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Task Complexity (‘Here-and- Now’ Dimension) and Written Performance across Proficiency LevelsKalamakis, Sara Zoi January 2019 (has links)
Research on task-based language teaching (TBLT) offers a large body of evidence suggesting that cognitive task complexity influences learners’ language production and development. Studies that investigate task complexity, however, provide contradictory results on the way different linguistic aspects of performance are affected by the manipulation of cognitive task complexity. The empirical study presented in this degree project aimed to investigate the effect of task complexity on the accuracy, complexity and fluency in learners ́ written performance. An additional goal of the study was to examine whether proficiency level would mediate the effects of cognitive task complexity. In order to explain the influence of cognitive task complexity on linguistic performance two theoretical models are used and discussed, namely Skehan’s Limited Attention Capacity Hypothesis (Skehan 2015) and Robinson’s Cognition Hypothesis (Robinson 2001, 2011, 2015). In order to answer the research questions guiding the study, 71 Swedish high school students of Spanish performed a simple or a more cognitively complex version of a written task. Results showed that increasing task complexity had a positive effect on the fluency, accuracy, and complexity of the participants ́ written performance, and that these effects were greater among the high proficiency participants’ productions. These results offer valuable implications for syllabus and task designers, language teachers and examiners, as well as second and foreign language researchers.
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Skriftlig produktion hos vuxna inlärare på avancerade språkfärdighetsnivåer : En CAF-undersökning om språkutveckling av svenska som andraspråk i akademiskt sammanhangZAVALA MIRANDA, CRISTINA January 2023 (has links)
Forskning inom andraspråksinlärning har visat att inlärares grammatiska kompetens kan beskrivas utifrån CAF, ett ramverk som innefattar tre dimensioner av performans: komplexitet (eng. complexity), korrekthet (eng. accuracy) och flyt (eng. fluency). Dessa tre dimensioner undersöks utifrån mått som mäter olika språkliga strukturer och fenomen. Sådana studier har genomförts internationellt men det saknas liknande forskning i en svensk kontext. Syftet med föreliggande undersökning är att analysera den skriftliga performansen hos vuxna inlärare av svenska som andraspråk för att kunna avgöra det bästa tillvägagångssättet för en undersökning av skriftlig språkutveckling hos avancerade inlärare. Närmare bestämt utreds hur de olika måtten förhåller sig till varandra, hur de skiljer sig åt beroende på inlärarens språkfärdighetsnivå och hur de utvecklas under ca en termins språkstudier. De 44 undersökta texterna är skrivna av 22 inlärare indelade i två språkfärdighetsnivåer (motsvarande B2 respektive C1 på GERS-skalan) inom ramen för deras deltagande i intensiv språkundervisning av akademisk svenska. I undersökningen analyserades texterna utifrån mått på produktivitet, korrekthet och komplexitet. Resultaten, som delvis stämmer överens med tidigare forskning, visar att komplexitet, både lexikal och syntaktisk, utvecklas signifikant över tid samt att produktivitet och syntaktisk komplexitet visar på signifikanta skillnader mellan de två språkfärdighetsnivåerna. Inga signifikanta korrelationer fanns mellan produktivitet, korrekthet och komplexitet men signifikanta korrelationer sågs mellan olika komplexitetsmått och mellan olika korrekthetsmått. Utifrån diskussionen om undersökningens resultat presenteras en rad överväganden som bör göras vid framtida studier, vilket lägger grunden för framtida forskning utifrån CAF-ramverket inom svenska som andraspråk.
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Kvalita ve školstvíUldrychová, Hana January 2007 (has links)
Práce vymezuje pojetí kvality ve školství, její vývoj a hodnocení. Dává přehled, jaké modely a nástroje se dají využívat pro řízení kvality ve vzdělávací instituci - jedná se o normu ISO 9001:2000, ISO/IWA 2:2003, filosofii TQM, Model excelence EFQM a model CAF. Dále zjišťuje pomocí dotazníkového šetření, jak základní a střední školy v ČR vnímají kvalitu a zda znají nebo využívají některé přístupy pro řízení kvality.
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Μέτρηση απόδοσης επιχειρήσεων / Business performance measurementΜυγδάκος, Γρηγόριος 03 July 2009 (has links)
Η παρούσα εργασία αποτελεί μία βιβλιογραφική διερεύνηση των κυριότερων Μεθόδων Μέτρησης Απόδοσης των επιχειρήσεων. Έγινε μια προσπάθεια να συγκεντρωθούν οι σημαντικότερες μέθοδοι, να αναλυθούν και τελικά να συγκριθούν για την επιλογή της μέχρι τώρα καταλληλότερης μεθόδου.
