Volumul 27


27-89 EFECTELE VIBRAŢIILOR ASUPRA ORGANISMULUI UMAN

VIBRATION EFFECTS ON HUMAN BODY
This paper contains a study on the vibration effects the human body. Vibrations may cause more or less serious health effects in humans. It shows to entire human body or exposure to hand-arm system and over them the vibrations caused health disorders.
Keywords: vibration effects syndromes, environment
Cuvinte cheie: vibraţii, efecte, sindroame, mediu

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27-88 CONCEPEREA UNEI BAZE DE DATE ALE ZGOMOTULUI EMIS DE UTILAJE ÎN CONSTRUCȚII CIVILE

NOISE MEASUREMENTS ISSUED ÎN CIVILE CONSTRUCTION SITES DATA BASE
This paper contains considerations about the noise issued în construction sites, measuring the effective noise from the devices and equipment used în construction sites. All the data are organize into a data base that, it is, and should be useful în measuring the level of noise that the workers has to deal with în the construction sites. The data base should help the contractors, architects and workers to respect more effectively the noise risk protection rules
Keywords: noise, database, noise limits, database CPT Torino
Cuvinte cheie: zgomot, baza de date, limite ale nivelului de zgomot, banca de date C.P.T. Torino

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27-87 ANALIZA ZGOMOTELOR ŞI VIBRAŢIILOR PRODUSE DE MIJLOACELE DE TRANSPORT

ANALYSIS NOISES AND VIBRATIONS PRODUCED BY TRANSPORT
This article presents the importance analysis of the noises and the vibrations produced by the buses or trucks and the methods that can reduce them.
Keywords: source of noise, traffic, frequency
Cuvinte cheie: sursa de zgomot, trafic rutier, frecvență

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27-86 MENTENANŢA PREDICTIVĂ ÎN STUDIUL MAŞINILOR DINAMICE ROTATIVE

PREDICTIVE MAINTENANCE IN THE STUDY
OF ROTATIVE DINAMICS MASCHINES
The paper contains theoretical substantiation for machines and equipment troubleshooting, machine bodies in rotational motion. It analyses the dynamic rotary machines, fitted with elastic rotor in rigid bearings without damping, as well as the rotor symmetrically rotational movement with the elastic bearings without depreciation.
Keywords : balancing , maintenance, dynamic rotating machines
Cuvinte cheie: echilibrare, mentenanţă, maşini dinamice rotative

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27-85 STUDIUL IMPEDANŢEI MECANICE A MODELULUI CORESPUNZĂTOR SISTEMULUI UMAN MÂNĂ-BRAŢ

STUDY OF MECHANICAL IMPEDANCE OF THE MODEL CORRESPONDING FOR HAND-ARM HUMAN SYSTEM
The present paper will be a presentation of one possible method of driving mechanical impedance determination. Exposure to harmful vibrations can lead to damages of the structures and health problems or disorders that can appear at the human body. The knowledge of the structures and human body mechanical impedance is essential for realizing appropriate administrative, technical and medical prevention measures.
Keywords: mechanical impedance, vibration, human hand-arm system
Cuvinte cheie: impedanţă mecanică, vibraţii, sistemul uman mână-braţ

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27-84 UNELE ABORDĂRI PRIVIND DETERMINAREA VITEZEI DE DEPLASARE A UNEI RACHETE ÎN SPAŢIUL INTERPLANETAR

SOME APPROACHES CONCERNING THE DETERMINATION OF THE VELOCITY OF A ROCKET INTO INTERPLANETARY SPACE
This paper presents a method of calculation for a fundamental parameter of the missile flight dynamics, movement speed in a fluid medium. It is used in this sense of angular momentum theorem and momentum theorem in fluid mechanics.

Keywords: rocket, reaction force, mass forces, trajectory, mass flow, volume control, non-inertial reference system, exhaust nozzle

Cuvinte cheie: rachetă, forţă de reacţie, forţe masice, traiectorie de zbor, debit masic, volum de control, sistem de referinţă neinerţial, ajutaj de evacuare

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27-83 INFLUENŢA EFECTULUI TERMIC ASUPRA FRECVENŢELOR PROPRII ALE GRINZILOR ÎNCASTRATE LA AMBELE CAPETE

THE EFFECT OF THERMAL LOAND ON THE NATURAL FREQUENCIES OF DOUBLE-CLAMPED BEAMS
The natural frequencies of double-clamped beams are influenced by environmental conditions and operational loads. For instance the temperature induces axial loads due to restraint displacements, which lead after a critical temperature increase to buckling. This paper clarifies the effect of external loads on the natural frequencies of beams.
Keywords: thermal loads, buckling, Euler-Bernoulli beam, natural frequency
Cuvinte cheie: încărcări termice, flambaj, grindă, frecvenţe proprii

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27-82 INFLUENŢA FENOMENELOR DE ECRUISARE ŞI ÎMBĂTRÂNIRE ASUPRA MODULULUI DE ELASTICITATE

