Analysis of the Effects of Al on the Ductile-to-Brittle Transition Behavior of Ferritic Heat-Resistant Stainless Steels

Yingbo Zhang,Dening Zou,Xiaoqiao Wang,Fengshe Xia,Yong Wang,Wei Zhang 대한금속·재료학회 2022 METALS AND MATERIALS International Vol.28 No.7

The effect of Al content on the microstructure and ductile-brittle transition temperature (DBTT) of 18Cr–Al–Si ferritic heatresistantstainless steel have been studied by Charpy impact testing over temperatures ranging from 20 to 90 ℃. Charpy impacttest results show that DBTT increased with increasing Al content. Meanwhile, fracture morphology changed with increasingAl content, where the amount of dimples decreased and cleavage facets increased, indicating increases in the tendency forbrittle fracture. Furthermore, ferrite grain size, volume fraction and size of (Cr, Fe)23C6 carbides increased with increasingAl content, which led to decreasing toughness and increasing DBTT.

한국인에서 Quadruplex PCR을 이용한 8종류 상염색체 STR 유전좌의 다형성 분석

장영길,김기범,신창호,이숭덕,이윤성,이정빈 大韓法醫學會 2001 대한법의학회지 Vol.25 No.1

Two quadruplex PCR reactions were designed for 7 tetrameric (D3S2406, D4S2368, D5S818, D7S821, D9S925, D13S317, D19S253) and one trimeric (D6S1043) short tandem repeats loci to study the allele frequency and the applicability of genetic variation in these loci in forensic case works. For 310 unrelated Koreans DNA was isolated from peripheral blood using phenol/chloroform method. Quadruplex I was consisted of D4S2368, D6S1043, D7S821, D9S925 and quadruplex II D3S2406, D5S818, D13S317, D19S253. The amplified products were analyzed by 5% polyacrylamide gel electrophoresis followed by silver staining. The heterozygosity in each loci ranged 92.91-66.13%, and PD(Power of Discrimination) was above 085 in each loci. Every loci except D6S1043 followed hardy-Weinberg expectation. The cumulative PI was low as 1.65×10-10. Two mutations were noted, one in D19S253 and the other in D9S925 among 234 gametes. With these results above eight STR loci studied here preyed to be highly polymorphic enough to be used in forensic field. This study provides valuable population data in these loci for Korean.

알데히드탈수소효소 2(ALDH2) 및 CYP2E1 유전자 다형성에 따른 요중 뮤콘산 농도와 요중 8-hydroxydeoxyguanosine과의 관련성

김용대,강종원,엄상용,장연위,김성훈,김은영,이철호,문재동,김헌 대한산업의학회 2007 대한직업환경의학회지 Vol.19 No.2

음향방출 신호분류에 의한 SM45C 시효처리재의 인장변형 해석

이장규,우창기,김용배 한국공작기계학회 2009 한국공작기계학회 춘계학술대회논문집 Vol.2009 No.-

This study investigates tensile deformation of the stress aging heat-treated SM45C steel which are aging temperature at 250, 300℃, aging time at 1,3 hours, and applied load at 300, 400N conditions by using acoustic emission (AE). A signal processing technology used to evaluate an AE source characterization by 2 AE measurement systems, i.e., DiSP & PCI-2 AE hardware and AEwin™ software. In this study, most suitable aging condition appeared at 250℃, 3 hours and 300N. On the other hand, in case of 250℃, 3 hours, 400N and 300℃, 3 hours, 400N conditions, yield load decreased than other conditions according to the over-aging phenomena. Especially, In case of 300℃, 3 hours and 400N condition appeared AE energy in elastic limit fairly high than non-heat treatment specimen.

