bluuebunny/crossref_metadata_2025 huggingface dataset:
The Chopping Voltage Regulation System Based on PLC Control
Authors: Zhang Tao , Luo Yi , Gao Peng , Lin Wei Tong
Published: September 2014

For the output voltage of traditional regulators have problems of unstable and unreliability. The chopping control system based on PLC control is designed. This paper takes the PLC intelligent processor as core of the system and uses IGBT constitute chopping circuit. Voltage signal possessed by fuzzy PID export PWM wave to control IGBT opened and closed achieve voltage regulation. The experiment result shows that the system has advantages of simple circuit, rapid current control, and high level automation.
Intelligent Protection Device of Dual-Core Feeder Switch Based on DSP
Authors: Mo Xing Yang , Xu Jin Yong , Gao Peng , Hu Xiu Ying
Published: September 2014

Feeder switch of mine guarantees safe operation of underground power supply system. In order to solve the poor stability and reliability of the current mining feeder switch, the article puts forward an dual-core intelligent protection device of feed switch based on DSP. The device to TMS320C6678 as control core of measure and control module collect electrical and deal with signal analysis in the grid. The DSP make instruction of protection operation. The equipment with ATmega128 as control core of management module complete the function of setting parameters and showing results of the measurement. The experimental results show that the device movement is stability , sensitivity. The equipment is high reliability and the scheme is feasible.
Design of New Energy Vehicle Intelligent Anti-Collision System
Authors: Ruan Xian Jing
Published: September 2014

The new energy vehicle intelligence anti-collision system, is a new energy vehicle safety assist device , can timely and intuitive display the obstacles of new energy vehicles’ around, help the driver to remove the dead angle of vision and the flaw of sight, in case of emergency, intelligent control of brake. The research of this paper is that new energy vehicle intelligent anti-collision system of a kind of low cost, high precision, miniaturization and with a liquid crystal display and sound , light alarm function center on the single chip AT89S52 , the product is developed according to the principle of ultrasonic ranging, using the temperature compensation technology, power on self-checking technology and optimized hardware and software technology, sent the measured results to the liquid crystal display, in case of emergency, intelligent control of brake, improves the safety and efficiency of new energy vehicles.
A Study on the Campus Public Safety Monitoring System Based on Intelligent Vision
Authors: Zhang Xi Zhu
Published: September 2014

With the continuous development of video detection technology, the video analysis technology based on campus security has become an important part of the construction of safe campus. As the college students still are a group that has poor ability of security protection, campus security issue is closely related to the stability of society and family happiness, and has become a topic of concern to the whole society. The intelligent vision-based campus public safety monitoring system is an important means to achieve security monitoring, it can automatically analyze the video image sequence, and detect, track and identify objects in the monitoring scene without human intervention, and make high-level understanding and analysis of behaviors on this basis. Most of the existing visual monitoring systems can collect and store video data, and the real-time event detection task can automatically be generated through background analysis. Intelligent visual monitoring system should not only be used for accident investigation, but also be used to prevent potential disasters and accidents. The system is consisted of system management platform, event mining and analysis, monitoring and extraction of moving targets, forecasting and tracking targets. The paper makes an in-depth study on the application of intelligent visual detection technology on campus. Based on the intelligent visual video analysis, hidden Markov model is adopted in the paper for video event detection and analysis, motion features and shape features are taken as the observation data, and segmentation method is adopted to analyze the influence of video viewing height and angle on the detection result.
The Study of LC Three Point Oscillation Circuit Based on the Multisim Simulation Software
Authors: Cao De Yue , Zhang Yang , Zou Yi
Published: September 2014

This paper briefly introduces the function of LC three point oscillation circuit and the study of the composition and performance parameters of capacitance three point oscillation circuit, inductance three point oscillation circuit and modified capacitance three point oscillation circuit based on the Multisim simulation software.
Stress Analysis of CFRP Externally Pre-Stressed Reinforcement Continuous Beam
Authors: Wang Xin Zhong , Li Chuan Xi
Published: September 2014

An externally pre-stressed continuous box girder bridge is designed according to loading features of the continuous beam. The CFRP bars and steel strands are used to make two models for externally pre-stressed reinforcements at the supporting points. CFRP reinforcement area of Model 1 at the supporting point is 1/2 of steel strand externally pre-stressed reinforcements of model 2 at the supporting points. After the calculation, we can find that under effects of the same tension control stress and the external loads, mechanical effects of the continuous box girder bridges with CFRP bars can be equal to or better than performances of continuous box girder bridges with steel strands. They can provide references to applications of CFRP bar.
Reliability Method on Product Innovation Design
Authors: Zhang Rui
Published: September 2014

Product innovation design is challenging due to the complexity of the industrial environment, the changing needs of markets and customers, the effect of intense social competition, and the unpredictability of the future. This paper presents in a systematic analysis of reliability method on industrial product innovation design in order to illustrate what the real meaning of reliability method and how it works on the product innovation design. It also clarifies the relationship between reliability method and product innovation design, reflecting the function of reliability method on each work stage. It is concluded that a suitable thinking mode should be applied on the corresponding design, and it will enhance the effectiveness of innovative product design in general.
Numerical Analysis of Sheet Metal Forming Limit for Local Forming
Authors: Yang Rui , Liu Yu , Wen Peng Fei , Zhang Jun Hua
Published: September 2014

