• Journal of the Korean Society for Aeronautical & Space Sciences
• /
• v.50 no.2
• /
• pp.127-135
• /
• 2022

Compared to the continuous increase of domestic nano-satellite development cases, the initial communication success rate is relatively low. In a situation where communication cases of LEO satellites using commercial satellite communication networks are increasing recently. In this situation, the SNIPE project developed by the KASI(Korea Astronomy and Space Science Institute), KARI(Korea Aerospace Research Institute), and Yonsei University apply an Iridium module for communication test to the SNIPE nano-satellites. Therefore, in this paper, the visibility analysis of the iridium module on the SNIPE satellite was analyzed under considering the orbital and communication environment of the iridium satellite constellation and the attitude control mode. In the case of LEO satellites, the communication possibility was limited due to the relatively small iridium communication coverage for high altitude and the high doppler shift considered in the iridium communication network. For this reason, in this paper, it could be simulated that there was a more performance difference according to the difference in relative RAAN(Right Ascension of Ascending Node) angle with the Iridium constellation. Finally, by checking the visibility of communication module under the tumbling situation that occurred during the initial deployment of the nano-satellite, the possibility of using the iridium communication technology was analyzed.

• Applied Chemistry for Engineering
• /
• v.33 no.4
• /
• pp.373-380
• /
• 2022

In this study, Chung's equations 1, 2, and 3 were extended to standardize smoke safety rating evaluation in case of fire, and Chung's equations-V, smoke performance index-V, and smoke growth index-V were calculated. Five types of wood were selected and their smoke indices were measured using the cone calorimeter method according to ISO 5660-1. The smoke risk was graded by the smoke risk index-VI according to Chung's equation-VI. Smoke risk index-VI increased in the order of PMMA (1) ≈ maple (1.01) < ash (1.57) < needle fir (4.98) < paulownia (46.15) < western red cedar (106.26). It was predicted that maple and ash had the lowest smoke risk, and paulownia and western red cedar had the highest. The five samples' CO mean production rate (COP_mean) was 0.0009~0.0024 g/s, indicating that these woods were incompletely burned than the polymethyl methacrylate (PMMA) reference material. Regarding the smoke properties of the chosen woods, the smoke performance index-V (SPI-V) increased as the bulk density increased, and the smoke risk index-VI (SRI-VI) decreased.

• Journal of the Korean Applied Science and Technology
• /
• v.40 no.2
• /
• pp.258-267
• /
• 2023

In this study, to investigate the possibility of using ethanol extract of Petasites japonicus (PJE) as a functional material, we investigated the activity of improving skin barrier and inflammation through UVB-induced human keratinocyte (HaCaT cell). As a result of confirming the antioxidant effect through DPPH radical scavenging activity, ABTS⁺ radical scavenging activity, and hydrogen peroxide scavenging activity, it was confirmed that it had an antioxidant effect similar to that of ascorbic acid, a control, at a concentration of 1 mg/ml. As a result of confirming the mRNA expression of the production ability of filaggrin and aquaporin-3 in HaCaT cells induced by UVB, it was confirmed that the reduced expression level by UVB stimulation increased in a concentration-dependent manner when the PJE was treated. It was confirmed that the mRNA expression of TNF-𝛼 and IL-1𝛽 were increased by UVB stimulation and decreased when the PJE was treated. As a result of the migration assay, it was confirmed that the proliferation of skin keratinocytes and the recovery rate of wounds were increased in a concentration-dependent manner. Based on the experimental results, it suggests that Petasites japonicus can be used as a functional cosmetic product that can improve skin moisturizing and skin barrier function.

• Journal of the Korean Institute of Gas
• /
• v.27 no.2
• /
• pp.71-78
• /
• 2023

In general, electric submersible pumps (ESPs), which have an average life of 1.0 to 1.5 years, experience a decrease in performance and a reduction in life of the pump depending on oil and gas reservoir characteristics and operating conditions in wells. As the result, the failure of ESP causes high well workover costs due to retrieval and installation, and additional costs due to shut down. In this study, a flow loop system was designed and established to predict the life of ESP in long­term operation of oil and gas wells, and the life cycle data of ESP from the time of installation to the time of failure was acquired and analyzed. Among the data acquired from the system, flow rate, inlet and outlet temperature and pressure, and the data of the vibrator installed on the outside of ESP were analyzed, and then the performance status according to long-term operation was classified into five stages: normal, advice I, advice II, maintenance, and failed. Through the experiments, it was found that there was a difference in the data trend by stage during the long­term operation of the ESP, and then the condition of the ESP was diagnosed and the failure of the pump was predicted according to the operating time. The results derived from this study can be used to develop a failure prediction program and data analysis algorithm for monitoring the condition of ESPs operated in oil and gas wells.