정신분열병 환각의 횡문화적 연구 : 상해와 서울의 비교 A Transcultural Study

金光日,長良棟,陸明康,朴康奎,朴容千,金大虎 大韓神經精神醫學會 2001 신경정신의학 Vol.40 No.5

연구목적 : 정신분열병의 환각이 문화사회의 특성에 따라 어떤 차이가 나는지를 확인하고 그 의미를 문화정신의 학적 견지에서 고찰해보고자 이 연구를 시행하였다. 방 법 : Shanghai와 서울의 정신분열병 환자를 대상으로 환각의 형태, 내용, 주제 등에 관한 비교문화적인 조사연구를 하였다. Shanghai Mental Health Center, 국립서울정신병원, 한양대학교병원에 입원하고 있는 환자중 DSM-Ⅳ 진단기준으로 정신분열병의 진단이 확정된 환자 가운데 입원한지 1개월에서 6개월 이내인 환자를 대상으로 사전에 성별, 연령, 교육연한, 발병기간 임상아형, 등 5개 변인을 통제하여 조사대상을 선정하였다. 조사대상이 된 환자는 396명(Shanghai 182명, 서울 214명)이었다. 이중 환각이 확인된 환자 231명(Shanghai101명, 서울 130명)을 최종 연구대상으로 하였다. 결 과 : 환각의 형태에서는 양 집단 차이가 없었으나 환각의 내용이 양 집단에서 차이를 보였다. 즉 Shanghai에서는 정치적인 내용이, 서울에서는 초자연적/종교적 내용이 많았다. 결 론 : 환각의 주제나 내용은 망상과 긴밀하게 연관이 되어 있다는 점, 그리고 사회문화적 상황의 영향을 다분히 받고 있음을 알 수 있었다. Objective : The types, contents and major themes of schizophrenic hallucinations in Shanghai and Seoul were compared for evaluating cultural differences and connotation. Methods : Among the schizophrenic inpatients of Shanghai Mental Health Center in Shanghai and National Seoul Mental Hospital and Hanyang University Hospital in Seoul, 396 cases(182 cases in Shanghai, 214 cases in Seoul) were selected by two ways: a) five staged stratified random sampling of sex, age, education, clinical subtype and onset year, b) cases who have admitted for one to six months in their last admission. Among them, 231 cases(55.39% in Shanghai, 60.83% in Seoul) confirmed to have hallucinations were the final subjects of study. Results : Frequencies in types of hallucination were not different between the two groups. However, contents and major themes were different: Political themes and related contents were dominant in Shanghai cases, and supernatural and religious themes and related contents were dominant in Seoul cases. Conclusion : It was concluded that contents and themes of hallucinations were closely related to the delusional contents and themes, and such patterns were considerably influenced by so-ciocultural characteristics.

한국인에서 DXS7132 유전좌와 GATA31D10 유전좌의 다형성에 관한 연구

안종성,장영길,이숭덕,신창호,이윤성,이정빈 大韓法醫學會 2000 대한법의학회지 Vol.24 No.1

The validation study for two STR loci on X-chromosome, DXS7132 and GATA31D10, was done including allelic distribution and frequency of each allele to use these results for individual identification and paternity testing. For 496 unrelated Koreans, above two STR loci were amplified simultaneously using duplex PCR amplification method. The amplified products were analyzed by polyarylamide gel electrophoresis followed by silver staining. In male DXS7132 locus revealed 7 different alleles ranging from 276bp to 300bp. The largest allele was consisted of 14 repetition of [TCTA] unit and took 0.3417. The allele 15 followed next as 0.3165 and allele 13 as 0.1726. In female general distribution was same except one allele, allele 18 was found additionally. The heterozygosity was 0.7706 and 23 different genotypes were found. Polymorphism information content(PIC) was 0.727. Two cases of mutation were noted in DXS7132 locus In both male and femal 7 different alleles were noted in GATA31D10 locus and the alleles ranged from 195bp to 231bp. The allele 15(199bp) took the majority of all as 0.825. The other alleles showed rather relatively low frequency. The heterozygosity was 0.2385 and 11 different genotypes were found. PIC was 0.2521, and no mutation was noted in GATA31D10 locus. Considering these two loci together, 22 different halpotype were noted.

