994 resultados para Real quadratic fields


Relevância:

20.00% 20.00%

Publicador:

Resumo:

RESUME: Une zone tectonique large et complexe, connue sous le nom de ligne des Centovalli, traverse le secteur des Alpes Centrales compris entre Domodossola et Locarno. Cette région, formée par le Val Vigezzo et la vallée des Centovalli, constitue la terminaison méridionale du dôme Lepontin et représente une portion de la zone des racines des nappes alpines. Elle fait partie d’une grande et complexe zone de cisaillement, en partie associée à des phénomènes hydrothermaux d’âge alpin (<20 Ma), qui comprend le système tectonique Insubrien et celui du Simplon. Le Val Vigezzo et les Centovalli constituent un vrai carrefour entre les principaux accidents tectoniques des Alpes ainsi qu'une zone de juxtaposition du socle Sudalpin avec la zone des racines de l’Austroalpin et du Pennique. Les phases de déformation et les structures géologiques qui peuvent être étudiées s'étalent sur une période comprise entre environ 35 Ma et l'actuel. L’étude détaillée de terrain a mis en évidence la présence de nombreuses roches et structures de déformation de type ductile et cassant tels que des mylonites, des cataclasites, des pseudotachylites, des kakirites, des failles minéralisées, des gouges de faille et des plis. Sur le terrain on a pu distinguer au moins quatre générations de plis liés aux différentes phases de déformation. Le nombre et la complexité de ces structures indiquent une histoire très compliquée, selon plusieurs étapes distinctes, parfois liées, voire même superposées. Une partie de ces structures de déformation affectent aussi les dépôts sédimentaires d’âge quaternaire, notamment des limons et des sables lacustres. Ces sédiments constituent les restes d'un bassin lacustre attribué à l'époque interglaciaire Riss/Würm (éemien, 67.000-120.000 ans) et ils affleurent dans la partie centrale de la zone étudiée, à l'Est de la plaine de Santa Maria Maggiore. Ces sédiments montrent en leur sein toute une série de structures de déformation tels que des plans de faille inverses, des structures conjuguées de raccourcissement et des véritables plis. Ces failles et ces plis représenteraient les évidences de surface d’une déformation probablement active en époque quaternaire. Une autre formation rocheuse a retenu tout notre attention; il s'agit d'un corps de brèches péridotitiques monogéniques qui affleure en discontinuité le long du versant méridional et le long du fond de la vallée Vigezzo sur environ 20 km. Ces brèches se posent indifféremment sur le socle (unités Finero, Orselina) ou sur les sédiments lacustres. Elles sont traversées par des plans de failles qui développent des véritables stries de faille et des gouges de faille; l’orientation de ces plans est la même que celle affectant les failles à gouges du socle. La genèse de cette brèche est liée à l'altération et au modelage glacier (rock-glaciers) d'une brèche tectonique originelle qui borde la partie externe du Corps de Finero. Les structures de déformation de cette brèche, pareillement à celles des sédiments lacustres, ont été considérées comme les évidences de surface d'une tectonique quaternaire active dans la région. La dernière phase de déformation cassante qui affecte cette région peut donc être considérée comme active en époque quaternaire. Une vue d’ensemble de la région étudiée nous permet de reconnaître à l’échelle régionale une zone de cisaillement complexe orientée E-W, parallèlement à l’axe de la vallée Centovalli-Val Vigezzo. Les données de terrain, indiquent que cette zone de cisaillement débute sous conditions ductiles et évolue en plusieurs étapes jusqu’à des conditions de failles cassantes de surface. La reconstruction de l'évolution géodynamique de la région a permis de définir trois étapes distinctes qui marquent le passage, de ce secteur de socle cristallin, de conditions P-T profondes à des conditions de surface. Dans ce contexte, on a reconnu trois phases principales de déformation à l’échelle régionale qui caractérisent ces trois étapes. La phase la plus ancienne est constituée par des mylonites en faciès amphibolite, associées à des mouvements de cisaillement dextre, qui sont ensuite remplacés par des mylonites en faciès schistes verts et des plis rétrovergentes liés au rétrocharriage des nappes alpines. Une deuxième étape est identifiée par le développement d’une phase hydrothermale liée à un système de failles extensives et décrochantes dextres à direction principale E-W, NE-SW et NW-SE. Leur caractérisation minéralogique a permis la mise en évidence des phases cristallines de néoformation liées à cet événement constituées par : K-feldspath (microcline), chlorites (Fe+Mg), épidotes, prehnite, zéolites (laumontite), sphène, calcite. Dans ce contexte, pour obtenir une meilleure caractérisation de cet événement hydrothermal on a utilisé des géothermomètres sur chlorites, sensible aussi à la pression et a la a(H2O), qui ont donné des valeurs descendantes comprises entre 450-200°C. Les derniers mouvements sont mis en évidence par le développement d’une série de plans majeurs de failles à gouge, qui forment une structure en sigmoïdes d’épaisseur kilométrique reconnaissable à