CFD model-based analysis and experimental assessment of key design parameters for an integrated unglazed metallic thermal collector façade

Active façade systems incorporating solar thermal collectors currently offer very promising energetic solutions. From among the available systems, a simple solution is the unglazed heat collector for potential integration in low-temperature applications. However, when adopting system definitions, the modification of some design parameters and their impact has to be fully understood. In this study, the case of an unglazed collector integrated into a sandwich panel is assessed and a specific analysis is performed for a proper assessment of the influence of key design parameters. Based on that case study of the real built system, a CFD model is developed and validated and a parametric assessment is then performed, by altering the configurations of both the panel and the hydraulic circuit. In this way, the potential of each measure to harness solar energy can be evaluated and each parameter with its different level of impact can be highlighted, to identify those of higher relevance. A characterization of the real solution completes the study, by providing the efficiency curves and the total energy collected during the experimental campaign. The maximum estimate of the efficiency of a 6 m2 façade was within a range between 0.47 and 0.34 and the heat loss factor was between 4.8 and 7.5. The case study exercises reveal the real energy efficiency and solar production patterns. There was also an opportunity to consider significant improvements to increase the output of the active façade. The main conclusions concerned the different criteria that improved the definition of the system and greater comprehension of alternative designs that may be integrated in the underlying concept.The authors are grateful to the Basque Government for fundingthis research through projects IT781-13 and IT1314-19 and to allthose involved in the different stages for their guidance andinvaluable help.The authors would also like to thank all those companies andresearchers participating in the BASSE project for their stronginvolvement during that research. Results from BASSE project haveinspired present research. The BASSE project received funding fromthe European Union, RFCS Program, Research Fund for Coal and Steel project Building Active Steel Skin (BASSE, Grant Agreement noRFSR-CT-2013-00026

Experimentation under real performing conditions of a highly integrable unglazed solar collector into a building façade

In the current context of moving towards more sustainable construction, advanced façade systems that integrate solar collecting devices represent a commitment with future trends that combine renewable technologies with building skins. This paper describes a real experience when combining a novel unglazed solar collector based on sandwich panel technology, a heat pump and a controller that manages the different operation modes. Installed in the Kubik by Tecnalia testing building in northern Spain, the system has been monitored for several months in 2016, under an energy efficiency scope. The study will present measured values regarding the yield of the collector, performance of the heat pump and general efficiencies.The research leading to the results reported in this work has received funding from the European Union, RFCS Program, Research Fund for Coal and Steel project Building Active Steel Skin (BASSE, Grant Agreement no RFSRCT-2013-00026

NEXT21- an experiment

With the aim of creating a green, social, energy-efficient and adaptive urban living environment fit for the challenges of the 21st century and its demands, Osaka Gas commissioned the experimental residential complex `NEXT21` in Osaka in 1989, built in 1993. 15 years into its existence and three consecutive five-year cycles of ongoing inhabitation experimentation, the 30 minute documentary `NEXT21 - an experiment` looks back on the context and conditions of that visionary and pioneering multi-disciplinary design process. Due to the mounting collective concern for the threat of climate change, ecology and sustainable building have once again regained public attention since the oil crisis of the late 70’s. The challenge for designers today is to use this momentum and to transform it into a widely supported and effective sustainable development of the built environment. The precondition is to not only to start working on it with enthusiasm, but also to look back to extract valuable lessons from the richness of our recent past; results of realized pioneering projects and still ongoing experiments. The NEXT21 project in Osaka is one of the rare Open Bulding projects that did manage to capture the imagination and still up to today remains a fascinating building. Its complex design process was determined by the succesful cooperation of a group of professionals from different disciplines. An interesting question we asked was: what does this project have that the others don’t? What is it’s X-factor? Can understanding the mechanisms at work help us create better buildings and so widen the support for sustainability? To gain insight in the X-factor and it’s creation is what motivated the making of this documentary and it is our opinion crucial for the successful proliferation of ecological and sustainable building

Novel Evaporation Process for Deposition of Kesterite Thin Films Synthesized by Solvothermal Method

Kesterite, a quaternary compound of Cu2ZnSnS4, is a promising option as a material absorber to reduce the cost of photovoltaic solar cells. The solvothermal method is a way to synthesize nanoparticles of this material. In this work, once synthesized, particles were deposited on a substrate through evaporation, and their morphological, structural, and optical properties were studied. Results show that changes of precursor ratios during solvothermal synthesis result in a modification of particle morphology but not on its size. The deposition of already synthesized kesterite through evaporation preserves kesterite structure and permits the formation of a homogenous film on a substrate. Optical reflectance and transmittance measurements allowed estimating the band-gap energy between 1.41 and 1.46 eV for representative samples, which is near the optimum for the absorber material

