Thne 17th issue of RECENT journal was edited and multiplied with support of:
Emil ASSENOV, Lachezar NENKOV LAZOV
STUDY THE RELATIONSHIP BETWEEN TECHNOLOGICAL PARAMETERS AND GRANULARITY ON IMPACT CRUSHERS
» Abstract. This study describes the results of research of granularity of three kinds of materials (quartzite, syenite and limestone). The studies have been made on laboratory impact crusher in "Material Handling" department at TU - Sofia. Regression equations about granularity are obtained. Regression equations about influence of peripheral velocity of hammers and number of hammers on granularity are also obtained. The results are bases for the design of impact crushers.
» Keywords: granularity, impact crusher, yielding materials, experimental research
Jörg M. ELSENBACH, David L. RAINEY
CORPORATE SOCIAL RESPONSIBILITY IN THE CONTEXT OF SUSTAINABLE BUSINESS DEVELOPMENT
» Abstract. The article discusses how Sustainable Business Development (SBD) provides a strategic framework for leading change in sophisticated business settings. SBD involves leading and managing change and integrating the full spectrum of the business reality into a corporation's strategic decision-making framework. It includes the strategic direction of the corporation, its strategic management systems and the strategic leadership of the organization. It also includes all of the supply networks that support the organization and all of the customers and stakeholders. This holistic view transforms last century’s ‘supply and demand’ management thinking into a more sophisticated strategic framework that is based on strategic leadership, business innovation, value creation, social responsibility, sustainable development, inclusiveness, and many other related factors. The strategic focus shifts from short-term financial rewards to a more balanced perspective that also includes long-term business strategies, innovation management, and business integration. It allows executives and senior management to create solutions that are based on the whole of the extended enterprise and not just on producers and customers.
» Keywords: Strategic Management, Enterprise Management, Sustainable Business Development, Corporate Social Responsibility, Leadership, Organization Theory, Change Management
THE ROD-PISTON ASSEMBLY AND RELATIONS IN PROE 2001
» Abstract. The paper presents the restraints used in ProE 2001, and the parameters and relations that can be established between these. The paper further includes a personal application developed to reduce the designing time of hydraulic cylinders.
» Keywords: constraints, relations, ProE 2001
FAILURES OF PLASTIC WELDED JOINTS
» Abstract. Today, welding plastic materials is a common, relatively easy, procedure. Welding, means melting the seam between the welded parts and keeping them properly fixed in place until complete solidification occurs. This phenomena induce various mechanical-physical proprieties alterations in the joining area, witch if aren’t in an optimal values range they can be called failures. These potential failures are not obvious at first sight and a closer look is needed. When it is known what kind of failures can occur, we will have a better understanding of plastic welding and what constitutes a good or a bad plastic joint.
» Keywords: plastic, thermoplastic, failures, control, welding
Aurel FRATU, Mariana FRATU
REPETITIVE MOTION CONTROL IN ROBOTS MANIPULATORS’ TECHNIQUE
» Abstract. This paper is devoted to the repetitive motion control of robots manipulators. In this approach, we will analyze the important properties of repetitive motion: trajectory is periodical or is reinitialized at the beginning of each cycle. One of the central problems in the motion control of the robot arm is the specification of dynamically feasible trajectories for motion planning. We will attack the problem of commands needed for the robot control in case of pure movement along the desired path, that is definite in passing points of feasible trajectories.
» Keywords: repetitive motion, periodical trajectory, motion control
OXYGEN SENSOR FOR BIOTECHNOLOGICAL MEASUREMENTS
» Abstract. A construction of classical oxygen sensor is proposed with elements that ensure it usage for biotechnological purposes. Designed and manufactured amperometric sensor is destined to work with enzyme membranes. For that a special cap is designed by means of membranes one or more can be health. That cap ensures better contact with the measured substrate and better fixture. The other advantage is that membranes can be prepared previously and independently with exact defined size and distribution of enzyme. The work of operator is made easier significantly.
» Keywords: oxygen sensor, membranes, construction, elements
THE CURVE CUTTING WITH BLADE BAND
» Abstract. The paper presents a synthesis of the problems which appear when wood is processed curvedly with blade band, especially when it is used technological devices for curve cutting. It is also analyzed the dependence relationship between dimensional features of blade band and the ray of cutting for wooden semi-product or materials.
