• Bulletin of the Korean Chemical Society
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• v.25 no.6
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• pp.823-828
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• 2004

The crystal structures of sparteinium tetrachlorocuprate monohydrate $[(C_{15}H_{28}N_2)CuCl_4{\cdot}H_2O]$, 1 and sparteinium tetrabromocuprate monohydrate $[(C_{15}H_{28}N_2)CBr_4{\cdot}H_2O]$, 2, were determined. The structures of 1 [orthorhombic, $P2_12_12_1$, a = 8.3080(10) ${\AA}$, b = 14.6797(19) ${\AA}$ and c = 16.4731(17) ${\AA}$], and 2 [orthorhombic, $P2_12_12_1$, a = 8.4769(7) ${\AA}$, b = 15.166(3) ${\AA}$ and c = 16.679(3) ${\AA}$], are composed of a doubly protonated sparteinium cation, $[C_{15}H_{28}N_2]^{2+}$, a discrete $CuX_4^{2-}$ anion $(X=Cl^-\;or\;Br^-)$, and one water molecule. These monomeric compounds are stabilized through various types of hydrogen bonding interaction in their packing structures. Crystal 2 exhibits weak anti-ferromagnetism (J = -3.24 $cm^{-1}$) as opposed to the magnetically isolated paramagnetism observed for 1. The results of comparative magneto-structural investigations of 1 and 2 suggest that the pathway for the weak anti-ferromagnetic super-exchange in 2 might be through a Cu-Br${\cdots}$Br-Cu contact.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.32 no.6
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• pp.753-757
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• 1999

The growth of rotifer, Brachionus rotundiformis was evaluated at different culture conditions. Rotifer was fed on condensed freshwater Chlorella. The productivity of rotifer in the high density culture system was compared to that of rotifer in the batch culture system, in which rotifer was fed on baker's yeast. The growth rate of rotifer increased as temperature increased in the culture system supplied with air or oxygen gas. The maximum density of rotifer in the culture systems supplied with air was in range of 16,300$\~$17,000 ind./ml at $24^{\circ}C$. In the culture systems supplied with oxygen gas, it ranged 26,300$\~$30,500 ind/ml at $28^{\circ}C$. When the concentration of dissolved oxygen in the culture system supplied with air reached to below 1 ppm or when the concentration of undissolved ammonia in the culture system supplied with oxygen gas reached 16.6$\~$22.6 ppm, the growth of rotifer decreased. When oxygen gas was supplied and pH was adjusted to 7, the maximum density of rotifer reached to 43,000 ind/ml at $32^{\circ}C$. The production costs for 10 billion rotifer in the high density culture and batch culture were 693,000 and 961,000 won, respectively. Therefore, it was concluded that the productivity of rotifer in the high density culture was higher than that in a batch culture.

• Korean Journal of Food Science and Technology
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• v.23 no.5
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• pp.572-577
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• 1991

Fermented Korean soybean foodstuffs(12 samples of meju, 28 samples of doenjang and 28 samples of kanjang) which collected nation wide in Korea, were used to isolate of fungi. And the fungi producing ochratoxin A(OA) among isolated fungi were identified. Of total 222 fungi isolated in each samples, the production rate of OA was 17.7%(39/222). Four fungi out of 39 isolates which production OA showed a higher amount of ochratoxin A. From these results, four kinds of fungi producing large quantities of OA were Penicillium spp., Phialotubus microsporus, Eupenicillium lapidosum, and Paecilomyces variotti, respectively. Four fungi showed the optimum growth at water activity($a_{w}$) of 0.99, but production of OA was almost inhibited at $a_{w}$, of 0.85. Furthermore, three fungi except P. variotti showed the optimum growth at $30^{\circ}C$, while OA production inhibited at same temperature. The optimal pH for toxin production except P. variotti was 6.5. Also, toxin production was not greatly influenced by pH.

