Decay Properties Of The Dipole Isobaric Analog Resonances
Gorelik, M L; Urin, M H
2006-01-01
A continuum-RPA-based approach is applied to describe the decay properties of isolated dipole isobaric analog resonances in nuclei having not-too-large neutron excess. Calculated for a few resonances in 90Zr the elastic E1-radiative width and partial proton widths for decay into one-hole states of 89Y are compared with available experimental data.
Study of $^{13}$Be through isobaric analog resonances in the Maya active target
Riisager, K; Orr, N A; Jonson, B N G; Raabe, R; Fynbo, H O U; Nilsson, T
We propose to perform an experiment with a $^{12}$Be beam and the Maya active target. We intend to study the ground state of $^{13}$Be through the population of its isobaric analog resonance in $^{13}$B. The resonance will be identified detecting its proton- and neutron-decay channels.
We present a new approach for the measurement of resonance excitation functions of neutron-rich nuclei using Doppler shift information. Preliminary data from the first application of the method is presented in the spectroscopy studies of 7He isobaric analog states in 7Li. (orig.)
A Küçükbursa; D I Salamov; T Babacan; H A Aygör
2004-11-01
Within the quasi-particle random phase approximation (QRPA), the method of the self-consistent determination of the isovector effective interaction which restores a broken isotopic symmetry for the nuclear part of the Hamiltonian is given. The effect of the pairing correlations between nucleons on the following quantities were investigated for the = 208 nuclei: energies of the isobar analog 0+ states, the isospin admixtures in the ground state of the even–even nuclei, and the differential cross-section for the 208Pb(3He,)208Bi reaction at E(3He) = 450 MeV. Both couplings of the excitation branches with z = 0 ± 1, and the analog state with isovector monopole resonance (IVMR) in the quasi-particle representation were taken into account in our calculations. As a result of these calculations, it was seen that the pairing correlations between nucleons have no considerable effect on the = 23 isospin admixture in the ground state of the 208Pb nucleus, and they cause partially an increase in the isospin impurity of the isobar analog resonance (IAR). It was also established that these correlations have changed the isospin structure of the IAR states, and shifted the energies of the IVMR states to the higher values.
Excitation functions have been measured for elastic scattering of polarized protons from 206Pb and 208Pb, and for inelastic scattering to collective states in 206Pb (2+, 0.8033 MeV; 3-, 2.647 MeV) and 208Pb (3-, 2.6145 MeV). Both differential cross sections and analyzing powers were measured at theta/sub lab/ = 1200, 1350, 1500, and 1650, for E/sub p/ = 14.25 to 18 MeV. Fits to the excitation-function data were obtained using scattering amplitudes consisting of sums of resonant and non-resonant parts. The resonances are the isobaric analogs (IARs) of 7 low-lying states in 209Pb and 35 in 207Pb. The fits to the elastic-scattering data are excellent; for the inelastic scattering the fit is very good for the 2+ state but only fair for the 3- states. For each IAR, the energy, the total width, and the partial width and mixing phase in each channel were obtained. Also, new spin assignments were made for a number of parent states in 207Pb. The theory of Bund and Blair was used to find the spectroscopic amplitudes, which provide information on the wave functions for the parent states in 207Pb and 209Pb and for the 3- states in 206Pb and 208Pb. These spectroscopic amplitudes were then checked for internal consistency and compared with the results of other experiments and with theoretical predictions
Survey of Evaluated Isobaric Analog States
MacCormick, M., E-mail: maccorm@ipno.in2p3.fr [Institut de Physique Nucléaire, CNRS/IN2P3, Université Paris-Sud, 91406 Orsay CEDEX (France); Audi, G. [Centre de Spectrométrie Nucléaire et de Spectrométrie de Masse, CNRS/IN2P3, Université Paris-Sud, Bât. 108, F-91405 Orsay Campus (France)
2014-06-15
Isobaric analog states (IAS) can be used to estimate the masses of members belonging to the same isospin multiplet. Experimental and estimated IAS have been used frequently within the Atomic Mass Evaluation (AME) in the past, but the associated set of evaluated masses have been published for the first time in AME2012 and NUBASE2012. In this paper the current trends of the isobaric multiplet mass equation (IMME) coefficients are shown. The T = 2 multiplet is used as a detailed illustration.
Widths of the isobaric analog state of 208Pb
Both escape and spreading widths are evaluated microscopically in a consistent framework for the isobaric analog of the 206Pb ground state. A TDA Green function is obtained within the space of discretized J=0+ proton-particle neutron-hole configurations using the Skyrme interaction. Couplings of these configurations with continuum and more complicated configurations are included into TDA matrix elements with a form of energy dependent terms. The energy and the widths of the isobaric analog resonance are obtained as a result of the matrix diagonalization. Comparison is made of the results with the former theoretical calculations as well as experimental data. (orig.)
D I Salmov; T Babacan; A Kücükbursa; S Ünlü; İ Maraṣ
2006-06-01
Within the framework of quasiparticle random phase approximation (QRPA), Pyatov–Salamov method [23] for the self-consistent determination of the isovector effective interaction strength parameter, restoring a broken isotopic symmetry for the nuclear part of the Hamiltonian, is used. The isospin admixtures in the ground state of the parent nucleus, and the isospin structure of the isobar analog resonance (IAR) state were investigated with the inclusion of the pairing correlations between nucleons for the medium and heavy mass regions: 80 < < 90, 102 < < 124, and 204 < < 214. It was determined that the influence of the pairing interaction between nucleons on the isospin admixtures in the ground state and the isospin structure of the IAR state is more pronounced for the light isotopes ( ≈ ) of the investigated nuclei.
Anomalous isobaric analogue resonance in 71As
In 1971 G. M. Temmer et al., reported observing five anomalous substructures in a spin 1/2+ isobaric analogue resonance in 71As at E/sub p/ = 5.05 MeV. They suggested that these substructures could be interpreted as ''hallway states'' coupling a ''doorway state'' to compound nuclear states. Although doorway states are well established interpretations of isobaric analogue resonances, hallway states have no such acreditation. The case investigated in this paper was the first reported evidence suggesting the existence of hallway states in an isobaric analogue resonance. In this work the validity of the hallway state interpretation was ascertained for two of the five substructures. The spin and parity of these two substructures were determined to be 5/2+; therefore, their interpretation as hallway states is incorrect since it would not conserve angular momentum. The spins and parities of all the substructures were determined by measuring the analyzing power of the elastic reaction 70Ge(p(pol),p0) from an energy E/sub p/ = 4.92 MeV to an energy E/sub p/ = 5.23 MeV in 10 keV steps. The analyzing power was then remeasured over the last two substructures at E = 5.05 MeV and E = 5.14 MeV in 5 keV steps. These last two substructures also decayed strongly to the 2+ first excited state in 70Ge. The angular correlation between the first inelastic proton and the subsequently emitted gamma ray was measured in the Goldfarb--Seyler geometry and was then expanded in terms of cosine functions. The expansion coefficients implied that the spins of these two resonances were greater than or equal to 5/2, in agreement with the analyzing power measurements
Symmetry Energy from Systematic of Isobaric Analog States
Danielewicz, Pawel
2011-01-01
Excitation energies to isobaric states, that are analogs of ground states, are dominated by contributions from the symmetry energy. This opens up a possibility of investigating the symmetry energy on nucleus-by-nucleus basis. Upon correcting energies of measured nuclear levels for shell and pairing effects, we find that the lowest energies for a given isospin rise in proportion to the square of isospin, allowing for an interpretation of the coefficient of proportionality in terms of a symmetry coefficient for a given nucleus. In the (A,Z) regions where there are enough data, we demonstrate a Z-independence of that coefficient. We further concentrate on the A-dependence of the coefficient, in order to learn about the density dependence of symmetry energy in uniform matter, given the changes of the density in the surface region. In parallel to the analysis of data, we carry out an analysis of the coefficient for nuclei calculated within the Skyrme-Hartree-Fock (SHF) approach, with known symmetry energy for unif...
Possible enhancement of magnetic dipole transitions between Gamow-Teller and isobaric analog states
A new decay scheme between Gamow-Teller (GT) resonances and isobaric analog states (IAS) by magnetic dipole transitions is studied. The sum rule of M1 transitions between IAS and GT states is found to be significantly enhanced compared to the non-energy-weighted sum rule of the parent state. Calculated enhancement factors can be as large as ∼2.5 for 48Sc and 90Nb, and 1.5 for 208Bi. Transition strengths between specific states are calculated in the Tamm-Dancoff approximation. The interest of measuring M1 transitions between IAS and GT states to obtain information on the spin-isospin response in finite nuclei is stressed. copyright 1995 The American Physical Society
Population and particle decay of isobaric analog states in medium heavy nuclei
The systematic features of proton stripping and neutron pickup reactions to Isobaric Analog States in medium heavy nuclei are presented. The (3He, d) reaction investigated at high incident energy is shown to selectively excite high-spin particle-analog states. Similarly the (3He, α) reaction populates hole-analog states. The recent results related to such highly excited states in a wide range of nuclei (48Ca to 208Pb) are discussed in the framework of the DWBA theory of direct reactions with special emphasis on the treatment of unbound proton states or deeply-bound neutron hole states. The particle decay of Isobaric Analog States are investigated using the (3He, d p tilde) and (3He, α p tilde) sequential processes. The experimental method developed at Orsay (00 detection) for particle-particle angular correlations is presented. The advantage and the limits of such approach are illustrated by typical exemples of particle decays: core-excited states, neutron particle-hole multiplets and the first observation of the proton emission of hole-analog levels. In conclusion new experimental approaches such as asymmetry measurements for analog states observed in transfer reactions or possible population of double analog states in heavy nuclei are discussed. (author)
Halo Structure of the Isobaric Analog States in Some Mirror Nuclei
2001-01-01
Using ANC method the rms radius of the last nucleon in the 2s1/2 isobaric analog states of 21Ne/2lNa and 17O / 17F is extracted from transfer reaction data. The results are summarized in Tab. 1. The 2s1/2 single proton states in 21Na and 17O have the rms radii almost twice as large as that for their core nuclei (2.88 fin for 20Ne and 2.71 fm for 16O) and are proton halo states, while their isobaric analog states in 2INe and I7O can be considered as neutron skin states, because the neutrons in these states have one third of the probability staying out of the nuclear interaction range. The obvious difference in the rms radii between a mirror pair indicates the binding energy difference between the
Effects of CIB (charge independence breaking) and CSB (charge symmetry breaking) interactions on the Coulomb displacement energies of isobaric analog states are investigated for 48Ca, 90Zr and 208Pb. Mass number dependence of the Coulomb energy anomalies is well explained when CIB and CSB interactions are used which reproduce the differences of the scattering lengths as well as those of the effective ranges of low energy nucleon-nucleon scattering. (author) 17 refs., 3 figs., 3 tabs
Korpa, C. L.; Lutz, M. F. M.
2003-01-01
We evaluate the in-medium spectral functions for pions, nucleon and isobar resonances in a self consistent and covariant manner. The calculations are based on a recently developed formulation which leads to predictions in terms of the pion-nucleon scattering phase shifts and a set of Migdal parameters describing important short range correlation effects. We do not observe significant softening of pion modes if we insist on reasonable isobar resonance properties but predict a considerable broa...
Wang, Zaijun; Xu, Renli
2016-01-01
The Coulomb displacement energies of the neutron-rich Ar-K isobaric analog state pairs with mass number $A=35-47$ are calculated within the relativistic mean field model and the effects of level inversion on the Coulomb displacement energies of the Ar-K isobaric analog state pairs are studied. The calculations are carried out in two cases, with and without consideration of the possible $2s_{1/2}$ and $1d_{3/2}$ proton level inversion of the neutron-rich Ar isotopes. Results show that the $2s_{1/2}$ and $1d_{3/2}$ level inversion of the neutron-rich Ar isotopes may reduce the Coulomb displacement energy by 0.06$\\sim$0.17 MeV for the Ar-K isobaric analog state pairs. The results may provide a reference for experimental investigations of nuclear level inversion and a new test of the relativistic mean field model.
We evaluate the in-medium spectral functions for pions, nucleon and isobar resonances in a self consistent and covariant manner. The calculations are based on a recently developed formulation which leads to predictions in terms of the pion-nucleon scattering phase shifts and a set of Migdal parameters describing important short range correlation effects. We do not observe any significant softening of pion modes if we insist on reasonable isobar resonance properties but predict a considerable broadening of the N(1440) and N(1520) resonances in nuclear matter. (orig.)
Classical analogy of Fano resonances
We present an analogy of Fano resonances in quantum interference to classical resonances in the harmonic oscillator system. It has a manifestation as a coupled behaviour of two effective oscillators associated with propagating and evanescent waves. We illustrate this point by considering a classical system of two coupled oscillators and interfering electron waves in a quasi-one-dimensional narrow constriction with a quantum dot. Our approach provides a novel insight into Fano resonance physics and provides a helpful view in teaching Fano resonances
A study of Gamow-Teller mixing: Coupling to delta (1232) and isobaric analogue resonances
Lambert, M.H.
1988-01-01
The problem of missing Gamow-Teller strength is examined in two calculations. The mixing between nucleonic Gamow-Teller states and those containing a delta(1232) resonance in calcium-48, zirconium-90 and tin-132 is studied as a function of the excitation energy of a delta in the nucleus in a shell-model calculation. It is found that mixing is large enough at the experimentally observed nucleon-delta separation to warrant treating the nucleon and the delta resonance on similar footing in intermediate energy nuclear physics. In a second calculation, the coupled channels impulse approximation is used to examine the effect on the Gamow-Teller cross section of coupling to the isobaric analogue state. This is done for incident proton energies of 140 and 175 MeV on a calcium-48 target. Effects on the cross-section of the separation between the isobaric analogue and Gamow-Teller states are also studied. It is found that coupling to the isobaric analogue state has little effect on either the Gamow-Teller or the isobaric analogue cross section.
Isobaric analogue resonances in the 56Fe(rho,γ)57Co reaction
The excitation function for the reaction 56Fe(rho,γ)57Co has been measured from 1200-3000 KeV proton energy using enriched 56Fe targets. The resonance strength, ωsub(γ), has been determined for the studied resonances. The absence of the isobaric analogue resonance corresponding to the ground state in 57Fe is discussed as a result of the present study. A coulomb displacement energy for 57Co-57Fe of 8876 +- 6 KeV is deduced from these measurements. (author)
Structure of isobaric analog states in 91Nb populated by the 90Zr(a,t) reaction
Van der Molen, H K T; Van den Berg, A M; Daito, I; Fujimura, H; Fujita, Y; Fujiwara, M; Harakeh, M N; Ihara, F; Inomato, T; Ishibashi, K; Jänecke, J; Kalantar-Nayestanaki, N; Laurent, H; Lhenry, I; O'Donnell, T W; Rodin, V A; Tamii, A; Toyokawa, H; Urin, M H; Yoshida, H; Yosoi, M
2001-01-01
Decay via proton emission of isobaric analog states (IAS's) in $^{91}{Nb}$ was studied using the $^{90}{Zr}(\\alpha,t)$ reaction at $E_\\alpha$=180 MeV. This study provides information about the damping mechanism of these states. Decay to the ground state and low-lying phonon states in $^{90}{Zr}$ was observed. The experimental data are compared with theoretical predictions wherein the IAS `single-particle' proton escape widths are calculated in a continuum RPA approach. The branching ratios for decay to the phonon states are explained using a simple model.
With the resent improvements in the field of exotics beams, and specially with the SPIRAL facility at GANIL, we were able to study He9 shell inversion already known for Be11 and Li10, which are two members of the N=7 family. A new detector was developed and also the software tools for the data analysis. This detector is at the same time the target (active-target) and is called MAYA. The He9 was studied by determining the properties of its isobaric analogue states in Li9. The characteristics of the IAS (isomeric analog state) states were determined by an analysis of the resonances in the elastic scattering cross section for He8 + p from 2 up to 3.9 MeV/n. A study of (p,d) and (p,t) reactions was done too, in this domain of energy. By comparing the experimental results with calculations, an assignation of spin and parity for two states in He9 was possible. (author)
Khoa, Dao T; Cuong, Do Cong
2007-01-01
A consistent folding model analysis of the ($\\Delta S=0, \\Delta T=1$) charge exchange \\pn reaction measured with $^{48}$Ca, $^{90}$Zr, $^{120}$Sn and $^{208}$Pb targets at the proton energies of 35 and 45 MeV is done within a two-channel coupling formalism. The nuclear ground state densities given by the Hartree-Fock-Bogoljubov formalism and the density dependent CDM3Y6 interaction were used as inputs for the folding calculation of the nucleon optical potential and \\pn form factor. To have an accurate isospin dependence of the interaction, a complex isovector density dependence of the CDM3Y6 interaction has been carefully calibrated against the microscopic Brueckner-Hatree-Fock calculation by Jeukenne, Lejeune and Mahaux before being used as folding input. Since the isovector coupling was used to explicitly link the isovector part of the nucleon optical potential to the cross section of \\pn reaction exciting the 0$^+$ isobaric analog states in $^{48}$Sc, $^{90}$Nb, $^{120}$Sb and $^{208}$Bi, the newly paramet...
The Lamda-N - Sigma-N Interaction with Isobar Coupling and Six-Quark Resonances
Greenberg, W. R.; Lomon, E. L.
1992-01-01
The long-range $\\Lambda N-\\Sigma N$ interaction is modeled by a configuration space meson-exchange potential matrix coupling to channels with $\\Delta$ and $\\Sigma(1385)$ isobars. An inner boundary condition, based on $R$-matrix theory, replaces form factors for short-range effects and includes the effects of free quark configurations. An excellent fit is obtained to the available data, with only the energy-independent boundary conditions as free parameters. The effect of isobar thresholds is ...
E. Uberseder
2016-03-01
Full Text Available The level structure of the very neutron rich and unbound 9He nucleus has been the subject of significant experimental and theoretical study. Many recent works have claimed that the two lowest energy 9He states exist with spins Jπ=1/2+ and Jπ=1/2− and widths on the order of 100–200 keV. These findings cannot be reconciled with our contemporary understanding of nuclear structure. The present work is the first high-resolution study with low statistical uncertainty of the relevant excitation energy range in the 8He+n system, performed via a search for the T=5/2 isobaric analog states in 9Li populated through 8He+p elastic scattering. The present data show no indication of any narrow structures. Instead, we find evidence for a broad Jπ=1/2+ state in 9He located approximately 3 MeV above the neutron decay threshold.
Uberseder, E; Goldberg, V Z; Koshchiy, E; Roeder, B T; Alcorta, M; Chubarian, G; Davids, B; Fu, C; Hooker, J; Jayatissa, H; Melconian, D; Tribble, R E
2015-01-01
The level structure of the very neutron rich and unbound $^9$He nucleus has been the subject of significant experimental and theoretical study. Many recent works have claimed that the two lowest energy $^9$He states exist with spins $J^\\pi=1/2^+$ and $J^\\pi=1/2^-$ and widths on the order of hundreds of keV. These findings cannot be reconciled with our contemporary understanding of nuclear structure. The present work is the first high-resolution study with low statistical uncertainty of the relevant excitation energy range in the $^8$He$+n$ system, performed via a search for the T=5/2 isobaric analog states in $^9$Li populated through $^8$He+p elastic scattering. The present data show no indication of any narrow structures. Instead, we find evidence for a broad $J^{\\pi}=1/2^+$ state in $^9$He located approximately 3 MeV above the neutron decay threshold.
Khoa, Dao T.; Thang, Dang Ngoc [VINATOM, Institute for Nuclear Science and Technique, Hanoi (Viet Nam); Loc, Bui Minh [VINATOM, Institute for Nuclear Science and Technique, Hanoi (Viet Nam); University of Pedagogy, Ho Chi Minh City (Viet Nam)
2014-02-15
The Fermi transition (ΔL = ΔS = 0 and ΔT = 1) between the nuclear isobaric analog states (IAS), induced by the charge-exchange (p, n) or ({sup 3}He, t) reaction, can be considered as ''elastic'' scattering of proton or {sup 3}He by the isovector term of the optical potential (OP) that flips the projectile isospin. The accurately measured (p, n) or ({sup 3}He, t) scattering cross section to the IAS can be used, therefore, to probe the isospin dependence of the proton or {sup 3}He optical potential. Within the folding model, the isovector part of the OP is determined exclusively by the neutron-proton difference in the nuclear densities and the isospin dependence of the effective nucleon-nucleon (NN) interaction. Because the isovector coupling explicitly links the isovector part of the proton or {sup 3}He optical potential to the cross section of the charge-exchange (p, n) or ({sup 3}He, t) scattering to the IAS, the isospin dependence of the effective (in-medium) NN interaction can be well tested in the folding model analysis of these charge-exchange reactions. On the other hand, the same isospin- and density-dependent NN interaction can also be used in a Hartree-Fock calculation of asymmetric nuclear matter, to estimate the nuclear matter energy and its asymmetry part (the nuclear symmetry energy). As a result, the fine-tuning of the isospin dependence of the effective NN interaction against the measured (p, n) or ({sup 3}He, t) cross sections should allow us to make some realistic prediction of the nuclear symmetry energy and its density dependence. (orig.)
Analog implementation of an integral resonant control scheme
Integral resonant control (IRC) has been introduced as a high performance controller design methodology for flexible structures with collocated actuator–sensor pairs. IRC has a simple structure and is capable of achieving significant damping, over several modes, while guaranteeing closed-loop stability of the system in the presence of unmodeled out-of-bandwidth dynamics. IRC can be an ideal controller for various industrial damping applications, if packaged in a simple easy-to-implement electronic module. This work proposes an analog implementation of the IRC scheme using a single Op-Amp circuit. The objective is to show that with simple analog realization of the modified IRC scheme, it is possible to damp a large number of vibration modes. A brief discussion about the modeling, circuit considerations, implementation and experimental results is presented in order to validate the usefulness and practicality of the proposed analog IRC implementation. (technical note)
In the present study, the effect of the pairing interaction and the isovector correlation between nucleons on the properties of the isobar analogue resonances (IAR) in 112-124Sb isotopes and the isospin admixture in 100-124Sn isotopes is investigated within the framework of the proton-neutron quasi-particle random phase approximation (pnQRPA). The form of the interaction strength parameter is related to the shell-model potential by restoring the isotopic invariance of the nuclear part of the total Hamiltonian. In this respect, the isospin admixtures in the 100-124Sn isotopes are calculated, and the dependence of the differential cross section and the volume integral JF for the Sn(3He,t)Sb reactions at E(3He) =200 MeV occurring by the excitation of IAR on mass number A is examined. Our results show that the calculated value for the isospin mixing in the 100Sn isotope is in good agreement with Colo et al's estimates (4-5%), and the obtained values for the volume integral change within the error range of the value reported by Fujiwara et al (53 ± 5 MeV fm3). Moreover, it is concluded that although the differential cross section of the isobar analogue resonance for the (3He,t) reactions is not sensitive to pairing correlations between nucleons, a considerable effect on the isospin admixtures in N ∼ Z isotopes can be seen with the presence of these correlations
Level width of giant resonances and hole analog states
Widths of giant resonances and hole analog states are evaluated from the linear response function which is proportional to the imaginary part of Green's function. The Hartree Fock hamiltonian obtained by using the Skyrme interactions is diagonalized with harmonic oscillator basis. The resulting single particle states are all bound, and the continuum wave functions are constructed to be orthogonal to the bound states. Using these bases the energy matrix is calculated, where the self-energy is added to the particle or hole energy. The imaginary part of the self-energy consists of two parts, one corresponds to decay into more complicated states and other corresponds to decay into the continuum. The matrix is inverted and Green's function is obtained. The calculations are carried out for monopole states in 40Ca and hole analog states in 207Pb. The latter results are compared with the experimental data. (author)
Present status of isobar models for elementary kaon photoproduction
Some basic properties of isobar models are demonstrated and discussed on examples of the Saclay-Lyon and Kaon-MAID models. Predictions of these models are compared with experimental data for various processes and kinematical regions. Results of the isobar models are also compared with the Regge-isobar hybrid model, Regge-plus-resonance. (author)
Present status of isobar models for elementary kaon photoproduction
Bydzovsky, Petr; Skoupil, Dalibor
2012-01-01
Some basic properties of isobar models are demonstrated and discussed on examples of the Saclay-Lyon and Kaon-MAID models. Predictions of these models are compared with experimental data for various processes and kinematical regions. Results of the isobar models are also compared with the Regge-isobar hybrid model, Regge-plus-resonance.
