• 한국환경과학회지
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• 제23권5호
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• pp.819-827
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• 2014

This study analyzes the chemical composition of metallic elements and water-soluble ions in $PM_{10}$ and $PM_{2.5}$. $PM_{10}$ and $PM_{2.5}$ concentrations in Busan during 2010-2012 were $97.2{\pm}67.5$ and $67.5{\pm}32.8{\mu}g/m^3$, respectively, and the mean $PM_{2.5}/PM_{10}$ concentration ratio was 0.73. The contribution rate of water-soluble ions to $PM_{10}$ ranged from 29.0% to 58.6%(a mean of 38.6%) and that to $PM_{2.5}$ ranged from 33.9% to 58.4%(a mean of 43.1%). The contribution rate of sea salt to $PM_{10}$ was 13.9% for 2011 and 9.7% for 2012, while that to $PM_{2.5}$ was 17.4% for 2011 and 10.1% for 2012. $PM_{10}$ concentration during Asian dust events was $334.3{\mu}g/m^3$ and $113.3{\mu}g/m^3$ during non-Asian dust events, and the $PM_{10}$ concentration ratio of Asian Dust/Non Asian dust was 2.95. On the other hand, the $PM_{2.5}$ concentration in Asian dust was $157.4{\mu}g/m^3$ and $83.2{\mu}g/m^3$ in Non Asian dust, and the $PM_{2.5}$ concentration ratio of Asian Dust/Non Asian dust was 1.89, which was lower than that of $PM_{10}$.

• 아시안잔디학회지
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• 제5권1호
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• pp.47-53
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• 1991

A laboratory experiment was conducted in order to learn the effect of a number of organic matters on the ammonification and nitrification of urea, and the reaction of soil, applied to a loamy upland soil poor in orgnic matter(<1.5%, without plants 1.The ammonification of urea was most pronounced in one week period immediatly after fertilizer and water treated, after which a rapid decrease of it was followed showing no accumulation at the end of 3rd week. Owing to the accumlation of ammonium, pHs of treated soils were read 7.0 to 7.3 from 6.8~6.9. 2.Nitrification was also progressed rapidly in the first one week period so that the accumulation of NO$_3$-N surpassed that of ammonia during this period. After the 1st week the accumulation of N0$_3$-N was continuously increased showing the maximum at the end of 4 weeks following a sharp decrease at the end of 5th weeks. The accumulation of NO$_3$-N dropped soil pH from 6.8-7.0 to 6. 0-6.2,but the decrease of NO-N at the end of 5th weeks brought up soil pH to 6.4-6.6. again. 3.Amino acid fermentation byproduct rich in salt, paticularly chloride, slowed down the ammonification and nitrification of urea. 4.The application of organic matter diminished the acidifying effect of chemical fertilizers. The diminishing effect of soluble humic acid and amion acid fermentation byproduct showed greater than that of solid organic matter in this experiment, which might be own to the application of a rather small amount of water soluble organic matters. Rice straw powder among solid organic matters appeared to be the least in the diminishing effect above. It may be reasoned that these soluble organic matters decomposes rapidly so as to affect Soil pH, but solid organic matters, particularly the rice straw powder, form acidic humus.

• 폴리머
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• 제31권6호
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• pp.555-561
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• 2007

다양한 분자량을 가진 저분자량 수용성 키토산을 얻기 위해 젖산염이 결합되어 있는 키토산 올리고당을 한외여과막 장치를 이용하여 분리하였고, 새로운 염 제거법으로 유리 아민기를 가진 LMWSC를 제조하였다. 젖산염이 제거된 LMWSC의 특성과 탈아세틸화도가 적외선 분광기(Infrared spectroscopy, IR) 및 핵자기공명장치($^1H-Nuclear$ Magnetic Resonance, $^1H-NMR$)에 의해 확인되었다. 분자량을 나타내는 다분산지수(PDI)는 $1.278{\sim}1.499$로 비교적 좁은 분자량분포를 나타내었다. 유전자 전달체로서의 가능성을 확인하기 위하여, 성공적으로 분자량에 따라 분리된 키토산 올리고당과 염이 제거된 LMWSC의 유전자 전이효율이 293T cell을 이용하여 확인하였다. 또한 유전자 전이효율을 향상시키기 위해 제조된 LMWSC 유도체가 Balb/C mice를 이용하여 평가되었다.

