Development of Technologies for Local Composting of Food Waste From Universities

[Abstract] The amount of biowaste generated by university canteens (BWUC) in the faculties of the University of A Coruña (UDC) varies between 6 and 100 kg/day. In addition, the gardening services of the campus generate even higher amounts of garden waste (GrW), including pruning, which, once crushed, serves as bulking material for composting the biowaste from the canteens. Decentralized composting has been chosen with the aim of producing high quality organic fertilizers for university urban gardens while reducing the environmental burdens of both waste management and agricultural practice. Small static home composters of 340 L (SHC) for smaller amounts of generation (up to 20 kg BWUC/day) were used, while, for faculties of higher generation (up to 40 kg BWUC/day on average), the first composting stage was carried out in a closed and dynamic composter (DC). The dynamic composter was designed and built specifically for this project and its features were improved and optimized throughout the study. The pilot project was carried out in two centers of the UDC, which are known as the Philology Faculty (PF) and the School of Architecture (SA). All the organic waste generated by the canteens of these two colleges from January 2011 to July 2011 (approximately 3000 kg) was treated. Composting in SHC included a thermophilic phase that extended one month beyond the loading period for which thermophilic temperatures were also recorded. The use of the DC as the first stage in combination with static composters (SC) for the maturation stage reduced the overall thermophilic phase to 6–8 weeks. The complete maturation (Rottegrade class IV-V) was achieved after about four months in SHC and after two months when using the combined DC-SC system, if the right conditions of moisture were maintained. The chemical quality of the compost produced was compatible with Class A of Spanish legislation (equivalent to organic farmer quality) and the C/N ratio ranged from 9 to 15 depending on the relation BWUC:GrW

Modeling the Self-Assembly of Cage Molecules

Els materials moleculars porosos constituïts per cage molecules estan despertant l'interès de la comunitat científica a causa de les seves prometedores aplicacions entre les quals es troben les separacions químiques, adsorció de gasos o com agents per a augmentar la porositat en materials compostos. En els darrers anys, el desenvolupament de les organic cage molecules ha millorat enormement. La síntesi d'aquests compostos en reaccions one-pot que es basen en l'autoassemblatge dels monòmers constituents s’ha convertit en una pràctica habitual. S'han fet alguns passos per a entendre el mecanisme subjacent de l'autoassemblatge de la molècula, principalment per a metallocages, i per a veure quins paràmetres controlen el producte de la reacció, però encara queda molt per descobrir. En aquest treball es dóna un estudi detallat sobre la reacció de condensació d'imina que regeix l'autoassemblatge de les imine cages, en el qual s'aconsegueix reproduir dades cinètiques experimentals. A més, combinant química quàntica computacional i modelització cinètica presentem un model compatible amb els diferent reactors utilitzats per a la síntesi de la CC1 imine cage. D'aquest estudi combinat, deduim quins intermedis tenen un paper més important en el producte obtingut, així com de quina manera altres variables, concentracions inicials i temperatura, influeixen en el producte obtingut.Los materiales moleculares porosos constituidos por cage molecules están despertando el interés the la comunidad cientifica a causa de sus prometedoras aplicaciones, como separaciones quimicas, adsorción de gases o como agentes para aumentar la porosidad en materiales compuestos. En los últimos años, el desarrollo de las organic cage molecules ha mejorado drásticamente. La síntesis de estos compuestos en reacciones one-pot que se basan en el autoensamblaje de los monomeros constituyentes se ha convertido en una práctica habitual. Se han dado algunos para entender el mecanismo del autoensambleje de la molécula, principalmente para metallocages, y para ver que parámetros controlan el producto de la reacción, pero aún queda mucho por descubrir. En este trabajo se da un estudio detallado sobre el mecanismo de reacción de la condensación de imina que gobierna el autoensamblaje de las imine cages, en el cual se consigue reproducir datos cinéticos experimentales. A continuación, combinando química quántica computacional y modelización cinética presentamos un modelo compatible con los differentes reactores utilizados para la síntesis de la CC1 imine cage. De este estudio combinado, derivamos que intermedios tienen un papel más importante en el producto obtenido así como en que manera otras variables, concentraciones iniciales y temperatura, influencian el producto obtenido.Porous molecular materials constituted by cage molecules are gathering the interest of the scientific community due to their promising applications, like chemical separations, gas adsorption or as agents to increase the porosity in composite materials. In the recent years, the development of organic cage molecules has vastly improved. The synthesis of these compounds in one-pot reactions relying on the self-assembly of the constituting monomers is now a common practice. Some steps have been taken to understand the underlying mechanism of the molecule’s self-assembly, mostly for metallocages, and to see which parameters control the reaction outcome, but there is still much to uncover. In this work we provide a detailed study on the imine condensation reaction which governs the self-assembly of imine cages, in which reproduction of the raw experimental kinetic data is achieved. Then, through a combined approach of computational quantum chemistry and kinetic modeling we present a model compatible with the different reactor setups used for the synthesis of the CC1 imine cage. From this combined study, we derive which intermediates play a major role in the outcome product, as well as how other variables, initial concentrations and temperature, influence the outcome

