Gas/particle (G/P) partitioning is an important influencing factor for the environmental fate of semi-volatile organic compounds (SVOCs). The G/P partitioning of polycyclic aromatic hydrocarbons ...(PAHs) is an integrated complex process due to its formation and growth concurrently with particles. Based on the large dataset of gaseous and particulate samples in a wide ambient temperature range of 50 °C, the simple empirical equations based on ambient temperature were established to predict the G/P partitioning quotient (KP) of PAHs at the temperature range from 252 K to 307 K (−21 °C to 34 °C). The performance of the empirical equations was validated by comparison with the monitoring KP of PAHs worldwide. The empirical equations exhibited good performance for the prediction of KP of PAHs based on ambient temperature. Two deviations with the prediction lines of the previous G/P partitioning models from the monitoring data of KP were observed. It was found that the deviations might be attributed to some non-considered influencing factors with the previous G/P partitioning prediction models. Therefore, further research should be conducted to study the mechanism of the G/P partitioning of PAHs, and more influencing factors should be introduced into the establishment of G/P partitioning models of PAHs. In summary, the result of the present study provided a convenient method for the prediction of KP of PAHs, which should be useful for the study of environmental fate of PAHs in atmosphere.
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•Influence of temperature on the G/P partitioning of PAHs was studied.•Simple empirical equations based on ambient temperature were established.•G/P partitioning quotient (KP) of PAHs from 252 K to 307 K can be predicated.•Two deviations of G/P partitioning models from monitoring KP were observed.
Gas insulated switchgear (GIS) in service may tolerate large temperature changes, which leads to uncertainty in the evaluation of the partial discharge (PD) signal. To clarify the influence of ...temperature on the discharge signals of GIS insulation void defects, this paper proposes a multiscale fusion simulation method and used experiments to verify it. This method combines the streamer simulation at the micro level and the circuit simulation model at the macro level, and a more accurate simulation signal of GIS insulation void PDs under the influence of temperature can be obtained. Experiments have also been carried out, and a PDs detection experiment platform that can be set in different temperature environments was built. The discharge signals at different temperatures were obtained follow IEC60270. Finally, by combining analyses of simulation and experimental data, the law of the influence of temperature on the PD signal of GIS insulation voids was summarized, and the mechanism of the influence was analyzed. The results showed that the multiscale fusion simulation method of GIS insulation void PD signals proposed in this paper is consistent with the experimental results, which can provide a reference for the digital twin model of power equipment status.
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Droplet volume and temperature affect contact angle significantly. Phase change heat transfer processes of nanofluids – suspensions containing nanometre-sized particles – can only be ...modelled properly by understanding these effects. The approach proposed here considers the limiting contact angle of a droplet asymptotically approaching zero-volume as a thermophysical property to characterise nanofluids positioned on a certain substrate under a certain atmosphere.
Graphene oxide, alumina, and gold nanoparticles are suspended in deionised water. Within the framework of a round robin test carried out by nine independent European institutes the contact angle of these suspensions on a stainless steel solid substrate is measured with high accuracy. No dependence of nanofluids contact angle of sessile droplets on the measurement device is found. However, the measurements reveal clear differences of the contact angle of nanofluids compared to the pure base fluid.
Physically founded correlations of the contact angle in dependency of droplet temperature and volume are obtained from the data. Extrapolating these functions to zero droplet volume delivers the searched limiting contact angle depending only on the temperature. It is for the first time, that this specific parameter, is understood as a characteristic material property of nanofluid droplets placed on a certain substrate under a certain atmosphere. Together with the surface tension it provides the foundation of proper modelling phase change heat transfer processes of nanofluids.
