Noncritical Region Research Articles

Optimization of crossover SRK equation of state for thermodynamic properties calculation of CO2

In recent years, the CO2 super/transcritical power cycle has gained significant attention as the most widely studied power cycle. The accurate thermodynamic properties data is very important for cycle design and performance analysis. In this study, the Kiselev's crossover method based on the renormalization group theory is used to improve the classic SRK equation of state in non-critical region and reproduce the critical fluctuation phenomenon in critical region. The nonlinear equations method and interior-point method are used in the parameter fitting of crossover SRK (CSRK) to get the optimal parameters. The replaced method avoids the problem that Newton iteration method is prone to divergence and falling into local optima. The thermodynamic properties of CO2 including the VLE properties, heat capacity and speed of sound are calculated by CSRK, respectively. The results show the calculation of the non-critical region is improved, and the critical fluctuation phenomenon in the near-critical region is described accurately, especially the second-order thermodynamic properties calculation results is improved from 3.65 % to 2.80 % compared with our previous work.

Efficient Region of Interest Encryption Based on a New Chaotic Map

The recent advances in digital imaging and transmission over network demand a secure and efficient image encryption system. Traditional cryptographic algorithms encrypt full image, however only some part of the image is important and needs complex encryption algorithm to provide security. To address this issue, we have proposed a novel encryption technique based on YOLOv2 object detection and proposed Gauss-Square Cosine (GSC) chaotic map. YOLOv2 is used to divide the image into region of interest (ROI) and noncritical region. SHA2-256 hash of scrambled noncritical region is then used as an initial value of GSC chaotic map to encrypt ROI. ROI encryption technique uses pixel permutation to decorrelate adjacent pixels and random substitution to change pixel values. Differential and statistical analysis demonstrate the complexity of proposed chaotic map and robustness of proposed technique against various security attacks. Thus the proposed encryption technique is secure and efficient for large-sized images.

Thermodynamic geometry of spin-one lattice models. I. Spin and quadrupolar orders and critical scaling functions in one dimension.

State space Riemannian geometry is obtained for the one-dimensional Blume-Emery-Griffiths model and its Blume-Capel and Griffiths model limits, and its (pseudo)critical as well as noncritical parameter regimes are extensively investigated. Two codimension one geometries are obtained by taking suitable hypersurfaces in the three-dimensional state space manifold, and the induced thermal metrics are accordingly interpreted in terms of constrained fluctuations. The three-dimensional scalar curvature and the two two-dimensional curvatures are shown to be consistent with Ruppeiner's conjecture relating the inverse of the singular free energy to the thermodynamic scalar curvature. Moreover, they are found to be in an excellent agreement over a greater part of the noncritical region with the corresponding correlation lengths for the spin and the quadrupolar order parameters. The scaling function for the free energy near the pseudocritical and tricritical points is obtained thermodynamically by using Ruppeiner's conjecture. A connection is made between the sign change in the curvatures and the change in fluctuation patterns of the order parameters. In the accompanying paper we shall analyze the geometry of the spin-one model in its mean field approximation.

Hyper-order baryon number fluctuations at finite temperature and density

The authors study the fluctuations of baryon number at finite temperature and density near the QCD phase transition from quark-gluon plasma to hadronic matter. Performing the calculations up to tenth order, they find a non-monotonic dependence of baryon number fluctuations on collision energy, which can arise in the non-critical crossover region of the phase diagram. The results compare well with recent experimental measurements from the STAR collaboration.

