Results 271 to 280 of about 33,172 (312)
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Transformation of plasmid DNA into Streptomyces at high frequency
Nature, 1978OVER 60% of known antibiotics1 are produced by Streptomyces species, including many substances with valuable clinical and other applications; they therefore have considerable medical, biological and commercial importance. Although the process of gene exchange mediated by conjugation within these actinomycetes is apparently widespread2, the transfer of ...
M J, Bibb, J M, Ward, D A, Hopwood
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Transformer model for high frequencies
IEEE Transactions on Power Delivery, 1988A method for the development of a high-frequency transformer model for use in an electromagnetic transient program (EMTP) is discussed. A transformer to be modeled is measured, and the results are used to calculate the transfer and admittance functions. Modal analysis is used to determine a no-load network model that can be used in the EMTP.
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High frequency models of PCB-based transformers
Proceedings of the 44th IEEE 2001 Midwest Symposium on Circuits and Systems. MWSCAS 2001 (Cat. No.01CH37257), 2002An equivalent network of PCB-based transformers with two windings is presented for use at high frequency (some MHz). After raising some criticisms to the traditional high frequency transformer model, a systematic procedure is presented to deduce the inductive and the capacitive coupling model of a two windings transformer.
ARTURI, CESARE MARIO +1 more
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Frequency Characteristics Analysis of High Frequency Current Transformers
Advanced Materials Research, 2014In this paper, the equivalent model of high frequency current transformers (HFCT) for partial discharge online monitoring and its major parameters’ influence on amplitude-and phase frequency characteristics are derived. An optimized design for HFCT for partial discharge online monitoring is summarized.
Yue Dong +4 more
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High voltage, high frequency conversion transformer
IECEC-97 Proceedings of the Thirty-Second Intersociety Energy Conversion Engineering Conference (Cat. No.97CH6203), 2002A 25 kW, 15 kV output, 50 kHz transformer with 100 kV primary to secondary isolation is described. The transformer will be the central element of a resonant inverter. Six of these resonant inverter outputs will be connected in series to produce 90 kV for an airborne application.
C.S. Kerfoot, M.J. Greif
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Optimal design of high-power, mid-high frequency transformer
Proceedings of 2011 International Conference on Electronic & Mechanical Engineering and Information Technology, 2011A high-power, mid-high frequency transformer using silicon steel core is designed for a 30kW, 3 kHz switch-mode power supply (SMPS). Based on the area product method (AP method), the material and type of magnetic core are selected. The winding turns and transformer loss are calculated. The wire specifications are decided.
Gang Wang, Huina Yang
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Conjugate Thermal Analysis of a High-Power and High-Frequency Transformer
2010 IEEE Industry Applications Society Annual Meeting, 2010In this paper, a 3D thermal model that couples thermal and flow fields of a high-power, high-frequency oil-immersed transformer was presented. The thermal model including a set of conservation equations was solved using the finite volume method. The temperature and oil flow velocity distribution are of interest.
Ping-Huey Tang +2 more
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High-frequency investigation of planar transformers
2014 International Conference on Electrical Sciences and Technologies in Maghreb (CISTEM), 2014Planar transformers are a novel type of devices used in integrated power systems. Having many advantages compared to classic wire wound technology; it's used to minimize size and weight and to increase their ability to withstand mechanical vibrations.
Aymen Ammouri +3 more
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A new type high frequency transformer
IEEE Transactions on Magnetics, 1991In order to realize small power supplies, the authors propose a type of coreless high-frequency transformer. This transformer is composed of simple twisted coils and its operating principle is based on the skin effect of current carrying conductors. Approximate analysis based on the symmetrical current distributions in each of the coil axes has been ...
S. Hayano +3 more
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High–Frequency Transformation of Penicillium Chrysogenum
Nature Biotechnology, 1987We report high–frequency transformation of penicillin–producing strains of Penicillium chrysogenum using plasmid vectors carrying the pyr4 gene of Neurospora crassa. Transformation to stable uracil independence is associated with acquisition of transforming DNA in high molecular forms that are not simple multimers of the vector.
J. M. Cantoral +4 more
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