• Title/Summary/Keyword: Process of Moisture Absorption

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Effects of Nano-silica/Nano-alumina on Mechanical and Physical Properties of Polyurethane Composites and Coatings

  • Swain, Sarojini;Sharma, Ram Avatar;Bhattacharya, Subhendu;Chaudhary, Lokesh
    • Transactions on Electrical and Electronic Materials
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    • v.14 no.1
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    • pp.1-8
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    • 2013
  • The present approach shows the use of nano-silica/nano-alumina in polyurethane (PU) matrix, which lead to significant improvements in the mechanical and thermal properties of the nano-composite. It is observed that with incorporation of 1% of nano-alumina into the PU matrix, there is an improvement in the tensile strength of around 50%, and for nano-silica the improvement is around 41%, at the same concentration. The morphological data shows that above 3% of the nano particles there are agglomerations in the nanocomposite. Again with the absorption of moisture, there is a decrease in the thermal and mechanical properties of the PU resin, but in this research work it is observed that with the incorporation of the nano particles, in the presence of absorbed moisture there is an improvement in mechanical and thermal properties of the composite, over that of the PU matrix.

Kinetic Study for Hygroscopic Behavior of Freeze Dried Soy Paste Powder (동결건조 분말된장의 흡습 거동에 대한 속도론적 연구)

  • Hwang, Eung-Soo;Lee, Chul-Won;Yu, Ju-Hyun;Lee, Shin-Young
    • Korean Journal of Food Science and Technology
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    • v.19 no.3
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    • pp.231-238
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    • 1987
  • Two kinds of soy pastes with different colors (reddish brown and yellowish white) were dehydrated by freeze drying in powder form. Hygroscopic behaviors of powdered soy pastes were investigated under the conditions of various water acitivities (0.11-0.88) and three different temperatures (25,40 and $50^{\circ}C$), and presented a kinetic and thermodynamic interpretatons in the view point of qualities and storage stability. Moisture absorption isotherms of powdered soy pastes were of type II according with BET classification and can be described by the Henderson's empirical equation. The safe storage moisture levels calculated by the Laurie's equation were ranging from 5.5 to 3.98% dry basis with oaring temperatures. The moisture absorption process for powdered soy paste followed the Ist order kinetic in the difference of equilibrium moisture content and arbitrary moisture content and the initial step was characterized by very fast absorption of moisture. The change of, dispersion capacity and color difference for powdered soy paste were extremely dependent upon water activity under the storage and the maximum stability was found at safe storage moisture levels. Also, the variation of thermodynamic parameters with moisture content was significant at safe storage moisture content levels and suggested d the considerable correspondence to storage stability of powdered soy paste.

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Characteristics of Low Dielectric Constant SiOF Thin Films with Post Plasma Treatment Time (플라즈마 후처리 시간에 따른 저유전율 SiOF 박막의 특성)

  • 이석형;박종완
    • Journal of the Korean Vacuum Society
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    • v.7 no.3
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    • pp.167-272
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    • 1998
  • The fluorine doped silicon oxide (SiOF) intermetal dielectric (IMD) films havc been of interest due to their lower dielectric constant and compatibility with existing process tools. However, instability issues related to hond and increasing dielectric constant due to water absorption when the SiOF film was exposured to atmospheric ambient. Therefore, the purpose nf this research is to study the effect of post oxygen plasma treatment on the resistance of nioisture absorption and reliability of SiOF film. Improvement of moisture ahsorption resistance of SiOF film is due to the forming of thin $SiO_2$ layer at the SiOF film surface. It is thought that the main effect of the improvement of moisture absorption resistance was densification of the top layer and reduction in the numher of Si-F honds that tend to associate with OH honds. However, the dielectric constant was inucased when plasma treatment time is above 5 min. In this study, therefore, it is thought that the proper plasma treatment time is 3 min when plasma treatment condition is 700 W of microwave power, 3 mTorr of process pressure and $300^{\circ}C$ of substrate temperature.

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Effects of Extrusion Conditions on the Physicochemical Properties of Extruded Red Ginseng

