• Journal of the Society of Naval Architects of Korea
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• v.55 no.5
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• pp.448-455
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• 2018

Glass wool is an eco-friendly materials that is manufactured through a continuous process by processing waste glass. This materials is low cost compared with another materials and has excellent thermal conductivity. For this reason, glass wool is installed as insulation system for LNG carriers and as insulation of building wall as well as various industries. The mechanism of insulation of glass wool is the conduction of the wool itself and convection by space between fibers. Therefore, in order to develop the enhanced thermal conductivity of glass wool is necessary to reduce its own conduction or to insert additional material after manufacturing as well as prevent convection. In this respect, many researchers have been actively studying to decrease thermal conductivity of polyurethane foam using by inserted glass wool or change the chemical component of glass wool. However, many research are aiming reduction of glass wool itself. This study focus on post-processing and inserted different materials; silica-aerogel, kevlar fiber 1mm, 6mm and glass bubble. Experimental results show that the thermal conductivity almost decreases with the addiction of glass bubble and silica aerogel.

• Restorative Dentistry and Endodontics
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• v.25 no.2
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• pp.180-192
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• 2000

One bottle system was recently developed in order to simplify the clinical skills and save chair time after continuous improvements on dentin bonding agents. There has been many studies to measure the bond strength of one bottle systems but no actual work has been done on micromorphologic study of resin-dentin interdiffusion zone after one bottle system application. To evaluate the bonding patterns of various commercially available one bottle systems to dentin, observation of resin-dentin interdiffusion zone under TEM was performed. Caries-free human third molars within one month of extractions were chosen for the experiments. The molars were sectioned 1mm above the cementoenamel junction and got rid of the root portions. Crown portions of the teeth were sectioned parallel to occlusal surface so that dentin discs of 1mm in thickness were remained. 7 one bottle systems and 1 two bottle system were applied according to manufacturer's instructions and followings were the results. 1. In every experimental groups, cross bandings of collagen fiber were distinguishable and tight bon dings between the bonding agents and dentin were observed. 2. Hybrid layer was clearly observed in ONE-STEP$^{(R)}$, Prime & Bond$^{(R)}$ 2.1, Syntac$^{(R)}$ SC, MAC-BOND II groups but it was not clear in Single Bond, D-Liner Dual PLUS, ONE COAT BOND groups. 3. Electron-density of hybrid layer was uniform in pattern in MAC-BOND II, Prime & Bond$^{(R)}$ 2.1 groups but not so uniform in ONE-STEP$^{(R)}$ group. 4. Electron-dense amorphous phase in most superior layer of the resin-dentin interdiffusion zone was characteristically observed in Single Bond, Syntac$^{(R)}$ SC, ONE COAT BOND groups. It can be concluded that bondings between the dentin bonding agents and dentin can be various in pattern according to their chemical compositions and the condition during applications.

• Polymer(Korea)
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• v.34 no.4
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• pp.321-325
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• 2010

Fibroin is a biopolymer available in large quantity from silk fiber and has a long history of use as a suture proving biocompatibility. In this report, fibroin microspheres has been fabricated for biomaterial applications. W/O emulsion of regenerated fibroin droplets in a continuous phase of decane with mixed surfactants was dried to facilitate fibroin gelation and the condensed fibroin microspheres were harvested. The ratio of mixed surfactants and their proportions to decane were determined to prepare a stable W/O emulsion. A spherical form of fibroin gels was obtained from the W/O emulsion agitated at 600 rpm. Scanning electron microscopy revealed that number average sizes of the fibroin microspheres were 21.6 and 8.5 ${\mu}m$ when dried under ambient conditions or under vacuum, respectively. Tomography of the spheres revealed that their internal structures are packed or hollowed. Hollow and hemispherical forms of microspheres were also prepared by using porogen.

• Investigative and Clinical Urology
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• v.59 no.6
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• pp.392-398
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• 2018

