• Clean Technology
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• v.20 no.4
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• pp.375-382
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• 2014

This work investigated the plasma-catalytic decomposition of isopropyl alcohol (IPA) and the behavior of the byproduct compounds over monolith-supported metal oxide catalysts. Iron oxide ($Fe_2O_3$) or copper oxide (CuO) was loaded on a monolithic porous ${\alpha}-Al_2O_3$ support, which was placed inside the coaxial electrodes of plasma reactor. The IPA decomposition efficiency itself hardly depended on the presence and type of metal oxides because the rate of plasma-induced decomposition was so fast, but the behavior of byproduct formation was largely affected by them. The concentrations of the unwanted byproducts, including acetone, formaldehyde, acetaldehyde, methane, carbon monoxide, etc., were in order of $Fe_2O_3/{\alpha}-Al_2O_3$ < $CuO/{\alpha}-Al_2O_3$ < ${\alpha}-Al_2O_3$ from low to high. Under the condition (flow rate: $1L\;min^{-1}$; IPA concentration: 5,000 ppm; $O_2$ content: 10%; discharge power: 47 W), the selectivity towards $CO_2$ was about 40, 80 and 95% for ${\alpha}-Al_2O_3$, $CuO/{\alpha}-Al_2O_3$ and $Fe_2O_3/{\alpha}-Al_2O_3$, respectively, indicating that $Fe_2O_3/{\alpha}-Al_2O_3$ is the most effective for plasma-catalytic oxidation of IPA. Unlike plasma-alone processes in which tar-like products formed from volatile organic compounds are deposited, the present plasma-catalyst hybrid system did not exhibit such a phenomenon, thus retaining the original catalytic activity.

• The Korean Journal of Nuclear Medicine
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• v.39 no.1
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• pp.49-56
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• 2005

Purpose: Dedicated animal PET is useful equipment for the study of new PET tracer. recently, microPET R4 was installed in the Korea institute of radiology and medical science. In this study, we measured the characteristics of scanner. Materials and methods: Resolution was measured using a line source (F-18:65 ${\mu}Ci$, inner diameter: 0.5 mm). The line source was put in the axial direction and was moved from the center of field of view to outside with 1 mm interval. PET images were reconstructed using a filtered back-protection and ordered subset expectation maximization. line source (16.5 ${\mu}Ci$, 78 mm) was put on the tenter of axial direction to measure the sensitivity when the deadtime was under 1%. Images were acquired during 4 minutes respectively from center to 39 mm outward. Delayed count was subtracted from total count and then decay was corrected for the calculation of sensitivity. Noise equivalent count ratio and scatter fraction were calculated using cylindrical phantom. Results: Spatial resolution of reconstructed image using filtered back-projection was 1.86 mm(radial), 1.95 mm(tangential), 1.95 mm(axial) in the tenter of field of view, and 2.54 mm, 2.8 mm, 1.61 mm in 2 cm away from the center respectively. Sensitivity was 2.36% at the center of transaxial field of view. Scatter fraction was 20%. Maximal noise equivalent count ratio was 66.4 kcps at 242 kBq/mL. Small animal images were acquired for confirmation of performance. Conclusion: Performance characteristics of microPET R4 were similar with reported value. So this will be a useful tool for small animal imaging.

• The Korean Journal of Nuclear Medicine
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• v.39 no.1
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• pp.57-68
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• 2005

Purpose: The objective of this study was to assess attenuation correction algorithms with the $^{137}Cs$ point source for the brain positron omission tomography (PET) imaging process. Materials & Methods: Four different types of phantoms were used in this study for testing various types of the attenuation correction techniques. Transmission data of a $^{137}Cs$ point source were acquired after infusing the emission source into phantoms and then the emission data were subsequently acquired in 3D acquisition mode. Scatter corrections were performed with a background tail-fitting algorithm. Emission data were then reconstructed using iterative reconstruction method with a measured (MAC), elliptical (ELAC), segmented (SAC) and remapping (RAC) attenuation correction, respectively. Reconstructed images were then both qualitatively and quantitatively assessed. In addition, reconstructed images of a normal subject were assessed by nuclear medicine physicians. Subtracted images were also compared. Results: ELEC, SAC, and RAC provided a uniform phantom image with less noise for a cylindrical phantom. In contrast, a decrease in intensity at the central portion of the attenuation map was noticed at the result of the MAC. Reconstructed images of Jaszack and Hoffan phantoms presented better quality with RAC and SAC. The attenuation of a skull on images of the normal subject was clearly noticed and the attenuation correction without considering the attenuation of the skull resulted in artificial defects on images of the brain. Conclusion: the complicated and improved attenuation correction methods were needed to obtain the better accuracy of the quantitative brain PET images.

