Search

Low-noise fluxgate magnetometers are normally comprised of three separate devices: a power supply, the sensor head/electronics and an analog-to-digital converter (ADC). This paper presents a parallel rod fluxgate magnetometer in a single printed circuit board of size = 5 × 12 cm, weight = 45 g, and sensor head average power dissipation = 40 mW. The open-loop noise spectral density = 5 p T r m s / Hz @ 1 Hz , competitive with state-of-the-art devices. This is realized using a new amorphous wire core material and programmable mixed-signal electronics with low amplifier and ADC noise. We have compared the sensor performance to a low-noise observatory magnetometer and found sub-nT correlation when tracking the Y (East-West) component of the Earth's geomagnetic field. [ABSTRACT FROM AUTHOR]

Electronics today has evolved significantly, including its application in transparent and flexible devices. Flexible electronics offers new product concepts, including low production cost, low energy consumption, and sustainable and environmentally friendly materials. This concept leads to the development of novel materials that realize today's requirements. Incorporating optically transparent and flexible thin-film-based devices into the electronic circuitry helps in maintaining high conductivity along with achieving the similar electronic behavior of the conventional electronic gadgets. Thin-film diodes (TFDs) and thin-film transistors (TFTs) are the core materials to be incorporated as building blocks for flexible devices. Among them, oxide-based thin films have been marked to be significant because of their efficient electrical performance, low temperature processing, and device flexibility. The present article reviews the concepts and application of zinc oxide (ZnO) as the semiconducting material for flexible thin-film devices. We also review flexible and transparent TFDs and TFTs that are based prominently on ZnO as the semiconducting material. Furthermore, the present issues have also been addressed. [ABSTRACT FROM AUTHOR]

X-ray absorption spectroscopy (XAS) is a powerful experimental tool to probe the local structure in materials with the core hole excitations. Here, the oxygen K-edge XAS spectra of the NaCl solution and pure water are computed by using a recently developed GW-Bethe-Salpeter equation approach, based on configurations modeled by path-integral molecular dynamics with the deep-learning technique. The neural network is trained on ab initio data obtained with strongly constrained and appropriately normed density functional theory. The observed changes in the XAS features of the NaCl solution, compared to those of pure water, are in good agreement between experimental and theoretical results. We provided detailed explanations for these spectral changes that occur when NaCl is solvated in pure water. Specifically, the presence of solvating ion pairs leads to localization of electron-hole excitons. Our theoretical XAS results support the theory that the effects of the solvating ions on the H-bond network are mainly confined within the first hydration shell of ions, however beyond the shell the arrangement of water molecules remains to be comparable to that observed in pure water. [ABSTRACT FROM AUTHOR]

Antibiotics are commonly used as antibacterial medications due to their extensive and potent therapeutic properties. However, the overconsumption of these chemicals leads to their accumulation in the human body via the food chain, amplifying drug resistance and compromising immunity, thus presenting a significant hazard to human health. Antibiotics are classified as organic pollutants. Therefore, it is crucial to conduct research on precise methodologies for detecting antibiotics in many substances, including food, pharmaceutical waste, and biological samples like serum and urine. The methodology described in this research paper introduces an innovative technique for producing nanoparticles using silica as the shell material, iron oxide as the core material, and carbon as the shell dopant. By integrating a carbon-doped silica shell, this substance acquires exceptional fluorescence characteristics and a substantial quantum yield value of 80%. By capitalising on this characteristic of the substance, we have effectively constructed a fluorescent sensor that enables accurate ofloxacin analysis, with a detection limit of 1.3 × 10-6 M and a linear range of concentrations from 0 to 120 × 10-6 M. We also evaluated the potential of CSIONPs for OLF detection in blood serum and tap water analysis. The obtained relative standard deviation values were below 3.5%. The percentage of ofloxacin recovery from blood serum ranged from 95.52% to 103.28%, and from 89.9% to 96.0% from tap water. [ABSTRACT FROM AUTHOR]

Effects of cores types on non-solvent displacement nonaqueous precipitation synthesis of core-shell structured materials were investigated via taking case study on effects of carbon sources on C@ZrSiO 4 preparation. The influencing mechanism of carbon sources was investigated via XRD, FE-SEM, TEM and the CIELAB colorimeter. The results show that the optimized carbon source for non-solvent displacement nonaqueous precipitation synthesis of C@ZrSiO 4 is amorphous and isolated spheroid-like carbon source. Neither layer-structured particle nor sheet-like particle can be effectively encapsulated through non-solvent displacement nonaqueous precipitation method. The shell layer is difficult to be effectively encapsulated on the edges of the around of corresponding particle. In comparison with the higher crystallinity core, the amorphous core is more favorable for encapsulation. The core materials selection principles discovered in this work are expected to be widely referred in the preparation of other core-shell structural materials. [ABSTRACT FROM AUTHOR]

White dwarf stars frequently experience external pollution by heavy elements, and yet the intrinsically carbon-enriched DQ spectral class members fail to exhibit this phenomenon, representing a decades-old conundrum. This study reports a high-resolution spectroscopic search for Ca  ii in classical DQ white dwarfs, finding that these stars are stunted both in pollution frequency and heavy element mass fractions, relative to the wider population. Compared to other white dwarf spectral classes, the average external accretion rate is found to be at least three orders of magnitude lower in the DQ stars. Several hypotheses are considered which need to simultaneously account for (i) an apparent lack of accreted metals, (ii) a dearth of circumstellar planetary material, (iii) an observed deficit of unevolved companions in post-common envelope binaries, (iv) relatively low helium mass fractions, and remnant masses that appear smaller than for other spectral classes, (v) a high incidence of strong magnetism, and (vi) modestly older disc kinematics. Only one hypothesis is consistent with all these constraints, suggesting DQ white dwarfs are the progeny of binary evolution that altered both their stellar structures and their circumstellar environments. A binary origin is already suspected for the warmer and more massive DQ stars, and is proposed here as an inclusive mechanism to expose core carbon material, in a potential evolutionary unification for the entire DQ spectral class. In this picture, DQ stars are not descended from DA or DB white dwarfs that commonly host dynamically active planetary systems. [ABSTRACT FROM AUTHOR]

