• International Journal of Advanced Culture Technology
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• v.4 no.1
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• pp.10-18
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• 2016

In the present study, a single cylinder four stroke dual fuel diesel engine was tested to investigate the performance and emission characteristics of various test fuels. The engine was tested in dual fuel mode using diesel and Karanja biodiesel blends as pilot fuel along with Natural gas as primary fuel with a constant gas flow rate under different loading conditions. From the experimentation it was found that smoke opacity and oxides of nitrogen (NOx) are at low level for all the prepared test fuels in dual fuel mode but the emissions of carbon monoxide (CO), carbon dioxide ($CO_2$) and hydrocarbon (HC) were found higher. In comparison to diesel fuel, by increasing the blend percentage different emission parameters are found to be reduced. At different loading conditions all the test fuels show poor performance in dual fuel mode of operation when compared with single mode of operation with diesel and biodiesel. With increase in gas flow rates, except (NOx) and smoke emissions, the other emission parameters like CO, HC and $CO_2$ values increased for all test fuels. Again, all blended fuels showed lower performance compared to diesel. The maximum pilot fuel savings for diesel was found decreasing with the increase in karanja biodiesel. From the present work it may be concluded that Karanja biodiesel with Natural gas in dual mode can be can used as promising alternative for diesel with some required engine modifications and further research must be carried out to minimize the emissions of CO, HC and $CO_2$.

• Korean Journal of Plant Resources
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• v.36 no.6
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• pp.571-579
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• 2023

In this study, cryopreservation by droplet-vitrification was applied to pear (Pyrus spp.) germplasm. We focused on the development and assessment of various strategies for the selection of suitable tissue, osmoprotection, and dehydration. We also evaluated post-thaw recovery of cryopreserved explants by droplet-vitrification. Preferentially, we tested the effects of preculture and loading treatments to determine which tissues were more suitable, either the apical shoot tips or the axillary buds. Apical shoot tips showed the better regrowth rate than in vitro axillary buds. The most effective techniques for cryopreservation were as follows. Shoots from in vitro seedlings which had been cultured for about 5-6 weeks were cold-hardened at 4℃ for one week, excised shoot tips were precultured on liquid MS medium including 0.3 M sucrose for 31 hours and 0.7 M sucrose for 17 hours, osmoprotected in loading solution (LS) for 40 min, and then cryoprotected in dehydration solution (PVS3) for 90 min. In addition, we found that regrowth rates of explants on regrowth medium after exposure to liquid nitrogen (LN) were higher than those on MS medium. Results indicated that the highest regrowth percentage was 95.6% for 'Bartlett' cultivar and 68.9% for 'BaeYun No.3' cultivar. Consequently, apical shoot tips of two pear cultivars, 'Bartlett' (P. communis) and 'BaeYun No.3' (P. pyrifolia), were successfully cryopreserved by droplet-vitrification. Results of this study show that the enhanced droplet-vitrification method described in the present study could be used as an effective means for long-term storage of pear genetic resources.

• Journal of Korean Society on Water Environment
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• v.34 no.1
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• pp.109-120
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• 2018

Sidestream in domestic wastewater treatment plants contains high concentration of ammonium, which increases nitrogen loading rate in the mainstream. The process for deammonification consisting of partial nitritation-anaerobic ammonium oxidation (ANAMMOX) and heterotrophic denitrification is an economical method of solving this problem. Currently, about 130 full-scale deammonification plants are fully operating around the world, but none is in Korea. In order to transfer the principal information about sidestream deammonification processes to researchers and operators, we summarized basic concepts, processes type, and key influence factors (e.g., concentration of nitrogen compounds, dissolved oxygen (DO), temperature, and pH). This review emphasis on the processes of single-stage sequencing batch reactor (SBR) deammonification, which are widely used as full-scale plants. Since simultaneous processes of partial nitritation, ANAMMOX and heterotrophic denitrification occur in a single reactor, the single-stage SBR deammonification requires appropriate control/monitoring strategies for several operating factors (DO and pH mostly) to achieve efficient and stable operation. In future, AB-process consisting of A-stage (energy harvesting from organics) and B-stage (ammonium removal without organics) will be applied to the wastewater treatment process. Thus, we suggest mainstream deammonification for B-stage connected with the sidestream deammonification as seeding source of ANAMMOX. We expect that many researchers will become more interested in the sidestream deammonification.

