Isomeric structures in neutron-rich odd-odd Pm (Z = 61) isotopes

International Nuclear Information System (INIS)

Sood, P.C.; Singh, B.; Jain, A.K.

2008-01-01

Each of the heavier odd-odd isotopes, namely, 152 Pm, 154 Pm and 156 Pm, have multiple low-lying isomers, almost all of them with undefined configuration and also undefined energy placement. Present investigations attempt credible characterization of the isomers using a simplified two-quasiparticle rotor model which has been widely employed for description of odd-odd deformed nuclei

Tilted axis rotation in odd-odd {sup 164}Tm

Energy Technology Data Exchange (ETDEWEB)

Reviol, W.; Riedinger, L.L.; Wang, X.Z.; Zhang, J.Y. [Univ. of Tennessee, Knoxville, TN (United States)] [and others

1996-12-31

Ten band structures are observed in {sup 164}Tm, among them sets of parallel and anti-parallel couplings of the proton and neutron spins. The Tilted Axis Cranking scheme is applied for the first time to an odd-odd nucleus in a prominent region of nuclear deformation.

Role of deformation in odd-even staggering in reaction cross sections for 30,31,32Ne and 36,37,38Mg isotopes

Science.gov (United States)

Urata, Y.; Hagino, K.; Sagawa, H.

2017-12-01

We discuss the role of pairing antihalo effect in the observed odd-even staggering in reaction cross sections for 30,31,32Ne and 36,37,38Mg isotopes by taking into account the ground-state deformation of these nuclei. To this end, we construct the ground-state density for the Ne,3130 and Mg,3736 nuclei based on a deformed Woods-Saxon potential, while for the 32Ne and 38Mg nuclei we also take into account the pairing correlation using the Hartree-Fock-Bogoliubov method. We demonstrate that, when the one-neutron separation energy is small for the odd-mass nuclei, a significant odd-even staggering still appears even with finite deformation, although the degree of staggering is somewhat reduced compared to the spherical case. This implies that the pairing antihalo effect in general plays an important role in generating the odd-even staggering in reaction cross sections for weakly bound nuclei.

Quantum shape phase transitions from spherical to deformed for Bose-Fermi systems: the effect of the odd particle around the critical point

Directory of Open Access Journals (Sweden)

Böyükata M.

2014-03-01

Full Text Available Quantum phase transitions in odd-nuclei are investigated within the framework of the interacting boson-fermion model with a description based on the concept of intrinsic states. We consider the case of a single j=9/2 odd-particle coupled to an even-even boson core that performs a transition from spherical to deformed prolate and to deformed gamma-unstable shapes varying a control parameter in the boson Hamiltonian. The effect of the coupling of the odd particle to this core is discussed along the shape transition and, in particular, at the critical point.

The core-quasiparticle model for odd-odd nuclei and applications to candidates for gamma-ray lasers

International Nuclear Information System (INIS)

Strottman, D.D.

1988-01-01

A reliable estimate of the properties of isomers that may be viable candidates for a gamma-ray laser requires the use of the most accurate save functions possible. The majority of models that have been used to estimate the properties of isomers are applicable to only selected regions of the nuclear mass table. In particular, the Bohr-Mottelson model of odd-A and odd-odd nuclei will fail if the even-even core is not strongly deformed or if the deformations are changing strongly as a function of mass. This paper reports how the problem is overcome in a new core- quasiparticle model for odd-odd nuclei. The model introduces the pairing interaction ab initio; the odd-A states are mixtures of particle and hole states. The core may be soft towards deformation or axial asymmetry and may change rapidly as a function of mass. Thus, the model is ideally suited for application to the region of transitional nuclei such as the Te, La, and Os regions

Magnetic dipole moments of deformed odd-A nuclei

Energy Technology Data Exchange (ETDEWEB)

Garg, V P; Sharma, S D; Mahesh, P S [Punjabi Univ., Patiala (India). Dept. of Physics

1976-12-01

Using an extended version of A S Davydov and G F Filippov's model (1958), B E Chi and J P Davidson have calculated magnetic moments of odd-A nuclei in 2s-ld shell, diagonalizing the state matrices for a set of parameters giving the best fit for nuclear spectra (1966). To study the failure of this model in case of nuclear moments, instead of diagonalizing an attempt has been made to simplify the expression for magnetic dipole moment for single nucleonic states without configuration mixing. The model takes care of the proper sign of spin projections. On replacing the total angular momentum j of odd particle (proton or neutron) by its projection ..cap omega.., the expression reduces to that of Mottelson and Nilsson for spin-up nuclei. The Coriolis coupling calculations also have been performed for those odd-A nuclei with K = 1/2. The results are found in better agreement with experimental report in comparison with those of other models.

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.)

Influence of fragment deformation and orientation on compact configuration of odd-Z superheavy nuclei

International Nuclear Information System (INIS)

Gurjit Kaur; Sandhu, Kirandeep; Sharma, Manoj K.

2016-01-01

The synthesis of heavy and superheavy nuclei is generally carried out by using hot and cold fusion reaction mechanisms. It has been noticed that, the cold fusion reactions occur at relatively low excitation energies (E*_C_N ∼ 10-20 MeV) whereas, the hot fusion reactions occur at excitation energies of E*_C_N ∼ 30- 50 MeV. The fusion mechanism is quite different in both the processes. In the cold fusion process, the interaction of spherical targets (Pb and Bi) with deformed light mass projectiles occurs. On the other hand, the fusion of deformed actinide targets with spherical "4"8Ca projectile characterize the hot interaction processes. Hence the deformations and orientations of targets and projectiles play extremely important role in the superheavy fusion process. The present analysis is carried out to aggrandize the work of which illustrate the role of deformations and orientations on even superheavy nuclei. Here, we extend this analysis for odd superheavy nuclei. It is relevant to note that the temperature and angular momentum effects are not included in the present analysis

Simultaneous evaluation of the shell and pairing corrections to the nuclear deformation energy: the case of odd-systems

International Nuclear Information System (INIS)

Benhamouda, N.; Oudih, M.R.

2002-01-01

A method of simultaneous evaluation of the shell and pairing corrections to the nuclear deformation energy, recently proposed for the even-even nuclei, is generalized to the case of odd systems. * By means of the blocked-level technique, a level density with explicit dependence on pairing correlations is defined. The microscopic corrections to the deformation energy are then determined by a procedure which is analogous to that of Strutinsky. The method is applied to the ground state of Europium isotopes using the single-particle energies of a deformed Woods-Saxon mean-field. The obtained results are in good agreement with the experimental values

A semi-classical approach to signature splitting and signature inversion in odd–odd nuclei

International Nuclear Information System (INIS)

Kumar, Vinod; Kumar, Suresh; Kumar, Sushil; Hasan, Zafrul; Koranga, B.S.; Kumar, Deepak; Negi, D.; Angus, Lee

2011-01-01

The signature inversion observed in rotational bands belonging to high-j configurations of odd–odd deformed nuclei has been analyzed within the framework of an axially symmetric rotor plus two-particle model. The Coriolis and n–p interaction are considered the main cause of energy staggering. However, γ-triaxial deformation and the numbers of valence protons, N p , and neutrons, N n also contribute to the energy staggering between odd- and even-spin states. (author)

Simultaneous evaluation of the shell and pairing corrections to the nuclear deformation energy: the case of odd-systems

Energy Technology Data Exchange (ETDEWEB)

Benhamouda, N [Laboratoire de Physique Theoique, Faculte des Sciences, USTHB BP 32 El-Alia, 16111 Bab-Ezzouar, Algers (Algeria); Oudih, M R [CRNA, 2. Bd Frantz Fanon, BP 399 Alger-Gare, Algers (Algeria)

2002-09-15

A method of simultaneous evaluation of the shell and pairing corrections to the nuclear deformation energy, recently proposed for the even-even nuclei, is generalized to the case of odd systems. {sup *} By means of the blocked-level technique, a level density with explicit dependence on pairing correlations is defined. The microscopic corrections to the deformation energy are then determined by a procedure which is analogous to that of Strutinsky. The method is applied to the ground state of Europium isotopes using the single-particle energies of a deformed Woods-Saxon mean-field. The obtained results are in good agreement with the experimental values.

The odd-proton effects on the potential energy surfaces of odd mass Tl, Au, Ir and Re isotopes

CERN Document Server

De Wieclawik, W; Larsson, S E; Leander, G; Vieu, C; Dionisio, J S

1976-01-01

The total potential energy surfaces of thallium, gold, iridium and rhenium odd mass isotopes are calculated microscopically as functions of the quadrupole deformation, epsilon /sub 2/, when the odd protons occupy definite orbitals. The nuclear shapes and the static equilibrium deformations of these nuclei are deduced from the results of these calculations for the proton orbitals nearest to the Fermi level. The influence of the hexadecapole deformation, epsilon /sub 4/, on these results is investigated too. Finally, a few experimental data available for these odd mass nuclei are correlated to the corresponding theoretical results. (16 refs).

Simple description of odd-A nuclei around the critical point of the spherical to axially deformed shape phase transition

International Nuclear Information System (INIS)

Zhang Yu; Pan Feng; Liu Yuxin; Luo Yanan; Draayer, J. P.

2011-01-01

An analytically solvable model, X(3/2j+1), is proposed to describe odd-A nuclei near the X(3) critical point. The model is constructed based on a collective core described by the X(3) critical point symmetry coupled to a spin-j particle. A detailed analysis of the spectral patterns for cases j=1/2 and j=3/2 is provided to illustrate dynamical features of the model. By comparing theory with experimental data and results of other models, it is found that the X(3/2j+1) model can be taken as a simple yet very effective scheme to describe those odd-A nuclei with an even-even core at the critical point of the spherical to axially deformed shape phase transition.

Band-head spectra of low-energy single-particle excitations in some well-deformed, odd-mass heavy nuclei within a microscopic approach

Energy Technology Data Exchange (ETDEWEB)

Koh, Meng-Hock [Universiti Teknologi Malaysia, Skudai, Johor (Malaysia); Univ. Bordeaux, CENBG, UMR5797, Gradignan (France); CNRS, IN2P3, CENBG, UMR5797, Gradignan (France); Duc, Dao Duy [Ton Duc Thang University, Division of Nuclear Physics, Ho Chi Minh City (Viet Nam); Ton Duc Thang University, Faculty of Applied Sciences, Ho Chi Minh City (Viet Nam); Nhan Hao, T.V. [Duy Tan University, Center of Research and Development, Danang (Viet Nam); Hue University, Center for Theoretical and Computational Physics, College of Education, Hue City (Viet Nam); Long, Ha Thuy [Hanoi University of Sciences, Vietnam National University, Hanoi (Viet Nam); Quentin, P. [Universiti Teknologi Malaysia, Skudai, Johor (Malaysia); Univ. Bordeaux, CENBG, UMR5797, Gradignan (France); CNRS, IN2P3, CENBG, UMR5797, Gradignan (France); Ton Duc Thang University, Division of Nuclear Physics, Ho Chi Minh City (Viet Nam); Bonneau, L. [Univ. Bordeaux, CENBG, UMR5797, Gradignan (France); CNRS, IN2P3, CENBG, UMR5797, Gradignan (France)

2016-01-15

In four well-deformed heavy odd nuclei, the energies of low-lying rotational band heads have been determined microscopically within a self-consistent Hartree-Fock-plus-BCS approach with blocking. A Skyrme nucleon-nucleon effective interaction has been used together with a seniority force to describe pairing correlations. Only such states which are phenomenologically deemed to be related to single-particle excitations have been considered. The polarization effects, including those associated with the genuine time-reversal symmetry breaking have been fully taken into account within our model assumptions. The calculated spectra are in reasonably good qualitative agreement with available data for the considered odd-neutron nuclei. This is not so much the case for the odd-proton nuclei. A potential explanation for such a difference in behavior is proposed. (orig.)

Influence of triaxiality on the signature inversion in odd-odd nuclei

International Nuclear Information System (INIS)

Zheng, R.R.; Luo, X.D.; Timar, J.; Sohler, S.; Nyako, B.M.; Zolnai, L.; Paul, E.S.

2004-01-01

Complete text of publication follows. Signature inversion in the A ∼ 100 region has been reported earlier only in the case of the odd-odd 98 Rh nucleus. Our studies on the 100-103 Rh isotopes and a close inspection of the known πg 9/2 νh 11/ 2 bands of the Rh (Z = 45) and Ag (Z = 47) isotopes revealed that the signature splitting effects, earlier considered as quenchings of signature splitting, are not only quenchings but signature inversions. Indeed, the energetically favored signature at low spins in these πg 9/2 νh 11/2 bands is the α = 1 branch (odd spins) instead of the expected α = 0 branch (even spins). The systematic occurrence of signature inversion in this mass region is discussed in Refs. together with attempts to understand its behavior qualitatively. Among many attempts for interpreting the mechanism of signature inversion in odd-odd nuclei, a model using an axially symmetric rotor plus two quasi-particles has already been successfully applied to describe the observed signature inversions in the A ∼ 80 and A ∼ 160 mass regions. According to this model the signature inversion is caused by the competition between the Coriolis and the proton-neutron residual interactions in low K space. Such calculations have been also successfully applied to the π g9/2 νh 11/2 bands in the odd-odd 98 Rh and 102 Rh nuclei. Recent observations of chiral band structures in the nearby Rh nuclei suggest a possibility of triaxiality in these nuclei, too. In the present work we examined the possible influence of triaxiality on the signature inversion using a triaxial rotor plus two-quasiparticle model and compared the results with the experimental data of 98 Rh and 102 Rh. The calculations provided a better agreement with the experiment than the axially symmetric calculations. Compared to the axially symmetric case, the triaxiality applied in the Hamiltonian enlarges the amplitudes of high-spin signature zigzags at small triaxial deformation and might push the

Gamow-Teller decay of T = 1 nuclei to odd-odd N = Z nuclei

Energy Technology Data Exchange (ETDEWEB)

Lisetskiy, A F [National Superconducting Cyclotron Laboratory, MSU, East Lansing, MI 48824 (United States); Gelberg, A [Institute for Nuclear Physics, University of Cologne, 50937 Cologne (Germany); Institute of Physical and Chemical Reasearch (RIKEN), Wako, 351-0198 (Japan); Brentano, P von [Institute for Nuclear Physics, University of Cologne, 50937 Cologne (Germany)

2005-01-01

Transition strengths of Gamow-Teller decay of T{sub z} = {+-}1 nuclei to N = Z odd-odd nuclei have been calculated in a two-nucleon approximation for spherical and deformed nuclei. The results obtained for the latter are quite close to the values obtained by full-space shell-model calculations and to the experiment.

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.

Pseudo-spin band in the odd-odd nucleus sup 1 sup 7 sup 2 Lu

CERN Document Server

Venkova, T; Gast, W; Podsvirova, E O; Jäger, H M; Mihailescu, L; Bazzacco, D; Menegazzo, R; Lunardi, S; Alvarez, C R; Ur, C; Martínez, T; Angelis, G D; Axiotis, M; Napoli, D; Urban, W; Rzaca-Urban, T; Frauendorf, S

2003-01-01

High-spin states in the odd-odd nucleus sup 1 sup 7 sup 2 Lu have been populated in a sup 1 sup 7 sup 0 Er( sup 7 Li,5n) reaction and the emitted gamma-radiation was detected with the GASP array. Two sequences of a new identical band have been observed with the transition energies in the favoured and unfavoured sequences being identical within approx 3 keV at low spins and approx 1 keV at high spins over the whole observed spin range. An interpretation as a pseudo-spin singlet band of pi 1/2 sup - [541] x nu 1/2 sup - [420] configuration is proposed. It represents the best example of a pseudo-spin singlet band in normal deformed nuclei known until now.

High-Spin Structure in Odd-Odd 160Lu Nucleus

International Nuclear Information System (INIS)

Wang Lie-Lin; Lu Jing-Bin; Yang Dong; Ma Ke-Yan; Yin Li-Chang; Zhou Yin-Hang; Wu Xiao-Guang; Wen Shu-Xian; Li Guang-Sheng; Yang Chun-Xiang

2012-01-01

The high-spin states of 160 Lu are populated by the fusion-evaporation reaction 144 Sm( 19 F,3n) 160 Lu at beam energies of 90 and 106 MeV. A new level scheme of 160 Lu is established. A possible isomeric state based on the πh 11/2 νh 9/2 configuration is observed. The new decoupled band with the configuration of πd 3/2 [411]1/2 + νi 13/2 [660]1/2 + is established, and the configurations of these similar decoupled bands in the neighboring odd-odd 162−166 Lu nuclei are suggested. A positive parity coupled band is assigned as the πd 5/2 [402]5/2 + νi 13/2 [660]1/2 + configuration. (nuclear physics)

Magnetic dipole moments of deformed odd-odd nuclei up to 2p-1f shells

Energy Technology Data Exchange (ETDEWEB)

Garg, V P; Verma, A K; Gandhi, R; Sharma, S D [Punjabi Univ., Patiala (India). Dept. of Physics

1981-02-01

The expression for magnetic moments for the states comprising ground state configurations of odd-odd nuclei has been simplified by excluding mixing of other nucleonic configurations. This is contrary to Sharma's and Davidson's results which had been obtained by diagonalizing state matrices for a set of parameters using Davidov and Filippov's non-axial rotor model. According to the relative directions of spins of unpaired odd nucleons, the nuclei have been classified under four categories-an exercise not attempted till now. The calculations have been done with various quenching factors depending upon the relative spin orientations of odd nucleons. For most of the nuclei, the results show considerable improvement over those of Gallagher and Moszkowski and of Sharma.

Single Particle energy levels in ODD-A Nuclei

International Nuclear Information System (INIS)

Lasijo, R.S.

1997-01-01

Singe particle energies for atomic nuclei with odd-A number of nucleons, i.e. nuclei possessing odd number of protons or odd number of neutrons, were calculated based on Nilsson's theory, and then the diagrams were made. the energy diagram is in the from of plot of energies as function of deformations, entities identifying the deviations from the spherical shape. The energy calculations were done using FORTRAN 77 language of PC (Personal Computer) version with Microsoft Fortran Power Station compiler, which was then combined with WORD version 6.0 and EXCEL version 5.0 of WINDOWS WORKGROUP to make the plot

Effect of deformations on the compactness of odd-Z superheavy nuclei formed in cold and hot fusion reactions

Science.gov (United States)

Kaur, Gurjit; Sandhu, Kirandeep; Sharma, Manoj K.

2018-03-01

Using the extended fragmentation theory, the compactness of hot and cold fusion reactions is analyzed for odd-Z nuclei ranging Z = 105- 117. The calculations for the present work are carried out at T = 0MeV and ℓ = 0 ħ, as the temperature and angular momentum effects remain silent while addressing the orientation degree of freedom (i.e. compact angle configuration). In the hot fusion, 48Ca (spherical) + actinide (prolate) reaction, the non-equatorial compact (nec) shape is obtained for Z = 113 nucleus. On the other hand, Z > 113 nuclei favor equatorial compact (ec) configuration. The distribution of barrier height (VB) illustrate that the ec-shape is obtained when the magnitude of quadrupole deformation of the nucleus is higher than the hexadecupole deformation. In other words, negligible or small -ve β4-deformations support ec configurations. On the other hand, large (+ve) magnitude of the β4-deformation suggests that the configuration appears for compact angle θc < 90 °, leading to nec structure. Similar deformation effects are observed for Bi-induced reactions, in which not belly-to-belly compact (nbbc) configurations are seen at θc = 42 °. In addition to the effect of β2 and β4-deformations, the exclusive role of octupole deformations (β3) is also analyzed. The β3-deformations do not follow the reflection symmetry as that of β2 and β4, leading to the possible occurrence of compact configuration within 0° to 180° angular range.

Non-adiabatic description of proton emission from the odd-odd nucleus 130Eu

Directory of Open Access Journals (Sweden)

Patial Monika

2014-03-01

Full Text Available We discuss the non-adiabatic quasiparticle approach for calculating the rotational spectra and decay width of odd-odd proton emitters. The Coriolis effects are incorporated in both the parent and daughter wave functions. Results for the two probable ground states (1+ and 2+ of the proton emitter 130Eu are discussed. With our calculations, we confirm the proton emitting state to be the Iπ = 1+ state, irrespective of the strength of the Coriolis interaction. This study provides us with an opportunity to look into the details of wave functions of deformed odd-odd nuclei to which the proton emission halflives are quite sensitive.

Random interactions, isospin, and the ground states of odd-A and odd-odd nuclei

International Nuclear Information System (INIS)

Horoi, Mihai; Volya, Alexander; Zelevinsky, Vladimir

2002-01-01

It was recently shown that the ground state quantum numbers of even-even nuclei have a high probability to be reproduced by an ensemble of random but rotationally invariant two-body interactions. In the present work we extend these investigations to odd-A and odd-odd nuclei, considering in particular the isospin effects. Studying the realistic shell model as well as the single-j model, we show that random interactions have a tendency to assign the lowest possible total angular momentum and isospin to the ground state. In the sd shell model this reproduces correctly the isospin but not the spin quantum numbers of actual odd-odd nuclei. An odd-even staggering effect in probability of various ground state quantum numbers is present for even-even and odd-odd nuclei, while it is smeared out for odd-A nuclei. The observed regularities suggest the underlying mechanism of bosonlike pairing of fermionic pairs in T=0 and T=1 states generated by the off-diagonal matrix elements of random interactions. The relation to the models of random spin interactions is briefly discussed

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

Enhanced T-odd, P-odd electromagnetic moments in reflection asymmetric nuclei

International Nuclear Information System (INIS)

Spevak, V.; Auerbach, N.; Flambaum, V.V.

1997-01-01

Collective P- and T-odd moments produced by parity and time invariance violating forces in reflection asymmetric nuclei are considered. The enhanced collective Schiff, electric dipole, and octupole moments appear due to the mixing of rotational levels of opposite parity. These moments can exceed single-particle moments by more than 2 orders of magnitude. The enhancement is due to the collective nature of the intrinsic moments and the small energy separation between members of parity doublets. In turn these nuclear moments induce enhanced T- and P-odd effects in atoms and molecules. A simple estimate is given and a detailed theoretical treatment of the collective T-, P-odd electric moments in reflection asymmetric, odd-mass nuclei is presented. In the present work we improve on the simple liquid drop model by evaluating the Strutinsky shell correction and include corrections due to pairing. Calculations are performed for octupole deformed long-lived odd-mass isotopes of Rn, Fr, Ra, Ac, and Pa and the corresponding atoms. Experiments with such atoms may improve substantially the limits on time reversal violation. copyright 1997 The American Physical Society

Effective neutron-proton interaction in rare earth odd-odd nuclei

International Nuclear Information System (INIS)

Boisson, Jean-Paul.

1975-01-01

The effective neutron-proton interaction V(np) in the rare earth odd-odd deformed nuclei is studied. The parameters of the effective interaction are determined from least square fits of calculated matrix elements compared to the ones extracted from experiment. These fits show the existence of a long range repulsive component as well the importance of the even term of the tensor part of V(np). Some informations are obtained concerning the influence of the choice of the sample of experimental data, of the average field and finally, of the radial shape of the effective interaction. Some predictions are made concerning as yet unconfirmed V(np) matrix elements [fr

Study on rotational bands in odd-odd nuclei 102,l04Nb by using PSM

International Nuclear Information System (INIS)

Dong Yongsheng; Hu Wentao; Feng Youliang; Wang Jinbao; Yu Shaoying; Shen Caiwan

2012-01-01

The Projected Shell Model (PSM) is used to study the low energy scheme of the neutron-rich normal-deformed isotopes of odd-odd nuclei 102,104 Nb. The quasiparticle configuration is assigned. The theoretical calculations of the energy band of 102,104 Nb could well reproduce the experimental data. It is shown that PSM is a valid method for studying the low energy scheme of heavy nuclei. (authors)

Low-spin identical bands in odd-A nuclei

International Nuclear Information System (INIS)

Baktash, C.; Garrett, J.D.; Winchell, D.F.; Smith, A.

1992-01-01

A comprehensive study of odd-A rotational bands in normally-deformed rare-earth nuclei indicates that a large number of seniority-one configurations (30% for odd-Z nuclei) at low spin have moments of inertia nearly identical to that of the seniority-zero configuration of the neighboring even-even nucleus with one less nucleon. It is difficult to reconcile these results with conventional models, based on the traditional picture of nuclear pair correlation in vogue for more than three decades, which predict variations of about 15% in the moments of inertia of configurations differing by one unit in seniority

Coulomb excitation of neutron-rich odd-$A$ Cd isotopes

CERN Multimedia

Reiter, P; Kruecken, R; Gernhaeuser, R A; Kroell, T; Leske, J; Marginean, N M

We propose to study excited states in the odd-${A}$ isotopes $^{123,125,127}$Cd by ${\\gamma}$-ray spectroscopy following "safe" Coulomb excitation. The experiment aims to determine the B(E2) values connecting excited states with the ground state as well as the long-lived (11/2$^{-}$) isomer. The proposed study profits from the unique capability of ISOLDE to produce beams containing Cd in the ground state or in the isomeric state. Our recent results on the neutron-rich even-A Cd nuclei appear to show that these nuclei may possess some collectivity beyond that calculated by modern shell-model predictions. Beyond-mean-field calculations also predict these nuclei to be weakly deformed. These facets are surprising considering their proximity to the doubly magic $^{132}$Sn. Coulomb-excitation studies of odd-${A}$ Cd isotopes may give a unique insight into the deformation-driving roles played by different orbits in this region. Such studies of the onset of collectivity become especially important in light of recent...

On supergroups with odd Clifford parameters and non-anticommutative supersymmetry

International Nuclear Information System (INIS)

Kuznetsova, Z.

2007-01-01

We investigate super groups with Grassmann parameters replaced by odd Clifford parameters. The connection with non-anti commutative supersymmetry is discussed. A Berezin-like calculus for odd Clifford variables is introduced. Fermionic covariant derivatives for super groups with odd Clifford variables are derived. Applications to supersymmetric quantum mechanics are made. Deformations of the original supersymmetric theories are encountered when the fermionic covariant derivatives do not obey the graded Leibniz property. The simplest non-trivial example is given by the N = 2 SQM with a real (1, 2, 1) multiplet and a cubic potential. The action is real. Depending on the overall sign ('Euclidean' or 'Lorentzian') of the deformation, a Bender-Boettcher pseudo-hermitian Hamiltonian is encountered when solving the equation of motion of the auxiliary field. A possible connection of our framework with the Drinfeld twist deformation of supersymmetry is pointed out. (author)

Low-spin identical bands in odd-A nuclei

Energy Technology Data Exchange (ETDEWEB)

Baktash, C; Garrett, J D; Winchell, D F; Smith, A [Oak Ridge National Lab., TN (United States)

1992-08-01

A comprehensive study of odd-A rotational bands in normally-deformed rare-earth nuclei indicates that a large number of seniority-one configurations (30% for odd-Z nuclei) at low spin have moments of inertia nearly identical to that of the seniority-zero configuration of the neighboring even-even nucleus with one less nucleon. It is difficult to reconcile these results with conventional models, based on the traditional picture of nuclear pair correlation in vogue for more than three decades, which predict variations of about 15% in the moments of inertia of configurations differing by one unit in seniority. (author). 18 refs., 1 tab., 1 fig.

Low-spin identical bands in odd-A nuclei

International Nuclear Information System (INIS)

Baktash, C.; Garrett, J.D.; Winchell, D.F.; Smith, A.

1992-01-01

A comprehensive study of odd-A rotational bands in normally-deformed rare-earth nuclei indicates that a large number of seniority-one configurations (30% for odd-Z nuclei) at low spin have moments of inertia nearly identical to that of the seniority-zero configuration of the neighboring even-even nucleus with one less nucleon. It is difficult to reconcile these results with conventional models, based on the traditional picture of nuclear pair correlation in vogue for more than three decades, which predict variations of about 15% in the moments of inertia of configurations differing by one unit in seniority. (author). 18 refs., 1 tab., 1 fig

Study of band structure of some odd proton Eu isotopes

International Nuclear Information System (INIS)

Pandit, Rakesh K.; Rani Devi; Khosa, S.K.

2016-01-01

Much work has been done on the odd-Z, odd-A nuclei in the rare earth region because of occurrence of fascinating variety of structures of nuclei in this mass region. The Eu nuclei are in the transitional deformation region and it provides an opportunity to investigate theoretically the deformation changes with mass number and excitation energy besides to study the structure of their excited states. The 153 Eu nucleus has been well studied over the last two decades. The aim of the present work is to study in detail the band structure of some odd-Z nuclei

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

International Nuclear Information System (INIS)

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

1991-01-01

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

Even and odd combinations of nonlinear coherent states

International Nuclear Information System (INIS)

De los Santos-Sanchez, O; Recamier, J

2011-01-01

In this work we present some statistical properties of even and odd combinations of nonlinear coherent states associated with two nonlinear potentials; one supporting a finite number of bound states and the other supporting an infinite number of bound states, within the framework of an f-deformed algebra. We calculate their normalized variance and the temporal evolution of their dispersion relations using nonlinear coherent states defined as (a) eigensates of the deformed annihilation operator and (b) those states created by the application of a deformed displacement operator upon the ground state of the oscillator.

Low-spin identical bands in neighboring odd-A and even-even nuclei

International Nuclear Information System (INIS)

Baktash, C.; Winchell, D.F.; Garrett, J.D.; Smith, A.

1992-01-01

A comprehensive study of odd-A rotational bands in normally deformed rare-earth nuclei indicates that a large number of seniority-one configurations (21% for odd-Z nuclei) at low spin have moments of inertia nearly identical to that of the seniority-zero configuration of the neighboring even-even nucleus with one less nucleon. It is difficult to reconcile these results with conventional models of nuclear pair correlation, which predict variations of about 15% in the moments of inertia of configurations differing by one unit in seniority

Efficient estimation for high similarities using odd sketches

DEFF Research Database (Denmark)

Mitzenmacher, Michael; Pagh, Rasmus; Pham, Ninh Dang

2014-01-01

. This means that Odd Sketches provide a highly space-efficient estimator for sets of high similarity, which is relevant in applications such as web duplicate detection, collaborative filtering, and association rule learning. The method extends to weighted Jaccard similarity, relevant e.g. for TF-IDF vector...... and web duplicate detection tasks....

Low-spin identical bands in neighboring odd-A and even-even nuclei

International Nuclear Information System (INIS)

Baktash, C.; Winchell, D.F.; Garrett, J.D.; Smith, A.

1993-01-01

A comprehensive study of odd-A rotational bands in normally deformed rare-earth nuclei indicates that a large number of seniority-one configurations (21 % for odd-Z nuclei) at low spin have moments of inertia nearly identical to that of the seniority-zero configuration of the neighboring even-even nucleus with one less nucleon. It is difficult to reconcile these results with conventional models of nuclear pair correlation, which predict variations of about 15% in the moments of inertia of configurations differing by one unit in seniority. (orig.)

Decay properties of certain odd-Z SHE

International Nuclear Information System (INIS)

Carmel Vigila Bai, G.M.; Santhosh Kumar, S.

2004-01-01

In this work the well known Cubic plus Yukawa plus Exponential model (CYEM) in two sphere approximation and incorporating deformation effects to parents and daughter was used to study the alpha decay properties of certain odd-Z super heavy elements

Magnetic dipole moments of deformed odd-odd nuclei in 2s-1d and 2p-1f shells

Energy Technology Data Exchange (ETDEWEB)

Verma, A K; Garg, V P; Sharma, S D [Punjabi Univ., Patiala (India). Dept. of Physics

1979-01-01

A simple expression is derived for the computation of the magnetic moments of odd-odd nuclei. The computation of magnetic dipole moments is done with and without quenching factors for the last proton and neutron. The results are found to improve for /sup 22/Na, /sup 24/Na, sup(82m)Rb, /sup 14/N, /sup 68/Gd, /sup 54/Mn and /sup 86/Rb with extreme coupling of angular moments.

Gamma bands in doubly odd rhenium and iridium nuclei

Directory of Open Access Journals (Sweden)

Balodis M.

2015-01-01

Full Text Available Structure of the |K ± 2| bands in doubly-odd nuclei belonging to the transitional deformation region at A∼190 is discussed. Relation of these quasi gamma-bands with the non-axial deformation of the parent two-quasiparticle configurations is studied. Using available experimental information, new tentative |K ± 2| bands are proposed in 188Re, and 192,194Ir nuclei. Coexistence of two-quasiparticle states with different deformation modes is considered in the case of 188Re and 194Ir.

''Identical'' bands in normally-deformed nuclei

International Nuclear Information System (INIS)

Garrett, J.D.; Baktash, C.; Yu, C.H.

1990-01-01

Gamma-ray transitions energies in neighboring odd- and even-mass nuclei for normally-deformed nuclear configurations are analyzed in a manner similar to recent analyses for superdeformed states. The moment of inertia is shown to depend on pair correlations and the aligned angular momentum of the odd nucleon. The implications of this analysis for ''identical'' super-deformed bands are discussed. 26 refs., 9 figs

Lifetimes and magnetic moments in odd-odd 70 As

International Nuclear Information System (INIS)

Pantelica, D.; Negoita, F.; Stanoiu, M.

1998-01-01

The extensive experimental and theoretical work on the structure of N∼Z, A = 60-80 nuclei revealed many interesting features: large prolate deformations (β = 0.4), strong shape variations as a function of particle number, excitation energy, spin and shape coexistence effects. They are related with drastic changes of properties observed in nuclei with Z≥33 when going from spherical nuclei with N = 50 to neutron deficient nuclei with N = 38 or 40. Both the rapid changes in structure and the shape coexistence appear to reflect the competition between the shell gaps which occur at large oblate and prolate deformations near nucleon numbers 36 and 38 for both protons and neutrons. For N∼Z nuclei the same shell gaps appear simultaneously for both protons and neutrons and reinforce each other. The microscopic structure of the nuclei in the mass region A = 60-80 is essentially determined by the 1g 9/2 , 2p 1/2 , 1f 5/2 and 2p 3/2 orbitals. Because no unique interpretation of the unusual features discovered in these nuclei exists, the systematic experimental study of structure of these nuclei is still an interesting subject. As part of a systematic experimental study undertaken to investigate the structure of neutron deficient, odd-odd As nuclei, 68,70,72 As, the level scheme of 70 As was investigated using heavy ion induced reactions and in-beam γ-ray spectroscopy techniques. At energies between 500 and 900 keV a multiplet of negative parity levels has been observed. At higher energies a high-spin positive parity sequence of levels starting with a E x = 1676 keV, J π 8 + level is strongly populated. Additional information is required in order to establish the structure of low and high-spin levels of both parities. The magnetic moments of the 8 + and 9 + levels have been measured using the time-integral perturbed angular distribution technique and the lifetimes of four levels have been determined using the recoil-distance method. From the measured lifetime for the 9

Alpha-cluster preformation factor within cluster-formation model for odd-A and odd-odd heavy nuclei

Science.gov (United States)

Saleh Ahmed, Saad M.

2017-06-01

The alpha-cluster probability that represents the preformation of alpha particle in alpha-decay nuclei was determined for high-intensity alpha-decay mode odd-A and odd-odd heavy nuclei, 82 CSR) and the hypothesised cluster-formation model (CFM) as in our previous work. Our previous successful determination of phenomenological values of alpha-cluster preformation factors for even-even nuclei motivated us to expand the work to cover other types of nuclei. The formation energy of interior alpha cluster needed to be derived for the different nuclear systems with considering the unpaired-nucleon effect. The results showed the phenomenological value of alpha preformation probability and reflected the unpaired nucleon effect and the magic and sub-magic effects in nuclei. These results and their analyses presented are very useful for future work concerning the calculation of the alpha decay constants and the progress of its theory.

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

γ-spectroscopy and radioactive beams: search for highly deformed exotic nuclei

International Nuclear Information System (INIS)

Rosse, B.

2006-07-01

This work is devoted to the search for highly deformed nuclei under extreme conditions of isospin, located near the proton drip-line, around A ∼ 130. The experiment was performed at GANIL (Caen) with the SPIRAL radioactive beam facility. The nuclei of interest were produced by fusion-evaporation reactions induced by the neutron deficient Kr 76 radioactive beam (T1/2 = 14.8 h). γ-rays were detected by the EXOGAM array, composed of 11 segmented germanium clover detectors, for which a new segment calibration method has been developed. To extract fusion-evaporation events of a overwhelming background due to the radioactivity of the beam, the EXOGAM array was coupled with the light charged particle detector DIAMANT and the high acceptance VAMOS spectrometer. The latter was used for the first time to detect fusion-evaporation residues. The detailed data analysis allowed us to demonstrate that the EXOGAM + DIAMANT + VAMOS coupling is operational and essential to investigate the structure of these nuclei. Furthermore, the first γ transition was observed in the very exotic odd-odd Pm 130 nucleus. The results have been interpreted with static and dynamic self-consistent microscopic calculations in collaboration with the Theoretical Physicists of the IPN Lyon. (author)

γ-spectroscopy and radioactive beams: search for highly deformed exotic nuclei

International Nuclear Information System (INIS)

Rosse, Bertrand

2006-01-01

This work is devoted to the search for highly deformed nuclei under extreme conditions of isospin, located near the proton drip-line, around A∼130. The experiment was performed at GANIL (Caen) with the SPIRAL radioactive beam facility. The nuclei of interest were produced by fusion-evaporation reactions induced by the neutron deficient 76 Kr radioactive beam (T 1/2 = 14.8 h). γ-rays were detected by the EXOGAM array, composed of 11 segmented germanium clover detectors, for which a new segment calibration method has been developed. To extract fusion-evaporation events of a overwhelming background due to the radioactivity of the beam, the EXOGAM array was coupled with the light charged particle detector DIAMANT and the high acceptance VAMOS spectrometer. The latter was used for the first time to detect fusion-evaporation residues. The detailed data analysis allowed us to demonstrate that the EXOGAM + DIAMANT + VAMOS coupling is operational and essential to investigate the structure of these nuclei. Furthermore, the first γ transition was observed in the very exotic odd-odd 130 Pm nucleus. The results have been interpreted with static and dynamic self-consistent microscopic calculations in collaboration with the Theoretical Physicists of the IPN Lyon. (author)

Triaxiality in the odd-A nuclei 109−117I studied through a microscopic rotationparticle coupling

Directory of Open Access Journals (Sweden)

Modi Swati

2018-01-01

Full Text Available A systematic study of ground state spectrum with the triaxial deformation γ for odd-A Iodine isotopes 109−117I is carried out with the nonadiabatic quasiparticle approach. The rotation-particle coupling is accomplished microscopically such that the matrix elements of a particle-plus-rotor system are written in terms of the rotor energies. The 5/2+ state is confirmed as ground state for odd-A 111−117I and also coming out as lowest in energy for 109I.

Deformation of high-temperature superconductors

International Nuclear Information System (INIS)

Goretta, K.C.; Routbort, J.L.; Miller, D.J.; Chen, N.; Dominguez-Rodriguez, A.; Jimenez-Melendo, M.; De Arellano-Lopez, A.R.

1994-08-01

Of the many families of high-temperature superconductors, only the properties of those discovered prior to 1989 - Y-Ba-Cu-O, Tl-Ba(Sr)-Ca-Cu-O, and Bi(Pb)-Sr-Ca-Cu-O - have been studied extensively. Deformation tests have been performed on YBa 2 Cu 3 O x (Y-123), YBa 2 Cu 4 O x (Y-124), TlBa 2 Ca 2 Cu 3 O x (Bi-2223). The tests have revealed that plasticity is generally limited in these compounds and that the rate-controlling diffusional kinetics for creep are very slow. Nevertheless, hot forming has proved to be quite successful for fabrication of bulk high-temperature superconductors, so long as deformation rates are low or large hydrostatic stresses are applied. Steady-state creep data have proved to be useful in designing optimal heat treatments for superconductors and in support of more-fundamental diffusion experiments. The high-temperature superconductors are highly complex oxides, and it is a challenge to understand their deformation responses. In this paper, results of interest and operant creep mechanisms will be reviewed

Woods-Saxon potential parametrization at large deformations for plutonium odd isotopes

International Nuclear Information System (INIS)

Garcia, F.; Garrote, E.; Yoneama, M.L.; Arruda-Neto, J.D.T.; Mesa, J.; Bringas, F.; Likhachev, V.P.; Rodriguez, O.; Guzman, F.

1999-01-01

The structure of single-particle levels in the second minima of 237,239,241 Pu was analyzed with the help of an axially-deformed Woods-Saxon potential. The nuclear shape was parametrized in terms of the cassinian ovaloids. A parametrization of the spin-orbit part of the potential was obtained in the region corresponding to large deformations (second minimum), depending only on the nuclear surface area. With this parametrization, we were able to reproduce successfully the spin, parity and energies of the rotational band built on the 8 μ s isomeric state in 239 Pu and, also, a spin assignment for both isomeric states in 237 Pu and 241 Pu was carried out. (orig.)

A systematic study of odd-odd Gallium nuclei

International Nuclear Information System (INIS)

Allegro, P.R.P.; Medina, N.H.; Oliveira, J.R.B.; Ribas, R.V.; Cybulska, E.W.; Seale, W.A.; Zagatto, V.A.B.; Zahn, G.S.; Genezini, F.A.; Silveira, M.A.G.; Tabor, S.; Bender, P.; Tripathi, V.; Baby, L.

2012-01-01

Full text: Recently, many studies have been published attempting to explain the role of the 0g 9/2 orbital in the high spin excited states of nuclei in the region of the mass A=50-80, especially very neutron rich nuclei like, for example 59-66 Fe [1], 65,67 Cu [2], 70,80 Ge [3,4] nuclei and those with odd mass number like As, Ge and Ga [5]. Stefanescu et al. [6] demonstrated the presence of bands in the neutron-rich isotopes Ga formed from excitation of a proton to the 0g 9/2 orbital and Cheal et al. [7] revealed, from the study of the spins and moments of the ground state, changes in nuclear structure of the odd Ga isotopes between N = 40 and N 50, indicating a change in the energy gap between the 0g 9/2 orbital and the pf shell. In this work, we have performed a systematic study of odd-odd 64,66,68,70 Ga nuclei to examine the behavior of the 0g 9/2 orbital with an increasing number of neutrons. We have compared the predictions of the Large Scale Shell Model, obtained using the Antoine code [8] with the FPG [9] and JUN45 [10] effective interactions, with the experimental results obtained with in-beam gamma-ray spectroscopy experiments performed at University of Sao Paulo using SACI-PERERE spectrometer and at Florida State University using the Clover Array System. We have also performed calculations to study 67 Ge, an odd nucleus in the same mass region, in order to verify the behavior of the effective interactions in a nucleus without the proton-neutron interaction. [1] S. Lunardi. et al., Phys. Rev. C 76, 034303 (2007). [2] C. J. Chiara et al., Phys. Rev. C 85, 024309 (2012). [3] M. Sugawara et al., Phys. Rev. C 81, 024309 (2010). [4] H. Iwasaki.et al., Phys. Rev. C 78, 021304(R) (2008). [5] N. Yoshinaga et al. Phys. Rev. C 78, 044320 (2008). [6] I. Stefanescu et al., Phys. Rev. C 79, 064302 (2009). [7] B. Cheal et al. Phys. Rev. Lett. 104, 252502 (2010). [8] E. Caurier and F. Nowacki, Acta Phys. Polonica B 30, 705 (1999). [9] O. Sorlin et al., Phys. Rev. Lett

Woods-Saxon potential parametrization at large deformations for odd-plutonium nuclei

International Nuclear Information System (INIS)

Garcia, F.; Yoneama, M.L.; Arruda Neto, J.D.T.; Mesa, J.; Bringas, F.; Dias, J.F.; Likhachev, V.P.

1997-01-01

The structure of the the single-particle levels in the secondary minima of 237,239,241 Pu fissioning nuclei is analysed with the help of an axially-deformed Woods-Saxon potential. The nuclear shape was parametrized in terms of the Cassinian ovaloids. The parametrization of the spin-orbit part of the potential in the region corresponding to large deformations (second minimum), which depends only on the nuclear surface area, B s , was obtained. With this relation we were able to reproduce successfully the spin (parity) and the energies of the rotational band built on the 8μs isomeric rate in 239 Pu and also to make a spin assignment for both isomer states in 237 Pu and 241 Pu. (author)

{gamma}-spectroscopy and radioactive beams: search for highly deformed exotic nuclei; Detection {gamma} et faisceaux radioactifs: recherche de noyaux exotiques tres deformes

Energy Technology Data Exchange (ETDEWEB)

Rosse, B

2006-07-15

This work is devoted to the search for highly deformed nuclei under extreme conditions of isospin, located near the proton drip-line, around A {approx} 130. The experiment was performed at GANIL (Caen) with the SPIRAL radioactive beam facility. The nuclei of interest were produced by fusion-evaporation reactions induced by the neutron deficient Kr{sup 76} radioactive beam (T1/2 = 14.8 h). {gamma}-rays were detected by the EXOGAM array, composed of 11 segmented germanium clover detectors, for which a new segment calibration method has been developed. To extract fusion-evaporation events of a overwhelming background due to the radioactivity of the beam, the EXOGAM array was coupled with the light charged particle detector DIAMANT and the high acceptance VAMOS spectrometer. The latter was used for the first time to detect fusion-evaporation residues. The detailed data analysis allowed us to demonstrate that the EXOGAM + DIAMANT + VAMOS coupling is operational and essential to investigate the structure of these nuclei. Furthermore, the first {gamma} transition was observed in the very exotic odd-odd Pm{sup 130} nucleus. The results have been interpreted with static and dynamic self-consistent microscopic calculations in collaboration with the Theoretical Physicists of the IPN Lyon. (author)

Coulomb and even-odd effects in cold and super-asymmetric fragmentation for thermal neutron induced fission of 235U

International Nuclear Information System (INIS)

Modesto, Montoya

2014-01-01

The Coulomb effects hypothesis is used to interpret even-odd effects of maximum total kinetic energy as a function of mass and charge of fragments from thermal neutron induced fission of 235 U. Assuming spherical fragments at scission, the Coulomb interaction energy between fragments (C sph ) is higher than the Q-value, the available energy. Therefore at scission the fragments must be deformed, so that the Coulomb interaction energy does not exceed the Q-value. The fact that the even-odd effects in the maximum total kinetic energy as a function of the charge and mass, respectively, are lower than the even-odd effects of Q is consistent with the assumption that odd mass fragments are softer than the even-even fragments. Even-odd effects of charge distribution in super asymmetric fragmentation also are interpreted with the Coulomb effect hypothesis. Because the difference between C sph and Q increases with asymmetry, fragmentations require higher total deformation energy to occur. Higher deformation energy of the fragments implies lower free energy to break pairs of nucleons. This explains why in the asymmetric fragmentation region, the even-odd effects of the distribution of proton number and neutron number increases with asymmetry. (author).

Effects of high-order deformation on high-K isomers in superheavy nuclei

International Nuclear Information System (INIS)

Liu, H. L.; Bertulani, C. A.; Xu, F. R.; Walker, P. M.

2011-01-01

Using, for the first time, configuration-constrained potential-energy-surface calculations with the inclusion of β 6 deformation, we find remarkable effects of the high-order deformation on the high-K isomers in 254 No, the focus of recent spectroscopy experiments on superheavy nuclei. For shapes with multipolarity six, the isomers are more tightly bound and, microscopically, have enhanced deformed shell gaps at N=152 and Z=100. The inclusion of β 6 deformation significantly improves the description of the very heavy high-K isomers.

Where is the Scissors Mode Strength in Odd-Mass Nuclei?

International Nuclear Information System (INIS)

Enders, J.; Huxel, N.; von Neumann-Cosel, P.; Richter, A.

