The initial adhesion of microbes onto plastics is crucial for the subsequent formation of the plastisphere, which might be affected by signal molecules commonly present in bacteria-related environments that regulate cell-to-cell communication. Herein, the initial retention performance of E. coli onto six types of plastics, both without and with N-acyl-homoserine lactones (AHLs, a common signal molecule) at concentrations ranging from 10 ng/L to 100 μg/L in suspension, was determined to reveal the influence of signal molecules on the formation of the plastisphere. We found that AHLs coexisting in suspensions significantly enhanced bacterial adhesion performance onto plastics, regardless of plastic types and AHL types, with a more pronounced enhancement observed at higher AHL concentrations. This enhanced bacterial adhesion induced by AHLs also held true in solutions containing humic acid, in river water, and in sewage. AHLs stimulated the synthesis of EPS, enhanced EPS hydrophobicity by altering the protein/polysaccharide ratio and its secondary structures, and upregulated pathways related to flagellar assembly, quorum sensing, protein production, and biofilm formation, thereby enhancing bacterial adhesion capability onto plastics. Moreover, AHLs adsorbed onto plastic surfaces could induce chemoattraction effects, further promoting bacterial adhesion performance. Obviously, through various mechanisms, the signal molecules greatly influence the initial adhesion of bacteria onto plastics in aquatic systems.
Adsorption-driven wettability transitions are fundamental to understanding fluid–solid interfacial phenomena and their impacts on diverse processes in nature and industry. In systems with multiple fluid species, competitive adsorption introduces additional complexity by altering interfacial energy and fluid behavior. This study employs molecular simulations and atomic force microscopy to investigate the CO2–n-decane competitive adsorption dynamics, serving as a model for geological surface sciences. At a typical geological temperature of 323.15 K, as pressure gradually increases to 1 MPa, CO2 molecules begin to displace the adsorbed n-decane. Due to interfacial energy effects, CO2 preferentially adsorbs at the solid–liquid–gas three-phase contact line and gradually penetrates the solid–liquid contact interface. With further pressure increases, CO2 molecules progressively form an adsorption layer at the solid–liquid interface, reaching a stable thickness of 1.14 nm at the pressure of 5 MPa. Beyond this value, the adsorption layer thickness decreases with increasing pressure as an indicative of the miscibility onset. A three-dimensional surface model FadTP is constructed to quantify critical thresholds of adhesion forces, identifying the conditions driving wettability transitions. Analysis of the Gaussian curvature of the Fad surface reveals critical thresholds corresponding to the wettability transition line in the T-P space, TP=1.00−1.62×107·P+1.71·P2. These quantitatively detailed observations deepen our understanding of the mechanisms underlying competitive adsorption-induced wettability transitions. Additionally, the study underscores the role of competitive adsorption in geological CO2-involved activities, where CO2-induced wettability transitions enhance utilization efficiency and storage security. This study contributes to optimizing processes across earth and environmental, industrial, as well as carbon neutrality efforts, advancing the understanding and application of competitive adsorption and wettability transition.
Nanoscale wettability, crucial for various disciplines in science and engineering, challenges traditional theory, particularly the Young's equation. This study proposes and validates a modified format of the Young's equation under nano-confinement and, for the first time, the nano-confined droplet morphological evolution and transition are investigated from thermodynamic theories and molecular dynamics simulation. The morphologies of droplets in nano-silts, identified as double-cap, single-cap, and bridge-shaped, underscore the critical roles of line tension and nano-confinement in characterizing wetting behavior. In hydrophobic nano-slits, droplets transition from the double-cap to the single-cap shape at the critical point of = 0.31 and to bridge shape at the critical point of = 0.40. Moreover, the relative width of the neck region in the bridge-shaped droplets is found to stabilize at ratio of 1.8. Particularly, linear relationships have been established between the droplet contact angle and the parameter , which identify condensation and breakage of droplets within hydrophobic nano-slits. This model effectively characterizes nanoscale wettability, with precise droplet behavior predictions, which could be beneficial to enhance nano-fluid dynamics understanding and its applications in science and engineering.
