Geophysics in the Western Pacific Environment : Detection of formation boundaries and permeable fractures based on frequency-domain Stoneley wave logs

( Hiroyuki Saito ),( Kazuo Hayashi ),( Yoshikazu Iikura ) 한국지구물리탐사학회 2004 지구물리와 물리탐사 Vol.7 No.1

Detection of formation boundaries and permeable fractures based on frequency-domain Stoneley wave logs

Saito Hiroyuki,Hayashi Kazuo,Iikura Yoshikazu Korean Society of Earth and Exploration Geophysici 2004 지구물리와 물리탐사 Vol.7 No.1

This paper describes a method of detecting formation boundaries, and permeable fractures, from frequency-domain Stoneley wave logs. Field data sets were collected between the depths of 330 and 360 m in well EE-4 in the Higashi-Hachimantai geothermal field, using a monopole acoustic logging tool with a source central frequency of 15 kHz. Stoneley wave amplitude spectra were calculated by performing a fast Fourier transform on the waveforms, and the spectra were then collected into a frequency-depth distribution of Stoneley wave amplitudes. The frequency-domain Stoneley wave log shows four main characteristic peaks at frequencies 6.5, 8.8, 12, and 13.3 kHz. The magnitudes of the Stoneley wave at these four frequencies are affected by formation properties. The Stoneley wave at higher frequencies (12 and 13.3 kHz) has higher amplitudes in hard formations than in soft formations, while the wave at lower frequencies (6.5 and 8.8 kHz) has higher amplitudes in soft formations than in hard formations. The correlation of the frequency-domain Stoneley wave log with the logs of lithology, degree of welding, and P-wave velocity is excellent, with all of them showing similar discontinuities at the depths of formation boundaries. It is obvious from these facts that the frequency-domain Stoneley wave log provides useful clues for detecting formation boundaries. The frequency-domain Stoneley wave logs are also applicable to the detection of a single permeable fracture. The procedure uses the Stoneley wave spectral amplitude logs at the four frequencies, and weighting functions. The optimally weighted sum of the four Stoneley wave spectral amplitudes becomes almost constant at all depths, except at the depth of a permeable fracture. The assumptions that underlie this procedure are that the energy of the Stoneley wave is conserved in continuous media, but that attenuation of the Stoneley wave may occur at a permeable fracture. This attenuation may take place at anyone of the four characteristic Stoneley wave frequencies. We think our multispectral approach is the only reliable method for the detection of permeable fractures.

Isolation of Sterile Mutants of Floricultural Plants Using Heavy-Ion Beam Irradiation

Hiroyuki Saito,Yoriko Hayashi,Nobuhisa Fukunishi,Hiromichi Ryuto,Ken-ichi Suzuki,Takeshi Kanaya,Masao Sugiyama,Teruhiko Terakawa,Norihiro Otsubo,Ryutaro Aida,Tomoko Abe 한국원예학회 2006 한국원예학회 기타간행물 Vol.- No.-

A Fabrication of a Needle-Shaped Implantable Microelectrode Array for Neural Recording Using HF-HNO₃-CH₃COOH Solution

Hiroyuki Saito,Yoshifumi Sekine 대한전자공학회 2009 ITC-CSCC :International Technical Conference on Ci Vol.2009 No.7

Many kinds of microelectrodes for recording have been fabricated using MEMS technology. It is difficult, however, for conventional microelectrodes to record the signals of closely spaced neurons. In addition, the tip of any implantable microelectrode must be sharp so that it only touches a single neuron. In this paper, we focus on the fabrication of needle-shaped implantable microelectrode array for the neural recording. We use a HF-HNO₃-CH₃COOH solution for isotropically wet etching of silicon to fabricate implantable microelectrodes in which the tip of the implantable microelectrodes is sharp. We show an etching time vs. diameter characteristics of the tip and bottom using a HF-HNO₃-CH₃COOH solution. After the wet etching, the implantable microelectrodes have a needle shape. As a result, we show the effectiveness of our microelectrode array fabrication process.