Implementación de una formulación analítica del LEMP para estimar el desempeño de líneas de distribución frente a rayos

This paper presents the implementation of an analytical formulation to calculate the lightning electromagnetic pulse (LEMP) assuming a current wave-shape linearly rising with flat top and a transmission Line (TL) return-stroke model. It also describes the development of the expressions for the image dipoles required to calculate the vertical electric field, the azimuthal magnetic field and, specially, the horizontal electric field. The expressions to calculate the contribution of source dipoles were detailed in a previous publication by other authors. The complete formulation is used to calculate electromagnetic fields and lightning-induced voltages on a typical overhead distribution line. The results were compared with traditional formulas to calculate the LEMP (such as Rubinstein’s) and to calculate induced voltages (such as Rusck’s) showing errors below 1%. If a more complex wave shape was used (such as Heidler’s), errors below 5% were found. Additionally, the formula was employed to calculate the flashover rate of a distribution line above a ground with infinite and finite conductivity. Errors less than 5% were found compared to the results obtained in the IEEE 1410 Standard. On the other hand, the computation time required to the assessment of an overhead line indirect lightning performance is reduced by half when the analytical formula is used.Este artículo presenta la implementación de una formulación analítica para calcular el campo electromagnético producido por rayo (LEMP), asumiendo una forma de onda de la corriente tipo rampa plana y un modelo de línea de transmisión (TL) para la descarga de retorno. Se presenta el desarrollo de las expresiones para los dipolos imágenes necesarios para calcular el campo eléctrico vertical, el campo magnético azimutal y especialmente el campo eléctrico horizontal. Las expresiones para calcular la contribución de los dipolos fuentes se presentaron en una publicación previa de otros autores. La formulación completa se usó para calcular los campos electromagnéticos y las tensiones inducidas por rayo en una línea de distribución aérea típica. Los resultados fueron comparados con las fórmulas tradicionales para calcular el LEMP como la fórmula de Rubinstein y para calcular tensiones inducidas como la fórmula de Rusck mostrando errores menores al 1%. Si una forma de onda más compleja se usa como la fórmula de Heidler, se encuentran errores menores al 5%. Adicionalmente, la fórmula se empleó para calcular la tasa de fallas de una línea de distribución aérea para terrenos con conductividad finita. Se encontraron errores menores al 5% comparados con las obtenidas en el estándar IEEE 1410. De otro lado, el tiempo de cómputo requerido para la evaluación del desempeño ante rayos de líneas de distribución se reduce a la mitad cuando se usa la fórmula analítica

Spin-orbit and solvent effects in the luminescent [re6q8(ncs)6]4-, q=s, se, te clusters: molecular sensors and molecular devices

Indexación: ScieloRelativistic time-dependent density functional (TDDFT) calculations including spin orbit interactions via the zero order regular approximation (ZORA) and solvent effects using the COSMO model were carried out on the [Re6Q8(NCS)6]4- , (Q = S, Se, Te) clusters. These calculations indicate that the lowest energy allowed electronic transitions are characterized by being of LMCT type. The calculated absorption maximum tends to shift to longer wavelengths as the face-capping chalcogenide ligand becomes heavier. Thus our calculations predict that the [Re6Te8(NCS)6]4- cluster might be also luminescent. Due to the unusual properties exhibited by these and other isoelectronic and isostructural hexarhenium (III) chalcogenide clusters, hexamolybdenum halide clusters and hexatungsten halide clusters, we propose here the design of nanodevices, such as, molecular sensors and molecular nanocells for molecular electronics.http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-97072010000100010&nrm=is

Solitary-wave vortices in quadratic nonlinear media

We find families of vortex solitary waves in bulk quadratic nonlinear media under conditions for second-harmonic generation. We show that the vortex solitary waves are azimuthally unstable and that they decay into sets of stable spatial solitons. We calculate the growth rates of the azimuthal perturbations and show how those affect the pattern of output light. © 1998 Optical Society of AmericaPeer ReviewedPostprint (published version

Melanoma Recognition by Fusing Convolutional Blocks and Dynamic Routing between Capsules

Skin cancer is one of the most common types of cancers in the world, with melanoma being the most lethal form. Automatic melanoma diagnosis from skin images has recently gained attention within the machine learning community, due to the complexity involved. In the past few years, convolutional neural network models have been commonly used to approach this issue. This type of model, however, presents disadvantages that sometimes hamper its application in real-world situations, e.g., the construction of transformation-invariant models and their inability to consider spatial hierarchies between entities within an image. Recently, Dynamic Routing between Capsules architecture (CapsNet) has been proposed to overcome such limitations. This work is aimed at proposing a new architecture which combines convolutional blocks with a customized CapsNet architecture, allowing for the extraction of richer abstract features. This architecture uses high-quality 299×299×3 skin lesion images, and a hyper-tuning of the main parameters is performed in order to ensure effective learning under limited training data. An extensive experimental study on eleven image datasets was conducted where the proposal significantly outperformed several state-of-the-art models. Finally, predictions made by the model were validated through the application of two modern model-agnostic interpretation tools

