Green logistics: key elements for a well-functioning sustainable logistics system

A growing awareness of the modern society about the direct relationship between a growing global community with increasing total industrial activities on one hand and various environmental problems and a natural limitation of natural resources on the other hand set the base for sustainable or “green” approaches within the supply chain. This paper therefore will look at the issue of “Green Logistics” which seeks to reduce the environmental impact of logistics activities by taking into account functions such as recycling, waste and carbon emission reduction and the use of alternative sources of energy. In order to analyze how these approaches and ideas are being perceived by the system as a whole two models from the area of prospective and scenario planning are being used and described to identify the main drivers and tendencies within the system in order to create feasible hypothesis. Using the URCA/CHIVAS model allows us to identify the driver variables out of a high number of variables that best describe the system “Green Logistics”. Followed by the analysis of the actor’s strategies in the system with the Mactor model it is possible to reduce the complexity of a completely holistic system to a few key drivers that can be analyzed further on. Here the implications of URCA/CHIVAS and Mactor are being used to formulate hypotheses about the perception of Green Logistics and its successful implementation among logistics decision makers by an online survey. This research seeks to demonstrate the usefulness of scenario planning to a highly complex system observing it from all angles and extracting information about the relevant factors of it. The results of this demonstration indicate that there are drivers much beyond the factory walls that need to be considered when implementing successfully a system such as Green Logistics.

Utilização de mercados artificiais com formadores de mercado para análise de estratégias

Na modelagem de sistemas complexos, abordagens analíticas tradicionais com equações diferenciais muitas vezes resultam em soluções intratáveis. Para contornar este problema, Modelos Baseados em Agentes surgem como uma ferramenta complementar, onde o sistema é modelado a partir de suas entidades constituintes e interações. Mercados Financeiros são exemplos de sistemas complexos, e como tais, o uso de modelos baseados em agentes é aplicável. Este trabalho implementa um Mercado Financeiro Artificial composto por formadores de mercado, difusores de informações e um conjunto de agentes heterogêneos que negociam um ativo através de um mecanismo de Leilão Duplo Contínuo. Diversos aspectos da simulação são investigados para consolidar sua compreensão e assim contribuir com a concepção de modelos, onde podemos destacar entre outros: Diferenças do Leilão Duplo Contínuo contra o Discreto; Implicações da variação do spread praticado pelo Formador de Mercado; Efeito de Restrições Orçamentárias sobre os agentes e Análise da formação de preços na emissão de ofertas. Pensando na aderência do modelo com a realidade do mercado brasileiro, uma técnica auxiliar chamada Simulação Inversa, é utilizada para calibrar os parâmetros de entrada, de forma que trajetórias de preços simulados resultantes sejam próximas à séries de preços históricos observadas no mercado.

Prototexto, narrativa poética da ciência: uma estratégia de construção do conhecimento e religação de saberes no ensino de física

In this thesis I present the prototexto notion and to I base as a complex system while strategy of knowledge construction and reconexion of you know in physics teaching. Prototexto is a poetic narrative of the science, proposal and used initially as "instrument of creative" learning for students apprentice of science of the medium and technical teaching of the Vitória da Conquista's CEFET-BA, in the period of 1997-2004. Later become pregnant as a strategy of knowledge construction, in the Universidade Estadual da Bahia - UESB, the prototexto notion configures a complement to the mathematical formulation. The proposal of a poetic narrative of the science is that the apprentice of science starts to organize in an aesthetic-literary way your knowledge, dispersed in disciplines, starting from a theme of the physics. The prototexto emerges of my reflections concerning the classic science, identified for Edgar Morin as tends a thought excessively numeric, and that it has been reproduced in physics teaching, in most of the schools, limiting him/it to an order pattern with the mistake absence. They are operations of the prototexto: the poetic language, the pedagogic stamp, the unfinished of the argument, the system character and the apprentice's of science inclusion as subject implicated in the construction of the knowledge. the theoretical foundations are based Morin's proposition of the method as strategy, the beginning of the complementarity of Niels Bohr in conceiving excluding categories as face of a same phenomenon and the conception of creative time of Ilya Prigogine that enunciates the alliance among the nature and the man that it describes her

