• Journal of Animal Science and Technology
• /
• v.48 no.6
• /
• pp.861-870
• /
• 2006

This study was conducted to examine the effects of supplementing coated vitamin C+E with cottonseed on rumen fermentation and body weight gain, blood metabolites and hormone concentrations in Hanwoo steers fed fermented feedstuff. Experiments were done with two treatment groups, T1 without any supplements and T2 supplemented with coated vitamin C+E and cottonseed. Ruminal pH was lower in T2 than in T1 at 3h after morning feeding (p<0.05), but was higher in T2 than in T1 at 6 and 9h after morning feeding (p<0.05). Ruminal ammonia concentration was higher in T2 than in T1 for 12h after morning feeding (p<0.05). Concentrations of acetate, propionate, butyrate and total-VFA were higher in T2 than in T1 at 3h after morning feeding (p<0.05), but were lower in T2 than in T1 at 9 and 12h after morning feeding (p<0.05). Average daily gain and concentrations of blood metabolites and hormones between T1 and T2 were similar. Results indicate that supplementation of coated vitamin C+E and cottonseed to fermented feedstuff affects on ruminal pH, ammonia and VFA. But it has no influences on body weight gain and concentrations of blood metabolites and hormones in Hanwoo steers.

• Korean Journal Plant Pathology
• /
• v.10 no.3
• /
• pp.197-210
• /
• 1994

This experiment was carried out to study the cause of degeneration and rot of cultivated mushroom. Among 597 bacterial isolates derived from the rots of Button mushroom (Agaricus bisporus), Oyster mushroom (Pleurotus ostreatus) and Oak mushroom (Lentinus edodes) collected from markets of 5 cities (Seoul, Suwon, Taegu, Pohang and Pusan) in Korea (1991~1993), 111 bacterial isolates (18.5%) were proved as pathogenic bacteria. These pathogenic bacteria causing bacterial rots of cultivated mushrooms were identified as Pseudomonas tolasii, P. agarici, and Eriwinia sp., and the main causal bacteria were P. tolaasii. P. fluorescens and Klebsiella plenticola were confirmed as saprophytic non-pathogenic bacteria. One hundred fifty nine isolates (Group No. 39) of the 486 saprophytic bacterial isolates were classified as P. fluorescens, and this species was most often found rot area of cultivated mushrooms. P. tolaasii, the causal organism of bacterial blotch, was classified into two groups; One group can be differentiated from the other by the formation of white precipitation band by white line reacting organisms of Pseudomonas Agar F media. P. tolaasii attacked the cultivated mushrooms relatively well at lower incubation temperature such as 5$^{\circ}C$, but P. agarici rarely attack at below 1$0^{\circ}C$. The temperature for the infection commercial cultivated mushrooms by P. agarici was higher than that of P. tolaasii. Optimum temperature for the infection of mushrooms by P. tolaasii and P. agarici were 2$0^{\circ}C$ and $25^{\circ}C$, respectively.

• Journal of the Korean Chemical Society
• /
• v.31 no.1
• /
• pp.94-97
• /
• 1987

In a converting reaction of $p-bromo-\alpha-diethylaminoacetophenone$ (1a) and $p-bromo-\alpha-piperidinoacetophenone$ (1b) with KCN and $(NH_4)_2CO_3$, to hydantoin, the expected 5-(p-bromophenyl)-5-diethylaminomethylhydantion (2a) and 5-(p-bromophenyl)-5-piperidinomethylhydantoin (2b) were not formed. Diethylaminomethyl group and piperidinomethyl group were eliminated and p,p'-dibromodiphenylhydantil (4), which might be formed through dimerization of 5-(bromophenyl)-hydantoin (3), and p-bromobenzoic acid (5), which was formed through a degradation of 5-(bromophenyl)-hydantoin, were obtained. In the case of $p-bromo-\alpha-morpholinoacetophenone$ (1c), the expected 5-(p-bromophenyl)-5-morpholinomethylhydantoin (2c) was formed.

