This study used an aqueous dispersion of silanized colloidal silica (SCS), whose particles’ surfaces were modified with an epoxysilane-based coupling agent, as the liquid medium and binder for MgO-Al2O3-containing suspensions. Fine calcined alumina and magnesia sinter particles were dispersed in SCS to form a 65 vol% solids suspension. Equivalent silica-free compositions containing calcium aluminate cement or unsilanized colloidal silica were tested as references. After mixing, the SCS-suspension showed low viscosity and suitable workability and, after curing, a thin protective coating of magnesium silicate hydrate (MSH) was formed, thus preventing MgO hydroxylation and improving bonding strength, generating green-dried structures of significant flexural strength (8 MPa). During initial heating, the decomposition of MSH and the softening of amorphous silica particles reduced the overall expansion of spinel (MgAl2O4) formation. After sintering at 1600ºC, the structure showed intense densification (total porosity of 8%) high flexural strength (73 MPa) and large spinel crystals surrounded by a thin layer of amorphous silica and magnesium silicates. SCS, , (SCS) epoxysilanebased epoxysilane based agent MgOAl2O3containing MgOAlOcontaining Al2O3 Al O suspensions 6 vol suspension silicafree free references mixing SCSsuspension curing (MSH formed greendried green dried 8 ( MPa. MPa . heating MgAl2O4 MgAlO MgAl (MgAl2O4 formation 1600ºC ºC total 8% 73 (7 silicates (SCS MgOAl AlO Al2O MgAl2O (MgAl2O 7

Abstract The magnesia (MgO) hydroxylation behavior in dilute suspensions (below 50% volumetric solid loads) has been extensively studied over the past decades due to its role in refractory castables. However, its equivalent effects on concentrated systems have not been analyzed in such a systemic way, although they are known to be as or more deleterious than those observed in dilute systems. This study focuses on the hydroxylation behavior of different sources of magnesia (sinter and caustic magnesia) in aqueous suspensions prepared at various solids concentrations (17-96 vol%) and shaped by distinct methods. They were analyzed by thermogravimetry, apparent volumetric expansion measurements, X-ray diffraction, scanning electron microscopy, and in situ temperature measurements during curing. The ratio between experimental and theoretical extents of the hydroxylation degree resulted in the reaction yield. A comparison between samples containing the same water amount revealed those with caustic magnesia showed a faster evolution of hydroxylation degree, apparent volumetric expansion, and higher maximum internal temperature during curing. In both systems, the yield levels of compositions of heavier solid loads were higher, despite the small quantity of hydroxylation products formed. Significant differences in the products’ microstructure were observed and related to the ions' mobility toward crystallization nuclei.

ABSTRACT Loss of large trees due to indiscriminate timber cutting and opening of new areas for human use is a global problem. Brazil is well known for tree species richness within its extensive forested areas composed of various biomes. Giant trees are “key” to recognize the original forest structure. Decline of their populations in Brazil may be estimated by comparing data of the National Forest Inventory (NFI) with those of regional data and other surveys. In fact, Santa Catarina is the first state in Brazil to have currently completed its forest inventory. However, only few large trees were sampled systematically. Recognition of the maximum tree growth is important for their ecological management and tourism potential. Public policies for cataloging and management of these resources must be developed before it is too late.

The in situ reaction between alumina and silica to obtain mullite (Al6Si4O13) can be significantly affected by using synthetic amorphous silica (SAS) sources instead of crystalline ones (quartz and cristobalite). For instance, SASs promote early mullite formation (below 1300°C) and greater densification during sintering. This paper reports the "in situ" formation of mullite-alumina structures from fine calcined alumina (α-Al2O3) and four grades of SAS of different particles' morphology, specific surface area and internal porosity. After sintering assisted by dilatometry (up to 1500°C), the samples' total porosity, density and flexural strength were measured. The relative density and strength levels of some of these structures were greater than or comparable to other studies in which similar compositions were sintered at higher temperatures (1600-1700°C). Their microstructure assessment indicated that the specific surface area and internal porosity of SAS particles showed a major influence in the development of these physical properties.