THE INFLUENCE OF COLD-HARDENING AND AGING
ON THE COEFFICIENT OF ELASTICITY
Existing industrial steel structures, and especially those we use in the steel industry, for whom the normal operation age is approaching completion, are affected by the phenomena of cold-hardening and aging of steel. Depending on the size tension (unit stress) and the period of running, this paper is intended to adopt a different coefficient of longitudinal elasticity corresponding to components of the resistance structure.
Keywords: hardening, artificial aging, elastic modulus, strength, tension (unit effort)
Cuvinte cheie: ecruisare, îmbătrânire artificială, modul de elasticitate, rezistenţă mecanică, tensiune (efort unitar)

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27-81 CONCLUZII ŞI CONTRIBUŢII PERSONALE LA CONFIRMAREA REZULTATELOR NUMERICE PRIN ANALIZA REZULTATELOR OBŢINUTE EXPERIMENTAL, PENTRU VAGONUL DESCOPERIT CU PEREŢI ÎNALŢI

CONCLUSIONS AND PERSONAL CONTRIBUTIONS
TO THE CONFIRMATION NUMBER OF RESULTS
BY ANALYZING EXPERIMENTAL RESULTS,
WAGON DISCOVER HIGH WALLS
This article aims to confirm the results obtained using the finite element method to simulate the compression on a freight wagon buffers discovered by high walls Comparing the numerical results with experimental results obtained with the method of resistive electric tensometry.
Keywords: cargo wagon, finite elements, stresses, deformations
Cuvinte cheie: vagon de marfă, elemente finite, tensiuni, deformaţii

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27-80 ÎNCERCAREA DE COMPRESIUNE A BILELOR DE RULMENT

THE COMPRESION TEST OF THE BEARING BALLS
The compression test of the bearing balls is not included in the category of classic methods this is regulated by normative like (STAS or ISO). They appear as a necessity where developed and manufactured various kinds of bearings. In this perspective the paper presents the concept of a specialized device for applying a compressive force to the bearing balls of different sizes, and some half-ball.
This makes it possible experimental research of the state of stress and strain that occurs in ball bearing in compression during operation using various methods like: electric resistive strain and/or photo elasticity (fotostress).
Keywords: ball bearing, compression, specialized device
Cuvinte cheie: bilă, rulment, compresiune, dispozitiv specializat

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27-79 CONSIDERAŢII PRIVIND ÎMBUNĂTĂŢIREA TIPULUI DE ÎNCERCARE AL ADEZIVILOR

CONSIDERATIONS ON THE ADHESIVE TESTING
TYPE’S IMPROVEMENT
The authors of the contribution analyse several types of the specimens, involved in the adhesives’ testing protocol. Based on the results of the Finite Element analysis, respectively of the experimental investigations ones, by means of Holographic Interferometry, they suggest a new type of specimen, which assures a more accurate evaluation of the pure shear effect in the adhesive layer. Also, their original testing stand destined to Holographic Interferometry investigations, described in an earlier contribution, can be efficiently involved in this new type of investigation of the adhesives.
The most critical issue consists of the high-accuracy determining of the shear strength of the adhesive layer, without the bending’s additional effect.
The proposed methodology and type of the specimen offer the adequate answer. The author’s further goal consists in involving this new approach in different kind of adhesives’ examination.
Keywords: Adhesive, shear resistance, Holographic Interferometry, specimen, testing stand
Cuvinte cheie: adeziv, rezistenţa la forfecare, Interferometria Holografică, epruvetă, stand pentru teste

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27-77 ANALIZA EXPERIMENTALĂ A UNOR PARAPETE DE PROTECŢIE CE ECHIPEAZĂ CĂILE RUTIERE, CA MODELE FUNCŢIONALE Partea a II-a

EXPERIMENTAL ANALYSIS OF SOME
PROTECTION PARAPETS EQUIPPING ROADS,
AS A FUNCTIONAL MODEL – PART II
The objective of this paper is to present the analysis of constructive solutions for protective barriers shock devices that use elastic elements, more efficient than normal operations designed to handle and mitigate some of the energy developed when the shock. These are in the form of concentrated damping systems mounted clamping area of the parapet of the tower.
Keywords: protective parapets, shock absorbers devices, concentrated dampers, elastic elements
Cuvinte cheie: parapete de protecţie, dispozitive amortizoare, amortizoare concentrate, elemente elastice

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27-76 ANALIZA EXPERIMENTALĂ A UNOR PARAPETE DE PROTECŢIE CE ECHIPEAZĂ CĂILE RUTIERE, CA MODELE FUNCŢIONALE Partea I-a

EXPERIMENTAL ANALYSIS OF SOME
PROTECTION PARAPETS EQUIPPING ROADS,
AS A FUNCTIONAL MODEL – PART I
The objective of this paper is to present the analysis of constructive solutions for protective barriers shock devices that use elastic elements, more efficient than normal operations designed to handle and mitigate some of the energy developed when the shock. These are in the form of concentrated damping systems mounted clamping area of the parapet of the tower.
Keywords: protective parapets, shock absorbers devices, concentrated dampers, elastic elements
Cuvinte cheie: parapete de protecţie, dispozitive amortizoare, amortizoare concentrate, elemente elastice

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27-75 STUDIUL DURABILITĂŢII CONDUCTELOR PE BAZA CONCEPTELOR MECANICII RUPERII

