• Journal of The Korean Society of Grassland and Forage Science
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• v.19 no.1
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• pp.41-48
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• 1999

This experiment was carried out to determine the effect of the silage additives on improvement of quality of fresh rice straw silage using round bale at the forage experimental field, grassland and forage crops division, National Livestock Research Institute, RDA, Suwon from 1997 to 1998. The experiment was arranged in a randomized block design with three replication. The treatments used in this study were consisted of different additives(control, formic acid, molasses, molasses+urea and inoculant). The rice straw silage with molasses+urea treatment resulted in high crude protein content and in vitro dry matter digestibility were increased with molasses of inoculant treatments compare with the control. The mean dry matter of formic acid treatment material was higher than with control but there was no significant difference in dry matter content among the additives treatments. The pH of molasses treatments significantly increased the proportion of lactic acid(P<0.05) and decreased the proportion of butyric acid. The total organic acid content of all treatments had low around 2%. Ammonia-N of molasses+urea treatment was significantly(P<0.05) higher than that of others, but formic acid or inoculant treatments was lower below 10% per total nitrogen. Over a 7d feeding period, the dry matter intake per cattle on the inoculant treatment was higher that on both the untreated round bale silage of fresh rice straw and rice straw hay. Producing cost per kilogram of round bale silage of fresh rice straw was decreased according to the increasement of harvesting area. It is suggested that application of round bale silage system to fresh rice straw with molasses or inoculant was the best treatment for improving preservation as silage, and that animal intake was enhanced by addition of inoculant to fresh rice straw.

• The korean journal of orthodontics
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• v.29 no.5 s.76
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• pp.613-625
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• 1999

The purpose of this study was to compare the bracket shear bond strengths of the crystal growth solutions with those of the $37\%$ phosphric acid etch technique. The 4 crystal growth solutions were made experimentally in the lab, that is, (1) $30\%$ polyacrylic acid solution containing 0.3 M sulfuric acid (ES 1), (2) $30\%$ polyacrylic acid solution containing 0.6M sulfuric acid (ES 2), (3) $30\%$ polyacrylic acid solution containing 0.3 M sulfuric acid and 0.6 M lithium sulfate(ES 3), and (4) $30\%$ polyacrlic acid solution containing 0.3 M sulfuric acid and $5\%$ phosphoric acid(ES4). The $37\%$ phosphoric acid solution used as a control. Bovine lower incisor tooth enamel was treated by the above solutions for 60 sec, washed out for 20 sec with slow water stream, and bonded lower anterior edgewise bracket with the light curing orthodontic composite resin adhesives. The teeth bonded brackets were stored in the distilled water at room temperature for 24 h, and followed to test the bracket shear bond strength. The acid etch technque showed 177.6 kg/$cm^2$ of mean shear bond strength which was the highest among the enamel treatment solutions. ES 1 shown 58.4 kg/$cm^2$ of mean shear bond strength and that of ES 4 showed 66.5 kg/$cm^2$. There was no significant difference between the two(p>0.05). ES2 showed 110.6kg/$cm^2$ of mean shear bond strength which was $62.3\%$ of that of acid etch technique. ES 3 showed 131.1 kg/$cm^2$ of mean shear bond strength which was the highest among experimental crystal growth solutions and which was $74\%$ of that of acid etch technique. The shear bond strengths of the crystal growth solutions were significantly lower that that of acid etch technique(p<0.05). The results sugest that although bracket shear bond strength of $30\%$ polyacrylic acid solution containing 0.3M sulfuric acid and 0.6 M lithium sulfate were showed the highest, it is low for the clinical application of this solution.

