TiO2 nanoparticles are doped with three different concentrations of Mn, 2%, 4% and 6% respectively. Absorption edge of TiO2 is shifted from UV to visible region on amplification of Mn content. Room ...temperature photoluminescence spectra, excited at 320nm, exhibit band edge and visible emission peaks associated with self trapped excitons, oxygen defects, etc. Doping of Mn increases the width and decreases the intensity of the UV emission peak. Potential fluctuations of impurities increase the width and auger type non-radiative recombination decreases the intensity of the UV emission peak. The intensity ratio of the UV to defect emission band decreases on doping, indicating degradation of structural quality. Excitation of pure and doped nanoparticles at 390nm results in Mn2+ emission peaks at 525nm and 585nm respectively. Photoluminescence excitation spectra also indicate the presence of Mn2+ in the crystalline environment of TiO2. The oxygen defects and Mn related impurities act as efficient trap centers and increases the lifetime of the charge carriers.
► Doping of Mn increases the d-spacing of TiO2 nanoparticles. ► Characteristic d–d electronic transition of Mn2+ is observed in the absorption spectra. ► Doping of Mn quenches the UV and visible emission peaks of TiO2. ► Photoexcitation at 390nm generates emission peaks of Mn2+.
We consider applications of a new function, introduced by Kudryashov (Optik, 206:163550, 2020), to obtain solitary wave solutions of nonlinear PDEs arising in the domain of plasma physics, through ...their traveling wave reductions. The Kudryashov function,
R
, has several features which significantly assist symbolic computation specially in case of highly dispersive nonlinear equations. The method provides a simple, effective and straightforward algorithm for obtaining solitary wave solutions.
The modulus of elasticity and nano-hardness of TiB2-TiC-Al2O3 composite coatings deposited on AISI 1020 steel by combined self-propagating high-temperature synthesis and a laser cladding process were ...measured from load-displacement curves, resulting from nanoindentation testing. The fracture toughness (KIC) of the coatings was evaluated from the indentation method. A qualitative evaluation of the interfacial strength between the coating and substrate material was also performed by indentation method. Results indicated that the elastic modulus and fracture toughness of the composite coatings were in the range 230-280 GPa and 5.46-6.12 MPa.m1/2 respectively which were lower and higher than those of the individual constituent ceramics. The nano-hardness of the coating microstructure obtained was in the range 16-22 GPa and varied depending on the laser-processing parameter adopted. Indentation taken with high load at the coating-substrate interface indicated a strong interfacial bond between the coating and the steel substrate. An attempt has been made to correlate the wear rate of the coating with the H/E ratio.
The increasing attention to the environmental and health impacts of industrial activities by governmental regulations and by the growing awareness level in the society is forcing industrialists to ...reduce the use of mineral oil-based metalworking fluids as cutting fluid. Cutting fluids have been used extensively in metal cutting operations for the last 200 years. In the beginning, cutting fluids consisted of simple oils applied with brushes to lubricate and cool the machine tool. As cutting operations became more severe, cutting fluid formulations became more complex. There are now several types of cutting fluids in the market and the most common types can be broadly categorized as cutting oils or water-miscible fluids. In this review, the applicability of vegetable oil-based metalworking fluids in machining of ferrous metals has been undertaken. The advantages of metalworking fluids and its performances with respect to the cutting force, surface finish of work piece, tool wear and temperature at the cutting zone have been investigated. It has been reported in various literature that metalworking fluids, which are vegetable oil-based, could be an environmentally friendly mode of machining with similar performance obtained using mineral oil-based metalworking fluids.
► Higher material removal rate can be achieved with vegetable oil-based fluids. ► Vegetable oil-based fluids are environmentally friendly. ► Vegetable oil-based fluids performed satisfactorily during machining processes.
Applications of a new function introduced by Kudryashov Optik. 2020;206:163550 to obtain solitary wave solutions of nonlinear PDEs through their travelling wave reductions are considered. The ...Kudryashov function, R, satisfying a first-order second degree ODE has several features which significantly assist symbolic calculations, especially for highly dispersive nonlinear equations. A remarkable feature of the Kudryashov function R, is that its even order derivatives are polynomials in R only while its odd order derivatives turn out to be polynomials in R and R
z
. The procedure has been illustrated by means of the Schrödinger-Hirota equation, a quartic NLS equation and the fifth-order Kawahara equation as examples. A comparison with the Rayleigh-Ritz variational approach has also been considered for the purposes of illustration. The results obtained here are novel and span the family of solutions for such kind of equations.
