24 research outputs found

    Effect of the span length of Granier-type thermal dissipation probes on sap flux density measurements

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    ‱ Granier-type thermal dissipation sensors measure sap flux density (u) by using the temperature difference between the heater and the reference probe. To detect u correctly, heat must not be transferred to the reference probe by thermal conduction. The distance across which heat can be transferred by conduction is important for the span length of a sensor and spacing of a number of sensors. ‱ To validate span lengths and spacing of sensors, we used numerical simulations to calculate the potential distance across which heat can be transferred by conduction. We compared measurements with an original and a modified sensor for a Japanese red pine (Pinus densiflora) from December 2004 to May 2005. The span length of the original and the modified sensor is 15 and 4 cm, respectively. ‱ Numerical simulations showed that span length and spacing of Granier sensors should be more than 10 cm for trees in which u ceases for a few hours before the predawn period. The modified sensor underestimated u by 18–46% in winter (December–March) because its reference temperature was increased by heat transferred by conduction. The modified sensor measured u correctly in warm seasons, and only underestimated the annual amount of transpiration by 6%

    Estimation of Sobolev embedding constant on a domain dividable into bounded convex domains

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    Abstract This paper is concerned with an explicit value of the embedding constant from W 1 , q ( Ω ) W1,q(Ω)W^{1,q}(\Omega) to L p ( Ω ) Lp(Ω)L^{p}(\Omega) for a domain Ω ⊂ R N Ω⊂RN\Omega\subset\mathbb{R}^{N} ( N ∈ N N∈NN\in\mathbb{N} ), where 1 ≀ q ≀ p ≀ ∞ 1≀q≀p≀∞1\leq q\leq p\leq\infty . We previously proposed a formula for estimating the embedding constant on bounded and unbounded Lipschitz domains by estimating the norm of Stein’s extension operator. Although this formula can be applied to a domain Ω that can be divided into a finite number of Lipschitz domains, there was room for improvement in terms of accuracy. In this paper, we report that the accuracy of the embedding constant is significantly improved by restricting Ω to a domain dividable into bounded convex domains

    Estimation of Sobolev embedding constant on a domain dividable into bounded convex domains

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    Abstract This paper is concerned with an explicit value of the embedding constant from W 1 , q ( Ω ) W1,q(Ω)W^{1,q}(\Omega) to L p ( Ω ) Lp(Ω)L^{p}(\Omega) for a domain Ω ⊂ R N Ω⊂RN\Omega\subset\mathbb{R}^{N} ( N ∈ N N∈NN\in\mathbb{N} ), where 1 ≀ q ≀ p ≀ ∞ 1≀q≀p≀∞1\leq q\leq p\leq\infty . We previously proposed a formula for estimating the embedding constant on bounded and unbounded Lipschitz domains by estimating the norm of Stein’s extension operator. Although this formula can be applied to a domain Ω that can be divided into a finite number of Lipschitz domains, there was room for improvement in terms of accuracy. In this paper, we report that the accuracy of the embedding constant is significantly improved by restricting Ω to a domain dividable into bounded convex domains

    The 2018 Hokkaido Eastern Iburi earthquake (M-JMA=6.7) was triggered by a strike-slip faulting in a stepover segment: insights from the aftershock distribution and the focal mechanism solution of the main shock

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    The Hokkaido Eastern Iburi earthquake (MJMA = 6.7) occurred on September 6, 2018, in the Hokkaido corner region where the Kurile and northeastern Japan island arcs meet. We relocated aftershocks of this intraplate earthquake immediately after the main shock by using data from a permanent local seismic network and found that aftershock depths were concentrated from 20 to 40 km, which is extraordinarily deep compared with other shallow intraplate earthquakes in the inland area of Honshu and Kyushu, Japan. Further, we found that the aftershock area consists of three segments. The first segment is located in the northern part of the aftershock area, the second segment lies in the southern part, and the third segment forms a stepover between the other two segments. The hypocenter of the main shock, from which the rupture initiated, is located on the stepover segment. The centroid moment tensor solution for the main shock indicates a reverse faulting, whereas the focal mechanism solution determined by using the first-motion polarity of the P wave indicates strike-slip faulting. To explain this discrepancy qualitatively, we present a model in which the rupture started as a small strike-slip fault in the stepover segment of the aftershock area, followed by two large reverse faulting ruptures in the northern and southern segments

    High-throughput synthesis and characterization of (Ba<sub>x</sub>Sr<sub>1–x</sub>)<sub>1+y</sub>Ti<sub>1–y</sub>O<sub>3-ή</sub> and (Ba<sub>x</sub>Sr<sub>1–x</sub>)<sub>1+y</sub>Ti<sub>1–y</sub>O<sub>3–z</sub>N<sub>z</sub> perovskite thin films

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    Thin films of (BaxSr1–x)1+yTi1–y and Zr, Gd codoped (BaxSr1–x)1+yTi1–y were deposited on platinized sapphire substrates at 640 °C under constant flux of atomic oxygen or a mixture of atomic oxygen and nitrogen to synthesize perovskites of (BaxSr1–x)1+yTi1–yO3-ή (also referred to as BSTO), (BaxSr1–x)1+yTi1–yO3–zNz (also referred to as BSTON), and Zr, Gd codoped (BaxSr1–x)1+yTi1–yO3–zNz. Structural characterization was done via XRD and XPS, and electrical characterization was done via LCR (dielectric properties and tunability under DC bias) and P–E measurements. Although the levels of nitrogen incorporated within the perovskite structure appear to be very low as determined by XPS analysis, definite improvements in dielectric properties and tunability have been achieved by synthesis of the BSTON oxynitride films. For a composition of Ba0.8Sr0.2TiO3–zNz an improvement by a factor of 1.72 for tunability and 1.44 for relative permittivity has been observed between the oxide and the oxynitride. The oxynitride achieved a tunability ratio of 6.78 to 1 (close to 7:1) under an applied electrical field of 34 kV/mm. The high throughput approach allowed us to highlight a compositional shift for the material with the best dielectric properties when comparing the oxide with the oxynitride thin films. Effects of codoping the perovskite structure with Zr and Gd have also been investigated and although the tunability and dielectric constant of the thin films were not improved, some improvements in dielectric losses were observed, along with a superparaelectric state as observed by P–E hysteresis measurements
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