bluuebunny/crossref_metadata_2025 huggingface dataset:
Wear Resistance and XRD Analyses of CMoCuNiCrSiBO Coatings Obtained by Thermal Deposition on OLC45 Substrate
Authors: Avram Petru , Imbrea Marius Stelian , Istrate Bogdan , Strugaru Sorin Iacob , Cucos Iulian , Axinte Catalina , Munteanu Corneliu
Published: October 2014

Idlers are machine elements which are subjected to friction solicitations. The geometry, dimensions and weight can’t be modified that is why we decided to modify the contact surface by coating. We have chosen the steel type OLC 45 and we coated it with CMoCuNiCrSiBO by thermal deposition. The selection of these materials was made after a detailed study of the literature. After we obtained the samples, we subjected them to qualitative analyses SEM and XRD and to Quantitative analysis – wearing – destructive test where we obtained the friction coefficient between two coated surfaces [1]. We made the samples which we have analyzed by X-Ray Diffraction and we obtained the quality of the coating [2]. The results showed that the new material has a better structure than the basic material, and we can estimate a high durability of the machine elements coated. On friction test we have determined friction coefficient value.
Some Considerations Concerning the Differential Scanning Calorimetry of Ultra Tough Plastic Materials
Authors: Nedelcu Dumitru , Lohan Nicoleta Monica , Carausu Constantin , Pruteanu Octavian
Published: October 2014

The Differential Scanning Calorimetry (DSC) it’s an important analysis in research since the 20th century, being used is various fields such as: physics, chemistry, science and materials technology. Its applicability has also extended to other fields, such as nanothermodynamics and bio-thermodynamics. Calorimetry measures the amount of heat absorbed/dissipated by a test sample as compared to a reference value, when the test sample is subjected to a heating and/or cooling cycle. The calorimetric effect may be revealed by the temperature-and/or time-dependent heat flow variation, and its evaluation makes sense when particular heat flow variations, specific to the various transformations accompanying temperature variation, occur. The research described in this paper focuses on the study of calorimetry of ultra tough plastic materials such B4300G4 and B4300G6. The samples were obtained by injection moulding and the planning of the experiments was achieved by means of the Taguchi methodology. The differential scanning calorimetry will show the endothermal and exothermal transformations during which we measured the transformation onset and completion temperatures, as well as the temperature in the middle of the transformation process. Also will be measured the amount of absorbed and dissipated heat, respectively. The DSC diagram showed no temperature-dependent heat flow variation that could suggest a solid state transformation. This paper aims to highlight the behavior of glass transition using DSC analysis, the transformation that occurs during heating of the two polymers obtained using three injection angles: 0o, 45o and 90o.
Simulating the Torque and Angular Speed Distribution within a Heavy Vehicle’s Planetary Gearbox
Authors: Alexa Octavian , Ilie Constantin Ovidiu , Marinescu Marin , Vinturis Valentin , Truta Marian
Published: October 2014

Simulating the real-time working of a system a complex challenge that had been developed lately within almost all fields of activity, of course including mechanical engineering as well. If one wants to reveal the torque and angular speed distribution onto the elements of a planetary gearbox, issuing a virtual model was previously needed. This model should replicate both the physical structure and the real working behavior.The modeled and simulated gearbox is a planetary type one. The power flows along the gearbox throughout three simple planetary mechanisms (sun gear and crown type) by successively locking different components with the aid of some multi-plate clutches (acting as locking clutches or brakes). The simulation of the friction element’s engagement is achieved by introducing a physical signal that replaces the pressure of the hydraulic command system. We mention that the pressure evolution has been previously experimentally determined, in order to model the force that acts on the actuator’s piston that, at its turn, presses the plates.The paper reveals the working cycles of the friction elements as well as the working modes of the planetary sets. It also reveals the time histories of the power flowing throughout the gearbox. The friction elements are modeled considering their three working stages: fully disengaged, partially engaged and fully engaged. The planetary sets are modeled starting from Willis equation for the speed distribution. For the torque distribution we used the energy conservation law as well as the torque balance law.Should be also mentioned that the virtual simulating model took into account the effects of the twisting vibrations, spinning inertia of the mechanical components and shafts’ elasticity.
A New Electric Drive System for a Disc Brake System Used in the Vehicle, Experimental Stand
Authors: Baltagiu Daniel , Gaiginschi Radu , Drosescu Radu , Damian Ioan
Published: October 2014

Papers present a new solution for achieving downforce to a brake disc, using a drive gear and ball screw-nut, which the construction adopted, allows moving ball-screw and making the necessary downforce for breaking. The stand includes downforce creating system required by deceleration, and is equipped with a plurality of sensors to determine the following parameters. Measurement of downforce-ring load cell, displacement in the running drive-pressure transducer, mechanism decoupling travel-differential inductive transducer, electrical motor and gear drive mechanism speed-speed transducer, and electric drive motor torque-lamellar load cell. These transducers allow the control of screw ball to realize the forces that are acting on the brake linings in order to control the speed of the vehicle. Using this construction, brake actuation can get higher quality reactions in brake systems.
Vehicle Dynamics Study under Uncertainty
Authors: Bivol George , Ene George , Radulescu Marian Eduard , Iacob Mihai , Copae Ion
Published: October 2014

