• Title/Summary/Keyword: Swelling effect

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Preparation and Properties of Bio-inspired Waterborne Polyurethanes Containing Different Amount of Paraffin Wax

  • Kim, Hye-Lin;Kim, Ae-Li;Lee, Young-Hee;Kim, Sung Yeol;Park, Cha-Cheol;Rahman, Mohammad Mizanur;Kim, Han-Do
    • Textile Coloration and Finishing
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    • v.30 no.1
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    • pp.9-19
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    • 2018
  • To prepare bio-inspired antifouling coating materials having similar structure with lotus, self-crosslinkable waterborne polyurethanes emulsions containing paraffin wax (CWPU/P0, 0.25, 0.5, 1.0, 1.5, 2.0, the number indicated the wt% of wax) were prepared by an emulsifier-free/solvent free prepolymer mixing process. The as-polymerized CWPU/P emulsions containing 0 - 1.00wt% of paraffin wax were found to be stable after 4 months, however, CWPU/P emulsions containing 1.50 and 2.00wt% of paraffin wax were unstable within 1 month storage. Considering the stability of emulsions, the optimum paraffin wax content was found to be about 1wt% to obtain stable antifouling coating emulsion material. The surface topology of CWPU/P film samples was characterized by atomic force microscopy (AFM). This study examined the effect of paraffin wax content on the surface roughness, water contact angle/surface energy, water swelling, light transmittance and tensile properties of CWPU/P film samples.

Assessing the Systemic Toxicity in Rabbits after Sub Acute Exposure to Ocular Irritant Chemicals

  • Reshma, Cherian Sebastian;Sruthi, Sudhakaran;Syama, Santhakumar;Gayathri, Vishwanath;Mohanan, Parayanthala Valappil
    • Toxicological Research
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    • v.31 no.1
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    • pp.49-59
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    • 2015
  • Eye is a highly vascularised organ. There are chances that a foreign substance can enter the systemic circulation through the eye and cause oxidative stress and evoke immune response. Here the eyes of rabbits were exposed, for a period of 7 days, to 5 known ocular irritants: Cetyl pyridinium chloride (CPC), sodium salicylate (SS), imidazole (IMI), acetaminophen (ACT) and nicotinamide (NIC). The eyes were scored according to the draize scoring. Blood collected from the treated rabbit were analyzed for haematological and biochemical parameters. After sacrifice, histological analysis of the eye and analysis of pro-inflammatory biomarkers ($IL-1{\alpha}$, $IL-1{\beta}$, IL-8 and $TNF-{\alpha}$) in the cornea using ELISA was carried out. Spleen was collected and the proliferation capacities of spleenocytes were analyzed. Liver and brain were collected and assessed for oxidative stress. The eye irritation potential of the chemicals was evident from the redness and swelling of the conjunctiva and cornea. Histopathological analysis and ELISA assay showed signs of inflammation in the eye. However, the haematological and biochemical parameters showed no change. Spleenocyte proliferations showed only slight alterations which were not significant. Also oxidative stress in the brain and liver were negligible. In conclusion, chemicals which cause ocular irritation and inflammation did not show any systemic side-effects in the present scenario.

Effects of Process Variables and MAPP Coupling Agent on Properties of Wood Fiber-Polypropylene Fiber Composite by Turbulent Air Mixing (공정변수(工程變數)와 MAPP 결합제(結合劑)가 난기류(亂氣流) 혼합방식(混合方式)에 의하여 제조(製造)된 목섬유(木纖維)-폴리프로필렌섬유(纖維) 복합재(複合材)의 성질(性質)에 미치는 영향(影響))

  • Yoon, Hyoung-Un;Park, Jong-Young
    • Journal of the Korean Wood Science and Technology
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    • v.26 no.1
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    • pp.76-86
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    • 1998
  • Effects of processing variables and MAPP (maleic anhydride polypropylene) coupling agent on the properties of composite were discussed for turbulent-air-mixed woodfiber-polypropylenefiber composites. In this research, density, composition ratio, and mat moisture content were established as processing variables, and emulsified MAPP prepared by direct pressure method was incorporated as the coupling agent. And the turbulent air mixer, which was improved in function through alteration of our previous fiber mixer, was used to mix wood fibers and polypropylene fibers. At the addition level of 1% MAPP, based on oven-dried wood fiber weight, woodfiber-polypropylenefiber composites generally showed enhanced the physical and mechanical properties. And composites with low to medium densities of 0.6 to 0.8g/$cm^3$ greatly increased in these property values than with high densities of 1.0g/$cm^3$ or more by adding 1 % MAPP. Thus, MAPP addition was thought to be an effective way of enhancing properties for nonwoven web composites. At the mat moisture contents of 5 to 20%, however, the physical and mechanical properties were not enhanced by adding 1% MAPP. In the composites containing 15% polypropylene fibers, the lowest thickness swelling and water absorption values were observed at the 1% MAPP level. The addition of more than 1% MAPP had the adverse effect on the physical and mechanical properties of composites.

