Static State Research Articles

Experimentation Evaluation of Dynamics of Steel Wire Rope

Wire ropes represent a distinct category of ropes synthesized through the intertwining or braiding of individual steel wires. This unique construction confers notable attributes such as strength, flexibility, and durability to the resultant rope. The pervasive wire ropes across diverse industries underscores their capacity to adeptly manage substantial loads and endure adverse environmental conditions finding its application in mechanical, civil, mining, and marine engineering. This paper presents usage of image processing method to detect the deflection of a steel wire rope. The system comprises of dividing the wire rope into different sections, spatial referencing, frame separation, color-based detection, morphological operations, data collection and visualization. The steel wire rope deflection program will allow designers to conveniently process the transverse deflection trajectories of a steel wire rope in real time. One may further introduce any control actions when the deflection distance reaches a threshold value. The image-based algorithm enabled a robust detection of the deformed shape as a function of time, thus obtaining its dynamic trajectories. The deflection shapes and trajectories are compared with numerical predictions made using Cosserat Rod theory, which considers the geometric nonlinearities introduced due to large deflection. The numerical solution gave a rough estimate of the static deformation state of the wire, which agrees with the experimental results. This study will be useful for Structural Health Monitoring, Safety Assurance, Fatigue Analysis and Performance optimization. Moreover, the Continuum Mechanics employs Cosserat rod theory to model continuum robots which will provide enhanced computational efficiency and better dynamic simulation capabilities[18]. The deflection shapes and trajectories are compared with analytical predictions made using Cosserat Rod theory, which considers the geometric nonlinearities introduced due to large deflection.

Bioinspired adaptive lipid-integrated bilayer coating for enhancing dynamic water retention in hydrogel-based flexible sensors

While hydrogel-based flexible sensors find extensive applications in fields such as medicine and robotics, their performance can be hindered by the rapid evaporation of water, leading to diminished sensitivity and mechanical durability. Despite the exploration of some effective solutions, such as introducing organic solvents, electrolytes, and elastomer composites, these approaches still suffer from problems including diminished conductivity, interface misalignment, and insufficient protection under dynamic conditions. Inspired by cell membrane structures, we developed an adaptive lipid-integrated bilayer coating (ALIBC) to enhance water retention in hydrogel-based sensors. Lipid layers and long-chain amphiphilic molecules are used as compact coating and anchoring agents on the hydrogel surface, mimicking the roles of lipids and membrane proteins in cell membranes, while spare lipids from aggregates within hydrogels can migrate to the surface to combat dehydration under deformation. This lipid-integrated bilayer coating prevents the water evaporation of hydrogels at both static and dynamic states without affecting the inherent flexibility, conductivity, and no cytotoxicity. Hydrogel-based sensors with ALIBC exhibited significantly enhanced performance in conditions of body temperature, extensive deformation, and long-term dynamic sensing. This work presents a general approach for precisely controlling the water-retaining capacity of hydrogels and hydrogel-based sensors without compromising their intrinsic physical properties.

Linking glacier retreat with climate change on the Tibetan Plateau through satellite remote sensing

Abstract. Under global climate change, glaciers on the Tibetan Plateau are experiencing severe retreat, which significantly impacts the regional water cycle and the occurrence of natural hazards. However, detailed insights into the spatiotemporal patterns of this retreat and its climatic drivers remain insufficiently explored. In this study, an adaptive glacier extraction index (AGEI) is proposed based on the analysis of multispectral Landsat images integrated with the Google Earth Engine, and comprehensive and high-resolution mapping of glaciers on the Tibetan Plateau is realized at 5-year intervals from 1988 to 2022. Subsequently, the ERA5-Land air temperature and precipitation data are downscaled to a finer 1 km resolution. Finally, the impacts of the annual and seasonal changes in the downscaled meteorological factors on the glacier extent are quantified. Results demonstrate a rapid yet heterogeneous pattern of glacier retreat across the Tibetan Plateau between 1988 and 2022, with retreat rates ranging from 0.14 ± 0.07 % to 0.51 ± 0.09 % annually. A notable trend is observed: most glaciers experienced a decrease in extent from 1990 to 2000 followed by a slight increase from 2000 to 2010. From 2010, a majority of the glaciers exhibited either a static state or minimal retreat. The most pronounced impact of annual temperature on glacier retreat is observed in the southern Himalayas, with a value of −9.34 × 103 km2 °C−1, and the most restraining impact of precipitation on glacier retreat reaches 261 km2 mm−1, which is observed in the Karakoram Range for the spring season. These insights are pivotal in comprehending the temporal and spatial heterogeneity of glacier retreats and in understanding the effects of climatic variations on the state of glaciers on the Tibetan Plateau.

