As a result of the huge economic and industrial development that human has been experiencing for decades or centuries, there are millions of potentially contaminated sites around the globe. Potentially contaminated sites are those which industrial, agricultural, mining and waste containment activities with potential to contaminate soil and groundwater has taken place in. A small number of these contains dangerous levels of contamination and much fewer have been remediated so far. As an example, in Europe, according to European Environmental Agency in 2014 there are some 2,500,000 potentially contaminated sites with an estimated number of about 342,000 sites that contain significant contamination needing remediation., of which just about 15% have been remediated [1]. The situation is probably much worse when it comes to most developing countries. Here, there is usually no priority regarding remediation even though it is well known that contamination is related to public health. In these countries, there is often a lack of data regarding contaminated sites and levels of contamination. Sometimes, authorities deny any contamination and in any case no actions may be taken for the use of specific water supply wells. In some cases, the reason may be inefficient regulation and lack of funding for surveying and remediation [2]. A basic problem is that the remediation process of contaminated soil and groundwater is a complex and multidisciplinary issue and there are no efficient and reliable general tools to help in the decision-making practise. The different kinds of possible contaminants and variation of soil parameters result in a physical system with many degrees of freedom. To this are added the social, economic, and environmental aspects needed to be considered when making sustainable decisions for the remediation activities. In this study, generally available decision-making tools, systems and methods for contaminated site remediation, are critically reviewed first. Secondly, the importance of incorporating contaminant transport properties for different chemicals in the decision-making process is exemplified for a case study in Iran. In this case study an unconfined aquifer contaminated by selenium, cadmium and antimony is modelled, aiming to find solutions for dealing with the contamination. Due to the complex situation at the site, which is usually the case in reality, the results showed why current tools are rarely used for decision making process in contaminated site management and it is essential to make better models and integrate them to make better decisions. After this case study, the difference in results by different multi-criteria decision-making algorithms is shown. The main objective of this study is to show shortcomings in current practices of decision making for contaminated sites remediation. It is shown that we need more detailed, practical and trustworthy tools to base our decisions on. It is shown that it is necessary to incorpor
{"title":"Shortcomings in Current Practices for Decision-Making Process and Contaminated Sites Remediation","authors":"Mehran Naseri Rad, R. Berndtsson","doi":"10.11159/ICEPR19.155","DOIUrl":"https://doi.org/10.11159/ICEPR19.155","url":null,"abstract":"As a result of the huge economic and industrial development that human has been experiencing for decades or centuries, there are millions of potentially contaminated sites around the globe. Potentially contaminated sites are those which industrial, agricultural, mining and waste containment activities with potential to contaminate soil and groundwater has taken place in. A small number of these contains dangerous levels of contamination and much fewer have been remediated so far. As an example, in Europe, according to European Environmental Agency in 2014 there are some 2,500,000 potentially contaminated sites with an estimated number of about 342,000 sites that contain significant contamination needing remediation., of which just about 15% have been remediated [1]. The situation is probably much worse when it comes to most developing countries. Here, there is usually no priority regarding remediation even though it is well known that contamination is related to public health. In these countries, there is often a lack of data regarding contaminated sites and levels of contamination. Sometimes, authorities deny any contamination and in any case no actions may be taken for the use of specific water supply wells. In some cases, the reason may be inefficient regulation and lack of funding for surveying and remediation [2]. A basic problem is that the remediation process of contaminated soil and groundwater is a complex and multidisciplinary issue and there are no efficient and reliable