For the analysis of the process of partial demagnetization of permanent magnets (PMs) in electric machines, a field model of coupled electromagnetic and thermal phenomena was proposed. In the ...proposed approach the non-linearity of the magnetic circuit, the effect of temperature on the magnetic, electrical and thermal properties of the materials as well as the developed method for modeling the process of partial demagnetization of the PMs were taken into account. In order to verify the usefulness and effectiveness of the developed algorithm as well as software for analyzing the impact of temperature and the process of partial demagnetization of the magnets on the operation of a PM motor, the results of calculations were compared with the results of experimental studies. The experimental tests were carried out on a specially designed and constructed measuring test stand. The results of the research on the process of partial demagnetization of magnets in the line start permanent magnet synchronous motor (LSPMSM) are presented and the conclusions resulting therefrom have been formulated.
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•Anammox bacterial was enriched in SBR system under lower nitrogen load.•15–26 °C constitutes breaking point for nitrogen removal in the Anammox SBR.•Temperature variation can affect ...Anammox bacteria community structure.•Ca. Kuenenia is more adaptive to varied temperature than Ca. Brocadia.
The nitrogen removal performance and microbial communities of an Anammox sequencing batch reactor (SBR) was studied under varied temperatures with a lower nitrogen loading rate (NLR) about 0.28 kgN/m3/d. Results showed that the temperature could influence the nitrogen removal performance and the community structure in the Anammox SBR system. Under lower temperatures, both the nitrogen removal efficiencies and Anammox activity were in lower levels. When temperature was raised again, the Anammox activity recovered accordingly. When the temperature dropped from 33 ± 1 °C to15 °C, the dominant Anammox bacteria shifted from Ca. Brocadia to Ca. Kuenenia in the sludge. When the temperature returned over, the abundance of Ca. Brocadia recovered, while the Ca. Kuenenia was still the dominant Anammox bacteria. This indicated that Ca. Kuenenia is more adaptable to low temperature environment than Ca. Brocadia under low NLR with temperature variation.
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•Shown that chemical composition and band gap in CdxZn1-xS/PVA nanocompounds depends from grown temperature.•The change in particle size under the influence of temperature is ...associated with the coalescence process of nanoparticles..•With increase in concentration of Cd2+ ions in solution, particle size has grown due to increase in CdZnS lattice parameters.•The band gaps of CdZnS/PVA samples depends on the chemical composition, formation conditions and annealing temperatures.•Increase in formation temperature entails the growth in dielectric permittivity of samples.
In this work, we present the role of reaction temperature in formation and characterization of CdxZn1-xS/PVA nanocomposites. CdxZn1-xS/PVA (x = 0.1, 0.2, 0.8) have been prepared by SILAR method. In the process of nanoparticles growth, the method of simultaneous adsorption of cations from electrolyte precursors was used. The obtained samples were investigated by X-ray diffraction (XRD), Scanning electron microscopy (SEM), Energy-dispersive X-ray spectroscopy (EDX), Ultraviolet-visible spectrophotometer (UV-–VIS) and E7-20 (MNIPI-Belarus) devices. The analyses of XRD pattern show that, in room temperature with increasing of concentration of Cd2+ ions, the size of particles increasing. The mechanism of formation essentially depends from temperature of crystallization medium. The particles size were determined from XRD results by Debye Scherer equation. Dielectric and optical properties were used to characterize the final nanocomposite films before and after thermal annealing. The SEM images of sample were obtained at two different synthesis temperature. The elemental analyses used for analyses growth mechanism of ternary CdZnS nanoparticles.
•The governing equations of the VE Mindlin plates in the Laplace domain are derived•The simple procedure for dynamic characteristics of VE Mindlin plates is proposed.•The simple method to include the ...temperature influence is included.•Parametric studies of the dynamic characteristics are carried out.
This paper is devoted to geometrically linear free vibrations of viscoelastic (VE) Mindlin plates. The governing equations are derived in the Laplace domain. A simple way to take into account the influence of temperature on the damping properties is included using the frequency-temperature superposition principle. The novel approach to the solution of the non-linear problem of free vibrations of VE plates significantly simplifies the procedure reducing it to a linear eigen-value problem and a simple algebraic non-linear equation with one unknown. Several numerical examples involving varying physical parameters of the model are solved and the results are discussed.
