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Journal articles on the topic 'Conical monopole'

Author: Grafiati

Published: 28 June 2021

Last updated: 5 February 2022

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1

Jeong, Hye-Mi, Seong-Bae Park, Choon-Won Kim, Ononchimeg Sodnomtseren, Jai-Hoon Bang, and Biemg-Chearl Ahn. "A Conical-Cylindrical Monopole Antenna." Journal of electromagnetic engineering and science 7, no. 3 (September 30, 2007): 138–46. http://dx.doi.org/10.5515/jkiees.2007.7.3.138.

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2

Hu, Z. H., P. S. Hall, J. R. Kelly, and P. Gardner. "Improved band-notched wideband conical monopole antenna." Microwave and Optical Technology Letters 53, no. 8 (May 17, 2011): 1825–29. http://dx.doi.org/10.1002/mop.26132.

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3

BANERJEE, A., and T. GHOSH. "MOTION AROUND A GLOBAL MONOPOLE." International Journal of Modern Physics A 15, no. 06 (March 10, 2000): 869–73. http://dx.doi.org/10.1142/s0217751x00000410.

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The motion of test particles and light rays in the perturbed gravitational field around a global monopole is studied. The metric of the monopole was previously obtained by solving the linearized semiclassical Einstein equations (Hiscock). The bending of light ray passing by such a monopole has contributions from the conical object as well as from the perturbed terms. The possibility of trapping particles in the perturbed gravitational field is also discussed.

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4

Jang, Eun-Seok, Che-Young Kim, Dae-Geun Yang, and Sung-Su Hong. "Suppressed Band Characteristics of an UWB Conical Monopole Antenna with Split Loops Based on the Equivalent Circuit." International Journal of Antennas and Propagation 2017 (2017): 1–8. http://dx.doi.org/10.1155/2017/5375036.

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In this study, the principle of band suppressing an UWB antenna by attaching a small resonator is explained by developing its equivalent circuit. The realized UWB antenna is a conical monopole antenna that contains a split loop for band suppression. The conical monopole antenna corresponds to a transmission line terminated with load impedance, and the split loop is an LC resonator. The coupling between the conical monopole antenna and the split loop is represented as mutual inductance. Equivalent circuits for the UWB antenna suppressing single band [WLAN] and dual band [WLAN, WiMAX] have been suggested, and these equivalent circuits provide insight into the performance characteristics of the developed band suppressed UWB antenna to which a small sized resonator is installed. Simulation and measurement results on the input impedance and VSWR of the proposed equivalent circuit are closely matched. Thus, the validity of the equivalent circuit is confirmed. The measurement results demonstrate that the proposed antenna exhibits a gain of over 3 dBi in the working band and has an omnidirectional radiation pattern. Band rejection has been also implemented by split loops.

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5

Hynes, Christopher G., and Rodney G. Vaughan. "Conical Monopole Antenna With Integrated Tunable Notch Filters." IEEE Antennas and Wireless Propagation Letters 19, no. 12 (December 2020): 2398–402. http://dx.doi.org/10.1109/lawp.2020.3034079.

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6

Hu, Zhen Hua Sampson, James Robert Kelly, Peter S. Hall, and Peter Gardner. "WIDEBAND CONICAL MONOPOLE ANTENNA WITH INTEGRATED STOPBAND FILTER." Progress In Electromagnetics Research C 27 (2012): 223–38. http://dx.doi.org/10.2528/pierc11111305.

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7

Zhongxiang Shen and Jianpeng Wang. "Top-Hat Monopole Antenna for Conical-Beam Radiation." IEEE Antennas and Wireless Propagation Letters 10 (2011): 396–98. http://dx.doi.org/10.1109/lawp.2011.2152359.

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8

Harish, Konam, and N. V. S. N. Sarma. "Ultra Wide Band conical monopole antenna for Wireless Applications." International Journal of Engineering Trends and Technology 35, no. 12 (May 25, 2016): 590–92. http://dx.doi.org/10.14445/22315381/ijett-v35p319.

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9

Yeoh, W. S., and Wayne S. T. Rowe. "An UWB Conical Monopole Antenna for Multiservice Wireless Applications." IEEE Antennas and Wireless Propagation Letters 14 (2015): 1085–88. http://dx.doi.org/10.1109/lawp.2015.2394295.

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10

Hu, Z. H., P. S. Hall, J. R. Kelly, and P. Gardner. "Wideband conical monopole antenna with frequency band-notched behaviour." Electronics Letters 46, no. 23 (2010): 1542. http://dx.doi.org/10.1049/el.2010.2441.

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11

Karki, Sumit, Marco Sabbadini, Khaldoun Alkhalifeh, and Christophe Craeye. "Metallic Monopole Parasitic Antenna With Circularly Polarized Conical Patterns." IEEE Transactions on Antennas and Propagation 67, no. 8 (August 2019): 5243–52. http://dx.doi.org/10.1109/tap.2019.2916737.

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12

Tak, Jinpil, Do-Gu Kang, and Jaehoon Choi. "Stepped Cylindrical Antenna with a Higher-Order Mode Ring Patch for Wideband Conical Radiation Pattern." International Journal of Antennas and Propagation 2015 (2015): 1–7. http://dx.doi.org/10.1155/2015/394621.

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A stepped cylindrical antenna with a higher-order mode ring patch for wideband conical radiation pattern is proposed. To accomplish a low profile with wideband conical radiation characteristics, a stepped cylindrical monopole and a TM41higher-order mode ring patch with four shorting pins are utilized. The proposed antenna has a monopole-like radiation pattern with a wide 10-dB return loss bandwidth of 11 GHz (2 GHz–13 GHz). It can cover various wireless services, such as wireless broadband (WiBro; 2.3 GHz–2.39 GHz), wireless local area networks (WLAN; 2.4 GHz–2.484 GHz, 5.15 GHz–5.35 GHz, and 5.725 GHz–5.875 GHz), digital multimedia broadcasting (DMB; 2.63 GHz–2.655 GHz), and ultra wideband (UWB; 3.1 GHz–10.6 GHz). The antenna has a height of only 0.12λ0at 2 GHz.