Narrowing of the neonatal region in the FBN1 gene

Abstract Background Neonatal Marfan syndrome (MFS) is considered the most severe form of MFS and is characterized by early childhood death due to congestive heart failure. It has been suggested that genetic variants associated with this clinical presentation, cluster in a specific region between exons 24 and 32. It has been reported that patients carrying genetic variants in these exons have worse prognosis. Purpose Our purpose was to analyze cardiovascular outcome by location of the genetic variants in the “neonatal region” of the FBN1 gene. Materials and methods We analyzed clinical data on 1353 carriers and affected relatives with 683 missense pathogenic or likely pathogenic genetic variants of FBN1 gene (including cases identified in our laboratory and cases described in the literature) in whom age at last follow-up was available. Kaplan-Meier survival curves were generated to examine location of the genetic variant in the FBN1 gene in relation to survival free of surgical intervention or cardiovascular (CV) death (composite of deaths related to aortic dissection, heart failure/transplant, sudden, stroke or CV surgery). Missense genetic variants were classified as located in the “neonatal region” (residues 952–1363, corresponding to exons 24–32) and in the “non-neonatal region” (residues 45–951 and 1364–2731). In the “neonatal region”, we have also analyzed a sub-region of “over-representation” of heart failure deaths in the first year of life, which we called “critical neonatal region” (amino acids 1028–1088, corresponding to exon 25 and few residues from exon 26) in comparison to the “non-critical neonatal region”. Results Data were examined on 1060 patients with missense variants located in the “non neonatal region” and on 293 patients with missense variants located in the “neonatal region”. Of these, 96 patients were carriers of missense variants in the “critical neonatal region”, the rest of patients carried variants in the neonatal region, outside this particular domain (“non-critical neonatal region”). Patients carrying missense variants in the neonatal region had worse prognosis than those carrying variants outside this region. This poorer outcome was due to events occurring in patients carrying variants in the “critical neonatal region” (see Figure). These patients had the worse prognosis (p=0.000108, vs. the other groups). Furthermore, events in the non-critical neonatal region were similar to other missense variants located outside the neonatal region. There were no differences in the “neonatal region” when analyzing by gender. Conclusion In our cohort, the worse prognosis seen in patients carrying missense pathogenic or likely pathogenic variants in the “neonatal region” compared to the “non-neonatal region”, was due to events in patients carrying missense variants in a small subregion which we called the “critical-neonatal region” (exons 25 and 26). These patients had the worse prognosis, irrespective of gender. Funding Acknowledgement Type of funding sources: Private company. Main funding source(s): Health in Code Figure 1. Neonatal region FBN1

Phantom Bethe excitations and spin helix eigenstates in integrable periodic and open spin chains

We demonstrate the existence of special phantom excitations for open and periodically closed integrable systems at the example of the $XXZ$ Heisenberg spin chain. The phantom excitations do not contribute to the energy of the Bethe state and correspond to special solutions to the Bethe Ansatz equations with infinite "phantom" Bethe roots. The phantom Bethe roots lead to degeneracies between different magnetization sectors in the periodic case and to the appearance of spin helix states (SHS), i.e. periodically modulated states of chiral nature in both open and closed systems. For the periodic chain, phantom Bethe root (PBR) solutions appear for anisotropies $\De=\cosh\eta$ with $\exp(\eta)$ being a root of unity, thus restricting the phenomenon to the critical region $|\De|<1$. For the open chain, PBR solutions appear for any value of anisotropy, both in the critical and in the non-critical region, provided that the boundary fields satisfy a criterion which we derive in this paper. There exist PBR solutions with all Bethe roots being phantom, and PBR solutions that consist of phantom roots as well as regular (finite) roots. Implications of our results for an experiment are discussed.

Effect of building cross-section shape on air pollutant dispersion around buildings

This research investigates the effect of building cross-section shape on the air pollutant dispersion around an isolated building. A Computational Fluid Dynamic (CFD) model was developed and validated based on detailed wind tunnel experimental data. Both Large Eddy Simulation (LES) and Realizable k-ε models were used for turbulence closure and LES was found to provide a better agreement with experimental results than the RANS model, particularly in replicating pollutant dispersion characteristics associated with wind-structure interaction. The LES model was then utilized to study the effect of building cross-section shape. Four building cross-section shapes, square, chamfered, curved and circular, along with different air pollutant emission locations were studied. It has been found that the area around an isolated building can be categorized into three emission regions, namely the windward critical emission region, the leeward critical emission region and the side non-critical emission region. The air pollutant emissions from the leeward critical emission region affect the building the most. Furthermore, the size of this region depends on the building cross-section shape, with the circular and curved buildings having a smaller leeward critical emission region than those for the chamfered and square buildings. Evidently, air pollutant dispersion around a building is dominated by wind-structure interaction which in turn is dependent on the building cross-sectional shape. These characteristics can be utilized to mitigate air pollutant dispersion in urban environments in conjunction with careful consideration of the air pollutant emission location relative to a building.