THE STUDY OF DURABILITY PIPES BASED ON FRACTURE
MECHANICS CONCEPTS
The paper describes the lifetime analysis of steam pipes subjected to
internal pressure by applying the concepts of Fracture Mechanics of materials.
It also presents the durability analysis of a pipeline with semi-elliptical
longitudinal crack subjected to internal pressure.
Keywords: pipe internal pressure, crack, durability, ego
Cuvinte cheie: conductă, presiune interioară, fisură, durabilitate,exemplu

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27-74 APRECIEREA COMPORTĂRII CONDUCTELOR FISURATE PRIN CRITERIILE MECANICII RUPERII

ASSESSMENT OF CRACKED PIPES BEHAVIOR BY FRACTURE MECHANICS CRITERIA
The paper presents the methods used to assess the behaviour of cracked pipes subjected to internal pressure by applying the Linear Elastic Fracture Mechanics criteria (LEFM). It is also described an analysis of a cracked steam pipe used in Romanian power plants.
Keywords: fracture mechanics, pipe, fracture toughness, heat resistant steel
Cuvinte cheie: mecanica ruperii, conducte, tenacitate la rupere, oţel termorezistent

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27-73 ANALIZĂ CUPLATĂ, FLUENT FLOW – STATIC STRUCTURAL

COUPLED ANALYSIS, FLUENT FLOW – STATIC STRUCTURAL
This paper represents the beginning of research work for two students. It summarizes the steps to achieve a coupled analysis using ANSYS software and also presents the results obtained as a result of the laminar flow of a fluid through a bend 900 polyethylene. This paper represents a beginning of research from two students.
Keywords: coupled analysis, ANSYS, fluid, deformations

Cuvinte cheie: analiză cuplată, ANSYS, fluid, deformații

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27-72 ANALIZA COMPUTAŢIONALĂ A TENSIUNILOR MECANICE ÎNTR-O PIESĂ TURNATĂ DIN ALIAJ PE BAZĂ DE ALUMINIU

COMPUTATION ANALYSIS OF MECHANICAL STRESS
IN A ALUMINUM ALLOY CASTINGS
This paper presents a theoretical mechanism for the formation of mechanical stresses in aluminium alloy castings EN AC-Al Si7Mg0,3 and the computational analysis of residual mechanical stresses in case of cylindrical parts, moulded from a mixture of green sand and of cast iron.
We present a comparison of the values mechanical residual stresses obtained by free and braked shrinkage for this alloy casting.
Keywords: mechanical stress, contraction, aluminium alloy, castings, solidification
Cuvinte cheie: stres mecanic, contracție, aliaj de aluminiu, piese turnate, solidificare

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27-71 CONSIDERAȚII ȘI CALCULE ASUPRA CAZANELOR LOCOMOTIVELOR CU ABUR Partea a II-a

CONSIDERATIONS AND CALCULATIONS ON BOILERS OF STEAM LOCOMOTIVES. PART II

Part II of the paper presents a brief history of rail transport, exposure of the first steam locomotive that circulated in our country and characteristics. In Part II of the paper presents a study and proposals for repair of the boiler of the locomotive. It analyzes the phenomena occurring inside the boiler during operation. The purpose of repairing steam locomotives is to be played recreational circuits in different geographical areas.

Keywords: steam locomotive, boiler, rail, recreation

Cuvinte cheie: locomotivă cu abur, cazan, transport feroviar, agrement

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27-70 CONSIDERAȚII ȘI CALCULE ASUPRA CAZANELOR LOCOMOTIVELOR CU ABUR Partea I-a

CONSIDERATIONS AND CALCULATIONS ON BOILERS OF STEAM LOCOMOTIVES PART I

Part I of the paper presents a brief history of rail transport, exposure of the first steam locomotive that circulated in our country and characteristics. In Part II of the paper presents a study and proposals for repair of the boiler of the locomotive. It analyzes the phenomena occurring inside the boiler during operation. The purpose of repairing steam locomotives is to be played recreational circuits in different geographical areas. Keywords: steam locomotive, boiler, rail, recreation Cuvinte cheie: locomotivă cu abur, cazan, transport feroviar, agrement

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27-69 DETERMINAREA DEFORMAŢIILOR LA O STRUCTURĂ ÎN ARC DE CERC

DETERMINATION OF DEFORMATION
TO A STRUCTURE IN AN CIRCULAR ARC
The paper presents the analysis of displacement to a structure in an circular arc. Displacements of free ends of the structure were analysed in dependence of the position of the anchorage.
Keywords: displacements, deformations, tare
Cuvinte cheie: deplasări, deformaţii, greutate proprie

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27-68 CALCULUL DIAGRAMELOR DE EFORTURI PENTRU GRINZILE DREPTE UTILIZÂND PROGRAMUL MATHCAD

THE COMPUTATION OF SHEAR DIAGRAMS, IN ACTION WITHIN STRAIGHT BEAMS, USING MATHCAD
The paper presents the program CRDEF-GGA-06 created by the author which calculates the reactions axial forces, bending moment respectively shear diagrams for straight static determinate beams.
The program CRDEF-GGA-06 is an application of MathCAD software.
Keywords: reactive, efforts, efforts diagrams
Cuvinte cheie: reacţiuni, eforturi, diagrame de eforturi

