Final Shape Research Articles

Probing wrapping dynamics of spherical nanoparticles by 3D vesicles using force-based simulations.

Nanoparticles present in various environments can interact with living organisms, potentially leading to deleterious effects. Understanding how these nanoparticles interact with cell membranes is crucial for rational assessment of their impact on diverse biological processes. While previous research has explored particle-membrane interactions, the dynamic processes of particle wrapping by fluid vesicles remain incompletely understood. In this study, we introduce a force-based, continuum-scale model utilizing triangulated mesh representation and discrete differential geometry to investigate particle-vesicle interaction dynamics. Our model captures the transformation of vesicle shape and nanoparticle wrapping by calculating the forces arising from membrane bending energy and particle adhesion energy. Inspired by cell phagocytosis of large particles, we focus on establishing a quantitative understanding of large-scale vesicle deformation induced by the interaction with particles of comparable sizes. We first examine the interactions between spherical vesicles and individual nanospheres, both externally and internally, and quantify energy landscapes across different wrapping fractions of the nanoparticles. Furthermore, we explore multiple particle interactions with biologically relevant fluid vesicles with nonspherical shapes. Our study reveals that initial particle positions and interaction sequences are critical in determining the final equilibrium shapes of the vesicle-particle complexes in these interactions. These findings emphasize the importance of nanoparticle positioning and wrapping fractions in the dynamics of particle-vesicle interactions, providing crucial insights for future research in the field.

In-line measuring and feature similarity-based group and pairing assembly for metallic BPPs

Assembly of proton exchange membrane (PEM) fuel cell stacks with metallic bipolar plates (BPPs) is a process of high precision stacking for hundreds of individual sheet components. The accuracy of stacking process and the uniformity of contact status for layers effect the working efficiency of the stack. The manufacturing of metallic BPPs consists of several processes including pressing, welding and coating, in which each process will have an impact on the final shape of BPPs. Especially for large-scale metallic BPPs, which are critical parts for manufacturing high power fuel cell stack, the shape deviation will be magnified. In this research, a batch of normal size metallic BPPs are investigated as preliminary study for large-scale BPPs. They are measured by a 3D laser scanner and their geometric deviation are analyzed. An approach of in-line measuring integrated automatic assembly line for BPPs and a method of feature similarity-based group and pairing assembly are proposed with which the uncertainty of stacking result with random placing order of fuel cell components is expected to be reduced without changing previous manufacturing processes. The scanned features are compared to the nominal model of BPP and then fitted into surfaces to visualize the individual deviations. K-medoids algorithm is used to cluster these BPPs into groups. The result shows feasibility of applying this method to large-scale BPPs in future work.

WOMEN IN LAW FROM THE LAW & EMOTIONS PERSPECTIVE. CASE STUDY OF THE INFERTILITY TREATMENT ACT

The status of women in law (and not only theirs) is linked to social and cultural perceptions of women’s desirable behavior. Going against well-established patterns is not indifferent in both legal and social terms. One of the primary contexts of ‘femininity’ in the law is close relationships, in which women are viewed through the ‘role’ of a mother and wife. The purpose of this paper is to determine how the cultural script of romantic love and the emotions associated with it affect perceptions of women in close relationships, such as marriage and parenthood. It assumes that the emotions of participants in legal discourse – dogmatists and those involved in the law-making process – influence the final shape of legal regulations. The cultural script that influences how women are perceived in law is romantic love. To illustrate the issue, the case study of the Infertility Treatment Act is presented in this article. This case shows that from a legal perspective, a woman is seen in indivisible roles in a close relationship of a wife (partner) and mother.

