Nanosieves Fabricated By Interference Lithography And Electroforming

Self-sustaining Nickel membranes with periodic and regular distribution of pores, in the scale of hundred of nanometers, were produced by interference lithography and electroplating. The process consists in the recording of submicrometric 2D periodic photoresist columns, on a metal-coated glass substrate, using the double exposure of an interference fringe pattern. As the photoresist is a good electrical isolator, when the sample is immersed in a Ni electroplating bath, the array of photoresist columns impedes the Nickel deposition in the patterned areas. A nickel film is then growth among the photoresist columns with a thickness up to 80 % of the height of the columns. In order to release the submicrometric membrane from the substrate, a thick hexagonal Nickel sustaining structure is electroformed, using conventional photolithography. The dimensions of the sustaining structure can be adapted in order to fulfill the pressure requirements of the filtration system. The good uniformity of the pore sizes as well as the smooth of the surface make such devices very interesting for separation of particles by size in filtration systems.6037Sard Ghayeni, S.B., Beatson, P.J., Fane, A.J., Schneider, R.P., Bacterial passage through microfiltration membranes in wastewater applications (1999) J. Membr. Sci., 153, pp. 71-82(2002) Life Science CatalogueCalvo, J.I., Hernandez, A., Pradanos, P., Martinez, L., Bowen, W.R., Pore size distribution in microporous membranes, II bulk characterization of track-etched filters by air porometry and mercury prosimetry (1995) Journal of Colloid and Interface Science, 176, pp. 467-478Han, K., Xu, W., Ruiz, A., Ruchhoeft, P., Chellam, S., Fabrication and characterization of polymeric microfiltration membranes using aperture array lithography (2005) J. Membr. Sci., 249, pp. 193-206Kuiper, S., Van Wolferen, H., Van Rijn, C., Nijdam, W., Krijnem, G., Elwenspoek, M., Fabrication of microsieves with sub-micron pore size by laser interference lithography (2001) Journal, of Micromehcanics and Microengineering, 11, pp. 33-37Van Rijn, C.J.M., Veldhuis, G.J., Kuiper, S., Nanosieves with microsystem tecnology for microfiltration applications (1998) Nanotechnology, 9, pp. 343-345Kuiper, S., Boer, M.D., Van Rijn, C., Nijdarh, W., Krijnen, G., Elwenspoek, M., Wet and dry etching techniques for the release of sub-micrometre perforated membranes (2000) Journal of Micromechanics and Microengineering, 10, pp. 171-174Gutierrez-Rivera, L.E., De Carvalho, E.J., Suva, M.A., Cescato, L., Metallic submicrometric sieves fabricated by interferometric litography and electroforming (2005) Journal of Micromechanics and Microengineering, 15, pp. 1932-1937Griffiths, S.K., Nilson, R.H., Hruby, J.M., (1996) Modeling Electrodeposition for LIGA Microdevice Fabrication, , http://www.ca.sandia.gov/liga/process_archives.html, Sandia National Laboratories, Livermore, CaliforniaFrejlich, J., Cescato, L., Mendes, G.F., Analysis of an active stabilization system for an holographic setup (1998) Appl. Opt., 27, pp. 1967-1976Zaidi, H.S., Brueck, S.R.J., Multiple-exposure interferometric lithography (1993) J. Vac. Sci. Technol. B, 11, pp. 658-666Mello, B.A., Costa, I.F., Lima, C.R.A., Cescato, L., Developed profile of holographically exposed photoresist gratings (1995) Applied Optics, 34, pp. 597-603Mack, C.A., Development of positive photoresists (1987) J. Electrochem. Soc., 134, pp. 148-152Spiro, P., (1971) Electroforming: A Comprehensive Survey of Theory, Practice and Commercial Applications2th Edition, , Robert Draper LTDKuiper, S., Van Rijn, C.J., Nijdam, W., Elwenspoek, M.C., Development and applications of very high flux microfiltration membranes (1998) Journal of Membrane Science, 150, pp. 1-8www.mediacy.co

Aspectos citológicos da diferenciação de tecidos de cafeeiro cultivado "in vitro"

