• 한국수산과학회지
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• 제47권6호
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• pp.1026-1036
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• 2014

Real-time monitoring for environmental factors (temperature, salinity, chlorophyll-a, etc.) and fugacity of carbon dioxide ($fCO_2$) was conducted at an oyster Crassostrea gigas farm in Goseong Bay, south coast of Korea during 2-4th of November, 2011. Surface temperature and salinity were ranged from $17.9-18.7^{\circ}C$ and 32.7-33.8, respectively, with daily and inter-daily variations due to tidal currents. Surface $fCO_2$ showed a range of $390-510{\mu}atm$ and was higher than air $CO_2$ during the study period. Surface temperature, salinity and $fCO_2$ are showed significant correlations with chl.-a and nutrients, respectively. It means when chl.-a value is high in surface water of the oyster farm, active biological production consume $CO_2$ and nutrients from environments and produce oxygen, suggesting a tight feedback between biological processes and environmental reaction. Thus, factors affecting the surface $fCO_2$ were evaluated using a simple mass balance. Temperature and biological productions by phytoplankton are the main factors for $CO_2$ drawdown from afternoon to early night, while biological respiration increases seawater $CO_2$ at night. Air-sea exchange fraction acts as a $CO_2$ decreasing gear during the study period and is much effective when the wind speed is higher than $2-3m\;s^{-1}$. Future studies about organic carbon and biological production/respiration are required for evaluating the roles of oyster farms on carbon sink and coastal carbon cycle.

• 한국축산식품학회지
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• 제37권4호
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• pp.571-578
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• 2017

This study aimed to determine the optimal ratio of natural calcium powders (oyster shell and egg shell calcium) as synthetic phosphate replacers in pork products. Ground pork samples were subjected to six treatments, as follows: control (-) (no phosphate added), control (+) (0.3% phosphate blend added), treatment 1 (0.5% oyster shell calcium powder added), treatment 2 (0.3% oyster shell calcium powder and 0.2% egg shell calcium powder added), treatment 3 (0.2% oyster shell calcium powder and 0.3% egg shell calcium powder added), and treatment 4 (0.5% egg shell calcium powder added). The addition of natural calcium powders resulted in an increase in the pH values of meat products, regardless of whether they were used individually or mixed. The highest cooking loss was observed (p<0.05) in the negative control samples, whereas the cooking loss in samples with natural calcium powder added was similar (p>0.05) to that in the positive control samples. CIE $L^*$ values decreased as the amount of added egg shell calcium powder increased. CIE $a^*$ values were higher (p<0.05) in samples containing natural calcium powder (treatments 1, 2, 3, and 4) than in the positive control. The combination of oyster shell calcium powder and egg shell powder (treatment 2 or 3) was effective for the improvement of textural properties of the pork products. The findings show that the combined use of 0.2% oyster shell calcium and 0.3% egg shell calcium should enable the replacement of synthetic phosphate in the production of cooked pork products with desirable qualities.

• Korean Chemical Engineering Research
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• 제59권1호
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• pp.118-126
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• 2021

폐기물로 대량 발생되는 굴껍질을 활용한 vaterite 형 탄산칼슘 제조 실험을 하였다. 굴껍질을 800 ℃의 온도에서 항량이 되도록 가열하여 산화칼슘이 주성분인 소성 굴껍질을 제조하였다. 이 굴껍질을 질산 용액에 녹여 0.1 M 질산칼슘 수용액을 만들고, 0.1 몰 라이신/1 몰 생석회가 첨가된 0.1 M 탄산나트륨 수용액과 20 ℃, 600 rpm 교반 조건에서 1시간동안 반응시켜 탄산칼슘을 제조하였다. XRD, SEM, Size 분석을 하고 vaterite 84.5%, calcite 15.5% 함유한 구형 탄산칼슘을 확인하였다. 평균 입경 범위는 6.87 ㎛ 이었고, 아미노산 분석에서 탄산칼슘 내의 라이신 함유량은 0.1%이었다.

