Hasil untuk "Chemical industries"

Souhaila Nider, Femke De Ceulaer, Berfu Göksel et al.

Direct Ink Writing (DIW) has been extensively studied for creating hierarchical porous structures over recent decades. It finds applications in various fields, including aeronautics, industry, energy, and healthcare. On the other hand, capillary suspensions are an emerging field with significant potential for porous material development. These suspensions, typically three-phase systems, consist of solid particles interconnected by a secondary fluid (usually < 5 vol%), which is immiscible with the main one. Upon fluid removal and subsequent thermal treatment, they form a spanning particle network.This study explores the utilisation of β-TCP-based capillary suspensions as DIW inks for fabricating hierarchically porous scaffolds with two different secondary fluids. Rheological assessment of the inks demonstrates shear thinning behaviour, high yield stress, high moduli, and network rebuilding capabilities. While sucrose-based inks exhibit better printability, the ink incorporating silica nanoparticles exhibit structures with the highest porosity.

Hongwei Pang, Guangyao Liu, Xinming Wang et al.

Photocatalytic oxidation technology harnesses solar energy for pollutant mineralization, presenting significant potential for environmental applications. A critical bottleneck remains the development of high-performance photocatalysts. This study centers on the non-metallic semiconductor material graphitic carbon nitride (g-C₃N₄). To overcome the inherent limitations of pristine g-C₃N₄, including limited surface area, rapid charge carrier recombination, and inadequate active sites, it implements surface engineering strategies employing acidic (H₂SO₄) or basic (K₂CO₃) agents to modulate microstructure, introduce defect sites (cyano/amino groups), and optimize bandgap engineering. These modifications synergistically enhanced photogenerated charge carrier separation efficiency and surface reactivity, leading to efficient dye degradation. Notably, the K₂CO₃-modified catalyst (g-C₃N₄-OH), synthesized with a mass ratio of m(g-C₃N₄):m(K₂CO₃) = 1:1, achieved 92.2% Rhodamine B degradation within 50 min under visible light, surpassing pristine g-C₃N₄ (20.6%), the optimized H₂SO₄-modified sample (g-C₃N₄-HS, 60.9%), and even template-synthesized g-C₃N₄-SBA (79.6%). The g-C₃N₄-OH catalyst demonstrated exceptional performance under both visible light and natural solar illumination. Combining facile synthesis, cost-effectiveness, superior activity, and robust stability, this work provides a novel approach for developing high-efficiency non-metallic photocatalysts applicable to dye wastewater.

Long Chen, Xiaoming Shi, Jiyang Xie et al.

Ferroelectric materials are highly promising for next-generation electro–optic (EO) modulators because of their ultrafast and efficient light modulation. However, efforts to maximize polarization freedom for large refractive index modulation—through domain engineering, epitaxial strain, and defect engineering—have hit limitations, leaving intrinsic polarization mechanisms largely unexplored. Here, we report a giant effective EO coefficient (~233.5 pm/V) in PbZr0.52Ti0.48O3 (PZT) films, which surpasses all reported values measured under an in-plane electric field and significantly exceeds the theoretical limit (~13 pm/V) as well as the value of LiNbO3 (~31 pm/V). Beyond conventional domain switching, phase transitions and domain wall variations critically enhance the EO effect. The highly relaxed structure of the PZT film, with mixed [001] and [100] orientations and disordered nanoscale phases, enables unprecedented polarization control. This unique configuration breaks the theoretical EO coefficient limit, bridging the gap between predictions and experimental results. Owing to its high Curie temperature and compatibility with wafer-scale fabrication, PZT has emerged as a promising candidate for next-generation high-performance EO modulators. Our findings not only advance the frontiers of ferroelectric EO materials but also pave the way for exploring other ferroelectric thin-film devices, such as those for energy storage and electrocaloric cooling, by leveraging enhanced polarization modulation mechanisms.

Samantha C. Karunarathna, Saowaluck Tibpromma, Wenhua Lu et al.

