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Accuracy and Utility of Vessel Analysis Using Non-Contrast CT for Planning Endovascular Aortic Repair

Open Journal of Medical Imaging 2024年第3期14卷 96-105页

作者： Midori Komita-Moriya yukihisa ogawa Akiyuki Kotoku Shintaro Nawata Kenji Kuramochi Yasuyoshi ogawa Kiyoshi Chiba Hiroshi Nishimaki Hidefumi Mimura Department of Radiology St. Marianna University School of Medicine Kanagawa Japan Department of Radiology Tokai University School of Medicine Hachioji Hospital Tokyo Japan Radiological Technology St. Marianna University School of Medicine Kanagawa Japan Department of Cardiovascular Surgery St. Marianna University School of Medicine Kanagawa Japan

Objectives: This study aimed to determine whether errors in vascular measurements would affect device selection in endovascular aortic repair (EVAR) by comparing measurements obtained using non-contrast computed tomography (NCT) with those obtained using contrast-enhanced CT (CECT). Materials and Methods: This single-center, retrospective study included 25 patients who underwent EVAR for abdominal aortic aneurysm at our institution. A 1-mm horizontal cross-sectional slice of NCT and CECT from each patient was retrospectively reviewed. The area from the abdominal aorta to the common iliac artery was divided into four zones. A centerline was created using the NCT by manually plotting the center points. Subsequently, the centerlines were automatically extracted and manually corrected during the arterial phase of CECT. The diameter and length of each zone were measured for each modality. The mean diameters and lengths of the target vessels were compared between NCT and CECT. Results: The measurements obtained using both methods were reproducible and demonstrated good agreement. The mean differences in vessel length and diameter measurements for each segment between NCT and CECT were not statistically significant, indicating good consistency. Conclusion: NCT may be useful for preoperative EVAR evaluation in patients with renal dysfunction or allergies to contrast agents.

关键词： Non-Contrast CT Vessel Analysis EVAR Contrast-Enhanced CT Abdominal Aortic Aneurysm

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Image Findings Following Vertebroplasty in Osteoporotic Vertebral Compression Fractures: Bone Healing and Sagittal Alignment

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Open Journal of Radiology 2013年第3期3卷 152-158页

作者： Hirotaka Ikeda Misako Nishio Shin Matsuoka Brandon D. Lohman Shoichiro Matsushita yukihisa ogawa Shingo Hamaguchi Yasuo Nakajima Atsushi Kojima Yoshiaki Torii Yutaka Sasao Department of Orthopedic Surgery St. Marianna University School of Medicine Kawasaki Japan Department of Radiology St. Marianna University School of Medicine Kawasaki Japan

Purpose: To clarify the effect of percutaneous vertebroplasty for vertebral compression fracture by assessing the changes of radiographic and CT image findings. Materials and Methods: A retrospective radiological analysis comprising 101 vertebrae of 48 patients who underwent percutaneous vertebroplasty for painful osteoporotic vertebral compression fracture was conducted. Whole spine radiographs and CT images were compared in patients preoperatively and 6 months postoperativey. Sagittal Cobb angles in three regions, sagittal vertical axis, and pelvic tilt were measured using whole spine lateral radiographs. CT findings due to the vertebral compression fracture, its healing process, and complications were evaluated. Results: On radiographs, sagittal alignment had an average gain of no more than 2.5° in each region. Sagittal vertical axis and pelvic tilt did not show significant change. Out of 68 vertebrae that demonstrated cortical disruption on preoperative CT, 37 (54%) demonstrated fusion of disrupted cortex on postoperative CT. Conclusion: No significant difference was observed between preoperative and postoperative spinal sagittal alignment on radiographs. However, CT did reveal healing process through fusion of disrupted cortex, intervertebral bridging, and increased density of cancellous bone. It is suggested that cement in the space of fracture may play a role in both mechanical stability and bone union.

关键词： Vertebroplasty Polymethylmetacrylate CT Sagittal Alignment Bone Union

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Optimal calibration scheme for map-based control of diesel engines

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Science China(Information Sciences) 2018年第7期61卷 68-81页

作者： Yui NISHIO Yutaka MURATA yukihisa YAMAYA Masato KIKUCHI Automobile R & D Center Honda R & D Co. Ltd.

Map-based control has the advantage of a simple control structure. However, in the case of a complex plant, calibrating the map is difficult. Calibration methodology using plant model is increasing in engine calibration industries. However, the models are for steady-state operation and cannot simulate at transient operation well. This study introduces the dynamic empirical model and applies the transient corrective function of an electronic control unit to simulate more realistic behavior. The optimization problem for calibrating maps of diesel engines is constructed, and the formulation of cost function and constraints is discussed. Consequently, the proposed calibration scheme can find an optimal map in satisfied ***, the optimized maps are validated using mass production diesel engines.

