Entropy Variation Research Articles

Mathematical modeling and thermodynamic properties in the drying of citron watermelon seeds

ABSTRACT Citron watermelon is an agricultural product of excellent economic potential. Its seeds are widely used for oil extraction, serving as an energy source, showing nutritional characteristics that make them a suitable product to be studied. Thus, the objective was to characterize citron watermelon seeds regarding their physicochemical composition, in addition to determining drying kinetics, fitting mathematical models to the data, and determining the effective diffusivity coefficients and thermodynamic properties. The seeds were dried in a convective dryer, varying the drying temperature, with air velocity of 1.0 m s-1. With the increase in drying temperature, there were reductions in moisture content, water activity (aw), ash concentration, total titratable acidity, lipids and reducing sugar. Citron watermelon seeds are rich in lipids and ash, have low sugar concentration and low acidity; their drying kinetics was very well described by the Two Terms and Approximation of Diffusion models, followed by the models of Midilli and Page, which resulted in acceptable fits. Effective diffusivity accompanied the increase in drying temperature, and this behavior was well fitted by an Arrhenius-type equation. Enthalpy and entropy variations were reduced with drying temperature, with increments in Gibbs free energy.

Dialectical Behavior Group Therapy for Adolescents and Parents: Analysis of Answer Entropy

Introduction: The work’s purpose is to study the group behavior of the members of six therapeutic groups, two closed and four slow-open, involved in a Dialectical Behavior Therapy (DBT) class. We studied three groups of teenagers and three of their parents or legal guardians. We confronted the groups’ responses to an “absurd questionnaire” submitted during the training, and we concentrated on the entropy of the response. Methods: The research method consists of a questionnaire administered to training attendees. Participants chose one picture in each one of 50 couples (“absurd questionnaire”). In this work, we could propose a questionnaire to each trainee before the first meeting of the groups. We studied the longitudinal evolution of entropy, and we also compared the six groups according to their first picture choices and their evolution, the changes in the choices, the number of changes (flux), and the divergence or convergence toward the initial answer (focus). We have also analyzed the frequency of entropy variation via the Fourier transform. Results: We find the maximum statistical difference between parents’ and adolescents’ closed groups. The entropy trend is steeper in the adolescent closed group. The entropy evolution depends more on the age group (parents or adolescents) in closed and slow-open groups than on the setting. We found an increase in entropy from the beginning to the end of the training in all the groups. Conclusions: The clear outcome of this study is the augmentation in entropy in all the groups regardless of the settings (closed or slow-open) and possibly a similar entropy’s dominant oscillation frequency, that is, the number of complete cycles in the training interval, regardless of the type of group and the training duration.

Measurements of Energy Dissipation in the Electron Diffusion Region

AbstractAn outstanding question in magnetic reconnection is how the energy being dissipated in the diffusion region. This paper evaluates the quasi‐viscous dissipation in the electron diffusion region (EDR) at Earth's magnetopause by the observations from the Magnetospheric MultiScale mission. We compared two fluid parameters, J·Eˊ and Pi‐D, and found that J·Eˊ and Pi‐D have opposite signs in about half of the examined EDRs. The gyrotropic effect is more important than the nongyrotropic effect for the viscous dissipation in the diffusion region. One intriguing discovery is that electrons are cooled rather than heated in a large portion of the EDRs, with the compressional effect dominates over the viscous effect in electron thermodynamics. Enthalpy flux flowing into or out from the EDR greatly affect the electron entropy variation within the EDR. This study is an important step toward fully resolving the dissipation mystery in reconnection.

Quantum superposition of thermodynamic evolutions with opposing time\u2019s arrows

Microscopic physical laws are time-symmetric, hence, a priori there exists no preferential temporal direction. However, the second law of thermodynamics allows one to associate the “forward” temporal direction to a positive variation of the total entropy produced in a thermodynamic process, and a negative variation with its “time-reversal” counterpart. This definition of a temporal axis is normally considered to apply in both classical and quantum contexts. Yet, quantum physics admits also superpositions between forward and time-reversal processes, whereby the thermodynamic arrow of time becomes quantum-mechanically undefined. In this work, we demonstrate that a definite thermodynamic time’s arrow can be restored by a quantum measurement of entropy production, which effectively projects such superpositions onto the forward (time-reversal) time-direction when large positive (negative) values are measured. Finally, for small values (of the order of plus or minus one), the amplitudes of forward and time-reversal processes can interfere, giving rise to entropy-production distributions featuring a more or less reversible process than either of the two components individually, or any classical mixture thereof.