• Korean Journal of Heritage: History & Science
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• v.49 no.2
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• pp.190-205
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• 2016

Buddhist stupas, which are a symbolic architecture of Buddhism and enshrine the Jinsinsari of Buddha, were reinvented as stone stupas appropriate for the natural soil of Korea from existing wooden stupas around the 7th century after the introduction of Buddhism. Later, the construction of a stone stupa was expanded to local areas from the central area around the 9th century; thus, stone stupas of more diverse local colors were built in a nationwide scale, and today it is called a "country of stone stupas". While focusing on the stylistic interchanges between stone stupas, which were established in each region in accordance with the localization of the establishment of stone stupas that was begun actively from the 9th century, this paper selected several cases of stone stupas among about 50 stone stupas in the Gangwondo-region. First, the study compared the stone stupas and Buddhist priest tower of Seollimwonji, Jinjeonsaji, and Geodonsaji, which are located at the same temple site as the current Buddhist priest tower, from among typical Silla style stupas that match the 9 stone stupas in the Gangwon-do region. This is because stylistic interchanges were possible while there were mutually organic relationships between Buddhist statues such as stone stupas, Buddhist priest towers, stone lanterns, and Buddhist pedestals, which used the same stone material along with the expansion of Buddhism to local areas in accordance with the spread of Zen Buddhism in the 9th century. Second, a comparison was made of the stylistic similarities between the Woljeongsa Palgakgucheong (eight sides nine-storied) stone stupa and the Sinboksaji Samcheung (three-storied) stone stupa, which are totally different in regard to the number of stories and the flat form. These two stone stupas are representative Goryeo stone stupas. The Woljeongsa stone stupa is a Goguryeo-oriented stone stupa with many sided multiple stories whereas the Sinboksaji stone stupa has been known as an early case of the insertion of the support of Tapsin in each story. Although the two stone stupas may look very different, but through close investigation it was confirmed that there were many stylistic interchanges between them and not only the seated stone Buddha statue in the cylinder jewel case in front of the stupa but also the stone stupa established by the same master. Consequently, this paper aimed not merely to mention the simple patterns of stone stupas, but, further, to trace the interchange in patterns in accordance with the construction period based on those patterns.

• Korean Journal of Heritage: History & Science
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• v.45 no.2
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• pp.54-71
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• 2012

This paper investigates Buddhist sculptures of the Gulsan-sa School of Seon Buddhism, which was established by the priest Beomil(梵日) at Myeongju(溟州), present-day Gangneung(江陵) area, and prospered until the late Goryeo period. There are very few surviving Buddhist images at Gulsan2 temple-site showing the Buddhist art when Beomil or his disciples, Gaecheong(開淸) and Haengjeok(行寂), were active, except a set of huge stone pillars for temple-banners and a stone monk stupa. It is therefore necessary to focus on pieces of artworks in Gangneung and nearby areas to explore the characteristics of Buddhist art of Gulsan-sa from the late Silla to early Goryeo period. For example, the stone relief seated Buddha image, one of Four Buddhas of Four Directions, and a stone relief of standing Guardian King both from the stone pagoda at Mujin temple-site(無盡寺址) can be compared with stupa reliefs at the capital Gyeongju area in their high quality of carving. The stone octagonal base showing seven lions on each of seven sides at Boheon-sa(普賢寺) demonstrates that it was made as a part of an octagonal lotus pedestal for a Vairocana Buddha now lost. Since Boheon-sa was erected by Gaechung, a disciple of Beomil as a branch of Gulsan-sa, it is fair to assume that the Vairocana image at Boheon-sa might have been closely related to the Buddhist images at Gulsan-sa in its style and iconography. The stone seated Bodhisattva from Hansong temple-site(寒松寺址) displays a benign face, exquisite necklace, and exotic iconography in its hand gesture and high cylindrical crown. The stone seated Buddha at Cheonghak-sa(靑鶴寺), brought from a temple-site where fragments of roof-tiles with the inscription of Heukam-sa(黑岩寺) were discovered, displays the late Silla and early Goryeo period. Heukam-sa seems to have been related to Gulsan-sa or have been one of the branches of Gulsan-sa. Extant fragments of artworks at Myeongju implicate the high quality of Buddhist art of Gulsan-sa in its iconography and style as well as unique features of Gulsan-sa Seon School.

