Lattice dynamics of noble metals on effective three-body interaction

Quite recently we modified the original model of Sarkar et al. for cubic metals in extending the ion-ion interaction, ion-electron interaction and the introduction of crystal equilibrium condition. We applied our scheme to alkali metals. We studied here the lattice dynamics of noble metals on our approach by calculating phonon dispersion relations along the three principal symmetry directions, [ξ00], [ξξ00] and [ξξξ] and the (θ-T) curves of three noble metals: copper, silver and gold. We obtained reasonable agreement with the experimental findings.

Borohidreto complexos de cobre (I) contendo difosfinas. Caracterização espectroscópica e comportamento térmico

Tetrahydroborate complexes of copper (I) with bidentate phosphines, [Cu(η 2-BH 4)(dppm)] (1), [Cu(η 2-BH 4)(dppe)] (2), [Cu(η 2-BH 4)(cis-dppet)] (3) and [Cu(η 2-BH 4)(dppb)] (4) (dppm = bis(diphenylphosphino)methane; dppe = 1,2-bis(diphenylphosphino) ethane; cis-dppet = 1,2-cis(diphenylphosphino)ethene; dppb = 1,4-bis(diphenylphosphino)butane) were prepared and characterized by elemental analysis, infrared spectroscopy, NMR and thermogravimetric analysis. The IR data for 1-4 showed bands typical of a bidentate coordination of BH 4 group to the copper atom and the 31P{ 1H} NMR spectra indicated that the phosphorous atoms are chelating the metal centre. The thermal behavior of the compounds was investigated and suggested that their thermal stability is influenced by the phosphines. Their thermal stability decreased as follows: [Cu(η 2-BH 4)(dppe)] (2) > [Cu(η 2-BH 4)(dppm)] (1) > [Cu(η 2-BH 4)(dppb)] (4) > [Cu(η 2-BH 4)(cis-dppet)] (3). According to thermal analysis and X-ray diffraction patterns all compounds decomposed giving Cu(BO 2) 2, CuO, CuO 2 and Cu as final products.

Method for the evaluation of insecticidal activity over time in Atta sexdens rubropilosa workers (Hymenoptera: Formicidae)

The active ingredients used in the formulation of toxic baits for leaf-cutting ants (Hymenoptera: Formicidae) should possess a delayed action defined as an insecticidal activity whereby worker mortality is ≤15% at 24 hours and ≥90% at 21 days. Serious shortcomings have occurred in the search for new active ingredients, such as the initial selection of fenoxycarb, copper oxychloride and diflubenzuron, compounds considered very promising but whose inefficiency was verified only later, indicating methodological problems. In view of this situation, we developed a classification method for insecticidal activity over time using workers of the leaf-cutting ant Atta sexdens rubropilosa Forel. The insecticides used were fipronil, sulfluramid GX071HB and sulfluramid GX439, vehicled in an attractive pasty formulation prepared based on citrus pulp. The results obtained were consistent from a toxicological viewpoint and agreed with the literature in terms of the control of colonies. Sulfluramids were found to possess a delayed action at a broad range of concentrations, in agreement with the fact that these substances are highly effective in the control of all leaf-cutting ant species. The smaller range of concentrations of fipronil with delayed action is probably related to its lower efficacy for species more difficult to control such as Atta capiguara (Forti et al. 2003). We discuss the importance of relating behavioral particularities to the specific feeding habits of leaf-cutting ants, with methodological adequacy of the assessment of insecticides aimed at toxic baits.

