Cube Surface Research Articles

Changes in freezing parameters and temperature distribution of beef induced by AC electric field: Alleviation on freezing damage and myowater loss

In this study, a specialized experimental device integrating infrared thermal imaging, real-visual photography, and a time-temperature data collector was designed to investigate the effects of alternating electric field (AEF) assisted freezing on the temperature histories and freezing parameters in different layers of beef as well as the freezing damage and myowater loss. The findings revealed distinct differences in the freezing curves (e.g., slope) and parameters (e.g., Tnuc, TF, tptand Fmiz) between the surface, middle, and inner layers of beef cubes under both AEF and traditional freezing conditions. AEF treatment regulated the freezing curves and key parameters of middle and surface layers, influencing ice crystallization. The equivalent ice areas for the surface, middle, and inner samples under AEF treatment were 8.16, 14.40, and 20.56%, respectively, significantly lower than those in traditional freezing (15.87, 24.60, and 28.8%). Compared to traditional freezing, AEF-assisted freezing decreased myofibrillar fragmentation index (MFI) of beef muscle, preserving its texture integrity. AEF treatment inhibited water migration and reduced water-holding capacity (WHC) loss. In conclusion, AEF-assisted freezing changed ice formation characteristics and alleviated freezing damage by regulating the freezing curve traits and parameters.

Z-Scheme Heterojunction of Hierarchical Cu2S/CdIn2S4 Hollow Cubes to Boost Photoelectrochemical Performance.

The exaltation of light-harvesting efficiency and the inhibition of fast charge recombination are pivotal to the improvement of photoelectrochemical (PEC) performance. Herein, a direct Z-scheme heterojunction is designed of Cu2S/CdIn2S4 by in situ growth of CdIn2S4 nanosheets on the surface of hollow CuS cubes and then annealing at 400°C. The constructed Z-scheme heterojunction is demonstrated with electron paramagnetic resonance and redox couple (p-nitrophenol/p-aminophenol) measurements. Under illumination, it shows the photocurrent 6 times larger than that of hollow Cu2S cubes, and affords outstanding PEC performance over the known Cu2S and CdIn2S4-based photocatalysts. X-ray photoelectron spectroscopy and density functional theory results demonstrate a strong internal electric field formed in Cu2S/CdIn2S4 Z-scheme heterojunction, which accelerates the Z-scheme charge migration, thereby promoting electron-hole separation and enhancing their utilization efficiency. Moreover, the hollow structure of Cu2S is conducive to shortening the charge transport distance and improving light-harvesting capability. In proof-of-concept PEC application, a PEC detection method for miRNA-141 based on the sensitivity of benzo-4-chloro-hexadienone to light absorption on Cu2S/CdIn2S4 modified electrode is developed with good selectivity and a limit of detection of 32 aM. This work provides a simple approach for designing photoactive materials with highly efficient PEC performance.

Generation of biosurfactants by P. aeruginosa gi |KP163922| on waste engine oil in a free and immobilized cells system

AbstractThis study investigated biosurfactant production by the bacterial strain of P. aeruginosa gi |KP 163922| for a free and immobilized cells system using waste engine oil (WEO) as a substrate. The polyurethane foam (PUF) cubes (1 cm × 1 cm × 1 cm) were used as carriers for the immobilization. The batch experiments were performed in Erlenmeyer flasks and monitored at every 24‐h interval for both cell systems. The microbial population was counted using the plate count method, and the hydrocarbon degradation percentage was calculated to evaluate the bacterial activity. Surface tension was measured at regular intervals to ensure the presence of biosurfactants. The maximum reduction was 37 and 35 mN/m in a free and immobilized cells system. Immobilization of cells using PUF was found to be efficient in supporting bacterial growth, and after 48 h of incubation, the growth was 2.5 (±0.58) × 1011 CFU/mL. The chemical characterization using Fourier transform infrared (FTIR) spectroscopy confirmed the obtained product as rhamnolipid. Crude biosurfactant yield was found to be maximum in the case of the immobilized system, which was approximately 18 g/L. Scanning electron micrographs (SEM) of the used PUF cubes showed the strong adherence of biofilm to the cube surface and the potential of its reuse in multiple cycles. Gas chromatography–mass spectrometry (GC–MS) analysis confirms that the immobilized strain of P. aeruginosa exhibited superior biodegradation capabilities compared to free cells. Specifically, it was capable of reducing the concentration of polyaromatic hydrocarbons and converting more significant aliphatic compounds into metabolic byproducts such as alkanes, alkenes, cycloalkanes, and carbonyl groups.

