Abstract 

Rare-earth magnets which are the best solutions for PMSM rotors are expensive which makes that other types of motors are used in the applications. The solution of the replacement of these motors with PMSynRM that use low-cost type of ferrite magnets becomes more tempting lately. This paper proposes two different types of low-cost ferrite solutions: first a V permanent magnet assisted synchronous reluctance rotor (VPMSynRM) and the second a permanent magnet synchronous rotor with flux concentrator (PMSM-FC) as an alternative solution to the rare earth inserted tangential permanent magnet synchronous motor (PMSM). For the first situation, this paper proposes two topologies of PMSynRM: with one row and respective two rows of flow barriers, equipped with ferrite magnets Finite element (FEM) approach has been utilized to show the performance of the proposed rotors. The purpose of the proposed solution is to replace only the rotor of such a PMSM that is already in production, so the size of the stator and the number of windings will remain unchanged. Finally, for the PMSM-FC, the experimental results have been shown. This one is considered competitive, taking into account the resources required for a limited-series manufacturing. The motivation of this study is to reduce the cost of the rotor by changing the type of PM and by the choice of suitable rotor geometry.

Abstract 

This work presents a new vision on the diagnosis of railroad Automatic Block Signal Installations (ABS), using the current modern technologies that involve mobile devices or personal computers. The ABS installation is the system of signals between two consecutive railroad stations, stations centralized either electrodynamically (with electromagnetic relays) or electronically (using computers). The system of signals ensure the command and control of traffic train. Currently, failure diagnosis of such installations is done by the staff working in the Signals, Centralizations, Block (SCB) department of the railroad company. The diagnosis time depends on the professional qualifications of the staff (detailed knowledge of the installation’s functioning principles, of the electrical diagrams and related installations), on the practical diagnosis and recovery competencies. A long diagnosis time causes train traffic delays which, in turn, cause passenger discomfort and losses for the transporter companies. In this work we present diagnosis charts for two types of failures of the ABS installation: Failures of the 220 V power circuits in the ABS boxes, and failures of the Transmitting Relays (TR or T) power circuits. The diagnosis charts and their software implementation assist the maintenance staff in quick detection the failure causes for these types of ABS installations. This solution leads to shorter train delays, higher rail traffic security, and to the optimization of the transport services.

Abstract 

We have been listening for a long time to the wide functionality that industrial automation technologies can offer for improving the processes and adding security to the plants and the parts of them. However the price and an unstable market have restricted the deployment of such systems. Nowadays, companies offer too technology-dependent solutions which do not cover user demands completely. Meanwhile, papers from the literature focus on small innovations on specific parts of the industrial automation systems, which do not consider integration and deployment issues, in order to present practical designs [1]. The system presented in this work considers user requirements, including novel advances, all in an integral automation solution suitable for thermal treatments. The modular nature of the architecture allows direct adaptation to specific cases using standard technologies, and a proposal of an IP-based network for connecting the main automation module with the rest of plant. The main purpose of the entire plant is to monitor and control in real-time the temperature of the parts inserted into a resistive furnace. The software is based on m-files that contain the source code that calculates the control coefficients for the next step for ventilation and heating, it verifies the failures that could occur and creates a matrix of the coefficients, in order to make graphics.

Abstract 

The paper deals with a modern solution to measure and analyses selected parameters of any electric motor. A virtual instrument with multiple options for selecting the analyzed parameters is described. The values of motor measurement voltages, currents and speed are read from a specified folder. With the virtual instrument presented in this paper it can be see the motor currents, voltages and speed waveforms and from the acquired data and recorded a set of parameters are computed. Boolean selector determine which signals are selected from the original seven signals (three current, three voltages and speed). It can be extract portions of data from the input signals. The extract portion is defined by begin of the offset (point of start) and the length (end the extraction). This instrument allow timing and transition measurements such as: pulse duration (pulse width), duty cycle (duty factor), preshoot (%), overshoot (%), slew rate. Also this virtual instrument allow to find the first highest (maximum) and the lowest (minimum) point in a set of values in signals of currents, voltages or motor’ speed and find the time of the maximum and minimum values so determined. Knowing these values can be determined the range from the lowest point to the highest point in a set of motor’s start current and voltage.