Образ духа-хозяйки земли в эпосе олонхо. Часть 3: Путь эволюции

The article focuses on analyzing how the image of the spirit-mistress of the earth has evolved over time. The study has revealed that the image was created by combining elements from various historical periods. The oldest stratum leads us to the image of the ancient Stone Age civilization, with its polyfunctional and multicomponent nature reflecting the syncretic worldview of ancient people who endowed it with astral, vegetative, and chthonic features. The Neolithic image of perception is associated with the first “offshoots” of functions from a single prototype. Subsequently, genetically related images of the spirits of forest, hunting, vegetative forces, fire, childbearing, and cattle litter appeared. A higher level of abstraction was characterized by the images of wisdom and mind, the creative principle, and the thunderer. The image under study demonstrates the stability of its function as a patronage of the fruit-bearing forces of nature, dating back to ancient times. During the Bronze Age, the prototype was enriched with the new idea of the reincarnation cycle of the human soul and the pathos of immortality. The patriarchy promoted the emergence of male images of spirits-masters of the earth later to be assigned the role of innovative “cultural creations” in the bosom of the earth. The final shape of the anthropomorphic image of the mistress of the earth was formed only in the early twentieth century due to the widespread collectivization in the USSR.

Developing Rapid Metal AM deformations Prediction using CNN

The production of complex 3D components using Metal Additive Manufacturing requires several steps combining different expertise, such as product design, process planning and manufacturing. This process chain would benefit significantly from faster deformation predictions enabling quicker iteration during parts design and manufacture, such as to evaluate or validate quickly a component expected final shape, internal stresses or deformation occurring during printing. This paper presents a new data-driven approach based on deep learning that can speed up the prediction of parts’ geometrical deformations by creating a digital twin of an FEA simulation. A new CNN model founded on MeshCNN and designed for the processing of AM 3D models is described and methods for testing learning capabilities using training data generated by the FEA based software Simufact Additive are proposed.

OPTIMIZATION OF ACCURACY AND SURFACE ROUGHNESS OF 3D SLA PRINTED MATERIALS WITH RESPONSE SURFACE METHOD

3D printers are used frequently for rapid prototyping and production. SLA (stereolithographic) printers, widely used in areas requiring precision production, form the final shape by solidifying the liquid resin with UV rays. In SLA printing, the final figure is created by changing many printing parameters. For this reason, surface integrity and precision of measurements vary. Dimensional accuracy (DA) and surface roughness (SR) outputs should be investigated for precise printing. Therefore, the effects on SR and DA output parameters were investigated by changing the layer height, exposure time, and lift input parameters with the Response Surface Method (RSM). The effective parameters for both outputs are layer height and lift. As the layer height and lift increased, the SR and DA values of the printed parts increased. The predicted results calculated with the regression equations and the experimental results were quite close. Optimum input parameters were found by multi-response optimization. Accordingly, the 8th experiment, 0.05mm-4s-1.5mm, was the best parameter. The difference between the predicted and experimental values for multi-response optimization was 4.28% for SR and 0.27% for DA. Thus, effective parameters for SR and DA have been determined for precision production in SLA printers.

Laparoscopic Sleeve Gastrectomy Lacks Intrasurgeon and Intersurgeon Agreement in Technical Key Points That May Affect Gastroesophageal Reflux Disease After the Procedure.

Gastroesophageal reflux disease (GERD) after sleeve gastrectomy (SG) may be related to surgical technique. The fact that there is a lack of technical standardization may explain large differences in GERD incidence. The aim of this study is to evaluate auto- and hetero-agreement for SG technical key points based on recorded videos. Ten experienced (minimum of 5years performing bariatric surgery, minimum of 30 SG per year) bariatric surgeons (9 (90%) males) were selected. Participants were invited to send an unedited video with a typical laparoscopic SG (first round of the Delphi process). Videos were cropped into small clips comprising 11 key points of the technique. All anonymized clips (including their own) were returned to all surgeons. Individuals were asked to agree or not with the technique demonstrated (second round). The percentage of agreement was presented to the entire group that was asked for a second vote (third round). Agreement was poor/fair for all points except hiatal repair that had a very good agreement in the second round. For the third round, there was a slight increase in agreement for distance esophagogastric junction/proximal stapling and gastric mobilization for stapling and a slight decrease in agreement for gastric tube final shape. Only 1 (10%) surgeon recognized that he evaluated his own video. Five (50%) surgeons disagreed with themselves on 1 or more points. SG lacks intrasurgeon and intersurgeon agreement in technical key points that may justify significant differences in GERD incidence after the procedure.

