We present the result of an experiment to measure the electric dipole moment (EDM) of the neutron at the Paul Scherrer Institute using Ramsey's method of separated oscillating magnetic fields with ...ultracold neutrons. Our measurement stands in the long history of EDM experiments probing physics violating time-reversal invariance. The salient features of this experiment were the use of a ^{199}Hg comagnetometer and an array of optically pumped cesium vapor magnetometers to cancel and correct for magnetic-field changes. The statistical analysis was performed on blinded datasets by two separate groups, while the estimation of systematic effects profited from an unprecedented knowledge of the magnetic field. The measured value of the neutron EDM is d_{n}=(0.0±1.1_{stat}±0.2_{sys})×10^{-26} e.cm.
In the present investigation, we have reported the fabrication of a low-cost, magnetically separable, solar light active NiFe2–x Nd x O4 photocatalyst with different neodymium contents. The ...synthesized photocatalyst samples were characterized by a combination of various physicochemical techniques such as PXRD, SEM, EDS, FTIR, and UV–vis spectroscopy. It was observed that Nd substitution can greatly enhance absorption in the whole visible region. With an increase in Nd concentration, NiFe2–x Nd x O4 samples show a red shift in absorption. Interestingly, Nd substitution into nickel ferrite results in a dramatic conversion of the inert NiFe2O4 into a highly solar light active photocatalyst for the degradation of organic pollutants and also shows excellent recyclability and durability properties. The significant enhancement in photoactivity under solar light irradiation can be ascribed to the reduction of the nickel ferrite band gap by Nd3+ substitution. Therefore, these unusual properties of NiFe2–x Nd x O4 encourage us to extend photocatalytic degradation to another few organic pollutants. This new photocatalyst system, NiFe2–x Nd x O4, can have other potential environmental and energy applications that only need visible light as energy input.
•A novel multi-physics computational framework for L-DED process is proposed.•Particle-scale thermofluidic model is integrated with Cellular Automata approach.•Realistic Inconel-625 particle stream ...predicted by DEM modelling is utilized.•Results reveal highly oscillatory and chaotic melt flow due to impinging particles.•Predicted melt pool, temperature, and grain structure compare well with experiments.
High speed imaging of molten pool free-surface hydrodynamics in laser-assisted directed energy deposition process clearly revealed a highly oscillatory and dynamic melt flow due to impinging powder particles. Surprisingly, most of the reported computational work exclude the injection of powder particles and rather adopt a homogeneous mass and energy addition approach, and therefore provides less accurate predictions. In this work, we develop a coupled multi-physics particle-scale approach utilizing the discrete element method for particle trajectory prediction, the computational fluid dynamics for free-surface thermo-fluidic modelling and the cellular automata method for grain growth evolution. In the model, the governing physical phenomena, such as laser-powder interaction, in-flight particle heating, phase change (melting, vaporization and solidification), free-surface evolution, molten pool hydrodynamics and impinging particles-melt interaction have been considered. Experiments for the deposition of Inconel-625 on an Inconel-625 substrate are carried out, and the model predictions are validated with the experimental measurements. For the first time, the predicted thermo-fluidic simulation results reveal highly oscillatory, chaotic and random melt flow attributed to the impinging powder particles. During the deposition, it is found that the role of the Marangoni convection is less significant as compared to the momentum imparted by the impinging powder particles in the melt pool. Using the simulated thermal undercooling data, cellular automata-based grain growth simulation predicts elongated columnar dendrites in the melt pool that grows epitaxially from the melt pool interface and stretches towards the centre. Using the Kurz-Fisher model, the effect of local thermodynamic solidification conditions on the size of dendritic microstructure is also described. The predicted melt pool geometry, temperature field and grain structure compare well with the experimental measurements.
