Suchergebnisse

This paper has been presented at the 25th International Conference on Electricity Distribution (CIRED 2019). ; The so-called 20-20-20 targets committed to by the European Union drives the need for a more efficient distribution network. The energy efficiency improvement required involves a 20% reduction of the energy consumption compared to the 1990s. For such cutback, Distribution Systems Operators are encouraged to develop the best strategies to identify and reduce power losses in their networks. This task becomes challenging in Low Voltage Distribution networks due to diversity in the feeder's topology configuration, load distribution and the presence of renewable-based distributed generation. In this paper, a clustering-based methodology is proposed as an energy losses tool to support the energy efficiency decision-making process. A feeder's clustering process using the K-means algorithm is carried out upon a customised network characteristics set that was previously reduced to two coordinates by applying Principal Component Analysis. The relationship between power losses and the net energy imported under the different scenarios is obtained for each feeder class identified. The data and network used in this process correspond to the roll-out deployed at the Spanish Smart Grid Demonstration Project (OSIRIS) ; This work has been partly funded by the Spanish Ministry of Economy and Competitiveness through the National Program for Research Aimed at the Challenges of Society under the project OSIRIS (RTC-2014-1556-3).

Proceedings of: III Ibero-American Conference on Smart Cities (ICSC-CITIES 2020) ; Environmental concerns, such as global warming and scarcity of natural resources, pressure companies to develop and adopt cleaner technologies and production processes. Besides, the search for sustainable development (as recommended by Agenda 2030 from the United Nations) has made companies rethink their whole supply chain, including transport activities. Besides, governments have been proposing public policies to obtain positive impacts in the economic, social and environmental dimensions. In this context, many studies have pointed out that electric mobility is a sustainable alternative to the transport sector and, in many EU countries, the government has bet on subsidies to attract manufacturers and customers to this market. Therefore, this paper aims to identify the role of electric vehicles (EV) in sustainable supply chains, considering the articles published in the Web of Science (WoS) database. We realize that there is a low quantity of papers dedicated to investigating the EV in this context. Many papers claim to perform sustainable analysis but do not evaluate the triple bottom line's three dimensions. Nevertheless, we identified that governments had developed policies to incentivize the introduction of electric vehicles in the market. ; The authors thank CNPq for the scientific initiation scholarship and IFRJ for lending the software Vantage Point. CYTED Thematic Network "Ciudades Inteligentes Totalmente Integrales, Eficientes Y Sostenibles (CITIES)" no 518RT0558.

Over the last decades, active power networks have reached great attention due to the incorporation of distributed energy resources into low voltage power systems. In this paper, a decentralized energy management strategy is proposed as an efficient way to minimize both active power losses and voltage profile deviation of an distribution power network with photovoltaic solar farms, and also at the same time, aims to improve the reliability and the security of supply. The coordinated energy management concept relies on a two-step optimization approach based on genetic algorithms (GA) and MINLP, in which a multi-objective function is used which takes into account reliability and operational technical constraints in its formulation. The suitability of the proposed methodology is tested on an existing low voltage power system, in which two aspects are considered: firstly, determining the optimal allocation of PV units and secondly, establishing the optimal reschedule of the active power of the generation units partic ipating in the energy mix and minimizing both the real power losses and voltage deviation of the entire power system. ; This work has been partly funded by the European Union seventh framework program FP7-SMARTCITIES-2013 under grant agreement 608860 IDE4L – Ideal grid for all.

Recently, the distribution networks are working close to their physical device limits. When congestion takes place, distributed switches can be controlled to change their status in order to find a new optimal network configuration that solves that congestion. In this paper, a new methodology for congestion management by means of distributed network reconfiguration is presented. Switches and controllable voltage units such as PV units were used in the optimization process. The optimization process is guided by a weighted objective function that takes into account real power losses as well as operational limits of the power system under study. The methodology is tested in an Italian real power distribution system. ; The research leading to these results has received funding from the European Union seventh framework program FP7-SMARTCITIES-2013 under grant agreement 608860 IDE4L – Ideal grid for all.

