• 한국균학회지
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• 제30권1호
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• pp.18-22
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• 2002

느타리버섯 봉지 재배의 봉지직경 및 배지량에 따른 생육특성을 비교하여 효율적인 봉지규격을 추정하고자 미송톱밥, 비트펄프, 면실박을 부피비로 50 : 30 : 20으로 혼합한 배지로 봉지 직경 $10{\sim}20\;cm$, 배지량 $600{\sim}2,500\;g$/봉지 범위에서 시험 한 결과 봉지직경이 작을수록 배지량이 많아짐에 따라 배지길이가 길어져 배양일수가 지연되었고 이에 따라 총재배기간이 길었다. 또한 2주기까지의 수량은 같은 봉지직경에서 배지량이 클수록 증가하였고 배지량이 1,200 g/봉지보다 많으면 생물학적효율은 감소하여 100% 보다 낮았으며, 같은 배지량에서 봉지 직경에 따른 수량은 큰 차이 없으나 회수율은 봉지직경이 14 cm 보다 크면 감소하였다. 따라서 재배기간, 수량, 생물학적효율 등을 고려한 효율적인 봉지직경은 $10{\sim}14\;cm$, 배지량 $800{\sim}1,200\;g$/봉지 내외로 추정되었다.

• 생물환경조절학회지
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• 제30권1호
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• pp.27-36
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• 2021

정전용량 수분측정 센서는 수경용 배지 양쪽에 구리 및 테플론으로 절연된 전극판(30cm×10cm)을 부착하여 배지의 넓은 부분에 걸쳐 측정하도록 개발되었다. 본 연구는 콘덴서형 정전용량 센서로부터 출력되는 정전용량 값을 배지 함수량으로 변환하는 것이다. 정량화 실험은 양액을 공급하면서 배지 물무게와 정전용량 변화를 측정하고 그 값을 비교하는 방식으로 수행되었다. 배지 함수량과 정전용량은 본 연구를 위해 특별히 개발된 소프트웨어와 함께 센서와 로드셀을 사용하여 20~30초마다 측정되었다. 상용 curve-fitting 프로그램을 이용하여 배지 함수량과 정전용량을 변수로 정전용량 값으로 배지 함수량을 추정하였다. 공급하는 물의 양이 증가하면 정전용량도 증가하는 경향을 보였다. 배지 내 물무게에 따른 정전용량에 대한 변동계수(coefficient of variation, cv)는 배지 내 물무게가 1.0kg 수준에서 다른 무게에 비해 높아 함수량 보정은 물무게를 1.7~6.0kg 수준에서 수행하였다. 정전용량과 물무게 사이의 상관 계수는 0.996이었고 보정식에 의해 정전용량으로 추정된 함수량은 로드셀로 측정한 배지 함수량과 비교하였다.

• Mycobiology
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• 제36권3호
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• pp.157-160
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• 2008

This study was carried out to determine the possibility of bottle cultivation utilizing recycled oyster mushroom culture waste as a cultivating substrate for P. ostreatus. Total nitrogen percentage was 0.76%, 1.13%, 1.16%, 1.36%, and 1.38% in the 1-, 2-, 3-, 4-, and 5-time mixed substrate, respectively; 0.95%, 1.04%, 1.34%, 1.36%, and 1.25% in the 1-, 2-, 3-, 4-, and 5-time postharvest substrate, respectively; and 0.72% and 0.68% in the 2- and 3-time nonadditive substrate, respectively. Weight of the fresh fruiting body harvest was 115 g, 120 g, 117 g, 118 g, and 114 g on 1-, 2-, 3-, 4-, and 5-time mixed substrate, respectively; and 105 g and 45 g on 2- and 3-time nonadditive substrate, respectively. The first mixed substrate (fresh) and recycled substrates generated no significant difference in the weight of fresh fruiting bodies harvested.