In all fields, including here technical field, there will always be uncertainties [1,2]; from a quantity point of view uncertainties are a set of values that we can expect. To offer some examples in vehicle dynamic study there will always be uncertainties regarding weight value, rolling radius, rotational mass coefficient, drag coefficient, aerodynamic coefficient, front surface, transmission efficiency etc. [3]. Throughout the paper we call on operations with values intervals and on differential equations with coefficients that have values within certain intervals. Using the well known differential equation for straight movement, certain parameters are analyzed regarding their influences onto the vehicle dynamic behavior. The theoretical achieved results are than compared with results that are reached through real test runs carried onto a vehicle that has gasoline injection, onboard computer, transducers and other built-in actuators. The data offered by these sensors is collected using a data acquisition system.
Wear Resistance and XRD Analyses of CNiCrSiBO Coatings Obtained by Thermal Deposition on OLC45 Substrate
Authors: Avram Petru , Imbrea Marius Stelian , Istrate Bogdan , Strugaru Sorin Iacob , Cucos Iulian , Axinte Catalina , Munteanu Corneliu
Published: October 2014

In army industry are some of machine elements that are subjected to wear solicitations and must have a high wear resistance. The impact of their damage and also their maintenance costs are very high, that is why we proposed to improve their performances. Researches in surface engineering allow the obtaining of new systems of materials by coating the base material surface with other material having superior properties. In order to improve the machine elements durability, we proposed to obtain a new system of materials by thermal deposition. We have chosen the steel type OLC45 as base material and we coated it with CNiCrSiBO. We made the samples which we have analyzed by X-Ray Diffraction and we obtained the quality of the coating. The results showed that the new material has a better structure than the base material, and we can estimate a high durability of the machine elements coated.
Theoretical and Experimental Researches Regarding the Use of Butanol at Diesel Engine
Authors: Dobre Alexandru , Pana Constantin , Nutu Nikolaos Cristian , Negurescu Niculae , Cernat Alexandru
Published: October 2014

Due to the increasing growth of fuel consumption and also its price, alcohols begin to show a real interest for their use as fuel at compression ignition engines. Tightening the requirements on reducing the level of pollutant emissions and greenhouse effect gases has led to the increasing of research on using alcohols as alternative fuel for diesel engine. Among the primary alcohols, butyl alcohol (butanol) is considered to be of great perspective in its use as fuel in diesel engines, due to its properties close to those of diesel fuel. The overall objective of the paper represents using butanol at an automotive diesel engine in order to reduce BSFC, to reduce engine emissions and replace fossil fuels. This paper presents some aspects of the operation of diesel engine fuelled with blends of diesel fuel and butanol. Results of theoretical and experimental investigations done on a 1.5 L diesel engine fuelled with butanol are presented. At the use of butanol in mixture with diesel fuel in different proportions (10% and 20% butanol vol.), brake specific energetic consumption of the engine was reduced by about 2.5% and respectively 5%, NOx emissions decreased by about 15% and respectively 20%, CO2 emission by about 5% for 20% butanol, at the engine running at full load and maximum torque engine speed. The results of experimental investigations have validated the physical-mathematical model used for the simulation of thermo-gas-dynamics processes from the inside engine cylinder. The paper brings real contributions in the field making available to specialists new information related to the use of butanol at the diesel engines.
Virtual High Speed Diesel Engine – A Simulated Experiment, Part I: Combustion Dynamics
Authors: Gaiginschi Lidia , Agape Iulian , Sachelarie Adrian , Girbaci Mihai Alin
Published: October 2014

The research efforts in the direction of internal combustion engines functional cycle simulation, particularly for small capacity diesel engines, are justified by shortening the path between the new conceptual solution and its effects and also to reduce research costs. There can be adopted new organizational and management solutions for the combustion process after these, for example, confirm at the model level. This paper proposes an unizonal physico-mathematical combustion model in high speed small Diesel engines, based on a Vibe-type law and on the heat transfer through the combustion chamber walls modelated after Woschni. The complexity of the model justifies the name of „virtual engine”. This allows to determine the functional parameters as instantaneous and average values, at any engine operating regime. The simulated experiment takes place in perfectly controlled conditions and leads to good results. There are obtained, during the combustion process, dynamics of parameters concerning the vaporization characteristics, combustion characteristics and combustion kinetics, for any operating regime. The parameters are evolving in a predictable way, being experimentally confirmed.
Virtual High Speed Diesel Engine – A Simulated Experiment, Part II: The Influence of Polytropic Exponent upon Combustion Product Formation
Authors: Gaiginschi Lidia , Agape Iulian , Sachelarie Adrian , Girbaci Mihai Alin
Published: October 2014

