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The composites PVA/CuO, which is made of copper oxide nanoparticles (CuONP) and polyvinyl alcohol (PVA) are created by the solution casting production process. The surface properties of the PVA/CuO composite were then altered using a cold cathode ion source for using these samples in optical devices. The PVA/CuO samples were exposed to argon fluencies of 3 × 1017, 6 × 1017, and 9 × 1017 ions.cm−2. By raising the fluence from 3 × 1017 to 9 × 1017 ions.cm−2, the contact angle is reduced from to 48.43° to 32.52°, while the work of adhesion increased from 119.93 mJ/m to a 132.86 mJ/m. Using the Wemple and Di-Domenico approach, the optical characteristics were computed. The absorption edge is reduced from 2.71 eV for PVA/CuO to 2.56, 1.99, and 1.82 eV, for the samples as exposed to 3 × 1017, 6 × 1017, and 9 × 1017 ions.cm−2 respectively. And the Urbach tail changed from 1.3 eV for the pure film to 1.6, 1.66, and 4.23 eV, and the bandgaps decrease from 3.67 eV to 3.56 eV, 3.48 eV, and 3.32 eV. The obtained results shows the irradiated PVA/CuO films are more applicable for use in optical devices. [ABSTRACT FROM AUTHOR]

As an essential part of integrated circuit, chip manufacturing has increasingly demanding requirements for quality, cost and others. Some technical limitations and the development direction of miniaturisation and high density have led to defects in the manufacturing process, which affect the performance and life of the chip. Therefore, the detection, identification and classification of defects are very important to improve the chip reliability. Based on the orderly and concise literature research, this paper focuses on a comprehensive review of the main research results in the field of non-contact non-destructive testing imaging methods for chip defects. Firstly, various defects that may occur in the chip design and packaging process are introduced. Then the contact detection methods including manual and probe method are clarified, and the principles, properties and development applications of NDT methods are introduced in detail, also the defect identification methods after imaging are briefly introduced. Moreover, the advantages and limitations of NDT technologies are summarised through comparative studies. Finally, the future development trend of non-destructive testing methods is predicted. This work hopes to provide some reference for the non-destructive testing of chips, which is of great significance for the health testing of chips in the electronics manufacturing industry. [ABSTRACT FROM AUTHOR]

The films of P(4ClAni)/CuO, which formed of mixing poly 4-chloroaniline P(4ClAni) by CuO, were fabricated by the casting solution method. The XRD confirmed the successful prepration of the P(4ClAni)/CuO films. Additionally, the effect of CuO on the optical characteristics was determined. The CuO increased the refractive index from 1.09 for P(4ClAni) to 1.11 for P(4ClAni)/CuO-1, and 1.19 for P(4ClAni)/CuO-3, respectively, while the oscillation energy E0 dropped from 4.29 eV for P(4ClAni) to 3.57 eV for P(4ClAni)/CuO-1, 3.12 eV for P(4ClAni)/CuO-2, and 3.06 eV for P(4ClAni)/CuO-3. The charge transfer between P(4ClAni) and CuO increased optical conductivity as the CuO ratios increased. This suggests that modifications in the electronic structure of the composite due to the interactions between P(4ClAni) and CuO. Also, the plasma frequency increased from 0.87 x 1012 s−1 to 2.32 x 1012 s−1. These changes in optical parameters occurred when the polarization of the P(4ClAni)/CuO was altered. The study elucidated the advantages of incorporating CuO nanoparticles as fillers in improving the properties of P(4ClAni) structures. The obtained results indicate the P(4ClAni)/CuO composites were sucessfuly fabricated with novel characteristics that can be applied in flexible optical devices. [ABSTRACT FROM AUTHOR]

Infrared (IR) radiation has been used in food processing applications for its unique high heating efficiency. There is a great need to address the radiation absorption and heating effect during the application of IR in the processing of foods. The radiation wavelength determines the nature of the processing, and it is mainly affected by the type of emitter, operating temperature, and the power supplied. The penetration depth of the IR on food material plays a critical role in the heating level along with the optical characteristics of the IR and food product. The IR radiations cause a significant change in the food components like starch, protein, fats and enzymes. The facility to generate wavelength-specific radiation output can hold the potential of momentously increasing the efficiency of IR heating operations. IR heating is gaining importance in 3D and 4D printing systems, and the application of artificial intelligence in IR processing is being explored. This state-of-art review gives a detailed view of the different emitters of IR and mainly emphasizes the behavior and changes of major food components during IR treatment. The penetration depth of IR, optical characteristics and selective spectral heating based on the target product are discussed. [ABSTRACT FROM AUTHOR]

Nanostructure of copper doped cobalt oxide nanoparticles were synthesized by microwave irradiation assisted method. The prepared nanoparticles were further characterized by using powder X-ray diffraction, Fourier transform infrared spectroscopy, scanning electron microscopy and UV-Vis spectroscopy. The crystalline nature of the nanoparticles is evident from the presence of peaks in the powder X-ray diffraction pattern. The average crystallite size is found to be 20 nm calculated using Debye-Scherer formula. The different functional groups and molecular vibrations are conformed by Fourier transform infrared spectroscopy. The morphological survey of prepared nanoparticles is done by using SEM at 200 nm and 1 µm, respectively. From the micrograph we can confirm the needlelike morphology. The optical properties of nanoparticles were characterized by UV-Vis-NIR spectroscopy. From the tauc plot it is found to be 4.52 eV for indirect transition. [ABSTRACT FROM AUTHOR]

With the expansion and advancement in agricultural and chemical industries, various toxic heavy metals such as lead, cadmium, mercury, zinc, copper, arsenic etc. are continuously released into the environment. Intake of sources contaminated with such toxic metals leads to various health issues. Keeping the serious effects of these toxic metal ions in view, various organic-inorganic nanomaterials based sensors have been exploited for their detection via optical, electrochemical and colorimetric approaches. Since a chemical sensor works on the principle of interaction between the sensing layer and the analytes, a sensor material with large surface area is required to enable the largest possible interaction with the target molecules and hence the sensitivity of the chemical sensor. However, commonly employed materials such as metal oxides and conducting polymers tend to feature relatively low surface areas, and hence resulting in low sensitivity of the sensor. Metal-Organic Frameworks (MOFs) nanostructures are another category of organic-inorganic materials endowed with large surface area, ultra-high and tunable porosity, post-synthesis modification features, readily available active sites, catalytic activity, and chemical/thermal stability. These properties provide high sensitivity to the MOF based sensors due to the adsorption of large number of target analytes. The current review article focuses on MOFs based optical and electrochemical sensors for the detection of heavy metals. [ABSTRACT FROM AUTHOR]

