Ring spun yam is the most widely used yarn type, especially for quality staple yarns. But the exact structure of the ring spun yarn is not known and the structure is explained only qualitatively. This study suggests a method for determining the structural characteristics quantitatively, defining a packing density (unction and a migration factor. The results show that ring spun yarn has a maximum packing density at around 2/3 of the yarn radius. The fibers in the yarn center are arranged parallel or with a small angle to the yarn axis, which is different from what has been known to us. The migration factor of a ring spun yarn ranges from 0.76 to 1.29. depending on the twist level that affects the fiber migration positively.

The return spring which is one of main elements in a dobby system is often fractured during working. The failure mechanism is investigated experimentally and analytically, and the type of failure is proved as fatigue fracture by repeated loads. The fracture angle of the spring is in good agreement with the result obtained by theoretical analysis. The closed form solution related to the deflection and maximum stress is also derived, which can be applied directly to the design of the return spring.

A fundamental algorithm to simulate nanoweb morphology was developed. A nanofiber was generated by connecting beads of a fixed diameter. A single-layed nanoweb was created by repeating the nanofiber generation subroutine. The final nanoweb was constructed by superposing several layers of the simulated single-layered nanoweb. To estimate the pore size of the simulated nanoweb, an estimating algorithm was developed using a ghost particle having 0 mass and 0 volume. To assess the pore size and its distribution of the simulated nanoweb, the number of steps of the ghost particle to penetrate the web was measured.

Recently, much attention has been paid to chitosan($\beta$-(1,4)-2-deoxy-2- amino-D-glucopyranose(mainly)), which is used for antimicrobial and deodorization finishing of cellulose. In this study, we made conjugated cotton with chitosan skin using a new method of applying chitosan onto cellulose. To make conjugated cotton with chitosan skin, raw cotton was dipped in chitosan solution, mangled, neutralized in NaOH solution, washed, and finally dried. As the concentration of the chitosan solution increased, the chitosan contents of conjugated cotton with chitosan skin increased. However, it is not affected by the concentration of acetic acid and NaOH solution, and mangle pressure. Cotton must be treated with over 2 wt% chitosan solution to get 99.9% bacteriostatic ratio. And cotton, dipped in over 4 wt% chitosan solution, is difficulty to process because of excess of chitosan, so cotton was treated with less 4 wt% chitosan solution. From the study of chitosan durability, it appears that chitosan contents decrease by 9.9% on treatment in high-temperature water. And chitosan contents decrease at the first washing, but the decrease is less after that. It is expected from this results that conjugated cotton with chitosan skin can be used as raw material of functional products and this study can be applied as basic research significantly in study for various functional materials.

Polyvinylidene fluoride-hexafluoropropylene (PVDF- HFP)/acetone solutions were electrostatically spun into sub-micron fibers at various conditions. The variables chosen were polymer concentration, applied voltage, flow rate, and tip to collector distance (TCD). The average fiber diameter increased with an increase in the polymer concentration, however, the trend for applied voltage was not monotonous showing minimum diameter of 0.8 ${\mu}{\textrm}{m}$ at 15.6 kV. The fiber diameter was also depended on TCD; the minimum fiber diameter at 15cm. The flow rate of the solution was another factor; lower the flow rate, finer the fiber diameter. The PVDF-HFP web was also treated for air filter application i.e., water contact angle and air permeability. Though the web was consiting of ultra-fine fibers, the contact angle with water was still high as 157$^{\circ}$ representing high hydrophobicity. The web showed high air permeability of 12.69 cc/$\textrm{cm}^2$. sec, and the value decreased with increase in thickness of the web.

Cotton fabrics treated with chitosan showed great improvement in fabric properties. When the add-on ratio over 0.647%, finished cotton fabrics had superior antibacterial activity. However, cotton fabrics treated by chitosan solution of high concentration exhibited increased bending rigidity and change in several physical and mechanical properties, but finished cotton fabrics had a hard touch. So, silicon softener was added to improve touch. The outstanding properties of cotton fabric treated with chitosan silicon solution had antibacterial activity, unique soft hand and durable press property. This experiment was proceed through 1 step process with chitosan and silicon softener. 1 step process takes the advantage of this experiment. Finished cotton fabrics were investigated; antibacterial activity test, moisture regain test, KES-Fb system(Kawabata Evaluation System, Kato Tech. Co. Ltd., Japan) test, scanning electron microscope(SEM). It was confirmed that the hand values of finished cotton fabrics were excellent in the CS-1.

