• The Korean Journal of Urological Oncology
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• 제15권3호
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• pp.178-186
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• 2017

Purpose: Poloxamer 407 (P407) thermo-sensitive hydrogel formulations were developed to enhance the retention time in the urinary bladder after intravesical instillation. Materials and Methods: P407 hydrogels (P407Gels) containing 0.2 w/w% fluorescein isothiocyanate dextran (FD, MW 4 kDa) as a fluorescent probe were prepared by the cold method with different concentrations of the polymer (20, 25, and 30 w/w%). The gel-forming capacities were characterized in terms of gelation temperature (G-Temp), gelation time (G-Time), and gel duration (G-Dur). Homogenous dispersion of the probe throughout the hydrogel was observed by using fluorescence microscopy. The in vitro bladder simulation model was established to evaluate the retention and drug release properties. P407Gels in the solution state were administered to nude mice via urinary instillation, and the in vivo retention behavior of P407Gels was visualized by using an in vivo imaging system (IVIS). Results: P407Gels showed a thermo-reversible phase transition at $4^{\circ}C$ (refrigerated; sol) and $37^{\circ}C$ (body temperature; gel). The G-Temp, G-Time, and G-Dur of FD-free P407Gels were approximately $10^{\circ}C-20^{\circ}C$, 12-30 seconds, and 12-35 hours, respectively, and were not altered by the addition of FD. Fluorescence imaging showed that FD was spread homogenously in the gelled P407 solution. In a bladder simulation model, even after repeated periodic filling-emptying cycles, the hydrogel formulation displayed excellent retention with continuous release of the probe over 8 hours. The FD release from P407Gels and the erosion of the gel, both of which followed zero-order kinetics, had a linear relationship ($r^2=0.988$). IVIS demonstrated that the intravesical retention time of P407Gels was over 4 hours, which was longer than that of the FD solution (<1 hour), even though periodic urination occurred in the mice. Conclusions: FD release from P407Gels was erosion-controlled. P407Gels represent a promising system to enhance intravesical retention with extended drug delivery.

• Korean Journal of Remote Sensing
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• v.34 no.6_3
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• pp.1427-1443
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• 2018

Object-based image analysis (OBIA) allows higher computation efficiency and usability of information inherent in the image, as it reduces the complexity of the image while maintaining the image properties. Superpixel methods oversegment the image with a smaller image unit than an ordinary object segment and well preserve the edges of the image. SLIC (Simple linear iterative clustering) is known for outperforming the previous superpixel methods with high image segmentation quality. Although the input parameter for SLIC, number of superpixels has considerable influence on image segmentation results, impact analysis for SLIC parameter has not been investigated enough. In this study, we performed optimal parameter analysis and evaluation of change detection for SLIC-based superpixel techniques using KOMPSAT data. Forsuperpixel generation, three superpixel methods (SLIC; SLIC0, zero parameter version of SLIC; SNIC, simple non-iterative clustering) were used with superpixel sizes in ranges of $5{\times}5$ (pixels) to $50{\times}50$ (pixels). Then, the image segmentation results were analyzed for how well they preserve the edges of the change detection reference data. Based on the optimal parameter analysis, image segmentation boundaries were obtained from difference image of the bi-temporal images. Then, DBSCAN (Density-based spatial clustering of applications with noise) was applied to cluster the superpixels to a certain size of objects for change detection. The changes of features were detected for each superpixel and compared with reference data for evaluation. From the change detection results, it proved that better change detection can be achieved even with bigger superpixel size if the superpixels were generated with high regularity of size and shape.

• The Journal of the Convergence on Culture Technology
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• v.8 no.3
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• pp.143-148
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• 2022

The subject of this paper is the practical examples of technoculture that critically thinks network technology, a strong material foundation in the era of data capitalism in the 21st century, and appropriates its socio-cultural metaphor as an artistic potential. In order to analyze its alternatives and the meaning of cultural politics, this paper examines the properties and influence of data capitalism after the 2008 global financial crisis, and the cultural and artistic context formed by its reaction. The first case considered in this paper, Furtherfield's workshop, provided a useful example of how citizens can participate in social change through learning and education in which art and technology are interrelated. The second case, Greek hackerspace HSGR, developed network technology as a tool to overcome the crisis by proposing a new progressive cultural commons due to Greece's financial crisis caused by the global financial crisis and a decrease in the state's creative support. The third case, Paolo Cirio's project, promoted a critical citizenship towards the state and community systems as dominant types of social governance. These technoculture cases can be evaluated as efforts to combine and rediscover progressive political ideology and its artistic realization tradition in the context of cultural politics, paying attention to the possibility of signifying practices of network technology that dominates the contemporary economic system.

