Application of Psf–PPSS–TPA composite membrane in the all-vanadium redox flow battery

The Psf–PPSS–TPA composite cation exchange membrane consist of Psf(polysulfone)–PPSS (polyphenylenesulfidesulfone) block copolymer with TPA (tungstophosphoric acid) is prepared to apply for a separator in the all-vanadium redox flow battery. The membrane properties such as membrane resistance and ion exchange capacity, and thermal stability are investigated. The prepared Psf–PPSS–TPA composite cation exchange membrane showed higher thermal stability than Nafion117. The lowest membrane resistance of the prepared Psf–PPSS–TPA composite cation exchange membrane measured in 1 M (mol/dm³) H₂SO₄ aqueous solution was 0.94 Ω cm² at 0.5 g of TPA solution. The performance properties of the all-vanadium redox flow battery (V-RFB) using the prepared cation exchange membrane are measured. The electromotive force, open circuit voltage at state of charge (SOC) of 100%, was 1.4 V. This value meets a theoretical electromotive force value of the V-RFB. The measuring cell resistance in charge and discharge at SOC 100% were 0.26 Ω and 0.31 Ω, respectively. The results of the present study suggest that the prepared Psf–PPSS–TPA composite cation exchange membrane is well suited for use in V-RFB as a separator.     

Synthesis and characterization of cation‐exchange membrane based on sulfonated sty/HEA/LMA terpolymer

A cation‐exchange membrane based on a styrene/hydroxyethyl acrylate/lauryl methacrylate (Sty/HEA/LMA) terpolymer was prepared via a postsulfonation reaction for various sulfonation times. Sulfonic groups were introduced into the membrane structure with sulfuric acid as the sulfonating agent and silver sulfate as an initiator in a nitrogen atmosphere. Sulfonated Sty/HEA/LMA terpolymer membranes were characterized by Fourier transform infrared (FTIR) spectrometry and nuclear magnetic resonance as well as by determining the degree of sulfonation (DS), ion‐exchange capacity (IEC), water uptake (WU), and electrical property of the membranes. The presence of sulfonic groups in the sulfonated Sty/HEA/LMA terpolymer was confirmed by FTIR, and the resulting membrane showed an IEC of 1.29 meq/g and an electrical resistance of 0.1 Ω cm². The WU of the prepared membranes increased with the DS at the reaction time. The surface morphology obtained by atomic force microscopy clearly showed an increase of roughness with reaction time. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Laminar burning velocity predictions by meso-scale flames in an annular diverging tube

Flame behavior in an annular diverging tube (ADT) consisting of an outer quartz tube and a tapered inner core column was investigated as a basic model for small combustion devices of various combustion space scales. Flames can be stabilized at suitable locations where the mean flow velocity is matched to the spatial average propagation velocity (SAPV). Transient variations of wall temperature and the SAPV were compared for various experimental parameters: inner core materials, burner configurations, and flow rates. It was found that a critical propagation velocity (CPV) exists that is least affected by the flow rates. The CPVs of methane, propane, and dimethyl ether (DME) were measured and a good agreement was shown between the measured CPVs and the laminar burning velocities presented in the literatures. Therefore, the ADT method can be a model for small combustion devices of various combustion space scales; furthermore, this study can be beneficial in designing and operating small combustion devices. The ADT method can also be applied in the field for in situ monitoring of the burning velocities.     

Simultaneous amplification by Er ions and SRS in an Er-doped germano-silica fiber

A flat signal gain over in the entire C- and L-bands by erbium (Er) ions' radiative transition and stimulated Raman scattering in an Er-doped germano-silica fiber can be obtained if proper values of the concentration of Er and background loss in a fiber core are obtained during the fiber fabrication process. The optimized conditions for the flat C- and L-band gain are analyzed as functions of Er concentrations. Even for a low-gain value provided by a germano-silica core fiber with a low Er concentration and an optimum fiber length, a relatively low pump is required to obtain the flat gain band.     

