• Journal of the Korean Solar Energy Society
• /
• v.23 no.2
• /
• pp.71-79
• /
• 2003

The goal of this paper is to measure and compare the performance of solar heat pump for refrigerants. To accomplish the goal, solar heat pump with aluminum roll bond type evaporator and indoor heat exchanged(condenser) was built. The test results showed that the COP and heating capacity of HFC-32/125/134a(23/25/52 wt%, $CH_2F_2/CF_3CHF_2/CF_3CH_2F$) were higher than those of HCFC-22$(CHClF_2)$. A study proved that best conditions to use heating system that is about $40m^2$ and $80m^2$. The COP range of the whole system was from 4 to 6 according to the solar collector's area variation. Hydrochlo-rofluorocarbon HCFC-22$(CHClF_2)$ is included in the compound to be controlled. HFC-32/125/134a(23/25/52 wt%, $CH_2F_2/CF_3CHF_2/CF_3CH_2F$) is the most suitable replacement HCFC-22$(CHClF_2)$ in solar heat pump application. The solar heat pump system was designed to show the best efficiency that the room temperature make $18\sim20^{\circ}C$ and $23\sim25^{\circ}C$ in Seoul during the fall season.

• Biomedical Science Letters
• /
• v.16 no.4
• /
• pp.271-277
• /
• 2010

This study was conducted to investigate the biological activities of Areca catechu L. The antioxidative, fibrinolytic, thrombin inhibitory, and ${\alpha}$-glucosidase inhibitory activities of Areca catechu L extracted with hexane, $CHCl_3$, ethyl acetate, butanol, and water were measured. The water fraction showed the highest extraction yield at 3.65% (w/w). The butanol, $CHCl_3$, water, and ethyl acetate fractions showed strong antioxidative activities at 81.6%, 87.1%, 88.0%, and 89.5%, respectively. The fibrinolytic activity was strong only in the ethyl acetate fraction at 0.84 plasmin units/ml. The 100-fold dilution of the water fraction had the strongest thrombin inhibitory activity at 59.2%. The 100-fold dilution of butanol fraction displayed the strongest ${\alpha}$-glucosidase inhibitory activity at 88.6%. In conclusion, the extracts of Areca catechu L hold promise for use in the development of biofunctional foods to prevent cardiovascular diseases.

• Korean Journal of Pharmacognosy
• /
• v.30 no.3
• /
• pp.332-334
• /
• 1999

Corydalis Tuber has been used in traditional medicine for an analgesic, antispasmodic and gastric ulcers. For the quality control on this drug, isolation and quantitative determination of berberine and coptisine from Corydalis ternata Nakai (Papaveraceae) has been conducted by using HPLC method. Berberine and coptisine in quarternary alkaloidal fraction from the crude drug were separated on silicagel column using a $CHCl_3:MeOH\;(85:15)$ and $CHCl_3:MeOH:H_2O\;(70:30:4)$ as an eluent, and the average contents were about 0.93 and 0.36%.

• Journal of Adhesion and Interface
• /
• v.17 no.4
• /
• pp.141-148
• /
• 2016

In this work, mesoporous silica (SBA-15) was synthesized via self-assembly process using triblock copolymer ($PEO_{20}PPO_{70}PEO_{20}$, P123) as template and tetraethyl orthosilicate (TEOS) as silica source under acidic condition. SBA-15 have high surface area ($704m^2g^{-1}$) and uniform pore size (8.4 nm) with well-ordered hexagonal mesostructure. Spiropyran-functionalized SBA-15 (Spiropyran-SBA-15) was synthesized via post-synthesis process using 3-(triethoxysilyl)propyl isocyanate (TESPI) and 1-(2-Hydroxyethyl)-3,3-dimethy-lindolino-6'-nitrobenzopyrylo-spiran (HDINS). Spiropyran-SBA-15 was produced with hexagonal array of mesopores without damage of mesostructre. Surface area and pore size of Spiropyran-SBA-15 were $651m^2g^{-1}$ and 8.0 nm, respectively. Optochemical properties of Spiropyran-SBA-15 was studied with chemical vapors such as EtOH, THF, $CHCl_3$, Acetone and HCl. Main peaks of photofluorescence of Spiropyran-SBA-15 exhibited blue shift in the range of 603.4~592.1 nm after exposure under EtOH, THF, $CHCl_3$, and Acetone vapors. Normalized peak intensities decreased in the range of 0.8~0.3. The main peak of photofluorescence of Spiropyran-SBA-15 showed significant blue shift of 592.1 nm after exposure under HCl vapor, while normalized peak intensity decreased to 0.1.

• Journal of the Korean Chemical Society
• /
• v.35 no.5
• /
• pp.512-519
• /
• 1991

The axial ligations of nitrogenous bases (pyridine, imidazole, 1-methylimidazole and 2,6-lutidine) to Zn(II)-, Cu(II)-, and Ni(II)-tetrakis(o-chlorophenyl)porphyrin(o-ClTPP), and -tetraphenylporphyrin (TPP) were investigated in organic solvents $(CH_2Cl_2,\;C_6H_6,\;CH_3NO_2,\;(CH_3)_2CO,\;CHCl_3,\;DMF\;and\;DMSO)$ and at 0.01M of ionic strength. The equilibrium constants for the ligation reactions of methalloporphyrins were determined using spectrophotometric method at 15∼35${\circ}C$. In case of M(II)-TPP the equilibrium constants K were considerably larger than those of M(II)-(o-Cl)TPP, depending on steric effect of the porphyrin. The linear relationships between logK of the axial ligation and $pK_a$ of nitrogenous base were shown in M(II)-TPP, but not in M(II)-(o-Cl)TPP. The stabilities of MTPP(L) were controlled by the reation enthalpy and entropy, while those of M(o-Cl)TPP almost by the reaction entropy. The coordinating power of solvent to the methalloporphyrin were also studied in $CHCl_3,\;(CH_3)_2CO$, DMF and DMSO. From those results the solvent effects on the equilibrium constants were discussed.

