Sensors International最新文献

This paper presents a beamforming D-band phased array in proximity coupled fed microstrip antennas design at 132–160 ​GHz frequency working range. The first beamforming phased array microstrip antenna simulation with the CST MWS software was also simulated with Ansys HFSS for equalization. The simulation results obtained from a couple of simulators were in good agreement, supporting the suggested design. Furthermore, it has been demonstrated that the proposed antennas supply high peak gain, high peak total efficiency, and decent steering angles of 26.05 ​dB and 88.33%, ‒13.5° to 13.7°, respectively. Moreover, an innovatory error analysis simulation has been done to approximate the proposed antenna's BW and the gain because of the anticipated manufacturing etching accuracy deviation, the dielectric constant of the microstrip laminates, and the loss tangent of the microstrip laminates indicate the possible high-frequency losses, which are frequency-dependent. That makes them suitable as a base for a D-band line-of-sight (LoS) medium-distance base-station beamforming beyond 5G (B5G) cellular communication and for Terahertz (THz) imaging sensor, nondestructive testing (NDT) sensor, biological imaging sensor, and material characterization sensor.

Zinc oxide (ZnO) is a one-of-a-kind material with semiconducting, piezoelectric, & pyroelectric properties. Before the arrival of the nanotechnology field, zinc oxide was used in bulk, but later it was also employed as a nanosized material for its intended purposes. ZnO in nano-scale materials is currently among the most significant semiconductor oxides. Nanotechnology is a broad field of study that has emerged as a cutting-edge & advanced manufacturing technology worldwide. Nanomaterials have diameters less than 100 ​nm. So, many materials are used in various applications; one of the common materials, i.e., Zinc oxides, are unique in their physiochemical properties, so they can be called multi-functional nanomaterial. Zinc oxide has been used as a nanomaterial based on its different morphologies such as–nano-particles/rods/wires/flakes/flower/sheets & etc. Zinc oxide plays an essential role in all most every field, from non-electric to the electronic field, diagnosis to therapeutics, textiles to agriculture. The first section of this evaluation includes an introduction, a brief history, properties, and benefits. The following section of this review describes the various fabrication methods of ZnO - indirect, direct, hydrothermal, sol-gel, chemical precipitation, green synthesis methods. Finally, this article presented prospective implementations of ZnO in many fields of industry. This review provides valuable information to specialize in ZnO, covering the research undertaken in the early 1990s until the new use of zinc oxides in 2022.

Graphene is the primitive two-dimensional crystal ever discovered by humankind. It's composed of just one graphite sheet, yet its unique features are redefining material science. However, practical mass-production technologies for defect-free monolayer graphene are currently lacking. Because of their planar shape, lightweight, high aspect ratio, electrical conductivity, inexpensiveness, and mechanical durability, graphene nanoparticles are appealing. Graphene and its associated derivatives, such as graphene, graphene oxide, reduced graphene oxide, and graphene materials have been generally regarded as viable possibilities for industrial, environmental, and biomedical applications because of the rapid development of synthesis and functionalization procedures. Currently, the utilization of graphene nanomaterials leads to great innovation in the field of nano-biotechnology due to its nano-size, unique morphology, large surface area, and strong properties. Due to such unusual properties of graphene and its nanomaterials comes in a wide range of shapes which are discussed in this review along with their synthesis method and also cover a wide portion of the applications. The review aims to summarize the outcomes of current studies of graphene and its nanomaterial and also disclose the most promising applications of graphene nanomaterial which revolutionizing the material science.

Metronidazole (MTZ) is a widely used antibiotic to treat infections caused by anaerobic bacteria, protozoa, and bacteroids such as trichromonosis and vaginosis. In this study, we present a simple strategy for constructing an electroanalysis platform for metronidazole in real samples. We prepared a modified carbon paste with α-Fe₂O₃ magnetic core nanoparticles to construct an α-Fe₂O₃@CPE electrochemical sensor. The surface morphology and composition of the sensor were evaluated using several methods, such as X-ray diffraction and scanning electron microscope. The average size of the α-Fe₂O₃ magnetic core nanoparticles was around 34.30 ​nm. Cyclic voltammetry, electrochemical impedance spectroscopy and chrono-coulometry were performed for the understanding of the electron transfer behavior on the electrocatalytic surface of α-Fe₂O₃@CPE and the unmodified electrode CPE. The resulting sensor demonstrates a very good shift of the Metronidazole reduction peak to a more positive potential (−0.57v vs Ag/AgCl) compared to the unmodified CPE electrode (−0.71v .vs Ag/AgCl). The Metronidazole peak reduction current Ipc varies linearly with metronidazole concentration in the range of 10^-4 ​M to 0.8x10^-6 ​M with a limit of detection and limit of quantification of 2.852x10^-7 ​M and 9.509x10^-7 ​M respectively. Exceeding the detection limits of several existing analytical methods. The proposed procedure has been successfully demonstrated on pharmaceutical tablets and real tap water and urine samples.

