Los otros "setenta" : Un recorrido por la experiencia de la Tendencia Revolucionaria del Peronismo en la gobernación bonaerense (1973-1974)

En este artículo se analizará la participación y trayectoria de militantes de la Tendencia Revolucionaria del Peronismo en el Ministerio de Salud y Acción Social durante el gobierno provincial de Oscar Bidegain. Se indagarán las formas y sentidos que adoptó la práctica política de este particular actor dentro del ámbito institucional, junto a las tensiones que la misma desplegó tanto al interior del Movimiento Peronista como dentro del universo de la militancia revolucionaria ligada a MontonerosFil: Tocho, Fernanda. Universidad Nacional de La Plata. Facultad de Humanidades y Ciencias de la Educación. Instituto de Investigaciones en Humanidades y Ciencias Sociales (UNLP-CONICET); Argentina

El desafío institucional : La experiencia de la Tendencia Revolucionaria del Peronismo en el Ministerio de Asuntos Agrarios de la provincia de Buenos Aires (1973-1974)

Fil: Tocho, Fernanda. Universidad Nacional de La Plata. Facultad de Humanidades y Ciencias de la Educación. Instituto de Investigaciones en Humanidades y Ciencias Sociales (UNLP-CONICET); Argentina

El verano caliente del '74 : La Tendencia Revolucionaria del peronismo entre la asunción de Perón y el aniversario del 'triunfo popular'

Fil: Abbattista, María Lucía. Universidad Nacional de La Plata. Facultad de Humanidades y Ciencias de la Educación. Instituto de Investigaciones en Humanidades y Ciencias Sociales (UNLP-CONICET); Argentina.Fil: Tocho, Fernanda. Universidad Nacional de La Plata. Facultad de Humanidades y Ciencias de la Educación. Instituto de Investigaciones en Humanidades y Ciencias Sociales (UNLP-CONICET); Argentina

Size dependence of refractive index of goldnanoparticles

The extinction spectra of spherical gold nanoparticles suspended in a homogeneous media were measured and the results were adjusted with Mie's theory together with an appropriate modification of the optical properties of bulk material considering the limitation that introduces the size of nanoparticles on the dielectric function. Usually, the contribution of free electrons to the dielectric function is modified for particle size, while the contribution of bound electrons is assumed to be independent of size. This work discusses the separated contribution of free and bound electrons on the optical properties of particles and their variation with size for gold nanoparticles. The effects of dielectric function and its changes with size on extinction spectra near plasmon resonance are considered. The damping constant for free electrons was changed with size as usual and a scattering constant of C = 0.8 was used. For the bound electron contribution, two different models were analysed to fit the extinction spectra: on the one hand, the damping constant for interband transitions and the gap energy were used as fitting parameters and on the other, the electronic density of states in the conduction band was made size-dependent. For the first model, extinction spectra corresponding to particles with radius R = 0.7 nm were fitted using two sets of values of the energy gap and damping constant: $latex Eg = 2.3 eV \ and \ \gamma_{\mathrm {b}}=158~\mathrm {meV}/\hbar \ or \ Eg = 2.1 eV \ and \ \gamma_{\mathrm {b}}=200~\mathrm {meV}/ \hbar$. For the second model, a simple assumption for the electronic density of states and its contribution to the dielectric function in terms of size allowed to adjust extinction spectra for all samples explored (from 0.3 to 1.6 nm radius). This last model uses only one parameter, a scale factor R0 = 0.35 nm, that controls the contribution of the bound electrons in nanoparticles. Contrast between the maximum and the minimum in the extinction spectra near the resonance at 520 nm or alternatively the broadening of the plasmon band can be used to determine the size of gold nanoparticles with radius smaller than 2 nm

Lithospheric 3D gravity modelling using upper-mantle density constraints: Towards a characterization of the crustal configuration in the North Patagonian Massif area, Argentina

