• Journal of Microbiology and Biotechnology
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• 제26권12호
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• pp.2171-2178
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• 2016

Polyester cloth (PC) was selected as a prospective inexpensive substitute separator material for microbial fuel cells (MFCs). PC was compared with a traditional Nafion proton exchange membrane (PEM) as an MFC separator by analyzing its physical and electrochemical properties. A single layer of PC showed higher mass transfer (e.g., for $O_2/H^+/ions$) than the Nafion PEM; in the case of oxygen mass transfer coefficient ($k_o$), a rate of $50.0{\times}10^{-5} cm{\cdot}s^{-1}$ was observed compared with a rate of $20.8{\times}10^{-5}cm/s$ in the Nafion PEM. Increased numbers of PC layers were found to reduce the oxygen mass transfer coefficient. In addition, the diffusion coefficient of oxygen ($D_O$) for PC ($2.0-3.3{\times}10^{-6}cm^2/s$) was lower than that of the Nafion PEM ($3.8{\times}10^{-6}cm^2/s$). The PC was found to have a low ohmic resistance ($0.29-0.38{\Omega}$) in the MFC, which was similar to that of Nafion PEM ($0.31{\Omega}$); this resulted in comparable maximum power density and maximum current density in MFCs with PC and those with Nafion PEMs. Moreover, a higher average current generation was observed in MFCs with PC ($104.3{\pm}15.3A/m^3$) compared with MFCs with Nafion PEM ($100.4{\pm}17.7A/m^3$), as well as showing insignificant degradation of the PC surface, during 177 days of use in swine wastewater. These results suggest that PC separators could serve as a low-cost alternative to Nafion PEMs for construction of cost-effective MFCs.

• 한국농공학회논문집
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• 제56권3호
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• pp.11-17
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• 2014

We investigated the applicability of steel slag as a capping material in order to minimize phosphorus(P) release into seawater. Steel slag is a byproduct from the iron and steel industries and the use of steel slag has some advantages in respect of both cost and environmental concern. P removal by steel slag were studied in a batch system with respect to changes in contact time and initial concentration. Kinetic adsorption data were described well by pseudo 2nd order model, indicating rate limiting step for P adsorption to steel slag is chemical sorption. Equilibrium adsorption data fitted well to Langmuir isotherm model which describes for single layer adsorption. The maximum P adsorption capacity of steel slag was 7.134 mg-P/L. Increasing the depth of steel slag produced a positive effect on interruption of P release. More than 3 cm of steel slag was effective for blocking P release and 5 cm of steel slag was recommended as the depth for capping of P contaminated marine sediments. Increasing P concentration and flow rate had a negative effect on P removal ratio. It was concluded that the steel slag has a potential capping material for blocking P release from marine sediments.

• 한국조리학회지
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• 제14권1호
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• pp.73-83
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• 2008

The purpose of this study was to investigate purchasing variables in the organic food consumption level in Busan. To achieve this purpose, 240 residential women who are organic food consumers were chosen. Among them, 149 women took part in the study. The questionnaire was composed of three parts: 8 demographic characteristics, 9 organic food purchasing conditions, and 22 purchasing variables. The research was continued from August 20th until September 10th, 2007. To derive the results, descriptive analysis, factor analysis, and ANOVA were used by spss 14.0. To sum up the results, three organic food consumption groups were classified into high, middle, and low consumption levels depending on buying condition for organic material. For the factor analysis, 5 factors were named as confidence, quality, safety, appearance, and economy. On the high consumption level, economy factor was highly important than other groups. In general, price would be a more sensitive factor, so they answered the adjusted price range; 52 participants said under 10%, 22 between 11% and 20%, and 17 over 40%.

• 한국토양비료학회지
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• 제38권2호
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• pp.92-100
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• 2005

