Geospatial analysis of the energy yield and environmental footprint of different photovoltaic module technologies

The majority of currently installed photovoltaic (PV) systems are based on mono- and polycrystalline silicon PV modules. Manufacturers of competing technologies often argue that due to the characteristics of their PV technologies, PV systems based on their modules are able to achieve higher annual energy yield, due to a smaller effect of temperature on module performance and/or a better performance at low light intensities. While these benefits have been confirmed in local studies many times, there is still limited insight as to the locations at which a particular technology actually performs best. In this study we have analysed the performance of a large set of PV modules, based on irradiance time series that were taken from satellite measurements. Using these data, and combining it with a PV performance model, we have made a geospatial analysis of the energy yield of different types of PV modules. We aim to make the energy yield of the investigated modules spatially explicit, allowing PV system installers to choose the best module type for every location investigated. Our results show that there is large geographical variety in the performance of PV modules, in terms of energy yield but also in terms of relative performance or performance ratio. While some technologies clearly exhibit a decrease in performance ratio at locations where they operate at higher temperatures, for some technologies this effect is much smaller. As a result of the variation in performance, the environmental footprint of.13V modules also shows large geographical variations. However, even at low irradiance locations the environmental footprint of PV modules in general is much lower compared to that of fossil fuel based electricity generation. (C) 2017 Elsevier Ltd. All rights reserved

Post-extraction mesio-distal gap reduction assessment by confocal laser scanning microscopy - a clinical 3-month follow-up study

[EN] AimThe aim of this 3-month follow-up study is to quantify the reduction in the mesio-distal gap dimension (MDGD) that occurs after tooth extraction through image analysis of three-dimensional images obtained with the confocal laser scanning microscopy (CLSM) technique. Materials and MethodsFollowing tooth extraction, impressions of 79 patients 1month and 72 patients 3months after tooth extraction were obtained. Cast models were processed by CLSM, and MDGD changes between time points were measured. ResultsThe mean mesio-distal gap reduction 1month after tooth extraction was 343.4m and 3months after tooth extraction was 672.3m. The daily mean gap reduction rate during the first term (between baseline and 1month post-extraction measurements) was 10.3m/day and during the second term (between 1 and 3months) was 5.4m/day. ConclusionsThe mesio-distal gap reduction is higher during the first month following the extraction and continues in time, but to a lesser extent. When the inter-dental contacts were absent, the mesio-distal gap reduction is lower. When a molar tooth is extracted or the distal tooth to the edentulous space does not occlude with an antagonist, the mesio-distal gap reduction is larger. The consideration of mesio-distal gap dimension changes can help improve dental treatment planning.The authors would like to express their gratitude to MEC (contract grant number AP2008-01653), to FEDER, to the Generalitat Valenciana for its help in the CLSM acquisition (MY08/ISIRM/S/100), to the Universitat Politecnica de Valencia (PAID-05-12) and to Dr. Asuncion Jaime for her translation assistance.García-Herraiz, A.; Silvestre, FJ.; Leiva García, R.; Crespo Abril, F.; Garcia-Anton, J. (2017). Post-extraction mesio-distal gap reduction assessment by confocal laser scanning microscopy - a clinical 3-month follow-up study. Journal Of Clinical Periodontology. 44(5):548-555. https://doi.org/10.1111/jcpe.12706S548555445Aguilar, M. L., Elias, A., Vizcarrondo, C. E. T., & Psoter, W. J. (2010). Analysis of three-dimensional distortion of two impression materials in the transfer of dental implants. The Journal of Prosthetic Dentistry, 103(4), 202-209. doi:10.1016/s0022-3913(10)60032-7Amit, G., JPS, K., Pankaj, B., Suchinder, S., & Parul, B. (2012). Periodontally accelerated osteogenic orthodontics (PAOO) - a review. Journal of Clinical and Experimental Dentistry, e292-296. doi:10.4317/jced.50822Armitage, G. C. (1999). Development of a Classification System for Periodontal Diseases and Conditions. Annals of Periodontology, 4(1), 1-6. doi:10.1902/annals.1999.4.1.1Belli, R., Pelka, M., Petschelt, A., & Lohbauer, U. (2009). In vitro wear gap formation of self-adhesive resin cements: A CLSM evaluation. Journal of Dentistry, 37(12), 984-993. doi:10.1016/j.jdent.2009.08.006Belli, R., Rahiotis, C., Schubert, E. W., Baratieri, L. N., Petschelt, A., & Lohbauer, U. (2011). Wear and morphology of infiltrated white spot lesions. Journal of Dentistry, 39(5), 376-385. doi:10.1016/j.jdent.2011.02.009Brauchli, L. M., Baumgartner, E.-M., Ball, J., & Wichelhaus, A. (2011). Roughness of enamel surfaces after different bonding and debonding procedures. Journal of Orofacial Orthopedics / Fortschritte der Kieferorthopädie, 72(1), 61-67. doi:10.1007/s00056-010-0002-3Chen, S. Y., Liang, W. M., & Chen, F. N. (2004). Factors affecting the accuracy of elastometric impression materials. Journal of Dentistry, 32(8), 603-609. doi:10.1016/j.jdent.2004.04.002Christou, P., & Kiliaridis, S. (2007). Three-dimensional changes in the position of unopposed molars in adults. The European Journal of Orthodontics, 29(6), 543-549. doi:10.1093/ejo/cjm036Craddock, H. L., Youngson, C. C., Manogue, M., & Blance, A. (2007). Occlusal Changes Following Posterior Tooth Loss in Adults. Part 2. Clinical Parameters Associated with Movement of Teeth Adjacent to the Site of Posterior Tooth Loss. Journal of Prosthodontics, 16(6), 495-501. doi:10.1111/j.1532-849x.2007.00223.xFaria, A. C. L., Rodrigues, R. C. S., Macedo, A. P., Mattos, M. da G. C. de, & Ribeiro, R. F. (2008). Accuracy of stone casts obtained by different impression materials. Brazilian Oral Research, 22(4), 293-298. doi:10.1590/s1806-83242008000400002García-Herraiz, A., Leiva-García, R., Cañigral-Ortiz, A., Silvestre, F. J., & García-Antón, J. (2011). Confocal laser scanning microscopy for the study of the morphological changes of the postextraction sites. Microscopy Research and Technique, 75(4), 513-519. doi:10.1002/jemt.21085Gragg, K. L., Shugars, D. A., Bader, J. D., Elter, J. R., & White, B. A. (2001). Movement of Teeth Adjacent to Posterior Bounded Edentulous Spaces. Journal of Dental Research, 80(11), 2021-2024. doi:10.1177/00220345010800111401LINDSKOG-STOKLAND, B., HANSEN, K., TOMASI, C., HAKEBERG, M., & WENNSTRÖM, J. L. (2011). Changes in molar position associated with missing opposed and/or adjacent tooth: a 12-year study in women. Journal of Oral Rehabilitation, 39(2), 136-143. doi:10.1111/j.1365-2842.2011.02252.xLove, W. D., & Adams, R. L. (1971). Tooth movement into edentulous areas. The Journal of Prosthetic Dentistry, 25(3), 271-278. doi:10.1016/0022-3913(71)90188-0Nishikawa, T., Masuno, K., Mori, M., Tajime, Y., Kakudo, K., & Tanaka, A. (2006). Calcification at the Interface Between Titanium Implants and Bone: Observation With Confocal Laser Scanning Microscopy. Journal of Oral Implantology, 32(5), 211-217. doi:10.1563/799.1Pereira, J. R., Murata, K. Y., Valle, A. L. do, Ghizoni, J. S., & Shiratori, F. K. (2010). Linear dimensional changes in plaster die models using different elastomeric materials. Brazilian Oral Research, 24(3), 336-341. doi:10.1590/s1806-83242010000300013Schilling, T., Müller, M., Minne, H. W., & Ziegler, R. (1998). Influence of Inflammation-Mediated Osteopenia on the Regional Acceleratory Phenomenon and the Systemic Acceleratory Phenomenon During Healing of a Bone Defect in the Rat. Calcified Tissue International, 63(2), 160-166. doi:10.1007/s002239900508Scivetti, M., Pilolli, G. P., Corsalini, M., Lucchese, A., & Favia, G. (2007). Confocal laser scanning microscopy of human cementocytes: Analysis of three-dimensional image reconstruction. Annals of Anatomy - Anatomischer Anzeiger, 189(2), 169-174. doi:10.1016/j.aanat.2006.09.009SHUGARS, D. A., BADER, J. D., PHILLIPS, S. W., WHITE, B. A., & BRANTLEY, C. F. (2000). THE CONSEQUENCES OF NOT REPLACING A MISSING POSTERIOR TOOTH. The Journal of the American Dental Association, 131(9), 1317-1323. doi:10.14219/jada.archive.2000.0385Thalmair, T., Fickl, S., Schneider, D., Hinze, M., & Wachtel, H. (2013). Dimensional alterations of extraction sites after different alveolar ridge preservation techniques - a volumetric study. 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Can we continue research in splenectomized dogs? Mycoplasma haemocanis: Old problem - New insight

