• Title/Summary/Keyword: Cleaning time

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VOC Emission Characteristics of Dry Cleaned Wool Scarfs through Small Chamber Test (소형챔버를 이용한 드라이클리닝 모직물 목도리의 휘발성유기화합물 방출 특성)

  • Shin, Jin-ho;Kwon, Seung-mi;Kim, Hyun-soo;Roh, Bang-Sik;Kim, Kwang-rae;Eo, Soo-mi;Jung, Kweon;Lee, Young-Kyu
    • Journal of Environmental Health Sciences
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    • v.43 no.2
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    • pp.95-102
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    • 2017
  • Objectives: This study was conducted to evaluate the emission of VOCs from clothing that had been dry cleaned. Methods: In order to ensure the same conditions, f100% wool scarves were selected as the fabric type. Four identical tests were conducted on the option of either removing the plastic bags which came from the dry cleaning shop or not. The scarf was located inside a closet or room for one or two days. Small chamber tests were conducted to determine the VOC emission characteristics under the same conditions such as temperature, humidity, loading factor, and air exchange rates. Air from the chamber for VOCs was sampled by Tenax TA tube and analyzed by thermal desorption and GC/MSD. Results: Assuming that test represented dry cleaning and consumer's conditions well enough, we can conclude that immediate emissions after the dry cleaning of the scarfs caused elevated levels of TVOC, five VOCs (benzene, toluene, ethylbenzene, xylene, stylene), and decane group compounds. Conclusions: By removing the plastic bags which came from the dry cleaning shop or not, the storage conditions of dry cleaned scarfs by consumers during the storage time periods (one to three days) would be significant for reducing VOC emissions.

A Study of Purity-based Page Allocation Scheme for Flash Memory File Systems (플래시 메모리 파일 시스템을 위한 순수도 기반 페이지 할당 기법에 대한 연구)

  • Baek, Seung-Jae;Choi, Jong-Moo
    • The KIPS Transactions:PartA
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    • v.13A no.5 s.102
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    • pp.387-398
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    • 2006
  • In this paper, we propose a new page allocation scheme for flash memory file system. The proposed scheme allocates pages by exploiting the concept of Purity, which is defined as the fraction of blocks where valid Pages and invalid Pages are coexisted. The Pity determines the cost of block cleaning, that is, the portion of pages to be copied and blocks to be erased for block cleaning. To enhance the purity, the scheme classifies hot-modified data and cold-modified data and allocates them into different blocks. The hot/cold classification is based on both static properties such as attribute of data and dynamic properties such as the frequency of modifications. We have implemented the proposed scheme in YAFFS and evaluated its performance on the embedded board equipped with 400MHz XScale CPU, 64MB SDRAM, and 64MB NAND flash memory. Performance measurements have shown that the proposed scheme can reduce block cleaning time by up to 15.4 seconds with an average of 7.8 seconds compared to the typical YAFFS. Also, the enhancement becomes bigger as the utilization of flash memory increases.

Effects of Ultrasonic Cleaning and Chemical Pre-treatment on the Characteristics of Fast-stabilized Rayon Fabrics (빠르게 안정화된 레이온직물의 특성에 미치는 초음파세척 및 화학전처리 영향)

  • Cho, Chae Wook;Cho, Donghwan
    • Journal of Adhesion and Interface
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    • v.14 no.3
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    • pp.146-159
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    • 2013
  • In the present study, stabilized rayon fabrics were prepared from fast isothermal stabilization processes, which were carried out within four minutes at $350^{\circ}C$. The effects of ultrasonic cleaning and chemical pre-treatment on the chemical composition, physical characteristics, X-ray diffraction pattern, thermal stability and shape of the stabilized rayon fabrics were investigated extensively. In order to reduce the weight loss and thermal shrinkage of rayon fabrics occurring during the stabilization process, ultrasonic cleaning was first conducted and then chemical pre-treatments using $NH_4Cl$, $Na_3PO_4$, $H_3PO_4$, and $ZnCl_2$ were performed, respectively. The results indicated that both ultrasonic cleaning and chemical pre-treatment influenced the weight loss, thermal shrinkage, microstructure, carbon content, thermal stability and fabric shape of stabilized rayon fabrics. Also the results depended on the fast-stabilization time and the type of chemical pre-treatment agents used.