• 한국환경농학회지
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• 제28권4호
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• pp.378-385
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• 2009

Arsenic (As) is known to be very toxic and carcinogenic to human beings. Arsenic contaminated soil was collected from a timber mill site at Busan Metropolitan City, Korea, where chromated copper arsenate (CCA) had been used to protect wood from rotting caused by insects and microbial agents. The soil was stabilized using both natural oyster shells (NOS) and calcinated oyster shells (POS). The calcination of natural oyster shells was accomplished at a high temperature in order to activate quicklime from calcite. Two different oyster shell particle sizes (-#10 mesh and -#20 mesh) and curing periods of up to 28 days were investigated. The stabilization effectiveness was evaluated based on the Korean Standard Test (KST) method (1N HCl extraction). The stabilization results showed that the POS treatment was more effective than the NOS treatment at immobilizing the As in the contaminated soils. A significant As reduction (96%) was attained upon a POS treatment at 20 wt% and passed the Korean warning standard of 20 mg/kg ('Na' area). However, an As reduction of only 47% (169 mg/kg) was achieved upon a NOS treatment at 20 wt%. The -#20 mesh oyster shells seem to perform better than the -#10 materials. The scanning electron microscopy (SEM)-energy dispersive X-ray spectroscopy (EDX) results showed that As immobilization was strongly associated with Ca and O in the presence of Al and Si.

• 한국식품영양과학회지
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• 제44권11호
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• pp.1645-1652
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• 2015

해양생물 유래 피부건강 기능성의 소재를 발굴할 목적으로 굴 단백질을 Protamex와 Neutrase로 가수분해 한 후 생성된 굴 가수분해물 펩타이드의 주름 개선 효과를 조사하였다. 굴 가수분해물은 약 7.9%의 유리아미노산을 포함하며 urea, taurine, alanine, glycine 등의 아미노산의 함량이 높았다. 굴 가수분해물은 collagenase 저해 활성을 가지고 있었고, 피부세포인 CCD986sk에 대한 독성은 없었다. 분획물의 수율은 1,000 Da 미만이 40%였으며, 5,000 Da 미만이 60.4%를 차지하였다. 1,000~3,000 Da인 분획물이 항산화 활성, procollagen의 생성능 및 MMP-1 효소 저해 활성이 가장 높았다. 굴 가수분해물과 5,000 Da 미만의 분획물은 주름 개선을 위한 피부건강 기능성 소재로서 화장품 등의 제품에 응용 가능함을 확인하였다.

• 한국축산식품학회지
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• 제44권4호
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• pp.849-860
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• 2024

The use of natural ingredients in meat processing has recently gained considerable interest, as consumers are increasingly attracted to clean-label meat products. However, limited research has been conducted on the use of natural substitutes for synthetic phosphates in the production of clean-label meat products. Therefore, this study aimed to explore the potential of oyster shell powder as a substitute for synthetic phosphates in pork patties cured with Chinese cabbage or radish powders. Four different groups of patties were prepared using a combination of 0.3% or 0.6% oyster shell powder and 0.4% Chinese cabbage or radish powder, respectively. These were compared with a positive control group that contained added nitrite, phosphate, and ascorbate and a negative control group without these synthetic ingredients. The results showed that patties treated with oyster shell powder had lower (p<0.05) cooking loss, thickness and diameter shrinkage, and lipid oxidation than the negative control but had lower (p<0.05) residual nitrite content and curing efficiency than the positive control. However, the use of 0.6% oyster shell powder adversely affected the curing process, resulting in a decreased curing efficiency. The impact of the vegetable powder types tested in this study on the quality attributes of the cured pork patties was negligible. Consequently, this study suggests that 0.3% oyster shell powder could serve as a suitable replacement for synthetic phosphate in pork patties cured with Chinese cabbage or radish powders. Further research on the microbiological safety and sensory evaluation of clean-label patties during storage is required for practical applications.

• Journal of Biosystems Engineering
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• 제34권4호
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• pp.211-219
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• 2009

In the process of oyster mushroom production, loading work of culture medium needs the most intensive labor power and cost. Therefore, the development of culture medium loading machine causes to reduce the manpower and cost. The main objectives of this study are identify cultivating environment, physical properties of culture medium and to make an element design of culture medium loading machine. The results are summarized as follows: 1. The moisture content and density of popularly used culture medium were 70%(w.b), $26\;kg/m^3$, respectively. 2. Pressure of the blower increased as the impeller speed increased, and the opening ratio of pressure controller decreased. 3. Recommendable c1earance(${\delta}$) between an impeller plate and a blower case was 25 mm at an impeller speed of 3183 rpm 4. Discharge device of type B with a hopper and suit was better than type A with a hopper.

