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Electron/phonon heat co-transfer, dielectric/magnetic dual loss, and 2D interlinked frameworks codetermine the ultrawide absorption bands, high thermal conductivity, and excellent electrical insulation of CF/M/C (M = Co, Ni, or Fe/Fe 3 O 4) 2D interlinked frameworks. [Display omitted] • A facile soaking-annealing strategy for CF/M/C (M = Co, Ni, Fe/Fe 3 O 4) 2DIFs. • Precisely modulating the interfaces, porosity, and defects. • Optimizing the thermal, electrical, and EMW absorbing properties. • Revealing the synergistic enhancement mechanism. Reasonable design of protective multifunctional materials is highly required for the safety protection of devices/personnel from electromagnetic radiation and heat damage in the 5G/6G era. Herein, a simple soaking-annealing route was adopted to carbonize filter paper into 2D interlinked carbon fiber frameworks inlaid with magnetic nanoparticles, and the products were referred to as CF/M/C 2DIFs (M = Co, Ni, or Fe/Fe 3 O 4). The concentration and type of metal ions as well as the annealing temperature of the CF/M/C 2DIFs were controlled to precisely modulate their composition, porosity, and defects. Results show that the CF/Co/C 2DIFs produced under T a = 600 °C and [Co2+] = 0.45 mol/L exhibit high thermal conductivity (2.931 ∼ 3.167 W/m·K) at small loads (10 ∼ 30 wt%) owing to not merely the presence of 2D interlinked path for electron/phonon heat co-transfer but the reasonable control of interface/defects for weakening phonon/electron defect/interface scattering. Also, the CF/Co/C 2DIFs can attenuate microwaves over a broad frequency range via dielectric/magnetic dual loss and 2DIFs, which boosts their loss ability and matching performance. The excellent performance in both heat dissipation and EM wave absorption proves that the CF/M/C 2DIFs can be a promising candidate for next-generation electronic packaging materials in heat management, military, and aerospace fields. [ABSTRACT FROM AUTHOR]

High pressure laminate has a key role at the protection of wood-based panels. Borax and recycled papers can be used for production of high pressure laminate which may impart the multitude effects. The readily availability of waste papers and borax may be a useful alternative to expensive papers with high quality, and also can compensate the strength losses of recycled papers. The recycled paper and borax are relatively inexpensive and environmentally friendly, and this results the production of not only a cleaner product but also provides an excellent performance against applied load, humidity and high temperature. In this study, three types of waste papers including newsprint, writing and paperboard were first recycled to be used for production of high pressure laminate. Phenol formaldehyde and borax were utilized to improve the strength and fire retardancy of high pressure laminate. Bending resistance, flame resistance and water absorption of high pressure laminate samples were tested. The results of the experiments showed that high pressure laminate made of recycled newspaper and borax had a superior performance when compared to samples that made from writing paper and paperboard. For example, an increase up to 1.4 times was observed in the bending resistance. The mixing of borax with resin increased the strength of high pressure laminate at 95 percent confidence level. The amount of water absorption after 2 h, bending resistance, glowing time and char length of high pressure laminate with recycled newspaper and borax were equal to 14%, 41 mNm, 37 s and 0.7 cm, respectively. The bending strength of coated particleboard with this overlay increased up to 1.5 times. High pressure laminate produced from recycled paper and borax was introduced as an environmentally acceptable product. [ABSTRACT FROM AUTHOR]

Developing separation materials for rapidly oil absorption and emulsions separation is urgently needed and remains a great challenge. Here, a biomass-derived banana peel/waste paper (BPWP) hybrid aerogel with hierarchical porous structure has been successfully fabricated via combination of freezing-cast, freeze-drying and pyrolysis approach, for application in oil adsorption and water-in-oil emulsions separation. In this hybrid system, the microsheets that derived from banana peel immobilize were immobilized on surface of the waste paper fibers, forming a hierarchical structure. The resulting BPWP aerogels exhibit a compression strain of 75%, high-hydrophobicity (WCA of 149.3°)/underair superoleophilicity (OCA of 0°), and high porosity, which can absorb of free oils in water with high oil sorption capacity of 35–115 times its own weight. Moreover, these aerogels effectively separate various surfactant-stabilized water-in-oil emulsions driven solely by gravity, with high separation efficiency above 99.6% and higher fluxes of up to 8550 L m −2 h −1 than traditional filtration membranes with pressure driven, even the sizes of emulsified droplets are smaller than the pore size of the BPWP aerogels. More importantly, the BPWP aerogels exhibit a superior antifouling property and regenerability for emulsion separation, which match well with the requirements for treating the real emulsions. Due to the advantages of banana peel/waste paper aerogels in rich source and high oil separation efficiency, the obtained banana peel/waste paper aerogel can be a potential candidate in industrial applications and environmental protection. This work opens up a new avenue for design new hierarchical biomass-derived aerogels for a variety of applications including energy storage, sensors and pressure-sensitive electronics. [ABSTRACT FROM AUTHOR]

Reduced graphene oxide (RGO) and magnetic metal oxide composite papers are high needed in microwave absorption, shielding and rapid electrical heating. Herein, a self-assembled multifunctional RGO/MnFe 2 O 4 paper is effectively prepared by a simple method of solution casting and thermal reduction for electromagnetic shielding, microwave absorption, temperature-sensing, electrothermal de-icing. A fast electrical heating is achieved, a saturation temperature of 100.2 °C can be provided within 15 s at a constant current of 0.35 A. In addition, the composite paper under a thermal reduction temperature of 800 °C gives an electromagnetic shielding efficiency (SE) value of 29 dB at X-band and a reflection loss (RL) of 43.2 dB at 14.1 GHz with a thickness of 3 mm and an effective bandwidth (RL < −10 dB) from 10.5 to 16.2 GHz. More, the contact resistance between the graphene-based paper and electrode is decoupled based on the equivalent circuit model, which is greatly contribute to its higher electrothermal and other electrical performance. And the contact resistance is 19.18 Ω, which accounts for 15% of the total resistance of the RGO/MnFe 2 O 4 composite. This RGO/MnFe 2 O 4 paper can offer great potential for fast electrical heater, high performance microwave absorbing and shielding materials. [Display omitted] • A self-assembled RGO/MnFe 2 O 4 paper is prepared by a simple method of solution casting and thermal reduction. • The performance of electromagnetic shielding, microwave absorption, electrothermal de-icing are investigated carefully. • The process of graphene-based films is relatively simple and can be widely used. • Decoupling based on the equivalent circuit model shows the contact resistance between the graphene-based film and electrode. • This work can provide useful values for high performance microwave absorberand fast electrical heater. [ABSTRACT FROM AUTHOR]

• Paper sludge ash-based stabilizer (PSAS) is a new type of soil stabilizer. • The W ab and PSD of PSAS influence the change in consistency PSAS-treated soil. • The q c of PSAS-treated soil can be estimated based on its liquidity index I L. • Required PSAS amount for a specific q c of PSAS-treated soil can be estimated. Paper sludge ash-based stabilizers (PSASs) have recently been developed in Japan as sustainable construction materials for soil stabilization. PSASs are produced by the in-solubilization of heavy metals in paper sludge (PS), which is generated as a by-product of the de-inking and re-pulping of paper. PSASs can improve the stability of high-water-content clays immediately after mixing owing to their good water absorption and retention performance. However, mixture design methods that consider time variations of the water absorption and retention performance of a PSAS are lacking. Therefore, in this study, the effects of a PSAS on the physical and mechanical properties of the treated clay were experimentally investigated, considering the change in the water absorption and retention performance of the PSAS with curing time. The water absorption and retention rate, W ab , of the PSAS, is defined as the ratio of the mass of water absorbed and retained by the PSAS to its dry mass. Physical tests and cone index tests were conducted on different types of clays treated with different types of PSASs. The test results showed that different W ab values were obtained depending on the type of the PSAS and that the W ab value increased with curing time. From the experiments, it was found that the liquid limits, w L , and plastic limits, w P , of the PSAS-treated clays with different curing times could be evaluated from the W ab values of the PSAS and the particle sizes of the PSAS and untreated clays. A clear correlation was also found between the cone index, q c , and liquidity index, I L , of the treated and untreated clays. Based on the results, a new approach for mixture design was proposed. The applicability of the proposed method was investigated, and the results showed that the measured q c value of the PSAS-treated clay was close to the target q c value. The average measured q c was approximately 1.1 times the corresponding target q c. The maximum error between the measured q c and target q c values was approximately 30%. [ABSTRACT FROM AUTHOR]

