Lean na gestão de fluxos logísticos da Dorel Portugal, Lda.

O presente trabalho debruça-se sobre a análise de fluxos de informação e materiais na empresa Dorel Portugal, Lda.. Mais concretamente, são analisados os fluxos de transmissão de informação e os fluxos de movimentação de materiais nos duais fornecedores/armazém e armazém/setor de montagem. O estudo referido terá como propósito a identificação de elementos, associados ao estado atual, passíveis e/ou carentes de melhoria. Identificados e nomeados os pontos de intervenção, desenvolvem-se propostas de solução, as quais assentam predominantemente nos princípios e ferramentas que se associam à filosofia Lean. A escolha desta filosofia, para fundamentação de propostas, prende-se com o facto de a mesma assentar numa lógica de criação de valor pela melhoria de processo, o que espelha bem a intensão subjacente a este exercício. Foram implementadas as sugestões apresentadas e validadas junto da entidade alvo de estudo. No seguimento das implementações realizadas foi executada uma análise que permite enaltecer o ganho, seja de forma quantitativa ou qualitativa, a fim de criar impacto e sensibilizar para a importância das ações executadas. Para finalizar, importa demarcar a criação de um plano de controlo, contemplado nas ações levadas a cabo, o qual é direcionado para a manutenção do processo e concretização de medidas de melhoria contínua.

Project, modelling and simulation of air stripping columns for the treatment of groundwater contaminated with volatile organic compounds

Volatile organic compounds are a common source of groundwater contamination that can be easily removed by air stripping in columns with random packing and using a counter-current flow between the phases. This work proposes a new methodology for the column design for any particular type of packing and contaminant avoiding the necessity of a pre-defined diameter used in the classical approach. It also renders unnecessary the employment of the graphical Eckert generalized correlation for pressure drop estimates. The hydraulic features are previously chosen as a project criterion and only afterwards the mass transfer phenomena are incorporated, in opposition to conventional approach. The design procedure was translated into a convenient algorithm using C++ as programming language. A column was built in order to test the models used either in the design or in the simulation of the column performance. The experiments were fulfilled using a solution of chloroform in distilled water. Another model was built to simulate the operational performance of the column, both in steady state and in transient conditions. It consists in a system of two partial non linear differential equations (distributed parameters). Nevertheless, when flows are steady, the system became linear, although there is not an evident solution in analytical terms. In steady state the resulting system of ODE can be solved, allowing for the calculation of the concentration profile in both phases inside the column. In transient state the system of PDE was numerically solved by finite differences, after a previous linearization.

A New Approach in the Design of Air Stripping Columns for the Treatment of Groundwater Contaminated With Volatile Organic Compounds

Volatile organic compounds are a common source of groundwater contamination that can be easily removed by air stripping in columns with random packing and using a counter-current flow between the phases. This work proposes a new methodology for column design for any type of packing and contaminant which avoids the necessity of an arbitrary chosen diameter. It also avoids the employment of the usual graphical Eckert correlations for pressure drop. The hydraulic features are previously chosen as a project criterion. The design procedure was translated into a convenient algorithm in C++ language. A column was built in order to test the design, the theoretical steady-state and dynamic behaviour. The experiments were conducted using a solution of chloroform in distilled water. The results allowed for a correction in the theoretical global mass transfer coefficient previously estimated by the Onda correlations, which depend on several parameters that are not easy to control in experiments. For best describe the column behaviour in stationary and dynamic conditions, an original mathematical model was developed. It consists in a system of two partial non linear differential equations (distributed parameters). Nevertheless, when flows are steady, the system became linear, although there is not an evident solution in analytical terms. In steady state the resulting ODE can be solved by analytical methods, and in dynamic state the discretization of the PDE by finite differences allows for the overcoming of this difficulty. To estimate the contaminant concentrations in both phases in the column, a numerical algorithm was used. The high number of resulting algebraic equations and the impossibility of generating a recursive procedure did not allow the construction of a generalized programme. But an iterative procedure developed in an electronic worksheet allowed for the simulation. The solution is stable only for similar discretizations values. If different values for time/space discretization parameters are used, the solution easily becomes unstable. The system dynamic behaviour was simulated for the common liquid phase perturbations: step, impulse, rectangular pulse and sinusoidal. The final results do not configure strange or non-predictable behaviours.

