Temporal Instability Research Articles

Supplemental Material for The Temporal Instability of Aesthetic Preferences

Supplemental Material for The Temporal Instability of Aesthetic Preferences

Design and characterization of a continuous solar simulator for photovoltaic modules with automatic I-V curve acquisition system

This paper presents the development, characterization, and testing of a continuous large-area solar simulator for PV modules with an automatic I-V curve acquisition system and the results of a CIGS PV module over 25 h of light soaking. The simulator was developed to perform the IEC 61215 stabilization test and automatic characterization of PV modules during indoor testing. The equipment records the I-V curves of the PV module at programmed time intervals so that the change in the electrical characteristics of the PV modules can be tracked over time. The test plane has an area of 1.2 × 2 m and an irradiance of 800 W/m2. The simulator was installed in a container and consists of 16 metal halide lamps of 1 kW each. The simulator is characterized by temporal instability, spatial non-uniformity, and spectral mismatch, resulting in CCB classification. The I-V curves of the tested PV module were measured every 30 s, with 200 I-V points per curve. The power change of the tested module occurs mainly in the first 12 min and stabilizes after about 5 h under the conditions selected for the test. The developed device can save significant resources compared to commercial continuous solar simulators. The ability to automatically track changes in PV module electrical parameters during light-soaking tests is presented in detail and provides important information for future work related to the development and characterization of solar simulators of this type.

Temporal instability of a viscous liquid film on an oscillating plane in the presence of static electric field

This work examined the linear instability of a two-dimensional liquid film on an oscillating plane theoretically in the presence of a static electric field perpendicular to the plane. The liquid was considered to be viscous and perfectly conducting, while the gas was considered to be viscous and dielectric. The viscous potential theory and Floquet theory were adopted to obtain the dispersion equation. The influences of electric field intensity, forcing amplitude, forcing frequency, and viscosity were obtained. The results showed that with there is more than one instability region with a non-zero forcing amplitude. The first instability region is called inherent instability, which is due to the electric force overcoming the viscous dissipation, surface tension, and gravity, while the other regions are due to the parametric instability induced by the oscillating plane, forming famous Faraday waves. It was found that increasing the forcing amplitude stabilizes the inherent instability but has a destabilizing impact on Faraday waves. In addition, the increase in the electric field intensity and forcing frequency enhances the inherent instability but has a complex impact on the Faraday waves, depending on the intensity of the viscous dissipation, which is approximately proportional to the square of the wavenumber.

Temporal Instability and Transferability Analysis of Daytime and Nighttime Motorcyclist-Injury Severities Considering Unobserved Heterogeneity of Data

Using motorcycle crash data from 2016 to 2019, this paper aims to uncover and compare the risk factors that influence the severity of motorcyclist injuries sustained in daytime and nighttime motorcycle crashes in Thailand. Mixed-ordered probit models with means and variances in heterogeneity were used to take into consideration unobserved heterogeneity. The temporal instability of risk factors was also extensively explored. The results show that male motorcyclists, speeding, fatigue, crashes in work zones, crashes on raised median roads, intersection-related crashes, crashes on wet roads, and crashes on unlit roads are all factors that are positively associated with the risk of death and serious injury in nighttime crashes. The presence of pillions, crashes on two-lane roads, crashes on depressed/flush median roads, crashes in rural areas, U-turn-related crashes, weekend crashes involving heavy vehicles, and head-on crashes are factors that were positively associated with risk of death and serious injury for both daytime and nighttime crashes. This study’s findings provide evidence that factors that influence motorcycle accidents during the daytime and nighttime vary significantly. Additionally, nighttime crashes typically carried a higher risk of fatalities or serious injuries compared to daytime crashes. A discussion of policy recommendations is also provided.

Development of a sample cell for Radio Frequency µSR studies of metal nanoparticle systems with surface-adsorbed reactants in mesoporous hosts

We have recently begun an investigation of paramagnetic (free-radical) final states formed on metal nanoparticles by muonium (Mu) reactivity with surface-adsorbed molecules. The nanoparticles are incorporated into mesoporous silica, facilitating specific reaction steps in the silica host that involve H-atom transfer reactions important to studies in heterogeneous catalysis. Radio frequency (RF) methods are an essential tool for characterising final state species in these systems, and a non-metallic sample cell is essential for the RF field to penetrate the sample. Unfortunately, several significant problems were encountered during initial experiments using a cell made from PEEK polymer, the most serious being a temporal instability in the signals likely due to reactant molecules adsorbing on the PEEK. This paper discusses the problems encountered using the PEEK cell, and then considers the development of a ceramic cell designed to give better reproducibility in the measurements. The success of this new cell is demonstrated both through off-line tests and by muon measurements, including a series of TF 2G Mu spin precession measurements verifying the temporal stability of the experimental setup. Finally, an RF cavity was fashioned, and RF measurements made for muons stopped in bare silica, with signals from both diamagnetic and paramagnetic muon states clearly seen.

