Thermal Study of Aluminum Trifluoromethyl Sulfonate as Effective Catalyst for the Polymerization of Epoxidized Linseed Oil

Artículo derivado de un Tesista de Doctorado en Ciencia de MaterialesIt was studied the Aluminum Trifluoromethyl Sulfonate ((Al(OTf)3) as a very effective catalyst to polymerize Epoxidized Linseed Oil (ELO) in bulk, in a very wide range of temperatures, from room temperature (25°C) to the peak temperature of the exothermal curve of polymerization. Those temperatures and times of polymerization were depending on the amount of catalyst, which was evaluated in a very wide range of loads, from 0.5 x10-3 to 70 x10-3 molar percent. As an instance, a 55 x10-3 molar percent of catalyst showed at exothermic curve from 82 to 187°C with the peak temperature at 120.3°C. This preparation allows to ELO polymerize at 25°C in 24 hrs, at 60°C in 1hr and at 80°C in 20 min and only takes 7 min to polymerize at peak temperature. The study of the opening of the epoxy ring and polymerization of ELO was made by DSC and FTIR-HART analysis. Also was evidenced by 1H-NMR that no side reactions are promoted by this catalyst at least in the first minutes of reaction

A near zero consumption building as an urban acupuncture for a vertical slum. A case study in the city of Malaga, Spain

Vertical slum is defined as a particularly vulnerable height building, with serious problems of functionality, safety and habitability. Venezuela’s Tower of David is a famous example. Vertical slums are associated with an important level of physical degradation, coupled with a precarious socioeconomic situation of its occupants. Their inability to create a community for proper and mandatory maintenance increases their physical deterioration. The abandonment of the original owners is replaced by a system of occupation and illegal activities. In many cases, with an interest in maintaining the building in a state of precariousness, which annuls any attempt to rehabilitate it Facing this situation, the intervention is proposed through an urban acupuncture project, understood as a project of expropriation and physical rehabilitation of the building, associated to a project of social rehabilitation in a disadvantaged environment. It is about creating a hybrid building associated with four objectives 1- Create a hybrid building with a mixed offer of social and housing services: sheltered housing for seniors, residence and accommodation for young entrepreneurs. The idea of a social condenser is related to studies of the hybrid building such as the Downtown Athletic Club in New York, or the Rokade Tower and Maartenshof residence (Groningen, The Netherlands). 2- Incorporate the sustainability parameters directed to a building almost zero. 3- Incorporate a model of provision of housing services, managed by the municipality, but with the possibility of incorporating NGOs 4- Design a social rehabilitation project that facilitates the creation of a web of social-based companies or cooperatives that fosters entrepreneurship, and that can actively participate in the rehabilitation and maintenance of the neighborhood itself. This paper applies these principles to a building in Malaga as a case study and 10 strategies are developed and analysed in regards to its physical, social and sustainable transformation.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

Circumnuclear structure and kinematics in the active galaxy NGC 6951

A study is presented of the central structure and kinematics of the galaxy NGC 6951, by means of broad band B'IJK images and high resolution high dispersion longslit spectroscopy, together with archival HST WFPC2 V and NICMOS2 J and H images. We find that there is evidence of two modes of star formation, in bursts and continuously. The equivalent width of the CaII triplet absorption lines show that, in the metal rich central region, the continuum is dominated by a population of red supergiants. The gaseous and stellar kinematics along three slit position angles, suggest the existence of a hierarchy of disks within disks, whose dynamics are decoupled at the two ILRs, that we find at 180 pc and at 1100 pc. This is supported by the structure seen in the high resolution HST images. The nucleus is spatially resolved within a radius of 1.5 arcsec, just inside the innermost ILR. Outside the iILR, the stellar CaT velocity profile is resolved into two components, associated with the bar and the disk. Several results indicate that this is a dynamically old system. It is thus possible that a nuclear bar has existed in NGC 6951 that drove the gas towards the nucleus, as in the bars within bars scenario, but that this bar has already dissolved by the gas accumulated within the circumnuclear region. We discuss the possibility that the kinematical component inside the iILR could be due to a nuclear outflow produced by the combined effects of SN and SN remnants, or to a nuclear disk, as in the disk within disk scenario that we propose for the fueling of the AGN in NGC 6951.Comment: 14 pages, 16 figures. Accepted for publication in Astronomy and Astrophysics. High resolution images in http://www.iaa.es/~eperez/research/degas.htm

