Search

The offer of business process modeling methodologies is quite extensive, making it difficult for scholars in the BPM area to choose properly. In this context, this paper has the objective to present the main modeling methodologies, with applications, examples and comparisons. A systematic bibliographic survey and the comparative analysis of these notations used in the implementation of BPM projects have been carried out. According to the bibliometric analysis, the modeling notations of the business process most portrayed in the works surveyed are: BPMN, UML, EPC and IDEF. From the construction of a consistent overview that allows the comparative analysis of the methodologies, in order to select the one that suits better its specificities it can be verified that, although they share the same objective, each notation has its specific characteristics. This study has the main purpose of providing a basis for the adequate indication of the application of studies in the field, especially those destined for papers, dissertations and theses. Resumo: A oferta de metodologias de modelagem de processos de negócios é bastante extensa, dificultando os estudiosos da área de BPM uma escolha adequada. Nesse contexto, este artigo tem o objetivo de apresentar as principais metodologias de modelagem, com aplicações, exemplos e comparações. Foi realizado um levantamento sistemático bibliográfico e análise comparativa dessas notações utilizadas na implementação de projetos BPM. De acordo com a análise bibliométrica, as notações de modelagem de processos de negócio mais retratadas nos trabalhos levantados são: BPMN, UML, EPC e IDEF. A partir da construção de um overview consistente que permita a análise comparativa das metodologias, a fim de selecionar aquela que mais se adequa às suas especificidades pode-se verificar que, embora partilhem o mesmo objetivo, cada notação tem as suas características específicas. Este estudo possui propósito principal de servir de base para a indicação adequada a aplicação de estudos na área, em especial aos destinados a papers, dissertações e teses.

As embarcações que prestam apoio para as atividades marítimas apresentam um crescimento significativo frente às demandas do mercado offshore de Óleo e Gás. Estas embarcações podem ser nacionais ou afretadas de países estrangeiros, sendo reguladas pela Agência Nacional de Transportes Aquaviários e fiscalizadas pelo Poder Marítimo representado pela Marinha Nacional. O peso do valor pago em afretamentos estrangeiros é significativo, porém existem programas de construção de novas embarcações, tendo como vetor do desenvolvimento nacional o conteúdo local. Esta indústria enfrenta desafios de maior disponibilização de estaleiros, desenvolvimento do seu corpo técnico e gerencial com foco em rentabilidade e possível restrição de formação de profissionais do setor.

Companies are progressively investing in practices aimed at improving the quality of management, with the main purpose of enabling them to operate competitively in the present market. For this, it is necessary to document the activities and information of the existing business processes in the organization, aiming at reducing time and cost in the elaboration of the particular model. In this context, the objective of this work is to develop a reference model of the Master Production Schedule (MPS) processes, an important module of production planning and control (PPC). The research methodology used in this work was divided into the following stages: study of MPS and business process modeling, definition of reference model processes, choice of methodology and process modeling tool, development of reference model and prototype of the software and, finally, analysis of results. The modeling notation used was the BPMN, since it is considered a standard language in the field of process modeling. The prototype was developed through the Delphi interface in order to apply the model to support the implementation of business management programs. As results, from a formal documentation, the model proved to be a useful mechanism in the understanding of the processes raised and appropriate in the support to the implantation of production management tools.

