With urbanization progressing, the continuous generation of solid waste from production and daily life makes their recycling and reuse increasingly important. In this paper, magnesium oxysulfate cementitious materials, widely used in construction and environmental engineering for their light weight, high strength, good fire resistance, and low energy consumption, have been prepared in two forms: one with added solid waste and one without. canning electron microscope, quasi static compression, and split Hopkinson Pressure Bar experiments are conducted on the two kinds of magnesium oxysulfate cement (MOSC) to investigate and compare their microscopic configuration and quasi-static and dynamic mechanical properties. The experiments show that due to the addition of solid waste, the compressive strength of MOSC increased significantly at various strain rates, especially when the strain rate was 0.001 s⁻¹, where its strength nearly doubled. It can be seen that the MOSC with solid waste exhibited finer particle sizes from the microstructure of the two types of MOSC, which reduced the porosity of the concrete and further enhanced its compactness, leading to greater compressive strength. Both types of MOSC displayed obvious strain rate effects. Comparing their dynamic increase factor (DIF), it was found that the addition of solid waste weakened the influence of strain rate on MOSC. When the strain rate was low, the MOSC with solid waste exhibited less damage, indicating increased toughness. However, as the strain rate increased, the fracture levels of both types of MOSC became more similar. The MOSC with solid waste showed significant advantages at low strain rates, such as high strength and toughness. This study demonstrates the feasibility and application prospects of using solid waste in magnesium oxysulfate cementitious materials.

The concept of accelerating chemical processes with nanomaterials utilizing the energy collected by plasmon excitations has attracted much interest . Moreover, plasmonic catalysis triggers the segregation of H₂ or adsorbed O₂ (slow processes) under continuous wave excitation via plasmon decay. Here, we present a comprehensive study of the plasmonic and photocatalytic behavior in an environment-friendly medium with AM 1.5G solar light of CuO/Cu2O ultra-thin films grown on a Si substrate using a pulsed laser deposition technique in a vacuum with varying thicknesses. We have produced around 0.59 kmolh⁻¹g⁻¹ H₂ in a CuO/Cu₂O film with a thickness of approximately 27 nm. S-parameter curves from finite element modeling simulations are also used to examine the role of plasmons with metal--dielectric and semiconductor--semiconductor interfaces. The findings demonstrate that the size, composition, and band alignment of two interface materials influence the effects of plasmonic catalysis and synthesis.

Abstract

Supercritical Fluid Extraction (SCFE), a prominent technique utilized for the extraction of essential oils from plant materials, offers several advantages over conventional extraction methods like distillation or solvent extraction. For instance, it provides enhanced extraction efficiency, shorter extraction duration, the preservation of oil quality and aroma, and reduced environmental impact. Here, we reported an optimization study that was conducted at the pilot scale for the Supercritical Fluid Extraction (SCFE) of ginger oil from ginger oleoresin. This study aimed to investigate the influence of extraction temperature, extraction pressure, and CO₂ flow rate on the yield of gingerol compounds, particularly 6-gingerol and total gingerol [1]. Additionally, different absorbents, namely activated charcoal and polyacrylamide-coated silica, were introduced into the extraction column to assess their impact on the extraction process. The results revealed that incorporating polyacrylamide-coated silica as an absorbent in the extraction column yielded the highest percentage of 6-gingerol and total gingerol content. Conversely, the lowest values were observed in the absence of an absorbent. Optimal conditions [2] for achieving maximum 6-gingerol (36.7%) and total gingerol (53.04%) content were determined to be within the temperature range of 40°C to 60°C and the pressure range of 150 to 250 bar during SCFE. The quantification of 6-gingerol and total gingerol content was performed using High-Performance Liquid Chromatography (HPLC), providing reliable experimental data for analysis and comparison purposes. Overall, these findings underscore the efficacy of SCFE coupled with polyacrylamide-coated silica as an absorbent for the extraction of ginger oil, offering potential applications in various industries, such as food, cosmetics, and pharmaceuticals.

References:

[1] Salea R., Veriansyah, B., Tjandrawinata R R., (2017) Optimization and scale-up process for supercritical fluids extraction of ginger oil from Zingiber officinale var. Amarum. The Journal of Supercritical Fluids. 120: 2 (285-294).

[2] Subroto E., Widjojokusumo E., Veriansyah B., Tjandrawinata R R., (2017) Supercritical CO2 extraction of candlenut oil: process optimization using Taguchi orthogonal array and physicochemical properties of the oil. Journal of Food Science and Technology. 54(5): 1286–1292.

Background: The use of traditional metallic bone fixation devices, such as stainless steel and titanium, often leads to complications, including stress shielding, allergic reactions, and imaging interference. This necessitates the exploration of alternative materials with better biomechanical compatibility and reduced adverse effects.

