• 대한치과보철학회지
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• 제29권1호
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• pp.139-165
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• 1991

The properties of a investment material can be described by the consistency at the slurry state, the setting time, the compressive strength and the thermal expansion during the casting. In this study the effect of the production parameters which are included the ratio of quartz and cristobalite, the content of binder, the water powder ratio and the content and concentration of additives on the properties of the gypsum-bonded investments has been investigated with help of the consistency test, the vicat needle test, the compressive strength test, the thermal expansion test, x-ray diffraction and DTA thermal differential test. The experimental results showed that the constitution of a investment with W/P ratio of 0.34, 30% of gypsum, 0.8% aluminium sulfate, 2% magnesium sulfate, 0.6% sodium phosphate was adapted for the properties of the KDA Spec. No. 13 type I investment. The important experimental results are summarized as follows. 1. The consistency of the investment decreased with increasing amount of aluminium sulfate and decreasing amount of sodium phosphate. An addition of magnesium sulfate up to 2% an increase of the consistency was shown. But 3% magnesium sulfate in investment showed a decrease of consistency. The consistency did not vary significantly with a variation of the content of gypsum and cristobalite and the W/P ratio. 2. Aluminium sulfata and the magnesium sulfate promoted the hardening and the aluminium phoshpate delayed the hardening. The setting time increased with amount of gypsum. The effect of the matrix on the setting time was insignificant. With the W/P ratio of 0.34 the setting time was 14 min. 3. The compressive strength decreased with the amount of aluminium sulfate up to 0.25% and increased with the amount of aluminium sulfate greater than 3%. The compressive strength decreased as decreasing the amount of magnesium sulfate and gypsum and as increasing the W/P ratio. The effect fo the refractory on the compressive strength was also not significant. With the W/P ratio of 0.34 the compressive strength was $34Kg/mm^2$. 4. The 1st thermal expansion was found at the temperature near $250^{\circ}C$ and the steady state or the contraction stage was found at the temperature between $250^{\circ}C$ and $500^{\circ}C$. After this stage the 2nd thermal expansion took place at the temperature near $500^{\circ}C$. The amount of thermal expansion increased with decreasing the content of magnesium sulfate, aluminium sulfate and gypsum and the W/P ratio. And the amount of thermal expansion increased as the content of sodium phosphate ad cristobalite. With the W/P ratio of 0.34 the amount of total expansion was 1.2%.

• 한국자원식물학회지
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• 제14권3호
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• pp.251-258
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• 2001

한국 자생 매발톱꽃속 종자 식물유전자원의 장기저장을 위해 건조 전처리에 의해 종자 수분함수율을 저하시킨 후 액체질소(-196$^{\circ}C$) 중에서 생존 가능성 및 보존에 관해 시험하였다. 종자 수분함수율은 10분~2시간에 걸친 다양한 건조조건에 의해 9.7~3.2%로 비례적으로 감소하였다. 건조 전처리한 매발톱꽃속 종자를 액체질소 내에 6개월간 저장하여 38$\pm$5$^{\circ}C$ 온수에 해동시켜 발아율 및 발아세, 평균발아기간을 조사하였다. 건조 무처리 한 수분 함수율10.9% 조건의 매발톱꽃 종자는 초저온 보존 후, 발아율이 52.5%로 나타났으나 60분간 건조 전처리 하여 수분 함수율이 6.0%로 조정된 종자의 경우는 84.7%가 발아하였다. 또한 발아세에 있어서도 수분 함수율이 5% 내외로 적절히 건조 전처리 한 매발톱 꽃속 종자는 초저온 보존 이후에 60%이상의 높은 발아세와 11~13일의 고른 평균 발아기간이 나타났다. 본 시험의 결과, 적절한 처리시간에 의해 건조 전처리한 자생 매발톱꽃속 종자를 초저온 조건의 액체질소에 장기 저장하여도 대조구에 비해 발아율은 약 0.5%가 저하하였으나 발아세, 평균발아율에는 큰차이가 나타나지 않았다. 또한 발아묘의 기형적인 형태적 변화도 관찰되지 않았다. 그러므로 단명성인자생 매발톱꽃속 종자의 초저온 보존은 식물 유전자원을 유전적으로 안전하고 경제적으로 저장할 수 있는 방법으로 사료된다.