» Keywords: wood, cutting with blade band, device for curve cutting
KNOWLEDGE MANAGEMENT IN HIGHER EDUCATIONS
» Abstract. Because of increased competition and of new exigencies concerning higher education, the higher education institutions borrows, like other public organizations, characteristics specific to the economic organizations behaviour, for which using knowledge management have become a desideratum and a necessity, in this context, the paper aiming to present a description of the main elements composing a knowledge management system specific to higher education institutions and its relations to quality management.
» Keywords: knowledge management, quality management, knowledge management system
Elena MACHEDON-PISU, Teodor MACHEDON-PISU
RESEARCH OF FRICTION WELDING USING INSERT METAL
» Abstract. Friction welding has been applied in many fields as a means for joining similar or dissimilar materials. In this article, we propose a friction welding technique using an insert metal to produce satisfactory joints of dissimilar metals exhibiting poor weldability.
» Keywords: friction welding, dissimilar metals, insert metal
Mihai MAŞNIŢĂ, Ioan CIOBANU, Vlad MONESCU
COMPUTER PROGRAM TO SIMULATE THE MACRO-SOLIDIFICATION OF CASTINGS USING MATLAB SOFTWARE
» Abstract. In this paper we present the results obtained regarding macro-solidification simulation of castings with an own computer program based on MATLAB software. There are presented the researches made by us, with a view to verify the program performance and the exploitation possibilities of the results obtained by graphical representation and data interpretation.
» Keywords: solidification, modeling, simulation, casting
Ioan MATLAC, Lucian IULIAN, Gheorghe PANĂ
MODELING OF BUCK CONVERTER WITH RC LOAD
» Abstract. Electrical converters can solve, using periodical switching, the power control from sources to loads. The power transferred from D.C. source to the load through buck converter and the dependence between transferred power, duty factor and the switching frequency are presented. In this paper the equivalent circuit of buck converter, supplied from D.C. source, with RC load is presented and are deduced their equations and so modeling it in permanent regime.
» Keywords: buck converter, duty factor, RC load
Sorin Ioan MUNTEANU, Ioan CIOBANU, Aurel CRIŞAN
RESEARCHES ABOUT SOLIDIFICATION DIRECTING FOR CASTINGS OF SMALL DIMENSIONS WHEEL TYPE
» Abstract. In the paper there are presented the results of a research regarding the real solidification modules method application in the view of solidification analysis of wheel type castings with small dimensions. There are presented the possibilities to direct the solidification by using coolers and feeder heads. It is highlighted that in the case when the hub has a thickness higher or comparable with the inner core radius, the classic direct feeders do not assure a sufficient directing of the solidification. To surely eliminate the shrinkage from the hub in that cases it is advised to use heat insulated feeders or exothermal feeders.
» Keywords: casting, directional solidification, solidification module
Irena NIKOLOVA, Milka VICHEVA
SAFETY ASSURANCE OF PRODUCTS IN THE EUROPEAN SINGLE MARKET
» Abstract. The free movement of products - goods and services is a necessary condition for correct functioning of the European single market. To ensure identical conditions for access of products to the markets in all member states in European Union and to guarantee their safety, a regulation of technical requirements to specific kind of goods or large groups of goods is needed. That regulation is implemented by European technical legislation (ETL). This paper considers the character of the ETL, its trends, kinds of norms and approaches for its realization. Special features of new approach and its basic principles are analyzed. Characteristics and conditions for application the horizontal directives like the directive for common safety of products and the directive for responsibility about the product are shown. On the basis of analysis made, the trends for guarantee the safety of manufactured technical products by means of incorporation the technical specifications from harmonized standards into the design methods are outlined. That will accelerate the process of design and manufacture and will guarantee consumers’ protection from dangerous for their health products.
» Keywords: European technical legislation, safety of products, new approach, harmonized standards
Radu SĂULESCU, Dorin DIACONESCU, Alina BORCA
DYNAMIC MODELING OF A 2-CARDAN TRANSMISSION IN A MODULAR VARIANT. PART II: THE DYNAMIC ANALYSIS OF A TRANSMISSION
» Abstract. In this paper it is proposed a general algorithm for the computational dynamic modeling of the Cardan transmissions. This algorithm relies on the assemblage of the analytical models of modular type, established previously and is exemplified on a representative 2-Cardan transmission.
» Keywords: general algorithm, computational dynamic modeling