• Carbon letters
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• 제10권4호
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• pp.329-334
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• 2009

In this work, the effect of carbon nanofibers (CNFs) addition on physicochemical characteristics of CNFs-reinforced epoxy matrix nanocomposites was studied. Poly(amide imide) solutions in dimethylformamide were electrospun into webs consisting of $250{\pm}50$ nm fibers which were used to produce CNFs through stabilization and carbonization processes. As a result, the CNFs with average diameter of $200{\pm}20$ nm were obtained after carbonization process. The nanocomposites with CNFs showed an improvement of thermal stability parameters and fracture toughness factors, compared to those of the specimen without CNFs, which could be probably attributed to the higher specific surface area and larger aspect ratio of CNFs, resulting in improving the mechanical interlocking in the nanocomposites. Also, the applied external loading can effectively transfer to CNFs because strong interactions are resulted between the epoxy matrix and the CNFs.

• 한국환경과학회지
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• 제15권5호
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• pp.447-459
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• 2006

Long-term trends and distribution patterns of water quality were investigated in the Cheonsu Bay of Korea from 1983 to 2004. Water samples were collected at 4 stations and physicochemical parameters were analyzed including water temperature, salinity, suspended solids (SS), chemical oxygen demand (COD), dissolved oxygen (DO) and nutrients. Spatial distribution patterns were not clear between stations but the seasonal variations were distinctive except COD, SS and nitrate. Twenty two year long-term trend analysis by PCA revealed the significant changes in water quality in the study area. Water quality during 1980's and early 1990's showed high SS, low nutrients and low COD which increased during the mid and late 1990's and early 2000's. Overall water duality in the Cheonsu Bay indicated the increase in nutrients and COD concentration.

• 한국조리학회지
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• 제14권4호
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• pp.385-397
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• 2008

The effects of defatted soy flour on the physicochemical characteristics of dough and bread-making properties were studied with sodium stearyl lactylate(SSL) as an emulsifier. Defatted soy flour was added to the wheat flour at the level of 0$\sim$12%. The emulsifier was added to the wheat flour-defatted soy flour blends at the level of 0.5 and 2%. Set-back and consistency in amylogram were significantly decreased as the level of soy flour was increased. On comparison with control, the bread made from defatted soy flour especially had less specific loaf volume. The specific loaf volume of wheat flour-defatted soy flour bread prepared with 0.5$\sim$2% SSL was better than that without SSL. Decrease of L value (lightness) of crust color and decrease of L value of crumb color were shown with the increase of defatted soy flour. From the result of sensory evaluation, wheat flour-defatted soy flour bread containing up to 6% defatted soy flour with 1.0% SSL were rated as high quality. Most of texture parameters of bread increased with the increase of defatted soy flour and decreased with increase of SSL. Considering the volume and sensory characteristics of bread, bread prepared with 6% defatted soy flour and 1% SSL was regarded as highly acceptable.

• ALGAE
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• 제20권1호
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• pp.43-52
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• 2005

A study on the seasonal changes in the phytoplankton community was carried out in four aquaculture ponds of Bangladesh over a period of 16 months from August 2000 to November 2001. Out of 45 phytoplankton species identified, 30 belong to Cyanophyceae, 7 to Chlorophyceae, 5 to Bacillariophyceae and 3 to Euglenophyceae. The highest phytoplankton abundance was observed in spring followed by early autumn, summer, and the lowest was in winter. The annual succession of Cyanophyceae was characterized by spring and early autumn period dominated by Microcystis sp. Anabaena sp. and Planktolymbya sp. with Microcystis sp. as the main blue-green algae represented. Chlorophyceae was characterized by rainy season domination of Chlorella vulgaris, Pediastrum sp. and Scenedesmus denticulatus with maximum abundance of Chlorella vulgaris. Whereas Bacillariophyceae was dominant during the winter period. Navicula angusta and Cyclotella meneghiniana were the most frequently occurring species of Bacillariophyceae throughout the study period. Euglenophyceae was dominant in late autumn and Euglena sp. was the dominant species. The effect of various physicochemical water quality parameters on the seasonal distribution and succession of the above mentioned phytoplankton population as well as the interaction and eutrophication are discussed.

• 동아시아식생활학회지
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• 제7권1호
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• pp.47-55
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• 1997

This study aims to know what the physicochemical properties and physical properties of the Korean traditional rice cake injulmi made from persimmon powder and glutinous rice(powder), and to come up with a standard recipe of it with the premixed powder of persimmon and glutinous rice. Cooked rice powder with 9 different levels of persimmon in cooling dough(75, 100 and 150${\mu}{\textrm}{m}$ power with each 20, 40, and 60%) was tested for rheological parameters, the rate of swelling, degree of gelatinization, sensory evaluation, and the observation of cross section used to electronmicroscope. 1. sensory evaluation conducted by 20 university students as panelists showed that mixed glutinous rice powder and persimmon powder lost their regular forms. increase in persimmon powder content increased a thin layer of starch granule, presumably due to sugar and fiber in the mixed persimmon powder granule. 3. In cooking the rice cake with 20~60% of persimmon, it showed 6.3 to 5.5 pH. 4. Quantitative description analysis conducted by 20 university student s panelists showed that sample that sample C was preferred among 9 samples. From these results, it was concluded that glutinous rice cake cooked with 20% of persimmon powder was quiet acceptable. Optimum cooking condition for the glutinous rice with persimmon powder rice cake was 30min of cooking time and 25$0^{\circ}C$ of cooking temperature with gas oven.