Abstract 

The aim of this paper is to identify an engineering method to study and to optimize the process of treating the wastewaters from the repairs locomotives industry in terms of quality, cost and environmental impact. The main purpose of this paper is to show how the control systems allowed us to investigate the environmental aspects of a wastewater treatment plant. The final issue is to optimize the process in terms of quality which means to decrease the cost and environmental impact. There are few steps to obtain the final issue. The first step is to establish the flux diagram of the wastewater treatment plant activity in the context of repairing locomotives process. The second step is to define this activity as a sum of processes according with ISO 14001 Standard, aimed to identify the interaction between this processes. To do this must be described the control system of a wastewater treatment method based on Dissolved Air Flocculation (DAF), used to treat the waste waters results from the locomotive repairs activity. A case study was made on a pumping station to illustrate the influence of the control system on this activity. All these sentences were made with environmental tools like: ad-hoc methods and control list methods, Environmental Systems Analysis (ESA) tools, critical synthesis of the processes and theirs modeling, observation and the experiment and statistic calculus. The result of this work is a work procedure in the activity of control quality of the repairs activity, being a practical implementation. The theme is completely original and responds to an actual practice of Environmental Management System.

Abstract 

The paper presents, in the firs part, the importance of the steam generator in the operation of power plants, especially, the importance of the air preheater, the last heat exchange surface on the route of the flue gas, with all physical phenomena produced, which lead to the shaping of the physical model. Then is presented the model in relative units imposed by the literature. The paper proposes the development of a mathematical model in absolute units and the simulation the operation of the air preheater of the steam generator. The theoretical model proposed is implemented in Matlab-Simulink obtained simulations in dynamic regime. In order to validate de model, the simulation results were compared with the parameters measured values of the installations during the real time function. The model wants eliminating the major recalculation sequence of parameters at each step – the patterns in relative units the entire set of coefficients are determined and entered into the model according to the parameters achieved in the previous reference system and meet operating values taken as the basis in developing the work. The approach of such a study is justifies by the development and use of computer technology and digital media communication in dynamic analysis of energy processes.

Abstract 

HID lamps are wide used in lighting systems, also in indoor and outdoor applications. The ballasts necessary for their normal operation could be magnetic or electronic and in the last decade we assist to a debate on which is a better option, the dimming capabilities being one of the most claimed advantages of the electronic ballasts. But, in the last years, several lower cost solutions for getting dimmability with magnetic ballasts have been reconsidered. In this paper, the possibility to dim lamps trough the classical voltage amplitude modulation by means an autotransformer is explored. This solution can be cheaper, robust and most suited for the low budget Africa’s lighting systems. To understand the context, two lighting systems from Antananarivo, capital of Madagascar, and Dakar, capital of Senegal, have been depicted. Experimental tests have been performed on 250 W HID lamps, a High Pressure Sodium (HPS) and a Metal Halide (MH), operated by Very Low Loss magnetic ballast. The range of the voltage modulation has been from 160 V to 250 V and the power consumption, the light output and the harmonics content have been recorded. The energy saving per lamp by dimming to 160V is about 50 to 55% for the considered lamps.

Abstract 

This paper aims to present some problems concerning the electric power management systems of aircraft. In the first sections are presented some converters topologies used on aircraft, principles and digital control schemes for these converters. In the next sections there are presented architecture principles of power management systems using these kinds of converters. Converters are mainly used to adapt the power parameters of the on board sources to the aircraft consumers necessities. On More Electric Aircraft, with VSVF generators, these converters are used to feed the aircraft power buses, each consumer being coupled to the corresponding power bus. Taking into account the great importance of some consumers, it is necessary to ensure its feeding even a part of the on board power sources fails. In this purpose one use by one hand redundant power buses and by other hand the electric power management systems. These systems ensure both the coupling of the power sources to the power buses according to the power necessities and also commute the consumers feeding between the buses using different control strategies. The control strategies consider the available power sources at a time, the consumers it has to be fed and priority order of the consumers.

