http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
Shigeru Matsuo,Toshiaki Setoguchi,Junji Nagao,Miah Md. Ashraful Alam,김희동 대한기계학회 2011 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.25 No.10
In recent studies on two-dimensional supersonic jets, it is reported that the hysteresis phenomenon for the reflection type of shock waves in the jet flow field is occurred under the quasi-steady flow condition and this phenomenon is affected by the transitional pressure ratio between the regular reflection and Mach reflection. However, so far, there are few researches on the hysteresis phenomenon for the transition of shock waves between regular and Mach reflection in over-expanded supersonic jets and the phenomenon has not been investigated satisfactorily. Therefore, the purpose of this study is to clarify the hysteresis phenomena for the reflection type of shock wave in the over-expanded axi-symmetric supersonic jet experimentally, and to discuss the relationship between hysteresis phenomenon and rate of the change of pressure ratio with time. Furthermore, the effect of Mach number at the nozzle exit on hysteresis loop was investigated for two kinds of nozzle.
Control of the Asymmetric Flow in a Supersonic Nozzle
Shigeru Matsuo,Toshiaki Setoguchi,Tokitada Hashimoto,Seiya Tokuda,Junji Nagao,Heuy-Dong Kim(김희동) 한국가시화정보학회 2011 한국가시화정보학회지 Vol.9 No.2
Several previous works on rocket nozzle flows have revealed thc existencc of the transition from FSS to RSS and the occurrence of asymmetric flow associated with the boundary layer separation, which can cause excessive side-loads of the propulsion system. Thus, it is of practical importance to investigate the asymmetric flow behaviors of the propulsion nozzlc and to develop its control method. In the present study, the asymmetric flow control method using a cavity system was applied to supersonic nozzle flow. Time-dependent asymmetric flow was experimcntally investigated with the rate of change of the nozzle pressure ratio. The results obtained showed that the cavity systcm installed on nozzle wall would be helpful in fixing the unsteady motions of the boundary layer separation, consequcntly reducing the possibility of the occurrence of the asymmetric flow.
Unruptured Paraclinoid Carotid Aneurysms Occur More Frequently in Younger Ages
Shigeru Miyachi,Reo Kawaguchi,Tomotaka Ohshima,Naoki Matsuo 대한신경중재치료의학회 2021 Neurointervention Vol.16 No.2
Purpose We investigated the age distribution of cerebral saccular aneurysms in various locations to clarify the differences by location and discuss the mechanism of formation. Materials and Methods We retrospectively assessed clinical material obtained from 1,252 unruptured aneurysms treated with endovascular embolization between 2004 and 2019. Age, sex, laterality, and size were investigated by the location of aneurysms, classified as cavernous internal carotid artery (ICA), paraclinoid ICA, supraclinoid ICA, anterior communicating artery, anterior cerebral artery, middle cerebral artery, basilar artery complex, and posterior inferior cerebellar artery. Paraclinoid aneurysms were subclassified into 3 patterns according to their projecting direction: S-type, with superior protrusion; M-type, with medial protrusion; and P-type, with posteroinferior protrusion. Results There was no significant difference by location for sex, laterality, and size. The mean age of patients with paraclinoid aneurysms (56.5 years old) was significantly lower than that of other aneurysm patients (64.3 years old). Notably, 40% of the patients with M-type aneurysms were <50 years old. This percentage was significantly higher than that of aneurysms at other locations (P<0.05). Conclusion We found a young female predominance for patients with paraclinoid carotid aneurysms. This study may suggest that congenital factors contribute to paraclinoid aneurysm formation as well acquired factors, such as hemodynamic stress, atherosclerotic wall damage, and local inflammation.
Examination of 93 cases of perianal warts and suggestion of a new classification
Unotoro Jo,Matsuo Keigo,Arai Takehiro,Okada Shigeru,Kawanishi Teruki,Ikegami Ryoichi,Mori Shuzo,Matsuno Hiroshi 대한대장항문학회 2023 Annals of Coloproctolgy Vol.39 No.3
Purpose: The anatomical distribution of perianal warts is associated with patient characteristics such as sexual orientation. The purpose of this study is to confirm this experiential knowledge using a quantitative classification system and analysis and to obtain findings useful for future treatment. Methods: From January 2014 to December 2020, 93 patients with perianal warts presented to our hospital. Patients were analyzed for age, sex, lesion site, and recurrence type, among other factors. The lesion site was divided into skin (S) and anal epithelium (anoderm, A), and the number and degree of each were classified into grades 0 to 3. The higher grade between S and A determines its dominant type, such as type S (e.g., S3A1) and type A (e.g., S0A2). Results: The average age of the patients was 39.6 years, and the percentage of patients who were not married was 54.8%. In all, 95.8% of patients were positive for low-risk human papillomavirus (HPV). Type S accounted for 80.6%, whereas type A accounted for 9.7%. Type A cases were all male and were all presumed to be men who have sex with men (MSM). This indicates that the determination of type A may be highly specific for MSM. The type at the time of recurrence was the same type at the time of the first surgery in almost all cases. Conclusion: In cases of perianal warts, it is useful to analyze the lesion by considering the range and grade separately for daily clinical practice on proctologist.
