• Fibers and Polymers
• /
• 제7권1호
• /
• pp.51-56
• /
• 2006

Power net fabric is one of the highly extensible two-way fabrics. Power net structure shows special characteristics in the wearing of final functional clothes. This research evaluated effects of treatment temperature on proportional extensibility and shrinkage ratio of spandex at a given wale length. As treatment temperature increased, extensibility increased proportionally to the standard length of the sample and the shrinkage ratio in the direction of course and wale increased. The pulling-out length increased proportionally to the standard length of the sample. However it was affected by the effect of treatment time and temperature due to the thermal properties of spandex filament yarn.

• 한국의류학회지
• /
• 제25권1호
• /
• pp.61-70
• /
• 2001

As important factors determining human sensorial comfort, liquid moisture management and surface properties of heat resistant workwear materials were examined. To figure out liquid moisture management properties of the test materials, absorption capacity, rate of absorption, and evaporation properties were assessed. A modified GATS(Gravimetric Absorbency Testing System) was used to measure the liquid moisture accumulation associated with the wicking of liquid moisture from sweating skin. The GATS procedure measures demand wettability of materials to take up liquid in a direction perpendicular to the fabric surface and it was modified to incorporate a special test cell and cover to assess absorption behavior in the presence of evaporation. Fabric stiffness, smoothness, number and the length of surface fibers, and an estimate of the contact area between the skin and fabric surface were measured to characterize the mechanical and surface properties of the test materials. Also an estimate of the force with which a fabric clings to moist skin was made using as wet-cling index.

• 대한후두음성언어의학회지
• /
• 제10권1호
• /
• pp.37-42
• /
• 1999

The vocal fold has three major function-phonation, respiration and protection, and is richly innervated. The vocal 1314 its autonomic innervation-adrenergic and cholinergic from superior cervical ganglion and the vagus nerve, respectively. The action of both system account for vasoregulation and glandular activity. In e vocal fold several kin of neuropeptides, including SP, CGRP, VIP, TH, NPY, ENK have been reported at the animal including cat or dog. But information regarding the distribution of autonomic nerve fibers containing neuropeptides in the human vocal fold is lacking. Two neuropeptides are of special interest : 1) vasoactive intestinal polypeptide(VIP)that is known to be contained in the parasympathetic(cholinergic) neuron. 2) tyrosine hydroxylase(TH)is located in the cytoplasm of noradrenergic neuron and is the rate-limiting enzyme in noradrenaline synthesis. To understand specific autonomic function of vocal fold we did immunohistochemical examination of VIP and TH in the human vocal fold.

• 펄프종이기술
• /
• 제39권5호
• /
• pp.26-31
• /
• 2007

Hanji is a traditional Korean handmade paper, which has been known in ancient Far East as excellent quality calligraphic paper for more than 1,500 year. Hanji is mostly made of Korean paper mulberry bast fibers, and if properly processed, normally lasts for more than 1,000 years with significant strength and still recognizable calligraphic writings or drawings on it. Dochim is a special way of Hanji calendering process, but is turned out to be quite different from modern calendering (machine calendering) in several aspects. In Dochim process, mechanical impacts were applied vertically to the surface of papers. Compared to the modern calendering, Dochim increased paper gloss much more, but paper smoothness a little less. By the Dochim process, densification occurred and the degree of densification was more sensitive to the fiber type in the Dochim process than in the calendering method.

• Fibers and Polymers
• /
• 제4권4호
• /
• pp.161-168
• /
• 2003

An investigation of the dimensionless torque in the newly developed cone drum twister texturing mechanism is reported. The cone drum twister is one of the outer surface contacting friction-twisting devices in false-twist texturing. In this cone drum twister, a filament yam passes over the surface of the cone drum that rotates by the passing yarn without a special driving device. This research is composed of the theoretical analysis of the false twisting mechanism and the experimental analysis at room temperature. The equations have been derived which shows interrelationship of the conical angle of cone drum, the wrapping angle, the drag angle, and the yam helix angle. Theoretical values of dimensionless torque were calculated and were compared with the experimental results. It is shown that, as the conical angle and the projected wrapping angle increased, the dimensionless torque also increased. But the conical angle was reached to ${30.75}^{\circ}C$, the dimensionless torque decreased.