The North Patagonian Massif is an Argentinean plateau that has an average height of 1200 m and stands from 500 to 700 m above the neighboring areas. During Paleogene, it suffered a sudden uplift of more than 1200 m without noticeable internal deformation; thus, it could be related to isostatic disequilibrium. To shed light on the geodynamic development of the area it is necessary to characterize the present-day configuration of the crust. In this study, a lithospheric-scale 3D density model was developed by integrating all the available data of the area with the objective of assessing the depth of the crust–mantle discontinuity (Moho). During the construction of the initial density model, we tested different mantle density scenarios obtained using P- and S-wave velocities from tomographic models, converting them into densities and comparing the conversions with densities obtained from xenoliths. Below the North Patagonian Massif plateau, we have derived a Moho depth between 40 and 50 km which is from 2 to 7 km deeper than its surroundings. There is an evident correlation between high topography and deep Moho that would indicate isostatic equilibrium at present. The model results provide a new approach to the Moho depth in an area where there is no seismic constraining information about this discontinuity. In addition, we found a spatial correlation between the variation of the mean crustal density and the location of the Paleozoic terranes that were proposed to constitute the basement of Argentina.Fil: Gómez Dacal, María Laura. Universidad Nacional de La Plata. Facultad de Ciencias Astronómicas y Geofísicas. Departamento de Gravimetría; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Tocho, Claudia. Universidad Nacional de La Plata. Facultad de Ciencias Astronómicas y Geofísicas. Departamento de Gravimetría; Argentina. Comisión de Investigaciones Científicas de la Provincia de Buenos Aires; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Aragon, Eugenio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Investigaciones Geológicas. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. Centro de Investigaciones Geológicas; ArgentinaFil: Sippel, Judith. Universitat Potsdam; AlemaniaFil: Scheck Wenderoth, Magdalena. German Research Centre for Geosciences; AlemaniaFil: Ponce, Alexis Daniel. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Ciencias de la Tierra y Ambientales de La Pampa. Universidad Nacional de La Pampa. Facultad de Ciencias Exactas y Naturales. Instituto de Ciencias de la Tierra y Ambientales de La Pampa; Argentin

Analysis of Different Methodologies to Calculate Bouguer Gravity Anomalies in the Argentine Continental Margin

We have tested and used two methods to determine the Bouguer gravity anomaly in the area of the Argentine continental margin. The first method employs the relationship between the topography and gravity anomaly in the Fourier transform domain using Parker’s expression for different orders of expansion. The second method computes the complete Bouguer correction (Bullard A, B and C) with the Fortran code FA2BOUG2. The Bouguer slab correction (Bullard A), the curvature correction (Bullard B) and the terrain correction (Bullard C) are computed in several zones according to thedistances between the topography and the calculation point. In each zone, different approximations of the gravitationalattraction of rectangular or conic prisms are used according to the surrounding topography. Our calculations show that the anomaly generated by the fourth order in Parker’s expansion is actually compatible with the traditional Bouguer anomaly calculated with FA2BOUG, and that higher orders do not introduce significant changes. The comparison reveals that the difference between both methods in the Argentine continental margin has a quasi bimodal statistical distribution. The main disadvantage in using routines based on Parker's expansion is that an average value of the topography is needed for the calculation and, as the margin has an abrupt change of the topography in the continental slope area, it causes a bimodal distribution. It is worth noticing that, as expected, the most important differences between both methods are located over the continental slope both in complex structures such as part of the shared margin, as well as in isolated points where there are contributions from short wavelength or rugged topography.Fil: Pedraza de Marchi, Ana Carolina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de la Plata. Facultad de Ciencias Astronómicas y Geofísicas; ArgentinaFil: Ghidella, Marta E.. Ministerio de Relaciones Exteriores, Comercio Interno y Culto. Dirección Nacional del Antártico. Instituto Antártico Argentino; ArgentinaFil: Tocho, Claudia. Universidad Nacional de la Plata. Facultad de Ciencias Astronómicas y Geofísicas; Argentin

Picosecond phase-conjugate reflection from organic dye saturable absorbers

Phase conjugation with conversion efficiences of up to 50% has been obtained in DODCI and other saturable absorbers with picosecond pulses from a mode-locked dye laser. Reflectivity shows a quadratic dependence on pump intensity up to $latex \sim 500 \ MW cm-2

Adaptation of a tridimensional gravimetric model to the North Patagonian Massif area

