Materials Technology Reports

Manganese and iron-doped π-YBO₃ have been synthesized using a modified epoxide-mediated gel method. The PXRD pattern evaluated the formation of the desired phase and the structural changes. EDS spectra determined the elemental analysis of undoped and doped samples. Raman spectra observed the stretching and bending modes of B-O bonds. The direct band gaps for doped samples were 1.47 and 2.07 eV, respectively, lower than the band gap value of 5.81 eV for π-YBO₃. The green and blue indigo emission bands were observed in the photoluminescence spectra. Doped samples showed good magnetic properties as they are antiferromagnetic and ferromagnetic at low temperature (T = 5 K) M-H plot and SQUID measurement. An indigenously built Sawyer-Tower circuit is used to measure ferroelectric hysteresis. Photodegradation studies of RhB were conducted under UV-visible irradiation.

This study compared gas-metal arc welding (GMAW) and laser beam welding (LBW) for the superposed joining of two low-carbon steels. The motivation was to reduce the visible defects (notches) in the external part of one of the sheets. Both welding processes produced sound welds characterized by ferrite and pearlite; however, the notch disappeared when LBW was used. The hardness values of the fusion and heat-affected zones were similar for both processes, but the tensile strengths were very different. The shear tensile strengths of the LBW and GMAW were 415 and 84 MPa, respectively. Finite element analysis simulations indicated a more diffuse distribution of the von Mises stress throughout the welded component. The GMAW FEA model also presented a defect because of excessive heat transfer and residual stresses. In conclusion, LBW can replace GMAW in this particular case with improvements in appearance, productivity, and mechanical strength.

This study examined the surfaces of non-passivated and passivated tinplate samples, as well as the impurities present on them, using SEM, EDS, and GDOES. Additionally, solutions were analyzed using ICP in order to identify any correlations between the elements present in the solutions and on the strip surfaces. The results from GDOES indicated the presence of unwanted elements, such as Sn, S, Cr, N, P, Zn, Fe, Mn, C, and Si, on both the passivated and non-passivated sample surfaces. SEM analysis of the passivated sample revealed light and dark regions in parallel lines, which were observed ahead of the rolling direction. EDS analysis indicated that the light areas were rich in Sn while the dark areas were rich in Fe, and C was identified as an unwanted element in both areas. O and Cr were only found in the dark areas. EDS analysis of the impurities revealed Na, S, Cl, Ca, Mg, Si, N, and Al as unwanted elements. The results suggest that unwanted elements are transferred from the steel strip surface to different solutions in the tinplate line, causing pollution in various solutions.

In this study, Buxus sempervirens leaf ingredient (LP) and the carbon (LC) and the ash (LA) were obtained, which are the bio-originated materials. Carbon and ash obtained from this natural plant were prepared by heating and pyrolysis for 2 h at 250 ℃ and 700 ℃, respectively. Then, the solution casting method was used to prepare the composites of these bio-additives with polystyrene. Next, the effects of the additives on diffuse reflectance spectroscopy (DRS) and X-ray diffraction (XRD) spectra of polystyrene were investigated. In addition, the additives led to noticeable changes in X-ray diffraction results, implying a change in the morphology of the polymer. All of these observations imply the uniform formation of the polystyrene (PS) composites with the micro and bio-fillers.

Polymeric membranes are widely used for treatment of lean stream in chemical process industries. These membranes are used in different configurations such as tubular, plate & frame, disc-tube, spiral and capillary/hollow-fibre. Membrane modules with capillary/hollow-fibre configuration appears promising in ultrafiltration applications due to its relatively higher packing density, ease of backwashing, ease of cleaning and lower pressure drops since it can be operated at laminar flow regime with high cross-flow velocity. Hence, efforts are being made by researchers to make capillary/hollow-fibre membrane modules from various polymers, ranging from most hydrophilic polyacrylonitrile (PAN) to super-hydrophobic polypropylene (PP) and polytetrafluorethylene (PTFE). Here, we discuss the qualifying properties of the polymeric materials suitable to spin into capillary/hollow-fibre ultrafiltration membranes. Selection of polymers for making fibres requires in-depth knowledge of properties of base polymer and its processability/fabricability. The important properties to be considered for making capillary/hollow-fibre membrane are intrinsic structural properties of the base polymer like degree of crystallinity, tensile strength, tensile modulus, etc. The functional properties such as permeability, hydrophilicity/hydrophobicity etc. also plays role in selecting polymer for a given application. The polymer should also have appreciable dissolution in available solvents or should have degradation temperature higher than melting point so that it can be processed through appropriate membrane preparation process.

This article proposes to analyze the formation and “morphogenesis” during desolvation of drops on MALDI targets and target chips using 2D correlation spectral analysis based on the two-dimensional Fourier transform and wavelet spectroscopy methods in the real and imaginary regions. The results of the correlation-spectral and wavelet analysis are shown in the illustrations in the text of the article.

This review addresses the problem of reaction-diffusion effects and spatiotemporal oscillations in fiber-like and wire-like systems under the electron beam in SEM and in the presence of electric field in some special AFM techniques, such as current sensing atomic force microscopy (CS-AFM)/conductive atomic force microscopy (C-AFM), electrostatic force microscopy (EFM) and Kelvin probe force microscopy (KPFM) also known as surface potential microscopy. Some similar reaction-diffusion effects also can be observed in scanning capacitance microscopy (SCM), scanning gate microscopy (SGM), scanning voltage microscopy (SVM) and piezoresponse force microscopy (PFM). At the end of this paper the authors provide analysis of their own results and approaches. In particular, the possibility of achieving the ion transfer controlled growth of cells along the ion concentration gradients in reaction-diffusion fibers and actuators is indicated. This fundamental idea is discussed within the framework of the implantable fiber “bioiontronics” and “neuroiontronics” controlled by acoustic and electrical signals that regulate the reaction-diffusion or chemical oscillation activity of such fiber structures as reaction-diffusion actuators and sensors. The literature review includes more than 130 references.