RP-HPTLC densitometric determination and validation of vanillin and related phenolic compounds in accelerated solvent extract of Vanilla planifolia*

A simple, fast and sensitive RP-HPTLC method is developed for simultaneous quantitative determination of vanillin and related phenolic compounds in ethanolic extracts of Vanilla planifolia pods. In addition to this, the applicability of accelerated solvent extraction (ASE) as an alternative to microwave-assisted extraction (MAE), ultrasound-assisted extraction (UAE) and Soxhlet extraction was also explored for the rapid extraction of phenolic compounds in vanilla pods. Good separation was achieved on aluminium plates precoated with silica gel RP-18 F(254S) in the mobile phase of methanol/water/isopropanol/acetic acid (30:65:2:3, by volume). The method showed good linearity, high precision and good recovery of compounds of interest. ASE showed good extraction efficiency in less time as compared to other techniques for all the phenolic compounds. The present method would be useful for analytical research and for routine analysis of vanilla extracts for their quality control.     

Hierarchical Nanoflower Arrays of Co9S8-Ni3S2 on Nickel Foam: A Highly Efficient Binder-Free Electrocatalyst for Overall Water Splitting

Hydrogen production is vital for meeting future energy demands and managing environmental sustainability. Electrolysis of water is considered as the suitable method for H₂ generation in a carbon-free pathway. Herein, the synthesis of highly efficient Co₉S₈-Ni₃S₂ based hierarchical nanoflower arrays on nickel foam (NF) is explored through the one-pot hydrothermal method (Co₉S₈-Ni₃S₂/NF) for overall water splitting applications. The nanoflower arrays are self-supported on the NF without any binder, possessing the required porosity and structural characteristics. The obtained Co₉S₈-Ni₃S₂/NF displays high hydrogen evolution reaction (HER), as well as oxygen evolution reaction (OER), activities in 1 m KOH solution. The overpotentials exhibited by this system at 25 mA cm⁻² are nearly 277 and 102 mV for HER and OER, respectively, in 1 m KOH solution. Subsequently, the overall water splitting was performed in 1 m KOH solution by employing Co₉S₈-Ni₃S₂/NF as both the anode and cathode, where the system required only 1.49, 1.60, and 1.69 V to deliver the current densities of 10, 25, and 50 mA cm⁻², respectively. Comparison of the activity of Co₉S₈-Ni₃S₂/NF with the state-of-the-art Pt/C and RuO₂ coated on NF displays an enhanced performance for Co₉S₈-Ni₃S₂/NF both in the half-cell as well as in the full cell, emphasizing the significance of the present work. The post analysis of the material after water electrolysis confirms that the surface Co(OH)₂ formed during the course of the reaction serves as the favorable active sites. Overall, the activity modulation achieved in the present case is attributed to the presence of the open-pore morphology of the as formed nanoflowers of Co₉S₈-Ni₃S₂ on NF and the simultaneous presence of the surface Co(OH)₂ along with the highly conducting Co₉S₈-Ni₃S₂ core, which facilitates the adsorption of the reactants and subsequently its conversion into the gaseous products during water electrolysis.     

Synthesis of Novel Aryloxy Propanoyl Thiadiazoles as Potential Antihypertensive Agents

2‐Amino‐5‐aryl/alkyl‐1,3,4‐thiadiazoles 3a‐e were synthesized from aliphatic and aromatic acids and thiosemicarbazide. These 2‐amino‐5‐aryl/alkyl‐1,3,4‐thiadiazoles 3a‐e were condensed with 2‐(naphthalenyloxymethyl) oxirane 4a‐b to prepare some naphthalenyloxy‐propanol amine derivatives 5a‐j . These compounds were synthesized as potential antihypertensive agents.     

