Traffic-responsive urban network control using multivariable regulators

The paper presents the philosophy, the aim, the development, the advantages, and the potential shortcomings of the TUC (Traffic-responsive Urban Control) strategy. Based on a store-and-forward modeling approach and using well-known methods of the Automatic Control Theory, the approach followed by TUC designs (off-line) and employs (on-line) a multivariable regulator for traffic-responsive co-ordinated network-wide signal control. Simulation investigations are used to demonstrate the efficiency of the proposed approach. Based on the presented investigations, summarising conclusions are drawn and future work is outlined

Store-and-forward based methods for the signal control problem in large-scale congested urban road networks

The problem of designing network-wide traffic signal control strategies for large-scale congested urban road networks is considered. One known and two novel methodologies, all based on the store-and-forward modeling paradigm, are presented and compared. The known methodology is a linear multivariable feedback regulator derived through the formulation of a linear-quadratic optimal control problem. An alternative, novel methodology consists of an open-loop constrained quadratic optimal control problem, whose numerical solution is achieved via quadratic programming. Yet a different formulation leads to an open-loop constrained nonlinear optimal control problem, whose numerical solution is achieved by use of a feasible-direction algorithm. A preliminary simulation-based investigation of the signal control problem for a large-scale urban road network using these methodologies demonstrates the comparative efficiency and real-time feasibility of the developed signal control methods

A rolling-horizon quadratic-programming approach to the signal control problem in large-scale congested urban road networks

The paper investigates the efficiency of a recently developed signal control methodology, which offers a computationally feasible technique for real-time network-wide signal control in large-scale urban traffic networks and is applicable also under congested traffic conditions. In this methodology, the traffic flow process is modeled by use of the store-and-forward modeling paradigm, and the problem of network-wide signal control (including all constraints) is formulated as a quadratic-programming problem that aims at minimizing and balancing the link queues so as to minimize the risk of queue spillback. For the application of the proposed methodology in real time, the corresponding optimization algorithm is embedded in a rolling-horizon (model-predictive) control scheme. The control strategy’s efficiency and real-time feasibility is demonstrated and compared with the Linear-Quadratic approach taken by the signal control strategy TUC (Traffic-responsive Urban Control) as well as with optimized fixed-control settings via their simulation-based application to the road network of the city centre of Chania, Greece, under a number of different demand scenarios. The comparative evaluation is based on various criteria and tools including the recently proposed fundamental diagram for urban network traffic

Evaluación de productos bioestimulantes para el control de Phytophthora capsici en Pimiento

