Room-Temperature Cubic Phase Crystallization and High Stability of Vacuum-Deposited Methylammonium Lead Triiodide Thin Films for High-Efficiency Solar Cells

Methylammonium lead triiodide (MAPI) has emerged as a high-performance photovoltaic material. Common understanding is that at room temperature it adopts a tetragonal phase and it only converts to the perfect cubic phase around 50-60 ºC. Most MAPI films are prepared using a solution-based coating process, yet they can also be obtained by vapor phase deposition methods. Vapor phase processed MAPI films have significantly different characteristics compared to their solvent processed analogous, such as a relatively small crystal grain sizes and short excited state lifetimes. Yet solar cells based on vapor phase processed MAPI films exhibit high power conversion efficiencies. Surprisingly, after detailed characterization we find that our vapor phase processed MAPI films adopt a cubic crystal structure at room temperature that is stable for weeks, even in ambient atmosphere. Furthermore, we demonstrate that by tuning the deposition rates of both precursors during co-deposition it is possible to vary the perovskite phase from cubic to tetragonal at room temperature. Our finding challenges the common belief that MAPI is only stable in tetragonal phase at room temperature. Additionally, these findings can be used to explain the somewhat unexpected high performance of solar cells based on vacuum processed MAPI films with sub 100 nm grain sizes and excited state lifetimes < 100 nanoseconds

Four in One: Cryptic Diversity in Geoffroy’s Side-Necked Turtle \u3cem\u3ePhrynops geoffroanus\u3c/em\u3e (Schweigger 1812) (Testudines: Pleurodira: Chelidae) in Brazil

Turtles are one of the most threatened groups of vertebrates, with about 60% of species classified at some level of extinction risk. Compounding this extinction crisis are cryptic species and species complexes that are evaluated under a single species epithet but harbor multiple species, each of which needs to be evaluated independently. The Phrynops geoffroanus species group is a classic example. Described first in 1812, it is currently thought to harbor multiple species. To test this hypothesis, we collected mitochondrial and nuclear genomic data, morphometric data, and distribution and associated biome information. We applied statistically rigorous species delimitation analyses, taxonomic hypotheses tests, and fully coalescent phylogenetic reconstruction methods, concluding that the Phrynops geoffroanus species complex comprises four geographically structured species/lineages that diverged during the Pleistocene and are currently geographically structured along the main South American river basins and biomes. These species/lineages show subtle and largely non-significant differences in shape but are characterized by differences in coloration and patterns of marks on the head and plastron. Our results contribute to the understanding of species diversity and diversification of biodiversity in South America and provide an important basis for the conservation of freshwater turtles

Agregação e estabilidade de agregados de um neossolo quartzarênico sob sistemas agropecuários na Região do Bolsão-sul-mato-grossense.

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Inquete sorologica do Maedi-Visna em rebanho de ovelhas Rabo Largo no Norte do Ceará.

Resumo: Maedi-Visna (MV) é uma doença de ovinos, causada por lentivírus, responsável por uma infecção de caráter progressivo, lento e persistente. As perdas econômicas são falhas reprodutivas, morte, diminuição da produção láctea e perda de peso dos animais. A enfermidade foi introduzida no Brasil por meio da importação de raças exóticas infectadas. Baseando-se na elevação do risco da disseminação da doença, objetivou-se com este trabalho determinar a prevalência de anticorpos para o vírus do MV em rebanhos de ovinos Rabo Largo criados no norte do Ceará. Para tanto, foram avaliados 64 ovinos oriundos da Fazenda Experimental Vale do Acaraú, localizada no município de Sobral-CE. Os resultados foram obtidos pela microtécnica de imunodifusão em gel de agarose e Western Blot. As amostras sanguíneas apresentaram resultados negativos para a prevalência de anticorpos do Maedi-Visna. Conclui-se com estes resultados que o rebanho está livre da infecção da MV, entretanto os órgãos fiscalizadores devem manter a vigilância para evitar a entrada dessa enfermidade nos rebanhos ovinos naturalizados. Abstract: Maedi-visna (MV) is a disease of sheep caused by lentiviruses, responsible for a progressive, slow and persistent infection. Economic losses are reproductive failure, death, decreased milk production and weight loss of animals. The disease was introduced in Brazil through the importation of exotic breeds infected. Based on the increased risk of spread of the disease, the aim of this work was to determine the prevalence of antibodies to the virus MV in Rabo Largo sheep flocks created in northern Ceará. Thus, we evaluated 64 sheep from the Experimental Farm Acaraú Valley, located in the city of Sobral-CE. The results were obtained by agar-gel immunodiffusion and Western Blot. The blood samples were negative for the prevalence of antibodies to Maedi-Visna. We conclude from these results that the herd is free of infection by MV, but the supervising agencies must remain vigilant to prevent the entry of this disease in sheep flocks naturalized

