• Particle and aerosol research
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• v.18 no.2
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• pp.37-50
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• 2022

Due to the syndrome coronavirus 2 (SARS-CoV-2) pandemic, the subway passenger cabin should be continuously sterilized. However, a disinfectant such as chlorine is toxic and can lead to different issues to human health. In this paper, we introduced a novel disinfectant based on natural product (Dendropanax morbifera extract). Via ultra-high performance liquid chromatography - mass spectrometer (UHPLC-MS), different compounds from Dendropanax morbifera extract showed antivirus potentials. Antimicrobial experiments confirmed that the air-disinfectant containing Dendropanax morbifera can eliminate harmful microorganisms including Gram (-), Gram (+), and yeast within 5 mins. The as-prepared air-disinfectant also showed high antivirus activity against H1N1, HRV, and EV71. Deodorization test also indicates that the as-prepared air-disinfectant can lower the harmful gas such as ammonia and trimethylamine in the atmosphere. To evaluate the potential of air-disinfectant containing Dendropanax morbifera in practical applications, different safety tests including acute oral toxicity, acute skin irritation, and eye irritation were conducted. Results showed that the as-prepared disinfectant did not negatively affect tested animals during these safety investigations.

• Nuclear Engineering and Technology
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• v.55 no.2
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• pp.580-586
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• 2023

Diversified fuel types such as methanol, hydrogen, liquefied natural gas, ammonia, biofuels, have been come to fore in consideration of the limitations, regulations, environmental perception and efficient use of resources on maritime sector. NE is described as a substantial alternative energy source on the marine vessels in the sense of de-carbonization and fuel efficiency activities carried out by IMO. Although NPVs have been constructed for the merchant, navy and supply fields over the years, their numbers are few and working ranges are quite limited. NE generation techniques, reactor types, safety and security issues in case of any leakage or radiation pollution are analyzed and comparisons are performed between fossil-based fueled and NP based on icebreakers. The comparison are conducted on the basis of dimensions, resistances and operational competences by the VIKOR. NP icebreakers operated in recent years occupy a notable position in the ranking, although fossil fueled ones are most prevalent. Consequently, refueling period and emissions are the principal benefits of NPVs. Nevertheless, the use of such systems on marine vessels especially for merchant ships may come to the fore when all concerns in terms of safety, security and society are resolved since the slightest mistake can have irreversible consequences.

• Journal of The Korean Society of Agricultural Engineers
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• v.65 no.1
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• pp.61-72
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• 2023

The increase in the rearing intensity of pigs has caused deterioration in the pig house's internal environment such as temperature, humidity, ammonia gas, and so on. Traditionally, the widely used method to control the internal environment was through the manipulation of the ventilation system. However, the conventional ventilation system had a limitation to control the internal environment, prevent livestock disease, save energy, and reduce odor emission. To overcome this problem, the air-recirculated ventilation system was suggested. This system has a semi-closed loop ventilation type. For designing this system, it was essential to evaluate the ventilation rates considering the pressure loss of ducts. Therefore, in this study, pressure loss calculation and experiment were conducted for the quantitative ventilation design of a semi-closed loop system. The results of the experiment showed that the inlet through which external air flows should always be opened. In addition, it was also found that for the optimum design of the semi-closed loop ventilation system, it was appropriate to install a damper or a backflow prevention device rather than a ventilation fan.

• Journal of the Korea Organic Resources Recycling Association
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• v.18 no.3
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• pp.38-49
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• 2010

The technology of anaerobic digestion of organic wastes has been researched for the production of biogas in various purposes. Biogas comes from anaerobic digestion and landfill in which that of main components are methane and carbon dioxide containing small amount of hydrogen sulfide and ammonia. Biogas can either be used directly on the site where it is generated after proper upgrading or distributed to external customer via separate pipelines like natural gas. There are four basic ways biogas can be utilized such as production of heat and steam, electricity production, vehicle fuel and production of chemicals. There is no international technical standard for biogas use but some countries have developed national standards and procedures for biogas use. In this paper, technical standards of biogas depending on purpose have reviewed for the several countries.

• Journal of Animal Science and Technology
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• v.51 no.5
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• pp.369-378
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• 2009

