Narrow Results

A ground-breaking solution that combines solar thermal energy and lithium-bromide vapor absorption technology to produce energy-efficient cooling and heating is the Intelligent Solar Assist 1kW Lithium Bromide Vapor Absorption system. This cutting-edge system uses the sun’s energy to power the absorption cycle, offering environmentally friendly and economically viable thermal management. Solar thermal collectors, a lithium bromide absorption chiller, a thermal energy storage device, and sophisticated control algorithms comprise the system’s main parts. Sunlight is captured and converted by solar thermal collectors into thermal energy, which is then used to produce the necessary heat for the lithium bromide absorption chiller. This chiller uses the absorption refrigeration cycle to efficiently cool or heat the specified area or process. When intelligent control algorithms are incorporated, the system performs and operates more effectively and efficiently. These algorithms regulate the thermal energy storage unit and optimize the use of solar energy, delivering a constant and dependable supply of cooling or heating as needed. Advanced monitoring and diagnostics features are also built into the system, allowing for remote control and in-the-moment performance evaluation. Disadvantages are ethical issues, lack of generalization, interpretability and complexity, scalability and processing resources, and scientific agreement. A novel Chimp-based recurrent model (CbRM) has been planned to be designed to predict the desired efficiency from the Evacuated Tube Collector (ETC) to overcome this issue. Comparing the Intelligent Solar Assist system to conventional heating and cooling systems, several benefits must be had. It minimizes greenhouse gas emissions, lessens reliance on traditional energy sources, and promotes a more sustainable future. The system also saves money using solar energy, lowering power costs and enhancing energy efficiency. Moreover, the proposed system implementation is done in Matlab. The method achieves the high efficiency of ETC in the range of about 0.9% which increases by 0.3% and the higher rate of COP was about 9.5% which increases up to 6%, as the increased concentration level of the strong solution was about 6.5% it was nearly 5% increase. The parameters in the suggested model were compared to the current parameters for the comparison analysis, and it was discovered that the proposed model had superior presenting efficiency.

Highly crystalline ZnO nanopillars were successfully synthesized using the mist chemical vapor deposition (Mist-CVD) technique. This environmentally friendly and low-cost method operates under atmospheric pressure and low temperatures. By varying the growth temperature from 300C to 500^∘C, we demonstrated control over the structural, optical and morphological properties of ZnO. X-ray diffraction (XRD) analysis confirmed a transition in the preferential growth orientation from (100) to (002) as the temperature increased, with nanopillars showing a highly c-axis orientation at 450^∘C. SEM and AFM analyses revealed vertically aligned, homogeneously distributed nanopillars with high surface roughness, favorable for photocatalytic applications. Optical transmittance decreased with growth temperature, while the bandgap narrowed due to intrinsic defects. These findings highlight the potential of Mist-CVD for producing high-quality ZnO nanostructures tailored for advanced applications.

The temperature dependent binding energy of some low lying excited states for a compositional Quantum Well have been calculated for various impurity locations by extending the investigation of Elabsy.⁴ It has been observed that the temperature plays an important role in the binding energy of low lying excited states also.

In an optical tweezers system, the output signal of a photodiode quadrant detector and the temperature in a sample cell are two key factors for the quantitative measurements of mechanical properties of living biological objects such as cells, organelles and macro-molecules. In order to enhance the output of a quadrant detector and effectively control the temperature in a sample cell, the dependence of the temperature in the sample cell and the output of the quadrant detector for different illumination conditions are studied. The results show that appropriate illumination conditions can ensure both nearly constant temperatures in the cell and the desired output signal, which provides for the possibility of high precision and damage-free analysis of living biological objects.

This paper is to understand and model the thermomechanical response of the rotary forged WHA, uniaxial compression and tension tests are performed on cylindrical samples, using a material testing machines and the split Hopkinson bar technique. True strains exceeding 40% are achieved in these tests over the range of strain rates from 0.001/s to about 7,000/s, and at initial temperatures from 77K to 1,073K. The results show: 1) the WHA displays a pronounced changing orientation due to mechanical processing, that is, the material is inhomogeneous along the section; 2) the dynamic strain aging occurs at temperatures over 700K and in a strain rate of 10^-3 1/s; 3) failure strains decrease with increasing strain rate under uniaxial tension, it is about 1.2% at a strain rate of 1,000 1/s; and 4) flow stress of WHA strongly depends on temperatures and strain rates. Finally, based on the mechanism of dislocation motion, the parameters of a physically-based model are estimated by the experimental results. A good agreement between the modeling prediction and experiments was obtained.

