bluuebunny/crossref_metadata_2025 huggingface dataset:
Novel Thermo Thickening Smart Gel with Interpenetrating Polymer and Surfactant Network
Authors: Yang Jiang , Zhou Yi Ning , Lu Yong Jun , Cui Wei Xiang , Qiu Xiao Hui , Guan Bao Shan , Ding Yun Hong
Published: June 2014

A novel smart gel based on interpenetrating network of anionic polymer and surfactant was investigated. A supramolecular assembly structured gel is formed by associating polymer side chain with wormlike micelle of surfactant. The physical interaction of val der vaal and hydrogen bonding force between surfactant and polymer gives a strong viscoelastic gel at evaluated temperature. The viscoelastic properties and gel structure were characterized by dynamic rheometer and cryo-TEM. The polymer and VES complex gel is highly elastic, which elastic moduli G’ is higher than loss moduli G’’ at low angular frequency, 0.1 rad/s, in high temperature. The total concentration of surfactant and polymer is low which is economically to use in industries.
Influence of Injection Conditions on the Mechanical Property of MWCNTs/ PC Nanocomposites
Authors: Wang Li Jun , Qiu Jian Hui , Sakai Eiichi
Published: June 2014

The melting mixing was applied in the preparation of Multiwalled carbon nanotubes/Polycarbonate (MWCNTs/PC) nanocomposites. MWCNTs/PC nanocomposites with different MWCNTs contents were prepared under different injection conditions. The mechanical property of nanocomposites was comparatively investigated. The results demonstrated that: the tensile property of the nanocomposites was slightly improved by MWCNTs content increasing; but as the MWCNTs contents went on to increase to 10wt%, the tensile strength and bending strength were obviously decreased about 35% and 47%, respectively, but the impact strength and hardness were increased. The center hardness of MWCNTs/PC nanocomposites was greater than the surface hardness. Besides, the changes on the mechanical properties of the nanocomposites were studies by changing the injection conditions. By Scanning Electron Microscopy (SEM) observation, the microstructure and morphology of nanocomposites were analyzed, revealing that the center of the nanocomposite distributed more MWNTs, and the injection conditions would affect the MWNTs’ dispersion in the matrix and the interfacial interaction between MWCNTs and PC.
Nanomechanical Properties of Core-Shell Structured Ni@NiO Nanoparticles Reinforced Epoxy Nanocomposites
Authors: Wang Huai Yuan , Yan Lei , Zhu Yan Ji , Song Hua , Zhu Jia Hua
Published: June 2014

Epoxy resin (EP) nanocomposites reinforced with different contents of core-shell structured Ni@NiO nanoparticles (NPs) were fabricated by using a surface wetting method. The nanoindentation and nanoscratch properties of Ni@NiO/EP nanocomposites were comparatively studied based on nanoindentation technique. Results revealed that 5 wt.% content of Ni@NiO NPs was the optimal concentration for Ni@NiO/EP composites to obtain the best improvement of nanomechanical properties. In comparison with pristine EP, the highest enhancements of hardness and elastic modulus of 5 wt.% Ni@NiO/EP nanocomposites were increased by 37.8% and 16.3%, respectively.
Costs Modelling Applied to Activities of Integrated Management
Authors: González Pedraza Rosario , Lambán Castillo Pilar
Published: June 2014

Integration of the main formal management systems complying ISO 9001, ISO 14001, OSHAS 18001, UNE 166002 and SGE 21 results in the reduction of their implementation and maintenance costs. This paper proposes a cost control model applied to an integrated management system to calculate the costs of implementation and omissions of its activities and thus can be used as a support tool for decision making by management.
Processes Risk Management and Continuity Assurance
Authors: Karkoszka Tatiana
Published: June 2014

Unstable technological and organisational conditions, in which nowadays organisations function, create a formation of new kinds of risk in their activity. In this scope the necessity of risk management should be noticed. It should allow for risk minimisation or elimination, finally resulting in processes’ continuity assurance. Risk management - connected with all processes in the organisation - must be realised as the system solution and undergo the improvement by the assessment, monitoring, measurement and analyses of risk. The suggested methodology of identification, analyses, assessment and acceptability evaluation determines the manner of risk undertaking. In accordance with the proposed procedure it can have character of operational control or system risk monitoring.
Towards an Integrated SOA-Based Architecture for Interoperable and Responsive Manufacturing Systems Using the ISA-95 Object Model
Authors: García-Domínguez Antonio , Marcos-Barcena Mariano , Medina-Bulo Inmaculada , Prades Lledo
Published: June 2014

Manufacturing systems need to integrate information from several sources, manage their business processes and coordinate the shop floor in order to meet the schedule at reduced costs. Holonic manufacturing has been proposed to solve these problems and has been normally implemented using agents. However, these implementations are not widely used due to their cost and limited interoperability. In this work, an approach that combines a service-oriented architecture with a multi-agent system is proposed. A list of rules is designed for deciding how to implement each holon, and is applied to the level 3 activities of ISA-95. The adoption of an enterprise service bus is suggested for decoupling service consumers and producers, and using a complex event processing engine is recommended to detect trends from the day-to-day operations of a plant. This approach is then applied to a grinded ceramic tile manufacturing plant, deriving a general architecture and an implementation of a service-based holon based on the ISA-95 object model, with a human-facing side (a website) and a machine-facing side (a Web Service).
Influence of the Friction and the Geometry in Indentation Processes
Authors: Marín Marta María , Camacho Ana M. , Sebastián Miguel Ángel
Published: June 2014

