• 한국산업보건학회지
• /
• 제31권4호
• /
• pp.295-303
• /
• 2021

Objective: Paint manufacturing industry workers are exposed to various lung cancer carcinogenic substances including hexavalent chromium and crystalline silica. Studies have been conducted on lung cancer in Paint manufacturing industry workers and the concentration of hexavalent chromium in paint industry; however, the concentration of crystalline silica and hexavalent chromium and cases of lung cancer in a single Paint factory has never been reported in Korea. Methods: To determine whether the cancer was related to his work environment, we assessed the level of exposure to carcinogens during pouring and mixing talc and pigment. In addition, a mask fit test was performed for the worker. Results: Analysis of talc and silica bulk powder materials showed that crystalline silica (quartz) was 5% in talc and 100% in silica. The green and yellow pigments contained 87% and 92% of lead chromate, respectively. Our quantitative analysis of pigment powder samples showed that the hexavalent chromium contents quantified in the green and yellow pigment samples were 87% and 92%, respectively. In order to estimate his exposure level of hexavalent chromium, we measured a personal exposure level of hexavalent chromium for a worker in accordance with the National Institute for Occupational Safety and Health #7605 method. The results showed that the worker was exposed to the high level of hexavalent chromium (0.033 mg m-3). In addition, the talc powder also contained 5% quartz, and the worker's exposure level to respirable quartz exceeded OEL. As a result of the respiratory protection fit test for workers, the overall Fit Factor was '15' when wearing a second-grade mask and '25' when wearing a first-grade mask, significantly lower than the US Occupational Safety and Health Agency (OSHA) pass value of "100". Conclusion: Workers who pouring and mixing powder materials such as talc or colored pigments in paint manufacturing company may be exposed to high concentrations of carcinogenic substances. These findings indicate that it is necessary to local ventilation system inspection, safety and health education for employers and workers, and periodically monitoring and manage the working environment.

• 한국정밀공학회지
• /
• 제20권2호
• /
• pp.33-39
• /
• 2003

A new microlens fabrication technique, the excimer laser lithography is developed. This bases on the pulsed laser irradiation and the transfer of a chromium-on-quartz reticle on to the polymer surface with a proper projection optics system. An excimer laser lithography system with 1/4 and 1/20 demagnification ratios was constructed first, and the photoablation characteristics of the PMMA and Polyimide were experimentally examined using this system. For two different shapes of microlenses, a spherical lens and a cylindrical lens, fabrication techniques were investigated. One for the spherical lens is a combination of the mask pattern projection and fraction effect. The other for the cylindrical lens is a combination of the mask pattern projection and the relative movement of a specimen. The result shows that various shapes of micro optical components can be easily fabricated by the excimer laser lithography.

• Macromolecular Research
• /
• 제13권5호
• /
• pp.435-440
• /
• 2005

This study describes a method where the match of two different length scales, i.e., the patterns from self-assembled block copolymer (<50 nm) and electron beam writing (>50 nm), allow the nanometer scale pattern mask. The method is based on using block copolymers containing a poly(methyl methacrylate) (PMMA) block, which is subject to be decomposed under an electron beam, as a pattern resist for electron beam lithography. Electron beam on self assembled block copolymer thin film selectively etches PMMA microdomains, giving rise to a polymeric nano-pattern mask on which subsequent evaporation of chromium produces the arrays of Cr nanoparticles followed by lifting off the mask. Furthermore, electron beam lithography was performed on the micropatterned block copolymer film fabricated by micro-imprinting, leading to a hierarchical self assembled pattern where a broad range of length scales was effectively assembled, ranging from several tens of nanometers, through submicrons, to a few microns.