Enhancing reading and writing instruction in inclusive environments: A meaningful and collaborative approach

n inclusive educational settings, educators often face challenges in effectively allocating time and providing appropriate support for students with disabilities. This research aims to address these challenges by proposing a complementary method that integrates seamlessly with conventional teaching approaches, benefiting both teachers and students in the realm of reading and writing education. The primary objective is to develop a comprehensive design that supports reading and writing instruction within an inclusive environment. The proposed approach adopts a holistic perspective by incorporating classroom walls, cubes, and diverse notebooks into the learning environment. At its core, this approach revolves around two fundamental elements: the utilization of meaningful reading and writing methods and the emphasis on collaborative learning. The study is substantiated by three tiny-research initiatives, providing practical insights into the implementation of inclusive classrooms aligned with the proposed recommendations. This research introduces a holistic design, and through various investigations conducted during its development, addresses key aspects such as the design specifications for the cubes, the functionality of notebooks facilitating interaction between walls and cube surfaces, and strategies for facilitating unhindered reading and writing instruction. The findings contribute to answering crucial questions on considerations for creating an inclusive and effective learning environment for primary reading and writing instruction.

Revisiting the surface-mounted cube: An updated perspective of the near wake and near-wall flow field

The flow around a surface-mounted cube has been investigated for decades, yet the fundamentals of the mean flow have not been updated to reflect the latest advances regarding the flow around surface-mounted finite-height square prisms in general. One of the main gaps is the flow field very near the cube walls, especially the sides, and its relationship to the near wake. To investigate these features, large-eddy simulations of the flow around a surface-mounted cube were carried out at a Reynolds number Re =1×104. Two boundary layers were considered: a thin and laminar boundary layer and a thick and turbulent one, to provide an overview of the flow around the cube for contrasting boundary layers. The major flow structures in the mean wake were the horseshoe vortex, the arch vortex and the dipole structures, with other regions of vorticity also present. The time-averaged flow fields presented similar flow features for both boundary layers, but the thicker and turbulent one caused the horseshoe vortex to be located closer to the cube, the wake to become narrower and shorter, the coherent structures and downwash to weaken, the pressure to decrease around the sides and top of the cube, the drag force coefficient to decrease, the normal force coefficient to increase, and the trailing edge vortices to weaken. Intermittent flow reattachment on the top and side faces of the cube, as well as corner vortices, were found for both boundary layers, while the side and free end vortices were found exclusively with the thicker boundary layer, yielding a headband vortex. The three-dimensional flow structures and features were related to the near-wall flow field on the cube and ground plane surfaces, giving a complete and updated description of the mean flow characteristics.

Numerical calculation of the turbulent flow past a surface mounted cube with assimilation of PIV data

The application of Data Assimilation (DA) methods in Computational Fluid Dynamics (CFD) problems is a concept actively being explored to couple CFD with Experimental Fluid Dynamics data. Here, Particle Image Velocimetry (PIV) data are assimilated in an OpenFOAM based CFD solver to calculate the velocity and pressure fields of the turbulent flow past a surface mounted cube inside an atmospheric boundary layer for three planes belonging to the symmetry plane of the flow. At first, the SIMPLE algorithm is used to correct both pressure and velocity fields, with the PIV data used to formulate the initial and boundary conditions. The Reynolds stresses are calculated directly from the PIV data instead of using a turbulence model. Next, we use two implementations of the nudging method and two formulations of the Kalman Filter in order to assimilate the PIV data into the iterative SIMPLE procedure. A grid independence study is performed, and the performance of the different methods is assessed. The CFD predicted pressure field is in good agreement with pressure measurements on the cube surface. The results also show that the SIMPLE based correction step already leads to a significant reduction of both the mean and the variance of the continuity errors as well as the difference between the original PIV data and the resulting velocity fields. The application of the DA methods, particularly the KF, leads to minor further improvement of the results but does improve convergence of the CFD solver.

