• 한국자동차공학회논문집
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• 제8권5호
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• pp.207-215
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• 2000

This study theoretically investigated the roll-off cleanliness operation to eliminate the built-in contaminants which are primarily the result of manufacturing and assembly procedures first. A rigorous analytical examination of the cleaning process associated with hydraulic systems was performed by developing the general filtration process equations. The sloughing process by which built-in contaminant is entrained in the system fluid was examined during the development of a general analytical expression for sloughing rate. This sloughing rate expression in conjunction with the filtration process equations have lead to a relationship rate expression in conjunction with the filtration process equations have lead to a relationship which describes the flushing and clean-up operation for the hydraulic systems. The effects of the primary roll-off cleanliness factors was discussed and illustrated on the figures. Then, the analytical results was shown to be usefully applied into the design of roll-off flushing equipment for the hydraulic system of a tractor.

• 한국수소및신에너지학회논문집
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• 제30권5호
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• pp.428-435
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• 2019

A comparative evaluation of engine cleanliness was performed on the transport gasoline blended with bio- alcohols, and this study was considered to achieve the aim of greenhouse gas reduction in Korea. In particular, the fuel blended with bio-ethanol and bio-butanol showed the best engine cleaning performance both on combustion chamber deposits and intake valve deposits. The deposit control gasoline additive was effective to remove intake valve deposits. In contrast, the amount of combustion chamber deposits were tend to increase even though fuels blended with bio-alcohols were used. In overall, fuels blended with bio-alcohols, compared to fossil fuels, still showed outstanding performance in terms of engine cleanliness.

• 대한기계학회논문집B
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• 제31권5호
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• pp.457-466
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• 2007

A numerical and experimental study on the evaluation and the prediction of cleanliness level in the mini-environment system was carried out. Using the concept of local mean air-age (LMA) and effective flow rate, the new direct method for estimating the mini-environment was developed and compared with the previous performance index of airflow pattern characteristics. It was found out that the airflow pattern analysis is a restricted method to estimate the real performance of the mini-environment. The reason is that the airflow pattern cannot predict the effect of the increment of the ventilation rate on the cleanliness level in the mini-environment. While LMA is capable of showing the effects of the contaminant accumulation caused by turbulent intensity, eddy, and the increment of the effective flow rate. This result showed that LMA is more exact and effective performance index than the previous one like the airflow pattern characteristics.

• 한국식품조리과학회지
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• 제28권2호
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• pp.89-96
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• 2012

The purpose of this study was to evaluate the importance and satisfaction with Korean food for foreigners living in Busan with consideration for nationalities, for the sake of improving satisfaction with Korean food. The research was performed using questionnaires and conducted from August 14 to September 30, 2011 for 376 foreigners in Busan. Total mean scores for the importance (4.01/5.00) and satisfaction (3.59/5.00) of Korean food attributes were significantly different (p<0.01). The gaps of the importance score and satisfaction score were -0.91 for cleanliness of food, -0.74 for taste, -0.70 for quality, and -0.68 for smell. Mean scores of satisfaction for Americans and Europeans (3.69) and Southeast Asians (3.78) were significantly (p<0.01) higher than those of Japanese (3.44) and Chinese (3.43) descent. Notably high importance and low satisfaction attributes of Korean food broken down by nationality were cleanliness for Americans/Europeans; quality and cleanliness for Japanese; texture and price for Chinese; and taste, smell, and price for Southeast Asians. Attributes rated with high importance and satisfaction were health benefits, nutrition, and quality for Americans/Europeans, Chinese, and Southeast Asians; taste and price for Americans/Europeans and Japanese; and cleanliness for Chinese and Southeast Asians.

• Animal Bioscience
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• 제36권11호
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• pp.1769-1774
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• 2023

Objective: Resting comfort may influence sleep-related lying postures in cattle. This study aimed to investigate the effects of bed cleanliness on tucked (TSP) and extended (ESP) head positions in sleep-related lying postures. Methods: The study was conducted over two experimental periods. In each period, four Japanese Black fattening cattle were assigned to the cleaning treatment (CL), in which bedding material was replaced once during each experimental period. Four cattle were assigned to the control treatment (CON) with no bed cleaning. Daily duration, bout frequency, and bout length of sleep-related lying postures were measured, and bed moisture, ammonia concentration in the air, plasma cortisol, and serotonin concentration were also measured within one week before and after cleaning treatment in each period. Results: The bed moisture and ammonia concentrations decreased in CL after bed cleaning. Following bed cleaning, the duration and bout frequency of TSP in CL decreased compared to that observed in CON, whereas ESP in CL increased after bed cleaning. Total duration of sleep-related lying postures and cortisol and serotonin levels did not differ between CL and CON. Conclusion: These results suggest that cattle in sleep-related lying postures shifted from tucked head positions to extended head positions in response to improved bed cleanliness.

