• Title/Summary/Keyword: wet and dry treatment

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Development of Pre-treatment for Tin Recovery from Waste Resources (주석 함유 폐자원의 공정부산물 전처리 기술)

  • Jin, Y.H.;Jang, D.H.;Jung, H.C.;Lee, K.W.
    • Journal of Powder Materials
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    • v.21 no.2
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    • pp.142-146
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    • 2014
  • Fundamental experiences have been studied for development of pre-treatment process of Sn by-products such as solders. Dry and wet separation/recovery processes were considered by the differences of physical properties. The by-products, which are analyzed by solder metal and oxides. The metal and oxide were simply separated by dry ball-milling process for 12 hours, after that recovery metal powder might be reusable as lead or lead-free solders. In terms of wet separation process, samples were dissolved in $HNO_3+H_2O_2$ and the precipitation were analyzed by $SnO_2$. Overall efficiency of recovery might be increasing via developing simple pre-treatment process.

Literature Investigation Regarding Cupping Therapy and Analysis of Current Professional's Cupping Treatment (부항요법에 대한 문헌고찰 및 부항시술 현황 조사)

  • Lee, Byeong-Yee;Song, Yun-Kyung;Lim, Hyung-Ho
    • Journal of Korean Medicine Rehabilitation
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    • v.18 no.2
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    • pp.169-191
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    • 2008
  • Objectives : This study was performed to report the present situation of the cupping treatment to make standardization of cupping treatment in Korea. Methods : We searched relevant case reports, surveys, and review articles using a databases of online bibliography. And we had research to oriental medical doctor with questionnaire about the cupping treatment. Results : 1. Cupping treatment is used for diagnoisis, protection and treatment for many kinds of diseases such as musculoskeletal diseases, internal diseases, sequela of cerebral attacks and so on in Korea. 2. Adequate cupping area is the area of lesion. 3. Cupping time and pressure are various. 4. Adequate amount of venesection is 10cc. 5. Adequate dry cupping term is 1 time/day and adequate wet cupping term is 1 time/2~3days. 6. Cognition of adverse reaction of cupping treatment is different among the doctors. 7. Method of disinfection of cup is different among the doctors. Conclusions : The result of this study will help to make the a guideline of cupping treatment. And we have to go ahead studying to make standardization of cupping treatment.

THE EFFECT OF MOISTENING OF ETCHED DENTIN AND ENAMEL SURFACE ON THE MICROLEAKAGE OF COMPOSITE RESINS (복합레진 수복시 상아질 표면 처리가 미세 변연 누출에 미치는 영향에 관한 연구)

  • Jeon, Cheol-Min;Kwon, Hyuk-Choon;Lee, Chung-Sik;Lee, Myung-Jon;Um, Chung-Moon
    • Restorative Dentistry and Endodontics
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    • v.21 no.1
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    • pp.321-338
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    • 1996
  • The purpose of this study was to evaluate the effect of moistening and air-drying of acid conditioned dentin and enamel on the marginal microleakage. In this study, Class V cavity were prepared on both buccal and lingual surface of sixty extracted human premolars with cementum margin. These specimens were randomly devided into three groups and three dentin adhesives(Scotchbond Multi-Purpose, All bond 2, Prisma Universal Bond 3) were applied to each group. The specimens in each group were subdevided into four groups (Wet/primed, Dry/primed, Wet/not primed, Dry/not primed) and the etched dentin and enamel surface were treated these four surface treatments prior to the placement of a bonding agent or adhesive. Wet/primed group was simply blot-dried with a damp facial tissue before primer placement ; Dry/primed group was air dried for 30 seconds before the placement of a primer ; Wet/not primed group and Dry/not primed group were not primed after blot dried and air dried for 30 seconds each group. The bonding agent and composite resin were applied for each group. All specimens were exposed to 500 cycle of thermal stress. Specimens were placed in a silver nitrate solution and then sectioned buccolingually through the center of the restoration. The dye penetrations of the specimens were observed with a stereo microscope. The statistical test were applied to the results using a one way analysis variance (ANOVA) and Duncan's multiple range test. The aspects of silver ion penetration into the resin/dentin interface were examined under scanning electron microscopy. The results were as follows. 1. In all groups, the enamel margin showed significantly lower leakage value than the cementum margin (p<0.05). 2. Regardless of various surface treatment and dentin adhesives, there was no significant difference at the enamel margins (p>0.05). 3. At the dentin margins, the leakage values of Dry/not primed group showed significantly higher than that of the other groups (p<0.05). The leakage values of Wet/primed group showed significantly lower than that of the other groups, but, there was no significant difference between Wet group and Dry group. 4. There was no significantly difference between the dentin adhesives regarding the surface treatments in all groups(p>0.05). 5. On the backscatterd scanning electron microscopy observation, the penetration of the silver ion occured at the bonding resin/dentin interface. In the Wet/primed group, resindentin hybrid zone and resin penetration into the dentin was observed. The resin tags were compactively formed to a thickness of $3\sim4{\mu}m$ at the upper part of dentinal tubules. In the Dry/primed group, the thickness of the hybrid zone and the diameter, depth of the resin tags diminished. In the Non-primed groups, the hybrid zone was not identified and few resin tag was observed. There was the gap formation in the resin/dentin interface.

