Arhivă — Seria D

1

DYNAMICS OF THE ORTHOGLIDE PARALLEL ROBOT

Damien CHABLAT, Philippe WENGER, Stefan STAICU

Recursive matrix relations for kinematics and dynamics of the Orthoglide parallel robot having three concurrent prismatic actuators are established in this paper. These are arranged according to the Cartesian coordinate system with fixed orientation, which means that the actuating directions are normal to each other. T…

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2

A DEVELOPING A MATHEMATICAL MODEL

Tudor CÃSÃNDROIU, Mihai POPESCU, Gheorghe VOICU

In this paper, a mathematical model of separation of the seeds on plane sieves is developed by using for the first time the theory of the dimensional analysis. This model allows anticipating the coefficient of separation of the “small seeds”, which evaluates the efficiency of the separation performed by the plain sieve…

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3

THE VARIATION OF THE CHARACTERISTICS OF THE IDEAL GAS FLOWS AS A FUNCTION OF MACH NUMBER CONSIDERING TEMPERATURE GAS PROPERTIES VARIATION

Dan RACOÞI, Corneliu BERBENTE

The temperature, pressure and density variation with the March number is described by the gas dynamical functions. These functions are usually deduced from the hypotheses of the constant adiabatical exponent. A systematic method is described, based on the energy conservation equation and the isentropic flow equation ( …

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4

RESEARCHES REGARDING QUALITY OF THE WELDED JOINTS OBTAINED BY APPLYING THE TECHNIQUES OF WELDING RENEWAL TO COMPONENTS FROM THE ENERGY INDUSTRY MADE F

Dumitru - Titi CICIC, Gheorghe SOLOMON, Gabriel IACOBESCU, Corneliu RONTESCU

The main techniques of renewal by welding applicable to energy equipments components are presented in this paper, as well as their limitations, the experimental program, the obtained results and the main effects they have compared to the classical variant of renewal by welding followed by post weld heat treatment.

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5

FATIGUE LIFE PREDICTION OF A CRACKED LAP SPLICE SPECIMEN USING FRACTURE MECHANICS PARAMETERS

Pedro M.G.P. Moreira, Paulo F.P. de Matos, ªtefan D. Pastramã, Pedro P. Camanho, Paulo M.S.T. de Castro

One of the main problems of aeronautical structures is the onset and growth of damage due to fatigue loading. This phenomenon is accentuated in areas of stress concentration, for example in the connection of components, such as the riveted joints of fuselage panels. This paper is focused on the study of a single-lap sp…

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6

THE ACOUSTIC MULTI-CHAMBER MUFFLER PERFORMANCES

Ovidiu VASILE, Nicolae ENESCU

This paper investigates the acoustic performance of a reactive silencer (muffler) for three special cases using numerical and experimental techniques. The plane waves based models such as the transfer matrix method (TMM) can offer fast initial prototype solutions for silencer designers. In this paper, the principles of…

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7

WHEEL/RAIL FRICTION POWER IN CURVED TRACK

Andrei TUDOR, Nicolae SANDU Elias TOUNTAS

The paper analyses the longitudinal, lateral and spine creepages and the friction power for the wheel-rail contact on curved track. The geometry of UIC49 rail and S78 wheel and their contact are shown as an exemple. The contact area can be of elliptic or rectangular form, as a function to the wheel position relative to…

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8

MATHEMATICAL MODELING AND NUMERICAL SIMULATION OF PROCESSES INSIDE A TURBO-ENGINE THAT USES LANDFILL GAS

Valentin SILIVESTRU, Romulus PETCU, Valeriu VILAG, Corina MANDIS, Dan ROBESCU

In Romania, the landfill gas, obtained through fermentation of organic matter contained in waste materials, is burned without an energetic utilization. This fact imposes the adoption of solutions for the energetic capitalization of these gases. On the other hand it is known that the engines used in aviation, after the …

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9

OPTIMAL DESIGN FOR THE INTERIOR SHAPE OF A ANNULAR DIFFUSER WITH DIVERGENT CAREENING CONSIDERING THE MINIMUM WHOLE LOSS PRESSURE

Mihai D.L. ÞÃLU, ªtefan D.L. ÞÃLU

In this paper is presented a new mathematical model and a numerical programme in Mapple 11 programming language, for optimum design of the interior shape of a hydraulic annular diffuser with interior divergent careening.\r\nThe mathematical model was determined to respect the minimum values of the whole loss pressure. …

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10

MANAGEMENT VALUATION AS AN INTANGIBLE ASSET

Dragoº Mihai IPATE, Iuliana PÂRVU

Knowledge is the main source of value and competitive advantage in the new economy. Due to the impact of the intangible assets upon the performance of organizations, their managers need adequate models which can help them evaluate the efficiency of investing in non-corporeal assets because the decisions based on the tr…

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11

FOREX AND THE LIBERALIZED FINANCIAL MARKET

Oana DAVID, Beatrice LEUSTEAN

The present paper is trying to introduce the meaning, method and mechanism of Forex market, as well as the participant’s risks and opportunities in this sort of transactions. The authors also briefly present the role of the continuously liberalizing financial market into the environment of the global economic growth, a…

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12

TECHNOLOGICAL DIFFERENTIATION AND PERFORMANCE MEASUREMENT ON SUPPLIER INTEGRATION IN NEW PRODUCT DEVELOPMENT

Gheorghe MILITARU

This paper summarizes what the academic literature has to say about the integration of suppliers in new product development and contributes with an empirical research to demonstrate that technological differentiation, business performance, the innovation and the communication between company and its suppliers is positi…

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13

THE TIME AS A RESOURCE

Corina – Ionela DUMITRESCU, Sorin IONESCU

We propose in this paper an approach of time as an important resource that generates competitive advantages for a company. There are also important aspects reviewed of the time management because, from our point of view, these aspects are decisive for the understanding of the role of time in management. The originality…

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14

EXTENSIVE AREA TO APPLY THE VALUE OF ENGINEERING (I)

Ion IONIÞÃ, Liliana MOGA

While the Value Engineering is presently applied in this country, as well as worldwide, mainly in the design/redesigning of products, especially to those of industrial type, the research that we have undertaken in the recent years has provided us to develop new methodologies for expanding the area of application of …

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