Gestión educativa y recursos digitales en los docentes de una institución educativa privada de Mirones Bajos, Lima, 2020

a presente investigación tuvo como objetivo establecer la correlación que existe entre la Gestión Educativa y los recursos digitales en los docentes de una institución educativa privada de Mirones Bajos, Lima, 2020. Fue una investigaciónde enfoque cuantitativo, de diseño no experimental descriptivo correlacional. La muestra estuvo conformada por 30 docentes de la institución educativa privada de Mirones Bajos, Lima, 20202. Para recolectar los datos se empleó como técnicala encuesta, a través de un cuestionario, cuya confiabilidad con el alfa de Cronbach fue de 0.913 para la variable Gestión Educativa y de 0, 877 para la variable Recursos digitales, lo que representó una confiabilidad excelente y buenarespectivamente. Estos resultados las valoran como aplicables para el estudio. Para la contrastación de hipótesis, esto es, para demostrar la relación entre las variables se empleó el estadístico Rho de Spearman por resultar ser muestras no paramétricas al realizar la prueba de normalidad con Shapiro Wilk. Se obtuvo como coeficiente de correlación entre las variables Gestión educativa y Recursosdigitales el valor de 0,818 y un valor de significancia p=0,000<0,05. De ello se estableció que el nivel de correlación entre las variables fue alta y positiva

NIC 19 y su incidencia en la razonabilidad de los estados financieros de las empresas consultoras en el distrito de Jesús María, en el año 2014

El presente trabajo de investigación con el título “NIC 19 Y SU INCIDENCIA EN LA RAZONABILIDAD DE LOS ESTADOS FINANCIEROS DE LAS EMPRESAS CONSULTORAS EN EL DISTRITO DE JESÚS MARÍA, EN EL AÑO 2014”, se realizó con la finalidad de demostrar de qué manera incide la aplicación de la NIC 19 en los informes contables de las empresas consultoras en el distrito de Jesús María. Para ello se establece un objetivo principal el cual es: Determinar la incidencia de la Nic 19 en la razonabilidad de los Estados Financieros de las empresas Consultoras, siendo así que de este objetivo se desprenden 2 objetivos específicos. Las variables que se han determinado son: Norma Internacional de Contabilidad 19 (NIC 19) como Variable independiente y Razonabilidad como variable dependiente, y al finalizar la investigación se podrá confirmar la hipótesis planteada

Artesanos y Circulación de objetos en el Bajo Magdalena: la industria de concha y el intercambio fluvial en el norte de Colombia entre los siglos XII-XVI d.C.

The peoples of the pre-Hispanic Colombian Caribbean they were skilled artisans and merchants during the centuries before the Spanish conquest. In different places in the región you can find objects of great craftsmanship. The lack of studies on these goods has not allowed us to see the intese trade and interactions that the indigenous communities that lived in the región had. The present investigation is base on the taxonomic and tecnological study of the shell workshops found in Plato, as well as its function as a fluvial port locate on the Magdalena river, a place that serves as an archetype for other posible sites not found yet in the Caribbean plains.Los pueblos del Caribe colombiano prehispánico fueron hábiles artesanos y comerciantes durante los siglos previos a la conquista española. En diversos sitios de la región se pueden encontrar objetos de una gran calidad artesanal. La falta de estudios sobre estos bienes no ha permitido ver el intenso comercio e interacciones que tuvieron las comunidades indígenas que vivieron en la región. La presente investigación, parte del estudio taxonómico y tecnológico de los talleres de concha encontrados en Plato, así como su función de puerto fluvial ubicado en el río Magdalena, lugar que sirve de arquetipo para otros posibles sitios aun no encontrados en las llanuras del Caribe

Sensing parameters as a function of the chemical structure and thickness of two poly(styrene)-type based composites with carbon black

Sensing parameters of polymer composite layers were studied as a function of the polymer matrix structure and the initial resistance of the composite layers. Composites of Poly(styrene) and 4-Chloro-poly(styrene) at the same volume fraction of carbon black (8.7% V/V) were prepared by ultrasonic dispersion. Composite layers with different thicknesses and resistances were deposited by spin coating technique on flexible substrates from commercial cellulose acetate foils. Both kind of composite layers with initial resistances of 10, 50 and 100 kΩ were exposed to Acetone, Tetrahydrofuran, Chloroform and Toluene. Results evidenced that selectivity is very dependent on the chemical structure of the polymer matrix and sensitivity to the initial film electrical resistance. PS-based composite series were selective to Tetrahydrofuran whereas that 4ClPS-based composite series were selective to Acetone as expected due to their solubility parameters. For both composite series sensitivity increased for layers with less than 100 kΩ resistances. For all tested solvents 4ClPS-based composites showed higher sensitivities than PS-based composites. The response times for both series were into the range of 2 to 150 s and recovery times were in the range of 30 to 2000 s.SIEA-UAEM, 1025/2014RIF