Cyclical Cosmology, Energy and Curvature of Space-Time

Cyclical cosmic conditions illuminate profound philosophical and physical implications regarding the fundamental nature of the universe. From this perspective, a singularity could actually symbolize a transformation of the underlying structures and laws of our universe, providing insights into the relationships among energy, curvature, and existence of the universe itself. In cyclical cosmology, the universe can be understood as existing in two distinct states: a static potential state and an active kinetic state. Quantum mechanics also reinforces the belief that even in seemingly empty spaces, vacuum fluctuations and differences in potential can give rise to emergent phenomena.

Dynamic visualization of DNA methylation in cell cycle genes during iPSC cardiac differentiation.

Existing analyses with conventional assays have generated significant insights into static states of DNA methylation but were unable to visualize the dynamics of epigenetic regulation. We utilized a genomic DNA methylation reporter (GMR) system carrying Snrpn minimal promoter and CpG regions of Cdk1 (Cyclin-dependent kinase 1) or Sox2 (SRY-Box Transcription Factor 2). Mouse Sox2 GMR iPSCs rapidly lost fluorescent reporter signal upon the induction of cardiac differentiation. Cdk1 GMR reporter signal was strong in undifferentiated iPSCs, and gradually decreased during cardiomyocyte differentiation. RT-qPCR and pyrosequencing demonstrated that the reduction of Sox2 and Cdk1 was regulated by hypermethylation of their promoters' CpG regions during cardiac differentiation. The GMR reporter system can be useful for monitoring real-time epigenetic DNA modification at single-cell resolution.

The Influence of Steering Axle Design Parameters and Operational Factors on Tire Steering Resistance Torque

This paper presents the results of the study of the kinematics and dynamics of an elastic steered wheel depending on its state, the kingpin unit design parameters, and the tire characteristics in order to obtain dependencies for calculating the tire steering resistance torque in static state and during movement. It was established that when steering in static state, the locked steered wheel is taken as a complex mechanism, and the tire contact patch is rotated about the kingpin axis–support surface intersection point. When turning the unlocked steered wheel, it was determined that the tire contact patch participates in transport and relative motions. The transport motion center is the projection onto the support surface of the center of rotation of the wheel about the kingpin axis. The relative motion center is within the contact patch and is determined experimentally. For both states of the steered wheel, analytical dependencies were obtained for determining the tire steering resistance torque. The results of the analytical studies were experimentally verified on a bench equipped by components and aggregates of a truck, and included an additional rigid false wheel and a special rim. The false wheel made it possible to experimentally determine the tire contact patch transport motion center, and the special rim—to change the knuckle length in the range of 0.22–0.82 m.

Efficiency of the dynamic relaxation method in the stabilisation process of bridge and building frame

More and more complex Civil Engineering problems are being considered in computational mechanics with the invention of high-quality computing techniques. In addition, the computational cost and storage requirement for complex and or large structures have increased dramatically, leading to an increased interest in removing the difficulties using any form of parallel computing. The process of applying the preload for parallel computing to any unstable structures is called a stabilising process, such as the Dynamic Relaxation Method (DRM) is one. This method minimises the energy by a simple vector iteration technique, which ultimately leads the structure to a static equilibrium state. The present study aims to highlight the utility of the DRM in the stabilisation process for small structures like building frames and large and or complicated structures such as bridges before actual transient analysis. Therefore, the present manuscript discusses the computational cost, CPU runtime, multiple increases of mass and rigid body displacement of building frames and bridges. The DRM allows an explicit solver to conduct a dynamic analysis by increasing the damping until the kinetic energy drops to a proposed value. The simulation of the DRM starts to find the equilibrium state with minimal dynamic effect, which is required to apply at the beginning of the solution phase to obtain the initial stress and displacement field before the start of the actual analysis.

