Effective Absorption Research Articles

Exploration of microwave absorptivity and catalysis of CMF@Co-MoS2 for microwave-initiated depolymerization of lignin

Obtaining key platform chemicals from lignin is a sustainable refining concept of the non-petroleum route. Rapid pyrolysis is a potential refining technology, and microwave-assisted catalytic depolymerization with low energy consumption is preferred. Herein, we reported the strategy of microwave-initiated depolymerization using a self-designed dynamic vapor flow reaction system with a facilely prepared CMF@Co-MoS2-0.18 catalyst, achieving efficient conversion of lignin (Dealkalize) to monophenol. Under constant microwave irradiation (2.45 GHz), the CMF@Co-MoS2-0.18 catalyst had excellent dielectric properties (Dielectric loss factor: 0.56) and microwave heating properties (∼140 s rise to ∼ 600℃). Therefore, microwave-initiated depolymerization of lignin showed that the CMF@Co-MoS2-0.18 catalyst can improve the monophenol content (54.72 %) and phenol selectivity (35.84 %) under the synergistic effect of microwave absorptivity and catalysis. The reaction of the lignin model and kinetics analysis show that the CMF@Co-MoS2-0.18 catalyst increases the yield of monophenol by reducing depolymerization activation energy and selectively breaking the β-O-4 bond. The finite element analysis pointed out that under microwave irradiation, CMF@Co-MoS2-0.18 continuously conducted heat to lignin and the lignin vapor would have sufficient energy to collide with the catalyst active site at a high frequency, which led to an increase in the pre-exponential factor and initiated catalytic depolymerization lignin. In summary, we provide a potential pathway for the rapid conversion of lignin into key platform chemicals.

Polymetallic red mud direct materialization strategy towards zero waste emission: Electromagnetic wave absorption conversion and sodium solidification

Red mud is an industrial hazardous alkaline solid waste, whereas it is rich in polymetallic components showing a high comprehensive utilization value. Direct materialization of red mud towards zero waste emission is a more reasonable and environmentally friendly strategy. In this work, a novel materialization approach of red mud via converting the polymetallic constituents into functional ferrite material by phase reconstruction with MnO2 was proposed. The mineral phase reconstruction, microstructure evolution, reaction interface observation, electromagnetic property, and the materialization conversion mechanism were investigated. It was found that the complicated phases in red mud were transferred to simple forms including the magnetic ferrites (Ca/Na/Al/Ti-bearing Mn ferrite) and weakly magnetic silicates ((Na,Al,Ca)2SiO3) after phase reconstruction. The reconstructed red mud after sintering at 1200 ℃ for 120min in air atmosphere had satisfactory electromagnetic property. Magnetism study demonstrated the soft magnetic property with maximum saturation magnetization of 34.22emu/g and coercivity of only 7.0Oe. Compared with the original red mud, effective electromagnetic wave absorption with reflection loss (RL) values of the reconstructed red mud below -20 dB were satisfied across a wider frequency bandwidth of 5-18GHz, and the minimum RL value was lower as -32.4dB with a thinner veneer thickness of 15mm, highlighting its excellent electromagnetic wave absorption performance. Moreover, Na solidification behaviors indicated that Na was solidified in the sintered product, which can reduce the possible environmental hazards of red mud alkalinity. The novel materialization treatment with zero waste emission exhibits a favorable application prospect with a large red mud batching ratio about 50wt%.

