Scientific Bulletin Series C, Volume XIX (2005)
REDUCING THE ENVIRONMENTAL IMPACT OF MINING IN THE CONTEXT OF SUSTAINABLE DEVELOPMENT
Livia ADAM, Eng. Corneliu POPESCU, Eng. Mihail Nicolae RUDEANU, Economist,. Adriana BOCIAT, Eng
Abstract: The paper, a synthesis of a larger analysis performed in the past years, deals with the problems of identifying the factors affecting environment related to mining activity an d proposals to reducing the negative effects. In this respect, the main characteristics of the Romanian mining industry are analyzed, and the impact assessment on main environmental factors is evaluated. On this basis, the key measures to be performed, in the idea of sustainable development are presented.
INTELLIGENT END-EFFECTORS FOR ASSEMBLY ROBOTS
Ferenc ALPEK, Ferenc SZEKELY
Abstract: Manufacturing automation helps to increase the qu ality and reliability of products with reduced costs. The Intelligent Manufacturing Systems (IMSs) using robots can realise the advanced automated production. The most important and complicated operation of the robotized production is the assembly. During automated assembly a lot of end-effect ors (grippers, tools and special devices) have to be used to make the “final version” of the product. The end –effectors are built into the last robot wrist. During automation the human involvement has to be replaced with sensory systems and advanced control systems realising the monitoring and adaptive control of processes. Intelligent end-effectors (grippers, micro-grippers, tools and gripper and tool changers) are the very important components of the assembly robots.
To replace partly the human intelligence with machine intelligence using intelligent end-effectors is the goal of this development work.
The present paper gives a brief overview about recent developments in these fields, primarily focused on the gripper applications.
Keywords: Robot grippers, micro-grippers, sensory systems, intelligent peripheries, end-effector’s changers
THE RATIONAL PARAMETERS OF THE TOP CAVING LONGWALL FACES IN THE CONDITIONS OF JIU VALLEY – ROMANIA COALFIELD
Iosif ANDRAS, Nicolae ILIAS, Sorin RADU, Ph.D., Mihael MELCZER
Abstract: The top caving mining method is a high productivity technology being more and more widely used worldwide. In order to implement this method in Jiu Valley coalfield, the rational parameters of faces were determined, such as: the mining height, the hanging block height, the shifting between two adjacent slices, as a function of the different categories of mining conditions (seam thickness and slope, mining depth, physical-mechanical properties of surrounding rocks and coal, the mining method etc.). The paper deals with these calculation using deterministic and FEM modeling.
Keywords: coal mining, top coal caving, mining methods
MATHEMATICAL MODELING OF WASTE WATER CLEANING PROCESS IN SEDIMENTATION TANKS
Iosif Andras, Valeria Victoria Iovanov, Miodrag Iovanov, Angela Draghici
Abstract: A model of the concentrations of suspended solids (SS) in the aeration tanks and in the effluent from these during sedimentation operation is established. The model is based on simple SS mass balances, a model of the sludge settling and a simple model of how the SS concentration in the effluent from the aeration tanks depends on the actual concentrations in the tanks and the sludge blanket depth.
The model is formulated in continuous time by means of stochastic differential equations with discrete-time observations. The parameters of the model are estimated using a maximum likelihood method from data from an alternating wastewater treatment plant.
The model is an important tool for analyzing ATS operation and fo r selecting the appropriate control actions during ATS, as the model can be used to predict the SS amounts in the aeration tanks as well as in the effluent from the aeration tanks.
Keywords: Aeration Tank Settling, mass balance, grey-box models, statistical identification, on-line measurements
SELF-REGULATING TWO D-O-F CONNECTED PLANETARY GEAR DRIVES HAVING CONSTANT TRANSMISSION RATIO
Dr. Ferenc, Levente Czégé
Abstract: The study below deals with the two degree-of-freedom connected drives having constant transmission ratio. These connected systems consist of two differential gear drives and two one degree-of-freedom gear drives. We define the necessary kinematic- and inner ratios, than we determine the possible powerflows of the connected system. The study shows expressively the evolution of the inner motion state which meets the moment- and power equlibrium conditions. In this state the connected planetary gear drive works with optimal efficiency.
Keywords: differential gear drive, connected drive, self regulation, two degree-of-freedom system
A comparison of a tensile test with a planar simple shear test in sheet metals
Abstract: The tensile test is commonly considered as the standard test in sheet metals, although the mechanism of plastic deformation during tension is very complicated. The planar simple shear test is more suitable to determining mechanical properties of these materials. In the article, the characteristics obtained in the tensile test are compared with the same obtained in the simple shear test. The investigations were performed on ETP-cooper, CuZn37 brass and low-carbon steel sheets.
Keywords: plasticity criteria, simple shear test, tensile test
COMPUTER AIDED EQUITHERMICAL ADJUSTMENT IN THERMAL MANAGEMENT
Petr BARON, Peter BRÁZDA
Abstract: The paper describes the possibilities of communication adjustment system with superior layer, represented by software package created by PAUFEX Co. for adjusting of regulator using ekvithermical regulation by scanning temperature of water in central heating and outdoor temperature with servo-unit controlling converter vent.
Keywords: Ekvitermical regulation, outdoor temperature, Servo-unit controlling converter vent
CONSIDERATIONS CONCERNING THE MANUFACTURING THE SPIROID HOB WITH REVERSE TAPERED
Vasile BOLOŞ, Codruţa BOLOŞ, Bogdan BUCUR
Abstract: The paper presents the manufacturing particularities of the milling worm used in the processing of the spiroid hob with reversed tapered. It is taken as an example the real case of the archimedical type worm milling tool used in the construction of spiroid wheels with axial module ma=2,5 mm, Z2=47 and axial distance A=56.
Keywords: Hob, Hobing, Spiroid
AUGMENTED VIRTUAL REALITY APPLICATIONS IN MANUFACTURING
Peter Brázda, Jozef Novák-Marcinčin
Abstract: Augmented Reality (AR) is a growing area in vi rtual reality research. The world environment around us provides a wealth of information t hat is difficult to duplicate in a comput er. This is evidenced by the worlds used in virtual environments. Either these worlds are very simplistic such as the environments created for immersive entertainment and games, or th e system that can create a more realistic environment has a million dollar price tag such as flight simula tors. An augmented reality system generates a composite view for the user.
It is a combination of the real scene viewed by the user and a virtual scene generated by the computer that augments the scene with additional information.
Keywords: virtual reality, augmented reality, virtual technologies
CAD ASPECTS OF THE DESIGN PROCESS OF A COUPLING WITH FRICTION SHOES AND ADJUSTABLE CENTRIFUGAL DRIVING
Adrian BUDALĂ, Aurel JULA
Abstract: The paper presents few stages of the design process of a coupling with friction shoes and adjustable centrifugal driving. There are also presented some advantages of the using of CAD software.
Keywords: Coupling, adjustable centrifugal driving, CAD
OPTIMAL SIZE OF A LOGISTIC TERMINAL
Burciu Ştefan, Ştefănică Cristina
Abstract: Regression models have often been used to determine the size of logistic terminals within urban areas. Although these models may be good for calculating the required size of logistic terminals of a company because they can easily represent the relationship between the required facility size of a logistic terminal and the amount of goods handled within it, they can’t represent the o verall impact on urban logistics systems, especially on traffic conditions on the road network. Berths are established for trucks to load and unload goods within logistic terminals and therefore relate more strongly to the tr affic conditions outside logistic terminals than other facilities. The size of other facilities within logistic terminals is also considered, with construction and management costs being incorporated into berth costs.
Optimization of the number of berth must take into account the characteristics of truck arrivals at berth and loading/unloading service ability provided by them so that the impact of constructing logistic terminals on society at large can be considered. This can be represented by queuing theory using a trade-off between transportation costs and facility costs within a logistic terminal.
Keywords: logistic terminal, berths, network, queuing theory, distribution
INTELLIGENT SYSTEM OF GEARBOXES DESIGN
Eugen Valentin BUTILĂ, Gheorghe Leonte MOGAN
Abstract: In this paper it is proposed an Intelligent Integrated System of gearboxes design as independent products. The CAD activities in correlation with expert system regulations are defined according to a given expertise domain (design of mechanical systems) that supposes taken into account and operating with two information categorie: knowledge and data. Knowledge processing as an expert rule base generally works with qualitative information that involves searching for suitable solutions and their combination into conception variants. Data processing is based on computational models and suppose inter-related with reasoning knowledge process. In order to generate an expert – CAD/CAE/CAM system of gearboxes design in this work it is presented an overall algorithm that integrate knowledge processing activities with solid modeling, analysis of behaviors and manufacture aspects.
