• Korean Chemical Engineering Research
• /
• v.58 no.2
• /
• pp.301-306
• /
• 2020

We investigated the individual biosorption removal of lead, copper, and nickel ions from aqueous solutions using Chara sp. algae powder in a batch mode. The impact of several parameters, such as initial concentration of the metal ions, contacting time, sorbent dose, and pH on the removal efficiency, was investigated. The maximum removal efficiency at optimum conditions was found to be 98% for Pb(II) at pH = 4, 90% for Cu(II) at pH = 5, and 80% for Ni(II) at pH = 5. The isotherm study was done under the optimum conditions for each metal by applying the experimental results onto the well-known Freundlich and Langmuir models. The results show that the Langmuir is better in describing the isotherm adsorption of Pb(II) and Ni(II), while the Freundlich is a better fit in the case of Cu(II). Similarly, a kinetic study was performed by using the pseudo-first and second-order equations. Our results show that the pseudo-second-order is better in representing the kinetic adsorption of the three metal ions.

• Animal cells and systems
• /
• v.4 no.3
• /
• pp.201-214
• /
• 2000

Two quite different types of plant cells are analysed with regard to transduction of the gravity stimulus: (i) Unicellular rhizoids and protonemata of characean green algae; these are tube-like, tip-growing cells which respond to the direction of gravity. (ii) Columella cells located in the center of the root cap of higher plants; these cells (statocytes) perceive gravity. The two cell types contain heavy particles or organelles (sataoliths) which sediment in the field of gravity, thereby inducing the graviresponse. Both cell types were studied under microgravity conditions ($10^{-4}$/ g) in sounding rockets or spacelabs. From video microscopy of living Chara cells and different experiments with both cell types it was concluded that the position of statoliths depends on the balance of two forces, i.e. the gravitational force and the counteracting force mediated by actin microfilaments. The actomyosin system may be the missing link between the gravity-dependent movement of statoliths and the gravity receptor(s); it may also function as an amplifier.

• Journal of Digital Contents Society
• /
• v.16 no.5
• /
• pp.849-869
• /
• 2015

Since South Korean government pushed ahead with decentralization system in 1990s, each local government has developed 'local government's character' so that communication between local residents and between local government and residents could be going well for rural solidarity. Local governments have designed their sole symbolic characters, applied the characters to local specialities and tourist goods, and used the designed characters for the promotion of area. There is no difference between South Korea and Japan in the function of local government's character as above-mentioned details. However, 'Yuru-chara' characters which are designed by local governments in Japan are rising dramatically in the field of Japanese major characters. 'Yuru-chara' characters' name awareness is expanded to the entire area of Japan as well as the designed area. A remarkable difference in how to promote character rather than character design caused such a successful outcome. The local governments in Japan carried out a promotion for local residents in various, friendly, and active ways, utilized local government's character as a way to publicize the image of area, and turned the character into products to bring additional effects. In the above process, there was a remarkable difference between Japan and South Korea. The purpose of this study was to research detail data related to the characters of the local governments in Japan, to analyze the promotion of the characters, and to suggest a strategy for promoting the characters of the local governments in South Korea.

• Transactions of the Korean Society of Automotive Engineers
• /
• v.6 no.5
• /
• pp.75-85
• /
• 1998

This paper presents the procedures and technique of the decision on the decision on the mount in a diesel engine development newly. To assess the vibration chara- cteristics of the engine plus transmission, their inertia moments are calculated for three engine versions. i.e., NA(Naturally Aspirated), TC(Turbocharged) and TCI(Turbocharged and Intercooled). These data are used to determine the mount layout and stiffness values affecting the noise quality of an engine as well as a vehicle. The main purpose of this paper is to design the mount rubber having the optimal stiffness characteristics through the investigation of the calculation results and the mount conditions when an engine is installed in a vehicle using the existing engine mount room. Thus, this paper describes the optimal mount positions, rubber stiffnesses, natural frequency, mode shapes and so on using ADAMS program to apply the newly developed engines to three different vehicles.

• Proceedings of the IEEK Conference
• /
• 2002.06b
• /
• pp.217-220
• /
• 2002

In this paper, we have investigated electronical chara-cteristics of power LDMOSFETS having different ex-tended gate lengths(1.B${\mu}{\textrm}{m}$, 2.4${\mu}{\textrm}{m}$, 3.O${\mu}{\textrm}{m}$) in the temperature range of 300k-500K. The results of this study indicate that on-resistance, breakdown voltage increase with temperature. and drain current, threshold voltage, transconductance decrease with temperature. Particular the facts, we observed that Le is the more increase, on-resistance is the more decrease. because every conditions are fixed normal states, only change the Le. As a result, Ron/BV, known for a figure of merit of power device, increase with temperature.

