• Title/Summary/Keyword: Washing time

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Microbiological Assessment of Home-Delivered Meals for Children from Low-income Families during Production and Delivery (결식아동을 위한 가정배달 도시락의 생산과 배달과정 중 미생물적 평가)

  • Moon, Jeong-A;Yoo, Chang-Hee;Lee, Kyung-Eun
    • Journal of the Korean Dietetic Association
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    • v.19 no.3
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    • pp.236-252
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    • 2013
  • The purpose of this study was to assess the microbiological quality of home-delivered meals during production and delivery for children from low-income families. Production flows from a facility in Seoul that provides home-delivered meals were analyzed and the time-temperature of the food was measured. Microbiological assessment was performed for the production environment, personal hygiene, and food samples at each production and delivery step based on the process approach. It took 2 hours or longer from completion of production to meal delivery. An aerobic colony count (ACC) and coliform were not detected at knives, cutting boards, and dish towels. However, ACC (at pre-preparation, preparation, and packing areas) and coliform (at the preparation area) were detected on the hands and gloves of employees. Air-borne bacterial counts varied according to day and preparation area (ND~6 CFU/plate/15 min). Food temperatures, on the completion of production and meal delivery, fell into temperature danger zones. ACC and coliform counts of raw ingredients did not decrease after pre-preparation (washing and sanitizing) for menus involving food preparation with no cook step. ACC decreased after cooking step for menus of food preparation with cook step, but the ACC of the stir-fried and seasoned dried filefish fillet on the completion of cooking was too numerous to count due to improper heating. The ACC of seasoned young Chinese cabbages (a menu with complex food preparation) increased during delivery (from 2.5 log CFU/ml to 5.0 log CFU/ml). This qualitative assessment of foodborne pathogens revealed that B. cereus was detected in vegetable and meat product menus. These results suggest time-temperature control is necessary during production and delivery and management guidelines during production of home-delivered meals are provided for safe production.

Natural Dyeing of Fabrics with Guava (Psidium guajava L.) Leaf Extract III - Dyeability and Functional Property of Hanji Cotton Fabrics - (구아바 잎 추출액을 이용한 직물의 천연염색 III - 한지면직물의 염색성과 기능성 -)

  • Han, Mi Ran;Lee, Jeong Sook
    • Fashion & Textile Research Journal
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    • v.14 no.5
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    • pp.866-877
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    • 2012
  • The natural dyeing of hanji cotton fabrics with guava leaf extract was investigated. The temperature and time of dyeing were $40^{\circ}C$ and $90^{\circ}C$ for eighty minutes, respectively. In addition, the dyebath has been set at pH 5. Sn pre-mordanted fabrics showed the highest K/S value. Regardless of dyeing temperature, K/S values were high when Al, Cu, Fe-mordanted fabrics were dyed in post-mordanting and Sn-mordanted fabrics in pre-mordanting. The dyeing equilibrium was shown at the fourth time of repeated dyeing. In the processing of hanji cotton fabrics, K/S value was high when hanji cotton fabric was treated with soybean milk at $90^{\circ}C$. Similar K/S value of dyeing was shown when fabrics were processed with chitosan, regardless of dyeing temperature. High K/S value of dyeing was seen when fabrics processed with gallnut tannin at 40. Fabrics dyed with acidic water extract showed yellowish color. Fabrics dyed with alkaline water extract showed reddish color, and fabrics dyed with ethanol extract showed greenish yellow color. In case of Sn-mordanted fabrics, the washing fastness level was between 3 to 4, and other dyed fabrics showed low fastness. The dry cleaning fastness also showed very excellent result with level 4-5. The rubbing fastness of the fabrics was better in dry rubbing than in wet rubbing. For the light fastness, all dyed fabrics showed low fastness. For antibacterial activity, the dyed fabrics with guava leaf extract showed 99.9% of high antibacterial activity. Hanji cotton fabric maintained certain deodorization in the state of raw fabric. All dyed fabrics showed higher UV protection rate than control fabric.