Protein fractionation was evaluated from whole crop silages of rye (RS), wheat (WS), triticale (TS), oat (OS), barley (BS), and rice straw silage (RSS), and in vitro trial was carried out to examine the effect of silage and extraction of soluble protein on fermentation characteristics, total gas production and degradation. Soluble protein of silages was extracted with borate-phosphate buffer, and fermentation characteristics, gas production and degradation of silages were estimated by incubating anaerobically the mixed solution of strained rumen fluid and artificial saliva (1:1, v/v) containing dried and ground silages placed in nylon bag at $39^{\circ}C$ up to 48h. Soluble protein (SP) content was lowest for RSS as 2.11% in total CP compared to those for other silages. Highest A fraction (NPN) was observed from RS (74.33% of total CP) while those from TS and RSS were relatively low (48%). B2 fraction was relatively higher for RS, RSS and WS than for TS and BS. $B_3$ fraction was lowest in WS among silages. C fraction (27.07) in RSS was higher than in other silages (1.40~9.93%). pH in incubation solution was increased (P<0.01~P<0.001) for extracted silages up to 12h but decreased (P<0.01) at 48h for non-extracted ones. Contents of ammonia-N (P<0.001) and total VFA (P<0.01~P<0.001) were higher for non-extracted silages than for extracted ones. Acetate proportion was increased (P<0.001) in buffer extracted silages while those of propionate and butyrate were decreased (P<0.001) up to 24h incubation. Increased (P<0.001) total gas production was obtained from non-extracted silages up to 12h while gas production was increased (P<0.01) in extracted ones thereafter. In vitro degradation of dry matter and CP was increased (P<0.001) in non-extracted silages but that of neutral detergent fiber was increased (P<0.001) in extracted ones without difference among silages. Difference in mean values of degradability for each silage prior to- and post extraction with borate buffer, however, was not found among silages. It may be concluded that high NPN content of silages may reduce the protein availability in silages and borate buffer soluble components in silages can stimulate the early stage of fermentation.

• Korean Journal of Poultry Science
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• v.30 no.3
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• pp.151-159
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• 2003

Two experiments were carried out to evaluate the effects of feeding Aspergillus oryzae(AO) ferment on performance, intestinal microflora, serum components, ammonia generation and litter dampness in broiler chicks. In experiment I, three hundred sixty, one day old broiler chicks, Abor Acres, were fed 0 and 0.1% of Aspergiilus oryzae short conidia ferment(AOS) and 0.1% of Aspergillus oryzae long conidia ferment(AOL) for five weeks. In experiment II, three hundred sixty, one day old broiler chicks, Abor Acres were fed 0, 0.1 and 0.2% of Aspergillus oryzae long conidia ferment(AOL) for five weeks. In experiment I, growth rates were not statistically different among dietary treatments. AOS and AOL showed increased tendency in weight gain and feed intake compared to those of control, whereas feed conversion was not different. Litter dampness of AOS and AOL was also tended to decrease compared to that of control, but was not significantly different. Fecal ammonia gas generation was decreased in feeding AOS and AOL, and maintained 1/2 to 3/4 compared to the control. In serum metabolites, AOS and AOL increased glucose and calcium, and decreased total protein, blood urea nitrogen and total cholesterol. In experiment II, body weight of chicks fed 0.1 and 0.2% AOL were heavier than the control(P<0.05). Feed intake of chicks fed 0.1 and 0.2% AOL also were higher than the none, but feed conversion ratio was not different among treatments. Ileal and cecal microflora showed increased tendency in lactic acid bacteria compared to those of the control. Salmonella and E. coli were decreased in ileum of chicks fed 0.1 and 0.2% AOL. In conclusion, feeding AO ferment increased growth performance and improved intestinal microflora of broiler chicks and environments of broiler house.

• Journal of The Korean Society of Grassland and Forage Science
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• v.31 no.2
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• pp.177-190
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• 2011

This study was conducted to determine effects of dietary herbaceous peat on in vitro fermentation and milk production in dairy cows. Ruminal pH, gas production, VFA (volatile fatty acid), Ammonia-N, and rumen degradability were examined by the addition of three times over 0, 1, and 5% herbaceous peat with substrate of timothy hay, and the change of rumen fermentation characteristics were evaluated. In 0, 3, 12 and 24 hours cultivation, all treatments did not show a significant difference but the control at 6 hours appeared significantly lower pH compared to 1 and 5% treatments (p<0.05). The gas production of the treatments significantly increased until 12 hours of cultivation compared to control (p<0.05), the rumen ammonia concentration showed a tendency to increase until 24 hours in all treatment groups, and there was no significant difference between treatments. About the rumen degradability, 5% treatment showed higher rumen degradability in all hours than control and 1% treatment (p<0.05). Meanwhile, for in vivo trial, 16 heads of Holstein lactation dairy cows were selected for experiment for four weeks in order to research the change of milk yield, milk compositions and change of somatic cell counts of lactation dairy cows by herbaceous peat feeding. The milk yield of vitamin C and herbaceous peat treatments (T3) was 25.0 kg but the control was 23.2 kg, herbaceous peat treatment (T1) was 23.1 kg, and vitamin C treatment (T2) was 23.4 kg, so there was linear increase effect of milk yield by T3. The partial significance of the milk (fat, milk protein, lactose, MUN and SNF) and change of somatic cell count before and after experiment by the control and treatments about change of milk and somatic cell counts (p<0.05) were recognized. About change of milk in the first half (1~2 weeks) and latter half (3~4 weeks) during four weeks of experiments period, the herbaceous peat supplement treatments showed a tendency of significant decrease of quality of milk protein and SNF. The control and treatments did not show significant change of blood nutrients (total protein, cholesterol, NEFA, BUN), liver function component (AST, GGT) and minerals (Ca, P, Mg) before and after experiment. In summary, it is judged that herbaceous peat feeding for lactation dairy cows would be recommendable based on the results of milk, somatic cell count physiologically.