1,3-Naphthoxazine derivatives: Synthesis, in silico pharmacokinetic studies, antioxidant and photoprotective properties

Investigation into the interactions between photoprotective agents and skin can offer a precise understanding of their biological behaviors in vitro and in vivo, providing crucial insights for generating new substances. For this purpose, we designed and synthesized a series of naphthoxazine derivatives and examined their photoprotective properties. 1,3-naphthoxazine derivatives were synthesized through the multi-component reaction of 2-naphthol, arylamines and aromatic aldehydes in the presence of copper(II) trifluoromethanesulfonate (Cu(OTf)2) and (±)-Camphor-10-sulfonic acid ((±)-CSA) catalyst system under sonication. The potential of these synthesized 1,3-naphthoxazine derivatives as antioxidants and viable organic structural-based sunscreen ingredients has been investigated. Sun protection factor (SPF) assay results showed that especially compounds 4i, 4c, 4k, 4d, 4r, and 4h had remarkably high activity (23.65, 23.57, 23.04, 21.94, 20.80, and 20.26, respectively at 900 µg/mL concentration). Additionally, antioxidant activity of the synthesized compounds was evaluated and compounds 4h, 4e, 4b, and 4j exhibited the highest activities in DPPH scavenging activity assay (86.46 %, 82.83 %, 80.78 %, and 80.65 % respectively at 400 µg/mL concentration). The synthesized compounds exhibit promising characteristics for effective UV radiation absorption, suggesting their suitability for inclusion in sunscreen formulations. Cytotoxic activity of compound 4k against normal human fibroblast cell line (MRC-5) was determined by CVDK-8 method. The results revealed that the compound provided remarkable viability (87.55 %) of MRC-5 cells at concentration of 100 µM. The study explores their efficacy in providing broad-spectrum protection against UVA and UVB rays, degradation and photostability, ADMET profile, and other pharmacokinetic properties.

Lightweight dielectric-magnetic synergistic necklace-shaped Co@NCP/carbon nanofiber composites for enhanced electromagnetic wave absorption

In order to solve the problem of impedance mismatch of carbon fiber absorbing materials, it is crucial to create a carbon-based absorbing material with a special structure, synergistic magnetic and dielectric properties. In this paper, necklace-shaped Co@N-doped carbon polyhedron /carbon nanofiber (Co@NCP/CNF) composites with synergistic magnetic and dielectric properties are successfully fabricated by electrospinning. Compared with Co@NCP and CNF, the optimal minimum reflection loss of Co@NCP/CNF composite is -66.14 dB at 2.89 mm and the maximum effective absorption bandwidth is 6.24 GHz (11.76-18.00 GHz) at 2.25 mm at a low filler load of 10 wt.%. The necklace-like structure, the coupling effect of dielectric and magnetic materials and the heterogeneous interface form multiple polarizations, conductive losses and multiple loss mechanisms to optimize impedance matching and attenuation performance, which is conducive to excellent absorption performance. More importantly, the radar cross section (RCS) reduction is as high as 24.02 dB·m2, which has proven to have a good absorption effect in actual application environments. This work combines the advantages of Co@NCP and CNF very well, which provides guidance for designing EM waves nanocomposite fiber absorbers with lightweight and strong absorbing properties.

Construction of 2D/2D heterostructure with porous few layer g-C3N4 and NiCo2O4 nanosheets towards electromagnetic wave absorption

Developing high-performance materials with ultra-high reflection loss (RL ≤ -65 dB) for electromagnetic wave (EMW) absorption is pivotal to address electromagnetic pollution, but it is still challenging. Herein, a two-dimensional (2D)/2D PFL g-C3N4/NiCo2O4 heterostructure with porous few-layer g-C3N4 (PFL g-C3N4) and ultrathin NiCo2O4 nanosheets has been prepared by self-assembly, hydrothermal reaction, and calcination strategies. The 2D/2D heterostructure exhibits extraordinary EMW absorption property, achieving a reflection loss (RL) value of -68.59 dB and an effective absorption bandwidth (EAB) of 1.92 GHz at a matching thickness of 2.5 mm. As expected, the porous few layer g-C3N4 nanosheets provide rich interface which increases multiple reflection paths and enhances the conduction loss. The cooperative effects of magnetic loss, dielectric loss, and impedance matching contribute to the exceptional EMW absorption property of PFL g-C3N4/NiCo2O4 (2D/2D) heterostructure. The potential of PFL g-C3N4/NiCo2O4 in actual radar stealth is verified through radar scattering cross-section (RCS) simulation. This work paves the way for utilizing 2D/2D heterostructure as an ultra-efficient EMW absorbers.