Callus was established from leaves and shoots of Coffea arabica L. on nutrient medium with various levels of auxins and kinetin. Morphogenesis is controllable in such callus tissues by manipulation of the growth factor levels in the media. The study shows that callus culture obtained from leaves are in different states of differentiation, i.e., although the calluses were similar in appearence, their morphogenetical potential was different. The cells in culture show a great range of growth and form, and that form and behaviour of such cells do not correspond with recognized cell types in normal plant tissues or meristems. Proembryoids and vascularization (Fig. 1), giant cells (Fig. 4) and other patterns of cell differentiation (Figs. 2 and 3) were observed. The initiation of an organized system is probably dependent upon some rather specific environmental conditions. The extent to which certain specific types of differentiation are concomitant would seem to be a reflection of the extent to which common factors are involved. Thus, in this type of change, casuality of the nuclear change to the other changes would be unlikely.O cultivo de explantes de folha de cafeeiro enriquecidos com hormônios mostrou que a partir de tecidos diferenciados ocorre uma desdiferenciação. Essa desdiferenciação alcança diferentes níveis devido, provavelmente, a fatores ambientais, e não genéticos. Observou-se nos calos obtidos uma variação nos padrões de diferenciação celular. Pro-embrióides e vascularização (Fig. 1), células gigantes (Fig. 4) e outros padrões de diferenciação (Figs. 2 e 3) foram observados. As células em cultura diferenciaram-se sem perder as potencialidades genéticas iniciais do embrião, do qual derivaram; mudanças ambientais e nos mecanismos de regulação gênica são responsáveis pela variação fenotípica observada. Explantes de caules de café produziram calos que diferenciaram-se em raiz e em parte aérea (Fig. 6) chegando-se a obter uma diferenciação até 3 pares de folhas. Discutem-se neste trabalho, vários aspectos relacionados com morfogênese e interações gênico-ambientais

Identification of Linearized RMS-Voltage Dip Patterns Based on Clustering in Renewable Plants

