336 research outputs found
SiOx Patterned Based Substrates Implemented in Cu(In,Ga)Se2 Ultrathin Solar Cells: Optimum Thickness
Interface recombination in sub-”m optoelectronics has a major detrimental impact on devicesâ performance, showing the need for tailored passivation strategies to reach a technological boost. In this work, SiOx passivation based substrates were developed and integrated into ultrathin Cu(In,Ga)Se2 (CIGS) solar cells. This study aims to understand the impact of a passivation strategy, which uses several SiOx layer thicknesses (3, 8, and 25 nm) integrated into high performance substrates (HPS). The experimental study is complemented with 3D Lumerical finite-difference time-domain (FDTD) and 2D Silvaco ATLAS optical and electrical simulations, respectively, to perform a decoupling of optical and electronic gains, allowing for a deep discussion on the impact of the SiOx layer thickness in the CIGS solar cell performance. This study shows that as the passivation layer thickness increases, a rise in parasitic losses is observed. Hence, a balance between beneficial passivation and optical effects with harmful architectural constraints defines a threshold thickness to attain the best solar cell performance. Analyzing their electrical parameters, the 8 nm novel SiOx based substrate achieved a light to power conversion efficiency value of 13.2 %, a 1.3 % absolute improvement over the conventional Mo substrate (without SiOx).info:eu-repo/semantics/submittedVersio
Diversity of ferns and lycophytes in Brazil
This compilation of ferns and lycophytes in Brazil is an update of the one published in 2010 in CatĂĄlogo de Plantas e Fungos do Brasil. The methodology consisted in collecting data from regional checklists, taxonomic revisions, and selected databases. Invited specialists improved the list accessing a website housed at the Jardim BotĂąnico do Rio de Janeiro. The results show 1,253 species: 1,111 of ferns and 142 of lycophytes. This number is 6.5% higher than the previous one (1,176 spp.). The percentage of endemic species decreased from 38.2% to 36.7%. We recognized 36 families and 133 genera (vs. 33 families, 121 genera in 2010). The 10 most diverse families are Pteridaceae (196 spp.), Dryopteridaceae (179), Polypodiaceae (164), Hymenophyllaceae (90), Thelypteridaceae (86), Aspleniaceae (78), Lycopodiaceae (64), Selaginellaceae (55), Anemiaceae (51), and Cyatheaceae (45). The three most diverse genera are still Elaphoglossum (87 spp.), Thelypteris (85), and Asplenium (74). The richest phytogeographic domain continues to be in the Atlantic Rainforest with 883 species which also has the largest number of endemic and threatened species, followed by the Amazon Rainforest (503), Cerrado (269), Pantanal (30), Caatinga (26), and Pampa (eight). Minas Gerais remains as the richest state (657 spp. vs. 580 in 2010).Esta compilação de samambaias e licĂłfitas do Brasil Ă© uma atualização daquela de 2010, no CatĂĄlogo de Plantas e Fungos do Brasil. A metodologia consistiu na reuniĂŁo de dados de listas regionais, revisĂ”es de grupos e bancos de dados selecionados. Especialistas convidados melhoraram a lista atravĂ©s do acesso a um sĂtio da web do Jardim BotĂąnico do Rio Janeiro. Os resultados apontam uma diversidade de 1.253 espĂ©cies, sendo 1.111 samambaias e 142 licĂłfitas. Este nĂșmero Ă© 6,5% maior que o anterior (1.176 espĂ©cies). As espĂ©cies endĂȘmicas decresceram de 38,2% para 36,7%. Foram reconhecidas 36 famĂlias e 133 gĂȘneros (vs. 33 famĂlias, 121 gĂȘneros em 2010). As dez famĂlias mais diversas sĂŁo: Pteridaceae (196 espĂ©cies), Dryopteridaceae (179), Polypodiaceae (164), Hymenophyllaceae (90), Thelypteridaceae (86), Aspleniaceae (78), Lycopodiaceae (64), Selaginellaceae (55), Anemiaceae (51) e Cyatheaceae (45). Os trĂȘs gĂȘneros mais diversos continuam sendo Elaphoglossum (87 espĂ©cies), Thelypteris (85) e Asplenium (74). O DomĂnio FitogeogrĂĄfico mais rico continua sendo a Mata AtlĂąntica (883 espĂ©cies) e tambĂ©m com mais espĂ©cies endĂȘmicas e ameaçadas, seguido pela AmazĂŽnia (503 espĂ©cies), Cerrado (269), Pantanal (30), Caatinga (26) e Pampa (oito). Minas Gerais permanece como o estado com maior riqueza (657 espĂ©cies vs. 580 em 2010)
Blood-Feeding Induces Reversible Functional Changes in Flight Muscle Mitochondria of Aedes aegypti Mosquito
Background: Hematophagy poses a challenge to blood-feeding organisms since products of blood digestion can exert
cellular deleterious effects. Mitochondria perform multiple roles in cell biology acting as the site of aerobic energytransducing
pathways, and also an important source of reactive oxygen species (ROS), modulating redox metabolism.
Therefore, regulation of mitochondrial function should be relevant for hematophagous arthropods. Here, we investigated
the effects of blood-feeding on flight muscle (FM) mitochondria from the mosquito Aedes aegypti, a vector of dengue and
yellow fever.
