Low Velocity Impact and RF Response of 3D Printed Heterogeneous Structures

Three-dimensional (3D) printing, a form of Additive manufacturing (AM), is currently being explored to design materials or structures with required Electro-Mechanical-Physical properties. Microstrip patch antennas with a tunable radio-frequency (RF) response are a great candidate for 3D printing process. Due to the nature of extrusion based layered fabrication; the processed parts are of three-layer construction having inherent heterogeneity that affects structural and functional response. The purpose of this study is to identify the relationship between the anisotropy in dielectric properties of AM fabricated acrylonitrile butadiene styrene (ABS) substrates in the RF domain and resonant frequencies of associated patch antennas and also to identify the response of the antenna before and after a low velocity impact. In this study, ANSYS high frequency structure simulator (HFSS) is utilized to analyze RF response of patch antenna and compared with the experimental work. First, a model with dimensions of 50 mm x 50 mm x 5 mm is designed in Solidworks and three separate sets of samples are fabricated at three different machine preset fill densities using an extrusion based 3D printer LulzBot TAZ 5. The actual solid volume fraction of each set of samples is measured using a 3D X-ray computed tomography microscope. The printed materials appeared to exhibit anisotropy such that the thickness direction dielectric properties are different from the planar properties. The experimental resonant frequency for one fill-density is combined with ANSYS-HFSS simulation results to estimate the bulk dielectric constant of ABS and the equivalent dielectric properties in planar and thickness directions. The bulk dielectric properties are then used in HFSS models for other two fill densities and the simulated results appear to match reasonably well with experimental findings. The similar HFSS modeling scheme was adopted to understand the effect of material heterogeneity on RF response. In addition, a hybrid structure with dimensions of 50 mm x 50 mm x 20 mm is designed with the first 15 mm thickness being a cellular BCC structure and the other 5 mm being a solid cuboid. These samples are printed on an extrusion based 3D printer Stratasys uPrint using ABS. A patch antenna is embedded at the interface of the solid and the cellular structure. Both ABAQUS finite element modeling and experimental methods are used to understand the load-displacement and the energy absorption behavior of the hybrid structure under low velocity impact loadings. The hybrid structure is impacted on both sides to investigate the damage tolerance capabilities of embedded electronic components

Auto-economics: the Tata Nano

The Nano has made news worldwide since its unveiling in January of 2008. This car is a milestone in the history of automobile manufacturing. As economists, we have found the Nano extremely interesting as it is expected to have far reaching effects not only in the automobile industry, but also spark the aspirations of millions of people for owning a car that were deprived of this pleasure prior to the launch of Nano

Low Velocity Impact and RF Response of 3D Printed Heterogeneous Structures

Three-dimensional (3D) printing, a form of Additive manufacturing (AM), is currently being explored to design materials or structures with required Electro-Mechanical-Physical properties. Microstrip patch antennas with a tunable radio-frequency (RF) response are a great candidate for 3D printing process. Due to the nature of extrusion based layered fabrication; the processed parts are of three-layer construction having inherent heterogeneity that affects structural and functional response. The purpose of this study is to identify the relationship between the anisotropy in dielectric properties of AM fabricated acrylonitrile butadiene styrene (ABS) substrates in the RF domain and resonant frequencies of associated patch antennas and also to identify the response of the antenna before and after a low velocity impact. In this study, ANSYS high frequency structure simulator (HFSS) is utilized to analyze RF response of patch antenna and compared with the experimental work. First, a model with dimensions of 50 mm x 50 mm x 5 mm is designed in Solidworks and three separate sets of samples are fabricated at three different machine preset fill densities using an extrusion based 3D printer LulzBot TAZ 5. The actual solid volume fraction of each set of samples is measured using a 3D X-ray computed tomography microscope. The printed materials appeared to exhibit anisotropy such that the thickness direction dielectric properties are different from the planar properties. The experimental resonant frequency for one fill-density is combined with ANSYS-HFSS simulation results to estimate the bulk dielectric constant of ABS and the equivalent dielectric properties in planar and thickness directions. The bulk dielectric properties are then used in HFSS models for other two fill densities and the simulated results appear to match reasonably well with experimental findings. The similar HFSS modeling scheme was adopted to understand the effect of material heterogeneity on RF response. In addition, a hybrid structure with dimensions of 50 mm x 50 mm x 20 mm is designed with the first 15 mm thickness being a cellular BCC structure and the other 5 mm being a solid cuboid. These samples are printed on an extrusion based 3D printer Stratasys uPrint using ABS. A patch antenna is embedded at the interface of the solid and the cellular structure. Both ABAQUS finite element modeling and experimental methods are used to understand the load-displacement and the energy absorption behavior of the hybrid structure under low velocity impact loadings. The hybrid structure is impacted on both sides to investigate the damage tolerance capabilities of embedded electronic components

