Schmelzlinienbestimmungsmodell zur vergleichenden Leistungsbeurteilung von Hochofenperioden

Vergleich von Hochofenbetriebsergebnissen mittels Leistungs-Faktor-Definition. Bestimmung der Lage und Form der Schmelzlinie im Hochofen durch Betriebsdaten. Wärmeeinbringen durch Blasform und deren Übertragung durch Konvektion und Strahlung. Einfluß der Wärmebedingungen im Unterofen auf die Lage der Schmelzlinie. Vergleich und Überprüfung der Modellprofile durch Betriebsmessungen. Einfluß verschiedener Unterofenparameter auf Hochofenbetrieb und Schmelzlinie. Schmelzgeschwindigkeit bei W- und ∧-Profilen in Abhängigkeit der Strahlungstemperatur. Untere kritische Höhenlage der Schmelzlinie und dynamisches Verhalten der Schmelzlinie.     

Polymer film-type channel electron multipliers: Their characteristics and comparison with bulk-type flexible multipliers

Polymer film-type channel electron multipliers (CEMs) were developed and their characteristics investigated in comparison with bulk-type flexible CEM. As film-type CEMs, a paint-coating-type CEM and a solvent-etching-type CEM were fabricated. The paint-coating-type CEM is made by coating a “paint” which is prepared by dissolving in a solvent an electronically conductive polymeric composition having a high secondary electron emission yield. Up to the present study the mean gain of the film-type CEM, in spite of the lower resistivity of the dynode, seems to be slightly more dependent on the count rate than that of the bulk-type CEM made of the same material. However, the convenience of fabricating the dynode film by coating the dynode-forming paint on the internal surface of any shaped tube or a flexible polymer tube would overcome the slight disadvantage mentioned above.     

Volatilization and recovery of mercury from mercury wastewater produced in the course of laboratory work using Acidithiobacillus ferrooxidans SUG 2-2 cells

The iron-oxidizing bacterium Acidithiobacillus ferrooxidans SUG 2-2 is markedly resistant to mercuric chloride and can volatilize mercury (Hg0) from mercuric ion (Hg2+) under acidic conditions. To develop a microbial technique to volatilize and recover mercury from acidic and organic compound-containing mercury wastewater, which is usually produced in the course of everyday laboratory work in Okayama University, the effects of organic and inorganic chemicals on the mercury volatilization activity of A. ferrooxidans cells were studied. Among 55 chemicals tested, the mercury volatilization from a reaction mixture (pH 2.5) containing resting cells of SUG 2-2 (1 mg of protein) and mercury chloride (14 nmol) was strongly inhibited by AgNO3 (0.05 mM), K2CrO7 (1.0 mM), cysteine (1.0 mM), trichloroethylene (1 microM), and commercially produced detergents (0.05%). However, the strong inhibition by trichloroethylene and detergents was not observed when these organic compounds were chemically decomposed using Fenton's method before the treatment of the wastewater with SUG 2-2 cells. When 20 ml of water acidified with sulfuric acid (pH 2.5) containing ferrous sulfate (3%), diluted mercury wastewater (17.5 nmol of Hg2+) and SUG 2-2 cells (0.05 mg of protein) were incubated for 10 d at 30 degrees C, 47% of the total mercury in the wastewater was volatilized and recovered into a trapping reagent for metal mercury. However, when the organic compounds in the mercury wastewater were decomposed using Fenton's method and then treated with A. ferrooxidans cells, approximately 100% of the total mercury in the wastewater was volatilized and recovered.     

Gene expression within cell-sized lipid vesicles

Functional protein synthesis was observed in cell-sized lipid vesicles following encapsulation of a gene-expression system. Expression of rsGFP (red-shifted green fluorescent protein) within individual vesicles was observed by fluorescence microscopy. Interestingly, at the early stage of the reaction, the expression efficiency inside the vesicle was remarkably higher than that in the solution outside. The synthesized rsGFP in individual vesicles is safe from attack by proteinase K added to the external aqueous solution. Studies on cell-sized vesicles expressing protein should contribute to a fundamental understanding of certain aspects of living systems and will be useful for practical applications, such as the construction of microreactors.     