l’échelle de la vallée et caractérisée par des mouvements transpressifs avec une composante décrochante dextre toujours importante. Cette phase de déformation forme un système conjugué de failles avec direction moyenne E-W qui coupent la zone des racines des nappes alpines, la zone du Canavese et le corps ultramafique de Finero. Ce système se déroule de manière subparallèle à l'axe de la vallée le long de plusieurs dizaines de kilomètres. Une analyse complète et détaillée des gouges de faille par XRD a montré que la fraction argileuse (<2 µm) de ces gouges contient une partie de néoformation très importante constituée par, des illites, des chlorites et des interstratifiés de type illite/smectite ou chlorite/smectite. Des datations avec méthode K-Ar sur ces illites ont donné des valeurs comprises entre 12 et 4 Ma qui représentent l'âge de cette dernière déformation cassante. L'application de la méthode de la cristallinité de l'illite (C.I.) a permis d'évaluer les conditions thermiques qui caractérisent le déroulement de cette dernière phase tectonique qui se produit sous conditions de température caractéristiques de l'anchizone et de la diagenèse. L'ensemble des structures de déformation qu'on vient de décrire s'insère parfaitement dans le contexte de convergence oblique entre la plaque adriatique et celle européenne qui à produit l'orogène alpin. On peut considérer les structures tectoniques du Val Vigezzo-Centovalli comme l'expression d'une zone majeure de cisaillement "Simplo-Insubrienne". L'empilement structural et les structures tectoniques affleurantes dans la région sont le résultat de l'interaction entre un régime tectonique transpressif et un régime transtensif. Ces deux champs de tension sont antagonistes entre eux mais sont reliés, de toute façon, à une seule phase décrochante dextre principale, due à une convergence oblique entre deux plaques. À l'échelle de l'évolution géodynamique on peut distinguer différentes étapes au cours desquelles les structures de ces deux régimes tectoniques interagissent en manière différente. En accord avec les données géophysiques et les reconstructions paléodynamiques prises dans la littérature on considère que la ligne Rhône-Simplon-Centovalli représente l'évidence de surface de la suture majeure profonde entre la plaque Adriatique et celle Européenne. Les vitesses de soulèvement qui ont été calculées dans cette étude pour cette région des Alpes donnent une valeur moyenne de 0.8 mm/a qui est tout à fait comparable avec les données proposées par la littérature sur cette zone. La zone Val Vigezzo-Centovalli peut être donc considérée comme un carrefour géologique où se croisent différentes phases tectoniques qui représentent les évidences de surface d'une suture profonde majeure entre deux plaques dans un contexte de collision continentale. ABSTRACT: A wide and complex tectonic zone known as Centovalli line, crosses the Central Alps sector between Domodossola and Locarno. This area, formed by the Vigezzo Valley and Centovalli valley, constitutes the southernmost termination of the Lepontin dome and represents a portion of the alpine nappes root zone. It belongs to a large and complex shear-zone, partly associated with hydrothermal phenomena of alpine age (<20 My), which includes the Insubric Line and the Simplon fault zone. Vigezzo Valley and Centovalli constitute a real crossroads between the mains alpines tectonics lines as well as a zone of juxtaposition of the Southalpine basement with the Austroalpin and Pennique root zone. The deformation phases and the geological structures that can be studied between approximately 35 My and the present. The detailed field study showed the presence of many brittle and ductile deformation structures and fault rocks such as mylonites, cataclasites, pseudotachylites, kakirites, mineralized faults, fault gouges and folds. In the field we could distinguish at least four folds generations related to the various deformation phases. The number and the complexity of these structures indicate a very complicated history, comprising several different stages, that sometimes are related and even superimposed. Part of these deformation structures affect also the sedimentary deposits of quaternary age, in particular the silts and sands lake deposit. These sediments constitute the remainders of a lake basin ascribed to the interglacial Riss/Würm (Eemien, 67.000-120.000 years) and outcroping in the central part of the studied area, in the Eastern part of Santa Maria Maggiore plain. These sediments show a whole series of deformation structures such as inverse fault planes, combined shortening structures and true folds. These faults and folds would represent the surface evidence of a probably active tectonic deformation in quaternary time. Another rock formation attracted all our attention. It is a body of monogenic peridotite breccia which outcrops in discontinuity along the southernmost slope and the bottom of the Vigezzo valley on approximately 20 km. This breccia lies indifferently on the basement (Finero and Orselina units) or on the lake sediments. They are crossed by fault planes which developed slikenside and fault gouges whose orientation is the same of the faults