PIC) and MAGIC2d code simulation results are 17.3 dB and 24.34 kW, respectively for the maximum saturated output power. A double anode MIG was simulated with E-Gun code. The results were 0.7 for the transvers to the axial beam velocity ratio (=alpha) and a 2.3% axial velocity spread at 50 kV and 4 A. A magnetic field profile simulation was performed by using the Poisson code to obtain the grazing magnetic field of the entire interaction circuit with Poisson code.

Ultrawide band gap amorphous oxide semiconductor, Ga–Zn–O

Energy Technology Data Exchange (ETDEWEB)

Kim, Junghwan, E-mail: JH.KIM@lucid.msl.titech.ac.jp [Materials and Structures Laboratory, Tokyo Institute of Technology, Mailbox R3-4, 4259 Nagatsuta, Midori-ku, Yokohama (Japan); Miyokawa, Norihiko; Sekiya, Takumi; Ide, Keisuke [Materials and Structures Laboratory, Tokyo Institute of Technology, Mailbox R3-4, 4259 Nagatsuta, Midori-ku, Yokohama (Japan); Toda, Yoshitake [Materials Research Center for Element Strategy, Tokyo Institute of Technology, Mailbox SE-6, 4259 Nagatsuta, Midori-ku, Yokohama (Japan); Hiramatsu, Hidenori; Hosono, Hideo; Kamiya, Toshio [Materials and Structures Laboratory, Tokyo Institute of Technology, Mailbox R3-4, 4259 Nagatsuta, Midori-ku, Yokohama (Japan); Materials Research Center for Element Strategy, Tokyo Institute of Technology, Mailbox SE-6, 4259 Nagatsuta, Midori-ku, Yokohama (Japan)

2016-09-01

We fabricated amorphous oxide semiconductor films, a-(Ga{sub 1–x}Zn{sub x})O{sub y}, at room temperature on glass, which have widely tunable band gaps (E{sub g}) ranging from 3.47–4.12 eV. The highest electron Hall mobility ~ 7 cm{sup 2} V{sup −1} s{sup −1} was obtained for E{sub g} = ~ 3.8 eV. Ultraviolet photoemission spectroscopy revealed that the increase in E{sub g} with increasing the Ga content comes mostly from the deepening of the valence band maximum level while the conduction band minimum level remains almost unchanged. These characteristics are explained by their electronic structures. As these films can be fabricated at room temperature on plastic, this achievement extends the applications of flexible electronics to opto-electronic integrated circuits associated with deep ultraviolet region. - Highlights: • Incorporation of H/H{sub 2}O stabilizes the amorphous phase. • Ultrawide band gap (~ 3.8 eV) amorphous oxide semiconductor was fabricated. • The increase in band gap comes mostly from the deepening of the valence band maximum level. • Donor level is more likely aligned to the valence band maximum level.

Level structure of 60Ni from the 58Ni(α,2p#betta#) reaction

International Nuclear Information System (INIS)

Chan, T.U.; Morand, C.; Azgui, F.

1982-03-01

The 60 Ni nucleus has been studied via the 58 Ni (α, 2p#betta#) reaction at Esub(α)=32 MeV using in-beam #betta# spectroscopy techniques. High-spin states up to 10 MeV excitation have been established. Among the 5 branches depopulating the Yrast Jsup(π)=7 - state, has been found an E3 transition down to the 4 + state. Comparison with direct reaction results leads to assign very probably the [#betta#fsub(5/2),#betta#gsub(9/2)] 7 - configuration to the Jsup(π)=7 - Yrast state at 5349 keV. Other high-spin states might be accounted for by the breaking of the 56 Ni core

Superdeformation in the A = 190 region. The lead nuclei

Energy Technology Data Exchange (ETDEWEB)

Henry, E A; Becker, J A; Brinkman, M J; Kuhnert, A; Stoyer, M A; Wang, T F; Yates, S W [Lawrence Livermore National Lab., CA (United States); Azaiez, F A; Beausang, C W; Burde, J; Deleplanque, M A; Diamond, R M; Draper, J E; Kelly, W H; Korton, W; Macchiavelli, A O; Oliveira, J; Rubel, E; Stephens, F S [Lawrence Berkeley Lab., CA (United States); Cizewski, J A [Rutgers--the State Univ., New Brunswick, NJ (United States)

