Symposium / Environmental Problem of Chemicals and the Future Perspective - Ecotoxicological Risk Assessment of Pesticides in Soil -

(Yamamoto Hiroki) 경북대학교 환경과학연구소 1999 THE 6 TH INTERNATIONAL SYMPOSIUM ON ENVIRONMENTAL Vol.- No.-

Decolonial Possibilities of Transnationalism in Contemporary Zainichi Korean Art

Hiroki Yamamoto 연세대학교 영어영문학과 BK21 Plus 사업단 2019 Situations: Cultural Studies in the Asian Context Vol.12 No.1

This study discusses the works created by three contemporary zainichiKorean artists—Oh Haji, Kum Soni, and Chong Ri Ae—after the 2000s. These artists have addressed the issue of zainichi Korean identity and thehistory of zainichi Koreans. This study also deals with two exhibitionmaking projects led by young zainichi Korean and Japanese artists in the2010s: Zainichi Genzai Bijutsu and Totsuzen Me no Mae ga Hirakete. Theseexhibitions shed light on the presence of zainichi Korean art on the globalart scene. Through these case studies, this article examines the differentways in which these artists embody the notion of transnationalism intheir works and projects. By way of conclusion, this article points outthree ways that the ethos of transnationalism articulated in the practicesof zainichi Korean artists could contribute to the process of decolonizationin the context of postcolonial Japan: first, it creates a new expressionof ethnic identity by emphasizing the notion of hybridity in the placeof homogeneity; second, it challenges the nationalized narratives ofmodern history by highlighting a form of transnational historicity; third,it promotes multiethnic dialogue on postcolonial issues by forgingalternative platforms.

Industrial production of branching enzyme, and its application for producing a highly branched cyclic dextrin, Cluster Dextrin<SUP>TM</SUP>

Hiroki Takata,Iwao Kojima,Noboru Taji,Yuji Suzuki,Mikio Yamamoto 한국생물공학회 2005 한국생물공학회 학술대회 Vol.2005 No.10

Segmentation Method for Cardiac Region in CT Images Based on Active Shape Model

Hiroki Takahashi,Masafumi Komatsu,Hyoungseop Kim,Joo Kooi Tan,Seiji Ishikawa,Akiyoshi Yamamoto 제어로봇시스템학회 2010 제어로봇시스템학회 국제학술대회 논문집 Vol.2010 No.10

Recently, multi detector row computed tomography (MDCT) has been introduced into medical fields. By the development of MDCT, images with high quality are provided into medical fields. So many related image processing techniques are proposed into medical image processing fields for extraction of abnormal area. In the medical image processing field, segmentation is one of the most important problems for analyzing the abnormalities and recognition of internal structures before the operation. For this reason, many approaches are proposed for detection of abnormal area on CT images. Before detection of abnormal areas, segmentation of organs in CT images is one of the most important problems for analyzing of disease. However, poor contrast, image noises and motion artifacts make this segmentation problem difficult in particular in cardiac region. Moreover, there are still no fully automatic segmentation methods for cardiac region on CT images. In this paper, we present automatic extraction technique for detection of cardiac region. Our proposed technique combines active shape model (ASM) and genetic algorithm (GA). We apply our proposed technique to five real CT images and satisfactory segmentation results are achieved.

Heterogeneity analysis of the surface and inner matrices of chelate-treated MSWI fly ash particles employing strong acid extraction

( Hiroki Kitamura ),( Astryd Viandila Dahlan ),( Yu Tian ),( Takashi Yamamoto ),( Fumitake Takahashi ) 한국폐기물자원순환학회(구 한국폐기물학회) 2017 한국폐기물자원순환학회 심포지움 Vol.2017 No.1

