Electrohydrodynamic Processes and Their Affecting Parameters

Electrohydrodynamic processes such as electrospinning and electrospraying are simple, flexible, and cost-effective. Both processes use electrically charged jet of polymer solution for the fabrication of micro- or nanofibers and micro- or nanoparticle. Both of these electrodynamic techniques have been receiving increasing attention not only in the scientific community but also in industry. These fibers and particles offer several morphological and functional features that are suitable for tissue engineering in biomedical applications. The main apparatus used for both of these processes is almost the same. Both need electric voltage to induce charge on the droplet, which at optimized electric field leads to micro- or nanofibers and micro- or nanoparticles. Rayleigh in 1882, for the first time, theoretically estimated the maximum amount of charge that a liquid droplet could carry to change in a jet. This theory is now known as the “Rayleigh limit.” He predicted that a droplet on reaching Rayleigh limit would move as fine jets of liquid. More than 100 years later, Rayleigh limit theory was confirmed experimentally. Beside electric field there are other operating and solution parameters that need to be optimized before we obtain a desire product

Efficient and sustainable extraction of uranium from aquatic solution using biowaste-derived active carbon

Efficient and cost-effective biosorbents derived from biowaste are highly demanding to handle various environmental challenges, and demonstrate the remarkable synergy between sustainability and innovation. In this study, the extraction of uranium U(VI) was investigated on biowaste activated carbon (BAC) obtained by chemical activation (phosphoric acid) using Albizia Lebbeck pods as biowaste. The biowaste powder (BP), biowaste charcoal (BC) and BAC were evaluated by thermogravimetric analysis (TGA), Fourier transform infrared spectroscopy (FTIR) and Brunauer-Emmett-Teller (BET) with nitrogen adsorption for thermal properties, chemical structures, porosity and surface area, respectively. The pHPZC for acidic or basic nature of the surface and X-ray diffraction (XRD) analysis were performed for BAC. The morphological and elemental analysis were performed by scanning electron microscopy (SEM) and energy dispersive X-ray (EDX). The extraction of uranium U(VI) ions from aqueous solutions using BAC as sorbent was investigated by using different variables such as pH, contact time, initial uranium U(VI) concentration and BAC dose. The highest adsorption (90.60% was achieved at 0.5 g BAC dose, 2 h contact time, pH 6, 10 ppm initial U(VI) concentration and with 200 rpm shaking speeds. The production of this efficient adsorbent from biowaste could be a potential step forward in adsorption of uranium to meet the high demand of uranium for nuclear energy applications

Uranium resources associated with phosphoric acid production and water desalination in Saudi Arabia

Due to the rising demand for energy and the imperative to achieve net-zero carbon emissions, there is a growing focus on nuclear energy for its high efficiency as a clean energy source with minimal direct greenhouse gas emissions. The Kingdom of Saudi Arabia has set forth ambitious plans to construct multiple nuclear power plants in the near future. It is worth noting that phosphate rocks and desalination concentrate both contain relevant concentrations of naturally occurring uranium, presenting potential domestic uranium sources for the envisaged nuclear reactor fleet. This study offers a first systematic overview of the potential quantities of uranium that could theoretically be recovered during seawater desalination and phosphoric acid production in Saudi Arabia using best available technologies. It was found that in 2021 approximately 447–596 t natural uranium could have theoretically been recovered during phosphoric acid production in the Kingdom of Saudi Arabia. In addition, there were also 6.5 t uranium associated with seawater that was desalinated in 2021. If recovered the amounts would theoretically be able to provide 12%–16% (uranium from phosphoric acid) and 0.2% (uranium from seawater desalination) of the annual uranium requirements of the projected Saudi nuclear power plant fleet in 2040. As a result, we strongly recommend fostering research on unconventional uranium recovery during phosphoric acid production by promoting public-private partnerships that have the potential to develop industrial scale solutions

Facile and efficient sequestration of uranium using biomass from Saudi Arabia’s local date palms waste

