Solution In Presence Research Articles

Rheo-optics of giant micelles: SALS patterns of cetyltrimethylammonium tosylate solutions in presence of sodium bromide

In this work, we present a systematic study based on Small-Angle Light Scattering (SALS) patterns of the simple shear flow response of semi-diluted solutions of cetyltrimethylammonium tosylate (CTAT; 5.5 wt.% - 0.12 M) in the presence of sodium bromide (NaBr) at different [NaBr]={0,0.12,0.19,0.25,0.3} M concentrations. We evidence a relationship between rheological and light scattering data that reveals a transition into a fast-breaking regime in the dynamics of wormlike micelles formed by the CTAT/NaBr system (Macías et al., 2011; Fierro et al., 2021). This transition into a micellar fast-breaking regime with salt addition ([NaBr]≥0) appears marked by the following features: (i) a decrease in the relaxation time of the material λ0, accompanied by (ii) a decrease of the viscosity level at low shear rates η0 (Macías et al., 2011; Fierro et al., 2021; Schubert et al., 2003; Alkschbirs et al., 2015; Bandyopadhyay et al., 2003). With these, (iii) the formation of butterfly-like patterns is recorded originating from concentration fluctuations, evolution that is accompanied by: (iv) shear banding in the form of non-monotonic flow curves and (v) slow oscillatory transient responses in start-up flow tests captured theoretically with the Bautista–Manero–Puig (BMP) model. In addition, the Cox–Merz rule is fulfilled at molar salt-to-surfactant ratios of R≥1.5. This results in shorter structure-recovery time-scales than the characteristic-time of the flow (Macías et al., 2011; Fierro et al., 2021; Manero et al., 2002). In the case of the elastic modulus G0, the variation was small, which suggests a transition from an entangled to a multiconnected network, as suggested by Kadoma & van Egmond (1997), Kadoma et al. (1997) and Fierro et al. (2021). From a theoretical perspective, we provide predictions for the shear–stress and the first normal-stress growth coefficients in transient start-up simple shear flow using the BMP model. Here, banding R=1.5 solutions display overshot responses at relatively high shear rates (γ̇=10−30s−1), in-line with experimental findings on the start-up flow of wormlike micellar solutions (Soltero et al., 1999; Lerouge et al., 2004; Hu & Lips 2005; Pipe et al., 2010; Mohammadigoushki et al., 2019). Our results are consistent with those reported in other investigations (Macías et al., 2011; Fierro et al., 2021; Schubert et al., 2003; Alkschbirs et al., 2015; Bandyopadhyay et al., 2003; Kadoma et al., 1997; Soltero et al., 1999; Lerouge et al., 2004; Hu & Lips 2005; López-Barrón et al., 2014) and reveal the influence of the Br−-ion used on the mechanical and optical response of the CTAT-NaBr system.

Performance evaluation of sugarcane bagasse biochar based fixed bed column for removal of triclosan from aqueous solution in presence of humic acid: Mechanism, kinetics and safety

Triclosan (TCS), an emerging pollutant emerges as a notable contributor to adverse impacts on aquatic organisms owing to its widespread use during COVID19. The current study aims to investigate the efficiency of sugarcane bagasse biochar (SBB) for removal of triclosan (TCS), an emerging pollutant in aquatic ecosystems in presence of humic acid from aqueous solution through batch and column studies. In batch study, SBB prepared at pyrolysis temperature of 400 °C showed highest adsorption of TCS. Langmuir isotherm model showed highest adsorption of 68.49 mg g−1 at pH 7.0. A 90 % reduction in TCS was accomplished with 0.625 g L−1 of SBB-400 °C. Adsorption kinetic modelling was well fitted to pseudo-second order model signifying that rate of adsorption on SBB-400 °C mainly depends on chemisorption. TCS removal was not significantly inhibited in presence of 5, 10 and 25 mg L−1humic acid concentrations. Column experiments of continuous flow biochar-bed column with the aqueous solution spiked with TCS (100 mg L−1) at a flow rate of 50 mL min−1 showed 99 % removal efficiency. Thomas model and Yoon-Nelson model signified the breakthrough behaviour of TCS adsorption on the column and the experimental data were in good agreement with the expected values. Bioassay studies on Chlorella vulgaris exhibited that percentage inhibition (8 %) in algal cell counts was significantly less in the SBB treated TCS water when compared with control (untreated water containing TCS). The designed column is highly efficient, effective and eco-friendly approach for TCS removal.

