Effect of Ultrasonic Melt Treatment on Solidification Microstructure of Al–5Ti–1B Alloy Containing Numerous Inoculant Particles

Soo‑Bae Kim,Jae‑Gil Jung,Young‑Hee Cho,Su‑Hyeon Kim,Kwangjun Euh,Jung‑Moo Lee 대한금속·재료학회 2022 METALS AND MATERIALS International Vol.28 No.7

The effect of ultrasonic melt treatment (UST) on the solidification microstructure of an Al–5Ti–1B alloy containing highvolumefractions of Al3Tiand TiB2particles is investigated for various UST times with different melt holding times. Theas-cast Al–5Ti–1B alloy is composed of TiB2and polygonal Al3Tiparticles (present prior to UST), plate-like Al3Tiparticles,and Al grains (formed during UST and/or solidification). The UST causes a size reduction and homogeneous distributionof the TiB2-agglomerated region containing many submicron-sized TiB2particles pushed to the grain boundaries. The USTslightly decreases the size and improves the distribution of polygonal Al3Tiparticles enriched in the TiB2-agglomeratedregion. Unlike the TiB2and polygonal Al3Tiparticles, which exhibit a minor refining effect, the plate-like Al3Tiparticlesshow a significant refinement with UST application. The UST has a significant effect on the size distribution of Al grains byinducing the formation of medium-sized grains at the expense of small and large grains; however, it only has a slight effecton grain refinement. The degree of microstructure modification increases with increasing UST time but decreases with meltholding time after UST. The mechanisms for the refinement and dispersion of the TiB2and Al3Tiparticles and Al grains arediscussed considering fragmentation, nucleation, and growth behaviors induced by the UST and subsequent solidification.

위 윤상근 세포의 Ca^2+-의존성 K^+-전류에 미치는 Ascorbate의 효과

배정원,이무열,방효원,엄대용,이상돈 중앙대학교 의과대학 의과학연구소 1991 中央醫大誌 Vol.16 No.2

In order to observe the effect of ascorbate on the Ca^2+-activated K^+ current in pyloric circular muscle cells which plays a critical role in generation and maintenance of repolarization and automatism, apart of pyloric circular muscle tissue was excised out, digested in collagenase containing Ca^2+-free physiological solution to get single circular muscle cells and the whole cell mode of patch-clamp experiment was conducted. Following results were obtained : 1. Oscillatory outward current was reduced by ascorbate in case of high intrapipette Ca^2+ concentration in whole voltage range and was enhanced in case of low intrapipette Ca^2+ concentration. 2. Oscillatory outward current was reduced in Ca^2+-free physiological solution with calcium channel blocker and not effected by ascorbate. 3. There were no qualitative differences among the control and ascorbate-treated group in effects of pH, steady state inactivation and the remaining component of the outward current. The above results could be concluded that ascorbate effects calcium-dependent component of the oscillatory outward current in the pyloric circular smooth muscle cells.

賃金滿足의 決定要因에 관한 硏究

裵武煥,金榮載 관동대학교 경영경제연구소 2002 경영논집 Vol.21 No.-

조직에 있어서 임금배분의 문제는 중요한 행동적 영향력을 갖게 되는데, 임금은 금전적 보상으로서 조직의 가장 중요한 비용항목이며 근로자에게는 생계를 위한 주요 수입원이다. 임금은 사회적 신분이나 경제적 지위를 규정할 뿐만 아니라 직무만족이나 동기유발의 중요한 요인이다. 효율적인 임금관리를 위해서는 종업원들이 임금의 도구성을 어떻게 지각하고 있는지 또 임금이 종업원들의 태도나 행동에 어떠한 영향을 미치는지에 대한 연구가 필요하다. 본 연구는 "D"시에 소재하는 금융기관 종사자들을 대상으로 하여 임금만족을 결정하는 요인이 무엇인지를 조사하고, 실증분석하여, 임금만족과 직무만족과의 상관관계를 규명하여 효율적인 임금관리에 중요한 시사점을 제시하였다.