Microteatro : o teatro rápido : dissertação

Dissertação submetida à Escola Superior de Teatro e Cinema para cumprimento dos requisitos necessários à obtenção do grau de Mestre em Teatro - especialização em Artes Performativas

Gestão de stocks e armazém de matérias-primas

Relatório de Estágio apresentado ao Instituto Politécnico do Porto para obtenção do Grau de Mestre em Logística Orientadores do Instituto: Professor Doutor Luís Barreto e Mestre Jonas Lima Orientador da empresa: Engenheiro Vítor Carvalho

O Impacto do investimento direto estrangeiro no crescimento económico de Angola

Dissertação apresentada ao Instituto Superior de Contabilidade e Administração do Porto, para a obtenção do Grau de Mestre em Empreendedorismo e Internacionalização Orientação: Prof. Doutora Maria Clara Dias Pinto Ribeiro Prof. Doutora Celsa Maria Carvalho Machado

Management Driven Hybrid Multicast Framework for Content Aware Networks

The need for better adaptation of networks to transported flows has led to research on new approaches such as content aware networks and network aware applications. In parallel, recent developments of multimedia and content oriented services and applications such as IPTV, video streaming, video on demand, and Internet TV reinforced interest in multicast technologies. IP multicast has not been widely deployed due to interdomain and QoS support problems; therefore, alternative solutions have been investigated. This article proposes a management driven hybrid multicast solution that is multi-domain and media oriented, and combines overlay multicast, IP multicast, and P2P. The architecture is developed in a content aware network and network aware application environment, based on light network virtualization. The multicast trees can be seen as parallel virtual content aware networks, spanning a single or multiple IP domains, customized to the type of content to be transported while fulfilling the quality of service requirements of the service provider.

The Farol Deposit (Depósito do Farol) – a Pleistocene beach deposit from Cape Mondego (Figueira da Foz, West Central Portugal)*

Among the Pleistocene and Holocene units recorded near the marine cliffs of Cape Mondego (Figueira da Foz, West Central Portugal) stands out the Farol Deposit (Depósito do Farol), at an altitude of ±95 m above present sea level. It is a marine terrace with three exposures of interstratified conglomerates and sands, overlapped by calclititic-fanglomerates. This sedimentary setting indicates that deposition took place in a seashore environment influenced by the proximity of a marine palaeocliff. The deposit has an interesting subfossil fauna with abraded and fragmented shells of Nucella lapillus (LINNÉ, 1758), Patella vulgata (LINNÉ, 1758) and Littorina littorea (LINNÉ, 1758), suggesting the existence of an environment with colder surface seawater, when compared with the present day Portuguese seashore. These specimens belonged to marine communities adapted to live in intertidal rocky platforms, which have been exposed to the cyclic action of waves and tidal flows, on the swash and surf zones. The Farol Deposit can be related to an Early/Middle Pleistocene “cold-water” episode, earlier to the Isotopic Stages 7 and 11. This episode occurred before the deposition of the units Quiaios Sands (Areias de Quiaios) and Cantanhede Sands (Areias de Cantanhede) (Sicilian?), but later than the Arazede Sands (Areias de Arazede) and Marinha das Ondas Sands (Areias de Marinha das Ondas) (Early Pleistocene).

