Pub Date : 2021-08-09DOI: 10.23919/USNC-URSIRSM52661.2021.9552337
Joseph Kiflom, Shaun McKellar, Tara Spafford, Huanan Zhang, Tasmia Tasneem, Crysta Oswald, Kaitlin L. Hall, C. Furse
The use of 3D printing in the body has a range of biomedical applications, including development of implantable antennas and other electronics. Using a biocompatible thermally crosslinked polymer material and a coaxial heating applicator, wire-like configurations could be “printed” directly into the body. This paper evaluates the heating time required to solidify the biopolymer in two concentrations of phosphate buffer solution.
{"title":"Measurements on a Thermally-Crosslinked Biopolymer for Future Implantable Antennas","authors":"Joseph Kiflom, Shaun McKellar, Tara Spafford, Huanan Zhang, Tasmia Tasneem, Crysta Oswald, Kaitlin L. Hall, C. Furse","doi":"10.23919/USNC-URSIRSM52661.2021.9552337","DOIUrl":"https://doi.org/10.23919/USNC-URSIRSM52661.2021.9552337","url":null,"abstract":"The use of 3D printing in the body has a range of biomedical applications, including development of implantable antennas and other electronics. Using a biocompatible thermally crosslinked polymer material and a coaxial heating applicator, wire-like configurations could be “printed” directly into the body. This paper evaluates the heating time required to solidify the biopolymer in two concentrations of phosphate buffer solution.","PeriodicalId":365284,"journal":{"name":"2021 USNC-URSI Radio Science Meeting (USCN-URSI RSM)","volume":"8 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-08-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121918980","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-08-09DOI: 10.23919/USNC-URSIRSM52661.2021.9552361
L. Blum, Conrad Meyer‐Reed, M. Shumko, A. Crew
The outer radiation belt is a highly dynamic region of the Earth's magnetosphere, with often-unpredictable variations in intensity and spatial extent. Characterization of this variable radiation environment is critical to mitigating spacecraft anomalies often caused by energetic particles. The physical processes controlling the acceleration and loss of trapped relativistic electrons in the radiation belts are complex and there are a number of competing processes that can combine to produce net enhancements or depletions of the belts. Precipitation into the atmosphere has been shown to be an important loss process for energetic particles in Earth's magnetosphere, but when, where, and how much precipitation contributes remain open questions. While radiation belt diffusion models can now reproduce observed acceleration events quite accurately, radiation belt depletion events are often less well-captured. Quantification of precipitation loss, as well as understanding of the physical mechanisms producing it, is thus critical to our understanding of the dynamics of the outer radiation belt.
{"title":"What the detailed properties of MeV electron microbursts reveal about their scattering mechanisms and contribution to radiation belt loss","authors":"L. Blum, Conrad Meyer‐Reed, M. Shumko, A. Crew","doi":"10.23919/USNC-URSIRSM52661.2021.9552361","DOIUrl":"https://doi.org/10.23919/USNC-URSIRSM52661.2021.9552361","url":null,"abstract":"The outer radiation belt is a highly dynamic region of the Earth's magnetosphere, with often-unpredictable variations in intensity and spatial extent. Characterization of this variable radiation environment is critical to mitigating spacecraft anomalies often caused by energetic particles. The physical processes controlling the acceleration and loss of trapped relativistic electrons in the radiation belts are complex and there are a number of competing processes that can combine to produce net enhancements or depletions of the belts. Precipitation into the atmosphere has been shown to be an important loss process for energetic particles in Earth's magnetosphere, but when, where, and how much precipitation contributes remain open questions. While radiation belt diffusion models can now reproduce observed acceleration events quite accurately, radiation belt depletion events are often less well-captured. Quantification of precipitation loss, as well as understanding of the physical mechanisms producing it, is thus critical to our understanding of the dynamics of the outer radiation belt.","PeriodicalId":365284,"journal":{"name":"2021 USNC-URSI Radio Science Meeting (USCN-URSI RSM)","volume":"555 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-08-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133599152","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-08-09DOI: 10.23919/USNC-URSIRSM52661.2021.9552360
C. Jeffery, Yash Mehta, E. Nelson
Radio signals are strongly impacted by natural and artificial ionospheric disturbances which can be challenging to model. This is especially true of D- Region chemistry which is affected from below by shocks, acoustic-gravity waves and thunderstorm electric fields, and from above by solar x-rays, high-energy protons, and precipitating electrons. Detailed chemistry schemes have been developed by various research groups, with many 10s of species and many 100s of reactions, that have been used to calculate RF absorption during geomagnetic events. In contrast, advanced studies of VLF signal propagation typically employ reduced D-Region chemistry schemes [1]–[2], e.g., the four species Glukhov-Pasko-Inan scheme [3], that rely upon simplified parameterizations of electron attachment, detachment and recombination.