Moringa oleifera Lam. leaves are rich source of carotenoids (provitamin A) and α-tocopherol (vitamin E), and there is a scope for their further enhancement, through elicitor mediation, thereby a ...great potential for addressing these vitamins deficiency. In the present study, we report the efficacy of foliar administration of biotic elicitors, carboxy-methyl chitosan and chitosan, and signaling molecules, methyl jasmonate (MJ) and salicylic acid (SA) for enhancement of major carotenoids and α-tocopherol. Highest α-tocopherol content of 49.7 mg/100 g FW was recorded upon foliar application of 0.1 mM SA after 24 h of treatment, which represented a 187.5 % increase in comparison to the untreated control. Similarly, a maximum of 52.6 mg/100 g FW lutein, and 21.8 mg/100 g FW β-carotene content were observed in leaves after 24 h of treatment with MJ, which represented a 54.0 and 20.3 % increase in comparison to the untreated control, respectively. Among the major genes of carotenoid biosynthetic pathway, the expression of lycopene β-cyclase (LCY-β) was maximum influenced after treatment with elicitors and signaling molecules, compared to phytoene synthase and phytoene desaturase, suggesting the LCY-β-mediated enhancement in the production of β-carotene in elicitor treated M. oleifera leaves. Enhanced production of α-tocopherol under respective elicitor treatment was further supported by 2.0–2.7 fold up-regulation of γ-tocopherol methyl transferase, compared to untreated control. This is the first report on elicitor-mediated enhanced production of tocopherol and carotenoids in foliage of economically important food plant.
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•Synthesis of biologically active Cu(II) mixed ligand metal complexes and their characterization.•All the complexes exhibited efficient DNA groove-binding propensity.•The complexes ...were able to cleave pUC19 DNA effectively via singlet oxygen generation.•Screening of newly synthesized complexes as an antibacterial photosensitizer.
Cu(II) complexes Cu(mqt)(B)H2OClO4(1–3) of 2-thiol 4-methylquinoline and phenanthroline bases (B), viz 1,10-phenanthroline (phen in 1), Dipyrido3,2-d:2′,3′-fquinoxaline (dpq in 2) and Dipyrido3,2-a:2′,3′-cphenazine (dppz in 3) have been prepared and characterized by elemental analysis, IR, UV–Vis, magnetic moment values, EPR spectra and conductivity measurements. The spectral data reveal that all the complexes exhibit square-pyramidal geometry. The DNA-binding behaviors of the three complexes were investigated by absorption spectra, viscosity measurements and thermal denaturation studies. The DNA binding constants for complexes (1), (2) and (3) were determined to 2.2×103, 1.3×104 and 8.6×104M−1 respectively. The experimental results suggest that these complexes interact with DNA through groove-binding mode. The photo induced cleavage studies shows that the complexes possess photonuclease property against pUC19 DNA under UV–Visible irradiation via a mechanistic pathway involving formation of singlet oxygen as the reactive species. Antimicrobial photodynamic therapy was studied using photodynamic antimicrobial chemotherapy (PACT) assay against Escherichiacoli and all complexes exhibited significant reduction in bacterial growth on photoirradiation.
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This study presents a comprehensive exploration into the synthesis and multifaceted characterization of strontium titanate (ST) nanopowder via the solution combustion method. The ...investigation delves into the photoluminescent properties, electrochemical behaviors assessed through potentiodynamic polarization (PDP) and electrochemical impedance spectroscopy (EIS), as well as antibacterial characteristics of the synthesized nanoproduct. Through meticulous analysis involving powder X-ray diffraction (PXRD), Field emission scanning electron microscopy (FESEM), Transmission electron microscopy (TEM), Fourier-transform infrared spectroscopy (FT-IR), and UV–visible spectroscopy (UV–vis), ST nanoparticles revealed intriguing features. PXRD unveiled a cubic crystal structure with a crystallite size of ∼ 11 nm, showcasing a crystallinity of 89.23. FESEM, UV–visible spectroscopy, and FT-IR studies uncovered irregularities in size, band gap properties, and the formation of M−O bonds within ST, with an Eg value of ∼ 3.0 eV. Photoluminescence investigations highlighted oxygen deficiencies within the ST material. Furthermore, corrosion inhibition efficiency was evaluated, demonstrating a maximum of 81.9 % at a concentration of 400 ppm, while antibacterial studies exhibited promising results against both Gram-positive (Bacillus subtilis) and Gram-negative (Escherichia coli) bacteria, with zone of inhibitions (ZOI) measuring 8.00 ± 0.250 mm and 9.00 ± 0.000 mm, respectively. These findings collectively underscore the diverse potential applications of ST nanoparticles and offer valuable insights into their structural, optical, electrochemical, and antimicrobial properties.