1997-01-01

It is demonstrated by a fluctuation analysis based on the assumption of a Wigner distribution for the nuclear level spacings and of a Porter-Thomas distribution for the transition strengths that significant parts of the dipole strength excited in photon scattering experiments in heavy, deformed odd-mass nuclei are hidden in the background of the experimental spectra. With this additional strength, the heretofore claimed severe reduction of the B(M1) scissors mode strength in odd-mass nuclei compared to the one in neighboring even-even nuclei disappears. copyright 1997 The American Physical Society

High-harmonic spectroscopy of oriented OCS molecules: emission of even and odd harmonics.

Science.gov (United States)

Kraus, P M; Rupenyan, A; Wörner, H J

2012-12-07

We study the emission of even and odd high-harmonic orders from oriented OCS molecules. We use an intense, nonresonant femtosecond laser pulse superimposed with its phase-controlled second harmonic field to impulsively align and orient a dense sample of molecules from which we subsequently generate high-order harmonics. The even harmonics appear around the full revivals of the rotational dynamics. We demonstrate perfect coherent control over their intensity through the subcycle delay of the two-color fields. The odd harmonics are insensitive to the degree of orientation, but modulate with the degree of axis alignment, in agreement with calculated photorecombination dipole moments. We further compare the shape of the even and odd harmonic spectra with our calculations and determine the degree of orientation.

Dynamic tensile behaviour and deformational mechanism of C5191 phosphor bronze under high strain rates deformation

Energy Technology Data Exchange (ETDEWEB)

Hu, Dao-chun [College of Mechanical and Electrical Engineering, Nanjing University of Aeronautics and Astronautics, Nanjing 210016 (China); College of Mechanical and Electrical Engineering, Taizhou Vocational & Technical College, Taizhou 318000 (China); Chen, Ming-he, E-mail: meemhchen@nuaa.edu.cn [College of Mechanical and Electrical Engineering, Nanjing University of Aeronautics and Astronautics, Nanjing 210016 (China); Wang, Lei; Cheng, Hu [College of Mechanical Engineering, Taizhou University, Taizhou 318000 (China)

2016-01-01

High speed stamping process is used to high strength and high electrical conductivity phosphor bronze with extremely high strain rates more than 10{sup 3} s{sup −1}. This study on the dynamic tensile behaviour and deformational mechanism is to optimise the high speed stamping processes and improve geometrical precision in finished products. Thus, the tensile properties and deformation behaviour of C5191 phosphor bronze under quasi-static tensile condition at a strain rate of 0.001 s{sup −1} by electronic universal testing machine, and dynamic tensile condition at strain rate of 500, 1000 and 1500 s{sup −1} by split Hopkinson tensile bar (SHTB) apparatus were studied. The effects of strain rate and the deformation mechanism were investigated by means of SEM and TEM. The results showed that the yield strength and tensile strength of C5191 phosphor bronze under high strain rates deformation increased by 32.77% and 11.07% respectively compared with quasi-static condition, the strain hardening index increases from 0.075 to 0.251, and the strength of the material strain rates sensitivity index change from 0.005 to 0.022, which presented a clear sensitive to strain rates. Therefore, it is claimed that the dominant deformation mechanism was changed by the dislocation motion under different strain rates, and the ability of plastic deformation of C5191 phosphor bronze increased due to the number of movable dislocations increased significantly, started multi-line slip, and the soft effect of adiabatic temperature rise at the strain rate ranging from 500 to 1500 s{sup −1}.

High spin states in odd-odd {sup 132}Cs

Energy Technology Data Exchange (ETDEWEB)

Hayakawa, Takehito [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment; Lu, J; Furuno, K [and others

1998-03-01

Excited states with spin larger than 5 {Dirac_h} were newly established in the {sup 132}Cs nucleus via the {sup 124}Sn({sup 11}B,3n) reaction. Rotational bands built on the {nu}h{sub 11/2} x {pi}d{sub 5/2}, {nu}h{sub 11/2} x {pi}g{sub 7/2} and {nu}h{sub 11/2} x {pi}h{sub 11/2} configurations were observed up to spin I {approx} 16 {Dirac_h}. The {nu}h{sub 11/2} x {pi}h{sub 11/2} band shows inverted signature splitting below I < 14 {Dirac_h}. A dipole band was firstly observed in doubly odd Cs nuclei. (author)

High-spin level scheme of odd-odd 142Pm

International Nuclear Information System (INIS)

Liu Minliang; Zhang Yuhu; Zhou Xiaohong; He Jianjun; Guo Yingxiang; Lei Xiangguo; Huang Wenxue; Liu Zhong; Luo Yixiao; Feng Xichen; Zhang Shuangquan; Xu Xiao; Zheng Yong; Luo Wanju

2002-01-01

The level structure of doubly odd nucleus 142 Pm has been studied via the 128 Te( 19 F, 5nγ) 142 Pm reaction in the energy region from 75 to 95 MeV. In-beam γ rays were measured including the excited function, γ-ray singles and γ-γ coincidences in experiment. The level scheme of 142 Pm has been extended up to excitation energy of 7030.0 keV including 25 new γ rays and 13 new levels. Based on the measured γ-ray anisotropies, the level spins in 142 Pm have been suggested

Dynamical symmetries for odd-odd nuclei

International Nuclear Information System (INIS)

Balantekin, A.B.

1986-01-01

Recent work for developing dynamical symmetries and supersymmetries is reviewed. An accurate description of odd-odd nuclei requires inclusion of the fermion-fermion force (the residual interaction) and the distinguishing of fermion configurations which are particle like and those which are hole like. A parabolic dependence of the proton-neutron multiplet in odd-odd nuclei is demonstrated. It is shown that a group structure for Bose-Fermi symmetries can be embedded in a supergroup. These methods are used to predict level schemes for Au-196 and Au-198. 11 refs., 3 figs

Covariant Density Functionals: time-odd channel investigated

International Nuclear Information System (INIS)

Afanasjev, A. V.; Abusara, H.

2009-01-01

The description of exotic nuclear systems and phenomena requires a detailed understanding of all channels of density functional theories. The role of time-odd mean fields, their evidence in experiment, and an accurate description of these fields are subject of current interest. Recent studies advanced the understanding of these fields in energy density functional theories based on the Skyrme force [1,2]. Time-odd mean fields are related to nuclear magnetism in covariant density functional (CDF) theories [3]. They arise from space-like components of vector mesons and Lorentz invariance requires that their coupling strengths are identical to that of time-like components. There were only few limited efforts to understand the role of time-odd mean fields in covariant density functional theory [4,5]. For example, the microscopic role of nuclear magnetism and its impact on rotational properties of nuclei has been studied in Ref. [5]. It is known that time-odd mean fields modify the angular momentum content of the single-particle orbitals and thus the moments of inertia, effective alignments, alignment gains at the band crossings and other physical observables. We aim on more detailed and systematic understanding of the role of time-odd mean fields in covariant density functional theory. This investigation covers both rotating and non-rotating systems. It is shown that contrary to the Skyrme energy density functionals time-odd mean fields of CDF theory always provide additional binding in the systems with broken time-reversal symmetry (rotating nuclei, odd mass nuclei). This additional binding increases with spin and has its maximum exactly at the terminating state [6], where it can reach several MeV. The impact of time-odd mean fields on the properties of rotating systems has been studied in a systematic way (as a function of particle number and deformation) across the nuclear chart [7]. In addition, this contribution extends these studies to non-rotating systems such as

Modeling of dislocation generation and interaction during high-speed deformation of metals

DEFF Research Database (Denmark)

Schiøtz, J.; Leffers, T.; Singh, B.N.

2002-01-01

Recent experiments by Kiritani et al. [1] have revealed a surprisingly high rate of vacancy production during highspeed deformation of thin foils of fcc metals. Virtually no dislocations are seen after the deformation. This is interpreted as evidence for a dislocation-free deformation mechanism...... at very high strain rates. We have used molecular-dynamics simulations to investigate high-speed deformation of copper crystals. Even though no pre-existing dislocation sources are present in the initial system, dislocations are quickly nucleated and a very high dislocation density is reached during...... the deformation. Due to the high density of dislocations, many inelastic interactions occur between dislocations, resulting in the generation of vacancies. After the deformation, a very high density of vacancies is observed, in agreement with the experimental observations. The processes responsible...

Nuclear orientation experiments concerning odd-A gold isotopes

International Nuclear Information System (INIS)

Ligthart, H.J.

1982-01-01

This thesis describes nuclear spectroscopy aspects of nuclear orientation in the odd-A gold isotopes 191 Au, 193 Au, 195 Au and 197 Au. These isotopes lie in a transitional region between the spherical nuclei in the lead region and the strongly deformed rare earth isotopes. Following a general introduction to nuclear orientation, the experimental arrangement is described. A new technique is presented that applies in-beam recoil implantation inside the refrigerator itself and this was applied to the case of 191 Au. The three other gold isotopes were oriented using a conventional dilution refrigerator. The nuclear orientation experiments concerning 11/2 - isomers of the isotopes are described. The long-lived isomeric states were oriented using the large hyperfine field of gold in iron. Higher lying levels were studied by nuclear orientation of the Hg parent states. (Auth./C.F.)

Twinning in copper deformed at high strain rates

Indian Academy of Sciences (India)

Abstract. Copper samples having varying microstructures were deformed at high strain rates using a split-. Hopkinson pressure bar. Transmission electron microscopy results show deformation twins present in samples that were both annealed and strained, whereas samples that were annealed and left unstrained, as well ...

gamma -transition rates in transitional odd gold nuclei

CERN Document Server

Berg, V; Oms, J

1981-01-01

The results of two half-life measurements of excited states in /sup 185/Au are presented. One supports the proposed interpretation of the ground state configuration, the other one calls attention to the h 9/2 to h 11/2 M1 transitions in odd mass gold nuclei, which, in spite of considerable deformation changes of the h 9/2 state, all show the same retardation. (5 refs).

Grain boundary engineering of highly deformable ceramics

International Nuclear Information System (INIS)

Mecartney, M.L.

2000-01-01

Highly deformable ceramics can be created with the addition of intergranular silicate phases. These amorphous intergranular phases can assist in superplastic deformation by relieving stress concentrations and minimizing grain growth if the appropriate intergranular compositions are selected. Examples from 3Y-TZP and 8Y-CSZ ceramics are discussed. The grain boundary chemistry is analyzed by high resolution analytical TEM is found to have a strong influence on the cohesion of the grains both at high temperature and at room temperature. Intergranular phases with a high ionic character and containing large ions with a relatively weak bond strength appear to cause premature failure. In contrast, intergranular phases with a high degree of covalent character and similar or smaller ions than the ceramic and a high ionic bond strength are the best for grain boundary adhesion and prevention of both cavitation at high temperatures and intergranular fracture at room temperature

High-temperature behavior of a deformed Fermi gas obeying interpolating statistics.

Science.gov (United States)

Algin, Abdullah; Senay, Mustafa

2012-04-01

An outstanding idea originally introduced by Greenberg is to investigate whether there is equivalence between intermediate statistics, which may be different from anyonic statistics, and q-deformed particle algebra. Also, a model to be studied for addressing such an idea could possibly provide us some new consequences about the interactions of particles as well as their internal structures. Motivated mainly by this idea, in this work, we consider a q-deformed Fermi gas model whose statistical properties enable us to effectively study interpolating statistics. Starting with a generalized Fermi-Dirac distribution function, we derive several thermostatistical functions of a gas of these deformed fermions in the thermodynamical limit. We study the high-temperature behavior of the system by analyzing the effects of q deformation on the most important thermostatistical characteristics of the system such as the entropy, specific heat, and equation of state. It is shown that such a deformed fermion model in two and three spatial dimensions exhibits the interpolating statistics in a specific interval of the model deformation parameter 0 < q < 1. In particular, for two and three spatial dimensions, it is found from the behavior of the third virial coefficient of the model that the deformation parameter q interpolates completely between attractive and repulsive systems, including the free boson and fermion cases. From the results obtained in this work, we conclude that such a model could provide much physical insight into some interacting theories of fermions, and could be useful to further study the particle systems with intermediate statistics.

Multi-quasiparticle high-K isomeric states in deformed nuclei

Directory of Open Access Journals (Sweden)

Xu F. R.

2016-01-01

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

Signature inversion of the semi-decoupled band in the odd-odd nucleus 170Ta

International Nuclear Information System (INIS)

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

2001-01-01

The high-spin states of the odd-odd nucleus 170 Ta have been studied by the 155 Gd( 19 F, 4n) 170 Ta reaction at the beam energy of 97 MeV. The α = 1 sequence of the semi-decoupled band has been pushed to higher-spin states and the signature inversion point was observed at 19.5 ℎ. the results are compared with those of the neighbouring odd-odd nuclei

High-Resolution Reciprocal Space Mapping for Characterizing Deformation Structures

DEFF Research Database (Denmark)

Pantleon, Wolfgang; Wejdemann, Christian; Jakobsen, Bo

2014-01-01

With high-angular resolution three-dimensional X-ray diffraction (3DXRD), quantitative information is gained about dislocation structures in individual grains in the bulk of a macroscopic specimen by acquiring reciprocal space maps. In high-resolution 3D reciprocal space maps of tensile......-deformed copper, individual, almost dislocation-free subgrains are identified from high-intensity peaks and distinguished by their unique combination of orientation and elastic strain; dislocation walls manifest themselves as a smooth cloud of lower intensity. The elastic strain shows only minor variations within...... dynamics is followed in situ during varying loading conditions by reciprocal space mapping: during uninterrupted tensile deformation, formation of subgrains is observed concurrently with broadening of Bragg reflections shortly after the onset of plastic deformation. When the traction is terminated, stress...

Highly deformable bones: unusual deformation mechanisms of seahorse armor.

Science.gov (United States)

Porter, Michael M; Novitskaya, Ekaterina; Castro-Ceseña, Ana Bertha; Meyers, Marc A; McKittrick, Joanna

2013-06-01

Multifunctional materials and devices found in nature serve as inspiration for advanced synthetic materials, structures and robotics. Here, we elucidate the architecture and unusual deformation mechanisms of seahorse tails that provide prehension as well as protection against predators. The seahorse tail is composed of subdermal bony plates arranged in articulating ring-like segments that overlap for controlled ventral bending and twisting. The bony plates are highly deformable materials designed to slide past one another and buckle when compressed. This complex plate and segment motion, along with the unique hardness distribution and structural hierarchy of each plate, provide seahorses with joint flexibility while shielding them against impact and crushing. Mimicking seahorse armor may lead to novel bio-inspired technologies, such as flexible armor, fracture-resistant structures or prehensile robotics. Copyright © 2013 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

Odd things, in odd places, in odd races | Ferndale | South African ...

African Journals Online (AJOL)

Odd things, in odd places, in odd races. L Ferndale, R Wise, S R Thomson. Abstract. No Abstract. South African Gastroenterology Vol. 5 (3) 2007: pp. 9-12. Full Text: EMAIL FULL TEXT EMAIL FULL TEXT · DOWNLOAD FULL TEXT DOWNLOAD FULL TEXT · http://dx.doi.org/10.4314/sagr.v5i3.30737 · AJOL African Journals ...

Studies of Stable Octupole Deformations in the Radium Region

CERN Multimedia

2002-01-01

The purpose of the present project is to locate and identify states in the atomic nuclei possessing stable pearshaped octupole deformation. Such states, formally related to the structures known in molecular physics, manifest themselves as families of parity doublets in odd nuclei.\\\\ \\\\ The best possibilities for observing stable octupole deformations are offered in the Ra-region. Both theoretical calculations and experimental indications support such expectations. Such indications are the non-observation of two-phonon octupole vibrational states in the ISOLDE studies of the even-even radium nuclei, and the reversed sign of the decoupling factor of the ground state band in |2|2|5Ra observed in the single-neutron transfer reactions. In order to establish the predicted strong E1 and E3-transitions between the parity doublets in odd nuclei with stable octupole deformations it is proposed to study conversion electrons in odd-mass francium radium and radon isotopes following the @b-decay of francium and astatine. \\...

Deformations of super Riemann surfaces

International Nuclear Information System (INIS)

Ninnemann, H.

1992-01-01

Two different approaches to (Konstant-Leites-) super Riemann surfaces are investigated. In the local approach, i.e. glueing open superdomains by superconformal transition functions, deformations of the superconformal structure are discussed. On the other hand, the representation of compact super Riemann surfaces of genus greater than one as a fundamental domain in the Poincare upper half-plane provides a simple description of super Laplace operators acting on automorphic p-forms. Considering purely odd deformations of super Riemann surfaces, the number of linear independent holomorphic sections of arbitrary holomorphic line bundles will be shown to be independent of the odd moduli, leading to a simple proof of the Riemann-Roch theorem for compact super Riemann surfaces. As a further consequence, the explicit connections between determinants of super Laplacians and Selberg's super zeta functions can be determined, allowing to calculate at least the 2-loop contribution to the fermionic string partition function. (orig.)

Deformations of super Riemann surfaces

Energy Technology Data Exchange (ETDEWEB)

Ninnemann, H [Hamburg Univ. (Germany). 2. Inst. fuer Theoretische Physik

1992-11-01

Two different approaches to (Konstant-Leites-) super Riemann surfaces are investigated. In the local approach, i.e. glueing open superdomains by superconformal transition functions, deformations of the superconformal structure are discussed. On the other hand, the representation of compact super Riemann surfaces of genus greater than one as a fundamental domain in the Poincare upper half-plane provides a simple description of super Laplace operators acting on automorphic p-forms. Considering purely odd deformations of super Riemann surfaces, the number of linear independent holomorphic sections of arbitrary holomorphic line bundles will be shown to be independent of the odd moduli, leading to a simple proof of the Riemann-Roch theorem for compact super Riemann surfaces. As a further consequence, the explicit connections between determinants of super Laplacians and Selberg's super zeta functions can be determined, allowing to calculate at least the 2-loop contribution to the fermionic string partition function. (orig.).

Large inelastic deformation analysis of steel pressure vessels at high temperature

International Nuclear Information System (INIS)

Ikonen, K.

2001-01-01

This publication describes the calculation methodology developed for a large inelastic deformation analysis of pressure vessels at high temperature. Continuum mechanical formulation related to a large deformation analysis is presented. Application of the constitutive equations is simplified when the evolution of stress and deformation state of an infinitesimal material element is considered in the directions of principal strains determined by the deformation during a finite time increment. A quantitative modelling of time dependent inelastic deformation is applied for reactor pressure vessel steels. Experimental data of uniaxial tensile, relaxation and creep tests performed at different laboratories for reactor pressure vessel steels are investigated and processed. An inelastic deformation rate model of strain hardening type is adopted. The model simulates well the axial tensile, relaxation and creep tests from room temperature to high temperature with only a few fitting parameters. The measurement data refined for the inelastic deformation rate model show useful information about inelastic deformation phenomena of reactor pressure vessel steels over a wide temperature range. The methodology and calculation process are validated by comparing the calculated results with measurements from experiments on small scale pressure vessels. A reasonably good agreement, when taking several uncertainties into account, is obtained between the measured and calculated results concerning deformation rate and failure location. (orig.)

Conflicting coupling of unpaired nucleons in odd-odd nuclei

International Nuclear Information System (INIS)

Volkov, D.A.; Levon, A.I.

1990-01-01

Phenomenological approach is described, using it, energy spectra of odd-odd nucleus collective bands based on conflicting state of unpaired nucleons can be calculated. It is ascertained that in a conflicting bond unpaired nucleon acts as a spectator, i.e. energy spectra of collective bands in odd-odd nuclei are similar to the spectra of collective bands in heighbouring odd nuclei, which are based on the state of a strongly bound nucleon is included in the conflicting configuration

a New Approach for Subway Tunnel Deformation Monitoring: High-Resolution Terrestrial Laser Scanning

Science.gov (United States)

Li, J.; Wan, Y.; Gao, X.

2012-07-01

With the improvement of the accuracy and efficiency of laser scanning technology, high-resolution terrestrial laser scanning (TLS) technology can obtain high precise points-cloud and density distribution and can be applied to high-precision deformation monitoring of subway tunnels and high-speed railway bridges and other fields. In this paper, a new approach using a points-cloud segmentation method based on vectors of neighbor points and surface fitting method based on moving least squares was proposed and applied to subway tunnel deformation monitoring in Tianjin combined with a new high-resolution terrestrial laser scanner (Riegl VZ-400). There were three main procedures. Firstly, a points-cloud consisted of several scanning was registered by linearized iterative least squares approach to improve the accuracy of registration, and several control points were acquired by total stations (TS) and then adjusted. Secondly, the registered points-cloud was resampled and segmented based on vectors of neighbor points to select suitable points. Thirdly, the selected points were used to fit the subway tunnel surface with moving least squares algorithm. Then a series of parallel sections obtained from temporal series of fitting tunnel surfaces were compared to analysis the deformation. Finally, the results of the approach in z direction were compared with the fiber optical displacement sensor approach and the results in x, y directions were compared with TS respectively, and comparison results showed the accuracy errors of x, y, z directions were respectively about 1.5 mm, 2 mm, 1 mm. Therefore the new approach using high-resolution TLS can meet the demand of subway tunnel deformation monitoring.

Free energy on a cycle graph and trigonometric deformation of heat kernel traces on odd spheres

Science.gov (United States)

Kan, Nahomi; Shiraishi, Kiyoshi

2018-01-01

We consider a possible ‘deformation’ of the trace of the heat kernel on odd dimensional spheres, motivated by the calculation of the free energy of a scalar field on a discretized circle. By using an expansion in terms of the modified Bessel functions, we obtain the values of the free energies after a suitable regularization.

Time-odd mean fields in covariant density functional theory: Rotating systems

International Nuclear Information System (INIS)

Afanasjev, A. V.; Abusara, H.

2010-01-01

Time-odd mean fields (nuclear magnetism) and their impact on physical observables in rotating nuclei are studied in the framework of covariant density functional theory (CDFT). It is shown that they have profound effect on the dynamic and kinematic moments of inertia. Particle number, configuration, and rotational frequency dependencies of their impact on the moments of inertia have been analyzed in a systematic way. Nuclear magnetism can also considerably modify the band crossing features such as crossing frequencies and the properties of the kinematic and dynamic moments of inertia in the band crossing region. The impact of time-odd mean fields on the moments of inertia in the regions away from band crossing only weakly depends on the relativistic mean-field parametrization, reflecting good localization of the properties of time-odd mean fields in CDFT. The moments of inertia of normal-deformed nuclei considerably deviate from the rigid-body value. On the contrary, superdeformed and hyperdeformed nuclei have the moments of inertia which are close to rigid-body value. The structure of the currents in rotating frame, their microscopic origin, and the relations to the moments of inertia have been systematically analyzed. The phenomenon of signature separation in odd-odd nuclei, induced by time-odd mean fields, has been analyzed in detail.

Deformation and shape coexistence in medium mass nuclei

International Nuclear Information System (INIS)

Meyer, R.A.

1985-01-01

Emerging evidence for deformed structures in medium mass nuclei is reviewed. Included in this review are both nuclei that are ground state symmetric rotors and vibrational nuclei where there are deformed structures at excited energies (shape coexistence). For the first time, Nilsson configurations in odd-odd nuclei within the region of deformation are identified. Shape coexistence in nuclei that abut the medium mass region of deformation is also examined. Recent establishment of a four-particle, four-hole intruder band in the double subshell closure nucleus 96 Zr 56 is presented and its relation to the nuclear vibron model is discussed. Special attention is given to the N=59 nuclei where new data have led to the reanalysis of 97 Sr and 99 Zr and the presence of the [404 9/2] hole intruder state as isomers in these nuclei. The low energy levels of the N=59 nuclei from Z=38 to 50 are compared with recent quadrupole-phonon model calculations that can describe their transition from near-rotational to single closed shell nuclei. The odd-odd N=59 nuclei are discussed in the context of coexisting shape isomers based on the (p[303 5/2]n[404 9/2])2 - configuration. Ongoing in-beam (t,p conversion-electron) multiparameter measurements that have led to the determination of monopole matrix elements for even-even 42 Mo nuclei are presented, and these are compared with initial estimates using IBA-2 calculations that allow mixing of normal and cross subshell excitations. Lastly, evidence for the neutron-proton 3 S 1 force's influence on the level structure of these nuclei is discussed within the context of recent quadrupole-phonon model calculations. (Auth.)

High temperature deformation behavior and microstructural evolutions of a high Zr containing WE magnesium alloy

Energy Technology Data Exchange (ETDEWEB)

Asqardoust, Sh.; Zarei-Hanzaki, A. [School of Metallurgical & Materials Engineering, University of Tehran, Tehran (Iran, Islamic Republic of); Fatemi, S.M., E-mail: mfatemi@ut.ac.ir [Shahid Rajaee Teacher Training University, Tehran (Iran, Islamic Republic of); Moradjoy-Hamedani, M. [School of Metallurgical & Materials Engineering, University of Tehran, Tehran (Iran, Islamic Republic of)

2016-06-05

Magnesium alloys containing RE elements (WE grade) are considered as potential materials for high temperature structural applications. To this end, it is crucial to study the flow behavior and the microstructural evolution of these alloys at high temperatures. In present work, the hot compression testing was employed to investigate the deformation behavior of a rolled WE54 magnesium alloy at elevated temperatures. The experimental material failed to deform to target strain of 0.6 at 250 and 300 °C, while the straining was successfully performed at 350 °C. A flow softening was observed at 350 °C, which was related to the depletion of RE strengthener elements, particularly Y atoms, from the solid solution and dynamic precipitation of β phases. It was suggested that the Zener pinning effect of the latter precipitates might retard the occurrence of dynamic recrystallization. As the temperature increased to 450 and 500 °C, the RE elements dissolved in the matrix and thus dynamic recrystallization could considerably progress in the microstructure. The comparative study of specimens cut along transverse ad normal direction (TD and ND specimens) implied that the presence of RE elements might effectively reduce the yield anisotropy in WE54 rolled alloy. Microstructural observations indicated a higher fraction of dynamically-recrystallized grains for the ND specimens. This was discussed relying on the different shares of deformation mechanism during compressing the TD and ND specimens. - Highlights: • Deformation behavior of a high Zr WE alloy was addressed at low strain rate. • Dynamic precipitation was realized at 350 °C. • The occurrence of DRX was retarded due to Zener pinning effect. • A higher DRX fraction was obtained in ND specimens comparing with TD ones.

Wavelet analysis deformation monitoring data of high-speed railway bridge

Science.gov (United States)

Tang, ShiHua; Huang, Qing; Zhou, Conglin; Xu, HongWei; Liu, YinTao; Li, FeiDa

2015-12-01

Deformation monitoring data of high-speed railway bridges will inevitably be affected because of noise pollution, A deformation monitoring point of high-speed railway bridge was measurd by using sokkia SDL30 electronic level for a long time,which got a large number of deformation monitoring data. Based on the characteristics of the deformation monitoring data of high-speed railway bridge, which contain lots of noise. Based on the MATLAB software platform, 120 groups of deformation monitoring data were applied to analysis of wavelet denoising.sym6,db6 wavelet basis function were selected to analyze and remove the noise.The original signal was broken into three layers wavelet,which contain high frequency coefficients and low frequency coefficients.However, high frequency coefficient have plenty of noise.Adaptive method of soft and hard threshold were used to handle in the high frequency coefficient.Then,high frequency coefficient that was removed much of noise combined with low frequency coefficient to reconstitute and obtain reconstruction wavelet signal.Root Mean Square Error (RMSE) and Signal-To-Noise Ratio (SNR) were regarded as evaluation index of denoising,The smaller the root mean square error and the greater signal-to-noise ratio indicate that them have a good effect in denoising. We can surely draw some conclusions in the experimental analysis:the db6 wavelet basis function has a good effect in wavelet denoising by using a adaptive soft threshold method,which root mean square error is minimum and signal-to-noise ratio is maximum.Moreover,the reconstructed image are more smooth than original signal denoising after wavelet denoising, which removed noise and useful signal are obtained in the original signal.Compared to the other three methods, this method has a good effect in denoising, which not only retain useful signal in the original signal, but aiso reach the goal of removing noise. So, it has a strong practical value in a actual deformation monitoring

A NEW APPROACH FOR SUBWAY TUNNEL DEFORMATION MONITORING: HIGH-RESOLUTION TERRESTRIAL LASER SCANNING

Directory of Open Access Journals (Sweden)

J. Li

2012-07-01

Full Text Available With the improvement of the accuracy and efficiency of laser scanning technology, high-resolution terrestrial laser scanning (TLS technology can obtain high precise points-cloud and density distribution and can be applied to high-precision deformation monitoring of subway tunnels and high-speed railway bridges and other fields. In this paper, a new approach using a points-cloud segmentation method based on vectors of neighbor points and surface fitting method based on moving least squares was proposed and applied to subway tunnel deformation monitoring in Tianjin combined with a new high-resolution terrestrial laser scanner (Riegl VZ-400. There were three main procedures. Firstly, a points-cloud consisted of several scanning was registered by linearized iterative least squares approach to improve the accuracy of registration, and several control points were acquired by total stations (TS and then adjusted. Secondly, the registered points-cloud was resampled and segmented based on vectors of neighbor points to select suitable points. Thirdly, the selected points were used to fit the subway tunnel surface with moving least squares algorithm. Then a series of parallel sections obtained from temporal series of fitting tunnel surfaces were compared to analysis the deformation. Finally, the results of the approach in z direction were compared with the fiber optical displacement sensor approach and the results in x, y directions were compared with TS respectively, and comparison results showed the accuracy errors of x, y, z directions were respectively about 1.5 mm, 2 mm, 1 mm. Therefore the new approach using high-resolution TLS can meet the demand of subway tunnel deformation monitoring.

High strain rate deformation of layered nanocomposites

Science.gov (United States)

Lee, Jae-Hwang; Veysset, David; Singer, Jonathan P.; Retsch, Markus; Saini, Gagan; Pezeril, Thomas; Nelson, Keith A.; Thomas, Edwin L.

2012-11-01

Insight into the mechanical behaviour of nanomaterials under the extreme condition of very high deformation rates and to very large strains is needed to provide improved understanding for the development of new protective materials. Applications include protection against bullets for body armour, micrometeorites for satellites, and high-speed particle impact for jet engine turbine blades. Here we use a microscopic ballistic test to report the responses of periodic glassy-rubbery layered block-copolymer nanostructures to impact from hypervelocity micron-sized silica spheres. Entire deformation fields are experimentally visualized at an exceptionally high resolution (below 10 nm) and we discover how the microstructure dissipates the impact energy via layer kinking, layer compression, extreme chain conformational flattening, domain fragmentation and segmental mixing to form a liquid phase. Orientation-dependent experiments show that the dissipation can be enhanced by 30% by proper orientation of the layers.

High strain rate deformation of layered nanocomposites.

Science.gov (United States)

Lee, Jae-Hwang; Veysset, David; Singer, Jonathan P; Retsch, Markus; Saini, Gagan; Pezeril, Thomas; Nelson, Keith A; Thomas, Edwin L

2012-01-01

Insight into the mechanical behaviour of nanomaterials under the extreme condition of very high deformation rates and to very large strains is needed to provide improved understanding for the development of new protective materials. Applications include protection against bullets for body armour, micrometeorites for satellites, and high-speed particle impact for jet engine turbine blades. Here we use a microscopic ballistic test to report the responses of periodic glassy-rubbery layered block-copolymer nanostructures to impact from hypervelocity micron-sized silica spheres. Entire deformation fields are experimentally visualized at an exceptionally high resolution (below 10 nm) and we discover how the microstructure dissipates the impact energy via layer kinking, layer compression, extreme chain conformational flattening, domain fragmentation and segmental mixing to form a liquid phase. Orientation-dependent experiments show that the dissipation can be enhanced by 30% by proper orientation of the layers.

First observation of yrast band in odd-odd 162Lu

International Nuclear Information System (INIS)

Zhang, Y.H.; Yuan, G.J.; Liu, X.A.

1996-01-01

High spin states of the odd-odd 162 Lu nucleus have been studied via 147 Sm( 19 F, 4nγ) 162 Lu reaction at 95MeV beam energy. Level scheme for yrast band based on π[h 11/2 ] υ[i 13/2 ] quasiparticle configuration was established up to I π =(23 - ) for the first time. This band shows the signature inversion in energy before backbending generally appeared in this mass region. It is stressed that the signature splitting in 162 Lu is larger than that in the 160 Tm nucleus. (orig.)

Magnetic dipole moments of odd-odd lanthanides

International Nuclear Information System (INIS)

Sharma, S.D.; Gandhi, R.

1988-01-01

Magnetic dipole moments of odd-odd lanthanides. Collective model of odd-odd nuclei is applied to predict the magnetic dipole moments, (μ) of odd-odd lanthanides. A simplified version of expression for μ based on diagonalisation of Hamiltonian (subsequent use of eigenvectors to compute μ) is developed for cases of ground state as well as excited states using no configuration mixing and is applied to the cases of odd-odd lanthanides. The formulae applied to the eleven (11) cases of ground states show significant improvement over the results obtained using shell model. Configuration mixing and coriolis coupling is expected to cause further improvement in the results. On comparing the earlier work in this direction the present analysis has clarified that in the expression μ the projection factors have different signs for the case I=Ωp - Ωn and I=Ωn - Ωp, and sign of μ is negative in general in the second case while it is positive in all others of spin projection alignments. Although the general expression holds for excited states as well but in lanthanide region, the experimental reports of magnetic dipole moments of excite states (band heads of higher rational sequences) are not available except in case of five (5) neutron resonance states which cannot be handled on the basis of the present approach with no configuration mixing. Although in the present discussion, the model could not be applied to excited states but the systematics of change in its magnitude with increasing spin at higher rational states is very well understood. The particle part supressed under faster rotation of the nuclear core and thus finally at higher spin I, the value μ is given by μ=g c I (same as in case of even-even nuclei). These systematics are to be verified whenever enough data for higher excited states are available. (author). 11 refs

A STUDY OF THE PRESSURE SOLUTION AND DEFORMATION OF QUARTZ CRYSTALS AT HIGH pH AND UNDER HIGH STRESS

Directory of Open Access Journals (Sweden)

JUNG-HAE CHOI

2013-02-01

Full Text Available Bentonite is generally used as a buffer material in high-level radioactive waste disposal facilities and consists of 50% quartz by weight. Quartz strongly affects the behavior of bentonite over very long periods. For this reason, quartz dissolution experiment was performed under high-pressure and high-alkalinity conditions based on the conditions found in a high-level radioactive waste disposal facility located deep underground. In this study, two quartz dissolution experiments were conducted on 1 quartz beads under low-pressure and high-alkalinity conditions and 2 a single quartz crystal under high-pressure and high-alkalinity conditions. Following the experiments, a confocal laser scanning microscope (CLSM was used to observe the surfaces of experimental samples. Numerical analyses using the finite element method (FEM were also performed to quantify the deformation of contact area. Quartz dissolution was observed in both experiments. This deformation was due to a concentrated compressive stress field, as indicated by the quartz deformation of the contact area through the FEM analysis. According to the numerical results, a high compressive stress field acted upon the neighboring contact area, which showed a rapid dissolution rate compared to other areas of the sample.

High performance deformable image registration algorithms for manycore processors

CERN Document Server

Shackleford, James; Sharp, Gregory

2013-01-01

High Performance Deformable Image Registration Algorithms for Manycore Processors develops highly data-parallel image registration algorithms suitable for use on modern multi-core architectures, including graphics processing units (GPUs). Focusing on deformable registration, we show how to develop data-parallel versions of the registration algorithm suitable for execution on the GPU. Image registration is the process of aligning two or more images into a common coordinate frame and is a fundamental step to be able to compare or fuse data obtained from different sensor measurements. E

A new dynamic recrystallisation model of an extruded Al-Cu-Li alloy during high-temperature deformation

Energy Technology Data Exchange (ETDEWEB)

Shen, Bo; Deng, Lei; Wang, Xinyun, E-mail: wangxy_hust@163.com

2015-02-11

The high-temperature deformation behaviour and microstructure evolution of an extruded Al-Cu-Li alloy were investigated by compression tests conducted at various temperatures (613, 673 and 733 K) with various strain rates (0.001, 0.01, and 0.1 s{sup -1}). The results indicated that the deformation activation energy increased from 208.7 kJ/mol to 255.7 kJ/mol with an increase in strain from 0.1 to 0.7. The electron backscatter diffraction maps indicated that a dynamic recrystallisation occurred during the high-temperature deformation. Two types of recrystallisation mechanisms, grain boundary bulging and a grain boundary transformation from low misorientation to high misorientation, were considered as the mechanisms for controlling the formation of the recrystallised grains. A new dynamic recrystallisation model containing these two mechanisms was proposed to describe the microstructure evolution of the extruded Al-Cu-Li alloy. At the early stage of the deformation, the recrystallised grains were formed by grain boundary bulging along the original grain boundaries. With increasing strain, recrystallised grains were gradually generated in the deformed grains due to the transformation from low angle boundaries to high angle boundaries.

Large odd-even staggering in the very light platinum isotopes from laser spectroscopy

CERN Document Server

Le Blanc, F; Cabaret, L A; Crawford, J E; Duong, H T; Genevey, J; Girod, M; Huber, G; Krieg, M; Lee, J K P; Lettry, Jacques; Lunney, M D; Obert, J; Oms, J; Peru, S; Putaux, J C; Roussière, B; Sauvage, J; Sebastian, V; Zemlyanoi, S G

1998-01-01

Laser spectroscopy measurements have been carried out on very neutron-deficient platinum isotopes with the COMPLIS experimental set-up on line with the ISOLDE-Booster facility. For the first time, Hg alpha -decay was exploited to extend the very light platinum chain. Using the 5d/sup 9/6s /sup 3/D/sub 3/ to 5d/sup 9/6p /sup 3/P /sub 2/ optical transition, hyperfine spectra of /sup 182,181,180,179,178/Pt and /sup 183/Pt/sup m/ were recorded for the first time. The variation of the mean square charge radius between these nuclei, the magnetic moments of the odd isotopes and the quadrupole moment of /sup 183/Pt/sup m/ were thus measured. A large deformation change between /sup 183/Pt/sup 9/ and /sup 183/Pt/sup m/, an odd-even staggering of the charge radius and a deformation drop from A=179 are clearly observed. All these results are discussed and compared with microscopic theoretical predictions using Hartree-Fock- Bogolyubov calculations using the Gogny force. (20 refs).

Nuclear quantum shape-phase transitions in odd-mass systems

Science.gov (United States)

Quan, S.; Li, Z. P.; Vretenar, D.; Meng, J.

2018-03-01

Microscopic signatures of nuclear ground-state shape-phase transitions in odd-mass Eu isotopes are explored starting from excitation spectra and collective wave functions obtained by diagonalization of a core-quasiparticle coupling Hamiltonian based on energy density functionals. As functions of the physical control parameter—the number of nucleons—theoretical low-energy spectra, two-neutron separation energies, charge isotope shifts, spectroscopic quadrupole moments, and E 2 reduced transition matrix elements accurately reproduce available data and exhibit more-pronounced discontinuities at neutron number N =90 compared with the adjacent even-even Sm and Gd isotopes. The enhancement of the first-order quantum phase transition in odd-mass systems can be attributed to a shape polarization effect of the unpaired proton which, at the critical neutron number, starts predominantly coupling to Gd core nuclei that are characterized by larger quadrupole deformation and weaker proton pairing correlations compared with the corresponding Sm isotopes.

Systematics of triaxial deformation in Xe, Ba, and Ce nuclei

International Nuclear Information System (INIS)

Yan, J.; Vogel, O.; von Brentano, P.; Gelberg, A.

1993-01-01

The (β,γ) deformation parameters of even-even Xe, Ba, and Ce nuclei have been calculated by using the triaxial rotor model. Deformation parameters calculated, on one hand, from decay properties and, on the other hand, from energies are in good agreement. The smooth dependence of the deformation parameters on Z and N is discussed. The results are compared with those extracted from properties of odd-A nuclei

An experimental study of odd mass promethium isotopes using proton stripping and pickup reactions

International Nuclear Information System (INIS)

Straume, O.

1979-11-01

Odd Pm isotopes have been studied by one proton pick-up and stripping reactions. Spin assignment and spectroscopic factors have been obtained for a number of energy levels. In the stripping reactions, the relative cross-sections have been measured with an unusually high precision by the use of a target of natural neodymium. The spectroscopic strengths have been extracted using standard distorted wave methods. The nuclear structures of these promethium isotopes fall into three categories. The spherical approach seems valid for 143 Pm and 145 Pm and the deformed regime covers 151 Pm and 153 Pm, while 147 Pm and 149 Pm remain as transitional nuclei. (Auth.)

Study of phase transition of even and odd nuclei based on q-deforme SU(1,1) algebraic model

Science.gov (United States)

Jafarizadeh, M. A.; Amiri, N.; Fouladi, N.; Ghapanvari, M.; Ranjbar, Z.

2018-04-01

The q-deformed Hamiltonian for the SO (6) ↔ U (5) transitional case in s, d interaction boson model (IBM) can be constructed by using affine SUq (1 , 1) Lie algebra in the both IBM-1 and 2 versions and IBFM. In this research paper, we have studied the energy spectra of 120-128Xe isotopes and 123-131Xe isotopes and B(E2) transition probabilities of 120-128Xe isotopes in the shape phase transition region between the spherical and gamma unstable deformed shapes of the theory of quantum deformation. The theoretical results agree with the experimental data fairly well. It is shown that the q-deformed SO (6) ↔ U (5) transitional dynamical symmetry remains after deformation.

High resolution, large deformation 3D traction force microscopy.

Directory of Open Access Journals (Sweden)

Jennet Toyjanova

Full Text Available Traction Force Microscopy (TFM is a powerful approach for quantifying cell-material interactions that over the last two decades has contributed significantly to our understanding of cellular mechanosensing and mechanotransduction. In addition, recent advances in three-dimensional (3D imaging and traction force analysis (3D TFM have highlighted the significance of the third dimension in influencing various cellular processes. Yet irrespective of dimensionality, almost all TFM approaches have relied on a linear elastic theory framework to calculate cell surface tractions. Here we present a new high resolution 3D TFM algorithm which utilizes a large deformation formulation to quantify cellular displacement fields with unprecedented resolution. The results feature some of the first experimental evidence that cells are indeed capable of exerting large material deformations, which require the formulation of a new theoretical TFM framework to accurately calculate the traction forces. Based on our previous 3D TFM technique, we reformulate our approach to accurately account for large material deformation and quantitatively contrast and compare both linear and large deformation frameworks as a function of the applied cell deformation. Particular attention is paid in estimating the accuracy penalty associated with utilizing a traditional linear elastic approach in the presence of large deformation gradients.

Expressway deformation mapping using high-resolution TerraSAR-X images

KAUST Repository

Shi, Xuguo

2014-01-27

Monitoring deformation of linear infrastructures such as expressway and railway caused by natural processes or anthropogenic activities is a vital task to ensure the safety of human lives and properties. Interferometric Synthetic Aperture Radar (InSAR) has been widely recognized as an effective technology to carry out large-area surface deformation mapping. However, its application in linear infrastructure deformation monitoring has not been intensively studied till now. In this article, a modified Small BAseline Subset (SBAS) method is proposed to retrieve the deformation patterns of the expressway. In our method, only the point-like targets identified on the expressway were kept in our analysis, and two complementary subsets of interferograms were formed to better separate the signals of height error and deformation from inteferometric phase observations. We successfully applied this method with multitemporal high-resolution TerraSAR-X images to retrieve the spatialoral pattern of surface deformation along the Beian-Heihe expressway that is located in island-permafrost areas and threatened by geohazards. © 2014 Taylor & Francis.

Expressway deformation mapping using high-resolution TerraSAR-X images

KAUST Repository

Shi, Xuguo; Liao, Mingsheng; Wang, Teng; Zhang, Lu; Shan, Wei; Wang, Chunjiao

2014-01-01

Monitoring deformation of linear infrastructures such as expressway and railway caused by natural processes or anthropogenic activities is a vital task to ensure the safety of human lives and properties. Interferometric Synthetic Aperture Radar (InSAR) has been widely recognized as an effective technology to carry out large-area surface deformation mapping. However, its application in linear infrastructure deformation monitoring has not been intensively studied till now. In this article, a modified Small BAseline Subset (SBAS) method is proposed to retrieve the deformation patterns of the expressway. In our method, only the point-like targets identified on the expressway were kept in our analysis, and two complementary subsets of interferograms were formed to better separate the signals of height error and deformation from inteferometric phase observations. We successfully applied this method with multitemporal high-resolution TerraSAR-X images to retrieve the spatialoral pattern of surface deformation along the Beian-Heihe expressway that is located in island-permafrost areas and threatened by geohazards. © 2014 Taylor & Francis.

Deformation of contact surfaces in a vacuum interrupter after high-current interruptions

Energy Technology Data Exchange (ETDEWEB)

Wang, Haoran; Wang, Zhenxing, E-mail: zxwang@xjtu.edu.cn; Zhou, Zhipeng; Jiang, Yanjun; Wang, Jianhua; Geng, Yingsan; Liu, Zhiyuan [State Key Laboratory of Electrical Insulation and Power Equipment, Xi' an Jiaotong University, Xi' an 710049 (China)

2016-08-07

In a high-current interruption, the contact surface in a vacuum interrupter might be severely damaged by constricted vacuum arcs causing a molten area on it. As a result, a protrusion will be initiated by a transient recovery voltage after current zero, enhancing the local electric field and making breakdowns occur easier. The objective of this paper is to simulate the deformation process on the molten area under a high electric field by adopting the finite element method. A time-dependent Electrohydrodynamic model was established, and the liquid-gas interface was tracked by the level-set method. From the results, the liquid metal can be deformed to a Taylor cone if the applied electric field is above a critical value. This value is correlated to the initial geometry of the liquid metal, which increases as the size of the liquid metal decreases. Moreover, the buildup time of a Taylor cone obeys the power law t = k × E{sup −3}, where E is the initial electric field and k is a coefficient related to the material property, indicating a temporal self-similar characteristic. In addition, the influence of temperature has little impact on the deformation but has great impact on electron emission. Finally, the possible reason to initiate a delayed breakdown is associated with the deformation. The breakdown does not occur immediately when the voltage is just applied upon the gap but is postponed to several milliseconds later when the tip is formed on the liquid metal.

Layers of deformed instantons in holographic baryonic matter

Energy Technology Data Exchange (ETDEWEB)

Preis, Florian [Institut für Theoretische Physik, Technische Universität Wien,1040 Vienna (Austria); Schmitt, Andreas [Mathematical Sciences and STAG Research Centre, University of Southampton,Southampton SO17 1BJ (United Kingdom)

2016-07-01

We discuss homogeneous baryonic matter in the decompactified limit of the Sakai-Sugimoto model, improving existing approximations based on flat-space instantons. We allow for an anisotropic deformation of the instantons in the holographic and spatial directions and for a density-dependent distribution of arbitrarily many instanton layers in the bulk. Within our approximation, the baryon onset turns out to be a second-order phase transition, at odds with nature, and there is no transition to quark matter at high densities, at odds with expectations from QCD. This changes when we impose certain constraints on the shape of single instantons, motivated by known features of holographic baryons in the vacuum. Then, a first-order baryon onset and chiral restoration at high density are possible, and at sufficiently large densities two instanton layers are formed dynamically. Our results are a further step towards describing realistic, strongly interacting matter over a large density regime within a single model, desirable for studies of compact stars.

Deformation Monitoring of Geomechanical Model Test and Its Application in Overall Stability Analysis of a High Arch Dam

Directory of Open Access Journals (Sweden)

Baoquan Yang

2015-01-01

Full Text Available Geomechanical model testing is an important method for studying the overall stability of high arch dams. The main task of a geomechanical model test is deformation monitoring. Currently, many types of deformation instruments are used for deformation monitoring of dam models, which provide valuable information on the deformation characteristics of the prototype dams. However, further investigation is required for assessing the overall stability of high arch dams through analyzing deformation monitoring data. First, a relationship for assessing the stability of dams is established based on the comprehensive model test method. Second, a stability evaluation system is presented based on the deformation monitoring data, together with the relationships between the deformation and overloading coefficient. Finally, the comprehensive model test method is applied to study the overall stability of the Jinping-I high arch dam. A three-dimensional destructive test of the geomechanical model dam is conducted under reinforced foundation conditions. The deformation characteristics and failure mechanisms of the dam abutments and foundation were investigated. The test results indicate that the stability safety factors of the dam abutments and foundation range from 5.2 to 6.0. These research results provide an important scientific insight into the design, construction, and operation stages of this project.

