Electron Energy Research Articles

Influence of tin additions on the corrosion passivation of TiZrTa alloy in sodium chloride solutions

Abstract In this study, the fabrication of Ti-12%Zr-4%Ta-2%Sn alloy, Ti-12%Zr-4%Ta-4%Sn alloy, and Ti-12%Zr-4%Ta-6%Sn alloy using powder metallurgy fabrication technique has been carried out. The influence of Sn addition on the corrosion of these alloys after 30 min and 3 days in 3.5% NaCl solution using various techniques has been reported. The Nyquist spectra revealed that boosting Sn content from 2 to 4% and further to 6% increases the corrosion resistance of the alloy through increasing the diameter of the obtained semicircle. Bode spectra also elucidated that the increased percentage of Sn increases the values of the impedance of the interface |Z| and the maximum degree of the phase angle (Φ). It was indicated from the cyclic polarization curves that the increased Sn content increases the passivation of the alloy through decreasing its rate of corrosion and increasing its corrosion resistance. The measured current over time at −0.10 V showed that the alloy with low Sn content, 2%, records the highest currents, which pronouncedly decreases when Sn content increases to 4% and further to 6%. Prolonging the time of exposure from 30 min to 3 days greatly enhances the passivation of the TiZrTaSn alloys due to the formation of mixed oxides of TiO2, ZrO2, TaO2, and SnO2. The results of these electrochemical measurements were confirmed by the surface investigations carried out by scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS). The results collectively proved that the uniform corrosion remarkably decreases with the increase in the Sn% and that the pitting corrosion is not likely to take place.

Durable lightweight cementitious composites incorporating rice husk: Accelerated aging studies with acidic and basic solutions

This study investigates the compatibility between cellular concrete (foamed concrete) and natural rice husk to develop high-performance and sustainable sealing materials. Through a bibliographical review we identified challenges in incorporating vegetable fibers into cementitious matrices due to problems related to durability. Prismatic samples of a Reference mixture (foamed concrete) and a Composite with foamed concrete and natural rice husk underwent chemical treatments with acidic and basic solutions to simulate long-term durability. Results show that even after complete organic matter degradation, the composite maintains adequate mechanical performance for sealing walls. Microstructural analyses, including scanning electron microscopy, x-ray diffraction, x-ray fluorescence, and energy dispersive spectroscopy, revealed that silica in the rice husk significantly contributes to axial compression strength by forming C–S–H. The degradation of natural polymers results in the formation of calcium carbonate and calcium sulfate dihydrate, mitigating strength loss. This study proves that the composites with natural rice husk and foamed concrete are a viable and durable solution, provided it does not include metallic materials susceptible to corrosion in composition.

Self-consistent calculation of the optical emission spectrum of an argon capacitively coupled plasma based on the coupling of particle simulation with a collisional-radiative model

We report the development of a computational framework for the calculation of the optical emission spectrum of a low-pressure argon capacitively coupled plasma (CCP), which is based on the coupling of a particle-in-cell/Monte Carlo collision simulation code with a diffusion-reaction-radiation code for Ar I excited levels. In this framework, the particle simulation provides the rates of the direct and stepwise electron-impact excitation and electron-impact de-excitation for 30 excited levels, as well as the rates of electron-impact direct and stepwise ionization. These rates are used in the solutions of the diffusion equations of the excited species in the second code, along with the radiative rates for a high number of Ar-I transitions. The calculations also consider pooling ionization, quenching reactions, and radial diffusion losses. The electron energy distribution function and the population densities of the 30 excited atomic levels are computed self-consistently. The calculations then provide the emission intensities that reproduce reasonably well the experimentally measured optical emission spectrum of a symmetric CCP source operated at 13.56 MHz with 300 V peak-to-peak voltage, in the 2–100 Pa pressure range. The accuracy of the approach appears to be limited by the one-dimensional nature of the model, the treatment of the radiation trapping through the use of escape factors, and the effects of radiative cascades from higher excited levels not taken into account in the model.