1992-08-01

Superdeformed (SD) bands have been identified in the four even-even lead nuclei {sup 192}Pb, {sup 194}Pb, {sup 196}Pb, and {sup 198}Pb. The discovery of SD bands in these nuclei extended the region of superdeformation in the A = 190 region to Z = 82, and to neutron numbers up to N = 116. All of the SD bands in these nuclei are observed with transition energies ranging from about 250 keV to about 600 keV, with the lowest energy SD band transition for the entire region of 169 keV in {sup 194}Pb. The spins deduced for the lowest levels in the SD bands are 6, 8, and 12 for {sup 192,194,196,198}Pb, respectively. The dynamic moments of inertia of {sup 192}Pb and {sup 194}Pb are similar to each other, and to those of many other SD bands in this mass region. The dynamic moments of inertia of {sup 1}`9{sup 6}Pb and {sup 198}Pb are somewhat lower than those of {sup 192,194}Pb at a given frequency. The experimental lifetimes in {sup 194}Pb and the deduced transition quadrupole moments (Qt {approx} 20 eb) are equal to those of other nuclei in the region within errors. While SD bands have been observed in the odd-neutron Hg and Tl nuclei, SD bands have not been reported for the odd-neutron Pb nuclei. In this contribution we discuss briefly three topics on superdeformation in the lead nuclei. First, we have recent experimental data on {sup 196}Pb that extends our knowledge of the SD band in that nucleus. Next we review briefly the population of low-lying yrast levels from the decay of the SD bands in {sup 192,194,196}Pb. Finally, we summarize our efforts to identify superdeformation in the odd-A Pb nuclei. All of the experiments described here were performed using the HERA spectrometer at the 88-Inch Cyclotron facility located at Lawrence Berkeley Laboratory. (author) 9 refs., 4 figs.

Border Structure of Intercalary Heterochromatin Bands of Drosophila melanogaster Polytene Chromosomes.

Science.gov (United States)

Khoroshko, V A; Zykova, T Yu; Popova, O O; Zhimulev, I F

2018-03-01

The precise genomic localization of the borders of 62 intercalary heterochromatin bands in Drosophila polytene chromosomes was determined. A new type of bands containing chromatin of different states was identified. This type is a combination of the gray band and the intercalary heterochromatin band, creating a genetic structure that with a light microscope is identified as a continuous band. The border structure of such bands includes the coding regions of genes with ubiquitous activity.

Focus: Nucleation kinetics of shear bands in metallic glass.

Science.gov (United States)

Wang, J Q; Perepezko, J H

2016-12-07

The development of shear bands is recognized as the primary mechanism in controlling the plastic deformability of metallic glasses. However, the kinetics of the nucleation of shear bands has received limited attention. The nucleation of shear bands in metallic glasses (MG) can be investigated using a nanoindentation method to monitor the development of the first pop-in event that is a signature of shear band nucleation. The analysis of a statistically significant number of first pop-in events demonstrates the stochastic behavior that is characteristic of nucleation and reveals a multimodal behavior associated with local spatial heterogeneities. The shear band nucleation rate of the two nucleation modes and the associated activation energy, activation volume, and site density were determined by loading rate experiments. The nucleation activation energy is very close to the value that is characteristic of the β relaxation in metallic glass. The identification of the rate controlling kinetics for shear band nucleation offers guidance for promoting plastic flow in metallic glass.

The behaviour of the moment of inertia curve in a recrossing of the ground state band and the super band in 158Er

International Nuclear Information System (INIS)

Dracoulis, G.D.

1978-11-01

The recrossing of the ground state band with the super band as an explanation for the second anomaly in 158 Er is examined in terms of the moment of inertia. A two band mixing calculation does not reproduce the experimenal moment of inertia curve

Band structure, band offsets, substitutional doping, and Schottky barriers of bulk and monolayer InSe

Science.gov (United States)