A dual-band broadband absorber using frequency selective surface for satellite antenna.

A dual-band broadband absorber based on frequency selective surface (FSS) is proposed. This double-layer absorber consists of two layers of FSS structure; each layer has a unique construction and plays its wave-absorbing function in different frequency bands. In the low-frequency band, layer I is a transmission channel, and layer II effectively absorbs electromagnetic waves. Furthermore, layer I exhibits significant absorption characteristics in the high-frequency band, whereas layer II provides effective reflection. The combination of the two layers results in a remarkably effective absorption. Its reflectivity below - 10dB covers a bandwidth of 5.5-14.8GHz and 22.9-33.1GHz, and its fractional bandwidth is 128%. The structure prevents external electromagnetic interference from affecting the antenna's performance, ensuring communication quality in critical frequency bands while reducing unwanted absorption in unwanted frequency bands. It is worth mentioning that the structure still has good stability under 45° oblique incidence. The physical mechanism is analyzed in detail by using an equivalent circuit model (ECM). The measurement results are in good agreement with those of simulation and ECM.

Variable structures in the stellar wind of the HMXB Vela X-1

Strong stellar winds are an important feature in wind-accreting high-mass X-ray binary (HMXB) systems. Exploring their structure provides valuable insights into stellar evolution and their influence on surrounding environments. However, the long-term evolution and temporal variability of these wind structures are not fully understood. This work probes the archetypal wind-accreting HMXB Vela X-1 using the Monitor of All-sky X-ray Image (MAXI) instrument to study the orbit-to-orbit absorption variability in the $2–10$ keV energy band across more than 14 years of observations. Additionally, the relationship between hardness ratio trends in different binary orbits and the spin state of the neutron star is investigated. We calculated X-ray hardness ratios to track absorption variability, comparing flux changes across various energy bands, as the effect of absorption on the flux is energy-dependent. We assessed variability by comparing the hardness ratio trends in our sample of binary orbits to the long-term averaged hardness ratio evolution derived from all available MAXI data. Consistent with prior research, the long-term averaged hardness ratio evolution shows a stable pattern. However, the examination of individual binary orbits reveals a different hardness ratio evolution between consecutive orbits with no evident periodicity within the observed time span. We find that fewer than half of the inspected binary orbits align with the long-term averaged hardness evolution. Moreover, neutron star spin-up episodes exhibit more harder-than-average hardness trends compared to spin-down episodes, although their distributions overlap considerably. The long-term averaged hardness ratio dispersion and evolution are consistent with absorption column densities reported in literature from short observations, indicating that a heterogeneous wind structure -- from accretion wakes to individual wind clumps -- likely drives these variations. The variability observed from orbit to orbit suggests that pointed X-ray observations provide limited insights into the overall behaviour of the wind structure. Furthermore, the link between the spin state of the neutron star and the variability in orbit-to-orbit hardness trends highlights the impact of accretion processes on absorption. This connection suggests varying accretion states influenced by fluctuations in stellar wind density.

Designing Quasi-Intrinsic Photosensitizers with Dual Function of Fluorescence Imaging and Photodynamic Therapy.

Photosensitizers (PSs) with effective two-photon absorption in the therapeutic window are the key to two-photon photodynamic therapy. However, the traditional exogenous PSs usually lead to rejection in the body. Besides, the precise visualization of treatments proposes new demands and challenges for the design of PSs. Accordingly, in this work, a series of quasi-intrinsic PSs are obtained based on the artificial base 2-amino-8-(1'-β-d-2'-deoxyribofuranosyl)-imidazo[1,2-α]-1,3,5-triazin-4(8H)-one (P). The calculations show that the structural modification could enhance the two-photon absorption and fluorescence emission, which is beneficial for tumor localization. Furthermore, the reduced singlet-triplet energy gaps and enhanced spin-orbit coupling contribute to the rapid intersystem crossing process, which results in a triplet state with high quantum yields. To ensure the phototherapeutic performance of the newly designed PSs, we also examined the vertical electron affinity and vertical ionization potential for generation of superoxide anions, as well as the T1 energy required to produce singlet oxygen.

