Time Elapses Research Articles

Spatiotemporal Relationship between Ecosystem Service Value and Ecological Risk in Disaster-Prone Mountainous Areas: Taking the Upper Reaches of the Minjiang River as an Example.

Mountainous areas are susceptible to disasters; the frequent occurrence of disasters drives the changes in ecosystem service value (ESV) and also brings certain ecological risk, which further increases the incidence of disasters. However, few scholars have investigated the spatiotemporal correlation between the ESV of disaster-prone mountainous areas and ecological risk index (ERI) with basin as the unit. This paper aims to clarify the spatial relationship between ESV and ERI under the changes of land use. Taking the upper reaches of the Minjiang River as the study area, the authors collected the land use data of 2000–2020, estimated ESV by the value equivalent factor per unit area method, and constructed the ERI. On this basis, the relationship between ESV and ERI was investigated in details. The results show the following: (1) From 2000 to 2020, the total ESV exhibited a fluctuating upward trend. The spatial distribution of ESV was greatly affected by slope and altitude; an important reason for the rising ESV in the study area is the increase of forest area and water area. (2) The upper reaches of the Minjiang River had a generally low ERI and relatively good overall ecoenvironment. After 2010, however, the ecological risk continued to rise. Most of the strongly high risk areas are areas with frequent human activities, such as low-altitude areas and river banks. (3) There is a spatial correlation and coupling between ESV and ERI in the study area; i.e., the strongly high ESV areas generally had a low ecological risk. The correlation intensified with the elapse of time. The changes in the service value of regional ecosystems driven by unreasonable land use will have a great impact on the ecoenvironment. By clarifying the spatiotemporal relationship between ESV and ERI, this research provides theoretical basis and data support to the formulation of ecoenvironmental restoration and protection plans for the upper reaches of the Minjiang River and to the coordinated development between society, economy, and ecoenvironment in the region.

AN EXPERIMENTAL INVESTIGATION ON LIQUID SHEET BREAKUP DUE TO PERFORATIONS IN IMPINGING JET ATOMIZATION

In this work, atomization of the liquid sheet formed by two like-on-like impinging liquid jets is studied experimentally. The primary focus of this study concerns sheet breakup due to the formation and growth of perforations on the liquid sheet. In this mode of atomization, perforations or holes originate at a location where the liquid sheet becomes thin due to stretching. As time elapses, these perforations will grow in size and move either toward the bottom or toward the rim of the sheet. Depending on the initial location of their formation, these perforations either interact with the rim of the sheet or with other surrounding perforations and disintegrate the sheet into ligaments, which further disintegrate into drops. The phenomenon of perforation formation and growth is captured using a high-speed backlight imaging technique and processed using in-house-developed image processing algorithms based on MATLAB. The effect of liquid properties and Reynolds number on the growth of perforations is studied in this work. Based on the experiments conducted in this study, perforation-based atomization is broadly classified into three different modes. In the first mode, a single perforation interacts with the rim and disintegrates the sheet into ligaments. In the second mode, two or more perforations interact, and their common area of interaction is disintegrated into ligaments and droplets. In the third mode, the liquid sheet breaks up due to perforation interaction with impact waves. Studies on atomization behavior of the liquid sheet at high ambient pressure up to 0.8 MPa revealed improved atomization.

Impact of Hydrodynamic and Interfacial Interactions on Scale Formation in a Capillary Microchannel.

This study proposes a model for the kinetics and hydrodynamics of gypsum scale deposition on surfaces of anhydrite, calcite, dolomite, and sandstone rocks while interacting with the brines of 3000 and 6000 mg/L [Ca2+] at 363 K and 1 atm. To do so, this study utilizes the surface energy characteristics of an interacting scale-brine-rock system as well as the geochemical interactions between brine-brine and brine-rock. The results showed that the deposition flux decreases steeply over time, followed by asymptotic propensity as time elapses. A higher degree of salinity in terms of [Ca2+] increases the deposition flux as much as 2.9-fold for the flowing velocity of 10-6 m/s and 2.4-fold for a velocity of 10-5 m/s. Moreover, higher flow velocity would lead to more deposition on sandstone followed by carbonate and anhydrite rocks: ∼2.6-fold for the salinity of 3000 mg/L and 2.2-fold for 6000 mg/L [Ca2+].