The role of viscoplastic drop shape in impact

The impact of fluid drops on solid substrates is a cardinal fluid dynamics phenomenon intrinsically related to many fields. Although these impacting objects are very often non-spherical and non-Newtonian, previous studies have mainly focused on spherical Newtonian drops. As a result, both shape and rheological effects on the drop-spreading dynamics remain largely unexplored. In the present work we use a mixed approach combining experiments with multiphase three-dimensional numerical simulations to extend the work reported by Luu & Forterre (J. Fluid Mech., vol. 632, 2009, pp. 301–327) by highlighting the fundamental role of shape in the normal impact of viscoplastic drops. Such complex fluids are highly common in various industrial domains and ideally behave either like a rigid body or a shear-rate-dependent liquid, according to the stress solicitation. Spherical, prolate, cylindrical and prismatic drops are considered. The results show that, under negligible capillary effects, the impacting kinetic energy of the drop is dissipated through viscoplastic effects during the spreading process, giving rise to three flow regimes: (i) inertio-viscous, (ii) inertio-plastic, and (iii) mixed inertio-visco-plastic. These regimes are deeply affected by the drop initial aspect ratio, which in turn reveals the possibility of using drop shape to control spreading. The physical mechanisms driving the considered phenomenon are underlined by energy budget analyses and scaling laws. The results are summarised in a two-dimensional diagram linking the drop maximum spreading, minimum height and final shape with different spreading regimes through a single dimensionless parameter, here called the impact number.

Biomedical Applications of Titanium Alloys: A Comprehensive Review.

Titanium alloys have emerged as the most successful metallic material to ever be applied in the field of biomedical engineering. This comprehensive review covers the history of titanium in medicine, the properties of titanium and its alloys, the production technologies used to produce biomedical implants, and the most common uses for titanium and its alloys, ranging from orthopedic implants to dental prosthetics and cardiovascular devices. At the core of this success lies the combination of machinability, mechanical strength, biocompatibility, and corrosion resistance. This unique combination of useful traits has positioned titanium alloys as an indispensable material for biomedical engineering applications, enabling safer, more durable, and more efficient treatments for patients affected by various kinds of pathologies. This review takes an in-depth journey into the inherent properties that define titanium alloys and which of them are advantageous for biomedical use. It explores their production techniques and the fabrication methodologies that are utilized to machine them into their final shape. The biomedical applications of titanium alloys are then categorized and described in detail, focusing on which specific advantages titanium alloys are present when compared to other materials. This review not only captures the current state of the art, but also explores the future possibilities and limitations of titanium alloys applied in the biomedical field.

Analysis of Lightweight Structure Mesh Topology of Geodesic Domes

This paper presents two methods of shaping the mesh topology of lightweight structures as spherical domes. The two given methods of dividing the initial face of the polyhedra determine the obtained structures, which differ in the way of connecting the nodal points. These points were obtained by applying the algorithm for calculating spherical coordinates presented in the paper, which were then converted to the Cartesian system using transformation formulas. Two models of dome structures are presented, based on a 4608-hedron according to the first division method, and on a 4704-hedron, using the second proposed method with numerical analysis. Thus, the novelty of this paper is an implementation of the formulas and algorithms from geodesic domes based on the regular dodecahedron to the regular octahedron, which has not been presented so far. The choice of the shape of the structure has impacts on sustainable development, dictated by structural and visual considerations, leading to the design of a light structure with low consumption of construction material (steel), which can undoubtedly be helpful when making the final structure shape. In addition, according to this research, it can be concluded that using the first method to create a geodesic dome mesh is more straightforward, safer, and requires less design experience.

