bluuebunny/crossref_metadata_2025 huggingface dataset:
Forming of Microstructure on Hard Brittle Materials in Ductile Mode Cutting
Authors: Kuriyama Kunitaka , Fukuta Masahiko , Sekiya Katsuhiko , Yamada Keiji , Yamane Yasuo
Published: September 2010

The requirement of the ultra-precision machine tools for ductile cutting of hard brittle materials was examined experimentally. One of the essential factors of achieving ductile mode cutting was not only high-resolution feedback control but also the dynamic performance of the machine tool in forming solid immersion lens of monocrystalline silicon. We also proposed newly developed method for ultra-precision machine tools, which does not have enough high dynamic performance in order to achieve ductile mode cutting of the hard brittle materials. An additional device consisted of air slider on the machine tool was applied to cutting of glass in order to keep stable ductile mode cutting. We fabricated high-value added structure, which are designed a diffraction grating, consisted of micro groove on a borosilicate crown glass surface with the developed device.
Improvement in Drilling Performance of Micro Compound Tool
Authors: Ohnishi Osamu , Onikura Hiromichi , Eguchi Toshihiko , Aziz Muhammad , Doi Toshiro K. , Kurokawa Syuhei
Published: September 2010

The present paper deals with the development of micro compound tools and their application to the micro drilling. The micro compound tool consists of a micro drill part and an electroplated part with a nominal finishing diameter of 100 µm and they are fabricated by grinding and electroplating processes. Fabricated tools are used in drilling tests with or without ultrasonic vibration. Influences of drill part geometry on burr formation and influences of diamond grit size on peeling of the electroplating layer are investigated. As the results, secondary cutting edges do not seem to have remarkable ability for reduction of burrs. And large size of diamond grit at the electroplated part of a micro compound tool with a small difference between a diameter of electroplated part and a diameter of drill part seems to be effective in preventing peeling of the electroplating layer and improving drilling performance.
Analysis of Material Properties for the Numerical Simulation of Fatigue Crack Growth under Variable Amplitude Loading
Authors: Aguilar Espinosa Aaron Alejandro , Fellows Neil , Portillo Oscar
Published: September 2010

The numerical simulation of crack closure is employed to assist on the prediction of crack growth rate. Under fatigue load, the stress-strain response of metals is altered due to cyclic loading. For this reason, the material properties characterization is of prime concern as an input parameter to obtain reliable results. From numerical simulations, it was observed that simple material models do not provide accurate data for long crack lengths. In this paper, the effect that different hardening models have on the opening response of a cracked component when it is subject to variable amplitude loading is analyzed. The interaction effects (crack arrest/acceleration) for long crack length simulation are specially highlighted. For this purpose, a 6082-T6 aluminium alloy was analyzed experimentally and numerically in order to measure crack closure, and then, those data were used to predict fatigue crack growth rate under different patterns of overload. The Paris equation and the Elber crack closure concept were employed. The results showed that small variations in the opening stresses obtained from different material models produce high overestimated simulations of crack growth rate. Also, it was proved that the crack closure mechanism is able to take into account interaction effects due to variable amplitude loading.
Very High Cycle Fatigue Analysis of High Strength Steel with Corrosion Pitting
Authors: Perez Mora Ruben , Domínguez Almaraz Gonzalo , Palin-Luc Thierry , Bathias Claude , Arana José Luis
Published: September 2010

This work deals with very high cycle fatigue tests on high strength steel subject to the corrosive action of salt solution. Tests were carried out at constant load ratio R = -1 on corrosion treated and non-treated specimens and sea water flow specimens of R5 steel, which according to an International Classification Society of offshore systems is steel graded with the highest ultimate tensile strength to manufacture mooring chains and accessories intended to position mooring applications such as mooring of mobile offshore units, mooring of floating production units and mooring of offshore loading systems. Fatigue endurance on pre-corroded specimens was quite dispersed but with a mean value of 360 MPa, whereas for the non corroded specimens the fatigue endurance was located between 420 MPa at 105 - 106 cycles, and 380 MPa at 109 cycles. Concerning the sea water flow specimens, important increase in fatigue life is observed in reducing the applied load. Dispersion on fatigue endurance for the pre-corroded and sea water flow specimens was related to the complex process of corrosion on the specimen surface; nevertheless, the resulting pitting holes were associated to fracture origin in these specimens. Furthermore, fatigue failure origin was systematically localized at a circular, elliptical or irregular surface pitting hole formed during the corrosion process; special attention was focused on the pitting holes related to fatigue failure. Finite element results were obtained for the hemispherical voids placed on the specimen surface in order to determine the corresponding stress concentration; these results were associated with the real fracture origin pitting holes observed on specimens with pre-corrosion and sea water flow corrosion. Finally, some conclusions were obtained concerning pitting holes, stress concentration and fatigue life for the pre-corroded and sea water flow corroded specimens.
Self-Affine Crack Pattern in Filter Paper Sheets
Authors: Mora Santos C. Alberto , Rivera Martínez M. del R. , Susarrey Huerta Orlando , Balankin A. , Mendoza Nuñez Maribel
Published: September 2010

