Elecromechanics vs mechatronics-points of view
Andrei Andras

Mechatronics–this emerging boundary subject is largely disputed among scientific, business, and engineering collectivities both in the plane of methods and applications, and in the plane of concepts and approaches. From ideas which consider it as a make-up form of electromechanics or deny its scientific emerging character, until apologizing concepts declaring it as a philosophy of intelligent machines engineering of 21st century, a few dozen of concepts and opinions exist in formal and no formal debates among interested collectivities. The paper deals with an overview of these ideas, with pro and contra augments emerged from a particular topic- equipment for mining industry, the latest beneficiary of the topic.

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Linear algebra applications using Matlab software
Cornelia Victoria Anghel

The paper presents two ways of special matrix generating using some functions included in the MatLab software package. The MatLab software package contains a set of functions that generate special matrixes used in the linear algebra applications and the signal processing from different activity fields. The paper presents two tipes of special matrixes that can be generated using written sintaxes in the dialog window of the MatLab software and for the command validity we need to press the Enter task. The applications presented in the paper represent eamples of numerical calculus using the MatLab software and belong to the scientific field „Computer Assisted Mathematics” thus creating the symbiosis between mathematics and informatics.

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Contributions to the improvement of cooling beds mechanism of profiled rolling mils
Marius Ardelean, Erika Ardelean

The cooling beds of rolling mils have a very important role in obtains of a finite product of high quality; thing so which is pointed out better at small profiles rolling mils. These cooling beds assure a conducted cooling of laminates profiles at the same time wish straightening them during the crossing of the cooling-bed fiability, a diminution of exploitation costs. The cooling beds of small profiles rolling mils of SC ISPAT-SIDERURGICA SA Hunedoara is most complex, being formed, beside the classics receive-exhaust reeling-path by a few mechanism like: separation mechanism, the mechanism of taking-over and transversal removal, grouping-removing mechanism. It’s being studied the braking mechanism at the entrance on the cooling-beds. The kinematics and cinetostatic study of this mechanism conducts to dates and conclusions, which can be used forward at the study of component parts of the mechanism using an analysing program with established finite element. Based of results obtained from the kinematics and cinetostatic analyses of the mechanism and the results of feign-modelling is suggested a new solution for the construction of component nod of this mechanism. It must be underlined the fact that, because of the very big length of cooling bed and reduplication of component parts, this thing has a favourable influence concerning the working and the exploitation of the braking mechanism, wish positive influence in global working of the cooling bed rolling mills. The study can be extended for all the component mechanism of this cooling bed.

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Measurement of stratospheric ozone layer thickness using 0.65 Nm resolution micro spectrometer
Klaudija Bašić-Palković, Zoran Mijatović

Results of ozone layer thickness measurements are presented. Instead of expensive Dobson or Brewer spectrometers an UV microspectrometer was used. Obtained results are compared to the results from satellite measurements. This comparison showed agreement inside 10 % in average.

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Optimal equipment programming for realizing an ensemble of electrical overhead lines
Constantin Bărbulescu, Marius Groza, Gabriel Limbean

The main purpose of this paper is to elaborate a calculation program in Pascal language, using Delphi environment. This calculation program is designed to solve the power engineering optimization problems using the method of optimal Hamiltonian path and circuit, solved with the so called "Latin multiplication". For illustrating the use of the algorithm and the calculation program we present a problem of optimal equipment programming for realizing an ensemble of electrical overhead lines.This paper is structured in 4 parts. In the first part of the paper we present the application as a problem of optimal Hamiltonian path and circuit. In the second part of the paper, we determine the optimal Hamiltonian path (circuit) in a graph using the so called Latin multiplication method. In the third part of the paper we present a representative numerical application. In the fourth part of the paper it is described the calculation program.

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Influence of the noise generated by the electrical transformers upon the environment
Constantin Bărbulescu, Vasile Bacria

Often, the electrical transforming stations are located in the proximity of inhabited areas.The electrical transformers from the stations generate noise that affects the residents of these areas.In this paper we will present the results obtained by identifying the sources of noise from the electrical transformers and their typical levels. We will also approach the methods of reducing the acoustic pollution which is generated as a result.