gouges in the alpine basement. This breccia results from the weathering and the surface modelling of an original tectonic breccia which borders the external part of Finero peridotite body. This breccia deformation structures, like those of the lake sediments, were regarded as the surface interaction of active quaternary tectonics in the area. So the last brittle deformation phases which affects this area seems to be actives in quaternary time. Theoverall picture of the studied area on a regional scale enables us to point out a complex shear-zone directed E-W, parallel to the axis of the Centovalli and Vigezzo Valley. The field analysis indicates that this shear-zone began under ductile conditions and evolved in several stages to brittle faulting under surface conditions. The analysis of the geodynamic evolution of the area allows to define three different stages which mark the transition of this alpine basement root zone, from deep P-T conditions to P-T surface conditions. In this context on regional scale three principal deformation phases, which characterize these three stages can be distinguished. The oldest phase consisted of the amphibolitie facies mylonites, associated to dextral strikeslip movements. They are then replaced by green-schists facies mylonites and backfolds related to the backthrusting of the alpines nappes. A second episode is caracterized by the development of an hydrothermal phase bound to an extensive fault and dextral strike-slip fault system, with E-W, NW-SE and SE-NW principal directionsThe principal neoformed mineral phases related to this event are: K-feldspar (microcline), chlorites (Fe+Mg), epidotes prehnite, zéolites (laumontite), sphene and calcite. In this context, to obtain a better characterization of this hydrothermal event, we have used an chlorite geothermometer, sensitive also to the pressure and has the a(H2O), which gave downward values ranging between 450-200°C. The last movements are caracterized by the development of important gouge fault plans, which form a sigmoid structure of kilometric thickness which is recognizable at the valley scale, and is characterized by transpressive movements always with a significant dextral strike-slip component. This deformation phase forms a combined faults system with an average E-W direction, which cuts trough the alpine root zone, the Canavese zone and the Finero ultramafic body. This fault system takes place subparallel to the axis of the valley over several tens of kilometers. A complete and detailed XRD analysis of the gouges fault showed that the clay fraction (<2µm) contains a very significant neo-formation of illite, chlorites and mixed layered clays such as illite/smectite or chlorite/smectite. The K-Ar datings of the illite fraction <2µm gave values ranging between 12 and 4 My and the illite fraction <0.2µm gave more recents values until to 2,4-0 My.This values represent the age of this last brittle deformation. The application of the illite crystallinity method (C.I.) allowed evaluating the thermal conditions which characterize this tectonic phase that occured under temperature conditions of the anchizone and diagenesis. The whole set of deformation structures which we just described, perfectly fit the context of oblique convergence between the Adriatic and the European plate that produced the alpine orogen. We can regard the Vigezzo valley and Centovalli tectonic structures as the expression of a major "Simplo-Insubric" shear-zone. Structural stacking and tectonic structures that outcrop in the studied area, are the result of the interaction between a transpressive and a transtensve tectonic phases. These two tension fields are antagonistic but they are also connected, in any event, with only one principal dextral strike-slip movement, caused by an oblique convergence between two plates. On the geodynamic evolution scale we can distinguish various stages during which these two tectonic structures fields interact in various ways. In agreement with the geophysical data and the paleodynamic recostructions taken in the literature we considers that the Rhone-Simplon-Centovalli line are the surface feature of the major collision between the Adriatique and the European plate at depth. The uplift speeds we calculated in this study for this Alpine area give an average value of 0.8 mm/a, which is in good agreement with the data suggested by the literature on this zone. TheVigezzo Valley and Centovalli zone can therefore be regarded as a geological crossroad where various tectonic phases are superimposed. They represent the evidences of a major and deeper suture between two plates in a continental collision context.