155 research outputs found

    Large scale shell model calculations for odd-odd 58−62^{58-62}Mn isotopes

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    Large scale shell model calculations have been carried out for odd-odd 58−62^{58-62}Mn isotopes in two different model spaces. First set of calculations have been carried out in full fp\it{fp} shell valence space with two recently derived fp\it{fp} shell interactions namely GXPF1A and KB3G treating 40^{40}Ca as core. The second set of calculations have been performed in fpg9/2{fpg_{9/2}} valence space with the fpgfpg interaction treating 48^{48}Ca as core and imposing a truncation by allowing up to a total of six particle excitations from the 0f7/2_{7/2} orbital to the upper fp\it{fp} orbitals for protons and from the upper fp\it{fp} orbitals to the 0g9/2_{9/2} orbital for neutron. For low-lying states in 58^{58}Mn, the KB3G and GXPF1A both predicts good results and for 60^{60}Mn, KB3G is much better than GXPF1A. For negative parity and high-spin positive parity states in both isotopes fpgfpg interaction is required. Experimental data on 62^{62}Mn is sparse and therefore it is not possible to make any definite conclusions. More experimental data on negative parity states is needed to ascertain the importance of 0g9/2_{9/2} and higher orbitals in neutron rich Mn isotopes.Comment: 5 pages, 4 figures, Submitted to Eur. Phys. J.

    Digital Cognitive Behavioral Therapy for Insomnia in Women With Chronic Migraines

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    Objective/Background: Insomnia commonly co-occurs with chronic migraines (CM). Non-pharmacological treatments for insomnia in CM patients remain understudied. This is a proof-of-concept study, which aims to evaluate the feasibility, acceptability, and preliminary efficacy of a digital cognitive behavioral therapy for insomnia (dCBT-I) for individuals with CM and insomnia (CM-I) in the United States. Methods: We recruited 42 females with CM-I symptoms from a U.S.-based observational cohort and from the general population via advertisements. Within a multiple baseline design, participants were randomized to receive dCBT-I after 2, 4, or 6 weeks of completing baseline sleep diaries. DCBT-I was scrutinized against benchmarks for completion rates (≥90% to complete dCBT-I), acceptability (≥80% to find dCBT-I acceptable), and posttreatment changes in insomnia symptoms (≥50% indicating a clinically relevant improvement in their insomnia symptoms). As a secondary measure, we also reported percentage of individuals reverting to episodic migraines. Results: Out of 42 randomized, 35 (83.3%) completed dCBT-I within the 12 weeks provided. Of these completers, 33 (94.3%) reported being satisfied (n = 16) or very satisfied (n = 17) with treatment. Additionally, 65.7% of completers responded to treatment as per universally accepted criteria for insomnia. Lastly, 34% of completers reverted from CM to episodic migraine. Conclusion: This study provides evidence for the feasibility and acceptability of dCBT-I in patients with CM-I complaints. Effects of improving insomnia and migraines were suggested. These results indicate that a randomized controlled trial is needed to determine the efficacy of dCBT-I in CM patients

    Fast switching NMR system for measurements of ground-state quadrupole moments of short-lived nuclei

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    A beta-ray detecting nuclear quadrupole resonance system has been developed at NSCL/MSU to measure ground-state electric quadrupole moments of short-lived nuclei produced as fast rare isotope beams. This system enables quick and sequential application of multiple transition frequencies over a wide range. Fast switching between variable capacitors in resonance circuits ensures sufficient power delivery to the coil in the beta-ray detecting nuclear magnetic resonance technique. The fast switching technique enhances detection efficiency of resonance signals and is especially useful when the polarization and/or production rate of the nucleus of interest are small and when the nuclear spin is large

    Measures of process harmonization

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    Context Many large organizations juggle an application portfolio that contains different applications that fulfill similar tasks in the organization. In an effort to reduce operating costs, they are attempting to consolidate such applications. Before consolidating applications, the work that is done with these applications must be harmonized. This is also known as process harmonization. Objective The increased interest in process harmonization calls for measures to quantify the extent to which processes have been harmonized. These measures should also uncover the factors that are of interest when harmonizing processes. Currently, such measures do not exist. Therefore, this study develops and validates a measurement model to quantify the level of process harmonization in an organization. Method The measurement model was developed by means of a literature study and structured interviews. Subsequently, it was validated through a survey, using factor analysis and correlations with known related constructs. Results As a result, a valid and reliable measurement model was developed. The factors that are found to constitute process harmonization are: the technical design of the business process and its data, the resources that execute the process, and the information systems that are used in the process. In addition, strong correlations were found between process harmonization and process standardization and between process complexity and process harmonization. Conclusion The measurement model can be used by practitioners, because it shows them the factors that must be taken into account when harmonizing processes, and because it provides them with a means to quantify the extent to which they succeeded in harmonizing their processes. At the same time, it can be used by researchers to conduct further empirical research in the area of process harmonization