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Inefficient charging for delivered gas by local gas distributors
Siniša Bikić, Maša Bukurov

In this region, especially in Serbia, common belief is that local distributors of gas used by households don’t charge for gas properly. It is suspected that there are two sources for improper ways of gas charging. Local distributors charge for delivered gas only, according to flow rat but not according to gas quality. It is usual that local distributors deliver gas of different quality than one signed in contract. In this work will be considered only one of aspects inefficient charging for delivered gas by local gas distributors, which is connected to variable atmospheric pressure. There is doubt, that local distributors make mistakes during accounting for delivered gas to costumers in regard atmospheric pressure. At the beginning of every investigation, problem has to be located and recognized. Authors are going to collect as much as possible available data, to elaborate and analyze data by scientific methods and to represent conclusions. So, the aim of this work is to diagnose current state and to approve or disapprove above mentioned suspicions. In our region this theme is very interesting, both because of energy efficiency and air pollution control. In this way both consumer and distributor will know, how mush energy they have really spent.

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The state-of-the-art in the rehabilitation of a PIONEER Crane
Cosmin Bledea, Eugen Ghita

The paper is focused on the analysis about the state of stress in the girder of a PIONEER crane with a prescribed vertical loading of 0,75 tones belonging to the thermal power-station Timisoara. The analysis has been performed with a FEA software (COSMOS/M) which is able to conduct to important results regarding the map of stress, especially in areas where high stress concentration are present. There have been automatically combined a wide range of finite elements: shell, brick, beam,truss-cable simulating the different zones of the girder. The combination of the most advanced standard components as well the implementation of the modular product concepts and the state-of-the-art regarding the design of cranes must be in a perfect agreement with the state of stress in the metallic structure. In the end, a comparison between the FEA results and the classical calculus with the strength of materials theory has been performed.

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The assessment of the structural degradation level of an used thermoenergetic pipe made out of 12CrMoV3 Steel, using the metallographical replica method
Andreea Bobic

Generally, the metallographical replica method is applied on the external surface of the energetic pipes in order to assess the structural degradation. This nondestructive method allows to obtain information regarding the grow and sheroidization of carbides, as well as the propagation of cavities leading to cracks. Considering the analysed pipe a thick-walled cylinder, from the theory of maximum tangential unit stress, the permanent deformations appear, firstly, in the neighborhood of the cylinder internal surface. Thereby, the aim of the paper is to evaluate and compare the structural degradation of the external and, respectively internal surface of a pipe made out from 12CrMoV3 steel, with the dimensions of 273x38mm, using the metallographical replica method. The pipe worked at the temperature of 5400C and the pressure of 140 bar, for 44,827 hours. The obtained results showed that the structural degradation level of the internal surface is higher with about 11 – 18 % than the structural degradation level of the pipe external surface. Thus, by applying the metallographical replica method, a certain level of structural degradation of the material external surface is established; the degradation level at the internal surface of the pipe is equal or higher than the one determined on the external surface.

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Monitoring of the solar photovoltaic energy
Cristian Chioncel, Petru Chioncel

This paper presents the adopted solutions of registration the basic solar energy parameters for the Resita, ‘Eftimie Murgu’ University location, respectively around the parallel 450 north latitudinal. This information is necessary to realize photovoltaic installation in Romania. The monitoring system ensures a real time (on-line) registration of the incident solar radiation, the module temperature, ambient temperature as well as electrical parameters: voltage, current, obtained power for a longer period (couple of years). This information allows then a correct estimation of the energy that can be obtained with this kind of installation.

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Implemnetation of the Kalman filter algorithm on a stand with microcontroler
Cristian Chioncel, Petru Chioncel

The experimental stand represents an application to adjust and control the rotation speed of a DC motor with permanent magnet realized with an 80C51 family microcontroller that commands a PWM (Pulse Wide Modulation) source. The user interface is realized in Visual Basic 6. It contains different adjustment modes and posts the state estimation of the process (rotor speed and current of the DC motor). It can be observed good conformity between the estimate values (calculated), and the measured once.

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Applications of laser in control of microdeformations
Vasile Cojocaru

There are two basic types of laser measurement systems the ranging systems and interformetric systems. In the ranging systems the elapsed time between emission and reception of laser pulses are measured. Also the ranging systems make measurements at single points, and need to make measurements at N discreet points to provide N data points. Interferometric systems provide many advantages over laser ranging systems, including higher speed, higher resolution, 3-D deflection data, and a wide variety of static and dynamic engineering mechanics measurements derived from these deflection measurements. Interferometric measurement systems can take many channels of independent measurements simultaneously with a single momentary exposure. This paper traits one interferometric method, ESPI (Electric Speckle Pattern Interferometry) and it is based on the diploma project of author, project do at IUT Bethune, France.