Wet chemical synthesis of self-standing single-crystalline copper telluride Cu7Te4 nanorods: Characterizations and mechanism

Single crystalline Cu7Te4 nanorods were obtained from a two-step synthesis route. The first step is the electrochemical deposition of self-standing tellurium nanorods on Pt-coated glass electrode in an ionic liquid electrolyte acting as a structuring solvent. Afterwards, soft chemical transformation in Cu7Te4 is performed by immersing the Te-covered electrode in a Cu(II) solution in presence of ascorbic acid acting as reducer at room temperature and atmospheric pressure. Tellurium seems to undergo a reaction of disproportionation induced by the simultaneous presence of Cu(II) and Cu(I) into Te(IV) and Cu7Te4, which is supported by thermodynamic considerations. The copper telluride nanorods were analyzed by XRD, SEM-EDX, HRTEM-FFT/SAED, EELS and XPS that allowed to set the required parameters in terms of molar ratio of precursors in the bath to induce the targeted chemical reaction. The analyses highlight the obtention of single crystalline Cu7Te4 with a homogeneous chemical composition along the nanorods. A detailed analysis of the microstructure shows the presence of stacking local defects, leading to curved nanostructures.

Effect of oxalic acid on the corrosion of 6063 aluminum alloy in ethylene glycol-water solution in presence of ammonium alcohol polyvinyl phosphate

The corrosion behavior of 6063 aluminum alloy in glycol-water solution with different concentrations of oxalic acid under different temperatures and the inhibitve effect of ammonium alcohol polyvinyl phosphate (AAPP) on its corrosion were investigated by weight loss experiment, electrochemical measurements and scanning electron microscopy (SEM). The results showed that low concentration of oxalic acid had a certain inhibitory effect on the corrosion of 6063 aluminum alloy in glycol-water solution, but high concentration of oxalic acid accelerated its corrosion. AAPP was a mixed type corrosion inhibitor with a predominantly anodic inhibition for 6063 aluminum alloy in a ethylene glycol-water solution containing oxalic acid, its corrosion inhibition efficiency was up to 90% at a concentration of 0.5 g/L under 30 ℃. The effect of AAPP on the surface of 6063 aluminum alloy obeyed the Langmuir isotherm equation. And the corrosion inhibition of AAPP for 6063 aluminum alloy was further confirmed by the results of weight loss experiment and SEM.

Corrosion inhibition of 8-HQ for AA5052 in 3 wt% NaCl solution in presence of trace Cu2+ ions: Electrochemical/surface studies, DFT/MD modeling

In this paper, the effect of Cu2+ ions on corrosion inhibition of 8-hydroxyquinoline (8-HQ) for AA5052 aluminum alloy in the simulated seawater solution has been studied by weight loss experiments, electrochemical measurements and surface analysis. 8-HQ inhibits the corrosion of AA5052 aluminum alloy in 3 wt% NaCl solutions very well, resulting in a positive shift in corrosion potential. The 0.01 mg/L of Cu2+ ions can deteriorate the corrosion inhibition of 8-HQ at low concentrations. This behavior is interpreted on the basis of deposition of copper by displacement on the defects of the corrosion inhibition film of 8-HQ. When the concentration of 8-HQ reached 5 mg/L, the presence of 0.01 mg/L Cu2+ ions increase the corrosion inhibition efficiency of 8-HQ by 6.27%. 8-HQ shows efficient inhibition at a relative high concentration, suggesting that the chelate formed by Cu2+ ions and 8-HQ can repair the defects of the 8-HQ inhibitive film on aluminum surface. The complex film would suppress the partial cathodic reaction and lead to the improved corrosion inhibition.