Low temperature plasma treatment with different treatment times (0, 1, 3, 5 and 10 minute) was used to study the detergency of PET fabrics. Plasma treated and untreated fabrics were soiled with three different soils of carbon black mixed with oily soils, hemoglobin and triolein, and washed by using Terg-O-Tometer at 4$0^{\circ}C$ with 40 rpm. In order to assess degree of soil removal of the three soils, following analysis was carried out to each soils on the fabrics : surface reflectance was measured to evaluate the carbon black mixed oily soil, copper-Folin method was used to quantify the amount of remaining hemoglobin, and radiotracer method was applied to measure the triolein. The deposition behavior of carbon black on plasma treated/untreated PET fabrics has been also investigated in the presence of anionic (AS, AOS) or nonionic (AE) surfactant.

Basic mechanism of sound absorption in various sound absorbing materials is generally explained by the conversion of sound energy into heat energy. The important element governing the conversion from sound into heat depends on the material characteristics. Three types, such as porous, resonance and panel types, generally classify the geometrical structure of sound absorbers. These three types of sound absorbing materials demonstrate different sound absorption characteristics. In this study, for the absorption of the specific sound frequency, various parameters are investigated experimentally using the impedance tube method. The models used in the experiment are porous and panel type absorbers. The porous type absorber generally has the ability of sound absorption at the high frequency range and the panel type absorber has the capability of sound absorption of the specific sound frequency. The sound absorption characteristics of the panel type absorber are described in phenomenon related to the sound absorption characteristics of porous type products. Detail experiments are carried out to clarify the parameters governing the acoustic performance with different fabrics.

Living nature of the cationic polymerization of t-butyl vinyl ether(t-BVE), carried out at -78$^{\circ}C$ in a mixed solvent of toluene and diethyl ether using iodine as initiator has been investigated. The results showing attainment of 100% conversion and a linear dependence of the number average molar mass on % conversion strongly suggests the living nature of the polymerization in a limited range of iodine concentration. It is concluded that the living nature of the polymerization is ascribable to the stability of polarized C-I terminal of adduct, which is formed by the reaction of the monomer with iodine and activated by the pulling action of zinc iodide, which allows the insertion of monomer in both initiation and propagation in cationic nature. However, it is believed that this growing terminal is stable enough to depress the chain breaking process, such as chain transfer or termination. Non-living characteristics appearing at higher temperatures as well as higher iodine concentration was discussed in terms of the equilibrium established between polarized C-I terminal and dissociated carbocationic propagating species where chain breaking process operates. It was also found that highly isotactic poly(vinylalcohol) (PVA) containing more than 70% meso content is obtainable via hydrolysis of corresponding p(t-BVE).

In this work, activated carbons (ACs) containing silver were prepared by anodic oxidation and immersion processes in AgNO$_3$ solution, in order to improve the ammonia removal efficiency and increase their antibacterial activities. The pore and surface properties of ACs were studied in terms of N2/77k nitrogen adsorption measurement, X-ray photoelectron spectrometer (XPS), and scanning electron microscope (SEM). The ammonia removal efficiency was confirmed by gas-detecting tube technique and the antibacterial activities were investigated by dilution test against Staphylococcus aureus (S. aureus; gram positive and virulence) and Klebsiella pneumoniae (K. pnumoniae; gram negative and avirulence). As a result, the specific surface area and micropore volume of ACs decreased slightly with the AgNO$_3$ treatment. However, the AgNO$_3$ treated ACs led to an increase in ammonia removal efficiency, mainly due to an increase in oxygen containing functional groups on ACs surfaces. Also, the antibacterial activities of the AgNO$_3$ treated ACs agianst S. aureus as well as K. pnumoniae predominantly increased, which could be attributed to the presence of silver in Ag/ACs systems.