• The korean journal of orthodontics
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• v.31 no.2 s.85
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• pp.249-259
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• 2001

This study was designed to evaluate the expression of heat shock protein in tooth and surrounding tissue during the experimental movement of rat incisors, by LSAB(labelled streptavidine biotin) immunohistochemical staining for heat shock protein. Twenty seven Sprague-Dawley rats were divided into a control group(3 rats), and 6 experimental groups(24 rats), to which 75g of force was applied from helical springs across the maxillary incisors. Rats of experimental groups were sacrificed at 0.5, 1, 4, 7, 14 and 28 days after force application, respectively. And the periodontal tissues of a control group and experimental groups were studied immunohistochemically. The results were as follows : 1. In control group, the expression of HSP47 was rare in gingiva, dentin and cementum, and mild in periodontal ligament and alveolar bone. But it was more evident than that of HSP70. 2. The expression of HSP47 or HSP70 was rare or mild in dentin, cementum and odontoblast of experimental group, regardless of the duration of force application, which was not different from that of control group. 3. In experimental group, the expression of HSP47 got to the highest degree in periodontal ligament and alveolar bone at 4 days after force application, and then decreased. And the expression was more evident in the pressure side than in the tension side of periodontal ligament 4. The expression of HSP70 began to increase at 12 hours after force application and got to the highest degree at 4 days, in the capillary of pulp and periodontal ligament. And the expression was more evident in the pressure side than in the tension side of periodontal ligament 5. The expression of HSP70 in alveolar bone of experimental group was rare, which was similar to that of control group.

• Korean Chemical Engineering Research
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• v.56 no.4
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• pp.577-584
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• 2018

This study was conducted to investigate the potential of chicken feather (CF), which is a by-product in poultry industry, as a partial substitute of wood fiber in the production of wood-based fiberboard. Keratin-type protein constituted the majority of CF, and its appearance did not differ from that of wood fiber. When the formaldehyde (HCHO) adsorptivities of CF compared by its pretreatment type, feather meal (FM), which was pretreated CF with high temperature and pressure and then grounded, showed the highest HCHO adsorptivity. In addition, there was no difference between the adsorbed HCHO amounts, which was measured by dinitrophenylhydrazine method, of scissors-chopped CF and CF beated with an electrical blender. Mechanical properties and HCHO emission of medium-density fiberboards (MDF), which were fabricated with wood fiber and 5 wt% CF, beated CF or FM based on the oven-dried weight of wood fiber, were not influenced by the pretreatment type of CF. However, when the values compared with those of MDF made with just wood fiber, thickness swelling and HCHO emission of the MDF were improved greatly with the addition of CF, beated CF or FM. Based on the results, it might be possible to produce MDF with improved dimensional stability and low HCHO emission if CF, beated CF or FM is added partially as a substitute of wood fiber in the manufacturing process of MDF produced with the conventional urea-formaldehyde resin of $E_1$ grade. However, the use of CF or FM in the production of MDF has a low economic feasibility at the current situation due to the securing difficulty and high cost of CF. In order to enhance the economic feasibility, it requires to use CF produced at small to medium-sized chicken meat plants. More importantly, it is considered that the technology developed from this research has a great potential to make provision for the prohibition of animal-based feed and to dispose environmentally avian influenza-infected poultry.

• Journal of the Korean Society of Clothing and Textiles
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• v.31 no.12
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• pp.1784-1792
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• 2007