Temporal instability and age differences of determinants affecting injury severities in nighttime crashes

Driving at nighttime may make drivers more likely to be involved in fatal crashes. To investigate the temporal instability and age differences of contributors determining different injury severity levels in nighttime crashes, this paper estimates three groups of random parameters logit models with heterogeneity in the means and variances (young/middle-age/old groups). Nighttime single-vehicle crashes in this study are gathered over four years in California, from January 1, 2014, to December 31, 2017, provided by Highway Safety Information System, including single-vehicle crashes occurring under dark, dawn, and dusk lighting conditions. Simultaneously, to investigate the temporal instability and transferability of nighttime crash severity relating to drivers of different ages, three disaggregate groups are defined: young drivers (15–29 years old), middle-age drivers (30–49 years old), old drivers (over 49 years old). Three injury-severity categories are determined as outcome variables: severe injury, minor injury, and no injury, while multiple factors are investigated as explanatory variables, including driver characteristics, vehicle characteristics, roadway characteristics, environmental characteristics, crash characteristics, and temporal characteristics. Two series of likelihood ratio tests are undertaken to unveil the contributors determining nighttime crash injury severities varying among drivers of different ages over time. Besides, the current study also compares the differences between out-of-sample and within-sample predictions. The results indicate the unstable direction of predictions across different age groups over time and underscore the necessity to adequately accommodate the temporal instability and age differences in accident prediction. More studies can be conducted to accommodate the self-selectivity issue and the out-of-sample prediction differences between using the parametric models and non-parametric models.

Modeling injury severities of single and multi-vehicle freeway crashes considering spatiotemporal instability and unobserved heterogeneity

ABSTRACT Single and multi-vehicle (SMV) crashes remain a significant issue, causing serious safety and economic concerns, and therefore deserve more attention. Using crash data in the Beijing-Shanghai and Changchun-Shenzhen freeways over the five years (2015–2019), this paper explored the transferability and heterogeneity for crash type (single-vehicle versus multi-vehicle crashes) and spatiotemporal stability of determinants affecting the injury severity. The random parameters logit approach with heterogeneity in means and variances was used to model three possible crash injury severity outcomes (measured by the most severely injured individual in the crash) of no injury, minor injury, and severe injury and identify the determinants in terms of driver, vehicle, roadway, environment, temporal, spatial, traffic, and crash characteristics. Remarkable differences were observed in the SMV crashes, and the contributing factors also reported considerable temporal and (or) spatial instabilities. The insights of this study should be valuable to help freeway designers and decision-makers understand the contributing mechanism of the factors and develop the proper management strategies and enforcement countermeasures.

A temporal analysis of crash injury severities in multivehicle crashes involving distracted and non-distracted driving on tollways

Distracted driving is a prominent cause of traffic crashes and may increase the severity of collisions. Due to the larger speeds on toll ways, distracted driving crashes are more severe than on other types of roads, making it worthwhile to investigate. This study examined the variation in the influence of factors affecting injury severity in crashes involving distracted and non-distracted driving, as well as the change over time, using crash data from Florida toll ways from the 2017 to 2019. A series of random parameters logit models with heterogeneity in the means and variances were developed to analyze different driver-injury severities (no injury, minor injury, and severe injury) in crashes involving distracted and non-distracted driving. In addition, likelihood ratio tests were conducted to determine whether model parameters differed between different driver behaviors (distracted/non-distracted driving) and among years. Several factors potentially impacting injury severities were studied, including driver, crash, vehicle, roadway, environment, temporal, and others. Significant disparities were observed between the contributing factors of the severity of crashes involving distracted and non-distracted driving. Results showed that considerable differences were also observed in the severity of injuries caused by two types of crashes and distracted driving resulted in more serious crashes than non-distracted driving. Despite model results indicated that factors influencing injury severity altered over time, several factors, such as motorcycle involvement and commercial car involvement, still exhibited relative temporal stability in non-distracted driving crashes over the three years. Temporal instability and non-transferability were also captured by out-of-sample predictions to verify the temporal shifts of contributing variables from year to year. This study is useful for distinguishing the influence mechanisms between the two types of crashes involving distracted and non-distracted driving, and the results can be applied for safety countermeasures development.