Rapanea ferruginea antioxidant and antitumoral properties were not explored before in literature. This study aimed to investigate these biological activities for the R. ferruginea leaf extract and correlate them with its phenolic content and influence in biological membrane dynamics. Thus, in this study, anti/pro-oxidative properties of R. ferruginea leaf extract by in vitro DPPH and TBARS assays, with respect to the free radical reducing potential and to its activity regarding membrane free radical-induced peroxidation, respectively. Furthermore, preliminary tests related to the extract effect on in vitro glioma cell viability were also performed. In parallel, the phenolic content was detected by HPLC-DAD and included syringic and trans-cinnamic acids, quercetrin, catechin, quercetin, and gallic acid. In an attempt to correlate the biological activity of R. ferruginea extract and its effect on membrane dynamics, the molecular interaction between the extract and a liposomal model with natural-sourced phospholipids was investigated. Location and changes in vibrational, rotational, and translational lipid motions, as well as in the phase state of liposomes, induced by R. ferruginea extract, were monitored by Fourier-transform infrared spectroscopy, nuclear magnetic resonance, differential scanning calorimetry, and UV-visible spectroscopy. In its free form, the extract showed promising in vitro antioxidant properties. Free-form extract (at 1000µ g/mL) exposure reduced glioma cell in vitro viability in 40%, as evidenced by MTT tests. Pro-oxidant behavior was observed when the extract was loaded into liposomes. A 70.8% cell viability reduction was achieved with 500 µg/mL of liposome-loaded extract. The compounds of R. ferruginea extract ordered liposome interface and disorder edits a polar region. Phenolic content, as well as membrane interaction and modulation may have an important role in the oxidative and antitumoral activities of the R. ferruginea leaf extract.

In this study, α-eleostearic acid-loaded (α-ESA-loaded) dimyristoylphosphatidylcholine (DMPC) liposomes had their physicochemical properties characterized by horizontal attenuated total reflectance Fourier transform infrared (HATR-FTIR) spectroscopy, nuclear magnetic resonance (NMR) and differential scanning calorimetry (DSC). In vitro thiobarbituric acid reactive substance (TBARS) assays were performed to obtain preliminary information on the oxidative potential of the system. An α-ESA-promoted ordering effect in the lipid phosphate region was observed. It was associated with a rotation restriction due to an increase in the amount of lipid group hydrogen bonds. The fatty acid was responsible for the reduction in the degree of hydration of carbonyl groups located in the interfacial region of lipids. α-ESA disordered the DMPC methylene acyl chains by trans - gauche isomerization and increased its rotation rate. TBARS results showed pro-oxidant behavior on liposomes, induced by α-ESA. The discussion about the responses considered the degree of saturation of phosphatidylcholines and suggested that the α-ESA oxidative effects may be modulated by the liposome lipid composition. The versatility of liposomal carriers may be promising for the development of efficacious α-ESA-based drug delivery systems. Results described in this study contribute to the selection of adequate material to produce them.

In the perspective of organizational context, the present paper deals with the different types of architecture of BPM (Business Process Modeling). As objectives, it is proposed to formulate a conceptual comparative view of the main architectures present in the scientific literature. As for the methodology, bibliographical and webibliomining research are employed in a qualitative and quantitative approach to the subject. As a result, the comparative view of the UML, BPMN, CIMOSA, IDEF, ARIS, IEM, GRAI, GERAM and EKD architectures is developed, in terms of temporal aspects, socio-technical characteristics, visualization and analysis, among other factors which offers substantial argument to decide what framework is better in each scenario.

The offshore labor regime is very common in companies operating in the Campos Basin, due to the large number of companies that operate in the petroleum exploration and production processes, including companies that support these operations, which also require the professionals to work on board. The life quality is directly linked to the results, because it interferes in behavioral aspects important for individual and collective productivity. This research aimed to study and analyze the aspects of this work regime that has peculiar characteristics, and the relation with the quality of life of the professionals that work on board, so that positive and negative points could be identified, and to seek possible improvements. The methodology used to develop the study involved an exploratory research in consonance with the bibliographical study. As an instrument for data collection, a questionnaire with closed questions was used, aimed at professionals working on board. This issue is relevant for organizations, since the life quality affects the physical and psychological condition and also, the satisfaction of professionals, interfering in the performance and consequently in the results.

The adoption Enterprise Resource Planning (ERPs) by small and medium-sized businesses may not possible its cost. At same time, whenever adapt ERP specific needs company, user becomes dependent developers due to the lack access and knowledge respective code. Free and open source software can promote advantages companies, however, for their adoption, it is necessary to develop techniques tools facilitate implementation and maintenance code. This article highlights the importance of defining modeling architectures and reference models for development and maintenance open source ERPs, especially the ERP5 project.