The dynamic features of soliton transporting the bio-energy in the α-helix protein molecules with three channels under influences of temperature of systems and chain–chain interaction among these channels have been numerically studied by using the dynamic equations in a new model and the fourth-order Runge–Kutta method. This result obtained shows that the chain–chain interaction depresses the stability of the soliton due to the dispersed effect, but the stability of the soliton in the case of simultaneous motivation of three channels by an initial conditions is better than that in another initial condition. We also find from this investigation that the new soliton can transport steadily over 1000 amino acid residues in the cases of motion of long time of 120 ps, and retain their shapes and energies to travel towards the protein molecules after mutual collision of the solitons at the biological temperatures of 300 K. Therefore the soliton is very robust against the thermal perturbation of the α-helix protein molecules at 300 K. From the investigation of changes of features of the soliton with increasing temperature, we find that the amplitudes and velocities of the solitons decrease with increasing temperature of proteins, but the soliton disperses in the cases of higher temperature of 325 K and larger structure disorders. Thus we find that the critical temperature of the soliton occurring in the α-helix protein molecules is about 320 K. Therefore we can conclude that the soliton in the new model can play an important role in the bio-energy transport in the α-helix protein molecules with three channels at biological temperature, and the new model is possibly a candidate for the mechanism of this transport.

Thermodynamic deduction and experimental results both demonstrate that gravitation causes temperature gradient in an adiabatic system, i.e., gravithermal effect: The higher altitude the lower temperature.

In contrast to their exceptional mechanical properties, titanium and its alloys possess poor friction and wear characteristics. Nanocrystalline diamond (NCD) films appear to be a promising solution for their tribological problem due to their smooth surfaces and small grain size. However, the synthesis of a well adherent NCD film on titanium and its alloys is always complicated due to the different thermal expansion coefficients of the two materials, the complex nature of the interlayer formed during diamond deposition, and the difficulty in achieving very high nucleation density. In this work NCD thin films have been deposited on pure Ti substrates in a microwave plasma chemical vapor deposition (MWPCVD) reactor under fixed pressure and methane concentration in hydrogen but over a wide temperature range. The effects of depositing temperatures on the adhesion of films are evaluated using Rockwell indentation tests. It is found that by increasing the deposition temperature the films bonding deteriorates. The films synthesized are characterized by field emission scanning electron microscopy, atomic force microscopy, Raman spectroscopy, and X-ray diffraction.

The effects of parameters on temperatures in thin metal films heated by ultrafast-pulse laser are investigated in this paper. The time scale in which energy transfers from the electrons to lattice is on the order of a picosecond for metals. Therefore when the duration of ultrafast-pulse laser heating metal films is on the order of or shorter than a picosecond, a substantial nonequilibrium can occur between the electron and lattice temperature and the metal lattices stay almost thermally undisturbed in this highly nonequilibrium regime. A parabolic two-temperature heating model is employed to investigate thermal transport in thin metal films irradiated by ultrafast-pulse laser. Using the Laplace transform and assuming the thermal properties to be independent of temperature, a closed form solution of temperature in the thin film is provided. The effects of laser parameters and material properties on temperatures are also discussed.

In this paper, an improved integrated model of electromagnetic scattering for two dimensional fractal sea surface is built. Both geometrical fractal characteristic and permittivity characteristic of sea water are strictly considered, especially for the effects of salinity and temperature on the electromagnetic field scattered by sea water are added on. Finally, the calculated results from the new model are in accord with experimental results in terms of backscattering coefficient of sea water with no more than 2 dB error, which present higher precision than those traditional models. Thus, by using this model, the whole electromagnetic scattering characteristics of sea surface are obtained.

A new simple correlation based on the principle of corresponding state is proposed to estimate the temperature-dependent surface tension of normal saturated liquids. The correlation is a linear one and strongly stands for 41 saturated normal liquids. The new correlation requires only the triple point temperature, triple point surface tension and critical point temperature as input and is able to represent the experimental surface tension data for these 41 saturated normal liquids with a mean absolute average percent deviation of 1.26% in the temperature regions considered. For most substances, the temperature covers the range from the triple temperature to the one beyond the boiling temperature.

A new simple correlation based on the principle of corresponding state is proposed to estimate the temperature-dependent surface tension of normal saturated liquids. The new correlation contains three coefficients obtained by fitting 17,051 surface tension data of 38 saturated normal liquids. These 38 liquids contain refrigerants, hydrocarbons and some other inorganic liquids. The new correlation requires only the triple point temperature, triple point surface tension and critical point temperature as input and is able to well represent the experimental surface tension data for each of the 38 saturated normal liquids from the triple temperature up to the point near the critical point. The new correlation gives absolute average deviations (AAD) values below 3% for all of these 38 liquids with the only exception being octane with AAD=4.30%. Thus, the new correlation gives better overall results in comparison with other correlations for these 38 normal saturated liquids.

The mode competition in Er-doped fiber (EDF) Bragg grating (FBG) fiber laser is researched experimentally, the effect of the operating temperature of FBG on the oscillation mode is discussed. Experiment results demonstrate that the lasing oscillation mode is limited by the bandwidth of FBGs, which is a function of operation temperature, the temperature sensitivity is $1.29\times 10^{-5}{∕}^{\circ }\mathrm{\text{C}}$. When the operating temperature of the two FBGs is 25${}^{\circ }$C, the output power of $-23.69$ dBm and the lasing wavelength of 1549.96 nm with slope efficiency of 0.006% and threshold power of 154 mW are obtained.

