• Title/Summary/Keyword: synthetic solution

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GEMS BrO Retrieval Sensitivity Test Using a Radiative Transfer Model (복사전달모델을 이용한 GEMS 일산화브로민 산출 민감도 시험)

  • Chong, Heesung;Kim, Jhoon;Jeong, Ukkyo;Park, Sang Seo;Hong, Jaemin;Ahn, Dha Hyun;Cha, Hyeji;Lee, Won-Jin;Lee, Hae-jung
    • Korean Journal of Remote Sensing
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    • v.37 no.6_1
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    • pp.1491-1506
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    • 2021
  • To estimate errors in GEMS retrievals for bromine monoxide (BrO) total vertical column densities(VCDs), we perform a sensitivity test using synthetic spectra generated by a radiative transfer model. Hourly synthetic data are produced for 00-07 UTC on the first day of every month in Jul 2013- Jun 2014. Solution errors estimated by the optimal estimation method tend to decrease with increasing air mass factors (AMFs) but increase when AMFs are larger than 5. Interference errors induced by formaldehyde (HCHO) absorption appear to be larger with smaller BrO AMFs. Total BrO retrieval errors estimated by combining solution and interference errors show an average of 26.74±30.18% for all data samples and 60.39±133.78% for those with solar zenith angles higher than 80°. Due to interfering spectral features and measurement errors not considered in thisstudy, errorsin BrO retrievals from actual GEMS measurements may have different magnitudes from our estimates. However, the variability of errors assessed in this study is still expected to appear in the actual BrO retrievals.

EFFECTS OF FLUORIDE MOUTHRINSE ON CELL ACTIVITY OF GINGIVAL FIBROBLASTS OF CHILDREN (불소양치용액이 소아 치은 섬유아세포의 세포활성에 미치는 영향에 관한 연구)

  • Lee, Dong-Hyun;Lee, Kwang-Hee
    • Journal of the korean academy of Pediatric Dentistry
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    • v.24 no.1
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    • pp.204-219
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    • 1997
  • The use of fluoride is one of the most effective methods for caries prevention. Fluoridation of public water supply has been recognized, for many years, as an effective way to reduce dental caries. The fluoride supplement has been recommended when the natural fluoride was unavailable or below the optimal range. However the mechanism of caries prevention by fluoride has not yet been clarified and it is well known that an overdose of fluoride results inacute and chronic toxicity, especially dental fluorosis. Fluoride mouthrinsing solution is widely used in dentistry due to its effectiveness in carrying anticariogenic action. Understanding the effects of fluoride mouthrinsing solution on human gingival fibroblasts will provide the safety rationale for its use during the caries preventive therapy. The purpose of this study was to evaluate the cytotoxic effect of fluoride mouthrinsing solution on the human gingival fibroblast in vitro. The human gingival fibroblasts were cultured from healthy gingiva on the extracted deciduous teeth of children. Cells were inoculated into a 24-well plate with $1{\times}10^4cells/well$ of medium at $37^{\circ}C$, 100% humidity, 5% $CO_2$ incubator for 24 hours. And the cells were counted by using the hemocytometer at each designed study. Human gingival fibroblasts were cultured in growth medium after one minute application range of 0.02%-0.2% NaF solution and 0.1% $SnF_2$ solution. The cells used in this study were between fifth to eighth passage number. The cell morphology was examined by inverted microscope and cell proliferation was measured by incorporating $[^3H]$-thymidine into DNA. DNA synthesis by human gingival fibroblasts was assessed by $[^3H]$-thymidine uptake assays while the cell activity was measured by MTT assay. Each concentrated fluoride mouthrinsing solution was estimated for its biocompatability with fibroblasts by the tissue culture technique. The results of this study were as follows : 1. It was observed that at 0.05%, 0.2% NaF mouthrinsing solution the cytoplasmic processes became globular. When 0.1% $SnF_2$ mouthrinsing solution was applied, the cytoplasmic process and cell morphology were disappeared. 2. DNA synthetic activity was reduced regardless of the concentration of the fluoride mouthrinsing solution. However, the result is statistically insignificant except 0.1% $SnF_2$ mouthrinsing solution(p<0.05). 3. Our results indicate that 0.02%, 0.05% concentrations of NaF mouthrinsing solution caused minimal cytotoxicity. But 0.2% NaF and 0.1% $SnF_2$ concentration were a significant difference between the cell activity in the experimental group and control group (p<0.05). 4. After appling 0.05% & 0.02% NaF fluoride mouthrinsing solution, cell activity was restored to the control groups level according to incubating time. The results suggest that direct exposure to fluoride solution inhibits gingival fibroblast activity. Therefore, for the most effective use of fluoride use, lowering the concentration of fluoride mouthrinsing is advisable because it maintains biocompatability and free ion in the oral fluid.

