Estudio de una red aislada de distribución de pequeña potencia y gran penetración eólica con la herramienta PSS/E

El objeto de este proyecto es realizar un análisis de estabilidad ante contingencias en una red aislada de pequeña potencia con alto grado de penetración eólica mediante la herramienta PSS/E con el fin de aportar conocimiento para, posteriormente, definir la forma de operación más adecuada de dicho sistema atendiendo a su eficacia y fiabilidad. La red considerada para el estudio es la de la isla de El Hierro, en el archipiélago de Canarias, donde se tiene previsto abastecer exclusivamente, a toda la isla, combinando la aportación energética de un parque eólico y una central hidráulica con grupos de bombeo. Para realizar los estudios de estabilidad se analizan una serie de escenarios considerados de interés desde el punto de vista técnico, bien sea abasteciendo la demanda con una sola fuente de generación o con varias a la vez. El interés principal de esta red radica en que es una red aislada, de pequeña potencia, por lo que el proceso de integración masiva de energías renovables en la misma presenta una serie de particularidades que se irán detallando a lo largo del trabajo. El modelado de la red se ha realizado utilizando PSS/E, un software comercial extendido para el análisis de los sistemas de potencia. Con el programa se han resuelto los regímenes estáticos de funcionamiento (flujos de cargas) y los dinámicos (estudios de contingencias). Los resultados mostrarán las tensiones o frecuencias en los nudos de interés, observándose cómo cambian los valores en la situación anormal de funcionamiento y cómo se recuperan cuando se despeja la falta considerada, retornándose a los valores que existían en la red previos al fallo. Se pretende concluir cuál debe ser el mínimo de energía convencional que se debe mantener en el sistema para asegurar el suministro de forma fiable y segura en cualquier circunstancia.

Electrochemical Behaviour of PSS-Functionalized Silica Films Prepared by Electroassisted Deposition of Sol–Gel Precursors

Porous, electrically insulating SiO2 layers containing polystyrene sulfonate (PSS) were deposited on glassy carbon electrodes by an electrochemically assisted deposition method. The obtained material was characterized by microscopic, spectroscopic and thermal techniques. Silica-PSS films modify the electrochemical response of the glassy carbon electrodes against selected redox probes. Positively charged species show reduced diffusivities across the SiO2-PSS pores, which resulted in a concentration ratio higher than 1 for these species. The opposite behaviour was found for negatively charged redox probes. These observations can be interpreted in terms of the different affinity of the GC/SiO2-PSS-modified electrode for the electroactive species, as a consequence of the negatively charged porous silica.

Cartografias do invisível : para uma redefinição da serigrafia como meio operativo : a dissimulação da repetição

This dissertation searches for new possibilities into the way of operating with screen printing, as well as its importance in the context of the operational methods of the visual arts, based on a personal project of painting. To this end, we resource to the mapping and the linear drawings of city maps as a way to reflect upon its use in contemporary art. Also, we establish a connection between the way these cities organize themselves and the theories of the rhizome by Gilles Deleuze and Felix Guattari; the cartography and the grids of Rosalind Krauss, with the artistic aim to build screen printing matrixes; and also the function in gesture of making ‘printings’ with the conjectures of Didi-Huberman. We investigate also the consequences of a mode of doing by resourcing to screen printing with respect to the construction of visual metaphors in painting

An interpretation of four regal Psalms (Pss. 2, 110, 45 and 92)

On cover: Quaternio.

Operator, organizational, and direct support maintenance manual : detecting set, mine, aural indication, 10V DC operating power, portable, transistorized, w/case AN/PSS-11 (Polan models P153 and P158) NSN 6665-00-966-9071, (Polan model P190) NSN 6665-00-181-0432, (Oregon Technical Products model MD-M) ... (The VP Company model VP200) ... (Fourdee model 4D5000) ....

Includes index.

Organizational, direct support maintenance, repair parts and special tools list : detecting set, mine, aural indication, 10V DC operating power, portable, transistorized, w/case AN/PSS-11 (Polan models P153 and P158) FSN 6665-966-9071, (Polan model P190) FSN 6665-181-0432, (Oregon Technical Products model MD-M) ...

"23 February 1974."

