Devyn Duryea;Nicholas McKibben;Jacob Manzi;Taylor Brennan;Harish Subbaraman;David Estrada;Nirmala Kandadai; 《Advanced Engineering Materials》2024,26(10):2400721

Flexible and printed electronics have become increasingly popular as they make possible the production of flexible, low-cost, multifunction devices that are unachievable through traditional manufacturing methods. The printed films are significantly impacted and thus limited by the existing ink production process. Herein, an alternate technique of generating high-quality titanium dioxide (TiO2) nanoparticle ink compatible with aerosol jet printing using laser ablation synthesis in solution (LASiS) is showcased. Dynamic light scattering data and transmission electron microscopy confirm the particle size distribution. UV–vis measurements are performed, and the Beer–Lambert relationship is used to determine the concentration of the generated ink. The inks generated at two different repetition rates are compared: 200 kHz and 1 MHz. X-Ray diffraction analysis of the aerosol jet printed thin film post-thermal sintering confirms the grain size and phase purity of the printed thin films. This work demonstrates the effectiveness of the LASiS technique in producing printable nanoparticle inks with little-to-no postprocessing.  相似文献   

    

Harish Kumar  Avneesh Kumar Gehlaut  Himanshu Gupta  Ankur Gaur  Suantak Kamsonlian  Devender Kumar 《Polymer Composites》2021,42(8):3899-3910

This study focuses on the synthesis of aluminum oxide nanoparticles (AlO-NPs) hydrogel through in situ method and formation of biopolymer nanocomposite film. UV–Vis spectroscopy, Fourier transform infrared spectroscopy, scanning electron microscopy, transmission electron microscopy (TEM), particle size analyzer, and energy dispersive X-ray spectrum were performed for the characterization of AlO-NPs. TEM micrograph demonstrates the presence of AlO-NPs in the range of 50–100 nm in the hydrogel network made from sugarcane bagasse carboxymethyl cellulose (SB-CMC) and synthetic carboxymethyl cellulose (CMC). The successful absorptions peak at 210 nm while conducting UV–Vis spectroscopy suggests existence of AlO-NPs. The antibacterial properties of AlO-NPs were analyzed using the disc plate diffusion technique against Gram-negative bacteria: Escherichia coli (ATCC 433); and Gram-positive bacteria: Bacillus subtilis (ATCC 1688). AlO-NPs present in CMCs films reduce moisture content, solubility; elongation at break and increases films' tensile strength.  相似文献   

    

G. Harish Kumar  P. Trinatha Rao 《Concurrency and Computation》2023,35(1):e7416

This paper is to plan for the development of energy-efficient MIMO-OFDM mobile multimedia communication systems using the intelligent meta-heuristic approach. This model is concentrated on solving the multi-channel optimization problem. Recent research work is focused on single-channel optimization problems, and hence the conversion of multi-channel optimization problems into single-channel optimization problems is considered the challenging point in this research. In the proposed MIMO-OFDM method for mobile multimedia communication systems, the channel-matrix Singular Value Decomposition (SVD) method is used for implementing the sub-channel grouping scheme, which has simplified the multichannel problem to a multi-target single-channel optimization problem. In this optimization problem, the transmission power-allocation threshold is optimized for attaining the objective function of maximization of energy efficiency. A hybridized optimization algorithm named Hybrid Fruit Fly-based Salp Swarm Optimization (HFF-SSO) is utilized for energy optimization in the MIMO-OFDM mobile multimedia communication system. This hybrid algorithm has reached an energy-efficient system with a high convergence rate, which is proved by the comparison over the conventional systems.  相似文献   

    

Yixuan Wang  Liping Yuan  Harish Garg  Ali Bagherinia  Parvïn Hamïd  Kim-Hung Pho  Zulkefli Mansor 《计算机、材料和连续体（英文）》2021,67(1):369-392

