• Korean Journal of Heritage: History & Science
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• v.44 no.4
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• pp.142-153
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• 2011

'Silla Monument Stone in Jungseong-ri, Pohang' was discovered in Pohang City, Gyeongsangbuk Province of Korea in 2009. The monument stone with irregular shape has dimensions of maximum height of 105cm, width of 47.6~49.6cm, thickness of 13.8~14.7cm and weight of 115kg. The results of monument stone was found to be granitite. Conservation treatment procedure was carried out in the order of production of Weathering map, cleaning of surface pollutants, consolidation using ethyl silicate. Black pollutant(crust) that covered more than 60% of the surface was analyzed first in order to remove the pollutants on the surface of the monumental stone by cleaning of surface pollutants using laser. The purpose on analysis was not only to verify the pollutants on the stone but also to carry out preliminary cleaning by securing rocks with same pollutant as the monumental stone. As the results of analysis using p-XRF(PMI. INNOV-X, USA) on the site, high level of Mn and Fe were detected, and the analysis of small section that had been fallen off with SEM/EDX for the purpose of quantitative analysis also detected high level of Mn. The Similar contaminants on Stone secured in the manner described above were made into 10 samples ($5cm{\times}5cm$) and was subjected to preliminary cleaning by Nd-YAG Laser(Laser&Physics, Korea). The results of surface observation through portable microscope during cleaning revealed that the power of 460mJ, wavelength of 1064nm and irradiation frequency of 1,800~2,300 per $25cm^2$ were most effective. Evaluation on the preservative treatment was made through confirmation of the extent of removal through color-difference meter measurement and component analysis prior to and following removal of the pollutants. As the result of color-difference meter measurement increase in the brightness was evidenced by the increase in the brightness ($L^*$)value from 33 to 49, and it was possible to ascertain the reduction in the pollutants as the content of Mn was reduced by about 80% from $50,000{\pm}5,000ppm$ to $10,000{\pm}2,000pmm$ from the result of component analysis.

• Journal of Dental Rehabilitation and Applied Science
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• v.35 no.3
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• pp.160-169
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• 2019

Purpose: The purpose of this study was to evaluate the antimicrobial effects of a toothbrush with light-emitting diodes (LEDs) on periodontitis-associated dental biofilm attached to a zirconia surface by static and dynamic methods. Materials and Methods: Zirconia disks (12 mm diameter, 2.5 mm thickness) were inserted into a 24-well plate (static method) or inside a Center for Disease Control and Prevention (CDC) biofilm reactor (dynamic method) to form dental biofilms using Streptococcus gordonii and Fusobacterium nucleatum. The disks with biofilm were subdivided into five treatment groups-control, commercial photodynamic therapy (PDT), toothbrush alone (B), brush with LED (BL), and brush with LED+erythrosine (BLE). After treatment, the disks were agitated to detach the bacteria, and the resulting solutions were spread directly on selective agar. The number of viable bacteria and percentage of bacterial reduction were determined from colony counts. Scanning electron microscopy (SEM) was performed to visualize alterations in bacterial morphology. Results: No significant difference in biofilm formation was observed between dynamic and static methods. A significant difference was observed in the number of viable bacteria between the control and all experimental groups (P < 0.05). The percentage of bacterial reduction in the BLE group was significantly higher than in the other treated groups (P < 0.05). SEM revealed damaged bacterial cell walls in the PDT, BL, and BLE groups, but intact cell walls in the control and B groups. Conclusion: The findings suggest that an LED toothbrush with erythrosine is more effective than other treatments in reducing the viability of periodontitis-associated bacteria attached to zirconia in vitro.

• Journal of the Korean Society of Radiology
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• v.79 no.5
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• pp.254-258
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• 2018

Purpose: Establishment of an appropriate protocol for breast magnetic resonance imaging (MRI) in the study of image quality standards to enhance the effectiveness of medical image information exchange, which is part of the construction and activation of clinical information exchange for healthcare informatization. Materials and Methods: The recommended protocols of breast and MRI scans were reviewed and the questionnaire was prepared by a responsible researcher. Then, a panel of 9 breast dedicated radiologists was set up in Korea. The expert panel conducted a total of three Delphi agreements to draw up a consensus on the breast MRI protocol. Results: The agreed breast MRI recommendation protocol is a 1.5 Tesla or higher device that acquires images with prone position using a breast dedicated coil and includes T2-weighted and pre-contrast T1-weighted images. Contrast enhancement images are acquired at least two times, and include 60-120 seconds between images and after 4 minutes. The contrast enhancement T1-weighted image should be less than 3 mm in thickness, less than 120 seconds in temporal resolution, and less than $1.5mm^2$ in-plane pixel resolution. Conclusion: The Delphi agreement of the domestic breast imaging specialist group has established the recommendation protocol of the effective breast MRI.