Kingdom of Saudi Arabia has announced to utilize its domestic resources to enhance its future nuclear power capacity to a total of 17.6 GW by 2040. This ambitious plan is followed by mining and extraction of uranium from various approaches both physically and chemically. Therefore, an economical and efficient approach was devised for harvesting uranium content from aqueous solutions by using two bio-sorbent, i.e., date pit sawdust (DPS) and date palm biowaste (PDB). The DPS and PDB were analyzed with BET surface area, FT-IR, SEM, EDX, pHPZC and XRD techniques to examine the surface area, porosity, functional group on surface, morphology, point of zero charge of the materials and nature of materials respectively. Effect of parameters like sorbent dose, solutions pH, concentrations and time of contact on adsorption were studied in a batch method. The findings indicated that both DPS and PDB exhibited significant sequestration of U(VI) with maximum adsorption observed at 6 pH. However, PDB exhibited the maximum sorption percentage (78.80 %) and capacity (3.25 mg/g), followed by DPS (70.5 %, 2.47 mg/g, respectively), for uranium sequestration

Comparison of De-Torque and Failure Load Evaluation of Selective-Laser-Sintered CoCr, CAD-CAM ZrO, and Machined Implant Abutment/Restoration

Aim: This study aimed to compare the torque loss, fracture load, compressive strength, and failure types of selective-laser-sintered cobalt chromium (SLM-Co-Cr), computer-aided design and computer-aided manufacturing zirconium oxide (CAD-CAM-ZrO), and machined titanium (Ti) implant abutments. Methods: Thirty endosseous dental implants were vertically embedded with machined Ti (control group), CAD-CAM-ZrO, and SLM-Co-Cr abutments. Abutment fabrication involved CAD-CAM milling and SLM technology. The de-torque assessment included preload reverse torque values (RTVs), cyclic loading, and post-RTVs using a customized protocol. Fracture load assessment employed ISO-14801 standards, and statistical analysis was conducted using ANOVA and Tukey Post hoc tests (p p < 0.001). Fracture types included abutment failures in SLM-Co-Cr and machined Ti, while CAD-CAM-ZrO exhibited crown separation with deformation. Conclusion: SLM-Co-Cr-fabricated implant abutments exhibited superior stability and resistance to rotational forces, higher fracture loads, and greater compressive strength compared to CAD-CAM-ZrO and machined Ti

Effect of Alumina Contents on the Physicomechanical Properties of Alumina (Al2O3) Reinforced Polyester Composites

Polyester-based composites filled with various contents of alumina (Al2O3) (i.e., 0, 1, 5, and 10 vol%) have been fabricated in this study. Physical and mechanical properties of the composites have also been analysed. The analysis results showed that the experimental density of the polyester/alumina composites was smaller than the theoretical density, which could be attributed to the formation of voids during preparation of the composites. Meanwhile, the tensile strength, stiffness, and hardness of the composites increased with increasing alumina content, while the strain-at-break of the composites decreased. It was observed that the composites containing 5 vol% of alumina had the best tensile strength, stiffness, and hardness. The uniform distribution and dispersion of alumina particles were likely responsible for the improvement of the mechanical properties. In other hand, small decrease in tensile strength, stiffness, and hardness of composite was found in the composites with 10 vol% of alumina. The formation of agglomerates and voids was believed to be the main factor for the decrease of the both properties

Fabrication of bioactive silk composite meshes for hernia repair and guided soft tissue remodeling : in silico, in vitro and in vivo models

Objectives Post-operative complications stemming from incompatible meshes often lead to delayed wound healing, seroma, infections, inappropriate tissue infiltration and pain. The present study was outlined to develop biocompatible composite hand-knitted silk meshes modified with polymers and natural extracts. Our study introduced hand-knitted B. mori silk fibroin as the primary mesh material, offering superior mechanical strength and biocompatibility. The spin-assisted dip coating achieved desirable morphology, internal structures, thickness, and surface roughness. Moreover, the application of biopolymeric composite coatings containing polymers and natural extracts introduced antimicrobial character, facilitated cell attachment, migration, proliferation, potentiating gene expression and accelerating the process of wound healing. These composite meshes are a viable solution for addressing post-op complications in hernia and soft tissue repair surgeries. Method In this study, 9 silk-based composite meshes (modified with polymeric-extract blends through spin-assisted dip coating) were successfully developed. Experimental variants were then subjected to various characterizations including SEM, DMA and chemical analysis (FTIR and GC-MS). Modified meshes were evaluated for their physiological characteristics and biological responses (the basic criterion for the selection of composite silk mesh). The biological testing included (antimicrobial susceptibility testing, in vitro cell viability assay, cell attachment assay (NIH3T3 and hUc-MSCs), in vitro cell migration, in vitro gene expression analysis with NIH3T3, in silico molecular docking with bioactive ligands of HE extract and in vivo analysis with PHBV-HE and PHBV-Control composite meshes in rat models. Results Results showed that all variants exhibited a multi-fiber morphology with significant surface coating, allowing for optimal drug release up to 72 h. This release facilitated antibacterial properties and biocompatibility, as evidenced by in vitro cell viability, migration assays and gene expression analysis. Among the variants, the PHBV-HE composite mesh demonstrated superior results. In the case of PHBV-coated polymeric controls, the SEM analysis concluded that the presence of coating reduced the pore size up to 39.62 % whereas, fiber diameter was increased by up to 19.89 % as compared to the control. The presence of a coating on the mesh improved the mechanical strength/modulus by 165.89 %, UTS by 185.38 % and reduced the % strain by 64.67 %. The fast release of HE from PHBV-HE composite mesh was 90.7% up to 72h, confirming that it can induce antibacterial activity against surgical infections. Conclusion PHBV-HE showed the highest cell viability, wound healing and gene expression. Based on appreciable biological evaluation results shown by PHBV-HE, in rat hernia models, only the PHBV-HE variant was tested for in-vivo analysis. Results confirmed its non-toxic nature and wound-healing abilities. Enhanced cell proliferation and wound healing observed both in vitro and in vivo indicated that PHBV-HE holds promise as a biomedical implant suggesting its potential for effective hernia and soft tissue repair and regeneration

