bluuebunny/crossref_metadata_2025 huggingface dataset:
Tensile Properties of Ex-Situ Ti-TiC Metal Matrix Composites Manufactured by Laser Powder Bed Fusion
Authors: Bernard Gaëtan , Pejchal Vaclav , Sereda Olha , Logé Roland E.
Published: November 2024

Titanium-based Metal Matrix Composites (MMCs) manufactured by additive manufacturing offer tremendous lightweighting opportunities. However, processing the high reinforcement contents needed to substantially improve elastic modulus while conserving significant ductility remains a challenge. Ti-TiC MMCs fabricated in this study reported fracture strains in tension up to 1.7% for a Young’s modulus of 149 GPa. This fracture strain is 30% higher than the previously reported values for Ti-based MMCs produced by Laser Powder Bed Fusion (LPBF) displaying similar Young’s moduli. The heat treatment used after the LPBF process leads to the doubling of the fracture strain thanks to the conversion of TiCx dendrites into equiaxed TiCx grains. The as-built microstructure shows both un-dissolved TiC particles and sub-stoichiometric TiC dendrites resulting from the partial dissolution of TiC particles. The reduction of the C/Ti ratio in TiC during the process results in an increase in the reinforcement content, from a nominal 12 vol% to an effective 21.5 vol%. The variation of the TiC lattice constant with its stoichiometry is measured, and an empirical expression is proposed for its effect on TiC’s Young’s modulus. The lower TiC powder size distribution displayed higher mechanical properties thanks to a reduced number of intrinsic flaws.
Vitrified Clay for the Production of a Green Sustainable Ultra-High-Performance Fiber-Reinforced Concrete
Authors: Muñoz-Espinoza Ana Luisa , López-Yépez Lucio Guillermo , Valdez-Aguilar José Abelardo , Juarez-Alvarado César Antonio , Durán-Herrera Alejandro
Published: November 2024

As awareness of the impact of anthropogenic activities on climate change increases, the concepts of durability, resilience, and sustainability in concrete tend to be adopted more seriously in the concrete construction industry. In this sense, one of the concrete technologies that began in the 1980s and that significantly contributes to maximize the beneficial effect on all these concepts are the ultra-high-performance concretes, a very attractive technology because it presents ultra-high strength and durability performances far superior to those of conventional concretes, a performance that is leading to a permanent increased demand. However, the development of these concretes has been widely criticized due to their high ecological impact, which is mainly attributable to the high cement dosages required for their production (800–1000 kg/m3). To address this criticism in a comprehensive manner and thereby reduce the embodied carbon attributable exclusively to the material, this research was oriented to determine the effect of an industrial by-product of vitrified clay, as a partial or total substitution for cement, silica fume, and limestone aggregate, on the compressive strength, flexural toughness, and embodied CO2. For the UHPC’s evaluated in this work with a dosage of 2% by volume of steel micro-fibers, the results evidence the feasibility that the following substitutions by mass: 30% of the Portland cement, 100% of the silica fume, and 30% of the limestone aggregate and powder, do not detract the fresh stage, the compressive strength, the static modulus of elasticity, and the flexural strength, leading to significant reductions of the embodied CO2.
Analysis of Mechanical Properties and Printing Orientation Influence of Composite Resin for 3D Printing Compared to Conventional Resin
Authors: Araújo Leonardo V. , de Siqueira Fabiana S. Figuerêdo , de Macedo Rayssa F. Cavaleiro , Gomes Felipe S. , Castro Gustavo G. , Dibai Daniela B. , Maia Filho Etevaldo M. , Tavarez Rudys R. J.
Published: November 2024

This study aimed to compare the flexural strength, surface roughness, and microhardness of a resin for three-dimensional (3D) printing and a conventional composite resin and to evaluate whether the printing orientation influences these properties. To evaluate the flexural resistance, test specimens were produced and divided into four groups: three groups of resins for 3D printing with inclinations of 0°, 45°, and 90° and one group of conventional composite resin. Forty discs were produced and subjected to a sandpaper-polishing sequence, and the surface roughness was measured using a roughness meter. The Vickers microhardness (HV) test was performed at three different points, and the average was obtained. The results were subjected to ANOVA statistical analysis and Tukey’s test. There were statistical differences in the flexural strength and microhardness between the conventional resin and the resin used for 3D printing. No statistical difference in surface roughness was observed. The resin for 3D printing exhibited lower flexural strength and microhardness than conventional composite resins. We concluded that the resin for 3D printing had lower flexural strength and HV than the conventional composite resin but similar surface roughness. The printing orientation did not affect the flexural strength, whereas the hardness increased as the printing angle increased.
Preparation of an FA-Based Discoloration Material and Its Application in Jewelry Design
Authors: Zhang Xiaomin , Gao Xiangrui , Yuan Yue , Yang Guangqin , Li Yanchen
Published: November 2024