Daylight-driven catalytic removal of pyridine over Ag-embedded ZnO porous nanosheets

Structure of heterogeneous photocatalyst with adequate coupling interface has an important effect on energy transfer and photoinduced electron-hole pairs separation. In this work, Ag-embedded ZnO heterogeneous porous nanosheets (PNSs) have been synthesized by thermal pyrolyzing of Ag2CO3-modified Zn5(CO3)2(OH)6 nanosheets at 400 °C. Photoelectron spectra and X-ray diffraction measurements demonstrate that there exists an adequate coupling between Ag and ZnO phase. Ag-embedded ZnO PNSs, in contrast to bare ZnO PNSs, performs 6-fold enhancement in natural-daylight-driven degradation of pyridine which requires participation of ·OH radicals. This result demonstrates that the adequate coupling interface between Ag and ZnO for Ag-embedded ZnO PNSs promotes an energy transfer from local surface plasma resonance of Ag nanoparticles to bound excitons in ZnO region, activating them to dissociate into free photoinduced carriers. In addition, external control experiments indicate that the best photocatalytic degradation is obtained in the 7–10 pH range of 10 mg/L pyridine solution in presence of 0.5 g/L photocatalyst dosage. The optimal Ag-embedded ZnO PNSs under outdoor daylight irradiation also performs an efficiently photocatalytic degradability for pyridine present in ground water. Our work provides a new approach to fabricate ZnO-based photocatalyst with efficient energy transfer for treating stubborn organics present in polluted water.

Uncertainty quantification analysis for simulation of wakes in wind-farms using a stochastic RANS solver, compared with a deep learning approach

Quantification of uncertainties in Reynolds–Averaged Navier–Stokes (RANS) simulations has gained a considerable interest in turbulence modeling. We present two different approaches for the quantification and propagation of model-form and operational uncertainties in context of wind turbine RANS simulations. The first approach is based on a stochastic RANS solver in OpenFOAM using intrusive polynomial chaos method (Parekh and Verstappen, 2023). Here the uncertainties are propagated through a single (large) simulation for the coupled coefficients of the polynomial expansion. The second approach is a surrogate based uncertainty quantification (SBUQ) method. The surrogate model comprises of a 3D U-Net neural network (trained over a single wind turbine) combined with a wake superposition model in order to the prediction of flow field in an array of wind turbines. The above-mentioned approaches are applied for uncertainty quantification analysis in RANS simulations of two turbulent engineering flow problems — (i) a wake past a single wind turbine, and (ii) wake interactions and power losses in an array of wind turbines. The results show that the uncertain RANS solutions from the two approaches are able to reasonably capture the reference high-fidelity solution. We also discuss comparisons between the two approaches including computational cost, applicability, generality etc. The two methods can be further explored and applied to engineering applications where it is critical to compute the turbulent RANS solution in presence of various sources of uncertainties.

Fenton-like photocatalyzed degradation of dibutyl phthalate with goethite and carboxylic acids

Detailed investigation of photocatalyzed degradation of dibutyl phthalate (DBP), an endocrine disrupter, in the presence of α-FeOOH (goethite) and different carboxylic acids is the focus of this study. To get a better insight into the efficiency of the degradation, the influence of different parameters, such as concentration of total Fe and Fe(II), dissolved oxygen, DBP concentration, pH and salinity is investigated. The reaction mechanism consists of several interrelationship steps. The first step is the chemical reaction of carboxylic acid groups of the organic acids with hydroxyl groups of the α-FeOOH and a charge transfer upon illumination generating Fe(II). The second step is the release of Fe(II) into the solution followed by H2O2 oxidation to form highly photoactive hydroxyl complex of iron(III) and ˙OH. Simultaneously, the superoxide radical O2˙− and hydroperoxyl radical is formed in acidic solutions in presence of carboxylic acids as well. This mechanism explains the genesis of different reactive species oxidizing DBP. From the variety of the studied carboxylic acids (oxalic, citric, salicylic, pyruvic, maleic, and fumaric), oxalic acid is the best Fe-ligand for the photoreductive dissolution of goethite. Concentrations of the total amount of Fe and its dissociated forms Fe(II) as well as oxygen and hydroxyl radicals play a fundamental role in efficiency of DBP degradation. The photodegradation of DBP with goethite and the use of suitable carboxylic acids under optimized reaction conditions could be an efficient process for decontamination of polluted waters.

