THREE-DIMENSIONAL FINITE ELEMENT ANALYSIS OF STRESS RESPONSE IN ADHESIVE BUTT JOINTS SUBJECTED TO IMPACT BENDING MOMENTS

The stress wave propagation and the stress distribution in adhesive butt joints of T-shaped similar adherends subjected to impact bending moments are calculated using a three-dimensional finite-element method (FEM). An impact bending moment is applied to a joint by dropping a weight. The FEM code employed is DYNA3D. The effects of the Young's modulus of adherends, the adhesive thickness, and the web length of T-shaped adherends on the stress wave propagation at the interfaces are examined. It is found that the highest stress occurs at the interfaces. In the case of T-shaped adherends, it is seen that the maximum principal stress at the interfaces increases as Young's modulus of the adherends increases. In the special case where the web length of T-shaped adherends equals the flange length, the maximum principal stress at the interfaces increases as Young's modulus of the adherends decreases. The maximum principal stress at the interfaces increases as the adherend thickness decreases. The characteristics of the T-shaped adhesive joints subjected to static bending moments are also examined by FEM and compared with those under impact bending moments. Furthermore, strain response of adhesive butt joints was measured using strain gauges. A fairly good agreement is observed between the numerical and the experimental results.     

Solvothermal syntheses of semiconductor photocatalysts of ultra-high activities

Thermal treatment of titanium(IV) butoxide dissolved in 2-butanol at 573 K under autogenous pressure (alcohothermal treatment) yielded microcrystalline anatase-type titanium(IV) oxide (TiO₂). Thermal treatment of oxobis(2,4-pentanedionato-O,O′)titanium (TiO(acac)₂) in ethylene glycol (EG) in the presence of sodium acetate and a small amount of water at 573 K yielded microcrystalline brookite-type TiO₂. Tungsten(VI) oxide (WO₃) powders of monoclinic crystal structure with high crystallinity were synthesized by hydrothermal treatment (HTT), at 523 or 573 K, of aqueous tungstic acid (H₂WO₄) solutions prepared from sodium tungstate by ion-exchange (IE) with a proton-type resin. Anatase and brookite TiO₂ products were calcined at various temperatures and then used for photocatalytic mineralization of acetic acid in aqueous solutions under aerated conditions and dehydrogenation of 2-propanol under deaerated conditions. Almost all the anatase-type TiO₂ samples showed the activities more than twice higher than those of representative active photocatalysts, Degussa P-25 and Ishihara ST-01 in both reactions. A brookite sample with improved crystallinity and sufficient surface area obtained by calcination at 973 K exhibited the hydrogen evolution rate almost equal to P-25. HTT WO₃ powders with various physical properties were used as photocatalyst for evolution of oxygen (O₂) from an aqueous silver sulfate solution. WO₃ powder of high crystallinity, e.g., IE-HTT-WO₃ synthesized at 573 K, gave much higher O₂ yield than commercially available WO₃ samples.     

Modeling nitrogen leaching from Andosols amended with different composted manures using LEACHM

Andosols, distributed widely around the Pacific basin, have unique soil–water and solute transport properties because of their stepwise water retention curves and high anion-adsorption capacity. The model modification and verification for these properties are crucial for evaluating the potential for improved agricultural management (e.g., using organic matter instead of inorganic fertilizer) to reduce N loss from the soils. Here, we improved an existing biogeochemical model, LEACHM, to predict long-term N leaching from Andosols amended with composted manure, without optimization to fit measured field data. The modified model was verified by observations from a 5.6-year lysimeter experiment with different rates of inorganic N fertilizer plus composted manure (100 + 0, 75 + 25, or 25 + 75%) of two different types (cattle, swine) on lettuce, sorghum (as a catch crop), and Chinese cabbage in rotation. Incorporation of Durner’s bimodal model dramatically improved predictions of drainage water volume and evapotranspiration. The non-linear Langmuir adsorption isotherms for soil NH₄ ⁺ and NO₃ ^? improved model performance in simulating crop N uptake and N leaching loss. The RMSE, R², and index of Agreement were evaluated as satisfactory in all lysimeters. Our model explained reasonably well that improved agricultural management decreased in current available N addition rates by 8.82–35.6% and reduced in the yearly averaged NO₃ leaching by 8.70–41.8%. A modified model relating soil hydraulic properties and N adsorption properties could thus accurately predict N leaching under different long-term N application rates/types, and could be useful for supporting agricultural management decisions in cropped Andosols.     

Advancing Small‐Molecule‐Based Chemical Biology with Next‐Generation Sequencing Technologies

Next‐generation‐sequencing (NGS) technologies enable us to obtain extensive information by deciphering millions of individual DNA sequencing reactions simultaneously. The new DNA‐sequencing strategies exceed their precursors in output by many orders of magnitude, resulting in a quantitative increase in valuable sequence information that could be harnessed for qualitative analysis. Sequencing on this scale has facilitated significant advances in diverse disciplines, ranging from the discovery, design, and evaluation of many small molecules and relevant biological mechanisms to maturation of personalized therapies. NGS technologies that have recently become affordable allow us to gain in‐depth insight into small‐molecule‐triggered biological phenomena and empower researchers to develop advanced versions of small molecules. In this review we focus on the overlooked implications of NGS technologies in chemical biology, with a special emphasis on small‐molecule development and screening.     

