Selection Of Particle Size Research Articles

Theoretical predictions to facilitate the method development in slalom chromatography for the separation of large DNA molecules

Slalom chromatography (SC) re-emerged in 2024 due to the availability of low adsorption ultra-high pressure liquid chromatography (UHPLC) packed columns/instruments and large modalities being investigated in the context of cell and gene therapies. The physico-chemical principles of SC retention combined with hydrodynamic chromatography (HDC) exclusion have been recently reported. In SC, DNA macromolecules are retarded because: (1) they can be stretched to lengths comparable to the particle diameter, and (2) their elastic relaxation time is long enough to maintain them in non-equilibrium extended conformations under regular UHPLC shear flow conditions. Here, a quantitative HDC-SC retention model is consolidated. A general plate height model accounting for the band broadening of long DNA biopolymers along packed beds is also derived for supporting method development and predicting speed-resolution performance in SC.For illustration, the chromatographic speed-resolution properties in SC are predicted for the separation of specific critical pairs (4.0/4.5, 10/11, and 25/27 kbp) of linear dsDNA polymers. The calculations are performed for two available custom-made particle sizes, dp= 1.7 and 2.5μm, at a constant pressure of 10,000 psi. The predictions are directly validated from experimental data acquired using low adsorption MaxPeakTM 4.6 mm i.d. Columns packed with 1.7μm BEHTM 45 Å (15 cm long column) and 2.5μm BEH 125 Å (30 cm long column) Particles, and by injecting six linear dsDNAs (λ DNA-Hind III Digest). The LC system is very low dispersion ACQUITYTM UPLCTM I-class PLUS System, and the mobile phase is a 100 mM phosphate buffer at pH 8. Maximum resolution is always achieved when the average extended lengths of linear dsDNAs are equal to a critical length, which is proportional to the particle diameter and to the square root of the applied shear rate. Most advantageously, the experimental results reveal that the relaxation times of linear dsDNAs observed under shear flow conditions are two orders of magnitude shorter than those expected in the absence of flow: this enables the detection of the longest linear dsDNAs up to 25 kbp without irremediable loss in column performance. Finally, the retention-efficiency model elaborated in this work can be used to rapidly anticipate and develop methods (selection of particle size, column length, and operating pressure) for any targeted DNA and time-resolution constraints.

Preparation of CrB2 mixtures and formation of briquettes for drill bit composites

The research described in the article concerns advanced methods of creating composite materials for drill bits used in extreme conditions of deep wells. The main attention is paid to development of multicomponent mixtures that ensure uniform distribution of powders of tungsten carbide, cobalt, chromium diboride and diamond. This is achieved through careful selection of particle size and proportions, which is critically important to ensure high strength and wear resistance of final materials. The Spark Plasma Sintering (SPS) method was chosen for the production of samples of carbide matrices and composite diamond-containing materials because of its ability to provide high density and uniformity of the material. SPS allows temperature and pressure control during sintering process, which contributes to the formation of materials with optimal physical properties. The article also discusses in detail design parameters of the diamond bit, including the choice of grain size of diamond powder and other components. These meters have been optimized to max-imize drilling efficiency and extend tool life. The diamond powders used in study were obtained from De Beers, South Africa and are characterized by high quality and uniformity. The results presented in the article can have a significant impact on future production of drilling tools, offering new approaches to choice of materials and methods of their processing, which ultimately can lead lower drilling costs and increased process safety. These innovations can also contribute to more efficient development of new fields, which is of great importance for the energy industry and the mining industry.