Four new metal complexes with the amino acid deoxyalliin

The solid complexes [Co(C6H10NO2S) 2], [Ni(C6H10NO2S)2], [Cu(C6H10NO2S)2] and [Fe(C 6H10NO2S)2] were obtained from the reaction of cobalt(II), nickel(II), copper(II) and iron(II) salts with the potassium salt of the amino acid deoxyalliin (S-allyl-L-cysteine). Electronic absorption spectra of the complexes are typical of octahedral structures. Infrared spectroscopy confirms the ligand coordination to the metal ions through (COO-) and (NH2) groups. EPR spectrum of the Cu(II) complex indicates a slight distortion of its octahedral symmetry. Mössbauer parameters permitted to identify the presence of iron(II) and iron(III) species in the same sample, both of octahedral geometry. Thermal decomposition of the complexes lead to the formation of CoO, NiO, CuO and Fe2O3 as final products. The compounds show poor solubility in water and in the common organic solvents. ©2005 Sociedade Brasileira de Química.

Processamento de nanomateriais em hidrotermal convencional e hidrotermal de microondas

Copper, zinc and nickel oxides present different properties in nanostructured form. These nanomaterials present very interesting morphologies such as urchin and flowers. This differents arquitechures can be employed in near future in several areas of applications as: nanocatalysis, nanooptoeletronic and nanomedicine.

Mapeamento de Paleosuperfícies associadas a identificação de depósitos supérgenos de cobre como ferramenta de exploração mineral na região de Itapeva e Ribeirão Branco- Vale do Ribeira, estado de São Paulo, Brasil

A few examples of supergene ore formation and their interaction with morphogenesis (palaeosurfaces) and weathering mineralogy are discussed. Geomorphological and mineralogical records to characterize palaeosurfaces associate the weathering of primary minerals and their relationship with concentrations of cooper and iron ore deposits in southeastern state of São Paulo, Brazil. We have distinguished two palaeosurfaces generated by several weathering phases and controlled by the geological framework. The first and oldest upper palaeosurfaces (900 - 1000 m a.s.l.), situated in Riberão Branco (Alto do Brancal), were developed on silico-limestones. It is formed by typical iron laterites enriched by secondary products of cooper. The second and younger level palaeosurfaces located in Itapeva (Santa Blandina and Bairro do Sambra). This palaeosurface is formed by copper percolating through the weathered rock (saprolite). Other features can be observed like neo-formed products in laterites. They are classified into two types: clay like silico- cupriferous products (with noticeable amounts of iron) and copper minerals (crysocolla, in their flat slopes). These features allowed the presence of copper ores and their morphogenesis control will help in the exploration and prospecting of supergene ore mineral.

Efeito de produtos químicos sobre a mancha bacteriana (xanthomonas perforans) e na ativação de proteínas relacionadas à patogênese em tomateiro

The present study aims to evaluate the effect of fungicides and antibiotics to control bacterial spot (Xanthomonas perforans) in tomato, and the activation of pathogenesis-related proteins. Hybrid tomato AP 529 was used to assess the severity of disease. The treatments consisted of spraying with acibenzolar-S-methyl, fluazinam, pyraclostrobin, pyraclostrobin + methiran, copper oxychloride, copper oxychloride and mancozeb + oxytetracycline, and inoculated and non-inoculated controls. After three days of treatment, all plants were inoculated with X. perforans (10 6 CFU / mL). Leaf discs were collected for assessment of peroxidase, polyphenol oxidase, β-1,3 glucanase, phenylalanine ammonia lyase and protease. The area under the disease progress curve (AUDPC) was calculated with the data of severity. All treatments had reduced AUDPC compared to the inoculated control. Fungicides acibenzolar-S-methyl, pyraclostrobin, and pyraclostrobin + methiran had more satisfactory results in reducing the severity of bacterial spot on tomato. The products based on pyraclostrobin together with acibenzolar-S-methyl induced enzymatic activities of peroxidase, polyphenoloxidase and β-1,3 glucanase, indicating that these products may be related to the induction of resistance to bacterial spot on tomato plants.

