bluuebunny/crossref_metadata_2025 huggingface dataset:
Experimental Analysis Regarding the Degree of Plastic Deformation of Fractured Surfaces under da/dN, KIc and JIc Determination
Authors: Goanta Viorel
Published: October 2014

When loaded over their yield strength, materials suffer significant plastic deformations. In such zones, the degree of plastic deformation depends on the characteristics of the material and also on the nature of the loading. As known, the degree of plastic deformation may be correlated with the value of hardness, determined in the plastically-deformed zone. The present paper discusses the three types of testings applied, which led to the fracture of some specimens and, consequently, to plastic deformations in the immediate vicinity of the fractured surfaces. The testings, performed on Compact Tension Specimens, aimed at determining the following characteristics developed by the Mechanics of fracture: the crack growth rate, da/dN, fracture toughness for materials with brittle behavior, KIc, and fracture toughness for the materials with a preponderantly ductile character, JIc. Along the surfaces fractured during these testings, plastic deformations occur, differentiated exactly by the load differences. Under such conditions, testings were made upon the 1C45 (1.053) steel, with the characteristics established by the manufacturer, as well as upon the same steel, yet subjected to an annealing thermal treatment, and the variations of Vickers hardness were recorded both along the fractured surfaces and from one specimen to another.
Influence of Non-Linear Properties of Fluid Viscoelastic Properties on Seismic Damping Properties of a Ten Stories Building Using ANSYS Program
Authors: Ionescu Adriana , Negru Mihai , Burada Cristian
Published: October 2014

This paper presents the simulation of the influence of viscoelastic fluid dampers, with nonlinear damping properties, on damping property of a ten stories building structure. The study was made using Finite Elements Method and ANSYS program, on a 3d F.E.M. model. In order to obtain the influence of different types of damping nonlinearities of the viscoelastic fluid dampers on the damping property of the entire structure, there were made different types of simulations using modal analysis and seismic time history analysis. The graphics obtained can be used for determining the nonlinear features of fluid dampers for achieving different degrees of seismic energy dissipation for the analyzed building.
Experimental Determinations and Comparative Studies of the Stiffness for Some Sandwich Bars Reinforced with Metal Fabric
Authors: Miriţoiu Cosmin Mihai , Stănescu Marius Marinel , Bolcu Dumitru , Stanimir Alexandru , Manea Ion
Published: October 2014

In this paper, starting from the eigenmodes values determined in [1], a method, used to determine the stiffness of the composite bars with honeycomb or polypropylene core reinforced with metal fabric (having two layers of metal fabric, in the upside and downside parts), is presented. The eigenfrequency is used to determine the stiffness (the hole stiffness and the stiffness per unit mass). The results are validated by another experimental method, characterized by embedding the bar at one end and let it free at the other end. The free end is loaded with weights and the displacement is measured with a dial gauge with magnetic stand. Comparisons with the stiffness values obtained from the eigenmodes are made and the errors between the two methods are determined. In the last part of the paper, some comparisons between these composite bars and other bars previously studied by the authors are made.
Researches Concerning Friction Influence on Material Cold-Hardening in High Precision Stamping
Authors: Butnar Lucian Adrian , Sugar Ioan Radu
Published: October 2014

The paper studies the cold-hardening phenomenon of material in high precision stamping. Level of material cold-hardening can be evaluated with thickness of cold-hardening stratum Δg (that may reach 0.2mm) and with its toughness (that may increase up to 1.8 times). For a correct conducing of high precision stamping process, is need to know, from designing stage, the way that different factors influence the piece material cold-hardening.The paper proposes the cold-hardening index IE that characterizes global and correct the cold-hardening level of stamped material. It was studied, for a large range of metallic materials (non-ferrous, carbon steels and allied steels), the way that tool-piece friction which varies from dry friction (μ=0.5) to limit friction (μ=0.05) influences value and evolution of cold-hardening index IE. The remark is that a reduced tool-piece friction goes to cold-hardening index IE increasing.
Influence of the Contact Pressure on the Rolling Resistance Moments in Dry Ball-Race Contacts
Authors: Dumitrascu Alina Corina , Ianus Gelu , Olaru Dumitru
Published: October 2014

Based on a theoretical model and an experimental methodology for defining the rolling resistance moments in a modified thrust ball bearing having only 3 balls, the authors experimentally investigated the influence of the Hertzian contact pressure on rolling resistance moments between a ball and a race. The experiments were realized with balls having diameters between 1.588 mm and 4.762 mm with maximum Hertzian pressure between 0.2GPa and 1GPa, operating for rotational speed between 60rpm to 210 rpm. The experiments evidenced that the measured values of the rolling resistance moments have higher values that the theoretical hysteresis and curvature rolling resistance moments for low contact pressure. By increasing of the contact pressure to 1GPa the experimental values for rolling resistance moments are in good agreement with the theoretical models.
About an Experimental Modeling of Steel Surfaces Wear in Injection of Plastic Composites with Short Glass Fibres
Authors: Rus Dorin , Capitanu Lucian , Florescu Virgil
Published: October 2014

