Combustion Origin Soot Particle Aggregation with Water Steam Addition

( Yoshihiro Kobayashi ),( Taichi Shindo ),( Masataka Arai ) 한국액체미립화학회 2017 한국액체미립화학회 학술강연회 논문집 Vol.2017 No.-

Particulate matter (PM) emission from combustion engine vehicle and its reduction is strongly required. Generally, engine out PM was filtrated and oxidized by after-treatment system. Larger size PM that was completely aggregated in the exhaust line was suitable for filtration of after-treatment system. In this study, promotion of combustion origin soot aggregation was attempted. PM mainly composed of soot exhausted from a benzene laminar diffusion flame formed by a pool combustion system was used as test sample. Sample gas with PM was mixed with water steam and PM aggregation behavior during water condensation process in the mixture was investigated. Condensed water composition and dry up composition of PM were measured by filter sampling method. Size distributions of PMs before and after water steam addition were also measured by a Low Pressure Impactor. PM diameter (Dp) corresponding to a peak mass concentration was around 200nm. The level of mass concentration of PM having larger diameter than 200nm became raising with the water steam addition, but that of smaller PM was lowering with this treatment. Therefore, it was considered that PM aggregation was promoted by addition of water steam and its condensation. Moreover, in this study, soot aggregation process with water steam addition was discussed.

Different Behaviors of Catalytic Nanoparticles during Carbon Nanotube Growth by Chemical Vapor Deposition

정구환,Yoshihiro Kobayashi 한국물리학회 2009 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.54 No.3

We report different behaviors of catalytic nanoparticles during thermal chemical vapor deposition (CVD) growth of single-walled carbon nanotubes (SWNTs). We used iron and cobalt nanoparticles (NPs) as catalysts and systematically investigated their structural and compositional evolution before and after the CVD process. In the case of iron NPs, we observed particle embedment into the substrates, which caused a decrease in the apparent height on atomic force microscope measurements. The mean size of the Co NPs was also reduced due mainly to the evaporation, which was clearly measured by using X-ray photoelectron spectroscopy and secondary ion mass spectroscopy. We report different behaviors of catalytic nanoparticles during thermal chemical vapor deposition (CVD) growth of single-walled carbon nanotubes (SWNTs). We used iron and cobalt nanoparticles (NPs) as catalysts and systematically investigated their structural and compositional evolution before and after the CVD process. In the case of iron NPs, we observed particle embedment into the substrates, which caused a decrease in the apparent height on atomic force microscope measurements. The mean size of the Co NPs was also reduced due mainly to the evaporation, which was clearly measured by using X-ray photoelectron spectroscopy and secondary ion mass spectroscopy.

Perioperative Management of Patients with Hemophilia during Spinal Surgery

Kazuyoshi Kobayashi,Shiro Imagama,Kei Ando,Kenyu Ito,Mikito Tsushima,Masayoshi Morozumi,Satoshi Tanaka,Masaaki Machino,Kyotaro Ota,Yoshihiro Nishida,Naoki Ishiguro 대한척추외과학회 2018 Asian Spine Journal Vol.12 No.3

Study Design: Single-center retrospective study. Purpose: To optimize the perioperative management of patients with hemophilia who are undergoing spinal surgery. Overview of Literature: Hemophilia is a rare disease in which there is a tendency of bleeding because of a congenital deficiency in blood coagulation factor activity. There has been no previous report on spinal surgery in patients with hemophilia. Methods: The subjects were five patients (all males) with hemophilia who underwent spinal surgery at Nagoya University Hospital. Two patients had hemophilia A (deficiency of factor VIII) and three had hemophilia B (deficiency of factor IX). The mean age at the time of surgery was 63 years (range, 46–73 years). The following surgeries were performed: posterior lumbar interbody fusion (PLIF) in two patients, and lumbar fenestration, cervical laminoplasty and lumbar fenestration, and cervical laminoplasty and PLIF in one patient each. Results: Coagulation factor at a mean dose of 4.8 ×103 U (range, 3–6 ×103 U) was intravenously injected before surgery, and a mean dose of 5.2 ×103 U (rang, 4–6 ×103 U) was continuously administered for 24 hours after surgery. Factor activity was maintained at ≥80% until postoperative day 14 and at ≥50% thereafter. The average duration of surgery was 178 minutes (range, 133–233 minutes), the estimated blood loss was 661 mL (range, 272–1,344 mL), and a drain tube was left subfascially in place for 2 days in all patients. Reoperation due to postoperative surgical site infection was required in one patient, but there were no complications due to hemorrhagic diathesis. The total dose of coagulation factor administered during hospitalization was 102 ×103 U (range, 46–198 ×103 U). Conclusions: Coordination with a hematologist and dose adjustment of the coagulation factor preparation to maintain a target level of coagulation factor activity facilitated a smooth postoperative course with perioperative control of bleeding during spinal surgery for patients with hemophilia.

