660 research outputs found

    Thermal Perception in Mild Climate: Adaptive Thermal Models for Schools

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    A comprehensive assessment of indoor environmental conditions is performed on a representative sample of classrooms in schools across southern Spain (Mediterranean climate) to evaluate the thermal comfort level, thermal perception and preference, and the relationship with HVAC systems, with a comparison of seasons and personal clothing. Almost fifty classrooms were studied and around one thousand pool-surveys distributed among their occupants, aged 12 to 17. These measurements were performed during spring, autumn, and winter, considered the most representative periods of use for schools. A new proposed protocol has been developed for the collection and subsequent analysis of data, applying thermal comfort indicators and using the most frequent predictive models, rational (RTC) and adaptive (ATC), for comparison. Cooling is not provided in any of the rooms and natural ventilation is found in most of the spaces during midseasons. Despite the existence of a general heating service in almost all classrooms in the cold period, the use of mechanical ventilation is limited. Heating did not usually provide standard set-point temperatures. However, this did not lead to widespread complaints, as occupants perceive the thermal environment as neutral—varying greatly between users—and show a preference for slightly colder environments. Comparison of these thermal comfort votes and the thermal comfort indicators used showed a better fit of thermal preference over thermal sensation and more reliable results when using regional ATC indicators than the ASHRAE adaptive model. This highlights the significance of inhabitants’ actual thermal perception. These findings provide useful insight for a more accurate design of this type of building, as well as a suitable tool for the improvement of existing spaces, improving the conditions for both comfort and wellbeing in these spaces, as well as providing a better fit of energy use for actual comfort conditions

    CO2 Concentration and Occupants’ Symptoms in Naturally Ventilated Schools in Mediterranean Climate

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    A large part of the school building stock in Andalusia lacks ventilation facilities, so that the air renewal of the classrooms is achieved through the building envelope (air infiltration) or the opening of windows. This research analyses the airtightness of the classrooms in Andalusia and the evolution of CO2 concentration during school hours through in situ monitoring. Pressurization and depressurization tests were performed in 42 classrooms and CO2 concentration was measured in two di erent periods, winter and midseason, to study the impact of the di erent levels of aperture of windows. About 917 students (11–17 years of age) were surveyed on symptoms and e ects on their health. The mean n50 values are about 7 h-1, whereas the average CO2 concentration values are about 1878 ppm, with 42% of the case studies displaying concentrations above 2000 ppm with windows closed

    The timely overestimation of Spanish GDP in the great recession

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    The inefficient institutional design of the Euro allowed guaranteed bank liabilities to be converted into government debt, deepening the Great-Recession in Southern European countries. A recessive feedback process occurred through an increase in sovereign debt risk premiums in a cycle of global risk aversion. However, there was one fact that limited these negative effects. We refer to the overestimation of Spanish gross domestic product (GDP) in the public accounts for the period 2007–2013. We quantified the unexplained overestimation of Spain’s GDP for the period 2007–2013 using three different methodologies, which leads us to a similar conclusion: Spain’s GDP was overestimated by between 17% and 18%. We demonstrate that this overestimation allowed for significant savings in interest payments through a lower risk premium. This overestimation, unknown to investors, shows that markets are not efficient, and that information is incomplete. It is necessary to understand the role of debt under Hyman Minsky financial instability hypothesis

    Road environment modeling using robust perspective analysis and recursive Bayesian segmentation

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    Recently, vision-based advanced driver-assistance systems (ADAS) have received a new increased interest to enhance driving safety. In particular, due to its high performance–cost ratio, mono-camera systems are arising as the main focus of this field of work. In this paper we present a novel on-board road modeling and vehicle detection system, which is a part of the result of the European I-WAY project. The system relies on a robust estimation of the perspective of the scene, which adapts to the dynamics of the vehicle and generates a stabilized rectified image of the road plane. This rectified plane is used by a recursive Bayesian classi- fier, which classifies pixels as belonging to different classes corresponding to the elements of interest of the scenario. This stage works as an intermediate layer that isolates subsequent modules since it absorbs the inherent variability of the scene. The system has been tested on-road, in different scenarios, including varied illumination and adverse weather conditions, and the results have been proved to be remarkable even for such complex scenarios

    Capeamento, incisão na base do ramo e uso do ácido indolbutírico na propagação vegetativa do guaranazeiro (Paullinia cupana Var. Sorbilis (Mart.) Ducke).