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27-67 STUDIUL COMPORTĂRII SUB SARCINĂ STATICĂ ȘI DINAMICĂ A GRINZII PRINCIPALE (profil I) A MACARALEI PORTAL (MACARA CAPRĂ) PARTEA II – STAREA DE DEFORMAȚIE A GRINZII PRINCIPALE ÎN MODUL DE LUCRU ”ANIMAȚIE”

THE STUDY OF THE BEHAVIOR UNDER STATIC AND DINAMIC LOAD OF THE MAIN BEAM (PROFILE „I”) OF A PORTAL CRANE (GANTRY CRANE)
PART II – THE STATE OF DEFORMATION OF THE MAIN BEAM IN THE „ANIMATION” WORKING MANNER
The lifting of the load at a certain height, its stop with a waiting of a 5 s, the descent of the load with a delay of 5 s, the descent of the load with its halt and waiting of approximately 5 s, leads to a certain load of the structure of the portal crane. Therefore one establishes that in the structure of the main beam appear compelled oscillations. In the frequency spectrum of the induced oscillatory motion, the main weight is that of the oscillation whose frequency is equal to the force in the driving cable; one establishes that the Eigen frequencies of the whole structure – the portal crane as a whole, are excited, too. Hence, the approach performed by the authors in the following study: a favourable working of the crane means that the Eigen frequencies of the structure as a whole must be outside the frequency field of the excitation forces, main beam: the state of stress and deformation under static and dynamic load.
Keywords: portal crane, force, structure, animation, frequency
Cuvinte cheie: macara portal, forță, structură, animație, analiză în frecvență

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27-66 STUDIUL COMPORTĂRII SUB SARCINĂ STATICĂ ȘI DINAMICĂ A GRINZII PRINCIPALE (profil I) A MACARALEI PORTAL (MACARA CAPRĂ) PARTEA I – STAREA DE DEFORMAȚIE A GRINZII PRINCIPALE SUB SARCINĂ APLICATĂ STATIC

THE STUDY OF THE BEHAVIOR UNDER STATIC AND DINAMIC LOAD OF THE MAIN BEAM (PROFILE „I”) OF A PORTAL CRANE (GANTRY CRANE)
PART I – THE STATE OF DEFORMATION OF THE MAIN BEAM UNDER STATIC LOAD
Because of the specific nature of the cranes’ activities, these ones have to accomplish a lot of norms concerning the security and labour protection. At the working beginning but also recurrently, the cranes are subjected to a test set in order to check the technical state with a view to the authorization. The verifications are performed by specializes departments and involve the following steps: ▪ the check of the main elements; ▪ tests of loads; ▪ tests under static and dynamic load; ▪ other tests which have in view the whole behavior of the crane.
With a view to the authorization all the tests are compulsory but the present paper presents the analysis of the main beam under the action of external loads. In the current activity one established that the imposed check in order to authorize the cranes are necessary but not enough to ensure those working safety. The present paper makes an important analysis of the main beam: the state of stress and deformation under static and dynamic load.
Keywords: portal crane, force, deflection, acquisition system, transducers
Cuvinte cheie: macara portal, forță, săgeată, sistem de achiziție, traductoare

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27-63 LEONARDO DA VINCI (15.04.1452 – 02.05.1519) INGINERUL ARTIST – GENIU UNIVERSAL Partea I-a

LEONARD DE VINCI (15.04.1452-02.05.1519). L’INGENIEUR ARTISTE – GENIE UNIVERSEL – PART I
L’article présente, d’une manière synthétique, les principales étapes de la vie et de l’activité du génial Léonard de Vinci. Son apprentissage dans l’atelier de Florence du maître Verrocchio a prouvé sa fécondité, car c’est là qu’il a appris les bases de la chimie, de la métallurgie, de la mécanique, ainsi que les techniques artistiques de dessin, de peinture et de sculpture en marbre ou en bronze. Son talent exceptionnel, le travail assidu, sa maîtrise dans de multiples domaines ainsi que la passion de savoir et d’expérimenter l’ont conduit à la réalisation d’œuvres admirables: «l’Annonciation», «L`Adoration des mages», « La Vierge aux rochers », « La Cène », «La Vierge, L`Enfant Jésus avec sainte Anne et saint Jean Baptiste », « La Vierge, L`Enfant Jésus et sainte Anne », « La Joconde », « La bataille d’Anghiari » etc. Tout aussi doué pour les arts que pour la recherche scientifique, l’ingénierie, toutefois passionné par l’étude des phénomènes naturels, expérimentateur, autodidacte, Léonard fait preuve d’une couverture encyclopédique de ses curiosités: anatomie, médicine, géologie, mathématiques, mécanique, résistance des matériaux, astronomie, hydraulique, architecture et fortifications, aviation, machines de guerre, étude des animaux et des plantes, etc. Léonard de Vinci incarne parfaitement l’esprit de la Renaissance à l’époque des «grandes découvertes» – le plus grand génie universel de tous les temps, curieux de tout, vouant toute sa vie à la recherche, au savoir, à l’art, et… à combattre le mal!
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Mots-clés: art, la peinture, „sfumato”, architecture ingénierie, mécanique, résistance des matériaux, de l’anatomie, la médecine, l’eau, l’astronomie, la géologie Cuvinte cheie : artă, pictură, «sfumato», arhitectură, inginerie, mecanică, rezistenţa materialelor, anatomie, medicină, hidraulică, astronomie, geologie