    Small Polarons in Transition Metal Oxides

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    The formation of polarons is a pervasive phenomenon in transition metal oxide compounds, with a strong impact on the physical properties and functionalities of the hosting materials. In its original formulation the polaron problem considers a single charge carrier in a polar crystal interacting with its surrounding lattice. Depending on the spatial extension of the polaron quasiparticle, originating from the coupling between the excess charge and the phonon field, one speaks of small or large polarons. This chapter discusses the modeling of small polarons in real materials, with a particular focus on the archetypal polaron material TiO2. After an introductory part, surveying the fundamental theoretical and experimental aspects of the physics of polarons, the chapter examines how to model small polarons using first principles schemes in order to predict, understand and interpret a variety of polaron properties in bulk phases and surfaces. Following the spirit of this handbook, different types of computational procedures and prescriptions are presented with specific instructions on the setup required to model polaron effects.Comment: 36 pages, 12 figure

    Low-energy structure of Mn61 populated following β decay of Cr61

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    β decay of the Cr6137 ground state has been studied. A new half-life of 233±11 ms has been deduced, and seven delayed γ rays have been assigned to the daughter Mn6136. The low-energy level structure of Mn6136 is similar to that of the less neutron-rich Mn57,59 nuclei. The odd-A25Mn isotopes follow the systematic trend in the yrast states of the even-even, Z+1 26Fe isotopes, and not that of the Z-1 24Cr isotopes, where a possible onset of collectivity has been suggested to occur already at N=36

    Search for the 1/2+ intruder state in P 35

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    The excitation energy of deformed intruder states (specifically the 2p2h bandhead) as a function of proton number Z along N=20 is of interest both in terms of better understanding the evolution of nuclear structure between spherical Ca40 and the Island of Inversion nuclei, and for benchmarking theoretical descriptions in this region. At the center of the N=20 Island of Inversion, the npnh (where n=2,4,6) neutron excitations across a diminished N=20 gap result in deformed and collective ground states, as observed in Mg32. In heavier isotones, npnh excitations do not dominate in the ground states but are present in the relatively low-lying level schemes. With the aim of identifying the expected 2p2h - s1/2+ state in P35, the only N=20 isotone for which the neutron 2p2h excitation bandhead has not yet been identified, the S36(d,He3)P35 reaction has been revisited in inverse kinematics with the HELical Orbit Spectrometer (HELIOS) at the Argonne Tandem Linac Accelerator System (ATLAS). While a candidate state has not been located, an upper limit for the transfer reaction cross section to populate such a configuration within a 2.5 to 3.6 MeV energy range provides a stringent constraint on the wave function compositions in both S36 and P35

    β Decay and isomeric properties of neutron-rich Ca and Sc isotopes

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    The isomeric and β-decay properties of neutron-rich Sc53-57 and Ca53,54 nuclei near neutron number N=32 are reported, and the low-energy level schemes of Sc53,54,56 and Ti53-57 are presented. The low-energy level structures of the 21Sc isotopes are discussed in terms of the coupling of the valence 1f7/2 proton to states in the corresponding 20Ca cores. Implications with respect to the robustness of the N=32 subshell closure are discussed, as well as the repercussions for a possible N=34 subshell closure

    β decay of neutron-rich Ca53-56

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    β-decay properties of neutron-rich Ca isotopes have been obtained. Half-life values were determined for the first time for Ca54 (86±7 ms), Ca55 (22±2 ms), and Ca56 (11±2 ms). The half-life of 230±60 ms deduced for Ca53 is significantly longer than reported previously, where the decay chain K53 → Ca53 → Sc53 was considered. A delayed γ ray with an energy of 247 keV was identified following β decay of Ca54 and is proposed to depopulate the 11+ level in Sc54. The β-decay properties compare favorably with the results of shell-model calculations completed in the full pf space with the GXPF1 interaction. The half-lives of the neutron-rich Ca isotopes are also compared with gross β-decay theory. The systematic trend of the neutron-rich Ca half-lives is consistent with the presence of a subshell gap at N=32
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