In order to improve performance and robustness of clustering, it is proposed to generate and aggregate a number of primary clusters via clustering ensemble technique. Fuzzy clustering ensemble approaches attempt to improve the performance of fuzzy clustering tasks. However, in these approaches, cluster (or clustering) reliability has not paid much attention to. Ignoring cluster (or clustering) reliability makes these approaches weak in dealing with low-quality base clustering methods. In this paper, we have utilized cluster unreliability estimation and local weighting strategy to propose a new fuzzy clustering ensemble method which has introduced Reliability Based weighted co-association matrix Fuzzy C-Means (RBFCM), Reliability Based Graph Partitioning (RBGP) and Reliability Based Hyper Clustering (RBHC) as three new fuzzy clustering consensus functions. Our fuzzy clustering ensemble approach works based on fuzzy cluster unreliability estimation. Cluster unreliability is estimated according to an entropic criterion using the cluster labels in the entire ensemble. To do so, the new metric is defined to estimate the fuzzy cluster unreliability; then, the reliability value of any cluster is determined using a Reliability Driven Cluster Indicator (RDCI). The time complexities of RBHC and RBGP are linearly proportional with the number of data objects. Performance and robustness of the proposed method are experimentally evaluated for some benchmark datasets. The experimental results demonstrate efficiency and suitability of the proposed method.  相似文献   

    

Bharath Reddy Gudibandi  Harish Adhithya Murugan  Sriram Kumar Dhamodharan 《国际射频与微波计算机辅助工程杂志》2020,30(5)

In this article, miniaturization of the wire monopole antenna with the help of high refractive index (HRI) metamaterial is presented. For the first time, HRI medium is realized by using the array of single ring split ring resonator. By surrounding the wire monopole with the array of SR‐SRRs, the effective wavelength is squeezed in the vicinity of the near field dominance. By the loading of the monopole with such an HRI medium, the size of the antenna is reduced from 29.5 to 16 mm, without any deformation in the current distribution and radiation pattern corresponding to the fundamental resonance. The simulated and measured results are agreed to the same.  相似文献   

    

Monika Singh  Navneet Kumar  Santanu Dwari  Harish Parthasarathy  Pradyot Kala 《国际射频与微波计算机辅助工程杂志》2020,30(7)

A novel zeroth‐order resonator (ZOR) meta‐material (MTM) antenna with dual‐band is suggested using compound right/left handed transmission line as MTM. In this article, suggested antenna consists of patch through series gap, two meander line inductors, and two circular stubs. The MTM antenna is compact in size which shows dual‐band properties with first band centered at 2.47 GHz (2.05‐2.89 GHz) and second band is centered at 5.9 GHz (3.70‐8.10 GHz) with impedance bandwidth of (S₁₁ < ? 10 dB) 34.69% and 72.45%, respectively. At ZOR mode (2.35 GHz), the suggested antenna has overall dimension of 0.197λ_o × 0.07λ_o × 0.011λ_o with gain of 1.65 dB for ZOR band and 3.35 dB for first positive order resonator band which covers the applications like Bluetooth (2.4 GHZ), TV/Radio/Data (3.700‐6.425 GHz), WLAN (5‐5.16 GHz), C band frequencies (5.15‐5.35, 5.47‐5.725, or 5.725‐5.875 GHz) and satellite communication (7.25‐7.9 GHz). The radiation patterns of suggested structure are steady during the operating band for which sample antenna has been fabricated and confirmed experimentally. It exhibits novel omnidirectional radiation characteristics in phi = 0° plane with lower cross‐polarization values.  相似文献   

    

Harish Adhithya Murugan  Gudibandi Bharath Reddy  Sriram Kumar Dhamodharan 《国际射频与微波计算机辅助工程杂志》2020,30(10)