• Elastomers and Composites
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• 제51권3호
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• pp.195-205
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• 2016

A series of aromatic poly(hydroxyamide)s (PHAs) containing varying oligo(oxyethylene) substituents and 1,3-phenylene imide ring unit in the main chain were synthesized by the direct polycondensation reaction. The inherent viscosities of the PHAs exhibited in the range of 0.89~1.12 dL/g in DMAc or DMAc/LiCl solution. The PH-2~5 copolymers were easily soluble in strong aprotic solvents: DMAc, NMP, DMSO etc. and the PH-5 copolymer was soluble in less polar solvents such as m-creasol and pyridine with LiCl salt on heating. However, all PBOs were quite insoluble in other solvents, but only partially soluble in sulfuric acid. All copolymers (PH-2~5) could afford the flexible and tough films by solution casting. We identified that the PHAs were converted to the PBOs by the thermal cyclization reaction in the range of $200{\sim}380^{\circ}C$. The 10% weight loss temperatures and char yields of the PBOs were recorded in the range of $382{\sim}647^{\circ}C$ and 38.7~73.1% values at $900^{\circ}C$. The tensile strength and initial modulus of the PH-5 in the copolmers showed the highest values of 2.46 GPa and 49.55 MPa, respectively. The LOI values of the PHAs were in the range 26.6~29.0%, and increased with increasing 1,3-phenylene imide ring unit.

• 한국대기환경학회지
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• 제22권5호
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• pp.627-641
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• 2006

Atmospheric $PM_{2.5}$ and $PM_{10}$ were measured to investigate their levels and water-soluble ions(${SO_4}^{2-},\;{NO_3}^-,\;{NO_2}^-,\;Cl^-,\;{NH_4}^+,\;Na^+,\;Ca^{2+},\;Mg^{2+},\;and\;K^+$) in Daegu between February 17 and April 18, 2006. Four Asian dust episodes during the period were examined for the influence of Asian dust on the particulate properties. Daily $PM_{2.5}\;and\;PM_{2.5-10}$ concentrations ranged between $10.83{\sim}136.76{\mu}g/m^3$ with a mean of $38.43{\mu}g/m^3$ and $16.13{\sim}409.13{\mu}g/m^3$ with a mean of $79.98{\mu}g/m^3$, respectively. For all measured ions the mean fractions of $PM_{2.5}\;and\;PM_{2.5-10}$ were 51.8% and 28.9% being lowered to 30.7% and 9.4%, respectively, during the dust episodes. Secondary ions (i.e., non-sea salt ${SO_4}^{2-},\;{NO_3}^-,\;and\;{NH_4}^+$) contributed 44.3% and 14.8% to $PM_{2.5}\;and\;PM_{2.5-10}$, respectively, with a decreased contribution during the episodes. The average equivalent ratio of ${NH_4}^+$ to the sum of ${SO_4}^{2-}\;and\;{NO_3}^-$ was 0.99 and 0.89 for $PM_{2.5}\;and\;PM_{2.5-10}$, respectively, indicating high source strength of $NH_3$ and its dominance in the neutralization of the acidic ions. Correlations and charge balance between ions suggest that neutralization of the acidic ions results in substantial depletions of carbonate both in $PM_{2.5}\;and\;PM_{2.5-10}$ and chloride only in $PM_{2.5}$.

• 한국토양비료학회지
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• 제49권3호
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• pp.265-270
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• 2016

Accumulated Phosphate can be released by ligand exchange reaction of organic acids. The objective of this study was to evaluate effects of the organic acids on the availability of phosphate and the growth of crop in phosphate and salts accumulated soil. Soil samples were collected from farmer's plastic film house. Available phosphate and electrical conductivity of soil were $3,005mg\;kg^{-1}$ and $16.63mg\;kg^{-1}$ which were 6 and 8 times higher than the optimum range of soil for crop growth, respectively. Corns were cultivated in pots for 2 months. Treatments were no treatment (control), phosphate fertilizer (P), citric acid (CA) 1, 5, 10 mM, and oxalic acid (OA) 1, 5, 10 mM. Water soluble phosphorus, available phosphate, corn growth and uptake were determined after cultivation. Results showed that organic acids increased water soluble phosphorus and available phosphate. For the level of 10 mM, the order of effectiveness of organic acids for water soluble P was citric acid (44%) > oxalic acid (32%). Height and dry weight of corns were increased significantly by the treatment of citric acid 1 and 5 mM. Also, corn absorbed more phosphorus, nitrogen, potassium, calcium and magnesium in the treatment of citric acid 1 mM than these of other treatments. Even though phosphate availability of soil was enhanced by addition of citric acid 10 mM, the growth of corns decreased because high concentration of citric acid caused salt damage by increasement of electrical conductivity. Thus, the citric acid of 1 mM has the potential to improve the availability of phosphate and the healthy growth of corns.

