Search Results (4,700)

When examined at the nanometer length scale, metallic liquids exhibit extensive ordering. Bonding enthalpies are balanced against entropic tendencies resulting in a rich complicated behavior that leads to clustering that depends on temperature but evolves on picosecond time scales. The structural organization of metallic liquids affects their thermophysical properties, such as viscosity and density, thus influencing the ability of a metallic liquid to form useful technological phases, such as metallic glasses. The time-dependent pair correlation function (the Van Hove function) was determined for metallic-glass forming Cu₄₉Zr₄₅Al₆ at 1060 °C from time-of-flight inelastic neutron scattering measurements made using the Neutron Electrostatic Levitation facility at the Spallation Neutron Source. The time for changes in local atomic connectivity, which is the timescale of atomic ordering, was determined by examining the decay of the nearest neighbor peak. The results of rigorous statistical analyses were used to distinguish between competing models of ordering, suggesting that a stretched exponential model of coordination number change is valid for this system. Full article

NiTi shape memory alloys (SMAs) are widely studied for their potential applications, and atomic layer deposition (ALD) is an effective technique for coating them due to its precise control over coating thickness. This study investigates the impact of Al₂O₃ coating on the fatigue behavior of cold-drawn NiTi wires with a 0.125 mm diameter. The wires were coated using atomic layer deposition (ALD) with 100 ALD cycles. Fatigue tests were conducted in tensile mode at room temperature, applying cyclic loading between 0–50, and 700 MPa (700 MPa is almost 40% of ultimate tensile strength). The results show that the cold-drawn NiTi wires failed after an average of 7500 tensile loading cycles, while the lifetime of the coated and stretched NiTi wires with a preload of 1.7–2.8 kg significantly improved, with an average of 293,000 cycles before failure. Full article

The impact of municipal pollution on the larvae of the Ukrainian brook lamprey and the European brook lamprey was studied in the River Gać, a left-bank tributary of the River Pilica. Both lamprey species share similar morphologies and habits, including filtration-based feeding and burial in soft river sediments. This study focused on a 200 m stretch of the river, divided by sewage discharge from a municipal wastewater treatment plant into unpolluted (above the discharge) and polluted (below the discharge) sections. The Ukrainian brook lamprey exhibited higher densities (1612 individuals in total over the study period) compared to those of the European brook lamprey (336 in total). Survival methods, such as body length-frequency charts, were used to determine age. These diagrams, showing multimodal distributions, facilitated the differentiation of age groups and the application of the von Bertalanffy growth function to determine growth parameters. The growth curves revealed that the Ukrainian brook lamprey achieve greater body lengths (246.7 mm for the unpolluted section; 256.3 mm for the polluted section) at the same age and asymptotic lengths when compared to those of the European brook lamprey (187.2 mm for the unpolluted section; 180.7 mm for the polluted section). Furthermore, the European brook lamprey exhibited inferior growth in the polluted river section compared to that of the Ukrainian brook lamprey. The response of both lamprey species to municipal pollution suggests that such pollution could promote the expansion of the Ukrainian brook lamprey, while causing the decline of European brook lamprey in areas of their overlapping habitat. Full article

Nanofluids, with their enhanced thermal properties, provide innovative solutions for improving heat transfer efficiency in renewable energy systems. This study investigates a numerical simulation of bioconvective flow and heat transfer in a Williamson nanofluid over a stretching wedge, incorporating the effects of chemical reactions and hydrogen diffusion. The system also includes motile microorganisms, which induce bioconvection, a phenomenon where microorganisms’ collective motion creates a convective flow that enhances mass and heat transport processes. This mechanism is crucial for improving the distribution of nanoparticles and maintaining the stability of the nanofluid. The unique rheological behavior of Williamson fluid, extensively utilized in hydrometallurgical and chemical processing industries, significantly influences thermal and mass transport characteristics. The governing nonlinear partial differential equations (PDEs), derived from conservation laws and boundary conditions, are converted into dimensionless ordinary differential equations (ODEs) using similarity transformations. MATLAB’s bvp4c solver is employed to numerically analyze these equations. The outcomes highlight the complex interplay between fluid parameters and flow characteristics. An increase in the Williamson nanofluid parameters leads to a reduction in fluid velocity, with solutions observed for the skin friction coefficient. Higher thermophoresis and Williamson nanofluid parameters elevate the fluid temperature, enhancing heat transfer efficiency. Conversely, a larger Schmidt number boosts fluid concentration, while stronger chemical reaction effects reduce it. These results are generated by fixing parametric values as $0.1<\varpi <1.5, 0.1<\mathit{Nr}<3.0, 0.2<\mathrm{Pr}<0.5, 0.1<\mathit{Sc}<0.4, \mathrm{and} 0.1<\mathit{Pe}<1.5.$ This work provides valuable insights into the dynamics of Williamson nanofluids and their potential for thermal management in renewable energy systems. The combined impact of bioconvection, chemical reactions, and advanced rheological properties underscores the suitability of these nanofluids for applications in solar thermal, geothermal, and other energy technologies requiring precise heat and mass transfer control. This paper is also focused on their applications in solar thermal collectors, geothermal systems, and thermal energy storage, highlighting advanced experimental and computational approaches to address key challenges in renewable energy technologies. Full article