Natural Dyeing of Silk Fabrics with the Extract of Alnus firma Tree Branches (사방오리나무가지 추출액을 이용한 견직물의 천연염색)

  • Ha, Young Kab;Lee, Jeong Sook
    • Fashion & Textile Research Journal
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    • v.19 no.3
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    • pp.337-343
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    • 2017
  • The purpose of this study is to investigate the optimal dyeing conditions and human-friendly properties of the extract from the branches of Alnus firma tree which is widely used for forestation and to provide basic information for quantification and commercialization of natural dyeing by discovering such as dye material. The optimal dyeing conditions, as a result, were shown at 100% of dye concentration, $90^{\circ}C$ of dyeing temperature and 40 minutes of dyeing time. In terms of dye uptake depending on the mordanting methods, it showed the best result in order of Fe, Sn, Cu and Al at pre-mordanting while found strong in order of Fe, Cu, Al and Sn at post-mordanting. Color fastness to washing and dry cleaning was found strong at grade 4-5 and fastness to light was rated at 2. The grade of change in color to rubbing and perspiration was good at 4-5. In aspects of functional properties, it showed excellent results of 98% deodorization rate at 120 minutes of dyeing time, 96.1% UV protection rate and 99.9% bacterial reduction against Staphylococcus aureus and Klebsiella pneuminiae. It is considered, therefore, the extract from Alnus firma tree is of great value as an eco-friendly natural dyestuff.

Natural Dyeing of Fabrics with Corydalis Tuber Extract - Dyeability and Functionality of Wool Fabrics - (현호색 추출액을 이용한 직물의 천연염색 - 모직물의 염색성과 기능성 -)

  • Kim, Kwan-Young;Lee, Mun-Soo
    • Fashion & Textile Research Journal
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    • v.19 no.5
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    • pp.620-625
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    • 2017
  • In this study, the dyeing conditions(temperature, time, concentration) are changed from various conditions on wool fabrics by using corydalis tuber extract in order to develop new natural dyes. The purpose of this study is to improve the dyeability, color fastness, and functionality and to derive optimal dyeing conditions by comparing and analyzing the changes of K/S values and surface color by dyeing pH changes, mordant method, and mordant type. As a result of the experiment, the optimum dyeing condition of the wool fabrics is shown dyeing temperature:$80^{\circ}C$, dyeing time:90min, dyeing concentration:100%. The dyeability by pH variants of corydalis tuber extract indicates that K/S values is higher alkaline than acidic. The mordant method of corydalis tuber extract showed pre-mordant has high K/S values. In terms of color fastness, marked improvement has not been shown despite of mordant treatment on wool fabrics. In particular, color change of color fastness to washing, color fastness to light indicates the low fastness. In addition, the functionality such as antibacterial activities and deodorization can be given at dyeing with corydalis tuber extract thus it is expected to be applied to underwear or apparel products for the elderly and infirm and children with weak skin that required high functionality.

Evaluation of a Diffusive Sampler for the Measurement of Formaldehyde using Colorimetric Method (흡광광도법을 이용한 포름알데히드 확산측정기의 평가)

  • Yim, Bong-Been;Kim, Sun-Kyu;Jung, Eui-Suk;Kim, Sun-Tae
    • Journal of Korean Society of Environmental Engineers
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    • v.27 no.6
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    • pp.606-613
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    • 2005
  • The badge-type diffusive sampler for the measurement of formaldehyde in indoor air using three types of colorimetric methods such as chromotrophic acid(CTA), 3-methyl-2-benzothiazolinone hydrazone(MBTH), and 4-amino-3-hydrazino-5-mercapto-1,2,4-triazole(AHMT) method. The washing of the collection filter with several cleaning solution was effected with satisfactory results, regardless of the types of cleaning solutions. The concentrations of absorbance solution in each colorimetric method were experimentally determined by considering the sampling rates. The variation blank values in each colorimetric method was below 15%. As compared with CTA and AHMT methods, the reproducibility of MBTH method was excellent and was below 10% relative standard deviation. The collected formaldehyde mass and time-weighted concentration had a good correlation (correlation coefficient > 0.93). The limit of detection and limit of quantitation, and minimum sampling time were closely correlated to the sampling rates for the measurement of formaldehyde in each method.