Η αρθρογραφία πάνω στη Μέτρηση της Απόδοσης των Επιχειρήσεων, είναι πλούσια και συνεχώς αυξανόμενη. Αυτό οφείλεται στην ανάγκη των επιχειρήσεων να πρωταγωνιστήσουν σε ένα συνεχώς μεταβαλλόμενο και πλήρως ανταγωνιστικό επιχειρησιακό περιβάλλον, με μεγάλες αλλαγές να διαδραματίζονται στους κοινωνικο-τεχνικούς παράγοντες αλλά και στα χαρακτηριστικά λειτουργίας των επιχειρήσεων. Ενδεικτικά αναφέρουμε: την παγκοσμιοποίηση των αγορών, την απελευθέρωση των αγορών, την «Οικονομία των Υπηρεσιών», τις ταχύτατες εξελίξεις στην πληροφορική και τις επικοινωνίες, την αύξηση της επιρροής και της εστίασης στις ανάγκες των πελατών από πλευράς επιχείρησης, την διαφοροποίηση των αναγκών και την αύξηση των προσδοκιών εξυπηρέτησης των πελατών κλπ. Όλα αυτά συνθέτουν ένα νέο κοινωνικό, οικονομικό, τεχνολογικό, ηθικό και πολιτικό πλαίσιο λειτουργίας της κοινωνίας, της οικονομίας και των επιχειρήσεων γενικότερα.
Κυριότεροι ερευνητές που ασχολήθηκαν με το θέμα της Μέτρησης της Απόδοσης των επιχειρήσεων είναι οι: Kaplan R., Norton D., Neeley A., Gregory M., Platts k., Eccles R., με τις εργασίες “The balance Scorecard – Translating Strategy into Action” Kaplan and Norton , “Performance Measurement – Why, What and How” του Neeley και “The performance Prism perspective” των Neeley και Adams , να είναι οι κυριότερες και με τον μεγαλύτερο αριθμό αναφορών(citations) σε αυτές μέχρι σήμερα.
Η μέθοδος που ξεχωρίζει τόσο σε πλήθος βιβλιογραφίας όσο και σε πλήθος αναφορών είναι η Balance Scorecard, καλύπτοντας τα ¾ όλης της υπάρχουσας βιβλιογραφίας, με το υπόλοιπο ¼ να μοιράζεται στις υπόλοιπες μεθόδους. Δεν είναι τυχαίο επομένως η μεγάλη χρήση της μεθόδου αυτής από παγκόσμιες επιχειρήσεις που κατατάσσονται στο τοπ 10 των επιχειρηματικών περιοδικών Fortune και Business Week. Το γεγονός αυτό έρχεται να επικυρώσει και η συγκεκριμένη εργασία κατατάσσοντας την μέθοδο Balance Scorecard ως πληρέστερη - πιο ολοκληρωμένη έναντι των υπολοίπων μεθόδων.
Η παρούσα εργασία απαρτίζεται από εννέα κεφάλαια.
Στο 1ο Κεφάλαιο περιγράφεται η έννοια της αποδοτικότητας, η ανάγκη μέτρησης της αποδοτικότητας που έχει ανακύψει στο σύγχρονο περιβάλλον των επιχειρήσεων και ένα σύνολο δεικτών που χρησιμοποιούνται στη διαδικασία μέτρησής της.
Στο 2ο Κεφάλαιο περιγράφεται η έννοια της μέτρησης τη απόδοσης, δίνεται μία περιληπτική περιγραφή των μεθόδων που υπάρχουν στην βιβλιογραφία και των συνθηκών που πρέπει να ικανοποιούνται για τη σωστή εφαρμογή των μεθόδων μέτρησης αποδοτικότητας.
Στο κεφάλαιο 3 περιγράφεται: η μέθοδος Balance Scorecard, οι μέθοδοι προσδιορισμού των δεικτών - κλειδιά απόδοσης της επιχείρησης (SWOT, QFD, PVA), η μέθοδος της Αναλυτικής Ιεράρχησης για την επιλογή των βασικών δεικτών-κλειδιά απόδοσης και τον καθορισμό των στατιστικών τους βαρών, οι προϋποθέσεις για τον επιτυχή προσδιορισμό και επιλογή των δεικτών κλειδιά στον πινάκα ισορροπημένης στοχοθεσίας, η προσαρμογή του πινάκα ισορροπημένης στοχοθεσίας στις μεταβαλλόμενες συνθήκες του περιβάλλοντος και ο διαχρονικός διαχωρισμός αίτιου και αποτελέσματος.