An orthogonal experiment was designed to prepare different UV topcoat microcapsules by adjusting the mass ratio of wall material to core material, HLB value of emulsifier, reaction temperature, and reaction time of UV topcoat microcapsule. By testing the morphology and multiple properties of UV topcoat microcapsules, it was found that the biggest factor affecting the synthesis of UV topcoat microcapsules is the emulsifier HLB value. In order to further optimize the performance of UV topcoat microcapsules, a single-factor experiment was conducted with the emulsifier HLB value as the variable, and it was found that the UV topcoat microcapsules achieved the best performance when the emulsifier HLB value was 10.04. The optimal UV topcoat microcapsules were added to the UV topcoat at different amounts to prepare UV topcoat paint films. Through testing the various properties of the UV topcoat paint film, it was determined that the performance of the UV topcoat paint film was optimal when the amount of UV topcoat microcapsules added to the UV topcoat was 4.0%. The optical properties of the UV topcoat paint film were tested, and the effect of UV topcoat microcapsules on the color difference and glossiness of the UV topcoat paint film was not significant. The tensile and self-healing performance of UV topcoat microcapsules were tested. UV topcoat microcapsules can enhance the toughness of the UV topcoat paint film to a certain extent, suppress the generation of microcracks, and have a good self-healing effect. The results provide experimental support for the preparation of microcapsules using UV coatings as core materials for the self-healing of UV coatings. [ABSTRACT FROM AUTHOR]

The development of stretchable electronic devices is a critical area of research for wearable electronics, particularly electronic textiles (e-textiles), where electronic devices embedded in clothing need to stretch and bend with the body. While stretchable electronics technologies exist, none have been widely adopted. This work presents a novel and potentially transformative approach to stretchable electronics using a ubiquitous structure: the helix. A strip of flexible circuitry ('e-strip') is twisted to form a helical ribbon, transforming it from flexible to stretchable. A stretchable core—in this case rubber cord—supports the structure, preventing damage from buckling. Existing helical electronics have only extended to stretchable interconnects between circuit modules, and individual components such as printed helical transistors. Fully stretchable circuits have, until now, only been produced in planar form: flat circuits, either using curved geometry to enable them to stretch, or using inherently stretchable elastomer substrates. Helical e-strips can bend along multiple axes, and repeatedly stretch between 30 and 50%, depending on core material and diameter. LED and temperature sensing helical e-strips are demonstrated, along with design rules for helical e-strip fabrication. Widely available materials and standard fabrication processes were prioritized to maximize scalability and accessibility. [ABSTRACT FROM AUTHOR]

Developing highly reliable infrared radiation materials with broadband high emissivity at high temperatures, low thermal conductivity, and excellent thermal stability is highly desirable for aerospace thermal protection applications. However, it remains a huge challenge to take into account infrared radiation heat dissipation and blocking heat transfer through low thermal conduction simultaneously. In this work, we reported a broadband high emissivity Ca2+-doped YbCrO 3 ceramic with emissivity above 0.89 at room temperature across the entire range of wavelength (1–14 μm). This doping strategy leads to the introduction of impurity energy levels into the band gap of YbCrO 3 , which increases the possibility of light absorption to promote electron transition, improving the emissivity of the near-infrared band (1–3 μm). Simultaneously, un-equivalent doping induces electron exchange between chromate ceramic ions, which complicates the electronic structure (producing lattice distortion and extra multi-mode vibrations) and reduces the band gap width, thus boosting the emissivity in the mid-infrared band (3–14 μm). More importantly, (Yb 0.8 Ca 0.2)CrO 3 presents a high emissivity (0.76) at an elevated temperature of 1200 °C, together with low thermal conductivity (2.5 W m−1 K−1 at 1000 °C) due to strong phonon scattering. Moreover, the doping-dominating phase stabilization effect contributes to impressive thermal stability (stable at 1300 °C for 50 h) and a high coefficient of thermal expansion (9.0–9.5 × 10−6 K−1), which makes it suitable for long-term high-temperature thermal protection application. All these merits render the development of thermally stable high-temperature infrared radiation ceramic materials core competitive. [ABSTRACT FROM AUTHOR]

Rigid lignin foam is prepared by a baking method using kraft lignin as the sole source. The eco-forming process involved cold-pressing kraft lignin powder into a solid block, heating the solid block to form lignin foam, and finally curing and cooling the lignin foam to obtain an open-cell, rigid foam. Both adsorbed water and water generated from the dehydration of hydroxyl groups in the lignin served as the blowing agent in this baking method. It was found that as the moisture content of lignin decreased, the foam densities increased, the mean bubble sizes decreased, and the bubble size distributions became narrower. Foam morphology showed an open cell structure and a wide cell volume distribution. The results suggest that controlling the moisture content in raw lignin allows for the control of the pore structure of the lignin foam. Based on their unique properties, lignin foam materials hold great promise in many applications especially as core insulation materials for structural insulated panels (SIPs). [ABSTRACT FROM AUTHOR]

In this study, the insertion of fluorine into LiFePO4 was carried out under molecular fluorine F2 at different temperatures. The reactivity strongly depends on the applied fluorination temperature, leading to very different products: core delithiation of the material is observed at low temperatures with the formation of a LiF shell around particles, while the material decomposes to gradually form a mixture of α-FeF3 and α-Li3FeF6 iron fluorides at higher temperatures. A second thermal treatment under N2 leads to the formation of LiFePO4F in a new way that has not been reported before. Supported by X-ray diffraction, Raman, infrared, Mössbauer spectroscopies, 7Li nuclear magnetic resonance and electrochemical characterization of the different materials, this report demonstrates various fluorination mechanisms for LiFePO4, from chemical delithiation to the stable pure fluorinated form LiFePO4F and illustrates an innovative method that can be extended to obtain the triphylite form of NaFePO4. [ABSTRACT FROM AUTHOR]

High power conversion efficiency (PCE) and long-term stability are essential prerequisites for the commercialization of polymer solar cells (PSCs). Small-molecule acceptors (SMAs) are core materials that have led to recent, rapid increases in the PCEs of the PSCs. However, a critical limitation of the resulting PSCs is their poor long-term stability. Blend morphology degradation from rapid diffusion of SMAs with low glass transition temperatures (Tgs) is considered the main cause of the poor long-term stability of the PSCs. The recent emergence of oligomerized SMAs (OSMAs), composed of two or more repeating SMA units (i.e., dimerized and trimerized SMAs), has shown great promise in overcoming these challenges. This innovation in material design has enabled OSMA-based PSCs to reach impressive PCEs near 19% and exceptional long-term stability. In this review, we summarize the evolution of OSMAs, including their research background and recent progress in molecular design. In particular, we discuss the mechanisms for high PCE and stability of OSMA-based PSCs and suggest useful design guidelines for high-performance OSMAs. Furthermore, we reflect on the existing hurdles and future directions for OSMA materials towards achieving commercially viable PSCs with high PCEs and operational stabilities. [ABSTRACT FROM AUTHOR]