AP2010-5857, MOE, Ministry of Education ; This work was supported by the Ministry of Science and Innovation of the Spanish Government, (Projects AGL2007-62907 and AGL2011-27904) ; The authors wish to thank Dr. Mario F. Fraga and Dr. Agustín Fernandez for their helpful comments. This work was supported by the Ministry of Science and Innovation of the Spanish Government (AGL2011-27904). LV and MM were funded by Juan de la Cierva Programme (Spanish Ministry of Economy and Competitiveness, ref. JCI-2012-12444 and JCI-2011-08958, respectively). ME and JP fellowships were respectively supported by Severo Ochoa (Gobierno del Principado de Asturias, Spain, ref. BP11117) and FPU (Ministry of Education, Spain, ref. AP2010-5857) grants.

Effects of altering the properties of an active site in an enzymatic homogeneous catalyst have been extensively reported. However, the possibility of increasing the number of such sites, as commonly done in heterogeneous catalytic materials, remains unexplored, particularly because those have to accommodate appropriate residues in specific configurations. This possibility was investigated by using a serine ester hydrolase as the target enzyme. By using the Protein Energy Landscape Exploration software, which maps ligand diffusion and binding, we found a potential binding pocket capable of holding an extra catalytic triad and oxyanion hole contacts. By introducing two mutations, this binding pocket became a catalytic site. Its substrate specificity, substrate preference, and catalytic activity were different from those of the native site of the wild type ester hydrolase and other hydrolases, due to the differences in the active site architecture. Converting the binding pocket into an extra catalytic active site was proven to be a successful approach to create a serine ester hydrolase with two functional reactive groups. Our results illustrate the accuracy and predictive nature of modern modeling techniques, opening novel catalytic opportunities coming from the presence of different catalytic environments in single enzymes. ; This project received funding from the European Union's Horizon 2020 research and innovation program [Blue Growth: Unlocking the potential of Seas and Oceans] under grant agreement no. [634486] (project acronym INMARE). This research was also supported by the grants PCIN-2014-107 (within ERA NET IB2 grant nr. ERA-IB-14-030 - MetaCat), PCIN-2017-078 (within the ERA-MarineBiotech grant ProBone), BIO2014-54494-R, CTQ2016-79138-R and BIO2017-85522-R from the Spanish Ministry of Economy, Industry and Competitiveness. P.N.G. gratefully acknowledges funding from the UK Biotechnology and Biological Sciences Research Council (grant no. BB/M029085/1). R.B. and P.N.G. acknowledge the support of the Supercomputing Wales project, which is part-funded by the European Regional De-velopment Fund (ERDF) via Welsh Government. P.N.G. acknowledges the support of the Centre of Environmental Biotechnology Project funded by the European Regional Development Fund (ERDF) through Welsh Government. The authors gratefully acknowledge financial support provided by the European Regional Development Fund (ERDF). The MALDI-TOF/TOF analysis was performed in the proteomics facility of the Spanish National Center for Biotechnology (CNB-CSIC) that belongs to ProteoRed, PRB2-ISCIII, sup-ported by grant PT13/0001. ; Peer Reviewed ; Postprint (published version)

Effects of altering the properties of an active site in an enzymatic homogeneous catalyst have been extensively reported. However, the possibility of increasing the number of such sites, as commonly done in heterogeneous catalytic materials, remains unexplored, particularly because those have to accommodate appropriate residues in specific configurations. This possibility was investigated by using a serine ester hydrolase as the target enzyme. By using the Protein Energy Landscape Exploration software, which maps ligand diffusion and binding, we found a potential binding pocket capable of holding an extra catalytic triad and oxyanion hole contacts. By introducing two mutations, this binding pocket became a catalytic site. Its substrate specificity, substrate preference, and catalytic activity were different from those of the native site of the wild type ester hydrolase and other hydrolases, due to the differences in the active site architecture. Converting the binding pocket into an extra catalytic active site was proven to be a successful approach to create a serine ester hydrolase with two functional reactive groups. Our results illustrate the accuracy and predictive nature of modern modeling techniques, opening novel catalytic opportunities coming from the presence of different catalytic environments in single enzymes. ; This project received funding from the European Union's Horizon 2020 research and innovation program [Blue Growth: Unlocking the potential of Seas and Oceans] under grant agreement no. [634486] (project acronym INMARE). This research was also supported by the grants PCIN-2014-107 (within ERA NET IB2 grant nr. ERA-IB-14-030 - MetaCat), PCIN-2017-078 (within the ERA-MarineBiotech grant ProBone), BIO2014-54494-R, CTQ2016-79138-R and BIO2017-85522-R from the Spanish Ministry of Economy, Industry and Competitiveness. P.N.G. gratefully acknowledges funding from the UK Biotechnology and Biological Sciences Research Council (grant no. BB/M029085/1). R.B. and P.N.G. acknowledge the support of the Supercomputing Wales project, which is part-funded by the European Regional De-velopment Fund (ERDF) via Welsh Government. P.N.G. acknowledges the support of the Centre of Environmental Biotechnology Project funded by the European Regional Development Fund (ERDF) through Welsh Government. The authors gratefully acknowledge financial support provided by the European Regional Development Fund (ERDF). The MALDI-TOF/TOF analysis was performed in the proteomics facility of the Spanish National Center for Biotechnology (CNB-CSIC) that belongs to ProteoRed, PRB2-ISCIII, sup-ported by grant PT13/0001. ; Peer Reviewed ; Postprint (published version)