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13

Chan, C. T., Zhi Hong Hang, and Xueqin Huang. "Dirac Dispersion in Two-Dimensional Photonic Crystals." Advances in OptoElectronics 2012 (October 22, 2012): 1–11. http://dx.doi.org/10.1155/2012/313984.

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We show how one may obtain conical (Dirac) dispersions in photonic crystals, and in some cases, such conical dispersions can be used to create a metamaterial with an effective zero refractive index. We show specifically that in two-dimensional photonic crystals with C4v symmetry, we can adjust the system parameters to obtain accidental triple degeneracy at Γ point, whose band dispersion comprises two linear bands that generate conical dispersion surfaces and an additional flat band crossing the Dirac-like point. If this triply degenerate state is formed by monopole and dipole excitations, the system can be mapped to an effective medium with permittivity and permeability equal to zero simultaneously, and this system can transport wave as if the refractive index is effectively zero. However, not all the triply degenerate states can be described by monopole and dipole excitations and in those cases, the conical dispersion may not be related to an effective zero refractive index. Using multiple scattering theory, we calculate the Berry phase of the eigenmodes in the Dirac-like cone to be equal to zero for modes in the Dirac-like cone at the zone center, in contrast with the Berry phase of π for Dirac cones at the zone boundary.

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14

Hu, Zhi Hui, Yong Hua Jiang, and Xiang Ling. "Design and Analysis of a CPW-Fed Broadband Conical Conformal Antenna." Applied Mechanics and Materials 229-231 (November 2012): 1622–25. http://dx.doi.org/10.4028/www.scientific.net/amm.229-231.1622.

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A CPW-fed microstrip monopole antenna which is conformal to a conical surface is presented in this paper. It has a simple structure printed on a substrate with dielectric constant of 2.55 and thickness of 0.2mm. By the aid of electromagnetic simulation software of CST Microwave Studio, the main influencing parameters of the antenna are simulated and analyzed, the difference between planar antenna and conical conformal antenna has been discussed, and the optimized physical model has been achieved. The simulated result shows the proposed CPW-fed conical conformal antenna has a broad bandwidth property that covers from 6.2 to 20GHz(VSWR 2), and it is suitable for wideband radar applications.

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15

Pang, Feng, Guoxiang Ai, Jungang Yin, Yue Ma, Chao Hu, Junxia Cui, Lihua Ma, Chan Hwang See, and Raed A. Abd-Alhameed. "CONICAL BEAM MONOPOLE ANTENNA DESIGN FOR CHINESE AREA POSITIONING SYSTEM." Progress In Electromagnetics Research C 68 (2016): 193–200. http://dx.doi.org/10.2528/pierc16083005.

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16

Všetula, P., and Z. Raida. "Broadband monopole antenna with convex conical reflector for 802.11a standard." Microwave and Optical Technology Letters 55, no. 6 (March 27, 2013): 1243–47. http://dx.doi.org/10.1002/mop.27598.

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17

Zhou, Hang, Shaobo Qu, Baoqin Lin, Jiafu Wang, Hua Ma, Zhuo Xu, Weidong Peng, and Peng Bai. "Filter-Antenna Consisting of Conical FSS Radome and Monopole Antenna." IEEE Transactions on Antennas and Propagation 60, no. 6 (June 2012): 3040–45. http://dx.doi.org/10.1109/tap.2012.2194648.

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18

Plyushchay, Mikhail S. "Free conical dynamics: charge-monopole as a particle with spin, anyon and nonlinear fermion-monopole supersymmetry." Nuclear Physics B - Proceedings Supplements 102-103 (September 2001): 248–55. http://dx.doi.org/10.1016/s0920-5632(01)01563-8.

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19

Best, S. R. "A multiband conical monopole antenna derived from a modified Sierpinski gasket." IEEE Antennas and Wireless Propagation Letters 2 (2003): 205–7. http://dx.doi.org/10.1109/lawp.2003.819665.

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20

Yadam, Yugandhara Rao, Sarathi Ramanujam, and Kavitha Arunachalam. "An Ultrawideband Conical Monopole With Radome for Detection of Partial Discharges." IEEE Sensors Journal 21, no. 17 (September 1, 2021): 18764–72. http://dx.doi.org/10.1109/jsen.2021.3090099.

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21

Krail, Paul M., and Y. Shin. "Deconvolution of a directional marine source." GEOPHYSICS 55, no. 12 (December 1990): 1542–48. http://dx.doi.org/10.1190/1.1442805.

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A single source firing below the surface of the ocean, because of the surface reflection, has directionality. Directionality is defined as variation of amplitude with angle. Conceptually the radiation field of such a source may be treated as due to a vertical dipole of finite length. A formulation for transforming data recorded with a dipole wavelet to that of a monopole or plane‐wave wavelet is derived in this study. We have found that the cylindrical τ-p transform allows the removal of the source waveform and amplitude variation in the data due to the dipole and observed on the offset‐time record. The spherical wave field of a vertical dipole can be expanded in a conical bundle of plane waves. Accordingly, the recorded seismic data are transformed into a conical bundle of plane waves by the cylindrical τ-p transform. In this form the directionality effects of the vertical dipole are removed from the data. The formulation derived here was implemented in discrete form. A model study was conducted using synthetic dipole data and the results show the transformation to a monopole.

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22

Pereira, Francisco Estêvão Simão, and Maurício Henrique Costa Dias. "On the Design of Conical Antennas for Broadband Impedance Matching Performance." International Journal of Antennas and Propagation 2017 (2017): 1–13. http://dx.doi.org/10.1155/2017/1691580.

