• 분석과학
• /
• 제15권5호
• /
• pp.459-465
• /
• 2002

본 연구에서는 금속가공유 (metalworking fluids, MWF)를 취급하는 사업장에서 채취한 벌크시료와 공기중 시료를 대상으로 엔도톡신 (endotoxin)의 정확한 분석을 위한 Optical Density (OD)의 설정조건을 검토하였다. OD값을 설정하는 Onset time방법이 "time to $V_{max}$"방법보다 재현성, 정확성이 높았다. 구체적인 OD설정값은 "0.03"이 가장 적정한 것으로 나타났다. 검량선의 상관계수 (직선성)가 0.998로서 가장 높았고 회수율도 88% - 105% (0.05 EU/mL과 5 EU/mL 범위)로서 다른 OD값 (OD "0.05", OD "0.1", "time to $V_{max}$")보다도 적정하였다. Onset time방법에서 설정해야 할 OD값은 "0.03"과 "0.05"이 적정한 것으로 나타났다. OD "0.03"과 "0.05"에 의한 엔도톡신 분석결과간의 상관계수 ($\gamma$)는 MWF시료에서는 0.97 그리고 공기 중 시료에서는 0.99로 유의하게 나타났다. 따라서 금속가공유를 대상으로 엔도톡신을 분석할 때는 Onset time 방법을 선택하고 구체적인 OD설정 값은 "0.03"과 "0.05"중에서 검량선의 상관성 (linearity)이 0.98 이상을 나타내는 OD값으로 분석하는 것이 적정한 것으로 판단된다.

• 한국안전학회지
• /
• 제31권5호
• /
• pp.1-6
• /
• 2016

The performance of a set of low-cost optical components used for measuring the optical density of PM particles was evaluated in the present study. To this end, the set of low-cost optical components was replaced with that of general optical components used to measure the PM optical density under identical experimental conditions. The optical densities measured from the set of general optical components were then compared to those obtained from the set of low-cost optical components. While the optical density is measured, another key parameter, the dimensionless extinction constant of PM particles (which is needed to optically measure the PM concentration) was also determined in the present study. The experimental results indicate that the optical density and PM concentration measurements performed by low-cost optical components are feasible, producing trackable variations in the OD and concentrations compared to values obtained from the set of general optical components.

• Journal of Microbiology and Biotechnology
• /
• 제22권7호
• /
• pp.967-974
• /
• 2012

Cultivation of Spirulina platensis using ammonium salts or wastewater containing ammonium as alternative nitrogen sources is considered as a commercial way to reduce the production cost. In this research, by analyzing the relationship between biomass production and ammonium-N consumption in the fed-batch culture of Spirulina platensis using ammonium bicarbonate as a nitrogen nutrient source, an online adaptive control strategy based on optical density (OD) measurements for controlling ammonium feeding was presented. The ammonium concentration was successfully controlled between the cell growth inhibitory and limiting concentrations using this OD-based feedback feeding method. As a result, the maximum biomass concentration (2.98 g/l), productivity (0.237 g/l d), nitrogen-to-cell conversion factor (7.32 gX/gN), and contents of protein (64.1%) and chlorophyll (13.4mg/g) obtained by using the OD-based feedback feeding method were higher than those using the constant and variable feeding methods. The OD-based feedback feeding method could be recognized as an applicable way to control ammonium feeding and a benefit for Spirulina platensis cultivations.

• Journal of the Optical Society of Korea
• /
• 제15권3호
• /
• pp.310-317
• /
• 2011

Perceptibility and acceptability are the most often used threshold units in the field of color science. The former refers to a just perceptible difference and the latter evokes a tolerable color difference. Such thresholds can be very significant to color quality control processes in the printing industry and should be defined in quality measure units. Optical density (OD) and color difference models are usually utilized as color quality measures and have been provided in a considerable number of commercial measuring devices such as spectrophotometers. However, their merits and traits are far less understood in the literature. The present study intends to evaluate performance of those color quality measures including the OD and widely known color difference models, e.g. ${\Delta}E{^*}_{ab}$, ${\Delta}E_{CMC(l:c)}$ and ${\Delta}E{^*}_{00}$. A set of psychophysical assessments were carried out in order to accumulate the perceptibility and acceptability thresholds data, and their central trend was compared with the color quality measure estimates.