Consequences of the wear processes at screws and barrels of injection machines and extruders for processing of plastics reinforced with short glass fibers, arise after a longer time (10,000 cycles). Because of this they are working that through appropriate modeling attempts on the profits to be obtained in a short time as much information relating to both the mechanisms of wear and its size, so that the effect can be easily confuted in practice. Starting from the idea that the greatest pressure and velocity of composite melted is in the die nozzle, was an experimental nozzle with wear samples of sizes and weights which can be measured with precision as good. For a larger accuracy of measurements, we used a method for radiometric measuring, extremely accurate. Different nitriding steels have been studied as nitriding treatments, as well as some special steels and alloyed steels. Besides these, there have been preliminary attempts made to describe and checking corrosive action of thermoplasts on metals. This was another way of checking the wear testing of the samples semi-cylindrical wear samples, which served to simulate the wear of the top layer of the barrel and screw. The first results showed that wear increases depending on the increased pressure. One of the findings is that in similar conditions of injection, with the same content of glass fiber, polyamide 6.6 produces a wear greater than polycarbonate. It was also found that increasing the concentration of glass fibres increase the surfaces wear of barrels and screws.
Experimental Rig for Measuring Lubricant Film Thickness in Rolling Bearings
Authors: Zhang Xing Nan , Jablonka Karolina , Glovnea Romeo
Published: October 2014

Electrical capacitance has been applied in the past for measuring the lubricant film thickness in rolling element bearings. The main difficulty arises from the fact that the measured capacitance is a combination of the capacitances of many rolling elements, which come in contact with both the inner and outer rings. Besides, the capacitance of the Hertzian contact itself and the surrounding area must also be separated. It results in a complex system which, in order to be solved for the film thickness at a particular location on the bearing many approximations have to be made. In the present study the authors use an experimental rig in which the capacitance of a single ball can be isolated. Moreover the capacitance of the ball – inner ring and ball – outer ring contacts can be measured separately.
Analysis and Simulation of Gait Types with Blocked Joints
Authors: Baritz Mihaela , Cotoros Laura Diana , Barbu Daniela
Published: October 2014

The analysis of gait cycle represents for the professional in biomechanical field a source of information concerning the normality status, comfort degree in carrying out various activities, existence and manifestation of some loco-motor malfunctions, manner and degree of recovery/rehabilitation after surgery and many other applications. From this point of view, computerized simulation with respect to the anthropometric dimensions and the type of action represents an efficient and flexible manner for analysis and evaluation or even for creating a comparative algorithm between different situations or stages of motions performed by the locomotion system. Thus, some general aspects concerning the human locomotion system, the physiological and anatomical limits are presented in the first part of the paper. The analysis and simulation methodology for various gait types, also the experimental system used for recording and then processing the data obtained from these simulations are described in the second part of the paper. In order to complete the developed structure, these options of gait cycle were simulated by the computer, using dedicated software, either by blocking the hip joint or the knee joint, then they were correlated with the normal ones. The results and conclusions of these simulations and recordings on a target group of 10 subjects without locomotion malfunctions but simulating the blocked joints were presented in the final part of the paper.
Experimental Measurement of Flexion-Extension in Normal and Osteoarthritic Knee during Sit-to-Stand Movement
Authors: Tarniţă Daniela , Calafeteanu Dan , Matei Irinel , Tarnita Dan
Published: October 2014

The aim of this paper is to compare the range of motion of the sit-to-stand (STS) movement angles for the both knees: osteoarthritic (OA) left knee and healthy right knee, for seven subjects who performed an experimental test consisting of STS cycles on a chair. The acquisition system consists of two electro-goniometers, one for each leg, for making possible the simultaneously reading of data during experiments. The angular amplitudes of human knee flexion-extension during the STS cycles are obtained as data files. For each knee of all subjects were selected 8 consecutive cycles which were normalized by interpolation with cubic Spline functions, using MATLAB environment. The final medium STS cycle for both knees is obtained. Finally, statistical analyses are made and the results are presented. The maximum values of the knee angle for both knees of all seven subjects were compared and tested with an unpaired Student t-test, considering α=0.05. The p-values corresponding to this test are calculated using ANOVA. Based on the average anthropometric data the virtual model of a mannequin using SolidWorks software was developed, and then was transferred to ADAMS simulation environment in order to obtain the variation laws of reaction forces in the lower limb joints.
Proportional Hydraulic Flow Control Valves with Simple and Differential Command
Authors: Avram Mihai , Bucşan Constantin , Duminică Despina , Popescu-Cuta Alina
Published: October 2014

The paper brings in an original solution of proportional hydraulic flow control valve, which can function with both simple and differential command. The static adjustment characteristic of this equipment is analyzed. Also, two systems that integrate the discussed equipment are taken into account.
Transmission Indices Adoption for 6R Structural Group
Authors: Duca Cezar , Buium Florentin
Published: October 2014