A coaxial‐fed tri‐band zeroth‐order resonance (ZOR) circularly polarized antenna with higher gains for all the excited ZORs is designed and analyzed in this paper. Epsilon negative transmission line (ENG TL) and pseudo‐open termination (P‐OT) unit cells with different series capacitances (C_S and C_S1 ) resonate shunt ZOR (f_sh ) and two series ZORs (f_se and f_se1 ), respectively. Asymmetric unit cell concept is applied to ENG‐TL and P‐OT unit cells to create vertical and horizontal components, and the 90° phase shift is provided by the ZOR, resulting in circular polarization (CP). Left‐hand CP (LHCP) is achieved by creating two 90° right bends to the extended stubs in ENG TL and P‐OT unit cells. Higher gains for all the excited ZORs are achieved by shifting the shorting pins of ENG TL and P‐OT unit cells far away from the center position. After fabrication, the measured resonances occur at 4.64 GHz (f_sh ), 4.04 GHz (f_se ), and 3.86 GHz (f_se1 ) with fractional bandwidths of 1.62%, 1.73%, and 1.6%, respectively. The measured LHCP peak gains are 4.05 dBic (f_sh ), 3.85 dBic (f_se ), and 3.94 dBic (f_se1 ). The average axial ratio obtained is less than 3‐dB in the 10‐dB fractional bandwidth of the proposed antenna.  相似文献   

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Harish Garg  Nancy 《IEEE/CAA Journal of Automatica Sinica》2020,7(2):546-558

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Paresh Parekh  Sayaka Ohno  Shin‐ichi Yusa  Chao Lv  Binyang Du  Debes Ray  Vinod Kumar Aswal  Pratap Bahadur 《Polymer International》2020,69(11):1113-1121

Poly(ethylene oxide)–poly(propylene oxide)–poly(ethylene oxide) (PEO–PPO–PEO) triblock copolymer (Pluronic F127) was modified by introducing poly(N‐isopropylacrylamide) (PNIPAM) at both the PEO ends, and the pentablock copolymer (PNIPAM₄₁–F127–PNIPAM₄₁, PN41) so prepared was characterized using gel permeation chromatography and ¹H NMR spectroscopy. The degree of polymerization of NIPAM blocks at the two ends was 41. The solution behaviour and microstructure of PN41 aggregates in water were examined using UV–visible spectroscopy, micro‐differential scanning calorimetry and small‐angle neutron scattering (SANS) and compared with F127. Two lower critical solution temperatures (LCSTs) were observed for the pentablock copolymer, corresponding to PPO and PNIPAM blocks, respectively. The adsorption of PN41 on thiol‐grafted hydrophobic gold surfaces at various temperatures was investigated using a quartz crystal microbalance. It was found that the adsorption behaviour and mechanism of PN41 were mainly determined by the interactions of the pentablock copolymers with different chain conformations in dilute aqueous solutions at various temperatures. SANS measurements were used to determine the temperature‐dependent structural evolution of polymer micelles in aqueous solution. A NOESY study revealed that above the LSCT of PNIPAM, the interaction of PPO and PNIPAM protons increases and the distance between PPO and PNIPAM decreases. © 2019 Society of Chemical Industry  相似文献   

    

Asma Ayaz  Wajid Zaman  Fazal Ullah  Saddam Saqib  Shayan Jamshed  Saraj Bahadur  Abdul Shakoor  Bushra Arshad 《Microscopy research and technique》2020,83(1):81-87

In all over the world, herbal drugs are usually adulterated with similar species or varieties due to incorrect identification. Most of herbal products devoid purity and quality, therefore an attempt was carried out to identify plant species and authenticate its herbal drug products from Mentha suaveolens. Microscopy tools provide an excellent platform to identify plants at species level. In this study, microscopic and pharmacokinetic parameters of M. suaveolens were observed. Plant species were collected from high diverse areas of Northern Pakistan. Macro and micro‐morphology including palynology and anatomical features were analyzed to study M. suaveolens. Species characteristics were studied, while implementing microscopic techniques for the delimitation and identification of the species. Traditionally Mentha species are used to cure several diseases that is, digestive disorders, respiratory disorders. Micromorphology (stem, leaves, flowers structure, length etc.), palynology (shape, size of pollen etc.), and anatomical characters (types of stomata, epidermal cell shape, and trichomes) were studied. Micromorphology and anatomical characters were of great interest and significance to discuss the taxonomy of the species. Taxonomic characters were studied to characterize and authenticate the species. The aim of the present study is to observe in detail the taxonomic identification of the species in term of morphology, palynology, and foliar epidermal anatomy for the correct identification along with their medicinal uses in the area.  相似文献