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27-62 CLAUDE NAVIER – 230 DE ANI DE LA NAŞTERE

CLAUDE NAVIER – 230 YEARS SINCE HIS BIRTH
In this paper are presented aspects from the technical, didactical and scientifically activity of the most representative personality of the domain of Strength of Materials which even today constitutes a beacon in the development of this engineering domain. Navier has extremely important contributions to the substantiation of the Theory of Elasticity and the development of the Strength of Materials. By theoretical and practical research Navier established the basis for the calculations for resistance and rigidity of straight or curved bars, statically determinate or statically indeterminate. For plane plates Navier established the differential equation of the median deformed and studied behaviour for vibrations.
Keywords: neutral axis, suspension bridge, strength of materials, tension
Cuvinte cheie: axa neutră, pod suspendat, rezistența materialelor, tensiune

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27-61 CONSIDERAŢII PRIVIND STUDIUL PARAMETRILOR GAZODINAMICI LA DEPLASAREA CORPURILOR CU VITEZE SUPERSONCE ÎN PREZENŢA UNDEI DE ŞOC DETAŞATE

CONSIDERATIONS IN MOVING BODIES GAS DYNAMICS PARAMETERS STUDY WITH PRESENCE IN GEAR SUPERSONCE DETACHED SHOCK WAVE
This paper presents a method to study the parameters of flight in the atmosphere, the bodies’ neaerodinamics at supersonic speeds in the presence of detached shock wave.
Keywords: body neaerodinamic, shockwave, entropy wave resistance, kinetic energy, dash attack, Mach number
Cuvinte cheie: corp neaerodinamic, undă de şoc, entropie, rezistenţă de undă, energie cinetică, bord de atac, numărul Mach

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27-60 CONSIDERAŢII PRIVIND UTILIZAREA EFECTULUI CUMULATIV AL JETURILOR DE GAZE LA PERFORAREA BLINDAJELOR

CONSIDERATIONS FOR USE CUMULATIVE EFFECT
OF GAS STREAMS PUNCTURE ARMOR
This paper presents an application of the linear characteristics of the fumes generated by the chemical reaction of burning of explosives, the cumulative effect. By directing the energy of the explosion we obtain a jet of gas able to penetrate machines fight casings.
Keywords: jet gas, explosive, cumulative jet, armour, fighting machine, surge, movement potential
Cuvinte cheie: jet de gaze, exploziv, jet cumulativ, blindaj, maşină de luptă, undă de şoc, mişcare potenţială

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27-59 PROBLEME ALE SISTEMULUI DE RĂCIRE A ETANŞĂRILOR POMPELOR PRIMARE DE TRANSPORT AL CĂLDURII LA CNE CERNAVODĂ

CNE CERNAVODA PRIMARY HEAT TRANSPORT PUMPS GLAND SEAL COOLING SYSTEM PROBLEMS
Primary Heat Transport Gland Seal Cooling System scope is to provide a high pressure D2O cooling flow to the primary heat transport pumps seals. The system safety function is to maintain PHT pressure boundary integrity and to prevent radioactivity releases.
Keywords: pumps, gland seal, problems, CNE Cernavodă
Cuvinte cheie: pompe, etanşări, CNE Cernavodă, probleme

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27-58 MODELE PENTRU CALCULUL VIITURII MAXIME PROBABILE (VMP) ŞI ANALIZA DISTRIBUŢIEI ÎN TIMP Partea a II-a

MODELS FOR MAXIMUM PROBABLE FLOW CALCULATION AND THE TIME DISTRIBUTION ANALYSE – PART II
This paper presents an approach to estimate the maximum flow calculation and the time distribution analyse for different rivers from Romania.
Keywords: maximum probable flow calculation, time distribution, maximum probable rain
Cuvinte cheie: Viitura maximă probabilă, distribuție în timp, precipitația maximă probabilă

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27-57 MODELE PENTRU CALCULUL VIITURII MAXIME PROBABILE (VMP) ŞI ANALIZA DISTRIBUŢIEI ÎN TIMP Partea I-a

MODELS FOR MAXIMUM PROBABLE FLOW CALCULATION AND THE TIME DISTRIBUTION ANALYSE – PART I
This paper presents an approach to estimate the maximum flow calculation and the time distribution analyse for different rivers from Romania.
Keywords: maximum probable flow calculation, time distribution, maximum probable rain
Cuvinte cheie: Viitura maximă probabilă, distribuție în timp, precipitația maximă probabilă

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27-56 CAPACITATEA DE ÎNCĂRCARE A UNEI CENTRALE HIDROELECTRICE ÎN FUNCŢIE DE NIVELUL ÎN LACUL AVAL

THE LOAD CAPACITY OF A HYDROELECTRIC
POWER PLANT BY THE LAKE TO DOWNSTREAM
In the paper presents the results of measurements of the tailrace of the hydroelectric power Șugag underground HPP (high head cents) to determine the maximum power that can be achieved with the safe operation of the plant by Şugag HPP capacity transport manifold run it. The paper presents how to perform monitoring and protection system for monitoring water levels in tailrace.
Keywords: hydroelectric power plant, hydraulic turbine, efficiency, run gallery
Cuvinte cheie: centrală hidroelectrică, turbină hidraulică, randament, galerie de fugă