Cao, L G; Colo', G; Sagawa, H
2015-01-01
We investigate the impact of the neutron-skin thickness Delta(R) on the energy difference between the anti-analog giant dipole resonance (AGDR), E(AGDR), and the isobaric analog state (IAS), E(IAS), in a heavy nucleus such as 208Pb. For guidance, we first develop a simple and analytic, yet physical, approach based on the Droplet Model that linearly connects the energy difference E(AGDR)-E(IAS) with Delta(R). To test this correlation on more fundamental grounds, we employ a family of systematically varied Skyrme energy density functionals where variations on the value of the symmetry energy at saturation density J are explored. The calculations have been performed within the fully self consistent Hartree-Fock (HF) plus charge-exchange random phase approximation (RPA) framework. We confirm the linear correlation within our microscopic apporach and, by comparing our results with available experimental data in 208Pb, we find that our analysis is consistent with Delta(R) = 0.204 \\pm 0.009 fm, J = 31.4 \\pm 0.5 MeV ...
Unitary Isobar Model - MAID2007
Drechsel, D.; Kamalov, S. S.; Tiator, L.
2007-01-01
The unitary isobar model MAID2007 has been developed to analyze the world data of pion photo- and electroproduction. The model contains both a common background and several resonance terms. The background is unitarized according to the K-matrix prescription, and the 13 four-star resonances with masses below 2 GeV are described by appropriately unitarized Breit-Wigner forms. The data have been analyzed by both single-energy and global fits, and the transverse and longitudinal helicity amplitud...
This paper covers the following aspects of isobar excitations in nuclei: Nuclear spin response; Electromagnetic probes; Pion-nuclear reactions; Baryon charge exchange reactions; Charge exchange reactions on nuclei; and Exclusive spectra
A test of the theory of resonant scattering between analog nuclei
It has been suggested that strong resonances might be found in scattering between analog nuclei at energies near the Coulomb barrier. The authors have begun a study of such scattering for 7Be on 7Li using a 7Be beam produced with the OSU-LLNL radioactive ion beam facility. The resulting excitation function can be used to limit a combination of the strength and the width of any possible resonances
Demonstration of a 3-bit optical digital-to-analog converter based on silicon microring resonators.
Yang, Lin; Ding, Jianfeng; Chen, Qiaoshan; Zhou, Ping; Zhang, Fanfan; Zhang, Lei
2014-10-01
We propose an N-bit optical digital-to-analog converter based on silicon microring resonators (MRRs), which can transform an N-bit electrical digital signal to an optical analog signal. A 3-bit optical digital-to-analog convertor is fabricated as proof of concept through a CMOS-compatible process on a silicon-on-insulator platform. The silicon MRRs are modulated through the electric-field-induced carrier injection in forward biased PN junctions embedded in the ring waveguides. The electro-optical 3-dB bandwidths of the silicon MRRs are approximately 800 MHz. The device works well at a speed of 500 MSample/s under driving voltage swings of 0.75 V. PMID:25360972
Babacan, Tahsin [Department of Physics, Celal Bayar University, Manisa (Turkey); Salamov, Djavad [Department of Physics, Anadolu University, Eskisehir (Turkey); Kuecuekbursa, Atalay [Department of Physics, Dumlupinar University, Kuetahya (Turkey); Babacan, Halil [Department of Physics, Celal Bayar University, Manisa (Turkey); Maras, Ismail [Department of Physics, Celal Bayar University, Manisa (Turkey); Aygoer, Hasan A [Department of Physics, Celal Bayar University, Manisa (Turkey); Uenal, Arslan [Department of Physics, Dumlupinar University, Kuetahya (Turkey)
2004-06-01
In the present study, the effect of the pairing interaction and the isovector correlation between nucleons on the properties of the isobar analogue resonances (IAR) in {sup 112-124}Sb isotopes and the isospin admixture in {sup 100-124}Sn isotopes is investigated within the framework of the proton-neutron quasi-particle random phase approximation (pnQRPA). The form of the interaction strength parameter is related to the shell-model potential by restoring the isotopic invariance of the nuclear part of the total Hamiltonian. In this respect, the isospin admixtures in the {sup 100-124}Sn isotopes are calculated, and the dependence of the differential cross section and the volume integral J{sub F} for the Sn({sup 3}He,t)Sb reactions at E({sup 3}He) =200 MeV occurring by the excitation of IAR on mass number A is examined. Our results show that the calculated value for the isospin mixing in the {sup 100}Sn isotope is in good agreement with Colo et al's estimates (4-5%), and the obtained values for the volume integral change within the error range of the value reported by Fujiwara et al (53 {+-} 5 MeV fm{sup 3}). Moreover, it is concluded that although the differential cross section of the isobar analogue resonance for the ({sup 3}He,t) reactions is not sensitive to pairing correlations between nucleons, a considerable effect on the isospin admixtures in N {approx} Z isotopes can be seen with the presence of these correlations.
Escape and spreading properties of charge-exchange resonances in 208Bi
The properties of charge-exchange excitations of 208Pb with ΔL = 0, i.e., the isobaric analog and Gamow-Teller resonances, are studied within a self-consistent model making use of an effective force of the Skyrme type. The well-known isobaric analog case is used to assess the reliability of the model. The calculated properties of the Gamow-Teller resonance are compared with recent experimental measurements with the aim of better understanding the microscopic structure of this mode. (authors). 30 refs., 5 figs., 6 tabs
An isobar-surfaces approach to multidimensional outlier-proneness.
Barme-Delcroix, Marie-Francoise; Gather, Ursula
2000-01-01
The aim of this paper is to define and investigate outlier-proneness for multivariate distributions. This is done by using a concept of ordering multivariate data based on isobar-surfaces, which yields an utmost analogy of the results to the univariate case.
Isobar Model for Photoproduction of K+Sigma0 and K0Sigma+ on the Proton
Mart, T.
2005-01-01
Kaon photoproductions on the proton gamma p --> K+Sigma0 and gamma p --> K0Sigma+ have been simultaneously analyzed by using isobar models and new SAPHIR data. The result shows that isobar models such as KAON MAID require more resonances in order to explain the data.
Optical Analog-to-digital Conversion Scheme Based on Tunable Fabry-Perot Resonator
LI Zheng
2007-01-01
Proposed is an interference type of optical analog-to-digital conversion(ADC). The refractive index of Fabry-Perot cavity changes with different voltages. The Fabry-Perot resonator converts electronic intensity into light wavelength through selecting lights of different wavelengthes. The parameters of the scheme are acquired with the transmission matrix of optical element and the time of steady-state light field. The maximum sampling speedes of 4-bit, 6-bit, 7-bit, 8-bit and 9-bit(ADC) are 1.695×1010 count/s, 4.33×109 count/s, 2.38×109 count/s, 1.24×109 count/s and 5.9×108 count/s, respectively.
Anti-analog giant dipole resonances and the neutron skin of nuclei
We examine a method to determine the neutron-skin thickness of nuclei using data on the charge-exchange anti-analog giant dipole resonance (AGDR). Calculations performed using the relativistic proton–neutron quasiparticle random-phase approximation (pn-RQRPA) reproduce the isotopic trend of the excitation energies of the AGDR, as well as that of the spin-flip giant dipole resonances (IVSGDR), in comparison to available data for the even–even isotopes 112–124Sn. It is shown that the excitation energies of the AGDR, obtained using a set of density-dependent effective interactions which span a range of the symmetry energy at saturation density, supplemented with the experimental values, provide a stringent constraint on value of the neutron-skin thickness. For 124Sn, in particular, we determine the value ΔRpn=0.21±0.05 fm. The result of the present study shows that a measurement of the excitation energy of the AGDR in (p,n) reactions using rare-isotope beams in inverse kinematics, provides a valuable method for the determination of neutron-skin thickness in exotic nuclei
Mesonic and isobar modes in matter
Experiments with heavy ion collisions, like the ones performed at the GSI, are a tool to gain insight in the structure of matter. One key point needed to understand the experimental data is the theoretical description of the in medium properties of mesons and baryons. In this thesis we first developed a self-consistent description for the light vector mesons, ρ and ω, and the pion at finite temperature and in a baryon free environment. A generalisation of these calculations towards finite densities mandatorily needs a reliable description for the pion and the Δ(1232) resonance. Here we extended the approaches discussed in literature by the inclusion of vertex corrections and a selfconsistent and completely relativistic description. Within these models we were able to show that even at high temperatures the ρ-meson properties are not changed dramatically when temperature effects are considered only. In contrast to this the behaviour of the pion and the Δ-isobar is dramatically changed a finite density. The isobar mass-shift is given by an appropriate choice of the mean-fields. Therefore we can not draw a final conclusion about such shifts within our model. In order to do so more calculations, especially of the photo absorption on the nucleus, have to be performed. A further aspect of the calculations presented is that due to a consistent consideration of vertex corrections we were able to achieve a description of the Δ-resonance without the usually used soft formfactor. This is especially important for the in-medium calculations because only in this way we can guarantee that soft modes of the spectrum are treated consistently. The techniques developed within this thesis allow for a straight forward generalisation of the presented models with respect to the consideration of more resonances or couplings. Doing so the here obtained description of the in-medium properties of the considered particles can be refined. (orig.)
Mesonic and isobar modes in matter
Riek, Felix C.
2007-07-01
Experiments with heavy ion collisions, like the ones performed at the GSI, are a tool to gain insight in the structure of matter. One key point needed to understand the experimental data is the theoretical description of the in medium properties of mesons and baryons. In this thesis we first developed a self-consistent description for the light vector mesons, {rho} and {omega}, and the pion at finite temperature and in a baryon free environment. A generalisation of these calculations towards finite densities mandatorily needs a reliable description for the pion and the {delta}(1232) resonance. Here we extended the approaches discussed in literature by the inclusion of vertex corrections and a selfconsistent and completely relativistic description. Within these models we were able to show that even at high temperatures the {rho}-meson properties are not changed dramatically when temperature effects are considered only. In contrast to this the behaviour of the pion and the {delta}-isobar is dramatically changed a finite density. The isobar mass-shift is given by an appropriate choice of the mean-fields. Therefore we can not draw a final conclusion about such shifts within our model. In order to do so more calculations, especially of the photo absorption on the nucleus, have to be performed. A further aspect of the calculations presented is that due to a consistent consideration of vertex corrections we were able to achieve a description of the {delta}-resonance without the usually used soft formfactor. This is especially important for the in-medium calculations because only in this way we can guarantee that soft modes of the spectrum are treated consistently. The techniques developed within this thesis allow for a straight forward generalisation of the presented models with respect to the consideration of more resonances or couplings. Doing so the here obtained description of the in-medium properties of the considered particles can be refined. (orig.)
Achasov, M. N.; Achasov, N. N.; Golubev, V. B.; Serednyakov, S. I.
1996-01-01
It is shown that when beams interact with a residual gas at $\\phi$-factories the reaction of the electroproduction of the $\\Delta (1232)$ isobar proceeds vigorously. The isobar decay gives $\\sim 10^7$ pions during an effective year of $10^7$ s per meter of a residual gas. These pions are emitted largely across the beam axis and have a resonance energy distribution with a peak nearby 265 MeV of a width close to 120 MeV in the isobar rest system. There are presented formulae for the distributio...
Neutron-skin thickness of 208Pb from the energy of the anti-analog giant dipole resonance
Krasznahorkay, A; Vretenar, D; Harakeh, M N
2013-01-01
The energy of the charge-exchange Anti-analog Giant Dipole Resonance (AGDR) has been calculated for the 208Pb isotope using the state-of-the-art fully self-consistent relativistic proton-neutron quasiparticle random-phase approximation based on the Relativistic Hartree-Bogoliubov model. It is shown that the AGDR centroid energy is very sensitively related to the corresponding neutron-skin thickness. The neutron-skin thickness of 208Pb has been determined very precisely by comparing the theoretical results with the available experimental data on E(AGDR). The result DR(pn)= 0.161(42) agrees nicely with the previous experimental results.
Minicomputer Mera-400 based analog signal data acquisition system is described. The peripherical controlers of the computer and the operating system SOM-3 are used. The analog signal is first digitized and stored in 1024 words of 8 bit buffer memory of the transient recorder and then transferred into the minicomputer memory for averaging. 1 k words of the computer memory can be shown on a CRT of a simple graphic display or registered on a X-Y recorder. A detail description of the hardware and of the software written in the assembler is also presented. (author)
Isobars and the efficient market hypothesis
Ivanková, Kristýna
2010-01-01
Isobar surfaces, a method for describing the overall shape of multidimensional data, are estimated by nonparametric regression and used to evaluate the efficiency of selected markets based on returns of their stock market indices.
An isobar model for eta photo- and electroproduction on the nucleon
Chiang, Wen-Tai; Yang, Shin Nan; Tiator, Lothar; Drechsel, Dieter
2001-01-01
Eta photo- and electroproduction on the nucleon is studied using an isobar model. The model contains Born terms, and contributions from vector meson exchanges and nucleon resonances. Our results are compared with recent eta photoproduction data for differential and total cross sections, beam asymmetry, and target asymmetry, as well as electroproduction data. Besides the dominant S11(1535) resonance, we show that the second S11 resonance, S11(1650), is also necessary to be included in order to...
Aznauryan, I. G.
2002-01-01
Two approaches for analysis of pion photo- and electroproduction on nucleons in the resonance energy region are checked at $Q^2=0$ using the results of GWU(VPI) partial-wave analysis of photoproduction data. The approaches are based on dispersion relations and unitary isobar model. Within dispersion relations good description of photoproduction multipoles is obtained up to $W=1.8 GeV$. Within unitary isobar model, modified with increasing energy by incorporation of Regge poles, and with unifi...
Application of isobars to stock market indices
Ivanková, Kristýna
České Budějovice : University of South Bohemia, 2010 - (Houda, M.; Friebelová, J.), s. 296-301 ISBN 978-80-7394-218-2. [Mathematical Methods in Economics. Ceske Budejovice (CZ), 08.09.2010-10.09.2010] R&D Projects: GA ČR GD402/09/H045 Institutional research plan: CEZ:AV0Z10750506 Keywords : isobars * efficient market hypothesis * nonparametric regression * extreme value theory Subject RIV: AH - Economics http://library.utia.cas.cz/separaty/2010/E/ivankova-application of isobars to stock market indices.pdf
Does it make any sense to talk about a Delta-isobar?
Kleefeld, F.
2002-01-01
It is shortly investigated, on what basis an experimentally observed resonance like the Delta(1232)-isobar can be embedded into the framework of Quantum Theory (QT), i.e. Quantum Field Theory (QFT) and Quantum Mechanics (QM). After a short discussion of the particle concept in the context of the "bootstrap" idea of G. Chew and S. Mandelstam we will focus on the theoretical formalism being necessary to describe resonances in the Lagrangian or Hamiltonian formulation of QT.
Does it make any sense to talk about a Delta-isobar?
Kleefeld, F
2003-01-01
It is shortly investigated, on what basis an experimentally observed resonance like the Delta(1232)-isobar can be embedded into the framework of Quantum Theory (QT), i.e. Quantum Field Theory (QFT) and Quantum Mechanics (QM). After a short discussion of the particle concept in the context of the "bootstrap" idea of G. Chew and S. Mandelstam we will focus on the theoretical formalism being necessary to describe resonances in the Lagrangian or Hamiltonian formulation of QT.
Finite size effects in isobaric ratios
Souza, S R
2011-01-01
The properties of isobaric ratios, between nuclei produced in the same reaction, are investigated using the canonical and grand-canonical statistical ensembles. Although the grand-canonical for- mulae furnish a means to correlate the ratios with the liquid drop parameters, finite size effects make it difficult to obtain their actual values from fitting nuclear collision data.
Isobaric-spin relationships between nuclear spectra
French, J.B.
1961-01-01
The simple fact that a one-body energy describes the interaction of a nucleon with a closed neutron subshell is used to establish sets of equations connecting the spectra of nuclei which are related by isobaric-spin when described by means of the nuclear shell model. Certain formal questions about i
Isobar separator for radioactive nuclear beams project
Davids, C.N.; Nolen, J.A.
1995-08-01
In order to produce pure beams of radioactive products emanating from the production target/ion source system, both mass and isobar separation is required. A preliminary mass separation with a resolution {triangle}M/M of approximately 10{sup -3} will select the proper mass beam. An isobar separator is needed because the masses of adjacent isobars are usually quite close, especially for beams near stability. In general, a mass resolution of 5 x 10{sup -5} is needed for isobar separation in the A < 120 region, while a resolution of 3 x 10{sup -5} or better is needed for heavier masses. Magnets are used to obtain mass separation. However, in addition to having mass dispersion properties, magnets also have an equal energy dispersion. This means that an energy variation in the beam cannot be distinguished from a mass difference. This is important because ions emerge from the ion source having a small ({approximately} 10{sup -5} - 10{sup -4}) energy spread. In order to make the system respond only to mass differences, it must be made energy dispersion. This is normally accomplished by using a combination of electric and magnetic fields. The most convenient way of doing this is to use an electric deflection following the magnet separator. A preliminary isobar separator which achieves a mass resolution of 2.7 x 10{sup -5} is shown in Figure I-38. It uses two large 60{degrees} bending magnets to obtain a mass dispersion of 140 mm/%, and four electric dipoles with bending angles of 39{degrees} to cancel the energy dispersion. Sextupole and octupole correction elements are used to reduce the geometrical aberrations.
Isobar width effects in the coupling of nucleon to isobar channels
González Marhuenda, Pedro; Lomon, Earle L.
1986-01-01
The investigation of the effects of isobar coupling to two-nucleon channels has been extended to include additional physical features. A new code discretizes the mass distribution of the isobar widths and treats each mass as a separate channel. This allows the treatment of width in the presence of coupling by transition potentials, in addition to the previously permitted boundary coupling. It also produces the S-matrix components required to describe the many-body final-state distributions. W...
Momentum distribution of Delta- isobar in closed shell nuclei
Tabachenko, A. N.
2005-01-01
One Delta- isobar components of the wave function in closed shell nuclei are considered within the framework of the harmonic oscillator model. Conventional transition potential is the pi- and rho- exchange potential. On the basis of the Delta- isobar configuration wave function, the momentum distribution of the Delta- isobar is calculated for the light nuclei $^4 He$,$^{16}O$,$^{12}C$
Revalidation of the isobaric multiplet mass equation at A=53, T=3/2
J. Su
2016-05-01
Full Text Available The T=3/2 isobaric analog state (IAS in 53Co is firmly established through a comprehensive measurement of β-delayed γ and proton decay of 53Ni. The determined excitation energy of 53Co IAS combined with the mass of 53Co generates a precise mass excess of −38333.6(27 keV for the 53Co IAS, which is 70(18 keV lower than the previously adopted value. The new result solves a problem raised by incorrect assignments of the 53Co IAS of unexpected deviation from the isobaric multiplet mass equation (IMME at A=53, T=3/2.
Gamow-Teller Transition Strength - Isospin Symmetry In A = 26 Isobars
Under the assumption that isospin is a good quantum number, isospin symmetry is expected for the Tz = ±1 → 0 isobaric analogous transitions in A = 26 isobar triplet, where Tz is the z component of isospin T and is defined by Tz = (N - Z) / 2. The isospin symmetric Tz = -1 → 0 Gamow-Teller (GT) transitions can be determined in the 26Si β decay. Assuming this symmetry it is possible to study the GT transition strengths for high excited states in 26Al induced by the (3He, t) charge-exchange (CE) reaction at intermediate energies (> 100 MeV/nucleon) and at forward scattering angles including 0o, where Tz = +1 → 0 GT transitions from the Jπ = 0+ ground state of 26Mg to the Jπ = 1+ excited states in 26Al were extended to the excitation energy (Ex) of 9 MeV. (author)
Isobar contributions to the imaginary part of the optical-model potential for finite nuclei
A recently developed non-relativistic method for calculating the nucleon optical-model potential has been employed to evaluate the contributions from isobaric degrees of freedom to the imaginary part of the nucleon optical-model potential. To evaluate the imaginary part of the optical-model potential, the authors include the contributions from terms to second order in the Brueckner G-matrix with and without the inclusion of isobars Δ. Results for 16O are presented in this work. The contributions to the imaginary part are given by the two-particle-one-hole (2p1h) and three-particle-two-hole (3p2h) diagrams. The latter contributes at negative energies only and the contribution from isobar intermediate states is rather small. The 2p1h receives significant contributions from isobars at energies near the resonance and above the threshold for the excitation of ΔΔ states. In particular, the importance of ΔΔ configurations is rather sensitive to the treatment of short-range correlations. The parameterization of the self-energy in terms of local potentials is discussed. The depletion of the occupation of the single-particle orbits due to nucleon-nucleon correlations and Δ excitations is evaluated. 49 refs., 14 figs., 3 tabs
Gao, Jun; Zhao, Weihua; Zhang, Xi; Nong, Luming; Zhou, Dong; Lv, Zhengxiang; Sheng, Yonghua; Wu, Xingbiao
2014-01-01
Objectives Using magnetic resonance imaging (MRI), we analyzed the efficacy of the posterior approach lumbar ISOBAR TTL internal fixation system for the dynamic fixation of intervertebral discs, with particular emphasis on its effects on degenerative intervertebral disc disease. Methods We retrospectively compared the MRIs of 54 patients who had previously undergone either rigid internal fixation of the lumbar spine or ISOBAR TTL dynamic fixation for the treatment of lumbar spondylolisthesis....
Delta(1232) isobar excitations and the ground state of nuclei
Frick, T; Kaiser, S.; Müther, Herbert; Polls Martí, Artur; Entem, D R; Machleidt, R.
2002-01-01
The influence of $\\Delta$ isobar components on the ground state properties of nuclear systems is investigated for nuclear matter as well as finite nuclei. Many-body wave functions, including isobar configurations, and binding energies are evaluated employing the framework of the coupled-cluster theory. It is demonstrated that the effect of isobar configurations depends in a rather sensitive way on the model used for the baryon-baryon interaction. As examples for realistic baryon-baryon intera...
Delta-isobar magnetic form factor in QCD
Belyaev, V M
1993-01-01
We consider the QCD sum rules approach for Delta-isobar magnetic form factor in the infra-red region $0isobar magnetic moment.
Isobar Separators for Radioactive Ion Beam Facilities
Garrett, J D; Wollnik, H
1998-10-05
A radioactive ion beam facility - in short a RIB facility - produces ions of short-lived nuclei and accelerates them to energies of 0.1...10 MeV per nucleon or even higher. In this process it is important that the resulting RIB beams are free from nuclei of neighboring isobars or of neighboring elements. This task requires the production and ionization of the nuclei of interest as well as separating them from all others with a high-mass resolving power and small-mass cross contaminations. When constructing such a facility it also is very important to find ways that allow the accelerated ions to be provided to different experiments at least quasi simultaneously.
