CFD modeling of slurry flow erosion wear rate through mitre pipe bend

Erosive wear caused by particulates slurry is one of the major concerns in the pipe bend which may results in the failure of the pipe flow system. In the present work, erosion wear rate through mitre pipe bend caused by silica sand particulates slurry has been investigated using ANSYS Fluent code. The solid spherical particulates of size 125 µm and 250 µm having density of 2650 Kg/m3, were tracked to compute the erosion wear rate using Discrete Phase Method (DPM) model. The particulates were tracked using Eulerian-Lagrange approach along with k-ɛ turbulent model for continuous fluid phase. The silica particulates were injected at solid concentration of 5% and 10% (by weight) from the pipe inlet surface for wide range of velocities viz. 1–8 ms−1. The erosion wear rate was computed through four computational erosion models viz. Generic, Oka, Finnie and Mclaury. Furthermore, the outcomes obtained through Generic models are verified through existing experimental data in the literture. Moreover, the results of DPM concentration, turbulence intensity and particle tracking were predicted to analyze the secondary flow behaviour through the bend cross section. Finally, the effect of particulate size, solid concentration and flow velocity were discussed on erosion wear rate through bend cross section. The findings show that the locality of maximum erosive wear is positioned at the extrados of the bend outlet cross section. Additionally, it is found that Mclaury model offers higher erosion rate as compared to the other models and provides benchmark for designing the slurry pipeline system.

Coherence Properties and Intensity Distribution of a Partially Coherent Lorentz–Gauss Beam Emerging from the Axicon

The propagation of a partially Lorentz–Gauss beam in a uniform-intensity diffractive axicon is studied according to the Huygens–Fresnel principle, the Hermite–Gaussian expansion of a Lorentz function, and using the stationary phase method. We have derived the intensity equation of a partially coherent Lorentz-Gauss beams propagating through uniform-intensity diffractive axicon, and we proved mathematically that it is the superposition of Bessel beams of various orders after emerging from axicon, using Hermite’s function series and the Bessel function integral formulas. The results show that the intensity distribution of the diffracted beam is the intensity pattern evolved from a Lorentz–Gauss shaped spot into a Gaussian-shaped spot at any position on the focal length of the axicon, and the intensity distribution of a partially Lorentz–Gauss beam generated by an axicon becomes uniform by increasing the beam width and more uniform and constant with the larger coherence width.

Distortion correction for wide angle holographic projector

This letter presents distortion correction method enabling distortion minimized, large size image in wide angle holographic projector. The technique applies numerical predistortion of an input image used for hologram generation. It is based on estimation of distortion coefficients by comparing optically reconstructed point test chart with the original one. Obtained experimental results prove that the technique allows reconstruction of high-quality image. Full Text: PDF ReferencesM. Makowski, Experimental Aspects of Holographic Projection with a Liquid-Crystal-on-Silicon Spatial Light Modulator, in Holographic Materials and Optical Systems, M. Kumar, ed. (IntechOpen, 2019). CrossRef H. Pang, A. Cao, W. Liu, L. Shi, and Q. Deng, "Effective method for further magnifying the image in holographic projection under divergent light illumination", Appl. Opt. 58, 8713 (2019). CrossRef Y. Qi, C. Chang, and J. Xia, "Speckleless holographic display by complex modulation based on double-phase method", Opt. Express 24, 30368 (2016). CrossRef E. Buckley, "Holographic Laser Projection", J. Display Technol. 99, 1 (2010). DirectLink M. Chlipała, T. Kozacki, H. Yeom, J. Martinez-Carranza, R. Kukołowicz, J. Kim, J. Yang, J. Choi, J. Pi, and C. Hwang, "Wide angle holographic video projection display", Opt. Lett. 46, 4956 (2021). CrossRef Z. He, X. Sui, L. Cao and G. Jin, "Image-Distortion Correction Algorithm for Computer-Generated Holographic Display," 2018 IEEE 27th International Symposium on Industrial Electronics (ISIE), 1331 (2018). CrossRef A. Kaczorowski, G.S. Gordon, A. Palani, S. Czerniawski and T.D. Wilkinson, "Optimization-Based Adaptive Optical Correction for Holographic Projectors", J. Display Technol. 11(7), 596 (2015). CrossRef Z. He, X. Sui, G. Jin, L. Cao, "Distortion-Correction Method Based on Angular Spectrum Algorithm for Holographic Display", IEEE Trans. Industr. Inform. 15, 6162 (2019). CrossRef O. Mendoza-Yero, G. Mínguez-Vega, and J. Lancis, "Encoding complex fields by using a phase-only optical element", Opt. Lett. 39, 1740 (2014). CrossRef T. Kozacki, K. Falaggis, "Angular spectrum method with compact space–bandwidth: generalization and full-field accuracy", Appl. Opt. 55, 5014 (2016). CrossRef

