bluuebunny/crossref_metadata_2025 huggingface dataset:
Development of a Wireless Displacement Measurement System Using Acceleration Responses
Authors: Park Jong-Woong , Sim Sung-Han , Jung Hyung-Jo , Jr. Billie
Published: July 2013

Displacement measurements are useful information for various engineering applications such as structural health monitoring (SHM), earthquake engineering and system identification. Most existing displacement measurement methods are costly, labor-intensive, and have difficulties particularly when applying to full-scale civil structures because the methods require stationary reference points. Indirect estimation methods converting acceleration to displacement can be a good alternative as acceleration transducers are generally cost-effective, easy to install, and have low noise. However, the application of acceleration-based methods to full-scale civil structures such as long span bridges is challenging due to the need to install cables to connect the sensors to a base station. This article proposes a low-cost wireless displacement measurement system using acceleration. Developed with smart sensors that are low-cost, wireless, and capable of on-board computation, the wireless displacement measurement system has significant potential to impact many applications that need displacement information at multiple locations of a structure. The system implements an FIR-filter type displacement estimation algorithm that can remove low frequency drifts typically caused by numerical integration of discrete acceleration signals. To verify the accuracy and feasibility of the proposed system, laboratory tests are carried out using a shaking table and on a three storey shear building model, experimentally confirming the effectiveness of the proposed system.
BENCHMARKING OF MAINTENANCE AND SERVICE PROCESSES IN AIR TRAFFIC CONTROL SYSTEMS
Authors: Kabashkin Igor , Kundler Jörg
Published: July 2013

A theoretical analysis and benchmark was performed to develop a service model for air traffic control (ATC) systems. Based on a survey of theoretical methods and approaches for ATC maintenance processing in relation to traditional and European harmonised ATC parameters, a structured analysis and evaluation of the problem was performed at an international ATC organisation. The research was performed with parameter-oriented comparison. The results of the research were used in a process maturity assessment and key performance indicator (KPI) system. An ATC-specific maintenance process maturity method based on ISO/IEC Standard 15504 was developed for the process of analysis.

The results can be used to develop an ATC service maintenance model as part of an air transport system model (macro model) and to develop an ATC service model and KPI system (micro model).
La influencia de la presencia militar brasileña en Corrientes durante la guerra de la Triple Alianza
Authors: Ramírez Braschi Dardo , Caño Ortigosa José Luis
Published: July 2013

La guerra de de la Triple Alianza provocó cambios en la política interna de cada uno de los países beligerantes. Argentina especialmente, ya que el territorio de la provincia de Corrientes se convirtió en el primer escenario de batalla. Por esa razón, los ejércitos aliados se instalaron en territorio correntino, adquiriendo especial relevancia las fuerzas brasileñas, que pronto se constituyeron como un factor clave para el ejercicio del poder en aquella provincia.
El retorno como patrimonio en la obra de María Rosa Lojo
Authors: Broullón Acuña Esmeralda
Published: July 2013

El siguiente artículo examina la configuración del retorno heredado en los hijos del exilio hispanoargentino. Identidad, memoria y retorno son los ejes que estructuran un texto que toma como punto de partida la cultura narrativa hispanoargentina contemporánea. Ésta se erige en un espacio explorativo sobre la identidad, en cuanto a tarea ontológica del sujeto transterrado. Por ello nos centramos en una de las investigadoras más representativas del panorama histórico-literario argentino como es María Rosa Lojo. Su imaginario se asienta sobre la memoria del retorno y su transmisión patrimonial. Si bien analizaremos dicha concepción mitológica a través de la trama de su primera novela: «Canción perdida en Buenos Aires al oeste» y la confluencia de esta temática en su trayectoria.
Métodos para la limpieza física, química y biológica de las fábricas de piedra de monumentos históricas. El caso de San Lorenzo del Real de Burgos
Authors: Garabito J. , Manso J. M. , Rodríguez A. , Garabito J. C. , Calderón V.
Published: July 2013

El presente artículo muestra el proceso de restauración de las fábricas de piedra en monumentos históricos. La intervención tiene que llevarse a cabo de acuerdo a la personalidad del monumento, recuperando su aspecto original. En este artículo se describe el proceso de restauración de la fachada principal de la Iglesia de San Lorenzo el Real en Burgos (España), como un ejemplo de monumento histórico situado en ambientes urbanos. En primer lugar, se realiza una investigación histórica y se recopila toda la documentación existente tanto de su evolución constructiva como de la naturaleza de sus materiales. Caracterizamos las diferentes variedades de piedra caliza y analizamos los morteros de juntas de las fábricas de piedra. Una vez conocidas las características y propiedades de los materiales y su grado de deterioro, se establecen los métodos de limpieza a utilizar. Las actuaciones realizadas han conseguido recuperar el monumento, con la restauración de la fachada principal.
Learning to Play, Playing to Learn
Authors: De Grove Frederik , Van Looy Jan , Mechant Peter
Published: July 2013

