bluuebunny/crossref_metadata_2025 huggingface dataset:
Analyse compréhensive de l'activité de navigation d'orienteurs débutants en fonction des caractéristiques de deux tâches de course d'orientation
Authors: Mottet Martin , Saury Jacques
Published: September 2014

Cette étude visait à comparer et comprendre l’activité de navigation d’orienteurs impliqués dans deux tâches d’apprentissage en course d’orientation afin de proposer des dispositifs d’aide à l’enseignement de l’activité. Cette étude a été conduite en référence au programme de recherche du « cours d’action » (Theureau, 2006). Huit étudiants débutants se sont portés volontaires pour participer à l’étude. Deux types de données ont été recueillis : (a) des enregistrements audiovisuels obtenus grâce à des « lunettes-caméra » équipant chaque participant, (b) des données de verbalisation obtenues lors d’entretiens d’autoconfrontation. Le traitement qualitatif des données a consisté à reconstruire les cours d’expérience des participants conformément à la méthode d’analyse sémiologique issue du cours d’action. Une analyse complémentaire statistique a permis de relever des occurrences en matière de lecture de carte entre les deux tâches. Les résultats pointent des formes d’activité de navigation similaires et différentes entre les deux tâches, en relation avec des phases particulières des parcours, la difficulté et la contrainte temporelle, accordant plus ou moins d’importance à la carte et au terrain d’un côté, et à la balise de l’autre. Ces formes différentes sont discutées en relation avec les contraintes significatives de l’environnement pour les orienteurs et leur utilisation d’heuristiques. Des propositions sont présentées afin d’améliorer l’enseignement et l’apprentissage en course d’orientation.
Moi pour tous, tout pour moi : Les effets de la professionnalisation des responsables d'associations socio-sportives de quartier
Authors: Crosnier Tristan
Published: September 2014

Suite à des émeutes urbaines fortement médiatisées, de nombreuses associations sportives aux visées citoyennes et éducatives se sont développées en France dans les années 1980. Ces associations, dont les bienfaits sont fréquemment vantés aux plans local et national, rencontrent cependant des difficultés à mobiliser des bénévoles et obtenir des financements dans la durée, et limitent leurs actions dans le temps. Nous avons conduit une enquête ethnographique dans une de ces associations de la banlieue nantaise afin de mettre au jour leurs modes de fonctionnement. La description du parcours et de l’engagement du responsable de cette association montre que celui-ci agit autant pour assurer son propre avenir que celui des jeunes qu’il encadre. Sa position précaire sur le plan professionnel l’amène à agir de manière à assurer la pérennité de l’association dans laquelle il travaille et à se rendre indispensable pour son fonctionnement. Il s’agit d’accroître la reconnaissance de la légitimité de l’association en développant ses activités afin de capter de nouvelles subventions. Ceci s’accompagne d’une concurrence, plus ou moins avouée et reconnue, entre les différentes associations d’un même quartier pouvant être néfaste à l’atteinte des objectifs affichés par ces associations.
Modèles ajustés et acquisition d'une acrobatie en gymnastique sportive : efficacité comparée de l'Imitation Modélisation Interactive et du Coping Modèle
Authors: Martin Liza , Lafont Lucile
Published: September 2014

Cette étude examine l’efficacité, auprès de débutantes, de deux procédures ajustées de modélisation, à savoir l’imitation modélisation interactive (IMI) d’une part, et les « coping modèles » (CM) d’autre part, pour l’apprentissage d’une habileté gymnique. La première fait intervenir un sujet expert ajustant son intervention aux besoins immédiats du tutoré, la seconde met en jeu un modèle dont la performance dans la tâche et les états affectifs l’accompagnant, initialement faibles, s’améliorent au fil des essais. Le cadre théorique support est celui de la psychologie sociale du développement et des acquisitions. Trente-six participantes, élèves filles de sixième, ont été affectées au hasard, par groupes de douze à trois conditions d’apprentissage pour l’acquisition de l’Appui Tendu Renversé (ATR) sur la poutre : un groupe a travaillé avec un modèle IMI, un autre avec un CM et le dernier avec un modèle classique non ajusté dit « modèle de maîtrise » (MM). Les effets ont été mesurés sur deux variables, soit le niveau d’habileté pour l’ATR et le sentiment d’efficacité personnelle. Notre démarche empirique interroge la pertinence des formes interactionnelles d’apprentissage et de tutelle réalisées par les pairs, auprès de jeunes élèves. Les résultats mettent en évidence la supériorité des deux guidages ajustés par rapport à la modélisation classique, tant sur l’amélioration motrice que sur le renforcement du sentiment d’efficacité personnelle (SEP). Les données recueillies à l’issue de cette expérimentation révèlent la pertinence des « coping modèles » pour une tâche gymnique. Ces derniers semblent particulièrement efficaces dans le cas d’une tâche acrobatique nouvelle potentiellement anxiogène.
Les cadres sexués du travail émotionnel dans la relation thérapeutique en physiothérapie
Authors: Martin Hélène , Perrin Céline , Damidot Pascale
Published: September 2014

