• Journal of Dental Rehabilitation and Applied Science
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• v.32 no.3
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• pp.184-193
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• 2016

Purpose: To evaluate marginal leakage of bulk fill flowable composite resin filling with different curing time by using microcomputed tomography technology. Materials and Methods: 30 previously extracted human molars were randomly divided into 6 groups based upon restorative system and different curing time. Class II cavities (vertical slot cavities) were prepared. An individual metallic matrix was used to build up the proximal wall. The SonicFill or SureFil SDR flow was inserted into the preparation by using 1 bulk increment, followed by light polymerization for different curing times. The different exposure times were 20, 40, and 60 seconds. All specimens were submitted to 5,000 thermal cycles for artificial aging. Micro-CT scanning was performed by using SkyScan 1272. One evaluator assessed microleakage of silver nitrated solution at the resin-dentin interface. The 3D image of each leakage around the restoration was reconstructed with CT-Analyser V.1.14.4. The leakage was analyzed with the Mann-Whitney test. Results: Significant differences were observed between the light curing times, but no significant differences were found between the bulk fill composite resins. Increasing in the photoactivation time resulted in greater microleakage in all the experimental groups. Those subjected to 60 seconds of light curing showed higher microleakage means than those exposed for 20 seconds and 40 seconds. Conclusion: Increasing the photoactivation time is factor that may increase marginal microlekage of the bulk fill composite resins. Further, micro-CT can nondestructively detect leakage around the resin composite restoration in three dimensions.

• Journal of Korean Society of Forest Science
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• v.89 no.3
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• pp.384-388
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• 2000

For the control of Corythucha ciliata, the insecticidal activity of five commercial pesticides (Monocrotophos 25%SL, Phosphamidon 50%SL, Imidacloprid 20%DC, Thiamethoxam 15%DC and Acetamiprid 20%SL) were examined with trunk injection method in Seoul, Sanbon and Chungju. The insecticidal activity of five commercial pesticides was >88%. The insecticidal activity of Monocrotophos maintained 31 days later after trunk injection when treated leaves were supplied to this pest. This result indicates that one application of trunk injection is enough to control this pest, and this method can save the control cost compared with ground application which should be applied two or three times per year to control this pest. To make the model of treatment dosage at each D.B.H class (cm), $1.0m{\ell}/DBH$, $1.5m{\ell}/DBH$ and $2.0m{\ell}/DBH$ pesticide dosage was used. At <20cm, the insecticidal activity of $1.0m{\ell}$ dosage was >95%, and $1.5-2.5m{\ell}$ dosage was needed for the effective control at 30~50cm. More than $2.5m{\ell}$ dosage was effective at >50cm. Spray method was used in laboratory to select pesticides for ground application. Three commercial pesticides (Ethofenprox 20%EC, Ethofenprox 10%WP and Cyfluthrin 1%EC) were used, and all pesticides showed >95% insecticidal activity.

• Journal of the Korean earth science society
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• v.23 no.5
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• pp.397-405
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• 2002

This study investigated science gifted middle school students' philosophical views on scientific knowledge, and the effects of discussing and reading related to the knowledge. Ten eighth-graders in a science gifted class participated in this study. The results can be summarized as follows: 1, At the beginning, the students had one of six positions: (a) relativism (n = 2); (b) falsificationism (n = 2); (c) borderline between relativism and eclecticism (n = 1); (d) borderline between falsificationism and eclecticism (n = 3); (e) borderline among relativism, falsificationism, and eclecticism (n = 1); and (f) borderline inductivism and eclecticism (n = 1). This result indicated that most students had on almost modern philosophical view of scientific knowledge. 2, Some students, who had chosen the item of inductivism in some questions of the instrument at the beginning, maintained their selection despite discussions and readings related to scientific knowledge. The data were examples which indicated the difficulty of changing from a traditional view to a modern view of scientific knowledge.

• Korean Journal of Animal Reproduction
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• v.14 no.4
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• pp.237-244
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• 1990