Coulomb and even-odd effects in cold and super-asymmetric fragmentation for thermal neutron induced fission of {sup 235}U

Energy Technology Data Exchange (ETDEWEB)

Montoya, M. [Universidad Nacional de Ingeniería, Av. Túpac Amaru 210, Rímac, Lima (Peru)

2016-07-07

Even-odd effects of the maximal total kinetic energy (K{sub max}) as a function of charge (Z) and mass (A) of fragments from thermal neutron induced fission of actinides are questioned by other authors. In this work, visiting old results on thermal neutron induced fission of {sup 235}U, those even-odd effects are reconfirmed. The cases seeming to contradict even-odd effects are interpreted with the Coulomb effect hypothesis. According to Coulomb effect hypothesis, K{sub max} is equal to the Coulomb interaction energy of the most compact scission configuration. As a consequence, between two isobaric charge splits with similar Q-values, the more asymmetrical one will get the more compact scission configuration and then it will reach the higher K{sub max}-value. In some cases, the more asymmetrical charge split corresponds, by coincidence, to an odd charge split; consequently its higher K{sub max}-value may be misinterpreted as anti-even-odd effect. Another experimental result reported in the literature is the increasing of even-odd effects on charge distribution on the more asymmetrical fragmentations region. In this region, the difference between K{sub max} and Q-values increases with asymmetry, which means that the corresponding scission configuration needs higher total deformation energy to occur. Higher deformation energy of the fragments implies lower free energy to break nucleon pairs. Consequently, in the asymmetric fragmentation region, the even-odd effects of the distribution of proton number and neutron number must increase with asymmetry.

Coulomb Excitation of Odd-Mass and Odd-Odd Cu Isotopes using REX-ISOLDE and Miniball

CERN Multimedia

Lauer, M; Iwanicki, J S

2002-01-01

We propose to study the properties of the odd-mass and the odd-odd neutron-rich Cu nuclei applying the Coulomb excitation technique and using the REX-ISOLDE facility coupled to the Miniball array. The results from the Coulex experiments accomplished at REX-ISOLDE after its upgrade to 3 MeV/u during the last year have shown the power of this method and its importance in order to obtain information on the collective properties of even-even nuclei. Performing an experiment on the odd-mass and on the odd-odd neutron-rich Cu isotopes in the vicinity of N=40 should allow us to determine and interpret the effective proton and neutron charges in the region and to unravel the lowest proton-neutron multiplets in $^{68,70}$Cu. This experiment can take the advantage of the unique opportunity to accelerate isomerically separated beams using the RILIS ion source at ISOLDE.

On the octupole deformation in Ra-Th region

International Nuclear Information System (INIS)

Rozmej, P.; Boening, K.; Sobiczewski, A.

1986-03-01

The problem of the existence of a stable octupole deformation in Ra-Th region has been reinvestigated using a Nilsson single-particle potential with a newly fitted set of parameters, which reproduce the spins of the ground states of odd-A nuclei. In the energy surfaces, calculated for 222 Ra and 222 Th, the octupole deformed minima, separated by the barriers of 150 KeV and 210 keV, respectively, have been obtained. (orig.)

Prevalence of self-reported finger deformations and occupational risk factors among professional cooks: a cross-sectional study.

Science.gov (United States)

Nagasu, Miwako; Sakai, Kazuhiro; Kogi, Kazutaka; Ito, Akiyoshi; Feskens, Edith J M; Tomita, Shigeru; Temmyo, Yoshiomi; Ueno, Mitsuo; Miyagi, Shigeji

2011-05-26

Previous studies have pointed out that the school lunch workers in Japan are suffering from work-related disorders including finger deformations. The purpose of this study was to investigate the prevalence of self-reported finger deformations and the association with job-related risk factors. A cross-sectional questionnaire study of 5,719 subjects (response rate: 81%, 982 men and 4,737 women) was undertaken during September 2003 to February 2004. Finger deformations were found among 11.7% of the men and 35.6% of the women studied, with significant differences among sex, age and sex-age groups. For both men and women the pattern of finger deformations across the hand was similar for the right and the left hand. For women, the deformations were found in about 10% of the distal interphalangeal joints of all fingers. Based on multiple logistic regression analyses, the factors female sex, age, the number of cooked lunches per cook and cooking activities were independently associated with the prevalence of finger deformations. High prevalence odds ratios were found for those frequently carrying or using tools by hands such as delivering containers, distributing meals, preparing dishes, washing equipment, cutting and stirring foods. Among the school lunch workers studied, women had a higher prevalence of finger deformations on all joints of both hands. Various cooking tasks were associated with the prevalence of finger deformations. The results suggest that improvements in working conditions are important for preventing work-related disorders such as finger deformations.

a Method for the Extraction of Long-Term Deformation Characteristics of Long-Span High-Speed Railway Bridges Using High-Resolution SAR Images

Science.gov (United States)

Jia, H. G.; Liu, L. Y.

2016-06-01

Natural causes and high-speed train load will result in the structural deformation of long-span bridges, which greatly influence the safety operation of high-speed railway. Hence it is necessary to conduct the deformation monitoring and regular status assessment for long-span bridges. However for some traditional surveying technique, e.g. control-point-based surveying techniques, a lot of human and material resources are needed to perform the long-term monitoring for the whole bridge. In this study we detected the long-term bridge deformation time-series by persistent scatterer interferometric synthetic aperture radar (PSInSAR) technique using the high-resolution SAR images and external digital elevation model. A test area in Nanjing city in China is chosen and TerraSAR-X images and Tandem-X for this area have been used. There is the Dashengguan bridge in high speed railway in this area as study object to evaluate this method. Experiment results indicate that the proposed method can effectively extract the long-term deformation of long-span high-speed railway bridge with higher accuracy.

A METHOD FOR THE EXTRACTION OF LONG-TERM DEFORMATION CHARACTERISTICS OF LONG-SPAN HIGH-SPEED RAILWAY BRIDGES USING HIGH-RESOLUTION SAR IMAGES

Directory of Open Access Journals (Sweden)

H. G. Jia

2016-06-01

Full Text Available Natural causes and high-speed train load will result in the structural deformation of long-span bridges, which greatly influence the safety operation of high-speed railway. Hence it is necessary to conduct the deformation monitoring and regular status assessment for long-span bridges. However for some traditional surveying technique, e.g. control-point-based surveying techniques, a lot of human and material resources are needed to perform the long-term monitoring for the whole bridge. In this study we detected the long-term bridge deformation time-series by persistent scatterer interferometric synthetic aperture radar (PSInSAR technique using the high-resolution SAR images and external digital elevation model. A test area in Nanjing city in China is chosen and TerraSAR-X images and Tandem-X for this area have been used. There is the Dashengguan bridge in high speed railway in this area as study object to evaluate this method. Experiment results indicate that the proposed method can effectively extract the long-term deformation of long-span high-speed railway bridge with higher accuracy.

Error statistics in a high-speed fibreoptic communication line with a phase shift of odd bits

International Nuclear Information System (INIS)

Shapiro, Elena G

2009-01-01

The propagation of optical pulses through a fibreoptic communication line with a phase shift of odd bits is directly numerically simulated. It is shown that simple analytic expressions approximate well the error probability. The phase shift of odd bits in the initial sequence is statistically shown to decrease significantly the error probability in the communication line. (fibreoptic communication lines)

Microstructure and properties of 700 MPa grade HSLA steel during high temperature deformation

International Nuclear Information System (INIS)

Chen, Xizhang; Huang, Yuming; Lei, Yucheng

2015-01-01

Highlights: • Hot deformation behavior of 700 MPa HSLA steel above 1200 °C in was detailed studied. • Uniform and granular bainite is formed when the deformation amount is 40%. • Deformation resistance value under steady-equilibrium state is about 56 MPa. - Abstract: A high temperature deformation experiment was conducted on a high strength low alloy (HSLA) steel Q690 using Thermecmastor-Z thermal/physical simulator. During the experiment, the specimens were heated from room temperature to 1200 °C with the heating rate of 10 °C/s and 50 °C/s, respectively. The deformation temperature was 1200 °C and the deformation amounts were 0%, 10% and 40%, respectively. The microstructures, stress–strain diagram and hardness were obtained. The results revealed that the microstructure transformation of deformed austenite was quite different from that of the normal situation. With the increasing of deformation amount, more lath-shaped microstructure and less granulous microstructure were observed. The compressive deformation effectively prevented the precipitation of carbides. Larger deformation amount or lower heating rate was conducive to the atomic diffusion, which led to the microstructure uniformity and hardness decreasing. The maximum stress was 68.4 MPa and the steady stress was about 56 MPa

Alloy-dependent deformation behavior of highly ductile nanocrystalline AuCu thin films

International Nuclear Information System (INIS)

Lohmiller, Jochen; Spolenak, Ralph; Gruber, Patric A.

2014-01-01

Nanocrystalline thin films on compliant substrates become increasingly important for the development of flexible electronic devices. In this study, nanocrystalline AuCu thin films on polyimide substrate were tested in tension while using a synchrotron-based in situ testing technique. Analysis of X-ray diffraction profiles allowed identifying the underlying deformation mechanisms. Initially, elastic and microplastic deformation is observed, followed by dislocation-mediated shear band formation, and eventually macroscopic crack formation. Particularly the influence of alloy composition, heat-treatment, and test temperature were investigated. Generally, a highly ductile behavior is observed. However, high Cu concentrations, annealing, and/or large plastic strains lead to localized deformation and hence reduced ductility. On the other hand, enhanced test temperature allows for a delocalized deformation and extended ductility

Alloy-dependent deformation behavior of highly ductile nanocrystalline AuCu thin films

Energy Technology Data Exchange (ETDEWEB)

Lohmiller, Jochen [Karlsruhe Institute of Technology, Institute for Applied Materials, P.O. Box 3640, 76021 Karlsruhe (Germany); Laboratory for Nanometallurgy, Department of Materials, ETH Zurich, Wolfgang-Pauli-Str. 10, 8093 Zurich (Switzerland); Spolenak, Ralph [Laboratory for Nanometallurgy, Department of Materials, ETH Zurich, Wolfgang-Pauli-Str. 10, 8093 Zurich (Switzerland); Gruber, Patric A., E-mail: patric.gruber@kit.edu [Karlsruhe Institute of Technology, Institute for Applied Materials, P.O. Box 3640, 76021 Karlsruhe (Germany)

2014-02-10

Nanocrystalline thin films on compliant substrates become increasingly important for the development of flexible electronic devices. In this study, nanocrystalline AuCu thin films on polyimide substrate were tested in tension while using a synchrotron-based in situ testing technique. Analysis of X-ray diffraction profiles allowed identifying the underlying deformation mechanisms. Initially, elastic and microplastic deformation is observed, followed by dislocation-mediated shear band formation, and eventually macroscopic crack formation. Particularly the influence of alloy composition, heat-treatment, and test temperature were investigated. Generally, a highly ductile behavior is observed. However, high Cu concentrations, annealing, and/or large plastic strains lead to localized deformation and hence reduced ductility. On the other hand, enhanced test temperature allows for a delocalized deformation and extended ductility.

Nuclear moments and deformation changes in the lightest Pt isotopes measured by laser spectroscopy

CERN Document Server

Roussière, B; Crawford, J; Duong, H T; Genevey, J; Girod, M; Huber, G; Ibrahim, F; Krieg, M; Le Blanc, F; Lee, J K P; Obert, J; Oms, J; Peru, S; Pinard, J; Putaux, J C; Sauvage, J; Sebastian, V; Zemlyanoi, S G; Forkel-Wirth, Doris; Lettry, Jacques

1999-01-01

Laser spectroscopy measurements are performed with the lightest neutron-deficient platinum isotopes using the experimental setup COMPLIS installed at the ISOLDE-Booster facility. The hyperfine spectra of /sup 182-178/Pt and /sup 183m/Pt are recorded for the first time from the optical transition 5d/sup 9/6s/sup 3/D/sub 3/ to 5d/sup 9/6p/sup 3/P/sub 2/. The variation in the mean-square charge radius of these nuclei and the magnetic and quadrupole (for I>or=1) moments of the odd isotope nuclei are found. A large deformation change between the /sup 183g/Pt and /sup 183m/Pt nuclei, quite large inverted odd-even staggering of the charge radius around the neutron midshell N=104, and a nuclear deformation drop in the region A=179 are revealed. All the results are discussed in terms of nuclear shape variation and are compared with the results of Hartree-Fock- Bogoliubov calculations involving the Gogny force. Comparison of the deformation measured from /sup 183g, m/Pt to the odd-odd isotone /sup 184g, m/Au shows that...

Deformation behavior of large, high-pressure vessel flanges

International Nuclear Information System (INIS)

Spaas, H.A.C.M.; Latzko, D.G.H.

1975-01-01

The analysis of the deformation behavior of large high-pressure vessel flanges poses a much more difficult problem than for low-pressure flanges due to their particular geometry. For a particularly narrow flange geometry (typical of PWR flanges) a finite-element analysis (MARC-IBM-program, eight-node, isoparametric ring elements) was used to predict the behavior of the flange rings. The nonlinear elastic problem resulting from the local closing and/or opening of the partial gap between the gasket faces was solved by an incremental technique using gap elements. The resulting deformation behavior of the flange system has been compared to that obtained from an analysis using the refined rigid ring concept for both bolt-tightening and hydro-testing conditions. The elasto-plastic analysis was solved by the same finite element program system as mentioned above. The incremental steps describing the nonlinear material behavior are allowed to be larger than those for the gap-closure mechanism. Besides a comparison with the former elastic analyses an interpretation will be given of the local plasticity effects, which result in a shift in location of the gasket reaction. Experimental data on local gasket face deformation was obtained by a specially developed laser beam apparatus, with the leak detection channel of the flange serving as a beam hole. Additionally strain gauges were used on flanges and bolts, in combination with special sensing pins for the determination of relative flange rotations. Results obtained so far indicate that for high-pressure flanges of the narrow design investigated here the deformation behavior is best described by an elasto-plastic finite element analysis

Large-deformation and high-strength amorphous porous carbon nanospheres

Science.gov (United States)

Yang, Weizhu; Mao, Shimin; Yang, Jia; Shang, Tao; Song, Hongguang; Mabon, James; Swiech, Wacek; Vance, John R.; Yue, Zhufeng; Dillon, Shen J.; Xu, Hangxun; Xu, Baoxing

2016-04-01

Carbon is one of the most important materials extensively used in industry and our daily life. Crystalline carbon materials such as carbon nanotubes and graphene possess ultrahigh strength and toughness. In contrast, amorphous carbon is known to be very brittle and can sustain little compressive deformation. Inspired by biological shells and honeycomb-like cellular structures in nature, we introduce a class of hybrid structural designs and demonstrate that amorphous porous carbon nanospheres with a thin outer shell can simultaneously achieve high strength and sustain large deformation. The amorphous carbon nanospheres were synthesized via a low-cost, scalable and structure-controllable ultrasonic spray pyrolysis approach using energetic carbon precursors. In situ compression experiments on individual nanospheres show that the amorphous carbon nanospheres with an optimized structure can sustain beyond 50% compressive strain. Both experiments and finite element analyses reveal that the buckling deformation of the outer spherical shell dominates the improvement of strength while the collapse of inner nanoscale pores driven by twisting, rotation, buckling and bending of pore walls contributes to the large deformation.

Prevalence of self-reported finger deformations and occupational risk factors among professional cooks: a cross-sectional study

Directory of Open Access Journals (Sweden)

Tomita Shigeru

2011-05-01

Full Text Available Abstract Background Previous studies have pointed out that the school lunch workers in Japan are suffering from work-related disorders including finger deformations. The purpose of this study was to investigate the prevalence of self-reported finger deformations and the association with job-related risk factors. Methods A cross-sectional questionnaire study of 5,719 subjects (response rate: 81%, 982 men and 4,737 women was undertaken during September 2003 to February 2004. Results Finger deformations were found among 11.7% of the men and 35.6% of the women studied, with significant differences among sex, age and sex-age groups. For both men and women the pattern of finger deformations across the hand was similar for the right and the left hand. For women, the deformations were found in about 10% of the distal interphalangeal joints of all fingers. Based on multiple logistic regression analyses, the factors female sex, age, the number of cooked lunches per cook and cooking activities were independently associated with the prevalence of finger deformations. High prevalence odds ratios were found for those frequently carrying or using tools by hands such as delivering containers, distributing meals, preparing dishes, washing equipment, cutting and stirring foods. Conclusions Among the school lunch workers studied, women had a higher prevalence of finger deformations on all joints of both hands. Various cooking tasks were associated with the prevalence of finger deformations. The results suggest that improvements in working conditions are important for preventing work-related disorders such as finger deformations.

Direct measurement of erythrocyte deformability in diabetes mellitus with a transparent microchannel capillary model and high-speed video camera system.

Science.gov (United States)

Tsukada, K; Sekizuka, E; Oshio, C; Minamitani, H

2001-05-01

To measure erythrocyte deformability in vitro, we made transparent microchannels on a crystal substrate as a capillary model. We observed axisymmetrically deformed erythrocytes and defined a deformation index directly from individual flowing erythrocytes. By appropriate choice of channel width and erythrocyte velocity, we could observe erythrocytes deforming to a parachute-like shape similar to that occurring in capillaries. The flowing erythrocytes magnified 200-fold through microscopy were recorded with an image-intensified high-speed video camera system. The sensitivity of deformability measurement was confirmed by comparing the deformation index in healthy controls with erythrocytes whose membranes were hardened by glutaraldehyde. We confirmed that the crystal microchannel system is a valuable tool for erythrocyte deformability measurement. Microangiopathy is a characteristic complication of diabetes mellitus. A decrease in erythrocyte deformability may be part of the cause of this complication. In order to identify the difference in erythrocyte deformability between control and diabetic erythrocytes, we measured erythrocyte deformability using transparent crystal microchannels and a high-speed video camera system. The deformability of diabetic erythrocytes was indeed measurably lower than that of erythrocytes in healthy controls. This result suggests that impaired deformability in diabetic erythrocytes can cause altered viscosity and increase the shear stress on the microvessel wall. Copyright 2001 Academic Press.

Deformation properties of lead isotopes

International Nuclear Information System (INIS)

Tolokonnikov, S. V.; Borzov, I. N.; Lutostansky, Yu. S.; Saperstein, E. E.

2016-01-01

The deformation properties of a long lead isotopic chain up to the neutron drip line are analyzed on the basis of the energy density functional (EDF) in the FaNDF 0 Fayans form. The question of whether the ground state of neutron-deficient lead isotopes can have a stable deformation is studied in detail. The prediction of this deformation is contained in the results obtained on the basis of the HFB-17 and HFB-27 Skyrme EDF versions and reported on Internet. The present analysis reveals that this is at odds with experimental data on charge radii and magnetic moments of odd lead isotopes. The Fayans EDF version predicts a spherical ground state for all light lead isotopes, but some of them (for example, 180 Pb and 184 Pb) prove to be very soft—that is, close to the point of a phase transition to a deformed state. Also, the results obtained in our present study are compared with the predictions of some other Skyrme EDF versions, including SKM*, SLy4, SLy6, and UNE1. By and large, their predictions are closer to the results arising upon the application of the Fayans functional. For example, the SLy4 functional predicts, in just the same way as the FaNDF 0 functional, a spherical shape for all nuclei of this region. The remaining three Skyrme EDF versions lead to a deformation of some light lead isotopes, but their number is substantially smaller than that in the case of the HFB-17 and HFB-27 functionals. Moreover, the respective deformation energy is substantially lower, which gives grounds to hope for the restoration of a spherical shape upon going beyond the mean-field approximation, which we use here. Also, the deformation properties of neutron-rich lead isotopes are studied up to the neutron drip line. Here, the results obtained with the FaNDF 0 functional are compared with the predictions of the HFB-17, HFB-27, SKM*, and SLy4 Skyrme EDF versions. All of the EDF versions considered here predict the existence of a region where neutron-rich lead isotopes undergo

Calculation of β-ray spectra. Odd-odd nuclei

International Nuclear Information System (INIS)

Tachibana, Takahiro

1996-01-01

In order to study β-ray of atomic nucleus, it is natural to consider β-ray data fundamental and important. In a recent experiment, Rudstam measured β-ray spectra from short term nuclear fission product species in 1990. It is an important check point in theoretical study on β-ray to investigate if these experimental data can be reproduced by any theoretical calculation. As there are several spectrum studies of β-ray through decay heat for its various properties due to the general theory of the β-decay, little descriptions can be found. In even such studies, spectra under high excitation state of daughter species difficult to measure and apt to short experimental results were treated with combination spectra composed of experimental and calculated values such as substitution of a part of the general theory with calculated value. In this paper, the β spectra supposed by only the general theory was reported without using such data combination in order to confirm effectiveness of the theory. In particular, this report was described mainly on the results using recent modification of odd-odd nucleus species. (G.K.)

Calculation of {beta}-ray spectra. Odd-odd nuclei

Energy Technology Data Exchange (ETDEWEB)

Tachibana, Takahiro [Waseda Univ., Tokyo (Japan). Advanced Research Center for Science and Engineering

1996-05-01

In order to study {beta}-ray of atomic nucleus, it is natural to consider {beta}-ray data fundamental and important. In a recent experiment, Rudstam measured {beta}-ray spectra from short term nuclear fission product species in 1990. It is an important check point in theoretical study on {beta}-ray to investigate if these experimental data can be reproduced by any theoretical calculation. As there are several spectrum studies of {beta}-ray through decay heat for its various properties due to the general theory of the {beta}-decay, little descriptions can be found. In even such studies, spectra under high excitation state of daughter species difficult to measure and apt to short experimental results were treated with combination spectra composed of experimental and calculated values such as substitution of a part of the general theory with calculated value. In this paper, the {beta} spectra supposed by only the general theory was reported without using such data combination in order to confirm effectiveness of the theory. In particular, this report was described mainly on the results using recent modification of odd-odd nucleus species. (G.K.)

Remote Sensing of Deformation of a High Concrete-Faced Rockfill Dam Using InSAR: A Study of the Shuibuya Dam, China

Directory of Open Access Journals (Sweden)

Wei Zhou

2016-03-01

Full Text Available Settlement is one of the most important deformation characteristics of high concrete faced rockfill dams (CFRDs, >100 m. High CFRDs safety would pose a great threat to the security of people’s lives and property downstream if this kind of deformation were not to be measured correctly, as traditional monitoring approaches have limitations in terms of durability, coverage, and efficiency. It has become urgent to develop new monitoring techniques to complement or replace traditional monitoring approaches for monitoring the safety and operation status of high CFRDs. This study examines the Shuibuya Dam (up to 233.5 m in height in China, which is currently the highest CFRD in the world. We used space-borne Interferometric Synthetic Aperture Radar (InSAR time series to monitor the surface deformation of the Shuibuya Dam. Twenty-one ALOS PALSAR images that span the period from 28 February 2007 to 11 March 2011 were used to map the spatial and temporal deformation of the dam. A high correlation of 0.93 between the InSAR and the in-situ monitoring results confirmed the reliability of the InSAR method; the deformation history derived from InSAR is also consistent with the in-situ settlement monitoring system. In addition, the InSAR results allow continuous investigation of dam deformation over a wide area that includes the entire dam surface as well as the surrounding area, offering a clear picture continuously of the dam deformation.

Localized deformation via multiple twinning in a Mg–Gd–Y–Zr alloy processed by high-pressure torsion

International Nuclear Information System (INIS)

Tang, Lingling; Zhao, Yonghao; Liang, Ningning; Islamgaliev, R.K.; Valiev, R.Z.; Zhu, Y.T.

2016-01-01

Different with common grain refinement dominated by dislocation activities, grain subdivision induced by sequential activation of multiple twinning was observed in a Mg-Gd-Y-Zr magnesium alloy via high-pressure torsion. Deformation bands were evolved from large primary twin bands, which contained refined grains through localized multiple twinning. Nanometer-scaled amorphous bands were also observed within deformation bands in Mg alloys for the first time. These observations indicate that localized deformation via multiple twinning and the consequent formation of deformation bands are potential routes to grain refinement in rare earth-magnesium alloys.

Pairing correlations. II. Microscopic analysis of odd-even mass staggering in nuclei

International Nuclear Information System (INIS)

Duguet, T.; Bonche, P.; Heenen, P.-H.; Meyer, J.

2002-01-01

The odd-even mass staggering in nuclei is analyzed in the context of self-consistent mean-field calculations, for spherical as well as for deformed nuclei. For these nuclei, the respective merits of the energy differences Δ (3) and Δ (5) to extract both the pairing gap and the time-reversal symmetry breaking effect at the same time are extensively discussed. The usual mass formula Δ (3) is shown to contain additional mean-field contributions when realistic pairing is used in the calculation. A simple tool is proposed in order to remove the time-reversal symmetry breaking effects from Δ (5) . Extended comparisons with the odd-even mass staggering obtained in the zero-pairing limit (schematic model and self-consistent calculations) show the nonperturbative contribution of pairing correlations on this observable

Development of a Rotation Drickamer Apparatus for Deformation Studies Under High Pressure and High Temperature: Applications to magnesiowustite and Wadsleyite

Science.gov (United States)

Xu, Y.; Karato, S.

2002-12-01

Well-controlled high-pressure deformation experiments are critical for understanding the dynamics of Earth's interior. Most of the previous works on ultrahigh-pressure (P>10 GPa) deformation experiments have two limitations. (1) The mode of deformation is "stress-relaxation", in which stress changes with time in a given experiment, and (2) the magnitude of stress is limited (press combined with a rotation actuator involving an ac servo-motor. After the desired pressure and temperature are reached, torsional stress can be applied to a sample with a constant rotation rate. The advantage of this design is that the direction of shear deformation is normal to that of compression and therefore compression and deformation can be separated. A sample (typically ~1.8 mm diameter and ~0.2 mm thickness) is sandwiched between two zirconia plates and two heater plates made of TiC + diamond. Thin foils of W3%Re and W25%Re are inserted between two halves of samples which act as a thermocouple as well as strain markers. We have conducted a preliminary test on MgO at ~12 GPa and ~1470 K to the strain up to ~3. Deformation experiments on wadsleyite are underway to investigate the fabric development and rheology in this mineral.

Experimental deformation of a mafic rock - interplay between fracturing, reaction and viscous deformation

Science.gov (United States)

Marti, Sina; Stünitz, Holger; Heilbronner, Renée; Plümper, Oliver; Drury, Martyn

2016-04-01

Deformation experiments were performed on natural Maryland Diabase (˜ 55% Plg, 42% Px, 3% accessories, 0.18 wt.-% H2O added) in a Griggs-type deformation apparatus in order to explore the brittle-viscous transition and the interplay between deformation and mineral reactions. Shear experiments at strain rates of ˜ 2e-5 /s are performed, at T=600, 700 and 800°C and confining pressures Pc=1.0 and 1.5 GPa. Deformation localizes in all experiments. Below 700°C, the microstructure is dominated by brittle deformation with a foliation formed by cataclastic flow and high strain accommodated along 3-5 major ultracataclasite shear bands. At 700°C, the bulk of the material still exhibits abundant microfractures, however, deformation localizes into an anastomosing network of shear bands (SB) formed from a fine-grained (<< 1 μm) mixture of newly formed Plg and Amph. These reaction products occur almost exclusively along syn-kinematic structures such as fractures and SB. Experiments at 800°C show extensive mineral reactions, with the main reaction products Amph+Plg (+Zo). Deformation is localized in broad C' and C SB formed by a fine-grained (0.1 - 0.8 μm) mixture of Plg+Amph (+Zo). The onset of mineral reactions in the 700°C experiments shows that reaction kinetics and diffusional mass transport are fast enough to keep up with the short experimental timescales. While in the 700°C experiments brittle processes kinematically contribute to deformation, fracturing is largely absent at 800°C. Diffusive mass transfer dominates. The very small grain size within SB favours a grain size sensitive deformation mechanism. Due to the presence of water (and relatively high supported stresses), dissolution-precipitation creep is interpreted to be the dominant strain accommodating mechanism. From the change of Amph coronas around Px clasts with strain, we can determine that Amph is re-dissolved at high stress sites while growing in low stress sites, showing the ability of Amph to

Spin-dependent level density in interacting Boson-Fermion-Fermion model of the Odd-Odd Nucleus 196Au

International Nuclear Information System (INIS)

Kabashi, S.; Bekteshi, S.; Ahmetaj, S.; Shaqiri, Z.

2009-01-01

The level density of the odd-odd nucleus 196 Au is investigated in the interacting boson-fermion-fermion model (IBFFM) which accounts for collectivity and complex interaction between quasiparticle and collective modes.The IBFFM spin-dependent level densities show high-spin reduction with respect to Bethe formula.This can be well accounted for by a modified spin-dependent level density formula. (authors)

Cytocompatibility evaluation and surface characterization of TiNi deformed by high-pressure torsion

Energy Technology Data Exchange (ETDEWEB)

Awang Shri, Dayangku Noorfazidah, E-mail: AWANGSHRI.Dayangku@nims.go.jp [Graduate School of Pure and Applied Sciences, University of Tsukuba, Tsukuba, Ibaraki 305-8577 (Japan); Structural Materials Unit, National Institute for Materials Science, Tsukuba, Ibaraki 305-0047 (Japan); Tsuchiya, Koichi [Graduate School of Pure and Applied Sciences, University of Tsukuba, Tsukuba, Ibaraki 305-8577 (Japan); Structural Materials Unit, National Institute for Materials Science, Tsukuba, Ibaraki 305-0047 (Japan); Yamamoto, Akiko [Biomaterials Unit, International Center for Material Nanoarchitectonics (WPI-MANA), National Institute for Materials Science, Namiki 1-1, Tsukuba, Ibaraki 305-0044 (Japan)

2014-10-01

Effect of high-pressure torsion (HPT) deformation on biocompatibility and surface chemistry of TiNi was systematically investigated. Ti–50 mol% Ni was subjected to HPT straining for different numbers of turns, N = 0.25, 0.5, 1, 5 and 10 at a rotation speed of 1 rpm. X-ray photoelectron spectroscopy observations after 7 days of cell culture revealed the changes in the surface oxide composition, enrichment of Ti and detection of nitrogen derived from organic molecules in the culture medium. Plating efficiency of L929 cells was slightly increased by HPT deformation though no significant difference was observed. Albumin adsorption was higher in HPT-deformed samples, while vitronectin adsorption was peaked at N = 1. HPT deformation was also found to effectively suppress the Ni ion release from the TiNi samples into the cell culture medium even after the low degree of deformation at N = 0.25. - Highlights: • Nanostructured Ti–50 mol%Ni alloy was produced using high-pressure torsion. • HPT deformation improved L929 growth on TiNi samples. • Changes in surface chemistry were observed in HPT deformed samples. • Protein adsorption behavior was influenced by the surface chemistry. • Ni ion release was suppressed in HPT deformed samples.

Changes in erythrocytic deformability and plasma viscosity in neonatal ictericia.

Science.gov (United States)

Bonillo-Perales, A; Muñoz-Hoyos, A; Martínez-Morales, A; Molina-Carballo, A; Uberos-Fernández, J; Puertas-Prieto, A

1999-01-01

We studied 45 full-term newborns divided into 3 groups. Group 1: 17 newborns with bilirubin ictericia (bilirubin 11-20 mg/dL) and Group 3: 10 newborns with moderate hemolytic ictericia needing exchange transfusion. The following were studied: erythrocytic deformability, plasma viscosity, plasmatic osmolarity, seric bilirubin, bilirubin/albumin ratio, free fatty acids and corpuscular volume of the erythrocytes. In full-term newborns, the following are risk factors for increased erythrocytic rigidity: neonatal hemolytic illness (p = 0.004, odds ratio: 7.02), increases in total bilirubin (p = 0.02, odds ratio: 4.3) and increases in the bilirubin/albumin ratio (p = 0.025, odds ratio: 4.25). Furthermore, the most important risk factor for high plasma viscosity is also neonatal hemolytic illness (p = 0.01, odds ratio: 2.30). The role of total bilirubin is also important (p = 0.09, odds ratio: 2.10), while that of the bilirubin/albumin ratio (p = 0.012, NS) is less so. The greater the hemolysis, the greater the erythrocytic rigidity and plasma viscosity (p ictericia, hemolytic illness and increases in the bilirubin/albumin ratio are accompanied by rheological alterations that could affect cerebral microcirculation and cause a neurological deficit not exclusively related to the levels of bilirubin in plasma.

Tensile deformation behavior and deformation twinning of an equimolar CoCrFeMnNi high-entropy alloy

Energy Technology Data Exchange (ETDEWEB)

Joo, S.-H.; Kato, H. [Institute for Materials Research, Tohoku University, Sendai 980-8577 (Japan); Jang, M.J.; Moon, J. [Department of Materials Science and Engineering, Pohang University of Science and Technology, Pohang 37673 (Korea, Republic of); Tsai, C.W.; Yeh, J.W. [Department of Materials Science and Engineering, National Tsing Hua University, Hsinchu 30013, Taiwan (China); Kim, H.S., E-mail: hskim@postech.ac.kr [Department of Materials Science and Engineering, Pohang University of Science and Technology, Pohang 37673 (Korea, Republic of); Center for High Entropy Alloys, Pohang University of Science and Technology, Pohang 37673 (Korea, Republic of)

2017-03-24

The tensile deformation and strain hardening behaviors of an equimolar CoCrFeMnNi high-entropy alloy (HEA) were investigated and compared with low and medium entropy equiatomic alloys (LEA and MEA). The HEA had a lower yield strength than the MEA because the addition of Mn weakens solid solution hardening in the HEA. However, deformation twinning induced the multiple stage strain hardening behavior of the HEA and enhanced strength and elongation. Using tensile-interrupted electron backscatter diffraction analysis, geometrically necessary dislocations were observed as plume-shaped features in grain interior, and a considerable texture was characterized, which is typical of face centered cubic metals. Moreover, the relationship between favorably oriented grains and twinning in the HEA bore a clear resemblance to the same tendency in TWIP steels. The thickness of the twin bundles was less than 100 nm. A high density of stacking defects was found in the nanotwins. Nano twinning and stacking faults were found to contribute to the remarkable mechanical properties. Deformation induced twinning not only demonstrated the dynamic Hall-Petch effect but also changed dislocation cell substructures into microband structures.

Quasiparticle features and level statistics of odd-odd nucleus

International Nuclear Information System (INIS)

Cheng Nanpu; Zheng Renrong; Zhu Shunquan

2001-01-01

The energy levels of the odd-odd nucleus 84 Y are calculated by using the axially symmetric rotor plus quasiparticles model. The two standard statistical tests of Random-Matrix Theory such as the distribution function p(s) of the nearest-neighbor level spacings (NNS) and the spectral rigidity Δ 3 are used to explore the statistical properties of the energy levels. By analyzing the properties of p(s) and Δ 3 under various conditions, the authors find that the quasiparticle features mainly affect the statistical properties of the odd-odd nucleus 84 Y through the recoil term and the Coriolis force in this theoretical mode, and that the chaotic degree of the energy levels decreases with the decreasing of the Fermi energy and the energy-gap parameters. The effect of the recoil term is small while the Coriolis force plays a major role in the spectral structure of 84 Y

Effects of torsional deformation on the microstructures and mechanical properties of a CoCrFeNiMo0.15 high-entropy alloy

Science.gov (United States)

Wu, Wenqian; Guo, Lin; Liu, Bin; Ni, Song; Liu, Yong; Song, Min

2017-12-01

The effects of torsional deformation on the microstructures and mechanical properties of a CoCrFeNiMo0.15 high-entropy alloy have been investigated. The torsional deformation generates a gradient microstructure distribution due to the gradient torsional strain. Both dislocation activity and deformation twinning dominated the torsional deformation process. With increasing the torsional equivalent strain, the microstructural evolution can be described as follows: (1) formation of pile-up dislocations parallel to the trace of {1 1 1}-type slip planes; (2) formation of Taylor lattices; (3) formation of highly dense dislocation walls; (3) formation of microbands and deformation twins. The extremely high deformation strain (strained to fracture) results in the activation of wavy slip. The tensile strength is very sensitive to the torsional deformation, and increases significantly with increasing the torsional angle.

Anisotropic deformation of Zr–2.5Nb pressure tube material at high temperatures

Energy Technology Data Exchange (ETDEWEB)

Fong, R.W.L., E-mail: fongr@aecl.ca [Fuel and Fuel Channel Safety Branch, Atomic Energy of Canada Limited, Chalk River Nuclear Laboratories, Chalk River, Ontario (Canada)

2013-09-15

Zr–2.5Nb alloy is used for the pressure tubes in CANDU® reactor fuel channels. In reactor, the pressure tube normally operates at 300 °C and experiences a primary coolant fluid internal pressure of approximately 10 MPa. Manufacturing and processing procedures generate an anisotropic state in the pressure tube which makes the tube stronger in the hoop (transverse) direction than in the axial (longitudinal) direction. This anisotropy condition is present for temperatures less than 500 °C. During postulated accident conditions where the material temperature could reach 1000 °C, it might be assumed that the high temperature and subsequent phase change would reduce the inherent anisotropy, and thus affect the deformation behaviour (ballooning) of the pressure tube. From constant-load, rapid-temperature-ramp, uniaxial deformation tests, the deformation rate in the longitudinal direction of the tube behaves differently than the deformation rate in the transverse direction of the tube. This anisotropic mechanical behaviour appears to persist at temperatures up to 1000 °C. This paper presents the results of high-temperature deformation tests using longitudinal and transverse specimens taken from as-received Zr–2.5Nb pressure tubes. It is shown that the anisotropic deformation behaviour observed at high temperatures is largely due to the stable crystallographic texture of the α-Zr phase constituent in the material that was previously observed by neutron diffraction measurements during heating at temperatures up to 1050 °C. The deformation behaviour is also influenced by the phase transformation occurring at high temperatures during heating. The effects of texture and phase transformation on the anisotropic deformation of as-received Zr–2.5Nb pressure tube material are discussed in the context of the tube ballooning behaviour. Because of the high temperatures in postulated accident scenarios, any irradiation damage will be annealed from the pressure tube material

High-temperature deformation of B2 NiAl-base alloys

International Nuclear Information System (INIS)

Lee, I.G.; Ghosh, A.K.

1994-01-01

The high-temperature deformation behavior of three rapidly solidified and processed NiAl-base alloys--NiAl, NiAl containing 2 pct TiB 2 , and NiAl containing 4 pct HfC--have been studied and their microstructural and textural changes during deformation characterized. Compressions tests were conducted at 1,300 and 1,447 K at strain rates ranging from 10 -6 to 10 -2 s -1 . HfC-containing material showed dispersion strengthening as well as some degree of grain refinement over NiAl, while TiB 2 dispersoid-containing material showed grain refinement as well as secondary recrystallization and did not improve high-temperature strength. Hot-pack rolling was also performed to develop thin sheet materials (1.27-mm thick) and from these alloys. Without dispersoids, NiAl rolled easily at 1,223 K and showed low flow stress and good ductility during the hot-rolling operation. Rolling of dispersoid-containing alloys was difficult due to strain localization and edge-cracking effects, resulting partly from the high flow stress at the higher strain rate during the rolling operation. Sheet rolling initially produced a {111} texture, which eventually broke into multiple-texture components with severe deformation

High Strain Rate and Shock-Induced Deformation in Metals

Science.gov (United States)

Ravelo, Ramon

2012-02-01

Large-scale non-equilibrium molecular Dynamics (MD) simulations are now commonly used to study material deformation at high strain rates (10^9-10^12 s-1). They can provide detailed information-- such as defect morphology, dislocation densities, and temperature and stress profiles, unavailable or hard to measure experimentally. Computational studies of shock-induced plasticity and melting in fcc and bcc single, mono-crystal metals, exhibit generic characteristics: high elastic limits, large directional anisotropies in the yield stress and pre-melting much below the equilibrium melt temperature for shock wave propagation along specific crystallographic directions. These generic features in the response of single crystals subjected to high strain rates of deformation can be explained from the changes in the energy landscape of the uniaxially compressed crystal lattice. For time scales relevant to dynamic shock loading, the directional-dependence of the yield strength in single crystals is shown to be due to the onset of instabilities in elastic-wave propagation velocities. The elastic-plastic transition threshold can accurately be predicted by a wave-propagation stability analysis. These strain-induced instabilities create incipient defect structures, which can be quite different from the ones, which characterize the long-time, asymptotic state of the compressed solid. With increase compression and strain rate, plastic deformation via extended defects gives way to amorphization associated with the loss in shear rigidity along specific deformation paths. The hot amorphous or (super-cooled liquid) metal re-crystallizes at rates, which depend on the temperature difference between the amorphous solid and the equilibrium melt line. This plastic-amorphous transition threshold can be computed from shear-waves stability analyses. Examples from selected fcc and bcc metals will be presented employing semi-empirical potentials of the embedded atom method (EAM) type as well as

Deformation properties of lead isotopes

Energy Technology Data Exchange (ETDEWEB)

Tolokonnikov, S. V.; Borzov, I. N.; Lutostansky, Yu. S.; Saperstein, E. E., E-mail: saper43-7@mail.ru [National Research Center Kurchatov Institute (Russian Federation)

2016-01-15

The deformation properties of a long lead isotopic chain up to the neutron drip line are analyzed on the basis of the energy density functional (EDF) in the FaNDF{sup 0} Fayans form. The question of whether the ground state of neutron-deficient lead isotopes can have a stable deformation is studied in detail. The prediction of this deformation is contained in the results obtained on the basis of the HFB-17 and HFB-27 Skyrme EDF versions and reported on Internet. The present analysis reveals that this is at odds with experimental data on charge radii and magnetic moments of odd lead isotopes. The Fayans EDF version predicts a spherical ground state for all light lead isotopes, but some of them (for example, {sup 180}Pb and {sup 184}Pb) prove to be very soft—that is, close to the point of a phase transition to a deformed state. Also, the results obtained in our present study are compared with the predictions of some other Skyrme EDF versions, including SKM*, SLy4, SLy6, and UNE1. By and large, their predictions are closer to the results arising upon the application of the Fayans functional. For example, the SLy4 functional predicts, in just the same way as the FaNDF{sup 0} functional, a spherical shape for all nuclei of this region. The remaining three Skyrme EDF versions lead to a deformation of some light lead isotopes, but their number is substantially smaller than that in the case of the HFB-17 and HFB-27 functionals. Moreover, the respective deformation energy is substantially lower, which gives grounds to hope for the restoration of a spherical shape upon going beyond the mean-field approximation, which we use here. Also, the deformation properties of neutron-rich lead isotopes are studied up to the neutron drip line. Here, the results obtained with the FaNDF{sup 0} functional are compared with the predictions of the HFB-17, HFB-27, SKM*, and SLy4 Skyrme EDF versions. All of the EDF versions considered here predict the existence of a region where neutron

A METHOD FOR THE EXTRACTION OF LONG-TERM DEFORMATION CHARACTERISTICS OF LONG-SPAN HIGH-SPEED RAILWAY BRIDGES USING HIGH-RESOLUTION SAR IMAGES

OpenAIRE

Jia, H. G.; Liu, L. Y.

2016-01-01

Natural causes and high-speed train load will result in the structural deformation of long-span bridges, which greatly influence the safety operation of high-speed railway. Hence it is necessary to conduct the deformation monitoring and regular status assessment for long-span bridges. However for some traditional surveying technique, e.g. control-point-based surveying techniques, a lot of human and material resources are needed to perform the long-term monitoring for the whole bridge. In this...

Theoretical study of band structure of odd-mass {sup 115,117}I isotopes

Energy Technology Data Exchange (ETDEWEB)

Singh, Dhanvir, E-mail: singh1472phy@gmail.com; Kumar, Amit, E-mail: akbcw2@gmail.com; Sharma, Chetan, E-mail: chetan24101985@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-184101 (India); Bharti, Arun, E-mail: arunbharti-2003@yahoo.co.in [Professor, Department of Physics and Electronics, University of Jammu, Jammu-180006 (India)

2016-05-06

By using the microscopic approach of Projected Shell Model (PSM), negative-parity band structures of odd mass neutron-rich {sup 115,117}I nuclei have been studied with the deformed single-particle states generated by the standard Nilsson potential. For these isotopes, the band structures have been analyzed in terms of quasi-particles configurations. The phenomenon of back bending in moment of inertia is also studied in the present work.

Intruder bands in odd-A {sup 109-115}Sb

Energy Technology Data Exchange (ETDEWEB)

Janzen, V P [Atomic Energy of Canada Ltd., Chalk River, ON (Canada). Chalk River Nuclear Labs.; [McMaster Univ., Hamilton, ON (Canada). Dept. of Physics; Andrews, H R; Galindo-Uribarri, A; Radford, D C; Ward, D [Atomic Energy of Canada Ltd., Chalk River, ON (Canada). Chalk River Nuclear Labs.; Omar, A; Mullins, S; Persson, L; Prevost, D; Rodriguez, J; Sawicki, M; Unrau, P; Waddington, J C [McMaster Univ., Hamilton, ON (Canada). Dept. of Physics; Drake, T E; Zwartz, G [Toronto Univ., ON (Canada). Dept. of Physics; Fossan, D B; Lafosse, D R; Hughes, J R; Schnare, H; Timmers, H; Vaska, P [State Univ. of New York, Stony Brook, NY (United States). Dept. of Physics; Haas, B [Atomic Energy of Canada Ltd., Chalk River, ON (Canada). Chalk River Nuclear Labs.; [Strasbourg-1 Univ., 67 (France). Centre de Recherches Nucleaires; Paul, E S; Wilson, J [Liverpool Univ. (United Kingdom). Oliver Lodge Lab.; Pilotte, S [Ottawa Univ., ON (Canada). Dept. of Physics; Wadsworth, R [York Univ. (United Kingdom). Dept. of Physics; Wyss, R [Joint Inst. for Heavy Ion Research, Oak Ridge, TN (United States)

1992-08-01

The existence of rotational structures in nuclei bordering on the spherical Z= 50 closed shell has been known for some time. Nevertheless, our understanding of collective effects in this region is remarkably incomplete; for example, before this work little high-spin data existed and there were no lifetime measurements to confirm the collectivity associated with the rotational bands observed in Sb (Z = 51) and Sn (Z = 50) nuclei. Furthermore, the role of the h{sub 11/2} orbital was virtually unknown, although it has the highest angular momentum of the orbitals in this mass region and therefore is expected to have the most influence on the properties of high-spin states. In the A {approx} 130 and A {approx} 180 mass regions, where highly deformed intruder bands have been observed, it is the neutron i{sub 13/2} orbitals, respectively, which are preferentially lowered in energy by a combination of large deformation and fast rotation In lighter nuclei the h{sub 11/2} orbital is expected to appear as an intruder configuration. (author). 11 refs., 1 tab., 4 figs.

A novel deformation mechanism for superplastic deformation

Energy Technology Data Exchange (ETDEWEB)

Muto, H.; Sakai, M. (Toyohashi Univ. of Technology (Japan). Dept. of Materials Science)

1999-01-01

Uniaxial compressive creep tests with strain value up to -0.1 for a [beta]-spodumene glass ceramic are conducted at 1060 C. From the observation of microstructural changes between before and after the creep deformations, it is shown that the grain-boundary sliding takes place via cooperative movement of groups of grains rather than individual grains under the large-scale-deformation. The deformation process and the surface technique used in this work are not only applicable to explain the deformation and flow of two-phase ceramics but also the superplastic deformation. (orig.) 12 refs.

