Search Results (888)

This study was conducted to investigate and identify correlations among sensory and comprehensive consumer test results with rheological, textural, and tribological properties of milk chocolate in response to varying levels of particle size and emulsifier. To simulate realistic oral conditions, artificial saliva was incorporated into instrumental analyses. Rheological analysis revealed that increasing particle size and emulsifier concentration significantly reduced plastic viscosity, while emulsifier concentration alone increased yield stress due to structural reorganization within the fat phase. Tribological measurements demonstrated that larger particles increased friction in boundary and mixed lubrication regimes, whereas emulsifiers reduced friction in these regimes by enhancing fluid film formation. Under elastohydrodynamic conditions and with artificial saliva, friction was more influenced by the interaction between particle size and emulsifier level. Textural analysis showed that both parameters significantly influenced hardness, with saliva further softening the samples, especially those with higher emulsifier levels. Sensory evaluations indicated that emulsifiers enhanced flavor release and mouthfeel attributes, while smaller particles contributed to smoother texture and more balanced flavor perception. Consumer acceptance tests confirmed that samples with smaller particles and higher emulsifier levels received the highest scores in overall liking, taste, and texture. Instrumental parameters strongly correlated with key sensory attributes, with yield stress showing the highest positive associations with creaminess, smoothness, fat/milk flavor, and liking, while higher viscosity and friction were negatively linked to flavor release and mouthfeel. Instrumental hardness negatively correlated with cacao intensity and astringency, while saliva-induced softening was positively associated with sweetness and liking, highlighting the role of dynamic oral softening. Full article

The impact modification of polyamide 6 (PA6) using maleic anhydride-grafted ethylene/1-octene copolymers (EOR-g-MAH) involves a trade-off between improved compatibilization, grafting-induced changes in modifier molecular weight $MW$, and melt processability. In this study, EOR modifiers with comparable initial $MW$ but different octene contents ($c_{\mathrm{o}\mathrm{c}\mathrm{t}}$ = 13, 15, and 16 mol%) were grafted to two MAH levels ($c_{\mathrm{M}\mathrm{A}\mathrm{H}}$ = 0.5 and 1.0 wt%) and incorporated into PA6 at a fixed composition. The system was designed to maintain a comparable microstructure, enabling the isolation of grafting-induced changes in modifier properties from microstructural effects. $MW$ distributions were analyzed by gel permeation chromatography, and the impact behavior was evaluated over a wide temperature range, using an instrumented Charpy impact test. The results reveal a strong, interrelated, $c_{\mathrm{o}\mathrm{c}\mathrm{t}}$- and $c_{\mathrm{M}\mathrm{A}\mathrm{H}}$-dependent competition between β-scission and cross-linking during grafting, which governs the modifier’s $MW$ distribution and particle strength. Higher $c_{\mathrm{o}\mathrm{c}\mathrm{t}}$ (15 and 16 mol%) enhances the impact performance up to ≈0 °C, well above the brittle–ductile transition temperature (BDTT), through increased elastic and plastic deformation capability of the modifiers. At elevated temperatures, however, successive melting of the modifiers leads to a loss of particle strength. At high $c_{\mathrm{o}\mathrm{c}\mathrm{t}}$ and $c_{\mathrm{M}\mathrm{A}\mathrm{H}}$ = 1.0 wt%, susceptibility to β-scission increases, leading to $MW$ reduction that, for $c_{\mathrm{o}\mathrm{c}\mathrm{t}}$ = 16 mol%, is detrimental to impact performance, particularly above the BDTT. This effect is further amplified by reduced ductility due to stronger polar intermolecular interactions at high grafting levels. A moderate $c_{\mathrm{M}\mathrm{A}\mathrm{H}}$ = 0.5 wt% and $c_{\mathrm{o}\mathrm{c}\mathrm{t}}$ = 15 mol% provides an optimal compromise between strength and ductility, delivering high impact strength across a broad temperature range. At this $c_{\mathrm{M}\mathrm{A}\mathrm{H}}$ level, the number of PA6 chains covalently anchored to the modifier particles is moderate, resulting in lower compound viscosity and supporting favorable melt processability. Full article

