• Energy Research
• nano-technology close
• 3. Good health close
• English close

{"references": ["T Gopinathan, K P Arul Shri: Simulation of Recharging Battery of the\nPacemaker using Piezoelectric Crystal from the Pulse in Aorta, Thesis,\nDec 2011.", "H.W. Ko: US Patent 3456134A: Piezoelectric Energy Converter for\nElectronic Implants, 1969.", "A. Badel: R\u00e9cup\u00e9ration d'Energie et Contr\u00f4le Vibratoire par El\u00e9ments\nPi\u00e9zo\u00e9lectriques Suivant une Approche Non Lin\u00e9aire, Ph.D. Thesis,\nUniversit\u00e9 de Savoie, 2008.", "M. Deterre: Toward an Energy Harvester for Leadless Pacemakers,\nPh.D. Thesis, Paris-Sud Univ. 2013.", "N. Andrew: Redington,CardiacDept, Brompton Hospital, Fulham Road,\nLondon SW3 6HP, in press.", "R. White, G. Savage, M. Zdeblick: US Patent 7729768 B2: Implantable\nCardiac Motion Powered Piezoelectric Energy Source.", "S. Priya, D.J. Inman: Energy Harvesting Technologies.", "N. Bassiri-Gharb : Piezoelectric Mems: Materials and Devices,\nPiezoelectric and Acoustic Materials for Transducer Applications, A.\nSafari, E.K. Akdogan, eds., Springer US, 2008, pp. 413\u2013430.", "W. Clark, C. Mo : Energy Harvesting Technologies, Ch.16, pp.405-430,\nS. Priya, D.J. Inman eds., Springer, 2009.\n[10] M. Deterre, E. Lefeuvre, E. Dufour-Gergam : An Active Piezoelectric\nEnergy Extraction Method for Pressure Energy Harvesting, Smart\nMaterials and Structures, Vol.21(8), 085004, 2012.\n[11] M.A. Karami, D.J. Inman: Powering Pacemakers from Heartbeat\nVibrations Using Linear and Nonlinear Energy Harvesters, Appl. Phys.\nLett. 100, 042901 (2012), in press.\n[12] S.R Anton, H.A Sodano : A Review of Power Harvesting Using\nPiezoelectric Materials (2003\u20132006), Smart Materials and Structures,\nVol.16(3), R1, 2007."]} Present project consists in a study and a development of piezoelectric devices for supplying power to new generation pacemakers. They are miniaturized leadless implants without battery placed directly in right ventricle. Amongst different acceptable energy sources in cardiac environment, we choose the solution of a device based on conversion of the energy produced by pressure variation inside the heart into electrical energy. The proposed energy harvesters can meet the power requirements of pacemakers, and can be a good solution to solve the problem of regular surgical operation. With further development, proposed device should provide enough energy to allow pacemakers autonomy, and could be good candidate for next pacemaker generation.

{"references": ["F. Guti\u00e9rrez-Mart\u00edn, J. Garc\u00eda-De Mar\u00eda, A. Ba\u00efri and N. Laraqi, \"Management strategies for surplus electricity loads using electrolytic hydrogen,\" International journal of hydrogen energy, vol 34, no 20, pp. 8468-8475, 2009.", "C. Mansilla, J. Louyrette, S. Albou, C. Bourasseau and S. Dautremont, \"Economic competitiveness of off-peak hydrogen production today\u2013A european comparison,\" Energy, vol 55, pp. 996-1001, 2013.", "D. Johansson, P. Franck and T. Berntsson, \"Hydrogen production from biomass gasification in the oil refining industry\u2013a system analysis,\" Energy, vol 38, no 1, pp. 212-227, 2012.", "M. Balat, \"Potential importance of hydrogen as a future solution to environmental and transportation problems,\" International journal of hydrogen energy, vol 33, no 15, pp. 4013-4029, 2008.", "S. Sharma and S. K. Ghoshal, \"Hydrogen the future transportation fuel: From production to applications,\" Renewable and sustainable energy reviews, vol 43, pp. 1151-1158, 3 2015.", "J. Alazemi and J. Andrews, \"Automotive hydrogen fuelling stations: An international review,\" Renewable and sustainable energy reviews, vol 48, pp. 483-499, 8 2015.", "Wood, H. He, T. Joia, M. Krivy and D. Steedman, \"Communication\u2014Electrolysis at high efficiency with remarkable hydrogen production rates,\" Journal of the electrochemical society, vol 163, no 5, pp. F327-F329, 2016.", "J. Ivy, \"Summary of electrolytic hydrogen production: Milestone completion report,\" 2004.", "P. Caumon, M. L. Zulueta, J. Louyrette, S. Albou, C. Bourasseau and C. Mansilla, \"Flexible hydrogen production implementation in the french power system: Expected impacts at the french and european levels,\" Energy, vol 