Metal sulfides are of great interest for future electrode materials in supercapacitor and solar cell applications owing to their superior electrochemical activity and excellent electrical ...conductivity. With this scope, a binary transition metal sulfide (CoS) is prepared via one-step hydrothermal synthesis. Hexagonal phase of CoS with space group of P6
/mmc(194) is confirmed by XRD analysis. Additional cubic Co
S
phase in the prepared sample originates the mixed valence state of Co (Co
and Co
) is affirmed from XPS analysis. Morphological features are visualized using HRSEM images that shows nanoflower shaped star-anise structure. Employing the prepared CoS as active electrode material, interfacial charge transport kinetics is examined by EIS-Nyquist plot. The supercapacitive performances are tested in two and three-electrode system which exhibited respective specific capacitances of 57 F/g and 348 F/g for 1 A/g. Further, the fabricated asymmetric CoS//AC supercapacitor device delivers an appreciable energy density of 15.58 Wh/kg and power density of 700.12 W/kg with excellent cyclic stability of 97.9% and Coulombic efficiency of 95% over 2000 charge-discharge cycles. In addition, dye-sensitized solar cells are fabricated with CoS counter electrode and the obtained power conversion efficiency of 5.7% is comparable with standard platinum based counter electrode (6.45%). Curie-Weiss plot confirms the transition of paramagnetic nature into ferrimagnetic behavior at 85 K and Pauli-paramagnetic nature at 20 K respectively. Temperature dependent resistivity plot affirms the metallic nature of CoS sample till 20 K and transition to semiconducting nature occurs at <20 K owing to Peierl's transition effect.
•We study the ZnO and Carbon coated ZnO nanoparticles for supercapacitor electrode materials.•Initially pure ZnO and ZnO/C nanoparticles were measured for three electrode configuration.•This result ...indicates that carbon coated ZnO nanoparticles is the suitable candidate for symmetric supercapacitor device fabrication.•Based on these three electrode results we fabricated on symmetric device.•The symmetric device yields a specific cell capacitance of 92 F g−1 at the specific current of 2.5 A g−1.
With the eco friendly green chemistry technique in mind, sucrose has been used in this study as the capping agent to synthesize ZnO/C nanocomposite adapting sol-gel method. The presence of carbon in the prepared ZnO/C was confirmed through EDAX. Electrochemical investigations of ZnO/C electrode were carried out using cyclic voltammetry, galvanostatic charge-discharge, and electrochemical impedance spectroscopy. The ZnO/C electrode exhibits a maximum specific capacitance of 820 F g−1 at a constant specific current of 1 A g−1. The symmetric aqueous supercapacitor device exhibits the specific cell capacitance of 92 F g−1 at the specific current of 2.5 A g−1. The aqueous symmetric supercapacitor device achieved an energy density of 32.61 Wh kg−1 and the power density of approximately 1 kW kg−1 at a discharge current of 1.0 A g−1. It has been found that the cells have an excellent electrochemical reversibility (92% after 400 continuous cycles) and capacitive characteristics in 1 M Na2SO4 electrolyte.
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•Magnesium incorporated hydroxyapatite was synthesized by using microwave-assisted wet chemical method.•The spectrophotometer method was used to perform the hemolytic activity of the ...samples.•The chemical bonding of the samples was confirmed by the FTIR spectrum.•The HR-TEM confirms the spherical morphology of the synthesized samples.•The in vitro antibacterial activity of the samples was studied.•The in vitro anti-inflammatory activity against standard drug diclofenac sodium for the samples were studied.•The samples were non-hemolytic according to the ASTM F756-00 (American Society for Testing and Materials Designation).
In this work, we have investigated the antibacterial and hemolytic efficacy of hydroxyapatite (HA) and Magnesium (Mg) incorporated hydroxyapatite (MHA), where the composite was synthesized by a rapid and cost-effective microwave-assisted wet chemical method. The synthesized MHA composite was characterized by using X-ray diffraction (XRD), Fourier transform-infrared spectroscopy (FTIR), High-resolution transmission electron microscopy (HRTEM), in vitro antibacterial and anti-inflammatory activities. Also, the hemolytic activity of the sample was studied using the spectrophotometer technique. From the analysis, the XRD diffractogram confirms the presence of HA and MHA by the JCPDS card no: 09-0432. The chemical bonding confirmed the presence of Mg and HA in the nanocomposite and the HRTEM confirmed the spherical shape morphology of synthesized samples. The in vitro antibacterial activity of the nanocomposite was studied against the gram-positive bacteria Staphylococcus aureus and gram-negative bacteria Escherichia coli. Also, the in vitro anti-inflammatory activity of the sample was studied against the standard drug Diclofenac sodium and found to be compatible with the standard values. Further, the samples are investigated to be non-hemolytic according to the ASTM F756-00 (American Society for Testing and Materials Designation). Based on the studies, the prepared Mg-HA nanocomposite can be potential for the biomedical applications of dental, orthopaedic, and stem cell research.
