• 한국수학교육학회지시리즈E:수학교육논문집
• /
• 제31권3호
• /
• pp.257-277
• /
• 2017

본 연구의 주된 목적은 크게 두 가지로 나눌 수 있다. 첫째, 최근 수학적 모델링이 강조되는 상황에서 보로노이 다이어그램과 들로네 삼각분할을 주제로 영재교육을 위한 수학적 모델링 프로그램을 개발하는 것이다. 둘째, 본 연구에서 개발한 수학적 모델링 프로그램을 실제 영재교육 수업에 적용한 결과를 분석하여 수학적 모델링 수업을 설계하는 현직교사와 융합형 영재프로그램을 개발하는 영재교사에게 도움을 주고자 한다.

• 신재생에너지
• /
• 제7권3호
• /
• pp.67-73
• /
• 2011

MGT fuelled by landfill gas was tested to asses feasibility of its exhaust gas application for $CO_2$ enrichment. The exhaust gas was analyzed during start-up and normal operation with different MGT load conditions. Due to the changes of air/fuel ratio and combustion mode, $O_2$, $CO_2$, CO and NOx concentration were varied within wide ranges during the MGT start-up. Especially, NOx emissioin level was increased up to 20.01 ppmv. Different tendencies of $O_2$, $CO_2$, CO and NOx concentrations were observed with MGT output changes. $O_2$ and CO concentrations were shown to be decreased and NOx and $CO_2$ concentrations were shown to have opposite trends. NOx emission level (0.8~1.88 ppmv) was very low compared to other types of combustion based power generation equipment. Unburned hydrocarbon emission level was substantially decreased with MGT load increase. Especially, $C_2H_4$ concentration was below the detection limit(0.2 ppmv) around the nominal load condition. The exhaust gas from landfill gas fuelled MGT system was shown to be feasible for $CO_2$ fertilization. Concentrations of major components were within or below the maximum allowable ranges.

• 한국물환경학회지
• /
• 제36권3호
• /
• pp.220-228
• /
• 2020

Anaerobic ammonium oxidation (AMX) is a cost-efficient biological nitrogen removal process. The coexistence of ammonia-oxidizing bacteria (AOB) in an AMX reactor is an interesting research topic as a nitrogen-related bacterial consortium. In this study, a sequencing batch reactor for AMX (AMX-SBR) was operated with a conventional activated sludge. The AOB in an AMX bioreactor were identified and quantified using terminal restriction fragment length polymorphism (T-RFLP) and real-time qPCR. A T-RFLP assay based on the ammonia monooxygenase subunit A (amoA) gene sequences showed the presence of Nitrosomonas europaea-like AOB in the AMX-SBR. A phylogenetic tree based on the sequenced amoA gene showed that AOB were affiliated with the Nitrosomonas europaea/mobilis cluster. Throughout the enrichment period, the AOB population was stable with predominant Nitrosomonas europaea-like AOB. Two OTUs of amoA_SBR_JJY_20 (FJ577843) and amoA_SBR_JJY_9 (FJ577849) are similar to the clones from AMX-related environments. Real-time qPCR was used to quantify AOB populations over time. Interestingly, the exponential growth of AOB populations was observed during the substrate inhibition of the AMX bacteria. The specific growth rate of AOB under anaerobic conditions was only 0.111 d^-1. The growth property of Nitrosomonas europaea-like AOB may provide fundamental information about the metabolic relationship between the AMX bacteria and AOB.

• 한국미생물·생명공학회지
• /
• 제2권1호
• /
• pp.1-7
• /
• 1974

농산페자원을 기질로 하여 섬유소단세포단백을 생산하기 위해 전국에서 수집한 썩은 나무, 퇴비, 토양 등 시료에서 enrichment culture technique으로 172주의 섬유소자화세균을 분리하였다. 이들중 섬유소 자화력이 강한 균 6주를 동정하여 다음 결과를 얻었다. 1. 선별한 6주 중 5주는 Cellulomonas속이었으며 나머지 1주는 Sporocytophaga속이었다. 2. Sporocytophaga속의 세균은 microcyst가 타원형인 S. ellepsospora이었다. 3. Cellulomonas속의 세균들은 C.fimi 1균주, C.gelida 1균주, C. flavigena 2균주 및 C. aurogena 1 균주이 었다. 4. 분리균 C. aurogena는 5탄당인 arabinose 와 xylose를 자화하는 성질이 Bergey's Manual에 수록된 균과 달라 새로운 변종으로 판명되었다.

