Ising Universality in Three Dimensions: A Monte Carlo Study

We investigate three Ising models on the simple cubic lattice by means of Monte Carlo methods and finite-size scaling. These models are the spin-1/2 Ising model with nearest-neighbor interactions, a spin-1/2 model with nearest-neighbor and third-neighbor interactions, and a spin-1 model with nearest-neighbor interactions. The results are in accurate agreement with the hypothesis of universality. Analysis of the finite-size scaling behavior reveals corrections beyond those caused by the leading irrelevant scaling field. We find that the correction-to-scaling amplitudes are strongly dependent on the introduction of further-neighbor interactions or a third spin state. In a spin-1 Ising model, these corrections appear to be very small. This is very helpful for the determination of the universal constants of the Ising model. The renormalization exponents of the Ising model are determined as y_t = 1.587 (2), y_h = 2.4815 (15) and y_i = -0.82 (6). The universal ratio Q = ^2/ is equal to 0.6233 (4) for periodic systems with cubic symmetry. The critical point of the nearest-neighbor spin-1/2 model is K_c=0.2216546 (10).Comment: 25 pages, uuencoded compressed PostScript file (to appear in Journal of Physics A

Organic chemistry. History and mutual relations of universities of Russia

© 2017, Pleiades Publishing, Ltd. The review describes the history of development of organic chemistry in higher schools of Russia over a period of 170 years, since the emergence of organic chemistry in our country till now

The impact of marketing resources for initiation of children and the safety of troops in the paid sections Taekwondo

The article deals with the problem oforganizing and marketing features of the paid sports and sports services that provide educational complex. Presents the results of experimental work, a comparison of indicators of influence of advertising, PR in the process of initiation and security forces in the experimental group and control toll free group, the results of the survey conducted to identify the motives, to give children the previous 7-8 years, in the section on taekwondo and possible reasons for the refusal to deal with children in pai

CONTACT PROBLEM FOR A TWO-LAYERED CYLINDER

Introduction.  The investigation of the contact problems  for cylindrical bodies is urgent due to the engineering contact strength analysis on shafts, cores and pipe-lines. In the present paper, a new contact problem of elastostatics on the interaction between a rigid band and an infinite two-layered cylinder, which consists of an internal continuous cylinder and an outer hollow one, with a frictionless contact between the cylinders, is studied. The outer cylindrical band of finite length is press fitted. By using a Fourier integral transformation, the problem is reduced to an integral equation with respect to the unknown contact pressure.Materials and Methods. Different combinations of linearly elastic materials of the composite cylinder are considered. Asymptotics of the symbol function of the integral equation kernel at zero and infinity is analyzed. This plays an important role for the application of the analytical solution methods. A key dimensionless geometric parameter is introduced, and a singular asymptotic technique is employed to solve the integral equation.Research Results. On the basis of the symbol function properties, a special easily factorable approximation being applicable in a wide variation range of the problem parameters is suggested. The Monte-Carlo method is used to determine the approximation parameters. The asymptotic formulas are derived both for the contact pressure, and for its integral characteristic. Calculations are made for different materials and for various relative thickness of the cylindrical layer  including thin-walled layers.Discussion and Conclusions. The asymptotic solutions are effective  for  relatively  wide  bands  when  the  contact  zone length is bigger than the diameter of the composite cylinder. It is significant that the method is applicable also for those cases when  the  outer  cylindrical  layer  is  treated  as  a  cylindrical shell. The asymptotic solutions can be recommended to engineers for the contact strength analysis of the elastic barrels with a flexible coating of another material

Informe técnico final del proyecto “Manejo de desastres ante eventos meteorológicos extremos (sequías, heladas y lluvias intensas) como medida de adaptación ante el cambio climático en el valle del Mantaro - MAREMEX”

Resumen en inglés incluidoEl proyecto “Manejo de desastres ante eventos meteorológicos extremos (sequías, heladas y lluvias intensas) como medida de adaptación ante el cambio climático en el valle del Mantaro” - también conocido como MAREMEX-Mantaro -, se inició en febrero del año 2009, y con una duración de 36 meses tuvo por objetivo principal el de fortalecer la capacidad en el manejo del riesgo ante eventos meteorológicos extremos por parte tanto de la población como de las instituciones que tienen el manejo de los recursos naturales a su cargo, a fin de disminuir la vulnerabilidad de la población urbana y rural en el valle del Mantaro. El desarrollo del proyecto consideró la alta vulnerabilidad del valle del río Mantaro, - localizado en los Andes Centrales Peruanos -, a eventos meteorológicos extremos relacionados con la variabilidad climática, así como los estimados de que dicha vulnerabilidad se incrementaría en los siguientes años debido al cambio climático (IGP, 2005). Debido a la amplitud de la zona de estudio se priorizaron 3 subcuencas de estudio (Shullcas, Cunas y Achamayo), las que se escogieron tomando en cuenta varios factores: representatividad de ecosistemas, vulnerabilidad a la ocurrencia de los eventos meteorológicos identificados, accesibilidad, existencia de zonas urbanas de importancia, interés e intención de participar, etc. Entre los objetivos específicos se buscó fortalecer y profundizar los estudios sobre causas, ocurrencia e impactos de heladas, sequías y fenómenos de lluvias intensas en la región; identificar los actores claves involucrados y evaluar las actuales capacidades de los pobladores del valle del Mantaro en el manejo del riesgo de desastres ante la ocurrencia de eventos meteorológicos extremos; elaborar un plan integrado de manejo de riesgo y estrategias de adaptación frente a heladas, sequías y lluvias intensas en el valle del Mantaro (con la participación de autoridades locales, gobiernos regionales, comunidades, ONG y otros actores relevantes); y promover el fortalecimiento institucional y difusión de los resultados del proyecto a la población, instituciones y medios científicos, a través de la creación o fortalecimiento de capacidades de investigación de entidades e investigadores locales en temas de adaptación al cambio climático..

Organic chemistry. History and mutual relations of universities of Russia

© 2017, Pleiades Publishing, Ltd. The review describes the history of development of organic chemistry in higher schools of Russia over a period of 170 years, since the emergence of organic chemistry in our country till now