The virtual high speed diesel engine developed by the authors focused also on combustion product formation, their prediction being possible based on detailed numerical simulation of the processes that overlap in the combustion chamber. Formation of nitrogen oxides consider extended Zeldovich mechanism and the production of combustion compounds with significant concentrations occurs in the hypothesis of excess air oxidation, being carried out according to Gartner's chemical balance. The heat input is based on distinct thermodynamic evolution characterized by constant polytropic exponents. The volume of the mixture in the combustion chamber was discretized at the level of a control micro volume, with precise initial and boundary conditions. Simulation results in the dependencies of compounds of the combustion gases according to the polytropic exponent, at a random regime. This opens the way for the study of complex influence factors which condition the polytropic exponent, upon the combustion product composition.
Experimental and Theoretical Aspects of Fuelling a Diesel Engine with Liquefied Petroleum Gases
Authors: Nutu Nikolaos Cristian , Pana Constantin , Dobre Alexandru , Negurescu Niculae , Cernat Alexandru
Published: October 2014

The severe legislation regarding pollution from actual time determine us to find new alternative solutions for diesel engine fuelling. This paper objective is the use of LPG as alternative fuel at a diesel engine in the purpose of pollutant emissions level decreasing in general and especially of NOx and smoke emissions. Is difficult to use LPG as single fuel at the diesel engine because it has an high auto ignition endurance (CN = -3). There are many fuelling methods of the diesel engine with LPG, but the authors of this paper used the diesel-gas method for a 1,5 l engine fuelling. The research followed the establishment of the optimal LPG cyclic dose and the diesel engine adjustments for different engine operating regimen. The paper presents results of some theoretical and experimental investigations of the LPG fuelled diesel engine. Three substitute ratios of diesel fuel with LPG were taken into account for full load and 2000 rpm engine speed. Thus, the NOx emissions decreased with 20-28 % for different substitute ratios of diesel fuel with LPG. The smoke emission decreased with 35-47% for same substitute ratios. LPG fuelling represents a very good solution for a cleaner environment.
Evaluation of Mechanical Properties of Polyester Composite with Graphene and Graphite through Three-Point Bending Test
Authors: Bastiurea Marian , Rodeanu Magdalena Silvia , Dima Dumitru , Murarescu Monica , Andrei Gabriel
Published: October 2014

Graphenes have aroused great interest among the scientists lately, due to their special physical properties which are supposed to be transferred to composite materials [1,2,3,6]. Some polymers show low mechanical properties which can be improved by adding various types of materials [9,13]. Using nanoparticles, an enhancement of mechanical, thermal and electrical properties can be obtained, even for small contents of additives [10,11,12,14,15,16]. The evaluation of mechanical properties of polymer composites with graphene can be achieved relying on the three-point bending tests [4]. This work presents a few conclusions resulting from the three points bending tests of the polyester composites with graphene and graphite [7,8].
Researches on the Behavior of the Supporting Structure of Railway Traction Vehicles under the Effect of Shock Dynamic Forces
Authors: Sebesan Ioan , Popa Gabriel , Spiroiu Marius Adrian
Published: October 2014

During circulation the railway vehicle is subjected to the action of dynamic forces under the effect of shocks that appear in the driving system caused by stick slip phenomenon, dynamic forces arising from the rolling process when the wheelset is passing over accidental vertical unevenness of the track and also longitudinal dynamic forces occurring in the case of buffering, respectively those caused by frontal impact (the crash forces). The present paper presents the mechanical and mathematical models which are underlying the evaluation of the magnitude of these forces as well as their effects on the resistance of supporting structure of the vehicle and on traffic safety.
A Theoretical Approach upon the Stiffness of Vehicle Resistance Structure Submitted to an Axial Impact
Authors: Soica Adrian , Tarulescu Stelian , Ispas Nicolae
Published: October 2014

The automotive passive safety has the goal to protect the car occupants, so whatever decelerations transmitted to the occupants are manageable by the interior restraints to fall within the range of human tolerance. The ultimate goal of the safety engineer is to reduce injury to car occupants. The study on how the resistance structure of the vehicle deforms is an ongoing challenge for engineers to find optimized solutions. Various methods for absorbing the force of the impact have been adopted over the years. This paper undertakes an analysis into the amount of energy absorbed in case a tube is subject to axial impact, which stands for the longitudinal struts of a vehicle frame, on which deformation triggers were arranged in two modes.
Experimental Determination of the Cinematic Misfit within the Transmission of a 4x4 Vehicle that Leads to Self-Generated Torque along the Vehicle’s Inter-Axle Driveline
Authors: Truta Marian , Marinescu Marin , Alexa Octavian , Vilau Radu , Vinturis Valentin
Published: October 2014

