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A polymer valve seat is an essential component of ball valves. However, a gas pipeline valve leakage during the gas or oil transportation process causes major issues. Therefore, the fine finishing of the polymer valve seat is important. This work describes the effect of the magnetorheological finishing (MRF) process on the surface characteristics of the polymer valve seat. To achieve a finely finished polymer valve seat surface, the best process parametric combination of current, workpiece rotational, and tool rotational speed are obtained using the response surface methodology. The optimum process parameters are further used to enhance surface characteristics (including surface roughness, microhardness, and surface morphology) through fine finishing. Using the optimum process conditions, the surface roughness was reduced to 110nm from 570nm in 140min of finishing on a 4878mm² surface area of the polymer valve seat. The circularity of the valve seat surface’s dimensional correctness is investigated further. The current MRF process can fine-finish the polymer valve seat surface consistently, resulting in improved surface characteristics and functional performance.

Lawsonia inermis Linn Leaf extract has been evaluated in alkaline solutions for its influence on electroless Ni–P alloy deposition on mild steel. During electroless plating, the effect of experimental processing conditions on deposition rate is investigated. Bath compositions and operational parameters have been optimized. The findings indicate that increasing the volume of additives from 0.5mL to 5mL improves the inclusion rate of electroless Ni–P alloy coating. In the absence of a complexing agent, additive Lawsone exhibits additional structural features and phases. The deposition rate and the corrosion rate of the Ni–P deposits were estimated, respectively, from the weight loss after a period of time. It is recommended to replace sodium citrate with Lawsone.Lawsone’s effect acting as a complexing agent on Ni–P electroless coating was explored utilizing SEM, EDAX, AFM, FTIR, and XRD, as well as corrosion investigations. Polarization and electrochemical impedance spectroscopy are used to assess the corrosion efficiency.

This study investigates the optimization of wire electrical discharge machining (WEDM) parameters for microchannel machining of aluminum alloy Al 6061 with improved mechanical properties, which is crucial for various industries. This investigation for microchannel fabrication considers four response parameters: material removal rate (MRR), surface roughness (SR), tool wear rate (TWR), and spark gap (SG), alongside four input parameters: pulse on time (Ton), sparking gap voltage (SGV), wire tension (WT), and wire feed rate (WFR). The selected levels for the experiment are, Ton 105, 115, and 125$\mu$s, SGV 10, 25, and 40 volts, WT 6, 8, and 12kgf, and the WFR 2, 4, and 6m/min. By examining Ton, SGV, WT, and WFR, the research identifies optimal conditions using Taguchi-based grey relational analysis (GRA). The findings highlight the importance of parameters such as Ton of 105$\mu$s, SGV of 40 volts, WT of 8kgf, and WFR of 4m/min for machining Al 6061-based microchannels, offering valuable insights for future manufacturing endeavors. This research also incorporates the morphology study of machined Aluminium alloy microchannel.

Abrasive jet machining (AJM) process is commonly used for cutting and drilling of brittle materials in which the phenomenon of material removal can be considered as mechanical erosion by the impingement of high-velocity abrasives. The focus of this research is to compare the performance and economic benefits of recently developed hot abrasive jet machining (hot-AJM) with traditional AJM techniques when machining zirconia ceramic using silicon carbide (SiC) grain particles. The modified AJM employed abrasive air jet (combination of hot abrasive and compressed air) to strike on the work surface for material erosion. Briefly, the cutting performance is investigated by comparing the technological characteristics like material removal rate, machining cost, and taper angle of the developed hole. Abrasive grain size, nozzle pressure, and stand-off distance are considered as the variable factors for machining trials in accordance with the design of experiments. The usage of hot abrasives in AJM improved the material erosion owing to the occurrence of plastic deformation followed by deep chipping on the machined surfaces. From the results, it was observed that the hot-AJM outperformed the normal AJM with regard to improved material removal, reduced dimensional deviation of hole and minimal machining cost. According to the findings of the cost assessment, the machining of zirconia ceramic using hot-AJM was more cost-effective than using normal AJM since it resulted 25% reduction in the total cost of production. The overall machining cost expenditure per unit in hot-AJM was lower (INR 123.12) than expenditure in traditional AJM (INR 153.47). Machining with hot-modified AJM, compared to normal AJM, offers a more techno-economically viable solution for enhancing machinability.