Cet article se base sur une recherche menée par entretiens qui a étudié, dans une perspective de genre, des expériences professionnelles dans lesquelles une(e) physiothérapeute juge que la sexualité menace ou perturbe le cadre thérapeutique, et les stratégies adoptées en conséquence pour préserver ou rétablir ce cadre. Pour analyser ces situations, les auteures mobilisent et revisitent l’approche des défaillances ordinaires (ambiguïté et erreur de cadrage) de Goffman (1991). Elles montrent que les défaillances de cadre étudiées sont sexuées : les attentes et les appréciations face aux risques encourus par les physiothérapeutes, de même que leurs conséquences en termes de stratégies d’évitement sont différenciées en fonction de leur appartenance sociale de sexe.
Le travailler des scientifiques : contradictions de l'engagement de la subjectivité dans le travail
Authors: Guyon Marc
Published: September 2014

Cet article rend compte du travail des chercheurs scientifiques du secteur public de la recherche à travers les contradictions qui naissent de la confrontation entre la nécessité d’engager sa subjectivité dans le travail et la nécessité d’objectiver pour produire des connaissances socialement nouvelles. Le matériau empirique s’appuie principalement sur une intervention en psychodynamique du travail dans le secteur public de la recherche. Après avoir discuté certaines des incidences des dispositifs organisationnels, le panorama des défenses psychologiques observées est décrit. Enfin, l’objectivisme défensif qui semble condenser une part significative de ces stratégies défensives observées sera analysé et discuté du point de vue des chercheurs, de leur subjectivité et de leurs défenses contre la souffrance, et du point de vue de la production de la connaissance.
Conversion of Biomass-Derived Oxygen-Containing Intermediates into Chemical Raw Materials with Zeolite
Authors: Goshima Takashi , Ikeda Keisuke , Fukudome Kenta , Mizuta Kei , Mitsuyoshi Shuji , Tsutsui Toshio
Published: September 2014

To establish a new production route of biomass-derived BTX and propylene, the catalytic conversion of oxygen-containing intermediates which are furfural, levulinic acid, acetic acid or butyric acid, obtained by hydrothermal reactions of bagasse or fermentation of molasses was investigated with zeolites, ZSM-5, SAPO-11 and SAPO-34. Levulinic acid and acetic acid were suitable for generating BTX with ZSM-5. On the other hand, the butyric acid was valuable for converting to chemical raw materials with ZSM-5. By using SAPO-11 as the catalyst, butyric acid converted to propylene at high yields. The yield for propylene was the maximum value 58.8C% at 723K, especially the ratio of propylene to gaseous hydrocarbon products increased up to 90.4C%.
Effects of Ionic Liquid Blending in Polymeric Membrane: Physical Properties and Performance Evaluation
Authors: Mohshim Dzeti Farhah , Mukhtar Hilmi , Man Zakaria
Published: September 2014

— Polymeric membranes have been extensively used in membrane gas separation process. Nowadays, peoples are modifying the membrane by many ways like coating with ionic liquids to further enhance the membrane separation performance. In this project, ionic liquid modified polymeric membranes (ILMPM) have been successfully developed by blending the ionic liquids with the polymer via solvent evaporation method. The ionic liquid used was 1-ethyl-3-methylimidazolium bis (trifluoromethylsulfonyl) imide, ([emim][Tf2N]) and for comparison purpose, the compositions were varied at 10 and 20 wt/wt%. In general, the blending of [emim][Tf2N] and PES has produced dense membrane with miscible mixture without any phase separation. It was observed that, the CO2 permeance of ILMPM has been improved about 271% as compared to the pure PES membrane. However, the CO2 permeance decreased with increasing operating pressure, yet the ILMPM CO2 permeance still higher than CO2 permeance of pure PES membrane. In addition, the CO2/CH4 separation performance has greatly increased about 162% as the IL composition is increased. This initial study has proven that IL helps to enhance of CO2 permeation and improve selectivity.
Methylene Blue Removal from Aqueous Solution by Hylocereus undatus (Dragon Fruit) Foliage
Authors: Abidin Zurina Zainal , Zahra Haddadian , Shavandi M.A. , Shah Ismail Mohd Halim , Ahmadun Fakhru'l-Razi
Published: September 2014

Dragon fruit foliage in its natural form was applied for decolorization of methyleneblue,a cationic dye from aqueous solution. The effects of major parameters like initial dye concentration, pH, adsorbent dose, temperature and contact time were investigated in batch experimental set-up. The optimum values for removal of methylene blue were identified to be pH 9.0 with 30 hours contact time using 1.2 g L−1biosorbent dosage at 250mg L−1 initial dye concentration. The present results suggested that foliage of dragon fruit can be a potential agricultural byproduct to be used as an environmental friendly and low cost biosorbent.
Effect of Modified MIL-53 with Multi-Wall Carbon Nanotubes and Nanofibers on CO2 Adsorption
Authors: Ullah Sami , Shariff Azmi Mohamad , Bustam Mohammad Azmi , Elkhalifah Ali E.I. , Murshid Ghulam , Riaz Nadia , Shimekit Biruh
Published: September 2014