In this work the self-affine crack pattern in Filter Paper sheets is studied. This paper has a well-defined anisotropy of mechanical properties associated with visible preferable orientation of fibers in the machine direction. Fracture behavior is in essence brittle, the rupture lines have self-affine invariance, and the stresses ahead of the straight notch follow a power-law behavior. The roughness exponent value is of H = 0.50 0.01, different from the suggested universal value H = 0.8. The classical theory has demonstrated that, in materials such as metal, there is a relationship between the size and the starting crack stress, which does not happen in this material. The tests show that the starting crack stress from stress-strain behavior curves remains stable for the different specimen sizes w and crack length size. Moreover, different types of geometric groove, circular and linear, and without a crack, were tested and show almost the same behavior.
Stress State Localized Analysis on the Tip of the Crack
Authors: Tamayo Meza Pedro A. , Schabes-Retchkiman Pablo S. , Lazo Noguez Alejandra , Yermishkin Viacheslav A.
Published: September 2010

In this paper is presented a study of the analysis of the stress state of micro specimens exposed to a load inside the column of a High Voltage Electron Microscope (HVTEM), in particular for a Mo single crystal. The experimental tangential stresses distribution images were obtained and compared with theoretical calculations using Naiber approach, obtaining an excellent match.
An Experimental Study on the Effect of Aqueous Hypophosphite Pre-Treatment Used on an Aluminium Alloy Substrate before Electroless Nickel Plating
Authors: Szirmai Georgina , Tóth József , Török Tamas I. , Hegman Norbert
Published: September 2010

A new surface pre-treatment procedure has been developed in one of our laboratories [1] for electroless nickel (EN) plating, which appears to be an effective and environmentally benign treatment for the following deposition of a sound and high quality surface nickel coating with good adhesion. For that purpose, the aluminium substrate was immersed in a mildly acidic solution (lactic acid) of sodium hypophosphite in order to modify the passive surface and make it suitable for the reductive chemical precipitation of the nickel-phosphorus nuclei from the electroless nickel plating bath. During this novel pre-treatment technique, the surface adsorption of the hypophosphite anions play an important role therefore several advanced surface testing and analytical techniques (Scanning Electron Microscopy-SEM, Transmission Electron Microscopy-TEM, Energy Dispersive X-ray Spectrometry-EDX, X-ray Photoelectron Spectroscopy-XPS were applied in order to monitor and characterize the surface reactions and adsorption phenomena taking place during the pre-treatment. The Al excited XPS (studying P 2p, O 1s, C 1s, Al 2p, Ni 2p photoelectron lines) proved to be one of the most powerful technique in the identification of the chemical species formed and present on the surfaces examined in this study.
Investigation of Noble Metal Nanoparticles (Ag, Au, Pd, Pt) Produced by Chemical Reduction
Authors: Bajáki Ágnes , Lábár János L. , Csanády Ágnes , Geszti Olga , Hargitai Hajnalka , Karman Franciska H.
Published: September 2010

This work describes atomic-scale, crystalline structure and size distribution for noble
metal nanoparticles produced by water-based, environmental friendly technologies. The process
was developed and implemented to produce noble metal nanoparticles to be used in water filters,
sensors and cosmetics. The particles were investigated by TEM methods and particle size analysis.
Growth process of the crystallites in sols made by chemical reduction in aqueous solutions is
discussed. Comparison with growth models for vacuum deposited thin films is also identified.
Unique Features of Ultrafine-Grained Microstructures in Materials Having Low Stacking Fault Energy
Authors: Gubicza Jenő , Nguyen Quang Chinh , Lábár János L. , Hegedűs Zoltán , Langdon Terence G.
Published: September 2010

The evolution of the microstructure during processing by equal-channel angular pressing
(ECAP) in silver having extremely low stacking fault energy was studied up to 16 passes. It was
shown that at high strains the contribution of twinning to deformation increased at the expense of
dislocation-controlled processes. It was also found that during storage at room temperature (i.e. at
the temperature of ECAP) there was a self-annealing of the severely deformed microstructure after 1
month and its degree was revealed to have a strong dependence on the number of passes.
The Change of the 3D Printing Product Mechanical Properties in the Function of Different Post-Treatment
Authors: Kovács Norbert Krisztián , Kovács József Gábor
Published: September 2010

Rapid prototyping (RP) has changed the method of product design and manufacturing. With the help of RP technologies a physical model can be created within couple of hours from any complex CAD model. RP technologies in contrast with conventional subtractive manufacturing technologies produce the end product by adding material layer-by-layer. 3D printing is one of the most widespread technologies in the industry. Because of the porous structure and bad mechanical properties of the models further post treatment is needed. Post treatment always means infiltration of the models, in case of gypsum and cellulose epoxy resin is mostly used. In our work the effect of post treatment method was examined on the mechanical properties of the pieces. The investigated pieces were prepared with four different setting of a printer.
Nano-Mechanical and Surface Morphological Properties of TiN Coating Produced by PVD on Tool Steel
Authors: Kovács Tünde Anna
Published: September 2010

