scholarly journals INFLUENCE OF CONSTRUCTIVE ARRANGEMENT DECISIONS AND MANUFACTURING ERRORS OF ELEMENTS OF THE WIDEBAND HORN ANTENNA ON ITS TECHNICAL CHARACTERISTICS

2019 ◽  
pp. 98-109
Author(s):  
O. A. Nahorniuk ◽  
Y. O. Kolos
Keyword(s):  
Three Dimensional ◽  
Horn Antenna ◽  
Significant Deterioration ◽  
Dielectric Characteristics ◽  
Insulating Material ◽  
Specialized Software ◽  
Computer Aided ◽  
Manufacturing Errors ◽  
Bolt Connection ◽  
Constituent Elements

The results of the research of the main releases of arrangement of horn antenna with two ridges, which differ in the ways of fixing the elements: bolt connection (rivets) and soldering (welding), are presented in the article. The influence of inaccuracies in the manufacture of particular antenna elements (errors in the geometric dimensions of the waveguide and the horn aperture, errors in the location of the feed pin, differences in the relative permittivity of the insulating material from the calculated one and others) and their interconnections (the width of the slots between the horn aperture plates, the distance between the ridges at the feeding point) on the main antenna characteristics (voltage standing-wave ratio, gain, radiation pattern). The researches were carried out using software environments for computer-aided designing, modeling and optimizing three-dimensional electromagnetic systems ANTENNA MAGUS and CST STUDIO SUITE. It has been found that with the same accuracy of manufacturing the constituent elements of a wideband horn antenna, the considered releases of arrangement provide similar technical characteristics. The research of manufacturing errors of the antenna elements and their interconnections showed that the longitudinal waveguide dimensions, the distance between the ridges at the point of excitation, the location and diameter of the feed pin, and also the dielectric characteristics of the insulating material have the greatest influence on the characteristics of the antenna. It has been established that a change in particular antenna sizes by 10% can lead to a significant deterioration in its matching. The system of tolerances for the sizes and connections of antenna elements, the adherence of which will ensure the conformity of the characteristics of the manufactured example to those obtained in the process of modeling and optimization using specialized software, is justified.

INVESTIGATION OF THE INFLUENCE OF THE METAMATERIAL PYRAMIDAL HORN INTEGRATED INTO THE CONSTRUCTION ON THE DIRECTIONAL DIAGRAM

2020 ◽  
pp. 107-113
Author(s):  
Е.А. Ищенко ◽  
Ю.Г. Пастернак ◽  
М.А. Сиваш ◽  
С.М. Фёдоров
Keyword(s):  
Radiation Pattern ◽  
Three Dimensional ◽  
Horn Antenna ◽  
Target Range ◽  
Directional Diagram ◽  
Specialized Software ◽  
Wide Range ◽  
Pyramidal Horn ◽  
Three Dimensional Models ◽  
Electrodynamic Modeling

Рассматривается метаматериал, который интегрирован в конструкцию пирамидальной рупорной антенны. Коммутация узлов метаматериала позволяет осуществлять управление диаграммой направленности рассматриваемой антенны. Для замыкания узлов в решетке метаматериала применяются pin-диоды, которые имеют в открытом состоянии эквивалентную схему, представляющую собой последовательное соединение сопротивления 2,1 Ом и индуктивности 0,6 нГн. Предложенная конструкция позволяет добиться управления характеристиками диаграммы направленности рассматриваемой антенны в широких пределах. Управление характеристиками антенн путем применения метаматериалов различных конструкций является передовым методом управления характеристиками излучателя. Для получения результатов применялось электродинамическое моделирование в специализированном программном обеспечении, на основе полученных результатов были построены диаграммы направленности в диапазоне работы рупорной антенны. Приведены результаты моделирования в виде трехмерных моделей исследуемых конструкций метаматериала, коммутируемых узлов; диаграммы направленности полученных антенн, на которых были определены изменения, вносимые коммутируемыми линиями метаматериала. Наибольшее изменение картин диаграмм направленности наблюдалось на частотах 13 и 14 ГГц, входящих в целевой диапазон работ рупорной антенны, основные исследования производились в H-плоскости рупора, так как коммутации подвергались вертикальные линии метаматериала The article discusses a metamaterial that is integrated into the structure of a pyramidal horn. Switching the nodes of the metamaterial allows you to control the radiation pattern of the antenna in question. To close the nodes in the lattice of the metamaterial, pin diodes are used, which in the open state have an equivalent circuit, which is a series connection of a resistance of 2.1 Ohm and an inductance of 0.6 nH. The proposed design makes it possible to achieve control over the characteristics of the radiation pattern of the antenna in question over a wide range. Antenna control by the use of metamaterials of various designs is an advanced method of a beam control. To obtain the results, electrodynamic modeling was used in specialized software, on the basis of the results obtained, directional patterns were constructed in the operating range of the horn antenna. The article presents the results of modeling in the form of three-dimensional models of the investigated metamaterial structures, switched nodes; directional diagrams of the received antennas, on which the changes introduced by the switched lines of the metamaterial were determined. The greatest change in the patterns of radiation patterns was observed at frequencies of 13 and 14 GHz, included in the target range of the horn antenna, the main studies were carried out in the H-plane of the horn, since the vertical lines of the metamaterial were subjected to commutation