A Detailed Insight into the Effects of Morphologies of Cerium Oxide on Fenton-like Reactions for Different Applications.

As an exceptional Fenton-like reagent, cerium oxide (CeO2 ) finds applications in biomedical science and organic pollutants treatment. The Fenton-like reaction catalyzed by CeO2 typically encompasses two distinct processes: one resembling the classical Fenton reaction, wherein cerium (Ce3+ ) triggers the decomposition of hydrogen peroxide (H2 O2 ) to yield reactive oxygen species (ROS), and the other involves the complexation of H2 O2 on the Ce3+ surface, leading to the formation of peroxides. However, the influence of diverse CeO2 morphologies on these two reaction pathways has not been comprehensively explored. In this study, CeO2 exhibiting three typical morphologies, rods, cubes, and spheres, were prepared. The generation of ROS and peroxides was evaluated using the 3,3,5,5-tetramethylbenzidine (TMB) oxidation reaction and the reduction current of H2 O2 , respectively. Moreover, the impacts of pH variations and CeO2 /H2 O2 concentrations on the production and conversion of these two reaction products were investigated. To corroborate the distinctions between the resultant products and their applicability, apoptosis assays and acid orange 7 (AO7) degradation analyses were performed. Notably, CeO2 rods exhibited the highest proportion of Ce3+ , predominantly engaging in complexation with H2 O2 to foster peroxide formation, thereby facilitating the robust degradation of AO7. However, the generated peroxides appeared to occupy Ce3+ sites, thereby impeding the H2 O2 decomposition process. Conversely, Ce3+ species on the surface of CeO2 cubes were primarily involved in H2 O2 decomposition, leading to heightened ROS production, and thus showcasing substantial potential for damaging A549 tumor cells. It is worth noting that the ability of these Ce3+ species to form peroxides through complexation with H2 O2 was comparatively reduced. In summation, this study sheds light on the intricate interplay between distinct CeO2 morphologies and their divergent impacts on Fenton-like reactions. These findings expand our comprehension of the influences on its reactivity of CeO2 morphologies and open new insights for applications in diverse domains, from organic dye degradation to tumor therapy.

Optimization of WLS fiber readout for the HERD calorimeter

A novel 3-D calorimeter, composed of about 7500 LYSO cubes, is the key and crucial detector of the High Energy cosmic-Radiation Detection (HERD) facility to be installed onboard the China Space Station. Energy deposition from cosmic ray in each LYSO cube is translated by multiple wavelength shifting (WLS) fibers for multi-range data acquisition and real-time triggering.In this study, various methods of surface finish and encapsulation of the LYSO cube were investigated to optimize the amplitude from the WLS fiber end with the aim of improving the signal-to-noise ratio of Intensified scientific CMOS (IsCMOS) collection. The LYSO cube with five rough surfaces and a specular reflector achieves the maximum amplitude at the low-range fiber end, which is increased by roughly 44% compared to the polished cube with PTFE wrapping.The non-uniformity of amplitude at different positions on the LYSO cube surface was measured by X-ray and the positional correlation factor was derived for the entire cube. A simulation based on HERD CALO was conducted, which revealed that both the LYSO cube with five rough surfaces and the cube with rough bottom face exhibit superior energy resolution for electrons compared to the other two configurations.