Isobaric multiplet mass equation in the $A=31$ $T = 3/2$ quartets
Bennett, M B; Brown, B A; Liddick, S N; Pérez-Loureiro, D; Bardayan, D W; Chen, A A; Chipps, K A; Fry, C; Glassman, B E; Langer, C; Larson, N R; McNeice, E I; Meisel, Z; Ong, W; O'Malley, P D; Pain, S D; Prokop, C J; Schwartz, S B; Suchyta, S; Thompson, P; Walters, M; Xu, X
2016-01-01
The observed mass excesses of analog nuclear states with the same mass number $A$ and isospin $T$ can be used to test the isobaric multiplet mass equation (IMME), which has, in most cases, been validated to a high degree of precision. A recent measurement [Kankainen et al., Phys. Rev. C 93 041304(R) (2016)] of the ground-state mass of $^{31}$Cl led to a substantial breakdown of the IMME for the lowest $A = 31, T = 3/2$ quartet. The second-lowest $A = 31, T = 3/2$ quartet is not complete, due to uncertainties associated with the identity of the $^{31}$S member state. Using a fast $^{31}$Cl beam implanted into a plastic scintillator and a high-purity Ge $\\gamma$-ray detection array, $\\gamma$ rays from the $^{31}$Cl$(\\beta\\gamma)$$^{31}$S sequence were measured. Shell-model calculations using USDB and the recently-developed USDE interactions were performed for comparison. Isospin mixing between the $^{31}$S isobaric analog state (IAS) at 6279.0(6) keV and a nearby state at 6390.2(7) keV was observed. The second ...
Method of Measurement Isobaric Heat Capacity of the Organic Liquid
Yu.A. Neruchev
2013-12-01
Full Text Available A technique for measuring the heat capacity of liquids on modernized authors the installation of IT-Cp-400 is considered. The results of measurements the isobaric heat capacity of some bromosubstituted n-alkanes is presented.
Jungmann, C.R.; Weigmann, H. (Commission of the European Communities, Geel (Belgium). Central Bureau for Nuclear Measurements); Mewissen, L.; Poortmans, F. (Centre d' Etude de l' Energie Nucleaire, Mol (Belgium)); Cornels, E. (Rijksuniversitair Centrum te Antwerpen (Belgium)); Theobald, J.P. (Technische Hochschule Darmstadt (Germany, F.R.). Inst. fuer Kernphysik)
1982-09-27
Neutron transmission experiments were performed on /sup 32/S between 0.18 MeV and 19 MeV and differential elastic scattering experiments up to 2 MeV. The resonance parameters, including spin and parity, were determined up to 1.7 MeV. The distribution of neutron strength was determined for ssub(1/2), psub(1/2), psub(3/2), dsub(3/2), dsub(5/2) and f-wave levels, and is compared to recent model calculations. The isotopic purity of some possible T = 3/2 isobaric analog states was deduced from their neutron widths.
Isobar configurations: $\\Delta N$ correlations versus the independent particle model
Glavanakov, I. V.; Tabachenko, A. N.
2014-01-01
We present a comparative analysis of two models for the $A( {\\gamma,\\,\\pi N})B$ reaction, which take into account the isobar configurations in the ground state of the nuclei: the $\\Delta N$ correlation model and the quasifree pion photoproduction model. The considered models differ in their descriptions of the nucleus states. The $\\Delta N$ correlation model takes into account the dynamic correlations of the nucleon and isobar formed in the virtual transition $NN \\to \\Delta N$, and in the qua...
Sampling the isothermal-isobaric ensemble by Langevin dynamics
Gao, Xingyu; Fang, Jun; Wang, Han
2016-01-01
We present a new method of conducting molecular dynamics simulation in isothermal-isobaric ensemble based on Langevin equations of motion. The stochastic coupling to all particle and cell degrees of freedoms is introduced in a correct way, in the sense that the stationary configurational distribution is proved to be in consistent with that of the isothermal-isobaric ensemble. In order to apply the proposed method in computer simulations, a second order symmetric numerical integration scheme i...
The ILIAS project for selective isobar suppression by laser photodetachment
Forstner, Oliver; Andersson, Pontus; Hanstorp, Dag; Lahner, Johannes; Martschini, Martin; Pitters, Johanna; Priller, Alfred; Steier, Peter; Golser, Robin
2015-10-01
Laser photodetachment is the process when the extra electron of a negative ion is removed by means of laser radiation. This can happen only if the photon energy is larger than the electron affinity of the ion. The process can be used in mass spectrometry to selectively suppress unwanted isobars, provided that the electron affinity of the unwanted isobar is lower than that of the isobar under investigation. At the Ion Laser InterAction Setup (ILIAS) at the University of Vienna laser photodetachment of negative atomic and molecular ions is studied and its applicability for selective isobar suppression in accelerator mass spectrometry (AMS) is evaluated. The setup provides mass separated beams of negative ions with energies up to 30 keV. Negative ions are produced in a Middleton type cesium sputter ion source, mass selected and overlapped with a strong continuous wave laser beam. In order to extend the interaction time of ions and laser, the ion beam is decelerated to thermal energies in a gas-filled radio frequency quadrupole cooler. For an appropriate choice of the photon energy, unwanted isobars are neutralized while the isobar of interest is unaffected and remains negatively charged. A description of the ILIAS setup and results from the commissioning phase of the RFQ cooler are presented. Up to 8% ion beam transmission could be achieved after a recent redesign of the extraction system. Furthermore first results of photodetachment experiments of 63Cu- within the RFQ cooler are presented.
Chang, Yue; Sun, C. P.
2011-01-01
We study a hybrid nano-mechanical system coupled to a spin ensemble as a quantum simulator to favor a quantum interference effect, the electromagnetically induced transparency (EIT). This system consists of two nano-mechanical resonators (NAMRs), each of which coupled to a nuclear spin ensemble. It could be regarded as a crucial element in the quantum network of NAMR arrays coupled to spin ensembles. Here, the nuclear spin ensembles behave as a long-lived transducer to store and transfer the ...
Hayai, Aya; Maeda, Yusuke; Ueno, Yoshihito
2016-08-01
Here, we report the synthesis of a fluorescence resonance energy transfer (FRET)-based probe for single nucleotide polymorphism (SNP) typing. The probe contains a fluorescent tricyclic base, 8-amino-3-(2,3-dihydroxypropyl)imidazo[4',5':5,6]pyrido[2,3-d]pyrimidine, as a donor molecule and 7-diethylaminocoumarin-3-carboxylic acid as an acceptor molecule. FRET was observed between the donor and acceptor molecules on the probe. The identity of the target bases on DNA and RNA strands could be determined using the probe. PMID:27329795
It has been shown that IAS, DIAS, CS, and DCS can simultaneously have n-n, n-p, and p-p halo components in their wave functions. Differences in halo structure of the excited and ground states can result in the formation of isomers (halo-isomers). Both the Borromean and tango halo types can be observed for n-p configurations of atomic nuclei. The structure of the ground and excited states with different isospin quantum number in halo like nuclei is discussed. B(Mλ) and B(Eλ) for γ-transitions in 6,7,8Li, 8,9,10Be, 8,10,11B, 10,11,12,13,14C, 13,14,15,16,17N, 15,16,17,19O, and 17F are analyzed. Special attention is given to nuclei whose ground state does not exhibit halo structure but the excited state may have one
Izosimov, I. N., E-mail: izosimov@jinr.ru [Joint Institute for Nuclear Research, 141980 Dubna (Russian Federation)
2015-10-15
It has been shown that IAS, DIAS, CS, and DCS can simultaneously have n-n, n-p, and p-p halo components in their wave functions. Differences in halo structure of the excited and ground states can result in the formation of isomers (halo-isomers). Both the Borromean and tango halo types can be observed for n-p configurations of atomic nuclei. The structure of the ground and excited states with different isospin quantum number in halo like nuclei is discussed. B(Mλ) and B(Eλ) for γ-transitions in {sup 6,7,8}Li, {sup 8,9,10}Be, {sup 8,10,11}B, {sup 10,11,12,13,14}C, {sup 13,14,15,16,17}N, {sup 15,16,17,19}O, and {sup 17}F are analyzed. Special attention is given to nuclei whose ground state does not exhibit halo structure but the excited state may have one.
Coulomb displacement energies between analog levels for 44 < = A < = 239
Experimental Coulomb displacement energie ΔEsub(C) between isobaric analog levels are tabulated for 44 <- A <- 239, extending recent work in which similar data were presented for 3 <- A <- 45. An overall parametrization in anti-Z/A sup(1/3) and uniform radius parameters rsub(o) are given
The role of medium corrections in isovector excitations induced by the (p,n) reaction near 120 MeV is examined in light of the preceding Comment by Bauhoff which addresses the issue of making reliable estimates of the sizes of (p,n) cross sections for exciting isovector monopole resonances. To establish confidence in such estimates it is important to examine in parallel the much better understood isobaric analog of the ground state and the relative importance of medium modifications on these monopole transitions. Our examination using both density-independent and density-dependent transition operators supports the assertion of Bauhoff
Packwood, Daniel M
2012-01-01
We study a gas containing two components, a small component P and a large component Q. P is selectively heated to a high temperature and then returns to equilibrium via collisions with Q. This thermal equilibration process is analysed in a new way. We divide the kinetic energy space of the molecules of P into two regions F and D, and show that the molecules of P randomly switch (`oscillate') between the two states as time proceeds due to collisions with the molecules of Q. Initially, the molecules of P are all in the state D, however because each molecule in P collides with the molecules of Q at different times, the oscillations occur out of step with each other. There is a net destructive interference between the oscillations, and so they are not observed when monitoring the average kinetic energy of the molecules of P as a function of time. We will explain the similarities and differences between this observation and transverse relaxation processes that occur in magnetic resonance spectroscopy. This study e...
Experiments of analog states on Lead 206 and 207
This research thesis aims at verifying hypotheses according to which the spread of analog states decreases as much as nuclei are far from a double magic nucleus, under some conditions. Therefore, analog states of lead 207 and 208 have been studied by proton scattering on targets in lead 206 and 207. Some theoretical aspects of analog states of isobaric spin are presented. An experimental method of determination of excitation functions is described. Results obtained for analog states in bismuth 207-208 are discussed. Results obtained on four steady lead isotopes in different laboratories are compared
Trends in the isobaric multiplet mass equation coefficients
Isobaric analogue states (IAS) can be used to study the charge independence of the nuclear force via first order perturbation theory. In this case the IAS multiplet masses are expected to follow a quadratic form as described by the Isobaric Multiplet Mass Equation (IMME) with coefficients accessible through experimental measurements. Higher order effects are expected to appear through cubic, or higher, polynomial terms. The current IMME coefficient trends, as based on the IAS states included in the 2012 Atomic Mass Evaluation and NUBASE2012 are shown. (authors)
Trends in the Isobaric Multiplet Mass Equation Coefficients
MacCormick Marion
2014-03-01
Full Text Available Isobaric analogue states (IAS can be used to study the charge independence of the nuclear force via first order perturbation theory. In this case the IAS multiplet masses are expected to follow a quadratic form as described by the Isobaric Multiplet Mass Equation (IMME with coefficients accessible through experimental measurements. Higher order effects are expected to appear through cubic, or higher, polynomial terms. The current IMME coefficient trends, as based on the IAS states included in the 2012 Atomic Mass Evaluation and NUBASE2012 are shown.
Isobar model analysis of pi0-eta photoproduction on protons
Fix, A.; Kashevarov, V.L.; Lee, A.; Ostrick, M.
2010-01-01
Photoproduction of pi0-eta on protons in the energy range from threshold to 1.4 GeV is discussed. The data for representative angular distributions recently obtained at MAMI C are analyzed using an isobar model. The isobars considered are Delta(1232) and S11(1535) for pi0-p and eta-p states, respectively. In accordance with the results of earlier works the main features of the reaction are explained through the dominance of the D33 wave with a relatively small admixture of positive parity res...
Four-nucleon system with $\\Delta$-isobar excitation
Deltuva, A.; Fonseca, A.C.; Sauer, P. U.
2008-01-01
The four-nucleon bound state and scattering below three-body breakup threshold are described based on the realistic coupled-channel potential CD Bonn + $\\Delta$ which allows the excitation of a single nucleon to a $\\Delta$ isobar. The Coulomb repulsion between protons is included. In the four-nucleon system the two-baryon coupled-channel potential yields effective two-, three- and four-nucleon forces, mediated by the $\\Delta$ isobar and consistent with each other and with the underlying two-n...
Performance of isobaric and isotopic labeling in quantitative plant proteomics
Nogueira, Fábio C S; Palmisano, Giuseppe; Schwämmle, Veit;
2012-01-01
quantitation. In the present work, we have used LC-MS to compare an isotopic (ICPL) and isobaric (iTRAQ) chemical labeling technique to quantify proteins in the endosperm of Ricinus communis seeds at three developmental stages (IV, VI, and X). Endosperm proteins of each stage were trypsin-digested in...
Study of different components of potential in Isobaric pair collisions
The knowledge of nucleon-nucleon (NN) interaction potential in heavy ion collision (HIC) is essential in order to understand the role of different components of potential in the reaction dynamics. In the present work, we try to understand the importance of different components of potential in isobaric pair collisions having different proton and neutron content
Delta-Isobar Production in Antiproton Annihilation on the Deuteron
Lykasov, G. I.; Bussa, M. P.; Valacca, L.
1997-01-01
The annihilation of antiprotons on deuterons at rest are investigated for the case when pion-nucleon and pion-delta-isobar pairs are produced. The two-step mechanism is investigated by analysing these processes when either neutral particles and charged ones are produced. Some predictions for the branching ratios are presented.
Redundance of $\\Delta$-isobar Parameters in Effective Field Theories
Tang, Hua-Bin; Ellis, Paul J.
1996-01-01
It is shown that the off-shell parameters in the interaction Lagrangian of pions, nucleons, and $\\Delta$-isobars are redundant in the framework of effective field theories. Our results also suggest the necessity of including the $\\Delta$ as an explicit dynamical degree of freedom.
Poelstra, Klaas; Prakash, Jai; Beljaars, Eleonora; Bansal, Ruchi
2015-01-01
The invention relates to the field of medicine. Among others, it relates to biologically active analogs of interferons (IFNs) which show less unwanted side-effects and to the therapeutic uses thereof. Provided is an IFN analog, wherein the moiety mediating binding to its natural receptor is at least
Poelstra, Klaas; Prakash, Jai; Beljaars, Leonie; Bansal, Ruchi
2010-01-01
The invention relates to the field of medicine. Among others, it relates to biologically active analogs of interferons (IFNs) which show less unwanted side-effects and to the therapeutic uses thereof. Provided is an IFN analog, wherein the moiety mediating binding to its natural receptor is at least
An ion guide laser ion source for isobar-suppressed rare isotope beams.
Raeder, Sebastian; Heggen, Henning; Lassen, Jens; Ames, Friedhelm; Bishop, Daryl; Bricault, Pierre; Kunz, Peter; Mjøs, Anders; Teigelhöfer, Andrea
2014-03-01
Modern experiments at isotope separator on-line (ISOL) facilities like ISAC at TRIUMF often depend critically on the purity of the delivered rare isotope beams. Therefore, highly selective ion sources are essential. This article presents the development and successful on-line operation of an ion guide laser ion source (IG-LIS) for the production of ion beams free of isobaric contamination. Thermionic ions from the hot ISOL target are suppressed by an electrostatic potential barrier, while neutral radio nuclides effusing out are resonantly ionized by laser radiation within a quadrupole ion guide behind this barrier. The IG-LIS was developed through detailed thermal and ion optics simulation studies and off-line tests with stable isotopes. In a first on-line run with a SiC target a suppression of surface-ionized Na contaminants in the ion beam of up to six orders of magnitude was demonstrated. PMID:24689577
An ion guide laser ion source for isobar-suppressed rare isotope beams
Raeder, Sebastian, E-mail: sebastian.raeder@fys.kuleuven.be; Ames, Friedhelm; Bishop, Daryl; Bricault, Pierre; Kunz, Peter; Mjøs, Anders [TRIUMF, 4004 Wesbrook Mall, Vancouver, British Columbia V6T 2A3 (Canada); Heggen, Henning, E-mail: heggen@triumf.ca [TRIUMF, 4004 Wesbrook Mall, Vancouver, British Columbia V6T 2A3 (Canada); Institute of Applied Physics, TU Darmstadt, Schlossgartenstr. 7, 64289 Darmstadt (Germany); Lassen, Jens, E-mail: lassen@triumf.ca; Teigelhöfer, Andrea [TRIUMF, 4004 Wesbrook Mall, Vancouver, British Columbia V6T 2A3 (Canada); Department of Physics and Astronomy, University of Manitoba, Winnipeg, Manitoba R3T 2N2 (Canada)
2014-03-15
Modern experiments at isotope separator on-line (ISOL) facilities like ISAC at TRIUMF often depend critically on the purity of the delivered rare isotope beams. Therefore, highly selective ion sources are essential. This article presents the development and successful on-line operation of an ion guide laser ion source (IG-LIS) for the production of ion beams free of isobaric contamination. Thermionic ions from the hot ISOL target are suppressed by an electrostatic potential barrier, while neutral radio nuclides effusing out are resonantly ionized by laser radiation within a quadrupole ion guide behind this barrier. The IG-LIS was developed through detailed thermal and ion optics simulation studies and off-line tests with stable isotopes. In a first on-line run with a SiC target a suppression of surface-ionized Na contaminants in the ion beam of up to six orders of magnitude was demonstrated.
The non-energy weighted sum rule of M1 transitions between IAS and GT states is found to be significantly enhanced compared to the sum rule of parent nucleus. Mechanism of this enhancement is explained. Transition strengths between specific states in 48Sc, 90Nb and 208Bi are calculated to investigate whether the enhancement of the sum rule is reflected in these transitions. Measurement of M1 transitions between IAS and GT states is recommended to obtain more information on the spin-isospin response in medium and heavy nuclei. (orig.)
Remarks on the occasion of the 25. anniversary of the discovery of isobaric-analog states
Roughly 25 years ago, John Anderson, the late Calvin Wong, John McClure, and Stewart Bloom made an interesting discovery. John and his colleagues had set out to measure the systematics of nuclear temperatures. They were to look at the spectra of evaporated neutrons from compound nuclei created by proton bombardment of various targets. The evaporation spectra should be smooth functions of energy. The smooth functions were there, but there was a sharp peak superimposed. No known physical phenomenon could produce the sharp peak, so it had to be an artifact of the electronics. However, John and his colleagues convinced themselves that the time-to-pulse-height converters were working right. Well then, it had to be a contaminant in the target. Sharp peaks had been seen for isospin mirror transitions, but this target, 2351V28, had five excess neutrons, so there could not be a mirror transition. The prevailing dogma was that isotopic spin, as it was then called, was a bad quantum number because the Coulomb force was so strong. Well, John and his colleagues set about to calculate the Z of the contaminant mirror transition that would put the sharp peak at the observed energy. They found Z = 23, that of the vanadium target ! They had discovered the existence of sharp isospin multiplet states in nonmirror nuclei. Dogmas are forced to change, and jargon changes. We now accept the idea that Fermi transition strength is concentrated in a sharp state, the IAS. CVC and PCAC are good buzz acronyms that get you accelerator time from PACs. But the discovery made by Anderson, Wong, McClure, and Bloom still stands as the most important finding in nuclear structure in over a quarter of a century
Quark Substructure and Isobar Effects on Deuteron Form-Factors
Lomon, E.
2000-01-01
Elastic ed scattering, with deuteron polarization, up to high momentum transfer provides detailed information on the deuteron wave function. This determines the range dependence of the orbital and spin components of the one- and two-body currents, restricting contributions of isobar and meson-exchange currents and of quark/gluon degrees of freedom, as well as the nucleon component. The R-matrix boundary condition model combines all these effects, predicting nucleon-nucleon reactions and the d...
The ILIAS project for selective isobar suppression by Laser photodetachment
At the VERA Laboratory of the University of Vienna a facility for studying selective isobar suppression of negative ions by Laser photodetachment is currently under construction. The ILIAS (Ion Laser InterAction Setup) setup consists of a negative ion spectrometer providing mass separated beams of negatively charged atomic or molecular ions with energies up to 30 keV. The negative ions are produced in a Middleton type cesium sputter ion source. After mass selection the ions are stopped in a gas-filled radio frequency quadrupole cooler where they overlap with a strong continuous wave Laser beam. By careful selection of the photon energy unwanted isobars are neutralized while the ions of interest remain intact. With this scheme a selective suppression of isobars can be achieved. After a description of the setup and a status report of the commissioning of the negative ion spectrometer, the progress of the construction of the RFQ cooler will be presented. As an outlook the first photodetachment experiments with the RFQ cooler and a possible scheme for application of this new method to a 3 MV AMS facility will be described. (author)
an impetus or drive to that account: change, innovation, rupture, or discontinuity. Resonances: Historical Essays on Continuity and Change explores the historiographical question of the modes of interrelation between these motifs in historical narratives. The essays in the collection attempt to...... realize theoretical consciousness through historical narrative ‘in practice’, by discussing selected historical topics from Western cultural history, within the disciplines of history, literature, visual arts, musicology, archaeology, philosophy, and theology. The title Resonances indicates the overall...
Proton resonance elastic scattering of $^{30}$Mg for single particle structure of $^{31}$Mg
The single particle structure of $^{31}$Mg, which is located in the so-called “island of inversion”, will be studied through measuring Isobaric Analog Resonances (IARs) of bound states of $^{31}$Mg. They are located in the high excitation energy of $^{31}$Al. We are going to determine the spectroscopic factors and angular momenta of the parent states by measuring the excitation function of the proton resonance elastic scattering around 0 degrees in the laboratory frame with around 3 MeV/nucleon $^{30}$Mg beam. The present study will reveal the shell evolution around $^{32}$Mg. In addition, the spectroscopic factor of the (7/2)$^{−}$ state which was not yet determined experimentally, may allow one to study the shape coexistence in this nucleus.
Pion charge-exchange reactions: The analog state transitions
The general features of pion charge-exchange reactions leading to nuclear-isobaric-analog states (IAS) and double-isobaric-analog states (DIAS), as they have emerged from studies over the past ten years, are reviewed. The energy range investigated is 20 to 550 MeV for IAS transitions and 20 to 300 MeV for DIAS transitions. These data are seen to play an important role in characterizing the pion optical potential, in determining the Δ-N interaction in nuclei, and in the study of nucleon correlations in nuclei. Recent progress achieved in understanding the role of such correlations in double-charge-exchange reactions is reviewed. 55 refs., 43 figs., 3 tabs
Hofmann, R.B. [Center for Nuclear Waste Regulatory Analyses, San Antonio, TX (United States)
1995-09-01
Analogs are used to understand complex or poorly understood phenomena for which little data may be available at the actual repository site. Earthquakes are complex phenomena, and they can have a large number of effects on the natural system, as well as on engineered structures. Instrumental data close to the source of large earthquakes are rarely obtained. The rare events for which measurements are available may be used, with modfications, as analogs for potential large earthquakes at sites where no earthquake data are available. In the following, several examples of nuclear reactor and liquified natural gas facility siting are discussed. A potential use of analog earthquakes is proposed for a high-level nuclear waste (HLW) repository.