TRANSITOIRES ET REGIMES PERMANENTS DANS LES CIRCUITS R C INDUCTANCE NON LINEAIRE SOUS TENSION SINUSOIDALE Marian Badea

NOUVEAUX MODELES ET ALGORITHMES ASSOCIES AUX COUPLAGES MUTUELS EN REGIME HARMONIQUE, COMPATIBLES AVEC LA METHODE NODALE MODIFIEE Dumitru Topan, Lucian Mandache

CORRECTIVE SCHEMES FOR VOLTAGE STABILITY ANALYSIS USING TWO DIFFERENT INDICATORS Leonardo-Geo Manescu

LOSS REDUCTION AND SECURITY ENHANCEMENT IN LOADED POWER SYSTEMS
Leonardo-Geo Manescu

STUDY OF THE ELECTROSTATIC FIELD WITH OPEN BOUNDARY USING THE FINITE ELEMENT METHOD AND KELVIN TRANSFORMATION Saul Pasare

A STUDY OF FORCE IN A STEADY MAGNETIC FIELD WITH ASYMPTOTIC BOUNDARY CONDITIONS Saul Pasare

MODELLING AND ANALYSIS OF TEMPERATURE CONTROL PROCESS; A HYBRID PETRI NETS APPROACH Mircea Adrian Drighiciu

A NUMERICAL TWO-TIME APPROACH FOR RF-IC ANALYSIS

Mihai Iordache, Lucia Dumitriu, Grigore Stamatescu

MULTI-LAYERED SPHERICAL MAGNETIC SHIELDING

Branislav Kuzmanovic, Kemal Hot, Dubravko Zigman

VERTICAL DIAMAGNETIC LEVITATION ARRAY WITH EXTENDED STABILITY AREA

Emil Cazacu, Alexandru Stanciulescu

THE MAGNETIC FIELD AND MAXWELL’ EQUATIONS RESULT OF THE COULOMB LAW, RELATIVITY AND QUANTUM MECHANICS

Gheorghe Mihai

THE UNITARY THEORY OF THE ELECTRIC POWERS Gheorghe Mihai

MAGNETIC INDUCED CURRENTS AND VOLTAGES IN DE-ENERGIZED CONDUCTORS BY THE HV TRANSMISSION O/H LINES UNDER NORMAL AND SHORT-CIRCUIT CONDITIONS
George A. Florea, Adrian-Mihail Lipan

FAST SOLVING OF A LINEAR PARAMETRIC MODEL OF A BAW RESONATOR Miruna Nitescu, Florin Constantinescu, Al.-G. Gheorghe, Lucia Dumitriu

ANALYSIS AND SIMULATION OF AN ELECTRIC DRIVING INVERTER USED IN ELECTRIC URBAN TRACTION Ioana-Gabriela Sîrbu, Petre-Marian Nicolae

TESTS, RECORDINGS AND NUMERICAL PROCESSINGS OF DISTORTING AND UNBALANCED OPERATING REGIMES OF A SYNCHRONOUS GENERATORS
Petre-Marian Nicolae, Ileana-Diana Nicola

REGARDING TO THE CONTROLLED CLOSING OF THE CIRCUIT BREAKERS Maricel Adam, Adrian Baraboi, Catalin Pancu

ARTIFICIAL INTELLIGENCE CONTROLLED SYSTEM FOR THE MONITORING OF ELECTROMAGNETIC POLLUTION Catalin Pancu, Adrian Baraboi, Maricel Adam

SEMI-PASSIVE VIBRATION CONTROL: PRINCIPLE AND APPLICATIONS Daniel Guyomar, Kaori Yuse, Thomas Monnier, Lionel Petit, Elie Lefeuvre, Claude Richard

THE MODERNIZATION OF A STAND FOR MEASUREMENT AND TEST OF RESISTIVE TENSILE STAMPS Eugen Raduca, Iosif Debelka, Cosmin Campean, Mihaela Raduca

OPTIMISATION INFORMATISEE DE LA CONCEPTION DES TRANSFORMATEURS DE HAUTE FREQUENCE Auguste Ndtoungou, Paul Makanga, Igor Sabatin

EMC AND RELATED PROBLEMS IN THE IMPLEMENTATION OF URBAN TRAFFIC ANAGEMENT AND PUBLIC TRANSPORT MANAGEMENT SYSTEMS Marius Minea, Angel Ciprian Cormos

CONSTRICTION RESISTANCE OF BANDWIDTH REDUCTION Grigore A. Cividjian

METHODS AND CIRCUITS FOR POWER ARC TEST IN AC CURRENT OF THE SIMPLE AND DOUBLE INSULATOR SETS WITH COMPOSITE MATERIAL FOR AERIAL ELECTRIC LINES
George Curcanu, Constantin Iancu, Corneliu Chiciu