Accurate and up-to-date information on urban built-up areas is significant for managing urban growth and development. Earth Observation (EO) data are valuable sources for meeting this demand. However, the extraction of urban built-up areas from EO data is challenging due to the limitations of EO data sources. To overcome this challenge, this study follows an approach that assesses the performance of optical (Sentinel-2), radar (Sentinel-1) and fused (Sentinel-1 and Sentinel-2) data to extract urban built-up areas using machine learning algorithms including Random Forest (RF), K-Nearest Neighbors (KNN) and KDTree KNN. The results were statistically analyzed by considering the Overall Accuracy (OA) and kappa coefficient. In addition, 15 cm GSD (Ground Sample Distance) aerial photography of the study area was used to validate the results. According to the results, Sentinel-2 produced better representation and accuracy of urban built-up areas than Sentinel-1 and even the fused image. Regarding to machine learning algorithms classification performance, RF performed better in both OA and Kappa coefficient along all datasets. The research findings can have significant implications for various domains, such as urban planning, land use management and open avenues for further comparisons of different EO data sources and machine learning algorithms for built-up areas extraction. [ABSTRACT FROM AUTHOR]

Polymethyl methacrylate/multiwalled carbon nanotubes (PMMA/MWCNTs)/3 wt % (1-x) MnFe2O4/xZnMn2O4 (x = 0, 0.2, 0.5, 0.8) samples were formed using the sol-gel and solvent casting routes. The Rietveld refinement method was applied to explore the different phases in the MnFe2O4/xZnMn2O4 samples. The nano natures of the fillers were investigated using a high resolution transmission electron microscope. The X-ray diffraction technique was used to study the nature of the structure of all polymers. The direct and indirect optical band gap energy (Eg) values for our PMMA/MWCNTs were 5.01 and 4.71 eV, respectively. The direct and indirect Eg values were reduced by doping the polymer with (1-x)MnFe2O4/xZnMn2O4; they were 4.95 and 4.56 eV, respectively, for polymer doped with x = 0.8. The effect of the amount of ZnMn2O4 phase in the nanofillers on the linear and nonlinear optical parameters and also the dielectric constants, electric modulus, and energy density of PMMA/MWCNTs were studied using diffused reflectance and LCR meter techniques. Under an excitation wavelength of 317 nm, the fluorescence spectra of pure PMMA/MWCNTs as well as PMMA/MWCNTs loaded with (1-x)MnFe2O4/xZnMn2O4 samples were inspected. [ABSTRACT FROM AUTHOR]

Polymethyl methacrylate (PMMA)/(1-x)CuCo2O4/xCuS (x = 0, 0.1, 0.25, 0.5) nanocomposites polymers were formed using hydrothermal, solid state and solvent casting procedures. The structure of the filler and polymer nano-composite samples were examined using an X-ray diffraction technique. The impacts of the (1-x)CuCo2O4/xCuS mixture on the diffuse absorption, transmittance, reflectance, extinction coefficient, refractive index, optical dielectric constant, energy loss functions and optical conductivity were investigated. The absorbance of PMMA/(1-x)CuCo2O4/xCuS changed depending on the percentage of CuS in the nanocomposite. The optical band gaps (Eg) for PMMA were 4.52 and 4.46 eV, directly and indirectly, respectively. The sample with x = 0.25 produced the lowest direct/indirect Eg values, 4.34 and 3.79 eV. The fluorescence spectra of the undoped and doped PMMA polymers were explored. Depending on the filler composition in the PMMA/(1-x)CuCo2O4/xCuS samples, the emitted colors could be modulated. The effects of the (1-x)CuCo2O4/xCuS mixture as a function of the dielectric constant, dielectric loss, ac conductivity and electric modulus of the host polymer were examined. [ABSTRACT FROM AUTHOR]

Poly(methyl methacrylate)/polyethylene oxide (PMMA/PEO)/Ni1-xZnxFe2-2xMn2xO4 blends of various composition were formed using coprecipitation and casting techniques. X-ray diffraction (XRD) analysis was performed on the blends and fillers. High-resolution transmission electron microscopy technique revealed that the fillers had a crystallite size of 15–25 nm. The impact of Ni1-xZnxFe2-2xMn2xO4 loading on the light absorbance, transmission, reflectance, refractive index and extinction coefficient and the dielectric constant, energy loss functions, and optical conductivity of PMMA/PEO blend was examined. The absorbance of the PMMA/PEO blend increased irregularly as it was loaded with the nanocomposite samples, and it peaked at x = 0.25. The transmittance reduced to a minimum value (28–58%) as the blend was doped with x=0.25. The PMMA/PEO blended polymer's direct and indirect band gaps were 5.02 and 4.74 eV, respectively. As the blend was loaded with NiFe2O4 alone, they reached their minimum values (direct/indirect: 4.94/4.66 eV). Depending on the amounts of Zn and Mn ions in the NiFe2O4 doped PMMA/PEO blends, the various blends displayed a blue-violet color on their chromaticity diagram. The electrical dielectric constant, electric modulus, ac conductivity and energy density of the different blends depended on the amount of Zn and Mn ions added in the NiFe2O4 matrix. [ABSTRACT FROM AUTHOR]

AbstractUndoped and doped polyvinylpyrrolidone/carboxy-methyl cellulose/zinc sulfide/nickel oxide (PVP/CMC/ZnS/NiO) nanocomposite blends with multi-walled carbon nanotubes (MWCNTs) were prepared using sol-gel and solid-state reactions and casting techniques. Various blends were formed and their composition and morphologies were characterized using X-ray diffraction (XRD) and scanning electron microscope (SEM) techniques. The structures of the nano-fillers were examined using the XRD technique. The influence of the concentrations of MWCNTs on the linear and nonlinear optical parameters of PVP/CMC/ZnS/NiO nanocomposite blends was examined. The optical band gap energies were decreased from (direct, indirect: 5.31, 5.06) eV for undoped blends to 4.38 and 3.34 eV for the blends doped with the highest concentration of MWCNTs (0.15 wt%). The refractive indices of the various blends were calculated based on the obtained optical band gap energies using various models. The effect of MWCNTs concentrations on the dielectric constants, energy density, electric modulus and ac conductivity at room temperature of the PVP/CMC/0.5ZnS-0.5NiO/x wt% MWCNTs samples were explored using an Inductance, L, Capacitance, C, and Resistance, R (LCR) meter bridge. [ABSTRACT FROM AUTHOR]