Resumo: O objetivo do trabalho foi analisar as formas de governança do Arranjo Produtivo Local (APL) da castanha-do-brasil (Berthollethia excelsa Bonpl.) na região da Calha Norte, do estado do Pará, caracterizando os fatores específicos que condicionam a governança. Os dados foram obtidos por meio de questionário estruturado no padrão RedeSist, aplicados aos agentes da cadeia produtiva local, com ênfase nas empresas de beneficiamento de castanhas. A análise dos resultados foi desenvolvida com base nos índices de percepção dos entrevistados sobre a estrutura, a governança e as vantagens associadas ao ambiente local, fundamentada nas teorias das aglomerações produtivas, competitividade e governança. Os resultados mostram que pela grande concorrência existente entre as empresas, as transações comerciais realizadas localmente promovem internalização de conhecimento e aprendizagem de forma individual, não se desdobrando em geração de informação para o APL como um todo, em que os processos de cooperação e aprendizagem têm decorrido basicamente da experiência acumulada na produção e consequentes inovações incrementais em produtos e processos, caracterizando, assim, uma capacidade inovativa interna das empresas. Conclui-se que há baixa capacidade de gestão e governança nas ações cooperativas de forma sistêmica e, na ausência de estruturas de governança mais especializadas, predomina a governança de mercado no APL estudado.

Abstract: The objective of this work was to analyze the forms of governance on the Local Productive Arrangement (APL) of Brazil nut (Berthollethia excelsa Bonpl.) in the Calha Norte region, state of Pará, characterizing the specific factors that influence the governance, emphasizing the main underlying theoretical approaches. The data were obtained by means of a structured questionnaire in standard RedeSist, applied to agents of the local productive chain, with emphasis to the Brazil nuts processing companies. The analysis of the results has been developed on the basis respondent’s perception indices on their structure, governance and the advantages associated with the local environment and based on theories of productive agglomerations, competitiveness and governance. The great competition among companies for processing business transactions locally promotes internalization of knowledge and learning individually, not unfolding a generation of information to APL as a whole, in which the processes of cooperation and learning have basically passed the accumulated experience in the production and consequential incremental innovations in products and processes, thus characterizing an internal capacity of the innovative companies. It was concluded that there are low capacity of management and governance at the systemic form cooperatives and actions, and even in the absence of more specialized governance structures, there is a predominance of market governance in the APL studied.

ABSTRACTNumerous papers and publications report the use of microporous calcium hexaluminate (CaO.6Al2O3; CA6) as a key raw material for high temperature insulating materials. This material has unique properties with respect to chemical purity and mineral composition. Another important property of CA6 is its structure, which consists of platelet-shaped crystals that interlock. The free distance between the crystals defines the microporous structure. The low density in combination with the micropores hampers heat transfer by radiation at temperatures exceeding 1000 oC and results in a low thermal conductivity. Given the advantages presented by this material, it is necessary to understand the formation mechanism of CA6 grains in order to better develop the potential applications of this material. CA6 can be fabricated using organic binders to consolidate the Al2O3-CaCO3 powder mixture and to provide green strength so that a green body can be formed and retains the desired shape before heating. However, these organic binders must be completely thermally decomposed so that they do not remain in the sintered body as carbon or ash. Moreover, the use of organic binders releases large volumes of gases such as carbon dioxide from the green body during heating. Therefore, an eco-friendly ceramic fabrication process has been developed that employs an inorganic binder (hydraulic alumina). The aim of the present work was to study the synthesis of porous calcium-hexaluminate ceramics using calcined alumina or hydraulic alumina combined with different sources of calcia (CaCO3 and Ca(OH)2) at different temperatures. The materials produced were characterized by X-ray diffraction, scanning electron microscopy, apparent porosity and mercury intrusion porosimetry. The materials produced by hydraulic alumina presented higher porosity and larger pores compared to those produced from calcined alumina