There is a growing need of counter assessing the increase of releases greenhouse gases such as carbon dioxide by researching an alternative technology that can help to reduce carbon dioxide content in atmosphere. This research work investigates the potential of MIL-53 as CO2 capture and storage candidate by conducting an experiment with different pressure between the synthesised and modified MIL-53. To investigate the effect of the Multi-wall carbon nanotubes (MWCNTs) and carbon nanofibers (CNFs) in MIL-53 towards CO2 adsorption performance. The synthesised samples were characterized by Fourier Transform Spectroscopy (FTIR) and Brunauer, Emmett and Teller (BET) techniques. A significant change is observed in the region of the aromatic deformation vibrations due to the different substitution patterns of the aromatic ring. BET surface area for MWCNT@MIL-53 is higher than CNF@MIL-53 and MIL-53. MWCNTs showed the adsorption of CO2 uptake is 0.3mmole-1/g at 100Kpa.
Effect of Purging Rate on the Calibration of Dew Point Sensor and the Estimation of Measurement Uncertainty
Authors: Bae Yun Kyung , Hyun Dong Hoon
Published: September 2014

The purpose of this paper is to study the effect of purging rate on calibration or test of the dew point sensors and estimation of measurement uncertainty. The measurement is carried out to analyze the variation on measured dew point temperatures for the sample dew point sensors (DPS) due to various durations of purge by using calibrated standard chilled mirror hygrometer. To set up measurement condition, the whole measurement system were kept in the state of purging for 3 hours, 15 hours, 65 hours, 140 hours, 200 hours. The dew point temperatures were measured in the range from-50 °C to 10 °C. In order to investigate the effect of purging rate as an uncertainty source on the measurement uncertainty, the contributions to the standard uncertainty for purging rate were also estimated due to reference dew point temperatures. The measurement was conducted according to standard calibration procedure of Korea Testing Laboratory which assures suitability and traceable results. It is also based on international standards.
EOR (Oil Recovery Enhancement) Technology Using Shock Wave in the Fluid
Authors: Petrichenko Mikhail , Vatin Nikolay , Nemova Darya , Kharkov Nikita , Staritcyna Anastasiia Andreevna
Published: September 2014

In this research the alternative method is presented increases of oil recovery of an oil collector. Shock wave impact on layer. The technology is developed, advantage of this method is shown in comparison with layer hydraulic fracturing. For increase oil recovery and restoration of wells the traditional is widely applied technology of hydraulic fracturing of layer (flyuding), allowing on the short period to recover a well. Sense of a flyuding that hydrostatic pressure is created is considerable exceeding mountain and bringing to a rupture of a collector on one or several cracks. In this work the alternative technique of increase in oil recovery is offered by creation of a shock wave small intensity in the bottom fluid. With a high frequency of repeatability set of blows increases quantity of micro cracks in collector rock, increasing coefficient of permeability of layer without breaking its connectivity.
A Guide Cane System for Assisting the Blind in Travelling in Outdoor Environments
Authors: Fan Ming Yu , Bao Jia Tong , Tang Hong Ru
Published: September 2014

In order to help the blind and the visual impaired people to travel outdoor safely, a guide cane system is designed in this paper. It comprises the thin cane as well as the rich remote workstation. When travelling in outdoor environments, the blind could easily set a destination via the voice recognition interface. Meanwhile, the goal and current locations are transmitted to the remote center in real time by using GPS and GPRS modules. After planning a navigation path globally, the route information is downloaded to the guide cane. All guiding information can be expressed to the blind in both auditory and tactile modes. In addition, an RGB-D camera is used to capture dynamic visual environmental information which is uploaded to the remote center for further processing, while ultrasonic sensors are employed to help avoid obstacles around. Testing results show that the system is simple to operation, and has a good usability and reliability.
Study on the Process of 3D Gesture Recognition Technology Based on Computer Vision
Authors: Zhuang Guang Li , Tang Jia Lin , Chen Shu Fen , Li Xi Ying , Su Bin Hua
Published: September 2014

This paper presents a 3D gesture recognition technology based on machine vision as the center. Based on a large number of experiments, this paper sums up and introduces the existing gesture recognition technology, the key research contents of gesture recognition, as well as the history of development of gesture recognition technology. Then, the paper does research in the main technology of gesture recognition .The experimental results show that the method can realize 3D gesture recognition in video sequences with real-time and stability, even more; it can get better recognition result.
Application of Gevers-Wouters Algorithm to Intelligent Dew Point Measurer Control Scheme
Authors: Zhang Guo Sheng , Xu Yan
Published: September 2014

The dew point detection often occur in the industrial field, and control schemes of intelligent dew point measurer directly influence its detecting precision and response time. The sensing signal of dew layer thickness is used as the control object directly in previous control schemes. When the control object is stable and reach the set value, the temperature signal is detected and be used as the dew point temperature. Control effects of above schemes are not ideal because they ignore the radioactive statistical fluctuation. The more effective control law of intelligent dew point measurer is presented by introducing the real signal of dew layer thickness and using Gevers-Wouters algorithm to estimate it. It can make the control process more accurate and improve the detecting precision and response speed of intelligent dew point measurer. It is suitable for real time applications.
Multi-Plate Shift Clutch Morbidity Index Forecasting Method Study
Authors: Chen Man , Ma Biao
Published: September 2014