Screening study of the antihyperglycemic action of new solid quercetin dispersions

The aim – to screen new solid dispersions of quercetin for the presence of antihyperglycemic action and to identify the most active substances that are promising for the creation of antidiabetic drugs. Materials and methods. The object of the study was 4 new solid dispersions of quercetin, developed at the National University of Pharmacy. Solid dispersions of quercetin were prepared by the liquid-phase method; hydroxypropyl methylcellulose (HPMC) or polyvinylpyrrolidone (PVP) in ratios of 1:1 and 1:2 were used as a carrier. The antihyperglycemic effect of the studied substances at a dose of 50 mg / kg was assessed in rats by the ability to lower blood glucose levels after carbohydrate loading in a model of impaired glucose tolerance induced by dexamethasone and in experimental type 2 diabetes mellitus induced by dexamethasone. Results. It was found that with impaired glucose tolerance, a solid dispersion of quercetin with HPMC (1:1) showed a pronounced antihyperglycemic effect – the glucose level 30 minutes after glucose load significantly decreased by 28 % and did not differ from the action of metformin, which was confirmed by the value of the area under glycemic crooked. When solid dispersions with PVP (1:1 and 1:2) were used, the antihyperglycemic effect was less pronounced. In a model of type 2 diabetes mellitus, a significant antihyperglycemic effect was found only in a solid dispersion of quercetin with HPMC (1:1) at the metformin level, which indicates an increase in the solubility and absorption of quercetin. Conclusions. A pronounced antihyperglycemic effect at the metformin level was found in a solid dispersion of quercetin with HPMC in a 1:1 ratio with impaired glucose tolerance and type 2 diabetes mellitus. It has been proven that a solid dispersion of quercetin with HPMC is a promising substance for creating a monocomponent drug or for inclusion in a new antidiabetic combined drug

Synthesis, Property Characterization and Photocatalytic Activity of the Ag3PO4/Gd2BiTaO7 Heterojunction Catalyst under Visible Light Irradiation

A new type of Gd2BiTaO7 nanocatalyst (GBT) was synthesized by a high-temperature solid-phase method, and a heterojunction photocatalyst, which was composed of GBT and silver phosphate (AP), was prepared by the facile in-situ precipitation method for the first time. The photocatalytic property of GBT or the Ag3PO4/Gd2BiTaO7 heterojunction photocatalyst (AGHP) was reported. The structural properties of GBT and AGHP were characterized by an X-ray diffractometer, scanning electron microscope–X-ray energy dispersive spectra, an X-ray photoelectron spectrograph, a synchrotron-based ultraviolet photoelectron spectroscope, a Fourier transform infrared spectrometer, an UV-Vis diffuse reflectance spectrophotometer and an electron paramagnetic resonance spectrometer. The results displayed that GBT was well crystallized with a stable cubic crystal system and space group Fd3m. The lattice parameter or band gap energy of GBT was found to be a = 10.740051 Å or 2.35 eV, respectively. After visible light irradiation of 30 min, the removal rate of bisphenol A (BPA) reached 99.52%, 95.53% or 37.00% with AGHP as the photocatalyst, with Ag3PO4 and potassium persulfate (AP-PS) as photocatalysts or with N-doped TiO2 (NT) as a photocatalyst, respectively. According to the experimental data, it could be found that the removal rate of BPA with AGHP as a photocatalyst was 2.69 times higher than that with NT as a photocatalyst. AGHP showed higher photocatalytic activity for photocatalytic degradation of BPA under visible light irradiation compared with GBT or AP-PS or NT. The removal rate of total organic carbon (TOC) was 96.21%, 88.10% or 30.55% with AGHP as a photocatalyst, with AP-PS as photocatalysts or with NT as a photocatalyst after visible light irradiation of 30 min. The above results indicated that AGHP possessed the maximal mineralization percentage ratio during the process of degrading BPA compared with GBT or AP-PS or NT. The results indicated that the main oxidation radical was •OH during the process of degrading BPA. The photocatalytic degradation of BPA with AGHP as a photocatalyst conformed to the first-order reaction kinetics. This study provided inspiration for obtaining visible light-responsive heterojunction photocatalysts with high catalytic activity and efficient removal technologies for organic pollutants and toxic pollutants, and as a result, the potential practical applications of visible light-responsive heterojunction photocatalysts were widened. The subsequent research of thin-film plating of the heterojunction catalysts and the construction of complete photoluminescent thin-film catalytic reaction systems, which utilized visible light irradiation, could provide new technologies and perspectives for the pharmaceutical wastewater treatment industry.

