587 research outputs found

    Optimized method for black carbon analysis in ice and snow using the Single Particle Soot Photometer

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    In this study we attempt to optimize the method for measuring black carbon (BC) in snow and ice using a Single Particle Soot Photometer (SP2). Beside the previously applied ultrasonic (CETAC) and Collison-type nebulizers we introduce a jet (Apex Q) nebulizer to aerosolize the aqueous sample for SP2 analysis. Both CETAC and Apex Q require small sample volumes (a few milliliters) which makes them suitable for ice core analysis. The Apex Q shows the least size-dependent nebulizing efficiency in the BC particle diameter range of 100–1000 nm. The CETAC has the advantage that air and liquid flows can be monitored continuously. All nebulizer-types require a calibration with BC standards for the determination of the BC mass concentration in unknown aqueous samples. We found Aquadag to be a suitable material for preparing calibration standards. Further, we studied the influence of different treatments for fresh discrete snow and ice samples as well as the effect of storage. The results show that samples are best kept frozen until analysis. Once melted, they should be sonicated for 25 min, immediately analyzed while being stirred and not be refrozen

    Developement of real time diagnostics and feedback algorithms for JET in view of the next step

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    Real time control of many plasma parameters will be an essential aspect in the development of reliable high performance operation of Next Step Tokamaks. The main prerequisites for any feedback scheme are the precise real-time determination of the quantities to be controlled, requiring top quality and highly reliable diagnostics, and the availability of robust control algorithms. A new set of real time diagnostics was recently implemented on JET to prove the feasibility of determining, with high accuracy and time resolution, the most important plasma quantities. With regard to feedback algorithms, new model–based controllers were developed to allow a more robust control of several plasma parameters. Both diagnostics and algorithms were successfully used in several experiments, ranging from H-mode plasmas to configuration with ITBs. Since elaboration of computationally heavy measurements is often required, significant attention was devoted to non-algorithmic methods like Digital or Cellular Neural/Nonlinear Networks. The real time hardware and software adopted architectures are also described with particular attention to their relevance to ITER.Comment: 12th International Congress on Plasma Physics, 25-29 October 2004, Nice (France

    Impact of aftertreatment devices on primary emissions and secondary organic aerosol formation potential from in-use diesel vehicles: results from smog chamber experiments

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    Diesel particulate matter (DPM) is a significant source of aerosol in urban areas and has been linked to adverse health effects. Although newer European directives have introduced increasingly stringent standards for primary PM emissions, gaseous organics emitted from diesel cars can still lead to large amounts of secondary organic aerosol (SOA) in the atmosphere. Here we present results from smog chamber investigations characterizing the primary organic aerosol (POA) and the corresponding SOA formation at atmospherically relevant concentrations for three in-use diesel vehicles with different exhaust aftertreatment systems. One vehicle lacked exhaust aftertreatment devices, one vehicle was equipped with a diesel oxidation catalyst (DOC) and the third vehicle used both a DOC and diesel particulate filter (DPF). The experiments presented here were obtained from the vehicles at conditions representative of idle mode, and for one car in addition at a speed of 60 km/h. An Aerodyne high-resolution time-of-flight aerosol mass spectrometer (HR-ToF-AMS) was used to measure the organic aerosol (OA) concentration and to obtain information on the chemical composition. For the conditions explored in this paper, primary aerosols from vehicles without a particulate filter consisted mainly of black carbon (BC) with a low fraction of organic matter (OM, OM/BC < 0.5), while the subsequent aging by photooxidation resulted in a consistent production of SOA only for the vehicles without a DOC and with a deactivated DOC. After 5 h of aging ~80% of the total organic aerosol was on average secondary and the estimated "emission factor" for SOA was 0.23–0.56 g/kg fuel burned. In presence of both a DOC and a DPF, only 0.01 g SOA per kg fuel burned was produced within 5 h after lights on. The mass spectra indicate that POA was mostly a non-oxidized OA with an oxygen to carbon atomic ratio (O/C) ranging from 0.10 to 0.19. Five hours of oxidation led to a more oxidized OA with an O/C range of 0.21 to 0.37

    Modified carbon fabric electrodes: preparation and electrochemical behavior toward amaranth electrolysis

