bluuebunny/crossref_metadata_2025 huggingface dataset:
A Convenient and Economical Method for FPGA Data Configuration by MCU
Authors: Tang Xing , Wang Jing
Published: October 2014

In this paper, we provide a convenient and economical method for configuring data into FPGA serial configuration devices by MCU. We develop an active serial configuration scheme and a XModem protocol by MCU. Experiment results show that our approach is simpler and more convenient to be implemented.
The Design of Regional Compensation DVR in Medium Voltage System
Authors: Zhu Zheng Guo , Zhang Hua Ying , Yao Sen Jing , Cao Jun Wei , Yang Jin Tao
Published: October 2014

The design of a Dynamic Voltage Restorer that is suitable for compensating regional voltage sags in 10kV distribution system is introduced in this paper. The design of the main circuit based on cascaded H-bridge, the device for energize DVR and the transformer-less coupled circuit are presented. For the voltage sags in neutral point non-grounded system, a reference voltage calculation method with the aim is to restore the line voltages on the load side is put forward. The simulation model of a substation including the designed DVR device has been built in PSCAD, and the compensation results under different fault types are simulated and analyzed, the influence of the energize device on the distribution system is studied. The simulation results verify the correctness and effectiveness of the design of DVR hardware and the reference voltage calculation method.
Design of a New Type of Vehicle Braking Energy Recycling Device
Authors: Luo Zhong Hui , Xiao Qi Jun , Wu Jun Lan
Published: October 2014

According to the vehicle energy conservation and emissions reduction, it is applied the integrated technology of machinery, single chip microcomputer and hydraulic transmission to design mechatronics device which can be used for urban transit vehicle braking energy recovery. Using hydraulic accumulator as the energy storage and release components, based on embedded microcomputer control technology and electro-hydraulic proportional valve control technology, using sensors to collect vehicle operation condition parameters, through single chip microcomputer intelligent control to make the vehicle has the function of adaptive recovery and release energy when braking and start. The application of this device, with energy conservation and emissions reduction, has the effect of reducing vehicle emissions.
The Adaptive Feedback Control with Dynamic Feed-Forward Compensation of the Giant Magnetostrictive Actuator
Authors: Deng Kai , Yang Bin Tang
Published: October 2014

The giant magnetostrictive actuator (GMA) has been used in more and more areas. But due to the existence of the nonlinear hysteresis, how to realize the high precision drive of the GMA is becoming a key problem. The paper proposes a new control algorithm of the adaptive feedback control with the dynamic feed-forward compensation. Under the expected displacement of sinusoidal signal (1Hz of the frequency and 20μm of the amplitude), the experimental maximum error ratio can reach to 5.15% and mean square error ratio is 2.024%.The paper also gives an experimental comparison with other algorithms.
Study on Optimization for Electric-Mechanic Transmission Parameters
Authors: Yuan Yi , Gai Jiang Tao , Han Zheng Da , Zhang Xin , Wan Fan
Published: October 2014

Based on the optimal design theory, the optimization model for electric-mechanic transmission parameters is established in this paper, and genetic arithmetic is used to solve the optimization model. Comparing the transmission’s performance before optimization with that after optimization, the result shows that the motor design difficulty is reduced and the transmission’s performance is improved after optimaization.
Design and Research of Smart Blades Based on Load Optimization and Power Control
Authors: Cai Pei , Yang Bing Tang
Published: October 2014

Wind energy is the fastest growing source of energy nowadays. The significant growth of size and weight over the past few decades increase the cost of energy (COE) of wind turbines. Optimization of rapid fluctuating loads, which arise from a variety of sources including turbulence, tower shadow, wind shear and yawed flow, can lower the COE. In this article, the “Active Blade”, changing the local airfoil contour driven by a built-in structure to modify the blade’s aerodynamic performance, designed as a solution to reduce fatigue loads on wind turbines. In this approach, aerodynamic load control devices, combined with sensor, controller and actuator, dynamically control the blade loads. The structure is simple with good high frequency fast response performance. The overload stall protection effect is obvious and fast.
Research on the HIL Platform of Photovoltaic Grid Connected System
Authors: Sun Jian Xia , Bi Da Qiang , Ge Bao Ming
Published: October 2014

In order to analysis the characteristics of grid connected photovoltaic system, this paper proposes a Hardware-in-Loop (HIL) real time testing platform based on RT-LAB. The main circuit real time model is built in the RT-LAB, then connect the real time model with a DSP digital controller to achieve the double closed-loop control. And the HIL platform is used to analysis the low voltage ride through (LVRT) technology of grid connected photovoltaic under the of situation power grid fault. The experimental results validate the effectiveness and correctness of the model and the LVRT control strategy.
Keypoint Recognition for 3D Head Model Using Geometry Image
Authors: Feng Lu , Fu Quan , Long Xiang , Wu Zhuang Zhi
Published: October 2014