Στο 4ο Κεφάλαιο γίνεται περιγραφή του Κοινού πλαισίου Αξιολόγησης
Στο 5ο Κεφάλαιο γίνεται περιγραφή της μεθόδου Διοίκησης Ολικής Ποιότητας, αναφέρονται οι κύριες αρχές εφαρμογής της μεθόδου, οι στόχοι ενός συστήματος αυτής της μεθόδου, οι κρίσιμοι παράγοντες επιτυχής εφαρμογής της και εργαλεία και μεθοδολογίες που χρησιμοποιούνται για την εφαρμογή της.
Στο 6ο Κεφάλαιο περιγράφεται το Μοντέλο επιχειρηματικής Αριστείας (EFQM), τα επίπεδά του και τα θετικά αποτελέσματα από την εφαρμογή της μεθόδου στην επιχείρηση.
Στο 7ο Κεφάλαιο περιγράφεται η μέθοδος της Συγκριτικής Αξιολόγησης, οι στόχοι τα οφέλη και οι παγίδες που κρύβει η εφαρμογή της, οι προϋποθέσεις εφαρμογής της μεθόδου, η διαδικασία εφαρμογής καθώς και μία σειρά εργαλείων απαραίτητα για την εφαρμογή της.
Στο 8ο Κεφάλαιο γίνεται αναφορά στις μεθοδολογίες SEM, ISO, στο Πλαίσιο των 7-S, στο Performance Prism και στο Activity based Business Modeling for Government. Αναλύονται τα κύρια σημεία της κάθε μεθοδολογίας τα κύρια σημεία εφαρμογής της κάθε μίας μεθόδου και τα πλεονεκτήματα εφαρμογής τους σε μία επιχείρηση.
Στο 9ο Κεφάλαιο γίνεται μία προσπάθεια να συγκριθούν οι κυριότερες μέθοδοι μέτρησης αποδοτικότητας, υιοθετείται ένα σύνολο 10 κριτηρίων, γίνεται μία σύνοψη των αποτελεσμάτων της σύγκρισης και προτείνεται από την εργασία ένα πλαίσιο μεθοδολογίας. / The present study is a bibliographic investigation concerning the main Performance Measurement Methods. Important methods are assembled, analyzed and compared in an attempt to find the best one applied to the research study subject.
The work is composed from nine chapters. The 1st chapter describes the significance of an enterprise performance, the need for its measurement that emerged in the frame of the modern environment of the enterprises and the total number of indices used in the process of measurement.
The 2nd one describes the significance of the output measurement by summarizing the relevant methods existing in bibliography, along with the conditions satisfied for a correct application of the methods referring to the efficiency measurement.
In chapter three, the various methods such as: Balance Scorecard, the methods of determining the indices – keys of enterprise output (SWOT, QFD, PVA), the method of Hierarchy Analysis for selecting the basic indicators of output, as well as, the determination of it statistical weights, the conditions for a successful determination, the choice of indicator keys in the table balanced target setting, the adaptation of table of balanced target setting in the altered conditions of environment and the diachronic segregation of cause and effect, are presented.
Chapter 4th presents the common frame of evaluation. In the 5th chapter the description of the Total Quality Management method is reported with references to the main application methods, the objectives of the system, the critical factors of its successful application and the tools and methodologies used for their application.
In the 6th chapter the model of enterprise description (EFQM), its levels and the positive results obtained from the model application in an enterprise, are described.
The method of Comparative Evaluation, the objectives and profits, the conditions and the process of application along with the tools essentially for its application, are presented in chapter 7th.
Chapter 8th reports the methodologies SEM, ISO, the frame of 7-S methodology, the Performance Prism and the Activity Based Business Modeling for Governments.
Finally, in chapter 9th an attempt is made to compare the most important and effective methods based on a total number of ten criteria, followed by a synopsis of the comparative analysis results, along with a proposed frame of new methodologies.