general tools to help in the decision-making practise. The different kinds of possible contaminants and variation of soil parameters result in a physical system with many degrees of freedom. To this are added the social, economic, and environmental aspects needed to be considered when making sustainable decisions for the remediation activities. In this study, generally available decision-making tools, systems and methods for contaminated site remediation, are critically reviewed first. Secondly, the importance of incorporating contaminant transport properties for different chemicals in the decision-making process is exemplified for a case study in Iran. In this case study an unconfined aquifer contaminated by selenium, cadmium and antimony is modelled, aiming to find solutions for dealing with the contamination. Due to the complex situation at the site, which is usually the case in reality, the results showed why current tools are rarely used for decision making process in contaminated site management and it is essential to make better models and integrate them to make better decisions. After this case study, the difference in results by different multi-criteria decision-making algorithms is shown. The main objective of this study is to show shortcomings in current practices of decision making for contaminated sites remediation. It is shown that we need more detailed, practical and trustworthy tools to base our decisions on. It is shown that it is necessary to incorpor","PeriodicalId":265434,"journal":{"name":"Proceedings of the 5th World Congress on New Technologies","volume":"35 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-09-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115066241","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Degradation of Selected PAH’s By Laccase-Mediator System in Soil","authors":"Ziva Vipotnik, M. Michelin, T. Tavares","doi":"10.11159/ICEPR19.133","DOIUrl":"https://doi.org/10.11159/ICEPR19.133","url":null,"abstract":"","PeriodicalId":265434,"journal":{"name":"Proceedings of the 5th World Congress on New Technologies","volume":"171 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-08-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132301048","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Spatial Information Systems as Sources of Data for Electromobility Planning","authors":"M. Staniek","doi":"10.11159/ICERT19.107","DOIUrl":"https://doi.org/10.11159/ICERT19.107","url":null,"abstract":"","PeriodicalId":265434,"journal":{"name":"Proceedings of the 5th World Congress on New Technologies","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122399045","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A. C. G. Júnior, Elio Conradi Junior, Jéssica Manfrin, D. Schwantes, Juliano Zimmermann, Guilherme Lindner Ziemer, Marcelo Ângelo Campagnolo, A. Schiller
Despite the numerous studies reporting about pesticide interactions in inumerous environmental conditions, there is insufficient information relating their dynamics to the various textural classes of Brazilian soils and, consequently, the environmental problems caused by the use and application of these compounds. In this way, the objective of this study was to evaluate the atrazine dynamics through determination of the surface runoff and percolation in a Red Latosol cultivated with maize, through studies delineated in drainage lysimeter. Applications of atrazine at the recommended doses were performed weekly up to 44 days after emergence of the maize. Rainfall simulations (150 mm) were performed 24 and 48 h after each application, collecting samples of runoff and percolated water at intervals of 5 min. The samples were sent to the laboratory for analysis of physical and chemical attributes and determination of atrazine concentrations by GC-ECD. Concentrations above the maximum values allowed by the regulatory agencies were found in approximately 99.16% of the obtained samples. The presence of atrazine in runoff and percolated water was recorded. Until 30 days after emergence (DAE) of the crop, higher concentrations of the pesticide were observed in the runoff 24 h after application, mainly in the initial collection minutes. In the percolated samples high concentrations of the pesticide were found even with the development of the crop, however, usually being smaller to those observed for surface runoff. There was a good correlation between the GUS (Groundwater Ubiquity Score) index and the GOSS model and the results obtained. It is concluded that there is the possibility of transporting atrazine in surface runoff and percolation in the different phenological stages of the maize crop when submitted to sequential applications and under high precipitation conditions.