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    The final publication is available at Springer via http://dx.doi.org/10.1007/s10800-014-0769-9The electrochemical behavior of non-modified, Pt-modified, and Pt/polyaniline-modified carbon fiber textile electrodes was studied through a series of electrolyses, under potentiostatic conditions, on an amaranth/sulfuric solution in the presence or absence of chloride ion. The morphology of the dispersed Pt, PANI, and PANI/Pt coatings was analyzed by scanning electron microscopy. Scanning electrochemical microscopy confirmed that the textile surface was effectively modified by the electrocatalytic material. Color removal reached values above 90 % in both electroreduction and electrooxidation processes. The amaranth electroreductions carried out with the non-modified electrode showed better charge efficiency than those with the Pt-modified textile electrode. The electrooxidations with Pt-modified textile electrodes showed a significant reduction in electrolysis time. Ultraviolet-visible and Fourier transform infrared with attenuated total reflection spectra enabled the electrochemical behavior of the non-modified and Pt/PANI-modified electrodes to be distinguished.The authors wish to acknowledge to the Spanish Ministerio de Ciencia e Innovacion (contract CTM2011-23583) and Universitat Politecnica de Valencia (Vicerrectorado de Investigacion PAID-06-10 contract 003-233) for the financial support; and as well as Carbongen S. A. (Cocentaina, Spain), who kindly donated the activated carbon fabric. J. Molina is grateful to the Conselleria d'Educacio, Formacio i Ocupacio (Generalitat Valenciana) for the Programa VALi+D Postdoctoral Fellowship. A.I. del Rio is grateful to the Spanish Ministerio de Ciencia y Tecnologia for the FPI fellowship.Fernández Sáez, J.; Del Río García, AI.; Molina Puerto, J.; Bonastre Cano, JA.; Cases Iborra, FJ. (2015). Modified carbon fabric electrodes: preparation and electrochemical behavior toward amaranth electrolysis. Journal of Applied Electrochemistry. 45(3):263-272. https://doi.org/10.1007/s10800-014-0769-9S263272453Marsh H, Reinoso FR (2000) Sciences of carbon materials. Universidad de Alicante, AlicanteKinoshita K (1998) Carbon: electrochemical and physicochemical properties. Wiley, New York, pp 293–387Burchell TD (1999) Carbon materials for advances technologies. Pergamon, AmsterdamDomínguez SD, Pardilla JA, Murcia AB, Morallón E, Amorós DC (2008) Electrochemical deposition of Pt nanoparticles on different carbon supports and conducting polymers. J Appl Electrochem 38:259–268Kezhong W, Xu M, Xindong W, Jingling L (2005) Pt–Polyaniline-modified carbon fiber electrode for the electrooxidation of methanol. Rare Met 24:33–36Wu G, Li L, Li JH, Xu BQ (2006) Methanol electrooxidation on Pt particles dispersed into PANI/SWNT composite films. J Power Sources 155:118–127Singh RN, Awasthi R, Tiwari SK (2010) Electro-catalytic activities of binary nano-composites of Pt and nano-carbon/multiwall carbon nanotube for methanol electro-electrooxidation. Open Catal J 3:50–57Zhiani M, Rezaei B, Jalili J (2010) Methanol electro-electrooxidation on Pt/C modified by polyaniline nanofibers for DMFC applications. Int J Hydrogen Energ 35:9298–9305Laborde H, Léger J-M, Lamy C (1994) Electrocatalytic electrooxidation of methanol and C1 molecules on highly dispersed electrodes. Part 1: Pt in polyaniline. J Appl Electrochem 24:219–226Niu L, Li Q, Wei F, Wu S, Liu P, Cao X (2005) Electrocatalytic behaviour of Pt-modified polyaniline electrode for methanol electrooxidation: effect of Pt deposition modes. J Electroanal Chem 578:331–337Huang LM, Tang WR, Wen TCh (2007) Spatially electrodeposited Pt in polyaniline doped with poly(styrene sulfonic acid) for methanol electrooxidation. J Power Sources 164:519–526Fernández J, Molina J, del Río AI, Bonastre J, Cases FJ (2012) Synthesis and characterization of electrochemically platinum–polyaniline modified carbon textile electrodes. Int J Electrochem Sci 7:10175–10189Snehalatha M, Ravikumar C, Sekar N, Jayakumar SV, Joe H (2008) FT–Raman, IR and UV–visible spectral investigations and ab initio computations of a nonlinear food dye amaranth. J Raman Spectrosc 39:928–936Rajendran L, Ananthi SP (2004) Analysis of positive feedback currents at the scanning electrochemical microscope. J Electroanal Chem 561:113–118Niu L, Li Q, Wei F, Chen X, Wang W (2003) Formation optimization of Pt-modified polyaniline films for the electrocatalytic electrooxidation of methanol. Synthetic Met 139:271–276Sala M, del Río AI, Molina J, Cases F, Gutierrez-Bouzán MC (2012) Influence of cell design and electrode materials on the decoloration of dyeing effluents. Int J Electrochem Sc 7:12470–12488Priyantha N, Malavipathirana S (1996) Effect of chloride ions on the electrochemical behavior of platinum surfaces. J Natn Sci Coun Sri Lanka 24:237–246Rajeev J, Nidhi Sh, Keisham R (2009) Electrochemical treatment of pharmaceutical azo dye amaranth from waste water. J Appl Electochem 39:577–582Nadupalli S, Koorbanally N, Jonnalagadda SB (2011) Kinetics and mechanism of the oxidation of amaranth with hypochlorite. J Phys Chem A 115:7948–795

    Ecofog - Gagner en compétitivité et réduire les impacts environnementaux de la filière foie gras