• Korean Chemical Engineering Research
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• 제47권6호
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• pp.688-694
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• 2009

PCB의 먼지 제거용 세정제로 사용되는 스프레이형 세정제를 선정하여 이에 대한 청정도를 평가하였다. 친환경적인 대체 세정제를 채택하기 위해서는 세정제의 세정성, 환경성, 경제성을 평가하여 체계적인 선정절차에 의거하여 도입 및 적용하여야 한다. 객관적이고 효율적인 세정성 평가방법의 정립이 현시점에서 매우 중요하다. 본 연구에서는 여러 세정성 평가 방법들 중 표면관찰평가법인 SEM-EDX(Scanning Electron Microscopy/Energy-Dispersive X-ray) 분석과 적외선열화상카메라(THERMOVISION A20 model)를 이용하여 청정도를 평가하였다. CT-2770 모델의 사운드카드를 $2{\times}2cm$로 잘라내어 스프레이 세정 전과 후의 청정도를 SEM의 이미지 분석을 통해 관찰할 수 있었고 EDX의 성분분석을 통해 먼지의 제거율을 정량화할 수 있었다. 컴퓨터의 P4T-E 모델의 마더보드와 IPC-A-36 모델의 기판을 사용, 오염물로 먼지와 철가루를 사용하여 열화상카메라로 세정 전, 후의 상온과 $50^{\circ}C$ Oven에 방치된 시간의 차이에 따른 온도의 변화를 비교하였다.

• Nutritional Sciences
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• 제8권2호
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• pp.140-147
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• 2005

In order to promote foodservice for older adults, foodservice directors in Continuing Care Retirement Communities (CCRCs) must identify the dimensions used by residents to evaluate the service quality of dining service. A multidimensional measure of perceived service quality was developed based on residents' responses about their experiences with dining service. A survey was administered to residents in two CCRCs. Based on the results of principal component analysis, this study identified four dimensions: food quality, dining room employee's attitude and service skills, dining room employee's safety and cleanliness, and systemization of service delivery process. A new dimension that reflects residents' concern for the dining mom employees' safety and cleanliness also emerged. 1bis study points to areas of improvement for food quality and dining room employee's safety and cleanliness.

• 드라이브 ㆍ 컨트롤
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• 제9권2호
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• pp.22-27
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• 2012

In order to improve the life and reliability of fluid components used in the Automotive, Hydraulics and Aerospace industries, the cleanliness of the system parts and components before their assembly into the system is being addressed. The measurement of components and parts cleanliness is related to contaminant collection, analysis and data reporting and ISO Standards are continually being developed to control procedures. This Paper explains the processes in these standards and explains how similar procedures have been adapted to suit the requirements of the above Industries. It also gives guidance and recommendations on the implementation of these standards, so that the best use can be made of them.

• 상하수도학회지
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• 제25권4호
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• pp.519-525
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• 2011

We studied on the effect of faucet cleanliness, faucet conditions (screen, mixing faucet), and flushing time for bacterial detection in tap water. As results, tap water should be left to run to waste for 2 to 3 minutes and if a questionable cleanliness is questionable, disinfect the faucet by using flaming or other methods before sampling. We proposed sampling method to decrease effect of factors associated with bacterial detection in tap water and contributed to be evaluated more accurate water quality.

• 한국식생활문화학회지
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• 제9권2호
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• pp.149-157
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• 1994

Hospitalized patients' perceptions of the quality of hospital foodservice and their importance were surveyed through questionnaires by 820(men 435, women 385) hospitalized patients in Seoul. The results are as follows: Most respondents agreed with the following foodservice characteristics that meals arrived exactly the same time every day(74.6%), cleanliness of dishes(64.9%), employees leave food within reach(60.2%), and employees who bring meals are cheerful(58.7%). Only 34.2% of respondents agreed to variety of menu; 12.9% of respondents viewed these foodservice characteristics as important in selecting a hospital; cleanliness of dishes(66.4%), variety of menu(55.0%), and varying food item combination(45.9%) were considered important by respondents; appetite, mood, and atmosphere of ward were positively correlated(p<0.001) with rating of the foodservice characteristics, but length of hospitalization was negatively correlated(p<0.001) with them; familiarity with cooking method, varying food item combination, cleanliness of the dishes, and foodservice employees' pleasant greeting were positively correlated(p<0.001) with rating of the taste, nutrition, and fresshness of the food characteristics.