企業倫理와 倫理綱領의 實踐方案에 관한 硏究

裵武煥 관동대학교 기업경영연구소 1998 경영논집 Vol.17 No.-

심비디움 모자이크 바이러스의 핵산과 외피단백질에 관한 연구

배소현,장무웅 嶺南大學校 基礎科學硏究所 1994 基礎科學硏究 Vol.14 No.-

심비디움의 잎에 괴저 줄무늬 증상주에서 분리한 심비디움 모자이크 바이러스(CyMV-K)를 카틀레야와 팔레높시스에 증식시켜 순화 시료로 하였다. 순화된 CyMV-K는 길이 480-500nm, 폭 13nm의 약간 완곡형의 사상입자였다. 순화된 CyMV-K 시료의 자외선 흡광도를 조사한 결과, 260nm에서 최대, 248nm에서 최소값을 나타내는 전형적인 핵단백질의 자외선 흡수곡선을 보였다. Phenol/chloroform 추출에 의해 정제된 CyMV-K RNA의 분자량은 6.45Kb로 측정되었다. CyMV-K coat protein의 분자량 측정을 위해 SDS-PAGE법으로 전기영동한 결과, 분자량은 약 2.51 x 10⁴ 달톤으로 확인되었다. CyMV-K, CyMV-A, CyMV-J를 한천겔 이중확산법과 면역전자현미경법으로 혈청학적 관계를 조사한 결과, 혈청형이 거의 동일하였다. Cymbidium mosaic virus(CyMV-K) from Cymbidium sp, showing necrotic stripe symptom on the leaves was multiplied in Cattleya sp, and Phalaenopsis sp, and then purified. The purified CyMV-K was slightly flexible particles which have lengths in the range of 480-500 nm and widths of 13 nm. Ultraviolet absorption pattern of purified CyMV-K indicated the maximum at 260 nm and minimum at 248 nm, which was typical pattern of viruses. The molecular weight of CyMV-K RNA prepared by the extraction of phenol/chloroform was about 6.45 Kb. The molecular weight of CyMV-K coat protein estimated by SDS-PAGE method was about 2.51 x 10⁴daltons. CyMV-K, CyMV-A, CyMV-J was seorlogically identical by means of agar gel double diffusion test and immunosorbent electron microscopy.

닭에서 오존수의 급여가 닭와포자충 감염에 미치는 영향

박배근,染谷梓,류시윤,김현수,조성환,전무형,손화영 충남대학교 수의과대학 동물의과학연구소 2001 動物醫科學硏究誌 Vol.9 No.-

Ozone is very effective in acute and chronic viral disease as a virucidal agent and in improving the general health of the animals. The effects of ozonized water supply against Cryptosporidium baileyi was studied in 2-day-old chicken. After oral inoculation of chicken with 1×10^6 oocysts, ozonized water(0.5ppm) and tap water were supplied to experimental and control group, respectively. The prepatent period of both group was 6 days postinoculation(PI). The patent period of experimental group was shorter(6-18 days) than that of control group(6-22 days). The number of oocysts in the feces were maximum on days 11 PI, indicating 1.99×10^6 oocysts/experimental chicken and 6.00×10^6 oocysts/control chicken. The number of discharged oocysts during experimental period was higher in control group than that of experimental group. In the view of febric bursa sections on 7 days PI, the number of endogenous development of C baileyi was smaller in experimental group that in control group. This results indicate that the autoinfected sporozoite were damaged by ozone. The ozonized water supply to chickens is alleviation cryptosporidiosis.

웹을 이용한 회계정보의 공시와 과제

박무현,배주한 계명대학교 산업경영연구소 2000 經營經濟 Vol.33 No.2

Recent trends to disclose accounting information on the web require information systems that integrate accounting information and information technology. Korean companies do not provide material accounting and related information on a real-time basis while those in advanced countries do. This study reviews changes in information technology, and the web as an alternative means of disclosing financial information. First, effects of changes in information environments on the information network and on the discipline of accounting are reviewed. Second, a new system under developments in U.S.A. and in Korea, i.e., disclosure of accounting information on an intranet-web basis, are compared. Also discussed are limitations of the new system and solutions. In summary, disclosure of accounting information on the cyber space will become a part of accounting systems in the near future and active discussions about related issues are in order.

마우스에서 오존수의 급여가 쥐와포자충 감염에 미치는 영향

박배근,김덕환,류시윤,김현수,조성환,전무형 충남대학교 수의과대학 동물의과학연구소 2000 動物醫科學硏究誌 Vol.8 No.-

Ozone is very effective in acute and chronic viral disease as a virucidal agent in reversing positive antibody tests and in improving the general health of the animals. The effects of ozonized water supply against Cryptosporidium muris was studied in 5-weeks-old mice. After oral inoculation of mice with 1×10^6 oocysts, ozonized water(0.5ppm) and tap water were supplied to experimental and control group, respectively. The prepatent period of both group was 8 days postinoculation(PI). The patent period of experimental group was longer(62days) than that of experimental group(57days). The number of oocysts in the feces were maxium on days 28 PI, indicating 3.54×10^6 oocysts/experimental mouse and 5.56×10^6 oocysts/ control mouse. The number of discharge oocysts during 12-33 PI was more in control group than that of experimental group. In the view of gastric gland section on days 28 PI, the number of endogenous development of C muris was smaller in experimental group than in control group. This results indicates that the autoinfected sporozoite were damaged by ozone.