According to the configuration characteristic of high-power transmissions and working principle of multi-plate shift clutch, the clutch dragging process is analyzed at first in this paper. After introducing the usual monitoring method of clutch dragging process, a portable vibration monitoring method is proposed. And then a GMDH forecast method on the basis of the morbidity index is presented. The practical application of the method can reduce the probability of clutch invalidation, and significantly extend the clutch’s working life.
Coordination and Robust Tuning PSS for Power Systems Using Multiobjective New Hybridation Technic
Authors: Choucha Abdelghani , Chaib L. , Arif S. , Mokrani L.
Published: September 2014

Power system stabilizers (PSS) are usually used in power system plants to damp out power system oscillations. In this paper, coordinated and robust tuning procedures by Hybridization technique are used. This hybridization is based on multiobjective functions using stochastic (GA) methods and deterministic methods (gradient) and even between themselves stochastic methods (GA-SA). To validate the effectiveness of this tuning approach in enhancing the stability of power systems, modal analysis and nonlinear simulations have been carried out on a multimachine power system.
Research on the Utilization of Exhaust Gas Heat for Boilers
Authors: Zhang Hui Bin , Li Bin , Jia Ya Qing
Published: September 2014

The exhaust heat loss of the power plant boiler can account for more half of the boiler heat loss, exhaust gas temperature is 110~160 °Ccommonly, so the exhaust gas heat can be used to reduce the coal consumption, raise the economic benefits. Before and after the desulfurization tower of a 350 MW unit, there installs two plate heat exchangers, heating condensation water respectively, which can improve the thermal efficiency. With two heat exchangers working under the design conditions, a test was carried out based on a 350 WM unit simulation system in order to test the influence of system for unit operation characteristics. Referring to the data, the investment of the heat exchanger can achieve 2.68 g/kWh coal saving during the non-heating period and 0.2531 g/kWh during the heating period.
Analysis on Application of New Technology and Material in Package Design
Authors: Jiang Wan Qiu , Zhang Ke , Shen De Kun , Zhang Jing
Published: September 2014

With the daily improving consumption and scientific technology, higher demands on package design are getting even rigorous no matter on industrial or daily products, relevant package materials have appeared with the development of ecological, anti-counterfeiting, buffer and sterile technologies, which severely improves the quality of modern packaging, bringing more convenience and surprise for our everyday life.
Application and Development of MEMS in the Field of Aerospace
Authors: Wang Jie Xuan , Qian Xin Ming
Published: September 2014

This paper briefly introduced the concept and technology of MEMS. It analyzed the applications of MEMS units、MEMS sensors in the field of aerospace. The importance and unique advantages of MEMS technology play an irreplaceable role in high-tech industries. Finally, this paper discussed the development of MEMS and provided direction for further study of MEMS technology.
PSCAD SVG Control Sampling Algorithm Based on C Language Modeling and Simulation
Authors: Du Yang , Xu Guo Lin
Published: September 2014

To use C to build the simulation process in PSCAD, directing current control algorithm by using dq0 transform, the C language code of simulation can be directly applied to the actual SVG controller. The PI parameters can directly guide the field set, avoiding the complicated scene setting.
Binderless-cBN as Cutting Material for Ultra-Precision Machining of Stainless Steel
Authors: Polte Julian , Polte Mitchel , Lorenz David , Oberschmidt Dirk , Sturm Heinz , Uhlmann Eckart
Published: September 2014

The ultra–precision cutting of steel materials is possible but needs modifications of machine tools or the workpiece material. One approach of actual research is the development of cutting materials that gives the opportunity for direct cutting of surfaces with ultra–precision quality. Binderless–cBN is here one of the most promising materials. The paper shows results of experimental studies with binderless–cBN as cutting material while turning stainless steel. Various investigations were carried out to determine the wear mechanisms. Furthermore, measurements are shown regarding the surface quality. The achieved results show the high potential ofbinderless–cBN as cutting material for the machining of steel.
Dry and Residue-Free Cutting with High-Pressure CO2-Blasting
Authors: Bilz Martin , Uhlmann Eckart
Published: September 2014

Jet cutting with high-pressure CO2 jets has the potential for a dry and residue-free machining of materials. However, a high-pressure CO2 blasting plant as well as experimental expertise for the continuous jet cutting with high-pressure CO2 at atmospheric conditions are not available. A pilot plant for the continuous jet cutting with liquid carbon dioxide was developed and realized at the Fraunhofer-Institute for Production Systems and Design Technology. Identical cutting tests were carried out in polyurethane blocks of different Shore D-hardness and density with high-pressure CO2 and water jets. Based on the first results in polyurethane blocks the tests were extended to cutting carbon fibre reinforced plastic plates with the high-pressure CO2 jet. Finally the possibilities and limits of the high-pressure CO2 jet cutting were summarised.
Analysis and Visualisation of the Positioning Accuracy and Underlying Effects of Industrial Robots
Authors: Ulrich Marco , Lux Gregor , Piprek Thomas
Published: September 2014