The teaching of practical subjects such as PPC (Production Planning and Control) can be enhanced through the use of suitable educational software as it engenders aspects of dynamism and interactivity in the learning process. The present article aims to develop a webibliomining analysis in order to expose the theoretical framework and to explain the state of art of research related to PPC in scientific literature. The key content of PPC topics will be used as a guideline for the development of an specific educational software framework. As for the methodology, bibliographic and bibliometric research resources were used to compose the webibliomining analysis, thus making the article acquire the character of qualitative and quantitative research. The renowned Web of Science database and Nails software were used in order to formulate and prioritize the PPC content. As a result of this, the product of the article consists of the framework of the referred software which has highly relevant content because it is aligned with the inputs generated by the use of webibliomining resource as a facilitating tool on content selection of PPC subjects seeking to increase the learning process efficiency by students of engineering and business at Brazilian universities.

The activity of modeling business processes is still not a common practice among organizations which contributes to increase the cost and time of systems deployment, improvement projects and educational software, due to the need to develop new models related to Business Processes. In this context, one of the Business Processes essential for organizations, especially those located in countries such as Brazil, where production activities are more pronounced than product development, is Production Planning and Control (PCP). In this scenario, in order to present a picture of scientific production, contribute to the literature review and identify gaps in the scientific literature within the framework of the Reference Models and PCP approach. This work aims to perform a bibliometric research in these areas of study. In this study, we used the bibliometric revision method composed of four phases: definition of database, definition of research keywords, selection of papers and analysis of papers. As a result, it was found that most scientific studies are focused on very specific situations in industrial planning or addressing particular business sectors.

Companies are increasingly adopting practices aimed at improving the quality of management, with the main purpose of enabling them to act competitively in the present market characterized by high competition and strong organizational changes. Among the improvements developed, we highlight the adoption of Enterprise Resource Planning (ERP) systems. However, the high cost of deploying and maintaining this type of technology can be a barrier for small and medium-sized enterprises (SMEs) that want to achieve such advances. Therefore, it is essential to develop a reference model of typical business planning modules to support ERP implementation, aiming at reducing time and cost in the elaboration of a particular model. In this context, the main objective of this paper is to develop a reference model from the elaboration of the processes related to Sales Operations Planning (SOP) and Aggregate Planning (AP), important modules of Production Planning and Control (PPC). The methodology used for the elaboration of this work was divided in eight sequential stages: study of the functions of SOP and AP, study of process modeling area, definition of reference model processes, choice of modeling notation, choice of modeling tool , development of the reference model, software development and results analysis. The modeling methodology employed in this work was the Business Process Model and Notation (BPMN), through the tool Bizagi Process Modeler version 3.1.0.011. The software was developed through the interface Delphi version 7.0 (Object-Pascal language) in order to apply the reference model in the support to the implementation of a business management tool. As results, from a formal documentation, the reference model proved to be a useful tool in understanding and communicating the business processes raised. It is also concluded that the implemented model is able to support the implementation of production management systems in real situations.

Companies are progressively investing in practices aimed at improving the quality of management, with the main purpose of enabling them to operate competitively in the present market. For this, it is necessary to document the activities and information of the existing business processes in the organization, aiming at reducing time and cost in the elaboration of the particular model. In this context, the objective of this work is to develop a reference model of the Manufacturing Resource Planning (MRP) processes, an important module of production planning and control (PPC). The research methodology used in this work was divided into the following stages: study of MRP and business process modeling, definition of reference model processes, choice of methodology and process modeling tool, development of reference model and prototype of the software and, finally, analysis of results. The modeling notation used was the BPMN, since it is considered a standard language in the field of process modeling. The prototype was developed through the Delphi interface in order to apply the model to support the implementation of business management programs. As results, from a formal documentation, the model proved to be a useful mechanism in the understanding of the processes raised and appropriate in the support to the implantation of production management tools.

