• Journal of the Korean Society of Safety
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• v.21 no.4 s.76
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• pp.60-65
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• 2006

It is a well known fact that LCD is a central part of the IT industry which is important in the present and the future. But the biggest problem of LCD manufacturing is maintaining a cleaning room environment and administration. Therefore the purpose of this study is to first, prevent the yield depreciation and damage of products, and second, protect the worker ftom accidental electrostatic discharge during LCD manufacture. The soft x-ray ionizer is a type of electrostatic reducer device. It protects against electrostatic discharge in the cleaning room environment and is a necessary environmental factor during LCD production. The positive aspects of the soft x-ray are its shorter time and wider angle of exposure. But the negative aspect of the soft x-ray is its need for several shielding of protection from the harmful x-ray exposure. On this study, the development of the Air Nozzle-type ionizer to amend and refine some problems. For example, examined the electrostatic reduce device of a soft x-ray type and discovered the ion did not go inside well. also workers to be free from danger. An Air Nozzle-type ionizer is comprised of soft x-ray radiation and ionized air production. Air is injected through the nozzle after being ionized from radiation. It supplies air keeping the same pressure into the end foundation of ion production. The soft x-ray is the structure which radiates ionized air through the nozzle (21 holes) having micro holes of the ionizable radiation after ionizing the inside air by the ion production. A worker does not need a cover to protect against x-rays and the Air Nozzle-type ionizer is easy to set up and is more effective at eliminating electrostatic.

• Particle and aerosol research
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• v.8 no.1
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• pp.9-15
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• 2012

Three different commercial particle counters were used to measure the PM2.5 particles in this study. An Aerosol Spectrometer (AS) 1.109 model of Grimm and a Particle Sensor (PS) 3030 model of HCT were compared with an Aerodynamic Particle Sizer (APS) 3321 model of TSI. The responses of these instruments were compared for four sizes ($1.0{\mu}m$, $1.5{\mu}m$, $2.0{\mu}m$ and $2.5{\mu}m$) of polystyrene latex (PSL) particles and indoor air particles of the office room. The mode diameter, particle size distribution and total particle number concentration of PSL particles were measured by each instrument. In the office room, the total particle number concentration was measured for 25 minutes. In results of particle size distribution and mode diameter, the APS 3321 (52 size-channels) was more accurate than the AS 1.109 (31 size-channels) and PS-3030 (10-szie channels) since the APS has more number of size-channels than the other instruments. However, AS 1.109 and PS-3030 provided similar results of total particle number concentration to those from the APS 3321. In results of office room test, there were no significant difference from each instrument similar to results of PSL test.

• Journal of The Korea Institute of Healthcare Architecture
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• v.29 no.3
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• pp.17-28
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• 2023

Purpose: This study aims to provide basic data for the future construction plans of the Infectious Disease Hospitals by analyzing the area composition and required room ratios in the wards and ICU of currently under-construction infectious disease hospitals. Methods: 3 Methods have been used in this paper. 1) This study conducted a literature review on major considerations and related guidelines for hospitals specializing in infectious diseases using existing data. 2) Based on the objects and activities of the hospital space, zones and areas were set for each department according to infection control. 3) Based on the established zones and areas, basic plan drawings of three hospitals specializing in infectious diseases currently under construction were collected and architectural drawing analysis was performed. Results: 1) Infectious Diseases Hospital must have a spatial organization that can accommodate patient isolation, infection control, efficiency of medical service, and changes. 2) Zones for infection control are divided into negative pressure and non-negative pressure zones based on airborne precaution isolation. It is divided into clean and contaminated zone according to class of cleanliness by Aseptic technique. Areas are classified by objects (patients, healthcare workers, supplies) and activities (access, medical treatment, support), and a system for organizing space is established based on this. 3) By analyzing the area composition of each departmental area, each required room, and each required space in the wards and intensive care units, it provides basic data for the spatial organization for architectural planning of the infectious disease hospital. Implication: It can be used as basic data when planning related facilities by analyzing the characteristics of the space plan of the required room according to the relationship between activities, movement lines, and operation plans based on user behavior.

• Korean Chemical Engineering Research
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• v.51 no.5
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• pp.609-614
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• 2013

This study investigated the spontaneous combustion behavior of solvent-treated low rank coals. Indonesian lignite (a KBB and SM coal) and sub-bituminous (a Roto coal) were mixed with non-polar 1-methyl naphthalene (1MN) either by mechanical agitation or ultrasonication. The property change associated with 1MN treatment was then analyzed using proximate analysis, calorific value analysis, Fourier transform infrared (FT-IR), X-ray photoelectron spectroscopy and moisture re-adsorption test. Susceptibility to spontaneous combustion was evaluated using crossingpoint temperature (CPT) measurement along with gas analysis by GC. A FT-IR profile showed that oxygen functional groups and C-H bonding became weaker when treated by 1 MN. XPS results also indicated a decrease of the oxygen groups (C-O-, C=O and COO-). Increased hydrophobicity was found in the 1MN treated coals during moisture readsorption test. A CPT of the treated coals was ${\sim}20^{\circ}C$ higher than that of the corresponding raw coals and the ultrasonication was more effective way to enhance the stability against spontaneous combustion than the agitation. In the gas analysis less CO and $CO_2$ were emitted from 1MN treated coals, also indicating inhibition of pyrophoric behavior. The surface functional groups participating in the oxidation reaction seemed to be removed by the ultrasonication more effectively than by the simple mechanical agitation.

