• Title/Summary/Keyword: Space Contamination

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A Study on the Space Planing for Restaurant Kitchens to Improve Hygiene (식당 주방의 위생 향상을 위한 공간계획에 관한 연구)

  • Lee, Jong-Ran
    • Journal of The Korean Digital Architecture Interior Association
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    • v.11 no.1
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    • pp.5-13
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    • 2011
  • This research proposed the space planing methode and diagrams of restaurant kitchens to improve hygiene by analyzing the related contents collected from books and researches in interior design and HACCP (Hazard Analysis and Critical Control Point). HACCP is an effective and scientific hygiene system for food safety in order to prevent cross-contamination from food hazards. Based on the analyses, improvement of food production environments like restaurant kitchens is necessary for food hygiene. The space planing methode of restaurant kitchens to improve hygiene are followings: The circulation planing is that the direction of movement of the food, workers, waste, and dishes should be fractionated and managed for cross-contamination prevention. The space separation planing is that the spaces in the kitchen should be classified and divided into contaminated area and non-contaminated and clean area depending on the degree of cleanliness. The zoning is space arrangement with feed-back process to check the possible points of cross-contamination and correct space arrangement until the possibility of cross-contamination disappear in kitchen. However, if cross-contamination is unavoidable in some points in restaurant kitchens, hygiene facilities such as washing rooms, pass rooms, and double doors with air-shower should be located in order to remove contamination.

A Study on Hygienic Space Planing of a University Student Restaurant - Focused on the customer space in E University Student Restaurant in Seoul Applying HACCP - (대학 학생 식당의 위생적 공간 계획에 관한 연구 - 서울 E 대학 학생 식당 고객 공간에 HACCP 적용 중심으로 -)

  • Lee, Jong-Ran
    • Korean Institute of Interior Design Journal
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    • v.20 no.3
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    • pp.182-189
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    • 2011
  • This research suggests a way of hygienic space planing of the customer space in the university student restaurant of E University in Seoul. For this study. the behavior observation in the restaurant was conducted in order to analyze the sequence of customer behavior related space planing applying HACCP (Hazard Analysis And Critical Control Point). Also the survey was conducted to analyze opinions of customers about hygiene of the space. The results of the analyses of the observation and the survey were similar in terms of hygiene. In conclusion, for hygienic space planing of the customer space in restaurant, the space circulation should be planned according to the hygienic sequence of customer behavior. The spaces in restaurant should be divided into two areas: the clean area and the contaminated area to prevent cross-contamination. The clean area, such as spaces preparing dishes and food including water and table hall where customers eat, should be separated from the contaminated area such as the spaces where waste is handled and where dirty dishes are kept. In order to prevent cross-contamination, hygiene facility to remove contamination should be located before going to the clean area. More specifically, the hygiene facility should be located between a cash counter and a space preparing dishes so that customers can wash their hands before they touch dishes. Space arrangement with feed-back process to check the possible points of cross-contamination and correct space arrangement until the possibility of cross-contamination is removed in the restaurant.

Contamination Control of Optical Observation Satellite

  • Lee, Chang-Ho;Lee, Choon-Woo;Cho, Young-Jun;Whang, Do-Soon
    • Bulletin of the Korean Space Science Society
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    • 2008.10a
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    • pp.28.3-28.3
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    • 2008
  • Contamination has the potential for degrading the performance of the optical payload beyond the limits defined by mission requirements, therefore it must be considered a risk to system performance and must be mitigated. To mitigate contamination problem, contamination budget is allocated according to the contamination requirements which is derived from contamination effect analysis. Once the contamination budget is allocated, prediction for on-ground and in-orbit contaminants amounts and cleanliness control is performed. In this article, typical contamination control for observation satellite is described.