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In the scope of broadband radiators, the biconical antenna, or its monopole conical counterpart, is long known to be a proper choice. One common form of such radiator, the spherically capped conical antenna (SCCA), has closed-form solution to its input impedance, from which the broadband performance potential is easily verified. Nonetheless, from the design perspective, apart from a few clues inferred from existing solutions, little is found to accurately guide the choice of the main geometrical parameters of the antenna that will enable it to comply with a set of imposed bandwidth requirements. This paper proposes a simple 10-step sequence to derive conical or biconical antenna design charts. These charts provide straightforward information on the geometrical limits within which the required antenna impedance matching broadband performance is achieved. The method is assessed for the SCCA and the open conical antenna (OCA) using theoretical and simulated estimates of the input impedance. A discussion on the impact of the cap and the feed gap is included.

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23

Kaushik, V. R., and R. K. Gangwar. "A Novel Four Element Low Profile and Compact Conical Dielectric Resonator Antenna for Wideband Applications." Advanced Electromagnetics 7, no. 2 (February 28, 2018): 1–4. http://dx.doi.org/10.7716/aem.v7i2.650.

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In this paper, a four element Conical Dielectric Resonator Antenna fed through coaxial probe is presented. This Low Profile and compact novel Antenna is designed for Wideband application and its input and radiation characteristics determined through the Ansoft High Frequency Structure Simulator (HFSS) Software. The proposed antenna provides wide Bandwidth (45%) and high average gain (5.15 dBi) with Monopole type Radiation Pattern.

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24

Jang, Eun Seok, Kyungsoo Kim, Jeung Keun Park, and Che-Young Kim. "A selective robust SRR providing notched band in conical monopole UWB antenna." Microwave and Optical Technology Letters 58, no. 2 (December 24, 2015): 332–37. http://dx.doi.org/10.1002/mop.29553.

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25

Grats, Yuri V., and Pavel Spirin. "Vacuum polarization in the background of conical singularity." International Journal of Modern Physics A 35, no. 02n03 (January 30, 2020): 2040030. http://dx.doi.org/10.1142/s0217751x20400308.

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We consider the gravity-induced effects associated with a massless scalar field living in a higher-dimensional spacetime being the tensor product of Minkowski space and spherically-symmetric space with angle deficit. These spacetimes are considered as simple models for a multidimensional global monopole or cosmic string with flat extra dimensions, where the deficit of solid angle is proportional to Newton constant and tension. Thus, we refer to them as conical backgrounds. In terms of the angular deficit value, we derive the perturbative expression for the scalar Green’s function and compute it to the leading order. With the use of this Green’s function we compute the renormalized vacuum expectation value of the scalar-field’s energy-momentum tensor. We make some general note on the linear-on-curvature part of the trace of even coefficients of Schwinger-deWitt expansion.

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26

Artner, Gerald, Philipp K. Gentner, Johann Nicolics, and Christoph F. Mecklenbräuker. "Carbon Fiber Reinforced Polymer with Shredded Fibers: Quasi-Isotropic Material Properties and Antenna Performance." International Journal of Antennas and Propagation 2017 (2017): 1–11. http://dx.doi.org/10.1155/2017/6152651.

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A carbon fiber reinforced polymer (CFRP) laminate, with the top layer consisting of shredded fibers, is proposed and manufactured. The shredded fibers are aligned randomly on the surface to achieve a more isotropic conductivity, as is desired in antenna applications. Moreover, fiber shreds can be recycled from carbon fiber composites. Conductivity, permittivity, and permeability are obtained with the Nicolson-Ross-Weir method from material samples measured inside rectangular waveguides in the frequency range of 4 to 6 GHz. The decrease in material anisotropy results in negligible influence on antennas. This is shown by measuring the proposed CFRP as ground plane material for both a narrowband wire monopole antenna for 5.9 GHz and an ultrawideband conical monopole antenna for 1–10 GHz. For comparison, all measurements are repeated with a twill-weave CFRP.

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27

Furuya, Kiyoshi, Ken Kawamata, and Shigeki Minegishi. "Experimental Study on Return Loss of Exponential Tapered Line Type Conical Monopole Antenna." IEEJ Transactions on Fundamentals and Materials 135, no. 5 (2015): 271–75. http://dx.doi.org/10.1541/ieejfms.135.271.

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28

Dzagbletey, Philip Ayiku, Jin-Young Jeong, and Jae-Young Chung. "Ultra-Wideband Trident Inset-Fed Monopole Antenna With a 3-D Conical Ground." IEEE Access 9 (2021): 2592–601. http://dx.doi.org/10.1109/access.2020.3047424.

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29

Saunders Filho, Claudio A. B., M. H. C. Dias, and J. C. A. Santos. "A Novel Broadband Modified Monopole by the Use of a Parasitic Conical Skirt." IEEE Antennas and Wireless Propagation Letters 11 (2012): 1249–52. http://dx.doi.org/10.1109/lawp.2012.2225592.

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30

Guha, Debatosh, Bidisha Gupta, and Yahia M. M. Antar. "Hybrid Monopole-DRAs Using Hemispherical/ Conical-Shaped Dielectric Ring Resonators: Improved Ultrawideband Designs." IEEE Transactions on Antennas and Propagation 60, no. 1 (January 2012): 393–98. http://dx.doi.org/10.1109/tap.2011.2167948.

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31

Wang, Jian, Yin-Shui Xia, and Lun-Yao Wang. "Electromagnetic responses of a metallic conical frustum cabin with one coaxial feeding monopole antenna." International Journal of Applied Electromagnetics and Mechanics 47, no. 3 (March 1, 2015): 765–76. http://dx.doi.org/10.3233/jae-140112.

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32

Naser-Moghadasi, M., M. Alamolhoda, B. Rahmati, and Bal S. Virdee. "Ultra-Wideband Omnidirectional Top-Loaded Rolled Planar Monopole Antenna with Truncated Conical Ground-Plane." Electromagnetics 32, no. 4 (April 27, 2012): 233–43. http://dx.doi.org/10.1080/02726343.2012.672043.