Methodology/Principal Findings: Blood-feeding caused a reversible reduction in mitochondrial oxygen consumption, an
event that was parallel to blood digestion. These changes were most intense at 24 h after blood meal (ABM), the peak of
blood digestion, when oxygen consumption was inhibited by 68%. Cytochromes c and a+a3 levels and cytochrome c
oxidase activity of the electron transport chain were all reduced at 24 h ABM. Ultrastructural and molecular analyses of FM
revealed that mitochondria fuse upon blood meal, a condition related to reduced ROS generation. Consistently, BF induced
a reversible decrease in mitochondrial H2O2 formation during blood digestion, reaching their lowest values at 24 h ABM
where a reduction of 51% was observed.
Conclusion: Blood-feeding triggers functional and structural changes in hematophagous insect mitochondria, which may
represent an important adaptation to blood feedin
Measurement of the cosmic ray spectrum above eV using inclined events detected with the Pierre Auger Observatory
A measurement of the cosmic-ray spectrum for energies exceeding
eV is presented, which is based on the analysis of showers
with zenith angles greater than detected with the Pierre Auger
Observatory between 1 January 2004 and 31 December 2013. The measured spectrum
confirms a flux suppression at the highest energies. Above
eV, the "ankle", the flux can be described by a power law with
index followed by
a smooth suppression region. For the energy () at which the
spectral flux has fallen to one-half of its extrapolated value in the absence
of suppression, we find
eV.Comment: Replaced with published version. Added journal reference and DO
Energy Estimation of Cosmic Rays with the Engineering Radio Array of the Pierre Auger Observatory
The Auger Engineering Radio Array (AERA) is part of the Pierre Auger
Observatory and is used to detect the radio emission of cosmic-ray air showers.
These observations are compared to the data of the surface detector stations of
the Observatory, which provide well-calibrated information on the cosmic-ray
energies and arrival directions. The response of the radio stations in the 30
to 80 MHz regime has been thoroughly calibrated to enable the reconstruction of
the incoming electric field. For the latter, the energy deposit per area is
determined from the radio pulses at each observer position and is interpolated
using a two-dimensional function that takes into account signal asymmetries due
to interference between the geomagnetic and charge-excess emission components.
The spatial integral over the signal distribution gives a direct measurement of
the energy transferred from the primary cosmic ray into radio emission in the
AERA frequency range. We measure 15.8 MeV of radiation energy for a 1 EeV air
shower arriving perpendicularly to the geomagnetic field. This radiation energy
-- corrected for geometrical effects -- is used as a cosmic-ray energy
estimator. Performing an absolute energy calibration against the
surface-detector information, we observe that this radio-energy estimator
scales quadratically with the cosmic-ray energy as expected for coherent
emission. We find an energy resolution of the radio reconstruction of 22% for
the data set and 17% for a high-quality subset containing only events with at
least five radio stations with signal.Comment: Replaced with published version. Added journal reference and DO
Licenciamento ambiental e ampliação da cidadania: o caso da hidrelétrica de Tijuco Alto
Desafios polĂticos para a consolidação do Sistema Ănico de SaĂșde: uma abordagem histĂłrica
Early and Late Pathogenic Events of Newborn Mice Encephalitis Experimentally Induced by Itacaiunas and CurionĂłpolis Bracorhabdoviruses Infection
In previous reports we proposed a new genus for Rhabdoviridae and described neurotropic preference and gross neuropathology in newborn albino Swiss mice after Curionopolis and Itacaiunas infections. In the present report a time-course study of experimental encephalitis induced by Itacaiunas and Curionopolis virus was conducted both in vivo and in vitro to investigate cellular targets and the sequence of neuroinvasion. We also investigate, after intranasal inoculation, clinical signs, histopathology and apoptosis in correlation with viral immunolabeling at different time points. Curionopolis and Itacaiunas viral antigens were first detected in the parenchyma of olfactory pathways at 2 and 3 days post-inoculation (dpi) and the first clinical signs were observed at 4 and 8 dpi, respectively. After Curionopolis infection, the mortality rate was 100% between 5 and 6 dpi, and 35% between 8 and 15 dpi after Itacaiunas infection. We identified CNS mice cell types both in vivo and in vitro and the temporal sequence of neuroanatomical olfactory areas infected by Itacaiunas and Curionopolis virus. Distinct virulences were reflected in the neuropathological changes including TUNEL immunolabeling and cytopathic effects, more intense and precocious after intracerebral or in vitro inoculations of Curionopolis than after Itacaiunas virus. In vitro studies revealed neuronal but not astrocyte or microglial cytopathic effects at 2 dpi, with monolayer destruction occurring at 5 and 7 dpi with Curionopolis and Itacaiunas virus, respectively. Ultrastructural changes included virus budding associated with interstitial and perivascular edema, endothelial hypertrophy, a reduced and/or collapsed small vessel luminal area, thickening of the capillary basement membrane, and presence of phagocytosed apoptotic bodies. Glial cells with viral budding similar to oligodendrocytes were infected with Itacaiunas virus but not with Curionopolis virus. Thus, Curionopolis and Itacaiunas viruses share many pathological and clinical features present in other rhabdoviruses but distinct virulence and glial targets in newborn albino Swiss mice brain
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