• Journal of the Korean Ceramic Society
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• v.23 no.1
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• pp.33-43
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• 1986

The synthesis of high-purity AlN by a vapor-phase reaction was investigated using the $NH_3-AlCl_3-H_2$ reacting system. The theoretical yields of AlN were determined from th thermodynamic equilibrium composi-tions. It was shown that the yields above 90% could by obtained even in the range of relatively low temper-ature of 600-1200K. The reaction temperature and the initial amounts/ratios of the reacting gases showed significant effects on the yields but the total pressure did not. The experimental results showed that a high-purity AlN having a needle shape was the only product as a solid phase and its amount produced increased with the reaction temperature. While the degree of agglmera-tion of the synthesized AlN increased with the reaction temperature the size of each particle consisting of the agglomerates was independent of the temperature but grew from 0.09 to 0.115${\mu}{\textrm}{m}$ with the flow rate of NH3. These experimental results were compared with the theoretical aspects for the synthesis of a high-purity AlN.

• Transactions of the Korean Society of Mechanical Engineers
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• v.16 no.8
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• pp.1421-1428
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• 1992

It has been increasingly recognized that the safety analysis considering fracture mechanics is required of the pressure vessels made of 2 1/4 Cr-1Mo steel for safe operation due to temper-embrittlement during long term service. In this study, the fracture toughnesses of degraded and recovered 2 1/4 Cr-1Mo steels have been studied with J$_{IC}$ test specimens at room temperature and the results will be compared with the data obtained from the Charpy impact test. The fracture toughness data from above experiments will be applied to life prediction based on the surface crack growth for degraded and recovered Cr-Mo pressure vessels.

• Clinical and Experimental Pediatrics
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• v.59 no.sup1
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• pp.92-95
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• 2016

Neuroblastomas are sometimes associated with abnormal constitutional karyotypes, but the XYY karyotype has been rarely described in neuroblastomas. Here, we report a case of an esthesioneuroblastoma in a boy with a 47, XYY karyotype. A 6-year-old boy was admitted to our hospital because of nasal obstruction and palpable cervical lymph node, which he first noticed several days previously. A polypoid mass in the right nasal cavity was detected through sinuscopy. Biopsy of the right nasal polyp was performed. Based on the result, the patient was diagnosed with a high-grade esthesioneuroblastoma. Nuclear imaging revealed increased uptake in both the right posterior nasal cavity and the right cervical IB-II space, suggesting metastatic lymph nodes. Cytogenetic analysis revealed a 47, XYY karyotype. Twelve courses of concurrent chemotherapy were administered. Three years after the completion of chemotherapy, the patient had had no disease recurrence. He manifested behavioral violence and temper tantrums, so we started methylphenidate for correction of the behavior.

• Journal of the Korean Society of Clothing and Textiles
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• v.16 no.4 s.44
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• pp.349-355
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• 1992

Comfortable sleeping largely depends on human mental state, physical condition, the temper. ature and humidity in bedrooms, and qualities of quilt and bedcover. Of the qualities of quilt, thermal insulation effect plays the most important role in keeping bedroom in ample temperature and preventing human body from giving off heat. In the present study, which is a sequel study to research on the thermal insulation effect, the real-size quilts with the following items of filling materials in them are designed to research on the variation of each item, and to measure the effect of the weight variation in inner covers on the thermal insulation effect of quilts, the results are as follows: 1. The coefficient between the weight of filling materials and the thermal insulation effect of quilt is shown to be a significant $0.91\~0.97$. 2. The thermal insulation effect of the quilts with in size of $0.5\;Kg/m^{2}$ is surveyed to be high in order down > polyester > cotton > wool. 3. The effect of the texture of inner covers on the thermal insulation effect of quilt is shown to be ignorably low. 4. The weight of filling materials is shown to be in correlation with the thermal insulation effect of quilts, and the estimated regression line has been obtained.

• Journal of Physiology & Pathology in Korean Medicine
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• v.18 no.1
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• pp.16-21
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• 2004

It is different from the DongEuiBoGam(東醫寶鑑) of Korea traditional medicine that China BeunJungLonChi(中醫辨證論治) was made for the scientific and systematic assortment of China medicine. Symptom(症)is more important than symptom complex(證)in china BeunJungLonChi at DonEuBoGam. And unusual symptoms generally are diseases in DongEuiBoGam. DongEuiBoGam is emphasis on body form, temper, body color, pulse(形氣色脈) and the functional difference of organs by body form and body color. there are many problems in order to unify the theory of Korea traditional medicine by china BeunJungLonChi. I suggest that a new assortment that can combine Sasang constitutional medicine(四象醫學), Constitution-Acupuncture(體質針), and Hyungsang medicine(四象醫學) will be necessary. BeunJungLonChi : diagnosis and treatment based on overall analysis of symptoms and signs, the cause, nature and location of the illness and the patient's physical condition according to the basic theories of traditional Chinese medicine

