Feature Size Research Articles

Impact of lipid droplet characteristics on the rheology of plant protein emulsion gels: Droplet size, concentration, and interfacial properties

Plant-based meat analogs are being developed to address environmental, sustainability, health, and animal welfare concerns associated with real meat products. However, it is challenging to mimic the desirable physicochemical, functional, and sensory properties of real meat products using plant-based ingredients. Emulsion gels consisting of lipid droplets embedded in biopolymer matrices are commonly used to create products with appearances, textures, and sensory attributes like meat products. In this study, the impact of soybean oil droplet characteristics (concentration, size, and charge) on the physicochemical properties of potato protein gels was studied. The oil droplets were either coated by a non-ionic surfactant (Tween 20) or a plant protein (patatin) to obtain different surface properties. The introduction of the oil droplets caused the protein gels to change from mauve to off-white, which was attributed to increased light scattering. Increasing the oil droplet concentration in the emulsion gels decreased their shear modulus and Young’s modulus, which was mainly attributed to the fact that the oil droplets were less rigid than the surrounding protein network. Moreover, increasing the oil droplet size made this effect more pronounced, which was attributed to their greater deformability. Competitive adsorption of proteins and surfactants at the oi-water interface in the Tween emulsion promoted emulsion instability. This research highlights the complexity of the interactions between oil droplets and protein networks in emulsion gels. These insights are important for the utilization of emulsion gels in the formulation of plant-based foods with improved quality attributes.

Designing Plastrons for Underwater Bubble Capture: From Model Microstructures to Stochastic Nanostructures.

Bubbles and foams are often removed via chemical defoamers and/or mechanical agitation. Designing surfaces that promote chemical-free and energy-passive bubble capture is desirable for numerous industrial processes, including mineral flotation, wastewater treatment, and electrolysis. When immersed, super-liquid-repellent surfaces form plastrons, which are textured solid topographies with interconnected gas domains. Plastrons exhibit the remarkable ability of capturing bubbles through coalescence. However, the two-step mechanics of plastron-induced bubble coalescence, namely, rupture (initiation and location) and subsequent absorption (propagation and drainage) are not well understood. Here, the influence of 1) topographical feature size and 2) gas fraction on bubble capture dynamics is investigated. Smaller feature sizes accelerate rupture while larger gas fractions markedly improve absorption. Rupture is initiated solely on solid domains and is more probable near the edges of solid features. Yet, rupture time becomes longer as solid fraction increases. This counterintuitive behavior represents unexpected complexities. Upon rupture, the bubble's moving liquid-solid contact line influences its absorption rate and equilibrium state. These findings show the importance of rationally minimizing surface feature sizes and contact line interactions for rapid bubble rupture and absorption. This work provides key design principles for plastron-induced bubble coalescence, inspiring future development of industrially-relevant surfaces for underwater bubble capture.

Predicting behavior in extinct reptiles from quantitative analysis of trigeminal osteological correlates

IntroductionVertebrate sensory systems are in close contact with surrounding tissues, often leaving bony signatures behind. These bony features are the keys to assessing variation in sensory systems in fossil taxa. The trigeminal sensory system (e.g., trigeminal ganglion, ophthalmic, maxillary, and mandibular divisions) has osteological correlates throughout the skull, including the braincase (e.g., trigeminal fossa, prootic notch, ophthalmic and maxillomandibular foramina) and rostrum (e.g., mandibular canal, neurovascular foramina).MethodsHere we measured and compared these features among a morphologically, phylogenetically, and ecologically diverse sample of sauropsids to determine strength of osteological correlates and to explore ecomorphological trends. We determined several suitable osteological correlates for trigeminal soft tissue features and discounted foramen count alone as a suitable osteological correlate. However, when size was accounted for, foramen count becomes a useful indicator of sensory ecology.Results and discussionAmong extant taxa, those engaging in tactile sensory behaviors with the face exhibit relatively larger trigeminal tissues and osteological correlates than those not engaging in tactile sensory behaviors. Though patterns are unclear among several clades, both relative feature sizes and models used to predict sensory capacity reveal a trend of increasing tactile sensitivity along the pseudosuchian lineage. Overall, a quantitative assessment of ecomorphological trends of trigeminal osteological correlates proves informative for the hypotheses of sensory behavior in extinct taxa and supports the use of similar assessment methods for other osteological correlates.