We have performed FTIR transmission microspectroscopy on graphene oxide papers oriented with the nominal lattice planes parallel to the infrared optical axis. By polarising the IR light for samples of this geometry, spectral contributions of oriented oxide species are isolated from broad convoluted bands. Analysing the data alongside previous works, including experiments where samples were perturbed by reduction, dehydration and deuteration, we tabulate the most likely assignments for the observed spectral bands. [ABSTRACT FROM AUTHOR]

[Display omitted] • Rime-like carbon paper@Bi 2 S 3 hybrid structure was fabricated by a facile strategy. • The morphology and microwave absorption performance can be easily tuned. • Strong and broadband absorption was realized at a low filler content (5 wt%). Although metal chalcogenides have been widely utilized as microwave absorbers, it remains a challenge for them to achieve efficient and broadband absorption performance with low filler content. Herein, a series of rime-like carbon paper@Bi 2 S 3 hybrid structures are manufactured by a facile one-step solvothermal process, whose morphology and microwave absorption properties also can be easily adjusted by the dosage control of raw materials. The Bi 2 S 3 clusters are grown densely on the surface of carbon paper fibers, like the rime in winter. The collocation of carbon paper and Bi 2 S 3 is beneficial to impedance matching and synergistically enhances microwave absorption capability based on various attenuation mechanisms, including interfacial/dipolar polarization loss, conduction loss, and multiple reflection. At a low filler content (only 5 wt%), the optimal reflection loss among these composites is −56.63 dB at 8.84 GHz with 3.3 mm thickness, and the broadest efficient absorption bandwidth is 7.32 GHz with a thickness of 2.4 mm, covering the whole Ku band. By adjusting the thickness, the total covered frequency range reaches 13.36 GHz (83.5% of 2–18 GHz). The as-prepared materials have unique microstructure and exhibit strong and broadband absorption performance with thin thickness and low filler content, enlightening future exploration of metal chalcogenides on high-quality microwave absorbers. [ABSTRACT FROM AUTHOR]

This paper investigates the collapse behavior of square paper tubes and the influence of tensile-compressive yield asymmetries of paper tube materials by combining the theoretical and experimental methods. An approximate energy absorption theoretical model is developed to predict the mean crushing force of square paper tubes subjected to axial loading. Besides, combined with the remarkable linear regularity of the experimental results, the numerical curve of the effective crushing distance ratio of paper tubes is obtained to improve the applicability of the proposed model. Then the theoretical results taking account of effective crushing distance are in excellent agreement with the experimental results. The proposed model can be used not only for the prediction of energy absorption characteristics of paper tubes in a logistics environment, but also to guide the protective packaging structure design with paper tubes. • The collapse behavior of square paper tubes under quasi-static compression is studied. • The influence of tensile-compressive yield asymmetries of paper tube materials. • A theoretical model is proposed to predict the mean crushing force of paper tubes. • An effective crushing distance curve is obtained to improve the model accuracy. • The theoretical predictions are in good agreement with experimental results. [ABSTRACT FROM AUTHOR]

This review is based on the radar cross-section (RCS) reduction techniques, with the prominence of the metasurface and its design. The thorough detail starts with introducing the concepts of the RCS and its reduction techniques. Then, traditional and recent techniques are provided to reduce RCS, emphasizing the scattering and absorption methods. An in-depth analysis of shaping processes and Radar Absorbing Materials (RAM) is provided, which are two standard RCS reduction techniques. It also thoroughly analyses the metamaterial-based RCS reduction, considering both active and passive configurations. The primary aspects covered regarding the utilization of metasurfaces for reducing RCS include profile, conformality, polarization sensitivity, and design complexity. To provide comparison and evaluation, the review includes tabulated information on performance parameters such as the method used, frequency range, size, optimization method, and planar or conformal design of RCS reduction. Additionally, the paper identifies areas within the field that require further in-depth research and investigation. [ABSTRACT FROM AUTHOR]

Ti 3 C 2 T x MXene has been regarded as a promising candidate for advanced microwave absorption materials. However, the microwave absorbing performance of Ti 3 C 2 T x MXene is suppressed by the single dielectric loss mechanism and impedance mismatch because of the high conductivity. To effectuate a good absorption capability of Ti 3 C 2 T x MXene, this paper constructs a heterostructured Co/Ti 3 C 2 T x hybrid by atomic layer deposition of magnetic Co nanoparticles on Ti 3 C 2 T x nanosheets. The microstructures, magnetism, and microwave absorption behaviors of the Co/Ti 3 C 2 T x hybrids are investigated systematically. The results show that the frequency-dependent electromagnetic parameters of the Ti 3 C 2 T x MXene become tunable by controlling the content of Co decorations, which are conducive to both magnetic loss and impedance matching. The Co/Ti 3 C 2 T x hybrid with ultralow Co decoration content (only 1.52 wt%) achieves the minimum reflect loss of −54.32 dB at a thin matched thickness of 1.29 mm, and the corresponding effective absorption bandwidth with reflection loss below −10 dB reaches 4.29 GHz. The atomic layer deposited magnetic metal nanostructures provides an effective strategy for preparing MXene-based hybrids which not only have high absorption efficiency but also significantly reduce the use of magnetic metals. [ABSTRACT FROM AUTHOR]

In this paper, layered porous SiC scaffolds were prepared by freeze casting and sintering, and then followed by loading polypyrrole (PPy) on its surface by in-situ polymerization to obtain porous SiC/PPy composites with different PPy content. The loaded PPy forms a good three-dimensional (3D) conductive network, thus the electrical conductivity and the dielectric loss capability of the sample is improved. Moreover, the porous structure provides more SiC-PPy heterogeneous interfaces for charge accumulation, leading to interfacial polarization and relaxation, further enhancing the microwave absorption performance. Compared with pure SiC particles, SiC/PPy-25 shows an increase in the minimum reflection loss (RL) from −8.64 to −39.1 dB, effective absorption bandwidth (RL < −10 dB) of 4.72 GHz, and comparatively thinner matched thickness of 1.7 mm. We provide a microwave absorption material with simple synthesis, high efficiency and wide application prospect. [ABSTRACT FROM AUTHOR]

Silicon oxycarbide (SiOC) ceramics have been used to fabricate microwave-absorbing metastructures, demonstrating impressive absorption capabilities. However, SiOC ceramic metastructures with excellent performance require simple fabrication processes and appropriate mechanical and electromagnetic properties. In this study, a solvent-free photosensitive polysiloxane preceramic was developed by blending methoxy/hydroxy polysiloxanes with acrylates, with a ceramic yield of over 60% after curing using a novel two-step ultraviolet (UV)/thermal method. The composition and microstructure of SiOC ceramics can be designed by controlling the preceramic composition. Dense, crack-free gyroid-shellular shaped triple periodic minimal surface (GS-TPMS) electromagnetic metastructures were fabricated using digital light processing (DLP) 3D printing technology. By designing the porosity of the GS-TPMS structure to 51%, an effective absorption bandwidth that covers the X-band can be achieved at a thickness of 3.1 mm. The honeycomb structure, with a geometric density of 0.69 g/cm3, exhibited a high compressive strength of 107.05 MPa. This paper presents an efficient approach for the prompt and customized fabrication of lightweight ceramic metastructures with outstanding microwave absorption properties. • A solvent-free polysiloxane/acrylate hybrid preceramics is developed for 3D printing. • The UV/thermal two-stage treatment achieved cross-linking curing of the preceramics. • Multiscale design of SiOC ceramics for enhanced microwave absorption properties. • SiOC ceramic metastructures with effective absorption in the X-band are prepared. [ABSTRACT FROM AUTHOR]