Large Eddy Simulation of a Liquid Metal MHD Power Generator with a SGS Model Based on the Turbulence Structure

Hiromichi Kobayashi,Hiroki Shionoya,Yoshihiro Okuno 한국전산유체공학회 2010 한국전산유체공학회 학술대회논문집 Vol.2010 No.11

Large-eddy simulation (LES) of the turbulent duct flows in the liquid metal magnethydrodynamic (MHD) power generatror is examined to reveal the behavior of the MHDI flows and the turbulent structures. The non-uniform magnetic flux density in the streamwise direction produces two eddy currents. The eddy current causes the wall-jet flows with M-shaped mean streamwise velocity profiles in the direction parallel to the external magnetic field. In contrast, the Hartmann flows with the flattened velocity profiles by the Lorentz force are produced in the direction perpendicular to the external magnetic field. In the case of the strong magnetic flux density, the turbulence structure similar to the Karman vortex sheets emerge in the downstream duct. The coherent structure model, one of the subgrid-scale models, well represents the relaminarization by the Lorentz force in comparison with the Smagorinsky model with the Van Driests wall function.

Behavior of GDI fuel spray adhered on a wall

( Kengo Jinnai ),( Yoshihiro Kobayashi ),( Masataka Arai ) 한국액체미립화학회 2017 한국액체미립화학회 학술강연회 논문집 Vol.2017 No.-

Impingement behavior of iso-octane spray injected from GDI nozzle was investigated. Ground glass plate was used as an impingement wall to observe trace-mark of liquid film on the wall. When fuel spray adhered on the ground glass plate, the light transmitted only through adhesion area of liquid fuel. This light-transmitted liquid film area was observed from bottom side of the impingement plate. The trace-mark image of liquid film was taken by high-speed camera during and after injection period. It was binarized and evaluated as the adhered area of liquid film. Adhesion area was measured under two injection pressure conditions (P_inj=0.6MPa and 3.0MPa) and two impingement distances (z= 30 mm and 50 mm) with dry wall and wet wall conditions. The total injection period was 15 ms for single shot injection. As for the split injection (10ms x 3 shots), interval of split injection was 5ms but total injected mass was kept to be same as the single injection. Fuel adhesion started when spray tip arrived at the impingement plate, its area expanded with injection elapsed however it was always narrower than the wall spray area that was observed as a general top view image of impingement spray. Further, adhesion area still increased during a few milli-seconds after injection finished. During the interval period of split injection, adhesion area was also expanded. Adhesion area on wet wall was narrower than that on dry wall because of secondary splash from wet wall. Since the continuous increase of adhesion area during the interval period was cancelled by the splash caused by following split spray, there was no apparent difference on adhesion film behaviors of single and split fuel injection. Larger increase rate of adhesion area was obtained at P_inj=3.0MPa than that at P_inj=0.6MPa, but qualitative behavior of adhesion area was not affected by the injection pressure.