Rock specimens of the reservoir's core material from the Chayanda oil and gas condensate field (OGCF) were tested using the Triaxial Independent Load Test System of the Ishlinsky Institute for Problems in Mechanics, Russian Academy of Sciences (TILTS) in order to experimentally study the effect exerted by desalinization of reservoir rocks on their strain, strength, and filtration characteristics. According to the study data, desalinization considerably increases a rock permeability. Strain and strength properties of the studied rocks change toward softening (except for an internal friction angle), nevertheless remaining relatively high. Based on the experimental physical modeling of the pressure reducing process at the bottom of a horizontal well using TILTS, a slight decrease in elastic and strength properties of the Chayanda OGCF reservoir rocks after their desalinization should not affect the stability of the well's walls. The results obtained make it possible to draw the important practical conclusion: when operating the field at the stage of salt washing out due to water filtration under the operation process, a dramatic increase in the risks related to reservoir destruction and higher sand production should not be expected. [ABSTRACT FROM AUTHOR]

Adenosine, as a water-soluble active substance, has various pharmacological effects. This study proposes a layer-by-layer assembly method of composite wall materials, using hydroxypropyl- β -cyclodextrin as the inner wall and whey protein isolate as the outer wall, to encapsulate adenosine within the core material, aiming to enhance adenosine microcapsules' stability through intermolecular interactions. By combining isothermal titration calorimetry with molecular modeling analysis, it was determined that the core material and the inner wall and the inner wall and the outer wall interact through intermolecular forces. Adenosine and hydroxypropyl- β -cyclodextrin form an optimal 1:1 complex through hydrophobic interactions, while hydroxypropyl- β -cyclodextrin and whey protein isolate interact through hydrogen bonds. The embedding rate of AD/Hp- β -CD/WPI microcapsules was 36.80%, and the 24 h retention rate under the release behavior test was 76.09%. The method of preparing adenosine microcapsules using composite wall materials is environmentally friendly and shows broad application prospects in storage and delivery systems with sustained release properties. [ABSTRACT FROM AUTHOR]

In this work, fringing effect is studied on planar transformers for various frequencies, air gap lengths, core materials and core geometries to aid engineers in choosing the best transformer design with least fringing losses. Using finite element modelling, fringing losses were analysed for four different core geometries, namely EE, EI, ER and ETD, with varying core widths to estimate a generalized fringing losses equation. Emerging core materials like amorphous and nanocrystalline materials were analysed in addition to the common ferrite material for the core of the transformer. Simulations were performed for frequencies ranging from 50 to 400 kHz and air gap lengths varying from 0.05 mm to 0.25 mm. Using curve fitting, an equation was developed to estimate fringing losses. Fringing losses of a planar transformer were found to be directly dependent on its frequency, magnetic flux density, air gap length and core width. The fundamental difference of the proposed equation from the traditional fringing losses formula is that fringing losses were found to be proportional to the square of the frequency instead of the first power of frequency. Fringing losses were also calculated with the traditional formula, to analyse the improvement obtained with the proposed finite element modelling-based equation. It was observed that the proposed formula gave fringing losses results with a minimal error of about 9% for a range of lower and higher frequencies, whereas the traditional formula accounted for about 45% error for higher frequencies and around 11% error for lower frequencies. [ABSTRACT FROM AUTHOR]

The astaxanthin nanocapsules (ASX-LNC) was prepared by high-pressure homogenization technology, the microstructure, stability, antioxidant activity, and in vitro release characteristics of ASX-LNC were characterized and evaluated. The ASX-LNC comprised a core material and wall materials. The core material was composed of astaxanthin oil, and the wall materials were composed of β-cyclodextrin, decapolyglycerol monooleate, soybean lecithin (PC60), glycerol, and deionized water. The mean particle size of the ASX-LNC was 206.9 ± 2.8 nm, and the polydispersity index (PdI) value was 0.218 ± 0.026. The zeta potential of ASX-LNC was −26.16 ± 0.87 mV. The loading amount of ASX-LNC was 0.546%±0.032%, and the encapsulation efficiency was 99.65%±0.13%, indicating that the preparation process was feasible. The stability of ASX-LNC was determined under different conditions, indicating good stability of the ASX-LNC. In antioxidant research, the inhibition rate of free radicals of ASX-LNC was 91.03 ± 0.87% under 250 μg/mL for 30 min, and the inhibition rate of free radicals of astaxanthin ethanol solution was 90.83 ± 1.37%. The antioxidant capacity of astaxanthin was not affected by the encapsulation, which demonstrated the effect of prolonging the release of active ingredients due to the protection of the biological activity of astaxanthin by encapsulation. Compared with the astaxanthin ethanol solution, the ASX-LNC had a slow-release effect and could prolong the action time of active substances. Overall, ASX-LNC is a potential carrier for application in food and health products, which can control the release of active substances. [ABSTRACT FROM AUTHOR]

In this paper, we report on fabricating optical fibers with a controlled process of crystallization core during the drawing process. The research and synthesis of the core material of silica-germanium-antimony oxide glass were discussed. We also investigated the optical and luminescence properties were in relation to concentrating Eu 2 O 3 and P 2 O 5. Based on this investigation, we selected the most promising material for optical fiber core. In the next step, we drew optical fibers using a well-known rod-in-tube method. After drawing, we examine the optical fibers for luminescence shape changes. We observed a promising similarity between optical fibers and heat-treated samples with confirmed nanocrystals. Finally, XRD and TEM measurements confirm EuPO 4 nanocrystals at the core of the optical fiber. Highlighting the successful control of crystallization in the one-step method used to draw optical fibers. [ABSTRACT FROM AUTHOR]

Sufficient homogeneity of the certified parameter(s) over the whole fill series of a matrix reference material (RM) is a fundamental quality criterion. In practice, the heterogeneity of the target parameter is evaluated, whereby a relative value can be calculated of how much the target parameter is varying over the RM-batch. A high degree of homogeneity (low heterogeneity) is an inherent quality mark of a good RM. Here, we report how challenging matrix RMs were produced by using particle suspensions at the core of the material processing step. The examples of matrix RMs produced span from whole water reference materials for persistent organic pollutants, PM2.5-like atmospheric dust certified for specific ions to microplastic RMs. Most of these RMs were subsequently used in different phases of analytical method development or for method validation. Common to all these matrices is that they cannot be easily mixed, handled, or dosed to prepare larger sample batches. In all cases, a continuously stirred suspension of particles was used during material processing. In general, relative between-bottle heterogeneities from 1.6 to 6% were achieved for the target parameters in these matrix presentations. Concerning developments of new CRMs in emerging fields, the co-dependence between the availability of validated analytical methods with good repeatability and testing materials with a known and high homogeneity of the target parameter(s) becomes particularly challenging. This situation is an RM/Method causality dilemma. To overcome that hurdle, strategies are proposed for stepwise processes where RM producers and a network of analytical method developers could work hand in hand. In addition, development of a portfolio of inexpensive and well-homogenised common samples coupled with a reporting interface is suggested. This would benefit method developers and RM producers alike. As more and more data is compiled for a specific matrix, it paves the way for new and challenging RMs that can later be used by a wider community. [ABSTRACT FROM AUTHOR]

