• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.31 no.4
• /
• pp.454-464
• /
• 1986

To find main factors to affect tobacco culture and quality, NC 2326 (Nicotiana tabacum L.) was cultivated in Korea and in the United States under different plant density, fertilization, mulching and curing. Among the chemical characteristics of the both experimental soils, the organic matters were similar concentration in both locations but effective phosphorous contents were higher in Oxford in the United States. Plant height, length and width of the largest leaf, leaf thickness, and midrib ratios were larger in Oxford than in Suwon in Korea. Also they were larger in non mulching system than in mulching system. But the total numbers of the leaves were decreased in non mulching system. The content of nicotine was higher in the plant grown in Suwon than in Oxford. The concentrations of nicotine and sugar tend to increase in mulching system comparing of non mulching system. During the growing, the concentration of non-volatile organic acids was higher in Suwon, while it was lower in cured leaf produced in Suwon. Also the contents of total fatty acids were lower in the harvested leaf grown in Suwon, but not in cured tobacco. Forty three compounds identified among the volatile oils from these experimental samples were quantified. The concentrations of the major components related to the tobacco flavour such as damascone, damascenone, solanone, nor-solanadione, and megastigmatrienones were higher in the cured tobacco produced in Oxford rather than in Suwon.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.51 no.3
• /
• pp.199-203
• /
• 2006

In the late growth stage of rice plant, the growth declines even though they grow well in early growth stage. This phenomenon is called autumn declining and it often accompanies the infection of Helminthosporium leaf spot disease. This study was carried out to identify the related environmental factors and to establish the integrated control system of Helminthosporium Leaf Spot Disease in rice. The total area of infected paddy field by Helminthosporium leaf spot was 470 ha in 2000 and 1,004 ha in 2001, which occupied about 1% of the total paddy area in Gyeongbuk province, Korea. The ill-drained sandy paddy occupied 50% of the total area of infected paddy fields and followed by sandy paddy (28%). Comparing the content of soil elements between infected and normal paddy, it was clarified that the organic matter content of normal was higher than that of infected paddy and the contents of inorganic elements such as Mn, Fe, Zn and available $SiO_2$ were also higher in normal paddy. The results of comparing the inorganic elements between infected and normal rice plants also showed the same results. The contents of inorganic elements such as MgO, $SiO_2$, Fe, Mn were higher in normal rice plants. Especially highly significant difference of $SiO_2$ content on both soil and rice plants was noticeable.

• Membrane Journal
• /
• v.18 no.4
• /
• pp.282-293
• /
• 2008

Partially sulfonated poly(aryl ether sulfone) membranes were prepared from the sulfonated sulfone monomer, which was synthesized by a nucleophilic substitution, non-sulfonated monomers and potassium carbonate by a direct polymerization method and a subsequent solution casting technique with mixed solvents of N-methyl-2-pyrrolidone (NMP) and dimethylacetamide (DMAc). To investigate the effect of mixed solvent, the volume ratios of NMP and DMAc were varied in the range of $0{\sim}100%$ and the degrees of sulfonation of the copolymers were fixed as 50%. The surface properties of the resulting membranes were examined by scanning electron microscope (SEM) and atomic force microscope (AFM), and a comparative study of the morphology changes and the physicochemical properties such as proton conductivity and methanol permeability was achieved. It was found that proton conductivities depend on the volume ratio of NMP-DMAc mixed solvents, and the proton conductivity determined at the condition of $25^{\circ}C$ and 100% relative humidity was $1.38{\times}10^{-1}\;S/cm$ for the membrane prepared in the 50:50 v/v-% of NMP : DMAc mixed solvent.

• Journal of the Korea Concrete Institute
• /
• v.26 no.3
• /
• pp.239-245
• /
• 2014

This study analyzed a comprehensive database including 6331 ready-mixed concrete plant mixtures to quantitatively assess the environmental impact of concrete under mixture proportions variable according to the domestic region and season. The environmental impact indicator includes global warming, photochemical oxidant creation, abiotic resource depletion, acidification, eutrophication and human toxicity, which are determined from categorization, characterization, normalization and weighting process based on Korea lifecycle inventories. The determined environmental impact indicator was also normalized by concrete compressive strength ($f_{ck}$), which is defined as impact index, to calculate the environmental impact per unit strength of 1 MPa. The most common compressive strength of concrete used in the country is estimated to be 24 MPa and 27 MPa. For $f_{ct}$ of 24 MPa, the lowest environmental impact indicator is observed in Ulsan, whereas the highest region is Gwangju and Daegu. This difference according to domestic region is primarily resulted from by the replacement of different supplementary cementitious materials. Furthermore, the impact index of concrete with $f_{ck}$ of 24 MPa is higher by approximately 5% at wintertime than at summertime and standard season. The impact index gradually decreases with the increase of $f_{ck}$ up to 35 MPa, beyond which it remains constant.

