Scales Of Time Research Articles

Warming alters plankton body-size distributions in a large field experiment

The threat of climate change has renewed interest in the responses of communities and ecosystems to warming, with changes in size spectra expected to signify fundamental shifts in the structure and dynamics of these multispecies systems. While substantial empirical evidence has accumulated in recent years on such changes, we still lack general insights due to a limited coverage of warming scenarios that span spatial and temporal scales of relevance to natural systems. We addressed this gap by conducting an extensive freshwater mesocosm experiment across 36 large field mesocosms exposed to intergenerational warming treatments of up to +8 °C above ambient levels. We found a nonlinear decrease in the overall mean body size of zooplankton with warming, with a 57% reduction at +8 °C. This pattern was broadly consistent over two tested seasons and major taxonomic groups. We also detected some breakpoints in the community-level size-temperature relationship, indicating that the system’s response shifts noticeably above a certain level of warming. These results underscore the need to capture intergenerational responses to large gradients in warming at appropriate scales in time and space in order to better understand the effects of warming on natural communities and ecosystems.

Play–literacy interface in childhood education: Across the scales of time and space

Play has been widely examined and viewed as an effective pedagogy to promote children's literacy development. While current research has identified various benefits associated with play, discrepancies still exist regarding what type of play could be more effective, for example, home play or school play. This could further lead to an outcome-oriented, positivist perception of play as a designed intervention that risks neglecting children's agency in creating, negotiating, and interpreting their play activities. In this conceptual article, we explore the theoretical affordance of the concept of temporal and spatial scales to rethink children's play as a dynamic, multilayered flow of meaning-making and negotiation across time and space. We discuss how using the lens of scales, play can be analyzed as actions, processes, and contexts. The methodological and pedagogical implications of scales are also illustrated for practical applications in research and education on play-based literacy learning. Finally, this article aims to draw researchers and educators’ attention to the complexity and diversity of play, as well as children's agency in (re)constructing playfulness.

A Hybrid Approach to Model Reduction of Generalized Langevin Dynamics

We consider a classical model of non-equilibrium statistical mechanics accounting for non-Markovian effects, which is referred to as the Generalized Langevin Equation in the literature. We derive reduced Markovian descriptions obtained through the neglection of inertial terms and/or heat bath variables. The adopted reduction scheme relies on the framework of the Invariant Manifold method, which allows to retain the slow degrees of freedom from a multiscale dynamical system. Our approach is also rooted on the Fluctuation–Dissipation Theorem, which helps preserve the proper dissipative structure of the reduced dynamics. We highlight the appropriate time scalings introduced within our procedure, and also prove the commutativity of selected reduction paths.

New Nusselt Number Correlation and Turbulent Prandtl Number Model for Turbulent Convection with Liquid Metal Based on Quasi-DNS Results

Liquid metal is widely used as the primary coolant in many advanced nuclear energy systems. Prandtl number of liquid metal is much lower than that of the conventional coolant of water or gas. Based on the Reynolds analogy, the turbulent Prandtl number is assumed to be a constant around unity. For the turbulent convection of liquid metal, dissipations of half the temperature variance are larger than those of turbulent kinetic energies. The dissimilarity between the thermal and momentum fields increases as Pr decreases. The turbulent Prandtl number is larger than one for the liquid metal. In the current investigation, the turbulent convection of liquid metal in the channel is quasi-directly simulated with OpenFOAM-7. The turbulent statistics of the momentum and the thermal field are compared with the existing database to validate the numerical model. The power law for dimensionless temperature distribution with different Prandtl numbers is obtained by regression analysis of numerical results. A new Nusselt number correlation is derived based on the power law. The new Nusselt number correlation agrees well with the DNS results in the literature. The momentum mixing process between different layers in the cross section is compared with the thermal mixing process. The effects of the Prandtl number on the difference between the turbulence time scale and scalar time scale are analyzed. A new turbulent Prandtl number model with local parameters is obtained for turbulent convection with liquid metal. Combined with the k−ω model, the temperature distributions with the new turbulent Prandtl number model agree well with the DNS results in the literature. The new turbulent Prandtl number model can be used for turbulent convection with different Prandtl and different Reynolds numbers.