Agentes Inteligentes com Foco de Atenção Afetivo em Simulações Baseadas em Agentes

Simulations based on cognitively rich agents can become a very intensive computing task, especially when the simulated environment represents a complex system. This situation becomes worse when time constraints are present. This kind of simulations would benefit from a mechanism that improves the way agents perceive and react to changes in these types of environments. In other worlds, an approach to improve the efficiency (performance and accuracy) in the decision process of autonomous agents in a simulation would be useful. In complex environments, and full of variables, it is possible that not every information available to the agent is necessary for its decision-making process, depending indeed, on the task being performed. Then, the agent would need to filter the coming perceptions in the same as we do with our attentions focus. By using a focus of attention, only the information that really matters to the agent running context are perceived (cognitively processed), which can improve the decision making process. The architecture proposed herein presents a structure for cognitive agents divided into two parts: 1) the main part contains the reasoning / planning process, knowledge and affective state of the agent, and 2) a set of behaviors that are triggered by planning in order to achieve the agent s goals. Each of these behaviors has a runtime dynamically adjustable focus of attention, adjusted according to the variation of the agent s affective state. The focus of each behavior is divided into a qualitative focus, which is responsible for the quality of the perceived data, and a quantitative focus, which is responsible for the quantity of the perceived data. Thus, the behavior will be able to filter the information sent by the agent sensors, and build a list of perceived elements containing only the information necessary to the agent, according to the context of the behavior that is currently running. Based on the human attention focus, the agent is also dotted of a affective state. The agent s affective state is based on theories of human emotion, mood and personality. This model serves as a basis for the mechanism of continuous adjustment of the agent s attention focus, both the qualitative and the quantative focus. With this mechanism, the agent can adjust its focus of attention during the execution of the behavior, in order to become more efficient in the face of environmental changes. The proposed architecture can be used in a very flexibly way. The focus of attention can work in a fixed way (neither the qualitative focus nor the quantitaive focus one changes), as well as using different combinations for the qualitative and quantitative foci variation. The architecture was built on a platform for BDI agents, but its design allows it to be used in any other type of agents, since the implementation is made only in the perception level layer of the agent. In order to evaluate the contribution proposed in this work, an extensive series of experiments were conducted on an agent-based simulation over a fire-growing scenario. In the simulations, the agents using the architecture proposed in this work are compared with similar agents (with the same reasoning model), but able to process all the information sent by the environment. Intuitively, it is expected that the omniscient agent would be more efficient, since they can handle all the possible option before taking a decision. However, the experiments showed that attention-focus based agents can be as efficient as the omniscient ones, with the advantage of being able to solve the same problems in a significantly reduced time. Thus, the experiments indicate the efficiency of the proposed architecture

Estudo da remoção de compostos orgânicos, benzeno e tolueno, em solução aquosa por processo oxidativo avançado do tipo Fenton

The oil and petrochemical industry is responsable to generate a large amount of waste and wastewater. Among some efluents, is possible find the benzene, toluene, ethilbenze and isomers of xilenes compounds, known as BTEX. These compounds are very volatily, toxic for environment and potencially cancerigenous in man. Oxidative advanced processes, OAP, are unconventional waste treatment, wich may be apply on treatment and remotion this compounds. Fenton is a type of OAPs, wich uses the Fenton s reactant, hydrogen peroxide and ferrous salt, to promove the organic degradation. While the Photo-Fenton type uses the Fenton s reactant plus UV radiation (ultraviolet). These two types of OAP, according to literature, may be apply on BTEX complex system. This project consists on the consideration of the utilization of technologies Fenton and Photo-Fenton in aqueous solution in concentration of 100 ppm of BTEX, each, on simulation of condition near of petrochemical effluents. Different reactors were used for each type of OAP. For the analyticals results of amount of remotion were used the SPME technique (solid phase microextraction) for extraction in gaseous phase of these analytes and the gas chromatography/mass espectrometry The arrangement mechanical of Photo-Fenton system has been shown big loss by volatilization of these compounds. The Fenton system has been shown capable of degradate benzene and toluene compounds, with massic percentage of remotion near the 99%.