Preservation of Wastewater Sedimentation Tanks by Using Proposed Types of Coatings

In Baghdad, Al- Rustamiya wastewater treatment plant was exposed to high and continuous drainage of sewage water, leading to weak in concrete parts of wastewater treatment plant. Protection of sedimentation tanks may be achieved by applying suitable coatings which resist the biological reaction and chemical effects of wastewater. Three types of coatings were prepared by using Siloxane polymer (SX5000WB) mixed with different amounts of micro titanium dioxide (TiO2). Concrete cubes were covered with these coatings and partially immersed for 28 days in basins contain wastewater brought from Al- Rustamiya primary and secondary sedimentation tanks. Swabs from the cubes were also taken to monitor bacterial growth on cube's surfaces after applying different types of coatings. To determine the effects of coatings on concrete cubes strength, compressive strength was measured after 28 days of partially immersing in wastewater. According to the study's findings, coated concrete with 250 mg of micro TiO2 per litre of the polymer is a suitable method of protection. At this concentration of TiO2, bacterial growth was almost zero at concrete immersed in wastewater taken from primary and secondary sedimentation tanks, no obvious relationship was found between the type of coating and reduction of chloride and sulphate effect. Concrete compressive strength was increased by the increasing of coatings concentrations providing a thin film that may contribute in concrete protection.

Interfacial oxygen vacancy modulated Ag3PO4 @MoS2 Z-scheme system for efficient photocatalytic hydrogen recovery from antibiotic wastewater

Z-scheme Ag3PO4 @MoS2 photocatalyst was constructed by decorating MoS2 nanosheets on Ag3PO4 cubes for recovering hydrogen energy from antibiotic wastewater. Abundant oxygen vacancies (Vo) distributed along with Ag3PO4 cube surface are responsible for MoS2 lattice distortion by enabling 2 H phase MoS2 around Vo partially transform in 1 T phase. Free radicals trapping and theoretical calculation approve that Vo act as intermediate medium of charge transferring in Z-scheme Ag3PO4 @MoS2 system. On the strength of Vo and mixed phase of MoS2 providing more exposed active sites, superior conductivity and excellent stability, photocatalytic hydrogen recovery over Ag3PO4 @MoS2 is high up to 54.01 µmol·g−1·h−1 from norfloxacin wastewater (degradation efficiency: 88.36%). It is found that bandgap matching between antibiotics molecule and Ag3PO4 @MoS2 accounts for hydrogen recovery kinetics. H protons could be donated in the process of decyclopropylaton, dihydroxylation and demethylation for antibiotic degradation. This work presents new lines for seeking greater sustainability by managing antibiotics wastewater resource.

Research of cooling performance in combined jet flow channels using different nanofluids

In this work, heat transfer from the cube and circular hollow-shaped copper plate surfaces with a constant heat flux of 1000 W/m2 was numerically investigated by using a combination of the cross-flow-impinging jet. Numerical research was performed by solving the energy and Navier-Stokes equations as three-dimensional and steady, using the Ansys-Fluent computer program with the k-ε turbulence model. In order to direct the combined jet flow in the channel to the heated surfaces, the fins with 30o and 60o angles were placed in the channel horizontally with the impinging jet surface. While the channel height ( H) is 4D, the distance of the fin from the jet inlet ( N) is 2D. Fluids used in the channels are water, 0.02% GO-water and 2% diamond-water. The upper and lower surfaces of the channel and the fin are adiabatic and the flow Reynolds number range is 5000–15,000. The results of the work were compared with the experimental results of the studies in the literature and they were found to be consistent with each other. The results were presented as the mean Nu number and mean surface temperature variations for each model surface. Besides, the velocity and temperature contour distributions of the combined jet flow along the channel for diamond-water nanofluid were evaluated. Also, performance evaluation coefficient and average Nu number (Num), and surface temperature values (Tm) were evaluated at different Reynolds numbers for all three patterned surfaces in the channels. At Re = 15,000, there are 18.42% and 17.08% increments in Num value for cube and circular hollow model surfaces in the channel with 60o fin and GO-water nanofluid compared to the channel with water flow and without fin.