Evaluating the spatiotemporal patterns of GPP and tree growth for their response to CO2 fertilization effects in mid-latitude forests of China

ABSTRACT The investigation of the spatiotemporal variation trend of the atmospheric CO2 fertilization effect ( β ) has emerged as a prominent topic of interest on a global scale in recent times. Nevertheless, the spatiotemporal patterns of β remain unclear. Herein, we selected the mid-latitude forests of China as the designated study region. Accordingly, remote sensing Gross Primary Productivity (GPP) products were used along with model-based GPP simulation results and tree-ring data in this study. This was combined with the random forest algorithm and a moving window approach to assess the spatiotemporal patterns of vegetation productivity and tree growth responses to atmospheric CO2 variations between 1982 and 2015. Our findings suggest that from 1982 to 2015, the estimated β derived from the two remote sensing GPP products demonstrated a declining trend. In particular, the EC-LUE GPP exhibited a decrease rate of −0.46%.100 ppm−1yr−1, while the NIRv GPP showed a decrease rate of −0.04%.100ppm−1yr−1. Similarly, the findings from the estimation based on models also indicated a decline in β , with an average decrease rate of −0.08%.100 ppm−1yr−1 across a total of 18 models. Based on the analysis of tree rings from 16 sites, it was observed that the radial growth response of vegetation to atmospheric CO2 exhibited a decline with an average decrease rate of −0.81%.100 ppm−1yr−1. We speculated that the observed trend in β is primarily driven by LAI and forest age.

A computationally efficient and fully coupled model for sediment-borne contaminant transport

The river flow, sediment transport, bed deformation and contaminant transport are strongly coupled under the impacts of climate change and anthropogenic activities. Two-dimensional (2D) mathematical models are practical tools for predicting the morphodynamic processes and contaminant transport while their computational efficiency is a key impediment to simulations featuring large scales of time and space, especially when refined meshes are required for key spot such as hydraulic structures. Therefore, a computationally efficient and fully coupled 2D model for sediment-borne contaminant transport is established under the framework of Finite Volume Method on unstructured meshes in this paper. The computing strategies of local time stepping, parallel computing and high performance clusters are employed, which can speed up the computation and reduce the run time drastically. The model is tested against three experimental cases and one idealized test case, where numerical solutions are in general agreement with the measured data and analytical solution.

Layer-by-layer growth, apparent instability, and mound coarsening in thin film deposition controlled by thermally activated surface diffusion

Thin film deposition from vapor with adsorbate diffusion and Ehrlich-Schwoebel (ES) barriers at step edges is studied by kinetic Monte Carlo (KMC) simulations and scaling approaches. Mound coarsening with slope selection is shown at the largest thicknesses, where roughness (W) and correlation length (ξ) scale in time with exponents β≈n≈0.25, consistently with theoretical works but contrasting with previous simulations that systematically showed temperature-dependent exponents. At a given film thickness, we show that the mounded morphology is independent of the ES barrier, so that interlayer transport is suppressed, while the temperature increase of W and ξ is consistent with intralayer transport limited by adatom detachment from flat terrace borders. Initial layer-by-layer (LBL) growth occurs above a characteristic temperature that increases with the activation energies of terrace diffusion and of ES barrier, but weakly depends on the external flux. Subsequently, as the surface roughness is near the atom/molecule size, there is rapid roughening where, counterintuitively, larger effective growth exponents (β>0.5, suggesting unstable growth) are correlated with longer LBL regimes. Similar LBL-rough transitions were reported in organic film deposition and the model application to diindenoperylene films suggests a large ES barrier ∼0.4eV. In the mound coarsening regime, W/ξ and θ1/2/Wξ converge to constant values dependent on surface diffusion coefficients (θ is the film thickness). This convergence suggests mound coarsening with slope selection in SnTe films whose effective β is anomalously large, showing how film morphology can be interpreted beyond exponent measurements.