Plasma-Driven Conversion of 2D Graphene into 3D Pouch for Improved Electromagnetic Absorption Performance.

Graphene-based materials are ideal for electromagnetic wave-absorbing materials (EAMs) due to their strong electrical and dielectric losses with reduced thickness and weight. To enhance the electromagnetic wave absorption performance of these materials, additional components are often incorporated. However, this approach not only increases the complexity of the synthesis process but also complicates and destabilizes the control of the material properties. In this study, we successfully employed a one-step method to reduce graphene oxide and transform 2D graphene into a 3D pocket-like structure through plasma treatment. This unique 3D structure is induced by the formation of uneven defects on the surface due to plasma treatment. The distinctive pouch-like structure of the reduced graphene oxide achieved remarkable electromagnetic wave absorption properties. Specifically, the material demonstrated a minimum reflection loss of -38.65 dB at 7.14 GHz, with an effective absorption bandwidth of 5.13 GHz and a thickness of just 1.9 mm. These results highlight the potential of plasma processing as a rapid, efficient, and environmentally friendly approach for the continuous production of advanced EAMs, paving the way for greener manufacturing practices in the industry.

Hetero‐Dimensional Micro‐Nano Architectures Toward Electromagnetic Devices and Hybrid Energy Transport

AbstractHuman spaceflight, lunar exploration projects, and interstellar travel are the grand visions of human exploration of the universe. However, the energy sustainability of these projects is a concern. Electromagnetic functional materials and devices are expected to fulfill their potential in electronic communication and energy utilization. Herein, hetero‐dimensional micro‐nano architectures composed of Cu3Se2 microspheres and reduced graphene oxide (rGO) sheets are fabricated for the first time by the sacrificial template method, anion substitution engineering, electrostatic adsorption, and reduction‐oxidation reaction. Based on the excellent electromagnetic response of the composites, they exhibit strong and ultra‐wide microwave absorption ability with the effective absorption bandwidth (EAB) reaching 8.24 GHz at a thickness of 2.2 mm. In addition, an electromagnetic metamaterial with an EAB to ≈13.5 GHz is proposed, exhibiting significant properties. More significantly, the composites can be used to construct a range of electromagnetic devices: a spiral antenna with adjustable return loss and gain, with a maximum gain of up to 2.5 dBi; a microstrip power divider that can efficiently split the input signal into four equal parts and output it; a hybridized energy transport device can convert and store electromagnetic energy. This work provides new inspiration for electromagnetic protection, electronic communication, and energy development.

Study on the Sound Absorption Characteristics and Noise Reduction Mechanism of Coconut-Shell-Activated Carbon Particles and Coconut Fiber Composite Biomass Sound-Absorption Materials

Abstract Sound absorbing materials are widely used in the field of automotive industry. Biomass materials are abundant in nature, and some biomass has natural sound absorption and noise reduction properties. Biomass sound absorption material is green and pollution-free, and has obvious noise reduction effect on middle and high frequency noise, large specific surface area, light weight, and strong sound absorption effect. In order to analyze the sound absorption and physical properties of biomass sound absorbing materials, the noise reduction performance of the different structure of biomass sound absorbing materials were analyzed. In this paper, the biomass sound absorbing materials coconut fiber and coconut shell activated carbon particles were used to make samples. Coconut shell activated carbon sound absorption material (CSAC) was made. The cylindrical holes was made and filled with coconut fiber materials to form composite sound absorbing materials (CSAC-F). The acoustic performance of impedance tube was tested based on the acoustic absorption coefficient, and the physical performance was studied by means of Scanning Electron Microscope (SEM), Brunauer, Emmett and Teller (BET), X-ray diffraction (XRD), Fourier Transform Infrared Spectrometer (FTIR), Thermogravimetric (TGA) and other detection methods. In contrast, the sound absorption effect of CSAC-F was better in the middle and low frequency range. The microstructure of the material was analyzed and the mechanism of noise reduction was studied. This research will provide a new way for the research and development of sound absorbing materials in the automotive industry, and biomass sound absorbing materials have potential applications in the noise absorption and vibration control of automotive interior.

