• Animal cells and systems
• /
• v.3 no.1
• /
• pp.73-78
• /
• 1999

Although there are several methods for the preparation of mitochondrial DNA (mtDNA) from mammalian tissues, most are relatively long ultracentrifugation or manipulations by a small-scale method. We escribed a rapid method for large-scale extraction of mtDNA from human placental and horse liver tissues. The method is based on the preparation and homogenization of tissues, urification of crude mitochondria by differential centrifugations and isolation of mtDNA by alkaline Iysis. It was improved from Pre-existing methods by replacing some steps with simpler ones and discarding many others. This method gives a high yield of pure mtDNA(approximately 1-5mg from one placenta; ca. 400-600 g wet weight), depending on its sources (fresh tissue gave better results than frozen one). The resulting mtDNA indicated that this method can yield mtDNA in sufficient purity and quantity to identify the direct restriction analysis on agarose gel, random-primed labeling as a probe, and end labeling. Therefore, the method is ideal for obtaining good mtDNA samples to conduct routine restriction fragment length polymorphism (RFLP) analyses of natural populations for genetic studies.

• Nuclear Engineering and Technology
• /
• v.30 no.2
• /
• pp.83-90
• /
• 1998

To predict effects of seismic isolation, seismic isolation bearings were applied to the Wolsong reactor building and the analytical study was performed. For this study, the Wolsong reactor building was modeled using lumped masses and beam elements. Design Basis Earthquake with a ground acceleration of 0.2g was applied. And then, the behavior of the isolated structure was compared with that of the unisolated structure. The horizontal response acceleration at the top of the unisolated reactor building was 0.99g, while that of the isolated one was 0.14g(15% damping) and the acceleration response along the height of the structure was constant. The maximum displacement of the unisolated structure was 8.3mm, while that of the isolated structure was 66mm. The application of isolation bearings on the reactor building reduces seismic loads but increases the displacement of the structure on a large scale. Therefore, when using isolation bearings, the reactor building and BOP should be located on a common mat to cover the large displcement.

• Earthquakes and Structures
• /
• v.15 no.4
• /
• pp.411-417
• /
• 2018

To solve the seismic response problem of a vertical floating roof tank with base isolation, the floating roof is assumed to experience homogeneous rigid circular plate vibration, where the wave height of the vibration is linearly distributed along the radius, starting from the theory of fluid velocity potential; the potential function of the liquid movement and the corresponding theoretical expression of the base shear, overturning the moment, are then established. According to the equivalent principle of the shear and moment, a simplified mechanical model of a base isolation tank with a swinging effect is established, along with a motion equation of a vertical storage tank isolation system that considers the swinging effect based on the energy principle. At the same time, taking a 150,000 m 3 large-scale storage tank as an example, a numerical analysis of the dampening effect was conducted using a vibration mode decomposition response spectrum method, and a comparative analysis with a simplified mechanical model with no swinging effect was applied.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 1996.04a
• /
• pp.194-202
• /
• 1996

An approach to increase the seismic resistance of large structures is to reduce the seismic forces, to which structures are subjected by base isolation systems. The anti-seismic performance of base-isolated beatings has been verified experimentally by shaking table tests. However, it may be difficult to perform the tests for the full-scale beatings of base-isolated structures. Therefore, the test program was designed to evaluate the reliability and properties of the beatings under a range of loading conditions including axial stress, loading frequency and direction, and temperature. The effects of scale were also evaluated by comparing the results of the 1/4-scale beatings with those from the full-scale bearings, and the ultimate behavior of both types of bearings with evaluated through a series of roll-out tests. This report draws comparisons among the different tests and bearings to determine the importance of various factors including load history, axial stress, and frequency. Comparisons between the 1/4-scale bearings were difficult because of the scaling effects in manufacturing and thermal radiation, but qualitative results from the 1/4-scale bearings can certainly be extrapolated the full-scale bearings.

• International Journal of High-Rise Buildings
• /
• v.12 no.1
• /
• pp.93-105
• /
• 2023

Seismic isolation and vibration control techniques have been developed and put into practical use by challenging researchers and engineers worldwide since the latter half of the 20th century, and after more than 40 years, they are now used in thousands of buildings, private residences, highways in many seismic areas in the world. Seismic isolation and vibration control structures can keep the structures undamaged even in a major earthquake and realize continuous occupancy. This performance has come to be recognized not only by engineers but also by ordinary people, becoming indispensable for the formation of a resilient society. However, the dynamic characteristics of seismically isolated bearings, the key elements, are highly dependent on the size effect and rate-of-loading, especially under extreme loading conditions. Therefore, confirming the actual properties and performance of these bearings with full-scale specimens under prescribed dynamic loading protocols is essential. The number of testing facilities with such capacity is still limited and even though the existing labs in the US, China, Taiwan, Italy, etc. are conducting these tests, their dynamic loading test setups are subjected to friction generated by the large vertical loads and inertial force of the heavy table which affect the accuracy of measured forces. To solve this problem, the authors have proposed a direct reaction force measuring system that can eliminate the effects of friction and inertia forces, and a seismic isolation testing facility with the proposed system (E-isolation) will be completed on March 2023 in Japan. This test facility is designed to conduct not only dynamic loading tests of seismic isolation bearings and dampers but also to perform hybrid simulations of seismically isolated structures. In this paper, design details and the realization of this system into an actual dynamic testing facility are presented and the outcomes are discussed.