Present paper aims at revealing a way to determine the cinematic misfit within a 4x4 vehicle’s inter-axle driveline, which is eventually the reason of the self-generated torque occurrence. We used experimental methods to determine the magnitude of the cinematic misfit. Within this frame, we used a vehicle that has a longitudinal (inter-axle) differential and we locked it, actually forcing the longitudinal transmission to work without differentiating the angular speeds on its output shafts. On the other hand, the tire radii were different, inducing the above-mentioned cinematic misfit that we were looking for. We also present the way we fit the transducers on the vehicle’s driveline components to measure the needed parameters. The paper also presents some theoretical considerations regarding the occurrence of the cinematic misfit and its way of generating closed power loops within the vehicle’s transmission.
Self-Generated Torque Induced by the Lockable and Self-Locking Differentials within the 4WD Drivetrain
Authors: Truta Marian , Marinescu Marin , Vilau Radu , Alexa Octavian , Ilie Constantin Ovidiu
Published: October 2014

This work is dealing with the self-generated torque that occurs within a 4WD military special automotive drivetrain. The mathematical model stated in this paper is confirmed by the means of multiple tests developed in real conditions. The tests were developed in order to reveal both transversal and longitudinal self-generated torque within the drivetrain, on different road surfaces. The present paper also introduces some new concepts, such is for instance the insensitive domain of a self-locking (or a progressively locking) differential. With the aid of this concept we can easier deal with the self-generated torque that is due to the increased internal friction of the differential. Moreover, a general, comprehensive theory can be further issued that could classify the self-locking differentials according to their internal friction and their locking coefficient variation.
Straight Section Influence on Thermal and Hydraulic Performances for a Wavy Air Fin in a Compact Heat Exchanger
Authors: Albetel Septimiu , Martian Vlad , Nagi Mihai
Published: October 2014

The air cooled heat exchangers are used on a wide range of automotive, construction, industrial or agriculture applications. As the atmospheric air has the lowest convective heat transfer coefficient it is necessary to use different extended surfaces with different geometries. The need for this type of heat exchanger and the relative limited information in the literature, conducted to a study, done at RAAL S.A. Company in collaboration with University “Politehnica” of Timișoara that focuses on finding the optimum length of the straight section depending on the cooler thickness and wavy fin pitch. In the first step we performed analytical investigations on a multiple number of core thickness dimensions, for 5 mm fin pitch. The optimum length of this straight section is considered the section for which the fins that have the highest area goodness factor (J/f). The above numerical study then was to be confirmed in the second step by real life testing. The scope of this study was to determine a relation that shows the influence of the straight fin section on the thermal and hydraulic performances.
Solid Fuels Behavior Revealed by Thermo-Gravimetric Analysis
Authors: Bica Marin , Sofronie Marius Sorin , Cernaianu Corina
Published: October 2014

Thermogravimetric analysis is also used for the determination of mass composition changes of solid fuels caused by heating processes, coal, and wood or plant debris. Energy characteristics of coal depends on the age of their formation (geological age) and the transformations undergone by organic matter under the influence of geological chemistry (chemical age). Several classification criteria, excluding other problems that may arise in connection with the extraction, preparation and other use than combustion, several classifications have been proposed enabling the sharing of the multitude of solid fuels in groups so that each group members behave similarly during the combustion procedure. Wood and plant debris, combustible wastes, coal, have a heating value depending on their mass composition.
The Analysis of the Temperature Influence on the Processing Precision in Centerless Grinding Machines
Authors: Cernaianu Adrian
Published: October 2014

In this paper it is presented an analysis regarding the influence of temperature from the chipping area, in the machining by centerless grinding with transversal feed. The temperature influences the machining precision, the additional loads of the machine – device – tool – part elastic system and the measurement accuracy. These influences have direct impact on the precision and quality of the machined parts executed using the centerless grinding process.
Wind Potential Analysis in Brasov Built Environment
Authors: Ciobanu Daniela , Saulescu Radu G. , Jaliu Codruta , Climescu Oliver
Published: October 2014

Implementing renewables in the built environment represents a must, considering the target of Nearly Zero Energy Buildings set by the European legal frame, starting with 2020. One specific feature of the built environment is that it additionally imposes constraints, and can distort the renewable energy potential, particularly the wind energy. Therefore, the development of optimized, efficient small wind turbines requires on-site monitoring and, further on, models developed/adjusted according to these. Thus, the main purpose of this study is the analysis of the available wind potential in the built environment – particularly in the Colina Campus of the Transilvania University, in order to implement small wind energy conversion systems. Wind data are collected during one year (2013) from the meteorological station from Brasov - Ghimbav (located 8 km far from Brasov), and from a second weather station, which is mounted on the rooftop of the university building in Brasov city (University hill). The results indicate that the area has a promising wind potential for the implementation in this built environment of small-sized wind turbines, which can start operating from 0.8 m/s and producing electricity from min. 1.8 m/s.
Analysis of the Efficiency of Ventilation Systems in Underground Garages
Authors: Ciocan Vasilică , Verdeș Marina , Popovici Cătălin George , Burlacu Andrei , Balan Marius Costel , Cazacu Ionela
Published: October 2014