These studies were carried out to investigate the effects of the follicles size, hormone supplementation, semen types and capacitation methods on in vitro maturation and fertilization of bovine follicular oocytes. The ovaries were obtained from slaughtered Korean Native cows. The follicular oocytes surrounded with cumulus cells were recovered by aspirating follicular fluid from the visible follicles of diameter 3~5mm. The follicular oocytes were cultured in TCM-199 medium containing hormones, FCS, ECS, BFF and MCC for 24~48hrs. in a incubator with 5% CO2 in air at 38.5$^{\circ}C$ and then matured oocytes were again cultured for 18~20hrs. with motile capacitated sperm in the TCF(Tyroide calcium-free) solution containing 200$\mu\textrm{g}$/ml of heparin. The results obtained in these experiments were summarized as follows : 1. The oocytes classified as "A, B, C, D and Degenerative" depending morphological integrity and those were 61.4%, 12.1%, 19.2%, 4.2% and 3.0% of the total oocytes recovered, respectively. The maturation and fertilization rate of the A, B, C class follicular oocytes, cultured in the TCM-199 medium supplemented with 10% FCS were 89.1%, 78.0%, 52.6% and 78.1%, 66.1%, 33.3%, respectively. 2. The average number of the follicular oocytes recovered from follicles size, 1~2mm, 3~5mm and above 5mm in dimeter were 67, 98 and 63, respectively. The maturation and fertilization rate of the follicular oocytes, cultured in the TCM-199 medium were 56.7%, 82.5%, 46.0% and 44.8%, 71.4%, 28.6%, respectively. 3. The maturation and fertilization rate of follicular oocytes, cultured in the TCM-199 medium supplemented with 5%, 10%, 15%, 20% FCS and hCG, HCG, $\beta$-estradiol were 76.0%~82.3% and 26.2%~70.0%, and those values were higher the supplementation of the hormone than the non-supplementation. 4. The fertilization and cleavage rate of the follicular oocytes, inseminated with spermatozoas of epididymis cauda, neat and frozen semen were 63.3%, 73.3%, 70.0% and 32.7%, 37.8%, 38.3, respectively. 5. The fertilization and cleavage rate of follicular oocytes, fertilized with capacitated spermatozoas by heparin, BFF and HIS methods were 70.0%, 53.8%, 34.2% and 38.3%, 23.1%, 17.1%, respectively. And the fertilization and cleavage rate were higher method of heparin than other methods.r methods.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.12 no.4
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• pp.1749-1755
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• 2011

This study aimed to identify the effect of make-up education on the life satisfaction of elderly women based on a make-up education session for eight weeks from May 28 to July 16, 2010 provided to elderly women aged 60 or above who visited P Seniors' Welfare Center in D city. 80 samples were divided into the experimental group of 40 people and the control group of 40 people based on age and interest in make-up. Their life satisfaction level was identified before the survey. The experimental group received an eight-week make-up education session. In order to verify effects of the make-up education, follow-up tests were conducted toward the experimental and control groups both to compare life satisfaction levels. The make-up education was divided into elegant and natural make-up, make-up to look ten years younger, face-changing make-up, seasonal (spring, summer, autumn, and winter) make-up, make-up for Korean traditional costumes, and party make-up. In each class, students practiced make-up on their face while taking a lecture on theories. After the education, the students found the education satisfactory overall. Based on the results, the life satisfaction of the experimental group who received the make-up education significantly increased (p<0.05), confirming that make-up education affects the life at old age.

• Mycobiology
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• v.45 no.4
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• pp.297-311
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• 2017

Saprolegniasis is one of the most devastating oomycete diseases in freshwater fish which is caused by species in the genus Saprolegnia including Saprolegnia parasitica. In this study, we isolated the strain of S. parasitica from diseased rainbow trout in Korea. Morphological and molecular based identification confirmed that isolated oomycete belongs to the member of S. parasitica, supported by its typical features including cotton-like mycelium, zoospores and phylogenetic analysis with internal transcribed spacer region. Pathogenicity of isolated S. parasitica was developed in embryo, juvenile, and adult zebrafish as a disease model. Host-pathogen interaction in adult zebrafish was investigated at transcriptional level. Upon infection with S. parasitica, pathogen/antigen recognition and signaling (TLR2, TLR4b, TLR5b, NOD1, and major histocompatibility complex class I), pro/anti-inflammatory cytokines (interleukin $[IL]-1{\beta}$, tumor necrosis factor ${\alpha}$, IL-6, IL-8, interferon ${\gamma}$, IL-12, and IL-10), matrix metalloproteinase (MMP9 and MMP13), cell surface molecules ($CD8^+$ and $CD4^+$) and antioxidant enzymes (superoxide dismutase, catalase) related genes were differentially modulated at 3- and 12-hr post infection. As an anti-Saprolegnia agent, plant based lawsone was applied to investigate on the susceptibility of S. parasitica showing the minimum inhibitory concentration and percentage inhibition of radial growth as $200{\mu}g/mL$ and 31.8%, respectively. Moreover, natural lawsone changed the membrane permeability of S. parasitica mycelium and caused irreversible damage and disintegration to the cellular membranes of S. parasitica. Transcriptional responses of the genes of S. parasitica mycelium exposed to lawsone were altered, indicating that lawsone could be a potential anti-S. parasitica agent for controlling S. parasitica infection.