The state detection of power cables is very important to ensure the reliability of the power supply. Traditional sensors are mostly based on electric field detection. The operation is complex, and its efficiency needs to be improved. This paper optimizes the design and development of the magnetic field detection sensor for AC power cables. First, through the establishment of the magnetic field sensor model, it is determined that permalloy is the material of the magnetic core, the optimal aspect ratio of the magnetic core is 20, and the ratio of coil length to core length is 0.3. Second, the coil-simulation model is established, and it is determined that the optimal number of turns of the coil is 11,000 turns, the diameter of the enameled copper wire is 0.08 mm, and the equivalent magnetic field noise of the sensor is 0.06 pT. Finally, the amplifying circuit based on negative magnetic flux feedback is designed, the sensor is assembled, and the experimental circuit is built for the sensitivity test. The results show that the sensitivity of the magnetic field sensor is 327.6 mV/μT. The sensor designed in this paper has the advantages of small size, high sensitivity, ease of carry, and high reliability. [ABSTRACT FROM AUTHOR]

In this paper, the preparation technique of lavender essential oil microcapsules and the construction method of aromatic textiles were expounded, and the research status of bed curtains and lavender microcapsules at home and abroad was analyzed and studied from the perspective of application in textiles. The application of lavender essential oil to bed curtains through the microcapsule technique was put forward to allow lavender essential oil to play its role of helping sleep in bed curtains. This paper expounded the material selection and preparation technique of lavender microcapsule agents, and put forward the preparation method of microcapsules with mixed solutions of pure Chinese medicine extracts and natural essences as core material and high-viscosity epoxy resin as wall materials. The post-processing techniques and the spray ironing method for clothing were studied and developed, and these techniques and methods were applied to bed curtains, and good results were obtained. [ABSTRACT FROM AUTHOR]

Tung oil (TO) microcapsules (MCs) with a poly(urea-formaldehyde) (PUF) shell were synthesized via one-step in situ polymerization, with the addition of graphene nanoplatelets (GNPs) (1–5 wt. %). The synergistic effects of emulsifiers between gelatin (gel) and Tween 80 were observed, with gel chosen to formulate the MCs due to its enhanced droplet stability. SEM images then displayed an increased shell roughness of the TO-GNP MCs in comparison to the pure TO MCs due to the GNP species on the shell. At the same time, high-resolution transmission electron microscopy (TEM) images also confirmed the presence of GNPs on the outer layer of the MCs, with the stacked graphene layers composed of 5–7 layers with an interlayer distance of ~0.37 nm. Cross-sectional TEM imaging of the MCs also confirmed the successful encapsulation of the GNPs in the core of the MCs. Micromanipulation measurements displayed that the 5% GNPs increased the toughness by 71% compared to the pure TO MCs, due to the reduction in the fractional free volume of the core material. When the MCs were dispersed in an epoxy coating and applied on a metallic substrate, excellent healing capacities of up to 93% were observed for the 5% GNP samples, and 87% for the pure TO MC coatings. The coatings also exhibited excellent corrosion resistance for all samples up to 7 days, with the GNP samples offering a more strenuous path for the corrosive agents. [ABSTRACT FROM AUTHOR]

Since their first discovery in the late 1960s, gamma-ray bursts have attracted an exponentially growing interest from the international community due to their central role in the most highly debated open questions of the modern research of astronomy, astrophysics, cosmology, and fundamental physics. These range from the intimate nuclear composition of high-density material within the core of ultra-dense neuron stars, to stellar evolution via the collapse of massive stars, the production and propagation of gravitational waves, as well as the exploration of the early universe by unveiling the first stars and galaxies (assessing also their evolution and cosmic re-ionization). GRBs in the past ∼50 years have stimulated the development of cutting-edge technological instruments for observations of high-energy celestial sources from space, leading to the launch and successful operations of many different scientific missions (several of them still in data-taking mode currently). In this review, we provide a brief description of the GRB-dedicated missions from space being designed and developed for the future. The list of these projects, not meant to be exhaustive, shall serve as a reference to interested readers to understand what is likely to come next to lead the further development of GRB research and the associated phenomenology. [ABSTRACT FROM AUTHOR]

This paper investigates the vibration characteristics of a sandwich nanosensor plate composed of piezoelectric materials, specifically barium and cobalt, in the upper and lower layers, and a core material consisting of either ceramic (silicon nitride) or metal (stainless steel) foams reinforced with graphene (GPRL). The study utilized the novel sinosoidal higher-order deformation theory and nonlocal strain gradient elasticity theory. The equations of motion for nanosensor sandwich graphene were derived using Hamilton's principle, considering the thermal, electroelastic, and magnetostrictive characteristics of the piezomagnetic surface plates. These equations were then solved using the Navier method. The core element of the sandwich nanosensor plate can be represented using three distinct foam variants: a uniform foam model, as well as two symmetric foam models. The investigation focused on analyzing the dimensionless fundamental natural frequencies of the sandwich nanosensor plate. This analysis considered the influence of three distinct foam types, the volumetric graphene ratio, temperature variation, nonlocal parameters, porosity ratio, electric and magnetic potential, as well as spring and shear viscoelastic support. Furthermore, an analysis was conducted on the impact of the metal and ceramic composition of the central section of the sandwich nanosensor plate on its dimensionless fundamental natural frequencies. In this context, the use of ceramic as the central material results in a mean enhancement of 33% in the fundamental natural frequencies. In contrast, the incorporation of graphene into the core material results in an average enhancement of 27%. The thermomechanical vibration behavior of the nanosensor plate reveals that the presence of graphene-supported foam and a viscoelastic support structure in the core layer leads to an increase in thermal resistance. This increase is dependent on factors such as the ratio of graphene, porosity ratio of the foam, and parameters of the viscoelastic support. Metal foam or ceramic foam has been found to enhance thermal resistance when compared to solid metal or ceramic core materials. The analysis results showed that it is important to take into account the temperature-dependent thermal properties of barium and cobalt, which are piezo-electromagnetic materials, and the core layer materials ceramics and metal, as well as the graphene used to strengthen the core. The research is anticipated to generate valuable findings regarding the advancement and utilization of nanosensors, transducers, and nano-electromechanical systems engineered for operation in high-temperature environments. [ABSTRACT FROM AUTHOR]

