著者

野口 大介

出版者

長崎大学大学院工学研究科

雑誌

長崎大学大学院工学研究科研究報告 = Reports of Graduate School of Engineering, Nagasaki University (ISSN:18805574)

巻号頁・発行日

vol.52, no.99, pp.22-29, 2022-07

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EDTA (Ethylenediaminetetraacetic acid), abbreviated as H4Y with Y4- herein, is a chelating ligand that complexes a wide range of metal ions. Alkali metal ions have rather low stability constants with EDTA; however, syntheses and crystal structures of a few alkali metal-EDTA complexes have been reported. Note that the structures have diversity, i.e., they are different from that of the EDTA complexes having typically known hexadentate Y4- with the coordination numbers (CN) 6 for cations. For example, in a lithium-EDTA complex, [Li4(EDTA-4H)], Li+ have CN 4 or 5 by tridentate μ12-Y4- . Additionally, in some sodium-, potassium- and rubidium-EDTA complexes whose crystal structures are also revealed, Na+ , K+ and Rb+ have greater CN than 6 with multidentate Y4- , HY3- and H2Y2- . Nevertheless, elucidating the structures of alkali metal-EDTA complexes in solution have still difficulties. Because in solutions the structures of the EDTA complexes do not necessarily consistent with that in crystalline states.

著者

野口 大介

出版者

長崎大学大学院工学研究科

雑誌

長崎大学大学院工学研究科研究報告 = Reports of Graduate School of Engineering, Nagasaki University (ISSN:18805574)

巻号頁・発行日

vol.52, no.98, pp.86-93, 2022-01

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Methyl Orange (MO), one of the water-soluble azo dyes, is well-known as pH indicator extensively used in secondary schools and post-secondary education institutions of chemistry. Besides, azo compounds are applied widely in imaging industries including the textile, paper, printing, and food industries. In the present study, researches on the chemical structures of MO, the positions H+ attaches in MO appear to be unclear, are described historically, dealt with acid-base reaction, ammonium-azonium tautomerism in acidic aqueous solutions by means of UV-Vis spectroscopy. Furthermore, problems in the textbooks of analytical chemistry due to misunderstanding the difference between resonance theory and tautomerism are pointed out for precise learning the structures of MO and its protonated species in an aqueous solution. X-ray crystal structures of MO are shown to support teaching students of chemistry too.

出版者

長崎大学大学院工学研究科

雑誌

長崎大学大学院工学研究科研究報告 = Reports of Graduate School of Engineering, Nagasaki University (ISSN:18805574)

巻号頁・発行日

vol.52, no.99, pp.30-37, 2022-07

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Aluminum, gallium, indium, and thallium, forming trivalent cations, are r eferred to as earth metals; only Tl also has stable monovalent one. The complexes of Al, for instance, have studied to elucidate industrial use and toxic effects in materials engineering and environmental science. Here, I briefly overview the reported crystal structures of earth metal-complexes chelated by EDTA (ethylenediaminetetraacetic acid) to deepen our knowledge and apply for further research. Bibliographic survey has revealed that 6 of Al-, 14 of Ga-, 6 of In-, and 2 of Tl(III)-EDTA were reported for the crystal structures, showing that the coordination numbers of Al3+ and Ga3+ are 6, In3+ and Tl3+ are 7 in the crystal state. The denticity of EDTA anions are not only hexadentate but also pentadentate (the fourth carboxy group is uncoordinated) in six complexes. A dinuclear Al2-EDTA complex, with two Al3+ bridged by (μ-OH-)2, has a unique cis-conformation of ethylenediamine moiety; it was appeared to have few other analogues.

著者

永松 牧子 海部 貴裕 浦田 幹康 岡本 賢治 鶴田 健 松田 浩

出版者

長崎大学大学院工学研究科

雑誌

長崎大学大学院工学研究科研究報告 = Reports of Graduate School of Engineering, Nagasaki University

巻号頁・発行日

vol.49, no.93, pp.44-48, 2019-08

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In this study, in order to clarify the possibility of internal damage in concrete structures, loading tests and ultrasonic testing technique were conducted on concrete materials. In addition, the correlation between the internal dama ge condition of concrete and the ultrasonic signal was investigated. As a result, a correlation was obtained between the damage state inside the concrete and the sound pressure and velocity of ultrasonic waves. It was clarified that the damage condition inside concrete can be estimated by evaluating sound pressure and velocity. Furthermore, it's suggested that the ultrasonic testing technique could be used to detect the damage of the concrete before it appears on the surface.

著者

野口 大介

出版者

長崎大学大学院工学研究科

雑誌

長崎大学大学院工学研究科研究報告 = Reports of Graduate School of Engineering, Nagasaki University (ISSN:18805574)

巻号頁・発行日

vol.50, no.95, pp.81-84, 2020-07

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Photocatalyzed oxidation reaction of organic compound (methylene blue; MB) by using titanium(IV) oxide (TiO2) nanoparticles and wind power to stir the solution with uses a hand-made propeller was carried out. As a first, to check the degree of reaction rate, MB was added to the aqueous solution with TiO2 nanoparticles and UV (ultraviolet rays) irradiation that changes its color of MB gradually resulted in proceeding the oxidation reaction by O2 in air. After that, calibration curve was made using UV-vis spectrometer which was used to determine the concentration of MB in the solution measuring its absorbance. Then the UV condition was changed with and without UV. As a result, it was revealed that with UV condition, the reaction rates of oxidation of MB were faster than without UV. The wind condition to stir the solution was also revealed with unexpected result; i.e., “Weak-power” wind to stir the solution accelerated the reaction rather than “Middle-power” one. The reason stirring by middle-power wind couldn't accelerate the reaction so far is supposed that hand-made propeller used to stir the solution is not strong enough to convey the power under the condition.

著者

NOGUCHI Daisuke

出版者

長崎大学大学院工学研究科

雑誌

長崎大学大学院工学研究科研究報告 = Reports of Graduate School of Engineering, Nagasaki University (ISSN:18805574)

巻号頁・発行日

vol.51, no.96, pp.55-59, 2021-01

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Ultraviolet-visible (UV-Vis) reflectance spectroscopy is one of the useful tools to evaluate the coloration of materials and living things. On crab spiders, sit-and-wait foragers on flowers, body coloration has been focused in the context of camouflage and/or prey attraction. For the first time, the present study shows UV-Vis reflectance spectra of Thomisus labefactus, a crab spider inhabits East Asia, reflects UV-Vis rays almost the same strength as an Australian crab spider Thomisus spectabilis, which also has substantial amount of UV reflection, unlike European species lacking UV reflection.紫外・可視(UV-Vis)反射分光法は,材料や生物の色彩を評価する有益なツールの一つである.カニグモは花の上で獲物を待ち伏せする捕食者であり,擬態および/あるいは餌誘引における文脈で,体の色彩に焦点が当てられてきた.本研究では,東アジアに生息するカニグモ科の一種であるアズチグモThomisus labefactus では最初となるUV-Vis 反射スペクトルの測定から,紫外線反射を欠いているヨーロッパ産の種とは異なり,相当量の紫外線を反射するオーストラリア産のカニグモ科の一種Thomisus spectabilis と同程度の強さで紫外線と可視光を反射することが示される.