Learning opportunities offered by digital games have become an important research topic in recent years. Language learning is one of the areas in which games could prosper but the question then is whether these should be specialized language-learning games or commercial off-the-shelf games for entertainment. The goal of this paper is to compare the experiences evoked by playing a commercial and two language-learning games in adult foreign language learners (N=62). While results of the experimental design suggest that a commercial game results in better playing and learning experiences, these findings are partly neutralized by the attitude of the participants towards learning through digital games and by being a frequent player of games or not. This raises questions as to how digital games should be designed to appeal to a public of learners that is not familiar with digital game-based learning or with gaming in general.
The Opinions and Attitudes of the Foreign Language Learners and Teachers Related to the Traditional and Digital Games
Authors: Uzun Levent , Ekin M. Tugba Yildiz , Kartal Erdogan
Published: July 2013

The present study aimed at investigating the differences between the teachers and the ‘new generation’ of learners, their opinions about which language skills would benefit more from games, and the nuances of the two genders (male and female), while also revealing the profiles and tendencies of different age groups in relation to their fascination with playing traditional or digital games. The subjects were 131 foreign language learners or teachers from five different age groups, ranging between 7 and 50. The data were collected and analysed through both qualitative and quantitative constructions. Results suggested that female subjects were mostly in favour of traditional games, and liked to play educational games more than their male counterparts, while also it was revealed that from among the six language skills, vocabulary seemed to have the potential to benefit most considerably from games.
Effects of Terms Recognition Mistakes on Requests Processing for Interactive Information Retrieval
Authors: Omri Mohamed Nazih
Published: July 2013

In this work the author proposes to describe a new model of information retrieval. They studied the effects of using weighted index terms recognition mistakes in a document indexing system and evaluate indexing performance when short and long requests are used. The effect of weighting index terms in the document collection and in the requests is analyzed. Given the typical requests submitted to term indexing system, it seems easy to consider that the effects of term recognition mistakes in user requests must be severely destructive on the effectiveness of the system. The experimental study reported in this paper shows that the use of classical term Indexing technique for processing this kind of request is robust to considerably high levels of term recognition mistakes, in particular for long requests. Moreover, both standard pertinence feedback and pseudo pertinence feedback can be employed to improve the effectiveness of user request processing.
On Knowledge-Enhanced Document Clustering
Authors: Rege Manjeet , Koruthu Josan , Bailey Reynold
Published: July 2013

Document clustering plays an important role in text analytics by finding natural groupings of documents based on their similarity determined by the words appearing in them. Many of the clustering algorithms accessible through various text analytics tools are completely unsupervised in nature. That is, they are unable to incorporate any domain knowledge that might be available about the documents to improve the clustering accuracy and relevance. The authors present a graph partitioning based semi-supervised document clustering algorithm. The user provides knowledge about few of the documents in the form of “must-link” and “cannot-link” constraints between pairs of documents. A “must-link” constraint between two documents expresses the fact that the user feels that the two corresponding documents must be clustered irrespective of their dissimilarity. Similarly, a “cannot-link” signifies that the two documents should never be clustered together no matter how similar they might happen to be. These constraints are then incorporated into a graph partitioning based into a computationally efficient document clustering algorithm. Through experiments performed on publicly available text datasets, the proposed framework is validated.
Weighing System by Load Cell Response Rectification Method
Authors: Chatterjee Karunamoy , Mahato Sankar Narayan , Chattopadhyay Subrata
Published: July 2013

In the area of mass production, the products are weighted using load cell based weighting system. A load cell may be capacitive or resistive, is an uncontrollable weighing device. Load cell response rectification can be used to speed up the process of measurement. This paper investigates the application of analog adaptive techniques in load cell response rectification and modeling of an accurate weighing system by using that load cell. The load cell is a sensor with an oscillatory output in which the measurand contributes to response parameters. Thus, a compensation filter needs to track variation in measurand whereas a simple, fixed filter is only valid at one load value. To facilitate this investigation, computer models for the load cell and the adaptive compensation filter have been developed and implemented in PSpice. Simulation results are presented demonstrating the effectiveness of the proposed compensation technique.
Biodiesel Production from Algal Blooms
Authors: Urooj Shabana , Hussain Athar , Srivastava Narayani
Published: July 2013

Usage of Bio-energy is becoming more and more prominent due to the peak oil crisis. Bio-energy is the energy which can be synthesized using methods and raw material which are available in nature and are derived from the biological sources. They are referred as bio-mass energy, bio-diesel, and bio-power. In this paper the study has been carried out on bio-energy generation in form of bio-diesel and the bio-diesel is produced in the laboratory conditions by using base catalyzed trans-esterification process. The nomenclature bio-diesel is given to the oil which can be generated by using the raw materials which are renewable and are waste materials. It doesn’t contain any percentage of petroleum products in it. It is called bio-diesel because it can be further used to run the diesel engine. In this paper biodiesel is generated using local pond algae by the process of base catalyzed trans-esterification.
The Perceived Work Ethic of K-12 Teachers by Generational Status
Authors: Petty Gregory C.
Published: July 2013

