Utsunomiya University

About: Utsunomiya University is a education organization based out in Utsunomiya, Japan. It is known for research contribution in the topics: Laser & Holography. The organization has 4139 authors who have published 6812 publications receiving 91975 citations. The organization is also known as: Utsunomiya daigaku.

Growth regulators restore germination of Orobanche seeds that are conditioned under water stress and suboptimal temperature

Abstract: Broomrapes (Orobanche spp.) are serious root parasitic weeds that cause great damage to crop production in many parts of the world. The study focussed on the influence of plant growth regulators on germination of Orobanche seeds conditioned under suboptimal temperature (at 13 ◦ C) and under water stress (at −1 and −2 MPa). Three widely distributed species of broomrapes (O. aegyptiaca, O. ramosa, and O. minor) were used in the experiments. Exogenous GA3 (10 mg/L), brassinolide (1 mg/L), and fluridone (10 mg/L) significantly increased the broomrape seed response to the germination stimulant GR24 (10 −6 M) even when seeds were first conditioned at a suboptimal temperature and under water stress. The highest germination was obtained when the combined treatments with fluridone and brassinolide, or with GA3 and brassinolide were applied together with the germination stimulant. This indicates that there were additive effects among various plant growth regulators in the regulation of germination response in Orobanche seeds. With the prolongation of conditioning periods under low temperature stress, the restoration capacities of seed germination by a single growth regulator decreased, but the combined treatments of growth regulators retained their positive effects in restoring seed germination. Additional keywords: broomrape (Orobanche spp.), seed conditioning, plant growth regulators, temperature effect, water potential.

Robust fuel target in heavy ion inertial fusion

Abstract: Uniformity of heavy ion beam (HIB) illumination is one of the key issues in HIB inertial confinement fusion (HIF): deviation from fuel implosion symmetry should be less than a few percent in order to compress a fuel sufficiently and release fusion energy effectively. In this paper, a new mitigation method of the Rayleigh–Taylor (R-T) instability growth is presented in order to make a HIF target robust against a non-uniform implosion. In this study a new mitigation method of R-T instability growth is proposed based on an oscillating perturbed acceleration, which can be realized by a rotating or oscillating HIB illumination onto a fuel pellet. The R-T instability analyses and fluid simulations demonstrate that the oscillating acceleration reduces the R-T instability growth significantly. In this paper a baseline steady acceleration g 0 is perturbed by a perturbed oscillating acceleration δg , which is spatially non-uniform and oscillates in time ( g 0 ⪢ δg ). An example result shows 84% reduction of the R-T instability growth.

A new lensed-fiber configuration employing cascaded GI-fiber chips

Abstract: A new scheme is proposed for lensed fibers having high coupling efficiency between laser diodes and single-mode fibers with a long working distance. The new lensed fiber consists of a pair of GI-fiber tips having different focusing parameters. The measured net coupling loss between a laser diode operating at a wavelength of 1.3 /spl mu/m and a single-mode fiber is as low as 1.5 dB. The working distances are around 50 /spl mu/m, much longer than those of conventional lensed fibers.