Homogenization Modes Effect on Mechanical Properties and Corrosive Characteristics of the Rolled Products from Al-Mg (1570) Aluminum Alloy with Addition of Scandium and Zirconium

Objective of the study: study of various homogenization modes effects on mechanical and corrosive properties of rolled sheets from Al-Mg system alloy 1570 with additions of zirconium and scandium transition metals. The sheets were produced in laboratory conditions from the ingot, cast in production DC mold based on the commercial production practices and treatment modes. 4 homogenization modes, 2 tempers H12 and H321, and several modes of stabilization annealing in the temperature range from 240 °C to 325 °C have been reviewed. The samples have been comprehensively examined using optic and electron scanning microscope, mechanical properties were achieved by break test in compliance with ISO 6892-1, corrosion was examined using ASTM G66 and G67 standards. The curve of 1570 alloy sheets softening as the function of annealing temperature was constructed. It was demonstrated that the increasing temperature effect during homogenization leads to strength properties decrease and corrosion resistance improvement due to interdendritic segregation elimination. Among analyzed homogenization modes, 360 - 380 °C - 6 h mode is established as the most practical, and the sheets. produced without stabilization annealing, occurred to be the most resistant to exfoliation corrosion. The sheets, subjected to annealing at 260 °C - 2 h, show no traces of layer corrosion, but have pit corrosion locations rated as «PC» based on ASTM G-66 classification, such rating is unacceptable for the manufacture of products for use in the marine environment.

The Effect of Spray Distance on Porosity, Surface Roughness and Microhardness of WC-10Co-4Cr Coatings Deposited by HVOF

The paper presents the computational studies on the microstructure of WC-Co-Cr coatings deposited by High Velocity Oxy Fuel spraying (HVOF). The study covers the porosity assessment according to ASTM E2109-01 standard, carried out in ImageJ software, in terms of volume porosity, size and shape of the pores. The evaluation was preceded by scanning electron microscope (SEM) observations at magnifications of 2000x and 5000x. Additionally, topography analysis has been performed by confocal laser scanning microscope (CLSM), and the surface roughness Ra was evaluated by the contact method with use of a stylus profilometer. Finally, the influence of porosity was observed for coatings microhardness HV0.3. According to the results, the total closed porosity was found to be in the range of 5.01 vol.% and 5.38 vol.%. The dominated pores in the coatings were of size 0.1-1.0 μm. Studies showed that HVOF process enabled deposition of dense coatings, characterized by homogenous distribution of pores and low roughness.

Albumen-mediated Green Synthesis of ZnFe2O4 Nanoparticles and Their Physico-Chemical Properties

Spinel ferrites with general formula AB2O4 possess charming magnetic and electrical properties owing to their thermal and chemical steadfastness. Spinel zinc ferrite (ZnFe2O4) nanoparticles have attracted massive attention due to their unusual amalgamation of properties, especially magnetic properties, where these properties are equipped as suitable candidates in the field of electronics. Here, a simple self-combustion technique is made with the assistance of albumen to synthesize nanocrystalline zinc ferrite (ZnFe2O4) particles. The egg white (albumen) that is used in the synthesis process plays the fuel role in the process of combustion. The results of the powder X-ray diffraction (PXRD) and Fourier Transform Infrared Spectroscopy (FTIR) suggested that the synthesized nanoparticles are of single phase and show spinel structure. The photoluminescence studies reported a doublet peak at around 360-380 nm. The functional groups present in the synthesized nanoparticles were revealed from FTIR data. EDX findings give an account of the percentage composition of the elements Fe, Zn and O present in the synthesized sample. High-resolution Scanning Microscope (HRSEM) reveals the agglomerated coalescence nature of ferrite nanoparticles. Keywords: Ferrite, PXRD, FTIR, HRSEM, EDX Albumen.

3D-Printed Portable Robotic Mobile Microscope for Remote Diagnosis of Global Health Diseases

Microscopy plays a crucial role in the diagnosis of numerous diseases. However, the need for trained microscopists and pathologists, the complexity of pathology, and the accessibility and affordability of the technology can hinder the provision of rapid and high-quality diagnoses and healthcare. In this work, we present an affordable, 3D-printed, portable, robotic, mobile-based slide scanning microscope. The proposed device is composed of electronic, mechanical, and optical modules operated via smartphone with a control app. The device is connected and fully integrated with a telemedicine web platform, where digitized microscopy images can be remotely visualized and analyzed. The robotic scanner, which has approximately 1-µm resolution, has been evaluated in two clinical scenarios with histology and stool samples. The results showed sufficient image quality for performing a proper diagnosis in all cases under study.

Peptides Derived from Angiogenin Regulate Cellular Copper Uptake

The angiogenin protein (ANG) is one of the most potent endogenous angiogenic factors. In this work we characterized by means of potentiometric, spectroscopic and voltammetric techniques, the copper complex species formed with peptide fragments derived from the N-terminal domain of the protein, encompassing the sequence 1-17 and having free amino, Ang1-17, or acetylated N-terminus group, AcAng1-17, so to explore the role of amino group in metal binding and cellular copper uptake. The obtained data show that amino group is the main copper anchoring site for Ang1-17. The affinity constant values, metal coordination geometry and complexes redox-potentials strongly depend, for both peptides, on the number of copper equivalents added. Confocal laser scanning microscope analysis on neuroblastoma cells showed that in the presence of one equivalent of copper ion, the free amino Ang1-17 increases cellular copper uptake while the acetylated AcAng1-17 strongly decreases the intracellular metal level. The activity of peptides was also compared to that of the protein normally present in the plasma (wtANG) as well as to the recombinant form (rANG) most commonly used in literature experiments. The two protein isoforms bind copper ions but with a different coordination environment. Confocal laser scanning microscope data showed that the wtANG induces a strong increase in intracellular copper compared to control while the rANG decreases the copper signal inside cells. These data demonstrate the relevance of copper complexes’ geometry to modulate peptides’ activity and show that wtANG, normally present in the plasma, can affect cellular copper uptake.

Solid-Phase Reduction and Separation of Iron and Phosphorus from Manganese Oxides in Ferromanganese Ore

The possibility of joint solid-phase reduction of iron and phosphorus from ferromanganese ore has been experimentally confirmed. Solid-phase reduction was performed at a temperature of 1000°C and exposure time of 2-5 hours, in a CO atmosphere, also produced the separation of the reduction products by melting. The distribution of iron and phosphorus was studied using an electron scanning microscope. The phase analysis of the samples was studied using a Rigaku Ultima IV X-ray diffractometer. The results were processed using the "Match" software. Reducing roasting in a CO atmosphere provides a transition from the oxide phase to the metallic phase of only iron and phosphorus without loss of manganese, thus increasing the concentration of MnO oxide in the residual oxide phase of the ore.