In this Letter, we study the impact of the inclusion of the recently measured beta decay properties of the (102;104;105;106;107)Tc, (105)Mo, and (101)Nb nuclei in an updated calculation of the ...antineutrino energy spectra of the four fissible isotopes (235,238)U and (239,241)Pu. These actinides are the main contributors to the fission processes in pressurized water reactors. The beta feeding probabilities of the above-mentioned Tc, Mo, and Nb isotopes have been found to play a major role in the γ component of the decay heat of (239)Pu, solving a large part of the γ discrepancy in the 4-3000 s range. They have been measured by using the total absorption technique, insensitive to the pandemonium effect. The calculations are performed by using the information available nowadays in the nuclear databases, summing all the contributions of the beta decay branches of the fission products. Our results provide a new prediction of the antineutrino energy spectra of (235)U, (239,241)Pu, and, in particular, (238)U for which no measurement has been published yet. We conclude that new total absorption technique measurements are mandatory to improve the reliability of the predicted spectra.
•Multiferroic (NZF)-(100-x) wt.% BaTiO3 (BT) (x = 25, 50, 75) composites have been prepared;•Structural and electrical characterization has been done;•Correlation between composition, microstructure ...and electrical properties has been observed.
Multiferroics composite materials have been widely used in several applications, such as ceramic supercapacitors and multifunctional and active devices, owing to their high permittivity with ferroelectric and magnetic performance even at room temperature. The chosen preparation technique can be one of the most effective ways for obtaining multiferroic composite with different properties for the same composite. Here, multiferroic composite materials, (x) wt.% Ni0.5Zn0.5Fe2O4 (NZF)-(100-x) wt.% BaTiO3 (BT) (x = 25, 50, 75) were prepared by the co-precipitation synthesis route. The prepared multiferroic samples were characterized with various techniques like X-ray diffraction (XRD), scanning electron microscope (SEM), energy dispersive X-ray spectroscopy (EDXS), and vibrating sample magnetometer (VSM). The magnetic and AC electrical properties like conductivity, dielectric constant, dissipation factor (dielectric loss), and impedance spectroscopy analysis were studied in detail with different frequencies and temperatures. In our case, preparing nanosized NZF on or between microscale BT could enhance the electrical properties by decreasing the porosity (P) percentage, which reaches a low value for the sample x = 50 wt%, and increasing the conductivity. A relatively high dielectric constant (ε‘) at low frequencies and high temperatures was obtained, which is one of the main contributions in modern applications like a ceramic supercapacitor. Also, the studied samples show low dielectric loss (tanδ) values suggesting that it could be a contender for use in high-frequency microwave devices and tunable frequency filters.
Activity levels of the natural (
238
U,
232
Th,
226
Ra, and
40
K) and artificial (
137
Cs) radionuclides in surface soil samples collected from different areas of Libya, especially the southern and ...central provinces, including Valley Rwagh, which is in a mountainous region in Al-Jufra Oasis amid the Libyan desert, 600 km southeast of Tripoli, and in which there are stores of various weapons, were determined using a gamma-ray spectrometer with a HPGe detector. The average activity concentrations of
238
U,
232
Th,
226
Ra, and
40
K were measured as 87 ± 11, 202 ± 36, 121 ± 19, and 73 ± 3 Bq kg
-1
, respectively. The activity levels of artificial radionuclide
137
Cs measured in soil samples were below the detection limit. The average concentrations of radon in soil and air were estimated as 103 kBq m
-3
and 327 Bq m
-3
, respectively. The average values of outdoor absorbed gamma dose rate and the corresponding annual effective dose rate from external exposure, annual effective dose rate from inhalation of radon, and lifetime cancer risk estimated for assessing the radiological impacts caused by ionizing radiation emitted from these radionuclides on the population in the region were found to be 165 nGy h
-1
, 203 μSv y
-1
, 3096 μSv y
-1
, and 7 × 10
-4
, respectively.
The Double Chooz Experiment presents an indication of reactor electron antineutrino disappearance consistent with neutrino oscillations. A ratio of 0.944 ± 0.016 (stat) ± 0.040 (syst) observed to ...predicted events was obtained in 101 days of running at the Chooz Nuclear Power Plant in France, with two 4.25 GWth reactors. The results were obtained from a single 10 m3 fiducial volume detector located 1050 m from the two reactor cores. The reactor antineutrino flux prediction used the Bugey4 measurement as an anchor point. The deficit can be interpreted as an indication of a non-zero value of the still unmeasured neutrino mixing parameter sin 22θ13. Analyzing both the rate of the prompt positrons and their energy spectrum we find sin 22θ13 = 0.086 ± 0.041 (stat) ± 0.030 (syst), or, at 90% CL, 0.015 < sin 22θ13 < 0.16.