This paper continues some ideas accepted in scientific literature or enunciates by us in previous papers. As title indicates, we treated the case of 0/3/3 structural group with revolute joints, and application of this group in mechanisms. Three different proposals were done and discussed for the forces transmission indices. Finally an application was shown for a mechanism used in a leather ready-made industry.
Designing Search and Rescue Robots towards Realistic User Requirements
Authors: Doroftei Daniela , Matos Anibal , de Cubber Geert
Published: October 2014

In the event of a large crisis (think about typhoon Haiyan or the Tohoku earthquake and tsunami in Japan), a primordial task of the rescue services is the search for human survivors on the incident site. This is a complex and dangerous task, which often leads to loss of lives among the human crisis managers themselves. The introduction of unmanned search and rescue devices can offer a valuable tool to save human lives and to speed up the search and rescue process. In this context, the EU-FP7-ICARUS project [1] concentrates on the development of unmanned search and rescue technologies for detecting, locating and rescuing humans.A main factor which explains why there is so little robotic technology applied on the terrain in real-life search and rescue operations, is that the complex nature and difficult operating conditions of search and rescue operations pose heavy constraints on the mechanical design of the unmanned platforms. In this paper, we discuss the different user requirements which have an impact of the design of the mechanical systems (air, ground and marine robots). We show how these user requirements are obtained, how they are validated, how they lead to design specifications for operational prototypes which are tested in realistic operational conditions and we show how the final mechanical design specifications are derived from these different steps. An important aspect of all these design steps which is emphasized in this paper is to always keep the end-users (in this case the search and rescue workers) in the loop in order to come to realistic requirements and mechanical design specifications, ensuring the practical deployability [2] of the developed platforms.
Modal Analysis of a MEMS Cantilever
Authors: Popescu-Cuta Alina , Ionascu Georgeta , Donţu Octavian , Avram Mihai , Comeaga Constantin Daniel , Manea Elena
Published: October 2014

Micro-Electro-Mechanical Systems (MEMS), also known as micromechatronic devices, integrate on the same chip (substrate) both micromechanical structures and microelectronics components. Microcantilevers are miniaturized beams clamped at one end and with the other end suspended freely outwards. They can be used as resonant structures in nano/micro mass detectors, allowing a quantitative assessment of the (substance) mass attached to these devices. An accurate modal analysis makes possible to estimate the sensitivity of the cantilevers or their ability to detect minimum frequencies shifts induced by the substance absorption. In order to obtain a high sensitivity, the structures must present high resonant frequencies (usually bending or torsion), in close correlation with a small equivalent mass. This paper deals with the vibration testing, modeling and simulation of a silicon rectangular microcantilever, micromachined through MEMS technologies. The results of analytical calculations and numerical computation by finite element analysis (FEM) have been compared with those measured through Laser Doppler Vibrometry (LDV) method using MSA-500 system from Polytec.
Gripper System for Handling the Book on the Library Shelf Out
Authors: Spanu Alina , Avram Mihai , Bucsan Constantin
Published: October 2014

The paper deals with a method applied for handling the book on the library shelf out by using a specialized gripper. The main advantage is the gripper positioning along the symmetry axis of the founded book spine, so that the fingers controlled with high accuracy could retrieve it. The vision camera has been used for processing the information, so that we have written the software using Microsoft Visual Studio. The proposed method may find out the room existing between nearby books as well as the one needed along the vertical axis. The required room for movement has the minimum value due to the bottom finger thickness and the vertical displacement is proposed mainly.
Method Used to Identify the Optimum Gripping Surfaces for an Injection-Molded Part
Authors: Tocut Pavel Danut , Tripe Vidican Calin , Tarca Ioan Constantin , Bungau Constantin
Published: October 2014

This scientific paper conceived by the authors describes how to implement and use a new method to quickly identify the optimal gripping surfaces during molding injection of a stove handle. By conceiving, realizing and implementing of an expert system suitable for such robotized operations frequently used in injection systems of plastics, a scientific basis of quick and exact identification of the optimum gripping surfaces is made, calculating precisely the coordinates of the points in which the suction cup axles of the end effector are perpendicular on the surfaces.
Some Aspects Regarding the Mathematical Modeling and Dynamic Simulation of a Single Stage Helical Gearbox
Authors: Korka Zoltan Iosif , Miclosina Calin Octavian , Cojocaru Vasile
Published: October 2014

Gears are frequently used in mechanical systems for power transmission, speed variation and for changing their operating sense. Mathematical modeling of gear transmissions offers a better understanding of their dynamic behavior. A significant amount of literature and studies are available in this field. Because the gears are critical components of any rotating machine, they have received considerable attention regarding their mathematical modeling, being published a lot of papers concerning this problem. The purpose of this paper is to present a mathematical model for studying the dynamic behavior of a single stage helical gearbox. Based on the proposed mathematical model and using specialized software, a numerical simulation of the gearbox dynamics will be performed. Simulation results will be compared with data obtained experimentally-obtained data.
On the Synthesis of a Five Bar Linkage for Linear Trajectory Using a CAD Analysis
Authors: Moldovan Cristian Emil , Sticlaru Carmen
Published: October 2014