{"title":"Use of Lysimeters to Evaluate the Atrazine Dynamics in Soil Cultivated With Maize","authors":"A. C. G. Júnior, Elio Conradi Junior, Jéssica Manfrin, D. Schwantes, Juliano Zimmermann, Guilherme Lindner Ziemer, Marcelo Ângelo Campagnolo, A. Schiller","doi":"10.11159/ICEPR19.159","DOIUrl":"https://doi.org/10.11159/ICEPR19.159","url":null,"abstract":"Despite the numerous studies reporting about pesticide interactions in inumerous environmental conditions, there is insufficient information relating their dynamics to the various textural classes of Brazilian soils and, consequently, the environmental problems caused by the use and application of these compounds. In this way, the objective of this study was to evaluate the atrazine dynamics through determination of the surface runoff and percolation in a Red Latosol cultivated with maize, through studies delineated in drainage lysimeter. Applications of atrazine at the recommended doses were performed weekly up to 44 days after emergence of the maize. Rainfall simulations (150 mm) were performed 24 and 48 h after each application, collecting samples of runoff and percolated water at intervals of 5 min. The samples were sent to the laboratory for analysis of physical and chemical attributes and determination of atrazine concentrations by GC-ECD. Concentrations above the maximum values allowed by the regulatory agencies were found in approximately 99.16% of the obtained samples. The presence of atrazine in runoff and percolated water was recorded. Until 30 days after emergence (DAE) of the crop, higher concentrations of the pesticide were observed in the runoff 24 h after application, mainly in the initial collection minutes. In the percolated samples high concentrations of the pesticide were found even with the development of the crop, however, usually being smaller to those observed for surface runoff. There was a good correlation between the GUS (Groundwater Ubiquity Score) index and the GOSS model and the results obtained. It is concluded that there is the possibility of transporting atrazine in surface runoff and percolation in the different phenological stages of the maize crop when submitted to sequential applications and under high precipitation conditions.","PeriodicalId":265434,"journal":{"name":"Proceedings of the 5th World Congress on New Technologies","volume":"40 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122587681","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Nanocomposite coatings containing metal nanoparticles are receiving increasing interest from both researchers and industry. One of the main properties of the metal nanoparticles that is of interest is their ability to support Localized Surface Plasmon Resonances (LSPRs), optically induced oscillations of free electrons at the surface of the metal nanoparticles. The excitation of LSPRs by incoming light results in strong light extinction effects that are heavily dependent on the nanoparticle’s dielectric constant, size, shape and concentration and also on the dielectric constant of the surrounding medium. Since for each application a specific LSPR signal is needed, it becomes of paramount importance to be able to produce nanocomposites with good control over the nanoparticle’s morphology and over its distribution in the matrix material. Among the various production methods available for obtaining nanostructured coatings, the sputtering technique has become widely used due to its low cost, simplicity in the process, flexibility with the materials and remarkable coating quality. In this work, Au nanoparticles were incorporated into four different matrixes: Al2O3, WO3, TiO2 and AlN. These matrixes have distinct refractive indexes, which allow varying the LSPR throughout the visible region. The LSPR-exhibiting nanocomposites were obtained using three different sputtering techniques, with the aim of obtaining nanocomposites with good control over the nanoparticle’s morphology and distribution in the matrix: (i) co-sputtering followed by thermal annealing treatments up to 500°C; (ii) alternating-sputtering using pulsed DC power sources and (iii) alternating-sputtering using a plasma gas condensation (PGC) nanoparticle source. The first method of deposition allowed achieving nanocomposites with a relatively homogeneous dispersion of spherical Au nanoparticles within the matrixes. The Au integration in the matrix was found to be strongly dependent on the chemistry of the matrix and also on the concentration of noble metal. The application of thermal annealing treatments allowed increasing the Au nanoparticle sizes (up to 8 nm) and also affected the dielectric properties of the matrix. The second method allowed a more effective and independent control over the nanoparticles morphologies without the need of any thermal annealing treatment. Very thin Au layers were deposited, intercalated with the oxides, allowing the formation of Au nanoparticles with different island-type morphologies. With the Au content the mean nanoparticle size increased progressively (up to 15 nm) whereas the shape of the nanoparticles evolved from rather spherical to spheroidal, with decreasing aspect ratios. The decrease in the nanoparticles aspect ratios resulted in more intense and red-shifted LSPR absorption bands. The third method allowed the production of large amounts of nanoparticles with a high level of control over its mean size. Au spherical nanoparticles with sizes betwee