This paper presents a novel and efficient 3D head model keypoint recognition framework based on the geometry image. Based on conformal mapping and diffusion scale space, our method can utilize the SIFT method to extract and describe the keypoint of 3D head model. We use this framework to identify the keypoint of the human head. The experiments shows the robust and efficiency of our method.
Design and Experimental Test of the Audio Directional System
Authors: Zhang Yang , Su Qiang , Li Hao , Qiu Jie
Published: October 2014

The audio directional system is a new kind of loudspeakers, which can project the audio signal into a specified area as a beam of light. In this paper, the basic principle and system components of the audio directional system are presented. Based “Berktay far-field solution”, the total harmonic distortion of the self-demodulated signals is discussed. In addition, the relative tests are made with the audio directional experimental equipment which is designed. After comparing the theoretical data with the experimental data, point out the disadvantages of self-demodulation theory.
Online GRF: Semi-Automatically Labeling Objects in Video
Authors: Wang Qi , Liu Lei , Wang Jian Ming , Duan Xiao Jie , Li Xiu Yan
Published: October 2014

In this paper, semi-automatic methods based on Gaussian random field (GRF) for online object labeling in video were presented. With a user specified region of interest (ROI), the interested object in all of the frames can be labeled. Two methods, i.e. Updated GRF with fixed SmartLabel (UGFS) method and fixed GRF with fixed SmartLabel (FGFS) method were proposed and compared. Evaluations on object categories have indicated that the UGFS method not only improves the real time performance of object labeling in video, but also has relatively high labeling accuracy.
A Fast Image Reconstruction Algorithm for EIT Based on Wavelet Analysis and LSQR
Authors: Sun Ying Zhi , Wang Jian Ming , Wang Qi
Published: October 2014

The LSQR algorithm is always used to solve the inverse problem of electrical impedance tomography (EIT). However, it always has relatively low reconstruction speed. In this paper, WALSQR (wavelet multi-resolution based Least Square QR-factorization) algorithm is proposed for EIT imaging. With the aid of wavelet transformation, the LSQR solution is obtained in the low-dimension scale space, where important information on the reconstructed image is contained. Hence the computational complexity of reconstruction is reduced without affecting the image quality. In order to verify the effectiveness of the new method, experiments of 2D and 3D EIT imaging are conducted. It lays the foundation for the study of 3D dynamic EIT image reconstruction algorithm.
Research on Mobile Anchor Node Localization Method Based on Hierarchical
Authors: Yuan Hong Li , Lu Jian Yin , Zhang Xiao Ming
Published: October 2014

Localization technology is enabling technology for wireless sensor applications. In order to improve the localization accuracy of wireless sensor network node, this paper proposes a mobile anchor node localization based on a layered approach. First area for wireless sensor networks slicing. Each layer consists of a number of equilateral triangles. Anchor nodes in each layer moves along the edge of the equilateral triangle to locate unknown node. After receiving the position information of the anchor node, unknown node to determine their own position by the triangular positioning.
Flocculation Process for the Treatment of Ballast Water Application Research Process
Authors: Li Xiao Yan , Chen Yang , Liu Sha , Zhou Zhi Min
Published: October 2014

Flocculation process is a method of ballast water treatment process which can satisfy the security, effective, environmental protection, operation and economic request , on the treatment of ballast water has been studied widely at home and abroad .The paper summarizes the flocculation process application treatment about ballast water of ship, introduced the affecting flocculation process factors , and discussed the application prospect of flocculation technology in ballast water treatment application field .
Funny Design Research of Household Products
Authors: Ren Yuan , Zhang Yue , Lu Xuan
Published: October 2014

From the basic concept of product funny design, this paper explored its esthetic concept sources, focused on the feelings of the product experience and the pleasure brought to our lives. It is advocated to concern funny product design when we design household products, and to use new materials and processes, so that the product design is more close to people, and achieve the goal of “Human oriented design”, and then we can feel our product in experience, realized the emotional value of the product.
Fracture Analysis of a Crankshaft Used for Heavy-Duty Truck
Authors: Liu Chang Zhen , Hao Yong Gang , Chen Xiao Fei , Li Xu Dong
Published: October 2014

A failure investigation for a diesel engine crankshaft has been conducted which was used for truck in this paper, which is made from 42CrMo steel. The fracture occurred on the crank web between the 4th crankpin and the 4th journal, the fracture section indicates that fatigue is the dominant mechanism. The dimensions, chemical compositions of material and surface hardness were evaluated in order to find the failure causes. Chemical compositions, the depth of hardness layer and surface hardness are qualified; however, there are transition zone of hardness layer on the journal boss fillet, the dimensions of journal boss is not qualified, it less than specified dimension, and many non-metallic inclusions aggregate zones and heavy segregation were found from metallographic photo, these would reduce the tensile strength. FEA analysis is also used to analysis the strength of this crankshaft, and the results suggest that the dimension of journal boss fillet is the key dimension, which has an important effect on the strength of the crankshaft. So the disqualified machining dimensions, material property are the main reasons for the fraction of this crankshaft.
Tire Longitudinal Mechanics Properties under Various Braking Conditions
Authors: Wu Hai Dong , Guo Kong Hui
Published: October 2014