Heterologous Production and Structure Determination of a New Lanthipeptide Sinosporapeptin Using a Cryptic Gene Cluster in an Actinobacterium Sinosporangium siamense

Saito Keita,Mukai Keiichiro,Kaweewan Issara,Nakagawa Hiroyuki,Hosaka Takeshi,Kodani Shinya 한국미생물학회 2023 The journal of microbiology Vol.61 No.6

Lipolanthine is a subclass of lanthipeptide that has the modification of lipid moiety at the N-terminus. A cryptic biosynthetic gene cluster comprising four genes (sinA, sinKC, sinD, and sinE) involved in the biosynthesis of lipolanthine was identified in the genome of an actinobacterium Sinosporangium siamense. Heterologous coexpression of a precursor peptide coding gene sinA and lanthipeptide synthetase coding gene sinKC in the host Escherichia coli strain BL21(DE3) resulted in the synthesis of a new lanthipeptide, sinosporapeptin. It contained unusual amino acids, including one labionin and two dehydrobutyrine residues, as determined using NMR and MS analyses. Another coexpression experiment with two additional genes of decarboxylase (sinD) and N-acetyl transferase (sinE) resulted in the production of a lipolanthine-like modified sinosporapeptin.

Investigation of axial-injection end-burning hybrid rocket motor regression

Saito, Yuji,Yokoi, Toshiki,Neumann, Lukas,Yasukochi, Hiroyuki,Soeda, Kentaro,Totani, Tsuyoshi,Wakita, Masashi,Nagata, Harunori Techno-Press 2017 Advances in aircraft and spacecraft science Vol.4 No.3

The axial-injection end-burning hybrid rocket proposed twenty years ago by the authors recently recaptured the attention of researchers for its virtues such as no ${\zeta}$ (oxidizer to fuel mass ratio) shift during firing and good throttling characteristics. This paper is the first report verifying these virtues using a laboratory scale motor. There are several requirements for realizing this type of hybrid rocket: 1) high fuel filling rate for obtaining an optimal ${\zeta}$; 2) small port intervals for increasing port merging rate; 3) ports arrayed across the entire fuel section. Because these requirements could not be satisfied by common manufacturing methods, no previous researchers have conducted experiments with this kind of hybrid rocket. Recent advances in high accuracy 3D printing now allow for fuel to be produced that meets these three requirements. The fuel grains used in this study were produced by a high precision light polymerized 3D printer. Each grain consisted of an array of 0.3 mm diameter ports for a fuel filling rate of 98% .The authors conducted several firing tests with various oxidizer mass flow rates and chamber pressures, and analysed the results, including ${\zeta}$ history, using a new reconstruction technique. The results show that ${\zeta}$ remains almost constant throughout tests of varying oxidizer mass flow rates, and that regression rate in the axial direction is a nearly linear function of chamber pressure with a pressure exponent of 0.996.

Effects of a Vertical and Horizontal Console Position on Operator Muscular Stress During Ultrasonic Diagnosis

( Hiroyuki Suzuki ),( Takayoshi Saito ),( Tetsuo Katsuura ),( Yoshihiro Shimomura ) 한국감성과학회 2014 춘계학술대회 Vol.2014 No.-

A diagnostic ultrasound system is an apparatus to aid in examination and diagnosis by displaying cross-sectional images of body tissues, their movements, and blood flow produced based on the intensities and phases of reflected echoes. Most the operators operate the probe by the right hand and the operation panel by the left hand during ultrasonic diagnosis in Japan. Ultrasound examinations tend to put sonographers in unnatural postures, which may lead to musculoskeletal disorders. In this study, we focused on the height and the horizontal positioning of the operation panel of the diagnostic ultrasound system to quantitatively assess the influence of panel height (work plane height) and work plane position on musculoskeletal stress during scanning in a sitting position. Eight subjects (6 males and 2 females) were asked to perform a simulated scanning task that involved touching 9 points on the operation panel at 4 different panel heights. Five subjects (2 males and 3 females) were asked to perform a simulated scanning task that involved touching fie points on the control panel, with the work plane set at different positions in space. Electromyograms of each part of the body and wrist joint angles indicated that the optimum height of the operation panel during scanning in a sitting position was elbow height, the least stressful position of the left hand was about 350 mm from the center of the trunk in the longitudinal (front-back) direction and 100 mm left of the center of the trunk in the lateral (right-left) direction.