Characterizing stress development and cracking of ceramic particulate coatings during drying

AbstractDuring drying, liquid‐applied particulate coatings develop stress and are consequently prone to stress‐induced defects, such as cracking, curling, and delamination. In this work, the stress development and cracking of coatings, prepared from aqueous silica and zinc oxide particle suspensions, were characterized using cantilever beam deflection with simultaneous imaging of the coating surface. Drying uniformity was improved and lateral or edge‐in drying was discouraged by using thin silicone walls around the perimeter of the cantilever. Coatings prepared from larger monodisperse silica particles (D50 ∼ 0.9 µm) dried uniformly but had a high critical cracking thickness (>150 µm) that prevented simultaneous study of stress development and cracking. Coatings prepared from smaller silica particles (D50 ∼ 0.3 µm) cracked readily at low thicknesses but exhibited edge‐in drying that complicated the stress measurement data. This drying nonuniformity was connected to the potential for these small particles to accumulate at the coating surface during drying. Hence, the selection of particle size and density was critical to drying uniformity when characterizing stress development and cracking. Coatings prepared from suspensions of zinc oxide particles (D50 ∼ 0.4 µm) were well‐suited for these studies, with uniform drying stress peaking at ∼1 MPa. Characteristic features in the stress development data above and below the critical cracking thickness (53 µm) were identified, demonstrating that cantilever beam deflection is a useful tool for studying the effectiveness of crack mitigation methods and the fundamentals of coating fracture during drying.

Size effect on the pyrolysis of 1,3,5-triamino-2,4,6-trinitrobenzene (TATB) nanoparticles: a ReaxFF molecular dynamics study.

The nanoscale form of the typical insensitive energetic material 1,3,5-triamino-2,4,6-trinitrobenzene (TATB) exhibits the capability to improve the energy performances while maintaining low sensitivity compared to raw TATB. Investigating the particle size effect on the intrinsic pyrolysis mechanisms facilitates the selection of the TATB particle size in applications to ensure efficient energy release and high safety levels. However, the intrinsic mechanism of this effect remains unclear. This study focuses on pyrolysis as a prerequisite behavior for energy release, employing reactive molecular dynamics simulations to investigate the pyrolysis of TATB nanoparticles with different sizes, aiming to explore the qualitative changes in thermal properties at the atomic level. Results demonstrate that with increasing particle size, the decomposition rate of TATB decreases. Smaller particles exhibit a propensity towards dehydrogenation and C-NO2 bond cleavage reactions. However, larger nano-TATB particles demonstrate a preference for dimerization, which results in the formation of clusters with greater polymerization and increased stability. The highly polymerized clusters are stable under thermal stimulation, inhibiting further decomposition of TATB. These insights reveal the mechanism underlying the qualitative change in the energy performance of TATB nanoparticles at the atomic level.

Fast fabrication of high entropy oxides electrodes for flexible zinc-ion batteries with high electrochemical performance

The expanding world population, increasing energy demand, and looming climate change urge the development of a sustainable energy future while safeguarding our vulnerable environment. To build a new flexible battery system, high entropy oxides are used as electrodes based on zinc-ion batteries. The battery system with the best electrochemical performance can be determined by a series of experimental designs. Here in I propose to develop a HEO electrode using a fast and clean laser deposition method. A series of tests are designed to verify the degree of performance improvement. In the further research planning, the electrode material can be produced with a metal removed from the HEOs alone and using the same synthetic method and performance measurements to determine the roles of each metal in the HEOs. Additionally, the anions in the HEOs can also be varied to study the impact of various anions on the cell's electrochemical performance. Finally, the particle size of the HEOs can be varied to establish a correspondence between particle size and electrochemical performance to facilitate the selection of the optimum particle sizes. The experimental results can further provide a theoretical basis for the commercial application of zinc-ion batteries in flexible power systems.

Structural Color Mixing in Microcapsules through Exclusive Crystallization of Binary and Ternary Colloids.

Colloidal crystals are designed as photonic microparticles for various applications. However, conventional microparticles generally have only one stopband from a single lattice constant, which restricts the range of colors and optical codes available. Here, photonic microcapsules are created that contain two or three distinct crystalline grains, resulting in dual or triple stopbands that offer a wider range of colors through structural color mixing. To produce distinct colloidal crystallites from binary or ternary colloidal mixtures, the interparticle interaction is manipulated using depletion forces in double-emulsion droplets. Aqueous dispersions of binary or ternary colloidal mixtures in the innermost droplet are gently concentrated in the presence of a depletant and salt by imposing hypertonic conditions. Different-sized particles crystallize into their own crystals rather than forming random glassy alloys to minimize free energy. The average size of the crystalline grains can be adjusted with osmotic pressure, and the relative ratio of distinct grains can be controlled with the mixing ratio of particles. The resulting microcapsules with small grains and high surface coverage are almost optically isotropic and exhibit highly-saturated mixed structural colors and multiple reflectance peaks. The mixed color and reflectance spectrum are controllable with the selection of particle sizes and mixing ratios.

