LAS TRANSFORMACIONES DEL ESPACIO RURAL EN EL DEPARTAMENTO CAPAYÁN, PROVINCIA DE CATAMARCA, ARGENTINA

El departamento Capayán se ubica en la región central de la provincia de Catamarca, a 65 Km. de la ciudad capital .Su superficie es de 4.248 km2 y la población es de 14.184 hab. Se pretende analizar las grandes transformaciones que se dieron en el espacio rural del departamento Capayán. El diagnóstico del espacio analizado se organiza sobre la base de una selección preliminar de localidades a relevar. La recopilación de información se recopiló sobre la realización de entrevistas y la búsqueda de fuentes complementarias de información y trabajo de campo Se seleccionó los grupos de productores a partir de una idea a priori de las producciones que los mismos desarrollan.La zona de oasis de conos se ubica en Capayán, en los de deyección de los faldeos orientales de la sierra de Ambato, que presenta explotaciones pequeñas y destinadas especialmente a la actividad fruti hortícola. Se caracteriza por ser una zona en la que la superficie destinada a la actividad agrícola fue creciendo.Los resultados nos permiten determinar que las transformaciones del espacio rural se inician hacia fines de la década del 60 y comienzo del 70, surgen las Colonia Nueva Coneta y Del Valle destinadas a la agricultura (hortalizas, frutales).Pero a partir de la década del 90 el crecimiento de la superficie fue muy significativo, la frontera agropecuaria se expandió como fruto del desarrollo de empresas beneficiadas con el régimen de diferimientos impositivos y cuya actividad en esta zona se destinó al cultivo de olivo, algodón, citrus y duraznero.

APROXIMACIONES A LAS TRANSFORMACIONES ESPACIO-TEMPORALES DEL HUMEDAL JUAN AMARILLO EN LA CIUDAD DE BOGOTÁ

La crisis ambiental irrumpe en el escenario mundial desde finales del siglo pasado como uno de los problemas más importantes para la existencia de la humanidad. En el afán de “progreso”[1] y “desarrollo”, los seres humanos se han dedicado a expoliar la naturaleza; despilfarrando los recursos que el Planeta Tierra proporciona, bajo la lógica de un sistema económico que los capitaliza y genera una explotación intensiva y sin límites. Para comprender las transformaciones globales del mundo actual se justifica un análisis crítico y reflexivo sobre el impacto de las acciones antrópicas sobre el entorno, que abra el camino hacia nuevas posibilidades en la relación ser humano-ambiente en el contexto mundial contemporáneo. Colombia, es uno de los países con mayor diversidad ambiental no sólo por su flora y fauna sino también por su riqueza hídrica. Esta última ha sido la menos protegida[2] pese a las políticas ambientales del país, lo cual pone en cuestión la formación ambiental de los ciudadanos quienes hoy se muestran indiferentes frente a las problemáticas de su medio. Consiguiente, es ineludible la tarea de generar desde una escala local transformaciones en el actuar, sentir y pensar de los ciudadanos. Por esta razón, se hace referencia a la influencia de la urbanización, en los cambios ambientales del humedal Juan Amarillo ubicado en la ciudad de Bogotá, en las localidades de Suba y Engativá. Una de las causas de la modificación vigente de este ecosistema es la construcción de avenidas como la Avenida Ciudad de Cali y el proyecto a futuro de la Avenida Longitudinal de Occidente. Evidenciando la marginación de la cuestión ambiental en pro del desarrollo a través de la urbanización. [1] La crisis ecológica manifiesta el quiebre de una concepción de mundo basada en el progreso, respecto a dos infinitos a saber: el infinito de los recursos de la Tierra y el infinito del futuro;  expresando el ideal de una Tierra inagotable en sus recursos destinada al avance ilimitado con dirección al futuro. La conciencia de crisis reconoce la limitación en la apropiación y explotación de los recursos naturales evidenciando la imposibilidad de los discursos que apuntan hacia el crecimiento indefinido. Véase al respecto: Leonardo Boff, Ecología: grito de la Tierra, grito de los pobres, Editorial Trotta, Madrid, 2002, especialmente el Capitulo 1, pp. 13-52. Presentado en el XIII Encuentro de Geógrafos de América Latina, 25 al 29 de Julio del 2011 Universidad de Costa Rica - Universidad Nacional, Costa Rica