  • Gui, Ying;Gil, Sun-Kuk;Ryu, Gi-Hyung
    • Preventive Nutrition and Food Science
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    • v.17 no.3
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    • pp.203-209
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    • 2012
  • The effects of variable moisture content, screw speed and barrel temperature on the physicochemical properties of red ginseng powder extrudates were investigated. The raw red ginseng powders were processed in a co-rotating intermeshing twin-screw extruder. Primary extrusion variables were feed moisture content (20 and 30%), screw speed (200 and 250 rpm) and barrel temperature (115 and $130^{\circ}C$). Extruded red ginseng showed higher crude saponin contents (6.72~7.18%) than raw red ginseng (5.50%). Tested extrusion conditions did not significantly affect the crude saponin content of extrudates. Increased feed moisture content resulted in increased bulk density, specific length, water absorption index (WAI), breaking strength, elastic modulus and crude protein content and decreased water solubility index (WSI) and expansion (p<0.05). Increased barrel temperature resulted in increased total sugar content, but decreased reducing sugar content in the extrudate (p<0.05). Furthermore, increased barrel temperature resulted in increased amino acid content and specific length and decreased expansion and bulk density of extrudates only at a higher feed moisture content. The physicochemical properties of extrudates were mainly dependent on the feed moisture content and barrel temperature, whereas the screw speed showed a lesser effect. These results will be used to help define optimized process conditions for controlling and predicting qualities and characteristics of extruded red ginseng.

Studies on the new manufacturing process and physical, mechanical properties of barkboard (수피(樹皮)보드의 새로운 제조방법(製造方法)과 그 물리기계적(物理機械的) 성질(性質)에 관(關)한 연구(硏究))

  • Lee, Hwa-Hyoung
    • Journal of the Korean Wood Science and Technology
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    • v.17 no.4
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    • pp.26-34
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    • 1989
  • This study was carried out to manufacture bark board from oak bark by new processes and to examine the physical and mechanical properties of the board. This process with no addition of adhesive used higher pressure and temperature than the conventional one and was applied with or without paraformaldehyde. The results are as follows: 1. The new manufacturing process allowed a good bark board with high absorption coefficient. 2. The best manufacturing process for the mechanical properties of bark board was paraformaldehyde 10%-$250^{\circ}C$-100kg/$cm^2$-3 minutes, (bending strength 40kg/$cm^2$, internal bonding strength 2kg/$cm^2$) and the best manufacturing process for both the mechanical properties of bark board and economic point of view was $250^{\circ}C$-100kg/$cm^2$-3 minutes (bending strength 28kg/$cm^2$, internal bonding strength 1.52kg/$cm^2$). 3. Bark board showed specific gravities from 0.94 to 1.03 and air dried moisture content 9.2% to 11.7%, but Bark board needed paraffin wax emusion treatment. 4. The absorption coefficient of bark boards had two peaks along with frequency; one in 200-400 cps, the other 1200-2000 cps. The former was low but the latter great.

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Characteristics of Low Dielectric Constant SiOF Thin Films with Post Plasma Treatment Time (플라즈마 후처리 시간에 따른 저유전율 SiOF 박막의 특성)

  • Lee, Seok Hyeong;Park, Jong Wan
    • Journal of the Korean Vacuum Society
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    • v.7 no.3
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    • pp.267-267
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    • 1998
  • The fluorine doped silicon oxide (SiOF) intermetal dielectric (IMD) films have been of interest due to their lower dielectric constant and compatibility with existing process tools. However instability issues related to bond and increasing dielectric constant to water absorption when the SiOF films was exposured to atmospheric ambient. Therefore, the purpose of this research is to study the effect of post oxygen plasma treatment on the resistance of moisture absorption and reliability of SiOF film. Improvement of moisture absorption resistance of SiOF film is due to the forming of thin SiO₂layer at the SiOF film surface. It is thought that the main effect of the improvement of moisture absorption resistance was densification of the top layer and reduction in the number of Si-F bonds that tend to associate with OH bonds. However, the dielectric constant was increased when plasma treatment time is above 5 min. In this study, therefore, it is thought that the proper plasma treatment time is 3 min when plasma treatment condition is 700 W of microwave power, 3 mTorr of process pressure and 300℃ of substrate temperature.

고감성 의류용 수분감응형 인텔리전트 소재의 물성

  • Kim, Hyun-Ah;Woo, Ji-Woon
    • Science of Emotion and Sensibility
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    • v.17 no.1
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    • pp.93-104
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    • 2014
  • This paper investigates the physical properties such as water absorption, drying and hygral expansion of moisture responded transformable fibers and their knitted fabrics including dyeing characteristics according to the different dyeing time and temperature. For this purpose, three kinds of covered filament yarn specimens using HEF and spandex as core and PET, aerocool as a covering filament were prepared. The knitted fabric specimens were made using three kinds yarn specimens and dyed with different dyeing temperature and time. The moisture absorption, drying and hygral expansion of three kinds of knitted fabric specimens were measured and discussed with yarn structure. The wearing performance of these knitted fabric specimens were also measured and discussed with yarn characteristics using FAST system. Finally, the dyeing characteristics such as dye affinity, color difference and color fastness to washing of these knitted fabric specimens were measured and discussed with different dyeing temperature and time for examining dyeing process performance of these moisture responded transformable knitted fabrics.