This publication is an output of the projects financed by the Spanish Ministry of Economy, Industry and Competitiveness (AGL2014-54995-P and AGL2016-77633-P), the Government of Principado de Asturias (GRUPIN14-055), FEDER funding through COMPETE (Project: UID/AMB/50017/2013), and by National Funds through the Portuguese Foundation for Science and Technology (FCT) within the Project PTDC/AGRFOR/2768/2014. ME was supported by a fellowship from the Severo Ochoa Program (BP11117; Government of Principado de Asturias, Spain). JP was supported by a fellowship from the FPU (AP2010-5857; Ministry of Education, Spain). FCT (Fundação para a Ciência e a Tecnologia, Portugal) supported the fellowships of GP (SFRH/BPD/101669/2014). The Spanish Ministry of Economy and Competitiveness supported MM and LV through the Ramón y Cajal program (RYC-2014-14981 and RYC-2015-17871, respectively). FCT/MEC (Portugal) co-funding by the FEDER, within the PT2020 Partnership Agreement and Compete 2020 provide financial support to Centre for Environmental and Marine Studies (CESAM –UID/AMB/50017).

This publication is an output of the Department of Biology of the University of Aveiro (Portugal) and Czechglobe Centre (Czech Republic). This work was financed by National Funds through the Portuguese Science Foundation (FCT) within project EXPL/AAG-TEC/2056/2013 and PEst-C/MAR/LA0017/2013, and by the European Union with the support of COMPETE (U. Aveiro) and MEYS CR Re. CZ.1.07/2.3.00/20.0256 (Czechglobe). LV was sup- ported by FCT (SFRH/BPD/89765/2012) or EU (CZ.1.07/2.3.00/20.0256), ME by Severo Ochoa Programme (BP11117, Gobierno del Principado de Asturias, Spain), MM by the Spanish Government (Juan de la Cierva Programme, JCI-2011-08958), and EN by the EU-Marie-Curie ITN MERIT (GA 2010-264474).

