82 research outputs found
A gamma- and X-ray detector for cryogenic, high magnetic field applications
As part of an experiment to measure the spectrum of photons emitted in
beta-decay of the free neutron, we developed and operated a detector consisting
of 12 bismuth germanate (BGO) crystals coupled to avalanche photodiodes (APDs).
The detector was operated near liquid nitrogen temperature in the bore of a
superconducting magnet and registered photons with energies from 5 keV to 1000
keV. To enlarge the detection range, we also directly detected soft X-rays with
energies between 0.2 keV and 20 keV with three large area APDs. The
construction and operation of the detector is presented, as well as information
on operation of APDs at cryogenic temperatures
Performance of HPGe Detectors in High Magnetic Fields
A new generation of high-resolution hypernuclear gamma$-spectroscopy
experiments with high-purity germanium detectors (HPGe) are presently designed
at the FINUDA spectrometer at DAPhiNE, the Frascati phi-factory, and at PANDA,
the antiproton proton hadron spectrometer at the future FAIR facility. Both,
the FINUDA and PANDA spectrometers are built around the target region covering
a large solid angle. To maximise the detection efficiency the HPGe detectors
have to be located near the target, and therefore they have to be operated in
strong magnetic fields B ~ 1 T. The performance of HPGe detectors in such an
environment has not been well investigated so far. In the present work VEGA and
EUROBALL Cluster HPGe detectors were tested in the field provided by the ALADiN
magnet at GSI. No significant degradation of the energy resolution was found,
and a change in the rise time distribution of the pulses from preamplifiers was
observed. A correlation between rise time and pulse height was observed and is
used to correct the measured energy, recovering the energy resolution almost
completely. Moreover, no problems in the electronics due to the magnetic field
were observed.Comment: submitted to Nucl. Instrum. Meth. Phys. Res. A, LaTeX, 19 pages, 9
figure
Nuclear structure of Ac-231
The low-energy structure of 231Ac has been investigated by means of gamma ray
spectroscopy following the beta-decay of 231Ra. Multipolarities of 28
transitions have been established by measuring conversion electrons with a
mini-orange electron spectrometer. The decay scheme of 231Ra --> 231Ac has been
constructed for the first time. The Advanced Time Delayed beta-gamma-gamma(t)
method has been used to measure the half-lives of five levels. The moderately
fast B(E1) transition rates derived suggest that the octupole effects, albeit
weak, are still present in this exotic nucleus
On proportionality of the light output of semiconductor scintillators under irradiation by alpha-particles and heavy ions
In the energy range E =2.8...42.2 MeV, the light output S was measured for ZnSe-based scintillators under irradiation with α-
particles and heavy ions 81Br. Under such irradiation, the proportionality S(Еα,i) is observed up to energies Еα≤7 MeV. Substantial
deviation from linearity in the region of higher energies is explained by different contribution to S from both primary and δ-electrons. Increases were also observed in the values of intrinsic energy resolution with shorter shaping time constants.Виміряно світловий вихід S для сцинтиляторів, заснованих на ZnSe, при опроміненні α-частками і
важкими іонами 81Br у діапазоні енергій E =2.8...42.2 МеВ. При опроміненні спостерігалася пропорційність S(Е
α
,i) до енергій Еα ≤7 МеВ. Істотне відхилення від лінійності в області більш високих енергій пояснюється
різним внеском у S як первинних, так і δ-електронів. Помітний вплив на криву пропорційності і спектри енергії
робило легування Te.Измерен световой выход S для сцинтилляторов, основанных на ZnSe, при облучении α-частицами и тяжелыми ионами 81Br в диапазоне энергий E=2.8...42.2 МэВ. При облучении наблюдалась пропорциональность S(Еα,i) до энергий Еα ≤7 МэВ. Существенное отклонение от линейности в области более высоких энергий объясняется различным вкладом в S как первичных, так и и δ-электронов. Заметное влияние на кривую пропорциональности и спектры энергии оказывало легирование Te
Forest as Stronghold of Local Ecological Practice: Currently Used Wild Food Plants in Polesia, Northern Ukraine
