Oil-binding capacity of plastic fats: Effects of intermediate melting point TAG

The oil-binding capacity (OBC) of fat crystals was investigated as a function of intermediate melting point TAG (IMP-TAG) and stearin composition. Samples were prepared by melting 14% hard fraction (palm-canola stearin and IMP-TAG blends) in 86% liquid oil (olive, canola, safflower, and triolein) and crystallizing the mixture under fast and slow cooling conditions. Under fast cooling conditions, the OBC increased as the IMP-TAG/stearin ratio increased. The OBC is the grams of bound oil (determined by centrifugation) divided by the grams of solid fat (determined by pulse NMR). The maximum OBC was observed at 14% IMP-TAG and 0% stearin. In constrast, under slow cooling conditions, the 14% IMP-TAG and 0% stearin sample did not form crystals, and only free oil was present. The OBC for each liquid oil was lower under slow cooling conditions than under fast cooling conditions when compared at the same IMP-TAG/ stearin ratio. Solid fat content and RP-HPLC analyses indicated that IMP-TAG were retained in the crystal structure when processed under fast cooling conditions. RP-HPLC analyses also revealed that TAG with two saturated FA were retained in the crystal structure and that the monosaturated TAG were not. It was concluded that the TAG composition and cooling conditions played an important role in determining the OBC.     

Transport of acid dye in nylon and concentration dependence of the diffusion coefficient

The dyeing kinetics of an acid dye (C. I. Acid Blue 40) in a nylon 6 film were investigated using partition-cell and film-roll methods at 80°C and pHs 2.3 and 3.05. The concentration dependence of diffusion coefficient of the dye in the nylon substrate measured by both methods was interpreted in terms of parallel diffusion with biomodel sorption of the Nernst and Langmuir modes. As the concentration of dye increases, the transport of dye inside the nylon film becomes dominated by pore diffusion and surface diffusion of sorbed Nernst populations.     

Crystal Structure of Metastable Tetragonal Zirconia by Neutron Powder Diffraction Study

The crystal structure of metastable tetragonal zirconia prepared by the alkoxide method without any dopant has been examined by neutron diffraction at room temperature. The lattice parameters of this sample were a = 0.3591 ± 0.0001 nm and c = 0.5169 ± 0.0001 nm. The oxygen ions are shifted from their lattice sites in the 〈001〉 direction with a magnitude of Δ/ c = 0.046 ± 0.004.     

Halochromism of acrylic fibres dyed with some disperse dyes

Anomalous dyeing behaviour has been found when regular acrylic fibre treated in hydrochloric acid, in which the sulphonic acid group was present entirely in the acid form, was dyed in neutral condition with azo and anthraquinone disperse dyes. In the very early stages of dyeing there was an abnormally high degree of dye exhaustion, with bathochromic (azo) or hypsochromic (anthraquinone) colour changes on the fibre. These phenomena gradually disappeared after prolonged dyeing, with normal adsorption equilibria and colours eventually being obtained. The results were explained on the basis of protonation by the sulphonic acid groups of treated fibre which occurs at the azo nitrogen or the amino nitrogens of the substituents in the 1 — or 1,4-positions of anthraquinone. The normal adsorption equilibria after prolonged dyeing was attributed to hydrolysis of the cyano side group to form carboxylic acid. This produces ammonia to liberate neutral dye from the protonated dye cation adsorbed electrostatically by the sulphonic acid anion of the treated fibre.     

Broad range observation of particle deposition on greased and non-greased impaction surfaces using a line-sensing optical microscope

A computer-automated optical microscope combined with a line-sensing camera was used to capture the entire range of a particle deposit downstream of an individual acceleration nozzle in a hi-volume Andersen sampler. To investigate the particle bounce and reentrainment, particles collected on collocated greased and non-greased Teflon plates on the inlet stage (d_a>7 μm) were observed by an automated particle counting, locating and sizing method. The result confirmed reproducible collection characteristics among nozzles even though application of the grease increased collection efficiency and altered the size distribution of collected particles to the larger side. In these experiments, assuming spherical particles with uniform density, approximately 65% of particle mass and 50% by number were lost from non-greased plates at 54% RH, while 45% by mass and 25% by number were underestimated at 84% RH. The spatial investigation showed that particles were densely deposited around the center of deposition on greased plates while on non-greased plates they were dispersedly distributed. Particle dispersions on the smooth impaction plate were due to bounce and/or reentrainment of small particles especially with d_PA<10 μm.     

Adequate design of customized cDNA macroarray for convenient multiple gene expression analysis

To establish a convenient, cost-effective, and reasonably reliable method for monitoring multiple gene expression using customized membrane-based macroarray, we constructed a cDNA macroarray with multiple probes for 13 human vascular endothelial genes and assessed the accuracy of the macroarray measurements. For each gene, two cDNA probes (450-550 bp) were designed from different regions (coding region and 3'-untranslated region [3'-UTR], respectively) on the basis of simple criteria concerning length and sequence specificity and spotted on the macroarray. In addition, unmodified oligonucleotide probes (80 mer) targeted to a unique sequence from the coding region of each gene were spotted on the same macroarray. Using this macroarray, shear stress-induced mRNA expression changes were analyzed in human coronary artery endothelial cells. Comparison of the expression ratios obtained with those measured using quantitative real-time polymerase chain reaction (PCR) as a reference method revealed that cDNA probes designed from a sequence within the coding region provided a highly accurate expression profile, whereas results obtained from oligonucleotide probes showed no correlation with real-time PCR data, which might be caused by inadequate immobilization of oligonucletotide probes on the nylon membrane. In addition, we observed that cDNA probes targeting different regions of a gene yielded different signal intensities. Most cDNA probes designed from a sequence within the coding region showed detectable signals, whereas few cDNA probes designed from 3'-UTR did.     

Evaluation of molecular orientation and alignment of poly(3-hexylthiophene) on Au (111) and on poly(4-vinylphenol) surfaces

The orientation and alignment of regioregular poly(3-hexylthiophene) (P3HT) molecules on Au (111) surface and on poly(4-vinylphenol) (PVP) thin film were investigated. The P3HT molecules on the smooth Au (111) are oriented with both the backbones and the side chains parallel to the substrate (plane-on orientation) as revealed by the scanning tunneling microscope (STM) images. However, the P3HT molecules on the PVP thin films are preferably oriented with side chains perpendicular to the surface (edge-on orientation). Surface modification of the PVP by hexamethyldisilazane (HMDS) can increase the crystalline size in the P3HT semicrystalline films. The performance of an all-polymer organic field-effect transistor (OFET) with the drop-cast P3HT semiconductor layer and the crosslinked PVP gate insulator on poly(ethylene naphthalate) (PEN) substrate was evaluated.     

Control of surface migration of gold particles on Si nanowires

On the surface of silicon nanowires (SiNWs) synthesized by gold (Au)-catalyzed chemical vapor deposition (CVD), Au particles 5-20 nm in diameter are formed if the growth conditions are within a specific range. We studied the mechanism of Au particle formation by growing SiNWs under different conditions, specifically by dynamically changing the growth parameters during the growth process. We show that insufficient supply of Si source to the Au-Si eutectic on top of the SiNWs enhances the migration of Au atoms on the surface of SiNWs in the form of Au-Si eutectic, which is precipitated on the surface as Au particles during cooling. We also show that using Au-Si eutectic on the surface of SiNWs as a catalyst enables one-step growth of branched SiNWs.