Additive Manufacturing is a relatively new technology that allows to produce intricate parts with geometries that cannot be achieved through conventional manufacturing methods. One of the most widespread methods of 3D printing is Fused Filament Fabrication (FFF). In this study different 3D-printed, bone-shaped specimens made out of ABS (acrilonitrile-butadiene-styrene) are tested, complying with norms for mechanical testing of polymeric materials, with variations on its printing parameters (percentage of infill density), shape (thickness of specimen), and an annealing heat treatment. The resistance to tension is measured, and compared. The stress-strain curves were gathered from the universal tension tester from each of the specimens. Finally a statistical method is used in order to correlate the obtained behavior with a function that predicts the tensile strength of the part based on the parameter that can be varied, whether or not the heat treatment has a meaningful effect on the part that is to be produced, and if a lesser ratio of cross-sectional area to volume has a negative effect on the tensile properties. The resulting models showed a more pronounced decrease of tensile strength as the infill density is reduced, as well as a measurable and positive impact of the heat treatment on the ultimate tensile strength of the specimens. Finally the change in ratio of area to volume doesn't conclusively show a difference in tensile strength.

The citrate–nitrate method was employed to synthesize the magnesium chromite (MgCr₂O₄) spinel, followed by calcination at 700℃ for 3hours. The synthesized compound was analyzed using techniques including powder XRD, SEM-EDAX, FTIR, UV-DRS and LCR Meter. The structural analysis was carried out using X-ray diffraction, which revealed the formation of the cubic crystal symmetry of the sample with the corresponding Fd-3 m space group. The average particle size of the sample was calculated around 13.26nm. Further, the diffraction pattern was refined by Fullprof Software which validated the single phase cubic structure formation. Using tetrahedral and octahedral positions, the lattice vibrations of the associated chemical bonds were identified using Fourier transform infrared (FTIR) spectroscopy. SEM (Scanning electron microscopy) micrographs showed the spherical nature of the particles and the constituent particles were between 10 and 40 nm in size. The optical bandgap value was evaluated using the Tauc’s plot. Pellets of the powdered sample were prepared for determining the dielectric aspects including dielectric constant (ε’), tangent loss (tanδ and ac conductivity (σ_ac) in the frequency range of 100Hz–4MHz, at room temperature. The charge transport mechanism was explored from the complex impedance spectroscopy study. The obtained results indicate that magnesium chromite may be a potential candidate in the fabrication of sensors, micro-electronic devices, and other electronic equipment.

This study introduces an experimental approach for quantifying audible acoustic frequency parameters within a rigid porous medium using an impedance tube. Employing the equivalent fluid model, a derivative of Biot's theory, we explore wave propagation intricacies within porous materials, emphasizing the pivotal roles of the effective density and dynamic compressibility of the saturated fluid. Our primary focus is on resolving the inverse problem, seeking to minimize both experimental and theoretical absorption coefficient expressions across the audible frequency range. Simultaneously, we identify and determine four critical parameters: viscous and thermal permeability, the inertia factor introduced by Norris, and the thermal tortuosity introduced by Lafarge. The research results encompass a thorough comparative analysis involving experimental and simulated absorption coefficients. This examination utilizes optimized parameters and spans across four diverse polyurethane foam samples. Through this comprehensive investigation, we elucidate the nuanced interplay between experimental observations and theoretical predictions. The findings not only advance our understanding of the intricate acoustic characteristics of rigid porous media but also contribute valuable insights into optimizing absorption coefficients and the broader field of wave propagation within such materials. This work stands at the intersection of experimental acoustics, porous media physics, and inverse problem-solving, providing a nuanced exploration of audible frequency phenomena.

Blending wheat with fava bean and black cumin flours can improve the nutritional content of wheat-based bread. The current study investigated the effects of flour blending ratios of wheat, germinated fava bean, and black cumin on the physicochemical and sensory attributes of bread. A total of sixteen bread formulations were produced using Design Expert software: mixtures of wheat (64–100%), fava bean (0–30%), and black cumin (0–6%). The findings showed that the mixed fraction of composite flours affected the sensory attributes and nutritional value of bread. The mineral contents [Fe, Zn, and Ca] and proximate compositions [ash, fiber, fat, and crude protein] increased with an increase in fava bean and black cumin flour content and decreased with an increase in wheat flour content. The carbohydrate content and crumb lightness (L* value) increased with a decrease in black-cumin and germinated fava bean flour proportion. The sensory attributes were significantly affected by the blend proportion (p < 0.05). Sensory scores increased with an increase in the level of germinated fava bean flour and decreased with an increase in the level of black cumin. Generally, the best bread blending ratio was found to be 72.5% wheat, 25.6% germinated fava bean, and 1.9% black cumin, in terms of overall qualitative attributes. This could lead to healthier and more appealing bread options.

