• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.10 no.3
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• pp.145-153
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• 2005

I reviewed an ecological and environmental significance of microbial carbon respiration coupled to dis-similatory reduction of fe(III) to Fe(II) which is one of the major processes controlling mineralization of organic matter and behavior of metals and nutrients in various anaerobic environments. Relative significance of Fe(III) reduction in the mineralization of organic matter in diverse marine environments appeared to be extremely variable, ranging from negligible up to $100\%$. Cenerally, Fe(III) reduction dominated anaerobic car-bon mineralization when concentrations of reactive Fe(III) were higher, indicating that availability of reactive Fe(III) was a major factor determining the relative significance of Fe(III) reduction in anaerobic carbon mineralization. In anaerobic coastal sediments where $O_2$ supply is limited, tidal flushing, bioturbation and vegetation were most likely responsible for regulating the availability of Fe(III) for Fe(III) reducing bacteria (FeRB). Capabilities of FeRB in mineralization of organic matter and conversion of metals implied that FeRB may function as a useful eco-technological tool for the bioremediation of anoxic coastal environments contaminated by toxic organic and metal pollutants.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.8 no.2
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• pp.210-224
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• 2003

Sulfate reduction is a microbiological process which occurs ubiquitously in anaerobic marine environment. Sulfate reducing bacteria play a significant role in anaerobic decomposition of organic matter and regeneration of inorganic nutrients which supports the primary production in the water column (i.e., benthic-pelagic coupling) and, in special case, could be responsible for the harmful algal bloom in the coastal marine environment. Summary of the sulfate reduction rates reported in various marine sedimentary environments revealed that supply of organic substrates and presence of various electron acceptors (i.e., $O_2$, NO$_{3}$$^{[-10]}$ , Fe(III) and Mn(IV), etc.) for other aerobic and anaerobic respiration directly affect the sulfate reduction rate and relative significance of sulfate reduction in organic matter mineralization. Significance of temperature, macrophytes and bioturbation is discussed as factors controlling supply of organic substrates and distribution of electron acceptors. Finally, we suggest studies on the anaerobic microbiological processes associated with biogeochemical element cycles in the coastal environments of Korea where massive operation of organic enriched fish cage farm, frequent occurrence of toxic algal bloom and hypoxia and conservation of tidal flat are of major environmental issues.

• Journal of Animal Environmental Science
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• v.7 no.1
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• pp.39-44
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• 2001

This research was carried out to determine the quantity and characteristics of layer excreta produced in different age and different types of layer house. Daily feed intakes in the growing stage were 60.8 and 92.9g/d the 6th and 12th week of age, respectively. Daily feed intakes in the early laying stage (19th wk of age) and the ending period of laying(55th wk of age) were 105.1 and 122.0 g/d, respectively. A laying hen consumed 193.1~222.5$m\ell$ of water per day. The amount of excreta produced by laying hen were 143.3~144.8g per day. The moisture contents of excreta produced by laying hen ranged over 74.7~80.5% in laying period. The average contents of N, $P_2O_5$ and $K_2O$ in layer excreta were 4.88, 1.92 and 1.71% in DM basis, respectively. In the laying period, CaO contents of excreta were 7.42~9.02%. The moisture contents of excreta produced by windowless poultry house, open-sided poultry house applied mechanical ventilation and open-sided poultry house applied natural ventilation were 65.4, 75.7 and 81.3% in summer, respectively.

• Journal of Animal Environmental Science
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• v.12 no.3
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• pp.161-168
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• 2006

This paper describes the changes of characteristics of pig slurry according to storing depth. Most of the substances containing pollutants, such as were Management of manure and wastewater from animal confinement facilities is a critical factor for pollution control. With proper treatment processing method in both solid and liquid forms, it can be used as a fertilizer and soil conditioner. In Korea, liquid-manure handling system is very popular because its treatment and application is easy and labor saving. In the storage tank treatment, the period of fermentation process and solids-liquid separation averages six months and the supernatant liquid is being used as a fertilizer. In this study, the changes in chemical characteristics of pig slurry at varying depths of the storage tank were investigated. Results showed that the pH value of the fermented pig slurry was > 7, while the major pollutants such as BOD, SS, N and P were highest in the bottom of the tank. Therefore, the above findings proved that varying depths in the storage tank can influence the concentration of pollutants of the fermented pig slurry.

• Journal of Food Hygiene and Safety
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• v.17 no.3
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• pp.129-136
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• 2002

This study was conducted to Provide basic information Promoting egg qualify improvement and hygienic control by grasping of present market egg distribution system and hygienic quality. The eggs of 57 brands collected from the department food stores in Incheon Metropolitan City were examined. Eggs were kept in room temperature in all the market and 70.2% of the brands were marked the expiration date indicating that eggs would be available over 28 days after being laid. Fifty-four % of the market eggs was classified as a special or functional egg. Expiration date and date of laying were common labelling items in all brands. These items were labelled in trade mark sheet or eggs tray. Only 66.6% of the brands had the mark about net quantity of contents. The inspection about the exterior and contents of eggs has results as follows: eggshell contamination of feces and feather-9.5%, abnormal and broken eggshell -3.9%, blood and meat spots in contents -14.7% and watery whites -1.8%. Average of Haugh Unit(HU) was 56.1 and below HU 31 were 18 of 285 eggs(6.3%), in addition, more than one egg detected in 12 brands(21.1%) among 57 brands have inferior quality. Salmonella enteritidis from eggshell and antibodies directed from S. enteritidis in the yolks of eggs available in the market were not detected. Ranges of Total bacterial count (CFU/ml) on eggshell of eggs were < 10~8.2$\times$10$_3$, and isolation ratio of Escherichia coli were 4.7%. Tetracyclines were detected in 1.8% of the eggs(1 of57 brands) by CHARMII. As mentioned above, quality control and improving distribution system were required to facilitate egg consumption and improve public health by complementing labelling items and quality standards.