Simulating the collision of a moving droplet against a moving particle: Impact of Bond number, wettability, size ratio, and eccentricity

This paper presents a direct numerical simulation for the collision of a moving droplet against a moving particle under gravity, based on the pseudopotential lattice Boltzmann model. The effects of Bond number (Bo), particle surface wettability, particle–droplet size ratio (α), and eccentricity ratio (B) on the collision processes are investigated comprehensively. Six findings are reported and analyzed for the first time: (1) an agglomeration process is observed for the collision with a very small Bond number. During the agglomeration process, the vertical velocity of the particle will experience a deceleration, and the deceleration will become weak against the increase in the Bond number. (2) The wettability will influence the variation of the vertical velocity of the moving particle remarkably. The vertical velocity of the neutral particle is nearly linearly accelerated, but the lyophilic particle experiences an obvious deceleration. In addition, the velocity history of the lyophobic particle shows a nonlinear acceleration. (3) The increase in the particle–droplet size ratio will postpone the emergence of the deceleration process. Therefore, the appearance of the peak vertical velocity is delayed against the increase in the particle–droplet size ratio. (4) For different eccentricity ratios, the differences of the velocities (e.g., the horizontal, vertical, and angular velocity) are very small in the beginning of collision, while a big difference appears with time elapses. Besides, the variation of velocities becomes very obvious. (5) There is a critical value for B, where the horizontal velocity, vertical velocity, and angular velocity of the particle investigated in the work all will reach their maximum values. (6) A rebound regime is observed when a moving droplet collides vertically against a moving particle. In the available literature, a rebound regime was observed only when a droplet colliding against a fixed particle, but never for a vertically moving particle. The present research reveals when a rebound process will appear. The finding here may shed some light on the mechanism of the collision of a moving droplet against a moving particle.

Morphology evolution of an atmospheric pressure glow discharge initiated in the air gap between a liquid cathode and a needle anode

Self-deformation has been observed for an atmospheric pressure diffuse discharge initiated in the air gap between a needle anode and a water cathode, which undergoes a morphology scenario from a cone, an axially symmetric horn, to a rectangular horn as time elapses. During the self-deformation process, pH value and electric conductivity of the water cathode vary with time. Moreover, electrical measurements indicate that applied voltage and discharge current are time-invariant for the conical discharge, while periodically pulsed for the other two discharges. This may suggest different formation mechanisms of them. Hence, fast photography is implemented by a high-speed video camera and an intensified charge coupled device. Results indicate that the diffuse discharges with different morphologies belong to a glow discharge regime. Among them, the conical discharge is composed of stationary micro-discharge, and the horn-shaped discharges consist of moving micro-discharge. Moreover, the axially symmetric horn is a self-rotating version of the rectangular horn. Furthermore, the rectangular horn originates from the swing of a micro-discharge filament like a pendulum motion. Finally, qualitative explanations are given for the experimental phenomena mentioned above.

Who has set whose agenda on social media? A dynamic social network analysis of Tweets on Paris attack

ABSTRACT This study investigates the agenda-setting theory in the context of social media through dynamic social network analyses of 102,145 Tweets in a week after Paris attack on Twitter. Results indicate that professional mass media organizations still hold a greater agenda-setting power than individual opinion leaders for setting the public agenda, as they obtain significantly more tweets, mentions, and replies from the public. While the overall media agenda significantly correlates with the agenda set by the individual opinion leaders on Paris attack, time-series analysis reveals the intermedia agenda-setting effects between mass media and individual opinion leaders on Twitter are immediate and decrease as time elapses. Methodological and theoretical implications are discussed.