{"title":"How to Use Sputtering for Achieving Nanocomposite Structures","authors":"N. M. Figueiredo, A. Cavaleiro","doi":"10.11159/ICNFA19.01","DOIUrl":"https://doi.org/10.11159/ICNFA19.01","url":null,"abstract":"Nanocomposite coatings containing metal nanoparticles are receiving increasing interest from both researchers and industry. One of the main properties of the metal nanoparticles that is of interest is their ability to support Localized Surface Plasmon Resonances (LSPRs), optically induced oscillations of free electrons at the surface of the metal nanoparticles. The excitation of LSPRs by incoming light results in strong light extinction effects that are heavily dependent on the nanoparticle’s dielectric constant, size, shape and concentration and also on the dielectric constant of the surrounding medium. Since for each application a specific LSPR signal is needed, it becomes of paramount importance to be able to produce nanocomposites with good control over the nanoparticle’s morphology and over its distribution in the matrix material. Among the various production methods available for obtaining nanostructured coatings, the sputtering technique has become widely used due to its low cost, simplicity in the process, flexibility with the materials and remarkable coating quality. In this work, Au nanoparticles were incorporated into four different matrixes: Al2O3, WO3, TiO2 and AlN. These matrixes have distinct refractive indexes, which allow varying the LSPR throughout the visible region. The LSPR-exhibiting nanocomposites were obtained using three different sputtering techniques, with the aim of obtaining nanocomposites with good control over the nanoparticle’s morphology and distribution in the matrix: (i) co-sputtering followed by thermal annealing treatments up to 500°C; (ii) alternating-sputtering using pulsed DC power sources and (iii) alternating-sputtering using a plasma gas condensation (PGC) nanoparticle source. The first method of deposition allowed achieving nanocomposites with a relatively homogeneous dispersion of spherical Au nanoparticles within the matrixes. The Au integration in the matrix was found to be strongly dependent on the chemistry of the matrix and also on the concentration of noble metal. The application of thermal annealing treatments allowed increasing the Au nanoparticle sizes (up to 8 nm) and also affected the dielectric properties of the matrix. The second method allowed a more effective and independent control over the nanoparticles morphologies without the need of any thermal annealing treatment. Very thin Au layers were deposited, intercalated with the oxides, allowing the formation of Au nanoparticles with different island-type morphologies. With the Au content the mean nanoparticle size increased progressively (up to 15 nm) whereas the shape of the nanoparticles evolved from rather spherical to spheroidal, with decreasing aspect ratios. The decrease in the nanoparticles aspect ratios resulted in more intense and red-shifted LSPR absorption bands. The third method allowed the production of large amounts of nanoparticles with a high level of control over its mean size. Au spherical nanoparticles with sizes betwee","PeriodicalId":265434,"journal":{"name":"Proceedings of the 5th World Congress on New Technologies","volume":"12 1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116832637","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This document studies graphically, through cluster groups, 17 countries in Europe and South America, generating an order with respect to different variables of public spending, education, environmental, public security, this in order to know the relationship they have with the Carbon Dioxide emissions variable, and generate a multivariate appreciation, using a comparison between the HJBiplot methods of the MulBiplot software, Clustering Biplot and Clustering Disjoint Biplot, using the RStudio software. The clusters obtained allow us to interpret in a broader context the relationship and variability of each country in relation to a set of variables, and to know the homogeneity between countries. In conclusion, using the three grouping methods with certain similarities since all three use the HJ-Biplot within their processes, but differ in others, it was possible to observe how the carbon dioxide emissions, considered as one of the gases causing the greenhouse effect maintains a positive relationship with the economic growth of the countries represented by the GDP per capita, since in the three groups by cluster both variables remain always related, while the variable of Expenditure in Research presents a positive relationship also with respect to these variables, however in the CDBiplot is part of a different factorial axis than the other two variables.