병아리에서 닭와포자충에 의한 F-낭염이 SRBC에 대한 항체형성에 미치는 영향

박배근,사또시, 가바모도,전무형,김무강,류시윤 충남대학교 수의과대학 동물의과학연구소 1996 動物醫科學硏究誌 Vol.4 No.-

병아리에 닭와포자충(Cryptosporidium baileyi)의 감염에 의한 F-낭염이 면양 적혈구(SRBS)에 대한 항체 형성에 미치는 영향을 관찰하기 위하여 2일령의 병아리에 닭와포자충의 오오시스트 1 × 10^6개를 경구 접종하였다. SRBC를 경정맥 및 F-낭의 관강에 감작하고 항체형성능과 F-낭의 조직소견을 1 주일 간격으로 10주간 관찰하여 다음과 같은 결과를 얻었다. 1. 체중의 증가율은 실험 전 기간을 통하여 전반적으로 실험군이 대조군 보다 낮았다. 2. F-낭 지수(Bursa index)는 1주령 부터 5주령 까지는 1이하로 위축되었으며, 6주령 부터 1이상으로 종창되었다. 특히, 6주령의 경우 1.94로 종창의 정도가 가장 심하였다. 3. 상피세포에서 발육하고 있는 닭와포자충의 오오시스트 및 점막하직과 여포내의 호산구의 침윤은 1주령에서 4주령 까지 관찰되었으며 1주령에 가장 많은 오오시스트가 상피에서 관찰되었다. 4. 상피세포 및 FAE의 핵융해, 비만세포의 출현, 여포의 괴사 및 상피의 증생은 5주령 이후에 관찰되었다. 상피세포의 핵융해는 6주령에 가장 심하였다. 5. HA titer는 정맥내로 항원을 감작한 군에서 7주령에 최고의 역가를 보였으며 대조군이 64±35, 실험군이 44.8±15.7이였다. F-낭의 관강내로 항원을 감작한 군에서는 8주령에 대조군이 11.2±3.9, 실험군이 2.8±1.0로 실험군의 역가가 모두 낮았다. 이상의 결과로 볼 때 닭와포자충의 감염에 의한 F-낭염(bursitis)은 SRBC에 대한 항체형성능을 저해The 함을 알 수 있다.

아세토니트릴 용매 중에서 Copper-1,5,9,13-Tetrathiacyclohexadecane 착물의 전기화학적 거동과 그 분석적 응용

徐戊龍,李富永,崔明子,裵俊雄,朴泰明 慶尙大學校 기초과학연구소 1992 基礎科學硏究所報 Vol.8 No.-

비수용매인 아세토니트릴 중에서 Cu(Ⅱ)dhk 1,5,9,13-tetrathiacyclohexadecane[16-ane-S_4]의 착물에 대한 전기화학적 거동으로서 직류폴라로그램과 미분펄스폴라로그램으로부터 환원전류의 유형과 가역성을 조사하고, 이들 화합물의 분석적 응용으로서 수용액에 있는 Cu(Ⅱ) 이온을 염석추출법으로 정량하였다. 또한 아세토니트릴 용매 중에서 착물의 안정도상수를 구하고, 분석적 응용으로 수용액 중의 Cu(Ⅱ)를 염석추출법으로 정량하기 위하여 추출 조건 곧 킬레이트와 염석제의 효과, pH 범위를 구하고 또한 Cu(Ⅱ)이온을 정량하는데 있어서의 검량성과 공존이온 효과를 조사하였다. 실험결과로부터 환원 과정은 비가역적이었으며 환원전류는 확산지배적임을 알았다. 또한 아세토닐트릴 용매 중에서 착물의 log K_f 값은 3.51이었으며 Cu(Ⅱ) 이온을 정량하는데 있어서 공존하는 이온의 영향을 별로 받지 않아 선택성이 좋았으며 본 실험방법에 의한 정량한계는 60ppb 이었다. The electrochemical behaviors and analytical application of copper-1,5,9,13-tetrathiacyc-lohexadecane[16-ane-S_4] complex in acetonitrile(AN) solution have been investigated by the use of Dc polarogaphy and differential pulse polarography. Thus the formation constant of copper complex was 10^3.51. Copper (Ⅱ) ion was found to form complex of 1-to-1 composition with [16-ane-S_4]. In addition, reduction step was irreversible and the reduction current was diffusin controlled. And the effect of concentration of the salting-out reagent and chelating agent and pH of aqueous phase on the determination of copper(Ⅱ) was investigated and diverse ion effect was discussed. By salting-out extraction technique, we can be determined until the concentration of cooper (Ⅱ) of 60 ppb.