Magnetization revivals and dynamics of quantum correlations in a Kitaev spin chain

We investigate the dynamics of a spin chain with Kitaev-type interaction in a transverse magnetic field, for both a constant field and a periodically kicked field. We investigate analytically the revivals in the dynamical behavior of the magnetization, and measures of local quantum correlations, the concurrence measure of the entanglement, and the quantum discord. The magnetization revivals are seen even for larger chain lengths, with reduced revival peaks, both near and away from the critical point at zero magnetic field. The quantum entanglement and correlation measures, contrary to the expected behavior, exhibit reduced quantum correlations in the critical region, compared to the region away from the critical point. The concurrence is larger than the quantum discord away from the critical region. The pair entanglement is near zero for all times in the critical region, though the quantum discord is nonzero, capturing the underlying diagonal correlations. The kicked magnetic field dynamics shows similar evolution for the magnetization and quantum correlations. For special values of the kicking period, the concurrence shows alternates between zero and nonzero values for successive kicks in the noncritical region.

A Simple Superposition Formulation to Predict the Underwater Electric Potential Signature of Naval Vessels

The underwater electric potential (UEP) signature is an electric signal, which can be exploited by naval mines to be utilized as a possible trigger indicator and may cause severe damage to the vessel and the onboard crew. Hence, knowing the UEP signature as exactly as possible can help to evaluate a possible risk of the vessel being detected by naval mines or if the UEP signature is within a noncritical region. As the UEP signature differs for changes of the corrosion protection system, the UEP signature is usually unknown for new conditions. In this work, we present a simple mathematical formulation to predict the UEP signature based on the mere use of a single reference UEP signature, and the corresponding currents, which are excited by the impressed current cathodic protection (ICCP) system. With this methodology, deviations below 10% between the maximum of the simulated UEP signature and the predicted UEP signature can be achieved, even in the presence of the nonlinear corrosion process. Furthermore, a corrosion protective coating of the propellers can significantly reduce the influence of the nonlinear corrosion process on the total UEP signature to improve the prediction accuracy of the superposition formulation as presented in this work.

Kinetics of two redox reactions in 2‐butoxyethanol and water near its critical point of solution

AbstractThe rate constants of two redox reactions and in the critical solution of 2‐butoxyethanol and water have been measured by using the UV spectrophotometry at the initial reaction stage. It was found that the rate constants at various temperatures for two reactions were well described by the Arrhenius equation in the noncritical region. The critical slowing down effect was detected in the critical region. The critical slowing down exponents were determined to be 0.044 ± 0.004 and 0.046 ± 0.005 for reactions and , respectively. The values of the critical slowing down exponents showed that only dynamic critical slowing down effect, and no thermodynamic singularity could be observed for the two reactions.

Numerical analysis on aerodynamic characteristics of short cylindrical terminal-sensitive bullet

The flow-induced lateral vibration phenomenon of the terminal sensitive bullets (TSB) when it is dispersed by the airborne distributor is taken as the research background. Based on the Fluent, the flow around a rotating short cylindrical TSB (L/D &lt; 1) is simulated and analyzed varying with relative rotation velocity at high Re number (1×105 ≤ Re ≤ 3×106). The simulation results show that the flow field structure of the short cylinder with two free ends is different from the symmetry of the short cylindrical flow field with one free end, and there is no horseshoe vortex. Compared to the long cylinder with double free ends, the Cd of the short cylinder is more sensitive to the change of Re. With the increase of Re, the Cd of the short cylinder decreases, and the value is between the infinite cylinder and the sphere in the non-critical region. When the short cylinder rotates at the angular velocity ω, the top vortex bends and deforms to a ‘C’ shape on the leeward side where the fluid is accelerated. Due to the periodic disturbance of the detector, the aerodynamic coefficient of the rotating TSB is periodically vibrated. In a single cycle, the waveform of the cd shows a ‘W’ shape, and the waveform of the cl is ‘M’.

Holographic butterfly effect and diffusion in quantum critical region

We investigate the butterfly effect and charge diffusion near the quantum phase transition in holographic approach. We argue that their criticality is controlled by the holographic scaling geometry with deformations induced by a relevant operator at finite temperature. Specifically, in the quantum critical region controlled by a single fixed point, the butterfly velocity decreases when deviating from the critical point. While, in the non-critical region, the behavior of the butterfly velocity depends on the specific phase at low temperature. Moreover, in the holographic Berezinskii-Kosterlitz-Thouless transition, the universal behavior of the butterfly velocity is absent. Finally, the tendency of our holographic results matches with the numerical results of Bose-Hubbard model. A comparison between our result and that in the O(N ) nonlinear sigma model is also given.