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Chromatin assembly by CAF-1 during homologous recombination : a novel step of regulationPietrobon, Violena 14 December 2012 (has links) (PDF)
The replication of chromosomes can be challenged by endogenous and environmental factors, interfering with the progression of replication forks. Therefore, cells have to coordinate DNA synthesis with mechanisms ensuring the stability and the recovery of halted forks. Homologous recombination (HR) is a universal mechanism that supports DNA repair and the robustness of DNA replication. Nonetheless, mechanisms regulating HR pathways, such as ectopic versus allelic recombination, remain poorly understood. Another essential pathway for genome stability is the wrapping of newly replicated DNA around nucleosomes, leading to the constitution of a chromatin fibre, which allows the structural organization of the genetic material. In Saccharomyces cerevisiae, deficiencies in chromatin assembly pathways lead to replication forks instability and consequent increase in the rate of HR. Histone chaperones play a crucial role during chromatin assembly, thus I decided to focus on the H3-H4 histone chaperone Chromatin Assembly Factor 1 (CAF-1), to study its role in HR processes in Schizosaccharomyces pombe. Indeed, HR includes a DNA synthesis step and little is known about the associated chromatin assembly. My data excluded a role for CAF-1 in allelic recombination and in the maintenance of forks stability. However, CAF-1 was found to play an important role during ectopic recombination, in promoting chromosomal rearrangements induced by halted replication forks. My data support a model according to which CAF-1 allows the stabilization of early recombination intermediates (D-loop), via nucleosome deposition during the elongation of these intermediates. Doing so, CAF-1 counteracts the dissociation of early recombination intermediates by the helicase Rqh1. Therefore, CAF-1 appears to be part of an equilibrium that regulates stability/dissociation of early steps of recombination events. Importantly, I found that the role of CAF-1 in this equilibrium is of particular importance during non-allelic recombination, revealing a novel regulation level of HR mechanisms and outcomes by chromatin assembly.
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Développement d'empilements métalo-diélectriques pour des applications optiques : conception, réalisation et caractérisationDémarest, Nathalie 12 December 2013 (has links) (PDF)
Les travaux de cette thèse concernent l'étude de l'influence des conditions de dépôt sur la microstructure et les propriétés optiques de monocouches dans le but de réaliser des filtres optiques particuliers commercialisables. La méthode de dépôt utilisée est l'évaporation par canon à électrons avec assistance ionique. L'un des deux projets a été de vérifier la faisabilité de filtres optiques infrarouges dans la gamme [2-15] µm avec des matériaux non toxiques. Les monocouches des trois fluorures étudiées ont montré des comportements différents suivant les conditions de dépôt, notamment suivant la température du substrat qui influe fortement sur leur microstructure. L'association du BaF₂ au germanium, avec des réglages optimisés, montre pour différents filtres réalisés des résultats proches de la théorie. Ces filtres sont donc commercialisables. Le second projet a été de développer une machine de dépôt dans le but de pouvoir réaliser des filtres complexes d'une centaine de couches d'épaisseur variable (de 15 à 300 nm) associant des monocouches de TiO₂ à des monocouches de SiO₂. L'étude de l'influence des paramètres de dépôts (pression, assistance ionique, préchauffage du matériau) au travers différentes caractérisations (MEB, AFM, ellipsométrie) a permis une optimisation des réglages de l'enceinte de dépôt plus efficace et adaptée en fonction des spécifications des filtres optiques à réaliser. Puis, une étude ellipsométrique poussée de l'indice de réfraction des monocouches de TiO₂ en fonction de leur épaisseur a conduit à une nette évolution des résultats pour la réalisation du filtre complexe.