• A numerical investigation of an evaporator of a diffusion-absorption-refrigeration system using computational fluid dynamics (CFD). • The CFD modelling is conducted by CONVERGE CFD software and was experimentally validated. • The study provides a deeper understanding of the evaporation process in DAR systems. • The study examined also the impact of ammonia presence at the hydrogen inlet on temperature distribution and overall, the accuracy of the CFD model. • The present study emphasizes the significance of utilizing CFD simulation to analyse and improve numerous processes, thus boosting the overall performance of the DAR system. The evaporation process has a considerable impact on the operation of a diffusion absorption refrigeration system (DAR). However, there have been few studies that have focused on this specific issue. In this paper, a numerical investigation of the evaporator region in a DAR system was conducted using CONVERGE CFD software and the RANS approach. The aim of this study is to validate an accurate CFD model by analysing the flow behaviour and thermal parameters within the evaporator. The computational results show high agreement with the experimental data, with slight deviations often remaining under 3 %. The current study additionally investigated the effect of ammonia presence at the hydrogen inlet, specifically at 5 % and 10 % ratios. The results demonstrate that the average deviation is less than 1 % when using 5 % ammonia. This study sheds light on the evaporation process, which is important for enhancing the design and operational efficiency of DAR systems. For this purpose, the validated numerical model will be of great use. [ABSTRACT FROM AUTHOR]

The establishment of a prediction model for the hydrogen absorption state of a solid-state hydrogen storage device is crucial for its practical application. In this paper, a solid-state hydrogen storage device filled with AB 2 hydrogen storage alloy is investigated. The experimental data are obtained by controlling the hydrogen absorption temperature and hydrogen absorption rate respectively. The Broyden-Fletcher-Goldfarb-Shanno algorithm (BFGS) is used to fit the solid-state hydrogen storage device experimental data based on the Richards model, and Linear Regression, Gradient Descent and Artificial Neural Network algorithms are used to predict the parameters of the Richards model. It is confirmed that the Linear Regression model has the best prediction effect after verified by the test set, with coefficients of determination R2 ≥ 0.96. This study provides an effective way to predict the hydrogen absorption state of solid-state hydrogen storage devices quickly. • The effects of temperature and rate on hydrogen absorption process of solid-state hydrogen storage device are studied. • Richards model is used to fit the hydrogen absorption curve shaped as an S-type. • The prediction model of hydrogen absorption process of the device is established. • Three machine learning algorithms are applied to establish the prediction model. [ABSTRACT FROM AUTHOR]

[Display omitted] • Fe 7 S 8 anchoring S-doped porous GE was successfully synthesized. • Rhodanine converted Fe 3 O 4 to Fe 7 S 8 and constructed porous S-doped GE. • Multi-band electromagnetic absorptions were realized, with effective bandwidth achieved up to 12.07 GHz. At present, research bottleneck on electromagnetic absorption materials lied in achieving strong absorption with broadband and multi-band responses. In this paper, Fe 7 S 8 anchoring S-doped porous graphene was synthesized for multi-band electromagnetic absorptions. Rhodanine played the role of 'two birds in one stone', converting Fe 3 O 4 to Fe 7 S 8 and constructing porous S-doped carbon. The hybrids exhibited multi-band electromagnetic absorptions at 10.52, 12.56 and 15.03 GHz, with effective bandwidth achieved up to 12.07 GHz. This paper showcases reference path for the design of multi-band electromagnetic absorption materials. [ABSTRACT FROM AUTHOR]

In March 2024 Construction and Building Materials published "Water distribution characteristics of capillary absorption in internally cured concrete with superabsorbent polymers", which claims to present a water distribution model characterising the spatiotemporal moisture content evolution in internally cured concrete with superabsorbent polymers during capillary absorption. This discussion, considered a post-publication critique, establishes that the paper's water distribution model conflicts with the paper's capillary absorption tests. While the model is based on the premise of the square-root-of-time behaviour of capillary absorption, the tests do not demonstrate that square-root-of-time behaviour. This critique in addition questions the paper's forthright application of the power-law diffusivity expression with exponent 4, given that its validity for the paper's materials has not been verified. It is shown that different but equivalent diffusivity expressions lead to different moisture diffusivities at lower moisture contents. • This post-publication review formulates concerns on a previously published paper. • The paper's water distribution model and capillary absorption tests are in conflict. • The paper's adoption of an unverified moisture diffusivity expression is doubtful. [ABSTRACT FROM AUTHOR]

In this paper, the hydrogen storage properties of the MmNi 4.6 Al 0.4 and MmNi 4.6 Fe 0.4 compounds are compared experimentally and theoretically. The experimental curves of the activation process, experimental isotherms of absorption and the Van't Hoff's plot were first investigated. Following that, a theoretical model is contrasted with the experimental data. The mathematical equations of this model contain parameters, such as the number of hydrogen atoms per site (n 1 , n 2), the densities of the receiving sites (N 1m , N 2m), and the energy parameters (P 1 , P 2). All these parameters are obtained by numerically adjusting the experimental data. Depending on the applied temperature, the relevant parameters of the suggested model were identified and described. Entropy, internal energy, and other thermodynamic variables that govern the absorption reaction were all calculated and displayed as a function of pressure and temperature. • Measurement of hydrogen absorption isotherms by MmNi 4.5 Al 0.4 and MmNi 4.6 Fe 0.4 compounds. • Validation of experimental data by a mathematical model using statistical physics. • Determination of the steric parameters governing the absorption reaction. • Calculation of the thermodynamic functions of the absorption reaction. [ABSTRACT FROM AUTHOR]

• This paper describes a Paxlovid PBPK Model that utilizes the ADAM module to better describe oral absorption of nirmatrelvir. • Rotamer conversion influences nirmatrelvir dissolution and absorption and was incorporated into the ADAM PBPK model. • PBPK model describes nirmatrelvir dissolution as a function of drug and drug product attributes, and physiological changes. • The Paxlovid ADAM PBPK model illustrates the importance of taking mechanistic approaches to model development. PAXLOVID™ is a combination medicine of nirmatrelvir tablets co-packaged with ritonavir tablets. Nirmatrelvir is a peptidomimetic inhibitor of SARS-CoV2 main protease (Mpro), developed for the treatment of COVID-19. Ritonavir is co-administered as a pharmacokinetics (PK) enhancer to inhibit CYP3A mediated metabolism increasing exposures of nirmatrelvir. In the solid form, nirmatrelvir exists in a stable single conformational state (ANTI form). However, nirmatrelvir exhibits atropisomerism in solution whereby upon dissolution the ANTI rotational isomer reversibly converts to another conformation state (SYN form). Nirmatrelvir rotamer conversion follows pseudo first order kinetics with a conversion half-life of approximately 15 min in aqueous solutions, which is on a similar time scale of diffusion mediated dissolution from the solid form. In vitro dissolution studies further indicated that rotamer conversion is one of the processes controlling nirmatrelvir dissolution. It was hypothesized that rotamer conversion kinetics would affect oral absorption of nirmatrelvir in vivo. Consequently, a physiologically based pharmacokinetic (PBPK) model for Paxlovid was developed in Simcyp™ using the advanced dissolution, absorption, and metabolism model (ADAM) by incorporating rotamer conversion kinetics to achieve a more mechanistic description of nirmatrelvir oral absorption. The results demonstrate that the established absorption model with rotamer kinetics adequately described observed clinical data from various nirmatrelvir doses, dosage forms, and dosing regimens. The predicted vs. observed AUC inf and C max ratios were within 2-fold. The model has been internally used to inform clinical studies and dose recommendations for pediatrics. [ABSTRACT FROM AUTHOR]

