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Concretes present great potential to be used in many areas of civil construction. Their properties can be improved by substitution or addition of alternative materials to the Portland cement. The diatomite is a sedimentary material composed mainly by silica and amorphous impurities, presenting very fine particle size, high porosity, and low specific mass. Concrete was produced in a ratio of 1:1:2 (cement: sand: gravel) with the addition of diatomite at contents of 5% and 10% by cement weight and a water/cement ratio of 0.54. The physico-mechanical properties of the concretes were evaluated by tests of compressive strength and water absorption by immersion. Also, X-ray diffraction and scanning electron microscopy were carried out to analyze the main phases in the cement paste. The results indicated that the addition of diatomite in the concrete increased the compressive strength due to the silica content in the material and reduced slightly the porosity.

Amazonian dark earths (ADEs) are fertile soils created by pre-Columbian Amerindian societies of the Amazon Basin. However, it is still not clear whether these soils were produced intentionally to improve infertile Amazonian upland soils or if they resulted from the accumulation of organic matter from sedentary settlements. This study characterizes the ADEs found in the naturally fertile alluvial floodplains of the Amazon River in the Central Brazilian Amazon according to total, exchangeable, and available contents of elements and organic carbon in soil profiles. ADEs contained higher levels of available elements and total P, Ca, Zn, and Cu. High total Cr, Ni, Co, and V content in these soils indicate that mafic minerals contributed to their composition, while higher contents of P, Zn, Ba, and Sr indicate anthropic enrichment. The presence of ADEs in floodplain areas strongly indicates non-intentional anthropic fertilization of the alluvial soils, which naturally contain levels of P, Ca, Zn, and Cu higher than those needed to cultivate common plants. The presence of archaeological sites in the floodplains also shows that pre-Columbian populations lived in these regions as well as on bluffs above the Amazon River. Resumo Terras Pretas de Índio (TPI) são solos com elevada fertilidade criados pelas sociedades ameríndias pré-colombianas na bacia amazônica. Ainda não existe um consenso se esses solos foram formados intencionalmente para melhorar a fertilidade dos solos distróficos de terra firme da Amazônia ou se resultaram da acumulação de material orgânico em assentamentos sedentários. O objetivo desta pesquisa foi realizar uma caracterização pedogeoquímica de TPI localizadas em áreas de várzeas naturalmente férteis do rio Solimões na Amazônia Central brasileira. Foram analisados os teores totais, trocáveis e disponíveis de elementos e carbono nos solos. As TPI mostraram altos conteúdos trocáveis e disponíveis de P, Ca, Zn e Cu. Elevados conteúdos totais de Cr, Ni, Co e V indicam contribuição de minerais máficos na gênese dos solos, enquanto que teores elevados de P, Zn, Ba e Sr nas TPI indicam enriquecimento antrópico. A ocorrência de TPI em áreas de várzea é uma forte evidência da fertilização não intencional dos solos de várzea, os quais, em condições naturais, apresentam teores de P, Ca, Zn e Cu acima dos níveis críticos para muitas culturas. A presença de sítios arqueológicos em áreas de várzea mostra que as populações pré-colombianas habitaram as várzeas e os interflúvios do rio Solimões.

Amazonian rainforests once thought to hold an innate pristine wilderness, are increasingly known to have been densely inhabited by populations showing a diverse and complex cultural background prior to European arrival. To what extent these societies impacted their landscape is unclear. Amazonian Dark Earths (ADEs) are fertile soils found throughout the Amazon Basin, created by pre-Columbian societies as a result of more sedentary habits. Much is known of the chemistry of these soils, yet their zoology, have been neglected. Hence, we characterised soil macroinvertebrate communities and activity in these soils at nine archaeological sites in three Amazonian regions. We found 667 morphospecies and a tenacious pre-Columbian footprint, with 43% of species found exclusively in ADEs. The soil biological activity is higher in the ADEs when compared to adjacent reference soils, and it is associated with higher biomass and richness of organisms known to engineer the ecosystem. We show that these habits have a unique pool of species, however, the contemporary land-use in ADEs drives nutrient decay and threats biodiversity. These findings support the idea that Humans have built and sustained a contrasting high fertile system that persisted until our days and irreversibly altered the biodiversity patterns in Amazonia.

