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Charge-transfer state and state mixing in tetracyanoquinodimethane probed using electroabsorption spectroscopy
Get PDFTetracyanoquinodimethane (TCNQ) is an important constituent of organic conductors and a versatile electron acceptor. TCNQ exhibited thermally activated delayed fluorescence and an unusually long fluorescence lifetime. In this study, we studied the Stark effect on the absorption spectrum of TCNQ using electroabsorption spectroscopy to gain insights into its photophysics. The electroabsorption spectrum was simulated using multiple absorption bands for different electronic states, which were characterized by different dipole moments and polarizabilities. These electronic states are identified as a locally excited (LE) state with a high oscillator strength and zero dipole moment, and an intramolecular charge transfer (ICT) state with a nonzero dipole moment. The mixing of the LE state with the ICT state is augmented when the molecule is perturbed by an electric field. We provide tangible experimental evidence establishing the key role of mixing between the emissive LE and nonemissive ICT states in the deactivation pathway of electronically excited TCNQ. The dipole moment of the ICT state suggests symmetry breaking of the structure belonging to the D2h point group.journal articl
Data-driven discovery of electron continuity equations in electron swarm map for determining electron transport coefficients in argon
Get PDFIn this study, we develop a novel method for determining electron
transport coefficients from electron swarm maps measured by a scanning drift-tube
experiment. In our method, two types of electron continuity equations that describe
either the spatial or the temporal evolution of an electron swarm are discovered in
the electron swarm map. The electron transport coefficients can be determined
from the coefficients in the discovered equations. Therefore, we can determine the
Townsend ionization coefficient, ionization rate coefficient, center-of-mass drift
velocity, mean arrival-time drift velocity, longitudinal diffusion coefficient, and
longitudinal third-order transport coefficient. These transport coefficients in argon
are determined over a wide range of reduced electric fields, E/N, from 29.7 to
1351.6 Td (1 Td = 10-21 Vm2) using our method. We establish that the consideration
of high-order transport coefficients, which have been systematically ignored so far,
is important for the proper determination of low-order transport coefficients,
specifically the electron drift velocity and longitudinal diffusion coefficient, in the
presence of ionization growth.journal articl
On a Descriptive Study of a Word-stress System : From a Fieldworker's Point of View
Get PDFapplication/pdfThere have been much scholarly work on word-stress systems around the world, and many theoretical issues seem to have been solved. However, several questions will still soon arise once you conduct field researches on a stress accent language: How do we verify it's accent system as word-stress system? What prosodic features does a stress accent language has to have? Is it always straightforward to elicit wordstress patterns in research interviews? Is a stress accent language which has another prosodically distinctive feature still diagnosed as a stress accent language? In the present paper, the author, who has been involved with descriptive investigation into the word-stress systems of the North Germanic languages, attempts to resolve these questions based on his experience and knowledge acquired through descriptive field researches.学術論文departmental bulletin pape
単調および繰返し載荷を受ける補強流動化処理土の力学的挙動に関する実験的研究