Adapting and validating the satisfaction, alertness, timing, efficiency, and duration-breast cancer (SATED-BC) scale for measuring sleep health in Spanish women treated for breast cancer.

After breast cancer (BC), women may face other severe symptoms such as sleep problems. The use of simple, fast, and reliable scales is necessary in the clinic to improve patient benefits, and sleep is an important aspect to be addressed. This study was conducted to adapt and validate the Spanish version of the satisfaction, alertness, timing, efficiency, and duration (SATED) scale for measuring sleep health in women who have completed treatment for BC in Spain (SATED-BC). Cross-sectional study. The adaptation process involved adding a sixth item to the SATED-BC scale: "the impact of symptoms experienced after completing breast cancer treatment on sleep" item was not considered for scoring. The SATED-BC score ranged from 0 (poorest sleep health) to 10 (best sleep health). A validation analysis was performed using the Pittsburgh Sleep Quality Index, the Consensus Sleep Diary, and actigraphy, and the results were compared with those obtained using the SATED-BC scale. The SATED-BC scale was reliable in terms of its internal consistency (Cronbach's α = 0.70; McDonald's ω = 0.72), showed high intrasubject reliability (r = 0.90), and was shown to be valid for use in women who have completed treatment for breast cancer. The SATED-BC scale is a reliable and valid tool for comprehensively evaluating sleep health in women who have completed treatment for breast cancer.

Using Radiogenic Noble Gas Nuclides to Identify and Characterize Rock Fracturing

AbstractFracture‐released radiogenic noble gas nuclides are used to identify locations and constrain the volume of new fracture creation during subsurface detonations. Real‐time, in situ noble gases and reactive gases were monitored using a field‐deployed mass spectrometer and automated sampling system in a multilevel borehole array. Released gases were measured after two different detonations having distinct energy, pressure, and gas volume characteristics. Explosive‐derived gases (N2O, CO2) and excess radiogenic 4He and 40Ar above atmospheric background are used to identify locations of gas transport and new fracture creation after each detonation. Fracture‐released radiogenic 4He is used to constrain the volume of newly created fractures with a model of helium release from fracturing. Explosive by‐product gas was observed in multiple locations both near and distal to the shot locations for both detonations. Radiogenic 4He and 40Ar release from rock damage was observed in locations near the detonation after the second, more powerful detonation. Observed 4He response is consistent with a model of diffusive release from newly created fractures. Volume of new fractures estimated from the 4He release ranges from 1 to 5 m2 with apertures ranging from 0.1 to 1 m. Our results provide evidence that radiogenic noble gases released during fracture creation can be identified at the field scale in real time and used to identify timing and location of fracture creation during deformation events. This technique could be useful in subsurface science and engineering problems where the location and amount of newly created rock fracturing is of interest including fault rupture, mine safety, subsurface detonation monitoring and reservoir stimulation.

DeLVE into Earth's Past: A Visualization-Based Exhibit Deployed Across Multiple Museum Contexts.

While previous work has found success in deploying visualizations as museum exhibits, it has not investigated whether museum context impacts visitor behaviour with these exhibits. We present an interactive Deep-time Literacy Visualization Exhibit (DeLVE) to help museum visitors understand deep time (lengths of extremely long geological processes) by improving proportional reasoning skills through comparison of different time periods. DeLVE uses a new visualization idiom, Connected Multi-Tier Ranges, to visualize curated datasets of past events across multiple scales of time, relating extreme scales with concrete scales that have more familiar magnitudes and units. Museum staff at three separate museums approved the deployment of DeLVE as a digital kiosk, and devoted time to curating a unique dataset in each of them. We collect data from two sources, an observational study and system trace logs. We discuss the importance of context: similar museum exhibits in different contexts were received very differently by visitors. We additionally discuss differences in our process from Sedlmair et al.'s design study methodology which is focused on design studies triggered by connection with collaborators rather than the discovery of a concept to communicate. Supplemental materials are available at: https://osf.io/z53dq/.

