• Korean journal of applied entomology
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• 제45권3호
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• pp.309-316
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• 2006

Three sex pheromone components (cis-8-dodecenyl acetate (Z12Ac), trans-8-dodecenyl acetate (E12Ac), cis-8-dodecenol (Z12OH)) of the Oriental fruit moth, Grapholita molesta, were chemically synthesized. Especially to increase the composition of cis-stereoisomer, a triple bond intermediate was hydrogenated at $-20^{\circ}C$ with catalytic $Pd/BaSO_{4}$. The resulting product consisted of the acetates with a stereoisomer ratio in 92:8 (Z:E). The biological activity of the synthesized pheromone compounds was analyzed both in male responses and orientation disruption. The indoor pheromone effect was determined by male flight behavior showing wing movement in response to lure. Different mixtures of the synthetic pheromone components were prepared by mixing acetate and alcohol components in 100:0, 99:1, and 90:10 (g/g) and tested with a comparison of a standard commercial pheromone lure. The highest pheromone effect was observed in only acetate mixture (100:0) and the effect was reduced with the addition of the alcohol component. This indoor pheromone effect could be observed in field monitoring trial, in which 100:0 mixture showed the highest trap catches. Orientation disruption assay was conducted indoor by using a cage, in which the center had a commercial lure on sticky plate and the four candidates were placed at 6 cm away from the central lure on each of four directions. Test males were released to the arena during overnight (12 h) and then the caught males on the sticky plate were counted. The synthesized pheromone as well as the commercial pheromone showed 100% orientation disruption. However, the orientation disruption effect was reduced with decrease in the number of the surrounding disrupting pheromone baits. These results clearly suggest that the synthesized sex pheromone of G. molesta is biologically active and can be used for field mating disruption.

• KOREAN JOURNAL OF CROP SCIENCE
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• 제47권3호
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• pp.167-173
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• 2002

This experiment was conducted to figure out the change of soil physical properties, rice growth and yield with the years of continuous cultivation in direct dry-seeding and no-tillage machine transplanting. Experiments were conducted at NHAES(National Honam Agricultural Experiment Station, RDA, Iksan, Cheon Buk Province, South Korea) with a rice variety "Dongjinbyeo" from 1995 to 2000. In no-tillage machine transplanting cultivation, organic matter in soil was higher than that on direct dry-seeding and was significantly high in topsoil. Problematic weed species were E. crus-galli B., A. keisak H., and L. japonica M. Plant height and tiller number m-2 were higher in common-tillage during the total growth duration. The highest weedy rice occurrence of 27.5% was observed in live years' continuous direct dry-seeding and followed by 6.2%, in four years', and 3.7%, in three years'. The highest yield reduction of 38% was observed in five years' continuous direct dry-seeding. The reduction may resulted from the competition between weedy rice and cultivated rice.

• Journal of Embryo Transfer
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• 제22권1호
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• pp.15-19
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• 2007

The objective of this study was to investigate the relationship between body condition score (BCS), blood urea nitrogen (BUN) and estrous expression for the purpose of improving reproductive performance. In total, 37 ovulations and 28 estrous detection were observed among 51 Holstein-Friesian dairy cows. The estrous inducement rate and estrous expression rate were significantly lower for cows with BCS below 2.0 than for cows with BCS above 2.0. There was 0% of rate of standing heat in cows with BCS below 2.0 whereas the rate of standing heat was markedly increased in cows with BCS above 2.0 (46.7% and 64.7% for BCS $2.0{\sim}2.49$ and BCS $2.5{\sim}3.0$ cows, respectively). The estrous expression rate was significantly lower for cows with BUN below 10mg/dl than for cows with BUN above 10mg/dl. There was no significant difference among duration time of estrus, estrous behavior patterns and BUN concentration. The rate of estrous expression and concentration of BUN was not significantly different between primiparous and multiparous cows. This result shows that the level of BCS and BUN affect the estrous expression. Considering the situation that estrous expression is decreased in recent years, effective nutritional management should be accompanied to improve reproductive performance.