Underground garages host machines that run on different fuels and have variable capacity. Exhaust emissions of different intensities are leading to significant accumulation of these gases in certain areas. Ensuring the evacuation and carrying out concentration below the standards is the main objective of special ventilation installations and air flow guidance. The paper makes an analysis of the functioning of these systems in various operating conditions.
A Study Regarding the Unsteady Heat Transfer and Phase Change
Authors: Coman Gelu , Iosifescu Cristian , Damian Valeriu
Published: October 2014

The paper presents the experimental and theoretical study for temperature distribution around the cooling pipes of an ice rink pad. The heat transfer in the skating rink track is nonstationary and phase changing. In case of skating rinks equipped with pipe registers, the temperature field during the ice formation process can’t be modeled by analytical methods. The experimental research was targeted on finding the temperatures in several points of the pad and also details on ice shape and quality around the pipes. The temperatures measured on the skating ring surface using thermocouples is impossible due to the larger diameter of the thermocouple bulb compared with the air-water surfaces thickness. For this reason we used to measure the temperature by thermography method, thus reducing the errors The experimental results were compared against the numerical modeling using finite elements.
Active Pulse Thermography Applied to Defect Detection in Bioceramic Materials
Authors: Dragan Razvan Gabriel , Rosca Ileana Constanta , Monchau Francine , Olteanu Ciprian , Zamfira Sorin Constantin , Baltes Liana
Published: October 2014

The present paper presents a non-destructive technique (NDT) using active pulse infrared thermography with a thermal excitation consisting in two photographic flash laps controlled by a signal generator. For this work we used two bioceramics samples, having the same size, 15, 30 mm diameter and 3, 75 mm thickness. A non-defect sample was used as the basis to demonstrate the temperature differences in the defected zone between the healthy and the defective one. In the second sample was created an internal defect. The main advantage of this method represents its possibility to detect the internal defects in bioceramic materials, the method being more reliable then the microscopic method. Other two advantages of this method are represented bythe rapidity of testing and the maintenance of material properties after the thermal excitation.
Rapid Control Prototyping in the Development of Home Energy Management Systems
Authors: Lapusan Ciprian , Balan Radu , Hancu Olimpiu , Rad Ciprian
Published: October 2014

The article investigates the development of home energy management systems based on real-time control algorithms and online identification. The proposed system optimizes the energy consumption for heating and cooling of a household using model predictive control strategies. The virtual prototype of the energy management system is developed, simulated and optimized using Matlab/Simulink. The simulated system is then implemented using dSpace platform and rapid control prototyping on real-time hardware and tested on a laboratory surrogate system. The system performance is evaluated by comparing the results with the response of classic systems used for heating and cooling in domestic houses. The obtained results confirmed the viability of the proposed solution in home energy management systems.
Numerical Study of Corrugation Amplitude Influence of a Wavy Fin in Overall Performance of a Compact Heat Exchanger
Authors: Martian Vlad , Albetel Septimiu , Nagi Mihai
Published: October 2014

In the past few decades heat exchangers, especially air cooled ones, have become very important equipment in different fields of industry. This led to an active research in finding ways to reduce their overall size and costs. A very important role played in reducing the size of the heat exchanger is the convection capability of air, by being the lowest one, dictates the overall size of the heat exchanger. For this reason we are forced to use extended heat transfer surfaces on the air size. The geometry of such extended surfaces has a high impact on heat and pressure drop performances. The present paper focuses on a study, conducted at RAAL S.A. with the support of University “Politehnica” of Timișoara, to find the influence of the corrugation amplitude of a special kind of extended surface named wavy fin, in the overall performances of a heat exchangers by means of area goodness factor (j/f). Designing and building the different geometries needed in the study will be overkill for the company so we have decided to conduct this study with the help of CFD simulations. In order for this to work we will validate the numerical model with the help of a single experimental test, reducing the time and cost of the entire study. These results are afterwards used to modify the fin’s design to obtain an optimum one.
Production of Electricity in Photovoltaic Systems for Administrative Buildings in Romania, Technical and Economic Analysis
Authors: Popovici Cătălin George , Balan Marius Costel , Verdeș Marina , Ciocan Vasilică , Burlacu Andrei , Tofan Bogdan Andrei
Published: October 2014

One of the effects of technological development of all human societies over the past century is more pronounced increase in energy consumption, but more pronounced dependence on fossil fuel consumption, especially as oil, natural gas and coal.The paper presents a comparative analysis of technical and economic point of view of two systems, the first using the classical system (national electricity grid) and the second using the new unconventional technology with photovoltaic systems for administrative building in rural areas.For correct evaluation of the performance of this systems providing electrical energy requires some assumptions about the consumption of electricity, the solar radiation intensity, the energy cost and the climate zones of the location.
Soot and NOx Modeling
Authors: Sabau Adrian
Published: October 2014

