Mineralogy of a red latosol under different management systems for twenty-four years

Atualmente, procuram-se sistemas de manejo que preservem ou melhorem as qualidades do solo, tanto mineralógicas como orgânicas, priorizando maior produtividade. Este trabalho teve como objetivo verificar qualitativamente, por meio das técnicas de fluorescência de raios X, difração de raios X e infravermelho com transformada de Fourier, os efeitos provocados pela utilização dos manejos: plantio convencional, preparo mínimo e plantio direto, por 24 anos, na mineralogia de um Latossolo Vermelho distrófico de Ponta Grossa, PR. Não foram observadas mudanças significativas na mineralogia do Latossolo estudado, por meio das técnicas utilizadas, quanto aos diferentes manejos durante os anos de sua aplicação. Pôde-se verificar, qualitativamente, a presença dos minerais gibbsita, caulinita, haloisita, montmorilonita, hematita, rutilo, anatásio, goethita e quartzo.The search for management systems that preserve or improve soil qualities, the mineralogical as well as the organic composition, with a view to higher yields, is becoming more and more intense. The objective this study was to qualitatively verify the mineralogical effects of different management types: conventional , minimum and no-tillage for 24 years on a Red Latosol in Ponta Grossa, PR, Brazil, by the following techniques: X-ray diffraction, X-ray fluorescence and Fourier transform infrared. No significant changes in the mineralogy of the Red Latosol were observed by the techniques applied, as a result of the different management types. It was however possible to qualitatively verify the presence of the following minerals: gibbsite, kaolinite, halloysite, montmorillonite, hematite, rutile, anatase, goethite and quartz

Synthesis and X-ray crystal structure of the [Ni(HDPE)2][NO3]2.2H2O.

Submitted by Oliveira Flávia ([email protected]) on 2015-02-13T14:19:45Z No. of bitstreams: 1 ARTIGO_SynthesisX-rayCrystal.pdf: 468451 bytes, checksum: eb8d8fb5c1823511c81be5dbfd4ac105 (MD5)Approved for entry into archive by Gracilene Carvalho ([email protected]) on 2015-02-19T12:19:02Z (GMT) No. of bitstreams: 1 ARTIGO_SynthesisX-rayCrystal.pdf: 468451 bytes, checksum: eb8d8fb5c1823511c81be5dbfd4ac105 (MD5)Made available in DSpace on 2015-02-19T12:19:03Z (GMT). No. of bitstreams: 1 ARTIGO_SynthesisX-rayCrystal.pdf: 468451 bytes, checksum: eb8d8fb5c1823511c81be5dbfd4ac105 (MD5) Previous issue date: 199

Epikatonic acid from Austroplenckia populnea : structure elucidation by nmr spectroscopy and x-ray crystallography.

From the chloroform extract of Austroplenckia populnea, epikatonic acid, friedelin, populnonic acid, abruslactone A, salaspermic acid and 22b-epi-maytenfolic acid were isolated. The structure and stereochemistry of epikatonic acid were established by two-dimensional NMR spectroscopic techniques (HMQC, HMBC and NOESY) and later confirmed by single crystal X-ray diffraction as 3b-hydroxyolean- 12-en-29-oic acid, which unambiguously established the configuration of the hydroxyl group at C-3 as 3b-OH and the carboxyl group at C-20 as 20a-COOH. The crystal structure shows two independent molecules in the asymmetric unit. The crystal packing is stabilized by four O?H? ? ?O intermolecular hydrogen bonds, which give rise to infinite double chains along the c axis