A dynamical tire model under uneven road is reviewed and the model is adapted to carry out simulation of various braking conditions. The damped characters of the tire at low rotated speed are improved through the study on the system of mass-spring-damper in series. A simple and effective brake model is designed and several extreme braking conditions are simulated. The results of simulation show obvious dynamic properties of the tire at various braking excitation.
ZPA Worms – Definition and Technology
Authors: Pozdirca Alexandru
Published: October 2014

The article presents the definition of a new worm type called ZPA (Pseudo-Archimedes’ Worm), generated with standard cylindrical milling tools on NC lathe. First are showed the enveloping calculus for determining the contact line between the tool and the flank of the worm – considering cylindrical generating surfaces. Knowing the contact line, the axial profile can be determined and implicit the flank of worm. Applying some controlled corrections, this worm type can become a standard worm (ZA – for example). This process is assisted by CAD software, developed by the author. The second part approach ZPA worm’s technology: characteristics of the needed NC lathe, processing steps, tools, cutting conditions. The advantages of the ZPA worm type are: the use of standard tools with reduced costs and also short processing time; the possibilities to cover other standard worms, using the standard cylindrical milling tools and non-specialized NC machining tools.
Virtual Model to Generate Motions on Cyclic Trajectories
Authors: Tataru Mircea Bogdan , Rus Alexandru , Bungau Constantin
Published: October 2014

From the analysis of vibration generating machines, made on the basis of experimental data and virtual models, closed cyclic trajectories had been obtained. In this case the motion is produced using two generators with non-equilibrated masses while the machine body is supported by special rubber elastic elements with fixed mechanical characteristics. In order to increase the domain of operation of such machines and also to improve their functional capabilities the authors propose a new machine structure which uses pneumatic cylinders as actuators but in the same time as supporting elements with controllable mechanical characteristics. A virtual model of this structure had been developed and tested, and the test results are presented together with conclusions on the new structure’s behavior. The virtual model, allows the analysis of mechanical parameters (rigidity) of a pneumatic cylinder in order to establish the controllability of the supporting element. In order to obtain the desired cyclic trajectories the inverse kinematic analysis had been developed, obtaining the displacements at pneumatic cylinder level.
The Influence of the Pinion-Shaft Deflection on the Dynamic Characteristics of Helical Gear Pairs
Authors: Atanasiu Virgil , Oprişan Cezar , Leohchi Dumitru
Published: October 2014

This study presents a dynamic model of helical gears for analyzing the effect of pinion-shaft flexibility on the dynamic behavior of helical gears. In the analysis, the time-varying mesh stiffness is determined in relation with the geometry of the gear pair and incorporates the deflection of the pinion–shaft. A comparison analysis is presented for the dynamic transmission error response of gear pairs supported with a rigid and a flexible shaft system. The results show that the pinion-shaft deflection must be included in the dynamic analysis since they can strongly affect the dynamic characteristics of helical gear pairs.
Optimal Configuration of Fluid Viscoelastic Seismic Dampers on a Ten Stories Building Using Finite Elements Method
Authors: Ionescu Adriana , Negru Mihai , Burada Cristian
Published: October 2014

This paper presents a study made in order to find different optimal configurations of positioning fluid dampers on high buildings for dissipating the seismic energy. The study was made using Finite Elements Method and ANSYS program, on a ten stories building structure. The first step of this optimization process is to consider the fluid dampers having linear damping properties in order to achieve a quicker convergence of the solutions. In order to obtain the influence of the dampers configurations on the structure damping there were made multiple different configurations of dampers positioned on different locations on the building. All these models were analyzed using modal analysis and it was obtained the modal damping of the building structure for the first vibration modes of the structures for each configuration. The graphics obtained can be used for achieving different degrees of seismic energy dissipation for the analyzed building.
A Comparing Tribological Study of PBT and PBT with Aramid Fibers, for Block-on-Ring Dry Regime
Authors: Botan Mihail , Georgescu Constantin , Deleanu Lorena
Published: October 2014

This paper presents a comparative study upon tribological behavior of polybutylene terephthalate (PBT) and a blend of PBT + This paper presents a comparative study upon tribological behavior of polybutylene terephthalate (PBT) and a blend of PBT + 10% aramid fibers, in dry regime. Some of the properties of PBT grade CRASTIN 6130 NC010®. The tested materials they were obtained by molding at ICEFS Savinesti Romania. The aramid fibers added into PBT were supplied by Teijin, and have an average length of 125 mm. Tests were done with the help of a block-on-ring tribotester. The tests parameters were: three normal forces (F = 5 N, F = 15 N and F = 30 N), three values of sliding speed (v = 0.25 m/s, v = 0.50 m/s and v = 0.75 m/s) and a sliding distance of L = 5000 m, in dry regime, each test characterized by (F, v, L) being done twice. The conclusion of this research was that adding short aramid fibers in PBT improves the wear resistance, but slightly increases the friction coefficient. Also, the recorded temperatures near the contact are higher for the blend with aramid fibers. SEM investigation revealed particular processes within superficial layers of polymeric blend.
Assessment of Systems for Carrying out of Planar Biaxial Tensile Test
Authors: Andrusca Liviu , Doroftei Ioan , Barsanescu Paul Doru , Goanta Viorel
Published: October 2014