Solid-phase synthesis of ytterbium zirconate using mechanical activation

Nanocrystalline ytterbium zirconate Yb4Zr3O12 was prepared by the solid-phase method using mechanical activation of stoichiometric mixture of zirconium and ytterbium oxides. Mechanical activation was carried out in an AGO-2 centrifugal-planetary mill at a centrifugal factor of 40 g for 10 min. The processes occurring during the calcination of the mechanically activated mixture of ytterbium and zirconium oxides in the range from 600 to 1300 °C were investigated using X-ray phase analysis, IR spectroscopy, and complex thermal analysis.

Targeted Separation of COX-2 Inhibitor from Pterocephalus hookeri Using Preparative High-Performance Liquid Chromatography Directed by the Affinity Solid-Phase Extraction HPLC System

Pterocephalus hookeri, as a kind of popular traditional Tibetan medicine, is reputed to treat inflammatory related diseases. In the present work, a cyclooxygenase-2 functionalized affinity solid-phase extraction HPLC system was developed and combined with preparative-HPLC for rapidly screening and separating cyclooxygenase-2 ligand from P. hookeri extracts. Firstly, ligands of cyclooxygenase-2 were screened from extracts by affinity solid-phase extraction HPLC system. Then directed by the screening results, the recognized potential active compounds were targeted separated. As a result, the major cyclooxygenase-2 inhibitor of P. hookeri was obtained with a purity of >95%, which was identified as sylvestroside I. To test the accuracy of this method, the anti-inflammatory activity of sylvestroside I was inspected in lipopolysaccharide-induced RAW 264.7 cells. The results show that sylvestroside I significantly suppressed the release of prostaglandin E2 with dose-dependent, which was in good agreement with the screening result of the affinity solid-phase method. This method of integration of screening and targeted separation proved to be very efficient for the recognition and isolation of cyclooxygenase-2 inhibitors from natural products.

Structural properties of TiO2-SnO2 thin films prepared by new pyrolysis solid-phase method

Nanoscale TiO2-SnO2 films with the Ti:Sn ratio 1:99, 3:97 and 5:95 mol%, respectively, were obtained by solid-phase low-temperature pyrolysis method. The synthesized materials were studied by X-ray phase analysis and scanning electron microscopy (SEM) analysis. Regardless of the modified agents’ concentration, the structure of cassiterite was observed for all synthesized materials. When studying the effect of synthesis parameters on the materials properties, it was shown that both an increase in the Ti4+ concentration and in the calcination temperature leads to an increase in the particle size.

Small-scale analysis to rank municipalities requiring slow-moving landslide risk mitigation measures: the case study of the Calabria region (southern Italy)

This paper proposes a three-phase method that combines multi-source (i.e. topographic, thematic, monitoring) input data in a GIS environment to rank—at small (1:250,000) scale—administrative units (e.g. municipalities) based on their exposure to slow-moving landslide risk within a selected area (e.g. a region) and, accordingly, detect those primarily requiring mitigation measures. The method is applied in the Calabria region (southern Italy) where several municipalities are widely affected by slow-moving landslides that systematically cause damage to buildings and infrastructure networks resulting in significant economic losses. The results obtained are validated based on the information gathered from previous studies carried out at large (municipal) scale. The work undertaken represents a first, fundamental step of a wider circular approach that can profitably facilitate the decision makers in addressing the issue of the slow-moving landslide risk mitigation in a sustainable way.