Effect of Ce3+ Ions Doped NiFe2O4 Magnetic Nanoparticles on Photocatalytic Degradation of Rhodamine B and Antibacterial Activities

In this study, spinel NiCexFe2–XO4 (x = 0.0 - 0.5) nanoparticles (NPs) was synthesized by microwave combustion technique (MCT) utilizing the fuel of Aloe vera plant extract. The establishment of spinel cubic crystal structure was ensured by powder X-ray diffraction (PXRD) technique. The particles like nanostructured morphology were confirmed by high-resolution scanning electron microscope (HRSEM). Energy dispersive X-ray (EDX) studies confirmed the formation of spinel ferrite structure and ensured that no other elements were present. Magnetic parameters such as remanant magnetisation (Mr), coercivity (He) and saturation magnetization (Ms) were calculated from the magnetic hysteresis (M-H) loops, which exhibited ferromagnetic behaviour. The photocatalytic behavior was investigated by visible light treatment for the photocatalytic degradation (PCD) of rhodamine B (Rh-B) dye and the sample NiCe0.3Fe1.7O4 exhibits higher PCD efficiency (93.88%) than other compositions. The antibacterial activities of gram-positive S. aureus, B. subtilis, gramnegative K. pneumonia and E. coli have been investigated using undoped and Ce3+ substituted NiFe2O4 NPs and observed higher activity, which indicated that, they can be used in the bio-medical applications.

IDENTIFICATION OF CHARACTER AND INTENSITY OF WEAR OF PVD COATED TWIST DRILLS IN DRILLING OF C 45 MATERIAL

This article is aimed to investigation of four different PVD coatings of STATON company in order to determine a wear behavior on twist drills when drilling C45 material. A pearlite-ferrite structure of C45 material is common material for automotive industry and highly abrasive to cutting tools. Our comparative study is focused on flank wear of the cutting wedge of observed drills deposited at STATON. The article shows differences in chemical composition and their effects on wear behavior at the corner of the drill and along the cutting edge. We also demonstrate that chemical composition has significant influence on the temperature of a build-up edge during cutting.

Structural, Optical and Magnetic Properties of Nickel-Copper Ferrite NixCu1-xFe2O4

Nickel-copper ferrite nanoparticles NixCu1-x Fe2O4 with values x = 0.3, 0.5,0.7 fabricated by combustion method . X-ray diffraction (XRD) analyzes confirmed the formation of the ferrite structure. The average size of crystals was estimated to range from 39 to 44 nm. The particle morphology was detected and interpreted by the FSEM scanning microscope and the porosity characteristic of the ferrite structure based on the combustion method was observed. The FTIR analysis was performed to investigate the bonds in which the tensile vibrational mode of the tetrahedral site in the range of the wavelength of 500-600 cm-1 .The magnetic properties of nanoparticles were investigated using VSM analysis and the effect of increasing of copper ion on MS saturation magnetization and HC coercivity force was investigated. With respect to the saturation magnetization values for the synthesized samples, it was observed that by increasing the Cu content from x = .3 to x = .5 the saturation magnetization decreased and then increasing with increasing Cu content such that at x = .5, we had the lowest saturation magnetism. Reduction of saturation magnetization Copper ions occupy ferric ions in tetrahedral sites and iron ions are transferred to octahedral sites. The results of UV-Vis indicate to complete absorption in the samples. The linearity of the edge of the absorption spectrum relates to a direct energy band gap and the effect of increasing copper ions on ferrite conductivity was investigated.

Vortex beam manipulation through a tunable plasma-ferrite metamaterial

This paper is devoted to the study of vortex beam transmission from an adjustable magnetized plasma-ferrite structure with negative refraction index. We use the angular spectral expansion technique together with the $$4\times 4$$ 4 × 4 matrix method to find out the transmitted intensity and phase profiles of incoming Laguerre-Gaussian beam. Based on numerical analysis we demonstrate that high transparency and large amount of Faraday rotation in the proximity of resonance frequency region, reverse rotation of spiral wave front, and side-band modes generation during propagation are the remarkable features of our proposed structure. These controllable properties of plasma-ferrite metamaterials via external static magnetic field and other structure parameters provide novel facilities for manipulating intensity and phase profiles of vortex radiation in transmission through the material. It is expected that the results of this work will be beneficial to develop active magneto-optical devices, orbital angular momentum based applications, and wavefront engineering.

GTA Welding Dissimilar of AISI 309 to AISI 201 Stainless Steels by Using AISI 308L Filler Metals

The aim of the study to investigate the effect of welding current on the microstructure and mechanical properties of gas tungsten arc welding (GTAW) for dissimilar austenite Stainless steel (AISI 309 and 201). Three models of welding currents have been used and their effect on microstructure and mechanical properties investigated. The results reveal that increase of welding currents improved the ultimate tensile strength (UTS) however, the hardness of the weld zone and Heat Affected Zone (HAZ) are similar. On the other hand, the microstructure of base metal AISI 309 and 201of austenite, ferrite structure, and ẟ ferrite of AISI 309 stainless steel were observed.

Effect of Cu Substitution on Magnetic Properties of Co0.6Ni0.4Fe2O4 Nanoferrites

This work is focusing on synthesizing the cobalt nanoferrite materials substituted by copper forming Co0.6Ni0.4-xCuxFe2O4 with x = 0.0, 0.1, and 0.3 using the sol-gel auto-combustion method. The phase analysis of XRD showed the spinel structure with the lattice parameter in the range 8.36-8.39 Å. FESEM image showed the grain size initially decreasing and then increasing with Cu concentration. The FTIR curve's two absorption bands in the specified range of frequency assured the spinel nano ferrite structure. The values of remanent ratios obtained from VSM showed their isotropic nature forming single domain ferrimagnetic particles.

Experimental Evaluation of the Effects of Structural Changes on the Vibration Properties of CK35 Steel

The microstructure of some components which operate in high-temperature conditions (e.g. boiler components, turbine blades used in gas power plants, jet engines and reactors) is subjected to changes in long run, which leads to a degradation in the mechanical properties of these components and consequently, reduces their lifecycle. Therefore, it is so useful to detect the changes in the microstructure of these parts during their operation, employing an easy, fast and non-destructive method to determine their remaining life. In this study, we evaluate the effects of the microstructural changes on natural frequencies and the damping coefficient of CK35 steel, employing the experimental modal test. We aim to use the method for power plant components, if it has significant effects. To do so, we applied spheroidization heat treatment on CK35 steel samples having a primary structure of ferrite-pearlite for 24 and 48 hours. Then, we carried out the experimental modal test on samples having different metallurgical structures, but with the same dimensions and weights. According to the findings, the spherical ferrite-carbide particles in the ferrite structure increase the natural frequencies and damping coefficient. These tests show that the structural changes in this type of steel result in slight changes in the values of natural frequencies; however, it significantly changes the damping frequencies.