Purpose: To evaluate the initial experience and outcome of photo-selective vaporization of the prostate (PVP) for benign prostatic hyperplasia (BPH) in Pakistan with the use of a 980 nm diode laser. Materials and Methods: A prospective study was performed from November 2016 to December 2017. A total of 100 patients diagnosed with bladder outlet obstruction secondary to BPH who planned for PVP were enrolled in the study. PVP was carried out with a diode laser at 980 nm (Biolitec Diode 180W laser) in a continuous wave with a 600 nm (twister) fiber. Baseline characteristics and perioperative data were compared. Postoperative outcomes were evaluated by International Prostate Symptom Score (IPSS), post void residual (PVR) and maximum urinary flow rate (Qmax) at 3 and 6 months after surgery. Results: The mean age was $65.82{\pm}10.42$, mean prostate size was $67.35{\pm}16.42$, operative time was $55.85{\pm}18.01$ and total energy was $198.68{\pm}49.12kJ$. At 3 months and 6 months, significant improvements were noted (p<0.001) in IPSS $7.04{\pm}1.69$ (-18.92), Qmax $19.22{\pm}4.75mL/s$ (+13.09) and and PVR $18.89{\pm}5.39mL$ (-112.80). Most frequent problems were burning micturition (35%) and terminal dysuria (29%). No significant difference in postoperative hemoglobin was seen in patients who were on anti-platelet drugs. Conclusions: PVP with a diode laser is a safe and effective procedure for the treatment of BPH and is also safe in patients who are on anti-platelet agents.

• Biomedical Science Letters
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• v.27 no.3
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• pp.142-153
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• 2021

Liver fibrosis is a wound-healing response to chronic liver injury, which is caused by the continuous and excess deposition of extracellular matrix (ECM). The aim of this study is to investigate whether Uncaria rhynchophylla water extract (UR) can ameliorate thioacetamide (TAA)-induced liver fibrosis. The liver fibrosis model was induced on C57BL/6 mice by intraperitoneal injection with TAA three times a week for 8 weeks. UR (200 mg/kg) or silymarin (50 mg/kg) was administered orally daily for 8 weeks. Biochemical analyses including AST, ALT, MPO, and Ammonia levels were measured in serum. In the mice liver tissues, western blot and histological staining were analyzed. As a result, UR dramatically reduced the levels in serum AST, ALT, MPO, and Ammonia levels. UR treatment regulated NADPH oxidase factors expression, and antioxidant enzymes except for GPx-1/2 were significantly increased via Nrf2 activation. Furthermore, pro-inflammatory mediators, such as COX-2 and iNOS were markedly suppressed through the inhibition of NF-κB activation. Expressions of ECM-related protein including α-SMA and Collagen I were noticeably decreased. The additional histological evaluation confirmed that hepatocyte damage and collagenous fiber accumulation were attenuated. Taken together, these data suggest that UR possessed hepatoprotective effects in TAA-induced liver fibrosis via the NF-κB inactivation and Nrf2 activation. Therefore, UR may act as a potential therapeutic drug against liver fibrosis.

• Composites Research
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• v.35 no.1
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• pp.23-30
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• 2022

Polycarbosilane(PCS) is an important precursor for melt-spinning the silicon carbide(SiC) fibers and manufacturing ceramics. The PCS is a metal-organic polymer precursor capable of producing continuous SiC fibers having excellent performance such as high-temperature resistance and oxidation resistance. The SiC fibers are manufactured through melt-spinning, stabilization, and heat treatment processes using the PCS manufactured by synthesis, purification, and control of the molecular structure. In this paper, we analyzed the effect of purification of unreacted substances and low molecular weight through solvent treatment of PCS and the effect of heat treatment at various temperatures change the polymerization and network rearrangement of PCS. Especially, we investigated the complex viscosity and structural arrangement of PCS precursors according to solvent treatment and heat treatment through the rheological properties.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.30 no.2A
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• pp.161-168
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• 2010

The bonded tendon was adopted to the reactor building of some operating nuclear power plants in Korea and the assessment of the effective prestress force on the bonded tendon is being issued as an important pending problem for continuous operation beyond their design life. The sensitivity analysis of various parameters was carried out to evaluate the effective prestress force using the system identification technique and the optimal parameters were determined for SI technique in this study. The 1/5 scaled post-tensioned concrete beams with the bonded tendon type were manufactured and in order to investigate the relationship of the natural frequency and the displacement to the effective prestress force, impact test, SIMO sine sweep test and bending test using the optical fiber sensor and the compact displacement transducer were carried out. As a result of tests, both the natural frequency and the displacement show the good relationship with the effective prestress force and both parameters are available for the SI technique to estimate the effective prestress force.

