Color-coded visualization of microbubble clouds interacting with eddies in a spatially developing turbulent boundary layer

Three-dimensional distribution of microbubbles dispersed in a turbulent boundary layer spatially developing along a flat plate is investigated experimentally. The aim of study is to find out visually how microbubbles interact with turbulent eddies to achieve frictional drag reduction on a wall. Setting conditions of the experiments are stream Reynolds number up to 2.3 x 10(4), microbubble volume fraction inside boundary layer less than 10(-5), and microbubble Stokes number smaller than 10(-3). Stream-wise vortices in the boundary layer were visualized by flake optics, of which spacing expands with injection of microbubbles. 3-D microbubble distributions were visualized by a color-coded volumetric illumination. The result showed preferentially accumulated microbubble clouds to low-speed streaks close to viscous sublayer and to hair-pin vortices in the buffer layer, leading to reduced diffusivity of microbubbles relative to the turbulent momentum diffusivity

Spectroscopy of ¹⁷C via one-neutron knockout reaction

21st International Conference on Few-Body Problems in Physics, Chicago, IL, USA, May 18-22, 2015.A spectroscopic study of ¹⁷C was performed via the one-neutron knockout reaction of ¹⁸C on a carbon target at RIKEN-RIBF. Three unbound states at excitation energies of 2.66(2), 3.16(5), and 3.97(3) MeV (preliminary) were observed. The energies are compared with shell-model calculations and existing measurements to deduce their spin-parities. From the comparison, the states at 2.66(2) and 3.97(3) MeV are suggested to be 1/2⁻ and 3/2⁻, respectively. From its decay property, the state at 3.16(5) MeV is indicated to be 9/2⁺

Study of ¹⁹C by One-Neutron Knockout

21st International Conference on Few-Body Problems in Physics, Chicago, IL, USA, May 18-22, 2015.The spectroscopic structure of ¹⁹C, a prominent one-neutron halo nucleus, has been studied with a ²⁰C secondary beam at 290 MeV/nucleon and a carbon target. Neutron-unbound states populated by the one-neutron knockout reaction were investigated by means of the invariant mass method. The preliminary relative energy spectrum and parallel momentum distribution of the knockout residue, ¹⁹C∗, were reconstructed from the measured four momenta of the¹⁸C fragment, neutron, and beam. Three resonances were observed in the spectrum, which correspond to the states at Ex = 0.62(9), 1.42(10), and 2.89(10) MeV. The parallel momentum distributions for the 0.62-MeV and 2.89-MeV states suggest spin-parity assignments of 5/2⁺ and 1/2⁻, respectively. The 1.42-MeV state is in line with the reported 5/22⁺ state

Identification of New Neutron-Rich Isotopes in the Rare-Earth Region Produced by 345 MeV/nucleon 238^{238}U

International audienceA search for new isotopes in the neutron-rich rare-earth region has been carried out using a 345 MeV=nucleon 238U beam at the RIKEN Nishina Center RI Beam Factory. Fragments produced were analyzed and identified using the BigRIPS in-flight separator. We observed a total of 29 new neutron-rich isotopes: 153Ba, 154,155,156La, 156,157,158Ce, 156,157,158,159,160,161Pr, 162,163Nd, 164,165Pm, 166,167Sm, 169Eu, 171Gd, 173,174Tb, 175,176Dy, 177,178Ho, and 179,180Er

Oncological outcomes of a multicenter cohort treated with axitinib for metastatic renal cell carcinoma

The present study aimed to evaluate the efficacy of the real-world use of axitinib and to develop a prognostic model for stratifying patients who could derive long-term benefit from axitinib. This was a retrospective, descriptive study evaluating the efficacy of axitinib in patients with metastatic renal cell carcinoma that had been treated with 1 or 2 systemic antiangiogenic therapy regimens at 1 of 36 hospitals belonging to the Japan Urologic Oncology Group between January 2012 and February 2019. The primary outcome was overall survival (OS). Using a split-sample method, candidate variables that exhibited significant relationships with OS were chosen to create a model. The new model was validated using the rest of the cohort. In total, 485 patients were enrolled. The median OS was 34 months in the entire study population, whereas it was not reached, 27 months, and 14 months in the favorable, intermediate, and poor risk groups, respectively, according to the new risk classification model. The following 4 variables were included in the final risk model: the disease stage at diagnosis, number of metastatic sites at the start of axitinib therapy, serum albumin level, and neutrophil : lymphocyte ratio. The adjusted area under the curve values of the new model at 12, 36, and 60 months were 0.77, 0.82, and 0.82, respectively. The efficacy of axitinib in routine practice is comparable or even superior to that reported previously. The patients in the new model's favorable risk group might derive a long-term survival benefit from axitinib treatment

Structure beyond the dripline in the Boron isotopes: 16;18;20;21^{16;18;20;21}B

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Precision spectroscopy of pionic atoms and chiral symmetry in nuclei

We conduct an experimental project to make spectroscopy of deeply bound pionic atoms systematically over wide range of nuclei. We aim at studying the strong interaction in the low energy region, which has close connection to spontaneous chiral symmetry breaking and its partial restoration in nuclear matter. First experimental results show improved spectral resolution and much better statistical sensitivity than previous experiments. Present status of the experiment is reported

Spectroscopy of C-17 Above the Neutron Separation Energy

Spectroscopy of an unbound nucleus C-17 was performed using the SAMURAI spectrometer at RIBF of RIKEN. Six resonances were observed for the C-16+n system with relative energies of 0.52, 0.77, 1.36, 1.91, 2.22 and 3.20 MeV. The excitation energies (E-x) of the observed resonances were deduced, by taking into account the states of the C-16 fragments identified by coincident gamma rays, as E-x =(3.02), 1.51, (3.86), 2.65, (4.72) and 3.94MeV. The orbital angular momenta of the two observed states in C-17 at E-x =2.65 and 3.94 MeV were determined as 1 by comparing parallel momentum distributions with theoretical predictions.11Nsciescopu