Guo, Yuzheng; Robertson, John

2017-09-01

We present a detailed study of the electronic structure of the layered semiconductor InSe. We calculate the band structure of the monolayer and bulk material using density functional theory, hybrid functionals, and G W . The band gap of the monolayer InSe is calculated to be 2.4 eV in screened exchange hybrid functional, close to the experimental photoluminescence gap. The electron affinities and band offsets are calculated for vertical stacked-layer heterostructures, and are found to be suitable for tunnel field effect transistors (TFETs) in combination with WS e2 or similar. The valence-band edge of InSe is calculated to lie 5.2 eV below the vacuum level, similar to that for the closed shell systems HfS e2 or SnS e2 . Hence InSe would be suitable to act as a p -type drain in the TFET. The intrinsic defects are calculated. For Se-rich layers, the Se adatom (interstitial) is found to be the most stable defect, whereas for In-rich layers, the Se vacancy is the most stable for the neutral state. Antisites tend to have energies just above those of vacancies. The Se antisite distorts towards a bond-breaking distortion as in the EL2 center of GaAs. Both substitutional donors and acceptors are calculated to be shallow, and effective dopants. They do not reconstruct to form nondoping configurations as occurs in black phosphorus. Finally, the Schottky barriers of metals on InSe are found to be strongly pinned by metal induced gap states (MIGS) at ˜0.5 eV above the valence-band edge. Any interfacial defects would lead to a stronger pinning at a similar energy. Overall, InSe is an effective semiconductor combining the good features of 2D (lack of dangling bonds, etc.) with the good features of 3D (effective doping), which few others achieve.

Life with a Gastric Band. Long-Term Outcomes of Laparoscopic Adjustable Gastric Banding-a Retrospective Study.

Science.gov (United States)

Kowalewski, Piotr K; Olszewski, Robert; Kwiatkowski, Andrzej; Gałązka-Świderek, Natalia; Cichoń, Krzysztof; Paśnik, Krzysztof

2017-05-01

Laparoscopic adjustable gastric banding (LAGB) is the third most popular bariatric procedure worldwide. Various authors present ambivalent long-term follow up results. We revised records of the patients who underwent LAGB between 2003 and 2006 along with history of additional check-ins. Patients with outdated details were tracked with the national health insurance database and social media (Facebook). An online survey was sent. The patients who did not have their band removed were included in this study. We calculated the percent total weight loss (%TWL) and percent excess weight loss (%EWL), along with changes in body mass index (ΔBMI). Satisfactory weight loss was set at >50% EWL (for BMI = 25 kg/m 2 ). Since eight patients gained weight, we decided to include negative values of %TWL, %EWL, and ΔBMI. One hundred seven patients underwent LAGB from 2003 to 2006. The mean follow-up time was 11.2 (±1.2) years. Eleven percent of patients were lost to follow up (n = 12). There was one perioperative death. Fifty-four of the patients (n = 57) had their band removed. Thirty-seven patients still have the band (39%) and were included in the study. The mean %EWL was 27% (-56-112%) and %TWL was 11% (-19-53%). Twelve patients achieved %EWL > 50% (32%). Thiry-two patients still suffer from obesity, with BMI over 30 kg/m 2 . Eight patients (22%) gained additional weight. Patients with %EWL > 50% suffered less from gastroesophageal reflux disease symptoms than those with EWL < 50% (p < 0.05). Out of 107 cases, only 11.2% of patients with gastric band (n = 12) achieved satisfactory %EWL. Twenty-two percent of patients regained their weight or even exceeded it. Overall results suggest that LAGB is not an effective bariatric procedure in long term observation.

Band width and multiple-angle valence-state mapping of diamond

International Nuclear Information System (INIS)

Jimenez, I.; Terminello, L.J.; Sutherland, D.G.J.

1997-01-01

The band width may be considered the single most important parameter characterizing the electronic structure of a solid. The ratio of band width and Coulomb repulsion determines how correlated or delocalized an electron system is. Some of the most interesting solids straddle the boundary between localized and delocalized, e.g. the high-temperature superconductors. The bulk of the band calculations available today is based on local density functional (DF) theory. Even though the Kohn-Sham eigenvalues from that theory do not represent the outcome of a band-mapping experiment, they are remarkably similar to the bands mapped via photoemission. Strictly speaking, one should use an excited state calculation that takes the solid's many-body screening response to the hole created in photoemission into account. Diamond is a useful prototype semiconductor because of its low atomic number and large band width, which has made it a long-time favorite for testing band theory. Yet, the two experimental values of the band width of diamond have error bars of ±1 eV and differ by 3.2 eV. To obtain an accurate valence band width for diamond, the authors use a band-mapping method that collects momentum distributions instead of the usual energy distributions. This method has undergone extensive experimental and theoretical tests in determining the band width of lithium fluoride. An efficient, imaging photoelectron spectrometer is coupled with a state-of-the-art undulator beam line at the Advanced Light Source to allow collection of a large number of data sets. Since it takes only a few seconds to take a picture of the photoelectrons emitted into a 84 degrees cone, the authors can use photon energies as high as 350 eV where the cross section for photoemission from the valence band is already quite low, but the emitted photoelectrons behave free-electron-like. This make its much easier to locate the origin of the inter-band transitions in momentum space