Temporal Instability of Motorcycle Crash Fatalities on Local Roadways: A Random Parameters Approach with Heterogeneity in Means and Variances.

Motorcycle accidents can impede sustainable development due to the high fatality rate associated with motorcycle riders, particularly in developing countries. Although there has been extensive research conducted on motorcycle accidents on highways, there is a limited understanding of the factors contributing to accidents involving the most commonly used motorcycles on local roads. This study aimed to identify the root causes of fatal motorcycle accidents on local roads. The contributing factors consist of four groups: rider characteristics, maneuvers prior to the crash, temporal and environmental characteristics, and road characteristics. The study employed random parameters logit models with unobserved heterogeneity in means and variances while also incorporating the temporal instability principle. The results revealed that the data related to motorcycle accidents on local roads between 2018 and 2020 exhibited temporal variation. Numerous variables were discovered to influence the means and variances of the unobserved factors that were identified as random parameters. Male riders, riders over 50 years old, foreign riders, and accidents that occurred at night with inadequate lighting were identified as the primary factors that increased the risk of fatalities. This paper presents a clear policy recommendation aimed at organizations and identifies the relevant stakeholders, including the Department of Land Transport, traffic police, local government organizations, and academic groups.

Estimating the overall fraction of phenotypic variance attributed to high-dimensional predictors measured with error.

In prospective genomic studies (e.g., DNA methylation, metagenomics, and transcriptomics), it is crucial to estimate the overall fraction of phenotypic variance (OFPV) attributed to the high-dimensional genomic variables, a concept similar to heritability analyses in genome-wide association studies (GWAS). Unlike genetic variants in GWAS, these genomic variables are typically measured with error due to technical limitation and temporal instability. While the existing methods developed for GWAS can be used, ignoring measurement error may severely underestimate OFPV and mislead the design of future studies. Assuming that measurement error variances are distributed similarly between causal and noncausal variables, we show that the asymptotic attenuation factor equals to the average intraclass correlation coefficients of all genomic variables, which can be estimated based on a pilot study with repeated measurements. We illustrate the method by estimating the contribution of microbiome taxa to body mass index and multiple allergy traits in the American Gut Project. Finally, we show that measurement error does not cause meaningful bias when estimating the correlation of effect sizes for two traits.

Unrelaxed tensile stress impacts on the instability of viscoelastic sheets with the gas velocity oscillation

A temporal instability analysis of a viscoelastic liquid sheet with unrelaxed tensile stresses in the oscillation gaseous flow field has been studied with the Floquet method in the present research. Effects of the oscillated amplitude and frequency of incoming gaseous flow on the instability features in the different instability regions are analyzed systematically. Results reveal that the unrelaxed tensile stress has a positive effect on stabilizing the liquid sheet, while the higher oscillation amplitude would promote the sheet breakup. Besides, it is indicated that when the stress tensor would be controlled by the viscoelastic effects, elastic impacts would suppress the breakup, while it shows an opposite impact when the stress tensor is dominated by the tensile stress. The existence of parametric instability regions is influenced by the oscillated and elastic parameters as well.

Vertical organic electrochemical transistors for complementary circuits

Organic electrochemical transistors (OECTs) and OECT-based circuitry offer great potential in bioelectronics, wearable electronics and artificial neuromorphic electronics because of their exceptionally low driving voltages (<1 V), low power consumption (<1 µW), high transconductances (>10 mS) and biocompatibility1–5. However, the successful realization of critical complementary logic OECTs is currently limited by temporal and/or operational instability, slow redox processes and/or switching, incompatibility with high-density monolithic integration and inferior n-type OECT performance6–8. Here we demonstrate p- and n-type vertical OECTs with balanced and ultra-high performance by blending redox-active semiconducting polymers with a redox-inactive photocurable and/or photopatternable polymer to form an ion-permeable semiconducting channel, implemented in a simple, scalable vertical architecture that has a dense, impermeable top contact. Footprint current densities exceeding 1 kA cm−2 at less than ±0.7 V, transconductances of 0.2–0.4 S, short transient times of less than 1 ms and ultra-stable switching (>50,000 cycles) are achieved in, to our knowledge, the first vertically stacked complementary vertical OECT logic circuits. This architecture opens many possibilities for fundamental studies of organic semiconductor redox chemistry and physics in nanoscopically confined spaces, without macroscopic electrolyte contact, as well as wearable and implantable device applications.

