• 보존과학연구
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• 통권20호
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• pp.91-120
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• 1999

This paper presents the results of investigation on crystal, firing temperature and trace elements analysis of fragments 4~8 centriesexcavated from Kyong ju historical sites such as Wang kyong,Walsung, Hwangnam great tomb by application of optical microscope, neutron activation analysis and X-ray diffraction. Temper analysis of clay for identification of local or foreign production; Trace elements is not presented a unique chemical composition. That’s data have to be treated a statistical process in order to normalize. The results followed ;(1) Firing temperature could be estimated $700^{\circ}C$ on some softness pottery at Walsung and most of hardness others are $1,000^{\circ}C$ to $1,200^{\circ}C$.(2) Crystal structures are divided into three kinds of mineralogical composition(Quartz, Mullite, Feldspar).(3) Considering of the results of statistical data, chemical composition of Walsung is more similarly Wang kyong than Hwangnam great tomb.

• Journal of Welding and Joining
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• 제7권2호
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• pp.49-59
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• 1989

The effect of non-metallic inclusions on the HAZ hydrogen induced cracking was investigated. Quench and temper high tensile strength steels containing various sulphur contents were employed. The sulphur contents range between 0.007% and 0.040%. Non-metallic inclusions were mainly MnS type sylphide and Mn-Al-Si type. The sensitivity of HAZ delayed cracking was evaluated by implant testing. Diffusible hydrogen content was varied by controlling the moisture absorbing condition of manual arc welding electrodes. The one was asreceived condition, the other was dipping the electrodes in the water for ten minutes. The main results obtained were as follows; 1) The results of implant test showed that critical stress increased with increasing S content up to 0.013%. But steel containing 0.040%S showed lower critical stress than that of 0.013% S. These result suggest that there will be optimum S content to prevent HAZ delayed cracking of high strength steels. 2) Under the lower D.H.C. level, critical stress was increased with rolling reduction, but higher D.H.C. level, effect of rolling reduction was not recognized.

• 동의생리병리학회지
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• 제25권2호
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• pp.163-175
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• 2011

This study is a bibliographic search about completion and maintenance of pregnancy. In oriental medicine, there is a proper temper and appearance that encourages optimal pregnancy. Invigoration of sperm is important for males to have descendants, and regulation of menstrual disturbances is necessary for female to have descendants. It is not good for both male and female to engage in sexual intercourse too often. Male and female shall have sexual intercourse. When they feel the connection, mind and body are sound, weather is fine, and they take position at ease. Previous studies on pregnancy describe minutely process of fetus's growth until the fifth month, and suggest the rules of fetus's health according to fetal development. Therefore, it is important to prevent acquiring diseases during pregnancy. Female needs to be careful and restful in the early stage of pregnancy. In the late period of pregnancy, she needs to be active.

• 열처리공학회지
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• 제3권2호
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• pp.32-36
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• 1990

For the accurate measurements of hardness in a material, it is necessary to have a thorough understanding of the effects of test variables on the accuracy of hardness value. For the rebound hardness test, major test variables are the radius of hammer ball tip, type of backing materials, size and roughness of the specimen. In this study, effects of these variables on Equo-Tip hardness value were investigated. Hardness measurements were carried out using WC balls with various sizes of worn-ot zone. The sample materials chosen for the experiments were commercial standard hardness blocks and SM45C steel bars subjected to either normalization or quench and temper treatments. As backing materials, aluminum, steel and rubber plates were used in all the experiments. Experimental results show that for the accurate measurements of Equo-tip hardness, it is necessary to use the hammer ball with a worn-out zone parameter of less than 0.23, and the recommended minimum thickness and width of the specimen are 25mm and 70mm, respectively. Further for the surface preparation, the specimens need to be polished with an emery paper of No. 400 or finer, and for the backing matrials, it is recommended to use steels or rubbers.

• Journal of mucopolysaccharidosis and rare diseases
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• 제5권1호
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• pp.29-33
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• 2021

Prader-Willi Syndrome (PWS) is a neurodevelopmental genomic imprinting disorder involving a lack of gene expression from the paternal chromosome 15q11-q13 region. This is typically due to paternal 15q11-q13 deletions (in approximately 60% of cases), maternal uniparental disomy 15, or when both 15s are from the mother (about 35% of cases). An imprinting center controls the expression of imprinted genes in the chromosome 15q11-q13 region. PWS is a neurodevelopmental disorder characterized by mental retardation and distinct physical, behavioral, and psychiatric features. Characteristic behavioral disturbances in PWS include excessive interest in food, skin picking, difficulty with a change in routine, temper tantrums, obsessive and compulsive behaviors, and mood fluctuations. Individuals with PWS typically have intellectual disabilities (borderline to mild/moderate mental retardation) and exhibit a higher overall level of behavior disturbances compared to individuals with similar intellectual disabilities. This condition severely limits social adaptations and quality of life. Different factors have been linked to the intensity and form of these behavioral disturbances, but there is no consensus regarding the cause. Consequently, there is still controversy surrounding management strategies and there is a need for new data. PWS is a multisystem disorder. Family members, caregivers, physicians, dieticians, and speech-language pathologists all play an important role in the management and treatment of symptoms in an individual with PWS. Here we analyze behavioral problems in children and adults with PWS by age and review appropriate management and treatment strategies for these symptoms.