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Abstract The main objective of this work is to show how the choice of the temporal dimension and of the spatial structure of the population influences an artificial evolutionary process. In the field of Artificial Evolution we can observe a common trend in synchronously evolv¬ing panmictic populations, i.e., populations in which any individual can be recombined with any other individual. Already in the '90s, the works of Spiessens and Manderick, Sarma and De Jong, and Gorges-Schleuter have pointed out that, if a population is struc¬tured according to a mono- or bi-dimensional regular lattice, the evolutionary process shows a different dynamic with respect to the panmictic case. In particular, Sarma and De Jong have studied the selection pressure (i.e., the diffusion of a best individual when the only selection operator is active) induced by a regular bi-dimensional structure of the population, proposing a logistic modeling of the selection pressure curves. This model supposes that the diffusion of a best individual in a population follows an exponential law. We show that such a model is inadequate to describe the process, since the growth speed must be quadratic or sub-quadratic in the case of a bi-dimensional regular lattice. New linear and sub-quadratic models are proposed for modeling the selection pressure curves in, respectively, mono- and bi-dimensional regu¬lar structures. These models are extended to describe the process when asynchronous evolutions are employed. Different dynamics of the populations imply different search strategies of the resulting algorithm, when the evolutionary process is used to solve optimisation problems. A benchmark of both discrete and continuous test problems is used to study the search characteristics of the different topologies and updates of the populations. In the last decade, the pioneering studies of Watts and Strogatz have shown that most real networks, both in the biological and sociological worlds as well as in man-made structures, have mathematical properties that set them apart from regular and random structures. In particular, they introduced the concepts of small-world graphs, and they showed that this new family of structures has interesting computing capabilities. Populations structured according to these new topologies are proposed, and their evolutionary dynamics are studied and modeled. We also propose asynchronous evolutions for these structures, and the resulting evolutionary behaviors are investigated. Many man-made networks have grown, and are still growing incrementally, and explanations have been proposed for their actual shape, such as Albert and Barabasi's preferential attachment growth rule. However, many actual networks seem to have undergone some kind of Darwinian variation and selection. Thus, how these networks might have come to be selected is an interesting yet unanswered question. In the last part of this work, we show how a simple evolutionary algorithm can enable the emrgence o these kinds of structures for two prototypical problems of the automata networks world, the majority classification and the synchronisation problems. Synopsis L'objectif principal de ce travail est de montrer l'influence du choix de la dimension temporelle et de la structure spatiale d'une population sur un processus évolutionnaire artificiel. Dans le domaine de l'Evolution Artificielle on peut observer une tendence à évoluer d'une façon synchrone des populations panmictiques, où chaque individu peut être récombiné avec tout autre individu dans la population. Déjà dans les année '90, Spiessens et Manderick, Sarma et De Jong, et Gorges-Schleuter ont observé que, si une population possède une structure régulière mono- ou bi-dimensionnelle, le processus évolutionnaire montre une dynamique différente de celle d'une population panmictique. En particulier, Sarma et De Jong ont étudié la pression de sélection (c-à-d la diffusion d'un individu optimal quand seul l'opérateur de sélection est actif) induite par une structure régulière bi-dimensionnelle de la population, proposant une modélisation logistique des courbes de pression de sélection. Ce modèle suppose que la diffusion d'un individu optimal suit une loi exponentielle. On montre que ce modèle est inadéquat pour décrire ce phénomène, étant donné que la vitesse de croissance doit obéir à une loi quadratique ou sous-quadratique dans le cas d'une structure régulière bi-dimensionnelle. De nouveaux modèles linéaires et sous-quadratique sont proposés pour des structures mono- et bi-dimensionnelles. Ces modèles sont étendus pour décrire des processus évolutionnaires asynchrones. Différentes dynamiques de la population impliquent strategies différentes de recherche de l'algorithme résultant lorsque le processus évolutionnaire est utilisé pour résoudre des problèmes d'optimisation. Un ensemble de problèmes discrets et continus est utilisé pour étudier les charactéristiques de recherche des différentes topologies et mises à jour des populations. Ces dernières années, les études de Watts et Strogatz ont montré que beaucoup de réseaux, aussi bien dans les mondes biologiques et sociologiques que dans les structures produites par l'homme, ont des propriétés mathématiques qui les séparent à la fois des structures régulières et des structures aléatoires. En particulier, ils ont introduit la notion de graphe sm,all-world et ont montré que cette nouvelle famille de structures possède des intéressantes propriétés dynamiques. Des populations ayant ces nouvelles topologies sont proposés, et leurs dynamiques évolutionnaires sont étudiées et modélisées. Pour des populations ayant ces structures, des méthodes d'évolution asynchrone sont proposées, et la dynamique résultante est étudiée. Beaucoup de réseaux produits par l'homme se sont formés d'une façon incrémentale, et des explications pour leur forme actuelle ont été proposées, comme le preferential attachment de Albert et Barabàsi. Toutefois, beaucoup de réseaux existants doivent être le produit d'un processus de variation et sélection darwiniennes. Ainsi, la façon dont ces structures ont pu être sélectionnées est une question intéressante restée sans réponse. Dans la dernière partie de ce travail, on montre comment un simple processus évolutif artificiel permet à ce type de topologies d'émerger dans le cas de deux problèmes prototypiques des réseaux d'automates, les tâches de densité et de synchronisation.