• Journal of Radiation Protection and Research
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• v.1 no.1
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• pp.15-21
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• 1976

The present investigation was intended to study the state of Pm-147 in solution and its adsorbed state on membrane filters by varying the concentrations of Pm-147 solution and its pH. Also, the study on the coprecipitation of Pm-147 with $Fe(OH)_3$ was carried out by varying, amounts of $Fe(OH)_3$ and pH of the solution. The carrier-free Pm-147 exists in an ionic state of $Pm^{3+}$ in solution, and is adsorbed on membrane filter in filtration process. The adsorbed state of Pm-147 on the membrane filter shows various ionic state at a constant ionic strength of 0.1M NaCl, that is, $Pm^{3+}$ state exists until pH value of 5.0, then gradually $Pm(OH)^{2+}$ state appears between pH value of 5.0 to 6.0, and the state of $Pm(OH)_2^+$ and $Pm(OH)_3$ would be expected at the higher pH value of 6.0. Coprecipitation of Pm-147 on $Fe(OH)_3$ is an adsorption penomenon in an ionic state of $Pm^{3+}$ in acidic condition. At higher pH and larger amount of Fe carrier, the adsorbed state of Pm-147 shows $Pm(OH)^{2+}$ and $Pm(OH)_2^+$ state. As a results of the present studies, it is seen that the characteristic of carrier free radioisotopes is not due to the radioactivity, but due to the adsorption of ultramicroquantity of radioisopes. Therefore, the knowledge on the ultramicroquantity of radioisotopes could help for the solution of decontamination in handing and chemical procedure with radioisotopes.

• Journal of the Korea Concrete Institute
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• v.27 no.4
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• pp.411-418
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• 2015

This paper investigates the effects of fiber volume fraction and panel thickness on face damage characteristics of steel fiber-reinforced concrete (SFRC) under high-velocity globular projectile impact. The target specimens were prepared with $200{\times}200mm$ prismatic panels with thickness of 30 or 50 mm. All panels were subjected to the impact of a steel projectile with a diameter of 20 mm and velocity of 350 m/s. Specifically, this paper explores the correlation between mechanical properties and face damage characteristics of SFRC panels with different fiber volume fraction and panel thickness. The mechanical properties of SFRC considered in this study included compressive strength, modulus of rupture, and toughness. Test results indicated that the addition of steel fiber significantly improve the impact resistance of conventional concrete panel. The front face damage of SFRC panels decreased with increasing the compressive toughness and rear face damage decreased as the modulus of rupture and flexural toughness increased. To evaluate the damage response of SFRC panels under high-velocity impact, finite element analysis conducted using ABAQUS/Explicit commercial program. The predicted face damage of SFRC panels based on simulation shows well agreement with the experimental result in similar failure mode.

• Journal of the Korean Recycled Construction Resources Institute
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• v.7 no.4
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• pp.88-94
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• 2012

This study is conducted to utilize waste concrete powder made as a by-product manufacturing high quality recycled aggregate. The blaine fineness of the used waste concrete powder was 928 and $1,360cm^2/g$. As the main characteristic of waste concrete powder, it showed an angular type similar to cement, but hydrated products were attached on the surface of particles. In addition, the size of the particles of waste concrete powder was larger than OPC and in terms of chemical components it had higher $SiO_2$ contents. The viscosity of the paste that mixed waste concrete power decreased by 62% at the most, compared to the paste that only used OPC, and the final set time was delayed about two hours. As composition rates of waste concrete powder increased, the flow value decreased by 30% at the most according to the comparison with mortar that only used OPC, and sorptivity coefficients increased by 70%. The compressive strength of mortar decreased by 73% at the most as composition rates of waste concrete powder increased. According to the test results, it is desirable to use waste concrete powder by combining OPC appropriately(below 15%).

• Transactions of the Korean Society of Mechanical Engineers A
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• v.37 no.4
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• pp.483-490
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• 2013

In aluminum sheet metal forming, the conventional forming methods of T4 or T6 heat-treated sheets result in low formability and dimensional accuracy. This study suggests a new forming method for aluminum sheets called as hot forming quenching (HFQ) that solves the problems faced in the conventional method. HFQ combines the heat treatment and forming processes through the forming die during the quenching of a solid solution. To evaluate the application of HFQ to the sheet forming of aluminum, an Erichsen and V-bending test are performed in this study to measure the dimensional accuracy and formability, which are then compared with those of the conventional forming method. Furthermore, the strength and hardness of the products formed by HFQ are measured to confirm the degradation in mechanical properties compared with the conventional forming method, which shows the validity of the application of HFQ to aluminum sheet metal forming.