• Proceedings of the Plant Resources Society of Korea Conference
• /
• 2023.04a
• /
• pp.51-51
• /
• 2023

The world-wide rate of obesity is increasing continuously, representing a serious medical threat since it is associated with a variety of diseases including type 2 diabetes, cardiovascular disease, and numerous cancers. Sophora japonicais used as a traditional herb for medicinal purposes in eastern Asia. However, the anti-obesity effects of S. japonicafruit have not been explored. The aim of this study is to investigate the inhibition of adipocyte differentiation and adipogenesis by an ethanol extract of S. japonicafruit (EESF) in 3T3-L1 pre-adipocytes. Our results demonstrate that EESF suppressed the terminal differentiation of 3T3-L1 pre-adipocytes in a dose-dependent manner, as confirmed by a decrease in lipid droplet number and lipid content through Oil Red O staining. EESF significantly reduced the accumulation of cellular triglyceride, which was associated with a significant inhibition of the levels of pro-adipogenic transcription factors, including PPARγ, C/EBPα and C/EBPβ. In addition, EESF potentially down regulated the expression levels of adipocyte-specific proteins, including aP2 and leptin. In particular, EESF treatment effectively enhanced the activation of the AMPK signaling pathway; however, the co-treatment with compound C, an inhibitor of AMPK, significantly restored the EESF-induced inhibition of pro-adipogenic transcription factors and adipocyte-specific genes. These results indicate that EESF may exert an anti-obesity effect by controlling the AMPK signaling pathway, suggesting that the fruit extract of S. japonica may be a potential anti-obesity agent.

• Journal of the Korea Organic Resources Recycling Association
• /
• v.18 no.2
• /
• pp.76-83
• /
• 2010

We(Hansol EME Co. Ltd.) proceeded anaerobic digestion test for domestic food wastewater applying to two operating method for increasing of OLR. The methods are as follows. One was the rapidity operating method which was increasing the OLR continuously and rapidly and the other was the terraced operating method which was increasing the OLR having adaptation period for each step. As a result of this tests, the ratio of VFA/Alkalinity of the process was very unstable under the rapidity operating method then the volume of produced biogas was dramatically decreased. However the process was shown stable performance under the terraced operating method maintaining the ratio of VFA/Alkalinity less than 0.4. Also, the process was performing the biogas recovery of $0.8Nm^3/kgVS_{rem}/d$ and the VS removal ratio of 85%. T-RFLP analysis about the community of bacteria and methanogen is also conducted to check the change of the microbial community according to the methods of OLR increasing operation. The microbial community was changed by the methods of OLR increasing operation according to the result of T-RFLP analysis. Although the anaerobic digestion test was executed by same pilot plant, the reactivity and the tolerance of microbial community for surrounding environment could be considerably changed by the operating method for the process.

• Journal of Pharmaceutical Investigation
• /
• v.34 no.1
• /
• pp.49-55
• /
• 2004