Based on the previous research on the energy absorption of foam metal materials with different structures, a composite blast-resistant energy-absorbing material with a flexible core layer was designed. The material is composed of three different fiber materials (carbon fiber, aramid fiber, and glass fiber) as the core layer and foamed iron–nickel metal as the front and rear panels. The energy absorption characteristics were tested using a self-built gas explosion tube network experimental platform, and the energy absorption effects of different combinations of blast-resistant materials were analyzed. The purpose of this paper is to evaluate the performance of blast-resistant materials designed with flexible fiber core layers. The experimental results show that the composite structure blast-resistant material with a flexible core layer has higher energy absorption performance. The work performed in this paper shows that the use of flexible core layer materials has great research potential and engineering research value for improving energy absorption performance, reducing the mass of blast-resistant materials, and reducing production costs. It also provides thoughts for the research of biomimetic energy-absorbing materials. [ABSTRACT FROM AUTHOR]

With the fast development of the cold chain transportation industry, the traditional refrigeration method results in significant energy consumption. To address the national call for energy saving and emission reduction, the search for a new type of energy storage material has already become a future development trend. According to the national standard GB/T28577 for the classification and basic requirements of cold chain logistics, the temperature in frozen logistics is typically below −18 °C. In this study, n-undecane with a phase change temperature of −26 °C is chosen as the core material of microcapsules. Poly(methyl methacrylate) is applied as the shell material, with n-undecane microcapsules being prepared through suspension polymerization for phase change cold storage materials (MEPCM). Using characterization techniques including SEM, DSC, FTIR, and laser particle size analysis, the effects of three types of emulsifiers (SMA, Tween-80, Tween-80/span-80 (70/30)), SMA emulsifier dosage, core–shell ratio, and emulsification rate on the thermal performance and micro-surface morphology of n-undecane/PMMA microcapsules were studied. The results indicate that when comparing SMA, Tween-80, and Tween-80/span-80 (70/30) as emulsifiers, the dodecane/PMMA microcapsules prepared with SMA emulsifier exhibit superior thermal performance and micro-surface morphology, possessing a complete core–shell structure. The optimal microstructure and the highest enthalpy of phase change, measuring 120.3 kJ/kg, are achieved when SMA is used as the emulsifier with a quantity of 7%, a core-to-wall ratio of 2.5:1, and an emulsification speed of 2000 rpm. After 200 hot and cold cycles, the enthalpy of phase change decreased by only 18.6 kJ/kg, indicating the MEPCM thermal performance and cycle life. In addition, these optimized microcapsules exhibit favorable microstructure, uniform particle size, and efficient energy storage, making them an excellent choice for the refrigeration and freezing sectors. [ABSTRACT FROM AUTHOR]

By tailoring and optimizing the structure of core or shell material, complete alteration of properties of the material can be obtained. Herein, we have reported synthesis of CaCu3Ti4O12@CoFe2O4 particles through the chemical co-precipitation route. CaCu3Ti4O12@CoFe2O4 particles consist of CaCu3Ti4O12 (~ 200 nm) as a core and CoFe2O4 as a shell of 2.5 nm. The prepared composites are characterized with appropriate characterization tools. The morphological results confirm the proper formation of core shell structure where CaCu3Ti4O12 and CoFe2O4 act as a core and shell, respectively. The greater CCTO content composites exhibited promising relative permittivity of 8.2 × 103 at 700 °C sintering temperature (8 h) at frequency 40 to 8 MHz. When CaCu3Ti4O12@CoFe2O4 undergoes heat treatment, it leads to the removal of oxalic acid. However, a weight loss of 8.3% is obtained for CCTO-coated composites that is quite low as compared to ~ 11% weight loss obtained in pristine CFO. The removal of organic groups significantly contributed to the increase in dielectric properties. These results imply that the development of CaCu3Ti4O12@CoFe2O4 core shell structure paves the wave for high-performance devices. [ABSTRACT FROM AUTHOR]

The features of uranium mining on Kazakhstan's enterprises have been examined, and uranium deposits located in the Syrdarya and Shu-Sarysu depressions have been described. Actual and projected data on the development of technological blocks in areas with complex geological structures have been analyzed and compared. Core samples were collected and, using X-ray diffraction analysis, quantitative and qualitative characteristics as well as mineral compositions of ores from various productive horizons of uranium deposits in the Syrdarya and Shu-Sarysu depressions were comparatively analyzed. It was determined that the ores in the Syrdarya depression are relatively homogeneous compared to those in the Shu-Sarysu depression, although in some places, clay minerals and gypsum are present, which hinder the uranium leaching processes. In the ores of the Shu-Sarysu depression, clay minerals that impede the uranium leaching processes are present in certain areas. Microscopic analysis of core material samples using a LEICA DM 2500 P microscope revealed particle sizes and shapes, as well as their distribution within the structure of host rocks in the productive horizon. Using X-ray diffraction analysis, mineral compositions of sediment-forming components during uranium well mining in the considered productive horizons were determined and comparatively analyzed. It was established that in the geotechnological wells of the Syrdarya depression, sediments of predominantly chemical origin, such as gypsum, are formed. However, in the geotechnological wells of the Shu-Sarysu depression, sediments of mechanical origin, consisting predominantly of quartz particles and clay minerals, are formed. Based on the obtained data, a method for intensifying underground uranium leaching in complex geological conditions has been developed, which involves dissolving sediment formations and increasing the oxidative–reductive potential of the leaching solution. The proposed and experimentally substantiated universal methodology for enhancing uranium well production involves the dissolution and prevention of precipitation using hydrofluoric acid solutions, as well as the oxidation of uranium dioxide with hydrogen peroxide. [ABSTRACT FROM AUTHOR]

Photonic Crystal Fiber (PCF) constructions, controlled light propagation for measuring amplitude, phase, polarization and wavelength of the spectrum, and PCF-incorporated interferometry techniques are the foundations upon which sensors operate. But the existing PCF techniques have very large stretching that tends to be difficult to align due to the cross-polarization mode of the optical fiber structure. Hence, the novel Polymer graphene-based Hexagonal cladding is designed by using a hexagonal hollowed core and a cladding material of Polymethyl methacrylate reinforced with gyroidal graphene which increases confinement strength. Once the crystal structure is designed, normally the presence of substrate the Q-factors is degraded. On substrates, Q-factors are enhanced by fine-tuning the position of the neighboring holes. Hence, the novel Bilayer Grating Stratum solves the degrading issues in Q-factors, which utilizes a Silicon polyamide-coated FBG in the crystal that is incorporated using the Femto-laser technique thereby increasing the wavelength tenability. To identify the electric field pattern, the designed structure is simulated in COMSOL software. Thus, the proposed system has a high sensitivity of 22 with a low material loss of 0.1% and a low response time of 0.2 s. [ABSTRACT FROM AUTHOR]

