• 제목/요약/키워드: Washing time

검색결과 673건 처리시간 0.028초

졸-겔 방법으로 제조된 Ammonium Diuranate 핵연료 분말의 공정장치 변수에 따른 특성 (Characteristics of the Ammonium Diuranate Powders Prepared with Different Experimental Apparatus in Sol-gel Process)

  • 김연구;정경채;엄성호;조문성
    • 한국분말재료학회지
    • /
    • 제19권6호
    • /
    • pp.398-404
    • /
    • 2012
  • This paper describes the spherical ammonium diuranate gel particles which are the intermediated material of the $UO_2$ microsphere for an VHTR(very high temperature reactor) nuclear fuel. The characteristics of the intermediate-ADU gel particles prepared by AWD(ageing, washing, and drying) and FB(fluidized-bed) apparatus were examined and compared in a sol-gel fabrication process. The electrical conductivity of washing filtrate from the FB treating and the surface area of dried-ADU gel particles were higher than those of AWD treating. Also, an internal pore volume in dried-ADU gel particles showed a more decrease in AWD treatment than FB treatment because of decomposition of PVA affected by the washing time. However, the internal microstructures of ADU gel particles were similar regardless of the process variation.

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

  • 최인려
    • 복식문화연구
    • /
    • 제16권1호
    • /
    • pp.158-165
    • /
    • 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.

  • PDF

유기산 추출에 의한 철 폐광산 오염토양의 복원 (Ex-situ Remediation of a Contaminated Soil of Fe Abandoned Mine using Organic Acid Extractants)

  • 정의덕;강신원;백우현
    • 한국환경과학회지
    • /
    • 제9권1호
    • /
    • pp.43-47
    • /
    • 2000
  • A study on the remediation of heavily for ion contaminated soils from abandoned iron mine was carried out, using ex-situ extraction process. Also, oxalic acid as a complex agent was evaluated as a function of concentration, reaction time and mixing ratio of washing agent in order to evaluate Fe removability of the soil contaminated from the abandoned iron mine. Oxalic acid showed a better extraction performance than 0.1N-HCl, i.e., the concentrations of Fe ion extracted from the abandoned mine for the former at uncontrolled pH and the latter were 1,750 ppm and 1,079 ppm, respectively. The optimum washing condition of oxalic acid was in the ratio of 1:5 and 1:10 between soil and acid solution during l hr reaction. The total concentrations of Fe ion by oxalic acid and EDTA at three repeated extraction, were 4,554 ppm and 864 ppm, respectively. The recovery of Fe ions from washing solution was achieved, forming hydroxide precipitation and metal sulfide under excess of calcium hydroxide and sodium sulfide. In addition, the amounted of sodium sulfide and calcium hydroxide for the optimal revovery of Fe were 15g/$\ell$ and 5g/$\ell$ from the oxalic acid complexes, respectively.

  • PDF

수용성 약물인 세파클러를 함유하는 젤라틴 마이크로캅셀의 제조 및 약물 방출특성 (Preparation of Cefaclor-Containing Gelatin Microcapsules and Their Drug Release Characteristics)

  • 조성완;박종화;박준상;장정수;최영욱
    • 약학회지
    • /
    • 제41권1호
    • /
    • pp.30-37
    • /
    • 1997
  • In order to formulate a controlled release system for oral drug delivery, the microcapsules were prepared in w/o emulsion containing cefaclor as a water-soluble model drug by th e method of interfacial polycondensation. Gelatin wis selected as a suitable polymer for interfacial polycondensation. Gelatin solution containing drug was emulsified in an organic phase under mechanical stirring. After emulsification, terephthaloyl chloride was added as cross linking agent, followed by mechanical stirring, washing and drying. Physical characteristics of microcapsules were investigated by optical microscopy, scanning electron microscopy and particle size analysis. Mean particle sizes of gelatin microcapsules were, in the range, of about 20~50 ${\mu}$m. The microcapsules were in good apperance with spherical shapes before washing, but were destroyed partially after washing and drying, even though some microcapsules were still maintained in their shapes. Contents of cefaclor in the microcapsules were calculated by UV spectrophotometry after 3 days extraction with pH 4 carbonate buffer solution. The effects of cross linking time. pH. concentration of cross-linking agent, and temperature on drug release kinetics have been discussed extensively.

  • PDF

인산 부식액의 수세가 교정용 접착레진의 전단결합강도에 미치는 영향 (THE EFFECT OF WASHING PHOSPHORIC ACID ETCHANT ON SHEAR BOND STRENGTH OF AN ORTHODONTIC ADHESIVE)