Simultaneous Evaluation of Creep Deformation and Recovery of Bulk-Fill Dental Composites Immersed in Food-Simulating Liquids

The aim of this study is to compare the creep/recovery behavior of bulk-fill dental composites after storage in various food simulating organic solvents. For this purpose, five different resin-composites (four bulk-fills and one conventional) were used. A total of 20 rectangular specimens (14 mm &times; 3 mm &times; 0.7 mm) were prepared by filling the resin-composites in Teflon mold. All of the specimens for each material (n = 5) were divided into four groups namely dry (control), distilled water (DW), artificial saliva, and absolute ethanol. The specimens were subjected to three-point bending creep test during immersion directly. A constant load of 2 N was used for each specimen with loading and unloading time 2 h each. Results: SF2 and XF showed a lower creep strain % after immersion, ranging from 0.44 (dry) to 0.75 (saliva) and 0.43 (dry) to 0.80 (ethanol), respectively. TNC BF depicts the maximum creep strain % ranging from 1.24% (dry) to 2.87% (ethanol) followed by FBF ranging from 1.17 (dry) to 2.59 (ethanol). However, the conventional material (GR) showed lower creep strain after immersion ranging from 0.28 to 0.54. Moreover, SF2 resulted in the highest creep recovery in all of the composites groups, as well as conventional material. The other composite groups showed lower creep recovery as compared to the conventional material (GR). The creep strain % for all the bulk-fill composites materials were increased during immersion in the liquids. However, for the conventional material, the creep deformation is decreased after immersion. SF2 showed the highest percentage of creep recovery among the bulk-fill composites, followed by XF

Design and Characterization of Chitosan-Based Smart Injectable Hydrogel for Improved Sustained Release of Antinarcotics

The treatment adherence of narcotics-addicted individuals with reduced incidences of relapse can be enhanced by a sustained drug release formulation of antinarcotics. So far, different drug formulations have been reported with sustained drug release periods of 28 and 35 days. To further enhance this duration, different formulations of injectable hydrogels (IHs) have been developed by combining low molecular weight (LMW) and high molecular weight (HMW) chitosan (CS) with guar gum (GG) and crosslinking them by sodium bi phosphate dibasic. The structural, morphological, and physicochemical properties of LMW-CS IH, and HMW-CS IH were evaluated using Fourier transform infrared spectroscopy (FT-IR), thermo-gravimetric analysis (TGA), scanning electron microscopy (SEM), and rheological, swelling, and biodegradation analysis. The HMW-CS IH showed high crosslinking, increased thermal stability, high mechanical strength, elevated swelling, and low biodegradation. The antinarcotic drugs naltrexone (NTX) and disulfiram (DSF) were loaded separately into the HMW-CS IH and LMW-CS IH. The release of NTX and DSF was investigated in phosphate buffer saline (PBS) and ethanol (0.3%, 0.4%, and 0.5%) over a 56-day period using an UV spectrophotometer. The drug release data were tested in zero-order, first-order, and Korsemeyer–Peppas mathematical models. In PBS, all prepared formulations followed non-Fickian drug release, while in ethanol, only NTX HMW-CS IH followed non-Fickian release in all three different concentrations of ethanol