Band width and multiple-angle valence-state mapping of diamond

Energy Technology Data Exchange (ETDEWEB)

Jimenez, I.; Terminello, L.J.; Sutherland, D.G.J. [Lawrence Berkeley National Lab., CA (United States)] [and others

1997-04-01

The band width may be considered the single most important parameter characterizing the electronic structure of a solid. The ratio of band width and Coulomb repulsion determines how correlated or delocalized an electron system is. Some of the most interesting solids straddle the boundary between localized and delocalized, e.g. the high-temperature superconductors. The bulk of the band calculations available today is based on local density functional (DF) theory. Even though the Kohn-Sham eigenvalues from that theory do not represent the outcome of a band-mapping experiment, they are remarkably similar to the bands mapped via photoemission. Strictly speaking, one should use an excited state calculation that takes the solid`s many-body screening response to the hole created in photoemission into account. Diamond is a useful prototype semiconductor because of its low atomic number and large band width, which has made it a long-time favorite for testing band theory. Yet, the two experimental values of the band width of diamond have error bars of {+-}1 eV and differ by 3.2 eV. To obtain an accurate valence band width for diamond, the authors use a band-mapping method that collects momentum distributions instead of the usual energy distributions. This method has undergone extensive experimental and theoretical tests in determining the band width of lithium fluoride. An efficient, imaging photoelectron spectrometer is coupled with a state-of-the-art undulator beam line at the Advanced Light Source to allow collection of a large number of data sets. Since it takes only a few seconds to take a picture of the photoelectrons emitted into a 84{degrees} cone, the authors can use photon energies as high as 350 eV where the cross section for photoemission from the valence band is already quite low, but the emitted photoelectrons behave free-electron-like. This make its much easier to locate the origin of the inter-band transitions in momentum space.

VIBRONIC PROGRESSIONS IN SEVERAL DIFFUSE INTERSTELLAR BANDS

International Nuclear Information System (INIS)

Duley, W. W.; Kuzmin, Stanislav

2010-01-01

A number of vibronic progressions based on low-energy vibrational modes of a large molecule have been found in the diffuse interstellar band (DIB) spectrum of HD 183143. Four active vibrational modes have been identified with energies at 5.18 cm -1 , 21.41 cm -1 , 31.55 cm -1 , and 34.02 cm -1 . The mode at 34.02 cm -1 was previously recognized by Herbig. Four bands are associated with this molecule, with origins at 6862.61 A, 6843.64 A, 6203.14 A, and 5545.11 A (14589.1 cm -1 , 14608.08 cm -1 , 16116.41 cm -1 , and 18028.9 cm -1 , respectively). The progressions are harmonic and combination bands are observed involving all modes. The appearance of harmonic, rather than anharmonic, terms in these vibronic progressions is consistent with torsional motion of pendant rings, suggesting that the carrier is a 'floppy' molecule. Some constraints on the type and size of the molecule producing these bands are discussed.

X-band RF power sources for accelerator applications

International Nuclear Information System (INIS)

Kirshner, Mark F.; Kowalczyk, Richard D.; Wilsen, Craig B.; True, Richard B.; Simpson, Ian T.; Wray, John T.

2011-01-01

The majority of medical and industrial linear accelerators (LINACs) in use today operate at S-band. To reduce size and weight, these systems are gradually migrating toward X-band. The new LINACs will require suitable RF components to power them. In anticipation of this market, L-3 Communications Electron Devices Division (EDD) has recently developed a suite of RF sources operating at 9.3 GHz to complement our existing S-band product line. (author)

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.