Improvement of non-isobaric model for shock ignition
In this paper, improved relations of total fuel energy, fuel gain, hot-spot radius and total areal density in a non-isobaric model of fuel assembly have been derived and compared with the numerical results of [J. Schmitt, J.W. Bates, S.P. Obenschain, S.T. Zalesak, D.E. Fyfe, Phys. Plasmas 17, 042701 (2010); S. Atzeni, A. Marocchino, A. Schiavi, G. Schurtz, New J. Phys. 15, 045004 (2013)] and several simulations performed by MULTI-1D radiation hydrodynamic code for shock ignition scenario. Our calculations indicate that the approximations made by [M.D. Rosen, J.D. Lindl, A.R. Thiessen, LLNL Laser Program Annual Report, UCRL-50021-83, pp. 3-5 (1983); J. Schmitt, J.W. Bates, S.P. Obenschain, S.T. Zalesak, D.E. Fyfe, Phys. Plasmas 17, 042701 (2010)] for the calculation of burn-up fraction are not accurate enough to give results consistent with simulations. Therefore, we have introduced more appropriate approximations for the burn-up fraction and total areal density of the fuel that are in more agreement with simulation results of shock ignition. Meanwhile, it is shown that the related formulas of the non-isobaric model for total fuel energy, fuel gain and also hot-spot radius cannot determine the model parameters independently, but improved model choose a better selection and less restrictions on determination of the parameters for the non-isobaric model. Such derivations can be used in theoretical studies of the ignition conditions and burn-up fraction of the fuel in shock ignition scenario. (authors)
Effects of consistent and inconsistent isobar coupling in the nuclear medium
Korpa, C. L.
2011-01-01
We investigate effects of consistent (conserving the number of degrees of freedom) and inconsistent pion-nucleon-isobar couplings on the isobar propagator in vacuum and in nuclear medium. Using the consistent coupling in conjunction with a convenient basis leads to significant simplification of the isobar vacuum and in-medium self energy and dressed propagator compared to the case of inconsistent interaction. The higher-derivative nature of the consistent interaction requires a suitable compe...
Covariant and self consistent vertex corrections for pions and isobars in nuclear matter
Korpa, C. L.; Lutz, M. F. M.; Riek, F.
2008-01-01
We evaluate the pion and isobar propagators in cold nuclear matter self consistently applying a covariant form of the isobar-hole model. Migdal's vertex correction effects are considered systematically in the absence of phenomenological soft form factors. Saturated nuclear matter is modeled by scalar and vector mean fields for the nucleon. It is shown that the short-range dressing of the pi N Delta vertex has a significant effect on the pion and isobar properties. Using realistic parameters s...
Sensitive dependence of isotope and isobar distribution of limiting temperatures on symmetry energy
Ou, Li; Liu, Min; Li, Zhuxia
2013-01-01
The mass, isotope, and isobar distributions of limiting temperatures for finite nuclei are investigated by using a thermodynamics approach together with the Skyrme energy density functional. The relationship between the width of the isotope (isobar) distribution of limiting temperatures and the stiffness of the density dependence of the symmetry energy clearly is observed. The nuclear symmetry energy with smaller slope parameter $L_{\\rm{sym}}$ causes a wider the isotope (isobar) distribution ...
Laser ion source for isobaric heavy ion collider experiment
Kanesue, T., E-mail: tkanesue@bnl.gov; Okamura, M. [Collider-Accelerator Department, Brookhaven National Laboratory, Upton, New York 11973 (United States); Kumaki, M. [Research Institute for Science and Engineering, Waseda University, Tokyo 169-8555 (Japan); Nishina Center for Accelerator-Based Science, RIKEN, Saitama 351-0198 (Japan); Ikeda, S. [Nishina Center for Accelerator-Based Science, RIKEN, Saitama 351-0198 (Japan); Interdisciplinary Graduate School of Science and Engineering, Tokyo Institute of Technology, Kanagawa 226-8503 (Japan)
2016-02-15
Heavy-ion collider experiment in isobaric system is under investigation at Relativistic Heavy Ion Collider. For this experiment, ion source is required to maximize the abundance of the intended isotope. The candidate of the experiment is {sup 96}Ru + {sup 96}Zr. Since the natural abundance of particular isotope is low and composition of isotope from ion source depends on the composites of the target, an isotope enriched material may be needed as a target. We studied the performance of the laser ion source required for the experiment for Zr ions.
Laser ion source for isobaric heavy ion collider experiment
Kanesue, T.; Kumaki, M.; Ikeda, S.; Okamura, M.
2016-02-01
Heavy-ion collider experiment in isobaric system is under investigation at Relativistic Heavy Ion Collider. For this experiment, ion source is required to maximize the abundance of the intended isotope. The candidate of the experiment is 96Ru + 96Zr. Since the natural abundance of particular isotope is low and composition of isotope from ion source depends on the composites of the target, an isotope enriched material may be needed as a target. We studied the performance of the laser ion source required for the experiment for Zr ions.
QCD sum rules for $\\Delta$ isobar in nuclear matter
Jin, Xuemin
1994-01-01
The self-energies of $\\Delta$ isobar propagating in nuclear matter are calculated using the finite-density QCD sum-rule methods. The calculations show that the Lorentz vector self-energy for the $\\Delta$ is significantly smaller than the nucleon vector self-energy. The magnitude of the $\\Delta$ scalar self-energy is larger than the corresponding value for the nucleon, which suggests a strong attractive net self-energy for the $\\Delta$; however, the prediction for the scalar self-energy is ver...
Constraints on the relativistic mean field of $\\Delta$-isobar in nuclear matter
Kosov, D. S.; C. Fuchs; Martemyanov, B. V.; Faessler, Amand
1997-01-01
The effects of the presence of $\\Delta$-isobars in nuclear matter are studied in the framework of relativistic mean-field theory. The existence of stable nuclei at saturation density imposes constraints on the $\\Delta$-isobar self-energy and thereby on the mean-field coupling constants of the scalar and vector mesons with $\\Delta$-isobars. The range of possible values for the scalar and vector coupling constants of $\\Delta$-isobars with respect to the nucleon coupling is investigated and comp...
2008-01-01
In this paper, a series of C-terminal modified analogs of endomorphin-2 is investigated using ESI-FT-ICR-MS. Some b, y″, a, and internal ions are found in the CID spectra and slight mass differ- ences between the calculated and observed results are obtained. Moreover, if the C-terminal modified group is t-butyloxy, it can lose butene through McLafferty rearrangement. FT-ICR MS shows its power in peptide sequencing successfully helping us obtain the structure of peptide analogs.
Hard breakup of the deuteron into two Δ isobars
We study high-energy photodisintegration of the deuteron into two Δ isobars at large center of mass angles within the QCD hard rescattering model (HRM). According to the HRM, the process develops in three main steps: the photon knocks a quark from one of the nucleons in the deuteron; the struck quark rescatters off a quark from the other nucleon sharing the high energy of the photon; then the energetic quarks recombine into two outgoing baryons which have large transverse momenta. Within the HRM, the cross section is expressed through the amplitude of pn→ΔΔ scattering which we evaluated based on the quark-interchange model of hard hadronic scattering. Calculations show that the angular distribution and the strength of the photodisintegration is mainly determined by the properties of the pn→ΔΔ scattering. We predict that the cross section of the deuteron breakup to Δ++Δ- is 4-5 times larger than that of the breakup to the Δ+Δ0 channel. Also, the angular distributions for these two channels are markedly different. These can be compared with the predictions based on the assumption that two hard Δ isobars are the result of the disintegration of the preexisting ΔΔ components of the deuteron wave function. In this case, one expects the angular distributions and cross sections of the breakup in both Δ++Δ- and Δ+Δ0 channels to be similar.
Nested Sampling (NS) is a powerful athermal statistical mechanical sampling technique that directly calculates the partition function, and hence gives access to all thermodynamic quantities in absolute terms, including absolute free energies and absolute entropies. NS has been used predominately to compute the canonical (NVT) partition function. Although NS has recently been used to obtain the isothermal-isobaric (NPT) partition function of the hard sphere model, a general approach to the computation of the NPT partition function has yet to be developed. Here, we describe an isobaric NS (IBNS) method which allows for the computation of the NPT partition function of any atomic system. We demonstrate IBNS on two finite Lennard-Jones systems and confirm the results through comparison to parallel tempering Monte Carlo. Temperature-entropy plots are constructed as well as a simple pressure-temperature phase diagram for each system. We further demonstrate IBNS by computing part of the pressure-temperature phase diagram of a Lennard-Jones system under periodic boundary conditions
Wilson, Blake A; Gelb, Lev D; Nielsen, Steven O
2015-10-21
Nested Sampling (NS) is a powerful athermal statistical mechanical sampling technique that directly calculates the partition function, and hence gives access to all thermodynamic quantities in absolute terms, including absolute free energies and absolute entropies. NS has been used predominately to compute the canonical (NVT) partition function. Although NS has recently been used to obtain the isothermal-isobaric (NPT) partition function of the hard sphere model, a general approach to the computation of the NPT partition function has yet to be developed. Here, we describe an isobaric NS (IBNS) method which allows for the computation of the NPT partition function of any atomic system. We demonstrate IBNS on two finite Lennard-Jones systems and confirm the results through comparison to parallel tempering Monte Carlo. Temperature-entropy plots are constructed as well as a simple pressure-temperature phase diagram for each system. We further demonstrate IBNS by computing part of the pressure-temperature phase diagram of a Lennard-Jones system under periodic boundary conditions. PMID:26493898
Wilson, Blake A.; Nielsen, Steven O. [Department of Chemistry, University of Texas at Dallas, Richardson, Texas 75080 (United States); Gelb, Lev D. [Department of Materials Science and Engineering, University of Texas at Dallas, Richardson, Texas 75080 (United States)
2015-10-21
Nested Sampling (NS) is a powerful athermal statistical mechanical sampling technique that directly calculates the partition function, and hence gives access to all thermodynamic quantities in absolute terms, including absolute free energies and absolute entropies. NS has been used predominately to compute the canonical (NVT) partition function. Although NS has recently been used to obtain the isothermal-isobaric (NPT) partition function of the hard sphere model, a general approach to the computation of the NPT partition function has yet to be developed. Here, we describe an isobaric NS (IBNS) method which allows for the computation of the NPT partition function of any atomic system. We demonstrate IBNS on two finite Lennard-Jones systems and confirm the results through comparison to parallel tempering Monte Carlo. Temperature-entropy plots are constructed as well as a simple pressure-temperature phase diagram for each system. We further demonstrate IBNS by computing part of the pressure-temperature phase diagram of a Lennard-Jones system under periodic boundary conditions.
TWO SUPER-EARTHS ORBITING THE SOLAR ANALOG HD 41248 ON THE EDGE OF A 7:5 MEAN MOTION RESONANCE
Jenkins, J. S. [Departamento de Astronomia, Universidad de Chile, Camino el Observatorio 1515, Las Condes, Santiago, Casilla 36-D (Chile); Tuomi, M. [Center for Astrophysics, University of Hertfordshire, College Lane Campus, Hatfield, Hertfordshire, AL10 9AB (United Kingdom); Brasser, R. [Institute for Astronomy and Astrophysics, Academia Sinica, Taipei 10617, Taiwan (China); Ivanyuk, O. [Main Astronomical Observatory of National Academy of Sciences of Ukraine, 27 Zabolotnoho, Kyiv 127 03680 (Ukraine); Murgas, F., E-mail: jjenkins@das.uchile.cl [Instituto de Astrofisica de Canarias, Via Lactea, E-38205 La Laguna, Tenerife (Spain)
2013-07-01
There are a growing number of multi-planet systems known to be orbiting their host stars with orbital periods that place them in mean motion resonances (MMRs). These systems are generally in first-order resonances and dynamical studies have focused their efforts on understanding the origin and evolution of such dynamically resonant commensurabilities. Here we report the discovery of two super-Earths that are close to a second-order dynamical resonance orbiting the metal-poor ([Fe/H] = -0.43 dex) and inactive G2V star HD 41428. We analyzed 62 HARPS archival radial velocities for this star that, until now, exhibited no evidence for planetary companions. Using our new Bayesian Doppler signal detection algorithm, we find two significant signals in the data, with periods of 18.357 days and 25.648 days, indicating they could be part of a 7:5 second-order MMR. Both semi-amplitudes are below 3 m s{sup -1} and the minimum masses of the pair are 12.3 and 8.6 M{sub Circled-Plus }, respectively. Our simulations found that apsidal alignment stabilizes the system, and even though libration of the resonant angles was not seen, the system is affected by the presence of the resonance and could still occupy the 7:5 commensurability, which would be the first planetary configuration in such a dynamical resonance. Given the multitude of low-mass multi-planet systems that will be discovered in the coming years, we expect that more of these second-order resonant configurations will emerge from the data, highlighting the need for a better understanding of the dynamical interactions between forming planetesimals.
Fast separation of isobars on ISOL facility collector
Volatility of Rb, Sr, Y, Ba, some rare earth elements, Ra, Ac and Th, implantated in a tantalum collector with 45 keV energy is investigated. The collector heating during 180 s in vacuum results in the separation of implantated elements. Separation coefficients are as follows: sup(α)Sr/Rb=14/1390 K/, sup(α)Y/Sr=28/1680 K/, sup(α)La/Ba=8/1590 K/, sup(α)Sm/Eu=3/1470 K/, sup(α)Gd/Eu=22/1620 K/, sup(α)Tm/Yb=8/1600 K/, sup(α)Lu/Yb=38/1700 K/ and sup(α)Ac/Ra=sup(α)Th/Ra=030/1650 K/. The contributions of diffusion and desorption to the volatility process of implantated elements and prospects for application of the proposed method for separation of isobars on ISOL Facility collector are discussed
The isobaric multiplet mass equation for A≤71 revisited
Accurate mass determination of short-lived nuclides by Penning-trap spectrometers and progress in the spectroscopy of proton-rich nuclei have triggered renewed interest in the isobaric multiplet mass equation (IMME). The energy levels of the members of T=1/2,1,3/2, and 2 multiplets and the coefficients of the IMME are tabulated for A≤71. The new compilation is based on the most recent mass evaluation (AME2011) and it includes the experimental results on energies of the states evaluated up to end of 2011. Taking into account the error bars, a significant deviation from the quadratic form of the IMME for the A=9,35 quartets and the A=32 quintet is observed
Electromagnetic properties of the nucleon and Delta(1232)-isobar in chiral EFT
Recent lattice QCD and baryon chiral perturbation theory results show some discrepancies, e.g. in the nucleon iso-vector Pauli- and Dirac-radii. In this talk we discuss present progress in the study of the pion-mass and volume dependence of nucleon and Delta(1232)-isobar electromagnetic observables, namely: the nucleon iso-vector anomalous magnetic moment, Dirac- and Pauli-radii and the Delta(1232)-isobar electric quadrupole, magnetic dipole and magnetic octupole moments. In the case of the Delta(1232)-isobar we confront the situation of unstable particles in an external electromagnetic field.
Obach, R Scott; Walker, Gregory S; Brodney, Michael A
2016-05-01
Replacement of hydrogen with fluorine is a useful drug design strategy when decreases in cytochrome P450 (P450) metabolic lability are needed. In this paper, a facile two-step method of inserting fluorine into metabolically labile sites of drug molecules is described that utilizes less than 1 mg of starting material and quantitative NMR spectroscopy to ascertain the structures and concentrations of products. In the first step, hydroxyl metabolites are biosynthesized using human P450 enzymes, and in the second step these metabolites are subjected to deoxyfluorination using diethylaminosulfur trifluoride (DAST). The method is demonstrated using midazolam, celecoxib, ramelteon, and risperidone as examples and CYP3A5, 2C9, 1A2, and 2D6 to catalyze the hydroxylations. The drugs and their fluoro analogs were tested for metabolic lability. 9-Fluororisperidone and 4'-fluorocelecoxib were 16 and 4 times more metabolically stable than risperidone and celecoxib, respectively, and 2-fluororamelteon and ramelteon were metabolized at the same rate. 1'-Fluoromidazolam was metabolized at the same rate as midazolam by CYP3A4 but was more stable in CYP3A5 incubations. The P450-catalyzed sites of metabolism of the fluorine-containing analogs were determined. Some of the metabolites arose via metabolism at the fluorine-substituted carbon, wherein the fluorine was lost to yield aldehydes. In summary, this method offers an approach whereby fluorine can be substituted in metabolically labile sites, and the products can be tested to determine whether an enhancement in metabolic stability was obtained. PMID:26921388
The invention relates to devices for modelling the space-dependent kinetics of a nuclear reactor. It can be advantageously used in studying the dynamics of the neutron field in the core to determine the effect of the control rods on the power distribution in the core, for training purposes. The proposed analog model of a nuclear reactor comprises operational amplifiers and a grid of resistors simulating neutron diffusion. Connected to the grid nodes are supply resistors modelling absorption and multiplication of neutrons. This is achieved by that, in the proposed model, all resistors through which power is supplied to the grid nodes are interconnected by their other leads and coupled to the output of the amplifier unit common for all nodes. Therewith, the amlifier unit models the transfer function of a ''point'' reactor. Connected to the input of this unit which includes two to four amplifiers are resistors for addition of signals with a grid node. Coupled to the grid nodes via additional resistors are voltage sources simulating reactivity
Test the chiral magnetic effect with isobaric collisions
Deng, Wei-Tian; Ma, Guo-Liang; Wang, Gang
2016-01-01
The quark-gluon matter produced in relativistic heavy-ion collisions may contain local domains in which P and CP symmetries are not preserved. When coupled with an external magnetic field, such P- and CP-odd domains will generate electric currents along the magnetic field --- a phenomenon called the chiral magnetic effect (CME). Recently, the STAR Collaboration at RHIC and the ALICE Collaboration at the LHC released data of charge-dependent azimuthal-angle correlators with features consistent with the CME expectation. However, the experimental observable is contaminated with significant background contributions from elliptic-flow-driven effects, which makes the interpretation of the data ambiguous. In this Letter, we show that the collisions of isobaric nuclei, $^{96}_{44}$Ru + $^{96}_{44}$Ru and $^{96}_{40}$Zr + $^{96}_{40}$Zr, provide an ideal tool to disentangle the CME signal from the background effects. Our simulation demonstrates that the two collision types at $\\sqrt{s_{\\rm NN}}=200$ GeV have more than...
Theoretical estimation of the isobaric heat capacity cp of refrigerant
Based on theory of equation of state and residual function method, a theoretical development for estimating the isobaric heat capacity cp of refrigerant is carried out. Regarding cp as a derived thermodynamic property, then according to the general relation of the thermodynamics, two formulas for calculating cp of real fluid are derived from cubic Peng-Robinson equation of state (P-REoS) and modificatory Martin-Hou equation of state (M-H81EoS). Ten pure refrigerants and four mixed refrigerants are chosen to make detailed numerical calculation and theoretical analysis. A wide comparison with experimental data is made, a conclusion can be drawn that in vapor-phase region, the estimation precision is about 3% for both equation modelings; while in liquid-phase region, M-H81EoS modeling has predominance with an estimation precision of less than 10%. Moreover, comparison of cp values between estimated ones and that derived from popular REFPROP software is also conducted, the distribution of cp along with temperature are investigated for vapor and liquid phase respectively. The results show that all cp values present a monotonically increasing trend with temperature
The three-nucleon bound state with isobaric and pionic degrees of freedom
Wave function components containing a single Δ-isobar are included in the calculation of the three-nucleon bound states. The two-nucleon interaction acts in all partial waves up to total angular momentum I=2. The presence of a Δ-isobar increases the three-nucleon binding energy by about 0.3 MeV, 0.6 MeV repulsion being a dispersive two-body effect, 0.9 MeV attraction arising from the three-nucleon force with intermediate Δ-isobar. The effect of the Δ on the three-nucleon charge and magnetic form factors is investigated. The possibility of treating the Δ-isobar as a dynamic pion-nucleon system in nuclear structure and nuclear-structure corrections beyond single Δ excitation in the coupled channel approach are also discussed
Significance of isobaric interferences in Hf isotopic analyses of geological samples
Sláma, Jiří; Košler, J.
- : I C P Information Newsletter, Inc, 2005. W51-W51. [European Winter Conference on Plasma Spectrochemistry WINTER 2005. 30.01.2005-03.02.2005, Budapest] Keywords : isobaric interferences * Hf isotopes * analytical uncertainties Subject RIV: DD - Geochemistry
Fuel Application Efficiency in Ideal Cycle of Gas Turbine Plant with Isobaric Heat Supply
A. Nesenchuk; A. Begliak; T. Ryzhova; D. Shklovchik; V. Begliak; A. Аbrazovsky
2014-01-01
The paper reveals expediency to use in prospect fuels with maximum value Qнр∑Vi and minimum theoretical burning temperature in order to obtain maximum efficiency of the ideal cycle in GTP with isobaric heat supply.
On the polarization effects in (p,n) reactions between the A=48 isobarical states
Isakov, V. I.
2002-01-01
Isotopical dependence of spin-orbit splitting discovered by us in spectra of heavy nuclei close to doubly magic ones is checked in polarization effects arising in charge exchange (p,n) reaction between the A=48 isobarical states.
Thingholm, Tine E; Palmisano, Giuseppe; Kjeldsen, Frank;
2010-01-01
labeling of proteins and peptides for in vitro cell culture systems (stable isotope labeling using amino acids in cell culture, SILAC) or isobaric peptide labels such as isobaric tags for relative and absolute quantitation (iTRAQ) and tandem mass tags (TMT) for both in vitro and in vivo systems. These...... quantitation strategies have also been successfully applied to phosphoproteomics studies for the investigation of signal transduction pathways. Here we describe major drawbacks associated with isobaric labeling for the identification and quantitation of phosphopeptides using electrospray tandem mass...... spectrometry. Phosphopeptide derivatization with isobaric tags results in significantly greater charging in electrospray ionization. This reduces phosphopeptide identification efficiency with multistage activation and HCD MS/MS by more than 50% and may contribute to the discrepancy observed between...
Due to quantum size effects (QSEs), the isobaric thermal expansion coefficient and isothermal compressibility well defined for macroscopic systems are invalid for finite-size systems. The two parameters are redefined and calculated for a finite-size ideal Fermi gas confined in a rectangular container. It is found that the isobaric thermal expansion coefficient and isothermal compressibility are generally anisotropic, i.e., they are generally different in different directions. Moreover, it is found the thermal expansion coefficient may be negative in some directions under the condition that the pressures in all directions are kept constant. - Highlights: • Isobaric thermal expansion coefficient and isothermal compressibility are redefined. • The two parameters are calculated for a finite-size ideal Fermi gas. • The two parameters are generally anisotropic for a finite-size system. • Isobaric thermal expansion coefficient may be negative in some directions
Tavousi, Alireza; Mansouri-Birjandi, Mohammad Ali; Saffari, Mehdi
2016-09-01
Implementing of photonic sampling and quantizing analog-to-digital converters (ADCs) enable us to extract a single binary word from optical signals without need for extra electronic assisting parts. This would enormously increase the sampling and quantizing time as well as decreasing the consumed power. To this end, based on the concept of successive approximation method, a 4-bit full-optical ADC that operates using the intensity-dependent Kerr-like nonlinearity in a two dimensional photonic crystal (2DPhC) platform is proposed. The Silicon (Si) nanocrystal is chosen because of the suitable nonlinear material characteristic. An optical limiter is used for the clamping and quantization of each successive levels that represent the ADC bits. In the proposal, an energy efficient optical ADC circuit is implemented by controlling the system parameters such as ring-to-waveguide coupling coefficients, the ring's nonlinear refractive index, and the ring's length. The performance of the ADC structure is verified by the simulation using finite difference time domain (FDTD) method.
Deltuva, A.; Yuan, L. P.; Adam Jr., J.; Fonseca, A.C.; Sauer, P. U.
2003-01-01
Radiative nucleon-deuteron capture and two- and three-body photo disintegration of the three-nucleon bound state are described. The description uses the purely nucleonic charge-dependent CD-Bonn potential and its coupled-channel extension CD Bonn + $\\Delta$. The $\\Delta$-isobar excitation yields an effective three-nucleon force and effective two- and three-nucleon currents besides other $\\Delta$-isobar effects; they are mutually consistent. Exact solutions of three-particle equations are empl...
Photoproduction of $\\pi^+p$ Pairs on the $^{16}$O Nucleus and Isobar Configurations
Glavanakov, I.; Grabmayer, P.; Krechetov, Yu.; Tabachenko, A.
