Biogeochemical Processes
Mostrando 13-24 de 35 artigos, teses e dissertações.
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13. Argilominerais em solos de manguezais da costa brasileira / Clay minerals in mangrove soils of Brazilian coast
Mangroves are transitional ecosytems between continental and marine environments. Its widely distributed along Brazilian coast under great variability of climatic, oceanographic, geological and geomorphological conditions. Its soil mineralogy has a relevant role in the pedogenic processes and biogeochemical behavior of nutrients and potential inorganic and o
Publicado em: 2010
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14. Estudo do fósforo sedimentar e de suas especiações químicas em dois sistemas costeiros e Plataforma Continental Sudeste (Brasil) e Baía do Almirantado (região antártica) considerando suas relações biogeoquímicas / Study of phosphorus and its chemical speciation in sediments in two coastal environments and southeasterns continental shelf (Brazil) and admiralty Bay (Antarctic region) considering its biogeochemical aspects
This work aims to study the total and chemical species of phosphorus in the surface sediments associated to the biogeochemical processes in two estuarine systems, the southeastern continental shelf and Antarctic polar region. Bottom water samples were collected in two seasonal periods (summer-winter) in the estuaries under different degrees of environmental
Publicado em: 2008
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15. IMPLICAÇÕES LIMNO-ECOLÓGICAS DERIVADAS DA INFECÇÃO VIRAL NO PLÂNCTON
Virus are described as the most abundant and dynamic organisms in the aquatic environment, influencing communities composition and biogeochemical and ecological processes. These organisms are responsible for great part of the bacterial and phytoplanktonic mortality, for algal blooms decrease and for increasing the nutrients and carbon availability. Many prev
Publicado em: 2008
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16. Relationship amomg benthic communities and sedimentary organic matter: responses to the quality of food resources and influence on early diagenesis / Relações entre as comunidades bênticas e a matéria orgânica sedimentar: respostas à qualidade dos recursos alimentares e influência na diagênese recente
A qualidade da matéria orgânica e a magnitude de suas deposições estão entre os principais fatores que controlam as respostas dos organismos bênticos marinhos. Uma vez depositada nos sedimentos, a matéria orgânica é degradada por processos biogeoquímicos microbianos, que podem ser acelerados mediante a bioturbação da macrofauna. Entretanto, em re
Publicado em: 2008
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17. Metaproteomic and biochemistry hydrocarbons and heavy metals-contaminated soils / Metaproteomica e bioquimica de solos contaminados por hidrocarbonetos e metais pesados
Hydrocarbons, heavy metals and agricultural defensives are high risk pollutants to human health. These pollutants are constantly introduced into the environment as a result of petrochemical, industrial, agricultural activities and our modern life style, requiring remediation processes that are used to their complete elimination. Bioremediation is a process c
Publicado em: 2008
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18. Distribuição de mercúrio em diferentes solos da Bacia do médio Rio Negro-AM: influência da matéria orgânica no ciclo biogeoquímico do mercúrio
Soils play an important role in the biogeochemical cycle of mercury as a sink for and source of this metallic species to atmospheric and hydrological compartments. In the study reported here, various types of soil were evaluated to ascertain the influence of parameters such as pH, organic matter content, Fe, Al, sand, silt, clay, C/H, C/N, C/O atomic ratios,
Química Nova. Publicado em: 2007-04
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19. Bacterial and Archaeal diversity in mangrove and marisma soils / Diversidade de Bacteria e Archaea em solos de mangue e marisma
The bacterial diversity in mangrove (Brazil) and marisma (Espanha) soils are largely unknown. Bacterial communities participate in biogeochemicals processes that occurs in soils of estuarine ecosystems. Determinations of the bacterial communities structures and diversity can occur in function of different physico-chemical conditions, reflecting in the biogeo
Publicado em: 2006
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20. Nitrogen balance in paired small catchments (forest vs. pasture) in Rondonia state. / Balanço de nitrogênio em microbacias pareadas (floresta vs. pastagem) no estado de Rondônia.
The nitrogen cycle has been altered by anthropogenic activities, in response to the increment of cultures such, as the leguminous, fossil fuel use, and deforestation for agricultural uses and cattle raising. In temperate regions, there is considerable information about the biogeochemical cycle of nitrogen and the role of anthropogenic alterations on this cyc
Publicado em: 2005
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21. "Methodology for determination of organic geochemistry biomarkers in sediment - Aliphatic hydrocarbons, PAHs, Sterols and Alkenones" / "Metodologia para determinação de biomarcadores geoquímicos orgânicos em sedimentos - Hidrocarbonetos Alifáticos e Aromáticos, Esteróis e Alquenonas"
The fate of most organic matter in the oceans is the marine sediment. This preserved organic matter became an unique reservoir of information about the operation of biogeochemical processes in the geological past, and how these processes responded to environmental changes. Some molecules are only synthesized by sea organisms, others only by higher plants. Th
Publicado em: 2003
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22. In situ monitoring and biogeochemical cycling of nutrients in estuarine waters
This thesis describes the use of in situ and laboratory techniques for monitoring nitrate, phosphate and master variables in the environment. Chapter One presents a general overview of nutrients, how they are essential for aquatic biota, their general characteristics and the importance of their behaviour in estuaries. Commonly used analytical methods for nut
Publicado em: 2002
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23. Discovery of a bacterium, with distinctive dioxygenase, that is responsible for in situ biodegradation in contaminated sediment
Microorganisms maintain the biosphere by catalyzing biogeochemical processes, including biodegradation of organic chemical pollutants. Yet seldom have the responsible agents and their respective genes been identified. Here we used field-based stable isotopic probing (SIP) to discover a group of bacteria responsible for in situ metabolism of an environmental
National Academy of Sciences.
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24. Anomalies in coral reef community metabolism and their potential importance in the reef CO2 source-sink debate
It is not certain whether coral reefs are sources of or sinks for atmospheric CO2. Air–sea exchange of CO2 over reefs has been measured directly and inferred from changes in the seawater carbonate equilibrium. Such measurements have provided conflicting results. We provide community metabolic data that indicate that large changes in CO2 concentration can o
The National Academy of Sciences.