Nowadays, there are a large variety of Compressive Forming Processes with different typologies and characteristics. These processes look to manufacture workpieces in the manner more efficient and economic possible. In this paper, the indentation process is studied from the point of view of manufacturing. The influence of technological parameters such as friction and shape factor on the process has been studied. The aluminum alloy AA 6082 has been employed in this study due to its good mechanical properties, light weight and its capacity of being recycled. The Finite Element Method (FEM) has been used for the analysis. The indentation process has been studied under axisymmetric conditions. As results, the forces to carry out the indentation process and the contact pressures have been obtained. Finally, it is shown that the forces and the contact pressures do not have a high dependency on the friction between the surfaces of the punch and the workpiece. The other hand, it is displayed that the shape factor has a greater influence on the process, especially the width of the workpiece.
Teaching Mechanism Calibration to Engineering Students
Authors: Majarena Ana Cristina , Santolaria Jorge , Samper David , Aguilar Martín Juan Jose
Published: June 2014

A new practical application for teaching mechanism calibration to engineering students in senior undergraduate courses is presented in this paper. The modelling, characterization and calibration of kinematic mechanisms is performed. This application presents a special interest in kinematic mechanisms in areas such as industry and research. The application interface allows the students to carry out the different steps of the calibration procedure in an easy way, to change different variables and to analyze results. This application therefore presents an important utility as a teaching tool for the learning process and analysis of the different steps in the mechanism optimization. The application developed allows students: to design their own mechanisms and to analyze the mechanism workspace by changing some design parameters, to test accuracy and repeatability of mechanism components, to introduce the mechanism kinematic model, to evaluate the mechanism performance before calibration, to calibrate the mechanism and, finally, to analyze the improvement in the system accuracy.
Modeling of a Horizontal Coordinate Measuring Machine
Authors: Maresca Piera , Gómez Emilio , Caja Jesús , Barajas Cintia
Published: June 2014

This paper presents a new virtual environment aimed to the realization of dimensional metrology practices, in the framework of the Degree in Mechanical Engineering of Technical University of Madrid. The development of this project allows the implementation of an interactive teaching model, focused on the student, which combines master classes and virtual applications, in an environment known as DE–learning (driven e-learning). This teaching tool directs and helps students on an individual way in the dynamic and interactive practice development. In particular, this module simulates the functioning, calibration and measurements using a horizontal coordinate measuring machine (HCMM). The program interface has been developed trying to create an easy-to-use environment for the students, in order to be a first contact with the HCMM and its possible metrological applications.
Development of a Behaviour Curve for Quality Evaluation with Optoelectronic Profilometers
Authors: Cuesta Eduardo , Gonzalez-Madruga Daniel , Alvarez Braulio J. , Garcia-Dieguez Marta
Published: June 2014

This work shows an experimental procedure aimed to generate a graph with the optimal roughness parameters in order to obtain the best roughness measurements of an optoelectronic profilometer. The optimal parameters have been determined taking into account the grade of agreement between the optical roughness values and the equivalent values of traditional contact devices. The working parameters of the optoelectronic profilometer are based on computational filters which are controlled by software working with a 3D stratified colour map (chromatic fragmentation of the white light). However, these parameters substantially differ from the usual contact profilometers that work with 2D roughness profiles (cut-off, evaluation length and contact stylus radii). This work pursues to find the optical profilometer parameters, and its values, that ensure the best quality measurement for a wide range of machining process and testing several ISO roughness intervals.
The Use of Virtual Circles Gauge for a Quick Verification of Portable Measuring Arms
Authors: Gonzalez-Madruga Daniel , Cuesta Eduardo , Patiño Sanchez Héctor , Barreiro Joaquín , Martinez-Pellitero Susana
Published: June 2014

Portable Measuring Arms or Articulated Arm Coordinate Measuring Machines (AACMMs) unique characteristics bring flexibility to the inspection task and allow outside laboratory measurements. However, still a few works study their metrological behavior, uncertainty or assessment. In fact, AACMM assessment involves time consuming and expensive processes mainly inherited from CMM field. A virtual circle gauge similar to ball bars and a methodology based on international standards are proposed in order to simplify the evaluation test. Additionally, two metrological laboratories have evaluated different AACMM models with this gauge. Also, two gauge lengths (distance between circles) have be included in this study. Results have proved that virtual circle gauges are suitable to evaluate AACMMs and tested the influence of distance between virtual circles.
Uncertainty Assessment in Terrestrial Laser Scanner Measurements
Authors: Pareja T. F. , Pallero J. L. G.
Published: June 2014

Abstract. The essential purpose of this study is to develop the measurement procedures in order toevaluate the quality of the observations carried out using Terrestrial Laser Scanner (TLS) equipment.It tries, in addition, to estimate an uncertainty value that allows the users to know the reliability of theinstrument measurements. The fundamental idea of this paper is to show the metrological control'sneed, and the quality of measure's evaluation for TLS equipment and to describe a working methodology,able to be reproducible, without the essential need of having a very complex infrastructure.
Observations on the Use of Friction Factor Maps in Metal Forming
Authors: Camacho Ana Maria , Torralvo Ana Isabel , Bernal Claudio , Sevilla Lorenzo
Published: June 2014

