• Journal of Biosystems Engineering
• /
• 제30권2호
• /
• pp.121-126
• /
• 2005

In this study, a commercial electronic nose system was used to detect contamination of Salmonella bacteria. Odors from growth media contaminated with Salmonella typhimurium, Salmonella enteritidis, or Escherichia coli were collected and analyzed to evaluate a possibility of rapid detection of pathogen. Odor chromatograph showed that S. typhimurium, S. enteritidis, and E. coli had 7,6, and 9 main peaks, respectively. Retention time and intensity of the peaks were distinct for different bacteria species. Principal component analysis (PCA) were also performed to clarify odor differences. Analysis results showed that the odors for uncontaminated growth medium were differently grouped from the odors of contaminated one. The odor from the bacteria growth identified with two principal components, PC 1 and PC2. In PCA figures, odor groups were moved from left to right of PC 1 with elapse of the bacteria growth time. The electronic nose system could detect odors of S. typhimurium, S. enteritidis, E. coli when their concentration were $1.85\times10^6\;cfu/g,\;2.25\times10^6\;cfu/g,\;and\;1.8\times10^5 cfu/g$, respectively.

• 분석과학
• /
• 제8권4호
• /
• pp.561-568
• /
• 1995

Two methods, precipitation and ultrafiltration, were applied in order to recover platinum group metals(PGM) by complexing them with water-soluble polyelectrolytes, e.g., polyethyleneimine [PEl], poly(2-vinylpyridine) [2-PVP], poly (4-vinylpyridine) [4-PVP], and poly (styrene sulfonic acid) [PSSA]. In the precipitation method, the PGM-polyelectrolyte complex that was formed by mixing first with polybase, e.g.,4-PVP at pH 1 was precipitated by further mixing with polyacid, e.g., PSSA. However, the recovery of PGM obtained by this method was not quantitative(less than 70%). The "sandwiching" binding between the metal anions and two polyelectrolytes was examined by X-ray photoelectron spectroscopy(XPS). The XPS studies indicated that the PGM atom was bound with the acdic and basic polyelectrolyte via its oxygen and nitrogen atom, respectively. The recovery of PGM using polyelectrolyte was further studied by ultrafiltration methods as follows : The PGM ions, eomplexed at pH 1 with polyelectrolyte, allowed the applicntion of membrane filtration by virtue of the great differences in molecular weights between PGM and other low molecular weight species. By applying this method, Pd and Pt (ca. $10^{-4}M$) were selectively separated almost quantitatively from coexisting metal ions, e.g., $Cu^{2+}$ and $Ni^{2+}$. The EPR spectra and viscosity measurements indicated that these polyelectrlytes were not bound to $Cu^{2+}$ and $Ni^{2+}$ ions at this pH, which provided the basis for selective separation of PGM(Pd, Pt and Rh) from these coexisting ions.

• 한국작물학회지
• /
• 제52권3호
• /
• pp.341-347
• /
• 2007

Chinese milk vetch (CMV) is a winter legume that is commonly used as cover crop in Korea. Kill date of cover crop for addition into soil affects N content in cover crop and N availability in soil. This study was conducted to evaluate the effect of CMV as green manure cover crop according to kill dates before growing corn without artificial fertilizer. Top of CMV cut three times on 13 April, 27 April, and 11 May were added into soil at a rate of 600 kg per 10a. Sugar content in CMV litter was persistently decreased from mid-April to late-May. The decrease of sugar content might be due to the transformation into starch and/or other storage or structural constituents. The decreased amount of sugars was greater than 12% and the increased amount of starch was less than 0.2%. Concentration of $NH_4^+$ in soil treated by CMV litter cut on May 11 was slightly higher than that in the treatment with early-cut (April 13) CMV, the concentration at 28 and 49 DAT (days after treatment) was higher in the treatment with late-cut CMV litter. Regardless of cut (kill) date of CMV, the phosphatase activity in the treatment of CMV litter was higher compared to the untreated control. Soil dehydrogenase activity was increased steadily by addition of CMV litter implying total microbial activities in the soil were increased. Our results demonstrate that the status of cover crop species at kill date is an important factor influencing soil enzyme activities derived from microorganisms. Therefore, the optimal kill date of cover crop should be examined to improve the efficiency of cover crop as green manure crop regarding the practical sequence in cropping system.

