312 research outputs found

    Optimizing the CSP-Calcium Looping integration for Thermochemical Energy Storage

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    Thermochemical energy storage (TCES) is considered a promising technology to overcome the issues of intermittent energy generation in Concentrated Solar Power (CSP) plants and couple them with yearly electricity demand. The development of this technology could favor the commercial deployment of CSP, which is considered as a key factor for new challenges in reducing GHG emissions. Among other possibilities, using the Calcium Looping (CaL) process for TCES is an interesting choice mainly due to the low cost of natural CaO precursors such as limestone (below $10/ton) and the high energy density that can be achieved (around 3.2 GJ/m3). This manuscript explores several configurations in order to maximize the performance of the CSP-CaL integration with the focus on power cycle integration in the carbonator zone. For this purpose, firstly, a discussion about the possibility of using open and closed power cycles is carried out, which leads to the conclusion that a CO2closed cycle is more appropriate. Then, a closed regenerative CO2Brayton cycle is analyzed in further detail and optimized by means of the pinch-analysis methodology. A main output is that high plant efficiencies (of about 45%) can be achieved using a simple closed CO2Brayton power cycle. The optimized integration layout shows good performances at carbonator to turbine outlet pressure ratios around 3, thus allowing for a feasible integration of the power cycle in the CSP-CaL system.Ministerio de Economía y Competitividad CTQ2014-52763-C2-2-

    Power cycles integration in concentrated solar power plants with energy storage based on calcium looping

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    Efficient, low-cost and environmentally friendly storage of thermal energy stands as a main challenge for large scale deployment of solar energy. This work explores the integration into concentrated solar power plants of the calcium looping process based upon the reversible carbonation/calcination of calcium oxide for thermochemical energy storage. An efficient concentrated solar power-calcium looping integration would allow storing energy in the long term by calcination of calcium carbonate thus overcoming the hurdle of variable power generation from solar. After calcination, the stored products of the reaction (calcium oxide and carbon dioxide) are brought together in a carbonator reactor whereby the high temperature exothermic reaction releases the stored energy for efficient power production when needed. This work analyses several power cycle configurations with the main goal of optimizing the performance of the overall system integration. Possible integration schemes are proposed in which power production is carried out directly (using a closed carbon dioxide Brayton power cycle) or indirectly (by means of a steam reheat Rankine cycle or a supercritical carbon dioxide Brayton cycle). The results obtained show that the highest plant efficiencies (up to 45–46%) are achievable using a closed carbon dioxide Brayton power cycle.Ministerio de Economia y Competitividad CTQ2014-52763-C2-1-R, CTQ2014- 52763-C2-2-R, MAT2013-41233-

    Emotion detection through biomedical signals: A pilot study

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    Emotions are affective states accompanied by physiological reactions that affect cognition processes such as decision making, perception, and learning. Emotion detection can be helpful in fields like education, sports and accident prevention. In this pilot study, we used biosensors to measure heart rate and galvanic skin response of twenty-eight volunteers (fourteen male, fourteen female). They were asked to watch video clips to elicit two target emotions: Amusement and anger. The purpose of this study was to determine the relationship between mean values of biosignals and emotional states (including amusement, anger and neutral state). From the analysis of variance, Fisher least significant difference and Multiple Range test, it was observed that emotions elicited with video clips influence mean values and other features of physiological signals with a confidence level of 90%. © SPIE. Downloading of the abstract is permitted for personal use only

    Long-term evolution of shrub prescribed burning effects on topsoil organic matter and biological activity in the Central Pyrenees (NE-Spain)

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    Since the last half of the 20th Century, scrubs have been invading subclimatic grasslands in the montane and subalpine stages of Spain due to the decrease of the grazing activity. This shrub encroachment reduces biodiversity and the ecopastoral value of the region and leads to the accumulation of woody fuel, which represents a high fire risk. To control the encroachment, prescribed burnings are performed but their effects on soils over the years are still undetermined. This study aims to research about the long-term effects of a prescribed burn of Echinospartum horridum (Vahl) Roth. on topsoil organic matter and biological activity. Soil sampling was carried out in Tella-Sin (Central Pyrenees, Aragón, Spain) and four treatments were selected: unburned (UB), immediately burned (B0), burned 6 years before (B6, mid-term) and burned 10 years before (B10, long-term). Among the obtained results, an immediately after burning decrease on β-D-glucosidase activity (GLU) was found, which did not recover over time. Other properties did not have an immediate reduction but did so over time: total soil organic carbon (SOC), labile carbon (DOC), total nitrogen (TN), basal soil respiration (bSR). And others were not affected at all: microbial biomass carbon (MBC), and the microbial metabolic quotient (qCO2). Moreover, the normalized soil respiration (nSR) increased with the time, which implies an acceleration of the potential mineralization of soil organic carbon. In short, although the elimination of the dense shrubs by fire has not entailed major immediate soil modifications, which would be typical of a low severity prescribed burn, several mid- and long-term effects in the C cycle have been observed. Future studies will have to discern what is the main cause of these modifications (soil microbial composition, edaphoclimatic changes, lack of soil cover and soil loss, soil fertility, etc.)