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33

Ozzaim, Cengiz, Fatih Ustuner, and Nevzat Tarim. "Stacked Conical Ring Dielectric Resonator Antenna Excited by a Monopole for Improved Ultrawide Bandwidth." IEEE Transactions on Antennas and Propagation 61, no. 3 (March 2013): 1435–38. http://dx.doi.org/10.1109/tap.2012.2227442.

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34

Liu, Yung-Tao, Che-Wei Su, Kin-Lu Wong, and Chia-Lun Tang. "Experimental study of a top-loaded cylindrical monopole antenna with a truncated-conical ground plane." Microwave and Optical Technology Letters 43, no. 3 (2004): 245–47. http://dx.doi.org/10.1002/mop.20432.

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35

Choi, Dong-Su, Yoon-Seon Choi, Jae-Yeop Jeong, Tae-Hwan Jung, and Jong-Myung Woo. "Four-Array Printed Monopole Yagi-Uda Antenna Mounted on a Small Missile Warhead." Journal of Electromagnetic Engineering and Science 21, no. 2 (April 30, 2021): 143–47. http://dx.doi.org/10.26866/jees.2021.21.2.143.

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In this study, the structure of a circular four-array antenna was designed for a monopulse radar attached to a conical small missile warhead with a diameter of 29 mm and a lateral length of 63 mm. A printed monopole Yagi-Uda antenna was adopted as the basic model for the antenna to decrease production cost and reduce weight. The director structure of the printed monopole Yagi-Uda antenna that we proposed was modified to λ/2 to improve the beam direction. Unlike the existing structure, the proposed director was made to be separated from the ground, so that it could act as a director. The antenna was expanded to a four-array structure for the detection of vertical and horizontal planes. As a result of the design, the S<sub>11</sub> had excellent matching characteristics at the center frequency of 9.375 GHz, and the beam pattern also had directivity in the same direction as the missile travel direction. In the case of gain, it showed more than 6 dBi performance. Finally, the proposed four-array structure antenna was fabricated to verify that the S<sub>11</sub> and radiation patterns were maintained.

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36

Kumar, Pramod, Santanu Dwari, Jitendra Kumar, Amitesh Kumar, and Shailendra Singh. "Investigation of Compact Dielectric Monopole Antenna Integrated with 3D Printed Horn for UWB Applications." Frequenz 72, no. 11-12 (November 27, 2018): 489–501. http://dx.doi.org/10.1515/freq-2017-0273.

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Abstract A novel broadband portable Dielectric Resonator Antenna (DRA) with integrated unshorted horn and broadside radiation pattern is implemented for ultra-wideband (UWB) and Electromagnetic sensor applications. A rectangular DRA composed of TMM 10i (Dielectric constant 9.8 and loss tangent 0.002) material is mounted over four supporting pillars to separate the DRA from the ground plane. A conical shaped horn with the copper foil conductor is used as a reflector to increase the gain and realize stable radiation pattern over the wide frequency range. The horn and supporting pillars are fabricated by a 3-D printer using light weight thermoplastic composite polymer Poly-Lactic Acid (PLA). The proposed antenna contributes measured VSWR (2:1) impedance bandwidth of 106 % ranging from 6.8 GHz to 22.2 GHz for a Quasi-TM111 mode with a low cross-pol level which ensures its linear polarization. The measured peak gain of the DRA is 7.8 dBi at 14 GHz, while estimated average efficiency is more than 88 %. The measured average group delay of the proposed antenna is ~ 1.5 ns within operation band. The proposed antenna is suitable for UWB operation and other broadband applications having omnidirectional coverage and stable radiation pattern ranging from C-band to K-band.

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37

Kurkjian, A. L., R. T. Coates, J. E. White, and H. Schmidt. "Finite‐difference and frequency‐wavenumber modeling of seismic monopole sources and receivers in fluid‐filled boreholes." GEOPHYSICS 59, no. 7 (July 1994): 1053–64. http://dx.doi.org/10.1190/1.1443661.

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In borehole seismic experiments the presence of the borehole has a significant effect on observations. Unfortunately, including boreholes explicitly in modeling schemes excludes the use of some methods (e.g., frequency‐wavenumber) and adds prohibitively to the cost of others (e.g., finite difference). To overcome this problem, we use the concept of an effective source/receiver array to replace the explicit representation of the borehole by a distributed seismic source/receiver. This method mimics the presence of the borehole at seismic frequencies under a wide variety of conditions without adding a significant computational cost. It includes the effects of dispersive and attenuative tube wave propagation, the generation of secondary sources at interfaces and caliper changes, and the generation of conical waves in low‐velocity layers. Comparison with a finite‐difference scheme with an explicit borehole representation validates the approach. The modeling method applied to a continuity logging geometry demonstrates that the presence of guided waves does not uniquely imply bed connectivity. Results for a single‐well imaging geometry emphasize the dominance of the tube wave in the hydrophone synthetics and demonstrates the necessity of using clamped geophones for single‐well experiments. The concept of an effective source/receiver array is an efficient way of including borehole phenomena in seismic modeling methods at minimal extra computational cost.

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38

Biswas, Diptiman, and Asif Rizwan. "Frustum Shaped Conformal Antenna for Spinning Aerial Platform." Defence Science Journal 68, no. 4 (June 26, 2018): 388. http://dx.doi.org/10.14429/dsj.68.12217.