Thin films are increasingly used to improve the wear resistance of structural materials. The increased number and diversity of thin film coatings applied in industry arises an increased demand for practical and reliable characterization of surface coatings itself. A variety of tribological and mechanical testing procedures have been developed and used to evaluate different aspects of film quality.
This work shows the test results of surface modified HS 6-5-2C tool steel substrates coated by physical vapor deposited (PVD) TiN layer. Two different commercially available PVD technologies were used for producing the test samples. The aim of this work was to analyze and evaluate the correlations between the surface morphology, plasticity, hardness and wear properties (during dry friction) of the coatings. Atomic force microscopy was used for characterizing the roughness of the surfaces, a dry friction ball-cratering test equipment for the wear tests and microhardness tests and nanoindentation for characterize the mechanical properties of the samples produced by different technologies.
Role of the Laser Focus Position in the Laser Beam Cutting of Thin Stainless Steel Sheets
Authors: Meszlényi György , Dobránszky János , Puskás Zolt
Published: September 2010

This paper examines pulsed Nd:YAG laser cutting edge quality of 0,4 mm thin AISI 304L austenitic stainless steel sheets. We analyze the effect of laser beam focal plane distance from the upper plane of the sheet and the effect of cutting speed on the striation of the cutting edge. We obtain the acceptable focus position range from the analysis of percussion drilling. At the evaluation we determine the optimal focus position for the maximal cutting speed.
Electrospinning – A Candidate for Fabrication of Semiconducting Tungsten Oxide Nanofibers
Authors: Nagy Áron Kázmér , Pfeifer Judit , Lukács István Endre , Tóth Attila Lajos , Balázsi Csaba
Published: September 2010

The excellent gas sensing properties of the tungsten oxides have been manifested first of all in nanostructure and 1D, and 2D open structured forms. For optimal performance the sensing layer substrates should be of large specific surface. In this paper we report on electrospinning – a candidate for fabrication of large specific surface tungsten oxide nanofibers. Fibrous tissues doped with tungstic acid hydrate (H2WO4.H2O) and tungsten oxide one third hydrate (WO3.1/3H2O) has been created and characterized by X-ray diffraction, scanning electron microscope and energy dispersive spectroscopy in order to learn about the changes the materials suffer during the process.
Analysis of the Polymer Coatings of Coronary Stents from the Aspect of Drug Absorbing and Eluting
Authors: Robák Beáta , Szabadíts Péter , Bognár Eszter , Puskás Zsolt , Toldy Andrea
Published: September 2010

The rate of restenosis can be decreased by the usage of drug eluting stents compared to
bare metal stents. The aim of this work was the optimization of micro sprayed polymer coatings for
medical applications and the examination of drug absorbing and releasing properties of these
coatings. Control groups were bare metal stent models (316 LVM type austenitic stainless steel tube
slices). Different types of medical grade polyurethane granules were applied onto the stent surface.
Various methods were used for the examination of the surface and coating quality, such as optical
microscopy, scanning electron microscopy and atomic force microscopy.
Dynamic Mechanical Tests on Magnesium Catalyzed Cast Polyamide 6 Composites Having Different Additives
Authors: Andó Mátyás , Kalácska Gábor , Czigány Tibor
Published: September 2010

Due to the effect of graphite and montmorrilonit additives, the impact strenght slightly decreases, but by the influence of softening material, the value of impact strength can be three times more than the pure PA6. It is determined that graphite can be added until 3%, montmorrilonit can be added until 6% and softening material can be added until 15% to the base matrix. These samples give basis for special characteristics examinations.
Magnetic Detection of Creep Deterioration
Authors: Mészáros István
Published: September 2010

In this work a new magnetometer setup and a novel model based data evaluation technique was used to determine the creep damage in ferritic power plant steel. The tested material was 1Cr-0.5Mo-0.25V ferritic steel which is commonly used as pipeline base material of steam generators in power plants. It is commonly accepted that a combined form of fatigue and the creep processes cause the deterioration of this structural parts due to long time elevated temperature service. Nowadays, there is increasing need for remaining lifetime estimation of these engineering structures. In this paper, the variation of magnetization curves of Cr-Mo-V ferritic steel due to creep measured and the relation between creep damage and the magnetic property changes is discussed. A new data evaluation technique is presented which is based on the hyperbolic model of magnetization. A magnetic descriptor was derived from the hyperbolic model which can be determined from the initial part of the normal magnetization curve. The introduced parameter and evaluation technique seems to be especially useful for magnetic nondestuctive remanent lifetime evaluation.
Grain Boundary Engineering of Metals by Thermo-Mechanical Treatment
Authors: Szabó Péter János
Published: September 2010

The relative fraction of the special grain boundaries can be increased by thermo-mechanical treatments. During this work, AISI 304-type austenitic stainless steels were plastically deformed and heat treated under different conditions, and then the grain boundary network, which developed during the treatments was investigated.
Results showed that cyclic application of large cold rolling (30% reduction of thickness) and quick heat treatment at high temperature (800 °C, 2 minutes) gave the best grain boundary network. A possible reason of this behaviour is that grains which did not recrystallize after the first cycle, stored a high elastic energy, which helped the grain boundary motions in the next cycles.
To characterize the developed grain boundary network, different parameters are also suggested in this paper.
Textiles Dynamically Influenced Drapability
Authors: Al-Gaadi Bidour , Halász Marianna , Tamás Péter
Published: September 2010