2013-01-01
The yield of the $^{16}$O$(\\gamma ,\\pi^{+} p)$ reaction has been measured in the region of the excitation of the $\\Delta(1232)$ isobar at high momentum transfers to the residual nuclear system. The experimental data are interpreted within the model taking into account of isobar configurations in the ground state of the $^{16}$O nucleus. Direct and exchange mechanisms of the production of pions with emission of one and two nucleons, which follow from the structures of the density matrices for ...
MS3 eliminates ratio distortion in isobaric labeling-based multiplexed quantitative proteomics
Ting, Lily; Rad, Ramin; Gygi, Steven P.; Haas, Wilhelm
2011-01-01
Quantitative mass spectrometry-based proteomics is highly versatile, but not easily multiplexed. Isobaric labeling strategies allow mass spectrometry-based multiplexed proteome quantification; however, ratio distortion due to protein quantification interference is a common effect. We present a multi-proteome model (mixture of human and yeast proteins) in a 6-plex isobaric labeling system to fully document the interference effect, and we report that a multistage MS3-based approach almost compl...
Bukhovich Y. V.
2015-09-01
Full Text Available The study of the thermo-physical properties of liquids gives an opportunity of qualitative and quantitative evaluation of condensed matter theory, phase transitions and critical phenomena. To forecast the thermo-dynamic properties of liquid natural hydrocarbons one must know the basic heat-physical characteristics in a wide range of condition parameters. We have researched specific isobaric thermal heat capacity of gas condensates of Oposhnyanskoye, Solokhovskoye, Bukharskoye, Rybalskoye, Stavropolskoye, Schebelinskoye and Yubileinoye deposits theoretically and experimentally. These substances were in liquid phase on pseudo-critical isobar in the range of temperatures from minus 40 till 100 °C. In the article the findings of the investigation are presented. The mean relative experimental error doesn’t exceed ± 1.5 %, with reliability 0.95. The universal equation expressing specific isobaric thermal heat capacity as the function of temperature and molar mass has been obtained. It describes specific isobaric thermal heat capacity on pseudo-critical isobar for investigated natural hydrocarbons with the mean relative error, which does not exceed ± 1.65 %. The use of the equation for the calculation of specific isobaric thermal heat capacity of the substances of other deposits is recommended
Chen, Wai-Kai
2009-01-01
Featuring hundreds of illustrations and references, this book provides the information on analog and VLSI circuits. It focuses on analog integrated circuits, presenting the knowledge on monolithic device models, analog circuit cells, high performance analog circuits, RF communication circuits, and PLL circuits.
Science Teachers' Analogical Reasoning
Mozzer, Nilmara Braga; Justi, Rosária
2013-08-01
Analogies can play a relevant role in students' learning. However, for the effective use of analogies, teachers should not only have a well-prepared repertoire of validated analogies, which could serve as bridges between the students' prior knowledge and the scientific knowledge they desire them to understand, but also know how to introduce analogies in their lessons. Both aspects have been discussed in the literature in the last few decades. However, almost nothing is known about how teachers draw their own analogies for instructional purposes or, in other words, about how they reason analogically when planning and conducting teaching. This is the focus of this paper. Six secondary teachers were individually interviewed; the aim was to characterize how they perform each of the analogical reasoning subprocesses, as well as to identify their views on analogies and their use in science teaching. The results were analyzed by considering elements of both theories about analogical reasoning: the structural mapping proposed by Gentner and the analogical mechanism described by Vosniadou. A comprehensive discussion of our results makes it evident that teachers' content knowledge on scientific topics and on analogies as well as their pedagogical content knowledge on the use of analogies influence all their analogical reasoning subprocesses. Our results also point to the need for improving teachers' knowledge about analogies and their ability to perform analogical reasoning.
The gas-filled magnet: An isobar separator for accelerator mass spectrometry
The most difficult problem for accelerator mass spectrometry is the rejection of stable atomic isobars. The intensity of isobaric interference is expected to become a problem for 36Cl measurements with the use of new high-intensity ion sources. Although better chemical separation may be possible through improved sample preparation, the device expected to help most with this problem is the gas-filled magnet. We tested a gas-filled Enge split-pole spectrograph combined with a multi-plate gas ionization detector for the separation of 36S from 36Cl and obtained an isobar separation of about two orders of magnitude better than that possible with the detector alone. 10 refs., 3 figs., 1 tab
Bordbar, G. H.
2001-01-01
One of the most interesting application of the many-body methods to the nuclear physics is the calculation of the properties of the nuclear matter, especially its binding energy. In this paper, we have studied the influence of Δ -isobar on the properties of the symmetrical nuclear matter using the lowest order constrained variational (LOCV) method with the V28 potential. It is shown that the inclusion of Δ- isobar substantially affect the saturation properties of the symmetrical nuclear mat...
Effect of particle fluctuation on isoscaling and isobaric yield ratio of nuclear multifragmentation
Mallik, S
2016-01-01
Isoscaling and isobaric yield ratio parameters are compared from canonical and grand canonical ensembles when applied to multifragmentation of finite nuclei. Source dependence of isoscaling parameters and source and isospin dependence of isobaric yield ratio parameters are examined in the framework of the canonical and the grand canonical models. It is found that as the nucleus fragments more, results from both the ensembles converge and observables calculated from the canonical ensemble coincide more with those obtained from the formulae derived using the grand canonical ensemble.
Superconducting circuit probe for analog quantum simulators
Du, Liang-Hui; You, J. Q.; Tian, Lin
2015-07-01
Analog quantum simulators can be used to study quantum correlation in novel many-body systems by emulating the Hamiltonian of these systems. One essential question in quantum simulation is to probe the properties of an emulated many-body system. Here we present a circuit QED scheme for probing such properties by measuring the spectrum of a superconducting resonator coupled to a quantum simulator. We first study a general framework of this approach and show that the spectrum of the resonator is directly related to the correlation function of the coupling operator between the resonator and the simulator. We then apply this scheme to a simulator of the transverse field Ising model implemented with superconducting qubits, where the resonance peaks in the resonator spectrum correspond to the frequencies of the elementary excitations. The effects of resonator damping, qubit decoherence, and resonator backaction are also discussed. This setup can be used to probe a broad range of many-body models.
Intuitive analog circuit design
Thompson, Marc
2013-01-01
Intuitive Analog Circuit Design outlines ways of thinking about analog circuits and systems that let you develop a feel for what a good, working analog circuit design should be. This book reflects author Marc Thompson's 30 years of experience designing analog and power electronics circuits and teaching graduate-level analog circuit design, and is the ideal reference for anyone who needs a straightforward introduction to the subject. In this book, Dr. Thompson describes intuitive and ""back-of-the-envelope"" techniques for designing and analyzing analog circuits, including transistor amplifi
Isospin Mixing Reveals $^{30}$P($p,\\gamma$)$^{31}$S Resonance Influencing Nova Nucleosynthesis
Bennett, M B; Brown, B A; Liddick, S N; Pérez-Loureiro, D; Bardayan, D W; Chen, A A; Chipps, K A; Fry, C; Glassman, B E; Langer, C; Larson, N R; McNeice, E I; Meisel, Z; Ong, W; O'Malley, P; Pain, S D; Prokop, C; Schatz, H; Schwartz, S B; Suchyta, S; Thompson, P; Walters, M; Xu, X
2016-01-01
The thermonuclear $^{30}$P($p,\\gamma$)$^{31}$S reaction rate is critical for modeling the final elemental and isotopic abundances of ONe nova nucleosynthesis, which affect the calibration of proposed nova thermometers and the identification of presolar nova grains, respectively. Unfortunately, the rate of this reaction is essentially unconstrained experimentally, because the strengths of key $^{31}$S proton capture resonance states are not known, largely due to uncertainties in their spins and parities. Using the $\\beta$ decay of $^{31}$Cl, we have observed the $\\beta$-delayed $\\gamma$ decay of a $^{31}$S state at $E_x = 6390.2(7)$ keV, with a $^{30}$P($p,\\gamma$)$^{31}$S resonance energy of $E_r = 259.3(8)$ keV, in the middle of the $^{30}$P($p,\\gamma$)$^{31}$S Gamow window for peak nova temperatures. This state exhibits isospin mixing with the nearby isobaric analog state (IAS) at $E_x = 6279.0(6)$ keV, giving it an unambiguous spin and parity of $3/2^+$ and making it an important $l = 0$ resonance for prot...
Masses and mean-square charge radii of isobaric 4p-quintet members with 36≤A≤64
Formulaes which allowed to calculate masses and mean-square charge radii of the members of isobaric 4p-quintets with 36≤A≤64 are derived on the basis of the rule of the equidistance of isobaric multiplet member separation (fission) energies
Lutostansky, Yu S
2015-01-01
Energies of the giant Gamow-Teller and analog resonances - $E_{\\rm G}$ and $E_{\\rm A}$, are presented, calculated using the microscopic theory of finite Fermi system. The calculated differences $\\Delta E_{\\rm G-A}=E_{\\rm G}-E_{\\rm A}$ go to zero in heavier nuclei indicating the restoration of Wigner SU(4)-symmetry. The calculated $\\Delta E_{\\rm G-A}$ values are in good agreement with the experimental data. The average deviation is 0.30 MeV for the 33 considered nuclei for which experimental data is available. The $\\Delta E_{\\rm G-A}$ values were calculated for heavy and superheavy nuclei up to the mass number $A $= 290. Using the experimental data for the analog resonances energies, the isotopic dependence of the difference of the Coulomb energies of neighboring nuclei isobars analyzed within the SU(4)-approach for more than 400 nuclei in the mass number range of $A$ = 3 - 244. The Wigner SU(4)-symmetry restoration for heavy and superheavy nuclei is confirmed. It is shown that the restoration of SU(4)-symmetr...
The newly observed Z+(4433) resonance by BELLE is believed to be a tetraquark bound state made up of (cu)(cd). We propose the bottomed analog of this bound state, namely, by replacing one of the charm quarks by a bottom quark, thus forming Zbc0,±,±±. One of the Zbc is doubly charged. The predicted mass of Zbc is around 7.6 GeV. This doubly charged bound state can be detected by its decay into Bc±π±. Similarly, we can also replace both charm quark and antiquark of the Z+(4433) by bottom quark and antiquark, respectively, thus forming Zbb the bottomonium analog of Z+(4433). The predicted mass of Zbb is about 10.7 GeV
Fuel Application Efficiency in Ideal Cycle of Gas Turbine Plant with Isobaric Heat Supply
A. Nesenchuk
2013-01-01
Full Text Available The paper reveals expediency to use in prospect fuels with maximum value Qнр∑Vi and minimum theoretical burning temperature in order to obtain maximum efficiency of the ideal cycle in GTP with isobaric heat supply.
A New Method to Treat High Anal Fistula - Bidirectional Isobaric Drainage
Zheng, Linghua; Wang, Yanmei; Zhao, Jingbo;
2016-01-01
divided into Experimental group and Control group, 60 patients in each group. The patients of Experimental group were treated using bidirectional isobaric drainage radical resection, i.e., moving internal orifice of the fistula up and making another opening at top end of fistula penetrating to the rectal...
Nuclear charge and isobar separation in a gas-filled enge split-pole magnetic spectrograph
The sepration technique is based on the fact that charge-changing processes of an ion in a gas, if they occur frequently enough in a magnetic field region, lead to trajectories determined by the average charge state of the ion in the gas. The technique has been used to separate isobaric 58Ni and 58Fe ions. 7 refs., 4 figs., 1 tab
Ma, Chun-Wang; Qiao, Chun-Yuan; Cao, Xi-Guang
2015-01-01
\\item[Background] Temperature is an important parameter in studying many important questions in heavy-ion collisions. A thermometer based on the isobaric yield ratio (IYR) has been proposed [Ma \\textit{et al.}, Phys. Rev. C \\textbf{86}, 054611 (2012) and Ma \\textit{et al.}, \\textit{ibid.}, Phys. Rev. C \\textbf{88}, 014609 (2013)]. \\item[Purpose] An improved thermometer ($T_{IB}$) is proposed based on the difference between IYRs. $T_{IB}$ obtained from isobars in different reactions will be compared. \\item[Methods] The yields of three isobars are employed in $T_{IB}$. The residual free energy of the three isobars are replaced by that of the binding energy. No secondary decay modification for odd $A$ fragment is used in $T_{IB}$. \\item[Results] The measured fragment yields in the 140$A$ MeV $^{40, 48}$Ca + $^{9}$Be ($^{181}$Ta) and $^{58, 64}$Ni + $^9$Be ($^{181}$Ta), the 1$A$ GeV $^{124, 136}$Xe + Pb, and the $^{112,124}$Sn + $^{112,124}$Sn reactions have been analyzed to obtain $T_{IB}$ from IMFs. $T_{IB}$ fr...
Sidoli, Simone; Fujiwara, Rina; Kulej, Katarzyna; Garcia, Benjamin A
2016-07-19
Phosphorylation is a post-translational modification (PTM) fundamental for processes such as signal transduction and enzyme activity. We propose to apply data-independent acquisition (DIA) using mass spectrometry (MS) to determine unexplored phosphorylation events on isobarically modified peptides. Such peptides are commonly not quantitatively discriminated in phosphoproteomics due to their identical mass. PMID:27301801
Fridén, Mikael E; Sjöberg, Per J R
2014-07-01
Flavonoids are a class of secondary plant metabolites existing in great variety in nature. Due to this variety, identification can be difficult, especially as overlapping compounds in both chromatographic separations and mass spectrometric detection are common. Methods for distinguishing isobaric flavonoids using MS(2) and MS(3) have been developed. Chromatographic separation of various plant extracts was done with RP-HPLC and detected with positive ESI-MS operated in information-dependent acquisition (IDA) mode. Two methods for the determination of flavonoid identity and substitution pattern, both featuring IDA criteria, were used together with the HPLC equipment. A third method where the collision energy was ramped utilized direct infusion. With the developed strategies, it is possible to differentiate between many isobaric flavonoids. Various classes of flavonoids were found in all of the plant extracts, in the red onion extract 45 components were detected and for 29 of them the aglycone was characterized, while the substituents were tentatively identified for 31 of them. For the strawberry extract, those numbers were 66, 30 and 60, and for the cherry extract 99, 56 and 71. The great variety of flavonoids, several of them isobaric, found in each of the extracts highlights the need for reliable methods for flavonoid characterization. Methods capable of differentiating between most of the isobars analyzed have been developed. PMID:25044850
Hyndman, D E
2013-01-01
Analog and Hybrid Computing focuses on the operations of analog and hybrid computers. The book first outlines the history of computing devices that influenced the creation of analog and digital computers. The types of problems to be solved on computers, computing systems, and digital computers are discussed. The text looks at the theory and operation of electronic analog computers, including linear and non-linear computing units and use of analog computers as operational amplifiers. The monograph examines the preparation of problems to be deciphered on computers. Flow diagrams, methods of ampl
Neutron-skin thickness from the study of the antianalog giant dipole resonance
Krasznahorkay, A; Csatlós, M; Algora, A; Gulyás, J; Timár, J; Paar, N; Vretenar, D; Boretzky, K; Heil, M; Litvinov, Yu A; Rossi, D; Scheidenberger, C; Simon, H; Weick, H; Bracco, A; Brambilla, S; Blasi, N; Camera, F; Giaz, A; Million, B; Pellegri, L; Riboldi, S; Wieland, O; Altstadt, S; Fonseca, M; Glorius, J; Göbel, K; Heftrich, T; Koloczek, A; Kräckmann, S; Langer, C; Plag, R; Pohl, M; Rastrepina, G; Reifarth, R; Schmidt, S; Sonnabend, K; Weigand, M; Harakeh, M N; Kalantar-Nayestanaki, N; Rigollet, C; Bagchi, S; Najafi, M A; Aumann, T; Atar, L; Heine, M; Holl, M; Movsesyan, A; Schrock, P; Volkov, V; Wamers, F; Fiori, E; Löher, B; Marganiec, J; Savaran, D; Johansson, H T; Fernández, P Diaz; Garg, U; Balabanski, D L
2012-01-01
The gamma-decay of the anti-analog of the giant dipole resonance (AGDR) has been measured to the isobaric analog state excited in the p(124Sn,n) reaction at a beam energy of 600 MeV/nucleon. The energy of the transition was also calculated with state-of-the-art self-consistent random-phase approximation (RPA) and turned out to be very sensitive to the neutron-skin thickness (\\DeltaR_(pn)). By comparing the theoretical results with the measured one, the \\DeltaR_(pn) value for 124Sn was deduced to be 0.18 \\pm 0.02 fm, which agrees well with the previous results. The energy of the AGDR measured previously for ^(208)Pb was also used to determine the \\DeltaR_(pn) for ^(208)Pb. In this way a very precise \\DeltaR_(pn) = 0.18 \\pm 0.02 neutron-skin thickness has been obtained for 208Pb. The present method offers new possibilities for measuring the neutron-skin thicknesses of very exotic isotopes.
Applications of resonance ionization spectroscopy to ultralow-level counting and mass spectroscopy
The ability to directly detect a daughter atom, using resonance ionization spectroscopy, in delayed time coincidence with the decay of a parent species promises to drastically reduce the background in low-level counting experiments. Resonance ionization can also be used as an ion source for a mass spectrometer system that is capable of discriminating between isobars
The Dynamical Structure of the Delta-Resonance and its Effect on Two- and Three-Nucleon Systems
Kortemeyer, G.; Pena, M. T.; Sauer, P. U.; Stadler, A.
1996-01-01
The pion-nucleon interaction in the P33 partial wave is assumed to proceed simultaneously through the excitation of the Delta-isobar and through a phenomenologically introduced non-resonant background potential. The introduction of the background potential allows a more realistic parameterization of the pion-nucleon-Delta vertex compared with the previously used one without background. It also modifies the propagation of the Delta-isobar in the nuclear medium and gives rise to novel effective...
Laura eSciacca
2012-02-01
Full Text Available Today, insulin analogs are used in millions of diabetic patients. Insulin analogs have been developed to achieve more physiological insulin replacement in terms of time course of the effect. Modifications in the amino acid sequence of the insulin molecule change the pharmacokinetics and pharmacodynamics of the analogs in respect to human insulin. However, these changes can also modify the molecular and biological effects of the analogs. The rapid-acting insulin analogs, lispro, aspart and glulisine, have a rapid onset and shorter duration of action. The long-acting insulin analogs glargine and detemir have a protracted duration of action and a relatively smooth serum concentration profile. Insulin and its analogs may function as growth factors and therefore have a theoretical potential to promote tumor proliferation. A major question is whether analogs have an increased mitogenic activity in respect to insulin. These ligands can promote cell proliferation through many mechanisms like the prolonged stimulation of the insulin receptor, stimulation of the IGF-1 receptor (IGF-1R, prevalent activation of the ERK rather than the AKT intracellular post-receptor pathways. Studies on in vitro models indicate that short-acting analogs elicit molecular and biological effects that are similar to those of insulin. In contrast, long-acting analogs behave differently. Although not all data are homogeneous, both glargine and detemir have been found to have a decreased binding to IR but an increased binding to IGF-1R, a prevalent activation of the ERK pathway, and an increased mitogenic effect in respect to insulin. Recent retrospective epidemiological clinical studies have suggested that treatment with long-acting analogs (specifically glargine may increase the relative risk for cancer. Results are controversial and methodologically weak. Therefore prospective clinical studies are needed to evaluate the possible tumor growth-promoting effects of these insulin
Holyoak, Keith J.; Thagard, P.
1997-01-01
We examine the use of analogy in human thinking from the perspective of a multiconstraint theory, which postulates three basic types of constraints: similarity, structure and purpose. The operation of these constraints is apparent in both laboratory experiments on analogy and in naturalistic settings, including politics, psychotherapy, and scientific research. We sketch how the multiconstraint theory can be implemented in detailed computational simulations of the analogical human mind.
Dobkin, Bob
2012-01-01
Analog circuit and system design today is more essential than ever before. With the growth of digital systems, wireless communications, complex industrial and automotive systems, designers are being challenged to develop sophisticated analog solutions. This comprehensive source book of circuit design solutions aids engineers with elegant and practical design techniques that focus on common analog challenges. The book's in-depth application examples provide insight into circuit design and application solutions that you can apply in today's demanding designs. <
Sarpeshkar, R
2014-03-28
We analyse the pros and cons of analog versus digital computation in living cells. Our analysis is based on fundamental laws of noise in gene and protein expression, which set limits on the energy, time, space, molecular count and part-count resources needed to compute at a given level of precision. We conclude that analog computation is significantly more efficient in its use of resources than deterministic digital computation even at relatively high levels of precision in the cell. Based on this analysis, we conclude that synthetic biology must use analog, collective analog, probabilistic and hybrid analog-digital computational approaches; otherwise, even relatively simple synthetic computations in cells such as addition will exceed energy and molecular-count budgets. We present schematics for efficiently representing analog DNA-protein computation in cells. Analog electronic flow in subthreshold transistors and analog molecular flux in chemical reactions obey Boltzmann exponential laws of thermodynamics and are described by astoundingly similar logarithmic electrochemical potentials. Therefore, cytomorphic circuits can help to map circuit designs between electronic and biochemical domains. We review recent work that uses positive-feedback linearization circuits to architect wide-dynamic-range logarithmic analog computation in Escherichia coli using three transcription factors, nearly two orders of magnitude more efficient in parts than prior digital implementations. PMID:24567476
Revalidation of the isobaric multiplet mass equation for the $A=20$ quintet
Glassman, B E; Wrede, C; Allen, J; Bardayan, D W; Bennett, M B; Brown, B A; Chipps, K A; Febbraro, M; Fry, C; Hall, M R; Hall, O; Liddick, S N; O'Malley, P; Ong, W; Pain, S D; Schwartz, S B; Shidling, P; Sims, H; Thompson, P; Zhang, H
2015-01-01
An unexpected breakdown of the isobaric multiplet mass equation in the $A=20$, $T=2$ quintet was recently reported, presenting a challenge to modern theories of nuclear structure. In the present work, the excitation energy of the lowest $T = 2$ state in $^{20}$Na has been measured to be $6498.4 \\pm 0.2_{\\textrm{stat}} \\pm 0.4_{\\textrm{syst}}$ keV by using the superallowed $0^+ \\rightarrow 0^+$ beta decay of $^{20}$Mg to access it and an array of high-purity germanium detectors to detect its $\\gamma$-ray deexcitation. This value differs by 27 keV (1.9 standard deviations) from the recommended value of $6525 \\pm 14$ keV and is a factor of 28 more precise. The isobaric multiplet mass equation is shown to be revalidated when the new value is adopted.
Metric-tensor flexible-cell algorithm for isothermal-isobaric molecular dynamics simulations
Hernández, E
2001-01-01
An extended Hamiltonian approach to conduct isothermal-isobaric molecular dynamics simulations with full cell flexibility is presented. The components of the metric tensor are used as the fictitious degrees of freedom for the cell, thus avoiding the problem of spurious cell rotations and artificial symmetry breaking effects present in the original Parrinello-Rahman scheme. This is complemented by the Nose-Poincare approach for isothermal sampling. The combination of these two approaches leads to equations of motion that are Hamiltonian in structure, and which can therefore be solved numerically using recently developed powerful symplectic integrators. One such integrator, the generalised leap-frog, is employed to provide a numerical algorithm for integrating the isothermal-isobaric equations of motion obtained.
G. H. Bordbar
2001-12-01
Full Text Available One of the most interesting application of the many-body methods to the nuclear physics is the calculation of the properties of the nuclear matter, especially its binding energy. In this paper, we have studied the influence of Δ -isobar on the properties of the symmetrical nuclear matter using the lowest order constrained variational (LOCV method with the V28 potential. It is shown that the inclusion of Δ- isobar substantially affect the saturation properties of the symmetrical nuclear matter. We have shown that, at low (high densities, the saturation curve of nuclear matter is shifted downward (upward. This is due to the fact that the repulsive effect of the V28 potential increases by increasing density. It is seen that the equation of state of nuclear matter with the V28 potential is much harder than those with the A V14 potential.