For the first time, we synthesized ultrasmall colloidal CuIn3Se5 quantum dots (QDs) with an average diameter of 3.5 nm and they were used to obtain nearly continuous ink-coated films by the ...hot-injection method. Copper chloride, indium chloride, and selenium were used as reagents in oleylamine as the solvent to synthesize CuIn3Se5 QDs without other organometallic precursors. The synthesized CuIn3Se5 QDs had a cubic crystal structure and they exhibited a strong quantum confinement effect according to their optical absorption spectra. The as-deposited and annealed thin films prepared from an ink solution containing these QDs exhibited p-type characteristics, a high band gap, and low surface roughness. The optical constants were determined by interference-free mathematical modeling for the as-deposited and annealed films obtained with the synthesized CuIn3Se5 QDs. Moreover, under 1 sun of simulated radiation, the photocurrent was greatly enhanced (>1000%) for the annealed CuIn3Se5 QD film compared with the as-deposited film. These results suggest that colloidal CuIn3Se5 QD films could potentially be used as an active layer in low-cost highly efficient Cu(In,Ga)Se/CdS thin film solar cells.
•First time synthesis of ultra-small CuIn3Se5 material in the quantum dots regime using solution-based method.•Ink-coated thin films prepared from these CuIn3Se5 quantum dots, have been made using controlled film applicator.•The coated CuIn3Se5 films display p-type character, low-surface roughness and strong photo-responsive behavior.
We assessed whether subitem scores on the Mini-Mental State Examination (MMSE) associated independently with cerebral white matter hyperintensity (WMH) and lacunar infarction (LI). Magnetic resonance ...imaging (MRI) and neuropsychological evaluation (MMSE) were performed in 1008 elderly individuals from the Ohasama Study (348 men, 660 women 65.5%; age 68.0 ± 6.0 mean ± SD years; MMSE score, 26.5 ± 2.9). The relationships between MRI findings and MMSE subitem scores were analyzed by logistic regression. Significant associations were observed between the MMSE subitems "Orientation to place" and WMH, and "Copy a figure" and LI. Pathological changes were detected by brain MRI associated with a decrease in cognitive function in healthy elderly individuals.
A
bstract
The Double Chooz experiment presents improved measurements of the neutrino mixing angle
θ
13
using the data collected in 467.90 live days from a detector positioned at an average distance ...of 1050 m from two reactor cores at the Chooz nuclear power plant. Several novel techniques have been developed to achieve significant reductions of the backgrounds and systematic uncertainties with respect to previous publications, whereas the efficiency of the
ν
¯
e
signal has increased. The value of
θ
13
is measured to be sin
2
2
θ
13
= 0.090
− 0.029
+ 0.032
from a fit to the observed energy spectrum. Deviations from the reactor
ν
¯
e
prediction observed above a prompt signal energy of 4 MeV and possible explanations are also reported. A consistent value of
θ
13
is obtained from a fit to the observed rate as a function of the reactor power independently of the spectrum shape and background estimation, demonstrating the robustness of the
θ
13
measurement despite the observed distortion.
Using 5326 days of atmospheric neutrino data, a search for atmospheric tau neutrino appearance has been performed in the Super-Kamiokande experiment. Super-Kamiokande measures the tau normalization ...to be 1.47±0.32 under the assumption of normal neutrino hierarchy, relative to the expectation of unity with neutrino oscillation. The result excludes the hypothesis of no-tau appearance with a significance level of 4.6σ. The inclusive charged-current tau neutrino cross section averaged by the tau neutrino flux at Super-Kamiokande is measured to be (0.94±0.20)×10−38 cm2. The measurement is consistent with the Standard Model prediction, agreeing to within 1.5σ.
We have searched for proton decays into a charged antilepton (e+, μ+) plus a meson (η, ρ0, ω) and for neutron decays into a charged antilepton (e+, μ+) plus a meson (π−, ρ−) using Super-Kamiokande ...I-IV data, corresponding to 0.316 megaton·years of exposure. This measurement updates the previous published result by using 2.26 times more data and improved analysis methods. No significant evidence for nucleon decay is observed and lower limits on the partial lifetime of the nucleon are obtained. The limits range from 3×1031 to 1×1034 years at 90% confidence level, depending on the decay mode.
This paper attempts to summarize the actual problematic of reactor antineutrino energy spectra in the frame of fundamental and applied neutrino physics. Nuclear physics is an important ingredient of ...reactor antineutrino experiments. These experiments are motivated by neutrino oscillations, i.e. the measure of the theta13 mixing angle. In 2011, after a new computation of the reactor antineutrino energy spectra, based on the conversion of integral data of the beta spectra from super(235)U, and super(239; 241)Pu, a deficit of reactor antineutrinos measured by short baseline experiments was pointed out. This is called the "reactor anomaly", a new puzzle in the neutrino physics area. Since then, numerous new experimental neutrino projects have emerged. In parallel, computations of the antineutrino spectra independant from the ILL data would be desirable. One possibility is the use of the summation method, summing all the contributions of the fission product beta decay branches that can be found in nuclear databases. Studies have shown that in order to obtain reliable summation antineutrino energy spectra, new nuclear physics measurements of selected fission product beta decay properties are required. In these proceedings, we will present the computation methods of reactor antineutrino energy spectra and the impact of recent beta decay measurements on summation method spectra. The link of these nuclear physics studies with short baseline line oscillation search will be drawn and new neutrino physics projects at research reactors will be briefly presented.
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