Variation of Flow Hydrodynamic Parameters and Prediction of Particle Separation Indices in the Spiral Concentrator with the Regulation of Pitch-Diameter Ratio

The pitch-diameter ratio is an important design indicator affecting the separation performance of spirals. Based on the numerical simulation method, this paper systematically investigated the variation of flow hydrodynamic parameters in the spiral concentrator with the regulation of the pitch-diameter ratio. The radial distribution and variation trend of hematite and quartz particles with different particle sizes are further analyzed. Additionally, the separation indices of hematite and quartz with different particle size combinations were predicted. The results show that the tangential velocity, maximum radial velocity, velocity shear rate, and Reynolds number of fluid in each region decrease with the increase of the pitch-diameter ratio. The range of laminar flow gradually expands as the pitch-diameter ratio increases. There are significant differences in depth of water, ratio of inward and outward flows, and secondary flow velocity in different regions. Some flow hydrodynamic parameters at the inner trough reach relative equilibrium at a pitch-diameter ratio of 0.675. Hematite and quartz particles form a selective distribution in the trough surface, which comprehensively reflects the density effect, particle size effect, following flow effect of fine particles, and the effect of interstitial trickling of high-density fine particles. Fine hematite and coarse quartz form a large amount of misplaced material, and there is a corresponding mixing area. With the increase in pitch-diameter ratio, coarse and fine hematite particles migrate inward and outward, respectively. With the increase in pitch-diameter ratio, the misplaced amount of quartz on the inner trough decreases, but the outward migration distance of coarse quartz is smaller. Increasing the pitch-diameter ratio is beneficial to the separation of combined feedings of coarse hematite and quartz but unfavorable to that of fine hematite and quartz. The maximum separation efficiency of coarse hematite and fine quartz can reach 85.74%, and the iron grade of the inner product can reach 65.96% when the pitch-diameter ratio is 0.675 and the splitter location is 115 mm. The changing trend of separation indices in this feeding is closely related to the variation of fluid parameters and the change in the radial distribution of single mineral particles. The research results can provide references for the structural design of spirals, the selection of feed particle size, and the adjustment of splitter location.

Attack Site Density of a Highly-efficient PET Hydrolases.

Poly (ethylene terephthalate) (PET) is one of the most abundant polyester materials used in daily life and it is also one of the main culprits of environmental pollution. ICCG (F243I/D238C/S283C/Y127G) is an enzyme that performs four modifications on the leaf branch compost keratase (LCC). It shows excellent performance in the hydrolysis of PET and has a great potential in further applications. Here, we used ICCG to degrade PET particles of various sizes and use the density of attack sites (Γattack) and kinetic parameters to evaluate the effect of particle size on enzyme degradation efficiency. We are surprised to observe that there is a certain relationship between Km and Γattack. In order to further confirm the relationship, we obtained three different enzymes (Y95K, M166S and H218S) by site-directed mutagenesis on the basis of ICCG. The results confirmed that there was a negative correlation between Km and Γattack. In addition, we also found that increasing the affinity between the enzyme and the substrate does not necessarily lead to the increase of degradation rate. These findings show that the granulation of PET and the selection of appropriate particle size are helpful to improve its industrial application value. At the same time, additional protein engineering to increase ICCG performance is realistic, but it can't be limited to enhance the affinity between enzyme and substrate.

