Impact of Thermal Treatment on the Surface of Na0.5Bi0.5TiO3-Based Ceramics

Thermal etching is a widely accepted surface treatment method for studying microstructure in Na0.5Bi0.5TiO3-based compositions. Surprisingly, besides the flat pattern of grains (suitable for evaluating ceramics’ microstructure), images illustrating well-expressed relief and even microstructure consisting of partly bonded cubic-shaped grains are also found among the micrographs presented in various publications. The present paper shows that this different surface character in Eu-modified Na0.5Bi0.5TiO3 can be obtained through thermal treatment across a wide range of temperatures. At higher temperatures, remarkable growth of cubic-shaped grains on the surface is observed. This growth affects the grain size distribution on the surface more than it does within the bulk of a sample. Such micrographs cannot be used to characterise the microstructure of dense ceramics. Intensive growth of TiO2 inclusions at high thermal treatment temperatures is also observed, revealing substantial evaporation of Bi and Na from the surface of a ceramic sample, but not from its core part.

Features of electric and viscoelastic parameters of erythrocytes in patients with inflammatory intestinal diseases

The aim of this work is to study the features of the electrical and viscoelastic parameters of erythrocytes in patients with inflammatory bowel diseases (ulcerative colitis, Crohn’s disease, unclassified colitis), taking into account the stage of the disease for possible use in differential diagnosis.The electrical and viscoelastic parameters of erythrocytes were studied using dielectrophoresis in 109 patients with IBD, mean age 37,7 + 11,7 years (50 patients with ulcerative colitis (UC), 41 with Crohn’s disease (CD), 18 with unclassified colitis (UCC) and 53 conditionally healthy, comparable in age and sex with the main groups.Red blood cells of individuals with IBD differed from those in the comparison group by a smaller average diameter, an increased proportion of deformed, spherocytic cells with a changed surface character with a reduced ability to deform, a lower level of surface charge of cells, an altered membrane structure with an increased ability to conduct electric current, prone to destruction and the formation of aggregates (p <0,0001–0,05).Analysis in individual groups with IBD in the acute stage, taking into account the therapy, revealed significant differences between the forms of IBD: in patients with Crohn’s disease, in contrast to patients with UC, red blood cells had lower values of the amplitude of deformation, capacity, dipole moment, and velocity of movement of cells towards electrodes, the proportion of discocytes, polarizability at most of the frequencies of the electric field (p <0,00001–0,05). On the contrary, the summarized indicators of rigidity, viscosity, electrical conductivity, aggregation and destruction indices were higher in CD than in UC (p <0,0001–0,05). CD patients had a greater number of deformed cells with altered surface character (p <0,00001).The features of the electrical and viscoelastic parameters of erythrocytes in patients with differentnosological forms of IBD can be used for the differential diagnosis of ulcerative colitis and Crohn’s disease in case of colon lesions, in the long term — for verification of the diagnosis in unclassified colitis.

Detailed numerical study of soot surface growth and oxidation in laminar diffusion flames

he focus of the present study is to obtain detailed knowledge of the soot formation and oxidation processes in laminar diffusion flames. The present work studies the effects of various flame properties on soot growth and oxidation, and how they affect a flame’s sooting behaviour. Numerically modelling of soot formation in laminar coflow diffusion flames of vaporized gasoline/ethanol blends at atmospheric pressure is performed. The numerical results are compared with experimental data to gain improved understanding of ethanol addition to gasoline on soot formation. Four gasoline/ethanol blends are investigated to quantify how soot loading varies with the amount of ethanol blending in the fuel. The results of experimental and numerical modelling agree relatively well in terms of the levels of soot volume fraction. Both results show a decrease in soot loading as more ethanol is added in the fuel stream. The work continues by numerically studying the oxidation of soot in laminar ethylene/air coflow diffusion flames. A new model for soot oxidation, a complex process in numerical soot modelling, is developed based on the observation that soot ageing reduces surface reactivity. Using this new model, it is possible to capture the correct behaviour of both smoking and non- smoking flames in various flame configurations. Along with a detailed soot sectional model, the new model predicts the correct soot volume fractions, smoke emission characteristics, and primary particle diameters for different flames without any variation in model parameters. The work extends to study soot surface reactivity in the growth and oxidation regions. Laminar ethylene/air and methane/air coflow diffusion flames are numerically studied to develop a unique soot surface reactivity model. A newly developed surface character model simultaneously accounts for soot surface reactivity in surface growth and oxidation by considering soot ageing and its effects on the particle surface. The new model, which eliminates tuning of one modelling parameter, reconciles the quantification of the evolving soot surface character for both growth and oxidation. The model is shown to be uniquely capable of predicting soot concentrations and smoke emissions within experimental uncertainty in a wide range of laminar diffusion sooting flames.

