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SERIA D
Inginerie Mecanică
Excelență în Cercetare
Din 1929
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APPLYING LEM TO DÃFFING’S OSCILLATOR
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Petre P. TEODORESCU, Ileana TOMA
The linear equivalence method (LEM) was previously introduced by Toma to for getting and studying - both numerically and qualitatively - the solutions of nonlinear dynamical systems. LEM is applied here to Düffing equation. The normal LEM representations emphasize the dependence on parameters...
CONSIDERATIONS UPON THE SYMMETRICAL HORIZONTAL FLIGHT OF A FLAPPING WING MICRO AIR VEHICLE
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Andrei CRAIFALEANU, Valentin BUTOESCU, Cristian DRAGOMIRESCU, ªtefan NEBANCEA
The instantaneous values and the time-averaged values, respectively, are determined for the lift force and thrust generated during symmetrical horizontal flight of a flapping-wing micro air vehicle (FWMAV). The study methods are applied on a simplified but general model, which can be used,...
EXPERIMENTAL RESEARCHES ON CORRELATION SOURCE-NOISE LEVEL GENERATED AT VENTILATING AND AIR CONDITIONING INSTALLATIONS
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George Cãtãlin ION, Elena Elvira ION
For reducing noise levels at ventilating and air conditioning installations, an exact understanding of causes and their occurence are of primary interest. Then, one tries to find new and viable solutions for the proposed goal. Experimental researches performed on an installation with different...
REDUCTION OF THE ELEMENTARY BODIES TO SYSTEMS OF MATERIAL POINTS WITH THE SAME INERTIA PROPERTIES
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Nicolaie ORASANU
In this paper the author proposes some mathematical models of reduction of the elementary bodies to systems of material points with the same inertia properties, which means: the same centre of mass and the same tensor of inertia. Starting from these models, each body can be reduced to a system...
PURE SHEARING TESTS OF A PRANDTL-TYPE MATERIAL
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Costicã ATANASIU, ªtefan Dan PASTRAMÃ, Florin BACIU, Daniel VLÃSCEANU
Chromoplastic materials can be included in the category of materials that have a Prandtl-type characteristic curve. Such materials were obtained in Romania, at the Chemical Research Institute Bucharest and they are compounded polymers that have a linear-perfect plastic behavior in traction. The...
ASSISTED RESEARCH OF THE FOURIER SPECTRUM OF THE ROBOTS WITH MAGNETORHEOLOGICAL DAMPER
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ªerban OLARU, Aurel OPREAN, Adrian OLARU
The paper presents one new method of the assisted determination of the transfer function of the vibrations, global dynamic compliance and of the transmissibility of one didactical robot with magnetorheological damper. By using the comparative method and the proper virtual Fourier analyzer, we...
RESEARCH ON ENVIRONMENTAL POLLUTION WHEN USING SHIELDED METAL ARC WELDING (SMAW)
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Gheorghe AMZA, Corneliu RONTESCU, Dumitru - Titi CICIC, Zoia APOSTOLESCU, Dan PICÃ
This paper presents the types of noxious substances and the quantities determined following the experiments using shielded metal arc welding (SMAW).\r\nIt also presents the influence of the main parameters of the welding procedure on the pollution coefficient.
SURFACE ROUGHNESS AT MILLING ZINC ALLOYS
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Ioan CÃLINESCU, Sorin Mihai CROITORU, Constantin MINCIU
The paper presents experimental research and results in case of determining surface roughness when milling workpieces made of zinc alloys. Even if zinc alloys are used in many cases for mass production and large series of products, until present these materials are not known from the cutting...
RESEARCHES ABOUT THE TEMPERATURE OF THE CUTTING EDGE IN TURNING OF UNALLOYED STEEL
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Gheorghe CEAU, Victor POPOVICI, Sorin CROITORU
This paper is the result of the authors’ investigations on the temperature at the edge of the tool, during turning of unalloyed steel, depending on the parameters of the cutting process with conventional values. For the determination of the temperature values of the cutting edge an...
TRANSIENT FLOWS WITH INERTIAL EFFECTS IN WATER SUPPLY SYSTEM OF THE HYDROPOWER PLANTS
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Angela NEAGOE, Radu POPA
The algebraic waterhammer method has been adapted to transient flow analysis along the whole hydraulic route between reservoir and plant’s turbines. The model allows to include the inertial and friction effects of water column into the surge – tank and secondary intake shaft, and the...
µPIV MEASUREMENT AND NUMERICAL COMPUTATION OF THE VELOCITY PROFILES IN MICROCHANNELS
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Cãtalin Mihai BÃLAN, Corneliu BÃLAN
The present paper is dedicated to the experimental investigations and numerical simulations of the velocity distributions in micro-channels geometry, for pure viscous Newtonian fluids and complex fluids characterized by the shear thinning behavior. The steady flow kinematics in...
PUMPING STATIONS SCHEDULING FOR A WATER SUPPLY SYSTEM WITH MULTIPLE TANKS
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Sanda-Carmen GEORGESCU, Radu POPA, Andrei-Mugur GEORGESCU
Let\\\\\\\'s consider a looped water supply network with variable demand, which includes two pumping stations (each with 3 pumps working in parallel at constant speed), a suction reservoir with constant level and two tanks with variable water level. Using the Honey Bees Mating Optimization...
