Zinc sulfide (ZnS) nanoparticles have been successfully prepared by sol–gel precipitation method. The successful formation of cubic structure is ensured by XRD analysis and Debye Scherrer’s equation ...is used to determine the crystallite size which was found to be 36 nm for ZnS sample annealed at 200 °C. Surface morphology was studied using HRSEM as well as HRTEM and lattice parameters of the samples were obtained from SAED pattern which was found to have close resemblance to values attained from XRD pattern. Further elemental mapping of ZnS nanoparticles is confirmed by EDX studies. Further Kubelka Munk function was employed to estimate the band gap value which was seen lying within 3.58 to 3.64 eV. Further the antibacterial activity of ZnS is investigated and it is found to be an antibacterial agent of Escherichia coli and staphylococcus aurous, further it can be employed as an antimicrobial agent for prohibiting implant linked infections.
The study investigates the impact of nickel doping on the structural, optical, morphological, and gas sensing properties of zinc oxide (ZnO) thin films. Films were synthesized using a spray pyrolysis ...technique on a glass substrate. Structural and morphological analyses were conducted through X-ray diffraction (XRD) and field emission scanning electron microscopy (FESEM). XRD revealed a hexagonal wurtzite structure, primarily aligned along (101) planes. However, nickel doping prompted a preferred orientation towards (002) plane. Lattice parameters decreased systematically, due to the ionic radii mismatch between dopant and host. FESEM showed a nanoflake morphology. Compositional analysis with energy dispersive X-ray spectroscopy (EDX) confirmed successful doping. Optical analysis using UV–Vis spectroscopy indicated high transmission in undoped ZnO films. However reduced band gap values have been reduced with nickel incorporation. Gas sensing response observed to be significantly improved with Nickel doping in ZnO.
Purpose—rapid urbanization is dangerous to the development of society as it hinders development and makes urban living more difficult. This research aims to develop a system dynamics model for land ...use assessment at transport interactions in Chennai. Design/methodology/approach—the parameters of urbanization can be simulated using a system dynamics model. In this paper, the unchecked urbanization of Southern Chennai is considered as a case study; various parameters, such as population, land use, trip rate, Volume/Capacity (V/C), and Demand/Supply (D/S), are simulated for three different years: 2011, 2021, and 2031. Three scenarios are simulated: the Do-Min scenario (existing trend), partial scenario (some models are implemented), and the desirable scenario (all the proposed models are implemented). Findings—the simulation is performed using the Stella simulation tool. The results show that the proposed desirable model is highly effective in controlling both the population and other parameters. Originality/value—this study has been performed in the Indian city of Chennai, where such studies are rare. This study could help to analyze the traffic situation and make improvements to ease the urbanization issues. This research could also help to analyze the future traffic situation and make improvements to ease urbanization-related issues. Moreover, when the desirable scenario is followed in real-time, it could solve future problems that may arise from traffic congestion in Chennai.
A facile co-precipitation technique is used to fabricate ZnO and AZO (Al-doped ZnO) nanoparticles. It is analyzed and investigated that the effect of Al doping concentration has altered the ...structural and morphological properties of the nanoparticles. Increasing the concentration of doping has reduced the average crystallite size considerably in the range 18–24 nm. With the increased microstrain, we observe that bond length decreases for AZO nanoparticles. FESEM images indicate that morphology varies from the hexagonal crystalline phase of ZnO structure to the spherical shape of AZO samples. The UV–Vis spectroscopic studies showed that Al was incorporated into ZnO lattice as Al
3+
due to the decreasing optical band gap of nanoparticles. The gas sensing responses of ZnO and AZO nanoparticles have been studied at optimum temperature with a low concentration of ammonia gas. The sensing studies revealed that the response of gas mainly relies on the size of the particles.
The spray pyrolysis (SP) technique is an important and powerful method for the preparation of nickel oxide (NiO) and copper-doped nickel oxide thin films. The best films were obtained when the ...substrate temperature, Ts = 450 °C on glass substrates. Copper (Cu) concentrations in the films were varied from 0 to 8%. The effect of Cu concentration on the structural, morphological, spectral, optical, and electrical properties of the thin films were studied by X-ray diffraction (XRD), Scanning electron microscopy (SEM), Fourier transformed infrared spectroscopy (FTIR), UV–vis–NIR spectrophotometer, Hot probe and Hall system. The X-ray diffraction result shows the polycrystalline cubic structure of sprayed films with (200) preferred orientation. The variations of the structural parameters such as lattice parameters and grain sizes were investigated. The SEM image displays the surface morphology of the NiO and Cu:NiO thin films. The FTIR of the as-deposited films were associated with chemical identification. The optical transmittance and absorbance spectra of the films were measured by UV–vis–NIR spectrophotometer. The absorption coefficient and band gaps of the films were calculated using the optical method. All the NiO and Cu:NiO films were p-type. The resistivity of the above films decreases with the increase in copper concentration and so the conductivity of the films depend on the precursor concentration.
•Pure and Cu:NiO films were deposited by Spray pyrolysis technique.•The XRD result shows the polycrystalline nature of pure and Cu:NiO films.•The formation of pure and Cu:NiO were confirmed by FTIR analysis.•Band gap values of pure and Cu:NiO decreases.•All the pure and Cu:NiO films were p-type.
Scanning electron micrograph image of Al doped ZnO with their corresponding gas sensing performance.