Influence of V and Zn in FeCrCuMnTi High-Entropy Alloys on Microstructures and Uniaxial Compaction Behavior Prepared by Mechanical Alloying

The densification behavior of FeCrCuMnTi (HEA1), FeCrCuMnTiV (HEA2), and FeCrCuMnTiVZn (HEA3) equiatomic high-entropy alloys (HEAs) was explored using different uniaxial quasi-static controlled compaction (1 mm/min). These HEAs were synthesized by mechanical alloying (MA, speed: 300 rpm, BPR: 10:1, time: 25 h). Various phase formations, structural characteristics (crystallite size, lattice strain, and lattice constant), thermo-dynamic calculations, powder surface morphologies, detailed microstructural evolutions, and chemical compositions were examined using X-ray diffraction, high-resolution scanning electron microscopy, and high-resolution transmission electron microscopy. The XRD results revealed the formation of multiple solid solutions (FCC, BCC, and HCP) due to the variation in entropy, and the presence of high-strength elements (Cr, Ti, and V) in the developed HEA alloys. The synthesized powders were consolidated into bulk green samples with different compaction pressures starting from 25 to 1100 MPa under as-milled and milled under stress recovery conditions (150 °C, 1 h). The incorporation of V in the FeCrCuMnTi HEA resulted in improved densification due to a greater reduction in particle size, and high configurational entropy. Furthermore, the stress-recovered powder samples produced more relative density owing to the elimination of lattice strain. Several linear and non-linear compaction models were applied to predict densification behavior. The non-linear Cooper and Eaton model produced the highest regression coefficients compared to the other models.

Complexity for holographic superconductors with the nonlinear electrodynamics

We systematically study the complexity of a strip-shaped subregion in a fully backreacted holographic model of a superconductor with the nonlinear electrodynamics by the “complexity=volume” (CV) conjecture, and compare it with the holographic entanglement entropy. We consider three types of typical nonlinear electrodynamics and find that the holographic complexity can be utilized as a good probe of the superconductor phase transition in the nonlinear electrodynamics like the holographic entanglement entropy does. For the operator O−, the complexity decreases (or increases) monotonically as the absolute value of the nonlinear parameter |b| grows in the superconducting (or normal) phase, which is the opposite of the behavior of the holographic entanglement entropy, and this property holds for various types of the nonlinear electrodynamics. For the operator O+, in the superconducting phase, it is interesting to note that the complexity is a monotonic decreasing function of |b| for the Logarithmic nonlinear electrodynamics (LNE), but in systems with the Born-Infeld nonlinear electrodynamics (BINE) and Exponential nonlinear electrodynamics (ENE), as the parameter |b| increases, the complexity first decreases and arrives at its minimum at some threshold, then increases monotonously. Whereas the non-monotonic variation of the holographic entanglement entropy can be seen in all the three types of the nonlinear electrodynamics, concretely, it first rises, then descends with larger |b|, and has a peak at the inflection point. Furthermore, comparing with the BINE and LNE, we find that the ENE has stronger effect on the condensation formation, the subregion complexity and the entanglement entropy of the holographic superconductors with backreaction.

Adsorption of a thione bioactive derivative over different silver/gold clusters – DFT investigations

The interaction of Ag/Au clusters with 3,7-dihydropurine-2-thione (DPT) is studied by quantum chemical computations to find best geometries of the investigated model and descriptors. The adsorption energies are −34.69 to −13.33 kcal/mol for silver clusters, −32.34 to −17.24 for gold clusters and there are enhancements for the vibrational modes of DPT due to the adsorption process. In all complexes, the metal clusters are interacting with DPT mainly through N and S atoms. As a result the adsorption of DPT to the cages was the exothermic processes and the variations in entropy during the process were reduced for all clusters, indicating a transition to a more ordered structure. By applying different attempt frequencies, the recovery time for the drug from metal clusters are calculated and most of the metal clusters have a short recovery time indicating that these clusters are good sensors for the detection of the drug.

Information Entropy Analysis of Frictional Vibration under Different Wear States

To reveal the chaotic characteristics of friction vibration, pin–plate wear experiments were carried on a wear tester. Different wear states were designed by changing the amount of lubricating oil and distinguished with the friction coefficient. In order to improve the reliability of the collected data, the fictional vibration signals were denoised using an ensemble empirical mode decomposition (EEMD) method. The method of information entropy was proposed to measure the disorder of frequency energy distribution of friction vibration signals. The information entropy of friction vibration decreases in the running-in wear state, fluctuates steadily in the stable wear state, and increases rapidly in the severe wear state. The variation of information entropy of friction vibration signals is closely related to the surface topography of friction pairs. The results indicate that the information entropy of friction vibration can be applied to monitor and recognize the wear state of friction pairs.

