Influence Of Interaction Effects Research Articles

Influence of interactive effects on long-term population trajectories in multispecies reintroductions.

Reintroduced populations are typically considered to progress through establishment, growth, and regulatory phases. However, most reintroduction programs do not monitor intensively enough to test this conceptual model. We studied population indices derived from track activity of 4 threatened species (greater bilby [Macrotis lagotis], burrowing bettong [Bettongia lesueur], greater stick-nest rat [Leporillus conditor], and Shark Bay bandicoot [Perameles bougainville]) over 23years after multiple reintroductions of each species in arid Australia. We compared population trajectories among species and investigated the effect of time and environmental variables. All species bred immediately after release, and the growth phase lasted 3-16years, varying markedly among but not within species. The end of the growth phase was characterized by an obvious peak in population density followed by either a catastrophic decline and sustained low density (bettongs), a slow decline to extirpation after 20years (stick-nest rat), or a slight decline followed by irregular fluctuations (bilby and bandicoot). Minor fluctuations were related to environmental variables, including 12-month cumulative rainfall and lagged summer maximum temperatures. Three of the 4 species did not reach a regulation phase, even after 23years, possibly due to interspecific competition and trophic cascades triggered by predator removal and multispecies reintroductions. Bilbies and bandicoots exhibited a second growth phase 18years after reintroduction, likely caused by high rainfall and increased resources following the population crash of overabundant bettongs. Our results suggest that assemblages within multispecies reintroductions demonstrate high variability in population trajectories due to interactive effects. Intensive monitoring to assess population viability may require decades, particularly where multiple species are reintroduced, release sites are confined, and the climate is unpredictable. Intensive monitoring also allows for adaptive management to prevent precipitous population declines. Practitioners should not assume reintroduced species pass through predictable postrelease population phases or that viability is assured after a certain period.

A comparison of two wave energy converters’ power performance and mooring fatigue characteristics – One WEC vs many WECs in a wave park with interaction effects

The production of renewable energy is key to satisfying the increasing demand for energy without further increasing pollution. Harnessing ocean energy from waves has attracted attention due to its high energy density. This study compares two generations of floating heaving point absorber WEC, WaveEL 3.0 and WaveEL 4.0, regarding their power performance and mooring line fatigue characteristics, which are essential in, e.g., LCoE calculations. The main differences between the two WECs are the principal dimensions and minor differences in their geometries. The DNV software SESAM was used for simulations and analyses of these WECs in terms of buoy heave motion resonances for maximising energy harvesting, motion characteristics, mooring line forces, fatigue of mooring lines, and hydrodynamic power production. The first part of the study presents results from simulations of unit WEC in the frequency domain and in the time domain for regular wave and irregular sea state conditions. A verification of the two WECs’ motion responses and axial mooring line forces is made against measurement data from a full-scale installation. In the second part of the study, the influence of interaction effects is investigated when the WECs are installed in wave parks. The wave park simulations used a fully-coupled non-linear method in SESAM that calculates the motions of the WECs and the mooring line forces simultaneously in the time domain. The amount of fatigue damage accumulated in the mooring lines was calculated using a relative tension-based fatigue analysis method and the rainflow counting method. Several factors that influence the power performance of the wave park and the accumulated fatigue damage of the mooring lines, for example, the WEC distance of the wave park, the sea state conditions, and the direction of incoming waves, are simulated and discussed. The study's main conclusion is that WaveEL 4.0, which has a longer tube than WaveEL 3.0, absorbs more hydrodynamic energy due to larger heave motions and more efficient power production. At the same time, the accumulated fatigue damage in the moorings is lower compared to WaveEL 3.0 if the distance between the WECs in the wave park is not too short. Its motions in the horizontal plane are larger, which may require a larger distance between the WEC units in a wave park to avoid losing efficiency due to hydrodynamic interaction effects.