{"title":"Carbon Dioxide Emissions. A Multivariate Analysis HJ-Biplot, Clustering Biplot and Clustering Disjoint Biplot","authors":"Pilacuan Bonete Luis, Galindo Villardon Purificación","doi":"10.11159/ICEPR19.160","DOIUrl":"https://doi.org/10.11159/ICEPR19.160","url":null,"abstract":"This document studies graphically, through cluster groups, 17 countries in Europe and South America, generating an order with respect to different variables of public spending, education, environmental, public security, this in order to know the relationship they have with the Carbon Dioxide emissions variable, and generate a multivariate appreciation, using a comparison between the HJBiplot methods of the MulBiplot software, Clustering Biplot and Clustering Disjoint Biplot, using the RStudio software. The clusters obtained allow us to interpret in a broader context the relationship and variability of each country in relation to a set of variables, and to know the homogeneity between countries. In conclusion, using the three grouping methods with certain similarities since all three use the HJ-Biplot within their processes, but differ in others, it was possible to observe how the carbon dioxide emissions, considered as one of the gases causing the greenhouse effect maintains a positive relationship with the economic growth of the countries represented by the GDP per capita, since in the three groups by cluster both variables remain always related, while the variable of Expenditure in Research presents a positive relationship also with respect to these variables, however in the CDBiplot is part of a different factorial axis than the other two variables.","PeriodicalId":265434,"journal":{"name":"Proceedings of the 5th World Congress on New Technologies","volume":"23 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123668221","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
T. Tabakova, I. Ivanov, J. Sobczak, W. Lisowski, Z. Kaszkur, R. Zanella, P. Petrova, Y. Karakirova, L. Ilieva
The increasing demands for high-purity hydrogen for fuel-cell processing systems caused a renewed interest in the watergas shift reaction. This work aims to analyse the suitability of goldand copper-based catalysts for efficient upgrading the purity of hydrogen for small-scale applications. New catalytic materials were developed by deposition of nanosized gold or copper oxide particles on ceria doped by various amount of Y2O3 (1.0, 2.5 and 5.0 wt.%). A favourable effect of the ceria modification on the WGS activity of gold/ceria catalysts was observed. Superior CO conversion degrees (> 95 %) were achieved in the range 180-220 °C. The similarity in the catalytic activity was explained with the insignificant differences in the gold particle size among all gold-based samples. Surprisingly, copper-based catalysts exhibited decreased activity at increasing amount of Y2O3 in the composition of ceria supports. A characterization of the catalysts by N2 physisorption, XRD, HRTEM/HAADF, XPS, EPR and H2-TPR was carried out to reveal the effect of dopant amount on the WGS activity. The differences in the WGS performance were related to the catalysts reducibility, e.g. the availability of oxygen species with enhanced mobility. The analysis of structure-property-WGS activity relations proved to be a reliable tool for the improvement of catalyst performance by rational changes in the catalyst composition and structure.
{"title":"A Comparative Study of Nanosized Gold and Copper Catalysts on Y-doped Ceria for the Water-Gas Shift Reaction","authors":"T. Tabakova, I. Ivanov, J. Sobczak, W. Lisowski, Z. Kaszkur, R. Zanella, P. Petrova, Y. Karakirova, L. Ilieva","doi":"10.11159/ICNFA19.140","DOIUrl":"https://doi.org/10.11159/ICNFA19.140","url":null,"abstract":"The increasing demands for high-purity hydrogen for fuel-cell processing systems caused a renewed interest in the watergas shift reaction. This work aims to analyse the suitability of goldand copper-based catalysts for efficient upgrading the purity of hydrogen for small-scale applications. New catalytic materials were developed by deposition of nanosized gold or copper oxide particles on ceria doped by various amount of Y2O3 (1.0, 2.5 and 5.0 wt.%). A favourable effect of the ceria modification on the WGS activity of gold/ceria catalysts was observed. Superior CO conversion degrees (> 95 %) were achieved in the range 180-220 °C. The similarity in the catalytic activity was explained with the insignificant differences in the gold particle size among all gold-based samples. Surprisingly, copper-based catalysts exhibited decreased activity at increasing amount of Y2O3 in the composition of ceria supports. A characterization of the catalysts by N2 physisorption, XRD, HRTEM/HAADF, XPS, EPR and H2-TPR was carried out to reveal the effect of dopant amount on the WGS activity. The differences in the WGS performance were related to the catalysts reducibility, e.g. the availability of oxygen species with enhanced mobility. The analysis of structure-property-WGS activity relations proved to be a reliable tool for the improvement of catalyst performance by rational changes in the catalyst composition and structure.","PeriodicalId":265434,"journal":{"name":"Proceedings of the 5th World Congress on New Technologies","volume":"54 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114196467","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Electromobility is a set of activities related to the use of electric vehicles, as well as technical and operational EV solutions, technologies and charging infrastructure, as well as social, economic and legal issues pertaining to the designing, manufacturing, purchasing and using electric vehicles. The article presents results of the survey on e-mobility infrastructure in the GórnośląskoZagłębiowska Metropolis, Poland, and potential for development.
