• Journal of the Korean Society of Marine Environment & Safety
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• v.26 no.6
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• pp.751-758
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• 2020

SCR technology, which uses urea-water as a NO_x reducing agent, has been widely used to reduce NO_x in marine diesel engines. However, as an alternative NO_x reducing agent, solid-phase ammonium carbamate has several advantages, such as low-temperature NO_x reduction performance and NH₃ storage capacity. This study presents a method for evaluating the purity of ammonium carbamate using EA, FTIR, and XRD to investigate the change in the material characteristics of ammonium carbamate when it is exposed to various temperature and pressure conditions. In this study, it was found that the purity of ammonium carbamate can be effectively evaluated via EA analysis. The FTIR analysis results confirmed that the properties of ammonium carbamate did not change even after repeated heating and cooling under thermal decomposition temperature conditions, which may be applied to the SCR system of marine diesel engines. Additionally, it was found that when ammonium carbamate was exposed to the atmosphere for a long time, it transformed into ammonium carbonate.

• Journal of Veterinary Clinics
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• v.16 no.2
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• pp.375-380
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• 1999

This study was conducted to develop an intrauterine inseminator (IUI) to deposit of frozen semen into uterus and to evaluate the results obtained after artificial insemination by IUI. Two Japanese spitzs (2 to 4 years of age) were used as semen donors. Semen was collected by manual masturbation into sterile glass collection tubes and separated into 3 fractions with only the sperm-rich fractions retained for further examination. Sperm motility >70%, sperm concentration of 200 to $400{\times}10^6 cells/ml$$\times$g for 5 min and poured out the suspended solution, and then diluted with 2 ml Tris-buffer which was consisted of 2.4 g Tris, 1.4 g citric acid, 0.8 g glucose, 0.1 $\mu\textrm{g}$/ml streptomycin, 100 IU/ml penicillin, 20 ml egg yolk to 100 ml mili-Q water (Ext I) or supplemented with 8 ml glycerol and 1 ml Equex STM paste to 100 rnl (Ext II). The diluted semen was cooled to 5$^{\circ}C$ in cold room, where the temperature in the sample reached 5$^{\circ}C$. Two h after beginning the cooling procedure, 2 ml of Ext II, also at 5$^{\circ}C$, was added and mixed by gently reversing the tubes several times during 1 h. The final sperm concentration for freezing was approximately $50{\times}10^6 cells/ml$. After equilibration, the semen was loaded into 0.5 ml straw and frozen on the liquid nitrogen vapour in styrofoam box. The straws were thawed at 7$0^{\circ}C$ for precisely 6 sec. After thawing of each straw, the frozen semen can survived over 50% motility. All the females were inseminated twice with 1 ml of $25{\times}10^6 cells/ml$

• Korean Journal of Food Science and Technology
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• v.34 no.3
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• pp.400-406
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• 2002

In case of doenjang, solution of browning problem might be an important remedy in order to dissolve consumers' dissatisfaction, therefore this study was performed to develop traditional doenjang which has improved in color aspect for consumers' needs. Physicochemical compositions and color values of commercialized traditional doenjang which was processed by history references of our country, were analyzed. doenjang used as samples were processed with traditional meju, which were made with soybean and mixed with various rates after following process such as soaking, steaming, cooling, chopping and grinding. The doenjang processed were storaged at $30^{\circ}C$ for 27 days, and their amino-N, pH, color values and sensory evaluation were analyzed with fermentation period. Furthermore, nitrogen results analyzed were compared with that of commercialized traditional doenjang. In the comparison with control, treated with only traditional meju, and doenjang treatments processed with different mixing rates of traditional meju and steamed soybean, the content of amino-N in control were higher than the others, and the contents of amino-N decreased with increasing contents of steamed soybean. Their pH were changed weak alkalic region into weak acidic region with fermentation period. In the aspect of color, traditional doenjang having the rate of traditional meju and steamed soybean (1:4) was most improved and also, in comparison of result of sensory evaluation with commercial traditional doenjang, its color, taste and falvor were evaluated predominent, therefore it might be thought to have competition on the market.