Computer-aided design of a factor Xa inhibitor by using MCSS functionality maps and a CAVEAT linker search

We have investigated a new approach to efficiently find a novel inhibitor against a serine protease (i.e. an activated coagulation factor X, FXa) by using de novo design programs and the X-ray crystal structure of the target enzyme. FXa is a coagulant enzyme that generates thrombin (a serine protease) and participates in both intrinsic and extrinsic coagulation pathways. We adopted multiple copy simultaneous search (MCSS) and CAVEAT linker search techniques, which disclosed a novel FXa inhibitor (T01312) consisting of two binding moieties (the benzamidinyl and adamantyl groups) and a linker unit (the carboxybenzylamine group). The inhibitory activity of T01312 against FXa was determined to be a small K(i)-value of 48nM, which is two orders of magnitude smaller than that against thrombin. An X-ray crystal analysis of T01312 complexed with trypsin (an analogue of FXa) and docking studies of T01312 with trypsin and FXa showed that: (i) the benzamidinyl group is a predominant binding moiety in the anionic pocket (S1 site) with an asparatic acid residue; (ii) a hydrophobic pocket (S4 site) is the binding site of the adamantyl group; (iii) the carboxylate group of the linker contributes to the selectivity for FXa against thrombin. Thus, the combination of the knowledge of the X-ray crystal structure of the target molecule with MCSS and CAVEAT linker search techniques proved to be an effective hit-finding method that does not require the screening of huge compound libraries.     

Three-Dimensional Numerical Simulation of Helically Propagating Combustion Waves

In the present paper, by using a mathematical model for self-propagating high-temperature synthesis, we reveal the three-dimensional structure of so-called spin combustion wave on the inside of cylindrical sample. It is shown that an isothermal surface of regular spin combustion wave has some wings of which number is the same as that of reaction spots on the cylindrical surface and that the isothermal surface with helical wings rotates down with time. Because of this propagating pattern, in this paper, we adopt the more suitable term helical wave. We also obtain the following existence conditions of a helical wave: If physical parameters are set so that a pulsating wave exists stably for the one-dimensional problem, then a helical wave takes the place of a pulsating wave when the radius of cylindrical sample becomes large.     

Intermetallic compound formation between lead-free solders (Sn) and Cu or Ni electrodes

A kinetic model based on the principle of maximum degradation rate of the total system free energy, MDR law using thermodynamic data, is proposed and successfully applied to the selection of the first intermetallic compound (IMC) phase in Cu/Sn and Ni/Sn diffusion couples. The first phases predicted with this model for Cu/Sn and Ni/Sn are Cu₆Sn₅ and Ni₃Sn₄, respectively, resulting in good agreement with experimental observations.     

Analytical Model for Redistribution Profile of Ion-Implanted Impurities During Solid-Phase Epitaxy

We evaluated the redistribution profiles of ion-implanted impurities during solid-phase epitaxy using Rutherford backscattering spectrometry (RBS). RBS data revealed that the As concentration changes only near the moving amorphous/crystal interface. We derived an analytical model for the redistribution profiles using a segregation coefficient m between amorphous and crystalline Si, introduced a parameter of reaction length l that is the distance where impurities were exchanged, and obtained good agreement with experimental data with an m value of 3 and an l value of 1 nm for As. Furthermore, we applied our model to P and B redistribution profiles and obtained good agreement with corresponding m value of 4 and l value of 1 nm for P and m value of 0.3 and l value of 1 nm for B     

PREPARATION AND PERMEABILITY CONTROL OF ELECTRO-SENSITIVE MICROCAPSULES WITH IMMOBILIZED FERROELECTRIC LIQUID CRYSTALLINE SEGMENTS

Nylon-polystyrene microcapsules with immobilized ferroelectric liquid crystalline segments were prepared, and the permeability control of the encapsulated core material was investigated under an external electric field. A ferroelectric liquid crystal monomer possessing both mesogenicity and chirality effectively responded to an external electrical field. Permeation of the material (oxprenolol) contained in the inner aqueous core of the microcapsules was enhanced under a feeble electric field (2 V). Furthermore, it was found that the permeability of the microcapsules without the ferroelectric liquid crystal group did not depend on the external electrical field. In order to clarify the controlled release mechanism of the core material, the transmittance was quantitatively evaluated under an external electric field using a handmade polarized light transmittance apparatus.