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Fuzzy algorithm used to water debit control to the secondary cooling in continuous casting process
Corina Cunţan, Ioan Baciu

The relised research, reffering to human expert behaviar, show that this have a strong nonlinear behaviar, accompanied by prediction, integration, anticipation and delayed effects and even in adaptation of the real functioning process.The prominencing of languages caracterisation of process and also the interpretation based of experience in commands generation process represent the parameters which can modify the controll properties.The projected Fuzzy algorithms lead to nonlinear controllers. To determine the controlling characteristics was used: Fuzzy Controller PIC 16C74, the appropriate software and ADA 3100 data acquisition board.To obtain a best controlling precision, the process was divided in two parts: start-stop and continuous casting process. For each part was establised the base rules and the membership functions which lead to obtain the controll surfaces and statical characteristics.

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DICOM Overview
Dragan Dinu, Dragan Ivetic

The paper introduces preliminary results of our research on DICOM – JPEG 2000 coupling: DICOM standard. DICOM standard defines method for transferring digital images of various formats and associated data between devices manufactured by various vendors. PACS (Picture Archiving and Communication System) inside a hospital that can interface with other informational subsystems is based on this standard. DICOM standard is applicable to a network and/or to an off-line media environment. These features of DICOM standard manage communication between PACS in different hospitals. That means that if patient is transferred to another hospital his new physician can access patient’s medical records over the network. They also manage online accession to medical records from physician’s home. The standard supports operations that are based on other computer protocols (TCP/IP, ISO 9660, etc). Digital image and associated data are coupled in a single DICOM file. Image pixels are encapsulated inside this file. Format of image can be native DICOM format and/or some other lossless or lossy standard (jpeg, jpeg 2000, etc). At the end, development of PACS system of Hospital for chest-diseases which is based on DICOM standard is discussedi.

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Technical solutions concerning the updating of Reşiţa’s waste water plant
Mihaela Frigură – Iliasa, Flaviu Mihai Frigură – Iliasa

The updating of all equipment existing in waste water treatment plants is a major priority for all Romanian public water suppliers (including those of Reşiţa) which have to insure a low level of environmental pollution. In order to obtain a higher quality level for the resulting cleaned water and to insure the performances and the safety required by those strategic industrial objectives, new flexible and reliable command strategies have to be applied both to existing electric equipment already involved and new electric equipment which could be introduced in the future. This paper presents an original technical solution concerning that type of command used for all electrical equipment inside the plant (pumps, valves, etc.).

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The problems of labor safety and health protection in construction – EU experiences and standards and legal regulations in the Republic of Serbia
Dusan Gavanski, Mirjana Laban

Within the activities of the European Agency for Safety and Health at Work in 2004 a special attention was paid to the field of constructions with an accent on a one-week action “Building in Safety”. The research covered all stages of the construction process from planning to exploitation of a structure. Since in our country the new Low on safety and health at work is about to pass the procedure in the Parliament, and according to the tendency of harmonization of regulations and codes with EU countries, it is considered that it is necessary to carry out a comparative analysis of knowledge in this area in European countries and future legal measures and technical regulations in Serbia consequently. The aim of this paper is contribution to viewing the variety of problems and a unique approach to their solution in the direction of further improvement of sustainable development and humanization of working environment.

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Aspects concerning the mathematical statistical modeling of CO2 variation in soft drinks bottled in polyethylene terephthalate plastic containers
Mirel Glevitzky, Gabriela-Alina Brusturean, Doru Dumitrel, Delia Perju

The quality of the soft drinks found on the market is determined by a series of physical, chemical, biological and mechanical factors, which cause important organoleptic changes. The present study is necessary because of the problems that the soft drinks producers have as a consequence of CO2 losses through the walls of polyethylene terephthalate bottles (PET). The experimental investigations were centered upon measuring the CO2 over a period of time for several soft drinks stored in polyethylene terephthalate bottles. In this paper, starting from the experimental determinations performed, a series of mathematical statistical models are elaborated. They emphasize aspects concerning the CO2 variation of the samples as a function of their volume and time. The conclusions achieved can be used both for the improvement of the quality of soft drinks and for the forecasting of their optimum time of utilization.

