• Journal of Chest Surgery
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• v.33 no.7
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• pp.541-546
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• 2000

Background; Pericardial adhesion poses a major problem during re-operative cardiac surgery. The purpose of this study was to determine the effect of sodium carboxymethol cellulose on experimental pericardial adhesions. Material and Method; Twenty-four rabbits were divided into 2 groups of 12 rabbits each and pericardial mesothelial injury was induced by abrasion. Group A included rabbits receiving intrapericardial injection of Ringer's solution, and Group B included rabbits receiving intrapericardial injection of 3% sodium carboxymethoyl cellulose solution. Three weeks after the surgery, the incidence of adhesions in Group A was compared with that in Group B. Result; Pericardial adhesions were evaluated by tenacity and type scores. Tenacity scores of 3 or greater were considered clinically significant adhesion. Pericardial adhesion was found in 100% of rabbits in group A. However 25% of the rabbits in Group B had pericardial adhesions(p<0.0001). Type scores were also considered clinically significant between 2 groups. Conclusion; Our findings demonstrated that intrapericardial injection of 3% sodium carboxymethyl cellulose solution reduced the incidence of pericardial adhesions in an animal models.

• Macromolecular Research
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• v.17 no.6
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• pp.378-387
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• 2009

This research compared three methods for producing and processing nanocomposite polypropylene filament yarns with permanent antimicrobial efficiency. The three methods used to mix antimicrobial agents based on silver nano particles with PP were as follows: 1) mixing of PP powder and inorganic nanocomposite filler with the appropriate concentration using a twin-screw extruder and preparing granules, 2) method 1 with a singlerather than twin-screw extruder, and 3) producing the masterbatch by a twin-screw extruder and blending it with PP in the melt spinning process. All pure polypropylene samples and other combined samples had an acceptable spinnability at the spinning temperature of $240^{\circ}C$ and take-up speed of 2,000 m/min. After producing as-spun filament yarns by a pilot plant, melt spinning machine, the samples were drawn, textured and finally weft knitted. The physical and structural properties (e.g., linear density, tenacity, breaking elongation, initial modulus, rupture work, shrinkage and crystallinity) of the as-spun and drawn yarns with constant and variable draw ratios (the variable draw ratio was used to gain a constant breaking elongation of 50%) were investigated and compared, while DSC, SEM and FTIR techniques were used to characterize the samples. Finally, the antibacterial efficiency of the knitted samples was evaluated. The experimental results revealed that the crystallinity reduction of the as-spun yarn obtained from method 1 (5%) was more than that of method 2 (3%), while the crystallinity of the modified as-spun yarns obtained with method 3 remained unchanged compared to pure yarn. However, the drawing procedure compensated for this difference. By applying methods 2 and 3, the drawing generally improved the tenacity and modulus of the modified fibers, whereas method 1 degraded the constant draw ratio. Although the biostatic efficiency of the nanocomposite yarns was excellent with all three methods, the modified fabrics obtained from methods 1 and 2 showed a higher bioactivity.

• 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.

• Journal of Pharmaceutical Investigation
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• v.34 no.6
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• pp.477-482
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• 2004

The aim of the present study was to investigate the efficacy of a mixed gel formulation composed of sodium carboxymethyl cellulose and gellan gum (Na-CMC gel) for the prevention of adhesions after laminectomy. The anti-adhesive effect of the Na-CMC gel was tested in a controlled randomized study using an animal model of lumbar laminectomy. The animals (60 female Sprague-Dawley rats) were randomly allocated into two treatment groups to receive the Na-CMC gel on the injured area or no gel (control). The incidence of adhesions and their grade were blindly evaluated at 4, 8 and 12 weeks after surgery. The amount of scar tissue and tenacity were grossly reduced by the Na-CMC gel at postoperative 4, 8, and 12 weeks. The mean adhesion scores were 0.75, 1.25, and 1.38 at 4, 8, and 12 weeks in the gel-treated group, respectively. No significant inflammatory reaction was observed and the healing of wound was not affected by the Na-CMC gel. The Na-CMC gel reduced the amount of scar formation and tenacity in rat laminectomy model without affecting the healing of operation wound and other complications. Therefore, the Na-CMC gel may be the potential to prevent postsurgical adhesions in clinical state.