Development of a Method for Rapid Analysis of DNA Hybridization (측방유동방식 신속 DNA 교잡 분석법의 개발)

  • 정동석;최의열
    • Korean Journal of Microbiology
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    • v.39 no.2
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    • pp.114-117
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    • 2003
  • In molecular biology, it is necessary to develop an easy and rapid method to identify a specific DNA sequence. Though Southern and Northern blot techniques have been used widely for the analysis of gene structure and function, those methods are inconvenient in the points that we need to control incubation temperature, time, and other parameters to get the final result. In this study, we report a new method for the rapid analysis of specific DNA sequence with the modification of an immunochromatographic method. The lateral flow DNA analysis strip is composed of a sample pad, a nitrocellulose membrane for the separation and propagation of analytes, and an absorption pad for the generation of capillary action. Capture DNA was immobilized on the membrane by UV cross-linking and target DNA was labeled with Cy-5 for signaling. The samples containing target DNA were applied onto the sample pad, incubated for 15 min for separation, and scanned with a GSI fluorescence scanner. Though the hybridization reaction occurs in a short time without any washing steps, there appears to be little cross hybridization between the different sequences. The result showed a possibility that the new method can be used for the rapid identification of specific DNA sequence among the samples.

Suggestion of Segregation Evaluation Method based on Evaluation Index for Segregation(EIS) (재료분리 평가정수(EIS)에 의한 재료분리 평가법의 제안)

  • Han, Cheon-Goo;Kim, Gi-Cheol;Park, Byung-Kwan
    • Proceedings of the Korea Concrete Institute Conference
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    • 2008.11a
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    • pp.923-926
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    • 2008
  • Currently more high flow and high performance concrete is used for construction of buildings in the world. However, when high flow and high performance concrete put high performance water reducing agent in quantity to improve flow, it has a negative effect on concrete structures since segregation arises from it though flow will be improved. There are naked-eye observation, coarse aggregate washing test, L Flow test for permeation among reinforcing rods and measurement of viscosity to judge concrete segregation resistance. However, it is difficult to apply them to practical affairs since they are very complicated and troublesome. Therefore, the study analyzed EIS dividing slump flow value into slump value, how to valuate concrete segregation resistance more easily, on the basis of the existing reference materials to propose EIS. As the results, in the event of high flow concrete, it is desirable that EIS value is prescribed to be less than 2.5 at the time of managing segregation. Also, at the time of prescribing EIS with performance, it is judged that it is desirable to manage segregation as less than 2.2 (Grade 1), 2.2$\sim$2.4 (Grade 2) and more than 2.6 (Grade 3).

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Analysis of Operation Parameters of Pilot-Scale Packed-Absorption System for Airborne Methyl Ethyl Ketone Control (공기 중 메틸에틸케톤 제어를 위한 Pilot-Scale 흡수 시스템의 운영인자 분석)

  • Jo, Wan-Kuen;Kim, Wang-Tae
    • Journal of Environmental Science International
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    • v.20 no.4
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    • pp.501-509
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    • 2011
  • Unlike many laboratory-scale studies on absorption of organic compounds (VOCs), limited pilot-scale studies have been reported. Accordingly, the present study was carried out to examine operation parameters for the effective control of a hydrophilic VOC (methyl ethyl ketone, MEK) by applying a circular pilot-scale packed-absorption system (inside diameter 37 cm ${\times}$ height 167 cm). The absorption efficiencies of MEK were investigated for three major operation parameters: input concentration, water flow rate, and ratio of gas flow-rate to washing water amount (water-to-gas ratio). The experimental set-up comprised of the flow control system, generation system, recirculation system, packed-absorption system, and outlet system. For three MEK input concentrations (300, 350, and 750 ppm), absorption efficiencies approached near 95% and then, decreased gradually as the operation time increased, thereby suggesting a non-steady state condition. Under these conditions, higher absorption efficiencies were shown for lower input concentration conditions, which were consistent with those of laboratory-scale studies. However, a steady state condition occurred for two input concentration conditions (100 and 200 ppm), and the difference in absorption efficiencies between these two conditions were insignificant. As supported by an established gas-liquid absorption theory, a higher water flow rate exhibited a greater absorption efficiency. Moreover, as same with the laboratory-scale studies, the absorption efficiencies increased as water-to-gas ratios increased. Meanwhile, regardless of water flow rates or water-to-gas ratios, as the operation time of the absorption became longer, the pH of water increased, but the elevation extent was not substantial (maximum pH difference, 1.1).