Piezoelectric ultrasonic energy harvesters (PUEHs) have recently attracted increasing attention. For minimizing the energy losses during energy transfer, it is crucial for core piezoelectric materials to maintain high piezoelectric coefficient (d 33), mechanical quality factor (Q m), and piezoelectric voltage coefficient (g 33). Herein, a simple way of hardening strategy improves the piezoelectric properties of KNN-based ceramics, combined with optimizing grain growth. The enhanced d 33 (∼340 pC/N), high Q m (∼211) and T C (∼305 °C) are obtained simultaneously in this system, accompanied by superior d 33 × g 33 =8770×10−15 m2/N. Through variable temperature resonance test, the polarization rotation diversity caused by phase structure difference is found to closely related to the temperature stability of Q m value. A prototype of PUEH device was further designed and fabricated, with adjustable ultrasound-induced output voltage up to 8.2 V. Our work exhibits an effective way to improve performance of PUEHs by optimizing piezoelectric materials, which is helpful for further developing PUEHs. [ABSTRACT FROM AUTHOR]

Ceramic stereolithography 3D printing technology has demonstrated great potential in alumina core manufacturing for advanced turbine blade casting. However, there have been very few photosensitive material formulas specifically designed for alumina core fabrications. Herein, we present the design of a 3D printable ceramic paste based on bimodal particle size distributions for additive manufacturing of high‐quality alumina cores. The coarse particles in the paste remain in their original shape while the fine particles transform into platelet‐like particles during sintering. The effects of coarse particles, platelet‐like particles, and grain growth on maintaining porosity and limiting shrinkage rates are studied. Furthermore, the vacuum sintering process is found to be beneficial for core material properties. The physical properties tests verify that the newly designed alumina paste in this work can meet the application requirement, which is superior to the previous research. [ABSTRACT FROM AUTHOR]

In this letter, the effects of various material definition approaches for stator and rotor cores on the no‐load electromagnetic field calculations of a 34 MW tubular hydrogenerator are investigated, utilizing the transient motion electromagnetic field time‐step finite element (FE) method. The findings indicate that employing a linear simplified definition for the stator core material maintains high accuracy and rationality in the calculation results of the no‐load electromagnetic field and voltage waveform while offering substantially greater computational efficiency than the non‐linear definition method. Conversely, using a linear simplified definition for the magnetic pole core material of the rotor significantly increases the error margin in the results, rendering them unacceptable. [ABSTRACT FROM AUTHOR]

This research aimed to assess the stress distribution in lower premolars that were obturated with BioRoot RCS or AH Plus, with or without gutta percha (GP), and subjected to vertical and oblique forces. One 3D geometric model of a mandibular second premolar was created using SolidWorks software. Eight different scenarios representing different root canal filling techniques, single cone technique with GP and bulk technique with sealer only with occlusal load directions were simulated as follows: Model 1 (BioRoot RCS sealer and GP under vertical load [VL]), Model 2 (BioRoot RCS sealer and GP under oblique load [OL]), Model 3 (AH Plus sealer with GP under VL), Model 4 (AH Plus sealer with GP under OL), Model 5 (BioRoot RCS sealer in bulk under VL), Model 6 (BioRoot RCS in bulk under OL), Model 7 (AH Plus sealer in bulk under VL), and Model 8 (AH Plus sealer in bulk under OL). A static load of 200 N was applied at three occlusal contact points, with a 45° angle from lingual to buccal. The von Mises stresses in root dentin were higher in cases where AH Plus was used compared to BioRoot RCS. Furthermore, shifting the load to an oblique direction resulted in increased stress levels. Replacing GP with sealer material had no effect on the dentin maximum von Mises stress in BioRoot RCS cases. Presence of a core material resulted in lower stress in dentin for AH Plus cases, however, it did not affect the stress levels in dentin for cases filled with BioRoot RCS. Stress distribution in the dentin under oblique direction was higher regardless of sealer or technique used. [ABSTRACT FROM AUTHOR]

The present research investigates optimizing the impact resistance of functionally graded sandwich structures using experimental and numerical approaches. The low-velocity impact (LVI) responses of functionally graded sandwich composite (FGSC) with different configurations with skin material jute/rubber/jute (JRJ) and core material having epoxy and sea sand by volume fraction of sea sand at 0%, 10%, 20%, and 30%. Sandwich structures were impacted with LVI (5.89, 10.92, and 15.18 m/s), with the impactor dropped from heights of 0.5, 1, and 1.5 m with precompressed spring loads. FGSC samples are considered a deformable body, and the impactor is modeled as a rigid body using commercially accessible dynamic explicit software. The burnout test and weight method were used to test the core's gradience; both methods' results substantially matched, and the variance in gradation could be observed. The proposed sandwich structure characteristics are examined by energy absorption, peak force, energy loss percentage, and coefficient of restitution. Results showed that SC30S provides greater energy absorption and superior damage resistance when tested on LVI. To evaluate the accuracy of experimental findings in predicting the indentation behavior of the sandwich structure, the finite element analysis was used to compare with the experimental results. According to the examination of these proposed FGSC overall performance, they could potentially be employed as sacrificial materials for LVI applications like claddings to shield major structural components. The systematic approach used in this work serves as a standard for choosing and using FGSC effectively for LVI applications. Highlights • Low-velocity impact behavior of sandwich structures was investigated. • Combining flexible skin and epoxy core enhances energy absorption. • Based on impact energy levels, impact damage areas were determined. • Examined sandwich structure advantages in structural and aerospace uses. • In terms of time and cost, the numerical analysis method would be useful. [ABSTRACT FROM AUTHOR]

Liver metastasis is a major obstacle in treating aggressive cancers, and current therapeutic options often prove insufficient. To overcome these challenges, there has been growing interest in ultrasound-mediated drug delivery using lipid-shelled microbubbles (MBs) and nanobubbles (NBs) as promising strategies for enhancing drug delivery to tumors. Our previous work demonstrated the potential of Doxorubicin-loaded C 3 F 8 NBs (hDox-NB, 280 ± 123 nm) in improving cancer treatment in vitro using low-frequency unfocused therapeutic ultrasound (TUS). In this study, we investigated the pharmacokinetics and biodistribution of sonicated hDox-NBs in orthotopic rat liver tumors. We compared their delivery and therapeutic efficiency with size-isolated MBs (hDox-MB, 1104 ± 373 nm) made from identical shell material and core gas. Results showed a similar accumulation of hDox in tumors treated with hDox-MBs and unfocused therapeutic ultrasound (hDox-MB + TUS) and hDox-NB + TUS. However, significantly increased apoptotic cell death in the tumor and fewer off-target apoptotic cells in the normal liver were found upon the treatment with hDox-NB + TUS. The tumor-to-liver apoptotic ratio was elevated 9.4-fold following treatment with hDox-NB + TUS compared to hDox-MB + TUS, suggesting that the therapeutic efficacy and specificity are significantly increased when using hDox-NB + TUS. These findings highlight the potential of this approach as a viable treatment modality for liver tumors. By elucidating the behavior of drug-loaded bubbles in vivo , we aim to contribute to developing more effective liver cancer treatments that could ultimately improve patient outcomes and decrease off-target side effects. [Display omitted] • Bubble size is a critical factor in ultrasound-mediated drug delivery to tumors. • Nanobubbles excited with ultrasound deliver more drugs to tumors than microbubbles. • Nanobubbles + ultrasound increase apoptotic cell death in tumors while sparing normal liver. [ABSTRACT FROM AUTHOR]