Industrial robots are usually not suitable for high-precision applications due to their limited absolute accuracy. This issue can be solved by calibrating the robot using an adequate model of its kinematic chain and physical behaviour. However, this presupposes a deep understanding of the effects that influence the absolute accuracy and repeatability of the robot. This paper outlines a set of experiments to gain this knowledge by analysing the effects that limit the precision and furthermore presents a way for the proper visualisation of the consequent errors. The investigation includes a range of robots with different characteristics to gather valid and preferably universal information for off-the-shelf industrial robots.
A New Approach for the Prediction of Surface and Subsurface Properties after Grinding
Authors: Jermolajev Stepan , Brinksmeier Ekkard
Published: September 2014

This paper presents a diagram of maximum contact zone temperature Tmaxversus contact time Δt, based on the analysis of workpiece surface layer properties after cylindrical grinding experiments. Apart from resulting surface layer properties, process quantities (Tmax, normal and tangential grinding forces Fn, Ft) are investigated with reference to the resulting workpiece surface layer state as well. Ground workpieces are analyzed by performing Barkhausen noise level measurements together with subsequent metallographic and X-ray diffraction investigations. By mapping characteristic values Tmax and the contact time Δt to corresponding surface layer properties, a general analysis of workpiece material response to the thermo-mechanical load during grinding is possible.
A New Method to Enhance the Accuracy of the Buckling Test Using Modified Yoshida Sample
Authors: Han Fei , Liewald Mathias
Published: September 2014

Because of the extensive use of thin sheet metals to reduce the weight of vehicles, wrinkling is becoming a more common and one of the most undesirable failures in the sheet forming process. Generally, experiments for studying wrinkling phenomena can be divided into two methods: actual forming of typical parts such as annular cup test on the one hand and the tests of specially designed sample geometries like the Yoshida Buckling test on the other. Recent experiments indicate that the plastic strains at the onset of wrinkling in the Buckling Test with Yoshida samples are too small to reflect reality of deep and stretch drawing conditions. Therefore, in this paper, in order to enhance the accuracy of the prediction of wrinkling, a new modified Yoshida specimen is provided for numerical simulation. The fundaments of the different buckling phenomena are going to be explained considering the energy theory in metal forming processes. Meanwhile, the influences of the changeable sample geometries in order to cause different stress distribution within loaded area of specimen have been investigated.
Considering Anisotropic Material Behaviour of Sheet Metals for Ductile Fracture Prediction
Authors: Sabathil Andreas , Heinle Ingo , Lipp Arnulf , Meinhardt Josef , Merklein Marion
Published: September 2014

In the manufacturing process of body in white components made from sheet metal it is state of the art to accompany the process by means of finite element analysis. A main criterion for determining a feasible tool design and process parameters is the prediction of material failure, which can be categorized in instability and ductile fracture. The ductile fracture failure mode is more likely to occur, as more advanced high strength steels and aluminium alloys are used for body in white components. Therefore various approaches have been presented to model ductile fracture over the past years. However, there is no guideline to determine which models are suitable for predicting ductile fracture. The same applies when it comes to choosing experiments and calibration of model parameters. A suitable model calibration is vital, as the fracture prediction depends on the determined model parameters. Usually an isotropic material behaviour is assumed for calibration of fracture models. However, sheet metals can show an anisotropic material behaviour due to the rolling process. Therefore it is arguable if an isotropic material model can be applied when fracture models are calibrated.
Worker Information Systems Including Dynamic Visualisation: A Perspective for Minimising the Conflict of Objectives between a Resource-Efficient Use of Inspection Equipment and the Cognitive Load of the Worker
Authors: Lušić Mario , Schmutzer Braz Konrad , Wittmann Stephan , Fischer Christian , Hornfeck Rüdiger , Franke Jörg
Published: September 2014

In the context of casting mould inspection, the conventional paper-based provision of information for workers can be characterised by a conflict of objectives. On the one hand, a minimisation of the cognitive load of the worker is desirable. To this end the inspection procedure is oriented on the complete processing of each view of the single-part drawing. This leads to a necessary change between inspection devices within individual views. On the other hand, a resource-efficient use of inspection equipment is desirable. To this end, the inspection tasks are grouped so that for each group one single inspection device is assigned. This requires a change between the views of the single-part drawing within each inspection device, which increases worker’s cognitive load. By means of a realistic representation of the inspection operations to be carried out, by using a Worker Information System which is based on animated graphical representations (dynamic visualisation), the increase of the cognitive load that is caused by the resource-efficient use of inspection equipment could be compensated.
Reproducibility of Wear Tests and the Effect of Load on Tool Life in Sheet Metal Forming
Authors: Christiany Matthias , Groche Peter
Published: September 2014

The increasing use of advanced high strength steels challenges the forming industry. Data on tool life are not available, thus causing uncertainties in the choice of suitable tribological systems. This paper investigates the reliability of a strip drawing test and the effect of the load level on tool life. Reproducibility of wear tests is barely discussed in literature. This study shows that a wear analysis on the base of a strip drawing test allows reproducible data. However, even small differences of the initial parameters can affect the result. A further investigation shows a distinct relationship between tool life and load level. Furthermore, the predominant wear mechanism is also influenced by the applied load. The findings on wear behaviour and reproducibility can be used for a new approach to estimate tool life in industrial forming processes on the base of a model test.
Spatial Programming for Industrial Robots: Efficient, Effective and User-Optimised through Natural Communication and Augmented Reality
Authors: Lambrecht Jens , Krüger Jörg
Published: September 2014