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Adaptació de l'algorisme de Kumar per resoldre sistemes d'equacions amb matrius de Toeplitz sobre els reals a cossos finits en un temps 0 (n log n).

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The objective of the dissertation is to increase understanding and knowledge in the field where group decision support system (GDSS) and technology selection research overlap in the strategic sense. The purpose is to develop pragmatic, unique and competent management practices and processes for strategic technology assessment and selection from the whole company's point of view. The combination of the GDSS and technology selection is approached from the points of view of the core competence concept, the lead user -method, and different technology types. In this research the aim is to find out how the GDSS contributes to the technology selection process, what aspects should be considered when selecting technologies to be developed or acquired, and what advantages and restrictions the GDSS has in the selection processes. These research objectives are discussed on the basis of experiences and findings in real life selection meetings. The research has been mainly carried outwith constructive, case study research methods. The study contributes novel ideas to the present knowledge and prior literature on the GDSS and technology selection arena. Academic and pragmatic research has been conducted in four areas: 1) the potential benefits of the group support system with the lead user -method,where the need assessment process is positioned as information gathering for the selection of wireless technology development projects; 2) integrated technology selection and core competencies management processes both in theory and in practice; 3) potential benefits of the group decision support system in the technology selection processes of different technology types; and 4) linkages between technology selection and R&D project selection in innovative product development networks. New type of knowledge and understanding has been created on the practical utilization of the GDSS in technology selection decisions. The study demonstrates that technology selection requires close cooperation between differentdepartments, functions, and strategic business units in order to gather the best knowledge for the decision making. The GDSS is proved to be an effective way to promote communication and co-operation between the selectors. The constructs developed in this study have been tested in many industry fields, for example in information and communication, forest, telecommunication, metal, software, and miscellaneous industries, as well as in non-profit organizations. The pragmatic results in these organizations are some of the most relevant proofs that confirm the scientific contribution of the study, according to the principles of the constructive research approach.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

A Catalunya, en els darrers anys, han anat proliferant una sèrie de «professionals» que realitzen, amb més o menys adequació a la definició teòrica, la funció de mediadors inter-culturals. Primerament, es tractava de gitanos, però darrerament, fruit de l’increment de la presència d’infants d’origen immigrant a les escoles catalanes, s’ha vist créixer el nombre i el protagonisme dels estrangers pel reconeixement que se’ls ha donat des de l’Administració i des de les institucions. Els mediadors han intentat intervenir en qüestions com ara la participació dels pares d’origen minoritari, l’adaptació del currículum a la diversitat cultural, la negociació de conflictes culturals, la desescolarització, l’absentisme i l’abandonament escolar dels alumnes durant el període d’escolarització obligatòria, la traducció lingüística i la interpretació sociocultural, etc. Concretament, la nostra recerca ha consistit en vint-i-set entrevistes en profunditat a mediadors interculturals de tot Catalunya.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The optimization of most pesticide and fertilizer applications is based on overall grove conditions. In this work we measurements. Recently, Wei [9, 10] used a terrestrial propose a measurement system based on a ground laser scanner to LIDAR to measure tree height, width and volume developing estimate the volume of the trees and then extrapolate their foliage a set of experiments to evaluate the repeatability and surface in real-time. Tests with pear trees demonstrated that the accuracy of the measurements, obtaining a coefficient of relation between the volume and the foliage can be interpreted as variation of 5.4% and a relative error of 4.4% in the linear with a coefficient of correlation (R) of 0.81 and the foliar estimation of the volume but without real-time capabilities. surface can be estimated with an average error less than 5 %.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