This paper introduces the inertial amplifier viscoelastic tuned mass dampers (IAVTMD). The viscoelastic materials are implanted inside the core material of the inertial amplifier tuned mass dampers. The standard linear solid models are applied mathematically to formulate the viscoelastic material. H 2 and H ∞ optimization mechanisms apply to derive the exact mathematical closed-form formulations for optimal design parameters for novel inertial amplifier viscoelastic tuned mass dampers. The optimum IAVTMD installs at the top of the structures to mitigate the dynamic responses, determining the dynamic responses analytically through transfer function formation. At first, IAVTMD's dynamic response reduction capacity compares with the conventional tuned mass damper's (CTMD) dynamic response reduction capacity. As a result, H 2 optimized IAVTMD's dynamic response reduction capacity is significantly 20.87% and 26.47% superior to two well-established H 2 optimized conventional tuned mass damper's dynamic response reduction capacity. In addition, H ∞ optimized IAVTMD has 15.48% more dynamic response reduction capacity than H ∞ conventional tuned mass damper. H 2 and H ∞ optimized tuned mass damper inerters with optimal closed-form solutions are introduced in this paper. A higher damper mass ratio and a lower inerter mass ratio are recommended to produce H 2 and H ∞ optimized tuned mass damper inerter (TMDI) with a lower frequency and damping ratio in an affordable range. Accordingly, H 2 and H ∞ optimized IAVTMD's dynamic response reduction capacities are significantly 6.94% and 23.29% superior to H 2 and H ∞ optimized TMDI's dynamic response reduction capacity. The closed-form expressions for optimal design parameters of inertial amplifier viscoelastic tuned mass dampers and tuned mass damper inerters are mathematically correct and effective for practical applications. [ABSTRACT FROM AUTHOR]

Honeycomb cores made of phenol resin impregnated paper are widely used in sandwich structures of aircraft. Owing to the rather weak core material, this kind of sandwich is prone to a range of damages as a result of impact loading which may accidentally occur during operation. When employed in aircraft these structures have to be damage tolerant. This means barely visible damages have to be considered in the structural design process. In the standard design process for damage tolerant aircraft structures especially the effect of impacts has to be considered but is mostly investigated on unloaded sandwich components. However, aircraft structures are not completely stress free, even when the aircraft is in parking position. At least the structural weight will cause a permanent static preload. In the literature there are only few investigations dealing with the impact behaviour of preloaded honeycomb sandwich structures. In general, studies on composite structures have shown that tension preloads lead to higher structural impact resistance, while prestressing in compression reduces mechanical properties such as impact strength and stiffness of the structure. For this reason, a compression preload is considered as the more critical load case. In order to evaluate the effect of static compression preloads an experimental study on five different honeycomb sandwich configurations was conducted. The experimental investigations showed that even low preloads cause a higher structural damage area, which results in a lower residual strength of the structure. The results indicated that it is recommendable to consider structural compression preloads in the aircraft structural design process. [ABSTRACT FROM AUTHOR]

For photothermal therapy of cancer, it is necessary to find Ag @TiO2 core-shell nanoparticles that can freely tune the resonance wavelength within the near-infrared biological window. In this paper, the finite element method and the size-dependent refractive index of metal nanoparticles were used to theoretically investigate the effects of the core material, core length, core aspect ratio, shell thickness, refractive index of the surrounding medium, and the particle orientation on the light absorption properties of Ag@TiO2 core-shell nanospheroid and nanorod. The calculations show that the position and intensity of the light absorption resonance peaks can be freely tuned within the first and second biological windows by changing the above-mentioned parameters. Two laser wavelengths commonly used in photothermal therapy, 808 nm (first biological window) and 1064 nm (second biological window), were selected to optimize the core length and aspect ratio of Ag@TiO2 core-shell nanospheroid and nanorod. It was found that the optimized Ag@TiO2 core-shell nanospheroid has a stronger light absorption capacity at the laser wavelengths of 808 nm and 1064 nm. The optimized Ag@TiO2 core-shell nanoparticles can be used as ideal therapeutic agents in photothermal therapy. [ABSTRACT FROM AUTHOR]

The titanium-stabilized austenitic stainless steel Fe-15Cr-15Ni, which shows enhanced resistance to irradiation swelling compared with more traditional 316Ti, has been selected as a core material for fast reactors. Data on the evolution of irradiation swelling in 15-15Ti steels at very high doses, which cannot be easily achieved by neutron irradiation, are still lacking. In this paper, the swelling behavior of the titanium-modified austenitic stainless steel 15-15Ti was investigated by pre-implantation of He at room temperature followed by Ni-ion irradiation at 580 °C to peak doses of 120, 240 and 400 dpa. Relatively small cavities were observed in the zone of helium implantation, while large cavities appeared in the region near the damage peak. A correction formula for the dpa curve was proposed and applied to samples with large swelling. It was found that the steady-state swelling rate of 15-15Ti remains at ~1%/dpa even at high doses. By comparing the swelling data of the helium-implanted and helium-free regions at same doses, 70 dpa and 122 dpa, the suppression of swelling by excessive helium can be deduced at such doses. [ABSTRACT FROM AUTHOR]

Lauric Acid (LA) phase-change nanocapsules prepared with silver as the shell exhibit excellent energy storage capacity and high thermal conductivity. Still, their functionality could be improved by ensuring uniform morphologies, even the size and thickness of silver particles. In this study, the LA/Ag nanocapsules were prepared under different reductant drop speeds. By adjusting the droplet speed of the reducing agent, the concentration of silver in the solution can be controlled, which affects the nucleation and growth rate of silver particles, thereby influencing the deposition of silver particles on the surface of the core material. The characterization results indicate the successful preparation of high sphericity and uniform-sized LA/Ag nanocapsules. The average diameter of capsules was 117–140 nm, the latent heat was 43.69–47.78 J/g, and the encapsulation efficiency was 80.69–82.53%. As the droplet speed increased, the thickness of the silver shell increased while the encapsulation efficiency decreased. The highest encapsulation efficiency was achieved when the reducing agent dropping speed was 0.03 mL/s. [ABSTRACT FROM AUTHOR]