• Applied Chemistry for Engineering
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• v.25 no.1
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• pp.1-13
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• 2014

Lithium ion batteries (LIBs) are the state-of-the-art technology among electrochemical energy storage and conversion cells, and are still considered the most attractive class of battery in the future due to their high specific energy density, high efficiency, and long cycle life. Rapid development of power-hungry commercial electronics and large-scale energy storage applications (e.g. off-peak electrical energy storage), however, requires novel anode materials that have higher energy densities to replace conventional graphite electrodes. Germanium (Ge) and silicon (Si) are thought to be ideal prospect candidates for next generation LIB anodes due to their extremely high theoretical energy capacities. For instance, Ge offers relatively lower volume change during cycling, better Li insertion/extraction kinetics, and higher electronic conductivity than Si. In this focused review, we briefly describe the basic concepts of LIBs and then look at the characteristics of ideal anode materials that can provide greatly improved electrochemical performance, including high capacity, better cycling behavior, and rate capability. We then discuss how, in the future, Ge anode materials (Ge and Ge oxides, Ge-carbon composites, and other Ge-based composites) could increase the capacity of today's Li batteries. In recent years, considerable efforts have been made to fulfill the requirements of excellent anode materials, especially using these materials at the nanoscale. This article shall serve as a handy reference, as well as starting point, for future research related to high capacity LIB anodes, especially based on semiconductor Ge and Si.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.10
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• pp.139-146
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• 2016

The purpose of this study is to investigate the necessity of safety awareness and education regarding the use of laboratories, and to foster safety awareness during intramural and extracurricular activities in high schools. The study conducted a questionnaire to 290 eleventh grade students of three high schools located in Seoul. The collected data were statistically analyzed. The result illustrates that 64.8% of students have experienced safety education during a regular class, 6.6% have experienced accidents, and 68.0% have experienced safety education during field activities. The result concludes that there is a lack of prior safety education as well as overall low awareness on the necessity of safety education. In particular, students who have experienced safety education recognizes the necessity of emergency education regarding laboratory accident more than those who did not receive such education. Thus, a systematic management of laboratory safety education and multilateral management measures for students' safety are required. There is a relatively high correlation between safety intention of R&D and Education factors and Community and Laboratory Safety Education. As much as there is a high safety demand regarding the laboratory instruments and experiment, it shows high intention of safety lab operation as well as count measurement of lab accident. This study recommends developing a laboratory safety education program and management methods appropriate for high school students.

• The Journal of Korean Academy of Prosthodontics
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• v.59 no.4
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• pp.451-458
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• 2021

Currently, digital technology is being used in various fields of dental treatment. In particular, in the case of anterior esthetic restoration, the traditional restoration method cannot contain facial information and it is difficult for the patient to predict the treatment result. However, in the case of esthetic restoration through digital design, the visualization of the prosthesis design and the ease of reflecting patient feedback, and expecting the treatment result is available. In this case, the patient confirmed the results of restoration treatment using a digital method before treatment and obtained consent for treatment in an anterior tooth trauma patient. In addition, since the conventional digital smile design method uses only the patient's facial and smile information, the design was made on a two-dimensional plane, and its application was somewhat limited. However, in this case, a three-dimensional virtual patient was created and thus the designed restoration was viewed from various angles. Through this case, it was possible to obtain a high degree of satisfaction with the ease of communication with the patient and the technician during the esthetic restoration using the digital method, the simplicity of the procedure, and the treatment result.

• Journal of Digital Convergence
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• v.19 no.5
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• pp.175-186
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• 2021

The roles and functions of domestic public libraries are diversifying, but various problems have emerged due to internally biased book lending. In addition, due to the 4th Industrial Revolution, public libraries have introduced a book recommendation system focusing on popular books, but the variety of books that users can access is limited. Therefore, in this study, the public library unborrowed book recommendation system was implemented limiting its spatial scope to Duryu Library in Daegu City to enhance the satisfaction of public library users, by using the loan records data (213,093 cases), user information (35,561 people), etc. and utilizing methods like cluster analysis, topic modeling, content-based filtering recommendation algorithm, and conducted a survey on actual users' satisfaction to present the possibility and implications of the unborrowed book recommendation system. As a result of the analysis, the majority of users responded with high satisfaction, and was able to find the satisfaction was relatively high in the class classified by specific gender, age, occupation, and usual reading. Through the results of this study, it is expected that some problems such as biased book lending and reduced operational efficiency of public libraries can be improved, and limitations of the study was also presented.