This was an investigation of the work ethic of K-12 educators from Generation X and Baby Boomer generations. Teachers of the baby boom generation were born between 1946 and 1964, and many are beginning to retire. There is an impending teacher shortage due to the large numbers of this group retiring or leaving the profession. School administrators and public school human resource specialists are beginning to focus on strategies to replace this experienced workforce. Administrators need to know if this group has different work ethic than later groups of teachers. In this study, Generation X teachers scored higher on the subscales of Easy Going, Dependable, and Committed. While Baby Boomers and Generation X teacher about the same on Dependable, Baby Boomers are more “engaged”. Though these differences in the subscales were not significant, The overall MANOVA for the comparison of work ethic as measured by the Occupational Work Ethic Inventory was significant at the p<.05 level. Many older teachers complain about the newer younger generation of teachers and their so-called “lack of a work ethic”. Unfortunately, there were not enough data to study teachers from the latest, millennial generation however, this study points to data that indicate there is more to this difference in perception that originally thought that could affect hiring and training of new generations of teachers.
SCAX
Authors: Nemati Hamid , Udiavar Antara
Published: July 2013

Supply chains today amass huge amounts of data. To remain competitive in a global economy, organizations need to constantly derive meaningful information from this plethora of data to make critical business decisions. The process of gaining meaningful and actionable knowledge from supply chain related data is referred to as Supply Chain Analytics (SCA). As a result of demonstrated benefits from SCA, organizations are spending considerable amount of resources to develop these analytical capabilities. However, due to complexities of such undertakings, many SCA projects fail to achieve the desired results. It is argued that a major reason for such failures is lack of organizational readiness to embrace analytics. This paper presents an index for measuring the readiness of organizations to successfully implement SCA. The Supply Chain Analytics Index, henceforth referred to SCAX, was developed by surveying 112 SCA professionals from 7 countries and from various industries and professional backgrounds. Using this index, organizations can tangibly assess their readiness to take full advantage of the power of SCA.
Mobile Business Intelligence
Authors: Brodzinski James , Crable Elaine , Ariyachandra Thilini , Frolick Mark
Published: July 2013

Demand for business intelligence (BI) applications continues to grow at a rapid pace. Business intelligence via mobile devices is the latest frontier to drive demand among organizations interested in BI applications. However, mobile BI is still in its infancy. There are many opportunities to advance the way users use and interact with BI applications using mobile BI. Nevertheless, there are many challenges and issues that still require attention to attain mobile BI success. This paper highlights the state of mobile BI solutions and strategies to consider during a mobile BI implementation. It also discusses the challenges and opportunities mobile BI presents to organizations.
Education Portal on Climate Change with Web GIS Client
Authors: Pechanec Vilém , Vávra Aleš
Published: July 2013

E-learning as the use of new multimedia technologies and the Internet is widely used to improve the quality of learning. This leads to improved quality of the pupils’ and students’ learning approach. The research aim is to create e-learning courses with a thematic focus on the climate and its change consisting accurate information from the field of climate change and environment. The main objective of the courses is to provide educational materials to various groups of users, focusing on natural and social sciences related to the climate change. During the creation of e-learning courses the authors faced the following problem: the e-learning system they used, Moodle, did not include any modules for work with maps or geodata. Their solution is based on the LMS Moodle and thin client which was created with the use of ArcGIS Server.
On the Geographic Allocation of Open Source Software Activities
Authors: von Engelhardt Sebastian , Freytag Andreas , Schulz Christoph
Published: July 2013

This article contributes to research on the geographic origin of open source software (OSS) developers by analyzing the geographic allocation of active OSS developers and OSS activities. Based on data from the SourceForge Research Data Archive, the authors exploit information about developers’ IP address, email address, and indicated time-zone. This enables them to assign 94% of all registered users in 2006. As proxy for activity the authors use information about the number of posted messages. Thus they provide a detailed picture of the world-wide allocation of OSS activities. Such country data about the supply-side of OSS is a valuable stock for both cross-country studies on OSS and country-specific research and policy advice.
Social Networking and Health
Authors: Curran Kevin , Mc Hugh Michael
Published: July 2013

The rise of social networking has revolutionised how people communicate on a daily basis. In a world where more people are connecting to the internet, social networking services create an immediate communication link between users. Social networking sites provide multiple services which include emailing, instant messaging, uploading files, gaming and finding friends. Just as social networking has become a more popular method of communication in recent years, the ways in which people look after our health has also changed. People do not just rely singly on medical expert’s views anymore. They actively search for information on their own accord through the internet. Social Networking gives users both the option to gather, provide and comment on information. This research paper looks into if and how social networking can be successfully used within the health arena.
A Survey and Comparison of Optimization Methods for Solving Multi-Stage Stochastic Programs with Recourse
Authors: Sauma Enzo
Published: July 2013

