3,823 research outputs found

    Efficient and Accurate hybrid GO-Spectral Algorithm to Design Conformal Serrated-Edge Reflectors Operating as Collimators in Millimeter Wave Compact Ranges

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    This paper presents a hybrid analysis algorithm, which is used at Radiation Group (UPM) to carry out the design of a conformal serrated-edge reflector for the mm-Wave compact range UPM facility. Main features of this algorithm involve its capability of handling conformal serrated rim parabolic reflectors, accuracy and computational efficiency

    Antenna Measurement System at 300 GHz for the Terasense Project

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    The aim of this paper is to introduce the design techniques used to develop the antenna measurement system for the Terasense Project. This project, funded by the Spanish Government, involves millimetre-wave systems design. One of these systems is an antenna measurement facility. The antenna measurement system operates in a banded range of frequency. The lower frequencies deal between 75–110 GHz (WR10 operation range) and the upper frequencies are set between 220–325 GHz (WR03). Among the different possible configurations, the reflector-based compact range is chosen. The quiet zone is generated by a serrated-edge reflector, fed by a low gain horn. In this paper we will focus on the reflector design. A serrations study is carried out and quiet zone acquisition results are obtained

    FROM WORLD 3 TO THE SOCIAL ASSESSMENT OF TECHNOLOGY

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    The monodirectional model of development of technology, from science to markai, reduces the role of society regarding technology to a passive element. The society is in practed by technology. The impacts could be good or not. We can identify and analyse (in advance) these impacts through the Technology Assessment methodology. Thus Technology Assessment is the same that Impacts Technology Assessment. However, we could interpet the development of technology according to multidirectional models (for example, evolutionary multidirectional models). In these models the society could play an active role. Society is not only the impacted target for technological development. Society is also the factor shaping technology. The second interpretation of technological development makes possible to propose and perform a methodology of Technology Assessment where relevant social groups (involved in or affected by the technology at issue) must be identified and their social behaviour has to be analyzed in situations of conflict (between groups) in order to detect the different technological options and their potential different impacts. It is the so-called Social (Strategic or Constructive) Technology Assessment

    Novel Method to Improve the Signal to Noise Ratio in the Far-field Results Obtained from Planar Near Field Measurements.

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    A method to reduce the noise power in far-field pattern without modifying the desired signal is proposed. Therefore, an important signal-to-noise ratio improvement may be achieved. The method is used when the antenna measurement is performed in planar nearfield, where the recorded data are assumed to be corrupted with white Gaussian and space-stationary noise, because of the receiver additive noise. Back-propagating the measured field from the scan plane to the antenna under test (AUT) plane, the noise remains white Gaussian and space-stationary, whereas the desired field is theoretically concentrated in the aperture antenna. Thanks to this fact, a spatial filtering may be applied, cancelling the field which is located out of the AUT dimensions and which is only composed by noise. Next, a planar field to far-field transformation is carried out, achieving a great improvement compared to the pattern obtained directly from the measurement. To verify the effectiveness of the method, two examples will be presented using both simulated and measured near-field data

    Trapped in gender : understanding the concept of gender and its use in law

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    What is gender? What is the meaning of gender in law? At first sight, these questions seem easy to answer, but the analysis and use of the concept of gender gives a very different picture. The concept of gender has credit in the fight for equality but, is it still useful to fight sex discrimination? This work tries to answer these questions exploring the concept of gender and its development within feminism. There are two main points of analyses, the construction of the concept tied to the notion of sex difference entrenching sex and gender in an indissoluble relation and, the development of the concept of gender within feminism. The concept of gender develops to become many things: the synonym of women, sex, social sex or even socio-cultural oppression. With regard to women, gender is a paradox: they have become neutral and equal subjects even if still keeping certain aspects of their womanhood. The concept of gender has also travelled into law incorporating the term, with its ambiguities in legislation. National and international laws have imported the same feminist ambiguities and the compulsory binary of sexual difference with the use term gender. The assumptions about sex and gender materialize in the reading of bodies legitimized by law. The relation between sex and gender is ruled by a gendered reading of the body. The restricted sexed depiction of the bodies interplay with the concept of gender producing inclusions and exclusions and ruling the bestowing of rights and responsibilities. The interplay of sex and gender with the feminist and the legal discourse continue to produce exclusions and hinders the possibilities of Queering the subject in society and in law. In relation to the subject, the concept of gender reifies the binary of sex and gender roles constraining further developments in the achievement of equality. The language of gender is exhausted thus the need of moving forward and look at new concepts that might depict the actual world