The role of earthworms as one of the most important groups of ecosystem engineers in human-modified and natural environments has been increasingly recognized only during the last 30 years, yet earthworms and humans have been acting together in building landscapes for millennia. This relationship is well represented in the pre-Columbian raised fields, in flood-prone savannas around the rim of Amazonia, but also by the potentially significant role of earthworms in the formation and resilience of Amazonian Dark Earths. Through the bioturbating action of earthworms, soil is biologically, chemically, and physically altered; nutrients are translocated; organic matter is decomposed and transformed; and the surrounding biota interacts as a large orchestra where the soil musicians play together on the various instruments but where earthworms take a leading role, enhancing microbial activity and generally stimulating plant growth. In this article, we assess the remarkable role of earthworms at the center of soil pedogenetic processes within anthropogenic landscapes, dissecting their functions with a special focus on Amazonian Dark Earths.

A contribuição do setor ceramista relativa aos bens produzidos nacionalmente reflete a informalidade vigente nas olarias associada ao desconhecimento, em sua maioria, daqueles que manufaturam os produtos. Na região do nordeste, mais especificamente na Paraíba, a indústria de cerâmica vermelha também vivencia tal problemática associada à falta de um protocolo mais efetivo. Desse modo, este projeto foi desenvolvido visando contribuir para reduzir os impactos ambientais originados pela olaria Santa Cecília Ltda., PB, Brasil avaliando-se nova formulação com reaproveitamento do descarte, chamote. A caracterização dos materiais foi realizada por difração de raios X, por fluorescência de raios X por energia dispersiva, por microscopias, óptica e eletrônica de varredura. Os sistemas, chamote/amostras, queimados a 800, 900 e 1000 ºC foram também avaliados quanto às características cerâmicas.

Large areas of Plinthosols with ferruginous materials such as plinthite and/or petroplinthite are fairly common in the Brazilian Amazon basin. This work was carried out to investigate the chemical behavior, mineralogical composition and weathering stage of four representative soil profiles with plinthite and petroplinthite, in Iranduba, AM (Central Amazon). Three well-drained soil profiles at high elevations were studied (P1, Plinthic Vetic Ferralsol; P2 and P3, Vetic Endopetric Plinthosol) and a contrasting poorly drained soil (P4 Haplic Plinthosol), located at low elevation. After profile descriptions, soil samples were collected from each horizon, air-dried, sieved (2 mm), and analyzed for particle-size distribution, pH, exchangeable cations (Al3+, Ca2+, Mg2+, K+, and Na+), as well as available P and total organic carbon (TOC) content. The minerals present in the clay and sand fractions, as well as in the ferruginous materials were identified by X-ray Diffraction (XRD). The weathering stage of these soils was assessed by means of Ki and Kr indexes, and the amounts of free and amorphous Fe and Al oxides by using dithionite citrate bicarbonate (DBC) and ammonium oxalate dissolution procedures, respectively. The results showed that all soils were extremely unfertile, with pH levels ranging between strong and moderate acidity, very low sum of bases and organic matter content, and of available P. The mineralogy of the soil profiles was very similar, mainly of the well-drained soils, with predominance of kaolinite and quartz in the clay and sand fractions, respectively. In the poorly-drained P4, 2:1 clay particles were also observed. These profiles can be considered highly developed according to the Ki index, however, the Ki value of P4 was higher, indicating that this soil was less developed than the others. In summary, these profiles with plinthite and petroplinthite can be characterized as highly developed and infertile soils and are, with exception of P4, well-drained. Expressivas áreas de solos com presença de materiais ferruginosos como plintita e, ou, petroplintita são muito frequentes na Bacia Amazônica brasileira. O objetivo deste trabalho foi avaliar os atributos químicos, a composição mineralógica e o grau de intemperismo de quatro perfis de solos com presença de plintita e petroplintita, em Iranduba, AM. Três perfis de solos, como P1, Latossolo Amarelo distrófico petroplíntico; e P2 e P3, Plintossolo Pétrico concrecionário típico, ocupam posição mais elevada na paisagem apresentando boa drenagem, enquanto o perfil P4, Plintossolo Háplico alítico típico, encontra-se na área mais baixa com restrições de drenagem. Após a descrição morfológica dos perfis, amostras dos seus horizontes foram coletadas, secas ao ar, preparadas para obtenção da terra fina seca ao ar (TFSA) e posteriormente submetidas às análises químicas e mineralógicas, por meio de difratometria de raios-X (DRX) e ataque sulfúrico. As análises químicas revelaram que todos os solos apresentavam fertilidade extremamente baixa, com pH variando entre forte e moderadamente ácido, teores elevados de Al3+ no complexo trocável, baixos valores de soma de bases, matéria orgânica e P disponível. A mineralogia revelou similaridade entre os perfis, principalmente entre os bem-drenados, com predomínio de caulinita e quartzo nas frações argila e areia, respectivamente. No perfil com deficiência de drenagem (P4), a fração argila apresentou também mineral do tipo 2:1. Os índices Ki e Kr revelaram que os perfis bem-drenados P1, P2 e P3 são altamente desenvolvidos e quimicamente intemperizados, enquanto o P4 foi caracterizado como menos desenvolvido, quando comparado aos demais estudados. Por fim, os perfis com presença de plintita e petroplintita na região de estudo são altamente desenvolvidos e possuem fertilidade do solo extremamente baixa; com exceção do perfil P4, os solos são bem-drenados.