Determination of materials behavior subjected to complex stress state corresponding to certain operating conditions is one of the main objectives of material testing. Biaxial and triaxial tests are necessary to facilitate understanding of the materials behavior subjected to complex loadings. Stresses applied in biaxial experiments may constitute the stresses that materials experience during their service life. Test devices attached to the universal testing machine are beginning to be increasingly more widespread due primarily to reduced acquisition, operation and maintenance costs and the possibility to be customized according to specific needs required by type of experiments, to the detriment of freestanding machines. Of these, the most representative devices are pantograph type and sliding type, each having advantages and disadvantages. The present study examines two types of mechanisms that are used to test biaxial cruciform specimens in order to evaluate them in terms of achieving the conditions imposed by planar biaxial tensile testing.
Evaluation of Comfort Degree for Pushing/Pulling Motions under the Influence of Controlled Induced Vibrations in the Fingers-Hand–Arm Assembly
Authors: Baritz Mihaela , Cotoros Laura Diana , Balcu Ion
Published: October 2014

Handling different objects, by pulling/pushing motions is influenced by the environment both by its meteorological parameters (temperature, humidity, pressure) and by the operating parameters of the used equipments and devices (vibrations/shocks, noises, intermittent light sources etc.). These influences are materialized by changes in the worker’s comfort degree, by accomplishing the processing accuracy or information acquisition by the human factor. In the first part of the paper some general aspects concerning the influence of vibrations upon the human body are presented, especially for the fingers, hand-arm assembly. In the second part, the methodology and experimental system used for the evaluation of the comfort degree of pulling/pushing motions under the influence of some controlled induced categories of vibrations are described. Following this methodology, the physiological and anatomical limits of motion for each part of the assembly (fingers, hand and arm) are studied, during the pulling/pushing motions and are respectively subjected to a set of controlled induced vibrations. Also these measurements are correlated by computerized methods with the stability degree and posture of the human body. In the final part of the paper we analyze the results and determine the comfort degree for a target group of 10 subjects without malfunctions of the handling system or of the locomotion system.
Techniques, Methods and Instruments for Human Bone Virtual Re-Construction - Main Human Movements Simulations
Authors: Dumitru Violeta Cristina , Popa Dragos Laurentiu , Duță Alina , Ciunel Stefanita
Published: October 2014

To understand the problems, which appear in every human joint, it is very important to know the anatomy and morphology of the human bones and the way in which the components are working together to realize a normal functionality.For this purpose was used a CAD parametric software which permits to define models with a high degree of difficulty. First, it was used a CT or MRI device to obtain the parallel sections in the studied component bone. A 3D scanner can be used only for the outer geometry. In the second step, the images were transferred to a 2D CAD software, as AutoCAD, where the outer and inner contours of the bone were approximate to polygonal lines composed by many segments. After this, the contours were transferred to a 3D CAD software, as SolidWorks, where, step by step, and section by section, was defined the virtual bone component. The primary sections can be directly unified in shapes, as Loft geometrical shape, to define the base of the bone. Additionally to this shape can be attached other Loft, Round or Dome shapes. For some components, as vertebrae, mandible or skull bones, it can be used a preliminary model obtained by parallel sections. Starting from this, the model can be defined using the main 3D curves for final virtual solid model.The virtual model of the bones can be used for different simulations for human movements as walking, flexion, extension, rotation, lateral bending. Also, parts of the entire human bone system were be used for implant, surgery and prosthesis simulation, virtual and rapid prototyping.
Performance Optimization of Blunt-Prosthesis-Rod Complex with Tribological Considerations
Authors: Filep Robert , Arotaritei Dragos , Turnea Marius , Ilea Mihai , Rotariu Mariana
Published: October 2014

The interface blunt-prosthesis from blunt-prosthesis-rod complex is the subject of stress and friction due to forces that act in the walking stage. The dermal wounds and patient's discomfort sensation that can appear can be alleviated or predicted by analyzing the stump’s pressure map taking into account tribological aspects. There are many studied related to transtibial prosthesis but studies that analyze the transfemoral prosthesis are relative rare. A analyze of pressure in blunt-prosthesis complex for transfemoral sub-ischeal prosthesis is proposed during a complete gait cycle.The experiments used three types of liners and a standard type of socket. The areas that are subject of maximum stress and friction are identified as the value of forces of moments that act n stump during a gait cycle. An integral measure and functional ones are proposed to evaluate for influence of each factor that can contribute to optimization of prosthesis and an empirical formulas that connect these measure for prediction is suggested. Theoretical approaches are presented along with experimental results and further research directions.
Modeling and Simulation Keloid Scar Formation from Biphasic Contact Blunt-Prosthesis
Authors: Turnea Marius , Rotariu Mariana , Arotaritei Dragos , Ilea Mihai
Published: October 2014