• Journal of Korean Society on Water Environment
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• 제22권6호
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• pp.1101-1106
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• 2006

Many BNR (Biological Nutrient Removal) plants have experienced a bulking problem, mainly due to the growth of filamentous organisms, particularly during the winter months. This study investigated the problem of bulking due to the growth of M. parvicella both at a full-scale municipal wastewater treatment plant and a pilot scale plant located in the C city. The full-scale facility was operated at a flow rate of $51,000m^3/d$, an F/M (Food-to-Microorganism) ratio of 0.12 kgBOD/kgMLVSS/d and an SRT (Solids Retention Time) higher than 25 days, respectively. This plant experienced bulking and foaming problems at low temperatures below $15^{\circ}C$ since it was retrofitted with the BNR system in 2003. The pilot plant employed had an identical process configuration as the full scale one and used the same wastewater source. It was operated at a flow rate of $3.8m^3/d$, temperatures between 10 to $25^{\circ}C$ and SRTs between 10 and 25 days. At full scale, the M. parvicella growth and SVI (Sludge Volume Index) patterns were studied in conjunction with temperature variations. At pilot scale, DO and SRT variations were also explored, in addition to the filamentous bacteria growth and SVI patterns. During the full-scale investigation, over a 3 year period, it was noted that the SVI was maintained within acceptable operational values (i.e. under 160) during the summer months. Moreover settling in the secondary clarifiers was good and was not affected by the presence of M. parvicella. In contrast, at low mean temperatures during winter, the SVI increased to over 300. Overall, as the temperature decreased, the predominance of M. parvicella became apparent. According to this study, M. parvicella growth could be controlled and SVI could drop under 160 by a change in operational conditions which involved an increase in DO concentration between 2 and 4 mg/L and a decrease in SRT to less than 20 days.

• Korean Journal of Veterinary Research
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• 제50권3호
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• pp.213-220
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• 2010

Salmonella (S.) Enterica infection ranks among the most common food borne bacterial infections worldwide. Although there are six subspecies of S. Enterica, the vast majority of human and animal infections are caused by strains belonging to subspecies 1 serovar Typhimurium and Enteritidis. Recent reports on antibiotic resistance of Salmonella spp. are rising steadily. The increasing problem of antibiotic resistance has rekindled interest in bacteriophage to therapy. Therefore, we investigated the efficacy of bacteriophage in S. enterica serovar Enteritidis infected mice and pigs by measuring of body condition, body weight, bacterial colonization and weight of organs based on the in vitro analysis. In vitro experiment, phage cultured with S. Enteritidis showed clear lysis pattern, the plaque forming unit (PFU) of our phage culture was $1.5{\times}10^{11}PFU/mL$, and phage showed its maximum activity at 4 h post inoculation. In mouse experiment, there was no significant difference among experimental groups in the general body conditions and body weight of mice. However, there was difference in weight of liver and spleen depending on the experimental group (p < 0.05). The weight of liver and spleen were reduced by the phage treatment. Also bacterial colonization in spleen and liver were significantly reduced by the phage treatment. In pig experiment, the general body conditions and body temperature exhibited not much difference among the pigs except few pigs in group 3 which showed poor body conditions. From the feces in each group, we could isolate the S. Enteritidis only from group 3. Bacterial enrichment culture was necessary for isolating the bacteria from 5 dpi and 10 dpi, however direct isolation was possible from 15 dpi feces. In phage treated group, postmortem lesion was better than non-phage treated group. Recently, antibiotic resistance concerns on the food-borne bacterial pathogens have been increasing because of the wide spread of the antibiotics resistance genes. This concern is widely transmitted to the human related public health. As one of the alternative treatments on the bacterial pathogens, attempt using phages have been made to control the bacterial diseases. The positive possibility of the trail using phage was observed to control the S. enterica serovar Enteritidis in this study even though the further analysis has been remained.

• Tuberculosis and Respiratory Diseases
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• 제53권6호
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• pp.635-643
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• 2002

Background : The Aim of this study was to compare the recovery of mycobacteria from sputum samples of pulmonary tuberculosis patients using the MB/BacT rapid culture system(Organon Teknika, USA) with that obtained using Lowenstein-Jensen solid medium. Methods : The two culture systems were compared using sputum samples of 99 pulmonary tuberculosis patients. Culture media were incubated at $35-37^{\circ}C$ for six weeks in the MB/BacT system and for 12 weeks in Lowenstein-Jensen solid medium. Solid media were examined macroscopically once a week, and the MB/BacT system positive vials were unloaded from the machine as soon as possible after positive signal from the connected computer was detected Confirmation of growth for mycobacteria was done by Ziehl-Neelson stained smears. Isolates were identified to differentiate Mycobacterium tuberculosis from mycobacterium other than tuberculosis(MOTT) by phenotypic and molecular methods. Results : Of the sputum samples of the 99 patients, 58 samples were smear positive and 41 in negative smear. Mycobacteria were recovered from 67(67.7%) samples by using both culture systems. The yield with MB/BacT was higher than that with Lowenstein-Jensen [67(67.7%) vs. 52(52.5%), p<0.001]. Moreover, 15(15.2%) samples were positive only in the MB/BacT, whereas none of samples was positive only in Lowenstein-Jensen. In smear-positive and smear-negative samples, the recovery rate with MB/BacT was also higher than that with Lowenstein-Jensen [sputum-positive; 56/58(96.6%) vs. 46/58(79.3%), p=0.005, sputum-negative; 6/41(14.6%) vs. 5/41(12.2%), p<0.001]. The mean times to detection of Mycobacteria were 13.3 and 27.2 days with MB/BacT and Lowenstein-Jensen respectively(p<0.001). Conclusion : This results indicate that the the MB/BacT is more efficient and faster than Lowenstein-Jensen for the recovery of mycobacteria.

