Dye-sensitized solar cells utilize a transparent conductive oxide (TCO) glass which is mainly Fluorine-doped tin oxide (FTO) for the working electrode and counter electrode. The TCO is one of the ...important parts of DSSC. TCO glass becomes the part that determines the price of mass production of DSSC. Low-cost TCOs with high conductivity and high light transmittance are required. In this study, We proposed a simple fabrication of TCO glass by spray deposition method of Tin (II) Chloride (SnCl2) on top of the lime glass substrate. Fabrication was started with 3 mm of Lime glass cleaned with distilled water and ethanol in sonication for 15 minutes and 10 minutes heating at 500°C. The variation of layer thickness was performed by multilayer spray using 2 mg SnCl2 and 5 ml ethanol mixture and then baked for 10 minutes at 500°C. The electrical conductivity, light transmittance, and roughness of the glass at one spray layer were 20 Ω/cm2, 87.1 %, and 0.010 µm respectively, and decrease along with the increase of the number of spray layers. A multimeter, UV-VIS Spectrophotometer, and 3D Measuring Laser Microscope are used to measure these parameters in this study. Compared to the properties of commercially available Fluorine doped Tin Oxide (FTO) glass, this method can be used as an alternative for conductive glass production for Dye-Sensitized Solar cells.
In fused deposition modeling (FDM), the prediction and optimization of surface roughness distribution by varying the process parameters of the printing is required during the process planning stage. ...During this stage, the traditional screening design, such as fractional factorial design, is commonly used to identify the process parameters that have the most considerable effect on process outcomes. The screening design is followed by further experiments, including only essential process parameters to develop prediction models and identify the optimal process parameters. Recently developed custom design approaches such as I-optimal design and definitive screening design (DSD) eliminate the need for follow-up experiments by identifying the critical process parameters and optimum process conditions in a single experimental design. Therefore, the present study is intended to compare the performance of I-optimal design and DSD in terms of prediction and optimization of average surface roughness (Ra) of fused deposition modeling (FDM) printed parts from poly lactic acid (PLA). The following process parameters were considered to reduce the prediction error of Ra models: layer thickness, number of contours, infill density, raster angle, printing speed, extrusion temperature, bed temperature, and built orientation. The results revealed that regression models based on the I-optimal design are saturated and complex, with 38 terms (including eight main effects, twenty three interaction effect, and seven quadratic effects) in the final model. However, the DSD model has 12 model terms (including seven main effects, two interaction effects, and three quadratic effects), making it unsaturated and less complex compared to the I-optimal design. Both models have comparable prediction accuracy based on validation tests. Finally, Ra is optimized based on the desirability function. The results of the present study will add knowledge to the existing literature about the performance of I-optimal and DSD methods in predicting and optimizing responses.
•A mathematical surface roughness prediction model of ground PRMMCs considering different removal mechanisms of matrix and reinforcements was proposed.•The measured modulus and hardness of TiC ...particle with its surrounding steel matrix is reduced from that of TiC itself due to the secondary indentation.•The theoretical predictions are well consistent with experimental data for GT35.
Grinding is usually applied for particle reinforced metal matrix composites (PRMMCs) to achieve high ground surface quality. However, the surface quality especially surface roughness is difficult to predict theoretically due to different mechanical properties of two or more phases inside the PRMMCs. In this study, an analytical model of the surface roughness of ground PRMMCs is developed based on an undeformed chip thickness model with Rayleigh probability distribution by considering the different removal mechanism of metal matrix and reinforcement particles in grinding. GT35, a typical kind of steel based metal matrix composite reinforced with TiC particles is investigated as an example. Nanoindentation experiments are employed for the investigation of nanomechanical properties and cracking behavior of GT35 and the nanoindentation results are integrated in the model. Single factor surface grinding experiments of GT35 are also carried out to understand the material removal mechanism of GT35 and validate this novel surface roughness prediction model. The predicted surface roughness from this model shows good agreement with the experimental results.
•The effects of the vertical and horizontal scales of surface roughness on the scattering properties of atmospheric particles are systematically studied.•The vertical scales of surface roughness with ...an average perturbation size parameter of 0.1 or greater are needed to affect particle scattering properties.•The horizontal scales of rough surfaces with size parameters less than ∼3 do not influence the optical scattering properties too much.•Rough surface models of different kinds can be unified by constraining only their vertical and horizontal scales.
A systematic modeling study is conducted to investigate the effects of vertical and horizontal scales of small-scale surface roughness on the scattering properties of atmospheric particles, e.g., ice crystals and dust particles. Regular Chebyshev rough surfaces and randomly generated irregular surfaces, both of which can provide well-defined vertical and horizontal scales, are developed as rough surface models. The vertical scale is defined as the maximum perturbation in the Chebyshev surface or as the average perturbation for the irregular surface, and the horizontal scale is defined by the length period of the rough structure in the surface horizontal direction. A pseudo-spectral time domain method is used to calculate the single-scattering properties of randomly oriented cubes with surface perturbations of different vertical and horizontal scales. The vertical scale of surface roughness plays a fundamental role in determining the scattering properties of nonspherical particles. The phase matrix elements of roughened particles with average perturbation amplitudes of 0.1 (in units of size parameter) or greater noticeably differ from those of smooth particles, whereas the influence of rough surfaces with smaller mean vertical scales can almost be ignored. Meanwhile, the horizontal scales of the rough surface with length period size parameters less than 3~5 (for different refractive indices) do not influence the optical scattering properties of the roughened particles. Furthermore, with irregular surface perturbations that are randomly determined to follow different distributions but have the same average vertical scale (i.e., amplitude), the roughened cubes yield the same phase matrix elements as those with regular Chebyshev surfaces. This indicates that rough surface models of different kinds may be unified by constraining only their vertical and horizontal scales.