This paper presents an advanced version of the original software developed by the author in order to simulate the combustion in the Diesel engines, focusing on simulate soot and NOx formation. Complex kinetic mechanisms are need for realistic modeling. A model derived by systematic reduction of multi-step chemistry is used. This reduction is based on the partial equilibrium assumption of the considered elementary reactions using the skeletal chemistry for n-decan for ignition, combustion and emissions. Subsequently, predictions of heat release rate, as well as NO and soot emissions are compared with experimental data. However, additional effort is required to enhance the fidelity of NO and soot predictions across a wide range
Considerations on Economic Optimization of the Relationship Insulation - Thermal Energy Sources Insurance for Civil Building
Authors: Şerbănoiu Adrian Alexandru , Teodoriu Gabriel , Serbanoiu Bogdan , Serbanoiu Ion , Verdeș Marina , Balan Marius Costel
Published: October 2014

The major objective of this paper is to optimize the relationship insurance energy source - high thermal insulation of the building envelope analyzed in order to minimize the financial effort incurred by the beneficiary. In this respect, the paper proposes a methodology for analyzing the financial perspective of the relation envelope - equipment that capitalizes renewable energy sources, built on a newer concept - optimal cost.
Methodology for Analysis of Energy Efficiency for Residential Buildings Based on the Optimal Cost
Authors: Şerbănoiu Adrian Alexandru , Teodoriu Gabriel , Serbanoiu Bogdan , Serbanoiu Ion , Verdeș Marina , Balan Marius Costel
Published: October 2014

This paper proposes a methodology for analysis, evaluation and selection of the optimal variant for systems designed to ensure thermal comfort in residential buildings. It identifies as a tool that can analyze in detail the technical and economic point of view, the characteristics of a thermal system (closing elements of a building) and heating equipment, subsequent recovery process of the energy potential of multiple energy resources - can provide in terms of cost optimal the thermal comfort.
Ground Temperature Variation around the Horizontal Collectors of a Heat Pump
Authors: Todoran Tudor Paul , Balan Mugur Ciprian
Published: October 2014

The manuscript presents results of a 3 years experiment concerning the monitoring of temperature variation around a horizontal collector, coupled to a ground – water heat pump. Ground temperature was monitored in 7 (seven) measurement points: 1 (one) in the center of the collector area and 6 (six) at 15 cm, 30 cm and 60 cm of the collector boundary. The data processing methodology, described in the manuscript, allowed corrections, comparison with natural ground temperature variation and calculation of important characteristics of temperature variation in each measurement point. The main obtained results are: minimum, maximum and average temperatures, dates when minimum, maximum and average temperatures were reached, amplitude of temperatures variations and deviations comparing to natural ground temperature variation. The study of temperature field allowed the complete characterization of the ground temperature variation, including spatial and temporal variation. Some practical conclusions of the study are also presented in the manuscript. It was highlighted that due to a correct calculation of the collectors field size and to the presence of snow in each heating season of the 3 (three) years of the experiment, the ground temperature did not decreased below 2°C and the ground temperature recovered uniformly after each non heating season.
Study of Ground – Water Heat Pump Parameters during 3 Years of Operation
Authors: Todoran Tudor Paul , Balan Mugur Ciprian
Published: October 2014

The manuscript presents results of a 3 years experiment, concerning in the monitoring of working parameters of a ground – water heat pump with horizontal collectors. The measured working parameters of the refrigerant circuit are: evaporating pressure, condensing pressure, superheating temperature, discharge temperature, sub cooling temperature. There were also measured the flow rate and the temperatures on the heating circuit of water and on the horizontal collectors circuit with antifreeze. The methodology of data processing, described in the manuscript, allowed calculation of evaporating temperature and condensing temperature, based on measured corresponding pressures. The main obtained results consist in a complete set of working and performance parameters and their variation in 3 years of operation. Details are presented for operating conditions characteristic for different cases: middle of heating season, end of heating season, middle of non-heating season, beginning of heating season. Some practical conclusions of the study are also presented in the manuscript. It was indicated how the outside temperature is influencing the values of working and performance parameters, but mainly on the effective number of running periods.
Influence of Cooling Rate on Metallographic Structure for Gray Iron, in the Case of Modification with a Mechanical Mixture of Al and FeSiCaMg
Authors: Chicet Daniela Lucia , Munteanu Corneliu , Cojocaru-Filipiuc Vasile
Published: October 2014

After the formation of graphite in molten iron starts its dissolution phenomenon in the liquid metal matrix. The inoculants master alloys FeCaSiMg was mechanically mixed with aluminum, a superficial active element that concentrate on metal matrix - inoculant interface, increasing the graphite surface, which dissolves with greater speed in the liquid metal matrix. In the case of smaller cooling rates (parts with great wall thickness) the former compact – spheroidal graphite inclusions significantly reduces its degree of compactness, which results in the decrease of mechanical strength.
Influence of Hydrothermal Treatment on Wheat for Milling
Authors: Cozma Danuta , Tenu Ioan , Zapodeanu Cezara
Published: October 2014

