Collective and broken pair states of 65,67Ga

Excited states of 65Ga and 67Ga nuclei were populated through the 12C(58Ni,αp) and 12C(58Ni,3p) reactions, respectively, and investigated by in-beam γ-ray spectroscopic methods. The NORDBALL array equipped with a charged particle ball and 11 neutron detectors was used to detect the evaporated particles and γ rays. The level schemes of 65,67Ga were constructed on the basis of γγ-coincidence relations up to 8.6 and 10 MeV excitation energy, and Iπ=27/2 and 33/2+ spin and parity, respectively. The structure of 65,67Ga nuclei was described in the interacting boson-fermion plus broken pair model, including quasiproton, quasiproton-two-quasineutron, and three-quasiproton fermion configurations in the boson-fermion basis states. Most of the states were assigned to quasiparticle + phonon and three quasiparticle configurations on the basis of their electromagnetic decay properties

High-spin structure and electromagnetic transition strengths in Cd-104

The recoil distance Doppler shift and Doppler shift attenuation techniques were employed to determine for the first time lifetimes of high spin states in Cd-104in the time range 0.3 ps less than equal to tau less than 1.2 ns. The new experimental results are discussed in the frame of the interacting boson plus broken pair model

Blind DFE with Parametric Entropy-Based Feedback

Abstract -This paper considers the blind decision feedback equalizer for quadrature amplitude modulation (QAM) systems and proposes the optimization method of parametric stochastic gradient algorithms particularly derived for its entropy-based feedback filter. The optimization method is based on the fact that the "slope" of applied parametric complex-valued nonlinearity can be adjusted to the unknown probability distribution of an input intersymbol interference to respond with a maximum entropy output. The parametric optimization is achieved for 16-, 32-and 64-QAM signals

Decision Feedback Blind Equalizer with Tap-Leaky Whitening for Stable Structure-Criterion Switching

The research presented in this paper improves the structure-criterion switching performance of the blind decision feedback equalizer (DFE) which eliminates error propagation effects by optimizing both the structure and the cost criterion. To conquer the complexity of the 64-QAM (quadrature amplitude modulated) signal constellation, the stochastic entropy-gradient algorithm is additionally regularized by the coefficient leaky term to avoid a coefficients norm overgrowth of the received signal whitener. Effectively, the leak of coefficients is employed to ensure a stable structure-criterion switching of DFE between blind and decision-directed operation modes. The optimization of the resulting whitening algorithm is achieved by means of two free, leaky and entropic, parameters which act in opposition to each other. Both, the influence of the 64-QAM signal on the feedback filter behavior and the parametric optimization of the whitening algorithm are analyzed through simulations

Photon albedo for water, concrete, and iron at normal incidence, and dependence on the thickness of reflecting material

Total number and angular albedo were calculated for commonly used shielding materials, water, concrete, and iron, for photons with initial energies from 10 keV up to 10 MeV and normal incident angle. Influence of material thickness on total number albedo was also investigated. Double differential albedo was determined from simulation of photon transport through materials by using PENELOPE and MCNP software. Backscattered photons were scored and grouped in equal intervals of energy and angle. Analytical expressions for angular and total number albedo as a function of initial energy were obtained. It was shown that angular albedo can be determined with the same formula for three examined materials. Corresponding analytical expressions for number albedo as a function of material thickness were presented in this paper. [Projekat Ministarstva nauke Republike Srbije, br. 171021

Further investigation of the repetitive failure in an aircraft engine cylinder head - mechanical properties of Aluminum alloy 242.0

© Bai et al. 2020 Open Access This article is distributed under the terms of the Creative Commons Attribution 4.0 International License Aluminum alloys are widely used in military and aviation industry due to their properties such as low density and high strength. During the aircraft operation there are mechanical failures of various structural components caused by numerous mechanisms such as corrosion, material defects, high cycle fatigue and the like. One of the frequent mechanical failures on air-cooled piston engines is the cylinder head cracking. This paper is the continuation a comprehensive research of the Lycoming IO-360-B1F aircraft cylinder head failure. The failure of this type has already occurred during flight and about 50 failures like this have been registered from around the world, some of them with a fatal outcome and therefore require detailed research. The paper consists of machining of the tested specimens and their testing at many different locations and in many different laboratories throughout Bosnia and Herzegovina, Serbia and Slovenia. This paper is based on a research that includes the experimental analysis of mechanical properties of Aluminum alloy 242.0 which is a constituent material of the cylinder head of the Lycoming IO-360-B1F aircraft engine on which a crack appeared. Based on chemical, metallographic, static and dynamic experimental tests of the material properties, Aluminum alloy 242.0 static and fatigue properties were obtained, S-N curve was formed and endurance limit was determined. Results of numerical simulations of experiments, confirmed by experimental results, were performed to make numerical procedures reliable due to further research. The results of the research are planned to be implemented in numerical modeling of the cylinder assembly stress-strain state under workload and in further numerical research of Lycoming IO-360-B1F cylinder assembly integrity assessment

Influence of mechanical activation on the structure of ultrafine BaTiO3 powders

The influence of mechanical activation in a planetary ball mill on the change of the structure of BaTiO3 powders has been investigated. The particle size distribution of the nonactivated and activated samples was measured by a particle dimension laser analyzer. The mercury porosimetry method has been applied for determination of the surface area of the samples, bulk density, specific pore volumes, total porosity and the pore size distributions. Formation of paramagnetic centers and the change of the IR active modes was investigated by EPR and IR measurements. Semi-quantitative comparison of the BaCO3 and OH- group presence in IR spectra was calculated. The investigation showed that mechanical activation of BaTiO3 has a pronounced influence on the change of the powder particles structure and enables establishing the directions of possible BaTiO3 ceramics materials properties prognosis according to the synthesis-structure correlation. (C) 2009 Elsevier B.V. All rights reserved

AMPHIPHILIC POLY(HYDROXYETHYLASPARTAMIDE) DERIVATIVE-BASED MICELLES AS DRUG DELIVERY SYSTEMS FOR FERULIC ACID

In this article, in order to obtain tetragonal nanocrystalline BaTiO3, structural investigations of mechanically activated BaTiO3 powder have been performed. A mercury porosimetry analysis and scanning electron microscopy method have been applied for determination of the specific pore volume, porosity and microstructure morphology of the samples. The lattice vibration spectra of nonactivated and activated powders, their phase composition, lattice microstrains and the mean size of coherently diffracting domains were examined by Raman spectroscopy and the X-ray powder diffraction method. The average crystal structure of obtained nanocrystalline powders, estimated from X-ray diffraction data, gave evidence of retained, but slightly sustained tetragonality of powders, even for particles as small as similar to 30 nm. Raman spectroscopy also gave clear evidence for local tetragonal symmetries, in particular through the presence of a band at similar to 307 cm(-1)

Effects of sulfur amino acids, sodium hydrogen sulfide and H2S in rats

Date: September 28-30, 2017, Pécs, Hungary