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Construction and assembling optimization of power equipment
Marius Groza, Constantin Bărbulescu, Gabriel Limbean

The main purpose of this paper is to elaborate a calculation program in Pascal language, using Delphi environment. This calculation program is designed to solve the power engineering optimization problems using the critical path method. For illustrating the use of the algorithm and the calculation program we propose an application from power engineering: a 400 kV electrical overhead line section realization. This paper is structured in 4 parts. In the first part of the paper we present the application as a problem of critic path. In the second part of the paper, we determine the critic path in a program graph and time reserves. In the third part of the paper we present a representative numerical application. In the fourth part of the paper it is described the calculation program.

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Topological characterization of electro-discharge machining using motif combination
A. Iakovou, G. Petropoulos , Cornelia Anghel

In the present study the method of surface motif combination is applied to Electro-Discharge Machining surfaces. By statistical mean, as analysis of variance and response surface methodology, predictive models for the motif parameters are developed in terms of the machining conditions. Using these models the appropriate conditions for successful finish can be selected, as well as functional surface characteristics are quantified.

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The transversal ventilator, generating of ideal aerodynamic field for agricultural machinery of harvesting and conditioned
Ioan Marcel Indre, Radu Ioan Tărcăiet, Constantin Ştefan The theoretical studies and experimental researches effects confirm that the transversal ventilator, through the structure and the quality of the aerodynamic field, which is generated, it becomes the type of ideal ventilator for agricultural machinery of harvesting and conditioned cereal mixtures.
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Comparative analysis of some brushless motors based on catalog data
Anton Kalapish, Dimitar Sotirov, Dimitrina Koeva

Brushless motors (polyphased AC induction, synchronous and brushless DC motors) have no alternatives in modern electric drives. They possess highly efficient and very wide range of speeds. The objective of this paper is to represent some relation between the basic parameters and magnitudes of electrical machines. This allows to be made a comparative analysis and a choice of motor concerning each particular case based not only on catalogue data or price for sale.

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eLearning platforms
Sandra Hirschler,Gabriela Felicia Georgevici, Gilbert-Rainer Gillich

The work presents a modern instrument for learning and understanding physical phenomena, implicit special phenomena witch appears in the study of “Machine dynamics”, using Java applets. This kind of programs is preferred, because Java is free, is good supported by various browsers and is very flexible.

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Stimulus generator for spice simulations using graphical programming language
Valentin-Ioan Maranescu, Catalin Caleanu

The paper presents a virtual instrument designed in graphical programming language LabView. This virtual instrument is a spice stimulus generator used for mixed analog and digital circuit simulations. Innovatory for this tool is the time scaling and rescaling possibility also for digital stimulus not just for analog stimulus. Transition level editing is avoided, sequences in stimulus being generated byte by byte. Digital sequences can be synchronized with analog signals if needed. Editing the stimulus is faster just filling a table with hex codes. The stimulus can be generated serially, and/or parallel on 1, 2, 3 or 4 bytes. For implementation, spice stimulus format *.stl under Orcad 10.3 was analyzed.

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Geometrical (Degree 0) Modelling of a FP3+3×RTR+MP3 type parallel topology robotic guiding device, using the „Pair of Frames” (PF) Concept
Călin Micloşină

The geometrical (degree 0) model of a parallel topology robotic guiding device represents the position-orientation matrix of the mobile platform (MP) versus the fixed one (FP); this model refers to generalized displacements. The kinematical scheme of a FP3+3×RTR+MP3 type mechanism is presented, as well as the manner of choice of the attached pair of frames (PF) to the links. In the case of direct geometrical modelling, for certain displacements of the actuated translational joints, the position-orientation matrix of the mobile platform versus the fixed one is determined. For inverse geometrical modelling, the position-orientation matrix of MP versus FP is known and the displacements of the actuated translational joints are determined.

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Calculation of the shading in the PV – Generators design
Miroslav Petkov

Many solar collection devices are fixed or move with only limited freedom. As a result the collection apertures do not face directly toward the sun at all times. Therefore the photovoltaic (PV) generators have to be able to collect as more solar energy as possible.The magnitude of the beam component of direct normal radiation is therefore insufficient information to estimate the energy intercepted by solar collector surface. In this paper the virtual motion of the sun is given and the calculation of the shading is also described.

