Numerical and Experimental Analysis of Three-Dimensional Boundary-Layer Transition Induced by Isolated Cylindrical Roughness Elements

Takahiro Ishida,Keisuke Ohira,Rio Hosoi,Naoko Tokugawa,Takahiro Tsukahara 한국항공우주학회 2022 International Journal of Aeronautical and Space Sc Vol.23 No.4

Extensive research to establish an index of roughness that causes abrupt turbulent transition downstream of the roughness and affect natural laminar flow is performed. This study investigates turbulent transitions dominated by the roughness-induced crossflow instability on a swept wing and a swept flat plate. Direct numerical simulations (DNS) are performed considering the swept wing to determine the critical roughness height that induces abrupt turbulent transition. Compared to its no-roughness counterpart, the roughness increases both the pressure drag and skin-friction drag and decreases the lift owing to the onset of upstream turbulence. The wind tunnel tests are performed considering a swept flat-plate boundary-layer model. The development of turbulent regions due to the roughness is investigated. The results reveal the occurrence of a laminar-to-turbulent transition and relaminarization, along the boundary between laminar and localized turbulent regions. Moreover, the DNS results reveal the generation of traveling crossflow vortices from the localized turbulent region.

Improving quality of common reed (Phragmites communis Trin.) silage with additives

Keigo Asano,Takahiro Ishikawa,Ayako Araie,Motohiko Ishida 아세아·태평양축산학회 2018 Animal Bioscience Vol.31 No.11

Objective: Common reed (Phragmites communis Trin.) could potentially provide an alternative resource for silage; however, its silage quality is poor. The aim of this study was to investigate the factors in reed that contribute to poor quality and determine how the use of additives at ensiling could improve fermentation quality. Methods: In Experiment 1, we determined the chemical composition and the presence of indigenous lactic acid bacteria (LAB) in reed. We further examined fermentation quality of reed silage under conditions without additives (NA) and treated glucose (G), lactic acid bacteria (L), and their combination (G+L). In Experiment 2, silage of NA, and with an addition of cellulase and lactic acid bacteria (CL) were prepared from harvested reed. The harvested reeds were fertilized at nitrogen concentrations of 0, 4, 8, and 12 g N/m2 and were harvested thrice within one year. Results: The indigenous LAB and fermentable carbohydrates are at extremely low concentrations in reed. Reed silage, to which we added G+L, provided the highest quality silage among treatments in Experiment 1. In Experiment 2, N fertilization had no negative effect on silage quality of reed. The harvest times decreased fermentable carbohydrate content in reed. The CL treatment provided a higher lactic acid content compared to the NA treatment. However, the quality of CL treated silage at the second and third harvests was significantly lower than at the first harvest, due to a reduction in carbohydrates caused by frequent harvesting. Conclusion: The causes of poor quality in reed silage are its lack of indigenous LAB and fermentable carbohydrates and its high moisture content. In addition, reed managed by frequent harvesting reduces carbohydrate content. Although the silage quality could be improved by adding CL, higher-quality silage could be prepared by adding fermentable carbohydrates, such as glucose (rather than adding cellulases).

Dosimetric advantages and clinical outcomes of simultaneous integrated boost intensity-modulated radiotherapy for anal squamous cell carcinoma

Sakanaka, Katsuyuki,Itasaka, Satoshi,Ishida, Yuichi,Fujii, Kota,Horimatsu, Takahiro,Mizowaki, Takashi,Sakai, Yoshiharu,Hiraoka, Masahiro The Korean Society for Radiation Oncology 2017 Radiation Oncology Journal Vol.35 No.4

Purpose: The purpose of this study was to explore the dosimetric difference between simultaneous integrated boost intensity-modulated radiotherapy (SIB-IMRT) and three-dimensional conformal radiotherapy (3DCRT), and the clinical outcomes of anal squamous cell carcinoma (ASCC) chemoradiotherapy featuring SIB-IMRT. Materials and Methods: This study included ten patients with ASCC who underwent chemoradiotherapy using SIB-IMRT with 5-fluorouracil and mitomycin C. SIB-IMRT delivered 54 Gy to each primary tumor plus metastatic lymph nodes and 45 Gy to regional lymph nodes, in 30 fractions. Four patients received additional boosts to the primary tumors and metastatic lymph nodes; the median total dose was 54 Gy (range, 54 to 60 Gy). We additionally created 3DCRT plans following the Radiation Therapy Oncology Group 9811 protocol to allow dosimetric comparisons with SIB-IMRT. Locoregional control, overall survival, and toxicity were calculated for the clinical outcome evaluation. Results: Compared to 3DCRT, SIB-IMRT significantly reduced doses to the external genitalia, bladder, and intestine, delivering the doses to target and elective nodal region. At a median follow-up time of 46 months, 3-year locoregional control and overall survival rates were 88.9% and 100%, respectively. Acute toxicities were treated conservatively. All patients completed radiotherapy with brief interruptions (range, 0 to 2 days). No patient experienced ${\geq}grade$ 3 late toxicity during the follow-up period. Conclusion: The dosimetric advantages of SIB-IMRT appeared to reduce the toxicity of chemoradiotherapy for ASCC achieving high locoregional control in the extended period.