In the last decade, multi-stage stochastic programs with recourse have been broadly used to model real-world applications. This paper reviews the main optimization methods that are used to solve multi-stage stochastic programs with recourse. In particular, this paper reviews four types of optimization approaches to solve multi-stage stochastic programs with recourse: direct methods, decomposition methods, Lagrangian methods and empirical-distribution methods. All these methods require some form of approximation, since multi-stage stochastic programs involve the evaluation of random functions and their expectations. The authors also provides a classification of the considered optimization methods. While decomposition optimization methods are recommendable for large linear problems, Lagrangian optimization methods are appropriate for highly nonlinear problems. When the problem is both highly nonlinear and very large, an empirical-distribution method may be the best alternative.
Generating Alternatives Using Simulation-Optimization Combined with Niching Operators to Address Unmodelled Objectives in a Waste Management Facility Expansion Planning Case
Authors: Yeomans Julian Scott , Gunalay Yavuz
Published: July 2013

Public sector decision-making typically involves complex problems that are riddled with incompatible performance objectives and possess competing design requirements which are very difficult – if not impossible – to quantify and capture when supporting decision models need to be constructed. There are invariably unmodelled design issues, not apparent at the time of model creation, which can greatly impact the acceptability of the solutions proposed by the model. Consequently, it is generally preferable to create several quantifiably good alternatives that provide multiple, disparate perspectives and very different approaches to the particular problem. These alternatives should possess near-optimal objective measures with respect to the known modelled objective(s), but be fundamentally different from each other in terms of the system structures characterized by their decision variables. By generating a set of very different solutions, it is hoped that some of the dissimilar alternatives can provide very different perspectives that may serve to satisfy the unmodelled objectives. This study shows how simulation-optimization (SO) modelling can be combined with niching operators to efficiently generate multiple policy alternatives that satisfy required system performance criteria in stochastically uncertain environments and yet are maximally different in the decision space. This new stochastic approach is very computationally efficient, since it permits the simultaneous generation of good solution alternatives in a single computational run of the SO algorithm. The efficacy and efficiency of this modelling-to-generate-alternatives (MGA) method is specifically demonstrated on a municipal solid waste management facility expansion case.
An Uncertain Decision Making Process Considering Customers and Services in Evaluating Banks
Authors: Akbari Fatemeh , Fazlollahtabar Hamed , Mahdavi Iraj
Published: July 2013

In today’s changing environment two properties are required to service namely good relation with customers and service quality. Nowadays no organization can get great achievement unless it can attract sufficient customers providing better service quality is important for service firms. This paper proposes a novel combined approach utilizing group decision making process to evaluate and rank criteria influencing the customer relationship management and service quality of four banks in Iran based on fuzzy decision making trial and evaluation laboratory (Fuzzy DEMATEL) and fuzzy analytic network process (Fuzzy ANP). Defuzzification of decision makers’ judgments is handled by Converting Fuzzy data into Crisp Scores (CFCS) method. Fuzzy DEMATEL is applied to deal with inner dependencies among criteria. Fuzzy ANP is used to compute final ranking of four banks as an empirical example. An empirical study is presented to illustrate the application of the proposed method.
FSaaS
Authors: Di Sano Marco , Di Stefano Antonella , Morana Giovanni , Zito Daniele
Published: July 2013

In this paper, the authors introduce and describe the concept of File System as a Services (FSaaS), an highly configurable cloud service that enables cooperating, distributed applications to define their own rules and policies for managing sets of files shared. The FSaaS aims to create a logical virtual space, containing references to shared files, whose management layer supports the same functionalities of a file system (basic file operations) but where each single file can have different policies for consistency, synchronization and replication. This work explains the idea at the base of FSaaS, describes in details its main components and their interactions and illustrates two use cases for better explaining the provided functionalities.
Teaching Experience on Metal Forming Processes through Case Study Methodology
Authors: Estévez A. , Doblas F. Javier , Vallellano C. , Morales-Palma D. , Centeno G. , Martínez-Donaire A.J. , García-Lomas F.J.
Published: July 2013

The aim of this contribution is to promote the use of FEM based numerical simulations for teaching the fundamentals of manufacturing processes. In particular, it focuses on metal forming processes, which by their mathematical modelling complexity can only be tackled in a very elementary way using traditional methods. This enables an active teaching based on realistic problem solving, through which students acquire both theoretical and practical knowledge on the subject. This approach is consistent with the guidelines of the European Higher Education Area (EHEA) on the use of participatory learning tools.
Prevalence of Aero-Allergenic Micro Fungi in Extra & Intramural Environments of a Saw Mill in Pondicherry City, India
Authors: Nayak B.K. , Kumar S. Suresh , Nanda Anima
Published: July 2013