Optimization of Extraction of Polyphenol from Panax Quinquefolius L. Using Central Composite Design/Response Surface Methodology

AbstractCentral composite design and response surface methodology are adopted to explore the extraction process of polyphenols from Panax quinquefolius L., including the extraction time, extraction temperature, ethanol concentration, and the influence of interaction effects, and establish the multiple regression model. The results show that the optimal extraction conditions for polyphenols of P. quinquefolius L. are 61 °C of extraction temperature, 38 min of extraction time, 48% of ethanol concentration and the polyphenol yield is 79.53 ± 0.43 gallic acid equivalent (mg GAE g−1). The actual polyphenols extraction yield of P. quinquefolius L. is close to the predicted value, which is 99.21% of the predicted value. The extraction method is simple, low cost and can be used to extract polyphenols from P. quinquefolium L.

Influence of Interaction Effects of Emotional Labor and Burnout on the Turnover Intention of Nursery Workers Based on Competing Value Frameworks Model

Influence of Interaction Effects of Emotional Labor and Burnout on the Turnover Intention of Nursery Workers Based on Competing Value Frameworks Model

The relationship of violent behavior with polymorphism of norepinephrine transporter gene, childhood abuse and their interaction effect in male adolescents

Objective To explore the relationship between the rs3785143 polymorphism of norepinephrine transporter gene, and investigate the influence of interaction effect between NET gene polymorphism and childhood abuse in adolescents with violent behavior. Methods Adolescent male offenders were divided into violent group (124 samples) and nonviolent group (120 samples). The rs3785143 polymorphisms of NET gene were measured by used SNaPshot SNP technology in 244 samples. Chi-square test was used to compare the distribution difference between three groups of each gene type and the allele frequency distribution. Results ①There was no statistically significant difference among violent group and nonviolent group in the genotype and allele frequencies of rs3785143 polymorphism (χ2=0.753, 0.022; all P>0.05). ②64.5% violent adolescents have experience of childhood abuse, and 35.5% had no history of abuse; 48.3% nonviolent adolescents have experience of childhood abuse, and 51.7% had no history of abuse(χ2=6.50, P 0.05) 95%CI(0.457-4.739)). Conclusions The NET gene polymorphism is not associated with violent behavior in male adolescents, and there was not interaction between NET gene polymorphism and childhood abuse. Key words: Adolescents; Violent behavior; Norepinephrine transporter

Tests of Adsorption of Amino-acids on the Natural Phosphate of the El Hadba Layer, Djebel Onk, Algeria

Adsorption tests were carried out in static mode, on natural phosphate samples both in a raw state and after processing. Various techniques of analyses were used (i) to characterize the material adsorbing on the granulo-chemical and thermo-mineralogical levels, (ii) to evaluate the performances of the process of adsorption used in relation to the existing mineralogical species, in phosphatic and gangue elements, (iii) to evaluate incubation condition in ions PO43-, carboxylate grouping and steric obstruction effect on lateral chains of adsorbates. This effect is significantly affected by the composition of the incubation medium. Thus, the fractions low in phosphate ions appeared definitely more effective. The adsorption isotherms highlight a good correlation between experimental points and values predicted by Temkin model, confirming the influence of interactive effects on the used adsorbates. Study of the mechanisms of adsorption and the transfer mode of matter was carried out using the linear shape of the isotherm models, their respective correlation coefficients, the speed constants and the diffusion coefficients for the kinetic models based on reaction and diffusion.

Investigation of accurate imaging of the defects in composite materials using ultrasonic air-coupled technique

In this paper air-coupled ultrasonic investigation of delamination type defects in GLARE3-3/2 composite material is presented. An air-coupled ultrasonic measurement technique has a great potential for investigation of those materials in manufacturing and maintenance. An important advantage of this technique is that investigations can be performed without couplants and therefore various materials that can absorb liquids (honeycombs, porous) can be tested. The objective of the work was to investigate the interaction of the ultrasonic wave with delamination type defect in GLARE3-3/2 composite material and to determine influence of interaction effects on accuracy of the defect size measurement. Numerical and experimental investigation was carried-out in the through transmission mode. Results of numerical investigation and experimental verification of interaction of the ultrasonic wave are presented. Estimation of accuracy of the measurement of the delamination defect sizes is also presented.