Los bioestimulantes de plantas son productos que "contienen sustancias y/o microorganismos cuya función cuando se aplican a las plantas o la rizosfera es estimular los procesos naturales para mejorar/beneficiar la absorción de nutrientes, la eficiencia de nutrientes, la tolerancia al estrés abiótico y la calidad del cultivo (EBIC, 2012). Con el objetivo de cumplir con las regulaciones legales de la Unión Europea, una empresa de protección de cultivos facilitó una selección de productos bioestimulantes para determinar su posible fungitoxicidad y eficacia en el control de oomicetos. Estos productos se han preparado comercialmente para el control de las enfermedades causadas por Phytophthora. Los componentes de su formulación están codificados como L01-L13 y los bioestimulantes como A y B. En este estudio, titulado 'Evaluación de productos bioestimulantes para el control de Phytophthora capsici en pimiento', los productos y los componentes de su formulación se estudiaron in vitro y mediante ensayos de invernadero. En los experimentos in vitro se estudió la posible fungitoxicidad frente a los organismos fitopatógenos P. capsici y P. citrophthora, Fusarium solani, Verticillium dahliae, así como Alternaria alternata. Los patógenos se expusieron a diferentes concentraciones de producto y los resultados de la inhibición del crecimiento se analizaron mediante curvas dosis-respuesta y, cuando fue posible, se calcularon también los valores de EC50 (concentración efectiva media). L01-L13 no indujeron en ningún caso una reducción del 50% del crecimiento de los organismos. Lo mismo ocurrió con los bioestimulantes A y B. Los resultados del estudio in vitro indican que ninguno de estos dos productos, ni los componentes de su formulación, resultaron fungitóxicos para los organismos incluidos en el experimento. Los ensayos de invernadero tuvieron como objetivo evaluar la eficacia de los productos A y B para el control de P. capsici en pimiento. Las plántulas se cultivaron durante dos meses y se pulverizaron foliarmente con los productos. Posteriormente se inocularon con P. capsici mediante inmersión de las raíces en una suspensión de zoosporas. La severidad de la enfermedad se evaluó semanalmente hasta la muerte de las plántulas. Los datos de severidad se analizaron mediante modelos de regresión ordinal, calculando los correspondientes odds ratios con las plantas inoculadas no tratadas como nivel de referencia. Todos los productos evaluados presentaron odds ratios entre 0 y 1, concluyendo que ninguno ellos fue efectivo para el control de P. capsici en pimiento bajo las condiciones del experimento. El posible efecto de control de estos productos habría quedado enmascarado por un estrés excesivo de la plantas, inducido por las condiciones extremadamente agresivas de la inoculación, unido a posibles problemas de fitotoxicidad. Por lo tanto, en el futuro sería necesario explorar otras metodologías para evaluar la eficacia de los bioestimulantes A y B en el control de P. capsici en pimiento.Plant biostimulants are products which ¿contain substance(s) and/or micro-organisms whose function when applied to plants or the rhizosphere is to stimulate natural processes to enhance/benefit nutrient uptake, nutrient efficiency, tolerance to abiotic stress, and crop quality¿ (EBIC, 2012). Aiming to comply with the legislative regulations of the European Union, a plant protection company submitted a selection of biostimulating products to studies of fungitoxicity and oomycete control efficacy. These products are aimed for the control of Phytophthora diseases. The product components were coded L01-L13 and the biostimulants A and B. In this investigation, titled `Evaluation of biostimulant products for the control of Phytophthora capsici in pepper¿, the products themselves as well as their formulation components were studied in vitro and through greenhouse trials. The in vitro experiments involved the target oomycetes P. capsici and P. citrophthora, the soil-borne fungi Fusarium solani and Verticillium dahliae as well as the foliar fungal pathogen Alternaria alternata. The pathogens were exposed to different product concentrations and the results of growth inhibition were analyzed by dose-response curves and, wherever possible, EC50 values (half maximal effective concentration) were calculated. None of the product components (L01-L13) reached an effect of 50% growth reduction. The same was true for biostimulants A and B, and since the results were significant, these products and their components were not considered fungitoxic to the organisms of the study. The greenhouse trials were conducted in parallel and aimed at evaluating the efficacy of products A and B in preventing P. capsici from infecting pepper seedlings. Seedlings were grown for two months, were foliarly sprayed with the products and were subsequently inoculated with P. capsici by root submersion in a zoospore suspension. Disease severity was assessed weekly, until seedling death, and the data were analyzed through ordinal regression models and the calculation of odds ratios. The comparisons were done using inoculated non-treated plants as the reference group. All odds ratios ranged from 0 to 1 suggesting that none of the products achieved to significantly increase the chances of disease control under the conditions tested. It is speculated that the potential benefits of the products against disease were masked by the negative impact that inoculation aggressiveness and phytotoxicity had on plant status. Thus, exploring other methodologies in future trials will be the next step in investigating the topic further and achieving a comprehensive understanding of the efficacy and capacity that biostimulants A and B have in preventing pepper infection from P. capsici.Diakaki, M. (2018). Evaluación de productos bioestimulantes para el control de Phytophthora capsici en Pimiento. Universitat Politècnica de València. http://hdl.handle.net/10251/11365

Φυτοχημική μελέτη του ελληνικού ενδημικού φυτού Inula subfloccosa Rech. f. (Asteraceae)

