• Title/Summary/Keyword: Shake test

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Seismic analysis of turbo machinery foundation: Shaking table test and computational modeling

  • Tripathy, Sungyani;Desai, Atul K
    • Earthquakes and Structures
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    • v.12 no.6
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    • pp.629-641
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    • 2017
  • Foundation plays a significant role in safe and efficient turbo machinery operation. Turbo machineries generate harmonic load on the foundation due to their high speed rotating motion which causes vibration in the machinery, foundation and soil beneath the foundation. The problems caused by vibration get multiplied if the soil is poor. An improperly designed machine foundation increases the vibration and reduces machinery health leading to frequent maintenance. Hence it is very important to study the soil structure interaction and effect of machine vibration on the foundation during turbo machinery operation in the design stage itself. The present work studies the effect of harmonic load due to machine operation along with earthquake loading on the frame foundation for poor soil conditions. Various alternative foundations like rafts, barrette, batter pile and combinations of barrettes with batter pile are analyzed to study the improvements in the vibration patterns. Detailed computational analysis was carried out in SAP 2000 software; the numerical model was analyzed and compared with the shaking table experiment results. The numerical results are found to be closely matching with the experimental data which confirms the accuracy of the numerical model predictions. Both shake table and SAP 2000 results reveal that combination of barrette and batter piles with raft are best suitable for poor soil conditions because it reduces the displacement at top deck, bending moment and horizontal displacement of pile and thereby making the foundation more stable under seismic loading.

Seismic performance of concrete frame structures reinforced with superelastic shape memory alloys

  • Alam, M. Shahria;Nehdi, Moncef;Youssef, Maged A.
    • Smart Structures and Systems
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    • v.5 no.5
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    • pp.565-585
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    • 2009
  • Superelastic Shape Memory Alloys (SMAs) are gaining acceptance for use as reinforcing bars in concrete structures. The seismic behaviour of concrete frames reinforced with SMAs is being assessed in this study. Two eight-storey concrete frames, one of which is reinforced with regular steel and the other with SMAs at the plastic hinge regions of beams and regular steel elsewhere, are designed and analyzed using 10 different ground motion records. Both frames are located in the highly seismic region of Western Canada and are designed and detailed according to current seismic design standards. The validation of a finite element (FE) program that was conducted previously at the element level is extended to the structure level in this paper using the results of a shake table test of a three-storey moment resisting steel RC frame. The ten accelerograms that are chosen for analyzing the designed RC frames are scaled based on the spectral ordinate at the fundamental periods of the frames. The behaviour of both frames under scaled seismic excitations is compared in terms of maximum inter-storey drift, top-storey drift, inter-storey residual drift, and residual top-storey drift. The results show that SMA-RC frames are able to recover most of its post-yield deformation, even after a strong earthquake.

Experimental identification of the six DOF C.G.S., Algeria, shaking table system

  • Airouche, Abdelhalim;Bechtoula, Hakim;Aknouche, Hassan;Thoen, Bradford K.;Benouar, Djillali
    • Smart Structures and Systems
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    • v.13 no.1
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    • pp.137-154
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    • 2014
  • Servohydraulic shaking tables are being increasingly used in the field of earthquake engineering. They play a critical role in the advancement of the research state and remain one of the valuable tools for seismic testing. Recently, the National Earthquake Engineering Research Center, CGS, has acquired a 6.1m x 6.1 m shaking table system which has a six degree-of-freedom testing capability. The maximum specimen mass that can be tested on the shaking table is 60 t. This facility is designed specially for testing a complete civil engineering structures, substructures and structural elements up to collapse or ultimate limit states. It can also be used for qualification testing of industrial equipments. The current paper presents the main findings of the experimental shake-down characterization testing of the CGS shaking table. The test program carried out in this study included random white noise and harmonic tests. These tests were performed along each of the six degrees of freedom, three translations and three rotations. This investigation provides fundamental parameters that are required and essential while elaborating a realistic model of the CGS shaking table. Also presented in this paper, is the numerical model of the shaking table that was established and validated.