The stability of soil organic matter (OM) in Amazonian anthropogenic soils, Terra Preta de Índio (TPI), is still not completely understood. The large contribution from black carbon (BC) and minerals to these soils is well-known; OM stability is therefore frequently explained by these properties, providing intrinsic recalcitrance (BC) and chemical protection against decomposition (OM-mineral associations), but the relative importance of both mechanisms that underlie the stability are not yet understood. In order to better understand the sources and decay processes of soil OM in these soils, we studied the molecular composition using pyrolysis gas-chromatography/mass-spectrometry. To this end, several soil OM fractions of samples from two TPI soils and an adjacent Xanthic Acrisol that served as a reference soil (REF) were studied (0–2 m depth). A sequential fractionation was applied in order to better understand the composition of soil OM pools with different association to the soil matrix. The studied soil OM fractions included the free light fraction (FLF; i.e., charcoal and litter), the occluded light fraction (OLF; charcoal and litter within aggregates), 0.1 M NaOH extractable OM (EX; comparable with the combined humic acid and fulvic acid fractions), and the remaining residue (RES; treated with HF/HCl; comparable with the humin fraction). The largest contribution to the total soil OM was found for EX and/or RES, the sum of which varied between 79% and 98% (Ave. 90.8%, n = 18). The minor contribution from the OLF (Ave. 4.4%) indicates that stabilisation within aggregates was not a major factor that contributed to OM stability in the studied profiles. Differences in molecular composition between the fractions were larger than those between profiles or with depth. The EX fraction showed the lowest contribution from plant (lignin phenols) and BC (PAHs, indenes, aromatics) derived products. The RES fraction showed a significantly larger contribution from BC related pyrolysis products compared to the EX. This non-extractable BC that is present in the RES after removal of the light fractions may reflect preferential binding of PAHs to minerals or, alternatively, the presence of highly condensed macromolecular polyaromatic structures. Changes with depth within the EX and RES fractions showed a larger contribution from products derived from BC in the anthropogenic horizons. Furthermore, the OM composition in EX and RES indicated that the degree of degradation of OM in anthropogenic horizons was relatively low. Apart from these similarities for anthropogenic horizons, the chemical composition of soil OM also showed large differences between both TPI soils. TPI-1 showed large variation between horizons while TPI-2 showed only minor changes with depth; this may be related to different phases of human occupation with time and/or a different soil usage.