Monodisperse pure and nickel-doped iron oxide Ni_xFe_3-xO₄ (x ​= ​0.00, 0.02, 0.04, and 0.06) nanospheres were synthesized by hydrothermal method. The synthetic method was featured by using a structure directing agent, namely, anhydrous sodium acetate and ferric ions source, iron (III) chloride in an ethylene glycol solution without any kind of surfactant or template involved. The molar ratio of salts to anhydrous sodium acetate was optimized to 1:4 to get monodispersed and uniform spherical nanostructures. The sensing response of nickel doped iron oxide to different gases such as acetone, ammonia, sulphur dioxide, hydrogen sulphide, ethanol and methanol are accomplished at room temperature with the gas concentration of 5 ​ppm and was found selective towards acetone with response 29.9%. The response of Ni_xFe_3-xO₄ (x ​= ​0.06) nanospheres were found to be 29.9%, 46%, 66%, 106%, and 174% towards 5, 10, 15, 20 and 25 ​ppm acetone concentration respectively. The response and recovery time at 5 ​ppm acetone concentration was found to be 94 ​s and 68 ​s respectively. Based on the reproducibility and stability test, it was observed that the fabricated sensor based on nickel doped iron oxide is highly reliable. The energy band diagram of the sensing mechanism of Ni_xFe_3-xO₄ (x ​= ​0.06) nanospheres upon exposure to air and acetone atmosphere are presented.

Samarium titanate (Sm₂Ti₂O₇) is a perovskite layered structure (PLS) material with high Curie temperature (T_C ​≥ ​1247 ​°C). Sm₂Ti₂O₇ (STO) powders were synthesized by solid state reaction method by calcining the constituent powders at 1100 ​°C for 2 ​h. The average crystallite size of calcined STO powder was measured to be 61 ​nm. Circular discs of STO samples were sintered between the temperature range 1250–1450 ​°C with a soaking time of 2 ​h and sintered density was highest (>96.35% Th.) for the samples sintered at 1450 ​°C. The direct current electrical resistivity linearly decreased from 10¹³ to 10⁶ ​Ω.cm during its increase in temperature from 100 to 900 ​°C. The activation energy of the STO samples were 0.38 ​± ​0.01 ​eV (Ea₁) and 1.77 ​± ​0.01 ​eV (Ea₂) at temperature ranges 100 to 400 ​°C and 500 to 900 ​°C, respectively. Hence, samarium titanate is a promising sensor material for high-temperature applications.

Our modern world is completely driven by our ability to communicate all over the world with great precision, accuracy, and the least amount of time possible. Communication systems are used vastly in our worlds such as radar, aerospace, naval/maritime communication, underwater communication, mobile communication, or even in outer space such as satellite communication or space missions. Different communication system needs different types of modulation techniques. Design and implementation of reconfigurable modulators on cyclone-II FPGA (Field-programmable gate array) are proposed in this paper, wherein the type of modulations and demodulation can be dynamically reconfigured on the fly based on the requirement at any particular instance. The demodulator is intelligent enough to demodulate any modulated signal. FPGA or Field Programmable Gate Array is a computing device that can be programmed like CPU (Central Processing Unit) but fasted than CPU in parallel processing and DSP (Digital Signal Processing) related tasks. Consisting method of FPGA-based modulation does not support multiple modulation techniques at the same time and is not fast as they used Simulink-based simulation. This study has proposed FPGA based alternative to that, which can embody all the modulation techniques at once, making it way more versatile, cost-effective, and easy to use and test. The process begins with designing an algorithm. Then this algorithm has to be simulated. The algorithm is designed for both modulation and demodulation. In the modulation part, it is just simple logic to create different phrases and different frequencies of sinusoidal waves. But in demodulation, based on the frequency it can detect ASK (Amplitude Shift Keying) or FSK (Frequency Shift Keying) signal all by itself. Depending on the period of the signal, the algorithm can decide whether it is an ASK or FSK signal. After deciding it is an ASK of FSK signal, it starts to demodulate the signal. The outcome is, this FPGA-based modulator and demodulator are cheap, easy to configure, and can demodulate any type of demodulated signal. As it is reconfigurable, it's easy to deploy in any situation.