Anion-selective “Turn-on” two color phosphorescent probes based on “Pd-Pd” interaction of a series of cyclometallated Palladium (II) complexes induced by a self-assembly in aqueous solution

Herein, three pairs of cationic cyclometallated palladium (II) complexes with different types of C^N ligands, which is non-phosphorescent in aqueous solution, interestingly, they can be utilized as turn-on blue phosphorescent probes selectively for ClO−, HSO3− and CO32−, and turn-on green phosphorescent probe for HSO3− in aqueous solution. These different phosphorescent turn-on responses of Pd(II) complexes could be attributed to the degree of coordination and electrostatic interaction between them with specific anion. It suggests that the selectivity towards specific anion of these cyclometallated Pd(II) complexes can be further improved by rationally tuning the structure and enhancing aromaticity of C^N ligand. Our study reveals that these specific species of anions can effectively induce self-assembly of Pd(II) compounds with different C^N ligand based on PdPd interaction, the aggregation and morphology of palladium complex with anion in aqueous media was also investigated by various means of 1H NMR, UV/Vis, fluorescence spectra, and dynamic light scattering (DLS) analysis. Moreover, transmission electron microscopy (TEM) reveals that nanowires with increased length of diameters of Pd complexes can form in aqueous solution in presence of anions with different high concentration. Furthermore, the cellular uptake and location of Pd2a was also investigated by confocal imaging for the first time. DFT calculation of monomer and dimer of Pd2a was also performed, which is helpful to explain the turn on phosphorescent effect during self-assembly process.

Insights into the complexation and oxidation of quercetin and luteolin in aqueous solutions in presence of selected metal cations

Flavonoids are natural antioxidants that can be used for the chelation of metal ions to treat metal toxicity. Ideal chelators should form stable metal complexes and be resistant to oxidative degradation reactions in aqueous solutions at physiological conditions (pH 7.4 and 37 °C). In this work, the complexation and oxidation of quercetin and luteolin with selected metal cations (i.e. Cr(III), Mn(II), Fe(III), Co(II), Ni(II), Cu(II), Zn(II), and Al(III)) in aqueous solutions at pH 4 and 7.4 is discussed. Using UV–Vis, RP-UHPLC-PDA-MS, ESI-MS and 1H NMR, information about the complexing ability, stoichiometry, and the preferred metal binding sites was obtained. At pH 7.4, all metal ions were complexed by luteolin and quercetin, whereas at pH 4 both flavonoids only formed complexes with the trivalent metal cations (i.e. Cr(III), Fe(III), and Al(III)). No clear preference for any of the complexation sites was observed for quercetin and luteolin. UV–Vis and RP-UHPLC-PDA-MS showed that, at pH 7.4, chelation of quercetin was followed by metal-mediated oxidation resulting in degradation of quercetin. On the contrary, luteolin complexes with metal cations were stable and no oxidative degradation of luteolin was observed. The oxidative degradation pathway of quercetin was investigated by incubation in H218O, which showed that the oxidation occurs via both oxygenation and hydroxylation mechanisms, the latter being the preferred pathway for the trivalent metal ions.Our results indicate that luteolin is a more suitable chelating agent of Al(III) and first-row transition metal cations due to its higher oxidative stability and its ability to form stable complexes in aqueous solutions at pH 7.4.