Prevalence of airborne fungal spores with their seasonal periodicity in the extra and intramural environments of a saw mill of Pondicherry region was carried out by gravitation method from January 2011 to December 2011. Composition and concentration of fungal spores considerably varied from indoors to outdoors as well as from season to season. Indoor air harbored maximum fungal spores (61%) in comparison to outdoor air (39%). Occurrence of fungal species was predominated with more number of propagules during mid winter (December) and early rainy (July) periods in comparison to other months. Quantitatively, Cladosporium was found with the highest frequency and had four members i.e., C. cladosporioides, C. herbarum, C. resinae, C. sphaerospermum but qualitatively, Penicilli and aspegilii were isolated highest in its contribution to total CFUs. Out of the 32 isolated fungal taxa, Aspergillus fumigatus, A. niger, Rhizopus stolonifer and Alternaria alternata were the predominant aeroallergens which cause different types of respiratory/lung diseases in atopic human beings were isolated. In seasonal periodicity, winter contributed the maximum spore load (41%) followed by rainy (33%), summer was found with the least (26%) in harboring the spore mass in the indoors and outdoors. Alternaria alternata, which is accounted as a human allergen for sporosis inducer and an agent for hay fever and other pathologies, was also intermittently recorded. A few plant pathogenic fungi like Helmithosporium sp. & Fusarium spp, saprophytic, field and storage fungi were also recorded during the study period. Effect of meteorological parameters on the fungal spores in the saw mill atmosphere was significantly assessed by Pearsons correlation coefficient analysis.
Large Scale Production of MgO Nanostructures and their Possible Applications
Authors: Shah M.A.
Published: July 2013

The unique properties of nanomaterials have motivated the researchers to develop the simpler and inexpensive techniques to produce nanostructures of technologically important materials. Several oxide nanostructures are produced to have tremendous applications in the future and among them, magnesium oxide (MgO) is an exceptionally important material for use in catalysis, toxic waste remediation, as an additive in refractory, paint and superconducting products Fang et a. (2006).
Effect of Fiber Cross-Sectional Shape and Nano ZnO/Modified Chitosan Loading on Antibacterial Properties
Authors: Suwannamek Natthaphop , Ruangpaisarn Nanjaporn , Prahsan Chureerat
Published: July 2013

Antibacterial polypropylene cross-sectional shape fibers were melt spun with adding nano ZnO and modified chitosan. Two types of fiber cross-section, round and worm cross-sectional shape were studied including with nano ZnO and modified chitosan loading. Antibacterial properties, surface area, and fiber crystalization were investigated. The surface area of the fiber and antibacterial properties were directly related to the cross-sectional shape. The greater antibacterial properties was found at lower modified chitosan loading compared ZnO.
Evaluation of Electric Power of SOFC Using Reformed Biogas
Authors: Furukawa Naoki , Hirata Yoshihiro , Sameshima Soichiro , Matsunaga Naoki
Published: July 2013

Biogas of about 60 % CH4 -40% CO2 composition is produced from waste food or drainage. Electrochemical reforming of CH4 with CO2 using a porous gadolinium-doped ceria (GDC) cell is an attractive process to produce a H2-CO fuel used in solid oxide fuel cell. The supplied CO2 is converted to CO and O2- ions by the reaction with electrons at cathode (CO2 + 2e- → CO + O2-). The produced CO and O2- ions are transported to the anode through a porous mixed conductor GDC electrolyte. In the anode CH4 reacts with O2- ions to produce CO, H2 and electrons (CH4 + O2- → CO + 2H2 + 2e-). This process suppresses the carbon deposition from CH4. The formed H2 and CO fuels were supplied to a solid oxide fuel cell with dense GDC electrolyte (Ce0.8Gd0.2O1.9). The open circuit voltage and maximum power density were measured for the reformed gas and for a pure H2 fuel. Little difference in the electric power was measured at 1073 K for both the fuels.
Fabrication and Consolidation of TiNx by Pulsed Electric Current Sintering
Authors: Suarez-Vazquez Santiago I. , Nanko Makoto
Published: July 2013

A new and simple method is proposed to fabricate fully dense and single fcc phase of substoichiometric titanium nitride (TiNx). Powders mixture composed of titanium hydride (TiH2) and titanium nitride (TiN) was consolidated by using pulsed electric current sintering. All samples showed relative density values higher than 98% with larger grain size at lower nitrogen concentration. Lattice parameter increased linearly with increasing [N]/[Ti] ratio. In addition, TiNx with substoichiometric compositions was more easily densified than stoichiometric TiN. The addition of TiH2 improves the sinterability of the samples preserving the fcc phase characteristic of TiN.
Recovery of Silicon and Silicon Carbide Powder from Waste Silicon Wafer Sludge
Authors: Kwon Woo Teck , Kim Soo Ryong , Kim Y. , Poudel Jee Ban , Oh Sea Cheon
Published: July 2013

In an environmental and economic point of view, recycling of silicon wafer sludge is important. The aim of this work is to investigate the recycling method of silicon wafer sludge. Therefore, drying rate of silicon wafer sludge has been studied for separation of liquid and solid from sludge. Silicon and silicon carbide powder obtained from silicon wafer sludge were analyzed by SEM, XFR, XRD and particle size analyzer. The recovered oil was also characterized using GC-MS. From this work, it can be seen that the falling drying rate of silicon wafer sludge is linear equation. Various metal components have been found in recovered solid powder caused by wire sawing processing.
Characterization of Silicon Kerf and the Effect of Grinding on the Synthesis of SiC Powder
Authors: Kwon Woo Teck , Kim Soo Ryong , Kim Y. , Lee Yoon Joo , Won Ji Yeon , Ko Tae Gyung , Oh Sea Cheon
Published: July 2013

