Authors:T. C. K. Yang, W. H. Chang and D. S. Viswanath
Thermal degradation of poly(vinyl butyral) (PVB) and its mixtures with alumina, mullite and silica was investigated by non-isothermal thermogravimetry in the temperature range of 323 to 1273 K. The analysis of the data was carried out using a three-dimensional diffusion model. Results showed that the kinetic parameters (activation energy and pre-exponential factor) of the PVB degradation are different for polymer alone, and ceramic/polymer composites. The overall weighted mean apparent activation energy showed an increasing reactivity in the order of PVB<alumina+PVB<mullite+PVB<silica+PVB. This shows that the acidic and basic surface characteristics of the ceramics promote the thermal degradation of PVB and, the more acidic silica affects the degradation more than mullite and alumina. The effect of pellet compression pressure in the range of 4000 to 8000 psig is also investigated.
Measurement of 3H, 14C, 32P, 35S, 125I, and 131I in radioisotope (RI) waste materials such as the vials, pipette tips, tubes, syringes, and paper generated from the industrial,
medical, educational, and research organizations were conducted by a wet oxidation method. Counts were obtained by a liquid
scintillation counter for 3H, 14C, and 32P; a gas proportional counter for 35S; a low energy photon spectroscopy for 125I; and an HPGe detector for 131I. After the treatment of approximately 20 g of the sample, the counting value was determined to obtain a minimum detectable
activity (MDA) of approximately 1 × 10−3 ~ 5 × 10−2 Bq/g. The specific activities of shor-half-life RIs (32P, 35S, 125I, and 131I) were not detectable and/or resulted in a low value (<1 Bq/g). The waste containing 3H and 14C was observed to have the specific activities in the range of 10−2–105 and 10−2–104 Bq/g, respectively.
Authors:K. Shang, Y. Yang, J. Guo, W. Lu, F. Liu and W. Wang
The extraction of cobalt by Winsor II microemulsion system was studied. In the bis (2-ethylhexyl) sulfosuccinate sodium salt
(AOT)/n-pentanol/n-heptane/NaCl system, AOT was used as a anionic surfactant to form microemulsion in n-heptane, n-pentanol was injected in the microemulsion as a cosurfactant. Co(II) was found to be extracted into the microemulsion phase
due to ion pair formation such as Co2+(R–SO3−)Cl. The influence of different parameters such as the volume ratio of aqueous phase to microemulsion, surfactant concentration,
pH of the feed solutions, cosurfactant concentration as well as temperature on the extraction yield (E%) were investigated. The results showed that it was possible to extract 95% of cobalt by the AOT Winsor II microemulsion.
Authors:K. Tung, J. Liu, F. Cheng, C. Yang, W. Tu, K. Wang, C. Shyu, C. Lai, C. Chou and W. Lee
is one of the
species most commonly found in the wild field, which can cause severe infection and mortality in young sparrows. In this study, we selected
(Chung Hsing strain) as a pathogen to orally inoculate russet sparrows (
), spotted munia (
), canary (
), Java sparrows (
), chicken (
), ducks (
) and BALB/c mice. The results indicated that
infected only russet sparrows. Infected sparrows displayed lethargy, muscular weakness and fluffy feathers, followed by rapid death. Liver and spleen enlargement was seen in the infected birds. Schizonts were identified in thin smears from the venous blood, enlarged livers and spleens. Histopathological examination revealed schizonts and merozoites from the liver and spleen of infected russet sparrows, but not from other species experimentally inoculated with
in the present study.
Authors:Xiufang Zhang, G. Yang, Y. Liu, W. Yu, K. Pan, Ruixiang Li and M. Zhu
Prorocentrum donghaiense caused large-scale red tides off Chinese coast in recent years. Expressed sequence tag (EST) analysis was carried out for this dinoflagellate in order to identify the genes involved in its proliferation and death. A cDNA library was constructed for P. donghaiense at late exponential growth phase, and 308 groups of EST were generated, which include 36 contigs and 272 singletons. Among 22 groups showed homologies with known genes, 2 matched significantly with caspase and proliferating cell nuclear antigen. Caspase and proliferating cell nuclear antigen are 2 key proteins involved in programmed cell death. Their identification evidenced preliminarily the induction of PCD in aging P. donghaiense. The identified included also calmodulin and protein phosphatase, two proteins involved in diverse cell processes including PCD by binding to or modifying others.
