1,652 research outputs found
Dryopteris × orexpansa, un nuevo híbrido y D. × deweberi en Cantabria
Se describe un nuevo híbrido en Cantabria Dryopteris × orexpansa.
Se presenta su citología y se estudian los caracteres morfológicos y micromorfológicos
con el fin de establecer sus posibles parentales: D. oreades y D. expansa. Por otro lado
se cita por primera vez en Cantabria, Dryopteris × deweveri.Se hacen algunas consideraciones
sobre su distribución en la Península Ibérica y se proporciona información para
su identificación
Dos nuevos híbridos de Dryopteris guanchica: D. × cantabrica y D. × ronald-vianensis
Se describen dos nuevos híbridos en Cantabria: Dryopteris × cantabrica y D. × ronald-vianensis. Se respaldan las propuestas sobre sus orígenes, mediante el estudio de
los caracteres morfológicos y micromorfológicos, así como citogenéticos. Se implica en el
origen del primero a D. corleyi y a D. guanchica; mientras que en el segundo se postulan como presumibles parentales a D. dilatata y a D. guanchica. Además se estudia D. × gomerica y se compara con los híbridos propuestos. Se extiende el área de distribución de D. guanchica hasta Cantabria.Two new hybrids are described in Cantabria: Dryopteris × cantabrica and D. × ronald-vianensis. Hypotheses about their origins are supported by morphological, micromorphological and cytogenetic features. D. corleyi and D. guanchica are involved in the origin of the former whereas. D. dilatata and a D. guanchica are presented as presumable parents of the latter. Furthermore D. × gomerica is studied and compared with the proposed hybrids. The geographic distribution of D. guanchica is expanded to Cantabria
Energy consumption in university commuting: Barriers, policies and reduction scenarios in León (Spain)
.There is a growing interest in university commuting that aims at identifying patterns of behavior, as well as the main barriers limiting the advances in sustainable mobility on campus. This work analyzes, on the basis of an online survey conducted at the University of Leon (ULE), the following issues: a) the behavior of ULE users in their weekly commuting; b) the environmental implications of such behavior in terms of non-renewable cumulative energy demand (NR CED), and c) the main barriers/disincentives to implementing a modal shift as declared by the respondents, according to their work status (students or workers) and gender. The data reveal differences in habits, especially in relation to the users’ work status, while differences by gender are not so significant. Still, this case study shows how men students use bicycles and motorcycles slightly more often than women, while the car is the main transportation mode for women workers. Car use is in fact the main hotspot of university commuting to the ULE (approximately 95% of the NR CED). Unsafe cycle paths, thefts at university, bus fares and frequency of service were the main barriers to a greater use of bicycle and bus identified by the survey respondents, with some differences by gender and work status. Measures aimed at minimizing these barriers could achieve maximum reductions of the NR CED ranging between 18.1% and 35.0%. This article discusses measures and policies that could be implemented to improve sustainable mobility at university.S
Hydrothermal multivariable approach. Full-scale feasibility study
A process configuration combining thermal hydrolysis (TH) and anaerobic digestion (AD) of sludge has been studied with the objective of analysing the feasibility of the technology for full scale installations. The study has been performed through pilot scale experiments and energy integration considerations, and a scheme of the most profitable option is presented: thermal hydrolysis unit fed with 7% total solids (TS) secondary sludge, anaerobic digestion of the hydrolysed sludge together with fresh primary sludge, and a cogeneration unit to produce green electricity and provide hot steam for the thermal hydrolysis process. From a technical and practical point of view, the process scheme proposed is considered to be feasible. Based on the results of the pilot plant performance and the laboratory studies, the process has proven to operate successfully at a concentration of 7-8% TS. After the thermal hydrolysis, sludge viscosity becomes radically smaller, and this favours the digesters mixing and performance (40% more biogas can be obtained in nearly half the residence time compared to the conventional digestion). From an economic point of view, the key factors in the energy balance are: the recovery of heat from hot streams, and the concentration of sludge. The article presents the main energy integration schemes and defines the most profitable one: an energetically self-sufficient process, with a cogeneration unit. The scheme proposed has proven to need no additional energy input for the sludge hydrolysis, generates more that 1 MW green electricity (246 kW surplus with respect to the conventional process), and produces 58% less volume of Class A biowaste. The study and balances here presented set the basis for the scale-up to a demonstration plant (hydrolysis + anaerobic digestion + cogeneration unit)
A Follow-Up Study of Cognitive Development in Low Risk Preterm Children