The definition of the "prosthetic man" system represents the recording, gathering data, identifying problems, formulating hypotheses and decision making for therapeutic interventions processes. The analyzing of this problem has led to the need to study in detail the changes that occur at the interface of the blunt-liner-socket. The mathematic methods of the kinetic theory can be used to develop models described by equations which characterizes the behavior of the particle group based on a description of the microscopically interactions. Interactions that are taken into account are as: conservative interactions that alter the microscopic activity; Proliferation or destruction interactions, the birth or death of a particle; stochastic interactions that modify speed according to a speed leap process. The causes of release and key changes responsible for the formation of a keloid scar remain elusive and there is no satisfactory treatment for this disorder. A current approach in tissue engineering is to use a three-dimensional precursor similar to a tissue of cells called matrix (scaffold) for growth (cell density localized spatially and temporally). We thus propose a mathematical model and its numerical implementation in Matlab, using finite differences, to describe the development and distribution of cells in such arrays. In addition, we propose an algorithm to optimize the model parameters in order to minimize the error occurred between the experimental data and the numerical generated data.
Biomechanical Aspects of the Lower Limb Positions to the Direct Free Kick at Football
Authors: Popescu Lucian , Budescu Emil
Published: October 2014

This paper present the aspects regarding the kinematics analysis of the human lower limb, respectively the angular positions and the angular velocities of the body segment, thigh, leg and foot, during of the direct free kick at football. For the analysis were videotaped the direct free kicks of 10 human subjects, children between 10 and 13 years, after which the images were processed using a specialized software. The method of the direct experimental kinematics analysis it allowed the determination of the amplitudes and the angular speeds segmentation advisable for to obtain accurate kicks in the direct free kicks with the ball. Regarding the performance, the objective pursued was that the ball must to have a trajectory on the space of the gate and also exceed the human wall which it is in front of the gate.
Method and Software for Analyzing the Assembly/Disassembly Operations of Mechanical Products
Authors: Iacob Robert , Popescu Diana
Published: October 2014

Enrolling in the current trends of using collaborative virtual environments and virtual reality techniques for engineering applications, the current paper presents the synthetic results of a research in which an innovative method and software application were developed for analyzing and simulating the Assembly/Disassembly (A/D) operations of mechanical products. Starting from the 3D CAD model of an assembly and using connection interface and mobility operator concepts, the application supports the designers in generating valid A/D plans by determining the interfaces between components, calculating the components mobility and identifying the functional role of components in an assembly. Thus, the developed software provides designers an automated tool for analyzing A/D operations, obtaining and simulating A/D sequences, useful in the design phase of a mechanical product, for training the operators, as well as for improving the productivity of activities such as recycling, maintenance and reusing. Moreover, the application was conceived so that, in a further step, to be integrated in an immersive environment, offering a realistic simulation in two modes of interaction: free mode and kinematically guided. Finally, in order to validate the proposed methods and concepts, the application was tested for evaluating users’ satisfaction degree.
Positioning Systems Actuated by Corrugated Tube Elements
Authors: Jişa Vasile Sergiu , Chetran Beniamin Vasile , Mândru Dan
Published: October 2014

The purpose of this paper is to validate the actuation of the positioning systems with a new type of pneumatic actuators based on corrugated tubular elements. The latter are also called bellows, usually operating as sealing elements or as pressure transducers.The CAD models of two positioning systems actuated with corrugated tube elements are given. The first one, with one degree of freedom, is driven by two bellows disposed in antagonist way, powered with different pressures, offering different displacements and adjustable stiffness. The second positioning system contains two overlapping platforms that can slide on two axis, (having two degrees of fredom), their operation being performed individualy with two pairs of bellows arranged in antagonist way, on two levels, disposed at 900 from each other. Pneumatic diagrams for the two positioning systems are given. Experimental prototypes are developed and the results of the first tests are presented.
Analysis of the Trajectory Shape Described by a Robotic Leg during a Walking Sequence
Authors: Pop Florina , Dolga Valer , Pop Cristian
Published: October 2014

An experimental test bench is proposed in order to analyze the trajectory shape described by the termination of the Jansen’s type of leg mechanism during a walking sequence. A prototype of a walking robot based upon Jansen walking mechanism is constructed for this purpose. A marker is placed at the end of the leg and a CCD camera recorded the trajectory shape described by the leg driven by a DC motor through a crank. The results are interpreted with the help of a program based on image processing created for determining the length and the height of the step during walking after studying the trajectory.
Parameter Identification and Modeling of a Pneumatic Proportional Valve with Applicability in Control Design of Servo-Pneumatic Systems
Authors: Rad Ciprian Radu , Hancu Olimpiu , Maties Vistrian , Lapusan Ciprian
Published: October 2014

