• Title/Summary/Keyword: Equipment contamination

Search Result 198, Processing Time 0.029 seconds

Development of Amenity-Oriented Air Cleaning System for Railroad Passenger Cabin (객차용 청정시스템 개발)

  • Park, Duch-Shin;Cho, Young-Min;Kwon, Soon-Bark;Park, Eun-Young
    • Proceedings of the KSR Conference
    • /
    • 2006.11b
    • /
    • pp.1234-1239
    • /
    • 2006
  • Because the indoors spaces of the passenger cabin is generally airtight to secure the safety of passengers and enhance the efficiency of the cabin air conditioning performances, the contamination pattern of them are largely similar to that of general indoor spaces. Therefore, continuous supply of outdoor air is required to keep the amenity of indoor space. Heating, ventilation, and air-conditioning (HVAC) system is composed of air cleaning filter, heater and air conditioned, blower and ducts. To achieve the clean indoor environment, an integrated control of each HVAC equipment are required. In this study, we developed the air cleaning system to enhance the amenity of the railroad passenger cabin.

  • PDF

The Measurement of Soil Conditioning Effects of Organic Materials (유기물의 토양 개량 효과 측정)

  • 주영규
    • Asian Journal of Turfgrass Science
    • /
    • v.7 no.1
    • /
    • pp.13-18
    • /
    • 1993
  • Much attention has been given recently to solve the environmental contamination in golf courses Changing to culture practice rather than chemical practice that depends on pesticides and fertilizers is a hot issue in golf courses or grasslands. Organic soil conditioners improve soil-plant envirormental conditions rich in physical properties. In this study, measuring systems to evaluate soil conditioning effects were set up for on-site purpose. After establishing the methodology for evaluating soil conditioner effects, 2 kinds of organic conditioners were rested for examination. The systems for the methodology included a set of simulating equipment for field capacity, an impact type soil column compactor, and an infiltration-percolation system. Test results using the systems showed bulk density and infiltration rate of mixed soil were decreased at highter rates of conditioner, but total porocities were increased. Increased porocities were most capillary pore space which has a positive effect on soil water potential. The systems and methodology in this study seem to have an efficiency to measure the effects of soil conditioner on site purpose.

  • PDF

Development of a Wastewater Detection System using UV Fluorescence Reaction (자외선 형광반응을 이용한 오폐수 검출장치 개발)

  • Kim, ByoungChang
    • Journal of the Korean Society of Manufacturing Process Engineers
    • /
    • v.19 no.12
    • /
    • pp.28-33
    • /
    • 2020
  • Oil-related products have provided many benefits to humanity, but are significant contributors to environmental pollution. As per the International Maritime Organization (IMO) requirements, in the future, all ships must be equipped with filtering equipment and 5ppm bilge alarms that can help remove or reduce oil products during wastewater treatment. In this study, a UV fluorescence measurement system that can detect the oil components in wastewater containing both water and oil was developed. When an excitation wavelength of 254nm was used to irradiate the wastewater, the amount of UV at a divergent wavelength of 360nm was measured to measure the contamination. Based on the measurement, it was concluded that this system is suitable for use as the 5ppm bilge alarm proposed by IMO.

Deep Learning Based TSV Hole TCD Measurement (딥러닝 기반의 TSV Hole TCD 계측 방법)

  • Jeong, Jun Hee;Gu, Chang Mo;Cho, Joong Hwee
    • Journal of the Semiconductor & Display Technology
    • /
    • v.20 no.2
    • /
    • pp.103-108
    • /
    • 2021
  • The TCD is used as one of the indicators for determining whether TSV Hole is defective. If the TCD is not normal size, it can lead to contamination of the CMP equipment or failure to connect the upper and lower chips. We propose a deep learning model for measuring the TCD. To verify the performance of the proposed model, we compared the prediction results of the proposed model for 2461 via holes with the CD-SEM measurement data and the prediction results of the existing model. Although the number of trainable parameters in the proposed model was about one two-thousandth of the existing model, the results were comparable. The experiment showed that the correlation between CD-SEM and the prediction results of the proposed model measured 98%, the mean absolute difference was 0.051um, the standard deviation of the absolute difference was 0.045um, and the maximum absolute difference was 0.299um on average.