In metal forming simulation the right definition of friction conditions at the tool-workpiece interface is a key matter, in order to obtain reliable results. The aim of the present work is the determination of friction factor maps by using the RCT with different alloys which are commonly used in the metal forming practice; and the subsequent comparison of the curves to probe if there are important deviations among different materials, which will lead to prevent the use of a unique and general map of friction curves for all materials. Results confirm the necessity of using a friction calibration map for each material. Furthermore the differences and similarities in the behaviour observed are evaluated for all materials.
Selection of the Optimal Distribution for the Upper Bound Theorem in Indentation Processes
Authors: Bermudo Carolina , Martín F. , Sevilla Lorenzo
Published: June 2014

It has been established, in previous studies, the best adaptation and solution for the implementation of the modular model, being the current choice based on the minimization of thep/2kdimensionless relation obtained for each one of the model, analyzed under the same boundary conditions and efforts. Among the different cases covered, this paper shows the study for the optimal choice of the geometric distribution of zones. The Upper Bound Theorem (UBT) by its Triangular Rigid Zones (TRZ) consideration, under modular distribution, is applied to indentation processes. To extend the application of the model, cases of different thicknesses are considered
Boundary Element Method Applied to Electroforming Process
Authors: Hernández Pedro , Socas Ayoze , Benítez Antonio , Ortega Fernando , Diaz Noelia , Marrero Ma Dolores , Monzón Mario
Published: June 2014

Elecform3DTMis a analysis and simulation tool of electroforming process, in order to facilitate design and manufacturing tasks. Electroforming is an electrolytic process that enables the manufacture of metallic parts with good mechanical properties with a high level of accuracy and reproducibility. In this process a thin metallic shell is deposited on a model part and later released from it. Distribution of deposited metal is not uniform due to current density distribution on the cathode. The results obtained with the first version of this product were very promising, and also indicated the need for a more precise analysis of electrochemical phenomena in this process.The methodology is based on the well-known potentials model of LaPlace, it enables deposited metal distribution prediction with high grade of precision, being experimentally validated with cathodic polarization curves. These boundary conditions at the electrodes serve to combine the existing electrical and chemical effects in the process. On the active surfaces of the electrodes the current density is a function of the nonlinear laws of polarization in the electrode-electrolyte interface. Analytically the resolution of these problems is totally unworkable, at least for real geometries, so it is used for solving the employment of numerical methods. The resolution has been considered using the boundary element method (BEM), because we are only interested in obtaining the solution on the surface of the cathode. Elecform3DTMis an important step beyond electroforming so far, and combined with almost all additive manufacturing 3D printer, is a cheaper alternative for high quality metallic parts manufacturing in comparison with other Rapid Manufacturing technologies.
Parametric Modeling and Compensation of Layer Manufacturing Machines
Authors: Cajal Carlos , Santolaria Jorge , Velazquez Jesus
Published: June 2014

Layer manufacturing machines are affected, the same way as traditional manufacturing processes, by systematic errors [.This lack of precision and poor dimensional accuracy can be reduced by software compensation techniques. This paper proposes a parametric error compensation technique based on pattern artifacts. This technique is verified on an Objet 350V 3D printer. To begin, these parametric techniques require the development of the machines kinematic model [. The data acquisition is performed with a CMM and a self-centering technique to measure conical sockets manufactured in the faces of pattern artifacts. After manufacturing various test patterns, with and without compensation, the achieved results are close to 80% reduction in mean error.
Contribution of Surface Finish Monitoring Signals in CNC Taper Turning
Authors: García Plaza Eustaquio , Núñez Pedro José , Rodríguez Salgado David , Cambero Rivero Inocente , Herrera Olivenza José María , Sanz-Calcedo Justo García
Published: June 2014

On-line monitoring systems eliminate the need for post-process evaluation, reduce production time and costs, and enhance automation of the process. The cutting forces, mechanical vibration and acoustic emission signals obtained using dynamometer, accelerometer, and acoustic emission sensors respectively have been extensively used to monitor several aspects of the cutting processes in automated machining operations. Notwithstanding, determining the optimum selection of on-line signals is crucial to enhancing system optimization requiring a low computational load yet effective prediction of cutting process parameters. This study assess the contribution of three types of signals for the on-line monitoring and diagnosis of the surface finish (Ra) in automated taper turning operations. Systems design were based on predictive models obtained from regression analysis and artificial neural networks, involving numerical parameters that characterize cutting force signals (Fx, Fy, Fz), mechanical vibration (ax, ay, az), and acoustic emission (EARMS).
Experimental Prediction Model for Roughness in the Turning of UNS A97075 Alloys
Authors: Trujillo F.J. , Marcos Bárcena Mariano , Sevilla L.
Published: June 2014

In this work, a study of the influence of the cutting parameters on superficial quality of dry-turned UNS A97075 test bars has been carried out. The superficial quality has been evaluated trough the arithmetical average roughness,Ra. In addition, the evolution ofRaas a function of the axial machining length has been analyzed. In order to do this, a set of machining tests has been performed under different combinations of cutting speed and feed. The experimental data have revealed a high sensitivity to change ofRawith feed, whereas this sensitivity is lower with cutting speed. On the other hand, a tendency to decreaseRawith the axial machining length has been found. Finally, an experimental prediction model forRahas been developed. This model allows predicting the value ofRaas a function of the cutting parameters and the machining time.
Effect of Calcination Temperature in the Aluminum Oxide Synthesized by Pechini Method in the Citric Acid: Metal Cation Ratio of 2:1
Authors: da Silva Mirele Costa , Lucena Hélio Lira , de Freitas Normanda Lino
Published: June 2014