• 동의생리병리학회지
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• 제16권1호
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• pp.201-208
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• 2002

The measurement parameter of QiguㆍInyoung pulse diagnosis distinguishes the excess, deficiency and quick-temper of pulse through relative comparison of Qigu and Inyoung. We have estimated the relationship between measurement of QiguㆍInyoung pulse wave detection system and measurement of manual pulse diagnosis by means of quantifying pulse peak and Inyoung/Qigu index. The results can be summarized as follows : When standardizing manual pulse diagnosis measurement was standardized, Inyoung index of machinery measurement was more significantly correlative with the index of manual pulse diagnosis than Qigu index of machinery measurement. The ratio of Inyoung/Qigu magnitude with machinery measurement was doser to manual pulse diagnosis than that of Qigu and Inyoung pulse magnitude measured separately. A linear proportion relationship was found between measurement of QiguㆍInyoung pulse wave detection system and measurement of manual pulse diagnosis. It was necessary to adjust the output signal of pulse in order to estimate the exact relationship between measurement of QiguㆍInyoung pulse wave detection system and measurement of manual pulse diagnosis.

• 한국결정성장학회지
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• 제1권1호
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• pp.92-99
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• 1991

$Si(OC_2H_5)_4$ 로부터 $SiO_24$ 미립자를 얻는 반응은 가수분해반응과 종합반응의 두 단계로 이루어지며 중합반응은 $Si(OC_2H_5)_4$의 농도에 대하여 1차 반응이었다. 중합반응의 반응속도상수는 물의 농도와 촉매의 농도가 증가할수록 그리고 반응온도가 높아질수록 커지는 경향을 나타내고 있다. 생성된 실리카의 직경은 $0.06-0.27\mu\textrm{m}$이었으며 직경은 $Si(OC2H5)4$의 초기농도가 작아질수록 온도가 시간에 따라 입자가 성장해가는 속도는 전화율의 함수로 d=a.ln(Xa)+b 의 형태로 나타낼 수 있으며 최종 실리카의 직경은 사수 b값에 접근하였다.

• 열처리공학회지
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• 제29권3호
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• pp.113-123
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• 2016

In the present work, we investigated the effects of the carbon potential on the formation of carbide at the carburized surface and anti-pitting fatigue strength in the supercarburized steels. Two low carbon steels with different Cr concentrations were adopted and the repeated supercarburizing treatment carried out with the different carbon potential conditions. The microstructure and carbides at the supercarburized surface were observed by using optical microscope and scanning electron microscope. The microhardness test was performed and the hardness distribution and the effective case depth at the supercarburized surface were discussed. The roller pitting fatigue test was carried out and the fatigue strength was evaluated with different the carbon potential conditions. The microstructure of the fatigue specimen surface was observed by means of scanning electron microscope and scanning transmission electron microscope. Depending on the chemical composition of the steels and the carbon potential condition, the resistance of temper softening and pitting failure was influenced due to the carbide distribution and the formation of coarse network carbide. Thus, it was confirmed that the control of the carbide formation is a key factor to improve the anti-pitting fatigue strength in the supercarburized steels.

• 대한기계학회논문집
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• 제7권4호
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• pp.425-433
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• 1983

Fatigue tests by axial loading (R=0.1) were carried out to investigate fatigue crack growth properties of small surface cracks in mild steel at room temperature, 250.deg. C and 400.deg. C, by using flat specimens with a small artificial pit. All the data of the fatigue crack growth rate obtained in the present tests are determined as a function of the stress intensity factor range, so that the applicability of liner fracture mechanics to the fatigue crack growth of surface cracks at elevated temperatures is investigated and discussed in comparison with the data of type 304 stainless steel at room temperature and elevated temperature. The obtained results are as follows: 1) Relations of both surface fatigue crack length and its depth to cycle ratio fall within a narrow scatter band in spite of different stress levels. 2) The .DELTA. .sigma. .root. .pi. a-da/dN relation of surface fatigue crack growth at room temperature is independent of the stress level and can be plotted as a straight line at log-log diagram, but the relation at 400.deg. C depends partly on the stress level. 3) Relations of the fatigue crack growth into depth d(2b)/dN and is stress intensity factor range .DELTA. $K_{I}$, accounted for the aspect ratio variation, fall within a narrow scatter band for wide range of the applied stress levels. And .DELTA. $K_{I}$E-d(2b)/dN relations of mild steel at different stress level coincide relatively well with the data of type 304 stainless steel. 4) The value of aspect ratio obtained by a beach mark method and a temper coloring method approaches about 0.9 in common with crack growth and it is independent of stress level and temperatures. 5) The equi-crack length curve is parallel to S-N$_{f}$ curve at elevated temperatures.s.s.s.

• 대한기계학회논문집
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• 제14권1호
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• pp.157-171
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• 1990

본 연구에서는 저탄소강 판재가 소성변형을 하면 열확산계수가 변화하는가를 구명하려는 것이다. 재료의 소성변형은 압연법을 이용하며, 고온압연, 열간압연 및 냉간압연법으로 재료를 제작하여, 압연률을 변화시키면서 압연방법 및 압연률에 따르 는 변화를 규명하려 한다. 열확산계수의 측정은 레이저 섬광법으로 하며 온도를 실 온에서 500.deg. C 근처까지 변화시키면서 측정한다.