• Microbiology and Biotechnology Letters
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• v.18 no.5
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• pp.530-534
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• 1990

A strain of actinomycetes, Thermoactinomyces sp. CH-53, was isolated from manure and composted livestock feces. Actinornycetes-feed additive was prepared with the solid wheat bran medium of Thermoactinomyces sp. CH-53 that grew vigorously on unsterilized poultry feces at $50^{\circ}C$. pH 6.5- 9.5 and moisture content of 55-65% and added at a rate of 1% (wtlwt) to the commercially assorted feed to be fed poultry. The excreted feces contained $10^7-10^8$. Thermoactinomyces sp. CH-53 cells per gram. Poultry feces malodour was got rid of during treatment. The effect on plant growth was evaluated on the basis of the amount of nitrogen as fertilizer under a loading of 0.2g N1600g soillpot. A11 samples were showed a promotion effect for plant growth. The treated poultry feces added from O.lg to 0.4g total nitrogen per 600g soil in a pat increased the growth of Brassica rapa var. perui-ridis.

• Journal of Korean Society of Environmental Engineers
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• v.30 no.6
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• pp.666-672
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• 2008

Feasibility of simultaneous removal of organic matter, nitrogen and phosphorus was evaluated by applying AO$_2$ system to treat wastewater from a seafood processing plant. Treatability test was conducted by incorporating activated sludge from municipal sewage treatment plant with PU-AC media. Inflow concentrations of COD, TN, and TP were 198$\sim$1,240 mg/L, 75$\sim$577.4 mg/L, and 2.2$\sim$53.5 mg/L, respectively. Average removal efficiencies and outflow concentration of COD, TN, and TP were 86.5%, 65.7 mg/L; 81.4%, 53.1 mg/L; and 80.6% 4.07 mg/L, respectively. Stable operation was possible by increasing organic matter, nitrogen, and phosphorus loading rate to seafood wastewater treatment system composed of anaerobic and aerobic reactors. Used PU-AC media was proved to be biodegradable in this AO$_2$ system by maintaining high biomass concentration in the PU-AC media.

• Journal of Korean Society on Water Environment
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• v.22 no.2
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• pp.215-221
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• 2006

This research presents results from laboratory and pilot-scale experiments to remove high-nitrate in pickling wastewater using the sequencing batch reactor (SBR) as a biological method. During the experimental periods, the influent concentrations of NOx-N and $Ca^{+2}$ were analyzed to be 350-1,600 and 700-800 mg/L, respectively. In order to provide carbon source for denitrification, methanol has been added in proportion to the influent nitrate loading. The mean concentrations of MLSS and MLVSS, the fraction of volatile solids in sludge and the sludge volume index were measured to be 27 g/L, 5 g/L, 18.5% and 7.5, respectively. The solid retention time was kept in the range of 18 to 22 days, specific denitrification rate ($U_{dn}$) was $0.301g{NO_3}^--N/gVSS/day$. The oxidized nitrogen concentration of effluent ranged 2-34 mg/L with an average of 5.2 mg/L, the overall reduction in total nitrogen was more than 99.2%. In order to treat the pickling wastewater including the high concentration of nitrate and $Ca^{+2}$, the continuous flow process is not suitable because the specific gravity of the sludge is considerably increased by $Ca^{+2}$, thus the SBR process is shown to be very effective to treat the pickling wastewater.

• Journal of Aquaculture
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• v.13 no.2
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• pp.137-145
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• 2000

Capacity of water treatment of the three phase fluidized bed reactor as a biofilter in the seawater recirculating system was evaluated. The water treatment system consists of fluidized bed reactor for ammonia removal, cartridge filter for solid removal and ozone contactor for disinfection. Mean concentration of water quality parameters: COD, TAN, $NO_2$-N, $NO_3$-N, SS and alkalinity were 9.0, 0.22, 0.05, 20.0, 9.5 and 70.0 mg/l, respectively; the relevant values were 7.6 for pH and 3.64 NTU for turbidity. These indicate the maintenance of good water quality by the treatment system. The influent TAN loading rate in to the fluidized bed reactor ranged from 4.3 to 32.9 g/$m^3$/day, and averaged to 20 g/$m^3$/day. TAN removal efficiency of each phase of the fluidized bed reactor was 47-60%, indicating the effective ammonia removal. During operation the effluent of fluidized bed reactors also maintained the unionized ammonia nitrogen level below 0.002 mg/l.