• Korean Journal of Food Science and Technology
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• v.34 no.3
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• pp.536-539
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• 2002

This study was investigated for the preparation method of meju by three step fermentation. The steamed soybeans were fermented with nisin-producing Lactococcus lactis subsp. lactis IFO12007 to inhibit the growth of odor-producing Bacilli and promote of normal fermentation of meju. The lactie-fermented soybeans were further fermented with Aspergillus oryzae and Bacillus subtilis. The produced meju by this method showed 54%moisture content and pH 7.0, respectively. The three step fermented meju was soaked in 20% (w/v) brine at $25^{\circ}C$ for 90days. After 30 days, the contents of total free amino acids revealed 4,015 mg% which were higher $3{\sim}5$ times than controls. Among the detected free amino acids, the contents of glutamic acid and leucine showed 925 mg% and 380mg%, respectively. Therefore, the new method of producing meju would be an excellent alternative to improve the quality of soybean fermented food, such as doenjang and kanjang.

• Current Research on Agriculture and Life Sciences
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• v.16
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• pp.75-83
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• 1998

The purpose of this survey was to investigate the regional and seasonal characteristics of a water system and to obtain basic information of a water system at Andong bridge, Nakdan bridge, Kangjung, Waekwan bridge and Koryung bridge along Nakdong River. We surveyed the water quality in the Nakdong River for 2 years from Jan. 1996 to Dec. 1997. The results summarized were follows; 1) The pH in the Nakdong River on the basic of 2 years average were 6.5-8.6. 2) The DO, the COD and the BOD were low level in summer and high level in winter, respectively. 3) The suspended solids(SS) contents was high especially in summer. 4) The T-P and the T-N contents were higher than the lower level of nitrogen and phosphorous for algae growth and the contents were high especially in winter. 5) The $NH_4{^+}$-N and $NO_3{^-}$-N were also observed to be quite high.

• Journal of the Korean Applied Science and Technology
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• v.34 no.4
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• pp.908-914
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• 2017

In this study, we developed a system that automatically removes the scale in the piping by using electrolysis principle in order to solve the cooling performance of the refrigeration and air conditioning system by acting as heat resistance in the heat transfer process by forming the scale in the heat exchanger for refrigeration air conditioning. We want to check the performance through experiments. Therefore, by circulating the treated water using the principle of electrolysis without stopping the system, Ca, Mg and $SiO_2$ are precipitated in the form of solids and discharged to the outside of the pipe system, thereby preventing scale formation in the pipe and removing the scale. Thereby maintaining the heat transfer performance of the pipe. As a result of the experiment, the heat transfer rate of the scaled pipe was 86.66% when the heat transfer rate of the new pipe was 100, and the heat transfer rate was recovered to 90.5% when the scaled pipe was operated for 1 month. The heat transfer rate recovered to 97.86% when driving for two months and to 98.72% for three months. It was confirmed that the scaling effect of the scale formed in the piping was understood in a relatively short experiment period, and the heat transfer performance was also influenced.

• Journal of the Korean Applied Science and Technology
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• v.34 no.4
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• pp.866-873
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• 2017

Exhaust regulations of automobile are being reinforced increasingly as environmental problems issues came to the fore by industrial development. However, it is known that the exhaust emission is not only influenced by the system of automobile but also the fuel properties. In particular, high-performance engines have required high-performance fuels with high lubricity as CRDI engines(diesel engine) have been developed and commercialized. This paper have examined that the fuel property variations affect a major parts and an exhaust gas of automobile. It was confirmed that the high pressure pump, the injector and the DPF(diesel particulate filter) were damaged and fuel efficiency was get worse due to use the fuel of lacking lubricity property($651{\mu}m$/quality standard: less in $400{\mu}m$). In addition, through an iron component was detected in the broken DPF, it was estimated that the breakage of the DPF was caused by the excessive exhaust of the particulate matter due to the iron component of the fuel.

• Journal of agriculture & life science
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• v.45 no.4
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• pp.59-63
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• 2011

The symptoms such as weaken shape, partial and full death in nurse- and old- trees have been mostly caused by the occurrence of cavity. In general, the adaption of poly-urethane has been practised routinely in the way of treatment in cavity. However, the use of poly-urethane was not an effective, but it was related to pollution materials. Here, the experiment was conducted to identify the effects of the treatments of loess or micro-organisms for the alternatives of poly-urethane. The cavities which occurred in Zelkova serrata, Prunus yedoensis and Quercus myrsinaefolia were treated by poly-urethane, loess, mixtured loess and micro-organism (Rhadobacter), and mixtured loess and micro-organism (Rhodobacter + bacillus). As the results of this experiment, it was shown that the treatment of mixtured loess and micro-organism (Rhodobacter + bacillus) induced to develop greater callus formation in the cavity up to 97% in Zelkova serrata, up to 87% in Prunus yedoensis, and by 73% in Quercus myrsinaefolia than the treatment of poly-urethane. But the only loess and mixtured loess and micro-organism (Rhadobacter) was a similar or lower callus formation ratio than poly-urethane.