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A Study on the Hand of the Fabrics Treated with Chitosan-polyurethane Mixture Solution -Thermal Curing of Cotton, Polyester, and Nylon Fabrics- (Chitosan-polyurethane 혼합 용액으로 처리된 직물의 태 연구 - 면, 폴리에스터, 나일론 직물의 열 Curing -)

  • Kwak Jung-Ki;Jeon Dong-Won;Kim Jong-Jun
    • Journal of the Korean Society of Clothing and Textiles
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    • v.29 no.7 s.144
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    • pp.997-1007
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    • 2005
  • The textile finishing methods utilizing chitosan have been mostly focused on the applications in the improvement of the dyeing of cotton fabrics, or the improvement of hand of the cotton or wool fabrics. On the other hand, it Is difficult to find the application examples in the synthetic fiber fabrics including polyester and nylon fabrics. The aim of this study is to improve the stiffness and the poor wash fastness of the fabrics treated only with chitosan. We tried to improve the softness by employing chitosan and polyurethane mixture solution and to prevent the detachment of the chitosan from the fabric. The treatment was applied to cotton, polyester, and nylon fabrics. The change of the properties of the treated fabrics were investigated. The optimum finishing condition was sought by changing the mixture ratio of the chitosan/PU(polyurethane) solutions. The adjusted ratios of the chitosan/PU solutions were 1 : 0, 1 : 0.25, 1 : 0.5, and 1 : 2 during the mixture solution preparation. Using the KES(Kawabata Evaluation System), the physical and mechanical properties of the finished fabric specimens were analyzed, and hand values of the specimens were calculated through the use of translational formulas. According to the chemical composition of the fibers, chitosan solution or chitosan/PU mixture exhibited wide range of coating effect. Since the chitosan acid solution has high polarity, the bonding force with the cotton fibers is high. By the appropriate addition of PU in the chitosan treatment of cotton, KOSHI and HARI values of the fabric improved. The air permeability of the chitosan/PU treated cotton fabric specimen improved, resulting in the highest value at the mixture of chitosan : PU=1:0.25.

Serum or serum albumin in a vitrification solution and EGF or FGF affect in vitro viability of frozen-thawed bovine blastocysts after vitrification (동결액에 첨가된 macromolecule 및 EGF, FGF가 vitrification 법으로 동결한 소 수정란의 체외생존성에 미치는 영향)

  • Lee, Eun-song;Fukui, Yutaka
    • Korean Journal of Veterinary Research
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    • v.38 no.2
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    • pp.394-400
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    • 1998
  • Cryopreservation of embryos by vitrification is a simple method to preserve bovine embryos for subsequent embryo transfer, but embryonic viability after vitrification has been inconsistent and low compared with conventional slow freezing. The aim of the present study is to examine the effect of serum or serum albumin in a vitrification solution and epidermal growth factor(EGF) or fibroblast growth factor(FGF) on in vitro viability of bovine blastocysts frozen by vitrification. Bovine blastocysts were produced by in vitro maturation, fertilization of follicular oocytes and culture of embryos in a synthetic oviduct fluid medium(SOFM) containing BSA and 19 essential and nonessential amino acids. Blastocysts with excellent or good morphology were selected at 7 or 8 days after culture and utilized for vitrification. In experiment 1, blastocysts were vitrified in a solution containing semi-fetal calf serum(SFCS) or BSA(5 or 10mg/ml) and then their subsequent viabilities were examined by culturing thawed embryos in a SOFM containing BSA and 19 amino acids. Effect of EGF or FGF added to a SOFM containing polyvinyl alcohol(PVA) on the viability of vitrified-thawed blastocysts was investigated in experiment 2. BSA added at 5 or 10mg/ml to a vitrification solution showed significantly higher(p < 0.05) developmental rate to expanded and hatching blastocysts than SFCS, but there was no significant difference in the developmental rate to hatched blastocysts after thawing. Supplementation of a culture medium with EGF and/or FGF significantly increased(p < 0.05) embryo development to expanded blastocysts compared with control but showed no beneficial effect on the development to hatching or hatched blastocysts. Coculture of thawed embryos with granulosa cells in a TCM 199 containing 10% fetal calf serum(FCS) showed the highest developmental rate to expanded, hatching and hatched blastocysts among the groups tested. In conclusion, supplementation of a vitrification solution with BSA at 5mg/ml and culture of thawed blastocysts in a medium containing EGF and/or FGF can improve in vitro viability of bovine blastocysts frozen by vitrification.

