The 16th issue of RECENT journal was edited and multiplied with support of:
Some Optimizer Observations about Hydraulic Shock in Pressure Pipes
» Abstract. The authors approach the problem of strain increasing in pressure pipes material in the case of hydraulic shock appearance. Starting from relative known formulas for straight, positive, maxim hydraulic shock, the authors have obtained new, original, dimensional and dimensionless relations and indicators, including all the constructive factors for exploitation and for influence, which makes evident all technical solutions that can be adopted, simple or complex (for more simultaneous factors), for strain reduction or diminution and for distortions and damages avoidance. The paper has one concrete numerical application.
» Keywords: pressure pipe, hydraulic shock
ON THE CIRCUMFERENTIAL STRESSES IN CURVED BEAMS UNDERGOING COMBINED LOADING
» Abstract. The multi-criterion design problem of a pair of involutes spur gears is formulated and solved as a general nonlinear optimization problem. Its distinguished feature is the use of life balance criteria of gear teeth (bending fatigue and contact fatigue) by varying of the strength of their materials. The proposed approach has two stages: at the first stage, the parametric space is preliminary determined by the use of quasi-Monte Carlo method and a feasible set of possible solutions is pointed out. At the second stage, contracted subsets of Pareto optimal points are selected in order to make a final compromised decision. The proposed approach is illustrated by a numerical example.
» Keywords: circumferential stress, curved beam, finite element method
DYNAMIC MODELING OF A 2-CARDAN TRANSMISSION IN A MODULAR VARIANT. PART I. MODELLING OF THE REPRESENTATIVE MODULES
» Abstract. In this paper there are synthetically presented the structural typical modules of a 2-Cardan transmission and there are established the generalized analytical models of the forces from these modules. By means of these modules, the dynamic computational modeling of these transmissions can be generalized and become more simple and unitary.
» Keywords: structural module, 2-Cardan transmission, analytical generalized model
FEEDBACK LINEARIZATION IN ROBOTS' TECHNIQUE
» Abstract. Feedback linearization is a nonlinear system design strategy, which use the design methods specific to linear systems. This method offers excellent results if the dynamic robot model is known with sufficient precision. The approach presented in this work analyzes the feedback linearization for robots technique, for both, joint space and Cartesian space to more general model. The notion of feedback linearization of nonlinear systems is a relatively recent idea in control theory, whose practical realization has been made possible by the rapid development of microprocessor technology. The basic idea of feedback linearization control is to transform a given nonlinear system into a linear system by use of a nonlinear coordinate transformation and nonlinear feedback.
» Keywords: robots, dynamics, feedback linearization
ENVIRONMENT INVESTMENT. CONCEPT AND CONTENT
» Abstract. The article presents the researches results situated around the investment concept. The analysis of basic theoretical elements that constitute the substance of this concept has permitted some conclusions regarding to the investment having as the result the environment protection at the enterprise level.
» Keywords: investment, environment, efficiency, content, duration, risk
STUDY ON CONVECTIVE HEAT TRANSFER TROUGH FINNED TUBES
» Abstract. Because fins can significantly enhance convective heat transfer they have enormous technological importance. In this paper some heat transfer processes in steady state conditions, between a finned tube and an external gas, are carried out with aid of ANSYS professional package (thermal module), a state of art finite element software. The parameters systematically varied were the diameter and thickness of the fins and the paper presents the results concerning the influences of these parameters on thermal process. The main quantities of the heat transfer (temperature, heat flux) are calculated in this configuration, and the main conclusions are supported by the analysis of the thermal distributions along fins.
» Keywords: convection, CFD analysis, temperatures in nodes, heat flux
WAFERBOARD AND ITS ADHESIVE CONSUMPTION
» Abstract. The work-paper presents some aspects of specifically consumption for adhesive from industry of chipboard. It is analyzed the using of adhesive percentage and the consequence of this use in waferboard technology. It is proposed the use of specifically consumption of adhesive expressed in g/m2, as good modality for eliminate the negative effects of the first indicator in technology of waferboard.
» Keywords: specifically consumption of adhesive, adhesive percentage, waferboard
RESEARCHES ON THE SPINNING OF HOLLOW PARTS
» Abstract. The paper presents some researches about the manufacturing of sheet metal hollow parts by spinning, when using a special spinning head. The head is mounted on a common lathe and is provided with four special rollers. The paper presents the geometrical parameters of the rollers and some results on the spinning coefficient. The manufacturing system is provided with a dynamometer for measuring the working force. The method can be used instead of a regular one, with rigid punch and die, having the advantage of a cheaper tool and of a lower working force, due to changing the gliding friction with a rolling one. The quality of the parts is very good, because of the special shape of the rollers, that of a double truncated cone.
