• 대한화학회지
• /
• 제28권1호
• /
• pp.54-61
• /
• 1984

질산 산성에서 얻은 $MoO_4^{2-}$와 $WO_4^{2-}$의 용리곡선과 Z값에 따른 텅스텐의 UV스펙트럼 변화로부터 질산 농도 변화에 따른 이들 이온들의 화학종과 평형관계를 연구하였다. 물리브덴은 0.05M 이상의 질산 용액에서$Mo_8O_{26}^{4-} + 20H^+$ ${\rightleftharpoons}$ $8MoO_2^{2+}$ + $10H_2O$반응에 의해 $MoO_2^{2+}$이온을 생성하여 이 이온이$MoO_2(NO_3)_2$와 같은 질산착물을 생성하는 것으로 보인다. 질산 산성에서 텅스텐산의 용리현상은 과염소산에서와 유사하다. 그래서 과염소산에서 존재하는 텅스텐의 평형관계가 질산 산성에서도 존재한다고 생각된다. 이들 텅스텐의 용리현상 결과를 Z값에 따른 텅스텐의 UV스펙트럼 변화와 비교하였다.

• 한국산림과학회지
• /
• 제83권4호
• /
• pp.540-544
• /
• 1994

중부 지방에서 옥내의 목재 사용 4장소별로 기후치평형함수율은 온도와 상대습도를 근거하여 계산하고 실측평형함수율은 더그러스 퍼와 상수리나무 등 7수종의 기건 시험편을 1년간 공시하여 측정하였다. 조사된 각 장소의 연간 평균 온도과 상대습도는 아파트 안방이 $23.3^{\circ}C$와 54.9%, 아파트 거실은 $22.4^{\circ}C$와 59.5%, 사무실은 $20.1^{\circ}C$와 57.0%, 단독주택의 거실은 $19.4^{\circ}C$와 64.0%이었다. 년간 평균 기후치평형함수율과 실측평형함수율은 아파트 안방은 각각 10.2%와 9.7%, 아파트 거실은 각각 11.1%와 10.2%, 사무실은 각각 10.7%와 10.4% 그리고 단독주택의 거실은 각각 12.1%와 12.5%이었다. 카사이의 실측평형함수율은 전체 평균치보다 약간 컸었고 버즘나무와 아피통은 약간 적었다.

• Journal of the Korean Wood Science and Technology
• /
• 제34권1호
• /
• pp.40-51
• /
• 2006

수피의 탄화이용을 위한 수피탄화기술 확립과 이 수피탄화물을 흡착제, 토양개량자재, 미생물활동담체, 건강재료 등으로의 이용 가능성을 알아보기 위해 수피탄화물의 메틸렌블루흡착량, 흡습성, 원적외선 방사율, pH, 보수성 및 발열량 등의 성능을 조사하였다. 메틸렌블루흡착량이 탄화온도 $800^{\circ}C$, 탄화시간 8시간에서 낙엽송, 잣나무, 리기다소나무 수피탄화물들은 110 mg/g 이상의 값을 보이고, 모든 수피탄화물의 수소이온농도가 탄화시간 4시간의 경우 탄화온도 $400^{\circ}C$에서 pH 6.6, $600^{\circ}C$와 $800^{\circ}C$에서는 pH 9 정도를 나타내는 등, 수피탄화물은 탄화물로서의 이용이 가능하고, 탄화온도와 시간만 고려하면 충분히 이용 가능할 것으로 사료된다.