The new generation antenna has high-quality processing requirements on the resin-rich layer of the reflecting surface. A polishing experiment on the resin-rich layer was carried out to study the ...parameters affecting the surface roughness of the layer, namely polishing time, abrasive particle size, abrasive particle mass fraction, loading pressure and polishing speed. The results show that under the current conditions, the surface roughness first decreases and then tends to be stable with the increase of polishing time. It increases with the increase of the abrasive particle size or the loading pressure, and first decreases and then increases with the increase of the abrasive particle mass fraction or the polishing speed. On this basis, an optimized process parameter combination is formed, which includes an abrasive size of 25 nm, an abrasive particle mass fraction of 20%, a loading pressure of 14.1 kPa, a polishing speed of 50 r/min, a polishing time of 1.0 hours, and a slurry flow rate of 10 mL/min. A high-q
The complex structure of turning aggravates obtaining the desired results in terms of tool wear and surface roughness. The existence of high temperature and pressure make difficult to reach and ...observe the cutting area. In-direct tool condition, monitoring systems provide tracking the condition of cutting tool via several released or converted energy types, namely, heat, acoustic emission, vibration, cutting forces and motor current. Tool wear inevitably progresses during metal cutting and has a relationship with these energy types. Indirect tool condition monitoring systems use sensors situated around the cutting area to state the wear condition of the cutting tool without intervention to cutting zone. In this study, sensors mostly used in indirect tool condition monitoring systems and their correlations between tool wear are reviewed to summarize the literature survey in this field for the last two decades. The reviews about tool condition monitoring systems in turning are very limited, and relationship between measured variables such as tool wear and vibration require a detailed analysis. In this work, the main aim is to discuss the effect of sensorial data on tool wear by considering previous published papers. As a computer aided electronic and mechanical support system, tool condition monitoring paves the way for machining industry and the future and development of Industry 4.0.
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•Calcination reduced diameters of electrospun TiO2 nanofibers.•Formation of crystalline anatase TiO2 in nanofibers after calcination at 500 °C.•Higher applied voltage prepared ...TiO2/PVP nanofibers with higher diameters.•Higher applied voltage led to TiO2 nanofibers with lower diameters.•Calcination reduced Sq value of thin films of electrospun TiO2 nanofibers.•Thickness of thin film of TiO2 nanofibers reduced 50% after calcination at 500 °C.
In this work, thin films of TiO2/PVP nanofibers were prepared on glass substrates by combination of sol-gel and electrospinning methods. After calcination at 500 °C for 3 h, they were transformed to thin films of TiO2 nanofibers, in situ. Thermogravimetric analysis of the as-spun TiO2/PVP nanofibers showed a sharp peak at 488 °C that proved the change of amorphous TiO2 to crystalline anatase TiO2 in these nanofibers. In addition, Raman, XRD and HRTEM analyses established the formation of anatase phase in TiO2 nanofibers. The SEM micrographs disclosed the final three-dimensional network of the thin films of TiO2 nanofibers after calcination process, as well as the changes in their morphology. These changes were mainly occurred through reduction of diameters of the electrospun nanofibers from 178 ± 100 nm to 60 ± 18 nm and 228 ± 94 nm to 56 ± 16 nm electrospun at applied voltages of 12 and 15 kV, respectively. AFM images were used for surface analyses of the samples. Remarkably, calcination process resulted in the reduction of root-mean squares (RMS) surface roughness (Sq) of the thin films of the TiO2 nanofibers. For nanofibers electrospun at 12 kV, Sq reduced from 204 nm to 113 nm and for sample electrospun at 15 kV, it decreased from 154 nm to 52 nm after calcination. The other surface roughness parameters, i.e., skewness (Ssk), kurtosis (Sku), texture aspect ratio (Str), core fluid retention index (Sci), and valley fluid retention index (Svi) showed enhancement which have been discussed in details, accordingly.
Focus on lightweight materials like aluminium, titanium etc. are growing as a reason of its eminent strength, resistance to corrosion, and less weight. Employing additive manufacturing (AM) process ...to fashion complex parts is increasing day-to-day. AlSi10Mg handled by laser-based powder bed fusion (LPBF) is an emerging material because of its high performance and reduced coefficient of thermal expansion due to the presence of silicon. However, AM process shows several advantages, poor surface quality is a mere disadvantage, which requires a post processing. The machining of LPBF parts for improving their quality is a difficult task as a reason of component orientation and layer thickness (LT). Recently, a new trend has developed, AM process combined with subtraction of materials to get good surface characteristics. This holistic investigation addresses problems like surface morphology, tool wear and temperature with varied cooling techniques (Dry, Flood and MQL) while machining AM-AlSi10mg work material. Generation of heat at the cutting region is responsible for surface deterioration and frequent change of tools. Compared to dry and flood condition, the MQL improved the surface trait by 45–63% and 23–43%; flank wear by 45–29% and 18–31%, respectively. SEM images show flakes in all the cutting environments. It has also been established that MQL method increases microhardness on the machined face by removing the heat in the cutting region.
In this paper, through a series of grinding experiments with different machining parameters on the surface of the workpiece, the surface roughness under different machining parameters are obtained ...The surface roughness prediction model is constructed by the response surface method. The effects of feed rate, amplitude, and spindle speed on the surface roughness are analyzed. The results show that the surface quality of ultrasonic-assisted grinding is better than that of conventional grinding. Amplitude has the most prominent effect on the improvement of surface quality, followed by the spindle speed. The feed rate has little effect on the surface roughness. The model can predict 93.71% of the experimental results and the prediction error of the model is lower than 5%.
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