This article, which is an extension of the previous work of the authors (Tanveer and Ahmad (2022)) on yaw dynamics, investigates the modeling and control of heave degree-of-freedom of a compact custom designed ROV. Wherein, nonlinear data-driven modeling strategy is adopted to develop a high-fidelity heave dynamic model. The proposed modeling approach uses open-loop real-time experimental data to derive a high-fidelity NARX model of the vehicle. The resulting model accommodates the dynamics of the system in addition to the tether dynamics. The advantage of this approach is its ability to eliminate the need for intricate controller tuning. The identified model consistently demonstrated fitness scores ranging from 82% to 92% in both self-validation and cross-validation tests conducted on distinct datasets. This relative advantage is exemplified in real-time through the testing of a Genetic Algorithm Proportional-Integral (GAPI) controller. The performance of GAPI is subsequently compared with the relatively recent Marine Predators Algorithm (MPA) and the more conventional root-locus tuned PI controllers. The experimental results demonstrate that GAPI provides the most favorable response, achieving a 35%, 76%, and 44% improvement in rise time, percent overshoot and peak time, respectively. Furthermore, the controller effort required by GAPI running on an ATmega328 chipset is 22% less than its counterparts.
Generally, facilitating a slick switch to cleaner cooking fuels for households in the countryside has been a challenge. Based on survey data from the China Family Panel Survey for 2022 and provincial statistics, this study examined the effects of relevant factors on household cooking fuel utilization in rural China at the province, household, and neighborhood levels using a multilevel spatial logit model. The findings clearly indicate that new quality productive forces, household cultural consumption, and neighborhood effects significantly support households to adopt cleaner cooking fuels in rural areas. Further studies show that policies on green financial reforms and innovation, straw-burning ban guidelines, and atmospheric priority control areas activate new productive forces to support rural households’ switch to cleaner cooking fuels. These findings contribute to knowledge and action programs for the green transformation of rural energy consumption.
The poor endurance of hafnium oxide (HfO2)-based ferroelectric field-effect transistors (FeFETs) limits their applications. From a novel perspective of ferroelectric domain engineering, we propose and fabricate a high endurance HfO2-based FeFET with monolayer graphene (GR) inserted in the gate oxide for the first time. The introduction of GR between the ferroelectric (FE) layer and the interfacial layer (IL) increases the number of domains in the ferroelectric (FE) layer and reduces the electric field of the IL. Meanwhile, the low density of states (DOS) of monolayer GR suppresses the charge injection to further optimize the endurance. Experimental results show that the endurance of the GR-intercalated FeFET (GR-FeFET) exceeds 108 cycles, which is more than 2 orders of magnitude higher than that of the conventional FeFET. The gate leakage is also effectively suppressed by the GR layer. This work opens a new avenue for improvement of the endurance of FeFETs and demonstrates GR-FeFETs as potential candidates for next-generation embedded memory applications.
Occurrence and abundance of molecular hydrogen in natural geologic reservoirs are enigmatic, due to its various sources, diverse migration pathways and complicated biological and chemical reactions. Natural gas samples containing hydrogen from producing wells in several sedimentary basins in China were collected in this study, and gas abundances and isotopic compositions of these gases were compared with those in global petroliferous basins and deep intrusive rocks. Several geochemical indicators were suggested for identifying sources, migration and accumulation mechanisms of hydrogen in the subsurface environment. Hydrogen contents in natural gas deposits have contributions from various sources with the following high-to-low order: microbial degradation > serpentinization > deep mantle volatile release > radiation-induced water decomposition > thermal cracking of organic matter. A hydrogen-rich reservoir in Kansas, USA, is specifically analyzed to determine its formation mechanism. This study suggests that future exploration of geological hydrogen resources may focus on the igneous rock bodies with overlying dense sedimentary rocks in the continental rift systems.
WeproposeanODEapproachtosolvingmultiplechoicepolynomialprogram- ming (MCPP) after assuming that the optimum point can be approximated by the ex- pected value of so-called thermal equilibrium as usually did in simulated annealing. The explicit form of the feasible region and the affine property of the objective function are both fully exploited in transforming an MCPP problem into an ODE system. We also show theoretically that a local optimum of the former can be obtained from an equilib- rium point of the latter. Numerical experiments on two typical combinatorial problems, MAX-k-CUT and the calculation of star discrepancy, demonstrate the validity of the ODE approach, and the resulting approximate solutions are of comparable quality to those obtained by the state-of-the-art heuristic algorithms but with much less cost. When compared with the numerical results obtained by using Gurobi to solve MCPP directly, our ODE approach is able to produce approximate solutions of better quality in most instances. This paper also serves as the first attempt to use a continuous algorithm for approximating the star discrepancy.