To develop a aceclofenac soft capsule, four preparations with various solubilizers were prepared and their dissolution test was carried out. Among four preparations tested, a preparation with ethanolamine was selected as a formula of aceclofenac soft capsule (Clanza $S^{TM}$), since it showed the fastεst dissolution rate. Bioequivalence of aceclofenac tablet, $Airtal^{TM}$ (Dae-Woong Pharmaceutical Co., Ltd.) and aceclofenac soft capsule, Clanza $S^{TM}$ (Korea United Pharmaceutical Co., Ltd.) was evaluated according to the guideline of KA Fourteen normal male volunteers (age 20 - 25 years old) were divided into two groups and a randomized $2{\times}2$ cross-over study was employed. After oral administration of one tablet or capsule containing 100 mg of aceclofenac, blood was taken at predetermined time intervals and the concentration of aceclofenac in plasma was determined with an HPLC method under UV detector The pharmacokinetic parameters ($C_{max}$ and $AUC_t$) were calculated and ANOVA was utilized for the statistical analysis of parameters using logarithmetically transformed $AUC_t$, $C_{max}$ and $T_{max}$. The results showed that the differences in $AUC_t$, $C_{max}$ and $T_{max}$ between Aral tablet and Clanza soft capsule were 2.89%, 0.18% and 43.0%, respectively. There were no sequence effects between two formulations in these parameters. The 90% confidence intervals using logarithmically transformed data were within the acceptance range of log(0.8) to log(15) (e.g. log(0.81) -log(1.23) ad log(0.89) -log(1.4)) fo $AUC_t$ and $C_{max}$, respectively. Thus, the criteria of the KFDA guidelines for the equivalence was satisfied, indicating that Clanza $S^{TM}$ soft capsule is bioequivalent to$Airtal^{TM}$ tablet.

• Proceedings of the Korean Society of Crop Science Conference
• /
• 2017.06a
• /
• pp.10-10
• /
• 2017

Rice consumption has been continuously decreasing as the eating habits of Koreans have become westernized and diversified. The per capita annual rice consumption in Korea has dropped sharply from 136.4 kg in 1970 to 61.9 kg in 2016. The Korean government, therefore, has been trying to promote rice consumption by invigorating the processed food industry using rice flour. To facilitate the market for processed rice foods, it is essential to develop proper milling technology in terms of flour particle size and damaged starch content to produce high quality rice flour at competitive cost. Dry milling and wet milling are the two major processes used to produce rice flour. Although the dry milling process is relatively simple with a lower production cost, damaged starch content increases because of the high grain hardness of rice. In wet milling, the quality of rice flour is improved by reducing flour particle size as well as damaged starch content through soaking procedures. However, the production costs are high because of the additional expenses associated with the disposal of waste water, sterilization and drying of the wet flour. Recently developed technologies such as jet milling and cryogenic milling also require expensive investment and production. Therefore, developing new rice cultivars with dry milling adaptability as well as good processing properties is an important goal of rice breeding in Korea. 'Suweon 542' is a floury endosperm mutant line derived from sodium azide treatment on a high-yield, early maturing, and non-glutinous japonica rice cultivar, 'Namil'. Compared with the wild type, after dry milling process, the grain hardness of 'Suweon 542' was significantly lower because of its round and loosely packed starch granules. Also, the flour of 'Suweon 542' had significantly smaller particles and less damaged starch than 'Namil' and other rice cultivars and its particle size distribution was similar to a commercial wheat cultivar. Recently, through collaborations with nine universities and food companies, a total of 21 kinds of processed prototypes, using the dry milling flour of 'Suweon 542', were evaluated. In the production of major rice processing products, there was no significant quality difference between the flours prepared by wet milling and dry milling. Although the amount of water added to the dough was slightly increased, it was confirmed that the recipe applying the wet flour could be used without significant change. To efficiently transfer the floury endosperm characteristics of 'Suweon 542' to other commercial rice cultivars, it is essential to develop DNA marker tightly linked to the target gene. Association analysis using 70 genome-wide SSR markers and 94 F2 plants derived from 'Suweon 542'/'Milyang 23' showed that markers on chromosome 5 explained a large portion of the variation in floury grains percentage (FGP). Further analysis with an increased number of SSR markers revealed that the floury endosperm of 'Suweon 542' was directed by a major recessive locus, flo7(t), located in the 19.33-19.86 Mbp region of chromosome 5, with RM18639 explaining 92.2% of FGP variation in the F2 population. Through further physical mapping, a co-segregate and co-dominant DNA marker with the locus, flo7(t) was successfully developed, by which, thereby, breeding efficiency of rice cultivars having proper dry milling adaptability with high yield potential or useful functional materials would be improved. 'Suweon 542' maintained the early maturity of the wild type, Namil, which can be used in rice-wheat double cropping systems in Korea not only for improved arable land but also for sharing flour production facilities. In addition to the high susceptibility against major rice diseases, nevertheless, another possible drawback of 'Suweon 542' is the high rate of viviparous under prolonged rainfall during the harvesting season. To overcome susceptibility and vivipary of 'Suweon 542', the progeny lines, derived from the crosses 'Suweon 542' and 'Jopyeong', an early maturing rice cultivar with multiple resistance against rice blast, bacterial blight, and rice strip virus, and 'Heugjinju', a anthocyanin pigment containing black rice cultivar, were intensively evaluated. As the outputs, three dry milling suitable rice elite lines, 'Jeonju614', 'Jeonju615', and 'Jeonju616' were developed.

