577 research outputs found

    Simultaneous Measurements of Gas-Solid Flow Rates and Pressure Drop in Downcomer of J-Valve in CFB

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    To monitor the gas and solid streams in a downcomer of a J-valve in a CFB, the simultaneous measurement technique using the oxygen gas tracer, the hot particle tracer and the pressure drop was developed. By using this novel measurement technique, the dependence of the solid flow on the gas flow in the moving bed in the downcomer of J-valve was investigated. The pressure profile and the pressure balance in the J-valve as well as the CFB were measured. It was clarified that the circulating mass flux in a CFB or solid flow in a J-valve was governed by the pressure drop in the downcomer of the J-valve. The pressure drop in the downcomer of the J-valve was well estimated using the modified Ergun’s equation. To quantitatively control the circulating rate of the solid particles in the CFB, the monitor and tuning of the superficial gas velocity in the downcomer of the J-valve was important

    Development of Prototype Low-cost and High-strength Fault Current Interrupting Arcing Horns for 77 kV Overhead Transmission Lines

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    Fault Current Interrupting Arcing Horns (FCIAH) are newly designed arcing horns installed on transmis-sion line towers as a countermeasure against lightning damage that greatly contribute to reducing power interruption by interrupting fault current independently within an AC cycle. This paper describes the de-velopment of two new prototype FCIAH for further cost reduction and strength enhancement, using computational fluid dynamics and short-circuit tests

    Optical conductivity of rattling phonons in type-I clathrate Ba8_8Ga16_{16}Ge30_{30}

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    A series of infrared-active optical phonons have been detected in type-I clathrate Ba8_8Ga16_{16}Ge30_{30} by terahertz time-domain spectroscopy. The conductivity spectra with the lowest-lying peaks at 1.15 and 1.80 THz are identified with so-called rattling phonons, i.e., optical modes of the guest ion Ba2+(2)^{2+}(2) with T1uT_{1u} symmetry in the oversized tetrakaidecahedral cage. The temperature dependence of the spectra from these modes are totally consistent with calculations based on a one-dimensional anharmonic potential model that, with decreasing temperature, the shape becomes asymmetrically sharp associated with a softening for the weight to shift to lower frequency. These temperature dependences are determined, without any interaction effects, by the Bose-factor for optical excitations of anharmonic phonons with the nonequally spaced energy levels.Comment: 4 pages, 4 figure

    Effects of prior osteoporosis treatment on the treatment response of romosozumab followed by denosumab in patients with postmenopausal osteoporosis

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    Summary: In patients with postmenopausal osteoporosis, prior osteoporosis treatment affected the bone mineral density increase of following treatment with 12 months of romosozumab, although it did not affect that of following treatment with 12 months of denosumab after romosozumab. Purpose: To investigate the effects of prior osteoporosis treatment on the response to treatment with romosozumab (ROMO) followed by denosumab (DMAb) in patients with postmenopausal osteoporosis. Methods: In this prospective, observational, multicenter study, treatment-naïve patients (Naïve; n = 55) or patients previously treated with bisphosphonates (BP; n = 37), DMAb (DMAb; n = 45) or teriparatide (TPTD; n = 17) (mean age, 74.6 years; T-scores of the lumbar spine [LS] − 3.2 and total hip [TH] − 2.6) were switched to ROMO for 12 months, followed by DMAb for 12 months. Bone mineral density (BMD) and serum bone turnover markers were evaluated for 24 months. Results: A BMD increase was observed at 12 and 24 months in the following patients: Naïve (18.2% and 22.0%), BP (10.2% and 12.1%), DMAb (6.6% and 9.7%), and TPTD (10.8% and 15.0%) (P < 0.001 between the groups at both 12 and 24 months) in LS and Naïve (5.5% and 8.3%), BP (2.9% and 4.1%), DMAb (0.6% and 2.2%), and TPTD (4.3% and 5.4%) (P < 0.01 between the groups at 12 months and P < 0.001 at 24 months) in TH, respectively. The BMD increase in LS from 12 to 24 months was negatively associated with the levels of bone resorption marker at 24 months. Incidences of major fragility fractures for the respective groups were as follows: Naïve (5.5%), BP (16.2%), DMAb (11.1%), and TPTD (5.9%). Conclusions: Previous treatment affected the BMD increase of following treatment with ROMO, although it did not affect that of following treatment with DMAb after ROMO.This version of the article has been accepted for publication, after peer review (when applicable) and is subject to Springer Nature’s AM terms of use, but is not the Version of Record and does not reflect post-acceptance improvements, or any corrections. The Version of Record is available online at: https://doi.org/10.1007/s00198-022-06386-yEbina K., Etani Y., Tsuboi H., et al. Effects of prior osteoporosis treatment on the treatment response of romosozumab followed by denosumab in patients with postmenopausal osteoporosis. Osteoporosis International 33, 1807 (2022