Breakdown of the Isobaric Multiplet Mass Equation as An Effect of the Isospin-Symmetry Breaking
Dong, J M; Gu, J Z
2016-01-01
The breakdown of the quadratic form of isobaric multiplet mass equation (IMME), presents a long-standing challenge to the existing theoretical models. In particular, recent high-precision nuclear mass measurements have indicated a dramatic failure of the IMME for several isobaric multiplets. We propose a new mechanism that the isospin-projection $T_z$ dependence of the 1st-order symmetry energy coefficient (SEC) drives a significant breakdown of the IMME, where the 1st-order SEC is primarily induced by the isospin-symmetry breaking (ISB) of strong nuclear force. Completely different from the existing knowledge, the deviation from the IMME cannot be measured simply by the high-order terms such as cubic term $dT_{z}^3$.
Quantitation of protein post-translational modifications using isobaric tandem mass tags.
Liang, Hui-Chung; Lahert, Emma; Pike, Ian; Ward, Malcolm
2015-01-01
Post-translational modifications (PTMs) of proteins are known to modulate many cellular processes and their qualitative and quantitative evaluation is fundamental for understanding the mechanisms of biological events. Over the past decade, improvements in sample preparation techniques and enrichment strategies, the development of quantitative labeling strategies, the launch of a new generation of mass spectrometers and the creation of bioinformatics tools for the interrogation of ever larger datasets has established MS-based quantitative proteomics as a powerful workflow for global proteomics, PTM analysis and the elucidation of key biological mechanisms. With the advantage of their multiplexing capacity and the flexibility of an ever-growing family of different peptide-reactive groups, isobaric tandem mass tags facilitate quantitative proteomics and PTM experiments and enable higher sample throughput. In this review, we focus on the technical concept and utility of the isobaric tandem mass tag labeling approach to PTM analysis, including phosphorylation, glycosylation and S-nitrosylation. PMID:25697195
Isobaric Heat Capacity, Isothermal Compressibility and Fluctuational Properties of 1-Bromoalkanes
Korotkovskii, V. I.; Ryshkova, O. S.; Neruchev, Yu. A.; Goncharov, A. L.; Postnikov, E. B.
2016-06-01
We present results of the experimental measurements of the isobaric heat capacity for 1-bromohexane, 1-bromoheptane, 1-bromooctane, 1-bromononane, 1-bromodecane, 1-bromoundecane, 1-bromododecane and 1-bromotetradecane at normal pressure and the speed of sound and the density for 1-bromotetradecane within the temperature range 298.15-423.15 K. These data on the isobaric heat capacity and the literature-based reference data for the density and the speed of sound were used to calculate the isothermal compressibility and the inverse reduced fluctuations. Based on the comparison of the results for pure n-alkanes and α ,ω -dibromoalkanes, we discuss the influence of bromine atom on the volume fluctuations.
Isobaric heat capacity, isothermal compressibility and fluctuational properties of 1-bromoalkanes
Korotkovskii, V I; Neruchev, Yu A; Goncharov, A L; Postnikov, E B
2016-01-01
We present results of the experimental measurements of the isobaric heat capacity for 1-bromohexane, 1-bromoheptane, 1-bromooctane, 1-bromononane, 1-bromodecane, 1-bromoundecane, 1-bromododecane and 1-bromo-tetradecane at normal pressure and the speed of sound and the density for 1-bromotetradecane within the temperature range 298.15--423.15~K. These data on the isobaric heat capacity and the literature-based reference data for the density and the speed of sound were used to calculate the isothermal compressibility and the inverse reduced fluctuations. Based on the comparison of the results for pure n-alkanes and $\\alpha,\\omega$-dibromoalkanes, we discuss the influence of bromine atom on the volume fluctuations.
Resonance ionization mass spectrometry for isotopic abundance measurements
Miller, C. M.
1986-01-01
Resonance ionization mass spectrometry (RIMS) is a relatively new laser-based technique for the determination of isotopic abundances. The resonance ionization process depends upon the stepwise absorption of photons from the laser, promoting atoms of the element of interest through progressively higher electronic states until an ion is formed. Sensitivity arises from the efficiency of the resonant absorption process when coupled with the power available from commercial laser sources. Selectivity derives naturally from the distinct electronic structure of different elements. This isobaric discrimination has provided the major impetus for development of the technique. Resonance ionization mass spectrometry was used for analysis of the isotopic abundances of the rare earth lutetium. Isobaric interferences from ytterbium severely effect the ability to measure small amounts of the neutron-deficient Lu isotopes by conventional mass spectrometric techniques. Resonance ionization for lutetium is performed using a continuous-wave laser operating at 452 nm, through a sequential two-photon process, with one photon exciting the intermediate resonance and the second photon causing ionization. Ion yields for microgram-sized quantities of lutetium lie between 10(6) and 10(7) ions per second, at overall ionization efficiencies approaching 10(-4). Discrimination factors against ytterbium greater than 10(6) have been measured. Resonance ionization for technetium is also being explored, again in response to an isobaric interference, molybdenum. Because of the relatively high ionization potential for Tc, three-photon, two-color RIMS processes are being developed.
Preobrazhenskii, M. P.; Rudakov, O. B.
2016-01-01
A regression model for calculating the boiling point isobars of tetrachloromethane-organic solvent binary homogeneous systems is proposed. The parameters of the model proposed were calculated for a series of solutions. The correlation between the nonadditivity parameter of the regression model and the hydrophobicity criterion of the organic solvent is established. The parameter value of the proposed model is shown to allow prediction of the potential formation of azeotropic mixtures of solvents with tetrachloromethane.
Fridén, Mikael E; Sjöberg, Per J. R.
2014-01-01
Flavonoids are a class of secondary plant metabolites existing in great variety in nature. Due to this variety, identification can be difficult, especially as overlapping compounds in both chromatographic separations and mass spectrometric detection are common. Methods for distinguishing isobaric flavonoids using MS2 and MS3 have been developed. Chromatographic separation of various plant extracts was done with RP-HPLC and detected with positive ESI-MS operated in information-dependent acquis...
Transverse electron scattering response function of $^3$He with $\\Delta$-isobar degrees of freedom
Yuan, Luping; Efros, Victor D.; Leidemann, Winfried; Tomusiak, Edward L.
2010-01-01
A calculation of the $^3$He transverse $(e,e')$ inclusive response function, $R_T$, which includes $\\Delta$ degrees of freedom is performed using the Lorentz integral transform method. The resulting coupled equations are treated in impulse approximation, where the $NNN$ and $NN\\Delta$ channels are solved separately. As NN and NNN potentials we use the Argonne V18 and UrbanaIX models respectively. Electromagnetic currents include the $\\Delta$-isobar currents, one-body N-currents with relativis...
Delta-isobar relativistic meson exchange currents in quasielastic electron scattering
Amaro, J. E.; Barbaro, M. B.; Caballero, J. A.; Donnelly, T. W.; Molinari, A.
2003-01-01
We study the role of the $\\Delta$-isobar current on the response functions for high energy inclusive quasielastic electron scattering from nuclei. We consider a general Lagrangian which is compatible with contact invariance and perform a fully relativistic calculation in first-order perturbation theory for one-particle emission. The dependence of the responses upon off-shell parametrizations is analyzed and found to be mild. A discussion of scaling behaviour and a comparison with various non-...
Delta(1232) isobar excitations in nuclear many-body systems from varios NN interactions.
Frick, T; Kaiser, S.; Müther, Herbert; Polls Martí, Artur
2001-01-01
$\\Delta$ isobar components in the nuclear many-body wave function are investigated for the deuteron, light nuclei (${}^{16}O$) and infinite nuclear matter within the framework of the coupled-cluster theory. The predictions derived for various realistic models of the baryon-baryon interaction are compared to each other. These include local ($V28$) and non-local meson exchange potentials (Bonn$_{2000}$) but also a model recently derived by the Salamanca group accounting for quark degrees of fre...
Study of $\\Delta(1232)$ isobar electroproduction at VEPP-2M $e^+e^-$ collider
Achasov, M. N.; Bozhenok, A. V.; Bukin, A.D.; Bukin, D. A.; Burdin, S. V.; Dimova, T. V.; Dolinsky, S. I.; Druzhinin, V. P.; Dubrovin, M. S.; Gaponenko, I. A.; Golubev, V. B.; Ivanchenko, V. N.(Budker Institute of Nuclear Physics SB RAS, 630090, Novosibirsk, Russia); Korol, A.A.; Koshuba, S. V.; Lysenko, A. P.
1998-01-01
Results from the Spherical Nonmagnetic Detector (SND) on $\\Delta (1232)$ isobar electroproduction in the collisions of beam electrons (positrons) and residual gas nuclei in the VEPP-2M $e^+e^-$ collider are presented. On the basis of the obtained data the expected counting rate of this process in future high luminosity $e^+e^-$ colliders (~$\\phi$-, $c$-$\\tau$- and $b$-factories) was estimated.
Highlights: • The densities of cyclohexane and its mixtures with 1-butanol were measured. • The excess molar volumes were calculated and correlated. • The viscosities were measured at atmospheric pressure. • The isobaric heat capacities were measured at p = (0.1 to 25) MPa at T = (293.15 and 313.15) K. • A positive deviation from the ideal behavior is observed. - Abstract: The cyclohexane and the system of 1-butanol + cyclohexane have been characterized using densities, viscosities and isobaric heat capacities measurements. For that, the densities were measured in a high-pressure vibrating tube densimeter at five temperatures from (293.15 to 333.15) K and pressures up to 100 MPa. The measurements were correlated with the empirical Tamman–Tait equation. Moreover, the isobaric heat capacities of the binary system were measured in a high-pressure automated flow calorimeter at T = (293.15 and 313.15) K and pressures up to 25 MPa for pure cyclohexane and in admixture with 1-butanol. The excess molar heat capacities were assessed for the mixture and a positive deviation from the ideality was obtained, except for a small part in the region rich in alkanol. The viscosity measurements were carried out, at the calorimeter conditions, for correcting the experimental values of isobaric heat capacities due to friction along the tube. The viscosity was measured at atmospheric pressure in a Stabinger Anton Paar SVM 3000 viscometer in the temperature range of (293.15 to 333.15) K for cyclohexane and the mixtures. At high pressure, the viscosities were estimated using Lucas method
Analysis of Meson Exchange and Isobar Currents in (e,e'p) Reactions from O-16
Amaro, J. E.; Lallena, A. M.; Caballero, J. A.
1999-01-01
An analysis of the effects of meson exchange and isobar currents in exclusive (e,e'p) processes from O-16 under quasi-free kinematics is presented. A model that has probed its feasibility for inclusive quasi-elastic (e,e') processes is considered. Sensitivity to final state interactions between the outgoing proton and the residual nucleus is discussed by comparing the results obtained with phenomenological optical potentials and a continuum nuclear shell-model calculation. The contribution of...
The role of the Delta isobar in chiral perturbation theory and hedgehog soliton models
Cohen, Thomas D.; Broniowski, Wojciech
1992-01-01
Hedgehog model predictions for the leading nonanalytic behavior (in $m^{2}_{\\pi }$) of certain observables are shown to agree with the predictions of chiral perturbation theory up to an overall factor which depends on the operator. This factor can be understood in terms of contributions of the $\\Delta$ isobar in chiral loops. These physically motivated contributions are analyzed in an expansion in which both $m_{\\pi}$ and $M_{\\Delta}-M_N$ are taken as small parameters, and are shown to yield ...
Analysis of $\\Delta^{+}(1232)$ Isobar Observables, with Improved Quark Distribution Amplitudes
Stefanis, N. G.; Bergmann, M.
1992-01-01
A model distribution amplitude for the $\\Delta^{+}(1232)$ isobar is proposed, derived on the basis of the QCD sum-rule calculations of Farrar et al. combined with those of Carlson and Poor. The transition form factor $\\gamma p\\Delta^{+}$ is calculated modeling the proton by selected distribution amplitudes. Furthermore, predictions are made for some exclusive charmonium decays into $\\Delta\\bar{\\Delta}$. The obtained results are compared with other theoretical models and with the available data.
Isobar of an ideal Bose gas within the grand canonical ensemble
Jeon, Imtak; Kim, Sang-Woo; Park, Jeong-Hyuck
2011-01-01
We investigate the isobar of an ideal Bose gas confined in a cubic box within the grand canonical ensemble, for a large yet finite number of particles, N. After solving the equation of the spinodal curve, we derive precise formulae for the supercooling and the superheating temperatures which reveal an N^{-1/3} or N^{-1/4} power correction to the known Bose-Einstein condensation temperature in the thermodynamic limit. Numerical computations confirm the accuracy of our analytical approximation,...
Nuclear matter properties from local chiral interactions with $\\Delta$ isobar intermediate states
Logoteta, Domenico; Kievsky, Alejandro
2016-01-01
Using two-nucleon and three-nucleon interactions derived in the framework of chiral perturbation theory (ChPT) with and without the explicit $\\Delta$ isobar contributions, we calculate the energy per particle of symmetric nuclear matter and pure neutron matter in the framework of the microscopic Brueckner-Hartree-Fock approach. In particular, we present for the first time nuclear matter calculations using the new fully local in coordinate-space two-nucleon interaction at the next-to-next-to-next-to-leading-order (N3LO) of ChPT with $\\Delta$ isobar intermediate states (N3LO$\\Delta$) recently developed by Piarulli et al. [arXiv:1606:06335]. We find that using this N3LO$\\Delta$ potential, supplemented with a local N2LO three-nucleon interaction with explicit $\\Delta$ isobar degrees of freedom, it is possible to obtain a satisfactory saturation point of symmetric nuclear matter. For this combination of two- and three-nucleon interactions we also calculate the nuclear symmetry energy and we compare our results wit...
Baser, Mustafa
2007-01-01
Students have difficulties in physics because of the abstract nature of concepts and principles. One of the effective methods for overcoming students' difficulties is the use of analogies to visualize abstract concepts to promote conceptual understanding. According to Iding, analogies are consistent with the tenets of constructivist learning…
Wessendorf, Kurt O.; Kemper, Dale A.
2003-06-03
A very low power analog pulse processing system implemented as an ASIC useful for processing signals from radiation detectors, among other things. The system incorporates the functions of a charge sensitive amplifier, a shaping amplifier, a peak sample and hold circuit, and, optionally, an analog to digital converter and associated drivers.
Fermion resonance in quantum field theory
Gonchar, M. O.; Kaloshin, A. E.; Lomov, V. P.
2006-01-01
We derive accurately the fermion resonance propagator by means of Dyson summation of the self-energy contribution. It turns out that the relativistic fermion resonance differs essentially from its boson analog.
Malav, O P; Talukder, S; Gokulakrishnan, P; Chand, S
2015-01-01
The health-conscious consumers are in search of nutritious and convenient food item which can be best suited in their busy life. The vegetarianism is the key for the search of such food which resembles the meat in respect of nutrition and sensory characters, but not of animal origin and contains vegetable or its modified form, this is the point when meat analog evolved out and gets shape. The consumers gets full satisfaction by consumption of meat analog due to its typical meaty texture, appearance and the flavor which are being imparted during the skilled production of meat analog. The supplement of protein in vegetarian diet through meat alike food can be fulfilled by incorporating protein-rich vegetative food grade materials in meat analog and by adopting proper technological process which can promote the proper fabrication of meat analog with acceptable meat like texture, appearance, flavor, etc. The easily available vegetables, cereals, and pulses in India have great advantages and prospects to be used in food products and it can improve the nutritional and functional characters of the food items. The various form and functional characters of food items are available world over and attracts the meat technologists and the food processors to bring some innovativeness in meat analog and its presentation and marketability so that the acceptability of meat analog can be overgrown by the consumers. PMID:24915320
Troubleshooting analog circuits
Pease, Robert A
1991-01-01
Troubleshooting Analog Circuits is a guidebook for solving product or process related problems in analog circuits. The book also provides advice in selecting equipment, preventing problems, and general tips. The coverage of the book includes the philosophy of troubleshooting; the modes of failure of various components; and preventive measures. The text also deals with the active components of analog circuits, including diodes and rectifiers, optically coupled devices, solar cells, and batteries. The book will be of great use to both students and practitioners of electronics engineering. Other
Challenges in Analogical Reasoning
Lin, Shih-Yin
2016-01-01
Learning physics requires understanding the applicability of fundamental principles in a variety of contexts that share deep features. One way to help students learn physics is via analogical reasoning. Students can be taught to make an analogy between situations that are more familiar or easier to understand and another situation where the same physics principle is involved but that is more difficult to handle. Here, we examine introductory physics students' ability to use analogies in solving problems involving Newton's second law. Students enrolled in an algebra-based introductory physics course were given a solved problem involving tension in a rope and were then asked to solve another problem for which the physics is very similar but involved a frictional force. They were asked to point out the similarities between the two problems and then use the analogy to solve the friction problem.
TV Analog Station Transmitters
Department of Homeland Security — This file is an extract from the Consolidated Database System (CDBS) licensed by the Media Bureau. It consists of Analog Television Stations (see Rule Part47 CFR...
Hickman, Ian
2013-01-01
Analog Circuits Cookbook presents articles about advanced circuit techniques, components and concepts, useful IC for analog signal processing in the audio range, direct digital synthesis, and ingenious video op-amp. The book also includes articles about amplitude measurements on RF signals, linear optical imager, power supplies and devices, and RF circuits and techniques. Professionals and students of electrical engineering will find the book informative and useful.
Synthesis of Paclitaxel Analogs
Xu, Zhibing
2010-01-01
Paclitaxel is one of the most successful anti-cancer drugs, particularly in the treatment of breast cancer and ovarian cancer. For the investigation of the interaction between paclitaxel and MD-2 protein, and development of new antagonists for lipopolysaccharide, several C10 A-nor-paclitaxel analogs have been synthesized and their biological activities have been evaluated. In order to reduce the myelosuppression effect of the paclitaxel, several C3â ² and C4 paclitaxel analogs have been synth...
Electrical Circuits and Water Analogies
Smith, Frederick A.; Wilson, Jerry D.
1974-01-01
Briefly describes water analogies for electrical circuits and presents plans for the construction of apparatus to demonstrate these analogies. Demonstrations include series circuits, parallel circuits, and capacitors. (GS)
Determination of isobar composition and yields of 239Pu fission-products by thermal neutrons
On the research nuclear reactor WWR-SM of INP Uz AS by means of mass-spectrometer the heavy fission-products of 239Pu nuclei induced by thermal neutrons are measured in ranges of mass Ai = 125 -157, kinetic energies Ek = 45 - 87 MeV and effective ionic charges z* = 18 - 30. 102 isobar nuclei in composition of the measured fission-products, also the partial yields of the each element giving the contribution to formation of a total yield of heavy fission-product with mass Ai are defined. (authors)
Three-pion exchange nucleon-nucleon potentials with virtual $\\Delta$-isobar excitation
Kaiser, N
2015-01-01
The nucleon-nucleon interaction arising from the exchange of three pions and the excitation of $\\Delta(1232)$-isobars in intermediate states is studied. Approximating the $\\Delta$-propagator by the inverse $\\Delta$N mass-splitting, analytical expressions are derived for the spectral-functions of the isoscalar and isovector central, spin-spin and tensor NN-potentials in momentum-space. A trans- lation of the spectral-functions into coordinate-space potentials reveals that the main effect of these specific exchange and excitation mechanisms is a repulsive isoscalar central NN-potential.
Photoproduction of the $\\pi N$ pair on nuclei and isobar configurations
Glavanakov, I. V.; Tabachenko, A. N.
2012-01-01
A model of $\\pi N$ pair photoproduction on nuclei at high momentum transfer is presented. The $A(\\gamma,\\pi N)B$ reaction amplitude is obtained by means of an extended impulse approximation, according to which the nuclear wavefunction includes delta-isobar components in addition to nucleon components. A one-particle transition operator is defined in terms of the two-body $\\gamma N\\to\\pi N$ and $\\gamma \\Delta\\to\\pi N$ photoproduction amplitudes. Direct and exchange mechanisms of the nuclear ph...
The Nuclear Response in Delta-Isobar Region in the ($^3\\!$He,t) Reaction
Dmitriev, V. F.
1992-01-01
The excitation of a $\\Delta$-isobar in a finite nucleus in charge--exchange ($^3\\!$He,t) reaction is discussed in terms of a nuclear response function. The medium effects modifying a $\\Delta$- and a pion propagation were considered for a finite size nucleus. The Glauber approach has been used for distortion of a $^3\\!$He and a triton in the initial and the final states. The effects determining the peak positions and its width are discussed. Large displacement width for the $\\Delta$ - h excita...
An Isobar Model of e+ e- --> pi+ pi- pi0 pi0
McGowan, John F.
1995-01-01
In this paper, several calculations of the matrix elements for processes that may contribute to e+ e- --> pi+ pi- pi0 pi0 using the isobar model and the Lorentz invariant amplitude method are presented. The formulas may be used to determine the electromagnetic form factors of the rho meson if e+ e- --> rho+ rho- contributes to e+ e- --> pi+ pi- pi0 pi0 The electromagnetic form factors of the rho meson are predicted by QCD calculations. The formulas in this paper may be used to study the a_1 m...
Effects of Δ-isobar degrees of freedom on low-energy electroweak transitions in few-body nuclei
Variational wave functions with Δ-isobar components are used to study trinucleon magnetic moments, the Gamow-Teller matrix element of tritium β decay, thermal neutron radiative capture on 3He, and low-energy proton weak capture on 3He. The Δ-isobar components are generated by transition correlation operators acting on realistic nuclear wave functions. These correlations are obtained from a fit to exact two-body ground-state and low-energy scattering solutions for the Argonne v28 and v28Q interaction models, which include Δ-isobar degrees of freedom. Contributions of Δ isobars to electroweak current operators appear at the one-body level in this formalism. Their effect on low-energy electroweak transitions is significantly smaller than that obtained in perturbation theory analyses, where Δ-isobar effects are commonly subsumed into effective two-body current operators. The resulting theoretical cross section for thermal neutron radiative capture on 3He is ∼86 μb, compared to an experimental value of 55±3 μb; the astrophysical S factor for proton weak capture on 3He is predicted to be in the range (1.4--3.2)x10-23 MeV b
Digital and analog communication systems
Shanmugam, K. S.
1979-01-01
The book presents an introductory treatment of digital and analog communication systems with emphasis on digital systems. Attention is given to the following topics: systems and signal analysis, random signal theory, information and channel capacity, baseband data transmission, analog signal transmission, noise in analog communication systems, digital carrier modulation schemes, error control coding, and the digital transmission of analog signals.
Analogical Reasoning in Geometry Education
Magdas, Ioana
2015-01-01
The analogical reasoning isn't used only in mathematics but also in everyday life. In this article we approach the analogical reasoning in Geometry Education. The novelty of this article is a classification of geometrical analogies by reasoning type and their exemplification. Our classification includes: analogies for understanding and setting a…
Electrical analogous in viscoelasticity
Ala, Guido; Di Paola, Mario; Francomano, Elisa; Li, Yan; Pinnola, Francesco P.
2014-07-01
In this paper, electrical analogous models of fractional hereditary materials are introduced. Based on recent works by the authors, mechanical models of materials viscoelasticity behavior are firstly approached by using fractional mathematical operators. Viscoelastic models have elastic and viscous components which are obtained by combining springs and dashpots. Various arrangements of these elements can be used, and all of these viscoelastic models can be equivalently modeled as electrical circuits, where the spring and dashpot are analogous to the capacitance and resistance, respectively. The proposed models are validated by using modal analysis. Moreover, a comparison with numerical experiments based on finite difference time domain method shows that, for long time simulations, the correct time behavior can be obtained only with modal analysis. The use of electrical analogous in viscoelasticity can better reveal the real behavior of fractional hereditary materials.