• Journal of the Korean Wood Science and Technology
• /
• 제27권3호
• /
• pp.7-16
• /
• 1999

본 연구는 밤나무와 오동나무에 대해 살리게닌 처리, 가열처리 및 무처리재의 세포조직, 평형함수율, 흡습성과 음향 성을 비교할 목적으로 수행하였는데, 이를 수종의 무처리재와 열처리재의 세포조직은 거의 동일하였지만 살리게닌 처리재의 세포벽은 무처리재의 것보다 두꺼워졌다. 평형함수율은 무처리재, 가열처리재 및 살리게닌 처리재 순으로 낮게 나타났으며, 살리게닌 흡수율(吸收率)이 클수록 평형함수율은 감소되었고 흡습곡선은 포물선적으로 증가되었다. 살리게닌 처리재의 음향성은 현저하게 개선되었으며, 그 다음 가열처리재 순으로 나타났다. 살리게닌 흡수율(吸收率)후 수준에 따른 음향성은 밤나무의 경우 흡수율(吸收率) 20%와 30%, 그리고 오동나무의 경우 흡수율(吸收率) 80% 처리재의 개량효과가 가장 컸었다.

• Ocean and Polar Research
• /
• 제39권3호
• /
• pp.221-232
• /
• 2017

The purpose of this study is to estimate the extent of fisheries resource rebuilding and other economic effects on coastal gill-net fishery as a result of the Korean vessel buy-back program using with-without analysis based on methods estimating sustainable yields for all species caught by coastal gill-net fishery. Based on the results of with-without analysis, maximum sustainable yields (MSY) of all species caught by coastal gill-net fishery have been increased by the Korean vessel buy-back program. In addition, profits per vessel of maximum economic yield (MEY) of the species have been improved by the program. Further, yields and a producer surplus per vessel under an equilibrium of open access (OA) have increased because of the program. In detail, first of all, at the MSY level, the vessel buy-back program has led to about 21% fisheries resource recovery, and at the MEY level, it has led to about a 19% resource recovery. Secondly, at the MEY level and the OA level, the producer surplus per vessel has been increased by about 24% and 22% respectively by the vessel buy-back program.

• 한국자기공명학회논문지
• /
• 제1권2호
• /
• pp.126-140
• /
• 1997

Mesoporous MCM-41 gallosilicate material was synthesized through shifting through shifting gallosilicate polymer equilibrium towards a MCM-41 phase by addition of acid. The location of Cu(II) exchanged into MCM-41 and its interaction with various adsorbate molecules were investigated by electron spin responance and electron spin echo modulation spectroscopies. It was found that in the fresh hydrated material, Cu(II) is octahedrally coordinated to six water molecules. This species is located in a cylindrical channel and rotates rapidly at room temperature. Evacuation at room temperature removes three of these water molecules, leaving the Cu (II) coordinated to three water molecules and anchored to oxygens in the channel wall. Dehydration at 45$0^{\circ}C$ produces one Cu (II) species located in the inner surface of a channel as evidenced by broadening of its ESR lines by oxygen. Adsorption of polar molecules such as water, methanol and ammonia on dehydrated CuNa-MCM-41 gallosilicate material causes changes in the ESR spectrum of Cu (II), indicating the complex formation with these adsorbates. Cu (II) forms a complex with six molecules of methanol as evidenced by an isotropic room temperature ESR signal and ESEM data like upon water adsorption. Cu(II) also forms a complex containing four molecules of ammonia based on resolved nitrogen superhyperfine interaction.

• Journal of Pharmaceutical Investigation
• /
• 제30권1호
• /
• pp.33-37
• /
• 2000

One of the methods to increase the solubility of a drug is to use complexation with a cyclodextrin. Due to the hydrophobic nature of the interior cavity of the cyclodextrin, it has been known that undissociated lipophilic drugs can be included within the cyclodextrin by hydrophobic interaction. Recently, inclusion of hydrophilic or dissociated form of a drug has been investigated. In this study, the synergism of pH and complexation with $hydroxypropy-{\beta}-cyclodextrin\;(HP\;{\beta}\;CD)$ to increase the solubility of two oxicam derivatives was investigated. In addition, the effect of partition coefficient of dissociated and undissociated form of the drug on the extent of complexation with HP ${\beta}$ CD was studied. The solubility was measured by equilibrium solubility method. The solubility of tenoxicam and piroxicam increased exponentially with an increase in solution pH above the pKa of the drug in the presence and absence of HP ${\beta}$ CD. The solubility of the drugs increased linearly as a function of HP ${\beta}CD$ concentration at fixed pH. Although the stability constant of ionized species is less than that of the unionized species, the concentration of the ionized drug complex is greater than that of the unionized drug complex due to higher concentration of ionized species at pH 7.3.