Optimal Hyperspectral Characteristic Parameters Construction and Concentration Retrieval for Inland Water Chlorophyll-a Under Different Motion States

In recent decades, the rapid expansion of phytoplankton blooms caused by lake eutrophication has led to severe ecological destruction and impeded the sustainable economic development of local regions. Chlorophyll-a (Chl-a) is commonly used as a biological indicator to detect phytoplankton blooms due to its ease of detection. To improve the accuracy of Chl-a estimation in aquatic systems, an accurate understanding of its true spectral characteristics is imperative. In this study, a comprehensive and realistic experimental scheme was designed from the perspective of real algal strains and real water states. Both in situ and laboratory-based hyperspectral data were collected and analyzed. The results show that there are huge spectral differences not only between laboratory-cultured and real algae strains, but also between static and disturbed water surface conditions. A total of ten different categories of spectral characteristics were selected in both disturbed and static states. Then, six parameters with the best models to the Chl-a concentration were identified. Finally, two linear models of the Chl-a concentration at peaks of 810 nm and 700 nm were identified as the best estimation models for the static and disturbed states, respectively. The results provide a scientific reference for the large-scale retrieval of the Chl-a concentration using satellite remote sensing data. This advancement benefits inland water monitoring and management efforts.

Charged Dyson shells supported in curved spacetimes of spherically symmetric central compact objects

It is proved that charged thin shells (charged Dyson shells) can be supported in unstable static equilibrium states around spherically symmetric central compact objects. The regime of existence of the composed central-compact-object-static-charged-shell configurations is characterized by the inequalities m(m+2M)<|q|<M+M2+m2\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\sqrt{m(m+2M)}<|q|<M+\\sqrt{M^2+m^2}$$\\end{document}, where {m,q}\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\{m,q\\}$$\\end{document} are respectively the proper mass and the electric charge of the supported shell and M is the mass of the central compact object (a black hole or an horizonless compact star). We reveal the physically interesting fact that the supported charged shells become marginally-stable in the |q|/m(m+2M)→1+\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$|q|/\\sqrt{m(m+2M)}\\rightarrow 1^+$$\\end{document} limit, in which case the lifetime (instability timescale) of the composed system can be made arbitrarily large. Our analysis goes beyond the test shell approximation by properly taking into account the exact gravitational and electromagnetic self-interaction energies of the spherically symmetric shell in the curved spacetime. In particular, the existence of the composed compact-object-charged-shell static configurations in the Einstein–Maxwell theory is attributed to the non-linear electromagnetic self-energy of the supported shell.

Uphill dynamics: A spring-mass model analysis of sloped walking

This study explores the biomechanics of uphill running by adjusting and analyzing the spring- mass model. Modifications specific to slope conditions were made to the equations of motion. Despite facing challenges in code execution, an in-depth investigation of the models physical characteristics was conducted through both static and dynamic state analyses. The findings aid in the theoretical understanding of motion on sloped surfaces and provide valuable experience for subsequent research.

Where are the cruise ships? mobility and immobility of cruises under COVID-19.

