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Additive manufacturing methods 1 – 4 using static and mobile robots are being developed for both on-site construction 5 – 8 and off-site prefabrication 9 , 10 . Here we introduce a method of additive manufacturing, referred to as aerial additive manufacturing (Aerial-AM), that utilizes a team of aerial robots inspired by natural builders 11 such as wasps who use collective building methods 12 , 13 . We present a scalable multi-robot three-dimensional (3D) printing and path-planning framework that enables robot tasks and population size to be adapted to variations in print geometry throughout a building mission. The multi-robot manufacturing framework allows for autonomous three-dimensional printing under human supervision, real-time assessment of printed geometry and robot behavioural adaptation. To validate autonomous Aerial-AM based on the framework, we develop BuilDrones for depositing materials during flight and ScanDrones for measuring the print quality, and integrate a generic real-time model-predictive-control scheme with the Aerial-AM robots. In addition, we integrate a dynamically self-aligning delta manipulator with the BuilDrone to further improve the manufacturing accuracy to five millimetres for printing geometry with precise trajectory requirements, and develop four cementitious–polymeric composite mixtures suitable for continuous material deposition. We demonstrate proof-of-concept prints including a cylinder 2.05 metres high consisting of 72 layers of a rapid-curing insulation foam material and a cylinder 0.18 metres high consisting of 28 layers of structural pseudoplastic cementitious material, a light-trail virtual print of a dome-like geometry, and multi-robot simulations. Aerial-AM allows manufacturing in-flight and offers future possibilities for building in unbounded, at-height or hard-to-access locations. An additive manufacturing method using a team of autonomous aerial robots allows for scalable and adaptable three-dimensional printing, and is used to deposit building materials during flight.

Polymers play a significant role in enhanced oil recovery (EOR) due to their viscoelastic properties and macromolecular structure. Herein, the mechanisms of the application of polymeric materials for enhanced oil recovery are elucidated. Subsequently, the polymer types used for EOR, namely synthetic polymers and natural polymers (biopolymers), and their properties are discussed. Moreover, the numerous applications for EOR such as polymer flooding, polymer foam flooding, alkali–polymer flooding, surfactant–polymer flooding, alkali–surfactant–polymer flooding, and polymeric nanofluid flooding are appraised and evaluated. Most of the polymers exhibit pseudoplastic behavior in the presence of shear forces. The biopolymers exhibit better salt tolerance and thermal stability but are susceptible to plugging and biodegradation. As for associative synthetic polyacrylamide, several complexities are involved in unlocking its full potential. Hence, hydrolyzed polyacrylamide remains the most coveted polymer for field application of polymer floods. Finally, alkali–surfactant–polymer flooding shows good efficiency at pilot and field scales, while a recently devised polymeric nanofluid shows good potential for field application of polymer flooding for EOR.

In this article, an investigation is conducted to study the precise role of zirconium nanoparticles that exist in a slime-like fluid subject to specific adjustments. Since gliding is a technique of mobility used by bacteria that lack motility components, bacteria travel on their own strength in gliding locomotion by secreting a layer of slime on the substrate. A model of an undulating sheet over a layer of slime of a Rabinowitsch fluid is investigated as a potential model of bacteria’s gliding motility. With the aid of long wavelength approximation, the equations governing the circulation of slime underneath the cells are established and analytically solved. The effects of pseudoplasticity, dilatation and non-Newtonian parameter on the behavior of zirconium concentration, speed of microorganism (bacteria), streamline patterns, and pressure rise for non-Newtonian and Newtonian fluids are compared. The power required for propulsion is also investigated. Physical interpretation for the pertinent variables has been graphically discussed against the parameters under consideration. It is found that with the increase in the concentration of zirconium nanoparticles, the bacterial flow is accelerated and attains its maximum near the rigid substrate wall while an opposite behavior is noticed in the rest region.