The distribution of geodesics on the cube surface

AbstractWe establish a Kronecker–Weyl type result, on time‐quantitative equidistribution for a natural non‐integrable system, geodesic flow on the cube surface. Our tool is the shortline‐ancestor method developed in Beck, Donders, and Yang [Acta Math. Hungar. 161 (2020), 66–184] and Beck, Donders, and Yang [Acta Math. Hungar. 162 (2020), 220–324], modified in an appropriate way to embrace all slopes. The method is further enhanced by the symmetry of the cube through the use of the irreducible representations of the symmetric group S4 which makes the determination of the irregularity exponent substantially simpler.

Spacecraft Charging Due To Energetic Electrons and Ions at Geosynchronous Altitudes

AbstractSatellites and spacecraft are usually exposed to space plasma disturbances, which vary in time at Geosynchronous Earth Orbit (GEO), affecting the charging of spacecraft and weather on the Earth. The charging currents are often described by the current‐balance equation (CBE) containing the electron‐ion (incoming/outgoing) current density fluxes and their energy distributions. The power‐law q‐distribution is the most generalized distribution that essentially characterizes more pronounced energy tails and can be reduced to standard Maxwellian distribution for q → 1. Using the equilibrium currents, the CBE is solved both analytically and numerically to study spacecraft charging within the framework of Whittaker function. It is found that energetic electron and ion‐induced currents significantly modify the charging phenomenon on the spacecraft's surface. Especially, ion‐induced currents result in the delay of negative charging at critical electron thermal energy and enhance the magnitude of the total normalized current. Apart from CuBe surface material, numerical analysis is also carried out for silver and Aluminum to determine the magnitude of total normalized current and onset of negative charging. The present findings are consistent with spacecraft charging at GEO altitudes around the Earth.

Rheology and microstructure of thermoresponsive composite gels of hematite pseudocubes and Pluronic F127.

Stimuli-responsive materials or smart materials are designed materials whose properties can be changed significantly by applying external stimuli, such as stress, electric or magnetic fields, light, temperature, and pH. We report the linear and nonlinear rheological properties of thermoresponsive composite gels based on submicron-sized hematite pseudocube-shaped particles and a triblock copolymer Pluronic F127 (PF127). These novel composites form hard gels at an elevated temperature of 37°C. For certain concentrations (<20 w/v. %) of hematite pseudocubes in 17.5 w/v. % of PF127, the gel strength is enhanced and the brittleness of the gels decreases. Higher concentrations (>20 w/v. %) of hematite pseudocubes in PF127 result in weaker and fragile gels. We develop an extensive rheological fingerprint using linear and nonlinear rheological studies. Adsorption of PF127 copolymer molecules on the hematite cube surfaces would further assist the formation of particle clusters along with magnetic interactions to be held effectively in the PF127 micellar network at elevated temperatures. The microscopic structure of these composite gels is visualized through a confocal microscope. Our experiments show that addition of hematite cubes up to 20 w/v. % does not change the rapid thermal gelation of PF127 solutions; hence, the hematite-PF127 composite, which transforms into a hard gel near human body temperature of 37°C, could be suitable for use in smart drug delivery systems.

RGO supported ZnO/SnO2 Z-scheme heterojunctions with enriched ROS production towards enhanced photocatalytic mineralization of phenolic compounds and antibiotics at low temperature