In this paper, we draw a link between cortical intrinsic curvature and the distributions of tangential connection lengths. We suggest that differential rates of surface expansion not only lead to intrinsic curvature of the cortical sheet, but also to differential inter-neuronal spacing. We propose that there follows a consequential change in the profile of neuronal connections: specifically an enhancement of the tendency towards proportionately more short connections. Thus, the degree of cortical intrinsic curvature may have implications for short-range connectivity.

Chemical pretreatments are often used to improve the adhesion of coatings to aluminium. XPS and AFM were used to study the effect of these pretreatments on the surface chemistry and morphology of Al 5005. Four pretreatments were investigated, an acetone degrease, boiling water immersion, and two sulphuric acid etches, FPL and P2. Degreasing had no affect on surface morphology and simply added to the adventitious carbon on the surface. Boiling water immersion produced a chemically stable pseudo-boehmitic surface that was quite porous. The acid etches produced porous pitted surfaces similar to each other but significantly different to the other surfaces. The surface chemistry of the acid etched surfaces was variable and dependant on atmospheric conditions on removal from etch due to the very active surface that the etch produced.

Zinc oxide (ZnO) thin films grown on Si(111) substrates by pulsed laser deposition at O₂ ambient pressure of 1.3 Pa at different deposition temperatures have been studied. ZnO thin films underwent annealing treatment after deposition. The structural and optoelectronic properties of deposited and annealed thin films have been characterized by X-ray diffraction (XRD), atomic force microscopy (AFM), infrared absorption (IR) spectra, four-probe measurements and photoluminescence (PL) spectra. The XRD observation shows that the best crystalline quality of ZnO thin films with hexagonal structure are those grown at a temperature of 400°C and annealed at a temperature of 600°C, respectively. AFM results show that the surface roughness of the ZnO films can be decreased with increasing annealing temperature up to 600°C and then increased by further increasing the annealing temperature. The intense absorption peak sited at 417.54 cm^-1 has been observed by IR spectra for ZnO film grown at 400°C and annealed at 600°C, and the property of absorption is improved by post-annealing. ZnO film grown at 400°C with a resistivity of 12.3 Ω·cm shows the best n-type semiconductor property. The PL spectra show the dominant increase in UV emission by annealing. It is concluded that the best post-annealing temperature is about 600°C.

Zinc oxide (ZnO) thin films were grown on sapphire substrates at different deposition temperatures by pulsed laser deposition (PLD). The structure, composition and optical properties of deposited thin films have been characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), atomic force microscopy (AFM), X-ray photoelectron spectroscopy (XPS), Raman and photoluminescence (PL) spectra. The results show that the ZnO thin films deposited at 500°C have the best crystalline quality with hexagonal structure, surface morphology and stoichiometric composition. The PL spectrum reveals that the sample possesses the strongest ultraviolet (UV) emission at 370 nm and the weakest blue emission at 459 nm under this condition. Raman spectra and weak blue emission of PL spectra show that very few oxygen vacancies exist in the ZnO thin films.

A composite buffer of CeO₂/YSZ/ Y₂O₃ was investigated on the biaxially textured NiW long tape for YBCO coated conductor with magnetron sputtering technique. Every layer's surface morphology was observed by scanning electron microscopy. The seed layer Y₂O₃ film was full coverage of the NiW substrate. The cap layer CeO₂ showed a smooth and crack-free surface and good crystallinity. The roughness of CeO₂ surface was measured by atom force microscopy. The transmission electron microscopy was used to analyze the cross-section of buffer layers and YBCO layer.

SiCO thin-films doped with aluminum (Al) prepared by alternate deposition of SiC and Al thin layers using Ar and O₂ as sputtering gas were deposited on n-Si substrates. The as-deposited thin-films were annealed under 600°C in nitrogen ambient. The thin-films have been characterized by atomic force microscopy, energy dispersive spectrometer, X-ray diffraction, fourier transform infrared spectroscopy, and photoluminescence spectra. The results showed that the introduction of Al promotes the formation of Si—C bonds, but hinders amorphous SiC to further transform to crystalline SiC. The doped Al would react with SiO_x in the thin-films to form more Si particles which strongly affect the optical properties. After Al doped, there presented a seven times of enhancement emission band centered around 412 nm, which is ascribed to nanostructure Si-related defect centers embedded in the SiCO thin-films. The obtained results are expected to have important applications in modern optoelectronic devices.