• Journal of Animal Science and Technology
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• v.45 no.4
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• pp.551-558
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• 2003

This study was conducted to investigate the effect of dietary wormwood powder (Artemisia montana Pampan; WP) supplementation on growing performance and fecal noxious gas emission in weanling pigs. One hundred and twelve pigs were alloted into four treatments and offered for 4 weeks one of the diets supplemented with 0% (control), 0.5% (0.5), 1.0% (1.0) and 2.0% (2.0) WP. Each treatments has four replicate with 7 pigs per replicate. ADG, ADFI and F/G were improved by 1.0 and 2.0 WP supplementation during 0d${\sim}$14d feeding. Feed intake of 1.0 WP diet was higher (P<0.05) than any other diet during 15d${\sim}$28d feeding. But there were no differences among the other treatments in the weight gain and feed conversion. During the whole feeding period, daily weight gain and feed intake of pigs fed 1.0 and 2.0 treatments were higher than those of pigs fed control and 0.5 diet. DM digestibility was significantly (P<0.05) higher in weanling pigs fed 0.5, 1.0 and 2.0 WP than that of the control. The protein digestibility was significantly improved in 1.0 WP treatment and the phosphorus digestibility was improved in 2.0 WP treatment. Excretion of nitrogen and phosphorus was significantly (P<0.05) decreased by 2.0 treatment than control. Emission of fecal ammonia after 48 hours storage in vinyl bag dramatically decreased by all the treatments except control. However, there was no statistical difference in fecal hydrogen sulfide emission among treatments. In conclusion, this study suggested that the dietary 1.0${\sim}$2.0 supplementation of WP can improve productivity of pigs decrease fecal $NH_3$ and $H_2S$ gas emission.

• Journal of Korean Society of Environmental Engineers
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• v.27 no.6
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• pp.590-598
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• 2005

An adequate method to identify chromium separation, Cr(III) and Cr(VI), in water samples were studied by using High Performance Liquid Chromatography(HPLC) coupled with Inductively Coupled Plasma Mass Spectometer(ICP-MS) equipped with Dynamic Reaction Cell(DRC). The characteristic distribution of Cr(III) and Cr(VI) in the raw water taken at the six water intake stations in Seoul, was analyzed by the method developed by the authors. The chromium species separated by HPLC was isocratically conducted by using tetrabutylammonium phosphate monobasic(1.0 mM TBAP), ethylenediaminetetraacetic acid(0.6 mM EDTA) and 2% v/v methanol as the mobile phase. 5% v/v methanol was used as flushing solvent. A reactive ammonia($NH_3$) gas was used to eliminate the potential interference of $ArC^+$. Several Parameters such as solvent ratio, pH, flow rate and sample injection volume were optimized for the successful separation and reproducibility. Although it has been reported thai the separation sensitivity of Cr(III) is superior to that of Cr(VI), the authors observed Cr(VI) was more sensitive than Cr(III) when ammonia($NH_3$) gas was used as the reaction gas. It took less than 3 minutes to analyze chromium species with this method and the estimated detection limits were $0.061\;{\mu}g/L$ for Cr(III) and $0.052\;{\mu}g/L$, for Cr(VI). According to the results from the analysis on chromium species in the raw water of the six intake stations, the concentrations of Cr(III) ranged from 0.048 to $0.064\;{\mu}g/L$(ave. $0.054\;{\mu}g/L$) while that of Cr(VI) ranged from 0.014 to $0.023\;{\mu}g/L$(ave. $0.019\;{\mu}g/L$). Recovery ratio was very high($90.1{\sim}94.1%$). There were two or three times more Cr(III) than Cr(VI) in the raw water.

• Journal of Animal Environmental Science
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• v.16 no.2
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• pp.99-108
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• 2010

The principal objective of this study was to investigate the cooling effects of geothermal heat pump system (GHPS) in farrowing house. A total of 96 sows were allocated to 2 pig housings (GHPS and conventional housing) with 48 for four weeks in summer season. During the experimental period of four weeks, the highest outside temperature observed was approximately $34.1^{\circ}C$, GHPS decrease indoor temperature of pig housing up to $30.9^{\circ}C$, but conventional pig housing was similar to outside temperature. Dust concentrations (maximum 61.4%) of particulate matter less than $10{\mu}m$ (PM 10) in GHPS-housing were lower than the conventional housing. GHPS showed no signigicant difference in carbon dioxide emission, whereas the ammonia gas concentration was significantly decreased in GHPS-housing compared to that of conventional housing. Sows in GHPS-housing showed significantly lower respiratory rate than those of the control group. GHPS did not affect hormone level, litter size and birth weight, but weaning weight of piglets was influenced by GHPS. Feed consumption of sows was significantly increased in GHPS-housing compared to the conventional hosing. These results suggest that GHPS decrease dust concentration, ammonia gas emission and indoor temperature of pig housing and may affect performance in sows and weaned piglets.