Alternatywne podejście do usuwania/odzyskiwania wybranych metali z wody kopalnianej wypływającej z zalanej kopalni syderytu Nižná Slaná

The objective of this work was the application of innovative method for metals recovery from metalliferous mine water released from the flooded siderite ore deposit Nižná Slaná. Although the metals contained in mine drainage are considered environmental pollutants, they may also be recognised as valuable resources. Several techniques can be used to obtain them by precipitation. Conventional processes using alkaline reagents produce huge amounts of mixed sludge with appropriate storage and management requirement, void of possibility of individual metals subsequent processing. This study examined the feasibility of Fe and Mn selective retrieval from real mine water. After oxidation and partial precipitation of iron using hydrogen peroxide, precipitation by sodium hydroxide was applied to the residue iron removal from mine water. In the next step potassium permanganate was used to eliminate manganese by oxidative precipitation. ORP and pH values of processed mine water was recorded in the course of oxidation/precipitation processes. The morphology and elemental composition of obtained products were studied by scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDX). The recovery efficiencies of Fe and Mn from mine water reached 99.87 % and 99.25%, respectively. Target metals were removed with high selectivity to levels that comply with environmental requirements.

The effect of annealing on micro-hardness of molybdenum single crystals

Molybdenum (Mo) crystals exhibit excellent mechanical properties such as high yield strength, high elastic modulus, very high melting point, and excellent corrosion resistance, making them a suitable choice for various industrial applications. The mechanical behaviour of these crystals has been investigated through tension, compression, and indentation experiments. The indentation experiments on annealed Mo single-crystal thin film show an increase in hardness with increase in annealing temperature from 400 °C–650 °C. However, it is not clear whether this behaviour is specific to the Mo thin films or these are applicable to the bulk samples of single crystals also. In order to address these issues, the Vickers indentation experiments are performed on as-received and annealed samples of (100) -, (110) -, and (111) -oriented Mo single crystals. The results show that the low-temperature annealing leads to an increase in micro-hardness by 9% for (100) oriented crystals. The x-ray diffraction (XRD), electron backscatter diffraction (EBSD) and energy dispersive x-ray spectroscopy (EDS) studies have shown that there is a drop in the number of dislocation sources or dislocation density ( ρ ) with no high-angle grain boundary formation or any microstructural changes or any oxide formation. This necessitates to enhance the applied stress required for significant yielding (or yield strength) which results in an increase in the hardness. Based on experimental observations, a hardening mechanism governed by dislocation annihilation during annealing has been proposed in the present study.

Self-Modification of Defective TiO2 under Controlled H2/Ar Gas Environment and Dynamics of Photoinduced Surface Oxygen Vacancies.

In recent years, defective TiO2 has caught considerable research attention because of its potential to overcome the limits of low visible light absorption and fast charge recombination present in pristine TiO2 photocatalysts. Among the different synthesis conditions for defective TiO2, ambient pressure hydrogenation with the addition of Ar as inert gas for safety purposes has been established as an easy method to realize the process. Whether the Ar gas might still influence the resulting photocatalytic properties and defective surface layer remains an open question. Here, we reveal that the gas flow ratio between H2 and Ar has a crucial impact on the defective structure as well as the photocatalyic activity of TiO2. In particular, transmission electron microscopy (TEM) in combination with electron energy loss spectroscopy (EELS) revealed a larger width of the defective surface layer when using a H2/Ar (50 %-50 %) gas mixture over pure H2. A possible reason could be the increase in dynamic viscosity of the gas mixture when Ar is added. Additionally, photoinduced enhanced Raman spectroscopy (PIERS) is implemented as a complementary approach to investigate the dynamics of the defective structures under ambient conditions which cannot be effortlessly realized by vacuum techniques like TEM.