81, pp. 556-562, 2015. \n[10]\tR. Loisel, \"Power system flexibility with electricity storage technologies: A technical\u2013economic assessment of a large-scale storage facility,\" International journal of electrical power & energy systems, vol 42, no 1, pp. 542-552, 2012. \n[11]\tDincer and C. Acar, \"Review and evaluation of hydrogen production methods for better sustainability,\" International journal of hydrogen energy, vol 40, no 34, pp. 11094-11111, 2015. \n[12]\tGonz\u00e1lez, E. McKeogh and B. Gallachoir, \"The role of hydrogen in high wind energy penetration electricity systems: The irish case,\" Renewable energy, vol 29, no 4, pp. 471-489, 2004. \n[13]\tE. Troncoso and M. Newborough, \"Electrolysers for mitigating wind curtailment and producing 'green' merchant hydrogen,\" International journal of hydrogen energy, vol 36, no 1, pp. 120-134, 1 2011. \n[14]\tC. J\u00f8rgensen and S. Ropenus, \"Production price of hydrogen from grid connected electrolysis in a power market with high wind penetration.\" International journal of hydrogen energy, vol 33, no 20, pp. 5335-5344, 10 2008. \n[15]\tG. Naterer, M. Fowler, J. Cotton and K. Gabriel, \"Synergistic roles of off-peak electrolysis and thermochemical production of hydrogen from nuclear energy in canada,\" International journal of hydrogen energy, vol 33, no 23, pp. 6849-6857, 2008. \n[16]\tJ.I. Levene, M.K. Mann, R. Margolis, and A. Milbrandt, \"Http://Www.nrel.gov/docs/fy05osti/37612.pdf,\" In Orlando, Florida, 2005.\n[17]\tW. Xiao, Y. Cheng, W. J. Lee, V. Chen and S. Charoensri, \"Hydrogen filling station design for fuel cell vehicles,\" Industry applications, IEEE transactions on, vol 47, no 1, pp. 245-251, 2011. \n[18]\tL. Zhao and J. Brouwer, \"Dynamic operation and feasibility study of a self-sustainable hydrogen fueling station using renewable energy sources,\" International journal of hydrogen energy, vol 40, no 10, pp. 3822-3837, 2015. \n[19]\tR. S. El-Emam, H. Ozcan and I. Dincer, \"Comparative cost evaluation of nuclear hydrogen production methods with the hydrogen economy evaluation program (HEEP),\" International journal of hydrogen energy, vol 40, no 34, pp. 11168-11177, 2015. \n[20]\tC. Acar and I. Dincer, \"Impact assessment and efficiency evaluation of hydrogen production methods,\" International journal of energy research, vol 39, no 13, pp. 1757-1768, 2015."]} The rapid growth of renewable energy sources and their integration into the grid have been motivated by the depletion of fossil fuels and environmental issues. Unfortunately, the grid is unable to cope with the predicted growth of renewable energy which would lead to its instability. To solve this problem, energy storage devices could be used. Electrolytic hydrogen production from an electrolyser is considered a promising option since it is a clean energy source (zero emissions). Choosing flexible operation of an electrolyser (producing hydrogen during the off-peak electricity period and stopping at other times) could bring about many benefits like reducing the cost of hydrogen and helping to balance the electric systems. This paper investigates the price of hydrogen during flexible operation compared with continuous operation, while serving the customer (hydrogen filling station) without interruption. The optimization algorithm is applied to investigate the hydrogen station in both cases (flexible and continuous operation). Three different scenarios are tested to see whether the off-peak electricity price could enhance the reduction of the hydrogen cost. These scenarios are: Standard tariff (1 tier system) during the day (assumed 12 p/kWh) while still satisfying the demand for hydrogen; using off-peak electricity at a lower price (assumed 5 p/kWh) and shutting down the electrolyser at other times; using lower price electricity at off-peak times and high price electricity at other times. This study looks at Derna city, which is located on the coast of the Mediterranean Sea (32° 46′ 0 N, 22° 38′ 0 E) with a high potential for wind resource. Hourly wind speed data which were collected over 24½ years from 1990 to 2014 were in addition to data on hourly radiation and hourly electricity demand collected over a one-year period, together with the petrol station data.