Authors:T.-K. Wang, Y.-D. Yang, B. Du, S. Yu and W.-L. Hou
Chestnut exhibits anti-inflammatory, styptic, anti-diarrhea, and analgestic effects as a traditional Chinese medicine. There is increasing evidence that shows that the consumption of chestnuts has become more important in human nutrition due to the health benefits provided by the antioxidants. The phenolic compounds are responsible for major bioactivities, such as anti-tumor and anti-oxidation. A high-performance liquid chromatography (HPLC) method with diode array detection (DAD) was established for the simultaneous determination of six phenolic compounds (gallic acid, GA; protocatechuic acid, PR; catechin, CA; epicatechin, EP; quercetin, QU; kaempferol, KA) in Chinese chestnut (Castanea mollissima blume) kernel. The sample followed by separation on Eclipse XDB-C18 column (150 × 4.6 mm, id., 5 μm) with gradient elution of methanol-1.0% acetate acid solution as a mobile phase, at a temperature of 30°C, under the ratio of 1.2 mL min−1, with 5 μL injection volume, and multi-wavelength synthesis was used with DAD. The correlation coefficients were larger than 0.999, the recoveries were 97.58% for GA, 100.41% for PA, 96.23% for CA, 101.38% for QU, 99.15% for EP, and 98.60% for KA, relative standard deviation (RSD) were 1.04% for GA, 1.21% for PA, 1.09% for CA, 1.19% for QU, 1.06% for EP, and 1.20% for KA. This method was applied for the determination of phenolics in chestnut kernel and was found to be fast, sensitive, and suitable.
Authors:Heung Lee, S. Kim, M. Hur, S. Yang, W. Kim and K. Jee
3H and 14C Measurements of the dry active waste (DAW), such as the cotton, paper, and vinyl, generated from a nuclear power plant (NPP)
were conducted with wet oxidation using open vessel equipment based on simulation results. The recovery efficiency with the
simulated samples was around 93% with a relative standard deviation (RSD) of 1–3%. A liquid scintillation counter (LSC) was
used for counting and adjusted to a quenching correction curve. The counting value was evaluated for the minimum detectable
activity (MDA), which was found to be about 4 × 10−1 Bq/g for 3H and 2 × 10−2 for 14C when approximately 5 g of the samples were measured. The measured DAW samples for the cotton, paper, and vinyl generated
from NPP achieved of RSD values of 25, 25, and 60%, respectively, for 3H and 0–50% for 14C.
Authors:J.L. Wang, Y.N. Wang, D.C. Liu, X.L. Guo, W.L. Yang, K.H. Zhan, X.J. Wang and A.M. Zhang
Aegiolops kotschyi cytoplasmic male sterile system often results in part of haploid plants in wheat (Triticum aestivum L.). To elucidate the origin of haploid, 235 wheat microsatellite (SSR) primers were randomly selected and screened for polymorphism between haploid (2n = 3x = 21 ABD) and its parents, male-sterile line YM21 (2n = 6x = 42 AABBDD) and male fertile restorer YM2 (2n = 6x = 42 AABBDD). About 200 SSR markers yielded clear bands from denatured PAGE, of which 180 markers have identifiable amplification patterns, and 20 markers (around 8%) resulted in different amplification products between the haploid and the restorer, YM2. There were no SSR markers that were found to be distinguishable between the haploid and the male sterile line YM21. In addition, different distribution of HMW-GS between endosperm and seedlings from the same seeds further confirmed that the haploid genomes were inherited from the maternal parent. After haploidization, 1.7% and 0.91% of total sites were up- and down-regulated exceeding twofold in the shoot and the root of haploid, respectively, and most of the differentially expressed loci were up/down-regulated about twofold. Out of the sensitive loci in haploid, 94 loci in the shoot, 72 loci in the root can be classified into three functional subdivisions: biological process, cellular component and molecular function, respectively.