• Natural Product Sciences
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• v.18 no.1
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• pp.39-46
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• 2012

In Korea, the leaves of Sonchus brachyotus (Compositae), an edible mountainous vegetable, are traditionally used to treat hepatitis and hemorrhage and are known to have diuretic action. The aqueous ethanolic extract of this plant was selected in our screening experiment using the peroxynitrite ($ONO_2^-$)-scavenging assay, and the present study was performed to qualitatively and quantitatively identify the active compounds from S. brachyotus and validate the present high-permormance liquid chromatography (HPLC) coupled with ultraviolet absorption detection method based on accuracy, precision and repeatability. Five phenolic substances including the main compound, luteolin $7-O-{\beta}-D$-glucuronopyranoside, as well as chlorogenic acid, luteolin 7-O-rutinoside, luteolin $7-O-{\beta}-D$-glucopyranoside, and luteolin, were found in the aqueous ethanolic extract of S. brachyotus. In the HPLC validation experiment, the linearity of the four compounds was established by $R^2$ values of more than 0.999 within the test ranges, and the recovery rate ranged from 98.2 - 105.3%. Luteolin 7-O-glucuronide was a predominant compound (143 mg/g of extract and 18.3 mg/g of the dry weight of plant material) with a potent peroxynitrite-scavenging effect ($IC_{50}$, $1.02{\pm}0.08{\mu}M$). Luteolin and its three glycosides together with chlorogenic acid were qualitatively and quantitatively determined using an HPLC method validated in the present study.

• Clean Technology
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• v.7 no.2
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• pp.127-132
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• 2001

The effects of activated-carbon (AC) packing length on the Pressure Swing Adsorption (PSA) performance was investigated for the hydrogen separation from the multicomponent mixture gas. Linear driving force model was used to describe mass transfer between two phase and coupled Langmuir isotherm was used for each component as a nonlinear adsorption isotherm. When two adsorbents with a different adsorption capacity were packed consecutively in one bed, it is very important to determine the packing ratio of zeolite to activated carbon affecting the purity and recovery of the product. The activated carbon packing length in adsorption tower of 120 cm was determinated by the ending point of $CO_2$ contration. The optimum length of an activated carbon layer was 65 cm for production of high-purity hydrogen.

• Archives of Reconstructive Microsurgery
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• v.15 no.1
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• pp.1-9
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• 2006

The purpose of this study is to determine the effects of selective inducible nitric oxide synthase (iNOS) inhibitor N-[3-aminomethyl]benzyl]acetamidine (l400W) on the reperfused cremaster muscle. The extracellular superoxide dismutase knockout ($EC-SOD^{-/-}$) mice was used to make the experimental window for ischemia-reperfusion injury. The muscle was exposed to 4.5 h of ischemia followed by 90 min of reperfusion and the mice received either 3 mg/kg of 1400W or the same amount of phosphate buffered saline (PBS) subcutaneously at 10 min before the start of reperfusion. The results showed that 1400W treatment markedly improved the recovery of the vessel diameter and blood flow in the reperfused cremaster muscle compared to that of PBS group. Histological examination showed reduced edema in the interstitium and muscle fiber, and reduced nitrotyrosine formation (a marker of total peroxinitrite ($ONOO^-$) in 1400W-treated muscle compared to PBS. Our results suggest that iNOS and $ONOO^-$ products are involved in skeletal muscle I/R injury. Reduced I/R injury by using selective inhibition of iNOS is perhaps via limiting cytotoxic $ONOO^-$ generation, a reaction product of nitric oxide (NO) and superoxide anion ($O_2^-$). Thus, inhibition of iNOS appears to be a good treatment strategy in reducing clinical I/R injury.

• Proceedings of the Korea Society for Energy Engineering kosee Conference
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• 2007.11a
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• pp.187-192
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• 2007

A project is being implemented to develop the long distance energy transport technology using the chemical reactions. This project can be classified into three main research categories covering heat recovery reaction, long distance energy transport, and heat generation reaction. In this study, the methanol is selected as a system material since it shows several unique superior characteristics as follows: gaseous state of reactant and product, large heat of reaction, high yields of reaction at relatively low temperature, and also steady and economical supply. Furthermore, it is anticipated that the outcomes of this study can be widely applied to the related industries. A feasibility study was carried out to evaluate the economics of this technology which study was based on the following case: 10,000 households, 15km distance energy transportation, utilization of waste heat from power plant.

• Advances in concrete construction
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• v.2 no.4
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• pp.249-259
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• 2014

Mortar is a masonry product which is matrix of concrete. It consists of binder and fine aggregate and moreover, it is an essential associate in any reinforced structural construction. The strength of mortar is a special concern to the engineer because mortar is responsible to give protection in the outer part of the structure as well as at a brick joint in masonry wall system. The purpose of this research is to investigate the compressive strength and tensile strength of mortar, which are important mechanical properties, by replacing the cement and sand by stone dust. Moreover, to minimize the increasing demand of cement and sand, checking of appropriateness of stone dust as a construction material is necessary to ensure both solid waste minimization and recovery by exchanging stone dust with cement and sand. Stone dust passing by No. 200 sieve, is used as cement replacing material and retained by No. 100 sieve is used for sand replacement. Sand was replaced by stone dust of 15%, 20%, 25%, 30%, 35%, 40%, 45% and 50% by weight of sand while cement was replaced by stone dust of 3%, 5%, and 7% by weight of cement. Test result indicates that, compressive strength of specimen mix with 35% of sand replacing stone dust and 3% of cement replacing stone dust increases 21.33% and 22.76% respectively than the normal mortar specimen at 7 and 28 days while for tensile it increases up to 13.47%. At the end, optimum dose was selected and crack analysis as well as discussion also included.