Generally, the forming limit diagram is widely applied to predict the sheet necking and fracture in the conventional sheet forming process. In recent years, the fact that the forming limit is much higher using Incremental sheet forming (ISF) than that obtained in conventional sheet forming, has become a research hotspot in forming mechanism of local forming process. In this paper, the geometrical imperfection in the thickness was presumed to represent local weakening zone and the BAMMAN_DAMAGE material model which using void to describe non homogenization caused by geometric imperfection, were used respectively to investigate the effect of geometry imperfection on the sheet forming limit. Based on the W.C. Emmens’ experiment, the reason and mechanism of enhancement of forming limit during incremental forming was studied through the numerical simulation method. And the variations of stress and strain during the forming process were also studied.
Analysis of the Quality of the Weld Metal Obtained with Alloyed Flux-Cored Wire
Authors: Bajic Nikola , Rakin Marko , Veljić Darko , Mrdak Mihailo , Stojadinovic Slobodan , Pekez Jasmina
Published: September 2014

Abstract. The main aim of this paper is to assess the quality of newly produced, alloyed flux-cored wire with increased thickness of the steel cover compared to traditional according to AWS A5.29 standard, alloyed with Ni and Mo, and designed for welding of fine-grained HSLA steel. Flux-cored wire was produced on a pilot production line that allows calibration of steel band of higher thickness and production of flux-cored wire. Quality assessment of the alloyed flux-cored wire was based on the analysis of the results of tests of mechanical properties and microstructure mainly of the weld metal. Variation of chemical composition and microstructure were analyzed along weld metal (for each welding pass) and heat affected zone (HAZ) using SEM and EDS. Based on the results of the quality assessment of flux-cored wire, the conclusions about the feasibility of industrial application of selected metallurgical grade of flux-cored wire designed for welding of fine-grain HSLA steel were presented.
Experimental Study of Adhesion between FRCM and Masonry Support
Authors: Corinaldesi Valeria , Donnini Jacopo , Mazzoni Giorgia
Published: September 2014

The use of composites with cement matrix seems to acquire an increasing interest in applications to masonry structures, due to their low impact, and a deeper understanding of the mechanical interaction between support and reinforcement is certainly necessary. The effectiveness of these interventions strongly depends on the bond between strengthening material and masonry, on the fibers/matrix interface, as well as on the mechanical properties of the masonry substrate [1]. In this work the attention was focused on the possible improvement of the bond between FRCM and masonry by means of an inorganic primer, which can be spread on the ceramic support before the application of FRCM reinforcement. Two different kinds of brick were tested, in order to simulate more or less porous masonry supports. Results obtained showed that, independently on the kind of brick used (more or less porous) the presence of an inorganic primer always improves bond between masonry support and the cementitiuos matrix of FRCM. In fact, the cementitous matrix of FRCM has been studied and optimized in order to guarantee the best fibers/matrix interface, while it is not necessarily the best option for improving the adhesion with the masonry support. In particular, very effective seems to be the use of very fine inorganic particles (at nanometric scale), which proved to be able to assure the best results in terms of bond strength. Also the fresh consistence of the primer seemed to influence the final result.
Rheology of Grouts for Masonry Injection
Authors: Baltazar Luis G. , Henriques Fernando M.A.
Published: September 2014

Grout injection technique applied in a multiple leaf masonry walls aims at increasing the compactness of the masonry and, therefore, improving their monolithic behaviour by bonding the separated segments together without compromising the architectural value of the masonry building. The success of the injection grouts depends mainly on their rheological properties. This means that the flow properties of fresh grouts are as important as their properties in the hardened state, since they govern the ability of the grout to flow and fill the voids within masonry. In practice, the variability of voids within masonry requires ability to fine tune the rheological properties of the grout, in order to optimal fill all voids with grout. So, models were developed with the main purpose of predict and control the rheological properties of grouts just performing simple flow tests traditionally used in the field. It is well known that flow tests commonly performed (such as Marsh cone and slump test), which try to describe the workability of cementitious materials, only give a qualitative result that can not be expressed in physical rheological units. However, the proposed models allow calculating a physical parameter (e.g. viscosity) instead of an empirical one (e.g. fluidity). This research shows the effect of grout design variables on the properties of natural hydraulic lime grouts based on the correlation between rheometry measurements and simple flow tests. Furthermore, the proposed models can be very useful to smooth the grout design methodology, since these models enable the prediction of rheological properties of the grout without the need for expensive and complex equipment, such as rheometers or viscometers.
Freeze-Thaw Durability of PVA Fiber Reinforced Mortars Representing In Situ Conditions
Authors: Sorensen Andrew D. , White Trevor
Published: September 2014