{"references": ["P. Peumans, S. Uchida, S.R. Forrest, Efficient bulk heterojunction photovoltaic cells using small-molecular-weight organic thin films, Nature 425 (2003) 158-162.", "R. Liu, Hybrid Organic/Inorganic Nanocomposites for Photovoltaic Cells, Materials 7 (2014) 2747-2771.s", "T. Lin, F. Huang, J. Liang, Y. Wang, A facile preparation route for boron-doped graphene, and its CdTe solar cell application, Energy & Environmental Science 4 (2011) 862-865.", "Y. Zhou, M. Eck, C. Men, F. Rauscher, P. Niyamakom, S. Yilmaz, I. Dumsch, S. Allard, U. Scherf, M. Kruger, Efficient polymer nanocrystal hybrid solar cells by improved nanocrystal composition, Solar Energy Materials & Solar Cells 95 (2011) 3227-3232.", "Z. Pan, H. Zhang, K. Cheng, Y. Hou, J. Hua, X. Zhong, Highly Efficient Inverted Type-I CdS/CdSe Core/Shell Structure QD-Sensitized Solar Cells, ACS Nano 6 (2012) 3982-3991.", "C. Gretener, J. Perrenoud, L. Kranz, L. Kneer, R. Schmitt, S. Buecheler, A.N. Tiwari, CdTe/CdS thin film solar cells grown in substrate configuration, Prog. Photovolt:Res. Appl. (2012) doi:10.1002/pip.2233.", "L.Y. Chang, R.R. Lunt, P.R. Brown, V. Bulovic, M.G. Bawendi, Low-Temperature Solution-Processed Solar Cells Based on PbS Colloidal Quantum Dot/CdS Heterojunctions, Nano Letters 13 (2013) 994-999.", "J.N. Freitas, A.S. Goncalves, A.F. Nogueira, A comprehensive review of the application of chalcogenide nanoparticles in polymer solar cells, Nanoscale 6 (2014) 6371-6397.", "L.H. Lai, L. Protesescu, M.V. Kovalenko, M.A. Loi, Sensitized solar cells with colloidal PbS\u2013CdS core\u2013shell quantum dots, Phys. Chem. Chem. Phys 16 (2014) 736-742.\n[10]\tR. Ahmed, L. Zhao, A.J. Mozer, G. Will, J. Bell, H. Wang, Enhanced Electron Lifetime of CdSe/CdS Quantum Dot (QD) Sensitized Solar Cells Using ZnSe Core\u2212Shell Structure with Efficient Regeneration of Quantum Dots, J. Phys. Chem. C 119 (2015) 2297-2307.\n[11]\tM.E. Mathew, J.C. Mohan, K. Manzoor, S.V. Nair H. Tamura, R. Jayakumar, Folate conjugated carboxymethyl chitosan\u2013manganese doped zinc sulphide nanoparticles for targeted drug delivery and imaging of cancer cells, Carbohydrate Polymers 80 (2010) 442\u2013448.\n[12]\tF.Y. Shen, W. Que, X.T. Yin, Y.W. Huang, Q.Y. Jia, A facile method to synthesize high quality ZnS(Se) quantum dots for photoluminescence, Journal of Alloys and Compounds 509 (2011) 9105-9110.\n[13]\tX. Wang, H. Hu, S. Chen, K. Zhang, J. Zhang, W. Zou, R. Wang, One-step fabrication of BiOCl/CuS heterojunction photocatalysts with enhanced visible-light responsive activity, Materials Chemistry and Physics (2015) 1-7.\n[14]\tN.S.N. Jothi, A.G. Joshi, R.J. Vijay, A. Muthuvinayagam, P. Sagayaraj, Investigation on one-pot hydrothermal synthesis, structural and optical properties of ZnS quantum dots, Materials Chemistry and Physics 138 (2013) 186-191.\n[15]\tS. Chaguetmi, F. Mammeri, S. Nowak, P. Decorse, H. Lecoq, M. Gaceur, J.B. Naceur, S. Achour, R. Chtourou, S. Ammar, Photocatalytic activity of TiO2 nanofibers sensitized with ZnS quantum dots, RSC Advances 3 (2013) 2572-2580.