Analysis of a landfill cover without geomembrane using varied particle sizes of recycled concrete

Previous studies have demonstrated the effectiveness of a novel three-layer landfill cover system constructed with recycled concrete aggregates (RCAs) without geomembrane in both laboratory and field. However, no systematic investigation has been carried out to optimize the combination of the particle sizes for fine-grained RCAs (FRC) and coarse-grained RCAs (CRC) that can be used for the three-layer landfill cover system. The aim of this paper is to assist engineers in designing the three-layer landfill cover system under a rainfall of 100-year return period in humid climate conditions using an easily controlled soil parameter D 10 of RCAs. The numerical study reveals that when D 10 of FRC increases from 0.05 mm to 0.16 mm, its saturated permeability increases by 10 times. As a result, a larger amount of rainwater infiltrates into the cover system, causing a higher lateral diversion in both the top FRC and middle CRC layers. No further changes in the lateral diversion are observed when the D 10 value of FRC is larger than 0.16 mm. Both the particle sizes of FRC and CRC layers are shown to have a minor influence on the percolation under the extreme rainfall event. This implies that the selection of particle sizes for the FRC and CRC layers can be based on the availability of materials. Although it is well known that the bottom layer of the cover system should be constructed with very fine-grained soils if possible, this study provides an upper limit to the particle size that can be used in the bottom layer ( D 10 not larger than 0.02 mm). With this limit, the three-layer system can still minimize the water percolation to meet the design criterion (30 mm/yr) even under a 100-year return period of rainfall in humid climates.

Research on the seepage properties of coal with different particle size proppant under cyclic loading

The selection of proppant particle size significantly impacts the gas output and gas production period of the extracting coalbed methane (CBM). This study combines theoretical analysis and permeability testing, based on the in situ stress distribution characteristics of the coal seam in Wangjiazhai Coal Mine, Guizhou Province, conducted on artificial fractures with different particle size proppant combinations during the cyclic loading and unloading. The findings indicate that the coal sample with two particle sizes of proppant has more permeability and smaller stress sensitivity coefficient than the coal sample with a single particle size proppant; as effective stress increases, the coal sample with the maximum permeability and the smallest stress sensitivity coefficient is placed with a proppant ratio of 20/40 mesh to 40/70 mesh of 1–3. The stress sensitivity coefficient and the permeability decrease with an increase in the number of confining pressure cycles. The increase in the proppant embedding depth has a hysteresis phenomenon with the increase in the effective stress, and the coal sample with a proppant ratio of 20/40 mesh to 40/70 mesh of 1–3 has the smallest embedded depth. The proppant will cause damage to the fracture surface of the coal seam. This study provides technical support for efficiently extracting the CBM resources that are difficult to exploit in Guizhou Province.

Characteristic of particles created by preparatory operationsof the particleboard production process

Characteristic of particles created by preparatory operations of the particleboard production process.The production of wood-based panels, taking into account material innovations, involves the need to adjust the operation of technological devices to the properties of basic and auxiliary materials. In this study, it was decided to check the particle sizes after sorting raw materials representing 3 groups: forest biomass – pine branches, agricultural biomass - oilseed plant straw, and post-production material. Fractions were taken from the 2.00 mm mesh sieve of a sorter for the core layer of the particleboard and the fractional composition was determined by sieve analysis. The average linear particle dimensions and bulk density of each lignocellulosic raw material were also determined. Due to the varying proportions, it is necessary to adapt the parameters of the technological operations to the specifics of the raw material being processed or to introduce guidelines for the selection of particle sizes guided by their actual average size. Studies have shown differences between the individual materials. This is particularly important, as proper preparation of the raw material translates into the quality of the boards produced from them and the efficiency of the entire process.