• Proceedings of the Korean Society of Embryo Transfer Conference
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• 2002.11a
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• pp.92-92
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• 2002

Considerable attention has been focused on the cryopreservation of semen and estrus induction in dog, as consequence of poor productivity caused by long anestrus period, in order to enhance the productivity of youngs and to preserve the breeds. The objectives of this study were to evaluate semen quality after cryopreservation and to evaluate the Pregnancy rate after insemination (AI). Fifty infertilie dogs (age 2∼3 years) were selected for the study and divided into three different estrus induction treatment groups. Group 1: dogs (n=15) were given clomifene (0.1 mg/kg) orally for five days at 12 hr intervals. Group 2: dogs (n=15) were given bromocriptine (50 $\mu\textrm{g}$/kg) orally for five days at 12 hr intervals, followed by single injection intravenously of 500 IU GnRH (Group 3, n=20) when pro-estrus occurred. The rates of pregnancy in estrus inducted dogs mated naturally compared to those inseminated artificially with ejaculated fresh semen and frozen-thawed semen. Estrus detection was performed using the method of vaginal smear and confirmed by the plasma progesterone assay. The ejaculated semen to freeze was exposed to a mixture of Tris extender with cryoprotectant (Trisma, 81 mM: TES, 209 mM: citric acid, 6 mM; glucose, 5 mM; glycerol, 8%) and cryopreserved gradually by slow-cooling at 17 cm above the surface of liquid nitrogen (LN$_2$) for 23 min. The motility of frozen-thawed spermatozoa was assessed by phase-contrast microscopy. To assess their viability and acrosome content, spermatozoa were stained with a vital stain and Fluorescence conjugated lectin Pisum Savitum Agglutinin (FITC/PAS), respectively. Pregnancy was confirmed by ultrasonograpy on day 25, 35 and 55 post insemination. The use of fresh semen, the pregnancy rates were observed 66.6, 66.6, 75.0 and 83.3% in natural estrus, clomifene induced, bromocriptine induced and a combination of GnRH and bromocriptine, respectively. The use of frozen-thawed semen, the pregnancy rates were observed 66.6, 33.3, 50.0 and 60.0% in natural estrus, clomifene induced, bromocriptine induced and a combination of GnRH and bromocriptine, respectively. No difference was observed in the number of offspring produced among natural estrus and treated groups inseminated with fresh or frozen-thawed semen. In conclusion, the pregnancy rate of dogs treated with a combination of GnRH and bromocriptine was more effective than use of clomifene or bromocriptine only. In addition, frozen-thawed semen can be used successfully far artificial insemination in dog.

• Journal of Animal Science and Technology
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• v.48 no.6
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• pp.797-804
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• 2006

The present study was undertaken to investigate the post-thawed survivability of bovine embryo depending on different dose of ethylene glycol and sucrose. Ovaries were collected at local slaughterhouse and the cumulus-oocyte-complexes aspirated from ovaries were in vitro matured, fertilized and cultured at 39°C in an atmosphere of 5% CO2 incubator. For conventional slow-freezing, d 7 or 8 expanded blastocysts were collected. Embryos were equilibrated in 1.5 M and 1.8 M ethylene glycol(EG) with 0.1 M and 0.3 M sucrose in Dulbecco's phosphate-buffered saline(D-PBS) supplemented with 0.5% bovine serum albumin. Embryos were then loaded individually into 0.25ml-straw and placed directly into cooling chamber of programmable freezer precooled to 󰠏7°C, after 2 min, the straw was seeded, maintained at 󰠏7°C for 8 min, and then cooled to 󰠏35°C at 0.3°C/min, plunged and stored in liquid nitrogen for at least 3 days. For thawing, the straw containing embryos were warmed in air for 10 sec and exposed to 37°C water for 20 sec. Straws were then removed from 37°C water. Rates of blastocyst survive and hatching were evaluated at 24 to 72 h post-warming. No difference of the survivability was shown between 1.5 M and 1.8 M EG (71 and 70%, respectively). Addition of 0.1 M sucrose to 1.5 M and 1.8 M ethylene glycol in the freezing solution did not differ significantly embryo survival (74 and 77%, respectively), whereas survival rates was higher(89%) in freezing solution contained 0.3M sucrose to 1.8M EG compared with 0.3M sucrose to 1.5M EG group(71%). However, there was no difference in the overall total cell number between the two groups (122±1.8 vs 131±1.4, respectively). In conclusion, the results suggest that 0.3 M sucrose in 1.8 M EG may be optimal condition for freezing and thawing methods with in vitro produced embryos and may be applied to on-farm conditions for embryo transfer.