Experimental investigation of the dynamics of a brake shoe

The experimental stand is described and the results of investigation of the motion of a brake shoe are presented. In the noncritical region, the friction coefficient is determined experimentally. It is shown that its value corresponds to the condition of uniqueness of the solution for construction of this brake shoe. The dynamics observed in the paradoxical-motion region is described.

Kinetics of a hydrolysis reaction in critical surfynol465/n-butanol/ethyl acetate/water microemulsion

We have constructed the pseudoternary phase diagram of surfynol465/n-butanol/ethyl acetate/water with mass ratio of surfynol465 to n-butanol being 1.0. In the O/W microemulsion region, we have measured the rate of a first-order hydrolysis reaction of tert-butyl bromide near and far away from the critical point. In the noncritical region, the rate constants of the reaction obey respective Arrhenius equation. In the critical region, the rate constants did not deviate from Arrhenius equation, and no critical effect was apparent, which agreed with the Griffiths–Wheeler rule. This work extended the studies of critical effect on the chemical reaction to more complicated O/W microemulsion media and added to the current interest in microemulsion system functioning as media for chemical reactions.

Critical Anomalies of Two SN1 Hydrolysis Reactions in Critical Binary Solutions.

Rates of SN1 hydrolysis reactions for 2-chloro-2-methylbutane in the critical solution of isobutyric acid + water and for 2-bromo-2-methylpropane in the critical solution of triethylamine + water in the one-phase region and at various temperatures have been determined respectively by conductance measurements. It was found that the reaction rates at different temperatures for those two SN1 reactions were well described by the Arrhenius equation in the noncritical region, whereas near the critical points the critical slowing down was clearly detected. These results are inconsistent with a previous report in the literature (J. Phys. Chem. A 2003, 107, 8435 - 8443). Reanalyzing the literature data, we found that if an Arrhenius equation appropriate to either the one-phase region or the two-phase region being examined was used as the background, a critical slowing down rather than a speeding up was detected for the reaction in both the one-phase region and the two-phase region. The experimental data from different sources were fitted with a simplified crossover formalism characterizing the critical effect on the reactions to determine the critical slowing down exponents, which were found to be about 0.04, showing that only a dynamic critical slowing down could be detected for these reaction systems. This phenomenon was attributed to the fact that the SN1 hydrolysis reaction is neither a first-order nor a pseudo-first-order reaction in the reverse direction and the kinetic measurements were carried out in a region quite far from the equilibrium of the reactions.

Kinetics of the oxidation of iodide ion by persulfate ion in the critical water/bis(2-ethylhexyl) sodium sulfosuccinate/n-decane microemulsions.

In this work, we studied the kinetics of the oxidation of iodide ion by persulfate ion in the critical water/bis(2-ethylhexyl) sodium sulfosuccinate (AOT)/n-decane microemulsions with the molar ratios of water to AOT being 35.0 and 40.8 via the microcalorimetry at various temperatures. It was found that the Arrhenius equation was valid for correlating experimental measurements in the noncritical region, but the slowing down effect existed significantly in the near critical region. We determined the values of the critical slowing down exponent and found it to be 0.187 ± 0.023 and 0.193 ± 0.032, respectively, which agreed well with the theoretical value of 0.207 predicted by the Griffiths-Wheeler rule for the singularity of the dimer/monomer droplet equilibrium in the critical AOT/water/n-decane microemulsions.

Location of the Potts-critical end point in the frustrated Ising model on the square lattice

We report on Monte Carlo simulations for the two-dimensional frustrated $J_1$-$J_2$ Ising model on the square lattice. Recent analysis has shown that for the phase transition from the paramagnetic state to the antiferromagnetic collinear state different phase-transition scenarios apply depending on the value of the frustration $J_2 / J_1$. In particular a region with critical Ashkin-Teller-like behavior, i.e., a second-order phase transition with varying critical exponents, and a noncritical region with first-order indications were verified. However, the exact transition point $[J_2/J_1]_C$ between both scenarios was under debate. In this paper we present Monte Carlo data which strengthens the conclusion of Jin \et [Phys. Rev. Lett. \textbf{108}, 045702 (2012)] that the transition point is at a value of $J_2/J_1 \approx 0.67$ and that double-peak structures in the energy histograms for larger values of $J_2/J_1$ are unstable in a scaling analysis.

