Water splitting via photocatalysis using titanium dioxide (TiO₂) holds great potential for hydrogen gas generation. Herein, zeolitic imidazolate framework (ZIF-67) was used as a sacrificial precursor for the synthesis of cobalt oxide embedded nitrogen doped carbon (Co₃O₄@C) that was used as a co-catalyst with TiO₂ for the hydrogen generation via photocatalytic water splitting. The optimal loading of Co₃O₄@C (7 wt%) exhibited a photocatalytic hydrogen production rate (HGR) of 11,400 µmol g⁻¹ h⁻¹. It demonstrated a 75-fold and 110-fold increase for cumulative (5 h) and initial hydrogen generation rates, respectively. The electrochemical measurements such as cyclic voltammetry (CV), linear scan voltammetry (LSV), electrochemical independence spectroscopy (EIS) using Nyquist plots, and photocurrent response were conducted to evaluate the catalytic performance of Co₃O₄@C/TiO₂. Transient photocurrent response showed significant enhancement (4-fold) in photocurrent density of TiO₂. Co₃O₄@C promoted the photocatalytic performance of TiO₂ and improved the HGR. The photocatalysis using Co₃O₄@C/TiO₂ is recyclable for more than four cycles without significant loss of their performance. The results of our study may open the door for further exploration toward effective photocatalyst.

Hydrogen generation via the hydrolysis of sodium tetrahydridoborate (NaBH₄) is attractive for in situ-demand applications that require hydrogen gas as an energy source or as a reducing agent. Herein, sulfuric acid-assisted carbonization of Zr-based metal–organic frameworks (MOFs) produced a solid acid zirconium oxo sulfate/carbon (ZrOSO₄/C). X-ray diffraction, high-resolution transmission electron microscopy, energy-dispersive X-ray spectroscopy/mapping, nitrogen gas adsorption–desorption isotherm, and X-ray photoelectron spectroscopy were used to characterize the material’s phase purity and porosity. Data analysis confirmed the porosity and crystallinity of ZrOSO₄/C. The materials catalyzed the hydrolysis process of NaBH₄, producing a high hydrogen generation rate. The acidity of ZrOSO₄/C plays a vital role in the material’s catalytic performance. These observations may open a gateway for new exploration toward designing an effective catalyst for the release of hydrogen gas using hydrides.

In this study, we present a facile, one-step method for the manufacturing of all-cellulose, layered membranes containing cellulose nanocrystals (CNC), TEMPO (2,2,6,6-tetramethylpiperidine-1-oxyl radical)-mediated oxidized cellulose nanofibers (TO-CNF), or zwitterionic polymer grafted cellulose nanocrystals (CNC-g-PCysMA) as functional entities in combination with cellulose fibers and commercial grade microfibrillated cellulose. The presence of active sites such as hydroxyl, carbonyl, thioethers, and amines, gave the membranes high adsorption capacities for the metal ions Au (III), Co (II), and Fe (III), as well as the cationic organic dye methylene blue (MB). Furthermore, the membranes served as excellent metal-free catalysts for the decolorization of dyes via hydrogenation. A 3-fold increase of the hydrogenation efficiency for cationic dyes such as rhodamine B (RhB) and methylene blue was obtained in the presence of membranes compared to NaBH₄ alone. Water-based processing, the abundance of the component materials, and the multifunctional characteristics of the membranes ensure their potential as excellent candidates for water purification systems.

The comparison between crustal stress and surface strain azimuthal patterns has provided new insights into several complex tectonic settings worldwide. Here, we performed such a comparison for Egypt taking into account updated datasets of seismological and geodetic observations. In north-eastern Egypt, the stress field shows a fan-shaped azimuthal pattern with a WNW–ESE orientation on the Cairo region, which progressively rotated to NW–SE along the Gulf of Aqaba. The stress field shows a prevailing normal faulting regime, however, along the Sinai/Arabia plate boundary it coexists with a strike–slip faulting one (σ₁ ≅ σ₂ > σ₃), while on the Gulf of Suez, it is characterized by crustal extension occurring on near-orthogonal directions (σ₁ > σ₂ ≅ σ₃). On the Nile Delta, the maximum horizontal stress (S_Hmax) pattern shows scattered orientations, while on the Aswan region, it has a WNW–ESE strike with pure strike–slip features. The strain-rate field shows the largest values along the Red Sea and the Sinai/Arabia plate boundary. Crustal stretching (up to 40 nanostrain/yr) occurs on these areas with WSW–ENE and NE–SW orientations, while crustal contraction occurs on northern Nile Delta (10 nanostrain/yr) and offshore (~35 nanostrain/yr) with E–W and N–S orientations, respectively. The comparison between stress and strain orientations over the investigated area reveals that both patterns are near-parallel and driven by the same large-scale tectonic processes.

Querétaro city is situated in the north central part of the Trans-Mexican Volcanic Belt, and it was considered by several previous studies as an aseismic region. Since that, as well as considering the surrounding seismotectonic setting, it was significant to assess the seismic hazard across the city which aids in the development and updating the building codes and the seismic design criteria. In this regard, the Horizontal to Vertical Spectral Ratio (HVSR) Nakamura's technique has been applied to investigate the local-site effects across the city. Microtremor measurements were performed at 76 free-field selected sites, through the implementation of portable seismic stations equipped with three-component velocity sensors of Trillium Compact 120 s broadband seismometer. Then, acceleration values were estimated by generating synthetic accelerograms based on a recently-developed algorithm that combines the HVSR technique and the theory of random vibrations, considering as a reference the September 19, 2017 (Mw 7.1) intraslab earthquake recorded at the Centro de Geociencias (CGEO) Seismic Station, in Juriquilla, Querétaro. Finally, by computing the pseudoacceleration response spectra through the linear acceleration method at structural periods of 0.1, 0.5, 1.0, 2.0, and 5.0 s, corresponding seismic hazard maps were established for the studied region. Based on these values and delimiting the areas with higher risk considering the interaction of the soil with the buildings on it, this article is the basis for delimiting seismic parameters that define the city, with future applications in the seismic engineering considering both linear and nonlinear structural behaviors.

The synthesis of 5-acetyl-6-methyl-4-(1, 3-diphenyl-1H-pyrazol-4-yl)-3, 4-dihydropyrmidin-2 (1H)-thione was achieved by one-pot three-component synthesis using CaCl 2 in refluxing EtOH. The starting compound was utilized to synthesize a new series of 5-pyrazolyl; isoxazolyl; pyrimidinyl derivatives via the synthesized chalcone. Also, fused isoxazolo [5, 4-d] pyrimidine and pyrazolo [3, 4-d] pyrimidine were obtained by the treatment of 5-acetyl derivative with hydroxyl amine and/or hydrazine hydrate. Also, the thiosemicarbazide derivative was prepared and utilized to synthesize other new thiazole derivatives. The structures of all compounds have been established on the basis of their analytical and spectral data. All compounds was also evaluated for their antibacterial and antifungal activity against various strains of bacteria and fungi. Also, the anti-inflammatory activity of some of synthesized compounds was …