The key element in a servo-pneumatic actuation system is the control valve. This paper presents a method for parameter identification and modeling the flow characteristic of a FESTO MPYE-5-1/8-HF-101B proportional valve. An experimental setup and a procedure for parameter identification is presented in the paper. Simulation and experimental results are in agreement and the model of the valve could be used in high-accuracy positioning control design of pneumatic servo-systems.
Evaluation of Loss of Mass due to Corrosion Using Vibration-Based Methods
Authors: Gillich Gilbert Rainer , Praisach Zeno Iosif , Furdui Horea , Ntakpe Jean Louis , Minda Andrea Amalia
Published: October 2014

This paper present a procedure to detect wear or corrosion in structural elements based on frequency changes. Several methods to damage assessment are known, but these are mainly addressed to open cracks without considering the loss of mass. Since the mass decrease is a phenomenon associated with numerous corrosion mechanisms, the idea of this paper was to establish the influence of mass changes upon the natural frequencies of beam and to use it as a baseline in damage detection methods. Consequently, the research was conducted in two steps; first we analyzed the beam dynamics for a segment with reduced volumetric mass density but maintaining the global beam rigidity, succeeding to find the correlation between the frequency changes in the transversal vibration modes and mass loss in form of a mathematical relation. Afterwards, this relation was incorporated in the relation who predicts the frequency decreases due to stiffness diminish, in order to fit it for wear and corrosion assessment. The method’s robustness and reliability was proved by FEM simulations as well as by experiments.
Response Time to Sudden Changes in Speed and Load Regimes for Turbocharged Diesel Engine
Authors: Burciu Salvadore Mugurel , Uzuneanu Kristina
Published: October 2014

The paper includes results from experimental determinations of parameters for turbocharged MB836Db diesel engine, which functioning at dynamic conditions. The studied functioning modes resulting from sudden changes in acceleration and/or loading. The authors used for experimental determinations an railway Diesel engine turbocharged, MB836Db. The results are obtained based on measurements made in the department of Thermal Systems and Environmental Engineering from University “Dunarea de Jos” of Galati. Authors used the equipment which contains PLC module CBM 500, which is put on the turbocharged MB836Db engine. Experimental measurements were performed for dynamic regimes (regimes varying in time) , in case of four changes for engine's acceleration and load.In conditions of acceleration (fast increase of rotation and/or load) only one part of exhaust gasses's energy is transformed in mechanical work for turbocompressor; the rest of the energy is used for the acceleration of different parts which are in rotation movement, to overcome the inertia of the turbocharger with free rotation. That is why, the pressure delivered by the turbocharger in case of functioning on unsteady conditions, at any moment is decreased than the supercharger pressure in steady working conditions, at the same speed and load regimes.The experimental results obtained for unsteady working conditions shows that the performances of engine and turbocompressor are reduced compared to the performances in stationary operating conditions, and this because the turbocompressor inertia is greater than the inertia of the injection system. Because of this issue is modified significantly the combustible mixture quality (decrease in the ratio of air and fuel ), which determines the increase of chemical pollution and decrease of engine performances.The authors presents some conclusions on the influence of the turbocharger’s response on the performances of engine in case of regimes varying in time, such as changes in acceleration and load.
Simulation of the Free Piston’s Movement from the Single Regime Running Thermo-Hydraulic Generator
Authors: Chioreanu Nicolae , Mitran Tudor , Tarulescu Stelian , Beles Horia , Soica Adrian
Published: October 2014

The paper presents the research results regarding the determination of the calculus relations necessary to simulate the free piston’s movement from the single regime thermo-hydraulic generators. The thermo-hydraulic generator is the main part of the single regime running thermal engines (absolute novelty-pioneer invention), that transforms the thermal energy obtained by burning the fuel (gasoline, diesel fuel, unconventional fuels), in hydrostatic energy. The hydrostatic energy produced by the generator is stored in a hydro-pneumatic accumulator. In the paper are presented the variation functions of the forces acting on the piston in one engine cycle and the variation functions of the kinematic parameters (speeds and accelerations). Because the thermo-hydraulic generator is an absolute novelty, the mathematical model for the piston’s movement developed by the authors is an original one, but is based on classical equations that describe the phenomena that take place in the system.
Analyzing the Static Behavior of a Bogie Frame by Comparing Two Methods of Simulations
Authors: Sebesan Ioan , Zakaria Yahia
Published: October 2014

The bogie frame, which is used on LDE 060-DA locomotives, will be the subject of this paper. The method of analyzing its static behavior includes two static structural simulations. The first simulation is performed with SolidWorks while the second one is performed with Ansys. The simulations steps and the related assumptions will be explained in details. Finally the two sets of results gained from both simulations are compared to draw out final conclusions.
Combined Cycle Units – An Alternative to Reciprocating Engines in Terrestrial Propulsion Field - Estimation of Performances
Authors: Balanescu Dan Teodor , Homutescu Vlad Mario , Vasiliu Pavel Doru , Hritcu Constantin Eusebiu
Published: October 2014