This paper demonstrates how to use CAD Software (Pro/ENGINEER in our case) to generate a cam profile. This cam will be used in a five bar linkage for which the input elements are synchronized through a cam-follower mechanism. The cam profile is generated so that the five bar mechanism produces a certain curve. The paper presents the synthesis method after which a simulation is executed to verify the results.
Using Neural Networks to Modeling Vehicle Dynamics
Authors: Alexa Octavian , Ilie Constantin Ovidiu , Vilău Radu , Marinescu Marin , Truta Marian
Published: October 2014

This paper is the result of a research program which focused on the statistical dynamics of vehicles. Most of the inputs of man-machine-field system have a random variation, so a systemic and statistical analysis of vehicle dynamics is obvious. In our study, data were obtained by measuring the dynamic parameters of vehicles and engines. Testing program aimed to capture a large range of operating regimes. To analyze the data the authors have used neural networks. There was adopted a NNARX (Neural Network Auto-Regressive with eXogene inputs) model with 4 inputs, 5 hidden units and 1 output. It can be concluded that the development of mathematical modeling using non-linear neural network can ensure the desired accuracy, conveniently is obtained by increasing the number of neurons in the hidden laws.
Experimental Study on the Influence of Certain Parameters over Vehicle’s Dynamic Behavior
Authors: Bivol George , Ene George , Radulescu Marian Eduard , Iacob Mihai , Copae Ion
Published: October 2014

Tougher request that are being formulated again and again regarding a vehicle’s dynamic performances and its fuel efficiency require a deeper study over the influence of various parameters over to the vehicle dynamic behavior. In the specialty literature we find appreciations both quantitative and qualitative regarding the influence of certain functional parameters, and how their adjustments have an impact on to the vehicle’s performances. We have to mention that the literature guides its self when analyzing the influence of certain parameters after a very restrictive methodology: when studying how a parameter influences a certain behavior all the other parameters are considered to be constant, which obviously does not happen in reality.
Human Head-Neck System Behavior during Virtual Impact Automotive Simulations
Authors: Ciunel Stefanita , Popa Dragos Laurentiu , Gherghina George , Bogdan Mihaela Liana , Tutunea Dragoș
Published: October 2014

The paper presents the studies made on a similar biomechanical system composed by neck, head and dummy body components. The models were defined in a CAD environment which includes Adams algorithm for dynamic simulations. After simulation was obtained the entire mechanical behavior based on data tables or diagrams. That virtual model composed by neck and head was included in complex system (as a car system) and supposed to impact simulations (virtual crash tests). This paper presents issues concerning the use of CAD systems in modern technology virtual prototyping, in this case a complex virtual model for a car system used for impact simulations. Virtual prototyping is a process that uses a virtual prototype instead of the physical prototype for testing and evaluating specific elements of the designed product. Virtual prototype is created on the computer closer to the actual characteristics and operating conditions so as to allow the simulation to perform the role for which it was designed. The three-dimensional model has been exported into simulation software able to perform kinematics simulations and finite element analysis, at the same time. With that virtual model were analysed different situations similar with car crash. Results of simulations have been analysed and can be compared with measurements made on the experimental device (under construction).
Researches Regarding the Use of Bioethanol at the Supercharged Spark Ignition Engine
Authors: Obeid Zuhair H. Obeid , Pana Constantin , Negurescu Niculae , Cernat Alexandru
Published: October 2014

The general objective of the researches is use of bioethanol at the supercharged spark ignition engine for improving engine efficiency, improving performance of power and torque and decreasing of the emissions level. Bioethanol is a very good alternative fuel for supercharged SI engines because of its better combustion proprieties comparative to the gasoline; it has a higher combustion velocity, a high resistance to the combustion with knock and can be used and as a cooling agent of the intake air. By achieving these specific objectives this paper brings important contributions to improvement the SI engines performance. The paper presents results of some theoretical and experimental investigations on a 1.5 L supercharged SI engine fuelled with gasoline-bioethanol blends. At the theoretical research, the physical – mathematical model uses a Vibe combustion formal law and for combustion with knock avoiding the combustion duration is established shorter than end-gas auto ignition delay evaluated by Douaud and Evzat equation. Is established an optimum correlation between the engine air boost pressure, spark ignition timing, dosage, air boost temperature and energetic performance for to the avoiding of knocking phenomena. The theoretical and experimental investigations show that the improvement of the combustion process by use the bioethanol at the supercharged spark ignition engine leads to the reduction of BSFC (with 5% at the stoichiometric dosage), to the accentuated reduction CO and HC (with 5% and 13% respectively at the same dosage), due to a lower C content and better combustion properties of the bioethanol. In same time, the NOx emissions level significantly decreases (with 7% at the same dosage) because of the local cooling effect produced by bioethanol vaporization.
COSRING-LUJET, Integrated New Concept in Automotive I.C. Engines for a Better Lubrication
Authors: Rakosi Edward , Manolache Gheorghe , Talif Sorinel Gicu , Balanescu Dan Teodor
Published: October 2014

