Duarte, Filipe J. S., Snezhana M. Bakalova, Eurico J. Cabrita, and Gil A. Santos. "
Lewis Acid Catalyzed Reactions of Chiral Imidazolidinones and Oxazolidinones: Insights on the Role of the Catalyst."
Journal of Organic Chemistry. 76.17 (2011): 6997-7004.
AbstractThe mechanism proposed by Evans to justify the selectivity obtained in Lewis acid catalyzed Diels-Alder reactions of cyclopentadiene with acyloxazolidinones has been generalized and used in the rationalization of selectivities obtained in many other systems. However, we recently proposed an alternative mechanism, on the basis of open-chain mono- and bicomplexes, that avoids the need for chelates and explains the selectivity obtained by Evans. In this manuscript we apply our proposal to the catalyzed conjugated addition of amines to acylimidazolidinones, reported by Cardillo, and we clearly show that aluminum chelates are not involved in the reaction, as they induce no selectivity, while Cardillo observed high experimental selectivities. Our data equally show that bicomplexes with carbonyl parallel orientation, proposed by Cardillo to justify the experimental selectivity with nonchelating Lewis acids, indeed induce the opposite selectivity and have also to be dismissed. On the other hand, our mechanistic proposal allows for the full rationalization of the data obtained by Cardillo with aluminum, boron, or zinc Lewis acids and supports our previous proposal on DA cycloadditions of dienes to Evans chiral auxiliary derivatives.
Baptista, Pedro V., Gonçalo Doria, Pedro Quaresma, Miguel Cavadas, Cristina S. Neves, Inês Gomes, Peter Eaton, Eulália Pereira, and Ricardo Franco. "
Nanoparticles in Molecular Diagnostics."
Progress in Molecular Biology and Translational Science: Nanoparticles in Translational Science and Medicine. Elsevier, 2011. 427-488.
Fradinho, Andre, Maria Isabel Gomes, and Ana Paula Barbosa-póvoa Optimization of Batteries Sustainable Distribution Network with Reverse Flows. Livro de actas do 15º congresso da APDIO, IO2011. Coimbra, Portugal, 2011.
AbstractOptimized supply chains, both economically as well as environmentally, are significant instruments to be adopted by companies if they want to succeed in the current competitive world. However, without the support of decision tools to help, at least approximately, the integration of these two aspects in the company’s decision making such aim is difficult to reach. The purpose of this study is to develop a mixed integer linear programming model (MILP), which allows the optimization of closed loop supply chains, considering not only economical aspects, but also environmental ones. The model developed was applied to a Portuguese company where their logistic network structure was redesigned.
Gomes, Isabel M., Luis J. Zeballos, Ana P. Barbosa-Povoa, and Augusto Q. Novais. "
Optimization of Closed-Loop Supply Chains under Uncertain Quality of Returns."
21st European Symposium on Computer Aided Process Engineering. Eds. E. Pistikopoulos, M. C. Georgiadis, and A. Kokossis. Vol. 29. 2011. 945-949.
AbstractThe efficient design and operation of supply chains with return flows represent a major optimization challenge, given the high number of factors involved and their intricate interactions. In particular, the quality level of the return products has strong economic and societal implications and depends greatly on the type of product (glass, paper, electronic, oil, etc) and on the degree of consumers’ readiness, frequently promoted by various kinds of awareness raising campaigns. A multi-product multi-period model was previously developed by the authors [1] for the closed-loop supply chain (CLSC) design and planning, where strategic and tactical decisions were comprehensively considered. This model is now being extended to handle the uncertainty related to the quality of the returned products, which at this stage is modeled by a two-stage scenario-based stochastic approach. General strategies to solve optimization problems involving uncertainty tend to exhibit poor computational performance, due to the problem NP-hard complexity, which tends to worsen with the problem size. Therefore and, in addition, a model performance solution enhancement is also being explored. To increase the efficiency of the solution approach, an alternative representation to some of the integer variables employed in the mathematical formulation was developed, which is tested by means of computational experiments being performed on illustrative real sized examples.
Barišić, Ankica, Vasco Amaral, Miguel Goulão, and Bruno Barroca. "
Quality in Use of Domain Specific Languages: a Case Study."
3rd ACM SIGPLAN workshop on Evaluation and Usability of Programming Languages and Tools (PLATEAU 2011). Portland, USA: ACM, 2011. 65-72.