Pigmented Basidiomycete fungi are emerging as multifunctional and environmentally friendly substitutes to man-made food coloring. In addition to their bright colors, pigments from these fungi, including melanin, pulvini acids, carotenoids, and phenoxazines, also exhibit potent antioxidant, anti-microbial, and even potential therapeutic effects. Fungal pigments offer greater stability under processing conditions compared to those of plant origin and can be cost-effectively produced by biotechnological culture, particularly agro-waste-based fermentation systems. This review provides an overview of the chemical diversity, biosynthesis, and extraction of pigments from food and non-food Basidiomycetes such as the genera Cantharellus, Pycnoporus, Boletus, Pleurotus, and others. Particular emphasis is on their applications in the food and nutraceutical industries, challenges in scaling up and regulatory aspects, and future prospects of fungal biotechnology as a renewably available source of natural pigments.

Alejandro Barrios-Nolasco, Carlos Omar Castillo-Araiza, Sergio Huerta-Ochoa et al.

Solid-State Fermentation (SSF) offers a valuable process for converting agri-food by-products (AFBP) into high-value metabolites, with <i>Yarrowia lipolytica</i> 2.2ab (<i>Yl</i>2.2ab) showing significant potential under laboratory-scale controlled conditions; however, its assessment in larger-scale bioreactor scenarios is needed. This work evaluates <i>Yl</i>2.2ab’s performance in a bench-scale custom-designed packed-tray bioreactor. Key features of this bioreactor design include a short packing length, a wall-cooling system, and forced aeration, enhancing hydrodynamics and heat and mass transfer within the tray. Preliminary studies under both abiotic and biotic conditions assessed <i>Yl</i>2.2ab’s adaptability to extreme temperature variations. The results indicated effective oxygen transport but poor heat transfer within the tray bed, with <i>Yl</i>2.2ab leading to a maximum growth rate of 28.15 m_gx g_ssdb⁻¹ h⁻¹ and maximum production of proteases of 40.10 U g_ssdb⁻¹ h⁻¹, even when temperatures at the packed-tray outlet were around 49 °C. Hybrid-based modeling, incorporating Computational Fluid Dynamics (CFD) and Pseudo-Continuous Simulations (PCSs), elucidated that the forced-aeration system successfully maintained necessary oxygen levels in the bed. However, the low thermal conductivity of AFBP posed challenges for heat transfer. The bioreactor design presents promising avenues for scaling up SSF to valorize AFBP using <i>Yl</i>2.2ab’s extremophilic capabilities.

Antonia del Rocío López Guemez, Adrián Cordero García, José Luis Cervantes López et al.

The increase in pollution, using photocatalytic materials to degrade organic pollutants remains in force. ZnO is the most used semiconductors for photocatalytic applications. The oriented growth of nanostructures on substrates or seed layers (SL) improves the physical and chemical properties compared to the bulk-grown material. In this work, the photocatalytic efficiency of ZnO nanorods and nanoflowers was evaluated, obtained by hydrothermal growth (HG) over SL deposited by the spin-coating technique (SCT). The characterizations results showed two types of growth: 1D nanostructures with a dimension in the range of 400–1000 nm and diameters of 70–100 nm, and 1D microstructures with approximate 5–11 μm length and diameters of 1–2 μm. However, in the 7 SL system, micro prisms were generated, which led to the formation of 3D nanostructures (micro flowers) of ZnO with a maximum of 6 μm in diameter. The system with 1D and 3D ZnO nanostructures, grown in 7 SL, was the most efficient methylene blue degradation. Achieving 100% transformation in 120 min, with a rate constant of 2.98 × 10−2 min−1. The results show that the SCT deposit combined with the sol–gel method and HG produces 1D and 3D structures with high potential in photocatalytic degradation. Resumen: El aumento de la contaminación, el empleo de materiales fotocatalíticos para degradar contaminantes orgánicos continúa vigente. El óxido de zinc (ZnO) es el semiconductor más utilizado para aplicaciones fotocatalíticas. El crecimiento orientado de nanoestructuras sobre capas semillas (SL) mejora las propiedades físicas y químicas comparado con el material crecido en bulto. En este trabajo se evaluó la eficiencia fotocatalítica de nanovarillas y nanoflores de ZnO obtenidas por crecimiento hidrotérmico (HG) sobre SL depositadas por la técnica spin coating (SCT). Los resultados de las caracterizaciones mostraron dos tipos de crecimiento: nanoestructuras 1D con dimensiones en el rango de 400 a 1.000 nm y diámetros de 70 a 100 nm, y microestructuras 1D con longitud aproximada de 5 a 11 μm y diámetros de 1 a 2 μm. Sin embargo, en el sistema de 7 SL se generaron microprismas orientados, generando nanoestructuras 3D (microflores) con un diámetro máximo de 6 μm. Este sistema fue el más eficiente en la degradación de azul de metileno. Degradando de 100% en 120 min, con una constante de velocidad de 2,98 x 10-2 min-1. Los resultados indican que la SCT combinada con el método sol-gel y el HG produce estructuras 1D y 3D con alto potencial de degradación fotocatalítica.