Objetivou-se neste trabalho avaliar a densidade de plantio, a mortalidade e o incremento periódico anual (IPA) do crescimento em diâmetro e em altura das espécies empregadas no reflorestamento de áreas de restauração florestal, após a lavra de minério em unidade de conservação na Amazônia. Foram também analisadas as práticas edáficas nas áreas de plantio. O monitoramento abrangeu um período de 13 anos (1996 a 2009), na Floresta Nacional de Saracá Taquera, em Porto Trombetas, PA. As espécies foram distribuídas em classes de mortalidade e de incrementos em diâmetro e em altura. Foi analisada a aptidão ecológica baseada na mortalidade e nos incrementos do crescimento, em diâmetro e em altura, das espécies do ecossistema artificial sob restauração. O incremento periódico anual do diâmetro foi classificado como de graus ótimo, alto, baixo e muito baixo, envolvendo, respectivamente, 7, 17, 44 e 1 espécies. Analogamente, quanto à altura, foram classificadas 7, 33, 20 e 9 espécies, respectivamente. A aptidão ecológica das 69 espécies presentes, durante os 13 anos do monitoramento, identificou 24 espécies classificadas como inaptas, 21 como de baixa, 25 como regular, 16 como boa e apenas três como de ótima adaptabilidade. As práticas de caráter edáfico devem ser revistas, por apresentar indícios de estarem influenciando fortemente a mortalidade e desenvolvimento das árvores plantadas nas áreas de restauração.

The objective of this paper was to evaluate density of planting, of mortality and annual periodic increment (API) of growth in diameter and height of species used in reforestation in areas of forest restoration after mining in conservation units in Amazonia. It was also analyzed the soil management practices in plantation areas. The monitoring covered a period of 13 years (1996-2009), at the National Forest Saracá Taquera, in Porto Trombetas, Pará State, Brazil. The species were distributed in classes of mortality. We analyzed the size and the ecological suitability, based on mortality and growth increments (diameter and height) of the species in the artificial ecosystem restored. The annual periodic increment of diameter considering the studied species allowed the following classification: excellent (7 species), high (33), low (20) and very low (9) and similarly, the grow of tree height it was found: excellent (9 species), superior (20), low (31) and very low (9). The ecological aptitude of 69 species in the study area, based on mortality and the increments in diameter and height, allowed the identification of the following groups of species aptitude: excellent (3), good (16), regular (25), low (21); improper (20) and inept (5). The use of soil practices during the activities of restoration should be reviewed due to strong evidence of mortality and growing of planted trees being influenced by soil storage time, the amount of top soil spread superficially, the acidity and fertility of soil and the top soil depth and the distance of transport to the target areas.

Duas teorias em ecologia explicam a distribuição de espécies em florestas tropicais: a Teoria Neutra e a Teoria do Nicho. Na primeira a distribuição de espécies está relacionada a processos como dispersão, enquanto a segunda prediz que é devido às interações competitivas entre as espécies. Estudos demonstram que a similaridade de espécies de uma comunidade vegetal diminui com a distância geográfica nas regiões tropicais. O objetivo deste estudo foi identificar se a distância influencia nos padrões de riqueza e composição de espécies de árvores dentro e entre seis platôs em uma floresta ombrófila densa na Floresta Nacional Sacará-Taquera, Pará, Brasil. Esses platôs são explorados para a extração da bauxita, onde a cobertura florestal é totalmente removida. O número de parcelas (10 × 250 m) analisadas nesse estudo, em cada platô variou de 18 a 22. Houve uma correlação negativa da similaridade de espécies em relação à distância, tanto dentro como entre os platôs. Não houve correlação da riqueza de espécies em relação à distância, dentro e entre os platôs, com exceção do platô Aramã. Os resultados desse estudo corroboram a Teoria Neutra e têm grandes implicações para a conservação.

Two theories in ecology explain species distribution in tropical forests: the Neutral Theory and Niche Theory. The first predicts the species distribution is related to processes such as dispersion, and the second predicts that species distribution is related to competitive interactions between species. Studies have shown that the species similarity in a plant community decreases according to the geographical distance in the tropics. The aim of this study was to assess the influence of the distance on tree species richness and composition within and among six plateaus in a tropical rain forest at the Sacará-Taquera National Forest, Pará, Brazil. These plateaus are exploited for the bauxite extraction where the forest cover is completely removed. In this study, the number of plots used in each plateau ranged from 18 to 22. There was a negative correlation of the species similarity to the distance, whithin and among the plateaus. There was no correlation of species richness to distance (whithin and among the plateaus), except for the plateau Aramã. The results of this study support the Neutral Theory and have important implications for the conservation as well.

