• Journal of the Korea Institute of Building Construction
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• v.23 no.2
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• pp.153-164
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• 2023

The objective of this study is to examine the removal rate of air pollutants, specifically sulfur oxides (SO_x) and nitrogen oxides(NO_x), using concrete permeable blocks containing zeolite beads coated with materials capable of eliminating these pollutants. Titanium dioxide(TiO₂) powder and coconut shell powder were utilized for the removal of SO_x and NO_x and were applied as coatings on the zeolite beads. Concrete permeable block specimens embedded with the coated zeolite beads were produced using an actual factory production line. Test results demonstrated that the concrete permeable block containing zeolite beads coated with coconut shell powder in the surface layer achieved SO_x and NO_x removal rates of 12.5% and 99%, respectively, exhibiting superior performance compared to other blocks. Additionally, the flexural strength and slip resistance were 5.3MPa and 65BPN or higher, respectively, satisfying the requirements specified in KS F 4419 and KS F 4561. Conversely, the permeability coefficient exhibited low permeability, with grades 2 and 3 before and after contaminant pollution, according to the standard for 'design, construction, and maintenance of pavement using permeable block'. In conclusion, incorporating zeolite beads coated with coconut shell powder in the surface layer enables simultaneous removal of SO_x and NO_x, irrespective of ultraviolet rays, while maintaining adequate flexural strength and slip resistance. However, the permeability is significantly reduced, necessitating further improvements.

• Journal of Sensor Science and Technology
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• v.13 no.1
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• pp.56-65
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• 2004

In this paper, we proposed the detection algorithm of microcalcification based on region growing method with contrast and edge sharpness in digital X-ray mammographic images. We extracted the local maximum pixel and watershed regions by using watershed algorithm. Then, we used the mean slope between local maximum and neighborhood pixels to extract microcalcification candidate pixels among local maximum pixels. During increasing threshold value to grow microcalcification region, at the maximum threshold value of the contrast and edge sharpness, the microcalcification area is decided. The regions of which area of grown candidate microcalfication region is larger than that of watershed region are excluded from microcalcifications. We showed the diagnosis algorithm can be used to aid diagnostic-radiologist in the early detection breast cancer.

• Korean Journal of Food Science and Technology
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• v.48 no.5
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• pp.399-404
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• 2016

The applicability of photostimulated-luminescence (PSL) and thermoluminescence (TL) for the detection of 12 food materials (potato, onion, garlic, dried pumpkin, black mushroom, black soybean, Cheongkukjang powder, sea mustard, pepper powder, Ramyun soup, corn tea, and green tea powder) irradiated with an electron beam, gamma ray, and X ray at a range of 0.15 to 10 kGy was investigated. For PSL, negative results (less than 700 photon counts (PCs)) were observed from non-irradiated foods while the irradiated foods showed intermediate (879 to 2,414 PCs) and/or positive (19,951 to 65,919,035 PCs) values. In all irradiated samples, the maximum peak of the TL glow curve was observed between 150 and $250^{\circ}C$. Our findings demonstrate the successful application of PSL and TL to determine whether food items were irradiated or not. However, there were no significant differences among the radiation sources.

• Journal of Animal Science and Technology
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• v.49 no.5
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• pp.633-638
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• 2007

This study was conducted to determine the protein requirement level in growing Jindo dog through nitrogen balance experiment. Twelve female dogs aged 18～20 weeks old were allotted one of 3 dietary treatments containing 21, 23 and 25% of crude protein. Average daily gain of dogs fed experimental diets containing 21, 23 and 25% of crude protein were 65.42, 79.58 and 99.17g/d, respectively, and there was a significant difference between 21 and 25% of crude protein treatments(p<0.05). Retained nitrogen were calculated 0.74, 0.96 and 1.31g/kgBW.75/d for dogs fed diets containing 21, 23 and 25% of crude protein, respectively, and were significantly higher(p<0.05) in dogs fed 25% of crude protein diet then those of other dogs. A quadratic regression equation was calculated between nitrogen intake(x) and nitrogen retention(y); y=-2.519x2+12.79x-14.79, and it was found a significantly(p<0.05) higher regression coefficient of 0.782. From the above equation, it was estimated maintenance requirement of crude protein for growing Jindo dog is 11.25g/kg BW.75/d.

• Korean Journal of Materials Research
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• v.7 no.6
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• pp.536-544
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• 1997

본연구는 45 BaO-20B$_{2}$O$_{3}$-35Fe$_{2}$o$_{3}$(wt%)의 조성의 유리에 핵형성제로서 TiO$_{2}$또는 ZrO$_{2}$를 첨가한 조성에서는 barium ferrite(BaFe$_{12}$O$_{19}$)가 결정화되었다. TiO$_{2}$를 9wt%첨가한 조성에 대하여 활성화에너지와 진동수는 각각 235.45kJ/mol, 진동수 6.89x$10^{17}$S$^{-1}$이었으며, Avrami지수는 1$\leq$n $\leq$로서 일방향의 결정성장으로 나타났다. 또한, ZrO$_{2}$9wt% 첨가 조성에서는, 활성화에너지와 진동수는 각각 173.86kJ/mol, 2.65x$10^{14}$S$^{-1}$이었으며, Avrami지수는 2$\leq$n$\leq$3로서 이방향의 결정성장을 나타내었다.내었다.

