•Heavy metals partitioning between consecutive stages of ESP has been compared for different coals.•The concentration of heavy metals in fly ashes from Polish coals is at a level similar to mean ...values from other coals.•The concentration of heavy metals increased in fly ash from the consecutive fields of ESP.•The concentration of heavy metals correlates with decreasing mean size of precipitated particles.•Heavy metals are mainly retained in the finest particles of fly ash due to their deposition on the particle surface.
The paper presents experimental studies of heavy metals partitioning in fly ash particles after combustion of various types of coal (lignite, sub-bituminous, bituminous, and anthracite) between different fields of electrostatic precipitator. The concentration of the following heavy metals has been measured: Ba, Sr, Zn, Cu, Ni, Cr, As, Co, Pb. The results show that the concentration of heavy metals is higher in small particles (<1μm) than in larger ones that correlates with consecutive fields of electrostatic precipitator. This relation is independent of the type of combusted coal, although differences in the values of concentrations of individual elements exist. Better knowledge on heavy metal partitioning in the combustion-precipitation system is needed for the development of emission control devices of higher efficiency, such as electrostatic agglomerators or hybrid filters, particularly for PM1 particles. The results of these investigations can also be helpful in the designing of novel physical and chemical processes for recovery selected trace elements from fly ash, for their further utilization.
The first 2+ and 3- states of the doubly magic nucleus 132Sn are populated via safe Coulomb excitation employing the recently commissioned HIE-ISOLDE accelerator at CERN in conjunction with the ...highly efficient MINIBALL array. The 132Sn ions are accelerated to an energy of 5.49 MeV / nucleon and impinged on a 206Pb target. Deexciting γ rays from the low-lying excited states of the target and the projectile are recorded in coincidence with scattered particles. The reduced transition strengths are determined for the transitions 0g.s.+→21+, 0g.s.+→31-, and 21+→31- in 132Sn. The results on these states provide crucial information on cross-shell configurations which are determined within large-scale shell-model and Monte Carlo shell-model calculations as well as from random-phase approximation and relativistic random-phase approximation. The locally enhanced B(E2;0g.s.+→21+) strength is consistent with the microscopic description of the structure of the respective states within all theoretical approaches. The presented results of experiment and theory can be considered to be the first direct verification of the sphericity and double magicity of 132Sn.
The aim of this study was to compare the utility of BACTEC™ Mycosis-IC/F (Mycosis), BACTEC™ Plus Aerobic/F (Aerobic), and BACTEC™ Plus Anaerobic/F (Anaerobic) media in the detection of fungi from ...simulated (obtained by the inoculation of tested media first with sterile sheep’s blood and subsequently with one of 60 clinical yeast isolates) and clinical blood samples, taken during routine diagnostic examination in two hospitals. All tested strains grew on Mycosis as well as Aerobic bottles, and the time to detection obtained for Mycosis was significantly shorter (
p
< 0.05). The largest differences in the time to positivity was found for
Candida glabrata
and
Cryptococcus neoformans
, when Mycosis preceded Aerobic in 20–48 h (mean 35.5 h) and 0.7–64 h (mean 24 h), respectively. On the contrary,
C. krusei
were detected earlier in Aerobic media. In clinical samples, the detection of
C. glabrata
was also significantly faster in Mycosis than in Aerobic (29.22 ± 11.48 h compared to 86 ± 40 h). The media complement each other and, in 45 % of clinical examination sets, a single positive medium was noted (25 % in Mycosis and 19 % in Aerobic). The study proved that both Aerobic and Mycosis media serve as the correct condition for the culture of fungi and that they varied significantly in the detection time of clinically important species. This result could suggest that the simultaneous use of Aerobic as well as Mycosis media may improve the time of diagnosis in many patients, especially those infected with
C. glabrata
or
C. neoformans
.
There is sparse direct experimental evidence that atomic nuclei can exhibit stable "pear" shapes arising from strong octupole correlations. In order to investigate the nature of octupole collectivity ...in radium isotopes, electric octupole (E3) matrix elements have been determined for transitions in ^{222,228}Ra nuclei using the method of sub-barrier, multistep Coulomb excitation. Beams of the radioactive radium isotopes were provided by the HIE-ISOLDE facility at CERN. The observed pattern of E3 matrix elements for different nuclear transitions is explained by describing ^{222}Ra as pear shaped with stable octupole deformation, while ^{228}Ra behaves like an octupole vibrator.