Polyvinyl Alcohol (PVA) fiber reinforced mortars (FRM) have been shown to increase the ductility of unreinforced masonry walls thus improving their out-of-plane flexural capacities. As these mortars become increasingly popular, their durability under freeze-thaw conditions requires further scrutiny. Previously, the durability of PVA FRM has been evaluated as mortar components only and not in combination with masonry units. The freeze-thaw testing of masonry mortars requires a complex analysis to duplicate in-situ conditions. Accelerated testing conditions are desired to represent the weathering that a structure would endure over time. This is done by simulating an aggressive weathering pattern on a test specimen in order for the analysis of the durability of the mortar and brick to be obtained within a timely manner. Currently, the standard freeze-thaw durability testing method for cementitious materials utilized in the United States of America, ASTM C666/C666M-03, is characterized by two methods: rapid freezing in water and thawing in water; and rapid freezing in air and thawing in water. This testing method provides a durability rating for specimens created and contained within a laboratory, but does not accurately represent all of the environmental factors that influence the durability of a mortar/brick structure. In this study, in order to replicate in-situ conditions, PVA FRM test specimens are constructed and subjected to freezing in water on only one side and are enclosed in a plastic bag to remedy the effect of the dry, frozen air reducing the moisture content of the mortar. Furthermore, the test specimens are frozen and thawed in a controlled environmental chamber where the relative humidity is controlled to prevent moisture change within the specimen. This enables rapid thawing of the specimen while controlling the relative humidity to better represent the in situ characteristics of masonry structures. The specimens are then subjected to 300 freeze-thaw cycles and evaluated to determine their degradation over that time. Results of the testing show limited reduction in material volume and weight of the PVA FRM compared to control samples that do not include PVA fibers.
Mechanical and Mineralogical Characterization of Mortar in Masonry Buildings Damaged by the 20-29th May Earthquake in Emilia
Authors: Galli Elisa , Savoia Marco , Colla Camilla , Ferretti Daniele
Published: September 2014

The aim of the work is to characterize mechanical and chemical properties of the mortar, and thus the masonry, of historical buildings damaged by the Emilia May 20-29th 2012 earthquakes. The attention was focused on historical strategic buildings, located in Modena district. The experimental campaign here reported was carried out for each building through four steps: first, a mechanical characterization of masonry was performed in situ using non-destructive and semi-destructive methods (step 1); then, some materials were collected in order to obtain standard specimens of mortar joint and brick (step 2). In laboratory, those samples were properly prepared for testing (step 3) with compression and flexural test setups; finally, a limited number of those mortar samples were tested in order to obtain their chemical properties (step 4). The in-situ and laboratory test results were separately elaborated for mortar and brick, to characterize the single masonry components. The results were then used to estimate the characteristic masonry parameters. Criteria to obtain the masonry behavior were reviewed in order to give the average masonry parameters. The characteristic and average values of compression strength were compared with ranges provided in the codes for the same masonry typology.
Optimal FRP Reinforcement of Masonry Walls under In- and Out-of-Plane Loads
Authors: Bruggi Matteo , Milani Gabriele , Taliercio Alberto
Published: September 2014

The problem of finding the optimal layout of FRP strips to effectively retrofit masonry walls undergoing transverse loads is dealt with, taking the presence of permanent vertical loads into account. An innovative topology optimization approach is proposed to define the minimum amount of reinforcement that keeps the stress within a given strength domain throughout the wall. The macroscopic strength properties of masonry are defined by means of a simplified limit analysis approach based on homogenization theory. The capabilities of the proposed procedure are illustrated through applications on a windowed panel subjected to out-of-plane actions and vertical loads.
Experimental Study of the Bond of FRP Applied to Natural Stones and Masonry Prisms
Authors: Panizza Matteo , Garbin Enrico , Valluzzi Maria Rosa , Modena Claudio
Published: September 2014

Compared to more traditional techniques, the application of Externally Bonded-Fibre Reinforced Polymers (EB-FRP) represents a viable alternative for the strengthening of masonry structures, also in case of Cultural Heritage buildings where strict requirements need to be met, aimed at minimizing the impact of the intervention. Since the FRP-to-masonry bond behaviour strongly affects design and effectiveness of such interventions, several investigations have been carried out in recent years to study this phenomenon, generally based on the longer experience developed for concrete substrates. Mortar joints, which are geometrical and mechanical discontinuities, distinguish and characterize masonry substrates from concrete ones, and therefore deserve a special attention as far as their role in the bond behaviour is not clarified yet. This paper, aimed at giving a contribution also from a methodological point of view, presents the main experimental results of shear tests carried out on glass composites (GFRP) applied to natural calcareous stones (pietra leccese), to lime mortar blocks and to masonry prisms made by coupling stones and lime mortar. Overall 22 shear tests were performed, keeping a bonded length of 200 mm for stones and mortar specimens while it was changed from 65 mm (corresponding to one stone and one mortar joint) to 195 mm (three stones and three mortar joints) in the case of masonry prisms. The effect of the FRP end anchorage on the test development was investigated as well, and results of the experimental tests are herein discussed in detail.
FRCM - Strenghtening of Masonry Vaults: The “Duomo Di Colorno” and “Braidense Library” Cases in Italy
Authors: Jurina Lorenzo , Mantegazza Giovanni , Radaelli Edoardo Oliviero
Published: September 2014