Municipal solid waste incineration (MSWI) fly ash is considered as hazardous waste owing to toxic characteristics of heavy metals. In Japan, chelate treatment is mainly used to reduce their toxicity. However, the impacts of morphological and/or heterogeneous characteristics of MSWI fly ash on leaching behaviour of heavy metals are still uncertain. Therefore, this study investigated heterogeneity of the surface and inner matrices of chelate-treated MSWI fly ash particles at microscale level for fly ash characterization. Chelate-treated MSWI fly ash, which are collected from a Japanese MSWI facility plant equipped with stoker-type incinerator (incineration capacity : 250 Mg/d), were analyzed in order to investigate heterogeneity of the particle surface. Residual materials after acid extraction (Japan Leaching test 19th, JLT19) were also analyzed in order to investigate heterogeneity of inner matrices. Morphology and elemental distributions on the surfaces of MSWI fly ash particle were investigated by scanning electron microscope (SEM) and energy dispersive X-ray analyzer (EDX). One hundred chelate- treated MSWI fly ash particles and residual materials after JLT19 were analyzed, respectively. Line profile analysis was conducted on one fly ash particle surface, which is divided to 5 sections uniformly, in order to measure relative intensity of major elements. Coefficient of variation (CV value) was calculated based on obtained relative intensity in order to quantify heterogeneity of individual particles. Area analysis was also conducted in order to measure elemental concentration on particle surfaces as weight percent (wt%) and evaluate heterogeneity among fly ash particles. Elemental mapping by EDX showed that chelate-treated MSWI fly ash particles consist mainly of Al, Ca, Cl, K, Mg, Na, O, S and Si. In contrast, residual materials consist mainly of Al/Ca/Si-based matrices owing to leaching of soluble components such as KC1 and NaCl by JLT19. Calculated CV values and measured weight percent of inner matrices (Al, Ca, and Si) are shown in Figure 1. According to heterogeneity analysis, CV values of inner matrices were in the range of 0 to 1.0. However, large differences of CV values between chelate-treated MSWI fly ash and residual materials were not observed although the particle surfaces are covered by soluble components before JLT19. The A1 and Si weight percent of residual materials increased relatively in comparison with chelate-treated MSWI fly ash owing to leaching of soluble and semi-soluble components. In addition, their weight percent distributed widely after JLT19. This means that they have large heterogeneous characteristics among fly ash particles. In some case, residual materials (aluminosilicate) also had complicated structure such as skeleton. Therefore, these results showed that morphological and heterogeneous characteristics might have impacts on leaching behavior of heavy metals.

Histamine H ₃ Heteroreceptors Suppress Glutamatergic and GABAergic Synaptic Transmission in the Rat Insular Cortex

Takei, Hiroki,Yamamoto, Kiyofumi,Bae, Yong-Chul,Shirakawa, Tetsuo,Kobayashi, Masayuki Frontiers Media S.A. 2017 Frontiers in neural circuits Vol.11 No.-

<P>Histamine H<SUB>3</SUB> receptors are autoreceptors that regulate histamine release from histaminergic neuronal terminals. The cerebral cortex, including the insular cortex (IC), expresses abundant H<SUB>3</SUB> receptors; however, the functions and mechanisms of H<SUB>3</SUB> receptors remain unknown. The aim of this study was to elucidate the functional roles of H<SUB>3</SUB> in synaptic transmission in layer V of the rat IC. Unitary excitatory and inhibitory postsynaptic currents (uEPSCs and uIPSCs) were obtained through paired whole-cell patch-clamp recording in cerebrocortical slice preparations. The H<SUB>3</SUB> receptor agonist, R-α-methylhistamine (RAMH), reduced the uEPSC amplitude obtained from pyramidal cell to pyramidal cell or GABAergic interneuron connections. Similarly, RAMH reduced the uIPSC amplitude in GABAergic interneuron to pyramidal cell connections. RAMH-induced decreases in both the uEPSC and uIPSC amplitudes were accompanied by increases in the failure rate and paired-pulse ratio. JNJ 5207852 dihydrochloride or thioperamide, H<SUB>3</SUB> receptor antagonists, inhibited RAMH-induced suppression of uEPSCs and uIPSCs. Unexpectedly, thioperamide alone increased the uIPSC amplitude, suggesting that thioperamide was likely to act as an inverse agonist. Miniature EPSC or IPSC recordings support the hypothesis that the activation of H<SUB>3</SUB> receptors suppresses the release of glutamate and GABA from presynaptic terminals. The colocalization of H<SUB>3</SUB> receptors and glutamate decarboxylase or vesicular glutamate transport protein 1 in presynaptic axon terminals was confirmed through double pre-embedding microscopy, using a combination of pre-embedding immunogold and immunoperoxidase techniques. The suppressive regulation of H<SUB>3</SUB> heteroreceptors on synaptic transmission might mediate the regulation of sensory information processes, such as gustation and visceral sensation, in the IC.</P>

Comparison of pancreaticoduodenectomy and bile duct resection for middle bile duct cancer

Michiaki Unno,Hiroki Hayashi,Chang Moo Kang,Dong Wook Choi,Hiroki Yamaue,Masakazu Yamamoto 한국간담췌외과학회 2017 한국간담췌외과학회 학술대회지 Vol.2017 No.3