Band mapping of surface states vs. adsorbate coverage

International Nuclear Information System (INIS)

Rotenberg, E.; Kevan, S.D.; Denlinger, J.D.; Chung, Jin-Wook

1997-01-01

The theory of electron bands, which arises from basic quantum mechanical principles, has been the cornerstone of solid state physics for over 60 years. Simply put, an energy band is an electron state in a solid whose energy varies with its momentum (similar to, but with a more complicated dependence than, how a free electron's energy is proportional to its momentum squared). Much attention over the last 15 years has been given to the study of band structure of surfaces and interfaces, especially as the applications of these two-dimensional systems have become increasingly important to industry and science. The ultraESCA endstation at beamline 7.01 at the Advanced Light Source was developed for very high-energy - (∼50 meV) and angular - ( 12 photons/sec) makes the detailed study of the evolution of bands possible. The authors are interested in learning how, when one forms a chemical bond between a metal and an overlaying atom or molecule, the resulting charge transfer to or from the adsorbate affects the surface bands. In some cases of interest, intermediate coverages lead to different band structure than at the extremes of clean and saturated surfaces. Surfaces of tungsten are particularly interesting, as their atomic geometry has been shown to be exquisitely sensitive to both the surface vibrational and electronic properties. In this study, the authors looked at the surface bands of tungsten ((110) surface), as a function both of coverage and mass of overlaying atoms. The adsorbed atoms were hydrogen and the alkali atoms lithium and cesium

Silicon rich nitride ring resonators for rare - earth doped telecommunications-band amplifiers pumped at the O-band.

Science.gov (United States)

Xing, P; Chen, G F R; Zhao, X; Ng, D K T; Tan, M C; Tan, D T H

2017-08-22

Ring resonators on silicon rich nitride for potential use as rare-earth doped amplifiers pumped at 1310 nm with amplification at telecommunications-band are designed and characterized. The ring resonators are fabricated on 300 nm and 400 nm silicon rich nitride films and characterized at both 1310 nm and 1550 nm. We demonstrate ring resonators exhibiting similar quality factors exceeding 10,000 simultaneously at 1310 nm and 1550 nm. A Dysprosium-Erbium material system exhibiting photoluminescence at 1510 nm when pumped at 1310 nm is experimentally demonstrated. When used together with Dy-Er co-doped particles, these resonators with similar quality factors at 1310 nm and 1550 nm may be used for O-band pumped amplifiers for the telecommunications-band.

Wild Band Edges: The Role of Bandgap Grading and Band-Edge Fluctuations in High-Efficiency Chalcogenide Devices: Preprint

Energy Technology Data Exchange (ETDEWEB)

Repins, Ingrid; Mansfield, Lorelle; Kanevce, Ana; Jensen, Soren A.; Kuciauskas, Darius; Glynn, Stephen; Barnes, Teresa; Metzger, Wyatt; Burst, James; Jiang, Chun-Sheng; Dippo, Patricia; Harvey, Steve; Teeter, Glenn; Perkins, Craig; Egaas, Brian; Zakutayev, Andriy; Alsmeier, J.-H.; Lussky, T.; Korte, L.; Wilks, R. G.; Bar, M.; Yan, Y.; Lany, Stephan; Zawadzki, Pawel; Park, Ji-Sang; Wei, Suhuai

2016-06-16

Band-edge effects -- including grading, electrostatic fluctuations, bandgap fluctuations, and band tails -- affect chalcogenide device efficiency. These effects now require more careful consideration as efficiencies increase beyond 20%. Several aspects of the relationships between band-edge phenomena and device performance for NREL absorbers are examined. For Cu(In,Ga)Se2 devices, recent increases in diffusion length imply changes to optimum bandgap profile. The origin, impact, and modification of electrostatic and bandgap fluctuations are also discussed. The application of the same principles to devices based on CdTe, kesterites, and emerging absorbers (Cu2SnS3, CuSbS2), considering differences in materials properties and defect formation energies, is examined.