Effect of surface treatment of ramie fiber on the interfacial adhesion of ramie/acetylated epoxidized soybean oil (AESO) green composite

Recently, many researchers have attempted to convert soybean oil into useful polymers. One of the ways to make soybean oil into a matrix of green composites is to modify its triglyceride structure to obtain the acrylated epoxidized soybean oil (AESO) through epoxidization and acrylation. In this study, the effects of ramie fiber surface treatments such as acetylation, silane, and peroxide treatments on the chemical, morphological, and interfacial adhesion properties of a ramie/AESO green composite were studied. Surface-treated fibers were characterized by scanning electron microscopy, Fourier transform infrared spectroscopy, and dynamic contact angle analysis. The crystallinity and thermal stability of chemically treated fibers were investigated by wide angle X-ray diffraction and thermogravimetric analyzer. It was demonstrated that surface treatments lead to several morphological changes, including the formation of micro-cracks and removal of impurities by acetylation and peroxide treatment as well as surface smoothing by silane treatment. Surface energy of acetylated fiber decreased with treatment time and showed the lowest value for silane treated fiber. The interfacial shear strength (IFSS) of a fiber/AESO composite was investigated through the microbond test. The IFSS of silane treated ramie was higher than that of others. The result indicates that silane treated fibers improve the interfacial property, which is the most important characteristic for the end use of green composites.     

Discoloration mechanism of polymer surface in contact with air–water interface

The white-colored inner surface of a polypropylene (PP) material containing water discolored and turned yellow. The discoloration occurred selectively on the surface at the point of contact with the air–water interface. Since the polymer surface was exposed to water in darkness at room temperature, no sign of deterioration or degradation of the polymer at the discolored surface was confirmed. This study conducts an in-depth analysis of the discoloration mechanism of the polymer surface. A variety of technical approaches, including microscopic, spectroscopic, and chromatographic analysis techniques, were used to investigate the nature of discoloration and the root cause. From the analysis results, the discoloration was ascribed principally to a phenol transformation compound having the structure of a quinone methide, which was identified as a degradation product of a primary antioxidant. Based on the observations and experimental results, a plausible discoloration mechanism was proposed.     

Identification of Novel Pepper Genes Involved in Bax- or INF1-Mediated Cell Death Responses by High-Throughput Virus-Induced Gene Silencing

Hot pepper is one of the economically important crops in Asia. A large number of gene sequences, including expressed sequence tag (EST) and genomic sequences are publicly available. However, it is still a daunting task to determine gene function due to difficulties in genetic modification of a pepper plants. Here, we show the application of the virus-induced gene silencing (VIGS) repression for the study of 459 pepper ESTs selected as non-host pathogen-induced cell death responsive genes from pepper microarray experiments in Nicotiana benthamiana. Developmental abnormalities in N. benthamiana plants are observed in the 32 (7%) pepper ESTs-silenced plants. Aberrant morphological phenotypes largely comprised of three groups: stunted, abnormal leaf, and dead. In addition, by employing the combination of VIGS and Agrobacterium-mediated transient assays, we identified novel pepper ESTs that involved in Bax or INF1-mediated cell death responses. Silencing of seven pepper ESTs homologs suppressed Bax or INF1-induced cell death, five of which suppressed both cell death responses in N. benthamiana. The genes represented by these five ESTs encode putative proteins with functions in endoplasmic reticulum (ER) stress and lipid signaling. The genes represented by the other two pepper ESTs showing only Bax-mediated cell death inhibition encode a CCCH-type zinc finger protein containing an ankyrin-repeat domain and a probable calcium-binding protein, CML30-like. Taken together, we effectively isolated novel pepper clones that are involved in hypersensitive response (HR)-like cell death using VIGS, and identified silenced clones that have different responses to Bax and INF1 exposure, indicating separate signaling pathways for Bax- and INF1-mediated cell death.     

Effect of Nanoencapsulated Vitamin B1 Derivative on Inhibition of Both Mycelial Growth and Spore Germination of Fusarium oxysporum f. sp. raphani