[EN] Generation units connected to the grid are currently required to meet low-voltage ride-through (LVRT) requirements. In most developed countries, these requirements also apply to renewable sources, mainly wind power plants and photovoltaic installations connected to the grid. This study proposes an alternative characterisation solution to classify and visualise a large number of collected events in light of current limits and requirements. The authors' approach is based on linearised root-mean-square-(RMS)-voltage trajectories, taking into account LRVT requirements, and a clustering process to identify the most likely pattern trajectories. The proposed solution gives extensive information on an event's severity by providing a simple but complete visualisation of the linearised RMS-voltage patterns. In addition, these patterns are compared to current LVRT requirements to determine similarities or discrepancies. A large number of collected events can then be automatically classified and visualised for comparative purposes. Real disturbances collected from renewable sources in Spain are used to assess the proposed solution. Extensive results and discussions are also included in this study.The authors thank the financial support from the 'Ministerio de Economia y Competitividad' (Spain) and the European Union - ENE2016-78214-C2-2-R, Fulbright/Spanish Ministry of Education Visiting Scholar - PRX14/00694. This work was also supported by the US Department of Energy under contract no. DE-AC36-08-GO28308 with the National Renewable Energy LaboratoryGarcía-Sánchez, TM.; Gómez-Lázaro, E.; Muljadi, E.; Kessler, M.; Muñoz-Benavente, I.; Molina-García, A. (2018). Identification of Linearized RMS-Voltage Dip Patterns Based on Clustering in Renewable Plants. IET Generation Transmission & Distribution. 12(6):1256-1262. https://doi.org/10.1049/iet-gtd.2017.0474S12561262126Craciun B. Kerekes T. Sera D.et al.: ‘Overview of recent grid codes for PV power integration’.13th Int. Conf. on Optimization of Electrical and Electronic Equipment (OPTIM) 2012 May2012 pp.959–965‘World Energy Outlook 2012’. Technical Report International Egency Agency (IEA) 2012. Available atwww.iea.orgBehrens C.E.: ‘Energy policy: 113th congress issues’.Congressional Research Service 2013Lopes, J. A. P., Hatziargyriou, N., Mutale, J., Djapic, P., & Jenkins, N. (2007). Integrating distributed generation into electric power systems: A review of drivers, challenges and opportunities. Electric Power Systems Research, 77(9), 1189-1203. doi:10.1016/j.epsr.2006.08.016Glassmire, J., Komor, P., & Lilienthal, P. (2012). Electricity demand savings from distributed solar photovoltaics. Energy Policy, 51, 323-331. doi:10.1016/j.enpol.2012.08.022Carvalho, D., Wemans, J., Lima, J., & Malico, I. (2011). Photovoltaic energy mini-generation: Future perspectives for Portugal. Energy Policy, 39(9), 5465-5473. doi:10.1016/j.enpol.2011.05.016Battaglini, A., Komendantova, N., Brtnik, P., & Patt, A. (2012). Perception of barriers for expansion of electricity grids in the European Union. Energy Policy, 47, 254-259. doi:10.1016/j.enpol.2012.04.065‘European Commission 2010a. Energy 2020. A strategy for competitive sustainable and secure energy’. Technical Report Brussels November2011Beurskens P.V.L.W.M. Hekkenberg M.: ‘Renewable energy projections as published in the national renewable energy action plans of the european member states’. Technical Report European Environment Agency (EEA) November2011Coll-Mayor, D., Paget, M., & Lightner, E. (2007). Future intelligent power grids: Analysis of the vision in the European Union and the United States. Energy Policy, 35(4), 2453-2465. doi:10.1016/j.enpol.2006.09.001Passey, R., Spooner, T., MacGill, I., Watt, M., & Syngellakis, K. (2011). The potential impacts of grid-connected distributed generation and how to address them: A review of technical and non-technical factors. Energy Policy, 39(10), 6280-6290. doi:10.1016/j.enpol.2011.07.027Sangroniz N. Mora J.A. Teixeira M.D.: ‘Review of international grid codes for wind generation’ 2009‘Global Market Outlook for Photovoltaics Until 2016’. Technical Report European Photovoltaic Industry Association 2012. Available atwww.epia.orgKim S. Bollen M.: ‘Towards the development of a set of grid code requirements for wind farms: transient reactive power requirements’. Technical Report Available as Elforsk Report 13 : 04. Part 3 Report of Vindforsk Project V‐369 Vindforsk III January2013Tsili, M., & Papathanassiou, S. (2009). A review of grid code technical requirements for wind farms. IET Renewable Power Generation, 3(3), 308. doi:10.1049/iet-rpg.2008.0070Hossain, J., & Mahmud, A. (Eds.). (2014). Renewable Energy Integration. Green Energy and Technology. doi:10.1007/978-981-4585-27-9Sourkounis C. Tourou P.: ‘Grid code requirements for wind power integration in Europe’.Conf. Papers in Energy 2013 pp.1–9Voltage Ride-Through Capability Verification of Wind Turbines With Fully-Rated Converters Using Reachability Analysis. (2014). IEEE Transactions on Energy Conversion, 29(2), 392-405. doi:10.1109/tec.2013.2295168Mohseni, M., & Islam, S. M. (2012). Review of international grid codes for wind power