• Clean Technology
• /
• v.12 no.2
• /
• pp.53-61
• /
• 2006

A PGSS (Particles from Gas Saturated Solutions) process designed to generate nano-particles using supercritical fluids has been conducted for the fabrication of Poly(lactide-co-glycolide) (PLGA) microparticles that encapsulate a protein drug. It is demonstrated that the polymer and the dry powder of a protein can be mixed under supercritical carbon dioxide conditions and that the protein component retains its biological activity. In this experiment, the mixture of polymer which is plasticized and dry powder protein was sprayed to form solid polymer that encapsulate the protein. It is found that supercritical fluid process give fine tuning of particle size and particle size distribution by simple manipulations of the process parameters. Porous particles were formed with irregular shape. Protein encapsulated in the polymer was found to have enzymatic activity without significant loss of its initial value.

• Transactions of the Korean Society of Mechanical Engineers B
• /
• v.35 no.1
• /
• pp.53-60
• /
• 2011

In this study, an organic Rankine-cycle system using HFC-134a, which is a power cycle corresponding to a low-temperature heat source, such as that for geothermal power generation, was investigated from the view point of power optimization. In contrast to conventional approaches, the heat transfer and pressure drop characteristics of the working fluid within the heat exchangers were taken into account by using a discretized heat exchanger model. The inlet flow rates and temperatures of both the heat source and the heat sink were fixed. The total heat transfer area was fixed, whereas the heat-exchanger areas of the evaporator and the condenser were allocated to maximize the power output. The power was optimized on the basis of three design parameters. The optimal combination of parameters that can maximize power output was determined on the basis of the results of the study. The results also indicate that the evaporation process has to be optimized to increase the power output.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.51 no.spc1
• /
• pp.119-124
• /
• 2006

This study was carried out at the Chuncheon Substation, National Institute of Crop Science to determine the effect of cold water irrigation on the milling and polished quality of rice, as well as its physicochemical and amylogram characteristics, and palatability Chilling by Irrigation of cold water $(17^{\circ}C)$ induced delay of days to heading, reduction of culm length, inferiority of panicle exsertion and high sterility of panicle. Head rice ratio was decreased, while the percentage of chalky and creak rice increased with increasing sterility over from 20%. Protein content was gained 0.9-2.0% more than, while whiteness and palatability of the milled grain were reduced under cold water irrigation treatment. Significant decrease in maximum viscosity and breakdown viscosity of rice flour was investigated under cold water treatment by amylogram analysis, while the initial gelatinization temperature and setback viscosity were increased. Sensory panel test showed that the palatability of cooked rice was unfavorable and its stickiness was lower compared with that under normal condition. Differences in the aroma of cold-treated and untreated cooked rice were not performed significantly.

• Journal of Korea Water Resources Association
• /
• v.45 no.10
• /
• pp.1051-1067
• /
• 2012

Increased use of water curtain facilities to keep green house warm during winter cultivation has been known to cause excessive groundwater ion which might lead to decline of groundwater level, resulting in streamflow depletion. Therefore it is required to quantitatively assess the effects of groundwater ion on the streamflow depletion such as magnitude and extent. The objective of this study is to assess the change of stream-aquifer interaction according to groundwater ion near stream. To this end, a green house cultivation land in Sooha-ri, Sindun-myun, Icheon-si, Gyonggi-do was selected as a field experimental site, and monitoring wells were established near and within stream to observe the water level and temperature changes over a long period of time. From the observed water level and temperature data, it was found that the river reach of interest changed to a losing stream pattern during the winter cultivation season due to groundwater level decline around pumping wells near the stream. The continuous exchange rates between stream and aquifer were estimated by plugging the observed water level data series into the experimental relation between head difference and exchange rate, showing the streamflow depletion by 16% of the groundwater pumping rate in Feb, 2011.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
• /
• v.19 no.2
• /
• pp.99-108
• /
• 2014

One year long time-series current data were obtained at two stations (K1 and K2) located in the Usan Trough in the area north of Ulleungdo in the East Sea from September 2006. The observed data reveal enhanced seafloor flows in both stations with variabilities of about 20 days which is possibly governed by the topographic Rossby wave. After February 2007, strong flow in the upper layer in St. K1 appears throughout the mooring period and this is due to the passage of the warm eddy comparing with satellite sea surface temperature data. During this period, no significant correlation between the current in the upper layer and those in two deep layers is shown indicating the eddy does not affect flows in the deep ocean. It is also observed that the flow direction rotates clockwise with depth in both stations except for the upper of the K1. This implies that the deep flow does not parallel to the isobaths exactly and it has a downwelling velocity component. The possibility of the flow from the Japan Basin to the Ulleung Basin across the Usan Trough is not evidenced from the data.

