• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.19 no.11
• /
• pp.688-694
• /
• 2018

The mixture ratio of two-component liquid silicone is important for the inherent physical characteristics of the finished product. Therefore, it is necessary to uniformly control the ratio of the main material and the sub-material. In this paper, a mixing-ratio control system was designed, which consists of a digital flow meter and a flow control system to measure the flow rate of the raw materials and a pumping system to maintain constant pressure and transfer of the raw materials. In addition, a program was developed to control the organic interlocking and mixing ratio. For the verification of the developed system, we compared the actual weight of raw material with the value measured by the flow meter during pumping, and we measured the physical properties of the mixed material by making test samples with and without the application of the mixing-ratio improvement algorithm. The measured value was close to the reference value with a hardness range of 46-47 and tensile strength of 9.3-9.5 MPa. These results show that the mixing ratio of the liquid silicone is controlled within an error range of ${\pm}0.5%$.

• The Journal of Korean Academy of Orthopedic Manual Physical Therapy
• /
• v.11 no.2
• /
• pp.40-48
• /
• 2005

In this study, the muscle strength and endurance of the lumbar at flexion and extension were determined using an isokinetic muscle strength meter (Biodex) in patients with chronic lumbar go (10 male and 10 females), and the changes in muscle strength and endurance of the lumbar at flexion and extension after application of Y-shaped sacrospinalis muscle taping, typically used for patient with lumbar go, were studied. In addition, the sacrospinalis muscle taping of a different shape (I-shaped taping) was applied bilaterally centering on the spine, and the muscle strength and endurance of the lumbar at flexion and extension were determined and compared with those before taping. In addition, the results after application of Y-shaped taping and I-shaped taping were also compared. 1. The extensor muscle strength of the lumbar at loading of $60^{\circ}$/sec before application of kinesio Taping and after application of Y-shaped taping showed the level of significance (p<.05). The flexor muscle strength of the lumbar at loading of $60^{\circ}$/sec before application of kinesio taping and after application of Y-shaped taping did not show the level of significance. 2. The flexor muscle endurance of the lumbar at loading of $90^{\circ}$/sec before application of kinesio Taping and application of Y-shaped taping did not show the level of significance. The extensor muscle endurance of the lumbar at loading of $90^{\circ}$/sec before application of kinesio Taping and after application of Y-shaped taping did not show the level of significance. 3. The extensor muscle strength of the lumbar at loading of $60^{\circ}$/sec before application of kinesio Taping and after application of I-shaped taping showed the level of significance (p<.05). The flexor muscle strength of the lumbar at loading of $60^{\circ}$/sec before application of kinesio Taping and after application of I-shaped taping showed the level of significance (p<.05). 4. The flexor muscle endurance of the lumbar at loading of $90^{\circ}$/sec before application of kinesio taping and after application of I-shaped taping showed the level of significance. The extensor muscle strength of the lumbar at loading of $90^{\circ}$/sec before application of kinesio Taping and after application of I-shaped taping showed the level of significance (p<.05). 5. In comparison between after application of Y-shaped taping and after application of I-shaped taping, the flexor muscle strength of the lumbar at loading of $60^{\circ}$/sec did not show the level of significance. In comparison between after application of Y-shaped taping and after application of I-shaped taping, the extensor muscle strength of the lumbar at loading of $60^{\circ}$/ sec showed the level of significance (p<.05). 6. In comparison between after application of Y-shaped taping and after application of I-shaped taping, the flexor muscle strength of the lumbar at loading of $90^{\circ}$/sec did not show the level of significance. In comparison between after application of Y-shaped taping and after application of I-shaped taping, the extensor muscle strength of the lumbar at loading of $90^{\circ}$/sec did not showed the level of significance (p<.05).