Jingxue Yue, Xushen Han, Yan Jin et al.

Mustard tuber wastewater (MTW) is an ultra-hypersaline high-strength acid organic wastewater. Aerobic granular sludge (AGS) has been demonstrated to have high tolerance to high organic loading rate (OLR), high salinity, and broad pH ranges. However, most studies were conducted under single stress, and the performance of AGS under multiple stresses (high salinity, high OLR, and low pH) was still unclear. Herein, mature AGS was used to try to treat the real MTW at 9% salinity, pH of 4.1–6.7, and OLR of 1.8–7.2 kg COD/m³·d. The OLR was increased, and the results showed that the upper OLR boundary of AGS was 5.4 kg COD/m³·d (pH of 4.2) with relatively compact structure and high removal of TOC (~93.1%), NH₄⁺-N (~88.2%), and TP (~50.6%). Under 7.2 kg COD/m³·d (pH of 4.1), most of the AGS was fragmented, primarily due to the multiple stresses. 16S rRNA sequencing indicated that <i>Halomonas</i> dominated the reactor during the whole process with the presence of <i>unclassified-f-Flavobacteriaceae</i>, <i>Aequorivita</i>, <i>Paracoccus</i>, <i>Bradymonas</i>, and <i>Cryomorpha</i>, which played key roles in the removal of TOC, nitrogen, and phosphorus. This study investigated the performance of AGS under multiple stresses, and also brought a new route for highly-efficient simultaneous nitrification–denitrifying phosphorus removal of real MTW.

Xiao-Ling Tang, Jia-Wei Yu, Yu-Heng Geng et al.

The increasingly complex molecular structures and high requirements of advanced industries are triggering a transformation in chemical production modes. Bio-manufacturing provides efficient strategies and brings the advantages of high atomic economy, few side reactions, and strong adaptability to processes, as well as environmental friendliness, which can contribute toward global efforts against greenhouse effect and environmental pollution. The significance of bio-manufacturing can be specifically illustrated by examining the bio-manufacturing process from the scientific discovery of a key compound to its technological integration and engineering innovation. The development of statins—important drugs for hypercholesterolemia treatment—is a good example of the progress and application of bio-manufacturing. The production of the first-generation statins from microorganisms, the second-generation statins using bioconversion, and the third-generation statins through an evolution from total chemical synthesis to chemoenzymatic synthesis demonstrates the technological and engineering revolution of bio-manufacturing, which is of great importance for energy conservation, cost saving, and waste emission reduction. With advances in cutting-edge biotechnologies, as well as the integration of multiple disciplines, bio-manufacturing is expected to promote the advancement of more intelligent processes to realize sustainable and green industrial development.