Downstream processing of amorphous solid dispersions into orodispersible tablets

The formulation development of amorphous solid dispersions (ASDs) towards a patient-friendly oral solid dosage form is proving to be still challenging. To increase patient’s compliance orodispersible tablets (ODTs) can be seen as promising alternative. Two different ASDs were prepared via hot melt extrusion (HME), using PVPVA as polymer for ritonavir (RTV) and HPMCAS for lopinavir (LPV). The extrudates were milled, sieved, and blended with Hisorad® (HRD) or Ludiflash® (LF), two established co-processed excipients (CPE) prior to tableting. Interestingly, the selected ASD particle size was pointed out to be a key parameter for a fast disintegration and high mechanical strength. In terms of PVPVA based ASDs, larger particle sizes > 500 µm enabled a rapid disintegration even under 30 s for 50 % ASD loaded ODTs, whereas the use of smaller particles went along with significant higher disintegration times. However, the influence of the CPE was immense for PVPVA based ASDs, since it was only possible to prepare well performing ODTs, when Hisorad® was chosen. In contrast for HPMCAS based ASDs the selection of smaller particle sizes 180–500 µm was beneficial for overcoming the poor compressibility of the ASD matrix polymer. ODTs with LPV could be produced using both CPEs even with higher ASD loads up to 75 %, while still showing remarkably fast disintegration.

Investigation of the effects of particle size on the performance of classical gravity concentration equipment

ABSTRACT The use of gravity concentrators involves several challenges, such as determination of the liberation sizes of the minerals, selection of appropriate particle sizes for the applied concentration method, and the severity of the beneficiation of fines.In this study, the effects of fully liberated (artificial mixtures of magnetite and quartz) and non-liberated particles (chromite ore collected from a chromite processing plant) on various gravity concentration equipment were investigated as a function of particle size considering recoveries, separation efficiencies, and grades of products. A series of tests were conducted on shaking tables, spiral concentrators, and a Falcon concentrator with different design features under various operating conditions. Finally, the separation efficiencies were correlated with the settling rates of the particles.The test results confirmed a certain trend in the separation efficiency as a function of particle size for each condition. The separation efficiency initially increased with increasing particle size, peaked, and eventually decreased with increasing particle size. The maximum separation efficiency attained was 90% for 141 µm particles in the shaking table and 54% for 245 µm particles in the Falcon concentrator, both of which were used to treat the artificial feed. In the spiral concentrator, which treated chromite ore as feed, the maximum separation efficiency attained was 82% for 178 µm particles.This experimental study provides data to identify the concentration behavior of particles by investigating possible separation mechanisms. Consequently, it provides an understanding of the relationships between particle size and separation efficiency in terms of settling rates, especially in spiral concentrators.

INTEGRATED STORMWATER ANALYSIS MODEL TO SUPPORT SUSTAINABLE URBAN GREEN SPACE DESIGN

Abstract. Urban Green Space (UGS) has been broadly treated as a valuable and limited resource to handle the challenges brought by high-density urban environment. Green stormwater management has been prompt around the world. To reduce the potential conflicts between stormwater management and other requirements on UGS (especially human needs), the research community and governments encourage the urban planners and designers to integrate stormwater analysis into UGS design. However, the professional term and operation of the traditional hydrological model is a huge challenge to the designers who haven’t touched hydrological knowledge. This study developed a method to simulate and quantify stormwater in UGS by the particle system in the design platform- Rhinoceros +Grasshopper. In this method, we adopted five groups of urban objects such as terrain, building footprint etc. to ease procedures and performance. To overcome the issue the abstracted particle movement cannot reflect the infiltration features of land cover, we introduced categorising locations of the particles and the UGS retaining stormwater hypothesis. To test the feasibility of the method, we tested the three parameters of the integrated model: iteration times, rainfall depth ( selected rainfall event) and particle radius. The comparison tests prove: (1) too small iteration times would lead the particles to stop on the way to the bottom of the terrain, so we set at least 4000 iteration times for simulation; (2) the sensitivity to the selection of rainfall event and particle size is relatively low, the simulation results vary by 1%; (3) too small particle numbers will impact the accuracy of analysis, so we should balance accuracy and work efficiency of work; (4) the stormwater volume estimation based on the particle system is acceptable. The experiments confirm the method can effectively support preliminary UGS design work.