Efficient Page Allocation Method Considering Update Pattern in NAND Flash Memory (NAND 플래시 메모리에서 업데이트 패턴을 고려한 효율적인 페이지 할당 기법)

  • Kim, Hui-Tae;Han, Dong-Yun;Kim, Kyong-Sok
    • Journal of KIISE:Computer Systems and Theory
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    • v.37 no.5
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    • pp.272-284
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    • 2010
  • Flash Memory differs from the hard disk, because it cannot be overwritten. Most of the flash memory file systems use not-in-place update mechanisms for the update. Flash memory file systems execute sometimes block cleaning process in order to make writable space while performing not-in-place update process. Block cleaning process collects the invalid pages and convert them into the free pages. Block cleaning process is a factor that affects directly on the performance of the flash memory. Thus this paper suggests the efficient page allocation method, which reduces block cleaning cost by minimizing the numbers of block that has valid and invalid pages at a time. The result of the simulation shows an increase in efficiency by reducing more block cleaning costs than the original YAFFS.

A Study on the Household Work Time's Change and Its Structure in Urban Home Makers (도시 가정주부의 가사노동시간변화와 구조에 관한 연구)

  • 김선희
    • Journal of the Korean Home Economics Association
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    • v.27 no.1
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    • pp.111-126
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    • 1989
  • The aim of the present study is to research into the household work time change and its structure in urban home makers by the choosen eleven studies and KBS's Data 1981, 1983, 1985, 1987. This study were proceeded under some limitations, it is choosen eleven studies that is different region: large city, medium and small town, and the household work's categories of original auther were changed. And KBS's Data was composed of general formation without personal character of home maker: FLC, number of childeren, family type, education, region. Although this study have a certain meaning of implementation, research into the household work time change and its's structure. The major findings of this study can be autlined as follows: (1) Total household work time did'nt so much changed through the choosen eleven studies compared with the last twenty years ago. In the change of each province household work time, time connected with meals and dwelling did not showed consistancy of change. But cloth laundering and mending time of 80's were declined compared with 70's. Family care time of 80's was increased, home management and buying time was declined untill '85, but again increasing trend '87. In choosen eleven studies, the household work time structure of urban home makers can be outlined: time connected with Meals>Family care>Cloth laundering and mending>Dwelling>Home management and Buying. (2) KBS's time-series data were analized as follows: a) Total household work time of '87 was declining gradually in weekday (34 minutes), sat. (41 minutes), sun (1 house and 2 minutes) compared with '81. b) The change of each province household work time: the time of cooking and sewing home management were declining gradually in its Mean time and its ratio of acters. The acter ratio of household worker in '81, '83, '85 was composed Cooking > Cleaning > Laundering > Home management > Buying > Child care > Sewing. In '87 was composed Cooking > Cleaning > Laundering > Buying > Home management > Child care > Sewing. c) The structure of household work time revealed some differences in each year and a day of the week.

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Effect of Interfacial Properties on the Detergency in Dishwashing Agent Composition (식기용 세정제 조성에 있어서 계면물성이 세정력에 미치는 영향)

  • Oh, Hyun-Joo;Lim, Hyo-Seon;Kim, Young-Ho
    • Applied Chemistry for Engineering
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    • v.31 no.2
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    • pp.193-199
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    • 2020
  • The effects of the composition of the dishwashing detergent on interfaces of the oil (O) and the aqueous (W) solution in addition to the cleaning effects of interfacial properties were investigated. Also, the cleaning power of the oil contaminated on the surface of the dish according to each composition and the residuals of the contaminants and the cleaning agent after the washing rinses were evaluated. The removal of contaminated oil on the solid (S) surface in the composition of the cleaning agents used in this study was strongly related to the interfacial properties between the W/O/S, and was particularly dependent on the forward and backward dynamic contact angles. When both contact angles were low at the same time, the permeability of the cleaning solution was so high that the contaminated oil showed a high removal effect. The smaller the interfacial tension of O/W was, the better emulsification of the contaminated oil, the higher the interfacial tension, and the poorer emulsification were achieved. However, the emulsification effect did not significantly affect the cleaning power. In particular, in the case of the cleaner having low interfacial tension, the cleaning material remained on the surface of the solid after washing.

Development of a Rotation Swab Pig Method for Cleaning Water Pipes (상수관의 세척을 위한 회전식 스왑피그 공법 개발)

  • Kicheol Lee;Jaeho Kim;Kisung Kim;Jeongjun Park
    • Journal of the Korean Geosynthetics Society
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    • v.23 no.2
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    • pp.63-75
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    • 2024
  • Drinking water is an essential element to ensure the basic human right to live, and the quality of clean water must always be ensured. However, domestic water facilities, which were installed intensively in the early 2000s, are deteriorating. The accidents such as discoloration of water such as chromaticity and turbidity as well as leakage of substances frequently occur. However, since it is virtually impossible to replace all water pipes, the detailed standards for maintenance of water pipe network facilities established in 2021 require water pipe cleaning. The swab pig method, one of the water pipe cleaning methods, is a method of physically removing substances in pipes and is evaluated as having the highest cleaning efficiency. However, Swab is highly likely to be damaged or deformed during the cleaning process, and may even be lost. Therefore, in this study, the material of the pig was changed to a material with high compressibility, and it was made as close as possible to the inner wall of the water pipe. And, to maximize cleaning efficiency, a rotation swab pig with a rotation blade was developed. In addition, high-strength wire and winding equipment were additionally developed to eliminate the possibility of loss and to determine the location of the pig. The inlet and outlet are connected with wires, and after verifying the performance of each detailed technology, the technology was applied on a test bed with a 30m section. As a result of the application, the performance of the technology was verified by measuring the process time and evaluating applicability.