Conflicting Coupling of Unpaired Nucleons and the Structure of Collective Bands in Odd-Odd Nuclei

International Nuclear Information System (INIS)

Levon, A.I.; Pasternak, A.A.

2011-01-01

The conflicting coupling of unpaired nucleons in odd-odd nuclei is discussed. A very simple explanation is suggested for the damping of the energy spacing of the lowest levels in the rotational bands in odd-odd nuclei with the 'conflicting' coupling of an odd proton and an odd neutron comparative to those of the bands based on the state of a strongly coupled particle in the neighboring odd nucleus entering the 'conflicting' configuration.

High Rate Plastic Deformation and Failure of Tungsten-Sintered Metals

National Research Council Canada - National Science Library

Bjerke, Todd

2004-01-01

The competition between plastic deformation and brittle fracture during high rate loading of a tungsten-sintered metal is examined through impact experiments, post-experiment microscopy, and numerical simulation...

Odd Structures Are Odd

Czech Academy of Sciences Publication Activity Database

Markl, Martin

2017-01-01

Roč. 27, č. 2 (2017), s. 1567-1580 ISSN 0188-7009 Institutional support: RVO:67985840 Keywords : graded vector space * monoidal structure * Odd endomorphism operad Subject RIV: BA - General Mathematics OBOR OECD: Pure mathematics Impact factor: 0.643, year: 2016 http://link.springer.com/article/10.1007%2Fs00006-016-0720-8

Monitoring the Deformation of High-Rise Buildings in Shanghai Luijiazui Zone by Tomo-Psinsar

Science.gov (United States)

Zhou, L. F.; Ma, P. F.; Xia, Y.; Xie, C. H.

2018-05-01

In this study, we utilize a Tomography-based Persistent Scatterers Interferometry (Tomo-PSInSAR) approach for monitoring the deformation performances of high-rise buildings, i.e. SWFC and Jin Mao Tower, in Shanghai Lujiazui Zone. For the purpose of this study, we use 31 Stripmap acquisitions from TerraSAR-X missions, spanning from December 2009 to February 2013. Considering thermal expansion, creep and shrinkage are two long-term movements that occur in high-rise buildings with concrete structures, we use an extended 4-D SAR phase model, and three parameters (height, deformation velocity, and thermal amplitude) are estimated simultaneously. Moreover, we apply a two-tier network strategy to detect single and double PSs with no need for preliminary removal of the atmospheric phase screen (APS) in the study area, avoiding possible error caused by the uncertainty in spatiotemporal filtering. Thermal expansion is illustrated in the thermal amplitude map, and deformation due to creep and shrinkage is revealed in the linear deformation velocity map. The thermal amplitude map demonstrates that the derived thermal amplitude of the two high-rise buildings both dilate and contract periodically, which is highly related to the building height due to the upward accumulative effect of thermal expansion. The linear deformation velocity map reveals that SWFC is subject to deformation during the new built period due to creep and shrinkage, which is height-dependent movements in the linear velocity map. It is worth mention that creep and shrinkage induces movements that increase with the increasing height in the downward direction. In addition, the deformation rates caused by creep and shrinkage are largest at the beginning and gradually decrease, and at last achieve a steady state as time goes infinity. On the contrary, the linear deformation velocity map shows that Jin Mao Tower is almost stable, and the reason is that it is an old built building, which is not influenced by creep

MONITORING THE DEFORMATION OF HIGH-RISE BUILDINGS IN SHANGHAI LUIJIAZUI ZONE BY TOMO-PSINSAR

Directory of Open Access Journals (Sweden)

L. F. Zhou

2018-05-01

Full Text Available In this study, we utilize a Tomography-based Persistent Scatterers Interferometry (Tomo-PSInSAR approach for monitoring the deformation performances of high-rise buildings, i.e. SWFC and Jin Mao Tower, in Shanghai Lujiazui Zone. For the purpose of this study, we use 31 Stripmap acquisitions from TerraSAR-X missions, spanning from December 2009 to February 2013. Considering thermal expansion, creep and shrinkage are two long-term movements that occur in high-rise buildings with concrete structures, we use an extended 4-D SAR phase model, and three parameters (height, deformation velocity, and thermal amplitude are estimated simultaneously. Moreover, we apply a two-tier network strategy to detect single and double PSs with no need for preliminary removal of the atmospheric phase screen (APS in the study area, avoiding possible error caused by the uncertainty in spatiotemporal filtering. Thermal expansion is illustrated in the thermal amplitude map, and deformation due to creep and shrinkage is revealed in the linear deformation velocity map. The thermal amplitude map demonstrates that the derived thermal amplitude of the two high-rise buildings both dilate and contract periodically, which is highly related to the building height due to the upward accumulative effect of thermal expansion. The linear deformation velocity map reveals that SWFC is subject to deformation during the new built period due to creep and shrinkage, which is height-dependent movements in the linear velocity map. It is worth mention that creep and shrinkage induces movements that increase with the increasing height in the downward direction. In addition, the deformation rates caused by creep and shrinkage are largest at the beginning and gradually decrease, and at last achieve a steady state as time goes infinity. On the contrary, the linear deformation velocity map shows that Jin Mao Tower is almost stable, and the reason is that it is an old built building, which is not

Magneto-induced large deformation and high-damping performance of a magnetorheological plastomer

International Nuclear Information System (INIS)

Liu, Taixiang; Gong, Xinglong; Xu, Yangguang; Pang, Haoming; Xuan, Shouhu

2014-01-01

A magnetorheological plastomer (MRP) is a new kind of soft magneto-sensitive polymeric composite. This work reports on the large magneto-deforming effect and high magneto-damping performance of MRPs under a quasi-statical shearing condition. We demonstrate that an MRP possesses a magnetically sensitive malleability, and its magneto-mechanical behavior can be analytically described by the magneto-enhanced Bingham fluid-like model. The magneto-induced axial stress, which drives the deformation of the MRP with 70 wt % carbonyl iron powder, can be tuned in a large range from nearly 0.0 kPa to 55.4 kPa by an external 662.6 kA m −1 magnetic field. The damping performance of an MRP has a significant correlation with the magnetic strength, shear rate, carbonyl iron content and shear strain amplitude. For an MRP with 60 wt % carbonyl iron powder, the relative magneto-enhanced damping effect can reach as high as 716.2% under a quasi-statically shearing condition. Furthermore, the related physical mechanism is proposed, and we reveal that the magneto-induced, particle-assembled microstructure directs the magneto-mechanical behavior of the MRP. (paper)

Interface bonding of SA508-3 steel under deformation and high temperature diffusion

Science.gov (United States)

Xu, Bin; Shao, Chunjuan; Sun, Mingyue

2018-05-01

There are mainly two parameters affecting high temperature interface bonding: deformation and diffusion. To study these two parameters, interface bonding of SA508-3 bainitic steel at 1100°C are simulated by gleeble3500 thermal simulator. The results show that interface of SA508-3 steel can be bonded under deformation and high temperature. For a specimen pressed at 1100°C without further high temperature diffusion, a reduction ratio of 30% can make the interface begun to bond, but the interface is still part of the grain boundary and small grains exist near the interface. When reduction ratio reaches 50%, the interface can be completely bonded and the microstructure near the interface is the same as that of the base material. When deformation is small, long time diffusion can also help the interface bonding. The results show that when the diffusion time is long enough, the interface under small deformation can also be bonded. For a specimen holding for 24h at 1100°C, only 13% reduction ratio is enough for interface bonding.

Electric anisotropy in high density polyethylene + carbon black composites induced by mechanical deformation

Energy Technology Data Exchange (ETDEWEB)

Vigueras-Santiago, E; Hernandez-Lopez, S; Camacho-Lopez, M A; Lara-Sanjuan, O, E-mail: eviguerass@uaemex.m [Laboratorio de Investigacion y Desarrollo de Materiales Avanzados (LIDMA), Facultad de Quimica, UAEM. Paseo Colon esq. con Paseo Tollocan, s/n. C.P. 50000, Toluca (Mexico)

2009-05-01

High density polyethylene + carbon black composites with electrical anisotropy was studied. Electrical anisotropy was induced by uniaxial mechanical deformation and injection moulding. We show that anisotropy depends on the carbon black concentration and percentage deformation. Resistivity had the highest anisotropy resistivity around the percolation threshold. Perpendicular resistivity showed two magnitude orders higher than parallel resistivity for injected samples, whereas resistivity showed an inverse behaviour for 100% tensile samples. Both directions were set respect to the deformation axe. Anisotropy could be explained in terms of the molecular deformation (alignment) of the polymer chains as a response of the deformation process originating a redistribution of the carbon black particles in both directions. Alignment of the polymer chains was evidenced by polarized Raman spectroscopy.

Extension of an anisotropic creep model to general high temperature deformation of a single crystal superalloy

International Nuclear Information System (INIS)

Pan, L.M.; Ghosh, R.N.; McLean, M.

1993-01-01

A physics based model has been developed that accounts for the principal features of anisotropic creep deformation of single crystal superalloys. The present paper extends this model to simulate other types of high temperature deformation under strain controlled test conditions, such as stress relaxation and tension tests at constant strain rate in single crystals subject to axial loading along an arbitrary crystal direction. The approach is applied to the SRR99 single crystal superalloy where a model parameter database is available, determined via analysis of a database of constant stress creep curves. A software package has been generated to simulate the deformation behaviour under complex stress-strain conditions taking into account anisotropic elasticity. (orig.)

Creep of crystals: High-temperature deformation processes in metals, ceramics and minerals

Science.gov (United States)

Poirier, J. P.

An introductory text describing high-temperature deformation processes in metals, ceramics, and minerals is presented. Among the specific topics discussed are: the mechanical aspects of crystal deformation; lattice defects; and phenomenological and thermodynamical analysis of quasi-steady-state creep. Consideration is also given to: dislocation creep models; the effect of hydrostatic pressure on deformation; creep polygonization; and dynamic recrystallization. The status of experimental techniques for the study of transformation plasticity in crystals is also discussed.

External Validation of the Adult Spinal Deformity (ASD) Frailty Index (ASD-FI) in the Scoli-RISK-1 Patient Database.

Science.gov (United States)

Miller, Emily K; Lenke, Lawrence G; Neuman, Brian J; Sciubba, Daniel M; Kebaish, Khaled M; Smith, Justin S; Qiu, Yong; Dahl, Benny T; Pellisé, Ferran; Matsuyama, Yukihiro; Carreon, Leah Y; Fehlings, Michael G; Cheung, Kenneth M; Lewis, Stephen; Dekutoski, Mark B; Schwab, Frank J; Boachie-Adjei, Oheneba; Mehdian, Hossein; Bess, Shay; Shaffrey, Christopher I; Ames, Christopher P

2018-05-14

Analysis of a prospective multicenter database. To assess the ability of the recently created Adult Spinal Deformity (ASD) Frailty Index (ASD-FI) to predict odds of major complications and length of hospital stay for patients who had more severe preoperative deformity and underwent more invasive ASD surgery compared with patients in the database used to create the index. Accurate preoperative estimates of risk are necessary given the high complication rates currently associated with ASD surgery. Patients were enrolled by participating institutions in Europe, Asia, and North America from 2009 to 2011. ASD-FI scores were used to classify 267 patients as not frail (NF) (0.5). Multivariable logistic regression, adjusted for preoperative and surgical covariates such as operative time and blood loss, was performed to determine the relationship between ASD-FI category and incidence of major complications, overall incidence of complications, and length of hospital stay. The mean ASD-FI score was 0.3 (range, 0-0.7). We categorized 105 patients as NF, 103 as frail, and 59 as SF. The adjusted odds of developing a major complication were higher for SF patients (odds ratio = 4.4; 95% CI 2.0, 9.9) compared with NF patients. After adjusting for covariates, length of hospital stay for SF patients increased by 19% (95% CI 1.4%, 39%) compared with NF patients. The odds of developing a major complication or having increased length of stay were similar between frail and NF patients. Greater patient frailty, as measured by the ASD-FI, is associated with a longer hospital stay and greater risk of major complications among patients who have severe preoperative deformity and undergo invasive surgical procedures. 2.

'Static' octupole deformation at high spin

International Nuclear Information System (INIS)

Nazarewicz, W.

1985-01-01

Rotational bands characterized by spin states of alternating parity p=(-1) I connected by enhanced E1 transitions have recently been observed in several nuclei from the Ra-Th region. They can be interpreted by means of a reflection asymmetric mean field theory. The interplay between octupole deformation and rotation is briefly discussed. For nuclei with ground state octupole deformation a transition to a reflection symmetric shape is expected around I=22. (orig.)

A GPU based high-resolution multilevel biomechanical head and neck model for validating deformable image registration

Energy Technology Data Exchange (ETDEWEB)

Neylon, J., E-mail: jneylon@mednet.ucla.edu; Qi, X.; Sheng, K.; Low, D. A.; Kupelian, P.; Santhanam, A. [Department of Radiation Oncology, University of California Los Angeles, 200 Medical Plaza, #B265, Los Angeles, California 90095 (United States); Staton, R.; Pukala, J.; Manon, R. [Department of Radiation Oncology, M.D. Anderson Cancer Center, Orlando, 1440 South Orange Avenue, Orlando, Florida 32808 (United States)

2015-01-15

Purpose: Validating the usage of deformable image registration (DIR) for daily patient positioning is critical for adaptive radiotherapy (RT) applications pertaining to head and neck (HN) radiotherapy. The authors present a methodology for generating biomechanically realistic ground-truth data for validating DIR algorithms for HN anatomy by (a) developing a high-resolution deformable biomechanical HN model from a planning CT, (b) simulating deformations for a range of interfraction posture changes and physiological regression, and (c) generating subsequent CT images representing the deformed anatomy. Methods: The biomechanical model was developed using HN kVCT datasets and the corresponding structure contours. The voxels inside a given 3D contour boundary were clustered using a graphics processing unit (GPU) based algorithm that accounted for inconsistencies and gaps in the boundary to form a volumetric structure. While the bony anatomy was modeled as rigid body, the muscle and soft tissue structures were modeled as mass–spring-damper models with elastic material properties that corresponded to the underlying contoured anatomies. Within a given muscle structure, the voxels were classified using a uniform grid and a normalized mass was assigned to each voxel based on its Hounsfield number. The soft tissue deformation for a given skeletal actuation was performed using an implicit Euler integration with each iteration split into two substeps: one for the muscle structures and the other for the remaining soft tissues. Posture changes were simulated by articulating the skeletal structure and enabling the soft structures to deform accordingly. Physiological changes representing tumor regression were simulated by reducing the target volume and enabling the surrounding soft structures to deform accordingly. Finally, the authors also discuss a new approach to generate kVCT images representing the deformed anatomy that accounts for gaps and antialiasing artifacts that may

A GPU based high-resolution multilevel biomechanical head and neck model for validating deformable image registration

International Nuclear Information System (INIS)

Neylon, J.; Qi, X.; Sheng, K.; Low, D. A.; Kupelian, P.; Santhanam, A.; Staton, R.; Pukala, J.; Manon, R.

2015-01-01

Purpose: Validating the usage of deformable image registration (DIR) for daily patient positioning is critical for adaptive radiotherapy (RT) applications pertaining to head and neck (HN) radiotherapy. The authors present a methodology for generating biomechanically realistic ground-truth data for validating DIR algorithms for HN anatomy by (a) developing a high-resolution deformable biomechanical HN model from a planning CT, (b) simulating deformations for a range of interfraction posture changes and physiological regression, and (c) generating subsequent CT images representing the deformed anatomy. Methods: The biomechanical model was developed using HN kVCT datasets and the corresponding structure contours. The voxels inside a given 3D contour boundary were clustered using a graphics processing unit (GPU) based algorithm that accounted for inconsistencies and gaps in the boundary to form a volumetric structure. While the bony anatomy was modeled as rigid body, the muscle and soft tissue structures were modeled as mass–spring-damper models with elastic material properties that corresponded to the underlying contoured anatomies. Within a given muscle structure, the voxels were classified using a uniform grid and a normalized mass was assigned to each voxel based on its Hounsfield number. The soft tissue deformation for a given skeletal actuation was performed using an implicit Euler integration with each iteration split into two substeps: one for the muscle structures and the other for the remaining soft tissues. Posture changes were simulated by articulating the skeletal structure and enabling the soft structures to deform accordingly. Physiological changes representing tumor regression were simulated by reducing the target volume and enabling the surrounding soft structures to deform accordingly. Finally, the authors also discuss a new approach to generate kVCT images representing the deformed anatomy that accounts for gaps and antialiasing artifacts that may

Particle-number conservation in odd mass proton-rich nuclei in the isovector pairing case

International Nuclear Information System (INIS)

Fellah, M.; Allal, N.H.; Oudih, M.R.

2015-01-01

An expression of a wave function which describes odd–even systems in the isovector pairing case is proposed within the BCS approach. It is shown that it correctly generalizes the one used in the pairing between like-particles case. It is then projected on the good proton and neutron numbers using the Sharp-BCS (SBCS) method. The expressions of the expectation values of the particle-number operator and its square, as well as the energy, are deduced in both approaches. The formalism is applied to study the isovector pairing effect and the number projection one on the ground state energy of odd mass N ≈ Z nuclei using the single-particle energies of a deformed Woods–Saxon mean-field. It is shown that both effects on energy do not exceed 2%, however, the absolute deviations may reach several MeV. Moreover, the np pairing effect rapidly diminishes as a function of (N - Z). The deformation effect is also studied. It is shown that the np pairing effect, either before or after the projection, as well as the projection effect, when including or not the isovector pairing, depends upon the deformation. However, it seems that the predicted ground state deformation will remain the same in the four approaches. (author)

Analytical Modeling of the High Strain Rate Deformation of Polymer Matrix Composites

Science.gov (United States)

Goldberg, Robert K.; Roberts, Gary D.; Gilat, Amos

2003-01-01

The results presented here are part of an ongoing research program to develop strain rate dependent deformation and failure models for the analysis of polymer matrix composites subject to high strain rate impact loads. State variable constitutive equations originally developed for metals have been modified in order to model the nonlinear, strain rate dependent deformation of polymeric matrix materials. To account for the effects of hydrostatic stresses, which are significant in polymers, the classical 5 plasticity theory definitions of effective stress and effective plastic strain are modified by applying variations of the Drucker-Prager yield criterion. To verify the revised formulation, the shear and tensile deformation of a representative toughened epoxy is analyzed across a wide range of strain rates (from quasi-static to high strain rates) and the results are compared to experimentally obtained values. For the analyzed polymers, both the tensile and shear stress-strain curves computed using the analytical model correlate well with values obtained through experimental tests. The polymer constitutive equations are implemented within a strength of materials based micromechanics method to predict the nonlinear, strain rate dependent deformation of polymer matrix composites. In the micromechanics, the unit cell is divided up into a number of independently analyzed slices, and laminate theory is then applied to obtain the effective deformation of the unit cell. The composite mechanics are verified by analyzing the deformation of a representative polymer matrix composite (composed using the representative polymer analyzed for the correlation of the polymer constitutive equations) for several fiber orientation angles across a variety of strain rates. The computed values compare favorably to experimentally obtained results.

High spin states and isomeric decays in doubly-odd 208Fr

International Nuclear Information System (INIS)

Kanjilal, D.; Bhattacharya, S.; Goswami, A.; Kshetri, R.; Raut, R.; Saha, S.; Bhowmik, R.K.; Gehlot, J.; Muralithar, S.; Singh, R.P.; Jnaneswari, G.; Mukherjee, G.; Mukherjee, B.

2010-01-01

Neutron deficient isotopes of francium (Z=87, N∼121-123) as excited nuclei were produced in the fusion-evaporation reaction: 197 Au( 16 O, xn) 213-x Fr at 100 MeV. The γ rays from the residues were observed through the high sensitivity Germanium Clover detector array INGA. The decay of the high spin states and the isomeric states of the doubly-odd 208 Fr nuclei, identified from the known sequence of ground state transitions, were observed. The half-lives of the E γ =194(2) keV isomeric transition, known from earlier observations, was measured to be T 1/2 =233(18) ns. A second isomeric transition at E γ =383(2) keV and T 1/2 =33(7) ns was also found. The measured half-lives were compared with the corresponding single particle estimates, based on the level scheme obtained from the experiment.

High resolution deformation measurements at active volcanoes: a new remote sensing technology

Science.gov (United States)

Hort, M. K.; Scharff, L.; Gerst, A.; Meier, K.; Falk, S.; Peters, G.; Ripepe, M.

2013-12-01

It is known from observations at different volcanoes using ULP seismic observations that the volcanic edifice deforms slightly prior to an eruption. It can be expected that immediately prior to an eruption the largest deformation should occur in the vicinity of the vent. However, placing instruments at the vent is impossible as they will be destroyed during an eruption. Here we present new, high temporal resolution (up to 300Hz) deformation measurement that utilizes the phase information of a frequency modulated Doppler radar system. We decompose the Doppler signal into two parts, one part which allows us to measure speeds significantly above 0.5m/s (i.e. the movement of volcanic ash and clasts). The other part utilizes the slow phase changes of the signal reflected from non-moving objects, i.e. the volcanic edifice. This signal is used to measure very slow and longer term deformations, which are the main subject of this study. The method has been tested measuring the displacement of high rise buildings during strong winds. It can be shown that displacements down to 50 μm can be resolved without a problem. We apply this method to different data sets collected at Stromboli volcano, Italy, as well as Santiaguito volcano, Guatemala. At Stromboli we observed the NE crater once in 2008 and once in 2011. During both campaigns we observe on average a displacement between 1 and 5mm before different eruptions. This displacement can be interpreted as a widening of the conduit prior to an eruption. In a couple of cases even an oscillatory movement is observed with frequencies of about 0.5Hz. Finite element modeling of the rise of a pressurized slug indicates that deformations at the crater rim on the order of a 1mm or less are certainly reasonable. In the case of Santiaguito volcano prior to an eruption we observe a pre eruptive displacement 5-15mm and after the end of an eruption a displacement of up to 1m before the next eruption occurs. This can be interpreted as in

High incidence of deformity in aquatic turtles in the John Heinz National Wildlife Refuge

Energy Technology Data Exchange (ETDEWEB)

Bell, Barbara [Department of Bioscience and Biotechnology, Drexel University, 3141 Chestnut Street, Philadelphia, PA 19104 (United States); Spotila, James R [Department of Bioscience and Biotechnology, Drexel University, 3141 Chestnut Street, Philadelphia, PA 19104 (United States); Congdon, Justin [Savannah River Ecology Laboratory, University of Georgia, Drawer E., Aiken, SC (United States)

2006-08-15

The John Heinz National Wildlife Refuge is subject to pollution from multiple sources. We studied development of snapping turtle (Chelydra serpentina) and painted turtle (Chrysemys picta) embryos from the refuge from 2000 through 2003. Mean annual deformity rate of pooled painted turtle clutches over four years ranged from 45 to 71%, while that of snapping turtle clutches ranged from 13 to 19%. Lethal deformities were more common than minor or moderate deformities in embryos of both species. Adult painted turtles had a higher deformity rate than adult snapping turtles. Snapping turtles at JHNWR had high levels of PAH contamination in their fat. This suggests that PAHs are involved in the high level of deformities. Other contaminants may also play a role. Although the refuge offers many advantages to resident turtle populations, pollution appears to place a developmental burden on the life history of these turtles. - This paper presents findings on the prevalence of developmental abnormalities in turtles at a national wildlife refuge that have direct relevance to studies on the effects of contamination on development and morphology of vertebrates.

High incidence of deformity in aquatic turtles in the John Heinz National Wildlife Refuge

International Nuclear Information System (INIS)

Bell, Barbara; Spotila, James R.; Congdon, Justin

2006-01-01

The John Heinz National Wildlife Refuge is subject to pollution from multiple sources. We studied development of snapping turtle (Chelydra serpentina) and painted turtle (Chrysemys picta) embryos from the refuge from 2000 through 2003. Mean annual deformity rate of pooled painted turtle clutches over four years ranged from 45 to 71%, while that of snapping turtle clutches ranged from 13 to 19%. Lethal deformities were more common than minor or moderate deformities in embryos of both species. Adult painted turtles had a higher deformity rate than adult snapping turtles. Snapping turtles at JHNWR had high levels of PAH contamination in their fat. This suggests that PAHs are involved in the high level of deformities. Other contaminants may also play a role. Although the refuge offers many advantages to resident turtle populations, pollution appears to place a developmental burden on the life history of these turtles. - This paper presents findings on the prevalence of developmental abnormalities in turtles at a national wildlife refuge that have direct relevance to studies on the effects of contamination on development and morphology of vertebrates

Radiation and penetration matrix elements for magnetic quadrupole transitions between Nilsson states in odd nuclei

International Nuclear Information System (INIS)

Feresin, A.P.; Guseva, I.S.

1984-01-01

Single-particle matrix elements for magnetic quadrupole gamma radiation in odd deformed nuclei, calculated with the aid of Nilsson-potential wave functions, are presented. Also given are the internal conversion penetration matrix elements, calculated in the same manner. The penetration matrix elements are needed to estimate the nuclear penetration parameter, which determines the deviation of experimental internal conversion coefficients from their standard values given in tables. Matrix elements are given for transitions between all pairs of Nilsson single-particle states with ΔN = 1 and ΔK = 0, 1, and 2 for the nuclear shells with 4< or =N< or =7 and for the two deformation values epsilon = 0.2 and 0.3

High prevalence of morphometric vertebral deformities in patients with inflammatory bowel disease.

Science.gov (United States)

Heijckmann, Anna Caroline; Huijberts, Maya S P; Schoon, Erik J; Geusens, Piet; de Vries, Jolanda; Menheere, Paul P C A; van der Veer, Eveline; Wolffenbuttel, Bruce H R; Stockbrugger, Reinhold W; Dumitrescu, Bianca; Nieuwenhuijzen Kruseman, Arie C

2008-08-01

Earlier studies have documented that the prevalence of decreased bone mineral density (BMD) is elevated in patients with inflammatory bowel disease. The objective of this study was to investigate the prevalence of vertebral deformities in inflammatory bowel disease patients and their relation with BMD and bone turnover. One hundred and nine patients with Crohn's disease (CD) and 72 with ulcerative colitis (UC) (age 44.5+/-14.2 years) were studied. BMD of the hip (by dual X-ray absorptiometry) was measured and a lateral single energy densitometry of the spine for assessment of vertebral deformities was performed. Serum markers of bone resorption (carboxy-terminal cross-linked telopeptide of type I collagen) and formation (procollagen type I amino-terminal propeptide) were measured, and determinants of prevalent vertebral deformities were assessed using logistic regression analysis. Vertebral deformities were found in 25% of both CD and UC patients. Comparing patients with and without vertebral deformities, no significant difference was found between Z-scores and T-scores of BMD, or levels of serum carboxy-terminal cross-linked telopeptide of type I collagen and serum procollagen type I amino-terminal propeptide. Using logistic regression analysis the only determinant of any morphometric vertebral deformity was sex. The presence of multiple vertebral deformities was associated with older age and glucocorticoid use. The prevalence of morphometric vertebral deformities is high in CD and UC. Male sex, but neither disease activity, bone turnover markers, clinical risk factors, nor BMD predicted their presence. The determinants for having more than one vertebral deformity were age and glucocorticoid use. This implies that in addition to screening for low BMD, morphometric assessment of vertebral deformities is warranted in CD and UC.

Odd nitrogen production by meteoroids

Science.gov (United States)

Park, C.; Menees, G. P.

1978-01-01

The process by which odd nitrogen species (atomic nitrogen and nitric oxide) are formed during atmospheric entry of meteoroids is analyzed theoretically. An ablating meteoroid is assumed to be a point source of mass with a continuum regime evolving in its wake. The amounts of odd nitrogen species, produced by high-temperature reactions of air in the continuum wake, are calculated by numerical integration of chemical rate equations. Flow properties are assumed to be uniform across the wake, and 29 reactions involving five neutral species and five singly ionized species are considered, as well as vibrational and electron temperature nonequilibrium phenomena. The results, when they are summed over the observed mass, velocity, and entry-angle distribution of meteoroids, provide odd-nitrogen-species annual global production rates as functions of altitude. The peak production of nitric oxide is found to occur at an altitude of about 85 km; atomic nitrogen production peaks at about 95 km. The total annual rate for nitric oxide is 40 million kg; for atomic nitrogen it is 170 million kg.

External validation of the adult spinal deformity (ASD) frailty index (ASD-FI).

Science.gov (United States)

Miller, Emily K; Vila-Casademunt, Alba; Neuman, Brian J; Sciubba, Daniel M; Kebaish, Khaled M; Smith, Justin S; Alanay, Ahmet; Acaroglu, Emre R; Kleinstück, Frank; Obeid, Ibrahim; Sánchez Pérez-Grueso, Francisco Javier; Carreon, Leah Y; Schwab, Frank J; Bess, Shay; Scheer, Justin K; Lafage, Virginie; Shaffrey, Christopher I; Pellisé, Ferran; Ames, Christopher P

2018-03-30

To assess the ability of the recently developed adult spinal deformity frailty index (ASD-FI) to predict odds of perioperative complications, odds of reoperation, and length of hospital stay after adult spinal deformity (ASD) surgery using a database other than the one used to create the index. We used the ASD-FI to calculate frailty scores for 266 ASD patients who had minimum postoperative follow-up of 2 years in the European Spine Study Group (ESSG) database. Patients were enrolled from 2012 through 2013. Using ASD-FI scores, we categorized patients as not frail (NF) ( 0.5 points). Multivariable logistic regression, adjusted for preoperative and surgical factors such as operative time and blood loss, was performed to determine the relationship between ASD-FI category and odds of major complications, odds of reoperation, and length of hospital stay. We categorized 135 patients (51%) as NF, 90 patients (34%) as frail, and 41 patients (15%) as SF. Overall mean ASD-FI score was 0.29 (range 0-0.8). The adjusted odds of experiencing a major intraoperative or postoperative complication (OR 4.5, 95% CI 2.0-10) or having a reoperation (OR 3.9, 95% CI 1.7-8.9) were higher for SF patients compared with NF patients. Mean hospital stay was 2.1 times longer (95% CI 1.8-2.4) for SF patients compared with NF patients. Greater patient frailty, as measured by the ASD-FI, is associated with longer hospital stays and greater odds of major complications and reoperation. These slides can be retrieved under Electronic Supplementary Material.

Highly Deformable Origami Paper Photodetector Arrays

KAUST Repository

Lin, Chun-Ho

2017-09-25

Flexible electronics will form the basis of many next-generation technologies, such as wearable devices, biomedical sensors, the Internet of things, and more. However, most flexible devices can bear strains of less than 300% as a result of stretching. In this work, we demonstrate a simple and low-cost paper-based photodetector array featuring superior deformability using printable ZnO nanowires, carbon electrodes, and origami-based techniques. With a folded Miura structure, the paper photodetector array can be oriented in four different directions via tessellated parallelograms to provide the device with excellent omnidirectional light harvesting capabilities. Additionally, we demonstrate that the device can be repeatedly stretched (up to 1000% strain), bent (bending angle ±30°), and twisted (up to 360°) without degrading performance as a result of the paper folding technique, which enables the ZnO nanowire layers to remain rigid even as the device is deformed. The origami-based strategy described herein suggests avenues for the development of next-generation deformable optoelectronic applications.

Simultaneous correction of large low-order and high-order aberrations with a new deformable mirror technology

Science.gov (United States)

Rooms, F.; Camet, S.; Curis, J. F.

2010-02-01

A new technology of deformable mirror will be presented. Based on magnetic actuators, these deformable mirrors feature record strokes (more than +/- 45μm of astigmatism and focus correction) with an optimized temporal behavior. Furthermore, the development has been made in order to have a large density of actuators within a small clear aperture (typically 52 actuators within a diameter of 9.0mm). We will present the key benefits of this technology for vision science: simultaneous correction of low and high order aberrations, AO-SLO image without artifacts due to the membrane vibration, optimized control, etc. Using recent papers published by Doble, Thibos and Miller, we show the performances that can be achieved by various configurations using statistical approach. The typical distribution of wavefront aberrations (both the low order aberration (LOA) and high order aberration (HOA)) have been computed and the correction applied by the mirror. We compare two configurations of deformable mirrors (52 and 97 actuators) and highlight the influence of the number of actuators on the fitting error, the photon noise error and the effective bandwidth of correction.

A two-dimensional deformable phantom for quantitatively verifying deformation algorithms

Energy Technology Data Exchange (ETDEWEB)

Kirby, Neil; Chuang, Cynthia; Pouliot, Jean [Department of Radiation Oncology, University of California San Francisco, San Francisco, California 94143-1708 (United States)

2011-08-15

Purpose: The incorporation of deformable image registration into the treatment planning process is rapidly advancing. For this reason, the methods used to verify the underlying deformation algorithms must evolve equally fast. This manuscript proposes a two-dimensional deformable phantom, which can objectively verify the accuracy of deformation algorithms, as the next step for improving these techniques. Methods: The phantom represents a single plane of the anatomy for a head and neck patient. Inflation of a balloon catheter inside the phantom simulates tumor growth. CT and camera images of the phantom are acquired before and after its deformation. Nonradiopaque markers reside on the surface of the deformable anatomy and are visible through an acrylic plate, which enables an optical camera to measure their positions; thus, establishing the ground-truth deformation. This measured deformation is directly compared to the predictions of deformation algorithms, using several similarity metrics. The ratio of the number of points with more than a 3 mm deformation error over the number that are deformed by more than 3 mm is used for an error metric to evaluate algorithm accuracy. Results: An optical method of characterizing deformation has been successfully demonstrated. For the tests of this method, the balloon catheter deforms 32 out of the 54 surface markers by more than 3 mm. Different deformation errors result from the different similarity metrics. The most accurate deformation predictions had an error of 75%. Conclusions: The results presented here demonstrate the utility of the phantom for objectively verifying deformation algorithms and determining which is the most accurate. They also indicate that the phantom would benefit from more electron density heterogeneity. The reduction of the deformable anatomy to a two-dimensional system allows for the use of nonradiopaque markers, which do not influence deformation algorithms. This is the fundamental advantage of this

High-lying Gamow-Teller excited states in the deformed nuclei,76Ge,82Se and N = 20 nuclei in the island of inversion by the Deformed QRPA (DQRPA)

Science.gov (United States)

Cheoun, Myung-Ki; Ha, Eunja

2013-07-01

With the advent of high analysis technology in detecting the Gamow-Teller (GT) excited states beyond one nucleon emission threshold, the quenching of the GT strength to the Ikeda sum rule (ISR) seems to be recovered by the high-lying (HL) GT states. We address that these HL GT excited states result from the smearing of the Fermi surface by the increase of the chemical potential owing to the deformation within a framework of the deformed quasi-particle random phase approximation (DQRPA). Detailed mechanism leading to the smearing is discussed, and comparisons to the available experimental data on 76Ge,82Se and N = 20 nuclei are shown to explain the strong peaks on the HL GT excited states.

High-lying Gamow-Teller excited states in the deformed nuclei,76Ge,82Se and N = 20 nuclei in the island of inversion by the Deformed QRPA (DQRPA)

International Nuclear Information System (INIS)

Cheoun, Myung-Ki; Ha, Eunja

2013-01-01

With the advent of high analysis technology in detecting the Gamow-Teller (GT) excited states beyond one nucleon emission threshold, the quenching of the GT strength to the Ikeda sum rule (ISR) seems to be recovered by the high-lying (HL) GT states. We address that these HL GT excited states result from the smearing of the Fermi surface by the increase of the chemical potential owing to the deformation within a framework of the deformed quasi-particle random phase approximation (DQRPA). Detailed mechanism leading to the smearing is discussed, and comparisons to the available experimental data on 76 Ge, 82 Se and N = 20 nuclei are shown to explain the strong peaks on the HL GT excited states

Three-dimensional modeling for deformation of austenitic NiTi shape memory alloys under high strain rate

Science.gov (United States)

Yu, Hao; Young, Marcus L.

2018-01-01

A three-dimensional model for phase transformation of shape memory alloys (SMAs) during high strain rate deformation is developed and is then calibrated based on experimental results from an austenitic NiTi SMA. Stress, strain, and martensitic volume fraction distribution during high strain rate deformation are simulated using finite element analysis software ABAQUS/standard. For the first time, this paper presents a theoretical study of the microscopic band structure during high strain rate compressive deformation. The microscopic transformation band is generated by the phase front and leads to minor fluctuations in sample deformation. The strain rate effect on phase transformation is studied using the model. Both the starting stress for transformation and the slope of the stress-strain curve during phase transformation increase with increasing strain rate.

Design of a self-calibration high precision micro-angle deformation optical monitoring scheme

Science.gov (United States)

Gu, Yingying; Wang, Li; Guo, Shaogang; Wu, Yun; Liu, Da

2018-03-01

In order to meet the requirement of high precision and micro-angle measurement on orbit, a self-calibrated optical non-contact real-time monitoring device is designed. Within three meters, the micro-angle variable of target relative to measuring basis can be measured in real-time. The range of angle measurement is +/-50'', the angle measurement accuracy is less than 2''. The equipment can realize high precision real-time monitoring the micro-angle deformation, which caused by high strength vibration and shock of rock launching, sun radiation and heat conduction on orbit and so on.

Constraints on a parity-even/time-reversal-odd interaction

International Nuclear Information System (INIS)

Oers, Willem T.H. van

2000-01-01

Time-Reversal-Invariance non-conservation has for the first time been unequivocally demonstrated in a direct measurement, one of the results of the CPLEAR experiment. What is the situation then with regard to time-reversal-invariance non-conservation in systems other than the neutral kaon system? Two classes of tests of time-reversal-invariance need to be distinguished: the first one deals with parity violating (P-odd)/time-reversal-invariance non-conserving (T-odd) interactions, while the second one deals with P-even/T-odd interactions (assuming CPT conservation this implies C-conjugation non-conservation). Limits on a P-odd/T-odd interaction follow from measurements of the electric dipole moment of the neutron. This in turn provides a limit on a P-odd/T-odd pion-nucleon coupling constant which is 10 -4 times the weak interaction strength. Limits on a P-even/T-odd interaction are much less stringent. The better constraint stems also from the measurement of the electric dipole moment of the neutron. Of all the other tests, measurements of charge-symmetry breaking in neutron-proton elastic scattering provide the next better constraint. The latter experiments were performed at TRIUMF (at 477 and 347 MeV) and at IUCF (at 183 MeV). Weak decay experiments (the transverse polarization of the muon in K + →π 0 μ + ν μ and the transverse polarization of the positrons in polarized muon decay) have the potential to provide comparable or possibly better constraints

A systematic study of band structure and electromagnetic properties of neutron rich odd mass Eu isotopes in the projected shell model framework

Energy Technology Data Exchange (ETDEWEB)

Pandit, Rakesh K.; Devi, Rani [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)

2017-10-15

The positive and negative parity rotational band structure of the neutron rich odd mass Eu isotopes with neutron numbers ranging from 90 to 96 are investigated up to the high angular momentum. In the theoretical analysis of energy spectra, transition energies and electromagnetic transition probabilities we employ the projected shell model. The calculations successfully describe the formation of the ground and excited band structures from the single particle and multi quasiparticle configurations. Calculated excitation energy spectra, transition energies, exact quantum mechanically calculated B(E2) and B(M1) transition probabilities are compared with experimental data wherever available and a reasonably good agreement is obtained with the observed data. The change in deformation in the ground state band with the increase in angular momentum and the increase in neutron number has also been established. (orig.)

Emotional Abilities in Children with Oppositional Defiant Disorder (ODD): Impairments in Perspective-Taking and Understanding Mixed Emotions are Associated with High Callous-Unemotional Traits.

Science.gov (United States)

O'Kearney, Richard; Salmon, Karen; Liwag, Maria; Fortune, Clare-Ann; Dawel, Amy

2017-04-01

Most studies of emotion abilities in disruptive children focus on emotion expression recognition. This study compared 74 children aged 4-8 years with ODD to 45 comparison children (33 healthy; 12 with an anxiety disorder) on behaviourally assessed measures of emotion perception, emotion perspective-taking, knowledge of emotions causes and understanding ambivalent emotions and on parent-reported cognitive and affective empathy. Adjusting for child's sex, age and expressive language ODD children showed a paucity in attributing causes to emotions but no other deficits relative to the comparison groups. ODD boys with high levels of callous-unemotional traits (CU) (n = 22) showed deficits relative to low CU ODD boys (n = 25) in emotion perspective-taking and in understanding ambivalent emotions. Low CU ODD boys did not differ from the healthy typically developing boys (n = 12). Impairments in emotion perceptive-taking and understanding mixed emotions in ODD boys are associated with the presence of a high level of CU.

The results of high tibial open wedge osteotomy in patients with varus deformity

Directory of Open Access Journals (Sweden)

Mahmood Jabalameli

2013-07-01

Full Text Available Background: High tibial open wedg osteotomy is one of the most important modality for treatment of varus deformity in order to correct deformity and improving signs and symptoms of patients with primary degenerative osteoarthritis. The aim of this study was to investigate the results of high tibial open wedge osteotomy in patients with varus deformities.Methods: This retrospective study conducted on twenty nine patients (36 knees undergone proximal tibial osteotomy operation in Shafa Yahyaian University Hospital from 2004 to 2010. Inclusion criteria were: age less than 60 years, high physical activity, varus deformity and involvement of medical compartment of knee. Patients with obesity, smoking, patelofemoral pain, lateral compartment lesion, deformity degree more than 20 degree, extension limitation and range of motion less than 90 degree were excluded. The clinical and radiologic characteristics were measured before and after operation.Results: Fourteen patients were females. All of them were younger than 50 years, with mean (±SD 27.64 (±10.88. The mean (±SD of follow up time was 4.33 (±1.7. All the patients were satisfied with the results of operation. Tenderness and pain decreased in all of them. In all patients autologus bone graft were used, in 15 cases (42.5% casting and in the rest T.Buttress plate were used for fixation of fractures. In both groups of primary and double varus the International knee documentation committee (IKDC and modified Larson indices were improved after operation, but there was no significant difference between two groups.Conclusion: High tibial open wedge osteotomy can have satisfying results in clinical signs and symptoms of patients with primary medial joint degenerative osteoarthritis. This procedure also may correct the deformity and improves the radiologic parameters of the patients.

High temperature deformation of silicon steel

International Nuclear Information System (INIS)

Rodríguez-Calvillo, Pablo; Houbaert, Yvan; Petrov, Roumen; Kestens, Leo; Colás, Rafael

2012-01-01

The microstructure and texture development during high temperature plane strain compression of 2% in weight silicon steel was studied. The tests were carried out at a constant strain rate of 5 s −1 with reductions of 25, 35 and 75% at temperatures varying from 800 to 1100 °C. The changes in microstructure and texture were studied by means of scanning electron microscopy and electron backscattered diffraction. The microstructure close to the surface of the samples was equiaxed, which is attributed to the shear caused by friction, whereas that at the centre of the specimens was made of a mixture of elongated and fine equiaxed grains, the last ones attributed to the action of dynamic recovery followed by recrystallization. It was found that the volume fraction of these equiaxed grains augmented as reduction and temperature increased; a 0.7 volume fraction was accomplished with a 75% reduction at 1100 °C. The texture of the equiaxed and elongated grains was found to vary with the increase of deformation and temperature, as the γ-fibre tends to disappear and the α-fibre to increase towards the higher temperature range. -- Highlights: ► The plastic deformation of a silicon containing steel is studied by plane strain compression. ► Equiaxed and elongated grains develop in different regions of the sample due to recrystallization. ► Texture, by EBSD, is revealed to be similar in either type of grains.

High temperature deformation of silicon steel

Energy Technology Data Exchange (ETDEWEB)

Rodriguez-Calvillo, Pablo, E-mail: pablo.rodriguez@ctm.com.es [CTM - Technologic Centre, Materials Technology Area, Manresa, Cataluna (Spain); Department of Materials Science and Metallurgical Engineering, Universidad Politecnica de Cataluna, Barcelona (Spain); Houbaert, Yvan, E-mail: Yvan.Houbaert@UGent.be [Department of Materials Science and Engineering, University of Ghent (Belgium); Petrov, Roumen, E-mail: Roumen.Petrov@ugent.be [Department of Materials Science and Engineering, University of Ghent (Belgium); Kestens, Leo, E-mail: Leo.kestens@ugent.be [Department of Materials Science and Engineering, University of Ghent (Belgium); Colas, Rafael, E-mail: rafael.colas@uanl.edu.mx [Facultad de Ingenieria Mecanica y Electrica, Universidad Autonoma de Nuevo Leon (Mexico); Centro de Innovacion, Investigacion y Desarrollo en Ingenieria y Tecnologia, Universidad Autonoma de Nuevo Leon (Mexico)

2012-10-15

The microstructure and texture development during high temperature plane strain compression of 2% in weight silicon steel was studied. The tests were carried out at a constant strain rate of 5 s{sup -1} with reductions of 25, 35 and 75% at temperatures varying from 800 to 1100 Degree-Sign C. The changes in microstructure and texture were studied by means of scanning electron microscopy and electron backscattered diffraction. The microstructure close to the surface of the samples was equiaxed, which is attributed to the shear caused by friction, whereas that at the centre of the specimens was made of a mixture of elongated and fine equiaxed grains, the last ones attributed to the action of dynamic recovery followed by recrystallization. It was found that the volume fraction of these equiaxed grains augmented as reduction and temperature increased; a 0.7 volume fraction was accomplished with a 75% reduction at 1100 Degree-Sign C. The texture of the equiaxed and elongated grains was found to vary with the increase of deformation and temperature, as the {gamma}-fibre tends to disappear and the {alpha}-fibre to increase towards the higher temperature range. -- Highlights: Black-Right-Pointing-Pointer The plastic deformation of a silicon containing steel is studied by plane strain compression. Black-Right-Pointing-Pointer Equiaxed and elongated grains develop in different regions of the sample due to recrystallization. Black-Right-Pointing-Pointer Texture, by EBSD, is revealed to be similar in either type of grains.

Monitoring microstructural evolution in-situ during cyclic deformation by high resolution reciprocal space mapping

DEFF Research Database (Denmark)

Diederichs, Annika Martina; Thiel, Felix; Fischer, Torben

2017-01-01

The recently developed synchrotron technique High Resolution Reciprocal Space Mapping (HRRSM) is used to characterize the deformation structures evolving during cyclic deformation of commercially pure, polycrystalline aluminium AA1050. Insight into the structural reorganization within single grains...... is gained by in-situ monitoring of the microstructural evolution during cyclic deformation. By HRRSM, a large number of individual subgrains can be resolved within individual grains in the bulk of polycrystalline specimens and their fate, their individual orientation and elastic stresses, tracked during...

On the High Temperature Deformation Behaviour of 2507 Super Duplex Stainless Steel

Science.gov (United States)

Mishra, M. K.; Balasundar, I.; Rao, A. G.; Kashyap, B. P.; Prabhu, N.

2017-02-01

High temperature deformation behaviour of 2507 super duplex stainless steel was investigated by conducting isothermal hot compression tests. The dominant restoration processes in ferrite and austenite phases present in the material were found to be distinct. The possible causes for these differences are discussed. Based on the dynamic materials model, processing map was developed to identify the optimum processing parameters. The microstructural mechanisms operating in the material were identified. A unified strain-compensated constitutive equation was established to describe the high temperature deformation behaviour of the material under the identified processing conditions. Standard statistical parameter such as correlation coefficient has been used to validate the established equation.