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A Systematic Review of Cupping Therapy for Insomnia Disorder (불면장애에 대한 부항요법의 체계적 문헌고찰)

  • Jeong-Han Lee;Mi-Ra Choi;Jung-Hwa Lim;Bo-Kyung Kim
    • Journal of Oriental Neuropsychiatry
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    • v.34 no.3
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    • pp.181-212
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    • 2023
  • Objectives: To examine the efficacy and safety of cupping therapy for insomnia disorder and provide clinical evidence that could contribute to further research. Methods: We searched randomized controlled trials (RCTs) that verified effects of cupping therapy for insomnia disorder from 11 domestic and foreign databases. Included studies were evaluated using Risk of Bias (RoB). Results: Nineteen RCTs were selected. Wet cupping was more frequently used than dry cupping. Moving cupping was mostly used among dry cupping methods. Dry cupping was mainly performed in Bladder Meridian on the back. Wet cupping was mainly performed on BL18, LR14, and BL15. The most common treatment period was 4 weeks. The average number of treatments per week was about 2.4 times for all types of cupping, about 3.2 times for dry cupping and about 1.9 times for wet cupping. All selected studies showed a significant sleep improvement compared to the control group. As a result of the meta-analysis, in terms of effective rate, SAS score, and SDS score, the wet cupping in combination with acupuncture was significantly more effective than acupuncture alone, although the quality of selected RCTs was low. Conclusions: Cupping therapy is effective for insomnia disorder. Based on results of this study, it is reasonable to use wet cupping two times per week on BL18, LR14, and BL15 or use moving cupping three times per week in Bladder Meridian on the back for 4 weeks to treat insomnia disorder.

Drilling Characteristics of PVC Materials (PVC 재료의 드릴링 특성)

  • Byun, J.Y.;Park, Na-Ram;Chung, S.W.;Kwon, S.H.;Kwon, S.G.;Park, J.M.;Kim, J.S.;Choi, Won-Sik
    • Journal of the Korean Society of Manufacturing Process Engineers
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    • v.14 no.1
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    • pp.70-77
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    • 2015
  • This paper develops and evaluates a mechanical machining process which involves drilling on PVS material. According to the material, two treatment experiments were conducted, one involving drilling in a wet condition or using a lubricant and one involving drilling in a dry condition with no lubricant. Drilling in a dry condition showed better performance in terms of the cutting time than in the wet condition. Otherwise, the wet condition has several advantages. The lubricant influenced the burr diameter size and minimized the temperature on the surface of the work piece. During the wet condition drilling process, a smaller burr diameter size was noted as compared to the dry condition. The temperature showed a linear correlation with the drill bit size, where a least-square analysis provided an $R^2$valuewhichexceeded 0.95. The wet condition required more cutting time than the dry condition. In this condition, the water provides a lubrication effect. A thin layer between the cutting edges and the surface of the work piece is formed. The chip formation is affected by the drilling depth. The color on the tips of the chips was darker than in the initial condition. No correlation between the drilling depth and the bore roughness was noted, but the variation of the cutting speed or the RPM influenced the roughness of the bore. The optimum cutting speed ranged from 40 RPM to 45 RPM in the condition which provided the finest roughness surface.