  • 김희균;이기수;박영국
    • 대한치과교정학회지
    • /
    • 제26권5호
    • /
    • pp.497-507
    • /
    • 1996
  • 산부식된 법랑질표면의 오염은 브라켓의 레진 접착력에 영향을 미친다고 보고되어 왔다. 이 연구의 목적은 인산액이 법랑질과 반응하여 수용성염 및 불수용성염을 형성하는 경우와 부식표면이 타액오염된 경우에, 이의 수세시간이 브라켓의 레진접착 전단결합강도에 미치는 영향을 관찰하기 위하여 시행되었다. 치과 교정치료를 목적으로 발거된 총 234개의 상하악 소구치를 대상으로 $37\%$ 인산액으로 60초간 부식한 군, $20\%$ 인산액으로 50초간 부식 한 군, $37\%$ 인산액으로 60초간 부식 하고 타액오염시킨 군으로 나누고, 인산부식군은 각각 0초, 5초, 10초, 20초간 수세하고, 타액오염 군은 0초, 20초,30초 수세하거나, 재부식후 5초, 10초, 20초간 수세한후 레진접착제로 브라켓을 접착하였다. 5각군의 법랑질표면을 주사전자현미경과으로 검경하고, 전단결합강도를 측정하여 비교검토한 결과 다음의 결과를 얻었다. 1) 산부식후 수세를 하지않으면 레진접착제의 전단결합강도가 현저히 감소 하였다. 2) $37\%$ 인산부식액으로 부식시키고 5초, 10초, 및 20초간 수세한후의 접착레진 전단결합강도 사이에는 차이가 없었다. 3) $20\%$ 인산액으로 부식시키고 5초, 10초, 및 20초간 수세한 후의 전단결합강도사이에는 차이가 없었으나, 5초간 수세후의 전단결합강도는 측정치의 변이가 매우컸다. 4) 부식후 타액으로 오염된 법랑질 표면은 5초, 20초간 및 30초간 수세후 및 재부식 한 후의 브라켓접착레진의 전단결합강도사이에 차이가 없었으나, 5초간 수세만한 군의 전단결합강도는 변이가 매우컸다. 이상의 결과에 의하면 수용성 염이 생성되는 농도의 인산액으로 부식하고 5초간 수세후 불수용성 염이 생성되는 농도의 인산액으로 10초간 수세후에, 그리고 타액오염된 부식표면을 재부식없이 20초간 수세후에 브라켓을 접착하면 임상적으로 유용한 부라켓 접착레진의 전단 결합강도를 얻을수 있을 것으로 추정된다.

  • PDF

간호사의 손씻기에 대한 지식 및 태도 연구 (A Study on Handwashing Knowledge and Attitudes of Nurses)

  • 임현자
    • 간호행정학회지
    • /
    • 제2권2호
    • /
    • pp.5-16
    • /
    • 1996
  • The purpose of this study is to identify the handwashing knowledge and attitudes of resistered nurses on general wards. Subjects for this study include 182 nurses working in general wards of a hospital in Seoul area. Data were collected by a questionnaire from July 30 to August 10,1996. Statistical analyses were done by the SPSS/PC program. The techniques used in this sudy included frequencies, chi-square test. The results of this study are summarized as follows. 1. 34.6% of the respondents reported that they washed their hand an average of 5 to 7 times during the work day. 2. 38.5% of the respondents reported always washing after each patient contact. Only 9.9% always washed before contact with a patient. 3. 56.6% of the respondents reported a washing time of 10 to 20 seconds, whereas 29.1% washed 21 to 30 seconds. Chi-square tests were employed to determine any differences in handwashing frequency and duration by age, working years, work position. There were no satistically significant differences among the variables. 4. 95.6% of the subjects used water and plain soap during the washing process. The respondents washed the palms of the hands, the backs of their hands and between their fingers(33%). Only 17.6% removed rings before handwashing. Similarly, 11% removed their wristwatch. The majority(96.2%) reported that they used communal textile towel to dry their hands. When asked what method they used to turn off the water faucet after washing, 98.4% reported using direct hand-to-faucet contact. 5. Nursing activities that showed the highest handwashing rates was after wound dressing(22.9%), followed by suctioning(21.4%), injection(21.2%), inserting catheter(18%). 6. Reasons cited for reduced handwashing frequency included being too busy to wash more often(74.7%), no need to wash more often(11.0%) and dry skin caused by frequent handwashing(3.3%). 7. When asked where they obtained their current knowledge of handwashing techniques, they reported professors(73.6%), resisted nurses(14.8%) and supervisor(6.6%). 8. Nursing staff thought that proper handwashing was important factor in decreasing nosocomical infections(72.4%).

  • PDF

우라늄으로 오염된 자갈의 제염 (Decontamination of Uranium-Contaminated Gravel)

  • 박욱량;김계남;김승수;문제권
    • 방사성폐기물학회지
    • /
    • 제13권1호
    • /
    • pp.35-43
    • /
    • 2015
  • 선행핵연료 주기관련 시설의 해체/복원 시 방사능으로 오염된 다량의 자갈폐기물이 발생할 수 있다. 하지만 현재 방사성 오염 자갈을 제염하기 위한 기초자료가 부족하므로, 본 연구에서는 토양세척법을 응용하여 방사능 오염 자갈을 제염하는데 필요한 기초실험을 수행하였다. 효율적인 제염을 위하여 제염제를 비교하여 선정하였는데, 우라늄으로 오염된 자갈의 제염제로는 증류수나 계면활성제보다 0.1 M의 질산을 사용하였을 때 제염이 잘 되었다. 또한, 제염효율을 높이고 제염시간을 단축하기 위하여 우라늄 오염 자갈을 파쇄/분쇄한 후 세척한 결과, 입자의 크기가 작으면 작을수록 제염효율이 높고 자체처분허용농도를 만족하는 것으로 나타났다.