• 한국자원식물학회지
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• 제11권1호
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• pp.70-79
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• 1998

This study was conducted to understand the effects of weather and tapping date on yield and quality of lactree(Rhus verniciflua) sap yield showed a significant positive correlation with the minimum temperature of one day before sap collection at 1% level and with theminimum humidity of theday of sap collection at 5% level. However, the differences between the maximum and the minimum temperatures and humidities of the day of sap collection were negatively correlated with the sap yield at 5% level. Multiple regression analysis indicated that the minimum temperature of one day bofore sap collection and the minumum humidity of the day sap collection were important factors for increasing sap yield. The high sap yield of lactree by Japanese tapping method was recorded during mid-July and early August. Seasonal variation in lactree sap constituents was observed. The sap collected on 15th of August contained the highest urushiol content (68.3%) and the lowest water content resulting in high quality of lactree sap. By reversed-phase HPLC analysis, fove urushiol components were separated from each other depending on the number of doulbe bonds in the side-chain , and seaxonal variation of urushiol composition was noticed. The 3-C15 triene content fo the sap collected on 5th of July was the highest(77.56%) indicating the major component of urushiol which affects lactree sap quality.

• 한국작물학회지
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• 제42권1호
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• pp.22-32
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• 1997

국내 자생종인 광릉쥐오줌풀의 생육ㆍ수량 및 정유 함량에 미치는 온도 광도 및 토양 수분의 영향을 검토하여 쥐오줌풀의 재배법을 구명하고자 온도를 10, 15, 20, 25, 3$0^{\circ}C$ 등 5수준으로, 광도는 1,000, 2,500, 5,000, 20,000, 30,000, 40,000, 50,000, 60,000lux 등 8수준으로 처리하였고, 차광은 무차광 25% 차광ㆍ50% 차광구를 설치하였으며, 토양 수분 함량은 최대 용수량의 30, 45, 55, 70,.80, 90%등 6수준으로 각각 처리하여 시험한 결과를 요약하면 다음과 같다. 1. 온도와 쥐오줌풀 잎의 광합성간에는 고도로 유의한 2차 곡선회귀가 인정되었으며, 이 회귀식에 의해 산출한 쥐오줌풀의 최대 광합성을 위한 온도는 17.7$^{\circ}C$이었다. 2. 온도와 쥐오줌풀의 엽장ㆍ엽폭ㆍ엽병장 및 근 중간에는 각각 고도로 유의 한 2차 곡선회귀가 인정되었으며, 이 회귀식에 의해 산출한 뿌리 생장의 최적 온도는 약 20.3$^{\circ}C$였다. 3. 정유 및 extract함량은 온도 조건이 15~2$0^{\circ}C$에서 가장 높았다. 4. 광도와 쥐오준풀 잎의 광합성간에는 고도로 유의한 2차 곡선회귀가 인정되었으며, 이 회귀식에 의해 산출한 쥐오줌풀의 최대 광합성을 위한 광도는 40,000lux였다. 5. 쥐오줌풀의 정유 함량은 재배지역에 따른 차광의 유무와는 관계가 없었고, 정유 성분의 조성 비율은 재배지역 및 차광에 따라 영향을 받았다. 6. 토양수분 함량이 많을수록 엽병장ㆍ엽장ㆍ엽폭ㆍ근장이 길어지고, 뿌리 수량이 많아지는 경향을 보였는데, 토양 수분 함량이 최대 용수량의 80~90%일 때 쥐오줌풀의 생육이 양호하였고, 근중이 가장 많았다. 7. 쥐오줌풀 뿌리의 정유 및 extract함량은 토양 수분 함량이 90%에서 가장 많았고, 토양 수분함량이 낮을수록 감소하였다.

• Journal of Ecology and Environment
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• 제30권2호
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• pp.187-193
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• 2007