TRANSFORMACIONES POLÍTICAS EN EL ESTADO MEXICANO SUREÑO DE GUERRERO 1977–2008

En la historia política de México, actualmente subdivide en dos segmentos: el primero tiene que ver con el Partido Revolucionario Institucional (PRI), cuando era partido hegemónico y el segundo segmento cuando se inició la competitividad política y el PRI es desplazado, de manera importante, del poder. El objetivo del documento, consiste en analizar cómo se ha transformado la geografía política-electoral del estado de Guerrero entre 1977–2008. La metodología empleada sigue los principios básicos de la Geografía Política, principalmente, localización, causalidad e interrelación del electorado mexicano. Entre los resultados se encuentran tres mapas a nivel estatal con 81 municipios y la distribución espacial de cada una de las expresiones políticas, un cuarto mapa que muestra las siete regiones económicas del estado y la cobertura espacio-temporal del electorado y finalmente un gráfico y tres imágenes que incluyen la representatividad de cada uno de los institutos políticos en Guerrero, México.

• NEOLIBERALISMO, CRISIS ECONÓMICA ACTUAL Y TRANSFORMACIONES EN EL ESPACIO SOCIAL MUNDIAL

 Desde mediados del año 2009 se  generó una crisis económica mundial que atribuye su inicio a las burbujas financieras del sistema hipotecario estadounidense y continuó con el ya conocido “efecto dominó”: donde la mayoría de los países han experimentado descensos en sus niveles de crecimiento económico y en el poder adquisitivo de su moneda frente al dólar; situación que desembocó en desempleo, inflación y agudización de los problemas sociales y políticos.El paradigma político-económico llamado neoliberalismo, caracterizado por sus constantes y recurrentes crisis se ha manifestado de formas diversas en el espacio social. El presente trabajo busca elaborar una propuesta metodológica sobre la manera de abordar dicha problemática desde las ciencias económica y geográfica.Se pretende analizar y eslabonar, concretamente, los conceptos  de Crisis y Espacio en el marco del Neoliberalismo, sobre la base de los puntos convergentes entre las escuelas de la Crítica de la Economía Política (Marx) y la Geografía Crítica (Lefebvre y Santos), dos escuelas preocupadas por entender críticamente la realidad social. 

Extensión: transformaciones vitales en la relación universidad-comunidad

La extensión universitaria, como quehacer académico de gran envergadura, quedó plasmada desde la fundación de la Universidad Nacional, como una de las tres áreas académicas constitutivas. El Estatuto Orgánico de 1976, así como el actual, han fijado la gran importancia al compromiso de interacción permanente universidad-sociedad donde ambas se transforman recíprocamente para impactar en la actualidad y en el futuro de ambas.AbstractUniversity outreach, as a major academic task, was given expression since the very beginning of the Universidad Nacional as one of its three academic founding areas. Both, the 1976 and the 1993 University’s Statute Acts set great importance to the permanent based commitment between university and society. In such relationship, university and society are, currently and prospectively, mutually transformed. 

The Behavior of Hydroxyl Units of Synthetic Goethite and its Dehydroxylated Product Hematite

The behavior of the hydroxyl units of synthetic goethite and its dehydroxylated product hematite was characterized using a combination of Fourier transform infrared (FTIR) spectroscopy and X-ray diffraction (XRD) during the thermal transformation over a temperature range of 180-270 degrees C. Hematite was detected at temperatures above 200 degrees C by XRD while goethite was not observed above 230 degrees C. Five intense OH vibrations at 3212-3194, 1687-1674, 1643-1640, 888-884 and 800-798 cm(-1), and a H2O vibration at 3450-3445 cm(-1) were observed for goethite. The intensity of hydroxyl stretching and bending vibrations decreased with the extent of dehydroxylation of goethite. Infrared absorption bands clearly show the phase transformation between goethite and hematite: in particular. the migration of excess hydroxyl units from goethite to hematite. Two bands at 536-533 and 454-452 cm(-1) are the low wavenumber vibrations of Fe-O in the hematite structure. Band component analysis data of FTIR spectra support the fact that the hydroxyl units mainly affect the a plane in goethite and the equivalent c plane in hematite.