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    On a worldwide scale, France is the leading producer of foie gras. To maintain this leadership, the sector must remain competitive and control its production costs while meeting specific societal and environmental expectations such as preservation of product quality, respect for animal welfare or limited use of natural resources. The aim of the project was to develop innovative production systems that would limit the impacts of feed and its surrounding practices on the competitiveness of the sector and the environment. An experimental approach was associated with a multi-criteria sustainability assessment (farm level), complemented by an analysis of production cost (farm level) and environmental impacts (product level). Two domains were studied: one related to feed, and the other related to ambient conditions during breeding and force-feeding. Several issues have been identified to progress. Reducing the amount of food distributed (-10%) appears as a possible solution to reduce feeding costs during rearing. The use of sorghum is also of interest but its use should be limited to the rearing phase. Lastly, semi-open air system, compared to open-air system, helps to improve IC (Consumption Index) and reduces animal heterogeneity and mortality. This project also provided original results related to the understanding of mechanisms involved in body temperature regulation of ducks on the one hand and on the other hand to LCA results of different innovations. Lastly, it contributed to the creation of two tools: one to drill ventilation ducts and another to calculate production costs. The results were disseminated to the professionals throughout the project in order to make all data available.À l’échelle mondiale, la France est le premier producteur de foie gras. Afin de conserver ce leadership, la filière doit rester compétitive et maîtriser ses coûts de production tout en répondant à des attentes sociétales et environnementales spécifiques telles que la préservation de la qualité des produits, le respect du bien-être animal ou la gestion économe des ressources. Le projet ECOFOG avait pour objectif de développer des systèmes de production innovants, permettant de limiter l’impact de l’alimentation des canards et des pratiques qui l’entourent pour gagner en compétitivité de la filière et diminuer l’impact environnemental de la filière. La démarche expérimentale a été associée à une démarche d’évaluation multicritère de la durabilité à l’échelle de l’atelier, complétée par une analyse des coûts de production à l’échelle de l’atelier et des impacts environnementaux à l’échelle du produit. Deux axes d’étude ont en particulier été développés : l’un autour de l’aliment, et l’autre autour des conditions d’ambiance en élevage et en gavage.Plusieurs pistes ont été identifiées pour progresser. La réduction de la quantité d’aliment distribué (-10%) est une solution possible pour réduire les coûts d'alimentation. L’utilisation de sorgho présente par ailleurs un intérêt environnemental mais son utilisation devrait être limitée à la phase d’élevage. En termes de bâtiments enfin, le système semi plein-air, comparé au système plein-air, contribue à améliorer l’IC (Indice de Consommation) et réduit les écarts de poids entre les animaux et la mortalité. Ce projet a permis d’obtenir des résultats originaux sur les mécanismes impliqués dans la régulation de la température corporelle des canards. Il a aussi permis d’évaluer les impacts environnementaux de la production de foie gras, et d’analyser les conséquences des différents systèmes de production innovants sur les performances, les coûts et la durabilité de la production. Il a enfin contribué à la création de deux outils utiles pour la filière : un outil d’aide au perçage des gaines de ventilation en atelier de gavage et un outil de calcul du coût de production. Ces résultats ont été largement diffusés vers les professionnels afin de rendre l’ensemble de ces données disponibles

    Emotional intelligence buffers the effect of physiological arousal on dishonesty

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    We studied the emotional processes that allow people to balance two competing desires: benefitting from dishonesty and keeping a positive self-image. We recorded physiological arousal (skin conductance and heart rate) during a computer card game in which participants could cheat and fail to report a certain card when presented on the screen to avoid losing their money. We found that higher skin conductance corresponded to lower cheating rates. Importantly, emotional intelligence regulated this effect; participants with high emotional intelligence were less affected by their physiological reactions than those with low emotional intelligence. As a result, they were more likely to profit from dishonesty. However, no interaction emerged between heart rate and emotional intelligence. We suggest that the ability to manage and control emotions can allow people to overcome the tension between doing right or wrong and license them to bend the rules

    \u201cGive, but Give until It Hurts\u201d: The Modulatory Role of Trait Emotional Intelligence on the Motivation to Help

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    Two studies investigated the effect of trait Emotional Intelligence (trait EI) on people\u2019s moti- vation to help. In Study 1, we developed a new computer-based paradigm that tested partic- ipants\u2019 motivation to help by measuring their performance on a task in which they could gain a hypothetical amount of money to help children in need. Crucially, we manipulated partici- pants\u2019 perceived efficacy by informing them that they had been either able to save the chil- dren (positive feedback) or unable to save the children (negative feedback). We measured trait EI using the Trait Emotional Intelligence Questionnaire\u2013Short Form (TEIQue-SF) and assessed participants\u2019 affective reactions during the experiment using the PANAS-X. Results showed that high and low trait EI participants performed differently after the presen- tation of feedback on their ineffectiveness in helping others in need. Both groups showed increasing negative affective states during the experiment when the feedback was negative; however, high trait EI participants better managed their affective reactions, modulating the impact of their emotions on performance and maintaining a high level of motivation to help. In Study 2, we used a similar computerized task and tested a control situation to explore the effect of trait EI on participants\u2019 behavior when facing failure or success in a scenario unre- lated to helping others in need. No effect of feedback emerged on participants\u2019 emotional states in the second study. Taken together our results show that trait EI influences the impact of success and failure on behavior only in affect-rich situation like those in which people are asked to help others in need
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