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Forward Osmosis Membrane to Treat Effluent from Anaerobic Fluidized Bed Bioreactor for Wastewater Reuse Applications (하수재이용을 위한 혐기성 유동상 생물반응기 처리수의 정삼투 여과막의 적용)

  • Kwon, Dae-eun;Kim, Jeonghwan
    • Membrane Journal
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    • v.28 no.3
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    • pp.196-204
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    • 2018
  • The anaerobic fluidized bed bioreactor (AFBR) treating synthetic wastewater to simulate domestic sewage was operated under GAC fluidization to provide high surface area for biofilm formation. Although the AFBR achieves excellent COD removal efficiency due to biological activities, concerns are still made with nutrient such as nitrogen remaining in the effluent produced by AFBR. In this study, forward osmosis membrane was applied to treat the effluent produced by AFBR to investigate removal efficiency of total nitrogen (TN) with respect to the draw solution (DS) such as NaCl and glucose. Permeability of FO membrane increased with increasing DS concentration. About 55% of TN removal efficiency was observed with the FO membrane using 1 M of NaCl of draw solution, but almost complete TN removal efficiency was achieved with 1 M of glucose of draw solution. During 24 h of filtration, there was no permeate flux decline with the FO membrane regardless of draw solution applied.

Isoindigo Based Small Molecules for High-Performance Solution-Processed Organic Photovoltaic Devices

  • Elsawy, W.;Lee, C.L.;Cho, S.;Oh, S.H.;Moon, S.H.;Elbarbary, A.;Lee, Jae-Suk
    • Proceedings of the Korean Vacuum Society Conference
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    • 2013.08a
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    • pp.245.2-245.2
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    • 2013
  • Solution processed organic photovoltaic devices have relatively less attention compared to polymer photovoltaic devices even though they have high possibility to be developed because they have both advantages of polymer and organic, such as solution processable, no synthetic batch dependence of photovoltaic performance, high purity and high charge carrier mobility as well as relatively high efficiency (~7%). In addition, solution processed organic photovoltaic devices have an advantage of easiness to study the relationship between the molecular structure and photovoltaic performance due to its simple structure. In this work, five isoindigo based low band gap donor-acceptor-donor (D-A-D) small molecules with different electron donating strength were synthesized for investigating the relationship between the molecular structure and photovoltaic performance, especially, investigating the effects of different electron donating effect of donor group in isoindigo backbone to photovoltaic device performance. The variation of electron donating strength of donor group strongly affected the optical, thermal, electrochemical and photovoltaic device performances of isoindigo organic materials. The highest power conversion efficiency of ~3.2% was realized in bulk heterojuction photovoltaic device consisted of the ID3T as donor and PC70BM as acceptor. This work demonstrates the great potential of isoindigo moieties as electron deficient units as well as guideline for synthesis of donor-acceptor-donor (D-A-D) small molecules for realizing highly efficient solution processed organic photovoltaic devices.

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Anchor and Mooring Line Analysis in Cohesive Seafloor (해성점토지반에 관입된 앵커 및 닻줄의 변형해석)

  • Han Heui-Soo;Jeon Sung-Kon;Chang Dong-Hun;Chang Seo-Yong
    • Journal of the Korean Geotechnical Society
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    • v.22 no.3
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    • pp.37-43
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    • 2006
  • An analytical solution method capable of determining the geometric configuration and developed tensile forces of mooring lines associated with fixed plate/pile or drag anchors has been developed. The solution method, satisfying complete equilibrium conditions, is capable of analyzing multi-segmented mooring lines that can consist of either chains, cables, or synthetic wires embedded in layered seafloor soils. The solution method utilizes a systematic iterative search method based on specific boundary conditions. This paper describes the principles associated with the development of the solution for the mooring line analysis. Comparisons of predictions with results from a series of field tests of mooring lines on various types of drag anchors are also described. Comparisons include the tension in anchor, the length of mooring line on the bottom, and the angle of mooring line at the water surface buoy. The results indicate that the analytical solution method is capable of predicting the behavior of mooring lines with high degree of accuracy.

