The present paper illustrates the influence of the top Ag and Te thin layer on the linear and nonlinear optical properties of Ag(Te)/As
50
Se
50
bilayer thin films. The As
50
Se
50
and Ag(Te)/As
50
...Se
50
bilayer thin films were prepared by thermal evaporation technique under high vacuum conditions. The X-ray diffraction study showed no structural changes, whereas the UV–Visible spectroscopy data showed the changes in optical properties due to top layer deposition. From the recorded optical transmission data, the optical parameters, such as absorption coefficient, extinction coefficient, optical bandgap, Tauc parameter, Urbach energy, linear refractive Index, oscillator energy, dispersion energy, high-frequency dielectric constant and carrier concentration, were evaluated. The transmittance decreased and the absorption coefficient increased along with the increase in extinction coefficient. The optical bandgap decreased due to the increase in defect states and the degree of disorder. The dispersion of the refractive index was analyzed by the single oscillator Wemple–Di Domenico model. The third-order nonlinear susceptibility (
χ
(3)
) and nonlinear refractive index (
n
2
) were calculated from the linear optical parameters using semi-empirical relations. The linear, nonlinear refractive index and (
χ
(3)
change was found to be more in Te/As
50
Se
50
film than that of Ag/As
50
Se
50
film as compared with the host As
50
Se
50
film. The surface morphology was investigated by field emission scanning electron microscopy. The tuning of optical properties by simple layer deposition on the host matrix can be used in various optoelectronic applications.
L-asparaginase has been widely accepted as a standard anticancer drug for acute lymphoblastic leukaemia (ALL). Presently in L-asparaginase biotherapeutic applications, the main focus is developing ...new L-asparaginase with minimal or without any glutaminase activity to reduce the associated adverse drug reactions. In this study,
Bacillus flexus
strain SS (NCBI GenBank Accession Number MN420983) was identified as a promising producer of L-asparaginase. L-asparaginase production was optimized by response surface methodology statistical bioprocess modelling, and enzyme yield of 25.08 IU/mL was reached at the bioreactor scale. The purification of L-asparaginase included ammonium sulfate precipitation, ion-exchange chromatography and size exclusion chromatography yielding 5.27-fold purification. The SDS-PAGE and CE-SDS revealed the monomeric L-asparaginase with molecular weight of 33 kDa. The purified enzyme was highly specific to substrate L-Asn and free from glutaminase activity. The anticancer activity of purified L-asparaginase was found specific against tumor cell lines SKBR3 (IC
50
= 0.8 µg/mL), WIL2-S (IC
50
= 16.2 µg/mL), and TF-1 (IC
50
= 47 µg/mL), but not against negative control HUVEC cells. Therefore, L-asparaginase from
B. flexus
SS with no glutaminase activity could be a potential new candidate for anticancer drug for ALL with reduced adverse effects.
Abstract
Fire-induced and stress-driven catastrophic failures in rock and concrete are commonly known as spalling (or rockburst in its severe form) that have jeopardised the safety of personnel, ...seriously damaged rock structures, and shut down operations for months or even permanently in certain circumstances. Particularly in Australia, spalling and rockburst in deep excavations results in a heavy toll on mine safety and have become a constraint to the economic viability of several Australian deep mines since the early 1950s. The prevailing industry approach is to treat such unwanted failures and associated microseismic events as a result of insufficient energy absorption by the spalling-prone rock/concrete at the post-peak stage. However, this approach does not allow efficient handling of heat- or stress-induced failures as it requires an in-depth understanding of their mechanics. Prediction of these events based on the available failure criteria does not help either due to the numerous criteria involved and the difficulty in determining their parameters at the excavation scale. A proper understanding of the fracture growth in such failures is needed to understand the behaviour of rock or concrete structures resulting in a sudden release of energy at deep excavations. This paper investigates the similarities and differences between heat-induced concrete spalling and stress-driven rockburst and further examines the effect(s) of material, geometrical, geological properties, and the applied deviatoric stresses on these failure modes.
In this paper, we have suggested an alternative approach to solve intuitionistic fuzzy multi objective linear fractional programming problems (IFMOLFPP). Here, the cost of the objective function, the ...resources and the technological coefficients are taken to be pentagonal intuitionistic fuzzy numbers. In the proposed method, we have transformed (IFMOLFPP) to intuitionistic fuzzy multi objective linear programming problem (IFMOLPP) and then the resultant (IFMOLPP) is converted into crisp multi objective linear programming problem (CMOLPP) under well defined accuracy function. We have established some theorems to show that the efficient solution of (CMOLPP) is also an efficient solution of (IFMOLPP) and (IFMOLFPP). Then by using Zimmermann’s technique under suitable non linear membership functions, we have reduced (CMOLPP) to a single objective LPP which can be easily solved by any LPP algorithm or software. We have illustrated the proposed approach by Numerical examples.