El Macizo Norpatagónico es una altiplanicie que casi no presenta deformación rodeada de cuencas con distintos grados de deformación terciaria sobre las cuales sobresale entre 500 y 700 metros. Dicho macizo sufrió un levantamiento repentino de más de 1200 m en el Paleógeno, hipotéticamente, a causa de movimientos epirogénicos. Esta última afirmación se supone de este modo ya que se puede observar la presencia de unidades formacionales de origen marino no deformadas en el macizo, las cuales se pueden encontrar en las cuencas circundantes con distintos grados de deformación. Con el fin de aportar al conocimiento acerca de la formación y el estado actual de dicha zona, se realizó la adaptación de un modelo gravimétrico tridimensional (Tassara et al., 2006 y Tassara y Echaurren, 2012) al área del Macizo Norpatagónico. Para realizar la adaptación y el análisis de los resultados se utilizó el programa de modelado gravimétrico y magnético tridimensional e interactivo IGMAS+ (Götze, 1978 y 1984, Götze y Lahmeyer 1988 y Schmidt y Götze, 1998) y se extrajeron datos de anomalías de Bouguer del modelo geopotencial EGM2008 (Pavlis et al., 2012). Se observó un buen ajuste entre las superficies calculada y observada para el modelo. Se extrajo y mapeó la superficie de la discontinuidad de Mohorovicic para el modelo, pudiéndose notar una corteza de espesor aproximadamente constante y superior a los 36 km para el área del macizo rodeada de zonas de espesor cortical inferior hacia el Este y Norte mientras que en su límite Oeste se observan áreas de corteza más potente. La adaptación deja una pequeña zona del sudeste del macizo fuera del modelo con lo cual no se tiene información de lo que ocurre en el límite sur del mismo.The North Patagonian Massif is an almost undeformed plateau surrounded by basins with some degree of deformation from which it stands between 500 to 700 m. The massif suffered a sudden uplift of about 1200 m in the Paleogene, hypothetically, caused by epeirogenic movements. The latter affirmation is based on the presence of undeformed marine formational units in the massif, which show some degree of tertiary deformation in the surrounding basins. An adaptation of a tridimensional gravimetric model to the North Patagonian Massif area was made with the aim ofcharacterize this scarcely studied area that have interesting characteristics. To make the adaptation and analysis of the results, a tridimensional and interactive gravity and magnetic modeling software called IGMAS+ was used and the Bouguer anomaly data were extracted of the EGM2008 geopotential model. A difference between the calculated and the observed surfaces of -21 mGal in mean value can be observed in the original model for the study area. A new fit was made in the area, and a difference between surfaces of -5,4 mGal in mean value was achieved which was considerably better than the original model fit for the NPM. The Mohorovicic discontinuity of the model was extracted and mapped. A crust with a thick between 35 and 45 km could be observed in the massif area surrounded by lower thickness areas in its North, West and East limits. No information about the South limit is available since this area remained outside the original model.Fil: Gómez Dacal, María Laura. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata; Argentina. Universidad Nacional de La Plata. Facultad de Ciencias Astronómicas y Geofísicas. Departamento de Gravimetría; ArgentinaFil: Tocho, Claudia. Universidad Nacional de La Plata. Facultad de Ciencias Astronómicas y Geofísicas. Departamento de Gravimetría; ArgentinaFil: Aragon, Eugenio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Investigaciones Geológicas. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. Centro de Investigaciones Geológicas; Argentina. Universidad Nacional de La Plata. Facultad de Ciencias Astronómicas y Geofísicas. Departamento de Gravimetría; Argentin

Alternative method for concentration retrieval in differential optical absorption spectroscopy atmospheric gas pollutant measurements

Differential optical absorption spectroscopy is a widely used technique for open-column atmospheric-gas pollution monitoring. The concentration retrieval is based on the fitting of the measured differential absorbance through the Lambert-Beer law. We present an alternative method for calculating the gas concentration on the basis of the proportionality between differential absorbance and differential absorption cross section of the gas under study. The method can be used on its own for single-component analysis or as a complement to the standard technique in multicomponent cases. The performance of the method for the case of cross interference between two gases is analyzed. The procedure can be used with differential absorption cross sections measured in the laboratory or taken from the literature. In addition, the method provides a criterion to discriminate against different species having absorption features in the same wavelength range

Photophysical Processes of Polymethlne Dyes

Laser Hash photolysis, laser induced optoacoustic spectroscopy (LIOAS), and fluorescence data were used for the study of the photophysical deactivation processes of excited 3,3 diethylthiadicarbocyanine iodide (DTDCI). Direct excitation of this molecule in air saturated methanol solutions at room temperature results in the formation of only one transient species, a photoisomer, the spectrum of which was derived for the 600-680 nm spectral range. The energy content difference between the ground state of the stable form and that of the photoisomer was evaluated, $latex \Delta E = 0.15 \pm 0.15 \enspace eV$, as well as limit values for the photoisomer fluorescence quantum efficiency $latex(\Phi _{f} ^{P}) < 0.2$ and for the quantum yield for the back photoisomerization from the first excited singlet state of the photoisomer to the ground state of the stable form $latex(\Phi _{PN}\leq 0.14)$