• Journal of the Korean Crystal Growth and Crystal Technology
• /
• v.26 no.6
• /
• pp.225-231
• /
• 2016

The valence band maximum (VBM) and conduction band minimum (CBM) of Al-doped GaInAsSb alloys substrated on GaSb are calculated by using an analytic approximation based on the tight binding method. The relative positions of the VBM and CBM between Al-GaInASSb and GaSb determine band alignement type, valence band offset (VBO) and conductin band offset (CBO) for the heterojunctions. In this study, aluminium doping is assumed to be substituted in the cation site and limited up to 20 % because it can easily oxidize and degrade materials. It is found that the Al-doped alloys exhibit type-II band alignments over the entire composition range and make the band gaps increase, whereas the VBO and CBO decrease. The decreasing rate of VBO is higher than that of CBO, which implies the Al components play a decisive role in controlling electrons at the interface. The Al-dopled GaInAsSb alloy has a direct band gap induced by $E({\Gamma})$ with a considerable distance from the E(L) and E(X), however, $E({\Gamma})$ approaches to E(L) and E(X) in the high Sb concentration (Sb > 0.7-0.8) which might affect the electron mobility and degrade the optical quality.

• Journal of the Korea Concrete Institute
• /
• v.28 no.1
• /
• pp.59-65
• /
• 2016

Commercial synthetic resins with great amount of hydrogen atoms were investigated for neutron shielding aggregates. Total three types of resins were considered in this study: high density polyethylene (HDPE), polypropylene (PP), and ultra molecular weight polyethylene (UPE). When these resins replaced 20, 40, 60 vol% of fine aggregates, mechanical properties were first evaluated including compressive and tensile strengths, and then image/microstructure analyses such as cross-section analysis, SEM, and X-ray CT were performed. The results showed that the compressive and tensile strengths decreased with the increase of replacement ratio of HDPE and PP, which was found through image analysis that it was closely related to the distribution of resins at the failure surface of test specimens. The strength reduction of UPE was quite small compared to HDPE and PP but it abruptly increased when the replacement level exceeded 60 vol%. The results of microstructure analyses indicated that the replacement level significantly affected the amount of air void so that it is critical to determine the reasonable amount of UPE to make cementitous materials for neutron shielding.

• Applied Chemistry for Engineering
• /
• v.10 no.4
• /
• pp.581-585
• /
• 1999

The surface treated hydroxypropyl methylcellulose(HPMC) which could adjust the soluble time was synthesized when 40 wt % glyoxal solution and $KH_2PO_4$ were sprayed and reacted. And also, the solution dynamic at different ratios of two adding agents were identified If the surface of HPMC was treated with only glyoxal, the dispersion characteristics at different ratios of two adding agents were identified If the surface of HPMC was treated with only glyoxal, the dispersion was observed in the neutral solution and the viscosity was increased after directly dissolved as the solution become alkali condition. But the fine-powder type of HPMC which reacted with glyoxal and $KH_2PO_4$ was dispersed regardless of pH of solution and observed that it was dissolved and its viscosity increased after elapsing some time. With increasing amount of glyoxal and $KH_2PO_4$, the soluble time was delayed. The reaction condition was about 60 min at $75{\sim}85^{\circ}C$. Especially, the removal process of organic solvent after reaction was not required due to reaction under water solution without organic during glyoxal and $KH_2PO_4$ treatment. And also, the HPMC which could adjust the soluble rate in water or organic solvent by changing the degree of substitution of HPMC was synthesized.

• Korean Journal of Soil Science and Fertilizer
• /
• v.30 no.2
• /
• pp.146-151
• /
• 1997

To get the basic information for the establishment of the optimum levels of upland soil fertility and fertilizer application, two hundred soil samples were collected from the major vegetable cultivation areas such as Chinese cabbage, reddish, garlic, onion, red pepper, watermelon and potato fields. The soil samples were analyzed for the soil chemical properties and micro elements. Soil pH, organic matter and magnesium contents were lower than the standard level for upland soil improvement, while the phosphate and potassium contents were higher than the standard levels. The organic matter and nitrogen contents were increased in the potato field soils, the available phosphate contents were increased in the red pepper field soils and the exchangeable potassium contents were increased in reddish and red pepper field soils, to compared with the past deta. The contents of micro elements were ranged in 14~282 for Fe, 13~98 for Mn, 0.5~2.8 for Cu and 0.6~5.0 mg/kg for Zn respectively, and they were in order of Fe>Mn>Zn>Cu.

