PVC-supported SP composite membrane: its synthesis,physicochemical, and electrochemical characterization

Journal of Solid State Electrochemistry - Polyvinyl chloride (PVC)-supported stannous phosphate (SP) is a newly synthesized composite material used to make porous, mechanically, and thermally...     

Mathematical thinking and origami

The purpose of this paper is to describe the mathematics that emanates from the construction of an origami box. We first construct a simple origami box from a rectangular sheet and then discuss some of the mathematical questions that arise in the context of geometry and calculus.     

Rational Design of Highly Efficient One-pot Synthesis of Ternary PtNiCo/FTO Nanocatalyst for Hydroquinone and Catechol Sensing

In this work, we present a simple and efficient method for preparation of widely dispersed PtNiCo nanocatalyst on FTO without the use of any heavy complex structure. The proposed nanocatalyst enhances the chemical interaction of PtNiCo/FTO and increases its catalytic activity, which was used for electrochemical sensing of catechol and hydroquinone. The surface morphology was characterized by TEM, HRTEM, and XRD. The size of the PtNiCo/FTO octahedrons nanocatalyst was about 0.35–4 nm. Gradual increase of concentration exhibited linearity in oxidation peak response up to 1100 μM with a low detection limit of 0.79 μM for HQ and 1.05 μM for CC. The sensitivity is 1035 μAmM⁻¹ cm⁻² for catechol and 1197 μAmM⁻¹ cm⁻² for hydroquinone. The prepared nanomaterial/sensor applied to real water samples with good reproducibility (98–99 %).     

Pore-scale Network Modeling of Three-Phase Flow Based on Thermodynamically Consistent Threshold Capillary Pressures. II. Results

We use the model described in Zolfaghari and Piri (Transp Porous Media, 2016) to predict two- and three-phase relative permeabilities and residual saturations for different saturation histories. The results are rigorously validated against their experimentally measured counterparts available in the literature. We show the relevance of thermodynamically consistent threshold capillary pressures and presence of oil cusps for significantly improving the predictive capabilities of the model at low oil saturations. We study systems with wetting and spreading oil layers and cusps. Three independent experimental data sets representing different rock samples and fluid systems are investigated in this work. Different disordered networks are used to represent the pore spaces in which different sets of experiments were performed, i.e., Berea, Bentheimer, and reservoir sandstones. All three-phase equilibrium interfacial tensions used for the simulation of three-phase experimental data are measured and used in the model’s validation. We use a fixed set of parameters, i.e., the input network (to represent the pore space) and contact angles (to represent the wettability state), for all experiments belonging to a data set. Incorporation of the MSP method for capillary pressure calculations and cusp analysis significantly improves the agreement between the model’s predictions of relative permeabilities and residual oil saturations with experimental data.     

Constructive struggle in geometry classrooms

The purpose of these notes is to provide examples of large-scale geometry problems that have the potential to promote constructive struggling in high-school geometry classrooms. These problems are suitable for being explored in a dynamic geometry environment. The notes also contain brief sketches of solutions to the two problems.     

Numerical simulation for Darcy–Forchheimer three-dimensional rotating flow of nanofluid with prescribed heat and mass flux conditions

Journal of Thermal Analysis and Calorimetry - Darcy–Forchheimer three-dimensional rotating flow of nanoliquid with prescribed heat and mass flux conditions is addressed. Flow is generated by...     

Copper‐supported β‐cyclodextrin‐functionalized magnetic nanoparticles: Efficient multifunctional catalyst for one‐pot ‘green’ synthesis of 1,2,3‐triazolylquinazolinone derivatives

The green synthesis of 2‐(4‐((1‐phenyl‐1H‐1,2,3‐triazol‐4‐yl)oxy)phenyl)quinazolin‐4(3H)‐one derivatives is reported. The catalyst for this synthesis is copper‐supported β‐cyclodextrin‐functionalized magnetic silica–iron oxide nanoparticles ([Cu@BCD@SiO₂@SPION]). [Cu@BCD@SiO₂@SPION] simultaneously catalyses ‘click’ reaction, oxidation of C? N bond and multicomponent reaction. The desired 1,2,3‐triazolylquinazolinone product is easily obtained in water at room temperature under mild reaction conditions. Another advantage of the catalyst is its reusability. It can simply be isolated using an external magnet and reused in reactions with no significant decrease in catalyst efficiency. Transmission electron microscopy, scanning electron microscopy, vibrating sample magnetometry and Fourier transform infrared spectroscopy are used for exact characterization of the [Cu@BCD@SiO₂@SPION] catalyst.     

An interesting property of hexagons

These notes discuss several related problems in geometry that can be explored in a dynamic geometry environment. The problems involve an interesting property of hexagons.     

Ionic liquid-induced conversion of methoxymethyl-protected alcohols into nitriles and iodides using [Hmim][NO3]

This Letter reports a one-pot efficient conversion of methoxymethyl-ethers into their corresponding nitriles and iodides using the ionic liquid, 1-methyl-3H-imidazolium nitrate ([Hmim][NO₃]) under microwave irradiation. A variety of products were prepared in high yields using this method.     

An unexpected property of quadrilaterals*

These notes discuss several related propositions in geometry that can be explored in a dynamic geometry environment. The propositions involve an unexpected property of quadrilaterals.