Alterações hidrogeomorfológicas devido à dinâmica de uso da terra na Bacia Hidrográfica do Ribeirão Santa Gertrudes (SP)

Agricultural and mining activities are directly related to changes in natural landscapes. From the perspective of anthropogenic geomorphology supported by general systems theory, this research has developed, in order to identify and analyze changes in the land use, mainly from agriculture and the exploitation of clay, and its implications in the hydro-geomorphological characteristics in the Santa Gertrudes Stream watershed (SP). This area is within the context of the Ceramic Pole Santa Gertrudes (SP), which besides its importance as a supplier of raw material, is characterized as the largest center of international reference in ceramic tiles on the American continent. For this purpose, we made land use and geomorphology maps of two scenarios, corresponding to the years 1962 and 2006, which allowed the identification of changes caused by human activities on the landforms of the area, such as the increase in area of parcels intended for mining activity, which went from 3.1% to occupy 19% of the catchment area of the respective period and that, among other changes, gave rise to new forms of relief as, for example, in levels of pit mining abrupt and smooth. The results indicate that the main features of representative of human changes in relief are represented for opening of large clay mining pits and agricultural activities, which intensified the denudation and sedimentation processes in the Santa Gertrudes Stream watershed.

Exportação de nutrientes em plantas de jambu, sob diferentes adubações

The jambu is a broad vegetable consumption in Northern Brazil, especially in Pará, known by the jambu and other common names is native to the Amazon region has been used and cultivated for culinary and also recently in natural medicines by their chemical properties, attributed to the spilanthol compound. Knowing the amount of nutrient uptake in plants, especially at the taken, it is important to evaluate the removal of nutrients necessary for economic fertilizer recommendations. So the goal of this project was to determine the accumulation of nutrients in plants of jambu (leaf and inflorescence) under different fertilizations. The experiment was conducted at São Manuel Experimental Farm UNESP. The statistical was arranged in the randomized block design, in a 2 x 6 factorial scheme, two sources of fertilizers (organic and mineral) and six doses of nitrogen, with four replications. We evaluated the macronutrients of accumulation N, P, K, Ca, Mg, S and micronutrients of accumulation B, Cu, Fe and Zn in leaves and inflorescence. The plants responded more jambu nutrients of translocation phosphorus (P), magnesium (Mg), sulfhur (S), boron (B), copper (Cu) and iron (Fe) in the inflorescences and phosphorus (P), calcium (Ca), manganese (Mg), sulfur (S), boron (B), copper (Cu) and iron (Fe) in leaves to organic fertilization demonstrating the effectiveness of using this source of fertilizer nutrients indicating that this was a defining characteristic in response to the accumulation of nutrients in the leaves and inflorescences jambu. Plants jambu are more responsive to fertilizer for the mineral of translocation nitrogen (N) and manganese (Mn) for both the sheet and for the inflorescences of plants jambu.

Concentrações de ferro, cobre, zinco e manganês em equinos da raça Puro-sangue Lusitano, antes e após exercício1

In order to evaluate the sera concentrations of iron, copper, zinc and manganese trace minerals in thirty Pure-bred Lusitano athlete horses before and after exercise certified by clinical and laboratory assessments were studied. Blood samples were taken before and after 20 minutes of a dairy trot and gallop slight training, perfomed in a sandy floor ring, to measure the mineral concentrations, by atomic absorption spectrophotometry. It was observed that after exercising, the serum activity of iron did not change (P=0.2365), whereas copper values have significantly risen after training (P<0.001). On the other hand, zinc and manganese trace minerals decreased after exercise (P<0.001). In conclusion, it is possible to consider that the short time exercise may trigger sweating and consequently to change the seru.

Retenção do cátion do sulfato de cobre nos compartimentos biótico e abiótico de mesocosmos com sistema de fluxo contínuo de água

Pós-graduação em Aquicultura - FCAV

Revisitação de Bromeliaceae na APA Santuário ecológico da Pedra Branca Caldas, MG

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Avaliação da chuva e banco de sementes em áreas de restinga, morfoecologia e potencial biótico de espécies ocorrentes nestes locais

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)