|
|
|
| Registros recuperados: 10 | |
|
| |
|
| |
|
|
| Corbari, Laure; Zbinden, Magali; Cambon-bonavita, Marie-anne; Gaill, Françoise; Compere, Philippe. |
| The shrimp Rimicaris exoculata is considered a primary consumer that dominates the fauna of most Mid-Atlantic Ridge hydrothermal ecosystems. The shrimps harbour in their gill chamber an important ectosymbiotic community of chemoautotrophic bacteria associated with iron oxide deposits. The settlement and development of this ectosymbiosis was investigated using microscopy techniques (light microscopy, LM; and scanning, transmission and environmental scanning electron microscopy: SEM and ESEM, respectively) for shrimps from 2 different vent fields (Rainbow, 36 degrees 14.0' N and TAG, 26 degrees 08.0' N). The results revealed a bacterial re-colonisation after each exuviation and a development of the bacterial community in 5 steps in relation to the moult... |
| Tipo: Text |
Palavras-chave: Iron oxides; Ectosymbiosis; Moult cycle; Shrimp; Hydrothermal vents. |
| Ano: 2008 |
URL: http://archimer.ifremer.fr/doc/2008/publication-4626.pdf |
| |
|
|
| Silva,Alexandre Christófaro; Souza,Solange de; Fabris,José Domingos; Barbosa,Maurício Soares; Barral,Uidemar Morais; Costa,Roberto Vial. |
| ABSTRACT In the Southern Espinhaço Mountain Chain and in the Upper Jequitinhonha Valley, magnetic soils, in different pedogenetic stages, are found to be forming over intrusions of basic lithology. The essential chemical and mineralogical properties of samples from magnetic soil profiles from those two physiographic environments in the state of Minas Gerais, Brazil, are reported. Three of the pedons (Rhodic Kandiustox – RKox, Rhodic Haplustox – RHox, and Typic Argiustoll - TAoll) were identified as being indeed developed over basic rocks; the fourth pedon (Typic Haplustox - THox) is currently forming on an acidic rock. Particle size and routine chemical analyses were performed on samples from all horizons of the four selected soil profiles. For a deeper... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Iron oxides; X ray diffractometry; Mössbauer spectroscopy; Scanning electron microscopy; Energy dispersive spectroscopy. |
| Ano: 2017 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-06832017000100305 |
| |
|
|
| Ferreira,Celmo Aparecido; Silva,Alexandre Christófaro; Torrado,Pablo Vidal; Rocha,Welington Willian. |
| The Brazilian System of Soil Classification (SiBCS) is a taxonomic system, open and in permanent construction, as new knowledge on Brazilian soils is obtained. The objective of this study was to characterize the chemical, physical, morphological, micro-morphological and mineralogical properties of four pedons of Oxisols in a highland toposequence in the upper Jequitinhonha Valley, emphasizing aspects of their genesis, classification and landscape development. The pedons occupy the following slope positions: summit - Red Oxisol (LV), mid slope (upper third) - Yellow-Red Oxisol (LVA), lower slope (middle third)- Yellow Oxisol (LA) and bottom of the valley (lowest third) - "Gray Oxisol" ("LAC"). These pedons were described and sampled for characterization in... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Soil color; Iron oxides; Soil classification; Pale Oxisol. |
| Ano: 2010 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-06832010000100020 |
| |
|
|
| Batista,Marcelo Augusto; Costa,Antonio Carlos Saraiva da; Souza Junior,Ivan Granemann de; Bigham,Jerry Marshal. |
| Maghemite (g-Fe2O3) is the most usually found ferrimagnetic oxide in red basalt-derived soils. The variable degrees of ionic substitution of Fe3+ for different metals (e.g. Ti4+, Al3+, Mg2+, Zn2+, and Mn2+) and non-metals in the maghemite structure influence some cristallochemical features of this iron oxide. In this study, synthetic Zn-substituted maghemites were prepared by co-precipitation in alkaline aqueous media of FeSO4.7H2O with increasing amounts of ZnSO4.7H2O to obtain the following sequence of Fe3+ for Zn2+ substitutions: 0.0, 0.025, 0.05, 0.10, 0.15, 0.20, and 0.30 mol mol-1. The objective of this work was to evaluate the cristallochemical alterations of synthetic Zn-substituted maghemites. The dark black synthetic precipitated material was... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Iron oxides; X ray diffraction; Mass-specific magnetic susceptibility; Specific surface area; Isomorphic substitution. |
| Ano: 2008 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-06832008000200011 |
| |
|
| |
|
|
| Camargo,Livia Arantes; Marques Júnior,José; Pereira,Gener Tadeu. |
| A good knowledge of the spatial distribution of clay minerals in the landscape facilitates the understanding of the influence of relief on the content and crystallographic attributes of soil minerals such as goethite, hematite, kaolinite and gibbsite. This study aimed at describing the relationships between the mineral properties of the clay fraction and landscape shapes by determining the mineral properties of goethite, hematite, kaolinite and gibbsite, and assessing their dependence and spatial variability, in two slope curvatures. To this end, two 100 × 100 m grids were used to establish a total of 121 regularly spaced georeferenced sampling nodes 10 m apart. Samples were collected from the layer 0.0-0.2 m and analysed for iron oxides, and kaolinite and... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Iron oxides; Kaolinite; Gibbsite; Goethite; Hematite; Relief. |
| Ano: 2013 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-06832013000200001 |
| |
|
|
| Testoni,Samara Alves; Melo,Vander Freitas; Dawson,Lorna Anne; Salvador,Fábio Augusto da Silva; Kunii,Paulo Akira. |
| ABSTRACT Soil traces are useful as forensic evidence due to their potential to transfer and adhere to different types of surfaces on a range of objects or persons. Several works have been developed in forensic soils, under different analytical approaches. However, in Brazil, only the researches from the Group of the Federal University of Paraná have developed works with soils under a forensic approach. Focus has been given on the sequential chemical analyses and mineralogical techniques once they presented a large potential to discriminate soil samples, even that originated from the same bedrock. In this way, this work aimed to test a Standard Operating Procedure (SOP) for forensic soil sampling and an analytical protocol in Brazil between the academy and... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Forensic science; Soil evidence; Sequential chemical analysis; Gibbsite; Iron oxides. |
| Ano: 2019 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-06832019000100410 |
| |
|
| |
| Registros recuperados: 10 | |
|
|
|
