Search

平成29年度衝撃波シンポジウム (2018年3月7日-9日. 東北大学片平さくらホール ）仙台市, 宮城県, (2018年3月7日-9日. 宇宙航空研究開発機構角田宇宙センター ）角田市, 宮城県, Symposium on Shock Waves in Japan, FY2017 (March 7-9, 2018. Sakura Hall), Sendai, Miyagi, (March 7-9, 2018. Kakuda Space Center, Japan Aerospace Exploration Agency (JAXA)(KSPC)), Kakuda, Miyagi, 資料番号: SA6000119102, レポート番号: 3B1-5【若】

結晶性のアイソタクチックポリスチレンに対して，融点より十分高い温度においてせん断を印加すると配向構造が観測される．この配向構造に着目し，偏光顕微鏡測定・偏光光散乱測定，小角・広角 X 線散乱測定を行った．通常の融点(223℃)より高温においてせん断を印加したときに観測されるミクロンスケールの配向構造は 250℃ にて，一日以上アニールしても融解せずにそのまま存在していた．しかし，昇温すると 270℃ 付近で融解した．また，この配向構造を通常の融点以下に冷却した場合，配向構造を中心にいわゆるシシケバブ構造が成長していた．さらに，アイソタクチックポリスチレンで観測される融点以上での配向構造の形成過程を明らかにするために，配向構造のせん断印加速度およびひずみ量による変化に着目して，顕微鏡観察を行い，臨界せん断速度，臨界ひずみ量の存在を示した．ポリオレフィン系高分子における融点以下でのせん断流動場結晶化でも，臨界ひずみ量，臨界せん断速度が評価できたことから，アイソタクチックポリスチレンにおいて観測された配向構造はせん断による高分子鎖の配向と緩和プロセスに依存していると考えられる．

Supervisor: 橋本 敬, 知識科学研究科, 修士

Recently it is often announced that an abnormality of electromagnetic wave is observed before an earthquake. Especially, a time series of it in Hanshin-Awaji Great Earthquake tells us the possibility of an earthquake prediction. We get the observation results in Niigata-Chuetsu Earthquake (October 23,2004; M6.8) and Sanriku oiling Earthquake (November 15,2005; M6.9). The relation between the frequency of abnormal electromagnetic wave and the outbreak time on both logarithms graph are expressed as the experimental equations, as well as the case of Hanshin-Awaji Great Earthquake. These equations are effective to foresee an outbreak time of earthquake and its magnitude. On the other hand, another method of the earthquake prediction is also introduced according the consideration for the distribution of observation points on the above graph.

The development for the observation framework of the happening of the earthquake has been matured, and so is the alerting system. However, there has not been a systemic attempt to research the pre-phenomenon to the occurrence of the earthquake. Recently, there has been reported that the abnormality in the electro-magnetic field is observed prior to the happening of the earthquake. We must put more effort to the observation of the precursor phenomenon as the physical phenomenon. Even the researchers of the earthquake can not directly observe the epicenter of the earthquake physically, since most of the time the epicenter is located deep down the surface of the earth. We can take the human body as an analogy, that in order to observe the source of the disease, we do not have such device as the endo-scope to look into the cause of the problem. Earthquake is a phenomenon that the curst of the bedrock stratum is broken and the large-scale magnitude of oscillation is created. At the local level of the destroyed crust, the accumulation of the energy of large scale is progressed, which leads to the destruction of the crust at the end, surpassing its limit. The composition of the earth's crust is the interstratifying of the cluster energy at various levels in order to form the material. Therefore, at the core of the earth, throughout the course of energy accumulation, whenever the energy level is surpassed by the clustering of each type of energy, the cluster condition is broken, and it is assumed that the emission of the electro-magnetic wave as the precursor phenomenon occur as the corresponding energy. Within several years, some data on the abnormality of the electro-magnetic wave are observed as the precursor phenomenon, and such data are introduced. We are making an attempt to demonstrate that such energy of electro-magnetic wave as the precursor phenomenon are progressing in accordance with the degree of energy, from low level to the high level.

In Atsumari district of Minamata city, Kumamoto prefecture, the debris flowed on July 20, 2003. Fifteen persons were killed and houses were destroyed. The purpose of this paper is to study the behaviors and consciousness of the residents of Atsumari district during the heavy rainfalls and the debris flow. Evacuation behaviors and existence of precursor to debris flows were investigated by interviewing the residents who were looking at the Atsumari River and its flood situation. Primary knowledge about precursor to debris flows, the main mental focus of the residents during heavy rainfalls, evacuation behaviors, search and rescue behaviors to the victims after debris flow, living in temporary housing and, recovery and reconstruction plan of residents were studied by means of questionnaire survey. The residents watched the flooding of Atsumari River. They did not seek refuge even when they saw the phenomenon that is considered precursor to a debris flow. Also the result of the questionnaire clearly indicated that there is little knowledge regarding debris flow.

Some of the observation data are introduced as the pre-phenomenon for the earthquake. It is a fact that these data are gathered in advance to the occurrence of earthquake as abnormality of the electro-magnetic wave. However, the frequency of the recorded data of electro-magnetic wave differs by each researcher. Furthermore, it is not yet known whether such irregularity is a triggering phenomenon from outside force for the main earthquake to be induced, or an evidence for the leakage of micro-release of the energy which are stored in the core of the earthquake, which will lead to the main earthquake to happen. In this paper, the discussion is based on the hypothesis of the release of electromagnetic wave as the energy discharge which is the pre-condition for the earthquake to happen. The data are collected from a wide range of environmental electro-magnetic wavelength as a light illuminating phenomenon, using the automatic recording device. Also, the development method for prediction of the earthquake is introduced by trying to establish a relationship between the electro-magnetic wavelength (energy) and the time of its occurrence.

