• 보존과학연구
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• s.20
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• pp.81-90
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• 1999

We performed the non-destructive analysis of objects excavated at the Tomb of Mich’un-ri in Ch’ung-won. We analysed components using of Energy Dispersive X-Ray Micro-Fluorescence Analyzer. Glass bead inlaid with silver was classified as K2O-CaO-SiO2 type of glass. Purity of silver inlaid in the surface was verified above 97%.All small ear-ring were made by rolling up gold broad to a bronze wick. The composition ratio of Au : Ag has significantly higher 87 : 11 than bigear-ring. As a result of composition analysis of a welded part with big ear-ring, it contained the more Cu, Hg contents and the less Au, Ag contents than the surface of big ear-ring.

• International Journal of Highway Engineering
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• v.14 no.3
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• pp.131-140
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• 2012

Lane markings such as edgelines, centerlines, and lines that delineate lanes generally provide drivers with the various information for safe driving. Drivers can easily recognize the lane markings through the color differences between the markings and road surfaces during the daytime. However, it is a bit difficult for drivers to perceive them during the nighttime due to the lack of artificial lights. Although the glass beads with the 1.5-refractive index have been used to improve the visibility of the lane markings during the nighttime, it is still difficult for drivers to recognize the lane markings properly, especially during the rainy nighttime, which may often lead to traffic accidents. To improve the retroreflectivity and visibility of the lane markings during the rainy nighttime, the high refractive beads with the 2.4-refractive index are essentially required, but they do not work appropriately during the dry nighttime. Thus, the mixed materials with the 1.5, 1.9, and 2.4-refractive beads should be considered for the satisfactory implementation of the lane markings. This study reveals the best mixing rates of the beads by conducting benefit-cost analysis under various weather conditions in Korea. The analysis results show that the lane markings with the 100% of the 2.4-refractive beads provide the highest visibility of lane markings regardless of the roadway conditions, but the benefit-cost (B/C) ratio of the bead mixture is merely 0.46. The best mixing rate of the beads, from the highest B/C ratio viewpoint, was identified as the mixture with a 80% of 1.5-refractive beads and a 20% of 2.4-refractive beads. Some limitations and future research agenda have also been discussed.

• 보존과학연구
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• s.32
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• pp.113-121
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• 2011

Four glass beads from Hakso-ri site, O'chang were analyzed for thirteen oxides with SEM/EDS and lead isotope ratios with TIMS respectively. These samples were classified to potash glass system($K_2O-CaO-SiO_2$) with HCLA(High CaO, Low $Al_2O_3$). However three samples with above 4% for lead could be classified to potash-lead ($K_2O-PbO-CaO-SiO_2$)glass system and it seemed that coloring agent for greenish blue was Cu. Lead isotope ratio data for four samples did not make a group but scattered to the space respectively. It needs more study for compositions and lead iosotope data of potash-lead glasses with regions and ages.

• Journal of the Korean Recycled Construction Resources Institute
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• v.10 no.1
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• pp.74-79
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• 2022

In this study, the effect of a sudden decrease in internal humidity and a decrease in hydration level due to the tight internal structure of high-strength concrete and cement composites was investigated. To verify the change in the internal Si hydration, waste glass foam beads were used as a lightweight aggregate, and the internal unreacted hydrate reduction and hydrate formation tendency were identified over the mid- to long-term. Waste glass foam beads were mixed with 5, 10, and 20 %, and were used by pre-wetting. As the mixing rate of the waste glass foamed beads increased, the strength showed a tendency to decrease. In addition, when the mixing amount of pre-wetted waste glass foam beads increases inside through XRD analysis, TGA analysis, and Si NMR analysis, it is judged that the hydration degree of internal Si is different because moisture is supplied to the paste.

• Journal of Microbiology and Biotechnology
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• v.25 no.12
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• pp.2058-2071
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• 2015

A comparative study was conducted to evaluate precision and accuracy in controlling the temperature dependence of encapsulated microbial time-temperature integrators (TTIs) developed using two different emulsification techniques. Weissela cibaria CIFP 009 cells, immobilized within 2% Na-alginate gel microbeads using homogenization (5,000, 7,000, and 10,000 rpm) and Shirasu porous glass (SPG) membrane technologies (10 μm), were applied to microbial TTIs. The prepared micobeads were characterized with respect to their size, size distribution, shape and morphology, entrapment efficiency, and bead production yield. Additionally, fermentation process parameters including growth rate were investigated. The TTI responses (changes in pH and titratable acidity (TA)) were evaluated as a function of temperature (20℃, 25℃, and 30℃). In comparison with conventional methods, SPG membrane technology was able not only to produce highly uniform, small-sized beads with the narrowest size distribution, but also the bead production yield was found to be nearly 3.0 to 4.5 times higher. However, among the TTIs produced using the homogenization technique, poor linearity (R²) in terms of TA was observed for the 5,000 and 7,000 rpm treatments. Consequently, microbeads produced by the SPG membrane and by homogenization at 10,000 rpm were selected for adjusting the temperature dependence. The E_a values of TTIs containing 0.5, 1.0, and 1.5 g microbeads, prepared by SPG membrane and conventional methods, were estimated to be 86.0, 83.5, and 76.6 kJ/mol, and 85.5, 73.5, and 62.2 kJ/mol, respectively. Therefore, microbial TTIs developed using SPG membrane technology are much more efficient in controlling temperature dependence.