• Fibers and Polymers
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• v.7 no.4
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• pp.420-423
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• 2006

Spandex has been successfully applied on modified worsted spinning system to produce spandex core spun yam. However it's difficult to produce wool/spandex core-spun yam on woolen spinning system with the same modified device because the drafting device of the two systems is quite different. A new method is introduced to apply spandex on woolen spinning system in this paper. Core-spun yam produced in this way has good appearance and quality by comparing with normal yam. A series of experiments were carried out to study the influence of spandex drafting ratio and yam twist factor on tensile' properties and elasticity of core-spun yams. The results indicate that core-spun yam with spandex drawing ratio of 2.5 and twist factor of 13.63 has highest value of tenacity and breaking elongation.

• Proceedings of the Korean Geotechical Society Conference
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• 1999.11c
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• pp.21-38
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• 1999

Engineering properties of most polymers used in geosynthetics such as geogrid can be degraded by the chemical reaction (e.g., oxidization, ultraviolet rays, hydrolysis etc.), chemical and mechanical load, microorganism, and so on. In addition, polymer can be damaged by the compaction during construction, and the characteristic of tensile strength of polymer can be changed by the long-term creep effect. In this study, engineering properties of flexible geogrids which are manufactured by weaving/knitting the high-tenacity polymers such as polyester formed in a very open, grid-like configuration, coated with any one of a number of materials (e.g., PVC, latex, etc.), are investigated. Through the analysis of test results, the durability and the long-term design tensile strength of flexible geogrids are evaluated.

• Journal of the Korean Society of Earth Science Education
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• v.7 no.1
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• pp.91-98
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• 2014

The purpose of this study is to compare scientific attitude and degree of satisfaction for school science lessons between science-gifted and general elementary school students. The results of analysis are as follows : 1. Scientific attitude of both groups appeared to be above average and especially science-gifted students demonstrated higher level of scientific attitude in all area. The characteristics of science-gifted tenacity, high motivation, and creativity are demonstrated in their scientific attitudes. 2. Degree of satisfaction about school science lesson for both groups was above average while science-gifted students showed higher degree of satisfaction than general students. 3. Correlation of scientific attitude and science lessons between science-gifted and general students were relatively low. Scientific attitude of science-gifted students are more dependent on other variables than those of science lessons.

• Fibers and Polymers
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• v.3 no.1
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• pp.24-30
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• 2002

Wool yams were coated with conducting Polypyrrole by chemical synthesis methods. Polymerization of pyrrole was caned out in the presence of wool yarn at various concentrations of the monomer and dopant anion. The changes in tensile, moisture absorption, and electrical Properties of the yam upon coating with conductive polypyrrole are Presented. Coating the wool yams with conductive Polypyrrole resulted in higher tenacity, higher breaking strain, and lower initial modulus. The changes in tensile properties are attributed to the changes in surface morphology due to the coating and reinforcing effect of conductive Polypyrrole. The thickness of the coating increased with the concentration of p-toluene sulfonic acid, which in turn caused a reduction in the moisture regain of the wool yin. Reducing the synthesis temperature and replacing p-toluenesulfonic acid by anthraquinone sulfonic acid resulted in a large reduction in the resistance of the yam.

• Textile Coloration and Finishing
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• v.15 no.6
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• pp.33-38
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• 2003

This study surveys the effects of POY physical properties and processing conditions of belt texturing machine to the textured yarns. The various textured yarns are made with the variations of 1st heater temperature, draw ratio, velocity ratio, and the physical properties of these specimens such as yam linear density, tenacity, breaking strain, and wet and dry thermal shrinkages are measured and analysed with the various processing conditions of texturing machine. Especially, the thermal characteristics of the textured yarns, which are affected at the fabric hands and the determination of the processing conditions in the dyeing and finishing processes, are investigated through the thermal stress analyser and DSC experiments.

• Textile Coloration and Finishing
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• v.20 no.2
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• pp.47-52
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• 2008

Nylon textured yarn is usually manufactured by disk type false twist texturing. Dyeing properties of nylon textured yam have not been studied yet. In this study, dyeing properties of nylon textured yam according to draw ratio out of process parameters were investigated. The fact that microstructure of nylon textured yarn in amorphous region particularly is transformed by draw ratio was confirmed indirectly by measurement of dyeing rate because dyeing rate was affected by the structure of amorphous region. Dyeing rate at draw ratio 1.29 was the lowest because the higher draw ratio increase amorphous orientation and disturb dye diffusion into amorphous region. The microstructure according draw ratio was indirectly confirmed by 5% strength, tenacity, elongation. But difference in K/S value and fastness was insignificant.