Electrochemical SERS spectra of isonicotinic acid analyzed under a photoinduced charge-transfer mechanism

Isonicotinic (IN) acid is one of the three monocarboxilic derivatives of pyridine in which the acid group is located in para-position of the heterocyclic ring. It is a weak acid (pK2=4.86) and therefore, it is not completely ionized in neutral aqueous solutions, being the zwitterion and the anion the majority chemical species at neutral pH. In acidic solutions (pK1=1.84) the pyridinic nitrogen atom can be protonated yielding a third chemical species with positive charge [1]. In addition, IN acid shows two functional centres that can interact with the silver metallic surface such as the carboxilate group and the aromatic nitrogen atom. Therefore, the analysis of the SERS spectra of IN has been focused on identifying the chemical species adsorbed on the silver surface and its centre of interaction by considering the participation of a photoinduced charge-transfer (CT) mechanism in each particular SERS record as we have previously detected in the SERS of pyridine derivatives [2]. SERS spectra of the IN acid (5x10-3 M) have been recorded on silver at electrode potentials ranging from 0.00 up to -1.00 V and at different pH by using 0.1 M Na2SO4 aqueous solution as electrolyte. The figure shows the SERS recorded at basic pH. The experimental set up is described elsewhere and the excitation line of 514.5 nm wavelength was used. [2]. The detection of the presence of CT processes, which are similar to resonance Raman, requires to carry out quantum mechanical calculations [2].Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tec

Degradacion de ecosistemas de la palma más austral del mundo (Jubaea Chilensis) acelerada por los fuegos estivales en los cordones litorales de Valparaíso y Viña del Mar (32°50'-33° 02'S). Un caso sostenido de perturbación del paisaje

Jubaed chilensis (Mol) Baillon is the world's southernmost palm tree. It grows as an endemic species in Chile in sporadic forests, between 30° and 37° south, mainly in settings of the coastal mountains of the country's mediterranean zone. The hills around the cities of Valparaiso and Viña del Mar have supported the pressure and the advance of the population, causing strong impacts on the humid sclerophyllous remnants of the plant groups of a century ago. This habitat contained several hundred palm trees that have been disappearing due to multiple effects. The results of a research that started ten years ago to study the regression process of these forests and of the Chilean palrn are presented. Cutting, cattle raising, getting firewood and making charcoal, the advance of housing toward the hills due to the growth of coastal cities, road construction, and the recurrence of forest fires since 1960 have been the most recurrent impacts for the present condition of these ecosystems. On the other hand, the constant exploitation of the palm for its fiuits and the use of its long leaves have affected it greatly. It supported an enormous impact when in 1996 there was much land moving on these slopes to build a highway, eliminating andlor transferring about 500 palms. In 1999 space was made also in that area to build a gas duct for Viña del Mar. This again meant the loss of dozens of palms, and to this day the summer fires continue affecting these palm groves.    Jubaea chilensis (Mol) Baillon es la palma más austral del mundo y se desarrolla como especie endémica de Chile en bosques esporádicos, entre los 30° - 37° sur, principalmente en enclaves de las montañas costeras de la zona mediterránea del país. La colinas periféricas de las ciudades de Valparaíso y Viña del Mar han soportado la presión y el avance de la población, lo cual ha causado fuertes impactos a los bosques esclerófilos húmedos remanentes de las agrupaciones vegetales de hace un siglo atrás. En este hábitat se hallaban varios centenares de palmeras que han ido desapareciendo por múltiples efectos. Se presentan resultados de una investigación iniciada 10 años atrás, para estudiar el proceso de retroceso de estos bosques y de la palma chilena. La tala, la ganadería, la búsqueda de leña y elaboración de carbón, el avance de las viviendas hacia las colinas por el crecimiento de las ciudades costeras, la construcción de caminos y carreteras, y la recurrencia de incendios vegetales desde 1960; han sido los impactos más recurrentes del estado actual de estos ecosistemas. Por otra parte, la explotación constante de la palma por sus frutos y uso de sus largas hojas, la han afectado en gran parte. Soportó un enorme impacto cuando en 1996 hubo grandes movimientos de tierras en estas laderas para construir una autopista, habiéndose eliminado y/o trasladado alrededor de 500 palmas. En 1999 se abrió espacio también en estos lugares para llevar el trazado de un ducto de gas para Viña del Mar. Nuevamente con ello, se perdieron decenas de palmeras y hasta hoy en día, los fuegos vegetales de verano siguen afectando a estos palmares.