THE INFLUENCE OF A CUBIC DENSITY LAW ON PATTERNED GROUND FORMATION

1991 ◽  
Vol 01 (01) ◽  
pp. 27-39 ◽  
Author(s):  
G. McKAY ◽  
B. STRAUGHAN

A theoretical analysis is presented for the formation of polygonal ground which consists of stone borders forming regular hexagons with soil centers. The model is based on the onset of convection in a saturated soil below which is a cold permafrost layer. Darcy’s law is adopted with zero fluid inertia and the density is assumed constant except in the buoyancy term. In this term we take the equation of state proposed by Merker et al.,5 this being the one which assumes the density has a cubic dependence on temperature. Theoretical predictions of the model, particularly those for width to depth of the patterned ground cell are reported in detail.

Symmetry ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 1406
Author(s):  
Rémi Bougault ◽  
Bernard Borderie ◽  
Abdelouahad Chbihi ◽  
Quentin Fable ◽  
John David Frankland ◽  
...  

Correlations and clustering are of great importance in the study of the Nuclear Equation of State. Information on these items/aspects can be obtained using heavy-ion reactions which are described by dynamical theories. We propose a dataset that will be useful for improving the description of light cluster production in transport model approaches. The dataset combines published and new data and is presented in a form that allows direct comparison of the experiment with theoretical predictions. The dataset is ranging in bombarding energy from 32 to 1930 A MeV. In constructing this dataset, we put in evidence the existence of a change in the light cluster production mechanism that corresponds to a peak in deuteron production.


1975 ◽  
Vol 68 ◽  
pp. 239-241
Author(s):  
John C. Brown ◽  
H. F. Van Beek

SummaryThe importance and difficulties of determining the height of hard X-ray sources in the solar atmosphere, in order to distinguish source models, have been discussed by Brown and McClymont (1974) and also in this Symposium (Brown, 1975; Datlowe, 1975). Theoretical predictions of this height, h, range between and 105 km above the photosphere for different models (Brown and McClymont, 1974; McClymont and Brown, 1974). Equally diverse values have been inferred from observations of synchronous chromospheric EUV bursts (Kane and Donnelly, 1971) on the one hand and from apparently behind-the-limb events (e.g. Datlowe, 1975) on the other.


2012 ◽  
pp. 95-113
Author(s):  
Rita Biancheri

Up to now, in the traditional biomedical paradigm the terms "sex" and "gender" have either been used synonymously and the insertion of gender among the determining elements of conditions of wellbeing/disease has been difficult, and obstructed by disciplinary rigidities that retarded the acceptance of an approach which had already been largely found to be valid in other areas of research. The effected simplification demonstrated its limitations in describing the theme of health; but if, on the one hand, there has been a growing awareness of a subject which can in no way be considered "neutral", on the other hand there continues to be insufficient attention, both in theoretical analysis and in empirical research, given to female differences. The article is intended to support that the sick individual is a person, with his/her genetic heritage, his/her own cultural acquisitions and personal history, and own surrounding life context; but these and similar factors have not traditionally been taken into consideration by official medicine and welfare systems, despite a hoped-for socio-health integration.


Author(s):  
Agustina Malvido Perez Carletti ◽  
Markus Hanisch ◽  
Jens Rommel ◽  
Murray Fulton

AbstractIn this paper, we use a unique data set of the prices paid to farmers in Argentina for grapes to examine the prices paid by non-varietal wine processing cooperatives and investor-oriented firms (IOFs). Motivated by contrasting theoretical predictions of cooperative price effects generated by the yardstick of competition and property rights theories, we apply a multilevel regression model to identify price differences at the transaction level and the departmental level. On average, farmers selling to cooperatives receive a 3.4 % lower price than farmers selling to IOFs. However, we find cooperatives pay approximately 2.4 % more in departments where cooperatives have larger market shares. We suggest that the inability of cooperatives to pay a price equal to or greater than the one paid by IOFs can be explained by the market structure for non-varietal wine in Argentina. Specifically, there is evidence that cooperative members differ from other farmers in terms of size, assets and the cost of accessing the market. We conclude that the analysis of cooperative pricing cannot solely focus on the price differential between cooperatives and IOFs, but instead must consider other factors that are important to the members.


2018 ◽  
Vol 26 (6) ◽  
pp. 323-333
Author(s):  
Matt Grove

There is a growing interest in the relative benefits of the different social learning strategies used to transmit information between conspecifics and in the extent to which they require input from asocial learning. Two strategies in particular, conformist and payoff-based social learning, have been subject to considerable theoretical analysis, yet previous models have tended to examine their efficacy in relation to specific parameters or circumstances. This study employs individual-based simulations to derive the optimal proportion of individual learning that coexists with conformist and payoff-based strategies in populations experiencing wide-ranging variation in levels of environmental change, reproductive turnover, learning error and individual learning costs. Results demonstrate that conformity coexists with a greater proportion of asocial learning under all parameter combinations, and that payoff-based social learning is more adaptive in 97.43% of such combinations. These results are discussed in relation to the conjecture that the most successful social learning strategy will be the one that can persist with the lowest frequency of asocial learning, and the possibility that punishment of non-conformists may be required for conformity to confer adaptive benefits over payoff-based strategies in temporally heterogeneous environments.