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•Synthesis of aluminium doped zinc oxide.•Morphological modulation due to ...doping.•Improved gas sensing performance.
Aluminium (Al)-doped ZnO thin films are synthesised by chemical spray pyrolysis technique and investigated their gas sensing properties. X-ray diffraction analysis of the films revealed the formation of hexagonal-phase (wurtzite) of ZnO with orientation along (002) plane. Interestingly, the lattice parameters of Al-doped ZnO films showed a decreasing trend with Al doping, suggesting incorporation of Al in the crystal lattice of ZnO. A significant change in both the volume of the unit cell and bond length with an increase in Al concentration is observed. The surface morphological analysis suggested the formation of hexagonal-like ZnO, which transform into spherical particles with Al doping. The energy dispersive spectra confirm the existence of Al, Zn and O. The optical absorption analysis showed that the bandgap of ZnO samples decreases from 3.28 eV to 3.21 eV with Al content in ZnO. The ammonia gas sensing properties of ZnO and Al-doped ZnO are studied at 25 ppm concentration of ammonia gas in air at 100 °C temperature, suggesting reasonable gas sensing characteristics.
Nickel oxide (NiO) thin films were prepared by spray pyrolysis technique using a solution of nickel (II) chloride hexahydrate (NiCl
2
.6H
2
O) and distilled water on glass substrates. The substrate ...temperature during deposition was maintained at 450
∘
C. The effect of solution concentration on the structural, morphological, elemental, spectral, optical and electrical properties of the NiO films were studied for different concentrations from 0.1 M to 0.3 M by XRD, SEM, EDX, FTIR, UV-vis-NIR spectrophotometer, Hot probe and Hall effect measurement system. The XRD study reveals that the NiO films are polycrystalline in nature with cubic structure. Also, the crystallite size increases with the increase in solution concentration. According to SEM, the increase in grain size clearly shows the effect of solution concentration. The elemental composition of the film was determined by EDX. FTIR study shows the presence of chemical identification. The optical band gap decreases while the absorption increases with the increase in solution concentration. The electrical study shows that all the NiO films are p-type. However, resistivity, carrier concentration and carrier mobility of the NiO films depend on the solution concentration.
The effects of Zn-doping on structural and gas sensing properties of CuO thin film prepared by a spray pyrolysis technique were systematically studied. The prepared films were characterized through ...X-ray diffraction (XRD), field emission scanning electron microscope (FE-SEM), energy dispersive spectroscopy (EDS), and UV–visible (UV–Vis) spectroscopy. The XRD pattern reveals that synthesized films have polycrystalline, possessing a monoclinic structure with (002) and (111) preferred orientation. The average crystallite size was decreases from 12 to 9 nm with Zn-doping. The FE-SEM images indicate that the prepared thin films were crack-free exhibiting agglomerated spherical structure. The stoichiometric chemical composition of the films was confirmed by EDS analysis, and it revealed the presence of Cu, Zn, and O elements with the desired atomic weight percentage of the films. UV–Vis–NIR spectroscopy showed that films are highly transparent in the NIR region. The optical bandgap of undoped CuO thin films increased with Zn concentration. The response of the CuO to 20 ppm benzene had been enhanced from 48 to 70 by 3% Zn doping. The response and recovery behavior was discussed and the mechanism of the outstanding benzene sensing performance was explained.
This letter presents design and realization of a five-element compact dual-polarized feed for a 4.5 m Cassegrain ground-station reflector antenna. The realized monopulse feed is being used to track ...remote sensing satellites and receive imagery data in X -band frequencies (8-8.5 GHz). The multielement feed consists of one large-aperture corrugated horn acting as main element to extract the communication (sum port) signal and four side-launched circular waveguide elements around the central corrugated horn acting as tracking elements by extracting error signals in both azimuth and elevation. Various design issues of five-element communication/tracking feed assembly are presented along with simulation and measured results. The designed feed assembly satisfies the gain requirements of sum-and-difference pattern and serves as the most simple and compact design.
The aim of this work is the synthesis of ZnO nanostructures and to study the effect of synthesis procedure and morphology on gas-sensing, cytotoxicity and antibacterial activity. The zinc oxide ...nanostructures were synthesized by three different methods: sol–gel (S1), chemical co-precipitation (S2), and microwave heating (S3). X-ray diffraction (XRD), field effective scanning electron microscopy (FESEM), Fourier Transform Infraredand spectra (FTIR) UV–Visible spectroscopy were used to conduct detailed comparative research on the structural, morphological, and optical features of the synthesized materials. The X-ray diffraction studies confirms the hexagonal wurtzite structure of all the samples. The results of the FESEM analysis show that the morphology of prepared powders varies with the synthesis method. The absorption percentage of the synthesized samples ranges between 30 and 62%. The change in percentage is primarily due to the change in optical properties with surface morphology. The static method was used to measure the gas-sensing capacity of the synthesized powders, and it was discovered that the synthesized powders have a strong capability of sensing NH
3
. The biocidal action of the of the compounds in the series has been investigated against few pathogenic bacteria and fungi by disc diffusion method. In addition, the anticancer activity of the compounds was evaluated against various cancer cell lines (A549, HeLa, HepG-2, MCF-7 and HEK 293) and cisplatin was chosen as control. The compound S1 exhibited significant activity against tested four cancer cell lines. The compound S3 showed potent antimicrobial activity, while S1 show significant activity against tested four cancer cell lines. The obtained results were analysed, compared, and discussed using various theories.