• The Journal of Korean Society for Radiation Therapy
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• v.33
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• pp.79-88
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• 2021

Objectives: Bolus, which combines 3D-bolus and Step-bolus, was produced and its usefulness is evaluated. Materials and Methods: A Bolus was manufactured with a thickness of 10mm and 5mm using a 3D printer (3D printer, USA), and a Step Bolus of 5mm was bonded to a 5mm thick bolus. In order to understand the characteristics of Step bolus and 3D bolus, the differences in relative electron density, HU value, and mass density of the two bolus were investigated. These two Bolus were applied to anthropomorpic phantom to confirm its effectiveness. After all contouring of the phantom, a treatment plan was established using the computed treatment planning system (Eclipse 16.1, Varian medical system, USA). Treatment plan was performed using electron beam 6MeV, nine dose measurement points were designated on the phantom chest, air-gap was measured at that point, and dose evaluation was performed at the same point for each bolus applied using a glass dosimeter (PLD). Results: Bolus, which combines 3D-bolus 5mm and Step-bolus 5mm, was manufactured and evaluated compared with 3D-bolus 1cm. The relative electron density of 3D Bolus was 1.0559 g/cm2 and the step Bolus was 1.0590 g/cm2, which was different by 0.01%, so the relative electron density was almost the same. In the lightweight measurement of air-gap, the combined bolus was reduced to 54.32% for all designated points compared to 3D-bolus. In the dose measurement using a glass dose meter (PLD), the consistency was high in phantom using combined bolus at most points except the slope point. Conclusion: Combined bolus made by combining 3D-bolus and Step-bolus has all the advantages of 3D-bolus and Step-bolus. In addition, by dose inaccuracy due to Air-gap, more improved dose distribution can be shown, and effective radiation therapy can be performed.

• Journal of Mushroom
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• v.20 no.3
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• pp.113-118
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• 2022

This study was conducted to diversify the cultivation of mushroom items and develop a competitive variety of Hypsizigus marmoreus. We focused on developing Hypsizigus marmoreus with lower bitterness, likable shape, and high yield. We have collected and tested characteristics of genetic resources from domestic and abroad since 2019. Breeding (2019), characterization (2020), productivity test (2021), and farm demonstration test (2021) have been sequentially conducted. We bred the new variety 'Yunseul' with unique traits. The optimal temperature for mycelial and fruit body growth were 22-25℃ and 15-18℃, respectively. It was similar to the control variety (Mangadak-2Ho) in the pileus form (hemispherical shape) and the cultivation period. However, it was thinner and longer than the control variety with the pileus diameter, thickness, stipe diameter, and length being 19.9 mm, 7.0 mm, 9.4 mm, and 86.3 mm, respectively. The effective number of fruit bodies was 47.8 in bottle cultivation, which was more than that of the control variety. The yield was 197.4 g/bottle (1,100 cc), which was 30% higher than the yield of the control variety, 151.9 g/bottle (1,100 cc). The parent and control varieties were also incubated alongside the new variety. The somatic incompatibility line was distinct. The band pattern in the mycelial DNA PCR reaction was different from that of the parent and control varieties, confirming the hybrid species.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.26 no.4C
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• pp.247-254
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• 2006

Online testing method is one of the numerical experiment methods using experimental information for a numerical analysis directly. The method has an advantage in that analysis can be conducted without using an idealized mechanical model, because mechanical properties are updated from element test for a numerical analysis in real time. The online testing method has mainly been used for the geotechnical seismic engineering, whose major target is sand. A testing method that may be applied to a consolidation problem has recently been developed and laboratory and field verifications have been tried. Although related research thus far has mainly used a method to update average reaction for a numerical analysis by positioning an element tests at the center of a consolidation layer, a weakness that accuracy of the analysis can be impaired as the thickness of the consolidation layer becomes more thicker has been pointed out regarding the method. To clarify the effectiveness and possible analysis scope of the online testing method in relation to the consolidation problem, we need to review the results by applying experiment conditions that may completely exclude such a factor. This research reviewed the results of the online consolidation test in terms of reproduction of the consolidation settlement and the dissipation of excess pore water pressure of a clay specimen by comparing the results of an online consolidation test and a separated-type consolidation test carried out under the same conditions. As a result, the online consolidation test reproduced the change of compressibility according effective stress of clay without a huge contradiction. In terms of the dissipation rate of excess pore water pressure, however, the online consolidation test was a little faster. In conclusion, experiment procedure needs to improve in a direction that hydraulic conductivity can be updated in real time so as to more precisely predict the dissipation of excess pore water pressure. Further research or improvement should be carried out with regard to the consolidation settlement after the end of the dissipation of excess pore water pressure.