Effects of vaccination before or after M. a. subsp. paratuberculosis (Map) experimental infection in goats

Trabajo presentado al 13th International Colloquium on Paratuberculosis. Nantes, Francia, 20-24 junio, 2016.Previous field studies have pointed out that vaccination of adult animals, presumably already infected with Map, decreases the appearance of new clinical cases, suggesting a therapeutic effect. With the aim of investigating the effects of vaccination, a total of 35, 1.5 month-old goat kids were employed. Eight of them were vaccinated subcutaneously with 1ml of an inactivated vaccine (Silirum®), and one month later orally challenged with 1010 CFU of the Map K-10 strain. At the same time, 14 non-vaccinated kids were similarly infected. The rest of the animals were kept as vaccinated (5) or non vaccinated non infected (8) controls. The peripheral immune response was assessed by indirect ELISA and IFN-a release tests. At 150 days post-infection (dpi), 5 infected and 3 infected and vaccinated kids were pathologically examined. After lesion development verification, five already infected kids were vaccinated with the same product at 180 dpi. At 360 dpi all the animals were slaughtered. A significant increase in IFN-a production was detected in all the vaccinated animals 1 month post-vaccination, that was significantly lower in those vaccinated after the infection. At 150 dpi, granulomatous lesions were identified both in infected and in vaccinated-infected kids, but the number of granulomas were significantly higher in the former group. Moreover, in vaccinated-infected animals lesions were restricted to the lymphoid tissue (focal forms) and demarcated whereas in the unvaccinated group they were seen in the mucosa either related or not to the Peyer’s patches. Among kids slaughtered at 360 dpi, only one of those vaccinated prior to infection had lesions and these were only few focal granulomas whereas more severe lesions, and with no differences between groups, were found in those animals only infected or those vaccinated after the infection. According to these results, vaccination does not prevent infection but has a clear protective effect if administered before challenge; however, in most of the animals with an established infection, vaccination does not stop the progression of the lesions.Peer Reviewe

Paratuberculosis vaccinated cattle lifespan and unspecific protection

Trabajo presentado al 13th International Colloquium on Paratuberculosis. Nantes, Francia, 20-24 junio, 2016.Mycobacterial vaccination is a controversial subject. In general, the emphasis for fighting TB was on diagnosis based on the grounds that identifying infected individuals and dealing with them, either by treatment in humans or by culling in animals was the most specific and efficient strategy. This perspective has also marked the approach to the other relevant cattle micobacteriosis, paratuberculosis, in spite of overwhelming evidence on vaccine efficacy. Since there is strong evidence of an unspecific effect on children culling by BCG vaccination, we wanted to know whether or not such an effect was also present in paratuberculosis vaccinated cattle. Age at culling for 3547 cows vaccinated at over 3 months of age and 1731 of matched age but not vaccinated, and of 80 and 782 cows vaccinated within their 3 first months of life during a period of 9 years in 26 Friesian herds was recorded and submitted to survival analysis in one year intervals using the LIFETEST procedure of the SAS statistical package in order to compare cattle lifespan between groups. In another study on 987 Friesian slaughtered cows, three epidemiopathogenic forms of paratuberculosis were defined. Age of these animals according to patency or not was submitted to a similar analysis in order to compare the effects of paratuberculosis on cattle lifespan and to estimate the frequency of clinical paratuberculosis incidence per year of age. The Sidak logrank test showed no significant difference for cattle vaccinated after 3 months of age (p=0.3146), but highly significant for animals vaccinated earlier (p=0.0004). Maximum differences between vaccinated an unvaccinated animals occurred in animals between 1 and 4 years old, with 6.7%, 12.4%, 11.0% and 8.9% differences at each one year interval. Comparing with patent paratuberculosis, there was 6.7%, 9.8% and 1.8% less culling associated to vaccination at 1, 2 and 3 years of age than that associated to patent forms in the slaughterhouse study. These frequencies were considered as unspecific protection and represented a reduction of unvaccinated controls culling at those years of 31%, 19% and 2%. Paratuberculosis specific protection was 5% at 2 years of age and then 12%, 10%, 5%, 1% and 1% in the successive years. These results confirm an association of paratuberculosis vaccination with extended cattle lifespan and an unspecific effect during the first years of life that is similar to that observed in human tuberculosis vaccination suggesting that collateral benefits of paratuberculosis vaccination might be a non-negligible part of its effects.Peer Reviewe