Analysis of the Behaviour of Biofuel-Fired Gas Turbine Power Plants

The utilisation of biofuels in gas turbines is a promising alternative to fossil fuels for power generation. It would lead to significant reduction of CO2 emissions using an existing combustion technology, although significant changes seem to be needed and further technological development is necessary. The goal of this work is to perform energy and exergy analyses of the behaviour of gas turbines fired with biogas, ethanol and synthesis gas (bio-syngas), compared with natural gas. The global energy transformation process (i.e. from biomass to electricity) has also been studied. Furthermore, the potential reduction of CO2 emissions attained by the use of biofuels has been determined, considering the restrictions regarding biomass availability. Two different simulation tools have been used to accomplish the aims of this work. The results suggest a high interest and the technical viability of the use of Biomass Integrated Gasification Combined Cycle (BIGCC) systems for large scale power generation

BIM from Concept Design to Fabrication

When an architect ideates a complex building envelope, they often rely on a façade consultancy to develop the final detailed solution of their design. The purpose of this paper is to describe a customised BIM methodology to develop complex building envelopes, evaluating the process followed to convert an architectural concept design to a fabrication reality. Over recent years, building information modelling has developed greatly in terms of architectural, structural and MEP disciplines. It conveniently advances and analyse the variables of a concept design, and furthermore, coordinates disciplines during the detailed design phases. However, when a technical approach to the envelope’s design must be implemented, we need detailed engineering tools to simulate the environmental data, and to analyse and develop the system’s fabrication features and assemblies, which are tedious to incorporate on BIM basis. This paper describes the process followed to develop and execute a building envelope project, starting with a concept design and incorporating virtual simulation processes for the solution to meet its structural and thermal requirements. The final aim is to have detailed drawings and documents of the envelope’s elements, with coordinated information for construction and fabrication purposes

Síntesis y caracterización de nuevas poli (eter ureas) para su aplicación en procesos por reacción e inyección simultáneas (RIM)

En este trabajo se sintetizaron cierto numero de poli(éter/ureas) en las que se variaron la longitud del polieter, el tipo de isocianato, el tipo de extendedor, y la cantidad relativa de estos componentes en la composicion del polimero. Los polimeros resultantes mostraron una morfología de microfases separadas que condicionaron las propiedades del polimero. Las propiedades térmicas demostraron la existencia de un cierto grado de mezcla de fases, y la mejora de la separación de estas con el tratamiento térmico a alta temperatura. Las propiedades dinámicas mostraron también la existencia de cierta mezcla de fases y la buena estabilidad dimensional de estos compuestos a alta temperatura. El análisis termogravimetrico dio información sobre la resistencia a la degradación de los polimeros, que resulto grande, con temperaturas de inicio de degradación sobre los 300 grados c. Esta degradación se encontró que se inicia en los enlaces de urea, que se escinden. El comportamiento mecánico vario desde elastomeros blandos a plásticos rígidos, siendo en general polimeros de alto modulo de young. Las propiedades variaron con el tiempo, mejorando con la mejora de la segregación de fases, que demostró su naturaleza de proceso dinámico

Hydrolytic degradation of poly(ε-caprolactone) with different end groups and poly(ε-caprolactone-co--Y-butyrolactone): characterization and kinetics of hydrocortisone delivery

7 páginas, 8 figuras, 2 tablas.-- El pdf es el borrador del artículo.Asymmetric telechelic alfa-hydroxyl-ω-(carboxylic acid)-poly(ε-caprolactone) (HA-PCL), alfa-hydroxyl-ω-(benzylic ester)-poly(ε-caprolactone) (HBz-PCL), and an asymmetric telechelic copolymer alfa-hydroxyl-ω-(carboxylic acid)-poly(ε-caprolactone-co-Y-butyrolactone) (HA-PCB) were synthesized by ring-opening polymerization of ε-caprolactone (CL). CL and CL/-butyrolactone mixture were used to obtain homopolymers and copolymer respectively at 150°C and 2 hr using ammonium decamolybdate (NH4) [Mo10O34] (Dec) as a catalyst. Water (HA-PCL and HA-PCB) or benzyl alcohol (HBz-PCL) were used as initiators. The three polylactones reached initial molecular weights between 2000 and 3000 Da measured by proton nuclear magnetic resonance (1H-NMR). Compression-molded polylactone caplets were allowed to degrade in 0.5 M aqueous p-toluenesulfonic acid at 37°C and monitored up to 60 days for weight loss behavior. Data showed that the copolymer degraded faster than the PCL homopolymers, and that there was no difference in the weight loss behavior between HA-PCL and HBz-PCL. Caplets of the three polylactones containing 1% (w/w) hydrocortisone were placed in two different buffer systems, pH 5.0 with citrate buffer and pH 7.4 with phosphate buffer at 37°C, and monitored up to 50 days for their release behavior. The release profiles of hydrocortisone presented two stages. The introduction of a second monomer in the polymer chain significantly increased the release rate, the degradation rate for HA-PCB being faster than those for HBz-PCL and HA-PCL. At the pH studied, only slight differences on the liberation profiles were observed. SEM micrographs indicate that hydrolytic degradation occurred mainly by a surface erosion mechanism.The financial support by Consejo Nacional de Ciencia y Tecnología and Universidad de Guanajuato is acknowledged. L.M.O.C. thanks Consejo Nacional de Ciencia y Technología (CONACYT) for a Ph.D. scholarship.Peer reviewe