본 연구는 퇴비원료로 활용할 수 있는 유기성 자원을 선발할 수 있는 선별체계를 확립하고자 여러 지역 및 산업체를 임의로 선정하여 현재의 규정상 퇴비의 원료로 사용 가능한 물질과 사용 불가능한 물질에 해당되는 유기성 오니를 7종 27점 채취하여 일반성분 함량, 중금속 함량, 유기화합물 함량 등을 조사하였고, 오니 추출물을 이용하여 $Microtox^{(R)}$ 분석 및 상추종자 유근신장에 미치는 영향을 조사하였다. 유기물 함량은 모든 오니에서 79.3-98.0%로 퇴비원료에 규정된 60%를 크게 상회하였고, 전질소 함량은 0.8-2.6% 범위이었다. 철과 알루미늄 함량은 상당히 높았으며, 퇴비원료의 규제기준인 중금속 8종의 경우 아연과 구리함량은 섬유오니에서, 크롬함량은 섬유 및 피혁오니에서, 니켈함량은 섬유, 피혁, 식품, 하수오니 4 (공단지역)에서 그리고 수은함량은 하수오니 3 및 4 (대도시, 공단지역)에서 규제기준치 이상으로 조사되었다. 납, 비소, 카드뮴의 함량은 모든 시료에서 규제 기준치보다 낮았다. HEM 함량은 섬유오니에서 다른 재료보다 월등히 높았으며, PAHs 함량은 제지 오니에서 가장 높았고 그 다음은 피혁오니>하수오니 2 (중소도시)>하수오니 4 (공단지역) 순으로 낮았다. PAHs 함량은 anthracene, phenanthrene, naphthalene, acenaphthene 및 fluorene가 다른 화합물 함량보다 상당히 높았으며, 이들 화합물 함량에서는 제지오니, 피혁오니, 하수오니 2 4 1 (중소도시, 공단지역, 읍 면단위 농어촌지역)에서 다른 오니보다 높았다. $Microtox^{(R)}$ 분석에서 가축분뇨 (돈분뇨), 음식물류 폐기물, 하수오니 1 (읍 면단위 농어촌지역), 식품오니에서 $EC_{50}$ 값이 비교적 높게 나타났으나, 피혁오니, 섬유오니, 하수오니 4 (공단지역)에서 가장 낮은 수치를 보였다. 제지오니, 하수오니 3 (대도시), 식품오니, 피혁오니의 추출물은 상추종자의 유근 신장율을 크게 저해하였다. 따라서 현재 퇴비원료 규제기준인 유기물과 중금속 함량 (8성분) 이외 추가로 일반성분, 미량 중금속, 유해 유기화합물, 생물검정법 및 포장비효시험 등을 이용하여 유망한 유기성 오니의 퇴비원료로 활용 가능성을 검토할 수 있는 방법으로 선별체계를 구축한다면 현재 퇴비원료의 규제기준을 보완할 수 있으며 최종적으로 가장 효과적이고 확실한 검정방법인 작물재배시험을 실시하기 이전에 유용한 유기성 자원의 활용여부를 판별해 낼 수 있으리라 생각된다.

• 한국환경농학회지
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• 제21권1호
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• pp.45-49
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• 2002

하수슬러지 중에 존재하는 HEM에 대해 분석하고, 이를 토양에 사용할 때 발생하는 연간 오염부하량에 대해 추정하였다. 전국의 하수처리장에서부터 수집된 하수슬러지 시료 84점에 대해 분석한 HEM의 평균함량은 27.7$\pm$26.5 g/kg이었고, 최소 1.05에서 최대 194 g/kg을 나타내어 분석시료간에 큰 편차를 보였다. 하수처리장이 위치한 도시의 규모에 따라 5단계로 나누었을 때 HEM의 함량은 광역시, 대도시, 중도시, 소도시, 농촌지역에 각각 22.7$\pm$6.7, 33.3$\pm$25.8, 22.0$\pm$8.7, 31.0$\pm$38.8, 27.7$\pm$25.1 g/kg을 나타내었다. 미국 EPA의 하수슬러지 토양시용량 기준을 적용하여 농경지, 산림, 공공용지, 개량용지로 분류하고 각각 7,000, 26,000, 18,000, 74,000 kg/ha (건물량 기준)를 하수슬러지 최대 사용량으로 가정하여 HEM의 연간 오염부하량을 계산하였다. 건물량 기준으로 시용량이 7,000 kg/ha인 농경지의 경우 최대 1,032 kg/ha의 HEM 부하량을 나타내었고, 개량용지 시용기준인 74,000 kg/ha를 적용한 경우 HEM의 연간 오염부하량은 10,908 kg/ha으로 추정되었다. 그 외 산림기준을 적용할 때는 최대 3,832 kg/ha, 공공용지 기준을 적용할 때는 최대 2,653 kg/ha의 연간 오염부하량이 추정되었다.

• 한국자원식물학회지
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• 제35권6호
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• pp.820-824
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• 2022

Ecologically sustainable means of development is the point to support environmental homeostasis. One of our roles is to find bio-degradable resources that can be substituted for petroleum-based products to effectively abide by the natural viability. To counter the issues of deforestation and preserve biodiversity, it is necessary to produce a non-wood crop that can fulfill the requirement for raw material from which several products can be produced. Kenaf (Hibiscus cannabinus), a member of the family Malvaceae, is showing sufficient potentiality along this road-map. Due to its rich fiber content, it has been used extensively in various fields for long, probably as early as 4,000 BC. At present, kenaf has been used as provider of paper, plastics, fiber glass, biofuel, activated carbon and epoxy composite. This obviously catch one's attention towards its capability to replace petroleum-based products as a whole. Moreover, the plant shows considerable relevance in decreasing pollutants by virtue of its enormous absorption capacity. These multiple applications of kenaf justify its credibility to be the best resource for the better world. The paper presents an overview on its numerous uses reported in the literature that we have investigated and its great potential as a valuable multipurpose crop.