• Korean Journal of Environmental Agriculture
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• v.32 no.4
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• pp.323-331
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• 2013

BACKGROUND: Liquid pig manure(LPM) is a useful resource if it is sufficiently fermented and utilized in the agriculture; it provides nutrients to soils, circulates organic materials and replaces chemical fertilizers(CF) with reasonable costs. Currently, there are not many trials in paddy field to continuously cultivate the crops in winter and summer season using LPM. METHODS AND RESULTS: When cultivating winter forage crops (Whole-crop-barley(WCB), Rye, Triticale, Italian ryegrass(IRG)) and summer feed corns in the rice field, CF was treated with $N-P_2O_5-K_2O$(winter forage crops: 120-100-100kg/ha, summer feed corn: 200-150-150 kg/ha), and subsequently, growth, yields, feed values and chemical properties of soil were investigated. LPM-applied areas in both winter and summer forage crops showed higher plant lengths and tillers than those of CF-applied areas, but the yield in CF-applied areas was higher than that of LPM-applied areas under continuous application of 2 years. Crude protein, neutral detergent fiber(NDF), acid detergent fiber(ADF) and total digestion nutrient(TDN) in feed values showed almost similar results between LPM and CF-applied areas. EC, organic matter, available phosphate and exchangeable cations of soils after the experiment increased in LPM applied areas, and especially, the contents of available phosphate and exchangeable sodium were high. CONCLUSION(S): Considering the above results, it was concluded that if LPM are properly utilized for continuous winter and summer cultivation of feed crops at paddy field, the cultivation costs could be decreased and be helpful to the stable production of domestic feeds.

• Journal of The Korean Society of Grassland and Forage Science
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• v.38 no.1
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• pp.61-73
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• 2018

The objective of this study was to investigate the suitable method for rapid establishment of grassland according to forage species, mixed pastures and installation of mesh at 35 degree angle of cutting area in the middle region of Korea. In agronomic characteristics after wintering, vegetation coverage of Tall fescue(TF) was 74% in monoculture, which was the highest among 3 forage crops. Meanwhile average vegetation coverages of monoculture and mixed pasture were 67 and 92% in treated of mesh, which were 4 and 18% higher than untreated of mesh, respectively. In botanical composition, TF of monoculture and Orchardgrass(OG) and TF oriented mixed were indicated over 94% forage coverage. Meanwhile forage coverages Kentucky bluegrass(KBG) and Red top(RT) of monoculture and Perennial ryegrass(PRG) oriented mixture were 89, 81 and 92% in treated of mesh, which were 7, 6 and 5% higher than untreated of mesh, respectively. In forage productivity, dry matter yield(DMY) of TF(12,537kg/ha) and KBG(11,897kg/ha) of monoculture were significant(p<0.05) higher than RT(9,604kg/ha). Meanwhile DMY of OG(12,227kg/ha), TF(12,823kg/ha) and PRG(11,871kg/ha) oriented mixed were not significant difference(p>0.05). In forage quality of monoculture, in the first year, crude protein of KBG was 13.6%, which was the highest among 3 forage species. Also neutral detergent fiber(NDF) of TF was 56.5%, which was the lowest among 3 forage species. In mixed pasture, in the second year, NDF and acid detergent fiber of PRG oriented mixed were 56.5 and 34.3%, respectively, which was the lowest among 3 mixed pasture. In conclusion, forage species TF was more suitable on initial rootage and continuous forage coverage, OG and TF oriented mixed were more suitable on continuous forage coverage. Also the installation of mesh showed positive effects on initial rootage and maintain forage ratio.

• Journal of the Korean Society of Food Science and Nutrition
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• v.35 no.9
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• pp.1207-1214
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• 2006

The purposes of this study were to determine the estimated dietary fiber (DF) intakes per capita/day of Korean as of 2001 by age groups and sex, and to analyze the major food sources of DF using the data on per capita consumption of each food reported in the 2001 Reports of Korean National Nutrition Survey and the newly-established DF database. The mean daily intakes of DF of Korean increased with increasing age until 49 years and thereafter decreased with aging. The intakes of DF/1,000 kcal increased with increasing age until 64 years and thereafter decreased with aging. On the average, the Korean people under age of 49 did not meet adequate intake (AI) of DF (12 g/1,000 kcal) in Dietary Reference Intakes (DRI) for the Koreans. The male people less satisfied the AI than the female did. The major food groups contributed to DF intakes of Korean adults were high in the order of vegetables, cereals, fruits, seasonings, legumes and seaweeds. Regardless of age and sex, vegetables, cereals and fruits were three major sources of DF for Koreans who obtained approximately 75% of DF from those sources. It has been shown that rice was the first single food source of DF intake for the age groups less than 12 years, however Kimchi was the first major source for all the age groups over 12 years. The infant and elderly groups obtained more DF from 10 major single food sources than the other age groups did. The results of the study revealed that the present levels of DF intakes of Korean in all age groups except the elderly group are insufficient to meet the AI for DF. Therefore the beneficial effects of DF on health and the increased consumption of DF from the variety of food sources should be emphasized through the continuous nutritional education.