In this paper, we present a robot programming system taking into account natural communication and process integrated simulation as well as a unified robot control layer and an interface towards the Digital Factory for program transmission. We choose an integrative approach including markerless gesture recognition and a mobile Augmented Reality simulation on common handheld devices, e.g. smartphones or tablet-PCs. The user is enabled to draw poses and trajectories into the workspace of the robot supported with simultaneous visual feedback in Augmented Reality. In addition the user can adapt the robot program by gestural manipulation of poses and trajectories. Within a task-oriented implementation of the robot program a pick and place task was implemented through the programming by demonstration principle. With the help of a user study we evaluate programming duration, programming errors and subjective assessment compared with Teach-In and Offline Programming. The analysis of the results shows a significant reduction of programming duration as well as a reduction of programming errors compared with Teach-In. Furthermore, most participants favour the spatial programming system.
Methods to Design the Adjustment of Parameters for Thermal Machine-Tool Models
Authors: Kauschinger Bernd , Schroeder Steffen
Published: September 2014

Thermal models of machine tools contain parameters whose values have a high degree of uncertainty and which can limit the accuracy of the model beyond applicability. Thus, the parameters have to be adjusted by means of measurements. At present, substantial time, effort, and expensive measurement equipment are required for adjustment, as well as in-depth expertise. For these reasons, we have studied the development of methods providing rapid, comprehensive, and low-cost adjustment. This objective can especially be achieved by methods that support the planning stage of the model-adjustment procedure. The paper demonstrates this based on methods for model and behaviour visualisation.
Scientific Management 2.0 – A Design Model for Experimental Research in Production Management
Authors: Schuh Günther , Gartzen Thomas , Basse Felix
Published: September 2014

Reliable and accurate predictions on future states of production systems are the objective of production theories. In this paper, the authors determined shortcomings of current deterministic models and traced them back to the poor theoretical basis of scientific research in the area. The observations resulted in the development of the concept Scientific Management 2.0 as an appropriate research methodology for production management. This new empirical approach takes into account three requirements to scientifically precise investigations: It expands existing theory by socio-technical aspects, uses embedded experiments as a profound basis for investigation and provides a design that warrants the methodical exactness required. RWTH Aachen’s Demonstration Factory represents an adequate infrastructure to prove feasibility and performance of the new approach.
Target-Based Evaluation of Disturbances in Production Systems
Authors: Knüppel Konja , Nikitin Iwan
Published: September 2014

Ever-increasing networking and complexity make production processes more susceptible to disturbances. Being able to handle disturbances quickly and effectively is an evolving factor of a company's competitiveness. The research project "Nachhaltiges Störgrößenmanagement in produzierenden KMU" (Sustainable disturbance management in producing SMEs), conducted at the Institute for Production Systems and Logistics (IFA), is developing a methodology aimed at helping users identify and initiate actions against production disturbances. One research focus was on developing a causal factor chart of the interdependencies between target variables on the shop floor in order to obtain a faster and more objective means of evaluating the effects and significance of disturbances.
An Analytical Model Describing the Lateness Distribution of Storage Processes
Authors: Grigutsch Michael , Nywlt Johannes , Bertsch Sebastian
Published: September 2014

Enterprises are increasingly being challenged by a high diversity of variants, shortening product life cycles, and growing cost pressure. One possibility of facing these challenges is to improve the efficiency of logistics. As the borderline between a company's production with and without reference to a specific customer order, the customer order decoupling point (CODP) is a good position to significantly increase the efficiency of logistics. Apart from shortening lead times, it may also diminish the lateness at the end of the supply chain. There is currently no comprehensive analytical description of actual schedule variances within a supply chain. This paper presents a Lateness Histogram to serve as an analytical model designed to describe the mean and maximum delivery delay in a store (e.g. CODP). It is fed with the distribution of schedule and quantity variances at the store input as well as the distribution of demand at the store output. Thus, the model is another step towards analytically describing the potentials of implementing a CODP or moving it along the production process in order to obtain a possibility of quantifying the amount of lateness reduction as the CODP moves downstream. This is followed by empirical simulation studies aimed at validating the model.
Energy Performance Analysis on the Design Conditions of High-Rise Apartment Houses in South Korea
Authors: Jung Hae Kwon , Yu Ki Hyung , Jeong Young Sun
Published: September 2014

Aapartment houses account for more than 60% of the total of residential buildings to be built in South Korea. In particular, a high-rise apartment house with 21 floors or more has steadily increased in densely populated areas. The heating and cooling energy demand of the apartment house is greatly affected by the shape and the thermal insulation of its building envelope. In addition to its functional efficiency, the shape of building envelope in a high-rise apartment house is considered to be an important factor for the urban landscape with diverse construction methods and materials. In this study, we analyzed the heating and cooling energy demand depending on the effective heat capacity of building structure and the installation position of thermal insulation materials as the design conditions of high-rise apartment houses. This study used the ECO2 energy analysis program for the building energy efficiency grading certification system in South Korea.
Pressure Transient Modeling in Geothermal Reservoir by Using Picard-McLaurin Iteration
Authors: Singarimbun Alamta , Fujimitsu Yasuhiro , Djamal Mitra , Andajani Rezkia Dewi
Published: September 2014

