A Geant4 based engineering tool for Fresnel lenses

Geant4 is a Monte Carlo radiation transport toolkit that is becoming a tool of generalized application in areas such as high-energy physics, nuclear physics, astroparticle physics, or medical physics. Geant4 provides an optical physics process category, allowing the simulation of the production and propagation of light. Its capabilities are well tailored for the simulation of optics systems namely in cosmic-rays experiments based in the detection of Cherenkov and fluorescence light. The use of Geant4 as an engineering tool for the optics design and simulation of Fresnel lens systems is discussed through a specific example.Comment: 4 pages, 6 figures, Proceedings of the 30th ICRC, International Cosmic Ray Conference 2007, M\'erida, M\'exico, 3-11 July 200

Wine metrics : revealing the volatile molecular feature responsible for the wine like aroma

O vinho é uma matriz complexa composta por uma variedade de aromas provenientes das diferentes interações dos seus variados compostos. Aroma é geralmente associado a compostos voláteis, que resultam da fermentação alcoólica de acordo com a levedura utilizada e condições utilizadas. A grande concorrência do sector está levar os produtores a compreender melhor as expectativas e preferências dos seus consumidores. A motivação desta tese vai ao encontro de uma ferramenta para compreender o aroma “tipo-vinho” levando à seleção de estirpes de S. cerevisiae de acordo com o padrão de voláteis em função dos consumidores. Este trabalho irá fornecer informações sobre a conexão entre o metabolismo da fermentação do vinho e a percepção do aroma vínico. Neste contexto, foram realizadas 3 réplicas de 4 fermentações em um meio sintético, usando diferentes estirpes de levedura em cada fermentação (3 estirpes vínicas: QA23, VL1, ZA e 1 estirpe de cachaça: L328). Os perfis metabólicos das fermentações foram obtidos através de cromatografia gasosa ligada a um detetor de ionização por chama (GC-FID), espectrometria de massa (GC-MS) e cromatografia líquida de alto desempenho (HPLC) de modo a quantificar os compostos. Um estudo sensorial foi usado para avaliar se os consumidores reconheciam o aroma “tipo-vinho” no decorrer das fermentações. Esta estratégia direcionada em conjunto com uma análise não direcionada usando técnicas de análise multivariada como: decomposição singular do valor (SVD) e análise hierárquica de Agrupamentos (HCA), revelou que o aroma “tipo-vinho” das fermentações está relacionada com acetaldeído, acetato de hexilo e ésteres etílicos. A estirpe L328 revelou-se a que apresenta melhores resultados sensoriais e melhor correlação com os compostos responsáveis pelo aroma “tipo-vinho”. Uma análise supervisionada, nomeadamente PLS-R, permitiu a construção de um modelo que prevê os resultados (R2 = 0.8)) sensoriais do aroma “tipo-vinho” pelo padrão aromático. Por fim uma estratégia não direcionada foi usada com os dados de GC-MS pré-processados e análise por SVD. Este método demonstrou distinguir estirpes baseadas na evolução metabólica durante a fermentação, L328 e QA23 revelaram ser facilmente distinguíveis das restantes. No decorrer desta tese foram utilizadas estratégias de quimiometria e bioinformática para o estudo metabólico de fermentações e a possibilidade de uma pré-seleção das estirpes de acordo as características do produto final.Wine represents a variety of aromas that stem from a complex, completely non-linear system of interactions among many hundreds of compounds. Aroma is usually associated with odorous or volatile compounds that result from fermentation. Yeast strain and fermentation conditions are claimed to be the most important factors influencing the aromas produced in wine. The fierce competition is forcing wine producers to understand better the expectations and preferences of their target market so they can produce wines accordingly. The motivation of this thesis is in the line with a tool for yeast strains selection according with the volatiles output giving a better acceptance by the consumers. This work provided insights about the connection between the wine fermentation metabolism and the product “wine-like” aroma perception. In this context were performed 3 replicas of 4 fermentations of a synthetic grape juice with a different S. cerevisae strain on each (3 wine strains: QA23, VL1, ZA and 1 cachaça strain: L328). The metabolic profiles of fermentations were obtained using gas chromatography attached to a flame ionization detector (GC-FID) or to mass spectrometry (GC-MS) and High Performance Liquid Chromatography (HPLC). A sensorial study also was used in order to evaluate the recognition of a “wine-like” aroma. This target approach coupled with unsupervised analysis, namely Singular Value Decomposition (SVD) and Hierarchical Cluster Analysis (HCA), revealed that the “wine-like” aroma key odorants are acetaldehyde, hexyl acetate and ethyl esters. L328 revealed to be the strain with better scores and correlation with the sensorial analysis scores of “wine-like”. A supervised analysis, Partial least squares regression (PLS-R) model, allowed the prediction (R2 = 0.8) of the “wine-like” scores of the samples during fermentation process. Finally, an untargeted metabolomic approach combining GC-MS data preprocessing with SVD was able to distinguish strains based on their metabolic profiles evolution during the fermentation time. L328 and QA23 strains revealed to be easily distinguished from each other and from the couple ZA and VL1. In conclusion this study demonstrated the potential of the use of chemometrics and bioinformatics approaches was explored in the characterization, prediction and classification of metabolic profiles from fermentations and the possibility of selection of the yeast strain according the final product characteristics

