Basic rockfall simulation with consideration of vegetation and application to protection measure

金沢大学理工研究域環境デザイン学系The estimation of risk due to rockfall is often done empirically. As a rational and effective method towards performance-based design of protection measures, a three-dimensional simulation method helps to describe the motion of rockfall on a slope and to consider the effect of vegetation probabilistically. This document details a typical simulation method and analyses the manner of rockfalls paired with interference of vegetation and other factors. As application, an actual slope is analyzed where rockfall occurred during the Noto Peninsula Earthquake. Finally, the validity and the benefits of the shown method are the basis for a hazard mapping for rockfall and the planning of measures

Basic rockfall simulation with consideration of vegetation and application to protection measure

The estimation of risk due to rockfall is often done empirically. As a rational and effective method towards performance-based design of protection measures, a three-dimensional simulation method helps to describe the motion of rockfall on a slope and to consider the effect of vegetation probabilistically. This document details a typical simulation method and analyses the manner of rockfalls paired with interference of vegetation and other factors. As application, an actual slope is analyzed where rockfall occurred during the Noto Peninsula Earthquake. Finally, the validity and the benefits of the shown method are the basis for a hazard mapping for rockfall and the planning of measures

Depolarization of multidomain ferroelectric materials

Depolarization in ferroelectric materials has been studied since the 1970s, albeit quasi-statically. The dynamics are described by the empirical Merz law, which gives the polarization switching time as a function of electric field, normalized to the so-called activation field. The Merz law has been used for decades; its origin as domain-wall depinning has recently been corroborated by molecular dynamics simulations. Here we experimentally investigate domain-wall depinning by measuring the dynamics of depolarization. We find that the boundary between thermodynamically stable and depolarizing regimes can be described by a single constant, Pr/ε0εferroEc. Among different multidomain ferroelectric materials the values of coercive field, Ec, dielectric constant, εferro, and remanent polarization, Pr, vary by orders of magnitude; the value for Pr/ε0εferroEc however is comparable, about 15. Using this extracted universal value, we show that the depolarization field is similar to the activation field, which corresponds to the transition from creep to domain-wall flow.Aerospace Structures & MaterialsNovel Aerospace Material

Properties and crystallization of a genetically engineered, water-soluble derivative of penicillin-binding protein 5 of Escherichia coli K12

Derivatives of the Escherichia coli penicillin-binding protein 5 (PBP5) with truncated carboxyl terminals were obtained by altering the carboxyl-coding end of the dacA gene. After cloning the modified dacA gene into a runaway-replication-control plasmid, one clone that overproduced and excreted the desired protein into the periplasm was used as a source for the isolation of a water-soluble PBP5 (i.e. PBP5S). In PBP5S the carboxyl-terminal 21-amino-acid region of the wild-type protein was replaced by a short 9-amino-acid segment. Milligram amounts of PBP5S were purified by penicillin affinity chromatography in the absence of detergents or of chaotropic agents. PBP5S was stable and possessed DD-carboxypeptidase activity without added Triton X-100. Upon reaction with [14C]benzylpenicillin it was converted into a rather short-lived acyl-enzyme complex, as observed with PBP5. Both PBP5 and PBP5S were crystallized. In contrast to PBP5, PBP5S yielded enzymatically active, well-formed prismatic crystals suitable for X-ray analysis