High throughput synthesis of CoCrFeNiTi high entropy alloys via directed energy deposition

Blown-powder additive manufacturing process, directed energy deposition (DED) is applicable to scale-up material development with cost-effective elemental powder mixtures. In this paper, the effectiveness of applying DED to the design and synthesis of model CoCrFeNiTi high entropy alloys (HEAs) was demonstrated. Through a careful design of composition and delicate selection of particle size and shape, three CoCrFeNiTi HEAs with different microstructures were in-situ synthesized from premixed elemental powders. Transmission electron microscopy, scanning electron microscopy, energy-dispersive X-ray spectroscopy, and X-ray diffraction were used for microstructure characterization. H3-Co 24.4 Cr 17.4 Fe 17.5 Ni 24.2 Ti 16.5 in at% (close to Co 1.5 CrFeNi 1.5 Ti) was fabricated with a soft face-centered cubic (FCC)-γ phase structure while hard intermetallic phases such as σ-FeCr, δ-NiTi 2 , and a small amount of Ni 3 Ti 2 were precipitated and uniformed distributed in the FCC matrix for H1-Co 22.2 Cr 16.1 Fe 19 Ni 21.8 Ti 20.9 and H2-Co 25.9 Cr 15 Fe 17 Ni 20.8 Ti 21.3 . With a large percent of the secondary phases, H1 exhibited a hardness value of about 853 HV 0.5 . These HEAs displayed a high oxidation resistance comparable to Inconel 625 superalloy. A detailed evaluation of the composition, microstructure, hardness, oxidation resistance, and wear resistance of these HEAs was conducted as compared with those of a reference HEA and two popular wear-resistant steels. • CoCrFeNiTi high entropy alloys were synthesized via directed energy deposition. • Compositions were controlled by elemental powders with specified size and shape. • A high oxidation resistance comparable to IN625 was obtained. • High fraction of secondary reinforcements led to hardness higher than tool steel.

Effect of NdFeB particle size on the performance of 3D printed bonded magnets of polyamide‐based composites

AbstractAdditive manufacturing has been widely used in the field of bonded magnets manufacturing. However, there are some key issues to be faced in order to obtain bonded magnets (BMs) with high performance. In this study, four different particle sizes of flake NdFeB powder (volume‐weighted mean diameter [VMD] of 5.60 μm, 19.21 μm, 33.25 μm, and 66.69 μm) were obtained by vibratory sieving. Flexible filaments for 3D printing BMs were produced using polyamide‐6 (PA6) as the substrate, and the production process is reported in this paper. Characterization of the performance of the 3D‐printed BMs revealed that the BMs with VMD less than 10 μm have excellent mechanical strength, but the ductility of the magnets decreases with decreasing VMD of NdFeB powder. As the NdFeB VMD decreases, the coercivity of the sample decreases and the remanence increases. This study provides a reference for the selection of filler particle size for 3D printing BMs, which can be used to develop 3D‐printed BMs with excellent performance.

Growth and Mechanical Characterization of Mycelium-Based Composites towards Future Bioremediation and Food Production in the Material Manufacturing Cycle.

Today’s architectural and agricultural practices negatively impact the planet. Mycelium-based composites are widely researched with the aim of producing sustainable building materials by upcycling organic byproducts. To go further, this study analyzed the growth process and tested the mechanical behavior of composite materials grown from fungal species used in bioremediation. Agricultural waste containing high levels of fertilizers serves as the substrate for mycelium growth to reduce chemical dispersal in the environment. Compression and three-point bending tests were conducted to evaluate the effects of the following variables on the mechanical behavior of mycelium-based materials: substrate particle size (with or without micro-particles), fungal species (Pleurotus ostreatus and Coprinus comatus), and post-growth treatment (dried, baked, compacted then dried, and compacted then baked). Overall, the density of the material positively correlated with its Young’s and elastic moduli, showing higher moduli for composites made from substrate with micro-particles and for compacted composites. Compacted then baked composites grown on the substrate with micro-particles provided the highest elastic moduli in compression and flexural testing. In conclusion, this study provides valuable insight into the selection of substrate particle size, fungal species, and post-growth treatment for various applications with a focus on material manufacturing, food production, and bioremediation.

