140 research outputs found

    Acoustic Hologram Optimisation Using Automatic Differentiation

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    Acoustic holograms are the keystone of modern acoustics. It encodes three-dimensional acoustic fields in two dimensions, and its quality determine the performance of acoustic systems. Optimisation methods that control only the phase of an acoustic wave are considered inferior to methods that control both the amplitude and phase of the wave. In this paper, we present Diff-PAT, an acoustic hologram optimisation algorithm with automatic differentiation. We demonstrate that our method achieves superior accuracy than conventional methods. The performance of Diff-PAT was evaluated by randomly generating 1000 sets of up to 32 control points for single-sided arrays and single-axis arrays. The improved acoustic hologram can be used in wide range of applications of PATs without introducing any changes to existing systems that control the PATs. In addition, we applied Diff-PAT to acoustic metamaterial and achieved an >8 dB increase in the peak noise-to-signal ratio of acoustic hologram.Comment: 25 pages, 5 figures, manuscrip

    Stereoregular poly (methyl methacrylate) with double-clickable ω-end: synthesis and click reaction

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    Isotactic and syndiotactic poly(methyl methacrylate)s with orthogonally double-clickable terminal ends, that is, α,β-unsaturated esters for Michael addition-type thiol–ene reactions and azide or alkynyl groups for azide–alkyne click reactions, were prepared via a terminating reaction of stereospecific anionic polymerization with propargyl and 2-chloroethyl α-(chloromethyl)acrylates. The subsequent polymer modification via a double click reaction proceeded quantitatively in a one-pot system under ambient conditions. The facile and almost quantitative double-end-functionalization would open a new material design based on stereoregular PMMAs with controlled molecular weights.ArticlePolymer Chemistry.6(19):3601-3607(2015)journal articl

    Synthesis and post-polymerization reaction of end-clickable stereoregular polymethacrylates via termination of stereospecific living anionic polymerization

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    Poly(methyl methacrylate)s with high stereoregularity and clickable end-groups were synthesized via terminating reactions with α-(halomethyl)acrylates in stereospecific living anionic polymerization. The terminating reaction was efficient and tolerant to the reaction conditions to such an extent that almost quantitative end-functionalization was achieved in isotactic- and syndiotactic-specific polymerization systems. The terminating reactions were also achieved in polymerizations of vinyl methacrylate and trimethylsilyl methacrylate. For the polymerization of butyl acrylate, however, the termination efficiency was limited to less than 69%. Furthermore, the quantitative end-functionalization of the incorporated C[double bond, length as m-dash]C double bond at ω-end was achieved with various thiols catalyzed by Et3N. The base-catalysed thiol–ene reaction of the stereoregular poly(vinyl methacrylate) with a ω-end C[double bond, length as m-dash]C double bond selectively proceeded to retain vinyl ester functions, and the subsequent hydrolysis afforded ω-functional stereoregular poly(methacrylic acid). A combination of the terminating agent with a protected lithium amide afforded stereoregular poly(methyl methacrylates) with orthogonally clickable α- and ω-ends.ArticlePolymer Chemistry.6(7):1078-1087(2015)journal articl

    Response of osteoblasts and osteoclasts to gravity:analysis by goldfish scales as a model of bone

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    13301甲第5596号博士(理学)金沢大学博士論文本文Ful

    Quantitative evaluation of protocorm growth and fungal colonization in Bletilla striata (Orchidaceae) reveals less-productive symbiosis with a non-native symbiotic fungus

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    Quantitative evaluation of symbiotic cells in Pecteilis radiata protocorm. (a) Symbiotic cells with hyphal coils in P. radiata protocorm. Scale bars, 50 Οm. (b) Ratio of the number of symbiotic cells at each stage in a symbiotic protocorm. Each value represents the average number of symbiotic cells in ten protocorms. The experiments were repeated six times with similar results. (PDF 959 kb

    Carbon Dioxide Emissions from Hydrogen Vehicles : Is a Hydrogen-based Society Realistic?

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    二酸化炭素の排出が地球温暖化にどの程度影響しているかは議論の余地の残るところではあるが,現時点で商用化されている水素自動車(燃料電池車)は走行時に二酸化炭素を排出しないので,地球温暖化防止に有効であると広く認識されている.しかし,水素は,工業的には天然ガスから製造されているので製造時点で二酸化炭素が排出される.そこで,水素自動車が実質的に排出する二酸化炭素量を推計し,ガソリン車,ハイブリッド車,電気自動車が排出する二酸化炭素量と比較して考察した.ここで,電気自動車については発電時の排出量であるので,各国の電力ミックスに大きく依存する.比較考察した結果,日本の場合,水素自動車と電気自動車の二酸化炭素排出量は,現時点ではほぼ同量であるが,政府が2030年に目標としている電力ミックスで考えるとむしろ電気自動車の方が少なくなることがわかった.したがって,水素ステーションなどに膨大な設備投資を行って取り扱いが難しく非常に危険な水素で走行する水素自動車の普及を推進するより,現時点でもかなり普及している電気自動車の更なる普及を促進する方が合理的である.本稿では,最後に,水素の製造や発電の際に排出される二酸化炭素の地中への貯留手法であるCCSの現状と実現性についても言及した.Hydrogen-fuel vehicles do not emit carbon dioxide while running: however, carbon dioxide is emitted during the hydrogen production process. In this study, the amount of carbon dioxide produced by hydrogen vehicles was estimated, and compared to the carbon dioxide emissions of gasoline, hybrid, electric vehicles. Although the quantity of carbon dioxide produced by electric vehicles depends on the power mix, in Japan, electric vehicle and hydrogen vehicle emissions are currently almost the same. However, by 2030, electric vehicle carbon dioxide emissions, are expected to be lower than those of hydrogen vehicles, when the power mix will reach current government targets. The government is currently promoting the use of hydrogen vehicles, but high capital investment will be required for the necessary hydrogen refueling stations. Above all, hydrogen is a very dangerous gas that can explode due to minor errors. Conversely, electric vehicles have already gained popularity and do not carry the same risks. For these reasons, it is more reasonable to promote the use of electric rather than hydrogen vehicles. Finally, this study considers the current situation and feasibility of carbon dioxide capture and storage

    Utility of syntenic relationships of VDAC1 pseudogenes for not only an understanding of the phylogenetic divergence history of rodents, but also ascertaining possible pseudogene candidates as genuine pseudogenes

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    Rodent and human genomes were screened to identify pseudogenes of the type 1 voltage-dependent anion channel (VDAC1) in mitochondria. In addition to the 16 pseudogenes of rat VDAC1 identified in our recent study, 15 and 13 sequences were identified as pseudogenes of VDAC1 in mouse and human genome, respectively; and 4, 2, and 1 sequences, showing lower similarities with the VDAC1 sequence, were identified as “possible pseudogene candidates” in rat, mouse, and human, respectively. No syntenic combination was observed between rodent and human pseudogenes, but 2 and 1 possible pseudogene candidates of VDAC1 of rat and mouse, respectively, were found to have syntenic counterparts in mouse and rat genome, respectively; and these syntenic counterparts were genuine VDAC1 pseudogenes. Therefore, syntenic combinations of pseudogenes of VDAC1 were useful not only for a better understanding of the phylogenetic divergence history of rodents but also for ascertaining possible pseudogene candidates as genuine pseudogenes
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