Article
Multidisciplinary Sciences
Mohammad Mashayekhi, Pooria Kabiri, Amir Saman Nooramin, Mohammad Soleimani
Summary: This article investigates the design of a reconfigurable multi-band patch antenna based on graphene for terahertz applications. The study evaluates the dependence of the antenna radiation characteristics on its geometric parameters and graphene properties, and explores the use of a deep neural network to predict antenna parameters. The results show high accuracy and negligible errors, highlighting the potential applications of the proposed antenna in the THz frequency band.
SCIENTIFIC REPORTS
(2023)
Article
Physics, Applied
Hadi Soleimani, Homayoon Oraizi
Summary: This paper presents the concept, analysis, and equivalent circuit of a phoenix graphene patch (PGP) unit cell for the first time and designs a reflectarray antenna and a programmable vortex beam reflectarray based on this cell. By changing the element dimensions in the cell and the chemical potential of the graphene sheet, the required phases can be easily realized. The designed antennas achieve high gain and radiation efficiency.
JOURNAL OF PHYSICS D-APPLIED PHYSICS
(2021)
Article
Engineering, Electrical & Electronic
Govind Kumar Pandey, Rama Rao Thipparaju, Shyamal Mondal
Summary: This research paper presents the design of an octagonal shaped graphene based terahertz patch antenna for indoor communications. A single graphene layer with a thickness of 10 nm is layered over a quartz substrate with a thickness of 100 μm to enhance the effectiveness of the MIMO antenna. The suggested MIMO antenna achieves a bandwidth of 113 GHz over a frequency range of 0.257-0.370 THz, with a mutual coupling coefficient of less than -15 dB. The diversity performance of the designed THz MIMO antenna is analyzed, and the obtained diversity matrices include diversity gain, envelope correlation coefficient, channel capacity loss, and total active reflection coefficient.
OPTICAL AND QUANTUM ELECTRONICS
(2023)
Article
Optics
Jemima G. Nissiyah, M. Ganesh Madhan
Summary: The plasmonic resonator antenna is capable of operating in triple or even quadruple band modes by adjusting the chemical potential of the graphene layer and modifying the substrate thickness. The antenna demonstrates varying levels of gain and directivity at different frequencies, with the possibility of beam steering due to the effect of chemical potential on the radiation pattern.
Article
Computer Science, Information Systems
Theodoros N. Kapetanakis, Christos D. Nikolopoulos, Konstantinos Petridis, Ioannis O. Vardiambasis
Summary: Textile patch antennas of various shapes and materials were designed and fabricated with optimized characteristics for wearable applications, demonstrating excellent performance.
Article
Multidisciplinary Sciences
Mohamed Mamdouh M. Ali, Shoukry Shams, Mahmoud Elsaadany, Ghyslain Gagnon, Ke Wu
Summary: This paper introduces the use of graphene to implement a reconfigurable printed ridge gap waveguide structure in the terahertz frequency range for the first time. This guiding structure exhibits low loss and is suitable for both millimeter and terahertz wave applications.
SCIENTIFIC REPORTS
(2022)
Article
Optics
Md. Abdul Kaium Khan, Md. Ibrahim Ullah, Mohammad Abdul Alim
Summary: Graphene-based antennas show potential in high-frequency microwave applications, operating in the terahertz communication band. A proposed high-gain, ultrawide-band antenna with photonic crystal and dielectric grating has an impedance bandwidth of 9.552 THz and operates from 0.448 THz to 10 THz. The antenna exhibits a maximum gain of 21.22 dB and a radiation efficiency of 93.23%, while the periodicity and dimensions of the photonic crystal impact performance more than the crystal's shape.
Article
Engineering, Electrical & Electronic
Victor Dmitriev, Nilton R. N. M. Rodrigues, Rodrigo M. S. de Oliveira, Rodrigo R. Paiva
Summary: A rectangular graphene loop antenna for terahertz band was proposed and analyzed in this study. The antenna showed optimal performance around the second resonance frequency and exhibited different total efficiency and bandwidth on various semi-infinite substrates. The loop antenna presented higher efficiency and bandwidth compared to graphene dipole antenna.