Odd-frequency pairing in superconducting heterostructures

Energy Technology Data Exchange (ETDEWEB)

Golubov, A A [Faculty of Science and Technology and MESA Institute for Nanotechnology, University of Twente, 7500 AE Enschede (Netherlands); Tanaka, Y [Department of Applied Physics, Nagoya University, Nagoya, 464-8603 (Japan); Asano, Y [Department of Applied Physics, Hokkaido University, Sapporo 060-8628 (Japan); Tanuma, Y [Institute of Physics, Kanagawa University, 3-7-1, Rokkakubashi, Kanagawa-ku, Yokohama 221-8686 (Japan)], E-mail: a.golubov@utwente.nl

2009-04-22

We review the theory of odd-frequency pairing in superconducting heterostructures, where an odd-frequency pairing component is induced near interfaces. A general description of the superconducting proximity effect in a normal metal or a ferromagnet attached to an unconventional superconductor (S) is given within quasiclassical kinetic theory for various types of symmetry state in S. Various possible symmetry classes in a superconductor are considered which are consistent with the Pauli principle: even-frequency spin-singlet even-parity (ESE) state, even-frequency spin-triplet odd-parity (ETO) state, odd-frequency spin-triplet even-parity (OTE) state and odd-frequency spin-singlet odd-parity (OSO) state. As an example, we consider a junction between a diffusive normal metal (DN) and a p-wave superconductor (even-frequency spin-triplet odd-parity symmetry), where the pairing amplitude in DN belongs to an odd-frequency spin-triplet even-parity symmetry class. We also discuss the manifestation of odd-frequency pairing in conventional superconductor/normal (S/N) proximity systems and its relation to the classical McMillan-Rowell oscillations.

Structural evolution of a deformed Σ=9 (122) grain boundary in silicon. A high resolution electron microscopy study

International Nuclear Information System (INIS)

Putaux, Jean-Luc

1991-01-01

This research thesis addresses the study by high resolution electron microscopy of the evolution of a silicon bi-crystal under deformation at different temperatures. The author notably studied the structural evolution of the boundary as well as that of grains at the vicinity of the boundary. Two observation scales have been used: the evolution of sub-structures of dislocations induced by deformation in grains and in boundary, and the structure of all defects at an atomic scale. After a presentation of experimental tools (the necessary perfect quality of the electronic optics is outlined), the author recalls some descriptive aspects of grain boundaries (geometric network concepts to describe coinciding networks, concepts of delimiting boundaries and of structural unit to describe grain boundary atomic structure), recalls the characteristics of the studied bi-crystal, and the conditions under which it is deformed. He presents the structures of all perfectly coinciding boundaries, describes defects obtained by deformation at the vicinity of the boundary, describes the entry of dissociated dislocations into the boundaries, and discusses the characterization of boundary dislocations (the notion of Burgers vector is put into question again), and the atomic mechanism of displacement of dislocations in boundaries [fr

Characterization of low-mass deformable mirrors and ASIC drivers for high-contrast imaging

Science.gov (United States)

Mejia Prada, Camilo; Yao, Li; Wu, Yuqian; Roberts, Lewis C.; Shelton, Chris; Wu, Xingtao

2017-09-01

The development of compact, high performance Deformable Mirrors (DMs) is one of the most important technological challenges for high-contrast imaging on space missions. Microscale Inc. has fabricated and characterized piezoelectric stack actuator deformable mirrors (PZT-DMs) and Application-Specific Integrated Circuit (ASIC) drivers for direct integration. The DM-ASIC system is designed to eliminate almost all cables, enabling a very compact optical system with low mass and low power consumption. We report on the optical tests used to evaluate the performance of the DM and ASIC units. We also compare the results to the requirements for space-based high-contrast imaging of exoplanets.

Thermal deformation analysis and test of electron gun for high power klystron

International Nuclear Information System (INIS)

Zhou Zusheng; Chinese Academy of Sciences, Beijing; Dong Dong

2006-01-01

A 120 MW pulsed electron gun has been developed for 50 MW China-made klystron. It has a Pierce type dispenser cathode and it scans with a diameter of 85 mm. This paper describes the temperature field distribution in the gun and the gun deformation caused by this distribution by using ANSYS. According to the real complex structure and the energy conversion inside the electron gun, the authors took the thermal conduction as the main energy conversion form and got the temperature field. The coincidence between the temperature field and the structural deformation is also described. The beam optics simulated by EGUN with and without considering deformation is discussed, and the valuable results have been obtained. The high power test results and simulation results are analyzed and compared. (authors)

Projected shell model study of odd-odd f-p-g shell proton-rich nuclei

International Nuclear Information System (INIS)

Palit, R.; Sheikh, J.A.; Sun, Y.; Jain, H.C.

2003-01-01

A systematic study of two-quasiparticle bands of the proton-rich odd-odd nuclei in the mass A∼70-80 region is performed using the projected shell model approach. The study includes Br, Rb, and Y isotopes with N=Z+2 and Z+4. We describe the energy spectra and electromagnetic transition strengths in terms of the configuration mixing of the angular-momentum projected multi-quasiparticle states. Signature splitting and signature inversion in the rotational bands are discussed and are shown to be well described. A preliminary study of the odd-odd N=Z nucleus 74 Rb, using the concept of spontaneous symmetry breaking is also presented

Features micro plastic deformation auxetic beryllium irradiated with high-energy electrons

International Nuclear Information System (INIS)

Rarans'kij, M.D.; Olyijnich-Lisyuk, A.V.; Tashchuk, O.Yu.

2016-01-01

By low-frequency internal friction (LFIF) (1...3 Hz) method, the study of the behavior of the dynamic modulus of torsion (Gef) and by mathematical modeling of dislocation motion studied micro plastic deformation in naturally aged and irradiated with high-energy (18 MeV) electrons auxetic beryllium. With increasing doses of radiation found an increase in IF and speed of movement of dislocations in 2-3 times. Installed stage character micro strain auxetic Be. By mathematical modeling showed that in the irradiated material the deformation occurs due to the accelerated movement of the twin dislocations in the early stages, and anomalous dynamic deceleration of complete dislocations with an increase in the degree of deformation in the second stage. It is shown that theoretically estimated values are in good agreement with the experimentally determined.

Plastic deformation

NARCIS (Netherlands)

Sitter, de L.U.

1937-01-01

§ 1. Plastic deformation of solid matter under high confining pressures has been insufficiently studied. Jeffreys 1) devotes a few paragraphs to deformation of solid matter as a preface to his chapter on the isostasy problem. He distinguishes two properties of solid matter with regard to its

Iron-Based Superconductors as Odd-Parity Superconductors

Directory of Open Access Journals (Sweden)

Jiangping Hu

2013-07-01

Full Text Available Parity is a fundamental quantum number used to classify a state of matter. Materials rarely possess ground states with odd parity. We show that the superconducting state in iron-based superconductors is classified as an odd-parity s-wave spin-singlet pairing state in a single trilayer FeAs/Se, the building block of the materials. In a low-energy effective model constructed on the Fe square bipartite lattice, the superconducting order parameter in this state is a combination of an s-wave normal pairing between two sublattices and an s-wave η pairing within the sublattices. The state has a fingerprint with a real-space sign inversion between the top and bottom As/Se layers. The results suggest that iron-based superconductors are a new quantum state of matter, and the measurement of the odd parity can help to establish high-temperature superconducting mechanisms.

Deformation-Induced Dissolution and Precipitation of Nitrides in Austenite and Ferrite of a High-Nitrogen Stainless Steel

Science.gov (United States)

Shabashov, V. A.; Makarov, A. V.; Kozlov, K. A.; Sagaradze, V. V.; Zamatovskii, A. E.; Volkova, E. G.; Luchko, S. N.

2018-02-01

Methods of Mössbauer spectroscopy and electron microscopy have been used to study the effect of the severe plastic deformation by high pressure torsion in Bridgman anvils on the dissolution and precipitation of chromium nitrides in the austenitic and ferritic structure of an Fe71.2Cr22.7Mn1.3N4.8 high-nitrogen steel. It has been found that an alternative process of dynamic aging with the formation of secondary nitrides affects the kinetics of the dissolution of chromium nitrides. The dynamic aging of ferrite is activated with an increase in the deformation temperature from 80 to 573 K.

A Comprehensive Analysis of the SRS-Schwab Adult Spinal Deformity Classification and Confounding Variables: A Prospective, Non-US Cross-sectional Study in 292 Patients.

Science.gov (United States)

Hallager, Dennis Winge; Hansen, Lars Valentin; Dragsted, Casper Rokkjær; Peytz, Nina; Gehrchen, Martin; Dahl, Benny

2016-05-01

Cross-sectional analyses on a consecutive, prospective cohort. To evaluate the ability of the Scoliosis Research Society (SRS)-Schwab Adult Spinal Deformity Classification to group patients by widely used health-related quality-of-life (HRQOL) scores and examine possible confounding variables. The SRS-Schwab Adult Spinal Deformity Classification includes sagittal modifiers considered important for HRQOL and the clinical impact of the classification has been validated in patients from the International Spine Study Group database; however, equivocal results were reported for the Pelvic Tilt modifier and potential confounding variables were not evaluated. Between March 2013 and May 2014, all adult spinal deformity patients from our outpatient clinic with sufficient radiographs were prospectively enrolled. Analyses of HRQOL variance and post hoc analyses were performed for each SRS-Schwab modifier. Age, history of spine surgery, and aetiology of spinal deformity were considered potential confounders and their influence on the association between SRS-Schwab modifiers and aggregated Oswestry Disability Index (ODI) scores was evaluated with multivariate proportional odds regressions. P values were adjusted for multiple testing. Two hundred ninety-two of 460 eligible patients were included for analyses. The SRS-Schwab Classification significantly discriminated HRQOL scores between normal and abnormal sagittal modifier classifications. Individual grade comparisons showed equivocal results; however, Pelvic Tilt grade + versus +  + did not discriminate patients according to any HRQOL score. All modifiers showed significant proportional odds for worse aggregated ODI scores with increasing grade levels and the effects were robust to confounding. However, age group and aetiology had individual significant effects. The SRS-Schwab sagittal modifiers reliably grouped patients graded 0 versus + / +  + according to the most widely used HRQOL scores and the

Deformation of high-speed meteor bodies by the atmosphere

International Nuclear Information System (INIS)

Maslov, I V; Gorshkov, A V

2012-01-01

We model the deformation that a meteorite can undergo during its passage through the atmosphere. First, the pressure distribution around a solid body in a flow was measured in a wind tunnel. Second, the deformation of molten tin droplets with different temperatures dropped into water was observed. Finally, a mathematical model of the fall was constructed to determine what pressure the meteorite experiences in the atmosphere and whether it is enough to deform it. (paper)

Full-frame, high-speed 3D shape and deformation measurements using stereo-digital image correlation and a single color high-speed camera

Science.gov (United States)

Yu, Liping; Pan, Bing

2017-08-01

Full-frame, high-speed 3D shape and deformation measurement using stereo-digital image correlation (stereo-DIC) technique and a single high-speed color camera is proposed. With the aid of a skillfully designed pseudo stereo-imaging apparatus, color images of a test object surface, composed of blue and red channel images from two different optical paths, are recorded by a high-speed color CMOS camera. The recorded color images can be separated into red and blue channel sub-images using a simple but effective color crosstalk correction method. These separated blue and red channel sub-images are processed by regular stereo-DIC method to retrieve full-field 3D shape and deformation on the test object surface. Compared with existing two-camera high-speed stereo-DIC or four-mirror-adapter-assisted singe-camera high-speed stereo-DIC, the proposed single-camera high-speed stereo-DIC technique offers prominent advantages of full-frame measurements using a single high-speed camera but without sacrificing its spatial resolution. Two real experiments, including shape measurement of a curved surface and vibration measurement of a Chinese double-side drum, demonstrated the effectiveness and accuracy of the proposed technique.

Subcoulomb fusion of 16O in odd Sm isotopes

International Nuclear Information System (INIS)

Pacheco, A.J.

1989-01-01

Cross sections for the formation of evaporation residues were measured for the reaction of 16 O with the odd 147 Sm and 149 Sm nuclei at near barrier energies. The results are well described by statistical model calculations. Fusion cross sections as a function of energy do not show any unusual behaviour that could be attributed to the presence of unpaired nucleons. An analysis based on a one-dimensional penetration model that includes the effect of permanent quadrupolar deformations shows that the extracted values of the parameter β 2 follow the systematics established by the rest of the even samarium isotopes. The dependence of β 2 on the mass of the target nucleus indicates that the influence exerted by collective aspects upon the subbarrier fusion process increases rapidly as a function of the number of neutrons added to the spherical semimagic 144 Sm nucleus. (Author) [es

Spinal deformities after high-energy radiotherapy for nephroblastoma in children. Report of 82 cases

Energy Technology Data Exchange (ETDEWEB)

Zollner, G.; Pfeil, J.; Scheibel, P.

1987-01-01

Study of spinal deformities in 82 cases of nephroblastoma treated surgically or by chemotherapy and high-energy radiotherapy. This paper stresses the high incidence of radiation induced scoliosis which was observed in all patients who had reached adulthood. On the basis of a detailed analysis of the relations between the height of the vertebral body and of the intervertebral space, the authors propose a theory of a compensation of the reduction in vertebral height by displacement the nucleus pulposus towards the irradiated side. This phenomenon prevents the development of scoliosis in subjects under the age of 11 years, despite an already well established deformity of the vertebral bodies. The compensation decreases with increasing age and the degree od scoliosis. This explains partly the increased degree of scoliotic deformity during puberty. Orthopaedic treatment therefore needs to be started relatively early.

Mechanical twinning and texture evolution in severely deformed Ti-6Al-4V at high temperatures

International Nuclear Information System (INIS)

Yapici, Guney Guven; Karaman, Ibrahim; Luo Zhiping

2006-01-01

We have investigated the deformation behavior and texture evolution of two-phase Ti-6Al-4V subjected to severe plastic deformation using equal channel angular extrusion (ECAE) at a high temperature (∼0.55T m ). Significant deformation twinning activity was observed after one and two ECAE passes in a 90 deg, die at 800 deg. C. Twinning activity at such a high temperature is a first-time observation in this material and is attributed to the high strain and stress levels imposed during ECAE. High stress levels and the stress state can affect the separation of twinning partials considerably. Resolved shear stress magnitudes on twin partials were found to be high during the ECAE process that helps the nucleation of mechanical twinning. The twinning mode was identified as the {101-bar 1} type using electron diffraction patterns which is one of the twinning modes observed in Ti at temperatures above 350 deg. C. Although only one twinning variant was mainly evident after one pass, multiple twin variants of the same mode were observed after the second pass with a significant increase in twin volume fraction. ECAE processing aligned the basal planes of the hexagonal close-packed α phase, initially having a random texture, with the ECAE shear plane. Texture evolution during ECAE was successfully predicted using a viscoplastic self-consistent crystal plasticity framework capturing the effect of the observed twinning mode on texture. Mechanical twins formed during ECAE and grain refinement led to a noteworthy improvement in flow stresses under tension and compression at room temperature. A strong directional anisotropy in yield strengths was also evident which cannot be explained only by crystallographic texture. It was speculated that the asymmetry of critical resolved shear stresses of deformation modes and the processing-induced deformation structure should play a role. With the supporting evidence from our previous works on the severe plastic deformation of other

A model of high-rate indentation of a cylindrical striking pin into a deformable body

Science.gov (United States)

Zalazinskaya, E. A.; Zalazinsky, A. G.

2017-12-01

Mathematical modeling of an impact and high-rate indentation to a significant depth of a flat-faced hard cylindrical striking pin into a massive deformable target body is carried out. With the application of the kinematic extreme theorem of the plasticity theory and the kinetic energy variation theorem, the phase trajectories of the striking pin are calculated, the initial velocity of the striking pin in the body, the limit values of the inlet duct length, and the depth of striking pin penetration into the target are determined.

High spin states and isomeric decays in doubly-odd {sup 208}Fr

Energy Technology Data Exchange (ETDEWEB)

Kanjilal, D.; Bhattacharya, S.; Goswami, A.; Kshetri, R.; Raut, R. [Nuclear and Atomic Physics Division, Saha Institute of Nuclear Physics, Kolkata 700064 (India); Saha, S., E-mail: satyajit.saha@saha.ac.i [Nuclear and Atomic Physics Division, Saha Institute of Nuclear Physics, Kolkata 700064 (India); Bhowmik, R.K.; Gehlot, J.; Muralithar, S.; Singh, R.P. [Inter University Accelerator Centre, New Delhi 110067 (India); Jnaneswari, G. [Department of Physics, Andhra University, Vishakhapatnam 530003 (India); Mukherjee, G. [Variable Energy Cyclotron Centre, Kolkata 700064 (India); Mukherjee, B. [Department of Physics, Visva Bharati, Santiniketan 731235 (India)

2010-10-15

Neutron deficient isotopes of francium (Z=87, N{approx}121-123) as excited nuclei were produced in the fusion-evaporation reaction: {sup 197}Au({sup 16}O, xn) {sup 213-x}Fr at 100 MeV. The {gamma} rays from the residues were observed through the high sensitivity Germanium Clover detector array INGA. The decay of the high spin states and the isomeric states of the doubly-odd {sup 208}Fr nuclei, identified from the known sequence of ground state transitions, were observed. The half-lives of the E{sub {gamma}=}194(2) keV isomeric transition, known from earlier observations, was measured to be T{sub 1/2}=233(18) ns. A second isomeric transition at E{sub {gamma}=}383(2) keV and T{sub 1/2}=33(7) ns was also found. The measured half-lives were compared with the corresponding single particle estimates, based on the level scheme obtained from the experiment.

Energy of the 4(+) isomer and new bands in the odd-odd nucleus 74Br

International Nuclear Information System (INIS)

Doering, J.; Holcomb, J.W.; Johnson, T.D.; Riley, M.A.; Tabor, S.L.; Womble, P.C.; Winter, G.

1993-01-01

High-spin states of the odd-odd nucleus 74 Br were investigated via the reactions 58 Ni ( 19 F,2pn) 74 Br and 65 Cu( 12 C,3n) 74 Br at beam energies of 62 and 50 MeV, respectively. On the basis of coincidence data new levels have been introduced and partly grouped into rotational bands. Some of these new states decay to known levels of negative-parity bands built on both the ground state and the long-lived 4 (+) isomer. Thus, an excitation energy of 13.8 keV has been deduced for the long-lived isomer in 74 Br. The level sequences observed are interpreted in terms of Nilsson configurations in conjunction with collective excitations

Microscopic description of low-lying M1 excitations in odd-mass actinide nuclei

Energy Technology Data Exchange (ETDEWEB)

Tabar, Emre, E-mail: etabar@sakarya.edu.tr [Physics Department, Sakarya University, 54187 Sakarya (Turkey); Biomedical, Magnetic and Semiconductor Materials Research Center (BIMAS-RC), Sakarya University, 54187 Sakarya (Turkey); Yakut, Hakan, E-mail: hyakut@sakarya.edu.tr [Physics Department, Sakarya University, 54187 Sakarya (Turkey); Biomedical, Magnetic and Semiconductor Materials Research Center (BIMAS-RC), Sakarya University, 54187 Sakarya (Turkey); Kuliev, Ali Akbar [Azerbaijan National Academy of Aviation, Baku (Azerbaijan)

2017-01-15

A restoration method of a broken symmetry which allows self-consistent determination of the separable effective restoration forces is now adapted to odd-mass nuclei in order to restore violated rotational invariance (RI-) of the Quasiparticle Phonon Nuclear Model (QPNM) Hamiltonian. Because of the self-consistency of the method, these effective forces contain no arbitrary parameters. Within RI-QPNM, the properties of the low-lying magnetic dipole excitations in odd-mass deformed {sup 229–233}Th and {sup 233–239}U nuclei have been investigated for the first time. It has been shown that computed fragmentation of the M1 strengths below 4 MeV in these nuclei is much stronger than that in neighboring doubly even {sup 228–232}Th and {sup 232–238}U nuclei. For {sup 235}U the summed M1 strength in the energy range 1.5–2.8 MeV is in agreement with the relevant experimental data where the missing strength was extracted by means of a fluctuation analysis.

High-temperature deformation and processing maps of Zr-4 metal matrix with dispersed coated surrogate nuclear fuel particles

Science.gov (United States)

Chen, Jing; Liu, Huiqun; Zhang, Ruiqian; Li, Gang; Yi, Danqing; Lin, Gaoyong; Guo, Zhen; Liu, Shaoqiang

2018-06-01

High-temperature compression deformation of a Zr-4 metal matrix with dispersed coated surrogate nuclear fuel particles was investigated at 750 °C-950 °C with a strain rate of 0.01-1.0 s-1 and height reduction of 20%. Scanning electron microscopy was utilized to investigate the influence of the deformation conditions on the microstructure of the composite and damage to the coated surrogate fuel particles. The results indicated that the flow stress of the composite increased with increasing strain rate and decreasing temperature. The true stress-strain curves showed obvious serrated oscillation characteristics. There were stable deformation ranges at the initial deformation stage with low true strain at strain rate 0.01 s-1 for all measured temperatures. Additionally, the coating on the surface of the surrogate nuclear fuel particles was damaged when the Zr-4 matrix was deformed at conditions of high strain rate and low temperature. The deformation stability was obtained from the processing maps and microstructural characterization. The high-temperature deformation activation energy was 354.22, 407.68, and 433.81 kJ/mol at true strains of 0.02, 0.08, and 0.15, respectively. The optimum deformation parameters for the composite were 900-950 °C and 0.01 s-1. These results are expected to provide guidance for subsequent determination of possible hot working processes for this composite.

High Resolution Transmission Electron Microscope Observation of Zero-Strain Deformation Twinning Mechanisms in Ag

Science.gov (United States)

Liu, L.; Wang, J.; Gong, S. K.; Mao, S. X.

2011-04-01

We have observed a new deformation-twinning mechanism using the high resolution transmission electron microscope in polycrystalline Ag films, zero-strain twinning via nucleation, and the migration of a Σ3{112} incoherent twin boundary (ITB). This twinning mechanism produces a near zero macroscopic strain because the net Burgers vectors either equal zero or are equivalent to a Shockley partial dislocation. This observation provides new insight into the understanding of deformation twinning and confirms a previous hypothesis: detwinning could be accomplished via the nucleation and migration of Σ3{112} ITBs. The zero-strain twinning mechanism may be unique to low staking fault energy metals with implications for their deformation behavior.

Effect of initial grain size on inhomogeneous plastic deformation and twinning behavior in high manganese austenitic steel with a polycrystalline microstructure

Science.gov (United States)

Ueji, R.; Tsuchida, N.; Harada, K.; Takaki, K.; Fujii, H.

2015-08-01

The grain size effect on the deformation twinning in a high manganese austenitic steel which is so-called TWIP (twining induced plastic deformation) steel was studied in order to understand how to control deformation twinning. The 31wt%Mn-3%Al-3% Si steel was cold rolled and annealed at various temperatures to obtain fully recrystallized structures with different mean grain sizes. These annealed sheets were examined by room temperature tensile tests at a strain rate of 10-4/s. The coarse grained sample (grain size: 49.6μm) showed many deformation twins and the deformation twinning was preferentially found in the grains in which the tensile axis is parallel near to [111]. On the other hand, the sample with finer grains (1.8 μm) had few grains with twinning even after the tensile deformation. The electron back scattering diffraction (EB SD) measurements clarified the relationship between the anisotropy of deformation twinning and that of inhomogeneous plastic deformation. Based on the EBSD analysis, the mechanism of the suppression of deformation twinning by grain refinement was discussed with the concept of the slip pattern competition between the slip system governed by a grain boundary and that activated by the macroscopic load.

The effect of dispersoids on the grain refinement mechanisms during deformation of aluminium alloys to ultra-high strains

International Nuclear Information System (INIS)

Apps, P.J.; Berta, M.; Prangnell, P.B.

2005-01-01

The effect of fine dispersoids on the mechanisms and rate of grain refinement has been investigated during the severe deformation of a model aluminium alloy. A binary Al-0.2Sc alloy, containing coherent Al 3 Sc dispersoids, of ∼20 nm in diameter and ∼100 nm spacing, has been deformed by equal channel angular extrusion to an effective strain of ten. The resulting deformation structures were quantitatively analysed using high-resolution electron backscattered diffraction orientation mapping, and the results have been compared to those obtained from a single-phase Al-0.13Mg alloy, deformed under identical conditions. The presence of fine, non-shearable, dispersoids has been found to homogenise slip, retard the formation of a cellular substructure and inhibit the formation of microshear bands during deformation. These factors combine to reduce the rate of high-angle grain boundary generation at low to medium strains and, hence, retard the formation of a submicron grain structure to higher strains during severe deformation

Thermal stability of a highly-deformed warm-rolled tungsten plate in the temperature range 1100–1250 °C

Energy Technology Data Exchange (ETDEWEB)

Alfonso, A., E-mail: aalz@dtu.dk [Section of Materials and Surface Engineering, Department of Mechanical Engineering, Technical University of Denmark, 2800 Lyngby (Denmark); Sino-Danish Center for Education and Research, Denmark and China (Denmark); Juul Jensen, D. [Danish-Chinese Center for Nanometals, Section of Materials Science and Advanced Characterization, Department of Wind Energy, Technical University of Denmark, Risø Campus, 4000 Roskilde (Denmark); Sino-Danish Center for Education and Research, Denmark and China (Denmark); Luo, G.-N. [Fusion Reactor Materials Science and Technology Division, Institute of Plasma Physics, Chinese Academy of Sciences, 230031 Hefei, Anhui (China); Sino-Danish Center for Education and Research, Denmark and China (Denmark); Pantleon, W. [Section of Materials and Surface Engineering, Department of Mechanical Engineering, Technical University of Denmark, 2800 Lyngby (Denmark); Association EURATOM-DTU (Denmark); Sino-Danish Center for Education and Research, Denmark and China (Denmark)

2015-10-15

Highlights: • Annealing kinetics of highly-deformed tungsten up to 190 h between 1100 °C and 1250 °C. • Loss of mechanical strength characterized by Vickers hardness measurements. • Two distinct stages of recovery and recrystallization identified and described by established models. • Activation energy of recrystallization lower than after moderate deformation of tungsten. • Comparable to activation energy of grain boundary diffusion due to abundance of low angle boundaries. - Abstract: Pure tungsten is considered as armor material for the most critical parts of fusion reactors (i.e. the divertor and the first wall), among other reasons due to its high melting point (3422 °C) and recrystallization temperature. The thermal stability of a pure tungsten plate warm-rolled to a high plastic strain by 90% thickness reduction was investigated by isothermal annealing for up to 190 h in the temperature range between 1100 °C and 1250 °C. Vickers hardness testing allowed tracking the changes in mechanical properties caused by recovery and recrystallization. The hardness evolution could be rationalized in terms of a logarithmic recovery kinetics and a Johnson–Mehl–Avrami–Kolmogorov recrystallization kinetics accounting for an incubation time of recrystallization. The observed time spans for recrystallization and the corresponding recrystallization activation energy for this highly deformed plate suggest that large plastic deformations (e.g. applied during shaping) are only suitable to produce tungsten components to be used at relatively low temperatures (up to 900 °C for a 2 years lifespan). Higher operation temperatures will lead to fast degradation of the microstructure during operation.

Thermal stability of a highly-deformed warm-rolled tungsten plate in the temperature range 1100–1250 °C

International Nuclear Information System (INIS)

Alfonso, A.; Juul Jensen, D.; Luo, G.-N.; Pantleon, W.

2015-01-01

Highlights: • Annealing kinetics of highly-deformed tungsten up to 190 h between 1100 °C and 1250 °C. • Loss of mechanical strength characterized by Vickers hardness measurements. • Two distinct stages of recovery and recrystallization identified and described by established models. • Activation energy of recrystallization lower than after moderate deformation of tungsten. • Comparable to activation energy of grain boundary diffusion due to abundance of low angle boundaries. - Abstract: Pure tungsten is considered as armor material for the most critical parts of fusion reactors (i.e. the divertor and the first wall), among other reasons due to its high melting point (3422 °C) and recrystallization temperature. The thermal stability of a pure tungsten plate warm-rolled to a high plastic strain by 90% thickness reduction was investigated by isothermal annealing for up to 190 h in the temperature range between 1100 °C and 1250 °C. Vickers hardness testing allowed tracking the changes in mechanical properties caused by recovery and recrystallization. The hardness evolution could be rationalized in terms of a logarithmic recovery kinetics and a Johnson–Mehl–Avrami–Kolmogorov recrystallization kinetics accounting for an incubation time of recrystallization. The observed time spans for recrystallization and the corresponding recrystallization activation energy for this highly deformed plate suggest that large plastic deformations (e.g. applied during shaping) are only suitable to produce tungsten components to be used at relatively low temperatures (up to 900 °C for a 2 years lifespan). Higher operation temperatures will lead to fast degradation of the microstructure during operation.

Deformation mechanisms in a fine-grained Udimet 720LI nickel-base superalloy with high volume fractions of γ′ phases

Energy Technology Data Exchange (ETDEWEB)

Chen, Jiayu, E-mail: chenjiayu975@126.com; Dong, Jianxin; Zhang, Maicang; Yao, Zhihao

2016-09-15

Hot-deformation behaviors and mechanisms below γ′ solvus of U720LI with fine-grained microstructure and high volume fractions of γ′ phases were studied. MTS hot-compressed samples under hot-deformation parameters (Temperatures of 1040 °C, 1070 °C, 1100 °C, 1130 °C, strain rates of 0.01 s{sup −1}, 0.1 s{sup −1}, 0.5 s{sup −1} and strains of 0.11, 0.36, 0.69 and 1.2) were investigated by using multiple microstructural analysis methods, such as transmission electron microscopy (TEM), electron channeling contrast image (ECCI), et al.. Rare recovery and recrystallization were observed indicating that other deformation mechanisms might be enhanced during the deformation process. Except for the pinning effect, deformation happened within γ′ phases and also γ′ phase promoted the deformation of the matrix. When the slipping was inhibited by γ′ phases, twinning acted as a deformation mechanism in fine-grained U720LI. Due to the retardation effect of γ′ phases in the early stage of the deformation process, local grain boundary migration took effect. Once grain boundaries crossed γ′ phases, it made recrystallization by strain induced boundary motion(SIBM) easier.

3D High Resolution Mesh Deformation Based on Multi Library Wavelet Neural Network Architecture

Science.gov (United States)

Dhibi, Naziha; Elkefi, Akram; Bellil, Wajdi; Amar, Chokri Ben

2016-12-01

This paper deals with the features of a novel technique for large Laplacian boundary deformations using estimated rotations. The proposed method is based on a Multi Library Wavelet Neural Network structure founded on several mother wavelet families (MLWNN). The objective is to align features of mesh and minimize distortion with a fixed feature that minimizes the sum of the distances between all corresponding vertices. New mesh deformation method worked in the domain of Region of Interest (ROI). Our approach computes deformed ROI, updates and optimizes it to align features of mesh based on MLWNN and spherical parameterization configuration. This structure has the advantage of constructing the network by several mother wavelets to solve high dimensions problem using the best wavelet mother that models the signal better. The simulation test achieved the robustness and speed considerations when developing deformation methodologies. The Mean-Square Error and the ratio of deformation are low compared to other works from the state of the art. Our approach minimizes distortions with fixed features to have a well reconstructed object.

Deformation twinning: Influence of strain rate

Energy Technology Data Exchange (ETDEWEB)

Gray, G.T. III

1993-11-01

Twins in most crystal structures, including advanced materials such as intermetallics, form more readily as the temperature of deformation is decreased or the rate of deformation is increased. Both parameters lead to the suppression of thermally-activated dislocation processes which can result in stresses high enough to nucleate and grow deformation twins. Under high-strain rate or shock-loading/impact conditions deformation twinning is observed to be promoted even in high stacking fault energy FCC metals and alloys, composites, and ordered intermetallics which normally do not readily deform via twinning. Under such conditions and in particular under the extreme loading rates typical of shock wave deformation the competition between slip and deformation twinning can be examined in detail. In this paper, examples of deformation twinning in the intermetallics TiAl, Ti-48Al-lV and Ni{sub 3}A as well in the cermet Al-B{sub 4}C as a function of strain rate will be presented. Discussion includes: (1) the microstructural and experimental variables influencing twin formation in these systems and twinning topics related to high-strain-rate loading, (2) the high velocity of twin formation, and (3) the influence of deformation twinning on the constitutive response of advanced materials.

High spin states and the competition of spherical and strongly deformed shapes in the A = 70 to 80 region

International Nuclear Information System (INIS)

Hamilton, J.H.; Ramayya, A.V.; Piercey, R.B.

1982-01-01

A wide variety of collective band structures are seen in Ge to Sr nuclei to make this an important new testing ground for nuclear models. These include bands built on coexisting and competing near-spherical and deformed shapes, γ vibrational bands and multiple positive and negative parity bands. Ground state bands in Ge and Kr but not 78 80 Sr are crossed at the 8 + to 12 + levels. Gaps in the Nilsson levels for both N and Z = 38 at large deformation lead to large ground state deformation in Kr and Sr around N = 38. The crossing of rotation aligned bands based on (g/sub 9/2/) 2 configuration are correlated with the ground state deformations. A second high spin crossing is seen in 74 Kr. Measured g factors in 68 Ge yield a two-quasineutron structure for the 8 2 + state. 30 references

A Comprehensive Analysis of the SRS-Schwab Adult Spinal Deformity Classification and Confounding Variables

DEFF Research Database (Denmark)

Hallager, Dennis Winge; Hansen, Lars Valentin; Dragsted, Casper Rokkjær

2016-01-01

STUDY DESIGN: Cross-sectional analyses on a consecutive, prospective cohort. OBJECTIVE: To evaluate the ability of the Scoliosis Research Society (SRS)-Schwab Adult Spinal Deformity Classification to group patients by widely used health-related quality-of-life (HRQOL) scores and examine possible...... to confounding. However, age group and aetiology had individual significant effects. CONCLUSION: The SRS-Schwab sagittal modifiers reliably grouped patients graded 0 versus + / +  + according to the most widely used HRQOL scores and the effects of increasing grade level on odds for worse ODI scores remained...... confounding variables. SUMMARY OF BACKGROUND DATA: The SRS-Schwab Adult Spinal Deformity Classification includes sagittal modifiers considered important for HRQOL and the clinical impact of the classification has been validated in patients from the International Spine Study Group database; however, equivocal...

NORA-2, a model for creep deformation and rupture of zircaloy at high temperatures

International Nuclear Information System (INIS)

Raff, S.; Meyder, R.

1983-01-01

A model has been developed to describe Zircaloy cladding behaviour under LOCA and small leak conditions within specified temperature range and strain rates. The deformation model consists of a strain rate equation with two components representing strain rate controlled contributions from different deformation mechanisms. Transition from one mechanism to the other produces the strain rate dependence of the stress exponent of steady state creep. During transient creep the change of creep mechanisms produces a flow softening behaviour which induces unstable creep. Together with a strain hardening model, the strain history can be described for low and high strain values. The influence of oxidation is taken into account by modelling hardening due to solid solution of oxygen, cracking of the brittle oxide and oxygen stabilised α-phase layers, and by an oxidation-induced creep component in steam atmosphere. The rupture criterion is based on a strain fraction rule whose variables are temperature, strain rate or applied stress, and oxygen content. (author)

The Trend Odds Model for Ordinal Data‡

Science.gov (United States)

Capuano, Ana W.; Dawson, Jeffrey D.

2013-01-01

Ordinal data appear in a wide variety of scientific fields. These data are often analyzed using ordinal logistic regression models that assume proportional odds. When this assumption is not met, it may be possible to capture the lack of proportionality using a constrained structural relationship between the odds and the cut-points of the ordinal values (Peterson and Harrell, 1990). We consider a trend odds version of this constrained model, where the odds parameter increases or decreases in a monotonic manner across the cut-points. We demonstrate algebraically and graphically how this model is related to latent logistic, normal, and exponential distributions. In particular, we find that scale changes in these potential latent distributions are consistent with the trend odds assumption, with the logistic and exponential distributions having odds that increase in a linear or nearly linear fashion. We show how to fit this model using SAS Proc Nlmixed, and perform simulations under proportional odds and trend odds processes. We find that the added complexity of the trend odds model gives improved power over the proportional odds model when there are moderate to severe departures from proportionality. A hypothetical dataset is used to illustrate the interpretation of the trend odds model, and we apply this model to a Swine Influenza example where the proportional odds assumption appears to be violated. PMID:23225520

The trend odds model for ordinal data.

Science.gov (United States)

Capuano, Ana W; Dawson, Jeffrey D

2013-06-15

Ordinal data appear in a wide variety of scientific fields. These data are often analyzed using ordinal logistic regression models that assume proportional odds. When this assumption is not met, it may be possible to capture the lack of proportionality using a constrained structural relationship between the odds and the cut-points of the ordinal values. We consider a trend odds version of this constrained model, wherein the odds parameter increases or decreases in a monotonic manner across the cut-points. We demonstrate algebraically and graphically how this model is related to latent logistic, normal, and exponential distributions. In particular, we find that scale changes in these potential latent distributions are consistent with the trend odds assumption, with the logistic and exponential distributions having odds that increase in a linear or nearly linear fashion. We show how to fit this model using SAS Proc NLMIXED and perform simulations under proportional odds and trend odds processes. We find that the added complexity of the trend odds model gives improved power over the proportional odds model when there are moderate to severe departures from proportionality. A hypothetical data set is used to illustrate the interpretation of the trend odds model, and we apply this model to a swine influenza example wherein the proportional odds assumption appears to be violated. Copyright © 2012 John Wiley & Sons, Ltd.

LOFT advanced control room operator diagnostic and display system (ODDS)

International Nuclear Information System (INIS)

Larsen, D.G.; Robb, T.C.

1980-01-01

The Loss-of-Fluid Test (LOFT) Reactor Facility in Idaho includes a highly instrumented nuclear reactor operated by the Department of Energy for the purpose of establishing nuclear safety requirements. The results of the development and installation into LOFT of an Operator Diagnostic and Display System (ODDS) are presented. The ODDS is a computer-based graphics display system centered around a PRIME 550 computer with several RAMTEK color graphic display units located within the control room and available to the reactor operators. Use of computer-based color graphics to aid the reactor operator is discussed. A detailed hardware description of the LOFT data system and the ODDS is presented. Methods and problems of backfitting the ODDS equipment into the LOFT plant are discussed

Deformation twinning in a creep-deformed nanolaminate structure

International Nuclear Information System (INIS)

Hsiung, Luke L

2010-01-01

The underlying mechanism of deformation twinning occurring in a TiAl-(γ)/Ti 3 Al-(α 2 ) nanolaminate creep deformed at elevated temperatures has been studied. Since the multiplication and propagation of lattice dislocations in both γ and α 2 thin lamellae are very limited, the total flow of lattice dislocations becomes insufficient to accommodate the accumulated creep strains. Consequently, the movement of interfacial dislocations along the laminate interfaces, i.e., interface sliding, becomes an alternative deformation mode of the nanolaminate structure. Pile-ups of interfacial dislocations occur when interfacial ledges and impinged lattice dislocations act as obstacles to impede the movement of interfacial dislocations. Deformation twinning can accordingly take place to relieve a stress concentration resulting from the pile-up of interfacial dislocations. An interface-controlled twinning mechanism driven by the pile-up and dissociation of interfacial dislocations is accordingly proposed.

Deformation twinning in a creep-deformed nanolaminate structure

Science.gov (United States)

Hsiung, Luke L.

2010-10-01

The underlying mechanism of deformation twinning occurring in a TiAl-(γ)/Ti3Al-(α2) nanolaminate creep deformed at elevated temperatures has been studied. Since the multiplication and propagation of lattice dislocations in both γ and α2 thin lamellae are very limited, the total flow of lattice dislocations becomes insufficient to accommodate the accumulated creep strains. Consequently, the movement of interfacial dislocations along the laminate interfaces, i.e., interface sliding, becomes an alternative deformation mode of the nanolaminate structure. Pile-ups of interfacial dislocations occur when interfacial ledges and impinged lattice dislocations act as obstacles to impede the movement of interfacial dislocations. Deformation twinning can accordingly take place to relieve a stress concentration resulting from the pile-up of interfacial dislocations. An interface-controlled twinning mechanism driven by the pile-up and dissociation of interfacial dislocations is accordingly proposed.

Mechanism for microstructural evolution induced by high temperature deformation in Zr-based bulk metallic glasses

International Nuclear Information System (INIS)

Cheng, Sirui; Wang, Chunju; Ma, Mingzhen; Shan, Debin; Guo, Bin

2016-01-01

In the Zr_4_1_._2Ti_1_3_._8Cu_1_2_._5Ni_1_0Be_2_2_._5 (Vit1) alloy undergoing high temperature deformation, its thermal properties and microstructure are quite different from those in the annealing alloy. In order to research the coupled effect of temperature and plastic strain on microstructural evolution of Zr-based amorphous, uniaxial compression test of Vit1 alloy with good amorphous nature has been performed, and then the structural state and thermal properties of Vit1 alloy after thermal deformation and isothermal annealing in the supercooled liquid region were investigated. It is revealed that the deformed specimens possess higher characteristic temperature and lower enthalpy change of microstructural relaxation. In addition, the smaller inter-atomic distance and higher order degree of atomic arrangement can be observed in those deformed Vit1 alloy. That can be deduced that thermal deformation is in favor of the microstructural evolution from a metastable amorphous state to stable crystallization state, because plastic strain promotes the annihilation of free volume and provide excess driving force of atomic diffusion. However, upon increasing the ambient temperature, the influence of plastic deformation on microstructure gradually decreased owing to the decreasing proportion of the plastic deformation-induced annihilation of free volume during the whole thermal deformation process. - Highlights: • The deformed specimens possess closer microstructure and higher characteristic temperatures. • The order degree of microstructures in deformed specimens is higher than that in annealed specimens. • Thermal deformation accelerates the microstructural evolution of Zr-based BMGs. • The influence of thermal deformation on microstructure decreases with the temperature increasing.

Mechanism for microstructural evolution induced by high temperature deformation in Zr-based bulk metallic glasses

Energy Technology Data Exchange (ETDEWEB)

Cheng, Sirui [School of Materials Science and Engineering, Harbin Institute of Technology, Harbin 150001 (China); Wang, Chunju [Key Laboratory of Micro-Systems and Micro-Structures Manufacturing, Ministry of Education, Harbin Institute of Technology, Harbin 150080 (China); School of Materials Science and Engineering, Harbin Institute of Technology, Harbin 150001 (China); Ma, Mingzhen [State Key Laboratory of Metastable Materials Science and Technology, Yanshan University, Qinhuangdao 066004 (China); Shan, Debin, E-mail: shandebin@hit.edu.cn [State Key Laboratory of Advanced Welding and Joining, Harbin Institute of Technology, Harbin 150001 (China); Key Laboratory of Micro-Systems and Micro-Structures Manufacturing, Ministry of Education, Harbin Institute of Technology, Harbin 150080 (China); School of Materials Science and Engineering, Harbin Institute of Technology, Harbin 150001 (China); Guo, Bin [School of Materials Science and Engineering, Harbin Institute of Technology, Harbin 150001 (China)

2016-08-15

In the Zr{sub 41.2}Ti{sub 13.8}Cu{sub 12.5}Ni{sub 10}Be{sub 22.5} (Vit1) alloy undergoing high temperature deformation, its thermal properties and microstructure are quite different from those in the annealing alloy. In order to research the coupled effect of temperature and plastic strain on microstructural evolution of Zr-based amorphous, uniaxial compression test of Vit1 alloy with good amorphous nature has been performed, and then the structural state and thermal properties of Vit1 alloy after thermal deformation and isothermal annealing in the supercooled liquid region were investigated. It is revealed that the deformed specimens possess higher characteristic temperature and lower enthalpy change of microstructural relaxation. In addition, the smaller inter-atomic distance and higher order degree of atomic arrangement can be observed in those deformed Vit1 alloy. That can be deduced that thermal deformation is in favor of the microstructural evolution from a metastable amorphous state to stable crystallization state, because plastic strain promotes the annihilation of free volume and provide excess driving force of atomic diffusion. However, upon increasing the ambient temperature, the influence of plastic deformation on microstructure gradually decreased owing to the decreasing proportion of the plastic deformation-induced annihilation of free volume during the whole thermal deformation process. - Highlights: • The deformed specimens possess closer microstructure and higher characteristic temperatures. • The order degree of microstructures in deformed specimens is higher than that in annealed specimens. • Thermal deformation accelerates the microstructural evolution of Zr-based BMGs. • The influence of thermal deformation on microstructure decreases with the temperature increasing.

Effect of microplastic deformation on the electron ultrasonic absorption in high-purity molybdenum monocrystals

Energy Technology Data Exchange (ETDEWEB)

Pal' -Val' , P.P.; Kaufmann, Kh.J.

1983-03-01

The low temperature (100-6 K) linear absorption of ultrasound (88 kHz) by high purity molybdenum single crystals have been studied. Both unstrained samples and samples sub ected to microplastic deformation (epsilon<=0.45%) were used. Unstrained samples displayed at T<30 K a rapid increase in the absorption with lowering temperature which is interpreted as an indication of electron viscosity due to electron-phonon collisions. After deformation this part of absorption disappeared. This seems to suggest that microplastic deformation brings about in the crystal a sufficiently large number of defects that can compete with phonons in restricting the electron mean free path. A low temperature dynamic annealing has been revealed in strained samples, that is almost complete recovery of the absorption nature under irradiation with high amplitude sound, epsilon/sub 0/ approximately 10/sup -4/, during 10 min, at 6 K. A new relaxation peak of absorption at 10 K has been found in strained samples.

Effect of microplastic deformation on the electron ultrasonic absorption in high-purity molybdenum monocrystals

Energy Technology Data Exchange (ETDEWEB)

Pal' -Val' , P.P. (AN Ukrainskoj SSR, Kharkov. Fiziko-Tekhnicheskij Inst. Nizkikh Temperatur); Kaufmann, Kh.J. (Akademie der Wissenschaften der DDR, Berlin)

1983-03-01

The low temperature (100-6 K) linear absorption of ultrasound (88 kHz) by high purity molybdenum single crystals have been studied. Both unstrained samples and samples subjected to microplastic deformation (epsilon<=0.45%) were used. Unstrained samples displayed at T<30 K a rapid increase in the absorption with lowering temperature which is interpreted as an indication of electron viscosity due to electron-phonon collisions. After deformation this part of absorption disappeared. This seems to suggest that microplastic deformation brings about in the crystal a sufficiently large number of defects that can compete with phonons in restricting the electron mean free path. A low temperature ''dynamic annealing'' has been revealed in strained samples, that is, almost complete recovery of the absorption nature under irradiation with high amplitude sound, epsilon/sub 0/ approximately 10/sup -4/, during 10 min, at 6 K. A new relaxation peak of absorption at 10 K has been found in strained samples.

Anomalous signature splitting of the πh11/2direct x νi13/2 band in A-160 odd-odd nuclei

International Nuclear Information System (INIS)

Yang Chunxiang; Zhou Hongyu

2003-01-01

Systematic features of anomalous signature splitting of the πh 11/2 direct x νi 13/2 band in A-160 odd-odd nuclei have been investigated. It is shown that the mechanism of anomalous signature splitting is similar to that of the normal signature splitting which is essentially caused by the Coriolis mixing of Ω=1/2 components into the nuclear wavefunction and the anomalous splitting in signature is mainly caused by the definition. The extensively observed anomalous signature splitting in this band might be an indication that the interaction between the h 11/2 proton and the i 13/2 neutron cannot be neglected. The new observation of high- and low-K bands based on the same πh 11/2 direct x νi 13/2 configuration in 164 Tm is also discussed

Towards high velocity deformation characterisation of metals and composites using Digital Image Correlation

DEFF Research Database (Denmark)

Eriksen, Rasmus Normann Wilken; Berggreen, Christian; Boyd, S.W

2010-01-01

images and then extracting deformation data using Digital Image Correlation (DIC) from tensile testing in the intermediate strain rate regime available with the test machines. Three different materials, aluminium alloy 1050, S235 steel and glass fibre reinforced plastic (GFRP) were tested at different......Characterisation of materials subject to high velocity deformation is necessary as many materials behave differently under such conditions. It is particularly important for accurate numerical simulation of high strain rate events. High velocity servo-hydraulic test machines have enabled material...... testing in the strain rate regime from 1 – 500 ε/s. The range is much lower than that experienced under ballistic, shock or impact loads, nevertheless it is a useful starting point for the application of optical techniques. The present study examines the possibility of using high speed cameras to capture...