Volatile compounds in espresso resulting from a refined selection of particle size of coffee powder

Volatile organic compounds (VOCs) influence significantly sensory properties of espresso coffee (EC). However, some of these chemicals, such as furans reported to have a negative impact on human health. This study aimed to monitor 21 key main VOCs of coffee brew and two undesirable compounds such as furan and 2-methylfuran in Robusta and Arabica EC samples as a function of specific particle size fractions (F1 <200, 200 <F2 <300, 300 <F3 <425, F4 >425 µm). The evolution of the volatile compounds was studied by HS-SPME-GC/MS. The results showed that volatile compounds are released differently in the EC depending on coffee species and the specific particle size. In Robusta ECs the highest concentration of volatile compounds was obtained using 200 <F< 300 µm except for furan, 2-methylfuran and 2,5-dimethylfuran. Arabica ECs resulted particle size-independent for aldehydes, except for hexanal, phenolic compounds, and some furans and non-monotonic with the highest amount in the 300 <F< 425 for the nitrogen-containing heterocyclic compounds. With regard to furan and 2-methylfuran monotonic increase was observed along the increasing particle size degree. The HCA analysis separated in four different groups the coffees particle size; Arabica-F1, Arabica-F3 and Robusta-F3 formed the first group, the second included Arabica-F2 and Arabica-F4, the third group consisted of Robusta-F1 and Robusta-F4 and the last one included only Robusta-F2. These results can help to design a-priori unique blends based on appropriate combinations of particle sizes and coffee species to produce an EC with higher aromatic levels while simultaneously lowering levels of furan and 2-methylfuran.

Control of Nanoscale Heat Generation with Lithography-Free Metasurface Absorbers.

Metasurfaces, artificially engineered surfaces comprised of subwavelength resonators, show promise for realizing a new generation of optical materials and devices. However, current metasurface architectures suffer from environmental degradation, a limited spectral range, and a lack of scalability. Here, we demonstrate a novel large-area embedded metasurface architecture that is environmentally robust and capable of a spectrally selective absorption of greater than 80% spanning from 330 to 2740 nm. These fully encapsulated metasurfaces leverage the capabilities of colloidal plasmonic nanoparticles with various crystallinities, materials, shapes, and sizes to access a larger spectral range and allow for control of nanoscale spatial losses and subsequent heat generation within the constituent elements of the metasurface. Through the selection of material, particle size, and shape, these metasurfaces can be designed across the ultraviolet (UV) to short-wave infrared (SWIR) region for various hot-electron, photodetection, photocatalysis, and photothermal processes.

Experimental Study on Measurement of Interfacial Pressure in Granular Materials

Abstract The properties of storage system structures were largely determined by the particle size and compressive modulus of the granular material inside, which is an important issue for silo structure design. The large compressibility and complex contact relationship of granular materials in the cell are needed for the reliable pressure measurement. A set of testing system and experiment method were designed to reveal the size effect of earth pressure cells in the loading and unloading process of granular materials. Different compressive moduli were adopted for the selection of the appropriate granular particle size. Four types of granular materials including fine sand, coarse sand, rapeseed, and wheat were used as raw materials. Three types of earth pressure cells were used in this study with different sizes, and a series of loading and unloading tests were conducted with liquid. The interaction between the cell and granular material and its main factors were discussed. The results show that the pressure exhibits a linear relationship with the strain in the loading and unloading process in liquid surroundings. Owing to the interaction between the cell and granular materials, the pressure increased linearly with the strain in the loading process as well as a nonlinear relationship were exhibited in the unloading process. In the unloading process, an exponential model was proposed to simulate the pressure and strain based on the significant hysteresis phenomenon observed during unloading process. The hysteresis ratio (R) index was adopted to evaluate the hysteresis. It was found that the material type of surroundings and particle size were believed to be the two major factors affecting the R value. To improve the accuracy of granular material interface pressure measurement, the earth pressure cell with a d/d0 ratio exceeding 11 was recommended. The results obtained in this study provide theoretical foundation for energy saving and safety granary structure design.