• 수산해양교육연구
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• 제11권2호
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• pp.139-149
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• 1999

Thermal sprayed Ni-Cr alloy coating on the carbon steel was carried out erosion-corrosion test and electrochemical corrosion test in the marine environment. The erosion-corrosion behavior and electrochemical corrosion characteristics of substrate(SS400) and thermal sprayed Ni-Cr coating was investigated. The erosion-corrosion control efficiency of Ni-Cr coating to substrate was also estimated quantitatively. The main results obtained are as follows : 1) The weight loss rate of Ni-Cr coating layer by the erosion-corrosion compared with substrate was smaller. With the lapse of time, the weight loss rate of substrate was linearly increased in $25{\Omega}{\cdot}cm$ solution, but that of Ni-Cr coating became stable. 2) The corrosion potential of substrate became less noble than that of Ni-Cr coating layer, and the corrosion current density of Ni-Cr coating became lower than that of substrate. 3) The control efficiency of erosion-corrosion of Ni-Cr coating compared to substrate became more dull than that of corrosion in $25{\Omega}{\cdot}cm$ and $5000{\Omega}{\cdot}cm$ solution.

• 한국세라믹학회지
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• 제36권9호
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• pp.991-996
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• 1999

Effect of solution property on the weight varation and microstructural change of film was studied by electrophoretic deposition in order to obtain a homogeneous and dense zirconia film. As a result of weight kinetics of film which obtained in alcohol or aqueous solution having different polarity experimental data showed large deviation from theoretical ones calculated by Zhang's kinetic model. It had been shown that the weight affecting factors was largely dependent on properties other than dielectric constant and viscosity of solvent zeta potential appiled field and time. In initial stage a main factor of the drastic weight increase was the capillary drag of porous substrate. The cause of weight decrease with time in aqueous solution after 300 s was attributed to the defect of film by sagging and electrolytic reaction. The electrolyte film which prepared in alcohol solution with good wetting for substrate had better homogeneous and dense microstructure than one in aqueous solution with high surface tension.

• 한국환경과학회지
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• 제24권9호
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• pp.1221-1231
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• 2015

The present study was conducted to find a way to recycle the coir substrate by investigating changes in its physical and chemical properties based on the number of use year. Specific gravity of unused coir substrate was $0.212g/cm^3$, while it was higher for the substrate used for 2 years. Porosity was different depending on the number of use year. The porosity of unused substrate was 51.9%, but it increased to 68.6% after used for 2 years. In general, physical and chemical properties were better in the coir substrate used for 2 years than in unused one. The number of leaves, leaf area, flesh weight and dry weight of oriental cabbage and lettuce were higher in coir substrate used for 2 years than those in unused one. Whereas, no significant difference was observed between the substrates used for one year and 2 years, indicating that the one time-used wast substrate could be recycled for cultivating vegetables. Growth of the vegetables was improved when organic fertilizer composed of complex organics with different mixing ratios was provided to the coir substrate, compared to untreated plot. The optimum mixing ratio of the wast substrate and complex organics was 2:8(v/v) for fertilization using wast coir substrate. Therefore, coir substrate generally wasted after being used for one time was reuseable by supplying organic fertilizer.

• 멤브레인
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• 제12권1호
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• pp.21-27
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• 2002

본 연구에서는 회분여과방식을 이용하여 부하율에 따라 생성되는 생물대사성분의 특성 및 분포를 관찰하였다. 실험에 사용된 기질은 단일 탄소인 phenol을 사용하였으며, 분자량 분포실험을 위하여 분자량이 각각 30K, 100K Dalton 및 $0.45{\mu}$ membrane filter를 이용하여 구하였다. 페놀농도가 120, 230 및 440 mg/L 일 때 비기질이용율(q)은 각각 0.639, 1.281, 1.744 (mgTOC/mg MLSS/day)로 나타났으며 Run C일 때 가장 높은 이용율을 나타냈다 . 내생단계에서 미생물의 사멸율($K_d$)는 각각 0.0536, 0.0661, 0.0749($day^1$)이며 생성계수 ($SMP_e$) 는 각각 0.006, 0.0058, 0.0057($day^1$)로 나타났다. 초기 유입된 기질이 기질분해에 의해 생성된 $SMP_s$로 분해되어지며, 시간경과에 따라 $SMP_{nd}$ 로 진행됨을 알수 있었다. 기질분해 완료 후 미생물의 내생단계에 접어들면서 $SMP_e$성분으로 전환되었다. 유입부하율에 따른 분자량 분포 측정결과는 운전시간이 경고함에 따라 점차 저분자 물질이 고분자의 난분해성 물질로 전환되었다.