The study of behavioral finance is characterized by analyzing the volatility of financial markets, however, in a contemporary view, one can also apply it in other fields such as commerce and factories, and its dislike to be able to invest or not its financial capital . The objective of this work is to present foreign reflections on a new branch in financial theory, Behavioral Finance, which aims to adhere the psychological and sociological aspects of the individuals in the decision making process at the time of making an investment, as well as their applications through incorporation evidence of the investor's irrationality. This new segment aims to review and improve the current economic-financial model. The association with behavioral finances provides both the understanding of the psychological process that motivates the investments, helping in the construction of a more adequate decision-making model, and in the hiring of its managers who must possess adequate technical and psychological skills in order to avoid cognitive bias as overconfidence.

Companies are progressively investing in practices aimed at improving the quality of management, with the main purpose of enabling them to operate competitively in the present market. For this, it is necessary to document the activities and information of the existing business processes in the organization, aiming at reducing time and cost in the elaboration of the particular model. In this context, the objective of this work is to develop a reference model of the Production Scheduling (PS) processes, an important module of production planning and control (PPC). The research methodology used in this work was divided into the following stages: study of PS and business process modeling, definition of reference model processes, choice of methodology and process modeling tool, development of reference model and prototype of the software and, finally, analysis of results. The modeling notation used was the BPMN, since it is considered a standard language in the field of process modeling. The prototype was developed through the Delphi interface in order to apply the model to support the implementation of business management programs. As results, from a formal documentation, the model proved to be a useful mechanism in the understanding of the processes raised and appropriate in the support to the implantation of production management tools.

As empresas estão, progressivamente, investindo em práticas voltadas para melhorias da qualidade da gestão, com a finalidade principal de habilitá-las a atuar de forma competitiva no presente mercado. Para isso, se faz necessário a documentação das atividades e informações dos processos de negócios existentes na organização, visando redução de tempo e custo na elaboração do modelo particular. Nesse contexto, o objetivo deste trabalho é desenvolver um modelo de referência dos processos do Planejamento de Requisitos de Materiais (MRP), importante módulo do planejamento e controle da produção (PCP). A metodologia de pesquisa empregada neste trabalho foi dividida nas seguintes etapas: estudo do MRP e da modelagem de processos de negócios, definição dos processos do modelo de referência, escolha da metodologia e ferramenta de modelagem de processos, desenvolvimento do modelo de referência e do protótipo do software e, por fim, análise de resultados. A notação de modelagem empregada foi o BPMN, pois é considerada uma linguagem padrão no campo de modelagem de processos. O protótipo foi desenvolvido através da interface Delphi com o intuito de aplicar o modelo no apoio à implantação de programas de gestão empresarial. Como resultados, a partir de uma documentação formal, o modelo mostrou-se um mecanismo útil na compreensão dos processos levantados e apropriado no suporte à implantação de ferramentas de gestão da produção.

The theme of “Software Quality Evaluation”, and its importance, concerns the standardization of the development processes, in order to guarantee a higher quality of the systems. In this scenario, this theme has gained importance in academic research, due to the emphasis that the theme has increasingly presented to organizations, since they understand that the main objective is to guarantee a final product that satisfies the expectations of the client. In order to verify the scientific scenario in recent years, this work aims to carry out a review of the literature on “Software Quality Evaluation”, based on a bibliometric analysis and review. For this, the method of bibliographic revision with four different phases proposed by Marasco (2008) was used. From the data extracted from the Scopus database, the results of the systematic review and bibliometric analysis were analyzed from the information on publications, citations and approaches of the papers that deal with this subject. As results, the present article showed the academic and practical importance of the studies on “Software Quality Evaluation”. In addition, it is possible to identify gaps in the scientific literature that can be filled by future work in the area, based on the studies developed by specialists.