Design and experimental verification of a dual-band metamaterial filter

Science.gov (United States)

Zhu, Hong-Yang; Yao, Ai-Qin; Zhong, Min

2016-10-01

In this paper, we present the design, simulation, and experimental verification of a dual-band free-standing metamaterial filter operating in a frequency range of 1 THz-30 THz. The proposed structure consists of periodically arranged composite air holes, and exhibits two broad and flat transmission bands. To clarify the effects of the structural parameters on both resonant transmission bands, three sets of experiments are performed. The first resonant transmission band shows a shift towards higher frequency when the side width w 1 of the main air hole is increased. In contrast, the second resonant transmission band displays a shift towards lower frequency when the side width w 2 of the sub-holes is increased, while the first resonant transmission band is unchanged. The measured results indicate that these resonant bands can be modulated individually by simply optimizing the relevant structural parameters (w 1 or w 2) for the required band. In addition, these resonant bands merge into a single resonant band with a bandwidth of 7.7 THz when w 1 and w 2 are optimized simultaneously. The structure proposed in this paper adopts different resonant mechanisms for transmission at different frequencies and thus offers a method to achieve a dual-band and low-loss filter. Project supported by the Doctorate Scientific Research Foundation of Hezhou University, China (Grant No. HZUBS201503), the Promotion of the Basic Ability of Young and Middle-aged Teachers in Universities Project of Guangxi Zhuang Autonomous Region, China (Grant No. KY2016YB453), the Guangxi Colleges and Universities Key Laboratory Symbolic Computation, China, Engineering Data Processing and Mathematical Support Autonomous Discipline Project of Hezhou University, China (Grant No. 2016HZXYSX01).

Research on low-frequency band gap property of a hybrid phononic crystal

Science.gov (United States)

Dong, Yake; Yao, Hong; Du, Jun; Zhao, Jingbo; Chao, Ding; Wang, Benchi

2018-05-01

A hybrid phononic crystal has been investigated. The characteristic frequency of XY mode, transmission loss and displacement vector have been calculated by the finite element method. There are Bragg scattering band gap and local resonance band gap in the band structures. We studied the influence factors of band gap. There are many flat bands in the eigenfrequencies curve. There are many flat bands in the curve. The band gap covers a large range in low frequency. The band gaps cover more than 95% below 3000 Hz.

Electronic band structure of lithium, sodium and potassium fluorides

International Nuclear Information System (INIS)

Jouanin, C.; Albert, J.P.; Gout, C.

1975-01-01

A mixed tight-binding, pseudopotential method is proposed to calculate the energy band structure of large-gap crystals and is tested here on LiF, NaF and KF. Three-centre terms are included in the determination of the valence bands by the tight-binding method and for the conduction bands we use a pseudopotential model proposed by Bassani and Giuliano, modified for the positive ions. By taking into account the polarization corrections, transitions calculated from the energy band structures are compared with experimental data and the agreement is generally good

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

Picosecond thermometer in the amide I band of myoglobin

DEFF Research Database (Denmark)

Austin, R.H.; Xie, A.; Meer, L. van der

2005-01-01

The amide I and II bands in myoglobin show a heterogeneous temperature dependence, with bands at 6.17 and 6.43 mu m which are more intense at low temperatures. The amide I band temperature dependence is on the long wavelength edge of the band, while the short wavelength side has almost...... can be used to determine the time it takes vibrational energy to flow into the hydration shell. We determine that vibrational energy flow to the hydration shell from the amide I takes approximately 20 ps to occur....

CSF oligoclonal banding - slideshow

Science.gov (United States)

... this page: //medlineplus.gov/ency/presentations/100145.htm CSF oligoclonal banding - series—Normal anatomy To use the ... 5 out of 5 Overview The cerebrospinal fluid (CSF) serves to supply nutrients to the central nervous ...

Development of a Control Banding Tool for Nanomaterials

OpenAIRE

Riediker, M.; Ostiguy, C.; Triolet, J.; Troisfontaine, P.; Vernez, D.; Bourdel, G.; Thieriet, N.; Cadène, A.

2012-01-01

Control banding (CB) can be a useful tool for managing the potential risks of nanomaterials. The here proposed CB, which should be part of an overall risk control strategy, groups materials by hazard and emission potential. The resulting decision matrix proposes control bands adapted to the risk potential levels and helps define an action plan. If this plan is not practical and financially feasible, a full risk assessment is launched. The hazard banding combines key concepts of nanomaterial t...