• Korean Journal of Heritage: History & Science
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• v.54 no.2
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• pp.22-37
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• 2021

The wind chime is a longstanding Jangeomgu (majestic article) found in Korea, China, and Japan. However, basic research on wind chimes is currently inadequate as it is difficult to estimate the time of production, and there are few relics. Therefore, this research morphologically classifies the eight bronze wind chimes decorating the baldachin of the Stone Standing Maitreya Bodhisattva of Gwanchoksa Temple, Nonsan. Based on this, the manufacturing techniques and production period are scientifically demonstrated. The synthesis of the research results reveals that the structure and characteristics of the wind chimes of the Stone Standing Maitreya Bodhisattva of Gwanchoksa Temple, Nonsan differ depending on their location on the baldachin. The four large-sized wind chimes on the lower-baldachin were manufactured by casting a Cu-Sn-Pb alloy, and they are estimated to have been made during the early period of Goryeo. The two medium-sized wind chimes of the upper-baldachin's northern direction were manufactured through forging a Cu-Sn or Cu-Sn-Pb alloy, and they appear to have a similar structure to the cylindrical wind chimes appearing during the latter period of Goryeo and the Joseon period. The two small-sized wind chimes of the upper-baldachin's southern direction were manufactured by casting a Cu-Sn-Pb alloy containing Zn, and based on the chemical composition of the alloy and the shape of the clapper, they are estimated to have been manufactured during the latter period of Joseon. Through the observation of microstructures and a chemical composition analysis, it is demonstrated that two wind chimes of the lowerbaldachin were manufactured by casting and slow cooling the alloy with an alloy ratio of Cu:Sn:Pb≒80:15:5. In addition, it is estimated that the wind chimes of the upper-baldachin's northeast direction were manufactured by forging an alloy of Cu-Sn with a similar alloy ratio to that of forged high tin bronze. The results of a comparative analysis of prior research on domestic wind chimes confirm that two wind chimes of the lower-baldachin have a similar composition ratio to the wind chime excavated from Wolnamsaji in Gangjin, containing an amount of tin that corresponds with ancient records. Having a similar alloy ratio to forged high tin bronze, the wind chimes of the upper-baldachin's northeast direction are the only instances among all of the wind chimes that have been examined to date that were manufactured using this forging method. The purpose of this research is to collect baseline data to verify and classify the manufacturing period of wind chimes according to their morphological characteristics based on scientific evidence. It is hoped that this data can be utilized for the restoration and conservation processes of the wind chimes of the Stone Standing Maitreya Bodhisattva of Gwanchoksa Temple, Nonsan.

• Journal of agriculture & life science
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• v.53 no.1
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• pp.117-126
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• 2019

This paper presents an experiment to examine the possibility of treating carcass while making compost with a horizontal cylinder composting equipment. The findings were as follows: as for heavy metal content, zinc content was above the allowed level in some measuring sections of the general operation and the entire measuring sections of the carcass operation, whose copper content was higher than the general operation. The wood chip operation was lower than the allowed level in all the heavy metals and similar or the same as the carcass operation in copper, cadmium and arsenic. Its nickel content was 29.5~63.8%, which was relatively higher than 9.3~18.0% and 15.8~18.0% of the general and carcass operation, respectively. Its chrome content was 14.2~31.9%, which was relatively higher than that of the general and carcass operation. The integrated operation was lower than the allowed level in all the heavy metals. Its copper and zinc content was 34.9~54.5% and 53.1~75.9%, which was similar to 48.9~52.6% and 64.6~85.9%, respectively, in the wood chip operation. Its chrome and nickel content was stabilized while their content was rather high in the wood chip operation. The average and final moisture content of the carcass operation was 60.7% and 49.6%, respectively. Its average moisture content was a little bit higher than the recommended level of 55.0%, but its final moisture content was lower than the recommended level. The average and final moisture content of the integrated operation was 29.2% and 18.6%, respectively, which was the lowest level among the four operation modes. The overall moisture content of the operation modes was under the recommended level of 55.0% with some variance among the modes. The C/N ratio was the lowest in the carcass operation and the highest in the general operation. The average C/N ratio of the operation modes was in the range of 13.7~20.3 with the total average of 18.3, and the modes kept it under the proper level of 30.0.

• Korean Journal of Heritage: History & Science
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• v.54 no.1
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• pp.206-219
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• 2021

