• Journal of the Korean Chemical Society
• /
• v.24 no.2
• /
• pp.155-166
• /
• 1980

3-(N-Carbonylpyrrolidone)-propanoic acid potassium-salt and 3-(N-carbonylpyrrolidone)propenoic acid potassium-salt were synthesized by the reaction of 2-pyrrolidone potassium-salt with succinic anhydride and maleic anhydride in acetone and in acetone and in benzene. The anionic polymerization of 2-pyrrolidone with 3-(N-carbonylpyrrolidone)-propanoic acid potassium-salt or 3-(N-carbonylpyrrolidone)-propenoic acid potassium-salt as an initiator and potassium hydroxide as a catalyst was studied. It was found that 2.0 and 1.0 mole %, concentration of catalyst and initiator, and temperature of $50^{\circ}C$ was the optimum condition obtaining highest conversion and viscosity of polymer. The inherent viscosity of nylon 4 was measured to be 1.2 dl/g and 2.3 dl/g.

• Journal of the Korean Home Economics Association
• /
• v.41 no.1
• /
• pp.249-257
• /
• 2003

For the efficiency in extracting gromwell colorant, methanol, ethanol and aceton were used as solvents. Also, to compare the results when dyed in various conditions and on various fabrics, the ratio of water-dye mixture, pH, temperature, and varieties of fabrics -wool, silk, cotton, nylon, ramie- were selected. L, a, b, ΔE, munsell and K/S value of each sample was measured and compared for the practical use. Water-dye mixture of 5:5 ratio showed the optimum dyeability. Not to mention wool and silk, but also cotton showed a satisfying dying result at the acidity of pH4. As the temperature increased, the dyeability of all three fabrics improved greatly. Especially, wool showed the highest improvement in terms of dyeability as the temperature increased. K/S values for wool and nylon showed superior results to the others in the gromwell colorant. The resulting color turned out somewhat different depending on the solvents used and the sort of fabric that was tested on. When the gromwell colorant extracted with methanol or ethanol was applied, the color of fabrics came out as purple or purpleblue. When the colorant extracted with acetone was used, the color of fabrics came out to be redpurple. The colorfastness to light showed low glades regardless to whichever solvents were used. The grades of colorfastness to laundering were recorded low numerical values, and its record became even lower when the gromwell colorant extracted with aceton was applied. The staining grade of the colorfastness to laundering showed a good grade in the range of 4 to 5. All the dyed fabrics showed a excellent drycleaning fastness.

• Journal of the Korean Society of Radiology
• /
• v.15 no.2
• /
• pp.181-189
• /
• 2021

This study is a prior research to manufacture a thermoplastic mask, which is a fixture used in radiation therapy, by 3D printing. It proceeded to analyze the filament material that can replace the thermoplastic. Among the commercially available filament materials, a material having similar characteristics to that of a thermoplastic mask was selected and the radiation dose was compared and analyzed. The experiment used Monte Carlo simulation. The shape in which the mask fixed the head was simulated for the ICRU sphere. The photon fluence was calculated at the skin Hp (0.07), the lens Hp (3), and the whole body Hp (10) by applying a thermoplastic plastic material and a filament material. As a result, when looking at the relative dose based on the thermoplastic plastic material, the difference was approximated within 4%. The material showing the most similar dose was PA-nylon. In selecting an appropriate filament material, it should be selected by comprehensively considering various conditions such as economical efficiency and radiation effects. It is thought that the results of this study can be used as basic data.

• Science of Emotion and Sensibility
• /
• v.26 no.4
• /
• pp.41-50
• /
• 2023

This study aims to develop electromyography (EMG) textile electrodes and assess their performance and signal stability by examining variations in layer count and fabric types. We fabricated the electrodes through layering and pressing techniques, focusing on configurations with different layer counts (Layer-0, Layer-1, and Layer-2). Our findings indicate that layer presence significantly influences muscle activation measurements, with enhanced performance correlated with increased layer numbers. Subsequently, we created electrodes from five distinct fabrics (neoprene, spandex cushion, 100% polyester, nylon spandex, and cotton canvas), each maintaining a Layer-2 structure. In performance tests, nylon spandex fabric, particularly heavier variants, outperformed others, while the spandex cushion electrodes showed superior stability in muscle activation signal acquisition. This research elucidates the connection between electrode performance and factors like layer number and electrode-skin contact area. It suggests a novel approach to electrode design, focusing on layer properties and targeted pressure application on specific sensor areas, rather than uniformly increasing sleeve pressure.

• Mycobiology
• /
• v.35 no.4
• /
• pp.191-195
• /
• 2007

The colonization pattern and extent of decay produced in paddy stubble by soil inhabiting mycoflora were done by using nylon net bag technique. Among the three methods used for isolation of fungi, dilution plate technique recorded the highest number of fungi followed by damp chamber and direct observation method. Nutrient availability and climatic conditions (temperature, humidity and rainfall) influenced the occurrence and colonization pattern of fungi. Maximum fungal population was recorded in October ($48.99{\times}10^4/g$ dry litter) and minimum in May ($11.41{\times}10^4/g$ dry litter). Distribution of Deuteromycetous fungi was more in comparison to Zygomycetes, oomycetes and ascomycetes. In the early stage of decomposition Mucor racemosus, Rhizopus nigricans, Chaetomium globosum and Gliocladium species were found primarly whereas at later stages of decomposition preponderance of Aspergillus candidus, Torula graminis, Cladosporiun cladosporioides and Aspergillus luchuensis was recorded.