In the last decade a re-discovering of the construction techniques and materials belonging to ancient buildings and heritage has grown up.Professionals and researchers have made a strong effort to understand resisting mechanisms in masonry buildings, trying to evaluate the safety factor in presence of vertical and horizontal seismic loads. As a consequence, innovative techniques and materials, as the FRCM, have been introduced to prevent local and global collapse mechanism, increasing the safety of the overall structure.The special cases of “Duomo of Colorno” and the “Braidense Library”, in Italy, are here presented.The XVIII century masonry vaults of the Duomo widely suffered due to a seismic event occurred in 2012 and a relevant crack pattern appeared.A similar situation occurred for the barrel vault of the Braidense Library due to settlement of foundations.In both cases, in order to restore the global resistance of the building, some consolidation interventions have been proposed.One of those is represented by a FRCM net applied on the upper side of the vaults. The system makes use of a carbon bi-directional fiber net inserted in an inorganic pozzolanic matrix, fully compatible with the ancient masonry support.A numerical non-linear analysis of the cathedral and of the barrel vault of the Braidense Library has demonstrated an increment up to 25% in the value of the horizontal loads that cause the formation of the first cracks, if compared with the non-consolidated situation.Furthermore, besides this passive fiber intervention, an innovative active technique called “RAM – Reinforced Arch Method” was applied on the vaults of the Duomo. The use of post-tensioned steel cables, added to the FRCM net, led to a strong increase of the horizontal collapse load.Carbon fibers are able to induce a strong increase in the resistance of the masonry under the tensile stresses caused by seismic loads, avoiding the formation of cracks or plastic hinges.Several tests have been performed on FRCM, according to Standards.In tensile and lap-tensile strength tests, the stress-strain behavior of C-FRCM control coupon specimens is bi-linear as expected. The initial branch of the curve corresponds to the un-cracked specimen, followed by a second branch with a reduced slope, corresponding to the crack specimen.The primary failure mode of the C-FRCM coupon specimens was slippage of the fibers after multiple cracking throughout the length of the specimen, perpendicular to the direction of the load, secondary de-bonding failure mode located at the tab ends was observed in some cases.Furthermore, all tensile and lap-tensile strength coupon tests passed the conditions of acceptance as per the requirements regarding environmental exposure to Freezing and Thawing, and Aging.
Laser Surface Treatment of SAE 4340 and 300M Steels
Authors: Abdalla Antonio Jorge , de Vasconcelos G. , Portela A.G. , Cardoso A.S.M. , Baptista Carlos Antonio Reis Pereira
Published: September 2014

The 300M steel has emerged from the high strength SAE 4340 steel, which had been developed in order to obtain increased toughness and weldability in applications requiring better mechanical properties; some minor changes in the alloy elements were introduced: addition of vanadium, and raise in the silicon content. The laser surface hardening is a process in which the steel surface is heated below the melting point, in order to produce solid state phase transformations whithout changing the bulk. This work has evaluated which would be the best parameters for the laser carburizing heat treatment using a low power (50W) CO2 laser, comparing and contrasting the resulting microstructure and hardness of both steels. The following CO2 laser parameters were varied: speed, resolution and number of passes; power was kept constant. Carbon black was used as coating. After the surface laser treatment, the samples were cooled in air and the formation of a hardened layer and heat affected zone in both materials was observed. Samples were prepared for metallographic analysis, followed by optical and scanning electron microscopy observation. Layers presented a Vickers hardness value higher than the base metal and the hardened layer had a higher hardness value compared to the heat affect zone. The formation of martensite in the heat affected zone in both steels was observed, although not to the full extension, making this a multiphasic zone.
Influence of Aging Time on the Tensile Strenght of a Duplex Stainless Steel
Authors: Machado G.S. , Melo M.L.N.M. , Rodrigues C.A.
Published: September 2014

This article was aimed at studying the influence of different aging times during the precipitation phase of the UNS S31803 (SAF 2205) duplex steel. To do so, all the test specimens were solution heat treated at 1050oC for 1 hour and quenched in water. After this step, the samples were aged at 850°C for periods of 10, 60 and 600 minutes and cooled in water. The aging heat treatments (TT) were performed in order to precipitate the sigma phase. Samples were subjected to microhardness and tensile tests so that the influence of the microstructural changes over the mechanical properties of the steel was assessed. Based on the microhardness and tensile test data, it was possible to verify a significant change over the mechanical properties of the UNS S31803 steel.
Microstructural Characterization and Evaluation of Mechanical Properties of Steel with Different Biphasic Microstructures Obtained from LNE 500 Steel
Authors: Nogueira Ottoboni Dias Alexandre , Baldissera Márcia Regina , Carvalho Rossi Eduardo , Coelho Gilberto Carvalho , Paula Andersan dos Santos , Melo Mírian de Lourdes Noronha Motta , Rodrigues Geovani
Published: September 2014