Fly ash (FA) is the main solid waste emitted from coal-fired power plants. Due to its high yield, low utilization rate, and occupation of a large amount of land, it exerts enormous pressure on the Earth’s environment. With the deepening of the concept of sustainable development, exploring the reuse of industrial waste such as FA has become a key strategy. If FA can be combined with commonly used jewelry in people’s lives, it will be of great significance to promote the high-net-worth utilization of FA. Therefore, this study synthesized a fly-ash-based composite material with color-changing function and combined it with necklaces as the main material. In the first stage, after blending fly ash and slag, an alkaline activator with a total mass of 10% was added. When the proportion of fly ash was 60%, the compressive strength of the prepared fly-ash-based composite material reached 10.1 MPa. This was attributed to the reaction between sodium silicate in the alkaline activator and free CaO, MgO, and other substances in the fly ash to form hydrated silicate colloids, which solidify the fly ash and transform it into a complex three-dimensional network skeleton. In the second stage, a UV resistant coating with thermochromic function was obtained by blending acrylic resin, TiO2, and a thermosensitive color-changing agent. It was applied to the surface of fly-ash-based composite materials, and the results showed that as the content of the color-changing agent increased, the number of pores on the surface of the coating gradually decreased. When the content of color-changing agent was 10%, the prepared 10%FAB not only had good surface color but also had good thermal stability, UV absorption ability, superhydrophobicity, and mechanical properties. Therefore, 10%FAB was selected as the basic material for jewelry design. In the third stage, the traditional Chinese technique of “gold inlaid with jade” was utilized to develop jewelry applications for the FA composites. As such, 10%FAB was processed into necklaces, which not only had modern design aesthetics but also had good color-changing effects above 30 °C. And after a long period of UV aging experiments, the necklace did not show any wrinkles, bubbles, or other phenomena. Due to the excitation of TiO2 hole–electron pairs, the necklace’s UV absorption ability was further improved. This study demonstrates the potential application of industrial waste in decorative products, expands the high-end utilization of fly ash as a low-cost material, and provides new ideas for building a low-carbon lifestyle.
Self-Reinforced Composite Materials: Frictional Analysis and Its Implications for Prosthetic Socket Design
Authors: Nagarajan Yogeshvaran R. , Hewavidana Yasasween , Demirci Emrah , Sun Yong , Farukh Farukh , Kandan Karthikeyan
Published: November 2024

Friction and wear characteristics play a critical role in the functionality and durability of prosthetic sockets, which are essential components in lower-limb prostheses. Traditionally, these sockets are manufactured from bulk polymers or composite materials reinforced with advanced carbon, glass, and Kevlar fibres. However, issues of accessibility, affordability, and sustainability remain, particularly in less-resourced regions. This study investigates the potential of self-reinforced polymer composites (SRPCs), including poly-lactic acid (PLA), polyethylene terephthalate (PET), glass fibre (GF), and carbon fibre (CF), as sustainable alternatives for socket manufacturing. The tribological behaviour of these self-reinforced polymers (SrPs) was evaluated through experimental friction tests, comparing their performance to commonly used materials like high-density polyethylene (HDPE) and polypropylene (PP). Under varying loads and rotational speeds, HDPE and PP exhibited lower coefficients of friction (COF) compared to SrPLA, SrPET, SrGF, and SrCF. SrPLA recorded the highest average COF of 0.45 at 5 N and 240 rpm, while SrPET demonstrated the lowest COF of 0.15 under the same conditions. Microscopic analysis revealed significant variations in wear depth, with SrPLA showing the most profound wear, followed by SrCF, SrGF, and SrPET. In all cases, debris from the reinforcement adhered to the steel ball surface, influencing the COF. While these findings are based on friction tests against steel, they provide valuable insights into the durability and wear resistance of SRPCs, a crucial consideration for socket applications. This study highlights the importance of tribological analysis for optimising prosthetic socket design, contributing to enhanced functionality and comfort for amputees. Further research, including friction testing with skin-contact scenarios, is necessary to fully understand the implications of these materials in real-world prosthetic applications.
In Vivo Study of Organ and Tissue Stability According to the Types of Bioresorbable Bone Screws
Authors: Kwon Tae-Young , Lee Geum-Hwa , Lee Hyuk , Lee Kwang-Bok
Published: November 2024

Biodegradable material, such as magnesium alloy or polylactic acid (PLA), is a promising candidate for orthopedic surgery. The alloying of metals and the addition of rare earths to increase mechanical strength are still questionable in terms of biosafety as absorbent materials. Therefore, the purpose of this study is to understand the effect of substances due to the degradation of various biodegradable substances on organs in the body or surrounding tissues. A total of eighty male Sprague−Dawley rats were selected for this study, and the animals were divided into four groups. Each of the three experimental groups was implanted with magnesium alloy, polymer, and titanium implants; the control group only drilled into the cortical bone. Serum assay, micro-CT, hematoxylin and eosin staining, immunoblotting, and real-time PCR were evaluated. There was no significant difference between the two groups of magnesium alloy and polymer in serum assay, but micro-CT analysis confirmed that magnesium alloy degrades faster than polymer, and histological examination showed a strong inflammatory response in the early stages, which was similarly observed in immunoblotting and real-time PCR. Our findings show that there was no toxicity due to the degradation of the biodegradable material, and the difference in each inflammatory response is thought to be determined by the rate of degradation in the body.
Identification of Deformation Effects While Shaping the Material Surface Relief Due to Burnishing Treatment
Authors: Zaborski Andrzej , Rogólski Robert , Grzywiński Stanisław
Published: November 2024