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A proposed method to determine the adherence for the layers made out of thermal sprayed materials on internal cylindrical surfaces
Adrian V. Petrica, Mircea Megheles

The paper presents an investigation method for the adherence of the layers made out of thermal sprayed materials on the inner surface of some parts. The base material is made of steel. The deposition procedure was the electric arc thermal spraying, flame spraying asnd plasma spraying and the filler materials used were: copper, brass and aluminum bronze. The proposed method analyses the adherence force by measuring the shear unit fracture stress of the deposited layers.

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Mathematical modeling of the thermical regime in the continous casting process
Monika Erika Popa, Imre Kiss, Adrian Danciu

Continuous casting is one of the prominent methods of production of casts. Effective design and operation of continuous casting machines needs complete analysis of the continuous casting process. In this paper the basic principles of continuous casting and its heat transfer analysis using the finite element method are presented. In the analysis phase change is assumed to take place at constant temperature. A front tracking algorithm has been developed to predict the position of the solidification front at each step. Finally, examples that are solved by the proposed algorithm are discussed. The results show that there is a good agreement between the method developed in this work and other previously reported works.

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The study of plate-type electrostatic precipitators electrical supplies
Nicolae Gabriel Popa, Corina Cunţan, Ovidiu Tirian, Dorin Roiban

Stricter environmental legislation in many countries is producing standards governing the emission of fine particles to the atmosphere from all sources. The industrial separating particles from process streams have numerous methods with different principles. In electrostatic precipitators is used electrical charge of dust particles.There are many aspects of pollution control in both solid and liquid phase using electrostatic precipitators.The operation of plate-type electrostatic precipitators is closely related to its electrical energization, to obtain high collection efficiency with low electrical energization consumption. The paper analyze the traditional direct current energization, the intermittent energization, the pulse energization and the switched mode at high frequency power supplies of plate-type electrostatic precipitators sections.

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Shaft position influence on technical charasteristics of universal helical speed reducers
Мilan Rackov, Zeljko Kanovic, Sinisa Kuzmanovic, Ruzica Trbojevic

Purchasers of speed reducers decide on buying those reducers, that can the most approximately satisfy their demands with much smaller costs. Amount of used material, ie. mass and dimensions of gear unit influences on gear units price. Mass and dimensions of gear unit, besides output torque, gear unit ratio and efficiency, are the most important parameters of technical characteristics of gear units and their quality. Centre distance and position of shafts have significant influence on output torque, gear unit ratio and mass of gear unit through overall dimension of gear unit housing. Thus these characteristics are dependent on each other. This paper deals with analyzing of centre distance and shaft position influence on output torque and ratio of universal two stages gear units.

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Hydrogenerator stator rehabilitation methods
Mihaela Răduca, Eugen Răduca, Iancu Tătucu

In this paper are presented the hydrogenerator stator rehabilitation methods, stator forming the followings subassemblies: frame, stator core, stator winding, terminals and terminals box. The stator rehabilitation are execute after the guaranteed time established by supplier firms or if in function time was appear different defects, defects that can out in function of hydrogenerator. Stator rehabilitation can be make through changing stator subassemblies parts or through by replacement existent subassemblies with new subassemblies compatible with hydrogenerator.

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Hydrogenerator rotor rehabilitation methods
Mihaela Răduca, Eugen Răduca, Iancu Tătucu

In this paper are presented the hydrogenerator rotor rehabilitation methods, stator forming the followings subassemblies: rotor, shaft, rotor bracket, rotor rim, rotor poles, rotor winding, rotor connections, and fans.The rotor rehabilitation are execute after the guaranteed time established by supplier firms or if in function time was appear different defects, defects that can out in function of hydrogenerator. Rotor rehabilitation can be make through changing rotor subassemblies parts or through by replacement existent subassemblies with new subassemblies compatible with existing hydrogenerator.

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Modified measurement method for determination of the hydrogen content in ferritic arc weld metal
Eugen Sallai, Ernst-Rainer Sievers, Doina Frunzăverde

During the welding processes hydrogen from surrounding atmosphere is absorbed in atomic form in the molten pool. While following cooling and solidification of the material, most of the atomic hydrogen is pushed out, but a small part remains trapped into the crystal structures. It tends to accumulate by diffusion in places with material defects, building up enormous pressures that lead ultimately to crack formation. The quantity of hydrogen accumulated in the welding seam can be measured by the method described in EN ISO 3690/2000. The present paper presents the test results obtained by the authors by trying to adapt the procedure described in EN ISO 3690/2000 to several welding procedures, in order to obtain satisfactory results.