• Journal of Nutrition and Health
• /
• 제16권4호
• /
• pp.243-252
• /
• 1983

This study was undertaken to invesigate the effect of early nutritional deprivation and environment on neurotransmitter concentrations and behavior in later life. The restoring process of rats fed foods ad libitum after 50% restriction of the casein or the Korean diet during the prenatal and/or the lactating periods was observed. There were two rearing conditions, isolated and enriched, after weaning. Behavioral development was measured by the Y- shaped water maze and the open field test. The neurotransmitters were analyzed after sacrifice at the age of 21 weeks. The results are summarized as follows. 1) The body weight impairment by dietary restriction during the prenatal and lactating periods could be restored within 18 weeks after weaning in case of living in a classical cage. The effect of quantitative restriction was bigger in the Korean diet than in the casein diet. 2) The brain weight was decreased by nutritional deprivation. Environmental enrichment increased it slightly. 3) The concentration of neurotransmitters, norepinephrine, dopamine, and serotonin, were not shown any traces of the dietary restriction at the age of 21 weeks. 4) In the maze test, the deprived rats made more errors than the nourished and the rats fed the Korean diet more than those fed the cascin dict. The environmental enrichment could decrease the number of errors. 5) In the open field test, the dietary deprived groups showed less reaction time, more squares entered in the field, and less number of fecal boli than the nourished among the environmentally isolated rats. However, rats living in the enriched cage without experience of nutritional stress showed the lowest emotionality and the elevated exploratory activity.

• 한국환경보건학회지
• /
• 제30권5호
• /
• pp.455-468
• /
• 2004

The purpose of this paper is to understand the time series and origin of a chemical component and to compare the difference during yellow sand episodes for analysis $PM_{10}$ chemical components in the region of west in Korean Peninsula, 1999-2001. An annual mean concentration of $PM_{10}$ is $29.1\;{\mu}g/m^3$. A monthly mean and standard deviation of $PM_{10}$ concentration are very high in spring but there is no remarkably seasonal variation. Also, water soluble ionic component of $PM_{10}$ be influenced by double more total anion than total cation, be included $NO_{3}^-\;and\;SO_{4}^{2-}$ for the source of acidity and $NH_{4}^+$ to neutralize. Tracer metals of $PM_{10}$ slowly increases caused by emitted for soil and ocean (Fe, Al, Ca, Mg, Na) and Zn, Pb, Cu, Mn for anthropogenic source. According to method of enrichment factor (E.F) and statistics, assuming that the origin of metal component in $PM_{10}$ most of element in the Earth's crust e.g. Mg, Ca, Fe originates soil and Cu, Zn, Cd, Pb derives from anthropogenic sources. The ionic component for $Na^{+}\;Cl^-,\;Mg^{2+}\;and\;Ca^{2+}$ and Mg, Al, Ca, Fe originated by soil component largely increase during yellow sand period and then tracer metal component as Pb, Cd, Zn decrease. According to factor analysis, the first group is ionic component ($Na^+,\;Mg^{2+},\;Ca^{2+}$) and metal component (Na, Fe, Mn and Ni) be influenced by soil. The second group, Mg, Cr also be influenced by soil particle.

• 한국대기환경학회지
• /
• 제16권5호
• /
• pp.453-467
• /
• 2000

The aim of this research is to collect and characterize fine particles (FPM:$\leq$2.5${\mu}{\textrm}{m}$) and coarse particles (CPM: 2.5~10${\mu}{\textrm}{m}$) using a low volume air sampler provided by the IAEA, at urban (Taejon) and rural area(Wonju) for a period of about two years(April 1996 to May 1998) and to promote a use of nuclear analytical techniques for air pollution studies. For the collection of airborne particulate matter (PM(sub)10), the Gent stacked filter unit sampler and polycarbonate membrane filters were employed. The concentration of trace elements in collected APM samples were determined byu instrumental Neutron Activation Analysis. For validation of the analytical data, internal quality control were implemented by using both the comparison of the analytical results of standard reference materials(NIST SRM 1648) and interlaboratory comparison for proficiency test (NAT-3). The standard uncertainty was less than 15% and Z-score of two samples were within $\pm$1. The monitoring of (PM(sub)10) mass concentration and elemental concentrations were carried out weekly. The average mass concentration of (PM(sub)10) in urban and rural areas were 59.2$\pm$36.5$\mu\textrm{g}$/㎥ and 41.4$\pm$23.7$\mu\textrm{g}$/㎥, respectively. To investigate the emission source, the enrichment factors were calculated for the fine and coarse particle fractions at two sites, respectively and these values were classified for anthropogenic and soil origin elements.