This study analyses a set of phenomena occurring in the burnished surface layer at the initial moment of deformation formation. The aim of the present research was to explain the phenomena occurring in the top layer of the material during burnishing. The presented analyses include selected laboratory and experimental studies of the process involved in forming burnished surface layers. As shown, conducting an analysis of these processes is purposeful and important because the processes affecting final deformations determine the definitive properties of the burnished surface layers. The final results should help to increase the durability and smoothness of the surface of the products obtained. The feasibility of applying computer technology to determine the three-dimensional shape of the deformation zone formation based on measurements of the stereometry of the contact zone of the burnishing tool with the workpiece material is presented. The process of forming a deformation zone was analysed, revealing that irregularities left over from prior treatment are permanently deformed, and a new structure of irregularities is formed on the machined surface, conditioned by the mechanical, geometric, and kinematic factors of the process. Crucial to this are qualities such as the burnishing load (pressure), the type, shape, and dimensions of the tool, the properties of the workpiece material, and the roughness of the surface before burnishing. The analyses presented here include the first stage of processing, in which initial contact is made with the workpiece, and the period of actual processing, during which plastic deformation of the material occurs in three perpendicular directions, leading to the formation of a material wave on the machined surface just in front of the burnishing tool.
The Influence of Mechanical Properties of Laser-Melted Tungsten Carbide Composite with Nickel/Cobalt Ingredients
Authors: Wang Xiao-Dong , Jean Ming-Der
Published: November 2024

This study used statistical tools to optimise WC/Co/Ni welds and model construction to improve the mechanical properties of coatings by laser cladding. The effect of the parameters on the wear performance of the weld was determined by analysis of variance. In addition, a polynomial model was constructed using the response surface method based on the experimental data of the orthogonal array designed by Taguchi. The experimental results show that there are white initial precipitation carbides and grey areas of WC mixed with Co and Ni compounds, while less wear and less plastic deformation are observed with WC/Co/Ni alloys. By adding Co/Ni alloys, the composite coating extension is seen to have good anti-wear performance. Based on the regression model, a pairwise interaction model was successfully constructed and further modelling of the 3D contour of the wear behaviour was explored. Comparing all the experiments, the predictions of the interaction model were found to be reliable, with an average error of 8.75%. The findings show that there is a very close match between the predicted values of RSM for wear performance and the experimental data, which proves the effectiveness of the Taguchi design-based RSM in improving the mechanical properties of laser cladding.
Effect of Variations in Aggregate Ratios on the Fresh, Hardened, and Durability Properties of Self-Compacting Concrete
Authors: Kaya Yahya , Beytekin Hatice Elif , Mardani Ali
Published: November 2024

Self-compacting concrete (SCC) is a type of concrete that can be poured into complex geometries and dense reinforcement areas without the need for mechanical vibration, exhibiting excellent segregation resistance and flowability. Its adoption in the construction industry has surged in recent years due to its environmental, technical, and economic advantages, including reduced construction time and minimized occupational hazards. The performance of SCC is significantly influenced by the properties of the aggregates used. This study investigates the effects of variations in the coarse-to-fine aggregate ratio and water/binder (w/b) ratio on the fresh, hardened, and durability properties of SCC. A total of eight different SCC mixtures were prepared, utilizing two distinct s/b ratios and four varying fine-to-coarse aggregate ratios. The results indicated that increasing the s/b ratio enhanced fresh state performance but adversely affected mechanical strength and shrinkage behavior. Furthermore, the need for admixture and flow times improved with increasing coarse aggregate content, attributed to the reduction in cohesiveness and viscosity. However, this change did not significantly impact mechanical properties, while high-temperature resistance and shrinkage exhibited an upward trend.
Effect of Graphene Aerosol Doped with Hypochlorous Acid, Curcumin, and Silver Nanoparticles on Selected Structural and Biological Properties
Authors: Sowińska Aleksandra , Lange Agata , Kutwin Marta , Jaworski Sławomir , Skrzeczanowski Wojciech , Bombalska Aneta , Romiszewska Anna , Olkowicz Klaudia , Bogdanowicz Zdzisław , Nasiłowska Barbara
Published: November 2024

This paper presents the results of studies on the effects of four types of aerosols containing an aqueous dispersed suspension of graphene oxide (GO) and an aqueous dispersed suspension of graphene oxide with the addition of curcumin (GO + C), silver nanoparticles (GO + Ag), and hypochlorous acid (GO + HClO) on selected structural and biological properties. Structural studies were carried out using electron microscopy, including a scanning electron microscope (SEM), scanning transmission electron microscopy (STEM), laser emission spectroscopy (LIBS), and absorption spectra in the infrared range attuned total reflectance (FTIR-ATR). The growth inhibition zone and viability of Staphylococcus aureus and Pseudomonas aeruginosa bacteria were studied. Studies have shown that the addition of silver nanoparticles and hypochlorous acid to the nanostructures of graphene oxide suspension improves bactericidal properties. In addition, it was observed that the application of a dispersed graphene oxide suspension in the form of an aerosol enriched with hypochlorous acid and silver nanoparticles results in the formation of a fairly uniform layer of graphene flakes, characterized by the presence of admixtures used.
An Investigation of the Metal Powder Ultrasound Atomisation Process of 316L Stainless Steel
Authors: Bałasz Błażej , Żurawski Łukasz , Laskowska Dorota , Muts Nataliya , Ivanushko Andriana
Published: November 2024