Spatio-temporal progression and influencing mechanism of local wetting in membrane distillation

Membrane wetting is the bottleneck of membrane distillation (MD) in real applications. However, rare information is attainable on the spatial inhomogeneity and temporal instability of local wetting behavior along the membrane. In current study, the influences of operating conditions (i.e., feed temperature, velocity, and concentration) and membrane hydrophobicity on the spatio-temporal progression of local wetting along the membrane were evaluated using a non-invasive and online monitoring technique – ultrasonic time-domain reflectometry (UTDR). UTDR measurements could successfully distinguish local wetting dynamics and were validated by the off-line characterization of the wetting layer thickness via a scanning electron microscopy with energy-dispersive x-ray spectroscopy. Observations showed that the local wetting depth decreases along the feed flow direction. This wetting heterogeneity would be impaired with increasing surfactant concentration, feed temperature, and crossflow velocity. However, enhancing membrane hydrophobicity obviously reduced the rate of local wetting but hardly affected its nonuniform distribution. The wetting heterogeneous propagation at different locations is dominated by the nonuniform mass and heat transfer characteristics along the membrane based on the computational fluid dynamics (CFD) simulation. Localized wetting prevention near the module inlet is therefore critical to ensure stable MD operation.

Alternative metrics for characterizing longer-term clinical outcomes in difficult-to-treat depression: I. Association with change in quality of life.

In difficult-to-treat depression (DTD) the outcome metrics historically used to evaluate treatment effectiveness may be suboptimal. Metrics based on remission status and on single end-point (SEP) assessment may be problematic given infrequent symptom remission, temporal instability, and poor durability of benefit in DTD. Self-report and clinician assessment of depression symptom severity were regularly obtained over a 2-year period in a chronic and highly treatment-resistant registry sample (N = 406) receiving treatment as usual, with or without vagus nerve stimulation. Twenty alternative metrics for characterizing symptomatic improvement were evaluated, contrasting SEP metrics with integrative (INT) metrics that aggregated information over time. Metrics were compared in effect size and discriminating power when contrasting groups that did (N = 153) and did not (N = 253) achieve a threshold level of improvement in end-point quality-of-life (QoL) scores, and in their association with continuous QoL scores. Metrics based on remission status had smaller effect size and poorer discrimination of the binary QoL outcome and weaker associations with the continuous end-point QoL scores than metrics based on partial response or response. The metrics with the strongest performance characteristics were the SEP measure of percentage change in symptom severity and the INT metric quantifying the proportion of the observation period in partial response or better. Both metrics contributed independent variance when predicting end-point QoL scores. Revision is needed in the metrics used to quantify symptomatic change in DTD with consideration of INT time-based measures as primary or secondary outcomes. Metrics based on remission status may not be useful.

Light Sources and Irradiance Spectrum of LED solar simulator for photovoltaic devices: A Review

There is a growing demand for more applications for photovoltaic systems, which are a significant electricity source from renewable energy. Its performance test using a solar simulator is required. Light sources of solar simulator including halogen lamps and xenon lamps have been adapted to LED as a result of lamp technology. The goal of this article is to review LED solar simulator (LSS) light sources and spectrum for photovoltaic devices. Review articles from ScienceDirect and IEEE Explore from 2003 to 2022 were chosen as the basis for this analysis. The examination of spatial non-uniformity (S NE ), temporal instability, and spectral match (SM) under international standards was the result of the LSS's thorough investigation of the LED light sources design. The review discovered that LED-halogen solar simulators (LHSS) and LSS are the two main categories of solar simulator based on LED. The advantage of LHSS is that just one type of light source is required for the spectrum distribution on the infrared range. The drawback is that SM cannot be in class A. While LSS can reach class AAA and deliver good spectral coverage results in accordance with the new standard, IEC60904-9:2020, employing 10-23 LEDs of various wavelengths. The current state of LSS development is to design and build a modular LED array. S NE is still an important indicator of LSS that is reflected in the source design that is stable, economical, and sustainable. The new IEC 60904-9:2020 A+ category is discussed. The future direction of LSS for PV applications is suggested.