요천추부 신경근의 체온절

김영수,조용은,장호열 대한신경외과학회 1995 Journal of Korean neurosurgical society Vol.24 No.1

Thermography shows the skin temperature changes in various conditions of the body. The skin temperature varies according to subcutaneous blood flow under the control of autonomic nervous system Lumbar radiculopathy due to disc herniation makes difference in the temperature of lower extremities caused by the changes in general function and autonomic functions of the nerve root. Digital infrared thermographic imaging(DITI) system has been used to diagnose radiculopathy without any hazards or discomforts and shows the pain due to LDH by objective change of temperature. This study has used DITIs of 55 control cases and 217 cases of LDH patients and analysed it statistically. In the room of temperature stable at 20℃, the temperature distribution of the lower extremities of the control cases ranged from 24.9℃ to 29.9℃. The significant minimal temperature difference between right and left lower extremities range from 0.1℃ to 0.4℃. The more distal, the greater the temperature difference was. The thermatome of L4. L5 and S1 was drawn in radiating type and spot type. The thermatome showed larger area than the sensory dermatome and sympathetic dermatome. There was significant increase or decrease of temperature in thermatome in LDH patients. In conclusion, preoperative DITI of the LDH patient can be helpful for diagnosing the level do LDH and the areas of pain.

활성화 수피를 이용한 중금속 흡착제 개발

박창진,양재의,유경열,장용선,김원일 한국환경농학회 2004 한국환경농학회지 Vol.23 No.4

The objective of this research was to develop the adsorbent for heavy metals by activating the bark sample. Barks from pine tree with diameters of 2~4 mm were activated in the muffle furnace under a high relative humidity condition at temperatures of 600~900℃. The removal efficiency of the activated bark (ACTBARK) for Cu and Cd was temperature dependent showing the order of 900℃ > 800℃ > 700℃ > 600℃. The critical temperature was considered to be 900℃ to become an efficient adsorbent for Cu and Cd. The bark samples activated at temperatures lower than 700℃ showed a less removal efficiency than the crude bark The ACTBARK activated at 900℃ removed more Cu and Cd from solution than the commercial activated carbon and charcoal. The ACTBARK (activated at 900℃) adsorbed all of the Cu and Cd in solution with concentrations less than 150 mg/L. The selectivity of the ACTBARK was in the order of Cu>Zn>Ni>Pb>Fe>Cd>Mn.

A Single Chord Localization Algorithm for Wireless Sensor Networks

Yong-Luo Shen,Yuan Zhang,Yu-Ping Hu,Jun Zhang 보안공학연구지원센터 2015 International Journal of Grid and Distributed Comp Vol.8 No.1

This paper presents a novel range-free single chord localization algorithm with low energy consumption and high accuracy for wireless sensor networks. A mobile anchor node and a mobile reference node are employed to periodically broadcast beacon messages and reference messages, respectively. Each sensor node is equipped with a received signal strength indicator for comparing the signal strength. By using the edge function and the result of comparing signal strength, each sensor node only needs one chord on the communication circle for localization. Compared with previous approaches that require multiple chords, less beacon messages are required by the sensor nodes. In the proposed algorithm, the localization error mainly depends on the move distance interval. However, for the other approaches, large localization errors can be observed according to the angle between chords which may descend the localization accuracy dramatically. Analysis results indicate that the proposed algorithm is superior to other approaches in energy consumption and localization accuracy.

A ppb-Level Formaldehyde Gas Sensor Based on Rose-Like Nickel Oxide Nanoparticles Prepared Using Electrodeposition Process

Yong Zhang,Long-Zhen Xie,Chao-Xin Yuan,Chun-Lin Zhang,Su Liu,Ying-Quan Peng,Hai-Rong Li,Miao Zhang 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2016 NANO Vol.11 No.1

In this study, rose-like nickel oxide nanoparticles (diameter of 400–500 nm) were prepared on indium tin oxide (ITO) glass substrates by a simple electrodeposition in NiSO4·6H2O solution. Scanning electron microscopy (SEM), X-ray diffraction (XRD) and transmission electron microscope (TEM) were used for analysis of the NiO nanoparticles. The effects of operating temperature on the sensor response and the response versus gas concentration properties of the NiO nanorose-based sensors were investigated. We determined the operating temperature of the gas sensors to be 230℃, considering the proper sensitivity and a rapid response. In addition, gas-sensing characteristics of rose-like NiO nanoparticles to formaldehyde were investigated. It was shown that the sensors exhibited good response (Rg/Ra = 3.43) properties to formaldehyde gas at 230℃, making them to be promising candidates for practical detectors to formaldehyde gas.