167 research outputs found

    A neutron diffraction study of macroscopically entangled proton states in the high temperature phase of the KHCO3 crystal at 340 K

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    International audienceWe utilize single-crystal neutron diffraction to study the C2/mC2/m structure of potassium hydrogen carbonate (KHCO3_3) and macroscopic quantum entanglement above the phase transition at Tc=318T_c = 318 K. Whereas split atom sites could be due to disorder, the diffraction pattern at 340 K evidences macroscopic proton states identical to those previously observed below TcT_c by F. Fillaux et al., (2006 \textit{J. Phys.: Condens. Matter} \textbf{18} 3229). We propose a theoretical framework for decoherence-free proton states and the calculated differential cross-section accords with observations. The structural transition occurs from one ordered P21/aP2_1/a structure (T<TcT < T_c) to another ordered C2/mC2/m structure. There is no breakdown of the quantum regime. It is suggested that the crystal is a macroscopic quantum object which can be represented by a state vector. Raman spectroscopy and quasi-elastic neutron scattering suggest that the ∣C2/m⟩|C2/m\rangle state vector is a superposition of the state vectors for two P21/aP2_1/a-like structures symmetric with respect to (a,c)(a,c) planes

    Application Of Logistics Simulations For Scaling Up A Semiconductor Pilot Line: A Case Study

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    Our study presents a comprehensive approach to upscaling pilot lines in the semiconductor industry, combining logistics simulation with discrete event simulation (DES) to achieve operational excellence. Based on both existing literature and partner company requirements, our five-step methodology facilitated the transition of a pilot line to medium-volume series production within a brownfield factory environment. We validated the effectiveness of DES in production planning and control (PPC) and demonstrated its application in a real-world planning task encompassing multiple facets of production system planning and optimization. Given the expected increase in brownfield factory planning within the semiconductor industry, our structured methodology provides a valuable pathway to enhance operational efficiency and competitiveness in that context. This case study underscores the vital role of DES in optimizing production systems, enabling informed decision-making and significant cost savings

    Evidence of macroscopically entangled protons in a mixed isotope crystal of KHp_{p}D1−p_{1-p}CO3_3

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    International audienceWe examine whether protons and deuterons in the crystal of KH0.76_{0.76}D0.24_{0.24}CO3_3 at 300 K are particles or matter waves. The neutron scattering function measured over a broad range of reciprocal space reveals the enhanced diffraction pattern anticipated for antisymmetrized macroscopic states for protons (fermions). These features exclude a statistical distribution of protons and deuterons. Raman spectra are consistent with a mixture of KHCO3_3 and KDCO3_3 sublattices whose isomorphous structures are independent of the isotope content. We propose a theoretical framework for decoherence-free proton and deuteron states

    Computation of diffuse scattering arising from one-phonon excitations in a neutron time-of-flight single-crystal Laue diffraction experiment

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    Direct phonon excitation in a neutron time-of-flight single-crystal Laue diffraction experiment has been observed in a single crystal of NaCl. At room temperature both phonon emission and excitation leave characteristic features in the diffuse scattering and these are well reproduced using ab initio phonons from density functional theory (DFT). A measurement at 20 K illustrates the effect of thermal population of the phonons, leaving the features corresponding to phonon excitation and strongly suppressing the phonon annihilation. A recipe is given to compute these effects combining DFT results with the geometry of the neutron experiment

    Yes, one can obtain better quality structures from routine X-ray data collection

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    Single-crystal X-ray diffraction structural results for benzidine dihydrochloride, hydrated and protonated N,N,N,N-peri(dimethylamino)naphthalene chloride, triptycene, dichlorodimethyltriptycene and decamethylferrocene have been analysed. A critical discussion of the dependence of structural and thermal parameters on resolution for these compounds is presented. Results of refinements against X-ray data, cut off to different resolutions from the high-resolution data files, are compared to structural models derived from neutron diffraction experiments. The Independent Atom Model (IAM) and the Transferable Aspherical Atom Model (TAAM) are tested. The average differences between the X-ray and neutron structural parameters (with the exception of valence angles defined by H atoms) decrease with the increasing 2θmax angle. The scale of differences between X-ray and neutron geometrical parameters can be significantly reduced when data are collected to the higher, than commonly used, 2θmax diffraction angles (for Mo Kα 2θmax > 65°). The final structural and thermal parameters obtained for the studied compounds using TAAM refinement are in better agreement with the neutron values than the IAM results for all resolutions and all compounds. By using TAAM, it is still possible to obtain accurate results even from low-resolution X-ray data. This is particularly important as TAAM is easy to apply and can routinely be used to improve the quality of structural investigations [Dominiak (2015). LSDB from UBDB. University of Buffalo, USA]. We can recommend that, in order to obtain more adequate (more accurate and precise) structural and displacement parameters during the IAM model refinement, data should be collected up to the larger diffraction angles, at least, for Mo Kα radiation to 2θmax = 65° (sin θmax/λ < 0.75 Å−1). The TAAM approach is a very good option to obtain more adequate results even using data collected to the lower 2θmax angles. Also the results of translation–libration–screw (TLS) analysis and vibrational entropy values are more reliable for 2θmax > 65°