This paper presents the results of a study on the atomisation process of 316L material. The primary objective of the study was to obtain the highest quality, quantity and yield of 316L metal powder for the established atomisation parameters (torch current and wire feed speed) at the assumed process time. Using experiment planning according to the Taguchi method, 16 pairs of controllable variable parameters were developed. It was observed that the low current high-wire speed configuration resulted in the formation of a considerable amount of molten metal on the sonotrode platform. This phenomenon prevented the ultrasound system from working properly, so some of the processes were interrupted. The results obtained from the tests showed that torch current and wire feed speed are parameters that have a significant impact on the efficiency of the ultrasonic atomisation process. The highest efficiency was achieved by the process with a torch current of 100 A and a wire feed speed of 9 mm/s.
The Effect of the Pyrolysis Temperature of a Leather–Textile Mixture from Post-Consumer Footwear on the Composition and Structure of Carbonised Materials
Authors: Kowalik-Klimczak Anna , Łożyńska Monika , Życki Maciej , Woźniak Bogusław
Published: November 2024

This paper presents an investigation into the use of pyrolysis to valorise solid waste in the form of post-consumer footwear uppers. A heterogenous leather and textile mixture is studied, produced by crushing some representative samples of post-consumer footwear uppers. The waste has a low ash content and a high net calorific value, which translates into the high gross calorific value of the material. In addition, it contains relatively little S and Cl, which is promising for its use in the process of pyrolysis. The effect of the pyrolysis temperature on the efficiency of carbonising leather and textile mixtures, their physico-chemical parameters, elemental composition, and structure, as well as the development of a specific surface, is investigated. The research results imply that as the pyrolysis temperature grows, the carbonisation efficiency declines. The produced materials consist primarily of C, O, N, and H, whose contents depend on the pyrolysis temperature. Moreover, all the carbonised materials display the presence of two G and D bands, which is typical for carbon materials. Based on the peak intensities of the bands, ID/IG coefficients are calculated to assess the organisation of the materials’ structures. As the pyrolysis temperature rises, the structural organisation declines, contributing to an increased material porosity and, thus, a greater specific surface of the carbonised materials. This study contributes data on the thermal management and pyrolysis of leather and textile waste into useful carbonised materials. Investigating the applicability of carbonised materials is projected as the next stage of research work.
Wear Resistance Design of Laser Cladding Ni-Based Self-Fluxing Alloy Coating Using Machine Learning
Authors: Fu Jiabo , Yang Quanling , Devojno Oleg , Kardapolava Marharyta , Kasiakova Iryna , Wang Chenchong
Published: November 2024

To improve the collaborative design of laser cladding Ni-based self-fluxing alloy (SFA) wear-resistant coatings, machine learning methods were applied. A comprehensive database was constructed from the literature, linking alloy composition, processing parameters, testing conditions, and the wear properties of Ni-based SFA coatings. Feature correlation analysis using Pearson’s correlation coefficient and feature importance assessment via the random forest (RF) model highlighted the significant impact of C and B elements. The predictive performance of five classical machine learning algorithms was evaluated using metrics such as the squared correlation coefficient (R²) and mean absolute error (MAE). The RF model, which exhibited the best overall performance, was further combined with a genetic algorithm (GA) to optimize both composition and processing parameters collaboratively. This integrated RF-GA optimization system significantly enhanced efficiency and successfully designed multiple composition and process plans. The optimized alloy demonstrated superior wear resistance with an average friction coefficient of only 0.34, attributed to an enhanced solid solution strengthening effect (110 MPa) and increased hard phase content (52%), such as Ni₃Si, CrB, and NbC. These results provide valuable methodological insights and theoretical support for the preparation of laser cladding coatings and enable efficient process optimization for other laser processing applications.
A Deep Learning Model for Estimating the Quality of Bimetallic Tracks Obtained by Laser Powder-Directed Energy Deposition
Authors: Wong Vincent , Aversa Alberta , Rodrigues Alessandro Roger
Published: November 2024