THE CHANGE IN DEFORMATION CHARACTERISTICS OF CONCRETE MONOLITHIC HIGH-RISE BUILDINGS

Directory of Open Access Journals (Sweden)

V. V. Punahin

2009-03-01

Full Text Available In the article results of studies of deformation features of concrete on actuate cement for monolithic high-altitude buildings are presented. It is shown that in construction of the high-altitude monolithic buildings in a summer period of a year one should take into account the character of changing the concrete elasticity and plasticity in time, which differs from the same indices for the concrete of normal hardening.

The High Strain Rate Deformation Behavior of High Purity Magnesium and AZ31B Magnesium Alloy

Science.gov (United States)

Livescu, Veronica; Cady, Carl M.; Cerreta, Ellen K.; Henrie, Benjamin L.; Gray, George T.

The deformation in compression of pure magnesium and AZ31B magnesium alloy, both with a strong basal pole texture, has been investigated as a function of temperature, strain rate, and specimen orientation. The mechanical response of both metals is highly dependent upon the orientation of loading direction with respect to the basal pole. Specimens compressed along the basal pole direction have a high sensitivity to strain rate and temperature and display a concave down work hardening behavior. Specimens loaded perpendicularly to the basal pole have a yield stress that is relatively insensitive to strain rate and temperature and a work hardening behavior that is parabolic and then linearly upwards. Both specimen orientations display a mechanical response that is sensitive to temperature and strain rate. Post mortem characterization of the pure magnesium was conducted on a subset of specimens to determine the microstructural and textural evolution during deformation and these results are correlated with the observed work hardening behavior and strain rate sensitivities were calculated.

Evaluation of Dynamic Deformation Behaviors in Metallic Materials under High Strain-Rates Using Taylor Bar Impact Test

Energy Technology Data Exchange (ETDEWEB)

Bae, Kyung Oh; Shin, Hyung Seop [Andong National Univ., Andong (Korea, Republic of)

2016-09-15

To ensure the reliability and safety of various mechanical systems in accordance with their high-speed usage, it is necessary to evaluate the dynamic deformation behavior of structural materials under impact load. However, it is not easy to understand the dynamic deformation behavior of the structural materials using experimental methods in the high strain-rate range exceeding 10{sup 4} s{sup -1}. In this study, the Taylor bar impact test was conducted to investigate the dynamic deformation behavior of metallic materials in the high strain-rate region, using a high-speed photography system. Numerical analysis of the Taylor bar impact test was performed using AUTODYN S/W. The results of the analysis were compared with the experimental results, and the material behavior in the high strain-rate region was discussed.

Recrystallization textures and microstructures of Al-0.3%Cu alloy after deformation to high strains

DEFF Research Database (Denmark)

Li, X.R.; Wakeel, A.; Huang, T.L.

2015-01-01

An Al-0.3%Cu alloy was deformed to high strains by cold rolling. The as-deformed samples were annealed at different temperatures until complete recrystallization. The cold rolling textures were determined by X-ray diffraction while the recrystallization textures and microstructures were...

Extremely deformable structures

CERN Document Server

2015-01-01

Recently, a new research stimulus has derived from the observation that soft structures, such as biological systems, but also rubber and gel, may work in a post critical regime, where elastic elements are subject to extreme deformations, though still exhibiting excellent mechanical performances. This is the realm of ‘extreme mechanics’, to which this book is addressed. The possibility of exploiting highly deformable structures opens new and unexpected technological possibilities. In particular, the challenge is the design of deformable and bi-stable mechanisms which can reach superior mechanical performances and can have a strong impact on several high-tech applications, including stretchable electronics, nanotube serpentines, deployable structures for aerospace engineering, cable deployment in the ocean, but also sensors and flexible actuators and vibration absorbers. Readers are introduced to a variety of interrelated topics involving the mechanics of extremely deformable structures, with emphasis on ...

Transient deformational properties of high temperature alloys used in solid oxide fuel cell stacks

DEFF Research Database (Denmark)

Tadesse Molla, Tesfaye; Kwok, Kawai; Frandsen, Henrik Lund

2017-01-01

Stresses and probability of failure during operation of solid oxide fuel cells (SOFCs) is affected by the deformational properties of the different components of the SOFC stack. Though the overall stress relaxes with time during steady state operation, large stresses would normally appear through...... to describe the high temperature inelastic deformational behaviors of Crofer 22 APU used for metallic interconnects in SOFC stacks.......Stresses and probability of failure during operation of solid oxide fuel cells (SOFCs) is affected by the deformational properties of the different components of the SOFC stack. Though the overall stress relaxes with time during steady state operation, large stresses would normally appear through...... transients in operation including temporary shut downs. These stresses are highly affected by the transient creep behavior of metallic components in the SOFC stack. This study investigates whether a variation of the so-called Chaboche's unified power law together with isotropic hardening can represent...

Deformation and degradation of polymers in ultra-high-pressure liquid chromatography.

Science.gov (United States)

Uliyanchenko, Elena; van der Wal, Sjoerd; Schoenmakers, Peter J

2011-09-28

Ultra-high-pressure liquid chromatography (UHPLC) using columns packed with sub-2 μm particles has great potential for separations of many types of complex samples, including polymers. However, the application of UHPLC for the analysis of polymers meets some fundamental obstacles. Small particles and narrow bore tubing in combination with high pressures generate significant shear and extensional forces in UHPLC systems, which may affect polymer chains. At high stress conditions flexible macromolecules may become extended and eventually the chemical bonds in the molecules can break. Deformation and degradation of macromolecules will affect the peak retention and the peak shape in the chromatogram, which may cause errors in the obtained results (e.g. the calculated molecular-weight distributions). In the present work we explored the limitations of UHPLC for the analysis of polymers. Degradation and deformation of macromolecules were studied by collecting and re-injecting polymer peaks and by off-line two-dimensional liquid chromatography. Polystyrene standards with molecular weight of 4 MDa and larger were found to degrade at UHPLC conditions. However, for most polymers degradation could be avoided by using low linear velocities. No degradation of 3-MDa PS (and smaller) was observed at linear velocities up to 7 mm/s. The column frits were implicated as the main sources of polymer degradation. The extent of degradation was found to depend on the type of the column and on the column history. At high flow rates degradation was observed without a column being installed. We demonstrated that polymer deformation preceded degradation. Stretched polymers eluted from the column in slalom chromatography mode (elution order opposite to that in SEC or HDC). Under certain conditions we observed co-elution of large and small PS molecules though a convolution of slalom chromatography and hydrodynamic chromatography. Copyright © 2011 Elsevier B.V. All rights reserved.

The multiphonon method as a dynamical approach to octupole correlations in deformed nuclei

International Nuclear Information System (INIS)

Piepenbring, R.

1986-09-01

The octupole correlations in nuclei are studied within the framework of the multiphonon method which is mainly the exact diagonalization of the total Hamiltonian in the space spanned by collective phonons. This treatment takes properly into account the Pauli principle. It is a microscopic approach based on a reflection symmetry of the potential. The spectroscopic properties of double even and odd-mass nuclei are nicely reproduced. The multiphonon method appears as a dynamical approach to octupole correlations in nuclei which can be compared to other models based on stable octupole deformation. 66 refs

Non-Deforming, High-Reflectance X-ray Coatings for Lynx and Other Future Missions

Science.gov (United States)

Windt, David

The overarching challenge addressed by this proposal is the development of highreflectance, high-resolution X-ray mirrors, to be used for the construction of lightweight X-ray telescopes for future NASA astronomy missions such as Lynx and others. The proposal's two specific aims are: 1) the development of optimized iridium-based interference coatings for the 0.1–10 keV band; and 2) the development of methods to mitigate coating-stress-induced substrate deformations in thin-shell glass and Si mirror segments. These goals will be achieved by building on established film deposition techniques and metrology infrastructure for X-ray optics that have been developed and advanced by the PI through APRA funding since 1999. Specific Aim #1: Interference Coatings for the 0.1–10 keV Energy Band Telescope effective area can be maximized by using Ir-based reflective coatings that exploit optical interference to provide higher reflectance than Ir alone. However, only preliminary investigations of such coatings have been conducted thus far; more research is required to fully optimize these coatings for maximum performance, to experimentally determine the coating designs that are feasible, and to determine the achievable X-ray reflectance, film stress, surface roughness, and thermal and temporal stability. The first specific aim of this proposal is to reach these very goals through a comprehensive research program. Demonstration of the achievable reflectance, stress, and roughness in stable, optimized coatings will in turn facilitate global telescope design optimization, by identifying the best coating for each mirror shell based on incidence angle, and on telescope effective-area and field-of-view requirements. The research has the potential to greatly increase the effective area of future X-ray telescopes. Specific Aim #2: Mitigation of Coating-Stress-Induced Substrate Deformations High-quality films of Ir and other candidate materials (e.g., B4C) to be investigated for the 0

Deformation of high performance concrete plate under humid tropical weather

Science.gov (United States)

Niken, C.; Elly, T.; Supartono, FX; Laksmi, I.

2018-03-01

This paper presents the relationship between surrounding relative humidity and temperature on deformation behavior of one sample concrete plate with compressive strength of 60MPa. This research was done in Indonesia that is in humid tropical weather. A specimens measuring 3000 mm × 1600 mm × 150 mm were used. The behavior was obtained by using four embedded vibrating wire strain gauges (VWESG). As a result there is a very strong relationship between humidity and deformation at the age range of 7 until 21 days. The largest deformation occurs in the corner and the fluctuation of deformation in side position is larger than in the corner and in the middle. The peaks of surrounding relative humidity were fully followed by the deepest valley of deformation on time in the corner, while in another position the range delay time was 8 - 11 hours. There is a strong relationship between surrounding temperature and deformation at the range of 7 until 14 days. The influenced of surrounding relative humidity to concrete behavior is faster and longer than surrounding temperature. The influence of surrounding temperature in humid tropical weather was shorter than in non-humid tropical weather.

Identical bands at normal deformation: Necessity of going beyond the mean-field approach

International Nuclear Information System (INIS)

Sun, Y.; Wu, C.; Feng, D.H.; Egido, J.L.; Guidry, M.

1996-01-01

The validity of BCS theory has been questioned because the appearance of normally deformed identical bands in odd and even nuclei seems to contradict the conventional understanding of the blocking effect. This problem is examined with the projected shell model (PSM), which projects good angular momentum states and includes many-body correlations in both deformation and pairing channels. Satisfactory reproduction of identical band data by the PSM suggests that it may be necessary to go beyond the mean field to obtain a quantitative account of identical bands. copyright 1996 The American Physical Society

Analysis of High Temperature Deformed Structure and Dynamic Precipitation in W9Mo3Cr4V Steel

Institute of Scientific and Technical Information of China (English)

无

2001-01-01

With TEM、SEM, various high-temperature deformed structures inW9Mo3Cr4V steel were investigated. The sub-structures，recrystallized nuclei, as well as the dynamic precipitation were also studied and analyzed. The relationship between recrystallized structures and dynamic precipitation was discussed. The results showed that the deformed structures in W9Mo3Cr4V steel are more complicated than those in low alloy steels. Because W9Mo3Cr4V steel is a high-speed steel, there are a large number of residual carbides on the matrix. Also, much dynamic precipitating carbides will precipitate during deformation at high temperature.

Quartetting in even-even and odd-odd N=Z nuclei

Science.gov (United States)

Sambataro, M.; Sandulescu, N.

2018-02-01

We report on a microscopic description of even-even N = Z nuclei in a formalism of quartets. Quartets are four-body correlated structures characterized by isospin T and angular momentum J. We show that the ground state correlations induced by a realistic shell model interaction can be well accounted for in terms of a restricted set of T = 0 low-J quartets, the J = 0 one playing by far a leading role among them. A conceptually similar description of odd-odd self-conjugate nuclei is given in terms of two distinct families of building blocks, one formed by the same T = 0 quartets employed for the even-even systems and the other by collective pairs with either T = 0 or T = 1. Some applications of this formalism are discussed for nuclei in the sd shell.

High-rate deformation and fracture of steel 09G2S

Science.gov (United States)

Balandin, Vl. Vas.; Balandin, Vl. Vl.; Bragov, A. M.; Igumnov, L. A.; Konstantinov, A. Yu.; Lomunov, A. K.

2014-11-01

The results of experimental and theoretical studies of steel 09G2S deformation and fracture laws in a wide range of strain rates and temperature variations are given. The dynamic deformation curves and the ultimate characteristics of plasticity in high-rate strain were determined by the Kolsky method in compression, extension, and shear tests. The elastoplastic properties and spall strength were studied by using the gaseous gun of calibre 57 mm and the interferometer VISAR according to the plane-wave experiment technique. The data obtained by the Kolsky method were used to determine the parameters of the Johnson-Cook model which, in the framework of the theory of flow, describes how the yield surface radius depends on the strain, strain rate, and temperature.

Variation of low temperature internal friction of microplastic deformation of high purity molybdenum single crystals

International Nuclear Information System (INIS)

Pal-Val, P.P.; Kaufmann, H.J.

1984-01-01

Amplitude and temperature spectra of ultrasound absorption in weakly deformed high purity molybdenum single crystals of different orientations were measured. The results were discussed in terms of parameter changes related to quasiparticle or dislocation oscillations, respectively, dislocation point defect interactions as well as defect generation at microplastic deformation. (author)

Variation of low temperature internal friction of microplastic deformation of high purity molybdenum single crystals

Energy Technology Data Exchange (ETDEWEB)

Pal-Val, P.P. (AN Ukrainskoj SSR, Kharkov. Fiziko-Tekhnicheskij Inst. Nizkikh Temperatur); Kaufmann, H.J. (Akademie der Wissenschaften der DDR, Berlin)

1984-08-01

Amplitude and temperature spectra of ultrasound absorption in weakly deformed high purity molybdenum single crystals of different orientations were measured. The results were discussed in terms of parameter changes related to quasiparticle or dislocation oscillations, respectively, dislocation point defect interactions as well as defect generation at microplastic deformation.

Boson and fermion degrees of freedom in the orthosymplectic extension of the IVBM: Odd-odd nuclear spectra

International Nuclear Information System (INIS)

Ganev, H. G.; Georgieva, A. I.

2008-01-01

The dynamical symmetry group Sp(12, R) of the Interacting Vector Boson Model (IVBM) is extended to the orthosymplectic group OSp(2Ω/12, R) in order to incorporate fermion degrees of freedom. The structure of even-even nuclei is used as a core on which the collective excitations of the neighboring odd-mass and odd-odd nuclei are build on. Hence, the spectra of odd-mass and odd-odd nuclei arise as a result of the coupling of the fermion degrees of freedom, specified by the fermion sector SOF (2Ω) to the boson core, whose states belong to an Sp(12, R) irreducible representation. The orthosymplectic dynamical symmetry is applied for the simultaneous description of the spectra of some neighboring nuclei from rare earth region. The theoretical predictions for different low-lying collective bands with positive and negative parity are compared with the experiment. The obtained results reveal the applicability of the model and its boson-fermion extension.

A deformation of Sasakian structure in the presence of torsion and supergravity solutions

International Nuclear Information System (INIS)

Houri, Tsuyoshi; Takeuchi, Hiroshi; Yasui, Yukinori

2013-01-01

A deformation of Sasakian structure in the presence of totally skew-symmetric torsion is discussed on odd-dimensional manifolds whose metric cones are Kähler with torsion. It is shown that such a geometry inherits similar properties to those of Sasakian geometry. As their example, we present an explicit expression of local metrics. It is also demonstrated that our example of the metrics admits the existence of hidden symmetry described by non-trivial odd-rank generalized closed conformal Killing–Yano tensors. Furthermore, using these metrics as an ansatz, we construct exact solutions in five-dimensional minimal gauged/ungauged supergravity and 11-dimensional supergravity. Finally, the global structures of the solutions are discussed. We obtain regular metrics on compact manifolds in five dimensions, which give natural generalizations of Sasaki–Einstein manifolds Y p,q and L a,b,c . We also briefly discuss regular metrics on non-compact manifolds in 11 dimensions. (paper)

Low-temperature internal friction in high-purity monocrystalline and impure polycrystalline niobium after plastic deformation

International Nuclear Information System (INIS)

Wasserbaech, W.; Thompson, E.

2001-01-01

The internal friction Q -1 of plastically deformed, high-purity monocrystalline and impure polycrystalline niobium specimens was measured in the temperature range between 65 mK and about 2 K. Plastic deformation has a pronounced effect on the internal friction Q -1 of the high-purity monocrystalline specimens, and the effect has been found to be almost temperature independent. By contrast, surprisingly, the internal friction Q -1 of the impure polycrystalline specimens was found to be almost independent of the extent of plastic deformation. Comparison of the experimental results with different models of a dynamic scattering of acoustic phonons by dislocations leads to the conclusion that the results cannot be explained with the two-level tunneling model. Instead it is suggested that a strong interaction between acoustic phonons and geometrical kinks in non-screw dislocations is responsible for the observed internal friction Q -1 . (orig.)

Large poroelastic deformation of a soft material

Science.gov (United States)

MacMinn, Christopher W.; Dufresne, Eric R.; Wettlaufer, John S.

2014-11-01

Flow through a porous material will drive mechanical deformation when the fluid pressure becomes comparable to the stiffness of the solid skeleton. This has applications ranging from hydraulic fracture for recovery of shale gas, where fluid is injected at high pressure, to the mechanics of biological cells and tissues, where the solid skeleton is very soft. The traditional linear theory of poroelasticity captures this fluid-solid coupling by combining Darcy's law with linear elasticity. However, linear elasticity is only volume-conservative to first order in the strain, which can become problematic when damage, plasticity, or extreme softness lead to large deformations. Here, we compare the predictions of linear poroelasticity with those of a large-deformation framework in the context of two model problems. We show that errors in volume conservation are compounded and amplified by coupling with the fluid flow, and can become important even when the deformation is small. We also illustrate these results with a laboratory experiment.

G-phase precipitation in austenitic stainless steel deformed by high pressure torsion

International Nuclear Information System (INIS)

Shuro, I.; Kuo, H.H.; Sasaki, T.; Hono, K.; Todaka, Y.; Umemoto, M.

2012-01-01

Highlights: ► Using TEM and APT analyses, G-phase precipitation was observed in HPTed SUS304 with no trace of spinodal decomposition. ► G-phase precipitation occurred much shorter time than previous studies probably due to the elimination of prior SD and enhanced diffusion by severe plastic deformation. ► G-phase composition is a function of aging time. ► Tensile tests showed that in SUS304 embrittlement occurs solely due to G-phase precipitation. - Abstract: G phase an intermetallic silicide has been observed in martensite of precipitation hardened stainless steels and in the ferrite of dual (austenite and ferrite) phase stainless steels. In both cases, before G-phase precipitates, the matrix composition changes due to spinodal decomposition and solute partitioning between ferrite and austenite. Thus in the present study, single bcc phase and high Ni content stainless steel, was selected to study G-phase precipitation expecting elimination of the interference from spinodal decomposition and solute partitioning. Fe–18Cr–8Ni (SUS304) austenitic stainless steel samples were deformed at room temperature by high pressure torsion to obtain 100% volume fraction of deformation induced martensite (α′). HPT deformation was chosen due to its ability to induce high strength by grain refinement and also attain 100% α′ at room temperature. After annealing at 400 °C for 500 h, G-phase precipitation was observed in the fully martensitic matrix without spinodal decomposition. Crystallographic analysis of annealed samples using high resolution transmission electron microscopy (HRTEM) and energy dispersive spectroscopy (EDS) detected a Mn–Ni–Si rich G-phase with fcc crystal structure with lattice parameter of 1.16 nm. The value of lattice parameter corresponds well with previously reported values. Chemical analysis by atom probe tomography (APT) showed G-phase of composition Mn 21 Ni 50 Si 24 Fe 4 Cr. Tensile tests showed that G-phase precipitation leads to

G-phase precipitation in austenitic stainless steel deformed by high pressure torsion

Energy Technology Data Exchange (ETDEWEB)

Shuro, I., E-mail: innoshuro@martens.me.tut.ac.jp [Functional Materials Engineering, Toyohashi University of Technology, 1-1, Toyohashi, Aichi 441-8580 (Japan); Kuo, H.H. [Functional Materials Engineering, Toyohashi University of Technology, 1-1, Toyohashi, Aichi 441-8580 (Japan); Sasaki, T.; Hono, K. [National Institute for Materials Sciences, Sengen 1-2-1, Tsukuba 305-0047 (Japan); Todaka, Y.; Umemoto, M. [Functional Materials Engineering, Toyohashi University of Technology, 1-1, Toyohashi, Aichi 441-8580 (Japan)

2012-08-30

Highlights: Black-Right-Pointing-Pointer Using TEM and APT analyses, G-phase precipitation was observed in HPTed SUS304 with no trace of spinodal decomposition. Black-Right-Pointing-Pointer G-phase precipitation occurred much shorter time than previous studies probably due to the elimination of prior SD and enhanced diffusion by severe plastic deformation. Black-Right-Pointing-Pointer G-phase composition is a function of aging time. Black-Right-Pointing-Pointer Tensile tests showed that in SUS304 embrittlement occurs solely due to G-phase precipitation. - Abstract: G phase an intermetallic silicide has been observed in martensite of precipitation hardened stainless steels and in the ferrite of dual (austenite and ferrite) phase stainless steels. In both cases, before G-phase precipitates, the matrix composition changes due to spinodal decomposition and solute partitioning between ferrite and austenite. Thus in the present study, single bcc phase and high Ni content stainless steel, was selected to study G-phase precipitation expecting elimination of the interference from spinodal decomposition and solute partitioning. Fe-18Cr-8Ni (SUS304) austenitic stainless steel samples were deformed at room temperature by high pressure torsion to obtain 100% volume fraction of deformation induced martensite ({alpha} Prime ). HPT deformation was chosen due to its ability to induce high strength by grain refinement and also attain 100% {alpha} Prime at room temperature. After annealing at 400 Degree-Sign C for 500 h, G-phase precipitation was observed in the fully martensitic matrix without spinodal decomposition. Crystallographic analysis of annealed samples using high resolution transmission electron microscopy (HRTEM) and energy dispersive spectroscopy (EDS) detected a Mn-Ni-Si rich G-phase with fcc crystal structure with lattice parameter of 1.16 nm. The value of lattice parameter corresponds well with previously reported values. Chemical analysis by atom probe tomography

Effect of prior deformation on microstructural development and Laves phase precipitation in high-chromium stainless steel.

Science.gov (United States)

Hsiao, Z-W; Chen, D; Kuo, J-C; Lin, D-Y

2017-04-01

This study investigated the influence of deformation on precipitation behaviour and microstructure change during annealing. Here, the prior deformation of high-chromium stainless steel was tensile deformation of 3%, 6% and 10%, and the specimens were then annealed at 700˚C for 10 h. The specimens were subsequently analyzed using backscattered electron image and electron backscattering diffraction measurements with SEM. Compared with the deformation microstructure, the grains revealed no preferred orientation. The precipitates of TiN and NbC were formed homogenously in the grain interior and at grain boundaries after annealing. Fine Laves phase precipitates were observed in grains and along subgrain boundaries as the deformation increased. Furthermore, the volume fraction of Laves phase increased, but the average particle diameter of precipitate was reduced as the deformation increased. © 2017 The Authors Journal of Microscopy © 2017 Royal Microscopical Society.

Democracy against the odds

DEFF Research Database (Denmark)

Seeberg, Michael

Why have a number of poor countries sustained electoral democracy against the odds? The extant literature on democracy and democratization consistently points to the importance of socioeconomic development and democratic neighboring countries, in particular, as important prerequisites for a stable...... demonstrates the enormous potential of political parties and civil society in processes of democratization. ------------------------------------------------------------------- Hvorfor opretholder en række fattige lande en demokratisk styreform imod alle odds? Demokratiforskere forventer, at et land må have et...

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

International Nuclear Information System (INIS)

Li Bingheng; Lei Yi'an; Zhang Zhenhua

2013-01-01

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

Plastic deformation of Al13Fe4 particles in Al-Al13Fe4 by high-speed compression

International Nuclear Information System (INIS)

Yoneyama, N.; Mizoguchi, K.; Kumai, S.; Sato, A.; Kiritani, M.

2003-01-01

Spray-formed Al-Fe alloys having undergone high-speed deformation were examined under a high-voltage electron microscope. Two types of specimens were examined; one containing fine Al 13 Fe 4 particles, and the other containing large particles. In the former specimen, deformation is found to proceed in three patterns, depending on specimen thickness and strain rate: (1) without deformation of the Al 13 Fe 4 ; (2) breaking of the Al 13 Fe 4 ; or (3) melting of the Al 13 Fe 4 . Local melting is found to alter some of the Al 13 Fe 4 particles, to impart five-fold symmetry in diffraction or an amorphous structure. In the latter specimen, introduction of glide dislocations enabled us to determine a shear system in the mc102 monoclinic c2/m crystal of Al 13 Fe 4 . On the bases of these observations, the mechanism of high-speed deformation is discussed while taking into account the highly stressed and/or heated states of Al 13 Fe 4 embedded in Al matrix

Multiscale modeling of high contrast brinkman equations with applications to deformable porous media

KAUST Repository

Brown, Donald

2013-06-18

Simulating porous media flows has a wide range of applications. Often, these applications involve many scales and multi-physical processes. A useful tool in the analysis of such problems in that of homogenization as an averaged description is derived circumventing the need for complicated simulation of the fine scale features. In this work, we recall recent developments of homogenization techniques in the application of flows in deformable porous media. In addition, homogenization of media with high-contrast. In particular, we recall the main ideas of the homogenization of slowly varying Stokes flow and summarize the results of [4]. We also present the ideas for extending these techniques to high-contrast deformable media [3]. These ideas are connected by the modeling of multiscale fluid-structure interaction problems. © 2013 American Society of Civil Engineers.

TEMPERATURE-DEFORMATION CRITERION OF OPTIMIZATION OF FINE DRAWING HIGH CARBON WIRE ROUTE

Directory of Open Access Journals (Sweden)

Y. L. Bobarikin

2012-01-01

Full Text Available The temperature-deformation criterion of assessment and optimization of routes of the thin high-carbon wire drawing enabling to increase plastic properties of wire at retaining of its durability is offered.

A New High-Resolution Spectral Approach to Noninvasively Evaluate Wall Deformations in Arteries

Directory of Open Access Journals (Sweden)

Ivonne Bazan

2014-01-01

Full Text Available By locally measuring changes on arterial wall thickness as a function of pressure, the related Young modulus can be evaluated. This physical magnitude has shown to be an important predictive factor for cardiovascular diseases. For evaluating those changes, imaging segmentation or time correlations of ultrasonic echoes, coming from wall interfaces, are usually employed. In this paper, an alternative low-cost technique is proposed to locally evaluate variations on arterial walls, which are dynamically measured with an improved high-resolution calculation of power spectral densities in echo-traces of the wall interfaces, by using a parametric autoregressive processing. Certain wall deformations are finely detected by evaluating the echoes overtones peaks with power spectral estimations that implement Burg and Yule Walker algorithms. Results of this spectral approach are compared with a classical cross-correlation operator, in a tube phantom and “in vitro” carotid tissue. A circulating loop, mimicking heart periods and blood pressure changes, is employed to dynamically inspect each sample with a broadband ultrasonic probe, acquiring multiple A-Scans which are windowed to isolate echo-traces packets coming from distinct walls. Then the new technique and cross-correlation operator are applied to evaluate changing parietal deformations from the detection of displacements registered on the wall faces under periodic regime.

A New High-Resolution Spectral Approach to Noninvasively Evaluate Wall Deformations in Arteries

Science.gov (United States)

Bazan, Ivonne; Negreira, Carlos; Ramos, Antonio; Brum, Javier; Ramirez, Alfredo

2014-01-01

By locally measuring changes on arterial wall thickness as a function of pressure, the related Young modulus can be evaluated. This physical magnitude has shown to be an important predictive factor for cardiovascular diseases. For evaluating those changes, imaging segmentation or time correlations of ultrasonic echoes, coming from wall interfaces, are usually employed. In this paper, an alternative low-cost technique is proposed to locally evaluate variations on arterial walls, which are dynamically measured with an improved high-resolution calculation of power spectral densities in echo-traces of the wall interfaces, by using a parametric autoregressive processing. Certain wall deformations are finely detected by evaluating the echoes overtones peaks with power spectral estimations that implement Burg and Yule Walker algorithms. Results of this spectral approach are compared with a classical cross-correlation operator, in a tube phantom and “in vitro” carotid tissue. A circulating loop, mimicking heart periods and blood pressure changes, is employed to dynamically inspect each sample with a broadband ultrasonic probe, acquiring multiple A-Scans which are windowed to isolate echo-traces packets coming from distinct walls. Then the new technique and cross-correlation operator are applied to evaluate changing parietal deformations from the detection of displacements registered on the wall faces under periodic regime. PMID:24688596

Lack of motor prediction, rather than perceptual conflict, evokes an odd sensation upon stepping onto a stopped escalator

Science.gov (United States)

Gomi, Hiroaki; Sakurada, Takeshi; Fukui, Takao

2014-01-01

When stepping onto a stopped escalator, we often perceive an “odd sensation” that is never felt when stepping onto stairs. The sight of an escalator provides a strong contextual cue that, in expectation of the backward acceleration when stepping on, triggers an anticipatory forward postural adjustment driven by a habitual and implicit motor process. Here we contrast two theories about why this postural change leads to an odd sensation. The first theory links the odd sensation to a lack of sensorimotor prediction from all low-level implicit motor processes. The second theory links the odd sensation to the high-level conflict between the conscious awareness that the escalator is stopped and the implicit perception that evokes an endogenous motor program specific to a moving escalator. We show very similar postural changes can also arise from reflexive responses to visual stimuli, such as contracting/expanding optic flow fields, and that these reflexive responses produce similar odd sensations to the stopped escalator. We conclude that the high-level conflict is not necessary for such sensations. In contrast, the implicitly driven behavioral change itself essentially leads to the odd sensation in motor perception since the unintentional change may be less attributable to self-generated action because of a lack of motor predictions. PMID:24688460

In-situ high-P, T X-ray microtomographic imaging during large deformation

DEFF Research Database (Denmark)

Wang, Y; Lesher, Charles

2011-01-01

We have examined the microstructural evolution of a two-phase composite (olivine + Fe-Ni-S) during large shear deformation, using a newly developed high-pressure X-ray tomography microscope. Two samples were examined: a load-bearing framework–type texture, where the alloy phase (Fe-Ni-S) was pres...

A Bed-Deformation Experiment Beneath Engabreen, Norway

Science.gov (United States)

Iverson, N. R.; Hooyer, T. S.; Fischer, U. H.; Cohen, D.; Jackson, M.; Moore, P. L.; Lappegard, G.; Kohler, J.

2001-12-01

Although deformation of sediment beneath ice masses may contribute to their motion and may sometimes enable fast glacier flow, both the kinematics and mechanics of deformation are controversial. This controversy stems, in part, from subglacial measurements that are difficult to interpret. Measurements have been made either beneath ice margins or remotely through boreholes with interpretive limitations caused by uncertain instrument position and performance, uncertain sediment thickness and bed geometry, and unknown disturbance of the bed and stress state by drilling. We have used a different approach made possible by the Svartisen Subglacial Laboratory, which enables human access to the bed of Engabreen, Norway, beneath 230 m of temperate ice. A trough (2 m x 1.5 m x 0.4 m deep) was blasted in the rock bed and filled with sediment (75 percent sand and gravel, 20 percent silt, 5 percent clay). Instruments were placed in the sediment to record shear deformation (tiltmeters), dilation and contraction, total normal stress, and pore-water pressure. Pore pressure was manipulated by feeding water to the base of the sediment with a high-pressure pump, operated in a rock tunnel 4 m below the bed surface. After irregular deformation during closure of ice on the sediment, shear deformation and volume change stopped, and total normal stress became constant at 2.2 MPa. Subsequent pump tests, which lasted several hours, induced pore-water pressures greater than 70 percent of the total normal stress and resulted in shear deformation over most of the sediment thickness with attendant dilation. Ice separated from the sediment when effective normal stress was lowest, arresting shear deformation. Displacement profiles during pump tests were similar to those observed by Boulton and co-workers at Breidamerkurjökull, Iceland, with rates of shear strain increasing upward toward the glacier sole. Such deformation does not require viscous deformation resistance and is expected in a

Deformability measurement of red blood cells using a microfluidic channel array and an air cavity in a driving syringe with high throughput and precise detection of subpopulations.

Science.gov (United States)

Kang, Yang Jun; Ha, Young-Ran; Lee, Sang-Joon

2016-01-07

Red blood cell (RBC) deformability has been considered a potential biomarker for monitoring pathological disorders. High throughput and detection of subpopulations in RBCs are essential in the measurement of RBC deformability. In this paper, we propose a new method to measure RBC deformability by evaluating temporal variations in the average velocity of blood flow and image intensity of successively clogged RBCs in the microfluidic channel array for specific time durations. In addition, to effectively detect differences in subpopulations of RBCs, an air compliance effect is employed by adding an air cavity into a disposable syringe. The syringe was equally filled with a blood sample (V(blood) = 0.3 mL, hematocrit = 50%) and air (V(air) = 0.3 mL). Owing to the air compliance effect, blood flow in the microfluidic device behaved transiently depending on the fluidic resistance in the microfluidic device. Based on the transient behaviors of blood flows, the deformability of RBCs is quantified by evaluating three representative parameters, namely, minimum value of the average velocity of blood flow, clogging index, and delivered blood volume. The proposed method was applied to measure the deformability of blood samples consisting of homogeneous RBCs fixed with four different concentrations of glutaraldehyde solution (0%-0.23%). The proposed method was also employed to evaluate the deformability of blood samples partially mixed with normal RBCs and hardened RBCs. Thereafter, the deformability of RBCs infected by human malaria parasite Plasmodium falciparum was measured. As a result, the three parameters significantly varied, depending on the degree of deformability. In addition, the deformability measurement of blood samples was successfully completed in a short time (∼10 min). Therefore, the proposed method has significant potential in deformability measurement of blood samples containing hematological diseases with high throughput and precise detection of

Solute grain boundary segregation during high temperature plastic deformation in a Cr-Mo low alloy steel

International Nuclear Information System (INIS)

Chen, X.-M.; Song, S.-H.; Weng, L.-Q.; Liu, S.-J.

2011-01-01

Highlights: → The segregation of P and Mo is evidently enhanced by plastic deformation. → The boundary concentrations of P and Mo increase with increasing strain. → A model with consideration of site competition in grain boundary segregation in a ternary system is developed. → Model predictions show a reasonable agreement with the observations. - Abstract: Grain boundary segregation of Cr, Mo and P to austenite grain boundaries in a P-doped 1Cr0.5Mo steel is examined using field emission gun scanning transmission electron microscopy for the specimens undeformed and deformed by 10% with a strain rate of 2 x 10 -3 s -1 at 900 deg. C, and subsequently water quenched to room temperature. Before deformation, there is some segregation for Mo and P, but the segregation is considerably increased after deformation. The segregation of Cr is very small and there is no apparent difference between the undeformed and deformed specimens. Since the thermal equilibrium segregation has been attained prior to deformation, the segregation produced during deformation has a non-equilibrium characteristic. A theoretical model with consideration of site competition in grain boundary segregation between two solutes in a ternary alloy is developed to explain the experimental results. Model predictions are made, which show a reasonable agreement with the observations.

Linear odd Poisson bracket on Grassmann variables

International Nuclear Information System (INIS)

Soroka, V.A.

1999-01-01

A linear odd Poisson bracket (antibracket) realized solely in terms of Grassmann variables is suggested. It is revealed that the bracket, which corresponds to a semi-simple Lie group, has at once three Grassmann-odd nilpotent Δ-like differential operators of the first, the second and the third orders with respect to Grassmann derivatives, in contrast with the canonical odd Poisson bracket having the only Grassmann-odd nilpotent differential Δ-operator of the second order. It is shown that these Δ-like operators together with a Grassmann-odd nilpotent Casimir function of this bracket form a finite-dimensional Lie superalgebra. (Copyright (c) 1999 Elsevier Science B.V., Amsterdam. All rights reserved.)

Gamow-Teller transitions and proton-neutron pair correlation in N =Z odd-odd p -shell nuclei

Science.gov (United States)

Morita, Hiroyuki; Kanada-En'yo, Yoshiko

2017-10-01

We have studied the Gamow-Teller (GT) transitions from N =Z +2 neighbors to N =Z odd-odd nuclei in the p -shell region by using isospin-projected and β γ -constraint antisymmetrized molecular dynamics combined with the generator coordinate method. The calculated GT transition strengths from 0+1 states to 1+0 states such as 6He(01+1 ) →6Li(11+0 ) , 10Be(01+1 ) →10B(11+0 ) , and 14C(01+1 ) →14N(12+0 ) exhaust more than 50% of the sum rule. These N =Z +2 initial states and N =Z odd-odd final states are found to dominantly have S =0 ,T =1 n n pairs and S =1 ,T =0 p n pairs, respectively. Based on the two-nucleon (N N ) pair picture, we can understand the concentration of the GT strengths as the spin-isospin-flip transition n n (S =0 ,T =1 )→p n (S =1 ,T =0 ) in L S coupling. The GT transition can be a good probe to identify the spin-isospin partner states with n n pairs and p n pairs of N =Z +2 and N =Z odd-odd nuclei, respectively.

Why Some Schools with Latino Children Beat the Odds...and Others Don't

Science.gov (United States)

Waits, Mary Jo; Campbell, Heather E.; Gau, Rebecca; Jacobs, Ellen; Rex, Tom; Hess, Robert K.

2006-01-01

Throughout Arizona and the Southwest, the odds are against high achievement in schools with a mostly Latino, mostly poor student enrollment. Some schools, however, "beat the odds" and achieve consistently high results or show steady gains. Why do these schools succeed where others fail? Using the methodology of business guru Jim Collins…

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.

The Antarctic ozone minimum - Relationship to odd nitrogen, odd chlorine, the final warming, and the 11-year solar cycle

Science.gov (United States)

Callis, L. B.; Natarajan, M.

1986-01-01

Photochemical calculations along 'diabatic trajectories' in the meridional phase are used to search for the cause of the dramatic springtime minimum in Antarctic column ozone. The results indicate that the minimum is principally due to catalytic destruction of ozone by high levels of total odd nitrogen. Calculations suggest that these levels of odd nitrogen are transported within the polar vortex and during the polar night from the middle to upper stratosphere and lower mesosphere to the lower stratosphere. The possibility that these levels are related to the 11-year solar cycle and are increased by enhanced formation in the thermosphere and mesosphere during solar maximum conditions is discussed.

Bed-Deformation Experiments Beneath a Temperate Glacier

Science.gov (United States)

Iverson, N. R.; Hooyer, T. S.; Fischer, U. H.; Cohen, D.; Jackson, M.; Moore, P. L.; Lappegard, G.; Kohler, J.

2002-12-01

Fast flow of glaciers and genesis of glacial landforms are commonly attributed to shear deformation of subglacial sediment. Although models of this process abound, data gathered subglacially on the kinematics and mechanics of such deformation are difficult to interpret. Major difficulties stem from the necessity of either measuring deformation near glacier margins, where conditions may be abnormal, or at the bottoms of boreholes, where the scope of instrumentation is limited, drilling disturbs sediment, and local boundary conditions are poorly known. A different approach is possible at the Svartisen Subglacial Laboratory, where tunnels melted in the ice provide temporary human access to the bed of Engabreen, a temperate outlet glacier of the Svartisen Ice Cap in Norway. A trough (2 m x 1.5 m x 0.5 m deep) was blasted in the rock bed, where the glacier is 220 m thick and sliding at 0.1-0.2 m/d. During two spring field seasons, this trough was filled with 2.5 tons of simulated till. Instruments in the till recorded shear (tiltmeters), volume change, total normal stress, and pore-water pressure as ice moved across the till surface. Pore pressure was brought to near the total normal stress by feeding water to the base of the till with a high-pressure pump, operated in a rock tunnel 4 m below the bed surface. Results illustrate some fundamental aspects of bed deformation. Permanent shear deformation requires low effective normal stress and hence high pore-water pressure, owing to the frictional nature of till. Shear strain generally increases upward in the bed toward the glacier sole, consistent with previous measurements beneath thinner ice at glacier margins. At low effective normal stresses, ice sometimes decouples from underlying till. Overall, bed deformation accounts for 10-35 % of basal motion, although this range excludes shear in the uppermost 0.05 m of till where shear was not measured. Pump tests with durations ranging from seconds to hours highlight the need

High rate deformation of metallic liner and its dislocation description

International Nuclear Information System (INIS)

Prut, V.V.; Shybaev, S.A.

1996-01-01

The dynamics of deformation in cylindrical liners are studied experimentally and theoretically in Z-pinch geometry, where the cylinders are deformed by a magnetic field created by a current flowing along the axis. This method allows one to obtain one-dimensional deformation and a reliable recording of magnetic field and cylinder deformation. The experiments are performed with a current amplitude of 0.8-3 MA and a current rise time of 2.5-4 μs. Aluminium and copper tubes, from 4 to 6 mm in diameter and 0.25-1 mm wall thick, are compressed. The deformation rates under study are in the range of 10 5 -10 6 s -1 . The time dependence of the radii of the copper and aluminium tubes are measured with a streak camera and by the pulsed x-ray technique. The time resolution of the streak and x-ray photographs is 10-15 ns, their spatial resolution is 10-15 μm. A rheological model describing the dynamics of compression is developed. The model includes the description of the metal as a plastic medium with moving dislocations in the solid state, and as a viscous medium in the liquid state. The one-dimensional solution to magneto-hydrodynamical equations of the liner dynamics is compared with the experimental results and thus the following rheological parameters of the metal are obtained: β, the probability of dislocation generation in plastic deformation; and σ d , the drag stress, the parameter which characterizes a drag force acting on the dislocation. (Author)

Development of a deformation and failure model for Zircaloy at high temperatures for light water reactor loss-of-coolant-accident investigations

International Nuclear Information System (INIS)

Raff, S.

1982-11-01

To describe Zircaloy-4 deformation and failure behaviour at high temperatures (600 to 1400 0 C), the phenomenological model NORA was developed and verified against numerous experimental results. The model can be applied to the calculation of fuel rod cladding deformation during small and large break loss-of-coolant-accidents. (orig./RW) [de

High-carbon chromium steel resistance to small plastic deformation

International Nuclear Information System (INIS)

Gajduchenya, V.F.; Madyanov, S.A.; Apaev, B.A.; Kirillov, Yu.V.; Sokolov, L.D.

1978-01-01

The phase composition of a steel with 1.08% C and 2.1% Cr, and the variation in the level of microstresses in the matrix as related to the annealing temperature in the range of 400-600 deg C and in the applied compression stress were investigated. To study the phase composition, and chromium content in the α-solution and the carbide phases, magnetic, chemical, and X-ray spectrum analyses were carried out. The change in the level of microstresses was determined roentgenographically. During the stress relaxation test at temperatures of 20-180 deg C, the mechanism of plastic deformation near the yield point was investigated. It is shown that three dislocation mechanisms operate in high-carbon chromium steel under the conditions at hand: overcoming the Pierls-Nabarro barriers by the dislocations, overcoming the stress fields of coherent carbide particles by dislocations, and circumvention of second-phase particles by dislocations. The dependence of the realization of the different plastic deformation mechanisms on the number of carbide particles and the chromium concentration in the matrix was established. The thermally activated nature of the motion of the dislocations under conditions of stress relaxation at an elevated temperature is noted

Direct observations of blob deformation during a substorm

Directory of Open Access Journals (Sweden)

T. Ishida

2015-05-01

Full Text Available Ionospheric blobs are localized plasma density enhancements, which are mainly produced by the transportation process of plasma. To understand the deformation process of a blob, observations of plasma parameters with good spatial–temporal resolution are desirable. Thus, we conducted the European Incoherent Scatter radar observations with high-speed meridional scans (60–80 s during October and December 2013, and observed the temporal evolution of a blob during a substorm on 4 December 2013. This paper is the first report of direct observations of blob deformation during a substorm. The blob deformation arose from an enhanced plasma flow shear during the substorm expansion phase, and then the blob split into two smaller-scale blobs, whose scale sizes were more than ~100 km in latitude. Our analysis indicates that the Kelvin–Helmholtz instability and dissociative recombination could have deformed the blob structure.

Microstructure and mechanical properties of precipitation hardened aluminum under high rate deformation

International Nuclear Information System (INIS)

Grady, D.E.; Asav, J.R.; Rohde, R.W.; Wise, J.L.

1983-01-01

This chapter attempts to correlate the shock compression and quasistatic deformation of 6061-T6 aluminium. Examines recovered specimens which have been shock loaded, and compares results with both static and dynamic mechanical property measurements. Discusses experimental procedures (reshock and unloading experiments, shock recovery techniques, metallographic techniques and coldwork experiments); dynamic strength and wave-profile properties (strength and shear-stress states on the Hugoniot, steady-wave risetime and viscosity); quasistatic and shock metallography studies (metallography of quasistatically deformed material; metallography of shock deformed specimens; comparison of static and shock deformation; correlation of hardness and dynamic strength measurements); and thermal trapping calculations in shocked aluminium (heterogeneous deformation and adiabatic heating in shock-wave loading; energy and risetime relations under steadywave shock compression; heterogeneous temperature calculations in aluminium). Concludes that heterogeneous shear deformation appears to play a role in the dynamic deformation process

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...

Using cold deformation methods in flow-production of steel high precision shaped sections

International Nuclear Information System (INIS)

Zajtsev, M.L.; Makhnev, I.F.; Shkurko, I.I.

1975-01-01

A final size with a preset tolerance and a required surface finish of steel high-precision sections could be achieved by a cold deformation of hot-rolled ingots-by drawing through dismountable, monolith or roller-type drawing tools or by cold rolling in roller dies. The particularities of the both techniques are compared as regards a number of complicated shaped sections and the advantages of cold rolling are showna more uniform distribution of deformations (strain hardening) across the section, that is a greater margin of plasticity with the same reductions, the less number of the operations required. Rolling is recommended in all the cases when possible as regards the section shape and the bulk volume. The rolling-mill for the calibration of high-precision sections should have no less than two shafts (so that the size could be controlled in both directions) and arrangements to withstand high axial stresses on the rollers (the stresses appearing during rolling in skew dies). When manufacturing precise shaped sections by the cold rolling method the operations are less plentiful than in the cold drawing manufacturing

Radiative-lifetime measurements and calculations of odd-parity highly excited levels in Ba i

International Nuclear Information System (INIS)

Zhang Wei; Du Shan; Palmeri, Patrick; Quinet, Pascal; Biemont, Emile; Dai Zhenwen

2010-01-01

Natural radiative lifetime measurements have been performed for 70 odd-parity highly excited levels of neutral barium in the energy range from 308 15.512 to 417 59.93 cm -1 by a time-resolved laser-induced fluorescence technique in a laser-produced plasma. The lifetime values measured in this paper are in the range from 11.3 to 901 ns. They are compared with the published lifetimes of four levels. Two of them are in good agreement, whereas for the other two our measurements are slightly longer than the published data. The reasons for the discrepancies are discussed. Comparisons with theoretical results of the Hartree-Fock method with relativistic corrections illustrate the difficulties associated with the use of Cowan's codes for obtaining accurate branching fractions for transitions depopulating highly excited levels along the Rydberg series of heavy neutral elements. This work will be useful to extend the set of oscillator strengths available in Ba i.

Chondrocyte deformations as a function of tibiofemoral joint loading predicted by a generalized high-throughput pipeline of multi-scale simulations.