The COSRING-LUJET is a new concept for integrated solution to improve the lubrication regime in internal combustion engines. Introducing a conical shape for the peripheral surface of the rings, the authors analyze the conditions for the lubrication regime. Under this new concept, entitled COSRING, has developed a method for determining the transversal profile of the first and the second compression ring in order to obtain a better lubrication conditions for the piston ring – cylinder line assembly. On the other hand, the authors analyze the main factors affecting the cam-follower contact conditions, emphasizing the influence of the lubrication regime conditions over the couple wear reduction. The LUJET concept, proposed and studied by the authors, is an original solution for the improvement of the lubrication regime and engine life by using additional oil jets directed over the contact area.
Theoretical and Experimental Analysis on Use of Alternative Fuels for Internal Combustion Engines
Authors: Uzuneanu Krisztina , Burciu Burciu
Published: October 2014

The drastic decrease in the world energy resources along with the statement that the modern culture and civilization simply cannot exist without energy and therefore, due to its very existence, it is a big energy consumer, has become an axiom. The increasing number of inhabitants on the planet and consequently the increased amount of necessary energy has determined the researchers and scientists to search deeper into other possible sources of natural energy such as: wind, sun, water, geothermal, tides, atom energies. The work presents some characteristics of injection and burning of the rape oil for Diesel engines and the mixtures of ethanol with gasoline for spark ignition engines.
Corrosion Behaviour of a Cermet Deposited Coating in Sulfuric Acid Solution
Authors: Barca Alexandru , Istrate Bogdan , Barca Eduard Sebastian , Crismaru Vasile Ionut , Munteanu Corneliu
Published: October 2014

Gas oil is the fuel used in internal combustion engines with ignition through compression. This fuel contains various amounts of sulfur, an element that can contribute in the process of combustion to the forming of sulfuric acid on the internal walls of the cylinder. Sulfuric acid is a highly corrosive substance which can lead in time to the deterioration of the functional surface of the motor cylinder. For an accurate evaluation of the analyzed coatings a study was carried out on the resistance to sulfuric acid corrosion of the two coatings of Al2O3 30(Ni20Al) and NiAlSi. To this purpose a solution of sulfuric acid with a 30% concentration was used. The samples were immersed in sulfuric acid for 70 hours.
Numerical Study Regarding the Flow Movement in Natural Convection in an Asymmetrical Heated Vertical Channel
Authors: Burlacu Andrei , Verdeș Marina , Ciocan Vasilică , Popovici Cătălin George , Balan Marius Costel , Tofan Bogdan Andrei , Pastrav Dragos
Published: October 2014

The present paper presents a numerical study, regarding the dynamics of movement in natural convection in an asymmetrically heated vertical channel. The channel was immersed in a tank filled with water at a temperature of 15 °C. The study focuses on one hand, on the radiated heat output from the heating plate, and on the other hand, on the thermo-physical boundary conditions from the inlet and the outlet of the channel. These aspects give great problems in natural convection if limited to a single channel as a field of study.The conservation of mass, momentum and energy equations are solved with the method of finite volumes. Numerical simulations are performed using the commercial computer program Ansys Fluent ® CFD (Computational Fluid Dynamics).
Self-Sustained, Independent Trifold Solar Energy Conversion System for Isolated Locations in Hot Climate Areas
Authors: Popescu Aristotel , Panaite Ema Carmen , Lupu Ana Georgiana , Atanasiu Marius , Vlachokostas Christos , Michailidou Alexandra
Published: October 2014

This paper proposes two configurations for a hybrid solar energy conversion device that can be used as a self-sustained, independent power generation system in isolated locations in hot climate areas. Given the strong dependence of photovoltaic cell conversion efficiency on operation temperature, the cooling of the backside becomes imperative, increasing not only electrical, but also the overall solar energy conversion efficiency. The hybrid system provides now electricity and hot hater for domestic applications. To further improve electrical efficiency, a thermoelectric generator module is added to the system, harvesting the thermal energy that otherwise would be regarded as waste heat and rejected to environment. The optimization of the parameters that influence the total efficiency demonstrate the strong connection between the three parts of the system, PV-TE-DHW.
Integrated System for Producing, Transporting and Consuming the Unconventional Energy for a Residential Building
Authors: Popovici Cătălin George , Balan Marius Costel , Verdeș Marina , Ciocan Vasilică , Burlacu Andrei , Tofan Bogdan Andrei
Published: October 2014