In this work, laser induced plasma plume intensity and surface morphology of electron-defected silicon have been studied. For this purpose, the silicon (1 1 1) was irradiated with 15 MeV electrons at different doses (2000–10,000 cGy). The electron-defected silicon samples were analyzed by XRD and SEM, showing increase in number of defects (incubation or absorption centers) by increasing electron dose. Afterward, repetitive Nd:YAG laser pulses were applied to electron-defected silicon. The plasma plume due to each laser pulse was photographed by computer controlled image capture system. From the images, the integrated intensity of plasma plume was calculated by image processing software and plotted as a function of number of laser pulses. The plasma plume intensity was found to increase linearly with increasing pulse number for all silicon samples. The integrated intensity of plasma plume also increases for those silicon samples which were irradiated at higher electron doses. The surface morphology of laser-ablated electron-defected samples was examined through SEM showing different phenomena, like thermal, electronic and hydrodynamic sputtering processes along with the formation of cone, craters, re-deposition of material, heat affected zone (HAZ) and debris formation.

Poly(aniline-co-o-bromoaniline) (p(an-co-o-BrAn)) copolymer has been synthesized using chemical oxidation method in the hydrochloric acid medium. Copolymerization of aniline with o-bromoaniline of different compositions, such as 1:1, 1:2, 2:1, 1:3 and 3:1 molar ratios were prepared. The synthesized copolymer is soluble in polar solvents like dimethyl sulphoxide (DMSO), dimethyl formamide (DMF), Tetrahydrofuran (THF) and 1-methyl 2-pyrrolidone (NMP). The copolymer is analyzed by various characterization techniques, such as FTIR, UV–Visible (UV–Vis) spectroscopy, X-ray diffraction (XRD), conductivity, Differential scanning calorimetry (DSC) and scanning electron microscopy (SEM). FTIR spectrum confirms the characteristic peaks of the copolymer containing benzenoid and quinoid ring stretching. UV spectrum reveals the formation of $\pi$–${\pi }^{\ast }$ transition and $n$–${\pi }^{\ast }$ transition between the energy levels. XRD peaks reveal that the copolymer possesses amorphous nature. Morphological study reveals that the agglomerated particles form globular structure and size of the each particle is about 100 nm. The electrical conductivity of the copolymers is found in the range of $10^{-5}\mathrm{\text{S}}{\mathrm{\text{cm}}}^{-1}$. These organic semiconductor materials can be used to fabricate thinner and cheaper environmental friendly optoelectronic devices that will replace the conventional inorganic semiconductors.

Black nickel coatings are widely used in industries due to their shiny black color and other unique properties. However these coatings are normally soft, which limits their applications. In order to increase the mechanical properties of black nickel coatings, sol-enhanced technology has been applied to the plating process. TiO₂ sol-enhanced black nickel nanocomposite coatings were electroplated on nickel-coated brass. A systematic study on the microstructure and properties of the black coatings were conducted. The effects of TiO₂ concentration (TiO₂ sol concentration in 0–20 mL/L) on the surface morphology, nanohardness and wear resistance have been studied. The results indicated that the nanohardness of the sol-enhanced black nickel coating was increased by $\sim$20%. The mechanisms of improvement and surface morphology variation were also discussed.

Gold (Au) coatings are widely used for electrical contacts in devices, decoration and jewelry. However, the relatively low hardness and poor wear resistance of pure Au coatings lead to a short service life and limit their application. Ni is frequently used as an alloying element to enhance the hardness but it lowers the conductivity of Au coatings. In this research, Co was co-deposited as an alloying element with Au to improve its mechanical properties while maintaining conductivity. TiO₂ sol in different concentrations was added to the Au–Co plating bath to further enhance the coating strength. Systematic studies including surface morphology, hardness, wear resistance and electrical conductivity have been carried out. Key results from nanoindentation tests demonstrated that the hardness of Au–Co–TiO₂ composite coating was increased by 30% when compared to a pure Au–Co coating, while the electrical conductivity has been kept at the same level.

In this work, radiation resistance and radiation defects formation of chain semiconductor antiferromagnetic T1FeS₂ monocrystal have been investigated. The sample was irradiated by heavy ions at different doses up to 2.0×10${}^{13}$ ion⋅cm${}^{-2}$. The influence of radiation with heavy xenon ions on the structure of the irradiated layer has been studied and it has shown that, as the radiation dose increases, the number of peaks of the periodicity of the atomic clusters of the nanosize surface decreases exponentially.