• Journal of Animal Science and Technology
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• v.45 no.3
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• pp.355-368
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• 2003

In Exp. 1, this study was conducted to determine the effect of dietary germanium biotite on growth performance and nutrient digestibility in nursery pigs. A total of sixty crossbred pigs (initial body weight 15.09$\pm$0.18kg) were used in this experiment. This study was carried out for 28 days. The five treatments were control (CON; basal diet), GB0.1 (basal diet + germanium biotite 0.1%), GB0.3 (basal diet + germanium biotite 0.3%), GB0.6 (basal diet + germanium biotite 0.6%) and GB1.0 (basal diet + germanium biotite 1.0%). For overall period, ADG and Gain/feed were not significantly different among the treatments. In Exp. 2, a study was conducted to evaluate the effect of germanium biotite as a substitute for antibiotics in growing pigs. A total of fifty five crossbred pigs (initial body weight 32.47$\pm$0.9kg) were used in this experiment. The three treatments were negative control (NC: basal diet without antibiotic), positive control (PC: basal diet + 200ppm CTC) and GB0.3 (basal diet + germanium biotite 0.3%). Pigs fed PC (17%, 385 vs 451 g/d) and GB0.3 (14%, 385 vs 438 g/d) diets grew faster(P<0.05) than pigs fed NC diet. Pigs fed PC and GB0.3 diets resulted higher(P<0.05) ADFI than pigs fed CON diet. However, pigs fed GB0.3 diet had improved gain/feed compared to pigs fed NC diet(P<0.05). Apparent digestibility of DM and N by pigs fed PC and GB0.3 diets were greater(P<0.05) than those by pigs fed NC diet. In Exp. 3, a study was conducted to determine the effect of dietary germanium biotite on growth performance, plasma characteristics, backfat thickness and fecal ammonia gas concentration in finishing pigs. A total of seventy-two finishing pigs (initial body weight 78.56$\pm$1.32kg) were used in this experiment. The treatments included 1) Control (CON; basal diet) 2) GB1.0 (basal diet + germanium biotite 1.0%), 3) GB3.0 (basal diet + germanium biotite 3.0%). Pigs fed GB1.0 diet grew faster than pigs fed CON diet and GB0.3 diet (P<0.05). Also, pigs fed CON diet showed higher(p<0.05) ADFI than pigs fed GB3.0 diet. Pigs fed GB diets had improved gain/feed compared to pigs fed CON diet(P<0.05). Total?and VLDL concentrations in plasma of pigs fed GB diets treatments were significantly decreased compared to those in pig fed CON diet(P<0.05). However, HDL-cholesterol concentration in plasma of the pig was significantly increased compared to those in pigs fed CON diet (P<0.05). Pigs fed CON diet exerted higher(P<0.05) backfat thickness than pigs fed GB1.0 (5.4%, 27.19 vs 25.71mm) and GB3.0 (16.1%, 27.19 vs 22.81mm) diets. Feces from CON treatment were higher in fecal ammonia gas concentration than faces from pigs fed GB1.0 (64.1%, 17.00 vs 6.10mg/kg)and GB3.0 (61.8%, 17.00 vs 6.50mg/kg) treatments(P<0.05). In conclusion, the results suggest that the dietary addition of germanium biotite into diets for nursery pigs did not affect growth performance. The results also suggest the possibility of germanium biotite to replace antibiotic in diets for growing pigs. In finishing pigs, dietary supplementation of germanium biotite was an effective means for improving growth performance and for decreasing Total-and LDL+VLDL-plasma cholesterols, backfat and fecal ammonia gas concentration.