Porous aluminum is a multifunctional material with lightweight and high energy absorption properties. In this study using AlO50 and A6061 (Al-Si-Mg aluminum alloy), functionally graded porous aluminum was fabricated by friction stir processing (FSP) route precursor method. First, AlO50 and A6061 precursors were fabricated separately by FSP route. Next, these precursors were bonded by friction stir welding (FSW） and composite graded precursor was fabricated. Finally, a precursor was heat treated for foaming and AlO50-A6061 functionally graded porous aluminum was fabricated. By EPMA observation, existence of Mg atoms was gradually changing at the bonding region. It was shown that seamless functionally graded porous aluminum can be fabricated by FSP route．

A composite structural material with an“AlO50porousaluminum/SS400 dense steel plate” is fabricated by friction stir welding(FSW), which is used both for mixing blowing agent powder with aluminum plates and for lap joining aluminum and steel plates in the same process. It is shown that, after the aluminum plates are foamed, diffusion bonding is realized and an Fe-Al intermetallic compound is formed at the interface of porous aluminum and dense steel. This is because new surfaces of aluminum and steel plates are formed by FSW, and thus bonding is realized at the interface of these plates immediately after FSW.

The debris flow in Harihara district of Izumi City, Kagoshima, occurred at O : 42 a.m. on July 10,1997 after the heavy rainfalls. Twenty one persons were killed and 19 houses were destroyed. The questionnaire survey is undertaken to study the behaviors and consciousness of the residents of Harihara district. The transmission of information, precursor, and evacuation are discussed. The conclusions of this study are as follows. (1) Residents of Harihara district had no preliminary knowledge about precursor of debris flow. (2) Residents paid attention to Harihara river and sabo dam during rainfall. However, they paid no attention after water level decreased. They did not worry about the debris flow. They could not evacuate from the debris flow in advance. (3) Mutual aid among neighborhood was very useful to relief the victims of the debris flow.

A small earthquake of M 4.5 occurred on December 27, 1992 at the southern border of Tsunan Town, the southern Niigata prefecture. The school buildings and gymnasiums at the epicentral area were seriously destructed by the quake. As no serious damages have been reported in recent Japan by the earthquakes of magnitude less than5, the damages were unusually large due to extremely shallow focal depth of 2 to 3 km. The distribution of the earthquake intensity on the scale of Japan Meteorological Agency is described with behavior of people at earthquake emergency. A historical review of local destructive earthquakes gives a conclusion that at an average interval of every five years local destructive earthquakes have been taken place in the southern Niigata prefecture. A seismo-geological interpretation based on the tectonic deformation of river terraces formed along the Shinano river reviles that the rate of uplifting of the studied area has been increased at 2 mm/year during last 50,000 years forming a dome structure of the Matsunoyama geothermal area. Before the earthquake thermal water anomalies occurred at the epicentral area.

A couple of earthquakes of M 5.4 and 5.3 occurred at 18:18 and 18:40, December 7, 1990 in the central part of the Higashi-Kubiki Hills, southern Niigata Prefecture and followed by considerable number of earthquakes for 2 months. Daily frequency of the earthquakes observed by 3 seismograms stationed in the mountains and a map of epicenters obtained are described. Many epicenters of the after shocks are distributed in a westerly area 5 to 10 km away from the main shocks. Since 1962, several earthquakes associated with strong explosive sounds have been recognized by inhabitants and suggest the area is marked by repeated shallow earthquake activities.

ZrSiO_4 powders were prepared from partially hydrolyzed solutions of Si(OC_2H_5)_4 (TEOS) and ZrOCl_2 aqueous solutions by the sol-gel processing, and the influence of amount of water for partial hydrolysis of TEOS,pH of the ZrOCl_2, aqueous solution and mixing time on the formation rate of ZrSiO_4 was investigated. The preparation conditions were evaluated by the formation rate of ZrSiO_4 after 1.5 wt% ZrSiO_4 seed crystals were added to the precursor powders and then the powder mixtures were heated at 1200°to 1500℃ for 2h. In the preparation of ZrSiO_4 composition precursor gels from TEOS-ZrO_2 sol and SiO_2 sol-ZrOCl_2, the H_2O/TEOS molar ratio of about 2 and the pH of the ZrOCl_2 aqueous solution of about 3 were appropriate. About 2h were necessary for mixing of partially hydrolyzed solution of TEOS and ZrOCl_2 aqueous solution to improve the homogeneity of precursor sols, and more than 10 h was required for the mechanical mixing of precursor sols. The formation of ZrSiO_4 produced by firing the precursor sols obtained from the partially hydrolyzed solution of TEOS and ZrOl_2 aqueous solution at 1300° to 1400℃ showed an accelerative increase through the Hedvall effect by silica., rights: 社団法人日本セラミックス協会rights: 本文データは学協会の許諾に基づきCiNiiから複製したものであるrelation: IsVersionOf: http://ci.nii.ac.jp/naid/110002289116/