Energy consumption and intensity of toll highway transport in Spain

We estimate the energy consumption of toll highway transport on a number of Spanish roads. Regression parameters are balanced according to coefficients from an empirical analysis based on survey data by vehicle type. The mean energy consumption and subsequent CO2 emissions on the toll highway sections are estimated as 1895 MJ/h/lane-km and 0.15 tCO2 eq./h/lane-km, values that increase to 2644 and 0.22 when energy and carbon emissions of transport infrastructure are considered based on the life cycle energy consumption for toll highway construction and use. If the energy intensity of infrastructure construction is allocated to the users according to traffic, it is much higher for motorcycles than for cars, and is significantly lower for articulated trucks than for vans

CARACTERIZACIÓN DE ZONAS AFECTADAS POR EL AGENTE CAUSAL DE LA CAIDA FOLIAR DE PINO EN PUEBLA, MÉXICO

Puebla is a biodiverse state located in the central part of México, characterized by having broad heterogeneity of altitudes with extensive diversity in climates and types of vegetation, with predominance of conifer and red oak forests. During 2011, defoliations were detected in different pine species in the Sierra Norte region of Puebla, so that the characteristics presented by the sites affected by the pine litter fall were defined with the purpose of contributing to decision making in management plans. Likewise, the climate conditions of the sites affected from 2011 to 2014 were characterized, finding that the sites facing south, with slopes of between 24 % and 87 %, altitudinal distribution between 1969 and 2835 m, were the ones with greatest affectation, finding Pinus pseudostrobus as the species with highest litter fall.Puebla es un estado biodiverso ubicado en la parte central de México, se caracteriza por tener una amplia heterogeneidad de altitudes con extensa diversidad de climas y tipos de vegetación, predominando los bosques de coníferas y encino. Durante 2011 se detectaron defoliaciones en diferentes especies de pino en la región de la Sierra Norte de Puebla, por lo que se determinaron las características que presentan los sitios afectados por la caída foliar del pino con la finalidad de contribuir a la toma de decisiones en los planes de manejo. Asimismo, se caracterizaron las condiciones climáticas de los sitios afectados del 2011 al 2014, determinando que los sitios con exposición al sur, con pendientes de entre 24% y 87%, distribución altitudinal entre 1969 y 2835 m fueron los de mayor afectación, registrando a Pinus pseudostrobus con la de mayor caída de hojas

DISTRIBUCIÓN DEL Abies religiosa (Kunth) Schltdl. & Cham. BAJO ESCENARIOS DE CAMBIO CLIMÁTICO EN EL EJE NEOVOLCÁNICO, MÉXICO

The sacred fir (Abies religiosa) is a species of high mountain temperate climate, found in the central states of México. The species serves as shelter for the monarch butterfly, which travels from the United States and Canada, and therefore has ecological importance. The current potential distribution of the sacred fir forests was determined, as well as under scenarios of climate change (CC), in the Transversal Neovolcanic Axis. The distribution models were obtained by applying the GARP algorithm in combination with climate, topographic, vegetation, soil coverages, and points of presence of the species. According to the results, the current potential distribution area of the sacred fir is concentrated mostly in the states of Estado de México, Morelos, Michoacán, Querétaro, Ciudad de México and Puebla with 5,190,902 ha. The possible distribution under scenarios of CC RCP4.5 for the year 2039 would be 8,060,023.10 ha, essentially in Hidalgo, Estado de México, Morelos, Michoacán, Querétaro and Ciudad de México. The results suggest a potential increase in the species distribution under the current scenarios and with CC.El oyamel (Abies religiosa) es una especie de clima templado de altas montañas, localizado en estados centrales de México. La especie sirve de alojamiento de la mariposa monarca, que proviene de Estados Unidos y Canadá, y por ello su importancia ecológica. Se determinó la distribución potencial actual y bajo escenarios de cambio climático (CC) de los bosques de oyamel en el Eje Neovolcánico Transversal. Los modelos de distribución se obtuvieron aplicando el algoritmo GARP en combinación con coberturas climáticas, topográficas, de vegetación, edafológicas y puntos de presencia de la especie. De acuerdo a los resultados, el área de distribución potencial actual del oyamel se concentra principalmente en los estados de México, Morelos, Michoacán, Querétaro, Ciudad de México y Puebla con 5,190,902 ha. La posible distribución bajo escenarios de CC RCP4.5 para el año 2039 sería de 8,060,023.10 ha, esencialmente en Hidalgo, Estado de México, Morelos, Michoacán, Querétaro y Ciudad de México. Los resultados sugieren un incremento potencial de la distribución de la especie en los escenarios actuales y con CC

Detection of a multi-shell planetary nebula around the hot subdwarf O-type star 2MASS J19310888+4324577

