Nanomechanical system meets ultra-small, robust, and ultra-low-powered digital communication receiver

Nanomechanical systems offer a versatile platform for both fundamental science and industrial applications. Resonating vibration has been demonstrated to enable an ultrasensitive detection of various physical quantities, with emerging applications including signal processing, biological detection and fundamental tests of quantum mechanics. It has also been shown that the mechanical vibration of a nanoscale cantilever can be used to detect electromagnetic analogue-modulated waves. However, signals obtained with nanoscale receivers are so weak that the data transfer often fails; to the best of our knowledge, no successful practical demonstration has yet been reported. Here, we present the first experimental demonstration of the use of nanomechanical systems for digital data transfer with a digital image. Furthermore, our fabrication method achieved a tiny gap around field emitter of vibrational nano-antenna, which enables the receiver to work with quite a low power consumption, on the order of 10nW

地震発生帯における深部掘削孔を用いた長期計測

Large earthquakes occur frequently in subduction zones. Most earthquakes are generated in the seismogenic zone, a fairly limited area confined to the shallower regions of the subduction plate boundary. To understand the processes of earthquake generation, it is essential to monitor the physical and mechanical properties of the seismogenic zone over long periods. At present, there are no deep borehole observations of the seismogenic zone more than 3km below seafloor, because it has, until now, been impossible to penetrate to such depths below the sea floor. The Integrated Ocean Drilling Program (IODP), scheduled to begin in 2003, plans to drill boreholes beneath the ocean floor using a multiple-drilling platform operation. The IODP riser-quipped drilling ship (Chikyu) enables the emplacement of boreholes up to 0km beneath the ocean floor, and will provide opportunities to conduct long-term deep borehole observations in the seismogenic zone. Long-term borehole observations in the seismogenic zone are expected to require the development of advanced sampling, monitoring, and recording technology. Here, we discuss the scientific objectives, engineering and technical challenges, and experimental design for a deep borehole, long-term deepborehole monitoring system aimed at understanding the processes of earthquake generation in the seismogenic zone of subduction plate boundaries. We focus specifically on the relationships between environmental conditions in the deep subsurface, details of monitoring and recording, and design and implementation of scientific tools and programs

Structure and Physical Properties of Fracture Zone Derived From Seismic Observations at the Nojima Fault and the Western Tottori Earthquake Fault, Japan

Research on active faults, their structure, physical properties, and fault behavior during an earthquake cycle is important for the earthquake prediction. In this paper, we summarize the results of our seismological analyses of shear-wave splitting and injection-induced earthquakes on the basis of seismic observations at active faults. The shear-wave splitting observations performed on the fracture zone of the 2000 Western Tottori, Japan, earthquake revealed the fracture distribution inside the fracture zone, causing about 1% anisotropy. We can detect the detailed fracture distribution inside a fracture zone through shear-wave splitting observations with a dense (less than several kilometers in interval) seismic array set on and along the fracture zone. The analysis of earthquakes induced by water injection experiments at the Nojima fault, Japan, depicted that the fracture zone is permeable and has a low coefficient of friction immediately after the mainshock. Long-term monitoring of clustered microearthquake activity at the Nojima fault revealed the heterogeneity of crustal strength. We point out that we need to clearly define “fracture zone” for each research background in discussions of fracture zones because the thickness of the fracture zone varies depending on the research method

本震直後における断層の物理的特性とその時間変化

京都大学0048新制・課程博士博士(理学)甲第8162号理博第2184号新制||理||1155(附属図書館)UT51-2000-F66京都大学大学院理学研究科地球惑星科学専攻(主査)教授 安藤 雅孝, 教授 竹本 修三, 教授 Mori J.James学位規則第4条第1項該当Doctor of ScienceKyoto UniversityDA

A Case of Intussusception Associated with Pneumatosis Cystoides Intestinalis

Pneumatosis cystoides intestinalis (PCI) is an uncommon disease that generally lacks symptoms and is rarely associated with intussusception. A 29-year-old man visited our hospital for right upper abdominal pain. Computed tomography (CT) scan revealed multiple air-filled cysts along the intestinal wall and a pseudokidney sign in the transverse colon. A gastrographin enema examination showed a so-called crab finger appearance and multiple elevated translucency in the transverse colon. From these findings, the diagnosis of intussusception associated with PCI was made. The enema and manipulative reduction improved the intussusception. Comparing the enema findings before and after the reduction, we thought that mobile cecum could play an important role in the intussusception. Colonoscopy was performed after the reduction and showed multiple elevated lesions in the ascending colon, which were similar to cluster of grapes. The CT scan of the next day revealed no recurrence of the intussusception, and the patient has not had symptoms of recurrence ever since

Seafloor Geodesy Data Standardization Task Force within the Inter-Commission Committee on Marine Geodesy (ICCM) report for the International Association of Geodesy (IAG)

Since the 19th of October 2022, representatives of the seafloor geodesy community meet on a regular basis within an ad hoc working group called the Seafloor Geodesy Data Standardization Task Force (SFGDSTF). This task force has been placed under the umbrella of the IAG's Inter-Commission Committee on Marine Geodesy (ICCM)