Morphology and photophysical properties of polymer thin films dispersed with dye nanoparticle

We prepared nanoparticles of an organic dye, acridine orange (AO), dispersed in poly(methacrylic acid) (PMA) films by spin-coating the solution of the two components. The surface of the AO/PMA films became bumpier with increasing AO concentration (c_AO). The absorption and fluorescence spectra of AO/PMA films exhibited a marked dependence on c_AO at low c_AO (c_AO < 2.1 × 10^− 1 mol kg^− 1), and were independent of c_AO at high c_AO (c_AO > 2.1 × 10^− 1 mol kg^− 1). The peak shift of fluorescence spectra with changing c_AO was as large as ∼ 100 nm.     

Development of Adsorption Steam Generator without the Fossil Fuels Consumption

Reducing CO2 emissions and restraining dependence on nuclear power generation are serious concerns in the prevention of global warming since the Great East Japan Earthquake. To do so, it is necessary to use and expand natural renewable energy source such as solar energy and to promote energy conservation. However, in high-latitude regions, it is difficult to directly and effectively use solar power due to on insufficient amount of solar radiation. If steam can be generated from warm water at less than 373 K, it is possible to obtain steam by solar water heaters from weak solar radiation and industrial waste warm water without the consumption of any fossil fuels. In this study, the authors have been developing a system which generates steam over 423 K from warm water at less than 373 K using an adsorption heat pump with zeolite. Therefore, bench-scale equipment which generates steam continuously and the experimental results are mentioned.     

Recent R&D on Drying Technology in Japan

This article presents the outlook of the energy situation in Japan and reviews the recent R&D on innovative drying technologies performed in Japan. The overview of drying includes fundamentals as well as industrial technologies. The topics considered are drying characteristics of several materials, drying of hard-to-handle powders, drying of coatings, drying-induced strain-stress problems, drying modeling, and drying of agricultural wastes for functional recycling and noble dryers. An appropriate combination of heating methods and dryer type can result in significant enhancement of efficiency, drying rate, and/or material quality. The final goal of this article to contribute to providing an idea for development and evaluation of precise drying systems with a high performance and an effect of energy saving in drying.     

1.55 ?m narrow-linewidth multielectrode DFB laser for coherent FSK transmission

A 1.55?m multielectrode DFB laser, with both flat FM response characteristic and spectral linewidth as narrow as 4.5 MHz, has been fabricated by an MOVPE/LPE hybrid growth method. Since this device is relatively easy to fabricate, the multielectrode DFB laser is most promising as a coherent FSK transmission light source     

Anesthetic management of two patients with mitochondrial encephalopathy, lactic acidosis and stroke-like episodes (MELAS)

MELAS is a type of the mitochondrial myopathy characterized by elevation of pyruvate and lactate levels in both the blood and cerebrospinal fluid. This syndrome frequently accompanies cerebral infarction like symptoms. Recently, we experienced two patients for anesthesia with MELAS (both 11-year-old girls). V-P shunt construction and IVH reservoir implantation were conducted, respectively. Anesthesia was induced with fentanyl and midazolam, and vecuronium was used to facilitate tracheal intubation. Volatile anesthetic was avoided, and anesthesia was maintained with fentanyl, midazolam, and nitrous oxide. Arterial blood gases and pH were frequently checked, and acetated electrolyte solution was infused mainly during surgery. No complications occurred during anesthesia in both patients. In the anesthetic management for MELAS, measures to prevent malignant hyperthermia must also be considered.     

