Correlation Between Primary Si and Silicide Refinement Induced by Ultrasonic Treatment of Multicomponent Al–Si Alloy Containing Ti, Zr, V, and P

Jae‑Gil Jung,Young‑Hee Cho,Tae‑Young Ahn,Jae‑Hee Yoon,Sang‑Hwa Lee,Jung‑Moo Lee 대한금속·재료학회 2019 METALS AND MATERIALS International Vol.25 No.5

The correlation between primary Si and silicide refinement induced by ultrasonic treatment (UST) of multicomponent Al–Sialloy containing Ti, Zr, V, and P was investigated. UST significantly refined the primary Si phase owing to cavitation-inducedwetting and deagglomeration of MgAl2O4particles. Lowering the UST finish temperature caused deterioration of the degreeof primary Si refinement, instead leading to silicide refinement. Cavitation-induced silicide nucleation on wetted MgAl2O4consumed the MgAl2O4particles, particularly in the case of primary Si nucleation. Similarly, the formation of an AlP phaseon the silicide phase reduced the nucleation efficiency of the AlP phase. Poisoning of the MgAl2O4and AlP phases by thesilicide phase was responsible for the deterioration in primary Si refinement. Room-temperature tensile strength and hightemperatureelongation were increased by UST and were dependent on the size of primary Si.

A Comparison of Lyophilized Amniotic Membrane with Cryopreserved Amniotic Membrane for the Reconstruction of Rabbit Corneal Epithelium

Ahn Jae-Il,Jang In-Keun,Lee Doo-Hoon,Seo Young-Kwon,Yoon Hee-Hoon,Shin Youn-Ho,Kim Jae-Chan,Song Kye-Yong,Lee Hee-Gu,Yang Eun-Kyung,Kim Ki-Ho,Park Jung-Keung The Korean Society for Biotechnology and Bioengine 2005 Biotechnology and Bioprocess Engineering Vol.10 No.3

Many researchers have employed cryopreserved amniotic membrane (CAM) in the treatment of a severely damaged cornea, using corneal epithelial cells cultured on an amniotic membrane (AM). In this study, two Teflon rings were made for culturing the cells on the LAM and CAM, and were then used to support the AM, which is referred to in this paper as an Ahn's AM supporter. The primary corneal epithelial cells were obtained from the limbus, using an ex-plantation method. The corneal epithelium could be reconstructed by culturing the third­passage corneal epithelial cells on the AM. A lyophilized amniotic membrane (LAM) has a higher rate of graft take, a longer shelf life, is easier to store, and safer, due to gamma irradiation, than a (AM. The corneal epithelium reconstructed on the LAM and (AM, supported by the two­Teflon rings, was similar to normal corneal epithelium. However, the advantages of the LAM over that of the (AM make the former more useful. The reconstruction model of the corneal epithelium, using AM, is considered as a good in vitro model for transplantation of cornel epithelium into patients with a severely damaged cornea.

Reconstruction of Rabbit Corneal Epithelium on Lyophilized Amniotic Membrane Using the Tilting Dynamic Culture Method

Ahn, Jae-Il,Lee, Doo-Hoon,Ryu, Yang-Hwan,Jang, In-Keun,Yoon, Mun-Young,Shin, Youn Ho,Seo, Young-Kwon,Yoon, Hee-Hoon,Kim, Jae-Chan,Song, Kye-Yong,Yang, Eun-Kyung,Kim, Ki-Ho,Park, Jung-Keug Blackwell Publishing Inc 2007 Artificial Organs Vol.31 No.9