• Journal of the Korean Ceramic Society
• /
• v.26 no.2
• /
• pp.157-166
• /
• 1989

The effect of pH variation in starting solution on the characteristics of hydroxyapatite precipitates and powder prepared by the wet method was investigated. Hydroxyapatite precipitates was agglomerated, the average agglomerated particle size was decreased in the range from 2 to 6${\mu}{\textrm}{m}$ with increasing pH values in starting solution. The aspect ratio of rod-shaped hydroxyapatite particle was rapidly increased at pH 11 and 11.5. The maximum specific surface area, 91.1$m^2$/g, was at pH 10.5. Dried powder prepared at high pH values contained more minutes CO2 than that prepared at low pH values. The poor crystallinity was maintained up to $600^{\circ}C$ regardless of the pH values in starting solutions. However, the second phase or high crsytalline hydroxypatite phase appeared above 80$0^{\circ}C$. In pH 9.5 and pH 10, $\beta$-whitlockite transformed to $\alpha$-whitlockite at 120$0^{\circ}C$, while in pH 10.5-11.5, hydroxyapatite phase was maintained up to 120$0^{\circ}C$.

• Communications of the Korean Mathematical Society
• /
• v.32 no.4
• /
• pp.959-970
• /
• 2017

In this paper, we investigate the transcendental meromorphic solutions with finite order of two different types of difference equations $${\sum\limits_{j=1}^{n}}a_jf(z+c_j)={\frac{P(z,f)}{Q(z,f)}}={\frac{{\sum_{k=0}^{p}}b_kf^k}{{\sum_{l=0}^{q}}d_lf^l}}$$ and $${\prod\limits_{j=1}^{n}}f(z+c_j)={\frac{P(z,f)}{Q(z,f)}={\frac{{\sum_{k=0}^{p}}b_kf^k}{{\sum_{l=0}^{q}}d_lf^l}}$$ that share three distinct values with another meromorphic function. Here $a_j$, $b_k$, $d_l$ are small functions of f and $a_j{\not{\equiv}}(j=1,2,{\ldots},n)$, $b_p{\not{\equiv}}0$, $d_q{\not{\equiv}}0$. $c_j{\neq}0$ are pairwise distinct constants. p, q, n are non-negative integers. P(z, f) and Q(z, f) are two mutually prime polynomials in f.

• Korean Journal of Microbiology
• /
• v.25 no.1
• /
• pp.67-72
• /
• 1987

Cellular fatty acid composition of eight strains, indluding six strains of Comamonas terrigena, and two type strains of Pseudomonas acidovorans, and P. testosteroni was determined by gas-liquid chromatography. Almost the same composition was found in all the strains tested, and hexadecanoic acid, hexadecenoic acid, and octadecenoic acid were accounted more than 70% of total fatty acid. However, P. testosteroni differed from C. terrigena and P. acidovorans by the presence of comparatively large amonuts of 2-hydroxy-hexadecanoic acid, and C. terrigena contained three to eight times as much tetradecanoic acid in P. acidovorans and P. testosteroni. According to the similarity values calculated on the basis of fatty acid composition, C. terrigena strains were divided into three groups differentiated in the requirement of growth factors, and C. terrigena, P. acidovorans, and P. testosteroni strains occupied separate position each other in the dendrogram.

• Korean Journal of Environment and Ecology
• /
• v.26 no.1
• /
• pp.74-81
• /
• 2012

Decay rate and nutrient dynamics during leaf litter decomposition of deciduous Quercus acutissima and evergreen Quercus mysinaefolia were studied for 24 months from December 2008 to December 2010 in Gongju, Chungnam Province, Korea. Percent remaining weight of Q. acutissima and Q. mysinaefolia leaf litter after 24 months elapsed was $46.3{\pm}5.4%$ and $37.8{\pm}2.5%$, respectively. Decomposition of evergreen Q. mysinaefolia leaf litter was significantly faster than that of deciduous Quercus acutissima leaf litter. Decay constant(k) of Q. acutissima and Q. mysinaefolia leaf litter after 24 months elapsed was 0.38 and 0.49, respectively. Initial C/N and C/P ratio of Q. mysinaefolia leaf litter was significantly lower than those of Q. acutissima leaf litter. Initial C/N and C/P ratio of Q. acutissima leaf litter was 46.8 and 270.9, respectively. After 24 months elapsed, C/N and C/P ratio of decomposing Q. acutissima leaf litter decreased to 22.5 and 104.2, respectively. Initial C/N and C/P ratio of Q. mysinaefolia leaf litter was 22.4 and 41.7, respectively. After 24 months elapsed, C/N and C/P ratio of decomposing Q. mysinaefolia leaf litter decreased to 16.7 and 89.7, respectively. Initial concentration of N, P, K, Ca and Mg in leaf litter was 8.31, 0.44, 4.18, 9.38, 1.37 mg/g in Q. acutissima, and 19.88, 2.73, 7.06, 8.24, 2.61 mg/g in Q. mysinaefolia, respectively. Initial concentration of N and P in Q. mysinaefolia leaf litter was significantly higher than those in Q. acutissima. After 24 month elapsed, remaining N, P, K, Ca and Mg were 100.91, 114.75, 32.99, 50.63, 15.51% in Q. acutissima, and 43.22, 11.35, 12.98, 82.22, 44.23% in Q. mysinaefolia, respectively. N and P in decomposing leaf litter was immobilized in Q. acutissima, and mineralized in Q. mysinaefolia.