• Journal of Biosystems Engineering
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• 제34권4호
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• pp.220-227
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• 2009

In the process of oyster mushroom production, loading work of culture medium needs the most intensive labor power. Therefore, development of culture medium machine causes to reduce the manpower and cost. The main objective of this study is to develop the culture medium loading machine and investigate the optimal operation conditions and to evaluate the economic value of the machine. The results are summarized as follows: 1. Optimum transporting velocity of the conveyor was 0.61 m/s 2. Optimum speed of blower was 3183 rpm at the transporting velocity of 0.61 m/s with the loading quantity of 3.41 t/hr 3. Recommendable opening area ratio of pressure controller was 1/2 at the blower speed of 3183 rpm and the transporting velocity of 0.61 m/s 4. The break even point resulted in $240\;m^2$ of cultivating area compared to the method of with portable workbench, and $350\;m^2$ of cultivating area compared to the method of with a tractor and a truck.

• 환경생물
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• 제20권4호
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• pp.378-385
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• 2002

가막만 양식 참굴의 정장양상을 모델화 하기 위해 1997년 3월부터 1998년 5월가지 양식장에서 무작위 채집된 총 9,208개체의 각장 및 습중량을 조사하였으며, 참굴 양식장의 환경용량을 추정하기 위하여 1985년부터 2000년까지의 단위면적 당 생산량과 시설대수를 조사하였다. 참굴의 성장모델 추정에는 Bertalanlffy 성장식, 계절변동을 고려한 Bertalanffy 성장식과 일반화된 Schnute and Richards 성장식이 사용되었고, 환경용량의 추정을 위해서는 Schaefer와 Fox의 잉여 생산량 모델들이 사용되었다. 추정된 길이 성장모델은 Bertalanffy모델을 적용하였을 때 보다 일반화된 Schnute and Richards 성장식을 적용했을 때 적합도가 높았다. 추정된 환경용량은 Schaefer모델에서 $21.1\;7ton\;ha^{-1}$, Fox모델에서는 1$17.7\;ton\;ha^{-1}$, 로 2000년 현재의 단위면적 당 생산량 $26.1\;ton\;ha^{-1}$, 보다 낮았으나 환경용량을 생산하는 시설 대수는 8대$(ha^{-1})$로 2000년 현재의 7.8대$(ha^{-1})$와 유사한 값을 보였다.

• 농업과학연구
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• 제49권4호
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• pp.949-961
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• 2022

The purpose of this study is to build an oyster outlook model. In particular, by limiting oyster items, it was designed as a partial equilibrium model based on a panel analysis of a fixed effect model on aquaculture facilities. The model was built with a dynamic ecological equation (DEEM) system that considers aquaculture and harvesting processes. As a result of the estimation of the initial aquaculture facilities based on the panel analysis, the elasticity of the remaining facility volume in the previous month was estimated to be 0.63. According to Nerlove's model, the adjustment coefficient was interpreted as 0.31 and the adjustment speed was analyzed to be very slow. Also, the relative income coefficient was estimated to be 2.41. In terms of elasticity, it was estimated as 0.08% in Gyeongnam, 0.32% in Jeonnam, and 1.98% in other regions. It was analyzed that the elasticity of relative income was accordingly higher in non-main production area. In case of the estimation of the monthly harvest facility volume, the elasticity of the remaining facility volume in the previous month was estimated as 0.53, and the elasticity of the farm-gate price was estimated as 0.23. Both fresh and chilled and frozen oysters' exports were estimated to be sensitive to fluctuations in domestic prices and exchange rates, while Japanese wholesale prices were estimated to be relatively low in sensitivity, especially to the exchange rate with Japan. In estimating the farm-gate price, the price elasticity coefficient of monthly production was estimated to be inelastic at 0.25.