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<p>A novel approach to design and develop frustum shaped conformal antenna for transmission of telemetry data from a missile like spinning aerial platform is described. The requirement necessitates for an omni directional radiation pattern in the roll plane. However, the criteria is not feasible to achieve by using a monopole or a dipole as the omni coverage due to these antennas are restricted only in yaw or azimuth plane of the aerial platform. A conformal antenna appropriately wrapped on to the surface provides potential solution and accordingly has been configured for meeting the requirements of a practical application. The antenna artwork has been designed to conform to the exterior geometry of the intended portion of conical surface and printed on a microwave substrate which is essentially thin and flexible. A corporate feed distribution scheme has been designed and tailored to match with the impedance of the microstrip radiator at multiple locations and also printed along with it making the frustum antenna very compact and of aerodynamic supportive form. The antenna produces required omni coverage in the plane normal to the roll axis. A step-wise method for the design and development of the frustum conformal antenna through simulation and experiment approach has been discussed.</p>

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39

Vieira, Mário, Miguel Viana, Elsa Henriques, and Luís Reis. "Soil Interaction and Grout Behavior for the NREL Reference Monopile Offshore Wind Turbine." Journal of Marine Science and Engineering 8, no. 4 (April 24, 2020): 298. http://dx.doi.org/10.3390/jmse8040298.

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Monopiles for offshore wind are the most used foundations by farm operators due to their low production costs, when compared to other bottom-fixed or floating foundations. In this research, a monopile foundation for offshore wind power was evaluated for its soil interaction and grout behavior, and an appropriate numerical model for the structural analysis of the foundation and tower was developed. FAST 8, an aero-hydro-servo-elastic numerical code developed by NREL, was used to obtain the loads applied on the supporting structures. These loads were pre-processed before they were inputted on the finite element model, developed using the finite element software ANSYS. The considered conical grout connection, which connects the monopile to the transition piece through friction, was modeled under a changing-status nonlinearity condition. To model the soil–pile interaction, a p-y model was applied using the ANSYS APDL commands. Static, modal, and transient structural analyses were produced to study the structure suitability for its use on offshore environments. Different soil interactions were modeled, and their results were then compared within the transient and modal analysis, indicating that the angle of the grout connection strongly affects the loading conditions on the grout. Moreover, scouring affects the dynamic behavior of the overall supporting structures, thus protection against this phenomenon is suggested.

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40

He, Wei, Yejun He, Long Zhang, Sai-Wai Wong, Wenting Li, and Amir Boag. "A Low-Profile Circularly Polarized Conical-Beam Antenna with Wide Overlap Bandwidth." Wireless Communications and Mobile Computing 2021 (February 27, 2021): 1–11. http://dx.doi.org/10.1155/2021/6648887.

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In this paper, a low-profile circularly polarized (CP) conical-beam antenna with a wide overlap bandwidth is presented. Such an antenna is constructed on the two sides of a square substrate. The antenna consists of a wideband monopolar patch antenna fed by a probe in the center and two sets of arc-hook-shaped branches. The monopolar patch antenna is loaded by a set of conductive shorting vias to achieve a wideband vertically polarized electric field. Two sets of arc-hook-shaped parasitic branches connected to the patch and ground plane can generate a horizontally polarized electric field. To further increase the bandwidth of the horizontally polarized electric field, two types of arc-hook-shaped branches with different sizes are used, which can generate another resonant frequency. When the parameters of the arc-hook-shaped branches are reasonably adjusted, a 90° phase difference can be generated between the vertically polarized electric field and the horizontally polarized electric field, so that the antenna can produce a wideband CP radiation pattern with a conical beam. The proposed antenna has a wide impedance bandwidth ( ∣ S 11 ∣ < − 10 dB ) of 35.6% (4.97-7.14 GHz) and a 3 dB axial ratio (AR) bandwidth at phi = 0 ° and theta = 35 ° of about 30.1% (4.97-6.73 GHz). Compared with the earlier reported conical-beam CP antennas, an important feature of the proposed antenna is that the AR bandwidth is completely included in the impedance bandwidth, that is, the overlap bandwidth of ∣ S 11 ∣ < − 10 dB and AR < 3 dB is 30.1%. Moreover, the stable omnidirectional conical-beam radiation patterns can be maintained within the whole operational bandwidth.

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41

Castrejón-Antonio, Jesús E., Patricia Tamez-Guerra, Roberto Montesinos-Matías, Maria J. Ek-Ramos, Paul M. Garza-López, and Hugo C. Arredondo-Bernal. "Selection of Beauveria bassiana (Hypocreales: Cordycipitaceae) strains to control Xyleborus affinis (Curculionidae: Scolytinae) females." PeerJ 8 (July 3, 2020): e9472. http://dx.doi.org/10.7717/peerj.9472.

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Background Xyleborus affinis Eichhoff (Coleoptera: Curculionidae) is an ambrosia beetle reported to affect avocado trees (Persea americana Mill.). The use of the entomopathogenic fungus (EPF) Beauveria bassiana (Bals.-Criv.) Vuill. for ambrosia beetle control represents an alternative to insecticides. Methods This study was designed in two stages to select B. bassiana strains with potential to control X. affinis females. In the first stage, 19 B. bassiana Mexican strains from EPF collection, isolated from Coleoptera (CHE-CNRCB, http://www.gob.mx/senasica/documentos/coleccion-de-hongos-entomopatogenos), were tested. Analyses included radial growth rate, conidial yield, spore germination, and germ tube length. Results were analysed by Principal Component Analysis (PCA) to identify clusters within favourable growth phenotypes. For the second stage, 10 selected strains were re-analysed for virulence-related metabolic characteristic, including cell wall-bound cuticle-degrading enzymes–Pr1-like proteases and β-N-acetyl glucosaminidases (NAGase) chitinases, conidial hydrophobicity and monopolar germination parameters. A second PCA analysis was run for those virulence parameters analysed, and upon results strains CHE-CNRCB 44, 171, 431 and 485 were selected and tested against X. affinis females. Females were treated with a 1 × 108 conidia mL−1 suspension (recommended rate), using a Potter Tower. Results All strains showed insecticidal activity, inducing up to 58% mortality; about 30% dead beetles developed aerial mycelia (CHE-CNRCB 485) and the fastest mortality rate was t0 = 1.95 (CHE-CNRCB 44). Conclusion Since all selected strains showed virulence against X. affinis females, results indicated the possibility of selecting B. bassiana strains based on multiple metabolic attributes, as a preliminary test to perform bioassays against order-related target insects.