• Journal of Korean Society of Forest Science
• /
• v.103 no.2
• /
• pp.159-164
• /
• 2014

The objective of this study was to establish an open-field experimental warming treatment and precipitation manipulation system to simulate climate change impact for Pinus densiflora seedlings based on a climate change scenario in Korea. Two-year-old seedlings were planted in a nursery in April, 2013. The air temperature of warmed plots (W) was set to increase by $3.0^{\circ}C$ compared to control plots (C) using infrared lamps from May, 2013. The three precipitation manipulation consisted of precipitation decrease using transparent panel (-30%; $P^-$), precipitation increase using pump and drip-irrigation (+30%; $P^+$) and precipitation control (0%; $P^0$). Initially, the air temperature was $2.2^{\circ}C$ higher in warmed plots than in control plots and later air temperature was maintained close to the target temperature of $3.0^{\circ}C$. The average soil temperature was $3.1^{\circ}C$ higher in warmed plots than in control plots. Also the average soil moisture content after the precipitation manipulation increased by 13.9% in $P^+W$ and decreased by 10.0% in $P^-W$ compared to $P^0W$, and increased by 23.7% in $P^+C$ and decreased by 7.6% in $P^-C$ compared to $P^0C$. It was confirmed that the open-field experimental warming and precipitation manipulation system was properly designed and operating.

• Journal of the Korean Institute of Telematics and Electronics
• /
• v.20 no.1
• /
• pp.22-26
• /
• 1983

P+N and P+NN+ solar cells with the area of 3.36 $\textrm{cm}^2$ were fabricated by thermal diffusion. Under the light intensity of 100 mW/$\textrm{cm}^2$, total area(active area) conversion efficiency was 13.4%(14.7%) for P+N cell fabricated by 15 min boron predeposition at 94$0^{\circ}C$ and 20 min annealing at 80$0^{\circ}C$, and 14.3%(15.6%) for P+NN+ cell processed by 15 min boron predeposition at 94$0^{\circ}C$ and 50 min annealing at 80$0^{\circ}C$ after 20 min back phosphorus diffusion at 1,05$0^{\circ}C$. The minority carrier lifetime in bulk of P+NN+ cells was increased about 2~3 times comparing with P+N cells because of guttering and BSF effect due to back phosphorus doping. The methods used for efficiency improvement were AR coating, Ag electroplating, back doping and fine grid pattern as well as the control of front doping profile.

• Journal of Sensor Science and Technology
• /
• v.20 no.3
• /
• pp.168-171
• /
• 2011

Porous 3C-SiC(pSiC) samples with different pore diameters were prepared from poly crystalline N-type 3C-SiC by electrochemical anodization. The pSiC surface was chemically modified by the sputtering of Pd and Pt nano-particles as a hydrogen catalyst. Changes in resistance were monitored with hydrogen concentrations in the range of 110 ppm - 410 ppm. The variations of the electrical resistance in the presence of hydrogen demonstrated that Pd and Pt-deposited pSiC samples have the ability to detect hydrogen at room temperature. Regardless of the catalyst, the 25 nm pore diameter samples showed good response and recovery properties. However, the 60 nm samples showed unstable and slow response. It was found that the pore size affects the catalyst reaction and consequently, results in changes of the sensitivity to hydrogen.