• Food Science and Preservation
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• v.30 no.5
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• pp.896-904
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• 2023

The texturization characteristics of textured vegetable protein (TVP) were investigated based on the extent of soybean decoating during the pretreatment of defatted soybean flour used for TVP. The raw materials for TVP consisted of 50% defatted soybean flour, 30% gluten, and 20% corn starch. The weight ratios of soybean seed coat to soybean flour were 9%, 6%, 3%, and zero. Extrusion was performed using an extruder equipped with a cooling die, maintaining a barrel temperature of 190℃ and screw speed of 250 rpm, Water was injected at a rate of 9 rpm using a metering pump. Regarding the textures of the extruded TVPs produced from defatted soybean flour, an increase in the soybean seed coat content led to a decrease in the apparent fibrous structural layer and an increase in hardness. However, there were no significant changes in elasticity and cohesion. Moreover, as the soybean seed coat content increased, the pH of TVPs decreased. A higher soybean seed coat content also tended to lower the moisture content, increasing water absorption, solids elution, and turbidity. These results suggest that an increased seed coat content reduces the proportion of protein, and the fibers present in the seed coats prevent texturization.

• International Journal of Highway Engineering
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• v.8 no.2 s.28
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• pp.63-74
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• 2006

During the construction of circular underground pipe, the non-proper compaction along the pipe and the decrease of compaction efficiency have been the main problems to induce the failure of underground pipe or facility. The use of CLSM (controlled low strength materials) should be one of the possible applications to overcome those problems. In this research, the full-scaled field test and the numeric analysis using PENTAGON-3D FEM program were carried out for three different cases on the change of backfill materials, including the common sand, the soil from construction site, and the CLSM. From the full-scaled test in field, the use of in-situ CLSM as backfill materials reduced the vertical and lateral deformation of the pipe, as well as the deformation of the ground surface. The main reason for reducing the deformation would be the characteristics of the CLSM, especially self-leveling and self-hardening properties. The measured earth pressure at the surround of the corrugated pipe using the CLSM backfills was the smaller than the other cases, and the absolute value was almost zero. Judging from the full-scaled field test and FEM analysis, the use of CLSM as backfill materials should be one of the best choices reducing the failure of the underground pipes.

• Journal of the Korean Magnetics Society
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• v.13 no.5
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• pp.187-192
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• 2003

The magnetic and thermal properties of NiFe/[IrMn-Mn]/CoFe with Mn additions have been studied. As-deposited CoFe pinned layers with [IrMn-Mn]layer had dominantly larger exchange biasing field ( $H_{ex}$) and blocking temperature ( $T_{b}$) than those with pure I $r_{22}$M $n_{78}$ used. The $H_{ex}$ and $T_{b}$ improved with 76.8-78.1 vol% Mn, but those of the NiFe/IrMn/CoFe dropped considerably with more addition of 0.6 vol % Mn. The average x-ray diffraction peak ratios of fcc [(111)CoFe, NiFe]/(111)IrM $n_3$ textures for the Mn inserted total vol of 75.5, 77.5, and 79.3% were about 1.4, 0.8, and 0.6, respectively. For the sample without Mn inserted layer, the $H_{ex}$ between IrMn and CoFe layers was almost zero, but it increased to 100 Oe after annealing of 250 $^{\circ}C$. For as-grown two multilayers samples with ultra-thin Mn layers of 77.5 and 78.7 vol %, the $H_{ex}$s were 259 and 150 Oe, respectively. In case of IrMn with 77.5 vol% Mn, the $H_{ex}$ was increased up to 475 Oe at 350 $^{\circ}C$ but decreased to 200 Oe at 450 $^{\circ}C$, respectively. The magnetic properties and thermal stabilities of NiFe/[IrMn-Mn]/CoFe multilayer were enhanced with Mn additions. In applications where higher $H_{ex}$ and $T_{b}$ are required, proper contents of Mn can be used. be used. used.

• New Physics: Sae Mulli
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• v.68 no.12
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• pp.1293-1301
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• 2018

The basic magnetic properties of commercially available High-$T_c$ Superconductor (HTS) GdBCO-coated conductor (GdBCO-CCs) were investigated by using physical property measurement system-vibrating sample magnetometer (PPMS-VSM). From the zero-field-cooled (ZFC) m(T) curve, the $T_c$ was found to be ~93 K. After removing the background m(H) data, we obtained both the net m(H) data and the ${\Delta}m_{irr}$. The $H_{irr}(T)$ coincided very well with the power-law relation $H_{irr}=H_{irr}(0)(1-T/T_c)^n$ with $$n{\sim_=}1.19$$. The magnetic flux behavior was investigated by using the ${\delta}$ values in the relationship $J_c{\propto}{\Delta}m_{irr}{\propto}H^{-{\delta}}$. A ${\delta}{\approx}0$ region denoting an independent magnetic flux pinning effect, a ${\delta}{\approx}0.6{\sim}1.2$ region representing a collective flux pinning effect due to the interaction, and a ${\delta}{\gg}2$ region representing freely moving magnetic fluxes caused by the Lorentz force were observed. The boundary line between ${\delta}{\approx}0$ and ${\delta}{\approx}0.6{\sim}1.2$ is denoted by a $H_1$, and the one between ${\delta}{\approx}0.6{\sim}1.2$ and ${\delta}{\gg}2$ is denoted by a $H_2$. The ${\delta}(T)$ was obtained in the region of $H_1$ < H < $H_2$. As the temperature was decreased, the ${\delta}$ value gradually decreased.