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Effect of Mixing Ratio of White and Germinated Brown Rice on the Physicochemical Properties of Extruded Rice Flours (백미와 발아현미의 혼합비율이 압출성형 멥쌀가루의 이화학적 특성에 미치는 효과)

  • Kim, Ji Myoung;Yu, Mengying;Shin, Malshick
    • Korean journal of food and cookery science
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    • v.28 no.6
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    • pp.813-820
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    • 2012
  • To develop the high quality gluten-free rice products with health functionality and desirable texture with moistness, the physicochemical properties of extruded rice flours prepared from the mixture of germinated brown and white rices were investigated. The domestic organic Samgwangbyeo was used to make white and germinated brown rices. White rice (WR) was dried after soaked for 6 h at $15{\pm}3^{\circ}C$ and mixed with germinated brown rice (GBR) with different mixing ratios (100:0, 75:25, 50:50, 25:75, 0:100). The operating conditions of twin screw extruder were 250 rpm of screw speed, $120^{\circ}C$ of barrel temperature, and 25% moisture content of rice flour. The ash, crude protein and crude lipid contents were significantly different (p<0.05) and those of extruded GBR were the highest values, but those of extruded WR were the lowest. The color difference of extruded WR based on white plate showed the lowest among them. The water binding capacity (334.16%), swelling power (8.83 g/g), solubility (33.13%), and total starch (79.50%) were the lowest in extruded GBR. The viscosities of all extruded rice flours by RVA were maintained during heating. The peak and total setback viscosities of extruded rice flours ranged 127-352 and 58.0-85.5 cP, respectively. The novel food biomaterial from germinated brown rice as well as white rice was developed by twin screw extruder. The extruded rice flours control the moistness to improve the texture and also have functional materials, dietary fiber, GABA, and ferulic acid, etc to increase quality of gluten free rice products.

Comparison of Piroxicam Pharmacokinetics and Anti-Inflammatory Effect in Rats after Intra-Articular and Intramuscular Administration

  • Park, Chan Woong;Ma, Kyung Wan;Jang, Sun Woo;Son, Miwon;Kang, Myung Joo
    • Biomolecules & Therapeutics
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    • v.22 no.3
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    • pp.260-266
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    • 2014
  • This study evaluated the pharmacokinetic profile and therapeutic efficacy of piroxicam (PX), a long acting non-steroidal anti-inflammatory drug for the treatment of arthritis, following intra-articular (IA) injection in comparison to the pharmacokinetic profile and therapeutic efficacy of PX after intramuscular (IM) injection. In the pharmacokinetic study in rats, systemic exposure and pharmacokinetic parameters of PX after a single IA dose were compared with systemic exposure and pharmacokinetic parameters of PX after administration of the same dose IM (0.6 mg/kg). The anti-inflammatory and analgesic effects of IA PX were evaluated simultaneously in a monoiodoacetate-induced osteoarthritis rat model. The plasma PX concentration rapidly rose following IA injection, and it was comparable to the plasma PX concentration following IM injection, suggesting the rapid efflux of the drug molecule from the joint cavity. However, in the efficacy study, the IA PX administration significantly reduced the knee swelling by reducing the level of prostaglandin $E_2$ in the joint, compared to that following administration of IA vehicle and after administration of the IM PX dose. In addition, we found that the anti-inflammatory and anti-nociceptive efficacies of IA PX were synergistically increased upon co-treatment with hyaluronic acid (HA), a potent agent for the treatment of osteoarthritis, at the weight ratio of 1:1 or 1:2, and these effects were more pronounced than those following administration of HA or PX alone. In conclusion, this study demonstrated the efficacy of the IA use of PX alone and/or in combination with HA in osteoarthritis.