ПЕРСПЕКТИВИ РОЗВИТКУ ВОДНЕВОЇ ЕНЕРГЕТИКИ З МОЖЛИВІСТЮ ВІДНОВЛЕННЯ МЕМБРАН ДЛЯ ПАЛИВНИХ ЕЛЕМЕНТІВ ПІСЛЯ КОНТАКТУ З ВОДНЕМ

The prospects for the development of hydrogen energy and the influence of temperature on the change in the shape of the membrane for fuel cells in contact with hydrogen have been studied. It has been confirmed that the change in the shape of the plate from the α-PdHn gradient alloy develops in two stages. The experimental regularities of the change in the shape of the palladium membrane during operation in a hydrogen environment were investigated. It was determined that upon contact with hydrogen, a temporary gradient material "metal-hydrogen" is formed in the membrane, which causes the development of hydrogen concentration stresses, and the maximum change in the shape of the membrane, which occurs at a constant temperature, depends on the diffusion coefficient and the equilibrium solubility of hydrogen in palladium. However, when the temperature changes, the diffusion coefficient of hydrogen in palladium and the equilibrium concentration of hydrogen in palladium also change, which affects the temperature dependence of the final shape change of the membrane. This fact makes it possible to effectively plan and determine the time of hydrogen penetration into the membrane, control the change of shape and adjust the operating modes of the fuel cell. It is the equilibrium solubility of hydrogen in palladium and its diffusion coefficient when the temperature changes in the main that determine the maximum and final change in the shape of the membrane, and the temperature determines the fluctuation of the change in the shape of the membrane when the temperature of the hydrogen flow entering the chamber changes. Thus, the complete return of the membrane to its initial state at increased temperature clearly indicates the implementation of a coherent membrane bending mechanism. Upon completion of hydrogen saturation by the coherent mechanism under the conditions of reaching equilibrium with the gas phase, the original palladium membrane turns out to be transformed into a membrane of the equilibrium alloy α-PdHnо, which inherits the initial state of a pure palladium membrane. Therefore, to model the hydrogen penetration process in the fuel cell, it is necessary to know the gas flow rate, membrane permeability and gas temperature, as well as the diagram of the fuel cell where these processes take place. At the same time, scientists still hope for the future development of hydrogen energy, despite the existing difficulties. This requires additional research and development of new technologies to remove obstacles to the transition to hydrogen as a primary energy source

Analysis of the flange turning of aluminium aerosol cans based on tool edge geometry

In recent years, the cosmetics industry, as the largest user of aerosol packaging, has been growing at an accelerating pace, requiring the production of aerosol cans with an increasing number of design elements. In the production of aluminium aerosol cans, the final shape is formed in several steps from a disc-shaped blank by back-rolling, and a so-called flange cutting (turning) operation is usually carried out after the flange of the can has been formed. Experience has shown that this operation often results in difficult-to-handle flowing chips, which in some cases can lead to a poor-quality product. In this paper, the material and edge geometry of the insert bit used in the flange turning operation are investigated and edge geometry modification recommendations are made to avoid unfavourable machining conditions.

In-mold condition-centered and explainable artificial intelligence-based (IMC-XAI) process optimization for injection molding

This paper proposes a novel injection molding process optimization method based on the in-mold condition (IMC) and interpreted influence of in-mold condition features on part quality. In-mold condition is crucial for process optimization because it represents the actual process condition in the cavity where the polymer material is formed into the final part shape. Traditionally, the analysis of in-mold condition heavily depends on domain knowledge and insight, which introduces bias and inconsistency in in-mold condition-based process optimization. This study aims at developing an intelligent, objective, and robust process optimization method that concentrates on the highly influential in-mold condition features concerning part-quality, as interpreted by explainable artificial intelligence (XAI). In this in-mold condition-centered modeling approach, the input process parameters and final part quality were associated with the in-mold condition, with their corresponding relationship modeled by two machine learning (ML) models, respectively. The effect of in-mold condition on part quality was interpreted by applying XAI on the ML model that describes the relationship between in-mold condition and part quality. Features in the in-mold condition profiles that have high influence on part quality are given more weight in the search for diverse in-mold conditions that satisfy multiple part-quality objectives. A feasibility check has been implemented to identify, among those potential in-mold conditions, the optimal one that is physically feasible based on the ML model that governs the relationship between the process parameters and in-mold condition. The proposed method not only pinpoints better optimized process parameters than the conventional approach that omits the in-mold condition and only considers the direct relationship between the process parameters and part quality, but also reveals the possibility of further quality improvement. The optimization tool of the proposed method can be found on an online interactive platform https://imc-xai-injmold-optimization-4e26a3e3ef41.herokuapp.com/, which was created to facilitate further research based on the proposed approach. In addition to process optimization, this approach can effectively contribute to intelligent manufacturing management and Industry 4.0.