Economics of energy storage in a residential consumer context

With the increase of electricity tariffs and thedecreasing costs for distributed generation technologies, moreand more residential consumers are deploying local generationsystems to satisfy their electricity demand in order to reduceoverall cost. Typically, however, a mismatch between electricitygeneration and demand remains. Storage systems enableconsumers to reduce this mismatch by storing locally generatedelectricity for later consumption, instead of feeding excessgeneration into the grid. This paper analyzes the economics ofstorage installations in a residential consumer context. A linearprogram is presented to determine the optimal dispatch, andSimulated Annealing is used to identify the cost minimizingsystem configuration. The developed approach is tested for amulti-family house in Germany

Multifunctional metal-organic frameworks : from academia to industrial applications

After three decades of intense and fundamental research on metal-organic frameworks (MOFs), is there anything left to say or to explain? The synthesis and properties of MOFs have already been comprehensively described elsewhere. It is time, however, to prove the nature of their true usability: technological applications based on these extended materials require development and implementation as a natural consequence of the up-to-known intensive research focused on their design and preparation. The current large number of reviews on MOFs emphasizes practical strategies to develop novel networks with varied crystal size, shape and topology, being mainly devoted to academic concerns. The present survey intends to push the boundaries and summarise the state-of-the-art on the preparation of promising (multi) functional MOFs in worldwide laboratories and their use as materials for industrial implementation. This review starts, on the one hand, to describe several tools and striking examples of remarkable and recent (multi) functional MOFs exhibiting outstanding properties (e.g., in gas adsorption and separation, selective sorption of harmful compounds, heterogeneous catalysis, luminescent and corrosion protectants). On the other hand, and in a second part, it intends to use these examples of MOFs to incite scientists to move towards the transference of knowledge from the laboratories to the industry. Within this context, we exhaustively review the many efforts of several worldwide commercial companies to bring functional MOFs towards the daily use, analysing the various patents and applications reported to date. Overall, this review goes from the very basic concepts of functional MOF engineering and preparation ending up in their industrial production on a large scale and direct applications in society

Multiyear and multi-criteria AC Transmission Expansion Planning model considering reliability and investment costs

One of the major concerns in Power Systems issurely related with their reliability. Long-term expansionplanning studies traditionally use the well-known deterministic"N-1" contingency criterion. However, this criterion is appliedbased on worst-case analyses and the obtained plan mayoriginate over-investments. Differently, probabilistic reliabilityapproaches can incorporate different type of uncertainties thataffect power systems. In this work, a long term multi-criteriaAC Transmission Expansion Planning model was developedconsidering two objectives - the probabilistic reliability indexExpected Energy Not Supplied (EENS) and the investment cost.The Pareto-Front associated with these two objectives wasobtained using Genetic Algorithms and the final solution wasselected using a fuzzy decision making function. This approachwas applied to the IEEE 24 Bus Test System and the resultsensure its robustness and efficiency

Evaluation of the performance of space reduction technique using AC and DC models in Transmission Expansion problems

