59 research outputs found

    Karty kontrolne obrazem zmienności procesu

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    Jednym z najważniejszych elementów badania każdego procesu jest analiza zmienności i wizualizacja zebranych danych. To właśnie zobrazowanie uzyskanych pomiarów na właściwym wykresie czyni decyzje lepszymi i trafniejszymi. W artykule zostało przedstawionych szereg klasycznych i sekwencyjnych kart kontrolnych. Zdaniem autora, zawarte w nich informacje powinny ułatwić dobór kart w zależności od rodzaju badanego procesu lub ilości prób, za pomocą których realizowana będzie analiza stabilności

    Two-gap and paramagnetic pair-breaking effects on upper critical field of SmFeAsO0.85_{0.85} and SmFeAsO0.8_{0.8}F0.2_{0.2} single crystals

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    We investigated the temperature dependence of the upper critical field [Hc2(T)H_{c2}(T)] of fluorine-free SmFeAsO0.85_{0.85} and fluorine-doped SmFeAsO0.8_{0.8}F0.2_{0.2} single crystals by measuring the resistive transition in low static magnetic fields and in pulsed fields up to 60 T. Both crystals show that Hc2(T)H_{c2}(T)'s along the c axis [Hc2c(T)H_{c2}^c(T)] and in an abab-planar direction [Hc2ab(T)H_{c2}^{ab}(T)] exhibit a linear and a sublinear increase, respectively, with decreasing temperature below the superconducting transition. Hc2(T)H_{c2}(T)'s in both directions deviate from the conventional one-gap Werthamer-Helfand-Hohenberg theoretical prediction at low temperatures. A two-gap nature and the paramagnetic pair-breaking effect are shown to be responsible for the temperature-dependent behavior of Hc2cH_{c2}^c and Hc2abH_{c2}^{ab}, respectively.Comment: 21 pages, 8 figure

    Analysis of Ignition Capability of Flammable Gases from Small Arms Propellant Gases

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    The article presents the results of tests on the temperature of propellant gases shortly after the bullet leaves the barrel. The temperature and movement of these gases were recorded with thermal cameras and a high-speed camera. Weapons with and without muzzle devices (flash suppressor, silencer) were used. The aim of the research was to check the capability to ignite flammable gases located in the vicinity of the propellant gases produced during firing. Comparison of the maximum temperature of the propellant gases and the ignition temperature of the flammable gases makes it possible to determine the probability of fire. The lowest temperature of propellant gases was in the case of shooting with 9 19 mm bullets with the lowest kinetic energy (518 J), and the highest temperature of these gases was during shooting with 5.56 45 mm HC (SS109) bullets with the highest kinetic energy (1,785 J)

    Z3_{3}-vestigial nematic order due to superconducting fluctuations in the doped topological insulators Nbx_{x}Bi2_{2}Se3_{3} and Cux_{x}Bi2_{2}Se3_{3}

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    A state of matter with a multi-component order parameter can give rise to vestigial order. In the vestigial phase, the primary order is only partially melted, leaving a remaining symmetry breaking behind, an effect driven by strong classical or quantum fluctuations. Vestigial states due to primary spin and charge-density-wave order have been discussed in iron-based and cuprate materials. Here we present the observation of a partially melted superconductivity in which pairing fluctuations condense at a separate phase transition and form a nematic state with broken Z3_{3}, i.e., three-state Potts-model symmetry. Thermal expansion, specific heat and magnetization measurements of the doped topological insulators Nbx_{x}Bi2_{2}Se3_{3} and Cux_{x}Bi2_{2}Se3_{3} reveal that this symmetry breaking occurs at Tnem_{nem}≃3.8K above Tc_{c}≃3.25K, along with an onset of superconducting fluctuations. Thus, before Cooper pairs establish long-range coherence at Tc_{c}, they fluctuate in a way that breaks the rotational invariance at Tnem_{nem} and induces a crystalline distortion

    Non‐Destructive X‐Ray Imaging of Patterned Delta‐Layer Devices in Silicon

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    The progress of miniaturization in integrated electronics has led to atomic and nanometer-sized dopant devices in silicon. Such structures can be fabricated routinely by hydrogen resist lithography, using various dopants such as P and As. However, the ability to non-destructively obtain atomic-species-specific images of the final structure, which would be an indispensable tool for building more complex nano-scale devices, such as quantum co-processors, remains an unresolved challenge. Here, X-ray fluorescence is exploited to create an element-specific image of As dopants in Si, with dopant densities in absolute units and a resolution limited by the beam focal size (here ≈1 µm), without affecting the device's low temperature electronic properties. The As densities provided by the X-ray data are compared to those derived from Hall effect measurements as well as the standard non-repeatable, scanning tunneling microscopy and secondary ion mass spectroscopy, techniques. Before and after the X-ray experiments, we also measured the magneto-conductance, which is dominated by weak localization, a quantum interference effect extremely sensitive to sample dimensions and disorder. Notwithstanding the 1.5 × 10^{10} Sv (1.5 × 10^{16} Rad cm^{−2}) exposure of the device to X-rays, all transport data are unchanged to within experimental errors, corresponding to upper bounds of 0.2 Angstroms for the radiation-induced motion of the typical As atom and 3% for the loss of activated, carrier-contributing dopants. With next generation synchrotron radiation sources and more advanced optics, the authors foresee that it will be possible to obtain X-ray images of single dopant atoms within resolved radii of 5 nm

    Switching of magnetic domains reveals evidence for spatially inhomogeneous superconductivity

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    The interplay of magnetic and charge fluctuations can lead to quantum phases with exceptional electronic properties. A case in point is magnetically-driven superconductivity, where magnetic correlations fundamentally affect the underlying symmetry and generate new physical properties. The superconducting wave-function in most known magnetic superconductors does not break translational symmetry. However, it has been predicted that modulated triplet p-wave superconductivity occurs in singlet d-wave superconductors with spin-density wave (SDW) order. Here we report evidence for the presence of a spatially inhomogeneous p-wave Cooper pair-density wave (PDW) in CeCoIn5. We show that the SDW domains can be switched completely by a tiny change of the magnetic field direction, which is naturally explained by the presence of triplet superconductivity. Further, the Q-phase emerges in a common magneto-superconducting quantum critical point. The Q-phase of CeCoIn5 thus represents an example where spatially modulated superconductivity is associated with SDW order

    Design and performance of the multiplexing spectrometer CAMEA

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    The cold neutron multiplexing secondary spectrometer CAMEA (Continuous Angle Multiple Energy Analysis) was commissioned at the Swiss spallation neutron source SINQ at the Paul Scherrer Institut at the end of 2018. The spectrometer is optimised for an efficient data collection in the horizontal scattering plane, allowing for detailed and rapid mapping of excitations under extreme conditions. The novel design consists of consecutive, upward scattering analyzer arcs underneath an array of position sensitive detectors mounted inside a low permeability stainless-steel vacuum vessel. The construction of the world's first continuous angle multiple energy analysis instrument required novel solutions to many technical challenges, including analyzer mounting, vacuum connectors, and instrument movement. These were solved by extensive prototype experiments and in-house developments. Here we present a technical overview of the spectrometer describing in detail the engineering solutions and present our first experimental data taken during the commissioning. Our results demonstrate the tremendous gains in data collection rate for this novel type of spectrometer design
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