The atomic short range order of a mechanically alloyed amorphous Ni30Nb70 alloy (a-Ni30Nb70) was determined using two total structure factors S(K) derived using anomalous wide angle X-ray scattering (AWAXS) measurements as input data for reverse Monte Carlo (RMC) simulations. The coordination numbers (Nij) and interatomic distances (Rij) for the first neighbors were obtained. The chemical short range order (CSRO) and the chemical medium range order (CMRO) of a-Ni30Nb70 were investigated using the Cowley-Warren parameter αCW. The results suggest a preference for homopolar pairs or clusters in the first and second coordination shells. The angular distribution of bonds between first neighbor atoms is taken as evidence for the presence of distorted polyhedral units with triangular and square faces in the atomic structure of a-Ni30Nb70.

Polymer matrix composites have been applied in components such as helmets and shielding for which tough-ness is a major requirement. Natural fiber presents interfacial characteristics with polymeric matrices that favor a high impact energy absorption by the composite structure. The objective of this work was then to assess the Izod impact resistance of polymeric composites reinforced with different amounts, up to 30% in volume, of a promising high strength natural fiber from the Amazon region known as curaua. Among these, the piassava fiber extracted from a palm tree native of South America stands as one of the most rigid with a potential to be used as composite reinforcement. Therefore, the present work investigates the notch toughness behavior, by Izod impact tests, of epoxy composites reinforced with up to 40 % in volume of continuous and aligned piassava fibers.The results showed a remarkable increase in the notch toughness with the amount of incorporated curaua fibers. This can be attributed to a preferential debonding of the fiber/matrix interface, which contributes to an elevated absorbed energy. . It was found that the incorporation of piassava fibers results in significant increase in the impact energy of the composite. Scanning electron microscopy analysis showed that the nature of the piassava fiber interface with the epoxy matrix is the major responsible for the superior toughness of the composite. Keywords:Piassava, curaua, polymer matrix, epoxy matriz, Izod

A Programação da Produção tem recebido atenção de pesquisadores da área de Pesquisa Operacional desde a década de 50 e um grande número de trabalhos foi desenvolvido desde então, da mesma forma, devido à Internet, o rastreamento bibliográfico de um campo de pesquisa está vez mais demorado, como também encontrar relações entre autores e publicações relevantes, está ficando cada vez mais difícil, devido ao crescente volume de informações. Dessa forma, este trabalho busca realizar uma revisão de mapeamento sistemático, com relação à programação da produção e algumas das principais meta-heurísticas (Hill Climbing, Simulated Annealing, TabuSearch,Harmony Search, GRASP, Evolutionary Algorithms, Genetic Algorithms, Evolution Strategies, Genetic Programming, Differencia lEvolution, Evolutionary Programming, Particle Swarm Optimization, Memetic Algorithms e Ant Colony), através de indicadores bibliométricos e análise de redes (Page Rank), busca-se demonstrar a relação de artigos, autores e publicações mais importantes e de maior prestígio de dados originados da base Web of Science com auxílio das ferramentas NAILS e GEPHI. Finalmente, é demonstrado que a utilização de meta-heurísticas na Programação da Produção - PP, apesar de ser uma linha de pesquisa antiga, ainda se mantém com grande interesse e em constante desenvolvimento.

Environmental considerations in addition to technical, economical and societal benefits are increasingly promoting the substitution of natural fibers for glass fiber in polymer matrix composites. However, natural fibers are heterogeneous in their dimensions, specially the cross section, which plays an important role in their mechanical strength. It has been found that the equivalent diameter of fibers such as sisal, ramie, pinea-pple and curaua correlates to different levels of tensile resistance. Piassava is a promising stiff natural fiber for composite reinforcement. In this work, a statistical analysis of tensile strength of piassava fibers using the Weibull methodology was performed. An attempt to correlate the fiber strength, obtained in tensile tests, with the diameter, precisely measured by means of a profile projector, was carried out. The results revealed an inverse dependence between the piassava fiber diameter and corresponding tensile strength. Fracture tip observation by SEM suggested a possible mechanism that could justify this inverse correlation. Keywords: piassava fiber, testing traction, strength/diameter correlation.

