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This research “the analysis of different welding speeds, the micro structure on the welded joints of silicon steel pipe” has been carried out on precise and accurate measurements of parameters. The effects of different laser powers on the weld material have critically been studied and analyzed. Welding speeds have great effect on the micro-structure and morphology of the weld material. The determination of the basic components of the active agent is the key of the preparation. The active materials selected in this experiment are the commonly used oxides (SiO2, TiO2, and Cr2O3) and fluoride (NaF) reagents. However, the comprehensive experiment contains a large number of the level of combination; the workload is huge, due to the experimental site, experimental materials, funding, and time constraints lead to low efficiency. In the laser welding of silicon steel sheet, coating active agent can increase the penetration depth and affect the weld formation, and the influence of active agent NaF and SiO2 on weld penetration of silicon steel sheet is significant. The formula G is the most effective in increasing the penetration depth, including 25% SiO2, 25% TiO2, 12.5%Cr2O3 and 37.5% NaF.

The influence of erbium on physical and optical properties of calcium sulfate ultra-phosphate glass was investigated using conventional melt quench process. Selected samples of composition 20CaSO4 (80 – x) P2O5– xEr2O3 with 0.1 [Formula: see text]x [Formula: see text] 0.9 mol.% were prepared and assessed. X-ray diffraction (XRD) techniques were used to confirm the amorphous nature of the said samples. The structural units of phosphate-based glass were assessed from Raman spectra as ultra-(Q3), meta-(Q2), pyro-(Q1) and orthophosphate (Q0) units. Depolymerization process of the glasses was testified for higher calcium oxide content and UV-visible for optical measurement. Thermal analysis have been investigated by means of thermogravimetric analysis. The results show the decomposition of materials in the temperature range of 25[Formula: see text]C–1000[Formula: see text]C. Er[Formula: see text] absorption spectra were measured in the range of 400–1800[Formula: see text]nm. PL measurement was carried out in order to obtain the excitation and emission spectra of the samples. The emission spectra excited at 779[Formula: see text]nm comprises of 518[Formula: see text]nm, 550[Formula: see text]nm and 649[Formula: see text]nm of transition 4F[Formula: see text], 4S[Formula: see text] and 2H[Formula: see text] excited states to 4I[Formula: see text] ground state. In physical properties, the density calculated using Archimedes method is inversely proportional to molar volume with increase in Er[Formula: see text] ions. Optical bandgap (E[Formula: see text]) were determined using Tauc’s plots for direct transitions where E[Formula: see text] (direct) decreases with increase in erbium content. The refractive index increases with decreasing molar volume; this may have a tendency for larger optical bandgap. The result obtained from the glass matrix indicates that erbium oxide-doped calcium sulfate ultra-phosphate may give important information for wider development of functional glasses.

In this research, DFT+U approach was used to investigate the performance of Iridium (Ir) and Boron (B) co-doped armchair (8, 8) Single-walled Carbon Nanotube (SWCNT). Calculations of the structural electronic and optical spectra analysis of the system under study were carried out using the ab’initio quantum simulations implemented in Quantum ESPRESSO and thermo_pw codes within the popular density functional theory. In the doping process, carbon atoms have been replaced by Ir and B atoms in the SWCNT, the investigations were done on the basis of distance of H2 (d) from the co-doped SWCNT at intervals of 6.12 Å, 6.45 Å and 6.77Å, variations of temperature, variations of external electric field, band gaps, optical adsorptions and binding energy variations were all taken in to account. It is found that Ir/B co-doping in pristine SWCNT significantly enhanced the H2 adsorption capacity of the SWCNT. Furthermore, an increase in temperature decrease the performance ability of the co-doped SWCNT, negative adsorptions intensities were recorded by temperature increase by 650, 700 and 750 0C, this can be termed as exothermic adsorption. Therefore it can be demonstrated that H2 by co-doped SWCNT undergoes endothermic adsorption under ambient temperature and shows exothermic adsorption under higher temperatures.

Structural, electronic, and optical properties of a new combined system of carbon and boron nitride nanotubes are studied using the DFT first principles as implemented in Quantum ESPRESSO codes. The corrections to the quasi-particle energies were studied via GW hybrid functional implemented in the YAMBO code within the many-body perturbation theory. The studies were performed under different interwall distances of 3.0 nm, 2.5 nm, and 1.5 nm between CNTs and BNNTs. The results showed that the structural properties demonstrated high stability of the double-walled carbon boron nitride nanotube (DWCBNNT) systems under interwall distance (IWD) of 3.00 nm, 2.50 nm, and 1.50 nm. Results also demonstrated an inverse variation between the IWD and the diameter of the DWCBNNT system. In terms of the electronic properties, all three configurations of the DWCBNNTs reveal semiconducting behavior under KS-DFT showing a direct band gap of 3.30 eV, 1.79 eV, and 0.81 eV under IWD of 3.0 nm, 2.5 nm, and 1.5 nm, respectively. Furthermore, the band gap of the DWCBNNT increases with an increase in IWD (decrease in inner tube diameter) and decreases with a decrease in IWD (increase in inner tube diameter). In all three cases, the bands are formed by the molecular orbitals of the armchair CBNNT which are transformed to a series of continuous energy levels; the behaviors of electrons that formed the heterostructure are related to the behavior of electrons in B, C, and N atoms. From the optical properties perspective, the studies were conducted in parallel and perpendicular directions to the nanotubes’ axes. The presence of static dielectric functions in parallel direction at 3.3, 3.4, and 4.5 for nanotubes under 3.0 nm, 2.5 nm, and 1.5 nm demonstrated optical refraction. Refractions were also observed in directions perpendicular to the nanotubes. Furthermore, optical reflections occur when there is a higher absorption. The ability of these CBNNT hybrid systems to refract in all directions revealed the most exciting properties of the armchair CBNNT suitable to be used in magnifying glass materials. The findings further imply that the optical absorption coefficient is inversely related to the diameter of the nanotubes and is directly correlated to the band gap.