This paper is devoted to the study of the volcanoes of l-isogenies of elliptic curves over a finite field, focusing on their height as well as on the location of curves across its different levels. The core of the paper lies on the relationship between the l-Sylow subgroup of an elliptic curve and the level of the volcano where it is placed. The particular case l = 3 is studied in detail, giving an algorithm to determine the volcano of 3-isogenies of a given elliptic curve. Experimental results are also provided.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Revealing the parties, the processes and the institutions and, consequently, both the diversity and contingency of the real estate markets, the existing increasing literature emphasises the contemporary numerous links and interdependencies between real estate, land value, planning and town planning policy and even the financial system. This paper is an attempt to understand all the real estate markets, from the most peripheral ones, where the urban rent is the lowest, to the most dense city centres. To gain a better understanding of the real estate market, a process of firstly deconstruction and then reconstruction is used. The process of deconstruction involves identifying various market trends according to property type (principally residential buildings), players and institutions, territorial situations and temporalities based on research conducted in Switzerland. We then developed a meta-synthesis inspired by Fernand Braudel whose works put as much emphasis on day-to-day economic activity as on long-term activity, and on local as well as global issues.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

This work proposes the development of an embedded real-time fruit detection system for future automatic fruit harvesting. The proposed embedded system is based on an ARM Cortex-M4 (STM32F407VGT6) processor and an Omnivision OV7670 color camera. The future goal of this embedded vision system will be to control a robotized arm to automatically select and pick some fruit directly from the tree. The complete embedded system has been designed to be placed directly in the gripper tool of the future robotized harvesting arm. The embedded system will be able to perform real-time fruit detection and tracking by using a three-dimensional look-up-table (LUT) defined in the RGB color space and optimized for fruit picking. Additionally, two different methodologies for creating optimized 3D LUTs based on existing linear color models and fruit histograms were implemented in this work and compared for the case of red peaches. The resulting system is able to acquire general and zoomed orchard images and to update the relative tracking information of a red peach in the tree ten times per second.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

O objetivo deste trabalho foi avaliar a produção da cultivar de morangueiro Camino Real, recentemente introduzida da Califórnia, comparando-a com a das cultivares Aromas e Camarosa, nas condições climáticas do Rio Grande do Sul. O experimento foi realizado em Pelotas, utilizando-se do sistema de produção sob túnel e mudas importadas do Chile. A irrigação foi feita por gotejamento, e a adubação, fornecida via água de irrigação. Em maio de 2006, foi feito o transplantio das mudas no espaçamento de 35 cm entre linhas e entre plantas. Semanalmente, de agosto a dezembro, foram analisadas as variáveis massa fresca e número médio de frutos produzidos. O delineamento experimental foi de blocos casualizados com parcelas subdivididas no tempo, com quatro repetições. As unidades experimentais foram constituídas por 21 plantas. Verificou-se que a produção da cultivar Camino Real (1.121,2 g de frutos comerciais por planta por ano) é semelhante à da 'Aromas' (1.043,3 g) e à da 'Camarosa' (1.038,3 g). Os frutos da 'Camino Real' são maiores e de maior massa (24,6 g) em relação aos da 'Camarosa' (19,5 g) e da 'Aromas' (17,9 g), sendo, no entanto, produzidos em menor número. A máxima massa fresca obtida da cv. Camino Real é de 30,7 g, na 12ª semana de colheita.