Fractional order heat conduction law in magneto-thermoelasticity involving two temperatures

A new mathematical model of two-temperature magneto-thermoelasticity is constructed where the fractional order heat conduction law is considered. The state space approach is adopted for the solution of one-dimensional application for a perfect conducting half-space of elastic material with heat sources distribution in the presence of a transverse magnetic field. The Laplace-transform technique is used. A numerical method is employed for the inversion of the Laplace transforms. According to the numerical results and its graphs, conclusions about the new theory are given. Some comparisons are shown in figures to estimate the effects of the temperature discrepancy and the fractional order parameter on all the studied fields.     

Reactivity of sugar cane bagasse as a natural solid phase extractor for selective removal of Fe(III) and heavy-metal ions from natural water samples

This work introduces the feasibility of using sugar cane bagasse (SCB) – a sugar cane industry waste – as a selective solid phase extractor for Fe(III). The order of metal uptake capacities in μmol g^?1 for the extraction of six tested metal ions from aqueous solution using static technique is Fe(III) > Cu(II) > Pb(II) > Zn(II) > Cd(II) > Co(II). Since SCB exhibits remarkable binding characteristics for Fe(III), special interest was devoted for optimizing its uptake and studying its selectivity properties under static and dynamic conditions. In this respect, batch experiments were carried out at the pH range 1.0–4.0, initial concentration of metal ion (10–100 μmol), weight of phase (25, 50, 75, 100, 125 and 150 mg) and shaking time (10, 30, 45, 60, 90, 120 and 150 min). FT-IR spectra of SCB before and after uptake of Fe(III) were recorded to explore the nature of the functional groups responsible for binding of Fe(III) onto the studied natural biosorbent. The equilibrium data were better fitted with Langmuir model (r² = 0.985) than Freundlich model (r² = 0.934). Moreover, Fe(III) sorption was fast and completed within 60 min. The adsorption kinetics data were best fitted with the pseudo-second-order type. As a view to find a suitable application of SCB based on its unique property as a benign sorbent, it was found that, Fe(III) spiked natural water samples such as doubly distilled water (DDW), drinking tap water (DTW), natural drinking water (NDW), ground water (GW) and Nile River water (NRW) was quantitatively recovered (>95.0%) using batch and column experiments, with no matrix interferences.     

Selective separation of silver(I) and mercury(II) ions in natural water samples using alumina modified thiouracil derivatives as new solid phase extractors

A simple and reliable solid-phase extraction (SPE) method has been developed to synthesise two new sorbents: 6-propyl-2-thiouracil and 5,6-diamino-2-thiouracil physically loaded onto alumina surface, phases I and II, respectively. The synthesis of these new phases has been confirmed by IR-spectroscopy. The surface concentrations of the organic moieties were determined to be 0.182 and 0.562 mmol g^?1 for phases I and II, respectively. The evaluation of the selectivity and metal uptake properties incorporated in these two alumina phases were also studied and discussed for 10 different metal ions: Ca(II), Fe(III), Co(II), Ni(II), Cu(II), Zn(II), Cd(II), Hg(II), Pb(II) and Ag(I) under different controlling factors. The data obtained clearly indicated that the new SP-extractors have the highest affinity for retention of Hg(II) ions. Selective separation of Hg(II) from Ag(I) as one of the most interfering ion, in addition to the other eight coexisting metal ions under investigation, was achieved successfully using the new sorbents at pH = 9.0 under static conditions. Therefore, Hg(II) exhibits major retention percentage (100.0%) using phase I or II. However, Ag(I) exhibits minor retention percentage equal to 1.33% using phase I and 0.67% using phase II. On the other hand, the retention percentage of the other eight metal ions ranged (0.0–3.08%) using phase I and (0.0–1.54%) using phase II at the same pH. The new phases were applied for separation and determination of trace amounts of Hg(II) and Ag(I) spiked natural water samples using cold vapour atomic absorption spectroscopy and atomic absorption spectroscopy with no matrix interference. The high recovery values of Hg(II) and Ag(I) obtained using phases I and II were ranged 98.9 ± 0.1–99.2 ± 0.05% along with a good precision (RSD% 0.01–0.502%, N = 3) demonstrate the accuracy and validity of the new sorbents for separation and determination of Hg(II) and Ag(I).     