Formation processes of iron-based layered hydroxide in acid mine drainage and its implications for in-situ arsenate immobilization: Insights and mechanisms

The immobilization of arsenate in transformed minerals depends on their states in acid mine drainage (AMD). In this study, an iron-based layer hydroxide mineral was derived from the transformation of ferrihydrite under co-existing Mg2+ ions in AMD. The immobilization behavior of arsenate on the mineralized LDHm and pre-prepared LDHad was distinguished. 99 % immobilization efficiency was achieved from the mineralized LDHm, maintaining stability without subsequent releases, across initial arsenate concentrations ranging from 10 to 60 mg/L. LDHm outperformed the pre-prepared LDHad, which was synthesized from AMD for arsenate adsorption. Electron energy loss spectroscopy line profiles revealed predominant incorporation of arsenate in the LDHm structure, supported by higher bulk As signals within LDHm. Density functional theory calculations indicated primary arsenate incorporation into LDHm, forming stable bonds with lower energy activation barriers. Importantly, LDHm exhibited a superior electron rearrangement configuration, resulting in enhanced electron state activity and affinity for arsenate. In contrast, arsenate adsorption predominantly occurred on the pre-prepared LDHad, with notable As signals detected particularly at the edges. Adsorption energy evaluation indicated arsenate preference for bonding to Fe3+ sites on LDHad. These findings provide important insights into the role of stable LDH-like minerals for long-term arsenate immobilization in the natural AMD attenuation processes.

Green synthesis and characterization of AgNPs, liposomal loaded AgNPs and ZnPcS4 photosensitizer for enhanced photodynamic therapy effects in MCF-7 breast cancer cells

Breast cancer remains a formidable challenge in oncology despite significant advancements in treatment modalities. Conventional therapies such as surgery, chemotherapy, radiation therapy, and hormonal therapy have been the mainstay in managing breast cancer for decades. However, a subset of patient's experiences treatment failure, leading to disease recurrence and progression. Therefore, this study investigates the therapeutic potential of green-synthesized silver nanoparticles (AgNPs) using an African medicinal plant (Dicoma anomala methanol root extract) as a reducing agent for combating breast cancer. AgNPs were synthesized using the bottom-up approach and later modified with liposomes (Lip) loaded with photosensitizer (PS) zinc phthalocyanine tetrasulfonate (Lip@ZnPcS4) using thin film hydration method. The successful formation and Lip modification of AgNPs, alongside ZnPcS4, were confirmed through various analytical techniques including UV–Vis spectroscopy, Fourier-transform infrared spectroscopy (FT-IR), high-resolution transmission electron microscopy (HR-TEM), scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS). Following a 24 h treatment period, MCF-7 cells were assessed for viability using 3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyl tetrazolium bromide (MTT viability assay), cell death analysis using mitochondrial membrane potential (MMP) (ΔΨm), Annexin V-fluorescein isothiocyanate (FITC)-propidium iodide (PI) kit, and caspase- 3, 8 and 9 activities. The experiments were repeated four times (n = 4), and the results were analyzed using SPSS statistical software version 27, with a confidence interval set at 0.95. The synthesized nanoparticles and nanocomplex, including AgNPs, AgNPs-Lip, Lip@ZnPcS4, and AgNPs-Lip@ZnPcS4, exhibited notable cytotoxicity and therapeutic efficacy against MCF-7 breast cancer cells. Notably, the induction of apoptosis, governed by the upregulation of apoptotic proteins i.e., caspase 8 and 9 activities. In addition, caspase 3 was not expressed by MCF-7 cells in both control and experimental groups. Given the challenging prognosis associated with breast cancer, the findings underscore the promise of liposomal nanoformulations in cancer photodynamic therapy (PDT), thus warranting further exploration in clinical settings.

Formulation of tattoo paints from the assemblage of the Upper Paleolithic site of Ushki V (Kamchatka)

