Search

This paper studies the mechanical behavior of high-density polyethylene (HDPE), from which the pipes used for water transport in water supply networks are manufactured. The study was generated by the practical problem of replacing and modernizing a water network of a city with 300,000 inhabitants. Of the numerous problems that have arisen and been solved by the group of researchers, only those referring to the mechanical behavior of the materials used for pipes are presented. HDPE, which is a thermoplastic material, is suitable for manufacturing the pipes used in water supply networks, having many advantages. Data on the mechanical properties of the material of which the pipe and elbow are made is obtained experimentally. The work involved the main steps required to design a water network, but the subject is not exhausted. The stresses in the polyethylene pipe are determined in two cases: buried in the ground and supported in a concrete massif. Thus, by calculation, the advantage offered by the second solution is justified. The crack of the pipes manufactured from HDPE is studied, taking into account the classical model used in the cracking process. A simulation of pipes and elbows cracking was made. The results obtained via MEF are useful for the users of the networks.

The paper presents an automated concept of a potato sizing equipment. The technological flow is represented by dimension charts done in the software CATIA v5 r18. The classical technological flows of potato sizing are rigid systems, but modern systems are flexible and have modular construction. Modular construction has the advantage that when a component of the equipment breaks out, it can be moved away and thus not affecting the entire equipment. The role of automation is illustrated by the designing of an original potato sizing machine, based on the real geometrical quotation.

The first part of the paper presents the equivalent dynamical model of the forklift system in the most difficult work situations: descending on a slope braking of the vehicle in translational motion and acceleration of the fork while lifting the load. Based on the dynamical model are elaborated the mathematical models describing the dynamical behavior of the forklift truck during moving or working. These models deliver the criteria for the overturning stability. The last section of the paper presents a measurement installation developed for experimental research on the dynamics of the fork lift truck.

In this issue are included scientific articles which debate problems from social science fields: Romanian confessional education, National Socialis, austerity, human security, religion and reconstruction, democratization, extraction algorithms, preventic mechanical damage, Romanian criminal Law, Satirical Spirrit, Romanian language and Creativity through education. Authors talk about subjects as Paradigms in the Romanian Communism, food, global security, postcommunism and public policies.Research and Science Today Journal is a publication founded in 2011 and it is dedicated to the students of all levels (license, master and doctoral) of faculties in the country and abroad. We want to offer the participants the opportunity to present their scientific works in the following areas: Social Sciences, Economic Sciences, Legal Sciences, Humanities, Education Sciences, Engineering, Medicine and Sport.This journal provides students the opportunity to create and/or to improve their abilities to write scientific papers. So each appearance (two appearances per year at which we can add supplements) contains a number of papers written by students, masters and doctoral from the faculties from the country or/and abroad. The journal promotes original studies contributing to the progress of knowledge and it is motivated by the need to address issues of theory and practice in the areas mentioned above.The Journal is a training means of the factors involved in the conceptualization, development, implementation and evaluation, aiming the formation of creative personalities who could be able to adapt through the changing conditions of life.Journal wants to be a forum for debates disciplinaries and interdisciplinaries theoretical topics, to become a research support, to leverage this work at regional, national and international levels. We believe that this gathering will enjoy the support from both parts of the researchers and of the practitioners, and will provide appropriate training sources held professional through the current problems.