In this work was carried out the microstructural characterization and evaluation of mechanical properties of steel with different microstructures. The intercritical region and the existing phases in function of temperature were determined using the THERMOCALC software. The samples of steel were quenched at different temperatures to obtain differents microstructures consisting of ferrite, pearlite and martensite. The microstructural characterization of the samples was performed by qualitative and quantitative metallography. The determination of volume was performed with the "Image J" software. The mechanical properties were determined by uniaxial stress test, which determined the parameters: yield strength, tensile strength, breaking point and total elongation.
The Influence of Different Microstructures to Fracture Toughness and Hardness of Quenched LNE 380 Steel at Different Temperatures
Authors: Nogueira Ottoboni Dias Alexandre , Baldissera Márcia Regina , Coelho Gilberto Carvalho , Oshiro Alfredo Yassuo , Carvalho Rossi Eduardo , Paula Andersan dos Santos , Rodrigues Geovani
Published: September 2014

In this work it was analyzed the evolution of mechanical properties of Dual-Phase steel as a function of volume fractions of ferrite and martensite, obtained from steel type LNE 380. The intercritical region and the existing phases in function of temperature were determined using the THERMOCALC software. The samples of steel were quenched at different temperatures to obtain differents microstructures consisting of ferrite, pearlite and martensite. The microstructural characterization of the samples was performed by qualitative and quantitative metallography. The mechanical properties were determined by hardness and impact tests. It was concluded that the volume fraction of ferrite and martensite calculated experimentally agrees with the simulation and the variation of these fractions affects significantly the hardness of the steel, but does not significantly affect the results of fracture toughness.
Utilization of Color Metallography in Characterization of a Modified SAE 4118H Steel Submitted to Isothermal Treatments
Authors: Vurobi Selauco , Ferreira de Andrade Thiago , Cintho Osvaldo Mitsuyuki
Published: September 2014

A modified SAE 4118H steel was subjected to isothermal treatments between 700 °C and 400 oC every 50 °C range, with the intention of evaluating the decomposition of austenite at constant temperature. It was varied time of stay in the isothermal treatment between 15 and 28800 seconds depending on the treatment temperature. After each isothermal treatment and standard metallographic preparation, the samples were etched with color metallography reagents for revealing the microstructure obtained. At temperatures of 700oC to 550°C the steel showed microstructure composed of ferrite and pearlite. Between 500oC and 400°C bainitic microstructure was quickly formed. The reduction of treatment temperature provided finer microstructures, which increased the hardness of steel. With the use of color metallography reagents, excellent contrast for determining the volume fraction of microstructural constituents formed isothermally was obtained, helping the study of isothermal decomposition of austenite.
Feasibility Study of the Properties of Clay Chocobofe Removal of Lead in Synthetic Wastewater
Authors: Vanderley do Nascimento Silva José , Costa de Oliveira Guilherme , Rodrigues Meiry Gláucia Freire
Published: September 2014

As minimization process control pollution by heavy metals, adsorption can play an important environmental role. Therefore, many adsorbents can be used as effective alternatives. This work presents a study that aims to evaluate the removal of lead in liquid effluent through adsorption process using a finite bath system and with the adsorbent clay Chocobofe. The clay in its natural form was characterized by the techniques of X-Ray Diffraction (XRD), Cation Exchange Capacity (CEC), Chemical Analysis by X-Ray Spectrometry by Energy Dispersive (EDX), moreover, the natural clay was subjected to test adsorption capacity to analyze the behavior the same in certain organic solvents. Was performed to assess the effectiveness of the natural clay in the process of removal of Pb2+ present in solutions based on a factorial design 23 + 3 replicates at the central point, with the analysis variables solution pH (3.0, 4.0 and 5.0) and the initial concentration of lead (10, 30 and 50 ppm). The studies showed this material as promising in the removal of Pb2+ ions in synthetic wastewater and that the adsorption capacity showed that the organic solvents tested.
Nitinol Alloys - Study of Physical and Chemical Application as Biomaterials
Authors: Rabello Isabel Portela , Catão Carmem Dolores de Sá , Rabello Germana Portela , Fook Marcus Vinícius Lia
Published: September 2014

The Nitinol is a term which represents the family of nickel and titanium alloys. With the discovery of the extraordinary biocompatibility of these alloys, their implementation has been emphasized in the medical devices and in general dentistry. The characteristics which make these alloys are of interest its superelasticity, shape memory effect and excellent biocompatibility, the latter two characteristics particularly interesting due to the fact that these materials confer the ability to self-expansion or contraction and not presenting rejection the organism. Thus, this study aims to evaluate three NiTi alloys compositions, being one rich in titanium, other poor and the last equiatomic, through tests of physical characterization and surface tension, after different heat treatments. After the results interpretation, it can be seen that the lower percentages by weight of nickel in their products from corrosion was the Nitinol rich in titanium subjected to heat treatment for 24 hours in the oven. Moreover, the same composition present the smallest angle in the test of surface tension.
Recycling of Steel AISI 52100 Gotten by the Route of Powder Metallurgy
Authors: Diogo Wellington S. , de Souza Dalton G.B. , Rodrigues Lourenço Rayana F. , Noronha Melo M.L.M. , Cardoso Kátia R. , Silva Gilbert
Published: September 2014