DYNAMIC ELECTROMECHANIC CHARACTERISTIC OF DC ELECTROMAGNETS WITH NULL STARTING FLUX Eugen Hnatiuc, Adrian Plesca, Bogdan Hnatiuc

DYNAMIC ELECTROMECHANIC CHARACTERISTIC OF DC ELECTROMAGNETS WITH NON-NULL STARTING FLUX Eugen Hnatiuc, Adrian Plesca, Bogdan Hnatiuc

APPROXIMATING EXPRESSIONS FOR THE INDUCTANCE AND THE FORCE OF A CYLINDRICAL COIL WITH STRAIGHT FERROMAGNETIC CORE Zaharinka Gergova, Ivan Yatchev, Alexander Alexandrov

TRANSFORMER DIAGNOSIS CORRELATING DGA WITH PD MEASUREMENT RESULTS
Dorin Popa

ESTABLISHING THE EQUIVALENT OVER-TEMPERATURE IN POWER TRANSFORMERS
Adrian Munteanu, Elena Helerea, Catalin Mihai

MONITORING OF THE SPECIFIC PARAMETERS OF AN ELECTRIC SYSTEM, BY USING A MICROCONTROLLER EXPERIMENTAL SYSTEM Virginia Ivanov, Sergiu Ivanov

L’ARCHITECTURE ELECTRIQUE ET ELECTRONIQUE Maria Cristina Cristescu

CONCERNING THE RESULTS OF NON-DESTRUCTIVE TESTING OF SOME ALUMINIUM ALLOYS
Maria Brojboiu, Marin Popa

AN OPTIMIZED DESIGN SOLUTION OF AN OLEO-PNEUMATICALLY ACTUATION DEVICE FOR HIGH POWER CIRCUIT BREAKERS Eleonor Stoenescu, Maria Brojboiu

A STUDY ABOUT THE AC SWITCHING REGIME OF A SINGLE-PHASED TRANSFORMER CHARACTERIZED BY A NON-LINEAR MAGNETIZATION CURVE WITH PIECEWISE-LINEARISED HYSTERESIS CYCLE  Cristian-George Constantinescu, Constantin Strimbu

BASIC TOPOLOGIES OF DIRECT PWM AC CHOPPERS Dan Floricau, Mariana Dumitrescu, Ioan Popa, Sergiu Ivanov

A SIMPLE METHOD OF TORQUE RIPPLE REDUCTION FOR DIRECT TORQUE CONTROL OF PWM INVERTER-FED INDUCTION MACHINE DRIVES Sanda Victorinne Paturca, Aurelian Sarca, Mircea Covrig

A CASE STUDY REGARDING THE IMPLEMENTATION OF AN ELECTRIC BICYCLE USING RELUCTANT MOTORS Viorel Trifa, Calin Marginean, Liviu Zarnescu

ASPECTS REGARDING THE ENERGY EFFICIENCY AND HARMONIC SPECTRUM AT DRILLING WELLS Ana Iacob, Marian Duta, Sebastian Popescu

POSITIONING SYSTEMS FOR SOLAR PANELS PLACED IN ISOLATED AREAS
Laurentiu Alboteanu, Gheorghe Manolea, Florin Ravigan

MODELLING OF THREE LEVELS CONVERTERS USED IN ELECTRIC TRACTION
Daniel Cristian Cismaru, Doru Adrian Nicola

THERMAL ANALYSIS OF A PERMANENT-MAGNET TUBULAR MACHINE
Fabrizio Marignetti, Ioana-Cornelia Vese, Roberto Di Stefano, Mircea M. Radulescu

ELECTRONIC CONTROLLED CAPACITOR FOR SINGLE PHASE INDUCTION MOTOR
Radu Campeanu, Constantin Suciu, Aurel Campeanu

THE MODEL OF PERMANENT MAGNET SYNCHRONOUS MACHINES
Eleonora Darie

THE DYNAMIC CONTROL OF A SWITCHED RELUCTANCE DRIVE USING FUZZY LOGIC
Eleonora Darie, Garibald Popescu

VOLT-HERTZ CONTROL OF THE SYNCHRONOUS MOTOR WITH RAMP EXCITING VOLTAGE
Csaba Szabo, Maria Imecs, Ioan Iov Incze