This review focuses on studying liquid flow through low-density fibrous porous media, particularly tissue grades of papers. It discusses experimental designs, factors affecting liquid flow, and various versions of the Lucas-Washburn equation and permeability expressions used to estimate liquid flow in these media. While a comprehensive model for liquid flow in these materials is lacking due to their structural complexity, numerous experimental methods have been developed to determine absorption properties, particularly for wiping and cleaning liquids. The review covers these methods, many of which are proposed by standard organizations. It is a valuable reference for scientists interested in understanding the models and methods associated with these materials. Manufacturers can also use this review to select and implement appropriate methods for the evaluation of absorption performance and quality of tissue products. • Explains the design of experiments and factors affecting the flow of liquid. • Covers liquid flow equations and permeability expressions. • Demonstrates experimental methods developed for absorption properties. • Serves as a comprehensive reference to evaluate absorption performance. [ABSTRACT FROM AUTHOR]

In this work, a method for total sulphur determination in automotive gasoline using dried matrix spot sampling is proposed. The method is based on the deposition of the sample on a cellulose-based filter paper and subsequent sulphur quantification via CS diatomic molecule using high-resolution continuum source graphite furnace molecular absorption spectrometry (HR-CS GF MAS). The sample deposition was carried out, along with the chemical modifier, on a 20-mm filter paper disc previously adapted into a polytetrafluoroethylene (PTFE) mould. The liquid phase was removed by heating the PTFE mould, and then the gasoline sample-embedded filter paper was punched in smaller discs (procedure A) or pulverised (procedure B) before the analyses. The mixture of Pd and Mg was used as chemical modifier to stabilise the sulphur compounds on the filter paper and on the graphite furnace. All the calibration curves constructed using seven different sulphur-containing compounds had a coefficient of determination higher than 0.995 and a linear range from 2 to 150 mg kg−1 S. By using the optimised conditions, the best characteristic mass, limits of detection and quantitation were 6 ng, 0.6 and 1.8 mg kg−1, respectively. The two sampling procedures (A and B) were evaluated for real samples, and procedure B was chosen since it markedly improved the precision. Using this procedure, satisfactory recovery values from 95 to 106% were obtained in the spike-recovery tests. In addition, the S concentrations for the certified reference materials were not statistically different from the certified values at 95% confidence level. Sulphur concentrations from 20 to 46 mg kg−1 were found in the six analysed gasoline samples, and these values were statistically assessed using a reference method (ASTM 5453). Spectral interference caused by MgF and MgCl diatomic molecules was observed and investigated. [Display omitted] • Dried matrix spot (DMS) was applied for total sulphur determination in gasoline. • Quantification via CS diatomic molecule using HR-CS GF MAS. • Spectral interference caused by MgF and MgCl diatomic molecules was investigated. • Pd/Mg was used to stabilise the analyte on filter paper and on the graphite furnace. • Pulverised sample-embedded FP: grinding procedure improved the precision. [ABSTRACT FROM AUTHOR]

The electricity required for air conditioning is soaring worldwide. Absorption chillers represent an alternative to classical vapor compression systems, using heat instead of electricity. However, absorption chillers powered by renewable geothermal heat have received little attention so far. This paper introduces a system using a hot geothermal fluid (typically in the range of 80–110 °C) to produce cooling through a single-effect absorption chiller, and Domestic Hot Water (DHW) through a heat exchanger. It considers a hotel located in Martinique, a French Caribbean island. The electric consumption of every subsystem has been thoroughly estimated. The originality of this paper is twice: i) the system is modelled in TRNSYS software considering dynamic conditions, ii) the system undergoes surrogate modelling and multi-objective optimization to minimize both the cost and the CO 2 content of the delivered thermal energy. Several scenarios are considered, depending upon the geothermal temperature, mass flow rate, well remoteness, and demand size. The studied system appears to be systematically more expensive than a combination of a classical vapor compression chiller and a boiler for DHW. However, it can significantly decrease the CO 2 content of the provided energy, especially in an island where most electricity is generated from fossil fuels. The proximity of the geothermal well and the use of the warm water leaving the absorption generator (here for DHW production) appear to be key factors for system relevance, along with a hotter geothermal fluid (e.g., 110 °C instead of 80 °C). • A geothermal absorption chiller in tropical climate is modelled. • The influence of design parameters on electricity consumption is investigated. • The system undergoes multi-objective optimization. • The well proximity and geothermal temperature are keys to the system relevance. [ABSTRACT FROM AUTHOR]

Researchers have begun focusing on developing biodegradable materials, such as natural fiber/polymer composites (NFPC), since the growing of environmental concerns related to waste management. One crucial aspect that must be established in the development of these composites is their water-absorption behavior. This paper examines the water absorption (WA) behavior of NFPC, with a specific emphasis on natural fiber/polylactic acid (PLA) composites. It discusses processes and numerous aspects related to this behavior, based on recent published research. This review analyzes the influence of several factors, such as the loading of natural fiber, the combination of different natural fibers, the methods used in manufacturing, and the temperature of the water, on the WA behavior of natural fiber/PLA composites. It also explores how WA affects the properties of these composites. In addition, this review also presented techniques for improving the WA resistance of the composites. This review paper provides researchers with insights into the WA behavior of the composites, aiming to facilitate the development of a versatile and eco-friendly material that may effectively address waste disposal challenges. [ABSTRACT FROM AUTHOR]

• Novel falling film absorber with the atomizer installed at the bottom is proposed. • The absorption effect is enhanced by 10.5% after the installing of atomizer. • The improvement is affected by the inlet conditions of absorber. • The droplets parameters optimization can further increase the enhancement effect. As a typical absorption device, falling film absorber has a significant effect on the performance of the ammonia water absorption refrigeration system. In this paper, a novel absorber with atomizer installed at the bottom of the absorber is proposed. The atomizer is introduced to increase the effective mass transfer area between ammonia vapor and the solution. A theoretical model in established and simulation investigation is carried out to obtain the absorption enhancement by the atomizer. The result indicates that the enhancement is 10.5% with the 1 mm initial droplet diameter in the design point of this paper, and it can reach 34.2% when the initial droplet diameter is reduced to 0.2 mm. Furthermore, the optimization of enhancement effect by other droplet parameters has been analyzed. [ABSTRACT FROM AUTHOR]

This paper presents the catalytic effect of NaH doped nanocrystalline TiO 2 (designated as NaTiOxH) in the improvement of MgH 2 hydrogen storage properties. The catalyst preparation involves ball milling NaH with TiO 2 for 3 hr. The addition of 5 wt% NaTiOxH powder into MgH 2 reduces its operating temperature to ∼185 °C, which is ∼110 °C lower than the additive-free as-milled MgH 2. The composite remarkably desorbs ∼7.2 wt% H 2 within 15 min at ∼290 °C and reabsorbs ∼4.5 wt% H 2 in 45 min at room temperature under 50 bar H 2. MgH 2 dehydrogenation is activated at 57 kJ/mol by the catalyst. More importantly, the addition of 2.5 wt% NaTiOxH catalyst aids MgH 2 to reversibly produce ∼6.1 wt% H 2 upon 100 cycles within 475 hr at 300 °C. Microstructural investigation into the catalyzed MgH 2 composite reveals a firm contact existing between NaTiOxH and MgH 2 particles. Meanwhile, the NaTiOxH catalyst consists of catalytically active Ti 3 O 5 , and "rod-like" Na 2 Ti 3 O 7 species liberated in-situ during preparation; these active species could provide multiple hydrogen diffusion pathways for an improved MgH 2 sorption process. Furthermore, the elemental characterization identifies the reduced valence states of titanium (Ti<4+) which show some sort of reversibility consistent with H 2 insertion and removal. This phenomenon is believed to enhance the mobility of Mg/MgH 2 electrons by the creation and elimination of oxygen vacancies in the defective (TiO 2-x) catalyst. Our findings have therefore moved MgH 2 closer to practical applications. [ABSTRACT FROM AUTHOR]

