Stiffness and Damping of Sands in Torsion Shear

A laboratory investigation was carried out into stiffness and damping of sands as sheared in a torsional shear apparatus. In the drained monotonic and cyclic loading tests, a particular care was taken of the small strain measurements in which the secant stiffness was measured over a wide range of shear strain from about 10-6 to 10-2. Despite the marked differences in the grain size and the sample preparation method among the sands, a fairly good coincidence of the secant stiffness was seen, in common, in the range of shear strain less than about 1 x 10-5 between two types of tests using the monotonic and cyclic loadings. However, the response was softer in the monotonic loading tests for the larger strains. It has also been pointed out that the damping when examined in relation to the normalized secant shear modulus was scarcely affected by the confining pressure, and that the values of damping were smaller than those so far available in the literature

Study of hadron interactions in a lead-emulsion target

Topological and kinematical characteristics of hadron interactions have been studied using a lead-emulsion target exposed to 2, 4 and 10 GeV/c hadron beams. A total length of 60 m $\pi^-$ tracks was followed using a high speed automated emulsion scanning system. A total of 318 hadron interaction vertices and their secondary charged particle tracks were reconstructed. Measurement results of interaction lengths, charged particle multiplicity, emission angles and momenta of secondary charged particles are compared with a Monte Carlo simulation and appear to be consistent. Nuclear fragments emitted from interaction vertices were also detected by a newly developed emulsion scanning system with wide-angle acceptance. Their emission angle distributions are in good agreement with the simulated distributions. Probabilities of an event being associated with at least one fragment track are found to be greater than 50% for beam momentum $P > 4$ GeV/c and are well reproduced by the simulation. These experimental results validate estimation of the background due to hadron interactions in the sample of $\tau$ decay candidates in the OPERA $\nu_{\mu} \to \nu_{\tau}$ oscillation experiment.Comment: 14 pages, 11 figure

Isolation and function of mouse tissue resident vascular precursors marked by myelin protein zero

Newly identified tissue-resident vascular precursor cells are recruited into growing vessels and contribute to vasculogenesis in adult mice

Finishing the euchromatic sequence of the human genome

The sequence of the human genome encodes the genetic instructions for human physiology, as well as rich information about human evolution. In 2001, the International Human Genome Sequencing Consortium reported a draft sequence of the euchromatic portion of the human genome. Since then, the international collaboration has worked to convert this draft into a genome sequence with high accuracy and nearly complete coverage. Here, we report the result of this finishing process. The current genome sequence (Build 35) contains 2.85 billion nucleotides interrupted by only 341 gaps. It covers ∼99% of the euchromatic genome and is accurate to an error rate of ∼1 event per 100,000 bases. Many of the remaining euchromatic gaps are associated with segmental duplications and will require focused work with new methods. The near-complete sequence, the first for a vertebrate, greatly improves the precision of biological analyses of the human genome including studies of gene number, birth and death. Notably, the human enome seems to encode only 20,000-25,000 protein-coding genes. The genome sequence reported here should serve as a firm foundation for biomedical research in the decades ahead

Undrained behaviour of granular materials under principal stress rotation.

Imperial Users onl

マーケティング研究におけるケース・スタディの方法論

マーケティング科学の方法論 / 監修: 嶋口充輝、川又啓子, 余田拓郎, 黒岩健一郎編著、白桃書房、2009.4、ISBN:978456166181

Case Study on Causes and Countermeasures of a Largely Deformed Reinforced Earth Wall with Geotextile in Hyogo, Japan

International Symposium on Backwards Problem in Geotechnical Engineering and Monitoring of Geo-Construction, Green Hall, Kensetsu-Koryu-kan, 2011/07/14-15This study examines causes and countermeasures of large deformation that took place on the reinforced earth wall, a part of the Tottori expressway planned to pass Hyogo, Japan. Since this reinforced earth wall had experienced unexpected deformation of the wall during construction, the wall was re-constructed twice. However, the wall deformation showed no sign to cease even at the final stage of the construction. In this paper, case study was carried out on the interpretation of the mechanical behavior of the severely damaged reinforced earth wall comprising geotextile with the concrete panel facing. At First, the outline of the damaged reinforced earth wall is in detail described. The background and cause of the damage are discussed based on the results of site investigation. The engineering properties of the fill were examined by performing various insitu and laboratory tests, including the surface wave survey (SWS), PS-logging, RI-logging, soaking test, the direct shear box (DSB) test, bender element (BE) test, etc. Consequently, the background as well as the cause for the damage of the wall may be described such that i) a considerable amount of settlement took place over a 3m thick weak soil layer in the lower part of the reinforced earth due to seepage of rainfall water, ii) the weight of the upper fill was partially supported by the geo-textile hooked on the concrete panels (n.b., named conveniently "hammock state" in this paper), and iii) the concrete panels to form the hammock were severely damaged by the unexpectedly large downwards compression force triggered by the tension force of the geotextile. And then, numerical analysis was carried out in order to simulate the development of the large deformation that took place on the reinforced earth wall and countermeasures to re-stabilize the wall were demanded. As the results of site investigation, it was manifested that subsidence of a 3-meter weak soil due to seepage flow was responsible for the large deformation. A part of concrete panel wall was severely damaged due to extremely large pulling force of geotextile induced by the hammock state. As for the countermeasures, "grouting with slag system" was applied to fill voids of the backfill, and also to prevent further development of settlement in the weak soil layer. "Ground anchor" was also considered to achieve the prescribed factor of safety