• Korean Journal of Food Science and Technology
• /
• v.29 no.1
• /
• pp.156-160
• /
• 1997

The monoamine oxidase (MAO, EC 1.4.3.4) plays a central role in the metabolism of many amines including the neurotransmitter monoamines. MAO is a flavoprotein found exclusively in the mitochondrial outer membrane, occuring in the MAO-A and MAO-B subtypes. MAO-A deaminates serotonin and noradrenaline much better than phenethylamine (PEA) or benzylamine (BA), and is preferentially inhibited by clorgyline, whereas MAO-B prefers PEA and BA as substrates and is preferentially inhibited by deprenyl. MAO inhibitors were among the first drugs used in the treatment of depression, and it is known to be the inhibition of MAO-A which is important for the antidepressant effect of MAO inhibitors. For the purpose of evaluating MAO inhibitory activities from natural resources, three kinds of edible mushrooms were screened by tracing the inhibitory activities against rat brain mitochondrial MAO-A, utilizing serotonin as a substrate and rat liver mitochondrial MAO-B utilizing benzylamine as a substrate. Among the tested mushrooms, Ganoderma lucidium and Lentinus edodes showed the weak inhibitory activities against MAO-B.

• Macromolecular Research
• /
• v.10 no.5
• /
• pp.282-285
• /
• 2002

In this paper, we report a modified technique for the production of oriented continuous nanofibers instead of non-woven mats using a rapidly rotating collection device. We are interested in retaining physical properties such as electrical conductivity of fiber bundles in their axial direction. The experiments were performed using polyethylene oxide (PEO) and its blend with polyaniline (PANI). According to the results, a typical fiber with a uniform diameter of about 100 nanometer was produced. The fibers from the PEO/ CHCl$_3$ solution show high crystallinity and good orientation whereas the fibers from the blend solution of PEO/PANI/m-cresol and CHCl$_3$ show no preferred orientation. However, the fibers of the blend exhibit high electrical conductivity of 33 S/cm for a fiber bundle at a PANI level of 50 %.

• International Journal of Oral Biology
• /
• v.35 no.4
• /
• pp.177-184
• /
• 2010

In our present study, we investigated the effects of continentalic acid on Streptococcus mutans (S. mutans) biofilm. Methanol extract of Aralia continentalis (A. continentalis) was suspended in water and sequentially partitioned with CHCl3, ethyl acetate (EtOAc), and n-butanol (n-BuOH). The CHCl3 fraction showed the highest activity and an antibacterial compound against S. mutans was isolated from this preparation through various chromatography methods by bioassay guided fractionation. MS, $^1H-NMR$ and $^{13}C-NMR$ analysis showed that the active principle was continentalic acid which was confirmed to show significant inhibitory effects against S. mutans biofilm. These results may provide some scientific rationale for the traditional use these extracts for the treatment of dental diseases.

• Korean Journal of Plant Resources
• /
• v.25 no.5
• /
• pp.640-646
• /
• 2012

This research was attempted to determine the composition of flavone glycosides (luteolin 7-O-glucoside, luteolin 7-O-glucuronide, linarin) in addition to luteolin simultaneously in aerial part of Youngia japonica (Compositae) by high-performance liquid chromatography. The MeOH extract was further fractionated into the three parts, $CHCl_3$ fraction, EtOAc fraction and BuOH fraction, to investigate the contents of the four flavones in the three fractions. The content of luteolin 7-O-glucuronide (10.07 mg/g) was highest in the MeOH extract among those of the flavones. These four compounds were observed to be less than 1.0 mg/g in $CHCl_3$- and EtOAc fractions but relatively high in BuOH fraction.

• Journal of Physiology & Pathology in Korean Medicine
• /
• v.21 no.1
• /
• pp.70-75
• /
• 2007

In the present study, we has been isolated the anti-cariogenic component, stigmasterol, from Aralia continentalis (A. continentalis) and identified by MS, $^1$H-NMR and $^{13}$C-NMR and also investigated the anti-cariogenic properties of stigmasterol. The methanol extract of ,A. continentalis showed concentration-dependent inhibitory activity against the growth and acid production of S. mutans. The MeOH extract was suspended in H$_2$O and sequentially partitioned with n-hexane, CHCl$_3$, EtOAc, and n-BuOH. The CHCl$_3$ fraction showed remarkable antibacterial activity against S. mutans. The anti-cariogenic compound, stigmasterol, has been isolated successively through the screening system and various chromatography methods. Anti-cariogenic properties of stigmasterol were also investigated. From this active chloroform subfraction, isolation and identification finally gave (24E)-stigmasta-5,22-dien-3${\beta}$-ol (stigmasterol) {[a]$_D\;^{25}$ -48.33$^{\circ}C$(C 0.28, CHCl$_3$)} by spectroscopic methods (MS, $^1$H-NMR and $^{13}$C-NMR) as an active principle. The compound, stigmasterol, showed significant growth, acid production, adhesion and water-insoluble glucan synthesis inhibitory effect against S. mutans. These results suggest that stigmasterol from ,A. continentalis may inhibit cariogenic properties of S. mutans and these properties may provide some scientific rationales that the local inhabitants used the extracts for treatment of dental diseases.