http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
Heat capacity, X-ray scattering and neutron scattering studies in Rb2SeO4
Hirotake Shigematsu,Hiroyuki Mashiyama,Hitoshi Kawaji,Takeo Tojo,Tooru Atake,Yukikuni Akishige 한국물리학회 2005 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.46 No.1
The structural phase transition and behavior of the 2 3 phonon branch of Rb2SeO4 have been investigated with the use of heat capacity measurement and X-ray and neutron scattering technique. No phase transition was detected down to 2 K, both in thermal analysis and in neutron elastic scattering. However, neutron inelastic scattering showed a slight softening of the phonon excitation frequency below 100 K. Two typical trst-order-type anomalies due to the phase I - phase II transition and melting were observed at 821 K and 1233 K, respectively. The entropy change for the phase I - phase II transition was determined as 12.46 Jmol1K1.
Mizuki Shigematsu,Takaaki Udagawa,Satoru Nagase Council on Tall Building and Urban Habitat Korea 2023 International journal of high-rise buildings Vol.12 No.3
This paper presents the structural design and response control system of the JR MEGURO MARC building, a 70 meters high office building with steel structure located in Tokyo (Figure 1). In order to achieve high earthquake resistance and useable office space, this building integrates a centralized response control system with deformation amplification mechanisms and tuned viscous mass dampers on the lower floor. Moreover, buckling-restrained braces (BRB) are installed on the upper floors to increase the effectiveness of centralized response control system and to reduce damage of the main frames in the event of a major earthquake. It features an efficient centralized response control system by amplifying the deformation of the dampers without creating a soft story.
Negative Pressure Pulmonary Edema Associated with Anterior Cervical Spine Surgery
Hideki Shigematsu,Masana Yoneda,Yasuhito Tanaka 대한척추외과학회 2014 Asian Spine Journal Vol.8 No.6
We report a very rare case of negative pressure pulmonary edema (NPPE) that occurred immediately after anterior cervical discectomy and fusion (ACDF). The patient was a 25-year-old man who sustained a facet fracture–dislocation of C5 during a traffic accident. After ACDF, he developed NPPE and needed mechanical ventilation. Fortunately, he recovered fully within 24 hours. NPPE is a rare postoperative complication that may occur after cervical spine surgery. The aims of this report are to present information regarding the diagnosis and emergent treatment of NPPE, and to review the previous literature regarding this serious complication.
Natural frequencies and mode shapes of thin-walled members with shell type cross section
T. Shigematsu,T. Hara,M. Ohga 국제구조공학회 2002 Steel and Composite Structures, An International J Vol.2 No.3
An analytical procedure based on the transfer matrix method to estimate not only the natural frequencies but also vibration mode shapes of the thin-walled members composed of interconnected cylindrical shell panels is presented. The transfer matrix is derived from the differential equations for the cylindrical shell panels. The point matrix relating the state vectors between consecutive shell panels are used to allow the transfer procedures over the cross section of the members. As a result, the interactions between the shell panels of the cross sections of the members can be considered. Although the transfer matrix method is naturally a solution procedure for the one-dimensional problems, this method is well applied to thin-walled members by introducing the trigonometric series into the governing equations of the problem. The natural frequencies and vibration mode shapes of the thin-walled members composed of number of interconnected cylindrical shell panels are observed in this analysis. In addition, the effects of the number of shell panels on the natural frequencies and vibration mode shapes are also examined.
Frequency and Characteristics of Paraclinoid Aneurysm in Ruptured Cerebral Aneurysms
Hideaki Shigematsu,Kazuma Yokota,Akihiro Hirayama,Takatoshi Sorimachi 대한신경외과학회 2024 Journal of Korean neurosurgical society Vol.67 No.1
Objective : This study aimed to determine the frequency of paraclinoid aneurysms among ruptured cerebral aneurysms and compare paraclinoid aneurysms with other aneurysms to clarify the characteristics of ruptured paraclinoid aneurysms. Methods : This study included 970 ruptured cerebral aneurysms treated at our hospital between 2003 and 2020. Results : There were 15 cases (1.3%) of paraclinoid aneurysms with maximum diameters of 5–22 mm (mean±standard deviation [SD], 11.6±5.4 mm). Treatment consisted of clipping in four patients and endovascular treatment in 11. Factors significantly different in multivariate analysis for paraclinoid aneurysms compared with those for other aneurysms were a history of hypertension (odds ratio [OR], 1.2–9.8; p=0.021) and aneurysm ≥10 mm (OR, 7.5–390.3; p<0.001). The sites of paraclinoid aneurysm were ophthalmic artery type in nine patients, anterior wall type in five, medial wall type in one, and ventral wall type in zero. The medial wall type (22 mm) was significantly larger than the ophthalmic artery type (mean±SD, 7.2±2.0 mm) (p=0.003), and the anterior wall type (mean±SD, 12.2±4.8 mm) was significantly larger than the ophthalmic artery type (p=0.024). Conclusion : This study showed a low frequency of paraclinoid aneurysms among ruptured cerebral aneurysms. Most were upward-facing with relatively large aneurysms, and no aneurysms were smaller than 5 mm. With recent advances in endovascular treatment devices, paraclinoid aneurysms are easily treatable. However, the treatment indication of each paraclinoid aneurysm should be carefully considered.
Inoue Daisuke,Shigematsu Hideki,Nakagawa Yoshiyuki,Takeshima Toshichika,Tanaka Yasuhito 대한척추외과학회 2021 Asian Spine Journal Vol.15 No.3
Study Design: Prospective clinical study. Purpose: To determine the optimal posture for instability evaluation using flexion–extension X-ray imaging in patients with lumbar spondylolisthesis. Overview of Literature: Currently, flexion–extension X-ray imaging is the most practical approach for the evaluation of lumbar instability. In flexion–extension X-ray imaging, achievement of the greatest segmental motion with flexion–extension movement is necessary. However, to our knowledge, currently, there is no standardized posture for determining lumbar instability. Methods: Twenty-three individuals with lumbar spondylosis related to the fourth vertebra underwent flexion–extension X-ray imaging in different postures (standing, sitting, and lateral decubitus positions), lumbar magnetic resonance imaging (MRI), and low back pain Visual Analog Scale (VAS) evaluation on the same day. Intervertebral angle, percent slippage, and intervertebral disc area ratio for different postures during flexion and extension were compared using Tukey’s method. The effect of low back pain and the association between MRI facet effusion and these measurements were investigated according to posture. Results: The percent slippage during extension (p=0.036), change in the percent slippage between flexion and extension (p=0.004), and change in the intervertebral angle (p=0.042) were significantly different between the sitting and lateral decubitus positions. There were also significant differences between the standing and lateral decubitus positions in the change in intervertebral angle (p=0.010). In patients with VAS score <40, there were significant differences in the intervertebral angle (p=0.011) between the standing and lateral decubitus positions, percent slippage (p=0.048), and intervertebral disk ratio (p=0.008) between the sitting and lateral decubitus positions. We found no relationship between MRI facet effusion and posture in terms of instability. Conclusions: In this study, intervertebral instability was best evaluated in the lateral decubitus position when using flexion–extension X-ray imaging for patients with fourth lumbar vertebral spondylolisthesis.