The impact modification of polyamide 6 (PA6) using maleic anhydride grafted ethylene/1-octene copolymers (EOR-g-MAH) is well-established, yet the isolated influence of intrinsic modifier parameters—specifically octene content $c_{\mathrm{o}\mathrm{c}\mathrm{t}}$ and molecular weight $MW$—remains insufficiently understood due to confounding microstructural effects. This study presents a systematic approach to decouple these variables by maintaining constant grafting degree, modifier content, and compound morphology. A series of PA6/EOR-g-MAH compounds was prepared with controlled variations in $c_{\mathrm{o}\mathrm{c}\mathrm{t}}$ (8–15 mol%) and $MW$ (34–42 kg/mol). Instrumented Charpy impact testing across a temperature range from −40 °C to +23 °C enabled quantification of crack initiation and propagation energies ($E_{\mathrm{i}\mathrm{n}\mathrm{i}\mathrm{t}}$ and $E_{\mathrm{p}\mathrm{r}\mathrm{o}\mathrm{p}}$), providing mechanistic insight into the brittle–ductile transition. Complementary thermal, rheological, and tensile analyses of the modifiers revealed how $c_{\mathrm{o}\mathrm{c}\mathrm{t}}$ governs cavitation behavior and low-temperature toughness, while $MW$ in particular influences particle integrity and energy dissipation at elevated temperatures. The results demonstrate that targeted adjustment of $c_{\mathrm{o}\mathrm{c}\mathrm{t}}$ and $MW$ allows for the precise tuning of brittle–ductile transition temperature (BDTT) and impact resistance. The compound containing a high-$MW$ modifier with intermediate $c_{\mathrm{o}\mathrm{c}\mathrm{t}}$ (13 mol%) exhibited the most favorable balance of toughness and strength retention at elevated temperatures. These findings offer design principles for engineering thermoplastics with enhanced performance across broad service conditions. Full article

Excessive sodium consumption is a global public health problem that demands technological innovations in processed foods. This study aimed to reduce the sodium content in extruded corn snacks while maintaining perceived saltiness by substituting common salt with compound microparticles (70% NaCl, 30% starch). Two drying methods were evaluated: spray drying and conventional oven drying. The snacks were subjected to physicochemical, instrumental (texture and colour), density, porosity, microstructural, and sensory analyses (intensity scale, n = 104). The results demonstrated that the particles obtained by spray drying allowed a 28% reduction in the final sodium content without statistically differing in saltiness perception compared to the control. In contrast, the oven treatment reduced saltiness perception compared to the standard. Images obtained by scanning electron microscopy, along with porosity measurements, demonstrated a significant increase in porosity in the spray-dried sample. This allows rapid dissolution of the salt in the mouth, maintaining a salty taste even with reduced sodium content. It was concluded that the use of salt–starch microparticles via spray drying was a viable strategy for producing snacks with reduced sodium content without compromising sensory quality. Full article

Microplastics (MPs) and emerging contaminants (ECs) are increasingly prevalent in environments due to their persistence, toxicity, and resilience against standard wastewater treatment methods. This review presents a comprehensive analysis of contemporary and advanced membrane-based techniques, highlighting their removal efficacy, recovery potential, and fundamental mechanisms such as size exclusion, adsorption, electrostatic interactions, and biodegradation. This review emphasizes the physicochemical properties of MPs, including particle size, shape, polymer type, and hydrophobicity, and their significant impact on membrane performance and fouling behavior. Key findings reveal that membrane fouling is a primary constraint affecting operational efficiency. This study identifies the types of fouling standard, total, intermediate, and cake formation that contribute to flux deterioration and necessitate increased energy expenditures during prolonged operation. Additionally, this research highlights the detrimental effects of mechanical abrasion and scaling on membrane integrity and lifespan. Future prospects for membrane technology are explored, positioning it as a leading solution for sustainable wastewater treatment. Essential directives include the development of intelligent membranes responsive to environmental stimuli, AI-driven monitoring systems, and modular and decentralized treatment units. Moreover, the implementation of circular economy principles is discussed, emphasizing concurrent treatment and resource recovery, such as nutrients, biogas, and clean water. The regulatory and legislative implications of membrane-based treatment are also addressed, underscoring the importance of standardization, performance evaluation, and sustainability. Ultimately, this analysis positions membrane technologies as pivotal instruments in the advancement of intelligent, energy-efficient, and regenerative wastewater management systems. Full article