Sediment and morphological changes along Yangtze River\u2019s 500\xa0km between Datong and Xuliujing before and after Three Gorges Dam commissioning

The impoundment of the Three Gorges Dam on the Yangtze River begins in 2003 and a full pool level is first attained in 2010. This process leads to reciprocal adjustments in flow discharge, sediment transport and morphology downstream of the dam. Based on 26-year recorded hydrologic data 1990–2015 and surveyed bathymetries 1998, 2010 and 2015, this study elucidates, before and after the commissioning of the dam, the alterations along the 500-km reach of the river. Two-dimensional numerical simulations are performed to predict future morphological changes by 2025. The analyses demonstrate that the impoundment modulates the seasonal flow discharges and traps an appreciable amount of sediment, resulting in enhanced erosion potential and coarsening of sediment. On a multi-year basis, the maximum discharge varies by a factor of 1.3 and the corresponding suspended load concentration and transport rate differ by a factor of 3.0 and 3.8, respectively. Combinations of surveyed and simulated bathymetries reveal its morphological responses to the changes. A general pattern of erosion is observed along the reach. In its upper 120 km, the process slows down towards 2025. In the middle 200 km, the erosion shifts, following the gradual impounding, to slight deposition, which then shifts back to erosion around September 2018. In the final 180 km, erosion continues without any sign of de-escalation, which is presumedly ascribed to tidal actions. The reach has not yet achieved a hydro-morphological equilibrium; the riverbed down-cutting is supposed to continue for a while. The combination of the field and numerical investigations provides, with the elapse of time, insight into the morpho-dynamics in the 500 km river reach.

Study of Electric Field Impact on Crystallization in Tunnel Drainage Pipes in Hard Water Area

To solve the problem of blockage of crystallization in tunnel drainage pipes in hard water area, electric field devices are designed and applied in the transversal tunnel drainage pipe according to the fundamental law of crystallization. Laboratory tests were carried out to test the crystallizing tunnel drainage pipe under the effect of electric field in order to study the law of electric field impact on crystallization in tunnel drainage pipes in hard water area. The test results indicate that the arranged circumferential and parallel plate electric field devices can form an electrical field within a narrow and small space inside the pipe and influence the ion movement in water and adsorption performance between crystals and the pipe. Under the condition of full flow, the amount of crystals in the ordinary pipe without electric field treatment increases progressively along water flow direction and remains relatively uniform later. The amount of crystals along the water flow direction of the pipe treated with circumferential and parallel plate electric fields presents signs of fluctuation in the early stage and then stableness later. The amount of crystals in the fluctuating section is higher and lower in the uniform section, and its uniform section length is longer than that in ordinary pipes. Under the condition of full current, crystallizing speed declines with elapse of running time. After the electric field is imposed, crystallizing acceleration progressively decreased to a relatively lower level. Comparing three voltages of 5 V, 12 V, and 24 V, the effect of scale inhibition under 5 V is superior. When water amount in the pipe varies, the effects of scale inhibition under different electric field modes are different. The electric field effect causes the changes of the external form of calcium carbonate crystal and its surface abrasion, porous crystal, and structural looseness.

Allocation Efficiency of Higher Education Resources in China

This paper uses the super-efficiency data envelopment analysis (DEA) model to measure the higher education resource allocation efficiency (HERAE) of 30 provinces from China 2005-2018, and analyzes the regional difference and dynamic evolution law of the HERAE with Theil index and kernel density estimation, respectively. The results show that: The HERAEs of most provinces are DEA effective, but the HERAEs of a few provinces are DEA ineffective, calling for further improvement to the allocation of higher education resources in these places. There was a certain difference in the HERAE trend between eastern, central, and western regions. In the sample period, eastern region had higher HERAE than central and western regions. With the elapse of time, the internal gap of HERAE decreased to different degrees in the three regions. Eastern region had the largest gap, followed in turn by central and western regions. In addition, China’s HERAEs were polarized in time. With the passage of time, the polarization of regional HERAEs slowly weakened.