McGrath, M; Siepmann, J I; Kuo, I W; Mundy, C J; VandeVondele, J; Hutter, J; Mohamed, F; Krack, M
2004-12-02
A series of first principles Monte Carlo simulations in the isobaric-isothermal ensemble were carried out for liquid water at ambient conditions (T = 298 K and p = 1 atm). The Becke-Lee-Yang-Parr (BLYP) exchange and correlation energy functionals and norm-conserving Goedecker-Teter-Hutter (GTH) pseudopotentials were employed with the CP2K simulation package to examine systems consisting of 64 water molecules. The fluctuations in the system volume encountered in simulations in the isobaric-isothermal ensemble requires a reconsideration of the suitability of the typical charge density cutoff and the regular grid generation method previously used for the computation of the electrostatic energy in first principles simulations in the microcanonical or canonical ensembles. In particular, it is noted that a much higher cutoff is needed and that the most computationally efficient method of creating grids can result in poor simulations. Analysis of the simulation trajectories using a very large charge density cutoff at 1200 Ry and four different grid generation methods point to a substantially underestimated liquid density of about 0.85 g/cm{sup 3} resulting in a somewhat understructured liquid (with a value of about 2.7 for the height of the first peak in the oxygen/oxygen radial distribution function) for BLYP-GTH water at ambient conditions.
Decay studies and mass measurements on isobarically pure neutron-rich Hg and Tl isotopes
Schweikhard, L C; Savreux, R P; Hager, U D K; Beck, D; Blaum, K
2007-01-01
We propose to perform mass measurements followed by $\\beta$- and $\\gamma$-decay studies on isobarically pure beams of neutron-rich Hg and Tl isotopes, which are very poorly known due to a large contamination at ISOL-facilities with surface-ionised francium. The aim is to study the binding energies of mother Hg and Tl nuclides, as well as the energies, spins and parities of the excited and ground states in the daughter Tl and Pb isotopes. The proposed studies will address a new subsection of the nuclear chart, with Z 126, where only 9 nuclides have been observed so far. Our studies will provide valuable input for mass models and shell-model calculations: they will probe the proton hole-neutron interaction and will allow to refine the matrix elements for the two-body residual interaction. Furthermore, they also give prospects for discovering new isomeric states or even new isotopes, for which the half-lives are predicted in the minute- and second-range.\\\\ To reach the isobaric purity, the experiments will be p...
The MR-TOF-MS isobar separator for the TITAN facility at TRIUMF
Jesch, Christian; Dickel, Timo, E-mail: t.dickel@gsi.de; Plaß, Wolfgang R. [Justus-Liebig-University (Germany); Short, Devin [Simon Fraser University (Canada); Ayet San Andres, Samuel [Justus-Liebig-University (Germany); Dilling, Jens [TRIUMF (Canada); Geissel, Hans; Greiner, Florian; Lang, Johannes [Justus-Liebig-University (Germany); Leach, Kyle G. [Simon Fraser University (Canada); Lippert, Wayne; Scheidenberger, Christoph [Justus-Liebig-University (Germany); Yavor, Mikhail I. [Institute for Analytical Instrumentation, Russian Academy of Science (Russian Federation)
2015-11-15
At TRIUMF’s Ion Trap for Atomic and Nuclear Science (TITAN) a multiple-reflection time-of-flight mass spectrometer (MR-TOF-MS) will extend TITAN’s capabilities and facilitate mass measurements and in-trap decay spectroscopy of exotic nuclei that so far have not been possible due to strong isobaric contamination. This MR-TOF-MS will also enable mass measurements of very short-lived nuclides (half-life > 1 ms) that are produced in very low quantities (a few detected ions overall). In order to allow the installation of an MR-TOF-MS in the restricted space on the platform, on which the TITAN facility is located, novel mass spectrometric methods have been developed. Transport, cooling and distribution of the ions inside the device is done using a buffer gas-filled RFQ-based ion beam switchyard. Mass selection is achieved using a dynamic retrapping technique after time-of-flight analysis in an electrostatic isochronous reflector system. Only due to the combination of these novel methods the realization of an MR-TOF-MS based isobar separator at TITAN has become possible. The device has been built, commissioned off-line and is currently under installation at TITAN.
The MR-TOF-MS isobar separator for the TITAN facility at TRIUMF
At TRIUMF’s Ion Trap for Atomic and Nuclear Science (TITAN) a multiple-reflection time-of-flight mass spectrometer (MR-TOF-MS) will extend TITAN’s capabilities and facilitate mass measurements and in-trap decay spectroscopy of exotic nuclei that so far have not been possible due to strong isobaric contamination. This MR-TOF-MS will also enable mass measurements of very short-lived nuclides (half-life > 1 ms) that are produced in very low quantities (a few detected ions overall). In order to allow the installation of an MR-TOF-MS in the restricted space on the platform, on which the TITAN facility is located, novel mass spectrometric methods have been developed. Transport, cooling and distribution of the ions inside the device is done using a buffer gas-filled RFQ-based ion beam switchyard. Mass selection is achieved using a dynamic retrapping technique after time-of-flight analysis in an electrostatic isochronous reflector system. Only due to the combination of these novel methods the realization of an MR-TOF-MS based isobar separator at TITAN has become possible. The device has been built, commissioned off-line and is currently under installation at TITAN
RFQ Reaction Cells for Isobar Separation in AMS: Evolution and Current Status
In the mass spectrometry of cations, such as Inductively Coupled Plasma-, Atmospheric Pressure Chemical Ionization-, or Electro-spray-Mass Spectrometry, ion-gas reactions have provided a powerful tool for the elimination of isobars and other unwanted species. The energies usually used in Accelerator Mass Spectrometry (AMS), even at the injection stage, and the fragility of the anions themselves have presented considerable challenges to using this technique for AMS. Nevertheless, work on a demonstration radiofrequency quadrupole (RFQ) system at the IsoTrace Laboratory in which the anions are decelerated to energies of several eV before entering the reaction cell has shown isobar suppression factors ranging between 10-4 and 10-7, while, in most cases, retaining reasonable transmission of the analyte anion. This seminar will begin with a review of the influences and ideas leading to the design and building of this prototype and a description of its functionality. A summary of the results obtained using this system, including recent ones which open up new applications for AMS, will follow, along with an outline of the design considerations for a pre-commercial system which is being installed on a second injection line at the Lalonde Laboratory. (author)
Breakdown of the Isobaric Multiplet Mass Equation for the A = 20 and 21 Multiplets
Gallant, A T; Andreoiu, C; Bader, A; Chaudhuri, A; Chowdhury, U; Grossheim, A; Klawitter, R; Kwiatkowski, A A; Leach, K G; Lennarz, A; Macdonald, T D; Schultz, B E; Lassen, J; Heggen, H; Raeder, S; Teigelhöfer, A; Brown, B A; Magilligan, A; Holt, J D; Menéndez, J; Simonis, J; Schwenk, A; Dilling, J
2014-01-01
Using the Penning trap mass spectrometer TITAN, we performed the first direct mass measurements of 20,21Mg, isotopes that are the most proton-rich members of the A = 20 and A = 21 isospin multiplets. These measurements were possible through the use of a unique ion-guide laser ion source, a development that suppressed isobaric contamination by six orders of magnitude. Compared to the latest atomic mass evaluation, we find that the mass of 21Mg is in good agreement but that the mass of 20Mg deviates by 3{\\sigma}. These measurements reduce the uncertainties in the masses of 20,21Mg by 15 and 22 times, respectively, resulting in a significant departure from the expected behavior of the isobaric multiplet mass equation in both the A = 20 and A = 21 multiplets. This presents a challenge to shell model calculations using either the isospin non-conserving USDA/B Hamiltonians or isospin non-conserving interactions based on chiral two- and three-nucleon forces.
Evaluated experimental isobaric analogue states from T=1/2 to T=3 and associated IMME coefficients
MacCormick, M., E-mail: maccorm@ipno.in2p3.fr [Institut de Physique Nucléaire CNRS/IN2P3 and Université Paris-Sud, Orsay (France); Audi, G. [Centre de Sciences Nucléaires et de Sciences de la Matière CSNSM, CNRS/IN2P3 and Université Paris-Sud, Orsay (France)
2014-05-15
Isobaric multiplets can be used to provide reliable mass predictions through the Isobaric Multiplet Mass Equation (IMME). Isobaric Analogue States (IAS) for isospin multiplets from T=1/2 to 3 have been studied within the 2012 Atomic Mass Evaluation (AME2012). Each IAS established from published experimental reaction data has been expressed in the form of a primary reaction Q-value and, when necessary, has been recalibrated. The evaluated IAS masses are provided here along with the associated IMME coefficients. Quadratic and higher order forms of the IMME have been considered, and global trends have been extracted. Particular nuclides requiring experimental investigation have been identified and discussed. This dataset is the most precise and extensive set of evaluated IAS to date.
Zak, M.
1998-01-01
Quantum analog computing is based upon similarity between mathematical formalism of quantum mechanics and phenomena to be computed. It exploits a dynamical convergence of several competing phenomena to an attractor which can represent an externum of a function, an image, a solution to a system of ODE, or a stochastic process.
Štěpán, Pavel
Cluj : Mega, 2013 - (Felecan, O.), s. 379-383 ISBN 978-606-543-343-4. [Name and Naming /2./ Onomastics in Contemporary Public Space. Baia Mare (RO), 09.05.2013-11.05.2013] R&D Projects: GA ČR GPP406/12/P600 Institutional support: RVO:68378092 Keywords : onomastics * toponyms * analogy Subject RIV: AI - Linguistics
Polymorphs of 1,1-diamino-2,2-dinitroethene (FOX-7): Isothermal compression versus isobaric heating
Dreger, Z. A.; Tao, Y.; Gupta, Y. M.
2013-10-01
Raman spectroscopy was used to examine polymorphic changes in 1,1-diamino-2,2-dinitroethene (FOX-7) single crystals under: isothermal compression to 15 GPa and isobaric heating to 500 K. Changes in the Raman spectra were observed at ˜2.0 and ˜4.5 GPa, and at ˜390 K and ˜450 K. These onsets are in general accord with previously reported onsets from IR measurements under isothermal compression and from X-ray diffraction measurements under isobaric heating, respectively. In contrast to recent suggestions, we show that the high pressure polymorphs have different vibrational structures, and likely different crystal structures, than the high temperature polymorphs.
PIPERADE: A Penning-trap isobar separator for the DESIR low-energy facility of SPIRAL2
Ascher P.
2014-03-01
Full Text Available A Penning-trap isobar separator is currently under construction at CENBG (Bordeaux, France and MPIK (Heidelberg, Germany for a future installation at the SPIRAL2/DESIR facility. This device aims at purifying the radioactive ion beams from undesired species, in order to deliver highly pure samples of exotic nuclei to the different set-ups which will be installed in the DESIR hall. The present manuscript describes the context and the motivations to build such a system, the targeted characteristics, and the studies to find an efficient purification method for large samples of isobaric species.
Resonances in subatomic physics
The Balmer-like mass formula was applied for systematic analysis of gross structure of all known hadronic resonances. The accuracy of the mass formula is surprisingly hugh. It is demonstrated that the dimension analysis, the principles of similitude and automodelity, the methods of analogy can put some bridge between the different branches of physics
Terrestrial Spaceflight Analogs: Antarctica
Crucian, Brian
2013-01-01
Alterations in immune cell distribution and function, circadian misalignment, stress and latent viral reactivation appear to persist during Antarctic winterover at Concordia Station. Some of these changes are similar to those observed in Astronauts, either during or immediately following spaceflight. Others are unique to the Concordia analog. Based on some initial immune data and environmental conditions, Concordia winterover may be an appropriate analog for some flight-associated immune system changes and mission stress effects. An ongoing smaller control study at Neumayer III will address the influence of the hypoxic variable. Changes were observed in the peripheral blood leukocyte distribution consistent with immune mobilization, and similar to those observed during spaceflight. Alterations in cytokine production profiles were observed during winterover that are distinct from those observed during spaceflight, but potentially consistent with those observed during persistent hypobaric hypoxia. The reactivation of latent herpesviruses was observed during overwinter/isolation, that is consistently associated with dysregulation in immune function.
GUAN Yong-Jing; RUAN Xiang-Dong; HE Ming; WANG Hui-Juan; LI Guo-Qiang; WU Shao-Yong; DONG Ke-Jun; LIN Min; JIANG Shan
2005-01-01
@@ A gas-filled time-of-flight (GF-TOF) detector has been built and developed to improve the ability of isobaric identification in accelerator mass spectrometry (AMS) measurements, and a time resolution (without gas filled)of better than 350ps is achieved. The GF-TOF detector is tested by means of measuring a standard AgCl(36Cl/Cl = 7.6 × 10-9g/g) sample with the 36Cl ion energy of 64, 49 and 33MeV, respectively. 36Cl and 36S particles were successfully separated in the TOF spectra output from the GF-TOF detector. The comparison between the gas-filled time-of-flight method and the △E - E method is described. Some results relative to the GF-TOF method are given as well.
Light-front representation of chiral dynamics with Delta isobar and large-N_c relations
Granados, C
2016-01-01
Transverse densities describe the spatial distribution of electromagnetic current in the nucleon at fixed light-front time. At peripheral distances b = O(M_pi^{-1}) the densities are governed by chiral dynamics and can be calculated model-independently using chiral effective field theory (EFT). Recent work has shown that the EFT results can be represented in first-quantized form, as overlap integrals of chiral light-front wave functions describing the transition of the nucleon to soft-pion-nucleon intermediate states, resulting in a quantum-mechanical picture of the peripheral transverse densities. We now extend this representation to include intermediate states with Delta isobars and implement relations based on the large-N_c limit of QCD. We derive the wave function overlap formulas for the Delta contributions to the peripheral transverse densities by way of a three-dimensional reduction of relativistic chiral EFT expressions. Our procedure effectively maintains rotational invariance and avoids the ambiguit...
Two-proton decay of the isobaric analogue state of 31Ar
Mukha, I.; Axelsson, L.; Äystö, J.; Bergmann, U. C.; Borge, M. J. G.; Fraile, L. M.; Fynbo, H. O. U.; Honkanen, A.; Hornshøj, P.; Jading, Y.; Jonson, B.; Jokinen, A.; Martel, I.; Oinonen, M.; Nilsson, T.; Nyman, G.; Petersen, B.; Riisager, K.; Siiskonen, T.; Smedberg, M. H.; Tengblad, O.; Wenander, F.; Isolde Collaboration
1998-02-01
We have studied several two proton branches in the β-decay of 31Ar, the most intensive ones proceeding through the isobaric analogue state (IAS) in 31Cl. The energy and angular correlations of the two protons originating from the IAS have been measured. An indication of non-isotropic emission has been observed in the p+p+ 29P branch. The energy spectra of protons from the IAS 2p-branches seem to be continuous, which is difficult to explain by a sequential emission through a few intermediate levels in 30S. The model of non-sequential or democratic three-particle decay gives the best fit to the present data favoring the IAS spin-parity {5}/{2 +}.
Everett, Keith R.
2005-01-01
The purpose of this project is to investigate the feasibility of and methodology for the development of a set of environmental analogs of operational Undersea Warfare (USW) areas within fleet training areas. It is primarily a discussion of the identification of parameters that characterize the tactical USW environment, prioritization of these parameters, identification of existing databases that contain these parameters and an outline of the processes required to extract the desired data fro...
Analogy, Explanation, and Proof
John eHummel
2014-11-01
Full Text Available People are habitual explanation generators. At its most mundane, our propensity to explain allows us to infer that we should not drink milk that smells sour; at the other extreme, it allows us to establish facts (e.g., theorems in mathematical logic whose truth was not even known prior to the existence of the explanation (proof. What do the cognitive operations underlying the (inductive inference that the milk is sour have in common with the (deductive proof that, say, the square root of two is irrational? Our ability to generate explanations bears striking similarities to our ability to make analogies. Both reflect a capacity to generate inferences and generalizations that go beyond the featural similarities between a novel problem and familiar problems in terms of which the novel problem may be understood. However, a notable difference between analogy-making and explanation-generation is that the former is a process in which a single source situation is used to reason about a single target, whereas the latter often requires the reasoner to integrate multiple sources of knowledge. This small-seeming difference poses a challenge to the task of marshaling our understanding of analogical reasoning in the service of understanding explanation. We describe a model of explanation, derived from a model of analogy, adapted to permit systematic violations of this one-to-one mapping constraint. Simulation results demonstrate that the resulting model can generate explanations for novel explananda and that, like the explanations generated by human reasoners, these explanations vary in their coherence.
Stojković, Nino
2006-01-01
In this paper the Asymmetric Digital Subscriber Line (ADSL) analog front end (AFE) designs are described and compared. AFE is the part of ADSL modems most responsible for quality signal transmission over phone wires. It can be divided into the transmitting path (TX) circuitry, the receiving path (RX) circuitry and the hybrid network and transformer. The operations and realizations of each functional block are presented. There are the D/A converter, the filter and the line driver in the TX pat...
Caloz, Christophe; Gupta, Shulabh; Zhang, Qingfeng; Nikfal, Babak
2013-01-01
Analog signal processing (ASP) is presented as a systematic approach to address future challenges in high speed and high frequency microwave applications. The general concept of ASP is explained with the help of examples emphasizing basic ASP effects, such as time spreading and compression, chirping and frequency discrimination. Phasers, which represent the core of ASP systems, are explained to be elements exhibiting a frequency-dependent group delay response, and hence a nonlinear phase resp...
Luís M. S. Loura
2012-01-01
Förster resonance energy transfer (FRET) is a powerful tool used for many problems in membrane biophysics, including characterization of the lateral distribution of lipid components and other species of interest. However, quantitative analysis of FRET data with a topological model requires adequate choices for the values of several input parameters, some of which are difficult to obtain experimentally in an independent manner. For this purpose, atomistic molecular dynamics (MD) simul...
Kipping, David M; Henze, Chris; Teachey, Alex; Isaacson, Howard T; Petigura, Erik A; Marcy, Geoffrey W; Buchhave, Lars A; Chen, Jingjing; Bryson, Steve T; Sandford, Emily
2016-01-01
Decadal-long radial velocity surveys have recently started to discover analogs to the most influential planet of our solar system, Jupiter. Detecting and characterizing these worlds is expected to shape our understanding of our uniqueness in the cosmos. Despite the great successes of recent transit surveys, Jupiter analogs represent a terra incognita, owing to the strong intrinsic bias of this method against long orbital periods. We here report on the first validated transiting Jupiter analog, Kepler-167e (KOI-490.02), discovered using Kepler archival photometry orbiting the K4-dwarf KIC-3239945. With a radius of $(0.91\\pm0.02)$ $R_{\\mathrm{Jup}}$, a low orbital eccentricity ($0.06_{-0.04}^{+0.10}$) and an equilibrium temperature of $(131\\pm3)$ K, Kepler-167e bears many of the basic hallmarks of Jupiter. Kepler-167e is accompanied by three Super-Earths on compact orbits, which we also validate, leaving a large cavity of transiting worlds around the habitable-zone. With two transits and continuous photometric ...
Zhou, Xiang; Liu, Qian; Zhang, Zhenyu; Ding, Yayun; Zhou, Li; Cao, Jun
2014-01-01
We report the measurements of the densities of linear alkylbenzene at three temperatures over 4 to 23 Celsius degree with pressures up to 10 MPa. The measurements have been analysed to yield the isobaric thermal expansion coefficients and, so far for the first time, isothermal compressibilities of linear alkylbenzene.
Highlights: • Measuring densities, viscosities and refractive index of PEG + ethanol binary system. • Examination of the excess molar volume with PFP and ERAS models. • Deducing excess expansion and other thermodynamic parameters. • Correlation of viscosity and refractive index data with various prediction equations. -- Abstract: Densities, viscosities and refractive indices of the {poly(ethylene glycol) 200 + ethanol} binary liquid system were determined at three temperatures of (298.15, 303.15, and 308.15) K. From the experimental results, the excess molar volume was obtained and correlated with the Prigogine–Flory–Patterson (PFP) and Extended Real Associated Solution (ERAS) models. Several isobaric and isothermal properties consisting of the isobaric thermal expansion coefficient, excess molar isobaric expansion, excess molar isobaric heat capacity, isothermal coefficient of excess molar enthalpy, activation energy of flow, electron polarizibility, and Gibbs energy of activation were calculated from the experimental measurements. Moreover, the viscosity and refractive index values were correlated and predicted with different semi-empirical equations. To assess the validity of these proposed equations, comparisons were made between the experimental and predicted values
Spiral structure in galaxies: analogies
Kirkpatrick, R.C.
1976-01-01
The vortex analogy to galactic spiral structures is considered. Caution against carrying the analogy past its region of applicability is noted; and some experiments with vorticities are mentioned. (JFP)
Mattiussi, Claudio; Swiss Federal Institute of Technology in Lausanne (EPFL); Marbach, Daniel; Swiss Federal Institute of Technology in Lausanne (EPFL); Dürr, Peter; Swiss Federal Institute of Technology in Lausanne (EPFL); Floreano, Dario; Swiss Federal Institute of Technology in Lausanne (EPFL)
2008-01-01
A large class of systems of biological and technological relevance can be described as analog networks, that is, collections of dynamical devices interconnected by links of varying strength. Some examples of analog networks are genetic regulatory networks, metabolic networks, neural networks, analog electronic circuits, and control systems. Analog networks are typically complex systems which include nonlinear feedback loops and possess temporal dynamics at different timescales. When tackled b...
A superconducting circuit probe for analog quantum simulators
Du, Liang-Hui; You, J. Q.; Tian, Lin
2013-01-01
Analog quantum simulators can be used to study quantum correlation in novel many-body systems by emulating the Hamiltonian of these systems. One essential question in quantum simulation is to probe the properties of an emulated many-body system. Here we present a circuit QED scheme for probing such properties by measuring the spectrum of a superconducting resonator coupled to a quantum simulator. We first study a general framework of this approach, and show that the spectrum of the resonator ...
Proposal for a digital converter of analog magnetic signals
Ertler, Christian; Fabian, Jaroslav
2006-01-01
A device which converts analog magnetic signals directly into digital information is proposed. The device concept is based on the monostable-bistable transition logic element, which consists of two resonant tunneling diodes (load and driver) connected in series and employs the monostable to bistable working point transition of the circuit. Using a magnetic resonant tunneling diode as the driver allows to control the resulting working point of the bistable region by an external magnetic field ...
Modal analysis of Bragg onion resonators
Xu, Yong; Liang, Wei; Yariv, Amnon; Fleming, James G.; Lin, Shawn-Yu
2004-01-01
From analysis of the high Q modes in a Bragg onion resonator with an omnidirectional reflector cladding, we establish a close analogy between such a resonator and a spherical hollow cavity in perfect metal. We demonstrate that onion resonators are ideal for applications that require a large spontaneous-emission factor ß, such as thresholdless lasers and single-photon devices.