Get PDF室蘭工業大学Muroran Institute of Technology博士（工学）application/pdf本研究では、98ケースの圧密非排水単調・繰返し三軸試験結果に基づいて、単調および繰返し載荷による流動化処理土および補強された流動化処理土（LSS）の力学挙動について議論されている。単調載荷試験では、LSSの強度・変形特性に及ぼす泥水密度、養生日数の影響を検討するとともに、綿状に粉砕した新聞紙を0, 10 kg/m3で混合した室内および原位置養生の繊維材混合流動化処理土が比較・検討された。試験結果に基づいて、LSSの強度特性に及ぼす泥水密度の影響は、養生日数の影響よりも大きいことが明らかにされた。また、ピーク前のq～a関係の挙動は、養生日数の影響とは対照的に泥水密度の影響でより非線形的になること、LSSのせん断による損傷程度は、養生日数の増大とともに小さくなるが、泥水密度にはあまり依存しないことが明らかとなった。繰返し載荷試験では、変形特性に及ぼす繰返し載荷の影響を検討する目的で、室内で28日間養生した流動化処理土に対して、軸差応力振幅、初期応力、圧密圧力、ひずみ速度、制御方法（応力-ひずみサイクル）などを変化させるとともに、泥水密度、繊維材混合量、セメント添加量などの流動化処理土材料を変化させた．その結果、流動化処理土および繊維材で補強された流動化処理土は液状化を生じないことが明らかとなった。また、破壊モードは、繰返し軸差応力振幅と初期軸差応力に依存すること、等方応力状態から一定の軸差応力振幅で載荷した場合、間隙水圧と両振幅軸ひずみは繰返し載荷回数の増加とともに増加すること、繊維材混合流動化処理土は、かなり大きなひずみ振幅により、最終的に破壊に至ること、最終段階における有効応力履歴ループは、バタフライ形状の応力経路となることなどが明らかにされた、また、載荷中立軸の軸差応力を正の値にした繰返し載荷では、それぞれの繰返し載荷に伴って軸ひずみの蓄積が生じ、動員される両振幅軸ひずみはほとんど一定に保たれる。したがって、永久ひずみの過大な蓄積により破壊規準は満たされることになる。最終段階の応力ループの形状は、バタフライ型やレンズ型にはならず、限界状態線(CSL)を越えた後、再び戻ってくる経路となった。これは、繊維材混合流動化処理土は破壊規準線に到達する前に膨張傾向になることを意味する。応力レベルを示す繰返し応力比（CSR）の範囲は0.275～0.344であった。応力レベルがこの範囲より小さい場合、流動化処理土は蓄積される永久軸ひずみにより膨張傾向を示し破壊には至らない。流動化処理土の繰返しせん断抵抗は、初期平均有効応力と固化材量が減少すると減少し、繊維材混合量や泥水密度を増加すると増加することが明らかになった。有限要素法は地震振動解析に広く用いられているが、その結果は構成式と数値解析に適用されるモデルパラメータに大きく依存する。本研究では流動化処理土の挙動を解析するための特定のモデル、Ramberg-OsgoodモデルのDelphiコードへの実装が行われた。解析値と実験値の比較から、流動化処理土の繰返し載荷挙動の評価にRamberg-Osgoodモデルが適用可能であり、動的パラメータは適切に校正される必要があることが明らかとなった。以上より、単調および繰返し載荷を受ける補強された流動化処理土の力学的挙動に関して、多くの新たな知見が示された。In this study, the mechanical behavior of reinforced and unreinforced Liquefied Stabilized Soil (LSS) subjected to monotonic and cyclic loading is discussed based on a database with about Consolidated-Undrained monotonic and cyclic triaxial tests of 98 cases.In the monotonic tests, the influences of slurry density and curing time on the strength and deformation of LSS are investigated. Also, LSS mixed with the pulverized newspaper in the amount of 0 and 10 kg/m3 cured laboratory and in-situ are compared and investigated. Based on the test results, the effect of slurry density on the strength of LSS was found to be greater than the effect of curing time. The pre-peak behavior of the q~a curve became more non-linear under the effect of changing slurry density, in contrast to the effect of curing time. Moreover, the damage degree of LSS with shearing becomes small with curing time, while it seems to be rather independent of slurry density. With in-situ LSS, the influence of curing time on the initial Young’s modulus, E0, is lower than the effect of slurry density.In the cyclic tests, in order to investigate the effect of cyclic load on the deformation property, the deviator stress amplitude, the initial stress, consolidation pressure, strain rate, and the control method (stress vs. strain cycles) were changed and LSS material which includes slurry density, fiber material, and cement base agent on LSS cured 28 days at the laboratory have been also varied. Based on the test results, it is found that the true liquefaction (q = p = 0) did not reach reinforced and unreinforced LSS. The failure mode is highly dependent on the cyclic deviator stress amplitude (σ_d) and initial deviator stress (σ_s). For symmetrical loading (σ_(s )= 0), the pore water pressure and double amplitude axial strain grew with an increasing number of cycles. LSS mixed with fiber material finally collapsed due to too large strain amplitudes. In the final stage, the loops of effective stress indicate a “Butterfly” stress path shape. For nonsymmetrical loading (σ_(s )> 0), an accumulation of compressional axial strain with each subsequent cycle occurred, while the mobilized double amplitude axial strain remained almost constant. Therefore, the failure criterion was fulfilled due to an excessive accumulation of permanent strains. The shape of the stress loop at the final stage did not pass the “butterfly” shape or lens shape to migrate to pass over the Critical State Line (CSL), then return to the touch again of the failure envelope. It means the LSS mixed fiber material tends to dilate before reaching the failure criterion. The range of critical cyclic stress ratio (CSR), which indicates the limitation of stress level, was between 0.275 to 0.344. If the stress level is lower than that value, the LSS sample is more dilative by accumulating permanent axial strain and does not reach failure. The cyclic shear resistance of LSS decreases when reducing the initial mean effective principal stress and cement content. In contrast, the cyclic shear resistance increases when adding fiber and increasing slurry density.The Finite Element Method (FEM) is used widely in the analysis of seismic vibration. However, the results depend critically on the constitutive models used and the model parameters adopted in the numerical analyses. The implementation of a specific model to analyze the behavior of LSS mixed fiber material under cyclic loading, the Ramberg-Osgood model, in the Delphi code is performed. Based on the result of the comparison of model simulations with experimental data, the overall is able to apply the Ramberg-Osgood model to evaluate the cyclic loading behavior of LSS, and dynamic parameters should be calibrated properly. In summary, a number of new findings were presented regarding the mechanical behavior of reinforced, liquefied stabilized soils subjected to monotonic and cyclic loading.doctoral thesi