• Korean Journal of Animal Reproduction
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• v.21 no.4
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• pp.405-409
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• 1997

This study was carried out to investigate the general characteristics such as semen volume, pH, sperm motility and sperm concentration of the semen collected from Korean Jindo dogs by the mothod of Digital manipulation of penis, and the effect of temperature and preservation time on motility of fresh semen. Multiple ejaculates were collected from four male Korean Jindo dogs. The results obtained in this experiment were as follows : 1. Average semen volume per ejaculate, semen pH, sperm motility and sperm concentration of the second fraction and the small volume of third fraction from the ejaculate were 3.29ml, 6.30, 96.70% and 1.64$\times$108 cells/ml, respectively. 2. Average semen volume per ejaculate, semen pH, sperm motility and sperm concentration of the first fraction from the ejaculate were 1.16ml, 6.10, 6.67% and 5.07$\times$105cells/ml. Average semen volume per ejaculate, semen pH, sperm motility and sperm concentration of the second fraction from the ejaculate were 2.30ml, 6.33, 97.66% and 1.92$\times$108cells/ml. Average semen volume per ejaculate, semen pH, sperm motility and sperm concentration of the third fraction from the ejaculate were 3.24ml, 6.51, 93.33% and 3.13$\times$107cells/ml. 3. Motility of fresh semen during preservation were higher at 17$^{\circ}C$ than at 5$^{\circ}C$ or 36$^{\circ}C$. When preservation temeprature was 17$^{\circ}C$, motility were 95.75% at 1 h, 90.00% at 6 h, 84.25% at 12 h, 68.00% at 18 h, 36.25% at 24 h and 28.75% at 30 h, respectively.

• Journal of fish pathology
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• v.35 no.1
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• pp.93-102
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• 2022

This study performed a trichlorfon (TCF) residue and pharmacokinetic analysis with Japanese eels, Anguilla japonica, to obtain baseline data to establish the maximum residue level (MRL) of TCF in A. japonica. After dipping A. japonica in 30 ppm and 150 ppm of TCF at 28℃ and 18℃, drug residue in the body was analyzed with LC-MS/MS, and these results were further analyzed with the PK solver program to obtain the pharmacokinetic parameters of TCF in the serum, muscles, and liver. The maximum concentrations (C_max) in the serum, muscles, and liver were 25.87-357.42, 129.91-1043.73, and 40.47-375.20, respectively, and the time to maximum concentration (T_max) was 0.13-1.32h, 1.17-3.34h, and 0.14-5.40h, respectively. The terminal elimination half-life (T_1/2) was 2.13-3.92h, 5.30-10.35h, and 0.65-13.81h, respectively. In the 30 mg/L concentration group, TCF was not detected in the serum of eels 96 hours after bathing, and was below the detection limit after 336 hours in muscle and liver. On the other hand, in the 150 mg/L concentration group, TCF was not detected in the serum of eels 336 hours after bathing, but was detected in muscle and liver at 336 hours. In conclusion, the results of this study would be useful in establishing the MRL of TCF in farmed A. japonica.

• Toxicological Research
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• v.17 no.4
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• pp.287-296
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• 2001

The acute oral LD5O toxicity values of isazofos, pyraclofos, diazinon and methomyl were determined for Japanese quail based on OECD guideline. The $LD_{50}$ of isazofos, pyraclofos and diazinon was 16.26 mg/kg, and 7.11mg/kg body weight In female respectively. And the $LD_{50}$ of each chemical in male was 21.44, 35.64, 8.28 mg/kg body weight respectively. Diazinon was the most susceptible compounds to Japanese quail in both sexes. The $LD_{50}$ of methomyl was 21.24 mg/kg body weights in female, and 28.28 mg/kg body weight in male respectively. Diazinon, isazofos and methomyl were more toxic In the female than male. The symptoms of poisoning were similar in quails administrated with each chemicals. The clinical sign in Japanese quail were ataxia, salivation, diarrhea, ruffled feather and convulsion at dead point. There were severe hemorrhage and catarrhal inflammation from duodenum to ileum In all compounds. In Japanese quail treated with organophosphorus and carbamate compounds, brain acetylcholinesterase was inhibited by 88-96. The recovery was not observed after 5 h in sublethal dose.