• Corrosion Science and Technology
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• 제23권3호
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• pp.228-234
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• 2024

Zinc wiping is a phenomenon used to control zinc-coating thickness on steel substrate during hot dip galvanizing by equipment called air knife. Uniformity of zinc coating weight in length and width profile along with surface quality are most critical quality parameters of galvanized steel. Deviation from tolerance level of coating thickness causes issues like overcoating (excess consumption of costly zinc) or undercoating leading to rejections due to non-compliance of customer requirement. Main contributor of deviation from target coating weight is dynamic change in air knives equipment setup when thickness, width, and type of substrate changes. Additionally, cold coating measurement gauge measure coating weight after solidification but are installed down the line from air knife resulting in delayed feedback. This study presents a coating weight control model (Galvantage) predicting critical air knife parameters air pressure, knife distance from strip and line speed for coating control. A reverse engineering approach is adopted to design a predictive, prescriptive, and descriptive model recommending air knife setups that estimate air knife distance and expected coating weight in real time. Implementation of this model eliminates feedback lag experienced due to location of coating gauge and achieving setup without trial-error by operator.

• Journal of Ecology and Environment
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• 제44권1호
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• pp.45-53
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• 2020

Background: The black soldier fly (Hermetia illucens) is gaining attention as an efficient decomposer of food waste. However, recalcitrant compounds such as plastics mixed into food waste may have negative effects on its growth and survival. Moreover, its efficiency of food waste degradation may also be affected by plastics. In addition, salt (NaCl) can also be present in high concentrations, which also reduces the efficiency of H. illucens-mediated food waste treatment. In this study, we assessed the growth of black soldier fly larvae (BSFL) reared on food waste containing polyethylene (PE) and polystyrene (PS) and NaCl. The weight of BSFL was measured every 2-4 days. Survival and substrate reduction rates and pupation ratio were determined at the end of the experiment. Results: The total larval weight of Hermetia illucens reared on food waste containing PS was greater than that of the control on days 20 and 24. However, the survival rate was lower in the group treated with 5% PS, as was substrate reduction in all PS-treated groups. The weight of BSFL reared on food waste containing PE was lower than that of the control on day 6. PE in food waste did not affect the survival rate, but the pupation ratio increased and substrate consumption decreased with increasing PE concentrations. Regardless of the plastic type, the addition of NaCl resulted in decreased larval weight and pupation ratio. Conclusions: Larval growth of black soldier fly was inhibited not by plastics but by substrate salinity. Additional safety assessments of larvae reared on food waste containing impurities are needed to enable wider application of BSFL in vermicomposting.

• 생물환경조절학회지
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• 제33권2호
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• pp.114-119
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• 2024

암면은 우수한 물리화학적 특성을 가지고 있어 작물 재배 생산에 많이 사용된다. 그러나 높은 구매 비용과 폐기가 용이하지 않다는 단점이 있다. 배지의 재사용은 이러한 단점을 보완할 수 있다. 배지는 재사용 시 소독 및 재수화 과정을 거쳐야 하며, 이 과정에서 발생되는 다양한 물리화학적 변화 또한 고려하여야 한다. 본 연구는 두 가지 암면배지(재사용, 미사용)의 물리적 특성을 비교하고, 재사용 암면 배지의 재수화 과정에서 발생하는 화학적 특성 분석을 통해 암면 배지의 재사용 가능성을 판단하고자 하였다. 배지 물리화학성 비교 실험은 2023년 3월부터 8월까지 토마토 재배에 사용된 암면배지와 미사용 암면배지를 이용하여 진행되었으며, 재배 기간 동안 암면에 공급된 배양액의 전기전도도와 pH는 각각 1.8-3.5 dS·m^-1, 5.8-6.0이었다. 배수시간 및 배수량은 관수모니터링 시스템 상단 및 하단에 설치된 로드셀을 통해 측정되었다. 암면배지의 물리적 특성 비교에서 무게와 밀도는 재사용 암면배지에서 높은 경향을 보였으며, 포수 후 평균 배수 시간은 재사용 암면이 미사용 암면에 비해 1.5배 늦었다. 암면 배지의 부분별 염류 농도는 재사용 암면배지가 미사용 암면배지에 비해 낮게 나타났다. 관수 시간에 따른 배액의 전기전도도 변화는 배수가 시작되는 시점에서 가장 컸으며, 배액의 양이 증가할수록 급속하게 작아지는 경향을 보였다. 위 실험 결과를 통해 관수시간 및 관수량과 배액의 전기전도도 변화율은 exponential decay한 관계를 보였다.