95 resultados para Pt-based catalysts


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This paper describes a method for leaf vein shape characterization using Hermite polynomial cubic representation. The elements associated with this representation are used as secondary vein descriptors and their discriminatory potential are analyzed based on the identification of two legume species (Lonchocarpus muehlbergianus Hassl. and L. subglaucescens Mart, ex Benth.). The elements of Hermite geometry influence a curve along all its extension allowing a global description of the secondary vein course by a descriptor of low dimensionality. The obtained results shown the analyzed species can be discriminated by this method and it can be used in addition to commonly considered elements in the taxonomic process.

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This study subject to investigate the floristic composition and richness, the reproductive phenological patterns, the dispersal syndromes and life forms of species of a disjunt cerrado in semiarid climate at Araripe plateau during a one year period. We found 107 species and 41 families. Fabaceae, Myrtaceae, Poaceae, Apocynaceae, Euphorbiaceae and Malpighiaceae showed the largest number of species. For 47 of the woody species found, we studied the geographical distribution based on 27 papers of the Brazilian cerrados. Twelve species are of widespread occurence in the cerrado, and 13 are restricted to the Araripe plateau. Zoocory, autocory, and anemocory are the predominant syndromes of dispersal. The predominant life forms were phanerophytes (50.7%), hemicriptophytes (14.9%) and camephytes (13.1%). The cerrado of Araripe have lower species richness than continous cerrados, but a similar pattern of reproductive phenology, dispersal syndromes and life forms in more humid zones.

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A study of the tree species of the order Celastrales sensu Cronquist from the Tibagi river basin, Paraná state, Brazil, is presented, based on herbarium material. This basin is subdivided into three zones, from north to south: lower Tibagi (BT), mid Tibagi (MT) and upper Tibagi (AT), each with different environmental conditions and vegetation types. The order Celastrales is represented in the basin by 15 tree species belonging to three families: Aquifoliaceae, Celastraceae and Icacinaceae. Icacinaceae has only two species, Citronella gongonha and C. paniculata. The former is distinguished by a glabrous ovary and leaves that usually bear thorns. Aquifoliaceae has six species: Ilex brasiliensis, I. brevicuspis, I. chamaedryfolia, I. dumosa, I. paraguariensis and I. theezans. These species are found mainly in AT and MT and are distinguished by leaf size, indument, apices and margins, and by sepal features. Celastrales is represented by seven species and two genera; Plenckia populnea, a Brazilian savannah species found only in MT, and six species of Maytenus (M. evonymoides, M. robusta, M. dasyclada, M. salicifolia, M. ilicifolia and M. aquifolia) distinguished by leaf size and margins, branch shape and number of flowers per inflorescence.

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The taxonomy of the genus Heliotropium L. in Brazil was studied, revealing nine species and two varieties: H. amplexicaule Vahl, H. angiospermum Murray, H. curassavicum L., H. curassavicum var. argentinum I.M. Johnst., H. elongatum (Lehm.) I.M. Johnst., H. elongatum var. burchellii I.M. Johnst., H. indicum L., H. leiocarpum Morong, H. nicotianaefolium Poir., H. phylicoides Cham. and H. transalpinum Vell. Descriptions, illustrations, comments on relationships based on morphology and data on species distribution are presented.