Through the constant search by researchers to obtain materials with improved properties, literature has presented an annual increase in the number of articles that seek to optimize in the methodology used to prepare nanopowders. In this way, the aim of this work is to study how the calcined temperature (500, 600, 700, 800, 900, 1000, 1100 and 1200oC) changes the final properties of the alumina synthesized by Pechini method with citric acid: metallic cation ratio of 2:1. The alumina was characterized by thermal analysis, X-ray diffraction, particle size analysis and scanning electron microscopy. The results showed a total of mass loss of 61.6%. The alumina phase appear at 800°C of temperature, however the α-alumina only appear at 1100oC. The increase in the calcined temperature increases the crystallite size and the crystallinity of the alumina and the great value reached for the agglomerates diameter was 13μm for the alumina calcined at 1200oC. In relation to the morphology of the alumina, it was observed heterogeneous particles with different size and irregular geometry, with aspect of high density.
Microstructural and Colour Analysis of CuCrO2 Delafossite Obtained by Gelatin Method
Authors: Costa Asenete Frutuoso , Pimentel P.M. , Aquino F.M. , Melo D.M.A. , Melo M.A.F. , Nascimento R.M.
Published: June 2014

In this paper, CuCrO2the compound was synthesized by a route new that uses gelatin as organic precursor in order to application as ceramic pigments. The type of compound delafossite CuCrO2is known for its wide range of application, such as, thermoelectric devices, catalysts for the steam reforming process, ceramic pigments, NiO2 removal, among. The powders resulting from the synthesis process were calcined the 900°C and characterized by X-ray diffraction (XRD), infrared spectroscopy, scanning electron microscopy (SEM), UV-Visible spectroscopy and colorimetry analysis. The results showed for the CuCrO2have coloring green.
Synthesis of Gadolinium Doped Ceria Ceramic Powder by Polymeric Precursor Method (Pechini)
Authors: Martínez Jesús Mauricio González , Meneses Rodrigo Arabey Muñoz , da Silva Cosme Roberto Moreira
Published: June 2014

The synthesis by polymeric precursors method (Pechini) was used to acquire gadolinium doped ceria forming Ce0,8Gd0,2O1,9 system, reaching high stoichiometric control features and nanosized particles to form dense solid electrolyte of high ionic conductivity. The synthesis was performed with cerium and gadolinium nitrates hexahydrates, citric acid and ethylene glycol. After the pre-calcination at 250°C/18h a resin was obtained like an expanded foam (puff). According to the iterature, this fact indicates that there is a reduction of agglomerates amount in a ceramic powder. A thermogravimetry-differential thermal analysis evaluated the thermal behavior of the resin. Infrared spectroscopy determined the organic matter and nitrates presence, before and after the calcination process. The X-ray diffraction identified the fluorite-type structure and was determined the crystallite size by the Scherrer equation in 22 and 46 nm for the powder calcined respectively at 600 and 800°C. The scanning electron microscopy evaluated the agglomeration degree and the morphology of the powders.
Red Ceramic with Addition of Petroleum Coke
Authors: Xavier Gustavo de Castro , Saboya F.A.J. , Maia P.C.A. , Alexandre J. , Pedroti Leonardo Gonçalves
Published: June 2014

The aim of this work was of evaluate the introduction of petroleum coke in a red ceramic. Petroleum coke is a solid fossil fuel, petroleum derivative, of black color and granular form approximately, obtaining as a byproduct from distillation of petroleum, by the process called "cracking" heat. This product represents from 5% to 10% of the total oil in the refinery. With percentage of 0%, 0.5%, 1% and 1.5% coke added into clay were obtained ceramic pieces. After drying at 110°C and firing at 750°C, 800°C and 850°C, were obtained the mechanical and physical properties and the Weibull distribution, used to evaluate the failure probability of the material. The results show the influence of petroleum coke in ceramics, suggesting introduce 1% of coke at 800oC, when the Weibull modulus reaches value 9 (m=9).
Resistance to Synthetic Seawater Aggression of Clay Ceramics Incorporated with an Ornamental Stone Residue
Authors: Xavier Gustavo de Castro , Alexandre Jonas , de Almeida Maia Paulo César , Albuquerque Fernando Saboya , Pedroti Leonardo Gonçalves , de Azevedo Afonso Rangel Garcez , Monteiro Sergio Neves
Published: June 2014