In the present study, the excellent photocatalytic activity of n-ZnO/n-SnO2 heterojunction integrated with reduced graphene oxide nanosheets was explored towards the elimination of different organic pollutants viz. p-bromophenol, bisphenol A, and ofloxacin from water. n-ZnO/n-SnO2 heterojunction was decorated with a different weight percentage of reduced graphene oxide via a facile refluxing method. The structural, morphological and optical properties of the as-prepared n-ZnO/n-SnO2 heterojunction-reduced graphene oxide nanocomposites were investigated systematically. XRD, Raman and FT-IR confirmed the hexagonal wurtzite and tetragonal rutile structures of ZnO and SnO2 crystals in different nanocomposites. Cube and spherical-shaped surface structures were demonstrated by TEM and FE-SEM analysis for ZnO and SnO2, respectively. The maximum photocatalytic productivity of nanocomposite with 5 wt% reduced graphene oxide was observed at about 98.64 % and 98.50 % towards the elimination of p-bromophenol and bisphenol A, respectively after 180 min exposure of UV light. Similarly, this productivity was also observed at about 99.13 % towards the elimination of ofloxacin after 120 min irradiation of UV light. The outstanding photocatalytic activity of nanocomposite with 5 wt% reduced graphene oxide has been proven by the presence of homotypic n-ZnO/n-SnO2 and reduced graphene oxide nanosheets owing to the synergistic effect amongst them resulting in remarkable separation of charge carriers, which is responsible for the larger rate of reactive oxygen species generation and enhanced photodegradation of p-bromophenol, bisphenol A and ofloxacin. In this study, the results illustrated that the photocatalytic degradation of p-bromophenol, bisphenol A and ofloxacin using n-ZnO/n-SnO2 heterojunction-reduced graphene oxide nanocomposites is predominantly based on the hydroxyl radicals and superoxide radical anion as main reactive oxygen species as compared to 1O2. A reasonable photodegradation mechanism using prepared nanocomposites under investigation has also been proposed.

The Cube Surface Light Field for Interactive Free-Viewpoint Rendering

Free-viewpoint rendering has always been one of the key motivations of image-based rendering and has broad application prospects in the field of virtual reality and augmented reality (VR/AR). The existing methods mainly adopt the traditional image-based rendering or learning-based frameworks, which have limited viewpoint freedom and poor time performance. In this paper, the cube surface light field is utilized to encode the scenes implicitly, and an interactive free-viewpoint rendering method is proposed to solve the above two problems simultaneously. The core of this method is a pure light ray-based representation using the cube surface light field. Using a fast single-layer ray casting algorithm to compute the light ray’s parameters, the rendering is achieved by a GPU-based three-dimensional (3D) compressed texture mapping that converts the corresponding light rays to the desired image. Experimental results show that the proposed method can real-time render the novel views at arbitrary viewpoints outside the cube surface, and the rendering results preserve high image quality. This research provides a valid experimental basis for the potential application value of content generation in VR/AR.

Affirmative nanosilica mediated approach against fungal biodeterioration of concrete materials

Microbial biodeterioration has been an important concern for concrete buildings’ durability over time. This study primarily emphasizes on the fungal biodeterioration of concrete and the effectiveness of silicon dioxide nanocoating on concrete in inhibiting fungal growth. A nanosilica coating was optimised and applied on concrete cube surface that was in turn infected with Aspergillus tamarii and monitored physical, mechanical, chemical as well as visual changes for a period of six months. The visual analysis included colour changes, Stereo Microscopy and Scanning Electron Microscopy (SEM) which showed a considerable change on the surface deterioration. Weight loss showed positive in all the concrete specimens (2.08% for biodeteriorated cubes and 2.13% for nanocoated cubes) whereas compressive strength that increased, 35.01% in nanocoated concrete cubes and 24.72% in biodeteriorated cubes. The chemical analysis included pH change in media, Fourier Transform Infrared Spectroscopy (FTIR) and Energy Dispersive X-Ray Fluorescence Spectroscopy (EDXRF) which showed that leaching of calcium ions from the concrete in biodeteriorated cubes was higher than that of nanocoated cubes. Altogether the efficacy of silicon oxide nanocoating against biodeterioration of concrete by Aspergillus tamarii was concluded to be positive.