Approximation of eigenvalues and eigenfunctions of the diffusion operator in a domain containing thin tubes by asymptotic domain decomposition method

We consider the spectral problem for the diffusion operator considered in a domain containing thin tubes. A new version of the method of partial asymptotic decomposition of the domain is introduced to reduce the dimension inside the tubes, getting a model of hybrid dimensions. The method truncates the tubes at some small distance from the ends of the tubes and replaces the longer part of the tubes with segments. At the interface of the three-dimensional and one-dimensional subdomains, special junction conditions are set: the pointwise continuity of the flux and the continuity of the average over a cross-section of the eigenfunctions. We obtain conditions on the ratio of the characteristic sizes in the transverse and longitudinal directions that ensure the closeness of two spectra, i.e. of the diffusion operator in the full-dimensional domain and the partially reduced one, keeping the conservation of the multiplicity, all up to a prescribed accuracy.

Concurrent multiscale topology optimization for size-dependent structures incorporating multiple-phase materials

The significant progress in additive manufacturing has resulted in the development of well-engineered microstructures with innovative topological configurations, showcasing exceptional performance across diverse fields. Topology optimization is widely recognized as an advanced design tool that provides engineers with new insights for creating lightweight structures. As integration devices continue to trend towards miniaturization, the size effect in small-scale structures remains a persistent challenge. The absence of characteristic parameters to describe this size effect hinders proper explanation through traditional multiscale topology optimization based on classical mechanics. Therefore, we propose a size-dependent topology optimization framework for concurrent multiscale design involving multiple-phase materials. The modified couple stress theory is proposed to account for the size effect in small-scale structures. The numerical findings suggest that the size effect is significantly influenced by the ratio of elastic modulus, volume fraction, and width-to-length ratio of the representative volume element as its characteristic size approaches the length of the material. These results highlight the importance of considering size-dependent effects in topology optimization for multiscale design and provide valuable insights for engineers and researchers in this field.

Droplet dynamics in homogeneous isotropic turbulence with the immersed boundary-lattice Boltzmann method.

We develop a numerical method for simulating the dynamics of a droplet immersed in a generic time-dependent velocity gradient field. This approach is grounded on the hybrid coupling between the lattice Boltzmann (LB) method, employed for the flow simulation, and the immersed boundary (IB) method, utilized to couple the droplet with the surrounding fluid. We show how to enrich the numerical scheme with a mesh regularization technique, allowing droplets to sustain large deformations. The resulting methodology is adapted to simulate the dynamics of droplets in homogeneous and isotropic turbulence, with the characteristic size of the droplet being smaller than the characteristic Kolmogorov scale of the outer turbulent flow. We report statistical results for droplet deformation and orientation collected from an ensemble of turbulent trajectories, as well as comparisons with theoretical models in the limit of small deformation.

Plasmonic magnesium arrays with nanosphere lithography

Magnesium is a rising alternative plasmonic metal that is potentially cheaper, more biocompatible, and less lossy in the ultraviolet-blue region of the visible spectrum than the commonly used gold and silver. Recent studies of colloidal magnesium nanoparticles demonstrated the plasmonic resonances of a variety of faceted shapes. However, applications such as refractive index sensing benefit from well-defined arrays, which have been developed for all other plasmonic metals. Here, we implement nanosphere lithography to fabricate metallic magnesium arrays that display attractive plasmonic properties. The deposition process was found to be highly vulnerable to oxidation, recrystallization, kinetic energy of the metal vapor, and substrate properties. The resulting structures obtained with 350, 500, and 750 nm hexagonally packed nanosphere masks exhibit the hallmark light–matter interactions of plasmonic metals, including strong extinction and resonance energy dependence on feature size, further securing Mg’s place as an alternative plasmonic metal.