• 한국식품위생안전성학회지
• /
• 제13권2호
• /
• pp.94-98
• /
• 1998

항암 효과가 뛰어난 건강식품으로 알려진 아가리쿠스 버섯은 많은 약리 성분을 함유하고 잇는 것으로 알려져 있다. 아가리쿠스 버섯의 주요성분을 동정하기 위하여 우선 일반성분을 분석하고 그것을 약리성분 분석의 기초 자료로 이용하고자 하였다. 건조 아가리쿠스 버섯의 일반성분은 일본산 아가리쿠스 버섯과 큰 차이는 없었으나, 당질의 함량이 일본산이 41.56% 인 반면 , 한국산 5.40%로 매우 낮게 나타났다. 무기물의 조성은 일본산 K, Phosphate, Si, Chloride 그리고 Mg 이 각각 56.49%, 12.7%, 12.25%, 4.26%, 2.67%의 순으로 나타나 있는데 반해, 본 실험에서 사용한 한국산 아가리쿠스 버섯의 무기물 조성 함량은 K, Phosphate, Si, Chloride 그리고 Sulfate가 각각 45.77%, 27.78%, 8.16%, 7.80%의 순으로 나타났다. 아미노산은 cysteine을 제외한 16종의 아미노산이 모두 존재하는 것으로 나타났으며, 아미노산중 glutamic acid 가 19.33%로 가장 많이 함유된 것으로 나타났다. 지방산은 linoleic acid가 78.3%로 지방산의 대부분을 이루고 있는 것으로 나타났으며, 그 중 불포화 지방사의 함량은 일본산 아가리쿠스 버섯이 70.5%인데 반해, 한국산 아가리쿠스 버섯의 함량은 80.7%로 일본산 아가리쿠스 버섯보다 다소 높게 나타났다.

• 환경생물
• /
• 제17권2호
• /
• pp.147-152
• /
• 1999

본 연구에서는 현재 국내에서 사용되고 있는 이분해성 미생물 분해성 시험방법의 문제점을 제시하고 이를 해결하거나 보완할 수 있는 방법을 제안하고자, OECD지침서에 등재된 6가지 이분해성 시험방법 중 시험물질의 선정에 제한이 없는 MITI(I), manometric respirometry, closed bottle test에 대하여 8개 화학물질을 대상으로 비교시험 하였다. 현재 국내에서는 MITI(I)법을 사용하고 있는데 이 방법은 접종미생물의 준비과정과 배양유지에 많은 시간과 비용을 요구하며, 배양과정을 통해 미생물의 종이 단순화되는 단점을 지니고 있다. 접종 미생물의 채취와 화학물질의 선택에 제한이 없는 새로운 방법으로는 manometric respirometry법을 들 수가 있는데, 시험방법의 용이성과 경제성, 재현성 등을 모두 고려할 때 가장 적합한 방법이라고 사료된다.

• 한국환경복원기술학회지
• /
• 제11권3호
• /
• pp.50-61
• /
• 2008

Environmental factors and phragmites growth properties at various habitats in Eulsukdo ecological park were investigated to understand major factors affecting phragmites distribution in constructed wetlands. Although phragmites is very important species in wetland ecosystem, it should be controlled to prevent excessive expansion within the restricted park area. The results showed that phragmites dominant sites have the highest LAI among other emerged plants habitats and could adversely affect for waders habitats. Phragmites were also found at the areas with wide ranges of water-depth than other plants, and showed phragmites could be favored for occupying the newly constructed wetlands like Eulsukdo ecological park. The results showed difference in soil redox potential between phragmites dominant and non-dominant sites. Because soil redox potential is affected by wetland hydrology like flooding duration, control of wetland hydrology should be considered for creation and management of constructed wetlands. The results also showed that differences in soil cation exchange capacity, soil salinity, soil organic matter content and site inclination between phragmites dominant and non-dominant sites as well as brackish and freshwater areas. Those abiotic factors can be important considerations for the sustainable wetland management especially for the phragmitest managements in the ecological park.

