• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2007년도 춘계학술대회 논문집
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• pp.751-752
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• 2007

• Tribology and Lubricants
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• 제32권2호
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• pp.56-60
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• 2016

Sapphire has a high hardness and strength and chemical stability as a superior material. It is used mainly as a material for a semiconductor as well as LED. Recently, the cover glass industry used by a sapphire is getting a lot of attention. The sapphire substrate is manufactured through ingot sawing, lapping, diamond mechanical polishing (DMP) and chemical mechanical polishing (CMP) process. DMP is an important process to ensure the surface quality of several nm for CMP process as well as to determine the final form accuracy of the substrate. In DMP process, the material removal is achieved by using the mechanical energy of the relative motion to each other in the state that the diamond slurry is disposed between the sapphire substrate and the polishing platen. The polishing platen is one of the most important factors that determine the material removal characteristics in DMP. Especially, it is known that the geometric characteristics of the polishing platen affects the material removal amount and its distribution. This paper investigated the material removal characteristics and the effects of the polishing platen groove in sapphire DMP. The experiments were preliminarily carried out to evaluate the sapphire material removal characteristics according to process parameters such as pressure, relative velocity and so on. In the experiment, the monitoring apparatus was applied to analyze process phenomena in accordance with the processing conditions. From the experimental results, the correlation was analyzed among process parameters, polishing phenomena and the material removal characteristics. The material removal equation based on phenomenological factors could be derived. And the experiment was followed to investigate the effects of platen groove on material removal characteristics.

• KSBB Journal
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• 제15권5호
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• pp.537-540
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• 2000

일반적으로 paclitaxel과 유사한 구조를 가진 복잡한 유도체의 분리나 최종 제품에서의 엄격한 규정 등으로 인하여 한 단계의 HPLC system으로 정 제하는 것은 상당히 어렵다. 이러한 이유로 두 단계 HPLC system으로 식물세포 배양액으로 부터 paclitaxel의 대량 정제를 수행하였다. 즉, 첫번째 단계에 서 reverse-phase HPLC column, 두번째 단계에서 normal­p phase HPLC column을 사용하여 최종 제품을 얻었다. 또한 최종 정 제 된 paclitaxel 내 에 포함되어 있는 불순물 profile 확 언, 함량 분석, 그리고 이들 물질들에 대한 분리, 정제 및 동 정을 실시하였다 이들 불순물들 중에서 0.1% 이상되는 것은 모두 6종 (side chain derivative, baccatin III, 10-deacetyltaxol, cephalomannine, taxane derivative, 7-epitaxol)이며 NMR과 MS를 사용하여 화학구조를 분석한 결과 이미 알려진 pacli­t taxel 유도체 또는 전구체와 동일한 물칠로 밝혀 졌다. 본 연구 결과는 결국 paclitaxel 생산을 위한 품질관리 (quality con­t tr이)와 허가를 위한 자료로 유용하게 사용되어 진다.