关键词： optimization Gaussian SQP Diesel engine calibration DoE

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Effects of Vertical Angle of Conical Punch on Stretch Flangeability of High Strength Steel

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Acta Metallurgica Sinica(English Letters) 2015年第12期28卷 1503-1509页

作者： Yasuhiro Ito Yoshiaki Nakazawa yukihisa Kuriyama Katsuyuki Suzuk Noriyuki Suzuki Nippon Steel and Sumitomo Metal Corporation The University of Tokyo

To clarify the effects of the vertical angle of a conical punch on stretch flangeability, hole expansion forming tests were conducted. Test results showed that the hole expansion ratio becomes larger as the vertical angle *** also showed that the fracture strain at the fracture location on the hole edge was constant and independent of the vertical angle. This is because the hole expansion ratio was controlled not only by the fracture strain, which is independent of the vertical angle, but also by deformation uniformity along the hole edge. From the result of numerical analyses, it was determined that deformation uniformity depends on the gradient of circumferential stress along the radius direction. When the vertical angle is sharp, the circumferential stress showed a steep decline and the deformation localization was suppressed. Consequently, the hole edge deformed more uniformly and the hole expansion ratio became larger. It is concluded that in order to improve stretch flangeability of high strength steel, it is important to uniformly deform the hole edge by applying a conical punch with a sharp vertical angle.

关键词： Formability Ductile fracture Finite element analysis Hole expansion test

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Estimations of the Maximum Tangential Velocity V_(θm) in the Vortex Core Region and also the Mean Rotational Velocity V_(oi) near the Concave Wall Surface in the Returned Flow Type Cyclone Dust Collector

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Journal of Thermal Science 2010年第6期19卷 553-560页

作者： Akira ogawa T 110-0011. Minowa 2-14-7 Taitou-Ku Tokyo Japan

There are many types of cyclone dust collectors for separating the fine solid and dust particles from gases in the various industries and also in the home used purposes. For estimating the power loss and the collection efficiency, one of the most important factors is the maximum tangential velocity V0m in the vortex core region in the cyclone body. In order to determine V0~ by the simple method, it is useful to apply the mechanical balance of the angular momentum fluxes under the assumption of ogawa combined vortex model which is composed of the quasi-forced vortex in the vortex core region and also the quasi-free vortex surrounded the vortex core region and also under the assumption of the introduction of equivalent length Heq corresponding to the cone spaces of the cyclone body and the dust bunker. On the other hand, the mean rotational velocity Voi near the concave wall surface is also estimated by the mechanical balance of angular momentum fluxes with the moment of viscous friction force. For confirming the general applications of the obtained equations, the returned flow types cyclones changed the throat diameter D3 are designed. The material of the cyclone is the transparent acrylic resin. Therefore the inner surface of the cyclone body can be regarded as smooth surface. The comparisons of the measured velocities V~ and Voi by a cylindrical Pitot tube are shown in good agreement with those of the proposed equations. The above stated results are described in detail.

关键词： Cyclone Dust Collector Maximum Tangential Velocity Mean Rotational Velocity Angular Momentum Flux Equivalent Length Surface Frictional Force ogawa Combined Vortex Model Reynolds Number.

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Effects of loading contact on electric-power generation of lead zirconate titanate piezoelectric ceramic plate

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Journal of Advanced Ceramics 2019年第4期8卷 509-518页

作者： Mitsuhiro OKAYASU Tsukasa ogawa Graduate School of Natural Science and Technology Okayama University

To better understand the generation of electric power for piezoelectric Pb Zr Ti O3(PZT)ceramic plate(?25 mm),an attempt was made to investigate experimentally and numerically electricpower generation characteristics during cyclic bending under various loading fixtures(?0–?20 mm),i.e.,different contact *** the load-contact area on the PZT ceramic leads to a nonlinear decrease in the generated *** contact area basically enhances the generated voltage,although the voltage saturates during loading when the contact area is less than?5 mm.A similar voltage is generated for?0 and?5 mm,which is attributed to strain status(ratio of compressive and tensile strain)and material failure due to different stress distribution in the PZT *** the basis of the obtained electric generation voltage,suitable loading conditions are clarified by loading with the?5 mm fixture,which generates a higher voltage and a longer lifetime of the PZT *** this approach,it is appeared that the area contact with the area ratio of 0.04(?5 mm/?20 mm)is suitable to obtain the high efficiency of the electric voltage.