Hexacoordinated Oligosilanes from a Hexacoordinated Silicon(IV) Complex Containing an O,N,N,O Salen-type and Thiocyanato-N Ligands

8 páginas, 4 figuras, 3 esquemas, 1 tabla.Two new neutral hexacoordinated silicon complexes with SiN4O2 (6) and SiN3O2C (7) coordinating frameworks were synthesized by reaction of the O,N,N,O-donor salen-type ligand 1,2-bis[[(2-hydroxy-4-methoxyphenyl)(phenyl)methylene]amino]ethane (H2salen*) with Si(NCS)4 and HMeSi(NCS)2, respectively. The complexes 6 [Si(salen*)(NCS)2] and 7 [Si(salen*)Me(NCS)] were studied in the solid-state by 29Si and 15N CP/MAS NMR and in solution by 1H, 13C, and 29Si insensitive nuclei enhanced by polarization transfer (INEPT) NMR, UV/vis and FT-IR spectroscopy. Elemental analysis and single-crystal X-ray diffraction analysis were used to confirm the composition and structure for compounds 6 and 7. Both complexes contain the dianionic salen-type ligand coordinated in an equatorial fashion to the silicon center, while the axial positions are occupied by two thiocyanato-N ligands for 6 and one thiocyanato-N and one methyl ligand for 7. Complex 6, which contains two Si−NCS functional groups, was used as monomer to produce a mixture of linear oligosilanes with a hexacoordinated silicon backbone (formulated SCN-[Si(salen*)]n-NCS, n = 2−8) 8, via a Wurtz-type coupling reaction. Oligomers 8 were identified by solid-state 29Si cross polarization-magic angle spinning NMR and solution 1H and 29Si NMR spectroscopy, matrix assisted laser desorption ionization-time of flight (MALDI-TOF), gel-permeation chromatography (GPC), FT-IR, UV/vis spectroscopy and thermogravimetric analysis (TGA). Conclusive evidence of the oligomeric nature of 8 was provided by MALDI-TOF spectrometry and was supported by quantitative solution 29Si NMR and GPC studies.Financial support for this work was provided by the Mexican Department of Public Education (PROMEP-SEP). G.G.G. thanks the Mexican National Council for Science and Technology (Conacyt) for a PhD scholarship.Peer reviewe

Construcción y calibración de un equipo para la medición de carbonato de calcio

Se construye un calcímetro de lectura directa y de fácil manipulación que permite determinar con un error menor al 1 % el contenido de carbonato de calcio en rocas y sedimentos. Se utiliza un manómetro de 1 bar de presión y el cuerpo se construye con material acrílico. Se realiza la calibración del equipo utilizando carbonato de calcio puro y calcita de alta pureza comprobada mediante la difracción de rayos X.An easy to use direct reading calcium carbonate measuring device, is built to determine, with an error smaller than 1 %, the content of that mineral in rocks and soils. A gauge of 1 bar pressure is used and the device body is built in acrylic material. The calibration is carried out using pure calcium carbonate and calcite of high proven purity corroborated by means of diffraction X-ray.Asociación Argentina de Geofísicos y Geodesta