• Bulletin of the Korean Chemical Society
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• v.30 no.5
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• pp.1047-1053
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• 2009

The future use of hydrogen as an energy source is expected to increase on account of its environmentally friendliness. In order to enhance the production of hydrogen, Pd ions (0.01, 0.05, 0.1, and 0.5 mol%) were incorporated $TiO_2$ (Pd-$TiO_2$) and used as a photocatalyst. The UV-visible absorbance decreased with increasing level of palladium incorporation without a wavelength shift. Although all the absorption plots showed excitation characteristics, there was an asymmetric tail observed towards a higher wavelength caused by scattering. However, the intensity of the photoluminescence (PL) curves of Pd-$TiO_2$ was smaller, with the smallest case being observed at 0.1 and 0.5 mol% Pd-$TiO_2$, which was attributedto recombination between the excited electrons and holes. Based on these optical characteristics, the evolution of $H_2$ from methanol/water (1:1) photo-splitting over Pd-$TiO_2$ in the liquid system was enhanced, compared with that over pure $TiO_2$. In particular, 2.4 mL of $H_2$ gas was produced after 8 h when 0.5 g of a 1.0 mol% Pd-$TiO_2$ catalyst was used. $H_2$ was stably evolved even after 28 h without catalytic deactivation, and the amount of $H_2$ produced reached 14.5 mL after 28 h. This is in contrast to the case of the Pd 0.1 mol% impregnated $TiO_2$ of $H_2$ evolution of 17.5 mL due to the more decreasedelectron-hole recombination.

• International Journal of Industrial Entomology and Biomaterials
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• v.17 no.2
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• pp.173-180
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• 2008

The influence of temperature and relative humidity in infection and cross-infection of Nosema bombycis and N. mylitta respectively in mulberry silkworm, Bombyx mori L. on larval mortality, multiplication of pathogens, larval weight and growth rate in three different seasons were studied. Seasons were selected in such condition, when very less fluctuations between minimum and maximum temperature and minimum and maximum relative humidity ($25{\sim}28^{\circ}C$ and $65{\sim}72%$ R.H) was observed i.e., season-1. Fluctuations between minimum and maximum temperature were less ($28.05{\sim}34.50^{\circ}C$) but R.H % was more ($55{\sim}81%$) in season-2. Fluctuations between minimum and maximum temperature and R.H % were more ($20.00{\sim}40.5^{\circ}C$ and $64.00{\sim}90.00%$) in season-3. Growth rate of microsporidian-infected silkworm is directly related to the prevailing temperature and relative humidity in silkworm. Silkworm can tolerate slight variation of temperature but slight variation of relative humidity disfavours the development of silkworm and favours the multiplication of pathogens.

• KSBB Journal
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• v.28 no.5
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• pp.282-286
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• 2013

The seaweed, Gelidium amansii, was fermented to produce bioethanol. Optimal pretreatment condition was determined as 94 mM $H_2SO_4$ and 8% (w/v) seaweed slurry at $121^{\circ}C$ for 60 min. The mono sugars of 40.4 g/L with 67% of conversion from total carbohydrate of 60.6 g/L with 80 g dw/L G. amansii slurry were obtained by thermal acid hydrolysis pretreatment and enzymatic saccharification. G. amansii hydrolysate was used as the substrate for ethanol production by Kluyveromyces marxianus KCTC 7150 and Candida tropicalis KCTC 7212 using 5L fermentor. The ethanol productions by K. marxianus KCTC 7150 and C. tropicalis KCTC 7212 were 17.8 g/L with $Y_{EtOH}$ of 0.48 at 120 h and 19.3 g/L with $Y_{EtOH}$ of 0.50 at 120 h, respectively.

• Journal of the Korean Applied Science and Technology
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• v.28 no.2
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• pp.251-257
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• 2011

The processes for the preparation of ZnO powder by using EAF(electric arc furnace)dust was studied by wetting method which are divided to two steps, carried out of the elution processes by various concentrations of sulfuric acid is reacted with EAF dust as the former, and the latter were performed by a number of specified processes, which are leaching process depends on various pH, cementation, ozone and heat treatment processes etc. Experimental results showed that the appropriate pH range is pH7.5~8.0 and the resulting zinc content is range of 37~38%, the residual quantities of the heavy metals are less than 3ppm individually by cementation process except Mn, even though the Mn metal could not be removed by cementation process but was removed up to 0.2ppm by the ozone process from 70ppm initially. Finally, 80.2% of ZnO was obtained by the heat treatment at $500^{\circ}C$.