The performance and microbial communities of Anammox and Sulfide-dependent autotrophic denitrification coupling system based on the gel immobilization

Anammox and sulfide-dependent autotrophic denitrification (ASDAD) coupling system can improve the nitrogen removal, but high sulfide concentration will affect the activity of anaerobic ammonia-oxidizing bacteria (AnAOB). Gel immobilization technology can enhance the survivability of microorganisms in unsuitable environments. Therefore, in this investigation, gel immobilization technology was applied into the ASDAD coupling system to explore the removal performance and microbial communities. The results showed that the optimal S2−/NO3– was 0.6, under which the best TN removal efficiency was 85.69%. The removal performance of ASDAD coupling system was stable under rapid variations of nitrogen loading rate and sulfide loading rate. Immobilized sludge cubes could attenuate the effects of temperature on AnAOB and sulfide-oxidizing bacteria. Observations of SEM and stereoscope suggested that AnAOB was more likely to exist on the surface of the sludge cubes. Thiobacillus, Candidatus Brocadia, and Candidatus Kuenenia were the main functional bacteria in the coupling system.

Investigation of the radiative heating of cubic particles with DEM/CFD and the BO/DO approach

The combined “Blocked-Off & Discrete Ordinates” (BO/DO) approach is used within a DEM/CFD frame to model the radiative heating of stationary and moving (rotating with respect to the mesh) cubic particles. A single cube, placed inside a larger cubic box, is heated by radiation and its temperature evolution over time is investigated. Two different models for the particle heating are considered: the first one assumes a uniform cube temperature while the second model calculates the intra-particle heat transfer leading to a non-uniform temperature distribution as it occurs in thermally thick particles. Three different particle materials, wood, styrofoam and steel, are considered.Initially, the radiative heating of stationary cubes, approximated by the BO approach in a CFD mesh, is compared to the heating of cubes enclosed by a corresponding body conformal mesh as a reference. The results show that deviations in cube temperature mainly result from the artificial increase of the particle surface in the BO. When applying a particle surface area ratio to compensate for the artificial surface area increase deviations in temperature can be reduced to 5.2% compared to body conformal mesh.In a further step, the cube is constantly rotating which changes the orientation of the cube's surfaces relative to the radiation source. The evolution of the cube's surface temperatures, which is dependent on the orientation, is modelled by the BO/DO approach. As expected, materials with low thermal conductivity show larger temperature gradients over time than materials with high thermal conductivity. The temperature difference between different surfaces turns out to be in the ranges 50/14/0 K (for styrofoam/wood/steel) and 134/65/0 K between surface and core, thus reflecting the correct physical behavior. The evaluation of the BO/DO approach concerning its capability to account for radiative heat transfer in DEM simulations for particles with a regular (cubic) geometry, as examined in the current paper, forms the basis to extend the description to arbitrarily shaped particles, a great potential of the BO/DO approach as will be shown in an outlook example.

Facile synthesis of nanocellulose-based Cu2O/Ag heterostructure as a surface-enhanced Raman scattering substrate for trace dye detection.

Semiconductor metal-oxide/metal heterostructures with synergetic properties have potential applications in photocatalysis and optical sensors. Here, Cu2O sub-micro cubes were synthesized under environmentally benign conditions using 2, 2, 6, 6-tetramethylpyperdine-1-oxyl (TEMPO)-oxidized cellulose nanofibrils as a reducing and stabilizing agent. Then the surface of the Cu2O cubes was decorated with silver nanoparticles (AgNPs) by a substitution reaction. The Cu2O/Ag heterostructures within the cellulose nanofibrils (CNFs) network were employed as a promising surface-enhanced Raman scattering (SERS) assay for efficient sensing of methylene blue (MB), reaching a maximum enhancement factor (EF) of 4.0×104. Their SERS intensities depended on the coverage density of AgNPs and the wavelength of the excitation laser. The excellent SERS performance may result from the charge transfer between Ag and Cu2O molecules and the strong electromagnetic field at the interface. The CNF-Cu2O/Ag substrates were capable of detecting MB dye down to 10-8M level with a relative standard deviation of 10-15%, demonstrating great sensitivity and reproducibility.