An educational multi – user measurement system (EMUMS) 279
Miloš Slankamenac, Milan Nikolić, Kalman Babković, Goran Stojanović, Ivan Mezei, Mirjana Damjanović

The goal of the project educational multi-user measurement system (emums) has been to produce specification, design and implementation of an educational measuring system that is used for measurement of non-electrical values, such as temperature, pressure, fluid movement, etc. In this paper we present overview of the project. We also present some design and implementation details, the features of the final product and experience with students.

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THE device for communication in the tool for measurement in boreholes
Miloš Slankamenac, Miloš Živanov

In this paper an implementation and test of the device for communication between Telemetry system and Surface unit with the tool for measurement of pipe diameter, fluid velocity and direction of flow in the borehole (Calliper-Fullbore Flowmeter - CFF) are presented. This communication is done according to SIPLOS (Simultaneous Production Logging String) protocol and it is used by Hotwell company [1] as a part of a larger system for borehole investigations..

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Dynamic study of synchronous machine electric drive
Dimitar Spirov, Svilen Rachev

The dynamic behaviour of the fan blower synchoronous machine drive have been studied in the paper. The equations for the voltages of the synchoronous machine windings are presented in a coordinate system which rotates at the angular speed of the rotor. The mechanical equipment is presented by means of a single-mass dynamic model. The derived system of differential equations is transformed and solved using suitable software product. The results obtained for rotation frequency and electromagnetic torque motor in the courses of different values of rated supply voltage and of different initial resistant moment of the mechanism have been graphically presented. Conclusions from the results obtained have been done.

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Influence of induction machine and mechanism parameters on starting transient processes in case of constant load conditions
Dimitar Spirov, Svilen Rachev, Pencho Vladimirov

Two-phase induction machine dynamic model in a coordinate system which rotates at synchronous speed and one-mass dynamic model of mechanism driven in relative units describing transient processes when starting an induction machine in case of constant load conditions are developed.The influence of equivalent circuit parameters of induction machine and mechanism parameters on impact currents and torques and starting time of common used induction machines is studied by means of design of experiment method.

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Delivery of a methodology of choose of drilling installations for ore mines
Sorina Stanila, Petru Cor, Iosif Gruneantu

In the paper the main factors influencing the chose of drilling jumbos and the determination of efficiency of drilling process is presented. The general principles and methodology of establishing the main parameters of drilling in different ores is discussed. The main criteria of choosing the drilling jumbos are presented.

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Microprocessor controlled static converter
Stefan Szabo, Ioan Ruja

This paper wants to demonstrate a way of implementing a microcontroller into an DC motor speed control loop. The static power converter is a fully controlled rectifier bridge, using standard SCR's. The bridge's control signals are supplied by the microcontroller and are phase-angle or burst types. The automation loop contains a software PI-style regulator. All the experimental results shows that this aproach is flexibile enough to be used on a large scale.

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Technique to reduce the shaft torque stress at an induction machine
Adrian Tulbure

For the active attenuation at load stress in the drive shaft, the control system should receive as input signal the instantaneous shaft torque value. In this context an intelligent observer for shaft tongue of mains operatea induction machine, which is able to responding by variation of LIF (Load Input Function)[1] must be developed. Extensive computer simulation prove the effectiveness of the proposed solution. In order to obtain a practical validation, the stimulated regulator has been designed and tested in the Institute of Electrical Engineering in Clausthal/Germany [2]. This paper contains following parts: Developing the mathematical model, Practical realisation, Simulations and measurements, Evaluating the control solutions and Conclusions.

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The experimental determination of the maximum continuos operating voltage for a ZNO based varistor
Zeng Eva, Popa Cristian Mihai

ZnO based varistors are today frequently used for surge arresters. In order to obtain a better behavior of that piece of equipment, it is very important to know the continuous voltage limits accepted. This goal could be achieved only by making some experiments to evaluate the thermal limits of a certain varistor. This paper presents some original experiments made by the authors at the “Genie Electrique” Laboratory of the “Paul Sabatier” University in Toulouse, France. These experiments are original because they are taking in consideration the environmental temperature too, and they

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