• 한국어병학회지
• /
• 제37권1호
• /
• pp.9-15
• /
• 2024

An enzyme-linked immunosorbent assay (ELISA) with two Novirhabdovirus antigens (viral hemorrhagic septicemia virus, VHSV and infectious hematopoietic necrosis virus, IHNV) was used to detect specific antibodies against VHSV from olive flounder (Paralichthys olivaceus) sera. In ELISA plates with VHSV culture supernatants (VHSV-Ag plate), optical density (OD) values for sera from olive flounder with VHS history (VHS sera) ranged from 0.64±0.36, and those of sera from fish without VHS history (non-VHS sera) ranged from 0.26±0.26. In IHNV-Ag plate, the OD values (0.43±0.28) for VHS sera were quite low compared to those in VHSV-Ag plates, while the OD values for non-VHS sera were almost similar. When the OD values for each serum were calculated by subtracting the OD values in the IHNV-Ag plate from those in the VHSV-Ag plate, the corrected OD values were significantly different between VHS sera and non-VHS sera. The results were completely in line with fish histories of VHS epizootics. It was considered that the corrected OD values may represent the true values recognized by VHSV-specific antibodies.

• 한국미생물·생명공학회지
• /
• 제45권2호
• /
• pp.149-154
• /
• 2017

본 연구에서는 Bacillus 유래 esterase를 생산할 수 있는 재조합 대장균을 사용하여 유가식 배양을 이용한 고농도 균체 배양을 통해 esterase 생산성을 극대화하고자 하였다. 유가식 배양 중 순수 산소의 공급을 통해 용존산소를 30% 이상 유지한 경우와 포도당농도를 1 g/l 이상 유지한 경우 각각 $OD_{600}$ 76 (35.8 g/l DCW)과 $OD_{600}$ 90 (42.4 g/l DCW)까지 균체량을 증가시킬 수 있었다. 포도당의 공급에도 불구하고 배양 후반에 세포의 성장이 정체되는 현상을 극복하기 위해 yeast extract가 강화된 추가 배지의 공급을 시도하였으며, 그 결과 $OD_{600}$ 185 (87.3 g/l DCW)까지 고농도 균체 배양이 가능함을 확인하였다. 단백질 생산 수율의 향상을 위해 성장 시기에 따라 induction에 의한 세포 성장과 esterase 생산성을 평가하였고, 그 결과 대수 성장기 후반에 induction을 유도한 경우 세포 성장 측면에서는 최대 $OD_{600}$ 190(89 g/l DCW)까지 고농도 균체 배양이 가능함을 확인하였다. Esterase 생산성 측면에서는 대수 성장기 초반에 induction 을 유도한 경우에 비해 최대 5.8배 생산성이 증가됨을 확인할 수 있었다. 따라서 본 연구를 통해 순수산소와 질소원의 공급을 통해 확립된 대장균 고밀도 배양방법을 기초로 IPTG 유도시간을 최적화 함으로써 Bacillus 유래 esterase의 최대 생산성을 확보할 수 있는 배양방법을 확립하였다.

• 전자공학회논문지A
• /
• 제28A권9호
• /
• pp.721-728
• /
• 1991

In this paper, a magneto-optic modulator has been designed by using single crystal BSO and polycrystal ZnSe as Faraday cells. And practical core-type optical current sensors using pure iron and permalloy have been prepared and experimented. In order to obtain efficient magnetic field detection, LED(NEC OD08358, 0.87 $\mu$m) was used as optical source, PIN-PD(OD-8454)as optical receiver and multi-mode optical fiber (100/140$\mu$m) as transmission line. The characteristics matrix of the optical element was calculated by Stokes parameter, and optic modulation characteristics equations were derived by Muller matrix. Electromagnetic analysis program (FLUX 2D, micro VAX 3600) by finite element method was used to find the magnetic flux density around the core. The measuring error of the output voltage to input current has been masured below 5% in the range of 50A to 1000A. As the temperature was changed from -20$^{\circ}C$ to 60$^{\circ}C$, the maximum measurement error of the optical output has been found to be 0.5% at 60$^{\circ}C$. These experimental results show good temperature and linearity characteristics. The SNR of the overall system was 47dB in case of 600A (250.2 Oe) conductor current and the system has good noise immunity.