integration: Diversity, technology and a case for global standard. Renewable and Sustainable Energy Reviews, 16(6), 3876-3890. doi:10.1016/j.rser.2012.03.039‘Royal Decree 1565/2010 by which regulates and modifies certain aspects of the activity of production of electric energy in special regime. (In spanish)’. Technical Report November2010Sourkounis C. Tourou P.: ‘Grid code requirements for wind power integration in Europe’.Conf. Papers in Science 2013Jiménez, F., Gómez-Lázaro, E., Fuentes, J. A., Molina-García, A., & Vigueras-Rodríguez, A. (2011). Validation of a double fed induction generator wind turbine model and wind farm verification following the Spanish grid code. Wind Energy, 15(4), 645-659. doi:10.1002/we.498Montoro D.: ‘Recommendations for unified technical regulations for grid‐connected PV systems’. Technical Report SUNRISE project – European Photovoltaic Industry Association the European Construction Industry Federation the European Association of Electrical Contractors International Union of Architects 2009. Available athttp://www.pvsunrise.eu/Merino, J., Mendoza-Araya, P., & Veganzones, C. (2014). State of the Art and Future Trends in Grid Codes Applicable to Isolated Electrical Systems. Energies, 7(12), 7936-7954. doi:10.3390/en7127936deAlmeida P. Barbosa P. Duque C.et al.: ‘Grid connection considerations for the integration of PV and wind sources’.IEEE 16th Int. Conf. on Harmonics and Quality of Power (ICHQP) May2014 pp.6–9‘Network code requirements for grid connection applicable to all generators’. Technical Report European Network of Transmission System Operators for Electricity ENTSO‐E October2013. Available athttps://www.entsoe.eu/Kagan N. Ferrari E. Matsuo N.et al.: ‘Influence of rms variation measurement protocols on electrical system performance indices for voltage sags and swells’.Proc. Ninth Int. Conf. on Harmonics and Quality of Power 2000 2000 vol.3 pp.790–795Bollen, M. H. J. (2003). Algorithms for characterizing measured three-phase unbalanced voltage dips. IEEE Transactions on Power Delivery, 18(3), 937-944. doi:10.1109/tpwrd.2003.813879Bollen M.H.: ‘Comparing voltage dip survey results’.Power Engineering Society Winter Meeting 2002 2002 vol.2 pp.1130–1134Moreno‐Muñoz A. de laRosa J.: ‘Voltage sag in highly automated factories’.Industry Applications Society Annual Meeting IAS'08 2008 pp.1–6Gomez-Lazaro, E., Fuentes, J. A., Molina-Garcia, A., & Canas-Carreton, M. (2009). Characterization and Visualization of Voltage Dips in Wind Power Installations. IEEE Transactions on Power Delivery, 24(4), 2071-2078. doi:10.1109/tpwrd.2009.2027513Gunther, E. W., & Mebta, H. (1995). A survey of distribution system power quality-preliminary results. IEEE Transactions on Power Delivery, 10(1), 322-329. doi:10.1109/61.368382Belloni F. Chiappa C. Chiumeo R.et al.: ‘Voltage dip measurements along MV lines vs primary substations measurements’.Int. Conf. on Renewable Energies and Power Quality (ICREPQ'12) March2012 pp.28–30Garcia-Sanchez, T., Gomez-Lazaro, E., Muljadi, E., Kessler, M., & Molina-Garcia, A. (2016). Statistical and Clustering Analysis for Disturbances: A Case Study of Voltage Dips in Wind Farms. IEEE Transactions on Power Delivery, 31(6), 2530-2537. doi:10.1109/tpwrd.2016.2522946Barrera Nunez V. Melendez Frigola J. Herraiz Jaramillo S.: ‘A survey on voltage sag events in power systems’.IEEE/PES Transmission and Distribution Conf. and Exposition: Latin America 2008 August2008 pp.1–3‘IEEE Standard 519‐1992: Recommended practices and requirements for harmonic control in electrical power systems’. Technical Report 1993. Available athttp://ieeexplore.ieee.org/servlet/opac?punumber=2227‘1159‐2009‐IEEE Recommended practice for monitoring electric power quality’. Technical Report June2009. Available athttp://ieeexplore.ieee.org/servlet/opac?punumber=515405

Feeding strategies and energy to protein ratio on tambaqui performance and physiology

The objective of this work was to evaluate the effect of feed deprivation and refeeding with diets containing different energy to protein ratios (E/P) on the performance and physiology of juvenile tambaqui (Colossoma macropomum). A 4x2 factorial arrangement with three replicates was used, with four E/P ratios (11.5, 10.5, 9.5, and 8.5 kcal g-1 digestible energy per protein) and two feeding regimens (with and without deprivation), during 60 days. Fish from the food-deprived group were fasted for 14 days and refed from the fifteenth to the sixtieth day, whereas the remaining fish were fed for 60 days. At the end of the experimental period, weight of fish subjected to food deprivation was lower than that of those continuously fed; however, this condition did not influence the physiological parameters analyzed. Tambaqui fed 11.5 kcal g-1 achieved lower final weight than those fed with the other diets, in both regimens. Among the physiological parameters, only plasma protein presented significant increase in fish fed 8.5 kcal g-1, in both feeding regimens, probably due to the higher dietary protein concentration. These results indicate that fish show a partial compensatory growth, and that 10.5 kcal g-1 can be recommended for the diet of juvenile tambaqui