Effects of Pulp Pre-treatment and Grinder Clearance on the Manufacturing Characteristics of Microfibrillated Cellulose (펄프의 전처리 및 그라인더 간격이 MFC 제조 특성에 미치는 영향)

  • Yong, Seong Moon;Kwak, Gun Ho;Cho, Byoung-Uk;Lee, Yong Kyu;Won, Jong Myoung
    • Journal of Korea Technical Association of The Pulp and Paper Industry
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    • v.47 no.2
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    • pp.61-69
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    • 2015
  • A number of researches have been carried out regarding the utilization of nanocellulose(crystalline nanocellulose, microfibrillated cellulose, nanofibrillated cellulose) for the manufacture of various kinds of composites and functional products. However, only few research works on the manufacturing characteristics of nanocellulose could be found, although some companies started already the production of nanocellulose in commercial scale. However, the most important thing in commercializing of production and utilization of nanocellulose is to develop the economical and efficient process. Thus, this study was carried out in order to investigate the effects of refining, alkaline pre-treatment and grinder clearance on the characteristics of microfibrillated cellulose and energy consumption. There was no significant differences in crystalline index with the degree of microfibrillation. The initial fibrillation could be improved by refining pre-treatment, but its effect was not observed anymore since the fibrillation was done up to certain level by grinding. Refining pre-treatment did not improved the energy efficiency. Alkaline pre-treatment can be helpful because the swelling of pulp fiber will facilitate fibrillation. It was found that the decrease in grinder clearance was helpful to improve the energy efficiency.

Studies on the Farrowing Induction of Sow with Prostaglandin $F_2\alpha$ I. Effect of Administration Method on the Farrowing Induclion (Prostaglandin $F_2\alpha$의 투여에 의한 돼지의 분만유기에 관한 연구 I. 투여방법이 분만유기에 미치는 영향)

  • 정길생;연정웅
    • Korean Journal of Animal Reproduction
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    • v.3 no.2
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    • pp.42-49
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    • 1979
  • This experiment was carried out to clarify the practical use of farrowing induction with PGF2$\alpha$ in swine production. Total 320 heads of pregnant sow were used and the effects of administration time, dosage, administration method of PGF2$\alpha$ and parity of sow on the farrowing induction were investigated. The results obtained in this experiment were summarized as following: 1. Total 228 heads out of 240 head which were treated with PGF2$\alpha$ in order to farrow artificially were farrowed normally. the rate of farrowing induction was 95%. 2. Several farrowing symptoms such as restlessness, bloody eye, udder swelling, milk discharge and nest building for piglets were observed in a few minutes after administration of PGF2$\alpha$. 3. Artifical parturition of sow treated with PGF2 at the 113rd, 112nd, 111st, 110th and 109th day of pregnancy were induced 17.0$\pm$7.3, 24.2$\pm$7.0, 31.3$\pm$14.7, 43.0$\pm$12.2 and 62.2$\pm$15.7 hours after administration, and the duration of pregnancy was significantly (P<0.01) shortened by PGF2$\alpha$ anministration. 4. Minimum amount of PGF2$\alpha$ per head for effective farrowing inductin was considered to be more than 5mg, and the more the amount, the shorter time needed for farrowing induction was resulted. 5. Effective farrowing induction was obtained from the sow treated with PGF2$\alpha$ via vulvomucous rather than from the sow treated via intromuscular, and intervals from PGF2$\alpha$ administration to farrowing in 4th-6th farrowed sows were shorter than those of 1st-3rd farrowed sows but no significant difference was observed.

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Developement of Bamboo Strand Board Made from 3 Months Old Domesitic Bamboo Species (3개월생 국산 대나무를 이용한 대나무 스트랜드보드 개발)