Fuzzy theory is the optimal method for predicting the state of an entity in dynamic situations. The fuzzy theory incorporates different linguistic variables and membership functions for estimating the state of the entity through the enforcement of the fuzzy inference engine. In MANETs, the prediction of path stability is determined to be potentially identified by deriving the benefits of fuzzy theory since it is a suitable candidate for identifying the state of the path in dynamic conditions. Fuzzy theory is more significant in exploring different possible states under path stability determination than the Gray and Markov chains. This paper presents the Adaptive Fuzzy Logic Inspired Path Longevity Factor-Based Forecasting Model(AFLIPLFFM) for accurate prediction of path stability to improve the throughput and Packet delivery ratio in the network. The AFLIPLFFM scheme first computes the $\text{IPR}$ of mobile nodes. It then uses it as input to the fuzzy inference engine for computing the output as path stability based on the formulation of IF-THEN-based rules for triangular membership function. It also inherited the merits of the triangular membership function and Mamdani Fuzzy Inference Engine for accomplishing the objective of path stability prediction.

In this study, potentiodynamically fabricated poly (diaquabis(1,10-phenanthroline) copper(II)chloride) modified glassy carbon electrode (poly(A₂P₂CuC)/GCE) is reported for detection of aspirin in tablet samples. EIS and CV analysis of Fe(CN)₆]^3-/4- at the modified electrode revealed surface modification by an electroactive polymer material that improved electrode effective surface area and charge transfer resistance. An oxidative peak without a reductive peak in the reverse scan direction for aspirin at poly(A₂P₂CuC/GCE augmented by peak potential shift with scan rate showed the irreversibility of the electrochemical oxidation of ASA at the electrode. A better R² (0.9983) for dependence of peak current on square root of scan rate than R² (0.9612) on scan rate indicated that oxidation of aspirin at poly(A₂P₂CuC)/GCE was predominantly diffusion mass transport controlled. Under optimized PBS pH (5.5), and square wave parameters, oxidative peak current response of poly(A₂P₂CuC)/GCE showed linear dependence on the concentration of aspirin in the range 1–200 ​μM with associated %RSD under 3.7% (n ​= ​3), limit of detection 0.039 ​μM, and limit of quantification and 0.13 ​μM. Spike recovery result in the range 96.5–100.5% with %RSD under 1.9% (n ​= ​3), and interference recovery in the range 97.2–103.4% in the presence of 50–200% of uric acid, ascorbic acid, and glucose as potential interferents validated the applicability of the developed method for determination of aspirin content in tablet samples. Detection of aspirin in the studied tablet samples in an amount 99.4–101.5% of their nominal values with %RSD under 2.6% using the present method showed the applicability of the method to control the aspirin content in tablet samples. The present method showed better performance over the previously reported methods for determination of aspirin in tablet samples making it an excellent candidate.

The present work investigates the electrochemical studies of atorvastatin (ATRV) by establishing graphene (GR) and cationic surfactant cetyltrimethylammonium bromide (CTAB) based electrochemical sensor (GR-CTAB/CPE). The morphological study of a modifier was executed utilizing the electronic scanning microscopy (SEM) technique. GR-CTAB/CPE was identified as a supersensitive electrode for the identification of ATRV, as the electrochemical sensor exhibited enhanced electrocatalytic property and increased peak current in pH 4.2 of phosphate buffer solution employing voltammetric approaches like cyclic voltammetry (CV) and differential pulse voltammetry (DPV). The impact of pre-concentration time, supporting electrolyte (pH), scan rate, and concentration was examined. The number of protons and electrons involved in the electro-oxidative mechanism of ATRV was depicted. The ATRV at the developed sensor has a limit of detection of 2.46 ​× ​10⁻⁹ ​M. The proposed method was proven effective in determining ATRV concentration in clinical and biological samples. The data obtained from the recovery studies suggests that the GR-CTAB/CPE was selective and highly sensible in identifying ATRV.