• 대한임상검사과학회지
• /
• 제42권2호
• /
• pp.86-91
• /
• 2010

We evaluated the performance of a novel screening test, PBP2a MRSA rapid kit (Dinona Inc., Iksan, Korea), for methicillin-resistant Staphylococcus aureus (MRSA) based on a immunochromatographic assay. The test is able to detect penicillin-binding protein 2a (PBP2a) using the nasal specimens from health care workers. The nasal specimens were obtained from 69 healthcare workers and were incubated in enrichment broth followed eight hours incubatin in BHI with cefoxitin $4{\mu}g/mL$. These broth were tested by PBP2a Rapid Kit. The enrichment broths were also directly tested for tube coagulase using the conventional identification method. 19 of 22 MRSA showed positive results by PBP2a rapid test and direct coagulase test (the sensitivity for detection of MRSA, 86.36%). While, 8 of 47 non-MRSA showed false positive results for the two tests. All of the 8 non-MRSA which showed false positive were co-colonizing isolates with MRCNS and MSSA. In addition, 46 of 49 methicillin-resistant staphylococci (MRS) showed positive results for PBP2a MRSA rapid kit (the sensitivity for detection of MRS, 93.8%), and all of 20 non-MRS showed negative results (specificity, 100%). The combination of PBP2a MRSA rapid kit and direct coagulase test showed the good sensitivity for detection of MRSA from anterior nares but frequently showed false positive results from the co-colonizing carrier with MRCNS and MSSA.

• 한국식품과학회지
• /
• 제31권5호
• /
• pp.1324-1329
• /
• 1999

국내 유통중인 냉동만두와 피자 중 L. monocytogenes의 분포와 분리균의 특성을 조사하기 위하여 1998년 8월부터 11월에 걸쳐 시료 72개를 구입하여 실험하였다. 전체 냉동식품 중 9.7%(7개)에서 L. monocytogenes가 분리되었으며 냉동만두 중 11.1%,피자 중 5.6%가 오염되어 있었다. USDA와 FDA방법. 그리고 modified cold enrichment 방법 중 USDA방법이 가장 L. monocytogenes의 분리율이 높았으며 분리된 L. monocytogenes 혈청형은 4였다. PCR실험결과 CAMP test와 API Listeria kit를 사용하여 분리된 균주가 L. monocytogenes임이 확인되었다. USDA방법과 PCR을 이용하여 L. monocytogenes를 분리하고 확인하는데 3-4일 정도의 시간이 소요되어 시간을 단축시킬 수 있는 분리 및 확인방법의 개발이 필요하리라 사료된다. 분리된 L. monocytogenes의 내열성을 조사한 결과 tryptic soy broth에서 D값이 $60^{\circ}C$에서 49.2초, $65^{\circ}C$에서 8.8초였으며 냉동식품의 안전한 사용을 위하여 L. monocytogenes의 분리율이 높은 식품에서 D값의 측정이 필요하다고 사료된다.

• 한국대기환경학회지
• /
• 제18권2호
• /
• pp.95-112
• /
• 2002

A precision analysis was conducted for the quantification of trace metal levels in airborne particulates using ICP-MS. According to our study the quantitative analysis using Whatman grade 41 filters produces more precise and representative values of metal concentrations than that using EPM 2000 filters. The mean concentration of PM 10 analyzed during 1998 ~ 2000 was 82 $\mu$g/m$^3$. The concentrations of human carcinogens such as As and Cr were 8.65 and 25.87 ng/m$^3$, respectively, while those of probable human carcinogens such as Cd and Pb were 3.13 and 219.46 ng/m$^3$, respectively. Time-weighted mean concentration, calculated using surface wind speed and direction, indicated that there were differences between metals of crustal origin and metals of anthropogenic origin. The rectorial concentrations of anthropogenic metals and PM 10 were higher for north -west sector with calm or low wind speed conditions than for any other sector with high wind speed conditions. On the contrary, the rectorial concentrations of crustal metals were high with high wind speed. In addition, the sectorial concentrations of crustal metals were more affected by south-west wind directions, which were compared with those of anthropogenic metals. The enrichment factor (EF) values of many anthropogenic metals were higher than 50, while those of crustal metals were lower than 3, respectively. The concentrations of Cr and Ni in Daejeon industrial complex area were 11 times higher than those in the background site of Kuopio in Finland, while that of Pb in the complex area was 22 times higher, respectively.