Anthrosols known as Amazonian Dark Earth (ADE) have borne witness to the intensification of sedentary patterns and the demographic increase in Central Amazon. As a result, a recurring pattern has been observed of mounds with ADE arising from domestic activities and the disposal of waste. The objective of this research was to demonstrate the relationship of these anthropic activities with pedogenetic formation processes of ADE in the municipality of Iranduba, Brazil. Disturbed and undisturbed soil samples were taken from two areas of ADE (pretic horizon) and from a non-anthropic pedon. Physical, chemical, micromorphological and SEM-EDS analyses were performed. The coarse material of the pretic horizons consisted predominantly of quartz, iron nodules, ceramics and charcoal fragments, and the fine material is organo-mineral. There was a direct relationship between the color of pretic horizons and the number of charcoal fragments. The thickness of the ADE results from the redistribution of charcoal at depth through bioturbation, transforming subsurface horizons into anthropic horizons. ADE presents granular microaggregates of geochemical and zoogenetic origin. Degradation of iron nodules is intensified in pretic horizons, promoting a reverse pedogenic process contributing to the xanthization process. Surprisingly the anthropic activities also favor clay dispersion and argilluviation; clay coatings on the ceramic fragments and in the pores demonstrate that this is a current process. Processes identified as contributing to ADE genesis included: i) addition of organic residues and ceramic artifacts (cumulization) with the use of fire; ii) mechanical action of humans, roots and macrofauna (bioturbation); iii) melanization of deeper horizons as a result of bioturbation; iv) argilluviation and degradation of iron nodules. This study offers new support to archaeological research in respect to ADE formation processes in Central Amazon and confirmed the hypothesis that ancient anthropic activities may trigger and/or accelerate pedogenetic processes previously credited only to natural causes.

Este trabalho tem por objetivo a caracterização física e mineralógica de argilas utilizadas industrialmente para a produção de blocos cerâmicos. As argilas foram caracterizadas por meio da determinação de distribuição granulométrica, limites de Atterberg e composição química, difração de raios X, e análise térmica diferencial e gravimétrica. Foram conformados corpos de prova por extrusão. Os corpos foram queimados a 800, 900 e 1000 ºC e em seguida determinou-se absorção de água e módulo de ruptura à flexão. Também foram determinadas a absorção de água e a resistência à compressão simples de blocos cerâmicos comerciais produzidos com as amostras analisadas. Pode-se observar que as amostras apresentam limites de plasticidade dentro da faixa indicada para cerâmica vermelha e que são constituídas basicamente por caulinita, quartzo, mica e feldspatos, com algumas amostras apresentando goetita e hidróxido sílico-aluminoso. Concluiu-se também que a caracterização permite estimar as argilas adequadas ou não para a produção de blocos cerâmicos.

A indústria oleira nacional possui uma grande importância econômica e social, movimentando bilhões de reais e empregando milhões de pessoas. No entanto, apresenta uma grande defasagem tecnológica, o que se reflete na produção de peças de baixa qualidade e em uma grande quantidade de perdas na produção. Assim, visando melhorar a qualidade dos blocos cerâmicos esse trabalho tem por objetivo analisar a influência de aditivos no comportamento de plasticidade de massas para produção de blocos cerâmicos e nas propriedades físicas dos corpos produzidos com as massas aditivadas. Foram utilizados cinco massas industriais e dez aditivos durante o estudo. Foi analisada a influência dos aditivos nos limites de Atterberg das massas e selecionados os aditivos que reduziam os limites de plasticidade. Foram preparadas formulações com os aditivos selecionados e conformados corpos de prova por extrusão. Determinou-se o módulo de ruptura à flexão após secagem e queima e a absorção de água após queima desses corpos de prova. Com base nos resultados pode-se concluir que alguns aditivos reduzem o limite de plasticidade das massas e melhoram significativamente o comportamento mecânico após secagem e após queima.

