45 research outputs found

    In-beam spectroscopic study of 244Cf

    Get PDF
    The ground-state rotational band of the neutron-deficient californium (Z = 98) isotope 244Cf was identified for the first time and measured up to a tentative spin and parity of I = 20+. The observation of the rotational band indicates that the nucleus is deformed. The kinematic and dynamic moments of inertia were deduced from the measured gamma-ray transition energies. The behavior of the dynamic moment of inertia revealed an up-bend due to a possible alignment of coupled nucleons in high-j orbitals starting at a rotational frequency of about hw = 0.20 MeV. The results were compared with the systematic behavior of the even-even N = 146 isotones as well as with available theoretical calculations that have been performed for nuclei in the region

    In-beam spectroscopic study of Cf-244

    Get PDF
    The ground-state rotational band of the neutron-deficient californium (Z = 98) isotope 244Cf was identified for the first time and measured up to a tentative spin and parity of I I-pi = 20(+). The observation of the rotational band indicates that the nucleus is deformed. The kinematic and dynamic moments of inertia were deduced from the measured gamma-ray transition energies. The behavior of the dynamic moment of inertia revealed an up-bend due to a possible alignment of coupled nucleons in high-j orbitals starting at a rotational frequency of about (h) over bar (omega) = 0.20 MeV. The results were compared with the systematic behavior of the even-even N = 146 isotones as well as with available theoretical calculations that have been performed for nuclei in the region.Peer reviewe

    Investigation on Geometrical Complexity Techniques for Assessing AM Feasibility

    No full text
    Currently, there is a growing interest of industries in applying additive manufacturing (AM) technology for generating objects with high geometrical complexity and low weight, ensuring good performance, comparable to those ones of products realized by means of traditional techniques. Anyway, it is still usual to realize AM products without focusing on the morphology of the object, hence without exploiting all the advantages of the technique. Indeed, since the several suitable AM technologies, it should be useful to know the functional characteristics of the component for the best choice of the appropriate one and its constructive complexity. In this regard, the 3D modeling strategy is extremely crucial for a proper realization of AM products. The paper deals with a study of the geometrical complexity of dashboard components of a car, based on several techniques for evaluating the geometric complexity. The latter is a fundamental element for estimating the feasibility of AM in terms of production costs and the benefits with respect to traditional molding. In detail, the study focuses on comparing several geometrical complexity evaluation techniques in order to identify the one that simplifies the calculation and better approximates the most used in literature

    "Association of calpastatin with inactive calpain: a novel mechanism to control the activation of the protease?"

    No full text
    It is generally accepted that the Ca2-dependent interaction of calpain with calpastatin is the most relevant mechanism involved in the regulation of Ca2-induced proteolysis.Wenow report that a calpain-calpastatin association can occur also in the absence of Ca2 or at very low Ca2 concentrations, reflecting the physiological conditions under which calpain retains its inactive conformational state. The calpastatin binding region is localized in the non-inhibitory L-domain containing the amino acid sequences encoded by exons 4\u20137. This calpastatin region recognizes a calpain sequence located near the end of the DIIdomain. Interaction of calpain with calpastatins lacking these sequences becomes strictly Ca2-dependent because, under these conditions, the transition to an active state of the protease is an obligatory requirement. The occurrence of the molecular association between Ca2-free calpain and various recombinant calpastatin forms has been demonstrated by the following experimental results. Addition of calpastatin protected calpain from trypsin digestion. Calpain was coprecipitated when calpastatin was immunoprecipitated. The calpastatin molecular size increased following exposure to calpain. The two proteins comigrated in zymogram analysis. Furthermore, calpain-calpastatin interaction was perturbed by protein kinaseCphosphorylation occurring at sites located at the exons involved in the association. At a functional level, calpain-calpastatin interaction at a physiological concentration of Ca2 represents a novel mechanism for the control of the amount of the active form of the protease potentially generated in response to an intracellular Ca2 influx

    Prompt and delayed spectroscopy of At-203: Observation of a shears band and a 29/2(+) isomeric state

    No full text
    Using fusion-evaporation reactions, a gas-filled recoil separator, recoil-gating technique and recoil-isomer decay tagging technique we have extended the level scheme of 203 At ( N = 118 ) significantly. We have observed an isomeric [ τ = 14.1 ( 3 ) μ s ] state with a spin and parity of 29 / 2 + . The isomeric state is suggested to originate from the π ( h 9 / 2 ) ⊗ ∣ ∣ 202 Po ; 11 − ⟩ coupling, and it is depopulated through 286 keV E 2 and 366 keV E 3 transitions. In addition, we have observed a cascade of magnetic-dipole transitions which is suggested to be generated by the shears mechanism.peerReviewe
    corecore