• KSBB Journal
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• v.4 no.2
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• pp.87-93
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• 1989

To develop high dfficiency-low energy consumption attrition coupled bioreactor for enhanced enzymatic hyerolysis of insoluble biomass, a tumbling drum type bioreactor was installed, and its efficiency was evaluated. The effects of drum structure and poerational conditions were investigated. The optimal saccharification at 3L drum was obtained at 8 baffled drum, drum diameter to baffle height ratio of 1:0.05, 100rpm, and addition of 600g of 3mm glass bead per liter. The consumed power for rolling of drum and energy consumption for half digestion of cellulose were measured, and compared with enhanced rate and yield to predict the economic prospect of the process. The tumbling drum type bioreactor seems to have appropriated structure for industrial scale operation, and further investigation for scale-up need to be conducted.

• Clean Technology
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• v.17 no.3
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• pp.209-214
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• 2011

The effects of inlet gas velocity (0.26-0.31 m/s), inlet gas temperature (315-353 K) and the mass ratio (0.1-0.4) of fine polymer (crosslinked poly methyl methacrylate beads) to inert medium particles on the drying rate of fine polymer in a 0.15 m-ID ${\times}$ 1.0 m-high inert medium fluidized bed dryer have been investigated. Crosslinked PMMA beads of 20 ${\mu}m$ (group C) were used as fine polymer, and glass beads of 590 ${\mu}m$ (group B) were used as the inert medium. The drying rate increases with increasing inlet gas temperature and velocity. However, the drying rate decreases slightly as the mass ratio of fine polymer to inert medium particles increases. The particle size distribution of dried fine polymers was mono distribution.

• Applied Chemistry for Engineering
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• v.1 no.2
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• pp.133-139
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• 1990

Methacrylate functional silanes with different methylene spacer groups have been synthesized and the orientation effect and absorption behavior of these silane coupling agent were investigated by Fourier transform infrared spectroscopy(FT-IR). The mechanical properties of glass bead/polyester composites are found to be dependent on the spacer group of treated silane coupling agent. The absorption rate of the silane coupling agent onto the fumed silica surface decreases with increasing the number of the methylene spacer in methacrylate functional silanes. Silane molecules containing long spacer groups are adsorbed onto silica slightly bowed with respect to the substrate surface. The relationship between silane molecular structure and mechanical properties of polymer composites is also investigated in order to improve hot/wet properties of glass fiber/polyester composites.

• Bulletin of the Korean Chemical Society
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• v.25 no.9
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• pp.1366-1370
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• 2004

Controlled pore glass bead was modified with bovine serum albumin (BSA), and glutathione (GSH) was immobilized through three kinds of linkers on top of BSA. Bis(3-sulfo-N-hydroxysuccinimide suberate) sodium salt $(BS^3)$, N-hydroxysuccinimide 3-(2-pyridyldithio)propionate (SPDP), or N-hydroxysuccinimide 4-maleimidobutyrate (GMBS) was introduced into the BSA-bound matrix. Subsequently, GSH was immobilized by addition of thiol side chain into the maleimido moiety, replacing a disulfide group, or formation of an amide group upon releasing 3-sulfo-N-hydroxysuccimide group. It was observed that conjugation methodology played a critical role for activity of the immobilized GSH. SDS-PAGE chromatogram showed that the matrix of glutathione immobilized on BSA through GMBS manifested high selectivity towards glutathione-S-transferase (GST) in cell lysate.

• Proceedings of the Korean Vacuum Society Conference
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• 2014.02a
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• pp.402.1-402.1
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• 2014

Photonic force microscopy (PFM) is an optical tweezers-based scanning probe microscopy, which measures the forces in the range of fN to pN. The low stiffness leads proper to measure single molecular interaction. We introduce a novel photonic force microscopy to stably map various chemical properties as well as topographic information, utilizing weak molecular bond between probe and object's surface. First, we installed stable optical tweezers instrument, where an IR laser with 1064 nm wavelength was used as trapping source to reduce damage to biological sample. To manipulate trapped material, electric driven two-axis mirrors were used for x, y directional probe scanning and a piezo stage for z directional probe scanning. For resolution test, probe scans with vertical direction repeatedly at the same lateral position, where the vertical resolution is ~25 nm. To obtain the topography of surface which is etched glass, trapped bead scans 3-dimensionally and measures the contact position in each cycle. To acquire the chemical mapping, we design the DNA oligonucleotide pairs combining as a zipping structure, where one is attached at the surface of bead and other is arranged on surface. We measured the rupture force of molecular bonding to investigate chemical properties on the surface with various loading rate. We expect this system can realize a high-resolution multi-functional imaging technique able to acquire topographic map of objects and to distinguish difference of chemical properties between these objects simultaneously.