О контактной прочности эвольвентных зубчатых передач

Приведены результаты численного моделирования контактного взаимодействия зубьев эвольвентной прямозубой зубчатой передачи при перекосах осей зубчатых колес. Показано отсутствие дополнительного (помимо известного герцевского) влияния приведенного радиуса кривизны контактирующих поверхностей на нагрузочную способность контакта, что опровергает данные, содержащиеся в некоторых литературных источниках. Установлено, что расчет контактной прочности эвольвентных передач по стандартной методике дает заниженные показатели по напряжениям и завышенные по нагрузочной способности в сравнении с результатами, полученными на расчетной модели.The computer simulation results for contact interaction of the spur involute gearing teeth at skewness of axes of the gear wheels are present. The absence of additional influence (besides known Hertz one) of the reduced principal curvature radius for contacting surfaces on the load-carrying capacity of the contact is shown. That disproves data of some references. It is stated that a calculation of contact strength of the involute gearing, based on the standard method, leads to decreased results on stresses and to increased results on load-carrying capacity by comparing with the data obtained in the numerical model

FACTORES QUE INHIBEN EL PROCESO DE INCORPORACIÓN FISCAL DE LAS MICRO EMPRESAS AL SAT MÉXICO Y DIAN COLOMBIA

Contaduría PúblicaLa presente investigación trata sobre un análisis comparativo de los factores que inhiben en el proceso de incorporación fiscal al SAT México y DIAN Colombia de las Microempresa; en la cual se estudia el impacto histórico e importancia de estas sociedades en los respectivos países, también los trámites que debe realizar para trasladarse del sector informal al formal; cabe resaltar que cada sistema tributario es diferente; se describen las obligaciones fiscales correspondientes, beneficios, apoyos y programas gubernamentales con el fin de determinar las facilidades fiscales otorgadas por las autoridades Hacendarias de cada país para dicha incorporación. Se realizó considerando una metodología de enfoque cuantitativo y con un alcance descriptivo , como estrategia se utilizó la aplicación de un cuestionario, a través de este instrumento se pudo realizar las conclusiones, también responder a las interrogantes y problemas descritos inicialmente, los resultados de la investigación mostraron que el sistema fiscal mexicano en comparación con el colombiano, ha logrado que las microempresas se formalicen, sin importar su población total, los tramites, licencias, permisos que se deben diligenciar, y las tarifas tributarias. Los dirigentes han implementado leyes y programas que estimulan la inscripción.This research deals with a comparative analysis of the factors that inhibit the process of fiscal joining the SAT Mexico and Colombia DIAN of Microenterprise; in which the historical impact and importance of these companies in the respective countries, also procedural burdens to move from informal to formal is studied; it should be noted that each tax system is different; the corresponding tax obligations, benefits, and government support programs in order to identify the main differences between the tax facilities granted by the tax authorities of each country for such incorporation described. It was done considering a methodology of quantitative approach and with a descriptive scope, as strategy was used the application of a questionnaire, through this instrument could make the findings also answer the questions and problems initially described, the results of the investigation showed that the system Mexican tax compared to the Colombian, has made formalize microenterprises, regardless of their total population, the paperwork, licenses, permits that must be filled out, and tax rates. The leaders have implemented laws and programs that encourage enrollment

Geometry of obstructed equisingular families of projective hypersurfaces

We study geometric properties of certain obstructed equisingular families of projective hypersurfaces with emphasis on smoothness, reducibility, being reduced, and having expected dimension. In the case of minimal obstructness, we give a detailed description of such families corresponding to quasihomogeneous singularities. Next we study the behavior of these properties with respect to stable equivalence of singularities. We show that under certain conditions, stabilization of singularities ensures the existence of a reduced component of expected dimension. For minimally obstructed families the whole family becomes irreducible. As an application we show that if the equisingular family of a projective hypersurface H has a reduced component of expected dimension then the deformation of H induced by the linear system |H| is complete with respect to one-parameter deformations.Comment: 30 pages. v2: more detailed explanations. v3: minor corrections, version to appear in the Journal of Pure and Applied Algebr