Objective: This research aims to evaluate the efficacy of functionally graded, chopped, carbon-fiber-reinforced polyether ether ketone (CCF/PEEK) composites as bone fixation plates, particularly focusing on their ability to minimize stress-shielding effects while enhancing biocompatibility and healing performance during the bone healing process.

Methods: Finite element analysis (FEA) was employed to examine the effects of stress shielding in bone plates composed of CCF/PEEK composites with various gradient distributions under both static and instantaneous dynamic loading conditions. The FGM bone plate models were developed using ABAQUS software along with user subroutines USDFLD and VUSDFLD, with each FGM plate maintaining an equivalent overall elastic modulus but featuring distinct gradient distributions.

Results: The results revealed that all FGM bone plates exhibited lower stress-shielding effects compared to metal bone plates. Compared with ST316L, the average stresses provided by the FGM3 plate with an elastic modulus gradually increased from the center to both sides are 8.67 %, 10.89 %, and 10.92 % higher in the healing stages of 1 %, 50 %, and 75 %, respectively. At the same time, the ranges of the stress for the FGM3 plate are the lowest (1 % healing stage) and second lowest (50 % and 75 % healing stages) out of all types of plate materials.

Conclusion: The study indicates that CCF/PEEK composites, particularly the FGM3 plate, which has an elastic modulus gradually increased from the center to both sides, can provide maximum stress stimulation and the most uniform stress distribution within the fractured area.

The diagnosis of acute bacterial meningitis is typically made by analyzing sterile body fluids such as cerebrospinal fluid (CSF), pleural, peritoneal and pericardial fluids, and joint fluid. The detection of infectious microorganisms in sterile body fluids is performed using direct examination and culture methods. Even a single colony of a microorganism detected in the culture of a sterile body fluid is considered an infection. However, the presence of very low amounts of microorganisms in sterile body fluids poses a significant problem for disease diagnosis. Therefore, it is often necessary to use concentration and/or enrichment methods to detect microorganisms in CSF and other samples that should be sterile under normal conditions.

The aim of this study is to concentrate infection-causing microorganisms in cerebrospinal fluid by binding them to magnetic nanoparticles and separating them from the supernatant using a magnetic separation method. Magnetic nanoparticles were synthesized using the co-precipitation method. Techniques such as SEM, TEM, FT-IR, zeta potential, and zeta-sizer were used for characterization. Stability studies of the magnetic nanoparticles were conducted.

The detection of infectious microorganisms was performed using the direct culture method. The concentration method using magnetic nanoparticles was compared with the centrifuge concentration method, which is frequently used in microbiology laboratories. A total of 500 CSF samples were studied. The concentration method with magnetic nanoparticles was tested on culture-negative CSF samples taken from suspected bacterial meningitis cases. Each sample was divided into two 1 mL portions. One portion was concentrated using centrifugation and the other using magnetic nanoparticles. After centrifugation and magnetic separation, the supernatants were cultured. No microorganism growth was observed in the supernatant concentrated with magnetic nanoparticles, while microorganism growth was observed in the supernatant concentrated using centrifugation. While centrifugation could not precipitate all microorganisms, magnetic nanoparticles captured and concentrated all microorganisms. After concentration with centrifugation and magnetic nanoparticles, the solid part remaining after separating the supernatant was cultured. No microorganism growth was observed in the culture medium with centrifugation, while microorganism growth was observed with magnetic nanoparticles. Incorrect results from low-density samples concentrated using centrifugation can hinder treatment. Therefore, the concentration method using magnetic nanoparticles is an easy, inexpensive, and simple method to apply for suspected meningitis patients, as it can concentrate samples less than 1 mL and trace levels of microorganisms.

Environmental sustainability and resource efficiency are of paramount concern in today's world. One underexplored area of sustainability lies in the valorization of agricultural wastes for the manufacturing of cellulose nanomaterials, which has relevance in several fields such as food packaging, biomedical, electronics, textiles, and several others. Considering the growing demand and variety of application, this study aims to develop environmentally friendly strategies by employing water as solvents under high-pressure fluid conditions to synthesize cellulose nanomaterials from agricultural waste. The influence of pressure (up to 150 bar), temperature (up to 200°C), and extraction time (up to 2 h) on synthesis efficiency and product quality was investigated. Results revealed that the resulting cellulose nanomaterials exhibited desirable properties with more than 50% of the particles having a size of less than 100 nm. Furthermore, a zeta potential of less than -30 mV and a polydispersity index of less than 0.5 indicate the stable and efficient dispersion of cellulose nanomaterials in water. Furthermore, the cellulose nanomaterials exhibited a crystallinity index below 70%, suggesting that the nanomaterials were present in the form of cellulose nanofibers. The XRD and FTIR characterization further revealed that the cellulose nanomaterials possessed the structure of type I cellulose. The structural characteristics of cellulose nanofibers were verified using scanning electron microscopy. In conclusion, the developed method successfully enables the manufacturing of high-quality cellulose nanomaterials. This study contributes substantially to the realization of sustainable conversion technologies for agricultural waste and supports the move towards a circular bioeconomy.