Many researchers examined the static drapeability of textiles, they found that the textiles with different materials, structures or finishing have different drape characteristic. They analyzed also apart the static measuring the drapeability influenced with dynamical effect. They measured the dynamic drapeability during rotating the textile sample [1]. They found that the form of the draped sample is change from the dynamic effect. The Sylvie 3D Drape Tester developed at BUTE record all the surface of draped textiles with scanning technology, and the evaluating computer system define the usual drapeability parameters, like node number and drape coefficient. We complete the equipment with a tool with which we can examine the drapeability after different exactly defined dynamic effect.
Creation and Use of Continuous Cooling (CC) Transformation Diagrams Based on Measured Data and T-t Elements
Authors: Dudás Zoltán
Published: September 2010

The first part of this document demonstrates the creation and use of continuous cooling (CC) diagrams, which are built up from Temperature-time T-t elements. The second part of the document shows the possibility of the creation of virtual CC diagrams by numerical approximated base transformation diagrams, based on measured data.
Dynamic Model of Rolling Mill’s Electro-Hydraulic Gap Adjustment System
Authors: Kővári Attila
Published: September 2010

Choosing of adequate shape technological parameters together with good chemical
compound is very important to produce steel strip with required cross-section and material quality.
The shaping rate, speed and time have an effect on strip mechanical and geometrical quality. The
rate of shaping force needed for steel strip plastic deformation is determined by the strength of the
steel forming. In rolling mills technology the plastic deformation of the strip is realized at high
plastic strain speed so the dynamic change of shaping force might seriously affects the remaining
stress of the rolled strip. The dynamic control of roll gap and force is realized with help of electrohydraulic
servo actuator – so-called hydraulic capsules – which can adjust the roll gap at great
rolling force dynamically. The quality of stand-mounted hydraulic capsule can greatly affect the
dynamics of rolling, consequently the material quality of the rolling. The main contribution of the
paper is to analyze the rolling dynamic behavior using the hydraulic capsule and rolling mill
mathematical model together to show the changing of dynamic behavior of the system when internal
sealing in hydraulic capsule is inefficient.
Diffusion of Carbon in the Centerline Region of Continuous Cast Slabs
Authors: Réger Mihály , Verő Balázs , Kardos Ibolya , Enikő-Réka Fábián , Kaptay György
Published: September 2010

The paper deals with the stability of centerline inhomogenity of continuously cast slabs and hot rolled products. The centerline segregation is a disadvantageous failure of slabs which can affect the quality properties of the final products. During hot rolling of the slabs the centerline segregation pattern will become thin and stretched and it can also be detected in the middle part of heavy plates and coils. It is a common experience that the centerline segregation of heavy plates can not be easily decreased by post heat treatment. The pattern of the centerline segregation was modeled physically by preparing a sandwich structure of steel plates with different levels of carbon and alloying elements. Homogenization experiments were performed and the samples were examined metallographically. Diffusional calculations proved the governing role of carbon activity which is influenced by the distribution of alloying elements.
Modeling of Distribution of Visible and Non-Visible Graphite Nodules Embedded in the Surface Layer of Ductile Cast Iron
Authors: Réti Tamás , Réger Mihály , Csizmazia Ágnes , Czinege Imre
Published: September 2010

The graphite nodule count and size distribution are important structural parameters in the quantitative characterization of the microstructure of ductile cast irons. In several cases, it is observed that local surface damages (cracks or microchip formations) are generated by the final manufacturing process (superfinishing operation), and these defects are originated basically from the hidden (invisible) graphite nodules located directly below surface. Based on measured data obtained by an image analyzer, a stereological model and a simulation algorithm have been developed to analyse the correspondances between the graphite morphology and the defect formation. This method makes it possible to establish a correlation between the microstructure parameters and the occurrence of local surface defects on ductile cast iron components.
Laser Welding of Steel Plates with Divided Beam
Authors: Kálazi Zoltán , Meiszterics Zoltán , Janó Viktória , Szabados Ottó , Magyar Zsuzsanna , Buza Gábor
Published: September 2010

In the steel-work the rolled coils of low carbon steel plates must be unended before
pickling on the continuous mill. This was solved with butt welded joint by laser beam welding at
ISD DUNAFERR Dunai Vasmő ZRt. The 8 kW light power, near TEM00 mode laser beam’s final
part of optical system is a divided parabolic mirror, which creates two focal spot in the welding
region. In the interest of productivity rising, the rolled bands’ ends have to be welded at the highest
speed as far as possible. The welded seams have to tolerate the repeated bends on the pickling mill
without cracking. The optimum parameters of laser welding technology were determined by
metallography and calculation of energetic efficiency.
Investigation and Application of High Performance Concretes
Authors: Sugár Viktória , Takács Márton , Ovári Vilmos
Published: September 2010