Hongyu Zhang, Deguang Zhang, Ran Liu et al.

The special structure of pentostatin causes it to possess a wide spectrum of biological and pharmacological properties, and it has been extensively employed to treat malignant tumors and is the first-line treatment for hairy cell leukemia. Pentostatin is mainly distributed in several actinomycetes and fungi species. However, its low titer in microbes is not able to meet medical needs. Here, we report a strain improvement strategy based on combined atmospheric and room-temperature plasma (ARTP) mutagenesis and ribosome engineering screening, as well as fermentation optimization, for enhanced pentostatin production. The original strain, <i>Actinomadura</i> sp. ATCC 39365, was treated with ARTP and screened by ribosome engineering to obtain one stable pentostatin high-yield mutant <i>Actinomadura</i> sp. S-15, which produced 86.35 mg/L pentostatin, representing a 33.79% increase compared to <i>Actinomadura</i> sp. ATCC 39365. qRT-PCR analysis revealed that pentostatin biosynthesis-related gene expression was significantly upregulated in <i>Actinomadura</i> sp. S-15. Then, to further enhance pentostatin production, the fermentation medium was optimized in flask culture and the pentostatin production of <i>Actinomadura</i> sp. S-15 reached 152.06 mg/L, which is the highest pentostatin production reported so far. These results demonstrate the effectiveness of combined ARTP mutation, ribosome engineering screening, and medium optimization for the enhancement of pentostatin production, and provide a methodology enabling the sustainable production of pentostatin on an industrial scale.

Jian Wang, Quanjin Jiang, Zhenyu Huang et al.

Soybean meal is a class of by-products obtained from the processing of soybean products. Despite its high nutritional value, the presence of glycoside isoflavones limits human use of soybean meal. This study evaluated the effect of solid-state fermentation (SSF) with different edible mushroom mycelia (<i>Pleurotus ostreatus</i>, <i>Hericium erinaceus</i>, and <i>Flammulina velutipes</i>) on the proximate composition, antioxidant properties, and physicochemical properties of fermented soybean meal powder (SP). The results revealed that fermented SP had a higher nutritional value when compared to SP. <i>P. ostreatus</i> was the most pronounced among the three species. Crude protein content was found to have increased by 9.49%, while the concentration of glutamate and aspartic acid increased by 23.39% and 23.16%, respectively. SSF process significantly increased the total polyphenol content (TPC) and aglycone isoflavone content by 235.9% and 324.12%, respectively, resulting in increased antioxidant activity (evaluated by the DPPH, •OH, ABTS⁺ assays). Microstructural changes in fermented SP and nutrient degradation and utilization were observed. Thus, fermented SP can be used as a raw material with enhanced nutritional properties to develop new functional foods, such as plant-based foods represented by plant meat. It provides a promising approach for increasing the added value of soybean meal.

Zi-Han Wang, Jing-Yan Tan, Yu-Tong Zhang et al.

Lignocellulose bioconversion to hydrogen has been proposed as a promising solution to augment the fossil fuel dominated energy market. However, little is known about the effects of the substrate concentration supplied on hydrogen production. Herein, the hydrogen producing bacteria <i>Thermoanaerobacter thermosaccharolyticum</i> W16 feeding with respective glucose, xylose, and glucose and xylose mixture (glucose–xylose) at different concentrations was evaluated, to study whether substrate concentration could impact the lignocellulose bioconversion to hydrogen and the associated kinetics. An average bio-hydrogen yield of 1.40 ± 0.23 mol H₂·mol⁻¹ substrate was obtained at an average substrate concentration of 60.89 mM. The maximum bio-hydrogen production rate of 0.25 and 0.24 mol H₂·mol⁻¹ substrate h⁻¹ was achieved at a substrate concentration of 27.75 mM glucose and 30.82 mM glucose–xylose, respectively, while the value reached the high point of 0.08 mol H₂·mol⁻¹ xylose·h⁻¹ at 66.61 mM xylose. Upon further energy conversion efficiency (ESE) analysis, a substrate of 10 g·L⁻¹ (amounting to 55.51 mM glucose, 66.61 mM xylose or 60.55 mM glucose–xylose) provided the maximum ESE of 15.3 ± 0.3%, which was 15.3% higher than that obtained at a substrate concentration of 5 g·L⁻¹ (amounting to 27.75 mM glucose, 33.30 mM xylose or 30.28 mM glucose–xylose). The findings could be helpful to provide effective support for the future development of efficient and sustainable lignocellulosic bio-hydrogen production.