• 약학회지
• /
• 제43권6호
• /
• pp.793-797
• /
• 1999

Salmonella typhi Ty21a is an attenuated strain of S. typhimurium and used for oral typhoid vaccine. In an attempt to increase the stability of Ty21a manufacturing typhoid vaccine, we studied about the stability of freeze-dried Th21a including additives at various temperature conditions. In order to investigate the freeze-drying rate of Ty21a according to various absorbance, we lyophilized Ty21a by using 8% sucrose as a stabilizer. The optimal freeze-drying rate of Ty21a was appeared when OD (optical density) value of the growth was between 2.5 and 3.0. To investigate the stability of Ty21a at various temperature, the viability was measured after storaging the freeze-dried Ty21a at the room temperature, cold and freezing condition for 1 week. The viability of Ty21a in cold and freezing storage condition was 5 times more stable than in room temperature. To search the most stable additives for the freeze-dried Ty21a, the viability of Ty21a including additives at the various storage condition was estimated. Mannitol and loctose were the most stable additives. Theses results suggest that the OD value of Ty21a growth, low temperature, mannitol and lactose are important factors for the optimal freeze-drying rate, the stable storage and the most stable additives, respectively.

• Parasites, Hosts and Diseases
• /
• 제28권4호
• /
• pp.207-212
• /
• 1990

이락촌폐흡충(Paragonimusiloktsuenensis) 감염 흰쥐 혈청의 항체 생산을 효소면역 반응 (enzyme-linked immunosorbent assay: ELISA)으로 관찰하였다. 이락촌폐흡충의 피낭유충을 흰쥐 에 감염시킨 후 격주로 12주까지 채질한 혈청과 이락촌폐흡충 성충 추출 조항원의 반응, 면역교차 반응의 유무를 알기 위해 동혈청과 폐흡충(P. westermani) 조항원(PWA) 및 간흡충(Clonorchis sinensis) 조항원(CSA)의 반응을 ELISA의 OD값(optical density value)으로 측정하였다. 감염강도 별 혈청군(GI, GII, GIII, 및 GIV)은 회수된 충체수로 구분하였다. 이락촌폐흡충 감염 횐쥐 혈청은 동항원(PIA)과의 반응에서 감염 후 4주에 전 감염 개체의 평균 OD값이 대조 혈청과 유의한 차이를 나타내어 항체 양성 반응이 인정되었고, 조사된 12주까지 점차 OD간의 증가로 항체가의 증가를 나타내었다. 감염강도별로 구분한 군별 평균 OD값의 수치는 대체로 감염강도와 비례되었으나 감염 6주 이후 군별 OD값의 유의성은 없었고, 개체별 OD값은 보유충체 수에 비례하지 않는 개체들이 많았다. 이락촌폐흡충 감염 횐쥐 힐청은 폐흡충(p. westermani) 조항원(PWA) 및 간흡충(C. sinensis)조항원(CSA)과의 반응(ELISA)에서도 상당한 면역교차 반응을 나타내었다.

• 대한한방부인과학회지
• /
• 제20권2호
• /
• pp.124-138
• /
• 2007

Purpose: This study was conducted to investigate the antimicrobial effects of the interior warming herbs on vaginal microbes. Methods: Staphylococcus aureus, Methicillin-resistant Staphylococcus aureus, Candida albicans and Gardnerella vaginalis were used for vaginitis-induced microbes. Lactobacillus gasseri, Streptococcus spp. and Escherichia coli HB101 were used for normal vaginal florae. And herbs for warming the interior (Zingiberis Rhizoma, Alpiniae Officinari Rhizoma, Aconiti Tuber, Anethi Fructus, Evodiae Fructus, Cinnamomi Cortex Spissus, Caryophylli Flos, Aconiti Tube, Zanthoxyli Pericarpium, Piperis Longi Fructus, Piperis Nigri Fructus) were used in this study. Antimicrobial activities were tested by the change of optical densities (OD) and colony test in vitro. Results: In the results of vaginitis-induced microbes, Anethi Fructus was decreased the OD values on MRSA and Gardnerella vaginalis and Aconiti Tuber was decreased on MRSA. There were no viable MRSA and Gardnerella vaginalis colony forming against Evodiae Fructus, Staphylococcus aureus and MRSA colony forming against Piperis Longi Fructus, Staphylococcus aureus colony forming against Piperis Nigri Fructus and MRSA colony forming against Zanthoxyli Pericarpium. In the results of normal vaginal florae, Zingiberis Rhizoma was decreased the OD values on Streptococcus spp. and all normal vaginal florae were showed viable colony forming against all experimental herbs. Conclusion: According to these results, we can suggest that some kinds of interior warming herbs have antimicrobial effects on vaginal microbes. So there might be needed to make furthermore studies to seek the herbs which have selective antimicrobial effect on pathologic vaginal microbes.