In this paper there are observed some aspects regarding wheat conditioning which has as target phisico-mechanical and structural properties changing, in order to improve the quality of flower obtained by milling. It is presented the research methods which include the use of a milling stand and a hydrothermal treatment device of wheat. The results of the experimental attempts are shown in the tables and graphics and the conclusions obtained are presented at the end of the paper.
Studies and Research Concerning the Displacement of Solid Particle on an Oscillatory Flat Surface
Authors: Moşnegutu Emilian , Nedeff Valentin , Panaite-Lehadus Mirela , Bontaş Ovidiu , Barsan Narcis , Tomozei Claudia , Chiţimus Dana
Published: October 2014

The article shows how the operating parameters of a machine used for the separation of a heterogeneous mixture of solid particles affect particle residence time on the working surface in use, the distance followed, respectively the travel speed. Experimental determinations were performed in the laboratory on a stand which working surface runs an alternative oscillatory motion. In the experimental measurements there have been used real particles, respectively small grain beans. Stand parameters which were considered were the angle of the swing plane surface (5o, 7o and 10o) and the crank speed (91, 240 and 405 rpm). As a result of the analysis it was found that between the functional parameters of the working stand (the distance travelled by the particle oscillating solid surface, the time in which the particle follows the distance used as a reference, the linear velocity of the solid particles on the travelled distance) are closely related.
Researches Concerning the Cutting of Strains Plant with Cutting Devices from Romanian Combine Harvesters
Authors: Nutu Gelu , Baisan Ioan
Published: October 2014

This paper presents the experimental research on plants cutting force for Romanian grain combine harvesters, equipped with knife - finger type cutters. On a laboratory stand, experimental determinations were performed with cutters from SEMA, DROPIA 1110, GLORIA 1120 and GLORIA 1422 combines, for six crops: wheat, triticale, soybean, sunflower, rapeseed and sorghum.We studied the variation of the cutting force depending on the knife speed and the sharpening angle of the cutting edge of the knife, for the same size of stem diameter and humidity, specific for the harvesting period.The experimental data revealed that the necessary force to cut the stems decreases with the knife speed and increases with the sharpening angle.
Losses Analysis of Materials Resulted from Shredding of Food Materials with Soft Texture by Means of Metal Wire Cutting
Authors: Olaru Ciprian , Nedeff Valentin , Panaite-Lehadus Mirela , Olaru Ionel
Published: October 2014

The paper treats the analysis of losses of juice/material resulting from shredding of food materials with soft texture by means of metal wire cutting. For a better relevance of determinations have been chosen different food materials, different diameters of metal wire cutting and different heating temperatures. The objective of this analysis is to identify the correlations that exist between the cutting device and the product obtained after shredding, in order to improve shredding efficiency by reducing the losses of juice / materials resulted from shredding of food materials.
Researches Regarding the Reliability of the Spraying Nozzles Used for Vineyard and Orchard Sprayers
Authors: Tenu Ioan , Rittner Tibor , Rosca Radu , Cozma Danuta
Published: October 2014

The spraying equipments used for pest and disease control have a significant effect over the maintenance technologies in vineyards and orchards. The phytosanitary treatments are efficient if they comply with the following conditions: application in due time; minimum consumption of active substances; uniform distribution of the solution on the surface of the leaves; reduced contamination effect over the environment etc. These requirements can only be achieved by technologically advanced and precise equipments, with high reliability; reliability is required because 12-16 treatments are performed during the vegetation period and because the chemical substances used for pest and disease control are highly corrosive towards the materials used for the hydraulic system of the equipment. The paper presents the results of the tests concerning the reliability of the spraying equipment nozzles; the tests were based on an adequate research method and were performed in a specially designed laboratory. The results showed that there was significant wear of the nozzles’ orifices, leading, in time, to major variations of the flowing rate. A statistical analysis of the experimental data resulted in the deduction of the equations for the flow rate variations as a function of time.
FEM Simulation on Uniaxial Tension of Hyperelastic Elastomers
Authors: Carlescu Vlad , Prisacaru Gheorghe , Olaru Dumitru
Published: October 2014

Modeling large nonlinear elastic deformation of elastomers is an important issue for developing new materials. Particularly, this is very promising for design and performance analysis of dielectric elastomers (DEs). These “smart materials” are capable of responding to an external electric field by displaying significant change in shape and size. In this paper, finite element method (FEM) was used to simulate the mechanical behavior of soft elastomers on uniaxial tension. Experimental data from uniaxial tensile tests were used in order to calibrate hyperelastic constitutive models of the material behavior. The constitutive model parameters were evaluated in ABAQUS/CAE. The 3D-model simulation results of a dumbbell shaped specimen at uniaxial tension shows very good correspondence with experimental data.
The Generation of Conical Gears by a CAD Soft
Authors: Popa Dinel , Stanescu Nicolae Doru
Published: October 2014