Effect of Heterogeneity in Additively Manufactured Dielectric Structures on RF Response of Microstrip Patch Antennas

Microstrip patch antennas with a tunable radiofrequency (RF) response are a great candidate for additive manufacturing (AM) process. First, three separate sets of ABS samples were created at three different machine preset fill densities using an extrusion based 3D printer. Once fabricated, actual solid volume fraction of each set of samples was measured using a 3D X‐ray computed tomography microscope. It is observed that the factory preset fill‐density values are only applied to the core region and actual solid volume fractions for each sample set are different from printer‐preset values. Also, the printed materials appeared to exhibit anisotropy such that the thickness direction dielectric properties are different from the in‐plane properties (planar isotropy). Microstrip patch antennas created on the AM fabricated ABS were tested for resonant frequencies using a vector network analyzer (VNA). The measured resonant frequencies combined with ANSYS‐HFSS simulation were used to estimate bulk dielectric constant of ABS and equivalent dielectric properties in planar and thickness directions. It is observed that the antenna resonant frequency decreases with an increase in core solid volume fraction. Also, in‐plane permittivity appeared to have minimal effect on antenna resonant frequency, while the thickness direction properties have substantial effects

Effect of Heterogeneity in Additively Manufactured Dielectric Structures on RF Response of Microstrip Patch Antennas

Microstrip patch antennas with a tunable radiofrequency (RF) response are a great candidate for additive manufacturing (AM) process. First, three separate sets of ABS samples were created at three different machine preset fill densities using an extrusion based 3D printer. Once fabricated, actual solid volume fraction of each set of samples was measured using a 3D X‐ray computed tomography microscope. It is observed that the factory preset fill‐density values are only applied to the core region and actual solid volume fractions for each sample set are different from printer‐preset values. Also, the printed materials appeared to exhibit anisotropy such that the thickness direction dielectric properties are different from the in‐plane properties (planar isotropy). Microstrip patch antennas created on the AM fabricated ABS were tested for resonant frequencies using a vector network analyzer (VNA). The measured resonant frequencies combined with ANSYS‐HFSS simulation were used to estimate bulk dielectric constant of ABS and equivalent dielectric properties in planar and thickness directions. It is observed that the antenna resonant frequency decreases with an increase in core solid volume fraction. Also, in‐plane permittivity appeared to have minimal effect on antenna resonant frequency, while the thickness direction properties have substantial effects

K and Rupela : Evaluation of actinomycete isolates obtained from herbal vermicompost for the biological control of Fusarium wilt of chickpea. International crop research institute for semiarid tropics (ICRISAT),

ABSTRACT A total of 137 actinomycetes cultures, isolated from 25 different herbal vermicomposts, were characterized for their antagonistic potential against Fusarium oxysporum f. sp. ciceri (FOC) by dual-culture assay. Of the isolates, five most promising FOC antagonistic isolates were characterized for the production of siderophore, cellulase, protease, hydrocyanic acid (HCN), indole acetic acid (IAA) and antagonistic potential against Rhizoctonia bataticola, which causes dry root rot in chickpea (three strains viz. RB-6, RB-24 and RB-115) and sorghum (one strain). All of the five FOC antagonistic isolates produced siderophore and HCN, four of them (except KAI-90) produced IAA, KAI-32 and KAI-90 produced cellulase and CAI-24 and CAI-127 produced protease. In the dual-culture assay, three of the isolates, CAI-24, KAI-32 and KAI-90, also inhibited all three strains of R. bataticola in chickpea, while two of them (KAI-32 and KAI-90) inhibited the lonely strain in sorghum. When the FOC antagonistic isolates were evaluated further for their antagonistic potential in the greenhouse and wilt-sick field conditions on chickpea, 45-76% and 4-19% reduction of disease incidence were observed, respectively compared to the control. The sequences of 16S rDNA gene of the isolates CAI-24, CAI-121, CAI-127, KAI-32 and KAI-90 were matched with Streptomyces tsusimaensis, S. caviscabies, S. setonii, S. africanus and an identified species of Streptomyces, respectively using the BLAST searching. This study indicated that the selected actinomycete isolates have the potential for biological control of Fusarium wilt disease in chickpea

Book of Abstracts of the 2nd International Conference on Applied Mathematics and Computational Sciences (ICAMCS-2022)

It is a great privilege for us to present the abstract book of ICAMCS-2022 to the authors and the delegates of the event. We hope that you will find it useful, valuable, aspiring, and inspiring. This book is a record of abstracts of the keynote talks, invited talks, and papers presented by the participants, which indicates the progress and state of development in research at the time of writing the research article. It is an invaluable asset to all researchers. The book provides a permanent record of this asset. Conference Title: 2nd International Conference on Applied Mathematics and Computational SciencesConference Acronym: ICAMCS-2022Conference Date: 12-14 October 2022Conference Organizers: DIT University, Dehradun, IndiaConference Mode: Online (Virtual