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Effect of Particle Contamination on Objective Lens in a CD-ROM Drive on Laser Diode Power and Photo Diode RF Signal (CD-ROM 드라이브의 대물렌즈 입자오염이 Laser Diode의 Power와 Photo Diode의 RF Signal에 미치는 영향)

  • Pae, Yang-Il;Hwang, Jung-Ho
    • Proceedings of the KSME Conference
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    • 2003.04a
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    • pp.1429-1434
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    • 2003
  • A number of dust particles are intruded into ODD(Optical disk drive) due to the flow caused by disk rotation and are adhered to a lens or disk surface. The space between the disk and the lens is being reduced. Someone indicates the problems of this drive that are relatively small data storing capacity and slow access time. In recent, the problems of this optical disk drive mentioned above are being solved by adding the speed of the disk's revolution, making the actuator high-speed or light, and making the beam spot size smaller than making the space narrow between disk and lens. These particle contamination affects seriously RF Signal, readout signal in an ODD. Especially, the affected parts by a particle contamination in an ODD's readout signal are objective lens and media.

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Contamination measurement, Analysis & Control for Satellite (인공위성의 오염 측정, 분석 및 관리)

  • Lee, Sang-Hoon;Hong, Seok-Jong;Cho, Hyok-Jin;Seo, Hee-Jun;Moon, Guee-Won
    • Aerospace Engineering and Technology
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    • v.9 no.2
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    • pp.116-122
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    • 2010
  • It is necessary to be careful about contamination control to minimize the accumulation of the contamination material on satellite surface during the I&T phase. In the space environment which characterized by high vacuum, high and very low temperature, contamination material causes satellite to lose its own performance. Especially, contamination material can accumulate on critical surfaces such as lenses, mirrors, and sensors. KARI(Korea Aerospace Research Institute) conducts the clean room to control and minimize the contamination effect. This paper introduces the principle of contamination and the method of measure and analysis for the contamination.

DC Langmuir Probe for Measurement of Space Plasma: A Brief Review

  • Oyama, Koichiro
    • Journal of Astronomy and Space Sciences
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    • v.32 no.3
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    • pp.167-180
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    • 2015
  • Herein, we discuss the in situ measurement of the electron temperature in the ionosphere/plasmasphere by means of DC Langmuir probes. Major instruments which have been reported are a conventional DC Langmuir probe, whose probe voltage is swept; a pulsed probe, which uses pulsed bias voltage; a rectification probe, which uses sinusoidal signal; and a resonance cone probe, which uses radio wave propagation. The content reviews past observations made with the instruments above. We also discuss technical factors that should be taken into account for reliable measurement, such as problems related to the contamination of electrodes and the satellite surface. Finally, we discuss research topics to be studied in the near future.

An efficient method using the modified view factor for estimating the molecular backscattering probability in the space conditions (Modified View Factor를 이용한 인공위성 분자오염 역류확률 예측법)

  • Lee, Jin-Won;Lee, Jae-Dal;Yi, Min-Young;Han, Dong-In;Lee, Chang-Ho;Lee, S.-R.
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.33 no.4
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    • pp.57-62
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    • 2005
  • Satellite contamination from back-scattered molecules has long been analyzed using the BGK theory or the DSMC technique which are rather inefficient in that they are complicated or take a long time in the analysis. This study presents a new technique of estimating the back-scattering contamination, which is very simple and easy to use like the view factor method and also very accurate. This method, called the modified view factor method, is equivalent to the DSMC in so far as the molecular thermal velocity is much smaller than the satellite velocity and the mean free path much longer than the satellite.

Microbiological Contamination in Office Buildings by Work Space Structure (사무공간 구조에 따른 실내공기 중 생물학적 오염분포 특성)

