Effect of SiC and ZnO Nanoparticles on UV Absorbance and Heat Transfer of PET Composite Film

Zinc oxide (ZnO) and silicon carbide (SiC) nanoparticles were compounded with polyethylene terephthalate (PET) by using a twin screw extruder, and their effect on the UV absorption and heat transfer in PET/ZnO and PET/SiC composite films was investigated. The presence of ZnO and SiC in the PET matrix was verified by X-ray diffraction. The UV absorbance of both PET/ZnO and PET/SiC composite films increased with increasing particle content. The UV absorbance of PET/SiC was higher than that of PET/ZnO under the same particle content. A thermal imaging camera was used to analyze the heat transfer in PET/ZnO and PET/SiC composite films after heating them to 40 °C. As the content of ZnO and SiC particles increased, the temperature decreased more rapidly. PET/SiC showed faster cooling than PET/ZnO because of the higher thermal conductivity of SiC compared to that of ZnO. Response temperature surfaces for PET/ZnO and PET/SiC were obtained by using an exponential decay function and a second order equation, and the elapsed times to cool to room temperature were estimated.     

Effect of solvent and blended polymer on electrical conductivity of PEDOT:PSS/polymer blended nanofibers

Poly(3,4-ethylenedioxythiophene)/poly(styrene sulfonate) (PEDOT:PSS) and polyethylene oxide (PEO) (or polyvinyl alcohol (PVA)) blended electrospun nanofibers were prepared in the presence of dimethyl sulfoxide (DMSO) and ethylene glycol (EG). The effects of added solvents (DMSO and EG) and blended polymers (PEO and PVA) on electrical conductivity and current-voltage (I-V) response were investigated. Electrical conductivity was dependent on both the additional solvent and blended polymers. PEDOT:PSS/PEO blended nanofibers showed a much higher electrical conductivity than PEDOT:PSS/PVA. EG blended PEDOT:PSS/PEO blended nanofibers showed much higher electrical conductivity than DMSO. The PEDOT:PSS/PEO/EG blended nanofibers web showed the highest value in I-V response.     

Evaluation of future climate change impact on snow hydrology for a mountainous watershed of South Korea using SLURP model and NOAA AVHRR images

This study is to evaluate the future potential climate impact on snow hydrology using SLURP model for a 6661.0 km² mountainous watershed of South Korea. For the model test, the NOAA AVHRR images were analyzed to prepare snow-related data of the model. Snow cover areas were extracted using channels 1, 3, and 4, and the snow depth was spatially interpolated using snowfall data of 11 ground meteorological stations. With the snowmelt parameters (snow cover area, snow water equivalent, and snow depth), the model was calibrated for 2 sets (2002–2003, 2004–2005), and verified for 2 sets (1997–1998 and 2001–2002) using the calibrated parameters. The average Nash–Sutcliffe efficiencies during the full year period (December to November) and snowmelt period (December to April) were 0.60 and 0.66, respectively. The future climate data of CCCma CGCM2 SRES A2 and B2 scenarios were adjusted and downscaled using change factor method. By the future impact of climate change, the annual dam inflows were projected to change maximum ?29.3 and ?30.4 % for 2090s A2 scenario and 2030s for B2 scenario, respectively. The future dam inflow increased in winter season (December to February) up to 222.0 %, while other periods decreased up to 54.8 %. The future snowmelt increased in December and January by the future temperature increase of 3.9 °C in minimum. The future snowmelt for the 2 months affected the dam inflows during the winter season.     

An outbreak of fatal hemorrhagic pneumonia caused by Streptococcus equi subsp. zooepidemicus in shelter dogs

An outbreak of fatal hemorrhagic pneumonia with 70~90% morbidity and 50% mortality occurred in an animal shelter in Yangju, Gyeonggi Province, Korea. Clinically, the affected dogs showed severe respiratory distress within 48 h after arriving in the shelter. The dead were found mainly with nasal bleeding and hematemesis. At necropsy, hemothorax and hemorrhagic pneumonia along with severe pulmonary consolidation was observed, though histopathological analysis showed mainly hemorrhagic bronchopneumonia. Lymphoid depletion was inconsistently seen in the spleen, tonsil and bronchial lymph node. Gram-positive colonies were shown in blood vessels or parenchyma of cerebrum, lung, liver, spleen, and kidney. Also, Streptococcus (S.) equi subsp. zooepidemicus was isolated from the various organs in which the bacterium was microscopically and histologically detected. In addition, approximately 0.9 Kb specific amplicon, antiphagocytic factor H binding protein, was amplified in the bacterial isolates. In this study, we reported an outbreak of canine hemorrhagic bronchopneumonia caused by S. equi subsp. zooepidemicus in an animal shelter in Yangju, Korea.     

Genetic analysis of ORF5 of recent Korean porcine reproductive and respiratory syndrome viruses (PRRSVs) in viremic sera collected from MLV-vaccinating or non-vaccinating farms

The 23 open reading frame (ORF) 5 sequences of Korean type II porcine reproductive and respiratory syndrome virus (PRRSV) were collected from viremic sera from the (modified live vaccine) MLV-vaccinating and non-vaccinating farms from 2007 to 2008. The samples were phylogenetically analyzed with previous ORF5 sequences, including type I Korean PRRSV, and previously reported or collected sequences from 1997 to 2008. A MN184-like subgroup of type II Korean PRRSV was newly identified in the viremic sera collected from 2007 to 2008. And of the type I PRRSVs, one subgroup had 87.2~88.9% similarity with the Lelystad virus, showing a close relationship with the 27~2003 strain of Spain. The maximum parsimony tree of type II PRRSV from 1997 to 2008 showed that they had evolved to four lineages, subgroups 1, 2, 3 and 4. Most of the recently collected type II PRRSVs belonged to subgroup 4 (48%). The region of three B-cell epitopes and two T-cell epitopes of ORF5 amino acids sequences was considerably different from the MLV in subgroups 3 and 4. In conclusion, the existence of type I PRRSV, which was genetically different from Lelystad virus (Prototype of type I PRRSV), and heterologous type II PRRSVs of viremic pigs detected even in the MLV-vaccinating farms indicated the need for new vaccine approaches for the control of PRRSV in Korea.     