This study set out to identify the problems with hat labels and to search for improvement measures by examining and analyzing consumers' practice of managing their hats. It also intended to provide accurate and enough information about how to keep and wash hats and thus help consumers use their hats for a long period. In an attempt to investigate how consumers wash and manage their hats, a survey was carried out to 395 individuals in their twenties and over who owned hats living in urban areas including Seoul, and were quota sampled according to age and gender. The survey period is March to April 2007. The collected data were statistically treated with the SPSS 12.0 program in terms of frequency, percentage, mean, standard error, cross tabulation, t-test, and one-way ANOVA. The findings were as followed. First, the respondents were in the average level of perceiving and practicing the washing methods of their hats. The female respondents who had more experiences with laundering than the males knew and practiced the washing methods for hats better than males. Second, compared to other clothing items, hat wearers were more likely to pay careful attention to their hats by putting their hats in a laundry net and applying a laundry detergent for wool fabrics when using a washing machine or washing their hats with their own hands. And third, most of the hat wearers were aware of the importance of hat labels and showed a lower level of trust in them than other clothing items. The suppliers need to offer accurate and practical labels in order to regain the consumers' trust. Many consumers had some difficulties figuring out the size system of hats. In particular, the male consumers had a low level of perception of labels, which implies that there should be specific efforts to educate them about general labels.

• Journal of the Korean Society for Nondestructive Testing
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• v.34 no.3
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• pp.254-259
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• 2014

A pressurized heavy water reactor (PHWR) core has 380 fuel channels contained and supported by a horizontal cylindrical vessel known as the calandria, whereas a pressurized water reactor (PWR) has only a single reactor vessel. The pressure tube, which is a pressure-retaining component, has a 103.4 mm inside diameter ${\times}$ 4.19 mm wall thickness, and is 6.36 m long, made of a zirconium alloy (Zr-2.5 wt% Nb). This provides support for the fuel while transporting the $D_2O$ heat-transfer fluid. The simple tubular geometry invites highly automated inspection, and good approach for all inspection. Similar to all nuclear heat-transfer pressure boundaries, the PHWR pressure tube requires a rigorous, periodic inspection to assess the reactor integrity in accordance with the Korea Nuclear Safety Committee law. Volumetric-based nondestructive evaluation (NDE) techniques utilizing ultrasonic and eddy current testing have been adopted for use in the periodic inspection of the fuel channel. The eddy current testing, as a supplemental NDE method to ultrasonic testing, is used to confirm the flaws primarily detected through ultrasonic testing, however, eddy current testing offers a significant advantage in that its ability to detect surface flaws is superior to that of ultrasonic testing. In this paper, effectiveness of flaw detection and the depth sizing capability by eddy current testing for the inside surface of a pressure tube, will be introduced. As a result of this examination, the ET technique is found to be useful only as a detection technique for defects because it can detect fine defects on the surface with high resolution. However, the ET technique is not recommended for use as a depth sizing method because it has a large degree of error for depth sizing.

• Journal of Oral Medicine and Pain
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• v.33 no.1
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• pp.15-26
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• 2008

Purpose : To investigate the actual conditions of diagnosis and treatment of oral medicine inpatient with systemic disease. Methods : A total of 110 subjects, inpatient due to systemic disease for diagnosis and treatment of oral disease was requested to answer the medical history and dental treatment record. Results : Systemic disease is composed of Non-insulin-dependent diabetes mellitus 26%, Cerebral infarction 25.2%, Intracerebral hemorrhage, Polyarthrosis, Coxarthrosis 4.7%, Nerve root and plexus disorders, Hypertensive heart and renal diseases, Ankylosing spondylitis 2.4%. Chief complain of oral disease is composed of toothache 28.6%, routine check 23%, tooth mobility 8.7%, hypersensitivity 7.1%, periodontal bleeding 6.4%. Oral disease is composed of Gingivitis and periodontal diseases 28.9%, Dental caries 17.1%, Diseases of pulp and periapical tissues 15.1%, Diseases of salivary glands 10.5%, Other diseases of hard tissues of teeth 8.6%, Within Normal Limit 5.3%. Treatment of oral disease is composed of periodontal treatment 17.95%, rejection of treatment 16.67%, medication for halitosis & dry mouth 13.46%, extraction 12.18%, prosthetic treatment 8.97%. Chief complain in oral medicine is composed of oral soft tissue problem 6.4%, craniomandibular disorders 5.6%, halitosis 4%, total 16%. Conclusion : These findings indicate that inpatient due to the systemic disease is significantly correlated to the oral disease. The patients of oral disease interrelationship between inpatient and outpatient of systemic disease should be validated by future research.

