Hiroshi Noguchi

Elastic layer-structured metal organic frameworks (ELMs)

Elastic layer-structured metal organic frameworks (ELMs) having flexible two-dimensional structure show a gate phenomenon in sorption/desorption of simple gas molecules. The gate phenomenon is accompanied by expansion/shrinkage of the layers. The gas sorption/desorption is not based on a physical adsorption, but on a chemical reaction, which includes high cooperativity. The cooperative reaction could be analyzed thermodynamically. The gate phenomenon showed advantages in separation of CO2 from mixed gases and in storage of CH4 owing to easy release of absorbed molecules.

Partial mass isolation in tall buildings

To find an economical approach in the seismic design of tall buildings, it is proposed to isolate a part of the structure by an isolator layer located in the height of building. Application of this technique causes a fundamental change in basic dynamic characteristics of the system. As a result, all major modal shapes of structure exhibit large displacement at the level of the isolator. A viscous damping device integrated into the isolation layer utilizes this relative movement to effectively reduce the earthquake input energy transmitted to the system. This technique is quite versatile and easily adjustable to different applications including seismic retrofit of buildings. Numerical analysis of some basic examples in this study shows desirable performances for a variety of applications.

A refined model for beam elements and beam–column joints

Abstract To improve the accuracy of finite element modeling of concrete frame structures, a new beam–solid transition element with refined characteristics is introduced. The refinement capability in this approach provides an accurate strain field approximation in the regions of high shear forces of beam and columns. Finite element formulation has been extended for material nonlinearity and large deformations to account for ultimate loads and secondary effects. In an example the accuracy and efficiency of this technique in analysis of beam–column joints is shown and the results compared with an alternative numerical approach.

Plant Type III PKS

This chapter covers recent advances in the chemistry and enzymology of the plant type III polyketide synthases (PKSs). The enzymes catalyze iterative decarboxylative condensations of malonyl unit (C–C bond formation reaction) with a CoA-linked starter molecule to produce structurally diverse, pharmaceutically important secondary metabolites. The functional diversity and catalytic potential of the plant type III PKSs are remarkable. Recent crystallographic and site-directed mutagenesis studies have revealed intimate structural details of the enzyme reactions, which enabled precursor-directed and structure-based engineered biosynthesis of unnatural polyketides.

GCMC simulations of dynamic structural change of Cu–organic crystals with N2 adsorption

N2 adsorption on Cu–organic crystals [Cu(bpy)2(BF4)2] (bpy = bipyridine) at 77 K begins suddenly at P/P 0 = 0.1. This unique adsorption is named gate adsorption. Gate adsorption is associated with the change of crystal structure from GCMC and dynamic GCMC simulations. An expansion of 10% opens internal pore spaces in the crystal, giving rise to gate adsorption. The complete filling of the internal spaces with N2 molecules induces an expansion of 30%.

Supercritical Hydrogen Adsorptivity of Amorphous Carbon Mesotubes

High-pressure adsorption isotherms of hydrogen onto amorphous carbon mesotubes (ACMs) prepared from fluorine polymer and onto activated carbon fibres (ACFs) were measured at temperatures of 77, 196 and 303 K, respectively, at pressures up to 10 MPa. The adsorption isotherms for ACMs and ACFs at 77 K exhibited maxima at 1 MPa (8.0 wt%) and 4 MPa (3.7 wt%), respectively, although both isotherms at 303 K were of the Henry type and both amounts of hydrogen adsorbed at 8 MPa were less than 0.3 wt%. The maximum hydrogen adsorption amount for ACMs per unit micropore volume as determined by N2 adsorption was 10-times larger than that for ACFs. ACMs are different from ACFs in that they are thought to have specific ultramicropores, although characterization using high-resolution transmission electron microscopy, X-ray photoelectron spectroscopy and Raman spectroscopy showed that they possessed a nanographitic structure similar to that of ACFs.

STRUCTURAL TEST OF PRECAST PRESTRESSED CONCRETE BEAMS USING LARGE DIAMETER PRESTRESSING STRANDS WITH PRETENSIONING SYSTEM

Precast prestressed concrete (PCaPC) beams with a pretensioning system are often used for constructing long-span reinforced concrete buildings. It is important to clarify the bond characteristics of the prestressing strands, because the concrete is prestressed through the bond between the strands and the surrounding concrete. A bond test and a loading test were carried out to clarify the bond characteristics and the structural performance of PCaPC beams using large diameter strands. As a result, the anchorage length of strands for prestressing and after large deformation, and the load-displacement relationship of the PCaPC beam under seismic loading were clarified. Based on these results, it is concluded that large diameter strands can be used as prestressing steel in PCaPC beams.

FEM Analysis of Interaction Effects of 3-D RC Members Subjected to Multi-Directional Cyclic Loading

Structural behavior of beam-column joints in a RC frame under seismic loadings differs from RC beam-column joints as subassemblies because neighboring members affect each other. The effects of beam’s eccentricities on the seismic performances of RC beam-column joints are investigated by 3-D nonlinear FEM Analysis. The verification of experimental results is conducted using FEM analysis. It is indicated that the torsion effects of beam-column joints caused by eccentricities is restrained more, if the contact area of slabs on the joint panel is larger.

SEISMIC PERFORMANCE EVALUATION OF BEAM-COLUMN JOINTS FOR PRESTRESSED RC BUILDINGS WITH HIGH PERFORMANCE MATERIALS

The testing of 4 one-third-scale prestressed reinforced concrete interior beam-column joints is detailed. The main parameters were the prestressing force and the bond condition between the grout and prestressing tendons passing through a joint. Prestressing force was applied at the ends of beams using the post-tensioning method. The beam-column joints were analyzed using a nonlinear finite element method (FEM); analysis was conducted by considering the bond between the grout and prestressing tendons as in the tests. All specimens failed in joint shear failure both in the tests and FEM analysis. FEM results show a good agreement with the test results on the maximum story shear forces and the failure mode. From the experimental and FEM results, the effects of the prestressing force and the bond condition between the grout and prestressing tendons on the joint shear capacity were examined. Conclusions are provided and discussed.

Intrauterine Chlamydia Trachomatis Infection in a Premature Infant

Intrauterine Chlamydia trachomatis infection was strongly suspected in a premature infant born in the 32nd week of gestation. The membranes were artificially ruptured at the time of delivery. This infant showed a high titer of specific IgM antibody to Chlamydia trachomatis at one hour after birth. He showed mild respiratory distress and was treated with oral erythromycin for three weeks. He was discharged home at the age of 46 days.