In this paper we present the modalities to obtain, by a CAD soft, the solids that materialize the conical gears. The procedure is similar to the industrial ones for the cutting of the teeth of the conical gears and it assumes the existence of the generator tool and a raw material. The algorithm of the method permits the obtaining of any gears, no matter the shape of the tooth, its inclination etc. Finally, we present an application for the obtaining of a gear with two wheels with straight teeth.
An Overview on Assistive Technology Training Courses for Salespersons
Authors: Ciobanu Gabriela , Harja Maria , Ciobanu Octavian
Published: October 2014

Assistive technology is any device or system that increases, maintains or improves the functional capabilities of people with disabilities. There are a lot of national and international Assistive technology training programs aiming to expand the knowledge base of professionals, and introduce newcomers to the disability field. These training programs help participants in understanding the utility and the effects of assistive technology and the possible areas of application. The paper presents the training courses of an educational European project called "Launching of Sector Skills Alliance for Training & Apprenticeship of Health Care and Food Supplements Salespersons" (H-CARE). The H-CARE project uses e-learning technologies to provide training courses and apprenticeship in the area of Health care (Assistive Technology) and food supplements. (H-CARE) was developed by a consortium of partners made of governmental organizations, universities, associations and small enterprises that complement each other in their respective contributions to the project. The graduates will be able to explain the Assistive Technology solutions to meet the needs of disabled people, to identify and select appropriate devices and to evaluate the implementation of Assistive Technology solutions through marketing principles.
New Applications for Mechatronic Platforms in Trans and Interdisciplinary Education
Authors: Cristea Luciana , Zamfira Sorin Constantin , Luculescu Marius
Published: October 2014

Mechatronic platforms ensure the stimulation of the creativity, problem solving ability in working groups and training skills by solving the tasks and challenges in implementing new assimilated knowledge, but also by using their own ideas, collaborating and team working. The main objectives of the study consisted of examining the effects of using mechatronic platforms in educational processes and identifying new ways to use them in order to achieve trans and multidisciplinary technological knowledge and to create the ability to find and implement solutions to the encountered technological problems with the increase of creativity. In this study the focus was on ways of solving technical issues and this performance was achieved by students and teachers from pre-university education in using Mechatronic Platforms. The study was conducted over a period of two years (2012 and 2013) and benefited from the results obtained in the POSDRU 64069 Flexform - flexible training program on mechatronic platforms project. The obtained results lead to the development of new flexible educational applications for Mechatronic Platforms.
Success Elements Analysis of International Engineering and Educational Projects
Authors: Stanciu Tudor , Sjolin Jan , Dragomir Mihai , Stanciu Calin
Published: October 2014

The objective of the paper is to present and compare the results of several international projects and to identify pedagogical and project success elements. The generic projects are few examples that had in common the several objectives: to identify the training needs; to develop an evaluation tool to transform actual and current training offered by corporate /occupational further training institutes ; to improve quality of education to meet the needs of working life. In projects, the training needs were identified involving universities, educational institutions, training and consulting companies from countries across Europe.The selection of the study cases is not random. The intent is to emphasis the consequences-by using similar approach-into distinct project methodologies: one is promoted largely by sponsors from US; the other three are according to the EU rules, regulations, and procedures.
Fire Resistance Performance of Reinforced Concrete Column with Embedded Permanent Formwork Using Woodwool Panel
Authors: Zakiah Ahmad , Nursafarina Ahmad , Rahman Azerai Ali , Hamid Hanizah Abdul , Md Noh Mohammad Soffi
Published: October 2014

This paper reports the investigation on the fire resistance performance of reinforced concrete column with embedded permanent formwork from woodwool board (WWCB). A series of slender column embedded with and without WWCB with cross-sections 200 mm x 200 mm for column without WWCB and 300 mm x 300 mm with embedded 50 mm thick WWCB. The height of the slender column was 2000 mm. The fire resistance test was performed in accordance with BS 476-22:1987 for two (2) hours fire exposure. The fire resistance test for the embedded column with WWCB was classified as “good” in resisting fire and heat transfer.
Loading Capacity of Prestressed Concrete Sleeper under Harmonic Function
Authors: Sharul Nizam I. , Dozier E. , Afidah A.B. , Siti Hawa H. , Mohd Ikmal Fazlan R.
Published: October 2014

A significant increase in demand for services will mean volatility axial load applied to structural elements, particularly the railway station when a train distributions narrow peak intervals. The prestressed concrete runway is one of the major structural component of the train and was showing fatigue cracking as a result of this change. Any local information that link fatigue fracture in concrete directly to understand the fatigue performance are limited. It is important that the load can be simulated real train closed to those under service load. This work aims to study the ability to withstand fatigue loading during services and the flexural behavior of sleeper under low velocity impact loading. The outcome of the work is to produce a harmonic function that will express the variable amplitude waveform through numerical modeling constant amplitude. This is involved a PSC responses due to train wheel loading of the commuter train.