Clay ceramic materials exposed to a marine environment may be subjected to complete degradation due to the presence of chloride salts in the air. The exposition allows the chloride to penetrate in structural pores causing an internal expansion, which eventually split the ceramic apart. In open air, the solar radiation as well as the rain and wind contribute to accelerate the degradation process. In the present work the laboratory assisted degradation of clay ceramics incorporated with a granite residue from ornamental stone processing was evaluated by synthetic seawater aggression according to standard procedure. The amount of incorporated residues, up to 10 wt % and the ceramic firing temperature, up to 900°C, were variable conditions statistically analyzed by factorial planning. Degradation wetting-drying tests were conducted up to 6 months. The results showed that the linear shrinkage of the residue-free ceramics do not stabilize during the test period for any firing temperature. By contrast, the residue-incorporated ceramics tend to stabilize after 4 months. In addition, a decrease in water absorption and flexural strength was observed in same speciemens.
Study of Ceramic Block Manufacture with the Addition of Waste from Iron Ore Extraction
Authors: Nociti Denyse Meirelles , de Campos Elson , Santos Marcelo Pereira , Bittencourt Rosa Maria , de Melo Francisco Cristóvão Lourenço
Published: June 2014

This work is intended to study the possibility of adding an amount of waste from iron mining in the ceramic mass. Clay and coal, from Vale do Paraiba, Sao Paulo, Brazil, were used in this research. These raw materials are used in the ceramic block manufacture. Clay and waste were analyzed by X-ray fluorescence and X-ray diffraction, particle size, differential thermal and thermogravimetric analysis. Liquid limit and plasticity index tests were performed in order to determine the amount of waste that which should be used in the ceramic mass. After determining the amount of waste, all samples were uniaxially pressed and sintered at 900oC. Surface roughness measurements, apparent porosity and bulk density technique and three-point flexural tests were also performed to characterize the samples. The results showed that by adding the exact amount of waste, which was determined by the essays, it is possible to manufacture solid bricks.
The Influence of Sintering Temperature on Ceramic Material with Addition of Mill Scale
Authors: Meller J.G. , Arnt A.B.C. , da Rocha M.R.
Published: June 2014

This work aims to evaluate the influence of temperature sintering of a ceramic mass to characterize the properties of a ceramic mass obtained with the addition of mill scale. This residue is consisting of iron oxides and can be used in replacing pigments used in ceramic materials. The constitution of mixture was performed after chemical characterization of the ceramic samples, with addition of 5% in weight of mill scale. Test specimens were sintered at temperatures of 900oC, 950oC and 1000oC. The samples were characterized by loss on ignition, linear shrinkage, water absorption, flexural strength by 3 points and colorimetric test. The results indicate that different firing temperatures influenced the strength and tone of the specimens tested and, allowing the application these materials as structural ceramic.
Reuse of Waste from Polish in the Production of Porcelain
Authors: Santos Patricia Ferreira , Calado Claudinei Rezende , da Silva Sidney Nicodemos , Pinheiro I.P.
Published: June 2014

The ceramics industry has been conducting numerous research studies with the objective of reducing and reusing waste to improve the quality and efficiency of the porcelain polishing process. Large amounts of residue are generated during the porcelain polishing process. Recycling this residue during the process itself reduces production costs. In this work, the residue of porcelain was characterised by thermogravimetric analysis (TGA), X-ray diffraction (XRD), X-ray fluorescence (XRF), linear retraction, water absorption, apparent density, apparent porosity and optical microscopy. Mixtures with different proportions of waste were obtained to evaluate at what proportion no loss of visual quality and structural material could be attained. Little structural or visual change was observed for samples that contained up to 2.0% porcelain residue by weight.
Phases Obtained from Heat Treatment of Mn-Co-Based Coatings Deposited by Dip Coating
Authors: Bervian A. , Korb Matias Angelis , Savaris I.D. , Ludwig G.A. , Barreto L.S. , Gauthier G. , Malfatti Célia de Fraga
Published: June 2014

Studies have been performed to improve the oxidation resistance of ferritic stainless steels at high temperatures because these materials have been proposed for the manufacture of interconnectors for solid oxide fuel cell (SOFCs) and solid oxide electrolysis cells (SOECs) operating at intermediate temperatures (IT-SOFCs). Among the coatings employed, ceramic spinel-type oxides have been the most frequently applied. In this context, Mn-Co-based coatings were deposited on ferritic stainless steel (AISI 430) in this study using a dip-coating technique. The obtained coatings were characterized with respect to their morphology by SEM, their elementary composition by EDS and their structure by XRD. It was possible to produce continuous and adherent Mn-Co-based coatings on the surface of the metallic substrates.
Processing and Properties of Soil-Cement Blocks Incorporated with Natural Grit
Authors: Alexandre Jonas , de Assis Paula e Silva Caio Lobato , de Azevedo Afonso Rangel Garcez , Xavier Gustavo de Castro , Candido Veronica Scarpini , Monteiro Sergio Neves
Published: June 2014

Soil-cement blocks are worldwide used in civil construction competing with ceramic blocks like the red clay ceramic bricks. In the southeast of Brazil, particularly in the states of Espirito Santo and Rio de Janeiro, clay ceramic blocks predominate owing to lower processing costs. The incorporation of inexpensive raw materials into soil-cement blocks could improve their margin of competition. Therefore the present work investigated the processing and properties of soil-cement blocks incorporated with a relatively high amount, 81 wt%, of natural grit in substitution for the conventionally used gravel and sand. The grit had a convenient particle size. The results of compression and water absorption tests indicated that the grit incorporated soil-cement blocks attend the norms for civil construction.
Properties of Glass-Ceramics Obtained from Crystallization of the SiO2-Al2O3-MgO-Li2O System with Addition of ZrO2
Authors: de Souza Filho Manoel Pereira , de Campos Elson , Moreira Janaina Pardi , Lopes Cristina Moniz Araujo , de Melo Francisco Cristovão Lourenço
Published: June 2014