Higher plants can be categorized as C3, C4 or CAM according to their photosynthetic pathways, and some succulent plants are known to shift their patterns of photosynthesis from C3 to CAM in response to environmental stresses such as salt treatment or water deficiency. To investigate fundamental photosynthetic patterns and the induction of pattern shifts (C3, CAM, C3-CAM etc.) as a result of environmental stresses, we measured the water content, diurnal changes in pH, net $CO_2$ exchange, transpiration rate, total ionic contents, and osmolality of Kalancoe daigremontiana, Sedum kamschaticum and Sedum sarmentosum which belong to Crassulaceae known as representative CAM plant, after 10 days of drought treatment. S. kamschaticum and S. sarmentosum did not show a significant difference in diurnal pH variation in the treatment and control conditions. However, the pH of drought-treated Kalancoe was low at night and high in the daytime, with a pH value between 4 and 5. Typical CAM plants display a net $CO_2$ exchange that increases at night and decreases in the daytime. Kalancoe displayed the predicted pattern. However, S. kamschaticum and S. sarmentosum showed a photosynthetic pattern more typical of C3 plants, and did not show changes in photosynthetic pattern under drought stress. Kalancoe also showed a transpiration rate typical for CAM pho-tosynthesis, whereas the transpiration rates of S. kamschaticum and S. sarmentosum were in the typical range for C3 photosynthesis. Kalancoe had high total ionic contents during the night, which decreased somewhat during the daytime, whereas S. kamschaticum and S. sarmentosum displayed the opposite pattern. This result is similar to the diurnal patterns of changes in pH in the three plant species, which suggests a relationship between pH and ionic contents. S. sarmentosum showed lower osmolality under drought stress than in the control condition, whereas the osmolality of Kalancoe and S. kamschaticum did not differ between conditions. S. sarmentosum may have maintained internal water content by lowering its osmolality and raising its total ionic contents. In conclusion, Kalancoe displayed the characteristic responses of a typical CAM plant, whereas S. kamschaticum and S. sarmentosum displayed aspects of the C3 photosynthetic pattern under drought conditions. These results suggest that S. kamschaticum and S. sarmentosum (Crassulacea) in Korea overcome drought stress by increasing solute and ionic contents internally rather than changing their photosynthetic pattern from C3 to CAM under drought stress.

• 생명과학회지
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• 제22권1호
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• pp.80-86
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• 2012

우리 나라 전통술인 탁주의 주질 개선을 위한 목적으로 천연성과 기능성을 가진 벌꿀을 사용하였고 저장기간의 연장을 위하여 술액의 침전물 양을 조절할 목적으로 본 연구를 진행하였다. 발효방식은 주모발효 후 3단담금 방식으로 하였고, 입국균은 Aspergillus awamori var. kawachi, 원료는 100% 백미, 알코올 발효 효모는 Saccharomyces cerevisiae를 사용하였다. 제성액의 고형분과 술액을 분리하여 벌꿀을 최종농도 5%(w/v) 첨가하여 5, 10, $15^{\circ}C$에서 23일간 숙성하였을 때 온도에 따른 유의한 차이는 보이지 않았으며 숙성기간 동안 알코올이 미소하게 감소했을 뿐 pH, 산도 및 총당량은 거의 일정하였다. 이와 같이 특징적인 술액의 차이는 없었지만 벌꿀숙성으로 제조한 탁주가 벌꿀 첨가 직후의 미숙성 탁주와 비교할 때 우수한 관능 테스트 결과를 보여주었다. 추가적으로 냉동 보관한 고형분을 100%, 50% 및 25% 비율로 벌꿀첨가 숙성된 술액과 혼합한 후 물을 보충하여 알코올 8%의 탁주를 제조하고 37일간 $10^{\circ}C$에서 날짜 별로 분석하였다. pH는 모든 탁주에서 4.5~4.8 사이를 큰 차이 없이 유지하였으며 고형분 첨가량이 많을수록 효모 세포수, 산도 및 알코올 함량은 상대적으로 증가하였고 총당량은 감소함을 보여 주었다. 즉 고형분의 양이 소량일수록 탁주의 주질이 안정하였다. 결론적으로 발효 후 고액 분리하여 상층액에 벌꿀을 첨가함으로써 저온 숙성기간 동안 주질의 큰 변화를 주지 않고 관능적으로 우수한 술액을 만들 수 있었으며, 고형분의 재혼합 비율을 조절할 경우 저장기간이 증대된 탁주를 제조할 수 있을 것이다.