Fatty acid composition and meat quality traits of organically reared Korean native black pigs

Current study investigated the effect of feeding systems (conventional vs organic rearing) on carcass characteristics, meat quality and fatty acid composition of Musculus longissimus dorsi of Korean native black barrows (KNP). Thirty pigs were reared under a conventional feeding system at indoor area of 1 m² per head, while another thirty pigs were fed an indoor area with organic saw dusts of 1 m² and an outdoor area with free ranges of 1 m² for each pig for organic system. Diet for the organic rearing was also provided according to the guideline for organic pork products. Warner–Bratzler shear force was lower and water holding capacity was higher for pork produced under the organic guidelines. However, pork produced by an organic system did not affect sensory traits compared to pork produced by a conventional one. In addition, longissimus muscle from organically reared pigs had significantly (P < 0.05) higher myoglobin content and consequently higher CIE a?-values compared with those for the conventionally-reared pigs (P < 0.05). The organic pork resulted in significantly (P < 0.05) higher polyunsaturated fatty acid (PUFA) and unsaturated fatty acid contents, as well as a higher n-3 PUFA than the conventional one (P < 0.05).     

Changes in anthocyanin and isoflavone concentrations in black seed-coated soybean at different planting locations

This study assessed the altitudinal variations in the anthocyanin and isoflavone contents of six black seed coated soybean [Glycine max (L.) Merrill] cultivars. The black soybean cultivars Heugcheong, Seonheuk, Geomjeong 1, Geomjeong 2, Cheongja 2, and Cheongja 3 were planted at Milyang (12 m above mean sea level — low altitude) and Muju (600 m — high altitude), Korea on 10 June 2005 and 2006. The total anthocyanin and isoflavone contents and individual components were investigated by reverse-phase high performance liquid chromatography (HPLC). All black soybean cultivars cultivated in high altitude possessed significantly higher total anthocyanin (p < 0.01) and isoflavone (p < 0.01) contents than those grown in low altitude. For anthocyanin composition, cyanidin-3-O-glucoside, cyanidin-3-O-galactoside, and peonidin-3-O-glucoside contents were significantly higher while delphinidin-3-O-glucoside contents was significantly lower at high altitude. The composition of individual isoflavones, 6″-O-malonyldaidzin, and 6″-O-malonylgenistin contents significantly increased at high altitude.     

Characterization and application of recombinant β-glucosidase (BglH) from <Emphasis Type="Italic">Bacillus licheniformis</Emphasis> KCTC 1918

β-Glucosidase (β-1,4-D-glucoside glucohydrolase: EC.3.2.1.21) catalyzes the hydrolysis of β-glucosidic bonds between saccharides and aryl or alkyl groups. A gene encoding β-glucosidase from Bacillus licheniformis KCTC 1918, an anaerobic spore-forming soil bacterium, was cloned and characterized. The structural gene for the β-glucosidase consists of 1410 bp encoding 469 amino acid residues, and has a molecular weight of 53.4 kDa as estimated by sodium dodecyl sulfate polyacrylamide gel electrophoresis with 12% separating gel. The enzyme activity was determined against pNPG as a substrate. The enzyme was optimally active at pH 6.0 (citrate-phosphate buffer) and 47°C. β-Glucosidase retained 100% of its original activity for 24 h. The activity of the enzyme was stimulated by glycerol and urea and was decreased by Ca²⁺, Cu²⁺, Hg²⁺, Mg²⁺, and Mn²⁺. In particular, Cu²⁺ had the strongest negative effect on β-glucosidase activity. The purified β-glucosidase was active against pNPG and cellobiose. When the β-glucosidase was tested for cellulose hydrolysis, the supplement of β-glucosidase with cellulose increased the glucose yield from pine wood powder by 139.8%.     

Evaluation of Activated Carbon-Coated Electrode in Electrostatic Precipitator and Its Regeneration for Volatile Organic Compounds Removal

Activated carbon-coated electrode was developed and applied in electrostatic precipitator to remove volatile organic compound gases simultaneously with dust particles from a contaminated air. The activated carbon coating mixture was made up of powdered activated carbon (AC), carbon black (CB), and polyvinyl acetate (PVA), and methanol was added as a solvent to control the thickness of the mixture for best coating performance. During the coating process, the Brunauer-Emmett-Teller (BET) surface decreased to 86% of the original AC while pore volume percentages of macro pore increased, compared to micro- and meso-sized pores. The adsorption isotherm of benzene, toluene, ethyl benzene, and xylene (BTEX) gases onto the original AC and AC coating mixture (AC thoroughly mixed with PVA and methanol for coating and powdered again after dry) were tested and compared to each other, and it was found that both isotherm were best fitted to Freundlich and Langmuir isotherm with the order of adsorption capacities; ethyl benzene?>?m-xylene?>?toluene?>?benzene. The difference between adsorption capacities was clearer with the absorbent AC but became little with the AC coating mixture. In removing BTEX at increasing linear velocities up to 6.7 cm/s, it appeared that the surface area of AC electrode was directly proportional to its removal rate of BTEX. The thermal desorption was applied to regenerate the AC electrode, and 200 °C was found to be most efficient for benzene desorption, but higher temperature would be required for entire BTEX gases desorption.