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Estudo da potencialidade da incorpora??o de res?duo de granito e da queima da casca do caf? em cer?mica vermelhaAvelino, Keite Anny Rocha 29 November 2013 (has links)
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Previous issue date: 2013-11-29 / The industrial production of ornamental rocks and the burning of coffee husk generate waste that is discarded into the environment. However, with the study of the incorporation of these residues in ceramic products, may be found an alternative to reducing environmental impacts and detrimental effects on human health caused by its indiscriminate disposal of waste in nature. Thus, this work aimed to study the addition of ashes of the coffee husk and granite residue in matrix of red ceramic. The raw materials were dry milled and sieved to mesh 100. To characterize the raw materials were carried out analyzes of X-ray diffraction (XRD), X-ray fluorescence (XRF), particle size analysis (PSA), differential thermal analysis (DTA) and thermogravimetric analysis (TG). Six formulations were prepared where the clay content was kept constant (70%wt) and ashes contents and granite residue varied from 10, 15, 20 and 30%. Dilatometrics analyzes were performed at four selected formulations, containing them: 100% clay (A100); 70% clay and 30% ashes (A70C30); 70% clay and 30% granite residue (A70G30); and 70% clay, 15% granite residue and 15% ashes (A70G15C15). The samples were prepared by uniaxial compaction with pressure of 25 MPa, and fired at temperatures of 800?C, 850?C, 900?C, 950?C, 1000?C and 1100?C. Assays were performed to determine the linear shrinkage of burning (LSB), water absorption (WA), apparent porosity (AP), density (D) and tensile bending. Also were performed analyzes of X-ray diffraction (XRD) and scanning electron microscopy (SEM) of the samples fired. The formulations incorporating granite residue and/or ashes reached the required limits of water absorption according to NBR 15270-1 and NBR 15310 and tensile bending according to classical literature (SANTOS, 1989) necessary for the production of tiles and ceramic block for masonry sealing / A produ??o industrial de rochas ornamentais e a queima da casca do caf? geram res?duos que s?o descartados no meio ambiente. Por?m, com o estudo da incorpora??o destes res?duos em produtos cer?micos, poder? ser encontrada uma alternativa para a redu??o dos impactos ambientais e efeitos danosos ? sa?de humana causados pelo seu descarte indiscriminado na natureza. Nesse sentido, este trabalho teve como objetivo estudar a adi??o de cinzas da casca do caf? e res?duo de granito na argila usada para a produ??o de cer?mica vermelha. As mat?rias-primas foram mo?das a seco e peneiradas na malha 100 mesh. Para caracterizar as mat?rias-primas foram realizadas as an?lises de difra??o de raios X (DRX), fluoresc?ncia de raios X (FRX), an?lise granulom?trica (AG), an?lise t?rmica diferencial (DTA) e an?lise termogravim?trica (TG). Foram preparadas seis formula??es onde o teor de argila foi mantido constante (70% em peso) e os teores de cinzas e de res?duo de granito variaram de 10, 15, 20 e 30%. Foram realizadas an?lises dilatom?tricas em quatro formula??es selecionadas, contendo elas: 100% argila (A100); 70% argila e 30% cinza (A70C30); 70% argila e 30% res?duo de granito (A70G30); e 70% argila, 15% res?duo de granito e 15% cinza (A70G15C15). As amostras foram confeccionadas por compacta??o uniaxial com press?o de 25 MPa, e queimadas ?s temperaturas de 800?C, 850?C, 900?C, 950?C, 1000?C e 1100?C. Foram realizados ensaios para determinar a retra??o linear de queima (RLq), absor??o de ?gua (AA), porosidade aparente (PA), massa espec?fica aparente (MEA) e tens?o de ruptura ? flex?o (TRF). Foram realizadas tamb?m an?lises de difra??o de raios X (DRX) e microscopia eletr?nica de varredura (MEV) das amostras queimadas. As formula??es com incorpora??o de res?duo de granito e/ou cinza alcan?aram os limites exigidos de absor??o de ?gua segundo as normas NBR 15270-1 e 15310 e de tens?o de ruptura ? flex?o segundo a literatura cl?ssica (SANTOS, 1989), necess?rios para a produ??o de telhas e blocos cer?micos para alvenaria de veda??o
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Adi??o de subprodutos da cinza da casca de caf? (coffea canephora) em massa cer?mica para porcelanatoDultra, Eduardo Jorge Vidal 23 May 2013 (has links)
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Previous issue date: 2013-05-23 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / To produce porcelain tiles fluxing agents are used in order to obtain a liquid phase
during firing. This liquid phase fills the pores decreasing porosity, water absorption
and contributes to material densification. In the porcelain tiles industry, feldspar is the
main flux material used, with quantities ranging between 35 and 50%. Studies focus
on the discovery of materials with flux characteristics that can reduce the
consumption of feldspar by porcelain tiles industry. In this context, the coffee husk
ashes, a residue obtained when coffee husks are burned to produce heat for the
dryers during the processing of the green fruit, have as main chemical constituents
potassium, calcium and magnesium, giving them characteristics of fluxing material.