Capillary Forces Lead to Pendant Crystals at the Liquid-Air Interface of Evaporating Salt Solutions.

We investigated the nucleation and growth processes of individual NaCl crystals from an evaporating salt solution that is supersaturated. We find that crystals nucleate at the liquid/vapor interface, resulting in distinct "pendant" crystals, which reach millimeter dimensions. The substantial size of the crystals induces deformation of the interface. This process and the evaporation rate, in turn, determine the final crystal shape, which features a deep central cavity. Our findings reveal that a delicate balance exists between gravity, buoyancy, and the surface tension of the liquid/vapor interface that allows the crystal to remain pendant. When the contact angle of the crystal with the meniscus reaches 90°, the crystal disconnects from the interface and falls into the solution. We quantitatively predict the critical mass at which this occurs.

Material‐minimised construction with extruded textile reinforced concrete

AbstractThe use of textile reinforced concrete (TRC) is particularly suitable for producing sustainable, material‐minimised components, as it allows for a significant reduction in the amount of concrete cover required compared to steel reinforced concrete (SRC). Instead of steel, fibres made of glass, aramid or carbon are used as reinforcement, which are processed from rovings into textiles with a polymer or mineral impregnation. Among these, carbon reinforcements have the highest tensile strength and alkali resistance, making them the most durable in concrete and requiring less maintenance over time. An innovative approach is the production of TRC structures by means of extrusion, in which the stiff, fresh concrete is continuously pressed through a shaping mouthpiece, giving the product its final shape. Within the scope of the CRC/Transregio 280, a new mouthpiece was developed that enables the horizontal introduction of stiff, impregnated textiles. The carbon TRC produced in this process showed a textile stress of up to 4,000 MPa. Additionally, solutions are presented that allow the characterization of stiff, fresh concrete and technical limits for shaping fresh, extruded TRC elements. The potential of this new production method is illustrated through the example of a compound component made of extruded TRC elements.

Asymptotic Modeling of Optical Fibres: Annular Capillaries and Microstructured Optical Fibres

Microstructured optical fibres (MOFs) are a new type of optical fibres that possess a wide range of optical properties and many advantages over common optical fibres. Those are provided by unique structures defined by a pattern of periodic or quasi-periodic arrangement of air holes that run through the fibre length. In recent years, MOFs have opened up new possibilities in the field of optics and photonics, enabling the development of advanced devices and novel optical systems for different applications. The key application areas of MOFs vary from telecommunications and high-power energy transmission to quantum optics and sensing. The stack-and-draw method is a standard manufacturing technique for MOFs, where a preform is first manually created and then drawn in a sophisticated furnace into a fibre with the required final dimensions and position of the air holes. During the manufacturing process, experimenters can control only a few parameters, and mathematical models and numerical simulations of the drawing process are highly requested. They not only allow to deepen the understanding of physical phenomena occurring during the drawing process, but they also accurately predict the final cross-section shape and size of the fibre. In this manuscript, we assume thermal equilibrium between the furnace and the fibre and propose a functional form of the fibre temperature distribution. We utilise it with asymptotic mass, momentum, and evolution equations for free surfaces already available in the literature to describe the process of fibre drawing. By doing so, the complex heat exchange problem between the fibre and the furnace need not be solved. The numerical results of the whole asymptotic model overall agree well with experimental data available in the literature, both for the case of annular capillaries and for the case of holey fibres.

Revealing the Formation Dynamics of Janus Polymer Particles: Insights from Experiments and Molecular Dynamics.