Owing to their rapidly rising market share, TOPCon (poly-Si/SiO x passivating contact or POLO contact) solar cells, which are projected to surpass PERC as the dominant solar cell technology within the next decade. The TOPCon structure exhibits exceptional passivation and conductivity properties for both n+ and p + polarities, while also being compatible with conventional industrial production processes. However, a limit upon implementing poly-Si/SiO x passivated contacts is the potential for optical losses caused by parasitic absorption in the poly-Si layer, particularly when placed at the front of solar cells or at the back of bifacial solar cells in bifacial modules where light can be absorbed from both the front and the backside. This review paper provides a comprehensive review of innovations aiming to mitigate these losses. These include thinning, employing transparent conductive films, light element doping, and localizing poly-Si contacts. Through an exploration of these methods, the paper endeavours to offer valuable insights into optimizing the performance of solar cells utilizing the TOPCon structure. [ABSTRACT FROM AUTHOR]

The new staggered story isolation (NSSI) is a new type of isolation method developed based on base isolation (BI) and mid-story isolation (MSI). Different from ordinary ground motions, far-field long-period ground motions have the characteristics of long period, long duration, and rich low-frequency components, which will have adverse effects on structures with relatively large periods of isolation, which need to be discussed in depth. Based on this, this paper establishes a 16-story frame core tube structure, under rare earthquakes, adopts NSSI, and inputs 7 ordinary ground motions (OGM), 7 far-field anharmonic-like ground motions (FAGM), and 7 far-field harmonic-like ground motions (FHGM), the latter two are collectively referred to as far-field long-period ground motions (FLGM). The seismic response results are obtained through simulation, and the shock absorption performance is compared with non-isolated, BI, and MSI. Combined isolation is proposed, and its displacement-limiting effect under FLGM is discussed. The results show that the seismic responses of various structures under FLGM are much larger than those of OGM; the NSSI structure has better overall shock absorption performance and better safety performance under FLGM; The Combined isolation has a good displacement limiting effect under various ground motions, especially for FHGM, the displacement limiting effect is the best. • The new staggered story isolation (NSSI) is a new type of isolation method developed based on base isolation (BI) and mid-story isolation (MSI). • Different from ordinary ground motions, far-field long-period ground motions have the characteristics of long period, long duration, and rich low-frequency components, which will have adverse effects on structures with relatively large periods of isolation, which need to be discussed in depth. • This paper compares the differences in seismic response of different isolation methods and gives the applicability of various isolation methods. [ABSTRACT FROM AUTHOR]

ABO 3 type perovskite oxides have been widely studied due to their unique structure and special electromagnetic properties. CaMnO 3 is well known for its excellent thermoelectric performance and temperature stability. In this paper, Ca 1-x Gd x MnO 3 (x = 0, 0.1, 0.2, 0.3, 0.4) perovskites were comprehensively studied by first-principles calculations and experimental characterizations on their crystal structure and electromagnetic properties to finally elaborate the microwave absorption mechanism. It is found that Gd doping significantly enhances the dielectric polarization effects, resulting in better electromagnetic wave absorption performance than undoped CaMnO 3. Especially for CG2MO perovskite, its reflection loss and bandwidth below −10 dB at 2–18 GHz reaches −31.9 dB and 3.3 GHz approximately, exhibiting excellent microwave absorption property. Moreover, the microwave absorption mechanism of CGMO perovskites involves various modes of conductive loss, resonance loss, multiple reflection and scattering as well as the polarization phenomenon including interfacial polarization, dipole polarization and defect polarization. Among them, polarization effects and conductive loss contributes the most to the microwave absorption performance. [ABSTRACT FROM AUTHOR]

• The condensation of NH 3 /H 2 O with mass concentrations of 80%−96% is measured. • High concentration NH 3 /H 2 O shows the same flow pattern characteristics as pure NH 3. • The heat transfer coefficients decrease with lower mass concentrations. • The sensitivity of frictional pressure drop indicates separated flow. • The investigated parameters are mass concentration, vapor quality, mass flux, etc. High concentration NH 3 /H 2 O is suitable for Kalina cycles used for the recovery of low grade heat. Plate heat exchangers (PHEs) are compact and reduce the charge of working fluid. This paper investigates the condensation of NH 3 /H 2 O with NH 3 mass concentrations of 80%-96%. The vapor and liquid concentrations are close to equilibrium state, which are different from normal absorbers. The apparent heat transfer coefficients (HTCs) and frictional pressure drop are presented, covering the mass fluxes of 32–86 kgm−2s−1, the averaged vapor qualities of 0.08–0.65 and the saturated pressure of 610 to 780 kPa. Larger mass fluxes noticeably increase the apparent HTCs and frictional pressure drop. At the mass concentrations of 96%, 91% and 88%, higher vapor qualities increase the apparent HTCs for large mass fluxes. The apparent HTCs decrease slightly with vapor qualities for 80% mass concentration. The experimental results are compared with those of pure NH 3. The flow patterns of high concentration NH 3 /H 2 O are considered as full film flow and partial film flow, which are the same as for NH 3. The mass transfer resistance deteriorates the heat transfer especially for partial film flow, which happens at small liquid mass fluxes. The mass transfer resistance has negligible influences on frictional pressure drop. [ABSTRACT FROM AUTHOR]

Acoustic absorption and thermal insulation play a key role in modern buildings to make living comfortable and energy-saving. This paper aims to study the workability, physical and mechanical properties, thermal conductivity, and acoustic absorption of modified geopolymer concrete (GPC) with various types of lightweight aggregates (LWA) such as extruded polystyrene foam beads waste (EPS), vermiculite, or lightweight expanded clay aggregate (LECA). The mixtures of geopolymer concrete have been modified by substituting for the ordinary aggregates (dolomite) by volume with various ratios of 0, 25, 50, 75, and 100% for each type of LWA. Besides, the mechanisms of specimens were examined by scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), and mapping. The results illustrated that the compressive strength values range between 8.5 and 47.50 MPa. The hardened density of concrete was between 1500 and 2450 kg/m3, and thermal conductivity was between 0.45 and 1.16 W/m.K. Geopolymer concrete was considered an acoustic absorption and thermally insulating material. Geopolymer concrete was considered an acoustic absorption and thermally insulating material. EPS, vermiculite, and LECA will be beneficial for applications in lightweight geopolymer concrete due to their capability to reduce weight and excellent thermal conductivity, and the property of improving acoustic absorption. The mechanical results indicated that 25% LECA was the best compared with the ratios of other LWA and gained 35.0, 2.7, and 4.3 MPa of compressive, splitting tensile and flexural strength, respectively. It had positive workability; the thermal conductivity was 1.1 W/m.K, and hardened density was decreased to 10% compared to the control. In addition, LECA is considered the superior and suitable material for acoustic absorption compared with other aggregates. [ABSTRACT FROM AUTHOR]

Hydrogen storage alloys are usually susceptible to poisoning by O 2 , CO, CO 2 , etc., which decreases the hydrogen storage property sharply. In this paper, the adsorption characteristics of oxygen on the ZrCo(110) surface were investigated, and the effect of oxygen occupying an active site on the surface on the hydrogen adsorption behavior was discussed. The results show that the dissociation barrier of H 2 is increased by more than 26% after O occupies the active sites on the ZrCo(110) surface, and the probability of H 2 adsorption and dissociation decreases significantly. The adsorption energy of H atoms on the O–ZrCo(110) surface decreased by 18–56%, and the adsorption stability of H decreased. In addition, H atom diffusion on the surface and into bulk are prevented with higher reaction energetic barriers by O occupying active sites. Eventually, the ability of the ZrCo surface to adsorb hydrogen is seriously reduced. [Display omitted] • Oxygen molecules are easily adsorbed and dissociated on the ZrCo surface. • The O atoms stably occupy active sites on the ZrCo surface. • The O atoms reduce the adsorption and dissociation ability of H 2 on ZrCo surface. • The O atoms hinder that diffusion and inward penetration of H on ZrCo surface. [ABSTRACT FROM AUTHOR]