• The Magazine of the IEIE
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• 제29권6호
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• pp.76-80
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• 2002

'Liquid Crystal의 상전이(相轉移)와 광학적 이방성(異方性)이 1888년과 1889년 F. Reinitzer와 O. Lehmann에 의해 Monatsch Chem.과 Z.Physikal.Chem.에 각각 보고된 후 부터 제2차 세계대전이 끝난 뒤인 1950년대 까지는 Liquid Crystal을 단지실험실에서의 기초학문 차원의 연구 대상으로만 다루어 왔다. 1963년 Williams가 Liquid Crystal Device로는 최초로 특허 출원을 하였으며, 1968년 RCA사의 Heilmeier등은 Nematic 액정(液晶)에 저주파(低周波) 전압(電壓)을 인가하면 투명한 액정이 혼탁(混濁)상태로 변화하는 '동적산란(動的散亂)'(Dynamic Scattering) 현상을 이용하여 최초의 DSM(Dynamic Scattering Mode) LCD(Liquid Crystal Display)를 발명하였다. 비록 150V 이상의 높은 구동전압과 과소비전력의 특성 때문에 실용화에는 실패하였지만 Guest-Host효과와 Memory효과 등을 발견하였다. 1970년대에 이르러 실온에서 안정되게 사용 가능한 액정물질들이 합성되고(H. Kelker에 의해 MBBA, G. Gray에 의한 Cyano-Biphenyl 액정의 합성), CMOS 트랜지스터의 발명, 투명도전막(ITO), 수은전지등의 주변기술들의 발전으로 인하여 LCD의 상품화가 본격적으로 이루어지게 되었다. 1971년에는 M. Shadt, W. Helfrich, J.L. Fergason등이 TN(Twisted Nematic) LCD를 발명하여 전자 계산기와 손목시계에 응용되었고, 1970년대 말에는 Sharp에서 Dot Matrix형의 휴대형 컴퓨터를 발매하였다. 이러한 단순 구동형의 TN LCD는 그래픽 정보를 표시하는 데에는 품질의 한계가 있어 1979년 영국의 Le Comber에 의해 a-Si TFT(amorphous Silicon Thin Film Transistor) LCD의 연구가 시작되었고, 1983년 T.J. Scheffer, J. Nehring, G. Waters에 의해 STN(Super Twisted Nematic) LCD가 창안되었고, 1980년 N. Clark, S. Lagerwall 및 1983년 K.Yossino에 의해 Ferroelectric LCD가 등장하여 LCD의 정보 표시량 증대에 크게 기여하였다. Color화의 진전은 1972년 A.G. Ficher의 셀 외부에 RGB(Red, Green, Blue) filter를 부착하는 방안과, 1981년 T. Uchida 등에 의한 셀 내부에 RGB filter를 부착하는 방법에 의해 상품화가 되었다. 1985년에는 J.L. Fergason에 의해 Polymer Dispersed LCD가 발명되었고, 1980년대 중반에 이르러 동화상(動畵像) 표시가 가능한 a-Si TFT LCD의 시제품(試製品) 개발이 이루어지고 1990년부터는 본격적인 양산 시대에 접어들게 되었다. 1990년대 초에는 STN LCD의 Color화 및 대형화(大型化) 고(高)품위화에 힘입어 Note-Book PC에 LCD가 본격적으로 적용이 되었고, 1990년대 후반에는TFT LCD의 표시품질 대비 가격경쟁력 확보로 인하여 Note-Book PC 시장을 독점하기에 이르렀다. 