The aim of this study is to reveal the spatial-temporal characteristics and influencing factors of the static and dynamic distribution of global cruise ships, against the backdrop of the COVID-19 pandemic, which has transformed the global cruise network from "lines" to "points". This study collected trajectory data for 292 cruise ships and data for 789 cruise ports worldwide from March 2020 to July 2021. Based on the relationship between port and navigation, port management rights research, and port geography theory, we analyzed the spatial distribution and spatiotemporal migration of cruise ships with ArcGIS tools. It was found that, compared with normal times, the distribution of cruise ships in regional markets, countries, and ports showed stronger spatial agglomeration characteristics and formed four types, which were mainly influenced by differences in cruise operators' fleet scale, positioning, and itinerary. With the improvement of the epidemic, cruise ships trended to gather at the cruise home port. During the COVID-19 pandemic, there was an obvious separation between the epidemic prevention country, flag country, and operator country. Operators were inclined to berth their cruise ships in the countries where cruise ships were registered, countries of operators, and ports with high integration. Rather than simply emphasizing the static state of the cruise shipping network, the global cruise geography under the COVID-19 pandemic reflects the right relationship between ports, cruise ships, and companies. This study provides a methodological framework for analyzing the cruise shipping network at the port level and has practical implications for micro-interpretation of the dotted cruise shipping network during the COVID-19 pandemic.

Molecular motion in supramolecular ionic crystal of Swiss cheese structure

Abstract In most molecular crystals, crystal structure collapses when solvent molecules are removed. We report the crystal of (isobutylammonium+)(dibenzo[18]crown-6)[Ni(dmit)2]−•0.4CH3CN with Swiss cheese–like structure, in which 60% of the CH3CN sites are voids. The motion of isobutylammonium+ adjacent to the void sites maintains the single crystallinity, which occupy an apparently larger volume than in the static state. This study opens up the possibility of developing novel relaxor dielectrics based on molecular motion in the crystal of partially occupied voids.

The Effect on Poly-β-hydroxybutyrate Production the Presence of Different Carbohydrate Sources in Bacillus ceresus and Cupriavidus necator

Polyhydroxybutyrates (PHB) are granular polyesters synthesized by many bacteria as a carbon and energy source in environments where substances such as nitrogen, oxygen, carbon, and phosphorus are limited. Polyhydroxybutyrates is biodegradable, consisting of hydrophobic long chains, and is non-toxic. It is classified as one of the basic polymers of polyhydroxyalkanoates. In this study, the Polyhydroxybutyrates production of Bacillus cereus (ATCC 10876) and Cupriavidus necator (formerly Ralstonia eutropha ATCC17699) in the presence of different minimal carbon sources was investigated under static and shaking (150 rpm) states. According to the results of the research, the highest PHB production was observed in Bacillus cereus PBS + 1% xylose medium (7.395 µg/ml) in static conditions; Cupriavidus necator exhibited the highest production of polyhydroxybutyrates under shaking conditions in PBS + 1% fructose medium (9.626 µg/ml). The lowest polyhydroxybutyrates production was observed in Cupriavidus necator in PBS + 1% maltose medium (0.027 µg/ml) under static conditions; however, under shaking conditions, it was carried out in PBS + 1% dextrose medium (0.122 µg/ml). Considering these results, it is evident that there is an increase in the production of polyhydroxybutyrates by microorganisms as the shaking speed.

Experimental Study of Airfoil Aerodynamic Behavior under Oscillating Motion in Ground Effect

When a flying vehicle approaches a water or land surface, it induces changes in the fluid flow field pattern known as the "ground effect." This research analyzes the ground effect phenomenon, exploring its impact on aerodynamic coefficients and flow patterns around the NACA0012 airfoil in an incompressible subsonic regime under static and dynamic conditions with pitch movements. Numerical simulations and experimental testing in an incompressible subsonic wind tunnel were deployed. The flow field solution is derived from the Navier-Stokes equations, incorporating the Transition SST turbulence model. Initially, the impact of the ground effect phenomenon was investigated at varying distances from the surface in the static state. Subsequently, the airfoil underwent a sinusoidal pitching oscillation at each distance with a specified frequency and amplitude. This allowed for examining its aerodynamic characteristics over time. The static analysis results reveal alterations in the curve's behavior and pressure distribution on the airfoil surface at close distances to the surface. This is attributed to the ground effect phenomenon, which reduces lift force to a certain height and then increases. Dynamic analysis further demonstrates changes in lift coefficient oscillation amplitude. It also exhibits a minimum and maximum lift point phase difference as the airfoil approaches the surface.