• Journal of Korean Society of Forest Science
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• v.19 no.1
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• pp.1-23
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• 1973

The results of ground vegetation experiment conducted at completely denuded forestland in the mudstone region are summerized as follows: On the reaults of soiling quantity the effect of soiling was observed where depth of soiling over 10 cm was practiced, and a plot where treated with 15cm soiling and without fertilizer showed poor growth and it was even worser than the plot where soiling was practiced only 1 cm in thikness but applied adequate amount of fertilizers. The depth of slits between 30cm and 40cm showed no significant difference in the effect. A plot where covered with vegetation bag showed somewhat better results in seed loss and early growth but no differences observed in the fall result over the none covered plot. And then, it is recommendable to have soiling over 10cm in thikness with slit of 30cm and 30cm in depth and to apply 30 gram of fertilizer (22;22:11, 50 gram) per slit. On various soiling materials trial there were no striking differences in the effect of soiling between weathered granite soil, wheathered tuffs soil and weathered mudstone soil. In the treatment with various green materials, a plot treated with straw mat showed a significant difference at 1 percent. The results show that weathered mudstone soil is effective to use as soiling materials and straw mat treatment was better. On forest fertilization trial, in the mudstone region where red and black pine trees already existing at a rate of 2,000-3,000 trees per hectare had applied 110kg of compound fertilizers (9:12:3 and 22:22:11) per hectare basis in terms of plant nutrient. As a result, the difference in effect between the compound fertilizers was not found however the leaf color and leaf length of the fertilizer added plot showed darker and longer at 30 percent over the no fertilizer received plot. Compound fertilizers, 14:37:12 and 9:12:3 were applied to alder trees at a rate of 20 gram and 40 gram per tree in terms of plant nutrient and a remarkable growth accelerantion was observed where 40 grams of plant nutrient applied. The effect difference between the compound fertilizers was not found. On investigation of tree root elongation, forty years old red pine trees showed only 15cm tap root elongation through mudstone while black pine had 23 cm tap root elongation. The total length of supporting root elongtion of red and black pines showed 20 and 13 meters, respectively. The tap roots of Black locusts were not able to elongate through mudstone, however, the supporting roots tended to develop to the underneath of pine tree where some moisture content is available. Black locusts And grown on the residual soil of mudstone normally die between 8 to 10 years. The red pine trees show flat in tree shape while black pine had triangle in the shape. With the results it can be said that in an artificial reforestation in denuded forest land of the mudstone region the adequate slit and enough amount of fertiliizer application must be provided for the succesful performance of the program. On integrated experimental results of 1972. for the establishment of ground vegetation on the completely denuded forest land in mudstone region, soiling could be effectively practiced with weathered mudstone soil and it would not specially necessiate to have either weathered granite or tuffssoil for the soiling. And the soiling depth should be more than 10 cm in thickness. Among green materials used the straw mat proved to be the most effective reatment. Three major factors which enable to establish ground vegetation by the shortest period of time: A. Physical improvement of soil is necessary to breakdown of the horizontal cracks sushas Slit, contour line plot, seeding hole and etc., and soiling with weathered mudstone soil. B. Chemical improvement of soil: is needed sufficient amount of fertilizer application 300~400kg ha, $N+P_2O_5+K_2O$), and increased production of ground covering and expedite resolution of the vegetation (ground vegetation, fallen leaves and twigs). C. Complete establishment of the basic structure for the erosion control (Prevention of surface soil erosion)

• Journal of the korean academy of Pediatric Dentistry
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• v.26 no.2
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• pp.377-398
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• 1999