소비자 체험조사를 통한 타월 만족도 분석 연구 (Towel Experience and Consumer Satisfaction)

  • 송경헌;허미옥
    • 한국생활과학회지
    • /
    • 제19권6호
    • /
    • pp.1063-1070
    • /
    • 2010
  • This study examined 12 types of towels with differing fabric material, function, quality, printing, pile length, twist, etc. from a towel company which manufactures and distributes products domestically. After 3 months of use by consumers, a consumer satisfaction survey was administered and results analyzed. Four types of towels were assigned to each group and the towels were used every day for 3 months. Participant feelings after using the towel for the first time and after using it for three months were investigated. The questionnaire consisted of 26 questions on a 5-point Licket-type scale. The first 13 questions measured perceptions of absorption, touch, fine fiber loss, contamination, deformation, drying speed, and design. Other questions compared differences between the two towel types in terms of their material, function, quality, printing, pile length, and degree of twisting. Results showed that, with regards to weight, consumers preferred towels between 130~150g and a thickness of around 1.7~1.8mm. The bamboo towel was considered superior to the cotton towel in terms of sense of touch and did not happen linter after washing. The antibacterial towel was considered better than the cotton towel in terms of absorption but in terms of contamination, participants felt the antibacterial towel became dirty more easily than the cotton towel. We thought that it might be influence of the color of towel. Low-quality towels became stiffer and misshapen more easily than higher-quality towels. But the study showed that the consumers did not perceive significant differences in the towels' quality. Printed towels became thinner and their color changed more with washing. The consumers preferred the design of jacquard towels to printed towels. Towels with short piles was happened more linter than the towel with long pile after washing. Non-twisted towel were better than the highly-twisted towel in terms of sense of touch and absorption but the non-twisted towel happened more linter after washing and became dirty more easily.

대두섬유의 천연염색에 관한 연구 - 오배자를 중심으로 - (Natural dyeing of Soybean Protein Fabrics - Gallnut -)

  • 노영주;이신희
    • 한국의류산업학회지
    • /
    • 제16권3호
    • /
    • pp.462-468
    • /
    • 2014
  • This study investigates the dyeability of soybean protein fabric after dyeing with gallut. In this study, the colorants of gallnut were extracted with boiling water at $60^{\circ}C$ and 60min. Soybean protein fabric was dyed with extracted solution from gallnut according to concentration, temperature and time. After dyeing with gallut solution, dyeability (K/S) was obtained by CCM observation. Al, Cu and Fe were employed as a mordanting agents. Various color changing were produced by the interactions of mordants that were different from soybean protein fabric; however, Al mordant was not indicated as a variable color change. Fastness to washing and light were also investigated. Consequently, the dyeability of the soybean protein fabric dyed with gallut showed reasonable results at 100% o.w.f, $90^{\circ}C$, for 60min. Fastness to washing according to concentration indicated good result as more than grade (4-5) in general. Fastness to light was almost the same compared to fastness to washing at all concentrations. Fastness to washing according to mordants indicated good grade (4) in principle at Al, Cu, and Fe; in addition, fastness to light indicated a good grade too. Fastness to light also indicated the highest dyeability at Fe mordant. This study shows that gallut is a reasonable dyestuff to soybean protein fabric and that it is possible to manufacture a variety of products that use soybean protein fabric.

건조 일체형 드럼세탁기의 건조 조건에 따른 정전기 특성 (Electrostatic Characteristics of the Washer-dryer Combination under Various Drying Conditions)

  • 정승은;박정희;윤창상
    • 한국의류학회지
    • /
    • 제30권5호
    • /
    • pp.753-761
    • /
    • 2006
  • This paper suggests the optimal conditions for the laundry to prevent from the electrostatic charge by the evaluation of the electrostatic characteristics in the full process of washing and drying. Cotton, nylon, and polyester fabrics were used as test washing specimens. Detergent and softener were used under the standard washing cycle, and then the electrostatic characteristics of laundry were measured. The results showed that the moisture regain decreased and the electrostatic charge increased with the drying time. It was observed that the specimen fabrics were already dried up before the standard drying cycle was finished. Consequently, the excessive drying caused a generation of electrostatic charge due to the removal of the trace of moisture remaining and the excessive friction. Especially, the softener played an important role to prevent from a generation of electrostatic charge, whose insertion was more effective in the drying than in the rinsing process. It was also shown that the electrostatic charge could be decreased by drying the fabrics of one kind. On the other hand, for drying the mixed kinds of fabrics, the electrostatic charge increased remarkably. Therefore we suggest that the laundry be classified according to the kinds of fiber, and then be washed and dried before excessive drying to reduce electrostatic charge And further, a proper use of softener is effective to reduce electrostatic charge.