Keywords: Expert systems, Computer aided design, Gearboxes design, Total design, Finit element analysis
THE PRECISION INDEXES ANALYSIS OF TOOTHED GEARS MANUFACTURED BY PLASTIC DEFORMATION
Abstract: The paper studies the dimensional and form precision, the surfaces roughness aspects in toothed gears manufacturing through different plastic deformation proceedings. It analyses the tools wear and its influence of manufactured toothed gears precision indexes.
STUDY ON THE MECHANICAL PROPERTIES OF THE ROCK SALT
Drd. Ing. Cavai Mirela
Abstract: A problem of high importance and great complexity in the extractive industry is the cutting operation of rocks, especially the cutting of rock salt. The acquired experience acknowledges that in present and also in the near future the technology used in the excavation of rock salt is and it will be a mechanized one.
Keywords: rock salt, hardness, strength, friability
DESIGN METHOD OF ELASTIC COUPLING WITH CYLINDRICAL BOLTS AND NONMETALLIC ELEMENTS FROM RUBBER
Marilena Radu, Emil Chişu
Abstract: In this paper is present design method for new elastic couplings with cylindrical bolts and nonmetallic intermediary elements, which are realized from various rubber qualities. The novelty of this couplings types consist in existence of one disc between those two semi couplings (the disc is not presents centering thresholds), of eight metallic plates and the nonmetallic elements from rubber are mounting on the bolts.
Keywords: elastic coupling, torsion moment, bolts, design method, new constructive forms from various rubber qualities
RESEARCH ON REDUCING ENERGY CONSUMPTION IN THE TECHNOLOGICAL PROCESS OF GLASS MANUFACTURING
M. Crivanasu, T. Rusan, N. Ilias, S. Radu, I. Andras
Abstract: The present tendencies in glass industry are reduction of energy consumption in glass manufacturing, considering that the highest expenses are the energy used to reach the high temperatures in the furnace. The paper presents the research on the furnace work conditi on, with direct glass melting flow in SC STAR GLASS SA Tg. Jiu.
Keywords: glass, energy, furnace, thermal condition, temperature gradient
IMPLEMENTING TRIBOTECHNICAL DIAGNOSTICS IN AUTOMOTIVE INDUSTRY
Ivan Čorný, Hekmat Al Hakim
Abstract: The contribution deals with an influence of up-to-date lubricants in agricultural power tractors on tractors longevity. Importance of periodical tribotechnical diagnostics measurements as a mean of rapid wear-out prevention in various heavy machinery is considered.
Keywords: tribology, tribotechnical diagnostics, maintenance, lubricant, automotive industry
CONTRIBUTIONS REGARDING THE DESIGN OF A GEOMETRICAL STRUCTURE AT A SPECIAL FLUIDIC DEVICE
Adriana COTEŢIU, Radu COTEŢIU
Abstract: This paper presents the theoretical researches regarding the geometrical structure analysis at the wall – attachment device. The examined monostable element is a special device with an incompressible fluid as supply jet and compressible fluid as command jet. The obtained results were used to realize a model of this type of special fluid device tested experimentally.
Keywords: monostable fluidic element, supply jet, command jet, attachment distance, wall angle
THE INFLUENCE OF THE SURFACE FINISHED STATE ON THE POLIAMIDIC ROLLING FRICTION COUPLES
Radu COTEŢIU, Adriana COTEŢIU, Vasile NĂSUI
Abstract: The friction destructive processes generate on the friction couples have been developed the preoccupation of a great number of scientists which studies the important effects in technical, technological, economic and social level. A friction couple which was correct lubricate may have a long life of functioning. So, for this reason, the present paper presents some researches about surface finished state on the friction couples.
Keywords: friction, friction surfaces, rolling friction coefficient
VALORIZATION OF THE WORLD MINERALOGICAL HERITAGE MAIN OBJECTIVE OF THE WORLD MINERALOGICAL ORGANIZATION
Abstract: A large amount of mineralogical samples are used for different purposes, from simple collection hobby, to scientific research and teaching material, exhibition objects and museistic objects. Beyond these activities, the involved samples represent a part of humanity’s inheritance. The valorization, conservation, promotion and sustainable management of this inheritance represent the objectives of the recently founded WMO. The paper deals with the objectives and activities planned to be performed by WMO in this field.
Keywords: mineralogy, cultural heritage, mineral samples, virtual museum
INFLUENCE OF FUEL CHARACTERISTICS ON ATMOSPHERE POLLUTION AT ROVINARI POWER PLANT
Luminiţa Mihaela Crăciun, Emilia Moisescu
Abstract: The combustion of Rovinari lignite generates large amounts of pollutants, such as ash, carbon dioxide, sulfur dioxide and nitrogen oxides. The emission of pollutants in the atmosphere depends on the composition of fuel, installation of fuel preparation, combustion installation, effectiveness of ash retaining system and effectiveness of burning system. The paper analyses how each of the above factors contribute to the atmosphere pollution.
ABOUT THE DISTRIBUTION OF RELAXATION TIMES IN DIELECTRICS
Rodica CREŢ, Laura CREŢ
Abstract: When studying non – homogenous dielectrics, the distribution of relaxation times is crucial in order to appreciate their behavior in the frequency domain. First, this paper presents an overview of the functions of distribution of relaxation times. Then, a computation method is emphasized, and these functions are graphically represented using MathCAD worksheet. The frequency variation graphics of the two components of the complex permittivity are also outlined, when the influence of the electric conductivity is considered or not.
Keywords: dielectrics, dielectric relaxation, complex permittivity, Cole – Cole diagrams, MathCAD worksheet
TOOLS AND APPLICATIONS OF COMPUTER AIDED MANUFACTURING AND ROBOT VIRTUAL MODEL DESIGNING
Nadežda Čuboňová, Darina Kumičáková
Abstract: This article describes the possibilities of CAD/CAM/CAE system tools utilisation in the area of the engineering applications. One part of the article contains the problem of the Computer-Aided Manufacturing. The specific examples of CAD/CAM system Pro/ENGINEER applications in solving of the engineering practice tasks are presented. The possibilities of the utilisation of computer aid in the industrial robot and manipulator virtual model designing is contained in the next part of the article. The attention is aimed on the application of CAE module of system Pro/ENGINEER especially.
Keywords: computer aid, CAD/CAM/CAE system, numerical control, robot, manipulator
AIRCREAFT CONTROL LAWS MODIFICATION AS A CONSEQUENCE OF FAILURES APPEARANCE
Abstract: Failures of aircraft control and navigation systems are critical, because their presence can
dramatically decrease flight safety. To make the flight safe, the failures, which can occur in its subsystems, must be considered during designing process. This paper presents the architecture of control system which makes possible to achieve its highest safety. Changing the way of using their subsystems, redesigning its own structure and updating its parameters to adapt to the new situa tion can be named as reconfiguration. The necessary information for reconfiguration process is generated by the fault detection and isolation systems. Good cooperation of these systems makes aircraft control and navigation systems fault-tolerant. These problems which respect the conference motto: “Unity in diversity” will also be presented.
Keywords: Fault Tolerant Control, Reconfiguration, Fly-By-Wire Control System Architecture
RESULTS OF IRRADIATION IN THE MINING ACTIVITY, POSSIBLE RISK SOURCES
Drăghici Angelica – Nicoleta
Abstract: In this paper is studied the problem of radiation exposing in mining industry (especially in the coal mines). The radiation sources from the mine’s atmosphere, where the radon is disintegrated appearing its solid disintegration products, named also descending products, presents a risk degree both for the personnel trained directly in work and for the personnel not exposed professional, and for the rest of the population. The radiation exposing should be known by each miner, in every work zone of the mine and the time spent by the miners in every work zone.
RESIDUAL WATER EVACUATION SYSTEM FUNCTIONING WITH PRESSURE WAVES
Abstract: The paper presents a new evacuation system for the residual waters and a theoretical approach regarding the functioning of the hydraulic systems, which are working with pressure waves. There are presented the design and the main characteristics of the alternative flow and pressures generator and also of the cannular pump. The final part of the paper presents the equations, which defines the water-evacuated flow in the ideal case of functioning.
