Search results for " Barrier"
showing 10 items of 540 documents
Multinucleon transfer reactions and proton transfer channels
2019
Transfer reactions have always been of great importance for nuclear structure and reaction mechanism studies. So far, in multinucleon transfer studies, proton pickup channels have been completely identified in atomic and mass numbers at energies close to the Coulomb barrier only in few cases. We measured the multinucleon transfer reactions in the 40Ar+208Pb system near the Coulomb barrier, by employing the PRISMA magnetic spectrometer. By using the most neutron-rich stable 40Ar beam we could populate, besidesneutron pickup and proton stripping channels, also neutron stripping and proton pickup channels. Comparison ofcross sections between different systems with the 208Pb target and with pro…
What determines a positive attitude towards natural food products? An expectancy theory approach.
2021
Natural food products are becoming increasingly popular worldwide due to their health and environmental benefits. However, these products' increasing anecdotal popularity has not translated into their widespread adoption; in fact, demand for natural food products remains confined to a relatively small segment of consumers. Despite this, little is known about the facilitators and inhibitors of favourable attitude of consumers towards these products. Recognising this gap, our study employed the theoretical lens of expectancy theory to investigate these factors. Through an extensive review of the pro-environmental consumption literature, we identified four facilitating and inhibiting factors: …
Success factors of Polish family businesses
2017
This article presents the results of a study carried out among family businesses operating in Poland. It is intended to supplement previously generated knowledge in the area of the operation of family businesses in the specific socio-economic and legal conditions in Poland. The objective was to collate the opinions of entrepreneurs regarding the need for visibility of the family and the family business status in business relations and the marketing activities of enterprises. The data were collected using in-depth interviews with the Polish family business owners. This paper outlines the conclusion of the study with respect to success factors such as: the trust among the family members, flex…
POGLĄDY NA NAUKĘ JĘZYKA OBCEGO U OSÓB Z WYSOKĄ I NISKĄ GOTOWOŚCIĄ KOMUNIKACYJNĄ W JĘZYKU ANGIELSKIM
2019
Reflection is understood as an activity which enables the reproduction of past experiences, reflection and meditation about them and their evaluation. One of the most significant features shaping learner reflection may be willingness to communicate in a foreign language – one’s volitional readiness to enter a communicative event in this language. In spite of a wealth of research conducted in this area, it is still unclear why some students are willing to start communication in a foreign language, while others are adamant to avoid it. For the purpose of this paper a qualitative-quantitative study was performed, focusing on four students with very low levels of willingness to communicate in E…
La evaluación de la sexualidad de las personas con discapacidad intelectual: construcción y descripción de una entrevista semiestructurada
2020
Si bien las personas con discapacidad intelectual experimentan la misma necesidad de intimidad que el resto, una serie de barreras sociales impiden la expresión de su sexualidad alentando a que se les perciba como seres asexuales. Por ello, durante mucho tiempo las voces de las personas con discapacidad no han sido escuchadas, lo que conlleva que actualmente exista una escasez de herramientas de evaluación para explorar los diferentes aspectos de la sexualidad de este colectivo teniendo en cuenta sus limitaciones en lectoescritura y comprensión. El objetivo de este estudio es la elaboración de una entrevista semiestructurada fiable y válida que contemple las características de las personas …
Stability and synthesis of superheavy elements: Fighting the battle against fission – example of $^{254}$No
2016
International audience; Superheavy nuclei exist solely due to quantum shell effects,which create a pocket in the potential-energy surface of the nucleus, thusproviding a barrier against spontaneous fission. Determining the height ofthe fission barrier and its angular-momentum dependence is important toquantify the role that microscopic shell corrections play in enhancing andextending the limits of nuclear stability. In this talk, the first measurement ofa fission barrier in the very heavy nucleus 254No will be presented.
Resonant activation in piecewise linear asymmetric potentials
2011
7 páginas, 8 figuras.-- PACS number(s): 05.40.−a, 05.45.−a, 02.50.Ey
P-Glycoprotein Influence on the Brain Uptake of a 5-HT2A Ligand: [18F]MH.MZ
2010
<i>Background/Aims:</i> The serotonergic system, especially the 5-HT<sub>2A</sub> receptor, is involved in various diseases and conditions. We have recently developed a new [<sup>18</sup>F]-5-HT<sub>2A</sub> receptor ligand using an analogue, MDL 100907, as a basis for molecular imaging with positron emission tomography. This tracer, [<sup>18</sup>F]MH.MZ, has been shown to be an adequate tool to visualize the 5-HT<sub>2A</sub> receptors in vivo. However, [<sup>18</sup>F]altanserin, similar in chemical structure, is a substrate of efflux transporters, such as P-glycoprotein (P-gp), of the blood-brain barrier…
Sedimentological and tectonic context of Paleoproterozoïque Franceville basin (Gabon) : fluid pressure structures, bitumen and uranium mineralization
2016
Metallogenic deposits within paleproterozoic basins depend on generation and migration of fluids. The aim of this study is to provide a better understanding of tectonic, sedimentological and diagenetic setting of the uranium deposits in the Franceville basin and to characterize hydraulic fracturing impact on fluid migration processes in sandstone reservoirs.Tectonic study define the N180-170° transfer faults, associated with Archean tectonic and the N110-120° longitudinal normal faults. These two fault directions split the Franceville basin into small sub-basins. The longitudinal normal faults are associated with footwall anticlines and hanging wall synclines. The uranium deposits of France…
Internal photoemission in solar blind AlGaN Schottky barrier photodiodes
2005
We have analyzed the photoresponse of solar blind AlGaN Schottky barrier photodiodes below the alloy band gap energy, in the 3.5-4.5 eV range, and we show that it is dominated by internal photoemission. The n-type Schottky barrier height is shown to increase linearly with the band gap energy of the AlGaN alloy. The amplitude of the internal photoemission signal is about 20 times smaller than the value given by the Fowler theory based on a free electron model. We explain this result by taking into account the interband transitions and the ballistic transport of photoexcited electrons in the metal. This low value of internal photoemission allows us to achieve a spectral rejection ratio betwee…