Impact of Organic Acids on the Dissolution of Iron-Uranium Simulated Fuel Debris

Ryutaro Tonna,Takayuki Sasaki,Yoshihiro Okamoto,Taishi Kobayashi 한국방사성폐기물학회 2024 한국방사성폐기물학회 학술논문요약집 Vol.22 No.1

Different Behavior of Catalytic Nanoparticles during Carbon Nanotube Growth by Chemical Vapor Deposition

Goo Hwan Jeong,Yoshihiro Kobayashi 한국표면공학회 2008 한국표면공학회 학술발표회 초록집 Vol.2008 No.-

Surface Functionalization of Carbon Nanotubes Using Metal Nanoparticles for Optical Enhancement

Goo-Hwan Jeong,Yoshihiro Kobayashi 한국표면공학회 2008 한국표면공학회 학술발표회 초록집 Vol.2008 No.-

Nutritional Status Indicators Affecting the Tolerability of Postoperative Chemotherapy After Total Gastrectomy in Patients With Gastric Cancer

Toyota Kazuhiro,Mori Masayuki,Hirahara Satoshi,Yoshioka Shoko,Kubota Haruna,Yano Raita,Kobayashi Hironori,Hashimoto Yasushi,Sakashita Yoshihiro,Yokoyama Yujiro,Murakami Yoshiaki,Miyamoto Katsunari 대한위암학회 2022 Journal of gastric cancer Vol.22 No.1

Purpose: Nutritional problems after gastrectomy affect continuation of postoperative chemotherapy. There have been no studies limited to total gastrectomy, which is particularly prone to nutritional problems. In this study, we aimed to investigate the factors that predict the continuation of postoperative chemotherapy. Materials and Methods: We included 101 patients who underwent curative total gastrectomy and postoperative chemotherapy at Hiroshima Memorial Hospital. The effects of 37 factors, including perioperative inflammatory, nutritional, and tumor status, on the persistence of postoperative chemotherapy were analyzed. Results: In univariate analysis of preoperative factors, age, carbohydrate antigen 19-9, platelet-to-neutrophil ratio, Onodera's prognostic nutritional index (PNI), controlling nutritional status score, and nutritional risk screening (NRS-2002) score were significantly associated with the duration of postoperative chemotherapy. In multivariate analysis of preoperative factors, age (≥74 years) was an independent factor for a shorter duration of postoperative chemotherapy (hazard ratio [HR], 5.24; 95% confidence interval [CI], 2.19–12.96; P<0.01). In univariate analysis of factors before postoperative chemotherapy, intraoperative blood loss, perioperative weight loss rate, postoperative performance status, PNI, albumin-to-bilirubin index, and NRS-2002 score were significantly associated with the duration of postoperative chemotherapy. In multivariate analysis of factors before postoperative therapy, age (≥74 years) (HR, 5.75; 95% CI, 1.90–19.49; P<0.01) and PNI (<39) (HR, 3.29; 95% CI, 1.26–8.56; P=0.02) were independent factors for a shorter duration of postoperative chemotherapy. Conclusions: Age and PNI are useful predictors of postoperative chemotherapy intolerance after total gastrectomy and may determine the treatment strategy and timing of chemotherapy initiation.

Investigation on the electronic state of In-doped ZnO nanocrystals by hard X-ray photoemission spectroscopy

Mina Jung,Sunyeo Ha,Seungjun Oh,구지은,Keisuke Kobayashi,Tae-In Jeon,Yoshihiro Murakami,Jiho Chang,Takafumi Yao 한국물리학회 2009 Current Applied Physics Vol.9 No.2

ZnO:In nanocrystals (NCs) with various In contents were synthesized by using a mixed source vapor transportation method. The morphological variation and electronic structure of ZnO:In NCs were studied by bulk sensitive hard X-ray photoemission spectroscopy (HX-PES). ZnO:In NCs are classified into ZnOlike hexagonal and In2O3-like cubic groups, based on the crystal structure, and we have estimated the In content for the phase transformation to be as high as 35 atomic% (atm.%). A filled electronic state in the conduction band was observed from the ZnO-like group, which is regarded as a metallic state, due to an increase of extrinsic carrier density. ZnO:In nanocrystals (NCs) with various In contents were synthesized by using a mixed source vapor transportation method. The morphological variation and electronic structure of ZnO:In NCs were studied by bulk sensitive hard X-ray photoemission spectroscopy (HX-PES). ZnO:In NCs are classified into ZnOlike hexagonal and In2O3-like cubic groups, based on the crystal structure, and we have estimated the In content for the phase transformation to be as high as 35 atomic% (atm.%). A filled electronic state in the conduction band was observed from the ZnO-like group, which is regarded as a metallic state, due to an increase of extrinsic carrier density.