In recent times, the practice of body modification in sociocultural, psychological, and art studies contexts has gained a new impetus for research. This article presents the results of the analysis of pigments found on the sur-face of stone artifacts identified as tattooing tools from the assemblage of layer VII of the Upper Paleolithic site of Ushki V (13–12 ka calBP, Kamchatka Peninsula). The aim of this study is to reconstruct the formulation of paints discovered on the surface of stone tools from the collection of Ushki V, that could have been used for tattooing. The reconstruction was carried out by means of determining the composition and microstructure of the paints using scanning electron microscopy and energy dispersive X-ray spectroscopy (SEM-EDX). The conclusions about the structure of colouring substances and the composition of paints are based on the element mapping method, which allows determination of the relationships of chemical elements and establishing the chemical com-position of individual components of the microstructure. Seven samples of red and yellow paint from the surface of six tools (carvers) have been thoroughly analysed. As a result, it has been found that three recipes were used for the manufacture of the pigments. The first (red paint) was based on mixing crushed mineral pigment (hema-tite) with organic binder of animal or vegetable origin. The second (yellow paint) implied the use of limonite, or-ganic binder and a thickener (aluminosilicate material or crushed bone). The third recipe (dark orange paint) in-cluded the compound of limonite and organic binder without thickener. The comparison of the formulations with previously obtained data on the analysis of paints from Ushki V allows for the conclusion that there were continu-ous technological traditions determined by the desired color and purpose of the paint. It has been established that the formulations have analogies both among the assemblages of other Stone Age sites of Eurasia and in ethno-graphic materials. Theoretical and practical significance of this research lies within extending of focused studies of the culture of peoples of the North and initiating of comparative research into similar Late Paleolithic and Neolithic complexes in the territories adjacent to Kamchatka and in the New World.

Response of selenium pools to drought stress by regulating physio‑biochemical attributes and anatomical changes in Gentiana macrophylla

Selenium (Se), as a vital stress ameliorant, possesses a beneficial effect on mediating detrimental effects of environmental threats. However, the mechanisms of Se in mitigating the deleterious effects of drought are still poorly understood. Gentiana macrophylla Pall. is a well-known Chinese medicinal herb, and its root, as the main medicinal site, has significant therapeutic effects. The purpose of this experiment was to investigate the functions of Se on the seedling growth and physiobiochemical characteristics in G. macrophylla subjected to drought stress. The changes in microstructure and chloroplast ultrastructure of G. macrophylla leaves under drought exposure were characterized by scanning electron microscopy (SEM), scanning electron microscopes and energy dispersive X-Ray spectroscope (SEM-EDX), and transmission electron microscopy (TEM), respectively. Results revealed that drought stress induced a notable increase in oxidative toxicity in G. macrophylla, as evidenced by elevated levels of hydrogen peroxide (H2O2), lipid peroxidation (MDA), enhanced antioxidative response, decreased plant photosynthetic function, and inhibited plant growth. Chloroplasts integrity with damaged membranes and excess osmiophilic granule were observed in the drought-stressed plants. Se supplementation notably recovered the stomatal morphology, anatomical structure damage, and chloroplast ultrastructure of G. macrophylla leaves caused by drought exposure. Exogenous Se application markedly enhanced SPAD, photosynthetic stomatal exchange parameters, and photosystem II activity. Se supplementation significantly promoted the activities of superoxide dismutase (SOD), ascorbate peroxidase (APX), and catalase (CAT), while reducing levels of MDA, superoxide anion (O2–.) and H2O2, and improving membrane integrity. Furthermore, the ameliorative effects of Se were also suggested by increased contents of osmotic substances (soluble sugar and proline), boosted content of gentiopicroside and loganinic acid in roots, and alleviated the inhibition in plant growth and biomass. Fourier transform infrared (FTIR) analysis of Se-treated G. macrophylla roots under drought stress demonstrated that Se-stimulated metabolites including O-H, C-H, N-H, C-N, and CO functional groups, were involved in resisting drought stress. Correlation analysis indicated an obvious negative correlation between growth parameters and MDA, O2–. and H2O2 content, while a positive correlation with photosynthetic gas exchange parameters. Principal component analysis (PCA) results explained the total variance into two principal components contributing the maximum (93.50 %) among the drought exposure with or without Se due to the various experiment indexes. In conclusion, Se exerts beneficial properties on drought-induced detrimental effects in G. macrophylla by relieving oxidative stress, improving photosynthesis indexes, PSII activity, regulating anatomical changes, altering levels of gentiopicroside and loganinic acid, and promoting growth of drought-stressed G. macrophylla.