Maintenance shutdown tasks on offshore platforms generate large revenue losses for companies in addition to high costs, partially caused by environmental adverse conditions, distances from workplaces, and large volume of materials. The use of an efficient asset controlling and monitoring system reduces these costs and improves their resource management. This work describes the development of a web/mobile architecture system integrated with radio frequency identification (RFID) transponders for asset tracking in maintenance shutdown processes on offshore platforms. For this study development, we visited an oil and gas company, located in the city of Macaé, Rio de Janeiro, Brazil to analyze its processes. The company was facing problems on its asset management, and tracking material processes. The former takes place in two different sites. It is performed not only on-shore, but also offshore (on oil and gas platforms). Therefore, it was developed a web/mobile system integrated with RFID transponders to tackle these problems. This system enhances efficiency in processes, reduces costs and losses because of production downtime. Its tracking is able to save up to 5.5 (five and a half) days at the laydown yard and approximately 7 (seven) days on the platform. Besides that, it ensures greater assertiveness, thus decreasing the level of materials’ replacement in the tasks, which was one of the main causes for delays in these processes. Other results are related to its managerial processes. They became automated once the RFID system integrates data in real time, and all the items from tasks defined as priorities were identified. The experimented efficiency suggests to use open source tools to reduce the system development costs, and analyze the use of RFID throughout the oil and gas supply chain, as well as studying other applications and systems in different supply chains, focusing on ways to optimize costs for the company. Additionally, it enabled the monitoring of assets and processes throughout the supply chain, besides providing information and knowledge for companies.

U-xZr-yNb alloys with values of x varying from 32% to 50% (wt.%Zr) and y varying from 6% to 10% (wt.%Nb) were produced by the arc melting technique. The effect of the addiction of zirconium and niobium on the phase stabilization of γ-U, lattice parameter, microstructure and elemental composition were examined by X-ray diffraction (XRD), scanning electron microscopy (SEM) and energy dispersive spectroscope (EDS) techniques. The alloys crystallized in a cubic symmetry composed by a γ-U(Zr,Nb) matrix and β-Zr small precipitates, when the content of zirconium and niobium is up to 55 wt.%. With further additions, e.g. 60 wt.%, was observed a highly enriched macrosegregation of β-Zr. It was also observed that the cell size of the γ-U(Zr,Nb) phase increase with the addition of Zr and Nb. The lattice parameter curve behavior as a function of zirconium and niobium deviates from a linear behavior at around x ≈ 50 and y ≈ 10 wt.%.

In the perspective of organizational context, the present paper deals with the different types of architecture of BPM. As objectives, it is proposed to formulate a conceptual comparative view of the main architectures present in the scientific literature. As for the methodology, bibliographical and webibliomining research are employed in a qualitative and quantitative approach to the subject. As a result, the comparative view of the UML, BPMN, CIMOSA, IDEF, ARIS, IEM, GRAI, GERAM and EKD architectures is developed, in terms of temporal aspects, socio-technical characteristics, visualization and analysis, among other factors which offers substantial argument to decide what framework is better in each scenario.

The curaua fiber is one of the strongest lignocellulosic fibers and is currently being considered as reinforcement of polymer composites for industrial applications such as automobile interior components and bicycle helmets. The tensile strength of the curaua fiber was found to display an inverse variation with its corresponding equivalent diameter. Since the stiffness of the fiber is also important for its use as composite reinforcement, the present work investigated the dependence of the elastic modulus of curaua fibers with the associated diameters. The results confirmed the existence of an inverse dependence between the elastic modulus and the fiber diameter. In principle, this could allow a selection of stiffer curaua fibers to be used as reinforcement in polymer composites with comparatively higher elastic modulus. A possible mechanism for this inverse dependence is discussed following structural differences between thicker and thinner fibers.