• Journal of Applied Biological Chemistry
• /
• v.53 no.4
• /
• pp.219-224
• /
• 2010

This study was conducted to investigate the effect of medical herbs extracts on physicochemical characteristics of cooked rice. Three types (CLP 1, CLP 2, CLP 3) of extracts were prepared using 11 medicinal herbs, respectively. Polished rice was cooked with different concentration of medicinal herbs extracts by electric cooker. The moisture contents in cooked rice were decreased by increased concentration of herbs extracts, while total polyphenol contents were significantly increased. DPPH radical scavenging activities of cooked rice obviously were increased as herb extracts level increased. The consistency and setback value of the rice flour was reduced at all of the extracts, while breakdown and initial pasting temperature was increased. Color of cooked rice was shown different comparing to the control. However, the hardness, adhesiveness, springiness, cohesiveness and gumminess of cooked rice was increased depending on the concentration of extracts. These results showed that medicinal herbs extracts, which can benefit human health, is inducing the changes of physicochemical characteristics of cooked rice.

• Food Science and Preservation
• /
• v.18 no.2
• /
• pp.165-170
• /
• 2011

The physicochemical properties and cooking quality of Saechalssal bori (25% pearled ratio), which is a naked waxy barley, were investigated. The amylose, insoluble dietary fiber (IDF), soluble dietary fiber (SDF), total dietary fiber (TDF), and ${\beta}$-glucan contents of Saechalssal bori were 5.2, 10.8, 9.5, 20.3, and 3.7%, respectively. Pasting temperature, peak and final viscosity, and setback of Saechalssal bori were $66.5^{\circ}C$, 383.2, 231.3, and 55.6 RVU, respectively. The water absorption, expansibility, and soluble solid of Saechalssal bori were 232.2, 405.3, and 3.5%, respectively. As the ratio of water to grain increased, L value increased, whereas a and b values were decreased. The sensory evaluation showed that wateriness and overall acceptability increased with increasing ratio of water to grain, resulting in determining 2.1 times as the optimum ratio of water to grain. The cooked Saechalssal bori prepared using optimum condition had hardness (1.2 kg), cohesiveness (4.0), springiness (1.0), gumminess (5.1), chewiness (5.3), adhesiveness (0.2 kg), and A/H (0.8), respectively.

• Journal of the Korean Institute of Landscape Architecture
• /
• v.39 no.6
• /
• pp.118-125
• /
• 2011

This study was conducted to check danger of the cold injury by reviewing the lowest temperature by regions and the cold tolerance of Lagerstroemia indica and Pyracantha angustifolia. The cold tolerance of the samples treated at low temperature was evaluated by measuring electrical conductivity and observing browning of the cambium. It was proved that the lethal temperature of L. indica is below $-17.1^{\circ}C$, and that of P. angustifolia is below $-18.9^{\circ}C$. The frequency of the lowest temperature went down below $-17.1^{\circ}C$, was 7 times in Daejeon, 55 times in Cheongju and 72 times in Suwon for the last 45 years. In Daejeon, it has happened only once since 1975. The temperature dropped below $-18.9^{\circ}C$ 45 times in Cheongju and 32 times in Suwon during the same period, but it has not happened at all since 1991. It appears that the rising coefficient of the lowest temperature increases, as the latitude gets higher. As a result, L. indica and P. angustifolia which were planted in the central region of Korea, are considered in danger from freezing injury because the temperature can get very low intermittently in winter. But, the risk of freezing has reduced gradually as the lowest temperature raises each year.

• Journal of Hydrogen and New Energy
• /
• v.18 no.3
• /
• pp.230-237
• /
• 2007

Titania nanotube(TiNT) and CdS sol were synthesized by hydrothermal reaction under strongly basic condition and by precipitation reaction of $Cd(N0_3)_2$ and $Na_2S$ aqueous solutions, respectively. After preparing a series of CdS-TiNT composite films on $F:SnO_2$ conducting glass with variation of the mole ratio (r) of TiNT/(CdS+TiNT), their visible light absorption, photocatalytic activities for hydrogen production, and the photocurrent generation were examined. In general, this CdS-TiNT series showed lower photocatalytic activities and photocurrent generation under Xe light irradiation compared to their counterparts, i.e., CdS-$TiO_2$ particulate series. It appeared that TiNTs are not so effective photocatalyic material in spite of their larger specific surface areas compared to $TiO_2$ nanoparticles, because they indicate a poor crystallinity and less intimate interaction or contact with CdS particles owing to the tubular morphology and an easy agglomeration among themselves.

• Journal of Korean Society of Forest Science
• /
• v.99 no.1
• /
• pp.16-23
• /
• 2010

Experiments were performed for investigate the immune activities on human B and T cell growth and secretion of their cytokines. Also, antibodies in serum were investigated in female ICR mouse by feeding the extracts of Acer mono at dose of 30 and 100 mg/mL of one day orally for 15 days. The cytotoxicity of the samples on normal human cell (HEL299) was below 24.15% in adding the all extracts. Both human immune B and T cells were increased up to about 40% by the high pressure extraction process. The secretion of cytokines (IL-6, TNF-${\alpha}$) on human B and T cells were increased up to 20-50% by adding the high pressure extraction process compare to the hot water extraction process. Also, total serum IgG levels increased by feeding Acer mono extacts. It can be conclude that optimum condition for efficient extraction of Acer mono as functional materials is solvent extraction process using water with high pressure at below $100^{\circ}CA$ than typical process.