It is thought that during immobilization enzymes, as dynamic biomolecules, may become distorted and this may alter their catalytic properties. However, the effects of different immobilization strategies on enzyme rigidity or flexibility and their consequences in specificity and stereochemistry at large scale has not been yet clearly evaluated and understood. This was here investigated by using as model an ester hydrolase, isolated from a bacterium inhabiting a karstic lake, with broad substrate spectrum (72 esters being converted; 61.5 U mg−1 for glyceryl tripropionate) but initially non-enantiospecific. We found that the enzyme (7 nm × 4.4 nm × 4.2 nm) could be efficiently ionic exchanged inside the pores (9.3 nm under dry conditions) of amino-functionalized ordered mesoporous material (NH2-SBA-15), achieving a protein load of 48 mg g−1, and a specific activity of 4.5 ± 0.1 U mg−1. When the enzyme was site-directed immobilized through His interaction with an immobilized cationon the surface of two types of magnetic micro-particles through hexahistidine-tags, protein loads up to 10.2 μg g−1 and specific activities of up to 29.9 ± 0.3 U mg−1, were obtained. We found that ionically exchanged enzyme inside pores of NH2-SBA-15 drastically narrowed the substrate range (17 esters), to an extent much higher than ionically exchanged enzyme on the surface of magnetic micro-particles (up to 61 esters). This is attributed to differences in surface chemistry, particle size, and substrate accessibility to the active site tunnel. Our results also suggested, for the first time, that immobilization of enzymes in pores of similar size may alter the enzyme structures and produce enzyme active centers with different configuration which promote stereochemical conversions in a manner different to those arising from surface immobilization, where the strength of the ionic exchange also has an influence. This was shown by demonstrating that when the enzyme was introduced inside pores with a diameter (under dry conditions) slightly higher than that of the enzyme crystal structure a biocatalyst enantiospecific for ethyl (R)-4-chloro-3-hydroxybutyrate was produced, a feature not found when using wider pores. By contrast, immobilization on the surface of ferromagnetic microparticles produced selective biocatalysts for methyl (S)-(+)-mandelate or methyl (S)-lactate depending on the functionalization. This study illustrates the benefits of extensive analysis of the substrate spectra to better understand the effects of different immobilization strategies on enzyme flexibility/rigidity, as well as substrate specificity and stereochemistry. Our results will help to design tunable materials and interfaces for a controlled manipulation of specificity and to transform non-enantiospecific enzymes into stereo-chemically substrate promiscuous biocatalysts capable of converting multiple chiral molecules. ; This project received funding from the European Union's Horizon 2020 research and innovation program Blue Growth: Unlockingthe potential of Seas and Oceans under grant agreement no. 634486 (project acronym INMARE). This research was also supported by the grants PCIN-2014-107 (within ERA NET IB2 grant nr. ERA-IB-14-030 - MetaCat), PCIN-2017-078 (within the ERA-MarineBiotech grant ProBone), BIO2014-54494-R, MAT2016-77496-R, BIO2017-85522-R, and CTQ2016-79138-R from the Spanish Ministry of Economy, Industry and Competitiveness. A.B. acknowledges the support from the Spanish Ministry of Economy, Industry and Competitiveness (MAT2017-88808-R grant), María de Maeztu Units of Excellence Programme (MDM-2016-0618), and the Diputación de Guipúzcoa for current funding in the frame of Gipuzkoa Fellows program. G.D. thanks the German Federal Ministry of Education and Research (BMBF, Grant No. 031A095C) for funding in the frame of the Molecular Interaction Engineering program (Biotechnologie 2020+). The authors gratefully acknowledge financial support provided by the European Regional Development Fund (ERDF). C.C. thanks the Spanish Ministry of Economy, Industry and Competitiveness for a PhD fellowship (Grant BES-2015-073829). ; Peer Reviewed ; Postprint (published version)