PSS as a service based strategy for western manufacturers

A product-service system (PSS) is a subtle blend of products and services that are offered as an integrated solution to customers. Much existing work on PSS has originated from Scandinavia and has been motivated by a sustainability agenda. Although valuable, this form has limited appeal to western manufacturers. However, by expanding the concepts of PSS to also embrace leading thinking on large scale complex service systems and informated products and services, it is possible to put forward the basis of a service business model that offers the means to differentiate from competitors who simply offer lower priced products. This paper aims to build this case. It reports the state-of-the-art of PSS, defines the concept, reports on its origin and features, discusses examples of applications, and finally proposes a research strategy for future work on this topic.

Developing a serious game for PSS

Purpose: This paper presents the system architecture of a serious game, which is going to be run in parallel to Rolls Royce tra ining on product-service systems (PSS). Design/methodology/approach: The original game is outlined, requirements for an onl ine version are defined, and the architecture is proposed. Findings: The games approach has proven its value in design for service tra ining but an online version is needed to improve the opportunit ies to deliver the game. Originality/value: Such a system presents opportunities for the acquisition and development of specific professional knowledge, skills, and competencies

Business-IT Alignment in PSS Value Networks: A Capability-Based Framework

Part 8: Business Strategies Alignment

Synthesis of Na-PSS geopolymers and analysis of the H2O/Na2O molar ratio influence over their mechanical properties

Geopolymers are solid aluminosilicate material made by mixing an activating solution and a solid precursor. This work studied the mechanisms of synthesis of metakaolin-based geopolymers and the influence of water content, described by the molar ratio H2O/Na2O, on the final product. The samples were tested using a Uniaxial Compressive Test (UCT) to define their compressive resistance. Two geopolymers series were synthetized and let them rest for 7- days and 28-days, each of them composed by six different sets. 7-day rest series showed that water addition had no relevant effect over its resistance while the 28-day rest series almost doubled the compressive resistance, although those with the highest H2O/Na2O molar ratio showed instead a drastic reduction. Two other series were synthesized by adding silt aggregate, a waste material obtained in the production of aggregate for concrete, corresponding to 10wt% and 20wt%of the metakaolin used. After 28 days of aging, these samples were tested via UCT to measure the variation of the compressive resistance after the silt addition. The aggregate has disruptive effects over the compressive resistance, but the 20wt% samples achieved a higher compressive resistance. Samples with highest and lowest compressive resistance have been chosen to carry out an XRD analysis. In all the samples it has been recognized the presence of Anatase (TiO2), a titanium oxide found in the metakaolin and Thermonatrite, a hydrated sodium carbonate [Na2CO3 • (H2O)]. Scanning Electron Microscopy was carried out on the samples with the highest compressive resistance and showed that the samples with lower water content developed a homogeneous geopolymeric texture, while those with higher water content showed instead a spongy-like texture and a higher air or pore solution bubbles presence. Silt/geopolymer composites showed a fracture system developing across the interstitial transition zone between the geopolymer matrix and the aggregate particle.

Tecnologie e workflow per la digitalizzazione e la visualizzazione immersiva e real time del prodotto tessile

Il settore del mobile è frammentato, caratteristica che non ha mai permesso una completa digitalizzazione dei suoi comparti: la comunicazione è risultata spesso difficoltosa, responsabile di incomprensioni e spesso mancanza di puntualità, con conseguente dispendio di risorse. Nel mio progetto di tesi analizzo principalmente la filiera degli imbottiti e quella tessile, collaterale ad essa. Il target di mio interesse sono le aziende produttrici di arredi che si servono di configuratori per la presentazione dei prodotti ai propri clienti. Ho ipotizzato un workflow suddivisibile in due fasi, una attuabile nel presente ed una seconda che implica una variazione attuabile nel futuro prossimo. Per la prima fase ho studiato un workflow agile al fine di digitalizzare le texture a partire da acquisizioni fotografiche. Analizzando il comportamento di vari tessuti ed elaborando un metodo di riproduzione digitale, ho sperimentato una metodologia per una resa superficiale degli imbottiti accurata e fotorealistica sia su piattaforme web che in realtà aumentata. Lo studio nasce dall’esigenza di apportare migliorie agli attuali configuratori e renderli effettivamente utili al fine per cui sono stati pensati: garantire una semplificazione del processo di acquisto rispondendo alle necessità degli utenti di vedere in anteprima l’aspetto finale del proprio arredo, collocato nello spazio abitativo. Il configuratore che ne deriva, restituirà una visualizzazione fedele dei tessuti anche in realtà aumentata. L’intelligenza artificiale fungerà da supporto nel processo decisionale dell’utente e la scelta dei materiali che compongono l’arredo sarà guidata in maniera tale da generare nell’utente un senso di consapevolezza circa gli impatti sull’ambiente. Per la seconda fase propongo una modalità di creazione dei tessuti completamente digitalizzata, a favore di una filiera sostenibile che riesce in questo modo ad abbattere costi e sprechi, con conseguente risparmio di risorse.