Keywords: residual waters, alternative generator, cannular pum, pressure waves
ABRASIVE WEAR OF ENGINEERING POLYMER GEARS
Eberst Ottó, Pop Sever, Dr. Kalácska Gábor, Keresztes Róbert, Zsidai László, Dr. DeBaets Patrick
Abstract: The paper introduces first some commonly used engineering polymers from the practical life and selected for the further investigation. Regarding the different ranking of polymer/steel pairs from the point of friction and wear obtained by many different tribometers and test-system, it would be difficult to choose the best polymer/steel pair to make a polymer gear. Based on the survey of the semi-fini shed engineering polymer distributors and producers we selected the top five engineering polymers used for gears on the European market to investigate the wear with real elements. The second part gives a summary about the wear testing of polymer spur gears mating with steel gears under abrasive condition. At the end of the paper the evaluation of the measured results and a short conclusion can be found.
Keywords: engineering polymers, spur gears, abrasive wear
EFFECTS OF ABRASIVE WATERJET PROCESS PARAMETERS TO MICROGEOMETRICAL QUALITY OF STAINLESS STEEL AISI 304
STANISLAV FABIÁN, SERGEJ HLOCH
Abstract: The paper presents the experimental work of evaluation of process parameters of abrasive waterjet cutting. Full factorial design 24 was used as a statistical method to study effects of independent variable factors – pressure, J/T abbreviations, abrasive mass flow and traverse rate to impact to dependent variable roughness average R a which is measured in three depths of samples. The data have been analyzed using ANOVA, in order to identify the variables that significantly affect the relationship between the taper and factors. The regression equations obtained from ANOVA gives the level quality Ra.
Keywords: abrasive waterjet, full factorial design, process parameters, surface quality
SOME FEATURES OF BULLYING AT SCHOOL
Abstract: A number of different sources indicate that agression, terro r, hatred, voiolence and
hostilities become more and more powerful in all areas of human life. Individual people and
various organizations all over the world raise their voices in order to put an end to this
phenomenon. The entire human society appears to have a direct or indirect opinion about the
issue. The increasingly impatient search for a solution is permeated by a sense of fear, distrust
and even impotence, leading to a general d ecline of optimism among individual people and
THE ROLE OF SUBSIDIES IN ECONOMY AND ITS INFLUNCE CONCERNING THE ECONOMIC OPERATORS
Assist. Prof. Fleser Alina , Ec. Capotescu Ionel, Ec. Ungur Valer, Ec. Negrila Cosmin Paul
Abstract: The paper deals with the highlights of the influence and role of subsidies in economiy. The analysis is focused on the influence in economic health of state owned companies receiving subsidies and the social effects generated, mainly in mining industry. Some recommendations in the cautiouness in using this financial lever situate at the crossing point of economics and politics are formulated.
Keywords: subsidies, state budget, incomes, expenses
THE RELIABILITY INDICATORS FOR MINING HYDRAULIC AGGREGATES
Florea Alexandru, Florea Carmen, Dinescu Stela
Abstract: The paper present the research results regarding the reliability of the hydraulic aggregate used in mining exploitations from Jiu Valley area. The Pareto diagrams and reliability indicators have been determined using experimental data.
Keywords: reliability indicators, Pareto diagrams, packing plunger, high pressure pump
GRASSLAND FARMING AND ENVIRONMENT PROTECTION IN EASTERN HUNGARY
Abstract: The environment protection has greater importance in the grassland farming, according to other agricultural sector. The National Agri-environment Porteciton Program (NAPP) and the National Rural Development Program (NRDP) was formed in harmony with the European Agricultural Model, which support the sustainable development and the environment friendly technologies. The subsidized area’s about 6 per cent and the supported aplications’s about 9 per cent proportion from the national volume shoxs the majority of the extensive grassland farming in the county of Szabolcs-Szatmár-Bereg. One of the NRDP’s most supported target ares are the grasslands, which Program use EU financial sources. The direct useing of the higher subsidies hopefully would serve the problems of our grassland farming and animal breeding and the rural population’s living.
Keywords: environment protection, extensive grassland farming, importance, rural development
SPECIAL ASPECTS IN TRIANGULATION AND MAPPED MESHING
Florin FRUNZULICĂ, Irina Carmen ANDREI
Abstract: The purpose of this paper is to focus on special aspects with regard to the triangulation and mapped meshing. A presentation of the concepts and basic theory is offered, which was intended as an adequate answer for the questions like what, how and why.
Keywords: mesh generation, triangulation, Octree, Delaunay, point insertion, boundary constraint triangulation
THE EFFECT OF NUTRIENT SUPPLY ON THE YIELD AND QUALITY OF MAIZE HYBRIDS
Zoltán Futó, Péter Jakab
Abstract: The experiment is a random block settling artificial fer tilisation test carried out on small plots. During the experiment we applied seven different fertilizer bacteria treatments (Micro soil), which we supplemented with a control plot.
We have stated shat the grain moisture content was the highest during the control treatment. The reason probably is that under control conditions the nutrient supply of maize is not optimal.
The control plots had the lowest average yield, but these were between 6,25 and 7,6 t/ha, too. We can claim that improving the nutrient supply the crop results were higher. Without the bacteria treatment the crop results were between 7,8 and 9,5 t/ha. The most favourable results occurred in case of 40-80 kg/ha N treatment.
Under the influence of soil bacteria treatments in many cases the average yields were better, which obviously proves the nutriment transformation ability of the bacteria. With bacteria treatments the result was 9,7 – 11,3 t/ha, so owing to this we registered 0,5 – 1 t/ha extra yield.
Keywords: maize, bacteria fertilizer, mineral fertilizer, yield, protein content
A NEW VIEW ON TECHNOLOGIES BASED ON NATURAL RESOURSES COMPLEMENTARY TO TECHNOLOGIES BASED ON INFORMATICS’ AND INFORMATIONAL RESOURSES
Ionuţ I. GÂF / DEAC
Abstract: A country or a region’s natural resources is a quantitative and qualitative accumulation,
with a specific type of dispersion, a sine-qua-non condition for the concretization of local or zonal development projects. These could become “motivations” or “premises” for operational decisions.
In this context, natural resources may have a “role”, a “function” and an instrumental objective character (“means”) to initiate and support development.
DESGIN STRUCTURE BASED TASKS SCHEDULING USING GENETIC ALGORITHMS
István Gromma, Tamás Rick
Abstract: This paper deals with a modeling and optimization method that is capable of the product structure based optimization of design processes. The processes were modeled with Design Structure Matrix. Since the precedence task is a whole NP one, guided stochastic search techniques were applied. The impact of the probability of mutation and crossover and the two different selection processes on searching was examined.
Keywords: product development process, genetic algorithm (GA), design structure matrix (DSM), learning rate
METHODS AND EQUIPMENT FOR THE EXTRACTION OF JIU VALLEY COAL SEAMS WITH SHORTWALL FACES
Iosif Gruneantu, Ph.D., Prof.; Livia Ilias Ghitoiu, Eng. Ph.D. Trainee;. Corneliu Popescu, Eng. Ph.D. Trainee
Abstract: Starting from the analysis of the existing technologies and equipment to mine out the coal seams using shortwall faces, of the specific geologic-mining conditions, existing in the Jiu Valley coalfield, a series of equipment and related technologies are presented which can improve the performances of coal mining in these conditions.
TWO-STAGE GEAR WITH AN INNER MOVING WHEEL
Jozef Haľko, Ján Paško
Abstract: This paper describes a two-stage gear with several output shafts having different gear ratios and torque. The paper describes also their power drive possibilities.
Keywords: reducer, two-stage speed, different outputs, power drive
KINETICS OF HEAVY METAL EXTRACTION FROM POLLUTED SOILS USING EDTA
Ágnes Hargitai Tóth, József Balogh
Abstract: The kinetics of Cd, Pb and Cr extraction with EDTA (ethylene-diamine-tetraacetic acid) from artificially polluted chernozem and humous alluvial soils was investigated. The efficiency of the extraction was for Cd more than 95%, for Pb more than 80% (chernozem soil) and more than 95% (humous alluvial soil). In both cases, the extraction reached equilibrium state. For Cd and Pb the metal-ion removal processes, in the first 30 minutes of extraction, can be modelled by two simultaneous, pseudo-first order, irreversible reactions. One of the reactions is fast and can be attributed to complex formation reactions between EDTA and metal ions occurring on the surface of inorganic minerals and humus-compounds and to the dissolution of the water-insoluble precipitates.
The less part of the metal ions took part in a rather slow reaction, where EDTA complexed heavy metal ions bound in the internal lattice sites. The slow dissolution of the metal compounds should also be considered.
The slow extraction partly can be attributed to slow irreversible processes (e.g. diffusion from the internal lattice sites).
In the case of Cr(III), the extraction was found to be a very slow process, the efficiency of removal was less than 3%. The system did not atta in the equilibrium state. Probably the rates of extraction processes are intermediate between those of the slow and fast reactions.