Transition to turbulent fluidization in a binary solids fluidized bed

This paper presents a study on the transition velocity from bubbling to turbulent fluidization in a binary solids fluidized bed. Experiments were carried out with two kinds of binary solids mixtures with FCC as fine particles and silica sands as coarse particles. The onset velocity to turbulent fluidization, U_c, determined by the measurement of pressure fluctuations, was found to increase with increasing the fraction of coarse/heavy solids. By introducing an equivalent particle diameter and an equivalent particle density, the results obtained in this study can properly be described by a general correlation of U_c proposed by Cai and co-workers (1989) for mono-density particles with relatively narrow size distribution.     

Preparation of Monodisperse Zirconia Particles by Thermal Hydrolysis in Highly Concentrated Solutions

Monodisperse zirconia particles were prepared by the thermal hydrolysis of mixtures of zirconyl chloride, zirconium hydroxide, and water at high concentrations corresponding to about 5 mol/L Zr. The particles, as first prepared, were temporarily agglomerated spheres composed of primary ultrafine zirconia crystals. The agglomerated particles collapsed and dispersed in water to form a translucent sol. When vacuum dried and followed by heat treatment, they were not dispersible. The size of the agglomerated particles increased with increasing molar ratio of the zirconium chloride in the starting mixture, varying from about 0.2 to 0.6 μm. Using the sample thus obtained, monodisperse tetragonal zirconia particles of about 0.35 μm containing 3 mol% Y₂O₃ with a relatively uniform composition were obtained by homogeneous precipitation of YOHCO₃ by heating with urea and calcination at 800°C.     

Molecular Mechanisms of Succinimide Formation from Aspartic Acid Residues Catalyzed by Two Water Molecules in the Aqueous Phase

Aspartic acid (Asp) residues are prone to nonenzymatic isomerization via a succinimide (Suc) intermediate. The formation of isomerized Asp residues is considered to be associated with various age-related diseases, such as cataracts and Alzheimer’s disease. In the present paper, we describe the reaction pathway of Suc residue formation from Asp residues catalyzed by two water molecules using the B3LYP/6-31+G(d,p) level of theory. Single-point energies were calculated using the MP2/6-311+G(d,p) level of theory. For these calculations, we used a model compound in which an Asp residue was capped with acetyl and methylamino groups on the N- and C-termini, respectively. In the aqueous phase, Suc residue formation from an Asp residue was roughly divided into three steps, namely, iminolization, cyclization, and dehydration, with the activation energy estimated to be 109 kJ mol⁻¹. Some optimized geometries and reaction modes in the aqueous phase were observed that differed from those in the gas phase.     

CTLA-4Ig Improves Hyperalgesia in a Mouse Model of Osteoporosis

This study aimed to evaluate skeletal pain associated with osteoporosis and to examine the inhibitory effects of cytotoxic T lymphocyte-associated antigen-4Ig (CTLA-4Ig) administration in ovariectomized (OVX) mice. Eight-week-old female ddY mice were assigned to three groups: sham-operated mice (SHAM) treated with vehicle, OVX mice treated with vehicle (OVX), and OVX mice treated with CTLA-4Ig (CTLA-4Ig). Vehicle or CTLA-4Ig was injected intraperitoneally, starting immediately after surgery. After 4 weeks of treatment, mechanical sensitivity was examined, and the bilateral hind limbs were removed and evaluated by micro-computed tomography, immunohistochemical analyses, and messenger RNA expression analysis. Ovariectomy induced bone loss and mechanical hyperalgesia in the hindlimbs. CTLA-4Ig treatment prevented bone loss in the hindlimbs compared to vehicle administration in the OVX group. Moreover, mechanical hyperalgesia was significantly decreased in the CTLA-4Ig treatment group in comparison to the OVX group. The expression levels of tumor necrosis factor-α (TNF-α) and sclerostin (SOST), as well as the number of osteoclasts, were increased, and the expression level of Wnt-10b was decreased in the OVX group compared with the SHAM group, whereas these parameters were improved in the CTLA-4Ig group compared with the OVX group. The novelty of this research is that CTLA-4Ig administration prevented bone loss and mechanical hyperalgesia induced by ovariectomy in the hindlimbs.     

Alkylation of benzene with ethane over platinum-loaded zeolite catalyst

Alkylation of benzene with ethane was carried out using various zeolite catalysts at temperature ranges of 400–550°C. Loading of platinum onto zeolite greatly enhanced the yield of ethylbenzene. Among the zeolites tested, H-ZSM5 and H-MCM22 showed catalytic activities. By contrast, mordenite did not yield ethylbenzene. Moderate acid strength distribution is the key factor of zeolite catalysts. Optimum catalyst and conditions for this reaction are as follows. The platinum-loaded H-ZSM5 catalyst containing 6.8 wt% Pt, at a reaction temperature of 500°C, afforded ethylbenzene and styrene formation rates of 14.2 and 0.8 mmolh^–1g-cat^–1, respectively (benzene-based yields 7.3 and 0.4%). In the alkylation of benzene with ethane over platinum-loaded H-ZSM5, ethene was initially formed from ethane over the metallic platinum. Then the alkylation proceeded over the acid sites of H-ZSM5.     

Operability of a thermally driven magnesium oxide/water chemical heat pump

The operability of a thermally driven chemical heat pump using the magnesium oxide/water reaction system was demonstrated experimentally. The heat pump system, consisting of a packed bed reactor and a water reservoir, was operated thermally with no mechanical work. The thermal output performance of the reactor bed was measured under pressures between SO and 202 kPa. The heat pump was expected to be applicable as a heat storage system for high efficiency energy utilization in cogeneration.