Activator of G-protein signaling 3 (AGS3; also known as GPSM1), a receptor-independent activator of G-protein signaling, oscillates among defined subcellular compartments and biomolecular condensates (BMCs) in a regulated manner that is likely related to the functional diversity of the protein. We determined the influence of cell stress on the cellular distribution of AGS3 and core material properties of AGS3 BMCs. Cellular stress (oxidative, pHi and thermal) induced the formation of AGS3 BMCs in HeLa and COS-7 cells, as determined by fluorescent microscopy. Oxidative stress-induced AGS3 BMCs were distinct from G3BP1 stress granules and from RNA processing BMCs defined by the P-body protein Dcp1a. Immunoblots indicated that cellular stress shifted AGS3, but not the stress granule protein G3BP1 to a membrane pellet fraction following cell lysis. The stress-induced generation of AGS3 BMCs was reduced by co-expression of the signaling protein Gai3, but not the AGS3-binding partner DVL2. Fluorescent recovery following photobleaching of individual AGS3 BMCs indicated that there are distinct diffusion kinetics and restricted fluidity for AGS3 BMCs. These data suggest that AGS3 BMCs represent a distinct class of stress granules that serve as a previously unrecognized signal processing node. [ABSTRACT FROM AUTHOR]

Performing micromagnetic simulations, we study the efficiency of response of bulk and polycrystalline nickel oxide (NiO) to high-frequency (up to 100 GHz) magnetic fields with relevance to potential application of the antiferromagnet as a core material to high-frequency coils and resonators. NiO is advantageous due to its insulating property and high Néel temperature. Though the dynamical susceptibility of the antiferromagnet is low, the achievable product of susceptibility and frequency ("performance factor") appears to be relatively high, comparable to that of previously considered superferromagnetic systems. This makes NiO a potential core material for operating at extremely-high (sub-THz) frequency. The influence of thermal fluctuations on the susceptibility is estimated to be weak up to room temperature even for a nanocrystalline antiferromagnet, whereas, the magnetic response is linear for much wider ranges of frequencies and field amplitudes than for ferromagnetic and superferromagnetic systems. [ABSTRACT FROM AUTHOR]

• Large column and water tank were used to study the properties of particle layer. • Salt-resistant bentonite showed excellent adsorption capability for heavy metals. • Particle layer showed excellent properties under different depths of seawater. • Particle layer performed well under waste loaded seawater condition. The complex seabed conditions and ocean environment pose significant challenges to the material selection and construction of bottom liners for offshore final disposal sites. To overcome the challenges, this study proposed a novel isolation particle layer for offshore final disposal sites. The isolation particle was composed by salt-resistant bentonite coating material and cement core material (D10 was 10 mm in core diameter and 2 mm in coating thickness; D20 was 20 mm and 4 mm). Upon immersion in artificial seawater, the isolation particles underwent expansion, leading to the formation of the novel isolation particle layers with low hydraulic conductivity less than 1 × 10-7 cm/s and adsorption of heavy metals in bentonite interlayers. Large column tests showed that both D10 and D20 isolation particle layers exhibited remarkable swelling capacity and low hydraulic conductivity (4.3 × 10-9 cm/s and 2.6 × 10-8 cm/s) under 3 m seawater pressure. During one year of observation, water tank test demonstrated that both isolation particle layers displayed remarkable stability and low hydraulic conductivity of 2.73 × 10-10 cm/s and 8.36 × 10-10 cm/s with load. The maximum adsorption capacities of salt-resistant bentonite were 123.55 mg/g for Pb2+, 60.29 mg/g for Cd2+ and 54.22 mg/g for Cu2+. Both isolation particle layers exhibited a high removal rate of over 95 % for heavy metals in water tank tests. The large-scale laboratory tests indicated the significant potential of the novel isolation particle layer for offshore final disposal sites. Subsequently, a testing ocean site will be selected to further investigate its practical engineering performance. [ABSTRACT FROM AUTHOR]

Background: Maxillary molar endodontic treatments require the right post and core system. This study tested cast metal, glass fiber with composite resin, carbon fiber with composite resin, and zirconia post and core materials. Materials and Methods: Sixty removed human maxillary teeth were randomly divided into four post and core material groups (n = 15 per group). The teeth acquired their post and core system after normal endodontic treatment. Fracture resistance, cyclic fatigue resistance, and microleakage analyses were statistically assessed. Results: The zirconia post and core material had the highest fracture resistance (mean: 900 N), followed by carbon fiber with composite resin, cast metal, and glass fiber with composite resin. Zirconia had the highest mean cycles to failure (120,000), followed by carbon fiber with composite resin (100,000), cast metal (110,000), and glass fiber with composite resin (90,000). Zirconia had the lowest mean microleakage score (1.8), and glass fiber with composite resin, the highest (3.0). Conclusion: The zirconia post and core material outperformed the others in fracture resistance, cyclic fatigue resistance, and sealing. The cast metal has better fracture and cycle fatigue resistance than glass fiber with composite resin. These findings help doctors choose maxillary molar endodontic post and core materials. [ABSTRACT FROM AUTHOR]

In order to achieve low refractive index detection in biomedical and material chemistry, a D-type microstructured optical fiber (MOF) sensor based on surface plasmon resonance (SPR) is proposed in this paper. The sensor uses gold nanofilm as sensing material between the core of the fiber and the plasma on the surface, and is coated at the open ring. Parametric analysis of the open-ring diameter, air hole diameter, and thickness of the gold nanofilm of the sensor was carried out by finite element method. The simulation results show that the sensor has a wavelength sensitivity of up to 10,900 nm/RIU, the refractive index range of 1.20–1.34, optimal resolution of 9.17 × 10−6 RIU, and a decent figure of merit (FOM) is 46.2 RIU−1. The proposed MOF-SPR sensor has high wavelength sensitivity and low resolution in a similar detection range compared to existing studies. The sensor is capable of detecting not only low refractive index substances, such as liquid medical oxygen with a refractive index of 1.22 and sevoflurane with a refractive index of 1.27, but also conventional refractive index substances such as water contamination with a refractive index near 1.33, providing a wide detection range. Therefore, the sensor is competitive in the detection of some low refractive index material detection fields. [ABSTRACT FROM AUTHOR]

The core-shell structure conduit with conductive, antibacterial, and highly piezoelectric properties was designed and fabricated by a multi-step process. First, the shell structure was fabricated by rolling the co-electrospun mats of polycaprolactone/polyvinylidene fluoride and gelatin incorporated with polyaniline/graphene (PAG) nanocomposites. Then, the fabricated mats were filled with gelatin/chitosan hydrogels containing PAG and zinc oxide nanoparticles. Characterization of the intermediate materials and the final conduit revealed high electrical conductivity and remarkable output voltage for shell and core materials. MTT assay and antibacterial tests confirmed bioactivity and antibacterial properties of shells and cores. The results confirmed appropriateness of the conduit for nerve regeneration applications. [ABSTRACT FROM AUTHOR]