Dynamic response of an aeroelastic airfoil within ground effects of flat and wavy surfaces

Due to the significant threat posed by waves to the safety of ground-effect vehicle, a numerical study has been conducted to reveal the impact patterns on the dynamic response of an aeroelastic airfoil flying above flat and wavy ground surfaces compared with the case of in far field. The two degrees of freedom dynamic equations are coupled with the governing equations of incompressible flow with the Reynolds number based on a chord length of Re=6.85×107. The airfoil is capable of pitching and plunging motions driven by both elastic and aerodynamic forces. The effects of spring stiffness and damping ratio on aeroelastic flutter of the airfoil are explored within flat ground effect and wavy ground effect conditions, respectively. Compared to the airfoil in the far field, the aeroelastic airfoil exhibits better stability within the flat ground effect. Within the ground effect of flat surface, as the spring stiffness decreases, the dynamic response of the airfoil can be categorized into four different types: static state (U*=5, 6, and 7), limit cycle oscillation (U*=8), nonlinear random oscillation (U*=9), and stall-induced collision with the ground (U*=10). When flying above waves, the airfoil experiences sustained wave excitation, resulting in intensified velocity fluctuations and increased susceptibility to collision with ground. The effectiveness of damping in mitigating flutter and preventing crashes is demonstrated for airfoils within the ground effect. These findings provide valuable insights into the risks associated with aeroelastic flutter of the airfoil within the ground effect, offering implications for the safety design of wing-in-ground vehicles.

Ивент-анализ: применение в социальном прогнозировании

Monitoring the interrelationships between social events and phenomena and forecasting the dynamics of their changes are necessary in the conditions of instability of the modern world. There are many separate methods of analysis for social forecasting, however, for this research, the method of event analysis has been chosen, which is insufficiently considered in the scientific literature within the framework of this task, but has high potential. The purpose of the article is to adapt the event analysis methodology for its use as a social forecasting tool. The main data for the study was collected from the Russian information and news resource in the period 2020-2023. Based on the classical methodology of event analysis, the classifiers presented in this paper in the form of social spheres are defined in the research. As part of the analytical comparison stage, a graph analysis was carried out (graphs of relationships between categories were constructed, central nodes-categories were identified); time series analysis was performed (segmentation of time series by the PELT algorithm, clustering of time series by the k-means algorithm); key terms for press events were defined. The final product is an analytical dashboard with filters, statistics and interactive graphs. The analytical dashboard makes it possible to compare data in a static and dynamic state, to draw conclusions about the past and future states of objects of social forecasting. The main result of the research is the event analysis methodology developed by the author, which can be used for a comprehensive analysis of news streams, adapted to the necessary categories representing a certain entity or sphere, and applied in various social organizations or monitoring services.

A Dynamic and Static Combined State Recovery Method Against FDI Attacks in Power Grids

A Dynamic and Static Combined State Recovery Method Against FDI Attacks in Power Grids