Exploitation of geothermal resource results the decrease of fluid pressure in geothermal reservoir. In production process, the analysis of reservoir condition is made by observing the pressure state. When the fluid is pumped into the reservoir, the value of pressure varies with time which is called as transient state. The plot of pressure versus time will create a curve with a certain slope. From the graph of the pressure the reservoir condition can be analyzed. The solution of the pressure transient is identified as exponential integral equation Ei(x). When the input to the function is really small for example at x < 0.01, the equation will form an asymptotic curve. Analytical solution involves logarithm natural and Euler constant (γ). In this paper we try to approach the solution of exponential integral equation by numerical integration. The objective of this study is to make a numerical model of the pressure change in a geothermal reservoir and to compare the result between numerical method and analytic. There are two methods used in this study, first is Picard-McLaurin iteration to solve the ordinary differential equations (ODE), and the second is trapezoidal integration to calculate the function of Ei(x). The modeling shows that the result of the calculation with the numerical method matched with the analytic with the range of error between 0.0008 to 4.5 % for drawdown test and 0.19 to 7.7 % for buildup test.
Control Strategy Used on UAV Motion System
Authors: Zhou Hong Cheng , Jiang Zhi Peng
Published: September 2014

The servo control methods of 6-DOF motion configuration are researched. Based on analysis for characteristic of the motion configuration, the control strategy and control law used on the motion control system are presented. The controller in velocity tracking loop and location loop are respectively designed by frequency correcting method and normal control method which belongs to classical control theory. Sliding mode variable structure control method is presented for location control law designing, against the super low velocity creep caused by friction disturbance, so that the problem of location control loop low velocity creeping is solved, and a simulating experimentation demonstrate the effectiveness of the proposed approach.
The Application of Polymer Materials with High Mechanical Properties in Competitive Sports
Authors: Li Ning
Published: September 2014

With the development of science and technology, the requirements on the properties of new materials was increasing, polymer materials become one kind of important material type which has been widely used in the current human social activity. Due to its high properties such as strength, elasticity and toughness, polymer materials with high mechanical properties’ application in the field of competitive sports has incomparable advantages. This paper analyzes the characteristics of high mechanical properties of polymer materials and its advantage in competitive sports, in order to promote its application in the field of sports.
Effects of Laser Cladding Process on Cladding Layer Qualities of Nickel-Base Alloy
Authors: Zang Chun Cheng , Wang Yan Zhong , Zhang Yi Du
Published: September 2014

Nickel-base alloy powder is widely applied to strengthen the surface of products through laser processing. This paper presents the experiments on laser cladding of Ni45 alloy powder on substrates of 45 steel. The experimental results show that the laser cladding processing parameters such as laser power, scanning speed, powder feed rate and overlap ratio have great effects on the qualities of the cladding layer. Optimizing the processing parameters is an effective way to improve the layer qualities and obtain desired cladding layers.
Research Regarding the Manufacture of Pipelines through Automatic Tandem MAG Welding on Generators
Authors: Toma Cosmin , Iovanas Radu , Iovanas Daniela Maria
Published: September 2014

The manufacture of pipelines is a complex technological process starting with laminates supply, joints cutting-processing, rolling, welding, calibration, control, packing, delivery. As a rule, the technological welding process is achieved by welding on generators through MAG and submerged arc welding, procedures which generally take place completely automatically, affecting the quality and cost of products. Beside a series of advantages, submerged arc welding also has disadvantages; it does not eliminate the operator’s intervention and implies some high linear energies with implications on the mechanical-metallurgical characteristics of the welded joints. In this paper we present the preliminary results of the experiments which have been carried out on welded joints on X52 steel plate, g = 12 mm, through classical MAG welding, with one wire - filler material on the first layer, and the filling beads through tandem MAG welding, with two wires. We should mention that the plates had a V(30°) joint and the welding was executed unilaterally, horizontally, the wire - filler material being of the same quality G42 4 M G3 SI1 ( EN ISO 14341) and diameter (1.2 mm), and EN ISO 14175 protection gas. The entire technological welding process was carried out in laboratory conditions, fully robotized, using a QIROX-315 welding robot fitted with QUINTO-GLC 603-type tandem MAG welding installations, owned by ICDT-PRO-DD C12 “Advanced welding eco-technologies”, belonging to Transylvania University of Braşov.
The Effect of Silicon Content into the Aluminum Matrix on the Microstructure and Mechanical Properties of TIG/FSW Welds
Authors: Gheorghiu Diana Antonia , Toma Stefan Lucian , Bejinariu Costică , Bernevig Mihai
Published: September 2014