It is thought that during immobilization enzymes, as dynamic biomolecules, may become distorted and this may alter their catalytic properties. However, the effects of different immobilization strategies on enzyme rigidity or flexibility and their consequences in specificity and stereochemistry at large scale has not been yet clearly evaluated and understood. This was here investigated by using as model an ester hydrolase, isolated from a bacterium inhabiting a karstic lake, with broad substrate spectrum (72 esters being converted; 61.5 U mg−1 for glyceryl tripropionate) but initially non-enantiospecific. We found that the enzyme (7 nm × 4.4 nm × 4.2 nm) could be efficiently ionic exchanged inside the pores (9.3 nm under dry conditions) of amino-functionalized ordered mesoporous material (NH2-SBA-15), achieving a protein load of 48 mg g−1, and a specific activity of 4.5 ± 0.1 U mg−1. When the enzyme was site-directed immobilized through His interaction with an immobilized cationon the surface of two types of magnetic micro-particles through hexahistidine-tags, protein loads up to 10.2 μg g−1 and specific activities of up to 29.9 ± 0.3 U mg−1, were obtained. We found that ionically exchanged enzyme inside pores of NH2-SBA-15 drastically narrowed the substrate range (17 esters), to an extent much higher than ionically exchanged enzyme on the surface of magnetic micro-particles (up to 61 esters). This is attributed to differences in surface chemistry, particle size, and substrate accessibility to the active site tunnel. Our results also suggested, for the first time, that immobilization of enzymes in pores of similar size may alter the enzyme structures and produce enzyme active centers with different configuration which promote stereochemical conversions in a manner different to those arising from surface immobilization, where the strength of the ionic exchange also has an influence. This was shown by demonstrating that when the enzyme was introduced inside pores with a diameter (under dry conditions) slightly higher than that of the enzyme crystal structure a biocatalyst enantiospecific for ethyl (R)-4-chloro-3-hydroxybutyrate was produced, a feature not found when using wider pores. By contrast, immobilization on the surface of ferromagnetic microparticles produced selective biocatalysts for methyl (S)-(+)-mandelate or methyl (S)-lactate depending on the functionalization. This study illustrates the benefits of extensive analysis of the substrate spectra to better understand the effects of different immobilization strategies on enzyme flexibility/rigidity, as well as substrate specificity and stereochemistry. Our results will help to design tunable materials and interfaces for a controlled manipulation of specificity and to transform non-enantiospecific enzymes into stereo-chemically substrate promiscuous biocatalysts capable of converting multiple chiral molecules. ; This project received funding from the European Union's Horizon 2020 research and innovation program Blue Growth: Unlockingthe potential of Seas and Oceans under grant agreement no. 634486 (project acronym INMARE). This research was also supported by the grants PCIN-2014-107 (within ERA NET IB2 grant nr. ERA-IB-14-030 - MetaCat), PCIN-2017-078 (within the ERA-MarineBiotech grant ProBone), BIO2014-54494-R, MAT2016-77496-R, BIO2017-85522-R, and CTQ2016-79138-R from the Spanish Ministry of Economy, Industry and Competitiveness. A.B. acknowledges the support from the Spanish Ministry of Economy, Industry and Competitiveness (MAT2017-88808-R grant), María de Maeztu Units of Excellence Programme (MDM-2016-0618), and the Diputación de Guipúzcoa for current funding in the frame of Gipuzkoa Fellows program. G.D. thanks the German Federal Ministry of Education and Research (BMBF, Grant No. 031A095C) for funding in the frame of the Molecular Interaction Engineering program (Biotechnologie 2020+). The authors gratefully acknowledge financial support provided by the European Regional Development Fund (ERDF). C.C. thanks the Spanish Ministry of Economy, Industry and Competitiveness for a PhD fellowship (Grant BES-2015-073829). ; Peer Reviewed ; Postprint (published version)

Congestion management is one of the core enablers of smart distribution systems where distributed energy resources are utilised in network control to enable cost-effective network interconnection of distributed generation (DG) and better utilisation of network assets. The primary aim of congestion management is to prevent voltage violations and network overloading. Congestion management algorithms can also be used to optimise the network state. This study proposes a hierarchical and distributed congestion management concept for future distribution networks having large-scale DG and other controllable resources in MV and LV networks. The control concept aims at operating the network at minimum costs while retaining an acceptable network state. The hierarchy consists of three levels: primary controllers operate based on local measurements, secondary control optimises the set points of the primary controllers in real-time and tertiary control utilises load and production forecasts as its inputs and realises network reconfiguration algorithm and connection to the market. Primary controllers are located at the connection point of the controllable resource, secondary controllers at primary and secondary substations and tertiary control at the control centre. Hence, the control is spatially distributed and operates in different time frames. ; The research leading to these results has received funding from the European Union seventh framework program FP7-SMARTCITIES-2013 under grant agreement 608860 IDE4L – Ideal grid for all.