Detailed numerical study of soot surface growth and oxidation in laminar diffusion flames

he focus of the present study is to obtain detailed knowledge of the soot formation and oxidation processes in laminar diffusion flames. The present work studies the effects of various flame properties on soot growth and oxidation, and how they affect a flame’s sooting behaviour. Numerically modelling of soot formation in laminar coflow diffusion flames of vaporized gasoline/ethanol blends at atmospheric pressure is performed. The numerical results are compared with experimental data to gain improved understanding of ethanol addition to gasoline on soot formation. Four gasoline/ethanol blends are investigated to quantify how soot loading varies with the amount of ethanol blending in the fuel. The results of experimental and numerical modelling agree relatively well in terms of the levels of soot volume fraction. Both results show a decrease in soot loading as more ethanol is added in the fuel stream. The work continues by numerically studying the oxidation of soot in laminar ethylene/air coflow diffusion flames. A new model for soot oxidation, a complex process in numerical soot modelling, is developed based on the observation that soot ageing reduces surface reactivity. Using this new model, it is possible to capture the correct behaviour of both smoking and non- smoking flames in various flame configurations. Along with a detailed soot sectional model, the new model predicts the correct soot volume fractions, smoke emission characteristics, and primary particle diameters for different flames without any variation in model parameters. The work extends to study soot surface reactivity in the growth and oxidation regions. Laminar ethylene/air and methane/air coflow diffusion flames are numerically studied to develop a unique soot surface reactivity model. A newly developed surface character model simultaneously accounts for soot surface reactivity in surface growth and oxidation by considering soot ageing and its effects on the particle surface. The new model, which eliminates tuning of one modelling parameter, reconciles the quantification of the evolving soot surface character for both growth and oxidation. The model is shown to be uniquely capable of predicting soot concentrations and smoke emissions within experimental uncertainty in a wide range of laminar diffusion sooting flames.

Structural Analysis of Spike Protein Mutations in an Emergent SARS-CoV-2 Variant from the Philippines

A SARS-CoV-2 emergent lineage with multiple signature mutations in the Spike protein region was recently reported with cases centered in Cebu Island, Philippines. Whole genome sequencing revealed that the 33 samples with the Ph-B.1.1.28 emergent variant merit further investigation as they all contain the E484K, N501Y, and P681H Spike mutations previously found in other variants of concern such as the South African B.1.351, the Brazil P.1 and the UK B.1.1.7 variants. This is the first known report of these mutations co-occurring in the same virus. The possible implications of the mutations found in the Spike protein were analyzed for their potential effects on structure, stability, and molecular surface character. The analysis suggests that these mutations could significantly impact the possible interactions of the Spike protein monomer with the ACE2 receptor and neutralizing antibodies and warrants further clinical investigation. Some of the mutations affecting the N and C terminal domains may have effects on Spike monomer and trimer stability. This report provides insights on relevant targets for the design of future diagnostics, therapeutics and vaccines against the evolving SARS-CoV-2 variants in the Philippines.