To effectively prevent and control coal spontaneous combustion, a novel heat-sensitive hydrogel for mine fire prevention and extinguishment was developed using hydroxypropyl methylcellulose (HPMC) and the organic flame-retardant, sodium alginate (SA). The hydrogel was prepared through single-factor variable control and material compounding. First, the optimal formulation of the hydrogel was determined using analytical instruments and techniques, including a viscometer, vacuum drying oven, and the inverted test tube method. Subsequently, its microstructural characteristics were examined using scanning electron microscopy (SEM) and infrared spectroscopy (FTIR). Finally, a fire suppression test platform was established to perform comparative experiments, verifying the hydrogel’s fire prevention, extinguishing, and cooling performance. Experimental results demonstrated that the optimal hydrogel formulation consists of 2.5 wt% HPMC and 0.3 wt% SA. At this ratio, the hydrogel exhibits excellent fluidity and water retention, ensuring prolonged coverage and wetting of coal surfaces. The gel undergoes a sol–gel phase transition at 58 °C, enabling it to fill voids, bind and reinforce coal particles, and reduce exposed surface area. After drying, the hydrogel forms a uniformly smooth surface capable of both coating the coal body and encapsulating individual coal particles. Following the hydrogel treatment, the coal sample retains its original functional groups, indicating that no chemical reactions occur during mixing. Compared with traditional inhibitors, the hydrogel demonstrates superior fire suppression performance, more effectively covering and encapsulating burning coal. It rapidly reduces the temperature to 28 °C by the cooling effect of water evaporation from the hydrogel, and it maintains thermal stability, achieving outstanding fire-extinguishing efficiency. Full article

Stokes drift is the net displacement of ocean surface water particles caused by nonlinear surface waves. Its estimation typically relies on sea surface wave spectra, and truncation of the high-frequency spectral tail can significantly affect accuracy. This study uses directional wave spectrum data from the SWIM instrument onboard CFOSAT. By introducing a wind-speed-dependent parameterization scheme for the transition wavenumber (k_n) between the equilibrium and saturation ranges, as well as a cutoff wavenumber (k_m), we constructed a model to supplement the high-frequency tail of the wave spectrum combined with mask filtering to optimize spectrum reconstruction. The Stokes drift calculated with this model shows a better correlation (R = 0.699) with buoy observations than the widely used ERA5 reanalysis (R = 0.613). Analysis reveals pronounced regional differences in the contribution of high-frequency waves to surface Stokes drift, exceeding 80% in equatorial low-wind regions while dropping below 10% in the high-wind Southern Ocean due to enhanced breaking dissipation. The global Stokes drift distribution exhibits clear hemispheric asymmetry and seasonal evolution, with peak values (>0.12 m/s) in the Antarctic Circumpolar Current region. The proposed method provides a reliable, observation-based approach for improving global Stokes drift estimation, with direct implications for modelling ocean transport, Langmuir turbulence, and air–sea interactions. Full article

With the advancements in instrumentation, image processing algorithms, and computational capabilities, single-particle cryo-electron microscopy (cryo-EM) has achieved atomic resolution in determining the 3D structures of viruses. The virus structures play a crucial role in studying their biological function and advancing the development of antiviral vaccines and treatments. Despite the effectiveness of artificial intelligence (AI) in general image processing, its development for identifying and extracting virus particles from cryo-EM micrographs has been hindered by the lack of manually labeled high-quality datasets. To fill the gap, we introduce CryoVirusDB, a labeled dataset containing the coordinates of expert-picked virus particles in cryo-EM micrographs. CryoVirusDB comprises 9941 micrographs from nine datasets representing seven distinct non-enveloped viruses exhibiting icosahedral or pseudo-icosahedral symmetry, along with coordinates of 339,398 labeled virus particles. It can be used to train and test AI and machine learning (e.g., deep learning) methods to accurately identify virus particles in cryo-EM micrographs for building atomic 3D structural models for viruses. Full article

The Advanced Particle–astrophysics Telescope (APT) is a mission concept for a future space-based MeV-TeV observatory, designed to combine a Compton and $e^{+}{e}^{-}$ pair telescope, aiming to improve the sensitivity of the instruments to $\gamma$ rays in the MeV-GeV range by at least one order of magnitude. To validate and study the technologies that will be employed on the observatory, a small-scale prototype, the Antarctic Demonstrator for APT (ADAPT), is currently being developed to fly on a balloon in Antarctica during the local 2026–2027 flight season. Among its subdetectors there is an Imaging CsI calorimeter (ICC), consisting of 4 layers of CsI(Na) crystals with crossed WLS fibers, coupled to Silicon Photomultipliers (SiPMs). A key element of the design is the multichannel front-end electronics, based on the SMART (SiPM Multichannel ASIC for high-Resolution Cherenkov Telescopes) ASIC, which combines compactness, cost-effectiveness, and a high level of integration. This work reports the results of quality-control tests performed on the custom readout boards for the ICC, and provides an overview of the present status of the mission. Full article