Local ecological practice (LEP, e.g., the everyday practice of collecting and using plants, including wild food plants) is shaped by nature (available local resources) and culture (local perceptions and knowledge on their usability), including a multitude of factors, among which language and geographical or cultural separation have been found to play crucial roles in affecting biocultural diversity. Also, proximity to the forest has been shown to increase the use of plants. We conducted ethnobotanical fieldwork within eastern and western regions of Ukrainian Polesia, during which we interviewed 118 people. Through semi-structured interviews, we recorded the distribution of the current uses of 70 wild food taxa. The analysis of use records revealed homogeneous distribution of use despite the geographical distance and different spoken dialects; however, we were able to single out the highly sylvan region of eastern Polesia as the area with highest biocultural diversity for the use of wild food plants. The results suggest that in the context of the overall homogenization of local ecological knowledge, the continued existence of unintended contact with nature through living and working in the forest may be the primary factor maintaining the broader LEP in the sylvan area of eastern Polesia. Місцева екологічна практика (MЕП, що включає повсякденну практику збору та використання дикорослих рослин у їжу) формується природою (місцевими ресурсами) та культурою (місцеві знання про їх використання), що включає безліч чинників, серед яких мова та географічне або культурне відокремлення відіграють вирішальну роль у впливі на біокультурне різноманіття. Також показано, що близькість до лісу збільшує використання рослин. Ми проводили етноботанічні польові роботи у двох областях Українського Полісся, в ході яких ми провели інтерв’ю з 118 людьми. За допомогою напівструктурованих інтерв’ю ми задокументували поточне використання 70 таксонів дикорослих рослин у їжу. Аналіз записів про вживання свідчить про однорідний розподіл використання, незважаючи на географічне розташування та різні розмовні діалекти; однак, ми змогли виділити лісистий регіон Східного Полісся як територію з найвищим біокультурним різноманіттям використання дикорослих рослин уїжу. Результати свідчать, що в контексті загальної гомогенізації місцевих екологічних знань, продовження існування контакту з природою живучи та працюючи в лісі може бути основним чинником, який підтримує ширшу MЕПу в лісовій зоні Східного Полісся
Archival data on wild food plants used in Poland in 1948
<p>Abstract</p> <p>Background</p> <p>In 1948, Professor Józef Gajek initiated a detailed census of the wild edible plants used in Poland. The questionnaires were collected by correspondents of the Polish Folklore Society in 95 localities throughout Poland. A major part of these archival materials, including a substantial collection of herbarium specimens, had not undergone thorough analysis prior to this study, which presents a quantitative analysis of this archival set of data.</p> <p>Methods</p> <p>Herbarium specimens were identified and a database was created.</p> <p>Results</p> <p>Ninety-eight taxa identified to genus or species level, including 71 botanical species, identified using herbarium specimens, were found. On average only 11 edible plant species per locality were listed, the longest list included 39 species. No correlation between latitude and the number of edible species was found, whereas there was small but significant correlation with the longitude. Fruits were the most frequently collected part of plants. Most plants were primarily collected by women and children. Children both helped parents to collect wild fruits and also ate many species raw, which were not consumed by adults, but had often been eaten in the past. Eighteen of the taxa had not been reported in a recent comprehensive review of edible plants of Poland. <it>Stratiotes aloides</it>, used as a famine vegetable in the Łódź region, has never been reported as edible in any ethnobotanical literature.</p> <p>Conclusion</p> <p>The results undermine the conclusions of a recent comprehensive review of edible plants of Poland, which stated that many more wild edible plants have been collected in the Carpathians than in lowland Poland. However such results were shown to be caused by the substantially larger number of ethnographic studies undertaken in the Carpathians. In fact, large numbers of edible plant species were collected in the mid-20<sup>th </sup>century in a few regions, particularly along the eastern border, in the Carpathians and in communities originating from the expanded Soviet Union, which had been resettled to the north-west of Poland in 1945.</p
NEDA—NEutron Detector Array