Operon structure optimization by random self-assembly

Synthetic biology is an emerging research area that aims to investigate natural biological phenomena and reconstruct complex artificial biological systems. Recent development of genetic engineering such as multiple gene assembly method accelerates the synthetic biology study. Ordered gene assembly in Bacillus subtilis (OGAB method) is to assemble multiple genes in one step using an intrinsic B. subtilis plasmid transformation system and enables to reconstitute sets of relevant genes. The OGAB method assembles multiple DNA fragments with a fixed order and orientation and constructs an operon structure in a resultant plasmid. However, the optimal order and orientation to reconstitute a set of genes are generally not trivial and depends on several factors in host bacteria, where the “optimal” means the efficiency of biosynthesis induced by transferred genes in a metabolic pathway. We propose a method to apply self-assembly technique to optimization problem of operon structure. Self-assembly of multiple genes generates all possible orders of genes on operon structure. The number of generated orders on operon structure becomes the factorial of the number of multiple genes. All generated orders of multiple genes are then introduced into E. coli cells and most prominent colony for biosynthesis is extracted. We show some preliminary experiment to construct more efficient orders for five genes in the carotenoid biosynthetic pathway, and found a new order that is more efficient than previous studies for gene order.     

Dry gas cleaning process by adsorption of H2S into activated cokes in gasification of carbon resources

Gasification of carbon resources including biomass and coal is one of promising energy production technologies. The R&D on effective and convenient gas cleaning processes for removal of contaminants as well as high efficient reliable gasifiers is essential for industrial application in broad fields. In this study, a dry process of synthesis gas cleaning by adsorption of H₂S into activated cokes was proposed as a candidate of desulfurization technologies in gasification. The H₂S adsorption performance of activated coke produced from coal, which are used industrially for de-SO_x and de-NO_x, was evaluated by the thermogravimetric analyses and the adsorption examination in a fixed bed under the atmospheric and high pressures. Activated coke was not only the most active at about 423 K for the H₂S adsorption rate but also regenerative over 573 K by H₂S desorption with a sufficient rate under an inert gas flow of nitrogen. The H₂S adsorption performance of the activated coke was not inhibited by the co-existence of CO₂ or COS but enhanced rather by the co-existence. The adsorbent was promisingly active for both H₂S and COS adsorption as well. These behaviors suggest that the activated coke are available for simultaneous desulfurization of H₂S and COS. The H₂S breakthrough examination in the fixed bed revealed that it was possible to remove H₂S to lower level than 1 ppm for a long time depending on the residence time of gas flow in the bed. When the adsorption operation was carried out under high pressures up to 0.6 MPa, the regeneration of activated coke by H₂S desorption took place under the pressure reduced to the atmosphere. As the results, it was implied that the present activated coke could be applicable to the desulfurization process in coal gasification.     

AFM observation of silk fibroin on mica substrates: morphologies reflecting the secondary structures

Bombyx mori silk fibroin was fixed on mica substrates by cast of aqueous fibroin solutions, and the microscopic morphologies of the samples were revealed by means of atomic force microscopy. By adjusting the method used to prepare the solution, we succeeded in forming quasi-2-dimensional thin films in which a network of fibroin molecules developed over the substrate. The film network consisted of fibroin in a random coil structure. The morphology of the network changed after thermal or methanol treatments, which are known to convert the secondary structure of fibroin from the random coil to the β-sheet type. In both of these cases, the network morphology disappeared and characteristic island-like morphologies appeared. On the other hand, temporally evolving gelation occurred in a fibroin solution due to the formation of β-sheet crystals. Such islands were also observable in a specimen prepared by the cast of the gel-containing solution. Based on these results, it was concluded that the islands consist of β-sheet crystals. Of particular interest is the observation that all of the islands had a common thickness value of 1.3 nm. These morphologies are discussed in terms of the secondary structure of fibroin.     

- VISCOELASTIC STRAIN-STRESS AND HEAT/MOISTURE TRANSFER -

The theoretical analysis was developed to predict the deformation characteristic of formed clay during a drying process in a ceramic production. The three dimensional strain-stress distribution as well as heat and moisture transfer in a slab shape of clay were simultaneously analyzed by a finite element method. Linear viscoelasticity was assumed for the strain-stress analysis to account the effect of creep. The calculated result agreed well with an experimental result performed for a slab clay heated by hot air flow during the preheating and constant drying rate periods. A large tensional stress, which may generate a crack, was observed initially around the surface area. It was also found that the time behavior of the volume change of the formed clay is significantly influenced on the drying conditions and/or the drying rate.