<P>Abstract: </P><P>Rabbit corneal epithelium was reconstructed using tilting dynamic culture with a self-manufactured, amniotic membrane (AM) supporter and a lyophilized amniotic membrane (LAM). Rabbit corneal epithelial (RCE) cells were cultured and cryopreserved after isolation from the limbus. The second- and third-passage RCE cells were plated onto the epithelial side of the LAM of Ahn's AM supporter. Two days later, the air–liquid interface culture was maintained with third-passage RCE cells for 6 days and second-passage corneal epithelial cells for 9 days. The average viability of thawed RCE cells, assessed using trypan blue dye exclusion, was 77.42%. The reconstructed corneal epithelium was characterized by histological (hematoxylin and eosin) and immunohistochemical staining (proliferating cell nuclear antigen) for light microscopy, and by reverse transcriptase-polymerase chain reaction, glucose assay, and transmission electron microscopy. The basal layer of the reconstructed corneal epithelium was well formed, and the epithelium was tightly constructed due to the increase in cell proliferation and differentiation caused by the tilting dynamic culture, as opposed to static culture. Tilting dynamic culture was useful for the reconstruction of the epithelium using easily damaged epithelial cells and resulted in more stratum cell layers. Moreover, cytokeratin (CK3) mRNA expression in tilting dynamic cultured third-passage RCE cells seeded onto AM was greater than in static cultured third-passage RCE cells. The morphology of the reconstructed corneal epithelium on LAM by tilting dynamic culture for 9 days resembled that of the skin epidermis. This was thought to be because the tilting dynamic culture not only accelerated the proliferation and differentiation of cells by physical or mechanical stimulation, but also ensured that the supply of medium was delivered to the basal cells more efficiently. Thus, the reconstruction of the corneal epithelium using LAM and tilting dynamic culture was considered to be a good in vitro model for autologous or allogeneic transplantation of corneal epithelium and skin epidermis in patients with damaged epithelia. </P>

전통누룩 진균류를 이용한 입국의 제조 및 입국곰팡이의 동정

김재호 ( Jae Ho Kim ),권영희 ( Young Hee Kwon ),이애란 ( Ae Ran Lee ),김혜련 ( Hye Ryun Kim ),안병학 ( Byung Hak Ahn ) 한국균학회 2012 韓國菌學會誌 Vol.40 No.4

다양한 향미를 가진 막걸리의 개발을 위해 전통누룩으로부터 분리한 곰팡이로 입국을 제조한 후 품질특성을 분석하여 입국의 규격에 적합하며 이취가 없고 관능이 우수한 9균주를 입국 제조용 우수균주로 최종 선발하였다. 선발된 균주는 Aspergillus oryzae(C1-5-2-2, C20-7-3, CN1.3.1-4, CN16.19.1-1, N152-1, N220-1), Mycocladus corymbiferus (N162-2), Rhizopus oryzae(N20), Lichtheimia corymbifera (N21)로 동정되었으며, 제조한 입국의 산도는 5.0~6.8, 당화력은 128~241sp이었다. Various koji were prepared by fungi isolated from traditional nuruk and their quality characteristics were investigated. Acidity and saccharification power of their koji were ranged in 5.0~6.8 and 128sp~241sp. Nine fungi which were showed good quality and sensory evaluation were identified by analysis of their nucleotide sequences with PCR-amplified 18S rDNA internal transcribed spacer-1(ITS-1) and ITS-4 genes. Among them, six strains were identified as Aspergillus oryzae and the other strains were identified as Mycocladus corymbiferus, Rhizopus oryzae, Lichtheimia corymbifera.

2003년 국내 중증급성호흡기증후군 진료 현황 및 문제점 분석

이진수,김은실,정문현,백제중,정선화,안주희,최영화,이선희,고철우,김성범,김민자,박승철,기현균,송재훈,최상호,김양수,이상오,조용균,박영훈,정숙인,김연숙,이흥범,손창희,장성희,정희진,김우주 대한감염학회 2004 감염과 화학요법 Vol.36 No.3