During the fabrication of Inconel 718–AISI 316L bimetallic components via laser powder-directed energy deposition, understanding the relationships between processes, microstructures, and material properties is crucial to obtaining high-quality parts. Physical–chemical properties, cooling rates, and thermal expansion coefficients of each material may affect the microstructure of parts, generating segregations and cracks. This paper analyzes how the process parameters affect the dimensions, chemical composition, and microhardness of bimetallic tracks. We created a dataset that included laser power, powder feed rate, material, skeletal density, dimensional features, chemical composition, and microhardness. Then, a deep learning methodology using a multilayer perceptron was used to estimate the relationship between these factors. The architecture comprised four inputs in the input layer and five hidden layers with 20, 40, 30, 30, and 30 neurons, respectively. This architecture was used to estimate the dimensional features, chemical composition, and microhardness. The model precision was evaluated using the determination coefficient (R2) and the mean absolute error (MAE) function. Lastly, we used a random forest classifier to select the bead quality from the optimal process parameters. The results showed a significant decrease in training loss and validation loss between 50 and 100 epochs. This decreasing trend continued until 350 epochs. This paper contributes to understanding the relationships between process–structure properties in the bimetallic tracks of Inconel 718 and AISI 316L.
Low-Acid Leaching for Preferential Lithium Extraction and Preparation of Lithium Carbonate from Rare Earth Molten Salt Electrolytic Slag
Authors: Chen Zaoming , Peng Ruzhen , Xiang Zhen , Liu Fupeng , Wang Jinliang , Chen Xirong
Published: November 2024

In this work, lithium was preferentially recovered through the low-acid leaching from rare earth molten salt electrolytic slag (REMSES) with a leaching temperature of 60 °C. The influence on lithium extraction was investigated in detail in different leaching conditions. The optimal conditions were as follows: liquid-to-solid ratio (10 mL/g), sulfuric acid concentration (0.8 mol/L), leaching time (60 min) and leaching temperature (60 °C). This yielded a lithium extraction rate of 98.52% and a lithium carbonate purity of 99.5%. It was fitted using an empirical model; the kinetics showed that internal diffusion control conformed to the low-acid leaching reaction, which had an apparent activation energy of 10.81 kJ/mol for lithium. The total profit from the whole process was USD 0.2576 when dealing with 1.0 kg of REMSES. Moreover, in the sulfuric acid system, the leaching reaction mechanism was carefully investigated between 30 and 90 °C. An innovative process of recovering lithium from REMSES was achieved with environmental friendliness and good economic returns. Compared to traditional leaching using concentrated sulfuric acid, this cleaner recycling method conforms to the concept of green, low-carbon sustainable development, with high lithium selectivity, low impurity content in the filtrate and low acid consumption.
Additive Manufacturing and Precipitation Hardening of Low-Alloyed Copper Alloys Containing Chromium and Hafnium
Authors: Dölling Julia , Gruber Samira , Kovermann Felix , Stepien Lukas , Beeh Elmar , Lopez Elena , Leyens Christoph , Wobker Hans-Günther , Zilly Andreas
Published: November 2024

Copper alloys with chromium and hafnium offer the possibility of precipitation hardening and combine enhanced strength with high electrical and thermal conductivities. The production process, which starts with raw materials, involves powder production by gas atomization and leads to additive manufacturing by laser powder bed fusion with different parameter sets. The aim is to utilize precipitation reactions afterwards in CuHf0.7Cr0.35 during temperature exposure for further property optimization. This research focuses on the low-alloyed copper alloy with hafnium and chromium, compares this with conventionally manufactured specimens, and relates the alloy to additively manufactured specimens of other benchmark alloys such as CuCr1Zr. Measurements of hardness and electrical conductivity are accompanied by metallographic investigations to understand the behavior of CuHf0.7Cr0.35 manufactured by generative methods. In the as-built condition, melting traces remain visible in the microstructure, and hardness values of 101 HV and an electrical conductivity of 17.5 MS/m are reached. Solution annealing completely recrystallizes the microstructure, and the following quenching holds further alloying elements in supersaturated solid solution, resulting in 73 HV and 16.5 MS/m. Subsequent target-oriented precipitation reactions enable peak values of about 190 HV and 42 MS/m. Future research will assess mechanical and physical properties at elevated temperatures and evaluate possible applications.
Possible Missing Sources of Atmospheric Glyoxal Part II: Oxidation of Toluene Derived from the Primary Production of Marine Microorganisms
Authors: Williams Renee T. , Caspers-Brown Annika , Michaud Jennifer , Stevens Natalie , Meehan Michael , Sultana Camille M. , Lee Christopher , Malfatti Francesca , Zhou Yanyan , Azam Farooq , Prather Kimberly A. , Dorrestein Pieter , Burkart Michael D. , Pomeroy Robert S.
Published: November 2024

Background: Glyoxal has been implicated as a significant contributor to the formation of secondary organic aerosols, which play a key role in our ability to estimate the impact of aerosols on climate. Elevated concentrations of glyoxal over open ocean waters suggest that there exists an additional source, different from urban and forest environments, which has yet to be identified. Methods: Based on mass spectrometric analyses of nascent sea spray aerosols (SSAs) and gas-phase molecules generated during the course of a controlled algal bloom, the work herein suggests that marine microorganisms are capable of excreting toluene in response to environmental stimuli. Additional culture flask experiments demonstrated that pathogenic attack could also serve as a trigger for toluene formation. Using solid-phase microextraction methods, the comparison of samples collected up-channel and over the breaking wave suggests it was transferred across the air–water interface primarily through SSA formation. Results: The presence and then absence of phenylacetic acid in the SSA days prior to the appearance of toluene support previous reports that proposed toluene is produced as a metabolite of phenylalanine through the Shikimate pathway. As a result, once in the atmosphere, toluene is susceptible to oxidation and subsequent degradation into glyoxal. Conclusions: This work adds to a minimal collection of literature that addresses the primary production of aromatic hydrocarbons from marine microorganisms and provides a potential missing source of glyoxal that should be considered when accounting for its origins in remote ocean regions.
Strategy for Optimizing Vitamin B12 Production in Pseudomonas putida KT2440 Using Metabolic Modeling
Authors: Prieto-de Lima Thomaz Satuye , Rojas-Jimenez Keilor , Vaglio Christopher
Published: November 2024