As várzeas do rio Solimões são áreas inundáveis com predomínio de Gleissolos, onde se estabeleceu grande parte da população rural do Estado do Amazonas. Os objetivos deste trabalho foram caracterizar e classificar cinco perfis de Gleissolos, distribuídos em três áreas da bacia do Médio Amazonas, localizados nas várzeas dos municípios de Manacapuru e Iranduba. Após a descrição morfológica dos solos, coletaram-se amostras dos seus horizontes para caracterização física, química e mineralógica. Similarmente, todos os perfis apresentaram expressiva gleização na matriz do solo, com cores cinzenta a cinzenta-esverdeada, nos horizontes mais superficiais, e cinzenta-clara a cinzenta-escura, nos subsuperficiais, denotando a redução do ferro. Os teores mais elevados da fração areia em horizontes de subsuperfície indicaram presença de diferentes camadas de deposição fluvial, enquanto os elevados teores de silte evidenciaram a natureza sedimentar recente e o baixo grau de desenvolvimento pedogenético desses solos. Os cátions predominantes nos solos foram Ca2+ e Mg2+, que apresentaram porcentagens de sódio trocável (PST), com amplitude de variação entre 0,70 e 2,09. Os valores de carbono orgânico encontrados foram menores de 80 g kg-1, apresentando a natureza mineral dos sedimentos recém-depositados. A composição mineralógica da fração argila revelou presença significativa de argilominerais 2:1, mas sem grande variabilidade entre os perfis. Esses resultados refletiram-se em elevada soma e saturação por bases, caracterizando solos eutróficos e com argila de atividade alta. Made available in DSpace on 2021-10-09T02:18:07Z (GMT). No. of bitstreams: 1 V37N2a03.pdf: 1121963 bytes, checksum: df6d82aa596d0b589d2c5cdde8785990 (MD5) Previous issue date: 2013

The aim of this study was to understand how a stream ecosystem that flows from its fountainhead to its mouth inside a city, changes from a water resource to a point pollution source. A multidisciplinary descriptive approach was adopted, including the short-term temporal and spatial determination of physical, chemical, biological and ecotoxicological variables. Results showed that water quality rapidly decreases with increasing urbanization, leading the system to acquire raw sewage attributes even in the first hundred meters after the fountainheads. Despite the tidal circulation near the stream mouth being restricted by shallowness, some improvement of the water quality was detected in this area. The multidisciplinary evaluation showed to be useful for obtaining a more realistic understanding of the stream degradation process, and to forecast restoration and mitigation measures.

The biospeckle (BSL) is based on the incidence of laser light upon active biological materials, followed by analysis and manipulation of secondary images, and then, application to those images of a second-order statistics technique called the inertial moment (IM) that results in information about the activity of the specimen. This technique was previously used to analyze sperm motility. A bull’s fertility could be evaluated by several semen parameters in vitro and more precisely by conception rates of AI heifers. The objective of this work was to evaluate the fertility of bull’s frozen semen showing different levels of activity in an AI program. Semen of 6 mature IA donor bulls (Bos taurus indicus) was previously divided in 2 groups (group I: motility ≥50%; group II: motility

Sperm motility decreasing in a semen sample over time is an indirect approach to assess spermatozoa viability and should be related to the ejaculate fertility. The biospeckle (BSL) is an interacting phenomenon between laser light and biological specimens that allows measurement of sperm kinetic activity by means of an index called the inertial moment (IM). The aim of this work was to evaluate sperm motility diminishing in frozen bovine semen with BSL and analyze semen fertility in relation to the motility decreasing behavior patterns showed by different semen samples. Fertility was assessed by beef heifer conception rates after AI. Semen of 6 mature IA donor bulls (Bos taurus indicus) was previously divided in 2 groups (group I: motility ≥50%; group II: motility 0.05), but a tendency to differ was observed when a greater number of illuminations was done. Our data suggest that the BSL was capable of identifying spermatozoa surviving between high and low motility groups, and the sperm motility decreasing measured by the IM might be an objective approach to evaluate semen fertilization potential. Financial support: FAPEMIG, grant EDT 94/07, CNPq.