A study on the Correlationship between Detergency of Commercial Detergents and Rolling-up (시판세제의 세정성과 Rolling-up의 상관성에 관한 연구)

  • Lee Kyung Mi;Cha Ok Seon
    • Journal of the Korean Society of Clothing and Textiles
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    • v.10 no.3
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    • pp.27-36
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    • 1986
  • The purpose of this study was, to estimate the detergency of commercial detergent and to examine the interrelationship between detergency and detergent characteristics, detergent concentration, fiber characteristics, and Rolling-up phenomenon which is the major removal mechanism of oily soil. A mixture of oleic acid-olive oil was used as oily soil. The detergency was estimated by analysis of oleic acid on cotton ana polyester fabrics before and after washing by means of liquid scintillation counting. The Rolling-up of oily soil from PET film was observed and change of contact angle and removal time were measured. The results were as follows ; 1. In the case of soaps and powder synthetic detergents, the optimum concentrations we-re about $0.2\~0.3\%$. And detergencies of liquid synthetic detergents were considerably low, and the detergency was continually increased up with increasing concentration to $0.5\%$, which seemed to be caused by the lower pH than that of soap and powder synthetic deter-gent solutions. 2. As the effect of external or internal fiber structure; the detergency of cotton was lower than that of polyester. 3. In the observation of Rolling-up, the contact angle increased and the Rolling-up time became shorter with increasing detergent concentrations ($0.05\~0.5\%$). And it was confirmed that detergency was increased with Rolling-up effect. In addition, the study on the actual laundry condition was studied using the questionaire. From the results, about $76\%$ of households used the concentration of detergent roughly or excessively and housewives were highly concerned on the recommended dose, but grade of practice were very low.

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Natural Dyeing of Fabrics with Guava (Psidium guajava L.) Leaf Extract - Characteristics of Guava (Psidium guajava L.) Leaf Extract and Dyeability with Silk Fabrics - (구아바 잎 추출액을 이용한 직물의 천연염색(I) - 구아바 잎 추출액의 특성과 견직물에 대한 염색성 -)

  • Han, Mi-Ran;Lee, Jeong-Sook
    • Fashion & Textile Research Journal
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    • v.13 no.5
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    • pp.778-789
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    • 2011
  • The natural dyeing of silk fabrics with guava leaf extract was investigated. Mixed components of flavonoid and tannin seem to be the components of guava leaf extract. The temperature and time for dyeing of silk fabrics with guava leaf extract were $40^{\circ}C$ and $90^{\circ}C$ for eighty minutes, respectively. The dyeing equilibrium was shown at the fourth time of repeated dyeing. The highest K/S value was recorded at pH 3. Fe-mordanted fabrics showed the highest K/S value. High K/S values were shown in the post-mordanting of dyed fabrics at $40^{\circ}C$ and the pre-mordanting of dyed fabrics at $90^{\circ}C$. After repeated dyeing and mordanting, various color change occurred with mordant treatment. Surface colors were changed to YR color in alkaline water extract and to Y color in acidic water and ethanol extract, respectively. The washing fastness was level 3-4 for Sn-mordanted fabrics and level 4 for Fe-mordanted fabrics, and the dry cleaning fastness also showed very excellent result with level 4-5. The rubbing fastness was satisfactory with level 3-4. The light fastness was above level 4 only when Fe-mordanting was conducted, and the rest of dyed fabrics was not fast enough. In the antibacterial activity, the powder of guva leaf extract showed 99.9% of high antibacterial activity and Staphylococcus aureus showed 99.6% in dyed fabric. All dyed fabrics showed higher deodorization and UV protection rate than control fabric.