The production of non-circular thin optical lenses involves initial processes such as circular cutting, grinding, lapping, and polishing. However, shaping the lenses into non-circular forms requires a final cutting process. This study focuses on addressing the distortion of BK7 thin glass parts during side grinding. Two clamping methods were examined to fix the components. The first method, commonly used in the industry, involves bonding the workpiece to a base using resin and subsequent machining, followed by separating the samples from the base by heating the resin. In contrast, this research explores an alternative approach using vacuum clamping. The components' distortion was measured using an interferometer. The results show that the vacuum clamping method produces more uniform surface parameters for the polished components compared to the typical resin bonding method. Additionally, the analysis reveals that surface parameter variations are more pronounced during square side-grinding compared to circular side-grinding. [ABSTRACT FROM AUTHOR]

Polyvinyl chloride (PVC)/polyethylene oxide (PEO)/x wt % polyaniline (PANI) polymer blends were produced using a solvent casting method. X-ray diffraction was used to investigate the formed blends. The effect of adding different amounts of PANI on the light absorbance, transmittance, reflectance, extinction coefficient, refractive index, optical dielectric properties, nonlinear optical parameters and relaxation time characteristics of the PVC/PEO blends were explored. The direct and indirect optical band gap energies of the undoped PVC/PEO were 4.25 and (4.06, 2.76) eV, respectively. The direct and indirect optical band gap energies were reduced to their lowest values (4.02, 3.1) and (3.68, 2.14, 1.12) eV as the amounts of PANI were increased to 0.2 wt %. The effect of alloying between PVC and PEO and adding PANI on the emitted fluorescence spectra under various excitation wavelengths were investigated. All samples displayed varying degrees of blue-violet, blue, or blue-green colors depending on the concentrations of PANI. [ABSTRACT FROM AUTHOR]

A highly selective and sensitive label-free liquid crystal (LC)-based optical DNA biosensor has been reported for the detection of bacterial disease. A sensing platform is constructed using nematic LC (4-cyano-4'−pentyl biphenyl) filled in a confined mesh area of transmission electron microscope (TEM) grid placed within a Polydimethylsiloxane (PDMS) well of a fixed dimension for the detection of bacterial infection caused by Neisseria gonorrhoeae. The optical response associated with LC orientation was investigated by using N. gonorrhoeae nucleotide-specific oligonucleotide probe interacting with both the synthetic complementary ssDNA as well as genomic DNA isolated from N. gonorrhoeae under polarised optical microscope. The grey scale area of the resultant POM images was quantised using Image J software and monitored as a function of DNA concentration. The LC-cell has been able to detect the genomic DNA of N. gonorrhoeae bacteria down to the lowest detectable concentration of 10 pM. The optical response studies of LC-biosensor with genomic DNAs isolated from different bacteria showed high specificity and selectivity exclusively for N. gonorrhoeae pathogen and its potential as a convenient, rapid, and reliable label-free detection for gonorrhoea disease. [ABSTRACT FROM AUTHOR]

The physical properties of near stoichiometric lithium niobate crystals (NSLN) can be improved by adding magnesium. For example, the light damage threshold of NSLN crystals mixed with a small amount of magnesium ions is higher than that of congruent lithium niobate (CLN) crystals mixed with high magnesium [1]. However, the current difficulties also lie in the deviation of SLN crystals from the congruent point, difficulty in growth, size limitation and uneven doping. SLN crystals are still not commercially available, and the size of the crystals is limited to two inches. We use the partial liquid phase method to synthesize polycrystalline materials of co-doped SLN crystals, and successfully solve the problem of uneven doping. The adjustment of process parameters and the use of continuous feeding technology greatly improved the success rate of SLN crystal growth. Then we characterized the grown NSLN crystal on optical and thermal properties. [ABSTRACT FROM AUTHOR]

Polyvinyl alcohol (PVA)/polyvinyl pyrrolidone (PVP) blended polymer loaded with (x) wt. % tetrapropylammonium iodide (TPAI) were fabricated. X-ray diffraction was used to identify the TPAI and crystallinity changes in the blend. TPAI doping's effects on the blends linear and nonlinear optical parameters were examined. The direct and indirect energy gap values of the PVA/PVP blend were reduced from (5, 4.81) eV to (4.77, 4.27) eV and from (4.72, 4.39) eV to (5.11, 4.85) eV as it doped with 25% TPAI in the case of PVA/PVP prepared with distilled water (DW) and dimethylsulfoxide (DMSO), respectively. The value of refractive index at 500 nm was enlarged from 1.32 to 2.3 for the blend doped with TPAI and increased further to 2.67 as it was prepared with DW. A small doping amount of TPAI did not produce a noteworthy alteration in the real part of the dielectric constant (εr) value. By increasing the amount of TPAI (>12.5%), εr increased considerably, with the rate of increase in the blends prepared with DW being higher than that prepared with DMSO. At 500 nm, εr of PVA/PVP increased from 1.8 to 7.11 and 5.34 as it was doped with 31.25%TPAI in the case of the blends prepared with DW and DMSO, respectively. The influences of the solvent, amount of TPAI doping, and excitation wavelength on the fluorescence intensity and emitted colors were also investigated. The maximum DC conductivity (1.89 x10−7 and 1.06 x 10−5 s m−1) was detected at 338 K as the blend was doped with 12.5 wt. % TPAI and prepared with DW and DMSO, respectively. The effects of the amount of TPAI doping and the temperature on the DC conductivity of the various blends were also explored. [ABSTRACT FROM AUTHOR]

In this study, strontium chloride hexahydrate (SrCl2.6 H2O), silver nitrate (AgNO3), and thioacetamide (C2H5NS) were employed as cationic and anionic precursors in the electrochemical deposition technique for the synthesis and characterisation of strontium sulphide doped silver (SrS/Ag) thin films. The spectrum reveals the polycrystalline nature of the materials. The film displayed a significant peak at orientation (111), which corresponds to 2theta values of 26.69° for undoped SrS, and a flawless crystalline peak with a cubic phase indexed at orientations (111), (112), (200), and (211). SrS/Ag of 0.01, 0.02, and 0.03 mol correspond to 2theta values of (26.45, 33.79, 37.60, and 51.77) o respectively. Clove-like material with precipitate is visible in the SrS material's micrograph; the big nano grain on the surface of the substrate exhibits photon absorption but lacks any signs of pinholes. The materials show an increase in thickness from 126.01 to 122.02 nm and an increase in film resistivity from 1.58 × 109 to 1.69 × 109 cm, which further led to a decrease in conductivity from 6.32 × 108 to 5.91 × 108 S/m. The bandgap energy of 1.35 to 2.00 eV was obtained. [ABSTRACT FROM AUTHOR]

