Heat transfer characteristics of the latent heat thermal energy storage capsule

The characteristic variation of the rate of heat transfer to and from a latent heat thermal energy storage capsule was investigated analytically and experimentally. Basic experiments were carried out to simulate a solar energy storage capsule, using a horizontal cylindrical capsule (300 mm length, 40 mm o.d.) filled with naphthalene as the phase change material. The variation of heat flux during the processes of heat storage and removal was measured by a heat flow meter wrapped around the capsule, as the capsule was subjected to stepwise variations of the surface temperature. Finite difference calculations based on heat conduction were also carried out to compare with the experimental results. For the heat removal process, the experimental results and the calculated heat flux agreed well with each other. They showed different characteristic trends for the heat storage process, due to the effects of natural convection.     

Chemical erosion and sputtering of solid surfaces with liquid cluster ions

The sputtering phenomena of solid surfaces such as Si(111) and SiO₂ surfaces were investigated using ethanol and water cluster ion beams. To be compared with Ar monomer ion irradiation, the sputtering yield of Si surfaces was approximately 100 times higher for ethanol cluster ion irradiation and approximately 10 times higher for water cluster ion irradiation. Furthermore, for the ethanol cluster ion irradiation, chemical erosion such as silicon hydride and hydro-carbide reaction occurred on the Si surface, which resulted in the high-rate sputtering of the surface. On the other hand, for the water cluster ion irradiation, oxidation occurred on the Si surface, and physical sputtering was performed on the surface. Based on these results, chemical reaction at a nano-scale area on the Si(111) surfaces was discussed from the thermodynamic approach, and the impact of cluster ions on the surface exhibited high temperature such as a few tens of thousands degrees, which resulted in the enhancement of the chemical reaction. Thus, liquid cluster ion irradiation exhibited unique erosion and sputtering even at room temperature, which were not obtained by a conventional wet process.     

One‐Pot Olefin Isomerization/Aliphatic Enamine Ring‐Closing Metathesis/Oxidation/1,3‐Dipolar Cycloaddition for the Synthesis of Isoindolo[1,2‐a]isoquinolines

N‐Alkyl‐N‐(2‐vinylbenzyl)prop‐2‐en‐1‐amine derivatives undergo a one‐pot olefin isomerization/aliphatic enamine ring‐closing metathesis (RCM)/oxidation/1,3‐dipolar cycloaddition sequence with the ruthenium complex, Ru(CO)HCl(PPh₃)₃, a second generation Hoveyda–Grubbs catalyst, and a 1,3‐dipolarophile. Overall, in a single operation the reaction sequence converts simple benzylamine derivatives into isoindolo[1,2‐a]isoquinolines with a π‐conjugated four‐ring system, through three unique ruthenium‐catalyzed transformations.

     

Synthesis of poly(methyl methacrylate)-silica nanocomposites using methacrylate-functionalized silica nanoparticles and RAFT polymerization

Well-defined poly(methyl methacrylate)-silica nanocomposites were produced by “grafting through” using reversible addition-fragmentation chain transfer (RAFT) polymerization. The surface of silica nanoparticle was modified covalently by attaching methacryl group to the surface using 3-methacryloxypropyldimethylchlorosilane. Polymerization of methyl methacrylate (MMA) using the 4-cyano-4-(dodecylsulfanylthiocarbonyl)sulfanyl pentanoic acid RAFT agent, produced the PMMA-SiO₂ nanocomposites. Characterization of these well-defined nanocomposites included FT-IR, gel permeation chromatography (GPC), thermogravimetric analysis (TGA), differential scanning calorimeter (DSC), transmission electron microscopy (TEM) and dynamic mechanical analysis. These results show that the T_g values are higher and the mechanical strength of the PMMA-SiO₂ nanocomposites is slightly improved when compared to bulk PMMA. Further, the molecular weight of the PMMA (up to M_n = 100,000) is controlled and the SiO₂ are well dispersed in the PMMA matrix.     

