• Safety and Health at Work
• /
• v.10 no.1
• /
• pp.114-121
• /
• 2019

Background: The photolithography process in the semiconductor industry uses various chemicals with little information on their constitution. This study aimed to identify the chemical constituents of photoresist (PR) products and their by-products and to compare these constituents with material safety data sheets (MSDSs) and analytical results. Methods: A total of 51 PRs with 48 MSDSs were collected. Analysis consisted of two parts: First, the constituents of the chemical products were identified and analyzed using MSDS data; second, for verification of the by-products of PR, volatile organic compounds were analyzed. The chemical constituents were categorized according to hazards. Results: Forty-five of 48 products contained trade secrets in amounts ranging from 1 to 65%. A total of 238 ingredients with multiple counting (35 ingredients without multiple counting) were identified in the MSDS data, and 48.7% of ingredients were labeled as trade secrets under the Korea Occupational Safety and Health Act. The concordance rate between the MSDS data and the analytical result was 41.7%. The by-product analysis identified 129 chemicals classified according to Chemical Abstracts Service No., with 17 chemicals that are carcinogenic, mutagenic, and reprotoxic substances. Formaldehyde was found to be released from 12 of 21 products that use novolak resin. Conclusion: We confirmed that several PRs contain carcinogens, and some were not specified in the toxicological information in the MSDS. Hazardous chemicals, including benzene and formaldehyde, are released from PRs products as by-products. Therefore, it is necessary to establish a systematic management system for chemical compounds and the working environment.

• Korean Journal of Metals and Materials
• /
• v.46 no.2
• /
• pp.69-79
• /
• 2008

A composition consisting of 10 nm-Ni/1 nm-Pd/(30 nm or 70 nm-poly)Si was thermally annealed using rapid thermal for 40 seconds at $300{\sim}1100^{\circ}C$ to improve the thermal stability of conventional nickel monosilicide. The annealed bilayer structure developed into $Ni(Pd)Si_x$, and the resulting changes in sheet resistance, microstructure, phase, chemical composition, and surface roughness were investigated. The silicide, which formed on single crystal silicon, could defer the transformation of $NiSi_2$, and was stable at temperatures up to $1100^{\circ}C$. It remained unchanged on polysilicon substrate compared with the sheet resistance of conventional nickel silicide. The silicides annealed at $700^{\circ}C$, formed on single crystal silicon and 30 nm polysilicon substrates exhibited 30 nm-thick uniform silicide layers. However, silicide annealed at $1,000^{\circ}C$ showed preferred and agglomerated phase. The high resistance was due to the agglomerated and mixed microstructures. Through X-ray diffraction analysis, the silicide formed on single crystal silicon and 30 nm polysilicon substrate, showed NiSi phase on the entire temperature range and mixed phases of NiSi and $NiSi_2$ on 70 nm polysilicon substrate. Through scanning probe microscope (SPM) analysis, we confirmed that the surface roughness increased abruptly until 36 nm on 30 nm polysilicon substrate while not changed on single crystal and 70 nm polysilicon substrates. The Pd-inserted nickel monosilicide could maintain low resistance in a wide temperature range and is considered suitable for nano-thick silicide processing.

• Composites Research
• /
• v.35 no.6
• /
• pp.469-476
• /
• 2022

In this paper, the microwave absorbing characteristics after the impact of the radar-absorbing structure (RAS) consisting of periodic pattern sheet (PPS) and glass fiber-reinforced plastic (GFRP) were experimentally investigated. The fabricated RAS effectively absorbed the microwave in the X-band (8.2-12.4 GHz). In order to induce the damage to the RAS, a low-velocity impact test with various impact energy of 15, 40, and 60 J was conducted. Afterward, the impact damage was observed by using visual inspection, non-destructive test, and image processing method. Moreover, the absorbing performance of intact and damaged RAS was measured by the free-space measurement system. The experiment results revealed that the delamination damage from the impact energy of 15 J did not considerably affect the microwave absorbing performance of the RAS. However, fiber breakage and penetration damage with a relatively large damaged area were occuured when the impact energy was increased up to 40 J and 60 J, and these failures significantly degraded the microwave absorbing characteristics of the RAS.

• Journal of the Korea institute for structural maintenance and inspection
• /
• v.10 no.5
• /
• pp.129-138
• /
• 2006

Composite deck plate using a pre-assembled re-bar truss for slab with corrugated zinc galvanized sheet iron at manufactory, is given the improvement on design, manufacture, and performance for construction work of cast-in-place reinforced concrete slab by enabling to cast concrete directly without the form work. There are two methods in analyzing composite deck : Simplified 2D analysis and 3D analysis. Although simplified 2D analysis is being used up to date, the use of 3D analysis, allowing for the vierendeel behavior of composite deck by real configuration correlating to bar reducing, is demanded. To compare the simplified 2D analysis applied to allowable stress design with 3D analysis applied to limit state design, 8 specimen are manufactured. Main variables include the depth of slab, the length of span, the diameter of bottom bar and lattice bar, and the presence of corrugated zinc galvanized sheet iron. The comparison from the experimental result and analytical result indicates that applying of simplified 2D analysis is possible for the use of D10 with bottom bar. However, it is more reasonable to apply 3D analysis which allows to indicate vierendeel behavior considered the real configuration.