The effect of filler distribution on electromagnetic properties of nanocarbon/magnetic particles/polymer composites

The type of multi-component fillers and their spatial distribution in conductive polymer-based composites greatly influenced their electrical properties, electromagnetic shielding efficiency (SE), and absorption capability, which require a deep understanding of how these properties improve with changes in the phase composition, content, and distribution of these fillers in the composite. In this study, three-phase polymer composite materials (CMs) with random (epoxy-based) and segregated (polyethylene-based) distribution of nanocarbon (graphite nanoplatelets GNP and carbon nanotubes CNTs) and magnetic (Fe and Co3O4) fillers have been developed. It was found that permittivity εr′ in the frequency range (40–60 GHz) increases sufficiently with the nanocarbon content and their values are slightly higher for random GNP-filled CMs (εr′=10–15 for 3–5 wt. % GNP) compared to CNT-filled CMs and much higher compared to segregated CMs (εr′=4–7 for 3–5 wt. % of nanocarbon). Dielectric loss tangent tanδ is increased with the nanocarbon content (especially for Fe-filled CMs) and sufficiently higher in segregated CMs compared to similar random composites. These enhanced tanδ values correlate with higher electromagnetic shielding efficiency due to absorption of segregated nanocarbon/magnetic/polyethylene CMs, for example, SEAd ≈ 18–23 dB/mm for 5 wt. %GNP. The most preferable for microwave absorption are random and segregated CMs with 2–3 wt. % GNP/30 wt. % magnetic filler: RLmin = −(27–35) dB, effective absorption bandwidth (EAB) Δf10dB=11.5–12.5GHz at a sample thickness of 0.5–0.7 mm. In CNT-based segregated CMs, |RLmin| and EAB values are lower compared with GNP-based CMs. The ability to manipulate these characteristics is important for obtaining good shielding and absorptive properties in the microwave range of electromagnetic radiation.

Evaluating the mixed convection flow of Casson fluid from the semi-infinite vertical plate with radiation absorption effect

This study examines a steady laminar Casson fluid flow induced by a semi-infinite vertical plate under the impact of the Darcy-Forchheimer relation and thermal radiation. The features of mixed convection, cross-diffusion, radiation absorption, heat generation, chemical reactions and viscous dissipation are also considered to explain the transport phenomenon. The resultant system of equations, concerned with the problem under consideration, is transformed into a group of non-linear ordinary differential equations (ODEs) by means of similarity variables. The bvp4c method, an instrument popular for its numerical accomplishments, is utilized to solve this problem. The effect of flow parameters on heat transfer, concentration and velocity is evaluated via diagrams. To validate our code, we have compared the present outcomes to the prevenient literature, and stable consent has been detected. Moreover, the friction coefficient Cfx, Nusselt number Nux, and Sherwood number Shx are also computed to assess velocity gradient, efficiency of heat transfer and mass transfer process, respec-tively.

Effects of Absorption on the Tribological Properties of Carbon Fiber Reinforced Polyamide-6 Composites Manufactured by Fused Deposition Modeling