    Ribonuclease Activity of Dis3 Is Required for Mitotic Progression and Provides a Possible Link between Heterochromatin and Kinetochore Function

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    BACKGROUND: Cellular RNA metabolism has a broad range of functional aspects in cell growth and division, but its role in chromosome segregation during mitosis is only poorly understood. The Dis3 ribonuclease is a key component of the RNA-processing exosome complex. Previous isolation of the dis3-54 cold-sensitive mutant of fission yeast Schizosaccharomyces pombe suggested that Dis3 is also required for correct chromosome segregation. METHODOLOGY/PRINCIPAL FINDINGS: We show here that the progression of mitosis is arrested in dis3-54, and that segregation of the chromosomes is blocked by activation of the mitotic checkpoint control. This block is dependent on the Mad2 checkpoint protein. Double mutant and inhibitor analyses revealed that Dis3 is required for correct kinetochore formation and function, and that this activity is monitored by the Mad2 checkpoint. Dis3 is a member of the highly conserved RNase II family and is known to be an essential subunit of the exosome complex. The dis3-54 mutation was found to alter the RNaseII domain of Dis3, which caused a reduction in ribonuclease activity in vitro. This was associated with loss of silencing of an ura4(+) reporter gene inserted into the outer repeats (otr) and central core (cnt and imr) regions of the centromere. On the other hand, centromeric siRNA maturation and formation of the RITS RNAi effector complex was normal in the dis3-54 mutant. Micrococcal nuclease assay also suggested the overall chromatin structure of the centromere was not affected in dis3-54 mutant. CONCLUSIONS/SIGNIFICANCE: RNase activity of Dis3, a core subunit of exosome, was found to be required for proper kinetochore formation and establishment of kinetochore-microtubule interactions. Moreover, Dis3 was suggested to contribute to kinetochore formation through an involvement in heterochromatic silencing at both outer centromeric repeats and within the central core region. This activity is likely monitored by the mitotic checkpoint, and distinct from that of RNAi-mediated heterochromatin formation directly targeting outer centromeric repeats

    Nanopowder management and control of plasma parameters in electronegative SiH4 plasmas

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    Management of nanosize powder particles via control of plasma parameters in a low-pressure SiH4 discharge for silicon microfabrication technologies is considered. The spatial profiles of electron and positive/negative ion number densities, electron temperature, and charge of the fine particles are obtained using a self-consistent fluid model of the electronegative plasmas in the parallel plate reactor geometry. The model accounts for variable powder size and number density, powder-charge distribution, local plasma nonuniformity, as well as UV photodetachment of electrons from the nanoparticles. The relations between the equilibrium discharge state and powder properties and the input power and neutral gas pressure are studied. Methods for controlling the electron temperature and SiH3- anion (here assumed to be the powder precursor) density, and hence the powder growth process, are proposed. It is shown that by controlling the neutral gas pressure, input power, and powder size and density, plasma density profiles with high levels of uniformity can be achieved. Management of powder charge distribution is also possible through control of the external parameters
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