AbstractDomain Specific Languages (DSLs) are claimed to increment productivity, while reducing the required maintenance and programming expertise. In this context, DSLs usability is a key factor for its successful adoption.
In this paper, we propose a systematic approach based on User Interfaces Experimental validation techniques to assess the impact of the introduction of DSLs on the productivity of domain experts. To illustrate this evaluation approach we present a case study of a DSL for High Energy Physics (HEP).
The DSL on this case study, called Pheasant (PHysicist’s EAsy Analysis Tool), is assessed in contrast with a pre-existing baseline, using General Purpose Languages (GPLs) such as C++. The comparison combines quantitative and qualitative data, collected with users from a real-world setting. Our assessment includes Physicists with programming experience with two profiles; ones with no experience with the previous framework used in the project and other experienced.
This work’s contribution highlights the problem of the absence of systematic approaches for experimental validation of DSLs. It also illustrates how an experimental approach can be used in the context of a DSL evaluation during the Software Languages Engineering activity, with respect to its impact on effectiveness and efficiency.
Ramos, Tania Rodrigues Pereira, Maria Isabel Gomes, and Ana Paula Barbosa-póvoa. "
Restructuring service areas and vehicle routes in a recyclable waste collection system."
EurOMA Conference. Cambridge, UK 2011. 1-10.
AbstractThe present work aims to develop a decision supporting tool to help the decision making process related to the planning of waste collection systems. Such systems involve more than one depot and the objective is to define the delimitation of service areas and the vehicles routes. The problem is modelled as a multi-product, multi-depot vehicle routing problem. A hybrid method that combines exact formulations with heuristic procedures is developed and applied to a real recyclable collection system whose managers want to restructure the current service areas as well as the vehicle routes used to collect three types of recyclable materials.
Ramos, Tania Rodrigues Pereira, Maria Isabel Gomes, and Ana Paula Barbosa-póvoa Solving a multi-product, multi-depot vehicle routing problem by a hybrid method. Livro de actas do 15º congresso da APDIO, IO2011. Coimbra, Portugal, 2011.
AbstractThis paper is focused on the delimitation of service areas and on vehicle routes definition in recyclable waste collection systems with more than one depot. Three types of materials have to be collected in separated routes, so the problem is modelled as a multi-product, multi-depot vehicle routing problem. A hybrid method is developed where a MIP solver is embedded inside a heuristic framework. The effectiveness of this method is tested by comparing the results obtained for some test instances when solved only by an exact formulation. The hybrid method is then applied to a medium size problem based on a real recyclable waste collection system.
Hollander, Yoav, Alan Hu, João M. Lourenço, and Ronny Morad. "
Special Session on Debugging."
Hardware and Software: Verification and Testing. Eds. Sharon Barner, Ian Harris, Daniel Kroening, and Orna Raz. Vol. 6504. Lecture Notes in Computer Science, 6504. Springer Berlin / Heidelberg, 2011. 24-28.
AbstractIn software, hardware, and embedded system domains, debugging is the process of locating and correcting faults in a system. Depending on the context, the various characteristics of debugging induce different challenges and solutions. Post-silicon hardware debugging, for example, needs to address issues such as limited visibility and controllability, while debugging software entails other issues, such as the handling of distributed or non-deterministic computation. The challenges that accompany such issues are the focus of many current research efforts. Solutions for debugging range from interactive tools to highly analytic techniques. We have seen great advances in debugging technologies in recent years, but bugs continue to occur, and debugging still encompasses significant portions of the life-cycles of many systems. The session covered state-of-the-art approaches as well as promising new research directions in both the hardware and software domains.
Barbosa, R., N. Lapa, H. Lopes, I. Gulyurtlu, and B. Mendes. "
Stabilization/solidification of fly ashes and concrete production from bottom and circulating ashes produced in a power plant working under mono and co-combustion conditions."
Waste Management. 31.9-10 (2011): 2009-2019.
AbstractTwo combustion tests were performed in a fluidized bed combustor of a thermo-electric power plant: (1) combustion of coal; (2) co-combustion of coal (68.7% w/w), sewage sludge (9.2% w/w) and meat and bone meal (MBM) (22.1% w/w).