A vertex x in a connected graph G is said to resolve a pair {u,v} of vertices of G if the distance from u to x is not equal to the distance from v to x. A set S of vertices of G is a resolving set ...for G if every pair of vertices is resolved by some vertex of S. The smallest cardinality of a resolving set for G, denoted by dim(G), is called the metric dimension of G. For the pair {u,v} of vertices of G the collection of all vertices which resolve the pair {u,v} is denoted by R{u,v} and is called the resolving neighbourhood of the pair {u,v}. A real valued function g:V(G)→0,1 is a resolving function of G if g(R{u,v})≥1 for any two distinct vertices u,v∈V(G). The fractional metric dimension of G is defined as dimf(G)=min{|g|:g is a minimal resolving function of G}, where |g|=∑v∈Vg(v). In this paper we study this parameter.
► First paper presenting basic results on fractional metric dimension. ► Upper and lower fractional metric independence number—new concepts introduced in this paper. ► Fractional metric dimension of standard graphs. ► Fundamental results on graphs with fractional metric dimension n2 where n is the order of the graph.
In this study, we used the solution growth approach to successfully synthesis tricine potassium nitrate (TPN) single crystals. The phases of TPN crystals were determined by the powder X-ray ...diffraction (PXRD) method. The functional groups present in the crystals generated were examined using Fourier transform infrared (FT-IR) analysis. A UV-VIS-NIR examination was done between 200 and 800 nm to gauge optical transparency. The photoluminescence (PL) spectrum of TPN crystal was captured. Investigating the mechanical properties of the crystal was done using a vickers hardness tester.The thermal behaviours of the crystals formed were examined using thermal gravimetric/differential thermal analysis. A field emission scanning electron microscope was used to determine the crystal's surface shape. The TPN crystal’s properties were investigated using wet etching procedures. The Kurtz–Perry technique was used to investigate the effectiveness of the developed crystals’ second harmonic generation (SHG). The antibacterial activity of TPN grown crystal against various standard bacterial strains. The results show that produced TPN single crystals can be used for nonlinear optical applications and that they can also be tested for antibacterial properties to determine the material’s potential applications.
•Study reported intensification of kokum oil yield (62.43 %) via ultrasonic extraction.•Potential of kokum oil via ultrasonic extraction is explored as feedstock for biodiesel.•Kokum oil recovery is ...intensified by optimizing extraction parameters using RSM.•At 20 min, proposed strategy yields 16.43 % more kokum oil than Soxhlet extraction.•Soxhlet extraction needed 5.6 times the energy than ultrasonic extraction.
This novel study reports the intensification of oil yield from kokum seeds through an energy-efficient oil extraction using the ultrasonication method. To maximize the kokum oil recovery, the ultrasonication process parameters were optimized using response surface methodology based on the Box-Behnken design. The effects of sonication time (St; 10–30 min), extraction temperature (ET; 35–45 °C), ultrasonic power (Up; 80–120 W), and solvent-kokum seed powder (sksp) ratio (30–50 mL/g) on the kokum oil yield were examined. The optimal extraction conditions were St=20 min; ET= 40 °C; Up=100 W; and sksp ratio=40 mL/g yielding 62.43 % of kokum oil. The Soxhlet extraction method yields 46 % kokum oil at an extraction temperature of 60 °C after 24 h as reported in the literature. In contrast, the ultrasonic extraction produced a 16.43 % higher kokum oil yield (i.e., 62.43 %) than Soxhlet extraction even at a reduced St=20 min and ET= 40 °C. Therefore, in recovering the kokum seed oil, the ultrasonic extraction was more efficient than the Soxhlet extraction method and also this research lays the groundwork and emphasizes the necessity of investigating kokum oil's possible use as a feedstock for the manufacturing of food-grade lubricants.
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Using an optical fiber to both excite the nitrogen-vacancy (NV) center in diamond and collect its fluorescence is essential to build NV-based endoscope-type sensor. Such endoscope-type sensor can ...reach inaccessible fields for traditional NV-based sensors built by bulky optical components and extend the application areas. Since single NV's fluorescence is weak and can easily be buried in fluorescence from optical fiber core's oxide defects excited by the green laser, fixing a micrometer size diamond containing high-density NVs rather than a nanodiamond containing single NV or several NVs on the apex of an optical fiber to build an endoscope-type sensor is more implementable. Unfortunately, due to small numerical aperture (NA), most of the optical fibers have a low fluorescence collection efficiency, which limits the sensitivity and spatial resolution of the NV-based endoscope-type sensor. Here, using a tapered optical fiber (TOF) tip, we significantly improve the efficiency of the laser excitation and fluorescence collection of the NV ensembles in diamond. This could potentially enhance the sensitivity and spatial resolution of the NV-based endoscope-type sensor. Numerical calculations show that the TOF tip delivers a high NA and has a high NV excitation and fluorescence collection efficiency. Experiments demonstrate that such TOF tip can obtain up to over 7-fold excitation efficiency and over 15-fold fluorescence collection efficiency of that from a flat-ended fiber (non-TOF) tip.