• 대한수학회보
• /
• 제54권5호
• /
• pp.1527-1575
• /
• 2017

In a spirit of Givental's constructions Batyrev, Ciocan-Fontanine, Kim, and van Straten suggested Landau-Ginzburg models for smooth Fano complete intersections in Grassmannians and partial flag varieties as certain complete intersections in complex tori equipped with special functions called superpotentials. We provide a particular algorithm for constructing birational isomorphisms of these models for complete intersections in Grassmannians of planes with complex tori. In this case the superpotentials are given by Laurent polynomials. We study Givental's integrals for Landau-Ginzburg models suggested by Batyrev, Ciocan-Fontanine, Kim, and van Straten and show that they are periods for pencils of fibers of maps provided by Laurent polynomials we obtain. The algorithm we provide after minor modifications can be applied in a more general context.

• International Journal of Aeronautical and Space Sciences
• /
• 제11권4호
• /
• pp.266-284
• /
• 2010

Piezoelectric materials have become the most attractive functional materials for sensors and actuators in smart structures because they can directly convert mechanical energy to electrical energy and vise versa. They have excellent electromechanical coupling characteristics and excellent frequency response. In this article, the research activities and achievements on the applications of piezoelectric materials in smart structures in China, including vibration control, noise control, energy harvesting, structural health monitoring, and hysteresis control, are introduced. Special attention is given to the introduction of semi-active vibration suppression based on a synchronized switching technique and piezoelectric fibers with metal cores for health monitoring. Such mechanisms are relatively new and possess great potential for future applications in aerospace engineering.

• 보존과학회지
• /
• 제5권1호
• /
• pp.3-10
• /
• 1996

In this study, bast fibers, woody parts and whole woods were pulped separately by alkali, alkali-hydrogen peroxide and sulfomethylated processes and their papermaking characteristics for the special Hanji were evaluated. Also properties of new Hanji products obtained from mixed stocks of various ratios were discussed. Solfomethylated pulps were shown higher brightness and sheet strengths than those from alkali and alkali-peroxide pulps. On the mechanical properties of Hanjis mixed with bast-and woody-parts pulps, and with bast and whole stem pulps, handsheet strengths were decreased with the increasing contents of woody and whole stem pulps. Various Hanjis could make by various mixing of separated cooked Pulps. Especially an excellant Hwaseonji(calligrapy Paper) could be made by one stage cooking of whole stem of paper mulberry by sulfomethylated pulping method.

• Applied Microscopy
• /
• 제42권4호
• /
• pp.223-227
• /
• 2012

Focused Ion Beam (FIB) systems have incorporated versatile nanomanipulators with inherent sophisticated machining capability to characterize the electrical properties of highly miniature components of electronic devices. Carbon fibers were chosen as a model system to test the applicability of nanomanipulators to microscale electronic materials, with special emphasis on the direct current current-voltage characterizations in terms of electrode configuration. The presence of contact resistance affects the electrical characterization. This resistance originates from either i) the so-called "spreading resistance" due to the geometrical constriction near the electrode - material interface or ii) resistive surface layers. An appropriate electrode strategy is proposed herein for the use of FIB-based manipulators.

• Advances in materials Research
• /
• 제4권4호
• /
• pp.207-214
• /
• 2015

It has been reported in the technical literature that orotic acid can be used in order to induce improved crystallization of biodegradable and biocompatible polymers like poly(L-lactic acid), polyhydroxybutyrate and poly(hydroxybutyrate-co-hydroxyhexaonat). The expected advantage of the changed crystalline structure is a reinforcing effect of the polymers. A lot of papers reported about the application of inorganic and organic agents for acceleration of heterogeneous nucleation. This study reports on an attempt to use orotic acid as appropriate non-toxic nucleating agent for improving mechanical properties of isotactic polypropylene. Special attention is given to demonstrate the effect of nucleation in a typical melt spinning process in order to improve the mechanical properties. The effects were demonstrated using rheology, thermal analysis and tensile testing.