Detection of Red Blood Cell Aggregation Regions by Feature Point Extraction and Size Estimation by Clustering

Detection of Red Blood Cell Aggregation Regions by Feature Point Extraction and Size Estimation by Clustering

Ischemic strokes due to pulmonary arteriovenous malformations: A systematic review.

Pulmonary arteriovenous malformations (PAVMs) can cause acute ischemic strokes (AISs) through paradoxical embolism. The clinical and imaging features of AIS due to PAVMs have not been studied. We report a case and perform a systematic review of the clinical and imaging characteristics of patients with AIS due to PAVMs. This may provide clues to screen patients with AIS for PAVMs and treat them appropriately to prevent further strokes. MEDLINE, EMBASE, and Web of Science databases were searched from inception to October 2023. We included patients of any age with AIS attributed to PAVM. Studies without clinical data were excluded. Demographics, AIS characteristics (location and arterial territories), and PAVM characteristics (location, size, and treatment) were recorded. A 47-year-old female presented with acute vertigo and gait imbalance. Magnetic resonance imaging showed AIS in the right cerebellum. CT chest confirmed a PAVM in the right lower lobe. Endovascular coil closure was performed. We identified 102 patients from 96 records. The mean age was 47.4 ± 17 years (67% female). Seventy percent had single AIS and 30% had multiple. The location was anterior circulation in 50%, posterior in 37%, and both in 13%. The most common arterial territory was middle-cerebral (51%), followed by posterior-cerebral (25%). PAVMs were mostly single (78%) and in the lower lobes (66%). Thirty-three had hereditary hemorrhagic telangiectasia (HHT) (33%). PAVM-related strokes occur at a young age and may have a high propensity for multifocality and posterior circulation location. Patients with PAVMs and AIS should be screened for HHT and venous thromboses.

Nanotechnological Carriers in the Treatment of Cancer: A Review

Abstract: There is an urgent need of advanced techniques/technologies for the treatment of can-cer as it is becoming the major cause of mortality and morbidity worldwide. The improvement of the cancer drug delivery system has been made possible by the formation of novel nanomaterials and nanocarriers. The nanocarriers prevent rapid degradation of the drug and thereby deliver the drug to a specific tumor site at therapeutic concentrations, meanwhile reducing the adverse/side effects by avoiding the delivery of the drug to normal sites. The antitumor activity can be en-hanced by increasing the tumoral uptake of nanocarriers. By delivering the nanocarriers either by active or passive targeting, the tumoral uptake can be increased. The pharmacokinetics, pharma-codynamics, and safety profile of the drug are determined by structural and physical factors like size, charge, shape, and other surface characteristics, hence the design of the nanoparticles is an important factor. In the present review, the mechanism of cellular targeting, along with the differ-ent nanoparticles used in cancer therapy is discussed. Nanotechnology have gained huge ground due to improved diagnosis and treatment additionally saving the time and resources, which makes this technology to get more landscape for researchers/ oncologists.

Tuning Surface Adhesion Using Grayscale Electron-beam Lithography.