Brazil is the largest coffee producer in the world and is responsible for over 30% of
the world s production. In this work a physical treatment of coffee husk ash was
carried out in order to eliminate the organic matter and, after this, two by-products
were obtained: residual wastes R1 and R2. Both residues were added separately as
single fluxes and also in association with feldspar in mixtures with raw materials
collected in a porcelain industry located in Dias d ?vila-Ba. The addition of these
residues aimed to contribute to the reduction of the consumption of feldspar in the
production of porcelain tiles. Specimens were produced with dimensions of 60 mm x
20 mm x 6 mm in an uniaxial die with compacting pressure of 45 MPa. The samples
were heated to a temperature of 1200 ?C, for 8 minutes. Tests were performed to
characterize the raw materials by XRF, XRD, particle size analysis, DTA and TGA
and, additionally, the results of the physical properties of water absorption, apparent
porosity, linear shrinkage, density, dilatometry, flexural strength and SEM of sintered
body were analyzed. Additions of less than 8% of the residue R1 contributed to the
decrease of porosity, but the mechanical strength of the samples was not
satisfactory. Additions of 5% the R2 residue contributed significantly to decrease the
water absorption and apparent porosity, and also to increase the mechanical
strength. Samples with addition of feldspar associated with the R2 residue, in
proportions of 6.7% of R2 and 6.7% of feldspar, led to results of water absorption of
0.12% and mechanical strength of 46 MPa, having parameters normalized to the
manufacture of porcelain stoneware tiles / Na fabrica??o de porcelanatos s?o utilizados fundentes com a finalidade de obter
fase l?quida durante a queima que, por sua vez, preenche os poros diminuindo a
porosidade, a absor??o de ?gua, e contribui para a densifica??o do material. Na
ind?stria de porcelanatos o feldspato ? o principal material fundente utilizado, com
percentuais que variam entre 35 e 50% em massa. Pesquisas s?o direcionadas para
a descoberta de materiais com caracter?sticas fundentes que possam diminuir o
consumo de feldspato. Nesse contexto, a cinza da casca de caf?, res?duo obtido
quando cascas de caf? s?o queimadas a fim de produzir calor para os secadores
mec?nicos durante o beneficiamento do fruto, possuem como principais elementos o
pot?ssio, c?lcio e magn?sio, conferindo-lhe caracter?sticas de material fundente. O
Brasil ? o maior produtor de caf? do mundo, respons?vel por mais de 30% da
produ??o mundial. Nesse trabalho, foi realizado um tratamento f?sico na cinza de
caf? com a finalidade de eliminar parte do material carbonizado e, ap?s este, foram
obtidos dois subprodutos: res?duo R1 e res?duo R2. Ambos os res?duos foram
adicionados, separadamente, como ?nicos fundentes, e tamb?m associados ao
feldspato, em massas com mat?rias primas coletadas em uma f?brica de
porcelanatos localizada no munic?pio de Dias d ?vila-Ba. A adi??o desses res?duos
teve o objetivo de verificar a possibilidade de reduzir o consumo de feldspato na
produ??o de porcelanatos. Foram confeccionados corpos de prova com dimens?es
de 60 mm x 20 mm x 6 mm em matriz uniaxial, com press?o de compacta??o de 45
MPa. Os corpos de prova foram sinterizados na temperatura de 1200 ?C com
patamar de 8 minutos. Foram realizados ensaios para caracteriza??o das mat?riasprimas
por FRX, DRX, AG, ATD e ATG, e analisados os resultados das propriedades
f?sicas de absor??o de ?gua, porosidade aparente, retra??o linear, MEA, an?lise
dilatom?trica, resist?ncia ? flex?o e MEV do corpo sinterizado. A adi??o de at? 8%
do res?duo R1 contribuiu para a diminui??o da porosidade aparente, por?m a
resist?ncia mec?nica das amostras n?o foi satisfat?ria. A adi??o de 5% de res?duo
R2 contribuiu significativamente para diminuir absor??o de ?gua e porosidade
aparente, e tamb?m, para o aumento da resist?ncia mec?nica ? flex?o. As amostras
com adi??o do res?duo R2 associado ao feldspato, nas propor??es de 6,7% de R2 e
6,7% de feldspato, obtiveram resultados de absor??o de ?gua de 0,12% e
resist?ncia mec?nica ? flex?o de 46 MPa, atendendo aos par?metros normalizados
para fabrica??o de porcelanatos
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Composi??o qu?mica do caf? do Alto Vale do Jequitinhonha e compara??o dos efeitos sub-cr?nicos da cafe?na e do caf? em ratos / Chemical Composition of the Coffee High Jequitinhonha Valley and Comparison of sub-chronic effects of caffeine and coffee in ratsRodrigues, Iara Ribeiro January 2012 (has links)