Keywords: complexation, complexing agent, kinetics, extraction
THE PRINCIPLE OF PLASMA CUTTING TECHNOLOGY AND SIX FOLD PLASMA CUTTING
Abstract: Plasma cutting is very interesting and progressive technology. By cutting thermical and dynamic effects of the plasma’s beam are utilize. The cut is smooth and accurate. This article presents formation of the accounts of plasma and practical its employment in industrial process and it presents new technology in plasma cutting.
Keywords: plasma, plasma jet, plasma arc, plasma beam
ABRASIVE WATERJET PROCESS FACTORS INFLUENCE ON STAINLESS STEEL AISI 304 MACROGEOMETRICAL CUTTING QUALITY
Sergej Hloch, Stanislav Fabian
Abstract: This study deals with abrasive waterjet process parameters influence to taper. Evaluation has been carried according to design of experiments. Full factorial design has been used as a statistical method to study effects of selected process parameters. The pressure, abrasive mass flow rate, traverses rate and J/T abbreviation as independent variable, has been evaluated their significance and their impact to the taper as a dependent variable. Obtained regression equations after analysis of variance give the level quality as a function of the process parameters. It has been found that pressure, and traverse rate are important with the depth.
Keywords: Abrasive waterjet, quality, design of experiments, process parameters
SOLUTION THERMODYNAMICS AN COPPER-OXYGEN SYSTEM
V. Hotea, Gh. Iepure
Abstract: This work presents the study of some thermodynamic properties of the Cu-O system, which represent the base of several technological processes in the pyrometalurgy of copper. The research have been determined several thermodynamic measurements activity and activity coefficient of oxygen in liquid copper-oxygen function on the temperature and oxygen concentration influence on them. The experimental results have been compared to various thermodynamic models reference to metallurgical melting for alloys and discovery of some structural information on the melting in the studied system.
Keywords: copper, activity, activity coefficient, atomic ratio, oxygen, interaction coefficient
THEORY AND THERMAL ANALYSIS OF HIGH EFFICIENCY DEEP GRINDING PROCESS
Michal Hrala, Dr. Andre Batako, Dr. Michael Morgan
Abstract: Particular emphasis of the paper is given to the application of achieved research findings in high efficiency deep grinding process (HEDG) and thermal modelling. A new thermal model based on the inclined heat source developed for the HEDG process is reviewed. The effect of grinding contact length on temperature is also discussed and advanced calculation of contact length is applied in the thermal model.
Keywords: High efficiency deep grinding, thermal model, contact length, temperature
INCREASING PERFORMANCES OF EXPLOITATION TECHNOLOGIES USING DATA FROM A GEO-INFORMATIONAL MODEL
Livia Ghiţoiu Iliaş
Abstract: The paper present a geo-informational model with data of a relevant degree of
usefulness in mine monitor performances of exploitation technologies. This model could be
generated in each mine and the data offered by it have a signific ant influence on the
behaviour of machines, machinery and equipment in the extraction process.
RESEARCHES RELATED TO THE CONSTRUCTIVE IMPROVEMENT OF TEETH USED ON WORKING PARTS OF EXCAVATING-LOADING EQUIPMENT FOR SOILS AND ROCKS
lias Nicolae, Radu Sorin, Smarandoiu Gheorghe, Toropu Pompilia,
Abstract: On the basis of a detailed analysis of the different shapes of teeth used on working parts of the excavating-loading equipment for soils and rocks, new shapes of such teeth were conceived and designed. The paper deals with the results of laboratory testing of the ware of these teeth, and the economic assessment of the efficiency of short and long term use of these teeth.
MATHEMATICAL MODELING OF THE POWERED ROOF SUPPORT/SURROUNDING ROCK INTERACTION
Nicolae Ilias, Alin Simota, Mihael Melczer, Andrei Andras
Abstract: The behaviour of powered roof support in different geological conditions is simulated using a dynamic model taking into account the roof convergence, the support-surrounding rock contact and the shield’s stiffness. In such a way, the selection of the appropriate support according to the mining-geological is easier to be performed.
Keywords: roof support, mathematical modeling, coal mining
THE ECONOMIC RESTRUCTURING OF MONOINDUSTRIAL REGIONS AS A PREMISE OF SUSTAINABLE DEVELOPMENT
Anelia Luiza Ispas, Gabriela Gheorghe
Abstract: Nowadays Romania is preparing to enter into the European Union. In this respect the large enterprises must be adapted to the restructuring, modernization and making profitably. The paper present the Romanian industrial system structure, the future role of large enterprises in accordance with their privatization and restructuring. : Monoindustrial regions from Eastern and central Europe, being in transition towards market economy, represent the target of restructuring policies. The consequences of desindustrialization, make the process of transition more painful as at national level. These regions possess non utilized resources but are characterized by the lack of alternatives , due to their former status. In order to insure a sustainable development of these regions, and overcome the inherite d strengths and weaknesses it is necessary to combine regional development policies with natio nwide development strategies. A few aspects of these topics are treated in the paper.
Keywords: management, restructuring, environment, monoindustrial regions
THEORETICAL AND EXPERIMENTAL STUDIES OF THE SPINDLE OF A HIGH SPEED TURNING MACHINE
Ispas Constantin, Zapciu Miron, Mohora Cristina, Anania Florea Dorel
Abstract: The paper presents a new methodology for research and optimization, from point of view of a dynamical behaviour, of high speed main spindle of a turning machine tool with 6000 rpm. The theoretical studies were made by using Finite Element Method (FEM) in the advanced CAD/CAE software CATIA V5R7 and the results were validated by experimental FFT spectra and transfer function measures using Vibroport 41 – Bruel&Kjaer.
Keywords: High Speed Spindle, High Speed Machining, Finite Elements Method, dynamic behaviour. FFT and transfer functions analysis
ASPECTS CONCERNING THE STRESS AND DISPLACEMENTS FROM THE STRUCTURE OF THE METALLIC TOWERS OF THE EXTRACTING INSTALLATIONS WITH TWO WHEELS DURING AN EXTRACTING CYCLE
Abstract: In the paper there are presented aspects concerning the state of stress and displacements from the structure of the metallic tower of an extracting installation given the loads which are transmitted through the bearings of the deviating pulleys from the tower during an extracting cycle. The extracting installation is unbalanced with extracti ng vessels untipping elevators and the extracting machine with two wheels and operating asynchronously.
Keywords: Strains, displacements, metallic tower, extracting installation
THE IMPACT OF NUTRIENT SUPPLY ON THE YIELD OF WINTER WHEAT VARIETAS
Péter Jakab, Zoltán Futó
Abstract: We examined the effect of nutrient supply on the yield of five winter wheat types in Mezőtúr in 2004. The soil of the experiment was calcareous meadow chernozem soil. We applied eight treatments: controll (non fertilized), controll+bacterium fertilizer, N 40+PK, N 40+PK+bacterium fertilizer, N 80+PK, N 80+PK+bacterium fertilizer, N 120+PK, N 120+PK+bacterium fertilizer. In the droughty year of 2003 the plants were able to utilise only a part of the nutrient in the soil. In the first part of 2004, due to the convenient quantity and spread of precipitation the plants took up th e nutriment not only for 2004 but also the remained quantity from 2003.
It resulted in that according to our examination the early and midterm types reached their best yield on lower nutriment level (Ø+B , N 80+PK). 2004 should be re garded as an exceptional year so we paid attention to these conditions when evaluating. Factual conclusion can be drawn only after the results of several years, we wish to continue our examinations.
Keywords: winter wheat, fertilizer, bacterium fertilizer, yield
THE PLASTIC DEFORMATION OF STAINLESS STEELS BY DRILLING
Abstract: The workpiece material affect the machinability as does the cutting edge, tool holding, machine tool, operation and machining conditions. Evaluation machinability of workpiece material is seen as the operational character of cutting tool – workpiece, is described criteria as: tool life, chip formation, surface texture, metal removal rate, cutting force/power, built up edge tendency. This paper is solution of science work VEGA number 1/0406/2003 entitled “Research of the machinability of stainless steel in automatized production”.
Keywords: cutting tool, plastic deformation, drilling, stainless steels
MATHEMATICAL MODELLING OF ARCH FORMATION IN GRANULAR MATERIALS
Abstract: The mathematical modelling of formation, stability and damage of se lf-supporting stagnant arch like structures inside bulk material discussed in this paper. Some experimental methods will also be presented, for the measurement of material properties used in the mathematical model. We present an algorithm for the determination of critical outlet size for a simplified model silo.