Spatiotemporal Evolution and Influencing Factors of China’s Agricultural Environmental Efficiency

Taking the 30 Chinese provinces in 2000–2018 as the objects, this paper measures their agricultural environmental efficiencies (AEEs) with slack-based measure (SBM) containing an undesired output. Then, the features of the spatiotemporal evolution of AEE in China were explored on ArcGIS, and the factors affecting the AEE were analyzed with a geodetector. The results show that there is a huge provincial gap in AEE across China; most provinces with a high AEE belong to eastern coastal region, while most inland provinces had a relatively low AEE. Except for a few years, the AEEs in eastern, central, and western regions changed very slightly, and the eastern region had a higher AEE level than central and western regions. The results of spatiotemporal evolution show that, with the elapse of time, the high-AEE provinces gradually shifted to the inland; the AEE trend varied from province to province; the provinces were highly polarized in terms of AEE. The AEE is mainly affected by the following factors: fiscal expenditure, fertilizer intensity, pesticide intensity, and economic growth.

Evidence and Urgency Related EEG Signals during Dynamic Decision-Making in Humans.

A successful class of models link decision-making to brain signals by assuming that evidence accumulates to a decision threshold. These evidence accumulation models have identified neuronal activity that appears to reflect sensory evidence and decision variables that drive behavior. More recently, an additional evidence-independent and time-variant signal, called urgency, has been hypothesized to accelerate decisions in the face of insufficient evidence. However, most decision-making paradigms tested with fMRI or EEG in humans have not been designed to disentangle evidence accumulation from urgency. Here we use a face-morphing decision-making task in combination with EEG and a hierarchical Bayesian model to identify neural signals related to sensory and decision variables, and to test the urgency-gating model. Forty females and 34 males took part (mean age, 23.4 years). We find that an evoked potential time locked to the decision, the centroparietal positivity, reflects the decision variable from the computational model. We further show that the unfolding of this signal throughout the decision process best reflects the product of sensory evidence and an evidence-independent urgency signal. Urgency varied across subjects, suggesting that it may represent an individual trait. Our results show that it is possible to use EEG to distinguish neural signals related to sensory evidence accumulation, decision variables, and urgency. These mechanisms expose principles of cognitive function in general and may have applications to the study of pathologic decision-making such as in impulse control and addictive disorders.SIGNIFICANCE STATEMENT Perceptual decisions are often described by a class of models that assumes that sensory evidence accumulates gradually over time until a decision threshold is reached. In the present study, we demonstrate that an additional urgency signal impacts how decisions are formed. This endogenous signal encourages one to respond as time elapses. We found that neural decision signals measured by EEG reflect the product of sensory evidence and an evidence-independent urgency signal. A nuanced understanding of human decisions, and the neural mechanisms that support it, can improve decision-making in many situations and potentially ameliorate dysfunction when it has gone awry.

Enhanced surface hardening of hydrated concrete composite by strontium nitrate (Sr(NO3)2) aqueous solution

This study experimentally investigates the effects of strontium nitrate (Sr(NO3)2) aqueous solution on hardened concrete composite as a surface hardening method. Density, void content, water sorptivity, and surface abrasion resistance of the concrete mixture treated by Sr(NO3)2 solution were measured under diverse curing and treatment scenarios. The results showed that 30% Sr(NO3)2 aqueous solution increases the density by 1.0% and 2.2% and also decreases the void content by 7.4% and 14.4% with the water-cement ratio (w/c) of 0.5 and 0.4, respectively. Water sorptivity of the treated hardened concrete was decreased by 26.4% and 34.0% from the lithium silicate and sodium silicate treatments, respectively. In addition, the Sr(NO3)2 treatment increases the surface abrasion by 45% from the control specimen and about 25–30% from the two silicate-based treatments. X-ray diffraction (XRD), scanning electron microscope (SEM), energy-dispersive spectrometer (EDS), and attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR) were conducted to investigate the micro-morphologies, microstructure, and elemental characteristics. The results illustrate that (1) microstructures of hydrated cement matrix are densified, (2) portlandite (CH) in the matrix decreases as time elapses, (3) multiple types of hydrated aluminosilicate minerals (i.e. zeolites) are formulated, and (4) more subsequent polymerization related to C–S–H/C-A-S-H occurs. Lastly, the densifying and strengthening mechanisms of the hydrated cement by the Sr(NO3)2 treatment process are presented and discussed.