OXYGEN CONCENTRATION PROFILES IN COMBINED FINE AND MEDIUM BUBBLES AERATION SYSTEM
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Aurelia CÃLIN, Diana ROBESCU, Dan ROBESCU
The biphasic gas-liquid systems are widely used in wastewater treatment and purification techniques where raised oxygen concentrations into the aqueous environment are required. This paper proposes a model for oxygen transfer from air into water in the biphasic environment liquid-air bubbles...
INFLUENCE OF HYDRODYNAMIC ACTIVATION ON A POLYMERIZATION REACTION IN A TAYLOR-COUETTE REACTOR
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Roland KÃDÃR, Zhen LIU, Matthias KIND, Corneliu BÃLAN
The present work is concerned with experimental investigations on a polymerization reaction in a Taylor-Couette reactor (TCR). The overall aim of the project is to investigate the relationship between mixing and a chemical reaction in TCR. In this work premixed monomer-solvent solutions are...
COMPARISON BETWEEN NUMERICAL SIMULATION AND MEASUREMENTS OF THE POLLUTANT DISPERSION IN A RIVER. CASE STUDY
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Virgil PETRESCU, Oreste SUMBASACU
Romania, as European Union member country, has undertaken that by 2015 to improve the surface water quality to „good ecological status”. The most at risk of failing to meet quality standards are the rivers in which wastewater (partially treated or untreated) are discharged. In the...
ECOLOGICAL MODEL (N-P) FOR SHALLOW LAKES. STUDY CASE: STIUCII LAKE
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Gabriela Elena DUMITRAN, Liana Ioana VUÃA
Global existence of a large percentage of lakes with eutrophication problems, demands a predictive tool for the quality of these ecosystems. This paper proposes an ecological model (nutrient-phytoplankton) that describes the biochemical behavior of a small natural lake eutrophic. The 1D model...
RHEOLOGICAL CARACTERISATION OF VISCOUS FLUIDS IN OSCILLATORY SQUEEZING FLOWS
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Daniela COBLAS, Diana BROBOANA, Corneliu BALAN
The study is dedicated to the investigations of a pure viscous fluid in oscillatory squeezing flow between two parallel discs. The experiments are performed using the Micro Fourier Rheometer prototype MFR 2100 and the numerical simulations of the flow are obtained with the deformation mesh...
ON THE ACCURACY OF NUMERICAL PREDICTION IN TRANSONIC-SUPERSONIC FLOW ARROUND MISSILES
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Cristina MIHAILESCU, Teodor Viorel CHELARU, Sterian DANAILA, Corneliu BERBENTE, Costicã SAVA
The aim of the paper is to validate a numerical model using a comparison with available experimental data for a slender body configuration with canard fins. Four basic configurations are considered, for which the theoretical results are analyzed in comparison with experimental ones. The...
CONSIDÃRATIONS SUR L\\\\\\\'ÃVALUATION DES RISQUES DANS LES PROJETS D’INVESTISSEMENTS
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Constantin ISPAS, Eduard Lucian LOVIN, Dana TILINÃ
Any human action or activity involves taking inevitable risks. Risks in a new product launching, in the conduct of investment etc. are due to market fluctuations and to competition. In principle, the causes of this undesirable phenomenon’s cannot be influenced, but seeks to reduce their...
EVALUATION OF THE FUNCTIONAL STABILITY OF PROCESSING CENTERS WITH CNC
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Viorica CIOBANU, Alexandru DORIN, Nicoleta-Elisabeta PASCU
The behavior in exploitation of processing centers determines their productivity and the quality of manufactured parts. The term of functional stability refers to the maintenance of processing precision in time on the machines-tool with CNC in the prescribed limits, considering the modification...
ADVANTAGES OF NEW ECOLOGICAL IMPACT AND RISK ASSESSMENT MODELS
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Mãdãlina ARAMÃ, Adrian V. GHEORGHE, Corneliu V. RADU, Radu D. STANCIU, Margareta NICOLAU
Ecological impact and risk assessments have become of increasing importance in our daily life. The majority of used methodologies until now have been totally subjectiv. That is why the assessments remained dependent the on initial collected data and on the evaluators background and expertise, a...
METHODS FOR VALUE ANALYSIS INTEGRATED IN A NETWORK FOR TECHNOLOGICAL TRANSFER
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Ioan Dan FILIPOIU, Paul SVASTA, Nicoleta CÃRUÃAªU, Irina GEANTÃ, Cristian Gabriel ALIONTE
In this paper the authors have sought to present the value analysis methods which were the basis for creating a computer network developed under the IN – TECH – TRANSFER and used within the program \\\\\\\\\\\\\\\"Competitiveness and Innovation”. This software tool allows...
EVALUATION DE LA PERFORMANCE DES PROCESSUS COLLABORATIFS EN CONCEPTION DE PRODUITS
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Genoveva TOPLICEANU, Vincent ROBIN, Constantin ISPAS, Philippe GIRARD
The project management has not only to concern resources allocation process to best satisfaction the objectives assigned, but also to promote collaboration between the actors involved in the project. During the project, the project leader will analyze the real state of design conditions and...