Machine-Learning Approach PredictsGel Strength of Drilling Fluid While Drilling

_ This article, written by JPT Technology Editor Chris Carpenter, contains highlights of paper OTC 35433, “Novel Machine-Learning Approach for Predicting the Gel Strength of the Drilling Fluid While Drilling,” by Ahmed Gowida, SPE, and Salaheldin Elkatatny, SPE, King Fahd University of Petroleum and Minerals. The paper has not been peer reviewed. Copyright 2024 Offshore Technology Conference. _ Accurately estimating gel strength is paramount for optimizing drilling operations and preventing cuttings from settling at the wellbore’s bottom. Traditional methods rely on rotational viscometers, which are time-intensive, equipment-dependent, and lack real-time monitoring capabilities. This study underscores the feasibility of leveraging machine learning (ML) as a practical tool for predicting drilling-fluid gel strength, offering real-time monitoring and precise predictions to enhance drilling efficiency, safety, and automation initiatives. Background The gel strength of drilling fluid is assessed using a viscometer, focusing on the 3-rev/min reading obtained after agitating the fluid at 600 rev/min to disrupt any gel formation. Initially, the measurement is taken when the mud reaches a static state for 10 seconds. Subsequent readings are conducted at 10- and 30-minute intervals. The rationale behind the 30-minute reading lies in its ability to indicate whether the mud forms a substantial gel during prolonged static periods, such as when tripping out a bottomhole assembly. Elevated gel strength may result in increased pump pressure required to restore circulation after extended static conditions. Additionally, a consistent upward trend in the 30-minute gel strength suggests the accumulation of ultrafine solids. Consequently, appropriate measures such as chemical treatments or dilution with fresh base fluid are necessary to address this issue. The frequency of measuring various fluid properties is tailored to their respective effects on well-control and drilling operations. These frequent evaluations allow for timely adjustments and monitoring of rheological measurements, offering valuable insights into rock sensitivity and the performance of mud activity and stability after exposure to drilled formations. On the other hand, a complete mud test (including all mud rheological properties) is performed twice a day because it consumes considerable time. It has been observed that mud rheological properties exhibit a significant correlation with two fundamental mud properties: mud weight and Marsh funnel (MF) viscosity. To the best of the authors’ knowledge, a dearth of research exists in the literature aimed at predicting the gel strength of drilling fluid using ML techniques. Consequently, this research endeavor introduces a novel ML model designed specifically for forecasting the gel strength of synthetic oil-based mud systems. Such predictive models are poised to enhance drilling performance by optimizing mud functions. Leveraging MF and mud-density measurements, the developed models aim to forecast the rheological properties of drilling fluid, thereby facilitating improved monitoring of mud functionality during drilling operations at the rig site.

His and hers earnings trajectories: Economic homogamy and long-term earnings inequality within and between different-sex couples

Economic homogamy has important implications for gender inequality and for economic inequalities between households. However, the long-term association between spouses’ earnings is not well understood. This study reconceptualizes economic homogamy as a life course process rather than a static state of being that can be adequately captured at a single point in time. Using data from the National Longitudinal Survey of Youth 1979, I examine the association between spouses’ earnings trajectories over the course of 30 years of marriage to identify three distinct gender egalitarian earnings patterns among couples. 50 % of couples follow a Dual earner pattern, in which spouses follow similar, stable earnings patterns over time, 6 % of couples are Jointly mobile in that spouses’ earnings vary similarly and 5 % follow an Alternating earner pattern. A large minority of couples follow patterns of long-term specialization, with 34 % of couples following Male breadwinner patterns and 5 % following Female breadwinner patterns. Multivariate analysis reveals that gender egalitarian earnings patterns are stratified by couples’ socio-economic status at marriage: while advantaged couples follow Dual earner patterns comprised of two stable earners, disadvantaged couples follow egalitarian earnings patterns characterized by joint earnings instability. By taking a long-term approach, this study provides insight into the varied ways gender equality in earnings manifests among married couples and reveals an important and understudied dimension of economic homogamy: the concentration of economic stability and instability within couples.

Multiple-objective control of stormwater basins using deep reinforcement learning

ABSTRACT Stormwater basins are important stormwater control measures which can reduce peak flow rate, mitigate flooding volume, and improve water quality during heavy rainfall events. Previous control strategies for stormwater basins have typically treated water quality and quantity as separate objectives. With the increasing urban runoff caused by climate change and urbanization, current single-objective control strategies cannot fully harness the control potential of basins and therefore require improvement. However, designing multi-objective control strategies for basins is challenging because of the conflicting operation goals and the complexity of the dynamic environmental conditions. This research proposes a novel real-time control strategy based on deep reinforcement learning to address these challenges. It employs a deep Q-network to develop an agent capable of making control decisions. After being trained on three different rainfall events, the reinforcement learning agent can make appropriate decisions for previously unseen rainfall events. Compared to the other two rule-based control scenarios and a static state scenario, the deep reinforcement learning method is more effective in terms of reducing total suspended solids, reducing peak flow, minimizing outflow flashiness, and controlling effort, striking a good balance between conflicting control objectives.