Microbiology of Poultry Meat (가금육의 미생물)

  • Yi, Y.H.
    • Korean Journal of Poultry Science
    • /
    • v.16 no.1
    • /
    • pp.53-60
    • /
    • 1989
  • Several hundred different species of microorganisms have been reported in poultry meat. Many of them are present as a result of contamination from feathers, feet, and intestinal contents of the bird. Equipment and personnel on the processing lines contribute to spreading microorganisms. Walker and Ayres(1956) reported that eviscerated poultry carcasses had 11,000 to 93,000 organisms per sq. cm. Elliott and Michener(1961) reported that off-odors appeared from poultry carcasses when the log number of microorganisms reached 6.5 to 8.0 per st. cm. Slime formation occurred when the number of microorganisms reached a log number of 7.5 to 9.0/$\textrm{cm}^2$. However, Schmidhofer(1969) indicated that bacterial counts gave no conclusive information as to the possible shelf life of poultry meat. (omitted)

  • PDF

Long-Term Preservation Measures of Paper Records of Special Preserving Organization (특수 보존 기관의 종이 기록물 장기 보존 대책)

  • Shin, Jong-Soon;Lee, Jae-Soo
    • Journal of the Korean Graphic Arts Communication Society
    • /
    • v.30 no.1
    • /
    • pp.59-69
    • /
    • 2012
  • This study is Long term preservation measures which is closely related to preserving paper records, record condition evaluation, preservation measure and is conducted as follows. As for Means to Evaluate the Deterioration and Damaged Conditions of Records, research and analysis has been made on the contamination and deterioration examples such as damage, dry, stapler, metal, contamination, acidification which are the characteristics of paper record damage types. The of Paper record is one of the key procedures to evaluate the record material and its physi-chemical status in many criteria and to suggest the best preservation method. Between 1970 and 2000, the main record materials was fine paper and OMR paper along with partly newspaper and coarse paper, whereas the main recording material was ball point pen. Overall damage and deterioration status is, for record materials between 1940 and 1960, high deterioration was found and in urgent need for preservation measure and more damages are caused by tapes, staplers and metals. As for records after 1970, there is light deterioration but needs preservation process. There are approximately 3 million records produces before 2000, and assuming that there are 30 pages per record and that 30% has been damaged or deteriorated, 27 million pages are subject to preservation process. Among damaged or deteriorated records, there are large number of records impossible to go through deacidification process so manual preservation and restoration process is necessary as well. Securing manpower having preservation and restoration skills as well as preservation equipment(deacidification process, preservation and restoration) is in urgent need.

Microbiological Quality Evaluation for Implementation of a HACCP System in Day-Care Center Foodservice Operations I. Focus on Heating Process and After-Heating Process (보육시설급식소의 HACCP시스템 적용을 위한 미생물적 품질평가 I. 가열조리 및 가열조리후 처리 공정을 중심으로)

  • 민지혜;이연경
    • Journal of Nutrition and Health
    • /
    • v.37 no.8
    • /
    • pp.712-721
    • /
    • 2004
  • The objective of this study was to evaluate the microbiological quality of heating and after-heating processed foods for implementation of a HACCP system in day-care center foodservice operations. The evaluating points were microbial assessment and temperature of foods during receiving, cooking, and serving in heating process. In non-heating process, in addition to monitoring microbial assessment of food during preparation, cooking, and serving steps, the microbial populations of employees' hands and utensils and serving temperature were also evaluated. Microbiological quality was assessed using 3M Petrifilm$^{TM}$ to measure total plate count and coliforms for foods and utensils and Staphylococcus aureus for hands in five Gumi day-care centers. Microbiological quality assessment for foods and utensils is summarized as follows. Microbiological quality of the heating processed foods was satisfactory for cooking and serving steps. The internal temperature of food was above 74$^{\circ}C$. However, temperature control before the serving step was not achieved due to inappropriate time management between the cooking and serving steps. In the after-heating process, the total plate counts of boiled mungbean sprouts salad, blanched spinach salad, com vegetable salad were below the standard at the serving step. The majority of samples showed that coliforms exceeded the norm, which is thought to be the result of the cross-contamination from utensils. These results suggest that it is essential to educate employees on the importance of hand washing and of avoiding cross-contamination by using clean, sanitized equipment to serve food in the after-heating process. Establishing Sanitation Standard Operating Procedures (SSOPs) is an essential part of any HACCP system in day-care center foodservice operations.