• The Transactions of the Korean Institute of Electrical Engineers
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• v.41 no.8
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• pp.858-868
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• 1992

0.085Ba(LaS11/2TNbS11/2T)OS13T-0.915Pb(ZrS1yTTiS11-yT)OS13T (0.45$\leq$y$\leq$0.65) transparent electrooptic ceramics were fabricated by two-stage sintering method. The structural, ferroelectric and electrooptic properties were investigated varying composition and second sintering time. Also the possibility of application to electrooptic device was studied. If we increase the PbZrOS13T contents, dielectric constants were increased and Curie temperature was decreased. In the composition of 0.55[mol] PbZrOS13T, electromechanical coupling factor and piezoelectric charge constant were the highest values of 43[%] and 173x10S0-12T[C/N], respectively. Mechanical quality factors were decreased with the increasing PbZrOS13T contents. Light transmittance was increased with wavelength when measured from 300[nm] to 900[nm], and with PbZrOS13T contents in the range of 0.50[mol]-0.65[mol], and had the highest value of 67[%] in the composition of 0.65[mol] PbZrOS13T. From the results of ferroelectric hysteresis loop and transmitted light intensity with electric field, the specimens with compositions of 0.65,0.60,0.55[mol] PbZrOS13T were applicable to electrooptic memory device and those with compositions of 0.50,0.45[mol] PbZrOS13T were applicable to linear electrooptic device.

• Progress in Medical Physics
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• v.9 no.3
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• pp.137-141
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• 1998

The purposes of this report are to evaluate whether lead ball and steel ball could be used as protective material of radiation and to acquire physical data of them for protecting 4-10 MV X-ray beams. Lead balls of diameter 2.0～2.5mm or steel balls of diameter 1.5～2.0 mm were filled in an acrylic box of uniform width. An MV radiograph of metal balls in a box were taken to ascertain uniformity of ball distribution in the box. Average density of metal ball and linear attenuation coefficient of metal balls for 4～10 MV X -rays were measured. At the time of measurement of linear attenuation coefficient, Farmer ionization chamber was used and to minimize the scatter effect, distance between the ball and the ionization chamber was 70 cm and field size was 5.5cm${\times}$5.5cm. For comparison, same parameters of lead and steel plates were measured. The distribution of metal balls was uniform in the box. The density of a mixture of lead-air was 6.93g/cm$^3$, 0.611 times density of lead, and the density of a mixture of steel-air was 4.75g/cm$^3$, 0.604 times density of steel. Half-value layers of a mixture of lead-air were 1.89 cm for 4 MV X-ray, 2.07 cm for 6 MV X-ray and 2.16 cm for 10 MV X-ray, and approximately 1.64 times of HVL of lead plate. Half-value layers of a mixture of steel-air were 3.24 cm for 4 MV X-ray, 3.70 cm for 6 MV X-ray and 4.15 cm for 10 MV X-ray, and approximately 1.65 times of HVL of lead plate. Metal balls can be used because they could be distributed evenly. Average densities of mixtures of lead-air and steel-air were 6.93g/cm$^3$, 4.75g/cm$^3$ respectively and approximately 1.65 times of densities of lead and steel. Product of density and HVL for a mixture of metal-air are same as the metal.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.16 no.1
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• pp.65-69
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• 2003

ZnO-Si-ZnO multi-layer thin films have been deposited by pulsed laser deposition (PLD). And then, the films have been annealed at 300$^{\circ}C$ in oxygen ambient pressure. Peak positions of ultraviolet (UV) and visible region were changed by addition of Si layer. Mobility of the films was improved slightly than ZnO thin film without Si layer. The structural property changed by inserting intermediate Si layer in ZnO thin film. The optical properties and structural properties of ZnO-Si-ZnO multi-layer thin films were characterized by PL(Photoluminescence) and XRB(X-ray diffraction) method, respectively. Electrical properties were measured by van der Pauw Hall measurements

• Electrical & Electronic Materials
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• v.7 no.5
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• pp.369-375
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• 1994

In this study, ferroelectric thin films of PZT with different Zr/Ti ratio were prepared by sol-get processing and annealed by rapid thermal annealing at >$500^{\circ}C$>$-700^{\circ}C$ for 10 sec. -1 min. Structures of the annealed films were examined by X-ray diffraction and SEM. Thin films of PZT with perovskite structure have been obtained by annealing at >$600^{\circ}C$ or above and for 20 seconds or longer. Maximum remnant polarization of 10.24.mu.C/cm$^{2}$ and minimum coercive field of 20.06 kV/cm were obtained from the 56/44 and 65/35 Zr/Ti composition films, respectively. Dielectric constant, .epsilon.$_{r}$ of 500-1300 and dielectric loss, tan .delta., of 0.01-0.035 were obtained from the films.s.

• Journal of the Korea Concrete Institute
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• v.28 no.1
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• pp.59-65
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• 2016

Commercial synthetic resins with great amount of hydrogen atoms were investigated for neutron shielding aggregates. Total three types of resins were considered in this study: high density polyethylene (HDPE), polypropylene (PP), and ultra molecular weight polyethylene (UPE). When these resins replaced 20, 40, 60 vol% of fine aggregates, mechanical properties were first evaluated including compressive and tensile strengths, and then image/microstructure analyses such as cross-section analysis, SEM, and X-ray CT were performed. The results showed that the compressive and tensile strengths decreased with the increase of replacement ratio of HDPE and PP, which was found through image analysis that it was closely related to the distribution of resins at the failure surface of test specimens. The strength reduction of UPE was quite small compared to HDPE and PP but it abruptly increased when the replacement level exceeded 60 vol%. The results of microstructure analyses indicated that the replacement level significantly affected the amount of air void so that it is critical to determine the reasonable amount of UPE to make cementitous materials for neutron shielding.