Computer-aided methods for 3-D visualization of serial sections and thick biological specimens

1992 ◽  
Vol 50 (2) ◽  
pp. 1060-1061
Author(s):  
Mark Ellisman ◽  
Maryann Martone ◽  
Gabriel Soto ◽  
Eleizer Masliah ◽  
David Hessler ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Three Dimensional ◽  
Neuritic Plaque ◽  
Dimensional Structure ◽  
Data Sets ◽  
Molecular Physiology ◽  
Research Activities ◽  
Computer Aided ◽  
Dimensional Reconstruction

Structurally-oriented biologists examine cells, tissues, organelles and macromolecules in order to gain insight into cellular and molecular physiology by relating structure to function. The understanding of these structures can be greatly enhanced by the use of techniques for the visualization and quantitative analysis of three-dimensional structure. Three projects from current research activities will be presented in order to illustrate both the present capabilities of computer aided techniques as well as their limitations and future possibilities.The first project concerns the three-dimensional reconstruction of the neuritic plaques found in the brains of patients with Alzheimer's disease. We have developed a software package “Synu” for investigation of 3D data sets which has been used in conjunction with laser confocal light microscopy to study the structure of the neuritic plaque. Tissue sections of autopsy samples from patients with Alzheimer's disease were double-labeled for tau, a cytoskeletal marker for abnormal neurites, and synaptophysin, a marker of presynaptic terminals.

Three-Dimensional Subcellular Organization of Hepatocytes in Intact Liver: Simultaneous Visualization of Cytoskeletal and Membrane Markers by Confocal Microscopy

1996 ◽  
Vol 54 ◽  
pp. 288-289
Author(s):  
Greg V. Martin ◽  
Ann L. Hubbard
Keyword(s):  
Three Dimensional ◽  
Integral Membrane Proteins ◽  
Polarized Secretion ◽  
Microscope Images ◽  
Computer Aided ◽  
Intracellular Organelles ◽  
Cytoskeletal Elements ◽  
Simultaneous Visualization

The microtubule (MT) cytoskeleton is necessary for many of the polarized functions of hepatocytes. Among the functions dependent on the MT-based cytoskeleton are polarized secretion of proteins, delivery of endocytosed material to lysosomes, and transcytosis of integral plasma membrane (PM) proteins. Although microtubules have been shown to be crucial to the establishment and maintenance of functional and structural polarization in the hepatocyte, little is known about the architecture of the hepatocyte MT cytoskeleton in vivo, particularly with regard to its relationship to PM domains and membranous organelles. Using an in situ extraction technique that preserves both microtubules and cellular membranes, we have developed a protocol for immunofluorescent co-localization of cytoskeletal elements and integral membrane proteins within 20 µm cryosections of fixed rat liver. Computer-aided 3D reconstruction of multi-spectral confocal microscope images was used to visualize the spatial relationships among the MT cytoskeleton, PM domains and intracellular organelles.

scholarly journals Automatized Evaluation of Students’ CAD Models

2021 ◽  
Vol 11 (4) ◽  
pp. 145
Author(s):  
Nenad Bojcetic ◽  
Filip Valjak ◽  
Dragan Zezelj ◽  
Tomislav Martinec
Keyword(s):  
Computer Aided Design ◽  
Three Dimensional ◽  
Computer Application ◽  
Test Cases ◽  
Cad Model ◽  
Computer Solution ◽  
3D Cad ◽  
Computer Aided ◽  
Cad Models ◽  
Aided Design

The article describes an attempt to address the automatized evaluation of student three-dimensional (3D) computer-aided design (CAD) models. The driving idea was conceptualized under the restraints of the COVID pandemic, driven by the problem of evaluating a large number of student 3D CAD models. The described computer solution can be implemented using any CAD computer application that supports customization. Test cases showed that the proposed solution was valid and could be used to evaluate many students’ 3D CAD models. The computer solution can also be used to help students to better understand how to create a 3D CAD model, thereby complying with the requirements of particular teachers.

