752 research outputs found

    No-Core Shell Model for Nuclear Systems with Strangeness

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    We report on a novel ab initio approach for nuclear few- and many-body systems with strangeness. Recently, we developed a relevant no-core shell model technique which we successfully applied in first calculations of lightest Λ\Lambda hypernuclei. The use of a translationally invariant finite harmonic oscillator basis allows us to employ large model spaces, compared to traditional shell model calculations, and use realistic nucleon-nucleon and nucleon-hyperon interactions (such as those derived from EFT). We discuss formal aspects of the methodology, show first demonstrative results for Λ3{}_{\Lambda}^3H, Λ4{}_{\Lambda}^4H and Λ4{}^4_\LambdaHe, and give outlook.Comment: 4 pages, 3 figures; Proceedings of the 22nd European Conference on Few Body Problems in Physics, 9 - 13 September, 2013, Cracow, Polan

    Automated Classification of Bioprocess Based on Optimum Compromise Whitening and Clustering

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    The proposed methodology of technological state classification is based on data smoothing, dimensionality reduction, compromise whitening, and optimum clustering. The novelty of our approach is in the stabile state hypothesis which improves initialization of c-mean algorithm and enables interleaved cross-validation strategy. We also employ the Akaike information criterion to obtain the optimum number of technological states that minimize it, but using as many as possible clusters and components. The general approach is applied to state classification of Pseudomonas putida fed-batch cultivation on octanoic acid

    Optimizing car tailgate design through truss topology optimization

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    This study received funding from NCK2-Bovenac 4-WP10-003 and the Grant Agency of the Czech Technical University in Prague, under grant No. SGS21/151/OHK2/3T/12

    Bernoulli potential in type-I and weak type-II supercoductors: II. Surface dipole

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    The Budd-Vannimenus theorem is modified to apply to superconductors in the Meissner state. The obtained identity links the surface value of the electrostatic potential to the density of free energy at the surface which allows one to evaluate the electrostatic potential observed via the capacitive pickup without the explicit solution of the charge profile.Comment: 7 pages, 1 figur

    Strategies for Automated Control of the Bioproduction of Mcl-PHA Biopolymers

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    Medium-chain-length polyhydroxyalkanoates (mcl-PHAs) are polyesters synthesized by numerous bacteria as storage material. Despite being promising candidates for biodegradable materials of industrial interest and environmental value, their usage is still rather limited because of high production costs. One of the areas with considerable potential for further improvements is control of the production process. This paper deals with the experimental work related to the design of control strategies for mcl-PHA biopolymer production process (Pseudomonas putida KT2442 fed-batch cultivations). For this bioprocess, a set of five control strategies (two main and three auxiliary strategies) have been proposed, together with the proper sequence of their switching during the fedbatch part of the production process. The application of these strategies with octanoic acid as a sole carbon source resulted in intracellular PHA content (max. mass fraction 65 % of mcl-PHA in cell dry mass (g g–1) and PHA productivity (max. 0.89 g L–1 h–1) comparable to the best results reported in the literature for this type of strain and carbon substrate. This work is licensed under a Creative Commons Attribution 4.0 International License

    KK^- - nucleus relativistic mean field potentials consistent with kaonic atoms

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    KK^- atomic data are used to test several models of the KK^- nucleus interaction. The t(ρ\rho)ρ\rho optical potential, due to coupled channel models incorporating the Λ\Lambda(1405) dynamics, fails to reproduce these data. A standard relativistic mean field (RMF) potential, disregarding the Λ\Lambda(1405) dynamics at low densities, also fails. The only successful model is a hybrid of a theoretically motivated RMF approach in the nuclear interior and a completely phenomenological density dependent potential, which respects the low density theorem in the nuclear surface region. This best-fit KK^- optical potential is found to be strongly attractive, with a depth of 180 \pm 20 MeV at the nuclear interior, in agreement with previous phenomenological analyses.Comment: revised, Phys. Rev. C in pres

    Adaptive Control of Saccharomyces cerevisiae Yeasts Fed-Batch Cultivations

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    In this paper, the application of an adaptive algorithm for control of fed-batch bioprocess capable of coping with time-variant process properties in the presence of uncertainties is introduced. The proposed adaptive controller uses Maršík’s heuristic algorithm for adaptation based on control error oscillation rate criterion without the need of a mathematical model of the controlled process or any special test signals. The intended application of the resulting controller was off-gas CO2 concentration control in fed-batch yeast cultivations where the set point has the form of a time-varying concentration profile. The controller has been tested in a series of experimental fed-batch cultivations with D7 Saccharomyces cerevisiae strain, a UV mutant suitable for ergosterol production, in 7‑litre laboratory bioreactor. Obtained results demonstrate good properties of this adaptive controller that can be used without the need for a tedious parameter identification of the complex bioprocess

    Discontinuity of capacitance at the onset of surface superconductivity

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    The effect of the magnetic field on a capacitor with a superconducting electrode is studied within the Ginzburg-Landau approach. It is shown that the capacitance has a discontinuity at the onset of the surface superconductivity Bc3B_{\rm c3} which is expressed as a discontinuity in the penetration depth of the electric field into metals. Estimates show that this discontinuity is observable with recent bridges for both conventional and high-TcT_{\rm c} superconductors of the type-II

    Heavy Metal Contamination of the Loučka River Water Ecosystem

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    Heavy metal contamination of the Loučka River water ecosystem was assessed in July 2005. We analyzed concentrations of T-Hg (total mercury), Cd, Pb, Cr, Cu, Zn, and Ni in water, sediments, zoobenthos, and in the brown trout (Salmo trutta m. fario) muscle and liver tissues (a total of 28 individuals) at four sampling sites. The highest Pb and Ni concentrations (4.634-12.050 and 0.689-24.980 mg kg-1) were found in sediments. The zoobenthos was most contaminated by Zn and Cu (0.556-1.505 and 2.925-74.300 mg kg-1). The heavy metal contamination of river water was highest in Ni and Cr (0.1-6.8 and 0.5-10.0 mg l-1). Concentrations of heavy metals in the brown trout muscle were following (in mg kg-1): Pb 0.108 ± 0.073 - 1.010 ± 0.506, Cd 0.003 ± 0.002 - 0.026 ± 0.022, Zn 3.956 ± 0.371 - 5.801 ± 1.718, Ni 0.058 ± 0.018 - 0.102 ± 0.046, Cr 0.028 ± 0.005 - 0.073 ± 0.039, Cu 0.329 ± 0.079 - 0.437 ± 0.064 and Hg 0.065 ± 0.008 - 0.106 ± 0.047. Statistical differences (P -1). Humans of 60 kg body mass may consume 1.5 kg of brown trout muscle from the Loučka River weekly without any risk. Adverse influence of the Uniglas distillery on the Loučka River environment contamination by heavy metals was not confirmed
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