• 한국환경복원기술학회지
• /
• 제13권2호
• /
• pp.114-123
• /
• 2010

The Environmental Conservation Value Assessment Map (ECVAM) is a five grade assessment map created with nationally integrated environmental information and environmental values. The map is made through the evaluation of 67 items, including greenbelt area and bio-diversity. The ECVAM assesses the stability of the community using forest maps. However, the existing assessment method is problematic because the assessment grades are evaluated using higher than practical values; in part because it uses even-valued overlay and minimal indicator methods. This study was performed in order to suggest an integrated assessment method that could complement the stability evaluation based on existing methods. Accordingly, this study added forest type information, including whether the forest was natural or artificial, to the overlay method using forest diameter maps and forest density maps. As a result, the proposed ECVAM indicated a drastic grade change. After applying the method in South Korea, Grade I areas decreased 12.1%, from 52.6% to 40.6%, Grade II areas increased 11.9%, from 17.4% to 29.2%, and Grade III areas increased 0.2%, from 17.1% to 17.4%, respectively. From the results of the field survey, we found differences between natural forest and planted forest with regard to the number of mortality, species of shrubs, and vine cover. This means that natural forests are more stable than planted forests. This study suggests an improved assessment methodology to complement the existing EVCAM method. The results are expected to be used in environmental evaluations and forest conservation value assessments in ecology and environmental fields.

• 한국초지조사료학회지
• /
• 제14권4호
• /
• pp.288-294
• /
• 1994

Birdsfoot trefoil(MO-20)과 tetraploid narrowleaf trefoil(PI302921)및 이들 종간 잡종의 유식물 확력을 건물축적량 광합성율 생장분석 등을 통하여 비교검토하였다. 일반적으로 종간 잡종의 표현형은 그 들 부모의 중간 특성을 나타내었으며, 암호흡, 광합성 및 휴식물생육은 이 들 모계 계통인 MO-20 birdsfoot trefoil과 유사하였다. 중간잡종은 birdsfoot trefoil 보다 빨리 자랐으나 통계적인 유의성은 없었다. 또한 교잡종은 narrowleaf trefoil보다 유식물 활력이 더 우수하였는데 그것은 낮은 암호흡율과 높은 상대성장율에 기인되었다. 앞으로 birdsfoot trefoil의 유식물 활력의 유전적인 개량은 새로운 분야로서 개량의 여지가 많음을 보여 주었다.

• 한국식품위생안전성학회지
• /
• 제25권2호
• /
• pp.129-132
• /
• 2010

The epidemiology of reported food-borne disease (FBD) outbreaks from 2001 to 2008 in Korea nd Japan were compared in this study. The outbreak rate of FBD in Japan was significantly higher although the average umber of patient in each outbreak in Korea was much higher. In both countries, summer was the season when most FBD outbreaks occurred. The comparison study revealed that FBD outbreaks in spring were more frequent in Korea, and outbreaks in winter were more frequent in Japan. Almost half of FBD outbreaks were observed at restaurants in both countries while FBD outbreaks at schools and work-places in Korea were much higher than in Japan. The most frequent cause of bacterial FBDs in Korea was pathogenic Escherichia coli followed by Salmonella species. On the other hand, Campylobacter jejuni was the most frequent source of bacterial FBDs in Japan. Norovirus, which is elated to uncontrolled hand hygiene and involvement of ill food workers, was the main cause of viral FBDs in both countries. In conclusion, there are common epidemiological characteristics as well as several differences in FBD outbreaks of Korea and Japan. These are suggested to be originated from the characteristic of climate, food sources, and life styles in two countries. Establishment of stricter control and surveillance system for FBD outbreaks are required or prevention and reduction of FBD outbreaks in both countries.

• 한국식품영양학회지
• /
• 제31권2호
• /
• pp.229-235
• /
• 2018

Ramie (Boehmeria nivea M.) has been used for fiber materials in Korea traditionally, but in recent years, the concern with ramie leaves for the food industry such as tteok (a kind of Korean rice cake) industry has been increasing, so a study for eatable ramie is required for the expansion of ramie consumption. Moreover, the ramie varieties for the food industry are not established, so the natural species are cultivated in general; therefore, it is very important to select the ramie varieties for the food industry such as rice cakes, tea, beverage and so on. This study was undertaken to compare the physiochemical properties among 9 ramie lines selected in the Yeonggwang-gun Agricultural Technology Center to select the eatable ramie varieties for the food industry. The contents of the protein among 9 ramie lines was 6.21~7.56% and had the highest content in the YG55. The folic acid (folate) and vitamin C content had varying differences among the 9 lines; the content of folate showed $771.52{\sim}1,978.84{\mu}g%$, that of vitamin C showed 149.42~275.34 mg%. The ACE inhibitory activity appeared to be the highest in YG88 (21.5%) among the 9 ramie varieties tested.