Aluminum silicon alloys, the 4xxx group of the aluminum alloys, are mostly processed into cast parts. As for other cast designated alloys, their weldability is often considered as an unimportant feature. The interest, if any, is almost completely related to the repair welding.The present work analyses how silicon particle dimensions, which depends mostly on the silicon content into the metallic matrix, affects the weld properties. Also it is revealed the HAZ metallographic aspect for two frequently welding processes used on aluminum alloys, TIG and FSW. Friction welds resistance is better than that of the TIG welds, associated with a lack of symmetry (retreating side versus advancing side).Silicon particles diminish their dimensions for hypo eutectic or eutectic concentrations; for hyper eutectic compositions the effect has an almost unimportant effect.
Analyzing Properties of New Hard Coating Technologies for Increasing the Wear Resistance
Authors: Milutinovic Zlatan , Ristic Marko , Vasovic Maksimović Ivana , Prokolab Milan , Gligorijevic Bojan
Published: September 2014

The aim of this paper is, improving the characteristic of Ventilation mill for grinding coal which is one of the main part of steam power plants in the system that makes a significant influence on the level of energy efficiency with its work. Working parts of the mil during exploitation are dominantly exposed to intensive abrasive and erosive wear and also to impact loading at elevated temperatures, which can lead to damage and fracture of homogeneous materials, thus shortening their working life. For solving the problem of increasing the wear resistance of the parts for transport and coal grinding in power plants, to investigate the optimum application of technology in hard coatings by different procedures, and filer materials. Hard coatings were carried out with cold (plasma and arc treatment) and hot metallization (with concurrent and subsequent drowning). It has been used the additional materials of different chemical composition and properties based on Ni (NiCrBSi; NiCrBSiFe; NiCrBSi / WC) and Fe (FeCrCSiMo; FeCrCBSiTi; FeCrCBNiSi). The main goal of this paper is to make the selection of optimum hardfacing procedures, group of filler materials and hardfacing technology definition based on the results of structural and mechanical properties of samples, experimental model hardfacing. These were investigation of its structure, measurement and distribution of hardness in the samples, tribology characteristic samples with hard coatings. Based on the results of these tests there were selected the additional materials and procedures for applying hard coatings, which would be apply in the revitalization of parts in transport at and coal grinding.
Study Regarding the Cavitation Erosion Behaviour and Residual Stresses of Impact Resistant Hardfacing Materials
Authors: Secosan Evelina Roxana , Ciubotariu Relu Costel , Cojocaru Vasile , Frunzaverde Doina , Câmpian Constantin Viorel
Published: September 2014

In the last twenty years the cavitation erosion resistance of various welded materials was subject of extensive studies. Despite these, the research field is still opened. The multitude of materials used for the fabrication of hydraulic equipment and the variety of the operating conditions in hydropower units require adapted solutions. This paper presents the investigations made on welded overlays realized using an impact resistant hardfacing alloy, recommended by manufacturers for protection against cavitation erosion.
The material was characterized by metallographic investigations (light microscopy, scanning electron microscopy and EDX–analyse), Vickers micro hardness tests, residual stresses measurements carried out by the hole-drilling strain-gage method and cavitation erosion tests using the vibratory method. The results of the cavitation erosion tests were correlated to the behaviour of the martensitic stainless steel 1.4313 (grade X3CrNiMo13-4 corresponding to EN 10088-3) frequently used for the manufacturing of the hydraulic turbine components.
The Increasing of Corrosion Resistance of Low Alloy Carbon Steels Used in Petroleum Industry through Coating with Alloys Based on Fe-Ni-Cr by Thermal Spray
Authors: Toma Stefan Lucian , Peneoasu Margareta , Bejinariu Costică , Gheorghiu Diana Antonia , Eva Lucian , Toma Bogdan
Published: September 2014

The main objective of this paper is to evaluate the mechanical properties, chemical and corrosion resistance of four types of metallic coatings: FeCr, FeCoCr, and FeCoCrNi, FeCrNi sprayed through thermal spraying in electric arc on an anchor substrate type 95Ni5Al or 78.3Ni20Cr1. 4Si0.3Fe. The five layers tested were deposited on carbon steel support low alloyed and the obtained results have provided a picture regarding the possibilities of using of the deposits. Because these types of alloys are used to increase the wear resistance of tools, it is very important to know their behaviour is saline environment, because the contributions brought by this paper would increase the applicability domain of these materials (could be used to recondition by thermal spraying the tools used in naval and petroleum industry). The researches of the obtained deposits have been carried out through several methods to screen their performance. Therefore, there have been done investigations on the microstructural morphology of the deposit, by optical microscopy (OM) and scanning electron microscopy (SEM). The OM and SEM results have sought to determine the degree of uniformity of the deposits and the amount of pores and oxides in layer. The physical properties of coatings were also evaluated by adhesion and porosity quantification. The corrosion resistance was evaluated by exposing samples in saline fog chamber. The corrosion products formed on the surface layers were investigated by scanning electron microscopy (SEM) analysis of the SEM. The intermediate alloy 78.3Ni20Cr1.4Si0.3Fe used as anchoring layer allowed the reducing of the pores and micro cracks frequently found in the ordinary 95Ni5Al alloy. It has been observed that the deposits based on NiCrCo are good enough to be used as an efficient coating of carbon steel in aggressive marine environments.