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The study assessed phloem canal development and ultra-structure in shoot apices of Spondias dulcis G. Forst., phloematic canal ultra-structure in shoot apices of Tapirira guianensis Aubl., and floral canal ultra-structure and development and fruit canal ultra-structure of the latter specie. The flower and fruit canals of Anacardium humile St.Hil. were also studied ultra-structurally. The canals in shoot apices of S. dulcis show schizo-lysigenous formation and the floral canals of T. guianensis show schizogenous development. Epithelial cells of S. dulcis and T. guianensis canals have rough endoplasmic reticulum, free ribosomes, elongated plastids of several shapes with osmiophilic inclusions and dictyosomes with production of vesicles. Such organelles participate in the secretion of a heterogeneous exudate, which is comprised of hydrophilic and lipophilic substances. The epithelial cells of the fruit of A. humile present elongated plastids with circular membrane system, which are involved in the synthesis of lipophilic substances. The results of the ultra-structural analyses of the epithelial cells corroborate the results previously obtained in a histochemical study. In the histochemical study, lipophilic and hydrophilic substances were identified in the canals of T. guinanensis and S. dulcis and only lipophilic substances were identified in the canals of A. humile. Based on the ultrastructural aspects of the secretory canals of T. guianensis and S. dulcis we concluded that the plastids of the epithelial cells of the two species are different although they produce secretion of similar composition. A new record for the family is the presence of a great number of circular plastids in epithelial cells of the fruit of Anacardium humile. The pattern found in the secretory canals of the studied species is the ecrine type of secretion release.

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A revision of the Brazilian species of Lonchocarpus s. str. is presented. This study is based on field observation and an analysis of approximately 1,200 herbarium collections. Nine species are recognized, L. cultratus, L. hedyosmus, L. latifolius, L. macrocarpus, L. nitidus, L. pluvialis, L. sericeus, L. spiciflorus, and L. violaceus, which grow in forests and are usually associated with river banks. Lonchocarpus sericeus and L. cultratus have a wide distribution throughout Brazil, whereas L. hedyosmus, L. macrocarpus, L. spiciflorus, and L. latifolius are restricted to the Amazonian domain. Lonchocarpus pluvialis occurs in the Central-West (Mato Grosso do Sul and Goiás) and Southeast (São Paulo) regions. Lonchocarpus violaceus is found in the states of Bahia and Espírito Santo, and is reported for the first time for Brazil. Identification keys, descriptions, and illustrations, in addition to information about habitat, geographic distribution and taxonomic and nomenclatural comments, are provided for the species. Four new synonyms and five lectotypifications are proposed.

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Epilepsy is a common chronic condition in the childhood and its diagnosis reveals psychological, social and family difficulties, that seem to be related with beliefs and quality of parents-children interaction. The purpose of this paper is to schematize investigation strategies for the psychological variables: beliefs, impact of the disease, family relationship, identification of changes. Based upon collected reports of epileptic children's parents and upon surveyed aspects of the literature, psychological questionnaires were elaborated to identify important variables that affect the child's epilepsy life and his family. The use of more appropriate investigation procedures facilitates the psychological evaluation and ensures the collection of data.

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The objective of this study was to analyze the point of view of parents in relation to the cochlear implant, their level of information concerning the implant, its risks and benefits, and their expectations towards their children's future. Ten parents of deaf children candidate for the cochlear implant at Unicamp's Clinical Hospital were interviewed. Based on a qualitative approach, a content analysis showed that the majority of parents seek the cure for deafness, and consequently, the acquisition of speech with the cochlear implant. For these families, the cochlear implant is seen both as the solution to their children's deafness and as a path for a better future. It has been evidenced that during the acquisition of knowledge about the implant, parents experienced anxiety and anguish when faced with the risks and benefits of the procedure, and the need to choose between performing and not performing the cochlear implant.

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The aim of this paper is to discuss some rhythmic differences between European and Brazilian Portuguese and their relationship to pretonic vowel reduction phenomena. After the basic facts of PE and PB are presented, we show that the issue cannot be discussed without taking into account secondary stress placement, and we proceed to present the algorithm-based approach to secondary stress in Portuguese, representative of Metrical Phonology analyses. After showing that this deterministic approach cannot adequately explain the variable position of secondary stress in both languages regarding words with an even number of pretonic syllables, we argue for the interpretation of secondary stress and therefore for the construction of rhythmic units at the PF interface, as suggested in Chomsky s Minimalist Program. We also propose, inspired by the constrain hierarchies as proposed in Optimality Theory, that such interpretation must take into account two different constraint rankings, in EP and BP. These different rankings would ultimately explain the rhythmic differences between both languages, as well as the different behavior of pretonic vowels with respect to reduction processes.