Ecofeminist Drought and Slow Ecological Grief in Fabienne Bayet-Charlton’s Watershed

ABSTRACT This article analyses temporalities of drought and grief in an understudied millennial Australian novel: Fabienne Bayet-Charlton’s Watershed. Watershed depicts a young white farming couple in rural Victoria battling a fierce drought while coping with prolonged grief over the death of their ten-year-old son. I contend that the layering of drought and grief in the text – both figured as slow forms of crisis – proffer slow temporalities that deal with both the small and large scales of space and time which constitute anthropogenic climate change. Using hydrocritical, postcolonial, and ecofeminist approaches, I show how the text articulates a politicised multiscalar yet embodied perspective which demonstrates the insights that a specifically freshwater approach to the blue humanities can bring to theorisations of environmental time and narrative strategy during planetary crisis.

Snow depth sensitivity to mean temperature, precipitation, and elevation in the Austrian and Swiss Alps

Abstract. Snow depth plays an important role in the seasonal climatic and hydrological cycles of alpine regions. Previous studies have shown predominantly decreasing trends in average seasonal snow depth across the European Alps. Additionally, prior work has shown bivariate statistical relationships between average seasonal snow depth and mean air temperature or precipitation. Building upon existing research, our study uses observational records of in situ station data across Austria and Switzerland to better quantify the sensitivity of historical changes in seasonal snow depth through a multivariate framework that depends on elevation, mean temperature, and precipitation. These historical sensitivities, which are obtained over the 1901–1902 to 1970–1971 period, are then used to estimate snow depths over the more recent period of 1971–1972 to 2020–2021. We find that the year-to-year estimates of snow depths, which are derived from an empirical–statistical model (SnowSens), that rely solely on the historical sensitivities are nearly as skillful as the operational SNOWGRID-CL model used by the weather service at GeoSphere Austria. Furthermore, observed long-term changes over the last 50 years are in better agreement with SnowSens than with SNOWGRID-CL. These results indicate that historical sensitivities between snow depth, temperature, and precipitation are quite robust over decadal-length scales of time, and they can be used effectively to translate expected long-term changes in temperature and precipitation into changes in seasonal snow depth.

The end of the ‘time of the streets’: Temporality in the life course of a Russian ex-gangster

We present the analysis of two biographical narratives by an ex-gangster from the Russian city of Kazan. We address the different times in his life – his childhood, youth, and adulthood, his time on the streets, his decision to leave the gang, and his reflections and memories of his past as reconstructed through these different narratives. We analyze the synchronicity of macro, meso, and micro scales of time in his biography and show how his memory of the time in the gang has dramatically changed between the first and second interviews, as he looked retrospectively on his former self from the vantage point of his current law-abiding life. In our analysis, we use the theoretical and conceptual framework of processual sociology and Bakhtin’s concept of chronotope.

Reconstruction of neuromorphic dynamics from a single scalar time series using variational autoencoder and neural network map

This paper examines the reconstruction of a family of dynamical systems with neuromorphic behavior using a single scalar time series. A model of a physiological neuron based on the Hodgkin–Huxley formalism is considered. Single time series of one of its variables is shown to be enough to train a neural network that can operate as a discrete time dynamical system with one control parameter. The neural network system is created in two steps. First, the delay-coordinate embedding vectors are constructed form the original time series and their dimension is reduced with by means of a variational autoencoder to obtain the recovered state-space vectors. It is shown that an appropriate reduced dimension can be determined by analyzing the autoencoder training process. Second, pairs of the recovered state-space vectors at consecutive time steps supplied with a constant value playing the role of a control parameter are used to train another neural network to make it operate as a recurrent map. The regimes of thus created neural network system observed when its control parameter is varied are in very good accordance with those of the original system, though they were not explicitly presented during training.