Keywords: granular material, arching, finite element method, triaxial apparatus
EXPERIMENTAL DRYING OF TOBACCO LEAVES
Benedek Kerekes, Tamás Antal
Abstract: The purpose of the investigation was to determine the moisture relationship experimentally in the drying of tobacco leaves. A simple experimental model was applied for calculating the moisture ratio. The measurements carried out in a ‘climate box’, studying different tobacco leaves. Two measuring cycles were carried out during the latest research work. In the first the tobacco leaves were hung up in their natural condition, but in the second trial the midrib was removed from the tobacco leaves. As we expected, the dehydration of the mutilated tobacco leaf – with the midrib removed – was much quicker than drying of the ‘whole’ leaf. The dehydration of the midrib itself was considerably slower than that of the lamina. An important result was that the Walton exponential function was found to be suitable for describing dehumidification. The final conclusion is that the drying coefficient increased greatly when the drying temperature was raised.
DISASSEMBLING OPERATION CREATION CONCEPT IN CAPP SYSTEM SYSKLASS
Ing. Marek KOČIŠKO, PHD., Ing. Peter BRÁZDA
Abstract: The paper deals with the implementation of joints disassembling technology into the CAPP system Sysklass. It describes the ways of technological documentation creation in this system.
Keywords: Disassembly, Sysklass, Construct documentation
THE FUNCTION OF THE FRUIT–GROWING AND –PROCESSING IN THE COUNTY OF SZABOLCS-SZATMÁR-BEREG
Abstract: Hungary has great agro-ecological suitabilities for the fruit-growing and the fruits has prominent function in the nutrition. The fuits are eated raw or as protected products in the whole year. In the county of Szabolcs-Szatmár-Bereg the fruit-growing has prominent function, because Hungary’s mare than 60% of fruit production comes from the county. The apple takes the first place, which followed by the stone-fruits. Novadays the main aim of the fruit growing to decrease the friut fluctuation and to improve the quality, in front of increasing the yields.
Keywords: fruit-growing, fruit-processing, fruit yields, market
COMPARING THE FRICTION PROPERTIES OF POLYMER SLIDING BEARINGS
Mihály KOZMA, Ferenc FORÁNYI, László MÁTÉ
Abstract: The Institute of Machine Design at the Budapest University of Technology and Economics has been investigating the tribological properties of polymers for decades. Recently polyamides, polyamide composites and “high performance polymers“ have been investigated. There was found extremely high coefficients of friction in some cases by tests using polymer block – steel cylinder pairs. It seems line contacts are disadvantageous in the point of view of friction of polymers.
Polymer sliding bearings paired with steel shafts resu lt better friction properties. During these tests pure polyamides and polyamides containing lubricants and also other polymers as polyacetal homo- and copolymers, polyethylene-terephtalat were investigated. The aims of the investigations were to determine the maximal load carrying capacity of polymer bearings in dry and lubricated conditions. These results are summarized in this article.
Keywords: Polymer, sliding bearing, tribology, friction, maximum load carrying capacity
THE SENSING SYSTEM BY ELECTRIC STRAIN PAGES
Abstract: This paper describes the development of a new concept of cutting tools using strain gages for the measurement of forces in turning operations. The basic idea is the integration of the sensor within the tool shank, in order to obtain a system which is easy to use, easy to install and capable of transmitting data to the CNC through wireless equipment. In particular, the output signal of the measurement bridge is amplified and sent to an external data acquisition system by infra-red transmission.
Keywords: Tool Condition Monitoring, Turning, Cutting Force Measurement
THE BRIEF VIEW ON ARTIFICIAL INTELIGENCE TOOLS AS INSTRUMENT OF EFECTIVITY IMPROVEMENT OF PROCESS PLANNING IN CHIPLESS TECHNOLOGIES
Ing. Jozef KUBA, PhD. , Prof. Dr. Ing. Ivan KURIC
Abstract: The paper presents brief view of complex effective of technological product preparation with aspect to non-machining technologies. It is relatively complicated problem close-knit with cost structure in design phase of process and real production phase too. The article describes possibilities of application of particular tools of artificial intelligence in design stage on the ground of forging and casting process specifics.
Keywords: technological product preparation, artificial intelligence, expert systems fizzy sets
INTEFRATION OF CAPP WITH OTHER CA SYSTEMS
Abstract: The paper deals with possibility of integration between CAPP /Computer Aided Process Planning/ and other CA systems in engineering enterprises. It is mentioned dynamic process planning, non-linear process planning and integration CAPP and PPS system based on feedback from PPS system.
Keywords: CAPP, process planning
SELECTION OF WHEEL CHASSIS FOR MOBILE ROBOTS IN COURSE OF PRODUCTION PROCESSES AUTOMATIZATION
Ing. Ladislav Kárník
Abstract: The article presents the possibility confirmation suitable type of mobile modules (chassis) of mobile robots for the automatization of production processes. From this point of view the paper is specialized on verification behavior same types of wheel chassis at cross different obstacles. Verification is practice in system MSC/ADAMS with optimum variants evaluation. The more detailed attention is devoted to the determination suitable profile tires of wheels chassis for tested obstacles. According to type of surface and cross obstacles we can select suitable variant of wheel chassis for mobile robot or robot with extension.
Keywords: mobile robot, chassis, extension, transportation, measurement
IDENTIFICATION OF STIFFNESS MATRIX FOR LINE TYPE FINITE ELEMENTS WITH VARYING CROSS-SECTIONAL AREA
Lates Mihai Tiberiu, Jula Aurel
Abstract: The paper provides some aspects regarding the identification of stiffness matrix for line type finite elements with varying cross-sectional area; the element is loaded by an axial load and it is placed in gravitational field. Firstly, the paper presents the practical starting problem: identifying the stresses in a bar from a structure composed by a horizontal beam supported by two vertical bars with varying cross sectional area. It is presented the geometrical modeling (by attaching the local natural reference frame) and then it is written the expression of the potential energy and it is identified the stiffness matrix. Finally there are presented the results obtained from the theoretical modeling and from the finite element modeling by using specialized software.
Keywords: finite element method, stiffness matrix, bar
MYCOPHILIC OF EPIXYL-FUNGUS OF FÉNYI-ERDŐ
ISTVÁN LENTI – BÉLA KORMÁNY
Abstract: In Hungary Bátorliget (Fényi-erdő) is an unique region, where subalpine plant species live ont he plane, as the survivals of the flora of some cold, glacial-post-glacial age. The surviving was due to the local microclimatic relations.
On the area of the Fényi-erdő we registered 668 species of basidium and ascu large fungus species in 2000-2004 years.
We declared, that Daedalea quercina, D. confragosa, Diatripe disciformis, Fomes fomentarius, Fomitopsis pinicola, Ganoderma applanatum, G. lucidum, Piptoporus betulinus, Polyporus varius, Trametes suaveolens, as well a sin wider phrasing Hirneola auricula-judae and Xylaria polymorpha are infected by mycophilic fungus.
Keywords: Bátorliget, Fényi-erdő, macro-fungus, mycophilic, glacial-postglacial, oak-ash-elm gallery forests
ASPECTS REGARDING TENDENCIES IN TOOHTED GEARS MANUFACTURING AND CONTROLLING
Mircea LOBONTIU, Sándor RAVAI NAGY
Abstract: The paper tackles a few aspects regarding the current international tendencies, in the field of toothed gears manufacturing and controlling. The major companies, that operate in the field of toothed gears manufacturing tools, that of tools for toothed gears and the one of control equipment, bring a new trend in the field, a based on the new technologies trend, that regards the materials for tools and the construction of tools, a based on the new concepts trend, that regards the centres of integrated processing and of course the IT, which manifests its presence in several forms.
Keywords: gearing, technology, control, production
THE FRACTAL TECHNIQUES APPLIED IN NUMERICAL ITERATIVE METHODS FRAME
George MAHALU, Radu PENTIUC
Abstract: Many methods in the numeric calculus resolving nonlinear algebraic or differential equation but ignore some behavior of these problems. Same aspects can conjure to the fractal iterative techniques. In this paper work is performed a critical analysis about iterative fractal techniques which can conduct to various implemented applications. Study of the nonlinear equation, treated into iterative techniques, makes the subject of this paper. It consists in a short revue of the most important principles of the fractal calculus and complexity applications in fundamental sciences and technologies. If trying to solve the equation z4-1=0 in the complex plan, we can obtain the Newton’s fractal. And this is not the single case when a numeric method for solving nonlinear algebraic equations has same strange behavior. If we modify the fractal logistic equation with the goal to perform an appropriate model for some physical applications, we can obtain some interesting and amazing results.