RESUMO A identificação de espécies-chave que influenciam a ocorrência das demais espécies associadas é de fundamental importância para o sucesso da restauração florestal em áreas degradadas. Objetivou-se neste trabalho apresentar um índice fitossociológico e socioeconômico (IFSE), obtido por técnicas de análise fatorial, cujo modelo envolveu seis variáveis quantitativas (abundância, frequência, dominância, biomassa, valor comercial da madeira e quantidade de produtos florestais não madeireiros) e igual número de variáveis qualitativas, cuja variável dummy assumiu valor igual a 1 para aquelas espécies cujos maiores valores acumulados equivaleram a 50 % do total para cada uma das variáveis quantitativas analisadas. A amostra para o inventário florestal em 407 ha de floresta ombrófila densa foi composta por 80 parcelas de 0,25 ha (4,91 % de intensidade amostral) onde todos os indivíduos com diâmetro a 1,30 m do solo (DAP) ≥ 10 cm foram identificados e mensurados. Foram registrados 10.105 indivíduos, distribuídos em 493 espécies, abrangendo 58 famílias. As espécies foram ranqueadas através do índice proposto em três categorias de prioridade fitossociológica e socioeconômica (alta, média e baixa). A adequação da análise fatorial foi determinada pelos testes Bartlett e KMO. O teste de Bartlett avaliou a significância geral da matriz de correlação indicando que as correlações, em geral, são significantes ao nível de 1 % de probabilidade. O teste KMO, indicou que as variáveis estão correlacionadas e o modelo fatorial apresentou um nível muito bom de adequação aos dados. Estes resultados respaldaram o emprego da análise fatorial para a extração de fatores e a estimação dos escores fatoriais. Os resultados foram estatisticamente validados para a construção do IFSE e, 25 espécies foram selecionadas como prioritárias (espécies-chave). Recomendou-se a densidade de plantio para essas espécies florestais na recuperação de áreas degradadas na Amazônia.

ABSTRACT The identification of species influencing the occurrence of other associated species is of fundamental importance for the success of forest restoration of degraded areas. The objective of this work is to present a phytosociological and socioeconomic index (IFSE), obtained by techniques of factor analysis, modeling six quantitative variables (abundance, frequency, dominance, biomass, the commercial value of timber and amount of non-timber forest products) and equal number of qualitative variables, whose dummy variable is equal to one, assumed value for those species whose higher earnings amounted to 50 % of the total for each quantitative variables analyzed. Sampling of the dense rain forest (407 ha) was composed by 80 plots of 0.25 ha (4.91 % of sampling intensity) and all individuals with diameter at 1.30 m above the ground (DBH) ≥ 10 cm were identified and measured. It was recorded 10,105 individuals, including 493 species covering 58 families. The species were ranked by the index proposed in three categories of priority phytosociological and socioeconomic status (high, medium and low). The appropriateness of factor analysis was determined by tests of Bartlett and KMO. The Bartlett's test evaluated the overall significance of the correlation matrix and indicated that correlations were significant at 1 % probability. The KMO test showed that the variables were correlated and the model of variance showed a very good level of fitness to the data. These results endorsed the use of factor analysis to extract factors and estimate the factor scores. The results were statistically validated for construction of the index IFSE and 25 species were selected as the priority ones (key species). And also, it was recomended the planting density for these forest species for restoration of degraded areas in Amazonia.