Sperm motility is a physical parameter evaluated in semen samples of the bull and is thought to be related to the fertility in the male. Despite being a characteristic of simple and fast evaluation, motility estimates involve subjective components when analyzed by light microscopy (LM) that might restrain their evaluation in some conditions. Moreover, in some species, poor correlations were observed between spermatozoa motility and semen fertility. The incidence of coherent light in a semen sample generates a phenomenon called biospeckle (BSL) that is capable of measuring the kinetics activity of the spermatozoa. In this work the relationship among sperm kinetics variables evaluated by LM and BSL and conception rates in beef heifers was investigated, with the purpose to predict frozen semen fertility when laser light is used. Sixty semen samples of 6 mature AI donor bulls (Bos taurus indicus) herein named A, B, C, D, E, and F were thawed at 37°C for 30 s in a water bath and evaluated by LM and BSL. In LM evaluation, an index (IND) was proposed to group together, in a single mean estimate, the spermatozoa motility (M: % scale) and velocity (V: 1 to 5 scale) according to the equation IND = [V × 20 + M]/2. In the BSL evaluation, each sample was illuminated (n = 10 per bull) by a laser beam (He-Ne, 632 nm and 10 MW) for 40 s and a mean inertial moment (IM) was obtained for each donor bull. These semen samples were used in an AI program of beef heifers (n = 166) clinically examined for reproductive health, body condition, and weight. Pregnancy diagnosis was done by ultrasound images (Falco 100, 6 MHz, Pie Medical, Crawley, UK) 28 days after insemination. Fertility estimates were done by the generalized linear model using logistic regression (stepwise methodology), generating an equation to predict the conception rate of the semen, the variables of which were IM and IND. Results of the predicted conception rates (pCR) using IM and IND and the observed conception rates (oCR) were A (0.5490; 0.57), B (0.6483; 0.68), C (0.7108; 0.71), D (0.4552; 0.28), E (0.4797; 0.54), F (0.3825; 0.47), respectively. Positive correlations (P < 0.05) were observed between pCR and oCR (r = 0.79) showing a similar behavior between in vitro and in vivo estimates. Results of this work showed that there is a high correlation between spermatozoa kinetics and semen fertility in the bull and that BSL motility analysis could be used as an approach to evaluate the fertility of semen samples. Financial support: FAPEMIG grant EDT 94/07, CNPq.

The Itajai-Acu and Camboriu rivers are the main important water suppliers for domestic and agroindustrial use in Itajai and Balneario Camboriu cities in southeastern coast of Brazil. The waste dispoasal by human activities in these estuaries may result in poor water quality and even prevent its use for these activities. In order to evaluate the effects of the human activities upon the estuaries water quality, this study was carried out to evaluate and compare the surface water quality in both estuaries, using a toxicological bioassay to mesure the effect of these waters in growth of marine microalgae Skeletonema costatum (Bacillariophyceae). The samples were colletcted from august of 2003 to march of 2004 in every two weeks at CEPSUL/IBAMA pier (in Itajai-Acu estuary) and turistic pier (in Camboriu estuary). The physical and chemical characteristics of the samples were determined in situ. The samples were taken to laboratory and frozen for further use. After conducing the bioassay, the results show an increase in algal growth due to excess of nutrients in the samples of both estuaries. This result indicates water eutrophication, as reported in other studies. No effect in the growth of the species was observed for the samples collected in summer months. The samples of march of 2004 from Camboriu estuary were toxic to S. costatum. This result may be due to the disposal of treated wastewater from Balneario Camboriu wastewater treatment plant in the surface river water. The observed concentration effect (CEO) obtained for the samples of march were almost 50%. The CE50 calculated was 96,17% for one sample of march. In the present work, the use of microalgae toxicity test for mesure toxicity in environmental samples and its use as water eutrophication indicator were confirmed.