Keywords: fractal, attractor, map, set, iterative, complexity, form
THE DETERMINATION OF THE SIGNALS WITHIN CERTAIN MEASUREMENTS THROUGH SAMPLING
Abstract: The paper describes the system of measurements through sampling, the shape on the applied shapes to one or more blocks of the system. They present the mathematical description of the ideal process of sampling in amplitude and the reconstruction possibility of the sampled signals.
Keywords: teletransmission of the samples, train of impulses, sampling function, devices called ”zero level extrapolation”
THE DISASSEMBLY PROCESSES PLANNING BY CAPP SYSTEM SYSKLASS
Abstract: New product is only rarely represented by single part; prevailingly it is complex of functionally interacted parts realized by the assembling technology. The technology of assembling is not being adequately and complexly developing in the comparison with the research in other manufacturing areas. It is also required to put the same importance to the disassembling technologies. In paper are presented the possibilities of application of computer aide d systems appears to be necessary in the field of modernization of technological preparation of production in assembling and disassembling technological areas.
Keywords: process planning, disassembly processes, CAPP systems
SUBCLINICAL DEPRESSION SYNDROME, DISFUNCTIONAL ATTITUDES AND FAMILY SOCIALIZATIONAL FACTORS AT COLLEGE STUDENTS
INNER EXCITATION CHARACTERISTICS AND MESHING STIFFNESS FUNCTION OF GEARS
János Márialigeti, László Lovas
Abstract: For studying dynamic behavior of gear trains, description of the inner excitation properties is needed. Kinematic excitation, due to meshing irregularities and profile modifications will be studied, and described by an adequate mathematical model. Dynamic excitation component, introduced mainly by the variable number of tooth pairs in contact, will be combined with the kinematic excitation function, into a general excitation function, called as reduced stiffness function.
Keywords: gear dynamics, kinematic excitation, gear meshing, inner excitation, tip relief
OPTIMALISING PLANETARY GEARS BUILT IN DRUMS WITH HIGH GEAR-RATIO
László MÁTÉ, Mihály KOZMA
Abstract: Planetary gears with internal and external toothed wheels are used to perform low weight drives of high gear-ratio. Their weight and dimensions are influenced by the number of stages and by the gear-ratio of each planetary gear. The aims of the investigation are to find the proper stages’ number and gear-ratios leading to optimal solutions where the weight of planetary gears built in drums are minimum (The outer diameters of inner toothed rings should be equal).
IONIZATION OF CUTTING FLUIDS
Abstract: The paper analyzes the effect of ionized air on cutting tools at cutting processes of structural and high-alloyed steels. It defines a field assuming exploitation and actual stage in section of evaluation performance measurements.
Keywords: Cutting fluid, cutting process, ecology, ozone
THE INTELLIGENT TRANSPORT SYSTEM IS A REALITY IN ROMANIA
Eng. George Dionisie Mihai
A NEW METHOD OF CALCULATING THE EQUATION OF THE CONNECTING ROD CURVE
Mîlcomete Daniela Cristiana
Abstract: The paper presents a new method of calculating the equation of the connecting rod curve, based on the Mathematica package. It differs from the traditional methods such as plotting the connecting rod curves of the four-bar mechanisms starting from their implicit equation form, and the harmonic analysis by determining the Fourier values, which allow for rapid stock and retrieval in the synthesis process. The examples concern general and numerical relations for different planar mechanisms.
Keywords: connecting rod curve, linear system, articulated four-bar, approximate solutions
VIBRATIONAL BEHAVIOUR ANALYSIS OF A FEMUR-THA STEM STRUCTURE USING FEA
A. Monea, G. Van der Perre, M. Gafitanu
Abstract: Vibrational analysis as a tool for monitoring and evaluating the early loosening of THA holds promise to improve the sensibility and reliability of diagnostic. This tool is based on the changes appearing in bone-implant stiffness.
Keywords: FEM – finite element modelling, THA – total hip arthroplasty, THR – total hip replacement, vibration analysis, FRF – frequency response function, cementless, prosthesis stem
COPUTER AIDED DESIGN OF FIXTURES FOR NC MACHINE TOOLS
Abstract: There are shown some tendencies in the increasing of requirement related to the quality and production cost at the manufacturing from view of Jigs and Fixtures Design in this article.
New conditions of Europe market causes that the new methods and techniques are needed to develop also in this area and the computer can help at the fixture creation, too.
Keywords: fixtures and jigs, CAD/CAM systems, coordinate systems
THE METHODS OF NC PROGRAM CREATING
Abstract: The article describes the basic methods of NC program creating, including the basic steps from part geometry creation by means of CAD system to NC program creation and the basic types of data files pipelines, which translate one data format into another in this process. It deals with advantages of these methods and with the problems, which originate in the process of creation.
Keywords: STEP-NC, ISO 6983, CNC control, CAD/CAM systems
THE KNOWLEDGE SYSTEMS IN CAD/CAM SYSTEMS
Abstract: The CAD/CAM systems development is adapted to customer requirements. The customers ask for possibility to implement their own knowledge from work experiences to the system. The necessary of time reduction in particular phases of product lifecycle requires automation of routine, identification of critical points and utilization of experiences of successfully realized projects. On the present, the development of expert and knowledge systems is associated with the CAD/CAM systems development in order to fulfill the customer requirements. The CAD/CAM systems producers have placed software systems in specific version on the market. These software systems contain the knowledge modules for designing and manufacturing aid.
Keywords: CAD/CAM system, knowledge system
LABORATORY RESEARCH ABOUT THE FORCES FOR THE STERILE ROCKS CUTTING PERFORMED AT ROSIUŢA OPEN PIT
Nan Marin Silviu, Kovacs Iosif, Mihăilescu Sorin, Andraş Andrei
Abstract: This paper shows the main laws that govern the variation of the cutting forces during the cutting operations in relation to the cutting depth, tooth undercut, laws which have been determined after laboratory tests.
Keywords: forces, cutting, rocks
THE REPLACING MATERIAL FOR AXIAL BUSH ON THE PLANETARY REDUCTION GEARS FOR ACTUATORS
Abstract: This paper normally reflects on the research regarding the preoccupations and results of the research activities and the production experience which the authors have been working in, in the area of series production of the planetary reduction gears. This paper meets the optimization necessities of the mechanic transmissions and first of all of making products of superior performances and a technical and consumption of materials and energy. In this direction we aimed, at a great change of a hint in their construction axial bush which plays a great functional part linked to tribological aspects.
Keywords: The planetary transmissions, bush sector, efficancy, fiability
WOOD DECORATIVE TECHNOLOGIES
Abstract: This contribution present how to use the project methods in practic at usage in education of students of technology. It shows how to advance the activity and creativity by suitably selected topic and problems. Describes short choice of timber decorative technologies and their utilization nearly tutorial in school frames project and troubleshooting method. It shows, how suitably selected topics and problems, as to their complexity and level of dificulty is possible to increase both student’s activity and creativity.
Keywords: Inlay, incrustation, project method, teacher’s preparation, technical education, topic, motivation, student’s interest
DETERMINATION OF FORMING LIMITS OF THIN ALUMINIUM SHEETS
Alina OGÓREK, Feliks STACHOWICZ
Abstract: An investigation concerning the mechanical properties and forming limit diagrams of the AW1050 aluminium sheets with different grain size has been carried out experimentally and analytically. The surface roughness growth with strain increasing was determined experimentally and applied to describe geometric in-homogeneity of the materials tested. The forming limit diagrams (FLD) have been determined experimentally using in-plane stretching test. The FLD were calculated based on the modified M-K theory using no fitting coefficient to describe material inhomogeneity. Calculated FLDs were compared with experimental results.
Keywords: forming limit, strain hardening, anisotropy, material inhomogeneity, surface roughness
THE ENVELOPE OF THE INDUSTRIAL ROBOT’S MOTION WITH THE END MEMBER MOTION ALONG A CONICAL AREA
Abstract: The paper is focused on the possibilities of straight line surfaces machining based on the use of a robotic system. The solving method of the presented problem is illustrated by the specific example, i.e. the movement of the end member of a robot with conical surfaces machining.
Keywords: robotic mechanism, conical surface, orientation of a robot end element, transform matrix, inverse problem
RESEARCHES REGARDING THE BEHAVIOUR OF CYLINDERS IN THE HOT-ROLL TECHNOLOGICAL PROCESS, ENVISAGE OF IMPROVING EXPLOITING ENDURANCE
Abstract: The research of thermal fatigue of the cylinders for hot-roll, constitute a novelty, and the study of its breakage and rupturing, represents one of the most important issues from the theoretic point of view, and practice, as well.
To increase exploiting endurance of these cylinders were made three types of experiments which leaded to the conclusion that the best results at fatigue were given by the hypereutectoid steel, ADAMIT – OTA – 3, type.