{"title":"E-mobility Infrastructure in the Górnośląsko - Zagłębiowska Metropolis, Poland, and Potential for Development","authors":"E. Macioszek","doi":"10.11159/ICERT19.108","DOIUrl":"https://doi.org/10.11159/ICERT19.108","url":null,"abstract":"Electromobility is a set of activities related to the use of electric vehicles, as well as technical and operational EV solutions, technologies and charging infrastructure, as well as social, economic and legal issues pertaining to the designing, manufacturing, purchasing and using electric vehicles. The article presents results of the survey on e-mobility infrastructure in the GórnośląskoZagłębiowska Metropolis, Poland, and potential for development.","PeriodicalId":265434,"journal":{"name":"Proceedings of the 5th World Congress on New Technologies","volume":"42 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121444912","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
J. Segura-Ruíz, R. Tucoulou, J. Villanova, Damien SalomonJoel Eymery, G. Martínez-Criado
Extended Abstract Nanomaterials and nano-devices are continuously evolving. This continuous evolution requires powerful characterization techniques to better understand and further improve the properties of the materials and the performances of the devices. The advanced characterization tools provided by synchrotron installations can play an important role in these R&D processes. Here, the compositional and optical properties of NW-based InGaN coaxial nano-Light Emitting Diodes will be studied using the ID16B hard X-ray nanoprobe beamline. The ID16B beamline at the European Synchrotron Radiation Facility (ESRF) [1] is a nano-probe that provides a focused (down to 50x50 nm), intense (up to 10 ph/s), hard X-rays (up to 33 keV) beam. ID16B offers several characterization techniques and diverse sample environments. In this study we will use X-ray fluorescence (XRF) and X-ray excited optical luminescence (XEOL) simultaneously to characterize at Liquid-He temperature InGaN/GaN coaxial nano-LEDs. The coaxial LED heterostructure was fabricated by metalorganic vapour phase epitaxy and consists of an inner n-doped GaN core (∼2 μm diameter) with five periods of InxGa1-xN/GaN MQWs shell (1.25-nm-thick InGaN well with ∼15% In concentration and 10-nm-thick GaN barrier) [2]. The nano-LEDs were dispersed on a Si substrate and pre-localized with the help of a Scanning Electron Microscope. The Si-substrate was then mounted on a liquid-He mini-cryostat compatible with the experimental setup available on the beamline ID16B and cooled down to 6 K. The sample was scanned with the 50x50 nm beam and the XRF and and XEOL signals were collected simultaneously. Both, XRF and XEOL signals were analysed using the PyMCA software [3] in order to obtain elemental and emission correlated maps. The combined use of XRF and XEOL techniques with the He-cryostat available on ID16B provided unique space-resolved information to clarify the interplay between the compositional and optical properties of these nano-devices at the nanometre scale. The sharpness of the emission features observed in the XEOL spectra thanks to the very low temperatures provided by the He-cryostat allowed the visualization nanometre sized regions of the device having very localized emission with different peak energies. This emission-energyallowed filtering was used to localize quantum-dot like regions within In-rich regions at the bottom of the coaxial LEDs, in the area where the deposition of the InGaN/GaN MQWs shell was not completed. The direct comparison between the XRF and the XEOL maps allowed to attribute this emission to InGaN nuclei with different In-concentrations in the range between x=0.01 to x=0.4. These results demonstrate the power of ID16B as a characterization tool for the study of complex nanomaterials and single nano-devices.
