THEORETICAL ASSESSMENT OF A STIRLING ENGINE 'AMAZON' BY USING PROSA AND MATHCAD

This study describes how to build a prototype Stirling engine named Amazon, focusing on how to apply it to generate electric power in remote areas, with an expected power of 8 kW. Such engine was assessed theoretically by using two different computer software, i.e. PROSA and 'a model to simulate Stirling engines by the theory of Schmidt', which was formulated in Mathcad. The results from Mathcad software were on average 6.8% higher than the results from PROSA software. Such fact occurs since Mathcad does not consider the losses in a real system. Hence, the PROSA is generally more accurate in its results. Modeling performed in Mathcad presents higher values for partial loads and similar values for the project operating point

The representation of coupling interactions in the Material Properties Open Database (MPOD)

International audience; The Material Properties Open Database (MPOD, http//mpod.cimav.edu.mx) is a functional element of the web-based open databases system linked with crystallography. MPOD delivers single-crystal tensor properties in several representations, ranging from numerical matrices to 3D printing. Longitudinal moduli surfaces can be displayed in computers as well as in smart cell phones. Properties are stored as '.mpod' files. IUCr formatting standards (CIF) are followed. The original published paper containing the data is cited. Structural and experimental information is also registered and linked. 'Coupling properties', say piezo-effects and magnetoelectricity, represent interactions linking different subsystems in a material. Currently, piezoelectricity occupies a significant fraction of cases in MPOD. The implications of crystal symmetry in piezoelectricity are systematically taken into account. Matrices' elements and longitudinal moduli surfaces are checked for consistency with the Neumann principle. The inclusion of magnetoelectric axial tensors introduces exciting features into MPOD

Optimization of the properties of poplar and willow chemimechanical pulps by a mixture design of juvenile and mature wood

Forest plantations of Salicaceae (poplars and willows) in Argentina are mainly used for the manufacture of pulp for newsprint. The rapid growth of these species results in a decrease in rotation age, which increases the proportion of juvenile wood. The aim of this work was to define the proportions of juvenile wood (JW) and mature wood (MW) of these species that can optimize the mechanical and optical properties of chemimechanical pulps for newsprint production. A two-component mixture type experimental design was used with proportions (JW:MW) of 0:100%, 25:75%, 50:50%, 75:25%, and 100:0%. When the mechanical properties were optimized, the highest desirability function was obtained with a JW:MW ratio of 100:0%, and the optimal ratio for optical properties was 0:100%. The pattern of variation of mechanical properties can be attributed to the higher density of MW, whilst that of the optical properties can be attributed to the higher content of extractives in the JW.Facultad de Ciencias Agrarias y Forestale

Removal of Di-(2-ethylhexyl)phthalate (DEHP) from water using a LECA-Pseudomonas putida Biobarrier

The removal and biodegradation of an organic toxic pollutant, di-(2-ethylhexyl) phthalate (DEHP), has been investigated. Initially, a screening of different degrading bacteria has been developed and Pseudomonas putida showed the highest degradation ability. This bacterium was immobilised in an inert support, light expanded clay aggregate (LECA). After the biofilm formation on the LECA, the degradation of DEHP was evaluated operating in a fixed bed reactor. In addition, several studies of DEHP adsorption on LECA were carried out in order to determine the mechanism of the degradation process that takes place. The degradation studies demonstrated that the developed system can be applied to DEHP removal and the degradation is due to adsorption process and the activity of P. putida

Heartwood and physical properties of Robinia pseudoacacia wood in relation with the potential use in solid wood products

A fin de caracterizar tecnológicamente la madera de Robinia pseudoacacia L. “acacia blanca” del centro-norte de la provincia de Buenos Aires-Argentina, en relación a su potencial uso en la industria de la madera sólida, los objetivos del trabajo fueron determinar las propiedades físicas de la madera (densidad, contenido de humedad y cambios dimensionales), y el contenido de duramen a lo largo del fuste comercial. Se cortaron rodajas a 4 alturas en el fuste (0,3 m; 1,3m; 2,3m y 4m a partir del suelo) en 10 árboles (7-15 años) implantados en Chivilcoy, Provincia de Buenos Aires. Sobre cada rodaja se midieron el diámetro sin corteza, el diámetro del duramen y se determinó la densidad normal12%. La densidad mostró homogeneidad a lo largo del fuste comercial, con un rango de magnitud que la clasifica como madera semi-pesada (0,750 y 0,823 g/cm3). Esta homogeneidad, junto con la buena estabilidad dimensional (T/R 1,42) y los altos valores de duramen (59%) hallados en las diferentes alturas del fuste, permitiría considerar a esta madera apta para aplicaciones al exterior, tanto para madera redonda como madera aserrada, pudiendo utilizarse para pisos, muebles, pérgolas, revestimientos.In order to characterize Robinia pseudoacacia L. “Black locus” wood from Buenos Aires-Argentina in relation with the potential use in solid wood products, the aims of the work were to determine the physical properties of the wood (density, moisture content and dimensional changes), and the content of heartwood along the stem. Slices were cut at 4 heights in the trunk (0.3 m, 1.3 m, 2.3 m and 4 m from the ground) in 10 trees (7-15 years old) implanted in Chivilcoy, Province of Buenos Aires. On each slice, the diameter without bark and the diameter of the heartwood were measured and the normal density12% was determined. The density showed homogeneity values along the commercial shaft, with a range of magnitude that classified as semi-heavy wood (0,750 - 0,823 g/cm3). This homogeneity, together with the good dimensional stability (T / R 1.42) and the high values of heartwood (59%) found in the different heights of the stem, would allow to consider this wood suitable for outdoor applications, both for round wood such as lumber, and can be used for floors, furniture, pergolas, coverings

Chitosan impregnated gutta-percha points: antimicrobial in vitro evaluation and mechanical properties

Chitosan-impregnated gutta-percha points (ChitGPP) were tested for their ability to inhibit the growth of microorganisms usually involved in root canal infections. Their mechanical properties were also studied and compared with the commonly used commercial points in endodontics. ChitGPP were more efficient in reducing the microbial load than those without chitosan. ChitGPP also possess better tensile and elastic properties than commercial ones. After six months of storage, ChitGPP’s were still able to reduce the bacterial load by 1 log, suggesting that impregnation of gutta-percha points with chitosan could be a good alternative to obtain gutta-percha points with improved antimicrobial properties.info:eu-repo/semantics/publishedVersio