A Brownian Model for Recurrent Earthquakes

We construct a probability model for rupture times on a recurrent earthquake source. Adding Brownian perturbations to steady tectonic loading produces a stochastic load-state process. Rupture is assumed to occur when this process reaches a critical-failure threshold. An earthquake relaxes the load state to a characteristic ground level and begins a new failure cycle. The load-state process is a Brownian relaxation oscillator. Intervals between events have a Brownian passage-time distribution that may serve as a temporal model for time-dependent, long-term seismic forecasting. This distribution has the following noteworthy properties: (1) the probability of immediate rerupture is zero; (2) the hazard rate increases steadily from zero at t = 0 to a finite maximum near the mean recurrence time and then decreases asymptotically to a quasi-stationary level, in which the conditional probability of an event becomes time independent; and (3) the quasi-stationary failure rate is greater than, equal to, or less than the mean failure rate because the coefficient of variation is less than, equal to, or greater than \batchmode \documentclass[fleqn,10pt,legalpaper]{article} \usepackage{amssymb} \usepackage{amsfonts} \usepackage{amsmath} \pagestyle{empty} \begin{document} \(1{/}\sqrt{2}{\approx}0.707\) \end{document}. In addition, the model provides expressions for the hazard rate and probability of rupture on faults for which only a bound can be placed on the time of the last rupture. The Brownian relaxation oscillator provides a connection between observable event times and a formal state variable that reflects the macromechanics of stress and strain accumulation. Analysis of this process reveals that the quasi-stationary distance to failure has a gamma distribution, and residual life has a related exponential distribution. It also enables calculation of “interaction” effects due to external perturbations to the state, such as stress-transfer effects from earthquakes outside the target source. The influence of interaction effects on recurrence times is transient and strongly dependent on when in the loading cycle step perturbations occur. Transient effects may be much stronger than would be predicted by the “clock change” method and characteristically decay inversely with elapsed time after the perturbation.

Static structure factor of polymerlike micelles: Overall dimension, flexibility, and local properties of lecithin reverse micelles in deuterated isooctane

We report a systematic investigation of the static structure factor $S(q,c)$ of polymerlike reverse micelles formed by soybean lecithin and trace amounts of water in deuterated isooctane using small-angle neutron scattering and static light scattering. The experimental data for different concentrations in the dilute and semidilute regime cover approximately three decades of scattering vectors. The data have been analyzed using polymer renormalization-group theory and a nonlinear least-squares fitting procedure based upon a numerical expression for the single chain scattering function of a wormlike chain with excluded-volume effects. Furthermore, the influence of interaction effects on the static structure factor have been successfully examined within a modified random-phase approximation. Additional information on the local scale has been extracted by applying indirect Fourier transformation and square-root deconvolution techniques. We demonstrate that we can determine structural properties such as the micellar cross-section profile and flexibility as well as quantitatively incorporate the influence of micellar growth and excluded-volume effects on $S(q,c).$

Zero-field-cooled magnetization and initial susceptibility of magnetic particle systems

General expressions for the zero-field-cooled magnetization and the initial susceptibility (χ) of magnetic particle assemblies are set up. These equations are evaluated analytically by specifying the distribution of geometric and magnetic properties of the particles. We derive relations between χ and the magnetic viscosity. The influence of interaction effects is examined.

Analysis of multiple cracks in an infinite plate under arbitrary crack surface tractions

Based on the analytical solution derived for a crack under arbitrary crack surface tractions an alternating method is presented to analyze two-dimensional mixed-mode fracture problems with multiple cracks which are arbitrarily distributed in an infinite plate. During the iterative solution process the reversed residual stresses at the location of fictitious cracks induced by other cracks are repeatedly evaluated and treated as new applied loading until the residual stresses on each crack surface are negligible. The influence of interaction effects among cracks on the determination of stresses and deformations is studied in detail. Several numerical example are solved to demonstrate the validity of the method. Good agreement between the computed stress intensity factors and referenced solutions shows the accuracy and efficiency of the this work.