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Niklas, Karol. "Strength Analysis of a Large-Size Supporting Structure for an Offshore Wind Turbine." Polish Maritime Research 24, s1 (April 25, 2017): 156–65. http://dx.doi.org/10.1515/pomr-2017-0034.

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Abstract The offshore wind power industry is the branch of electric energy production from renewable sources which is most intensively developed in EU countries. At present, there is a tendency to install larger-power wind turbines at larger distances from the seashore, on relatively deep waters. Consequently, technological solutions for new supporting structures intended for deeper water regions are undergoing rapid development now. Various design types are proposed and analysed, starting from gravitational supports (GBS), through monopiles and 3D frame structures (jackets, tripods), and ending with floating and submerged supports anchored to the seabed by flexible connectors, including TLP type solutions. The article presents the results of examination of an untypical large-size gravitational support intended for waters with the depth of up to 40 m. Firstly, a general concept of the new design is presented, while the next basic part of the article describes the support design in detail and provides its strength analysis. The examined support has the form of a large steel container consisting of conical segments. The strength analysis was conducted using the finite element method (FEM), in accordance with the standard DNVGL-ST-0126. Modifications introduced to the most heavily loaded structural node of the support, which was the set of base bottom trusses, is also included. The results of the performed analysis prove that the presented concept of supporting structure for a 7MW turbine meets fundamental strength criteria. The nonlinear buckling analysis was performed to evaluate the critical force acting on the support, which turned out to be 1.44 times as large as the maximum load of the wind turbine. Potentially important issues for further analyses have been identified as those resulting from the asymmetry of basic loads acting on the support.

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ALTUNA, AVARO. "Literature analysis and present state of knowledge of benthic Medusozoa (Cnidaria) from the Bay of Biscay and nearby areas (northeastern Atlantic), with emphasis on biodiversity." Zootaxa 1682, no. 1 (January 16, 2008): 1. http://dx.doi.org/10.11646/zootaxa.1682.1.1.

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The literature on benthic Medusozoa (Cnidaria) from the Bay of Biscay and nearby areas (roughly between 42º–48º30’ N and 2°–10º W) is reviewed. Some 213 papers have been inventoried and classified in 17 groups based on their main contents. The present state of knowledge is analyzed, and papers covering each administrative territory of both adjacent countries, Spain and France, are listed. Around 2000, the accumulative curve of new papers and new records reached its ceiling. Some 205 species are known, with the suborder Conica (class Hydrozoa, order Leptothecata) accounting for the highest number of species (110), while the Proboscoida (Hydrozoa: Leptothecata), Filifera and Capitata (both Hydrozoa: Anthoathecata) account for much fewer species (21, 32 and 27 respectively). Only a few species are referable to the remaining subtaxa of Medusozoa, i.e. four to class Staurozoa, six to class Scyphozoa, four to subclass Trachylina (Hydrozoa), and one to order Limnomedusae (Hydrozoa). Species of suborders Capitata and Filifera (Hydrozoa, order Anthoathecata) will probably monopolize new discoveries of species. Knowledge of biodiversity is uneven amongst the different administrative provinces, with Guipúzcoa having the highest number of reported species (111 species, 54% of those known from the whole study area). Little information is available for certain areas, especially the French coasts. The fauna of every Spanish province has been the subject of MSc or PhD taxonomy-targeted research, but no such studies have been undertaken along the French coast. In Spain, the littoral fauna of Cantabria merits more intensive study because it represents an interface between the “cold” southwestern (from Asturias to Pontevedra) and “warm” southeastern (from Vizcaya to Gironde) areas of the Bay of Biscay.

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Carlucci, A., F. Lops, and S. Frisullo. "First Report of Wilt Caused by Verticillium dahliae on Cosmos (Cosmos bipinnatus) in Italy." Plant Disease 93, no. 8 (August 2009): 846. http://dx.doi.org/10.1094/pdis-93-8-0846b.

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Cosmos (Cosmos bipinnatus Cav., Asteraceae) is an herbaceous plant that is grown for landscape use. During August and September of 2008 in five public and three private gardens located in Monopoli (Apulia, southern Italy), 3 to 8% of the plants showed severe symptoms of vine decline, stunting, gradual yellowing and wilting of the leaves, and final collapse of the whole plant. External symptoms were associated with brown or black streaking of the vascular tissue of roots, collar, and stem. Dead plants had numerous microsclerotia embedded in the xylem of plant tissues. Stem, collar, and root sections (0.5 cm long) from symptomatic plants collected in five gardens were surface disinfested in 5% NaOCl for 1 min and transferred to petri dishes containing potato dextrose agar (PDA) amended with 100 μg ml–1 of streptomycin sulfate and 10 μg ml–1 of neomycin. After 10 days of incubation, at 25°C in the dark, hyaline hyphae with dark microsclerotia (37 to 112 μm) and verticillate conidiophores were produced. Conidia were single celled and hyaline with dimensions of 3.3 to 7.8 × 1.8 to 3.3 μm (mean dimensions 4.2 × 2.5 μm). According to morphological characteristics, the fungus was identified as Verticillium dahliae Kleb. (1) (isolates no. Vd1818, Vd1819, and Vd1820 stored in a collection at the Department DiSACD, University of Foggia). Molecular analyses were performed on the basis of nucleotide sequences of the internal transcribed spacer region (ITS1-5.8S-ITS2) of ribosomal DNA. ITS sequences of this fungus, compared with sequences found in GenBank and attributed to V. dahliae (no. GQ130129, GQ130130, GQ130131), showed 98 to 99% sequence similarity. Healthy 40-day-old plants of C. bipinnatus (garden cosmos) cv. Sonata Pink Blusk and C. sulphurous (yellow cosmos) cv. Bilbo, obtained from seeds previously disinfested for 1 min in 3% NaOCl and ascertained to be healthy by isolation on PDA medium, were used for pathogenicity tests. Plants were grown in 3-liter pots in a steam-disinfested peat, sand, and soil mixture (2:1:1) in the greenhouse at 23 to 26°C. Ten plants of each cultivar were inoculated by root dipping into a conidial suspension of each fungal isolate (1.5 × 106 CFU ml–1). Six noninoculated cosmos plants of each cultivar served as controls. The experiment was repeated three times. First symptoms of wilting were observed on all inoculated plants of each cultivar 20 days after the inoculation; at 40 days, symptom severity ratings on plants were taken, in which 1 = asymptomatic, 2 = stunted, 3 = wilting, and 4 = dead. All three isolates caused vascular discoloration, stunting, wilting, and plant death. The mean disease rating was 3.2 and did not differ significantly among isolates. The pathogen was consistently reisolated from infected plants, fulfilling Koch's postulates. Noninoculated plants remained healthy. To our knowledge, this is the first report of Verticillium wilt on cosmos in Italy. The finding is important since other ornamental plants that are susceptible to Verticillium wilt are also grown in landscapes in the region. The disease was previously reported in Turkey (2). References: (1) G. F. Pegg and B. L. Brandy. Verticillium Wilts. CABI Publishing, Wallingford, UK, 2002. (2) E. Sezgin et al. Turk. Phytopathol. 14:43, 1985.