{"title":"Sensitivity of FDTD modeling of VLF Signals to D-Region Chemistry: Quiescent & Disturbed Conditions","authors":"C. Jeffery, Yash Mehta, E. Nelson","doi":"10.23919/USNC-URSIRSM52661.2021.9552360","DOIUrl":"https://doi.org/10.23919/USNC-URSIRSM52661.2021.9552360","url":null,"abstract":"Radio signals are strongly impacted by natural and artificial ionospheric disturbances which can be challenging to model. This is especially true of D- Region chemistry which is affected from below by shocks, acoustic-gravity waves and thunderstorm electric fields, and from above by solar x-rays, high-energy protons, and precipitating electrons. Detailed chemistry schemes have been developed by various research groups, with many 10s of species and many 100s of reactions, that have been used to calculate RF absorption during geomagnetic events. In contrast, advanced studies of VLF signal propagation typically employ reduced D-Region chemistry schemes [1]–[2], e.g., the four species Glukhov-Pasko-Inan scheme [3], that rely upon simplified parameterizations of electron attachment, detachment and recombination.","PeriodicalId":365284,"journal":{"name":"2021 USNC-URSI Radio Science Meeting (USCN-URSI RSM)","volume":"1 2","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-08-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134290532","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-08-09DOI: 10.23919/USNC-URSIRSM52661.2021.9552363
Z. Xia, Lunjin Chen
Whistler mode waves are a right-hand circularly polarized electromagnetic waves in the very low frequency (VLF) range, which can be excited and propagate in the region through the Earth's atmosphere to the magnetosphere. Typical examples of whistler mode waves include chorus, plasmaspheric hiss, lightning generated whistler (LGW), VLF waves ejected by ground transmitters. The whistler mode wave can interact with energetic electrons and plays an important role in both electron loss and acceleration in the magnetosphere.
{"title":"Whistler Waves above Lower Hybrid Frequency in the Ionosphere and their Counterpart in the Magnetosphere","authors":"Z. Xia, Lunjin Chen","doi":"10.23919/USNC-URSIRSM52661.2021.9552363","DOIUrl":"https://doi.org/10.23919/USNC-URSIRSM52661.2021.9552363","url":null,"abstract":"Whistler mode waves are a right-hand circularly polarized electromagnetic waves in the very low frequency (VLF) range, which can be excited and propagate in the region through the Earth's atmosphere to the magnetosphere. Typical examples of whistler mode waves include chorus, plasmaspheric hiss, lightning generated whistler (LGW), VLF waves ejected by ground transmitters. The whistler mode wave can interact with energetic electrons and plays an important role in both electron loss and acceleration in the magnetosphere.","PeriodicalId":365284,"journal":{"name":"2021 USNC-URSI Radio Science Meeting (USCN-URSI RSM)","volume":"14 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-08-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132656999","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-08-09DOI: 10.23919/USNC-URSIRSM52661.2021.9552355
Avinash Sharma, M. Kurum, R. Lang
The effect of dew in a vegetation canopy on the L-Band thermal emissions is studied. An approximate electromagnetic model for dew on a leaf is used in conjunction with a Radiative Transfer to compute the thermal emissions. The dew is modeled as a thin uniform layer covering the entire surface of the leaf. From this model, the scattering amplitudes and phase functions are computed. These are then used in both the τ-ω model and a first-order Radiative Transfer model to compute the emissivity from the vegetation canopy in the presence of various amounts of dew. The τ-ω model predicts a decrease in emissivity as the dew amount increases. However, the inclusion of first-order scattering predicts the opposite relationship, where an increase in dew results in an increase in emissivity.
{"title":"The effect of dew on L- Band emissions from a vegetation canopy","authors":"Avinash Sharma, M. Kurum, R. Lang","doi":"10.23919/USNC-URSIRSM52661.2021.9552355","DOIUrl":"https://doi.org/10.23919/USNC-URSIRSM52661.2021.9552355","url":null,"abstract":"The effect of dew in a vegetation canopy on the L-Band thermal emissions is studied. An approximate electromagnetic model for dew on a leaf is used in conjunction with a Radiative Transfer to compute the thermal emissions. The dew is modeled as a thin uniform layer covering the entire surface of the leaf. From this model, the scattering amplitudes and phase functions are computed. These are then used in both the τ-ω model and a first-order Radiative Transfer model to compute the emissivity from the vegetation canopy in the presence of various amounts of dew. The τ-ω model predicts a decrease in emissivity as the dew amount increases. However, the inclusion of first-order scattering predicts the opposite relationship, where an increase in dew results in an increase in emissivity.","PeriodicalId":365284,"journal":{"name":"2021 USNC-URSI Radio Science Meeting (USCN-URSI RSM)","volume":"10 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-08-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123732355","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-08-09DOI: 10.23919/USNC-URSIRSM52661.2021.9552373
A. Johnson, J. Sample, D. Klumpar, H. Spence, I. Linscott, D. Lauben, U. Inan
FIREBIRD-II (Focused Investigations of Relativistic Electron Burst Intensity, Range, and Dynamics) is a National Science Foundation CubeSat mission exploring relativistic electron microbursts. The mission consists of two identically instrumented CubeSats that were launched into a near polar orbit on January 31, 2015. Each spacecraft has two solid state detectors that return high cadence (10's of ms) measurements of the electron population. Both units operated continuously for almost 5 years and one unit continues to operate and return high quality data over 6 years after launch.
