Interpretation of the mechanical behavior of embankments having various compaction properties based on the soil skeleton structure

AbstractAfter the Hanshin Awaji Earthquake disaster, the seismic resistance of embankments was evaluated, and design principles were changed from specification-based to performance-based. However, compaction properties and the mechanical behavior of compacted soil were not sufficiently considered in the Manual of Highway Earthworks on Embankments.The first objective of the present study is to reproduce the mechanical behavior of three embankment materials having different compaction properties. A series of triaxial compression tests and oedometer tests is carried out. The mechanical behavior is reproduced by the SYS Cam-clay model and the influence of compaction on the mechanical behavior is interpreted based on the soil skeleton structure. The second objective is to evaluate the seismic stability of the embankment, which depends on the compaction properties of the embankment material, using GEOASIA, a soil–water coupled finite deformation analysis code.The primary conclusions are as follows. (1) Through the triaxial tests, the maximum deviator stress increases as the degree of compaction, Dc, increases. However, the trends in the increase differ depending on the material. (2) Based on one-dimensional consolidation tests, the compression curve is approximately a straight line with a large vertical effective stress. In the present study, a greater maximum dry density corresponds to less compressibility and a lower compression curve. (3) The mechanical behavior of each material is reproduced by the SYS Cam-clay model using one set of material constants for each material and representing the differences in Dc by different initial conditions for the structure and overconsolidation. An increase in Dc causes the decay of the structure, as well as the accumulation of overconsolidation. In the case of material A, the decay of the structure and the loss of overconsolidation occur quickly, whereas in the case of material C, the decay of the structure is slight and the loss of overconsolidation is moderate. (4) The seismic response analysis reveals different deformations of the embankment for different materials, even for the same Dc. The seismic stability of the embankments was increased by increasing Dc. Materials, such as material A, that have fast decay of the structure and fast loss of overconsolidation produce embankments with high seismic stability

Application of PLD-Fabricated Thick-Film Permanent Magnets

Isotropic Nd-Fe-B thick-film magnets have been prepared using a pulsed laser deposition (PLD) method with the control of laser energy density (LED) followed by post-annealing. The characteristics of the method are a high deposition rate up to several tens of microns per hour together with a reliability of magnetic properties due to the good transfer of composition from an Nd-Fe-B target to a film. Several micro-machines comprising the isotropic Nd-Fe-B films such as a miniaturized DC motor and a swimming machine in liquid were demonstrated. Furthermore, the deposition of isotropic Nd (or Pr)-Fe-B thick-film magnets on a Si or glass substrate was carried out to apply the films to various micro-electro-mechanical-systems (MEMS). We also introduced the preparation of isotropic Sm-Co, Fe-Pt, and nano-composite Nd-Fe-B+α-Fe film magnets synthesized using the PLD

Identification of potential target genes for the tomato fruit-ripening regulator RIN by chromatin immunoprecipitation

<p>Abstract</p> <p>Background</p> <p>During ripening, climacteric fruits increase their ethylene level and subsequently undergo various physiological changes, such as softening, pigmentation and development of aroma and flavor. These changes occur simultaneously and are caused by the highly synchronized expression of numerous genes at the onset of ripening. In tomatoes, the MADS-box transcription factor RIN has been regarded as a key regulator responsible for the onset of ripening by acting upstream of both ethylene- and non-ethylene-mediated controls. However, except for <it>LeACS2</it>, direct targets of RIN have not been clarified, and little is known about the transcriptional cascade for ripening.</p> <p>Results</p> <p>Using immunoprecipitated (IPed) DNA fragments recovered by chromatin immunoprecipitation (ChIP) with anti-RIN antibody from ripening tomato fruit, we analyzed potential binding sites for RIN (CArG-box sites) in the promoters of representative ripening-induced genes by quantitative PCR. Results revealed nearly a 5- to 20-fold enrichment of CArG boxes in the promoters of <it>LeACS2</it>, <it>LeACS4</it>, <it>PG</it>, <it>TBG4</it>, <it>LeEXP1</it>, and <it>LeMAN4 </it>and of <it>RIN </it>itself, indicating direct interaction of RIN with their promoters <it>in vivo</it>. Moreover, sequence analysis and genome mapping of 51 cloned IPed DNAs revealed potential RIN binding sites. Quantitative PCR revealed that four of the potential binding sites were enriched 4- to 17-fold in the IPed DNA pools compared with the controls, indicating direct interaction of RIN with these sites <it>in vivo</it>. Near one of the four CArG boxes we found a gene encoding a protein similar to thioredoxin y1. An increase in the transcript level of this gene was observed with ripening in normal fruit but not in the <it>rin </it>mutant, suggesting that RIN possibly induces its expression.</p> <p>Conclusions</p> <p>The presented results suggest that RIN controls fruit softening and ethylene production by the direct transcriptional regulation of cell-wall-modifying genes and ethylene biosynthesis genes during ripening. Moreover, the binding of RIN to its own promoter suggests the presence of autoregulation for <it>RIN </it>expression. ChIP-based analyses identified a novel RIN-binding CArG-box site that harbors a gene associated with <it>RIN </it>expression in its flanking region. These findings clarify the crucial role of RIN in the transcriptional regulation of ripening initiation and progression.</p

Single-Crystal Organic Charge-Transfer Interfaces probed using Schottky-Gated Heterostructures

Organic semiconductors based on small conjugated molecules generally behave as insulators when undoped, but the hetero-interfaces of two such materials can show electrical conductivity as large as in a metal. Although charge transfer is commonly invoked to explain the phenomenon, the details of the process and the nature of the interfacial charge carriers remain largely unexplored. Here we use Schottky-gated heterostructures to probe the conducting layer at the interface between rubrene and PDIF-CN2 single crystals. Gate-modulated conductivity measurements demonstrate that interfacial transport is due to electrons, whose mobility exhibits band-like behavior from room temperature to ~ 150 K, and remains as high as ~ 1 cm2V-1s-1 at 30 K for the best devices. The electron density decreases linearly with decreasing temperature, an observation that can be explained quantitatively based on the heterostructure band diagram. These results elucidate the electronic structure of rubrene-PDIF-CN2 interfaces and show the potential of Schottky-gated organic heterostructures for the investigation of transport in molecular semiconductors.Comment: 37 pages, 9 Figures (including supplementary information