Fabrication and Characterization of Hydrogen Getter Based on Palladium Oxide Doped Nanoporous SiO2/Si Substrate (PdOx가 도핑된 나노 기공구조 SiO2/Si 기반의 수소 게터 제작 및 특성평가)

  • Eom, Nu Si A;Lim, Hyo Ryoung;Choi, Yo-Min;Jeong, Young-Hun;Cho, Jeong-Ho;Choa, Yong-Ho
    • Korean Journal of Materials Research
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    • v.24 no.11
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    • pp.573-577
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    • 2014
  • The existing metal getters are invariably covered with thin oxide layers in air and the native oxide layer must be dissolved into the getter materials for activation. However, high temperature is needed for the activation, which leads to unavoidable deleterious effects on the devices. Therefore, to improve the device efficiency and gas-adsorption properties of the device, it is essential to synthesize the getter with a method that does not require a thermal activation temperature. In this study, getter material was synthesized using palladium oxide (PdOx) which can adsorb $H_2$ gas. To enhance the efficiency of the hydrogen and moisture absorption, a porous layer with a large specific area was fabricated by an etching process and used as supporting substrates. It was confirmed that the moisture-absorption performance of the $SiO_2/Si$ was characterized by water vapor volume with relative humidity. The gas-adsorption properties occurred in the absence of the activation process.

The effect of temperatures on the absorption of creosote solution by wood (처리온도(處理溫度)가 크레오소오트 약액(藥液)의 목재내(木材內) 흡수(吸收)에 미치는 영향(影響))

  • Lee, Phil Woo
    • Journal of Korean Society of Forest Science
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    • v.5 no.1
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    • pp.16-21
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    • 1966
  • This experiment was accomplished to study the effect affecting to the absorption of creosote solutions by treating temperatures 20, 50 and $80^{\circ}C$ when the small test pieces were treated as short timed immersion process. The test speciemens used in this experiment were cut into 180 pieces of $2.5{\times}2.5{\times}5cm$ size from the air dried sapwood of Righda Pine (Pinus rigida M.). They were controlled to about 8 to 9% moisture contents and measured specific gravities. Four creosote solutions of $S_1$(straight creosote), $S_2$(creosote 70% : heavy oil 30%), $S_3$(creosote 50% : heavy oil 50%) and $S_4$(creosote 30% : heavy oil 70%), and three treating temperatures of $T_1$($20^{\circ}C$), $T_2$($50^{\circ}C$) and $T_3$($80^{\circ}C$) were applied by factorial split plot design in the each treatment of 3, 7, 15, 30 and 60 minutes immersion. According to the results this study may be concluded briefly as follows : 1. In this immersion process the absorption effects of creosote mixtures by the increase of temperatures are recognized considerably in the each treating times. However in the straight creosote of treated solutions the effective differences were not shown but most effective differences were shown in the $S_2$ solution. 2. Although the solutional absorptions were raised considerably by temperature increase in every treating times the absorption effects of creosote mixtures were not reached to that of straight creosote because the effects are considerably lowered if the treating solutions were mixed with heavy oil even a small quantities. 3. The relations between the creosote contents of treating solutions and the absorptions in wood are shown as Fig. 1, 2, 3, 4 and 5. In these figures the absorption curves made by higher temperature treatment $T_3$ are on the lower treatments $T_1$ and $T_2$ if the solutions were mixed with heavy oil. 4. This report is a part of the consolidated results announced at the annual meetings of Korean Forestry Association in 1964 and 1965.

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A Study on Toluene Removal of VOC and Characteristics of Material Using Biofilter (Bio필터를 이용한 VOC 가스 중 Toluene 제거율과 필터특성 연구)

  • 강신묵;하상안
    • Journal of environmental and Sanitary engineering
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    • v.13 no.2
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    • pp.88-94
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    • 1998
  • This study was investigated the application of biofiltration using cometabolic process to remediate gaseous toluene that are highly recalcitrant to adsorption, absorption and biodegradation. The investigation was conducted using specially built steel columns packed with granular activated carbon for removal of toluene and G.A.C was also coated with Pseudomonas putida microorganisms by addition of KH$_{2}$PO$_{4}$. The biofilter unit was operated in the condition of dry and 27.5% moisture content at gas loading rate of 12.5 l/min. Gaseous toluene taken from tedlar bag was analyzed by the use of G.C. equipped with F.I.D. detector. The removal efficiency of gaseous toluene was 85% at average inlet concentration of 970 ppm during dry operating condition. For gaseous toluene, 91% removal efficient was obtained at the filter material with moisture content and 97% removal efficiency was obtained with Pseudomonas putida microorganisms at gas loading rate of 12.5 l/min.

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