목적 : 2002년 말 중국에서 SARS가 발생한 이후 국내에서도 2003년 10월까지 총 3명의 추정환자, 17명의 의심환자가 보고되었다. 향후 추가적인 SARS의 유행이 우려되는 상황에서, 그간의 SARS 환자 진료에 있어서의 실질적인 준비사항, 진료 현황 등에 대한 조사를 통해 문제점을 파악하여, 향후 더 나은 대비가 될 수 있도록 개선점을 제시하고자 하였다. 재료 및 방법 : SARS로 의심되는 환자를 진료 경험이 있는 병원의료진을 대상으로 2003년 10월에 설문조사를 실시하였다. 설문에는 SARS 환자 진료 시의 실질적인 조치, 진료 현황, 병실, 응급실 및 외래에서의 격리 시설과 준비사항, 보건당국의 관리와 지원에 관한 사항을 포함하였다. 결과 : 대상이 되는 22개 병원 중 17개(17/22, 77.2%) 병원이 설문에 응하였다. SARS 환자를 위한 격리실은 응급실, 외래, 일반병실 및 중환자실에서 각각 9개(9/17, 52.9%), 5개(5/17, 29.4%), 15개(15/16, 93.7%), 4개(4/16, 25%) 병원에서 음압처리가 되어있지 않은 일인실 혹은 다인실이 사용되었고, 1개(1/16, 6.3%) 병원에서만 일반병실에서 음압격리실이 운영되었다. 입원환자의 진찰 시 개인보호구의 착용은 거의 모든 의료기관에서 이루어졌다. 보건당국에서 SARS지정병원의 시설 등을 사전에 확인한 곳은 1곳(1/12, 8.3%)이였고, 14개 병원(14/15, 93.3%)에서는 보건당국에 의뢰한 검사결과를 통하 받지 못하였다. 결론 : 의료기관에서 SARS 환자용 격리실뿐만 아니라 기존의 격리실 설비 등이 미흡하였으며, 특히 중환자실 및 외래의 준비가 더욱 부족하였다. 보건당국의 의료기관에 대한 종합적인 지원이 부족하였고, 병원과의 원활한 연계가 잘 이루어지지 않았다. SARS 만이 아닌 격리를 필요로 하는 질환의 적절한 진료를 위해 향후 병원 시설의 정비와 정부차원에서의 보다 구체적이고 실질적인 대책마련이 필요하다. Background : There was an worldwide outbreak of the Severe Acute Respiratory Syndrome (SARS) originated from China in late 2002. During that period three cases of suspected SARS and 17 cases of probable SARS were reported in Korea. With the concerns about the reemergence of SARS-coV transmission, it is important to be prepared for any possibility. So, this study is aimed to analysis the past measures in managing SARS and propose the amendatory plans to improve the preparedness. Materials & Methods : Questionnaires were collected among clinicians with any experience in managing the probable or suspected SARS cases in Oct. 2003. 17 out of 22 hospitals responded to the questionnaire. The contents in the questionnaire were practical activities, personal equipments, response plans, isolation facilities in emergency centers, outpatient clinics, general wards and intensive care units, and relationship with the public health department. Results : The dedicated isolation rooms in emergency centers, outpatient clinics, general wards, and intensive care units were prepared in 9 (9/17, 52.9%), 5 (5/17, 29.4%), 15 (15/16, 93.7%), and 4 (4/16, 25.0%) hospitals, respectively. Except for one hospital that newly made negative pressure room for SARS, single or multi-bed rooms without airborne infection control were used in all the other hospitals. The personal precaution principles were kept quite well in general wards. Before the designation of SARS hospital by the public health department prior evalution to see if the hospital was suitable for managing SARS was conducted in only 1 (1/12, 8.3%) hospital. The results of laboratory diagnosis were reported back in 1 (1/15, 6.6%) hospital. Conclusions : The isolation facilities which can control airborne infection were almost deficient not only for SARS but also for other respiratory transmissible diseases. For the infection control of transmissible diseases including SARS, more investment is needed on medical facilities and comprehensive support from the public health department required.

廢세라믹을 混合한 黃土 모르터의 美匠材料 活用方案에 관한 硏究

안재철,강병희 東亞大學校 建設技術硏究所 1999 硏究論文集 Vol.23 No.1

This paper is a study to create 'Hwangto mortar', traditional architectural materials, which is suitable to be used by being mixed with discarded ceramic powder. Therefore, workability of fluidity, contraction ratio, compressive strength after setting are compared and analyzed according to each mixing ratio. The results of this study are that the most effective mixtures in three conditions of workability, contraction ratio and compressive strength of Hwangto mortar are researched into C/H=50~60%, S/(H+C)=30~40%, and W/(H+C)=55%.

대졸 여성의 사회적 관계망과 구직 간의 관계

안재희,오재림 한국직업능력개발원 2007 직업능력개발연구 Vol.10 No.3

본 연구는 대졸여성들의 구직경로와 취업을 위해 동원한 사회적 관계망의 특성을 살펴보고 이것이 취업결과 간에 차이를 가져오는지 분석하였다. 우선, 구직경로를 보면 성별, 대학서열에 상관없이 대부분의 대졸자들이 구직정보 채널로 인터넷을 가장 많이 활용했지만 실제 구직경로는 성별, 여성집단 내 대학서열에 따라 차이를 보였다. 한편, 대졸 여성들의 사회적 관계망 특성을 보면, 대부분 대졸 이상의 학력을 지니고 자신의 경제적 지위와 비슷한 남성이 주류를 이루지만 연결강도는 여성 집단 내 대학서열에 따라 달라졌다. 그리고 비슷한 사회적 관계망을 구직과정에서 동원했어도 협력자로부터 받은 도움유형은 성별에 따라 달랐다. 이를 통해 대졸 여성의 구직과정은 젠더화 된 사회적 관계망이 개입되는 역동적 과정이라 하겠다. The purpose of this study is to analyze that the social network of female university graduates affect their job search process and job. This study intends to analyze that the female university graduates' job search activity is influenced by discriminate approach and utilization of social network along hakbol and sexism. For this study, the sample consisted of 293 persons who graduated from universities in Seoul from 2003 to 2004. The results of this study are as follows : First, there is a difference between the most used job search channel and the most successful job search channel by university hierarchy and gender. And the effect of institutional social network differs between genders, Secondly, the social network that female university graduates use to obtain job information is characterized by strong ties with university friends who are similar to respondents' economic position and educational level. Thirdly, these characters are interrelated with the information by their helpers and the job results.