• Tunnel and Underground Space
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• v.19 no.3
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• pp.181-189
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• 2009

This study is to evaluate an effect of supports with respect to these supports after comparing the characteristic of support between rock bolt of a widely used type and spiral bolt of a new type. For these purposes, we performed pull-out test in laboratory about rock and spiral bolts in the case of cement-mortar grout curing periods, 7 and 28 days, then calculated pull-out load, displacement, external pressure, inner pressure and shear stress using data obtained from the results of pull-out test, respectively. In relation between pull-out load and displacement, displacement of spiral bolt is larger than one of rock bolt. It is considered that mechanical property of rock bolt is due to larger than one of spiral bolt. In addition, displacement of supports shows nearly same or decreasing with curing periods. We found that because adhesive force between supports and cement-mortar grout is increasing with compressive strength of grout according to curing periods. The inner pressure of spiral bolt is represented larger than one of rock bolt at a step of same pull-out load. It is suggested that spiral bolt is more stable than rock bolt, maintaining stability of ground or rock mass, when supports are installed in a ground or rock mass under the same condition. Putting together with above results, we can consider that spiral bolt as a new support on an aspect of pull-out load and inner pressure is larger than rock bolt in a ground or rock mass under the same condition. Moreover, spiral bolt is more effective support than rock bolt, considering an economical and constructive aspects of supports, as well as ground or rock stability before or after installing supports.

• Korean Journal of Oriental Medicine
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• v.16 no.3
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• pp.167-173
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• 2010

Objects : Glycine max Merr. (black bean), Triticum aestivum L. (wheat) and Oryza sativa L. (rice bran) have been widely used for treatment of relaxion of smooth muscle, gastrointestinal hemorrhage and alopecia in Korean Traditional Medicine. In this research, we examined the effect of the extracts, obtained from EtOH extracts of 3 kinds of traditional plants, on hair growing activity of the DP6 and C3H10T1 cell and physical properties. Materials and Methods : On the basis of previous studies, three traditional plants were selected and we extracted them with ethanol. We evaluated their hairy dermal papillar cell proliferation activity and mouse mesenchymal stem cell in vitro model. Also, 3 herbal extracts were added to the normal shampoo formulation in ranges of 0.1% and we validated tensile properties and physical changes using aged hair. In this research, we compared the tensile strength, shine and color appearance between the hair (general formulation) and the hair after applying shampoo with natural extracts. To analyze the luster and color image, we use the SAMBA hardware and software made by Bossa Nova Technologies. Results : In the comparative test for tensile characteristic between the hair treated general formulation(control) and the hair applying special formulation including 3 kinds of extracts, tensile distance and energy of the latter are larger than control on average. The shine and color appearance were also increased after using shampoo including natural extracts(shine : 10.9%, color appearance: 24.12%). We observed the enhancement of hair growth activity in the DP6 and C3H10T1 cell. Especially black bean extracts had the most powerful effect in the dermal papillar cell proliferation. Conclusion : These experiments suggest that extracts of Glycine max Merr. (black bean), Triticum aestivum L. (wheat) and Oryza sativa L. (rice bran) stimulate the hair growth activity and can improve physical activities of aged hair. Shampoo product, which contains 3 kinds of natural extracts, would be used for the treatment for aged hair.

• Science of Emotion and Sensibility
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• v.6 no.2
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• pp.29-35
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• 2003

In the oriental medicine, the illness of a human being is treated properly according to the strength and weakness of his/her physical constitution. In other words, the treatment principle of the oriental medicine is to balance the functions of the weak and strong inner parts of the physical constitution which can be classified into five characteristic elements: that is, the wood, fire, earth, mental, and water. An aroma therapy, one of traditional oriental medicine, uses pertinent perfumes to strengthen weak inner parts of the body, too. Although the remedy based on the five elements (in short, five element remedy) has revealed excellent clinical effects so far, it is still believed that the remedy is rather statistical and subjective than scientific. Thus, more systematic research needs to be done to prove it. In this paper, the correlation between perfume and physical constitutions has been formulated by grasping results of EEG through stimulation of lavender oil to both mental-type and fire-type persons. Also, the possibility of application for the five element remedy has been investigated. As a result, we found that the lavender oil helped to make strong gallbladder soften for fire-type individuals and to balance weak liver and strong gallbladder for mental-type persons. This agrees well with the results of the five element remedy practiced in the oriental medicine.