Aging Characteristics of Marketing Korean Paper(Hanji) (한국산 시판 한지의 열화 특성)

  • Park, Seong-Cheol;Choi, Mi-Sook;Lim, Hyun-A
    • Journal of Conservation Science
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    • v.25 no.2
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    • pp.161-169
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    • 2009
  • The objective of this study was to investigate stability of Korean Paper(Hanji) which is being sold in the Korean markets according to aging treatment. In order to know the aging characteristics, the optical and mechanical properties of before and after wet and dry-heat aging treatment were examined. The optical and mechanical properties were shown higher reduction in the dry-heat aging treatment compared to the wet-heat aging treatment. The Soonji (pure mulberry Hanji) made from black mulberry bast pulp was shown a great reduction of the brightness and whiteness, and increase of the opacity in the aging treatment. On the other hand, in case of mechanical properties, the breaking length of Soonji made from white mulberry bast pulp was significantly higher than that of the others, and the tensile strength was shown drastic reduction in according to Soonji made from black mulberry bast pulp in the aging treatment. The burst strength of Soonji made from black and white mulberry bast pulp was shown the similar value in the wet-heat aging treatment. The folding endurance of Soonji made from white mulberry bast pulp was significantly higher than that of others before and after aging treatment. Consequently, Hanji was affected sensitive in the temperature compared to the humidity. Meanwhile, the density and color of the chinese ink was no significant changes before and after wet and dry-heat aging treatment.

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Study On the Characteristics of Milled $UO_2$ Powder Prepared by Oxidation and Reduction Process (산화ㆍ환원처리된 $UO_2$ 분말의 분쇄특성 연구)

  • Lee Jae-Won;Lee Jung-Won
    • Resources Recycling
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    • v.11 no.4
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    • pp.3-10
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    • 2002
  • The characteristics of dry and wet milled powder prepared by 1 cycle OREOX (oxidation and reduction of oxide fuels) treatment were investigated using the simulated spent fuel pellet. Sintered pellets simulating spent nuclear fuel burned in reactor were fabricated from $UO_2$ powder using as a starting material in fabrication of nuclear fuel. The 1 cycle OREOX-treated powder was prepared by only one path of oxidation md reduction of the simulated pellet. Powder having average particle size of less than 1 $\mu\textrm{m}$ could be easily obtained by dry milling, but not be achieved by wet milling. And, specific surface area of dry milled pow-der was higher than that of wet milled powder. Dry milled powder formed loose agglomerate, while wet milled powder showed the shape of irregular and angular particles. Dry milled powder provided higher green density, resulting in higher sintered density of higher than 95% TD and average grain size of larger than 8 $\mu\textrm{m}$ satisfying the standard specification of sintered pellets.

Effects of steam heat treatment conditions on the swelling and physical properties of PBS (polybutylene succinate) copolymer monofilament gill net (습식 열처리 조건이 PBS 공중합체 모노필라멘트 그물감의 부풀음 및 물성변화에 미치는 영향)

  • Park, Seongwook;Kim, Seonghun;Do, Choonho;Lim, Jihyun;Choi, Haesun
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.50 no.3
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    • pp.274-283
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    • 2014
  • Swelling of the heat-treated netting for gillnet was estimated through the netting height in square acrylic tank. Experimental Nylon netting and PBSAT netting were heat-treated by using the high-degree vacuum method in hot water after net making. Heat-treatment temperatures were conducted with Nylon netting $105^{\circ}C$ and PBSAT netting $62^{\circ}C$, $65^{\circ}C$, $66^{\circ}C$, $67^{\circ}C$. The swelling measurement method of a netting using the square tank was capable of the reduction measurement errors comparing with measurement methods of a mesh inner angle and the shortening rate of a mesh size. In addition, this method was available to comparison evaluation for each netting more easily. Wet type heat-treatment apparatus with high-degree vacuum was shown higher $7{\sim}8^{\circ}C$ inner side temperature than a setting temperature. The tensile strength and elongation of Nylon netting and PBSAT netting were shown higher wet condition than dry condition. The tensile strengths of PBSAT monofilaments in dry and wet condition were sharply decreased at heat-treatment temp. $75^{\circ}C$ than heat-treatment temp. $74^{\circ}C$.