Directory of Open Access Journals (Sweden)

Scott C Sibole

Full Text Available Cells of the musculoskeletal system are known to respond to mechanical loading and chondrocytes within the cartilage are not an exception. However, understanding how joint level loads relate to cell level deformations, e.g. in the cartilage, is not a straightforward task. In this study, a multi-scale analysis pipeline was implemented to post-process the results of a macro-scale finite element (FE tibiofemoral joint model to provide joint mechanics based displacement boundary conditions to micro-scale cellular FE models of the cartilage, for the purpose of characterizing chondrocyte deformations in relation to tibiofemoral joint loading. It was possible to identify the load distribution within the knee among its tissue structures and ultimately within the cartilage among its extracellular matrix, pericellular environment and resident chondrocytes. Various cellular deformation metrics (aspect ratio change, volumetric strain, cellular effective strain and maximum shear strain were calculated. To illustrate further utility of this multi-scale modeling pipeline, two micro-scale cartilage constructs were considered: an idealized single cell at the centroid of a 100×100×100 μm block commonly used in past research studies, and an anatomically based (11 cell model of the same volume representation of the middle zone of tibiofemoral cartilage. In both cases, chondrocytes experienced amplified deformations compared to those at the macro-scale, predicted by simulating one body weight compressive loading on the tibiofemoral joint. In the 11 cell case, all cells experienced less deformation than the single cell case, and also exhibited a larger variance in deformation compared to other cells residing in the same block. The coupling method proved to be highly scalable due to micro-scale model independence that allowed for exploitation of distributed memory computing architecture. The method's generalized nature also allows for substitution of any macro

Chondrocyte Deformations as a Function of Tibiofemoral Joint Loading Predicted by a Generalized High-Throughput Pipeline of Multi-Scale Simulations

Science.gov (United States)

Sibole, Scott C.; Erdemir, Ahmet

2012-01-01

Cells of the musculoskeletal system are known to respond to mechanical loading and chondrocytes within the cartilage are not an exception. However, understanding how joint level loads relate to cell level deformations, e.g. in the cartilage, is not a straightforward task. In this study, a multi-scale analysis pipeline was implemented to post-process the results of a macro-scale finite element (FE) tibiofemoral joint model to provide joint mechanics based displacement boundary conditions to micro-scale cellular FE models of the cartilage, for the purpose of characterizing chondrocyte deformations in relation to tibiofemoral joint loading. It was possible to identify the load distribution within the knee among its tissue structures and ultimately within the cartilage among its extracellular matrix, pericellular environment and resident chondrocytes. Various cellular deformation metrics (aspect ratio change, volumetric strain, cellular effective strain and maximum shear strain) were calculated. To illustrate further utility of this multi-scale modeling pipeline, two micro-scale cartilage constructs were considered: an idealized single cell at the centroid of a 100×100×100 μm block commonly used in past research studies, and an anatomically based (11 cell model of the same volume) representation of the middle zone of tibiofemoral cartilage. In both cases, chondrocytes experienced amplified deformations compared to those at the macro-scale, predicted by simulating one body weight compressive loading on the tibiofemoral joint. In the 11 cell case, all cells experienced less deformation than the single cell case, and also exhibited a larger variance in deformation compared to other cells residing in the same block. The coupling method proved to be highly scalable due to micro-scale model independence that allowed for exploitation of distributed memory computing architecture. The method’s generalized nature also allows for substitution of any macro-scale and/or micro

Fluid-Driven Deformation of a Soft Porous Medium

Science.gov (United States)

Lutz, Tyler; Wilen, Larry; Wettlaufer, John

2017-11-01

Viscous drag forces resisting the flow of fluid through a soft porous medium are maintained by restoring forces associated with deformations in the solid matrix. We describe experimental measurements of the deformation of foam under a pressure-driven flow of water along a single axis. Image analysis techniques allow tracking of the foam displacement while pressure sensors allow measurement of the fluid pressure. Experiments are performed for a series of different pressure heads ranging from 10 to 90 psi, and the results are compared to theory. This work builds on previous measurements of the fluid-induced deformation of a bed of soft hydrogel spheres. Compared to the hydrogel system, foams have the advantage that the constituents of the porous medium do not rearrange during an experiment, but they have the disadvantage of having a high friction coefficient with any boundaries. We detail strategies to characterize and mitigate the effects of friction on the observed foam deformations.

High quality transmission Kikuchi diffraction analysis of deformed alloys - Case study

International Nuclear Information System (INIS)

Tokarski, Tomasz; Cios, Grzegorz; Kula, Anna; Bała, Piotr

2016-01-01

Modern scanning electron microscopes (SEM) equipped with thermally assisted field emission guns (Schottky FEG) are capable of imaging with a resolution in the range of several nanometers or better. Simultaneously, the high electron beam current can be used, which enables fast chemical and crystallographic analysis with a higher resolution than is normally offered by SEM with a tungsten cathode. The current resolution that limits the EDS and EBSD analysis is related to materials' physics, particularly to the electron-specimen interaction volume. The application of thin, electron-transparent specimens, instead of bulk samples, improves the resolution and allows for the detailed analysis of very fine microstructural features. Beside the typical imaging mode, it is possible to use a standard EBSD camera in such a configuration that only transmitted and scattered electrons are detected. This modern approach was successfully applied to various materials giving rise to significant resolution improvement, especially for the light element magnesium based alloys. This paper presents an insight into the application of the transmission Kikuchi diffraction (TKD) technique applied to the most troublesome, heavily-deformed materials. In particular, the values of the highest possible acquisition rates for high resolution and high quality mapping were estimated within typical imaging conditions of stainless steel and magnesium-yttrium alloy. - Highlights: •Monte Carlo simulations were used to simulate EBSD camera intensity for various measuring conditions. •Transmission Kikuchi diffraction parameters were evaluated for highly deformed, light and heavy elements based alloys. •High quality maps with 20 nm spatial resolution were acquired for Mg and Fe based alloys. •High speed TKD measurements were performed at acquisition rates comparable to the reflection EBSD.

Formation of defects at high temperature plastic deformation of gallium arsenide

Energy Technology Data Exchange (ETDEWEB)

Mikhnovich, V.V.

2006-03-14

The purpose of the present thesis consists in acquiring more concrete information concerning the mechanism of the movement of dislocations and types of defects that appear during the process of dislocation motion on the basis of systematic experimental studies of the GaAs deformation. Experimental studies concerning the dependence of the stress of the samples from their deformation at different values of the deformation parameters (like temperature and deformation speed) were conducted in this paper. To determine the concentration of defects introduced in samples during the deformation process the positron annihilation spectroscopy (PAS) method was used. The second chapter of this paper deals with models of movement of dislocations and origination of defects during deformation of the samples. In the third chapter channels and models of positron annihilation in the GaAs samples are investigated. In the forth chapter the used experimental methods, preparation procedure of test samples and technical data of conducted experiments are described. The fifth chapter shows the results of deformation experiments. The sixth chapter shows the results of positron lifetime measurements by the PAS method. In the seventh chapter one can find analyses of the values of defects concentration that were introduced in samples during deformation. (orig.)

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

Deformation microstructures

DEFF Research Database (Denmark)

Hansen, N.; Huang, X.; Hughes, D.A.

2004-01-01

Microstructural characterization and modeling has shown that a variety of metals deformed by different thermomechanical processes follows a general path of grain subdivision, by dislocation boundaries and high angle boundaries. This subdivision has been observed to very small structural scales...... of the order of 10 nm, produced by deformation under large sliding loads. Limits to the evolution of microstructural parameters during monotonic loading have been investigated based on a characterization by transmission electron microscopy. Such limits have been observed at an equivalent strain of about 10...

Effect of Deformation Temperature on Microstructure Evolution and Mechanical Properties of Low-Carbon High-Mn Steel

Directory of Open Access Journals (Sweden)

Adam Grajcar

2018-01-01

Full Text Available This work addresses the influence of deformation temperature in a range from −40°C to 200°C on the microstructure evolution and mechanical properties of a low-carbon high-manganese austenitic steel. The temperature range was chosen to cope at the time during sheet processing or car crash events. Experimental results show that yield stress and ultimate tensile strength gradually deteriorate with an increase in the tensile testing temperature. The dominant mechanism responsible for the strain hardening of steel changes as a function of deformation temperature, which is related to stacking fault energy (SFE changes. When the deformation temperature rises, twinning decreases while a role of dislocation slip increases.

A very light CP-odd scalar in the Two-Higgs-Doublet Model

CERN Document Server

Larios, F; Yuan, C P; CERN. Geneva

2001-01-01

We show that a general two-Higgs-doublet model (THDM) with a very light CP-odd scalar (A) can be compatible with the rho parameter, Br(b --> s\\gamma), R_b, A_b, (g-2) of muon, Br(Upsilon --> A gamma), and the direct search via the Yukawa process at LEP. For its mass around 0.2 GeV, the muon (g-2) and Br(Upsilon --> A \\gamma) data require tan(beta) to be about 1. Consequently, A can behave like a fermiophobic CP-odd scalar and predominantly decay into a photon pair ("gamma gamma"), which registers in detectors of high energy collider experiments as a single photon signature when the momentum of A is large. We compute the partial decay width of Z --> A A A and the production rate of f \\bar{f} --> Z A A --> Z +"gamma gamma", f^' {\\bar f} --> W^{\\pm} A A --> W^\\pm + "gamma gamma" and f \\bar f --> H^+ H^- --> W^+ W^- A A --> W^+ W^- + "gamma gamma" at high energy colliders such as LEP, Tevatron, LHC, and future Linear Colliders. Other production mechanisms of a light A, such as gg --> h --> AA --> "gamma gamma", a...

Ultra-high aspect ratio replaceable AFM tips using deformation-suppressed focused ion beam milling

International Nuclear Information System (INIS)

Savenko, Alexey; Yildiz, Izzet; Petersen, Dirch Hjorth; Bøggild, Peter; Bartenwerfer, Malte; Krohs, Florian; Oliva, Maria; Harzendorf, Torsten

2013-01-01

Fabrication of ultra-high aspect ratio exchangeable and customizable tips for atomic force microscopy (AFM) using lateral focused ion beam (FIB) milling is presented. While on-axis FIB milling does allow high aspect ratio (HAR) AFM tips to be defined, lateral milling gives far better flexibility in terms of defining the shape and size of the tip. Due to beam-induced deformation, it has so far not been possible to define HAR structures using lateral FIB milling. In this work we obtain aspect ratios of up to 45, with tip diameters down to 9 nm, by a deformation-suppressing writing strategy. Several FIB milling strategies for obtaining sharper tips are discussed. Finally, assembly of the HAR tips on a custom-designed probe as well as the first AFM scanning is shown. (paper)

Nuclear structure of the N = Z odd - odd nuclei around N=28 closed shell interpreted with IBFFM

International Nuclear Information System (INIS)

Dragulescu, E.; Serbanut, G. C.; Serbanut, I.

2001-01-01

In the very recent years the knowledge of the level structure at lower and higher energies in the fpg shell N=Z nuclei has renewed a growing interest due to major improvements in the theoretical techniques. Going away from closed shell, the shell model calculations rapidly exhaust computer capabilities and we must resort to the model observed on collective phenomena. The fpg odd-odd N = Z nuclei close to the doubly magic 56 Ni nucleus are good candidates to investigate the competition between collective and single-particle excitations. Here part of the results obtained from an exhaustive systematic study of the self conjugate doubly-odd nuclei with A > 62: 62 Ga and 66 As nuclei using the interacting - boson - fermion - fermion - model (IBFFM) is presented. The odd-odd nuclei are described in the framework of the IBFFM by coupling valence shell proton and neutron quasiparticles to even-even core described in the interacting - boson model. In the first step of the calculations the core parameters for 60 Zn and 64 Ge cores were fitted to the energies of their excited states. In the second step of calculations, we have adjusted the IBFM proton Hamiltonian to the low - lying levels of 63 Ga and 67 As nuclei and IBFM neutron Hamiltonian of low - lying levels of 61 Zn and 65 Ge nuclei involved in the cases of the structure of odd-odd 62 Ga and 66 As nuclei. We have finally calculated the level spectra and electromagnetic properties of above mentioned nuclei. The IBFFM positive - parity energy spectra are compared with experimental ones. The calculations show a reasonable agreement with experimental data and existing shell - model calculations. (authors)

Cirrus Airframe Parachute System and Odds of a Fatal Accident in Cirrus Aircraft Crashes.

Science.gov (United States)

Alaziz, Mustafa; Stolfi, Adrienne; Olson, Dean M

2017-06-01

General aviation (GA) accidents have continued to demonstrate high fatality rates. Recently, ballistic parachute recovery systems (BPRS) have been introduced as a safety feature in some GA aircraft. This study evaluates the effectiveness and associated factors of the Cirrus Airframe Parachute System (CAPS) at reducing the odds of a fatal accident in Cirrus aircraft crashes. Publicly available Cirrus aircraft crash reports were obtained from the National Transportation Safety Board (NTSB) database for the period of January 1, 2001-December 31, 2016. Accident metrics were evaluated through univariate and multivariate analyses regarding odds of a fatal accident and use of the parachute system. Included in the study were 268 accidents. For CAPS nondeployed accidents, 82 of 211 (38.9%) were fatal as compared to 8 of 57 (14.0%) for CAPS deployed accidents. After controlling for all other factors, the adjusted odds ratio for a fatal accident when CAPS was not deployed was 13.1. The substantial increased odds of a fatal accident when CAPS was not deployed demonstrated the effectiveness of CAPS at providing protection of occupants during an accident. Injuries were shifted from fatal to serious or minor with the use of CAPS and postcrash fires were significantly reduced. These results suggest that BPRS could play a significant role in the next major advance in improving GA accident survival.Alaziz M, Stolfi A, Olson DM. Cirrus Airframe Parachute System and odds of a fatal accident in Cirrus aircraft crashes. Aerosp Med Hum Perform. 2017; 88(6):556-564.

Thermally induced processes in mixtures of aluminum with organic acids after plastic deformations under high pressure

Science.gov (United States)

Zhorin, V. A.; Kiselev, M. R.; Roldugin, V. I.

2017-11-01

DSC is used to measure the thermal effects of processes in mixtures of solid organic dibasic acids with powdered aluminum, subjected to plastic deformation under pressures in the range of 0.5-4.0 GPa using an anvil-type high-pressure setup. Analysis of thermograms obtained for the samples after plastic deformation suggests a correlation between the exothermal peaks observed around the temperatures of degradation of the acids and the thermally induced chemical reactions between products of acid degradation and freshly formed surfaces of aluminum particles. The release of heat in the mixtures begins at 30-40°C. The thermal effects in the mixtures of different acids change according to the order of acid reactivity in solutions. The extreme baric dependences of enthalpies of thermal effects are associated with the rearrangement of the electron subsystem of aluminum upon plastic deformation at high pressures.

Large-strain time-temperature equivalence in high density polyethylene for prediction of extreme deformation and damage

Directory of Open Access Journals (Sweden)

Gray G.T.

2012-08-01

Full Text Available Time-temperature equivalence is a widely recognized property of many time-dependent material systems, where there is a clear predictive link relating the deformation response at a nominal temperature and a high strain-rate to an equivalent response at a depressed temperature and nominal strain-rate. It has been found that high-density polyethylene (HDPE obeys a linear empirical formulation relating test temperature and strain-rate. This observation was extended to continuous stress-strain curves, such that material response measured in a load frame at large strains and low strain-rates (at depressed temperatures could be translated into a temperature-dependent response at high strain-rates and validated against Taylor impact results. Time-temperature equivalence was used in conjuction with jump-rate compression tests to investigate isothermal response at high strain-rate while exluding adiabatic heating. The validated constitutive response was then applied to the analysis of Dynamic-Tensile-Extrusion of HDPE, a tensile analog to Taylor impact developed at LANL. The Dyn-Ten-Ext test results and FEA found that HDPE deformed smoothly after exiting the die, and after substantial drawing appeared to undergo a pressure-dependent shear damage mechanism at intermediate velocities, while it fragmented at high velocities. Dynamic-Tensile-Extrusion, properly coupled with a validated constitutive model, can successfully probe extreme tensile deformation and damage of polymers.

Extracting a Purely Non-rigid Deformation Field of a Single Structure

Science.gov (United States)

Demirci, Stefanie; Manstad-Hulaas, Frode; Navab, Nassir

During endovascular aortic repair (EVAR) treatment, the aortic shape is subject to severe deformation that is imposed by medical instruments such as guide wires, catheters, and the stent graft. The problem definition of deformable registration of images covering the entire abdominal region, however, is highly ill-posed. We present a new method for extracting the deformation of an aneurysmatic aorta. The outline of the procedure includes initial rigid alignment of two abdominal scans, segmentation of abdominal vessel trees, and automatic reduction of their centerline structures to one specified region of interest around the aorta. Our non-rigid registration procedure then only computes local non-rigid deformation and leaves out all remaining global rigid transformations. In order to evaluate our method, experiments for the extraction of aortic deformation fields are conducted on 15 patient datasets from endovascular aortic repair (EVAR) treatment. A visual assessment of the registration results were performed by two vascular surgeons and one interventional radiologist who are all experts in EVAR procedures.

Coriolis force and nuclear deformation: cadmium and lead isotopes results with the EUROBALL gamma multidetector

International Nuclear Information System (INIS)

Buforn, Nadege

2001-01-01

This work is devoted to the study of the nuclear matter at high rotational frequency. Thanks to the new generation of γ-ray multidetector array, as EUROGAM then EUROBALL, we propose to identify two sorts of nuclei belonging to two different mass region. Their identification is based on the detection of their γ-rays of des-excitation. We will follow the evolution of the influence of the Coriolis force at the microscopic scale. The cadmium nuclei 113-116 Cd have been populated using heavy-ion induced fission reaction ( 28 Si+ 176 Yb at 145 MeV). Decoupled bands have been identified in odd-nuclei, produced for the first time at high spin. As they were considered as the best example of vibrational nuclei during their studies by radioactivity, they exhibit a small prolate deformation, confirmed by our microscopic calculations performed for even-even nuclei. The odd superdeformed nucleus 197 Pb have been studied via a fusion-evaporation reaction ( 18 O+ 186 W at 117 MeV). We have established the cross-talk transitions between the two signature partners. The experimental measurement of the branching ratio B(M1)/B(E2) allows us to extract the magnetic properties of the superdeformed matter, conforming the lack of quenching for the neutrons. The Coriolis force depends on the nuclei deformation and on the individual configuration. In cadmium nuclei, the single neutron νh 11/2 , Ω=1/2 is decoupled from the motion of the core, whereas in superdeformed nuclei, the Coriolis effect is much weaker on the νj 15/2 , Ω = 5/2 neutron. (author)

Measuring High Speed Deformation for Space Applications

Science.gov (United States)

Wentzel, Daniel

2014-01-01

PDV (Photonic Doppler Velocimetry) has proven to be a reliable and versatile technique to observe rapid deformation of frangible joints. It will be a valuable technique in order to understand the physics of two-stage light gas guns and the material response to hypervelocity impact.

Deformation of cylindrical vessel and the effect of barrel on deformation under inpulsive pressure of high explosive

International Nuclear Information System (INIS)

Iikura, Shoichi; Yashizawa, Hiroyasu; Sasanuma, Katsumi.

1982-01-01

According to the research performed so far, the result that the amount of deformation due to impulsive pressure was able to be evaluated by the impulse of impulsive pressure waves has been obtained. The analysis treating impulsive pressure waves as plane waves has been made frequently, but the analysis in which impulsive pressure waves must be treated as spherical waves, or the analysis of a vessel with a barrel (internal cylinder) is complex and difficult. In this report, the results of element test, which was carried out in the Oita Works, Asahi Chemical Industry Co., Ltd., in 1973 by the Power Reactor and Nuclear Fuel Development Corp. as the impact resistance test for fast breeder reactors, are rearranged and investigated. The specimens were the cylindrical vessels with upper and lower flanges, and 10 vessels and 9 kinds of barrels were made. Water was used as the pressure medium. The residual deformation and dynamic strain of the vessels and the wave form of pressure waves were measured. The deformation of cylindrical vessels subjected to the impulsive pressure from a point pressure source was able to be evaluated by the impulse distribution in normal direction. The maximum amount of deformation depended on the total plate thickness of barrels. (Kako, I.)

Formation of incoherent deformation twin boundaries in a coarse-grained Al-7Mg alloy

Science.gov (United States)

Jin, S. B.; Zhang, K.; Bjørge, R.; Tao, N. R.; Marthinsen, K.; Lu, K.; Li, Y. J.

2015-08-01

Deformation twinning has rarely been observed in coarse grained Al and its alloys except under some extreme conditions such as ultrahigh deformation strain or strain rates. Here, we report that a significant amount of Σ3 deformation twins could be generated in a coarse-grained Al-7 Mg alloy by dynamic plastic deformation (DPD). A systematic investigation of the Σ3 boundaries shows that they are Σ3{112} type incoherent twin boundaries (ITBs). These ITBs have formed by gradual evolution from copious low-angle deformation bands through -twist Σ boundaries by lattice rotation. These findings provide an approach to generate deformation twin boundaries in high stacking fault energy metallic alloys. It is suggested that high solution content of Mg in the alloy and the special deformation mode of DPD played an important role in formation of the Σ and ITBs.

Coulomb excitation of the odd-odd isotopes $^{106, 108}$In

CERN Document Server

Ekstrom, A; Blazhev, A; Van de Walle, J; Weisshaar, D; Zielinska, M; Tveten, G M; Marsh, B A; Siem, S; Gorska, M; Engeland, T; Hurst, A M; Cederkall, J; Finke, F; Iwanicki, J; Hjorth-Jensen, M; Davinson, T; Eberth, J; Sletten, G; Mierzejewski, J; Reiter, P; Warr, N; Butler, P A; Fahlander, C; Stefanescu, I; Koester, U; Ivanov, O; Wenander, F; Voulot, D

2010-01-01

The low-lying states in the odd-odd and unstable isotopes In-106,In-108 have been Coulomb excited from the ground state and the first excited isomeric state at the REX-ISOLDE facility at CERN. With the additional data provided here the pi g(9/2)(-1) circle times nu d(5/2) and pi g(9/2)(-1) circle times nu g7/2 multiplets have been re-analyzed and are modified compared to previous results. The observed gamma-ray de-excitation patterns were interpreted within a shell model calculation based on a realistic effective interaction. The agreement between theory and experiment is satisfactory and the calculations reproduce the observed differences in the excitation pattern of the two isotopes. The calculations exclude a 6(+) ground state in In-106. This is in agreement with the conclusions drawn using other techniques. Furthermore, based on the experimental results, it is also concluded that the ordering of the isomeric and ground state in In-108 is inverted compared to the shell model prediction. Limits on B(E2) val...

Deformation limits of polymer coated metal sheets

NARCIS (Netherlands)

Van Den Bosch, M.J.W.J.P.; Schreurs, P.J.G; Geers, M.G.D.

2005-01-01

Polymer coated metals are increasingly used by the packaging and automotive industry. During industrial deformation processes (drawing, roll-forming, bending etc.) the polymer-metal laminate is highly deformed at high deformation rates. These forming conditions can affect the mechanical integrity

Odd-odd neutron-excess nuclei from the magicity region close to 132Sn

International Nuclear Information System (INIS)

Erokhina, K.I.; Isakov, V.I.

1994-01-01

This is the second publication in a series devoted to theoretical study of neutron-excess nuclei close to the doubly magic nuclide 132 Sn. Odd-odd nuclei from this region are considered by using the quasi-boson approximation. Energy level spectra, electromagnetic transition probabilities, and β-decay properties of nuclei are analyzed. Among other things, the renormalization of the axial-vector constant in the nucleus is determined. Numerical calculations are made for 134 Sb, 130 In, 132 Sb, and 132 In nuclides. Whenever possible, the results are compared with experimental data. 33 refs., 11 figs., 1 tab

Quasi-instantaneous and Long-term Deformations of High-Performance Concrete with Some Related Properties

OpenAIRE

Persson, Bertil

1998-01-01

This report outlines an experimental and numerical study on quasi-instantaneous and long-term deformations of High-Performance Concrete, HPC, with some related properties. For this purpose about two hundred small cylinders and about one thousand cubes of eight types of HPC were cast. The age at loading varied between 18h and 28 days. Other principal properties of HPC were studied up to 4 years' age. Creep deformations of the HPC were studied from 0.01 s of loading time until 5 years' ...

The odd side of torsion geometry

DEFF Research Database (Denmark)

Conti, Diego; Madsen, Thomas Bruun

2014-01-01

We introduce and study a notion of `Sasaki with torsion structure' (ST) as an odd-dimensional analogue of Kähler with torsion geometry (KT). These are normal almost contact metric manifolds that admit a unique compatible connection with 3-form torsion. Any odd-dimensional compact Lie group is sho...

Thermal behavior of Ni (99.967% and 99.5% purity) deformed to an ultra-high strain by high pressure torsion

DEFF Research Database (Denmark)

Zhang, H.W.; Huang, Xiaoxu; Pippan, R.

2010-01-01

Polycrystalline Ni of two purities (99.967% (4N) and 99.5% (2N)) was deformed to an ultra-high strain of εvM = 100 (εvM, von Mises strain) by high pressure torsion at room temperature. The 4N and 2N samples at this strain are nanostructured with an average boundary spacing of 100 nm, a high density...

Odd-frequency pairing in superconducting heterostructures .

Science.gov (United States)

Golubov, A. A.; Tanaka, Y.; Yokoyama, T.; Asano, Y.

2007-03-01

We present a general theory of the proximity effect in junctions between unconventional superconductors and diffusive normal metals (DN) or ferromagnets (DF). We consider all possible symmetry classes in a superconductor allowed by the Pauli principle: even-frequency spin-singlet even-parity state, even-frequency spin-triplet odd-parity state, odd-frequency spin-triplet even-parity state and odd-frequency spin-singlet odd-parity state. For each of the above states, symmetry and spectral properties of the induced pair amplitude in the DN (DF) are determined. The cases of junctions with spin-singlet s- and d-wave superconductors and spin-triplet p-wave superconductors are adressed in detail. We discuss the interplay between the proximity effect and midgap Andreev bound states arising at interfaces in unconventional (d- or p-wave) junctions. The most striking property is the odd-frequency symmetry of the pairing amplitude induced in DN (DF) in contacts with p-wave superconductors. This leads to zero-energy singularity in the density of states and to anomalous screening of an external magnetic field. Peculiarities of Josephson effect in d- or p-wave junctions are discussed. Experiments are suggested to detect an order parameter symmetry using heterostructures with unconventional superconductors.

Electro-Deformation of Fused Cells in a Microfluidic Array Device

Directory of Open Access Journals (Sweden)

Yan Liu

2016-11-01

Full Text Available We present a new method of analyzing the deformability of fused cells in a microfluidic array device. Electrical stresses—generated by applying voltages (4–20 V across discrete co-planar microelectrodes along the side walls of a microfluidic channel—have been used to electro-deform fused and unfused stem cells. Under an electro-deformation force induced by applying an alternating current (AC signal, we observed significant electro-deformation phenomena. The experimental results show that the fused stem cells were stiffer than the unfused stem cells at a relatively low voltage (<16 V. However, at a relatively high voltage, the fused stem cells were more easily deformed than were the unfused stem cells. In addition, the electro-deformation process is modeled based on the Maxwell stress tensor and structural mechanics of cells. The theoretical results show that a positive correlation is found between the deformation of the cell and the applied voltage, which is consistent with the experimental results. Combined with a numerical analysis and experimental study, the results showed that the significant difference of the deformation ratio of the fused and unfused cells is not due to their size difference. This demonstrates that some other properties of cell membranes (such as the membrane structure were also changed in the electrofusion process, in addition to the size modification of that process.

Degenerate odd Poisson bracket on Grassmann variables

International Nuclear Information System (INIS)

Soroka, V.A.

2000-01-01

A linear degenerate odd Poisson bracket (antibracket) realized solely on Grassmann variables is proposed. It is revealed that this bracket has at once three Grassmann-odd nilpotent Δ-like differential operators of the first, second and third orders with respect to the Grassmann derivatives. It is shown that these Δ-like operators, together with the Grassmann-odd nilpotent Casimir function of this bracket, form a finite-dimensional Lie superalgebra

How classical gluon fields generate odd azimuthal harmonics for the two-gluon correlation function in high-energy collisions

Science.gov (United States)

Kovchegov, Yuri V.; Skokov, Vladimir V.

2018-05-01

We show that, in the saturation/color glass condensate framework, odd azimuthal harmonics of the two-gluon correlation function with a long-range separation in rapidity are generated by the higher-order saturation corrections in the interactions with the projectile and the target. At the very least, the odd harmonics require three scatterings in the projectile and three scatterings in the target. We derive the leading-order expression for the two-gluon production cross section which generates odd harmonics: the expression includes all-order interactions with the target and three interactions with the projectile. We evaluate the obtained expression both analytically and numerically, confirming that the odd-harmonics contribution to the two-gluon production in the saturation framework is nonzero.

Deformation mechanisms of nanotwinned Al

Energy Technology Data Exchange (ETDEWEB)

Zhang, Xinghang [Texas A & M Univ., College Station, TX (United States)

2016-11-10

The objective of this project is to investigate the role of different types of layer interfaces on the formation of high density stacking fault (SF) in Al in Al/fcc multilayers, and understand the corresponding deformation mechanisms of the films. Stacking faults or twins can be intentionally introduced (via growth) into certain fcc metals with low stacking fault energy (such as Cu, Ag and 330 stainless steels) to achieve high strength, high ductility, superior thermal stability and good electrical conductivity. However it is still a major challenge to synthesize these types of defects into metals with high stacking fault energy, such as Al. Although deformation twins have been observed in some nanocrystalline Al powders by low temperature, high strain rate cryomilling or in Al at the edge of crack tip or indentation (with the assistance of high stress intensity factor), these deformation techniques typically introduce twins sporadically and the control of deformation twin density in Al is still not feasible. This project is designed to test the following hypotheses: (1) Certain type of layer interfaces may assist the formation of SF in Al, (2) Al with high density SF may have deformation mechanisms drastically different from those of coarse-grained Al and nanotwinned Cu. To test these hypotheses, we have performed the following tasks: (i) Investigate the influence of layer interfaces, stresses and deposition parameters on the formation and density of SF in Al. (ii) Understand the role of SF on the deformation behavior of Al. In situ nanoindentation experiments will be performed to probe deformation mechanisms in Al. The major findings related to the formation mechanism of twins and mechanical behavior of nanotwinned metals include the followings: 1) Our studies show that nanotwins can be introduced into metals with high stacking fault energy, in drastic contrast to the general anticipation. 2) We show two strategies that can effectively introduce growth twins in

Deformation mechanisms of nanotwinned Al

International Nuclear Information System (INIS)

Zhang, Xinghang

2016-01-01

The objective of this project is to investigate the role of different types of layer interfaces on the formation of high density stacking fault (SF) in Al in Al/fcc multilayers, and understand the corresponding deformation mechanisms of the films. Stacking faults or twins can be intentionally introduced (via growth) into certain fcc metals with low stacking fault energy (such as Cu, Ag and 330 stainless steels) to achieve high strength, high ductility, superior thermal stability and good electrical conductivity. However it is still a major challenge to synthesize these types of defects into metals with high stacking fault energy, such as Al. Although deformation twins have been observed in some nanocrystalline Al powders by low temperature, high strain rate cryomilling or in Al at the edge of crack tip or indentation (with the assistance of high stress intensity factor), these deformation techniques typically introduce twins sporadically and the control of deformation twin density in Al is still not feasible. This project is designed to test the following hypotheses: (1) Certain type of layer interfaces may assist the formation of SF in Al, (2) Al with high density SF may have deformation mechanisms drastically different from those of coarse-grained Al and nanotwinned Cu. To test these hypotheses, we have performed the following tasks: (i) Investigate the influence of layer interfaces, stresses and deposition parameters on the formation and density of SF in Al. (ii) Understand the role of SF on the deformation behavior of Al. In situ nanoindentation experiments will be performed to probe deformation mechanisms in Al. The major findings related to the formation mechanism of twins and mechanical behavior of nanotwinned metals include the followings: 1) Our studies show that nanotwins can be introduced into metals with high stacking fault energy, in drastic contrast to the general anticipation. 2) We show two strategies that can effectively introduce growth twins in

Constitutive Modelling and Deformation Band Angle Predictions for High Porosity Sandstones

Science.gov (United States)

Richards, M. C.; Issen, K. A.; Ingraham, M. D.

2017-12-01

The development of a field-scale deformation model requires a constitutive framework that is capable of representing known material behavior and able to be calibrated using available mechanical response data. This work employs the principle of hyperplasticity (e.g., Houlsby and Puzrin, 2006) to develop such a constitutive framework for high porosity sandstone. Adapting the works of Zimmerman et al. (1986) and Collins and Houlsby (1997), the mechanical data set of Ingraham et al. (2013 a, b) was used to develop a specific constitutive framework for Castlegate sandstone, a high porosity fluvial-deposited reservoir analog rock. Using the mechanical data set of Ingraham et al. (2013 a, b), explicit expressions and material parameters of the elastic moduli and strain tensors were obtained. With these expressions, analytical and numerical techniques were then employed to partition the total mechanical strain into elastic, coupled, and plastic strain components. With the partitioned strain data, yield surfaces in true-stress space, coefficients of internal friction, dilatancy factors, along with the theorectical predictions of the deformation band angles were obtained. These results were also evaluated against band angle values obtained from a) measurements on specimen jackets (Ingraham et al., 2013a), b) plane fits through located acoustic emissions (AE) events (Ingraham et al. 2013b), and c) X-ray micro-computed tomography (micro-CT) calculations.

Microstructural evolution during tensile deformation of polypropylenes

International Nuclear Information System (INIS)

Dasari, A.; Rohrmann, J.; Misra, R.D.K.

2003-01-01

Tensile deformation processes occurring at varying strain rates in high and low crystallinity polypropylenes and ethylene-propylene di-block copolymers have been investigated by scanning electron microscopy. This is examined for both long and short chain polymeric materials. The deformation processes in different polymeric materials show striking dissimilarities in spite of the common propylene matrix. Additionally, the deformation behavior of long and their respective short chain polymers was different. Deformation mechanisms include crazing/tearing, wedging, ductile ploughing, fibrillation, and brittle fracture. The different modes of deformation are depicted in the form of strain rate-strain diagrams. At a constant strain rate, the strain to fracture follows the sequence: high crystallinity polypropylenes< low crystallinity polypropylenes< ethylene-propylene di-block copolymers, indicative of the trend in resistance to plastic deformation

Data mining in bone marrow transplant records to identify patients with high odds of survival.

Science.gov (United States)

Taati, Babak; Snoek, Jasper; Aleman, Dionne; Ghavamzadeh, Ardeshir

2014-01-01

Patients undergoing a bone marrow stem cell transplant (BMT) face various risk factors. Analyzing data from past transplants could enhance the understanding of the factors influencing success. Records up to 120 measurements per transplant procedure from 1751 patients undergoing BMT were collected (Shariati Hospital). Collaborative filtering techniques allowed the processing of highly sparse records with 22.3% missing values. Ten-fold cross-validation was used to evaluate the performance of various classification algorithms trained on predicting the survival status. Modest accuracy levels were obtained in predicting the survival status (AUC = 0.69). More importantly, however, operations that had the highest chances of success were shown to be identifiable with high accuracy, e.g., 92% or 97% when identifying 74 or 31 recipients, respectively. Identifying the patients with the highest chances of survival has direct application in the prioritization of resources and in donor matching. For patients where high-confidence prediction is not achieved, assigning a probability to their survival odds has potential applications in probabilistic decision support systems and in combination with other sources of information.

A novel three-dimensional mesh deformation method based on sphere relaxation

International Nuclear Information System (INIS)

Zhou, Xuan; Li, Shuixiang

2015-01-01

In our previous work (2013) [19], we developed a disk relaxation based mesh deformation method for two-dimensional mesh deformation. In this paper, the idea of the disk relaxation is extended to the sphere relaxation for three-dimensional meshes with large deformations. We develop a node based pre-displacement procedure to apply initial movements on nodes according to their layer indices. Afterwards, the nodes are moved locally by the improved sphere relaxation algorithm to transfer boundary deformations and increase the mesh quality. A three-dimensional mesh smoothing method is also adopted to prevent the occurrence of the negative volume of elements, and further improve the mesh quality. Numerical applications in three-dimension including the wing rotation, bending beam and morphing aircraft are carried out. The results demonstrate that the sphere relaxation based approach generates the deformed mesh with high quality, especially regarding complex boundaries and large deformations

A novel three-dimensional mesh deformation method based on sphere relaxation

Energy Technology Data Exchange (ETDEWEB)

Zhou, Xuan [Department of Mechanics & Engineering Science, College of Engineering, Peking University, Beijing, 100871 (China); Institute of Applied Physics and Computational Mathematics, Beijing, 100094 (China); Li, Shuixiang, E-mail: lsx@pku.edu.cn [Department of Mechanics & Engineering Science, College of Engineering, Peking University, Beijing, 100871 (China)

2015-10-01

In our previous work (2013) [19], we developed a disk relaxation based mesh deformation method for two-dimensional mesh deformation. In this paper, the idea of the disk relaxation is extended to the sphere relaxation for three-dimensional meshes with large deformations. We develop a node based pre-displacement procedure to apply initial movements on nodes according to their layer indices. Afterwards, the nodes are moved locally by the improved sphere relaxation algorithm to transfer boundary deformations and increase the mesh quality. A three-dimensional mesh smoothing method is also adopted to prevent the occurrence of the negative volume of elements, and further improve the mesh quality. Numerical applications in three-dimension including the wing rotation, bending beam and morphing aircraft are carried out. The results demonstrate that the sphere relaxation based approach generates the deformed mesh with high quality, especially regarding complex boundaries and large deformations.

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)

Hot Deformation Behavior of SiCP/A1-Cu Composite

Directory of Open Access Journals (Sweden)

CHENG Ming-yang

2017-02-01

Full Text Available Using the Gleeble-1500D simulator, the high temperature plastic deformation behavior of SiCp/Al-Cu composite were investigated at 350-500℃ with the strain rate of 0.01-10s-1. The true stress-strain curves were obtained in the tests. Constitutive equation and processing map were established. The results show that the softening mechanism of dynamic recrystallization is a feature of high-temperature flow stress-strain curves of SiCp/A1-Cu composite, and the peak stress increases with the decrease of deformation temperature or the increase of strain rate.The flow stress behavior of the composite during hot compression deformation can be represented by a Zener-Hollomon parameter in the hyperbolic sine form. Its activation energy for hot deformation Q is 320.79kJ/mol. The stable regions and the instability regions in the processing map were identified and the microstructures in different regions of processing map were studied.There are particle breakage and void in the instability regions.

Particle deposition and deformation from high speed impaction of Ag nanoparticles

International Nuclear Information System (INIS)

Chitrakar, T.V.; Keto, J.W.; Becker, M.F.; Kovar, D.

2017-01-01

The impaction of a single Ag nanoparticle onto an (001) Ag substrate was studied as a function of particle diameter (2–9 nm) and impaction velocity (10–1500 m/sec) using molecular dynamics simulations. The final crystallographic structures were observed to transition from a polycrystalline to an epitaxial morphology as impaction velocity was increased and the velocity required to achieve epitaxy increased with particle size. To understand how the crystallographic structures evolved to their final state, the deformation mechanisms were then studied over a range of time scales, beginning immediately upon impaction. The observed mechanisms included disordering of the atoms and the initiation and propagation of partial dislocations. Deformation increased with impaction velocity due to increases in the degree of disordering and the partial dislocation density. At longer time scales, relaxation of the disordered particles produced epitaxial morphologies, whereas polycrystalline morphologies were observed following incomplete disordering. These results suggest that the microstructures of thick films produced by high speed impaction of nanoparticle aerosols are strongly influenced by processing parameters.

PARITY ODD BUBBLES IN HOT QCD

International Nuclear Information System (INIS)

KHARZEEV, D.; PISARSKI, R.D.; TYTGAT, M.H.G.

1998-01-01

We consider the topological susceptibility for an SU(N) gauge theory in the limit of a large number of colors, N r a rrow ∞. At nonzero temperature, the behavior of the topological susceptibility depends upon the order of the deconfining phase transition. The most interesting possibility is if the deconfining transition, at T = T d , is of second order. Then we argue that Witten's relation implies that the topological susceptibility vanishes in a calculable fashion at Td. As noted by Witten, this implies that for sufficiently light quark masses, metastable states which act like regions of nonzero θ--parity odd bubbles--can arise at temperatures just below T d . Experimentally, parity odd bubbles have dramatic signatures: the ηprime meson, and especially the η meson, become light, and are copiously produced. Further, in parity odd bubbles, processes which are normally forbidden, such as η r a rrow π 0 π 0 , are allowed. The most direct way to detect parity violation is by measuring a parity odd global asymmetry for charged pions, which we define

Deformable paper origami optoelectronic devices

KAUST Repository

He, Jr-Hau

2017-01-19

Deformable optoelectronic devices are provided, including photodetectors, photodiodes, and photovoltaic cells. The devices can be made on a variety of paper substrates, and can include a plurality of fold segments in the paper substrate creating a deformable pattern. Thin electrode layers and semiconductor nanowire layers can be attached to the substrate, creating the optoelectronic device. The devices can be highly deformable, e.g. capable of undergoing strains of 500% or more, bending angles of 25° or more, and/or twist angles of 270° or more. Methods of making the deformable optoelectronic devices and methods of using, e.g. as a photodetector, are also provided.

Sigma decomposition: the CP-odd Lagrangian

Energy Technology Data Exchange (ETDEWEB)

Hierro, I.M. [Dipartimento di Fisica “G. Galilei”, Università di Padova and INFN, Sezione di Padova,Via Marzolo 8, I-35131 Padua (Italy); Merlo, L. [Instituto de Física Teórica, IFT-UAM/CSIC, Universidad Autónoma de Madrid,Cantoblanco, 28049, Madrid (Spain); Rigolin, S. [Dipartimento di Fisica “G. Galilei”, Università di Padova and INFN, Sezione di Padova,Via Marzolo 8, I-35131 Padua (Italy)

2016-04-04

In Alonso et al., http://dx.doi.org/10.1007/JHEP12(2014)034, the CP-even sector of the effective chiral Lagrangian for a generic composite Higgs model with a symmetric coset has been constructed, up to four momenta. In this paper, the CP-odd couplings are studied within the same context. If only the Standard Model bosonic sources of custodial symmetry breaking are considered, then at most six independent operators form a basis. One of them is the weak-θ term linked to non-perturbative sources of CP violation, while the others describe CP-odd perturbative couplings between the Standard Model gauge bosons and an Higgs-like scalar belonging to the Goldstone boson sector. The procedure is then applied to three distinct exemplifying frameworks: the original SU(5)/SO(5) Georgi-Kaplan model, the minimal custodial-preserving SO(5)/SO(4) model and the minimal SU(3)/(SU(2)×U(1)) model, which intrinsically breaks custodial symmetry. Moreover, the projection of the high-energy electroweak effective theory to the low-energy chiral effective Lagrangian for a dynamical Higgs is performed, uncovering strong relations between the operator coefficients and pinpointing the differences with the elementary Higgs scenario.

A study on laser welding deformation of 304 stainless steel

International Nuclear Information System (INIS)

Kitagawa, Akikazu; Maehara, Kenji; Takeda, Shinnosuke; Matsunawa, Akira

2002-01-01

In heavy industries, 304 austenitic stainless steel is the most popular material which is used for nuclear equipment, chemical vessels, vacuum vessels and so on. On the fabrication, not only a joint quality but also severe dimensional accuracy is required. To keep dimensional accuracy, considerable cost and efforts are requested, because the welding deformation of austenitic stainless steel is deeply depended on the physical properties of material itself. To decrease welding deformation, big jigs or water cooling method are commonly used which lead to the high cost. In general, the fusion welding by high energy density heat source results in less distortion. Today, laser welding technology has grown up to the stage that enables to weld thick plate with small deformation. The researches of welding deformation have been conducted intensively, but they are mainly concerned for arc welding, and studies for laser welding are very few. In this report, the authors will show the test results of deformation behavior in laser welding of 304 stainless steel. Also, they will discuss the deformation behavior comparing to that in arc welding. The main results of this study are as follows. 1. The angular distortion of laser welding can be unified by heat input parameter (Hp) which is used for arc welding deformation. 2. The angular distortion are same under the condition of Hp 3 in spite of different welding method, however under the condition of Hp>6-9 J/mm 3 the angular distortion is quite different depending on the power density of welding method. 3. Pure angular distortion seemed to complete just after welding, but following longitudinal distortion took place for long period. 4. The critical value of longitudinal distortion can be estimated from heat input parameter. The transverse deformation can be also estimated by heat input parameter. (author)

Hybrid High-Order methods for finite deformations of hyperelastic materials

Science.gov (United States)

Abbas, Mickaël; Ern, Alexandre; Pignet, Nicolas

2018-01-01

We devise and evaluate numerically Hybrid High-Order (HHO) methods for hyperelastic materials undergoing finite deformations. The HHO methods use as discrete unknowns piecewise polynomials of order k≥1 on the mesh skeleton, together with cell-based polynomials that can be eliminated locally by static condensation. The discrete problem is written as the minimization of a broken nonlinear elastic energy where a local reconstruction of the displacement gradient is used. Two HHO methods are considered: a stabilized method where the gradient is reconstructed as a tensor-valued polynomial of order k and a stabilization is added to the discrete energy functional, and an unstabilized method which reconstructs a stable higher-order gradient and circumvents the need for stabilization. Both methods satisfy the principle of virtual work locally with equilibrated tractions. We present a numerical study of the two HHO methods on test cases with known solution and on more challenging three-dimensional test cases including finite deformations with strong shear layers and cavitating voids. We assess the computational efficiency of both methods, and we compare our results to those obtained with an industrial software using conforming finite elements and to results from the literature. The two HHO methods exhibit robust behavior in the quasi-incompressible regime.

PARITY ODD BUBBLES IN HOT QCD.

Energy Technology Data Exchange (ETDEWEB)

KHARZEEV,D.; PISARSKI,R.D.; TYTGAT,M.H.G.

1998-04-16

We consider the topological susceptibility for an SU(N) gauge theory in the limit of a large number of colors, N {r_arrow} {infinity}. At nonzero temperature, the behavior of the topological susceptibility depends upon the order of the deconfining phase transition. The most interesting possibility is if the deconfining transition, at T = T{sub d}, is of second order. Then we argue that Witten's relation implies that the topological susceptibility vanishes in a calculable fashion at Td. As noted by Witten, this implies that for sufficiently light quark masses, metastable states which act like regions of nonzero {theta}--parity odd bubbles--can arise at temperatures just below T{sub d}. Experimentally, parity odd bubbles have dramatic signatures: the {eta}{prime} meson, and especially the {eta} meson, become light, and are copiously produced. Further, in parity odd bubbles, processes which are normally forbidden, such as {eta} {r_arrow} {pi}{sup 0}{pi}{sup 0}, are allowed. The most direct way to detect parity violation is by measuring a parity odd global asymmetry for charged pions, which we define.

Holocene deformation offshore Ventura basin, CA, constrained by new high-resolution geophysical data

Science.gov (United States)

Perea, H.; Ucarkus, G.; Driscoll, N. W.; Kent, G. M.; Levy, Y.; Rockwell, T. K.

