Setting the optimal sheet thickness distribution for plastics thermoforming by multi-objective optimization

Thermoforming is a thermoplastic processing technique commonly used in the rigid packaging industry. The process comprises a heating stage, which aims at allowing the sheet to acquire the required deformability, a deformation stage, in which the sheets conform to the mould surface, and, finally, a cooling stage, which allows the part to be extracted from the mould without distorting. Since there are several processing variables associated with those stages, optimizing the thermoforming process is a complex task. In this work, a multi-objective optimization evolutionary algorithm is proposed to optimize the plastics thermoforming process. For that purpose, the thickness distribution of the final part was optimized considering that it is manufactured from uniform temperature sheets with different thickness distributions, such as constant and spline and concentric profiles. The aims were to minimize the sheet volume, as it implies less material use; assure a minimum value for the part thickness distribution, to avoid hindering its mechanical behavior; and minimize the thickness heterogeneity, i.e., the difference between the thickness of the part and a reference thickness. The Pareto optimal solutions found by the algorithm correspond to different thickness profiles for the three different sheet shapes. In all cases, an improvement of the different profiles along the successive generations of the evolutionary algorithm was obtained, which are related to the objectives considered. Moreover, the initial sheet thickness distribution was found to clearly influence the optimization process. The results obtained for these three different initial sheet shapes indicate that the proposed methodology is valid, providing solutions with physical meaning and with great potential to be applied in more complex cases

Automatic control system for an oil-hydraulic actuator of a scissor lift

Lifting equipment’s have the purpose to lift goods within their safe working load and design rules specified in standards. However, some applications require additional care regarding handling the load when this care is out of the standard’s specifications. This paper presents the control and supervision system development of a scissor lift table, which should ensure, during its motion, that the vertical speed is constant. This lift table is working alongside a system for handling boxes composed by 3 entry conveyors and 1 exit conveyor. In this work, it was carried out the study of the direct and inverse kinematics to obtain the equations of position, speed and force for the oil-hydraulic actuator and the applicability of Denavit-Hartenberg’s algorithm for these equations. It was proposed a hydraulic circuit, with the selection of the main hydraulic components and the design of the oil-hydraulic actuator (a cylinder) with the magnetostrictive transducer as well. A programmable logical controller was selected, as well as the sensors and actuators for the conveyor system and a program was developed which allows to automatically control the system. The lift table’s velocity control is done by equations which define an oil flow profile of the hydraulic cylinder, which ensures a constant vertical speed of the lift table. To improve the control of the system, initial and final flow ramps were added to the equations, with reduced oil flow at the target height. It was observed that the use of Denavit-Hartenberg’s algorithm revealed to be limited, on which it was necessary to use other calculation methods to obtain the equations of speed and force. However, the proposed oil-hydraulic circuit, as well as the developed speed control, allow the control of the lift table’s position and speed.info:eu-repo/semantics/publishedVersio

Multi-objective optimization of plastics thermoforming

The practical application of a multi-objective optimization strategy based on evolutionary algorithms was proposed to optimize the plastics thermoforming process. For that purpose, in this work, differently from the other works proposed in the literature, the shaping step was considered individually with the aim of optimizing the thickness distribution of the final part originated from sheets characterized by different thickness profiles, such as constant thickness, spline thickness variation in one direction and concentric thickness variation in two directions, while maintaining the temperature constant. As far we know, this is the first work where such a type of approach is proposed. A multi-objective optimization strategy based on Evolutionary Algorithms was applied to the determination of the final part thickness distribution with the aim of demonstrating the validity of the methodology proposed. The results obtained considering three different theoretical initial sheet shapes indicate clearly that the methodology proposed is valid, as it provides solutions with physical meaning and with great potential to be applied in real practice. The different thickness profiles obtained for the optimal Pareto solutions show, in all cases, that that the different profiles along the front are related to the objectives considered. Also, there is a clear improvement in the successive generations of the evolutionary algorithm.This research was funded by NAWA-Narodowa Agencja Wymiany Akademickiej, under grant PPN/ULM/2020/1/00125 and European Union’s Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie Grant Agreement No 734205–H2020-MSCA-RISE2016. The authors also acknowledge the funding by FEDER funds through the COMPETE 2020 Programme and National Funds through FCT (Portuguese Foundation for Science and Technology) under the projects UID-B/05256/2020, UID-P/05256/2020, UIDB/00319/2020, MORPHING.TECH— Direct digital Manufacturing of automatic programmable and Continuously adaptable patterned surfaces with a discrete and patronized composition (POCI-01-0247-FEDER-033408)

Adequação da técnica de massa específica na diferenciação de diplóides e poliplóides de Musa acuminata Cola.

