Vibroactive Pad Improvement Using Stack Type Piezoactuator

Previously created vibroactive pad encounters with a problem, i.e. vibrations are not fully descended, since amplitudes of vibroactive pad are lower. In microstructure replication process it causes insufficient flow of fluid, since it is directly dependent on the amplitude of excitation. As a solution for this problem stack type piezoactuator together with vibroactive pad of new construction are proposed. It is known, that stack type piezoactuators are able to reach higher amplitudes, than single piezoceramics can do, thus it is considered as a solution, in order to overcome previously mentioned problem. In this paper new construction of vibroactive pad is presented and numerically analyzed using Comsol Multiphysics 3.5a. software in order to determine its natural frequencies

Numerical investigation of dynamical properties of vibroactive pad during hot imprint process

The operating frequencies of the vibroactive pad used in order to improve the quality of replicas of complex microstructures during the mechanical hot imprint process, are numerically analyzed in this paper. It is known that piezoceramics (and in the same time all construction) change its dynamical properties under the action of mechanical load. It is necessary to investigate dynamical properties of vibroactive pad, in order to improve the quality of replicas when planning more detailed research and development in this field in the future. Experimentally there is no possibility to determine the frequency for the construction to be excited, in order to reach modes of forms, thus modeling of the process was performed. The created mathematical model of vibroactive pad was implemented by FEM using COMSOL Multiphysics software. The vibroactive pad’s numerical analysis was performed with and without the action of mechanical load, as well experimental verification of model was performed (for the validation of the model without load with experimental data)

Numerical Investigation of Dynamical Properties of Vibroactive Pad

The operating frequencies of the vibroactive pad used in order to improve the quality of replicas of complex microstructures during the mechanical hot imprint process, are numerically analyzed in this paper. It is known that piezoceramics changes its dynamical properties under the action of mechanical load. It is necessary to investigate dynamical properties of vibroactive pad, in order to improve the quality of replicas when planning more detailed research and development in this field in the future. Experimentally there is no possibility to determine the natural frequency for the construction to be excited, in order to reach the same modes of forms, thus modeling of the process was performed. The created mathematical model of vibroactive pad was implemented by FEM using COMSOL Multiphysics software

Development of intermodal transport in new European Union states

The article presents the main outcomes of the NAS-ITIP project (FRAMEWORK'5) on the situation of intermodal transport in new European Union states. The main measures for the development of intermodal transport in these countries are highlighted: modernisation and development of intermodal infrastructure; innovative technologies; establishment of modern logistics centres. Recommendations to EC and national governmental institutions for the development of intermodality are proposed

Lithuanian higher education: between path dependence and change

Over the past century, Lithuanian higher education has experienced a steady horizontal differentiation. It started with a moderate differentiation in the Soviet times and intensified after 1990 when two regional universities and new specialized universities were created, many universities opened new programmes, and Vytautas Magnus University was re-established. Horizontal differentiation was especially fostered by the Law on Higher Education and Science in 2000, as it created a binary higher education system and allowed the establishment of private universities and institutions of a non-university type. This development opened the door to a number of small private and public colleges which strongly focused on management, business and law - the subjects which were in high demand at that time. These subjects were also taught at different universities, with new management and social sciences programmes being introduced at all universities, even though they could be, for instance, specialized in sports or agriculture. This blossoming of programmes and rapid system expansion catered for the ever increasing number of students, when up to 70% of high school graduate cohorts were going to obtain higher education. Issues of quality as well as funding through tuition fees were often the topic of policy debates. The state used quality assurance instruments of programme accreditation as well as institutional evaluations to "tame" the expansion of programmes and to ensure minimum quality. As the demographic reality started to change and student numbers started to drop (with the prognosis of 40% drop until 2020) the vertical differentiation started to increase even further. Some institutions in Lithuania have changed their names quite a few times, sometimes to ensure that the same rector will be in office for a longer period of time than usual (e.g. Lithuanian University of Educational Sciences, Mykolas Romeris University). At the same time, renaming institutions has served the symbolic purpose of "relabelling" into a new profile, which may reflect institutions’ intentions to "abandon" earlier legacies and specializations (in the case of Mykolas Romeris - former police school, and then law and social sciences orientation) and to signal that the profile of the institution has become broader. The Lithuanian higher education system was vertically differentiated from the outset - with one main classical comprehensive university catering for the needs of the nation. This trend has been maintained after 1990. However, the stratification of the institutions has increased due to the creation of the binary system, as well as the appearance of private higher education institutions. The prestige of public traditional universities and technological universities has remained the same, with Vilnius University still being the top university in terms of research output and student numbers. The specialized public institutions are stratified into two main categories. The well-established and prestigious specialized Arts and Music Academies and the Lithuanian University of Health Sciences recruit students on a national basis and have good reputation both nationally and internationally. At the same time, regional universities as well as some private higher education institutions and public colleges serve regional needs. They enjoy moderate prestige and have certain research strengths, but their main focus is on teaching and contribution to regional economy and knowledge transfer. Recent national rankings, a variety of international rankings of study programmes and the attempt of the Ministry of Education and Science to evaluate research quality at Lithuanian universities in 2014-2015 show that the government is keen to identify "winners and losers" in the system. Further, the Centre for Quality Assessment in Higher Education with its programme and institutional accreditations has indirectly sustained the system’s vertical differentiation. However, it is not that easy to establish a thoroughly stratified system in Lithuania as there are many lobby forces and a strong tradition of higher education funding on historical basis, which is not easy to uproot. The main developments towards performance-based funding and especially the availability of science funding via Lithuanian Research Council for basic research using EU Structural Funds seem to be one of the main instruments to boost the prestige of researchers and research groups from Lithuanian universities. Teaching and research at universities have been "reconnected" in stronger ways due to external research funding. In this respect, the role of the Lithuanian Research Council as well as EU funding in the stratification of the system should not be neglected. [...