This paper presents the study results with glass-ceramics obtained from base glass (MgO-Al2O3-SiO2-Li2O system) with addition of ZrO2as nucleating agent. The glass was melted at 1650 oC for 3 h and at a heating rate of 10 °C/min. The molten glass was poured into a graphite mold to obtain monolithic samples and also in water in order to obtain particulate material. Such material was grinded and then pressed by both uniaxial and isostatic pressing methods before being sintered. Both the monolithic and pressed samples were performed under two different conditions of heat treatment so that their nucleation and crystallization occurred. In the first one, the samples were heated to 1100 oC with a heating rate of 10 oC/min. In the second one, there was an initial heating rate of 10 oC/min up to 780 oC, which was kept for 5 minutes. After that, the samples were heated to 1100 oC at a heating rate of 1 oC/min. Microhardness analyses showed that base glass presented values around 7.0 GPa. The glass-ceramics obtained from the powder sintering showed microhardness values lower than those obtained from monolithic samples. The highest hardness values were observed in the samples which were treated with two heating rates, whose values were around 9.2 ± 0.5 GPa. Moreover, the glass-ceramics which were produced with an only heating rate, presented values around 7.1 ± 0.2 GPa, very close to those observed in the base glass.
Magnetic Study of Nanoferritas CoFe2O4 Obtained by Reaction of Combustion
Authors: Santos Polyana Tarciana Araújo , de Araújo Pascally M.A. Guerra , Costa Ana Cristina Figueiredo de Melo , Cornejo Daniel R.
Published: June 2014

The present work aims to study the magnetic properties of nanoferrita cobalt obtained by combustion reaction. The structural feature as well as the magnetic behavior when in the presence of a magnet and magnetic measurements was investigated. The resulting samples were characterized by X-ray diffraction (XRD), infrared spectroscopy (FTIR), magnetic behavior when in the presence of a magnet and magnetic measurements. The results indicated the phase single the spinel ferrite CoFe2O4, with high intensity of diffraction peaks indicating that the samples are crystalline and nanoparticle formation. The characteristic bands of spinel were observed for nanoferritas CoFe2O4. The ferrite nanoparticles were strongly attracted when in presence the magnet presenting a saturation magnetization of 58.0 emu/g, coercivity of 1.14 kOe.
Application of Design of Experiments to the Alkaline Treatment in Mordenite Zeolite: Influence on Si/Al Ratio
Authors: Macedo H.P. , de Oliveira Felipe Lívia Cristina , Silva L.B. , Garcia Laurenia M. Pereira , Medeiros R.L.B.A. , Costa T.R.
Published: June 2014

This paper presents the application of Design of Experiments (DOE) to an alkaline treatment in mordenite zeolite, in order to identify the optimum settings of the variables (temperature and concentration of NaOH) that promote greater desilication. Samples of commercial mordenite with Si / Al ratio = 9 have been treated with aqueuos NaOH solution of various concentration (0,1;0,5;1,0) and temperature (30,50,70°C). Statistical analysis was carried out based on a 22 factorial design with center point replicates. Seven experiments were executed and the data of Si/Al ratio obtained. The resulting samples were characterized by x-ray difraction (XRD) and energy dispersive x-ray (EDX), to identify the structures and crystalline phases, and to determine the percentages of silicon and aluminum, respectively. In all samples, a decrease in the Si / Al ratio was observed, keeping the crystalline structure. The treatment was most effective, especially, at high temperature and NaOH concentration (experiment 4). DOE was shown to be a powerful techinique for the study of the variables, allowing determining which variables and value ranges have more influence on response, enabling optimization.
A Study on Public Opinion of Structural Concrete Blocks Incorporated with Ornamental Stone Residue
Authors: de Azevedo Afonso Rangel Garcez , Alexandre Jonas , Xavier Gustavo de Castro , Zanelato Euzébio Barnabé , Candido Veronica Scarpini , Monteiro Sergio Neves
Published: June 2014

The municipal area of Cachoeiro de Itapemirim, state of Espirito Santo, Brazil, is a major producer of ornamental stones. The sawing process of these stones generates a considerable amount of residues, which is disposed in open air piles, contributing to pollution and landscape degradation. A current solution being investigated for these residues is their incorporation into civil construction products such as clayey ceramics, lining mortars and concrete blocks. However, this incorporation is still subjected to doubt not only by the producers in the industry but also the intermediate seller as well as the final consumer. In order to verify the degree of personal acceptance of concrete structural blocks incorporated with ornamental stone residue, a field poll was conducted by means of questionnaires for inquiring the three directly related segments. The results showed distinct degrees of acceptance, especially by the sellers who fear rejection by the consumer. The acceptance of the residue incorporated block was, in some cases, positive as long as supported by a research work conducted in R&D centers and Universities.
Incorporation of Global Blast Furnace Sludge into Clayey Ceramic
Authors: Abreu Mariana Miranda , Vernilli Fernando , Candido Veronica Scarpini , Monteiro Sergio Neves , Vieira Carlos Maurício Fontes
Published: June 2014