A Significant Solar Energy Note on Powell-Eyring Nanofluid with Thermal Jump Conditions: Implementing Cattaneo-Christov Heat Flux Model

PTSCs (parabolic trough solar collectors) are widely employed in solar-thermal applications to attain high temperatures. The purpose of this study is to determine how much entropy is created when Powell-Eyring nanofluid (P-ENF) flows across porous media on a horizontal plane under thermal jump circumstances. The flow in PTSC was generated by nonlinear surface stretching, thermal radiation, and Cattaneo-Christov heat flux, which was utilized to compute heat flux in the thermal boundary layer. Using a similarity transformation approach, partial differential equations were converted into ordinary differential equations with boundary constraints. Then, the boundary restrictions and partial differential equations were merged to form a single set of nonlinear ordinary differential equations. To obtain approximate solutions to ordinary differential equations, the Keller-Box approach is utilized. Nanofluids derived from silver- and copper-based engine oil (EO) has been employed as working fluids. The researchers observed that changing the permeability parameter reduced the Nusselt number while increasing the skin frictional coefficient. Total entropy variation was also calculated using the Brinkman number for flow rates with Reynolds number and viscosity changes. The key result is that thermal efficiency is inversely proportional to particular entropy production. For example, using Cu-EO nanofluid instead of Ag-EO nanofluid increased the heat transport rate efficiency to 15–36%.

CT texture analysis as a predictor of favorable response to anti-PD1 monoclonal antibodies in metastatic skin melanoma

PurposeThe purpose of this study was to determine whether texture analysis features on pretreatment contrast-enhanced computed tomography (CT) images and their evolution can predict treatment response of metastatic skin melanoma (SM) treated with anti-PD1 monoclonal antibodies. Materials and methodsSixty patients (29 men, 31 women; median age, 56 years; age range: 27–91 years) with metastatic SM treated with pembrolizumab (43/60; 72%) or nivolumab (17/60; 28%) were included. Texture analysis of SM metastases was performed on baseline and first post-treatment evaluation CT examinations. Mean gray-level, entropy, kurtosis, skewness, and standard deviation values were derived from the pixel distribution histogram before and after spatial filtration at different anatomic scales, ranging from fine to coarse. Lasso penalized Cox regression analyses were performed to identify independent variables associated with favorable response to treatment. ResultsA total of 127 metastases were analyzed, with a median of two metastases per patient. Skewness at fine texture scale (spatial scale filtration [SSF] = 2; Hazard ratio [HR]: 3.51; 95% CI: 2.08–8.57; P = 0.010), skewness at medium texture scale (SSF = 3; HR: 0.56; 95% CI: 0.11–1.59; P = 0.014), variation of entropy at fine texture scale (SSF = 2; HR: 37.76; 95% CI: 3.48–496.22; P = 0.008) and LDH above the threshold of 248 UI/L (HR: 3.56; 95% CI: 1.78–21.35; P = 0.032] were independent predictors of response to treatment. ConclusionPretreatment CT texture analysis-derived tumor skewness and variation of entropy between baseline and first control CT examination may be used as predictors of favorable response to anti-PD1 monoclonal antibodies in patients with metastatic SM.

Exploring CT Texture Parameters as Predictive and Response Imaging Biomarkers of Survival in Patients With Metastatic Melanoma Treated With PD-1 Inhibitor Nivolumab: A Pilot Study Using a Delta-Radiomics Approach.

In the era of artificial intelligence and precision medicine, the use of quantitative imaging methodological approaches could improve the cancer patient’s therapeutic approaches. Specifically, our pilot study aims to explore whether CT texture features on both baseline and first post-treatment contrast-enhanced CT may act as a predictor of overall survival (OS) and progression-free survival (PFS) in metastatic melanoma (MM) patients treated with the PD-1 inhibitor Nivolumab. Ninety-four lesions from 32 patients treated with Nivolumab were analyzed. Manual segmentation was performed using a free-hand polygon approach by drawing a region of interest (ROI) around each target lesion (up to five lesions were selected per patient according to RECIST 1.1). Filtration-histogram-based texture analysis was employed using a commercially available research software called TexRAD (Feedback Medical Ltd, London, UK; https://fbkmed.com/texrad-landing-2/) Percentage changes in texture features were calculated to perform delta-radiomics analysis. Texture feature kurtosis at fine and medium filter scale predicted OS and PFS. A higher kurtosis is correlated with good prognosis; kurtosis values greater than 1.11 for SSF = 2 and 1.20 for SSF = 3 were indicators of higher OS (fine texture: 192 HR = 0.56, 95% CI = 0.32–0.96, p = 0.03; medium texture: HR = 0.54, 95% CI = 0.29–0.99, p = 0.04) and PFS (fine texture: HR = 0.53, 95% CI = 0.29–0.95, p = 0.03; medium texture: HR = 0.49, 209 95% CI = 0.25–0.96, p = 0.03). In delta-radiomics analysis, the entropy percentage variation correlated with OS and PFS. Increasing entropy indicates a worse outcome. An entropy variation greater than 5% was an indicator of bad prognosis. CT delta-texture analysis quantified as entropy predicted OS and PFS. Baseline CT texture quantified as kurtosis also predicted survival baseline. Further studies with larger cohorts are mandatory to confirm these promising exploratory results.