Basic Study for Solvent Extraction Separation of Mo from Synthetic Leaching Solution of Inconel713C by Alamine336 (Inconel713C 모사 용액으로부터 Alamine336을 통한 Mo의 용매추출분리를 위한 기초 연구)

  • Park, Sang-ryul;Ahn, Jong-gwan
    • Resources Recycling
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    • v.27 no.4
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    • pp.16-22
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    • 2018
  • Inconel713C which of a commercial Ni super alloy have the compositions of 70 wt.% Ni, 12 wt.% Cr, 6 wt.% Al and 4 wt.% Mo. In this study, solvent extraction has been performed to separate Mo from the synthetic leaching solution, formation of Inconel713C alloy similarly and is found the optimum conditions of recovery of Mo from the leaching solution. The effects of some variables, such as the nature and concentration of the extractants, $H_2SO_4$ concentrations, and the presence of impurities were investigated. The extraction percentage of Mo by Cyanex272 is 96% in the condition of pH 1 and 4% of concentration of Cyanex272 but Alamine336 is 99% in the condition of the range of pH 1 to 4 and 1 wt.% of concentration of Alamine336. In the case of Alamine336, the extraction percentage of Mo is increased by increasing of the concentration of Alamine336. The optimum condition of this experiment is pH 1 in aqueous phase, 1% concentration of Alamine336 and activation ratio of $H_2SO_4$ 1:0.5.

Preparation of Cellulose Nanofibril/Regenerated Silk Fibroin Composite Fibers

  • Lee, Ji Hye;Bae, Chang Hyun;Park, Byung-Dae;Um, In Chul
    • International Journal of Industrial Entomology and Biomaterials
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    • v.26 no.2
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    • pp.81-88
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    • 2013
  • Wet-spun silk fibers have attracted the attention of many researchers because of 1) the unique properties of silk as a biomaterial, including good biocompatibility and cyto-compatability and 2) the various methods available to control the structure and properties of the fiber. Cellulose nanofibrils (CNFs) have typically been used as a reinforcing material for natural and synthetic polymers. In this study, CNF-embedded silk fibroin (SF) nanocomposite fibers were prepared for the first time. The effects of CNF content on the rheology of the dope solution and the characteristics of wet-spun CNF/SF composite fibers were also examined. A 5% SF formic acid solution that contained no CNFs showed nearly Newtonian fluid behavior, with slight shear thinning. However, after the addition of 1% CNFs, the viscosity of the dope solution increased significantly, and apparent shear thinning was observed. The maximum draw ratio of the CNF/SF composite fibers decreased as the CNF content increased. Interestingly, the crystallinity index for the silk in the CNF/SF fibers was sequentially reduced as the CNF content was increased. This phenomenon may be due to the fact that the CNFs prevent ${\beta}$-sheet crystallization of the SF by elimination of formic acid from the dope solution during the coagulation process. The CNF/SF composite fibers displayed a relatively smooth surface with stripes, at low magnification (${\times}500$). However, a rugged nanoscale surface was observed at high magnification (${\times}10,000$), and the surface roughness increased with the CNF content.

Nasal Absorption of Procyclidine in Rats and Dogs

  • Jang, Eun-Ju;Lee, Young-Joo;Chung, Suk-Jae;Shim, Chang-Koo
    • Archives of Pharmacal Research
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    • v.24 no.3
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    • pp.219-223
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    • 2001
  • Nasal absorption of procyclidine, a synthetic anticholinergic compound, was investigated in Wistar rats and Beagle dogs. The dosing solution was prepared by dissolving$^{14}C$-procyclidme in 50% ethanolic saline. The dosing solution was administered intravenously and intranasally to rats at a dose of 0.6 mg/kg (i.e., $60{\mu}$l/kg in the form of a 1% w/v solution), and intravenously, orally and intranasally to doss at a dose of 0.3 mg/kg(i.e., $6{mu}$l/kg in the form of a 5% w/v solution). Blood samples were taken from an artery of the animals through the catheter for periods of 1200 (for rats) and 1440 min (for dogs), and the radioactivity in the samples was determined by liquid scintillation counting. The nasal bioavailability of Procyclidine in rats and dogs, based on the radioactivity was calculated to be 81.1 and 98.6% respectively. In both rats and dogs, the plasma profiles of procyclidine following nasal administration were very close to those following intravenous administration, leading to nearly superimposable profiles between the two protocols. In dogs, nasal administration resulted in significantly higher plasma concentrations during the first 30 min period compared to oral administration, suggesting the superiority of the nasal route over the oral route in terms of a prompt expression of the pharmacological effect of the drug. The results obtained in this study indicate that procyclidine is rapidly and nearly completely absorbed via the nasal route. In conclusion, nasal administration represents a viable alternative to intravenous administration in the case of procyclidine.

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