12 documents found, page 1 of 2
Facile Access to Structurally Diverse Antimalarial Indoles Using a One-Pot A3 C...
da Silva, Gustavo; Luz, André F. S.; Duarte, Denise; Fontinha, Diana; Silva, Vera L. M.; Almeida Paz, Filipe A.; Madureira, Ana M.; Simões, SandraA multistep and diversity-oriented synthetic route aiming at the A3 coupling/domino cyclization of o-ethynyl anilines, aldehydes and s-amines is described. The preparation of the corresponding precursors included a series of transformations, such as haloperoxidation and Sonogashira cross-coupling reactions, amine protection, desilylation and amine reduction. Some products of the multicomponent reaction underwen...
A self-parametrization framework for meta-heuristics
Santos, André S.; Madureira, Ana M.; Varela, M.L.R.Even while the scientific community has shown great interest in the analysis of meta-heuristics, the analysis of their parameterization has received little attention. It is the parameterization that will adapt a meta-heuristic to a problem, but it is still performed, mostly, empirically. There are multiple parameterization techniques; however, they are time-consuming, requiring considerable computational effort...
In vitro assessment of the synergism between extracts of Zanthoxylum zanthoxylo...
Gonçalves, Marta; Madureira, Ana M.; Catarino, Luís; Monteiro, Ana; Teixeira, GenerosaPurpose: To survive in harsh environments, plants developed functional and metabolic adaptive mechanisms. One of the most relevant defense strategies is the biosynthesis of secondary metabolites, including terpenoids, alkaloids, flavonoids, and phenolics that are accumulated in cellular organelles or secretory structures. Hence, plants are recognized as a valuable source of natural products and for thousands of...
Decision support tool for dynamic scheduling
Ferreirinha, Luís; Santos, André S.; Madureira, Ana M.; Varela, M.L.R.; Bastos, João A.Production scheduling in the presence of real-time events is of great importance for the successful implementation of real-world scheduling systems. Most manufacturing systems operate in dynamic environments vulnerable to various stochastic real-time events which continuously forces reconsideration and revision of pre-established schedules. In an uncertain environment, efficient ways to adapt current solutions ...
Analysis of lot-sizing methods’ suitability for different manufacturing applica...
Florim, Wilson; Dias, Paulo; Santos, Andre S.; Varela, M.L.R.; Madureira, Ana M.; Putnik, Goran D.Goal: The main goal of this research is to analyse the behaviour of a set of ten lot-sizing methods applied to different application scenarios, within the context of more traditional MRP-based manufacturing environments and on JIT/ Kanbans oriented ones.Design/Methodology/Approach: After an extended literature review, a quantitative research method is used to provide a comparative analysis on the performance of...
Model proposal to evaluate the quality of a production planning and control sof...
Gonçalves, Ricardo M.P.; Varela, M.L.R.; Madureira, Ana M.; Putnik, Goran D.; Machado, JoséThe domain of Production Planning and Control, or in a broader sence Production Management has been deserving a special and increasing attention by the companies, which intend to continuously achieve better results through continuous improvement, which also fits in the context of Industry 4.0. Companies tend to implement management systems with the purpose of achieving greater competitiveness and, consequently,...
Collaborative paradigm for single-machine scheduling under just-in-time princip...
Varela, M.L.R.; Madureira, Ana M.; Dantas, Joana D.; Santos, Andre S.; Putnik, Goran D.; Trojanowska, Justyna; Machado, JoséThe problem of sequencing jobs on a single machine to minimize total cost (earliness and tardiness) is nowadays not just important due to traditional concerns but also due to its importance in the context of Collaborative Networked Organizations and Virtual Enterprises, where precision about promptly responses to customers' requests, along with other important requirements, assume a crucial role. In order to pr...
Evaluation of the Simulated Annealing and the Discrete Artificial Bee Colony in...
Santos, Andre S.; Madureira, Ana M.; Varela, Maria Leonilde RochaMeta-Heuristics (MH) are the most used optimization techniques to approach Complex Combinatorial Problems (COPs). Their ability to move beyond the local optimums make them an especially attractive choice to solve complex computational problems, such as most scheduling problems. However, the knowledge of what Meta-Heuristics perform better in certain problems is based on experiments. Classic MH, as the Simulated...
Collaborative framework for dynamic scheduling supporting in networked manufact...
Varela, M.L.R.; Santos, André S.; Madureira, Ana M.; Putnik, Goran D.; Cruz-Cunha, Maria ManuelaScheduling continues to play an important role in manufacturing systems. It enables the production of suitable scheduling plans, considering shared resources between several different products, through several manufacturing environments including networked ones. High levels of uncertainty characterize networked manufacturing environments. Processes have specific and complex requirements and management requisite...
Euphoportlandols A and B, tetracylic diterpene polyesters from Euphorbia portla...
Madureira, Ana M.; Gyemant, Nora; Ascenso, Jose R.; Abreu, Pedro M.; Molnar, Joseph; Ferreira, Maria-Jose U.Two new tetracyclic diterpene polyesters, euphoportlandols A (1) and B (2), have been isolated along with 12 known tetracyclic triterpenes from an acetone extract of Euphorbia portlandica. Their structures were established as 5 alpha, 11 alpha,-14 alpha, 17-tetraacetoxy-3 beta-benzoyloxy-6 beta, 15 beta-dihydroxy-9-oxoseget-8(12)-ene (1) and 5 alpha,11 alpha,14 alpha,17-tetraacetoxy-3 beta-benzoyloxy- 6 beta, 1...