• Journal of the Korean Society for Precision Engineering
• /
• v.29 no.9
• /
• pp.1012-1019
• /
• 2012

In this study, CNG composite vessel is analyzed by using coupled model with liner and composite layer. For the coupled model, a method using theoretical analysis and FEA is suggested: elastic solution for laminated tube is used for theoretical analysis of the composite vessel, FEA is performed to the model of CNG composite vessel in actual conditions. On the basis of these results, optimal thickness and winding angle of the composite layer considering the material properties and thickness of the liner are determined. The results of theoretical analysis and FEA are compared with those carried out in previous studies for verifying the suggested analysis method.

• Korean Journal of Pharmacognosy
• /
• v.6 no.1
• /
• pp.43-47
• /
• 1975

Attempts were made to determine the characteristics of the morphology of Codonopsis lanceolata $T_{RAUT's}$ root. Its saponin and crude powder were examined by foaming and hemolytic tests and by observing transverse sections: 1) The cork-layer was consisted of multiple cells, and some of the cork cells contained monoclinic prism crystals of calcium oxalates. 2) The vascular bundle was formed of radial arrangement by the preminentic bursting pith and the irregular cambium ring with the abnormal growth. 3) The latex vessel and latex of the cortex were brown-gray or yellowish-brown. The latex vessel and sieve tube were consisted of the independent aggregates which had a number of layers. It had much more independent aggregates than Platycodi Radix. 4) The xylem was less than the phloem portion. The thick-walled vessels which had one to five lines ware more distributed than in Platycodi Radix. 5) The inulin distribution on a piece of section which is dipped in alcohol was observed through out the tissues, but starch grain was not found in it. 6) The duration time of foaming reaction of the crude powder in test tubes was shorter than that of Platycodi Radix. Foaming index of the foaming test of five percent decoctions was 3.33, 7) In the hemolytic test which used 10 percent decoction and one percent saponin solution, hemolytic action was very weak.

• Journal of the Korean Society of Manufacturing Process Engineers
• /
• v.17 no.6
• /
• pp.105-110
• /
• 2018

A concrete docking hose of pump car's boom pipe line have been used in many construction sites. They are long structures with continuous cornering, similar to a trunk of the elephant, characterized by a very high pressure resistance of 20MPa. They need flexible materials and structure in order to move the hose smoothy. But commercial concrete hose is hard to handle and heavy owing to adaption of steel reinforcement. In this study, it is tried an experimental approach to the characteristic of inner rubber layer and abrasion resistance. Also, we are investigated the bursting pressure according to the reinforcement of the hose and propose the usefulness of the hose reinforced with high strengthened aramid fiber.

• Textile Coloration and Finishing
• /
• v.31 no.1
• /
• pp.42-47
• /
• 2019

In this study, the effects of surface treatment of bamboo fiber on the physical properties of polypropylene(PP)/glass fiber(GF)/Bamboo fiber(BF) composite for engine cover were investigated. PP, GF and BF were fixed at 40%, 40% and 20% and the surface of bamboo fibers were treated to 0.5, 1.0 and 2.0% as an acid and alkali solution. PP/GF/BR composites using surface treated bamboo fibers were prepared and their tensile strength, bursting strength and impact strength were measured by universal testing machine(UTM). The composites with alkali treated bamboo fiber showed better mechanical properties than the acid treated composites. It was checked that the optimum alkali content was at 1.0% from the results of mechanical properties. The effect of surface treatment on the mechanical properties was confirmed by SEM images of fractured surface.

• Journal of Apiculture
• /
• v.34 no.2
• /
• pp.131-136
• /
• 2019

Recently, number of honeybees (Apis mellifera) has visibly decreased because they are vulnerable to some diseases like American foulbrood disease. American foulbrood disease, which is caused by Paenibacillus larvae, is emerged as great cause of decrease in number of honeybees. After antibiotic-resistant strain emerged, it is now more difficult to treat those pathogens successfully. Researches on finding alternative antibacterial compound are ongoing. In this study, we examined the antibacterial effect of honokiol on P. larvae. Honokiol showed great antibacterial effect with minimum inhibitory concentration of 12.5 ㎍/mL and minimum bactericidal concentration of 50 ㎍/mL. An agar diffusion test also confirmed the anti-Paenibacillus larvae activity of honokiol with an inhibitory zone of 9±0.5 mm. Since honokiol is known to interact membrane of some bacteria, we measured 260 nm absorbing particles, which could be induced by leakage of cells, and confirmed that the leakage of P. larvae occurred in dose-dependent manners. However, result of crystal violet assay suggested that honokiol has only mild anti-biofilm formation effect on P. larvae, which means honokiol controls the bacteria by inducing the bursting of membrane. Finally, an additive effect of honokiol with tetracycline and terramycin was found using a checkerboard assay with a fractional inhibitory concentration index value of 0.5.