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Louvet, F., C. Dougados, S. Cabrit, D. Mardones, F. Ménard, B. Tabone, C. Pinte, and W. R. F. Dent. "The HH30 edge-on T Tauri star." Astronomy & Astrophysics 618 (October 2018): A120. http://dx.doi.org/10.1051/0004-6361/201731733.

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Context. The disk-outflow connection is thought to play a key role in extracting excess angular momentum from a forming protostar. HH30 is a rare and beautiful example of a pre-main sequence star exhibiting a flared edge-on disk, an optical jet, and a CO molecular outflow, making this object a case study for the disk-jet-outflow paradigm. Aims. We aim to clarify the origin of the small-scale molecular outflow of HH30 and its link and impact on the accretion disk. Methods. We present ALMA 0.25″ angular resolution observations of the circumstellar disk and outflow around the T Tauri star HH30 in the dust continuum at 1.33 mm and of the molecular line transitions of 12CO(2–1) and 13CO(2–1). We performed a disk subtraction from the 12CO emission, from which we analysed the outflow properties in detail in the altitudes z ≲ 250 au. We fit the transverse position-velocity diagrams across the 12CO outflow to derive the ring positions and projected velocity components (including rotation). We use the results of these fits to discuss the origin of the CO outflow. Results. The 1.3 mm continuum emission shows a remarkable elongated morphology along PA = 31.2∘ ± 0.1∘ that has a constant brightness out to a radius of r = 75 au. The emission is marginally resolved in the transverse direction, implying an intrinsic vertical width ≤24 au and an inclination to the line-of-sight i ≥ 84.8∘. The 13CO emission is compatible with emission from a disk in Keplerian rotation, in agreement with the previous findings. The monopolar outflow, detected in 12CO, arises from the north-eastern face of the disk from a disk radius r ≤ 22 au and extends up to 5″ (or 700 au) above the disk plane. We derive a lower limit to the total mass of the CO cavity/outflow of 1.7 × 10−5 M⊙. The CO cavity morphology is that of a hollow cone with semi-opening angle ∼35∘. The derived kinematics are consistent with gas flowing along the conical surface with constant velocity of 9.3 ± 0.7 km s−1. We detect small rotation signatures (Vϕ sin i ∈ [0.1; 0.5] km s−1) in the same sense as the underlying circumstellar disk. From these rotation signatures we infer an average specific angular momentum of the outflow of 38 ± 15 au km s−1 at altitudes z ≤ 250 au. We also report the detection of small amplitude wiggling (1.2∘) of the CO axis around an average inclination to the line of sight of i = 91∘. Conclusions. The derived morphology and kinematics of the CO cavity are compatible with expectations from a slow disk wind, originating either through photo-evaporation or magneto-centrifugal processes. Under the steady assumption, we derive launching radii in the range 0.5–7 au. In that scenario, we confirm the large minimum mass flux of 9 × 10−8 M⊙ yr−1 for the CO wind. The wind would therefore extract a significant amount of the accreted mass flux through the disk and would likely play a crucial role in the disk evolution. If the CO flow originates from a steady-state disk wind, our ALMA observations rule out the 18 au binary orbital scenario previously proposed to account for the wiggling of the optical jet and favour instead a precession scenario in which the CO flow originates from a circumbinary disk around a close (separation ≤ 3.5 au) binary. Alternatively, the CO outflow could also trace the walls of a stationary cavity created by the propagation of multiple bow shocks. Detailed numerical simulations are under way to fully test the entrainment hypothesis.

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Vilas, Carlos. "Editorial." Revista Perspectivas de Políticas Públicas 10, no. 20 (May 30, 2021): 230–31. http://dx.doi.org/10.18294/rppp.2021.3637.