• Journal of the Korean Society of Radiology
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• v.14 no.5
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• pp.619-626
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• 2020

This study aimed to identify the error rates in Catheter Calibration Mode, Auto Calibration Mode, and Segment Calibration Mode among many calibration modes as a quantitative evaluation tool used for predicting the diameter and length of balloon or stent in percutaneous intravascular balloon dilatation or stent insertion. Our experiment was conducted with Copper Wire of 2 mm × 80 mm (diameter × length) manufactured elaborately for quantitative evaluation in calibration and Metal Ball of 5, 10, 15, 30, and 40 mm and Acryl Phantom of 25 mm, 50 mm, 75mm, 100 mm, 125 mm, 150mm, 175 mm, and 200 mm. At each height, subtraction images were acquired with a cineangiograph and Stenosis Analysis Tool as a software provided by the equipment company was used for measurement. To evaluate the error rates in Catheter Calibration Mode, Copper Wire was put on each acryl phantom before shooting. Copper Wire of 2 mm in diameter was set as a diameter for catheter, and Copper Wire of 8 mm in length was measured with Multi-segments. As a result, the error rates appeared at 1.13 ~ 5.63%. To evaluate the error rates in Auto Calibration Mode, the height of acryl was entered at each height of acryl phantom and the length of 8 mm Copper Wire was measured with Multi-segments and as a result, the error rates appeared at 0 ~ 0.26%. To evaluate the error rates in Segment Calibration Mode, each metal ball on the floor of table was calibrated and the length of 8 mm Copper Wire on each acryl phantom was measured and the length of 8 mm Copper Wire depending on the changes of acryl phantom height was measured with Mutli-segments and as a result, the error rates appeared at 1.05 ~ 19.04%. And in the experiment on OID changes in Auto Calibration Mode, the height of acryl phantom was fixed at 100mm and OID only changed within the range of 450 mm ~ 600 mm and as a result, the error rates appeared at 0.13 ~ 0.38%. In conclusion, it was found that entering the height values in Auto Calibration Mode, among these Calibration Modes for evaluating quantitative vascular dimensions provided by the software was the calibration method with the least error rates and it is thus considered that for calibration using a metal ball or other objects, putting them in the same height as that of treatment sites before calibrating is the method that can reduce the error rates the most.

• Journal of Korean Society of Forest Science
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• v.87 no.2
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• pp.201-210
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• 1998

Sex ratios, and patterns of tree size and growth variation, resource allocation, spatial and age class distribution between the sexes were investigated in natural populations of the sexual trees, R. trichocarpa and R. sylvestris, and the mainly asexual, clonal tree, R. javanica of the dioecious Rhus (Anacardiaceae) distributed in Korea. Sex ratios for three species exhibited a significant degree of female bias, but among the populations, sex ratios were seen to vary quite widely. The measurement of tree size and annual increment of male trees in R. trichocarpa and R. sylvestris were significantly higher than those of female trees, but not significantly different in R. javanica. In all of the species, flowering branch number per individual and inflorescence number per branch of males outnumbered those of females. Branch number per individual, rachis(leaf) number per branch and rachis(leaf) number per inflorescence were more in females than in males. These results were considered as reproductive efforts to increase the pollen supply in males and the fruit production in females. Spatial distribution analysis in two different populations of R. trichocarpa indicated that males and females were randomly distributed in space, but seedlings were clumped around parental trees. Analysis of age class distributions between the sexual reproduction trees, R. triclaocarpa and R. sylvestris, and the asexual, clonal tree, R. javanica showed a different distribution in frequencies of males and females in each age class. These results showed that sexual and asexual reproduction tree species had almost different preference of habitats, and different sex ratio and annual growth.