The AISI 52100 steel is a material widely used in the industry due to its high fatigue resistance, dimensional stability, high hardness and wear resistance. This steel is used for production of ball bearings, stamping tools, etc. In case of production of ball bearings and its track this material is spherodized because, due to its high content of carbon, about 1%, it has high mechanical strength making it impossible to cold forming. To obtain a wear resistant surface, after forming, this material is hardened and tempered. Normally to obtain the AISI 52100 steel, arc electric melting furnace is used. This work aims the reuse of AISI 52100 steel by powder metallurgy route, starting from the machined chips using high energy mill (planetary) to obtain the powder. Then, the powder was uniaxially pressed into a press with a load of 4 tons, to form the specimen, later on pressed in an isostatic press at a pressure of 300MPa to obtain a better densification. To analyze the powder morphology and the phases obtained after sintering, was used a scanning electron microscope and X-ray diffraction to calculate the crystallite size. It was verified that with more than 10 hours of grinding, the crystallite size does not change significantly, the particles gained rounded shapes with a size distribution between 30 and 5μm. The microstructure obtained by the two routes was nearly identical after sintering.
Evaluation of the Terms of Use of Recycled Polymer Packaging Co-Extruded
Authors: Meira Roberta Costa , Leal Rita de Cássia A. , Fook Marcus Vinicius L. , Nascimento Imarally V.S.R
Published: September 2014

Waste recycling has been stepped up around the world to enhance the quality of the recycled product and provide greater efficiency in the production system. The increasing use of polymers has led to increasingly multiple uses of these materials due to their high degradation time. The polyethylene used in plastic co-extruded with the use of ethylene vinyl alcohol (EVOH) has been a major advantage in prolonging the useful cycle of the final product. Thus the technique of co-extrusion has become very attractive in the packaging industry because it enables the design of multi-layer structures. Thus, this work aims at assessing the conditions of use of recycled material in packaging for co-extruded with application properties of a biomaterial. The packages used in this study are composed percentages of high density polyethylene (HDPE) recycled, virgin polyethylene and gas barrier (EVOH), where they were subjected to 50 ° C in an oven stabilized at room temperature as well as the approximately 23 ° C, conditioned in the laboratory. The packages were characterized by spectroscopy techniques in the Region of Fourier Transform Infrared (FTIR), Surface Tension and optical microscopy (OM). With the technique, FTIR was possible to verify the presence of characteristic bands of polyethylene. As for the measures surface tension was possible to observe an increase in the wettability of containers subjected to high temperature. It was also possible to see through the optical microscope the difference of packaging is compounded by the EVOH. The results presented so far do not suggest an indication of the occurrence of rust on packaging, allowing an indication of use.
Management Model PDCA 90-10 Applied to Open Pit Mine Operations: Practical Example - Phosphate Mine at Araxá, MG - Brazil
Authors: Agra Richardson , Petta Afonso , Paulino Jonas , de Tomi Giorgio
Published: September 2014

The recent researches main focus in planning and operational mine management is the automation and technology implementation to support the decisions-making. In this context, practical experiences shows that big mining companies invests substantial quantities of resources on the purchase and implementation of software packs to manage their mine operations. These actions itself, generally doesn ́t ensure the expected results. This paper presents a study related to mining operations management with a successful application example at a phosphate mine located at Araxá, State of Minas Gerais, Brazil. To this, it was applied a so-called Model PDCA 90-10 of planning and operational mine management. This proposal complements the state-of-the-art in technology and TI for the integration between planning and mine operation. In the end, are presented conclusions and discussions related to the implementation viability of this management model in mining chain of processes.
Tensile Strength of Polyester Composites Reinforced with Thinner Buriti Fibers
Authors: Monteiro Sergio Neves , Margem Frederico Muylaert , Altoé Giulio Rodrigues , Loiola Rômulo Leite , Picanço Oliveira Michel
Published: September 2014

The environmental concern is creating pressure for the substitution of energy intensive synthetic materials for natural and sustainable ones. Compared to synthetic fibers, natural fibers have shown advantages in technical aspects such as flexibility and toughness. So there is today a growing worldwide interest in the use of natural fibers. Buriti fiber extracted from the petiole of buriti palm tree (Mauritia flexuosa), presents some significant characteristic, but until now only few studies on buriti fiber were performed. This work aims to study the tensile strength of polyester composites reinforced with buriti fibers. This study was performed in relatively thinner fibers with diameters between 0.1 and 0.4 mm. Those fibers were incorporated into the polyester matrix with volume fraction from 0 to 30%. The fiber diameters were measured by a profile projector. After fracture the specimens were analyzed by scanning electron microscope (SEM). The results showed a sensible improvement in the mechanical properties. The SEM observation revealed the mechanism for this improvement.
Design of a Ceramic Slip for Electrical Porcelain Insulators, Using Clay Dispersed in a Ball Mill
Authors: González Adriana S. , Valera Ticiane Sanches , Toffoli Samuel Marcio
Published: September 2014