• Journal of Environmental Science International
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• v.19 no.8
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• pp.951-960
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• 2010

Sediment works as a resource for electric cells. This paper was designed in order to verify how sediment cells work with anodic material such as metal and carbon fiber. As known quite well, sediment under sea, rivers or streams provides a furbished environment for generating electrons via some electron transfer mechanism within specific microbial population or corrosive oxidation on the metal surfaces in the presence of oxygen or water molecules. We experimented with one type of sediment cell using different anodic material so as to attain prolonged, maximum electric power. Iron, Zinc, aluminum, copper, zinc/copper, and graphite felt were tested for anodes. Also, combined type of anodes-metal embedded in the graphite fiber matrix-was experimented for better performances. The results show that the combined type of anodes exhibited sustainable electricity production for ca. 600 h with max. $0.57\;W/m^2$ Al/Graphite. Meanwhile, graphite-only electrodes produced max. $0.11\;W/m^2$ along with quite stationary electric output, and for a zinc electrode, in which the electricity generated was not stable with time, therefore resulting in relatively sharp drop in that after 100 h or so, the maximum power density was $0.64\;W/m^2$. It was observed that the corrosive reaction rates in the metal electrodes might be varied, so that strength and stability in the electric performances(voltage and current density) could be affected by them. In addition to that, COD(chemical oxygen demand) of the sediment of the cell system was reduced by 17.5~36.7% in 600 h, which implied that the organic matter in the sediment would be partially converted into non-COD substances, that is, would suggest a way for decontamination of the aged, anaerobic sediment as well. The pH reduction for all electrodes could be a sign of organic acid production due to complicated chemical changes in the sediment.

• Journal of the Korean Recycled Construction Resources Institute
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• v.5 no.3
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• pp.282-289
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• 2017

The flexural behavior tests of UHPC segmental Box girder which has 160MPa compressive strength and 15.4m length were carried out. The test variables are area of prestressing wires, volume fraction of steel fibers and longitudinal reinforcing bars in upper flange and web. PS tendons which has 32 strands of 15.2mm diameter in lower flange, 24 strands and 14 strands in lower flange were arranged and volume fraction of 2%, 1.5% and 1.0% is used in box girder concrete. UHPFRC box girder which has 32 strands in lower flange showed the over reinforcement and brittle behavior. UHPFRC box girder which has 24 strands showed the similar peak load as 32 strands girder and ductile behavior as large deflection. UHPFRC box girder which has 14 strands showed half of the peak load of 24 strands box girder and ductile behavior. After the application of the formular for the reinforcement index to the behavior of the UHPFRC box girders, reinforcement index does not determine the characteristic of behavior of UHPFRC box girder exactly. So the index should consider the dimension precisely and modify the reference value corresponding to the 0.005 strain of the prestressing strands.

• Archives of design research
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• v.19 no.5 s.67
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• pp.171-180
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• 2006

The purpose of this study is to discover the plans for Yangyeongsi in Daegu, one of the most traditional streets and a tourist spot in South Korea, by preserving the historical place, reviving the historical characteristics and identity, revitalizing the uniqueness of the location, and developing the environment. This paper also illustrates the problems of the place through a investigation into its current state in order to promote the district and conduct a fundamental research framework to suggest future development methods and directions based on the problem statements. Daegu Yangyeongsi was chosen through frequency analysis and a survey asking for a suitable location and local characteristics to be developed for the local promotion through the field investigation of 158 cultural assets registered in the local government. This survey was conducted through the development process of the Regional Design Innovation Center to revitalize the traditional streets and places of interest. Through this investigation, 19 sites and traditional streets, which can be cultural resources for sightseeing and contribute to the local promotion, were extracted. Yangyeongsi, was selected from the finalists. The research methodology will be 1) to identify things for improvement potentiality through an in-depth analysis of Yangyeongsi, 2)to examine the mutual relationship between the revitalization strategy of Yangyeongsi and the city promotion strategy, and 3) to integrate the problems and improvements based on the results of the analysis. The notion of SWOT analysis synthetically considering the elements of opportunity and intimidation, strength and weakness to come up with the development direction was introduced to discover the local characteristics of Yangyeongsi and deduce the problem statement through the state analysis. Based on these results, the future development method and direction will be suggested in this paper through the revitalization study of Yangyeongsi.