Applications of resonance ionization spectroscopy to ultralow-level counting and mass spectroscopy
In this paper it is shown that the ability to directly detect a daughter atom, using resonance ionization spectroscopy, in delayed time coincidence with the decay of a parent species promises to drastically reduce the background in low-level counting experiments. In addition, resonance ionization can also be used as an ion source for a mass spectrometer system that is capable of discriminating between isobars
ESD analog circuits and design
Voldman, Steven H
2014-01-01
A comprehensive and in-depth review of analog circuit layout, schematic architecture, device, power network and ESD design This book will provide a balanced overview of analog circuit design layout, analog circuit schematic development, architecture of chips, and ESD design. It will start at an introductory level and will bring the reader right up to the state-of-the-art. Two critical design aspects for analog and power integrated circuits are combined. The first design aspect covers analog circuit design techniques to achieve the desired circuit performance. The second and main aspect pres
Izadi, F A; Bagirov, G
2009-01-01
With its origins stretching back several centuries, discrete calculus is now an increasingly central methodology for many problems related to discrete systems and algorithms. The topics covered here usually arise in many branches of science and technology, especially in discrete mathematics, numerical analysis, statistics and probability theory as well as in electrical engineering, but our viewpoint here is that these topics belong to a much more general realm of mathematics; namely calculus and differential equations because of the remarkable analogy of the subject to this branch of mathemati
Lyon, Richard F.; Mead, Carver
1988-01-01
An engineered system that hears, such as a speech recognizer, can be designed by modeling the cochlea, or inner ear, and higher levels of the auditory nervous system. To be useful in such a system, a model of the cochlea should incorporate a variety of known effects, such as an asymmetric low-pass/bandpass response at each output channel, a short ringing time, and active adaptation to a wide range of input signal levels. An analog electronic cochlea has been built in CMOS VLSI technolog...
Energy Harvesting Using an Analog Circuit under Multimodal Vibration
Shigeru Shimose
2013-01-01
Full Text Available The efficiency of harvesting energy from a vibrating structure using a piezoelectric transducer and a simple analog circuit is investigated experimentally. This analog circuit was originally invented for a synchronized switch damping on inductor (SSDI technique, which enhances the damping of mechanical vibration. In this study, the circuit is used to implement a synchronized switch harvesting on inductor (SSHI technique. A multiple degree of freedom (MDOF structure is excited by single sinusoidal forces at its resonant frequencies and by random forces. The piezoelectric transducer converts this mechanical energy into electrical energy which is harvested using a standard rectifier bridge circuit with and without our analog circuit. Experimental results show that our analog circuit makes it possible to harvest twice as much energy under both single sinusoidal and random vibration excitations.
Isbell, Theresa A; Strickland, Erin C; Hitchcock, Jennifer; McIntire, Gregory; Colyer, Christa L
2015-02-01
The determination of morphine and its isobaric metabolites morphine-3-beta-d-glucuronide (M3G) and morphine-6-beta-d-glucuronide (M6G) is useful for therapeutic drug monitoring and forensic identification of drug use. In particular, capillary electrophoresis with mass spectrometry (CE-MS) represents an attractive tool for opioid analysis. Whereas volatile background electrolytes in CE often improve electrospray ionization for coupled MS detection, such electrolytes may reduce CE separation efficiency and resolution. To better understand the effects of background electrolyte (BGE) composition on separation efficiency and detection sensitivity, this work compares and contrasts method development for both volatile (ammonium formate and acetate) and nonvolatile (ammonium phosphate and borate) buffers. Peak efficiencies and migration times for morphine and morphine metabolites were optimal with a 25mM ammonium borate buffer (pH=9.5) although greater sensitivities were achieved in the ammonium formate buffer. Optimized CE methods allowed for the resolution of the isobaric morphine metabolites prior to high mass accuracy, electrospray ionization quadrupole time-of-flight (ESI-QTOF) MS detection applicable to the analysis of urine samples in under seven minutes. Urine sample preparation required only a 10-fold dilution with BGE prior to analysis. Limits of detection (LOD) in normal human urine were found to be 1.0μg/mL for morphine and 2.5μg/mL for each of M3G and M6G by CE-ESI-QTOF-MS. These LODs were comparable to those for CE-UV analysis of opioid standards in buffer, whereas CE-ESI-QTOF-MS analysis of opioid standards in buffer yielded LODs an order of magnitude lower. Patient urine samples (N=12) were analyzed by this new CE-ESI-QTOF-MS method and no significant difference in total morphine content relative to prior liquid chromatography-mass spectrometry (LC-MS) results was found as per a paired-t test at the 99% confidence level. Whereas the LC-MS method applied
Cropp, Bethan; Liberati, Stefano; Turcati, Rodrigo
2016-06-01
In the analog gravity framework, the acoustic disturbances in a moving fluid can be described by an equation of motion identical to a relativistic scalar massless field propagating in curved space-time. This description is possible only when the fluid under consideration is barotropic, inviscid, and irrotational. In this case, the propagation of the perturbations is governed by an acoustic metric that depends algebrically on the local speed of sound, density, and the background flow velocity, the latter assumed to be vorticity-free. In this work we provide a straightforward extension in order to go beyond the irrotational constraint. Using a charged—relativistic and nonrelativistic—Bose–Einstein condensate as a physical system, we show that in the low-momentum limit and performing the eikonal approximation we can derive a d’Alembertian equation of motion for the charged phonons where the emergent acoustic metric depends on flow velocity in the presence of vorticity.
Ochoa, Agustin
2016-01-01
This book describes a consistent and direct methodology to the analysis and design of analog circuits with particular application to circuits containing feedback. The analysis and design of circuits containing feedback is generally presented by either following a series of examples where each circuit is simplified through the use of insight or experience (someone else’s), or a complete nodal-matrix analysis generating lots of algebra. Neither of these approaches leads to gaining insight into the design process easily. The author develops a systematic approach to circuit analysis, the Driving Point Impedance and Signal Flow Graphs (DPI/SFG) method that does not require a-priori insight to the circuit being considered and results in factored analysis supporting the design function. This approach enables designers to account fully for loading and the bi-directional nature of elements both in the feedback path and in the amplifier itself, properties many times assumed negligible and ignored. Feedback circuits a...
Differentiating Isobaric Steroid Hormone Metabolites Using Multi-Stage Tandem Mass Spectrometry
Tedmon, Lauren; Barnes, Jeremy S.; Nguyen, Hien P.; Schug, Kevin A.
2013-03-01
Steroid hormones and their metabolites are currently undergoing clinical trials as potential therapeutics for traumatic brain injury (TBI). To support this work, it is necessary to develop improved procedures for differentiating isobaric species in this compound class. Equilin sulfate (E-S), estrone sulfate (E1-S), 17α-dihydroequilin sulfate (ADHE-S), and 17β-dihydroequilin sulfate (BDHE-S) are primary constituents in hormone replacement therapies, such as Premarin, which are among pharmaceuticals being investigated for TBI treatment. The latter three compounds are isomers and can be difficult to differentiate in trace analytical determinations. In this work, a systematic study of the fragmentation of ADHE-S, BDHE-S, E1-S, and E-S under different stages of higher order tandem mass spectrometry (MSn) and variation of collision energy, allowed optimization of conditions for distinguishing the isomeric structures. For epimeric variants (e.g., ADHE-S versus BDHE-S; α- versus β-stereoisomerization in the C-17 position), differentiation was achieved at MS4 and fragmentation was demonstrated through MS5. Computational analysis was performed to further explore differences in the fragmentation pathways due to changes in stereochemistry.
Astrocytes are essential components of neurogenic niches that affect neurogenesis through membrane association and/or the release of soluble factors. To identify factors released from astrocytes that could regulate neural stem cell differentiation and proliferation, we used mild oxygen-glucose deprivation (OGD) to inhibit the secretory capacity of astrocytes. Using the Transwell co-culture system, we found that OGD-treated astrocytes could not promote neural stem cell differentiation and proliferation. Next, isobaric tagging for the relative and absolute quantitation (iTRAQ) proteomics techniques was performed to identify the proteins in the supernatants of astrocytes (with or without OGD). Through a multi-step analysis and gene ontology classification, 130 extracellular proteins were identified, most of which were involved in neuronal development, the inflammatory response, extracellular matrix composition and supportive functions. Of these proteins, 44 had never been reported to be produced by astrocytes. Using ProteinPilot software analysis, we found that 60 extracellular proteins were significantly altered (27 upregulated and 33 downregulated) in the supernatant of OGD-treated astrocytes. Among these proteins, 7 have been reported to be able to regulate neurogenesis, while others may have the potential to regulate neurogenesis. This study profiles the major proteins released by astrocytes, which play important roles in the modulation of neurogenesis.
Kudasik, Mateusz
2016-03-01
The present paper discusses the concept of measuring the process of sorption by means of the volumetric method, developed in such a way as to allow measurements performed under isobaric conditions. On the basis of the concept in question, a prototype of a sorption instrument was built: the manometric sorptomat. The paper provides a detailed description of the idea of the instrument, and of the way it works. In order to evaluate the usefulness of the device in sorption measurements carried out under laboratory conditions, comparative studies were conducted, during which the results of sorption measurements obtained with the developed instrument were compared with the results Mateusz obtained with a reference device. The objects of comparison were the sorption capacities of hard coal samples, calculated on the basis of the established courses of the methane sorption process. The results were regarded as compatible if the compared values fell within the range of the measurement uncertainty of the two devices. For the sake of the comparative studies, fifteen granular samples of hard coal—representing the 0.20-0.25 mm grain fraction and coming from various mines of the Upper Silesian Coal Basin—were used. After comparing the results obtained with the original manometric sorptomat with the results obtained with the gravimetric reference device, it was observed that the compatibility of measurements of sorption capacities was over 90%, based on the defined criterion of the measurement compatibility.
Sensitivity of N/Z ratio in projectile break-up of isobaric systems
De Filippo E.
2016-01-01
Full Text Available The binary break-up of projectile-like fragments in non central heavy-ion collisions follows different decay patterns, from equilibrated emission towards dynamical (prompt fission. Recently, comparing two systems with different N/Z in the entrance channel, it has been shown that the dynamical emission cross-section is enhanced for the most neutron rich system while the statistical emission cross-section is independent from the isotopic composition. In order to understand this dependence and disentangle it from the initial size of the nuclei, we have studied the two isobaric systems 124Xe+64 Zn and 124Xe+64 Ni at 35 A MeV (InKiIsSy experiment, in comparison with the previous studied reactions (124Sn +64 Ni and 112Sn +58 Ni at the same bombarding energy. We present the first results evidencing a striking similar effect in the dynamical decay as a function of the N/Z of the target for equal size systems.
Pleik, Stefanie; Spengler, Bernhard; Schäfer, Thomas; Urbach, Dieter; Luhn, Steven; Kirsch, Dieter
2016-07-01
Isobaric labeling is a powerful strategy for quantitative mass spectrometry-based proteomic investigations. A complication of such analyses has been the co-isolation of multiple analytes of similar mass-to-charge resulting in the distortion of relative protein abundance measurements across samples. When properly implemented, synchronous precursor selection and triple-stage mass spectrometry (SPS-MS3) can reduce the occurrence of this phenomenon, referred to as ion interference. However, no diagnostic tool is available currently to rapidly and accurately assess ion interference. To address this need, we developed a multiplexed tandem mass tag (TMT)-based standard, termed the triple knockout (TKO). This standard is comprised of three yeast proteomes in triplicate, each from a strain deficient in a highly abundant protein (Met6, Pfk2, or Ura2). The relative abundance patterns of these proteins, which can be inferred from dozens of peptide measurements can demonstrate ion interference in peptide quantification. We expect no signal in channels where the protein is knocked out, permitting maximum sensitivity for measurements of ion interference against a null background. Here, we emphasize the need to investigate further ion interference-generated ratio distortion and promote the TKO standard as a tool to investigate such issues.
Yan, Hu; Zhou, Wenhao [Children' s Hospital of Fudan University, 399 Wanyuan Road, Shanghai 201102 (China); Wei, Liming; Zhong, Fan [Institutes of Biomedical Sciences, Fudan University, 138 Yixueyuan Roda, Shanghai 200032 (China); Yang, Yi, E-mail: yyang@shmu.edu.cn [Children' s Hospital of Fudan University, 399 Wanyuan Road, Shanghai 201102 (China)
2010-01-08
Astrocytes are essential components of neurogenic niches that affect neurogenesis through membrane association and/or the release of soluble factors. To identify factors released from astrocytes that could regulate neural stem cell differentiation and proliferation, we used mild oxygen-glucose deprivation (OGD) to inhibit the secretory capacity of astrocytes. Using the Transwell co-culture system, we found that OGD-treated astrocytes could not promote neural stem cell differentiation and proliferation. Next, isobaric tagging for the relative and absolute quantitation (iTRAQ) proteomics techniques was performed to identify the proteins in the supernatants of astrocytes (with or without OGD). Through a multi-step analysis and gene ontology classification, 130 extracellular proteins were identified, most of which were involved in neuronal development, the inflammatory response, extracellular matrix composition and supportive functions. Of these proteins, 44 had never been reported to be produced by astrocytes. Using ProteinPilot software analysis, we found that 60 extracellular proteins were significantly altered (27 upregulated and 33 downregulated) in the supernatant of OGD-treated astrocytes. Among these proteins, 7 have been reported to be able to regulate neurogenesis, while others may have the potential to regulate neurogenesis. This study profiles the major proteins released by astrocytes, which play important roles in the modulation of neurogenesis.
Xiao, Ziya; Xue, Yuan; Yao, Chenling; Gu, Guorong; Zhang, Yaping; Zhang, Jin; Fan, Fan; Luan, Xiao; Deng, Zhi; Tao, Zhengang; Song, Zhen-Ju; Tong, Chaoyang; Wang, Haojun
2016-01-01
The purpose of this study was to evaluate the utility of potential serum biomarkers for acute aortic dissection (AAD) that were identified by isobaric Tags for Relative and Absolute Quantitation (iTRAQ) approaches. Serum samples from 20 AAD patients and 20 healthy volunteers were analyzed using iTRAQ technology. Protein validation was performed using samples from 120 patients with chest pain. A total of 355 proteins were identified with the iTRAQ approach; 164 proteins reached the strict quantitative standard, and 125 proteins were increased or decreased more than 1.2-fold (64 and 61 proteins were up- and downregulated, resp.). Lumican, C-reactive protein (CRP), thrombospondin-1 (TSP-1), and D-dimer were selected as candidate biomarkers for the validation tests. Receiver operating characteristic (ROC) curves show that Lumican and D-dimer have diagnostic value (area under the curves [AUCs] 0.895 and 0.891, P values for D-dimer were 93.33% and 68.33%. For Lumican and D-dimer AAD combined diagnosis, the sensitivity and specificity were 88.33% and 95%, respectively. In conclusion, Lumican has good specificity and D-dimer has good sensitivity for the diagnosis of AAD, while the combined detection of D-dimer and Lumican has better diagnostic value. PMID:27403433
Monte Carlo Molecular Simulation with Isobaric-Isothermal and Gibbs-NPT Ensembles
Du, Shouhong
2012-05-01
This thesis presents Monte Carlo methods for simulations of phase behaviors of Lennard-Jones fluids. The isobaric-isothermal (NPT) ensemble and Gibbs-NPT ensemble are introduced in detail. NPT ensemble is employed to determine the phase diagram of pure component. The reduced simulation results are verified by comparison with the equation of state by by Johnson et al. and results with L-J parameters of methane agree considerably with the experiment measurements. We adopt the blocking method for variance estimation and error analysis of the simulation results. The relationship between variance and number of Monte Carlo cycles, error propagation and Random Number Generator performance are also investigated. We review the Gibbs-NPT ensemble employed for phase equilibrium of binary mixture. The phase equilibrium is achieved by performing three types of trial move: particle displacement, volume rearrangement and particle transfer. The simulation models and the simulation details are introduced. The simulation results of phase coexistence for methane and ethane are reported with comparison of the experimental data. Good agreement is found for a wide range of pressures. The contribution of this thesis work lies in the study of the error analysis with respect to the Monte Carlo cycles and number of particles in some interesting aspects.
Capaccioli, S [Dipartimento di Fisica, Universita di Pisa, Largo B. Pontecorvo 3, I-56127, Pisa (Italy); Kessairi, K [Dipartimento di Fisica, Universita di Pisa, Largo B. Pontecorvo 3, I-56127, Pisa (Italy); Prevosto, D [Dipartimento di Fisica, Universita di Pisa, Largo B. Pontecorvo 3, I-56127, Pisa (Italy); Lucchesi, M [Dipartimento di Fisica, Universita di Pisa, Largo B. Pontecorvo 3, I-56127, Pisa (Italy); Rolla, P A [Dipartimento di Fisica, Universita di Pisa, Largo B. Pontecorvo 3, I-56127, Pisa (Italy)
2007-05-23
The effect of isobaric cooling (over the range 190-350 K) and isothermal compression (up to 700 MPa) on structural {alpha}- and secondary {beta}-relaxations has been studied for low molecular weight glass-forming systems. The shape of the {alpha}-loss peak was found to change with temperature T and pressure P but to be constant for a combination of T and P giving the same {tau}{sub {alpha}}(T,P). The invariance of shape at constant {tau}{sub {alpha}}(T,P) involved also the excess wing, i.e. the process showing up at the high-frequency tail of the {alpha}-loss peak in systems with no well-resolved {beta}-process. Likewise, systems where the excess wing evolved to a well-resolved {beta}-peak showed that the timescale of the {beta}-process was strongly related to that of the {alpha}-peak. Also in this case, once a given value {tau}{sub {alpha}}(T,P) was fixed, a corresponding value {tau}{sub {beta}}(T,P) was found for different T and P. Same results were found also for a binary mixture of a polar rigid molecule dissolved in an apolar solvent, i.e. a model system for Johari-Goldstein intermolecular relaxation. These evidences imply that a strong correlation exists between structural {alpha}- and Johari-Goldstein relaxation over a wide interval of temperature and density.
Selective isobar suppression for accelerator mass spectrometry and radioactive ion-beam science
A new method of selective isobar suppression by photodetachment in a radio-frequency quadrupole ion cooler is being developed at HRIBF with a twofold purpose: (1) increasing the AMS sensitivity for certain isotopes of interest and (2) purifying radioactive ion beams for nuclear science. The potential of suppressing the 36S contaminants in a 36Cl beam using this method has been explored with stable S- and Cl- ions and a Nd:YLF laser. In the study, the laser beam was directed along the experiment's beam line and through a RF quadrupole ion cooler. Negative 32S and 35Cl ions produced by a Cs sputter ion source were focused into the ion cooler where they were slowed by collisions with He buffer gas; this increased the interaction time between the negative-ion beam and the laser beam. As a result, suppression of S- by a factor of 3000 was obtained with about 2.5 W average laser power in the cooler while no reduction in Cl- current was observed.
Mass of astrophysically relevant $^{31}$Cl and the breakdown of the isobaric multiplet mass equation
Kankainen, A; Eronen, T; Hakala, J; Jokinen, A; Koponen, J; Moore, I D; Nesterenko, D; Reinikainen, J; Rinta-Antila, S; Voss, A; Äystö, J
2015-01-01
The mass of $^{31}$Cl has been measured with the JYFLTRAP double Penning trap mass spectrometer at the Ion-Guide Isotope Separator On-Line (IGISOL) facility. The determined mass-excess value, -7034.7(34) keV, is 15 times more precise than in the Atomic Mass Evaluation 2012. The quadratic form of the isobaric multiplet mass equation for the T=3/2 quartet at A=31 fails ($\\chi^2_n$=11.6) and a non-zero cubic term, d=-3.49(44) keV, is obtained when the new mass value is adopted. $^{31}$Cl has been found to be less proton-bound with a proton separation energy of $S_p$=265(4) keV. Energies for the excited states in $^{31}$Cl and the photodisintegration rate on $^{31}$Cl have been determined with significantly improved precision using the new $S_p$ value. The improved photodisintegration rate helps to constrain astrophysical conditions where $^{30}$S can act as a waiting point in the rapid proton capture process in type I x-ray bursts.
Volume crossover in deeply supercooled water adiabatically freezing under isobaric conditions
Aliotta, Francesco; Giaquinta, Paolo V.; Pochylski, Mikolaj; Ponterio, Rosina C.; Prestipino, Santi; Saija, Franz; Vasi, Cirino
2013-05-01
The irreversible return of a supercooled liquid to stable thermodynamic equilibrium often begins as a fast process which adiabatically drives the system to solid-liquid coexistence. Only at a later stage will solidification proceed with the expected exchange of thermal energy with the external bath. In this paper we discuss some aspects of the adiabatic freezing of metastable water at constant pressure. In particular, we investigated the thermal behavior of the isobaric gap between the molar volume of supercooled water and that of the warmer ice-water mixture which eventually forms at equilibrium. The available experimental data at ambient pressure, extrapolated into the metastable region within the scheme provided by the reference IAPWS-95 formulation, show that water ordinarily expands upon (partially) freezing under isenthalpic conditions. However, the same scheme also suggests that, for increasing undercoolings, the volume gap is gradually reduced and eventually vanishes at a temperature close to the currently estimated homogeneous ice nucleation temperature. This behavior is contrasted with that of substances which do not display a volumetric anomaly. The effect of increasing pressures on the alleged volume crossover from an expanded to a contracted ice-water mixture is also discussed.
The effect of isobaric cooling (over the range 190-350 K) and isothermal compression (up to 700 MPa) on structural α- and secondary β-relaxations has been studied for low molecular weight glass-forming systems. The shape of the α-loss peak was found to change with temperature T and pressure P but to be constant for a combination of T and P giving the same τα(T,P). The invariance of shape at constant τα(T,P) involved also the excess wing, i.e. the process showing up at the high-frequency tail of the α-loss peak in systems with no well-resolved β-process. Likewise, systems where the excess wing evolved to a well-resolved β-peak showed that the timescale of the β-process was strongly related to that of the α-peak. Also in this case, once a given value τα(T,P) was fixed, a corresponding value τβ(T,P) was found for different T and P. Same results were found also for a binary mixture of a polar rigid molecule dissolved in an apolar solvent, i.e. a model system for Johari-Goldstein intermolecular relaxation. These evidences imply that a strong correlation exists between structural α- and Johari-Goldstein relaxation over a wide interval of temperature and density
Analogy-Based Expectation Equilibrium
Jehiel, P
2001-01-01
It is assumed that players bundle nodes in which other players must move into analogy classes, and players only have expectations about the average behavior in every class. A solution concept is proposed for multi-stage games with perfect information: at every node players choose best-responses to their analogy-based expectations, and expectations are correct on average over those various nodes pooled together into the same analogy classes. The approach is applied to a variety of games. It is...
Beginning analog electronics through projects
Singmin, Andrew
2001-01-01
Analog electronics is the simplest way to start a fun, informative, learning program. Beginning Analog Electronics Through Projects, Second Edition was written with the needs of beginning hobbyists and students in mind. This revision of Andrew Singmin's popular Beginning Electronics Through Projects provides practical exercises, building techniques, and ideas for useful electronics projects. Additionally, it features new material on analog and digital electronics, and new projects for troubleshooting test equipment.Published in the tradition of Beginning Electronics Through Projects an
Analog and digital signal processing
Baher, H.
The techniques of signal processing in both the analog and digital domains are addressed in a fashion suitable for undergraduate courses in modern electrical engineering. The topics considered include: spectral analysis of continuous and discrete signals, analysis of continuous and discrete systems and networks using transform methods, design of analog and digital filters, digitization of analog signals, power spectrum estimation of stochastic signals, FFT algorithms, finite word-length effects in digital signal processes, linear estimation, and adaptive filtering.
jTraqX: a free, platform independent tool for isobaric tag quantitation at the protein level.
Muth, Thilo; Keller, Daniela; Puetz, Stephanie Michaela; Martens, Lennart; Sickmann, Albert; Boehm, Andreas M
2010-03-01
Many proteomic studies focus on quantitative aspects, using different stable isotope labeling techniques that require specialized software to analyze the generated data. Here we present jTraqX, an easy-to-use tool for processing and visualizing protein quantification data. jTraqX is platform independent and is compatible with all available 4-plex isobaric tags. jTraqX can be freely downloaded at http://sourceforge.net/projects/protms. PMID:20058250