A Study on the Antimicrobial Finishing of Artificial Suede by Allylamine Copolymers (Allylamine계 항균제를 이용한 인조스웨드 직물의 항균코팅에 관한 연구)

  • 김윤정;이종우;윤남식
    • Textile Coloration and Finishing
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    • v.12 no.1
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    • pp.61-67
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    • 2000
  • This study was carried out to develope antimicrobial artificial suede by coating with water soluble polyurethane resin and the copolymer of N,N'-dialkyl-N,N'-dialkyl ammonium chloride (DADAAC) and acrylamide as a antimicrobial additve. The copolymer of DADAAC and acrylamide was synthesized by free radical initiation and intra-intermolecular propagation, and the prepared copolymers had sufficient compatibility with water soluble polyurethane resin. The MIC values of the prepared copolymers and antimicrobial characteristics of the artificial suede coated by polyurethane were evaluated. With the increase in the proportion of DADAAC, which is antimicrobially active part in the DADAAC/acrylamide copolymers, the MIC value becomes lower. The MIC value of DADAAC-AA (1 : 1) copolymer is below 30 ppm against S. aureus, and below 90 ppm against K pneumoniae. The artificial suede coated by water soluble polyurethane resin with 1.0% owl concentration of DADAAC/acrylamide copolymer has good antimicrobial fastness as to show colony reduction of above 90% and 80% against S. aureus and K. pneumoniae respectively in the shake flask test after 10 times of washing, and above 95% and 85% after 10 times of dry-cleaning. The elastic recovery of coated suede fabric is not affected up to 1.0% owf concentration of DADAAC-AA copolymer in the polyurethane coating.

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A study on the Application of Electromagnetic Type HMD for Vibration Control of Structure (구조물 진동제어를 위한 전자석구동 HMD의 응용에 관한 연구)

  • Choi, Hyun;Jeoung, Jeoung-Kyo;Kim, Doo-Hoon;Lee, Sang-Jo
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2000.06a
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    • pp.280-285
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    • 2000
  • With recent development of technology of high stiffness material and the structural design, the construction of high rise structures such as tall building, tower has increased. The more flexible and slender structure is vulnerable to the internal and external dynamic loads induced by earthquake, wind and traffic load. There have been great effort and many researches to minimize the influence of dynamic loads on the structure. The traditional and stable method, the application of the passive damper, is not able to comply with various dynamic loads, while the mass damper which active control technology is integrated can effectively comply with load types. Therefore, the application of active control of huge structures with AMD(Active mass damper) or HMD(Hybrid Mass damper) is increasing. Up to now, most of actuators are servomotor and hydraulic actuator. But it is known that the electromagnetic actuator applies non contacting control force, which makes the control system easier with no characteristic change depending on time. In this paper, Hybrid mass damper with electromagnetic actuator was designed and applied to building scaled structure. The performance of designed HMD tested by shake table test is included.

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Seismic analysis of a masonry cross vault through shaking table tests: the case study of the Dey Mosque in Algiers

  • Rossi, Michela;Calderini, Chiara;Roselli, Ivan;Mongelli, Marialuisa;De Canio, Gerardo;Lagomarsino, Sergio
    • Earthquakes and Structures
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    • v.18 no.1
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    • pp.57-72
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    • 2020
  • This paper presents the results of a monodirectional shaking table test on a full-scale unreinforced masonry cross vault characterized by asymmetric boundary conditions. The specimen represents a vault of the mosque of Dey in Algiers (Algeria), reproducing in detail the mechanical characteristics of masonry, and the constructive details including the presence of some peculiar wooden logs placed within the vault's abutments. The vault was tested with and without the presence of two steel bars which connect two opposite sides of the vault. The dynamic behaviour of both the vault's configurations were studied by using an incremental dynamic analysis up to the collapse of the vault without the steel bars. The use of an innovative high-resolution 3D optical system allowed measure displacement data of the cross vault during the shake table tests. The experimental results were analysed in terms of evolution of damage mechanisms, and in-plane and out-of-plane deformations. Moreover, the dynamic properties of the structure were investigated by means of an experimental modal analysis.

Strain Improvement for Enhanced Production of Streptokinase and Streptodornase in Streptococcus sp.

  • HYUN, HYUNG-HWAN;YOON-BUM LEE;KYUNG-HWA SONG;JI-YOUNG JEON;HYUNE-HWAN LEE
    • Journal of Microbiology and Biotechnology
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    • v.7 no.2
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    • pp.101-106
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    • 1997
  • Strain improvement for the enhanced production of streptokinase and streptodornase in Streptococcus sp. ATCC 12449 was performed. Strain UB111, a hyperproductive mutant which was isolated by use of nitrosoguanidine and selection of colonies with large clear zones on DNase test agar plates supplemented with $1{\%}$ glucose and $0.5{\%}$ ammonium chloride, produced about 3 fold more streptokinase and streptodornase than the wild type when tested in shake flask fermentations. The enhanced production of both streptokinase and streptodornase was achieved by cultivating the mutant in a pH-controlled fermentor containing fermentation medium enriched with yeast extract ($2.1{\%}$). Under these conditions, the mutant produced 7300 units/ml of streptokinase and 800 units/ml of streptodornase.