In this paper, pure NiO and Cu-doped NiO nanoparticles are prepared by co-precipitation method. The electrical resistivity measurements by applying high pressure on pure NiO and Cu-doped NiO nanoparticles were reported. The Bridgman anvil set up is used to measure high pressures up to 8 GPa. These measurements show that there is no phase transformation in the samples till the high pressure is reached. The samples show a rapid decrease in electrical resistivity up to 5 GPa and it remains constant beyond 5 GPa. The electrical resistivity and the transport activation energy of the samples under high pressure up to 8 GPa have been studied in the temperature range of 273–433 K using diamond anvil cell. The temperature versus electrical resistivity studies reveal that the samples behave like a semiconductor. The activation energies of the charge carriers depend on the size of the samples.

The present study deals with first-principles calculations of the thermal properties of ZnTe in the two phases namely, zinc-blende and wurtzite. The calculations are mainly performed using the density functional theory with the local density approximation and response-function calculations. The full phonon dispersions throughout the Brillouin zone are presented. The temperature dependence of the lattice parameters, bulk modulus, entropy and heat capacity are examined and discussed. Our findings agree reasonably well with those available in the literature.

Molecular dynamics simulations of crystal growth of SiC in the reduced temperature range of 0.51–1.02 have been carried out. In particular, the relationship between the growth rate and the reduced temperature has been investigated by the simulations. The results show that the growth rate increases first with the temperature and then decreases dramatically after passing through a maximum. Calculations of the growth rate according to the Wilson–Frenkel model have been applied to the present system, with the required parameters of the activation energy for atomic diffusion and the free energy changes calculated by molecular dynamics simulations. The temperature dependence of the growth rate, calculated by molecular dynamics, agrees with the prediction of Wilson–Frenkel model, indicating that the crystal growth of SiC is a kind of diffusion limited growth.

In this paper, we analyzed the ability of Lielmezs–Herrick (LH) correlation for the temperature-dependent surface tension of 28 hydrocarbons. We found that compared with other published correlations, the original LH correlation stands well only for four fluids. By using new data in REFPROP database, we refitted the two parameters of LH correlation. Two sets values are obtained. One is the updated corresponding state LH correlation, which is fluid independent. The other is the two-parameter LH correlation, which is fluid dependent. We found that the former clearly improves the accuracy of the original LH correlation and the latter is the best among all of the correlations we know.

Recently, Haj-Kacem et al. proposed an equation modeling the relationship between the two parameters of viscosity Arrhenius-type equations [Fluid Phase Equilibria383, 11 (2014)]. The authors found that the two parameters are dependent upon each other in an exponential function form. In this paper, we reconsidered their ideas and calculated the two parameter values for 49 saturated pure fluids by using the experimental data in the NIST WebBook. Our conclusion is different with the ones of Haj-Kacem et al. We found that (the linearity shown by) the Arrhenius equation stands strongly only in low temperature range and that the two parameters of the Arrhenius equation are independent upon each other in the whole temperature range from the triple point to the critical point.

Due to its geometry simplicity, the forces of thin liquid film are widely investigated and equivalently employed to explore the phys–chemical properties and mechanical stability of many other surfaces or colloid ensembles. The surface tension of bulk liquid (${\sigma }_{\infty }$) and film tension ($\gamma$) are the most important parameters. Considering the insufficiency of detailed interpretation of film tension under micro-scale circumstances, a method for film tension was proposed based on numerical modeling. Assuming surface tension at different slab thicknesses being identical to the surface tension of film, the surface tension and disjoining pressure were subsequently used to evaluate the film tension based on the derivation of film thermodynamics, and a decreasing tendency was discovered for low temperature regions. The influence of saline concentration on nano-films was also investigated, and the comparison of film tensions suggested that higher concentration yielded larger film tension, with stronger decreasing intensity as a function of film thickness. Meanwhile, at thick film range (15–20 nm), film tension of higher concentration film continued to decrease as thickness increase, however it arrived to constant value for that of lower concentration. Finally, it was found that the film tension was almost independent on the film curvature, but varied with the thickness. The approach is applicable to symmetric emulsion films containing surfactants and bi-layer lipid films.

Binding energies of the heavy hole and light hole exciton in a quantum well with Pöschl–Teller (PT) potential composed of GaAs have been studied variationally within effective mass approximation. The effects of pressure and temperature on exciton binding energy are analyzed individually and also simultaneously for symmetric and asymmetric configuration of the well. The results show that exciton binding energy (i) decreases as the well width increases, (ii) increases with pressure and (iii) decreases with temperature. Simultaneous effects of these perturbations lead to more binding of the exciton. The results are compared with the existing literature.