Glyphosate (GLY) is a broad-spectrum and non-specific herbicide and it is commonly used worldwide. Since the adverse effects of GLY have been shared, GLY related news are highly attractive for magazines and public. Therefore, there is an increasing number of reports for the development of new detection platforms or methodologies for GLY. In this report, studies for development of GLY-specific (bio)sensors were presented. The total publications per year with the sum of times cited per year and research areas of the reported studies were obtained from Web of Science Core Collection and represented to give a perspective for the scientists in this area. The (bio)sensors developed by different analytical techniques were compared in terms of their advantages and disadvantages. Challenges and progresses for development of hand-held analyser for on-line monitoring of GLY in different samples such as water, soil, foodstuffs or biological fluids were comprehensively discussed. This is the first study in the literature for the purpose of the evaluation of the (bio)sensor designs developed for (bio)monitoring of GLY in combination with different analytical techniques. [ABSTRACT FROM AUTHOR]

This research article describes zinc sulfate-supported cobalt oxide nanoparticles synthesized by microwave irradiation techniques. The prepared nanoparticles were further characterized using powder x-ray diffraction, Fourier transform infrared spectroscopy, scanning electron microscopy, and UV-Vis spectroscopy. The powder x-ray diffraction studies and the result show the good crystalline nature of the sample. The Fourier transform infrared spectrum shows the vibration of metal–oxygen functional groups. The presence of zing doped cobalt oxide nanoparticles was confirmed by UV-Visible spectroscopy. The as prepared zinc sulfate supported Co3O4 nanoparticles was analyzed for their antibacterial activity against Gram-positive (Bacillus subtilis), Gram-negative (Escherichia coli) bacteria, and antifungal activity against (Aspergillus niger). The prepared nanoparticles exhibited a promising biomedical application. [ABSTRACT FROM AUTHOR]

The linear/non-linear optical and dielectric performance of PVA/PVP/graphene composites were enhanced by doping with Cu/ZnO (ZCO) nanoparticles (NPs) for optoelectronic applications. Bare and ZCO polymeric nanocomposites (PNCs) blends were fabricated by the casting method. The structure of the synthesized ZCO NPs and ZCO PNCs was studied by X-ray diffraction (XRD) and Fourier transform infrared (FT-IR) spectroscopy techniques. The optical performance was characterized based on UV-visible-NIR data. The XRD investigations revealed the wurtzite structure of the ZCO NPs with a crystallite size of 17.8 nm. The FT-IR investigations confirmed the integration of ZCO NPs with the host blend's structure. The optical analysis exposed that the direct and indirect band gap of the host blend decreased from 5.20 and 4.94 to 4.36 and 4.29 eV for 10 wt% of ZCO PNCs. The Urbach energy rose from 0.62 to 1.28 eV for 10 wt% of ZCO PNCs. The refractive index grew from 1.29 (bare blend) to 1.82 for 10 wt% of ZCO PNC at hν = 2.0 eV. In addition, a great enhancement in the non-linear optical constants was achieved via ZCO doping. The third-order non-linear susceptibility, χ(3), increased from 1.30 × 10−13 esu (bare) to 9.23 × 10−11 esu for 10 wt% of ZCO PNC at hν = 5.0 eV. We suggest these valuable achievements in the optical behavior of PVA/PVP/graphene blend by ZCO doping nominate it for applications in optical device improvement. [ABSTRACT FROM AUTHOR]

Fe-based spincrossover (SCO) molecular complexes have shown to exhibit spincrossover behavior when subjected to stimuli such as heat, light and pressure. In a previous work, solutions of Fe-based spincrossover (SCO) molecular complexes with increasing ligand length, CnH2n+1NH2 (n = 12, 14, 16) of Fe(L12)2](BF4)2, [Fe(L14)2](BF4)2, and [Fe(L16)2](BF4)2, have shown to produce ultrahigh Seebeck coefficients when subjected to a temperature gradient. In this work, these three compounds are dissolved in dimethyl sulfoxide (DMSO) and subjected to temperature dependent Ultraviolet-visible (UV-vis) spectrometry. This optical characterization method was used to provide a correlation between the ligand length of the SCO complex and the bandgap energy measured. Subsequently, these findings were also triangulated with the effect of the ligand length on ionic conductivity and the Seebeck voltage. This work thus provides a systematic molecular understanding of the optical and electronic characteristics of SCO complexes, which paves the way for molecular design strategies in utilization of SCO for applications such as energy conversion and sensors. [ABSTRACT FROM AUTHOR]

This work, the effect of Fe2O3 and MnO2-doped waste glasses in formula (100−x)waste glasses: x Fe2O3/MnO2 (x = 0.0, 0.2, 0.4, 0.6, 0.8, and 1.0 mol%) were prepared using melt quenching technique and all glass sampled were investigated on physical and optical properties. The results exhibited that the density and refractive index of glass samples increased with Fe2O3/MnO2 content increased. The color of Fe2O3 and MnO2-doped waste glasses displayed yellow and purple, respectively, because of absorbance for Fe2O3 near 440 nm and 1,000 nm which homogeneous distribution of Fe3+ (440 nm: 6A1g(S) → 4T2g(G)) and Fe2+ (1,000 nm: 5T2g(D) → 5Eg(D)) ions in the glass matrices while MnO2 around 486 nm as absorption band is assigned to a single allowed 6A1g(S) → 4T1g(G) transition which arises from the Mn3+ ions (3d4 configuration) in octahedral symmetry. Moreover, the CIE L*a*b* for all glass samples were also investigated. The results indicated that glass production from waste glasses is possible and option for recycling waste glasses to produce artificial gems. [ABSTRACT FROM AUTHOR]

Fused silica glass, in particular, offers a broad range of applications in optics. The present study investigates fused silica samples using non-conventional medium-pressure plasma polishing at optimum machining parameters. The polishing parameters, i.e. gas composition (He: (SF6+O2)) of 90:10, pressure ratio (SF6:O2) of 1:1, total pressure of plasma chamber of 5 mbar, and radio-frequency (RF) power of 80 W have been obtained at optimum parametric conditions. The highest material removal rate of 100.36 × 10−3 mm3/min is achieved at optimized process conditions. Even though the surface finish is slightly degraded from 0.28 µm to 0.30 µm, without any surface contamination as analyzed by the 3D optical profiler and Energy-Dispersive X-ray (EDX). Moreover, EDX analysis reveals the presence of fluorine elements after plasma processing, confirming the plasma's interaction with the substrate. Furthermore, Raman spectroscopy results show a maximum 13% reduction in damaged and strained layers after plasma processing on the machined surface.. [ABSTRACT FROM AUTHOR]