  • Won, Dong-Hwan;Huh, Eun-Hae;Jeong, Ho-Chul;Moon, Kyong-Whan
    • Journal of Environmental Health Sciences
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    • v.38 no.3
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    • pp.213-222
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    • 2012
  • Objectives: This study was undertaken in order to evaluate by work space zoning and structure the concentrations of biological contaminants in the indoor air of domestic office buildings. Methods: Air samples were collected in the office spaces of 15 office buildings in Seoul from June 28 to July 28, 2011. Prior to the sampling, each office was classified into 'open-plan office', 'cellular office' and 'mixed office' according to the work space zoning. To evaluate the biological contamination of indoor air, total suspended bacteria (TSB), Gram positive bacteria (GPB), Staphylococcus aureus (S.A), Methicillin-resistant Staphylococcus aureus (MRSA), Gram negative bacteria (GNB) and fungi were investigated. During the sampling, temperature, relative humidity and carbon dioxide ($CO_2$) were measured. Results: The TSB concentrations ($GM{\pm}GSD$) were $452({\pm}1.3)cfu/m^3$ in open-plan offices, $366({\pm}1.3)cfu/m^3$ in cellular offices and $287({\pm}1.5)cfu/m^3$ in mixed offices, and there were significant differences between the three groups (p<0.05). The highest concentrations ($GM{\pm}GSD$) of fungi were found in the indoor air of cellular offices $128({\pm}1.0)cfu/m^3$, which was at least three times higher than the concentrations in mixed offices $43({\pm}1.0)cfu/m^3$ (p<0.05). Conclusions: Microbiological contamination in the indoor air of office buildings by work space structure was the highest with the open-plan office layout which includes no high walls or doors separating the occupants.

A Study on Hygienic Spatial Composition of Self-Service Restaurants by Applying HACCP (HACCP를 적용한 셀프서비스 식당의 위생적 공간구성에 관한 연구)

  • Lee, Jong-Ran
    • Korean Institute of Interior Design Journal
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    • v.20 no.5
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    • pp.178-187
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    • 2011
  • This research suggested the hygienic spatial composition of sell-service restaurants applying HACCP(Hazard Analysis and Critical Control Point System). The circulation of the food, dishes, waste, workers and customers were each fractionated and arranged according to the hygienic sequence of cooking food in kitchen and process for eating food within the customer space. The spaces were separated by the degree of cleanness(clean area, semi-clean area, contaminated area). After that, hygiene facilities to remove contamination and pass facilities intended to control moving were added at the possible points of cross-contamination in oder to prevent the cross-contamination. For hygienic spatial composition of self-service restaurant, the following should be acknowledged: In the kitchen, spaces in which the food is handled after being heated should be located in the clean area. As of the customer space, spaces where dishes are prepared, food and water is received, and the table hall should be located in the clean area. Food circulation should flow from the contaminated area to the clean area. Food, dishes, waste should be moved through pass facilities so that workers do not have to come and go between other areas of cleanness. Also lockers for private clothes and lockers for uniforms should be separated. Hygiene facilities should be easily accessible so that workers can use them whenever they enter their working area. The contaminated area where dirty dishes are dealed with should be separated from the clean area. Waste should be thrown out without crossing cooking areas. As of customer circulation, the hygiene facility for hand washing should be located near the space where dishes for self-service are placed. The customer circulation should lead customers to leave restaurants after giving back the dirty dishes in the contaminated area.

CHARACTERISTICS OF THE CONTAMINATED LANGMUIR PROBE (오염된 LANGMUIR 탐침의 특성)

  • Pyo, Y. S.;Min, K. W.;Choi, Y. W.;Lee, D. H.;Kang, K. M.;Hwang, S. M.;Kim, B. C.;Kim, J.;Lee, S. J.
    • Journal of Astronomy and Space Sciences
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    • v.12 no.2
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    • pp.234-243
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    • 1995
  • Korea's third rocket, which is currently under development for launch in 1997, is expected to reach as high as 160km and thus, it will provide a good opportunity for the direct measurement of the plasmas in the E-region ionosphere of the Korean peninsula. Langmuir probe techniques, which are the basic tools of the plasma experiment, may yield inaccurate results if they are applied in the conventional form as they are used in the laboratory experiments because of the contamination. In the present paper we study the contamination problem by performing the ground experiments in the vacuum chamber using the contaminated probe. The result show that the contamination effect is reduced when the plasma density is low or when the frequency of the sweep voltage is fast. We propose a modified Langmuir probe based upon our experiments which is suitable for the rocket experiments.

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