Investigation of RuO2/Ta2O5 thin film evolution by thermogravimetry combined with mass spectrometry

The thermal evolution process of RuO2–Ta2O5/Ti coatings with varying noble metal content has been investigated under in situ conditions by thermogravimetry combined with mass spectrometry. The gel-like films prepared from alcoholic solutions of the precursor salts (RuCl3·3H2O, TaCl5) onto titanium metal support were heated in an atmosphere containing 20% O2 and 80% Ar up to 600 °C. The evolution of the mixed oxide coatings was followed by the mass spectrometric ion intensity curves. The cracking of retained solvent and the combustion of organic surface species formed were also followed by the mass spectrometric curves. The formation of carbonyl- and carboxylate-type surface species connected to the noble metal was identified by Fourier transform infrared emission spectroscopy. These secondary processes–catalyzed by the noble metal–may play an important role in the development of surface morphology and electrochemical properties. The evolution of the two oxide phases does not take place independently, and the effect of the noble metal as a combustion catalyst was proved.

Speaker identification using higher order spectral phase features and their effectiveness vis-a-vis Mel-Cepstral features

The effectiveness of higher-order spectral (HOS) phase features in speaker recognition is investigated by comparison with Mel Cepstral features on the same speech data. HOS phase features retain phase information from the Fourier spectrum unlikeMel–frequency Cepstral coefficients (MFCC). Gaussian mixture models are constructed from Mel– Cepstral features and HOS features, respectively, for the same data from various speakers in the Switchboard telephone Speech Corpus. Feature clusters, model parameters and classification performance are analyzed. HOS phase features on their own provide a correct identification rate of about 97% on the chosen subset of the corpus. This is the same level of accuracy as provided by MFCCs. Cluster plots and model parameters are compared to show that HOS phase features can provide complementary information to better discriminate between speakers.

Thermal transition properties of spagehetti measured by Differential Scanning Calorimetry (DSC) and Thermal Mechanical Compression Test (TMCT)

Glass transition temperature of spaghetti sample was measured by thermal and rheological methods as a function of water content.

Structural health monitoring of bridges using acoustic emission technology and signal processing techniques

Structural health monitoring (SHM) is the term applied to the procedure of monitoring a structure’s performance, assessing its condition and carrying out appropriate retrofitting so that it performs reliably, safely and efficiently. Bridges form an important part of a nation’s infrastructure. They deteriorate due to age and changing load patterns and hence early detection of damage helps in prolonging the lives and preventing catastrophic failures. Monitoring of bridges has been traditionally done by means of visual inspection. With recent developments in sensor technology and availability of advanced computing resources, newer techniques have emerged for SHM. Acoustic emission (AE) is one such technology that is attracting attention of engineers and researchers all around the world. This paper discusses the use of AE technology in health monitoring of bridge structures, with a special focus on analysis of recorded data. AE waves are stress waves generated by mechanical deformation of material and can be recorded by means of sensors attached to the surface of the structure. Analysis of the AE signals provides vital information regarding the nature of the source of emission. Signal processing of the AE waveform data can be carried out in several ways and is predominantly based on time and frequency domains. Short time Fourier transform and wavelet analysis have proved to be superior alternatives to traditional frequency based analysis in extracting information from recorded waveform. Some of the preliminary results of the application of these analysis tools in signal processing of recorded AE data will be presented in this paper.

