93 research outputs found

    A 5G beam-steering microstrip array antenna using both-sided microwave integrated circuit technology

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    In this paper a beam steering 2Ă—2 microstrip array antenna is proposed and simulated for the 5G sub-6 GHz frequency band. The array antenna is designed at the resonant frequency of 3.5 GHz. The antenna has four patches excited by two microstrip lines. Microstrip lines on top of teflon substrate of 0.8 mm height and slot line in the ground plane makes a hybrid junction. The design uses both sided microwave integrated circuit (MIC) to feed signal to the patch elements. This designed array antenna has the beam steering capability of maximum -17Âş to +17Âş while keeping the side lobe gain below 10 dB. The simulation results show that the array antenna is designed through good input impedance matching. The antenna has a return loss of -43 dB at center frequency 3.5 GHz. The results also show that the array antenna has a high gain of 12.57 dBi and directivity of 25.11 dB. The maximum gain of this antenna is 24.1 dB at -17Âş and +17Âş. The proposed work is simulated on keysight technologies advanced designed system (ADS)

    Design and characterization of a circularly polarized microstrip-line-fed slot array antenna for S-band applications

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    A 2Ă—2 slot array antenna fed by microstrip line for circular polarization operated in the S band frequency range is designed in this paper. Single cross slot with single port feed as well as dual port feed is taken into consideration for realizing circular polarization and combining these two processes, the slot array is designed with single feed for circular polarization. The antennas are designed on a Teflon glass fiber substrate of thickness 0.8 mm. The slot array dimension is 120Ă—142Ă—1.636 mm3. Smith chart of single cross slot antenna with single feed as well as dual feed has a dip at 2.69 and 2.53 GHz respectively indicate the capability of realizing circular polarization in the S band frequency range. The return loss of the slot array antenna is -58 dB shows good input impedance matching of the antenna. A dip in the smith chart of the slot array shows circular polarization near 2.4 GHz ensuring wireless applications as well. Axial ratio is found to be less than 1 dB in the resonance frequency. The impedance bandwidth percentage of the slot array antenna is 12.24%. The simulation is done by using keysight advanced design system (ADS) software

    Hybrid Rice: Economic Assessment of a Promising Technology for Sustainable Food Grain Production in Bangladesh

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    Hybrid rice, one of the viable and proven technologies has been considered as a new frontier to increase rice production for meeting growing demand for staple food in Bangladesh. Using farm survey data this paper examines comparative profitability of hybrid and inbred rice cultivation and estimates a Stochastic Frontier Function to determine the effect of key variables on farm efficiency. Results show that hybrid rice gives substantially higher yield as well as net return compared to inbred rice which leads to increase and sustainable growth of food grain production. Analysis of Stochastic Frontier model shows hybrid rice farms are technically more efficient than inbred.Hybrid Rice, Technology, Economics, Food Self-sufficiency, Crop Production/Industries, International Development, Research and Development/Tech Change/Emerging Technologies,

    Sonochemical Synthesis, Characterization, and Photocatalytic Performance Evaluation of Au/ZnO Nanocomposite for Methyl Orange Degradation

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    This study examines the impact of gold (Au) incorporation on zinc oxide (ZnO) nanoparticles. Both pure ZnO and Au/ZnO nanocomposite have been synthesized using a unique and environmentally friendly sonochemical approach. The as-synthesized Au/ZnO nanocomposite was characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), and ultraviolet-visible (UV-vis) spectroscopic techniques. Under UV-visible irradiation, the photocatalytic effectiveness of ZnO nanoparticles and Au/ZnO nanocomposites for the degradation of dye was examined. The results demonstrated that the nanocomposite has greater photocatalytic activity than ZnO nanoparticles. This is due to the effective electron transfer from ZnO to Au prolonging the lifetime of photogenerated holes, which play the most important role in the dye degradation process.&nbsp

    Analgesic and anti-inflammatory effects of Crinum asiaticum leaf alcoholic extract in animal models

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    This study investigated the analgesic and anti-inflammatory effects of Crinum asiaticum (Amaryllidaceae) leaf ethanolic extract. Analgesic effect was investigated in acetic acid induced writhing model and formalin induced licking model in swiss albino mice. Anti-inflammatory effect was conducted in carrageenan-induced paw edema model of albino rat. Data were analyzed by one-way analysis of variance (ANOVA) followed by post hoc multiple comparison test. In analgesic study, C. asiaticum extract inhibited 42.34±3.20% of acetic acid induced pain at higher dose of 2.0 g/kg body weight. The effect was statistically significant (p<0.001) compared to the positive control, diclofenac sodium (10 mg/kg). The extract reduced the formalin induced pain 22.60±1.39% in early phase and 27.11±0.87% in late phase at the same dose of 2.0 g/kg and the reductions were significant (p<0.01) compared to the positive control morphine (0.5 mg/kg). In a time-dependent inhibition of carrageenan-induced paw edema model, the extract promoted the inhibitions of paw edema 51.60±2.50% at the 1st h and 40.80±0.52% at the 4th h of administration. These inhibitions were also significant (p<0.01) in comparison to those promoted by diclofenac sodium. No mortality was observed in acute toxicity test. The study concludes that C. asiaticum leaf extract has potential analgesic and anti-inflammatory effects to be recorded as plant-derived complementary medicine.Keywords: Crinum asiaticum, anti-inflammatory, analgesic, Carrageenan, formalinAfrican Journal of Biotechnology Vol. 12(2