• Combination of the absorption and vapor compression heat pump. • Maximum performance enhancements for heating is 45.8%. • Maximum performance enhancements for cooling is 18.9%. • Power savings for heating and cooling are 16.0% and 31.4%, respectively. • Lower the heat-driven temperature for absorption to 60 °C. Decarbonizing the energy sector becomes a key topic to solving man-made climate change. For achieving indoor thermal comfort conditions, conventional heating, ventilating, and air-conditioning systems consume so much energy in both residential and public buildings. In this paper, a novel solar-assisted absorption-compression system for both heating and cooling is proposed to utilize solar thermal energy throughout the year for the heating/cooling supply. The experimental prototype was built and operational modes including solar-assisted heating/cooling mode and vapor compression individual heating/cooling mode. The performance enhanced by assisted heat input of the proposed system is evaluated by comparing it with air-source heat pumps operated under the same ambient conditions. Performance indices consisting of COP ele increment, power-saving ratio (PSR) and energy-saving ratio (ESR) are presented. The results indicate that the combination of the absorption heat pump subsystem and the vapor compression subsystem lowers the heat-driven temperature to 60 °C and thus makes higher solar collection efficiency possible. The maximum of the COP ele increment and the PSR under solar-assisted heating mode are achieved at conditions with 80 °C hot water temperature, of 45.8% and 31.4%, respectively, and the corresponding value for solar-assisted cooling mode are 18.9% and 16.0%. The speed of compressor as well as fan frequency of terminal has a greater influence on heating performance that on cooling performance due to the different coupling mechanisms. [ABSTRACT FROM AUTHOR]

A recent paper titled "A continuous hydrogen absorption/desorption model for metal hydride reactor coupled with PCM as heat management and its application in the fuel cell power system", published in the International Journal of Hydrogen Energy, describes the desorption kinetics modification without which the authors of this paper was unable to obtain experimental dependencies in the simulation during desorption. According to the opinion of the author of this commentary, modification of the kinetics is not required, and experimental results can be obtained using the standard kinetics by replacing the inlet/outlet boundary condition with a better one. [ABSTRACT FROM AUTHOR]

To satisfy the growing demand for military and civil applications, it is necessary to develop high-efficiency microwave-absorbing materials. Herein, a pyrolysis process was developed to construct FeO x /Fe/C composites using filter papers saturated with ferric nitrate solution as the precursor. The three-dimensional textures of filter paper are well maintained during the pyrolysis process. Ferric nitrate is decomposed to Fe 2 O 3 and subsequently reduced to Fe 3 O 4 and Fe nanoparticles embedded in the carbon matrix via carbothermal reduction. Various gases produced during the pyrolysis process create foam and generate additional nanoscale pores in the carbon matrix. The chemical composition and structure of composites can be tailored by controlling the pyrolysis conditions. The microwave absorption properties of FeO x /Fe/C composites are closely related to the chemical composition and structure. The optimized product shows excellent microwave absorption properties: The strongest reflection loss (RL) is −37 dB at ∼12 GHz; the effective absorption bandwidth (RL < −10 dB) is 6.5 GHz with a thickness of 2.0 mm. The superior absorption properties of the optimized product can be ascribed to the synergies of multiple chemical components, hierarchically porous structures and abundant interfaces. This study also suggests a large-scale synthesis strategy for high-yield carbon-coated magnetic nanoparticles for high-performance microwave absorption materials. Image 1 • A pyrolysis process was developed to construct porous FeO x /Fe/C composites. • Magnetic nanoparticles are embedded in the porous carbon matrix. • The chemical composition and structure can be tailored by controlling the pyrolysis. • The microwave absorption properties are closely related to the composition and structure. • The effective absorption bandwidth of the optimized sample is 6.5 GHz with a thickness of 2.0 mm. [ABSTRACT FROM AUTHOR]

• Energy absorption of circular tubes with non-uniform grooves is investigated. • Gradiently grooved tube is advantageous for energy absorption under the oblique loading. • Critical loading angle increases significantly with the introduction of the grooves. • Deformation mode transits from global bending to progressive folding as friction increases. Compared with the excellent energy absorption performance under axial loading, thin-walled tubes are vulnerable to instable global bending under oblique loading condition. In this paper, a novel design was developed to improve the energy absorption performance of the thin-walled circular tubes under oblique loading by introducing multiple circumferential grooves with non-uniform depths. Quasi-static experiments and finite element simulations were carried out for tube specimens with different groove configurations. Theoretical models were developed to explain the different energy absorption performance of different tubes. The effects of the loading angle and the friction condition on the energy absorption were also investigated. The results highlight the advantages of the gradiently grooved tubes with groove depth decreasing from loading end to fixed end over the uniformly grooved tubes and the original tubes under the oblique loading condition. The work in this paper can provide a guide for the design of advanced energy absorbing devices for arbitrary loading condition. [ABSTRACT FROM AUTHOR]

• Applying the Rate-Based Model to provide an accurate prediction of CO 2 absorption by MDEA + PZ in real and industrial conditions. • Introducing the Billet-Schultes mass transfer model as the most appropriate model in the CO 2 absorption process by MDEA + PZ. • Sensitivity analysis in industrial conditions with the aim of replacing MDEA + PZ with benchmark solvent such as MEA. • At optimum conditions, the rich solvent temperature by MDEA + PZ, 6.37 °C is higher than the MEA. • By optimizing the parameters, the absorption percentage with MDEA + PZ can be raised to 87.44 % compared to 82.86 for MEA. The goal of the study is to assess the use of MDEA + PZ in place of MEA solvent in industrial conditions. In the first part of the paper, a concise package of the models and the correlations in the Rate-based model is introduced to simulate the capture processes. For this purpose, Onda, Bravo-Fair, and, Billet-Schultes mass transfer correlations are evaluated to determine the one with a precise prediction of CO 2 absorption. The results show that Bravo-Fair mass transfer correlation has a lower average error, 10.24 %, compared to Onda, 16.41 %, and Billet-Schultes, 27.02 %. In the second part of this paper, different operational and process sensitivity analyses have been performed to investigate the capabilities of the MDEA + PZ in place of the prevalent solvents such as MEA in the industrial environment with the use of the data obtained from Kermanshah petrochemical's Carbon Dioxide Recovery plant (CDR). According to the sensitivity analysis, which determines the influence of design parameters and operational conditions on CO 2 absorption percentage, rich solvent temperature, liquid temperature profile, and CO 2 mole fraction profile in the gas phase inside the CO 2 absorption tower, the total solvent concentration is the most influential one in CO 2 absorption (%) and rich solvent temperature (°C). Hence, in optimal conditions, the absorption percentage can be raised from the base case 64.62 % to 87.44 % for MDEA + PZ compared to 82.86 of MEA. In addition, the rich solvent temperature can be lifted to 53.61 °C in comparison with 47.24 °C for MEA. [ABSTRACT FROM AUTHOR]

In this paper we study the non-flux chemotaxis system: u t = Δ u − χ ∇ ⋅ (u v ∇ v) + b u − μ u 2 , v t = Δ v − u v , in a bounded and smooth domain Ω ⊂ R 2 , with b ∈ R and χ , μ > 0. The existing literature, on the premise of relatively weak cross-diffusion with 0 < χ < 1 , has established the global existence of classical solutions for arbitrary μ > 0. In the present paper, we extend to prove that for any χ ≥ 1 , there exists μ ∗ (χ) > 0 such that whenever μ > μ ∗ (χ) , any reasonably smooth initial data emanates a unique global classical solution. Moreover, it is shown that there exist α (Ω) > 0 and β (Ω) > 0 such that when b > 0 , if μ > α (Ω) b + β (Ω) for 0 < χ < 1 , or μ > max { μ ∗ (χ) , α (Ω) b + β (Ω) } for χ ≥ 1 , then any classical solution must be globally bounded with the convergence that (u (⋅ , t) , | ∇ v (⋅ , t) | v (⋅ , t) , v (⋅ , t)) → (b μ , 0 , 0) in [ L ∞ (Ω) ] 3 as t → ∞. Instead, when b ≤ 0 , all classical solutions remain uniformly bounded in time as long as μ > 0 for 0 < χ < 1 , or μ > μ ∗ (χ) for χ ≥ 1 , and it also holds that (u (⋅ , t) , | ∇ v (⋅ , t) | v (⋅ , t) , v (⋅ , t)) → (0 , 0 , λ) in [ L ∞ (Ω) ] 3 as t → ∞ with 0 ≤ λ < 1 | Ω | ∫ Ω v (⋅ , 0). [ABSTRACT FROM AUTHOR]