• 한국식생활문화학회지
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• 제23권2호
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• pp.235-242
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• 2008

In this study, the physicochemical and microbiological properties of market-available skate (Raja kenojei) kimchi were evaluated in comparison to long-term fermented Baechu kimchi. The comparative results for the skate (Raja kenojei) and Baechu kimchi products are as follows: salt concentrations = 3.40% and 3.95%, respectively; pH and acidity values = 4.01 and 3.90, and 0.65% and 0.82%, respectively; redox potential Eh values = 119.82 mV and 123.08 mV respectively; reducing sugars levels = 15.51 mg% and 13.23mg%, respectively; ascorbic acid levels = 24.21mg% and 22.18mg%, respectively; color L-values = 46.86 and 44.54, a-values = 15.46 and 12.28, and b-values = 29.94 and 28.36, respectively; hardness properties = 11.36 kgf and 10.23 kgf, respectively; hot water soluble pectin (HWSP) contents and sodium hexametaphosphate soluble pectin (NaSP) contents = 15.23% and 17.35%, and 32.51% and 29.64%, respectively; hydrochloric acid soluble pectin (HClSP) contents = 55.1% and 53.2%, respectively; total viable cell counts = $4.78{\times}10^8$ and $1.35{\times}10^8$, respectively; lactic acid bacteria counts = $5.18{\times}10^5$ and $1.32{\times}10^5$, respectively; and yeast levels = $8.52{\times}10^5$ and $5.23{\times}10^5$, respectively.

• 한국식생활문화학회지
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• 제16권2호
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• pp.118-127
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• 2001

The method of the squid safe made in Kyungsando was examined, and fermentation precess was established. The chemical composition and functional effects of the squid sikhe were examined. In the sensory evaluation, the squid sikhe made from Gampo accepted to be best for traditional Kyungsangdo squid sikhe and it is called standard sikhe. The Gampo sguid sikhe showed higher values in total sugar, free reducing sugar and nitrogen compound analysis compared to the orthers. The sugar of standard sikhe consisted of four kinds including glucose. The contents of free amino acid was increased in the order of glutamic acid, alanine, and methionine. The composition of amino acid in water or salt soluble protein of squid sikhe contained 17 kinds, and the contents was increased in order of glut amine acid, aspartic acid, and proline.

• 한국응용과학기술학회지
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• 제17권3호
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• pp.188-191
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• 2000

A new class of deep UV Photoresist based on the principles of chemical amplification was developed. This photoresist consists of three basic elements: a copolymer, blocked tetrabromobisphenol-A as a dissolution inhibitor and a photosensitive onium salt as a photoacid generator. On irradiation followed by a post exposure bake, tert-butoxycarbonyloxy phenyl group is converted to phenol group. Thus the initially base insoluble resin is converted under UV irradiation to a base soluble resin which may be preferentially removed by dissolution. This new photoresist display high sensitivity, 10 $mJ/cm^{2}$.

• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2000년도 추계학술발표대회 및 bio-venture fair
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• pp.707-708
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• 2000

Membrane strip 면역 크로마토그래피 방법을 이용하여 정량분석을 수행하기 위해 스크린프린팅 기술에 의해 제작된 membrane 전극 상에 항체를 고정화하였고 신호발생물질로써 전도성고분자인 polyaniline이 결합된 colloidal gold를 사용하였다. 이때 사용이 적합한 전도성 고분자는 수용액에 대해 용해도가 높아야 하고 또한 면역반응 최적조건인 중성 pH에서 전기전도도를 유지할 수 있어야 한다. 이를 위해 기존의 polyaniline을 $LiPF_6$로 doping 하거나 새로운 수용성 고분자인 LEB-SPAN을 사용하여 전기전도도 측정용 면역 gold를 합성하였다.