Background/Objectives: Vitamin B12 is very important for human health, as it is a cofactor for enzymatic activities and plays various roles in human physiology. It is highly valued in the pharmaceutical, food, and additive production industries. Some of the bacteria currently used for the vitamin production are difficult to modify with gene-editing tools and may have slow growth. We propose the use of the bacteria Pseudomonas putida KT2440 for the production of vitamin B12 because it has a robust chassis for genetic modifications. The present wok evaluates P. putida KT2440 as a host for vitamin B12 production and explore potential gene-editing optimization strategies. Methods: We curated and modified a genome-scale metabolic model of Pseudomonas putida KT2440 and evaluated different strategies to optimize vitamin B12 production using the knockin and OptGene algorithms from the COBRA Toolbox. Furthermore, we examined the presence of riboswitches as cis-regulatory elements and calculated theoretical biomass growth yields and vitamin B12 production using a flux balance analysis (FBA). Results: According to the flux balance analysis of P. putida KT2440 under culture conditions, the biomass production values could reach 1.802 gDW−1·h1·L−1, and vitamin B12 production could reach 0.359 µmol·gDW−1·h−1·L−1. The theoretical vitamin B12 synthesis rate calculated using P. putida KT2040 with two additional reactions was 14 times higher than that calculated using the control, Pseudomonas denitrificans, which has been used for the industrial production of this vitamin. Conclusions: We propose that, with the addition of aminopropanol linker genes and the modification of riboswitches, P. putida KT2440 may become a suitable host for the industrial production of vitamin B12.
Effect of Selective Milling on the Concentration Process of Critical Raw Materials from MSW Incinerator Bottom Ash
Authors: Adhiwiguna Ida B. G. S. , Sahbudin S. Humaira , Ruhkamp Winfried , Warnecke Ragnar , Deike Rüdiger
Published: November 2024

This research introduces selective milling as a reliable and effective initial concentration process to enable efficient separation and ensure high recovery rates of valuable and critical materials (minerals and metals) from processed incinerator bottom ash (pr.IBA), a treated mineral fraction originating from the conventional municipal solid waste (MSW) incinerator bottom ash (IBA) processing steps. Four different types of pr.IBA (each sample weighing up to three tons) were selectively milled using a demonstration-scale vertical roller mill to produce three distinct products: fine, middle, and coarse fractions. Chemical analysis demonstrated that a concentration step after selective milling could be reliably achieved regardless of the variation in the sources and qualities of the input materials. Specifically, calcium-containing compounds can be enriched in the fine fraction, potentially containing Ca2SiO4, CaSO4, and CaCO3. Complementary to its particle size equivalent to the raw mix, this calcium segregation could be valuable as an alternative material in cement clinker production. Conversely, the segregation of metal-bearing substances, particularly iron and copper, was detected in the coarse fraction. Such segregation is comparable to specific ore grades and enhances the possibility of metal recovery from pr.IBA.
Gypsum: From the Equilibrium to the Growth Shapes—Theory and Experiments
Authors: Aquilano Dino , Bruno Marco , Ghignone Stefano
Published: November 2024

The gypsum crystals (CaSO4·2H2O) crystallizes in a low symmetry system (monoclinic) and shows a marked layered structure along with a perfect cleavage parallel to the {010} faces. Owing to its widespread occurrence, as a single or twinned crystal, here the gypsum equilibrium (E.S.) and growth shapes (G.S.) have been re-visited. In making the distinction among E.S. and G.S., in the present work, the basic difference between epitaxy and homo-taxy is clearly evidenced. Gypsum has also been a fruitful occasion to recollect the general rules concerning either contact or penetration twins, for free growing and for twinned crystals nucleating onto pre-existing substrates. Both geometric and crystal growth aspects have been considered as well, by unifying theory and experiments of crystallography and crystal growth through the intervention of βadh, the physical quantity representing the specific adhesion energy between gypsum and other phases. Hence, the adhesion energy allowed us to systematically use the Dupré’s formula. In the final part of the paper, peculiar attention has been paid to sediments (or solution growth) where the crystal size is very small, in order to offer a new simple way to afford classical (CNT) and non-classical nucleation (NCNT) theories, both ruling two quantities commonly used in the industrial crystallization: the total induction times (tindtotal) and crystal size distribution (CSD).
M-Doped (M = Zn, Mn, Ni) Co-MOF-Derived Transition Metal Oxide Nanosheets on Carbon Fibers for Energy Storage Applications
Authors: González-Banciella Andrés , Martinez-Diaz David , de Hita Adrián , Sánchez María , Ureña Alejandro
Published: November 2024