Characterization of silicon kerf from photovoltaic silicon-wafer production was carried out. Also, SiC powder was synthesized using high purity silicon kerf by varying grinding conditions. With increase of grinding time, surface of the silicon was oxidized to form silicon oxide. Also, it was observed that the unreacted silicon oxide and free silicon amount in the SiC powder increases with an increasing grinding times, even though silicon particle size of the starting material is decreased.
Eco-Fabrication of Metal Nanoparticle Related Materials by Non-Equilibrium Reaction Field
Authors: Hayashi Yamato , Sekiguchi Yoshihiro , Yamada Takahiro , Takizawa Kou , Koubu Hiroaki , Fukushima Jun , Takizawa Hirotsugu
Published: July 2013

Eco (Ecology & Economy)-fabrication is important in the future manufacturing. There are some elements to achieve this synthesis. When synthesizing, neither waste nor the air pollutant are not generated, and it is safe material is preferable with cheap fabrication device. We developed a new metal nanoparticle related materials synthesis method that achieved in these viewpoints. This new synthesis method is with microwave as non-equilibrium reactor and the metal oxide and alcohol based solvent are used for the raw material. Moreover, the oxide and alcohol generally are cheap without toxicity. We synthesized metal nanoparticle related materials by microwave in liquid-solid (alcohol - metal oxide) slurry and controlled morphology of products. Microwave irradiation in liquid-solid process can be expected as chemical non-equilibrium and nonlinear reactors for metal nanoparticle related materials synthesis. The alcohol based solvent and the metal oxide powder are put in the beaker and only irradiated by ultrasound or microwave. The metal oxide simply was reduced into metal and morphology of metal nanoparticles was changed by various conditions. Various metal nanoparticle related materials were fabricated by microwave irradiation as non-equilibrium reaction field.
Enhancement of Grain Refinement and Formability of Cross Roll Rolled Ni-10Cr Alloy
Authors: Song Kuk Hyun , Kim Han Sol , Kim Won Yong
Published: July 2013

This study evaluated the microstructure and mechanical properties enhancement of cross roll rolled Ni-10Cr alloy, comparing with conventional rolled material. Cold rolling was carried out to 90% thickness reduction and subsequently annealed at 700 °C for 30 min to obtain the fully recrystallized microstructure. Particularly, cross roll rolling was carried out at a tilted roll mill condition of 5º from the transverse direction in RD – TD plane. Application of cross roll rolling on Ni-10Cr alloy contributed to the notable grain refinement due to higher effective strain than that of conventional rolling, consequently, average grain size was refined from 135 µm in initial material to 4.2 µm in cross roll rolled material. Furthermore, //ND texture in CRR material was well developed than that of CR material, which contributed to the mechanical properties and formability enhancement.
Effect of Heating Process on Retained Austenite of Mn-TRIP Steel
Authors: Luo Hai Wen , Qiu Chang Han , Dong Han , Shi Jie
Published: July 2013

nfluences of various heating processes on the amount of retained austenite after an intercritical annealing were investigated experimentally in a Mn-alloyed TRIP steel. The heating with a higher rate or an interruption at lower temperature can lead to the more rapid formation of austenite during intercritical annealing and hence more retained austenite in final microstructure. Such an enhanced austenitization kinetics is attributed to the rapid dissolution of fine carbides having previously precipitated out at low temperature during the heating, which is also confirmed by the numerical simulations.
Modeling of Microstructure and Mechanical Properties of Hot Rolled Steels
Authors: Sokolov Dmitry F. , Ogoltcov Alexey A. , Vasilyev Alexander A. , Kolbasnikov N.G. , Sokolov S.F.
Published: July 2013

An integral mathematical physically based model is developed for prediction of the microstructure and mechanical properties of steels processed in accordance with a given hot deformation and accelerated cooling regimes. The model predicts austenite microstructure evolution under hot deformation, as well as its transformation during subsequent cooling with account of formation of ferrite, pearlite, bainite and martensite. Structure-property relationships are developed using an extensive experimental database chemical composition - microstructure - mechanical properties obtained for 10 steel grades. Austenite transformation depending on grain size, cooling rate and preliminary plastic deformation was investigated with the help of Gleeble 3800 system to obtain a set of practically important morphologically different microstructures for each steel grade. A quantitative analysis of the microstructures was performed using optical and scanning electron microscopy (EBSD-method). Investigation of the mechanical properties of steels with wide spectrum of obtained microstructures was carried out on the double-samples processed using Gleeble 3800. The predicted microstructure parameters for investigated steels obtained using the developed model, as well as their mechanical properties, are in good agreement with the experimental data.
Characterization and Modeling of Softening Kinetics during Hot Deformation in Modern Steels
Authors: Khlopkov Kirill , Paul Georg , Pretorius Thomas
Published: July 2013