• 천문학회보
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• 제42권2호
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• pp.55.5-56
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• 2017

Galaxy dynamics probes weak gravity at accelerations below the de Sitter scale of acceleration adS = cH, where c is the velocity of light and H is the Hubble parameter. Low and high redshift galaxies hereby offer a novel probe of weak gravity in an evolving cosmology, satisfying H(z) = H0(1 + A(6z + 12z^2 +12z^3+ 6z^4+ (6/5)z^5)/(1 + z) with baryonic matter content A sans tension to H0 in surveys of the Local Universe. Galaxy rotation curves show anomalous galaxy dynamics in weak gravity aN < adS across a transition radius r beyond about 5 kpc for galaxy mass of 1e11 solar mass. where aN is the Newtonian acceleration based on baryonic matter content. We identify this behavior with a holographic origin of inertia from entanglement entropy, that introduces a C0 onset across aN=adS with asymptotic behavior described by a Milgrom parameter satisfying a0=omega/(2pi), where omega=sqrt(1-q)H is a fundamental eigenfrequency of the cosmological horizon. Extending an earlier confrontation with data covering 0.003 < aN/adS < 1 at redshift z about zero in Lellie et al. (2016), the modest anomalous behavior in the Genzel et al. sample at redshifts 0.854 < z <2.282 is found to be mostly due to clustering 0.36 < aN/adS < 1 close to the C0 onset to weak gravity and an increase of up to 65% in a0.

• Journal of Microbiology and Biotechnology
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• 제11권2호
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• pp.333-336
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• 2001

An isolated phbC gene from Alcaligenes latus was reintroduced into the parent A. latus through the transformation process, and the effect of the amplified phbC gene on the biosynthesis of P(3-hydroxybutyrate-3-hydroxyvalerate) [P(3HB-3HV)] and P(3-hydroxybutyrate-4-hydroxybutyrate) [P(3HB-4HB)] in the transformant A. latus was investigated. The biosynthesis rate and content of the above copolymers increased up to 1.3-fold after enforcing its own phbC gene, and the molar fractions of 3HV and 4HB in P(3HB-3HV) and P(3HB-4HB) also changed remarkably from 35.0 to 48.0% and from 34.0 to 56.0%, respectively, showing a critical role of PHB synthase which catalyzes the polymerizing reactions between eiher 3HV or 4HB from precursor compounds and 3HB.

• Ecology and Resilient Infrastructure
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• 제2권2호
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• pp.177-184
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• 2015

This study assessed the performance of activated carbon (AC) amendment to treat polycyclic aromatic hydrocarbons (PAHs) including both parent- and alkylated-moieties in sediment impacted by diesel. A field-collected, diesel-impacted sediment with a NAPL content of 1% was used for the study. No. 2 diesel fuel is weathered by heating at $70^{\circ}C$ for 4 days to obtain a weathered diesel sample having C3-naphthalenes to C2-phenanthrenes/anthracenes (N2/P3) ratio similar to the original sediment. The sediment samples spiked with the weathered diesel to obtain non-aqueous phase liquid (NAPL) contents of 1, 5 and 10% were contacted with AC with a dose of 5% as sediment dry weight for 1 month. By the AC-sediment contact, the freely-dissolved equilibrium concentrations were substantially reduced. Even for sediment with 10% NAPL content, the reductions in the freely-dissolved concentrations were 92% and 75% for total parent-and alkylated-PAHs, respectively. The effect of NAPL contents on the performance of AC was negligible for parent-PAHs, while for alkylated-PAHs, a slightly reduced AC performance was observed. The results suggest that the AC amendment can be an effective option for the treatment of petroleum-impacted sediment with relatively high NAPL contents.

• 한국환경복원기술학회지
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• 제12권2호
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• pp.1-9
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• 2009

Due to the increase of carbon dioxide in the atmosphere and global warming, the importance of forest ecosystems, as a place of carbon accumulation and emission, has received a great amount of recognition lately. This study was performed to help understand and provide the current status of carbon cycle in the pinus densiflora stand, Korea. The samples were collected from average 35-years-old Pinus densifiora rands in Gongju, Youngdong, Chungsan, Muju, Mupung, and Jangsu regions. Total thirty aboveground sample trees were cut, and ten roots were sampled, and soil samples were collected. Average carbon concentrations in foliage, branch, stem bark, stem wood, and root were 55.7%, 56.0%, 56.0%, 57.3%, and 56.5%, respectively. Carbon content was estimated by the model $Wt=aD^b$ where Wt is oven-dry weight in kg and D is DBH in cm. Total carbon content (aboveground and root) was 42.39tonC/ha in the Pinus densiflora stand. The proportion of each tree component to total carbon content was high in order of stemwood, root, branch, stem bark, and foliage. Total net primary production (aboveground and root) was estimated at 6.51tonC/ha/yr in Pinus densiflora stand. The proportion of each tree component to total net primary carbon content was high in order of sternwood, root, branch, foliage and stembark. Soil carbon contents in the study sites was 43.51tonC/ha at 0-50cm soil depth.