Recent research work of the authors is dealing with preparing, investigation and application of high performance concretes (HPC) produced by the mean of results of modern concrete technology. These special types of concrete have one or more outstanding properties conversely the normal concrete. This article is focusing on the results of the experiments regarding self compacting concrete (SCC). During the investigation, effects of the fine-graded fraction was studied, which is indispensable component of the SCC. The effects of bulk density, consistency, air content, compressive strenght were analysed on fresh and hardened concrete.
Application of Simulators and Simulation Tools for the Functional Design of Mechatronic Systems
Authors: Schramm Dieter , Lalo Wildan , Unterreiner Michael
Published: September 2010

This paper considers the application of simulators or demonstrators in the development of mechatronic products. It is shown at what step of the mechatronic design process a simulator or demonstrator can be used to significantly improve a products quality and thus identify possible errors and provide potential workarounds. Cost reduction is achieved by the use of simulators or demonstrators in the early design stage and less real product tests have to be carried out which also could be hazardous for the test person.
Some AI Based Approaches on Mobile Robots Motion Planning
Authors: Burlacu Adrian , Kloetzer Marius , Panescu Doru
Published: September 2010

This contribution presents some important issues on mobile robots path planning. While it is hard to find a unique architecture for all the applications involving mobile robots, specific approaches can provide suitable solutions. Thus, three distinct structures are discussed, all making use of certain artificial intelligence techniques. They address the use and integration of artificial vision, a planning approach based on temporal logics, and a multi agent scheme. The three methods refer cases of mobile robots evolving in environments where various types of sensorial information can be obtained. Each of the proposed solutions determines advantages when it is used for a certain class of tasks.
3D Control for a Truncated Cone Tentacle Kinematics
Authors: Cojocaru Dorian , Boccolato Giuseppe , Dinulescu Ionut , Predescu Alice , Manta Florin , Dumitru Sorin
Published: September 2010

This paper presents the architecture, simulation, implementation and control problem for a class of continuum manipulators – the truncated cone tentacle arm. Desired shape for a tentacle robot is obtained by bending each of the three serial connected sections of a continuous backbone. Such tentacle arm has a fixed length but it can achieve any position and orientation in 3D space. A tentacle arm prototype was designed and the practical realization is now running. For this prototype we present a finite element model, for simulation purposes, we propose a kinematic model to be used in the control structure, and we conducted a series of tests regarding the structure behavior, using both sensor and artificial vision analysis. In this paper we present the results of our work.
Mobility and Direct Kinematics of Parallel Manipulators RSS Type - 3 Actuators
Authors: Filip Viviana , Antonescu Ovidiu
Published: September 2010

The parallel manipulators are multi-mobile planar or spatial mechanisms with two to six kinematical chains that connect two rigid bodies, generically named platforms. The parallel manipulator is a complex topological structure, having the joints of various types. The most frequently utilized joints are: the mono-mobile kinematical pairs (revolute R or prismatic), the bi-mobile cylindrical pairs C and the tri-mobile spherical pairs S. One of the most important problems in parallel manipulators kinematics is finding the solution of direct kinematics. The paper presents a new way for the calculation of mobility and a new method for the direct kinematics of parallel manipulators RSS type, which are driven by three actuators.
Dynamical Analysis of the 2-Dimensional Tentacle Robot
Authors: Florescu Mihaela , Petrisor Anca , Coman Daniela
Published: September 2010

The paper deals with a special class of robots, namely the hyper-redundant arm with continuum elements. First, the dynamic model of the tentacle arm during the motion toward the imposed position is analyzed. The dynamic model of the tentacle arm with continuum elements in conjunction with the electro-rheological fluid is discussed. Also, numerical simulations of the arm motion to the imposed target are presented.
Trajectory Planning for Mobile Car-Like Robot Navigation in an Extra-Road Environment
Authors: Gall Robert , Tröster Fritz , Mogan Gheorghe Leonte , Luca Razvan
Published: September 2010

This paper presents a novel collision-free trajectory planner for mobile car-like robot navigation in an unknown extra-road environment subject to nonholonomic constraints. The environment is represented by a parking lot with real traffic conditions, this meaning that static and dynamic obstacles are to be taken into consideration. The final goal that must be fulfilled by the system is to find a free parking space for the vehicle and safely make the parking manoeuvre while simultaneously detect and avoid obstacles. The planner relies on the combination of the potential field method, the 3rd degree Bezier curves method and on the newly designed “look ahead trajectory predictions” method. The major advantages of this method are the very short calculation time and a continuous stable behaviour of the trajectory. The results presented demonstrate the capabilities of the proposed method for solving the collision-free path-planning problem.
Kinematic-Dimensional Analysis of Parallel Robot Used for Orientation
Authors: Itul Tiberiu Pavel , Pisla Doina Liana
Published: September 2010