• Asian-Australasian Journal of Animal Sciences
• /
• v.16 no.2
• /
• pp.269-276
• /
• 2003

We studied the gel properties of porcine collagen with microbial transglutaminase (MTGase) as a catalyst. A creep meter was used to measure the mechanical properties of gel. The results showed samples with high concentration of MTGase gelled faster than those with a low concentration of MTGase. The gel strength increased with incubation time and the peaks of breaking strength for 0.1, 0.2 and 0.5% MTGase were obtained at 40, 20 and 10 min incubation time, respectively. According to SDS-PAGE, the MTGase was successfully created a collagen polymer with an increase in molecular weight, whereas no change in formation was shown without MTGase. The sample with 0.5% MTGase began to polymerize after 10 or 20 min incubation at $50^{\circ}C$, and complete polymerization occurred after 40-60 min incubation. Scanning electron microscopic analysis revealed that the gel of porcine collagen in the presence of MTGase produced an extremely well cross-linked network. The differential scanning calorimetric analysis showed the peak thermal transition of porcine collagen gel was at $36^{\circ}C$, and that with MTGase no peak was detected during heating from 20 to $120^{\circ}C$. The melting point of porcine collagen gel could be controlled by MTGase concentration, incubation temperature and protein concentration. Knowledge of the structural and physicochemical properties of porcine collagen gel catalyzed with MTGase could facilitate their use in food products.

• KSBB Journal
• /
• v.5 no.3
• /
• pp.215-221
• /
• 1990

The solubilization of BSA, pepsin, trypsin and ribonuclease-a in cationic reverse micellar solutions has been investigated. For complete solubilization into reverse micellar solutions, pH values of several pH units above the isoelectric point of each protein were required. Solubilization was observed to decrease with increasing ionic strength of KCI. The size of empty micelles showed no significant change with increasing ionic strength. Trioctylmethyl ammonium chloride (TOMAC) in cyolohexane showed the lowest solubilization for the proteins. The system didodecyl dimethyl ammonium bromide (DDAB)-tetrachloroethylene was capable of solubilizing larger amounts of proteins than the system DDAB-benzene. Cetyl trimethyl ammonium bromide(CTAB)-hexanol-isooctane system showed lower solubilization than DDAB-tetrachloroethylene system, while it had higher Wo value.

• Culinary science and hospitality research
• /
• v.23 no.4
• /
• pp.116-124
• /
• 2017

This study was investigated quality characteristics of gluten-free noodles added guar gum and basil seed gum (BSG). Gluten-free noodles were prepared using corn flour and corn starch and added 1% and 2% of guar gum and basil seed gum. Water binding capacity was measured by centrifuge, and moisture content was obtained by moisture analyzer. Color of noodles was measured from the midsection of noodles. Water absorption of noodles was calculated by weight of uncooked and cooked noodles. pH of noodles was measured by pH meter. Texture and tensile strength were obtained by rheometer. SPSS 12.0 program was used for significant differences by Duncan's multiple range test. Water binding capacity of noodles was the highest in 2% basil seed gum but 1% guar gum was the lowest. Moisture content was not different in uncooked noodles, but 1% guar had the highest moisture content in cooked noodles. Water absorption of noodles was high in basil seed gum group. pH of noodles was more increased in guar gum additions than basil seed gum additions. For hardness, control had the lowest as 16.09 N, but 2% guar gum showed the highest as 28.40 N. Tensile strength of noodles was increased by adding gums. These results suggested that 1% basil seed gum could be good materials for manufacturing gluten-free noodles in order to improve quality characteristics.

• Journal of the Korean Society of Marine Environment & Safety
• /
• v.24 no.5
• /
• pp.604-610
• /
• 2018

Recently, due to the rapid growth of the leisure industry, demand for small-scale flotation and mooring pontoon platforms has been increasing rapidly. Standard rules for the design and structural safety of such structures have become necessary. This paper provides criteria that can be referenced when designing pontoon platforms, and also introduces structural safety evaluation procedures. In this study, the structural safety and stability of a 15-meter pontoon platform were investigated through structural design and finite element analysis. For platforms of less than 10 meters in length, a simple structural calculation can be used, but for platforms over 10 meters, a detailed structural strength review must be considered to meet safety guidelines defined in existing regulations. The structural strength of the initial design was examined and its structural safety was verified. For future research, it is an evaluative system was developed that can be used to examine the various loading conditions during design.