Associations Among Problematic Internet Usage in Adolescents, Parental Internet Factors, and Parent-Adolescent Communication.

Adolescents with problematic internet use (PIU) have excessive, impulsive, or risky internet use that negatively affects social, physical, and functional outcomes. The role of parents in the prevention of adolescent PIU remains unclear. The purpose of this study was to evaluate possible association between adolescent PIU, parent PIU, and internet-related parenting factors. Adolescents aged 12 to 18 years and a parent were recruited through national Qualtrics panels for an online cross-sectional survey. Adolescents and parents completed the Problematic and Risky Internet Use Screening Scale-3 (PRIUSS-3) and Internet-Specific Parenting Practices (ISPP) scales for (1) internet content (ISPP-content) and (2) time on the internet (ISPP-time). Adolescents completed ISPP for quality of parent communication regarding internet use (ISPP-Quality). Bivariate analyses examined relationships between adolescent PIU, parent PIU, and ISPP. In total, 4558 adolescents and 4568 parents completed surveys. Adolescent PIU prevalence was 69.9%. Parent PIU prevalence was 61.4%. Among parents with PIU, 87% had an adolescent with PIU compared with only 42% of parents without PIU (OR = 9.54, 95% CI: 8.24-11.05). More lenient content parenting practices and stricter time parenting practices were associated with increased likelihood of adolescent PIU. The quality of parent communication around the internet was lower for adolescents with PIU. Study findings suggest that coaching around positive parent-child relationships and healthy family internet use habits that include shared digital experiences may more effectively address PIU than enforcing child screen time limits.

Switch monitoring algorithm for 220 kV terminal substation startup process based on multi time scale graph model

The switch monitoring in the startup process of 220 kV terminal substation is a dynamic and changeable process, which has obvious characteristics of diversified scales in time, so as to solve the problem of switch monitoring under multivariable and multi-scale interference. The switch monitoring framework for the startup process of 220KV terminal substation is built. The process layer uses the graphic configuration software and combines the internal and external models of the substation to build the objective function for the generation of the substation graphic model. The particle swarm optimization algorithm is used to solve it to generate the optimal substation graphic model. Through the online monitoring device, the signals such as sensors, normally open and normally closed contacts are collected in real time, and the status of the switchgear is obtained through processing, the reduced half trapezoidal cloud model multivariable multi-scale sample entropy similarity tolerance criterion is used for softening treatment, and the multivariable multi-scale cloud sample entropy is determined to achieve the extraction of multiple time scale switch fault feature vectors, which are used as the input of the SE-DSCNN fault diagnosis model. Combined with the substation diagram, the switch fault identification during the startup process of the substation is realized, and the fault switch position is located. The experimental results show that the algorithm can accurately generate the substation model, which includes all the equipment in the substation, accurately describes the connection relationship and operation status of the equipment, and has high accuracy, integrity and aesthetics; The algorithm can effectively extract and analyze the MMCES entropy characteristics of different types of switch faults; The algorithm can realize the switch monitoring during the startup of substation C, and determine the fault switch and fault location.