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Previous issue date: 2013-02-21 / O caf? est? entre os produtos agr?colas de maior import?ncia no com?rcio internacional e sua qualidade como produto ? um importante fator na forma??o de pre?o, al?m de ser uma das bebidas mais consumidas mundialmente e por isso desperta o interesse para os estudos dos efeitos fisiol?gicos dos seus constituintes. Diante disso, o presente trabalho teve como objetivo avaliar os constituintes a??cares, s?lidos sol?veis totais, fen?licos, flavon?ides, cafe?na e determinar a acidez total, o pH e a atividade antioxidantepor diferentes m?todos (DPPH, ABTS?+ e FRAP) no gr?o de caf? cru. Tamb?m avaliar os efeitos do tratamento sub-cr?nico com cafe?na e caf? no peso corporal e dos ?rg?os (ba?o, cora??o, f?gado, rins, supra renais e test?culos), comprimento dos ossos (f?mur e t?bia), ingest?o de alimentos (s?lidos e l?quidos) e par?metros bioqu?micos (colesterol total, glicemia e triglic?rides) em ratos machos Wistar. Foram utilizados 30 ratos: Controle (C) ? receberam ra??o e ?gua; Cafe?na (CA) ? receberam ra??o e ?gua contendo 0,1% de cafe?na; Caf? 0,1% (CC1) ? receberam ra??o e caf? contendo 0,1% de cafe?na; Caf? 0,05% (CC5) ? receberam ra??o e caf? contendo 0,05% de cafe?na; caf? 0,025% (CC25) - receberam ra??o e caf? contendo 0,025% de cafe?na. As amostras de caf? das safras de 2010 e 2011 analisadas, apresentaram diferen?as significativas para os teores de fen?licos totais, flavon?ides, cafe?na, s?lidos sol?veis, a??cares totais e n?o-redutores, al?m de acidez total e pH. A atividade antioxidante total para os m?todos utilizados (ABTS, DPPH e FRAP) e teor de a??cares redutores n?o variaram significativamente de um ano para o outro. No ensaio biol?gico os animais CC1 pesaram menos do que os C, CC5 e CC25. Em rela??o ao ba?o, os CC5 pesaram menos do que os C e CC25; os CC1 menos do que os C. As supra renais dos CC1 pesaram menos do que as dos Ca e CC25. Os CC1 apresentaram menor peso dos test?culos do que os C, CA, CC5 e CC25 e os CC25 pesaram mais do que os C. Os ratos CC1 apresentaram menor comprimento do f?mur do que os C, CC5 e CC25 e menor t?bia do que os C, CA, CC5 e CC25. Os animais CC25 apresentaram maiores taxas de glicemia do que os CC1 e CC5 e os CC1 maiores taxas de colesterol total do que os C e CC25. Os animais CC1 comeram menos do que os C durante o tratamento e beberam menos na primeira semana. Os resultados obtidos poder?o servir de aux?lio para maior conhecimento sobre a interfer?ncia dos compostos qu?micos na qualidade da bebida de caf? e compreens?o de seus efeitos metab?licos no organismo. / Disserta??o (Mestrado) ? Programa de P?s-Gradua??o em Qu?mica, Universidade Federal dos Vales do Jequitinhonha e Mucuri, 2012. / ABSTRACT
Coffee is among the most important agricultural products in international trade and its quality as a product is an important factor in price formation, besides being one of the most widely consumed beverages worldwide and therefore arouses interest for studies of the physiological effects of its constituents. Thus, the present study was to evaluate the constituent sugars, soluble solids, phenolics, flavonoids, caffeine and determine the total acidity, pH and activity antioxidantepor different methods (DPPH, FRAP and ABTS ? +) in raw coffee beans . The objective was also to evaluated the effects of sub-chronic treatment with coffee and caffeine on body weight and organs (spleen, heart, liver, kidneys, adrenals and testicles); bone?s length (femur and tibia); food intake (solid and liquid) and biochemical parameters (total cholesterol, glucose and triglycerides) in male Wistarrats.A total of 30 rats were used: Control (C) - received food and water; Caffeine (CA) - received food and water containing 1% caffeine; Coffee 1% (CC1) - received food and coffee containing 1% caffeine; Coffee 0.05% (CC5) - received food and coffee containing 0.05% caffeine; coffee 0.025% (CC25) - received food and coffee containing 0.025% caffeine. Samples of coffee crop in 2010 and 2011 analyzed showed significant differences in the levels of total phenolics, flavonoids, caffeine, soluble solids, total sugars and non-reducing sugars, and total acidity and pH. The total antioxidant activity for the methods (ABTS, DPPH and FRAP) and reducing sugars did not vary significantly from one year to another. In the biological tests the animals CC1 weighed less than the samples C, CC25 and CC5.Regarding the spleen, CC5 weighed less than C and CC25; the CC1 less than C.The adrenal glands of CC1 weighed less than that of the Ca and CC25.The CC1 testicles weighed less than C, CA, CC5 and CC25; and CC25 were heavier than C.The CC1 rats had lower femur length than C, CC5 and CC25; and lower tibia than the C, CA, CC5 and CC25.The CC25 animals showed higher rates of glucose than the CC1 and CC5; and CC1 higher total cholesterol than the C and CC25.CC1 animals ate less than C during the treatment and drank lessduring the first week.The results obtained may serve as an aid to improve the quality of coffee beverage and the understanding of its metabolic effects in the body.