\n[16]\tT. Zhao, X. Hou, Y.N. Xie, L. Wu, P. Wu, Phosphorescent sensing of Cr3+ with proteinfunctionalized Mn-doped ZnS quantum dots, Analyst 138 (2013) 6589-6594.\n[17]\tD.I. Son, H.H. Kim, D.K. Hwang, S. Kwon, W.K. Choi, Inverted CdSe\u2013ZnS quantum dots light-emitting diode using low-work function organic material polyethylenimine ethoxylated, J. Mater. Chem. C 2 (2014) 510-514.\n[18]\tC. Ippen, T. Greco, Y. Kim, J. Kim, M.S. Oh, C.J. Han, A. Wedel, ZnSe/ZnS quantum dots as emitting material in blue QD-LEDs with narrow emission peak and wavelength tenability, Organic Electronics 15 (2014) 126-131.\n[19]\tM. Mehrabian, K. Mirabbaszadeh, H. Afarideh, Solid-state ZnS quantum dot-sensitized solar cell fabricated by the Dip-SILAR technique, Phys. Scr 89 (2014) 1-8.\n[20]\tH.S. Mansur, A.A.P Mansur, A. Soriano-Ara\u00fajo, Z.I.P. Lobato, Beyond Biocompatibility: A Novel Approach for the Synthesis of ZnS Quantum Dot-Chitosan Nano-Immunoconjugates for Cancer Diagnosis, Green Chemistry (2015) doi:10.1039/C4GC02072C.\n[21]\tM.R. Kumar, N. Ramamurthy, P. Ambalavanan, Synthesis, structure and optical characterization of zns nanoparticles, International Journal of Current Physical Sciences 1 (2011) 6-9.\n[22]\tJ. Kim, C. Park, S.M. Pawar, A.I. Inamdar, Y. Jo, J.Han, J.P. Hong, Y.S. Parkc, D.-Y. Kim, W. Jung, H. Kim, H. Im, Optimization of sputtered ZnS buffer for Cu2ZnSnS4 thin film solar cells, Thin Solid Films 566 (2014) 88\u201392.\n[23]\tH. Chang and Hongkai Wu, Graphene-based nanocomposites: preparation, functionalization, and energy and environmental applications, Energy Environ. Sci., 6 (2013) 3483\u20133507.\n[24]\tY. Yu, Y. Yang, H. Gu, D. Yub, G. Shi, Size-controllable preparation of palladium nanoparticles assembled on TiO2/graphene nanosheets and their electrocatalytic activity for glucose biosensing, Anal. Methods 5 (2013) 7049-7057.\n[25]\tC. Hu , T. Lu , F. Chen, R. Zhang, A brief review of graphene\u2013metal oxide composites synthesis and applications in photocatalysis, Journal of the Chinese Advanced Materials Society 1 (1) (2013) 21-39.\n[26]\tY. Lei, R. Li, F. Chen, J. Xu, Hydrothermal synthesis of graphene\u2013CdS composites with improved photoelectric characteristics, J Mater Sci: Mater Electron 25 (2014) 3057-3061.\n[27]\tL. Jiang, M. Yao, B. Liu, Q. Li, R. Liu, H. Lv, S. Lu, C. Gong, B. Zou, T. Cui, B. Liu, Controlled Synthesis of CeO2/Graphene Nanocomposites with Highly Enhanced Optical and Catalytic Properties, J. Phys. Chem. C 116 (2012) 11741-11745.\n[28]\tX. Li, X. Wang, L. Zhang, S. Lee, H. Dai, Chemically Derived, Ultrasmooth Graphene Nanoribbon SemiconductorsScience 319 (2008) 1229-1232.\n[29]\tS.K. Kim, D. Yoon, S.-C. Lee, J. Kim, Mo2C/Graphene Nanocomposite As a Hydrodeoxygenation Catalyst for the Production of Diesel Range Hydrocarbons, ACS Catalysis 5 (6) (2015) 3292\u20133303,doi:10.1021/acscatal.5b00335.