• Journal of the Korea Institute of Building Construction
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• v.9 no.5
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• pp.79-86
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• 2009

In a steel structure, spray-applied fire resistive materials are crucial in preventing structural strength from being weakened in the event of a fire. The quality control of such materials, however, is difficult for manual workers, who can frequently be in short supply. These skilled workers are also very likely to be exposed to environmental hazards. Problems with construction work such as this, which are specifically the difficulty of achieving quality control and the dangerous nature of the work itself, can be solved to some degree by the introduction of automated equipment. It is, however, very difficult to automate the work process, from operation to the selection of a location for the equipment, as the environment of a construction site has not yet been structured to accommodate automation. This is a fundamental study on the possibility of the automation of spray-applied fire resistive coating work. In this study, the linkability of the cutting-edge RTLS to an automation system is reviewed, and a scenario for the automation of spray-applied fire resistive coating work and system composition is presented. The system suggested in this study is still in a conceptual stage, and as such, there are many restrictions still to be resolved. Despite this fact, automation is expected to have good effectiveness in terms of preventing fire from spreading by maintaining a certain level of strength at a high temperature when a fire occurs, as it maintains the thickness of the fire-resistive coating at a specified level, and secures the integrity of the coating with the steel structure, thereby enhancing the fire-resistive performance. It also expected that if future research is conducted in this area in relation to a cutting-edge monitoring TRS, such as the ubiquitous sensor network (USN) and/or building information model (BIM), it will contribute to raising the level of construction automation in Korea, reducing costs through the systematic and efficient management of construction resources, shortening construction periods, and implementing more precise construction

• The korean journal of orthodontics
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• v.40 no.2
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• pp.106-114
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• 2010

Objective: The aim of this experimental study was to evaluate the effects of direct electrical current stimulation (DECS) on bone regeneration in response to an expansion of the inter-premaxillary suture in the rat. Methods: Sixteen 50 - 60 days old Wistar male rats were separated into two equal groups (control and experimental). Both groups were subjected to expansion, and 30-gram of force was applied to the maxillary incisors with helical-spring. In the experimental group, two metallic-screws were placed at lateral parts of the maxillary segments. Electrodes were connected to the screws. The device was activated with current adjustment to measure $10{\mu}A$ continuously and the current was monitored daily during the expansion and early-retention phase. Bone regeneration in the sutural area was histomorphometrically evaluated including new-bone area (${\mu}m^2$), bone perimeter (${\mu}m$), feret's diameter (${\mu}m$) and newly formed bone (%) parameters. Kruskal-Wallis rank and Mann-Whitney U tests were used for statistical evaluation at p < 0.05 level. Results: Statistical analysis showed significant differences between groups for all investigated histomorphometric parameters. New bone area (p = 0.002), bone perimeter (p = 0.004), feret's diameter (p = 0.002) and newly formed bone percentage (p = 0.002) measurements were significantly higher in the experimental group than the control group. Bone histomorphometric measurements revealed that bone architecture in the DECS group was improved. Conclusions: The application of DECS to an orthopedically expanded inter-premaxillary suture area during the early retention phase stimulated the formation of new bone.

• Journal of radiological science and technology
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• v.30 no.1
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• pp.13-23
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• 2007

In recent years, mammography system is changed rapidly from conventional screen-film system to digital system for application to screening and diagnosis. Digital mammography system provides several advantages over screen-film mammography system. According to the information provided by the manufacturer, digital mammography system offers radiation dose reduction in comparison with screen-film mammography system, because of digital detector, particularly direct digital detector has higher x-ray absorption efficiency than screen-film combination or imaging plate(IP). We measured average glandular doses(AGD) in screen-film mammography(SFM) system with slow screen-film combination, computed mammography(CM) system, indirect digital mammography(IDM) system and direct digital mammography(DDM) system using brest tissue-equivalent phantom(glandularity 30%, 50% and 70%). The results were shown as follows : AGD values for DDM system were highest than those for other systems. Although automatic exposure control(AEC) mode was selected, the curve of the AGD values against thickness or glandularity increased significantly for the SFM system with the uniform target/filter(Mo/Mo) combination. Therefore, the AGD values for the high energy examinations were highest in the SFM system, and those for the low energy examinations were highest in the DDM system. But the curve of the AGD values against thickness and glandularity increased gently for CM system with the automatic selection of the target/filter combination (from Mo/Mo to Mo/Rh or from Mo/Rh to Rh/Rh), and the AGD values were lowest. Consequently, the parameters in mammography for each exposure besides detection efficiency play an important role in oder to estimate a patient radiation dose.