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    O guaraná se destaca como um dos produtos de alto potencial econômico e de grande significado social no meio rural amazônico. O guaranazeiro pode ser propagado por sementes e por estacas. A propagação por sementes tem o inconveniente de obter uma grande variabilidade de plantas no campo. A utilização da propagação vegetativa,propiciando a manutenção das características da planta-matriz, possibilita a produção de exemplares padronizados de alta qualidade. Este trabalho teve como objetivo avaliar o potencial de propagação vegetativa do guaranazeiro (Paullinia cupana var. sorbilis(Mart.)Ducke) por meio das técnicas de capeamento e anelamento, além da aplicação do hormônio indutor de crescimento sobre o enraizamento de estacas. Os cultivares selecionados foram BRS CG882 e CMU 381 que apresentam alta produtividade e baixo nível de enraizamento. O delineamento experimental foi inteiramente ao acaso, em arranjo fatorial 2 x 2 x 2, correspondendo às duas técnicas aplicadas nos ramos, 2 cultivares de guaraná, e a aplicação ou ausência do hormônio, com 3 repetições e 10 estacas por unidade experimental. Após 60 dias da instalação dos tratamentos nas plantas matrizes os ramos foram cortados para a confecção das estacas no viveiro, onde permaneceram por 90 dias sob nebulização intermitente e 50% de irradiância. A aplicação de AIB (2.000 mg.kg-1)aumentou o número de estacas enraizadas. O percentual de estacas mortas não diferiu entre os três tratamentos na ausência de AIB, no entanto, quando se aplicou o hormônio houve redução desse percentual tanto para estacas de ramos capeados quanto para as de ramos anelados. O tratamento com capeamento dos ramos e aplicação de AIB foi o que apresentou maiores valores médios de número de raízes (21,81); comprimento das raízes(6,86 cm) e peso da matéria seca das raízes (4,20 g planta-1)

    A Multi-wavelength analysis of M81: insight on the nature of Arp's loop

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    Context: The optical ring like structure detected by Arp (1965) around M81 (commonly referenced as "Arp's loop") represents one of the most spectacular feature observed in nearby galaxies. Arp's loop is commonly interpreted as a tail resulting from the tidal interaction between M81 and M82. However, since its discovery the nature of this feature has remained controversial. Aims: Our primary purpose was to identify the sources of optical and infrared emission observed in Arp's loop. Methods: The morphology of the Arp's loop has been investigated with deep wide-field optical images. We also measured its colors using IRAS and Spitzer-MIPS infrared images and compared them with those of the disk of M81 and Galactic dust cirrus that fills the area where M81 is located. Results: Optical images reveal that this peculiar object has a filamentary structure characterized by many dust features overlapping M81's field. The ratios of far-infrared fluxes and the estimated dust-to-gas ratios indicate the infrared emission of Arp's loop is dominated by the contribution of cold dust that is most likely from Galactic cirrus. Conclusions: The above results suggest that the light observed at optical wavelengths is a combination of emission from i) a few recent star forming regions located close to M81, where both bright UV complexes and peaks in the HI distribution are found, ii) the extended disk of M81 and iii) scattered light from the same Galactic cirrus that is responsible for the bulk of the far infrared emission.Comment: 7 pages, 7 figures, accepted for publication by A&

    An Empirical Analysis of Terrorism and Stock Market Spillovers: The Case of Spain