\n[30]\tD. Chen, W. Chen, L. Ma, G. Ji, K. Chang, J.Y. Lee, Graphene-like layered metal dichalcogenide/graphene composites: synthesis and applications in energy storage and conversion, Materials Today 17 (4) (2014) 184-193.\n[31]\tJaidev, S. Ramaprabhu, Poly(p-phenylenediamine)/graphene nanocomposites for supercapacitor applications, J. Mater. Chem. 22 (2012) 18775\u201318783.\n[32]\tM. Sookhakian, Y. M. Amin, S. Baradaran , M. T. Tajabadi, A. M. Golsheikh, W. J. Basirun, A layer-by-layer assembled graphene/zinc sulfide/polypyrrole thin-film electrode via electrophoretic deposition for solar cells, Thin Solid Films 552 (2014) 204\u2013211.\n[33]\tL. Scudiero, Y. Shen, M.C. Gupta, Effect of light illumination and temperature on P3HT films, n-type Si,and ITO, Applied Surface Science 292 (2014) 100-106. \n[34]\tP. Ramidi, O. Abdulrazzaq, C.M. Felton, Y. Gartia, V. Saini, A.S. Biris, A. Ghosh, Triplet Sensitizer Modification of Poly(3-hexyl)thiophene (P3HT) for Increased Efficiency in Bulk Heterojunction Photovoltaic Devices, Energy Technol.2 (2014) 604-611.\n[35]\tM.J.M. Wirix, P.H.H. Bomans, H. Friedrich, N.A.J.M. Sommerdijk, G.de With, Three-Dimensional Structure of P3HT Assemblies in Organic Solvents Revealed by Cryo-TEM, Nano Lett. 14 (2014) 2033\u22122038.\n[36]\tW.-F. Fu, Y. Shi, L. Wang, M.-M. Shi, H.-Y. Li, H.-Z. Chen, A green, low-cost, and highly effective strategy to enhance the performance of hybrid solar cells: Post-deposition ligand exchange by acetic acid, Solar Energy Materials & Solar Cells 117 (2013) 329-335.\n[37]\tS.-H. Choi, H. Song, I.K. Park, J.-H. Yum, S.-S. Kim, S. Lee, Y.-E. Sung, Synthesis of size-controlled CdSe quantum dots and characterization of CdSe\u2013conjugated polymer blends for hybrid solar cells, Journal of Photochemistry and Photobiology A: Chemistry 179 (2006) 135-141.\n[38]\tC.Y. Kwong, W.C.H. Choy, A.B. Djurisic, P.C. Chui, K.W. Cheng, W.K. Chan, Poly(3-hexylthiophene):TiO2 nanocomposites for solar cell applications, Nanotechnology 15 (2004) 1156-1161.\n[39]\tJ. Wu, G. Yue, Y. Xiao, J. Lin, M. Huang, Z. Lan, Q. Tang, Y. Huang, L. Fan, S. Yin, T. Sato, An ultraviolet responsive hybrid solar cell based on titania/poly(3-hexylthiophene), Scientific Reports 3:1283 (2013)1-6.\n[40]\tY. Firdaus, E. Vandenplas, Y. Justo, R. Gehlhaar, D. Cheyns, Z. Hens, M. V. Auweraer, Enhancement of the photovoltaic performance in P3HT: PbS hybrid solar cells using small size PbS quantum dots, Journal of Applied Physics, 116 (2014) 094305.\n[41]\tS.A. Mauger, L. Chang, C.W. Rochester, A.J. Moule, Directional dependence of electron blocking in PEDOT:PSS, Organic Electronics 13 (2012) 2747\u20132756.\n[42]\tS.B. Dkhil, R. Ebdelli, W. Dachraoui, H. Faltakh, R. Bourguiga, J. Davenas, Improved photovoltaic performance of hybrid solar cells based on silicon nanowire and P3HT, Synthetic Metals 192 (2014) 74-81.\n[43]\tS.D. Oosterhout, M.M. Wienk, S.S. van Bavel, R. Thiedmann, L.J.A. Koster, J. Gilot, J. Loos, V. Schmidt, R.A.J. Janssen, The effect of three-dimensional morphology on the efficiency of hybrid polymer solar cells, Nature Materials 8 (2009) 818-824.