{"title":"ID16B Beamline at the ESRF: a Nanoprobe for the Characterization of Nanomaterials and Nanodevices","authors":"J. Segura-Ruíz, R. Tucoulou, J. Villanova, Damien SalomonJoel Eymery, G. Martínez-Criado","doi":"10.11159/ICNFA19.121","DOIUrl":"https://doi.org/10.11159/ICNFA19.121","url":null,"abstract":"Extended Abstract Nanomaterials and nano-devices are continuously evolving. This continuous evolution requires powerful characterization techniques to better understand and further improve the properties of the materials and the performances of the devices. The advanced characterization tools provided by synchrotron installations can play an important role in these R&D processes. Here, the compositional and optical properties of NW-based InGaN coaxial nano-Light Emitting Diodes will be studied using the ID16B hard X-ray nanoprobe beamline. The ID16B beamline at the European Synchrotron Radiation Facility (ESRF) [1] is a nano-probe that provides a focused (down to 50x50 nm), intense (up to 10 ph/s), hard X-rays (up to 33 keV) beam. ID16B offers several characterization techniques and diverse sample environments. In this study we will use X-ray fluorescence (XRF) and X-ray excited optical luminescence (XEOL) simultaneously to characterize at Liquid-He temperature InGaN/GaN coaxial nano-LEDs. The coaxial LED heterostructure was fabricated by metalorganic vapour phase epitaxy and consists of an inner n-doped GaN core (∼2 μm diameter) with five periods of InxGa1-xN/GaN MQWs shell (1.25-nm-thick InGaN well with ∼15% In concentration and 10-nm-thick GaN barrier) [2]. The nano-LEDs were dispersed on a Si substrate and pre-localized with the help of a Scanning Electron Microscope. The Si-substrate was then mounted on a liquid-He mini-cryostat compatible with the experimental setup available on the beamline ID16B and cooled down to 6 K. The sample was scanned with the 50x50 nm beam and the XRF and and XEOL signals were collected simultaneously. Both, XRF and XEOL signals were analysed using the PyMCA software [3] in order to obtain elemental and emission correlated maps. The combined use of XRF and XEOL techniques with the He-cryostat available on ID16B provided unique space-resolved information to clarify the interplay between the compositional and optical properties of these nano-devices at the nanometre scale. The sharpness of the emission features observed in the XEOL spectra thanks to the very low temperatures provided by the He-cryostat allowed the visualization nanometre sized regions of the device having very localized emission with different peak energies. This emission-energyallowed filtering was used to localize quantum-dot like regions within In-rich regions at the bottom of the coaxial LEDs, in the area where the deposition of the InGaN/GaN MQWs shell was not completed. The direct comparison between the XRF and the XEOL maps allowed to attribute this emission to InGaN nuclei with different In-concentrations in the range between x=0.01 to x=0.4. These results demonstrate the power of ID16B as a characterization tool for the study of complex nanomaterials and single nano-devices.","PeriodicalId":265434,"journal":{"name":"Proceedings of the 5th World Congress on New Technologies","volume":"24 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132111295","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Extended Abstract Hydrogen (H2) has been considered as a clean and environment-friendly energy source on account of its low ignition energy and high heat of combustion from which the combustion product is H2O.[1] Recently, H2 gas is regarded as the most important energy source for the operation of electrical vehicles.[2, 3] However, H2 is not only flammable but also explosive in the concentration of 4-75%. Unfortunately, it is impossible to detect H2 gas by human beings because of its colorless and odorless property. Therefore, a development of sensitive H2 gas sensor is required for human safety.[4,5] Two-dimensional electron gas (2DEG) was observed at the interface of oxide heterostructure in 2004.[6] The model system for 2DEG at the oxide heterostructure is epitaxial interface of LaAlO3/SrTiO3 heterostructure. Recently, we reported that 2DEG can be created at the oxide heterostructure by using amorphous Al2O3 top layer.[7] Here, we demonstrate highperformance H2 gas sensor using 2DEG at the interface of Al2O3/SrTiO3 heterostructure using atomic layer deposition (ALD). Palladium (Pd) or platinum (Pt) catalysts are used on top of the Al2O3/SrTiO3 heterostructure.[8] At first, we will show a H2 gas sensing performance using 2DEG at the interface of Al2O3/SrTiO3 heterostructure. The H2 gas sensor using Al2O3/SrTiO3 exhibited a wide sensing range of H2 concentration (5ppm-1%) even room temperature with fast response time. The more H2 gas concentration increased, the more H2 gas sensitive increased. The Pd/Al2O3/SrTiO3 sensor showed a fast response time to detect H2 gas (<30 s) at room temperature. Owing to a wide bandgap (>3.2 eV) of Al2O3/SrTiO3, a transparent gas sensor (transmittance >83% in the visible spectrum) was realized. 2DEG resistance is changed by adsorbing H2 gas because the work function of Pd nanoparticles is modulated by the H2 adsorption. Alteration of work function induced the change of the 2DEG resistance. The detailed detection principle will be explained in the presentation. H2 gas sensor using 2DEG at heterostructure such as AlGaN/GaN is another candidate for H2 detection, thus, H2 sensor using AlGaN/GaN is compared with Al2O3/SrTiO3 sensor. H2 gas sensor using AlGaN/GaN heterostructure showed a slow H2 detection speed, but superior sensitivity (~30000%) compared to the Al2O3/SrTiO3 sensor. In addition, enhanced detection performances of H2 gas sensor with AlGaN/GaN heterostructures using atomic-layer-thick ZnO on Pt (or Pd) on 2DEG are addressed, which improved a decrease of recovery time. The atomic-layer-thick ZnO layer was grown by ALD which will be introduced in the presentation.