이후로는 TFT LCD의 대형화가 중요한 쟁점으로 부각되고 있고, 1995년 삼성전자는 당시 세계최대 크기의 22' TFT LCD를 개발하였다. 또한 LCD의 고정세(高情細)화를 위해 Poly Si TFT LCD의 개발이 이루어졌고, 디지타이져 일체형 LCD의 상품화가 그 응용의 폭을 넓혔으며, LCD의 대형화를 위해 1994년 Canon에 의해 14.8', 21' 등의 FLCD가 개발되었다. 대형화 방안으로 Tiled LCD 기술이 개발되고 있으며, 1995년에 Sharp에 의해 21' 두장의 Panel을 이어 붙인 28' TFT LCD가 전시되었고 1996년에는 21' 4장의 Panel을 이어 붙인 40'급 까지의 개발이 시도 되었으며 현재는 LCD의 특성향상과 생산설비의 성능개선과 안정적인 공정관리기술을 바탕으로 삼성전자에서 단패널 40' TFT LCD가 최근에 개발되었다. Projection용 디스플레이로는 Poly-Si TFT LCD를 이용하여 $25'{\sim}100'$사이의 배면투사형과 전면투사형 까지 개발되어 대형 TV시장을 주도하고 있다. 21세기 디지털방송 시대를 맞아 플라즈마디스플레이패널(PDP) TV, 액정표시장치 (LCD)TV, 강유전성액정(FLCD) TV 등 2005년에 약 1500만대 규모의 거대 시장을 형성할 것으로 예상되는 이른바 '벽걸이TV'로 불리는 차세대 초박형 TV 시장을 선점하기 위하여 세계 가전업계들이 양산에 총력을 기울이고 있다. 벽걸이TV 시장이 본격적으로 형성되더라도 PDP TV와 LCD TV가 직접적으로 시장에서 경쟁을 벌이는 일은 별로 없을 것으로 보인다. 향후 디지털TV 시장이 본격적으로 열리면 40인치 이하의 중대형 시장은 LCD TV가 주도하고 40인치 이상 대화면 시장은 PDP TV가 주도할 것으로 보는 시각이 지배적이기 때문이다. 그러나 이러한 직시형 중대형(重大型)디스플레이는 그 가격이 너무 높아서 현재의 브라운관 TV를 대체(代替)하기에는 시일이 많이 소요될 것으로 추정되고 있다. 그 대안(代案)으로는 비교적 저가격(低價格)이면서도 고품질의 디지털 화상구현이 가능한 고해상도 프로젝션 TV가 유력시되고 있다. 이러한 고해상도 프로젝션 TV용으로 DMD(Digital Micro-mirror Display), Poly-Si TFT LCD와 LCOS(Liquid Crystals on Silicon) 등의 상품화가 진행되고 있다. 인터넷과 정보통신 기술의 발달로 휴대형 디스플레이의 시장이 예상 외로 급성장하고 있으며, 요구되는 디스플레이의 품질도 단순한 문자표시에서 그치지 않고 고해상도의 그래픽 동화상 표시와 칼라 표시 및 3차원 화상표시까지 점차로 그 영역이 넓어지고 있다. <표 1>에서 보여주는 바와 같이 LCD의 시장규모는 적용분야 별로 지속적인 성장이 예상되며, 새로운 응용분야의 시장도 성장성을 어느 정도 예측할 수 있다. 따라서 LCD기술의 연구개발 방향은 크게 두가지로 분류할 수 있으며 첫째로는, 현재 양산되고 있는 LCD 상품의 경쟁력강화를 위하여 원가(原價) 절감(節減)과 표시품질을 향상시키는 것이며 둘째로는, 새로운 타입의 LCD를 개발하여 기존 상품을 대체하거나 새로운 시장을 창출하는 분야로 나눌 수 있다. 이와 같은 관점에서 현재 진행되고 있는 LCD기술개발은 다음과 같이 분류할 수 있다. 1) 원가 절감 2) 특성 향상 3) New Type LCD 개발.

