677 research outputs found

    Survey Of Acarin Fauna In Dust Samplings Of Curtains In The City Of Campinas, Brazil.

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    The aim of this study was to investigate the mite fauna present in 33 living room and 22 bedroom curtain dust samples from 41 different homes in the southern Brazilian city of Campinas, SP. A total of 148 mite bodies were found. Of these, 83 were found in living-room curtain samples (56.1% of total) and 65 were in bedroom curtain dust samples (43.9%). The most frequently observed mite suborders were: Acaridida (n = 79; 53.4%), Actinedida (n=53; 35.8%), Oribatida (n=14; 9.5%), and Gamasida (n=2; 1.3%). The most frequent families were Pyroglyphidae (n=61; 41.2%), Eriophyidae (n=25; 16.9%), Tarsonemidae (n=15; 10.1%), and Glycyphagidae (n=13; 8.8%). No statistical difference was observed between the number of mites found in the samples from living room and bedroom curtains.651252

    ARXPS analysis of a GaAs/GaInP heterointerface with application in III-V multijunction solar cells

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    In this contribution, angle-resolved X-ray photoelectron spectroscopy is used to explore the extension and nature of a GaAs/GaInP heterointerface. This bilayer structure constitutes a very common interface in a multilayered III-V solar cell. Our results show a wide indium penetration into the GaAs layer, while phosphorous diffusion is much less important. The physico-chemical nature of such interface and its depth could deleteriously impact the solar cell performance. Our results probe the formation of spurious phases which may profoundly affect the interface behavior

    Open-atmosphere structural depth profiling of multilayer samples of photovoltaic interest using laser-induced plasma spectrometry

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    The present work aims to assess Laser-Induced Plasma Spectrometry (LIPS) as a tool for the characterization of photovoltaic materials. Despite being a well-established technique with applications to many scientific and industrial fields, so far LIPS is little known to the photovoltaic scientific community. The technique allows the rapid characterization of layered samples without sample preparation, in open atmosphere and in real time. In this paper, we assess LIPS ability for the determination of elements that are difficult to analyze by other broadly used techniques, or for producing analytical information from very low-concentration elements. The results of the LIPS characterization of two different samples are presented: 1) a 90 nm, Al-doped ZnO layer deposited on a Si substrate by RF sputtering and 2) a Te-doped GaInP layer grown on GaAs by Metalorganic Vapor Phase Epitaxy. For both cases, the depth profile of the constituent and dopant elements is reported along with details of the experimental setup and the optimization of key parameters. It is remarkable that the longest time of analysis was ∼10 s, what, in conjunction with the other characteristics mentioned, makes of LIPS an appealing technique for rapid screening or quality control whether at the lab or at the production line

    Scope for growth and dietary needs of Mediteranean Pinnids maintained in captivity

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    Abstract Background: The measurement of the energy available for growth (scope of growth, SFG) can be used in bivalves to make a long-term prediction in a short-term experiment of the condition of the individual. In order to tackle the best conditions for captive maintenance of Mediterranean Pinnids, a SFG study was conducted using Pinna rudis as a model species. Three diets were examined to test the viability of live microalgae and commercial products: i) a control diet using 100% of live microalgae based on the species Isochrysis galbana (t-ISO), ii) a 100% of commercial microalgae diet based on the product Shellfish Diet 1800®, and iii) a 50/50% mix diet of I. galbana (t-ISO) and Shellfish Diet 1800®. Results: SFG results showed significant differences among diets in the physiological functions measured and suggested lower acceptability and digestibility of the commercial product. Negative SFG values were obtained for the commercial diet which indicates that it should be rejected for both Pinnid maintenance. The mixed diet showed improved physiological performance compared to the commercial diet, resulting in a higher SFG that had no significant differences with the control diet. However, in the long-term, the lower digestibility of the mixed diet compared to the control diet could lead to a deterioration of individuals’ conditions and should be considered cautiously. Conclusions: This work represents the first case study of SFG in Pinna spp. and provides fundamental data on dietary needs for the critically endangered species, P. nobilis.En prens

    Observers in an accelerated universe

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    If the current acceleration of our Universe is due to a cosmological constant, then a Coleman-De Luccia bubble will nucleate in our Universe. In this work, we consider that our observations could be likely in this framework, consisting in two infinite spaces, if a foliation by constant mean curvature hypersurfaces is taken to count the events in the spacetime. Thus, we obtain and study a particular foliation, which covers the existence of most observers in our part of spacetime.Comment: revised version, accepted in EPJ

    XPS as Characterization Tool for PV: From the Substrate to Complete III-V Multijunction Solar Cells

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    This contribution aims to illustrate the potential of the X-ray photoelectron spectroscopy (XPS) technique as a tool to analyze different parts of a solar cell (surface state, heterointerfaces, profile composition of ohmic contacts, etc). Here, the analysis is specifically applied to III-V multijunction solar cells used in concentrator systems. The information provided from such XPS analysis has helped to understand the physico-chemical nature of these surfaces and interfaces, and thus has guided the technological process in order to improve the solar cell performance
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