Recent developments in additive manufacturing have resulted in a reduction in the costs and the level of complexity connected with the manufacturing of conformal cooling channels (CCCs). Conformal cooling channels, also known as CCCs, offer a higher level of cooling efficiency in the injection molding process when compared to the more traditional straight-drilled channels. The fundamental reason for this is that traditional machining processes do not have the potential to properly follow the contours of the molded form. However, CCCs are able to offer this capability. Using CCCs makes it possible to improve cycle times, achieve a more uniform temperature distribution, and reduce thermal strains and warpage. When it comes to developing a design that is both productive and cost-effective, computer-aided engineering (CAE) simulations are an absolute necessity nowadays. The primary purpose is to determine the optimum placements of CCCs, to improve temperature uniformity and reduce the amount of time that ejections take place (ejection duration). For the sake of future optimization techniques, it is possible to infer the practicability and potential usefulness of the design variables and parametrization that were accomplished in ANSYS Parametric Design Language (APDL). In fact, all the considered geometric/design variables present significant sensitivity in the studied CAE model.

Introduction

Sodium alginate nanocomposites containing metallic nanoparticles have found various biomedical and environmental applications. These materials are easy to prepare and sustainable. In recent years, such materials have been widely used for the adsorption/degradation of toxic substances such as organic dyes, pharmaceuticals, heavy metals, etc. In this project, we have developed reusable sodium alginate–poly sodium acrylate silver nanocomposites with a high swelling capacity for enhanced degradation of toxic organic materials.

Methodology

Polymer beads based on sodium alginate–poly sodium acrylate containing silver nanoparticles were synthesized by means of a combination of ionotropic crosslinking in calcium chloride solution and free-radical polymerization using ammonium persulfate. The beads were characterized using various advanced methods such as UV-Vis absorption spectroscopy, Fourier transform infra-red spectroscopy, and electron microscopy. The swelling capacity was evaluated using the gravimetric method. The antibacterial property was studied using the incubation method against three clinically important pathogens: Escherichia coli, Staphylococcus aureus, and Pseudomonas aeruginosa. The catalytic degradation of Congo red and 2-nitrophenol achieved by the beads was studied in the presence of sodium borohydride.

Preliminary results

The nanocomposite beads were spherical and porous and exhibited a high swelling capacity due to the presence of poly sodium acrylate. A strong plasmon resonance (SPR) peak at around 400 nm confirmed the presence of silver nanoparticles. The nanocomposites were effective against the growth of E. coli and P. aeruginosa. Almost 100% degradation of Congo red and 2-nitrophenol was achieved in about 30 min.

Conclusion and work in progress

The nanocomposite beads showed both antibacterial and catalytic properties, showing promise for detoxification of hospital wastewater in the future. The reusability of the material and the use of real-life samples are currently in progress.

Recent international tournaments have seen various changes in the design of official footballs. Especially since the 2006 Germany World Cup, the balls used in World Cups and Euro Championships have continuously evolved in terms of surface roughness and other characteristics. This study compares the flight characteristics of the footballs used in Euro 2024 and the 2022 Qatar World Cup footballs.

A wind tunnel experiment was conducted comparing the drag force characteristics of the footballs used in the 2022 Qatar World Cup (Al Rihla) and Euro 2024 (Fussballliebe). Drag force was measured using a sting-type balance detector, which is capable of detecting drag force accurately.

Comparing the subcritical drag coefficients (Recrit) of each football, the 2022 World Cup ball exhibited approximately 0.17 (at Re=2.2×10^5), while the Euro 2024 ball showed about 0.19 (at Re=1.9×10^5). Based on these findings, simulations were conducted to calculate the respective distances when kicked at an initial velocity of 30 m/s and an angle of 25 degrees. The results showed that the 2022 World Cup ball traveled approximately 46.5 meters, whereas the Euro 2024 ball traveled a shorter distance of 45.1 meters. Additionally, when each ball was kicked from 25 meters away with an initial velocity of 30 m/s and an angle of 12 degrees, the landing point in front of a goalpost was lower for the Euro 2024 ball (0.82 meters) compared to the 2022 Qatar World Cup ball (0.91 meters).

Consequently, in football tournaments where balls vary between competitions, it has become crucial for players to quickly adapt to the specific characteristics of each ball. This adaptability directly impacts performance, highlighting the significant importance of understanding and adjusting to the unique properties of tournament-specific footballs.