Applications of thermodynamics to study the physical phenomenon of heat conduction

Thermodynamics can be understood as the discipline of the physical sciences, that studies theoretically and practically the different manifestations of energy. The study of thermodynamics is important in relation to the understanding of thermal systems in industry, as well as, supporting energetic processes in living organisms. In relation to the study of energy processes in the context of heat transfer, concepts from thermodynamics are relevant. In the present investigation, the process of heat conduction in a metal bar is analyzed by applying the heat equation and the concept of entropy variation. The first part of the research proposes a numerical method to solve the heat equation in addition to a set of finite difference equations describing the energetic behavior of the system. The numerical solution of the heat equation and the thermodynamic behavior of the system are studied by programming to demonstrate the fit of the results with the theoretical models. Finally, applications of the achieved results in engineering contexts are discussed.

Magnetic transitions with magnetocaloric effects near room temperature related to structural transitions in Y0.9Pr0.1Fe2D3.5 deuteride

The structural and magnetic properties of Y0.9Pr0.1Fe2D3.5 deuteride have been investigated by synchrotron and neutron diffraction, magnetic measurements, and differential scanning calorimetry. Deuterium insertion induces a 23.5% cell volume increase and a lowering of crystal symmetry compared to the cubic C15 Y0.9Pr0.1Fe2 parent compound (Fd-3m SG). The deuteride is monoclinic (P21/c SG) below 330 K and undergoes a first-order transition between 330 and 350 K toward a pseudo-cubic structure (R-3 m SG) with TO–D = 342(2) K. In both structures, the D atoms are located in 96% R2Fe2 and 4% RFe3 tetrahedral interstitial sites (R = Y0.9Pr0.1). The compound is ferromagnetic, accompanied by a magnetostrictive effect below TC = 274 K. The analysis of the critical exponents indicates a second-order type transition with a deviation from the isotropic 3D Heisenberg model toward the 3D XY model. This implies an easy plane of magnetization in agreement with cell parameter variation showing planar magnetic orientation. A weak magnetic peak is even observed at the order–disorder transition with a maximum at 343 K. Magnetic entropy variations are characteristic of direct and inverse magnetocaloric effects at TC and TO–D, respectively.

MRI Findings of Acute Sports Injury of the Gastrocnemius Muscle

Objective.To investigate the MRI findings of acute sports injury of the gastrocnemius muscle and to provide evidence for clinical diagnosis. Methods. The MRI imaging data of 16 cases of gastrocnemius muscle group sports injury were compared, analyzed, and collated. In this paper, the variation of MRI image entropy before and after gastrocnemius muscle injury was studied by using the texture characteristics of the muscle image. Results. The experiment demonstrated that the entropy of MRI images before and after fatigue showed a decrease after muscle tissue was raised; that is, after muscle tissue underwent centrifugal and centripetal contraction. This result is more effective and convenient for nondestructive prediction of the gastrocnemius muscle injury state. Conclusion. MRI can show the site and pathological changes of acute gastrocnemius injury.

A statistical approach to secure health care services from DDoS attacks during COVID-19 pandemic.

Over the course of this year, more than a billion people have been afflicted by the COVID-19 outbreak. As long as individuals maintain their social distance, they should all be secure at this period. Because of this, there has been a rise in the usage of different online technologies, but at the same time, there has also been a rise in the likelihood of different cyber-attacks. A DDoS assault, the most prevalent and deadly of them all, impairs an online resource for its users. Thus, in this paper, we have proposed a filtering approach that can work efficiently in the COVID-19 scenario and detect the DDoS attack. We base our proposed approach on statistical methods like packet score and entropy variation for the identification of DDoS attack traffic. We have implemented our proposed approach on Omnet++ and for testing its efficiency we have checked it with different test cases. Our proposed approach detects the DDoS attack traffic with 96% accuracy and can also clearly have differentiated the DDoS attack traffic from the flash crowd.