This paper conducts a study on the adaptability of polymer flooding under high salinity conditions (25,000 mg/L) for a chemical flooding target block — a multi-layered sandstone reservoir with active bottom water and significant differences in vertical permeability. The main oil-producing layers of the study area, AB 13 and AB2-3, have a small permeability difference and a high degree of oil extraction, and are unaffected by bottom water, providing favorable conditions for the application of polymer flooding technology. Based on the screening and evaluation of more than ten types of salt-resistant polymers, the best polymer flooding system formula was optimized through physical simulation experiments. The experimental results show that the molecular cluster size analysis indicates that HDP3 and GY polymers have larger molecular cluster sizes (greater than 500 nm), while the sizes of other polymers range between 40 nm and 300 nm. In terms of viscosity, KY51, HDP3, ZC10, GY, KY08, and 5115 polymers can achieve an increased viscosity effect of 20 mPa·s at relatively low concentrations. The power law index of the polymer solutions is less than 1, indicating that they are pseudoplastic fluids, and the magnitude of the consistency coefficient directly affects the overall viscosity enhancement capability of the liquid. Stability experiments found that as the concentration increases, the viscosity retention rate of the polymer solution decreases, with ZC10 polymer demonstrating the best aging stability. In terms of polymer flooding performance, KY51 polymer shows the strongest oil displacement capability, with an overall polymer flooding recovery rate of 14.58%, and the numerical model prediction for the chemical flooding target block suggests that polymer flooding can increase the recovery rate by 11.7 percentage points. This study provides a theoretical basis for polymer flooding technology in high salinity oil reservoirs..

Three-dimensional printing could be used to create complex and multifunctional soft electronic devices. However, printing solid-state elastic conductors with three-dimensional geometries is challenging because the rheological properties of existing inks typically only allow for layer-wise deposition. Here we show that an emulsion system—consisting of a conductive elastomer composite, immiscible solvent and emulsifying solvent—can be used for the omnidirectional printing of elastic conductors. The viscoelastic properties of the composite provide structural integrity to the printed features—allowing freestanding, filamentary and out-of-plane three-dimensional geometries to be directly written—and pseudo-plastic and lubrication behaviours that provide printing stability and prevent nozzle clogging. Printed structures of the intrinsically stretchable conductor exhibit a minimum feature size less than 100 μm and stretchability of more than 150%. The vapourisation of the dispersed solvent phase in the emulsion results in the formation of microstructured, surface-localized conductive networks, which improve the electrical conductivity. To illustrate the capabilities of our approach, we create a skin-mountable temperature sensor with a matrix-type stretchable display based on omnidirectionally printed elastic interconnects. Freestanding, out-of-plane structures made of stretchable conductors can be printed using an emulsion-based ink that has the viscoelasticity to be extruded into three-dimensional geometries and supporting its own shape.

This work aimed to produce six distinct ice creams: IC: control ice cream (without any probiotic or persimmon puree), ICP: ice cream with 20% persimmon puree, PIC: probiotic ice cream, FIC: fermented ice cream, ICFP: ice cream with 20% fermented persimmon puree, FICP: co-fermented ice cream with 20% persimmon puree. Lacticaseibacillus rhamnosus GG was used as the probiotic and fermentation agent. The addition of persimmon puree, probiotic inoculation and fermentation resulted in a reduction in the total dry matter content of the ice cream (P ? 0.05). Co-fermentation led to a notable reduction in the pH value, with the lowest pH observed in the FICP ice cream sample at 5.33 (P ? 0.05). The addition of persimmon puree resulted in a decrease in the L? values and an increase in both the a? and b? values of the ice cream samples. All ice cream samples exhibited pseudoplastic flow, and fermentation, persimmon puree addition and probiotic inoculation resulted in a reduction in K and hardness values. Co-fermentation had a protective effect on probiotic viability, with approximately 8.95 ± 0.01 log CFU g-1 of probiotic viability detected in the FICP ice cream sample after 120 days of storage. Furthermore, co-fermentation markedly enhanced the bioactive characteristics of the samples, with the FICP sample exhibiting the highest TPC, CUPRAC, and DPPH values (242.57 ± 11.52mg GAE 100g-1, 22.95 ± 0.29mg TE 100g-1, and 48.02 ± 3.27%, respectively). The study demonstrated that persimmon can be employed in the production of ice cream, with the co-fermentation of the ice cream mix promoting the viability of probiotics and enhancing the bioactive characteristics of the ice cream samples.

