526 research outputs found

    A complete checklist with new records and geographical distribution of the rove beetles (Coleoptera, Staphylinidae) of Brazil

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    This paper presents the first comprehensive list of 2,688 species of Staphylinidae (Coleoptera) recorded from Brazil. The list is based on the taxonomic and ecological literature, and new records from some insect collections, and includes locality references for each species. In addition, Brazilian localities and the country-level distribution outside of Brazil are provided for each species. Brazilian localities are organized by state, and include the bibliographic reference and page number where each locality was reported. All localities are geo-referenced, organized by state, and listed in an Appendix.Este trabalho apresenta a primeira lista completa das 2.688 espécies de Staphylinidae (Coleoptera) registradas para o Brasil. A lista inclui todas as localidades citadas para cada espécie e baseia-se na literatura taxonômica e ecológica disponíveis. Cada localidade inclui a referência bibliográfica e o número da página onde foram citadas. Também são apresentados registros inéditos obtidos de algumas coleções de insetos. Além das localidades brasileiras são citados todos os países com ocorrência conhecida para cada espécie. As localidades brasileiras, listadas no Apêndice, estão organizadas por estado e georreferenciadas

    Ponderomotive forces in suprathermal space environments due to cyclotron waves

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    The Washimi and Karpman ponderomotive interaction due to right handed electron wave propagation is evaluated for different space conditions considering low temperature magnetized plasmas described by an isotropic Kappa distribution and with a wave propagation parallel with respect to the background magnetic field. We performed a brief analysis of the influence of the Kappa distribution in the dispersion relations for a low temperature plasma expansion at the lowest order in which the thermal effects are appreciated and without considering the damping characteristics of the wave. The different factors of the ponderomotive force are obtained and analyzed separately as function of the wavenumber, the spectral index κ\kappa, the ratio between the plasma frequency and the gyrofrequency, and the plasma beta. Our results shows an important influence of the non-thermal effects in all the factors of the ponderomotive force for magnetized plasmas, even for low values of the plasma beta. Therefore, we have found that even for nearly cold magnetized plasmas and waves far from the resonances the effect of the kappa parameter in the ponderomotive force cannot be neglected. This suggest a significant role of the Kappa distribution in ponderomotive phenomena of space physics. Also, the effect of the kappa distribution has been evaluated for a wide variety of space environments as the solar wind and the different regions of our magnetosphere. We have also analyzed the role of the non-thermal effect in the induced Washimi and Karpman ponderomotive magnetization and the total power radiated associated with it. Furthermore, we show that the magnitude of the slowly varying induced ponderomotive magnetic field is enhanced as the plasma moves away from thermal equilibrium

    Dissipative stabilization of dark quantum dimers via squeezed vacuum

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    Understanding the mechanism through which an open quantum system exchanges information with an environment is central to the creation and stabilization of quantum states. This theme has been explored recently, with attention mostly focused on system control or environment engineering. Here, we bring these ideas together to describe the many-body dynamics of an extended atomic array coupled to a squeezed vacuum. We show that fluctuations can drive the array into a pure dark state decoupled from the environment. The dark state is obtained for an even number of atoms and consists of maximally entangled atomic pairs, or dimers, that mimic the behavior of the squeezed field. Each pair displays reduced fluctuations in one polarization quadrature and amplified in another. This dissipation-induced stabilization relies on an efficient transfer of correlations between pairs of photons and atoms. It uncovers the mechanism through which squeezed light causes an atomic array to self-organize and illustrates the increasing importance of spatial correlations in modern quantum technologies where many-body effects play a central role

    Magneto-mechanically induced antimicrobial properties of cone-like shaped surfaces

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    Hygienic surfaces that prevent the proliferation of harmful microorganisms are required in a large variety of environments, including medical areas. Novel strategies are being developed to impede microorganisms colonization of surfaces. In this work, Terfenol-D cone-like shaped nanopatterned surfaces are fabricated by sputtering. The bactericidal effect of such surfaces owed to their morphology is increased in combination with an alternating magnetic field, which boosts the mechanical injury caused to the planktonic cells. Bactericidal assays with Gram-negative Escherichia coli are carried out under static (i.e. without any external stimuli) and dynamic (under the application of an alternating magnetic field) conditions for control silicon substrates, Terfenol-D films and nanostructured surfaces. The nanostructured surfaces at the dynamic condition exhibit the larger bactericidal effect. Bacterial adhesion on the materials was analyzed, and results show a reduction of the attachment surface of bacterial cells on Terfenol-D surfaces in comparison with the control silicon that are attributed both to material properties and nanostructuration. Thus, this work exhibits a method to induce and/or improve the mechanical antimicrobial behavior of surfaces via application of a magnetic field, as an alternative or in combination with chemical methods, which are losing effectiveness due to the increase of antibiotic resistance.FCT -Fundação para a Ciência e a Tecnologia(P2018/NMT-4321)info:eu-repo/semantics/publishedVersio

    Effect of various dopant elements on primary graphite growth

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    Five spheroidal graphite cast irons were investigated, a usual ferritic grade and four pearlitic alloys containing Cu and doped with Sb, Sn and Ti. These alloys were remelted in a graphite crucible, leading to volatilization of the magnesium added for spheroidization and to carbon saturation of the liquid. The alloys were then cooled down and maintained at a temperature above the eutectic temperature. During this step, primary graphite could develop showing various features depending on the doping elements added. The largest effects were that of Ti which greatly reduces graphite nucleation and growth, and that of Sb which leads to rounded agglomerates instead of lamellar graphite. The samples have been investigated with secondary ion mass spectrometry to enlighten distribution of elements in primary graphite. SIMS analysis showed almost even distribution of elements, including Mg and Al (from the inoculant) in the ferritic grade, while uneven distribution was evident in all doped alloys. Investigations are going on to clarify if the uneven distribution is associated with structural defects in the graphite precipitates

    Copper deposition on fabrics by rf plasma sputtering for medical applications

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    https://www.scopus.com/inward/record.url?eid=2-s2.0-84938151607&partnerID=40&md5=bf2da795caced442546f442aa330773aThe present work is about preparation and characterization of RF sputtered Cu films on cotton by the usage of a Magnetron Sputter Source and 99.995% purity Cu target at room temperature. Cotton fabric samples of 1, 2 and 4 min of sputtering time at discharge pressure of 1×10-2 Torr and distance between target and sample of 8 cm were used. The main goal was to qualitatively test the antimicrobial action of copper on fabrics. For that purpose, a reference strain of Escherichia Coli ATCC 35218 that were grown in TSA plates was implemented. Results indicated a decrease in the growth of bacteria by contact with Cu; for fabric samples with longer sputtering presented lower development of E. coli colonies. The scope of this research focused on using these new textiles in health field, for example socks can be made with this textile for the treatment of athlete's foot and the use in pajamas, sheets, pillow covers and robes in hospital setting for reducing the spread of microorganisms. © Published under licence by IOP Publishing Ltd.Ad Astra Rocket Company,Instituto Tecnologico de Costa Rica,International Atomic Energy Agency (IAEA),Universidad Nacional de Costa Ric
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