Subcritical water extraction (SWE) is a green technology with interesting advantages, including a cheap and selective process for various applications, including the extraction of bioactive compounds. However, knowledge and data on upscaling from studies related to this process are limited. Therefore, this study reports comparative experimental data for the upscaling process of subcritical water extraction. Two SWE processes with different scales, namely the commercially available high-pressure system ASE 200 with a capacity of 28 ml and a locally fabricated high-volume SWE process with a capacity of 1000 ml, were employed for the extraction of medicinal compounds from Zingiber officinale, namely 6-gingerol and 6-shogaol. The effect of temperature for both setups on the compounds' concentrations was studied from 130°C to 200°C at a constant pressure of 3.5 MPa and for a duration of 30 minutes. The quantitative analysis for each compound was performed using High-Performance Liquid Chromatography (HPLC). The optimum temperature for the extraction of 6-gingerol using the high-volume SWE was 130°C, with a concentration of 1741.54 ± 0.96 µg/g, which differs from ASE 200, in which the optimum extraction temperature for 6-gingerol was 140°C, with a concentration of 1957.22 ± 2.55 µg/g. Meanwhile, for the extraction of 6-shogaol, both pieces of equipment recorded the same optimal temperature—170°C—with concentrations of 541.78 ± 3.16 µg/g and 1135.23 ± 1.18 µg/g for high-volume SWE and ASE 200, respectively. This is possibly due to the difference in the scale of the extraction process, which was up to 35-fold, from a 28 ml to a 1000 ml capacity, consequently affecting the heat and mass transfer processes during extraction. Thus, scale-up factors need to be considered for effective design during the scaling up of the SWE process to obtain higher mass transfer efficiency.

The load resisting capacity of reinforced-concrete (RC) structures reduces due to various sources such as earthquakes, corrosion and aging effects. Even under neutral circumstances, the performance of buildings can be reduced over time due to the strength and deformation degradation of concrete and steel. Reconstruction of such structures may be an option, but it may cause significant costs, labor and time. Therefore, depending on the priority of the structure, strengthening becomes one of the alternatives and may be a sustainable solution to increase the capacity in terms of both strength and ductility.

There have been many studies on the strengthening of buildings and the different methods that have been improved and applied. Among these strengthening methods, RC jacketing is considered one of the most common methods in over the world. The advantage of this method is that it needs little labor and equipment, with low costs, and method itself can improve the strength, stiffness and, to some degree,ductility of structural elements by increasing the cross-section andlateral confinement, thus increasing the performance and service life.

Based on the above, this study examines the behavior of different cross-sections' strength with RC jacketing. Using the improved jacketing behavior models in the experimental studies, the mechanical behavior of RC jacketing was investigated using three different reinforced-concrete square sections with varying jacketing thicknesses. The axial load ratio of a column before strengthening was taken as 30%, and the longitudinal reinforcement ratio of the jacketed and as-built sections was assumed to be 1%. The compressive strength of the existing column and RC jacket was 15MPa and 40MPa, respectively. The changes in the strength and ductility of the sections were evaluated using parameters such as ratio of jacket thickness to cross-section depth (Δ/h) and ratio of cross-sectional area to area of jacketed RC section (A1/A2). The evaluations revealed a strong relationship between these parameters and the section responses.

The separation of Butadiene 1,3 from pyrolysis products is a critical step in the petrochemical industry, as Butadiene is a key raw material for producing synthetic rubber and other polymers. This study presents a detailed model-based analysis of the separation process, focusing on optimizing operational parameters to maximize butadiene recovery, enhance product purity, and reduce energy consumption. The simulation was conducted using Aspen Plus, evaluating critical variables such as the solvent-to-feed ratio, reflux ratio, number of column stages, and energy integration between distillation units.
The simulation results indicated that an optimal solvent-to-feed ratio of 1.5:1 and a reflux ratio of 4.2:1 in the extractive distillation column provided the highest separation efficiency. Under these conditions, the recovery rate of Butadiene 1,3 reached 98%, with a final product purity of 99.5%. Furthermore, this study revealed that increasing the number of theoretical stages in the distillation column improved the separation process without significantly increasing energy demand. Energy integration between the primary distillation and extractive distillation columns led to a 12% reduction in total energy consumption.
These findings demonstrate the importance of fine-tuning operational parameters to achieve high separation efficiency and product quality while minimizing energy use. This model-based analysis provides valuable insights into the design and optimization of industrial-scale butadiene separation processes, offering strategies to reduce operational costs and improve sustainability in production. The methodology and results can serve as a basis for further improvements in similar separation processes across the petrochemical industry.