• Journal of Veterinary Clinics
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• v.24 no.4
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• pp.486-492
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• 2007

Seminal plasma(SP) is usually removed from semen that is to be cryopreserved. However, some reports indicate that SP has beneficial effects on spermatozoa during chilling and freezing. The purpose of this study was to determine the effect of SP on sperm survival by adding SP to the extender before cooling and freezing canine spermatozoa. In replicate experiments, ejaculates obtained from four healthy dogs(1-4 years old) of various breeds were pooled, centrifuged at $300{\times}g$ for 10 min at $25^{\circ}C$, and the supernatant of seminal plasma was decanted. Spermatozoa were suspended in egg yolk-Tris(EYT) buffer. The study comprised two experiments: [Exp 1] Sperm were suspended in EYT extender containing either 0, 20, 40, 80 or 100% SP and were slowly cooled to $4^{\circ}C$ for 2h or held at $25^{\circ}C$ as controls. Sperm concentration was adjusted to $2{\times}10^8/ml$. [Exp II] Sperm samples, each of which contained $1{\times}10^8/ml$, were assigned to nine groups to be frozen. In the first four groups, sperm in EYT containing either 20, 40, 80 or 100% SP were cooled to $4^{\circ}C$, then diluted to contain final concentrations of EYT+0.6M glycerol and then were frozen. The final concentrations of SP were 10, 20, 40 or 50%. In the other four groups, sperm in EYT alone were first cooled slowly to $4^{\circ}C$, then diluted to contain final concentrations of EYT+0.6M glycerol plus 10, 20, 40 or 50% SP and then were frozen. Spermatozoa, which chilled in EYT alone and diluted to contain final concentrations of EYT+0.6M glycerol without seminal plasma, and then frozen, was regarded as control. Spermatozoa were frozen at $25^{\circ}C/min$ of cooling rate in plastic straws that were suspended above liquid nitrogen and thawed in water at $38^{\circ}C$ for 1 min. Sperm survival was assayed by determining progressive motility and integrity of plasma and acrosome membranes. Progressive motility was determined by microscopic examination at $200{\times}$ magnification. Membrane integrity was assessed by use of a double fluorescent dye, and acrosome integrity by staining sperm with Pisum sativum agglutinin. The results of the first experiment showed that adding SP did not improve motility of spermatozoa compared to those incubated without SP regardless of temperature. The results of the second experiment showed that spermatozoa suspended in EYT+0.6M glycerol containing SP exhibited the higher progressive motility before being frozen(P<0.05). However, frozen-thawed spermatozoa that had suspended in EYT+0.6M glycerol containing SP showed the similar or lower viability(P<0.05). In summary, although seminal plasma did not affect spermatozoa that were chilled in EYT without cryoprotectant(CPA), addition of seminal plasma to EYT containing CPA did significantly improved progressive motility of canine spermatozoa that were chilled.

• Korean Journal of Animal Reproduction
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• v.23 no.1
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• pp.75-84
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• 1999

This study assessed development in vitro of pronuclear(PN) stage embryos cryopreserved by the method of either vitrification or slow freezing, by using of different cryoprotectants, and equilibration and cooling rate, in rabbit. Ethyleneglycol- ficoll- sucrose(EFS) or ethyleneglycol- polyvinylpyrrolidone - galactose- (EPG-I) for vitrification, and EPG- II for slow freezing as cryoprotectant were used. The pronuclear embryos were exposed to EFS for 0 to 5 min and diluted with D-PBS and/or pre-dilution with 0.5 M sucrose. To examine the viability of frozen-thawed embryos, PN embryos were co-cultured with bovine oviductal epitherial cell(BOEC) for 5 days to hatching blastocyst stage in 39 $^{\circ}C$ 5% $CO_2$incubator. The results obtained were as follows: The dilution with 0.5 M sucrose and D-PBS after the exposure to EFS for 1.0 min resulted in no significant(P＜0.05) decrease in the development of PN embryos to hatching blastocyst(72.0%), compared with controls. The development of PN embryos cryopreserved to hatching blastocyst was not significantly (P＜0.05) different between EFS for 1.0 min(72.0%), EPG-I for 1.0 min(72.0%) and EPG-II for 30 min(66. 7%). The post-thaw development of PN embryos to hatching blastocyst was similarly very low as 6.1% and 11.5% in vitrification with EFS and slow freezing with EPG-II, respectively. The incidence of post-thaw zona-crack in PN embryos cryopreserved by slow freezing with plunging to liquid nitrogen at －35$^{\circ}C$ was signicantly(P＜0.05) higher(25.0%), compared with －85$^{\circ}C$ (1.9%). These results indicated that the rabbit PN embryos could be cryopreserved with either vitrification or slow freezing procedure, and frozen PN embryos could be successfully developed in vitro to haching blastocyst. but the post-thaw development of cryopreserved PN embryos was still very low under the present conditions.