Background: Science of well-being is getting focused across all walks of life from health care to organizational behavior. Indian psychological principles of Tri-Guna offer a universal theoretical ...framework to understand the behavioral aspects of emotions and well-being, whereas affective neurosciences have explored neural circuits underlying few universal emotional styles. Both Tri-Guna and emotional styles are dynamic and vulnerable for modifications with training. Hence, establishing a relation between Tri-Guna and emotional style offers a novel insight to explore neural basis of Tri-Guna and its application in health and behavioral sciences. Aims: To establish the correlation between Tri-Guna and emotional styles in healthy adult subjects. Materials and Methods: Healthy adults (n = 121, 18-21 years) of both genders were individually administered with questionnaires to assess Tri-Guna (Vedic personality inventory) and emotional style (emotional style questionnaire). The relationship between Tri Guna (Sattva, Rajas and Tamas) and Six dimensions of emotional styles (attention, self awareness, outlook, resilience, social intuition and sensitivity to context) were assessed using Pearson's correlation coefficient. Results: All the emotional styles showed a positive correlation with Sattva and negative with Rajas and Tamas, except resilience. Resilience showed a negative correlation with Sattva and positive with Rajas and Tamas. Further, between Rajas and Tamas, emotional styles showed a stronger correlation with Tamas. Conclusions: Sattva guna showed an association with emotional styles that favors to develop a positive emotional pattern. Having fairly understood neural circuitry of emotional styles, this first preliminary correlation data will provide a theoretical framework to explore neural circuitry involved in understanding emotional aspects of Tri-Guna.
•Synthesis of ZnS/MnS/ZnS nanocomposites by chemical co-precipitation.•Characterized by the spectral techniques.•Study on their optical properties showed blue shift when compared to ...bulk.•Photoluminescence was tuned in red region by varying the thickness of MnS layer.
Uncoated ZnS, MnS and ZnS/MnS/ZnS nanocomposites were successfully synthesized by chemical co-precipitation method in air atmosphere by varying the thicknesses of MnS layer. Characterization techniques such as X-ray diffraction (XRD), high resolution transmission electron microscopy (HRTEM), UV–visible absorption and photoluminescence (PL) spectroscopy were used to characterize the novel ZnS/MnS/ZnS nanocomposites. The obtained particles were highly crystalline and monodispersed with an average particles size of 4.5–6.5nm. The room temperature photoluminescence (PL) study of ZnS/MnS/ZnS nanocomposites showed an enhanced intensity with different concentration of manganese acetate. The presences of MnS layer in the nanocomposite have tuned the PL emission in the IR region. Addition of manganese acetate (0.1–0.4M) in the nanocomposite showed a distinct PL emission peak centered at 740nm i.e. in the red region with significant red shift. The PL emission of ZnS and MnS were tuned in the nonvisible IR region. It is shown that the variation in thickness of MnS layer leads to an enhanced photoluminescence intensity/efficiency of ZnS/MnS/ZnS nanocomposites.
•Synthesis of PVA capped Mn2+ doped ZnS nanoparticles by chemical precipitation method in air atmosphere.•Characterized by the spectral techniques.•Study on their optical properties.•Calculation of ...particle size by different techniques.•Investigation of the increased luminescence characteristics (UV to IR region) of Mn2+ doped ZnS ions at room temperature and the origin of the luminescence observed.
This paper reports the enhanced photoluminescence (PL) property of polyvinyl alcohol (PVA) capped Mn2+ doped ZnS nanocrystals prepared by chemical precipitation method. The surface-modified Mn2+ doped ZnS nanocrystals resulted in the multi-color property. The morphology and crystallite size were characterized by field emission scanning electron microscopy (FESEM), high-resolution transmission electron microscopy (HRTEM) and X-ray diffraction (XRD) techniques. The crystallite size was estimated to be 5nm from HRTEM and calculated as 2–4nm from peak broadening of the X-ray diffraction (XRD) pattern with cubic zincblende structure. Increase in the band gap with decrease in the crystallite size was observed from the UV–visible absorption spectrum, which confirms the quantum confinement effect. The room temperature photoluminescence (PL) emission measurements revealed the presence of blue (427nm) and near IR reddish–orange (752nm) emission bands in addition to the typical yellow–orange (585nm) bands in all the Mn2+ doped samples, which were attributed due to transition within the 3ds configuration of Mn2+ ions incorporation in ZnS host under UV excitation at 320nm. As far as we know, the reddish–orange bands at 752nm near IR region along with the blue and yellow–orange colored PL are reported for the first time. In this way, the PL color from these ZnS nanocrystals can be tuned from UV to near infrared region (IR). The synthesized ZnS:Mn NPs can be further functionalized for using them as biolabels.
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