• 한국환경농학회지
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• 제33권4호
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• pp.381-387
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• 2014

BACKGROUND: Garlic (Allium sativum) extract has been allowed as commercial biopesticide material for pesticidal activity in the Environmentally-friendly Agriculture Promotion Act. Nine commercial biopesticides containing A. sativum extract have been marketed in Korea. However, the analytical method of the active substances in these materials has not been studied. METHODS AND RESULTS: Cartridge clean-up method for the determination of dimethyl disulfide(DMDS), diallyl disulfide(DADS), and diallyl trisulfide(DATS) in biopesticides containing A. sativum extract was developed and validated by gas chromatography(GC). The clean-up method was optimized using hydrophilic lipophilic balance (HLB) solid phase extraction(SPE) cartridges for the bioactive sulfides in biopesticides containing A. sativum extract, and the eluate was analyzed to quantify the DMDS, DADS, and DATS using the GC. The developed method was validated, and the LOQ and recovery rates of DMDS, DADS, and DATS were 0.226, 0.063, and $0.051mg\;L^{-1}$ and 80.6, 84.8, and 73.1%, respectively. From the nine commercial biopesticide samples, contents of DMDS, DADS, and DATS were analyzed using the developed method and results showed $2.3mg\;L^{-1}$, respectively. CONCLUSION: The developed method could be used in determining the quality of biopesticides for the manufacture of commercial biopesticides containing A. sativum extract.

• 한국축산식품학회지
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• 제43권6호
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• pp.1150-1169
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• 2023

Edible insects are gaining popularity as a potential future food source because of their high protein content and efficient use of space. Black soldier fly larvae (BSFL) are noteworthy because they can be used as feed for various animals including reptiles, dogs, fish, chickens, and pigs. However, if the edible insect industry is to advance, we should use automation to reduce labor and increase production. Consequently, there is a growing demand for sensing technologies that can automate the evaluation of insect quality. This study used short-wave infrared (SWIR) hyperspectral imaging to predict the proximate composition of dried BSFL, including moisture, crude protein, crude fat, crude fiber, and crude ash content. The larvae were dried at various temperatures and times, and images were captured using an SWIR camera. A partial least-squares regression (PLSR) model was developed to predict the proximate content. The SWIR-based hyperspectral camera accurately predicted the proximate composition of BSFL from the best preprocessing model; moisture, crude protein, crude fat, crude fiber, and crude ash content were predicted with high accuracy, with R² values of 0.89 or more, and root mean square error of prediction values were within 2%. Among preprocessing methods, mean normalization and max normalization methods were effective in proximate prediction models. Therefore, SWIR-based hyperspectral cameras can be used to create automated quality management systems for BSFL.

• 펄프종이기술
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• 제46권5호
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• pp.43-50
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• 2014

The cultivation of agricultural crops results in the generation of agricultural byproducts. Researchers have reported that these materials can be useful in a variety of applications. However, over 50% of them are currently discarded because of the lack of specific technologies in industrial applications. Therefore, effective and specific applications must be developed in order to manufacture high-quality materials using discarded lignocellulosic resources. In this study, we determined the possibility of using kraft pulp from major agricultural byproducts as a raw material for the manufacture of paperboard. Rice husks, peanut husks, and garlic stems were obtained and used to prepare many kinds of kraft pulps by controlling the active alkali, sulfidity, reaction time, and liquor ratio. After the production of these kraft pulps, handsheets were manufactured by mixing them with KOCC. After preconditioning, the physical properties and strengths of the handsheets were measured according to the TAPPI test methods. The shapes, lengths, and widths of the pulp fibers varied according to the type of agricultural byproduct and the kraft pulping conditions. Rice husk and garlic stem pulps manufactured under mild pulping conditions resulted in handsheets of higher bulk than other pulps. Garlic stem pulps manufactured under mild pulping conditions were stronger than rice husk pulps and peanut husk pulps.

• Computers and Concrete
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• 제31권5호
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• pp.385-394
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• 2023

Displacement is an important element for evaluating the stability and failure mechanism of hydraulic structures. Digital image correlation (DIC) is a useful technique to measure a three-dimensional displacement field using two cameras without any contact with test material. The objective of this study is to evaluate the behavior of stacked geotextile tubes using the DIC technique. Geotextile tubes are stacked to build a small-scale temporary dam model to exclude water from a specific area. The horizontal and vertical displacements of four stacked geotextile tubes are monitored using a dual camera system according to the upstream water level. The geotextile tubes are prepared with two different fill materials. For each dam model, the interface layers between upper and lower geotextile tubes are either unreinforced or reinforced with a cementitious binder. The displacement of stacked geotextile tubes is measured to analyze the behavior of geotextile tubes. Experimental results show that as upstream water level increases, horizontal and vertical displacements at each layer of geotextile tubes initially increase with water level, and then remain almost constant until the subsequent water level. The displacement of stacked geotextile tubes depends on the type of fill material and interfacial reinforcement with a cementitious binder. Thus, the proposed DIC technique can be effectively used to evaluate the behavior of a hydraulic structure, which consists of geotextile tubes.