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Incorpora??o de cinzas da casca de caf? na produ??o de placas cer?micas para revestimentoDultra, Eduardo Jorge Vidal 12 January 2010 (has links)
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Previous issue date: 2010-01-12 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / Brazil is the world s leading coffee producer. In 2008, 45.99 million of 60 kg bags of benefited coffee were produced. In the process of improvement 50% is grain and 50% is husk, thus, 1.38 million tons of coffee husk are produced annually. The
husk is used as combustible in the drying and improvement ovens in the coffee farms, generating ash as residue. These ashes contain a high concentration of alkaline metals and earth metals, mainly K2O and CaO. This work studies the use of
this residue in the ceramic tiles industry, as fluxing agents in substitution to the feldspar. Ten mixtures with equal ratios of clay and kaolin, proceeding from Bahia and the residue (varying from 30 to 5%) were defined and produced in uniaxial tool
die of 60x20mm with approximately 5 mm of thickness and 45MPa compacting pressure. The samples were fired in four different temperatures: 1100 ?C, 1150 ?C, 1185 ?C and 1200 ?C during 60 minutes and characterized by means of X-ray fluorescence, X-ray diffraction, gravimetric thermal analysis and differential thermal analysis. The results of water absorption, apparent porosity, linear shrinkage, XRD, dilatometry, flexural strength and SEM were also analysed. The test specimen with
addition of 10% of ash fired in 1200 ?C resulted in 0.18% water absorption and 40.77 MPa flexural strength, being classified as porcelain stoneware tiles according to ABNT, UNI and ISO norms / O Brasil ? o maior produtor mundial de caf?. Em 2008 foram produzidas 45,99 milh?es de sacas, de 60 Kg, de caf? beneficiado. No processo de beneficiamento 50% ? gr?o e 50% ? casca. Assim, 1,38 milh?es de toneladas de cascas de caf? s?o produzidas anualmente. A casca ? utilizada como combust?vel nos fornos de secagem e beneficiamento nas fazendas de caf?, gerando uma cinza como res?duo. As cinzas da casca de caf? apresentam altas concentra??es de metais alcalinos e alcalinos-terrosos, principalmente K2O e CaO. Este trabalho estuda a utiliza??o deste res?duo na ind?stria de placas cer?micas para revestimentos, como fundente, em substitui??o ao feldspato. Foram definidas 10 formula??es com iguais propor??es de argila e caulim provenientes da Bahia, e o
res?duo (variando de 30 a 5%), e confeccionados corpos-de-prova em matriz uniaxial de 60x20mm com aproximadamente 5 mm de espessura, com press?o de compacta??o de 45Mpa. As amostras foram sinterizadas em quatros patamares de temperatura, 1100 ?C, 1150 ?C, 1185 ?C e 1200 ?C durante 60 minutos. Foram realizados ensaios para caracteriza??o das mat?rias-primas por fluoresc?ncia de raios-X, difra??o de raios-X, AG, ATD e ATG e analisados os resultados de absor??o
de ?gua, porosidade aparente, retra??o linear, DRX, an?lise dilatom?trica, resist?ncia ? flex?o e MEV. Os corpos de prova com adi??o de 10% da cinza e sinterizados a 1200 ?C obtiveram resultados de absor??o de ?gua de 0,18% e resist?ncia ? flex?o de 40,77 MPa, o que segundo as normas ABNT, UNI e ISO
podem ser classificados como gr?s porcelanato
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