.
A bismuth-germanate (BGO) escape-suppression shield for the high-purity germanium triple-cluster detector of the MINIBALL
γ
-ray spectrometer was designed and built. Monte Carlo simulations with ...the simulation code GEANT4 were performed to guide the construction and to determine the detector geometry of the new BGO shield. After the first measurements concerning mechanical properties of the BGO housing and the performance of the photomultiplier tubes at the Institut de Physique Nucléaire, Orsay, the prototype BGO escape-suppression shield was combined with a MINIBALL triple-cluster detector at the Institut für Kernphysik, Cologne. A dedicated electronics and digital data-acquisition system was put into operation in order to determine timing properties of the combined coincidence measurement and to measure values for the energy resolution of the BGO detectors, for the BGO low-energy threshold, and for the crucial peak-to-total ratio (P/T). The measured P/T value for a standard
60
Co
γ
-ray source compares well with expectations and will allow to proceed with the amendment of the MINIBALL triple-cluster detectors with an escape-suppression shield for improved in-beam
γ
-ray spectroscopy especially at the new HIE-ISOLDE accelerator for radioactive ion beams at CERN.
Lifetimes of the 21+ states in 44Ti, 48,50Cr, and 52Fe were determined with high accuracy exploiting the recoil distance Doppler-shift method. The reduced E2 transition strengths of 44Ti and 52Fe ...differ considerably from previously known values. A systematic increase in collectivity is found for the N=Z nuclei compared to neighboring isotopes. The B(E2) values along the Ti, Cr, and Fe isotopic chains are compared to shell-model calculations employing established interactions for the 0f1p shell, as well as a novel effective shell-model Hamiltonian starting from a realistic nucleon–nucleon potential. The theoretical approaches underestimate the B(E2) values for the lower-mass Ti isotopes. Strong indication is found for particle-hole cross-shell configurations, recently corroborated by similar results for the neighboring isotone 42Ca.
Lifetimes of the 21+ states in 44Ti, 48,50Cr, and 52Fe were determined with high accuracy exploiting the recoil distance Doppler-shift method. The reduced E2 transition strengths of 44Ti and 52 Fe ...differ considerably from previously known values. A systematic increase in collectivity is found for the N = Z nuclei compared to neighboring isotopes. The B(E2) values along the Ti, Cr, and Fe isotopic chains are compared to shell-model calculations employing established interactions for the 0f 1p shell, as well as a novel effective shell-model Hamiltonian starting from a realistic nucleon-nucleon potential. The theoretical approaches underestimate the B(E2) values for the lower-mass Ti isotopes. Strong indication is found for particle-hole cross-shell configurations, recently corroborated by similar results for the neighboring isotone 42 Ca. A detailed manuscript has meanwhile been published in Physics Letters B 1.
The first 2^{+} and 3^{-} states of the doubly magic nucleus ^{132}Sn are populated via safe Coulomb excitation employing the recently commissioned HIE-ISOLDE accelerator at CERN in conjunction with ...the highly efficient MINIBALL array. The ^{132}Sn ions are accelerated to an energy of 5.49 MeV/nucleon and impinged on a ^{206}Pb target. Deexciting γ rays from the low-lying excited states of the target and the projectile are recorded in coincidence with scattered particles. The reduced transition strengths are determined for the transitions 0_{g.s.}^{+}→2_{1}^{+}, 0_{g.s.}^{+}→3_{1}^{-}, and 2_{1}^{+}→3_{1}^{-} in ^{132}Sn. The results on these states provide crucial information on cross-shell configurations which are determined within large-scale shell-model and Monte Carlo shell-model calculations as well as from random-phase approximation and relativistic random-phase approximation. The locally enhanced B(E2;0_{g.s.}^{+}→2_{1}^{+}) strength is consistent with the microscopic description of the structure of the respective states within all theoretical approaches. The presented results of experiment and theory can be considered to be the first direct verification of the sphericity and double magicity of ^{132}Sn.
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