GaSe nanoflakes on silicon substrates covered by SiO₂ films are prepared by mechanical exfoliation from the bulk Bridgman-grown GaSe crystals using a scotch tape. The thickness of SiO₂ films on Si substrates providing the highest optical contrast for observation of GaSe flakes is estimated by taking into account the spectral sensitivity of a commercial CMOS camera and broadband visible light illumination. According to our estimations, the optimal SiO₂ thickness is $\sim$126 nm for the visualization of GaSe flakes of 1–3 layers and $\sim$100 nm for the flakes of 40–70 layers. The obtained nanoflakes are investigated by optical and atomic force microscopy and Raman spectroscopy. The observed spectral positions of the Raman peaks are in agreement with the positions of the peaks known for bulk and nanolayered GaSe samples. It is found that the 50 nm thick flakes are stable but are covered by oxide structures with lateral size about 100 nm and height $\sim$5 nm after $\sim$9 months exposure to ambient atmosphere.

In this work, we aimed to evaluate the influence of working pressure on the structure and magnetic properties of the iron film. Iron films were deposited on Si (100) substrates by direct current (DC) magnetron sputtering at different working pressures. The X-ray diffraction (XRD) results indicated that all iron films were polycrystalline BCC structures with the obvious (110) orientation. When the working pressure increased, the (110) peak became weaker and wider, indicating that the crystallinity and the particle size decreased. Particle size gradually decreased, easily seen from the surface morphology. The (100) peak shifted toward the smaller angle with the increase of working pressure, displaying the production of compressive strain. The increase of the working pressure raised the density of defects, which was the origin of the strain. It was the main reason that the Hc dramatically increased. The atomic force microscope (AFM) results exhibited that low working pressure was conducive to obtaining uniform and smooth surface morphology. This is why the iron film at low working pressure can achieve better magnetic properties. The iron film deposited at 0.6 Pa had the largest saturation magnetization (Ms) and squareness ratio (Mr/Ms), the smallest coercivity (Hc), reaching 1573 emu/cm³, 0.86, 102 Oe, respectively.

In this paper, hard silica/epoxy nanocomposite coatings were prepared by a spinning method on the surface of AA6082 aluminum alloy with addition of CdTe quantum dots as the second phase in hard nanocomposite coating with different ratios with respect to main phase (silica nanoparticulates). Wear and electrical conductivity test have been done on the coatings for investigation of the possible enhanced or inverse effects of addition QDs on properties of hard nanocomposite. The effect of coating time, rotating speed and SiO₂/QD ratio have been investigated and it has been shown that by adding QD nanoparticulates, the electrical conductivity of layers is completely controllable without adverse effect on wear resistance. The effects of mentioned parameters on the trend of obtained curves have been discussed.

Thin films of micro bismuth oxide particles were successfully prepared by in situ oxidation of the laser ablated bismuth metal. (111) oriented p-type crystalline silicon substrates were used. The effects of substrate tiled angle on the characteristics of the prepared film were studied. Also, the performance of n-Bi₂O₃/p-Si heterojunction device was investigated. The obtained current–voltage characteristics in dark and under illumination insure the dependence of the fabricated device characteristic on the deposition angle. The I–V characteristics show that all prepared devices are of abrupt type.

This study focuses on effects of number of shots and the distance from the top of anode on Mo–N deposition process on the surfaces of AISI304 samples using a low energy (2.8 kJ) plasma focus device (AECS PF-1) at room temperature. The structural, morphological, elemental composition, surface roughness and micro-hardness properties of treated surfaces were investigated versus the number of shots and the axial distance from the anode. The obtained XRD spectra show that some of the treated surfaces were in crystalline phase with $\gamma$-Mo₂N (FCC) structure (at 3 cm with 10–40 shots and at 5 cm with 30 and 40 shots) and some others had amorphous structure at 5 cm with 10 and 20 shots and at 7 cm with 10–40 shots. SEM images indicate that the thermal effect occurred at 3 cm and the deposition process of Mo–N at 5 cm and 7 cm from the anode with an increase in number of shots. The atomic ratio for nitrogen was 10.62%, 12.88%, and for molybdenum it was 0.23%, 3.36% at 3 cm, respectively. The atomic ratio for nitrogen has achieved 14.95% and 22.17%, however, the atomic ratio for molybdenum was 2.11% and 7.17 % at 5 cm, respectively. The surface roughness and size of grains on the surface of deposited layers were investigated by AFM analysis. Furthermore, the variation in the micro-hardness of the Mo–N thin layers deposited by different number of shots at different distances from the tip of anode was explained, qualitatively, on the basis of morphological characteristics of the thin layers. The decreasing rates of hardness in the case of 10 shots were 146%, 117% and 112%, and at 40 shots were 237%, 149% and 141% with the increasing of distances 3, 5 and 7 cm, respectively.