Cereal residues play a critical role in biomass sustainability by offering significant advantages in resource utilization and environmental impact reduction. These byproducts of agricultural activities are produced in significant amounts and can be an important source for the extraction of lignocellulosic biomaterials. In cereal waste, biomaterials such as cellulose, hemicellulose, and lignin are prevalent. To extract these materials, it is necessary to disassemble the complex structure of the biomass in order to release and recover the various constituents. Therefore, this work aimed to develop choline chloride-based novel aqueous deep eutectic solvents for fractionating and recovering individual lignocellulosic biomaterials from cereal waste. The treatment was carried out for up to 5 h at 80°C in an ultrasound bath. Results showed that cellulose content in the treated sample increased to almost 80% compared to around 42% in raw biomass. However, with the increased water content in the solvent from 10% to 30%, the cellulose content in the treated sample was reduced. After purification of the sample at the optimized conditions, the yield of cellulosic biomaterials was found to be in the range of 40 – 45% with a purity of more than 85%. Similarly, the solubilization of lignin reduced with the increase in water content in the solvent. Maximum lignin solubilization of around 75% was achieved with the solvent containing less water. Furthermore, more than 80% hemicellulose solubilization was observed in all experimental conditions. This work indicated that the developed solvent extraction process could efficiently recover valuable lignocellulosic biomaterials from cereal waste. The extraction of biomaterials not only enables the effective usage of cereal residue but also helps to promote a more eco-friendly and resource-efficient bioeconomy.

We observe the effect of AC voltage electrowetting on aqueous salt solutions with different conductivities. Also, we evaluate the validity of the Young--Lippmann equation when applied to both deionized (DI) and conducting water droplets on a hydrophobic Teflon surface. Through analysing rescaled electrowetting responses, we determine that the optimal conductivity for aqueous solutions, where electrowetting curves demonstrate linearity and ideal behaviour, is approximately ≥ 0.1 mS/cm. Additionally, we delve into the notion of "characteristic time" or "dielectric relaxation time", representing how long it takes for charge to reach the surface of the aqueous droplet. This characteristic time is theoretically calculated from Maxwell’s equation and the continuity equation for free charge, and experimental verification is conducted using electrowetting on aqueous drops of varying conductivities on a hydrophobic Teflon surface. We find that the characteristic time becomes negligible for conductivity σ ≥ 0.134 mS/cm, thus establishing an optimal aqueous conductivity of around 0.1 mS/cm for electrowetting studies. Furthermore, we present graphical representations of electrowetting responses with increasing carrier AC voltage frequencies.

Ionic liquids are now established as an interesting and highly diverse class of materials with interesting application profiles in chemistry, biology, and engineering. Over the last decade, we have established halidometallates as interesting and highly versatile building blocks for the design of ionic liquids and ionic solids with often highly specific properties. Examples include materials with tunable band gaps or materials with tunable (mostly ionic) conductivities in both the liquid and the solid state. The presentation will highlight some examples and demonstrate how the combination of specific metals with specific anions (halides in the current case) affect the color, the band gap, and the electrochemical properties. Moreover, the presentation will also show how zwitterion-based ionic liquids can be used for ion transport and for the electrodeposition of technologocally relevant lements.

Climate change has led to an increase in building energy costs, and, hence, it is vital to enhance building thermal energy efficiency. Thermochromic coatings, e.g., those based on VO₂, have great potential in this regard due to their ability to autonomously switch between absorptive and reflective states in response to cold or hot weather, respectively. However, developing a large-scale process for preparing VO₂ particles and achieving good durability in practical application are still challenging. In this work, we successfully prepared tungsten-doped VO₂ particles with a lower phase change temperature at 29.4 ^oC using a novel one-step pressure-assisted hydrothermal method, which provides a promising way for its large-scale preparation and application. In order to achieve better durability, we constructed ZnO shells for VO₂ particles, and the obtained VO₂@ZnO core-shell particles showed a better antioxidation performance. Furthermore, we designed a VO₂ coating formula with good hydrophobicity (a contact angle of 108.8^o) and adhesion with concrete by adding a certain ratio of PDMS and epoxy, endowing the coating with self-cleaning properties and application potential on building surfaces. This work proposes a high-efficiency hydrothermal preparation method for VO₂ particles and improves the durability of VO₂ coatings, providing a sustainable solution to energy-saving coatings for construction.