{"title":"The FIREBIRD-II CubeSat Mission","authors":"A. Johnson, J. Sample, D. Klumpar, H. Spence, I. Linscott, D. Lauben, U. Inan","doi":"10.23919/USNC-URSIRSM52661.2021.9552373","DOIUrl":"https://doi.org/10.23919/USNC-URSIRSM52661.2021.9552373","url":null,"abstract":"FIREBIRD-II (Focused Investigations of Relativistic Electron Burst Intensity, Range, and Dynamics) is a National Science Foundation CubeSat mission exploring relativistic electron microbursts. The mission consists of two identically instrumented CubeSats that were launched into a near polar orbit on January 31, 2015. Each spacecraft has two solid state detectors that return high cadence (10's of ms) measurements of the electron population. Both units operated continuously for almost 5 years and one unit continues to operate and return high quality data over 6 years after launch.","PeriodicalId":365284,"journal":{"name":"2021 USNC-URSI Radio Science Meeting (USCN-URSI RSM)","volume":"52 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-08-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126811817","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-08-09DOI: 10.23919/USNC-URSIRSM52661.2021.9552377
S. Ronda, C. Oliver, O. Martínez, J. M. Miranda
The study of dispersion phenomena in electromagnetic waves reflected by lossy materials at infrared and lower frequencies is a topic which finds a number of applications in microwave and optical engineering. Metamaterials and metasurfaces, for example, are dispersive media which feature unique abilities to control electromagnetic fields, and this has stimulated the development of new and promising applications in the areas of antenna technology, Communications and Electromagnetic Compatibility. A number of other applications can also be found in Optics and Optoelectronic device technologies. From the educational point of view, the learning process of the fundamental principles behind these topics is challenging for both undergraduate and doctoral students. This is in part due to the need of conciliating concepts and mathematical developments that are covered in both Optics and Electromagnetics courses from different perspectives and nomenclature.
{"title":"Teaching Dispersion Effects in Waves Reflected by Lossy Materials: The Optics vs. Electromagnetics Approach","authors":"S. Ronda, C. Oliver, O. Martínez, J. M. Miranda","doi":"10.23919/USNC-URSIRSM52661.2021.9552377","DOIUrl":"https://doi.org/10.23919/USNC-URSIRSM52661.2021.9552377","url":null,"abstract":"The study of dispersion phenomena in electromagnetic waves reflected by lossy materials at infrared and lower frequencies is a topic which finds a number of applications in microwave and optical engineering. Metamaterials and metasurfaces, for example, are dispersive media which feature unique abilities to control electromagnetic fields, and this has stimulated the development of new and promising applications in the areas of antenna technology, Communications and Electromagnetic Compatibility. A number of other applications can also be found in Optics and Optoelectronic device technologies. From the educational point of view, the learning process of the fundamental principles behind these topics is challenging for both undergraduate and doctoral students. This is in part due to the need of conciliating concepts and mathematical developments that are covered in both Optics and Electromagnetics courses from different perspectives and nomenclature.","PeriodicalId":365284,"journal":{"name":"2021 USNC-URSI Radio Science Meeting (USCN-URSI RSM)","volume":"159 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-08-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131172105","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-08-09DOI: 10.23919/USNC-URSIRSM52661.2021.9552362
M. H. Akhtar, D. Klymyshyn, A. A. Qureshi
A dual-band artificial metal grid dielectric resonator antenna (GDRA) operating at millimeter wave frequencies is presented. The embedded metal grids increase the effective permittivity of base dielectric composed of poly-methyl methacrylate (PMMA) and their I-shape allows for two unique modes. Simulation results demonstrate that the GDRA resonates at 28 and 38 GHz with 6.96 and 6.99 dBi gains, respectively. The GDRA can be tuned to operate as a lower single band, upper single band or as a dual-band antenna by adjusting the feed line dimension.
{"title":"Single-Fed Dual-Band Metal Grid Artificial Dielectric Antenna for Millimeter Wave Applications","authors":"M. H. Akhtar, D. Klymyshyn, A. A. Qureshi","doi":"10.23919/USNC-URSIRSM52661.2021.9552362","DOIUrl":"https://doi.org/10.23919/USNC-URSIRSM52661.2021.9552362","url":null,"abstract":"A dual-band artificial metal grid dielectric resonator antenna (GDRA) operating at millimeter wave frequencies is presented. The embedded metal grids increase the effective permittivity of base dielectric composed of poly-methyl methacrylate (PMMA) and their I-shape allows for two unique modes. Simulation results demonstrate that the GDRA resonates at 28 and 38 GHz with 6.96 and 6.99 dBi gains, respectively. The GDRA can be tuned to operate as a lower single band, upper single band or as a dual-band antenna by adjusting the feed line dimension.","PeriodicalId":365284,"journal":{"name":"2021 USNC-URSI Radio Science Meeting (USCN-URSI RSM)","volume":"288 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-08-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123232869","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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