In the paper a very simple parallel robot intended for some celestial orientation applications (satellite dishes, sun trackers, cameras, telescopes etc.) is proposed. After describing the mechanism and its kinematics, the workspace and the presence of the singularities are studied. The dimensional optimization to maximize the workspace is described, taking into account the constraints due to telescopic leg lengths and transmission angles.
Feature Based Mapping Procedure with Application on Simultaneous Localization and Mapping (SLAM)
Authors: Luca Razvan , Tröster Fritz , Gall Robert , Simion Carmen
Published: September 2010

We are presenting a feature based mapping procedure applied on data reduction to the relevant information used for autonomous navigation. The proceeding is based on the evaluation of the environment using a SICK LD laser scanner. We assume that laser scanners have the advantage of producing reliable data with well understood characteristics for map generation. By implementing evolutive algorithms we process data into lines representing edges of the surrounding objects and create a simplified representation of the environment (feature based). Because of the dynamic generation and evolution of the map, during the movement of the autonomous vehicle we are considering of merging and fitting the data by applying a shape correlation. The goal of our project defines the capability of a fully autonomous vehicle to safely drive through the environment until reaching the standard parking lots and complete autonomous parking procedures.
The Palletization of Car Batteries Produced by S.C. ROMBAT S.A, Bistriţa, Romania, Using the Serial Robot TRTR1
Authors: Mic Lavinia Cristina , Ispas Viorel , Horvat Adriana Claudia
Published: September 2010

By using the finite displacements theory, this paper establishes relations of dependency between the initial and the final positions of the car batteries and the geometric and design parameters of the robot. For this, the structural kinematic scheme of the robot was used to apply gradually this theory, from the end-effector to the base of the robot. To utilize the finite displacements theory is necessary to register the two positions of the manipulated object in the same reference system. This thing can be done by using matrix relations which transforms the coordinates of the points from one system to another. These relations, along with specific relations from the finite displacements theory, lead to a matriceal algorithm suitable for computer implementation. The numerical application presented in this paper shows the final position of the car battery on the stock pallet, if the geometric parameters, the design parameters and the initial position of the battery are given.
Aspects Regarding Pneumatic System Simulated Control
Authors: Mîndru Rares Ciprian , Maties Vistrian , Lapusan Ciprian , Cosma Ioan Adrian
Published: September 2010

The paper proposes a large approach to pneumatic systems starting from the mathematical laws, written in the form of differential equations, which govern the operation of pneumatic systems and continuing with the simulation model. The concept of integrated design includes all approaches, needed for an optimal and deep system understanding, such as modeling, simulation and control. Pneumatic actuators have a nonlinear functionality because of air compressibility, the existing frictions and the valves nonlinearities. Because of these, they are used in high speed applications and simple positioning systems. Thus, the mathematical analyses of pneumatic systems have received a special attention. The differential equations were implemented in Matlab Simulink, and the model input represents the voltage on the electromagnetic valve, and the output seen on the "scope" represents the movement of the piston pneumatic axis. Some control algorithms are implemented and applied to the model and seen the basic differences.
Analysis of Jansen Walking Mechanism Using CAD
Authors: Moldovan Florina , Dolga Valer
Published: September 2010

In this article is presented a short classification for walking robots that are based on leg locomotion and the main objectives that walking robots designers must achieve. The leg configuration of the walking robot is essential for obtaining a stable motion. Computer aided design process offers certain advantages for designers who attend to realize competitive products with fewer errors and in a short term. The aim of this article is to present the graphical results of the kinematic analysis of a new type of walking mechanism designed by Dutch physicist and sculptor Theo Jansen using Pro Engineer program and SAM, in order to compare the results.
Aspects Regarding the Configuration of a Functional Node in a Distributed Data Acquisition System, Based on PC/104 Compatible Modules
Authors: Purcaru Ion , Purcaru Dorina
Published: September 2010

This paper presents a practical approach for a distributed data acquisition system organized on several levels, with functions distributed in functional nodes. A field bus allows the communication between all programmable electronic modules for data acquisition (first level) and the process server (second level); the last one is a data processing and monitoring equipment which also represents the process server in a computer network with many clients. The electronic equipment for monitoring and recording analog and digital inputs (i.e. a functional node from the first level of the distributed data acquisition system) is described in detail. This equipment is organized around the PC/104 central unit and performs four main functions: acquisition, configuration, local monitoring and communication. The experimental results, corresponding to the Server application, are also presented and discussed in this paper.
On the Control of Tendon Based Parallel Manipulators
Authors: Sturm Christian , Schramm Dieter
Published: September 2010

Tendon based parallel manipulators are capable of realizing movement of high speed and acceleration. In order to perform tasks that require direct contact with the environment control schemes are needed that adapt both operational space variables and tendon forces. By use of an inverse dynamics approach a motion control scheme in operational space is presented. In redundant systems the forces that act along the tendons can be divided into internal forces, the sum of which is zero, and external forces, that produce the driving force for the endeffector. Based on that property an additional and decoupled force control scheme is presented.
Structural and Constructive Modelling of One-Loop Linkages Applied in Robotics
Authors: Tempea Iosif , Livadariu Adriana
Published: September 2010

