Synthesis of Ca3Sc2Si3O12:Ce3+ phosphor by hydrothermal Si alkoxide gelation

Single-phase Ca₃Sc₂Si₃O₁₂:Ce³⁺ green emission phosphor was synthesized by the hydrothermal silicon alkoxide gelation method. Such specimens demonstrated higher emission intensity than the Ca₃Sc₂Si₃O₁₂:Ce³⁺ samples that are prepared by conventional solid-state reaction method. It was also demonstrated that annealing in the presence of graphite as an oxygen scavenger significantly improves the fluorescence properties of this material.     

Fates of foodborne pathogens in raw hams manufactured rapidly using a new patented method

To manufacture raw ham in an efficient manner, we recently developed a new system in which presliced pork loin was used, and the processing time was reduced to 5% of the conventional method. This study aimed to examine whether this raw ham could be as safe as ham produced by the conventional method. Pork loin spiked with enterohemorrhagic Escherichia coli serotype O157:H7, Listeria monocytogenes serotype 1/2c, Salmonella enterica serovar Enteritidis, and Staphylococcus aureus were processed using either the new or conventional method. The fate of the foodborne pathogens and behavior of hygiene indicator bacteria were examined. Whereas nitrite had disappeared during the conventional packaging process, the reduced processing time in the new system allowed for the ham to be vacuum packed with retention of the nitrite (6.9±1.2 ppm, P<0.01). This accounts for the prominent decrease in L. monocytogenes (2.3 log reduction in 35 days) and S. aureus (3.3 log reduction in 13 days) counts during storage. E. coli O157 and Salmonella Enteritidis were likely resistant to the nitrite in the ham. However, they were unable to multiply in the ham and decreased gradually as in the conventionally produced ham. The bacteriostatic nature of the raw ham was also indicated by the gradual decrease in coliforms (1.3 log reduction in 13 days) in nonspiked ham. In conclusion, the raw ham produced using presliced pork loin is practically as safe as conventionally produced raw ham. It is worth validating these results in a small-scale production setting.     

Magnetic characteristics analysis of permanent magnet motor by using complex approximation taking account of two‐dimensional magnetic properties

This paper presents a complex E&S modeling approach, which is developed with a complex approximation for conventional E&S modeling. Complex E&S modeling is used to analyze a permanent magnet motor and the validity of complex E&S modeling is demonstrated. The computation time of complex E&S modeling can be considerably reduced in comparison with conventional E&S modeling. © 2012 Wiley Periodicals, Inc. Electr Eng Jpn, 180(2): 9–16, 2012; Published online in Wiley Online Library (wileyonlinelibrary.com). DOI 10.1002/eej.21268     

Distribution on localized two‐dimensional magnetic properties of three‐phase induction motor core

Improving material characteristics and optimizing technical designs have been studied from the standpoint of efficiency improvement of electrical machinery and apparatus. Unfortunately, the local magnetic properties in actual cores are still not understood fully. On the other hand, there is understanding of the two‐dimensional magnetic property, that is, the relationship between the magnetic field strength vector H and the magnetic flux density vector B , which are not usually parallel but have a phase angle. Therefore, local magnetic properties in an actual constructed core should be measured as a vector relation. This paper presents the local magnetic properties in a three‐phase induction motor model core, which are measured with a two‐dimensional measurement sensor. © 2000 Scripta Technica, Electr Eng Jpn, 133(4): 34–40, 2000     

Transition between Condensing and Air Flow Drying of Thin-Film Coatings

The transport characteristics were investigated in the bench-top condenser dryer, which is a new and air-free drying system for advanced coating applications. The measured solvent drying rate agrees with the one-dimensional diffusion theory in the early drying stages, showing the validity of the previously proposed diffusion models in a quantitative sense. The combination of the condenser dryer with the air flow system revealed a characteristic transition in the diffusion kinetics between the convection-drying and the condensing-drying regimes. The drying of immiscible ternary solution coatings showed a transition in the phase-separated morphologies from the isolated droplets to the elongated stripe patterns.     