Production of recombinant human lysosomal acid lipase in Schizosaccharomyces pombe: development of a fed-batch fermentation and purification process

A fed-batch fermentation process has been developed to enable the production of large quantities of recombinant human lysosomal acid lipase (hLAL; EC 3.1.1.13), in Schizosaccharomyces pombe, for preclinical studies as a potential enzyme therapy drug. Recombinant S. pombe, clone ASP397-21, expressed enzymatically active hLAL in the secreted form. A feedback fed-batch system was used to determine the optimal feed rate of a 50% glucose solution used as the carbon source. The feed rate of the glucose solution was calculated by a computer-aided system according to the equation; F=q(sf)(VX)/S(in) (q(sf), specific substrate feed rate [gram substrate/gram dry cell weight/h]; V, volume of culture broth [l]; X, cell density [gram dry cell weight/l]; S(in), concentration of growth limiting substrate in feed solution [gram substrate/gram feed solution]). At the time of the initial consumption of glucose in the batch-phase culture, the nutrient supply was automatically initiated by means of monitoring the respiratory quotient change. The obtained profile of the feed rate was applied to the feed forward control fermentation. Finally, the cells were grown up to >50 g dry cell weight/l, and the hLAL expression level was approximately 16,000 U/l. Expressed hLAL protein was purified in a two-step process by hydrophobic interaction and anion exchange chromatographies. Purified recombinant hLAL exhibited a 90-150 kDa broad band upon SDS-PAGE with specific activity of about 300 U/mg. After endoglycosidase H treatment, the band converged to 45 kDa, equal to the calculated molecular weight, suggesting that hLAL produced in S. pombe was hyper-glycosylated. N-terminal analysis of de-glycosylated hLAL revealed that the signal sequence of hLAL was correctly processed in S. pombe.     

Kluyveromyces marxianus-based platform for direct ethanol fermentation and recovery from cellulosic materials under air-ventilated conditions

Consolidated bioprocessing represents an attractive approach to converting cellulosic materials into bioethanol, yet is practically unavailable. We developed a ventilation-mediated, simultaneous ethanol fermentation and recovery system. Running the system under air-supplied conditions, apparently pure ethanol (28g) was recovered from cellobiose (100g) by growing recombinant Kluyveromyces marxianus expressing β-glucosidase.     

EFFECT OF DRYING ON POWDER COATING EFFICIENCY AND AGGLOMERATION IN VIBRO-FLUIDIZED BED

Glass beads of 43 μm were coated in a vibro-fluidized bed by atomizing a fine silica powder together with polyvinyl alcohol aqueous solution. The coating efficiency and weight fraction of the agglomerated particles were measured under various experimental conditions, and their dependencies on the frequency and the direction of vibration were investigated. The coating efficiency and the degree of the agglomeration among core particles correlated well with an index R. The index R was introduced to evaluate quantitatively the drying conditions in a fluidized bed.

Application of vertical vibration on the fluidized bed lowered the coating efficiency somewhat, while it prevented agglomeration. From the experimental results it was confirmed that coating with high quality and high efficiency, where few agglomerates were produced and silica powder was utilized efficiently, was possible in a vibro-fluidized bed with adequate vibration frequency and orientation of the vibration vector.     

Experimental and theoretical analyses on power generation characteristics of co-axial MHD energy conversion device

Experiments on power generation were conducted under the open-circuit condition to validate theoretical analyses on the power generation characteristics of a co-axial MHD energy conversion device. Considering distribution of externally applied magnetic field and the electromotive force induced by the rotation of the conductive inner cylinder, the results show that the experimental open-circuit voltage was lower than the theoretical one for the wide channel width, whereas the experimental open-circuit voltage was higher than the theoretical one for the narrow channel width. The inclination of the inner cylinder might cause the decrease in effective radial ratio.