• Title/Summary/Keyword: isolation techniques

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The NF-l6D VISTA Simulation System

  • Siouris, George M.
    • Transactions on Control, Automation and Systems Engineering
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    • v.4 no.2
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    • pp.114-123
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    • 2002
  • Called VISTA (Variable-stability In-flight Simulator Test Aircraft), the one-of-a-kind NF-l6D has a simulation system that can mimic several aircraft. Though housed in an F-l6 Fighting Falcon airframe, VISTA can also act like the F-15 Eagle or the Navy's F-14 Tomcat. More importantly, such flexibility allows for improved training and consolidation of some sorties. Consequently USAF Test Pilot School students will have an opportunity to learn how to test future integrated cockpits. In this paper we will use the multiple model adaptive estimation (MMAE) and the multiple model adaptive controller (MMAC) techniques to model the aircraft's flight control system containing the longitudinal and lateral-directional axes. Single and dual actuator and sensor failures will also be included in the simulation. White Gaussian noise will be included to simulate the effects of atmospheric disturbances.

Production of Arachidonic Acid by Mortierella Fungi

  • Higashiyama, Kenichi;Fujikawa, Shigeaki;Park, Enoch Y.;Shimizu , Sakazu
    • Biotechnology and Bioprocess Engineering:BBE
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    • v.7 no.5
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    • pp.252-262
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    • 2002
  • The growing interest in the application of arachidonic acid (ARA) in various fields of health and dietary requirements has elicited much attention on the industrial production of ARA-containing oil by the cultivation of Mortierella fungi. For the industrial production of ARA, various studies, such as isolation of a high-potential strain and optimization of culture conditions, have been conducted. Studies including the investigation of morphology are important because ARA is accumulated in the mycelia, and thus cultivation with high biomass concentration is essential for obtaining a high ARA yield. Combining the results derived from various studies, a high ARA yield was attained in an industrial fermentor. These ARA production techniques are applicable to the production of other polyunsaturated fatty acids (PUFAs), and will contribute to the improvement of fermentation technology especially in the field of fungal cultivation.

Dynamic Property Evaluation of Lead Rubber Bearing by Shear Loading (적층고무베어링의 동적 특성평가)

  • 이경진;김갑순;강태경;서용표;이종림
    • Proceedings of the Earthquake Engineering Society of Korea Conference
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    • 2002.03a
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    • pp.367-372
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    • 2002
  • In these days, The base isolation system is often used to improve the seismic capacity of the structures instead of conventional techniques of strengthening the structural members. The purpose of this study is to evaluate dynamic properties and mechanical characteristics of the 10tonf-LRB(Lead-Rubber Bearing). Experimental studies were performed to obtain the hysteretic behavior, effective shear stiffness( $K_{eff}$), equivalent damping( $H_{eq}$ ), capacity of energy dissipation( $W_{D}$) of six 10tonf-LRB. Especially, in this study, the response of the LRB for high loading frequency(0.5Hz~3.0Hz) was estimated. The effective shear stiffness of the LRB decreases and the capacity of energy dissipation increases as the shear strain amplitude increases. But the shear behavior of the LRB is not affected sensitively by loading frequency.y.y.

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Chemical Constituents and Biological Activities of Cichorium intybus L.

  • El-Lakany, Abdalla M.;Aboul-Ela, Maha A.;Abdul-Ghani, Mohamed M.;Mekky, Hattem
    • Natural Product Sciences
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    • v.10 no.2
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    • pp.69-73
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    • 2004
  • Continuation of a phytochemical study of Cichorium intybus L. (Astraceae) growing in Egypt, resulted in the isolation and identification of a new sesquiterpene lactone 3,4-dihydrolactucin, in addition to the eight known compounds; kaempferol, isoscutellarin, cichoriin, umbelliferone, lupeol, lupeol acetate, ${\beta}-sitosterol$, and ${\beta}-sitosterol-3-O-glucoside$. Chemical structures of the isolated compounds were assigned based on different physical, chemical, and spectroscopic techniques including IR, UV, MS, 1D- and 2D-NMR spectra. Furthermore, the antimicrobial, and spasmogenic activities of some fractions and isolates were also assessed.

Chemical constituents and antihepatotoxic effect of the berries of Juniperus Phoenicea Part II

  • Aboul-Ela, Maha;El-Shaer, Nagwa;El-Azim, Tarek Abd
    • Natural Product Sciences
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    • v.11 no.4
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    • pp.240-247
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    • 2005
  • Phytochemical investigation of the berries of Juniperus phoenicea led to the isolation of 4 compounds, namely; scutellarin, isoscutellarin, shikimic acid and the new palmitoyl lactone derivative 16-hydroxy palmitic-1,16-olide. This is the first report for the occurrence of these compounds in the species grown in Libya. The identification of the isolated compounds was based on the application of different spectroscopic techniques. In addition, the antihepatotoxic effect of the aqueous decoction of the berries was investigated.