Thin films of SnS
1−
x
Se
x
with varying Se (
x
= 0, 0.1, 0.15, 0.2, 0.25) contents were deposited by the thermal evaporation method on glass substrates at room temperature. The crystalline nature of ...the films is verified using structural characterization techniques such as X-ray diffraction and Raman analysis. The crystallinity increased with Se concentration. The nanoflake-like structure with an increase in size and density upon Se addition is observed from the morphology study through field emission scanning electron microscopy. The energy-dispersive X-ray analysis confirmed the elemental % in different films. The transmittance data were recorded in the range of 900-1100 nm by UV-Vis spectroscopy and used to evaluate the linear/nonlinear optical properties. The transmission percentage decreased with the doping of Se in the SnS binary compound. The absorption and extinction coefficients were enhanced with Se content. The bandgap value decreased with the doping concentration. The optical energy gap is used to evaluate the static refractive index using Dimitrov and Sakka's relation. The value of the static refractive index increased with Se content, which further helped to enhance the nonlinear optical parameters. The nonlinear parameters such as the nonlinear refractive index and third-order nonlinear susceptibility increased with the Se concentration. The theoretically calculated physical parameters like the average heat of atomization decreased with Se content. Tuning of nonlinear and linear properties by varying the selenium doping content in SnS
1−
x
Se
x
films will be useful in many photonic and optoelectronic devices.
The effect of Se doping in SnS alloys which decreased the transmission and increase in crystallinity of the films with change in morphology. The optical bandgap decreased and there was a simultaneous increase in 3rd order non-linear susceptibility.
Slag generating from the basic oxygen furnace during steelmaking is one of the significant solid wastes that has not been recycled due to many physical, chemical, and structural properties. ...Phosphorous is one of the key yardsticks for recycling the slag as a Ca-rich flux into the iron making process. The recycling of the slag depends on the phosphorous limitation as well as other properties. In the present investigation, an effort is made to understand the phosphorous distribution in a slag generated from Indian operation and analyzed through different characterization techniques. It is found that phosphorous is well dispersed in all the different phases in the sample and present predominantly at an ultrafine size. It is further tried to analyze the phosphorous partition in the different slag phases through the magnetic separation. From the characterization, it can be concluded that it is difficult to partition phosphorous-rich fractions. Majority of the particles are varying with phosphorous concentration from 1.55 to 7.86% in ultrafine size dissemination.
Amorphous-crystalline phase transformation induced changes in linear and nonlinear optical properties of Te/As2Se3 bilayer thin films.
Display omitted
•Amorphous-crystalline phase transformation upon ...diffusion Te into As2Se3 thin film.•XRD pattern, and Raman spectra confirm phase transformation upon thermal annealing.•Optical bandgap and refractive index were obtained from spectroscopic data.•Non-linear optical parameters have increased with annealing.•Te/As2Se3 bilayer film useful for phase change material based optoelectronic devices.
The present work reports the amorphous-crystalline phase transformation by interdiffusion of Te into the As2Se3 matrix with annealing at various temperatures (100, 150, and 200 °C). Te/As2Se3 bilayer thin films were prepared by electron beam evaporation under high vacuum conditions. The amorphous nature of As2Se3 thin film was confirmed from the X-ray diffraction study. The presence of small peaks in Te/As2Se3 thin film indicates the As4Te4 (monoclinic) and As2Se3 (monoclinic) phases, confirming the amorphous to crystalline phase transformation upon Te interdiffusion and subsequent annealing. The impact of Te top layer deposition on the vibrational modes were also observed from the Raman spectroscopy. The formation of Te agglomerates is confirmed from the morphological analysis which disappeared with further annealing. Furthermore, the water contact angle measurements have provided insight into surface interaction mechanisms of these materials. The linear and nonlinear optical properties were changed upon interdiffusion of Te as observed from UV–Visible spectroscopy. The increase in Eu indicated an increase in disorder hence the decrease in the bandgap. The 3rd order nonlinear susceptibility (χ3) and nonlinear refractive index (n2) increased with annealing. The tuning of linear and nonlinear optical properties by annealing can be used in various optoelectronic applications. Specifically, the phase transformation behaviour of Te/As2Se3 bilayer thin films enables their utilization in phase-change material-based optoelectronic devices.
Correction for ‘In situ laser irradiation: the kinetics of the changes in the nonlinear/linear optical parameters of As50Se40Sb10 thin films for photonic applications’ by D. Sahoo et al., RSC Adv., ...2021, 11, 16015–16025, https://doi.org/10.1039/D1RA02368C.
First principles calculations have been performed using plane wave pseudopotential and full potential linearized augmented plane wave (FP-LAPW) methods to analyze structural, elastic and dynamic ...stability of UC under hydrostatic compression. Our calculations within pseudopotential method suggest that the rocksalt (B1) structure will transform to body centered orthorhombic (bco) structure at ∼21.5GPa. The FP-LAPW calculations put this transition at 23GPa. The transition pressures determined from our calculations though agree reasonably with the experimental value of 27GPa, the high pressure bco structure suggested by theory differs slightly from the experimentally reported pseudo bco phase. The elastic stability analysis of B1 phase suggests that the B1 to bco transition is driven by the failure of C44 modulus. This finding is further substantiated by the lattice dynamic calculations which demonstrate that the B1 phase becomes dynamically unstable around the transition pressure and the instability is of long wavelength nature.
In this paper, power quality transient data are compressed and stored for analysis and classification purposes. From the compressed data set, original data are reconstructed and then analyzed using a ...modified wavelet transform known as S-transform. Compression techniques using splines are performed through signal decomposition, thresholding of wavelet transform coefficients, and signal reconstruction. Finally, the authors present compression results using splines and examine the application of splines compression in power quality monitoring to mitigate against data-communication and data-storage problems. Since S-transform has better time frequency and localization property, power quality disturbances are detected and then classified in a superior way than the recently used wavelet transform.
PDF