The structural parameters, electronic, optical, and elastic properties of Niobium Carbide (NbC) compound within four different structures: rock-salt (RS), wurtzite (WZ), cesium chloride (CsCl), and Nickel Arsenide (NiAs) are examined using the Full-Potential Linearized-Augmented Plane Wave (FP-LAPW). The exchange–correlation potential (VXC) has been treated by Perdew, Burke, and Ernzerhof's generalized gradient approximation (PBE-GGA) when structural properties, transition pressure, and elastic properties are estimated. For electronic properties, in addition to (PBE-GGA), the modified Becke–Johnson (mBJ-GGA) was used for increased accuracy. Present results show that the RS of NbC is the most stable among the four examined structures with the lowest equilibrium energy. The calculated lattice constants are in good agreement with the former calculations. The elasticity and the formation energy calculations show that NbC is stable within the four studied structures. The electronic band structure calculations of NbC show that it has a metallic nature in the four considered structures. [ABSTRACT FROM AUTHOR]

Polyaniline (PANI)/tin oxide (SnO2) nanocomposites at different loading percentages (6, 9, 12 wt %) of SnO2 were synthesized using co-precipitation and solid state reaction methods for analyzing their structural, optical and electrical behaviors. Properties of the resulting nanocomposites like phase identification, grain size, nature of chemical bonds, elemental analysis, optical and electric behavior were determined using different characterization techniques like x-ray diffraction (XRD), Fourier transform infra-red (FT-IR), Ultraviolet-visible (UV-VIS) absorption spectroscopy and Hall. With the increased wt % of SnO2, the particle size as well as the homogeneity of the nanocomposites increased. Moreover, the band gap also decreased with increased wt of % SnO2, indicating increased conductivity of PANI/SnO2 nanocomposites. Electrical conductivity decreased with addition of SnO2 initially at lower wt % (6) which later increased at higher wt % (9, 12) of SnO2 in PANI matrix. Further study will be based on polyester based nanocomposites to make an overall comparison between pure PANI/SnO2 and PET/PANI/SnO2 at different weight %. [ABSTRACT FROM AUTHOR]

Fruit firmness is of vital importance in various links of the fruit supply chain, such as determining harvest time, choosing packaging and transportation methods, regulating storage conditions and predicting shelf life. Portable devices are useful tools to perform on-site measurements of fruit firmness to guide production, optimize processing procedures, improve handling practices and formulate supply strategies. This paper reviews the recent advances in the design and development of portable devices to evaluate fruit firmness based on sensing mechanical, sonic, vibrational and optical properties of fruits. The principle, structure, composition, application and performance of different portable devices are presented. Since each sensor has its merits and limitations, the integration of multiple microsensors to develop a miniaturized, low-cost and facile-operation device may achieve higher sensing performance in determining fruit firmness. [ABSTRACT FROM AUTHOR]

Polyvinyl alcohol (PVA)/0.25% polyaniline (PANi)/x wt % MWCNTs (x = 0, 0.1, 0.2, 0.5, 0.8, 1) blends were formed. The X-ray diffraction technique was used to investigate the formation of the different blends. The effects of the MWCNTs amounts on the optical parameters and emitted colours of the different blends were investigated. The optical band gaps for PVA/0.25% PANi/x wt % MWCNTs blends are 3.24, 3.13, 3.05, 2.99, 2.84, and 2.95 eV when the MWCNTs amounts in the blends become 0.0, 0.1, 0.2, 0.5, 0.8, and 1 wt %, respectively. The modifications in optical band gaps upon loading PVA/ PANi with MWCNTs indicated that the investigated blends are promising candidates for solar cell and photocatalysis applications. The DC conductivity exhibited a maximum value in the blend with 0.8 wt% MWCNTs. All blends have two activation energies. The influence of MWCNTs amounts on the dielectric constant, AC conductivity, impedance, electric modulus, characteristic frequency, and Nyquist plot of the different blends was examined. [ABSTRACT FROM AUTHOR]

Undoped and doped polyvinyl pyrrolidone/ carboxymethyl cellulose (PVP/CMC: 50/50%) blended polymers with melanin were formed. X-ray diffraction analysis confirmed the amorphous nature of all blends. Scanning electron microscopy results confirmed the smooth and homogeneous surface of the undoped and doped PVP/CMC blend with melanin. The optical parameters and fluorescence spectra of the PVP/CMC blend were investigated as functions of melanin content. The direct optical band gap (Eg) for the used melanin is 2.86 eV. The direct and indirect Eg values for the PVP/CMC blend are 5.1 and (4.9, 3.2) eV, respectively. The direct and indirect Eg values were reduced to (4.5, 3.23) and (2.2, 1.33) eV as the amount of melanin became 3 wt % in the doped blend. The effect of melanin doping on the dielectric constant, dielectric loss, AC conductivity, complex impedance, Nyquist plot of the complex impedance, and electric modulus of the PVP/CMC blend was also studied. [ABSTRACT FROM AUTHOR]

Carboxy-methyl cellulose (CMC)/ polyvinylpyrrolidone (PVP)/(1 − x)NiO–xZnS (x = 0, 0.25, 0.5, 0.75, 1) polymer blends were prepared using casting, sol–gel and solid state reaction methods. X-ray diffraction technique was used to determine the structure and crystallite size of the nanofillers. The crystalline feature of the blends and the nanofillers over the blends matrix were examined using the XRD technique. FTIR was used to confirm the formation of the blends. The effect of the interchangeable proportions of nanoparticles on the optoelectronic properties of the blends was examined using Wemple and DiDomenico model. The transmitted intensity is investigated with lasers at three different wavelengths. A reduction in transmittance makes the studied material promising as attenuating filters at doping levels starting from 75% NiO or less and 25% of ZnS and more even if at relatively high laser powers. [ABSTRACT FROM AUTHOR]