MAGNETIC FIELD IN THE AIRGAP OF THE THREE-PHASE SYNCHRONOUS GENERATOR CONNECTED ON RECTIFIERS Corneliu Nica, Monica Adela Enache

NUMERICAL SIMULATION OF A PRESSURE WAVE INTERACTING WITH A PROTECTION FILTER DURING AN INTERNAL ARC FAULT IN A MEDIUM VOLTAGE CELL David Rochette, Stephane Clain, Francois Gentils, Pascal Andre, William Bussiere

RADIATIVE HEAT TRANSFER IN AXISYMMETRIC SYSTEMS OF NON-ISOTHERMAL SURFACES
Bogdan M. Diaconu, Cristinel Racoceanu

STUDY OF POLLUTANTS DISPERSION RESULTING FROM LIGNITE COMBUSTION IN POWER GENERATION Cristinel Racoceanu, Bogdan M. Diaconu

INTELLIGENT FAULTS INTERRUPTION Florin Munteanu

PROTECTION OF OVERHEAD LINES WITH METAL-OXIDE ARRESTERS Mircea Gusa, Marcel Istrate

SIMULATION SUR ORDINATEUR DES LIGNES DE MOYENNE TENSION DE LA REGION EST DE LA SOCIETE SEEG Paul Makanga, Auguste Ndtoungou, Serge Moctar, Igor Sabatin

NEW APPROACH IN THE SYSTEMS AND ELECTRICAL EQUIPMENT MONITORING AND DIAGNOSTIC Adrian Baraboi, Maricel Adam, Catalin Pancu

A SINGLE-PHASE DUMP LOAD FOR STAND-ALONE GENERATING UNITS WITH INDUCTION GENERATOR Catalin Petrea Ion, Ioan Serban, Corneliu Marinescu

COMPARATIVE ANALYSIS BETWEEN CHP PLANTS AND SEPARATE PRODUCTION
Liviu Ruieneanu

LA MONITORISATION DES DECHARGES PARTIELLES EN CABLES ELECTRIQUES ET ACCESSOIRES : METHODES ET GESTION Mircea-Emilian Ardeleanu

ABOUT MATHCAD MODELING OF BUCK PWM AC REGULATORS Liliana Miron, Mihai Miron, Cristian George Constantinescu

TWO GENERATORS MICRO-GRID BASED ON RES Luminita Barote, Ioan Serban, Catalin Petrea Ion, Corneliu Marinescu, Marius Georgescu

STUDY OF COGENERATION SYSTEMS IN A CHEMICAL INDUSTRY Radu-Cristian Dinu, Ion Mircea

RADIANT ENERGY DENSITY CALCULATION ON A INCLINED SURFACE Cristian Bratu, Felicia Ivan

THE FUNCTION PSS ADDITIONAL SIGNAL INFLUENCE OF THE RAT STRUCTURE FOR A BETTER STATISTICAL AND TRANSITIONAL STABILITY CONCERNING UP-DATING THE IRON GATES HYDRO GENERATORS Sabin Mischie, Ion Mircea, Mihai Mircea

APPLICATION OF PARITY MISCMATHCES IN DETECTION OF BAD DATA FOR POWER SYSTEM STATE ESTIMATION  Leonardo Geo Manescu

DETECTION OF GROSS ERROR BY MODIFIED RELAXATION STATE ESTIMATION IN POWER SYSTEM Leonardo Geo Manescu

ASPECTS CONCERNANT LA LIMITATION DES EFFETS DE LA CIRCULATION DES HARMONIQUES DANS LES RESEAUX DE DISTRIBUTION Silvia-Maria Diga, Denisa Rusinaru, Andrei Cosmin Grigorescu

MODELISATION DU FONCTIONNEMENT EN PARALLELE A DEUX OU PLUSIEURS POMPES CENTRIFUGES IDENTIQUES OU DIFFERENTES Daniela Popescu, Adelaida Duinea, Cristian Bratu

DEVELOPPEMENT D’UN BANC D’EESAIS POUR TESTER DES FUSIBLES AUTOMOBILES
Alina Nicoleta Veliscu

THE VARIATION OF THE UNSIMMETRY FACTORS IN THE LOW VOLTAGE POWER SUPLIES IN SINUSOIDAL REGIME Cornel Toader, Petru Postolache, Nicolae Golovanov, Radu Florin Porumb, Mihai Tisu