• Journal of the Korean earth science society
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• 제36권7호
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• pp.661-673
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• 2015

UBVI CCD photometry of the intermediate age open cluster NGC 7790 has been obtained using AZT-22 1.5 m telescope (f/7.74) at the Maidanak Astronomical Observatory in Uzbekistan. NGC 7790 contains three ${\delta}$ Cep variable stars including CEa Cas, CEb Cas, and CF Cas. PSF photometry was carried out using IRAF/DAOPHOT for all observations. The total number of stars observed both in V and I filter was 1008 and the limiting magnitude was $V{\approx}22$. To determine atmospheric extinction coefficients and photometric zero points, many blue and red standard stars as well as the standard stars in the celestial equator under various airmass were observed. Photometric data were transformed into the standard Johnson-Cousins' UBVI standard system. From the analysis of UBVI color-magnitude diagram and color-color diagram, the color excess in V and I filter [$E(B-V)=0.58{\pm}0.02$], the selective extinction ratio in V and I filter [$R_V{\equiv}A_V/E(B-V)=3.02{\pm}0.09$] and distance modulus ($V_0-M_V=12.65{\pm}0.10$) of the cluster were determined. The age of the cluster was estimated to be log $age=8.05{\pm}0.05$ [yr] based on the position of these three Cepheid variables in the color-magnitude diagram, the isochrone of the Geneva group ($Ekstr{\ddot{o}}m$ et al., 2012-Z=0.019), and the isochrone of the Padova group (Bressan et al., 2012-Z=0.014) were used to compare each other. Of them, the Geneva models that considered stellar rotation well described the position of ${\delta}$ Cepheid variables in the blue loop. Although they were well consistent with standard period-luminosity relation of ${\delta}$ Cepheid variables, three Cepheid variables in NGC 7790 were, on average, brighter by about 0.5 mag than the absolute magnitude estimated from the mean period-luminosity relation at a given period.

• Journal of Korean Society of Forest Science
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• 제104권3호
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• pp.360-367
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• 2015

The present study investigated the habitats of Korean fir trees (Abies koreana E. H. Wilson) on Mt. Baekwun (Baekwun-san), determined the current distribution, quantified the contribution of biological and non-biological environmental factors affecting the distribution, derived actual and potential habitats, presented a plan for the establishment of protected areas, applied RCP 8.5 climate change scenario to analyze the effects of climate change on the future distribution of Korean fir trees, and predicted future potential habitats. According to the results of the study, 3,325 Korean fir trees (DBH >= 2.5 cm) inhabited Mt. Baekwun, and their distribution area was approximately 150 ha. Populations of Korean fir trees were confirmed to exist at an altitude of 900 m above sea level and were distributed up to 1,200 m. Based on potential distribution, areas appropriate for habitation by Korean fir trees were analyzed to be 450 ha, three times the current distribution area, with a focus on Sang Peak (Sang-bong), Eokbul Peak (Eokbul-bong), Ddari Peak (Ddari-bong), and Dosol Peak (Dosol-bong). The forest stands near Sang Peak, the main peak, were evaluated as those with the most appropriate potential for the habitation of Korean fir trees, and populations of the trees tended to prefer the northern slope rather than the southern slope. When climate change scenario RCP 8.5 was applied and future potential distribution was analyzed, the habitats were expected to decrease in area to 20 ha by 2050, with a focus on Sang Peak, and areas appropriate for habitation were predicted not to exist by 2080. Judging from such results, as global warming accelerates, the habitats of Korean fir trees are clearly expected to move from lowlands to highlands.

• Journal of the Korean Society of Food Science and Nutrition
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• 제14권4호
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• pp.370-374
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• 1985

To investigate the flavor components of sun-dried ray, Raja porasc, the contents of such as free amino acids, nucleotides and their related compounds, total creatinine, betaine, TMAO, fatty adds, and volatile compounds were analysed. The content of total free amino acids was 1773.3mg% on dry basis and the abundant amino acids were taurine, lysine, leucine, alanine, glycine, glutamic acid, proline, and valine in order and these amino acids accounted for 80% of total free amino acids in sun-dried ray. In the nucleotides and their related compounds, hypoxanthine was the most abundant. Ammonia-N was the most abundant, resulting 26.4% of extractive nitrogen which was 1965.6mg% and next free amino acid-N, total creatinine-N, and nucleotide-N in order. In the fatty acid composition of total lipid and neutral lipid, polyenoic acid was abundant holding 42.0%, 45.3% respectively. In phospholipid, the ratio of polyenoic acid and saturated fatty acid were similar to 39% respectively. The predominant fatty acids in total lipid, neutral lipid, and phospholipid were $C_{16:0},\;C_{22:6},\;C_{18:1},\;C_{18:0},\;and\;C_{20:4}$. In the volatile compounds, isocaproic acid, caproic acid, isobutyric acid, and butyric acid were the major portion of the 8 kinds of volatile fatty acids detected and 2-butanone, pentanal, and 2-methylpropanal were the major portion of the 8 kinds of volatile carbonyl compounds detected and also trimethylamine was the major portion of 2 kinds of volatile amines detected. It was presumed from the results that the reciprocal action of taste compounds such as free amino acids, nucleotides and their related compounds total creatinine, betaine, and TMAO and volatile compounds such as volatile carbonyl compounds, volatile fatty acids, volatile amines, and ammonia played an important role for the characteristics of flavor of sun-dried ray.