    Thermochemical energy storage of concentrated solar power by Integration of the calcium looping process and a CO2 power cycle

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    Energy storage is the main challenge for a deep penetration of renewable energies into the grid to overcome their intrinsic variability. Thus, the commercial expansion of renewable energy, particularly wind and solar, at large scale depends crucially on the development of cheap, efficient and non-toxic energy storage systems enabling to supply more flexibility to the grid. The Ca-Looping (CaL) process, based upon the reversible carbonation/calcination of CaO, is one of the most promising technologies for thermochemical energy storage (TCES), which offers a high potential for the long-term storage of energy with relatively small storage volume. This manuscript explores the use of the CaL process to store Concentrated Solar Power (CSP). A CSPCaL integration scheme is proposed mainly characterized by the use of a CO2 closed loop for the CaL cycle and power production, which provides heat decoupled from the solar source and temperatures well above the ~550ºC limit that poses the use of molten salts currently used to store energy as sensible heat. The proposed CSP-CaL integration leads to high values of plant global efficiency (of around 45-46%) with a storage capacity that allows for long time gaps between load and discharge. Moreover, the use of environmentally benign, abundantly available and cheap raw materials such as natural limestone would mark a milestone on the road towards the industrial competitiveness of CSP

    Vehicle Classification in Traffic Environments Using the Growing Neural Gas

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    Traffic monitoring is one of the most popular applications of automated video surveillance. Classification of the vehicles into types is important in order to provide the human traffic controllers with updated information about the characteristics of the traffic flow, which facilitates their decision making process. In this work, a video surveillance system is proposed to carry out such classification. First of all, a feature extraction process is carried out to obtain the most significant features of the detected vehicles. After that, a set of Growing Neural Gas neural networks is employed to determine their types. A qualitative and quantitative assessment of the proposal is carried out on a set of benchmark traffic video sequences, with favorable results.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

    Effectiveness of a multifactorial intervention in increasing adherence to the mediterranean diet among patients with diabetes mellitus type 2: a controlled and randomized study (EMID Study)

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    The Mediterranean diet (MD) is recognized as one of the healthiest dietary patterns and has benefits such as improving glycaemic control among patients with type 2 diabetes (T2DM). Our aim is to assess the effectiveness of a multifactorial intervention to improve adherence to theMD, diet quality and biomedical parameters. The EMID study is a randomized and controlled clinical trial with two parallel groups and a 12-month follow-up period. The study included 204 subjects between 25–70 years with T2DM. The participants were randomized into intervention group (IG) and control group (CG). Both groups received brief advice about healthy eating and physical activity. The IG participants additionally took part in a food workshop, five walks and received a smartphone application for three months. The population studied had a mean age of 60.6 years. At the 3-month follow-up visit, there were improvements in adherence to the MD and diet quality of 2.2 and 2.5 points, compared to the baseline visit, respectively, in favour of the IG. This tendency of the improvement was maintained, in favour of the IG, at the 12-month follow-up visit. In conclusion, the multifactorial intervention performed could improve adherence to the MD and diet quality among patients with T2DM.Regional Health Management through the 2016 grants to carry out research projects in biomedicine, health management and socio-health care (GRS 1276/B/16), the 2016 program for the professional development of nurses in their research activity (BOCYL-D-11022016-2) and the 2015 incentive program for nurses who have completed their residency (ORDER SAN / 360/2015). The study was also co-financed by the Carlos III Health Institute and the European Regional Development Fund (ERDF) (RD 16/0007/0003)

    Vascular and cognitive effects of cocoa-rich chocolate in postmenopausal women: a study protocol for a randomised clinical trial

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    Introduction The intake of polyphenols has certain health benefits. This study will aim to assess the effect of adding a daily amount of chocolate high in cocoa content and polyphenols to the normal diet on blood pressure, vascular function, cognitive performance, quality of life and body composition in postmenopausal women. Methods and analysis Here we plan a randomised clinical trial with two parallel groups involving a total of 140 women between 50 and 64 years in the postmenopausal period, defined by amenorrhoea of at least 12 consecutive months. The main variable will be the change in blood pressure. Secondary variables will be changes in vascular function, quality of life, cognitive performance and body composition. The intervention group will be given chocolate containing 99% cocoa, with instructions to add 10 g daily to their normal diet for 6 months. The daily nutritional contribution of this amount of chocolate is 59 kcal and 65.4 mg of polyphenols. There will be no intervention in the control group. All variables will be measured at the baseline visit and 3 and 6 months after randomisation, except cognitive performance and quality of life, which will only be assessed at baseline and at 6 months. Recruitment is scheduled to begin on 1 June 2018, and the study will continue until 31 May 2019. Ethics and dissemination This study was approved by the Clinical Research Ethics Committee of the Health Area of Salamanca, Spain (‘CREC of Health Area of Salamanca’), in February 2018. A SPIRIT checklist is available for this protocol. The clinical trial has been registered at ClinicalTrials. gov provided by the US National Library of Medicine, number NCT03492983. The results will be disseminated through open access peer-reviewed journals, conference presentations, broadcast media and a presentation to stakeholders.Gerencia Regional de Castilla y León (GRS 1583/B/1
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