This paper presents morphology, physical and strength properties of piassava fiber, a very rigid fiber having a potential to be used as composite reinforcement. Composites of continuous and aligned piassava fibers with and without alkali treatment dispersed in epoxy matrix were subjected to three point bend, tensile, and Izod impact tests. Composites with fibers above 20 vol.% showed an effective reinforcement behavior both in flexural and tensile tests, while the impact energy linearly increased for the amount of piassava fibers used in this study. Fractographic study revealed a relatively weaker fiber/matrix adhesion acting as preferential site for crack nucleation. Evidence was also found for crack arrest by the fiber above 20 vol.%. This, together with spiny surface protrusion in the piassava fibers, was found to be responsible for the reinforcement of the epoxy composites.

O presente trabalho analisa o processo de reciclagem da garrafa pet em uma empresa localizada no município de Campos dos Goytacazes, a partir do conceito de logística reversa. Buscou-se, através de pesquisa qualitativa junto à empresa conhecer o processo de reciclagem da garrafa PET e seu entendimento enquanto contribuição para a questão ambiental. Foram realizadas visitas à empresa em por um período de 1 mês, em horários alternados durante o expediente de trabalho observando desde a chegada do material recolhido nas ruas até o final do processo de reciclagem, juntamente com as visitas realizadas foi aplicado um questionário com os funcionários da empresa com o intuito de mensurar o entendimento dos mesmos sobre o processo de reciclagem. Foi desenvolvido o fluxograma de processos e o mapeamento, visando permitir não somente conhecer a seqüência do processo desenvolvido, mas também, analisá-lo em termos de pontos fortes e fracos. Após o levantamento dos dados verificou-se, que no se refere ao processo produtivo, os funcionários executavam suas tarefas de forma empírica, conhecendo somente a etapa do processo pela qual era responsável, e que os mesmos e a empresa não possuíam nenhum procedimento formal que demonstrasse as etapas seqüenciais envolvidas no processo de reciclagem.

By means of dimensional selection of natural lignocellulosic fibers, based on precise diameter measurements, it was recently possible to obtain fibers with relatively higher tensile strength. The present article overviews works on the statistical evaluation, through the Weibull analysis, of the ultimate tensile stress of eight lignocellulosic fibers: sisal, ramie, curaua, jute, bamboo, coir, piassava and buriti. It is shown that, for all of these fibers, the tensile strength holds an inverse relationship with the fiber diameter. Statistically this relationship conforms to a hyperbolic type of analytical equation, which discloses the possibility of unusually high strength fibers to be selected in association with very small diameters. A structural analysis using scanning electron microscopy offered an explanation to the strengthening mechanisms responsible for the superior performance of these dimensionally selected fibers.

Natural fibers obtained from cellulose-based plants are being used as reinforcement of polymer composite owing to both environmental and technical advantages. One important technical characteristic of most lignocellulosic fibers is the bend flexibility, which allows them to resist impact forces. As a consequence, there is an increasing application of these lignocellulosic fibers in automobile parts that, during a crash event, should absorb the impact energy without splitting into sharp pieces. The present work investigates the toughness behavior of polyester composites reinforced with up to 30% in volume of alkali treated continuous and aligned curaua fibers by means of Charpy impact tests. It was found that the incorporation of treated curaua fibers increased the composite absorbed impact energy but not as much as in composites reinforced with non-treated fibers. Macroscopic observation, and scanning electron microscopy analysis of fracture surface, revealed that the main mechanism for the increase in the Charpy notch toughness is the interfacial rupture between the curaua fiber and the polyester matrix.

Natural fibers, especially lignocellulosic fibers extracted from plants, are gaining attention as polymer-matrix composite (PMC) reinforcements due to their comparative advantages over synthetic fibers. Natural fibers are relatively low cost, renewable, and biodegradable. Their production systems are associated with low equipment wear and are energy efficient. In addition, the incorporation of lignocellulosic fibers into PMCs may significantly improve some mechanical properties. This article presents an overview of the advantages and drawbacks of applying natural fibers, some of them relatively unknown, as reinforcements of PMCs. The mechanical behavior of composites incorporated with selected fibers is discussed in terms of the effect of surface micromorphology and the fiber/matrix interaction.

