877 research outputs found

    WO3-Doped Indium Oxide Thick Films for Ozone Detection at Low Temperature

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    Ozone, a strong oxidizing gas, has dramatically increased its concentration in the troposphere during the last decades. Since high O3 concentrations are hazardous to human health, the development of effective methods and economic devices to detect this gas is an urgent need. In this frame, In2O3 is well known as an n-type ozone sensitive and selective material, generally displaying its optimal sensing capability in the temperature range 200–350 °C. To enhance the sensing capability of In2O3 and to decrease its operative temperature, in this work, commercial In2O3 powders were doped with 2.5 wt. % WO3. Pure and doped-In2O3 materials were used to develop sensing devices by screen-printing technology. Resistance measurements were performed in the temperature range 25 °C–150 °C under 200–500 ppb O3. Best results were obtained at 75 °C with sensor’s responses as high as 40 under 200 ppb of ozone

    Taxonomic approach to the tachinid flies Dinera carinifrons (Fallén) (Diptera: Tachinidae) and Dinera fuscata Zhang and Shima using molecular and morphometric data

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    Molecular phylogenetic and traditional morphometric methods were applied to examine six Palaearctic taxa of the taxonomically difficult tachinid fly genus Dinera Robineau-Desvoidy (Diptera: Tachinidae), with particular reference to D. carinifrons (Fallén) and D. fuscata Zhang and Shima. Results of a phylogenetic analysis based on the mitochondrial markers 12S and 16S rDNA and multivariate statistical analyses of 19 morphometric characters were used to delimit both species. A lectotype was designated for D. carinifrons to stabilize the nomenclature in the group. Dinera carinifrons has a transpalaearctic distribution and is present in Central Europe, especially in high altitudes of the Alps. It differs from the similar and closely related D. fuscata in that it has a slightly larger body size, a dense greyish microtrichosity on the body, and different head proportions. Dinera fuscata, as delimited here, is widespread in the Palaearctic region, including Europe. Slight differences in both molecular and morphometric characters were found between western (Europe and Iran) and eastern (China and Japan) populations of D. fuscata, which are interpreted as an intraspecific variation. Differential diagnosis between D. carinifrons and D. fuscata is provided in the form of a revised portion of the determination key to the Palaearctic Dinera by Zhang and Shima (2006). CETPO project CZ.1.07/2.3.00/20.0166 (partly).Molekulárně fylogenetické a tradiční morfometrické metody byly využity ke studiu šesti palearktických druhů tachin rodu Dinera Robineau-Desvoidy (Diptera: Tachinidae), se zvláštním zřetelem na D. carinifrons (Fallén) a D. fuscata Zhang a Shima. Částečně i CETPO project CZ.1.07/2.3.00/20.0166

    Supernova limits on muonic dark forces

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    Protoneutron stars formed during core-collapse supernovae are hot and dense environments that contain a sizable population of muons. If these interact with new long-lived particles with masses up to roughly 100 MeV, the latter can be produced and escape from the stellar plasma, causing an excessive energy loss constrained by observations of SN 1987A. In this article we calculate the emission of light dark fermions that are coupled to leptons via a new massive vector boson, and determine the resulting constraints on the general parameter space. We apply these limits to the gauged LμLτL_μ−L_τ model with dark fermions, and show that the SN 1987A constraints exclude a significant portion of the parameter space targeted by future experiments. We also extend our analysis to generic effective four-fermion operators that couple dark fermions to muons, electrons, or neutrinos. We find that SN 1987A cooling probes a new physics scale up to 7  TeV∼7  TeV, which is an order of magnitude larger than current bounds from laboratory experiments

    Supernova limits on muonic dark forces

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    Proto-neutron stars formed during core-collapse supernovae are hot and dense environments that contain a sizable population of muons. If these interact with new long-lived particles with masses up to roughly 100 MeV, the latter can be produced and escape from the stellar plasma, causing an excessive energy loss constrained by observations of SN 1987A. In this article we calculate the emission of light dark fermions that are coupled to leptons via a new massive vector boson, and determine the resulting constraints on the general parameter space. We apply these limits to the gauged LμLτL_μ−L_τ model with dark fermions, and show that the SN 1987A constraints exclude a significant portion of the parameter space targeted by future experiments. We also extend our analysis to generic effective four-fermion operators that couple dark fermions to muons, electrons, or neutrinos. We find that SN 1987A cooling probes a new-physics scale up to 7TeV∼7 TeV, which is an order of magnitude larger than current bounds from laboratory experiments

    Supernova Limits on Muonic Dark Forces

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    Proto-neutron stars formed during core-collapse supernovae are hot and dense environments that contain a sizable population of muons. If these interact with new long-lived particles with masses up to roughly 100 MeV, the latter can be produced and escape from the stellar plasma, causing an excessive energy loss constrained by observations of SN 1987A. In this article we calculate the emission of light dark fermions that are coupled to leptons via a new massive vector boson, and determine the resulting constraints on the general parameter space. We apply these limits to the gauged LμLτL_\mu-L_\tau model with dark fermions, and show that the SN 1987A constraints exclude a significant portion of the parameter space targeted by future experiments. We also extend our analysis to generic effective four-fermion operators that couple dark fermions to muons, electrons, or neutrinos. We find that SN 1987A cooling probes a new-physics scale up to 7\sim7 TeV, which is an order of magnitude larger than current bounds from laboratory experiments.Comment: 25 pages, 6 Figures, 1 Table, python code for numerical analysis available under the following url: https://github.com/spinjo/SNforMuTau.gi

    The Image 2001: RU Ready?