• Journal of the Korean earth science society
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• v.39 no.2
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• pp.178-192
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• 2018

The purposes of this study were to develop and apply on learning on geological field trip utilizing the social construction of scientific model. We developed field trip places by considering not only Orion (1993)'s novelty space but also the achievement standards of 2015 national curriculum. The subjects of the study were 8 in the 'G' science gifted education center. We conducted a study using the theme of 'How was formed Mt. Gwanak?' on 5 lessons including a series of 2 field trip lessons and 3 lessons utilizing the social construction of scientific model. Students participated in pre- and post-test on the understanding of scientific knowledge about formation of mountain. Semi-structured interview was used to analyze students' learning about geological field trip in terms of affective domain. Results were as follows. First, there were 2 places of upper-stream valley and down-stream valley separately. They contained outcrops gneiss, granite, joint in the valley, xenolith, fault plane, mineral in the valley. Second, pre- and post-test and semi-structure interview were analyzed in terms of what scientific knowledge students learned about and how Mt. Gwanak was formed. Seven students explained that Mt. Gwanak was volcano during pretest. Seven students described how granite was formed to form Mt. Gwanak. They also understood geological time scale, i.e., metamorphic rock. Third, the geological field trip was effective to low achievement geoscience students as they engaged in the activities of field trip. Using positive responses on affective learning was effective on learning on geological field trip when utilizing the social construction of scientific model. This study suggests that teachers use an example 'model' on geoscience education. This study also suggests that teachers apply the social construction of scientific model to geological field trip.

• Korean Journal of Soil Science and Fertilizer
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• v.43 no.5
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• pp.722-727
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• 2010

This study was conducted to estimate the carbon footprint and to establish the database of the LCI (Life Cycle Inventory) for barely cultivation system. Barley production system was separated into the naked barley, the hulled barley and the two-rowed barley according to type of barley species. Based on collecting the data for operating LCI, it was shown that input of fertilizer was the highest value of 9.52E-01 kg $kg^{-1}$ for two-rowed braley. For LCI analysis focussed on the greenhouse gas (GHG), it was observed that carbon footprint were 1.25E+00 kg $CO_2$-eq. $kg^{-1}$ naked braley, 1.09E+00 kg $CO_2$-eq. $kg^{-1}$ hulled braley and 1.71E+00 $CO_2$-eq. $kg^{-1}$ two-rowed barley; especially two-rowed barley cultivation system had highest emission value as 1.09E+00 kg $CO_2$ $kg^{-1}$ barley. It might be due to emit from mainly fertilizer production for barley cultivation. Also $N_2O$ was emitted at 7.55E-04 kg $N_2O\;kg^{-1}$ barley as highest value from hulled barley cultivation system because of high N fertilizer input. The result of life cycle impcat assessment (LCIA), it was observed that most of carbon emission from barely cultivation system was mainly attributed to fertilizer production and cropping unit. Characterization value of GWP was 1.25E+00 (naked barley), 1.09E+00 (hulled barley) and 1.71E+00 (two-rowed barely) kg $CO_2$-eq. $kg^{-1}$, respectively.

• The Korean Journal of Nuclear Medicine
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• v.33 no.6
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• pp.484-492
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• 1999

Purpose: This study was to evaluate the clinical usefulness of $^{99m}Tc$-MDP bone scintigraphy for assessing vascular ingrowth into the ocular implants after enucleation or evisceration. Materials and Methods: Twenty-four patients (M:F=7:17, mean age: 36 years), who buried a coralline hydroxyapatite after uncomplicated enucleation or evisceration surgery were studied. Dynamic and static scintigraphy on the orbit fossa were obtained after injection of 740 MBq $^{99m}Tc$-MDP to evaluate the status of vascularization. The study was performed from the 3 to 33 weeks after surgery. According to the visual analysis, activity greater than nasal bridge was graded as 4, equal to the nasal bridge as 3, less than nasal bridge but greater than normal orbit as 2, greater than normal orbit but less than grade 2 as 1. Uptake ratio was also calculated by measuring the implants activity (H) and contralateral orbit activity (N). Grading score and uptake ratio were compared with clinical outcome of vascularization. Additionally, we also analyzed the vascularization status as time lapse between primary surgery and scintigraphic study and surgical methods. Results: Twenty-one patients who had bone scintigraphy at 11 weeks after surgery showed increased uptake above grade 2 and greater H/N ratio than 1.16. Of these, 19 patients who had drilling surgery for permanent peg application showed adequate bleeding during the procedure. The activity grade and uptake ratio were inversely correlated with vascular ingrowth. Higher than grade 2 or greater than 1.56 in H/N ratio seemed to be an indicator for better prognosis. Accomplishment of vascularization was not affected by the surgical way such as enucleation or evisceration. Conclusion: $^{99m}Tc$-MDP bone scintigraphy can be a useful method to evaluate the vascularized status of implants. Adequate time for $^{99m}Tc$-MDP bone scintigraphy may be 11-20 weeks after enucleation or evisceration.