2021 ◽  
Vol 12 (2) ◽  
Author(s):  
Oleksandr Malykhin ◽  
Nataliia Oleksandrivna Aristova ◽  
Liudmyla Kalinina ◽  
Tetyana Opaliuk

The present paper addresses the issue of determining the best international practices for developing soft skills among students of different specialties through carrying out a theoretical review. Basing on literature on present-day theory the authors make an attempt to explain soft skills dichotomies, summarize existing approaches to classifying soft skills, consolidate and document best international practices for soft skills development among potential employees of different specialties including bachelor students, master students, doctoral and postdoctoral students. The data obtained in the theoretical analysis reveal that the possible ambiguities in the interpretation of the concept of “soft skills” are caused, on the one hand, by the dichotomic perception of their nature by present-day researchers and educators and, on the other hand, by the absence of the common language which makes it difficult to provide a more unified definition most satisfactory to all concerned. The authors are convinced that soft skills have a cross-cutting nature and regard them as personal and interpersonal meta-qualities and meta-abilities that are vital to any potential employee who is going to make positive contributions not only to his/her professional development but to the development of a company he/she is going to work for. The results of the conducted theoretical review clearly indicate that the absence of the unified understanding of the concept of “soft skills” is reflected in the existence of different approaches to classifying soft skills, let alone, the selection of didactic tools for developing soft skills among potential employees.


2020 ◽  
pp. 36-40
Author(s):  
M. V. Ternova

The article analyzed concept of the study of art by Robin George Collingwood (1889-1943), a well-known English neo-hegelian philosopher. His significant part of the theoretical heritage is connected with the explanation of the nature of art and with the consideration of its condition during the period of the changing Oscar Wilde era to the era of Rudyard Kipling. The circle of problem such as content and form, character, image, mimesis, reflection, emotion, art and "street man" identified. All of them in Collingwood's presentation and interpretation significantly expanded the space of research not only English, but also European art criticism. The concept of study of art is "built" on the basis of an active understanding of historical and cultural traditions accented. The concept of art criticism of R.G. Collingwood – a famous English philosopher of the XIX-XX centuries, on the one hand, has self-importance, and on the other, although based on the traditions of contemporary humanities, still expands art history analysis of aesthetics through aesthetics and psychology. Recognizing the exhaustion of the English model of romanticism, R.G. Collingwood tries to outline the prospects for the development of art in the logic of the movement "romanticism – realism – avant-garde", which leads to the actualization of the problem of "mimesis – reflection". At the same time, the theorist's attention is consciously concentrated around the concept of "subject", the understanding of which is radically changing at the turn of the XIX-XX centuries. Theoretical material in the presentation of R.G. Collingwood is based on the work of Shakespeare, Reynolds, Turner, Cezanne, whose experience allows us to focus on the problem of "artist and audience". It is emphasized that Collingwood's position is ahead of its time, stimulating scientific research in the European humanities. The existence of indicative tendencies, which are distinguished in the logic of European cultural creation of the historical period, is emphasized.


2021 ◽  
pp. 58
Author(s):  
Grigory N. Utkin

The article reveals the conceptual, meaning-forming role of the categories of the unconditional and conditional in law. At the same time, their dialectical relationship with each other and with other categories is put in the center of attention. The dialectic of the unconditional and conditional is revealed by achieving the unity of the three stages of theoretical analysis, which allows us to present the unconditional and conditional, on the one hand, as the content of all concepts, through which the idea of law is generally expressed in various aspects and elements; on the other hand, the entire set of categories subject to dialectical analysis appears as elements of the content of the unconditional and conditional as semantic units that Express the universal characteristics of law in its features, isolation from other forms of social life.


Symmetry ◽  
2020 ◽  
Vol 12 (8) ◽  
pp. 1306
Author(s):  
Kirill Bronnikov ◽  
Vladimir Krechet ◽  
Vadim Oshurko

We find a family of exact solutions to the Einstein–Maxwell equations for rotating cylindrically symmetric distributions of a perfect fluid with the equation of state p=wρ (|w|<1), carrying a circular electric current in the angular direction. This current creates a magnetic field along the z axis. Some of the solutions describe geometries resembling that of Melvin’s static magnetic universe and contain a regular symmetry axis, while some others (in the case w>0) describe traversable wormhole geometries which do not contain a symmetry axis. Unlike Melvin’s solution, those with rotation and a magnetic field cannot be vacuum and require a current. The wormhole solutions admit matching with flat-space regions on both sides of the throat, thus forming a cylindrical wormhole configuration potentially visible for distant observers residing in flat or weakly curved parts of space. The thin shells, located at junctions between the inner (wormhole) and outer (flat) regions, consist of matter satisfying the Weak Energy Condition under a proper choice of the free parameters of the model, which thus forms new examples of phantom-free wormhole models in general relativity. In the limit w→1, the magnetic field tends to zero, and the wormhole model tends to the one obtained previously, where the source of gravity is stiff matter with the equation of state p=ρ.


Entropy ◽  
2020 ◽  
Vol 22 (12) ◽  
pp. 1431
Author(s):  
Gaia Pozzoli ◽  
Mattia Radice ◽  
Manuele Onofri ◽  
Roberto Artuso

We consider a continuous-time random walk which is the generalization, by means of the introduction of waiting periods on sites, of the one-dimensional non-homogeneous random walk with a position-dependent drift known in the mathematical literature as Gillis random walk. This modified stochastic process allows to significantly change local, non-local and transport properties in the presence of heavy-tailed waiting-time distributions lacking the first moment: we provide here exact results concerning hitting times, first-time events, survival probabilities, occupation times, the moments spectrum and the statistics of records. Specifically, normal diffusion gives way to subdiffusion and we are witnessing the breaking of ergodicity. Furthermore we also test our theoretical predictions with numerical simulations.


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