» Keywords: sheet metal, spinning, lathe, parameters, roller
ASPECTS REGARDING THE IMPLEMENTATION OF WASTE PRODUCTS MANAGEMENT IN ROMANIA
» Abstract. European legislation promotes a frame for waste management and includes a preferential hierarchy for these management options. The strategies regarding the waste management should focus as well on reducing the quantity of produced waste, as well as on the possible risks. Where producing waste is inevitable, recycling should be an important concern. The usage of waste as an energy source is preferable to its storage (depositing should be used just as an ultimate solution).
» Keywords: waste, management, recycling
DIMENSIONING PARTICULARITIES OF HYDRAULIC PRESS CYLINDER IN THE FREQUENCY AND STROKE IMPOSED CONDITIONS
» Abstract. In this paper are presented solutions of dimensioning the diameter of a piston and of a rod of the linear hydraulic motor for two schemes of supplying and recommendations of approaching the stages of designing are made.
» Keywords: linear hydraulic motor, hydraulic press, dimensioning
ASPECTS REGARDING CLEAN TECHNOLOGIES AND THEIR CRITICAL HIT OVER THE INDUSTRIAL ENVIRONMENTAL PROTECTION
» Abstract. The paper presents industrial environment protection knowledge defined as "Clean technology", the most important aspects of this concept as the application of this knowledge.
» Keywords: clean technology, sustainable development, environmental protection
PROGRAMMED GENERATOR FOR TEST TELEVISION SIGNALS
» Abstract. This
paper presents the construction and principles of a programmed generator
of standard TV signals. The generator is used for controlling the
function of TV receivers and circuits of the communication TV channel.
The suggested-programmed generator is a complex machine, which can
generate video and radio frequency signals specific to the TV radio
communication system. The varieties of test TV signals, which can be
generated, are obtained with a programmed micro controller. The programs
are conceived and changed by the users with the personal computer’s
» Keywords: TV generator, TV programmed generator, TV generator with micro controller, measurements in television
NEW CONCEPT FOR THE S.D.-0195 SANDBLASTER
» Abstract. This paper presents the stages and the results of a design study on S.D.0195 dental sandblaster, the goal being to review the design by its ergonomic and aesthetic characteristics. The study was based on functional, comparative, ergonomically and multi-criteria analyses.
» Keywords: design, ergonomic, concept, sandblaster
CONSIDERATIONS REGARDING THE FUNCTIONING OF AN A.C.O. SYSTEM FOR GRINDING MACHINE TOOLS
» Abstract. One way of improving the operating performance of the grinding machine tools is the adaptive control through an A.C.O system. The present work analyses the opportunity of adopting just such a system for the grinding of external cylindrical surfaces with traverse feed. Because of the complexity implied by the optimization process, this study is done by simulation, based on an original logical scheme, using the electronic computer.
» Keywords: machine tools, grinding, adaptive control
COMPARATIVE EXPERIMENTAL STUDY OF PHYSICAL-MECHANICAL PROPERTIES OF THIN PLYWOOD MADE IN WOOD OF DIFFERENT INDIGENOUS SPECIES
» Abstract. The paper intends to comparatively analyze the main physical-mechanical properties of plywood with thicknesses between 1.0 and 6.0 mm: volumic mass, thickness, tensile strength parallel and perpendicular to the fiber, coefficient of elasticity to static and dynamic bending. The research results were obtained in testing made on different indigenous species plywood that is beech, birch and alder, under industrial and laboratory conditions, in small size series.
» Keywords: plywood, static coefficient of elasticity, dynamic coefficient of elasticity, tensile strength
ROBOTIZED WELDING OF STEERING WHEEL
» Abstract. This paper presents robotized welding of a steering wheel application. There are presented, steering wheel components which must be welded in robotized technology. To do this application it has been conceived three flexible cell’s types served by a CLOOS robot type. To achieve wheel’s welding, it was necessary griping and fixing devices on a manipulator. Welding technology and robot’s program are contributions to accomplish wheel’s building in robotized technology.
» Keywords: robotized, welding, flexible cell
PARTICIPATIVE MANAGEMENT: A CHALLENGE FOR MODERN ORGANIZATIONS' ADMINISTRATION
» Abstract. The technical, economic and social evolution causes some of the accepted and implemented principles of managers to show their limits. Customer orientations, rapid and efficient response to all their requests, are becoming the principals for any successful business and successful public or private service. Classical management, which is applied nowadays in our country in most economic and social areas, is no longer fit for the present. It’s time for an evolution towards the participative management, as we will try to demonstrate in the following sections.
» Keywords: Taylor / traditional organizations, "reactive" organization, participative management