The blast furnace is one the main systems used in steelmaking plants operating with iron ores. In addition to the production of pig iron and slag, the blast furnace operation also generates a considerable amount of wastes such as dust usually collected in the upwards flowing gas. The dust collecting stage, without separation procedures, produces a sludge, which cannot be recycled inside the plant due to the concentration of undesirable earth alkaline metals as well as zinc. A possible solution for this so-called global blast furnace sludge (GFS) is its incorporation, outside the plant, into clayey ceramic products processed at high temperatures. Therefore, the objective of the present work was to investigate the effect of GFS incorporation, in amounts of 5 and 10 wt%, into kaolinitic clay ceramics fired at 750, 950 and 1050oC. Initially, the GFS was characterized and, after processing, incorporated into ceramics that were then tested for the water absorption, linear shrinkage and flexural strength. It was found significant improvements in the properties for GFS incorporated ceramics fired at 1050oC.
Bentonite Clays from Sossego, Paraiba, Brazil: Physical and Mineralogical Characterization
Authors: Pereira I.D.S. , Lisboa V.N.F. , Silva I.A. , Figueirêdo J.M.R. , Neves G.A. , Menezes R.R.
Published: June 2014

In the northeastern region Brazil, especially in the State of Paraíba, there is a large incidence of non-metallic minerals, among which we may highlight the bentonite clay, ball clay, smectitic clay, kaolin... limestone and mica. In past years, there has been an intense research for discovering new deposits in the State of Paraíba, thus creating expectations for widening the mineral raw production in that region. So, this work is intended to make the physical, mineralogical and technological characterization of smectitic clays from the town of Sossego, PB, Brazil. The characterization was made by means of the following techniques: granulometric analysis by laser diffraction (GA), themogravimetric and differential thermal analysis (TG and DTA), chemical analysis (EDX) and X-ray diffraction (XRD). The results evidence that the studied clays present the following mineral phases: smectitic, kaolinite and accessory minerals such as quartz, carbonates feldspars and mica.
Evaluation of Industrial Rejects of Mineral and Metallurgical Processing as Ceramic Synthetic Proppants
Authors: de Campos Vitor Polezi Pesce , Toffoli Samuel Marcio , Gouvea Douglas , Lenz e Silva Guilherme Frederico Bernardo
Published: June 2014

Hydraulic fracturing is a very important technique to increase the productivity and recovery of oil reservoirs with low pressure or high depth. The hydraulic fracturing technique is a method of well stimulation in which liquid under high pressure is pumped down a well to fracture the reservoir rock adjacent to the wellbore. Propping agents are used to keep the fractures/cracks open. They can be made from the reject of mineral extraction processes when they present specifics characteristic. The aim of this paper is the evaluation of the use of industrial rejects to the development of ceramic synthetic proppants that are resistant to chemical corrosion and high mechanical strength in aqueous acid and salt water environment. In this study, industrial rejects from nickel sulfide ore flotation (grey mud - GM), red mud (RM) from Bayer process and black mud (BM) from Caron processing of nickel was used as raw material for the production of ceramic synthetic proppants. The material processing was performed through drying, milling, pressing, sintering and characterizing raw material. Several characterization techniques such as X-ray powder diffraction (XRD), Differential Scanning Calorimetry (DSC), Scanning Electron Microscopy (SEM), high temperature dilatometry and compression strength test were performed after sintering to evaluate the technological potential of recycling these metallurgical and mineral rejects. Mechanical properties were improved after sample sintering. The results show that it is possible to manufacture ceramics of high strength and resistance to acidic/salt water environment as a result of processing minerals reject.
Modification of Sodium Bentonitic Clay Used in Zinc Ion Adsorption
Authors: de Almeida Neto Ambrósio Florêncio , Vieira Melissa Gurgel Adeodato , da Silva Meuris Gurgel Carlos
Published: June 2014

In this study, it was evaluated the potential use of commercial sodium bentonitic clay, called Fluidgel, chemically and thermally treated, as an adsorbent in the removal of zinc ions from aqueous effluents. The chemical treatment was carried out with 10 g of clay dispersed in 100 mL of acetic acid 4 %. The heat treatment was obtained by calcination at 750 °C for 24 hours in muffle. The adsorption experiments were performed in thermostatic bath system and fixed bed, both based on preliminary study of metallic cationic speciation. The kinetics of zinc ions adsorption by acid-treated clay was rapid, requiring a minimum time of 60 min to reach equilibrium. The adsorbed amount and percentage of total zinc removal, at equilibrium time, was 0.06 mmol/g and 45 %, respectively, using the acid-treated clay. There was no removal of zinc by Fluidgel calcined clay in bath system, but in fixed bed it was obtained the total amount of zinc removal of 0.11 mmol/g and 41 % of percentage of removal.
Use of Ceramic Membrane for Indigo Separation in Effluent from Textile Industry
Authors: Lima Rosa Carmo Oliveira , Lira H.L. , Neves G.A. , Silva M.C. , França K.B.
Published: June 2014