• The Korean Journal of Nuclear Medicine
• /
• v.30 no.4
• /
• pp.507-515
• /
• 1996

Background : Potassium channel opener (K-opener) opens ATP-sensitive K'-channel located at cell membrane and induces potassium efflux from cytosol, resulting in intracellular hyperpolarization. Newly synthesized K-opener is currently examined for pharmacologic potency by means of rubidium release test from smooth muscle strip pre-incubated with Rb-86. Since in-vivo behavior of thallium is similar to that of rubidium, we hypothesized that K-opener can alter T1-201 kinetics in vivo. Purpose : This study was prepared to investigate the effects of pinacidil (one of potent K-openers) on the T1-201 uptake and clearance in cultured myocyte, and in-vivo biodistribution in mice. Methods : Spontaneous contracting myocytes were prepared to imitate in-vivo condition from 20 hearts of 3-5 days old Sprague-Dawley rat and cultured for 3-5 days before use ($5{\times}10^5$ cells/ml). Pinacidil was dissolved in 10% DMSO solution at a final concentration of 100nM or l0uM and was co-incubated with T1-201 in HBSS buffer for 20-min to evaluate its effect on cellular T1-uptake, or challenged to cell preparation pre-incubated with T1-201 for washout study. Two, 40 or $100{\mu}g$ of pinacidil was injected intravenously into ICR mice at 10 min after $5{\mu}Ci$ T1-201 injection, and organ uptake and whole body retention rate were measured at different time points. Results : Co-incubation of pinacidil with T1-201 resulted in a decrease in T1-201 uptake into cultured myocyte by 1.6 to 2.5 times, depending on pinacidil concentration and activity of T1-201 used. Pinacidil enhanced T1-201 washout by 1.6-3.1 times from myocyte preparations pre-incubated with T1-201. Pinacidil treatment appears to be resulted in mild decreases in blood and liver activity in normal mice, in contrast, renal and cardiac uptake were mildly decreased in a dose dependent manner. Whole body retention ratios of T1-201 were lower at 24 hour after injection with $100{\mu}g$ of pinacidil than control. Conclusion : These results suggest that treatment with K-opener may affect the interpretation of T1-201 myocardial images, due to decreasing thallium accumulation and enhancing washout from myocardium.

• Korean Journal of Environment and Ecology
• /
• v.33 no.2
• /
• pp.216-227
• /
• 2019

The purpose of this study is to propose the rational mountain stream management strategy considering the natural conditions and social needs of the Republic of Korea. We reviewed domestic and overseas studies related to mountain streams, identified the study areas by text mining and co-word analysis using the VOSviewer program, and then analyzed the spatial and temporal study trends and topics of each study area. The results showed that domestic studies on mountain streams are still in an initial stage compared to overseas studies. Overseas studies on mountain streams can be classified into four groups: (i) habitat and species composition of fish and invertebrates, (ii) hydrological phenomena and nutrient migration, (iii) transport of sediment and organic materials and the relevant morphological changes by runoff flows, and (iv) plant species composition in mountain streams. Of these study subjects, domestic studies belonging to the (i) group mainly focused on macroinvertebrates while domestic studies belonging to the (iii) group regarded transport of sediment and organic materials as not the ecological disturbance but the source of sediment-related disasters. We then analyzed the rate of each research group to all papers by period and country. The results showed that the overseas studies belonging to (iii) and (iv) groups have increased with time, and the increase was mostly due to the studies in the United States, Brazil, Canada, and China. On the other hand, domestic studies belonging to (i) and (iii) groups increased somewhat with time, but there was a slight lack of correlation between the two subjects. Therefore, the hybridity studies to complement the shortage is necessary for the future.