We investigate the baroentropy change on manganites (ΔSbM and ΔSbM- ρ) using modified form of Maxwell’s equation through magnetization and magnetization-resistivity measurements. Hence, we choose two ...Mn-site doped pervoskite manganites Pr0.6Ca0.4Mn0.96Co0.04O3 and Pr0.6Ca0.4Mn0.96Cr0.04O3 due to strong correlation between magnetic and electrical properties. The two external perturbations such as magnetic field and hydrostatic pressure have a similar influence on magnetic and transport properties of manganite systems due to its strong coupling between spin, charge, and orbital degrees of freedom. Baroentropy change, similar to magneto entropy change, could be estimated by replacing magnetic field in Maxwell’s equation by pressure in perovskite manganites. The estimated values of ΔSbM and ΔSbM-ρ using proposed equations well agree with each other, justifying the use of these equations. As these values are deduced from pressure dependent magnetization and resistivity measurements, this method of baroentropy change estimation is very useful as well as reliable in order to select application-oriented systems from the manganites family.
•H and P have a similar influence on magnetic and transport properties of manganites.•Two modified forms of Maxwell’s equation are proposed to estimate baroentropy changes.•ΔSbM and ΔSbM-ρ values completely rely on magnetization and resistivity of a system.•P and H increase the baroentropy change of selected Co and Cr doped systems.•These are reliable for manganites in which analogue in magnetic and transport properties.
We investigated NiF2 as an energy storage material in asymmetric supercapacitor together with activated carbon (AC) as the counter electrode. Cyclic voltammetry and galvanostatic charge-discharge ...profile are carried out to investigate the oxidation-reduction process and capacitive behavior of the NiF2 sample. The interfacial electron transport properties of the sample are also explored using Nyquist plots in two and three electrodes configurations of electrochemical impedance spectroscopy. A very high specific capacitance of 751 F/g is achieved at 1 A/g current density in three electrode system. Further, the asymmetric supercapacitor device based on NiF2//AC structure reveals high capacitance of 175 F/g at 1 A/g in the high window potential of 1.8 V. The fabricated device retained 93% of its initial capacitance after 1000 cycles at 3 A/g current density affirms high electrochemical stability of the device. Ragone plot depicts high energy density of 79.65 Wh/kg with power density of 1727.35 W/kg for 1.8 V window potential at 1 A/g current density. High electrochemical stability of NiF2 sample endures the tetragonal phase even after electrochemical measurement which can be more useful in recycling the electrode material for future recycled supercapacitor devices.
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•Pristine NiF2 was employed for the fabrication of asymmetric supercapacitor device.•NiF2//AC device presented high Cs of 175 F/g@1 A/g with high window potential of 1.8 V.•Ragone plot depicts high ED = 79.65 Wh/kg and PD = 1727.35 W/kg for 1.8 V@1A/g.•After electrochemical measurement, NiF2 can be recyclable for further device fabrication.
Effective crop farming depends on wise selection of crops. It is an essential factor that has to be fulfilled before beginning an agricultural endeavor. Conventionally, the crop that has to be grown ...is selected without considering the location and cultivated site’s characteristics by only considering its profit and demand on the market. Choosing the best crop for the circumstances can minimize the need for additional fertilizer and water for irrigation and help in attaining enhanced crop yield. Therefore, choosing the right crop is crucial for a successful agricultural situation. Thus, a novel crop recommendation model by considering the soil and geographical conditions is developed to aid the farmers in choosing the appropriate crop for the right condition so that the overall production can be enhanced to increase the overall profit and decrease the losses faced by the farmers. At first, a certain geographical area is selected, and the ideal parameters for growing a particular plant are gathered from the standard database. Next, the deep optimal features are extracted using a Serial Cascaded network in which an autoencoder is cascaded with a “Dimensional Convolutional Neural Network (1DCNN)” from the gathered data. The obtained deep features are optimally selected using the developed Modified Movement Territory of Fire Hawk Optimizer (MMTFHO). These optimally selected features are given to the Adaptive and Attention-based Hybrid Network (AAHNet) in which “Gated Recurrent Unit (GRU), and Long Short Term Memory (LSTM)” are utilized for choosing the right crop for the provided geographical condition. The parameters in the AAHNet are optimized using the same enhanced MMTFHO algorithm for improving the precision of the appropriate crop selection process. The final prediction of crops for the given geographical condition is obtained from the AAHNet. The final or overall rating of the recommended approach regarding accuracy metrics is 96.73%.
•To design an effective crop recommendation system using Hybrid approaches.•To design an Adaptive and Attention-based Hybrid Network (AAHNet) model.•To promote an AAHNet model for enhancing the precision of crop selection.•To introduce a Modified Movement Territory of Fire Hawk Optimizer (MMTFHO).•To optimize the variables and select the optimal features using MMTFHO algorithm.
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