Physical Properties of Aramid and Aramid/Nylon Hybrid ATY for Protective Garments according to the Dry and Wet Texturing Conditions (건·습 텍스쳐링 가공조건이 방호의류용 Aramid ATY와 Aramid/Nylon hybrid 사의 물성에 미치는 영향)

  • Park, Mi Ra;Kim, Hyun Ah;Kim, Seung Jin
    • Fashion & Textile Research Journal
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    • v.15 no.3
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    • pp.444-451
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    • 2013
  • This paper surveys the physical properties of aramid and aramid/nylon hybrid air-jet textured yarns(ATY) for protective garments according to wet and dry texturing conditions. Aramid and nylon filaments were used to make two kinds of para-aramid ATY and four kinds of aramid/nylon hybrid ATY with dry and wet treatments. The analyzed physical properties of six specimens (made on the ATY machine) are as follows. The tenacity and initial modulus of aramid and aramid/nylon hybrid ATY decreased with the wetting and breaking strain; however, the yarn linear density of aramid and hybrid ATY increased with wetting treatment. The dry and wet thermal shrinkage of the hybrid ATY increased with wetting. The stability of aramid and hybrid ATY also increased with wetting. The physical properties of core/effect type hybrid ATY showed significantly more change than the core type hybrid ATY and the physical properties of nylon/aramid core/effect hybrid ATY showed significantly more change than the of aramid/nylon core/effect hybrid ATY. A higher bulky and breaking strain of hybrid ATY require ATY processing conditions of nylon on the core part with wetting and aramid on the effect part. ATY processing conditions for nylon and aramid on the core part with wetting are required for a higher tenacity and modulus. ATY processing conditions of nylon and aramid on the core with no wetting are required for a low thermal shrinkage.

EFFECTS OF DENTIN SURFACE WETNESS OR DESICCATION AFTER ACID ETCHING ON DENTIN BONDING (산부식후 상아질 표면의 습윤 또는 건조가 상아질 결합에 미치는 영향)

  • Yang, Won-Kyung;Kwon, Hyuk-Choon;Son, Ho-Hyun
    • Restorative Dentistry and Endodontics
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    • v.25 no.2
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    • pp.243-253
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    • 2000
  • The purpose of this in vitro study was to evaluate dentin bonding by two different dentin bonding systems(DBS) using acetone based primer or adhesive [All Bond 2(AB2), One Step(OS)] when they were applied by wet or dry bonding technique. Morphology of resin-dentin interface and hybrid layer thickness(HLT) were investigated using Confocal Laser Scanning Microscope(CLSM) and compared to shear bond strength(SBS). 72 extracted sound human molars were randomly divided into 4 groups of 18 teeth each - Group 1.(AW); AB2 by wet bonding. Group 2(AD); AB2 by dry bonding. Group 3.(OW); OS by wet bonding, Group 4.(OD); OS by dry bonding. In 6 teeth of each group, notch-shaped class V cavities(depth 2mm) were prepared on buccal and lingual surface at the cementoenamel juction(12 cavities per group). To obtain color contrast in CLSM observation, bonding resins of each DBS were mixed with rhodamine B and primer of AB2 was mixed with sodium fluorescein. Prepared teeth of each group were treated with AB2, OS, respectively according to the manufacturer's instructions except for dentin surface moisture treatment after acid etching. In group 1 and 3, after acid etching, excess water was removed with wet tissue(Kimwipes), leaving consistently shiny, visibly hydrated dentin surface. In group 2 and 4, dentin surface was dried for 10 seconds at 1 inch distance. The treated teeth were then packed with composite resin(${\AE}$litefil) and light-cured. 12 microscopic samples($60{\sim}80{\mu}m$ thickness) of each group were obtained after longitudinal section and grinding(Exakt cutting and grinding system). Morphological investigation of resin-dentin interface and HLT measurement using CLSM were done. For measurement of SBS, remaining 12 teeth of each group were flattened occlusally to remove all enamel and grinded to 500 grit SiC(Pedemet Specimen Preparation Equipment). After applying DBS on the exposed dentin surface, composite resin was applied in the shape of cylinder, which has 5mm diameter, 1.5mm thickness, and light cured. SBS was measured using Instron with a crosshead speed of 0.5mm/min. It was concluded as follows, 1. HLT of AW(mean: $2.59{\mu}m$) was thicker than any other group, and followed by AD, OW, OD in descending order(mean; 2.37, 2.28, $1.92{\mu}m$). Only OD had statistically significant differences(p<0.05) to AW and AD. 2. There were intimate contact of resin and dentin at the interface in wet bonding groups, but gaps or irregular interfaces were observed in dry bonding groups. 3. The length, diameter, density of resin tags were various even in the same group without significant differences between groups and lots of adhesive lateral branches were observed. 4. There were no statistically significant difference of SBS between AB2 and OS, but SBS of wet bonding groups were significantly higher(p<0.05) than dry bonding groups. 5. There were no consistent relationships between HLT and SBS.

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