The production of fabrics is one important sectors of the national economy, especially in jeans production. During dyeing step, in the production of jeans, it is generate a large amount of wastewater rich in indigo, a strong blue dye that when released directly into the environment is responsible for several environmental impacts. The aim of this work is to study the use of microfiltration ceramic membranes for indigo separation in effluents from textile industry. Initially the ceramic membranes were characterized in relation to the pore size and tangential flux. It was produced an indigo solution whose concentration and composition similar to the effluent of textile industry. The solution was characterized and submitted to a filtration through ceramic membranes by tangential flow, by applying a pressure of 3 Bar. At the end it was verified that 99% of the indigo was retained.
Characterization of Spectrogel Organoclay Used to Adsorption of Petroleum Derivatives
Authors: Speridião D.D.C.A. , dos Santos O.A. Andreo , de Almeida Neto Ambrósio Florêncio , Vieira Melissa Gurgel Adeodato
Published: June 2014

This study performed the characterization of the commercial bentonite organoclay named Spectrogel C, showing to its affinity with some petroleum products. The surface area and pore size distribution were measured by the BET method, and presented a low area of 2.7 m3/g. The thermal stability was analyzed by the techniques of TG, DTG and DSC, which revealed a low moisture level and high content of organic salt, representing 25% of its total mass. The results of EDX showed that the clay is composed of aluminum silicates, Cl, Fe, Na and Mg. The texture was evaluated by SEM showed an irregular surface and defined particle size. XRD analysis proved that the clay belongs to smectite group is composed mainly of montmorillonite. The hydration and expansion tests showed good affinity with the organic complex and low affinity for the pure compounds. The Spectrogel organoclay presented potential to act in the removal of hydrocarbons.
Study and Characterization of Chocolate B Clay on Adsorption of Heavy Metals (Lead and Zinc) in Bath Finite System
Authors: Mota Joseane Damasceno , Cunha Rochélia Silva Souza , Freire Rodrigues Meiry Glaúcia
Published: June 2014

The clays are emerging as excellent alternative materials in the process of removing organic and inorganic contaminants, that due to it's physicochemical characteristics, it’s easy to obtain and also for low cost. The initial objective of this ( study was to characterize the clay Chocolate B by the techniques of X-ray diffraction (XRD) and cation exchange capacity (CEC). In addition, the testing of finite bath under certain conditions (pH, concentration) in order to better evaluate the efficiency of clay in the removal of heavy metals zinc and lead. It was used a factorial design 22 with addition at the central point, being evaluated the percentage removal (% Rem) and the removal capacity (qeq) by Chocolate B Clay. It was observed that the Chocolate B clay belongs to the smectites group. The results have shown promise in the removal process of the metals zinc and lead by Chocolate B clay.
Recycling of Automotive Laminated Waste Glass in Ceramic
Authors: Munhoz Antonio H. , Braunstein Faldini Sonia , de Miranda Leila F. , Masson Terezinha Jocelen , Maeda Claudio Yuji , Zandonadi Alexandre R.
Published: June 2014

Reducing the environmental impact is an important factor for the sustainability of environment. This paper discusses the characterization of white ceramic bodies with an industrial waste produced in the automotive industry. The use of laminated glass residue as a raw material of a ceramic body was endeavor to make a positive impact on the environment. The laminated safety glass was ground to promote separation of glass from poly (vinilbutiral). Then, the powdered glass was used as starting material in the ceramic mass and PVB was used to confer plasticity to the ceramic mass. The fired ceramic body was analyzed using thermal analysis (DTA and TG). The specimens were tested to obtain the flexural resistance and water absorption. The data shows that PVB addition improved mechanical properties and that the grinded glass powder reduced the water absorption and increased the mechanical strength of ceramic bodies after firing.
Use of Glass Particles from Recovered LCD Screen Components as Fillers for Polyamide-6
Authors: Massaro Natalia , Morais Douglas , Toffoli Samuel Marcio , Valera Ticiane Sanches
Published: June 2014

Glass from computers’ LCD monitor screens were recovered, ground and used as filler for Polyamide-6. The composites contained 10 wt% of glass particles. Two particle sizes were tested: glass particles smaller than 106 μm (ABNT#150 sieve) and smaller than 53 μm (ABNT#270 sieve). The filler was evaluated by loss on ignition and the composites by tensile strength and Izod impact strength. The morphology was characterized by scanning electron microscopy (SEM). The value of Young’s modulus of composites processed with glass particles smaller than 53 μm was higher than the one for PA-6. The properties of impact strength, tensile strength, and elongation of PA-6 were reduced with the addition of filler, and the composite containing glass particles smaller than 53 μm showed the lowest reduction in mechanical properties (about 6% in the tensile strength and about 48% in impact strength). The micrographs of fracture surfaces of tensile strength specimens showed weak adhesion particle/matrix and uniform distribution of the particles in the matrix, especially in the composite with finest particle sizes.
Porosity and Delamination Defect Detection in Ceramic Materials by Active Infrared Thermography and Optical Digital Microscopy
Authors: Calado Claudinei Rezende , Calado F.A.R. , Caput G. , Gomes S.C. , Andrade R.M.
Published: June 2014

This paper examines the use of active lock-in thermography and optical microscopy coupled with digital image processing as a production-time quality control tool for porcelain tile manufacturing. We demonstrate that it is possible to associate physical properties such as density, porosity and water absorption capacity with internal defects such as thermal delamination in ceramics. Defective and intact samples were subjected to active lock-in thermography and digital microscopy analysis on a workbench developed to simulate the conditions found in production lines. The images were collected and processed using morphological operators, image enhancement and thresholding to detect the presence of defects. These methods were compared with methods that analyze the physical properties of the materials to demonstrate that it is possible to detect the presence of defects.