A System Concept for EFD/CFD Integration
Shigeya Watanabe,Shigeru Kuchi-ishi,Hiroyuki Kato,Takeshi Aoyama,Keiichi Murakami,Atsushi Hashimoto,Naoyuki Fujita,Yuichi Matsuo 한국항공우주학회 2008 한국항공우주학회 학술발표회 논문집 Vol.- No.-
A trail towards integration of EFD (Experimental Fluid Dynamics) and CFD (Computational Fluid Dynamics), that is. the development of a system called Digital/Analog Hybrid Wind Tunnel, is introduced. The aim of the system is to improve efficiency, accuracy, and reliability of aerodynamic characteristics evaluation in aerospace vehicle developments through mutual support between EFD and CFD. The function of the system consists of optimization of test planning utilizing pretest CFD calculations, an accurate correction of the wind tunnel wall and support interaction effects through CFD, CFD data refinement based on EFD data, the most probable aerodynamic characteristics estimation based on both EFD and CFD data, database including EFD and CFD data at an identical condition, and so forth. Key technical challenges in the system development, such as an automatic grid generation and high-speed solver development for CFD, a highly efficient data reduction technique for image measurement data. and techniques integrating EFD and CFD. are addressed.
Mitsushige, Yusuke,Yamaguchi, Shigeru,Lee, Byung Sun,Sung, Young Mo,Kuhri, Susanne,Schierl, Christoph A.,Guldi, Dirk M.,Kim, Dongho,Matsuo, Yutaka American Chemical Society 2012 JOURNAL OF THE AMERICAN CHEMICAL SOCIETY - Vol.134 No.40
<P>Two types of thieno-bridged porphyrins were synthesized by incorporating a thiophene group across their meso and β positions with different directions of the thiophene ring to investigate the aromaticity of these porphyrins with extended π-systems. The 2,3-thieno-bridged porphyrin showed a larger antiaromatic contribution than did the 3,4-thieno-bridged porphyrin. In the former, the antiaromatic contribution is based on a 20-π-electron conjugated circuit. The two thieno-bridged porphyrins were characterized by calculations of nucleus-independent chemical shift and anisotropy of the induced current density as well as by X-ray crystallography, NMR spectroscopy, UV–vis–NIR absorption spectroscopy, electrochemical studies, time-resolved excited-state analysis, and two-photon absorption cross section measurements. Chemical derivatization of the 2,3-thieno-bridged porphyrin was also demonstrated.</P><P><B>Graphic Abstract</B> <IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/jacsat/2012/jacsat.2012.134.issue-40/ja3082999/production/images/medium/ja-2012-082999_0006.gif'></P><P><A href='http://pubs.acs.org/doi/suppl/10.1021/ja3082999'>ACS Electronic Supporting Info</A></P>
Ioku Tetsuya,Ohshima Tomotaka,Yokota Mao,Matsuo Naoki,Miyachi Shigeru 대한신경중재치료의학회 2023 Neurointervention Vol.18 No.3
Transarterial embolization using Onyx is a well-established treatment for dural arteriovenous fistulas (DAVFs). However, complications can arise when Onyx migrates into the venous side, impairing the draining veins. We encountered a case where Onyx, injected through the arterial side, strayed into the jugular vein, forming a hairball-like structure. Our study aimed to investigate the underlying mechanism of this unusual phenomenon. We postulated that Onyx precipitates into thread-like shapes when passing through extremely narrow openings. To test this, we extruded Onyx from a syringe through a 27-gauge needle into a silicone tube with flowing water. By varying the flow speed, we observed the hardening behavior of Onyx. Under slow flow, the extruded Onyx quickly solidified at the needle tip, forming a round mass. Conversely, high-speed flow resulted in Onyx being dispersed as small pieces. We successfully replicated the formation of “Onyx threads” under continuous slow flow conditions, similar to our case. This phenomenon occurs when Onyx unexpectedly migrates to the draining vein through a tiny opening during transarterial embolization for arteriovenous shunt diseases. Early recognition and appropriate measures are necessary to prevent occlusive complications in the draining veins and the pulmonary system.