Currently, Combined Cycle Power Plants represent the most advanced technology in the domain of high and medium power generation units operating with fossil fuels. Consequently, the interest for their implementation in the propulsion systems field is justified. At this moment, Combined Cycle Units are used for propulsion only on ships (marine propulsion). The present study goes one step further by referring to a small scale Combined Cycle Unit configured for operation as terrestrial propulsion system and based on a two-pressure-levels Steam Cycle. The performances of this unit are analyzed function by the compressor pressure ratio and HRSG feed water temperature.
Experimental Study for Data Validation Regarding the Flow Movement in Natural Convection in an Asymmetrical Heated Vertical Channel
Authors: Burlacu Andrei , Ciocan Vasilică , Verdeș Marina , Popovici Cătălin George , Balan Marius Costel , Tofan Bogdan Andrei , Pastrav Dragos
Published: October 2014

The present paper presents an experimental 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 experimental study was conducted to validate numerical results, in similar conditions. The size variation of the recirculating zone, temperature and speed in the channel were analyzed through the PIV method (Particle Image Velocymetry) using the equipment provided by Dantec Dynamics and the analysis program "Dynamic Studio".
Theoretical and Experimental Research Regarding Operating Conditions of the Refrigeration Absorption/Adsorption Machines Using Solar Energy
Authors: Caciula Bogdan , Panait Tanase , Popa Viorel
Published: October 2014

In this article is presents a short analyze of a solar cooling systems using absorption and adsorption chillers. We try to pick the optimum dimension for the principal equipment of a cooling system for a holiday house place in Mediterranean climate using TRNSYS software.
A Study on Plastic Deformations due to Contact Fatigue Wear on a Cermet Coating Deposited by Thermal Spraying Methods
Authors: Barca Alexandru , Barca Eduard Sebastian , Istrate Bogdan , Crismaru Vasile Ionut , Munteanu Corneliu
Published: October 2014

This study presents the contact fatigue wear behavior of the cermet NiAlSi coating deposited by plasma spraying on alloyed steel. Wear is the failure cause for many component parts of the 4-stroke engine. For example the cylinders are subjected to wear caused by the sliding of the surfaces in EHD lubrication working conditions. Using the AMSLER test machine the rolls have been put to fatigue wear test for 5 hours in conditions of mixed friction. In order to make the results evident one carried out microscopic electronic scavenging analyses using the electronic microscope type QUANTA 200 3D DUAL BEAM.
The Advanced System for Conducting the Electric Furnaces for Heat Treatments
Authors: Cucos Iulian , Munteanu Corneliu , Avram Petru
Published: October 2014

The control of furnaces for heat treatment is a result of the permanent efforts to help work by amplifying of this capacity in solving problems of productions. The advanced system for conducting the furnaces of heat treatments has the main importance in different activities developed in hard conditions. The electric furnaces heat treatment is aimed primarily at obtaining specific temperature profile characteristic type of heat treatment imposed by technology, the heat treatments applied to heat-sensitive parts with complex configuration of alloy or operating in demanding work environments or arrangements often require temperature the furnace is kept constant with maximum deviations of 2 ÷ 3 °C above the prescribed manufacturing technology. Resolving these conditions requires accurate tracking of the desired temperature profile, goal difficult to achieve with conventional control algorithms. In this scientific work will be shown how to solve complex problems of driving an electric furnace heat treatment using the thermo regulators with algorithms type PID (proportional-integral-derivative controller ) and PID-predictive (proportional-integral-derivative - predictive controller)
Finite Difference Approaches for One-Dimension Solid-Liquid Phase Change in Plane and Cylindrical Geometries
Authors: Horbaniuc Bogdan , Dumitrascu Gheorghe , Feidt Michel , Dumencu Andrei
Published: October 2014

Two finite difference methods are presented and discussed, that are applied to the phase change process (freezing) occurring in plane and cylindrical geometries. The first one involves the use of a variable space step grid for each of the time steps of the procedure. An original technique based on Lagrange polynomials is used to determine the actual nodal temperature corresponding to the old temperature field. The second technique uses a fixed grid attached to the phase change material, and the finite difference equations of the nodes neighboring the solid-liquid interface are derived in a special form that involves fractions of the space step. Both techniques are applied to a plane and a cylindrical metallic wall respectively that represents the boundary of the phase change material domain. The numerical results obtained by running the computer codes that we have written for the two techniques show an excellent agreement, the values of the interface rate and of the solid phase fraction at every time step being practically the same.
Study of the Heat Transfer in a Heat Exchanger with Latent Heat Storage
Authors: Luca Constantin , Dragomir-Stanciu Daniel , Crismaru Ionut , Namat Abdul Rahman Jarjes
Published: October 2014