• Journal of the Korean Recycled Construction Resources Institute
• /
• v.8 no.2
• /
• pp.204-211
• /
• 2020

Poly-Lactic Acid(PLA) fiber is an eco-friendly material and is biodegradable, so it can be utilized for manufacturing porous construction materia ls with interna l pore connection. In this study, domestic PLA fiber products(0.5mm india meter, 1.0mm in length, 10mm in length) were tested for melting at high temperatures and high alkality, and they were incorporated with FA-based geopolymer. Compressive strength was obtained through high temperature curing and alkali activator, however the complete melting of the PLA fiber was not ensured. The previous study handling PLA fiber with 0.003mm in diameter was completely dissolved, but 0.5mm and 1.0mm in diameter showed 42.5% and 33.3% of dissolution ratio, respectively. In addition, the increasing fiber volume led floating fibers during curing, which had a negative effect on its workability and solubility. Although the properties of PLA fiber may vary depending on the raw materials and production conditions, PLA fiber with 0.1mm or less diameter is recommended for porous construction material.

• International Journal of Naval Architecture and Ocean Engineering
• /
• v.2 no.1
• /
• pp.45-56
• /
• 2010

Polymer composite materials offer high strength and stiffness to weight ratio, corrosion resistance, and total life cost reductions that appeal to the marine industry. The advantages of composite construction have led to their incorporation in U.S. yacht hull structures over 46 meters (150 feet) in length. In order to construct even larger hull structures, higher quality composites with lower cost production techniques need to be developed. In this study, the effect of composite hull fabrication processes on mechanical properties of glass fiber reinforced plastic (GFRP) composites is presented. Fabrication techniques investigated during this study are hand lay-up (HL), vacuum infusion (VI), and hybrid (HL+VI) processes. Mechanical property testing includes: tensile, compressive, and ignition loss sample analysis. Results demonstrate that the vacuum pressure implemented dining composite fabrication has an effect on mechanical properties. The VI processed GFRP yields improved mechanical properties in tension/compression strengths and tensile modulus. The hybrid GFRP composites, however, failed in a sequential manor, due to dissimilar failure modes in the HL and VI processed sides. Fractography analysis was conducted to validate the mechanical property testing results.

• 한국신재생에너지학회:학술대회논문집
• /
• 2010.11a
• /
• pp.76.1-76.1
• /
• 2010

Recently, many efforts to solve the durability problem of PEM fuel cell are carried on constantly. However, despite this attention, durability researches of gas diffusion layer (GDL) are not much reported yet. Generally, GDL of PEM fuel cell experiences three external attacks, which are dissolution of water, erosion of gas flow, corrosion of electric potential. In this study, among these degradation factors, carbon corrosion of electric potential was focused and investigated with accelerated carbon corrosion test. Through the test, it is confirmed that carbon corrosion occurred at GDL, and corroded GDL decreased a performance of operating fuel cell. The property changes of GDL were measured with various methods such as air permeability meter, pore distribution analyzer, thermo gravimetric analyzer, and tensile stress test to discover the effects of carbon corrosion. Carbon corrosion caused not only loss of weight and thickness, but also degradation of mechanical strength of GDL. In addition, to analysis the reason of GDL property changes, a surface and a cross section of GDL were observed with scanning electron microscope. After 100 hours test, the GDL showed serious damage in center of layer.

• Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
• /
• 2001.10a
• /
• pp.103-107
• /
• 2001

The major studies of an ocean circulation of the East/Japan Sea related to evaluate the feasibility and utilization of deep ocean water are reviewed. The major feature of surface current system of the East/Japan Sea is an inflow of the Tsushima Warm Current through the Korea/Tsushima Strait and the outflow through the Tsugaru and Soya Straits. The Tsushima Warm Current has been known to split into two or three branches in the southern region of the East/Japan Sea. In the cold water region of the East/Japan Sea, the North Korean Cold Current turns to the east near 39$^{\circ}$N after meeting the East Korean Warm Current, then flows eastward. The degree of penetration depends on the strength of the positive wind stress curl, according to the ventilation theory. Various current meter moorings indicate strong and oscillatory deep currents in various parts of the basin. According to some numerical experiments, these currents may be induced by pressure-topography or eddy-topography interaction. However, more investigations are needed to explain clearly the presence of these strong bottom currents. This study concludes the importance of topographical coupling, isopycnal outcropping, different wind forcing and the branching of the Tsushima Warm Current on the circulation of the East/Japan Sea.