Interpretable Data‐Driven Descriptors for Establishing the Structure‐Activity Relationship of Metal‐Organic Frameworks Toward Oxygen Evolution Reaction

The development of readily accessible and interpretable descriptors is pivotal yet challenging in the rational design of metal‐organic framework (MOF) catalysts. This study presents a straightforward and physically interpretable activity descriptor for the oxygen evolution reaction (OER), derived from a dataset of bimetallic Ni‐based MOFs. Through an artificial‐intelligence (AI) data‐mining subgroup discovery (SGD) approach, a combination of the d‐band center and number of missing electrons in eg states of Ni, as well as the first ionization energy and number of electrons in eg states of the substituents, is revealed as a gene of a superior OER catalyst. The found descriptor, obtained from the AI analysis of a dataset of MOFs containing 3‐5d transition metals and 13 organic linkers, has been demonstrated to facilitate in‐depth understanding of structure–activity relationship at the molecular orbital level. The descriptor is validated experimentally for 11 Ni‐based MOFs. Combining SGD with physical insights and experimental verification, our work offers a highly efficient approach for screening MOF‐based OER catalysts, simultaneously providing comprehensive understanding of the catalytic mechanism.

Plasma properties in the vicinity of the last closed flux surface in hydrogen and helium fusion plasma discharges

The origin of the bi-Maxwellian electron energy distribution function (EEDF) observed in the scrape-off layer (SOL) of tokamak plasmas by means of Langmuir probes is still under discussion. It has been assumed that the ionization of hydrogen and deuterium neutrals by thermal electrons penetrating the SOL from the bulk plasma is the main reason for the appearance of a second Maxwellian. To validate this assumption, radial measurements of the electron temperatures and densities, or the plasma properties in helium plasmas in the GOLEM tokamak and the TJ-II stellarator were performed. The radial profiles of the low-temperature electron group densities follow the trend of the calculated radial profiles of the electron sources arising from the ionization of neutrals in both deuterium and helium plasmas in TJ-II. The difference in the radial location where the bi-Maxwellian EEDF appears can be explained by the difference in the rate coefficients for ionization of deuterium and helium. The results of probe measurements in GOLEM and the WEST tokamak divertor, at one radial location in the SOL, are compatible with the hypothesis concerning the ionization of neutral atoms and the type of the EEDF.

Unraveling the effects of non-parabolicity on electron energy levels in InP/InAs/InP heterostructures

In this research, electron energy levels were calculated analytically using Nelson’s formula, the shooting method, and Garrett’s formula for effective mass. These calculations were performed for a rectangular finite deep potential well, focusing on the InP/InAs/InP heterostructure, which is a narrow-bandgap semiconductor system. Our results demonstrate that the nonparabolicity of the dispersion has a more significant effect on higher energy levels compared to lower ones, with deviations of up to 15% for the third energy level. An equation estimating the number of observable energy levels in the potential well is suggested, revealing that considering nonparabolicity leads to a 20% increase in the number of levels compared to the parabolic dispersion case. The relationship between the widths of infinite and finite potential wells for equivalent energy levels follows a linear behaviour, with bonding coefficients ranging from 95,93% to 97,49% and a maximum difference of 1.5% between parabolic and non-parabolic cases. The transcendental equation for the energy levels is linearized, yielding a fourth-order equation that provides results within 98% accuracy compared to the original equation. These findings contribute to the understanding of the energy distribution in InP/InAs/InP heterostructures with a view to their application in optoelectronic devices such as lasers, light-emitting diodes

Multiwalled carbon nanotubes supported Fe nanostructured interfaces for electrochemical detection of uric acid