Inferência de percursos dos utentes de um transporte coletivo

Trabalho Final de Mestrado para obtenção do grau de Mestre em Engenharia de Redes de Comunicações e Multimédia

Dynamic cluster scheduling for cluster-tree WSNs

While Cluster-Tree network topologies look promising for WSN applications with timeliness and energy-efficiency requirements, we are yet to witness its adoption in commercial and academic solutions. One of the arguments that hinder the use of these topologies concerns the lack of flexibility in adapting to changes in the network, such as in traffic flows. This paper presents a solution to enable these networks with the ability to self-adapt their clusters’ duty-cycle and scheduling, to provide increased quality of service to multiple traffic flows. Importantly, our approach enables a network to change its cluster scheduling without requiring long inaccessibility times or the re-association of the nodes. We show how to apply our methodology to the case of IEEE 802.15.4/ZigBee cluster-tree WSNs without significant changes to the protocol. Finally, we analyze and demonstrate the validity of our methodology through a comprehensive simulation and experimental validation using commercially available technology on a Structural Health Monitoring application scenario.

A conceptual model for sheet-flow drawn from rapid granular flow theories

33rd IAHR Congress: Water Engineering for a Sustainable Environment

TRFS: desenvolvimento de um protótipo para simulação microscópica de tráfego

Dissertação para obtenção do grau de Mestre em Engenharia Civil na Área de Especialização de Vias de Comunicação e Transportes

Impact of europeanization in policy network governance pattrons

Comunicação apresentada na 30th Sunbelt Social Networks Conference, em Riva del Garda, Itália, a 3 de Julho de 2010.

The insular shelves of the Faial-Pico Ridge (Azores archipelago): a morphological record of its evolution

Shelves surrounding reefless volcanic ocean islands are formed by surf erosion of their slopes during changing sea levels. Posterosional lava flows, if abundant, can cross the coastal cliffs and fill partially or completely the accommodation space left by erosion. In this study, multibeam bathymetry, high-resolution seismic reflection profiles, and sediment samples are used to characterize the morphology of the insular shelves adjacent to Pico Island. The data show offshore fresh lava flow morphologies, as well as an irregular basement beneath shelf sedimentary bodies and reduced shelf width adjacent to older volcanic edifices in Pico. These observations suggest that these shelves have been significantly filled by volcanic progradation and can thus be classified as rejuvenated. Despite the general volcanic infilling of the shelves around Pico, most of their edges are below the depth of the Last Glacial Maximum, revealing that at least parts of the island have subsided after the shelves formed by surf erosion. Prograding lava deltas reached the shelf edge in some areas triggering small slope failures, locally decreasing the shelf width and depth of their edges. These areas can represent a significant risk for the local population; hence, their identification can be useful for hazard assessment and contribute to wiser land use planning. Shelf and subaerial geomorphology, magnetic anomalies and crustal structure data of the two islands were also interpreted to reconstruct the long-term combined onshore and offshore evolution of the Faial-Pico ridge. The subaerial emergence of this ridge is apparently older than previously thought, i.e., before approximate to 850 ka.

Magma flow pattern in dykes of the Azores revealed by ansiotropy of magnetic susceptibility

The localization of magma melting areas at the lithosphere bottom in extensional volcanic domains is poorly understood. Large polygenetic volcanoes of long duration and their associated magma chambers suggest that melting at depth may be focused at specific points within the mantle. To validate the hypothesis that the magma feeding a mafic crust, comes from permanent localized crustal reservoirs, it is necessary to map the fossilized magma flow within the crustal planar intrusions. Using the AMS, we obtain magmatic flow vectors from 34 alkaline basaltic dykes from São Jorge, São Miguel and Santa Maria islands in the Azores Archipelago, a hot-spot related triple junction. The dykes contain titanomagnetite showing a wide spectrum of solid solution ranging from Ti-rich to Ti-poor compositions with vestiges of maghemitization. Most of the dykes exhibit a normal magnetic fabric. The orientation of the magnetic lineation k1 axis is more variable than that of the k3 axis, which is generally well grouped. The dykes of São Jorge and São Miguel show a predominance of subhorizontal magmatic flows. In Santa Maria the deduced flow pattern is less systematic changing from subhorizontal in the southern part of the island to oblique in north. These results suggest that the ascent of magma beneath the islands of Azores is predominantly over localized melting sources and then collected within shallow magma chambers. According to this concept, dykes in the upper levels of the crust propagate laterally away from these magma chambers thus feeding the lava flows observed at the surface.