380 research outputs found
The Effect of Nuclear Rotation on the Collective Transport Coefficients
We have examined the influence of rotation on the potential energy and the
transport coefficients of the collective motion (friction and mass
coefficients). For axially symmetric deformation of nucleus Th-224 we have
found that at excitations corresponding to temperatures T > 1 MeV the shell
correction to the liquid drop energy practically does not depend on the angular
rotation. The friction and mass coefficients obtained within the linear
response theory for the same nucleus at temperatures larger than T=2 MeV are
rather stable with respect to rotation provided that the contributions from
spurious states arising due to the violation of rotation symmetry are removed.
At smaller excitations both friction and mass parameters corresponding to the
elongation mode are growing functions of rotational frequency.Comment: 16 pages, 5 eps figures, Latex, submitted to Nucl.Phys.
Time scales for fission at finite temperature
The concept of the "transient effect" is examined in respect of a "mean first
passage time". It is demonstrated that the time the fissioning system stays
inside the barrier is much larger than suggested by the transient time, and
that no enhancement of emission of neutrons over that given by Kramers' rate
formula ought to be considered.Comment: 6 pages, LaTex, 3 postscript figures; Keywords: Decay rate, transient
effect, mean first passage time; "Symposium on Nuclear Clusters",
Rauischholzhausen, Germany, 5-9 August 200
A Particle number conserving shell-correction method
The shell correction method is revisited. Contrary to the traditional
Strutinsky method, the shell energy is evaluated by an averaging over the
number of particles and not over the single-particle energies, which is more
consistent with the definition of the macroscopic energy. In addition, the
smooth background is subtracted before averaging the sum of single-particle
energies, which significantly improves the plateau condition and allows to
apply the method also for nuclei close to the proton or neutron drip lines. A
significant difference between the shell correction energy obtained with the
traditional and the new method is found in particular for highly degenerated
single-particle spectra (as i.e. in magic nuclei) while for deformed nuclei
(where the degeneracy is lifted to a large extent) both estimates are close,
except in the region of super or hyper-deformed states.Comment: 11 pages in LaTeX, 7 figure
The development of the infrastructure of outpatient-polyclinic institutions that provide cardiological aid and factors of their success
The purpose. To identify the key success factors in the development of the infrastructure of outpatient polyclinic institutions (OPPIs) that provide cardiac care. The conditions of their development based on the principles of public-private partnership (PPP) are taken into account. Materials and methods. The research was conducted according to the program based on general scientific methods of analysis, synthesis, generalization, interpretation of scientific data, as well as systemic and structural-functional approaches. Results. Significant problems in OPPIs that provide cardiac care infrastructure organization and management were identified. The data obtained showed the need to take measures for financing, organization of a high-tech production process, implementation of modern economic mechanisms in their work are necessary. This determined the search of mechanisms for the joint functioning of the state and business, the development of PPP in health care. The main mechanisms of PPP functioning were highlighted, namely organizational-legal, financial-investment, technical-organizational aspects. The benefits of cooperation for the state and the private partner are determined. A conceptual model of the key factors for achieving success in the development of OPPIs infrastructure based on PPP principles has been developed. Their role in the activities of OPPIs is indicated. Conclusions. The model of key factors for achieving success in the modernization of OPPIs infrastructure proposed in the article is a promising direction in the development of medical establishments that provide cardiac care. PPP is a promising direction in the development of the infrastructure of health care institutions in Ukraine
Method of Inverse Operator for the Recover Input Signal
There have been considered the methods of construction of the inverse operator for the restoration of signals in conditions of weak nonlinear dynamic and nonlinear static distortions in the registration devices and transmission of continuous signals are considered. The simplest structure of the implementation block of the inverse operator is based on the adder, whose second inverse communication competitor includes the simulation model of the direct operator. A linear inertia-free unit with a set transmission factor is used as regularizer.Розглянуто методи побудови оберненого оператора для відновлення сигналів при умовах слабких нелінійних динамічних і нелінійних статичних спотворень у пристроях реєстрації та передачі неперервних сигналів. Найпростіша структура блока реалізації оберненого оператора будується на основі накопичуваного суматора, у другий контур оберненого зв’язку якого включена імітаційна модель прямого оператора. В якості регуляризатора використано лінійний безінерційний блок із визначеним коефіцієнтом передачі
LEARNING TO WRITE IN AN ACADEMIC GENRE: ADULT ENGLISH LEARNERS’ USE OF SOCIOCULTURAL RESOURCES
In this multiple case study, I examined what types of sociocultural resources adult English learners brought with them from their previous contexts and what new resources they drew upon in the U.S. while learning to write in the essay genre. The study also identified how the participants chose to use previous and new sociocultural resources as mediated by the essay genre in the U.S. The following research foci shaped this study: (1) What types of sociocultural resources do adult English learners use while learning to write in the essay genre prior to and after their arrival in the U.S.? (2) How does the essay genre mediate adult English learners’ choices about sociocultural resources in the U.S.?
Data collection involved semi-structured interviews, in-class and out-of-class participant observations and collection of artifacts over a period of seven weeks. Six weeks were dedicated to essay writing in an English composition course and English workshop, and one week was used to conduct a final in-depth interview with each participant. Analysis of data included coding and theme analysis. Four refugee students with diverse cultural backgrounds and who had different contacts within the educational system in the U.S. participated in the study.
Results indicate that the participants relied upon seven categories of social, symbolic, and material resources when they learned to write in the essay genre. The categories are not mutually exclusive, but they do capture the variety of resources participants drew upon as writers in the essay genre prior to and after their arrival in the U.S. To draw upon their resources in the U.S., the participants also made choices that resulted in three types of actions. Those actions included losses, retentions, and gains. The essay genre mediated some retentions and gains. Those choices were driven by the essay genre demands of the participants’ new sociocultural context and, consequently, were rooted in their interaction within the new environment. Not all of the participants’ choices were mediated by the essay genre; some of them were shaped by contextual influences. Contextual influences shaped losses, as well as some of their retentions and gains. Those were general choices that were situated within particular contextual realities.
As my study shows, the essay genre along with context played a significant role in contributing to shaping participant’s agentive capacity. The essay genre, in particular, shaped the kind of competencies they had to demonstrate; contextual influences shaped the types of resources and their access to them. Understanding this interaction and, in particular, how genre helps students make purposeful choices and act as competent writers contributes to a more holistic understanding of learning to write as a sociocultural act. Implications for theory, research, and practice are discussed
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