TIME VARIATIONS OF THE RADIAL VELOCITY OF H2O MASERS IN THE SEMI-REGULAR VARIABLE R CRT

Hiroshi Sudou,Motoki Shiga,Toshihiro Omodaka,Chihiro Nakai,Kazuki Ueda,Hiroshi Takaba 한국천문학회 2017 Journal of The Korean Astronomical Society Vol.50 No.6

H$_2$O maser emission {at 22 GHz} in the circumstellar envelope is one of the good tracers of detailed physics and inematics in the mass loss process of asymptotic giant branch stars. Long-term monitoring of an H$_2$O maser spectrum with high time resolution enables us to clarify acceleration processes of the expanding shell in the stellar atmosphere. We monitored the H$_2$O maser emission of the semi-regular variable R Crt with the Kagoshima 6-m telescope, and obtained a large data set of over 180 maser spectra over a period of 1.3 years with an observational span of a few days. Using an automatic peak detection method based on least-squares fitting, we exhaustively detected peaks as significant velocity components with the radial velocity on a 0.1 km s$^{-1}$ scale. This analysis result shows that the radial velocity of red-shifted and blue-shifted components exhibits a change between acceleration and deceleration on the time scale of a few hundred days. These velocity variations are likely to correlate with intensity variations, in particular during flaring state of H$_2$O masers. It seems reasonable to consider that the velocity variation of the maser source is caused by shock propagation in the envelope due to stellar pulsation.However, it is difficult to explain the relationship between the velocity variation and the intensity variation only from shock propagation effects. We found that a time delay of the integrated maser intensity with respect to the optical light curve is about 150 days.

THE TREATMENT OF DIOXINS AND PCBS IN POLLUTED SOLIDS

( Dai Kojima ),( Hiroshi Nakai ),( Tetsuo Kobayashi ),( Kenichi Ushikoshi ),( Masahiro Ogura ),( Shoaki Ide ),( Takao Kawai ) 한국폐기물자원순환학회 2002 APLAS Vol.2002 No.1

A bench-scale test had confirmed that dioxins in the coagulation sludge discharged from the leachate treatment plant in the landfill site where mainly incineration residue is dumped could be decomposed with the thermal dechlorination process (Hagenmaier method) from 380 to 0.0031 pg-TEQ/g, or by more than 99.999%. Soil contaminated with dioxins caused by exhaust gas from an incineration plant was tested with the same process. It was also confirmed that dioxins in the polluted soil could be decomposed from 6,800 to 47 pg-TEQ/g, or more than 99%. Based on the decomposing conditions obtained from these tests, the combined decomposition process of the Hagenmaier method and sodium particle dispersion process (SP process) was examined with a full-scale demonstration test to decontaminate soils polluted with PCBs. With the Hagenmaier method first, PCBs were decomposed from 26 mg/kg to less than 0.0038 mg/kg, and dioxins from 130 to less than 0.22 pg-TEQ/g. The trace contaminant contained in mist included in the gas exhausted from the thermal dechlorination equipment was then absorbed with gas cleaning oil in the gas cleaning unit. The PCBs and dioxins in this contaminated oil were decomposed with the sodium particle dispersion process respectively to 0.056 mg/kg and 0.22 pg-TEQ/mg from 9.8 mg/kg and 1.7 pg- TEQ/g. This combined system was confirmed to have as high decomposability for decomposition of PCBs in contaminated soil as more than 99.9%, and dioxins as 99.3%.

오염된 고형물에서의 다이옥신과 PCB의 처리

( Dai Kojima ),( Hiroshi Nakai ),( Tetsuo Kobayashi ),( Kenichi Ushikoshi ),( Masahiro Ogura ),( Shoaki Ide ),( Takao Kawai ) 한국폐기물자원순환학회 2002 APLAS Vol.2002 No.2