In the same perspective of increasing exploiting endurance, through split up decrement of thermal fatigue, was created a device to roll the surfaces of lamination cylinders’ calibers.
THE USAGE OF THE THEORY OF CONSTRAINTS ON EXAMPLE OF THE SHAFT WORKING CELL
Abstract: There is presented the practical application example of the theory of constraints, in the paper. There are described principles and stages of the production system improvement, which are based on the mentioned above theory. The particular stages will be illustrated by the example of analysis of the whole production system, which was the aim the bottle-neck finding, and examples of changes, which are executed in the shaft working cell, which magnificent oneself the bottle-neck of the analysed factory.
Keywords: modelling, simulation, theory of constraints
CONSIDERATION ABOUT WORLDWIDE TRADE EVOLUTION IN THE POST-WAR PERIOD
Viorel POP, Cecilia POP, Mircea POP
Abstract: In the postbelic period, the world-wide trade has suffered significant changes, generated by an complex of factors. The profound changes which took place in postwar period in the structure of the worldwide economy, especially under the influence of the technical – scientific revolution, in continuous deepen of the international division of work and as well as in the evolution of prices have conducted to an impressive development of worldwide trade. This paper presents the factors which have influenced the dynamics and geographic structure of world-wide trade, as well as the effects of their cumulated action, which have lent some specific features for the analyzed period.
Keywords: worldwide trade, export, prices, trade statistics, services, globalization
THEORETICAL STUDIES REGARD ING THE TRACTIVE EFFORTS FOR VEHICLES USING THE HYDROSTATIC TRANSMISSIONS
Lecturer Drd. eng. Gheorghe Popa, Lecturer Dr. eng. Ilie Dumitru, Assist. Drd. eng. Augustin Constantinescu
Abstract: The paper analyze the possibility to adapt the hydrostatic transmissions for automotive with a view to obtain the technological velocities. Using these hydrostatic transmissions we want to obtain some low technological velocities. We propose a hydrostatic transmission (supplementary) adaptable to the tractors on wheels with mechanical transmissions, realizing the calculus of the traction force and to the maximal travel velocity.
Keywords: hydrostatic transmission, traction force, technological low velocity
THE TECHNOLOGICAL PROGRESS – A VERIFICATION PROCEDURE OF CENTRIFUGAL PUMPS INDUSTRIAL POLLUTION
Prof. dr. ing. Nicolae Popa, Dr. ing. Mihai Enescu, As. ing. Onescu Constantin
Abstract: The air quality standards ask that every factory which works with toxic or risky fluids should have a control strategy, in order to be applied in the dynamic equipments. The centrifugal pumps which manage these fluids o r gases have in their structure mechanical face seals, which seal off the pump interior from the environment. The mechanical face seal building up technology represents the best verification procedure for the rotary equipments. Th is paper presents mechanical face seals projects and the liquids mechanical face seal systems applying procedure.
Keywords: air quality, mechanical face seal, advanced technology
HOT TWISTING TESTS UPON NEW TYPES OF STEELS FROM THE DACIA’S GEARBOX
Popescu Marian Teodor
Abstract: The most recent trends in high-tech of using new steel materials with special metallurgical elaboration, instead of the old steels with standard metallurgical elaboration, appear in the subject of our study. From the new (40CD4X) and old (42CrMo4) steels’ charges were extracted round short samples (L 0=5d 0) and they were tested on the universal Zwick – Rel 1875 machine, with the following regimes:
– were programmed two test speeds from the domain of quasi-static speeds;
– at every speed were programmed many temperature steps.
The results obtained, processed and analyses have reflected the superiority of the special metallurgical elaboration steel, being justified their use in the new models of Dacia’s gearboxes.
Keywords: 40CD4X steel; traction machine Zwick; mechanical resistance; test speed
DEMOGRAPHIC FEATURES OF THE BEREG PLAIN BETWEEN 1970 AND 2003
Abstract: One of the most typical features of settlement development of our ages is urbanisation. This region has one town: Vásárosnamény that has had the rank of town. The smaller villages are losing their population, at places slowly, at others more quickly. There are similar areas in the country, where similar effects are taking place. All these factors might encourage venturesome young people to stay on their homeland or even to move back. Stabilising agriculture, supporting fruit growing, or even processing fruits, local-patriots in agriculture or trade might also contribute to this force of the region. Wealth of natural conserved areas, churches from the Middle Ages, wooden bell towers and the traditions of Beregi people all ensure that this corner of the Hungarian Great Plains will live on.
Keywords: smaller villages, migration, rural tourism
REMANUFACTURING OF FEED KINEMATIC CHAINS OF HEAVY MACHINE-TOOLS
Dan Prodan, Adrian Ghionea, Anca Bucureşteanu
Abstract: The paper hereby presents theoretical and experimental research with regard to the modernization of the feed kinematic chain of heavy lathes. Pinion-rack mechanisms – either classic or hydrostatic variants – are usually provided when large longitudinal travels (over 6 m length) are needed. A new variant with ball-screw as final mechanism has been successfully applied on a 20-m longitudinal travel CNC engine lathe.
Keywords: remanufacturing, CNC engine lathe, ball-screw mechanism
ANGULAR CONTACT BALL BEARINGS – A POSSIBLE WAY FOR ELECTRICAL CURRENTS IN MACHINERY. SPECIFIC TEST RIGS
Racocea Cezar, Racocea Cristina
Abstract: The paper presents a series of specific working conditions of working angular contact ball bearing in rotating electrical machines that lead to the passing of the electrical current through bearings. The electrical current, of different intensities that passes through the bearings during working, generates a lot of negative phenomena that lead to the substantial diminution of bearings life. For study of the phenomena generated by the passing of the electrical current through bearings, two test rig have been conceived, designed and built up. The paper presents the construction and working particularities of the rigs, as well as their performances.
Keywords: Bearings Fatigue Life; Electric Current. Test rig
ANGULAR CONTACT BALL BEARINGS PASSED BY ELECTRIC CURRENT
Racocea Cristina, Racocea Cezar, Nacu Ionuţ
Abstract: The paper presents the experimental results obtained on two test rigs. The rigs are meant to investigate the phenomena connected to the passing of electric current through bearings. The research conducted under direct current on both test rigs have given evidence to the existence of a breaking through voltage of the lubricant film, after which the electric current intensity shows a tendency to continuously increase, even if the voltage remains constant or is decreasing.
The first tests conducted on the rig with two bearings under alternating current indicate a similar behavior of the bearings when they are subjected to an increasing alternating or direct current voltage.
Keywords: Bearing fatigue life; Electric current; Experimental results
CAD MODELING, MOULDS EXEC UTION FOR VULCANIZATION NONMETALLIC ELEMENTS OF NEW ELASTIC COUPLINGS
Abstract: The paper presents new constructive forms of nonmetallic elements being in component of two constructive variants of elastic coup lings with nonmetallic elements, CAD modeling of necessary moulds for vulcanizing of these forms, as well as executed forms and moulds behind designing process.
Keywords: elastic couplings with nonmetallic elements mould, modeling, designing, vulcanizing
CONTRIBUTIONS TO THE DEVELOPMENT OF A SELECTION METHOD OF EQUIPMENT IN THE FRAME OF MECHANIZED MINING COMPLEXES
Ph.D., Prof. Sorin Radu, Ph.D., Assoc.prof. Gabriel Dolea, Ph.D., prof. Iosif Gruneantu, Eng. Eugen Stefan
Abstract: The paper intends to introduce a mathematical and a graph theory in the long wall mechanized face in order to take into account as much as possible all geologic-mining condition, for growing the productivity.
Keywords: mechanized face, correlation, systemic approach, mining conditions
CUTTING TOOL AND MANUFACTURING TECHNOLOGY FOR THE INTERNAL INVOLUTE GEARS GENERATING
Sándor RAVAI NAGY
Abstract: This paper make a short presentation of the require tools and the manufacturing technologies for the internal involutes gears machining. The paper occupied just whit the generating methods without to mentioning the rest of the gear manufacturing possibilities.
Keywords: Cutting tools, Gear generating, Skiving, Hobbing whit ellipsoidal hobb, Shaving
THE RIGIDITY MATRIX OF THE DOUBLE EFFECT BALL BEARINGS
Rezmires Daniel, Racocea Cezar
Abstract: An analytical formulation to simulate the internal mechanical interactions in the double effect ball bearings is presented. The individual constructive particularities of the double effect ball bearings were considered. Many scientists consider that there are no differences between the cases when the inner ring or outer ring is considered rigid, but, these differences exist and are evidenced if the rigidity matrix is correctly constructed in 5 DOF.