    Gambaran Jumlah Trombosit pada Pasien Kanker Serviks di RSU Dokter Soedarso Tahun 2011-2012

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    Latar Belakang: Rata Rata satu koma empat juta wanita di-seluruhdunia hidup dengan kanker serviks. Kanker serviks termasuk dari sepuluhbesar kanker penyebab kematian pada wanita di Indonesia. Hasilpenelitian terkini mengindikasikan adanya hubungan antara tingginyajumlah trombosit dengan prognosis yang buruk dari kanker sistemginekologi. Tujuan: Penelitian ini bertujuan mengetahui bagaimanagambaran jumlah trombosit pada pasien kanker serviks. Metodologi:Penelitian adalah penelitian deskriptif. Pengumpulan data dilakukan dibagian rekam medis RSU DOKTER SOEDARSO pada tanggal 25 Maretsampai 3 Mei 2013. Data dikumpulkan dari buku registrasi rawat inap danrawat jalan di poli obstetri dan ginekologi di RSU DOKTER SOEDARSO,sampel diambil secara consecutive sampling. Data dianalisis denganstatistik sederhana. Hasil: Ditemukan 39 sampel yang sesuai kriteriainklusi dan eksklusi dengan karakteristik sampel ; usia dengan 42 48tahun (35.9%), pekerjaan ibu rumah tangga (87.2%), dan stadium III/a(43.6%) adalah frekuensi yang tertinggi. Jumlah trombosit yang ditemukanpaling banyak adalah trombositosis (>400.000/ul) (64.1%). Rata-rata nilaitrombosit tertinggi yang ditemukan ada di stadium IV (592.000/ul).Kesimpulan: Distribusi jumlah trombosit terbanyak adalah trombositosis.Keadaan trombositosis mulai ditemukan pada stadium III/a. Nilai trombositmeningkat secara linier dengan stadium kanker serviks

    Hydrogen spillover in tungsten oxide bronzes as observed by broadband neutron spectroscopy

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    Funding: This research was funded by the UK Science and Technology Facilities Council via direct access proposal (RB1920033, VESUVIO).Hydrogen spillover is an elusive process, and its characterization, using experimental probes and ab initio modeling, poses a serious challenge. In this work, the nuclear quantum dynamics of hydrogen in a palladium-decorated cubic polymorph of tungsten oxide, Pd/cWO3, are characterized by the technique of neutron Compton scattering augmented by ab initio harmonic lattice modeling. The deeply penetrating nature of the neutron scattering process, the lack of spectroscopic selection rules, the inherent high sensitivity to hydrogen, the high energy and momentum resolution for hydrogen, and the mass selectivity of the technique render the neutron Compton scattering a very potent and unique tool for investigating the local dynamics of hydrogen species in bulk matrices. The total neutron Compton scattering response of hydrogen is described in terms of the hydrogen momentum distribution. The distribution is deconvoluted under the assumption of three pools of hydrogen with distinctly different nuclear quantum dynamical behavior: (i) hydrogen-terminated beta-palladium hydride, (ii) hydrogen in acid centers (OH+ groups) on the surface of the cubic phase of tungsten oxide, and (iii) quasi-free atomic hydrogen inside the saturated hydrogen bronze resulting from the spillover process. The ab initio modeling of lattice dynamics yields theoretical predictions for the values of the widths of proton momentum distributions in the first two hydrogen pools, which allows for obtaining the contribution and the width of the momentum distribution of the quasi-free atomic hydrogen resulting from the hydrogen spillover process. The analysis reveals that the local binding strength of the quasi-free hydrogen is characterized by the values of nuclear momentum distribution width, nuclear kinetic energy, and force constant of the underlying potential of the mean force close to those of free, unconstrained hydrogen atomic species in a gas of non-interacting particles described by the Maxwell–Boltzmann distribution. Moreover, this picture of the local dynamics of the quasi-free hydrogen is consistent with the proton polaron model of hydrogen-induced coloration of bulk hydrogenated WO3.Publisher PDFPeer reviewe
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