Citrus waste is a source of phytochemicals with extensive health properties, mainly diglycosylated flavonoids. In this experiment, the characterization of dried peels from three main citrus species, lemon (Citrus limon), orange (Citrus sinensis), and grapefruit (Citrus paradisi), was performed using various analytical techniques. The FTIR spectra of each species show the characteristic bands of C=O stretching and O-H stretching and bending, and the PCA shows discrimination between species based on their chemical nature. The TPC determined by UV-vis spectroscopy was found to be higher for grapefruit peel by 12.4% and 38.9% compared to lemon and orange, which coincides with the individual flavonoid content obtained by HPLC-MS/MS. Meanwhile, full-scan HPLC-MS confirmed a wider variety of phytochemicals in lemon peel. Full article

This paper investigates points of vulnerability in the decisions made by backers and campaigners in crowdfund pledges in an attempt to facilitate a sustainable entrepreneurial ecosystem by increasing the rate of good projects being funded. In doing so, this research examines factors that contribute to the success or failure of crowdfunding campaign pledges using eXplainable AI methods (SHapley Additive exPlanations and Counterfactual Explanations). A dataset of completed Kickstarter campaigns was used to train two binary classifiers. The first model used textual features from the campaigns’ descriptions, and the second used categorical, numerical, and textual features. Findings identify textual terms, such as “stretch goals”, that convey both elements of risk and ambitiousness to be strongly correlated with success, contrary to transparent communications of risks that bring forward worries that would have otherwise remained dormant for backers. Short sentence length, in conjunction with high term complexity, is also associated with campaign success. We link the latter to signaling theory and the campaigners’ projection of knowledgeability of the domain. Certain numerical data, such as the project’s duration, frequency of post updates, and use of images, confirm previous links to campaign success. We enhance implications through the use of Counterfactual Explanations and generate actionable recommendations on how failed projects could become successful while proposing new policies, in the form of nudges, that shield backers from points of vulnerability. Full article

Lattice structures, composed of interconnected struts, offer an efficient way to reduce structural weight while maintaining structural integrity. Because of this potential, this work aims to investigate and develop an efficient variant form of a BCC (Body-Centered Cubic) lattice structure to enhance the structural robustness and energy absorption capability, based on the Maxwell stability criterion. And we specifically changed the bending-dominated to stretching-dominated behavior by adding auxiliary struts, according to the theory, and confirmed how this affects the compression behavior of the structure. For this purpose, horizontal auxiliary struts are added for the first time to the BCC structure along with vertical struts. As a macroscale cellular lattice structure, a unit cell size of 12 mm is considered. For the considered macroscale cellular lattice structures, FEA (finite element analysis) is employed to numerically investigate the stress distribution and compressive deformation mechanisms. Then, quasi-static compression tests are carried out to measure the energy absorption performance of the lattice structures manufactured by the EBM (Electron Beam Melting) metal additive manufacturing technique, which has advantages in building lattice structures without supporters. A comprehensive investigation reveals that a newly designed lattice structure offers significant advantages in structural robustness, with energy absorption capability increased by 365% compared to existing structures, achieved by incorporating vertical and cross-shaped horizontal auxiliary struts into the original BCC lattice configuration. The enhanced lattice structures can be utilized in industries where low-weight and high-strength are needed, such as aerospace, marine, and other industries. Full article