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    Rowan University yearbook for the Class of 2001; 212 pages. Contents: Opening p. 1, Homecoming p. 2, Seniors p. 17, Student Life p. 80A, Camden Campus p. 103, Organizations p. 112A, Athletics p. 144A, President\u27s Address p. 177, Faculty, Staff & Administration p. 179, Graduation p. 189. Editor-in-Chief Andrea L. Pujat; Advisor Ed Ziegler.https://rdw.rowan.edu/yearbooks/1025/thumbnail.jp

    Engineering method for tailoring electrical characteristics in TiN/TiOx/HfOx/Au Bi-layer oxide memristive devices

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    Memristive devices have led to an increased interest in neuromorphic systems. However, different device requirements are needed for the multitude of computation schemes used there. While linear and time-independent conductance modulation is required for machine learning, non-linear and time-dependent properties are necessary for neurobiologically realistic learning schemes. In this context, an adaptation of the resistance switching characteristic is necessary with regard to the desired application. Recently, bi-layer oxide memristive systems have proven to be a suitable device structure for this purpose, as they combine the possibility of a tailored memristive characteristic with low power consumption and uniformity of the device performance. However, this requires technological solutions that allow for precise adjustment of layer thicknesses, defect densities in the oxide layers, and suitable area sizes of the active part of the devices. For this purpose, we have investigated the bi-layer oxide system TiN/TiOx/HfOx/Au with respect to tailored I-V non-linearity, the number of resistance states, electroforming, and operating voltages. Therefore, a 4-inch full device wafer process was used. This process allows a systematic investigation, i.e., the variation of physical device parameters across the wafer as well as a statistical evaluation of the electrical properties with regard to the variability from device to device and from cycle to cycle. For the investigation, the thickness of the HfOx layer was varied between 2 and 8 nm, and the size of the active area of devices was changed between 100 and 2,500 µm2. Furthermore, the influence of the HfOx deposition condition was investigated, which influences the conduction mechanisms from a volume-based, filamentary to an interface-based resistive switching mechanism. Our experimental results are supported by numerical simulations that show the contribution of the HfOx film in the bi-layer memristive system and guide the development of a targeting device

    Mixed infections with Chlamydia and porcine epidemic diarrhea virus - a new in vitro model of chlamydial persistence

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    BACKGROUND: Chlamydiae induce persistent infections, which have been associated with a wide range of chronic diseases in humans and animals. Mixed infections with Chlamydia and porcine epidemic diarrhea virus (PEDV) may result in generation of persistent chlamydial infections. To test this hypothesis, an in vitro model of dual infection with cell culture-adapted PEDV and Chlamydia abortus or Chlamydia pecorum in Vero cells was established. RESULTS: Infected cultures were investigated by immunofluorescence (IF), transmission electron microscopy (TEM) and re-infection experiments. By IF, Chlamydia-infected cells showed normal inclusions after 39 hpi. Dual infections with Chlamydia abortus revealed a heterogenous mix of inclusion types including small inclusions consisting of aberrant bodies (ABs), medium-sized inclusions consisting of ABs and reticulate bodies and normal inclusions. Only aberrant inclusions were observable in dual infection experiments with Chlamydia pecorum and PEDV. TEM examinations of mixed infections with Chlamydia abortus and Chlamydia pecorum revealed aberrant chlamydial inclusions containing reticulate-like, pleomorphic ABs, which were up to 2 microm in diameter. No re-differentiation into elementary bodies (EBs) was detected. In re-infection experiments, co-infected cells produced fewer EBs than monoinfected cells. CONCLUSIONS: In the present study we confirm that PEDV co-infection alters the developmental cycle of member species of the family Chlamydiaceae, in a similar manner to other well-described persistence induction methods. Interestingly, this effect appears to be partially species-specific as Chlamydia pecorum appears more sensitive to PEDV co-infection than Chlamydia abortus, as evidenced by TEM and IF observations of a homogenous population of aberrant inclusions in PEDV - Chlamydia pecorum co-infections

    Compositional changes in cell wall polysaccharides from japanese plum (Prunus salicina Lindl.) during growth and On-Tree ripening

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    Climacteric Japanese plums were harvested at six developmental stages with no Intermediate storage period, and cell wall compositional changes were analyzed. Arabinose proved to be the principal neutral monosaccharide constituent in cell walls during growth and the most dynamic neutral sugar in pectic fractions. Arabinose loss from tightly bound pectins was found to be a relatively early feature in the sequence of cell wall biochemical modifications, thus suggesting a softening-related role during Japanese plum on-tree ripening. Depolymerization of matrix glycans started at the end of the cell expansion phase and increased throughout ripening. Pectin solubilization was first detected during early ripening. Firmness loss did not correlate with polyuronide depolymerization early In ripening, but the last softening phase was associated with a strong depolymerization of cell wall polyuronides as well as a decrease In the arabinose/galactose ratio In loosely bound pectins. This Is the first work that characterizes the temporal sequence of cell wall polysaccharide changes in Japanese plum.Fil: Ponce, Nora Marta Andrea. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Centro de Investigaciones en Hidratos de Carbono. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Centro de Investigaciones en Hidratos de Carbono; ArgentinaFil: Ziegler, Victor H.. Universidad de Buenos Aires. Facultad de Agronomía. Departamento de Producción Vegetal; ArgentinaFil: Stortz, Carlos Arturo. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Centro de Investigaciones en Hidratos de Carbono. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Centro de Investigaciones en Hidratos de Carbono; ArgentinaFil: Sozzi, Gabriel Oscar. Universidad de Buenos Aires. Facultad de Agronomía. Departamento de Producción Vegetal; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin
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