Silylation of layered double hydroxides via a calcination−rehydration route

Silylated layered double hydroxides (LDHs) were synthesized through a surfactant-free method involving an in situ condensation of silane with the surface hydroxyl group of LDHs during its reconstruction in carbonate solution. X-ray diffraction (XRD) patterns showed the silylation reaction occurred on the external surfaces of LDHs layers. The successful silylation was evidenced by 29Si cross-polarization magic-angle spinning nuclear magnetic resonance (29Si CP/MAS NMR) spectroscopy, attenuated total reflection Fourier transform infrared (ATR FTIR) spectroscopy, and infrared emission spectroscopy (IES). The ribbon shaped crystallites with a “rodlike” aggregation were observed through transmission electron microscopy (TEM) images. The aggregation was explained by the T2 and T3 types of linkage between adjacent silane molecules as indicated in the 29Si NMR spectrum. In addition, the silylated products show high thermal stability by maintained Si related bands even when the temperature was increased to 1000 °C as observed in IES spectra.

Numerical schemes and multivariate extrapolation of a two-dimensional anomalous sub-diffusion equation

Anomalous dynamics in complex systems have gained much interest in recent years. In this paper, a two-dimensional anomalous subdiffusion equation (2D-ASDE) is considered. Two numerical methods for solving the 2D-ASDE are presented. Their stability, convergence and solvability are discussed. A new multivariate extrapolation is introduced to improve the accuracy. Finally, numerical examples are given to demonstrate the effectiveness of the schemes and confirm the theoretical analysis.

On the affinity of Chuaria–Tawuia complex : a multidisciplinary study

In this study, biometric and structural engineering tool have been used to examine a possible relationship within Chuaria–Tawuia complex and micro-FTIR (Fourier Transform Infrared Spectroscopy) analyses to understand the biological affinity of Chuaria circularis Walcott, collected from the Mesoproterozoic Suket Shales of the Vindhyan Supergroup and the Neoproterozoic Halkal Shales of the Bhima Group of peninsular India. Biometric analyses of well preserved carbonized specimens show wide variation in morphology and uni-modal distribution. We believe and demonstrate to a reasonable extent that C. circularis most likely was a part of Tawuia-like cylindrical body of algal origin. Specimens with notch/cleft and overlapping preservation, mostly recorded in the size range of 3–5 mm, are of special interest. Five different models proposed earlier on the life cycle of C. circularis are discussed. A new model, termed as ‘Hybrid model’ based on present multidisciplinary study assessing cylindrical and spherical shapes suggesting variable cell wall strength and algal affinity is proposed. This model discusses and demonstrates varied geometrical morphologies assumed by Chuaria and Tawuia, and also shows the inter-relationship of Chuaria–Tawuia complex. Structural engineering tool (thin walled pressure vessel theory) was applied to investigate the implications of possible geometrical shapes (sphere and cylinder), membrane (cell wall) stresses and ambient pressure environment on morphologically similar C. circularis and Tawuia. The results suggest that membrane stresses developed on the structures similar to Chuaria–Tawuia complex were directly proportional to radius and inversely proportional to the thickness in both cases. In case of hollow cylindrical structure, the membrane stresses in circumferential direction (hoop stress) are twice of the longitudinal direction indicating that rupture or fragmentation in the body of Tawuia would have occurred due to hoop stress. It appears that notches and discontinuities seen in some of the specimens of Chuaria may be related to rupture suggesting their possible location in 3D Chuaria. The micro-FTIR spectra of C. circularis are characterized by both aliphatic and aromatic absorption bands. The aliphaticity is indicated by prominent alkyl group bands between 2800–3000 and 1300–1500 cm−1. The prominent absorption signals at 700–900 cm−1 (peaking at 875 and 860 cm−1) are due to aromatic CH out of plane deformation. A narrow, strong band is centred at 1540 cm−1 which could be COOH band. The presence of strong aliphatic bands in FTIR spectra suggests that the biogeopolymer of C. circularis is of aliphatic nature. The wall chemistry indicates the presence of ‘algaenan’—a biopolymer of algae.