• Journal of Korean Society of Water and Wastewater
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• v.27 no.6
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• pp.761-770
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• 2013

This study was carried out to forecast the flow rate and water quality at the inlet of the Saemangeum bay in Korea using the SWMM(Storm Water Management Model) and the WASP(Water Analysis Simulation Program), and to analyze the impacts of pollutant loading from non-point source on the water quality of the bay. The calibration and validation of flow rate and water quality were performed using those from two monitoring points in the Mankyeong river administrated by Korean Ministry of Environment as part of the national water quality monitoring network. When the river flow rate was calibrated and validated using the rainfall intensities during 2011-2012, $R^2$ (i.e., coefficient of determination) was ranged from 0.91 to 0.96. For water qualities, it was shown that $R^2$ of BOD(Biochemical Oxygen Demand) was ranged from 0.56 to 0.86, and $R^2$ of T-N(Total Nitrogen) was from 0.64 to 0.75, and $R^2$ of T-P(Total Phosphorus) was from 0.67 to 0.89. The integrated modeling system showed significant advances in the accuracy to estimate the water quality. Finally, further simulations showed that annual average flow of the river running into the bay was estimated to be $1.439{\times}10^9m^3/year$. The discharged load of BOD, T-N, and T-P into the bay were anticipated to be 618.7 ton/year, 331.5 ton/year, and 40.4 ton/year, respectively.

• Journal of Embryo Transfer
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• v.14 no.3
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• pp.145-153
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• 1999

This study was conducted to investigate the effects of vitrification solution and developmental stage on the survival rate of vitrified-thawed human blastocyst embryos. Human blastocyst embryos were cryopreserved by vitrification using EFS and GE solution, and their survival rates were examined after thawing and further culture. EFS solution was consisted of 40% ethylene glycol, 18% Ficoll 70 and 0.3M sucrose. GE solution was consisted of 25% glycerol and 25% ethylene glycol. Embryos were exposed to EFS and GE solution by 2 steps and 3 steps, respectively, and plunged into liquid nitrogen after loading into 0.25ml plastic straws. Blastocysts were classified into 4 groups in accordance with their developmental stage: into 1) EEB, 2) MEB and 3) EdB, of blastocysts developed on day 5, and 4) 6d-Bla(the blastocysts which formed on day 6). The blastocysts at each stage were vitrified by GE solution and cryopreserved in LN2. After thawing them, we examined their survival rates, respectively. The resulted of this study were as follows: 1. The survival rate of blastocysts vitrified by GE solution was 64.4%, significantly higher than that (5.7%) vitrified by EFS solution (P<0.001). 2. When the blastocysts were vitrified by GE solution according to each developmental stage, the survival rates of EEB, MEB, EdB and 6d-Bla were 65.9%, 65.9%, 73.2% and 58.1%, respectively. In conclusion, the cryopreservation of human blastocysts by vitrification is likely to have a marked advantage in terms of cost, work and time as compared to the conventional slow freezing in IVF-ET programs.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2021.04a
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• pp.36-36
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• 2021

Cryopreservation has been broadly used as an efficient method for a long-term conservation for many types of plants especially vegetatively propagated plants. Among several cryopreservation methods, a droplet-vitrification was the most widely applicable and efficient method. Studies have developed protocols for strawberry using droplet-vitrification method and suggested the practical use of the protocol for large number of germplasm with a little modification. In this study, the droplet vitrification method of shoot tip has been tested on 31 accessions provided around the world. Shoot tips were precultured on Murashige and Skoog (MS) liquid medium supplemented with 0.3~0.5M sucrose. Precultured explants were osmoprotected with loading solution, 35% of PVS3 (C4, 17.5% glycerol and 17.5% sucrose) for 40 min and exposed to dehydration solution, PVS3 (B1, 50% glycerol and 50% sucrose) for 60 min. Then, the explants were transferred onto droplets containing 2.5 uL PVS3 on sterilized aluminum foils prior to direct immersion in liquid nitrogen (LN) for 1hr. The cryopreserved shoot tips were rapidly warmed in a water bath at 40C and then unloaded in MS with 0.8M sucrose for 40 min. The shoot tips were cultured in NH₄NO₃-free MS post culture medium for 2 weeks. Subsequently, the explants were moved to the MS medium for 6 weeks and evaluated the regrowth rate. By this droplet-vitrification protocol, twenty-four accessions showed at least 40% regrowth rate. Out of 24 accessions, 'Nonsan1ho' had the highest regeneration rate of 85.8% and 'Jumbo pureberry' had the lowest with 42.1%.