The possibility of incorporating several subsystems using successive, in parallel or combined links, in a complex system with a well-defined goal, has given the possibility of proposing a new model for the integrated system - in series – in order to assure the heating and domestic hot water independence of a residential building, and in order to use the Retscreen International software, to simulate its functioning. An integrated system, can be conformed in several ways, each scheme having some technological, organizatorical variants, but with different economic effects. In choosing the optimal variant of a category of installations, there are used some techniques of analysis the economic performance. In the simulation of the functioning of the integrated system which assures the heating and the domestic hot water there have been proposed a series of work parameters, namely: the destination of the building, the climatically zone, the demand of hot water, the medium demand of thermal energy concordant to the climatically zones, the cost of natural gases, the price of the wooden fuel, the inflation rate, the service duration of the equipment, the cost of system’s maintenance, etc.
Numerical Study of the Efficiency of Flat Plate Solar Collectors in Different External Conditions
Authors: Popovici Cătălin George , Hudisteanu Sebastian
Published: October 2014

In this paper is presented a numerical investigation of efficiency of the solar thermal panels for different external conditions. The aim of the study was the analysis of flat plate solar panels that are placed in a temperate zone, such as the climate of Romania. The opportunity of the study is proven by the growing tendency in using renewable source of energy and especially of the solar thermal one. The variables considered in the study were the inlet flow rate, external temperature, air velocity and intensity of solar radiation.
Study of Height Influence of Heat Exchanger Tanks on Overall Pressure Drop
Authors: Rus Alexandru , Martian Vlad , Nagi Mihai
Published: October 2014

In the context of a constant demand of more compact and efficient heat exchangers, the need for thoroughly researching the influence of the construction parameters impact on heat exchanger's performances arises. The purpose of the paper is to present the numerical results of such a research, carried out at RAAL S.A. with the support of "Politehnica" University of Timişoara. The research consists of assessing the effects of the geometric characteristics, the height in particular, of the inlet and outlet tanks of a water cooler on overall pressure drop, through Computational Fluid Dynamics. The structural complexity of heat exchangers demands that the analysis be divided into multiple, less complex models, in order to achieve accurate and truthful results within a reasonable amount of time and use of computational resources. The paper also focuses on developing a viable method for accomplishing numerical analyses on heat exchangers' parameters.
Hydrogen Production by Anaerobic Digestion of Biomass with High Lignocellulose Content - References Selection Procedure
Authors: Teleky Bernadette Emöke , Balan Mugur Ciprian
Published: October 2014

The manuscript presents an objective and rigorous references selection procedure for a literature review concerning the state of the art in the field of bio-hydrogen production by anaerobic digestion of biomass with high lignocellulose content. The references selection procedure is presented in detail, with stages and different including and excluding criteria. The scientific databases and the key words used for their interrogation are also presented. The methodology of references selection consists of the following steps: automatic scientific databases interrogation, manual selection of references from the automatic interrogations results based on titles and abstracts, addition of new references based on study of references list from the previously selected papers, addition of references representing Romanian contributions and selection of papers based on preliminary study of their content. The main obtained results based on preliminary analysis of the selected references consist in presentation of the first published references, of the newest references and of the most cited references. It was highlighted that the trend of publication in anaerobic digestion of biomass with high lignocellulose content with the scope of hydrogen production, is in continuous increasing interest worldwide.
Theoretical Analysis of the Entropy Flow Generated by the Fluid Flow with Friction and Heat Exchange
Authors: Vartolomei Haralambie Mihail
Published: October 2014

Generating entropy is a measure of the irreversibility of a system or of its component. Any measure for minimizing the generation rate of entropy in a component of a system leads to reducing the irreversibility of the system’s assembly. We are interested into the entropy generation minimization procedure, which is the basis of the thermodynamic design.
Researches Regarding the Improvement of the Design for Vineyard Spraying Equipment
Authors: Tenu Ioan , Diaconu Andreea , Rosca Radu , Rittner Tibor
Published: October 2014

Pest and disease control in vineyards and orchards is a key feature for obtaining healthy and economically efficient crops, spraying equipments being widely used for plant protection. The technical performance of the spraying equipment has a significant effect over the efficiency indices of the plant protection methods: specific consumption of chemical solution, working capacity of the spraying units, fuel consumption, homogeneity of distribution over the entire foliage system etc. In this paper a new design of the vineyard spraying equipment was investigated, aiming for the partial recovery of the chemical solution, which otherwise would be lost; thus the consumption of chemical substance was decreased. The sprayer was equipped with recovery panels, mounted sideways, in order to retain the liquid droplets which would otherwise pass through the foliar system. The above-mentioned system can be mounted on different types of universal vineyard spraying machines. The laboratory tests confirmed that the consumption of liquid substance was significantly reduced, while the working parameters of the spraying equipment were not affected.
Nonlinear Oscillations of a Mass with Cubic Stiffness, Harmonic Excitation and Dry Friction
Authors: Stanescu Nicolae Doru , Popa Dinel
Published: October 2014