Namrata Chandel, Neeraj Mehta, Alaa Dahshan

The kinetics of the thermally induced glass / crystal phase transformation of chalcogenide glasses plays an important role in determining their candidacy for optical phase change memory applications. The rate of crystallization and the corresponding activation energy are the two crucial kinetic parameters that reflect the durability and quality (i.e., storage properties) of phase change materials. This script deals with metal-induced effects on thermally regulated non-isothermal crystallization in a new glass alloy of Se-Te-Sn using calorimetric measurements. The elements Antimony (Sb), Cadmium (Cd) and Indium (In) have been used as structural modifiers for this purpose. The crystallization and glass transition kinetics of these glass alloys have been investigated by thermal analysis of several kinetic parameters such as the parameter of order n, the maximum crystallization temperature Tc, the crystallization rate K and the consequent activation energy Ec). A DSC is used in non-isothermal mode for the present studies. The values of the activation energy Ec are determined using the data obtained from the displacement of the exothermic peaks of crystallization in non-isothermal DSC plots at various heating rates. The role of the additives Sb, Cd and In in the variation in the rate of crystallization K of and the Avrami index (n) for each glass alloy is also examined. Detailed thermal analysis of the kinetic data confirms the superiority of Cd over the other two additives (In and Sb) for optimization of the kinetic properties of the main SeTeSn glass. Resumen: La cinética de la transformación de fase vidrio/cristal inducida térmicamente de los vidrios calcogenuros desempeña un papel importante en la determinación de su candidatura para las aplicaciones de memoria óptica de cambio de fase. La tasa de cristalización y la energía de activación correspondiente son los dos parámetros cinéticos cruciales que reflejan la durabilidad y la calidad (es decir, las propiedades de almacenamiento) de los materiales de cambio de fase.El presente guión trata de los efectos inducidos por metales sobre la cristalización no isotérmica regulada térmicamente en una nueva aleación vítrea de Se-Te-Sn, utilizando mediciones calorimétricas. Los elementos antimonio (Sb), cadmio (Cd) e indio (In) se han empleado como modificadores estructurales para este propósito. La cinética de cristalización y transición vítrea de estas aleaciones de vidrio se ha investigado mediante el análisis térmico de varios parámetros cinéticos como el de orden n, la temperatura máxima de cristalización (Tc), la velocidad de cristalización (K) y la energía de activación consiguiente (Ec). Se usa un DSC en modo no isotérmico para los presentes estudios. Los valores de la energía de activación Ec se determinan utilizando los datos obtenidos del desplazamiento de los picos exotérmicos de cristalización en gráficos de DSC no isotérmicos a diversas velocidades de calentamiento. También se examina el papel de los aditivos Sb, Cd e In en la variación en la K y el índice de Avrami (n) para cada aleación vítrea. El análisis térmico detallado de los datos cinéticos confirma la superioridad del Cd sobre los otros dos aditivos (In y Sb) para la optimización de las propiedades cinéticas del vidrio principal Se-Te-Sn.