\n[44]\tE.K. Goharshadi, S.H. Sajjadi, R. Mehrkhah, P. Nancarrow, Sonochemical synthesis and measurement of optical properties of zinc sulfide quantum dots, Chemical Engineering Journal 209 (2012) 113-117.\n[45]\tZ. Tang, H. Wu, J. R. Cort, G. W. Buchko, Y. Zhang, Y. Shao, I. A. Aksay, J. Liu, Y. Lin, Constraint of DNA on Functionalized Graphene Improves its Biostability and Specificity, Small, 6(11) (2010) 1205\u20131209.\n[46]\tS.-D. Jiang, G. Tang, Y.-F. Ma, Y. Hu, L. Song, Synthesis of nitrogen-doped graphene-ZnS quantum dots composites with highly efficient visible light photodegradation, Materials Chemistry and Physics (2014) 1-9.\n[47]\tZ. Jindal, N.K. Verma, Photoluminescent properties of ZnS:Mn nanoparticles with in-built surfactant, J. Mater. Sci. 43 (2008) 6539-6545.\n[48]\tM.R. Karim, Synthesis and Characterizations of Poly(3-hexylthiophene) and Modified Carbon Nanotube Composites, Journal of Nanomaterials (2012) doi:10.1155/2012/174353.\n[49]\tG.A.H. Wetzelaer, P.W.M Blom, Diffusion-driven currents in organic-semiconductor diodes, NPG Asia Materials (2014) doi:10.1038/am.2014.41.\n[50]\tO. Breitenstein, P. Altermatt, K. Ramspeck, M.A. Green, Jianhua Zhao, A. Schenk, Interpretation of the Commonly Observed I-V Characteristics of C-Si Cells Having Ideality factor Larger Than Two IEEE Xplore (2006) doi: 10.1109/WCPEC.2006.279597."]} Zinc sulphide (ZnS) quantum dots (QDs) were synthesized successfully via simple sonochemical method. X-ray diffraction (XRD), scanning electron microscopy (SEM) and high resolution transmission electron microscopy (HRTEM) analysis revealed the average size of QDs of the order of 3.7 nm. The band gap of the QDs was tuned to 5.2 eV by optimizing the synthesis parameters. UV-Vis absorption spectra of ZnS QD confirm the quantum confinement effect. Fourier transform infrared (FTIR) analysis confirmed the formation of single phase ZnS QDs. To fabricate the diode, blend of ZnS QDs and P3HT was prepared and the heterojunction of PEDOT:PSS and the blend was formed by spin coating on indium tin oxide (ITO) coated glass substrate. The diode behaviour of the heterojunction was analysed, wherein the ideality factor was found to be 2.53 with turn on voltage 0.75 V and the barrier height was found to be 1.429 eV. ZnS-Graphene QDs nanocomposite was characterised for the surface morphological study. It was found that the synthesized ZnS QDs appear as quasi spherical particles on the graphene sheets. The average particle size of ZnS-graphene nanocomposite QDs was found to be 8.4 nm. From voltage-current characteristics of ZnS-graphene nanocomposites, it is observed that the conductivity of the composite increases by 104 times the conductivity of ZnS QDs. Thus the addition of graphene QDs in ZnS QDs enhances the mobility of the charge carriers in the composite material. Thus, the graphene QDs, with high specific area for a large interface, high mobility and tunable band gap, show a great potential as an electron-acceptors in photovoltaic devices.