무산소-호기 반응기의 유기물과 질소 제거모델 개발

안송엽,김환홍,소재철,권희태 원광대학교 2001 論文集 Vol.26 No.-

본 논문은 무산소-호기 유동상 반응기에서 폐수의 유기물과 질소제거에 관한 것을 나타내었으며, 이 공정은 두 개의 반응기 안에서 질산화와 탈질화로 얻어지는 제거율 결과를 모형화하여 검토하였다. 무산소조의 미생물 농도가 모형식으로 표현되면 -2079.898V2 - 202.2029(H/A) + 1123이고, BOD removal = -0.00613 HRT2 + 0.4014HRT + 46.993 and NO3-N removal = -0.0029 HRT2 + 0.1872 HRT + 77.45 로 각각 표현되어진다. 이러한 실험치는 모형치와 비슷한 값을 가진다고 할 수 있으며, 이 결과는 다른 방법에도 적용이 가능하다고 판단된다. This paper aims to get rid of BOD and nitrogen in wastewater as the anoxic-aerobic fluidized bed. The process for the removal of nitrogen consists of nitrification and denitrification in two reactors. The estimated formula for, Anoxic are Biomass concentration = -2079.898V2- 202.2029(H/A) + 1123, BOD removal = -0.00613 HRT2 + 0.4014HRT + 46.993 and NO3-N removal = -0.0029 HRT2 + 0.1872 HRT + 77.45. The experimental values are similar to values of estimated formula. Therefore, this result is able to adapt the other cases.

면역시킨 마우스 흉선 및 비장세포에 대한 병원성 Naegleria의 세포병변 효과

안명희,류재숙,민득영 한양대학교 의과대학 1991 한양의대 학술지 Vol.11 No.1

Naegleria fowleri is a causative agent of primary amoebic meningoencephalitis (PAM) in man and experimental animal. We investigated the interaction of immunized mouse thymocyte and splenocyte with N. fowleri trophozoites in vitro. BALb/c mouse was immunized with 150∼200×10⁴/ml N. fowleri trophozoites, intraperitoneally, once a week, for two times. Thymus and spleen cells from immunized or normal mouse cocultured with N.fowleri in 10% FCS+MEM, 37℃, 55%-CO₂incubator and cell: amoeba ratio was 200∼400:1. Thymus or spleen cells and N. fowleri were observed at 24, 48, 72 hrs after incubation by inverted microscope. Spleen cells from immunized mice showed moderate lysis aftre 72 hrs with round amoeba, but other group cells were completely lysed at 48 hrs after incubation with N. fowleri. It may be secreted a certain cytolytic amterial from N. fowleri because of cell lysis occured abruptly after 24 hrs culture. And amoebae showed better condition i.e., pseudopodaand vacuoles, after phagocytosis of lytic cell material. On the other hand, nonadherent cells from immunized spleen were completely lysed at 48 hrs with N. fowleri conculture and immunized thymus cell with aditive activated mactophage showed prolonged cell survival. And so, cooperative reaction of immunized T-lympocyte and macrophage are important to supperss N. fowleri in vitro.

알긴산 溶解物을 혼합한 厭縮 흙벽돌의 開發에 관한 實驗的 硏究

안재철,강병희 동아대학교 건설기술연구소 1999 硏究報告 Vol.23 No.2

This study is about experiment on traditional method using soil to create compressed soil brick. The soil needs water to develop fluidity in the field in different from the hydraulic cement, which cause the drying shrinkage definitely. So, the development of the soil as dry materials is more suitable than the mortar in the field. As a result, compressed soil brick using alginic acid is strong against compressure, and little deflection against drying shrinkage. So, we consider that it is possible to be used in the field as construction materials.