scholarly journals Extrusion Based 3D Printing of Sustainable Biocomposites from Biocarbon and Poly(trimethylene terephthalate)

Molecules ◽  
2021 ◽  
Vol 26 (14) ◽  
pp. 4164
Author(s):  
Elizabeth Diederichs ◽  
Maisyn Picard ◽  
Boon Peng Chang ◽  
Manjusri Misra ◽  
Amar Mohanty
Keyword(s):  
Mechanical Properties ◽  
3D Printing ◽  
Surface Finish ◽  
Three Dimensional ◽  
Morphological Properties ◽  
Great Promise ◽  
Structural Components ◽  
Computer Aided ◽  
Trimethylene Terephthalate ◽  
Optimal Quantity

Three-dimensional (3D) printing manufactures intricate computer aided designs without time and resource spent for mold creation. The rapid growth of this industry has led to its extensive use in the automotive, biomedical, and electrical industries. In this work, biobased poly(trimethylene terephthalate) (PTT) blends were combined with pyrolyzed biomass to create sustainable and novel printing materials. The Miscanthus biocarbon (BC), generated from pyrolysis at 650 °C, was combined with an optimized PTT blend at 5 and 10 wt % to generate filaments for extrusion 3D printing. Samples were printed and analyzed according to their thermal, mechanical, and morphological properties. Although there were no significant differences seen in the mechanical properties between the two BC composites, the optimal quantity of BC was 5 wt % based upon dimensional stability, ease of printing, and surface finish. These printable materials show great promise for implementation into customizable, non-structural components in the electrical and automotive industries.

scholarly journals H-plane horn antenna with enhanced directivity using conformal transformation optics

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Hossein Eskandari ◽  
Juan Luis Albadalejo-Lijarcio ◽  
Oskar Zetterstrom ◽  
Tomáš Tyc ◽  
Oscar Quevedo-Teruel
Keyword(s):  
Conformal Transformation ◽  
Phase Error ◽  
Three Dimensional ◽  
Physical Space ◽  
Horn Antenna ◽  
High Gain ◽  
Transformation Optics ◽  
Graded Index ◽  
Low Profile ◽  
Dielectric Lens

AbstractConformal transformation optics is employed to enhance an H-plane horn’s directivity by designing a graded-index all-dielectric lens. The transformation is applied so that the phase error at the aperture is gradually eliminated inside the lens, leading to a low-profile high-gain lens antenna. The physical space shape is modified such that singular index values are avoided, and the optical path inside the lens is rescaled to eliminate superluminal regions. A prototype of the lens is fabricated using three-dimensional printing. The measurement results show that the realized gain of an H-plane horn antenna can be improved by 1.5–2.4 dB compared to a reference H-plane horn.

scholarly journals Experimental & FEM Analysis of Orthodontic Mini-Implant Design on Primary Stability

2021 ◽  
Vol 11 (12) ◽  
pp. 5461
Author(s):  
Elmedin Mešić ◽  
Enis Muratović ◽  
Lejla Redžepagić-Vražalica ◽  
Nedim Pervan ◽  
Adis J. Muminović ◽  
...  
Keyword(s):  
Finite Element ◽  
Three Dimensional ◽  
Primary Stability ◽  
Fem Analysis ◽  
Implant Design ◽  
Special Focus ◽  
Engineering System ◽  
Mini Implants ◽  
Pull Out ◽  
Computer Aided

The main objective of this research is to establish a connection between orthodontic mini-implant design, pull-out force and primary stability by comparing two commercial mini-implants or temporary anchorage devices, Tomas®-pin and Perfect Anchor. Mini-implant geometric analysis and quantification of bone characteristics are performed, whereupon experimental in vitro pull-out test is conducted. With the use of the CATIA (Computer Aided Three-dimensional Interactive Application) CAD (Computer Aided Design)/CAM (Computer Aided Manufacturing)/CAE (Computer Aided Engineering) system, 3D (Three-dimensional) geometric models of mini-implants and bone segments are created. Afterwards, those same models are imported into Abaqus software, where finite element models are generated with a special focus on material properties, boundary conditions and interactions. FEM (Finite Element Method) analysis is used to simulate the pull-out test. Then, the results of the structural analysis are compared with the experimental results. The FEM analysis results contain information about maximum stresses on implant–bone system caused due to the pull-out force. It is determined that the core diameter of a screw thread and conicity are the main factors of the mini-implant design that have a direct impact on primary stability. Additionally, stresses generated on the Tomas®-pin model are lower than stresses on Perfect Anchor, even though Tomas®-pin endures greater pull-out forces, the implant system with implemented Tomas®-pin still represents a more stressed system due to the uniform distribution of stresses with bigger values.

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