A duplicação cromossômica de diplóides, com a produção de autotetraplóides, é uma técnica que vem sendo usada no melhoramento genético de bananeira para obtenção de triplóides secundários. Mediante cruzamento desses tetraplóides com diplóides melhorados (Silva et al., 2005). Desta forma é possível, produzir híbridos com boas características agronômicas e resistentes a pragas que podem ser recomendados como novas cultivares (Bakry et al., 2007).Vários são os fatores que podem determinar o sucesso da poliploidização em bananeira, dentre eles destaca-se o uso de técnicas práticas e seguras para identificação dos poliplóides putativos. Dentre essas, são usadas a citometria de fluxo, estudo da estrutura de estômatos e contagem de cromossomos (Ganga & Chezhiyan, 2002; Bakry et al., 2007; Dolezel, 2007).A pré-seleção de indivíduos tratados com antimitótico é uma prática, que se observou necessária para redução do número de indivíduos que necessitam ter a ploidia confirmada por citometria ou outros métodos. A pré-seleção é feita na fase de aclimatização e baseia-se em características morfológicas e ou estruturais, como espessura das folhas, uma vez que, os tetraplóides normalmente são plantas vigoras e com folhas mais espessas. Plantas com folhas mais espessas podem ser identificadas por pessoas treinadas por meio do tato. A espessura foliar pode ser medida por vários métodos e de forma indireta, com base na massa de discos foliares.O trabalho teve por objetivo estimar a espessura foliar, com base no peso de discos foliares de genótipos com diferentes ploidias.pdf 252

Comparative ecology of the European eel, Anguilla anguilla (L.1758), in a large Iberian river

A total of 1,816 eels were sampled in 1988, from seven sampling areas. Four areas were located in brackish water and the remaining three were located in freshwater reaches of the Tagus river basin. Eels were more abundant in the middle estuary and decreased both in the upstream and in the downstream directions, with a predominance of males in higher density areas. Smaller individuals preferred more peripheral areas, such as margins and upper reaches in the brackish water zone, and the tributaries of the freshwater habitats. It was assumed that this distribution pattern resulted from three main factors: (i) the dominance of larger specimens; (ii) the need to avoid predators and; (iii) the search for better trophic conditions. The condition of the individuals generally decreased toward the upper reaches, apparently due to a corresponding decrease in feeding intensity. The presence of the Belver dam in the main river, 158 km upstream from the sea, seemed to impose major alterations to the described patterns. The concentration of specimens below this impassable obstacle yielded a reduction in the proportion of females and a decrease in the condition and survival of the eels, contributing to a reduction in the spawning success of this population. Suggestions to diminish the effects of the dam, and to preserve the fishery are also presente

Measurement of the Z/gamma* + b-jet cross section in pp collisions at 7 TeV

The production of b jets in association with a Z/gamma* boson is studied using proton-proton collisions delivered by the LHC at a centre-of-mass energy of 7 TeV and recorded by the CMS detector. The inclusive cross section for Z/gamma* + b-jet production is measured in a sample corresponding to an integrated luminosity of 2.2 inverse femtobarns. The Z/gamma* + b-jet cross section with Z/gamma* to ll (where ll = ee or mu mu) for events with the invariant mass 60 < M(ll) < 120 GeV, at least one b jet at the hadron level with pT > 25 GeV and abs(eta) < 2.1, and a separation between the leptons and the jets of Delta R > 0.5 is found to be 5.84 +/- 0.08 (stat.) +/- 0.72 (syst.) +(0.25)/-(0.55) (theory) pb. The kinematic properties of the events are also studied and found to be in agreement with the predictions made by the MadGraph event generator with the parton shower and the hadronisation performed by PYTHIA.Comment: Submitted to the Journal of High Energy Physic

