RESUMEN
The Light Ion Detector for ALTEA (LIDAL) is a new instrument designed to measure flux, energy spectra and Time of Flight of ions in a space habitat. It was installed in the International Space Station (Columbus) on January 19, 2020 and it is still operating. This paper presents the results of LIDAL measurements in the first 17 months of operation (01/2020-05/2022). Particle flux, dose rate, Time of Flight and spectra are presented and studied in the three ISS orthogonal directions and in the different geomagnetic regions (high latitude, low latitude, and South Atlantic Anomaly, SAA). The results are consistent with previous measurements. Dose rates range between 1.8 nGy/s and 2.4 nGy/s, flux between 0.21 particles/(sr cm2 s) and 0.32 particles/(sr cm2 s) as measured across time and directions during the full orbit. These data offer insights concerning the radiation measurements in the ISS and demonstrate the capabilities of LIDAL as a unique tool for the measurement of space radiation in space habitats, also providing novel information relevant to assess radiation risks for astronauts.
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Radiación Cósmica , Monitoreo de Radiación , Vuelo Espacial , Nave Espacial , Actividad Solar , Monitoreo de Radiación/métodos , Dosis de Radiación , IonesRESUMEN
Proton radioactivity was discovered exactly 50 years ago. First, this nuclear decay mode sets the limit of existence on the nuclear landscape on the neutron-deficient side. Second, it comprises fundamental aspects of both quantum tunnelling as well as the coupling of (quasi)bound quantum states with the continuum in mesoscopic systems such as the atomic nucleus. Theoretical approaches can start either from bound-state nuclear shell-model theory or from resonance scattering. Thus, proton-radioactivity guides merging these types of theoretical approaches, which is of broader relevance for any few-body quantum system. Here, we report experimental measurements of proton-emission branches from an isomeric state in 54mNi, which were visualized in four dimensions in a newly developed detector. We show that these decays, which carry an unusually high angular momentum, â = 5 and â = 7, respectively, can be approximated theoretically with a potential model for the proton barrier penetration and a shell-model calculation for the overlap of the initial and final wave functions.
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In this study a volatolomic approach is proposed for the characterization of the volatile organic compound (VOC) composition of essential oils (EOs) extracted from common aromatic plants. Five species (Prunus spinosa L., Salvia officinalis L., Eucalyptus globulus L., Melissa officinalis L. and Mentha x piperita L.), particularly widespread in Southern Italy, were selected as recognized sources of natural bioactive compounds with beneficial properties. Hydro distillation and solid-liquid extraction with ethanol at different percentages were used to obtain EOs, and their extraction capabilities were compared analyzing chromatographic profiles obtained by headspace solid-phase microextraction (HS-SPME) coupled with gas chromatography - mass spectrometry (GC-MS). The analytical procedure was optimized in term of SPME fiber, adsorption time and desorption time. GC-MS analyses were performed allowing the profiling of the VOC fingerprint in each plant extract. Experimental data were processed by a statistical multivariate approach (Analysis of Variance and Principal Component Analysis obtained for compounds and chemical classes), confirming that EO aroma profiles were statistically different for each of the selected five plants. The proposed volatolomic approach has proved to be an easy and efficient tool to study the aroma profile, allowing the collection of specific information and opening new perspectives and opportunities for the detection and identification of VOCs in agricultural and ecological applications.
Asunto(s)
Eucalyptus , Melissa , Aceites Volátiles , Prunus , Salvia officinalis , Italia , Mentha piperita , Microextracción en Fase SólidaRESUMEN
The isospin mixing was deduced in the compound nucleus ^{80}Zr at an excitation energy of E^{*}=54 MeV from the γ decay of the giant dipole resonance. The reaction ^{40}Ca+^{40}Ca at E_{beam}=136 MeV was used to form the compound nucleus in the isospin I=0 channel, while the reaction ^{37}Cl+^{44}Ca at E_{beam}=95 MeV was used as the reference reaction. The γ rays were detected with the AGATA demonstrator array coupled with LaBr_{3}:Ce detectors. The temperature dependence of the isospin mixing was obtained and the zero-temperature value deduced. The isospin-symmetry-breaking correction δ_{C} used for the Fermi superallowed transitions was extracted and found to be consistent with ß-decay data.