Satellite remote sensing provides an efficient pathway to map inland surface water extent across different spatial and temporal scales. However, how to monitor the surface water distribution and its spatiotemporal variability via combining optical and radar remote sensing datasets still faces substantial challenges. In this study, we propose a Seamless Surface Water Mapping Framework (SSWMF) which synergizes both optical (MODIS, Landsat 8, Sentinel-2) and SAR (Sentinel-1) imageries. The validity of SSWMF was first proved over the middle and lower reaches of the Yangtze River of China with abundant lake resources, showing an overall accuracy of 90.72%, and the results indicate that SSWMF can provide surface water map with higher spatial and temporal continuity compared to the Joint Research Centre Global Surface Water dataset. Multi-source validation showed that the SSWMFderived surface water maps can well capture the temporal fluctuation and spatial heterogeneity of water resources over China, with an overall accuracy of 92.39%. Overall, our results suggest that the proposed water mapping framework is promising and is readily applicable to large-scale water resource management and drought/flood monitoring. [ABSTRACT FROM AUTHOR]

Glacier surface velocity is an important variable for glacier dynamics studies. Estimation of accurate surface velocity from remote sensing is a challenge, especially for glaciers with no in-situ observations. To overcome this challenge, a new method for glacier feature tracking named as Spatially varying WIndow based maximum likelihood Feature Tracking (SWIFT) has been proposed. This method utilizes both optical data (to automatically determine the window size [WS] using the concept of Object Based Image Analysis [OBIA]) and Synthetic Aperture Radar (SAR) data (to perform feature tracking). The proposed method uses a spatially varying WS unlike other existing softwares that cannot provide the flexibility of a spatially varying WS. The proposed method has been tested and validated at three different glaciers (South Glacier [SG], Canada; Chhota Shigri Glacier [CSG], India; and Tasman Glacier [TG], New Zealand) for which field measured data were available. The obtained results for all three glaciers showed consistent improvement in estimated velocity by SWIFT when compared with spatially fixed WS-based estimates from normalized cross correlation-based Correlation Image Analysis Software (CIAS). Considering the data availability, the proposed SWIFT method has been implemented using a variety of SAR and optical satellite data to understand its performance/effectiveness for glacier surface velocity estimation. When validated against field measurements, the results from SWIFT gave an RMSE of 12.8 m/ years, 15.32 m/years and 67.1 m/years for SG, CSG and TG, respectively. Moreover, the RMSE of SWIFT estimates were observed to have an RMSE that was 19–36% lower than the best performing spatially fixed WS. [ABSTRACT FROM AUTHOR]

Land Surface Temperature and Fractional Vegetation Coverage (LST/FVC) space is a classical model in remote sensing of soil moisture (SM). Its most vital issue is the determination of the boundary i.e. dry and wet edges. Visual interpretation and automatic fitting methods are very demanding for the research area. In contrast, theoretical calculation of the boundary has great application potential, where the traditional Priestley-Taylor (PT) equation has been introduced to derive a Sun2016 method. Recently, a new Priestly-Taylor equation was suggested. In order to furtherly improve the optical & thermal remote sensing of SM, we evaluated the new PT equation for boundary determination through deriving a Sun 2021 method. The evaluation was conducted using data from three aircraft experiments for SM observation i.e. SMAPVEX12, SMAPVEX16 in Iowa, and SMAPVEX16 in Manitoba. Simulated data with the Simsphere model was also used. Results demonstrated that the effects of the new PT equation are related to air temperature (Ta). For a certain range of Ta such as from 290 K to 310 K, the Sun 2021 method is close to the Sun2016 method, which implies limited influence of the new PT equation within that range. For Ta out of that range, the Sun 2021 method presented better performance than the Sun2016, which implies stronger suitability of the new PT equation. Sensitivity analysis indicated that the new PT equation increases the sensitivity of calculated wet edge to Ta while decreases its sensitivity to the other input variables. For future extensive application, we also explored convenient ways for determining some essential parameters in the Sun 2021 method. The new PT equation has potential to promote the optical & thermal remote sensing of SM, evapotranspiration, drought, etc. [ABSTRACT FROM AUTHOR]

In this paper, we report on the number of nanorods changing in the structural and optical properties of manganese oxide pyramidal nanostructures with a square cross-section deposited on the glass substrate. The structural and optical properties of the manganese films were investigated. The X-ray diffraction (XRD) analysis showed manganese oxide pyramidal nanostructures with 10, 9, and 8 nanorods that have Mn3O4, Mn3O4, and Mn2O3 phases, respectively. The optical measurement for manganese oxide thin films showed the transmittance and the energy band gap in the ultraviolet and visible regions. The transmittance decreases with increasing the number of nanorods. In addition, the optical band gap increases from 2.64 eV to 2.88 eV with increasing the number of nanorods. [ABSTRACT FROM AUTHOR]

The CdSe thin film was deposited on glass substrate by homemade spray pyrolysis technique at substrate temperature 3000C. Further the film was characterized through X-ray diffraction (XRD), Field emission scanning electron microscopy (FESEM), Energy dispersive X-ray analysis (EDAX), UV-Visible optical spectroscopy and Electrical. The XRD pattern of CdSe film shows polycrystalline hexagonal crystal structure with average crystalline size of the film was 16.3 nm. The SEM micrograph shows the film was uniform, adherent, without pin-hole and crack free. From EDAX analysis conform that the presence of Cd and Se in prepared film with elemental stoichiometry of Cd and Se was 49.30% and 50.70%, respectively. The optical band gap was direct band gap and it was found 1.78 eV. The electrical resistivity of the film at room temperature was 6.9 × 106 Ωcm. [ABSTRACT FROM AUTHOR]

This article represents the gamma irradiation effects on the experimental details of prepared natural dye solar cell (NDSC) components. The optical absorption and physical characteristics of NDSC components were investigated by using different techniques such as Fourier Transform Infrared, Electron Paramagnetic Resonance, Scanning Electron Microscope, and UV−Vis absorption Spectroscopy. The average optical energy gap of the natural fruit dyes was found 2.1 ± 0.3 eV. The transmittance onset of conductive transparent oxide was blue shifted with the increase of gamma dose. Optical energy gap of the electrolyte was calculated to have a value of 2.61 eV. The maximum peaks of incident photon to current efficiency spectrum were found for SnO2 (undoped) film at 515 nm and for SnO2:Sb (doped) film at 550 nm. The short current and open voltage were found to be 0.92 mA and 0.44 V, respectively, for doped film. [ABSTRACT FROM AUTHOR]

The Dy3+ ions doped CaO-ZnO-B2O3 glasses were synthesis by the melt quenching technique with various Dy2O3 concentrations to investigation physical and optical properties. The results showed that the density and the molar volume trend to be increased along with increased Dy3+ concentration. The absorption spectra showed characteristic absorption peaks in the visible and near infrared regions. Judd–Ofelt (JO) intensity parameters have been obtained from the optical absorption spectra. The emission spectra of the glasses are illustrated the highest emission intensity at 574 nm wavelength, which corresponding to Dy3+ transition 4F9/2→6H13/2 level. The decay time value decreased as the concentration of Dy2O3 increased. The CIE 1931 chromaticity investigation showed that Dy3+ doped glasses emitted light with white color. [ABSTRACT FROM AUTHOR]