(Abridged) The origin of hot subdwarf O-type stars (sdOs) remains unclear since their discovery in 1947. Among others, a post-Asymptotic Giant Branch (post-AGB) origin is possible for a fraction of sdOs. We are involved in a comprehensive ongoing study to search for and to analyze planetary nebulae (PNe) around sdOs with the aim of establishing the fraction and properties of sdOs with a post-AGB origin. We use deep Halpha and [OIII] images of sdOs to detect nebular emission and intermediate resolution, long-slit optical spectroscopy of the detected nebulae and their sdO central stars. These data are complemented with other observations for further analysis of the detected nebulae. We report the detection of an extremely faint, complex PN around 2MASS J19310888+4324577 (2M1931+4324), a star classified as sdO in a binary system. The PN shows a bipolar and an elliptical shell, whose major axes are oriented perpendicular to each other, and high-excitation structures outside the two shells. WISE archive images show faint, extended emission at 12 and 22 microns in the inner nebular regions. The internal nebular kinematics is consistent with a bipolar and a cylindrical/ellipsoidal shell, in both cases with the main axis mainly perpendicular to the line of sight. The nebular spectrum only exhibits Halpha, Hbeta and [OIII]4959,5007 emission lines, but suggests a very low-excitation ([OIII]/Hbeta = 1.5), in strong contrast with the absence of low-excitation emission lines. The spectrum of 2M1931+4324 presents narrow, ionized helium absorptions that confirm the previous sdO classification and suggest an effective temperature >= 60000 K. The binary nature of 2M1931+4324, its association with a complex PN, and several properties of the system provide strong support for the idea that binary central stars are a crucial ingredient in the formation of complex PNe.Comment: 8 pages, 7 figures, accepted in Astronomy and Astrophysic

Synthesis and Characterization of a Coagulating Agent from Plantain Peel Starch (Musa paradisiaca), as Coadjuvant in Water Treatment

Coagulation processes are widely used for water treatment, mainly with chemical coagulants. In this research, starch derived from a waste (unripe plantain peel, Musa paradisiaca) was used as a starting point for a chemical modifcation. Through acetylation, its chemical structure was modifed and characterized by infrared spectrophotometry, for its evaluation as a coadjuvant in coagulation operations to reduce the turbidity of raw water. Two experimental designs were developed to evaluate the incidence of modifed starch as the main coagulant, or in conjunction with a conventional coagulant (Al2(SO4)3), at diferent (Al2(SO4)3)/acetylated starch ratios, in jar-test experiments. In the frst experimental design, with the acetylated starch as the main coagulant, turbidity removal percentages reached 47.93% (average value, 41.18%). For the (Al2(SO4)3)/acetylated starch coagulation process, 98.91% turbidity removal was reached in the second experimental design (average value, 97.16%). The impact of starch chemical substitution degree and the (Al2(SO4)3)/acetylated starch ratio on the fnal turbidity obtained in the jar-tests was determined using ANOVA test. There was a great infuence of the chemical substitution degree and the concentration of acetylated starch utilized, when modifed starch was used as the main coagulant. For the second experimental design, the (Al2(SO4)3)/acetylated starch ratio had a greater incidence on the turbidity removal. Thus, modifed starch obtained from plantain peel waste is a promising coadjuvant material for water coagulation processes

Chemists’ knowledge object. Formulation, modification and abandonment of iconic model

This article presents an analysis of different perspectives in regards to chemistry scientific statute. The category of scientific model was considered to characterize the proposal and development of technological-iconic model. It was necessary to have a look at the time in which the introduction of analogical and symbolic models was indispensable to modify the initial model. It also established the way in which the technological-iconic model can be a didactic foundation to lead secondary students towards Chemistry as one of the natural sciences

Desarrollo científico en Colombia: una revisión de las revistas científicas especializadas en ciencias de la naturaleza. 19501999

El presente artículo se deriva de la realización de un proyecto de investigación, dentro de la línea de “Historia social de las ciencias y de la educación en ciencias”. Con base en la metodología suministrada por la cienciometría y bibliometría, se examinaron las publicaciones de científicos colombianos en las revistas internacionales “Journal of the American Chemical Society”, en el “American Journal of Physics”, en “The Journal of Experimental Biology”, y en las nacionales “Revista Colombiana de Química”, “Revista Colombiana de Física” y “Actualidades Biológicas”. Hechos los análisis documentales comparativos, la conclusión es que durante el período señalado, no se puede afirmar que en el país se haya organizado una comunidad científica

Prevalencia de la brucelosis humana, en hatos bovinos infectados y en mataderos del Departamento del Valle del Cauca.

Ganadería bovin