Spiralling Inverse Method: A New Inverse Method to Estimate Ocean Mixing

Abstract Here, we introduce the Spiralling Inverse Method (SIM) that provides estimates of the small-scale and mesoscale mixing strength. The SIM uses a vertical integral over a balance between the water mass transformation equation and the thermal wind equation. The result is an equation where all terms, except for the mixing strengths, can be obtained from hydrographic data of temperature and salinity. As an advantage, the SIM estimates the mixing strengths without the need for further knowledge of a reference velocity or streamfunction. Here, we apply the SIM to a small region in the North Atlantic. We find that the estimates obtained by the SIM compare well to observations and other (inverse) estimates of the mixing strength. The SIM therefore has the potential to improve and constrain parameterizations used for climate and ecosystem modeling using readily available hydrographic data. Significance Statement Ocean mixing is a combination of many different physical processes over a large range of scales in time (from seconds to years) and space (from millimeters to 100 km). Most of these processes are too small to compute in climate models and need to be simplified (parameterized). These parameterizations have a strong influence on climate projections, and their shape and magnitude need to be constrained using observations and indirect estimates of ocean mixing strength. The Spiralling Inverse Method (SIM) is a new method to obtain such constraints of mixing strengths using readily available observations of temperature and salinity. We here test the SIM and confirm its potential to improve mixing estimates and therewith ultimately climate simulations.

Reduced data-driven turbulence closure for capturing long-term statistics

We introduce a simple, stochastic, a-posteriori, turbulence closure model based on a reduced subgrid scale term. This subgrid scale term is tailor-made to capture the statistics of a small set of spatially-integrated quantities of interest (QoIs), with only one unresolved scalar time series per QoI. In contrast to other data-driven surrogates the dimension of the “learning problem” is reduced from an evolving field to one scalar time series per QoI. We use an a-posteriori, nudging approach to find the distribution of the scalar series over time. This approach has the advantage of taking the interaction between the solver and the surrogate into account. A stochastic surrogate parametrization is obtained by random sampling from the found distribution for the scalar time series. We compare the new method to an a-priori trained convolutional neural network on two-dimensional forced turbulence. Evaluating the new method is computationally much cheaper and gives similar long-term statistics.

A posteriori error estimation and adaptivity for temporal multiscale problems

AbstractIn science and engineering, problems over multiple scales in time often arise. Two examples are material damage in oscillating structures or plaque growth in pulsating blood vessels. Here the long term effects are of interest but they depend on the coupled fast‐changing physical processes which must be taken into account. One method to efficiently simulate these problems is to split them into an averaged slow scale process and a localized fast scale process. We apply the dual weighted residual method on a generalized formulation for this type of problem to obtain an error estimator which can be used for adaptive refinement. Special care must be taken to separate the slow scale and fast scale influences on the estimator.

THE IMPORTANCE OF EXPANDING RESEARCH ON THE SERPENTINIZATION OF OPHIOLITE ROCKS BY NATURAL “WHITE” HYDROGEN FOR KAZAKHSTAN

In Kazakhstan, options and regions for hydrogen production are being considered, including in Western Kazakhstan, the Mangystau region, using the water of the Caspian Lake. The current advanced hydrogen production technologies, including green hydrogen, are very expensive, requiring billions of dollars of investment and potentially creating difficulties for the local population and nature, ecology, flora and fauna. At the same time, geological studies of alternative hydrogen production options in Kazakhstan are poorly developed. Kazakhstan needs and is currently very important to study serpentinization of ophiolite rocks using natural «white» hydrogen. In many countries, there is practically a «gold rush» now, hydrogeologists are conducting research on the search for natural «white» hydrogen. Hydrogeologists have now discovered numerous sources of natural hydrogen in geological environments from Mali to Switzerland, France, Germany, the USA, Canada, and Australia. More than 50 companies have sprung up to discover and mine it. A natural hydrogen well operates in Mali to provide energy to a local city with a population of about 4,000 people for free and forever. Unlike other geological fuels, which are formed over millions of years, natural hydrogen is generated by mixing water and iron particles, serpentinization of ophiolite rocks, and is renewable on the scale of human time, and not in geological epochs. Alternative options for the production and use of hydrogen are presented in this review, including various types of hydrogen, black, gray, green, blue, turquoise, pink and yellow, depending on the method of its extraction and production. Kazakhstan, with the richest natural ore reserves, including coal and polymetals, where ophiolite rocks may be located, may well have deposits of natural «white» hydrogen, such geological studies in Kazakhstan are poorly developed.