Surface texturing of manufactured products tailors their properties, such as friction, adhesion, biocompatibility, or fluid interactions. However, advancements in this area are largely the result of trial-and-effort testing and generally lack a science-guided framework for determining the surface topography that will optimize performance. The present investigation explores grayscale electron-beam lithography as a means to create multiscale surface patterns to control surface performance. Here, we created and characterized a set of surface textures on a silicon wafer; the textures were superpositions of sine waves of varying wavelengths and amplitudes. First, the multiscale topography of the patterned surface was characterized, using profilometry and atomic force microscopy, to understand its fidelity to the designed-in pattern. The results of this analysis demonstrated how grayscale lithography accurately controlled the lateral size of features but was less precise on the vertical height of the surface, and also introduced inherent roughness below the scale of patterning. Second, a micromechanical tester was used to characterize the adhesion of the surfaces with large-scale polished silicon spheres. The results showed that adhesion could be tailored, with significant contribution from all of the designed-in length scales of topography. The strength of adhesion did not correlate with conventional roughness parameters but could be accurately modeled using simple numerical integration. Taken together, this investigation demonstrates the promise and challenges of grayscale e-beam lithography with multiscale patterns as a method for the tailoring of surface performance.

Femtosecond laser-induced dewetting of sub-10-nm nanostructures on silicon in ambient air

To realize nanoscale manufacturing based on laser direct writing technology, objective lenses with high numerical apertures immersed in water or oil are necessary. The use of liquid medium restricts its application in semiconductors. Achieving nanoscale features on silicon by laser direct writing in a low refractive index medium has been a challenge. In this work, a microsphere assisted femtosecond laser far-field induced dewetting approach is proposed. A reduction in the full-width at half-maximum of the focused light spot is realized by modulating tightly focused light through microspheres and achieving a minimum feature size of 9 nm on silicon in ambient air with energy smaller than the ablation threshold. Theoretical analysis and numerical simulation of laser processing are performed based on a two-temperature model. Furthermore, we explored the potential of femtosecond laser-induced dewetting in nanolithography and demonstrated its ability to achieve an arbitrary structure on silicon. Our work enables laser-based far-field sub-10-nm feature etching on a large-scale, providing a novel avenue for nanoscale silicon manufacturing.

High-precision and Large-Scale Vat Photopolymerization Printing based on "Spatial-Pixel Integration Compensation" method

Vat photopolymerization (VPP) is widely known for its exceptional printing accuracy, but effectively controlling stitching errors to achieve high-precision, large-scale printing remains a significant challenge. This study introduces a novel compensation method, termed "Spatial-Pixel Integration Compensation" (SPIC), to address this key obstacle. SPIC combines Spatial Motion Compensation to initially control stitching errors between adjacent sub-images to be within 100 µm and Pixel Compensation for precise adjustments, further reducing stitching errors. Integrating SPIC with our high-precision printing system resulted in a remarkable reduction of stitching errors by a factor exceeding 40. Crucially, this method minimizes the stitching error between any two sub-images to be less than one pixel point, specifically below 4 µm. Notably, SPIC is the first method specifically focused on effectively controlling and reducing stitching errors to achieve large-scale printing while maintaining high precision. To validate the practical applicability of the SPIC method, we used SPIC to print both Zig-Zag and herringbone structures (HBS) and achieved high-precision large-scale manufacturing with dimensions of 44 mm × 33 mm. In the HBS structure, the minimum feature size was 14.2 µm, and the printing error was less than 1 µm. These printed structures were used as molds to fabricate proof-of-concept polydimethylsiloxane (PDMS) microfluidic chips, demonstrating the successful mixing of rhodamine B and ethanol within the microfluidic channels. Furthermore, SPIC was extended to the printing of complex three-dimensional (3D) Triple-Periodic Minimal Surface (TPMS) structures, successfully producing TPMS-Gyroid and TPMS-Diamond structures with a minimum feature size of 20 µm and a printing error below 1.5 µm. These results demonstrate that the SPIC algorithm effectively enables high-precision, large-scale printing. This work significantly advances the application of VPP technology in fields requiring complex, high-precision, and large-scale 3D structures and provides valuable insights for future research in high-precision and large-scale printing.