• 대한전자공학회논문지SD
• /
• 제47권4호
• /
• pp.20-25
• /
• 2010

평판형 rib 도파로의 설계 및 공정기술을 바탕으로 632.8 nm에서 동작하는 집적 마흐젠더 간섭계 센서(Mach-Zehnder interferometric sensor)를 제작하였다. 단일모드와 높은 감도의 두 가지 조건을 고려하여 실리카 계열($SiO_2-SiO_xN_y-SiO_2$) rib 도파로를 설계하였고 박막증착, 사진제판, RIE (Reactive Ion Etching)와 같은 반도체 공정들을 이용해 그 기하학적 구조를 구현하였다. 제작된 rib 도파로의 광출력을 cut-back방법으로 분석한 결과, 약 4.82 dB/cm의 전파손실을 측정하였다. 동시에 크롬 식각방지 층 공정을 도입하여 마흐젠더 간섭계 칩 위에 감지영역(sensing zone)을 형상화할 때 발생하는 코어 층 손상을 방지하였다. 제작된 마흐젠더 간섭계 센서를 이용한 증류수/에탄올 혼합물 굴절률 측정실험을 통해 약 $\pi$/($4.04{\times}10^{-3}$)의 소자 감도(sensitivity)를 최종 확인하였다.

• 한국재료학회지
• /
• 제8권9호
• /
• pp.871-875
• /
• 1998

사진식각 공정으로 종횡비가 매우 큰 유리 미세구조물을 제작하였다. 미세구조물의 제작에는 압축응력에 강하고 전기적 절연체인 감광성 유리를 사용하였다. 감광성 유리는 석영기판 위에 크롬이 패턴된 마스크를 사용하여 파장이 312nm인 자외선에 노광되었다. $500^{\circ}C$ 이상의 열처리공정을 거친 후 초음파 분위기에서 10%의 불산용액으로 식각함으로써 유리 미세구조물을 제작하였다. 미세구조물의 최종 형상은 감광성 유리의 두께, 마스크 패턴, 자외선 노광조건 및 식각조건에 크게 의존하였으며, 종횡비가 30이상인 스트라이프 구조의 유리 미세구조물을 제작할 수 있었다.

• 대한전기학회논문지:전기물성ㆍ응용부문C
• /
• 제53권1호
• /
• pp.47-52
• /
• 2004

3D microstructures with different side-wall angles and different scales are fabricated by both methods of inclined exposure and rear-side exposure at each of selected areas on a same substrate. Conventional methods of inclined exposure are used to make side-walls with a same inclined angle on one substrate and to get a scale error due to front-side exposure through thick photoresist layer, But, by using the proposed method, we are able to fabricate 3D microstructures on a same substrate with various side-wall angles and accurate dimensions as the original design. In the rear-side exposure, UV exposure light reflects from the chromium mask pattern after passing through the thick photoresist layer, resulting in fabrication of well-defined, inclined 3D structures inside the thick photoresist layer.

• Journal of Preventive Medicine and Public Health
• /
• 제10권1호
• /
• pp.16-24
• /
• 1977

${\ulcorner}$크롬${\lrcorner}$과 ${\ulcorner}$니켈${\lrcorner}$등의 도금(鍍金)을 하는 도금공(鍍金工)에 대하여 그 직업성질환(職業性疾患)을 관찰(觀察)하고 저 1976년(年) 6(월)月 대구시내(大邱市內) 소재(所在)하는 서로 유사한 종류와 방법으로 작업하고 있는 중소기업체(中小企業體) 중 작업환경개선(作業環境改善)이 어느 정도 되어 있는 곳과 전연 되어있지 않는 곳을 각각 1개소(個所)씩 선택(選擇)하며 비교해 본 결과 다음과 같이 요약(要約)할 수 있었다. 전반적(全般的)으로 비강내(鼻腔內) 증상(症狀)이 총출현빈도(總出現頻度) 중 50%이상을 점하며 다음 현기증(眩氣症)이 문제(文題)로 되어 있으며 환경개선(環境改善)을 함에 따라 비강내증세(鼻腔內症勢)중에서 괴양성 병변(病變)을 줄이어 증상(症狀)은 가볍게 되었으나 개입보호구사용(個入保護具使用)을 소홀히 함으로써 점차 만성적인 변화(變化)를 초래할 염려가 있었다. 각종 혈액상(血液相)중 ${\ulcorner}$헤모글로번${\lrcorner}$, ${\ulcorner}$헤마토크리트${\lrcorner}$ 적혈구(赤血球)와 요소견(尿所見)중 단백질당(蛋白質糖), ${\ulcorner}$우로비리노겐${\lrcorner}$등에는 큰 영향을 미치지 않고 있다고 생각된다.