Carbon fiber, with its strong mechanical properties and electrical conductivity, is ideal as a fiber electrode in wearable or structural energy storage devices. However, its energy storage capacity is limited, and coatings like transition metal oxides (TMOs) enhance its electrochemical performance. Metal–organic frameworks (MOFs) are commonly used to grow TMOs on carbon fibers, increasing the surface area for better energy storage. Despite this, TMOs have limited electrical conductivity, so ion exchange is often used to dope them with additional cations, improving both conductivity and energy storage capacity. This study compares different ion-exchange cations in ZIF-L-derived TMO coatings on carbon fiber. Testing both supercapacitor and Li-ion battery applications, Ni-doped samples showed superior results, attributed to their higher exchange ratio with cobalt. As a supercapacitor electrode, the Ni-doped material achieved 13.3 F/g at 50 mA/g—66% higher than undoped samples. For Li-ion battery anodes, it reached a specific capacity of 410.5 mAh/g at 25 mA/g, outperforming undoped samples by 21.4%.
Portable Homemade Magnetic Hyperthermia Apparatus: Preliminary Results
Authors: Castelo-Grande Teresa , Augusto Paulo A. , Gomes Lobinho , Calvo Eduardo , Barbosa Domingos
Published: November 2024

This study aims to describe and evaluate the performance of a new device for magnetic hyperthermia that can produce an alternating magnetic field with adjustable frequency without the need to change capacitors from the resonant bank, as required by other commercial devices. This innovation, among others, is based on using a capacitator bank that dynamically adjusts the frequency. To validate the novel system, a series of experiments were conducted using commercial magnetic nanoparticles (MNPs) demonstrating the device’s effectiveness and allowing us to identify new challenges associated with the design of more powerful devices. A computational model was also used to validate the device and to allow us to determine the best system configuration. The results obtained are consistent with those from other studies using the same MNPs but with magnetic hyperthermia commercial equipment, confirming the good performance of the developed device (e.g., consistent SAR values between 1.37 and 10.80 W/gMNP were obtained, and experiments reaching temperatures above 43 °C were also obtained). This equipment offers additional advantages, including being economical, user-friendly, and portable.
Youth Healthy Eating Index (YHEI) and Diet Adequacy in Relation to Country-Specific National Dietary Recommendations in Children and Adolescents in Five Mediterranean Countries from the DELICIOUS Project
Authors: Giampieri Francesca , Rosi Alice , Scazzina Francesca , Frias-Toral Evelyn , Abdelkarim Osama , Aly Mohamed , Zambrano-Villacres Raynier , Pons Juancho , Vázquez-Araújo Laura , Sumalla Cano Sandra , Elio Iñaki , Monasta Lorenzo , Mata Ana , Pardo María Isabel , Busó Pablo , Grosso Giuseppe
Published: November 2024

Background/Objectives: The diet quality of younger individuals is decreasing globally, with alarming trends also in the Mediterranean region. The aim of this study was to assess diet quality and adequacy in relation to country-specific dietary recommendations for children and adolescents living in the Mediterranean area. Methods: A cross-sectional survey was conducted of 2011 parents of the target population participating in the DELICIOUS EU-PRIMA project. Dietary data and cross-references with food-based recommendations and the application of the youth healthy eating index (YHEI) was assessed through 24 h recalls and food frequency questionnaires. Results: Adherence to recommendations on plant-based foods was low (less than ∼20%), including fruit and vegetables adequacy in all countries, legume adequacy in all countries except for Italy, and cereal adequacy in all countries except for Portugal. For animal products and dietary fats, the adequacy in relation to the national food-based dietary recommendations was slightly better (∼40% on average) in most countries, although the Eastern countries reported worse rates. Higher scores on the YHEI predicted adequacy in relation to vegetables (except Egypt), fruit (except Lebanon), cereals (except Spain), and legumes (except Spain) in most countries. Younger children (p < 0.005) reporting having 8–10 h adequate sleep duration (p < 0.001), <2 h/day screen time (p < 0.001), and a medium/high physical activity level (p < 0.001) displayed a better diet quality. Moreover, older respondents (p < 0.001) with a medium/high educational level (p = 0.001) and living with a partner (p = 0.003) reported that their children had a better diet quality. Conclusions: Plant-based food groups, including fruit, vegetables, legumes, and even (whole-grain) cereals are underrepresented in the diets of Mediterranean children and adolescents. Moreover, the adequate consumption of other important dietary components, such as milk and dairy products, is rather disregarded, leading to substantially suboptimal diets and poor adequacy in relation to dietary guidelines.
The Effects of Carbohydrate Mouth Rinse on Psychophysiological Responses and Kinematic Profiles in Intermittent and Continuous Small-Sided Games in Adolescent Soccer Players: A Randomized, Double-Blinded, Placebo-Controlled, and Crossover Trial
Authors: Soylu Yusuf , Chmura Paweł , Arslan Ersan , Kilit Bulent
Published: November 2024