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27-55 DETERMINAREA SOLICITĂRILOR PRIZELOR DE APĂ CU CONDUCTE ÎNGLOBATE ÎN PILE

THE STRESS DETERMINATION FOR WATER
INTAKES WITH PIPES INSIDE PILES
This paper presents the initial stress calculations performed in order to validate a future innovative solution which incorporates both the sluices and the water intake with the supply pipes embedded within the concrete piles.
A brief calculus was done to estimate the supplementary forces involved in the dam stress. It starts from simplifying assumptions in order to estimate the stress supported by the concrete piles. The obtained results will be furthermore used to determine if the envisaged solution requires special methods of foundation or structural reinforcement.
Keywords: water intakes, supply pipes, dam cells, dams
Cuvinte cheie: prize de apă, conducte de alimentare, pile, baraje

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27-54 UTILIZAREA METODELOR NUMERICE PENTRU ESTIMAREA COEFICIENTULUI DE CONTRACȚIE AL UNUI ORIFICIU

THE USE OF NUMERICAL METHODS FOR ESTIMATING
THE CONTRACTION COEFFICIENT OF AN ORIFICE
This paper presents one of the numerical methods that integrate the Navier-Stokes equations, namely the method of finite differences, in order to determine the flowing through a tank and the contracted section of the liquid passing through an orifice.
Keywords: flow coefficient, current lines, orifice, numerical methods
Cuvinte cheie: coeficient de debit, linii de curent, orificiu, metode numerice

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27-53 CONSIDERAŢII TEORETICE PRIVIND CALCULUL DE REZISTENŢĂ ŞI AL DEFORMAŢIILOR CAMERELOR ROTOARELOR TURBINELOR AXIALE ORIZONTALE (BULB)

THEORETICAL ASPECTS REGARDING THE STRENGTH CALCULATION AND THE DEFORMATIONS OF THE HORIZONTAL TURBINE RUNNER CHAMBERS
This paper presents main theoretical considerations regarding the strength calculation and the deformations of the horizontal axial turbine runner chambers – upstream bulb. The most suitable functional and constructive solutions – for those bulb turbines which designed at Hydro-Engineering, the runner chamber has the lower half embedded in the concrete, and the upper half of this is fixed through a bolted threaded connection and threaded studs. The strength calculation of the deformations is made only for the upper half of the runner chamber.
The establishment of the fundamental equations regarding the strength and deformation calculations have been made taking into account the theory of the plane and curved plates of S. Timoshenko. For solving the equations and avoiding the in determinations it has been used the energetic method (Castigliano’s method). Considering the stressing types that are applied to the upper half of the runner chamber in the paper, it is shown the forces and moments that is stressing the threaded connection of the upper half in relation to the lower half which embedded in the concrete
Keywords: turbine, runner, deformation, bulb
Cuvinte cheie: turbină, rotor, deformaţie, bulb

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27-52 CONSIDERAŢII PRIVIND CONCEPŢIA MODELULUI DE VANĂ FLUTURE DESTINAT EFECTUĂRII CERCETĂRILOR EXPERIMENTALE

CONSIDERATIONS REGARDING THE BUTTERFLY VALVE MODEL DESIGN TO PERFORM THE EXPERIMENTAL RESEARCH
The paper presents a model of butterfly valve designed to perform experimental research in the laboratory to determine the functional parameters of industrial (prototype) butterfly valve. The model is designed considering the Froude similarity criterion based on the geometric dimensions and the design of the prototype valve having a nominal diameter of 4.9 m and operates at a pressure of 17.1 bar. The paper presents adaptations designed model can be mounted on the test bench for hydraulic turbines and experimental research can be obtained putting in optimal conditions.
Keywords: Butterfly valve model, testing stand, experimental research, similitude criterion
Cuvinte cheie: model de vană fluture, ştand se încercări, cercetări experimentale, criterii de similitudine

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27-51 CONSIDERAŢII PRIVIND CERCETĂRILE EXPERIMENTALE REALIZATE PE UN MODEL DE VANĂ FLUTURE

CONSIDERATIONS REGARDING THE EXPERIMENTAL RESEARCH PERFORM BY AN BUTTERFLY VALVE MODEL
The paper presents experimental research performed on a model of butterfly valve in the test stand of the testing laboratory to determine the functional parameters of a prototype butterfly valves ND 4900 mm who operating at a pressure NP17 bar. The valve model is designed and executed based on design and the size butterfly valve prototype applying Froude similarity criterion. It is presented the test stand and the experimental research results obtained regarding to determining the hydraulic resistance coefficient and consequently the flow coefficient and the determination of forces and moment coefficients, the coefficient of cavitation and vibration level.
Keywords: Experimental research, butterfly valve model, testing stand, coefficients
Cuvinte cheie: cercetări experimentale, model de vană fluture, stand de încercări, coeficienţi

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27-50 OPTIMIZAREA FORMEI DISCULUI VANEI FLUTURE CU COEFICIENT DE REZISTENȚĂ HIDRAULICĂ DE 0,07