A New Pyranoxanthone Inophyllin B from Calophyllum inophyllum

  • Ee, G.C.L.;Kua, A.S.M.;Cheow, Y.L.;Lim, C.K.;Jong, V.;Rahmani, M.
    • Natural Product Sciences
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    • v.10 no.5
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    • pp.220-222
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    • 2004
  • A new prenylated pyranoxanthone, inophyllin B (1), was isolated from the roots of Calophyllum inophyllum (Guttiferae). Together with this compound was also isolated the known pyranoxanthone brasilixanthone B (2) and two common triterpenes friedelin (3) and sitosterol (4). Structural elucidations of these compounds were achieved through $^1H,\;^{13}C$, DEPT, COSY, HSQC and HMBC experiments. The molecular mass was determined using MS techniques. The crude extract indicated weak toxicity to the larvae of Aedes aegypti. We report here the isolation, structural elucidation and bioassay data for Inophyllin B and brasilixanthone B.

Superoxide Quenching Activity of Phenolic Compounds from the Whole Plant of Galium verum var. asiaticum

  • Kim, Dae-Keun
    • Natural Product Sciences
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    • v.17 no.4
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    • pp.261-266
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    • 2011
  • During the process of screening for antioxidative effects of natural plants in Korea, by measuring the superoxide quenching activity, methanol extract of the whole plant, Galium verum var. asiaticum (Rubiaceae), was found to show potent antioxidant activity. Subsequent activity-guided fractionation of methanol extract of Galium verum var. asiaticum led to the isolation of five phenolic compounds. Using spectroscopic techniques, the chemical structures were elucidated as: caffeic acid (1), narcissin (2), rutin (3), luteolin-7-O-${\alpha}$-L-rhamnopyranosyl (1 ${\rightarrow}$ 2)-${\beta}$-D-glucopyranoside (4), and luteolin-7-O-${\beta}$-D-glucopyranoside (5). These compounds were isolated for the first time from this plant. Among them, compound 1 showed the most significant riboflavin-originated superoxide and xanthine-originated superoxide quenching activities. Compounds 3 and 4 exhibited mild superoxide quenching effects compared with vitamine C.

Concentration/Purification Technologies: Multi-Functionalities of Nanostructures in Biosensing Fields

  • Son, Sang Jun;Min, Junhong
    • Proceedings of the Korean Vacuum Society Conference
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    • 2013.02a
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    • pp.87-87
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    • 2013
  • Sample concentration and purification processes are essential in the bio-analytical and pharmaceutical fields because most bio samples or media are extremely sophisticated. To concentrate and purify specific substances, passive membrane type filters have been utilized, which is driven by size or charge differences between target and others. The traditional and representative method to identify nucleic acid sequences in the complex biosample is gel electrophoresis, which has been worked by size and net charge of molecules. The adsorption phenomena have been also utilized to concentrate and purify biomolecules. This adsorption of biomolecule can be controlled under specific salts and surfaces as well as surface area. To utilize the differences of physical properties of molecules or bio-targets such as virus, bacteria, and cells, the nanotechnologies can be introduced in target concentration, purification, and isolation processes. In here, I'd like to briefly survey typical examples of nanobiotechnologies which are introduced in sample treatment. Also I specifically demonstrate two different simple techniques to concentrate and detect bacteria from the samples using multifunctional silica nanotube (SNT).

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Fault Detection of the Control System Based on Multiprocessors (다중 프로세서를 이용한 제어 시스템에서의 자체고장탐지)

  • ;;;;Zeung Nam Bien
    • Journal of the Korean Institute of Telematics and Electronics
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    • v.25 no.8
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    • pp.906-915
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    • 1988
  • The reliability enhancement is the critical issue in many computer applications, particulary in process control system. In this paper we describe how to achieve the reliability improvement in control system which is based on multiprocessors. The proposed method is accomplished by using the techniques of fault detection which composed by internal and external fault detections, fault isolation for removing the fault propagation, safety action for driving safe input, and fault diagnosis. This approach is experimented and asopted in boiler backup control system constructed by VMEbus system, CPU boards, graphic system, and other interface boards with UNIX operating system.

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Implementation of a Virtual Machine Monitor for ARMv7 Architecture (ARMv7 구조를 위한 가상 머신 모니터 구현)

  • Oh, Seung-Jae;Shin, Dongha
    • IEMEK Journal of Embedded Systems and Applications
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    • v.8 no.3
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    • pp.145-153
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    • 2013
  • Virtualization technology has been applied in IA-32 based server or desktop systems. Recently it has been applied in ARM based mobile systems. Virtualization technology provides many useful features that are not possible in operating system level such as isolation, interposition, encapsulation and portability. In this research, we implement an ARM based VMM(Virtual Machine Monitor) by using the following techniques. First, we use "emulation" to virtualize the processor. Second, we use "shadow page tables" to virtualize the memory. Finally, we use a simple "pass-through I/O" to virtualize the device. Currently the VMM runs ARM Linux kernel 3.4.4 on a BeagleBoard-xM, and we evaluated the performance of the VMM using lmbench and dhrystone. The result of the evaluation shows that our VMM is slower than Xen on ARM that is implemented using paravirtualization but has good performance among the VMMs using full-virtualization.