An electrical insulator is a piece or structure of an insulating material, which aims to rigidly or flexibly support electrical conductors or equipments, insulating them of the ground [1]. The insulators have distinct styles or types, offering a wide choice of components for overhead distribution design. The first and oldest series is the standard line post insulator for upright mounting on crossarms or structures [2]. An outline of the design can be seen in the Figure 1. These components have an integral head manufactured in porcelain for tie top attachment, and a base cemented on the lower end, for stud mounting to a flat surface.
Synthesis of Alpha Alumina Using Microwave Energy
Authors: Cartaxo Juliana Melo , Galdino M.N. , Campos Liszandra Fernanda Araújo , Ferreira H.S. , Kiminami R.H.G.A. , Menezes R.R. , Neves Gelmires Araújo
Published: September 2014

This work investigated the synthesis of α-alumina using dissolution and re-precipitation of aluminum nitrate and microwave heating. The synthesized powders were characterized by X-ray diffraction, thermal analysis (TGA and DTA) and surface are by BET. The dissolution process was carried out using acid solution and heat treatment. Results depicted the efficiency of the process to accelerating the synthesis of alpha alumina. The results showed that the powders have the microwave structure of α-alumina with specific areas ranging between 3 and 15m2/g and pore diameters between 190 to 485nm.
Comparison of Firing of the a Mass for Ceramic Tiles in Laboratory and Industrial Furnace
Authors: Soares Roberto Arruda Lima , Castro J.R. de S.
Published: September 2014

The present study aims to examine the differences obtained in the technological properties of a ceramic formulation for tile after firing in two different environments, laboratory furnace and industrial furnace. For this, the ceramic formulation used in the production of semi-porous ceramic tile was characterized. Chemical, mineralogical and thermal analyses in the ceramic formulation were performed. The specimens were obtained by compacting and fired at maximum temperature of 1140 o C in laboratory and industrial furnaces. The technological tests performed were linear shrinkage, water absorption, bulk density and mechanical strength. Microstructure was assessed through X-ray diffraction analysis and scanning electron microscopy. The results showed that the different furnaces provided significant differences in the specimens analyzed such as higher mechanical strength and lower water absorption in samples fired in laboratory furnace, for example.
Montmorillonite Silver Nanoparticles for Applications in Polymeric Materials
Authors: Morita Reinaldo Yoshio , Schnitzler Mariane , Wohnrath Karen , Garcia Jarem , Barbosa Ronilson Vasconcelos , Iodice Bianca , Kloss Juliana Regina
Published: September 2014

This work presents the preparation of silver nanoparticles (AgNPs) with montmorillonite to produce a nanomaterial with bactericidal properties. The modified montmorillonite was characterized through the techniques of Fourier transform infrared spectroscopy (FTIR), Raman spectroscopy and X-ray diffraction (XRD). The FTIR and Raman spectrum’s showed specific bands of involving stretching silver. In the XRD analyses was observed the occurrence of the following crystallographic planes (111), (200) e (220) silver related. The nanocomposites of polyethylene with AgNPs did not show loss in mechanical properties, this fact was important and indicate that the nanomaterial can be inserted in this polymer matrix with considerable technological interest.
Preparation and Characterization of Clay Chocolate "A" Organoclay Using Stearyldimethyl Ammonium Chloride as a Surfactant
Authors: Mota Mariaugusta Ferreira , Patrício Aline Cadigena Lima , da Silva Marcílio Máximo , Freire Rodrigues Meiry Glaúcia
Published: September 2014

Clays modified with quaternary ammonium salts, organoclays, have an affinity for organic compounds undergoing expansion. In this study, the smectite clay Chocolate" A" was subjected to the process of organophilization with quaternary ammoniumchloride, stearyl dimethyl ammonium chloride (Praepagen WB) to improve its hydrophobic properties and thus increase the affinity for organic compounds. The samples were characterized by X ray diffraction (XRD), infrared spectroscopy and tests of expansion by swelling of Foster. The results showed appropriate conditions organophilization process. Through XRD confirmed the increase in basal spacing for the clay modified with respect to the clay in natural, 15.46Å to 19.99Å after treatment with the quaternary ammonium salt. Bands of the CH3 and CH2 were detected by infrared spectroscopy analysis of the sample and the organoclay according to the tests of expansion was possible to observe the affinity of the organoclay with organic compounds: gasoline, kerosene and diesel.
Influence of Zn and Mg Doping on the Sintering Behavior and Phase Transformation of Tricalcium Phosphate Based Ceramics
Authors: Kai Karen C. , Machado Carlos A.V.A. , Genova Luis Antonio , Marchi Juliana
Published: September 2014

β-tricalcium phosphate based ceramics (β-TCP) are resorbable biomaterials used as bone substitutive materials. Several ions can substitute specific Ca positions in the crystalline structure of TCP, so that general Me-TCP can be obtained. Particularly, magnesium can increase the temperature of β-α-TCP transformation while zinc stimulates the bone formation. In this work, the influence of magnesium or zinc ions on the sintering behavior of Me-TCP was investigated. The powders were produced through wet chemical synthesis with a freeze drying process. The powders were calcined and subsequently uniaxially pressed into pellets. The pellets were sintered up to 1300°C/1h. The influence of Mg or Zn doping was investigated by dilatometric studies, thermal analysis and XRD. The microstructure was evaluated through SEM. The results suggest that Mg increased temperature of β-α-TCP phase transformation. The Me-doped TCP samples can be considered as promising biomaterials, having stimulatory effect of Zn or suitable densification due to Mg addition.
Mechanical and Barriers Properties of Chitosan Films with Hydrophilic and Hydrophobic Phytotherapics
Authors: Belisário Amanda Luiza Basílio , de Siqueira Estevam Lívia , Debone Henrique Selli , Pedroso Yoshida Cristiana Maria , Santos Lopes Patrícia , da Silva  Ferreira Classius
Published: September 2014