Innovation in Brazilian Industries: Analysis of Management Practices Using Fuzzy TOPSIS

This study examined the practices of innovation management used by Brazilian industries. A survey was carried out with specialists that assessed 27 practices (PR) proposed by ISO 56002, considering two types of firms: small and medium-sized industries (SMI) and large industries (LI). The methodological approach included Hierarchical Cluster Analysis to identify the similarities between the specialists and define levels of specialists, as well as Fuzzy TOPSIS and frequency and sensitivity analyses to examine their responses. PR1 (analysis of internal and external issues that impact innovation management) was deemed the best practice for LIs, whereas PR10 (adequate assessment of potential partnerships) was best evaluated for SMIs. The PR27 (periodic audits to identify opportunities for improvement) received the lowest rating from both LIs and SMIs. In general, SMIs in the Brazilian context have more severe deficiencies in terms of applying innovation management practices than LIs. A broad overview of the innovation practices adopted in the Brazilian industrial scenario is provided. The study’s findings may assist managers and policymakers to develop initiatives and actions to improve the capacity of Brazilian industries to innovate. This research can also support future studies aimed at better understanding specific practices related to the topic

Assessing tension metrics with dark energy survey and Planck data

Lemos, P. et al.Quantifying tensions – inconsistencies amongst measurements of cosmological parameters by different experiments – has emerged as a crucial part of modern cosmological data analysis. Statistically significant tensions between two experiments or cosmological probes may indicate new physics extending beyond the standard cosmological model and need to be promptly identified. We apply several tension estimators proposed in the literature to the dark energy survey (DES) large-scale structure measurement and Planck cosmic microwave background data. We first evaluate the responsiveness of these metrics to an input tension artificially introduced between the two, using synthetic DES data. We then apply the metrics to the comparison of Planck and actual DES Year 1 data. We find that the parameter differences, Eigentension, and Suspiciousness metrics all yield similar results on both simulated and real data, while the Bayes ratio is inconsistent with the rest due to its dependence on the prior volume. Using these metrics, we calculate the tension between DES Year 1 3 × 2pt and Planck, finding the surveys to be in ∼2.3σ tension under the ΔCDM paradigm. This suite of metrics provides a toolset for robustly testing tensions in the DES Year 3 data and beyond.The DES data management system is supported by the National Science Foundation under grant numbers AST-1138766 and AST-1536171. The DES participants from Spanish institutions are partially supported by Ministerio de Ciencia e Innovación (MICINN) under grants ESP2017-89838, PGC2018-094773, PGC2018-102021, SEV-2016-0588, SEV-2016-0597, and MDM-2015-0509, some of which include ERDF funds from the European Union. IFAE is partially funded by the Centres de Recerca de Catalunya (CERCA) program of the Generalitat de Catalunya. Research leading to these results has received funding from the European Research Council under the European Union’s Seventh Framework Program (FP7/2007-2013) including ERC grant agreements 240672, 291329, and 306478. We acknowledge support from the Brazilian Instituto Nacional de Ciência e Tecnologia (INCT) do e-Universo (CNPq grant 465376/2014-2). This manuscript has been authored by Fermi Research Alliance, LLC under Contract No. DE-AC02-07CH11359 with the U.S. Department of Energy, Office of Science, Office of High Energy Physics

On the rise of proton-proton cross-sections at high energies

The rise of the total, elastic and inelastic hadronic cross sections at high energies is investigated by means of an analytical parametrization, with the exponent of the leading logarithm contribution as a free fit parameter. Using derivative dispersion relations with one subtraction, two different fits to proton-proton and antiproton-proton total cross section and rho parameter data are developed, reproducing well the experimental information in the energy region 5 GeV - 7 TeV. The parametrization for the total cross sections is then extended to fit the elastic (integrated) cross section data in the same energy region, with satisfactory results. From these empirical results we extract the energy dependence of several physical quantities: inelastic cross section, ratios elastic/total, inelastic/total cross sections, ratio total-cross-section/elastic-slope, elastic slope and optical point. All data, fitted and predicted, are quite well described. We find a statistically consistent solution indicating: (1) an increase of the hadronic cross sections with the energy faster than the log-squared bound by Froissart and Martin; (2) asymptotic limits 1/3 and 2/3 for the ratios elastic/total and inelastic/total cross sections, respectively, a result in agreement with unitarity. These indications corroborate recent theoretical arguments by Ya. I. Azimov on the rise of the total cross section.Comment: 35 pages, 12 figures, discussions improved with further clarifications, references added and updated, one note added, results and conclusions unchanged. Version to be published in J. Phys. G: Nucl. Part. Phy