• KSBB Journal
• /
• v.9 no.4
• /
• pp.385-394
• /
• 1994

Large scale purification to get antifungal antibiotic KRF-001 of 90% purity, was investigated using preparative HPLC. Crude KRF-001 was purified by XAD-7 adsorption chromatography, acid precipitation and microfiltration. Microfiltration was the most effective isolation method of crude KRF-001. The purification methods using C18 chromatography was convenient compared with the conventional methods. Delta PAK C18 column and Bonda PAK C18 column were adapted large scale purification of KRF-001. Gradient system of prep HPLC using Delta PAK C18 column was more effective. With these conditions, final recovery of KRF-001 yielded 77%.

• Journal of Applied Biological Chemistry
• /
• v.43 no.3
• /
• pp.176-179
• /
• 2000

Nonpolar taxoides extracted from a large-scale cell culture of Taxus chinensis were isolated through the normal and reverse phase column chromatographies, and their compounds were identified via NMR spectroscopy. The complete separation method was systematically established and described. In dichloromethane, dissolved paclitaxel and other taxoids with hexane were precipitated during the purification of paclitaxel from the plant cell culture of T. chinensis through a large-scale process while the relatively nonpolar taxane derivatives remained dissolved in the hexane phase. 13-Deoxy baccatin III (I), baccatin VI (II), taxchinin I (III), $2{\alpha}$, $5{\alpha}$, $10{\beta}$, $14{\beta}$-tetraacetoxy-4(20), 11-taxadiene(IV), 1-deoxy baccatinVI(V), and taxayuntin C (VI) were isolated through column chromatography and identified via NMR spectroscopy. Compounds I and IV were found to the major components, aside from paclitaxel, in the plant cell culture of T. chinensis. The concentrations of I and IV were compared with the that concentration of the paclitaxel in each of plant cell culture. The possible applications of compounds I, II, IV, and V were discussed.

• Archives of Pharmacal Research
• /
• v.5 no.1
• /
• pp.7-12
• /
• 1982

Ginsenosides Rb1, Rb2, Rc, Rd, Re, Rf and Rg1 were effectively isolated from ginseng root by preparative liquid chromatography (LC) on two PrepPAK-500/c18 cartridges in series and semipreparative LC on a .mu. Bondapak cabohydrate analysis column, a .mu.Bondapak C18 column or a .mu. Porasil column. The identities of the isolated ginsenosides were confirmed by analytical high-performance liquid chromatography (HPLC) and infrared spectrophotometry. By this method large scale isolation of pure ginsenosides was efficiently accomplished.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 2001.11a
• /
• pp.247-251
• /
• 2001

Nowadays, base isolation systems such as lead-rubber bearing, elastomer bearing and sliding bearing have been installed to the various structures to prevent the disaster from seismic. The performance of base isolation system have been well proved by model-scale experiments and numerical analysis. However. the seismic response data measured at real large base-isolated structures is still insufficient. This paper presents a seismic monitoring system, acquiring real-time acceleration signals up to 32 channels, displaying time history and spectrum of the signals, storing the acquired data at a PC hard disk, and replaying the saved data. Moreover, the system can be operated without any limitation for monitoring period by automatic management of stored data file. The developed system has been installed at a real base-isolated building using lead-rubber bearings and we expect its seismic response data with ground motion signal can be well licquired in case of earthquake occurrence.

• The Transactions of the Korean Institute of Electrical Engineers C
• /
• v.52 no.10
• /
• pp.441-446
• /
• 2003

The chemical mechanical polishing (CMP) process is now widely employed in the ultra large scale integrated (ULSI) semiconductor fabrication. Especially, shallow trench isolation (STI) has become a key isolation scheme for sub-0.13/0.10${\mu}{\textrm}{m}$ CMOS technology. The most important issues of STI-CMP is to decrease the various defects such as nitride residue, dishing, and tom oxide. To solve these problems, in this paper, we studied the planarization characteristics using slurry additive with the high selectivity between $SiO_2$ and $Si_3$$N_4$ films for the purpose of process simplification and in-situ end point detection. As our experimental results, it was possible to achieve a global planarization and STI-CMP process could be dramatically simplified. Also, we estimated the reliability through the repeated tests with the optimized process conditions in order to identify the reproducibility of STI-CMP process.