A GPU-based 2D viscous flow model with variable density and heat exchange

Numerical simulation of unsteady viscous flow over variable topography under the influence of temperature changes is a challenge. In order to apply the model to large domains with complex topography, it becomes mandatory to reduce the model complexity from 3D to 2D by depth averaging the equations and to apply massive parallelization techniques for an efficient simulation. The depth averaged mass continuity, momentum and internal energy equations, combined with suitable friction laws, can be used for this type of flows. Variations in temperature can be accounted for from internal energy changes with density changing accordingly. The resulting system is solved using a finite volume technique on unstructured triangular grids well suited for problems over variable topography. A generic model applicable to a wide range of viscous fluids and validated with synthetic cases is presented to evaluate the performance of the numerical solution in presence of both external thermal forcing functions and discontinuous initial conditions. Finally, the model is applied to a realistic application and calibration to a particular case of lava flow taking into consideration variable density, viscosity and yield stress with temperature . A heat transfer with the air is included to consider the lava cooling. The numerical results of the lava front advance are compared to the Copernicus satellite observations at different dates. The efficiency of the GPU implementation allows to simulate a 11 day event in less than 1.7 h of simulation.

Photo-reduction of nitrate to nitrite in aqueous solution in presence of CaO: Selectivity, mechanism and application

Nitrate (NO3−) photolysis leads to various nitrogenous products, which depends on the reaction conditions and solution properties. How to regulate the composition of products is an important issue. Herein, we found that the involvement of CaO in the NO3− photolysis could selectively reduce NO3− to nitrite (NO2−). Almost 100 % NO2− selectivity was achieved in CaO/UV/NO3− system at initial pH (3–10), initial NO3− concentration (5–45 mg N/L) and CaO dosage (1–6 g/L). The high NO2− selectivity in CaO/UV/NO3− system was attributed to the rich basic sites and paramagnetic surface species of CaO, which captured nitrogen oxides (NOX) and promoted the conversion of NOX to NO2−, respectively. The two-step reduction strategy of CaO/UV coupled with H2NSO3H was used to remove NO3− in wastewater, in which NO3− was firstly reduced to NO2−, then the produced NO2− was further reduced to N2 by H2NSO3H. As for secondary effluent of municipal wastewater with initial NO3− concentration of 30 mg N/L, 93 % removal of NO3− and 100 % of N2 selectivity were achieved at CaO dosage of 2 g/L and H2NSO3H dosage of 0.4 g/L.

Studies on nano crystalline copper doped Nickel Zinc ferrites for optoelectronic applications

Investigation of optical and dielectric properties of nanocrystalline Ni0.65Zn0.35 Cu x Fe(2-2x/3) O4 (for x = 0.00–0.05 in steps of 0.01) ferrites synthesized using hydrothermal route is successfully carried out. Two distinct analytical spectroscopic methods with Dichloro – 5,6-Dicyano – 1,4-Benzo quinone (DDQ) and Bromo Phenol Blue (BPB) are adopted to observe the UV–visible absorption spectroscopy in the dispersed solutions of all samples. The formation of ion pair complex in the presence of BPB results in two distinct absorption edges in the visible region, around 440 nm and 580 nm in the present ferrite samples. Application of Tauc's formalism gives rise to two optical band gap values Eg1 and Eg2 in the range of 2.12–2.40 eV and 3.583–3.674 eV, respectively. The formation of charge transfer complex with all sample solutions in presence of DDQ reagent results in sharp absorption edges in the UV-region around 306 nm wavelength. An initial rise followed by continuous drop in band gap values ranging from 3.814 to 3.824 eV is observed from Tauc's plots. The optimum refractive index (n) values calculated for the three types of band gap values using empirical relations display the optical absorption potentiality of Ni–Cu–Zn nano ferrites in both Visible and UV – regions. Variation of band gap values is ascribed to the lattice strain effect, quantum confinement and narrowing band gap effects. Real part of dielectric constant (ε′), dielectric loss factor (tanδ) and ac-conductivity(σac) are studied for all samples at room temperature with in the frequency range of 42 Hz to 5 MHz. The values of ε′ and tanδ are observed to decrease with increase in frequency, while that of σac are found to increase with increase in frequency. Improved dielectric properties, existence of optical band-gap values observed in the present Ni–Cu–Zn ferrites promote these materials for their utility in optoelectronic devices and high frequency applications.