Label Importance Ranking with Entropy Variation Complex Networks for Structured Video Captioning

Label Importance Ranking with Entropy Variation Complex Networks for Structured Video Captioning

Schottky-like anomaly in the heat capacity and magnetocaloric effect of charge-ordered single-crystalline (Sm, Ca, Sr)MnO[formula omitted] compound

We present a comprehensive experimental study on the magnetic and magnetocaloric properties of a charge-ordered single-crystalline Sm0.5Ca0.25Sr0.25MnO3 compound. The studies on x-ray photoelectron spectroscopy (XPS) reveals the presence of an equal distribution of Mn3+ and Mn4+ ions in the studied system. The Oxygen, O1s-core level spectra have been simulated with three binding energies curves, which correspond to the O2− ions, O1− ions, and chemically adsorbed oxygens, Ochem. The XPS analysis of the O1s-core-level spectra and magnetic characterizations indicate the proper stoichiometry of the present sample. Considering the change of volume phase fraction in the isofield magnetization measurements during the first-order magnetic phase transition from paramagnetic state to ferromagnetic state, the isothermal magnetic entropy change (ΔS) has been estimated based on the modified Clausius–Clapeyron equation. An inverse magnetocaloric effect has also been noticed in the -ΔS vs. T plot calculated by Maxwell’s thermodynamic relation, suggesting the dominant antiferromagnetic ground state supported by a charge-ordered phase of the studied system. The high-temperature zero-field heat capacity (CP) data can be well-interpreted quantitatively using the Debye model of heat capacity. With the extracted magnetic heat capacity (Cmag) data, the temperature variation of the magnetic entropy (S(0)), as well as the adiabatic temperature change (ΔTad), have been estimated. In addition to that, the low-temperature CP data displays a Schottky-like anomaly in the temperature region between 2 K and 20 K. The experimental data points are successfully fitted by considering the various contributing factors of the low-temperature heat capacity such as the lattice-phonon vibration (Clat), antiferromagnetic spin-wave (Cmag), and the two-level Schottky function (Csch) due to the energy splitting of the Sm3+ cations.

Thermodynamics and weak cosmic censorship conjecture of the high dimensional hairy AdS spacetime

In order to further verify the weak cosmic censorship conjecture in high-dimensional hairy space-time, we discuss the thermodynamics and the weak cosmic censorship conjecture from a five-dimensional hairy AdS black hole. With the absorption fermions by hairy AdS black holes, the energy-momentum relationship at the horizon is obtained via Dirac equations. Based on this energy-momentum relationship, we derive entropy variation and the change of the function that determines the minimum value of the event horizon. It turns out the first and second laws of black hole thermodynamics and the weak cosmic censorship conjecture are valid in high-dimensional hairy space-time.

Consistency between dynamical and thermodynamical stabilities for charged self-gravitating perfect fluid

The entropy principle shows that, for self-gravitating perfect fluid, the Einstein field equations can be derived from the extrema of the total entropy, and the thermodynamical stability criterion are equivalent to the dynamical stability criterion. In this paper, we recast the dynamical criterion for the charged self-gravitating perfect fluid in Einstein-Maxwell theory, and further give the criterion of the star with barotropic condition. In order to obtain the thermodynamical stability criterion, first we get the general formula of the second variation of the total entropy for charged perfect fluid case, and then obtain the thermodynamical criterion for radial perturbation. We show that these two stability criterion are the same, which suggest that the inherent connection between gravity and thermodynamic even when the electric field is taken into account.

Hub clearance effect in the design space of the cantilevered stator embedded in a 4-stage low-speed research compressor

This paper focuses on the effect of hub clearance in the design space of the highly loaded cantilevered stator. The embedded 1.5 stages of a low-speed research compressor (LSRC) were conducted with Unsteady Reynolds Average Navier-Stokes (URANS) numerical investigation, and the cantilevered stator adopts positive bowed and fore-sweep three-dimensional design. The research details that with the hub clearance increasing from 1.1% to 4.5% span, the loss coefficient and the total leakage momentum of the cantilevered stator correspond to the change of the blade loading near the hub. When designing the inlet metal angle of the rotor downstream the cantilevered stator, emphasis should be given to considering the inter-stage matching below 15% span. The mixing of leakage flow in 1.1% span clearance and 2.5% span clearance is basically completed in the S3 passage, but the mixing of leakage flow in 3.5% span clearance and 4.5% span clearance is still relatively strong downstream of S3. When calculating the relative entropy variation based on Denton’s mixing model, attention should be paid to the relationship between the leakage flow velocity affected by the hub gap and the mainstream velocity, as well as whether the mixing has been completed in the blade passage.