Caveolin-1 Mediates the Internalization of Functional Insulin Receptors in Beta-Cells

Type 2 diabetes is associated with defects in insulin receptor (InsR) signalling, including in beta-cells. Internalization of the activated InsR complex is necessary to initiate signalling. Mechanisms of InsR internalization in beta-cells remain unclear, although Caveolin-1 (CAV1) has been implicated in other cell types. We labelled InsR with monomeric fluorescent proteins in a non-critical linker region between the furin-like region and the transmembrane domain. Total internal reflection microscopy in living MIN6 beta-cells revealed that CAV1 is recruited to InsR membrane domains right before receptor internalization. These results were confirmed by super-resolution stimulated emission depletion microscopy, which showed a CAV1 protein coat around membrane nanodomains containing InsR. To investigate if CAV1 is essential for InsR internalization, we compared the distribution of InsR in cells expressing CAV1 mutant proteins. MIN6 cells over-expressing dominant negative CAV1-Y14F showed defects of InsR internalization, with virtually complete accumulation plasma membrane of InsR. Overexpression of CAV1 in MIN6 cells leads to an increased Erk1/2 phosphorylation upon insulin treatment compared to empty-vector controls. Erk1/2 signalling is further increased in cells overexpressing the dominant-positive CAV1-Y14D mutant. Interestingly, Akt phosphorylation was not affected by CAV1 overexpression. These data strongly suggest that CAV1-mediated internalization of the InsR is required for Erk1/2 signalling but Akt signalling is mostly induced by insulin receptors localized at the plasma membrane. Together, our data give new insights on the mechanisms in InsR signalling in the beta-cell.

Quantum discord in matrix product systems

We consider a class of quantum systems with spin-flip symmetry and derive the quantum correlation measured by the quantum discord (QD). As an illustration, we investigate the QD in a three-body interaction model and an XYZ interaction model, whose ground states can be expressed as matrix product states, and the QD is exactly soluble. We show that the QD behaves differently than the quantum entanglement (QE) in many ways; for example, they may show opposite monotonicity and completely different finite-size effects. Furthermore, we compare the capability of the QD and the QE to detect quantum phase transitions (QPTs) and find that the QD is more reliable than the QE for signaling QPTs in these models: In the three-body interaction model, the QE is singular at the quantum critical point, however, it exhibits an additional singularity in the noncritical region, while the analyticity of the QD can be used to identify the quantum critical point perfectly; and in the XYZ interaction model, the QE vanishes in the thermodynamic limit, thus losing its ability to detect QPTs, while the QD still functions very well.

Roles of Dopamine in Circadian Rhythmicity and Extreme Light Sensitivity of Circadian Entrainment

Light has profound behavioral effects on almost all animals, and nocturnal animals show sensitivity to extremely low light levels [1-4]. Crepuscular, i.e., dawn/dusk-active animals such as Drosophila melanogaster are thought to show far less sensitivity to light [5-8]. Here we report that Drosophila respond to extremely low levels of monochromatic blue light. Light levels three to four orders of magnitude lower than previously believed impact circadian entrainment and the light-induced stimulation of locomotion known as positive behavioral masking. We use GAL4;UAS-mediated rescue of tyrosine hydroxylase (DTH) mutant (ple) flies to study the roles of dopamine in these processes. We present evidence for two roles of dopamine in circadian behaviors. First, rescue with either a wild-type DTH or a DTH mutant lacking neural expression leads to weak circadian rhythmicity, indicating a role for strictly regulated DTH and dopamine in robust circadian rhythmicity. Second, the DTH rescue strain deficient in neural dopamine selectively shows a defect in circadian entrainment to low light, whereas another response to light, positive masking, has normal light sensitivity. These findings imply separable pathways from light input to the behavioral outputs of masking versus circadian entrainment, with only the latter dependent on dopamine.