• International Journal of Naval Architecture and Ocean Engineering
• /
• v.12 no.1
• /
• pp.178-183
• /
• 2020

A series of experiments covering lowest three natural frequencies of rolling coupled pitching were conducted to investigate liquid sloshing with low liquid depth. The test results show that the most violent liquid sloshing in rolling and pitching is located in the vicinity of the first order natural frequency (f1). When the excitation frequency of rolling and pitching is located between 0.98f1 and 1.113f1, roof-bursting phenomenon of liquid appeared, and the maximum impact pressure is at 1.09f1. When the external excitation frequency is at 1.113f1, the number of sloshing shocks decreases sharply. Furthermore, the space distribution of the impact pressure on the left bulkhead and the top bulkhead was analyzed. It is concluded that with low liquid filling, the impact load is greater near the free surface and the top of tank, and the impact position of the side bulkhead increases with the increasing of the frequency near the resonant frequency.

• Journal of the Korean Society of Clothing and Textiles
• /
• v.46 no.4
• /
• pp.565-582
• /
• 2022

In recent years, Jumchi-Hanji made of mulberry paper is used as a material for fashion items. This study examined the effect of the type of Choji method (Oebal-teugi or Ssangbal-teugi), layer number (one or two layers) and Jumchichigi time (20, 40, or 60 minutes) on the tensile, wet tensile, tearing and bursting strengths of Jumchi-Hanji. Jumchi-Hanjis used as test samples in this study were made from mulbery paper which was manufactured with either bleached or unbleached paper mulberry from Thailand. The results showed that Jumchi-Hanji made with two layers of mulberry papers had higher strength properties than Jumchi-Hanji made with only one layer. The strength properties of Jumchi-Hanji also increased with longer Jumchichigi time. Furthermore, this study confirmed that the effects of Jumchichigi time on Jumchi-Hanji strengths differed based on the type of Choji method, the layer number of mulberry papers used, and the specific strength property measured. Therefore, to guarantee the strength properties required by the application of Jumchi-Hanji paper as a fashion material, it is necessary to carefully consider the adequate Choji method and layer number to apply in the manufacture of Thai mulberry paper and the adequate duration time needed to perform Jumchichigi to Thai mulbery paper.

• Journal of the Korean Magnetics Society
• /
• v.15 no.5
• /
• pp.292-297
• /
• 2005

Steam generator of a nuclear power plant has important rolls for the heat transfer and the isolation of radioactive materials. So bursting of the steam generator tube is directly related to the accident of nuclear power plants. Incone1600 has been used for the steam generator tube material. The material shows non-magnetic and metallic properties, eddy current NDT method has been employed for defects detection. In this work, a differential type of eddy current probe was developed to improve resolution of defect detection. To verify properties of the developed differential type eddy current probe, we have made reference material with SUS304 which has similar magnetic and electrical properties of Inconel600. Using the developed differential type eddy current probe, we can detect defect size of 0.25 mm in diameter and 0.2 mm in depth (volume of $1{\times}10^{-3}\;mm^3$) with the reference material.

• Journal of the Computational Structural Engineering Institute of Korea
• /
• v.28 no.3
• /
• pp.317-324
• /
• 2015

The design of anchorage zone in a post-tensioned member has been started from the evaluation of the ultimate resisting capacity as well as the maximum bursting stress developed, and a lot of design codes including AASHTO and PTI describe their design equations to determine the bearing strength of concrete at the anchorage zone. However, these equations usually give conservative results because their derivation is based on the simple anchorage with a wide bearing plate in the surface without any additional consideration for the load transfer mechanism through transverse ribs on the anchorage. To assess the influence of geometric parameters related to the transverse ribs on the resisting capacity of anchorage block, experiments and analysis are conducted. After verifying the validity of numerical model conducted through correlation studies between experimental and analytical results, parametric studies with changes in the transverse ribs are followed and design recommendations for the anchorage block are suggested from the numerical results obtained.

• Journal of Korean Academy of Nursing
• /
• v.21 no.2
• /
• pp.230-246
• /
• 1991

Pain is a subjective and multidemensional concept. Therefore the patient's expression of pain have been referedl to the best believable indicator of pain condition but the support data obtained from the patient considered cultural difference is a deficient condition in determinded on the precise nursing diagnosis. The purpose of this reasearch was to understand multiple pain reponses in cultural difference and sensitivity, to encourage communication between medical teams, and to provide the foundation data of on data of precise nursing assessment for the patient in pain. The research problem was to grasp pain express pattern of Korean peptic ulcer patients. The subjects were 20 peptic ulcer patients in medical unit or OPD of twp university hospitals in Seoul. Data were collected from September 7th to 22nd, 1990 by intensive interviews. Interviews were done by the researcher and all were tape - recorded. The Data analysis was done by Phenomenological method from Van Kaam. Validity assured by confirmation of the internal consistency of the statements and catigory by nursing collegue in educational and clinicions in medical care. From the emic data, 96 descriptive statements were organized in 18 theme cluster. The results of study were summerized as follows. 1. Pain Express Pattern cluster of Peptic Ulcer Patients were “Pain as clogging”, “shallow pain”, “pain as pressing”, “nauseating pain”, “pain as smarting”, “pain as pulling”, “pain as pricking”, “pain as bursting”, “wrenching pain”, “excising pain”, “uncontrollable pain for mind and body”, “awakening pain”, “pain as hollowing” and the other cluster. As above mentioned, Pain Express Pattern of Peptic Ulcer Patient appeared diversely in verbal and they were propered to Korean culture. Therefore they will provide for the foundation data of precise nursing assessment.