Search results for "absorption"
showing 10 items of 2701 documents
Experimental study of 100Tc β decay with total absorption γ -ray spectroscopy
2017
The β decay of 100Tc has been studied by using the total absorption γ -ray spectroscopy technique at the Ion Guide Isotope Separator On-Line facility in Jyväskylä. In this work the new Decay Total Absorption γ -ray Spectrometer in coincidence with a cylindrical plastic β detector has been employed. The β intensity to the ground state obtained from the analysis is in good agreement with previous high-resolution measurements. However, differences in the feeding to the first-excited state as well as weak feeding to a new level at high excitation energy have been deduced from this experiment. Theoretical calculations performed in the quasiparticle random-phase approximation framework are also r…
r Process (n, γ) Rate Constraints from the γ Emission of Neutron Unbound States in β decay
2017
Total absorption gamma-ray spectroscopy is used to measure accurately the intensity of γγ emission from neutron-unbound states populated in the ββ-decay of delayed-neutron emitters. From the comparison of this intensity with the intensity of neutron emission a constraint on the (n, γγ) cross section for highly unstable neutron-rich nuclei can be deduced. A surprisingly large γγ branching was observed for a number of isotopes which might indicate the need to increase by a large factor the Hauser-Feshbach (n, γγ) cross-section estimates that impact on r process abundance calculations. peerReviewed
Total absorption spectroscopy study of the β decay of 86Br and 91Rb
2017
The beta decays of 86Br and 91Rb have been studied using the total absorption spectroscopy technique. The radioactive nuclei were produced at the Ion Guide Isotope Separator On-Line facility in Jyväskylä and further purified using the JYFLTRAP. 86Br and 91Rb are considered to be major contributors to the decay heat in reactors. In addition, 91Rb was used as a normalization point in direct measurements of mean gamma energies released in the beta decay of fission products by Rudstam et al. assuming that this decay was well known from high-resolution measurements. Our results show that both decays were suffering from the Pandemonium effect and that the results of Rudstam et al. should be renor…
Total absorption γ-ray spectroscopy of the β-delayed neutron emitters 87Br, 88Br, and 94Rb
2017
We investigate the decay of 87,88Br and 94Rb using total absorption γ -ray spectroscopy. These important fission products are β-delayed neutron emitters. Our data show considerable βγ intensity, so far unobserved in high-resolution γ -ray spectroscopy, from states at high excitation energy. We also find significant differences with the β intensity that can be deduced from existing measurements of the β spectrum. We evaluate the impact of the present data on reactor decay heat using summation calculations. Although the effect is relatively small it helps to reduce the discrepancy between calculations and integral measurements of the photon component for 235U fission at cooling times in the r…
The Ti-influence on the tourmaline color
2008
Titanium was examined in different black tourmalines by spectrophotometric analyses in the region between 12500 and 27000 cm-1 (800-370 nm) using a microscope spectrophotometer MPV-5P, Leitz (Germany), and chemically analyzed on an electron microprobe Camebax Microbeam, Cameca (France) in WDS Mode. Fourteen tourmaline samples with their face oriented parallel to the principal axis, cut and polished down to thin sections, showed polarized spectra of two broad absorption bands at approximately 14000 cm-1 (715 nm) and 24000 cm-1 (417 nm). Precision thickness measurements were used to calculate the absorption coefficients α. For the absorption around 24000 cm-1, a linear correlation was observe…
Comparison of impact characteristics of different ice hockey arena dasher boards
2012
During last years the incidence and severity of ice hockey related concussions have been increased and, hence, something should be done to stop this growth. The main aim of this study was to find out how dasher board materials and structures affect impact characteristics and, thereby, the risk of concussions. The measurements were divided into two parts; in the first part, the physiological characteristics of body checks were determined in real game measurements, and the second part, consisted of simulation of body checks in the laboratory. High speed cameras and accelerometers were used to collect data. More flexible protective shielding material (dasher board B) resulted in lower peak for…
Lidar detection of carbon dioxide in volcanic plumes
2015
Volcanic gases give information on magmatic processes. In particular, anomalous releases of carbon dioxide precede volcanic eruptions. Up to now, this gas has been measured in volcanic plumes with conventional measurements that imply the severe risks of local sampling and can last many hours. For these reasons and for the great advantages of laser sensing, the thorough development of volcanic lidar has been undertaken at the Diagnostics and Metrology Laboratory (UTAPRAD-DIM) of the Italian National Agency for New Technologies, Energy and Sustainable Economic Development (ENEA). In fact, lidar profiling allows one to scan remotely volcanic plumes in a fast and continuous way, and with high s…
Volcanic Plume CO2 Flux Measurements at Mount Etna by Mobile Differential Absorption Lidar
2017
Volcanic eruptions are often preceded by precursory increases in the volcanic carbon dioxide (CO2) flux. Unfortunately, the traditional techniques used to measure volcanic CO2 require near-vent, in situ plume measurements that are potentially hazardous for operators and expose instruments to extreme conditions. To overcome these limitations, the project BRIDGE (BRIDging the gap between Gas Emissions and geophysical observations at active volcanoes) received funding from the European Research Council, with the objective to develop a new generation of volcanic gas sensing instruments, including a novel DIAL-Lidar (Differential Absorption Light Detection and Ranging) for remote (e.g., distal) …
The Effect of Emotional Dissonance and Mental Load on Need for Recovery and Work Engagement among Italian Fixed-Term Researchers
2020
Although many studies have been conducted to evaluate the risk and protective factors on psychological health among academic staff, little attention has been paid to fixed-term researchers, the weakest figures in the academic context. By using the Job Demands&ndash
Zanieczyszczenie metalami ciężkimi Matricaria chamomilla L. i Plantago lanceolata L
2019
Celem badań była ocena zanieczyszczenia metalami ciężkimi (Mn, Fe, Ni, Cu, Zn, Cd i Pb) rumianku lekarskiego (Matricaria chamomilla L.) i babki lancetowatej (Plantago lanceolata L.). W ramach biomonitoringu pasywnego pobrano próbki roślin leczniczych oraz próbki gleby, na której rosły rośliny. Metale ciężkie oznaczono za pomocą absorpcyjnej spektrometrii atomowej (AAS). Na podstawie przeprowadzonych badań można stwierdzić, że zioła wykorzystane do badań różniły się pod względem stężeń metali ciężkich w zależności od miejsca ich pobierania. Wszystkie próbki ziół były zanieczyszczone wysokimi stężeniami manganu, żelaza oraz cynku. Badane próbki gleb z grupy B i C według rozporządzenia ministr…