Seeded emulsion polymerization is one of the best-known methods for preparing polymer particles with a controlled size, composition, and shape. It first requires the preparation of seed particles, which are then swollen with additional monomer (the same as the one used for the seed or a different one), to either increase the seed's size or change its morphology. The use of surfactants plays a central role in guaranteeing the required colloidal stability and contributing to the final shape and structure of the particles by lowering the interfacial energy between the polymer of the seed and the added monomer. We here study the polymerization of methyl methacrylate in the presence of polystyrene seed particles at various surfactant concentrations in the presence and absence of a surfactant (sodium dodecyl sulfate). We first show experimentally that the morphology of the colloidal particles can be tuned from Janus to core-shell, depending on the presence or absence of surfactant on the seeds particles' surface. Furthermore, using classical molecular dynamics simulations, we investigate the mechanism and behavior of the surfactants during the first stages of the polymerization process. We use a newly developed approach based on contact statistical analysis to confirm the critical role played by the organization of surfactant molecules on the surface of the seed particles in dictating the final particle morphology.

On geometric shape construction via growth operations

We study algorithmic growth processes under a geometric setting. Each process begins with an initial shape of nodes SI=S0 and, in every time step t≥1, by applying (in parallel) one or more growth operations of a specific type to the current shape, St−1, generates the next, St, always satisfying |St|>|St−1|. We define three types of growth operations and explore the algorithmic and structural properties of their resulting processes. Our goal is to characterize the classes of shapes that can be constructed in O(log⁡n) or polylog n time steps, n being the size of the final shape SF. Moreover, we want to determine whether a given shape SF can be constructed from a given initial shape SI using a finite sequence of growth operations of a given type, called a constructor ofSF. We give exact and partial characterizations of classes of shapes that can be constructed in polylog n time steps, polynomial-time centralized algorithms for deciding reachability between pairs of input shapes (SI,SF) and for generating constructors when SF can be constructed from SI, as well as some negative results.

Development of Shape Prediction Model of Microlens Fabricated via Diffuser-Assisted Photolithography.

The fabrication of microlens arrays (MLAs) using diffuser-assisted photolithography (DPL) has garnered substantial recent interest owing to the exceptional capabilities of DPL in adjusting the size and shape, achieving high fill factors, enhancing productivity, and ensuring excellent reproducibility. The inherent unpredictability of light interactions within the diffuser poses challenges in accurately forecasting the final shape and dimensions of microlenses in the DPL process. Herein, we introduce a comprehensive theoretical model to forecast microlens shapes in response to varying exposure doses within a DPL framework. We establish a robust MLA fabrication method aligned with conventional DPL techniques to enable precise shape modulation. By calibrating the exposure doses meticulously, we generate diverse MLA configurations, each with a distinct shape and size. Subsequently, by utilizing the experimentally acquired data encompassing parameters such as height, radius of curvature, and angles, we develop highly precise theoretical prediction models, achieving R-squared values exceeding 95%. The subsequent validation of our model encompasses the accurate prediction of microlens shapes under specific exposure doses. The verification results exhibit average error rates of approximately 2.328%, 7.45%, and 3.16% for the height, radius of curvature, and contact angle models, respectively, all of which were well below the 10% threshold.

Using Working Parameters to Control Formation and Shape of Lotus-Type Pores

The development and final shape of lotus-type pores can be manipulated in advance during unidirectional solidification in this study. Independent parameters considered are solidification rate, ambient pressure, and factor accounting for solute concentration at a selected reference state in liquid deviated from that at the top surface. Lotus-type porous materials have contemporarily been used in heat sinks, energy including shock, vibration, and sound absorption in aircraft engines, etc., which strongly depend on directions, distributions, and pore shapes in solid. This model accounts for transient gas pressure in the pore affected by solute transfer, gas, capillary and hydrostatic pressures, and Sieverts’ law or Henry’s law at the bubble cap and top surface. Solute transport across the cap self-consistently accounts for solute convection at the cap based on a reference concentration deviated from that at the top free surface, the amount of solute rejected by the solidification front into the pore, and the convection-affected concentration at the solidification front. The resulting simultaneous systems of unsteady first-order ordinary differential equations are solved by a MATLAB code. The length of lotus-type pores is also interpreted by the conservation of the solute content in the system. The predicted final shapes of lotus-type pores agree with algebraic results previously confirmed by available experimental data.