Organic geochemistry of ODP Sites 128-798 and 128-799

Miocene to Quaternary sediments from the Oki Ridge (Site 798) and the Kita-Yamato Trough (Site 799) in the Japan Sea contain organic carbon ranging from about 0.6% in light-colored layers to almost 6% in dark layers. The organic matter consists of a variable mixture of marine and terrigenous contributions, the ratio of which is not correlated to the total organic carbon content. Marine organic particles clearly dominate in the deeper section of Hole 799B. The extractable bitumen is strongly dominated by long-chain alkenones from microalgae in the shallower sediments, whereas bishomohopanoic acid (C32) of eubacterial origin is the single most abundant compound in deeper samples. Normal alkanes and straight-chain carboxylic acids, both of which show a bimodal distribution with odd and even carbon-number predominance, respectively, are two other groups of compounds which are important constituents of the extracts. The deepest samples at Site 799 contain a considerable amount of short-chain components, which probably migrated upward from thermally more altered deeper sediments.

Geothermal measurements at ODP Leg 127 and 128 sites

Downhole temperature and thermal conductivity measurements in core samples recovered during Legs 127 and 128 in the Japan Sea resulted in five accurate determinations of heat flow through the seafloor and accurate estimates of temperature vs. depth over the drilled sections. The heat flows measured at these sites are in excellent agreement with nearby seafloor measurements. Drilling sampled basaltic rocks that form the acoustic basement in the Yamato and Japan basins and provided biostratigraphic and isotopic estimates of the age of these basins. The preliminary age estimates are compared with predicted heat flow values for two different thermal models of the lithosphere. A heat flow determination from the crest of the Okushiri Ridge yielded an anomalously high heat flow of 156 mW/m**2. This excessive heat flow value may have resulted from frictional heating on an active reverse fault that bounds the eastern side of the Ridge. Accurate estimates of sedimentation rates and temperatures in the sedimentary section combined with models of basin formation provide an opportunity to test thermochemical models of silica diagenesis. The current location of the opal-A/opal CT transition in the sedimentary section is determined primarily by the thermal history of the layer in which the transition is now found. Comparison of the ages and temperatures of the layer where the opal-A/opal-CT is found today is compatible with an activation energy of 14 to 17 kcal/mole.

Investigar con estudio de caso la dirección escolar. Un libro escrito por Rosa Vázquez Recio : Reseña de: Rosa Vázquez Recio (2011). Investigar la dirección escolar con estudio de caso: relato de una experiencia. Archidona: Aljibe, 128 pp.

Reseña sobre el libro Investigar con estudio de caso la dirección escolar escrito por Rosa Vázquez Recio, doctora y profesora titular de Didáctica y Organización escolar de la Universidad de Cádiz, sobre la realización de un estudio de caso acerca de la dirección escolar. La autora comparte sus temores y progresos, los dilemas y aciertos durante la realización de este estudio de caso a pie de escuela. Conocer su experiencia a través de este libro puede ayudar a quienes se inician en la tarea de la realización de estudios de caso o investigación sobre la dirección escolar así como a investigadores e investigadoras en general.

Diana Bellesi, El jardín. Rosario, Bajo la luna nueva, 1994, 2da. Ed., 128 páginas

Fil: Mallol, Anahí Diana. Universidad Nacional de La Plata. Facultad de Humanidades y Ciencias de la Educación; Argentina.

Mössbauer characterisation of sediments from ODP Sites 128-798 and 128-799

57Fe Mössbauer spectra for 26 sediment and 6 carbonate concretion samples from Sites 798 and 799 were recorded at 293 K. Most spectra were deconvolved to two quadrupole doublets without magnetic hyperfine structure. Typical Mössbauer parameters were: isomer shift (I.S.) = 0.34 mm/s and quadrupole splitting (Q.S.) = 0.64 mm/s for the paramagnetic Fe3+ component (partly, pyrite); I.S. = 1.13 mm/s and Q.S. = 2.64 mm/s for the high-spin Fe2+ component derived from iron-bearing aluminosilicates. A few spectra included other high-spin Fe2+ components ascribed to iron-bearing carbonate minerals (e.g., ferroan magnesite), according to the Mössbauer parameters for Fe2+ in the carbonate concretions. We present the distribution of iron among different chemical forms as a function of depth. These data might indicate changes of depositional and diagenetic conditions.

Diana Bellesi, El jardín. Rosario, Bajo la luna nueva, 1994, 2da. Ed., 128 páginas

Fil: Mallol, Anahí Diana. Universidad Nacional de La Plata. Facultad de Humanidades y Ciencias de la Educación; Argentina.

Investigar con estudio de caso la dirección escolar. Un libro escrito por Rosa Vázquez Recio : Reseña de: Rosa Vázquez Recio (2011). Investigar la dirección escolar con estudio de caso: relato de una experiencia. Archidona: Aljibe, 128 pp.

Reseña sobre el libro Investigar con estudio de caso la dirección escolar escrito por Rosa Vázquez Recio, doctora y profesora titular de Didáctica y Organización escolar de la Universidad de Cádiz, sobre la realización de un estudio de caso acerca de la dirección escolar. La autora comparte sus temores y progresos, los dilemas y aciertos durante la realización de este estudio de caso a pie de escuela. Conocer su experiencia a través de este libro puede ayudar a quienes se inician en la tarea de la realización de estudios de caso o investigación sobre la dirección escolar así como a investigadores e investigadoras en general.