The results of a longitudinal study on the cognitive development of one group of full-term and three groups of low risk preterm children with different gestational ages (GA) are presented. The 181 participants were divided into four GA groups of similar size. The aims were: 1) To check if there are differences in cognitive development (measured through the Batelle scale) among the GA groups. 2) To establish the predictive factors of cognitive development at 22 and 60 months of age, taking into account biomedical, environmental and individual factors. The results of the repeated measures ANOVA performed at 22 and 60 months of age indicated that the cognitive trajectories of the four GA groups were similar. Linear regression analyses showed that the effect of the different predictors changed in relation to the time of measurement of cognitive development. Biological factors and the quality of home environment had a moderate effect on the cognitive development at 22 months of age. Cognitive results obtained at 22 months of age, and, to a lesser extent, working memory had the greatest effect on cognitive development at 60 months. GA does not predict cognitive development. Preterm children do not show cognitive delay if they are healthyThis research was funded by the Ministerio de Ciencia e Innovación of the Spanish Government, grants number PSI2008-03905, PSI2011-23210 and PSI2015-66697-R to the first authorS
Worldwide Research Trends on Solar-Driven Water Disinfection
“Ensure access to water for all”, states Goal 6 of the UN’s Sustainable Development Goals. This worldwide challenge requires identifying the best water disinfection method for each scenario. Traditional methods have limitations, which include low effectiveness towards certain pathogens and the formation of disinfection byproducts. Solar-driven methods, such as solar water disinfection (SODIS) or solar photocatalysis, are novel, effective, and financially and environmentally sustainable alternatives. We have conducted a critical study of publications in the field of water disinfection using solar energy and, hereby, present the first bibliometric analysis of scientific literature from Elsevier’s Scopus database within the last 20 years. Results show that in this area of growing interest USA, Spain, and China are the most productive countries in terms of publishing, yet Europe hosts the most highly recognized research groups, i.e., Spain, Switzerland, Ireland, and UK. We have also reviewed the journals in which researchers mostly publish and, using a systematic approach to determine the actual research trends and gaps, we have analyzed the capacity of these publications to answer key research questions, pinpointing six clusters of keywords in relation to the main research challenges, open areas, and new applications that lie ahead. Most publications focused on SODIS and photocatalytic nanomaterials, while a limited number focused on ensuring adequate water disinfection levels, testing regulated microbial indicators and emerging pathogens, and real-world applications, which include complex matrices, large scale processes, and exhaustive cost evaluation
Nutrient release through litterfall in short rotation poplar crops in mediterranean marginal land
Producción CientíficaA detailed knowledge of how poplar leaf litter decomposes under Mediterranean marginal conditions can help to minimize fertilization inputs and determine the profitability and sustainability of energy crops established in these particularly sensitive areas for bioenergy. Leaf litter decomposition was monitored for 32 months using the litterbag technique in a poplar crop under short rotation conditions in a marginal Mediterranean area. In addition, nutrient dynamics, together with the production and composition of the woody and foliar biomass produced, were studied for a period of four years. Leaf litter decomposition was relatively slow, particularly during the winter months, and accelerated in early spring, coinciding with the rainy season. At the end of the decomposition study 50% of the initial litterfall was decomposed, releasing roughly 60% of the N, 40% of the K, and 70% of the P initially present in fresh leaves. Annual yields of 6.0 dry Mg ha−1 were obtained. The aerial biomass produced the first year of the second rotation cycle extracted 83, 8.7, and 29 kg ha−1 of N, P, and K, respectively, whereas the amount of nutrients that were estimated to be naturally supplied to the system through leaf litter decomposition were 180 kg ha−1 of N, 19 kg ha−1 of P, and 30 kg ha−1 of K. Therefore, four years after establishing the energy crop, leaf litter was able to release higher amounts of primary macronutrients into the environment than the nutrient uptake by the produced aboveground biomass (woody and foliar biomass).Ministerio de Educación y Ciencia de España - FEDER (PS-120000-2005-6
Deducciones de índole paleoterapéutica en el estudio de huesos largos fracturados de aborígenes canarios
La evidencia paleopatológica de lesiones traumáticas del aparato locomotor
en hombres prehistóricos nos ha proporcionado, aparte de otro tipo
de información, una serie de datos que son un reflejo de las condiciones que
han concurrido sobre un hueso fracturado en vías de consolidación. El
hallazgo, tanto de fracturas correctamente consolidadas, como de secuelas
postraumáticas tales como deformidades angulares, acortamiento, sinostosis,
miositis osificante traumática, etc., permite, en un buen número de
casos, hacer deducciones de índole terapéutica
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