In vitro basal and metabolism-mediated cytotoxicity of flavonoids

The purpose of this study was to compare the basal cytotoxicity and metabolism-mediated cytotoxicity of kaempferol, quercetin and rutin. McCoy cells were exposed to various concentrations of the flavonols with and without the S9 system. The neutral red uptake assay was used to determine viability after 24 h at 35-37 degrees C. Dose-response curves were established for each flavonol in the presence and absence of external metabolizing systems. Kaempferol and quercetin were cytotoxic and provoked a dose-dependent decrease in cell viability, without the S9 system. The hepatic S9 microsomal fraction metabolized these compounds to less cytotoxic metabolites. In contrast, rutin at 500 mu g/ml failed to produce any overt signs of toxicity in either assay. (c) 2005 Elsevier Ltd. All rights reserved.

A Proposal for System Performance Evaluation for an ERP Knowledge Extraction Model

Much has been researched and discussed in the importance played by knowledge in organizations. We are witnessing the establishment of the knowledge economy, but this "new economy" brings in itself a whole complex system of metrics and evaluations, and cannot be dissociated from it. Due to its importance, the initiatives of knowledge management must be continually assessed on their progress in order to verify whether they are moving towards achieving the goals of success. Thus, good measurement practices should include not only how the organization quantifies its knowledge capital, but also how resources are allocated to supply their growth. Thinking about the aspects listed above, this paper presents an approach to a model for Knowledge extraction using an ERP system, suggesting the establishment of a set of indicators for assessing organizational performance. The objective is to evaluate the implementation of projects of knowledge management and thus observe the general development of the organization.

Structural, electronic structure and magnetic studies of SmFe1-xNixO3 (x <= 0.5)

We present the structural, electronic structure and magnetic studies of Ni doped SmFeO3. The X-ray diffraction (XRD) studies confirm the single phase nature of the samples having orthorhombic Pbnm structure and the unit-cell volume is decreasing with the increase of Ni concentration. X-ray absorption spectroscopy (XAS) studies on O K. Fe L-3.2, Ni L-3.2 and Sm M-5.4 edges of SmFe1-xNixO3 (x <= 0.5) samples along with the reference compounds revealed the homo-valence state of Fe and Ni in these materials. From magnetization studies it has been observed the materials exhibit ferromagnetic and anti-ferromagnetic sub-lattices, which are strongly dependent on the thermo-magnetic state of the system. (C) 2010 Elsevier B.V. All rights reserved.

Educação superior no século XXI e a reforma universitária brasileira

Tomando como referência a evolução e as características do sistema brasileiro de educação superior discute-se neste artigo os fundamentos de uma efetiva reforma da educação superior. Procura-se mostrar que a adequação desse sistema para o enfrentamento dos desafios da sociedade do conhecimento, em um país como o Brasil, deve necessariamente resolver três questões: a modernização do sistema, o efetivo aprimoramento da qualidade da educação brasileira em todos os níveis, graus e modalidades e a democratização do ensino promovendo a inclusão social.

Structural and electrical characterization of semiconducting barium-lead-titanate ceramics

BaTiO3 is usually doped to achieve the temperature stability required by device applications, as well as to obtain a large positive temperature coefficient anomaly of resistivity (PTCR). Uniform distribution of dopants among the submicron dielectric particles is the key for optimal control of grain size and microstructure to maintain a high reliability. The system Ba0.84Pb0.16TiO3 was synthesized from high purity BaCO3, TiO2, PbO oxide powders as raw materials. Sb2O3, MnSO4 and ZnO were used as dopants and Al2O3, TiO2 and SiO2 as grain growth controllers. Phase composition was analyzed by using XRD and the microstructure was investigated by SEM. EDS attached to SEM was used to analyze phase composition specially related to abnormal grain growth. Electrical resistivities were measured as a function of temperature and the PTCR effect characterized by an abrupt increase on resistivity.