The warming of the climate is increasing the damage caused by termites to wooden buildings, cultural properties and houses. A group removal system can be installed around the building to detect and remove termite damage; however, if the site is not visited regularly, every one to two months, you cannot observe whether termites have spread within, and it is difficult to take prompt effective action. In addition, since the system is installed and operated in an exposed state for a long period of time, it may be ineffective or damaged, resulting in a loss of function. Furthermore if the system is installed near a cultural site, it may affect the aesthetic environment of the site. In this study, we created a detection system that uses wood, cellulose, magnets, and magnetic sensors to determine whether termites have entered the area. The data was then transferred to a low power LoRa Network which displayed the results without the necessity of visiting the site. The wood was made in the shape of a pile, and holes were made from the top to the bottom to make it easier for termites to enter and produce a cellulose sample. The cellulose sample was made in a cylindrical shape with a magnet wrapped in cellulose and inserted into the top of a hole in the wood. Then, the upper part of the wood pile was covered with a stopper to prevent foreign matter from entering. It also served to block external factors such as light and rainfall, and to create an environment where termites could add cellulose samples. When the cellulose was added by the termites, a space was created around the magnet, causing the magnet to either fall or tilt. The magnetic sensor inside the stopper was fixed on the top of the cellulose sample and measured the change in the distance between the magnet and the sensor according to the movement of the magnet. In outdoor experiments, 11 cellulose samples were inserted into the wood detection system and the termite inflow was confirmed through the movement of the magnet without visiting the site within 5 to 17 days. When making further improvements to the function and operation of the system it in the future, it is possible to confirm that termites have invaded without visiting the site. Then it is also possible to reduce damage and fruiting due to product exposure, and which would improve the condition and appearance of cultural properties.

• Conservation Science in Museum
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• v.27
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• pp.147-164
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• 2022

Over 200,000 Korean cultural heritage items are currently located abroad. They have made their way to 22 countries under different circumstances and with unique backgrounds. While some of them continue to contribute to promoting Korean culture around the world, others cannot be exhibited due to damage or poor condition. In view of these circumstances, the Overseas Korean Cultural Heritage Foundation (OKCHF) has since 2013 provided museums and art galleries abroad with support for the conservation, restoration, and utilization of the Korean cultural heritage items that they house. As a part of these efforts and on the occasion of the 120th anniversary of the diplomatic relationship between the Republic of Korea and the Kingdom of Belgium in 2021, a gilt-bronze case for acupuncture needles dating to the Goryeo period (918-1392) from the collection of the Royal Museums of Art and History (RMAH), Belgium was brought to Korea for conservation treatment. The primary purpose of this conservation treatment was to restore the original form of the relic and slow to the degree possible the progress of corrosion. The conservation treatment of the gilt-bronze case followed the fundamental order of conservation treatment: removal of corrosive substances, stabilization, and reinforcement. Since this was the first case of restoring metallic cultural properties under the abovementioned support program by the OKCHF, special methodologies distinct from those available in overseas institutions were required. Diverse scientific methods (e.g., X-ray inspection, CT scanning, 3D microscopy) were applied to identify the metalcraft techniques used in the Goryeo period. The analysis found that several designs, including lotus and scrollwork, were exquisitely engraved on the surface of the case by making dots using a round-edged chisel. A bronze plate engraved with designs was rolled into a cylindrical form. The ends were overlapped by 2 to 3 centimeters and then attached to each other by silver soldering. The overlapping ends were welded flat with nearly no gaps. As the final process in the production, the case was lavishly gilt with gold powder using amalgam gilding. The conservation treatment of the gilt-bronze case for acupunctural needles in the RMAH collection restored the original form of the relic and arrested further corrosion. Above all, it revived the historic and academic value of the overseas Korean cultural heritage through scientific analysis.

• Korean Journal of Environment and Ecology
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• v.37 no.1
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• pp.86-93
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• 2023

This study investigated the ecological characteristics of Odontobutis interrupta at the Geumdang Stream from January to December 2021. The riverbed structure of the species habitat was rich in sand and mud. The water was deep, ranging from 21 to 124 cm, with an average of 48 cm. The stream velocity was slow at 0.24 (0.08-0.36) m/sec. The ratio of females to males was 1:0.98, and the total length of collected individuals ranged from 23 mm to 162 mm. The age according to the total length-frequency distribution as of May indicated that the group with a total length of 23-59 mm was one year old, the group with 60-99 mm was two years old, the group with 100-139 mm was three years old, and the group with 140-162 mm was four years old. As a secondary gender characteristic, the females genital papilla had a cylindrical shape, a hollow inside of the tip, and a longer diameter than males. The males had a cone shape with a pointed end. Sexually mature males had the nuptial color, with a black abdomen and whole body. Some females with a length ranging from 60 to 69 mm and all females 70 mm longer were sexually mature. Some males with a length ranging from 70 to 79 mm and all males 80 mm longer were sexually mature. The spawning season was from May to July, and the water temperature was between 19.6℃ to 29℃ during that period. The prosperous spawning season was June (26℃). The average number of eggs in the ovaries was 2,473 (883-4,955) per matured female, and the matured eggs were yellowish and spherical with a mean diameter of 1.42 (1.20-0.54) mm. The correlation between total length and weight was BW=0.0000006TL^3.21 with the constant a as 0.0000006 and parameter b as 3.21. The condition factor (K) was 1.67 (1.18-2.43) on average, and the slope was 0.116.