Changing Narratives of Survivors of the 2014 Hiroshima Landslide

The purpose of this study is to understand the fluidity of survivors’ narratives and to clarify the changes such narratives undergo after time has elapsed. Nineteen survivors of the landslide disaster that occurred on August 20, 2014 in Hiroshima City were interviewed twice-three years after the disaster and five years after the disaster-and the changes in the content of their narratives were analyzed. In addition, by analyzing the titles of newspaper articles that were published within one month of the disaster, the characteristics of narrative transformation were quantitatively identified. The narratives of disaster victims that were once accepted as “dominant stories” become “personalized” as “alternative stories” with the elapse of time, even though they are told by the same person. Comparisons of two interviews conducted at different times show that the word “evacuation” undergoes a significant change in context over time elapse, while the word “disaster” appears in a new context in the fifth-year interview. While social or community groups are the bearers of “socialized” memories, individuals are the bearers of “personalized” memories which are expected to continue to change as time elapses. It is necessary to examine what should be shared in order to utilize disaster victims’ memories to prevent and mitigate disasters, and how to such memories should be shared.

Toward Coexistence of Immigrants and Local People in Japan: Implications from Spatial Assimilation Theory

We investigate the validity of spatial assimilation theory (SAT), which predicts geographical dispersion of immigrants from ethnically concentrated areas to non-concentrated areas as time elapses. This can be tested by analyzing the concentration tendency among immigrants who arrive in Japan from overseas and relocate within the country. Using spatial models, we find that immigrants from overseas tend to move to ethnically concentrated regions in Japan, which is in line with SAT. By contrast, this trend substantially weakens with their subsequent domestic relocation, and it differs by national group. The results reveal slow assimilation among nationals from countries characterized as being low-income or culturally dissimilar from Japan. Based on these findings, we discuss potential deficiencies in a new immigration policy (2018), which has been designed to increase the number of immigrants and compensate for a labor shortage in Japan.

Adverse retention: Strategic renewal of guaranteed renewable term life insurance policies

AbstractThis study examines adverse retention using guaranteed renewable level term life insurance policies as a sample. No additional underwriting or physical examination is performed at the time of renewal. Our results show adverse retention exists in retention decisions. Further, we also find that the degree of adverse retention increases with age and policy amount and decreases with time elapses. Our results are robust with respect to the trend of before and after the renewal. During the prerenewal period, we find the prerenewal mortality rate is not higher than the nonrenewal mortality rate which is opposite to the evidence of postrenewal period. We also find correlation between “residuals of lapse” and “residuals of fatalities” is positive, also implying adverse retention exists. Most empirical studies on adverse selection often face problems such as the role of underwriting, entanglement of adverse selection, moral hazard, and regulations. Our study is free of these problems.

Mathematical analysis of COVID-19 by using SIR model with convex incidence rate

This paper is about a new COVID-19 SIR model containing three classes; Susceptible S(t), Infected I(t), and Recovered R(t) with the Convex incidence rate. Firstly, we present the subject model in the form of differential equations. Secondly, “the disease-free and endemic equilibrium” is calculated for the model. Also, the basic reproduction number R0 is derived for the model. Furthermore, the Global Stability is calculated using the Lyapunov Function construction, while the Local Stability is determined using the Jacobian matrix. The numerical simulation is calculated using the Non-Standard Finite Difference (NFDS) scheme. In the numerical simulation, we prove our model using the data from Pakistan. “Simulation” means how S(t), I(t), and R(t) protection, exposure, and death rates affect people with the elapse of time.