대부분 소각잔류물이 매립된 매립지 침출수 처리시설부터 배출된 응집슬러지의 다이옥신은 열적 탈염소 과정(Hagenmaier method)에 의해서 다이옥신 농도가 380pg-TEQ/g에서 0.0031 pg- TEQ/g로 99.999%이상 분해되는 것을 bench-scale 실험을 통해서 확인되었다. 소각시설에서 배출된 배가스에 의해 다이옥신이 오염된 토양은 같은 공정으로 실험이 실시되었다. 이것 또한 6,800pg-TEQ/g에서 47pg-TEQ/g로 99% 이상 분해되는 것을 알 수 있었다. 이러한 실험을 통해 얻어진 분해상태를 기초를 하여, Hagenmaier method의 분해공정과 sodium particle 분산공정 (SP process) 의 조합은 PCBs로 오염된 토양을 제거하기 위해 full-scale 입증 실험을 실시하였다. 우선, Hagenmaier method를 통해서, PCBs 물질들은 26 mg/kg에서 0.0038 mg/kg로 다이옥신은 130pg - TEQ/g에서 0.22 pg-TEQ/g로 분해되어졌다. 열적 탈염화장치로부터 발생한 배가스 mist에 포함된 미량오염 물질은 가스 방지시설공정에 cleaning oil에 흡착되었다. 오염된 oil에 존재하는 PCBs와 다이옥신류는 SP 공정을 통해 각각 PCBs의 경우 9.8 mg/kg에서 0.056 mg/kg로, 다이옥신류의 경우 1.7 pg-TEQ/g에서 0.22 pg- TEQ/mg로 분해되었다. 이런 조합된 시스템은 오염된 토양에서의 PCBs의 경우 99.9%이상 다이옥신은 99.3%이상의 높은 분해능을 확인할 수 있었다. A bench-scale test had confirmed that dioxins in the coagulation sludge discharged from the leachate treatment plant in the landfill site where mainly incineration residue is dumped could be decomposed with the thermal dechlorination process (Hagenmaier method) from 380 to 0.0031 pg-TEQ/g, or by more than 99.999%. Soil contaminated with dioxins caused by exhaust gas from an incineration plant was tested with the same process. It was also confirmed that dioxins in the polluted soil could be decomposed from 6,800 to 47 pg-TEQ/g, or more than 99%. Based on the decomposing conditions obtained from these tests, the combined decomposition process of the Hagenmaier method and sodium particle dispersion process (SP process) was examined with a full-scale demonstration test to decontaminate soils polluted with PCBs. With the Hagenmaier method first, PCBs were decomposed from 26 mg/kg to less than 0.0038 mg/kg, and dioxins from 130 to less than 0.22 pg-TEQ/g. The trace contaminant contained in mist included in the gas exhausted from the thermal dechlorination equipment was then absorbed with gas cleaning oil in the gas cleaning unit. The PCBs and dioxins in this contaminated oil were decomposed with the sodium particle dispersion process respectively to 0.056 mg/kg and 0.22 pg-TEQ/g from 9.8 mg/kg and 1.7 pg-TEQ/g. This combined system was confirmed to have as high decomposability for decomposition of PCBs in contaminated soil as more than 99.9%, and dioxins as 99.3%.

Difference in Methylmercury Exposure to Fetus and Breast-feeding Offspring: A Mini-Review

Sakamoto Mineshi,Murata Katsuyuki,Nakai Kunihiko,Satoh Hiroshi Korean Society of Environmental Health 2005 한국환경보건학회지 Vol.31 No.3

The purpose of this paper was to concisely review the practical changes in MeHg concentrations in fetus and offspring throughout gestation and suckling from our recent animal and human studies. In the animal study, adult female rats were given a diet containing 5ug/g Hg (as MeHg) for 8 weeks. Then they were mated and subsequently given the same diet throughout gestation and suckling. On embryonic days 18, 20, 22 and at parturition, the concentrations of Hg in the brains of fetus were approximately 1.5-2.0 times higher than those in the mothers. However, during the suckling period Hg concentrations in the brain rapidly declined to about 1/10 of that during late pregnancy. Hg concentrations in blood also decreased rapidly after birth. In human study, Hg concentrations in red blood cells (RBC-Hg) in 16 pairs of maternal and umbilical cord blood samples were compared at birth and 3 months of age after parturition. RBC-Hg in the umbilical cords was about 1.6 times higher than those in the mothers at parturition. However, all the infants showed declines in Hg concentrations throughout the breast-feeding period. RBC-Hg at 3 months of age was about half that at birth. Both the animal and human studies indicated that MeHg exposure to the fetus might be especially high but it dramatically decreases during the suckling period. Therefore, close attention should be paid to the gestation rather than the breast-feeding period to avoid the risk of MeHg to human infants.

