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| Registros recuperados: 603 | |
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| Costa,Marcondes Lima da; Kern,Dirse Clara; Pinto,Alice Helena Eleotério; Souza,Jorge Raimundo da Trindade. |
| This paper carried out a chemical investigation of archaeological ceramic artifacts found in archaeological sites with Black Earth (ABE) in the Lower Amazon Region at Cachoeira-Porteira, State of Pará, Brazil. The ceramic artifacts, mostly of daily use, belong to Konduri culture (from 900 to 400 years BP). They are constituted of SiO2, Al2O3, Fe2O3, Na2O and P2O5; SiO2 and Al2O3 together add up to 80 % and indicate influence of acid rocks, transformed into clay minerals basically kaolinite. The relative high contents of P2O5 (2.37 % in average) come out as (Al,Fe)-phosphate, an uncommon fact in primitive red ceramics, but found in some roman and egyptian archaeological sites. The contents of the trace elements are similar or below the Earth's crust... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Terra preta; Black earth; Lower Amazon; Soil; Chemistry; Phosphorus; Geochemical Evolution. |
| Ano: 2004 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0044-59672004000300004 |
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| FERNANDES, E.; BOOCK, A.; OLIVEIRA, A. R. de. |
| Em algumas regiões do Estado de Mato Grosso do Sul, a incidência da palmeira bacuri (Pradosia lutexens) diminui de forma acentuada a produtividade das pastagens, comumente formadas com os capins colonião e jaragua. A invasora tem preferência por solos de elevada fertilidade natural, principalmente, derivados de rochas calcárias, como ocorre na Região da Serra da Bodoquena ou, ainda, por áreas localizadas em vales intermontanos (furnas), cujos solos são de média a elevada profundidade. Foi conduzido um experimento com o objetivo de determinar a eficiência e o custo relativo de várias alternativas de controle da palmeira. A expectativa foi de que o emprego de métodos químicos (herbicidas a base de Picloran ou Dicamba + 2,4,5 T, ou óleo diesel) e mecânicos... |
| Tipo: Folhetos |
Palavras-chave: Control; Controle; Invasora; Mecânico; Mechanic; Palmeira; Palmeira Bacuri; Pasture; Pradosia lutexens; Bacuri; Pastagem; Químico; Chemistry. |
| Ano: 1986 |
URL: http://www.infoteca.cnptia.embrapa.br/infoteca/handle/doc/997494 |
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| Panfili, Jacques; De Pontual, Helene; Troadec, Herve; Wrigh, Peter J.. |
| Sclerochronology, the study of calcified structures to reconstruct the past history of living organisms, is central to fish biology and fisheries management. This manual aims to provide an overview of the current theoretical and practical aspects of sclerochronological studies. By providing information on the nature of calcified structures (otoliths, scales, skeleton), their uses in fish research and methods for preparation and examination, the manual constitutes a comprehensive guide for researchers, technicians and students either new to the field or interested in expanding their range of expertise. The enclosed multimedia version (DVD) is supplemented by videos illustrating the main technical procedures with an alternative navigation mode based on... |
| Tipo: Text |
Palavras-chave: Age; Age determination; Biological aging; Chemistry; Growth; Otolith reading; Otoliths; Scale reading; Scales; Skeleton. |
| Ano: 2002 |
URL: http://archimer.ifremer.fr/doc/00017/12801/9742.pdf |
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| We are pleased to welcome you to at the first Symposium on Metabolic organization in Brest, 19-22 April, 2009. This conference is being organized jointly by Ifremer (French Institute for the Research and Exploitation of the Sea), the Department of Theoretical Biology at Vrije Universiteit Amsterdam, the Universities of Brest (UBO), Marseille (LMGEM-UMR CNRS 6117), Caen (UMRPE2M, LBBM) and Lisbon (Instituto Superior Técnico), the IRD (French Research Institute for Development), the INRA (French National Institute for Agricultural Research), the NIOZ (RoyalNetherlands Institute for Sea Research), the IMARES Wageningen (Institute for Marine Resources and Ecosystem Studies), as all these research teams are involved in research on DEB theory. You are 81 persons... |
| Tipo: Text |
Palavras-chave: Ecology; Bivalve; Chemistry; Ecotoxicology; Physiology; Dynamic energy budget; Biology. |
| Ano: 2009 |
URL: http://archimer.ifremer.fr/doc/2009/acte-6790.pdf |
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| Bertrand, Guillaume; Celle-jeanton, Helene; Laj, Paolo; Rangognio, Jerome; Chazot, Gilles. |
| The present study investigates the chemical composition of wet atmospheric precipitation samples on a daily and an intra-event timescales in Opme, an experimental meteorological station located near Clermont-Ferrand, France. The samples have been collected from November 2005 to October 2007. A total of 217 rainwater samples, integrated for 24 h, were collected and analyzed for pH, conductivity, Na+, K+, Mg2+, NH4 (+) , Ca2+, Cl-, NO (3) (-) , SO (4) (2-) , PO (4) (3-) and HCO3 (-) . The composition of the rainwater collected appeared to be controlled by the following potential sources: neutralisation process (association among calcium, ammonium with nitrate and sulphate), marine and terrestrial sources. In order to determine the role of long-range... |
| Tipo: Text |
Palavras-chave: France; Chemistry; Air mass back trajectories; Sequential sampling; Major ions; Rainwater. |
| Ano: 2008 |
URL: http://archimer.ifremer.fr/doc/2008/publication-6390.pdf |