Effective and Fast Epoxidation Reaction of Linseed Oil Using 50 wt% Hydrogen Peroxyde

Artículo de Investigación derivado de Trabajo de Tesis de Doctodado en Ciencia de MaterialesEpoxidation of linseed oil was performed with peracetic acid formed in situ by the reaction of hydrogen peroxide and acetic acid in the presence of Amberlite 120H as catalyst, and toluene as solvent. Some variables were evaluated as temperature and the molar ratio and solution of aqueous hydrogen peroxide (30 and 50 wt%) for obtaining a maximum of yield and conversion of epoxidized oil. The characterization of conversion of double bonds (DB) to epoxy ring, the relative percentage of epoxidation and selectivity, were performed by 1H-NMR and FTIR-HART. The conditions rendered a maximum epoxidation of 93.4%, a conversion or double bonds of 97% and a selectivity of 96.3% were obtained at 80°C, employing a molar ratio 1:1.5 of double bonds (DB) to H2O2 (50 wt%), 1:0.5 of DB to acetic acid, and 25 wt% of catalyst, in only 50 min and with a good reproducibility (±1.1%)

El entorno de la Iglesia-Fortaleza de Nª Sª de la Encarnación de Motril (Granada). Modulación proyectual para su recuperación, puesta en valor y difusión

La iglesia fortaleza de Nuestra Señora de la Encarnación fue uno de los principales baluartes defensivos del siglo XVI en la costa granadina, tanto en su escala territorial y urbana como en la constructiva, ya que debía proteger la vega, la costa y el camino de acceso a Granada. La pacificación del territorio y su transformación en Colegiata en el s. XVIII desfigura su configuración inicial por las continuas ampliaciones. Tras la Guerra Civil, la iglesia es restaurada y se eliminan numerosos añadidos barrocos, recuperando su imagen defensiva inicial. El proyecto de rehabilitación del espacio público circundante propone una metodología de trabajo que pretende mostrar la evolución histórica de la iglesia. Para ello establece tres niveles de intervención: el valor simbólico-conceptual de su diseño, la reconstrucción material de elementos defensivos singulares y la difusión del proceso.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tec

Organization of the Zone of Transition between the Pretectum and the Thalamus, with Emphasis on the Pretectothalamic Lamina

The zone of transition between the pretectum, derived from prosomere 1, and the thalamus, derived from prosomere 2, is structurally complex and its understanding has been hampered by cytoarchitectural and terminological confusion. Herein, using a battery of complementary morphological approaches, including cytoarchitecture, myeloarchitecture and the expression of molecular markers, we pinpoint the features or combination of features that best characterize each nucleus of the pretectothalamic transitional zone of the rat. Our results reveal useful morphological criteria to identify and delineate, with unprecedented precision, several [mostly auditory] nuclei of the posterior group of the thalamus, namely the pretectothalamic lamina (PTL; formerly known as the posterior limitans nucleus), the medial division of the medial geniculate body (MGBm), the suprageniculate nucleus (SG), and the ethmoid, posterior triangular and posterior nuclei of the thalamus. The PTL is a sparsely-celled and fiber rich flattened nucleus apposed to the lateral surface of the anterior pretectal nucleus (APT) that marks the border between the pretectum and the thalamus; this structure stains selectively with the Wisteria floribunda agglutinin (WFA), and is essentially immunonegative for the calcium binding protein parvalbumin (PV). The MGBm, located medial to the ventral division of the MGB (MGBv), can be unequivocally identified by the large size of many of its neurons, its dark immunostaining for PV, and its rather selective staining for WFA. The SG, which extends for a considerable caudorostral distance and deviates progressively from the MGB, is characterized by its peculiar cytoarchitecture, the paucity of myelinated fibers, and the conspicuous absence of staining for calretinin (CR); indeed, in many CR-stained sections, the SG stands out as a blank spot. Because most of these nuclei are small and show unique anatomical relationships, the information provided in this article will facilitate the interpretation of the results of experimental manipulations aimed at the auditory thalamus and improve the design of future investigations. Moreover, the previously neglected proximity between the MGBm and the caudal region of the scarcely known PTL raises the possibility that certain features or roles traditionally attributed to the MGBm may actually belong to the PTL