    Single feed circularly polarized crescent-cut and extended corner square microstrip antennas for wireless biotelemetry

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    In this paper, the development of two novel circularly polarized microstrip antennas is thoroughly explained. These antennas are fed by coaxial feeding technique. One of the primary objectives of the proposed work is to tune the antennas to work in ISM band. This frequency band refers to the internationally recognized radio frequency bandwidth which is to be used explicitly for Industrial, Scientific, and Medical applications. Therefore, these antennas would be suitable to use in the field of wireless biotelemetry. Two new antenna design techniques have been introduced to produce circular polarization, and details of these schemes are described. The proposed microstrip antennas are designed and simulated on Advanced Design System (ADS) software. The return loss of the proposed crescent-cut antenna is -19.3 dB at the operating frequency. The extended corner antenna has the return loss of -29.3 dB at the tuned frequency. The simulation results are also presented and discussed

    Design and characterization of frequency reconfigurable honey bee antenna for cognitive radio application

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    In this article, a frequency reconfigurable honey-bee compact microstrip monopole antenna is proposed which is fed by a microstrip line (50 Ω) having the capability of providing dual-band as well as triple-band operation in eight distinct modes. By embedding three PIN diodes overs the honey bee arms, the effective current distribution is controlled hence resonant frequency is also changed in eight distinct modes in real-time. This is the reason the proposed antenna is portrayed as a frequency reconfigurable antenna in this paper which is suitable for cognitive radio application. This proposed antenna can be used for various wireless application such as Bluetooth, Wi-Fi, worldwide interoperability for microwave access (WiMAX), wireless local area network (WLAN), C-band, and X-band applications. The proposed antenna possesses a planner geometry of 39×34×0.87 mm3 which is printed on a substrate as flexible FR-4 (lossy) (εr=4.4 and tanδ=0.019). The proposed antenna exhibits voltage standing wave ratio (VSWR)<2 for all 19 resonant frequencies of interest and perceptible radiation pattern over entire frequency bands with a positive gain. CST microwave studio is used to find out all simulated results of antenna parameters

    Logistics and Supply Chain: An Overview of Business Jet Aircraft Manufacturing

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    The paper highlights key points of aircraft manufacturing and supply chain, which includes key supply chain stages of macro processes and logistics of material flow through a network of stages, organization and workstations. Supply chain refers to a series of facilities, with sequence of activities involved in producing and delivering of a product and service. The study was done through personal work experience in an aircraft factory, watching video documentary on National Geography Chanel, literature review of Federal Aviation Administration manuals, books, newspaper articles, aircraft manufacturing websites, and other internet survey. The network of stages starts from ultimate supplier, in the form of raw material, ends up to the final customer, in the form of finished goods. Logistics involve movement of materials, funds, and information between these stages of a supply chain, in a coordinated way. In some large manufacturing facility, such as an aircraft manufacturing factory, multiple stages of supply chain are found within the factory premise itself. Within a specific stage, production lines are found, such that workers and machines are grouped together with a sequence of assigned activities to produce customized, handcrafted, yet standardized outputs. Zooming from supply chain macro level process to micro level manufacturing processes, together with transportation and logistics of material between the stages are highlighted. Keywords: Aircraft Manufacturing, Logistics, Transporation, Supply Chain and Opertions Management

    Photocatalytic decolorization of methyl orange dye using SnO2-TiO2 nanocomposite particles synthesised by Ultrasonic Assisted Co-Precipitation Method

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    The ultrasonic-aided co-precipitation method was used to create SnO2-TiO2 nanocomposite particles. Scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), and UV-vis spectroscopy were used to characterize the nanocomposite particles. XRD patterns revealed the crystalline structure of particles and the average particle size determined by Debye Scherrer’s equation was found to be 11.355, 4.9577, and 4.333 nm for TiO2 nanoparticles, SnO2 nanoparticles, and SnO2-TiO2 nanocomposites, respectively. The Ti, Sn, and O species were confirmed to exist by energy-dispersive X-ray spectroscopy (EDS). The UV absorption peaks at 288, 305, and 350 nm were attributed to SnO2, TiO2-SnO2, and TiO2 respectively. The photocatalytic aspect was investigated in a model organic contaminant (methyl orange). Data obtained by the above-mentioned characterization methods confirmed the superior photocatalytic activity of SnO2-TiO2 nanostructure than SnO2 or TiO2 alone
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