A Realistic RBF Approximation of Chaotic Dynamics

Hiroyuki Shibayama,Toshimichi Saito 대한전자공학회 1996 ITC-CSCC :International Technical Conference on Ci Vol.- No.-

Endoscopic Ultrasonography Miniature Probe Performance for Depth Diagnosis of Early Gastric Cancer with Suspected Submucosal Invasion

Hiroyuki Takamaru,Shigetaka Yoshinaga,Hajime Takisawa,Ichiro Oda,Hitoshi Katai,Shigeki Sekine,Kazuhiro Taniguchi,Yutaka Saito 거트앤리버 소화기연관학회협의회 2020 Gut and Liver Vol.14 No.5

Background/Aims: The accurate assessment of the depth of invasion of early gastric cancer (EGC) is critical to determine the most appropriate treatment option. However, it is difficult to distinguish shallow submucosal (SM1) invasion from deeper submucosal (SM2) invasion. We investigated the diagnostic performance of endoscopic ultrasonography (EUS) using a miniature probe for EGC with suspected SM invasion. Methods: From April 2008 to June 2018, EGCs with suspected SM invasion were analyzed retrospectively. The EGCs examined by a 20 MHz high-frequency miniature probe was included in our study. Esophago-gastric junction cancers and patients treated by chemotherapy before resection were excluded. The sensitivity and specificity for the detection of SM2 invasion by EUS were compared with those of white light imaging (WLI). Additionally, factors related to depth underestimation or overestimation were investigated using multivariate analysis. Results: A total of 278 EGCs in 259 patients were included in the final analysis. The sensitivity and specificity for SM2 or deeper by EUS were 73.7% (87/118) and 74.4% (119/160), respectively. The sensitivity and specificity by WLI were 47.5% (56/118) and 68.1% (109/160), respectively. The sensitivity of EUS was significantly superior to that of conventional endoscopy (p<0.01). Multivariate analysis revealed that an anterior location of the EGC was an independent risk factor for underestimation by EUS (odds ratio, 3.3; 95% confidence interval, 1.1 to 9.8; p=0.03). Conclusions: The depth diagnostic performance for EGCs with suspected SM invasion using EUS was satisfactory and superior to that of conventional endoscopy. Additionally, it is important to recognize factors that may lead to misdiagnosis in those lesions.

Effects of a vertical and horizontal console position on operator muscular stress during ultrasonic diagnosis

Hiroyuki Suzuki,Takayoshi Saito,Tetsuo Katsuura,Yoshihiro Shimomura 대한인간공학회 2014 대한인간공학회 학술대회논문집 Vol.2014 No.5

A diagnostic ultrasound system is an apparatus to aid in examination and diagnosis by displaying cross sectional images of body tissues, their movements, and blood flow produced based on the intensities and phases of reflected echoes. Most the operators operate the probe by the right hand and the operation panel by the left hand during ultra -sonic diagnosis in Japan.Ultrasound examinations tend to put sonographers in unnatural postures, which may lead to musculoskeletal disorders. In this study, we focused on the height and the horizontal positioning of the operation panel of the diagnostic ultra -sound system to quantitatively assess the influence of panel height (work plane height) and work plane position on musculoskeletal stress during scanning in a sitting position. Eight subjects (6 males and 2 females) were asked to perform a simulated scanning task that involved touching 9 points on the operation panel at 4 different panel heights. Five subjects (2 males and 3 females) were asked to perform a simulated scanning task that involved touching five points on the control panel, with the work plane set at different positions in space. Electromyograms of each part of the body and wrist joint angles indicated that the optimum height of the operation panel during scanning in a sitting position was elbow height, the least stressful position of the left hand was about 350 mm from the center of the trunk in the longitudinal (front–back) direction and 100 mm left of the center of the trunk in the lateral (right–left) direction. The height of the operation panel during scanning in a sitting position affects the stress on the forearm and shoulder. We indicated that the optimum height of the operation panel was elbow height. The longitudinal position of the control panel during scanning in a sitting position affected the stress in the left forearm and left lumbar regions. The lateral position of the control panel during scanning in a sitting position affected the stress in the left shoulder rgion.We indicated that the least stressful position of the left hand was these on the horizontal positioning of the operation panel.