Syed Kazmi, Zahoor Awan, Saud Hashmi

With the increased amount of focus is being put towards reducing the emissions results from fossil fuel usually composed of hydrocarbons and impurities. The study aim at utilizing the ability of 1-octyl-3-methylimidazolium tetrafluoroborate [OMIM][BF4]. Ionic liquid as the suitable solvent for the extraction of the thiophene and its derivatives from the model gasoline. The process simulation was performed on the ASPEN plus(V8.8) with the help of UNIFAC as the thermodynamic model, previously NRTL was used as the method to calculate the interaction. The different parametric analysis was calculated for the removal of thiophene-based compounds from model gasoline. Outcomes acquired shows the significance of imidazolium-based ionic liquid(ILs) 1-octyl-3-methylimidazolium tetrafluoroborate towards the separation about S-contents from the liquid fuels at an optimum process condition of 30ᵒC and 2 bar pressure with the 1:1 ratio of ionic liquid and model gasoline which confirms the experimental outcomes obtained previously in the literature. By using these mild conditions, easy phase separation, high reusability, and various other process parameters have been established based on the process simulation model using ASPEN plus.

Youcef Rouabhi, Azzedine Lounis

The already initiated studies are based on size and forms of abrasive grains, but few studies have addressed the influence on the concentration of abrasive grains. This research has been done to remove some of the mysteries associated in the media "abrasives" or "chips" used in vibratory and barrel finishing, this process included within the functions and characteristics of media, its types and shapes, also the selection of the best grade for a given task. The present work provides guidance on the influence on the concentration of the particles (grain) of abrasive granules with the main parameters and technological indices of vibratory finishing treatment,in order to optimize abrasive granules and increase the productivity of the vibratory finishing taking into account media, which has certain characteristics, make it unique in its capabilities.

Jiří Fíla, Martina Eliášová, Zdeněk Sokol

The main advantage of solid bricks over hollow blocks is substantially higher compressive strength. On the other hand, solid bricks have much higher thermal conductivity, which would lead to major heat loss when used for exterior walls. Masonry pillars and walls are usually loaded by compression and/or bending resulting from the eccentricity of vertical load or wind load. In case of solid glass bricks, compressive strength is about ten times higher than tension strength therefore the limiting factor of the glass masonry is tensile stress resulting from the bending. Whether compared to ceramic or concrete bricks masonry, the glass bricks have a smooth and non-absorbent surface and the adhesion of the mortar to the glass surface is the critical parameter. Presented paper is focused on the experimental investigation of mortar applicable for glass brick masonry with regard to possible use for supporting brick walls or columns. Shear, compression and adhesion tests have been recently performed. Shear and adhesion resistance and failure modes of brick bed joint were determined during series of tests using various mortar composition, two types of surface treatment and different thickness of the mortar joint. Significant influence of the joint thickness on the resistance was found. The compression tests were performed on two small pillars to determine the compression resistance and failure mode of glass bricks walls and pillars. In parallel to these tests, several small-scale tests have been performed to determine of flexural and compressive strength of hardened mortar.

Joren Pelfrene, Sam Van Dam, Siebe Spronk et al.

Laminated glass provides safety in an impact or explosion event by way of a polymer interlayer to which glass fragments adhere upon fracture. The mechanical deformation of the interlayer defines how the impact energy can be absorbed to prevent calamities by flying glass debris, penetration of a blast wave, lacerations, etc. The PVB interlayer used in safety glass shows highly nonlinear viscoelastic material behaviour, with a great sensitivity to temperature and deformation rate. Although various material models for PVB can be found in literature, few publications discuss the full range of its mechanical behaviour and none are found to describe a material model that is valid in a wide range of deformation rates and up to high elongations. Such material model is necessary for the numerical study of the post-fracture response in a dynamic event. The article describes the mechanical behaviour of PVB interlayer and the constitutive models by which the polymer can be represented under different load cases. Tensile experiments of Saflex® PVB are presented for a wide range of deformation rates and up to tearing of the specimens. Subsequently, a method to calibrate a hyper-viscoelastic material model for the interlayer by numerically simulating the tensile tests is developed. The resulting material models are valid up to the tearing strain of the interlayer and are accurate within a specified range of deformation rates and temperatures.

K. Gray, J. Wilkinson

R. Scaife

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Editorial, Equipo