In this paper we study the motion of a mass acted by a harmonic impulse through the end of a nonlinear cubic spring. The mass moves on a horizontal plan and between the mass and the plan there exists a dry friction of known constant value. The motion is described by nonlinear equation with discontinuities given by signature and Heaviside step functions. We also obtained the stop conditions, when the mass does not move at all. Finally the study is completed by numerical simulation.
Aspects Concerning New Trend in Management Control Systems Design and Implementation Strategy
Authors: Csapo Jozsef Levente , Brisan Cornel
Published: October 2014

This paper provides an overview on Management Control Systems (MCS), a historical review of the different trends in the control systems design and the common characteristics of main trends. MCS developed from closed and formal systems, based on cost and financial control, in complex, fully computerized, open and dynamic systems, which considers the psychosocial and cultural aspects and continuously adapt themselves to the organization’s needs. The performance level of the control system affects the success of the organization. The implementation process of MCSs, in newly acquired entities, follows about the same pattern as its development scheme, starting with the implementation of formal systems of costs and financial control followed by the development/adaptation of specific support systems for industrial areas and completed through the assimilation of the organizational culture. Although the control is one of the most important instruments, meant for achieving the objectives, it has to fulfill the efficiency principle: the costs involved with the control process cannot excess the benefits it will generate. The MCS would be adapted to the specific characteristics of the production unit, but it must retain its formal aspects to not diminish the comparability of the established key performance indicators. The performance level of the acquired entity and sociocultural aspects will determine the integration strategy, which can vary from instantly reform of whole organizational structure and practices till introducing only the performance monitoring system. The goal of the paper is to introduce the Computer Assisted MCS as a new trend in MCS design and to provide a summary of the implementation strategy as part of integration process of newly acquired entities.
Modular Student Learning Kit for Internet of Things
Authors: Pantilimonescu Florin , Hanganu Lucian Constantin , Peptanariu Mihaita , Grigoras Stefan , Ionescu Irina , Potop Georgeta Lidia , Iovan-Dragomir Alina , Hanganu Stela Carmen
Published: October 2014

The term Internet of Things as a component of Future Internet is a recent fast growing global network infrastructure which extends Internet with a sensors and actuators shield. The paper presents a hands-on learning kit based on an open standard embedded computer connected to Internet enabling live data processing. The system uses cloud programming tools to add significant value to the education purpose, by including up-to-date innovative technical approaches and pedagogical values for improving the attractiveness and efficiency of the education activities in the engineering area. The learning goal intends to develop the Internet of things as new universe based on smart objects, connected to the Internet via adequate sensors and actuators. This can be an essential tool for a deeper understanding of the main concepts in physics, informatics and math, even in the early steps of learning. Based on cloud programming resources, the hardware-software components use the latest version of low power 32-bit embedded computer development platform and process interfaces to allow data monitoring, remote physical experiments, mobile world supervising, and collaborative project development. As an open standard learning tool, the kit offers a new computational framework able to serve in scientific experiments and discovery-based learning. This study was strongly motivated by the European Union recommendation to support and enrich the university curriculum by engaging students in hands-on engineering and design activities.
Cultural Influence in Engineering Education, Business and Economics in Terms of Multinational Approach
Authors: Sjolin Jan , Stanciu Tudor
Published: October 2014

With the every ambitious expanding Strategy 2020 of the European Union, to become the most competitive region globally, generates the urgent need to handle multinational (across national) EU and non EU groups in terms of joint training activities. This paper tries to build a bridge between traditional research in terms of national cultures, primarily between the Hofstede and Trompenaars& Hampden-Turner theory buildings and applied methodology. The applied research tackles some first steps in terms of how this traditional research could be applied in education for engineering and business and economics. Thereby showing opportunities to bring a better learning outcome by avoiding cultural "failures" made obvious by this research. The theoretical framework applies into planning phase, delivery phase and follow up phase of the pedagogical cycle.
White Cast Irons with Acoustic Properties
Authors: Girnet Alexandru Ioan , Chicet Daniela Lucia , Axinte Mihai , Stanciu Sergiu , Hopulele Ion
Published: October 2014

There is the opinion, imprinted by tradition, that only bronze alloyed with tin may be used to build bells, musical instruments or sound transmitters, without the need to bring a scientific explanation. Starting from the physical theory and experimental determination that sound travels only through bodies with elastic proprieties, a study over acoustic white cast iron was proposed. After convincing experiments, it results that white cast irons have good properties for producing and transmitting sound waves. The measurements focused two fundamental aspects, the elastic energy available for producing and transmitting sounds and amortization, resulting that white cast irons can substitute with success bronze with tin or even better properties.
Influence of the Degree of Cold Drawing over the Wear Test and XRD Analysis of Pipes Used for Dampers
Authors: Istrate Bogdan , Munteanu Corneliu , Simion Petru , Dia Vasile , Avram Petru , Crimu Carmen Iulia , Earar Kamel
Published: October 2014