On the crustal matter of magnetars

We have investigated some of the properties of dense sub-nuclear matter at the crustal region (both the outer crust and the inner crust region) of a magnetar. The relativistic version of the Thomas-Fermi (TF) model is used in the presence of a strong quantizing magnetic field for the outer crust matter. The compressed matter in the outer crust, which is a crystal of metallic iron, is replaced by a regular array of spherically symmetric Wigner-Seitz (WS) cells. In the inner crust region, a mixture of iron and heavier neutron-rich nuclei along with electrons and free neutrons has been considered. Conventional Harrison-Wheeler (HW) and Bethe-Baym-Pethick (BBP) equation of states are used for the nuclear mass formula. A lot of significant changes in the characteristic properties of dense crustal matter, both at the outer crust and at the inner crust, have been observed.     

Ionic Liquids Can Permanently Modify Porous Silicon Surface Chemistry

To develop ionic liquid/porous silicon (IL/pSi) microarrays we have contact pin‐printed 20 hydrophobic and hydrophilic ionic liquids onto as‐prepared, hydrogen‐passivated porous silicon (ap‐pSi) and then determined the individual IL spot size, shape and associated pSi surface chemistry. The results reveal that the hydrophobic ionic liquids oxidize the ap‐pSi slightly. In contrast, the hydrophilic ionic liquids lead to heavily oxidized pSi (i.e., ox‐pSi). The strong oxidation arises from residual water within the hydrophilic ILs that is delivered from these ILs into the ap‐pSi matrix causing oxidation. This phenomenon is less of an issue in the hydrophobic ILs because their water solubility is substantially lower.     

Radiological and hydrological implications of dissolved radon in alluvial aquifers of western India

Journal of Radioanalytical and Nuclear Chemistry - A study was undertaken to measure the dissolved radon (222Rn) concentration in parts of western India (Southwest Punjab) in order to evaluate its...     

Enhanced ionic conductivity in La3+ and Sr2+ co-doped ceria: carbonate nanocomposite

Ionics - A series of ceria-based nanocomposites consisting of Ce0.85La0.125Sr0.025O1.9125 (LSCO) and binary carbonate mixture Li2CO3–Na2CO3 (LNCO) have been prepared as functional...     

A fourth‐order H1‐Galerkin mixed finite element method for Kuramoto–Sivashinsky equation

A H¹‐Galerkin mixed finite element method is applied to the Kuramoto–Sivashinsky equation by using a splitting technique, which results in a coupled system. The method described in this article may also be considered as a Petrov–Galerkin method with cubic spline space as trial space and piecewise linear space as test space, since the second derivative of a cubic spline is a linear spline. Optimal‐order error estimates are obtained without any restriction on the mesh for both semi‐discrete and fully discrete schemes. The advantage of this method over that presented in Manickam et al., Comput. Math. Appl. vol. 35(6) (1998) pp. 5–25; for the same problem is that the size (i.e., (n + 1) × (n + 1)) of each resulting linear system is less than half of the size of the linear system of the earlier method, where n is the number of subintervals in the partition. Further, there is a requirement of less regularity on exact solution in this method. The results are validated with numerical examples. Finally, instability behavior of the solution is numerically captured with this method.     

Synthesis of NaP zeolite at room temperature and short crystallization time by sonochemical method

NaP zeolite nano crystals were synthesized by sonochemical method at room temperature with crystallization time of 3 h. For comparison, to insure the effect of sonochemical method, the hydrothermal method at conventional synthesis condition, with same initial sol composition was studied. NaP zeolites are directly formed by ultrasonic treatment without the application of autogenous pressure and also hydrothermal treatment. The effect of ultrasonic energy and irradiation time showed that with increasing sonication energy, the crystallinity of the powders decreased but phase purity remain unchanged. The synthesized powders were characterized by XRD, IR, DTA TGA, FESEM, and TEM analysis. FESEM images revealed that 50 nm zeolite crystals were formed at room temperature by using sonochemical method. However, agglomerated particles having cactus/cabbage like structure was obtained by sonochemical method followed by hydrothermal treatment. In sonochemical process, formation of cavitation and the collapsing of bubbles produced huge energy which is sufficient for crystallization of zeolite compared to that supplied by hydrothermal process for conventional synthesis. With increasing irradiation energy and time, the crystallinity of the synthesized zeolite samples increased slightly.