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

Theta band activity in response to emotional expressions and its relationship with gamma band activity as revealed by MEG and advanced beamformer source imaging

Directory of Open Access Journals (Sweden)

Qian eLuo

2014-02-01

Full Text Available Neuronal oscillations in the theta and gamma bands have been shown to be important for cognition. Here we examined the temporal and spatial relationship between the two frequency bands in emotional processing using Magnetoencephalography and an advanced dynamic beamformer source imaging method called Synthetic Aperture Magnetometry. We found that areas including the amygdala, visual and frontal cortex showed significant event-related synchronization (ERS in both bands, suggesting a functional association of neuronal oscillations in the same areas in the two bands. However, while the temporal profile in both bands was similar in the amygdala, the peak in gamma band power was much earlier within both visual and frontal areas. Our results do not support a traditional view that the localizations of lower and higher frequencies are spatially distinct. Instead, they suggest that in emotional processing, neuronal oscillations in the gamma and theta bands may reflect, at least in visual and frontal cortex either different but related functional processes or, perhaps more probably, different computational components of the same functional process.

RRI-GBT MULTI-BAND RECEIVER: MOTIVATION, DESIGN, AND DEVELOPMENT

International Nuclear Information System (INIS)

Maan, Yogesh; Deshpande, Avinash A.; Chandrashekar, Vinutha; Chennamangalam, Jayanth; Rao, K. B. Raghavendra; Somashekar, R.; Ezhilarasi, M. S.; Sujatha, S.; Kasturi, S.; Sandhya, P.; Duraichelvan, R.; Amiri, Shahram; Aswathappa, H. A.; Sarabagopalan, G.; Ananda, H. M.; Anderson, Gary; Bauserman, Jonah; Beaudet, Carla; Bloss, Marty; Barve, Indrajit V.

2013-01-01

We report the design and development of a self-contained multi-band receiver (MBR) system, intended for use with a single large aperture to facilitate sensitive and high time-resolution observations simultaneously in 10 discrete frequency bands sampling a wide spectral span (100-1500 MHz) in a nearly log-periodic fashion. The development of this system was primarily motivated by need for tomographic studies of pulsar polar emission regions. Although the system design is optimized for the primary goal, it is also suited for several other interesting astronomical investigations. The system consists of a dual-polarization multi-band feed (with discrete responses corresponding to the 10 bands pre-selected as relatively radio frequency interference free), a common wide-band radio frequency front-end, and independent back-end receiver chains for the 10 individual sub-bands. The raw voltage time sequences corresponding to 16 MHz bandwidth each for the two linear polarization channels and the 10 bands are recorded at the Nyquist rate simultaneously. We present the preliminary results from the tests and pulsar observations carried out with the Robert C. Byrd Green Bank Telescope using this receiver. The system performance implied by these results and possible improvements are also briefly discussed.

RRI-GBT MULTI-BAND RECEIVER: MOTIVATION, DESIGN, AND DEVELOPMENT

Energy Technology Data Exchange (ETDEWEB)

Maan, Yogesh; Deshpande, Avinash A.; Chandrashekar, Vinutha; Chennamangalam, Jayanth; Rao, K. B. Raghavendra; Somashekar, R.; Ezhilarasi, M. S.; Sujatha, S.; Kasturi, S.; Sandhya, P.; Duraichelvan, R.; Amiri, Shahram; Aswathappa, H. A.; Sarabagopalan, G.; Ananda, H. M. [Raman Research Institute, Bangalore (India); Anderson, Gary; Bauserman, Jonah; Beaudet, Carla; Bloss, Marty [National Radio Astronomy Observatory, P.O. Box 2, Green Bank, WV (United States); Barve, Indrajit V. [Indian Institute of Astrophysics, Bangalore (India); and others

2013-01-15

We report the design and development of a self-contained multi-band receiver (MBR) system, intended for use with a single large aperture to facilitate sensitive and high time-resolution observations simultaneously in 10 discrete frequency bands sampling a wide spectral span (100-1500 MHz) in a nearly log-periodic fashion. The development of this system was primarily motivated by need for tomographic studies of pulsar polar emission regions. Although the system design is optimized for the primary goal, it is also suited for several other interesting astronomical investigations. The system consists of a dual-polarization multi-band feed (with discrete responses corresponding to the 10 bands pre-selected as relatively radio frequency interference free), a common wide-band radio frequency front-end, and independent back-end receiver chains for the 10 individual sub-bands. The raw voltage time sequences corresponding to 16 MHz bandwidth each for the two linear polarization channels and the 10 bands are recorded at the Nyquist rate simultaneously. We present the preliminary results from the tests and pulsar observations carried out with the Robert C. Byrd Green Bank Telescope using this receiver. The system performance implied by these results and possible improvements are also briefly discussed.