Inverso. Progettare per una nuova economia tessile circolare

L’industria tessile è la seconda fonte di inquinamento del Pianeta: risorse idriche, energetiche e umane vengono sfruttate per la produzione massiva di capi d’abbigliamento che, dopo solo un utilizzo, vengono gettati e smaltiti scorrettamente senza possibilità di una seconda vita. È da queste considerazioni, abbinate agli obiettivi dell’Agenda 2030 – e, ancora più in là, dell’Agenda 2050 – che si sviluppa il progetto “inverso”. Questo, nel tentativo di far fronte a tecnologie di riciclo ancora arretrate e con possibilità di sviluppo nei successivi due anni, vuole dare una seconda vita a tutti gli scarti di tessuto derivanti dall’industria di tappezzeria forlivese. Un territorio che acquista principalmente dalla Toscana, dal Veneto e dalla Lombardia, regioni italiane che durante la loro attività conciaria producono 1,46 Kg di scarti per ogni metro quadrato di pelli prodotte. "inverso" è un progetto alla cui base poggiamo virtuosi principi legati all’economia circolare, sviluppati tramite una progettazione attenta e un colloquio consapevole con la maggior parte degli attori coinvolti nel ciclo di vita del prodotto. Il mio progetto vuole inserirsi nell’ambito “slow fashion” nel tentativo di supportare una futura economia tessile circolare senza, però, porre in secondo piano l’esigenza prima della moda per ognuno di noi: esprimere se stessi.

Thermodynamic Study Of The Micellization Of Zwitterionic Surfactants And Their Interaction With Polymers In Water By Isothermal Titration Calorimetry.

The micellization of a homologous series of zwitterionic surfactants, a group of sulfobetaines, was studied using isothermal titration calorimetry (ITC) in the temperature range from 15 to 65 °C. The increase in both temperature and the alkyl chain length leads to more negative values of ΔGmic(0) , favoring the micellization. The entropic term (ΔSmic(0)) is predominant at lower temperatures, and above ca. 55-65 °C, the enthalpic term (ΔHmic(0)) becomes prevalent, figuring a jointly driven process as the temperature increases. The interaction of these sulfobetaines with different polymers was also studied by ITC. Among the polymers studied, only two induced the formation of micellar aggregates at lower surfactant concentration: poly(acrylic acid), PAA, probably due to the formation of hydrogen bonds between the carboxylic group of the polymer and the sulfonate group of the surfactant, and poly(sodium 4-styrenesulfonate), PSS, probably due to the incorporation of the hydrophobic styrene group into the micelles. The prevalence of the hydrophobic and not the electrostatic contributions to the interaction between sulfobetaine and PSS was confirmed by an increased interaction enthalpy in the presence of electrolytes (NaCl) and by the observation of a significant temperature dependence, the latter consistent with the proposed removal of hydrophobic groups from water.

An algorithm for computerized automatic tuning of power system stabilizers

The main objective of this paper is to relieve the power system engineers from the burden of the complex and time-consuming process of power system stabilizer (PSS) tuning. To achieve this goal, the paper proposes an automatic process for computerized tuning of PSSs, which is based on an iterative process that uses a linear matrix inequality (LMI) solver to find the PSS parameters. It is shown in the paper that PSS tuning can be written as a search problem over a non-convex feasible set. The proposed algorithm solves this feasibility problem using an iterative LMI approach and a suitable initial condition, corresponding to a PSS designed for nominal operating conditions only (which is a quite simple task, since the required phase compensation is uniquely defined). Some knowledge about the PSS tuning is also incorporated in the algorithm through the specification of bounds defining the allowable PSS parameters. The application of the proposed algorithm to a benchmark test system and the nonlinear simulation of the resulting closed-loop models demonstrate the efficiency of this algorithm. (C) 2009 Elsevier Ltd. All rights reserved.