Uric acid (UA) levels in biological fluids are an important diagnostic and prognostic biomarker for various metabolic disorders. Therefore, a convenient, facile, one-step electroreduction method to develop Fe nanostructured (FeNS) interfaces for highly sensitive electrochemical detection of UA. The synthesis process was thoroughly investigated at various deposition potentials, pH of the electrochemical bath solutions, and growth durations to attain excellent electrochemical response towards UA detection. The morphology and elemental composition of the FeNS/MWCNT were analyzed using scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDXS) techniques. We observed uniform deposition of FeNSs with sizes ranging from 100 − 120 nm on tubular nanostructures. The multiwalled carbon nanotubes supported Fe nanostructured interfaces (FeNS/MWCNT) generated at a potential of –1.1 V demonstrated excellent electrochemical response towards UA with a wide linear detection range of 5 to 500 µM with a sensitivity of 6.5605 µA µM−1 cm−2 and low detection limit of 3.26 µM. The excellent electrochemical response was attributed to the synergistic effect of MWCNTs, which facilitated FeNSs growth, leading to increased active sites for electrocatalysis and sensitive detection of UA. The convenience of the synthesis process, tunable electrochemical response, and reliability of the detection process make FeNS interfaces a potential option for developing electrochemical UA sensors.

Quasi-monoenergetic electron beam from LWFA: analytical approach

Analytical dependence of the energy spread of electron beam on time and injection duration has been obtained with the 1D model of the quasi-linear laser wakefield electron acceleration, presented as phase portraits of electron energy relative to the plasma wave phase. The method for producing electron beams with variable energy and a lower energy spread compared to a standard bubble-like approach by transferring to a deaccelerating part with another phase trajectory (by reducing the plasma amplitude of a wave) has been developed. The analytically obtained results successfully describe key features of the previously obtained in Tsymbalov et al (2024 arXiv:2403.19828) experimental and numerical (PIC) data.

Role of the Binding Energy on Nondipole Effects in Single-Photon Ionization.

We experimentally study the influence of the binding energy on nondipole effects in K-shell single-photon ionization of atoms at high photon energies. We find that for each ionization event, as expected by momentum conservation, the photon momentum is transferred almost fully to the recoiling ion. The momentum distribution of the electrons becomes asymmetrically deformed along the photon propagation direction with a mean value of 8/(5c)(E_{γ}-I_{P}) confirming an almost 100year old prediction by Sommerfeld and Schur [Ann. Phys. (N.Y.) 396, 409 (1930)10.1002/andp.19303960402]. The emission direction of the photoions results from competition between the forward-directed photon momentum and the backward-directed recoil imparted by the photoelectron. Which of the two counteracting effects prevails depends on the binding energy of the emitted electron. As an example, we show that at 20keV photon energy, Ne^{+} and Ar^{+} photoions are pushed backward towards the radiation source, while Kr^{+} photoions are emitted forward along the light propagation direction.

Evaluation of the effect of strontium and tungsten carbide on the microstructure evolution, tribological and mechanical behaviour of Al-Zn-Mg-Cu-5Sr-WC metal matrix composite

The present study focused on the experimental investigation of the metallurgical, tribological, and mechanical behavior of the developed Al-Zn-Mg-Cu-Sr-WC (Al7075-Sr-WC) metal matrix composite. The effect of the reinforcements such as strontium and tungsten carbide (WC) along with a 2 wt% magnesium as the wetting agent during the stir casting of the synthesized aluminum metal matrix composite (MMC) was investigated by varying the weight percentages. The microstructure examination was characterized using field emission scanning electron microscopy (FE-SEM), scanning electron microscopy (SEM), X-ray diffraction (XRD), and energy dispersive spectroscopy (EDS) techniques. Wear analysis and mechanical testing were conducted to study the effect of WC particles in the matrix phase by examining their wear rate, tensile strength, proof strength, and hardness values. From the mechanical and tribological tests, it was observed that there was an increase of 55% in hardness and 43% in tensile strength, along with a 31% reduction in wear rate. The secondary phases revealed from XRD analysis lead to more hardness along the refined grain boundaries. The tensile strength of the composite initially increased with a 3 wt% of WC and 5 wt% strontium due to hindrance to the dislocation movement but decreased with more reinforcement particles caused by brittleness. The hard WC particles presence has reduced the wear rate significantly due to its resistance towards abrasive wear and lubricating effect. The unique combination of a grain refiner and a binder helped develop a novel composite with superior characteristics that could replace many aerospace components made up of Al7075 alloy.