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| Maas, P.J.M.; Westra, L.Y.T.; Guerrero, S. Arias; Lobão, A.Q.; Scharf, U.; Zamora, N.A.; Erkens, R.H.J.. |
| A taxonomic revision of the genus Guatteria, including the former genera Guatteriella, Guatteriopsis and Heteropetalum is given. Within the genus Guatteria 177 species are recognized, 25 of which are new. Included are chapters on the history of the taxonomy of the genus, morphology, wood anatomy, karyology, palynology, chemistry, flower biology and pollination, dispersal, distribution and ecology, phylogeny and molecular studies, conservation, and uses. A synoptical key to all species is included, as well as two dichotomous keys, one for the species of Central America and Mexico, and one for the species of NE, E and SE Brazil. The species treatments include descriptions, full synonymy, geographical and ecological notes, vernacular names and taxonomic... |
| Tipo: Article / Letter to the editor |
Palavras-chave: Annonaceae; Chemistry; Descriptions; Flower biology and pollination; Guatteria; Guatteriella; Guatteriopsis; Heteropetalum; History; Molecular studies; Morphology; Neotropics; Palynology; Phylogeny; Taxonomy; Vernacular names. |
| Ano: 2015 |
URL: http://www.repository.naturalis.nl/record/588490 |
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| Deepika Bhalla; Siddhartha S. Mukhopadhyay. |
| Eutrophication is a threat to quality of surface and ground water bodies (SWB) and to bio-diversity of the aquatic eco-system. One of the causes of P accumulation in SWB is its excess application as a fertilizer on agricultural lands. Phosphorus buffering also contributes to eutrophication and remains a major problem years after the release of P is brought under control. It could be discerned from many experiments conducted world over that addition of small amount of P can remove excess P from soils, provided the solution P is maintained in such a manner that productivity is sustained, and nano-P could possibly play a role in it. In such endeavours, P must be applied to soils in amount exact to the requirement of crop. Of course ecological cautions of use... |
| Tipo: Presentation |
Palavras-chave: Chemistry; Ecology; Earth & Environment. |
| Ano: 2009 |
URL: http://precedings.nature.com/documents/3763/version/1 |
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| Kikuo Harigaya. |
| Nano-carbon materials are investigated intensively. In this paper, the edge-state in nanographene materials with zigzag edges is studied theoretically. In particular, while the inter-layer interactions are considered, we prove that edge states exist at the energy of the Dirac point in the doubly stacked nanographene, and in the case of the infinitely-wide lower layer case. This property applies both for the A-B and A-C stackings. |
| Tipo: Manuscript |
Palavras-chave: Chemistry. |
| Ano: 2009 |
URL: http://precedings.nature.com/documents/3878/version/1 |
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| Sierra Rayne; Kaya Forest. |
| Gas phase standard state (298.15 K, 1 atm) isomerization energies were calculated using the M062X functional with the QZVP, 6-311++G(d,p), 6-311++G(2d,2p), and cc-pVTZ basis sets against the 24 reactions in the ISOL set of benchmark isomerization energies for large organic molecules. The M062X functional appears to offer comparable isomerization energy prediction performance to the best performing currently available dispersion corrected functionals against this benchmark dataset. |
| Tipo: Manuscript |
Palavras-chave: Chemistry. |
| Ano: 2010 |
URL: http://precedings.nature.com/documents/5183/version/1 |
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| Jean-Claude Bradley; Philip Rosenthal; Rajarshi Guha; Khalid Mirza; Jiri Gut. |
| This talk was presented by Jean-Claude Bradley at the American Chemical Society meeting in Philadelphia on August 20, 2008. An introduction to Open Notebook Science is presented followed by an illustration of how ONS can be used in drug discovery. New data relating to the anti-malarial activity of Ugi products on 2 falcipain-2 docking sites is detailed. The docking calculations were provided by Rajarshi Guha and the enzyme and in vitro assays on Plasmodium falciparum were provided by Phil Rosenthal and Jiri Gut. Most of the syntheses were carried out by Khalid Mirza in the Bradley group.

Screencast available at:... |
| Tipo: Presentation |
Palavras-chave: Chemistry; Bioinformatics. |
| Ano: 2008 |
URL: http://precedings.nature.com/documents/2216/version/1 |
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| P Perumal. |
| Over the last few years, good quality freezable semen was not utilized effectively due to less knowledge about the freezability of semen. One reason is the lack of sufficient antioxidants in the seminal plasma and semen extender. The antioxidant content is reduced during the cryopreservation process and causes premature cryo-capacitation and modification of sperm membrane structure upon thawing. So the study of pre-freezing and post thaw seminal parameters like viability, motility, acrosomal integrity, lipid peroxide assay, vanguard distance traveled by sperm, mitochondrial membrane potential, velocity and motility parameters (CASA) and field fertility trial helped to assess the effectiveness of the additives. The conception rate was better in reduced... |
| Tipo: Manuscript |
Palavras-chave: Chemistry. |
| Ano: 2012 |
URL: http://precedings.nature.com/documents/6998/version/1 |
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| Registros recuperados: 603 | |
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