• Journal of the Korean Applied Science and Technology
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• v.32 no.1
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• pp.116-126
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• 2015

The present study utilized a shuttle mechanism of wet chemical absorption using MEA. In addition, industrial by-products containing a large amount of inorganic alkali substances were utilized for wet carbonization process. Chemical pretreatment of industrial by-products extracted calcium ions. ICP result of calcium ion was obtained up to 17,900 ppm(17.9%) by acidic substance. And also, In this work, 94% of recovery rate was obtained using wet MEA absorption process from $CO_2$ flow at the ambient condition. Through the liquid carbonation process, a sludge was fixed with rate of 0.175 mg of $CO_2$ per mg of sludge. It was found from XRD results that the structure of final product was composed of a calcite structure which is general structure of $CaCO_3$.

• Journal of the Korea Organic Resources Recycling Association
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• v.12 no.2
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• pp.52-60
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• 2004

The basic approach to sewage sludge is organic waste minimization, promotion of energy recovery; volume and weight reduction by final treatment, and environmentally final disposal of natural circulation. Dry and pyrolysis of maize was experimentally investigated in full-scale rotary kiln in semi-continuous operation. The operational parameters varied are the operating temperature $160{\sim}175^{\circ}C$ of dry and $450{\sim}800^{\circ}C$ of pyrolysis, the solids residence time 9 min for pyrolysis. Important parameters studied include the running time, water content of sewage sludge, solids amount of sewage sludge(TS%) by the varied temperature. Also, with the increasing of temperature, how the yield of oil and char product change was observed, and the distribution of gas production components was observed. The gas of $C_1{\sim}C_3$ yield increased and oil of $C_4{\sim}C_6$ yield decreased along with pyrolysis temperature of $670^{\circ}C$ by the run time of 9 min.

• The Journal of the Korea Contents Association
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• v.13 no.1
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• pp.287-293
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• 2013

Dandelion(Taraxacum officinale), an oriental herbal medicine, has been shown to favorably affect choleretic, antioxidative and protection of gastric mucosa. The protective effects of common dandelion leaf and root extract were investigated by irradiation in Sprague-Dawley rats. Male SD rats, 6weeks, were orally injected with dandelion extract(100mg/kg) for 10days. Immediately after final injection, rats were whole body irradiated with 10Gy used irradiation facility(Elekta Linac, Sweden). At 24h-15days after irradiation, complete blood counted test and apoptosis in jejunal crypt cell. Stimulated recovery by the extract was observed in platelet but was not showed in the erythrocyte and leucocyte. The jejunal crypt cells were protected significantly(p<0.05) and the radiation-induced apoptosis was reduced(p<0.05). The survival rate were carried for 15days, the survival ratio was 15% and 85% for the control and experimental group. Observations intestinal inhibition of cell death, intestinal mucosa and tissue decreased systemic inflammation and vacuole. Base on these data, we propose that dandelion may be a useful radioprotector, especially since it is a relatively nontoxic natural product.

• Journal of the Korean Society of Food Science and Nutrition
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• v.41 no.6
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• pp.870-874
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• 2012

The objective of this study was to determine the content of capsaicinoids in different commercial pepper powders and pepper-containing products in the Korean market. The two major capsaicinoids in the samples, capsaicin and dihydrocapsaicin, were analyzed using reversed-phase HPLC. The levels of capsaicin and dihydrocapsaicin in pepper powders and pepper-containing products ranged from 0.21 to 78.24 and 0.20 to 38.82 mg/100 g sample, respectively. Pepper powders contained generally higher amounts of capsaicin and dihydrocapsaicin than pepper- containing products. In addition, the analytical method validation parameters including accuracy, precision, and specificity were provided to ensure the validity of the extraction procedure for capsaicinoid analysis. Overall recovery from pepper powder and pepper paste was close to 100% (n=3). The results of validation parameters indicated that the present method was reliable and reproducible for the HPLC analyses of capsaicin and dihydrocapsaicin in commercial pepper products.

• Journal of Microbiology and Biotechnology
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• v.19 no.1
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• pp.65-71
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• 2009

Microbial oxidoreductive systems have been widely used in asymmetric syntheses of optically active alcohols. However, when reused in multi-batch reaction, the catalytic efficiency and sustainability of non-growing cells usually decreased because of continuous consumption of required cofactors during the reaction process. A novel method for NADPH regeneration in cells was proposed by using pentose metabolism in microorganisms. Addition of D-xylose, L-arabinose, or D-ribose to the reaction significantly improved the conversion efficiency of deracemization of racemic 1-phenyl-1,2-ethanediol to (S)-isomer by Candida parapsilosis cells already used once, which afforded the product with high optical purity over 97%e.e. in high yield over 85% under an increased substrate concentration of 15 g/l. Compared with reactions without xylose, xylose added to multi-batch reactions had no influence on the activity of the enzyme catalyzing the key step in deracemization, but performed a promoting effect on the recovery of the metabolic activity of the non-growing cells with its consumption in each batch. The detection of activities of xylose reductase and xylitol dehydrogenase from cell-free extract of C. parapsilosis made xylose metabolism feasible in cells, and the depression of the pentose phosphate pathway inhibitor to this reaction further indicated that xylose facilitated the NADPH-required deracemization through the pentose phosphate pathway in C. parapsilosis. moreover, by investigating the cofactor pool, the xylose addition in reaction batches giving more NADPH, compared with those without xylose, suggested that the higher catalytic efficiency and sustainability of C. parapsilosis non-growing cells had resulted from xylose metabolism recycling NADPH for the deracemization.