Abstract The present work studied the water absorption behavior of polymeric composite materials fabricated using 3D printing technology, as well as its effect on their tribological properties. Polyamide-6 was selected as the base matrix material. Short and continuous carbon fibers are used as the reinforced material. The results showed that the moisture absorption would impair the mechanical properties of polymer matrix and interface bonding between the fiber and the matrix. As a result, the tensile strength of the fiber reinforced polymer composites (FRPCs) decreases with water absorption. Nevertheless, the effects of moisture absorption on the wear properties of FRPCs are more complicated, which are depending on the fiber length and sliding conditions. With the short fiber reinforcements, moisture absorption deteriorated the wear resistance under all the testing conditions. With the increase of moisture level, more severe fiber damage/removal was observed, associated with the higher wear loss. With a relative high volume fracture of continuous carbon fiber (∼35 vol%), however, the wear resistance of the FRPC increased with moisture level, especially under a relatively low load. Based on microscopic observations, it was proposed that water inside FRPC specimens is able to provide the lubricating and cleaning effects, which contribute to a lower friction and smooth worn surfaces. The work provides new insights into designing and selecting printed polymer materials, subjected to different loading conditions.

Fe-loaded two-dimensional nitrogen-doped carbon for electromagnetic wave absorption

Abstract Electromagnetic wave absorbing materials are particularly important in modern electronics, especially in the fields of stealth and communications. Carbon-based materials show great promise in the production and application of efficient wave-absorbing materials due to their rich structure, ultra-light weight, good corrosion resistance, and low cost. Among them, nitrogen-doped carbon-based two-dimensional materials have a stronger depletion effect on electromagnetic waves due to their higher specific surface area and abundant polarization states. In this article, nitrogen-doped carbon 2D flakes (NC) were successfully synthesized by a hydrothermal method. Furthermore, Fe single atoms were successfully loaded onto their surfaces, creating Fe@NC. The wave-absorbing properties of Fe@NC samples were significantly enhanced, with the minimum reflection loss (RLmin) reaching -69.22 dB at 11.48 GHz and the effective absorption bandwidth (EAB) extending to 5.79 GHz. The enhancement of electromagnetic wave absorption is attributed to the synergistic effects of magnetic loss, relaxation processes, dipole polarization, and electrical conduction loss. The successful preparation of Fe@NC offers new possibilities for the development of atomically dispersed wave-absorbing materials.

Design and study of electromagnetic wave absorbing structure of multilayer GN/GF/EP composites

With the improvement of radar absorption performance requirements, the research of absorbing materials is an important research direction. In this paper, a graphene/glass fiber/epoxy (GN/GF/EP) structure design scheme is proposed. By measuring the electromagnetic parameters, the influence of different GN content on the absorber performance is analyzed, and the bilayer absorber material combination with the best absorber performance is determined. The double layer absorbing material was made of GN/GF/EP-1.0% (thickness 0.4 mm) and GN/GF/EP-2.5% (thickness 1.7 mm). The peak reflection loss of the double layer absorbing material is −41.55 dB, the center frequency is 10.93 GHz, and the effective absorption bandwidth is 2.86 GHz (9.34∼11.20 GHz).

SOLID LIPID NANOPARTICLES OF FENUGREEK SEED EXTRACT IN A DERMATOLOGICAL BASE FOR ALOPECIA: AN IN VIVO STUDY

Objective: The objective of the study was to investigate the potential of Solid Lipid Nanoparticles (SLN) of Fenugreek Seed Extract (FSE) in a dermatological base for its hair growth activity in alopecia Methods: The optimized SLN formulation of FSE was loaded into neutralized Carbopol 934 gel, and its hair growth efficacy was studied in Wistar rats in terms of hair density and length. Alopecia was induced in the rats by administering cyclophosphamide at a dose of 40 mg/kg for three days. The formulations were applied to the skin for twenty-one days following the induction of the disease. The hair growth in FSE-SLN gel-treated groups were compared with disease control and other treatment groups using qualitative and quantitative assessments. Results: FSE-SLN gel reduced the hair growth completion time comparable to that of the standard (p<0.01). The increase in hair length was significantly (p<0.01) greater in FSE SLN groups compared to groups treated with conventional gels, oils, and marketed formulations, demonstrating the superior hair growth efficacy of the developed FSE SLN. Conclusion: SLNs can enhance the penetration of extract into the skin (stratum corneum) compared to oil and gels, thereby increasing treatment efficiency, targeting the epidermis, and reducing systemic absorption and related side effects. Consequently, the developed nanoformulation can be a substitute for in vivo hair growth activity.