• Bulletin of the Korean Space Science Society
• /
• 2010.04a
• /
• pp.35.1-35.1
• /
• 2010

Using the spectroscopic analysis and the theoretical modeling, physical properties of the nearby astrometric binary $\mu$ Cas have been determined. In spite of the well-defined parallax and astrometric orbit, there has been a chronic mass ratio problem between components. Recently, the radius of the primary component has been detected from the optical interferometric observation of the CHARA array. Using the high resolution spectroscopic analysis, we found that $\mu$ Cas have $\alpha$-enhanced chemical composition with respect to the scaled solar abundance by a factor of two. Combining our abundance analysis with recently determined physical properties, the consistent models for $\mu$ Cas have been constructed within the frame work of standard stellar theory. Through a statistical minimization between theoretical model grids, a reliable set of physical dimensions has been defined. Furthermore, the mode oscillation frequency of the best model has been calculated.

• Proceedings of the KSRS Conference
• /
• 2003.11a
• /
• pp.513-515
• /
• 2003

COMS(Communication, Ocean and Meteorological Satellite), planned for launch in 2008, will be the first Korean ocean-meteorological geostationary satellite to provide capabilities for monitoring weather and ocean. Under the direction of Korean government, KARI(Korea Aerospace Research Institute) has the overall responsibility of COMS development project. The main development project was started in September 2003. In this paper, the overview of COMS development project and the conceptual design of the meteorological data service are introduced.

• Journal of the Korean Geotechnical Society
• /
• v.30 no.10
• /
• pp.67-80
• /
• 2014

The thickness of permafrost in Eastern Siberia is from 200 to 500 meters. The seasonally frozen layer can vary from 0 to 4m depending on ground temperature and its location. The shear wave velocity varies from 80m/s in summer to 1500m/s in winter depending on soil type. When melted, large impedence will occur due to the difference between the shear wave velocity of seasonally frozen soil and that of permafrost layer. Large displacement may occur at the boundary of the melted and the frozen layer, and this phenomenon should be considered in a seismic design. In this research, one-dimensional equivalent linear analyses were performed to investigate the effects of the seasonally frozen layer on ground amplification characteristics. Soil profiles of Yakutsk and Chara in Eastern Siberia were selected from geotechnical reports. 20 recorded ground motions were used to evaluate the effect of input motions. As the thickness of seasonally frozen layer and the difference in the shear wave velocity increases, the amplification is shown to increase. Peat, very soft organic soil widely distributed throughout Eastern Siberia, is shown to cause significant ground motion amplification. It is therefore recommended to account for its influence on propagated motion.

• The Journal of the Korea Contents Association
• /
• v.12 no.3
• /
• pp.470-479
• /
• 2012

This study was designed to investigate and analyze children's preference on animation characters according to age and gender of the subjects, by surveying 255 children aged from 3 to 5. The animation characters were represented in pictures, and the reasons of preference were collected through individual interview with the children. The $x^2$ verification of SPSS 18.0 Window statistic program was used to verify the difference in preference. As a result, children aged from 3 to 5 showed higher preference on animations produced in foreign countries than the ones produced in Korea, as Korean animations and foreign-country animations had preference rate of 35.7% and 64.3%, and Korean characters and foreign-country characters had preference rate of 22.4% and 77.6% respectively. Depending on the age of children, there was significant difference among animation characters that the children prefer ($x^2=302.474^{***}$, P<.001), and it was shown that children at the age of 3 showed preference on 'Pororo' of Pororo the Little Penguin, children at the age of 4 on 'Tayo' of Tayo the Little Bus and 'Amu' of Shugo Chara, and children at the age of 5 on 'Shin Chan' of Crayon Shin Chan. It was also revealed that there was significant difference among animation characters according to the gender of children ($x^2=120.864^{***}$, P<.001); boys preferred 'Pororo' of Pororo the Little Penguin the most, followed by 'Doraemon' of Doraemon, 'Thomas' of Thomas and Friends and 'Tayo' of Tayo the Little Bus, and girls preferred 'Pororo' of Pororo the Little Penguin the most, followed by 'Apple' of Little Princess, 'Amu' of Shugo Chara and 'Loopy' of Pororo the Little Penguin. Through this study, it is hoped that the development of children animation would advance further, and that this study could be used as the preliminary resource.

• Korean Journal of Weed Science
• /
• v.12 no.4
• /
• pp.352-361
• /
• 1992

The identification of the stoneworts, euglenoids and diatoms which were collected from paddy rice fields was conducted in 1991. In the division Charophyta. Chara braunii Gmelin was identified. Two species in the genus Euglena, 1 species in the genus Phacus and 3 species in the genus Trachelomonas were identified in the division Eugrenophyta. The total number of species identified as the diatoms was 21 species in 6 families including 5 species in the Coscinodiscaceae, 3 species in the Fragilariaceae, 1 species in the Achanthaceae, 9 species in the Naviculaceae, 1 species in the Cymbellaceae and 2 species in the Nitzschiaceae. Generally, a concentrated population of Eulgena on paddy water caused green water blooms, but the color of the water blooms at the cyst formation stage was changed to red. In soil flakes with brown tint, the diatoms belonging to the order Pennales were numerous in microscopic view.