Screen printed PLZT thick films prepared from nanopowders

The gap between the bulk materials and thin films can be filled with thick films suitably designed and appropriate processed. Thick films of complex system like lead-lanthanum-zirconium titanate (PLZT) is difficult to produce by simple solid-state reaction keeping compositional homogeneity and optimal grain size distribution. In the present work, PLZT thick films were fabricated by screen-printing technique from nanosized powders obtained through soft chemistry by polymeric precursor method. Thick film paste was obtained by mixing PLZT fine powders and organic vehicle. The upper and bottom electrodes based on Ag-Pd and functional component based on PLZT were screen-printed on alumina substrate and after that annealed in air atmosphere. The powder morphology, microstructure, dielectric and ferroelectric properties of 9.5/65/35 PLZT thick films were analysed. (c) 2007 Elsevier Ltd. All rights reserved.

Studies on the activation of the pre-kininogenin-kininogenin (pre-kallikrein-kallikrein) system by sulfated polysaccharides and kaolin

The activation of pre-kininogenin to kininogenin (pre-kallikrein to kallikrein) is one of the steps in the series of reactions of a complex system, linked also to fibrinolysis and coagulation, that leads to kinin release in plasma (See Cochrane et al., 1976; Wuepper, 1976; Kaplan et al., 1976; Kaplan et al., 1976). For human plasma, a test using kaolin as activator and measuring kallikrein activity with the chromogenic substrate Chromozym PK (Nα-benzoyl-prolyl-phenylalanyl-arginyl-nitroanilide, Pentapharm, Basle) is routinely employed. The purpose of this paper is to further study the mechanism of this activation, by means of different activators and using as inhibitor hexadimethrine bromide (Polybrene). Besides kaolin, sulfated polysaccharides, such as heparin and cellulose sulfate are able to activate pre-kininogenin to kininogenin. Hexadimethrine as expected, inhibited the activation by heparin and also that by cellulose sulfate. The activation by kaolin however followed a different pattern suggesting, at least partially, a different mode of action of this activator. © 1979.

Allocation of the cost of transmission losses in a multimarket framework

The paper addresses the issue of apportioning of the cost of transmission losses to generators and demands in a multimarket framework. Line flows are unbundled using equivalent bilateral exchanges on a DC-network model and allocated to generators and demands. Losses are then calculated based on unbundled flows and straightforwardly apportioned to generators and demands. The proposed technique is particularly useful in a multimarket framework, where all markets have a common grid operator with complete knowledge of all network data, as is the case of the Brazilian electric-energy system. The methodology proposed is illustrated using the IEEE Reliability Test System and compared numerically with an alternative technique. Appropriate conclusions are drawn. © The Institution of Engineering and Technology 2006.

A Harris-Todaro agent-based model to rural-urban migration

The Harris-Todaro model of the rural-urban migration process is revisited under an agent-based approach. The migration of the workers is interpreted as a process of social learning by imitation, formalized by a computational model. By simulating this model, we observe a transitional dynamics with continuous growth of the urban fraction of overall population toward an equilibrium. Such an equilibrium is characterized by stabilization of rural-urban expected wages differential (generalized Harris-Todaro equilibrium condition), urban concentration and urban unemployment. These classic results obtained originally by Harris and Todaro are emergent properties of our model.

Management of vomplex systems: Modeling the biological pest control

The aim of this paper is to study the cropping system as complex one, applying methods from theory of dynamic systems and from the control theory to the mathematical modeling of the biological pest control. The complex system can be described by different mathematical models. Based on three models of the pest control, the various scenarios have been simulated in order to obtain the pest control strategy only through natural enemies' introduction. © 2008 World Scientific Publishing Company.