The paper analyzes the possibility of providing heating and hot water for residential buildings using a thermal accumulator that converts solar energy. The accumulator uses the latent thermal energy storage. The phase change material is paraffin wax. The heat transfer inside the thermal accumulator was modeled using Fluent module from Ansys 14.5. The mathematical formulation of the CFD analyses followed the phase change of the wax, the heat transfer inside the accumulator and also the turbulence that occurs in the water pipe. The analysis was done in transient regime to observe the latent heat transfer that goes from the molten paraffin wax to the flowing water.
Estimating Heating and Cooling Degree Days through an Urban Environment Using Publicly Available Sensors
Authors: Papakostas Konstantinos , Martinopoulos Georgios , Tsimpoukis Alexandros
Published: October 2014

In this paper, data from 12 meteorological stations located throughout the greater metropolitan area of Thessaloniki - Greece are used for the calculation of location specific monthly Heating (HDD) and Cooling (CDD) Degree Days utilizing hourly records of the last three years. The HDD are calculated for base temperatures of 15 and 18°C and the CDD for base temperatures of 22 and 24°C by compacting average hourly data. The results show that the HDD average value of the various locations examined in Thessaloniki during the examined period (2010-2013), as compared to the corresponding value for the city center, is increased from 19% up to 48% (depending on the base temperature). The difference in the average value of CDD for the specified time period is more pronounced, as differences range from -10% to -40% compared to the corresponding value for the city center.
Improved Heat Transfer Using Micro-Structures in Trifold Solar Energy Conversion Systems
Authors: Popescu Aristotel , Pfund David , Hernandez-Guerrero Abel , Panaite Ema Carmen , Lupu Ana Georgiana , Stadoleanu Ovidiu Virgil
Published: October 2014

The worldwide renewable energy sources harvesting grew recently at rates of 10–60% annually for many technologies, due to improvements made in all areas. In solar energy conversion, an improvement recently presented in literature is the hybrid system that provides both electricity and thermal energy for domestic applications. For the trifold PV-TE-DHW system, the electrical conversion efficiency is increased by using a thermoelectric (TE) module. This paper proposes the use of micro-channeled heat exchangers at both hot and cold sides of the TE module to improve the heat exchange from the working fluids. The authors developed prior works and published papers in the area of fluid flow and heat transfer in microstructures, heat transfer augmentation, and in solar thermal systems. Results obtained show an improved efficiency energy transfer.
Experimental Investigation of Waste Heat Available for a Hybrid Micro-Cogeneration Group Involving a Diesel Engine Electric Generator and Organic Rankine Cycle
Authors: Prisecaru Tudor , Dobrovicescu Alexandru , Petcu Cristian , Apostol Valentin Gheorghe , Prisecaru Mălina , Popescu Gheorghe , Pop Horaţiu , Ciobanu Cristina , Pop Elena , Stanciu Dorin , Bădescu Viorel , Alexandru Ana , Aboaltabooq Mahdi Hatf Kadhum
Published: October 2014

The paper presents the work developed in the first stage of Research Grant called "Hybrid micro-cogeneration group of high efficiency equipped with an electronically assisted ORC" (acronym GRUCOHYB). The Research Grant is in progress at the Thermal Research Centre, Faculty of Mechanical and Mechatronics Engineering from University Politehnica of Bucharest having as research partner the Rokura Company. The hybrid micro-cogeneration group involves the use of an electric generator based on a 40 kW overcharged Diesel engine and an Organic Rankine Cycle (ORC). The aim of the research is to recover the waste heat available in the exhaust gas and cooling water and transfer it to the ORC in order to convert it into electricity. A description of the experimental setup is given according to the current stage of development. Also the paper presents the experimental results obtained and which show the amount of waste heat available for recovery for different engine operation loads. Based on these experimental results the proper ORC configuration and working fluid can be determined. Several possible ORC configurations suitable for this application are highlighted. Future work and development perspectives are also discussed.
Predict Air Pollution in Brasov City with Regression Models
Authors: Tarulescu Stelian , Beles Horia , Soica Adrian , Chioreanu Nicolae , Mitran Tudor
Published: October 2014

Vehicle transportation is now an important part of our civilization and as it happened with much other technological advancement, the negative aspects are becoming more and more pronounced. One of them is air pollution from vehicles exhaust gases. This pollution has many adverse effects, whose manifestation and character varies depending on the geographical scale in consideration. The relative contribution of different combustion sources is a function of economic, social and technological factors, but all mixtures contain certain primary gaseous pollutants, such as volatile organic compounds (VOC), nitrogen oxides (NOx) and carbon monoxide (CO), that are emitted directly from combustion sources, as well as secondary pollutants, such as ozone (O3), that are formed in the atmosphere from directly emitted pollutants. The elevated concentrations generally occur with in a few hundred meters of the road, although his distance may vary depending on traffic patterns, environmental conditions, and the presence of near roadway urban structures. For the realized study it was choose a route from the historical centre of the Brasov City. In this study is presented the methodology for a prediction model for urban air pollution.