Dumpers have studied intensively in the last years and they are the main parts of the suspension system with vertical oscillations role in the absorption of the automobile. The combination of suspension coil with dumper is forming the main body of the suspension system. Dumpers are mainly used for production of automotive industry. The influence of the degree of cold drawing on the mechanical properties of the carbon steel material were studied for the XRD and wear test point of view using microtribometer and diffractometer test machines. The purpose of the work is to observe the main effects of the degree of reduction at different gradations by analysing the X-Ray diffraction – crystallographic determination and scratch test by observing the wear tracks. It was finally measured the loss of material during the wear test, the sample with the highest grade of plastic deformation had the lowest material loss.
Evaluation of Medium-Rise Reinforced Concrete Building Performance under Low Intensity Earthquake Effect
Authors: Ismail Rozaina , Mohd Saman Hamidah , Hassim Masitah
Published: October 2014

The paper presents an evaluation of medium-rise reinforced concrete building in Johor which is subjected to low intensity earthquake effects. Even-though Malaysia is outside the earthquake region, the country had experienced and did suffer from major cases due earthquake in the past like tsunami. Engineers should concern and consider the loading for reinforced concrete building due to earthquake in the building design procedure. The study addresses the performance of critical frame reinforced concrete building when subjected to earthquake motion. The building of Marlborough College Malaysia chooses as model. The building was analyzed using Finite Element Modelling (FEM) using IDARC (2D) with respect to various earthquake intensities obtained from Time History Analysis (THA) data. The yield point at the beam-column connections was analyzed to determine the damage index and damage level of the building subjected to the various earthquake intensities. The building performed the early yielding point at 4.2650 sec for beam element at the intensity of 0.15g. Based on the results, it was found that the critical frame of Condominium Marlborough College Malaysia can stand an earthquake occurrence with intensity up to 0.20g. There is no structural damage some non-structural damage is expected in the non-linear analysis of modal frames. The building was also categorized as the one in the light damage level.
Assessment of Double Hole Contrast Detail Phantom for Image Displacement Evaluation
Authors: Pauzi Nur Farahana , Abdul Majid Zafri Azran , Sapuan Abdul Halim , Che Azemin Mohd Zulfaezal , Junet Laila Kalidah
Published: October 2014

Contrast Detail phantom is used to evaluate the Contrast Detail performance of imaging system. The wall of drilled hole in commercial Contrast Detail phantom will give effect to the penetration of x-ray beam divergence to pass through the base of each hole. This effect will lead to false appearance of image but it does not visualised in the radiograph. In this study, a new design of Contrast Detail phantom’s hole has been developed. The hole feature differs from the current Contrast Detail phantom. The hole consists of combination of different hole's diameters, whereby the small hole diameter (3 mm) is placed on top of large hole diameter of different measurements (5 mm, 7 mm and 10 mm). The thickness of double hole acrylic blocks vary from 10 mm, 15 mm, 20 mm, 25 mm and 30 mm. A tiny size of iron which is used as an indicator was placed at the bottom of each holes. Results shows that, as the value of SID values decrease from 2000 mm, 1800 mm, 1600 mm, 1400 mm, 1200 mm, 1000 mm to 800 mm, the size of upper hole image in different thickness of acrylic block increases from the original size (3mm). In different SID setting, variable acrylic block heights (10 mm, 15 mm, 20 mm, 25 mm and 30 mm) which are located at 100 mm from the center show that, the heighest acrylic block visualises the greatest image displacement. Image displacement which occurs due to magnification can be compensated by increasing the level of SID value and also by reducing the height of acrylic block. The increment in image displacement occurs when the hole is situated far from the center of x-ray beam The new design of hole shows the effect of displacement of object from the x-ray focal length in a well manner.
Decolorization of Reactive Black 5 Using Fe-Areca Nut as a Heterogeneous Fenton Catalyst
Authors: Zaidill Azizan Muhammad Azran , Hassan Hamizura , Faraziehan Senusi , Abu Hassan Norhasnina
Published: October 2014

Decolorization of azo dye, reactive black 5 (RB5) in an aqueous solution was investigated by using Fe-areca nut (Fe-AN) as heterogeneous catalyst. The effect of different parameters such as iron ions loading on supported catalyst, catalyst dosage, solution pH and initial concentration of H2O2on the decolorization efficiency of the process were studied. The Fe-AN was prepared by impregnation process where iron ions were immobilized into areca nut and followed by calcinations process. The best reacting conditions were 4 wt% of iron ions loading on areca nut, catalyst dosage=1.0 g/L, initial pH= 2.5, [H2O2] o = 16 mM at temperature 30°C. Under these conditions, 99% decolorization efficiency of RB5 was achieved within 180 min reaction time. The results indicated that Fe-areca nut has proven to be an excellent heterogeneous catalyst for the decolorization of RB5 solution.