COMCUBE-S (Compton Telescope CubeSat Swarm) is a proposed mission aimed at understanding the radiation mechanisms of ultra-relativistic jets from Gamma-Ray Bursts (GRBs). It consists of a swarm of 16U CubeSats carrying a state-of-the-art Compton polarimeter and a bismuth germanium oxide (BGO) spectrometer to perform timing, spectroscopic and polarimetric measurements of the prompt emission from GRBs. The mission is currently in a feasibility study phase (Phase A) with the European Space Agency to prepare an in-orbit demonstration. Here, we present the simulation work used to optimise the design and operational concept of the microsatellite constellation, as well as estimate the mission performance in terms of GRB detection rate and polarimetry. We used the MEGAlib software to simulate the response function of the gamma-ray instruments, together with a detailed model for the background particle and radiation fluxes in low-Earth orbit. We also developed a synthetic GRB population model to best estimate the detection rate. These simulations show that COMCUBE-S will detect about 2 GRBs per day, which is significantly higher than that of all past and current GRB missions. Furthermore, simulated performance for linear polarisation measurements shows that COMCUBE-S will be able to uniquely distinguish between competing models of the GRB prompt emission, thereby shedding new light on some of the most fundamental aspects of GRB physics. Full article

Magnetorheological elastomers (MREs) have attracted considerable attention in high-precision sensing and intelligent control due to their responsive sensitivity. The magnetostrictive properties of MREs excited by magneto-mechanical coupling at the mesoscopic scale show broad application potential but have not yet been fully elucidated. In this study, the magnetostrictive properties were investigated at the mesoscopic scale through theoretical modeling, numerical simulation and experimental research. A correction factor was introduced to address the limitations of conventional magnetic dipole theory under near-field conditions, thereby providing a rational theoretical explanation of magnetostrictive behavior. Visualization analysis was performed using the finite element method (FEM). Subsequently, MREs were prepared under various solidified magnetic fields, and their performance was validated through scanning electron microscopy (SEM) and a laser displacement sensor. The results demonstrated that magnetostriction is determined by the relative angle between the particle chain and the magnetic field direction. The linearity of the particle chain was found to be positively correlated with magnetostriction. The maximum theoretical and experimental magnetostrictive elongations reached 0.9% and 0.565%, respectively, while the maximum theoretical and experimental magnetostrictive compression reached 2.77% and 1.81%, respectively. This work provides significant scientific insights into the magneto-mechanical energy conversion mechanism and contributes to the development of magnetostrictive instruments. Full article

An ongoing challenge in pelagic oceanography and limnology is to quantify and understand the distribution of suspended particles and particle aggregates with sufficient temporal and spatial fidelity to understand their dynamics. These particles include biotic (mesoplankton, organic fragments, fecal pellets, etc.) and abiotic (dusts, precipitates, sediments and flocks, anthropogenic materials, etc.) matter and their aggregates (i.e., marine snow), which form a large part of the total particulate matter > 200 μm in size in the ocean. The transport of organic material from surface waters to the deep-sea floor is of particular interest, as it is recognized as a key factor controlling the global carbon cycle and hence, a critical process influencing the sequestration of carbon dioxide from the atmosphere. Here we describe the development of an oceanographic instrument, the Pelagic Laser Tomographer (PLT), that uses high-resolution optical technology, coupled with post-processing analysis, to scan the 3D content of the water column to detect and quantify 3D distributions of small particles. Existing optical instruments typically trade sampling volume for spatial resolution or require large, complex platforms. The PLT addresses this gap by combining high-resolution laser-sheet imaging with large effective sampling volumes in a compact, deployable system. The PLT can generate spatial distributions of small particles (~100 µm and larger) across large water volumes (order 100–1000 m³) during a typical deployment, and allow measurements of particle patchiness over spatial scales to less than 1 mm. The instrument’s small size (6 kg), high resolution (~100 µm in each 3000 cm² tomographic image slice), and analysis software provide a tool for pelagic studies that have typically been limited by high cost, data storage, resolution, and mechanical constraints, all usually necessitating bulky instrumentation and infrequent deployment, typically requiring a large research vessel. Full article