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The need for high performance, high precision, and energy saving in rotating machinery demands an alternative solution to traditional bearings. Because of the contactless operation principle, the rotating machines employing active magnetic bearings (AMBs) provide many advantages over the traditional ones. The advantages such as contamination-free operation, low maintenance costs, high rotational speeds, low parasitic losses, programmable stiffness and damping, and vibration insulation come at expense of high cost, and complex technical solution. All these properties make the use of AMBs appropriate primarily for specific and highly demanding applications. High performance and high precision control requires model-based control methods and accurate models of the flexible rotor. In turn, complex models lead to high-order controllers and feature considerable computational burden. Fortunately, in the last few years the advancements in signal processing devices provide new perspective on the real-time control of AMBs. The design and the real-time digital implementation of the high-order LQ controllers, which focus on fast execution times, are the subjects of this work. In particular, the control design and implementation in the field programmable gate array (FPGA) circuits are investigated. The optimal design is guided by the physical constraints of the system for selecting the optimal weighting matrices. The plant model is complemented by augmenting appropriate disturbance models. The compensation of the force-field nonlinearities is proposed for decreasing the uncertainty of the actuator. A disturbance-observer-based unbalance compensation for canceling the magnetic force vibrations or vibrations in the measured positions is presented. The theoretical studies are verified by the practical experiments utilizing a custom-built laboratory test rig. The test rig uses a prototyping control platform developed in the scope of this work. To sum up, the work makes a step in the direction of an embedded single-chip FPGA-based controller of AMBs.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Colorectal cancer (CRC) is the second leading cause of cancer-related death in developed countries. Early detection of CRC leads to decreased CRC mortality. A blood-based CRC screening test is highly desirable due to limited invasiveness and high acceptance rate among patients compared to currently used fecal occult blood testing and colonoscopy. Here we describe the discovery and validation of a 29-gene panel in peripheral blood mononuclear cells (PBMC) for the detection of CRC and adenomatous polyps (AP). Blood samples were prospectively collected from a multicenter, case-control clinical study. First, we profiled 93 samples with 667 candidate and 3 reference genes by high throughput real-time PCR (OpenArray system). After analysis, 160 genes were retained and tested again on 51 additional samples. Low expressed and unstable genes were discarded resulting in a final dataset of 144 samples profiled with 140 genes. To define which genes, alone or in combinations had the highest potential to discriminate AP and/or CRC from controls, data were analyzed by a combination of univariate and multivariate methods. A list of 29 potentially discriminant genes was compiled and evaluated for its predictive accuracy by penalized logistic regression and bootstrap. This method discriminated AP >1cm and CRC from controls with a sensitivity of 59% and 75%, respectively, with 91% specificity. The behavior of the 29-gene panel was validated with a LightCycler 480 real-time PCR platform, commonly adopted by clinical laboratories. In this work we identified a 29-gene panel expressed in PBMC that can be used for developing a novel minimally-invasive test for accurate detection of AP and CRC using a standard real-time PCR platform.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Reproductive traits play a key role in pig production in order to reduce costs and increase economic returns. Among others, gene expression analyses represent a useful approach to study genetic mechanisms underlying reproductive traits in pigs. The application of reverse-transcription quantitative PCR requires the selection of appropriate reference genes, whose expression levels should not be affected by the experimental conditions, especially when comparing gene expression across different physiological stages.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The complexing capacity of synthetic (0.011 M tartrate in 13.5% ethanol) and real wine (Raimat Abadia) in titrations with added total Zn concentrations up to 0.03 M has been determined following the free Zn concentrations with AGNES (absence of gradients and Nernstian equilibrium stripping) technique. A correction to find the preconcentration factor or gain (Y1) really applied at each one of the ionic strengths reached due to Zn additions along the titration has been applied. The standard implementation of AGNES to real wine led to the observation of two anomalous behaviors: (a) an increasingly negative current in the deposition stage (labeled as “HER” effect) and (b) a minimum in the currents of the stripping stage plot (labeled as the “dip” effect). A practical strategy to apply AGNES avoiding the dip effect has been developed to quantify properly free Zn concentrations. The van den Berg–Ružic–Lee linearization method (assuming the existence of just 1:1 complexes) has been adapted to consider the dilution effect and the ionic strength changes. Aggregated stability constants and total ligand concentrations have been calculated from synthetic and wine titration data. The found complexing capacity in the studied wine (cT,L = 0.0179 ± 0.0007 M) indicates the contribution of ligands other than tartrate (which is confirmed to be the main one).