Wormholes models in f(R) gravity inspired by non-compact matter source

This paper encompassed various physically realistic models of static and spherically symmetric wormholes in extended [Formula: see text] gravitational framework by incorporating the features of non-compact matter density distribution of non-commutative geometry. For this assessment, we formulated the [Formula: see text] field equations and obtained their exact analytical solutions in presence of cosmologically well-consistent power law type [Formula: see text] corresponding to distinct values of the parameter [Formula: see text]. We conducted the physical adequacy of such proposed solutions through the graphical manifestation for the necessary existence of wormhole structures. Moreover, we revisited our field equations with a feasible choice of shape function together with reconstructed form of [Formula: see text] to provide an again authentication to the existence of wormholes structures. These all implications vigorously depicted that our discussed models are able to expect the required wormhole structures.

Saussurea obvallatta leaves extract as a potential eco-friendly corrosion inhibitor for mild steel in 1 M HCl

The extract of saussurea obvallatta leaves (SOLE) has been examined for corrosion inhibition studies for mild steel (MS) in 1 M HCl solution by electrochemical impedance spectroscopy (EIS), potentiodynamic polarization and traditional mass change measurements. SOLE controlled maximum of 90 % corrosion rate of MS in 1 M HCl solution at 200 ppm of SOLE. SEM-EDX, AFM and Contact angle images revealed that, MS surface was least affected by the acid solution in presence of SOLE. FT-IR and UV–Visible absorption spectral values established the set of a corrosion defensive layer over the MS surface. Potentiodynamic measurement revealed that SOLE act as a both anodic and cathodic type of inhibitor. Quantum chemical calculations shows that, the EHOMO as an electron donor of SOLE donate electrons to appropriate acceptor molecules to the vacant d orbital of Fe atoms of MS. Un-filled 3d orbital of MS could bind with HOMO of the inhibitors. On the other hand filled 4s orbital could donate the electron to LUMO of the inhibitor as oftenly ELUMO indicates the ability of molecules to accept electrons. Variation of experimental temperature studies revealed that the stability of the protective layer decreased at higher temperature and corrosion activation energies increased in the addition of SOLE.

Effect of different valent ions (Na+, Ca2+ & Y3+) on structural and morphological features of protein (BSA) thin films adsorbed on hydrophobic silicon (H-Si) surface

Structure and morphology of bovine serum albumin (BSA) films adsorbed on hydrophobic silicon (H-Si) surface from BSA solution in presence of different cationic ions (Na+, Ca2+ and Y3+) are studied. Electron density profile as obtained from X-ray reflectivity analysis shows that ≈ 55 Å thick monolayer of pure BSA is adsorbed on H-Si surface, while atomic force microscopy image displays its globular morphology. A bilayer of globular BSA molecules of average thickness ≈ 85 Å is formed on the H-Si surface at 1–10 mM of Na+ and Ca2+ ions. However, Y3+ ions favor the immobilization of a tri-layer of BSA on H-Si surface except for 5 mM, at which a tetralayer is formed due to the effect of re-entrant condensation of BSA solution. Elemental mapping analysis as obtained from scanning electron microscopy confirms that the attachment of Y3+ ions is higher in comparison with Na+ and Ca2+ ions due to maximum charge density of hydrated Y3+ ions. The contact angle results display intermediate hydrophobicity for Na+ ions, whereas minimum and maximum hydrophobicity for Ca2+ and Y3+ ions interacted protein films, respectively. It is found that the adsorption of BSA is relatively higher in presence of all ions on hydrophobic surface than hydrophilic. All the adsorbed BSA films are found mostly stable with time.