BUTTERFLY VALVE DISC SHAPE OPTIMISATION FOR HYDRAULIC RESISTANCE COEFFICIENT 0.07
The paper presents the optimization of butterfly valve disc shape to obtain hydraulic resistance coefficient 0.07 by numerical methods and by experimental measurements realized in Hydro-Engineering Co. Reşiţa. It is presented the test stand, the optimized butterfly valve disc model which measurements were made and the results of model tests. The results of model tests conducted by similarity criterion for butterfly valve with nominal diameter 4900 mm and nominal pressure of 170 mwc consists of determining the hydraulic resistance coefficient and consequently the flow coefficient and the determination of forces and moment coefficients, the coefficient of cavitation and vibration level.
Keywords: disc butterfly valve, hydraulic resistance coefficient, numerical analysis
Cuvinte cheie: disc vană fluture, coeficient de rezistență hidraulică, analiză numerică

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27-49 MĂSURĂTORI DE VIBRAŢII DE JOASĂ FRECVENŢĂ LA TURBINE FRANCIS

LOW FREQUENCY VIBRATION MEASUREMENTS
ON FRANCIS TURBINES
This paper presents an analysis on vibration measurements performed on Francis turbines. Absolute vibration measurements on draft cone tube and proximate measurements on shaft were presented with respect to low frequency phenomena.
Keywords: absolute vibration, kurtosis analysis, relative vibration, draft cone tube
Cuvinte cheie: vibraţii absolute, vibraţii relative, con aspirator, analiza kurtosis

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27-48 ANALIZA EFECTULUI ROTIRII ÎN JURUL UNEI AXE A PALETELOR ROTORICE ALE TURBINELOR RAPIDE DE TIP FRANCIS ÎN VEDEREA MĂRIRII PERFORMANŢELOR ENERGO-CAVITAŢIONALE ALE ACESTORA

STUDY OF THE EFFECT OF THE FAST FRANCIS TURBINE BLADES’ SPIN AROUND AN AXIS, FOLLOWING CFD ANALYSIS OF FLOW AND RESULTS OF MEASUREMENTS IN THE LAB
The present paper propose an analysis of the rotation around an axis effect of the runner blades that compound the fast Francis turbines in order to increase their energo-cavitational performances. First step was done after the analysis of the runner which resulted from the calculations and hydro-dynamic design. This analysis was performed both theoretically using the finite element software package called CFX Blade Gen, and through experiment within the Test Laboratory for Hydraulic Turbines from Hydro-Engineering. Second step of the research consisted in rotating the blade around the axis with a certain angle in order to increase the absorbed flow, holding the rim and the ring from the initial blade. Rotating was performed in different angles by making the finite element analysis for all the rotating angles. In order to improve the cavitational component it was proposed and realized an extension of the blade with an appropriate covering degree, without any visible effect over the energetic features, these being maintained within the permitted error range that admitted by the IEC 60193 code.
Keywords: blade, runner, Francis
Cuvinte cheie: paleta, rotor, Francis

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27-47 ASPECTE PRIVIND EROZIUNEA CAVITAȚIONALĂ LA CONURILE ASPIRATOARE DE LA TURBINELE FRANCIS

ASPECTS OF CAVITATION EROSION AT SUCTION
CONES FROM FRANCIS TURBINES
In this article is presented the effect of cavitation applied to the suction cones that equip Francis turbines of HPP Motru. Cavitation erosion is evaluated through in-situ measurements are processed and presented in a new way in this article. It was determined a correlation between various regimes of functioning and the cavitation erosion appeared on the suction cones. Also experimentally was determined optimal maintenance period considering the cavitation attack intensity.
Keywords: cavitation, vacuum con, turbine, Francis, coefficients of cavitation, aeration
Cuvinte cheie: cavitație, con aspirator, turbină, Francis, coeficienți de cavitație, aerare

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27-46 DIMENSIONAREA TURBINELOR AXIALE

THE DIMENSIONING OF THE AXIAL TURBINES
In this paper is presented a new method for calculating the axial
hydraulic turbines, whose applicability is demonstrated by a numerical
example. This method is based on the torque developed by the turbine
rotor, which from reasons of simplicity, has been obtained by the 
theorem of dimensional analysis. Calculation results with the proposed
method for the flow of small water falls are in a good accordance with
those in the specialty literature. The method should be extended and
verified for large and medium flow and water falling.
Keywords: turbine, rotor, method, calculation, water, hydraulic,
axial
Cuvinte cheie: turbină, rotor, metodă, calcul, apă, hidraulic, axial

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27-45 SISTEME DE MONITORIZARE ÎN CONDIŢII DE RISC A CENTRALELOR HIDROELECTRICE CU ACUMULARE PRIN POMPARE (CHEAP)

MONITORING SYSTEMS IN HAZARDOUS CONDITIONS OF HYDROELECTRIC PUMPED STORAGE (CHEAP)
The primary purpose of modern automation purposes of modern automatic control systems of hydroelectric plants are:
– Automatic adjustment of speed (frequency) and/or power energy group known as Automatic speed control systems (SRAV)
– Automatic adjustment of the voltage generator known as automatic control systems excitation (SRAE)
– Adjust the water level in the reservoir and swirled flow, depending on the spatial requirements
– Protection hydropower group to failures, defects or on the electric or hydraulic side.
Keywords: automatic control systems, automatic adjustment of speed, generator voltage
Cuvinte cheie: sistemelor de conducere automată, reglarea automată a turaţiei, tensiunii generatorului