Keywords: Double Effect Ball Bearings, Rigidity Matrix, Outer Ring Rigid (ORR), Inner Ring Rigid (IRR)
FLYING TESTS OF CONTROL SYSTEM IMPROVING AIRCRAFT’S HANDLING QUALITIES
Tomasz Rogalski, Bogusław Dołęga
Abstract: The paper presents results of flight tests of aircraft control system SPS-1. The described control system has been created as a system improving aircraft’s handling qualities. During tests several control algorithms were tested. Pilots rated aircraft’s handling qualities and were ordered to point control system they liked the most. Additionally original methodology allowing to rate and compare aircraft’s handling qualities was tested. It used pilot’s workload factor and control’s precision to rate aircraft’s handling qualities.
Keywords: handling qualities, control system, aviation
UNITY IN DIVERSITY AND DIVERSITY IN UNITY. ROMANIA BETWEEN THE WESTERN EUROPEAN AND ORTHODOX VALUES AND NORMS
STUDY REGARDING IMPROVEMENT OF EXPORT OF PRODUCTS ACTIVITY THROUGH FUNDAMENTAL ELEMENTS’ KNOWLEDGE OF EXPORT AND MARKETING ON WESTERN AND AMERICAN MARKETS
Eng. Rusan Traian, Eng. Felicia Gabriela Portasă
Abstract: Exporting and marketing of one company’s products and goods demands an understanding of the target country’s economic and market characteristics, and law regulations, as well. Very often tough, selling your products succesfully from an Eastern European country to Western ones or to America, demands knowledge of a bigger amount of elements. This paper develops the most important factors that lead to success growth in products export activities.
TESTING OF ELECTRO-MECHANICAL ACTUATORS
Abstract: Power-By-Wire (PBW) technology seems to be the next major step in development of the aircraft control. In this solution control power comes directly from the aircraft electrical system to the Electro-Mechanical Actuator (EMA) which assembles the electric motor, controller and gearbox. Testing of servos actuating airplane control surfaces has been presented herein. Testing method and laboratory results have been also described. Then the in-flight testing results of the complete set of servos installed as a part of SPS-1 system on board of an airplane have been presented. SPS-1 is experimental Fly-By-Wire control system for general aviation aircraft designed as a project financed by Polish State Committee for Scientific Research (2004-2006).
Keywords: electro-mechanical actuator , Fly-By-Wire, aircraft, tests
CONTRIBUTION TO DISCRETE STRUCTURAL OPTIMISATION
Milan Saga, Roman Kocur, Vladimir Dekys, Milan Zmindák
Abstract: The goal of our paper is to present the application of the new discrete optimisation algorithms to structural mass minimissing subjected to the prescribed fatigue damage or life. This study considers the structural analysis (mainly shell structures) by finite element method, multiaxial rainflow counting, fatigue damage prediction and sizing optimisation process. It will be analysed a mechanical systems under random excitation in time domain. The new optimising approach will be implemented into solution program OPTIM_FAT.M (in Matlab).
Keywords: optimising process, finite element method, multiaxial rainflow analysis
HOW TO TEACH THE FUNDAMENTALS OF INFORMATION SCIENCE, CODING, DECODING AND NUMBER SYSTEMS?
Abstract: The Introduction of Informatics subject deals with the rudiments of informatics within the education system of the College of Nyíregyháza where informatics teachers and programmer mathematics are trained as well. The problem that made us examining the subject is that there has been high rate of failed exams in this subject since years. In the first semester of 2004/2005 the 83% of the examinees failed at the first exam and after the 2nd, 3rd or 4th exam still the 47% of the students were unsuccessful.
The aim of this paper is to a) introduce the content, the requirements and the concrete exam requirements of the Introduction of Informatics subject, b) the mathematical background of the exercises and c) the solutions of one basic exercise of the test. Based on 646 test papers we try to determine the most common mistakes and based on the experience we make suggestions.
Keywords: informatics, education, numerical systems
The exhast valve with ceramic deposition simulation reaction and that of entirelly made from ceramic
Ioan Radu Şugar
Abstract: Studyng the internal combustion engines tendencies and direction it is noticeable that the major effort must be directed towards finding new constructing and energetic solutions aimed to improve the thermic efficiencig and implicitly to diminish fuel consumption. Generally speaking there are two ways of approading for the ceramic materials usage in combusion chambers arhitecture.
OPTIMIZATION OF MAIN TECHNOLOGICAL PARAMETERS AFFERENT FOR THE MINING METHODS
Surulescu Daniel, Stamin Purcaru Ion, Chiril Gheorghe, Irimie Sabina
Abstract: Utilization of mining methods with undermined coal bank in the case of thick coal seams in Jiu Valley coal basin has lead to the increase of efficiency obtained and to significant decrease of production costs, but the establishment of coal fields has been made without performing an accurate analysis regarding the influence of main technological parameters’ variation of this method (length of face line ,,lab”, length of face field ,,lp”, and the thickness of undermined coal bank ,,hb”) onto the achieved technical and economical indexes.
Keywords: optimization, model, methods, coal, costs
THE EXAMINATION OF PENETRATION VALUES FOR LOAMY SOILS, AND THEIR CONVERSION INTO AN IDENTICAL HUMIDTY LEVEL
Abstract: Soil resistance is measured by penetrometer, which is one of the commonest ways of examining changes in the physical state of the soil in space and time, the position of the compacted soil layers. However, examining the effect of cultivation we conclude from the soil resistance into soil compactness, it is indispentable to know the humidity values of the soil. In Hungarian practice comparing various treatment, the nearly equal soil humidity values are compared, therefore a part of values is lost for evaluation. A new method to overcome this problem was invented, when the soil resistance values at various soil humidity are converted into the ones at identical humidity values.
TECHNOLOGY AND ENGINEERING – MODERN FACTORS OF PROGRESS
Prof.dr.eng. Vasile ŢIPLEA
Abstract: The paper discusses the importance of some future technologies as decisive factors of the interaction between science and civilization.
It also deals with the resulting technological intercourse between technology and civilization.
Engineering and technology stand out as an issue of great importance and the paper contributes to settle their scientific definition.
Keywords: engineering, technology, software, diagnosis, personnel, material endowments
OPTIMISATION OF ELECTRIC POWER CONSUMPTION BY REHABILITATING THE COMPRESSOR STATIONS
Ing. Ştefan Troacă, Ing. Daniel Surulescu
THEORETICAL RESEARCHES REGARDING THE KINEMATIC POSSIBILITIES FOR THE THREE PLAN BARS MECHANISMS
Lecturer dr. eng. Cezar-Alin UNGUREANU, Lecturer drd. eng. Gheorghe POPA
Abstract: In this paper some results obtained using procedures and computational programmes for the drawing of coupler curve for three linked plan bars R-RTT mechanism are presented. There are showed some of the trajectories for a coupler point obtained with computational programmes applied to the three bar linkages. The programmes calculate and the perimeter of the obtained curves, variable that constitute the first indication in these curves identification.
Because it is possible to modify both the element’s dimensions and the position of the tracing point, the range of these trajectories can be extremely diverse. The programmes, allow the finding a numerous groups of solutions, which can be registered into bi-dimensional vectors, forming that way a base of data.
Keywords: mechanism, dyad, computational programmes, trajectories
EFFECT OF MUNICIPAL SEWAGE SLUDGES ON CO2 PRODUCTION OF SOIL
Csaba Varga, Zsuzsanna Uri
Abstract: CO2 production of soil from variously treated municipal sewage sludges from three
big cities in Hungary was studied in pot experiment. Although all the three sewage sludges
resulted higher CO2 production in soil than the control treatment, but no significant
difference was found between the effect of sludges dosage rates on the soil CO2 production.
Keywords: CO2 production, municipal sewage sludge, fodder pea (Pisum sativum L.), heavy
THE RELATION BETWEEN QUALITY AND SAFETY OF INDUSTRIAL HYDRAULIC SYSTEMS
Emanoil VENESCU, Marius MINCA-CASIAN
Abstract: The hydraulic industrial systems are more and more widely utilized in the fields of industry, due to their obvious advantage. Their quality requirements and the need to fulfill hard safety criteria are subject of serious concerns in their success and competitiveness. Their safety is translated also in the safety of industrial systems in which they are implemented. (chemical, nuclear, energetic, mining etc). The paper deals with aspects related to the interdependence between the fulfillment of quality requirements and safety ones, taking into account the balance of decision between investing in quality and acceptation of a certain safety level.
Keywords: fluid power systems, safety, risk assessment