• Journal of The Korean Society of Grassland and Forage Science
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• v.29 no.1
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• pp.51-62
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• 2009

This study was carried out development a new composting system to lower copper and zinc concentration in plg sludge compost and conduct an inquiry into the possibility of crop cultivation. The concentrations of nitrogen, phosphorus and pH averaged 4.4%, 6.3% and 7.57, respectively, which were higher concentrations than in commercial organic fertilizers, and the concentrations of copper and zinc averaged 805 and 1,704 mg/kg, respectively, which were beyond the heavy metal concentration limit in byproduct compost. Hydrated citric acid I lowered the concentrations of copper and zinc by 58% and 97%, respectively and hydrated oxalic acid II lowered the concentrations of copper and zinc by 48% and 56%, respectively in pig sludge compost. Lower concentrations of copper and zinc in pig sludge resulted from the enhanced hydrated-citric acid concentration in organic acid solution mixed with distilled water. The concentrations of copper and zinc were 330, and 41 mg/kg in the pig sludge treated with 100% hydrated citric acid. Agitation composting system stabilized the compost earlier than the stationary composting system, in which the stabilization condition was confirmed by higher temperature by $4^{\circ}C$ at highest temperature and 7 days earlier cooling down after highest temperature. The levels of germination index (G.I) 80 were obtained 15 and 20 days after composting in agitation and stationary composting system, respectively. The concentrations of copper and zinc were 2.4 and 4.26 mg/kg respectively in soils amended with pig sludge compost after removing process of heavy metals by citric acid, but 8.0 and 22.37 mg/kg, respectively in soils amended with Pig Sludge. The concentrations of heavy metals was highest in com cultivated in soils amended with pig sludge. The copper and zinc concentrations In corn leaves were 75.2 and 50.56 mg/kg respectively, which were 4 and 2 fold higher than the com cultivated in soils amended with pig sludge compost after heavy metal removing process by hydrated citric acid.

• Food Science and Preservation
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• v.24 no.2
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• pp.168-180
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• 2017

This study was performed to determine the rapid thawing method for reducing the thawing time of frozen pork loins and to examine the effects of supercooling on the microbiological, physicochemical, and sensory qualities of fresh and frozen-thawed pork during storage at -1.5, 4, and $15^{\circ}C$. Forced-air thawing at $4^{\circ}C$ was the most time-consuming process, whereas radio frequency thawing time was the shortest by dielectric heating. The supercooling storage temperature was chosen to be $-1.5^{\circ}C$ because microstructural damages were not observed in the pork sample after cooling at $-1.5^{\circ}C$ for 24 h. Fresh or frozen-thawed pork loins stored at $-1.5^{\circ}C$ had lower drip loss and total volatile base nitrogen, thiobarbituric acid-reactive substance, and Hunter b* levels than loins stored at 4 and $15^{\circ}C$. In addition, the least degree of increase in preexisting microorganisms counts of the fresh or frozen-thawed pork loin samples was obtained during supercooled storage at $-1.5^{\circ}C$. Sensory quality results of fresh and frozen-thawed pork loin samples stored at $-1.5^{\circ}C$ showed higher scores than the samples stored at 4 and $15^{\circ}C$. These data indicate that supercooling at $-1.5^{\circ}C$ in the meat processing industry would be effective for maintaining the quality of pork meats without ice crystal nucleation and formation.

• Journal of Mushroom
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• v.3 no.4
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• pp.140-144
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• 2005

This study was conducted to verify the cause of suppression symptom in mycelial growth during summer and to be able to establish a countermeasure. Cultivation of Flammulina velutipes was experimented with varying elapsed time of 0, 3, 6, 9 hours after mixing the sawdust media and two kinds of water temperature (normal water, $24^{\circ}C$ and cold water, $6^{\circ}C$) for mixing sawdust media. There were trends of increased media temperature from $24^{\circ}C$ to $31^{\circ}C$ and decreased pH from 6.5 to 5.2~5.6 with varying elapsed time from mixing the media to sterilization. Bacterial density also increased with bacterial density in Medium $24^{\circ}C$ being 1.9~4.1 times higher than that in Medium 6. Growth of F. velutipes was delayed with dual culture of bacteria isolated from sawdust media. Total nitrogen content of sawdust media was lowered by elapsed time from mixing the media to sterilization. The use of normal water($24^{\circ}C$) delayed mushroom growth by 1~2 days compared with that of cold water($6^{\circ}C$). Furthermore, mycelial growth of F. velutipes in the bottle cultivation ceased 9 hours after mixing the media. Primordia formation of F. velutipes was delayed by 1~3 days by elapsed time after mixing sawdust media, while fruit-body yield decreased by 7~12% 6 hours after mixing the media. Fruit-body yield was more stabilized with the use of cold water($6^{\circ}C$) than with that of normal water($24^{\circ}C$). Results showed that it is effective to use cold water as low as $6^{\circ}C$ in mixing media for F. velutipes cultivation, especially during summer when environmental temperature is high, high pressure sterilization after bottling work can prevent bacterial propagation in the media and can stabilize media ingredient.