  • 이화형;강석구;김관의
    • Journal of the Korea Furniture Society
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    • v.11 no.2
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    • pp.45-53
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    • 2000
  • This study was carried out to determine the suitability of 3 months old bamboo species of Phyllostachys bambusoides S. et Z., Phyllostachys Pubescens Mazel and Phyllostachys nigra var henonis Stapf as raw materials for the manufacture of strandboard. Total of 108 strandboards were made using urea-formaldehyde resin content level of 12% and one percent of liquid wax emulsion. The strandboard consisted of three layers the top and the bottom layer of which were oriented to the same direction and weighted 25% of the strandboard each. The middle core layer weighed 50% of the board and was perpendicular to the outer top and bottom layers. Analysis was performed to determine the effect of strand lengths and Uowing years of 3 months, 2 years and 3 years on strandboard properties. The physical and mechanical properties of bamboo species and boards were measured and compared to the standard requirements of strandboards. The results are as follows; 1. The more the growing years the higher the density of bamboo. Top part of bamboo indicated higher density value than that of bottom part. 2. Bamboo showed higher static bending strength compared to the main wood species. Longer growing years of bamboo generally inclosed the static tending strength out there were no statistical significancies for Phyllostachys bmbusoides S. et Z. and Phyllostachys pubescens Mazel. 3. Strand length indicated no difference on density and moisture content of strandboard. 5 cm of strand length gave the best static bending strength and internal bonding strength. Bamboo strandboard exhibited lesser extents of thickness swelling than that of CSA standard. 4. 3 months old bamboo gave higher static bending strength of strandboard than those of 2 years and 3 years old bamboo. In case of Phyllostachys nigra var henonis Stapf, 3 months old bamboo indicated higher internal bonding strength than those of 2 years and 3years old bamboo. but in Phyllostachys bambusoides S. et Z., Phyllostachys pubescens Mazel, there were no difference among growing years. Growing years showed no different physical properties of bamboo strandboard.

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Physicochemical Properties of Freeze-dried Corn Starch Sponge Matrix (동결 건조된 옥수수 전분 스펀지 매트릭스의 이화학적 특성)

  • Han, Kyung-Hoon;Kim, Doh-Hee;Song, Kwan-Yong;Lee, Kye-Heui;Yoon, Taek-Joon;Yang, Sung-Bum;Lee, Seog-Won
    • The Korean Journal of Food And Nutrition
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    • v.23 no.3
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    • pp.419-427
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    • 2010
  • The focus of the current study was to investigate the physicochemical properties of a corn starch-sponge matrix prepared at a low concentration below gel forming by freeze-drying. The effect of variables(starch concentration, heating temperature, and heating hold time) on the physicochemical properties of the samples was analyzed by response-surface methodology. Regression models on the properties of samples such as hardness, springiness, and water solubility index(WSI) showed high correlation coefficients(r>0.95) and significant F values, but regression models for the other properties(swelling power, apparent viscosity, reducing sugar content, and digestibility) showed them to have relatively low significance. Sample hardness of sample showed the highest value at condition of $90^{\circ}C$ and 5%, whereas springiness was at a maximum at $130^{\circ}C$ and 5%. Also, at 1% of starch concentration, mechanical properties were greatly decreased as the relative humidity increased, compared with the 3% and 5%, especially in the hardness of samples. The WSI showed an increasing trend with heating temperature regardless of starch concentration. Overall, the physicochemical properties of freeze-dried corn starch-sponge matrix were influenced much more by starch concentration and heating temperature than by heating hold time. The results of this study show that the basic properties of freeze-dried corn starch-sponge matrix can be used for the specific food applications or as a functional material for its stability.

Effect of soaking time of rice and particle size of rice flours on the properties of nonwaxy rice flours soaking at room temperature (수침시간과 입자크기가 상온에서 수침한 멥쌀가루에 미치는 영향)

  • 신말식;김정옥;이미경
    • Korean journal of food and cookery science
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    • v.17 no.4
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    • pp.309-315
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    • 2001
  • The effects of soaking time of nonwaxy rice and particle size of rice flour on the properties of nonwaxy rice flour after steeping at room temperature were investigated. Nonwaxy rice was soaked at 20$^{\circ}C$ for 0, 1, 12, or 24hr, dried at room temperature and milled. Nonwaxy rice flours were passed through 45 mesh or 100 mesh sieve, and were compared for the properties depending on the particle size and soaking time. The particles of rice flour were separated into 10$\mu\textrm{m}$∼30$\mu\textrm{m}$ and 40$\mu\textrm{m}$∼80$\mu\textrm{m}$ groups, and the amount of large particle size(40$\mu\textrm{m}$∼80$\mu\textrm{m}$) was greater in the flour sieved through 45 mesh than 100 mesh sieve. The protein and ash contents decreased and amylose contents increased as the soaking time increased. The water-binding capacity increased rapidly up to 1 hr of soaking and increased slowly thereafter. The swelling power and the solubility increased with temperature rising in the range of 65$^{\circ}C$∼95$^{\circ}C$, and these two properties increased rapidly up to 12 hr of soaking. Peak viscosity and breakdown of the pastes prepared with 12 hr-soaked nonwaxy rice flour were higher than those with 1 hr-soaked ones, while the setback and viscosity at 95$^{\circ}C$ of 12 hr-soaked ones were lower than 1hr-soaked ones.

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