Nanoencapsulation of thiamine dilauryl sulfate (TDS), a vitamin B1 derivative, was proved to effectively inhibit the spore germination of Fusarium oxysporum f. sp. raphani (F. oxysporum), as well as mycelial growth. The average diameter of nanoparticles was measured as 136 nm by being encapsulated with an edible encapsulant, lecithin, whose encapsulation efficiency was about 55% in containing 200 ppm of TDS concentration: the 100 ppm TDS nanoparticle solution showed a mycelial growth inhibition rate of 59%. These results were about similar or even better than the cases of treating 100 ppm of dazomet, a positive antifungal control (64%). Moreover, kinetic analysis of inhibiting spore germination were estimated as 6.6% reduction of spore germination rates after 24 h treatment, which were 3.3% similar to the case of treating 100 ppm of a positive control (dazomet) for the same treatment time. It was also found that TDS itself could work as an antifungal agent by inhibiting both mycelial growth and spore germination, even though its efficacy was lower than those of nanoparticles. Nanoparticles especially played a more efficient role in limiting the spore germination, due to their easy penetration into hard cell membranes and long resident time on the surface of the spore shell walls. In this work, it was first demonstrated that the nanoparticle of TDS not a harmful chemical can control the growth of F. oxysporum by using a lower dosage than commercial herbicides, as well as the inhibiting mechanism of the TDS. However, field trials of the TDS nanoparticles encapsulated with lecithin should be further studied to be effectively used for field applications.     

Effect of Cryoprotectant and Freeze-Drying Process on the Stability of W/O/W Emulsions

In order to protect a hydrophilic drug and to prolong its further delivery, the formulation of multiple emulsions could be worthy. However, the double emulsions are not stable, their structure can change, leading to the formation of a single emulsion as the destruction of the system, and the drug can release easily from the globules in liquid state. The freeze-drying technology could be used to produce dry emulsion, the powder form being much more stable. The aim of this work was to study the influence of a cryoprotectant and a freeze-drying process on the stability of W/O/W emulsions. Samples were frozen at two different freezing rate (ν _f  = 0.55°C/min and 1.25°C/min) and successively dried at two different sublimation temperature (T _s  = ? 10°C and ? 20°C). The particle size distributions were measured by granulometer and UV spectrophotometer was performed to investigate the leakage of internal constituent. The glass transition temperature (T _g ) of the double emulsions was analyzed by DSC. The particle sizes became even smaller after freeze drying, except when κ-carrageenan is used as a cryoprotectant. In that case, the particles became aggregated after freeze drying, whatever the process conditions. The mean size is considerably reduced when the globules are diluted at low concentration in glucose and trehalose solution. When the concentration is increased, the size distribution is not significantly affected. The leakage of the internal aqueous phase to the external one during freeze drying was measured as an indicator of the structure stability. It is affected by the nature of the cryoprotectant and the conditions of the freeze-drying process. The leakage of the internal phase was smaller when cycle III (ν _f  = 1.25°C/min, T _s  = ? 10°C) was processed. From our experiments, we suppose that the water transfer from the inner phase to the outer aqueous phase results in the diminution of the globules size in double emulsion. The T _g of the double emulsions diluted with trehalose and glucose were determined at ? 33.8°C and ? 47.1°C. In contrast, the T _g of double emulsion with κ-carrageenan and HES did not appear.     

Loss of Fat with Increased Adipose Triglyceride Lipase-Mediated Lipolysis in Adipose Tissue During Laying Stages in Quail

The goal of the current study was to investigate regulation of key genes involved in lipid metabolism in adipose and liver to relate lipolytic and lipogenic capacities with physiological changes at the pre-laying, onset of laying, and actively laying stages of quail. Followed by a 50 % increase from pre-laying to onset of laying, adipose to body weight ratio was significantly reduced by 60 % from the onset of laying to the actively laying stage (P < 0.05), mainly resulting from the significantly increased adipocyte size from the pre-laying stage to the onset of laying and reduction of adipocyte size from the onset of laying to the actively laying stage (P < 0.05). In the adipose tissue of actively laying quail, increased protein expression and phosphorylation of adipose triglyceride lipase (ATGL) together with an elevated mRNA expression of comparative gene identification-58, an activator of ATGL, contributes to increased lipolytic activity, as proved by increased amounts of plasma non-esterified fatty acid (P < 0.05). In addition, decreased mRNA expression of fatty acid transport protein in the actively laying quail could contribute to the adipocyte hypotrophy (P < 0.05). In the liver, relative mRNA expression of apo-very low density lipoprotein (VLDL)-II increased significantly from the pre-laying to actively laying stages (P < 0.05), indicating increased apoVLDL-II actively facilitated VLDL secretion in the actively laying quail. These results suggest that the laying birds undergo active lipolysis in the adipocyte, and increase VLDL secretion from the liver in order to secure a lipid supply for yolk maturation.