Calcium fluoride, created by topical fluoride application, is the reservoir for fluoride ion regulated by pH in the oral environment. Therefore, the amount and the maintenance of calcium fluoride have an important role in preventing dental caries. The aim of this study is to evaluate the effect of Nd:YAG laser irradiation on the generation of calcium fluoride and the acid resistance of tooth enamel. The bovine anterior permanent teeth were prepared (n=276), and divided into following groups : no treatment (control) fluoride application alone, laser irradiation alone, laser irradiation after fluoride application, and fluoride application after laser irradiation. And each group was subdivided based on the application time of 1.23% acidulated phosphate fluoride (APF) (5 min and 30 min) and the irradiation energy of Nd:YAG laser ($20J/cm^2\;and\;40J/cm^2$). In case of fluoride application, each group was divided according to KOH treatment. Twenty three treatment conditions were made for this experiment and twelve specimens were assigned to each treatment condition. In each treatment condition, ten specimens were used for chemical analysis and two specimens were observed under SEM. In groups without treating KOH, fluoride content and the depth of enamel dissolved were measured using enamel biopsy technique. In groups with treating KOH, the amount of calcium fluoride was measured by the treatment with 1 M KOH for 24 hours and enamel biopsy was performed after KOH treatment. The results were analyzed by the fluoride content and the depth of enamel dissolved by enamel biopsy, amount and thickness of calcium fluoride, and the surface structures of enamel. The results are as follows: 1. In groups without treating KOH, the fluoride content of removed enamel showed a positive relationship with the energy density of laser when the laser irradiated before fluoride application 2. In groups without treating KOH, the depth of enamel dissolved decreased more with the combined laser and fluoride treatment than with laser or fluoride treatment, except for the case of $20J/cm^2$ laser irradiation after 5 minute fluoride application (p<0.05). 3. The amount of calcium fluoride did not increased by laser treatment with no statistical significance(p>0.05). 4. The particle size of calcium fluoride increased in case of fluoride treatment after laser irradiation, compared with fluoride application alone. In case of laser treatment after fluoride application, the particle size of calcium fluoride increased and some of the particles fused as well. 5. There were no significant differences in the fluoride content of dissolved enamel between groups without treating KOH and control group, except for the case of laser irradiation after treatment of APF for 30 minutes (p>0.05). 6. In groups with treating KOH, depth of removed enamel in the groups of combined treatment with laser and fluoride was shallower than that in fluoride application groups (p<0.05). 7. In groups without treating KOH, the relationship between fluoride content and the depth of enamel dissolved showed more negative (Spearman correlation coefficient: -0.6281) than in groups with treating KOH (Spearman correlation coefficient: -0.3792). The greater amount of calcium fluoride could be found in case where there was a significant differences of the depth of enamel dissolved between groups with and without treating KOH. From these results, it can be concluded that laser seems to be a little effects on the amount of calcium fluoride formation, but has some effect on the lowering the solubility of calcium fluoride. As the combined treatment of laser and fluoride application showed more effective acid-resistant property, more extended recall period for fluoride application can be achieved with this combined treatment in the clinic.

• Korean Journal of Poultry Science
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• v.29 no.3
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• pp.195-204
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• 2002

Two experiments were conducted to study the effects of nutrient level and feeding method of split diets for a.m. and p.m. on laying hen performance, feed cost and eggshell quality. In experiment 1, 384 ISA Brown layers of 30∼38wk of age were assigned to four treatments which comprise of three replicates each containing 32 birds. The control(C) was fed a conventional single diet throughout the day and split diet groups(T1, T2 and T3) were offered high energy/protein-low Ca diets, and low energy/protein-high Ca diets in a.m.(04:00∼15:00) and p.m.(15:00∼21:00), respectively. In the split diet groups, daily ME and CP consumption, and feed cost were significantly reduced(P<0.05) compared to the C, while the hen-day egg production, average egg weight and daily feed intake were not different among treatments. Due to the reduced daily ME and CP intakes and feed cost, the conversions of feed, ME, CP and feed cost required per day and per kg egg mass were also significantly improved(P<0.05) in the split diet groups. Eggshell qualities (egg specific gravity, egg breaking strength and eggshell thickness) were improved(P<0.05) by split diet feeding. As the Ca level of the p.m. diet increased. In Experiment 2, 384 ISA Brown layers of 50∼58 wk of age were used in three treatments and each treatment was represented by four replicates each containing 32 birds. The control(C) was fed a conventional single diet throughout the day and split diet group(T1) was offered high energy/protein-low Ca diets, and low energy/protein-high Ca diets in a.m.(04:00∼l5:00) and p.m.(15:00∼21:00), respectively. T2 group was fed the diet mixed (50:50) with the a.m. diets in mash and p.m. diet in pellet used T1 group. In T1 and T2 groups, daily feed intake and average egg weight were significantly reduced(P<0.05) compared to the C, while the hen-day egg production was not influenced by the feeding system. Daily ME and CP consumption, and feed cost were reduced(p.0.05), and the conversions of ME, CP and feed cost required per egg were also significantly improved(P<0.05) in T1 and T2, while the conversions of feed, ME, CP and feed cost required per kg egg mass were not different to the C. Eggshell qualities of T1 and T2 were improved(P<0.05) compared to the others. It was concluded the feed and nutrients consumption, feed cost per day or per kg egg mass could be reduced by introducing split diets for a.m. and p.m. and the feeding method of mixed diet of split diets were also convenient and effective for sparing feed cost and improvement of eggshell quality.