We report the appearance of a Mycoplasma haemocanis infection in laboratory dogs, which has been reported previously, yet, never before in Europe. Outbreak of the disease was triggered by a splenectomy intended to prepare the dogs for a hemorrhagic shock study. The clinical course of the dogs was dramatic including anorexia and hemolytic anemia. Treatment included allogeneic transfusion, prednisone, and oxytetracycline. Systematic follow-up (n=12, blood smears, antibody testing and specific polymerase chain reaction) gives clear evidence that persistent eradication of M. haemocanis is unlikely. We, therefore, had to abandon the intended shock study. In the absence of effective surveillance and screening for M. haemocanis, the question arises whether it is prudent to continue shock research in splenectomized dogs. Copyright (C) 2004 S. Karger AG, Basel

Scanning X-ray nanodiffraction: from the experimental approach towards spatially resolved scattering simulations

An enhancement on the method of X-ray diffraction simulations for applications using nanofocused hard X-ray beams is presented. We combine finite element method, kinematical scattering calculations, and a spot profile of the X-ray beam to simulate the diffraction of definite parts of semiconductor nanostructures. The spot profile could be acquired experimentally by X-ray ptychography. Simulation results are discussed and compared with corresponding X-ray nanodiffraction experiments on single SiGe dots and dot molecules

Re-assessment of net energy production and greenhouse gas emissions avoidance after 40 years of photovoltaics development

Since the 1970s, installed solar photovoltaic capacity has grown tremendously to 230 gigawatt worldwide in 2015, with a growth rate between 1975 and 2015 of 45%. This rapid growth has led to concerns regarding the energy consumption and greenhouse gas emissions of photovoltaics production. We present a review of 40 years of photovoltaics development, analysing the development of energy demand and greenhouse gas emissions associated with photovoltaics production. Here we show strong downward trends of environmental impact of photovoltaics production, following the experience curve law. For every doubling of installed photovoltaic capacity, energy use decreases by 13 and 12% and greenhouse gas footprints by 17 and 24%, for poly-and monocrystalline based photovoltaic systems, respectively. As a result, we show a break-even between the cumulative disadvantages and benefits of photovoltaics, for both energy use and greenhouse gas emissions, occurs between 1997 and 2018, depending on photovoltaic performance and model uncertainties