A model describing the kinetics of static recrystallization and the kinetics of Nb and Ti precipitation has been reconsidered for modern steels. The effects of alloying and microalloying elements have been introduced into the model. The comparison of the modeling with the experimental softening shows good agreement.
Development of Nano-Scale Precipitation Strengthened Hot-Rolled 590MPa Grade Wheel Steel
Authors: Wang Xiao Nan , Du Lin Xiu , Di Hong Shuang
Published: July 2013

In order to promote the production of lightweight automobiles and enhance the strength grade of the automobile wheel steel, a nanoscale precipitation strengthened hot-rolled 590MPa grade wheel steel was developed to replace the Q235 steel, which was originally use for the wheel. The new wheel steel type was based on a C-Mn steel composition, microalloyed with Nb, V and Ti, thus making full use of the strengthening from both grain refinement as well as nanoscale precipitation. The microstructure of the wheel steel was composed of fine-grained ferrite and pearlite and carbides distributed along the ferrite grain boundaries. The yield and tensile strengths of the strip were about 550 MPa and 620 MPa, respectively. The value of hole expansion rate was 90%. The strip has shown high low temperature impact toughness and cold formability. The strengthening mechanisms of the strip were mainly governed by grain refinement and nanoscale precipitation (Nb,V,Ti)C, and the amount of the contribution from precipitation strengthening alone was about 215 MPa. The finishing rolling start temperature was about 950°C and the finish rolling temperature was between 790~830°C. Coiling temperature of 650°C gave the best combination of mechanical properties.
Physical Modelling the Microstructure Formation in Advanced High-Strength Steels
Authors: Sietsma Jilt
Published: July 2013

For the production and development of Advanced High-Strength Steels adequate understanding of the formation mechanisms of the metallic microstructure is crucial. The superior properties of these steels are based on a sometimes delicate balance between thermodynamic (in) stability and dynamic processes, in which thermodynamic driving force and interface kinetics determine the development of the microstructure of the steel. In order to achieve further development and optimisation of such steels, experimental and modelling studies should go beyond microstructural characterisation in terms of average properties only. In this paper some examples will be given in which full (3D-) microstructures are simulated on the basis of the evolution of diffusional transformations. Although nucleation is not understood to sufficient extent to be predicted quantitatively, growth can adequately be described as governed by short-range diffusion at the interface (the basis for the interface mobility) and, in case of a partitioning phase transformation, the long-range diffusion behaviour (most notably of carbon). Whereas in the literature often one of the two processes is assumed to be rate-determining (interface control or diffusion control), physical modelling taking both into account ("mixed-mode growth") has also been effectuated. The widely used technique of Phase Field modelling and an alternative mixed-mode approach based on Cellular Automata will be presented and compared in this paper. Whereas Phase Field modelling is applicable to a wider range of processes, the Cellular-Automata method is highly efficient and allows 3D-simulations of entire process cycles within very limited computation times. Examples of these modelling techniques applied to the development of microstructures in Dual-Phase and Quenching-&-Partitioning steels are given.
Mathematical Modelling of Hot Rolling: A Practical Tool to Improve Rolling Schedules and Steel Properties
Authors: Siciliano Fulvio
Published: July 2013

Most of the commercial metallic materials undergo at least one hot deformation stage during fabrication. Hot deformation processing leads to the production of plates, strips, rods, pipes and other shapes at lower overall cost when compared to the cold deformation/annealing route. Comprehensive study of the metallurgical phenomena during hot deformation has enormous potential application in the control of industrial rolling processes. Understanding of the microstructural and mean flow stress evolution lead to sound steel developments and innovative rolling schedules. The models predict parameters such as grain size, fractional softening (static and dynamic) and strain induced precipitation which are useful to improve rolling schedules. Effects such as incomplete softening and strain accumulation can be easily detected as well as their consequences on the final grain size and mechanical properties. In this regard, special attention must be given to steels, the most important metallic material in terms of history, present and future. In this paper, three hot rolling routes will be analyzed in order to produce high strength linepipe steels. Examples were selected on how the use of modelling during development stage can help to meet mechanical properties, mainly toughness and drop weight tear test. Firstly, it is presented a brief overview on mathematical models applied to hot rolling. Thin slab casting/direct rolling, hot strip mill and plate mill are exemplified in the present work. The development of new steel grades can greatly accelerated with the aid of modelling, which is an useful, low-cost technique.
Effect of Interfacial Tension on the Emulsification of Slag - Considerations on the CFD Modelling of Dispersion
Authors: Sulasalmi Petri , Visuri Ville Valtteri , Fabritius Timo
Published: July 2013