• The Korean Journal of Malacology
• /
• v.29 no.1
• /
• pp.83-85
• /
• 2013

Size-mass relationships were estimated for 4 species belonging to genus Semisulcospira from the Guem River, Korea. These 4 freshwater snail species: Semisulcospira libertina, Semisulcospira coreana, Semisulcospira gottschei, and Semisulcospira forticosta. Between June and November 2011, samples were caught by dredge (mesh size 10mm of multifilament nylon, total length 4.35 m) at depths of < 2 m. Estimates of for parameter b of the size-mass relationship (W = $aSH^b$) ranged between 2.0072 (Semisulcospira libertina) and 2.3463 (Semisulcospira gottschei).

• Journal of the Korean Society of Clothing and Textiles
• /
• v.32 no.6
• /
• pp.882-889
• /
• 2008

Three fabrics, 100% silk, nylon and cotton each, were dyed with a lichen dye solution prepared by a fermentation method under conditions of varying dyebath pH and temperature. To verify the effect of chitosan on fabric dyeing, the 100% cotton fabric was treated with a chitosan solution before dyeing. The K/S, CIE $L^*$, $a^*$, $b^*$, ${\Delta}E$ and Munsell values of the dyed samples were measured. Colorfastness of each sample was also investigated. The maximum K/S value was measured at 520nm wavelength for the dyed silk fabric and at 480nm for the dyed cotton and nylon. The K/S values for the dyed silk fabric were much greater than those of the other fabrics. The dyed silk fabric showed a red tone on the Munsell color system, and the dyed nylon and cotton fabrics a yellowish red tone. Dye affinity to fabrics was better in a neutral or acidic dyebath. As dyeing temperature increased, K/S values increased for the dyed nylon and cotton fabrics but not for the silk. Dyeability of cotton fabrics could improve by Chitosan treatment. As for most natural dyes, colorfastness of all dyed samples was poor. The silk fabric showed an excellent dry cleaning fastness of Grade 5.

• Journal of the Korean Society of Clothing and Textiles
• /
• v.22 no.4
• /
• pp.515-524
• /
• 1998

The purpose of this study was to evaluate the thermal properties of ceramics coated nylon fabrics by determining far infra-red emissive properties, heat storage/release and thermal insulation. Far IR emissivity and emissive power were measured for 7~ 140n at 50'C . Three types of ceramics such as cordierite with $\alpha$-alumina, a-alumina with titanium oxide and a-alumina were chosen as specimens. Cordierite with $\alpha$-alumina was chosen to treat on the fabrics due to the good emissive properties on the fabrics. Add-ons and contents of ceramics were analyzed for ceramics and/or polyurethane coated fabrics. For the physical properties, thickness and air permeability were measured. Results showed a difference in the emissive property between ceramics themselves and ceramics coated fabrics. In the ambient temperature, there was no diffenence in emissivity among the different ceramics contents. Thermography showed that when the fabric was heated with the light, surface mean temperatures of fabrics were increased as the contents of ceramics increased, and the heat storage property was confirmed. In case of same thickness and air permeability, the thermal insulation value increased as the contents of ceramics increased because of increasing heat storage and Far IR reflectivity. So there were absorption and heat storage of ceramics for Far IR from human and reflection to human between ceramics coated fabrics and human.

• Asian-Australasian Journal of Animal Sciences
• /
• v.17 no.10
• /
• pp.1430-1433
• /
• 2004

A study was conducted to determine the effect of different alkali treatments on changes in chemical composition and on degradability of bagasse and rice straw. This study divided into 2 experiments, the first with bagasse and the second with rice straw. Each experiment comprised 9 treatments which included: untreated control; 3% NaOH; 6% NaOH; 3% urea; 6% urea; 3% NaOH/3% urea; 3% NaOH/6% urea; 6% NaOH/3% urea; 6% NaOH/6% urea. In both experiments, crude protein contents were increased from 2.0 to 12.5 units for bagasse and 3.1 to 13.7 units for rice straw by urea treatments. Ash contents of the treated bagasse and rice straw were increased over the untreated control (1.5-9.7 units for bagasse; 4.2-8.8 units for rice straw). The effects on ether extract, crude fiber, neutral detergent fiber and acid detergent fiber of the treated bagasse and rice straw were variable. Nylon bag degradability of dry matter and crude fiber were increased by treatments applying NaOH and NaOH plus urea but not urea alone. In contrast, the egradability of neutral detergent fiber and acid detergent fiber were reduced compared with the untreated control. From these degradability studies, it can be concluded that the most efficient treatments of bagasse were those treatments with 6% NaOH, followed by treatments with 6% NaOH plus 3% or 6% urea and 3% NaOH plus 3% or 6% urea, respectively. However, when comparison was made on the cost of chemical used to treat the agricultural by-products, particularly in case of rice straw, 3-6% urea would be appropriate.

• Textile Coloration and Finishing
• /
• v.18 no.4
• /
• pp.43-48
• /
• 2006

A phthalocyanine reactive dye was applied to nylon fibers to study the effects of the temperature and pH on % exhaustion and fixation. In addition, appropriate predictable empirical models, relatively new approaches in dyeing process, were developed incorporating interactions effects of temperature and pH for predicting the both % exhaustion and fixation. The significance of the mathematical model developed was ascertained using Excel regression (solver) analysis module. A very high correlation coefficient was obtained ($R^2=0.9895$ for % exhaustion, $R^2=0.9932$ for fixation) for the model which shows prominent prediction capacity of the model for the unknown conditions. The predictable polynomial equations developed from the Experimental results were thoroughly analyzed by ANOVA (Analysis of Variance) statistical concepts.