• 한국자원식물학회지
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• 제24권3호
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• pp.304-308
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• 2011

The survival rate and thermal, crystal, and physicochemical properties of starches in chinese yam tubers irradiated to proton beam were determined. Survival rate was decreased with increased proton beam irradiation. Amylose content of D. opposita starches from different proton beam ranged from 13.2% to 17.8%. D. opposita starch at 5 Gy showed the highest ${\Delta}H_{gel}$ values (12.0 J/g) while D. opposita starch at 25 Gy showed the lowest values (10.1 J/g). Several parameters such as PKV (peak viscosity), HPV (Hot peak viscosity) and CPV (Cooling peak viscosity) decreased with the increase in irradiation dose. The degrees of crystallinity of the D. opposita starches at 5, 10, 15, 20 and 25 Gy were 37.2, 38.3, 38.9, 39.2 and 39.9%, respectively. It might be deduced that proton beam irradiation causes changes of starch, especially at high dose irradiation.

• 한국축산시설환경학회지
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• 제15권3호
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• pp.289-296
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• 2009

The effects of the processing mixture of pig manure and various organic wastes on the growth, cast production of earthworm, and conversion of organic matter to earthworm tissues by vermicomposting. The substances used in this experiments were sawdust, rice hull, coffee waste, brewery waste, litters, turfgrass cutting residues, rice bran, vegetable wastes and rice straw and were mixed with pig manure at a ratios of 50:50 (v/v), and pig manure 100% (control), respectively. The highest values of growth parameters, cast production and conversion efficiency of organic matter to earthworm tissues were obtained at the mixtures of pig manure with coffee waste, it may due to the favourable diet conditions to process with pig manure by vermicomposting. But, all of the earthworm died in the pig manure 100% (control) and pig manure with vegetable wastes treatments by vermicomposting was impossible in this experiment. The vermicast contained a higher values of total nitrogen, available phosphorus, exchangeable cations and cation exchange capacity than their parent materials with increased availability of nutrients and improved physicochemical properties.

• 산업기술연구
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• 제26권A호
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• pp.189-197
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• 2006

Water shortage as well as water control problems including urban flood and drought have led to developing technologies for rainwater utilization in order to provide a sustainable water supply. However, relatively few works have been done to improve the water quality during rainwater utilization. Therefore, in this study, the characteristics of rainwater were examined in terms of pollutant concentrations and outflow rate. A experimental rain and roof model($1m{\times}1m$) were produced to evaluate wash-off properties of pollutants. And rainfall intensity were standardized in 10 mm/hr, a experimental model roof catchment surface were coated in $TiO_2$ photocatalyst. Samples of runoff rainwater collected from a experimental model were analyzed for physicochemical parameters such as Turbidity, Suspended Solid, EC. The results show that the first flush of rainwater contains substantial amount of contaminants that potentially pollute the whole rainwater. Surface treatment of roof catchment area using $TiO_2$ photocatalyst allowed a better runoff property of rainwater because of its improved hydrophilicity.

• Natural Product Sciences
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• 제11권2호
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• pp.58-62
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• 2005

Pygmaeopremna herbacea (Roxb.) Mold. (Verbenaceae) is a small herb or sometimes an undershrub arising from a perennial rootstock. The dry roots are dark muddy brown in colour having root nodules. Its extensively developed roots are widely used in tribal medicine. They are used as an aphrodisiac and for the treatment of gout, rheumatism and ulcers. This study deals with the detailed pharmacognostical evaluation of the dried roots and root nodules of P. herbacea which includes macro and microscopic studies, determination of physicochemical parameters and chemoprofiling of the extract using HPTLC fingerprint profiles. It was observed that the roots consist of a well developed cortical region consisting of tangentially elongated thin walled parenchymatous cells and contain polygonal stone cells as well as compound starch grains. Also the pith was parenchymatous. The HPTLC fingerprint profile of the methanolic extract showed the presence of seven major bands. Such an analysis may thus be utilized in identifying P. herbacea and in differenciating it from other species which are similar to it or are used as its adultrants/substitutes under the same vernacular name of Bharangi.

• Natural Product Sciences
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• 제11권2호
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• pp.109-114
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• 2005

Leucas aspera Link. (Lamiaceae) is an important medicinal plant in indigenous systems of medicine in India and commonly known as 'Thumbai'. It has various ethnomedicinal values as various traditional communities find diverse medicinal properties. It is used as antipyretic, stimulant, expectorant and diaphoretic drug. The present communication deals with the detailed pharmacognostical evaluation of whole plant of L. aspera collected from five different geographical zones of the country-Uttar Pradesh, Orissa, Karnataka, West Bengal and Gujarat. The botanical characters and TLC fingerprint profile of all the samples were quite similar but some variations were observed in physicochemical parameters. However, some microscopical characters and TLC profile can be used as diagnostic characters for identification of L. aspera, for example amphistomachic leaves and two types of trichomes-abundant, non glandular, uniseriate, 1-3 celled and few glandular, 2-5 celled stalk with rounded tip. Presence of some components at $R_fs-0.56$, 0.65 and 0.76 under UV 366 and at $R_fs-0.31$, 0.43, 0.60, 0.76 and 0.82 under visible light after derivetization in TLC profile may also be used as diagnostic character.