Pseudomonas fluorescens is a vital food spoilage bacterium that commonly spoils foods in the biofilm state. Uncovering the targets responsible for biofilm formation and disrupting their function is a promising way to control bacterial biofilms and food spoilage. In this work, using the combination of qRT-PCR and construction of the gene deletion strain, Δtdsr, TonB-dependent siderophore receptor D7M10_RS23410 was, for the first time, proven to play an essential part in the biofilm development of P. fluorescens. By utilizing structure-based virtual screening technology, a natural compound, adenosine monophosphate (AMP), with the highest binding activity to D7M10_RS23410, was obtained as an effective biofilm inhibitor. AMP significantly decreased the cell autoaggregation and biofilm biomass at sub-MIC concentrations (2.5, 1.25, and 0.625 mg/mL), mainly through inhibiting the generation of extracellular polymeric substances (EPS) in the biofilm matrix and promoting the cell motility. Furthermore, AMP was found to form hydrogen bonds with specific amino acid residues and stretched the protein structure of D7M10_RS23410, and this structural alteration undoubtedly interfered with the functionality of the D7M10_RS23410 protein. Full article

Background/Objective: Maintaining sufficient ankle joint range of motion (ROM) contributes to efficient movement in sports and daily activities. Static stretching (SS), while effective, demands significant time, highlighting the need for alternative, time-efficient approaches to improve ROM. Therefore, this study aimed to evaluate the effectiveness of combined intervention (CI) using neuromuscular electrical stimulation (NMES) and elastic tape versus SS. Methods: This randomized crossover trial was conducted in healthy university students. They underwent both interventions with a 1-week washout period. The CI entailed the application of elastic tape to the plantar surface of the foot coupled with NMES targeting the posterior lower leg muscles for 1 min. SS was administered for 5 min using a tilt table. Outcome measures included the dorsiflexion angle (DFA), finger-floor distance (FFD), straight leg raise (SLR) angle, plantar flexor strength (PFS), and knee flexor strength (KFS), assessed pre- and post-intervention. DFA was analyzed using equivalence testing with a predefined margin. Results: Both interventions yielded significant improvements in DFA, FFD, and SLR. The combination of NMES and elastic tape demonstrated equivalence to 5 min of SS in enhancing DFA. Neither intervention resulted in a significant reduction in PFS or KFS. Conclusions: The CI of NMES and elastic tape effectively and safely improves flexibility in a short time. Its time efficiency makes it a promising alternative to SS, especially for brief warm-ups or limited rehabilitation time. Further research should explore its long-term effects and broader applicability. Full article

A new species of Asian horned toad, Boulenophrys, is described from Yongzhou City, Hunan Province, China. The species is a phylogenetically sister to B. yunkaiensis, based on 16S rRNA and COI genes. The new species differs from its congeners, possessing the following combination of characters: (1) moderate body size: SVL 37.6–40.2 mm (38.9 ± 1.3, n = 7) in adult males and SVL 41.8–45.9 mm (43.6 ± 2.1, n = 3) in adult females; (2) tympanum boundary clear: TD/ED 0.48–0.57 in males and 0.47–0.57 in females; (3) the presence of a small horn-like tubercle at the edge of the upper eyelid; (4) vomerine ridge present and vomerine teeth absent; (5) margin of tongue rounded, not notched posteriorly; (6) rough dorsal skin: a discontinuous “V”-shaped ridge with two discontinuous dorsolateral ridges on two sides on the back, dense tubercles on the skin of the ventral surface of the dorsal shank and thigh, and spiny tubercles surrounding the cloaca; (7) slender hindlimbs with heels overlapping when the flexed hindlimbs are held at right angles to the body axis; tibio-tarsal articulation reaching forward between anterior margin of tympanum and posterior corner of eye when leg stretched forward; (8) relative finger length IV < II < I < III, with a subarticular tubercle present at the base of each finger; (9) distinct supernumerary tubercles below the base of I and II toes; (10) toes without lateral fringes and with rudimentary webbing (webbing formula: I1 − 1-II1 − 2-III2 − 3IV3- − 2V). Full article