Dual theory for maximally mathcal{N} extended flat supergravity

Maximally mathcal{N} extended 2 + 1 dimensional flat supergravity theories exist for a class of super-Poincaré algebras for arbitrary mathcal{N} . They have rich asymptotic structures and contain all interesting topological supergravity solutions in presence of non-trivial holonomy. For the asymptotic symmetry algebra being a suitable flat limit of the superconformal algebra, which is an infinite dimensional extension of two copies of Osp( mathcal{N} |2; R) group, we have found the 1 + 1 dimensional chiral WZW model as the dual quantum field theory that describes the dynamics of these solutions. In the Hamiltonian analysis, the reduced phase space resembles a flat super Liouville theory.

Comparative FE biomechanical and microbial adhesion analyses on an implanted humerus

ObjectiveIn this study a multi fragment humeral fracture, treated with locking plate system implant, was investigate and compared with a healthy humerus by the mining of a Finite Element (FE) analysis. Locking plate implant, in this case AxSOS 3® Titanium produced by Stryker is the preferred solution in presence of multiple fracture or osteoporosis. MethodsLoading conditions were imposed by rotating of 52,5° respect the vertical axe, both the humeri (healthy and fractured), fixing distal end, and loading the top of bones with a vertical force of 543 N (Newton). This finite element analysis aimed to compare stability of implanted humerus, implant-bone interface, stress shielding, with those related to a healthy one. A microbial adhesion analysis was also performed on the implant's material. ResultsResults obtained by FE analysis confirm a good agreement of the mechanical behavior of the models tested. The maximum values of the registered stressed, are of about 45 MPa (Mega Pascal) for the intact humerus and 113 MPa for the fractured one. Displacements, confirm higher values on the fractured humerus and no viable bacteria were found after microbial adhesion analyses.Conclusion: comparison between healthy and fractured humerus showed an optimal stability of the implant, when contact surfaces optimization and screws insertion are correctly performed.

Electromagnetic influence on hyperbolically symmetric sources in f(T) gravity

The present study aims to see how gravitational modification, specifically, the f(T) gravitational field, where T is torsion scalar, impacts static fluid content with hyperbolic symmetry and electromagnetic field. We enlarge Herrera’s strategy (Herrera et al. in Phys Rev D 103:024037, 2021) to analyze the impact of electromagnetic field on f(T) gravity. We distinguish the stress–energy tensor by considering the ingredients of the tetrad field in the Minkowski co-ordinate frame, commencing with modified field equations. With the advent of negative density, this sort of fluid is supposed to surpass extreme physical conditions, enabling quantum impacts to be detected. We calculate a viable formulation of mass utilizing the Tolman mass from the viewpoint of f(T) gravity along with the electromagnetic field. The gravitational interference is repulsive, as made evident by the negative value of the Tolman mass. Also, we explored the structure scalars in f(T) gravity and found significant solutions in presence of electric charge.

Poly(β-trimethylsilyloxy ester): A Degradable Polymer Based on Retro Mukaiyama Aldol Reaction.

Herein, a new type of degradable poly(β-trimethylsilyloxy ester) prepared by the organocatalyzed Mukaiyama aldol polyaddition between bis(silyl ketene acetal)s and dialdehydes is reported. Specifically, the t-Bu-P4 -catalyzed polyaddition between 1,2-bis[2-methyl-1-(trimethylsiloxy)prop-1-enyloxy]ethane (MTS2 ) and 4,4'-biphenyldicarboxaldehyde (BPDA) or butane-1,4-diyl bis(4-formylbenzoate) (BDA) can produce poly(β-trimethylsilyloxy ester)s with number-average molar mass greater than 10kg mol-1 . For the first time, it is found that these poly(β-trimethylsilyloxy ester)s are degradable in solution in the presence of nucleophiles such as fluoride and cyanide anions. It is also found that the degradation behavior of poly(β-trimethylsilyloxy ester)s is highly dependent on the nature of the used catalyst and the bond scission in polymer is fundamentally rooted in the retro Mukaiyama aldol reaction mechanism.