http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
A7003 합금의 환경친화적 압출공정을 위한 Mg조성 및 공정비교 연구
조훈,조형호,한명근,김영직 한국전과정평가학회 2002 한국전과정평가학회지 Vol.4 No.1
최근 수송기계 경량화 추세에 부응하여 door impact beam, seat side rail 및 hood support와 같은 자동차 부품등에 Al-Mg-Zn계 중경질 A7003 합금소재의 적용이 검토되고 있는 실정이다. 그러나 이들 합금소재의 적용을 위해서는 제품의 용도와 특성을 만족함과 동시에 압출성이 높은 합금소재의 개발이 선행되어야 한다. 본 연구에서는 A7003 합금소재의 압출성을 향상시키기 위하여 합금원소 첨가량이 미세조직, 압출성 및 기계적 특성에 미치는 영향을 조사하였다. Mg조성 제어에 의해 기계적 강도의 저하없이 A7003 합금의 압출성을 향상시킬 수 있었다. 또한 MLCA 기법을 적용하여 A7003 합금중의 Mg 첨가량 및 빌렛가열공정 변화에 따른 에너지 소비량 및 환경오염부하물질 배출량을 산정하였다. A7003 합금중 Mg의 첨가량을 제어하여도 압출재 생산에 소요되는 에너지의 소비량은 거의 같음을 확인하였으며 CO₂와 같은 대기오염물질을 저감시키기 위해서는 유도가열에 의한 빌렛가열공정의 적용이 가장 효과적임을 알 수 있었다. A7003 alloy has characteristics of their excellent weldability, high corrosion resistance and superior plastic working however the broadening of application for the alloy has been hampered by the lower extrudability associated by Mg content. For improvement of extrudability and enhanced recovery efficiency during Al scrap recycling, it has been generally practiced to reduce Mg content in A7003 alloy. Therefore, it is necessary to investigate the influence of Mg content on mechanical strength and extrudability of A7003 alloy. For efficient material processing which has small amounts, material life cycle assessment(MLCA) is evaluated. The quantitative analysis of energy requirements and CO₂ emission for production of A7003 extruded bar are estimated with different Mg content and billet pre-heating process (heating source by light oil or LPG). In particular, the estimation of energy requirements was performed within shipping and gating range (except the mining and extraction stages) to investigate the influence of the variables on energy requirements and CO₂ emission in detail. As Mg content increased, the flow stress and the extrusion pressure for A7003 alloy increased. It has been thought that an increment in extrusion pressure with increasing Mg content is caused by the solid solution hardening of Mg atoms in the matrix and increment in volume fraction of intermetallic compound, Mg2Si. The extrudability and the tensile strength are equal to, or above that of conventional A7003 alloy even the content of Mg varied from 1.1wt.% to 0.5wt.%.alloy. This means that minimizing the content of Mg in A7003 alloy can enhance recovery efficiency during Al scrap recycling. It can be quoted that rather than Mg content energy source for billet heating is a prime factor to determine the atmospheric CO₂ emission.
조영직,전훈재,박동규,김윤배,고동욱,정록선,송치욱,엄순호,김창덕,류호상,현진해,신봉경,김인선 대한내과학회 2002 대한내과학회지 Vol.62 No.5
Dedifferentiated liposarcoma occurs in less than 10% of all liposarcomas and is found most often in the retroperitoneum and extremities. Although cases of the primary dedifferentiated liposarcoma have been sporadically reported internationally, only one case with 8×4.5×4 ㎝ size originated from spermatic cord and one case with 10×7×5 ㎝ size in right gluteal region have been reported in Korea, but not in retroperitoneum. We report one case of the primary giant dedifferentiated liposarcoma occurred in retroperitoneum with 32×22×20 ㎝ size and 4,250 g weight. A 56-year old man was admitted due to the weight loss and diffuse abdominal pain. The abdominal computed tomography showed that a round huge mass was pressing the surrounding structures and showed delayed enhancement. Surgical excision was carried out. Histologically the tumor was composed of well differentiated liposarcomatous area and malignant fibrous histiocytoma-like dedifferentiated area. The patient refused further treatment and now he is undergoing the follow-up.
Choi, Young-Suk,Lee, Hyeon Jeong,Ku, Cheol Ryong,Cho, Yoon Hee,Seo, Mi Ran,Lee, Yoo Jeoung,Lee, Eun Jig Association for the Study of Internal Secretions 2014 Endocrinology Vol.155 No.6
<P>The importance of forkhead box class O (FoxO) proteins in reproductive endocrinology has been confirmed by age-dependent infertility in females in a FoxO3a-knockout mouse model. In this study, FoxO1 was detected in gonadotropes in the anterior pituitary. Overexpression of FoxO1 in primary pituitary cells decreased FSHβ gene expression in both basal and GnRH-stimulated conditions, and this result was replicated by the human FSHβ promoter activity. Although direct binding of FoxO1 to FoxO-binding element (FBE) (at -124 to -119 bp of the human FSHβ promoter) was not detected in an electrophoretic mobility shift assay, a DNA pull-down assay and transfection study using the mutant FBE reporter vector revealed that FBE is necessary in FSHβ suppression by FoxO1, suggestive of other cofactor requirements. GnRH stimulated the phosphoinositide 3-kinase pathway, which induced posttranslational modification of FoxO1 and retained it in the cytoplasm. We also confirmed this result in primary cell cultures; most of the FoxO1 was detected in the cytoplasm when treated with GnRH but in the nucleus when the phosphoinositide 3-kinase pathway was inhibited. These findings suggest that FoxO1 is regulated by the GnRH signaling pathway and functions as a negative regulator of FSHβ gene expression.</P>
Association Between Obesity and BRAFV600E Mutation Status in Patients with Papillary Thyroid Cancer
Lee, Jandee,Lee, Cho Rok,Ku, Cheol Ryong,Kang, Sang-Wook,Jeong, Jong Ju,Shin, Dong Yeob,Nam, Kee-Hyun,Jung, Sang Geun,Lee, Eun Jig,Chung, Woong Youn,Jo, Young Suk Springer - Society of Surgical Oncology 2015 Annals of Surgical Oncology Vol.22 No.suppl3
조국희(Kook-Hee Cho),김영배(Young-Bae Kim),서길수(Kil-Soo Seo),이형호(Hyeong-Ho Lee),이광식(Kwang-Sik Lee),송현직(Hyun-Jig Song),이상근(Sang-Keun Lee) 한국조명·전기설비학회 1998 한국조명·전기설비학회 학술대회논문집 Vol.1998 No.-
Over the years manufacturers have become increasingly aware of the importance of water purity and its effect on the quality of the final product. One of the largest problems that confronts pure water system operators is bacterial recontamination shortly after the water purification equipment. There are several recommended methods of either preventing or removing such contamination but most have inherent disadvantages. Drinking water has required new treatment techniques such as ozonation and granular activated carbon(GAC) filtration. Ozone is known to be a powerful oxidant and disinfectant. Therefore it has been found to be necessary for the treatment of taste, odor and color as an oxidant of inorganic and organic compounds.