Na Amazônia, vários empreendimentos minerários estão situados em unidades de conservação. A restauração ecológica após a lavra do minério abrange vários atributos. Entre esses, destaca-se a necessidade de o ecossistema restaurado conter um conjunto de espécies-chave de ocorrência no ecossistema de referência e, dessa forma, proporcionar estrutura apropriada de comunidade, além de ser constituído do maior número possível de espécies nativas. Objetivou-se, neste trabalho, analisar um índice fitossociológico e socioeconômico (IFSE), obtido por técnicas de análise multivariada. O modelo envolveu seis variáveis quantitativas (abundância, frequência, dominância, biomassa, valor comercial da madeira e quantidade de produtos florestais não madeireiros) e igual número de variáveis qualitativas. Em uma área de floresta ombrófila de 1.321 ha, foram amostradas 315 parcelas de 0,25 ha, em que todos os indivíduos com DAP > 10 cm foram identificados e mensurados. Foram registrados 36.298 indivíduos, distribuídos em 898 espécies, abrangendo 62 famílias. As espécies foram ranqueadas através do índice proposto em três categorias de prioridade fitossociológica e socioeconômica (alta, média e baixa). A adequação da análise fatorial foi determinada pelos testes de Bartlett e KMO. O teste de Bartlett avaliou a significância geral da matriz de correlação a 1% de probabilidade. O teste KMO indicou que as variáveis estão correlacionadas, e o modelo fatorial apresentou nível muito bom de adequação aos dados. O uso de análise multivariada foi estatisticamente validado para o emprego do IFSE. Entre as 898 espécies analisadas, 25 foram selecionadas como prioritárias (categorias alta e média), sendo reconhecidas como espécies-chave. Foi estimada a densidade de plantio dessas espécies para recuperação de áreas mineradas na Amazônia, com condições biológicas e ambientais semelhantes às relatadas neste estudo. A distribuição diamétrica das espécies-chave foi analisada e comparada com a da floresta inventariada. O estágio sucessional das espécies-chave foi também analisado.

In the Amazon, several mining companies are located in protected areas. Ecological restoration after mining should consider several attributes. Among these, there is the need of the restored ecosystem to contain a set of key species that occur in the reference ecosystem, and thus, provide an appropriate structure of the community, and as much as possible a greatest number of native species. The objective of this work was to analyze a phytosociological index and socioeconomic status (IFSE), obtained by multivariate analysis. The model included six quantitative variables (abundance, frequency, dominance, biomass, commercial value of timber and amount of non-timber forest products) and an equal number of qualitative variables. In a rain forest area of 1,321 ha, 315 plots of 0.25 ha were sampled where all trees with DBH > 10 cm were identified and measured. It was identified 36,298 individuals, distributed in 898 species, and comprising 62 families. Using the proposed index the species, they were ranked in three categories of priority- phytosociological and socioeconomic (high, medium and low). The appropriateness of factor analysis was determined by KMO and Bartlett tests. The Bartlett test evaluated the general significance of the correlation matrix at the level of 1% probability. The KMO test showed that the variables are correlated and factor model presented a very good fit to the data. The use of multivariate analysis was statistically validated using the IFSE. Among the 898 species analyzed, 25 were selected as priorities (high and medium categories) and are recognized as key species. It was estimated the planting density of these species for recovery of mined areas in the Amazon, with biological and environmental conditions similar to those reported in this study. The diameter distribution of key species was analyzed and compared with the forest inventoried. The successional stage of key species was also analyzed.

Objetivou-se neste trabalho avaliar a dinâmica florestal, sobretudo da regeneração natural, em um fragmento de floresta tropical primária, entre 1998 c 1999, em Peixe-Boi (PA). Foram demarcadas três parcelas permanentes (1 ha cada) onde todos os indivíduos com DAP ≥ 10 cm foram registrados; os indivíduos com 10cm ≥ DAP ≥ 5cm foram amostrados em 6.000 m2, aqueles entre 5cm ≥ DAP ≥ 2cm em 2.400 m2 e com DAP ≤ 2cm em 240 m2. Foram estimados 143.000 indivíduos, desde plântulas até árvores pertencentes a 337 espécies e 76 famílias. Mimosaceae foi a família de maior riqueza (44 espécies); 14 famílias ocorreram com uma única espécie sendo que metade delas apresentaram também um único indivíduo. Independentemente da classe diamétrica verificou-se o egresso de 56 espécies versus o ingresso de 68, gerando um ganho líquido de 12 espécies. A dinâmica da composição e da abundância da regeneração natural foi muito intensa. Observou-se a saída de uma família face ao ingresso de outras 14, aumentando cm quase 30% o número de espécies. A maior mortalidade foi verificada em Bauhinia cf. rutilans e Mabea aff. speciosa (300 e 21 indivíduos). Rinorea negleta e Leçythis idatimon recrutaram 171 e 89 espécimes. A razão recrutamento/ mortalidade foi, em quaisquer das classes diamétricas, sempre superior a unidade. O estoque de mudas para se obter uma árvore, uma arvoreta e uma vara foi, respectivamente de 297, 160 e 48 mudas. O número de espécies e a abundância aumentaram no período, assim como a área basal e a biomassa.