Pressure Evolution of the Metamagnetic Transition in UCoAl As Measured Using 59Co NMR

Hisashi Kotegawa,Hiroki Nohara,Hideki Tou,Tatsuma D. Matsuda,Etsuji Yamamoto,Yoshinori Haga,Zachary Fisk,Yoshichika Onuki,Dai Aoki,Jacques Flouquet 한국물리학회 2013 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.63 No.3

We have performed NMR measurements under pressure in UCoAl with a quantum critical endpointof the metamagnetic transition from the paramagnetic phase to the ferromagnetic (FM) phase. 59Co-NMR sensitively detects the evolution of the internal field caused by applying the externalfield. The metamagnetic field Hm increases with increasing pressure consistently with other experimentalmethods, accompanied by the suppression of the magnetization in the field-induced FMphase and the magnetization jump at Hm. The loss of the NMR signal on approaching the QCEPindicates the development of the spin fluctuations.

Preliminary observations of surface morphology of municipal solid waste incineration fly ash particles treated by sodium carbonate, sulfate, and phosphate

( Yu Tian ),( Hiroki Kitamura ),( Astryd Viandila Dahlan ),( Takashi Yamamoto ),( Fumitake Takahashi ) 한국폐기물자원순환학회(구 한국폐기물학회) 2017 한국폐기물자원순환학회 심포지움 Vol.2017 No.1

Municipal solid wastes incineration (MSWI) is a commonly accepted solution in Japan for waste management by municipalities. The main products after incineration are bottom ash (BA) and fly ash (FA). The fly ash is cargorized as hazardous waste owing to high contents of heavy metals and toxic organic compounds like dioxin. It is necessary to take some immobilization treatment before landfill disposal of fly ash. The major treatment method in Japan is organic treatments such as chelating treatment. In this process, the authors found secondary mineral formations on fly ash surfaces. Because chelate reagents for organic treatment can be decomposed within several years and cause high concentraions of organic carbon in landfill leachate, this research focuses on inorganic treatments for stable immobilize of toxic elements. In this study, MSWI fly ash sample was collected from a Japanese MSWI facility plant. Materials used in this research are chelate-treated MSWI fly ash, and three kinds of inorganic reagents. They are sodium carbonate (0.01mol/L), sodium phosphate (0.01mol/L) and sodium sulfate (0.01mol/L). In organic treatment, sodium solutions were mixed with fly ash at the solid to liquid (L/S) ratio of 1. Moistened samples were dried at room temperature about 20 °C for about 5 days. X-Ray Diffraction (XRD) method was used to detect major secodaiy minerals. Scanning Electron Microscope (SEM) was used to observe the surface morphology of fly ash particles and Energy Dispersive X-Ray analyzer (EDX) equipped with SEM was used to measure elemental distribtuions of fly ash particle surfaces. According to the experiment results of XRD, the main crystals were sylvite, halite, anhydrite, gypsum, calcite and quartz. There is no significant difference bteween raw and inorganic-treated MSWI fly ash. It suggests that inorganic treatment did not promote secondary mineral formations which were detecable by XRD. SEM-EDX analysis showed that raw, chelate-treated and inorganic-treated MSWI fly ash particles consist mainly of Na, K, Cl, Ca, Al, and Si. According to SEM observations, significant differences of surface morphology of fly ash after inorganic treatment were not found in spite of chelate-treated MSWI fly ash. Although inomgaic treatments were expected to promote the formations of calcite (CaCO₃), gypsum (CaSO₄·2H₂O) and apatite (Ca₅(PO₄)₃(OH)₂), experimental conditions should be improved in particular water content, pH, and reaction time.

Distribution of Fluorescent Whitening Agents as an Indicator of Domestic Wastewater

Okumura, Ryouji,Yamamoto, Hiroki,Fujiwara, Manabu,Hayakawa, Kazuhide The Korean Society of Limnology 2005 생태와 환경 Vol.38 No.S

The distributions of fluorescent whitening agents (FWA) in the water of the Yasu River and their tributaries flowing into Lake Biwa (Japan) were surveyed on winter and summer. The FWA fluxes had linear correlation with the corrected resident population in catchments of the tributaries of Yasu River. Therefore, the FWAs in the rivers come from domestic wastewater, and those fluxes in the tributaries depended on the human population of their catchments. As an application of the FWA indicating domestic wastewater, we could assess seasonal changes in the sources of dissolved organic matter in the tributaries.