The NEutron Detector Array, NEDA, will form the next generation neutron detection system that has been designed to be operated in conjunction with γ-ray arrays, such as the tracking-array AGATA, to aid nuclear spectroscopy studies. NEDA has been designed to be a versatile device, with high-detection efficiency, excellent neutron-γ discrimination, and high rate capabilities. It will be employed in physics campaigns in order to maximise the scientific output, making use of the different stable and radioactive ion beams available in Europe. The first implementation of the neutron detector array NEDA with AGATA 1π was realised at GANIL. This manuscript reviews the various aspects of NEDA
Global potential energy surface for the O2 + N2 interaction. Applications to the collisional, spectroscopic, and thermodynamic properties of the complex
A detailed characterization of the interaction between the most abundant
molecules in air is important for the understanding of a variety of phenomena
in atmospherical science. A completely {\em ab initio} global potential energy
surface (PES) for the O + N interaction is
reported for the first time. It has been obtained with the symmetry-adapted
perturbation theory utilizing a density functional description of monomers
[SAPT(DFT)] extended to treat the interaction involving high-spin open-shell
complexes. The computed interaction energies of the complex are in a good
agreement with those obtained by using the spin-restricted coupled cluster
methodology with singles, doubles and noniterative triple excitations
[RCCSD(T)]. A spherical harmonics expansion containing a large number of terms
due to the anisotropy of the interaction has been built from the {\em ab
initio} data. The radial coefficients of the expansion are matched in the long
range with the analytical functions based on the recent {\em ab initio}
calculations of the electric properties of the monomers [M. Bartolomei et al.,
J. Comp. Chem., {\bf 32}, 279 (2011)]. The PES is tested against the second
virial coefficient data and the integral cross sections measured with
rotationally hot effusive beams, leading in both cases to a very good
agreement. The first bound states of the complex have been computed and
relevant spectroscopic features of the interacting complex are reported. A
comparison with a previous experimentally derived PES is also provided
Wild vascular plants gathered for consumption in the Polish countryside: a review
BACKGROUND: This paper is an ethnobotanical review of wild edible plants gathered for consumption from the end of the 18(th )century to the present day, within the present borders of Poland. METHODS: 42 ethnographic and botanical sources documenting the culinary use of wild plants were analyzed. RESULTS: The use of 112 species (3.7% of the flora) has been recorded. Only half of them have been used since the 1960s. Three species: Cirsium rivulare, Euphorbia peplus and Scirpus sylvaticus have never before been reported as edible by ethnobotanical literature. The list of wild edible plants which are still commonly gathered includes only two green vegetables (Rumex acetosa leaves for soups and Oxalis acetosella as children's snack), 15 folk species of fruits and seeds (Crataegus spp., Corylus avellana, Fagus sylvatica, Fragaria vesca, Malus domestica, Prunus spinosa, Pyrus spp., Rosa canina, Rubus idaeus, Rubus sect. Rubus, Sambucus nigra, Vaccinium myrtillus, V. oxycoccos, V. uliginosum, V. vitis-idaea) and four taxa used for seasoning or as preservatives (Armoracia rusticana root and leaves, Carum carvi seeds, Juniperus communis pseudo-fruits and Quercus spp. leaves). The use of other species is either forgotten or very rare. In the past, several species were used for food in times of scarcity, most commonly Chenopodium album, Urtica dioica, U. urens, Elymus repens, Oxalis acetosella and Cirsium spp., but now the use of wild plants is mainly restricted to raw consumption or making juices, jams, wines and other preserves. The history of the gradual disappearance of the original barszcz, Heracleum sphondylium soup, from Polish cuisine has been researched in detail and two, previously unpublished, instances of its use in the 20(th )century have been found in the Carpathians. An increase in the culinary use of some wild plants due to media publications can be observed. CONCLUSION: Poland can be characterized as a country where the traditions of culinary use of wild plants became impoverished very early, compared to some parts of southern Europe. The present use of wild plants, even among the oldest generation, has been almost entirely restricted to fruits
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