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Studies on Constituents of Kotean Basidiomycetes (L) Antitmor Components Extracted from Cultured Mycelia of Several Basidiomycetes

  • Kim, Byong-Kak;Choi, Eung-Chil;Chung, Kyeong-Soo;Park, Hee-Ju;Kim, Hye-Ryoung;Kim, Yang-Sup;Park, Yong-Hwan;Shim, Mi-Ja
    • Archives of Pharmacal Research
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    • v.6 no.2
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    • pp.141-142
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    • 1983
  • To find anititumor metabolites in Korean basidiomycetes, the shake-cultured mycelia of eight of the higher fungi were extracted with hot water and the extracts, after being partially purified, were subjected to in vivo antitumor test. When administered i. p. at the dose of 30mg/kg/day for ten consecutive days into the female ICR mice, which had been implanted with $1{\times}10^{6}$ / cells of sarcoma 180 twenty four hours before the first injection, the extracts of Agaricus campestris, Lyophyllum decastes, Lyophyllum ulmarium, Armillaria Tabescence and Calvatia exipuliformis respectively showed inhibition ratios of 64.1%, 65.45, 60.-%, 53.0 and 49.3%. These five species were selected for further study, whereas the extracts of Phallus impudicus, Coprinus comatus and Pholiota squarrosa whih showed the inhibition ratios of 31.2%, 33.5% and 19.0% were discontinued.

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Morphine dependence is attenuated by red ginseng extract and ginsenosides Rh2, Rg3, and compound K

  • Yayeh, Taddesse;Yun, Kyunghwa;Jang, Soyong;Oh, Seikwan
    • Journal of Ginseng Research
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    • v.40 no.4
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    • pp.445-452
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    • 2016
  • Background: Red ginseng and ginsenosides have shown plethoric effects against various ailments. However, little is known regarding the effect of red ginseng on morphine-induced dependence and tolerance. We therefore investigated the effect of red ginseng extract (RGE) and biotransformed ginsenosides Rh2, Rg3, and compound K on morphine-induced dependence in mice and rats. Methods: While mice were pretreated with RGE and then morphine was injected intraperitoneally, rats were infused with ginsenosides and morphine intracranially for 7 days. Naloxone-induced morphine withdrawal syndrome was estimated and conditioned place preference test was performed for physical and psychological dependence, respectively. Western blotting was used to measure protein expressions. Results: Whereas RGE inhibited the number of naloxone-precipitated jumps and reduced conditioned place preference score, it restored the level of glutathione in mice. Likewise, ginsenosides Rh2, Rg3, and compound K attenuated morphine-dependent behavioral patterns such as teeth chattering, grooming, wet-dog shake, and escape behavior in rats. Moreover, activated N-methyl-D-aspartate acid receptor subunit 1 and extracellular signal-regulated kinase in the frontal cortex of rats, and cultured cortical neurons from mice were downregulated by ginsenosides Rh2, Rg3, and compound K despite their differential effects. Conclusion: RGE and biotransformed ginsenosides could be considered as potential therapeutic agents against morphine-induced dependence.

Seismic response of bridge pier supported on rocking shallow foundation

  • Deviprasad, B.S.;Dodagoudar, G.R.
    • Geomechanics and Engineering
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    • v.21 no.1
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    • pp.73-84
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    • 2020
  • In the seismic design of bridges, formation of plastic hinges plays an important role in the dissipation of seismic energy. In the case of conventional fixed-base bridges, the plastic hinges are allowed to form in the superstructure alone. During seismic event, such bridges may be safe from collapse but the superstructure undergoes significant plastic deformations. As an alternative design approach, the plastic hinges are guided to form in the soil thereby utilizing the inevitable yielding of the soil. Rocking foundations work on this concept. The formation of plastic hinges in the soil reduces the load and displacement demands on the superstructure. This study aims at evaluating the seismic response of bridge pier supported on rocking shallow foundation. For this purpose, a BNWF model is implemented in OpenSees platform. The capability of the BNWF model to capture the SSI effects, nonlinear behavior and dynamic loading response are validated using the centrifuge and shake table test results. A comparative study is performed between the seismic response of the bridge pier supported on the rocking shallow foundation and conventional fixed-base foundation. Results of the study have established the beneficial effects of using the rocking shallow foundation for the seismic response analysis of the bridge piers.