The present paper aims at evaluating the forest dynamics - mainly that brought by natural regeneration -in a fragment of dense, terra firme tropical primary forest from 1998 through 1999, municipality of Peixe-Boi (PA). Three 1 ha permanent plots were marked off and every individual within having DBH ≥ 10 cm was registered. Individuals having DBH between 5 and 10cm were sampled out in an area of 6.000 m2, those having DBH between 2 and 5cm were sampled out in an area totaling 2.400 in2, and individuals having DBH under 2 cm were sampled in 240 m2. There are about 143.000 individuals ranging from seedlings to trees, of 337 species and 76 families. Mimosaceae was the family with higher diversity (44 species). Fourteen families occurred as an only species, including 7 families occurring also as an only individual. Considering the whole sample (that is, independently from diametric class) the egression of 56 species versus ingression of 68 was verified, producing a net gain of 12 species. The dynamics of species richeness in natural regeneration is remarkably intense, and the dynamics of abundance of natural regeneration, is more intense than that of floristic richeness. It was also observed that only one family left, while 14 other families entered, thus enriching biodiversity in almost 30%. The highest mortality verified was of Bauhinia cf. rutilans and Mabea aff speciosa (300 and 21 individuals). Rinorea negleta and Lecythis idatimon displayed the recruitment of 171 and 89 specimens. The recruitment/mortality rate was higher than one unit in all diametric classes. The proportion of seedlings needed to obtain a tree, a sapling and a stemlet is 297, 160 e 48 respectively. Richeness and abundance increased during the one year period, as did basal area and biomass.

Aplicou-se o Método dos Quadrantes em uma floresta densa sobre mina de arenito em Serra Norte, PA. Foram amostrados todos os indivíduos vivos ou mortos com DAP > 10 cm (um indivíduo por quadrante). Trinta e oito famílias, 85 gêneros e 110 espécies foram registrados nos 104 pontos (ou 416 indivíduos) amostrados. Sapotaceae (40,90), Leguminosae sensu latu (26,76) e Rutaceae (25,82) foram as famílias que apresentaram maior índice de valor de importância - VIF - (13,63%, 8,9% e 8,61% respectivamente). Erisma uncinatum Warm. (15,86) foi a espécie que apresentou maior índice de importância (IVI), as árvores mortas apresentaram o 2o. maior índice: 14,07. A densidade por área (DTA) calculada foi de 1065 indivíduos/ha. A área basal encontrada foi de 28,9057m² para os 416 indivíduos amostrados (74,0502 m²/ha). Tanto a densidade quanto a área basal por unidade de área (ha) estimadas foram consideradas muito altas para a região. A estrutura da vegetação foi também analisada: o diâmetro médio foi de 31,21 cm; as alturas médias do fuste, copa e total estimados foi de 12,4, 5,8 e 18,2 m, respectivamente. A vegetação do sub-bosque foi também descrita qualitativamente.

The Quadrant Method was applied in dense forest on a sandstone mine in Serra Pará State. , All living or dead individuals with DBH 10 cm were sampled (one > individual per quadrant). In 104 points (or 416 individuals) sampled, 38 families, 85 genera and 110 species were registered. The families presenting the highest importance value index (VIF) were Sapotaceae (40,90), Leguminosae sensu latu (26,76) and Rutaceae (25,82). Erisma uncinatum Warm, was the species presenting the highest importance value index (15,86); as a group, dead trees presented the second highest index (14,07). The calculated density was 1 065 individuals/ha. The basal area was 28.9057m² for the 416 sampled individuals, or 74.0502m²/ha. The estimated density as well as the basal area per unit area (ha) were considered extremely high for the region. The structure of the vegetation was also analyzed: the mean diameter was 31,21 cm; the mean heigths of trunks and crowns were 12,4 m and 5,8 m respectively, giving a mean total of 18,2 m. The understory vegetation was also described qualitatively.