On the Design of the Active Low Pass Filter Using Double Layer Uniformly Distributed RC Line

Shiro Sudo,Munetaka Koide,Hiroshi Nakai,Yasoji Suzuki,Mitsuo Teramoto 대한전자공학회 1995 JTC-CSCC : Joint Technical Conference on Circuits Vol.- No.-

Aquaculture practice for new high-quality Pacific oysters in Tohoku region of Japan after the 2011 tsunami

Takashi Kamiyama,Hiroyuki Yamauchi,Hiroshi Nakaie,Ryuichi Miwa,Yuko Murata 한국수산해양기술학회(구 한국어업기술학회) 2018 한국수산해양기술학회 학술발표대회 Vol.2018 No.11

Antireflux Metal Stent as a First-Line Metal Stent for Distal Malignant Biliary Obstruction: A Pilot Study

( Tsuyoshi Hamada ),( Hiroyuki Isayama ),( Yousuke Nakai ),( Osamu Togawa ),( Naminatsu Takahara ),( Rie Uchino ),( Suguru Mizuno ),( Dai Mohri ),( Hiroshi Yagioka ),( Hirofumi Kogure ),( Saburo Matsu 대한소화기학회 2017 Gut and Liver Vol.11 No.1

Background/Aims: In distal malignant biliary obstruction, an antireflux metal stent (ARMS) with a funnel-shaped valve is effective as a reintervention for metal stent occlusion caused by reflux. This study sought to evaluate the feasibility of this ARMS as a first-line metal stent. Methods: Patients with nonresectable distal malignant biliary obstruction were identified between April and December 2014 at three Japanese tertiary centers. We retrospectively evaluated recurrent biliary obstruction and adverse events after ARMS placement. Results: In total, 20 consecutive patients were included. The most common cause of biliary obstruction was pancreatic cancer (75%). Overall, recurrent biliary obstruction was observed in seven patients (35%), with a median time to recurrent biliary obstruction of 246 days (range, 11 to 246 days). Stent occlusion occurred in five patients (25%), the causes of which were sludge and food impaction in three and two patients, respectively. Stent migration occurred in two patients (10%). The rate of adverse events associated with ARMS was 25%: pancreatitis occurred in three patients, cholecystitis in one and liver abscess in one. No patients experienced nonocclusion cholangitis. Conclusions: The ARMS as a first-line biliary drainage procedure was feasible. Because the ARMS did not fully prevent stent dysfunction due to reflux, further investigation is warranted. (Gut Liver 2017;11:142-148)

A Novel Partially Covered Self-Expandable Metallic Stent with Proximal Flare in Patients with Malignant Gastric Outlet Obstruction

( Naminatsu Takahara ),( Hiroyuki Isayama ),( Yousuke Nakai ),( Shuntaro Yoshida ),( Tomotaka Saito ),( Suguru Mizuno ),( Hiroshi Yagioka ),( Hirofumi Kogure ),( Osamu Togawa ),( Saburo Matsubara ),( 대한간학회 2017 Gut and Liver Vol.11 No.4

Background/Aims: Endoscopic placement of self-expandable metal stents (SEMSs) has emerged as a palliative treatment for malignant gastric outlet obstruction (GOO). Although covered SEMSs can prevent tumor ingrowth, frequent migration of covered SEMSs may offset their advantages in preventing tumor ingrowth. Methods: We conducted this multicenter, single-arm, retrospective study at six tertiary referral centers to evaluate the safety and efficacy of a partially covered SEMS with an uncovered large-bore flare at the proximal end as an antimigration system in 41 patients with symptomatic malignant GOO. The primary outcome was clinical success, and the secondary outcomes were technical success, stent dysfunction, adverse events, and survival after stent placement. Results: The technical and clinical success rates were 100% and 95%, respectively. Stent dysfunctions occurred in 17 patients (41%), including stent migration in nine (23%), tumor ingrowth in one (2%), and tumor overgrowth in four (10%). Two patients (5%) developed adverse events: one pancreatitis and one perforation. No procedurerelated death was observed. Conclusions: A novel partially covered SEMS with a large-bore flare proximal end was safe and effective for malignant GOO but failed to prevent stent migration. Further research is warranted to develop a covered SEMS with an optimal antimigration system. (Gut Liver 2017;11:481-488)