•ICR behavior of conical nanopores modeled, taking account of electroosmotic flow.•Neglecting electroosmotic flow can yield ca. 90% deviation in the degree of ICR.•Mechanisms for the influence of ...temperature on ICR effect proposed.•3-D plot correlating ICR effect with key factors prepared for thermal gate design.
Considering various potential applications of charged nanochannels, we studied theoretically the electric field driven ion transport in a conical nanochannel connecting two large, identical reservoirs filled with an aqueous KCl solution. Taking account of the effect of electroosmotic flow (EOF), the associated electrokinetic behaviors under various conditions are examined, focusing on the influences of the temperature and the bulk salt concentration on the degree of ionic current rectification (ICR) and the conductance. Assuming that the bulk salt concentration ranges from 1 to 1000 mM and temperature from 278 to 313 K, we show that neglecting the EOF effect will either underestimate or overestimate the ionic current, and can lead to ca. 90% deviation in the degree of ICR. In general, the higher the temperature the greater the conductance and the less significant the ICR effect, and the degree of this effect has a local maximum as the bulk salt concentration varies. A three dimensional plot correlating the ICR effect with the bulk salt concentration and the temperature is prepared for the design of the nanochannel-based thermal gates for ionic transport.
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A theoretical model has been developed that adequately describes the formation of oxygen vacancies in ceria at the nanoscale. The intrinsic regime of vacancy formation under equilibrium conditions is ...considered. An analytical relation describing the dependence of the enthalpy of oxygen vacancy formation on the characteristic size and morphology of nanoobjects is derived. This made it possible to perform quantitative calculations of the concentration of oxygen vacancies in cerium oxide nanoobjects for a wide range of their characteristic sizes, morphology and temperature. It is shown that the size effect becomes noticeable for the concentration of surface and bulk oxygen vacancies, approximately, at the characteristic sizes of nanoobjects less than 20 nm and 30 nm, respectively. The effect of morphology on the concentration of oxygen vacancies increases with a decrease in the characteristic size of nanoobjects. This effect is more significant for the concentration of bulk oxygen vacancies than for the concentration of surface oxygen vacancies. In addition, the morphological effect and the size-effect decrease with increasing temperature. In thin films of ceria, the concentration of bulk oxygen vacancies at 300 K is 1011 and 103 times lower than that of spherical ceria nanoparticles, with their characteristic size of 4 nm and 40 nm, respectively. At 1000 K, this ratio is 3∙103 and 7, respectively. Thus, the oxygen storage capacity is higher for spherical nanoparticles and increases with a decrease in their characteristic size.
•The size and morphological dependence of the enthalpy of oxygen vacancy formation in CeO2−δ is described analytically.•The size effect is noticeable at the sizes of nanoobjects less than 20 and 30 nm for the surface and bulk, respectively.•The effect of morphology on the concentration of oxygen vacancies increases with a decrease in the size of nanoobjects.•The size and morphological effect are more significant for bulk oxygen vacancies than for the surface oxygen vacancies.•It is also shown that the size-effect and the morphological effect decrease with increasing temperature.
The paper justifies the validity of analyzing the impact of temperature and the process of partial demagnetization of magnets on the operating parameters of machines. To analyze this impact, a field ...model of coupled electromagnetic and thermal phenomena in a permanent magnet synchronous motor was proposed. The non-linearity of the magnetic circuit, the effect of temperature on the magnetic, electrical and thermal properties of the materials as well as the developed method of modeling the process of partial demagnetization of the magnet were taken into account. Based on this model, an algorithm and software were developed to analyze the effect of temperature and the process of partial demagnetization of magnets on the work of the line start permanent magnet synchronous motor (LSPMSM). The elaborated software was used to study the effect of temperature during the motor starting phase on the magnetization state of the magnets after the start-up process. The calculation results were compared to the results of experimental studies. The experimental tests were carried out on a specially constructed test stand. The results of the research on the process of partial demagnetization of the magnets are presented and the conclusions resulting therefrom formulated.
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