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    This article assesses the spillover effects between terrorist activity and Spanish stock market returns for the period 1993–2017. We construct a daily terror index that reflects the terrorist activity of different types of perpetrators: domestic terrorism (ETA) and international terrorism linked to Islamic extremism. Our static analysis shows that connectedness is important, as it explains about half of the forecast error variance; most of it is attributed to shocks from terrorist events on stock market return forecasts. Our dynamic analysis also uncovers an increase in spillover effects between the early period characterised by ETA terrorist attacks and the recent past characterised by Islamic terrorist attacks

    Redistributive effects of regional transfers: a conceptual framework

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    This paper presents a conceptual framework to analyse the redistributive impact of transfers in the context of a decentralized economy. The framework is illustrated by means of a numerical example that describes an economy with three regions and two levels of government -the central level and the regional level-. With this set up, the paper analyses a variety of transfer systems and considers its effects on redistribution using as benchmark a centralized version of this economy, in which tax capacity is unevenly distributed across the three regions and central government public expenditure is distributed across regions according to their population

    Association of MC1R Variants and host phenotypes with melanoma risk in CDKN2A mutation carriers: a GenoMEL study

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    <p><b>Background</b> Carrying the cyclin-dependent kinase inhibitor 2A (CDKN2A) germline mutations is associated with a high risk for melanoma. Penetrance of CDKN2A mutations is modified by pigmentation characteristics, nevus phenotypes, and some variants of the melanocortin-1 receptor gene (MC1R), which is known to have a role in the pigmentation process. However, investigation of the associations of both MC1R variants and host phenotypes with melanoma risk has been limited.</p> <p><b>Methods</b> We included 815 CDKN2A mutation carriers (473 affected, and 342 unaffected, with melanoma) from 186 families from 15 centers in Europe, North America, and Australia who participated in the Melanoma Genetics Consortium. In this family-based study, we assessed the associations of the four most frequent MC1R variants (V60L, V92M, R151C, and R160W) and the number of variants (1, ≥2 variants), alone or jointly with the host phenotypes (hair color, propensity to sunburn, and number of nevi), with melanoma risk in CDKN2A mutation carriers. These associations were estimated and tested using generalized estimating equations. All statistical tests were two-sided.</p> <p><b>Results</b> Carrying any one of the four most frequent MC1R variants (V60L, V92M, R151C, R160W) in CDKN2A mutation carriers was associated with a statistically significantly increased risk for melanoma across all continents (1.24 × 10−6 ≤ P ≤ .0007). A consistent pattern of increase in melanoma risk was also associated with increase in number of MC1R variants. The risk of melanoma associated with at least two MC1R variants was 2.6-fold higher than the risk associated with only one variant (odds ratio = 5.83 [95% confidence interval = 3.60 to 9.46] vs 2.25 [95% confidence interval = 1.44 to 3.52]; Ptrend = 1.86 × 10−8). The joint analysis of MC1R variants and host phenotypes showed statistically significant associations of melanoma risk, together with MC1R variants (.0001 ≤ P ≤ .04), hair color (.006 ≤ P ≤ .06), and number of nevi (6.9 × 10−6 ≤ P ≤ .02).</p> <p><b>Conclusion</b> Results show that MC1R variants, hair color, and number of nevi were jointly associated with melanoma risk in CDKN2A mutation carriers. This joint association may have important consequences for risk assessments in familial settings.</p&gt

    Does financial VAT affect the size of the financial sector?

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    The influence of VAT applied to financial services on the size of the financial sector is analyzed empirically. The authors use data from 36 European Union and OECD countries for the period from 1961 to 2012. Dynamic panel data techniques are used, concretely the GMM System. An unbalanced panel is handled. The results allow the authors to support the theoretical analysis that financial VAT has no significant effect on financial sector development. Results are robust to the specifications of the dependent and target variables and to the econometric method applied
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