Three samples of ashes (bottom, circulating and fly ashes) were collected in each combustion test. The ashes were submitted to the following assays: (a) evaluation of the leaching behaviour; (b) stabilization/solidification of fly ashes and evaluation of the leaching behaviour of the stabilized/solidified (s/s) materials; (c) production of concrete from bottom and circulating ashes. The eluates of all materials were submitted to chemical and ecotoxicological characterizations. The crude ashes have shown similar chemical and ecotoxicological properties. The s/s materials have presented compressive strengths between 25 and 40 MPa, low emission levels of metals through leaching and were classified as non-hazardous materials. The formulations of concrete have presented compressive strengths between 12 and 24 MPa. According to the Dutch Building Materials Decree, some concrete formulations can be used in both scenarios of limited moistening and without insulation, and with permanent moistening and with insulation.
Santana, Nuno Miguel, Maria Isabel Gomes, and Ana Paula Barbosa-povoa Supply Chain Optimization: Application to a real case. Livro de actas do 15º congresso da APDIO, IO2011. Coimbra, Portugal, 2011.
AbstractThe increase focus of companies in clients’ satisfaction, independently of the market they operate in, results from a growing degree of consumers expectations. To fulfill such increase, companies have to arm themselves with the correct internal capabilities, achieving not only efficacy in the satisfaction of each customer, but also efficiency, by operating at the lower possible cost. One of those internal capabilities is the logistics network, which is representing, more and more, a great challenge for companies, given the complexity of the variables that compose it. In this paper, an optimization model is developed that contemplates simultaneously the design and planning of supply chains with reversed flows, through a multi-period and a multi-product network. The proposed model acts as a support tool for the decisions to be made in a real case of a Portuguese telecommunications company, in order to optimize its logistics network.
Carvalho, H., A. P. Barroso, V. H. Machado, S. G. Azevedo, and V. Cruz-Machado. "
Supply chain resilience: a simulation study."
Annals of DAAAM for 2011 & Proceedings of the 22nd International DAAAM Symposium. Ed. Katalinc} {Branko. Viena, Austria: DAAAM International, 2011. 1611-1612.
AbstractThis paper aims to analyze the supply chain behavior when subject to disturbances using a simulation-based approach. The disturbance explored in this study is the transportation interruption between two suppliers in the automotive supply chain. The performance of the different supply chain entities is used to analyze supply chain design scenarios. The analysis of the outputs simulation study shows that even when a redundancy strategy is used, the negative effects of a disturbance are spread along the supply chain, but the resilience of supply chain entities is enhanced
Martins, Rui M. S., F. Beckmann, R. Castanhinha, R. Araújo, O. Mateus, and P. K. Pranzas Tomographic techniques for the study of exceptionally preserved dinosaur and crocodile fossils from the mesozoic of Portugal. VII Encontro Nacional de Biologia Evolutiva, Coimbra, 21 Dezembro 2011., 2011.
AbstractPortugal is ranked within the ten countries with more dinosaur taxa and the Lourinhã Formation is known
by the Late Jurassic findings of dinosaurs and other fossils. Often, studies of the external morphological
characteristics of the fossils are not sufficient and, observations of internal structures, using non-
destructive techniques, are required. The fossils here presented belong to the Museum da Lourinhã
(Portugal) and comprise a lower jaw of a basal crocodilian (possibly a Tomistomidae), eggshells and
several vertebrae from the exceptionally well preserved in ovo remains of Late Jurassic theropod dinosaur
Lourinhanosaurus. Neutron Tomography (NT) experiments with this material has been carried out at the
Geesthacht Neutron Facility in Germany. Additionally, eggshell fragments and several vertebrae have
been studied by Synchrotron-Radiation based Micro-Computed Tomography (SRμCT) at the HARWI II and
BW2 beamlines, respectively. These beamlines are operated by the Helmholtz-Zentrum Geesthacht at the
storage ring DORIS III at the Deutsches Elektronen–Synchrotron DESY in Hamburg, Germany. In both cases
(NT and SRμCT) complete 3D recordings have been obtained using a non-destructive procedure. The high-
quality tomographic datasets can be effectively studied through interactive digital visualization. Hence,
these visualization methods provide precious information about the 3D internal micro morphology of
fossils, like the network of the eggshell pores, often invisible in more traditional techniques, and provide a
direct window into the evolutionary history of organisms.