Meaning of the Progressive Form + the Perfect Form in Ainu Language
Get PDF本稿はアイヌ語の継続形式「kor an」、「wa an」と完了形式「a」が共起する場合の意味機能を記述するものである。「kor an」＋「a」は主体動作動詞と共起する場合：1、発話時まで続き、発話以後も続く可能性がある継続動作；2、最近の活動；3、個々の時間幅のある継続動作からなる習慣；4、点として捉えられる継続動作からなる習慣を表す。「kor an」＋「a」は主体変化動詞、客体変化動詞と共起する場合、限界のある過程として捉えられる。一方、「wa an」＋「a」は状態動詞、主体変化動詞、客体変化動詞と共起する場合、それぞれ「その状態が発話時点まで続いていること」、「最近の状態」、「その変化の継続結果が発話現在において鮮明に残っていること」を表す。journal articl
Cultivation Factors That Affect Amyloid-β Aggregation Inhibitory Activity in Perilla frutescens var. crispa
Get PDFAlzheimer’s disease (AD) is thought to be caused by the deposition of amyloid-β (Aβ) in the brain. Aβ begins to aggregate approximately 20 years before the expression of its symptoms. Previously, we developed a microliter-scale high-throughput screening (MSHTS) system for inhibitors against Aβ aggregation using quantum dot nanoprobes. Using this system, we also found that plants in the Lamiaceae, particularly Perilla frutescens var. crispa, have high activity. The cultivation environment has the potential to enhance Aβ aggregation inhibitory activity in plants by changing their metabolism. Here, we report on cultivation factors that affected the activity of P. frutescens var. crispa cultivated in three fields under different cultivation conditions. The results revealed that the activity of P. frutescens var. crispa harvested just before flowering was highest. Interestingly, the activity of wind-shielded plants that were cultivated to prevent exposure to wind, was reduced to 1/5th of plants just before flowering. Furthermore, activity just before flowering increased following appropriate nitrogen fertilization and at least one week of drying from the day before harvest. In addition, we confirmed that the P. frutescens var. crispa leaf extracts suppressed Aβ-induced toxicity in nerve growth factor-differentiated PC12 cells. In this study, we demonstrated that flowering, wind, soil water content, and soil nitrogen content affected Aβ aggregation inhibitory activity, necessary to suppress Aβ neurotoxicity, in P. frutescens var. crispa extracts. This study provides practical cultivation methods for P. frutescens var. crispa with high Aβ aggregation inhibitory activity for the prevention of AD.journal articl
Quasiconvexity preserving property for fully nonlinear nonlocal parabolic equations
Get PDFThis paper is concerned with a general class of fully nonlinear parabolic equations with monotone nonlocal terms. We investigate the quasiconvexity preserving property of positive, spatially coercive viscosity solutions. We prove that if the initial value is quasiconvex, the viscosity solution to the Cauchy problem stays quasiconvex in space for all time. Our proof can be regarded as a limit version of that for power convexity preservation as the exponent tends to infinity. We also present several concrete examples to show applications of our result.journal articl
Determination of the optimum biogas energy ratio in dual-fuel biodiesel used in cooking oil-biogas operation
Get PDFThis study aims to examine the effects of biogas input ratio on the engine performance, combustion characteristics, and emissions of dual-fuel mode diesel engines fueled by waste cooking oil biodiesel combined with biogas. The engine test was carried out in dual-fuel mode biodiesel-biogas operation with variations in the methane content of the biogas and biogas energy ratio in excess of 90%. The methane gas content was varied from 40%, 60%, 80%, and 100% with different applied loads. A constant engine speed of 2400 rpm is used for all tests. It has been shown that increasing the methane content of the biogas can improve the brake thermal efficiency, particularly at high loads. A maximum brake thermal efficiency of 29.3% can be achieved on dual fuel with 100% methane gas content. This value has increased by 7.51% compared to biodiesel fuel under the same load conditions. Biogas with 100% methane gas also reaches cylinder pressures of 8.07 MPa and rate of heat release of 35.8 J/deg-1 at high load operation. This study confirmed that the use of biogas with more than 90% biogas energy ratio can be operated in a dual fuel mode. At low and medium loads, nitrous oxide emissions are drastically reduced at biogas energy ratios of up to 90%, 82.8%, and 65.1%, respectively. The study also identified the optimum biogas energy ratio operating range of 60–90% for maximum thermal efficiency and low emissions.journal articl