Top slag emulsification is a significant phenomenon in refining metallurgy. During bottom-or side-blowing, the flowing steel detaches small droplets from the top slag. The interfacial energy between liquid slag and steel is one of the most important factors affecting to emulsification. Surface energy, which can be described by interfacial tension, is the dominant property when determining slag emulsification. During chemical reactions, mass transfer between the phases decreases the interfacial tension at the slag-steel interface. The change in the interfacial tension affects the droplet formation.In this paper, the effect of interfacial tension on the emulsification was studied with Computational Fluid Dynamics (CFD) modelling. Three cases were simulated by considering a 3-phase system consisting of slag, steel and gas. A small area, where a 15 mm slag layer lies on top of the liquid steel, was simulated applying three different interfacial tensions, while keeping other properties unaltered. Gas was included to enable a free slag top-surface. The droplet diameter, size distribution and amount of droplets are in the scope of interest. It was found that the Sauter mean diameter of the slag droplets increased as the interfacial tension increased. The emulsification fraction varied between 1.621.95%.
Three Phase CFD-Simulation of CAS-OB Ladle
Authors: Kulju Timo , Ollila Seppo , Keiski Riitta L. , Muurinen Esa
Published: July 2013

In the production of steel, the CAS-OB process is used for composition adjustment, temperature control and removal of various dissolved impurities. In this work we have studied the CAS-OB process with CFD and focused on the behavior of the slag layer, which is produced on the top of molten steel. Dynamic mesh adaption has been applied to resolve the slag layer boundary in a detailed way. As a result the time dependent evolution of the slag layer is presented. The chosen approach to describe the process offers an effective and promising way to study this complex system. In the future this model will be validated against experimental data.
Hybrid Modeling of Flat Rolling Process during Hot Rolling
Authors: Chakraborty Olive , Rath Sushant
Published: July 2013

Mathematical Modeling is an effective technique for prediction of process parameters in industrial processes. Artificial Neural Network (ANN) technique has also been used to recognize a pattern in the given data by training itself. Further the trained network is used for future prediction of process parameters on the basis of the pattern recognition. The mathematical models are based on some ideal assumptions which are not valid in practical industrial conditions. Similarly high variability in industrial data makes pattern recognition difficult for ANN models and leads to high errors of prediction. In the present work, an attempt has been made to develop a hybrid model by integrating two mathematical models and ANN model for prediction of roll force during hot rolling of flat rolled steel products. The mathematical equations for roll force have been derived from the pressure distribution equation derived by Sims and Tselikov. A feed-forward network with back-propagation algorithm has been selected for ANN. All the three methods have been converted into computer code using Visual Basic.Net programming language. The hybrid model has been trained with about 2500 hot rolled steel coil data collected from Bokaro Steel Plant and Rourkela Steel Plant consisting of three different steel grades. The hybrid model has been validated with measured data of about 1000 coils. Combinations of ANN network in hybrid model having different number of hidden neurons and learning rate have been formulated, trained and validated. The final hybrid model has been selected from these combinations which has maximum accuracy. Also Multi-variable optimization technique can be used to find out the values for various input conditions which affect the flow stress and the roll force, minimizing the Root Mean Square Error. When comparing the root mean square error (RMSE) of model, it has been found that the RMSE of hybrid model is about 25% less than that of Mathematical Model.
Die Stress Optimization Using Finite Element and Taguchi Method
Authors: Ohdar Rajkumar , Equbal Md Israr , Kumar Vinod
Published: July 2013

In this study, finite element simulation and the Taguchi method are employed to optimize the die stress in hot closed die forging process. Investigations are carried out for forging of automotive spring saddle by including all realistic process parameters. The research involved analyzing the effects of flash thickness, billet temperature, die temperature and friction coefficient on effective die stress by means of computer simulation. To obtain the result the forging process was modeled in CATIA V5, 3D Solid Modeling Software, simulated in DEFORMTM 3D Software, and statistically setup and examined using Taguchis orthogonal array. Analysis of variance (ANOVA) is employed to determine significant parameters.
Machining Profiling of the Working Rolls as a Way to Control Cross-Section of the Rolled Steel
Authors: Astakhov Aleksandr A. , Dunaev Dmitriy N. , Mazur Igor
Published: July 2013

ncrease of requirements to quality of the flat-rolled steel causes the appearance of new methods and improvement of the well-known approaches to improving the geometry of thin-gage rolled steels. On modern rolling mills, control and management of the strips cross-section is carried out by a profile and flatness control system (PFC). The main channel of the influence of such systems on the geometric parameters of the rolled steel is the axial shifting of S-shaped working rolls in CVC (Continuous Variable Crown) mills. The performance of the PFC is determined by the correct choice of the initial (machining) profile of the working rolls. The paper discusses the way to improve the methodology of grinding S-shaped working rolls by taking into account the stresses, arising in the zone of contact strip with rolls, the elastic deformation of roll system, thermal deformations, arising from the contact with the hot strip and wear of the working layer of the rolls during the campaign. The developed mathematical model of stress-deformed state allows you to determine the places with the highest stresses in the zone of contact strip with working rolls and adjust the initial profile of the rolls to ensure uniformity of extracts of a strip in width with regard to shifting rolls in the axial direction. The mathematical model of the thermal condition of S-shaped rolls, which allows to predict the change of the rolls thermal profile, gives the possibility to create the algorithm for the grinding of the working rolls in hot condition and increase the accuracy of performance of their machining profile.