[Display omitted] • MXene/bimetallic CoNi-MOF derived M/CoNi/C series composites were fabricated by in situ synthesis and pyrolysis. • The composites exhibited excellent MWA performance with RL min of −61.34 dB at 1.9 mm and the EAB of 5.2 GHz at 1.7 mm. • The morphology and EM parameters were modulated by adjusting the molar ratio of Co2+/Ni2+ and addition amount of MXene. The development of high-performance microwave-absorbing materials (MAMs) to address electromagnetic (EM) pollution has become a focus of attention for researchers. The combination of MXene and heterogeneous MOF with complementary advantages can be designed into novel composites with promising microwave absorption (MWA) properties. In this paper, the M/CoNi/C series composites derived from MXene/CoNi-MOF were prepared by in situ hydrothermal-pyrolysis process. The effects of the molar ratio of Co2+/Ni2+ and the addition amount of MXene on the morphology and EM parameters of the composites were investigated, and then the MWA performance and mechanisms of M/CoNi/C composites were analyzed. The results showed that the uniformly distributed CoNi and graphitic carbon in the M/CoNi/C composites formed a core–shell structure, and TiO 2 nanoparticles modified on the carbon lamellas originated from MXene. The minimum reflection loss (RL min) value of the optimized M/Co 1 Ni 1 /C reaches −61.34 dB only at the thickness of 1.9 mm, and the effective absorption bandwidth (EAB) value is 5.2 GHz only at 1.7 mm. The RL min values in the thickness range of 1.5–3.0 mm are all less than −30 dB. The tunable microstructures, multiple interfacial polarizations, and dielectric-magnetic synergies optimize the impedance matching, which is conducive to achieving good broadband EM wave absorption performance. This paper provides a reference strategy for the design and construction of a high-performance MXene-based microwave absorber with controllable morphology and electromagnetic parameters. [ABSTRACT FROM AUTHOR]

With the widespread application of radar detection systems in the military field, the development of radar stealth technology can effectively reduce the characteristic signals of targets, which was of great significance for the protection of important military targets. In this paper, the resorcinol/formaldehyde (RF) reinforced silica aerogel (RF/SiO 2) was synthesized successfully. The RF was introduced into the sol/gel technology to build a porous skeleton, and the SiO 2 aerogel was prepared by atmospheric pressure drying. The RF/SiO 2 aerogel was then heat treated, and the microstructure and physical properties of the RF/SiO 2 aerogel before and after heat treatment were characterized to study the influence of the heat treatment temperatures on the RF/SiO 2 aerogel. With the increase of the heat treatment temperature, its electromagnetic wave absorption performance had been significantly improved. When the heat treatment temperature reached 1500 ℃, the RF/SiO 2 aerogel possessed a minimum reflection loss of − 36.42 dB at 1.95 mm and an effective bandwidth of 2.94 GHz at 2.00 mm within the radar band of 8.00–12.00 GHz. In addition, this paper used CST software to optimize and design the periodic structure of metamaterial based on the RF/SiO 2 aerogel. The optimization design of the patch size and substrate thickness on the substrate surface provided a reference for the future application of this material in specific radar stealth fields. • The resorcinol/formaldehyde reinforced silica aerogel was synthesized. • The RF/SiO 2 aerogel possessed fine microwave absorption after 1500 ℃. • The periodic structure was designed to optimize the performantion. • The effect of the heat temperature especially on was further studied. • It provided a reference for the future application in specific radar stealth fields. [ABSTRACT FROM AUTHOR]

• This paper proposes a double-layer ring structure meta -material absorber which can achieve a wide absorption band between 9 GHz and 17.6 GHz at a thickness of 2.6 mm. • This paper presents a method of how to expand absorption band by structure analysis. Which can be applied to design new metamaterial absorber. Moreover, the configuration of it will be relatively simple. • This proposed absorber has significant application potential in the field of stealth technology. A double-layer meta -material absorber based on two "ring" structures is designed and fabricated in this paper. Each layer contains a different additional microstructure, which has the property of broadening the microwave absorption band. On the top layer we introduce a split on the ring structure, and on the bottom layer we bring in a short wire. According to the simulation results, the absorption band below −10 dB expands beyond 8.6 GHz compared to the original configuration. Moreover, there is a favorable coincidence between the experimental results and the simulations. The surface current and energy distribution of different meta -material structures are compared and analyzed to explain the absorption band expansion. It is shown that the varied distribution pattern of the surface current leads to multiple absorption peaks, which are connected to each other to form a broad absorption band. Moreover, the results illustrate that it is the splitting that causes the decoherence between the surface currents, which generates the frequency dispersion and hence the broadening of the absorption band. The distribution of the electric energy is analyzed and the results show it is the additional wire that forms a toroidal capacitor with the bottom ring to deepen the absorbing band. These results imply a different way of expanding the absorption band of metamaterial absorbers. [ABSTRACT FROM AUTHOR]

The design of lightweight and efficient electromagnetic wave absorbing materials (EWAMs) is of great significance in the fields of information security and the target stealth. Recently, hollow carbon-based confined structures have been widely concerned due to some unique characteristics of the electromagnetic wave absorption process. First, Hollow structures with resonant cavity characteristics facilitate electromagnetic wave scattering and endow structures with multimode resonance properties. Second, a hollow structure is beneficial to reduce its bulk density and complex permittivity, and its unique confined structure can be used as a "storehouse" for storing air to optimize the impedance matching characteristics of the EWAM. In this paper, the recent research progress on carbon-based hollow EWAMs has been profoundly reviewed, including the categories of pure carbon EWAMs and carbon-based composites, design strategies, synthetic methods, and the structure-function relationship of EWAMs. Finally, the challenges, and prospects for practical applications of hollow carbon-based structures are also discussed. We believe that this critical review is timely and not only highlights the recent advances and advantages of the carbon-based EWAMs, but also inspires new concepts for designing hollow-structure absorbers. [Display omitted] [ABSTRACT FROM AUTHOR]

• Small-angle grain boundaries (SAGB) form spontaneously by dislocation aggregation during solidification of Si at a high dislocation density. • The critical density for SAGB formation was found as ca. 107 cm-2. • SAGBs tend to coalesce with other SAGBs to leave the surviving SAGBs with higher misorientation. • SAGBs are able to spontaneously increase their misorientation by absorption of individual lattice dislocations during solidification. In situ observation of the solidification process of Si combined with ex situ characterization revealed that small-angle grain boundaries (SAGBs) increase misorientation through two paths. First, coalescence with other SAGBs leads to a boost in misorientation and SAGBs tend to coalesce during solidification. Second, the absorption of individual lattice dislocations also increases the misorientation of an SAGB. Three possible mechanisms behind dislocation absorption by SAGBs have been proposed and are discussed in this paper. Among these mechanisms, the incorporation of same-sign lattice dislocations is regarded as the prominent mechanism when misorientation increases during solidification. [ABSTRACT FROM AUTHOR]