Patterned microsphere-lens projection lithography using an electrohydrodynamic-jet-printing-assisted assembly

Microlens arrays have been widely used in the fields of micro-optics and micro- and nanofabrication. Traditional preparation methods utilize commercial photoresists and thermosetting materials, thereby restricting the optical properties of microlenses. In recent years, significant advancements have been achieved in near-field super-resolution imaging by utilizing microspheres and forming arrays of microsphere lenses via self-assembly. However, self-assembly approaches lack flexibility in terms of pattern selection. This study proposes a method that utilizes electrohydrodynamic jet (E-jet) printing to code ultraviolet (UV)-curable adhesives and assist in the assembly of patterned microsphere-lens arrays. Simulation results demonstrate that the UV-curable adhesive has little impact on the optical properties of the microsphere lens. Moreover, the microsphere lens exhibits a superior imaging resolution compared with traditional microlenses. A projection-lithography system is developed to achieve an accurate alignment between the focal plane of the microsphere lenses and the plane of the photoresist, facilitating the fabrication of patterned nanostructures. The lithographic nanostructures have a minimum feature size of 850 nm. This method enables the fabrication of arrays of microsphere lenses with arbitrary patterns and presents an inexpensive and simple strategy for fabricating micro- and nanostructure arrays with submicrometer features.

Study on the safe distance of spatial intersecting tunnel cavern under ground shock

The vertical distance of intersection area is an important factor dominating the service performance of spatial intersecting cavern. To obtain the influence of vertical distance on the dynamic response of orthogonal spatial intersecting caverns under ground shock, the plastic region and peak particle velocity (PPV) distribution are investigated by numerical simulation. A finite-dynamic model is established to simulate the mechanical response of the deeply bureid structure subjected to coupled static and dynamic load, with an artifical boundary condition setting method. The results indicate that as the vertical distance decreases, the plastic region in the intersection area gradually merges, while the bolt support at the lower cavern vault effectively suppresses the destruction of the intersection area. The free surface of the lower cavern vault weakens the bottom support conditions of the upper cavern floor structure, resulting in higher PPV when vertical distance is smaller. Conversely, as vertical distance increases, isolation effect of upper cavern on ground shock weakens, leading to an increase and followed by a decrease in PPV at the lower cavern vault and straight wall. Morever, when vertical distance exceeds than 3 times the cavern characteristic size, the lower cavern exhibits dynamic response characteristics of deeply buried single-cavern. when vertical distance within 3 times, there is significant interaction between caverns with inverse relationship between dynamic axial stress on bolts in intersection area and PPV at lower cavern vault. It is recommended to use comprehensive criteria involving PPV and plastic region distribution to evaluate safety performance for spatial intersecting cavern.

Influence of inhomogeneous distribution of inflow equivalence ratio on oblique detonation morphology and characteristic

In this paper, numerical simulations using Euler equations coupled detailed chemical reaction model are performed to reveal the influence of inhomogeneous distribution of inflow equivalence ratio (ER) on the morphology and characteristic of oblique detonation in hydrogen/oxygen/argon mixtures. The purpose of this study is to better understand the key parameters’ variation law of oblique detonation flow field under practical flight conditions so as to guide the design of oblique detonation chamber. Within the scope of our simulations, the results show that the oblique detonation wave (ODW) can still be standing under a large ER gradient. The thermodynamic state and characteristic sizes of the flow field reach the maximum value around ER = 0.8. First, the ODW angle and the post-wave temperature/pressure increase with the homogeneous inflow ER. Then, the inhomogeneity of inflow ER is introduced by assuming a lateral linear distribution covering the whole inflow boundary. When the ER increases along the inflow boundary with ER = 0 at the wedge tip, the overall morphology of the ODW presents a concave structure. Inversely, the ODW is convex with ER = 0 at the top outlet. The morphology and characteristic sizes of ODW are determined by the mixture composition in front of the corresponding wave surface. The transition mode of ODW is mainly determined by the ER of the incoming flow in front of the induction region.

