78 research outputs found

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

    Get PDF
    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

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

    Get PDF
    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

    Effects of aging on the stress-induced martensitic transformation and cyclic superelastic properties in Co-Ni-Ga shape memory alloy single crystals under compression

    Get PDF
    Co-Ni-Ga shape memory alloys attracted scientific attention as promising candidate materials for damping applications at elevated temperatures, owing to excellent superelastic properties featuring a fully reversible stress-strain response up to temperatures as high as 500 °C. In the present work, the effect of aging treatments conducted in a wide range of aging temperatures and times, i.e. at 300–400 °C for 0.25–8.5 h, was investigated. It is shown that critical features of the martensitic transformation are strongly affected by the heat treatments. In particular, the formation of densely dispersed γ’-nanoparticles has a strong influence on the martensite variant selection and the morphology of martensite during stress-induced martensitic transformation. Relatively large, elongated particles promote irreversibility. In contrast, small spheroidal particles are associated with excellent functional stability during cyclic compression loading of 〈001〉-oriented single crystals. In addition to mechanical experiments, a detailed microstructural analysis was performed using in situ optical microscopy and neutron diffraction. Fundamental differences in microstructural evolution between various material states are documented and the relations between thermal treatment, microstructure and functional properties are explored and rationalized

    Mechanism of enhancement of ferroelectricity of croconic acid with temperature

    Get PDF
    A microscopic study of the thermal behaviour of atomic motions in the organic ferroelectric croconic acid is presented in the temperature range 5–300 K.</p

    Crystal structure of magnesium selenate heptahydrate, MgSeO4·7H2O, from neutron time-of-flight data

    Get PDF
    MgSeO4·7H2O is isostructural with the analogous sulfate, MgSO4·7H2O, consisting of isolated [Mg(H2O)6](2+) octa-hedra and [SeO4](2-) tetra-hedra, linked by O-H⋯O hydrogen bonds, with a single inter-stitial lattice water mol-ecule. As in the sulfate, the [Mg(H2O)6](2+) coordination octa-hedron is elongated along one axis due to the tetra-hedral coordination of the two apical water mol-ecules; these have Mg-O distances of ∼2.10 Å, whereas the remaining four trigonally coordinated water mol-ecules have Mg-O distances of ∼2.05 Å. The mean Se-O bond length is 1.641 Å and is in excellent agreement with other selenates. The unit-cell volume of MgSeO4·7H2O at 10 K is 4.1% larger than that of the sulfate at 2 K, although this is not uniform; the greater part of the expansion is along the a axis of the crystal

    On the impact of nanometric γ’ precipitates on the tensile deformation of superelastic Co49Ni21Ga30

    Get PDF
    Results are presented reporting on the martensite domain variant selection and stress-induced martensite morphology in [001]-oriented superelastic Co49Ni21Ga30 shape memory alloy (SMA) single crystals under tensile load. In situ neutron diffraction, as well as in situ optical- and confocal laser scanning microscopy were conducted focusing on three differently treated samples, i.e. in the as-grown, solution-annealed and aged condition. An aging treatment performed at 350 °C promotes the precipitation of nanoprecipitates. These second phase precipitates contribute to an increase of the number of habit plane interfaces, while reducing lamellar martensite plate thickness compared to the as-grown and solution-annealed (precipitate free) samples. During tensile loading, all samples show a stress-induced formation of martensite, characterized by one single domain variant (“detwinned”) and one set of parallel habit planes in a shear band. The results clearly show that γ’ nanoprecipitates do not necessarily promote multi-variant interaction during tensile loading. Thus, reduced recoverability in Co-Ni-Ga SMAs upon aging cannot be solely attributed to this kind of interaction as has been proposed in literature so far
    corecore