Using RESRAD-BUILD for Potential Radiation Dose Estimation the Korea Research Reactor-1 When It Opens to the Public as a Memorial Hall

  • Lee, Sangbok;Yoon, Yongsu;Kim, Sungchul
    • International Journal of Contents
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    • v.16 no.2
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    • pp.102-108
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    • 2020
  • The purpose of this study was to estimate and analyze the potential radiation dose that the future visitors and the cleaning staff will be exposed to when the KRR-1 reactor is converted into a memorial hall. The radiation doses were estimated using the RESRAD-BUILD software, where case, building, receptor, shielding, and source parameters were applied as the input data. Also, the basic data for the assessment of the radiation doses were determined in an indirect manner using the data on the waste generated during the decommissioning process of the reactor. The assessment results indicate that the potential radiation dose to the visitors and the cleaning staff will be less than 1 mSv, the annual dose limit for the general public. However, if anyone for a significant period of time is close to the reactor, the overall dose will increase. The radiation dose for the future visitors and the cleaning staff was determined to be lower than the annual dose limit for the general public. Given such a risk, systematic measures, such as periodic monitoring or limiting hours, are imperative.

Dyeing Properties and Ultraviolet-cut Ability of Silk and Nylon Fabrics Dyed with Rhus verniciflua Extracts (옻나무 추출액에 의한 견직물, 나일론 직물의 염색성과 자외선 차단성)

  • Choi, In-Ryu
    • The Research Journal of the Costume Culture
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    • v.16 no.1
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    • pp.158-165
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    • 2008
  • The purpose of this study was to investigate the dyeing property and ultraviolet-cut ability on silk 100% and nylon 100% fabrics dyed with Rhus verniciflua extracts. This study was investigated K/S values, surface color, washing fastness, dry cleaning fastness and ultraviolet-cut ability of the silk and nylon fabrics dyed with Rhus verniciflua extracts under the various dyeing conditions. As mordanting were used Tin(II) Chloride dihydrate $(SnCl_2{\cdot}2H_2O)$, Copper(II) sulfate pentahydrate$(CuSO_5{\cdot}5H_2O)$, Iron(II)Chloride$(FeC_2{\cdot}4H_2O)$. pH was adjusted by sodium carbonate$(Na_2CO_3)$ and formic acid(HCOOH). The optimum dyeing temperature, dyeing time, and pH of the silk fabrics dyed with Rhus verniciflua extracts were $90^{\circ}C$, 100min, and in the nylon fabrics were $90^{\circ}C$, 45min. It were colored(munsell value) 6.4Y 7.5/4.1 in the silk fabrics and colored 4.3Y 6.6/5.9 in the nylon fabrics dyed with Rhus verniciflua extracts. Washing fastness and dry-cleaning fastness in the silk and nylon fabrics dyed with mordanting agent improved in $4{\sim}5$ grade. UV-A test showed that nylon fabrics a high rate of 92% with Rhus verniciflua extracts.

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Seismic Qualification of the Air Cleaning Units for Nuclear Power Plant Ulchin 5&6 (울진 원자력발전소 5,6 호기용 공기정화기에 대한 내진검증)

  • Kim, Jin-Young;Rhee, Hui-Nam;Lee, Joon-Keun
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.26 no.7
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    • pp.1376-1383
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    • 2002
  • Seismic qualification of the Air Cleaning Units for nuclear power plant Ulchin 5&6 has been performed with the guideline of ASME Section III and IEEE 344 code. By using the structural and geometrical similarity analysis, the three models to be analyzed are condensed into a single model and, at the same time, the excitation forces and other operating loads for each model are encompassed with respect to different loading conditions. As the fundamental frequencies of the structure are found to be less than 33Hz, which is the upper frequency limit of the seismic load, response spectrum analysis using ANSYS is performed in order to combine the modal stresses within the frequency limit. In order to confirm the structural and electric stability of the major components, modal analysis theory is adopted to derive the required response spectrum at the component locations. As the all combined stresses obtained from the above procedures are less than allowable stresses and no mechanical or electrical failures are found from the seismic testing, the authors confirm the safety of the nuclear equipments Air Cleaning Units studied in this paper.