Preparation of aminoalkyl celluloses and their adsorption and desorption of heavy metal ions

Aminoalkyl celluloses (AmACs) were prepared from 6-chlorodeoxycellulose and aliphatic diamines H₂N(CH₂)_mNH₂ (m = 2, 4, 6, 8). Their adsorption and desorption of divalent heavy metal ions such as Cu²⁺, Mn²⁺, Co²⁺, Ni²⁺ and their mixtures were also investigated in detail. Adsorption of metal ions on AmACs was remarkably affected by the pH of the solution, the metal ion and its initial concentration, and also the number of methylene units in the diamines. No adsorption of metal ions occurred on AmACs in strongly acidic solutions. However, metal ions were adsorbed rapidly on AmACs from weakly acidic solutions and the amount of adsorption increased with increasing pH. The effectiveness of AmACs as adsorbents decreased with increasing length of the methylene moiety, and AmACs from ethylenediamine (m = 2) was most effective. The adsorption of metal ions on AmACs was in the order Cu²⁺ > Ni²⁺ > Co²⁺ > Mn²⁺. Accordingly, their behavior followed the Irving-Williams series and Cu²⁺ ions were preferentially adsorbed from solutions containing metal ion mixtures. The adsorbed ions were easily desorbed from the AmACs by stirring in 0.1 M HCl.     

Photocatalytic decomposition of NO on titanium oxide thin film photocatalysts prepared by an ionized cluster beam technique

Transparent TiO₂ thin film photocatalysts were prepared on transparent porous Vycor glass (PVG) by an ionized cluster beam (ICB) method. The UV‐VIS absorption spectra of these films show specific interference fringes, indicating that uniform and transparent TiO₂ thin films are formed. The results of XRD measurements indicate that these TiO₂ thin films consist of both anatase and rutile structures. UV light (λ > 270 nm) irradiation of these TiO₂ thin films in the presence of NO led to the photocatalytic decomposition of NO into N₂, O₂ and N₂O. The reactivity of these TiO₂ thin films for the photocatalytic decomposition of NO is strongly dependent on the film thickness, i.e., the thinner the TiO₂ thin films, the higher the reactivity. This revised version was published online in July 2006 with corrections to the Cover Date.     

A unique phase behavior of random copolymer of N-isopropylacrylamide and N,N-diethylacrylamide in water

Thermosensitive phase separation of aqueous solutions of the random copolymers of N-isopropylacrylamide (iPA) and N,N-diethylacrylamide (dEA) (PiPA-dEA) and of iPA and N-isopropylmethacrylamide(iPMA) (PiPA-iPMA) with different compositions has been investigated by using calorimetry, turbidimetry and infrared spectroscopy. Though the phase transition temperature (T_p) of PiPA-iPMA is a linear function of its composition, a deviation from additivity is observed for that of PiPA-dEA, that is, it has a minimum value at iPA/dEA = 1 (mol/mol). IR spectrum at the amide II mode of the copolymer suggests that part of N-H groups of iPA units form a hydrogen bond with CO groups of dEA units at T > T_p as well as with those of the iPA units. Effects of methanol on T_p of these copolymers have also been studied.     

Layered liquid-liquid flow in microchannels having selectively modified hydrophilic and hydrophobic walls

When two immiscible liquids make contact in a microchannel, the flow pattern is affected by the affinity between channel walls and liquids. In this study, microchannels (200 μm in width and 200 μm in depth) having a T-shaped bifurcation point were fabricated on PMMA plates. The inner walls of the microchannels were modified in a zone-selective manner to be either hydrophilic or hydrophobic, based on verification accomplished via a laser interference fringe technique. The microchannel was placed horizontally, and water and octane were introduced into the upper-side channel (hydrophilic) and into the lower-side channel (hydrophobic), respectively. The experimental results showed that water and octane formed a stable layered flow, and the two liquids were virtually completely separated at the T-shaped section, even when static pressure was intentionally applied to the outlets. CFD simulation, using FLUENT 6.3 software, was performed to explain the role of zone-selective modification of microchannel walls.     

Microencapsulation of hydrophilic solid powder as fire retardant agent with epoxy resin by droplet coalescence method

To give water resistance to Bistetrazol–diammonium (BHT–2NH₃) as a fire retardant agent, microencapsulation with epoxy resin was tried by the droplet coalescence method. In this method, two kinds of epoxy resin droplets were prepared; one is the larger epoxy resin droplet containing BHT–2NH₃ as a core material and the other the smaller droplets containing Imidazole as a gelation agent. The larger epoxy resin droplets were made to coalesce with the many smaller droplets during the microencapsulation process to prepare microcapsules. In the experiment, the agitation velocities for preparation of the droplets and for coalescence were mainly changed. With increase in the impeller speed, the content of core material increased, became maximum because of increase in the coalescence frequency, and then decreased because of breakup of droplets. With increase in the impeller speed, the leakage ratio of core material decreased, became minimum, and then increased. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008.