Predicting the Contamination of Listeria Monocytogenes and Yersinia enterocolitica in Pork Production Using Monte Carlo Simulation (몬테카를로 시뮬레이션을 이용한 돈육 생산공정에서의 Listeria monocytogenes 및 Yersinia enterocolitica의 오염수준 예측)

  • Rho, Min-Jeong;Chung, Myung-Sub;Park, Ji-Yong
    • Korean Journal of Food Science and Technology
    • /
    • v.35 no.5
    • /
    • pp.928-936
    • /
    • 2003
  • Monte Carlo simulation was used to predict the contamination levels of Listeria monocytogenes and Yersinia enterocolitica in final pork products. Mean values of the estimated log contaminated levels of L. monocytogenes on carcasses, cut meats, and cut meats after storage were -4.59, -4.46 and -4.45 $log_{10}CFU/cm^2$ respectively. The mean values of estimated log contaminated levels of Y. enterocolitica on carcasses, cut meats, and cut meats after storage were -3.44, -4.00 and -3.97 $log_{10}CFU/cm^2$, respectively. Sensitivity analysis showed that L. monocytogenes and Y. enterocolitica in pork was most sensitive to the prevalence of L. monocytogenes and Y. enterocolitica in the equipment used.

The Development of the Contamination Prevention Module of an Optical Window Using Ultrasonic Waves (초음파를 이용한 광학창 오염방지 모듈 개발)

  • Lee, ChangHee;Jeon, KiMun;Shin, JaeSoo;Yun, JuYoung;Cho, Seonghyun;Kang, Sang-Woo
    • Journal of the Korean Vacuum Society
    • /
    • v.22 no.4
    • /
    • pp.175-180
    • /
    • 2013
  • We developed the contamination prevention module of an optical window for an In-Situ Particle Monitor (ISPM) system. the core part of the module is the generator of an ultrasonic wave and the module is to remove particles stuck to the window by the transfer of the wave force to the window surface. In order to enhance transfer efficiency of the waves the frequency of the ultrasonic wave was optimized and a low impedance material (plexiglass) and a soft sealing material (Si rubber) were used. The ISPM with the developed module was installed at the exhaust line of a BPSG CVD equipment and the effect of the module was verified.

The Development of the HACCP Plan in Korean Rice Cake Manufacturing Facilities (시판 떡류 생산에서 HACCP Plan 개발을 위한 연구)

  • Lee, Hyo-Soon;Jang, Myung-Sook
    • Korean journal of food and cookery science
    • /
    • v.24 no.5
    • /
    • pp.652-664
    • /
    • 2008
  • In this study, a Hazard Analysis Critical Control Point (HACCP) plan was developed for the sanitary mass production of commercial Korean rice cake products (Gaepidduk, Injulmi, and Julpyon). The microbiological properties of manufacturing flow were evaluated in order to develop the HACCP Plan. The moisture contents of the rice cakes ranged between 36.2${\sim}$55.3%, whereas the water activity of all samples ranged between 0.954${\sim}$1.0. Microorganisms testing was conducted during various phases of the product flow of Korean rice cake preparation, and included assessments of food equipment, work environment, and cooking employees on a small scale. During the manufacture of Injulmi, Julpyon and Gaepidduk, CCPs were purchasing & storage, steaming and cooling, molding, and holding in the A and B manufactories. At the critical limit of CCPs, storage was conducted below at $5^{\circ}C$ in soybean powder, oil, and paste with redbeans. The steaming process was conducted above at $99^{\circ}C$ for 40 min. Cooling and holding processes were conducted for 2 hours below at $15^{\circ}C$. The molding process included sanitary education for foodhandlers and training for operators. Thus, certain prerequisite programs had to be implemented prior to the implementation of the HACCP system. High levels of bacterial contamination were detected in the aprons worn to work by some employees. Additionally, periodic sanitary education for foodhandlers and training for operators or managers was required. Cross contamination by materials was expected at the place where materials were processed or stored.