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Estructuras, actores y procesos conforman el hilo unificador de la diversidad de temas específicos trabajados por los artículos que integran el presente número de la revista. Varios textos apuntan al federalismo como dimensión estructurante del estado argentino en sus tres niveles jurisdiccionales y a las tensiones que se suscitan entre el nivel jurisdiccional nacional y los niveles subnacionales. Niembro, Aristimuño y Del Bello someten a escrutinio el efectivo alcance del objetivo de federalización en los ingresos a la carrera de investigador científico y tecnológico del CONICET; demuestran el desigual logro del mismo y los riesgos de un retorno al academicismo que signó momentos precedentes del organismo. Fernando Rubino compara dos experiencias de asociativismo intermunicipal en el Área Metropolitana de Buenos Aires y su eficacia como herramienta de gestión. Piana y Patiño Jaramillo enfocan las estructuras organizativas de la Administración Pública de la provincia de Buenos Aires durante la gobernación de María Eugenia Vidal (2015-19), destacan el contraste entre el discurso oficial privatizador, antipolítico, de achicamiento del estado y recorte de gastos, la realidad de crecimiento de los recursos e incumbencias de los organismos tomados en cuenta y el incremento de los cargos políticos sin afectación funcional específica. La efectiva vigencia de la política nacional de protección de glaciares en las provincias de Santa Cruz y Tierra del Fuego permite a Ana Paula Lucero identificar y explicar las tensiones que se suscitan entre una norma política federal de aplicación universal y los intereses provinciales derivados de su dotación específica de recursos y sus propias estrategias de desarrollo. El complejo acople entre instituciones y procesos políticos federales y regímenes provinciales se explicita en el análisis de la estrategia de construcción de coaliciones electorales de la UCR en la provincia de Santa Fe de cara a los comicios de 2019, llevado a cabo por Ariadna Gallo y Carolina Pérez Roux. Desde la década de 1980, las organizaciones de trabajadores desocupados y habitantes de comunidades precarizadas han dado testimonio de un acelerado crecimiento en magnitud organizativa, eficacia reivindicativa y formulación de propuestas de política pública; relativizaron el cuasi monopolio formal de articulación de intereses por los partidos políticos y el movimiento sindical, contribuyeron a reformular la convencional articulación entre estado y sociedad civil. Julia Nesprias explora la evolución del movimiento villero en la Ciudad de Buenos Aires en su articulación con las políticas institucionales predominantes. El artículo de Maneiro y Núñez describe el proceso de lucha de las organizaciones de trabajadores de la economía popular en torno a la ley de Emergencia Social de 2016, sus estrategias de construcción de alianzas con un amplio arco de la sociedad y del sistema político, en un ambiente político institucional de neoliberalismo gobernante. Finalmente Feldman y Girolimo analizan las políticas de promoción de la industria 4.0 en un contexto de cambio tecnológico acelerado, tomando como referencia las experiencias recientes de México, Argentina y Brasil en digitalización y automatización de procesos productivos; llaman la atención sobre la necesidad de las economías periféricas y la necesidad de afrontar estos desafíos para no profundizar las brechas existentes respecto a los países centrales. En la sección Documentos se publica un análisis de las capacidades políticas y administrativas del estado, desde la perspectiva de la Comisión Estado y Administración Pública del Instituto Patria. Se incluye este documento como un aporte al debate político-académico en torno al rol del sector público en la promoción del desarrollo con equidad social. Con este número la RPPP alcanza su primera década de existencia. En estos diez años fueron aceptados y publicados 150 artículos y 42 reseñas, de los más de 600 originales recibidos. 69 artículos publicados son de autoría femenina (46%), 68 de autoría masculina (45%) y 13 de compartición autoral de género; una sexta parte proviene de autoras y autores afiliados a instituciones académicas del exterior. La variedad de su contenido, acorde a la amplitud de su convocatoria y al amplio campo de análisis del Estado y las políticas públicas, conjuga la calidad académica de acuerdo a los estándares convencionales con el compromiso a los valores sustantivos que inspiran y orientan a la Universidad Nacional de Lanús. Carlos Vilas.

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Jusufi, Kimet. "Conical Morris-Thorne wormholes with a global monopole charge." Physical Review D 98, no. 4 (August 8, 2018). http://dx.doi.org/10.1103/physrevd.98.044016.

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Prasetyo, Ilham, and Handhika S. Ramadhan. "Gravity of a noncanonical global monopole: conical topology and compactification." General Relativity and Gravitation 48, no. 1 (December 19, 2015). http://dx.doi.org/10.1007/s10714-015-1998-x.

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Lotsberg, Inge. "Fatigue Design Recommendations for Conical Connections in Tubular Structures." Journal of Offshore Mechanics and Arctic Engineering 141, no. 1 (August 13, 2018). http://dx.doi.org/10.1115/1.4040800.

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Conical connections are important structural members for the integrity of most types of welded tubular structures. They are for example used in traditional jacket structures for oil and gas production and in monopiles for support of wind turbines where an optimal design is aimed for. From contact with the industry, it is noted that there is uncertainty about the basis for the stress concentration factors (SCF) for conical connections in design standards for fatigue assessment. This is related to how fabrication tolerances are accounted for and how a transition in thickness from the cone to the tubular or the cylinder should be made to minimize stresses due to thickness transitions and fabrication tolerances. Analytical expressions for stress concentrations at conical transitions are outlined in this paper to get a better understanding of the effect of thickness of the cone and the cylinder. By a proper basis for fatigue design, it is possible to control additional stresses from thickness transitions and fabrication tolerances at these connections.

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"Two black holes attached to strings." Proceedings of the Royal Society of London. A. Mathematical and Physical Sciences 423, no. 1865 (June 8, 1989): 387–400. http://dx.doi.org/10.1098/rspa.1989.0061.

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An axisymmetric solution of the Einstein-Maxwell equations is found which represents the static placement of two charged black holes of equal mass ( M ) and opposite charge (± Q ) with ∣Q∣ > M . The space-time, external to the event horizons of the two black holes, is asymptotically flat and entirely smooth except for the occurrence, on the axis, of a simple conical singularity with deficit. In other words, a ‘string’ stretches along the axis of symmetry and provides support for the black holes. In the extended space-time, interior to the horizons of the black holes, time-like curvature singularities, with two spatial dimensions, do occur. And, finally, the surface gravity that prevails on the horizons of the two black holes vanishes. This transgression of the two theorems, excluding the existence of multiple black holes except those of the extreme Reissner–Nordström type and requiring |Q| ≼ M for isolated black holes, is made possible by relaxing the strict requirements of smoothness to the extent of allowing conical singularities. The solution obtained in this paper is, at the classical level, analogous to the equilibrium solution one has found, at the quantal level, for Dirac magnetic monopoles connected by strings.

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