    Codimension one Ricci soliton subgroups of nilpotent Iwasawa groups

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    Any expanding homogeneous Ricci soliton (in particular any homogeneous Einstein manifold of negative scalar curvature) can be obtained, up to isometry, from a Lie subgroup of a nilpotent Iwasawa group NN whose induced metric is a Ricci soliton. By nilpotent Iwasawa group we mean the nilpotent Lie group NN of the Iwasawa decomposition associated with a symmetric space of non-compact type. Motivated by this fact, in this paper we classify codimension one Lie subgroups of any nilpotent Iwasawa group NN whose induced metric is a Ricci soliton

    Aspetti cinetici delle fermentazioni coinvolte nella produzione del Pane Toscano a lievitazione naturale.

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    La panificazione ha radici molto antiche: la forma di pane più antica rinvenuta in Europa (Twann, Svizzera) risale al 3530 a.C., ma sono stati gli Egiziani i primi a far lievitare l’impasto utilizzando la lievitazione naturale, ancora oggi utilizzata nella lavorazione di prodotti tipici tradizionali come il Pandoro ed il Panettone, ma anche del pane toscano a lievitazione naturale, un pane bianco, caratterizzato dall’assenza di sale, ottenuto utilizzando come materie prime farina di grano tenero, acqua e lievito naturale. L’impiego del lievito naturale ha riflessi positivi sulla conservabilità, sulla digeribilità, ma anche sulle caratteristiche organolettiche del pane finito, che si manifestano con un sapore ed un aroma peculiari, dovuti alla formazione di sostanze volatili aromatiche, che si formano durante la lievitazione e quindi la cottura. Poiché il conferimento del marchio DOP prevede che siano chiaramente ed univocamente individuate le caratteristiche che legano il prodotto finito al territorio di riferimento (Regione Toscana), non è possibile accettare degli intervalli di variabilità troppo elevati per i parametri che lo caratterizzano. Per assicurare la richiesta riproducibilità, occorre disporre di approfondite informazioni sulla composizione della microflora presente nell’impasto per evidenziare l’esistenza di eventuali correlazioni che la legano ai parametri chimico-fisici e organolettici del pane finito. A questo scopo dovranno essere individuate le relazioni che intercorrono tra le principali variabili tecnologiche (temperature, tempi, composizioni delle materie prime e degli intermedi di processo, pH, concentrazione di etanolo, concentrazione in acido lattico ed acetico, ecc.) e lo sviluppo delle diverse popolazioni microbiologiche, per produrre quegli algoritmi matematici in grado di descrivere l’andamento di questo sistema con i tempi, le temperature e le modalità operative impiegate. Presso tre forni toscani individuati dal Consorzio di promozione e tutela del pane toscano a lievitazione naturale, sono stati, quindi, raccolti campioni della madre acida e dell’impasto a diversi stadi di panificazione per sottoporli ad analisi microbiologica e chimico composizionale al fine di determinare l’evoluzione nel tempo dei principali metaboliti coinvolti nei processi fermentativi (ac. D,L-lattico, ac. acetico ed etanolo). A conferma di quanto riportato in letteratura, la quantità massima di metabolita accumulabile risulta più elevata nei campioni raccolti al centro dell’impasto rispetto a quelli provenienti dalla sua superficie. Infatti, come era facilmente prevedibile, la presenza dell’ossigeno tende ad inibire anche se in modo diversificato, i principali processi fermentativi portando ad una diversa distribuzione dei metaboliti nei campioni analizzati. Anche se le tecnologie e le madri acide utilizzate si diversificano in funzione del forno considerato, le costanti cinetiche connesse all’accumulo dei metaboliti con il tempo di lievitazione non sembrano diversificarsi sostanzialmente. Alla luce dei risultati ottenuti è possibile evidenziare come, adottando la stessa farina suggerita dal Consorzio, il tempo di lievitazione tenda ad annullare rendendole così meno evidenti, le pur notevoli differenze che intercorrono tra le madri a pasta acida utilizzate nei tre forni considerati. Sembrerebbe, quindi, possibile, adottando un'unica madre acida e una tecnologia di panificazione comune, ottenere nel tempo degli impasti sufficientemente simili, anche in forni collocati in zone differenti del territorio regionale e che utilizzano differenti acque di lavorazione
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