Bullying in Adolescents Practising Sport: A Structural Model Approach

This article aims to analyse the relationship between the bullying aggressor and bullying victim profile related to practising or not practising sport in adolescents living in southern Spain. The research includes male and female participants aged between 12 and 16 years in different secondary schools in the provinces of Andalusia, Ceuta and Melilla in the period between February 2022 and June 2022. The study aims to extend the existing scientific, theoretical and empirical knowledge on the influence of playing sport or not on disruptive bullying attitudes in adolescents. To this end, two initial hypotheses were designed; the first hypothesises that bullying victim behaviours are associated with future bullying aggressor behaviours when practising sport; and the second states that victim behaviours are associated with future bullying aggressor behaviours when not practising sport. To verify them, SPSS software was used for the preliminary analysis of the scale and sociodemographic profile. Additionally, the study is based on structural equation modelling methodology and variance-based methods employing SmartPLS v3.3 software. The results show the importance of sport or physical activity to reduce the chances of carrying out bullying actions on other peers and/or classmates. Therefore, it is considered necessary to prevent bullying in the classroom by implementing sports intervention programmes in educational centres

First records of non-indigenous Timarete caribous (Grube, 1859) (Polychaeta; Cirratulidae) in the Western Mediterranean, and its ecology in the Mar Menor (Murcia, SE Spain)

The knowledge and control of invasive species are essential in the management of marine ecosystems. The Mediterranean Sea is one of the marine areas with the highest number of invasive species detected, most of them invertebrates. On a smaller scale, colonization by non-native species in coastal lagoons depends directly on their connectivity with the adjacent sea and on the changes in their environmental conditions induced mainly by human interventions. In this study, the cirratulid species Timarete caribous Grube, 1859, native from the Western and Central Atlantic Ocean, was detected for the first time in a Western Mediterranean coastal lagoon, the Mar Menor. It has been found in dense aggregates on both artificial and natural rocky substrates, mainly in the most important communication channel with the Mediterranean Sea. Following the evolution of this NIS will be important for understanding the dynamic and spread of the species and its possible effects on the indigenous biological communitie

Hyper-Cross-Linked Porous Polymer Featuring B−N Covalent Bonds (HCP-BNs): A Stable and Efficient Metal-Free Heterogeneous Photocatalyst

The first example of a porous polymer containing B-Ncovalentbonds, prepared from a tetraphene B-N monomer and biphenylas a comonomer, is reported. It was prepared using the solvent knittingstrategy, which allows the connection between the aromatic rings ofthe two monomers through methylene groups provided by an externalcross-linking agent. The new polymer exhibited micromeso porositywith an S (BET) of 612 m(2)/g, highthermal stability, and potential properties as a heterogeneous photocatalyst,since it is very active in the aza-Henry coupling reaction (>98%ofconversion and selectivity). After the first run, the catalyst improvesits photocatalytic activity, shortening the reaction time to only2 h and maintaining this activity in successive runs. The presenceof a radical in this structure that remains stable with successiveruns makes it a new type of material with potential applications asa highly stable and efficient photocatalyst.Ministerio de Ciencia e InnovaciónComunidad de Madri

Polymeric films based on blends of 6FDA-6FpDA polyimide plus several copolyfluorenes for CO2 separation

Producción CientíficaThree emitting copolyfluorenes, based on 2,7-(9,9-dihexyl)fluorene and different aryl groups (1,4-bencene, PFH-B; 1,4-bencen-1,2,5-thiadiazole PFH-BT; 1,4-naphthalen- 1,2,5-thiadiazole, PFH-NT), showing diverse acceptor character, in different proportions were blended with a polyimide 6FDA-6FpDA to make a series of films. These copolyfluorene-polyimide blends were prepared and characterized in solid state, using several techniques. The fluorescence of conjugated polymers can be used as a tool to understand the formation of the membrane and also to increase permeability and selectivity in comparison to films without fluorescence. The relationship between the intrinsic fluorescence of conjugated polyfluorenes and their gas separation properties has been explored in order to establish the influence of the composition and the nature of the aryl group, in the conjugated polymer, on the gas separation performances. In all cases, a low proportion of copolyfluorenes (< 1%weight) gives better CO2/CH4 permselectivity properties than the original pure polyimide matrix. The best results were found for the samples that contain PFH-NT. This sample gives 25 % increase in the CO2 permeability with 15 % increase in CO2/CH4 selectivity. Finally, the loss of efficiency in conjugation mechanisms of absorption and emission of the samples could be explained on the basis of the π-staking of the polymer chains produced when a certain low percentage of conjugated polymers in the blend is surpassed. When this π- staking starts, gas permeation properties start to decline too.Junta de Castilla y León (programa de apoyo a proyectos de investigación – Ref. VA302U13