• Korean Journal of Weed Science
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• v.11 no.3
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• pp.178-186
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• 1991

This study was conducted to evaluate the major weeds occurred in direct seeded rice and their compition with rice, and to establish the effective weed control method. The important weeds occurring in dry direct seeded rice were Echinochloa crusgalli, Cyperus amuricus, Rorippa islandica, etc. Among them, Echinochloa crusgalli was the most dominant weed species. In view of the Simpson's dominance index, the maximum number of the weeds was observed at 30 days after seeding, showing 0.26, but decreased as the time passed. In other hand, Simpson's dominance index of weed dry weight increased from 0.09 at 15DAS(days after seeding) to 0.28 at 60DAS indicating that particular weed such as barnyardgrass was dominating the fields. The plant height and the tiller number of rice in the dry direct seeded rice were not greatly affected by the time and duration of competition with weeds, but rice yield was greatly influenced by them. The yield reduction was observed when compition between rice and weeds were initiated at 20 to 40 DAS till the harvesting time. The highest weed control efficacy was observed at the treatment of systematic herbicide application such as soil applied Butachlor followed by Mefenacet/Bensulfuron-methyl/Dymron at 30 DAS after seeding, and soil applied Dimepiperate/Bensulfuron-methyl mixture as a preemergence type gave also an excellent control.

• Journal of Korean Ophthalmic Optics Society
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• v.9 no.2
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• pp.333-343
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• 2004

Impression cytology refers to application of cellulose acetate filter material to the ocular surface to remove the superficial layers of the conjunctival epithelium. The technique is non-invasive, is easy to perform, causes minimal discomfort to the patient, and can be used to follow changes in the conjunctival ocular surface over time. With this method, the morphology of the conjunctival ocular surface can be studied and the degree of squmaous metaplasia assessed. This study was performed to evaluate the conjunctival surface by impression cytology in dry eye patients. A total of 70 students with no contact lens wearing history were recruited. Subjects were required to fill in a McMonnies dry eye symptom questionnaire. The non-invasive tear thinning time(TIT) test of each subject was measured, followed by Schirmer tear test(STI), tear film break-up time(TBUT) tests and Rose-bengal staining were performed as a baseline. Conjunctival epithelial cells from the inferior bulbar conjunctiva were harvested by the impression cytology technique. The specimens collected were labelled and stained with PAS(Periodic Acid Schift)-haematoxylin. The goblet cells and conjunctival epithelial cells were observed under a light microscope of 400x magnification. The specimens were classified according to the Nelson Grading scale which was based on the degree of squamous metaplasia such as changes of goblet cells density, size/form, N:C(nucleus : cytoplasm) ratio. Dry eye patients were observed morphological changes of the epithelial cells, different nuclear alterations, decrease of the goblet cells density. The degree of cytological changes was related to severity of dry eye conditions. When the epithelial cell morphology was graded according to the system described by Nelson, specimens from the control group revealed 91.43% of the eyes to be grade 0 and 8.57% to be grade 1, whereas of the dry eye patients, 20% were grade 0, 42.86% grade 1, 34.29% grade 2 and 2,86% grade 3. Impression cytology represents a non- or minimally invasive biopsy of the ocular surface epithelium with no side effects or contraindications. It has demonstrated to be a useful diagnostic aid for a wide variety of processes involving the ocular surface. This technique is a safe, simple method and may help increase understanding of various ocular surface alterations in dry eye patients.