디지털 휴먼 캐릭터의 성격 특성과 안면 디자인의 관계 탐색

Due to the development of AI technology, the use of digital humans and their market value are on the rise. Accordingly, as an alternative approach to communication between digital humans and users and building brand image, the purpose of this study is to suggest design elements by applying the Enneagram, Carl Jung's personality types, and Sasang Constitution's personality characteristics to facial design. To this end, the connection between each personality theory and digital human facial design was identified. Alternative design elements were extracted by finding consistency between the nine personality types of the Enneagram, Carl Jung's four personality types, and the four personality traits of Sasang Constitution. There are four possible facial shapes: rectangular, inverted triangle, oval, and square. These are the criteria for facial proportions and include facial shape and overall facial features, specifically the size and protrusion of eyes, nose, mouth, and forehead, and facial features. The location of the central axis and the degree of sagging were specified. As a result of the study, the significance of this study was that it found consistency between each personality type used as an argument for this study and used this to suggest alternative design guidelines.

High-precision BaTiO3 piezoelectric ceramics via vat photopolymerization 3D printing

BaTiO3 ceramics with high precision and superior performance are fabricated by vat photopolymerization 3D printing technology. The curing behaviors and photosensitive mechanisms are systematically investigated. Through the optimization of printing parameters, BaTiO3 ceramics with a high relative density of 95 % and few defects are obtained. Notably, the sintered BaTiO3 ceramics exhibit impressive properties, including a high piezoelectric coefficient d33 of 201 pC/N and strong ferroelectric characteristics with a maximum polarization Pmax of 31.4 μC/cm2 and residual polarization Pr of 18.5 μC/cm2. More importantly, a series of complex BaTiO3 structures including the body-centered cubic lattice and triply periodic minimal surface (TPMS) structures are created perfectly with the feature size as fine as 75 μm. Compared with other reported BaTiO3 structures printed by vat photopolymerization and material extrusion technologies, this work realizes a much higher printing resolution. The excellent performance and high precision of these BaTiO3 ceramics make them great potential for practical applications in piezoelectric components.

Investigation of Ripple Formation on Surface of Silicon by Low-Energy Gallium Ion Bombardment.

Regular wave patterns were created by a 2 kV gallium ion on Si(111) monocrystals at incidence angles between 60° and 80° with respect to the surface normal. The characteristic wavelength and surface roughness of the structured surfaces were determined to be between 35-75 nm and 0.5-2.5 nm. The local slope distribution of the created periodic structures was also studied. These topography results were compared with the predictions of the Bradley-Harper model. The amorphised surface layers were investigated by a spectroscopic ellipsometer. According to the results, the amorphised thicknesses were changed in the range of 8 nm to 4 nm as a function of ion incidence angles. The reflectance of the structured surfaces was simulated using ellipsometric results and measured with a reflectometer. Based on the spectra, a controlled modification of reflectance within 45% and 50% can be achieved on Si(111) at 460 nm wavelength. According to the measured results, the characteristic sizes (periodicity and amplitude) and optical property of silicon can be fine-tuned by low-energy focused ion irradiation at the given interval of incidence angles.

A New Silicon Mold Process for Polydimethylsiloxane Microchannels.

As an alternative to SU-8 soft lithography, a new silicon mold process of fabricating PDMS microchannel chips was proposed. A picosecond laser is used to cut through a 550 μm thick silicon wafer and generate the original microchannel pattern with a 50 μm minimum feature size. This single-crystal silicon pattern, with the edge debris caused by laser cutting being trimmed off by a KOH solution and with the protection field oxide layer being removed by BOE afterwards, firmly resided on a glass substrate through the anodic bonding technique. Four-inch wafers with microchannel patterns as the PDMS mold cores were successfully bonded on Pyrex 7740 or Eagle XG glass substrates for the follow-up PDMS molding/demolding process. This new maskless process does not need a photolithography facility, but the laser cutting service must be provided by professional off-campus companies. One PDMS microchannel chip for particle separation was shown as an example of what can be achieved when using this new process.