A Novel and Convenient Preparation of 1-(γ-Aminoalkyl)-Substituted 1,2,4-Triazoles

1-(α-Aminomethyl)-1,2,4-triazoles readily add to enol ethers or enamides to give novel classes of compounds, 1-(γ-amino-α-alkoxy)propyl- (8) and 1-(γ-amino-α-amido)propyl- (10) substituted 1,2,4-triazoles, in excellent yields.     

γ-Al2O3-Supported 12-Tungstosilicic Acid as an Efficient Heterogeneous Catalyst for the Synthesis of α-Aminonitrile

The multicomponent Strecker reaction using trimethylsilyle cyanide was performed in very short reaction times, and α-aminonitriles were prepared in excellent yields in the presence of a catalytic amount of alumina-supported tungstosilicic acid.     

Investigation of the catalytic activity of a Pd/biphenyl-based phosphine system in the Ullmann homocoupling of aryl bromides

We described Ullmann homocoupling promoted by a Pd/biphenyl-based phosphine system using DMF as solvent. Using Hammett equation it is found that the rate determining step of the reaction depends on the electronic nature of substituents of aryl bromides. Increase the rate of reaction with decreasing the electron donating of the substituent from NH₂ to H suggesting an oxidative addition step as the rate determining step. Decrease the rate of reaction with increasing the electron-withdrawing ability of the substituent from H to NO₂ indicating a reductive elimination step as the rate determining step.     

Cs_xH_(3-x)PW_(12)O_(40) heteropoly salts catalyzed quinoline synthesis via Friedl(a|¨)nder reaction

Various type of cesium partially substituted phosphotungstate,Cs_xH_3-xPW₁₂O₄₀（x = 1.0,2.0 and 2.5）,were synthesized and their catalytic activities were investigated in the synthesis of quinoline.It was shown that catalytic activities of these catalysts correlated to surface acidity and total number of acidic sites.Finally,a series of quinoline derivatives were synthesized with Cs_2.5H_0.5PW₁₂O₄₀ via the Friedlander reaction in high to excellent yields and the plausible mechanism was proposed.Simple experiment,catalyst reusability,short reaction time and preclusion of toxic solvent are the advantages of this method.     

New Amphiphilic Ionic Liquids for the Demulsification of Water-in-Heavy Crude Oil Emulsion

This work aimed to use abietic acid (AA), as a widely available natural product, as a precursor for the synthesis of two new amphiphilic ionic liquids (AILs) and apply them as effective demulsifiers for water-in-crude oil (W/O) emulsions. AA was esterified using tetraethylene glycol (TEG) in the presence of p-toluene sulfonic acid (PTSA) as a catalyst obtaining the corresponding ester (AATG). AATG was reacted with 1-vinylimidazole (VIM) throughout the Diels–Alder reaction, forming the corresponding adduct (ATI). Following this, ATI was quaternized using alkyl iodides, ethyl iodide (EI), and hexyl iodide (HI) to obtain the corresponding AILs, ATEI-IL, and ATHI-IL, respectively. The chemical structure, surface activity, thermal stability, and relative solubility number (RSN) were investigated using different techniques. The efficiency of ATEI-IL and ATHI-IL to demulsify W/O emulsions in different crude oil: brine volumetric ratios were evaluated. ATEI-IL and ATHI-IL achieved promising results as demulsifiers. Their demulsification efficiency increased as the brine ratios decreased where their efficiency reached 100% at the crude oil: brine ratio (90:10), even at low concentrations.     

Mathematical model for the novel coronavirus (2019-nCOV) with clinical data using fractional operator

Coronavirus infection (COVID-19) is a considerably dangerous disease with a high demise rate around the world. There is no known vaccination or medicine until our time because the unknown aspects of the virus are more significant than our theoretical and experimental knowledge. One of the most effective strategies for comprehending and controlling the spread of this epidemic is to model it using a powerful mathematical model. However, mathematical modeling with a fractional operator can provide explanations for the disease's possibility and severity. Accordingly, basic information will be provided to identify the kind of measure and intrusion that will be required to control the disease's progress. In this study, we propose using a fractional-order SEIARPQ model with the Caputo sense to model the coronavirus (COVID-19) pandemic, which has never been done before in the literature. The stability analysis, existence, uniqueness theorems, and numerical solutions of such a model are displayed. All results were numerically simulated using MATLAB programming. The current study supports the applicability and influence of fractional operators on real-world problems.