This paper, presents first, using Polya’s theorem of enumeration of distinct structures, the number of closed plane five-link kinematics chains. These chains differ among them by the number and the position of revolute and prismatic joints. From these chains, by interchanging the link connected to the frame, may be obtained different mechanisms with 2 degrees of freedom. Forward, it is presented the design with CATIA software of some mechanisms with five elements, with applicability in robotics. These may represent the mechanical structure of some manipulators for graving, inscription and other work. Also, they may be used in the design of a robot arm, with more degrees of freedom such as SCARA robots.
Non-Overshooting Force Control of Series Elastic Actuators
Authors: Tokatli Ozan , Patoglu Volkan
Published: September 2010

Whenever mechanical devices are used to interact with the environment, accurate control of the forces occurring at the interaction surfaces arises as an important challenge. Traditionally, force controlled systems utilize stiff force sensors in the feedback loop to measure and regulate the interaction forces. Series elastic actuation (SEA) is an alternative approach to force control, in which the deflection of a compliant element (orders of magnitude less stiff than a typical force sensor) placed between motor and the environment is controlled to regulate the interaction forces. The use of SEAs for force control is advantageous, since this approach possesses inherent robustness without the need for high-precision force sensors/actuators and allows for the accurate control of the force exerted by the actuator through position control of the deflection of a compliant coupling element. Here, a non-overshooting force controller is proposed to be embedded into the control structure of SEAs. Such controller architecture ensures safe operations of SAEs by making sure that the force applied to the environment are always bounded from above by the reference forces commanded to the controller.
Simulating the Control of a Scara Robot by Means of a 3D Hand Position Sensing System
Authors: Tarca Radu , Moldovan Ovidiu , Szabolcs Csokmai Lehel
Published: September 2010

In this paper is presented a possible method for controlling a robot, in this particular case a SCARA robot by using a capacitive 3D hand positioning system. This system makes possible the control of and for virtual reality prototype with application in augmented reality systems.
Calculation of Forces and Reactions from Kinematical Joints of Double Harmonic Transmission with Wave Generator Dephased with π/2 Used in Industrial Robots Structure
Authors: Vela Daniel Gheorge , Madaras Lucian , Miclosina Calin Octavian , Vela Ion
Published: September 2010

This article presents the determination of relations for calculation of forces and reactions within links and kinematical joints of a double gear harmonic transmission with wave generator dephased with π/2, necessary in dimensioning and verifying calculations of the transmission links.
Modelling and Simulation of a Isoglide T3R1 Parallel Robot
Authors: Verdes Dan , Balan Radu , Koppány Máthé
Published: September 2010

Parallel robots find many applications in human-systems interaction, medical robots, rehabilitation, exoskeletons, to name a few. These applications are characterized by many imperatives, with robust precision and dynamic workspace computation as the two ultimate ones. This paper presents kinematic analysis, workspace, design and control to 3 degrees of freedom (DOF) parallel robots. Parallel robots have received considerable attention from both researchers and manufacturers over the past years because of their potential for high stiffness, low inertia and high speed capability. Therefore, the 3 DOF translation parallel robots provide high potential and good prospects for their practical implementation in human-systems interaction.
Method for Planning Multitasking Robot Application Programs in RAPID
Authors: Brad Stelian , Brad Emilia , Ioanes Cosmin
Published: September 2010

In order to set up well-structured multitasking robot application programs careful planning is required. Robot programming languages (e.g. Karel, RAPID, Melfa, SimPro, etc.) vary from robot to robot constructor. General planning tools used in software development (e.g. UML, IDEF, etc.) require adequate professional skills and a special way of thinking such that robot programmers to apply and adapt them to the specificity of each robot programming language. Customized and intuitive planning tools of robot applications with regard to each particular programming language seem to be preferred by ordinary robot programmers and operators when facing with the development of complex robot tasks. This paper introduces such a tool in relation to the RAPIDTM programming language, specific to ABB robot models. Its effectiveness is revealed in a case study.
Impaired Myocardial Perfusion from Persistent Mammary Side Branches: A Role for Functional Imaging and Embolization
Authors: Firstenberg Michael S. , Guy Gregory , Bush Charles , Raman Subha V.
Published: September 2010

The diagnosis and management of ischemic symptoms in patients after coronary artery bypass surgery can be challenging. It has been hypothesized that persistent branches of the internal mammary artery can divert flow from the left anterior descending artery and cause symptoms. We present a case in which successful coil embolization of a side branch improved flow and clinical symptoms. Side branch embolization might be a useful treatment option and should be considered in the management of symptomatic patients with a patent mammary graft.
Microbial Degradation of Petroleum Hydrocarbon Contaminants: An Overview
Authors: Das Nilanjana , Chandran Preethy
Published: September 2010