{"title":"Hydrogen Gas Sensors Using Two-Dimensional Electron Gas","authors":"Se Eun Kim, Hye Ju Kim, Sang Woon Lee","doi":"10.11159/ICNFA19.137","DOIUrl":"https://doi.org/10.11159/ICNFA19.137","url":null,"abstract":"Extended Abstract Hydrogen (H2) has been considered as a clean and environment-friendly energy source on account of its low ignition energy and high heat of combustion from which the combustion product is H2O.[1] Recently, H2 gas is regarded as the most important energy source for the operation of electrical vehicles.[2, 3] However, H2 is not only flammable but also explosive in the concentration of 4-75%. Unfortunately, it is impossible to detect H2 gas by human beings because of its colorless and odorless property. Therefore, a development of sensitive H2 gas sensor is required for human safety.[4,5] Two-dimensional electron gas (2DEG) was observed at the interface of oxide heterostructure in 2004.[6] The model system for 2DEG at the oxide heterostructure is epitaxial interface of LaAlO3/SrTiO3 heterostructure. Recently, we reported that 2DEG can be created at the oxide heterostructure by using amorphous Al2O3 top layer.[7] Here, we demonstrate highperformance H2 gas sensor using 2DEG at the interface of Al2O3/SrTiO3 heterostructure using atomic layer deposition (ALD). Palladium (Pd) or platinum (Pt) catalysts are used on top of the Al2O3/SrTiO3 heterostructure.[8] At first, we will show a H2 gas sensing performance using 2DEG at the interface of Al2O3/SrTiO3 heterostructure. The H2 gas sensor using Al2O3/SrTiO3 exhibited a wide sensing range of H2 concentration (5ppm-1%) even room temperature with fast response time. The more H2 gas concentration increased, the more H2 gas sensitive increased. The Pd/Al2O3/SrTiO3 sensor showed a fast response time to detect H2 gas (<30 s) at room temperature. Owing to a wide bandgap (>3.2 eV) of Al2O3/SrTiO3, a transparent gas sensor (transmittance >83% in the visible spectrum) was realized. 2DEG resistance is changed by adsorbing H2 gas because the work function of Pd nanoparticles is modulated by the H2 adsorption. Alteration of work function induced the change of the 2DEG resistance. The detailed detection principle will be explained in the presentation. H2 gas sensor using 2DEG at heterostructure such as AlGaN/GaN is another candidate for H2 detection, thus, H2 sensor using AlGaN/GaN is compared with Al2O3/SrTiO3 sensor. H2 gas sensor using AlGaN/GaN heterostructure showed a slow H2 detection speed, but superior sensitivity (~30000%) compared to the Al2O3/SrTiO3 sensor. In addition, enhanced detection performances of H2 gas sensor with AlGaN/GaN heterostructures using atomic-layer-thick ZnO on Pt (or Pd) on 2DEG are addressed, which improved a decrease of recovery time. The atomic-layer-thick ZnO layer was grown by ALD which will be introduced in the presentation.","PeriodicalId":265434,"journal":{"name":"Proceedings of the 5th World Congress on New Technologies","volume":"34 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134524696","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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