Transmission Expansion Planning (TEP) is anoptimization problem that has a non-convex and combinatorialsearch space so that several solution algorithms may converge tolocal optima. Therefore, many works have been proposed to solvethe TEP problem considering its relaxation or reducing its searchspace. In any case, relaxation and reduction approaches shouldnot compromise the quality of the final solution. This paper aimsat analyzing the performance of a search space technique using aConstructive Heuristic Algorithm (CHA) admitting that the TEPproblem is then solved using a Discreet Evolutionary ParticleSwarm Optimization (DEPSO). On one hand the reductionquality is performed by analyzing whether the optimal expansionroutes are included in the CHA constrained set and, on the otherhand, the relaxation quality of the DC model is analyzed bychecking if the optimal solution obtained with it violates anyconstraint using the AC model. The simulations were performedusing three different test systems. The results suggest that theproposed CHA provides very good results in reducing the TEPsearch space and that the adoption of the DC model originatesseveral violations if the full AC model is used to model theoperation of the power system

Economic evaluation of combined generation and storage solutions in low voltage Portuguese consumers

This paper presents the results that were obtained inthe scope of a consultancy study developed by INESC TEC for aPortuguese distribution network company to evaluate theinterest of installing storage devices and PV panels in LVinstallations. We conducted simulations for consumers withannual demands of 5000 kWh (Type C consumers) and 7500kWh (Type B consumers). In general, we concluded that theinstallation of storage devices is still of little economic interestgiven the current investment level and the tariffs paid to injectelectricity in the networks. The largest NPV values wereobtained when only installing PV panels in Type B consumers,the larger ones, and selling the surplus energy to the network

StandsSIM-MD: a management driven forest SIMulator

Resource CommunicationAim of the study: The existing stand level forest simulators available in Portugal were not developed with the aim of including up-to-date model versions and were limited in terms of accounting for forest management. The simulators’ platform, sIMfLOR was recently created to implement different growth models with a common philosophy. The objective was developing one easily-updatable, user-friendly, forest management and climate change sensitive simulator capable of projecting growth for the main tree species in Portugal. Area of the study: Portugal. Material and methods: The new simulator was programmed in a modular form consisting of several modules. The growth module integrates different forest growth and yield models (empirical and process-based) for the main wood production tree species in Portugal (eucalypt, stone pine and maritime pine), the management module drives the growth projections along the planning horizon according to a range of forest management approaches and climate (at present only available for eucalypt). Main results: The main result is the StandsSIM-MD Management Driven simulator that overcomes the limitations of the existing stand level simulators. It is a step forward when compared to the models currently available in the sIMfLOR platform covering more tree species, stand structures and stand compositions. It is focused on end-users and it is based on similar concepts regarding the creation of required inputs and generated outputs. Research highlights: — Forest Management Driven simulations approach — Multiple Prescriptions-Per-Stand functionality — StandsSIM-MD can be used to support landowners decisions on stand Forest management — StandsSIM-MD simulations at regional level can be combined with optimization routinesinfo:eu-repo/semantics/publishedVersio

Simulation and Planning of a 3D Spray Painting Robotic System

Nesta dissertação é proposto um sistema robótico 3D de pintura com spray. Este sistema inclui uma simulação realista do spray com precisão suficiente para imitar pintura com spray real. Também inclui um algoritmo otimizado para geração de caminhos que é capaz de pintar projetos 3D não triviais. A simulação parte de CAD 3D ou peças digitalizadas em 3D e produz um efeito visual realista que permite analisar qualitativamente o produto pintado. Também é apresentada uma métrica de avaliação que pontua trajetória de pintura baseada na espessura, uniformidade, tempo e desperdício de tinta.In this dissertation a 3D spray painting robotic system is proposed. This system has realistic spray simulation with sufficient accuracy to mimic real spray painting. It also includes an optimized algorithm for path generation that is capable of painting non trivial 3D designs. The simulation has 3D CAD or 3D scanned input pieces and produces a realistic visual effect that allows qualitative analyses of the painted product. It is also presented an evaluation metric that scores the painting trajectory based on thickness, uniformity, time and waste of paint