• Bulletin of the Korean Chemical Society
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• v.32 no.5
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• pp.1703-1708
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• 2011

ZSM-5-$SO_3H$ efficiently catalyzed the one-pot three-component Mannich reaction of aldehydes, anilines, and ketones. ${\beta}$-Aminocarbonyl compounds were obtained in reasonable yields and excellent stereoselectivities when the reaction was carried out at room temperature under solvent-free conditions. Simple experimental conditions and product isolation procedure makes this protocol potential for the development of clean and environment-friendly strategy for the synthesis of ${\beta}$-amino-ketones. The catalyst was recovered and reused for subsequent runs.

• Proceeding of Spring/Autumn Annual Conference of KHA
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• 2009.11a
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• pp.251-256
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• 2009

The purpose of this study was to suggest the idea for IAQ improvement of university dormitory through space analysis and residents' evaluation. The data was collected from 105 Konkuk university dormitory residents by a questionnaire survey. As a result, the idea for IAQ improvement of university dormitory can be suggested. First, it was found that it was necessary to improve size of windows and to exchange bathroom exhaust system for ventilation. Secondly, it is important for resident to ventilate and clean their room. Thirdly, the educational program for dormitory residents about maintenance of IAQ was esssentially needed. Also, it is necessary to manage air conditioning equipment maintenance and bathroom hygiene.

• Transactions of the Korean Society of Machine Tool Engineers
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• v.12 no.2
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• pp.31-36
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• 2003

Electronic or measuring instruments equipped with aspherical lens have recently been used since aspherical lens is more effective than spherical one. for the mass production of aspherical lenses, specific molds with precisely machined cores should be prepared. Some researches on the aspherical lens machining have been carried out to date. However, ultra-precise finding of aspherical or mold core has not been fully studied. In this study, the ultra-precise grinding and evaluating system were established to investigate the finding characteristics of aspherical lenses. Unlike conventional grinding process, since a highly-precise lathe were operated in a clean room without vibration the experimental results can be very useful for further studies on ultra-precise grinding process.

• Proceedings of the Korea Concrete Institute Conference
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• 1993.10a
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• pp.207-212
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• 1993

When constructing highly precise production plants, for example, super LSI plants or semiconductor plants, it is important to take the necessary control countermeasures into consideration to obtain the working microvibration environment, which is directly related to product precision. Working environment of a clean room means vibration-free and there are only ultra-miro vibration which human cannot sense. In order to provide an place having a vibration-free working environment with only ultra-micro vibration it is necessary to posses a great number of vibration isolation technlogies, wide-ranging and abundant survey and teat data, and a high level of knowledge enabling comprehensive judgments to be made. In this study, experimental modal analysis is used to analyze the dynamic characteristics of double floor for vibration-proofing near apparatus which generate vibration. It is concluded that the double floor system with rubber pad inserted between floor panel and pedestal is good for vibration proof.

• Proceedings of the KSME Conference
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• 2001.11b
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• pp.83-88
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• 2001

This paper presents modelling and analyzing method of centrifugal chiller which has a rated capacity of 200 RT(703 kW) through on-site performance test. Field data of chiller installed in the clean-room building of KIST have been collected, Simple models were developed for predicting the heat exchangers and system performances by regression of chiller operation data during 5 days in August. The models proposed here account for the effect of variations of cooling capacity, temperatures and flow rates of secondary fluids. The models are consistent with real performance data from June to September within ${\pm}5%$ error. The COP of centrifugal chiller are estimated under the standard rating conditions and reduced mass flow rate of chilled and cooling water.

• Journal of the Semiconductor & Display Technology
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• v.8 no.4
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• pp.83-88
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• 2009

In this paper TRIZ was used to solve noise and dust reduction related to cable carrier chain system. On modern machines in a clean room, the contradictions arose due to increase noise and dust for the high speed were eliminated with 40 principles and seperation rules. As the results, the sound pressure level of the new carrier chain system was reduced to below 40 dB(A), and cleanroom classifications was satisfied with ISO class 4. In these successful results, TRIZ showed its usefulness in solving the design problems even with severe constraints.