This study presents a systematic investigation of laser surface hardening of 9CrSi tool steel with the aim of establishing the relationships between processing parameters, microstructural evolution, and resulting mechanical and tribological properties under the applied laser conditions. The influence of laser power, modulation frequency, and scanning speed on the hardened layer depth, microstructure, and surface properties was analyzed. Laser treatment produced a martensitic surface layer with varying fractions of retained austenite, while the transition zone consisted of martensite, granular pearlite, and carbide particles. X-ray diffraction identified the presence of α′-Fe, γ-Fe, and Fe₃C phases, with peak broadening associated with increased lattice microstrain induced by rapid self-quenching. The surface microhardness increased from approximately 220 HV_0.1 in the untreated state to 950–1000 HV_0.1 after laser hardening, with hardened layer thicknesses ranging from about 500 to 750 µm depending on the processing regime. Instrumented indentation showed higher elastic modulus values for all hardened conditions. Tribological tests under dry sliding conditions revealed reduced coefficients of friction and more than an order-of-magnitude decrease in wear rate compared with untreated steel. The results provide a parameter–microstructure–performance map for laser-hardened 9CrSi steel, demonstrating how variations in laser processing conditions affect hardened layer characteristics and functional performance. Full article

The photovoltaic (PV) bands on the mid-wave and long-wave infrared (MWIR and LWIR) cold focal plane assemblies of Terra and Aqua MODIS have suffered from gradually increasing electronic crosstalk contamination as both instruments have continued to operate in their extended missions, respectively. This contamination has considerable impact, particularly for the PV LWIR bands, which includes image striping and radiometric bias in the Level-1B (L1B)-calibrated radiance products as well as higher level (and mostly atmospheric but also land and oceanic) products (e.g., cloud phase particle, cloud mask, land and sea surface temperatures). The crosstalk was characterized early in the mission, and test corrections were developed then. Ultimately, the groundwork for a robust electronic crosstalk correction algorithm was developed in 2016 and implemented in MODIS Collection 6.1 (C6.1) back in 2017 for the Terra MODIS PV LWIR bands. It was later introduced in Aqua MODIS C6.1 for the same group of bands in April 2022. Additional improvements were made in MODIS Collection 7 (C7) to better characterize the electronic crosstalk in the PV LWIR bands, and the electronic crosstalk correction algorithm was also extended to select detectors in the MODIS MWIR bands. This work will describe the electronic crosstalk correction algorithm and its application on the MODIS L1B product, the differences in application between C6.1 and C7, as well as additional improvements made to enhance the contamination correction and improve image quality for the Aqua MODIS PV LWIR bands. The electronic crosstalk correction coefficient time series for the MODIS PV bands will be discussed, and some cases will be presented to illustrate how image quality improves on the L1B and Level 2 products after the correction is applied. Lastly, experiences gained regarding the PV bands electronic crosstalk and the strategy used to correct it will be discussed to provide future data users and scientists with an insight as to how to improve on the legacy record that the Terra and Aqua MODIS sensors will leave behind after both spacecrafts are decommissioned. Full article

The accurate simulation of sub-GeV particle detectors is essential for interpreting experimental data and optimizing detector design. This work identifies and addresses several critical aspects in modeling such detectors, taking as a case study the High-Energy Particle Detector (HEPD-02), a space-borne instrument developed within the CSES-02 mission to measure electrons in the ∼3–100 MeV range, protons and light nuclei in the ∼30–200 MeV/n. The HEPD-02 instrument consists of a silicon tracker, plastic and LYSO scintillator calorimeters, and anticoincidence systems, making it a representative example of a complex low-energy particle detector operating in Low Earth Orbit. Key challenges arise from replicating intricate detector geometries derived from CAD models, selecting appropriate hadronic physics lists for low-energy interactions, and accurately describing the detector response—particularly quenching effects in scintillators and digitization in solid-state tracking planes. Particular attention is given to three critical aspects: the precise CAD-level geometry implementation, the impact of hadronic physics models on the detector response, and the parameterization of scintillation quenching. In this study, we present original solutions to these challenges and provide data–MC comparisons using data from HEPD-02 beam tests. Full article