• Journal of the korean academy of Pediatric Dentistry
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• v.31 no.2
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• pp.290-298
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• 2004

In children, change in lifestyles such as an increase in participation of physical activities has increased the chance of receiving an injury, harming the child and their parents. This study was carried out to give basic information of traumatic injuries to the upper anterior teeth which can be used in prevention of future complications that may arise. From June, 2002 to May, 2003, of the 8,799 children in their primary and mixed dentition visiting Department of Pediatric Dentistry, College of Dentistry, Yonsei University 955 upper anterior teeth(primary 543, permanent 412) of 487 children(male 316, female 171) with traumatic injures to the upper incisors were studied. The results were as follows: 1. Trauma to the primary teeth prevailed at the age of 1-3 and to the permanent teeth at the age of 7. The male to female ratio was 1.85:1. 2. Trauma to the upper incisors for both the primary and permanent teeth occurred in the afternoon. Primary teeth were injured most frequently in the home(44.1%) and the permanent teeth outdoors, in the street(17.5%). 3. Both the primary and permanent teeth were most injured by fall-down injuries(39.8%, 12.9%), and next were collisions(22.2%, 6.0%). For the primary teeth, high fall, traffic accident, violence and sports are next in order, and for the permanent teeth, violence, sorts, traffic accidents were next. 4. Average number of 1.6 primary teeth and 2.8 permanent teeth were injured with the right central incisor most prevailing. 5. Crown fracture without pulpal exposure and subluxation injures were highest in frequency in both the primary and permanent teeth.

• Restorative Dentistry and Endodontics
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• v.31 no.5
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• pp.390-397
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• 2006

The purpose of this study was to evaluate the accuracy and the consistency of four different electronic apex locators in an in vitro model. Fourty extracted premolars were used for the study. Four electronic apex locators (EAL) were Root ZX, Smarpex, Elements Diagnostic Unit (EDU), and E-Magic Finder Deluxe (EMF). After access preparation, the teeth were embedded in an alginate model and the length measurements were carried out at '0.5' and 'Apex' mark using four EALs. The file was cemented at the location of the manufacturers' instruction (Root ZX, EDU, EMF: 0.5 mark, SmarPex: Apex mark). The apical 4mm of the apex was exposed and the distance from the file tip to the major foramen was measured by Image ProPlus (${\times}100$). The distance from the file tip to the major foramen was calculated at 0.5 and Apex mark and the consistency of 0.5 and Apex mark was compared by SD and Quartile of Box plots. In this study, Root ZX and EMF located the apical constriction accurately within ${\pm}0.5 mm$ in 100%, whereas SmarPex and EDU located in 90% and in 70% respectively. For Root ZX and EMF, there was no significant difference between the consistency of 0.5 and Apex mark. However, for the EDU and SmarPex, Apex mark was more consistent than 0.5 mark. From the evaluation of the consistency in this study, for Root ZX and EMF, both 0.5 and Apex mark can be used as a standard mark. And for EDU and SmarPex, the Apex mark can be recommended to be used as a standard mark.

• Journal of Korean Society of Forest Science
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• v.36 no.1
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• pp.26-32
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• 1977

Press drying was used on sapwood and heartwood of oak (Qercus acutissima Carruthers) to find profitable means of drying low grade logs. This study was designed to investigate the process of press drying considering core temperature, current moisture content, drying rate, drying time, final moisture content, dimensional change and drying defects. The drying tests were conducted using 1.5 centimeter thick material at platen temperature of $175^{\circ}C$ and pressure of 35psi. The results were summarized as fallows. 1. Core temperature was divided into three stages of drying characterized by initial heating period, plateau temperature, and period of rising core temperature. Plateau temperature of heartwood material was higher and longer than that of sapwood material. 2. The predicting equation for change in drying rate of sapwood material was log y=-2.7925-0.0811x as function of time. That of heartwood material was log y=-3.3382-0.0468x. 3. Sapwood material reduced the moisture content from 59 to 2.5 percent in 45minutes. Heartwood material reduced the moisture content from 64 to 3.3 percent in 55 minutes. 4. Shrinkage during press drying were 20.4 percent in thickness direction and 2.5 percent in width direction. Recovery on equilibrium conditioning at 65 percent relative humidity and temperature of $20^{\circ}C$. were 11.4 percent in thickness direction and 49.4 percent in width direction. 5. Heartwood material developed severe honeycombing and moderate checking. The sapwood material dried without honeycombing, checking and collapse. All material kept wood flat.