Efficacy and Safety Evaluation of Tacrolimus-Eluting Stent in a Porcine Coronary Artery Model.

A drug-eluting stent (DES) is a highly beneficial medical device used to widen or unblock narrowed blood vessels. However, the drugs released by the implantation of DES may hinder the re-endothelialization process, increasing the risk of late thrombosis. We have developed a tacrolimus-eluting stent (TES) that as acts as a potent antiproliferative and immunosuppressive agent, enhancing endothelial regeneration. In addition, we assessed the safety and efficacy of TES through both in vitro and in vivo tests. Tacrolimus and Poly(lactic-co-glycolic acid) (PLGA) were applied to the metal stent using electrospinning equipment. The surface morphology of the stent was examined before and after coating using a scanning electron microscope (SEM) and energy dispersive X-rays (EDX). The drug release test was conducted through high-performance liquid chromatography (HPLC). Cell proliferation and migration assays were performed using smooth muscle cells (SMC). The stent was then inserted into the porcine coronary artery and monitored for a duration of 4weeks. SEM analysis confirmed that the coating surface was uniform. Furthermore, EDX analysis showed that the surface was coated with both polymer and drug components. The HPCL analysis of TCL at a wavelength of 215nm revealed that the drug was continuously released over a period of 4weeks. Smooth muscle cell migration was significantly decreased in the tacrolimus group (54.1% ± 11.90%) compared to the non-treated group (90.1% ± 4.86%). In animal experiments, the stenosis rate was significantly reduced in the TES group (29.6% ± 7.93%) compared to the bare metal stent group (41.3% ± 10.18%). Additionally, the fibrin score was found to be lower in the TES group compared to the group treated with a sirolimus-eluting stent (SES). Similar to SES, TES reduces neointimal proliferation in a porcine coronary artery model, specifically decreasing the fibrins score. Therefore, tacrolimus could be considered a promising drug for reducing restenosis and thrombosis.

Engineering a Hierarchy of Disorder: A New Route to Synthesize High-Performance 3D Nanoporous All-Carbon Materials*.

A new nanoporous amorphous carbon (NAC) structure that achieves both ultrahigh strength and high electrical conductivity, which are usually incompatible in porous materials is reported. By using modified spark plasma sintering, three amorphous carbon phases with different atomic bonding configurations are created. The composite consisted of an amorphous sp2-carbon matrix mixed with amorphous sp3-carbon and amorphous graphitic motif. NAC structure has an isotropic electrical conductivity of up to 12000Sm-1, Young's modulus of up to ≈5GPa, and Vickers hardness of over 900MPa. These properties are superior to those of existing conductive nanoporous materials. Direct investigation of the multiscale structure of this material through transmission electron microscopy, electron energy loss spectroscopy, and machine learning-based electron tomography revealed that the origin of the remarkable material properties is the well-organized sp2/sp3 amorphous carbon phases with a core-shell-like architecture, where the sp3-rich carbon forms a resilient core surrounded by a conductive sp2-rich layer. This research not only introduces novel materials with exceptional properties but also opens new opportunities for exploring amorphous structures and designing high-performance materials.

Multilayered cork-STF composite structures enhanced with laser texturing for impact mitigation

AbstractCork and its composites have shown great potential to be employed in protective equipment, damping, and crashworthy systems. Their sustainability is far more positive than that of the solutions currently used. Recent advances in the development of cork composites with shear thickening fluids (STFs) have demonstrated promising results for impact mitigation, mainly focusing on layered structures. This study investigates disruptive configurations of cork-based multilayered structures strategically enhanced with shear-thickening fluid interfaces. In addition, laser texturing of the cork surface to enhance the STF interaction was also investigated. The samples were then subjected to low-energy impact tests with a hemispherical impactor. Additionally, samples were subjected to scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS) to investigate the interactions with STF and modifications caused by the interaction with the laser beam. Some of the explored configurations substantially reduced the impact force, achieving a maximum reduction of 19.7%, mainly benefiting from the STF incorporation between cork layers and enhanced with laser texturing.