• Journal of the Korean Wood Science and Technology
• /
• v.39 no.6
• /
• pp.469-480
• /
• 2011

In this study, to determine the ligninase activity related to the PCBs degradation of Ceriporia sp. ZLY-2010, the protein contents and manganese peroxidase (MnP) and laccase activities during cultivation on shallow stationary culture (SSC) medium were observed. 4 PCB congeners were selected depending on the number of chlorine substituted on biphenyl. Furthermore, to examine the effects of cytochrome P450 monooxygenase, the inhibition of cytochrome P450 monooxygenase was evaluated by measuring the biodegradation rate when inhibitor such as 1-aminobenzotriazole was added. The extracellular protein contents were affected by PCB congeners in culture media. The total protein in the culture medium showed the biggest differences between the samples containing 2,2',4,4',5,5'-hexachlorobiphenyl and the control. On the other hand, MnP and laccase activity showed dominant increases within samples containing 4,4'-dichlorobiphenyl and 2,3',4',5-tetrachlorobiphenyl. Cytochrome P450 monooxygenase was inhibited by adding inhibitor, 1-aminobenzotriazole in low concentration. Only 2.73% of 2,3',4',5-tetrachlorobiphenyl was degraed on day 1, and biodegradation of 2,2',4,4',5,5'-hexachlorobiphenyl was inhibited as well, showing about 20% of biodegradation rate.

• Proceedings of the Korea Information Processing Society Conference
• /
• 2001.04b
• /
• pp.731-734
• /
• 2001

우편물을 집배원이 배달하는 순서로 자동구분 처리하기 위한 요소기술 줌에서 4-state 바코드 시스템이 개발되고 있으며 우편번호, 배달순서코드, 고객정보 등이 적용될 예정이다. 기존의 고객 바코드 판독 시스템은 우편물상의 바코드 심볼로지가 존재하는 판독대상 영역의 기울기가 ${\pm}4.47^{\circ}$ 이하이고, 심볼의 훼손과 잡영이 없을 경우에 $79{\sim}100msec(35,000{\sim}45,000$통/시간)의 속도로 자동 구분 정보가 판독된다. 본 논문에서는 판독범위 및 판독성능을 개선을 위하여 CCD(Charge Coupled Device) 센서로부터 획득된 이미지상에서 존재하는 심볼로지 정보의 고속판독 방법을 제시한 것이다. 이 판독방법은 그레이(gray) 이미지 바탕면의 경계값(threshold) 기울기 분포를 기준으로 2개의 경계값을 설정하여 판독대상 정보를 획득하였다. 또한, 4-state 바코드 심볼로지의 존재 가능성 영역만을 탐색하고, 판독대상 영역에서 트래커(tracker)를 탐색하여 심볼로지의 기울기값, 심볼로지 경계값, 심볼위치 좌표값을 생성한 후 심볼값이 판독한 것이다. 판독시험 결과는 판독대상 영역의 심볼로지가 ${\pm}45^{\circ}$ 기울어지고, 잡영이 존재할 경우에도 $30{\sim}60msec(58,000{\sim}l16,000$통/시간) 이내에 판독되었다. 우편물 자동구분용 바코드 판독기로써 적용될 경우에 판독속도가 평균 57.25% 이상 개선되고, 판독범위의 확장으로 0.2%의 기계적인 오류(이송과정예서의 Jam 발생 비율)를 제외할 경우에 거의 99.8% 우편물을 판독하여 자동구분 처리할 수 있게 될 것으로 기대된다.onebook 엑세스 모들(Server Phonebook Access Module)로 구성되어 있다.외 보다 높았다(I/O ratio 2.5). BTEX의 상대적 함량도 실내가 실외보다 높아 실내에도 발생원이 있음을 암시하고 있다. 자료 분석결과 유치원 실내의 벤젠은 실외로부터 유입되고 있었고, 톨루엔, 에틸벤젠, 크실렌은 실외뿐 아니라 실내에서도 발생하고 있었다. 정량한 8개 화합물 각각과 총 휘발성 유기화합물의 스피어만 상관계수는 벤젠을 제외하고는 모두 유의하였다. 이중 톨루엔과 크실렌은 총 휘발성 유기화합물과 좋은 상관성 (톨루엔 0.76, 크실렌, 0.87)을 나타내었다. 이 연구는 톨루엔과 크실렌이 총 휘발성 유기화합물의 좋은 지표를 사용될 있고, 톨루엔, 에틸벤젠, 크실렌 등 많은 휘발성 유기화합물의 발생원은 실외뿐 아니라 실내에도 있음을 나타내고 있다.>10)의 $[^{18}F]F_2$를 얻었다. 결론: $^{18}O(p,n)^{18}F$ 핵반응을 이용하여 친전자성 방사성동위원소 $[^{18}F]F_2$를 생산하였다. 표적 챔버는 알루미늄으로 제작하였으며 본 연구에서 연구된 $[^{18}F]F_2$가스는 친핵성 치환반응으로 방사성동위원소를 도입하기 어려운 다양한 방사성의 약품개발에 유용하게 이용될 수 있을 것이다.었으나 움직임 보정 후 영상을 이용하여 비교한 경우, 결합능 변화가 선조체 영역에서 국한되어 나타나며 그 유의성이 움직임 보정 전에 비하여 낮음을 알 수 있었다. 결론: 뇌활성화 과제 수행시에 동반되는 피험자의 머리 움직임에 의하여 도파민 유리가 과대평가되었으며 이는 이 연구에서 제안한 영상정합을 이용한 움직임 보정기법에 의해서 개선되었다. 답이 없는 문제, 문제 만