In the process of magnetorheological polishing of planar optical elements, in order to solve the problem of uneven material removal rate and improve the polishing efficiency of planar optical elements. The finite element simulation was used to optimize the shape of the permanent magnet, and an arc permanent magnet was designed with a radius of curvature of 55 mm. The magnetic flux density of the arc permanent magnet has a Gaussian distribution, which effectively attenuates the effect of linear velocity on polishing. The arc permanent magnet is beneficial to achieve a more uniform material removal and better processing quality. The experiments are conducted on the borosilicate glass using the recent arc permanent magnet and existing planar permanent magnet. The experimental results show that the arc permanent magnets can reduce the average surface roughness value from 286 nm to 16 nm and the standard deviation of surface roughness to 0.92 under the same processing parameters. Therefore, the analysis of the borosilicate glass surface verifies that the designed arc permanent magnets can effectively improve surface accuracy and surface topography. [ABSTRACT FROM AUTHOR]

We report some unclarified physical properties of Ce3XY (X = Al, In and Y = C, N) inverse cubic perovskites by conducting a density functional theory (DFT) study. The elastic, mechanical, magnetic, thermodynamic and optical properties of these compounds were addressed. Obtained elastic data prove the mechanical stability, elastic anisotropy and brittle mechanical character for all investigated compounds. Vickers hardness values follow the Ce3InC > Ce3AlN > Ce3InN > Ce3AlC sequence. All compounds show ionic bonding except the Ce3AlC in which covalent bonding is dominant. Besides, all compounds exhibit ferromagnetic ordering. The calculated total magnetic moments arise between 2.22μB and 2.67μB. Their magnitudes follow Ce3InN > Ce3AlN > Ce3InC > Ce3AlC range. Temperature dependence of heat capacity, entropy, thermal conductivity and Debye temperature of the compounds exhibit identical characteristics of typical solids. Optical property results suggest that these compounds are both good optical absorbers and conductors, in particular for practical applications in the ultraviolet (UV) region. [ABSTRACT FROM AUTHOR]

The Dy3+ ions-doped 25Li2O:20BaO:5Gd2O3:(50-x) SiO2 glasses were synthesized by the melt quenching technique with various Dy2O3 concentrations to investigate physical, optical and luminescence properties. The results showed that the density and the molar volume trend to be increased along with increasing Dy3+ concentration. The absorption spectra showed characteristic absorption peaks in the visible and near infrared regions. The emission spectra of the glasses illustrated the highest emission intensity at 574 nm wavelength, which corresponding to Dy3+ transition of 4F9/2→6H13/2 level. The CIE 1931 chromaticity investigation showed that Dy3+-doped glasses emitted light with white color. J–O analysis indicates that the glass sample performs a good potential for using as white light applications. [ABSTRACT FROM AUTHOR]

Dy3+ doped oxy-fluoride phosphate glass was prepared by melt quenching technique. The glass samples were subjected to FTIR, absorption, and photoluminescence. The absorption spectrum shows several absorption peaks but strong absorption peak observed at wavelength 1280 nm NIR region. Strong yellow emission at 572 nm corresponding to 4F9/2→6H13/2 and blue emission at 482 nm corresponding to 4F9/2→6H15/2 were observed. The analysis of Judd–Ofelt study was applied to establish the intensity parameters and radiative properties of Dy3+ doped oxy-fluoride phosphate glass. The J–O result suggests that the oxy-fluoride phosphate glass has the potential use as an active laser medium. [ABSTRACT FROM AUTHOR]

Plasmonic nanoparticles nanoparticles incorporation increases the photo-physical conversion rate in the semiconductors. Here, we demonstrate the one-pot ZnO/(Ag-Au) nanocomposite for enhanced the visible light photocatalysis. The obtained ZnO nanoparticles are of 10–20 nm size and the deposited metal nanoparticles are of 1–3 nm. The light absorbance spectrum indicated the characteristic band edge absorbance of ZnO (~350 nm) as well as the SPR peaks of Ag (~420 nm) and Au (~520 nm). Enhanced absorption received for the metal nanoparticles deposited ZnO nanocrystals indicate the technological importance of the materials. Emission spectrum of the materials indicated the metal nanoparticles inhibited electron–hole pair recombination process. The photocatalytic methylene blue degradation efficiency of ZnO/(Ag-Au) (87%) nanocomposite is much higher than the ZnO/Ag (65%) and ZnO/Au (57%) nanocomposites. Studies indicated the performance improvement is due to the bimetallic nature over their pristine nature of Ag and Au. [ABSTRACT FROM AUTHOR]

The Eu3+ ions-doped barium gadolinium borate glasses were synthesized by the melt-quenching technique with various Eu2O3 concentrations to investigate the physical, optical, and luminescence properties. The results showed that the density tended to be increased along with increased Eu2O3 concentration, while the molar volume decreased along with increased Eu2O3 concentration. The absorption spectra showed the characteristic absorption peaks in the visible and near-infrared regions. The emission spectra of the glasses were illustrated the highest emission intensity at 613 nm wavelength, which corresponds to the Eu3+ transition, 5D0→7F2. The CIE 1931 chromaticity investigation showed that Eu3+ doped glasses emitted the light with a reddish-orange color. [ABSTRACT FROM AUTHOR]

The Eu3+ ions-doped barium gadolinium borate glasses were synthesized by the melt-quenching technique with various Eu2O3 concentrations to investigate the physical, optical, and luminescence properties. The results showed that the density tended to be increased along with increased Eu2O3 concentration, while the molar volume decreased along with increased Eu2O3 concentration. The absorption spectra showed the characteristic absorption peaks in the visible and near-infrared regions. The emission spectra of the glasses were illustrated the highest emission intensity at 613 nm wavelength, which corresponds to the Eu3+ transition, 5D0→7F2. The CIE 1931 chromaticity investigation showed that Eu3+ doped glasses emitted the light with a reddish-orange color. [ABSTRACT FROM AUTHOR]

Strain effects on magnetic and optical properties of β-SnSe have been investigated by the density functional theory (DFT) approach. Under the compressive strain, the band gap of β-SnSe disappears and becomes metal-like system. By comparison, under the tensile strain, the band gap firstly changes from 2.32 to 1.24 eV, and then it rises to 1.92 eV. We further find that the Sn-p and Se-p states at the bottom of conduction band contribute to the variations of the band structures. Moreover, due to the application of the external strain, the absorption strength in visible light might be enhanced. [ABSTRACT FROM AUTHOR]