The addition of even minute amounts of solid polymers, measured in parts per million (ppm), into a simple Newtonian fluid like water significantly alters the flow behavior of the resulting polymer solutions due to the introduction of fluid viscoelasticity. This viscoelastic behavior, which arises due to the stretching and relaxation phenomena of polymer molecules, leads to complex flow dynamics that are starkly different from those seen in simple Newtonian fluids under the same conditions. In addition to polymer solutions, many other fluids, routinely used in various industries and our daily lives, exhibit viscoelastic properties, including emulsions; foams; suspensions; biological fluids such as blood, saliva, and cerebrospinal fluid; and suspensions of biomolecules like DNA and proteins. In various microfluidic platforms, these viscoelastic fluids are often transported using electro-osmotic flows (EOFs), where an electric field is applied to control fluid movement. This method provides more precise and accurate flow control compared to pressure-driven techniques. However, several experimental and numerical studies have shown that when either the applied electric field strength or the fluid elasticity exceeds a critical threshold, the flow in these viscoelastic fluids becomes unstable and asymmetric due to the development of electro-elastic instability (EEI). These instabilities are driven by the normal elastic stresses in viscoelastic fluids and are not observed in Newtonian fluids under the same conditions, where the flow remains steady and symmetric. As the electric field strength or fluid elasticity is further increased, these instabilities can transition into a more chaotic and turbulent-like flow state, referred to as electro-elastic turbulence (EET). This article comprehensively reviews the existing literature on these EEI and EET phenomena, summarizing key findings from both experimental and numerical studies. Additionally, this article presents a detailed discussion of future research directions, emphasizing the need for further investigations to fully understand and harness the potential of EEI and EET in various practical applications, particularly in microscale flow systems where better flow control and increased transport rates are essential. Full article

To enhance the differentiation and maturation of cardiomyocytes derived from human induced pluripotent stem cells, we developed a bioreactor system that simultaneously imposes biophysical and biochemical stimuli on these committed cardiomyocytes. The cells were cultured within biohydrogels composed of the extracellular matrix extracted from goat ventricles and purchased rat-origin collagen, which were housed in the elastic PDMS culture chambers of the bioreactor. Elastic and flexible electrodes composed of PEDOT/PSS, latex, and graphene flakes were embedded in the hydrogels and chamber walls, allowing cyclic stretch and electrical pulses to be simultaneously and coordinately applied to the cultured cells. Furthermore, a dynamic analysis method employing the transverse forced oscillation theory of a cantilever was used to analyze and discriminate the subtype-specific beating behavior of the cardiomyocytes. It was found that myosin light chain 2v (MLC2v), a ventricular cell marker, was primarily upregulated in cells aggregated on the (+) electrode side, while cardiomyocytes with faint MLC2v but strong cardiac troponin T (cTNT) expression aggregated at the ground electrode (GND) side. mRNA analysis using rtPCR and the gel beating dynamics further suggested a subtype deviation on the different electrode sides. This study demonstrated the potential of our bioreactor system in enhancing cardiac differentiation and maturation, and it showed an intriguing phenomenon of cardiomyocyte subtype aggregation on different electrodes, which may be developed into a new method to enhance the maturation and separation of cardiomyocyte subtypes. Full article

Water in membrane interphases is vital for cellular biological functions, but despite its importance, the structure and function of biological water remain elusive. Here, by studying the OH stretching mode in partially hydrated lipid multilayers by FTIR measurements, relevant information on the water structure near the surface with lipid membranes has been gathered. The water hydrogen bond network is highly perturbed in the first layers that are in contact with the lipid membrane, exhibiting strong deviations from tetrahedral symmetry and a significant number of defects, such as isolated water molecules and a large number of hydrogen-bonded water dimers in the interphase region. These findings support the hypothesis that water chains form in phospholipid membranes, and are involved in the proton transfer across lipid bilayers by phosphate groups of opposing lipids. Furthermore, we have determined that even at very low hydration levels, a small amount of water is embedded within the confined spaces of the hydrocarbon region of phospholipid bilayers, which could potentially contribute to the structural stability of the lipid membrane. Full article

This study proposes a method for observing the inside of a temporary structure covered with a construction safety net using an image processing technique and 3D modeling. Images of the temporary structures were obtained using unmanned aerial vehicles (UAVs). Observing the inside of temporary structures is limited to using UAVs due to construction safety nets that act as obstacles. To solve this problem, the histogram equalization and grayscale stretching techniques were used to visualize the inside of a temporary structure covered by safety nets. After verifying the proposed method with small scale specimens, the proposed method was applied to climbing formwork installed at a construction site. Three-dimensional modeling technique was combined with improved images that were processed using the proposed method. The results indicated that the proposed method could identify internal objects that were not visible owing to safety nets. By comparing the original and improved images obtained through applying the proposed method, four target objects located inside the climbing formwork that were not visible owing to safety nets were sufficiently identified in the improved images. Thus, the proposed method can be effectively applied to identify the internal objects of temporary structures covered with safety nets. Full article