Chitosan films have been used as dressings for healing burns. The physical and biological properties of these films can be modified by the addition of bioactive substances such as phytotherapics. This work used the casting - solvent evaporation technique for the preparation of chitosan film containing hydrophilic or hydrophobic phytotherapic. The barrier properties, mechanicals properties and microbial penetration were evaluated. The results showed that the films containing the hydrophobic herbal showed lower ability to move fluid and permeability to water vapor compared to the film containing the hydrophilic herbal. For the determination of microbial permeation, film were previously sterilized and were fixed in the mouth of glass vials containing sterile nutrient broth and left on the lab bench for a period of 10 days. Negative and positive controls were also conducted. The chitosan films do not allow the microbial penetration.
Systematic Precipitation of Magnesium Hydroxide Using NH4OH to Preparing MgO-PSZ Precursor Powder
Authors: Yamagata Chieko , Paschoal Jose O.A.
Published: September 2014

The wide range of applications of zirconia based ceramics is due to stabilization of its tetragonal and cubic structures at room temperature, by controlled adding of dopants such as yttria, magnesia, calcia, ceria and some rare earth oxides. The advantage of the use of magnesia as dopant is not only due to its low cost, but fact that by controlling its ceramic processing, it is possible to control a specific microstructure for the specific application. The precipitation of magnesium hydroxides, using NH4OH as a precipitant, presents some difficulties due to the formation of a variety of soluble complexes of ammonia with magnesium, which inhibits the total precipitation of magnesium. In the present work, the influence of precipitant and metals concentrations and pH on the magnesium hydroxide precipitation was investigated. Magnesium chloride, zirconium oxychloride and NH4OH were used as starting materials. The precipitation of magnesium hydroxide depends on concentrations of OH-, Cl- and Mg2+. To achieve specific precipitation yield, lower the concentration of Mg2+ high molar ratio of [OH-]/[Cl-] is required. The pH measure is not enough to control Mg (OH)2 precipitation. The use of molar ratio of [OH-]/[Cl-] = 4.4, resulted in 95 % of Mg (OH)2 precipitation. The co-precipitation of Zr and Mg hydroxides, using the optimized molar ratio of [OH-]/[Cl-], the precipitation of Mg (OH)2 achieved in range of 97.6 to 98.3 %.
The requirement of the law fulfilled in Romans 8:4
Authors: Venter Dirk J.
Published: September 2014

God effects the fulfilment of the requirement of the law through the agency (mission) of Christ. Those ‘in him’ are the point of reference in whose favour the law’s requirement is fulfilled, with the effect that they are no longer obligated to Torah. Being ‘in Christ’ they, nonetheless, are also envisioned as living in a way that corresponds to what Torah would have required of them, had they still been subject to it, but they are now being governed and empowered by the Spirit. Consequently their lives give expression to the ultimate (singular) requirement and intention (δικαίωμα) of Torah. The fulfilment of the requirement of the law refers to the purpose of the law as a whole, and not only of the ‘moral’ aspect, often anachronistically separated from the ‘cultic’ aspect. Ultimately, God who originally gave Torah now effected the fulfilment of its intention − something that had been unrealised before the mission of Christ and the gift of the Spirit due to the incapability of the law.Die vervulling van die wet se vereiste in Romeine 8:4. God bewerk die vervulling van die wet se vereiste (δικαίωμα) deur die bemiddeling van (die sending van) Christus. Dié wat ‘in Christus’ is, is die begunstigdes van die feit dat die vereiste van die wet vervul is, met die gevolg dat hulle nie meer aan die bepalinge van Tora as sodanig onderhewig is nie. Aangesien hulle ‘in Christus’ is, word dit egter voorsien dat hulle steeds sodanig sal leef dat dit ooreenstem met wat Tora in beginsel van hulle sou vereis indien hulle steeds daaraan onderhewig was, maar dat hulle dit nou vanweë die heerskappy en bekragtiging van die Gees uitleef. Gevolglik gee hulle lewens gestalte aan die uiteindelike (enkelvoudige) doel en vereiste (δικαίωμα) van Tora. Die vervulling van die wet se vereiste verwys nie na die vervulling van slegs die ‘morele’ vereistes nie, maar ook na dít wat dikwels op anachronistiese wyse as die ‘seremoniële’ wet afgesonder word. Uiteindelik het God, wat Tora oorspronklik daargestel het, die vervulling van die wet se bedoeling gerealiseer − iets wat vanweë die onvermoë van die wet ongerealiseerd gebly het in die epog voor die koms van Christus en die gawe van die Gees.