ESPON Italian evidence in changing Europe

Il volume, che rientra nelle attività dell’ESPON Contact Point Italia, accoglie i risultati del contributo dei Partner Italiani allo sviluppo dei progetti del Programma ESPON 2013, acronimo di European Observation Network for Territorial Development and Cohesion. I testi sintetizzano ed evidenziano, tra l’altro, le relazioni con le politiche di sviluppo regionale dell’Italia, inserendole in un quadro di cooperazione transnazionale che coinvolge 28 + 4 paesi dell’Unione europea. Affrontando aspetti della politica territoriale europea che spaziano dall’innovazione e conoscenza all’accessibilità, dal policentrismo alle aree metropolitane, dalla migrazione alla globalizzazione, gli Autori mettono in luce la posizione dell’Italia e delle regioni anche rispetto agli obiettivi fissati da Europe 2020. Uno spazio è dedicato alle esperienze regionali che hanno trovato in ESPON uno stimolo e un’occasione di confronto; come pure ai concetti che sottendono il lessico, i principi di orientamento e i nuovi modelli della pianificazione in Europa; e alle esperienze formative rivolte alle giovani generazioni e ai decision maker Il libro si inquadra nelle iniziative del Semestre di Presidenza Italiana dell’Unione europea ed è cofinanziato dal Ministero delle Infrastrutture e dei Trasporti (MIT) responsabile nazionale del Programma ESPON. E’ rivolto ai ricercatori, agli utilizzatori istituzionali, ai policy maker, ai “practioner” e ai “non specialisti”, tra cui gli studenti, affinché possano fare propri i risultati dell’impegno costante, rigoroso e rispettoso delle diversità territoriali che hanno contraddistinto, dal 2007 ad oggi, il contributo della ricerca, anche sperimentale e applicata, alla crescita della società italiana come parte integrante del sistema europeo. L’Osservatorio ESPON, per chi ancora non lo conosce, può rappresentare un viaggio nel territorio europeo, nelle sue diversità territoriali, economiche, sociali, culturali da integrare e rendere coese, sostenibili, mantenendo e sviluppando potenziali di competitività crescenti e, nel contempo, innovando e diffondendo nuovi modi, metodologie, strumenti e prassi per fare del territorio un bene comune e condiviso. Dati, riferimenti e raccomandazioni politiche utili alla crescita del Paese completano il quadro. Presentazione del Ministro delle Infrastrutture, On. Maurizio Lupi Postfazione del Direttore della Coordination Unit del Programma ESPON, Peter MehlbyeThe book is part of the activities of ESPON Contact Point Italy. It includes the results of the contribution of the Italian partners in the development of projects under the ESPON 2013 Programme, which stands for European Observation Network for Territorial Development and Cohesion. The texts summarise and highlight, among other things, the relations with the regional development policies of Italy, placing them in a framework of transnational cooperation involving the 28 + 4 EU Countries. Addressing aspects of European territorial policy, ranging from innovation and knowledge accessibility, from the polycentrism to metropolitan areas, from migration to globalization, the authors highlight the position of Italy and of regions also in relation to the objectives set by Europe 2020. A place is devoted to the regional experiences that in the ESPON found a stimulus and an opportunity for discussion, as well as to the concepts behind the vocabulary, to the principles of guidance, and new planning models in Europe, and to the training experiences aimed at the younger generations and the decision makers The book forms part of the initiatives of the Italian Presidency of the European Union and is co-financed by the Ministry of Infrastructure and Transportation (MIT) in charge of the national ESPON Programme. It is aimed at researchers, institutional users, policy makers, at "practitioners" and "non-specialists" including students, so that they can make use of the results of the constant and rigorous work also respectful of the territorial diversities that have characterized the experimental and applied research since 2007, so contributing to the growth of Italian society as an integral part of the European system. The ESPON Monitoring Centre, for those who still do not know, can be a journey into the European territory, its territorial, economic, social, cultural diversities to integrate and make cohesive and sustainable, by maintaining and developing the increasing potentials of competitiveness and, at the same time, by innovating and disseminating new ways, methodologies, tools and practices to make the territory a common and shared good. Data, references and useful policy recommendations to the growth of the country are also included in the book. Presentation by the Minister of Infrastructure, Mr. Maurizio Lupi Afterword by the Director of the Coordination Unit ESPON Programme , Peter Mehlby