Στα πλαίσια της παρούσας μεταπτυχιακής εργασίας, εξετάστηκε η χημική σύσταση του ενδημικού στην ανατολική Ελλάδα είδους Inula subfloccosa της οικογένειας Asteraceae. Υπέργεια τμήματα της I. subfloccosa, αποξηραμένα και αδρομερώς τεμαχισμένα, εκχυλίστηκαν εξαντλητικά με οργανικούς διαλύτες και το εκχύλισμα που προέκυψε υποβλήθηκε σε σειρά χρωματογραφικών διαχωρισμών. Απομονώθηκαν συνολικά δέκα μεταβολίτες από τους οποίους μέχρι τώρα έχουν ταυτοποιηθεί οι εννέα, οι οποίοι στο σύνολο τους ανήκουν στην κατηγορία των σεσκιτερπενικών λακτονών. Συγκεκριμένα, τέσσερις έχουν σκελετό ευδεσμανίου (ισοαλαντολακτόνη, ιβαλίνη, ασπεριλίνη, ισοτελεκίνη), τέσσερις γουαϊανίου (4α,5α-εποξυ-10α,14Η-1-επι-ινουβισκολίδιο, 1-επι-ινουβισκολίδιο, ινουβισκολίδιο και 1α-υδροξυ-γουαϊα-4(15),11(13)-διεν-8α,12-ολίδιο) και ένας ψευδογουαϊανίου (2-δεσοξυ-4,10-επι-πουλχελίνη). Ο μεταβολίτης 8,1α-υδροξυ-γουαϊα-4(15),11(13)-διεν-8α,12-ολίδιο απομονώθηκε για πρώτη φορά από εκπρόσωπο του γένους, ενώ ο μεταβολίτης 9,2-δεσοξυ-4,10-επι-πουλχελίνη αποτελεί νέο φυσικό προϊόν.The genus Inula L. (Asteraceae) comprises c. 90 species, about 19 of which are native to Europe. They are perennial herbs, rarely shrubs, sometimes with an unpleasant smell. Several Inula species are used as traditional herbal medicines to treat a broad spectrum of disorders, mainly respiratory, digestive, inflammatory, dermatological, as well as microbial infections. Sesquiterpenes, mostly sesquiterpene lactones including eudesmane, guaiane, pseudoguaiane and germacrane derivatives are characteristic components of Inula species, many of which have exhibited a wide range of biological activities, particularly anti-tumor and anti-inflammatory. The chemical profile of Inula subfloccosa Rech. f., an endemic plant of Greece that is restricted to cipolin and marbles, has not been previously studied. Aerial parts of I. subfloccosa were collected during the flowering period. The air-dried plant material was exhaustively extracted with CH2Cl2/MeOH at room temperature and the resulting crude extract was fractionated with a series of chromatographic separations. So far, 9 sesquiterpene lactones have been isolated from the aerial parts of I. subfloccosa. Detailed analyses of 1D and 2D NMR and MS data led to the identification of four eudesmanolides, four guaianolides, and one pseudoguaianolide. Among the isolated compounds, the bioactive metabolites 4α,5α-epoxy-10α,14H-1-epi-inuviscolide and isoalantolactone were the major constituents, whereas the pseudoguainolide derivative is a new natural product

Neutron-induced fission cross section of 234 U measured at the CERN n_TOF facility

The neutron-induced fission cross section of 234U has been measured at the CERN n-TOF facility relative to the standard fission cross section of 235U from 20 keV to 1.4 MeV and of 238U from 1.4 to 200 MeV. A fast ionization chamber (FIC) was used as a fission fragment detector with a detection efficiency of no less than 97%. The high instantaneous flux and the low background characterizing the n-TOF facility resulted in wide-energy-range data (0.02 to 200 MeV), with high energy resolution, high statistics, and systematic uncertainties bellow 3%. Previous investigations around the energy of the fission threshold revealed structures attributed to β-vibrational levels, which have been confirmed by the present measurements. Theoretical calculations have been performed, employing the talys code with model parameters tuned to fairly reproduce the experimental data

A decision support system for the development of voyage and maintenance plans for ships

The waterborne sector faces nowadays significant challenges due to several environmental, financial and other concerns. Such challenges may be addressed, among others, by optimising voyage plans, and diagnosing as early as possible engine failures that may lead to performance degradation. These two issues are addressed by the Decision Support System (DSS) presented herein, which focuses on the operation of merchant ships. For the development of voyage plans, a multicriteria decision problem is developed and handled with the PROMETHE method, while a multivariable control chart is used for the fault diagnosis problem. A MATLAB-based software implementation of the DSS has been developed adopting a modular architecture, while, in order to provide a generic software solution, the required input data are retrieved from dedicated web-services, following specific communication and data exchange protocols

A compact fission detector for fission-tagging neutron capture experiments with radioactive fissile isotopes

In the measurement of neutron capture cross-sections of fissile isotopes, the fission channel is a source of background which can be removed efficiently using the so-called fission-tagging or fission-veto technique. For this purpose a new compact and fast fission chamber has been developed. The design criteria and technical description of the chamber are given within the context of a measurement of the 233U(n, ) cross-section at the n_TOF facility at CERN, where it was coupled to the n_TOF Total Absorption Calorimeter. For this measurement the fission detector was optimized for time resolution, minimization of material in the neutron beam and for alpha-fission discrimination. The performance of the fission chamber and its application as a fission tagging detector are discussed.French NEEDS/NACRE ProjectEuropean Commission within HORIZON2020 via the EURATOM Project EUFRA