Adsorption of an Anionic Surfactant (Sodium Dodecyl Sulfate) from an Aqueous Solution by Modified Cellulose with Quaternary Ammonium.

In this study, a method of removing an anionic surfactant sodium dodecyl sulfate (SDS) from an aqueous solution by cellulose modified with quaternary ammonium cation was discussed. Cellulose, as the adsorbent, was obtained from medical cotton balls, and the quaternary ammonium cation (synthesized from dodecyl dimethyl tertiary amine and epichlorohydrin) was grafted onto the sixth hydroxyl group of D-glucose in the cellulose by the Williamson reaction under alkaline conditions. The modified cellulose was characterized by Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), and X-ray photoelectron spectroscopy (XPS); and the zeta potential of the material was also measured after confirmation of the synthesis of quaternary ammonium salts by nuclear magnetic resonance (NMR). From these analyses, a peak of the quaternary ammonium group was observed at 1637 cm-1; and it was found that the surface of the material exhibited a positive charge in pH 2-7. The optimal conditions for SDS adsorption by modified cellulose were pH of 7, contact time of 3 h, and temperature of 60 °C in this study. Typical adsorption isotherms (Langmuir and Freundlich) were determined for the adsorption process, and the maximal adsorption capacity was estimated as 32.5 mg g-1. The results of adsorption kinetics were more consistent with the pseudo-second-order equation, indicating that the adsorption process was mainly controlled by chemical adsorption. Furthermore, thermodynamic analysis indicated that the adsorption process of SDS on the modified cellulose was endothermic and spontaneous and that an increasing temperature was conducive to adsorption.

Effects of ultrasound irradiation on Au nanoparticles deposition on carbon-coated LiNi0.5Mn1.5O4 and its performance as a cathode material for Li ion batteries.

LiNi0.5Mn1.5O4 (LMNO) has attracted considerable attention as a Li-ion battery cathode material, owing to its high discharge voltage of 4.7 V (vs. Li/Li+) and high energy density. However, the electronic conductivity of LMNO is low, resulting in a low discharge capacity at high current density. To overcome this limitation, we deposited Au nanoparticles (NPs), which have a high conductivity and chemical stability at high battery voltages, on carbon-coated LMNO (LMNO/C) using ultrasound irradiation. Consequently, Au NPs that are ∼16 nm in size were deposited on LMNO/C, and ultrasound irradiation was reported to disperse the NPs on LMNO/C more effectively than stirring. Furthermore, the deposition of Au NPs on LMNO/C using ultrasound irradiation improved its electronic conductivity, which is related to an increase in the discharge capacity due to the reduction of Ni4+ to Ni2+ in LMNO/C at a high current density.

Effect of ultrasound irradiation on asphaltene aggregation and implications to rheological behavior of bitumen.

The present work investigates the contribution of asphaltene aggregation to bitumen viscosity subject to ultrasound irradiation. A West-African bitumen with a viscosity of 12043cP at room temperature was sonicated at low (38 kHz) and mild frequency (200 kHz) under controlled gas environment including air, nitrogen (N2) and carbon dioxide (CO2). The rheology of the bitumen, asphaltene content analyses as well as spectral studies were conducted. Herein was found that sonicating the bitumen at 200 kHz under air-environment reduces the initial viscosity up to 2079cP, which was twice larger than that obtained when a low frequency was used. In respect of the gas environment, it was shown that ultrasound irradiation under N2 environment could lower the bitumen viscosity up to 3274cP. A positive correlation between the asphaltene content and the viscosity reduction was established. The results from the spectral analyses including Fast Fourier Infrared and the observations from Scanned Electron Microscope were consistent with the rheological studies and led to the argument that the viscosity reduction results from either the scission of long chain molecules attached to the aromatic rings (when the applied frequency was altered under fixed gas environment) or the self-aggregation of asphaltene monomers (when gas environment was changed at fixed frequency).

Effect of reaction temperature on the size and morphology of scorodite synthesized using ultrasound irradiation.

Synthesis of scorodite (FeAsO4·2H2O) using dynamic action agglomeration and the oxidation effect from ultrasound irradiation was investigated. The effect of different reaction temperatures (90, 70, 50, and 30°C) on the size and morphology of scorodite particles synthesized under O2 gas flow and ultrasound irradiation was explored because the generation of fine bubbles depends on the solution temperature. At 90°C, the size of scorodite particles was non-homogeneous (from fine particles (<1µm) to large particles (>10µm)). The oxidation-reduction potential (ORP) and yield at 90°C showed lower values than those at 70°C. The scorodite particles, including fine and non-homogeneous particles, were generated by a decrease in the oxidation of Fe(II) to Fe(III) and promotion of dissolution caused by the generation of radicals and jet flow from ultrasound irradiation. Using ultrasound irradiation in the synthesis of scorodite at low temperature (30°C) resulted in the appearance of scorodite peaks in the X-ray diffraction (XRD) pattern after a reaction time of 3h. The peaks became more intense with a reaction temperature of 50°C and crystalline scorodite was obtained. Therefore, ultrasound irradiation can enable the synthesis of scorodite at 30°C as well as the synthesis of large particles (>10µm) at higher temperature. Oxide radicals and jet flow generated by ultrasound irradiation contributed significantly to the synthesis and crystal growth of scorodite.