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This paper studies complex sentences with temporal hypotatic clauses and with conditional hypotatic clauses in order to investigate the degree of grammaticalization shown by these two kinds of utterances. Our hypothesis is that the more the hypotatic clause is integrated to the nuclear clause, the greater is the degree of grammaticalization. Such degree of integration was measured according to three groups of factors, and the results show that, regarding two of the variables evaluated, the conditional clauses are the most integrated to their nucleus, but, in another rank of evaluation, the temporal clauses are the most integrated ones. Considering that this study is based on a functionalist view, the results may be interpreted according to the principle that there is a competition of motivations in the use of language, so that each utterance reflects the balance of such forces.

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The acquisition of Portuguese by two Brazilian children (aged 2;0 -5;0) is discussed in an attempt to describe and explain the first relative clauses produced in naturalistic, observational studies, according to the framework of generative syntax theory. The results show that at around 3;0: a) the child starts to deal with relative clauses as modifiers of N; b) cleft sentences appear before relative clauses, and c) the first relatives confirm the prevalence of the vernacular strategy of relativization in Brazilian Portuguese identified by other studies based on adult data.

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In this article my main objective is to approach some questions related to the tests used in psychodiagnostics processes of children who are considered as having learning difficulties. Having the book Discipline and Punish (1975/1986) by Foucault as theoretical basis, I intend to investigate the hypothesis that the child is considered ill or abnormal due to the factors related to imposed norms and not to organic aspects and/or neurological pathology. My interest is to analyse the signs that allow us to point out the written language conception of tests. This language is expected and privileged, however it may not be the language that the child uses and experiences every day.

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This article aims at discussing about the foreign language teaching to young learners, taking the principles of the Sociocultural Theory (Vygotksy, 1978) and of the Communicative Approach (Almeida Filho, 1993, 2005) related to Primary English teaching (Cameron, 2001; Brewster, Ellis & Girard, 2002) as a theoretical references. Considerations about the importance of language learning in childhood will be made, as well as about the role of the grammar, oral language and mother tongue in the process. Likewise, the importance of Teacher Education will be briefly approached. This work is ended with the discussion about some possible procedures in the language teaching processes followed by a brief presentation of possible guidelines based on the bakhtinian notion of discourse genres.

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This work indicates presuppositions for the qualitative research in Physical Education, starting with a literature review based on the cultural frame of reference. Firstly, we introduce the debate concerning the natural and the human sciences and implications for the Physical Education; we then use a cultural axis as a ground basis for the research in the area, proposing the 'dense description' as a possibility for knowledge building; finally, we bring up examples of studies conducted with such an approach. This theoretical methodological approach allows the study of the human being as a cultural being, thus opposed to the naturalised view of a human - predominant in Physical Education.

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The presence of vegetal impurities in sugarcane delivered to sugarmills as green and dry leaves is a problem not only because they are non-value materials to be processed along with sugarcane stalks, but also because they can rise the color of the clarified juice and, consequently, the color of the sugar produced, with a reduction of its quality for the market. Another problem is the mud volume sedimented in the clarifiers, which also can result in a larger recirculation and greater volume of filtrate juice, with higher losses of sucrose and utilization of the vacuum rotary filters. The objective of this work was to observe the effect of the presence of green and dry leaves on sugarcane juice clarification, related to a control treatment with the addition of fiber extracted from the stalks. The experiments were planned based on the addition of quantities of fibrous sources in order to formulate samples with absolute increase of 0.25 , 0.50 and 0.75 percentual points over the fiber content of the sugarcane stalks (control treatment). The juice clarification was conducted with a laboratory clarifier. The clarified juice color and the mud volume were evaluated. The presence of green leaves caused higher color and mud volume due to the extraction of non-sucrose components of the leaves. Soluble compounds of dry leaves were also extracted, though not detected by juice analysis. The addition of the fiber extracted from the stalks did not induce alterations in the clarification process.