Development of Novel Polyamide-Imide/DES Composites and Their Application for Pervaporation and Gas Separation

Novel polymer composites based on polyamide–imide Torlon and deep eutectic solvent (DES) were fabricated and adapted for separation processes. DES composed of zinc chloride and acetamide in a ratio of 1:3 M was first chosen as a Torlon-modifier due to the possibility of creating composites with a uniform filling of the DES through the formation of hydrogen bonds. The structure of the membranes was investigated by scanning electron microscopy and X-ray diffraction analysis; thermal stability was determined by thermogravimetric analysis and mass spectrometry. The surface of the composites was studied by determining the contact angles and calculating the surface tension. The transport properties were investigated by such membrane methods as pervaporation and gas separation. It was found that the inclusion of DES in the polymer matrix leads to a significant change in the structure and surface character of composites. It was also shown that DES plays the role of a plasticizer and increases the separation performance in the separation of liquids and gases. Torlon/DES composites with a small amount of modifier were effective in alcohol dehydration, and were permeable predominantly to water impurities in isopropanol. Torlon/DES-5 demonstrates high selectivity in the gas separation of O2/N2 mixture.

Depletion forces drive reversible capture of live bacteria on non-adhesive surfaces

Dissolved polymer can drive the reversible adhesion of living bacteria on a non-adhesive surface, defeating the non-adhesive underlying surface character.

Effect of Grain Size in Silica Blasting Processes on the Surface Roughness of Medical Grade SS 316L

The paper presents the effect of size and repetition process on silica blasting on the surface character of Medical Grade SS316L. In this study, topography and surface roughness of SS316L will be evaluated both using optical and stylus methods. Medical Grade SS316L was blasted using silica sand with a mesh size of 10-30 (then called K), mesh 40-60 (then called S), and mesh 70-90 (then called H). Silica blasting processes was carried out on the surface of Medical Grade SS316L at room temperature, 90° of nozzle direction, and 7 bar of nozzle pressure. The silica blasting process was carried out by varying the treatments of K, S, H, KH, and SH for 10 minutes each. The results show that roughness increases with the size of silica sand, moreover the repetition of the H process on the K and S (KH and SH process) will refine the surface roughness of the results of S and K processes but when compared to H is relatively coarse.

Surface Thermo-Dynamic Characterization of Poly (Vinylidene Chloride-Co-Acrylonitrile) (P(VDC-co-AN)) Using Inverse-Gas Chromatography and Investigation of Visual Traits Using Computer Vision Image Processing Algorithms

The Inverse Gas Chromatography (IGC) technique has been employed for the surface thermo-dynamic characterization of the polymer Poly(vinylidene chloride-co-acrylonitrile) (P(VDC-co-AN)) in its pure form. IGC attributes, such as London dispersive surface energy, Gibbs free energy, and Guttman Lewis acid-base parameters were analyzed for the polymer (P(VDC-co-AN)). The London dispersive surface free energy ( γ S L ) was calculated using the Schultz and Dorris–Gray method. The maximum surface energy value of (P(VDC-co-AN )) is found to be 29.93 mJ·m − 2 and 24.15 mJ·m − 2 in both methods respectively. In our analysis, it is observed that the γ S L values decline linearly with an increase in temperature. The Guttman–Lewis acid-base parameter K a , K b values were estimated to be 0.13 and 0.49. Additionally, the surface character S value and the correlation coefficient were estimated to be 3.77 and 0.98 respectively. After the thermo-dynamic surface characterization, the (P(VDC-co-AN)) polymer overall surface character is found to be basic. The substantial results revealed that the (P(VDC-co-AN)) polymer surface contains more basic sites than acidic sites and, hence, can closely associate in acidic media. Additionally, visual traits of the polymer (P(VDC-co-AN)) were investigated by employing Computer Vision and Image Processing (CVIP) techniques on Scanning Electron Microscopy (SEM) images captured at resolutions ×50, ×200 and ×500. Several visual traits, such as intricate patterns, surface morphology, texture/roughness, particle area distribution ( D A ), directionality ( D P ), mean average particle area ( μ a v g ) and mean average particle standard deviation ( σ a v g ), were investigated on the polymer’s purest form. This collective study facilitates the researches to explore the pure form of the polymer Poly(vinylidene chloride-co-acrylonitrile) (P(VDC-co-AN )) in both chemical and visual perspective.