• Journal of Welding and Joining
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• v.30 no.5
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• pp.70-75
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• 2012

This study is related to the laser weldability of AZ31B magnesium alloy, an all-purpose wrought alloy with good strength and ductility. In general, AZ31B is classified into AZ31B-H24 and AZ31B-O depending on temper designation. Thus, in this study, the laser weldability of AZ31B-H24 and AZ31B-O was investigated and compared. CW Nd:YAG laser was used to produce bead and butt joints. And the effects of welding conditions on the weldability of these joints were examined in detail. As a result of this study, AZ31B-H24 was found to have thinner oxide film and smaller grain size compared with AZ31B-O. Due to such difference, in bead welding, AZ31B-H24 had more wide welding range for full penetration compared with AZ31B-O. Furthermore, it was also confirmed that AZ31B-H24 and AZ31B-O have different welding conditions to obtain stable keyhole in butt welding.

• Journal of the Korean Society of Food Culture
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• v.16 no.4
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• pp.378-387
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• 2001

This study was carried out to investigate breakfast behaviors of female college students. 500 questionnaires were distributed and 417 were used for statistical analysis(SAS program). This survey was conducted from June, 2000 to October, 2000. 44.7% of the respondents considered lunch to be the most important meal. 51.6% students thought that people must eat breakfast. 41.6% of the students always eat breakfast but 22.1% do not eat breakfast. Conventional type of breakfast was found to be the most popular (67.6%). But ￦400,000 monthly allowance group(P<0.05) and self prepared breakfast group preferred Western style breakfast. The main reason for eating breakfast was for health(34.6%). The group of students with less monthly allowance were more likely to skip breakfast due to lack of time (p<0.01). Physical discomforts after skipping breakfast were: lack of strength(42.5%), stomach ache(36.3%), giddiness(9.1%), and recovered temper(12.1%). In conclusion, it is needed that a convenient and nutritional education should be developed for college students' health.

• Journal of the Korean Society for Heat Treatment
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• v.25 no.4
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• pp.196-205
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• 2012

The purpose of this study is to enhance the hardenability and the mechanical properties by the addition of alloying elements such as Ni, Cr, Mo and B for the development of Cr-Mo plastic mold steel with uniform hardness and microstructure. The ingots were prepared by vacuum induction melting and forged to ${\Phi}35mm$ round bar. Forged bars were quenched and tempered at $200{\sim}600^{\circ}C$ for 1.5 hour. Jominy test, boron distribution observation, microstructual observation, tensile test and charpy impact test were conducted. It was confirmed that the hardenablity of these steels was improved by increasing of alloying elements and further promoted by the addition of boron. The critical rate of cooling required to obtain the bainitic structure for 0.27C-1.23Cr-0.28Mo-B steel was $0.5^{\circ}C/sec$. Hardness and strength of Cr-Mo steels decreased with increasing tempering temperature, but elongation and reduction of area increased with increasing tempering temperature. However, impact energy tempered at $400^{\circ}C$ showed the lowest value in the range $200{\sim}600^{\circ}C$ due to the temper embrittlement.

• The Transactions of the Korean Institute of Electrical Engineers B
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• v.48 no.1
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• pp.27-33
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• 1999

Compact fluorescent lamps are very sensitive to the variation of ambient temperature. This paper investigates the temperature characteristics of a 15[W] compact fluorescent lamp, and compensates the variation of light output by frequency control of its electronic ballast. Circuit parameters for the inverter of the electronic ballast are obtained by analyzing the R-L-C equivalent circuit for the inverter and the lamp. The optimum ratio of the two capacitance($C_1$/$C_2$), which are connected with the lamp in series and in parallel, respectively, is determined which consideration of the temperature variation within a range of 10~35[$^{\circ}C$]. As a result a value of 10 for the ratio is obtained at an operating frequency of 57[kHz], and with this value the frequency control works well for temperature compensation. Its validity is verified by investigating light output stabilization characteristics resulting from frequency control of the lamp at various temperatures.

• Korean Journal of Materials Research
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• v.27 no.7
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• pp.359-363
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• 2017

The resistance of metallic materials to ballistic penetration generally depends on a number of parameters related to projectile, impact, and armor plate. Recently, armor materials have been required to have various properties such as hardness, strength, and impact toughness in order to maintain an excellent ballistic resistance even after impact. In the present study, the influence of tempering on the microstructure and mechanical properties of an ARMOX 500T armor steel plate was investigated and then compared with those of S45C and SCM440 steels. As the tempering temperature increased, the hardness and strength gradually decreased, whereas the ductility and impact toughness clearly increased because the hardness, tensile, and impact properties were affected by the microstructural evolution and precipitation occurring during tempering. On the other hand, temper embrittlement appeared at tempering temperatures of 300 to $400^{\circ}C$ for the impact specimens tested at low temperature.