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Process industry remains skeptical of the effect of scale prevention in a water pipe by magnetic treatment despite its long history. In this study, mechanism of scale prevention by “alternating” magnetic treatment was investigated. Using suspensions of non-magnetic colloid particles (TiO2 or CaCO3) dispersed in an electrolytic solution, we investigated zeta potential changes of the particles by imposition of alternating magnetic field with a specific frequency. Consequently, we found that the specific frequency treatment (several kHz) changes the zeta potential of particles drastically with an inversion of sign. This phenomenon obviously depends on the frequency. It is considered to be due to the specific adsorption of anions, that were easily adsorbed, in the solution onto the particles interface. From the experimental results, we concluded the mechanism of scale prevention by the treatment as follows: Normally, a surface of inner wall of a water pipe has negative charge and surface of scale particles in water has positive charge. So the particles are attracted by the water pipe and are attached to it. After the treatment, surface potential of the particles shifts to negative side, then repulsive force is formed between the particles and the wall. © 2007 American Institute of Physics [ABSTRACT FROM AUTHOR]

The development of carbon nanotubes (CNTs) for tissue engineering and regenerative medicine has attracted a great deal of attention. Multi-walled carbon nanotube (MWCNT) scaffolds have been used for the successful proliferation of osteoblasts. In this study, osteoblast cells were cultured on prepared scaffolds in vitro and the characteristics of each scaffold were evaluated in an effort to investigate the effect of surface properties such as roughness and the adsorption of albumin on MWCNT scaffolds with different diameters. © 2007 American Institute of Physics [ABSTRACT FROM AUTHOR]

An investigation was carried out to improve the production of acetic acid by an alkaline two-step process, in which the first step is to accelerate the formation of lactic acid in a hydrothermal reaction with the addition of alkali, and the second step is further convert the lactic acid produced in the first step to acetic acid by oxidation with newly added oxygen. Results showed that the addition of alkali promoted selectively the formation of lactic acid from glucose at a hydrothermal condition. Acetic acid yield in the alkaline two-step process greatly increased in comparison to that without the addition of any alkali. In the alkaline two-step process, the highest acetic acid yield arrived at 27 % on the carbon base under the conditions of reaction temperature of 300 °C, reaction time of 1 min, and Ca(OH)2 concentration of 0.32 M in the first step, and reaction temperature of 300 °C, reaction time of 3 min, and oxygen supply of 70 % in the second step. © 2007 American Institute of Physics [ABSTRACT FROM AUTHOR]

ZnS shows high photocatalytic activity, nevertheless the operating wavelength is limited to less than 330 nm. On the other hand, CdS can be used at wavelength up to 512 nm. However, CdS requires Pt as supporting catalyst. We have synthesized Pt-free ZnxCd1-xS particles with x varying between 0 and 1 by co-precipitation method and evaluated their photocatalytic activities. The highest photocatalytic activity was recorded for Zn0.67Cd0.33S particles. Then, ZnxCd1-xS solid solution films were prepared using the above particles by dip-coating method and their photocatalytic activities were evaluated. © 2006 American Institute of Physics [ABSTRACT FROM AUTHOR]

Cadmium Sulfide semiconductor has comparatively small band gap and act as photocatalyst under irradiation of visible light. For practical use, it is convenient to fix the photocatalyst on a substrate as a thin film. In this study, we prepared CdS thin film on Ti substrate by Chemical Bath Deposition (CBD). To improve photocatalytic activity, CdS film was annealed and optimum thickness was investigated. © 2006 American Institute of Physics [ABSTRACT FROM AUTHOR]

Hydrothermal degradation of glucose in the presence of HCl, H2SO4 and H3PO4 were carried out with pH varying from 1.5–2.5, reaction time varying from 1 min to 10 min at 523 K, to investigate the effect of different acid catalysts and acid concentration on the production of 5-hydroxymethyl-2-furaldehyde (HMF) and levulinic acid from glucose. At lower acid concentration, the yield of HMF was considerably high. The increase in acid concentration accelerated the conversion of HMF to levulinic acid. Among three acid catalysts, HCl is most effect for both conversion of glucose to HMF and further conversion of HMF into levulinic acid. But the decomposition of HMF is also fastest in the case of HCl catalysis. In the conditions used in this study, the highest yield of levulinic acid is about 55 %, which occurred at pH 1.5 for 5 min with HCl, and total highest yield of HMF and levulinic acid is about 50 %, which occurred at pH 2.0 for 5 min with H3PO4. © 2007 American Institute of Physics [ABSTRACT FROM AUTHOR]