关键词： piezoelectric ceramic lead zirconate titanate ceramic electric power generation

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Spin-up and Spin-Down Times of Rotational Air Flow Depended on Mean Air Velocity and Surface Roughness on Inner Surface in Cylindrical Vortex Chamber

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Journal of Thermal Science 2004年第1期13卷 46-55页

作者： Akira ogawa Hiroyuki Murakami Department of Mechanical Eng.College of Eng. Nihon UniversityT-963.TokusadaTamura-machiKooriyama-CityJapanThe Marine Self Defense Forcethe Defense AgencyJapan

The spin-up time TA in the spin-up process and spin-down time TD in the spin-down process of rotational air flow in the cylindrical vortex chamber with three kinds of the artificial surface roughness were investigated. One of the most different characteristics between the smooth and rough surface conditions was the spin-down time TD. Also the transient response of the tangential velocity on the spin-up process was analyzed numerically and this result was compared with the experimental results. The above stated results are reported here in detail.

关键词： vortex chamber spin-up time spin-down time transient response surface roughness.

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Control of Collection Efficiency for Axial Flow Cyclone Dust Collectors with Fixed Guide Vanes and with Funnel Shaped Exit Pipes

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Journal of Thermal Science 2006年第3期15卷 240-250页

作者： Akira ogawa Masaru Arakawa T-110-0011 Minowa 2-14-7Taitou-KuTokyoJapan SHINWA RULES Co. Ltd.Sanjo-ShiNiigataJapan

The experimental result of the collection efficiency of the axial flow cyclone with the fixed guide vanes is lower than that with the tangential inlet pipe to the cyclone body due to the weak angular momentum transfer given by flowing through the guide vanes. However, one of the interesting points is the control of the collection efficiency depended on the funnel shaped exit pipes. The collection efficiencies for these funnel shaped exit pipes are depended on the Froude number. Then, in this paper, the experimental results of the pressure drop and also the collection efficiency using the fly-ash particles and also the comparison of the calculated results of the collection efficiency with the experimental results are described i~ detail.

关键词： Axial flow cyclone funnel shaped exit pipe fixed guide vanes pressure drop collection efficiency,Froude number cut-Size

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Surgery for scar revision and reduction:from primary closure to flap surgery

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Burns & Trauma 2019年第1期7卷 58-65页

作者： Rei ogawa Department of Plastic Reconstructive and Aesthetic SurgeryNippon Medical School1-1-5 Sendagi Bunkyo-kuTokyo 113-8603Japan

Scars are the final result of the four processes that constitute cutaneous wound healing,namely,coagulation,inflammation,proliferation,and *** scars are produced if the wounds reach the reticular *** nature of these scars depends on the four wound healing *** the remodeling process is excessive,collagen degradation exceeds collagen synthesis and atrophic scars are *** the inflammation phase is prolonged and/or more potent for some reason,inflammatory/pathological scars such as keloids or hypertrophic scars can *** these pathological scars are located on joints or mobile regions,scar contractures can *** used with the appropriate timing and when selected on the basis of individual factors,surgical techniques can improve mature *** review paper focuses on the surgical techniques that are used to improve mature scars,burn scars,and scar *** methods include z-plasties,w-plasties,split-thickness skin grafting,full-thickness skin grafting,local flaps(including the square flap method and the propeller flap),and expanded flaps,distant flaps,regional flaps,and free flaps.

关键词： Scar Keloid Hypertrophic scar Scar contracture Surgery Z-plasty W-plasty Local flap Expander Perforator flap

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Fatigue Property of Additively Manufactured Ti-6Al-4V under Nonproportional Multiaxial Loading

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Chinese Journal of Mechanical Engineering 2021年第6期34卷 76-84页

作者： Yuya Kimura Fumio ogawa Takamoto Itoh Graduate School of Science&Engineering Ritsumeikan UniversityShiga 5258577Japan Fracture and Reliability Research Institute Graduate School of Tohoku UniversityMiyagi 9808579Japan Department of Mechani-cal Engineering Ritsumeikan UniversityShiga 5258577Japan

The low cycle fatigue strength properties of the additively manufactured Ti-6Al-4V alloy are experimentally investi-gated under proportional and nonproportional multiaxial *** fatigue tests were conducted using hollow cylinder specimens with and without heat treatments,at room temperature in *** fatigue tests were conducted:one for proportional loading and one for nonproportional *** proportional loading was represented by a push-pull strain path(PP)and the nonproportional loading by a circle strain path(Cl).The failure lives of the additively manufactured specimens were clearly reduced drastically by internal voids and ***,the sizes of the defects were measured,and the defects were found not to cause a reduction in fatigue strength above a critical *** fracture surface was observed using scanning electron microscopy to investigate the fracture mechanisms of the additively manufactured specimens under the two types of strain *** fracture patterns were recognized for each strain paths;however,both showed retention of the crack propagation,despite the presence of numerous defects,probably because of the interaction of the *** crack propagation properties of the materials with numerous defects under nonproportional multiaxial loading were clarified to increase the reliability of the additively manufactured components.

关键词： Additive manufacturing Ti-6Al-4V Low cycle fatigue Multiaxial stress Nonproportional loading Internal defect

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