Comparison of Anodic Community in Microbial Fuel Cells with Iron Oxide-Reducing Community

( Hiroshi Yokoyama ),( Mitsuyoshi Ishida ),( Takahiro Yamashita ) 한국미생물 · 생명공학회 2016 Journal of microbiology and biotechnology Vol.26 No.4

The group of Fe(III) oxide-reducing bacteria includes exoelectrogenic bacteria, and they possess similar properties of transferring electrons to extracellular insoluble-electron acceptors. The exoelectrogenic bacteria can use the anode in microbial fuel cells (MFCs) as the terminal electron acceptor in anaerobic acetate oxidation. In the present study, the anodic community was compared with the community using Fe(III) oxide (ferrihydrite) as the electron acceptor coupled with acetate oxidation. To precisely analyze the structures, the community was established by enrichment cultures using the same inoculum used for the MFCs. High-throughput sequencing of the 16S rRNA gene revealed considerable differences between the structure of the anodic communities and that of the Fe(III) oxide-reducing community. Geobacter species were predominantly detected (>46%) in the anodic communities. In contrast, Pseudomonas (70%) and Desulfosporosinus (16%) were predominant in the Fe(III) oxide-reducing community. These results demonstrated that Geobacter species are the most specialized among Fe(III)-reducing bacteria for electron transfer to the anode in MFCs. In addition, the present study indicates the presence of a novel lineage of bacteria in the genus Pseudomonas that highly prefers ferrihydrite as the terminal electron acceptor in acetate oxidation.

Sliding Mode Control based on a Modified Linear Control Input

Takehito Fujio,Hiroki Shibasaki,Ryo Tanaka,Takahiro Murakami,Yoshihisa Ishida 제어·로봇·시스템학회 2016 International Journal of Control, Automation, and Vol.14 No.1

In this study, we explain and demonstrate a design method of sliding mode control based on a modifiedlinear control input. In the proposed method, the optimal gain matrix is derived such that it does not depend onthe plant parameters. We confirmed the robustness of the proposed method by applying input-side disturbancesand plant parameter deviations to plants and the effectiveness of the proposed method by performing a DC motorposition control experiment.

Dosimetric advantages and clinical outcomes of simultaneous integrated boost intensity-modulated radiotherapy for anal squamous cell carcinoma

Katsuyuki Sakanaka,Satoshi Itasaka,Yuichi Ishida,Kota Fujii,Takahiro Horimatsu,Takashi Mizowaki,Yoshiharu Sakai,Masahiro Hiraoka 대한방사선종양학회 2017 Radiation Oncology Journal Vol.35 No.4

Purpose: The purpose of this study was to explore the dosimetric difference between simultaneous integrated boost intensitymodulated radiotherapy (SIB-IMRT) and three-dimensional conformal radiotherapy (3DCRT), and the clinical outcomes of anal squamous cell carcinoma (ASCC) chemoradiotherapy featuring SIB-IMRT. Materials and Methods: This study included ten patients with ASCC who underwent chemoradiotherapy using SIB-IMRT with 5-fluorouracil and mitomycin C. SIB-IMRT delivered 54 Gy to each primary tumor plus metastatic lymph nodes and 45 Gy to regional lymph nodes, in 30 fractions. Four patients received additional boosts to the primary tumors and metastatic lymph nodes; the median total dose was 54 Gy (range, 54 to 60 Gy). We additionally created 3DCRT plans following the Radiation Therapy Oncology Group 9811 protocol to allow dosimetric comparisons with SIB-IMRT. Locoregional control, overall survival, and toxicity were calculated for the clinical outcome evaluation. Results: Compared to 3DCRT, SIB-IMRT significantly reduced doses to the external genitalia, bladder, and intestine, delivering the doses to target and elective nodal region. At a median follow-up time of 46 months, 3-year locoregional control and overall survival rates were 88.9% and 100%, respectively. Acute toxicities were treated conservatively. All patients completed radiotherapy with brief interruptions (range, 0 to 2 days). No patient experienced ≥grade 3 late toxicity during the follow-up period. Conclusion: The dosimetric advantages of SIB-IMRT appeared to reduce the toxicity of chemoradiotherapy for ASCC achieving high locoregional control in the extended period.

New Design Approach for Sliding Mode Control of Plants with a Time Delay

Kimikazu Kawaguchi,Hiroki Shibasaki,Ryo Tanaka,Hiromitsu Ogawa,Takahiro Murakami,Yoshihisa Ishida 보안공학연구지원센터 2014 International Journal of Control and Automation Vol.7 No.5