Background: Mouth rinsing (MR) with a carbohydrate solution is one of the most popular methods athletes use to improve their game-based performance due to its acute ergogenic effect. Objectives: This study aimed to evaluate the effects of the carbohydrate MR intervention on psychophysiological responses and kinematic profiles during intermittent (INT) and continuous (CON) 4-a-side small-sided soccer games (SSGs). Methods: Thirty-two adolescent soccer players (age: 16.5 ± 0.5 years) played six bouts of 4-a-side SSGs with MRINT or MRCON at 3-day intervals in a randomized, double-blinded, placebo-controlled, and crossover study design. Psychophysiological responses and kinematic profiles were continuously recorded during all games. The rating of perceived exertion (RPE), the rating scale of mental effort (RSME), and the physical enjoyment scores (PES) were also determined at the end of each game. Results: The MRCON induced higher psychophysiological responses such as RPE, internal training load (ITL), and RSME (p ≤ 0.05, d values ranging from 0.50 to 1.04 [small to moderate effect]). Conversely, the MRINT induced higher PES (p ≤ 0.05, d values = 1.44 [large effect]) compared to MRCON. Although the MR intervention led to similar improvements in the performance of 4-a-side MRINT and MRCON, there was no significant difference between the groups. Conclusions: Our results suggest that the MR intervention can be used as an effective ergogenic supplement for acute game performance enhancement, regardless of the game’s structure.
Effectiveness of Probiotics, Prebiotics, and Synbiotics in Managing Insulin Resistance and Hormonal Imbalance in Women with Polycystic Ovary Syndrome (PCOS): A Systematic Review of Randomized Clinical Trials
Authors: Martinez Guevara Darly , Vidal Cañas Sinthia , Palacios Isabela , Gómez Alejandra , Estrada María , Gallego Jonathan , Liscano Yamil
Published: November 2024

Background/Objectives: Polycystic ovary syndrome is a common endocrine disorder in women of reproductive age characterized by insulin resistance and hormonal imbalances. Recent research suggests that probiotics and synbiotics may improve these parameters by modulating the gut microbiota. This study systematically reviewed randomized clinical trials evaluating the impact of probiotic, prebiotic, and synbiotic supplementation on insulin resistance and hormonal parameters in women with PCOS. Methods: Exhaustive searches were conducted in PubMed, Cochrane CENTRAL, Scopus, Web of Science, and Embase, following PRISMA guidelines. Randomized trials assessing supplementation with probiotics, prebiotics, or synbiotics for at least 8 weeks in women diagnosed with PCOS according to the Rotterdam criteria were included. Data on participants, interventions, and outcomes related to insulin resistance and hormones were extracted. Results: Eleven studies from Iran involving overweight or obese women aged 15 to 48 were included. Probiotic and synbiotic supplementation showed significant improvements in insulin resistance (reductions in HOMA-IR, fasting glucose, and insulin), lipid profiles (decreased LDL and triglycerides; increased HDL), and hormonal balance (increased SHBG, decreased total testosterone). Synbiotics had more pronounced effects than probiotics or prebiotics alone. Adherence was high, and side effects were minimal. Conclusions: Despite promising results, limitations such as small sample sizes, homogeneous populations, and short intervention durations limit the generalization of the findings. Larger, longer, multicenter trials with diverse populations and standardized methodologies are needed to confirm the efficacy and safety of synbiotics in managing PCOS. Integrating these interventions could improve clinical management and quality of life for affected women, but additional evidence is required to support widespread use.
Harmonizing Dietary Exposure of Adult and Older Individuals: A Methodological Work of the Collaborative PROMED-COG Pooled Cohorts Study
Authors: Prinelli Federica , Trevisan Caterina , Conti Silvia , Maggi Stefania , Sergi Giuseppe , Brennan Lorraine , de Groot Lisette C. P. G. M. , Volkert Dorothee , McEvoy Claire T. , Noale Marianna
Published: November 2024

Objectives: The PROtein-enriched MEDiterranean diet to combat undernutrition and promote healthy neuroCOGnitive ageing in older adults (PROMED-COG) is a European project that investigates the role of nutritional status on neurocognitive ageing. This methodological paper describes the harmonization process of dietary data from four Italian observational studies (Pro.V.A., ILSA, BEST-FU, and NutBrain). Methods: Portion sizes and food frequency consumption within different food frequency questionnaires were retrospectively harmonized across the datasets on daily food frequency, initially analyzing raw data using the original codebook and establishing a uniform food categorization system. Individual foods were then aggregated into 27 common food groups. Results: The pooled cohort consisted of 9326 individuals (40–101 years, 52.4% female). BEST-FU recruited younger participants who were more often smokers and less physically active than those of the other studies. Dietary instruments varied across the studies differing in the number of items and time intervals assessed, but all collected dietary intake through face-to-face interviews with a common subset of items. The average daily intakes of the 27 food groups across studies varied, with BEST-FU participants generally consuming more fruits, vegetables, red meat, and fish than the other studies. Conclusions: Harmonization of dietary data presents challenges but allows for the integration of information from diverse studies, leading to a more robust and statistically powerful dataset. The study highlights the feasibility and benefits of data harmonization, despite inherent limitations, and sets the stage for future research into the effects of diet on cognitive health and aging.