Bancas... de jornal? Mesmice e adaptação nas paisagens das cidades

Abstract With the movements of the streets and the constant socio-technical transformations, the newsstands conventionally used to commercialize printed titles were redimensioned amidst the urgent temporal and social instabilities in the possible relationships of each place. Paying attention to the adaptability of the newsstands due to the urban contexts, this article focuses on the newsstands we have come across in exploratory journeys in cities of seven states of Brazil in order to reflect on “the lives of the newsstands” and think them as communicational environments that admit different formats due to the crossings with the spaces that constitute them and taking them as constituent agents of the spaces.

NONLINEAR EHD STABILITY OF ENCLOSED COAXIAL JETS WITH MASS AND HEAT TRANSMISSION IN THE EXISTENCE OF AN OSCILLATORY GAS VELOCITY PROFILE

In this paper, the present work investigates a nonlinear temporal instability of coaxial cylinders in porous media in the existence of an oscillating gaseous velocity. Heat and mass transfer (MHT), as well as a uniform axial electric field were all taken into account. The viscous potential flow (VPF) was employed to calculate liquid and gas velocities to make the mathematical manipulations easier. As a result of the analysis of the boundary-values problem, the cylindrical interface displacement provided a nonlinear characteristic equation. To achieve the stability inspection, a novel approach was created. The article designates both the oscillatory and uniform streaming gas. The nonlinear analysis was completed using the homotopy perturbation method (HPM), which resulted in a Klein-Gordan equation, to arrive the stability maps. Additionally, the resonance and non-resonance cases were accomplished. In the previous situations, the stability standards were theoretically derived and numerically proven using regular diagrams. It was found that the unchanging flowing had a twofold effect. The linear MHT parameter was identified to perform a twofold character in the stability setup. On the other hand, nonlinear parameters have opposing effects. The outcomes of the homogeneous gas velocities were substantially conforming.

Positive effects of warming do not compensate growth reduction due to increased aridity in Mediterranean mixed forests

AbstractIncreased winter and early spring temperatures due to climate change can enhance forest productivity due to earlier growth onset in temperate regions. However, drought‐prone forests can be highly vulnerable to the combined effect of high summer temperatures and water stress. Understanding how water stress and rising temperatures along the growing season control tree growth in co‐occurring species with contrasting drought tolerances is key to project climate change effects on forest dynamics. Here, we evaluated the interactive effect of seasonal temperature and water availability on annual radial growth and climate–growth instability over six decades (1951–2015) in three pine species with contrasting drought tolerances (Pinus pinaster, Pinus nigra, and Pinus sylvestris). For this, we retrospectively observed radial tree growth using dendroecological methods and evaluated seasonal temperature and water availability effects by using linear mixed models. Early growing season temperature and water availability had a positive effect on tree growth, but the positive effect of late season temperature was modulated by water availability. Moving time‐window analyses revealed temporal instability in climate–growth relationships. Since the 1980s, pine species showed a higher growth sensitivity to both seasonal temperatures and annual water availability. Furthermore, growth reductions were more pronounced due to increased summer temperatures and reduced precipitation. Our results were similar for the three studied pine species despite their contrasting tolerance to drought. Overall, climate warming effects on pine growth are contingent upon water availability in Mediterranean continental forests. Synchronization among species, climate–growth instability, and negative growth trends suggests an increased vulnerability to drought of Mediterranean pine species in response to ongoing climate change.

Understanding the temporal dynamics of thermally activated delayed fluorescence in solid hosts

This perspective presents the efforts towards understanding the nature of the temporal instability of thermally activated delayed fluorescence in solid hosts as well as its implications for emission properties.

“Shadowtime”

AbstractThis paper explores “shadowtime”, or the co-existence of multiple temporalities, in Michelle Paver’s novelDark Matter: A Ghost Story(2010).Dark Matteris filled with temporally strange figures that evade human vision and understanding. Central among these is the spectral presence of agengånger, or ghost, which haunts the Arctic research station where the novel is largely set. After tracking some of the metaphorical and material dimensions of the spectral, this essay investigates “shadowtime” in the context of the novel’s various ‘archives’. It then looks at how the incorporeal or immaterial concepts of value and choice frame the novel’s ‘dark matters’. ‘Possibility’, or the question of ‘what if?’ pervades the novel’s pages, encouraging readers to imagine multiple realities simultaneously. This essay argues that, although set in a period predating wide awareness of climate change,Dark Matter’s “shadowtimes” create forms of temporal and ontological instability that resonate with the existential uncertainties of the Anthropocene.