• Economic and Environmental Geology
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• v.54 no.6
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• pp.709-716
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• 2021

In this study, an adsorbent prepared by natural drying of iron hydroxide-based sludge collected from settling basin at a mine drainage treatment facility located in Gangneung, Gangwon-do was used to remove fluoride in an artificial fluoride solution and mine drainage, and the adsorption characteristics of the adsorbent were investigated. As a result of analyzing the chemical composition, mineralogical properties, and specific surface area of the adsorbent used in the experiment, iron oxide (Fe₂O₃) occupies 79.2 wt.% as the main constituent, and a peak related to calcite (CaCO₃) in the crystal structure analysis was analyzed. It was also identified that an irregular surface and a specific surface area of 216.78 m²·g^-1. In the indoor batch-type experiment, the effect of changes in reaction time, pH, initial fluoride concentration and temperature on the change in adsorption amount was analyzed. The adsorption of fluoride showed an adsorption amount of 3.85 mg·g^-1 16 hours after the start of the reaction, and the increase rate of the adsorption amount gradually decreased. Also, as the pH increased, the amount of fluoride adsorption decreased, and in particular, the amount of fluoride adsorption decreased rapidly around pH 5.5, the point of zero charge at which the surface charge of the adsorbent changes. Meanwhile, the results of the isotherm adsorption experiment were applied to the Langmuir and Freundlich isotherm adsorption models to infer the fluoride adsorption mechanism of the used adsorbent. To understand the thermodynamic properties of the adsorbent using the Van't Hoff equation, thermodynamic constants 𝚫H° and 𝚫G° were calculated using the adsorption amount information obtained by increasing the temperature from 25℃ to 65℃ to determine the adsorption characteristics of the adsorbent. Finally, the adsorbent was applied to the mine drainage having a fluoride concentration of about 12.8 mg·L^-1, and the fluoride removal rate was about 50%.

• Journal of the Microelectronics and Packaging Society
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• v.28 no.4
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• pp.11-18
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• 2021

A novel microwave dielectric composite material for ultra-low temperature co-fired ceramics (ULTCC) with (1-x)BaWO₄-xBaV₂O₆ (x=0.54~0.85) composition was prepared by firing a mixture of BaWO₄ and BaV₂O₆. Shrinkage tests showed that the ceramic composite begins to densify at a temperature as low as 550℃ and can be sintered at 650℃ with 98% of relative density under the influence of BaV₂O₆. X-ray diffraction analysis showed that BaWO₄ and BaV₂O₆ coexisted and no secondary phase was detected in the sintered bodies, implying good chemical compatibility between the two phases. Near-zero temperature coefficients of the resonant frequency (𝛕_f) could be achieved by controlling the relative content of the two phases, due to their positive and negative 𝛕_f values, respectively. With increasing BaV₂O₆ (x from 0.53 to 0.85), the 𝛕_f value of the composites increased from -7.54 to 14.49 ppm/℃, ε_r increased from 10.08 to 11.17 and the quality factor (Q×f value) decreased from 47,661 to 37,131 GHz. The best microwave dielectric properties were obtained for x=0.6 samples with ε_r=10.4, Q×f=44,090 GHz, and 𝛕_f=-2.38 ppm/℃. Chemical compatibility experiments showed the developed composites are compatible with aluminum electrode during co-firing process.

• Korean Journal of Soil Science and Fertilizer
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• v.40 no.4
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• pp.269-273
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• 2007

Occurrence of malodor could cause adverse impacts on human health and increase public interest. Therefore, scientific methods to decrease odor is required. Endeavor to decrease odor from compost however has not fully been successful. The purpose of this research is assessment of some amendments to reduce $NH_3$ from immature composts. Calcium hydroxide was applied to composts due to it's characteristics to increase pH. Activated carbon and zerovalent iron (ZVI) were selected because of their adsorption properties. The research results were as follows: Calcium hydroxide, activated carbon, zerovalent iron increased the composting temperature above $60^{\circ}C$. The addition of calcium hydroxide, activated carbon, and ZVI to compastry process increased pH 8.6 - 8.8 from $1^{st}$ day to $14^{th}$ day. During the 14 days of composting, addition of calcium hydroxide, activated carbon and ZVI changed EC from $2.15-0.66dS\;m^{-1}$, $1.48-1.11dS\;m^{-1}$, respectively and $1.77-0.68dS\;m^{-1}$. The difference in EC of the compost was due to irregularities of samples. Organic matter in the compost decreased through out theexcept control. The $NH_4-N/NO_3-N$ ratio of all experimental compost increased through the process. The addition of activated carbon, calcium hydroxide and ZVI decreased $NH_3$ from 0.1ppm, 0.7ppm and 1.7ppm more than the control (pig manure and sawdust), 9.3ppm, in 30 days of composting. In conclusion, odor from prematured compost decreased by addition of chemicals like calcium hydroxide, activated carbon, zerovalent iron. Moreover, use of these $NH_3$ reducers alone or together combined at different periods of composting etc. could decrease $NH_3$.