THE SIMPLIFIED CALCULUS OF THE FLAT PLATE SOLAR COLLECTOR Andrei Stefan Jercan

DATA ACQUISITION AND CONTROL SOFTWARE FOR THE EDUCATIONAL KIT FESTO (LEVEL AND TEMPERATURE CONTROL) Gabriela Canureci, Camelia Maican, Matei Vinatoru

SAFETY MONITORING SYSTEMS OF DANGEROUS ENVIRONMENTS FOR THE IMPROVEMENT OF WORK SAFETY LEVEL Mihnea Balteanu

THE NUMERICAL SIMULATION OF THE CULTURE MEDIUM FOR THE PLEUROTUS GENUS MUSHROOMS Gheorghe Manolea, Marius Popescu, Cãtãlin Nedelcuþ, Laurentiu Alboteanu

THREE DIMENSIONAL NUMERICAL SOLUTION FOR IMPEDANCE VOLTAGE OF POWER MULTI-WINDING AUTOTRANSFORMER Alin Dolan, Grigore A. Cividjian, Ivan Yatchev, Gheorghe Calin, Dorin Popa

MODELE NUMERIQUE ELECTROTHERMIQUE POUR L’OPTIMISATION DES CONTACTS DEMONTABLES DE FORTS COURANTS Ioan C. Popa, Ioan I. Cautil, Dan Floricau

MODE-S POSITIONAL DATA ERROR ANALYSIS FROM THE POINT OF VIEW OF AIR TRAFFIC CONTROL Stefan Luzica, Petr Svoboda, Pavel Grecman

PROPULSION SYSTEMS FOR MICRO AERIAL VEHICLES Adrian Coman, Mircea Boscoianu, Corneliu Axente

COMPLEX ROTATION SPEED CONTROL SYSTEM FOR TWO SHAFTS JET ENGINES
Alexandru Nicolae Tudosie

DC-LINK CONTROL-LOOP DESIGN OF A SYNCHRONOUS GENERATOR WITH ELECTRONIC LOAD Jenica Ileana Corcau, Pompiliu Constantinache

CONTROL SYSTEM BY AIR BLEED FLAPS FOR SUPERSONIC AIR INTAKES
Alexandru Nicolae Tudosie

AIRCRAFT’S LONGITUDINAL MOTION COMMAND EFFICIENCY CONTROL LAWS
Romulus Lungu

ETUDE SUR LA VITESSE CRITIQUE DE L’ANNULATION DE LA PORTANCE DE L’EMPENNAGE HORIZONTAL DES AERONEFS EN CONFIGURATION CANARD Octavian Preotu

AN ALGORITHM FOR SENSOR DATA FUSION FOR UNMANNED MINI AERIAL VEHICLES
Corneliu Axente, Adrian Coman, Mircea Boscoianu, Nicolae Jula

PARAMETERS ESTIMATION OF THE AIRCRAFT’S LONGITUDINAL AND LATERAL MOVE
Mihai Lungu

ETUDE NUMERIQUE D’UN LIMITEUR DE COURANT DE DEFAUT SUPRACONDUCTEUR INDUCTIF Florian Stefanescu

SUPERCONDUCTIVITY IN MgB Georgeta Alecu, Andreea Cosac, Stefania Zamfir

PHYSICAL MODEL OF SUPERCONDUCTING FAULT CURRENT LIMITER-DESIGN AND TEST
Aristofan Teisanu, Florian Stefãnescu, Ioan Puflea

INDUCTIVE MEASURING DEVICE FOR CRITICAL CURRENT DENSITY Aristofan Teisanu, Georgeta Alecu

TRANSIENT PARAMETERS OF A COIL WITH A SCREENED IRON CORE BY A SUPERCONDUCTOR TUBE Constantin Mantea, Ioan Puflea

THE MICROSTRUCTURE IN THE CRYOGENIC TREATED BEARING STEELS
Vasile Bulancea

EXPERIMENTAL PLANT FOR 18O SEPARATION BY CRYOGENIC OXYGEN DISTILLATION
Floarea Pop, Iuliana Piciorea, Mariana Iliescu, Mihai Culcer, Cornelia Croitoru, Ioan Stefanescu

HELIUM IN MATERIALS USE IN HYDROGEN CRYOGENIC DISTILLATION
Sebastian Brad, Mihai Vijulie, Alin Lazãr, Sorin Gherghinescu