The thrust to invent new materials and technology has been ever increasing due to technological challenges in progressive world. Among new materials, nanomaterials possess superior optical, electrical, magnetic, mechanical, and thermal properties, which have made them suitable for a multitude of applications. The present review paper deals with recent advances in properties of nanostructured glasses and composites in terms optical, electrical, mechanical and thermal properties. A brief discussion has been done on fabrication method of nanostructured glasses. The review of optical properties shows that nanostructured glasses show both direct and indirect band gap and this tuning of band gap depends on extent of nano structuring of samples. The electrical properties also show enhancement in electrical conductivity on nano-structuring of glasses compared to their bulk counterparts. The changes in mechanical and thermal properties of nanostructured glasses and composites are attributed to many microstructural features like grain size and shape, their distribution, pores and their distribution, other flaws/defects and their distribution, surface condition, impurity level, second phases/dopants, stress, duration of its application and temperature effect on the samples. Literature reports that nano structuring leads to enhanced phonon boundary scattering which reduces the thermal conductivity. [ABSTRACT FROM AUTHOR]

The ion-exchange from molten salts is a well-established, low-cost technology capable of altering the chemical–physical properties of glass materials. Technologically driven some glass materials containing metal clusters have attracted quite attention both in cluster research and in possible futuristic applications of such nanoclusters for magnetic or optoelectronic purposes. The amalgamation of transparency and hardness at ambient temperature, combined with a suitable mechanical forte and excellent chemical strength, makes this material essential for many applications in different potential technological fields (such as, for instance, the optical fibers which constitute the physical carrier for high-speed communication networks as well as the transducer for a wide range of high-performance sensors, transparency biomarker etc). In this regard, the formation of bimetallic alloys and core–shell nanostructures inside a soda-lime glass was prepared by simple ion-exchange methods and subjected to optical absorption (OA) studies. Further, an attempt has been made for the first time by a novel route for the synthesis of bimetallic nanoclusters, gold in various doses was directly implanted in a plain soda-lime glass as well as in a copper and silver ion-exchanged soda-lime glass using the tandem accelerator anticipating the core–shell or alloys phase between the metal species. Also, the post implanted gold (Au+) metal ions were investigated by Rutherford backscattering spectroscopy (RBS) analysis was performed on the Cu and Ag ion-exchanged samples to confirm the presence of bimetallic clusters formed by ion-exchange during implantation. [ABSTRACT FROM AUTHOR]

PHBV composites with three different hybrid fillers were prepared in which composites with BN/graphene tubes (0.5/1.5) and AlN/graphene tubes (0.5/1.5) exhibit high thermal conductivity (0.4985 W/mK, 0.5215 W/mK), UV/NIR absorption, thermal stability (~267°C), hardness (83D, 82D), storage modulus (2111 MPa, 2322 MPa), low CTE (~47 µm/m °C, ~49 µm/m °C) and roughness (0.105 µm, 0.141 µm) compared to Al2O3/BN composites and virgin PHBV. This enhancement is due to the synergetic effect of hybrid fillers in the PHBV matrix. Overall, prepared PHBV composites may be used for future bio-based USB, SD card and SSD enclosure applications. [ABSTRACT FROM AUTHOR]

We performed density functional theory (DFT) calculations to explore the electronic, optical, elastic and thermoelectric properties of Nb2WNi alloy for the first time by addressing the two different crystal structures (Cu2MnAl and Hg2CuTi) of the alloy. The calculated elastic constants results prove the mechanical stability for both crystal structures of the alloy. As well, Nb2WNi shows ductility for both crystal structures with a dominant metallic character. Nb2WNi alloy can be a good reflector, in particular for practical vacuum UV applications. It has also a high refractive index, especially in the IR region. The optical conductivity results support the use of Nb2WNi alloy for IR solar cell applications. The computed Seebeck coefficient values suggest the potential of Nb2WNi alloy as new thermoelectric material. [ABSTRACT FROM AUTHOR]

Al-matrix composites specifically Al6061-7.5%SiC which holds promising mechanical properties, is a potential candidate in aeronautical industry. Though the reinforcement of SiC in Al-substrate has appreciably enhanced the mechanical characteristics, but it complicates its machining as the composite bears excellent hardness and strength. Moreover, its intended applications require the formation of intricate profiles. Therefore, the processing/machining of such composite is challenging. Wire electric discharge machining (WEDM) is an appreciable choice for Al6061-7.5%SiC machining. However, intrinsic issues of WEDM, i.e., wire vibrations and lag have resulted in a compromised dimensional accuracy of machined part. Furthermore, realization of similar errors' magnitude in both the cutting orientations (axial; EXD and lateral; EYD) is difficult because of the presence of SiC-reinforcement which is a stimulus for wire disturbances. Similarly, this reinforcement influences corner accuracy and makes it's tedious to attain same corner errors at both faces (top; AETOP and bottom; AEBOT). These accuracy issues have not been discussed yet which is primarily done herein using response surface methodology. Statistical, optical, and SEM analyses are performed for detailed understanding of the parametric effects. The minimum error values achieved are 0.01 mm, 0.105 mm, 0.249° and 0.475° in case of EXD, EYD, AETOP and AEBOT respectively. [ABSTRACT FROM AUTHOR]

The purpose of this work is to understand the theoretical aspects related to the compact multi-domain (Optical, Electrical and Thermal) modeling of light-emitting diodes (LEDs). Prior studies have already deliberated extensively on modeling LEDs in multiple domains with diverse levels of intricacies. The need for standardized compact multi-domain models of light-emitting diodes is emphasized. The multi-domain theory explained in this work enables potential end-users to create their own compact multi-domain models of LEDs and study their working in different operating conditions. The end-users can create their own compact multi-domain models of LEDs either from experimental data or from electronic-datasheets. The procedure for developing mathematical models of LEDs in multiple domains is demonstrated in this work. The reason behind current control of LEDs is explained using multi-domain modeling theory. In what way the problem of thermal runaway is handled by driving LEDs with constant current is discussed using the concepts of multi-domain theory. Unlike prior models, it is proposed to model forward voltage as a junction temperature controlled voltage source. Optical power and heating power are represented as junction temperature controlled current sources. The importance of thermal metrics in assessing aging and performance levels is also discussed. This work also recommends minimum parameters required for developing multi-domain compact models of LEDs. [ABSTRACT FROM AUTHOR]