• Journal of the Korea institute for structural maintenance and inspection
• /
• v.12 no.1
• /
• pp.193-202
• /
• 2008

This paper investigates experimentally the confining effect, strengthening capacity and rebound rate of sprayed Fiber-Reinforced-Polymer (SFRP). From the method, resin and chopped fibers are sprayed separately from the nozzle with high pressure, and then they are attached to the concrete surface, so structure could be repaired. To evaluate the strengthening effect of sprayed FRP, cylindrical specimens and beam specimens were strengthening with SFRP. As main material of FRP, glass fiber and polyester resin are used. To investigate the optimum condition of sprayed FRP, the effects of fiber length, coating thickness, fiber volume ratio and concrete strength were examined. Capacities of sprayed FRP method were also compared to the FRP sheet method. In case of the sprayed FRP, rebound rate is important parameter considering economical efficiency and constructibility, so rebound rate of was discussed. From the test results, optimum conditions of sprayed FRP were determined. SFRP method showed superior strengthening capacities than FRP sheet method.

• Clean Technology
• /
• v.3 no.2
• /
• pp.13-24
• /
• 1997

The present paper aims to give basic information to establish zero emission material cycle including the minimization of emissions from industrial production processes and the area in regional scale. Strategies and methodologies to analyze emissions from the production processes and our human activities and to reduce those emissions by refining and/or replacing the unit process with the alternatives are introduced as well. Quantitative evaluation and management systems of any raw materials and the production process are from vie points of treatment are essential. Estabiishment of a process networking for the recycle of discharged non-products materials by the intra-process, trans-process and the trans-industries are proposed. Procedures and priorities to formulate industrial and regional zero emission system are proposed as well.

• Proceedings of the Korean Society for Technology of Plasticity Conference
• /
• 2003.10a
• /
• pp.144-147
• /
• 2003

In order to evaluate spring-back behavior in automotive sheet forming processes, a panel shape idealized as a SS-rail has been investigated. After spring-back kas been predicted fer SS-rails using the finite element analysis, results has been compared with experimental measurements for three automotive sheets. To account for hardening behavior such as the Bauschinger and transient effects in addition to anisotropic behavior, the combined isotropic-kinematic hardening law based on the Chaboche type single-surface model and a recently developed non-quadratic anisotropic yield function have been utilized, respectively.

• Proceedings of the Korean Society For Composite Materials Conference
• /
• 2002.05a
• /
• pp.44-47
• /
• 2002

A liner static and dynamic analysis for a golf shaft, which is made of carbon fiber reinforced composite materials, is presented in this study. Major mechanical parameters of golf shafts such as deflection, torsional angel, frequency of vibration(CPM), and kick point are analyzed by finite element method. The effects of major parameters on the performance of golf shafts are also discussed. The results show that the major parameters of golf shafts are strongly dependent on the material properties of fibers and design pattern of golf shafts. The present results will be useful to design sheet-rolled golf shafts.

• Journal of Korean Society of Industrial and Systems Engineering
• /
• v.25 no.5
• /
• pp.60-66
• /
• 2002

The military services have sought to improve the overall quality, management, and delivery of military technical information in all of its aspects. The efforts concentrated on developing IETM(Interactive Electronic Technical Manual) by using the application of computer technology for the storage, control, and presentation of maintenance, system-operation, training, and other forms of logistic-support technical information. In this paper, the methodologies are presented to evaluate the operational effectiveness of IETM which consists of confirmity and performance. Confirmity is evaluated by the check-sheet based on the standard of CALS, and performance by the comparison of the technician performance between IETM and paper-TM.

• Proceedings of the Korean Society for Emotion and Sensibility Conference
• /
• 2001.05a
• /
• pp.210-214
• /
• 2001

본 연구의 목표는 인간의 감성을 평가하기 위하여 행해지는 실험에 있어서 생리신호 측정값 및 주관평가 측정값을 자동적으로 분석하여 결과를 산출하는 시스템을 설계하는데 있다. 인간의 감성을 평가하기 위한 방법으로서 인간의 생리신호(ECG,EEG,GSR,SKT등)를 측정하여 얻는 객관적데이타와 형용사에 의해 측정되는 주관적데이타가 있다. 통합감성평가시스템은 이러한 주관적데이타 객관적데이타를 분석하여 최종적이니 감성평가결과를 산출하는 시스템이다. 지금까지 감성평가실험에서 생리신호 측정값의 분석과 주관적평가측정값의 분석은 상당한 시간과 인력이 소비되었다. 이런 모든과정을 처리할 수 있는 시스템을 개발함으로써 보다 효과적인 실험환경의 조성 및 실험결과 산출로부터 신뢰성있고 다양한 결과를 도출해 낼 수 있을 것이다. 본 시스템은 감성종합 데이터베이스, 생리신호분석시스템, Sheet에 의한 주관평가 시스템, 실시간 주관평가 시스템을 통합하는 시스템이다.