Embora não seja tecnologia recente, as células a combustível ou Fuel Cells (FC) continuam recebendo grande atenção, pois são consideradas como "fontes de energia do futuro" devido a características como alto rendimento energético e baixa emissão de poluentes, permitindo a extensão o tempo de vida das reservas fósseis e contribuindo para a melhoria da qualidade de vida. Atualmente, as pesquisas estão direcionadas, principalmente, ao desenvolvimento de FC para aplicações em sistemas móveis e portáteis. De todas as tecnologias existentes, a mais promissora para essa finalidade é a célula a combustível de eletrólito polimérico, conhecida como PEMFC (Polymer Electrolyte Fuel Cell) cuja pesquisa encontra-se focada, principalmente, no desenvolvimento de membranas poliméricas, com o objetivo de reduzir os custos de produção. Este trabalho será focado nos aspectos físico-químicos do desenvolvimento de membranas poliméricas. Serão discutidos aspectos estruturais do Nafion® relacionado-os as seguintes propriedades físico-químicas: fluxo eletrosmótico, permeabilidade gasosa, transporte de água através da membrana, estabilidade química e térmica. Toda a discussão será realizada para polímeros perfluorados, utilizando o Nafion® como modelo representante dessa classe de polímeros.Fuel Cells (FC) continue to receive growing attention, in spite of not being a new technology, for they are considered as the "energy source of the future" owing to characteristics such as high energetic yield and low emission of pollutants. FC technology may lead to a reduction in the negative impact from energy sources on the enviroment, thus improving the quality of life and extending the lifetime of fossil combustible reserves. The mainstream of research in FC is now directed at mobile, portable systems, for which the most promising technology is the Polymer Electrolyte Fuel Cells, also known as PEMFC (Polymer Electrolyte Fuel Cell). Research in this topic focuses on the development of polymer membranes whose target is to reduce its production costs. In this work we shall focus on physicochemical aspects related to development of polymeric membranes. A discussion on structural aspects of Nafion® will be carried, which will be related to the following physicochemical properties: electrosmotic flux, gaseous permeability, water transport through polimeric membrane, chemical and thermal stabilities. All the discussion was made using Nafion® as model of perfluorated polymers.

We elucidate few critical facts about the lithium superionic conductor (Li10GeP2S12) and few other compounds of the same family as the electrolyte in Li-ion cells. The dimensionality of diffusion process and existence of ‘structural’ lithiums are not well understood in this material. From the ab-initio MD simulations, we find that the material transport Li-ions predominantly in the crystallographic c-direction. Nevertheless, the cross-channel diffusion is significant as well. We explored the mobility of individual Li-ions and do not find evidence that supports the proposition of structural Li-ions in LGPS. We find nominal effect of local Ge-P ordering and of Li-concentration change on diffusivity, which not only provides information about the invariance of diffusivity at different conditions of operation, but also ensures that identification of the ground state structure in LGPS having partially occupied Li and Ge/P sublattices should have minimal effect on the diffusion analysis. We computed the dilute Li insertion and extraction voltages for LGPS from ab-initio total energy calculation. The dilute voltages indicate that the material is prone to react by exchanging Li-ions with the electrodes at typical operating range of voltages indicating formation of some interphase at the electrode-electrolyte interface, which necessitates further experimental investigation

This report explores the effects of COVID-19 on household energy usage. Some of these effects are associated with the changes that happened after the COVID-19. The study also presents the different trends in the different households and what changed in the energy usage and if something is going wrong. The report will discuss the results and whether the energy usage decreased or increased or remained the same after COVID-19. The trials are from 35 households. It is collected from different cities in the United States and for different family sizes.The results of this study show the impacts of the COVID-19 in three different trends. The three different trends will be explained in detail and compared to before the pandemic.

So solid storage: The use of organic redox-active materials is a new tendency for rechargeable batteries, either as traditional solid-state electrode materials in lithium-ion batteries or as dissolved redox fluidic species in liquid electrolytes for redox flow batteries. The performance-limiting scenarios and some illuminating improvements by formulating electrolytes are reviewed. Electrolyte chemistry is critical for any energy-storage device. Low-cost and sustainable rechargeable batteries based on organic redox-active materials are of great interest to tackle resource and performance limitations of current batteries with metal-based active materials. Organic active materials can be used not only as solid electrodes in the classic lithium-ion battery (LIB) setup, but also as redox fluids in redox-flow batteries (RFBs). Accordingly, they have suitability for mobile and stationary applications, respectively. Herein, different types of electrolytes, recent advances for designing better performing electrolytes, and remaining scientific challenges are discussed and summarized. Due to different configurations and requirements between LIBs and RFBs, the similarities and differences for choosing suitable electrolytes are discussed. Both general and specific strategies for promoting the utilization of organic active materials are covered.