El Arroyo Caañabe, es un curso de agua que corre a través de los Departamentos Central y Paraguarí (República del Paraguay). Las descargas de origen agropecuario, urbano e industrial contaminan sus aguas. En este trabajo se evalúa la calidad del arroyo mediante sus características fisicoquímicas, ecotoxicológicas, microbiológicas y se la comparan con la legislación vigente. Se colectaron muestras en los meses de Julio y Setiembre del año 2014. Se estudiaron tres sitios denominados S1, ubicado en aguas arriba de la Ciudad de Carapegua; S2 en la intersección del arroyo con la Ruta 1, y S3, en la zona límite de las ciudades de Carapegua y Nueva Italia. Se realizaron ensayos de toxicidad aguda con Daphnia magna, Lactuca sativa, y alevines de Danio rerio; además de ensayos crónicos en Tetradesmus wisconsinenesis, D. rerio y Allium cepa. Se evaluaron los grupos y especies microbianos siguientes: aerobios mesófilos, enterobacterias, coliformes totales, coliformes fecales, E. coli, Pseudomona aeruginosa, mohos y levaduras; además se determinaron índices de calidad y de contaminación. Los resultados indican que las aguas del arroyo presentaron características de clase II y de clase III según el padrón establecido por la Secretaría del Ambiente del Paraguay. El índice de calidad de agua (ICA) arrojó valores comprendidos entre 52 y 62 lo que otorga la clasificación de "regular"; mientras que el índice de contaminación trófica (ICOTRO) presentó valores entre 0,12 y 0.26, indicando "eutrofización". Los recuentos de coliformes fueron superiores en el segundo muestreo, aunque dentro lo establecido por la norma. La presencia de P. aeruginosa en los tres puntos constituye un riesgo para la salud. Ensayos ecotoxicológicos agudos mostraron que las aguas presentan escasos efectos letales, no obstante los ensayos crónicos en A. cepa y el test de micronúcleos en D. rerio indican potenciales efectos citotóxicos y genotóxicos de las aguas del Arroyo Caañabe. ; The Caañabe stream is a watercourse that runs between the Departments Central and Paraguarí (Republic of Paraguay). Discharges of agricultural origin, urban and industrial pollute its waters. In this work the quality of the stream was assessed by its physicochemical characteristics, ecotoxicological, microbiological and compared with the current legislation. Samples were collected in July and September of 2014 from three study sites: S1, situated upstream from the city of Carapegua; S2, situated at the intersection of the stream and Route 1; and S3, situated at the border area between the cities of Carapegua and Nueva Italia. Assays were performed for acute toxicity in Daphnia magna, Lactuca sativa and fingerlings of Danio rerio, as well as assays for chronic toxicity in Tetradesmus wisconsinenesis, D. rerio and Allium cepa. The following microbial groups and species were determined: aerobic mesophilic bacteria, enterobacteria, total coliforms, fecal coliforms, E. coli, Pseudomona aeruginosa, molds and yeasts; and the quality and contamination indices were determined. The results indicate that the waters of the stream presented Class II and Class III features according to the standards set by the Secretariat of the Environment in Paraguay. The water quality index (ICA by its Spanish acronym) gave values between 52 and 62, which allows the classification of "regular"; while the trophic contamination index (ICOTRO by its Spanish acronym) presented values between 0.12 and 0.26, indicating "eutrophication". The coliform recount was higher in the second sampling, although within the limits established by the standards. The presence of P. aeruginosa at the three points represents a health risk. Ecotoxicological assays showed that the waters produced few lethal effects; however, the chronic assays in A. cepa and the micronucleus test in D. rerio indicate potential cytotoxic and genotoxic effects. ; O "Arroyo de Caañabe" é um riacho que atravessa os departamentos Central e Paraguari (Paraguai) e sofre contaminação proveniente do desague de restos de origem agropecuária, urbana e industrial. A qualidade de suas águas com base nas características físico-químicas, ecotoxicológicas, microbiológicas foi avaliada levando-se em consideração a legislação vigente. Foram coletadas amostras nos meses de julho e setembro de 2014 de três pontos ao redor da cidade de Carapeguá. Foram realizados ensaios de toxicidade aguda com Daphnia magna, Lactuca sativa e alevinos de Danio rerio, assim como ensaios crônicos com Tetradesmus wisconsinenesis, D. rerio y Allium cepa. Foram analisados os seguintes microrganismos: aeróbios mesófilos, enterobacterias, coliformes totais, coliformes termotolerantes, E. coli, Pseudomona aeruginosa, fungos leveduriformes e filamentosos; além da determinação dos índices de qualidade e de contaminação. Os resultados obtidos indicam que as águas apresentam características de classe II e classe III segundo o padrão estabelecido pela Secretaria do Ambiente do Paraguai. O índice de qualidade de água (ICA) ficou entre 52 e 62, classificado, portanto como "regular", enquanto o índice de contaminação trófica (ICOTRO) ficou entre 0,12 e 0,26, indicando eutrofização. A quantificação de coliformes foi superior na segunda coleta, porém ainda dentro da norma. A presença de P. aeruginosa nos três pontos de amostragem representa risco à saúde. Os ensaios ecotoxicológicos agudos demonstraram que as águas do riacho Caañabe apresentam efeitos letais escassos, entretanto, os ensaios crônicos com A. cepa e o teste de micronúcleos em D. rerio indicaram que essas águas apresentam potencialmente efeitos citotóxicos e genotóxicos.