IEEE TRANSACTIONS ON ANTENNAS AND PROPAGATION
(2021)
Article
Physics, Multidisciplinary
Saeed Fakhte, Mohammad Mahdi Taskhiri
Summary: This article presents the design of a terahertz antenna that can reconfigure its polarization using graphene's anisotropic properties. The antenna can switch between linear and circular polarizations by applying a DC magnetic flux to change the graphene conductivity tensor. The antenna design utilizes a magnetostatic field to achieve reconfiguration, a method that has not been previously documented.
Article
Chemistry, Physical
S. M. Shamim, Sudipta Das, Md. Arafat Hossain, Boddapati Taraka Phani Madhav
Summary: This article investigates a graphene-based hexagonal microstrip patch antenna with U-shaped and elliptical-shaped slots, aiming to enhance radiation performance and provide an impedance bandwidth ranging from 0.68 to 1.63 THz. Comparative studies reveal significant improvements in gain and directivity for the elliptical slot-loaded structure. The proposed antennas have potential applications in ultra-wideband terahertz scenarios such as bio-imaging, spectroscopy, explosive detection, medical diagnoses, communication, and weather monitoring.
Article
Optics
A. Anisha, D. Sriram Kumar
Summary: This article presents the design of an optically transparent patch antenna based on Ta(4)c(3) MXene for operation at 800 GHz. The antenna achieves broad impedance bandwidth and better radiation performances, and its utilization in the terahertz band is discussed by comparing it with existing transparent antennas.
Article
Engineering, Electrical & Electronic
Khatereh Moradi, Ali Pourziad, Saeid Nikmehr
Summary: A hybrid of metal and graphene reconfigurable antenna is proposed for THz band applications. The antenna can be tuned by graphene to achieve frequency and pattern reconfigurability.
AEU-INTERNATIONAL JOURNAL OF ELECTRONICS AND COMMUNICATIONS
(2022)
Article
Materials Science, Multidisciplinary
Meisam Esfandiyari, Ali Lalbakhsh, Saughar Jarchi, Mohsen Ghaffari-Miab, Hamideh Noori Mahtaj, Roy B. V. B. Simorangkir
Summary: This paper presents a novel tunable graphene-based bandstop filter/antenna-sensor. The structure combines filtering and high-gain radiation performance. The conductivity of graphene and its structural parameters are studied to optimize the component performance.
MATERIALS & DESIGN
(2022)
Article
Engineering, Electrical & Electronic
Saeed Fakhte, Mohammad Mahdi Taskhiri
Summary: A dual-band terahertz rectangular dielectric resonator antenna (DRA) based on graphene is proposed in this work. The resonant frequencies of the antenna's TE111y and TE113y modes can be tuned by varying the chemical potential of the graphene, which acts as an impedance surface. An approximate formula for obtaining the resonant frequency of the graphene-loaded DRA is also presented for the first time, and it shows good agreement with simulation results.
OPTICAL AND QUANTUM ELECTRONICS
(2022)
Article
Engineering, Electrical & Electronic
Saeed Fakhte, Mohammad Mahdi Taskhiri
Summary: In this article, a magnetically biased graphene is used to create a terahertz antenna that can reconfigure the polarization of the radiation pattern. By altering the direction of the applied magnetic field, the polarization can be shifted from right-hand circularly polarized to left-hand circularly polarized. This device shows potential for integration into various subwavelength terahertz systems.
OPTICAL AND QUANTUM ELECTRONICS
(2023)
Article
Veterinary Sciences
Mohammad Bayzid, Farazi Muhammad Yasir Hasib, Tanjila Hasan, Mohammad Mahmudul Hassan, Mohammad Masuduzzaman, Mohammad Alamgir Hossain, Mohammad Abdul Alim
Summary: This study investigated the prevalence of helminths and protozoal infections in pet birds in Chattogram metropolitan area, Bangladesh. The results showed a high prevalence of helminth and protozoal infections in pet birds, suggesting the need for appropriate prevention and control measures. These findings are important for veterinary practice, aviculturists, pet bird owners, and breeders in Bangladesh.
