1,047 research outputs found
Comparison of Multi-Criteria Decision Making Methods for Multi Optimization of GTAC Process Parameters
A great deal of investigation on gas tungsten arc cladding (GTAC) is focused on the study of enhancements in the microstructure, mechanical and tribological features of the cladding. The selection of right process parameters is a critical issue for the researchers. Decision makers in the industries must analyze a wide variety of parameters based on a set of contradictory criteria. Several multi-criteria decision-making (MCDM) techniques are now available to add values in selection of these parameters. The application of the TOPSIS and MOORA techniques to identify the best configuration of processing parameters in the gas tungsten arc cladding (GTAC) process is investigated in this work. The best processing parameters set for the multiple performance attributes should be welding current: 70 amp, speed: 240, argon flow: 13 and standoff distance 3.5 (TOPSIS-PCA) and welding current: 50, speed: 300, argon flow: 13 and standoff distance 3.5 (MOORA-PCA).A comparison of MOORA-PCA and TOPSIS-PCA demonstrates the superiority of TOPSIS over MOORA technique. The prediction accuracy of the TOPSIS-PCA hybrid approach model is found better than MOORA-PCA technique
Anomalous Raman scattering from phonons and electrons of superconducting FeSe
We report interesting anomalies in the temperature dependent Raman spectra of
FeSe measured from 3K to 300K in the spectral range from 60 to 1800
cm and determine their origin using complementary first-principles
density functional calculations. A phonon mode near 100 cm exhibits a
sharp increase by 5% in frequency below a temperature T ( 100
K) attributed to strong spin-phonon coupling and onset of short-range
antiferromagnetic order. In addition, two high frequency modes are observed at
1350 cm and 1600 cm, attributed to electronic Raman scattering
from ()to / -orbitals of Fe.Comment: 19 pages, 4 figures, 1 tabl
Breast Cancer Treatment Relying on Herbal Bioactive Components
Use of herbs and plants in cooking and medicinal dates back thousands of years. In this overview, we look at the many plant species that still have immune-boosting and cancer-fighting properties. Carotenoids, flavonoids, ligands, polyphenolics, terpenoids, sulphides, lignans, and plant sterols are only some of the many active phytochemicals found in different types of herbs. There are a number of mechanisms through which these phytochemicals exert their effects. They either prevent cell division or stimulate the synthesis of a protective enzyme such as glutathione transferase. The cancer-fighting and cholesterol-lowering effects of mevalonate are counteracted by the volatile oils and plant extracts from various herbs and plants
Ultrafast electron diffraction instrument for gas and condensed matter samples
We report the modification of a gas phase ultrafast electron diffraction (UED) instrument that enables experiments with both gas and condensed matter targets, where a time-resolved experiment with sub-picosecond resolution is demonstrated with solid state samples. The instrument relies on a hybrid DC-RF acceleration structure to deliver femtosecond electron pulses on the target, which is synchronized with femtosecond laser pulses. The laser pulses and electron pulses are used to excite the sample and to probe the structural dynamics, respectively. The new system is added with capabilities to perform transmission UED on thin solid samples. It allows for cooling samples to cryogenic temperatures and to carry out time-resolved measurements. We tested the cooling capability by recording diffraction patterns of temperature dependent charge density waves in 1T-TaS2. The time-resolved capability is experimentally verified by capturing the dynamics in photoexcited single-crystal gold
Valorisation of black carrot pomace: microwave assisted extraction of bioactive phytoceuticals and antioxidant activity using Box–Behnken design
The present study compares three methods viz.
microwave assisted extraction (MAE), ultrasonic-assisted
extraction (UAE) and conventional solvent extraction
(CSE) for extraction of phenolic compounds from black
carrot pomace (BCP). BCP is the major by-product generated
during processing and poses big disposal problem.
Box–Behnken design using response surface methodology
was employed to investigate and optimize the MAE of
phenolics, antioxidant activity and colour density from
BCP. The conditions for maximum recovery of polyphenolics
were: microwave power (348.07 W), extraction time
(9.8 min), solvent–solid ratio (19.3 mL/g) and ethanol
concentration (19.8%). Under these conditions, the extract
contained total phenolic content of 264.9 ± 10.02 mg
gallic acid equivalents (GAE)/100 mL, antioxidant capacity (AOC) of 13.14 ± 1.05 lmol Trolox equivalents
(TE)/mL and colour density of 68.63 ± 5.40 units. The
total anthocyanin content at optimized condition was
753.40 ± 31.6 mg/L with low % polymeric colour of
7.40 ± 0.42. At optimized conditions, MAE yielded higher
colour density (68.63 ± 5.40), polyphenolic content
(264.9 ± 10.025 mg GAE/100 mL) and AOC
(13.14 ± 1.05 lmol TE/mL) in a short time as compared
to UAE and CSE. Overall results clearly indicate that MAE
is the best suited method for extraction in comparison to
UAE and CSE. The phenolic rich extract can be used as an
effective functional ingredient in foods
Temperature-dependent Raman study of CeFeAsO0.9F0.1 Superconductor: Crystal field excitations, phonons and their coupling
We report temperature-dependent Raman spectra of CeFeAsO0.9F0.1 from 4 K to
300 K in spectral range of 60 to 1800 cm-1 and interpret them using estimates
of phonon frequencies obtained from first-principles density functional
calculations. We find evidence for a strong coupling between the phonons and
crystal field excitations; in particular Ce3+ crystal field excitation at 432
cm-1 couples strongly with Eg oxygen vibration at 389 cm-1 . Below the
superconducting transition temperature, the phonon mode near 280 cm-1 shows
softening, signaling its coupling with the superconducting gap. The ratio of
the superconducting gap to Tc thus estimated to be ~ 10 suggests CeFeAsO0.9F0.1
as a strong coupling superconductor. In addition, two high frequency modes
observed at 1342 cm-1 and 1600 cm-
Bulk Viscous LRS Biachi-I Universe with variable and decaying
The present study deals with spatially homogeneous and totally anisotropic
locally rotationally symmetric (LRS) Bianchi type I cosmological model with
variable and in presence of imperfect fluid. To get the
deterministic model of Universe, we assume that the expansion in the
model is proportional to shear . This condition leads to , where ,\; are metric potential. The cosmological constant
is found to be decreasing function of time and it approaches a small
positive value at late time which is supported by recent Supernovae Ia (SN Ia)
observations. Also it is evident that the distance modulus curve of derived
model matches with observations perfectly.Comment: 11 pages, 4 figures and 1 table, Accepted for publication in
Astrophysics and Space Scienc
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