• Animal Systematics, Evolution and Diversity
• /
• 제33권2호
• /
• pp.136-139
• /
• 2017

The genus Iksookimia (Actinopterygii: Cypriniformes: Cobitidae) is a bottom-dwelling freshwater loaches, which are well-known as their endemism and high geographic variation. However, population genetic relationships among Iksookimia spp. have remained unclear due to a shortage of genetic markers that can be applied generally in the genus. Here, we developed high-resolving microsatellite markers using I. koreensis and I. longicorpa as representatives of Iksookimia species because of their wide distribution range and phylogenetic position. Ten of polymorphic microsatellite loci were isolated from Iksookimia koreensis and were successfully cross-amplified in I. longicorpa. The mean number of observed alleles per locus was about 10.4 (range, 2-17) for I. koreensis and about 13.2 (range, 2-24) for I. longicorpa. The loci, IK03 and IK08, deviated from the Hardy-Weinberg equilibrium in I. koreensis, after applying the Bonferroni correction. The microsatellite markers obtained in the present study will be useful to evaluate population genetic structure and to establish conservation strategies for I. koreensis and related Iksookimia species.

• 한국표면공학회지
• /
• 제34권5호
• /
• pp.395-402
• /
• 2001

An induction thermal plasma system have been newly designed for advanced operation with a pulse modulated mode to control the plasma power in time domain and to create non-equilibrium effects such as fast quenching of the plasma to produce new functional materials in high rate. The system consists of MOSFET power supply with a maximum power of 50 kW with a frequency of 460 kHz, an induction plasma torch with a 10-turns coil of 80 mm diameter and 150 mm length and a vacuum chamber. The pulse modulated plasma was successfully generated at a plasma power of 30 kW and a high pressure of 100 kPa, with taking the on and off time as 10 ms, respectively. Measurements were carried out on the time-dependent spectral lines emitted from Ar species. The dynamic behavior of plasma temperature in a pulse cycle was estimated by the Boltzmann plot and the excitation temperature of Ar atom was found to be changed periodically from around 0.5 to 1.7 eV during the cycle. Two application regions of the induction thermal plasma newly generated were introduced to material processing with high rate synthesis based on non equilibrium effects, and to the finding of new arc quenching gases coming necessary for power circuit breaker, which is friendly with earth circumstance alternative to SF6 gas.

• Bulletin of the Korean Chemical Society
• /
• 제27권6호
• /
• pp.886-892
• /
• 2006

The interaction between tetraethylammonium chloride (TEACl) with ICl and tetraethylammonium iodide (TEAI) and aza-15-crown-5 (A15C5) with $I_2$ and ICl have been examined spectrophotometrically in acetonitrile solution. The results of TEACl-ICl indicate the formation of $ICl_2$ - through equilibrium reaction. In the case of TEAI-$I_2$ and A15C5-$I_2$, the equilibrium formation of $I_3$ - is confirmed. The interaction of TEAI-ICl begins with the simultaneous production of $I_2$ and IC$I_2$ - (at TEAI/ICl < 0.5) as well as continues with the simultaneous consumption of $I_2$ and formation of I$I_3$ - (at TEAI/ICl > 0.5). Similar behavior is also observed for A15C5-ICl system. However, the changes are seen at A15C5/ICl mole ratios less and more than 0.66. Several equations have been suggested for the formation of detected species. The formation constants of various reactions were evaluated from the computer fitting of the absorbance-mole ratio data. IR spectra of A15C5 and 1:1 A15C5:ICl or A15C5:$I_2$ complexes are compared and the effect of complexation on absorption bands is discussed.