VETERINARY MEDICINE AND SCIENCE
(2023)
Article
Engineering, Electrical & Electronic
Mohammad A. Alim, Sadia Sultana, Jannatul Naima, Fahmida S. Jui, Sabrina Alam, Ali A. Rezazadeh
Summary: Intermodulation distortion tests were performed using the two-tone technique to investigate the frequency nonlinearity of active devices like nano pHEMT based on gallium arsenide semiconductor material. The results demonstrated a direct connection between intermodulation distortion components and RF transconductance derivatives. It was also found that the third-order intermodulation distortion power is minimized when the second derivative of the transconductance is zero.
INTERNATIONAL JOURNAL OF NUMERICAL MODELLING-ELECTRONIC NETWORKS DEVICES AND FIELDS
(2023)
Article
Energy & Fuels
Md Jaynul Abden, Zhong Tao, Mohammad A. Alim, Zhu Pan, Laurel George, Richard Wuhrer
Summary: This paper evaluates the use of phase change materials (PCM) and thermal insulation in the building envelope of a typical Australian house to promote energy efficiency and cost savings. The results demonstrate that this combination significantly improves the energy ratings and saves costs, depending on the climate zone. This indicates that employing PCM materials and thermal insulation in residential buildings is an effective way to enhance energy efficiency.
JOURNAL OF ENERGY STORAGE
(2022)
Article
Veterinary Sciences
Sabrina Ferdous, Joya Chowdhury, Tanjila Hasan, Pronesh Dutta, Md. Mizanur Rahman, Mohammad Mahmudul Hassan, Md. Rayhan Faruque, Mohammad Abdul Alim
Summary: This study investigated the prevalence of gastrointestinal parasitic infections in wild mammals at Bangabandhu Sheikh Mujib (BSM) safari park and Chattogram (CTG) zoo in Bangladesh. The results showed that wild mammals in both zoos were infected with a total of 17 genera/species of helminths and protozoa. Nematodes were more commonly found compared to other helminths, and herbivores were more susceptible to GI parasites than carnivores and omnivores. Regular monitoring and appropriate therapeutic measures can help reduce the severe consequences of GI parasitic infections in captive wild animals.
VETERINARY MEDICINE AND SCIENCE
(2023)
Article
Engineering, Electrical & Electronic
Mohammad A. Alim, Mayahsa M. Ali
Summary: The paper presents a measurement study of a double channel pHEMT device and investigates the impacts of probe pitch size, position, and applied pressure on the measurements. The study reveals that these impacts are closely related to the stability factor, current gain, and maximum available gain of the microwave device. The RF measurement is frequently affected by these conditions, while the DC measurements remain unaffected or have minor effects.
INTERNATIONAL JOURNAL OF ELECTRONICS
(2023)
Article
Green & Sustainable Science & Technology
Mohammad A. Alim, Sayka Jahan, Ataur Rahman, Mohammad Ataur Rahman, Mark Liebman, Brad Garner, Robert Griffith, Merran Griffith, Zhong Tao
Summary: This study evaluated the technical feasibility of a multilayer detention roof, called a purple roof, in managing urban stormwater. The purple roof outperformed other roof systems by delaying the start times of runoff, reducing runoff volume, and taking longer to discharge stormwater. The study demonstrates that the purple roof technology is effective in slowing the release and reducing the volume of stormwater during different-sized rainfall events.
JOURNAL OF CLEANER PRODUCTION
(2023)
Article
Engineering, Electrical & Electronic
Mohammad Abdul Alim, Anwar Jarndal, Christophe Gaquiere, Giovanni Crupi
Summary: This paper reports on the effects of temperature on the DC and RF transconductance for different HEMT technologies. Various transistor types including single- and double-heterojunction HEMTs, GaAs and GaN materials, virgin and multi-layer pHEMTs, and matched and pseudomorphic HEMTs were analyzed. The temperature effects on the HEMT behavior varied significantly depending on the transistor technology and working conditions. It was observed that the transconductance could either increase or decrease with higher temperature depending on the transistor and bias point. It is worth noting that GaAs transistors demonstrated temperature invariance at a certain bias point, while no such condition was found for GaN-based transistors.
JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
(2023)
Article
Multidisciplinary Sciences
Mohammad Ali, R. Nasrin, M. A. Alim
Summary: The research investigates the effect of slip factor and shape factor on the axisymmetric bullet-shaped object and analyzes the influence of viscous dissipation parameter and location parameter. The study reveals that surface thickness and stretching ratio significantly affect fluid flow and heat transfer processes. Thinner bullet-shaped objects exhibit better cooling conductivity and lower skin friction compared to thicker ones. The findings can be helpful in controlling cooling rate and product quality in industrial sectors.
Article
Chemistry, Multidisciplinary
Sadia Sultana Urmi, Md Abdul Kaium Khan, Tasnim Tareq Ferdous, Davoud Adinehloo, Vasili Perebeinos, Mohammad Abdul Alim
Summary: This research presents the design of a lead-free, all-inorganic and high-performance solar cell based on Cs2TiI6 halide perovskite using rigorous ab initio density-functional theory (DFT) calculations. The theoretical power conversion efficiency (PCE) of the optimized cell, with inorganic TiO2 and CuI as carrier transport layers, is reported to be 21.17%. The study also reveals the enormous potential of Cs2TiI6 as an alternative low-bandgap material for different solar cell applications, and investigates the impact of point defects and defect densities on cell performance.
Article
Materials Science, Multidisciplinary
Md. Shah Alam, Dipta Kumar Das, Omi Akter, Zahid Hasan, Mohammad Abdul Alim
Summary: A study comparing the structural, electronic, and optical properties of LiAuS and NaAuS using density-functional theory calculations was conducted. The results suggest that LiAuS and NaAuS exhibit potential for applications in optoelectronic, photorefractive, and photovoltaic devices.
RESULTS IN PHYSICS
(2023)
Article
Agriculture, Dairy & Animal Science
Md Abul Fazal, Eaftekhar Ahmed Rana, Sazeda Akter, Mohammad Abdul Alim, Himel Barua, Abdul Ahad
Summary: This study investigates the diversity and antimicrobial resistance of Staphylococcus species causing sub-clinical mastitis in dairy herds in Bangladesh. The most predominant species identified were S. chromogenes, S. epidermidis, S. haemolyticus, S. aureus, and S. sciuri. High levels of antimicrobial resistance were observed, and multi-drug resistance isolates were identified in all five species. Several risk factors for SCM caused by different species were also identified, including age, lactation stage, udder condition, use of antimicrobials, and history of previous clinical mastitis.
VETERINARY AND ANIMAL SCIENCE
(2023)
Article
Physics, Condensed Matter
Mohammad Abdul Alim, Mayahsa M. Ali, Christophe Gaquiere
Summary: This research aims to determine whether a GaN HEMT device made on SiC substrate has a memory effect. The intermodulation distortion technique with separation frequency (Delta f) was applied at three different frequency levels, and the findings show a significant effect of the separation frequency (Delta f) on the output power and the nonlinear products within this frequency range.
MICRO AND NANOSTRUCTURES
(2023)
Article
Engineering, Electrical & Electronic
Fahmida Sharmin Jui, Sabrina Alam, Anwar Jarndal, Christophe Gaquiere, Mohammad A. Alim
Summary: This paper presents the modeling of self-heating in GaN-based devices and proposes four different methods to estimate self-heating, thermal resistance, and channel temperature. The focus is on reducing the number of measurements needed to determine self-heating and/or channel temperature for various ambient temperatures. Additionally, a summary of channel temperature for different GaN HEMTs found in-literatures is provided and all findings are compared using a fair difference threshold.
JOURNAL OF COMPUTATIONAL ELECTRONICS
(2023)
Article
Physics, Condensed Matter
Mohammad Abdul Alim, Mayahsa M. Ali, Ali A. Rezazadeh
Summary: This study compares the performance of three transistors and explores their DC, RF, and nonlinearity characteristics to find more linear design solutions for enhancing the overall system performance.
MICRO AND NANOSTRUCTURES
(2022)