One of the major environmental problems today is hydrocarbon contamination resulting from the activities related to the petrochemical industry. Accidental releases of petroleum products are of particular concern in the environment. Hydrocarbon components have been known to belong to the family of carcinogens and neurotoxic organic pollutants. Currently accepted disposal methods of incineration or burial insecure landfills can become prohibitively expensive when amounts of contaminants are large. Mechanical and chemical methods generally used to remove hydrocarbons from contaminated sites have limited effectiveness and can be expensive. Bioremediation is the promising technology for the treatment of these contaminated sites since it is cost-effective and will lead to complete mineralization. Bioremediation functions basically on biodegradation, which may refer to complete mineralization of organic contaminants into carbon dioxide, water, inorganic compounds, and cell protein or transformation of complex organic contaminants to other simpler organic compounds by biological agents like microorganisms. Many indigenous microorganisms in water and soil are capable of degrading hydrocarbon contaminants. This paper presents an updated overview of petroleum hydrocarbon degradation by microorganisms under different ecosystems.
Using the Generic Synteny Browser (GBrowse_syn)
Authors: McKay Sheldon J. , Vergara Ismael A. , Stajich Jason E.
Published: September 2010

Genome Browsers are software that allow the user to view genome annotations in the context of a reference sequence, such as a chromosome, contig, scaffold, etc. The Generic Genome Browser (GBrowse) is an open‐source genome browser package developed as part of the Generic Model Database Project (see UNIT here; Stein et al., 2002). The increasing number of sequenced genomes has led to a corresponding growth in the field of comparative genomics, which requires methods to view and compare multiple genomes. Using the same software framework as GBrowse, the Generic Synteny Browser (GBrowse_syn) allows the comparison of colinear regions of multiple genomes using the familiar GBrowse‐style Web page. Like GBrowse, GBrowse_syn can be configured to display any organism, and is currently the synteny browser used for model organisms such as C. elegans (WormBase; http://www.wormbase.org; see UNIT here) and Arabidopsis (TAIR; http://www.arabidopsis.org; see UNIT here). GBrowse_syn is part of the GBrowse software package and can be downloaded from the Web and run on any Unix‐like operating system, such as Linux, Solaris, or MacOS X. GBrowse_syn is still under active development. This unit will cover installation and configuration as part of the current stable version of GBrowse (v. 1.71). Curr. Protoc. Bioinform. 31:9.12.1‐9.12.25. © 2010 by John Wiley & Sons, Inc.
Using the Velvet de novo Assembler for Short‐Read Sequencing Technologies
Authors: Zerbino Daniel R.
Published: September 2010

The Velvet de novo assembler was designed to build contigs and eventually scaffolds from short‐read sequencing data. This protocol describes how to use Velvet, interpret its output, and tune its parameters for optimal results. It also covers practical issues such as configuration, using the VelvetOptimiser routine, and processing colorspace data. Curr. Protoc. Bioinform. 31:11.5.1‐11.5.12. © 2010 by John Wiley & Sons, Inc.
A Molecular Brush Approach to Enhance Quantum Yield and Suppress Nonspecific Interactions of Conjugated Polyelectrolyte for Targeted Far‐Red/Near‐Infrared Fluorescence Cell Imaging
Authors: Pu Kan‐Yi , Li Kai , Liu Bin
Published: September 2010

A red‐fluorescent conjugated polyelectrolyte (CPE, P2) is grafted with dense poly(ethylene glycol) (PEG) chains via click chemistry and subsequently modified with folic acid to form a molecular brush based cellular probe (P4). P4 self‐assembles into a core–shell nanostructure in aqueous medium with an average size of 130 nm measured by laser light scattering. As compared to P2, P4 possesses not only a substantially higher quantum yield (11%), but also reduced nonspecific interactions with biomolecules in aqueous medium due to the shielding effect of PEG. In conjunction with its high photostability and low cytotoxicity, utilization of P4 as a far‐red/near‐infrared cellular probe allows for effective visualization and discrimination of MCF‐7 cancer cells from NIH‐3T3 normal cells in a high contrast, selective, and nonviral manner. This study thus demonstrates a flexible molecular brush approach to overcome the intrinsic drawbacks of CPEs for advanced bioimaging applications.
Morphologies and mechanical properties of polylactide/thermoplastic polyurethane elastomer blends
Authors: Feng Fei , Ye Lin
Published: September 2010

To explore a potential method for improving the toughness of a polylactide (PLA), we used a thermoplastic polyurethane (TPU) elastomer with a high strength and toughness and biocompatibility to prepare PLA/TPU blends suitable for a wide range of applications of PLA as general‐purpose plastics. The structure and properties of the PLA/TPU blends were studied in terms of the mechanical and morphological properties. The results indicate that an obvious yield and neck formation was observed for the PLA/TPU blends; this indicated the transition of PLA from brittle fracture to ductile fracture. The elongation at break and notched impact strength for the PLA/20 wt %TPU blend reached 350% and 25 KJ/m2, respectively, without an obvious drop in the tensile strength. The blends were partially miscible systems because of the hydrogen bonding between the molecules of PLA and TPU. Spherical particles of TPU dispersed homogeneously in the PLA matrix, and the fracture surface presented much roughness. With increasing TPU content, the blends exhibited increasing tough failure. The J‐integral value of the PLA/TPU blend was much higher than that of the neat PLA; this indicated that the toughened blends had increasing crack initiation resistance and crack propagation resistance. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011