This study presents a novel phase-field model for ductile fracture by the introduction of both the plastic driving force and the degrading fracture toughness into crack phase-field computations based on the phenomenological justification for ductile fracture in elastoplastic materials. Assuming that the constitutive work density consists of elastic, pseudo-plastic and crack components, we derive the governing equations from local and global optimization problems within the continuum thermodynamics framework. In addition to the elastic strain energy, the plastic strain energy also works as a driving force to sustain damage evolution. Additionally, we introduce a degrading fracture toughness to reflect the evolution of micro-defects and their coalescences into each other that are caused by accumulated plastic deformation. Equipped with these ingredients, the proposed model realizes the reduction of both stiffness and fracture toughness to simulate the failure phenomena of elastoplastic materials. Several numerical examples are presented to demonstrate the capability of the proposed model in reproducing some typical ductile fracture behaviors. The findings and perspectives are subsequently summarized.

In this article, a Riga plate is exhibited with an electric magnetization actuator consisting of permanent magnets and electrodes assembled alternatively. This exhibition produces electromagnetic hydrodynamic phenomena over a fluid flow. A new study model is formed with the Sutterby nanofluid flow through the Riga plate, which is crucial to the structure of several industrial and entering advancements, including thermal nuclear reactors, flow metres and nuclear reactor design. This article addresses the entropy analysis of Sutterby nanofluid flow over the Riga plate. The Cattaneo–Christov heat and mass flux were used to examine the behaviour of heat and mass relaxation time. The bioconvective motile microorganisms and nanoparticles are taken into consideration. The system of equations for the current flow problems is converted from a highly non-linear partial system to an ordinary system through an appropriate transformation. The effect of the obtained variables on velocity, temperature, concentration and motile microorganism distributions are elaborated through the plots in detail. Further, the velocity distribution is enhanced for a greater Deborah number value and it is reduced for a higher Reynolds number for the two cases of pseudoplastic and dilatant flows. Microorganism distribution decreases with the increased magnitude of Peclet number, Bioconvection Lewis number and microorganism concentration difference number. Two types of graphical outputs are presented for the Sutterby fluid parameter (β = −2.5, β = 2.5). Finally, the validation of the present model is achieved with the previously available literature.

A formulation strategy based on the alkyl polyglucoside (APG) surfactant Triton CG‐110, in combination with 1‐Dodecanol as a co‐surfactant and brine as an additive, is developed. The results highlight the pivotal role of brine in modulating the rheological properties of the system, inducing a shift from viscous to viscoelastic and yield‐pseudoplastic behavior at elevated surfactant and salt concentrations. Small‐angle X‐ray scattering analysis reveals that increased salinity enhances interparticle correlations within bicellar nanostructures, which are closely associated with improved viscoelasticity and formulation stability. The salting‐out effect, combined with the ability to incorporate 1‐Dodecanol, leads to nanoscale structural transitions that provide a rational basis for tuning the performance of surfactant systems. The resulting high oil‐uptake efficiency of 82% in the final formulation demonstrates a viable pathway toward high‐efficiency, environmentally benign surfactants, supporting the broader transition to greener chemistries in industrial applications. Salt's effect on the APG:1‐Dodecanol system was studied. Small‐angle X‐ray scattering showed salt increased interparticle correlation, leading to higher structural organization at higher salt concentrations. This correlates with observed viscoelastic properties. Cleaning efficiency tests were also conducted on samples.

Natural hydrogels are widely used for 3D-bioprinting because of their qualities for tissue engineering. Recently, hydrogels have been combined with bioactive glasses, due to their angiogenic properties that aid tissue regeneration. In this work, we studied the printability and the rheological properties of gelatin–alginate–hyaluronic acid inks with 2–8% wt of 45S5 bioglass (BG) that followed a pseudoplastic behavior along the 3D-printing process. The reduction in the storage modulus of the inks after adding BG indicates that the microparticles might disrupt the polymeric network; furthermore, a reduction in the viscosity was determined at BG concentrations above 6%. Inks without BG or up to 2% evidenced the best printing fidelity on 10% infill scaffolds. The tensile modulus of crosslinked 40%-filled scaffolds increased from 130 kPa (without BG) to 160 kPa (6–8% BG). Moreover, a hydroxyapatite layer appeared in scaffolds containing BG 6% and 8% wt after being cultured for 2 days. Attachment and growth of fibroblasts on the scaffolds revealed their cytocompatibility, making these materials an alternative for further research on soft tissues regeneration.