This paper proposes a metamaterial absorption device (MAD) based on Block Dirac semimetal (BDS), which exhibits five band perfect absorption in 5.96 THz, 7.86 THz, 9.84 THz, 11.91 THz, 12.22 THz, the absorption rates of M 1 -M 5 are 0.987, 0.998, 0.997, 0.996, 0.999 and Q-factors are 54.36, 131.06, 61.61, 99.75, 102.58, respectively. The MAD has a three-layer structure consisting of substrate gold, silica, and top layer BDS, where BDS is designed as a cylindrical and circular microstructure. And polarization insensitivity due to the symmetry of the design. According to calculations, the MAD conforms to the impedance matching theory. In the analysis of the electric field diagram, it was revealed that the absorption of electromagnetic waves comes from LSPR and guided mode resonance effects. Based on the characteristics of BDS, this device can be tuned with changes in BDS Fermi energy, while also possessing certain physical tuning capabilities. When exploring the refractive index sensitivity of the device, we found that it has a high refractive index sensitivity. Among them, the sensitivity of M 1 -M 5 is 2000 GHz/RIU, 570 GHz/RIU, 3970 GHz/RIU, 3000 GHz/RIU, and 1000 GHz/RIU, respectively Overall, this device has strong application prospects in sensing fields such as biomedicine. [Display omitted] • Multi-band perfect absorption. • High Q-factor mode and refractive index sensitivity. • Physical and chemical tuning performance. • Electromagnetic coupling caused by LSPR and guided-mode resonance. [ABSTRACT FROM AUTHOR]

A multi-energy system that integrates a floating offshore wind turbine (FOWT) with wave energy converters (WEC) is an effective way to commercialize new offshore energy and the levelized cost of energy in the future. This paper proposes a FOWT-WEC hybrid system concept consisting of a semi-submersible FOWT with a Salter's duck (SD) WEC array. A coupling framework is established based on OpenFAST and ANSYS-AQWA. A preliminary feasibility study is conducted on the power absorption and motion response of the hybrid system to evaluate the interaction between the SD WEC array and the FOWT. Systematic studies demonstrate that the SD WEC array significantly reduces the motion response of the hybrid system in terms of pitch and heave. An increase in the equilibrium position of the platform in the surge direction does not have a large effect on the stability of the system. The WEC array improves the stability of wind power output and can be used as an effective supplement to power generation. The effect of wave direction shows that the SD WEC has a high sensitivity to the angle of incident waves, and the diffraction and radiation from the platform have a large impact on the power absorption of the SD WEC array. • An OpenFAST-AQWA coupling framework is proposed to achieve aero-hydro simulation. • A novel hybrid system consisting of FOWT and Salter's duck WECs is proposed. • The WEC array reduces the pitch motion response of the FOWT. • The effect of platform motion and wave direction on array power absorption is studied. [ABSTRACT FROM AUTHOR]

Ultra-black materials have been widely used in various fields. However, current ultra-black materials have weak surfaces owing to their light-absorbing structures. Even slight wiping can severely affect their performance. In this paper, we present a new approach for obtaining a regular light-absorbing structure based on an anodic aluminum oxide (AAO) template. The experimental results indicated that the film surface exhibited a typical forest structure via the film-forming, curing, and template-removal processes. Carbon nanotubes (CNTs), as light-absorbing media, can absorb light in conjunction with the special forest structure. The average light absorption of the V-type film in the wavelength range of 400–2000 nm was as high as 99.47 %. In addition, the high light absorption was maintained at multiple incident angles (5–70°), indicating its excellent omnidirectional absorption capability. Because the light-absorbing structure is produced by the cured resin material and partially exposed CNTs, the structure is sufficiently strong to prevent failure caused by wiping. This innovative method overcomes the drawbacks of the weak surfaces of conventional light-absorbing films and combines excellent light absorption capability with good resistance to wiping. • The proposed new preparation method based on AAO template obtains typical forest structures. • Film with ultra-black performance realizes good resistance to wiping. • Average absorption of film reaches to 99.49 % in the wavelength of 400–2000 nm. • Outstanding omnidirectional absorption performance [ABSTRACT FROM AUTHOR]

In recent years, there has been a considerable increase in interest in carbon nanotubes (CNTs) due to their numerous uses in energy and environmental remediations. This review paper provides an in-depth study of current developments in CNT concerning various technologies, focusing on their mechanisms and performance improvement towards energy and environmental applications. CNTs have extraordinary promise in the energy sector as catalysts for fuel cells, components for energy storage systems, and effective conductors in battery and supercapacitors. CNTs have demonstrated exceptional adsorption capabilities in environmental remediation for various pollutants, including heavy metals, organic contaminants, and greenhouse gases. This study explores the fundamental mechanisms enabling various applications, illuminating the physicochemical and molecular interactions involved. In addition, a rapid and straightforward synthesis approach for developing a hybrid material integrating carbon nanotubes in a single step is discussed. This unique structure and the synergistic interplay between the two nanomaterials enhance their physicochemical properties and showcase remarkable electrocatalytic capabilities. This study represents a significant contribution toward understanding the electrocatalytic potential of carbon nanotubes and their hybrid composites, with implications for diverse environmental and energy harvesting. As CNTs continue to develop as a potential class of materials, it is clear that they can help advance technology for environmental remediation and sustainable energy. This review provides insightful information for scientists and engineers to maximize the use of CNTs in addressing insistent issues with energy and environmental sustainability. [Display omitted] • Remarkable physiochemical properties that benefit various applications are reviewed. • The study highlights the importance of CNTs in energy storage and environmental remediation. • Diverse CNT functionalization for the targeted applications explores the surface impact on properties. • Explores research, scalability, economic cost, environment and future of CNTs. [ABSTRACT FROM AUTHOR]

Absorption carbon capture is currently the most commercialized technology and deemed as the vital solution to balance continued use of fossil fuels and carbon emission reduction. Nevertheless, its high energy cost remains the major concern for wide-scale application. Consequently, it is of great significance to address this issue by analyzing the underlying energy conversion mechanism, answering the pivotal question "What characteristics lead to a superior absorbent?", and developing more efficient absorbent. In this paper, an irreversible decoupling model of absorption carbon capture system, consisting of a heat engine and a chemical pump, is innovatively established. Accordingly, key performance indicators are analytically derived and the optimal operation strategies of the system are explicitly determined. Notably, the matching of two subsystems leads to a novel insight into the heat and mass transfer interaction of absorbent, according to which the simulated results and the question concerning the best absorbent are thermodynamically interpreted and addressed, respectively. Additionally, the comparisons between the calculated optimal energy conversion efficiencies with experimental and simulated results are presented and discussed. Our findings may indicate the efficient pathway for developing advanced absorbent and provide instructing information for the design and operation of practical carbon capture systems. [Display omitted] • An irreversible decoupling model of absorption carbon capture system is established. • Optimal energy conversion efficiency and parameters are analytically derived. • A new insight into the heat and mass transfer interaction of absorbent is provided. • Theoretical answer to the pivotal question concerning optimum absorbent is obtained. • Optimal absorbent selection criteria and operation regions are determined. [ABSTRACT FROM AUTHOR]

In environments with high humidity or water exposure, the performance of polyurethane materials could be adversely affected by water and its penetration, which could compromise their long-term utility. The influence of water on polyurethane materials is affected by water transport and various factors. This article summarizes the factors affecting the water absorption of polyurethane, introduces research methods for water transport in polyurethane, analyzes the pathways of water transport, and reviews the influence of water on the mechanical properties of polyurethane and its composite materials. The ultimate goal of this paper is to furnish a comprehensive theoretical foundation and a valuable reference for the research and practical application of polyurethane materials in water environments. [Display omitted] • Polyurethane water absorption is influenced by multiple factors. • Summarized the research methods for water transport in polyurethane. • Analyzed the pathways of water transport in polyurethane. • Water significantly affects the mechanical properties of polyurethane. [ABSTRACT FROM AUTHOR]

In this paper, we consider the Schwarzschild-Tangherlini black hole to investigate the process of scalar wave scattering by the black hole in a spacetime of (d + 1) dimensions and also with the generalized uncertainty principle (GUP). In this scenario, we analytically determine the phase shift and explore the effect of extra dimensions by calculating the differential scattering and absorption cross-section by applying the partial wave method at low and high-frequency limits. We show at high dimensions that the absorption is not zero as the mass parameter approaches zero. [ABSTRACT FROM AUTHOR]