2017-12-01

The Transverse Ranges (Southern California, USA) accommodate the contraction resulting from a regional restraining bend in the San Andreas Fault to form a thrust-and-fold belt system. The southern boundary of this system corresponds to the E-W trending Ventura basin, which is filled by more than 5 km of Pleistocene sediment and is shortening at about 10 mm/yr as inferred from geodetic data. Although the different thrust and folds are fairly well known in the onshore areas of the basin, there is still uncertainty about their continuation in the offshore. The analysis of new high-resolution (SIO CHIRP) and existing (USGS sparker and chirp) seismic data has allowed us to characterize better the active geological structures in the offshore. In the dataset, we have identified different latest Quaternary seismostratigraphic units and horizons, with the most regionally recognized being a transgressive surface (LGTS) associated to the Last Glacial maximum and subsequent sea level rise. A series of E-W regional folds related to thrust faults have deformed the LGTS producing highs and depressions. The correlation of these structures between profiles shows that they are elongated and parallel between them and continue to the coastline. In addition, considering their trend and kinematics, we have been able to tie them with the main onshore active thrusts and folds. Above the LGTS we have identified progradational and agradational units that are related to global sea level rise, which exhibit less deformation (folding and faulting) than the lower units and horizons. However, we have recognized some specific fold growth sequences above LGTS associated with the activity of different thrust-related anticlines. Accordingly, we have identified between 3 and 5 tectonic deformation events (e.g., earthquakes) associated to thrust fault activity. These results may help us to determine the deformation history for the offshore Ventura basin and the potentiality of the thrust faults that

Quantification of the microstructures of high purity nickel subjected to dynamic plastic deformation

DEFF Research Database (Denmark)

Luo, Z.P.; Zhang, H.W.; Hansen, Niels

2012-01-01

and the misorientation angle across dislocation boundaries and high angle boundaries. These boundaries subdivide the structure on a finer and finer scale towards saturation at the highest strain. The structural evolution follows a hierarchical pattern from the formation of cells and cell blocks to a characteristic...... and high angle boundaries. Shear bands and twins have not been observed. In order to underpin the structural analysis, the mechanical properties as a function of strain have been determined by tensile and hardness tests. The flow stress is 850 MPa, showing that high strain rate deformation has potential...

The odd Voigt effect under a strong electric field in semiconductors

International Nuclear Information System (INIS)

Nguyen Hong Shon.

1991-08-01

The high frequency conductivity tensor σ ik (ω) in the linear approximation of magnetic field H and in the quadratic approximation of external dc electric field is derived by solving Boltzmann equation. The magneto-optical phenomena in the Voigt configuration (when a probe electro-magnetic wave propagates across a magnetic field) are investigated. It is shown that the birefringence and dichroism have a component that is odd (linear) in the magnetic fields and predominate over the even effect in the weak magnetic field. (author). 8 refs

Deformation mechanisms induced under high cycle fatigue tests in a metastable austenitic stainless steel

Energy Technology Data Exchange (ETDEWEB)

Roa, J.J., E-mail: joan.josep.roa@upc.edu [CIEFMA-Departament de Ciència dels Materials i Enginyeria Metallúrgica, ETSEIB, Universitat Politècnica de Catalunya, Avda. Diagonal 647, 08028 Barcelona (Spain); CRnE, Campus Diagonal Sud, Edificio C’, Universitat Politècnica de Catalunya, C/ Pascual i Vila 15, 08028 Barcelona (Spain); Fargas, G. [CIEFMA-Departament de Ciència dels Materials i Enginyeria Metallúrgica, ETSEIB, Universitat Politècnica de Catalunya, Avda. Diagonal 647, 08028 Barcelona (Spain); Jiménez-Piqué, E. [CIEFMA-Departament de Ciència dels Materials i Enginyeria Metallúrgica, ETSEIB, Universitat Politècnica de Catalunya, Avda. Diagonal 647, 08028 Barcelona (Spain); CRnE, Campus Diagonal Sud, Edificio C’, Universitat Politècnica de Catalunya, C/ Pascual i Vila 15, 08028 Barcelona (Spain); Mateo, A. [CIEFMA-Departament de Ciència dels Materials i Enginyeria Metallúrgica, ETSEIB, Universitat Politècnica de Catalunya, Avda. Diagonal 647, 08028 Barcelona (Spain)

2014-03-01

Advanced techniques were used to study the deformation mechanisms induced by fatigue tests in a metastable austenitic stainless steel AISI 301LN. Observations by Atomic Force Microscopy were carried out to study the evolution of a pre-existing martensite platelet at increasing number of cycles. The sub-superficial deformation mechanisms of the austenitic grains were studied considering the cross-section microstructure obtained by Focused Ion Beam and analysed by Scanning Electron Microscopy and Transmission Electron Microscopy. The results revealed no deformation surrounding the pre-existing martensitic platelet during fatigue tests, only the growth on height was observed. Martensite formation was associated with shear bands on austenite, mainly in the {111} plane, and with the activation of the other intersecting austenite {111}〈110〉 slip system. Furthermore, transmission electron microscopy results showed that the nucleation of ε-martensite follows a two stages phase transformation (γ{sub fcc}→ε{sub hcp}→α'{sub bcc})

Thermomechanical characterization of a membrane deformable mirror

International Nuclear Information System (INIS)

Morse, Kathleen A.; McHugh, Stuart L.; Fixler, Jeff

2008-01-01

A membrane deformable mirror has been investigated for its potential use in high-energy laser systems. Experiments were performed in which the deformable mirror was heated with a 1 kW incandescent lamp and the thermal profile, the wavefront aberrations, and the mechanical displacement of the membrane were measured. A finite element model was also developed. The wavefront characterization experiments showed that the wavefront degraded with heating. Above a temperature of 35 deg. C, the wavefront characterization experiments indicated a dramatic increase in the high-order wavefront modes before the optical beam became immeasurable in the sensors. The mechanical displacement data of the membrane mirror showed that during heating, the membrane initially deflected towards the heat source and then deflected away from the heat source. Finite element analysis (FEA) predicted a similar displacement behavior as shown by the mechanical displacement data but over a shorter time scale and a larger magnitude. The mechanical displacement data also showed that the magnitude of membrane displacement increased with the experiments that involved higher temperatures. Above a temperature of 35 deg. C, the displacement data showed that random deflections as a function of time developed and that the magnitude of these deflections increased with increased temperature. We concluded that convection, not captured in the FEA, likely played a dominant role in mirror deformation at temperatures above 35 deg. C

Stochastic deformation of a thermodynamic symplectic structure

OpenAIRE

Kazinski, P. O.

2008-01-01

A stochastic deformation of a thermodynamic symplectic structure is studied. The stochastic deformation procedure is analogous to the deformation of an algebra of observables like deformation quantization, but for an imaginary deformation parameter (the Planck constant). Gauge symmetries of thermodynamics and corresponding stochastic mechanics, which describes fluctuations of a thermodynamic system, are revealed and gauge fields are introduced. A physical interpretation to the gauge transform...

Effect of cold working and aging on high temperature deformation of high Mn stainless steel

International Nuclear Information System (INIS)

Yoshikawa, M.; Habara, Y.; Matsuki, R.; Aoyama, H.

1999-01-01

By the addition of N, the strength of high Mn stainless steel can be increased. Cold rolling and aging are effective to increase its strength further, and with those treatments this grade is often used for high temperature applications. In this study, creep deformation behavior and high temperature strength of the high Mn stainless steel in cold rolled and aged conditions are discussed as compared to Type 304 stainless steel. It has been revealed that as-rolled specimens show instant elongation at the beginning of creep tests and its amount is larger in the high Mn grade than in Type 304. Also, the creep rate of the high Mn stainless steel is smaller than that of Type 304. These facts may be related to the change in microstructure. (orig.)

Low-cost, portable, robust and high-resolution single-camera stereo-DIC system and its application in high-temperature deformation measurements

Science.gov (United States)

Chi, Yuxi; Yu, Liping; Pan, Bing

2018-05-01

A low-cost, portable, robust and high-resolution single-camera stereo-digital image correlation (stereo-DIC) system for accurate surface three-dimensional (3D) shape and deformation measurements is described. This system adopts a single consumer-grade high-resolution digital Single Lens Reflex (SLR) camera and a four-mirror adaptor, rather than two synchronized industrial digital cameras, for stereo image acquisition. In addition, monochromatic blue light illumination and coupled bandpass filter imaging are integrated to ensure the robustness of the system against ambient light variations. In contrast to conventional binocular stereo-DIC systems, the developed pseudo-stereo-DIC system offers the advantages of low cost, portability, robustness against ambient light variations, and high resolution. The accuracy and precision of the developed single SLR camera-based stereo-DIC system were validated by measuring the 3D shape of a stationary sphere along with in-plane and out-of-plane displacements of a translated planar plate. Application of the established system to thermal deformation measurement of an alumina ceramic plate and a stainless-steel plate subjected to radiation heating was also demonstrated.

Soil clay content underlies prion infection odds

Science.gov (United States)

David, Walter W.; Walsh, D.P.; Farnsworth, Matthew L.; Winkelman, D.L.; Miller, M.W.

2011-01-01

Environmental factors-especially soil properties-have been suggested as potentially important in the transmission of infectious prion diseases. Because binding to montmorillonite (an aluminosilicate clay mineral) or clay-enriched soils had been shown to enhance experimental prion transmissibility, we hypothesized that prion transmission among mule deer might also be enhanced in ranges with relatively high soil clay content. In this study, we report apparent influences of soil clay content on the odds of prion infection in free-ranging deer. Analysis of data from prion-infected deer herds in northern Colorado, USA, revealed that a 1% increase in the clay-sized particle content in soils within the approximate home range of an individual deer increased its odds of infection by up to 8.9%. Our findings suggest that soil clay content and related environmental properties deserve greater attention in assessing risks of prion disease outbreaks and prospects for their control in both natural and production settings. ?? 2011 Macmillan Publishers Limited. All rights reserved.

The quantum harmonic oscillator on a circle and a deformed quantum field theory

International Nuclear Information System (INIS)

Rego-Monteiro, M.A.

2001-05-01

We construct a deformed free quantum field theory with an standard Hilbert space based on a deformed Heisenberg algebra. This deformed algebra is a Heisenberg-type algebra describing the first levels of the quantum harmonic oscillator on a circle of large length L. The successive energy levels of this quantum harmonic oscillator on a circle of large length L are interpreted, similarly to the standard quantum one-dimensional harmonic oscillator on an infinite line, as being obtained by the creation of a quantum particle of frequency w at very high energies. (author)

The unexpected stability of multiwall nanotubes under high pressure and shear deformation

International Nuclear Information System (INIS)

Pashkin, E. Y.; Pankov, A. M.; Kulnitskiy, B. A.; Mordkovich, V. Z.; Perezhogin, I. A.; Karaeva, A. R.; Popov, M. Y.; Sorokin, P. B.; Blank, V. D.

2016-01-01

The behavior of multiwall carbon nanotubes under a high pressure (up to 55 GPa) combined with shear deformation was studied by experimental and theoretical methods. The unexpectedly high stability of the nanotubes' structure under high stresses was observed. After the pressure was released, we observed that the nanotubes had restored their shapes. Atomistic simulations show that the hydrostatic and shear stresses affect the nanotubes' structure in a different way. It was found that the shear stress load in the multiwall nanotubes' outer walls can induce their connection and formation of an amorphized sp"3-hybridized region but internal core keeps the tubular structure.

The unexpected stability of multiwall nanotubes under high pressure and shear deformation

Energy Technology Data Exchange (ETDEWEB)

Pashkin, E. Y.; Pankov, A. M.; Kulnitskiy, B. A.; Mordkovich, V. Z. [Technological Institute for Superhard and Novel Carbon Materials, 7a Centralnaya Street, Troitsk, Moscow 142190 (Russian Federation); Moscow Institute of Physics and Technology, 9 Institutsky Lane, Dolgoprudny 141700 (Russian Federation); Perezhogin, I. A. [Technological Institute for Superhard and Novel Carbon Materials, 7a Centralnaya Street, Troitsk, Moscow 142190 (Russian Federation); Lomonosov Moscow State University, Leninskie Gory, Moscow 119991 (Russian Federation); Karaeva, A. R. [Technological Institute for Superhard and Novel Carbon Materials, 7a Centralnaya Street, Troitsk, Moscow 142190 (Russian Federation); Popov, M. Y.; Sorokin, P. B.; Blank, V. D. [Technological Institute for Superhard and Novel Carbon Materials, 7a Centralnaya Street, Troitsk, Moscow 142190 (Russian Federation); Moscow Institute of Physics and Technology, 9 Institutsky Lane, Dolgoprudny 141700 (Russian Federation); National University of Science and Technology MISiS, 4 Leninskiy Prospekt, Moscow 119049 (Russian Federation)

2016-08-22

The behavior of multiwall carbon nanotubes under a high pressure (up to 55 GPa) combined with shear deformation was studied by experimental and theoretical methods. The unexpectedly high stability of the nanotubes' structure under high stresses was observed. After the pressure was released, we observed that the nanotubes had restored their shapes. Atomistic simulations show that the hydrostatic and shear stresses affect the nanotubes' structure in a different way. It was found that the shear stress load in the multiwall nanotubes' outer walls can induce their connection and formation of an amorphized sp{sup 3}-hybridized region but internal core keeps the tubular structure.

Comparative analysis of perioperative complications between a multicenter prospective cervical deformity database and the Nationwide Inpatient Sample database.

Science.gov (United States)

Passias, Peter G; Horn, Samantha R; Jalai, Cyrus M; Poorman, Gregory; Bono, Olivia J; Ramchandran, Subaraman; Smith, Justin S; Scheer, Justin K; Sciubba, Daniel M; Hamilton, D Kojo; Mundis, Gregory; Oh, Cheongeun; Klineberg, Eric O; Lafage, Virginie; Shaffrey, Christopher I; Ames, Christopher P

2017-11-01

Complication rates for adult cervical deformity are poorly characterized given the complexity and heterogeneity of cases. To compare perioperative complication rates following adult cervical deformity corrective surgery between a prospective multicenter database for patients with cervical deformity (PCD) and the Nationwide Inpatient Sample (NIS). Retrospective review of prospective databases. A total of 11,501 adult patients with cervical deformity (11,379 patients from the NIS and 122 patients from the PCD database). Perioperative medical and surgical complications. The NIS was queried (2001-2013) for cervical deformity discharges for patients ≥18 years undergoing cervical fusions using International Classification of Disease, Ninth Revision (ICD-9) coding. Patients ≥18 years from the PCD database (2013-2015) were selected. Equivalent complications were identified and rates were compared. Bonferroni correction (pdatabases. A total of 11,379 patients from the NIS database and 122 patiens from the PCD database were identified. Patients from the PCD database were older (62.49 vs. 55.15, pdatabase. The PCD database had an increased risk of reporting overall complications than the NIS (odds ratio: 2.81, confidence interval: 1.81-4.38). Only device-related complications were greater in the NIS (7.1% vs. 1.1%, p=.007). Patients from the PCD database displayed higher rates of the following complications: peripheral vascular (0.8% vs. 0.1%, p=.001), gastrointestinal (GI) (2.5% vs. 0.2%, pdatabases (p>.004). Based on surgicalapproach, the PCD reported higher GI and neurologic complication rates for combined anterior-posterior procedures (pdatabase revealed higher overall and individual complication rates and higher data granularity. The nationwide database may underestimate complications of patients with adult cervical deformity (ACD) particularly in regard to perioperative surgical details owing to coding and deformity generalizations. The surgeon-maintained database

Glacio-tectonic thrust and deformation structures in the Vejle Fjord, Denmark revealed by high-resolution subbottom-profile data

DEFF Research Database (Denmark)

Andresen, Katrine Juul; Boldreel, Lars Ole; Wahlgreen, Katrine Bak

Surface geomorphological features and partial cliff exposures up till now represent the predominant source of information of glaciation related deformation in Denmark. In this study we apply high-resolution marine reflection seismic data from the Vejle Fjord area, supported by gravity and Rumohr...... coring, to document intense glacio-tectonic deformation in the shallow subsurface of Denmark. The subbottom profiler seismic data have a peak frequency around 13 kHz and a vertical resolution in the order of 10-20 cm. The data reveal several variations of glacio-tectonic deformation structures, primarily...... movements from outcrops and shallow cores. The subbottom profiler data provides larger (longer and deeper) sectional views on for instance deformation and deposition complexes related to ice progressions and retreats and thus represents a very good supplement and valuable input to field mapping and outcrops...

Developing a Virtual Rock Deformation Laboratory

Science.gov (United States)

Zhu, W.; Ougier-simonin, A.; Lisabeth, H. P.; Banker, J. S.

2012-12-01

Experimental rock physics plays an important role in advancing earthquake research. Despite its importance in geophysics, reservoir engineering, waste deposits and energy resources, most geology departments in U.S. universities don't have rock deformation facilities. A virtual deformation laboratory can serve as an efficient tool to help geology students naturally and internationally learn about rock deformation. Working with computer science engineers, we built a virtual deformation laboratory that aims at fostering user interaction to facilitate classroom and outreach teaching and learning. The virtual lab is built to center around a triaxial deformation apparatus in which laboratory measurements of mechanical and transport properties such as stress, axial and radial strains, acoustic emission activities, wave velocities, and permeability are demonstrated. A student user can create her avatar to enter the virtual lab. In the virtual lab, the avatar can browse and choose among various rock samples, determine the testing conditions (pressure, temperature, strain rate, loading paths), then operate the virtual deformation machine to observe how deformation changes physical properties of rocks. Actual experimental results on the mechanical, frictional, sonic, acoustic and transport properties of different rocks at different conditions are compiled. The data acquisition system in the virtual lab is linked to the complied experimental data. Structural and microstructural images of deformed rocks are up-loaded and linked to different deformation tests. The integration of the microstructural image and the deformation data allows the student to visualize how forces reshape the structure of the rock and change the physical properties. The virtual lab is built using the Game Engine. The geological background, outstanding questions related to the geological environment, and physical and mechanical concepts associated with the problem will be illustrated on the web portal. In

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.

Direct observation of radial distribution change during tensile deformation of metallic glass by high energy X-ray diffraction method

Energy Technology Data Exchange (ETDEWEB)

Nasu, Toshio, E-mail: nasu@kekexafs.kj.yamagata-u.ac.j [Faculty of Education, Arts and Science, Yamagata University, 1-4-12 Kojirakawa, Yamagata, Yamagata, 990-8560 (Japan); Sasaki, Motokatsu [Faculty of Education, Arts and Science, Yamagata University, 1-4-12 Kojirakawa, Yamagata, Yamagata, 990-8560 (Japan); Usuki, Takeshi; Sekine, Mai [Faculty of Science, Yamagata University, Yamagata 990-8560 (Japan); Takigawa, Yorinobu; Higashi, Kenji [Graduate School of Engineering, Osaka Prefecture University, Sakai 599-8531 (Japan); Kohara, Shinji [Japan Synchrotron Radiation Research Institute, Harima Science Garden City, Sayo town, Hyogo 679-5198 (Japan); Sakurai, Masaki; Wei Zhang; Inoue, Akihisa [Institute for Materials Research, Tohoku University, Sendai 980-8577 (Japan)

2009-08-26

The purpose of this research is to investigate the micro-mechanism of deformation behavior of metallic glasses. We report the results of direct observations of short-range and medium-range structural change during tensile deformation of metallic glasses by high energy X-ray diffraction method. Cu{sub 50}Zr{sub 50} and Ni{sub 30}Zr{sub 70} metallic glass samples in the ribbon shape (1.5 mm width and 25 mum) were made by using rapid quenching method. Tensile deformation added to the sample was made by using special equipment adopted for measuring the high energy X-ray diffraction. The peaks in pair distribution function g(r) for Cu{sub 50}Zr{sub 50} and N{sub 30}iZr{sub 70} metallic glasses move zigzag into front and into rear during tensile deformation. These results of direct observation on atomic distribution change for Cu{sub 50}Zr{sub 50} and Ni{sub 30}Zr{sub 70} metallic glass ribbons during tensile deformation suggest that the micro-relaxations occur.

Noise Characteristics of High-Rate Multi-GNSS for Subdaily Crustal Deformation Monitoring

Science.gov (United States)

Geng, Jianghui; Pan, Yuanxin; Li, Xiaotao; Guo, Jiang; Liu, Jingnan; Chen, Xianchun; Zhang, Yong

2018-02-01

High-rate GPS (Global Positioning System) has the potential to record crustal motions on a wide subdaily timescale from seconds to hours but usually fails to capture subtle deformations which are often overwhelmed by the centimeter noise of epoch-wise GPS displacements. We hence investigated high-rate multi-GNSS (Global Navigation Satellite System) by processing 1 Hz GPS/GLONASS/BeiDou data at 15 static stations over 24 days and also those from the 8 August 2017 Jiuzhaigou Mw 6.5 earthquake. In contrast to high-rate GPS, its further integration with GLONASS/BeiDou reduces near uniformly the power spectral densities (PSDs) of 1 Hz displacement noise by 4-6 dB over the periods from a few seconds to half of a day, and orbital repeat time (ORT) filtering on all GNSS further again leads to a 2 more decibel decline of the PSDs over the periods of a few tens of seconds to minutes. BeiDou ORT filtering, however, takes effect mainly on the periods of over 2,000 s due to the high altitudes of Inclined Geosynchronous Satellite Orbiters/Geosynchronous Earth Orbiters. Multi-GNSS integration is on average as effective as GPS ORT filtering in reducing PSDs for the periods of a few tens of seconds to minutes while desirably can further decrease the PSDs on almost all other periods by 3-4 dB thanks to the enhanced satellite geometry. We conclude that the introduction of more GNSS into high-rate solutions and its augmentation by ORT filtering benefit the discrimination of slight deformations over a broad subdaily frequency band.

Oppositional defiant disorder (ODD), the forerunner of alcohol dependence: a controlled study.

Science.gov (United States)

Ghosh, Abhishek; Malhotra, Savita; Basu, Debasish

2014-10-01

There are common genetic, neurobiological and psycho-social substrates for oppositional defiant disorder (ODD) and substance dependence. ODD can be regarded as the mildest and earliest form of disruptive behavioral disorder and also represents the threshold of vulnerability for substance dependence. But it is a less researched area. The aim of this research was to study any possible association between childhood ODD and adult alcohol dependence. Data are presented from a non probability sample of 100 adult alcohol dependent subjects and equal number of biologically unrelated control subjects. Assessment was conducted by the instrument Semi-Structured Assessment for the Genetics of Alcoholism for both the assessment of ODD and alcohol dependence. The results of this study demonstrated significant association between childhood ODD and adult alcohol dependence. The association remained significant even after the exclusion of the possible confounding effects of the presence of conduct disorder and attention deficit hyperactivity disorder. Our study should encourage further research in this area and is expected to open up an opportunity for preventive research. Copyright © 2014 Elsevier B.V. All rights reserved.

BKP and CKP revisited: the odd KP system

International Nuclear Information System (INIS)

Dimakis, Aristophanes; Müller-Hoissen, Folkert

2009-01-01

By restricting a linear system for the KP hierarchy to those independent variables t n with odd n, its compatibility (Zakharov-Shabat conditions) leads to the 'odd KP hierarchy'. The latter consists of pairs of equations for two dependent variables, taking values in an (typically noncommutative) associative algebra. If the algebra is commutative, the odd KP hierarchy is known to admit reductions to the BKP and the CKP hierarchy. We approach the odd KP hierarchy and its relation to BKP and CKP in different ways, and address the question of whether noncommutative versions of the BKP and the CKP equation (and some of their reductions) exist. In particular, we derive a functional representation of a linear system for the odd KP hierarchy, which in the commutative case produces functional representations of the BKP and CKP hierarchies in terms of a tau function. Furthermore, we consider a functional representation of the KP hierarchy that involves a second (auxiliary) dependent variable and features the odd KP hierarchy directly as a subhierarchy. A method to generate large classes of exact solutions to the KP hierarchy from solutions to a linear matrix ODE system, via a hierarchy of matrix Riccati equations, then also applies to the odd KP hierarchy, and this in turn can be exploited, in particular, to obtain solutions to the BKP and CKP hierarchies

Mathematical modeling of phenomena of dynamic recrystallization during hot plastic deformation in high-carbon bainitic steel

Directory of Open Access Journals (Sweden)

T. Dembiczak

2017-01-01

Full Text Available Based on the research results, coefficients were determined in constitutive equations, describing the kinetics of dynamic recrystallization in high-carbon bainitic steel during hot deformation. The developed mathematical model takes into account the dependence of changing kinetics in the size evolution of the initial austenite grains, the value of strain, strain rate, temperature and time. Physical simulations were carried out on rectangular specimens measuring 10 × 15 × 20 mm. Compression tests with a plane state of deformation were carried out using a Gleeble 3800.

On the role of high multipolarity interactions in deformed nuclei

International Nuclear Information System (INIS)

Solov'ev, V.G.; Sushkov, A.V.

1989-01-01

The influence of interactions with the multipolarity λ=5,6,7 and 9 is studied on the mixing of two-quasineutron and two-quasineutron states with large K in doubly even deformed nuclei. The mixing of the two-quasineutron and two-quasiproton states with the same values of K π , caused by a high multipolarity interaction, is shown to be large in the case of proximity of their energies. Qualitatively correct description of experimental data on the mixing of two-quasineutron and two-quasiproton configurations in 178,176 Hf, 174 Yb, 168 Er and 158 Gd is obtained. 20 refs.; 1 tab

Aluminium. II - A review of deformation properties of high purity aluminium and dilute aluminium alloys.

Science.gov (United States)

Reed, R. P.

1972-01-01

The elastic and plastic deformation behavior of high-purity aluminum and of dilute aluminum alloys is reviewed. Reliable property data, including elastic moduli, elastic coefficients, tensile, creep, fatigue, hardness, and impact are presented. Single crystal tensile results are discussed. Rather comprehensive reference lists, containing publications of the past 20 years, are included for each of the above categories. Defect structures and mechanisms responsible for mechanical behavior are presented. Strengthening techniques (alloys, cold work, irradiation, quenching, composites) and recovery are briefly reviewed.

The evens and odds of CMB anomalies

Science.gov (United States)

Gruppuso, A.; Kitazawa, N.; Lattanzi, M.; Mandolesi, N.; Natoli, P.; Sagnotti, A.

2018-06-01

The lack of power of large-angle CMB anisotropies is known to increase its statistical significance at higher Galactic latitudes, where a string-inspired pre-inflationary scale Δ can also be detected. Considering the Planck 2015 data, and relying largely on a Bayesian approach, we show that the effect is mostly driven by the even - ℓ harmonic multipoles with ℓ ≲ 20, which appear sizably suppressed in a way that is robust with respect to Galactic masking, along with the corresponding detections of Δ. On the other hand, the first odd - ℓ multipoles are only suppressed at high Galactic latitudes. We investigate this behavior in different sky masks, constraining Δ through even and odd multipoles, and we elaborate on possible implications. We include low- ℓ polarization data which, despite being noise-limited, help in attaining confidence levels of about 3 σ in the detection of Δ. We also show by direct forecasts that a future all-sky E-mode cosmic-variance-limited polarization survey may push the constraining power for Δ beyond 5 σ.

Confusion between Odds and Probability, a Pandemic?

Science.gov (United States)

Fulton, Lawrence V.; Mendez, Francis A.; Bastian, Nathaniel D.; Musal, R. Muzaffer

2012-01-01

This manuscript discusses the common confusion between the terms probability and odds. To emphasize the importance and responsibility of being meticulous in the dissemination of information and knowledge, this manuscript reveals five cases of sources of inaccurate statistical language imbedded in the dissemination of information to the general…

Deformation mechanisms in cyclic creep and fatigue

International Nuclear Information System (INIS)

Laird, C.

1979-01-01

Service conditions in which static and cyclic loading occur in conjunction are numerous. It is argued that an understanding of cyclic creep and cyclic deformation are necessary both for design and for understanding creep-fatigue fracture. Accordingly a brief, and selective, review of cyclic creep and cyclic deformation at both low and high strain amplitudes is provided. Cyclic loading in conjunction with static loading can lead to creep retardation if cyclic hardening occurs, or creep acceleration if softening occurs. Low strain amplitude cyclic deformation is understood in terms of dislocation loop patch and persistent slip band behavior, high strain deformation in terms of dislocation cell-shuttling models. While interesting advances in these fields have been made in the last few years, the deformation mechanisms are generally poorly understood

Effect of cold deformation on latent energy value and high-temperature mechanical properties of 12Cr18Ni10Ti steel

International Nuclear Information System (INIS)

Maksimkin, O.P.; Shiganakov, Sh.B.; Gusev, M.N.

1997-01-01

Energetic and magnetic characteristics and also the high-temperature mechanical properties depending on the preliminary cold deformation of 12Cr18Ni10Ti steel are presented. It is shown that the value of storage energy in the steel has being grown with increase of the deformation. The rate of its growth has been increased after beginning of martensitic γ→α'- transformation when value of comparative storage energy at first decreased and then has been stay practically constant. Level of mechanical properties of the steel at 1073 K has been determined not only by value of cold deformation but and structural reconstruction corresponding to deformations 35-45% and accompanying with α'-phase martensite formation and change of energy accumulating rate. Preliminary cold deformation (40-60 %) does not improve high- temperature plasticity of steel samples implanted by helium. refs. 7, figs. 2

Mechanisms of plastic deformation in highly cross-linked UHMWPE for total hip components--the molecular physics viewpoint.

Science.gov (United States)

Takahashi, Yasuhito; Shishido, Takaaki; Yamamoto, Kengo; Masaoka, Toshinori; Kubo, Kosuke; Tateiwa, Toshiyuki; Pezzotti, Giuseppe

2015-02-01

Plastic deformation is an unavoidable event in biomedical polymeric implants for load-bearing application during long-term in-vivo service life, which involves a mass transfer process, irreversible chain motion, and molecular reorganization. Deformation-induced microstructural alterations greatly affect mechanical properties and durability of implant devices. The present research focused on evaluating, from a molecular physics viewpoint, the impact of externally applied strain (or stress) in ultra-high molecular weight polyethylene (UHMWPE) prostheses, subjected to radiation cross-linking and subsequent remelting for application in total hip arthroplasty (THA). Two different types of commercial acetabular liners, which belong to the first-generation highly cross-linked UHMWPE (HXLPE), were investigated by means of confocal/polarized Raman microprobe spectroscopy. The amount of crystalline region and the spatial distribution of molecular chain orientation were quantitatively analyzed according to a combined theory including Raman selection rules for the polyethylene orthorhombic structure and the orientation distribution function (ODF) statistical approach. The structurally important finding was that pronounced recrystallization and molecular reorientation increasingly appeared in the near-surface regions of HXLPE liners with increasing the amount of plastic (compressive) deformation stored in the microstructure. Such molecular rearrangements, occurred in response to external strains, locally increase surface cross-shear (CS) stresses, which in turn trigger microscopic wear processes in HXLPE acetabular liners. Thus, on the basis of the results obtained at the molecular scale, we emphasize here the importance of minimizing the development of irrecoverable deformation strain in order to retain the pristine and intrinsically high wear performance of HXLPE components. Copyright © 2014 Elsevier Ltd. All rights reserved.

Improvement of computer programs 'BAMBOO' and 'ASFRE-IV' for coupling analysis of deformation and thermal-hydraulics in a high burn-up fuel subassembly of fast reactor

International Nuclear Information System (INIS)

Uwaba, Tomoyuki; Ohshima, Hiroyuki; Imai, Yasutomo

2003-04-01

A simulation system of a deformed fuel subassembly is being developed for the structure integrity of high burn-up wire-spacer-type fuel subassemblies of sodium-cooled fast breeder reactors. This report describes a computer program improvement work for coupling analyses of deformation and thermal-hydraulics in a fuel subassembly as part of the simulation system development. In this work, a function of data conversion as an interface between a bundle deformation analysis program BAMBOO and a thermal hydraulic analysis program ASFRE-IV was incorporated to each program. BAMBOO was improved to accept the coolant temperature data from ASFRE-IV and to offer bundle deformation data to ASFRE-IV. ASFRE-IV was also improved to offer the coolant temperature data to BAMBOO and to obtain the bundle deformation data from BAMBOO. Improved BAMBOO and ASFRE-IV were applied to an analysis of 169-pin bundle for the program verification. It was confirmed that the coupling analysis gave the physically reasonable results on both deformation and thermal hydraulic behaviors in the fuel subassembly. (author)

Level Density In Interacting Boson-Fermion-Fermion Model (IBFFM) Of The Odd-Odd Nucleus 196Au

International Nuclear Information System (INIS)

Kabashi, Skender; Bekteshi, Sadik

2007-01-01

The level density of the odd-odd nucleus 196Au is investigated in the interacting boson-fermion-fermion model (IBFFM) which accounts for collectivity and complex interaction between quasiparticle and collective modes.The IBFFM total level density is fitted by Gaussian and its tail is also fitted by Bethe formula and constant temperature Fermi gas model

Frequency of foot deformity in preschool girls

Directory of Open Access Journals (Sweden)

Mihajlović Ilona

2010-01-01

Full Text Available Background/Aim. In order to determine the moment of creation of postural disorders, regardless of the causes of this problem, it is necessary to examine the moment of entry of children into a new environment, ie. in kindergarten or school. There is a weak evidence about the age period when foot deformity occurs, and the type of these deformities. The aim of this study was to establish the relationship between the occurrence of foot deformities and age characteristics of girls. Methods. The research was conducted in preschools 'Radosno detinjstvo' in the region of Novi Sad, using the method of random selection, on the sample of 272 girls, 4-7 years of age, classified into four strata according to the year of birth. To determine the foot deformities measurement technique using computerized digitized pedografy (CDP was applied. Results. In preschool population girls pes transversoplanus and calcanei valga deformities occurred in a very high percentage (over 90%. Disturbed longitudinal instep ie flat feet also appeared in a high percentage, but we noted the improvement of this deformity according to increasing age. Namely, there was a statistically significant correlation between the age and this deformity. As a child grows older, the deformity is lower. Conclusion. This study confirmed that the formation of foot arches probably does not end at the age of 3-4 years but lasts until school age.

A mechanical deformation model of metallic fuel pin under steady state conditions

International Nuclear Information System (INIS)

Lee, D. W.; Lee, B. W.; Kim, Y. I.; Han, D. H.

2004-01-01

As a mechanical deformation model of the MACSIS code predicts the cladding deformation due to the simple thin shell theory, it is impossible to predict the FCMI(Fuel-Cladding Mechanical Interaction). Therefore, a mechanical deformation model used the generalized plane strain is developed. The DEFORM is a mechanical deformation routine which is used to analyze the stresses and strains in the fuel and cladding of a metallic fuel pin of LMRs. The accuracy of the program is demonstrated by comparison of the DEFORM predictions with the result of another code calculations or experimental results in literature. The stress/strain distributions of elastic part under free thermal expansion condition are completely matched with the results of ANSYS code. The swelling and creep solutions are reasonably well agreed with the simulations of ALFUS and LIFE-M codes, respectively. The predicted cladding strains are under estimated than experimental data at the range of high burnup. Therefore, it is recommended that the fine tuning of the DEFORM based on various range of experimental data

Energy spectra of odd nuclei in the generalized model

Directory of Open Access Journals (Sweden)

I. O. Korzh

2015-04-01

Full Text Available Based on the generalized nuclear model, energy spectra of the odd nuclei of such elements as 25Mg, 41K, and 65Cu are determined, and the structure of wave functions of these nuclei in the excited and normal states is studied. High quality in determining the energy spectra is possible due to the accurate calculations of all elements of the energy matrix. It is demonstrated that the structure of the wave functions so determined provides the possibility to more accurately select the nuclear model and the method for calculating the nucleon cross-sections of the inelastic scattering of nucleons by odd nuclei.

Deformation and Phase Transformation Processes in Polycrystalline NiTi and NiTiHf High Temperature Shape Memory Alloys

Science.gov (United States)

Benafan, Othmane

2012-01-01

The deformation and transformation mechanisms of polycrystalline Ni49.9Ti50.1 and Ni50.3Ti29.7Hf20 (in at.%) shape memory alloys were investigated by combined experimental and modeling efforts aided by an in situ neutron diffraction technique at stress and temperature. The thermomechanical response of the low temperature martensite, the high temperature austenite phases, and changes between these two states during thermomechanical cycling were probed and reported. In the cubic austenite phase, stress-induced martensite, deformation twinning and slip processes were observed which helped in constructing a deformation map that contained the limits over which each of the identified mechanisms was dominant. Deformation of the monoclinic martensitic phase was also investigated where the microstructural changes (texture, lattice strains, and phase fractions) during room-temperature deformation and subsequent thermal cycling were compared to the bulk macroscopic response. When cycling between these two phases, the evolution of inelastic strains, along with the shape setting procedures were examined and used for the optimization of the transformation properties as a function of deformation levels and temperatures. Finally, this work was extended to the development of multiaxial capabilities at elevated temperatures for the in situ neutron diffraction measurements of shape memory alloys on the VULCAN Diffractometer at Oak Ridge National Laboratory.

Texture, deformation twinning and hardening in a newly developed Mg-Dy-Al-Zn-Zr alloy processed with high pressure torsion

Czech Academy of Sciences Publication Activity Database

Kocich, R.; Kunčická, L.; Král, Petr; Lowe, T. C.

2016-01-01

Roč. 90, JAN (2016), s. 1092-1099 ISSN 0264-1275 Institutional support: RVO:68081723 Keywords : Magnesium * High pressure torsion * Texture * Deformation twinning * Hardening Subject RIV: JG - Metallurgy Impact factor: 4.364, year: 2016

Deformation-induced crystallographic-preferred orientation of hcp-iron: An experimental study using a deformation-DIA apparatus

Science.gov (United States)

Nishihara, Yu; Ohuchi, Tomohiro; Kawazoe, Takaaki; Seto, Yusuke; Maruyama, Genta; Higo, Yuji; Funakoshi, Ken-ichi; Tange, Yoshinori; Irifune, Tetsuo

2018-05-01

Shear and uniaxial deformation experiments on hexagonal close-packed iron (hcp-Fe) was conducted using a deformation-DIA apparatus at a pressure of 13-17 GPa and a temperature of 723 K to determine its deformation-induced crystallographic-preferred orientation (CPO). Development of the CPO in the deforming sample is determined in-situ based on two-dimensional X-ray diffraction using monochromatic synchrotron X-rays. In the shear deformation geometry, the and axes gradually align to be sub-parallel to the shear plane normal and shear direction, respectively, from the initial random texture. In the uniaxial compression and tensile geometry, the and axes, respectively, gradually align along the direction of the uniaxial deformation axis. These results suggest that basal slip (0001) is the dominant slip system in hcp-Fe under the studied deformation conditions. The P-wave anisotropy for a shear deformed sample was calculated using elastic constants at the inner core condition by recent ab-initio calculations. Strength of the calculated anisotropy was comparable to or higher than axisymmetric anisotropy in Earth's inner core.

On chiral-odd Generalized Parton Distributions

Energy Technology Data Exchange (ETDEWEB)

Wallon, Samuel [Laboratoire de Physique Theorique d' Orsay - LPT, Bat. 210, Univ. Paris-Sud 11, 91405 Orsay Cedex (France); UPMC Univ. Paris 6, Paris (France); Pire, Bernard [Centre de Physique Theorique - CPHT, UMR 7644, Ecole Polytechnique, Bat. 6, RDC, F91128 Palaiseau Cedex (France); Szymanowski, Lech [Soltan Institute for Nuclear Studies, Hoza 69, 00691, Warsaw (Poland)

2010-07-01

The chiral-odd transversity generalized parton distributions of the nucleon can be accessed experimentally through the exclusive photoproduction process {gamma} + N {yields} {pi} + {rho} + N', in the kinematics where the meson pair has a large invariant mass and the final nucleon has a small transverse momentum, provided the vector meson is produced in a transversally polarized state. Estimated counting rates show that the experiment is feasible with real or quasi real photon beams expected at JLab at 12 GeV and in the COMPASS experiment. (Phys Letters B688,154,2010) In addition, a consistent classification of the chiral-odd pion GPDs beyond the leading twist 2 is presented. Based on QCD equations of motion and on the invariance under rotation on the light-cone of any scattering amplitude involving such GPDs, we reduce the basis of these chiral-odd GPDs to a minimal set. (author)

A novel methodology for 3D deformable dosimetry.

Science.gov (United States)

Yeo, U J; Taylor, M L; Dunn, L; Kron, T; Smith, R L; Franich, R D

2012-04-01

Interfraction and intrafraction variation in anatomic structures is a significant challenge in contemporary radiotherapy. The objective of this work is to develop a novel tool for deformable structure dosimetry, using a tissue-equivalent deformable gel dosimeter that can reproducibly simulate targets subject to deformation. This will enable direct measurement of integrated doses delivered in different deformation states, and the verification of dose deforming algorithms. A modified version of the nPAG polymer gel has been used as a deformable 3D dosimeter and phantom to investigate doses delivered to deforming tissue-equivalent geometry. The deformable gel (DEFGEL) dosimeter/phantom is comprised of polymer gel in a latex membrane, moulded (in this case) into a cylindrical geometry, and deformed with an acrylic compressor. Fifteen aluminium fiducial markers (FM) were implanted into DEFGEL phantoms and the reproducibility of deformation was determined via multiple computed tomography (CT) scans in deformed and nondeformed states before and after multiple (up to 150) deformations. Dose was delivered to the DEFGEL phantom in three arrangements: (i) without deformation, (ii) with deformation, and (iii) cumulative exposures with and without deformation, i.e., dose integration. Irradiations included both square field and a stereotactic multiple dynamic arc treatment adapted from a patient plan. Doses delivered to the DEFGEL phantom were read out using cone beam optical CT. Reproducibility was verified by observation of interscan shifts of FM locations (as determined via CT), measured from an absolute reference point and in terms of inter-FM distance. The majority (76%) of points exhibited zero shift, with others shifting by one pixel size consistent with setup error as confirmed with a control sample. Comparison of dose profiles and 2D isodose distributions from the three arrangements illustrated complex spatial redistribution of dose in all three dimensions occurring as

A novel methodology for 3D deformable dosimetry

International Nuclear Information System (INIS)

Yeo, U. J.; Taylor, M. L.; Dunn, L.; Kron, T.; Smith, R. L.; Franich, R. D.

2012-01-01

Purpose: Interfraction and intrafraction variation in anatomic structures is a significant challenge in contemporary radiotherapy. The objective of this work is to develop a novel tool for deformable structure dosimetry, using a tissue-equivalent deformable gel dosimeter that can reproducibly simulate targets subject to deformation. This will enable direct measurement of integrated doses delivered in different deformation states, and the verification of dose deforming algorithms. Methods: A modified version of the nPAG polymer gel has been used as a deformable 3D dosimeter and phantom to investigate doses delivered to deforming tissue-equivalent geometry. The deformable gel (DEFGEL) dosimeter/phantom is comprised of polymer gel in a latex membrane, moulded (in this case) into a cylindrical geometry, and deformed with an acrylic compressor. Fifteen aluminium fiducial markers (FM) were implanted into DEFGEL phantoms and the reproducibility of deformation was determined via multiple computed tomography (CT) scans in deformed and nondeformed states before and after multiple (up to 150) deformations. Dose was delivered to the DEFGEL phantom in three arrangements: (i) without deformation, (ii) with deformation, and (iii) cumulative exposures with and without deformation, i.e., dose integration. Irradiations included both square field and a stereotactic multiple dynamic arc treatment adapted from a patient plan. Doses delivered to the DEFGEL phantom were read out using cone beam optical CT. Results: Reproducibility was verified by observation of interscan shifts of FM locations (as determined via CT), measured from an absolute reference point and in terms of inter-FM distance. The majority (76%) of points exhibited zero shift, with others shifting by one pixel size consistent with setup error as confirmed with a control sample. Comparison of dose profiles and 2D isodose distributions from the three arrangements illustrated complex spatial redistribution of dose in all

Lifetime measurements of odd-parity high-excitation levels of Sn I by time-resolved laser spectroscopy

International Nuclear Information System (INIS)

Zhang, Wei; Feng, Yanyan; Xu, Jiaxin; Dai, Zhenwen; Palmeri, Patrick; Quinet, Pascal; Biemont, Emile

2010-01-01

Natural radiative lifetimes of 38 odd-parity highly excited levels in neutral tin in the energy range from 43 682.737 to 56 838.68 cm -1 have been measured by a time-resolved laser-induced fluorescence technique in an atomic beam produced by laser ablation on a solid tin sample. All the levels were excited from the metastable 3 P 1, 2 and 1 D 2 levels in the ground configuration. The second and third harmonics of a dye laser were adopted as the tunable exciting source (207-250 nm). The lifetime results obtained in this paper are in the range from 4.6 to 292 ns and will be useful in extending the set of oscillator strengths available in Sn I.

Searches for possible T-odd and P-odd short range interactions using polarized nuclei

Directory of Open Access Journals (Sweden)

Chu P. H.

2014-03-01

Full Text Available Various theories predict the possible existence of T-odd and P-odd shortrange forces between spin ½ fermions, proportional to S・r where S is the fermion spin and r is the separation between particles. We use ensembles of polarized nuclei and an un-polarized mass to search for such a force over sub-mm ranges. We established an improved upper bound on the product gsgpn of the scalar coupling to particles in the un-polarized mass and the pseudo-scalar coupling of polarized neutrons for force ranges from 10−4 to 10−2 m, corresponding to a mass range of 2・10−3 to 2・10−5 eV for the exchange boson [1].

Internal deformation in layered Zechstein-III K-Mg salts. Structures formed by complex deformation and high contrasts in viscosity observed in drill cores.

Science.gov (United States)

Raith, Alexander; Urai, Janos L.

2016-04-01

During the evaporation of a massive salt body, alternations of interrupted and full evaporation sequences can form a complex layering of different lithologies. Viscosity contrasts of up to five orders of magnitude between these different lithologies are possible in this environment. During the late stage of an evaporation cycle potassium and magnesium (K-Mg) salts are precipitated. These K-Mg salts are of economic interest but also a known drilling hazard due to their very low viscosity. How up to 200m thick layers of these evaporites affect salt deformation at different scales is not well known. A better understanding of salt tectonics with extreme mechanical stratification is needed for better exploration and production of potassium-magnesium salts and to predict the internal structure of potential nuclear waste repositories in salt. To gain a better understanding of the internal deformation of these layers we analyzed K-Mg salt rich drill cores out of the Zechstein III-1b subunit from the Veendam Pillow 10 km southeast of Groningen, near the city Veendam in the NE Netherlands. The study area has a complex geological history with multiple tectonic phases of extension and compression forming internal deformation in the pillow but also conserving most of the original layering. Beside halite the most common minerals in the ZIII-1b are carnallite, kieserite, anhydrite and bischofite alternating in thin layers of simple composition. Seismic interpretation revealed that the internal structure of the Veendam Pillow shows areas, in which the K-Mg salt rich ZIII 1b layer is much thicker than elsewhere, as a result of salt deformation. The internal structure of the ZIII-1b on the other hand, remains unknown. The core analysis shows a strong strain concentration in the weaker Bischofite (MgCl2*6H20) and Carnallite (KMgCl3*6H20) rich layers producing tectonic breccias and highly strained layers completely overprinting the original layering. Layers formed by alternating beds

Plastic Deformation as a Means to Achieve Stretchable Polymer Semiconductors

Science.gov (United States)

O'Connor, Brendan

Developing intrinsically stretchable semiconductors will seamlessly transition traditional devices into a stretchable platform. Polymer semiconductors are inherently soft materials due to the weak van der Waal intermolecular bonding allowing for flexible devices. However, these materials are not typically stretchable and when large strains are applied they either crack or plastically deform. Here, we study the use of repeated plastic deformation as a means of achieving stretchable films. In this talk, critical aspects of polymer semiconductor material selection, morphology and interface properties will be discussed that enable this approach of achieving stretchable films. We show that one can employ high performance donor-acceptor polymer semiconductors that are typically brittle through proper polymer blending to significantly increase ductility to achieve stretchable films. We demonstrate a polymer blend film that can be repeatedly deformed over 65%, while maintaining charge mobility consistently above 0.15 cm2/Vs. During the stretching process we show that the films follow a well-controlled repeated deformation pattern for over 100 stretching cycles.