鋳鉄の疲労強度と被削性
Get PDF室蘭工業大学Muroran Institute of Technology博士（工学）application/pdf鋳鉄は融点が低く、流動性がよく、凝固収縮が少なく、鋳造性がよいため、自動車などの機械構造体部品に幅広く使用されている．そこで、片状黒鉛鋳鉄の強度が低いため、疲労部品に不適でありますが、被削性や振動吸収能に優れるからギアケースなどの切削加工や切欠きが多い部品に使用されている。また、球状黒鉛鋳鉄は疲労強度や引張強度などに優れるが、被削性が悪いため、デフケースなど切削加工や切り欠きが少ない疲労部材に使用されています。しかし、機能性向上やコスト削減などの面から自動車用鋳造品に対する一体成形化の要求がますます高まっているため、高強度化が望まれます。そのため、本研究では、片状黒鉛鋳鉄の強度を強化し、切削及び切り欠きが必要な疲労部材に使用すること及び球状黒鉛鋳鉄の強度をさらに高強度化し、高強度部材に使用することを目的とし、Mn含有量（0.5%及び2.0%）を変化させたFC200、FC300及びFC400に相当する片状黒鉛鋳鉄及びSi含有量が異なる球状黒鉛鋳鉄FCD500相当材に疲労試験及び切削実験を行い、疲労強度及び被削性の調査を行った。疲労試験結果として、片状黒鉛鋳鉄はMn添加によりパーライト率及びA型黒鉛の増加、ラメラ層間隔の緻密化が確認され、疲労限度が最大で38%向上した。また、片状黒鉛鋳鉄の切欠き感受性におけるMnの影響は見られなかった。球状黒鉛鋳鉄は、Si含有量の増加により、黒鉛粒数の増加及び黒鉛粒径の微細化、フェライト率の増加、シリコフェライトの生成が確認され、疲労限度が最大で55%向上した。切削実験結果として、球状黒鉛鋳鉄ではSi含有量の増加に伴い切削距離の増加、切削抵抗の減少が確認された。Si含有量が最大の3.9%Si-FCD500は球状黒鉛鋳鉄の中で最も切削性に優れ、通常のFC300及びFC400（0.5%Mn）よりも良好な被削性を示した。片状黒鉛鋳鉄は2.0%Mn添加により、切削距離が増加し、切削抵抗が減少したが、FC300及びFC400の切削距離ではFC200程の影響が見られなかった。結言として、高Mn片状黒鉛鋳鉄及び高Si球状黒鉛鋳鉄が優れた機械的性質を示したため、材質が片状黒鉛鋳鉄及び球状黒鉛鋳鉄を用いて製造される自動車部品は、生産コスト及び加工コストの面で最適化することができる。例えば、形状を変えずに薄肉化や高強度部材への適用が可能である。Cast iron is widely used for machine structure parts such as automobiles because of its low melting point, low solidification shrinkage, excellent flowability, and castability. There, the low strength of flake graphite cast iron makes it unsuitable for fatigue parts, but it is used for parts with a lot of cutting and notches, such as gear cases, because of its excellent machinability and vibration absorption capacity. Spheroidal graphite cast iron has excellent fatigue strength and tensile strength, but its machinability is poor, so it is used for fatigue components with little cutting or notches, such as differential cases. However, higher strength is desired because of the ever-increasing demand for integral molding (near-net-shape) for automotive castings in terms of improved functionality and cost reduction. Therefore, in this doctoral thesis, with the aim of strengthening the strength of flake graphite cast iron for use in fatigue members requiring cutting and notching and further increasing the strength of spheroidal graphite cast iron for use in high-strength members, fatigue tests and cutting tests were conducted on FC200, FC300 and FC400 with varying Mn content and FCD500 with different Si content to investigate fatigue strength and machinability. The fatigue results reveal an increase in the pearlite fraction, an increase in the crystallization of Type-A graphite, and a decrease in the interlamellar spacing owing to the addition of Mn, which results in an increase in the fatigue limit of FGIs up to 38 %. And no effect of Mn on the notch sensitivity of FGI was observed. For SGI, an increase in Si content resulted in an increase in the graphite nodule count and a finer mean graphite nodule diameter, an increase in the ferrite fraction, and the formation of silico-ferrite, with a maximum increase in fatigue limit of 55 %. As a result of cutting tests, an increase in cutting length and a decrease in cutting force were observed in SGIs as Si content increased; the 3.9%Si-FCD500 with the highest Si content showed the best machinability among the SGIs, better than the general FC300 and FC400 (0.5% Mn). The addition of 2.0% Mn to FGIs increased cutting length and decreased cutting force, but did not have the same effect on the cutting length of FC300 and FC400 as FC200. In conclusion, high Mn FGI and high Si SGI showed excellent mechanical properties, and automotive components manufactured using FGI and SGI as materials can be optimised in terms of production and processing costs. For example, the material can be made thinner and applied to higher-strength components without changing the shape.doctoral thesi