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27-44 INTERPRETAREA TENSIUNII INTERFACIALE LA ULEIURILE MINERALE ELECTROIZOLANTE FOLOSITE PENTRU TRANSPORTUL CURENTULUI DE ÎNALTĂ TENSIUNE

INTERPRETATION OF INTERFACIAL TENSION ON
MINERAL OILS USED AS CARRIERS OF ELECTRICAL CURRENT OF HIGH VOLTAGE
The interfacial tension against water is a polar soluble contaminants detection and degradation products . This feature is changing fast enough oil to trade vessels iniţial.Determinarea stage is commonly applied oils filled with insulating oil equipment in operation.
Keywords: interfacial tension, temperature, auto-transformers, oil analysis, hidroscopicitate electrical equipment
Cuvinte cheie: tensiune interfacială, temperatură, analize de ulei, autotransformatoare, hidroscopicitate, echipamente electrice

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27-43 STUDIUL EXPERIMENTAL AL COMPORTAMENTULUI DIELECTRIC AL DIGLICIDIL ETER DE BISFENOL ”A” ÎNCĂRCAT

EXPERIMENTAL STUDY OF THE DIELECTRIC
BEHAVIOR OF DIGLYCIDYL ETHER
OF BISPHENOL ”A” CHARGED
Subject reinforced composite materials are extensively investigated in recent years. This study is deepened to improve the structural and dielectric characteristics of diglycidyl ether of bisphenol A (DEGBE). Dielectric properties were analysed for each batch of material. Microcompozite epoxy samples with good dispersion of nano – particles laden epoxy matrix was prepared and experienced for the dielectric constant (C) , resistance (R ) and impedance (Z) frequency (1kHz, 10kHz) . Measurements were made using a dielectric spectoscropia plateau temperature range of between 20-80 °C . The better dielectric properties of the material corresponding to the nano – fillers in a concentration of 30 % .
Keywords: DGEBA, pozzolan, dielectric constants, microstructure
Cuvinte cheie: DGEBA, rocă vulcanică, constanta dielectrică, microstructură

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27-42 O PRIVIRE MATEMATICĂ ASUPRA PIERDERILOR PE LINIA DE TRANSPORT ÎN REGIM DEFORMANT

A MATHEMATICAL APPROACH TO THE LOSSES OF TRANSMISSION LINE UNDER NON-SINUSOIDAL REGIME
In this paper we present a mathematical proof of additional losses in the electrical energy transmission line due to superior harmonics. The proof is based on the Cauchy – Buniakovski – Schwarz inequality, a very important inequality in mathematics. Was considered a simplified model, but the obtained result generalizes to complex electrical circuits. At the beginning of the paper there was a more general overwiev of the issue of technological losses in power transmission line. Finally, we draw the conclusions and we indicate the references.
Keywords: electricity transmission line, transmission line losses, deforming operating system, mathematical proof of additional losses under deforming
Cuvinte cheie: linie de transport a energiei electrice, pierderi pe linia de transport, regim deformant de funcţionare, demonstraţie matematică a pierderilor suplimentare în regim deformant

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27-41 MODELAREA FIZICĂ A EFECTULUI CORONA LA TENSIUNE ALTERNATIVĂ

CORONA PHISICAL MODEL IN ALTENATIVE VOLTAGE
Corona discharge around power lines leads to line parameter alternation as an electric charge is formed around the wires. In transient states, such alternations result in faster damping of oscillations while in steady regime lead to additional energy losses. The paper treats the physical Corona modelling and the analytical transients process of voltages and currents on the proposed model.
Keywords: model, Corona, electronic scheme
Cuvinte cheie: model, efect Corona, schemă electronică

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27-40 CALCULUL PIERDERILOR DE PUTERE DATORATE EFECTULUI CORONA

CASLCULUS OF ELECTRIC POWER LOSSES
DUE TO CORONA EFFECT
The paper present the properly designed for Corona model required to produce reasonably close modelling of electric power losses on very high electric lines. Corona modelling has been approached by means of analogue physical or mathematical modelling is treated herewith.
Keywords: power losses, method, Corona, power lines
Cuvinte cheie: pierderi de putere, metodă, efect Corona, linii electrice

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27-39 STUDIUL BIOSISTEMULUI PEȘTI ELECTRICI (P.E.)

STUDY BIOSYSTEMS ELECTRIC FISH (P.E.)
Understanding the phenomena that are specific electrical biosystems, the existence of specialized cells for detecting, measuring and storing electricity, which enable these phenomena. Finding sources of electricity inspired by natural model, but other research direction as the electric discharge and electrical insulation. With the technical model, visualizing electrical discharges of different voltages and currents, check some assumptions-assumptions to an embodiment of the primary data.
Keywords: autologous, non-autologous electrical, impulse nerve, corticalii centers, electric shock, synapses, dendrites, electrical nerve
Cuvinte cheie: autolog16, non-autolog electric, impuls nervos, centri corticali, șoc electric, sinapse17, dendrite, nervi electrici

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