We consider applications of a comparison method for obtaining some exact solutions of nonlinear partial differential equations (PDEs) through their traveling wave reductions. The method, proposed by ...N. A. Kudryashov, 39(18), 5733–5742, Applied Mathematical Modelling, is extended to encompass not only solutions expressible in terms of the logistic function but also to the
tanh$$ \tanh $$‐class of functions in a unified manner. The standard set of second‐order ordinary differential equations (ODEs) admitting the logistic and
tanh$$ \tanh $$ functions as solutions is derived and extensions to the third‐order case are enunciated. A number of examples are included to illustrate the method.
A novel class of traveling wave solutions for the Hirota–Schrödinger (HS) equation and the nonlinear Schrödinger equation (NLSE) with quadratic–cubic nonlinearity (QCN) has been obtained using ...conformable fractional space and time derivatives. The obtained solutions show interesting dispersive corrections to the propagating waves. Different fractional powers show phase shifting, singularity and a flattening of the propagating pulse. The bright one-soliton and singular soliton solutions for the NLSE with QCN have also been discussed. The present findings are likely to have significant relevance in the propagation of optical pulses in a highly nonlinear dispersive media.
Detection of the liquefied natural gas (LNG) leakage attracts increasing attention for preventing environments and governments from severe pollution and economic loss. Existing frameworks take ...advantage of stationary surveillance thermal cameras to detect the LNG leakage, which comprises background subtraction and leakage classification. However, these methods are limited in rural areas due to the lack of sensitivity and accuracy. In this article, a generalized framework, i.e., tensor-based leakage detection (TBLD), is proposed to detect LNG leakage in the rural area from surveillance thermal cameras. First, the proposed TBLD takes advantage of tensor factorization to fuse thermal image and corresponding gradient maps for improving sensitivity. Additionally, a finite-state-machine is designed to maintain leakage foreground along with the video streaming. The experiments demonstrate the robust performance of TBLD in the background subtraction stage. Second, multiple classification techniques are explored in the leakage classification stage. The results suggest that the TBLD can accurately detect the LNG leakage by applying 50 layers of residual networks (ResNet50). Finally, compared with contemporary frameworks, the TBLD has consistently improved performance concerning the different distances of LNG leakage. The experimental results demonstrate the effectiveness of the proposed TBLD, which also shows the great potential of TBLD in future industrial applications.
Medium chain triglycerides (MCT) enhance thermogenesis and may reduce food intake relative to long chain triglycerides (LCT). The goal of this study was to establish the effects of MCT on appetite ...and food intake and determine whether differences were due to differences in hormone concentrations.
Two randomized, crossover studies were conducted in which overweight men consumed 20 g of MCT or corn oil (LCT) at breakfast. Blood samples were obtained over 3 h. In Study 1 (n=10), an ad lib lunch was served after 3 h. In Study 2 (n=7), a preload containing 10 g of test oil was given at 3 h and lunch was served 1 h later. Linear mixed model analyses were performed to determine the effects of MCT and LCT oil on change in hormones and metabolites from fasting, adjusting for body weight. Correlations were computed between differences in hormones just before the test meals and differences in intakes after the two oils for Study 1 only.
Food intake at the lunch test meal after the MCT preload (Study 2) was (mean±s.e.m.) 532±389 kcal vs 804±486 kcal after LCT (P<0.05). MCT consumption resulted in a lower rise in triglycerides (P=0.014) and glucose (P=0.066) and a higher rise in peptide YY (PYY, P=0.017) and leptin (P=0.036) compared with LCT (combined data). Correlations between differences in hormone levels (glucagon-like peptide (GLP-1), PYY) and differences in food intake were in the opposite direction to expectations.
MCT consumption reduced food intake acutely but this does not seem to be mediated by changes in GLP-1, PYY and insulin.
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