A multi-methodological approach to studying time-pressure in written translation: Manipulation and measurement

The effect of time pressure on task performance of written translation has been researched since the 1990s. However, little attention has been paid to the methodological issues of manipulating and measuring time pressure in these empirical studies. To bridge this gap, we propose a methodological framework involving diverse approaches to time-pressure manipulation and measurement. Specifically, in addition to objectively constraining the time frame for a task, we present three subjective time-pressure manipulation strategies: giving pre-task instructions about time, increasing participants’ intrinsic motivation for the task, and visualizing the elapse of time. Meanwhile, a range of feasible methods of time-pressure measurement is structured from the physiological, psychological and behavioural perspectives. This includes physiological measures such as galvanic skin response, heart rate, blood pressure, pupil dilation and salivary cortisol test, psychological measures such as psychometric instruments and retrospective questionnaires, and behavioural measures such as eye movements and keystroke activities. Based on a thorough survey of existing studies and the merits borrowed from neighbouring disciplines, this article aims to strengthen and enrich the methodology of time-pressure studies and benefit future translation research on relevant topics.

Does Transformational Leadership Promote Employee Perceptions of Ethical Leadership?: A Moderated Mediation Model of Procedural Justice and Power-Distance Orientation

This study examines three primary research questions: (1) if transformational leadership predicts followers’ subsequent perceptions of ethical leadership as time elapses; (2) which boundary conditions affect the relationship between justice perceptions, derived from the leader’s transformational characteristics, and ethical leadership; and (3) what the relationships are between ethical leadership and follower outcomes (job satisfaction, affective commitment and objective performance appraisals). Using the data collected through a three-wave survey over a two-year period, we found that transformational leadership was positively related to ethical leadership via procedural justice and this mediated relationship was stronger for followers with lower power-distance orientation

Supporting Real-Time Data Transmissions in Cognitive Radio Networks Using Queue Shifting Mechanism

As cognitive radio networks are conceptualized to make use of the opportunistic spectrum access, the users of these networks may face problems in satisfying their quality of service (QoS) requirements. Some services of users like real-time audio and video which cannot tolerate inter-packet delays will be affected more due to this. The problem occurs due to the non-availability of channels to these applications at some instants. This problem can be addressed if the available channels are judiciously distributed among the competing users. One such mechanism that dynamically allocates the competing users to multiple queues, and shifting the users to higher-level queues as the time elapses is introduced in this work. This is found to help the users of cognitive radio networks to communicate reasonably well even when fewer channels are available for opportunistic use. Results are indicated in terms of blocking probabilities of real-time data. Markov chain-based analysis and discrete event simulation studies are carried out.

Dynamic evolution and influencing factors of industrial green total factor energy efficiency in China

This paper sets up an evaluation index system (EIS) for industrial green total factor energy efficiency (IGTFEE), which contains undesired outputs. Next, the directional distance function (DDF) model was adopted to evaluate the IGTFEEs in 2003–2017 of 30 provincial administrative regions (provinces) in China. The results show that: The 30 provinces differed greatly in mean IGTFEE through the sample period. Most eastern coastal provinces had relatively high IGTFEE, while most inland provinces had undesirable IGTFEE. Eastern region had far better IGTFEE than central and western regions, while central and western regions had similar IGTFEEs. Through kernel density estimation (KDE), it is learned that the kernel density curves of IGTFEE in most years have only one peak, and moved to the left with the elapse of time, revealing the declining trend of China’s IGTFEE. The results of the Tobit model indicate that IGTFEE is greatly promoted by technological progress, opening-up, and environmental regulation, obviously suppressed by energy structure, and insignificantly promoted by human capital.