Improved visualisation of ACP-engineered osteoblastic spheroids: a comparative study of contrast-enhanced micro-CT and traditional imaging techniques

This study investigates osteoblastic cell spheroid cultivation methods, exploring flat-bottom, U-bottom, and rotary flask techniques with and without amorphous calcium phosphate (ACP) supplementation to replicate the 3D bone tissue microenvironment. ACP particles derived from eggshell waste exhibit enhanced osteogenic activity in 3D models. However, representative imaging of intricate 3D tissue-engineered constructs poses challenges in conventional imaging techniques due to notable scattering and absorption effects in light microscopy, and hence limited penetration depth. We investigated contrast-enhanced micro-CT as a methodological approach for comprehensive morphological 3D-analysis of thein-vitromodel and compared the technique with confocal laser scanning microscopy, scanning electron microscopy and classical histology. Phosphotungstic acid and iodine-based contrast agents were employed for micro-CT imaging in laboratory and synchrotron micro-CT imaging. Results revealed spheroid shape variations and structural integrity influenced by cultivation methods and ACP particles. The study underscores the advantage of 3D spheroid models over traditional 2D cultures in mimicking bone tissue architecture and cellular interactions, emphasising the growing demand for novel imaging techniques to visualise 3D tissue-engineered models. Contrast-enhanced micro-CT emerges as a promising non-invasive imaging method for tissue-engineered constructs containing ACP particles, offering insights into sample morphology, enabling virtual histology before further analysis.

Impacts of Buoyancy and Joule Heating on Unsteady MHD Fluid Flow Along a Semi‐Infinite Vertical Porous Plate With Dufour, Chemical Reaction, and Radiation Effect

ABSTRACTAn analytical solution for unsteady, incompressible, laminar MHD fluid flow involving mass and heat transfer along a semi‐infinite vertical moving flat plate in a porous medium have been studied in this paper. Effects of heat radiation and absorption, Joule heating, Dufour, thermal and solutal buoyancy, and first order chemical reaction of are discussed under suitable physical conditions. It is postulated that the plate will migrate in the fluid's motion's direction due to the presence of a uniform magnetic field normal to the porous surface. The regular perturbation technique is used to solve the dimensionless governing equations. The mathematical derivations for fluid velocity, temperature, and concentration are evaluated; apart from that, skin friction, rate of mass and heat transfer at the plate are also expressed. The present outcomes are compared with previously obtained results and are found to be in excellent agreement. It is observed that the fluid velocity and temperature enhanced with thermal and solutal buoyancy forces as well as the Dufour effect. Also, with an increase in chemical reaction parameter, there is a decrease in fluid velocity, temperature, and concentration. Skin friction and Nusselt number increase with higher heat absorption parameter values. Schmidt number and chemical reaction parameter both lead to a rise in Sherwood number. Applications for these models have been observed in a number of industrial and technical methods.

Investigation of amyl acetate sorption impact on high‐density polyethylene bottle properties

AbstractThermoplastics based on polyolefins, including polypropylene, high‐density polyethylene and low‐density polyethylene, are extensively utilized across various packaging sectors. The selection of these materials for specific applications is influenced by multiple factors, such as the polymer's absorption characteristics and the impact on its mechanical properties when in contact with the packaged product. This study presents an experimental methodology designed to simulate the effects of absorption on the macroscopic and microscopic properties of high‐density polyethylene bottles in contact with amyl acetate. Macroscopic degradation was evaluated by modeling mechanical damage using unified theory and the energy method. Analytical techniques such as gravimetric analysis, scanning electron microscopy and Fourier transform infrared spectrometry were employed. The findings of this research provide valuable insights for suppliers and industries to experimentally determine the usability and safety intervals of plastic packaging through comprehensive macroscopic and microscopic analyses within relatively short timescales. © 2024 Society of Chemical Industry.