The effect of pressure on mechanically alloyed nanostructured Gd3Fe5O12 was investigated using in situ angle-dispersive X-ray diffraction measurements at room temperature. No structural phase transitions were observed, but an anomalous behavior in the volume vs. pressure curve, attributed to nonhydrostatic effects, was observed in the pressure range between 4.4 GPa and 9.1 GPa. The analysis of effect of pressure on the Wickoff 23c sites, occupied by Gd3+ ions, 16a and 24d sites, occupied by Fe3+ ions, and 96h sites, occupied by O2– ions, was performed. The value of the bulk modulus B0 for nanostructured Gd3Fe5O12 could not be determined due to nonhydrostatic effects associated with the silicone oil used as a pressure transmitting medium.

Lignocellulosic fibers have been recognized as attractive fillers for different types of matrices in polymeric composites. Their advantages such as recyclability and renewability are unique characteristics for composites used as automobile components and building structural panels. In view of the hydrophobic behavior of most polymers and the hydrophilic nature of lignocellulosic fibers, poor adhesion is observed between lignocellulosic fibers and the polymeric matrix, which results in lower mechanical properties. Pullout tests have been successfully used to determine the interfacial shear stress in synthetic fiber-reinforced composites, but little has been reported in the case of lignocellulosic fiber–polymer composites. This chapter presents an overview on the determination of the interfacial strength of lignocellulosic fibers–polymer matrix composites including some obtained by the authors on Brazilian fibers such as curaua, ramie, and piassava, considered as reinforcement for composites. Concluding remarks and suggestions indicate some future works.

A thermodynamic analysis of the Cr-Ge system suggested that it was possible to produce a nanostructured Cr3Ge phase by mechanical alloying. The same analysis showed that, due to low activation energies, Cr-poor crystalline and/or amorphous alloy could also be formed. In fact, when the experiment was performed, Cr11Ge19 and amorphous phases were present for small milling times. For milling times larger than 15 h these additional phases decomposed and only the nanostructured Cr3Ge phase remained up to the highest milling time used (32 h). From the differential scanning calorimetry measurements, the Avrami exponent n was obtained, indicating that the nucleation and growth of the nanostructured Cr3Ge phase may be restricted to one or two dimensions, where the Cr and Ge atoms diffuse along the surface and grain boundaries. In addition, contributions from three-dimensional diffusion with a constant nucleation rate may be present. The thermal diffusivity of the nanostructured Cr3Ge phase was determined by photoa...

A empresa colocada como objeto de estudo nesse trabalho de conclusão de curso, juntamente comoutras empresas da indústria petrolífera, estão mudando seus olhares em relação à logística e administração demateriais, devido ao seu papel fundamental na integração da cadeia de suprimentos de uma empresa. Destarte,assegurando a manutenção de uma base de dados adequada e confiável, contribuindo para a integração entre osórgãos envolvidos e destes seus diversos usuários, através de um tratamento adequado e homogêneo dos dados,com confiabilidade e presteza; além de assegurar um nível mínimo de suprimento compatível com o necessáriopara a atividade, evitando principalmente, o risco da falta de material de contingência.O outro ponto positivo quepodemos citar foi a adesão do organograma proposto para o processo de gestão de materiais, além dodesenvolvimento de treinamento aos colaboradores envolvidos no processo

This paper presents systematic studies carried out on the processing and characterization of continuous and aligned curaua fibers-polyester composites. Laminates of these composites with (0 to 40 vol. %) curaua fibers were press-molded at room temperature, cured for 24hours and tested for strength properties. Resulting fracture surfaces were analyzed by scanning electron microscope. Composites showed high flexural properties, which is attributed to a complex mechanism of individual interaction of the microfibrils with the matrix during crack initiation and further propagation through a model of stress concentration due to the specific fiber/matrix interface geometry. Impact test results showed a remarkable increase in the notch toughness with the amount of incorporated curaua fibers, which is attributed to the difficulty of breaking down the fibers and preferential de-bonding of the fiber/matrix interface, which in turn contributes to an elevated absorbed energy.