Redetermination of the low-temperature polymorph of Li(2)MnSiO(4) from single-crystal X-ray data.

Crystals of dilithium manganese(II) silicate were grown under high-temperature hydro-thermal conditions in the system LiOH-MnO(2)-SiO(2). The title compound crystallizes in the ß(II)-Li(3)PO(4) structure type. The coordination polyhedra of all cations are slightly distorted tetra-hedra (m symmetry for MnO(4) and SiO(4)), which are linked by corner-sharing to each other. The vertices of the tetra-hedra point to the same direction perpendicular to the distorted hexa-gonal close-packed (hcp) array of O atoms within which half of the tetra-hedral voids are occupied by cations. In comparison with the previous refinement from powder X-ray data [Dominko et al. (2006 ▶). Electrochem. Commun.8, 217-222], the present reinvestigation from single-crystal X-ray data allows a more precise determination of the distribution of the Li(+) and Mn(2+) cations, giving a perfectly site-ordered structure model for both Li(+) and Mn(2+).

A novel mutation of the bovine EDA gene associated with anhidrotic ectodermal dysplasia in Holstein cattle.

Anhidrotic ectodermal dysplasia (EDA) is a genetic disease characterized by the absence or hypoplasia of hair, teeth and eccrine sweat glands that has been reported in humans, the tabby mouse mutants, cattle and dogs. The EDA gene on the X chromosome encodes a protein, ectodysplasin-A (EDA), which is responsible for EDA. Here we describe a novel mutation of the EDA gene in which a 19 bp deletion in exon 1 in male Holstein calves demonstrated the phenotypic features of EDA. The dam and the grand-dam of the affected calves were heterozygous for this deletion. It is assumed that this deletion close to the start codon confuses all transcripts, and leads to the complete loss of pleiotropic functions of the bovine EDA gene. These results suggest that this mutation might be useful as animal models for the investigation of the pathogenic mechanisms of the anhidrotic ectodermal dysplasia.

Logistical study in Hyogo prefecture on disposal of poultry carcasses infected with highly pathogenic avian influenza virus to prevent infection spreading to other flocks.

Establishment of a disposal plan for carcasses in advance is important for prevention of epidemics. A disposal plan for contaminated goods such as poultry carcasses infected with highly pathogenic avian influenza (HPAI) virus was studied in Hyogo Prefecture, Japan. We investigated all poultry farms with over 1,000 birds for their locations, species and numbers of birds, structure and size of poultry facilities and land spaces of the farms. Moreover, we judged whether they could dispose of all the carcasses at their farms. In 2005, 5.5 million layers and 2.7 million broilers were being kept. If HPAI had broken out, 44.0% of the farmers could bury all the carcasses, and 65.6% could compost them at their farms. However, 23.4% could not dispose of them except by burning them at incineration facilities. We decided to choose burning first for rapid disposal as long as the virus was not a pandemic type.

Solid-liquid separation by sonochemistry: a new approach for the separation of mineral suspensions.

The effect of sonochemistry to acidify solutions was applied for the solid-liquid separation of three kinds of mineral suspensions. At first, the relationship was measured between zeta-potential and pH in these suspensions to find pH levels correspondent to the isoelectric points. Then sonication (200 kHz or 28 kHz) was applied to adjust pH to the isoelectric points and separated particles from solutions by still-standing and spontaneous precipitation. Compared to the conventional methods using filters and chemical agents, the advantage of this sonochemical separation is two-fold. First, it does not require the maintenance of filters. Second, separated particles are easy to use since they are not mixed with pH adjusters and chemical flocculants. Isoelectric zone (ion strength 0.01, concentration 0.001 wt.%) of green tuff, andesite and titanium dioxide suspensions tested in this study were pH 1.1-3.7, 0.8-3.4, 2.7-5.7, respectively. The sonication of green tuff and andesite suspensions at 200 kHz changed the pH to the isoelectric zone despite the pH buffering effect of eluted alkali earth metals, and successfully precipitated the particles. On the contrary, the sonication of these suspensions at 28 kHz failed to adjust pH to the isoelectric zone, and the particles did not precipitate. In addition, the degradation of particles was observed in the SEM photographs of particles sonicated at 28 kHz, whereas no significant change was detected in particles sonicated at 200 kHz. Thus, it is concluded that the optimal frequency is about 200 kHz because its strong chemical effect can easily adjust the pH while its relatively weak physical effect prevents the degradation of particles.